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Sample records for heat shock-triggered released

  1. Recovery of heat shock-triggered released apoplastic Ca2+ accompanied by pectin methylesterase activity is required for thermotolerance in soybean seedlings

    PubMed Central

    Wu, Hui-Chen; Hsu, Shih-Feng; Luo, Dan-Li; Chen, Shiang-Jiuun; Huang, Wen-Dar; Lur, Huu-Sheng; Jinn, Tsung-Luo

    2010-01-01

    Synthesis of heat shock proteins (HSPs) in response to heat shock (HS) is essential for thermotolerance. The effect of a Ca2+ chelator, EGTA, was investigated before a lethal HS treatment in soybean (Glycine max) seedlings with acquired thermotolerance induced by preheating. Such seedlings became non-thermotolerant with EGTA treatment. The addition of Ca2+, Sr2+ or Ba2+ to the EGTA-treated samples rescued the seedlings from death by preventing the increased cellular leakage of electrolytes, amino acids, and sugars caused by EGTA. It was confirmed that EGTA did not affect HSP accumulation and physiological functions but interfered with the recovery of HS-released Ca2+ concentration which was required for thermotolerance. Pectin methylesterase (PME, EC 3.1.1.11), a cell wall remodelling enzyme, was activated in response to HS, and its elevated activity caused an increased level of demethylesterified pectin which was related to the recovery of the HS-released Ca2+ concentration. Thus, the recovery of HS-released Ca2+ in Ca2+-pectate reconstitution through PME activity is required for cell wall remodelling during HS in soybean which, in turn, retains plasma membrane integrity and co-ordinates with HSPs to confer thermotolerance. PMID:20444907

  2. 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.

  3. Helium release from radioisotope heat sources

    SciTech Connect

    Peterson, D.E.; Early, J.W.; Starzynski, J.S.; Land, C.C.

    1984-05-01

    Diffusion of helium in /sup 238/PuO/sub 2/ fuel was characterized as a function of the heating rate and the fuel microstructure. The samples were thermally ramped in an induction furnace and the helium release rates measured with an automated mass spectrometer. The diffusion constants and activation energies were obtained from the data using a simple diffusion model. The release rates of helium were correlated with the fuel microstructure by metallographic examination of fuel samples. The release mechanism consists of four regimes, which are dependent upon the temperature. Initially, the release is controlled by movement of point defects combined with trapping along grain boundaries. This regime is followed by a process dominated by formation and growth of helium bubbles along grain boundaries. The third regime involves volume diffusion controlled by movement of oxygen vacancies. Finally, the release at the highest temperatures follows the diffusion rate of intragranular bubbles. The tendency for helium to be trapped within the grain boundaries diminishes with small grain sizes, slow thermal pulses, and older fuel.

  4. Heat release rate of wood-plastic composites

    Treesearch

    N. M. Stark; R. H. White; C. M. Clemons

    1997-01-01

    Wood-plastic composites are becoming more important as a material that fulfills recycling needs. In this study, fire performance tests were conducted on several compositions of wood and plastic materials using the Ohio State University rate of heat release apparatus. Test results included five-minute average heat release rate in kW/m2 (HRR avg) and maximum heat release...

  5. Heat release from wood wall assemblies using oxygen consumption method

    Treesearch

    Hao C. Tran; Robert E. White

    1990-01-01

    The concept of heat release rate is gaining acceptance in the evaluation of fire performance of materials and assemblies. However, this concept has not been incorporated into fire endurance testing such as the ASTM E-119 test method. Heat release rate of assemblies can be useful in determining the time at which the assemblies start to contribute to the controlled fire...

  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. Dynamical response of nanostructures and Joule heat release.

    PubMed

    Gurevich, V L; Kozub, V I; Muradov, M I

    2011-10-12

    We consider Joule heat release in a quantum wire joining two classical reservoirs under the action of a nonstationary periodic electric field. The rate of heat generation and its spatial distribution is discussed. The heat is spread over the lengths of electron mean free paths in the reservoirs. We find that the total rates of heat generation in both reservoirs that are joined by the nanostructure are the same.

  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. Release of fission gas during transient heating of LWR fuel

    SciTech Connect

    Gehl, S.M.

    1982-05-01

    The direct electrical heating technique was used to study fission-gas release and mechanical behavior of irradiated light-water reactor (LWR) fuels during thermal transients. An empirical correlation between fission-gas release and transient temperature history was developed for power-cooling mismatch (PCM) and anticipated transients. Gas release during the refill portion of a design-basis loss of cooling accident was estimated to be less than 1%. Fission-gas release during PCM accidents was found to be controlled by intergranular microcracking and the interlinkage of tunnels on grain edges. For high-gas-release transients, the fractional gas release was shown to be equal to the fractional coverage of grain boundaries by microcracks. Temperature calculations indicated that microcracking causes a significant decrease in the fuel thermal conductivity.

  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. Nanovalve-Controlled Cargo Release Activated by Plasmonic Heating

    PubMed Central

    Croissant, Jonas; Zink, Jeffrey I.

    2012-01-01

    The synthesis and operation of a light-operated nanovalve that controls the pore openings of mesoporous silica nanoparticles containing gold cores nanoparticles is described. The nanoparticles, consisting of 20 nm gold cores inside ~150 nm mesoporous silica spheres, were synthesized using a unique one-pot method. The nanovalves are comprised of cucurbit[6]uril rings encircling stalks that are attached to the ~2 nm pore openings. Plasmonic heating of the gold core raises the local temperature and decreases the ring-stalk binding constant, thereby unblocking the pore and releasing the cargo molecules that were preloaded inside. Bulk heating of the suspended particles to 60 °C is required to release the cargo, but no bulk temperature change was observed in the plasmonic heating release experiment. High intensity irradiation caused thermal damage to the silica particles, but low intensity illumination caused a sufficient local temperature increase to operate the valves without damaging the nanoparticles containers. These light-stimulated, thermally activated mechanized nanoparticles demonstrate a new system with potential utility for on-command drug release. PMID:22540671

  12. 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

  13. Prediction of heat release effects on a mixing layer

    NASA Technical Reports Server (NTRS)

    Farshchi, M.

    1986-01-01

    A fully second-order closure model for turbulent reacting flows is suggested based on Favre statistics. For diffusion flames the local thermodynamic state is related to single conserved scalar. The properties of pressure fluctuations are analyzed for turbulent flows with fluctuating density. Closure models for pressure correlations are discussed and modeled transport equations for Reynolds stresses, turbulent kinetic energy dissipation, density-velocity correlations, scalar moments and dissipation are presented and solved, together with the mean equations for momentum and mixture fraction. Solutions of these equations are compared with the experimental data for high heat release free mixing layers of fluorine and hydrogen in a nitrogen diluent.

  14. Gas motion through porous objects with nonuniform local distribution of heat-release sources

    NASA Astrophysics Data System (ADS)

    Levin, V. A.; Lutsenko, N. A.

    2008-09-01

    The gas motion through porous objects in the gravity force field with a non-uniform distribution of heat sources, which may arise as a result of natural or man-caused catastrophes (as the damaged power unit of the Chernobyl NPP), is investigated. The influence of different parameters of the heat-releasing zone on the process of cooling of such objects is analyzed with the aid of computational experiment. It is shown that the porous element heating is affected not only by the height of the heat-releasing zone and the heat-release intensity therein but also by the distance of the heat-releasing zone from the element inlet as well as by the width of the heat-releasing zone. The phenomenon of a reduction of the porous element heating with increasing distance of the heat-releasing zone from the porous element inlet is revealed. An ambiguous dependence of the porous object heating on the width of the heat-release zone is identified: at a growth of the heat-releasing zone width, the heating of the element may both increase and decrease depending on the distance of the heat-release zone from the element inlet.

  15. Optical investigation of heat release and NOx production in combustion

    NASA Astrophysics Data System (ADS)

    Timmerman, B. H.; Patel, S.; Dunkley, P.; Bryanston-Cross, P. J.

    2005-08-01

    Two passive optical techniques are described to investigate combustion. Optical Emission Tomography (OET) is used for non-intrusive study of heat release through the detection of chemiluminescence by the hydroxyl radical that is generated in the burning process. The OET technique described here is based on a passive fibre-optic detection system, which allows spatially resolved high-frequency detection of the flame front in a combustion flame, where all fibres detect the emission signals simultaneously. The system withstands the high pressures and temperatures typically encountered in the harsh environments of gas turbine combustors and IC engines. The sensor-array is non-intrusive, low-cost, compact, simple to configure and can be quickly set up around a combustion field. The maximum acquisition rate is 2 kHz. This allows spatially resolved study of the fast phenomena in combustion. Furthermore, the production of NOx is investigated through the emission of green light as a result of adding tri-methyl-borate to a flame. In combustion, the tri-methyl-borate produces green luminescence in locations where NOx would be produced. Combining the green luminescence visualisation with OET detection of the hydroxyl radical allows monitoring of heat release and of NOx production areas, thus giving a means of studying both the burning process and the resulting NOx pollution.

  16. Heat Release Effects on Scaling Laws for Turbulent Shear Flows

    NASA Astrophysics Data System (ADS)

    Tacina, Kathleen M.; Dahm, Werner J. A.

    1996-11-01

    Experiments have long suggested apparent differences in the fundamental scaling laws for turbulent shear flows between reacting and nonreacting flows. These differences result from the density changes produced by exothermic reaction, and are here shown to be similar to the changes produced by free-stream density differences in nonreacting flows. Motivated by this, we show that the fundamental scaling laws can be generalized to predict the changes due to heat release. The bilinear dependence of temperature T(ζ) on an appropriately defined conserved scalar ζ allows the density changes to be related to an equivalent nonreacting flow, in which one of the free-stream fluid temperatures is set to a value determined by the adiabatic flame temperature and the overall stoichiometry. This scaling principle is applied to turbulent jet diffusion flames, and leads to a generalized scaling variable d^+ for both reacting and nonreacting flows; it effectively extends the momentum diameter d^* of Thring & Newby (1952) and Ricou & Spalding (1961) to reacting flows. The resulting predicted effects of heat release show good agreement with all available data from momentum-dominated jet flames. (Supported by GRI Contract No. 5093-260-2728.)

  17. 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.

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

    NASA Technical Reports Server (NTRS)

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

    1976-01-01

    Data from the Nimbus 5 electrically scanning microwave radiometer (ESMR) are used to make calculations of the latent heat release (L.H.R.) and the distribution of rainfall rate in a tropical cyclone as it grows from a tropical disturbance to a typhoon. The L.H.R. (calculated over a circular area of 4 deg latitude radius) increases during the development and intensification of the storm from a magnitude of 2.7 X 10 to the 21st power ergs/s (in the disturbance stage) to 8.8 X 10 to the 21st power ergs (typhoon stage). The latter value corresponds to a mean rainfall rate of 2.0 mm hr/s. The more intense the cyclone and the greater the L.H.R., the greater the percentage contribution of the larger rainfall rates to the L.H.R. In the disturbance stage the percentage contribution of rainfall rates less than or minus 6 mm hr/s is typically 8%; for the typhoon stage, the value is 38%. The distribution of rainfall rate as a function of radial distance from the center indicates that as the cyclone intensifies, the higher rainfall rates tend to concentrate toward the center of the circulation.

  19. Burning rate of solid wood measured in a heat release rate calorimeter

    Treesearch

    H. C. Tran; R. H. White

    1992-01-01

    Burning rate is a key factor in modeling fire growth and fire endurance of wood structures. This study investigated the burning rate of selected wood materials as determined by heat release, mass loss and charring rates. Thick samples of redwood, southern pine, red oak and basswood were tested in a heat release rate calorimeter. Results on ignitability and average beat...

  20. Effects of anthropogenic heat release upon the urban climate in a Japanese megacity.

    PubMed

    Narumi, Daisuke; Kondo, Akira; Shimoda, Yoshiyuki

    2009-05-01

    This report presents results of investigations of the influence of anthropogenic heat release in Japanese megacity (Keihanshin district) upon the urban climate, using the energy database [Shimoda et al., 1999. Estimation and evaluation of artificial waste heat in urban area. Selected Papers from the Conference ICB-ICUC'99 WCASP-50 WMO/TD no. 1026] as a part of the land-surface boundary conditions of a mesoscale meteorological simulation model. The calculated results related to atmospheric temperature distribution were similar to observed values not only for daily averages but also for amplitudes and phases of diurnal change. To reproduce accurately, it is essential to reproduce urban characteristics such as an urban canopy and anthropogenic heat release in a fine resolution mesh. We attempted an analysis using current data for anthropogenic heat and under uniform heat release conditions, to investigate temporal and spatial characteristics in relation to the influence of anthropogenic heat release on the urban climate. The results of investigation into the influence of anthropogenic heat release on atmospheric temperature using current data indicate that the amount of heat released is lower at night than during the day, but the temperature rise is nearly 3 times greater. Results of investigation into the influence of anthropogenic heat release on wind systems using current data indicate that the onset of land breezes is delayed, particularly in a coastal area. Investigation into the temporal characteristics related to the influence of anthropogenic heat release under uniform heat release conditions showed a maximum influence on temperature during the predawn period.

  1. Ventilation during cardiopulmonary bypass: impact on heat shock protein release.

    PubMed

    Beer, L; Szerafin, T; Mitterbauer, A; Kasiri, M M; Debreceni T Palotás, L; Dworschak, M; Roth, G A; Ankersmit, H J

    2014-12-01

    Cardiopulmonary bypass (CPB), utilized in on-pump coronary artery bypass graft procedures (CABG) induces generalized immune suppression, release of heat shock proteins (HSP), inflammatory markers and apoptosis-specific proteins. We hypothesized that continued mechanical ventilation during cardiopulmonary bypass attenuates immune response and HSP liberation. Thirty patients undergoing conventional coronary artery bypass graft (CABG) operation were randomized into a ventilated on CPB (VG; N.=15) and a non-ventilated CPB group (NVG; N.=15). Blood samples were drawn at the beginning and end of surgery, as well as on the five consecutive postoperative days (POD). Molecular markers were measured by ELISA. Data are given as mean ± (SD). Mann-Whitney-U-test was used for statistical analysis. Serum concentrations of HSP70 were significantly lower in VG compared to NVG on POD-1 (VG: 1629±608 vs. NVG: 5203±2128.6 pg/mL, P<0.001). HSP27 and HSP60 depicted a minor increase in both study groups at the end of surgery without any intergroup differences (HSP27: VG 6207.9±1252.5 vs. NVG 7424.1±2632.5; HSP60: VG 1046.2±478.8 vs. NVG 1223.5±510.1). IL-8 and CK-18 M30 evidenced the highest serum concentrations at the end of surgery (IL-8: VG 119.5±77.9 vs. NVG 148.0±184.55; CK-18 M30: VG 62.1±39.2 vs. NVG 67.5±33.9) with no differences between groups. Decreased ICAM-1 serum concentrations were detected postoperatively, however ICAM-1 concentrations on POD-1 to POD-5 showed slightly elevated concentrations in both study groups with no intergroup differences. Significantly less HSP70 was detectable in patients receiving uninterrupted mechanical lung ventilation on CPB, indicating either different inflammatory response, cellular stress or cell damage between the ventilated and non-ventilated group. These data suggest that continued mechanical ventilation has a modulatory effect on the immune response in patients after CABG surgery.

  2. 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

  3. Effect of heat release on movement characteristics of shock train in an isolator

    NASA Astrophysics Data System (ADS)

    Zhang, Chenlin; Chang, Juntao; Liu, MengMeng; Feng, Shuo; Shi, Wen; Bao, Wen

    2017-04-01

    In this paper, the effect of heat release on movement characteristics of shock train is numerically investigated in an isolator. It is found that the combustion heat release has a distinct effect on the shock train movement characteristics in the isolator. With increasing heat release, a shock train gradually forms and then propagates toward isolator entrance. In process of shock train formation, separation bubbles before injection ports entrain the high temperature burning gas into the boundary layer, which causes the shock train to shrink and stretch, and changes in configuration and number of shock waves. At the same time, the system force fluctuates. In addition, the shock train movement is divided into three stages, which have different wall pressure distribution. It is believed that these findings have a help the better understanding of the effect of heat release on the movement characteristics of shock train in an isolator.

  4. 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.

  5. Heat release in the cryogenic system of a superconducting integrated detector and the influence of heat on its operation

    NASA Astrophysics Data System (ADS)

    Kinev, N. V.; Koshelets, V. P.

    2013-03-01

    Heat release in the cryogenic system of a subterahertz-range superconducting integrated detector at ≈4.2 K is studied, and the influence of the released heat on its main characteristics is estimated. The detector chip mounted on a silicon lens is connected to a bias board by aluminum wires 25 μm in diameter, which are fixed by ultrasonic bonding. They are necessary for setting a bias current through the working components of the detector and represent an integral part of the system. The contact resistance between the wires and contact pads of the microchip is measured. The contact resistance is found to considerably exceed the resistance of the aluminum wire and, hence, makes a major contribution to heat release in the system. A "multipoint contact with one wire" technique is suggested. Tests show its efficiency: the contact resistance decreases considerably compared with the standard approach.

  6. 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.

  7. Cold energy release characteristics of an ice/air direct contact heat exchanger

    SciTech Connect

    Ohira, Akiyoshi; Yanadori, Michio; Iwabuchi, Kunihiko; Kimura, Toshikatsu; Tsubota, Yuji

    1998-12-31

    This paper deals with the cold energy release characteristics of an ice/air direct contact heat exchanger in a refined cold energy conveyance system. Characteristics of the outlet temperature, the humidity, and time history of released heat are examined when the initial height of the ice-cube-packed bed in the heat exchanger is changed. The following are the results obtained in these experiments: (1) Inlet air of 30 C is lowered to about 0 C by passing the air through the heat exchanger, and absolute humidity of the outlet air is reduced to about a quarter of that of the inlet air. (2) There is an optimum height of the ice-cube-packed bed for maximizing the amount of cold energy released. (3) This heat exchange method can supply about twice the amount of cold energy released by an ordinary fin-tube-type heat exchanger even if the air velocity in the heat exchanger is reduced to about 0.38 times that of the fin-tube-type heat exchanger.

  8. Flash-Fire Propensity and Heat-Release Rate Studies of Improved Fire Resistant Materials

    NASA Technical Reports Server (NTRS)

    Fewell, L. L.

    1978-01-01

    Twenty-six improved fire resistant materials were tested for flash-fire propensity and heat release rate properties. The tests were conducted to obtain a descriptive index based on the production of ignitable gases during the thermal degradation process and on the response of the materials under a specific heat load.

  9. 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.

  10. Heat changes during transient tension responses to small releases in active frog muscle.

    PubMed Central

    Gilbert, S H; Ford, L E

    1988-01-01

    Tension and heat production were measured in frog sartorius muscles in response to small shortening ramps (releases) at high and moderate speed. Transient tension responses to fast releases (0.1 to 0.4 mm in 1 or 4 ms) were similar to the tension transients length-clamped single fibers. Tension time courses during releases at 25 mm/s were like fiber responses calculated from the first two phases of the step responses (Ford et al., 1977). We conclude that similar crossbridge transitions produce tension transients observed in whole muscles and single fibers. Heat was absorbed during rapid tension recovery after fast releases and during the later part of releases at 25 mm/s. Variation of heat absorption with release size was compared with that of crossbridge movement predicted by the Huxley-Simmons hypothesis of force generation (Huxley and Simmons, 1971). Agreement between the two supports the conclusion that heat is absorbed by the crossbridge transitions responsible for rapid tension recovery after release. The results indicate that the entropy change of these transitions is positive. PMID:3265639

  11. Study of the heat-transfer crisis on heat-release surfaces of annular channels with swirl and transit flows

    NASA Astrophysics Data System (ADS)

    Boltenko, E. A.

    2016-10-01

    The results of the experimental study of the heat-transfer crisis on heat-release surfaces of annular channels with swirl and transit flow are presented. The experiments were carried out using electric heated annular channels with one and (or) two heat-release surfaces. For the organization of transit flow on a convex heat-release surface, four longitudinal ribs were installed uniformly at its perimeter. Swirl flow was realized using a capillary wound tightly (without gaps) on the ribs. The ratio between swirl and transit flows in the annular gap was varied by applying longitudinal ribs of different height. The experiments were carried out using a closed-type circulatory system. The experimental data were obtained in a wide range of regime parameters. Both water heated to the temperature less than the saturation temperature and water-steam mixture were fed at the inlet of the channels. For the measurement of the temperature of the heat-release surfaces, chromel-copel thermocouples were used. It was shown that the presence of swirl flow on a convex heatrelease surface led to a significant decrease in critical heat flows (CHF) compared to a smooth surface. To increase CHF, it was proposed to use the interaction of swirl flows of the heat carrier. The second swirl flow was transit flow, i.e., swirl flow with the step equal to infinity. It was shown that CHF values for a channel with swirl and transit flow in all the studied range of regime parameters was higher than CHF values for both a smooth annular channel and a channel with swirl. The empirical ratios describing the dependence of CHF on convex and concave heat-release surfaces of annular channels with swirl and transit flow on the geometrical characteristics of channels and the regime parameters were obtained. The experiments were carried out at the pressure p = 3.0-16.0 MPa and the mass velocity ρw = 250-3000 kg/(m2s).

  12. The Impact of Heat Release in Turbine Film Cooling

    DTIC Science & Technology

    2008-06-01

    AFIT/GAE/ENY/08-J02 Abstract The Ultra Compact Combustor is a design that integrates a turbine vane into the combustor flow path. Because...of the high fuel-to-air ratio and short combustor flow path, a significant potential exists for unburned fuel to enter the turbine. Using...contemporary turbine cooling vane designs, the injection of oxygen-rich turbine cooling air into a combustor flow containing unburned fuel could result in heat

  13. Nonlinear heat-release/acoustic model for thermoacoustic instability in lean premixed combustors

    SciTech Connect

    Peracchio, A.A.; Proscia, W.M.

    1999-07-01

    Lean premixed combustors, such as those used in industrial gas turbines to achieve low emissions, are often susceptible to thermoacoustic combustion instabilities, which manifest themselves as pressure and heat release oscillations in the combustor. These oscillations can result in increased noise and decreased durability due to vibration and flame motion. A physically based nonlinear parametric model has been developed that captures this instability. It describes the coupling of combustor acoustics with the rate of heat release. The model represents this coupling by accounting for the effect of acoustic pressure fluctuations on the varying fuel/air ratio being delivered to the flame, causing a fluctuating heat release due to both fuel air ratio variations and flame front oscillations. If the phasing of the fluctuating heat release and pressure are proper, an instability results that grows into a limit cycle. The nonlinear nature of the model predicts the onset of the instability and additionally captures the resulting limit cycle. Tests of a lean premixed nozzle at engine scale and engine operating conditions in the UTRC single nozzle rig, conducted under DARPA contract, exhibited instabilities. Parameters from the model were adjusted so that analytical results were consistent with relevant experimental data from this test. The parametric model captures the limit cycle behavior over a range of mean fuel air ratios, showing the instability amplitude (pressure and heat release) to increase and limit cycle frequency to decrease as mean fuel air ratio is reduced.

  14. 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

    ... calorimeter to determine their heat of combustion and other properties; to full-scale, in which horizontal... COMMISSION NUREG/CR-7010, Cable Heat Release, Ignition, and Spread in Tray Installations During Fire... Commission has issued for public comment a document entitled: ``NUREG/CR-7010, Cable Heat Release,...

  15. Heat Induced Capsid Disassembly and DNA Release of Bacteriophage λ

    PubMed Central

    Qiu, Xiangyun

    2012-01-01

    Successive structural changes of bacteriophage upon heating were characterized with quantitative experimental methods. In the commonly used Tris-Mg buffer, differential scanning calorimetry measurements first established that the protein capsid of phage melts at 87°C and its genomic DNA melts at 91°C. Interestingly, prior to the capsid melting, DNA was found to escape out of the capsid and subject to DNase digestion above 68°C, as concluded from light scattering, UV absorption, and electron microscopy studies. Further investigations indicated distinct temperature-dependent behaviors of the three phage proteins. Around 68°C, disruption of the tail first occurs and leads to the escape of DNA; above the capsid melting temperature of 87°C, the auxiliary protein gpD of the phage head remains soluble in solution and resists centrifugal sedimentation, whereas the major capsid protein gpE is easily precipitated and likely exists as aggregates. PMID:22808062

  16. The effect of fire retardants on the heat-release rate of building materials

    NASA Astrophysics Data System (ADS)

    Martin, S. B.; Inman, L. B.

    1981-07-01

    A method was developed for making up thick cellulosic specimens with thermocouples implanted at various depths to determine the time dependent temperature profiles when exposed to external radiant fluxes. Specimens of alpha cellulose, both untreated and treated with 2 percent by weight of Na2B4O7, were exposed to an applied radiant flux of 3.7 W/sq cm in the heat release rate calorimeter in order to examine the effect of the fire retardants on the heat release rate. The results on a limited number of tests suggest that the char enhancement, produced by the presence of Na2B4O7, reduces the heat release rate mainly by the reduction of the caloric value of the volatile products rather than by the insulating effect of the increased char layer thickness.

  17. 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. (c) 2008 American Institute of Physics.

  18. The role of latent heat release in baroclinic waves - Without beta-effect

    NASA Technical Reports Server (NTRS)

    Tang, C.-M.; Fichtl, G. H.

    1983-01-01

    An attempt is made to understand the role of latent heat release in the development of baroclinic waves by developing the analytical theory of two-level, quasi-geostrophic baroclinic waves proposed by Phillips (1954) without beta effect, for the case of an atmosphere initially saturated with water vapor and subject to pseudo-adiabatic lifting and dry adiabatic subsistence. The saturated atmosphere condition precludes consideration of conditional convective instability. A consideration of disturbances at each level which depends only on the zonal coordinates and time results in a set of differential equations which is linear in all respects except for the latent heating term in the thermodynamic energy equation. A fundamental nonlinearity is present in this model which is due to heating via the release of latent heat when vertical motion is upward.

  19. Nucleation of cracks in a perforated heat-releasing material with temperature-dependent elastic properties

    NASA Astrophysics Data System (ADS)

    Vagari, A. R.; Mirsalimov, V. M.

    2012-07-01

    A mathematical model of crack nucleation in a perforated heat-releasing material attenuated by a biperiodic system of cooling cylindrical channels with a circular cross section is constructed. Solving the problem of equilibrium of an isotropic perforated heat-releasing material with temperature-dependent properties containing nucleating cracks is reduced to solving systems of algebraic and nonlinear singular integral equations with a Cauchy-type kernel. The forces in crack nucleation regions are found by using the solution of these equations. The condition of crack emergence is formulated with allowance for the criterion of ultimate stretching of bonds in the material.

  20. 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).

  1. Modeling drug release from functionalized magnetic nanoparticles actuated by non-heating low frequency magnetic field

    NASA Astrophysics Data System (ADS)

    Golovin, Y.; Golovin, D.; Klyachko, N.; Majouga, A.; Kabanov, A.

    2017-02-01

    Various plausible acceleration mechanisms of drug release from nanocarriers composed of a single-domain magnetic nanoparticle core with attached long macromolecule chains activated by low frequency non-heating alternating magnetic field (AMF) are discussed. The most important system characteristics affecting the AMF exposure impact are determined. Impact of several reasonable mechanisms is estimated analytically or obtained using numerical modeling. Some conditions providing manifold release acceleration as a result from exposure in AMF are found.

  2. 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.

  3. Critical heat flux and dynamics of boiling in nanofluids at stepwise heat release

    NASA Astrophysics Data System (ADS)

    Moiseev, M. I.; Kuznetsov, D. V.

    2016-10-01

    In this paper results of an experimental study on critical heat flux and dynamics of boiling crisis onset in nanofluids at stepwise heat generation are presented. Freon R21 with three types of nanoparticles - SiO2, Cu and Al2O3 was used as test fluid. Critical heat fluxes and temperatures of boiling initiation were obtained. It was shown that the addition of nanoparticles increased CHF at stepwise heat generation by up to 21%. Under conditions of the experiment transition to film boiling occurred via evaporation fronts. Data on propagation velocity and structure of evaporation fronts were obtained; the spectral analysis of fluctuations of the evaporation front interface was carried out. The characteristic frequencies and amplitudes of interface fluctuations were determined depending on the velocity of evaporation front propagation. It was shown that the addition of nano-sized particles significantly affects development of interface instability and increases the front velocity.

  4. Interaction of Two Micro-slot Flames: Heat Release Rate and Flame Shape

    NASA Astrophysics Data System (ADS)

    Kuwana, K.; Kato, S.; Kosugi, A.; Hirasawa, T.; Nakamura, Y.

    2014-11-01

    This paper studies the interaction between two identical micro-slot diffusion flames. Here, we define a micro-slot flame as a slot flame of which the slot width is less than about 1 mm. Because of its smallness, a micro-slot flame has a high heating density and can be used as a small heat source. However, the heat release rate of a single micro-slot flame is limited, and therefore, multiple micro-slot flames may be used to increase total heat release rate. As a first step, this paper considers a situation in which two micro-slot flames are used with certain burner spacing. When two diffusion flames are placed closely, flame shape changes from that of an isolated flame. Studying such flame shape change and resultant change in total heat release rate is the topic of this paper. Experiment is conducted and total heat release rate is measured by integrating CH* chemiluminescence recorded using a CCD camera and an optical filter of the wavelength of 430 nm. Two different burner materials, copper and glass, are tested to study the effect of heat loss to burners. An analytical model is applied to predict flame shape. In addition to the classical Burke-Schumann assumptions, two slot flames are modeled as line sources with zero width, enabling a simple analytical solution for the critical burner spacing at which two flames touch each other. The critical burner spacing is a key parameter that characterizes the interaction between two micro-slot flames. Computational fluid dynamics (CFD) simulations are then conducted to test the validity of the present theory. CFD results are favorably compared with the theoretical prediction.

  5. Extracellular vesicles released following heat stress induce bystander effect in unstressed populations.

    PubMed

    Bewicke-Copley, Findlay; Mulcahy, Laura Ann; Jacobs, Laura Ann; Samuel, Priya; Akbar, Naveed; Pink, Ryan Charles; Carter, David Raul Francisco

    2017-01-01

    Cells naïve to stress can display the effects of stress, such as DNA damage and apoptosis, when they are exposed to signals from stressed cells; this phenomenon is known as the bystander effect. We previously showed that bystander effect induced by ionising radiation are mediated by extracellular vesicles (EVs). Bystander effect can also be induced by other types of stress, including heat shock, but it is unclear whether EVs are involved. Here we show that EVs released from heat shocked cells are also able to induce bystander damage in unstressed populations. Naïve cells treated with media conditioned by heat shocked cells showed higher levels of DNA damage and apoptosis than cells treated with media from control cells. Treating naïve cells with EVs derived from media conditioned by heat shocked cells also induced a bystander effect when compared to control, with DNA damage and apoptosis increasing whilst the level of cell viability was reduced. We demonstrate that treatment of naïve cells with heat shocked cell-derived EVs leads to greater invasiveness in a trans-well Matrigel assay. Finally, we show that naïve cells treated with EVs from heat-shocked cells are more likely to survive a subsequent heat shock, suggesting that these EVs mediate an adaptive response. We propose that EVs released following stress mediate an intercellular response that leads to apparent stress in neighbouring cells but also greater robustness in the face of a subsequent insult.

  6. Effect of Melt Superheating Treatment on the Latent Heat Release of Sn

    NASA Astrophysics Data System (ADS)

    Xu, Junfeng; Dang, Bo; Fan, Dandan; Jian, Zengyun

    2017-03-01

    The accuracy of the baseline evaluation is of importance for calculating the transition enthalpy such as the latent heat of the crystallization. This study demonstrates the modified method of the equivalent non-latent heat baseline, by which the transition enthalpy can be measured accurately according to the transition peak in differential scanning calorimetric curve. With this method, the effect of melt superheating treatment time on the latent heat release upon the solidification of tin is investigated. The results show that the latent heat increases by increasing the treatment time, and is close to a constant when the treatment time is large enough, indicating the homogeneous system. And then, a simple model is established to describe the changes of the crystallization latent heat with the treatment time, which is confirmed by the experimental data of Sn.

  7. Effect of Melt Superheating Treatment on the Latent Heat Release of Sn

    NASA Astrophysics Data System (ADS)

    Xu, Junfeng; Dang, Bo; Fan, Dandan; Jian, Zengyun

    2016-12-01

    The accuracy of the baseline evaluation is of importance for calculating the transition enthalpy such as the latent heat of the crystallization. This study demonstrates the modified method of the equivalent non-latent heat baseline, by which the transition enthalpy can be measured accurately according to the transition peak in differential scanning calorimetric curve. With this method, the effect of melt superheating treatment time on the latent heat release upon the solidification of tin is investigated. The results show that the latent heat increases by increasing the treatment time, and is close to a constant when the treatment time is large enough, indicating the homogeneous system. And then, a simple model is established to describe the changes of the crystallization latent heat with the treatment time, which is confirmed by the experimental data of Sn.

  8. Role of buoyancy and heat release in fire modeling, propagation, and instability

    Treesearch

    Shahid M. Mughal; Yousuff M. Hussaini; Scott L. Goodrick; Philip Cunningham

    2007-01-01

    In an investigation of the dynamics of coupled fluid-combustion-buoyancy driven problems, an idealised model formulation is used to investigate the role of buoyancy and heat release in an evolving boundary layer, with particular emphasis on examining underlying fluid dynamics to explain observed phenomena arising in forest fire propagation. The role played by the...

  9. 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.

  10. Coupling between entropy and unsteady heat release in a thermoacoustic system with a mean flow

    NASA Astrophysics Data System (ADS)

    Li, Lei; Zhao, Dan

    2016-11-01

    In this work, the coupling between entropy and unsteady heat release in a one dimensional duct in the presence of a mean flow is considered. As acoustic disturbances impinge on a compact heat source enclosed in the duct, entropy disturbances are generated. The transfer function between the generated entropy waves and oncoming flow velocity fluctuations is deduced by conducting order analysis of the linearized governing equations. The effects of the mean flow are emphasized for different forms of unsteady heat release model. It is shown that there is a strong coupling between entropy, heat release, mean flow and acoustic impedance at the heat source. To validate our theoretical analysis, numerical investigation is conducted by using a low order model. Comparing the theoretical and the low order model's results reveals that a good agreement is observed. It is found that when the mean flow Mach number is not negligible, the term of O(M1) in the identified entropy transfer function is as important as that of O(M0). Neglecting the term of O(M1) may lead to wrong prediction of the entropy waves produced in the system.

  11. Impact of heat release on strain rate field in turbulent premixed Bunsen flames

    SciTech Connect

    Coriton, Bruno Rene Leon; Frank, Jonathan H.

    2016-08-10

    The effects of combustion on the strain rate field are investigated in turbulent premixed CH4/air Bunsen flames using simultaneous tomographic PIV and OH LIF measurements. Tomographic PIV provides three-dimensional velocity measurements, from which the complete strain rate tensor is determined. The OH LIF measurements are used to determine the position of the flame surface and the flame-normal orientation within the imaging plane. This combination of diagnostic techniques enables quantification of divergence as well as flame-normal and tangential strain rates, which are otherwise biased using only planar measurements. Measurements are compared in three lean-to-stoichiometric flames that have different amounts of heat release and Damköhler numbers greater than unity. The effects of heat release on the principal strain rates and their alignment relative to the local flame normal are analyzed. The extensive strain rate preferentially aligns with the flame normal in the reaction zone, which has been indicated by previous studies. The strength of this alignment increases with increasing heat release and, as a result, the flame-normal strain rate becomes highly extensive. These effects are associated with the gas expansion normal to the flame surface, which is largest for the stoichiometric flame. In the preheat zone, the compressive strain rate has a tendency to align with the flame normal. Away from the flame front, the flame – strain rate alignment is arbitrary in both the reactants and products. The flame-tangential strain rate is on average positive across the flame front, and therefore the turbulent strain rate field contributes to the enhancement of scalar gradients as in passive scalar turbulence. As a result, increases in heat release result in larger positive values of the divergence as well as flame-normal and tangential strain rates, the tangential strain rate has a weaker dependence on heat release than the flame-normal strain rate and the

  12. Impact of heat release on strain rate field in turbulent premixed Bunsen flames

    SciTech Connect

    Coriton, Bruno Rene Leon; Frank, Jonathan H.

    2016-08-10

    The effects of combustion on the strain rate field are investigated in turbulent premixed CH4/air Bunsen flames using simultaneous tomographic PIV and OH LIF measurements. Tomographic PIV provides three-dimensional velocity measurements, from which the complete strain rate tensor is determined. The OH LIF measurements are used to determine the position of the flame surface and the flame-normal orientation within the imaging plane. This combination of diagnostic techniques enables quantification of divergence as well as flame-normal and tangential strain rates, which are otherwise biased using only planar measurements. Measurements are compared in three lean-to-stoichiometric flames that have different amounts of heat release and Damköhler numbers greater than unity. The effects of heat release on the principal strain rates and their alignment relative to the local flame normal are analyzed. The extensive strain rate preferentially aligns with the flame normal in the reaction zone, which has been indicated by previous studies. The strength of this alignment increases with increasing heat release and, as a result, the flame-normal strain rate becomes highly extensive. These effects are associated with the gas expansion normal to the flame surface, which is largest for the stoichiometric flame. In the preheat zone, the compressive strain rate has a tendency to align with the flame normal. Away from the flame front, the flame – strain rate alignment is arbitrary in both the reactants and products. The flame-tangential strain rate is on average positive across the flame front, and therefore the turbulent strain rate field contributes to the enhancement of scalar gradients as in passive scalar turbulence. As a result, increases in heat release result in larger positive values of the divergence as well as flame-normal and tangential strain rates, the tangential strain rate has a weaker dependence on heat release than the flame-normal strain rate and the

  13. 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

  14. 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.

  15. Impact of heat release on strain rate field in turbulent premixed Bunsen flames

    DOE PAGES

    Coriton, Bruno Rene Leon; Frank, Jonathan H.

    2016-08-10

    The effects of combustion on the strain rate field are investigated in turbulent premixed CH4/air Bunsen flames using simultaneous tomographic PIV and OH LIF measurements. Tomographic PIV provides three-dimensional velocity measurements, from which the complete strain rate tensor is determined. The OH LIF measurements are used to determine the position of the flame surface and the flame-normal orientation within the imaging plane. This combination of diagnostic techniques enables quantification of divergence as well as flame-normal and tangential strain rates, which are otherwise biased using only planar measurements. Measurements are compared in three lean-to-stoichiometric flames that have different amounts of heatmore » release and Damköhler numbers greater than unity. The effects of heat release on the principal strain rates and their alignment relative to the local flame normal are analyzed. The extensive strain rate preferentially aligns with the flame normal in the reaction zone, which has been indicated by previous studies. The strength of this alignment increases with increasing heat release and, as a result, the flame-normal strain rate becomes highly extensive. These effects are associated with the gas expansion normal to the flame surface, which is largest for the stoichiometric flame. In the preheat zone, the compressive strain rate has a tendency to align with the flame normal. Away from the flame front, the flame – strain rate alignment is arbitrary in both the reactants and products. The flame-tangential strain rate is on average positive across the flame front, and therefore the turbulent strain rate field contributes to the enhancement of scalar gradients as in passive scalar turbulence. As a result, increases in heat release result in larger positive values of the divergence as well as flame-normal and tangential strain rates, the tangential strain rate has a weaker dependence on heat release than the flame-normal strain rate and the

  16. 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

  17. 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.

  18. Heat produces uteroplacental circulatory disturbance in pregnant rats through action of corticotropin releasing hormone (CRH).

    PubMed

    Nakamura, H; Nagase, H; Ogino, K; Hatta, K; Matsuzaki, I

    2000-01-01

    There is some evidence showing an existence of corticotropin releasing hormone (CRH) and opioid peptides, including beta-endorphin (betaEP), in human placenta, whereas physiological roles of the placental peptides in response to stress remain to be elucidated. To clarify the involvement of CRH and opioid system in the uteroplacental circulation in the pregnant rats exposed to heat, we examined the effects of heat and intravenous administration of CRH receptor antagonist alpha-helical CRH (9-41) on the uteroplacental blood flow, as well as blood CRH, and blood and placental betaEP in pregnant rats. Heat did not change uterine blood flow in virgin rats, but reduced uteroplacental blood flow in pregnant rats. The reduced uteroplacental blood flow induced by heat in pregnant rats was reversed by the administration of alpha-helical CRH. Independent of the status of pregnancy, heat increased blood CRH, which was not reversed by alpha-helical CRH. Although heat did not change placental betaEP, alpha-helical CRH reduced blood and placenta betaEP in pregnant rats. These results suggest that the uteroplacental circulatory disturbance caused by heat is mediated by CRH, possibly through the involvement of CRH receptor in rat placenta. The placental opioid system seems unlikely to be involved in the mediation of uteroplacental circulation.

  19. 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

  20. 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

  1. Effects of heat release on the structure and stability of a coflowing, chemically reacting jet

    NASA Technical Reports Server (NTRS)

    Mahalingam, S.; Cantwell, B. J.; Ferziger, J. H.

    1989-01-01

    It is shown how linear stability analysis and full simulations can be used to study the stability and structure of reacting flows. The small effect of gravity on steady laminar flame heights can be modeled if allowance is made for the density variations due to heat release. It is found that cold transitional jet simulations yield perturbation growth rates which are consistent with the predictions of the inviscid stability theory.

  2. 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.

  3. A fast and powerful release mechanism based on pulse heating of shape memory wires

    NASA Astrophysics Data System (ADS)

    Malka, Yoav; Shilo, Doron

    2017-09-01

    This article presents a novel actuator and a new concept for a release mechanism that are especially useful in applications that require fast motion of large masses over long distances. The actuator is based on ultra-fast pulse heating of NiTi wires, which provide a unique combination of large work per volume, short response time and enhanced energy efficiency. The release mechanism utilizes the fast and powerful actuator to form conditions in which the latch (safety pin) moves faster than the deployed device. As a result, the contact between these two masses is disconnected and the resulting friction forces are decreased to approximately zero. The actuator and release mechanism address the two major drawbacks of conventional shape memory alloy (SMA) actuators: slow actuation time and low energy efficiency. Using a dedicated setup, the experimental results validate the disconnection between the masses and map the effects of several variables on the performance of the actuator and release mechanism. In particular, we map the energetic efficiency and find the optimal operating conditions for a successful release using a minimal amount of input energy. At the optimal conditions, the actuator response time and the consumed input energy are smaller by an order of magnitude with respect to performances of previous SMA-based release mechanisms with comparable requirements.

  4. 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.

  5. Effect of heat release on the stability of compressible reacting mixing layer

    NASA Technical Reports Server (NTRS)

    Shin, Dong-Shin; Ferziger, J. H.

    1991-01-01

    Reacting free shear layers are of fundamental importance in many industrial systems including gas turbine combustors and rockets. Efficient propulsion systems are essential for air breathing supersonic ramjets in the high Mach number range. A limiting factor in these engines is the time for fuel and oxidizer to mix in the combustion chamber; for fast mixing, the flow must be vigorously turbulent which requires the laminar flow to be unstable. Understanding the stability characteristics of compressible reacting free shear layers is, therefore, very important and may allow one to control the flow. Low speed shear layers are highly unstable but, as chemical reaction and compressibility effects tend to stabilize them, it is important to investigate the stability of high speed reacting mixing layers. The latter consists of two fluid streams containing fuel and oxidizer respectively, and the conclusions are expected to apply, with quantitative modifications, to other shear flows, e.g., jets. Since low speed reacting cases have been studied earlier, we concentrate on the effects of Mach number and heat release. We are primarily interested in solving the stability problem over a large range of Mach number and heat release. In order to understand the effect of the heat release on the stability of this flow, one must first study the characteristics of the non-reacting flow. Inviscid theory is a reliable guide for understanding stability of compressible shear flows at moderate and large Reynolds numbers and is the basis for this work.

  6. 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

    2015-01-08

    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.

  7. 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

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

    DOE PAGES

    Riedel, Clement; Gabizon, Ronen; Wilson, Christian A. M.; ...

    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

  9. 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.

  10. Bacterial Infection Elicits Heat Shock Protein 72 Release from Pleural Mesothelial Cells

    PubMed Central

    Varano della Vergiliana, Julius F.; Lansley, Sally M.; Porcel, Jose M.; Bielsa, Silvia; Brown, Jeremy S.; Creaney, Jenette; Temple, Suzanna E. L.; Waterer, Grant W.; Lee, Y. C. Gary

    2013-01-01

    Heat shock protein 70 (HSP70) has been implicated in infection-related processes and has been found in body fluids during infection. This study aimed to determine whether pleural mesothelial cells release HSP70 in response to bacterial infection in vitro and in mouse models of serosal infection. In addition, the in vitro cytokine effects of the HSP70 isoform, Hsp72, on mesothelial cells were examined. Further, Hsp72 was measured in human pleural effusions and levels compared between non-infectious and infectious patients to determine the diagnostic accuracy of pleural fluid Hsp72 compared to traditional pleural fluid parameters. We showed that mesothelial release of Hsp72 was significantly raised when cells were treated with live and heat-killed Streptococcus pneumoniae. In mice, intraperitoneal injection of S. pneumoniae stimulated a 2-fold increase in Hsp72 levels in peritoneal lavage (p<0.01). Extracellular Hsp72 did not induce or inhibit mediator release from cultured mesothelial cells. Hsp72 levels were significantly higher in effusions of infectious origin compared to non-infectious effusions (p<0.05). The data establish that pleural mesothelial cells can release Hsp72 in response to bacterial infection and levels are raised in infectious pleural effusions. The biological role of HSP70 in pleural infection warrants exploration. PMID:23704948

  11. 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

  12. Gas dynamics of heat-release-induced waves in supercritical fluids: revisiting the Piston Effect

    NASA Astrophysics Data System (ADS)

    Migliorino, Mario Tindaro; Scalo, Carlo

    2016-11-01

    We investigate a gasdynamic approach to the modeling of heat-release-induced compression waves in supercritical fluids. We rely on highly resolved one-dimensional fully compressible Navier-Stokes simulations of CO2 at pseudo-boiling conditions in a closed duct inspired by the experiments of Miura et al.. Near-critical fluids exhibit anomalous variations of thermodynamic variables taken into account by adopting the Peng-Robinson equation of state and Chung's Method. An idealized heat source is applied, away from the boundaries, resulting in the generation of compression waves followed by contact discontinuities bounding a region of hot expanding fluid. For higher heat-release rates such compressions are coalescent with distinct shock-like features (i.e. non-isentropicity and propagation Mach numbers measurably greater than unity) and a non-uniform post-shock state, not present in ideal gas simulations, caused by the highly nonlinear equation of state. Thermoacoustic effects are limited to: (1) a one-way/one-time thermal-to-acoustic energy conversion, and (2) cumulative non-isentropic bulk heating due to the resonating compression waves, resulting in what is commonly referred to as the Piston Effect.

  13. 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.

  14. 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

  15. 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

  16. 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

  17. Near-infrared-induced heating of confined water in polymeric particles for efficient payload release.

    PubMed

    Viger, Mathieu L; Sheng, Wangzhong; Doré, Kim; Alhasan, Ali H; Carling, Carl-Johan; Lux, Jacques; de Gracia Lux, Caroline; Grossman, Madeleine; Malinow, Roberto; Almutairi, Adah

    2014-05-27

    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.

  18. Inflammatory stress of pancreatic beta cells drives release of extracellular heat shock protein 90α.

    PubMed

    Ocaña, Gail J; Pérez, Liliana; Guindon, Lynette; Deffit, Sarah N; Evans-Molina, Carmella; Thurmond, Debbie C; Blum, Janice S

    2017-02-11

    A major obstacle in predicting and preventing the development of autoimmune type 1 diabetes (T1D) in at-risk individuals is the lack of well-established early biomarkers indicative of ongoing beta cell stress during the pre-clinical phase of disease. Recently, serum levels of the alpha cytoplasmic isoform of heat shock protein (HSP) 90 were shown to be elevated in individuals with new-onset T1D. We therefore hypothesized HSP90α could be released from beta cells in response to cellular stress and inflammation associated with the earliest stages of T1D. Here, human beta cell lines and cadaveric islets released HSP90α in response to stress induced by treatment with a combination of pro-inflammatory cytokines including IL-1β, TNF-α, and IFN-γ. Mechanistically, HSP90α release was found to be driven by cytokine-induced endoplasmic reticulum (ER) stress mediated by c-Jun N-terminal kinase (JNK), a pathway that can eventually lead to beta cell apoptosis. Cytokine-induced beta cell HSP90α release and JNK activation were significantly reduced by pre-treating cells with the ER stress-mitigating chemical chaperone tauroursodeoxycholic acid (TUDCA). HSP90α release by cells may thus be a sensitive indicator of stress during inflammation and a useful tool in assessing therapeutic mitigation of cytokine-induced cell damage linked to autoimmunity. This article is protected by copyright. All rights reserved.

  19. Inadequate heat release from the human brain during prolonged exercise with hyperthermia

    PubMed Central

    Nybo, Lars; Secher, Niels H; Nielsen, Bodil

    2002-01-01

    Brain temperature appears to be an important factor affecting motor activity, but it is not known to what extent brain temperature increases during prolonged exercise in humans. Cerebral heat exchange was therefore evaluated in seven males during exercise with and without hyperthermia. Middle cerebral artery mean blood velocity (MCA Vmean) was continuously monitored while global cerebral blood flow (CBF) and cerebral energy turnover were determined at the end of the two exercise trials in three subjects. The arterial to venous temperature difference across the brain (v-aDtemp) was determined via thermocouples placed in the internal jugular vein and in the aorta. The jugular venous blood temperature was always higher than that of the arterial blood, demonstrating that heat was released via the CBF during the normothermic as well as the hyperthermic exercise condition. However, heat removal via the jugular venous blood was 30 ± 6 % lower during hyperthermia compared to the control trial. The reduced heat removal from the brain was mainly a result of a 20 ± 6 % lower CBF (22 ± 9 % reduction in MCA Vmean), because the v-aDtemp was not significantly different in the hyperthermic (0.20 ± 0.05 °C) compared to the control trial (0.22 ± 0.05 °C). During hyperthermia, the impaired heat removal via the blood was combined with a 7 ± 2 % higher heat production in the brain and heat was consequently stored in the brain at a rate of 0.20 ± 0.06 J g−1 min−1. The present results indicate that the average brain temperature is at least 0.2 °C higher than that of the body core during exercise with or without hyperthermia. PMID:12456844

  20. 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.

  1. Heat-driven release of a drug molecule from carbon nanotubes: a molecular dynamics study.

    PubMed

    Chaban, Vitaly V; Savchenko, Timur I; Kovalenko, Sergiy M; Prezhdo, Oleg V

    2010-10-28

    Hydrophobicity and the 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. 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 time scales 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 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.

  2. Determination of volatile chemicals released from microwave-heat-susceptor food packaging.

    PubMed

    McNeal, T P; Hollifield, H C

    1993-01-01

    Microwave heat susceptors that convert electromagnetic energy to heat attain high temperatures that make it possible to cook some foods to golden crispness in a microwave oven. Susceptors are typically packaged with foods intended for microwave use, e.g., waffles, pizzas, and french fries. The high temperatures > 302 degrees F used to cook some foods release trace levels of volatile chemicals from metalized polyester film, adhesive, and paper packaging materials; these volatile chemicals may be absorbed by the food. We simulated microwave susceptor cooking conditions and developed protocols by using headspace concentration capillary gas chromatography and mass spectrometry to identify volatile chemicals released from heated susceptors. We purchased a limited, cross-sectional sample of local retail microwave food products packaged with susceptors and used our protocol to analyze 10 different susceptor products. Although more than 140 unique chromatographic peaks were tabulated, only 44 volatile chemicals were identified, including 1,1,1-trichloroethane, benzene, and 2-(2-butoxyethoxy)ethanol, which were derived primarily from the paper and adhesive susceptor components. No one susceptor contained all the identified substances. The standard additions technique was the preferred method for quantitation. Trichloroethane and 2-(2-butoxyethoxy)ethanol were present in several products at 75-122 micrograms/in.2 of susceptor surface area. Benzene was found in 3 susceptors at < or = 0.22 microgram/in.2 levels. Examination indicates that adhesives used in more recent susceptor products were reformulated to remove even this trace level of benzene.

  3. Factors Affecting Release of Heat-Labile Enterotoxin by Enterotoxigenic Escherichia coli

    PubMed Central

    Kunkel, Steven L.; Robertson, Donald C.

    1979-01-01

    Various conditions affecting the release of heat-labile enterotoxin (LT) by enterotoxigenic Escherichia coli have been examined. The pH of a defined medium containing three amino acids, M-9 salts, and 0.5% glucose decreased to less than 7.0 in early log phase of growth, and no extracellular LT was detected. Adjustment of the pH at 8 h from 6.0 to 8.0 resulted in a concomitant increase in LT activity in culture supernatants. The release of cell-associated LT was significantly reduced by preincubation with protease inhibitors and increased by preincubation with trypsin. Cell-associated LT was not released by pH adjustment of cells grown at 21°C; however, polymyxin B treatment released a toxin species active in only the pigeon erythrocyte lysate (PEL) assay system. As the growth temperature was increased, polymyxin B released toxin species which exhibited both PEL and Y-1 adrenal tumor cell activity. Polymyxin B extracts of enterotoxigenic E. coli in early log phase grown at 37°C possessed only PEL activity, whereas extracts from cells in late-log and stationary phases had biological activity in both assay systems. Also, LT released by pH adjustment from mid-log to stationary phase was active in both PEL and Y-1 adrenal tumor cell assays. Gel electrophoresis of polymyxin B extracts revealed at least three molecular weight species active in either the PEL (22,000 daltons and 30,000 daltons) or both the PEL and the Y-1 adrenal tumor cell assay (72,000 daltons), depending on the growth temperature. These observations may help to explain the chemical and biological heterogeneity of most LT preparations and facilitate purification of LT by increasing the yield of enterotoxin. PMID:37162

  4. 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.

  5. Heat-killed Lactobacillus rhamnosus GG modulates urocortin and cytokine release in primary trophoblast cells.

    PubMed

    Bloise, E; Torricelli, M; Novembri, R; Borges, L E; Carrarelli, P; Reis, F M; Petraglia, F

    2010-10-01

    A number of studies are showing that probiotic treatment induces an anti-inflammatory state. Intrauterine infection can lead to preterm delivery by modulating immune function and efforts to prevent this condition are ongoing nowadays. Lactobacillus rhamnosus GG (LGG) is a probiotic known to ameliorate inflammation by increasing local anti-inflammatory mediators in urinary and gastrointestinal tracts. The present study then analyzed the effect of heat-killed LGG over β-hCG, progesterone, interleukins (IL) 4 and 10, tumor necrosis factor-α (TNF-α), corticotropin releasing hormone (CRH) and urocortin (Ucn) release by primary trophoblast cells. Normal human term placentas (n = 6) were collected and purified trophoblast cells were incubated in the presence of LGG, lipopolysaccharide (LPS) or either LGG + LPS during 3 h, after which the target substances were quantified by ELISA and real-time PCR. LGG did not affect β-hCG, progesterone, or CRH secretion. Conversely, LGG increased IL-4 protein and mRNA expression (P < 0.05) while IL-10 and Ucn secretion were increased in a dose dependent manner and the highest dose of LGG increased significantly IL-10 mRNA (P < 0.05). LGG did not alter TNF-α, while LPS exposure increased TNF-α protein (P < 0.001) and mRNA expression (P < 0.01). Conversely, LGG treatment reversed LPS-induced TNF-α release at both protein (P < 0.01) and mRNA levels (P < 0.05) in a dose dependent fashion. In conclusion, LGG stimulates IL-4, IL-10 and Ucn expression and reverses LPS-induced TNF-α release from trophoblast cells, with no change in β-hCG or progesterone release, suggesting that this probiotic may play a role as an immunomodulatory agent in human placenta without altering basic trophoblast functions. Copyright © 2010. Published by Elsevier Ltd.

  6. Planar laser-induced fluorescence imaging of flame heat release rate

    SciTech Connect

    Paul, P.H.; Najm, H.N.

    1997-12-12

    Local heat release rate represents one of the most interesting experimental observables in the study of unsteady reacting flows. The direct measure of burning or heat release rate as a field variable is not possible. Numerous experimental investigations have relied on inferring this type of information as well as flame front topology from indirect measures which are presumed to be correlated. A recent study has brought into question many of the commonly used flame front marker and burning rate diagnostics. This same study found that the concentration of formyl radical offers the best possibility for measuring flame burning rate. However, primarily due to low concentrations, the fluorescence signal level from formyl is too weak to employ this diagnostic for single-pulse measurements of turbulent reacting flows. In this paper the authors describe and demonstrate a new fluorescence-based reaction front imaging diagnostic suitable for single-shot applications. The measurement is based on taking the pixel-by-pixel product of OH and CH{sub 2}O planar laser-induced fluorescence images to yield an image closely related to a reaction rate. The spectroscopic and collisional processes affecting the measured signals are discussed and the foundation of the diagnostic, as based on laminar and unsteady flame calculations, is presented. The authors report the results of applying this diagnostic to the study of a laminar premixed flame subject to an interaction with an isolated line-vortex pair.

  7. Measurements of the heat release rate integral in turbulent premixed stagnation flames with particle image velocimetry

    SciTech Connect

    Chen, Yung-Cheng; Kim, Munki; Han, Jeongjae; Yun, Sangwook; Yoon, Youngbin

    2008-08-15

    A new definition of turbulent consumption speed is proposed in this work that is based on the heat release rate integral, rather than the mass burning rate integral. Its detailed derivation and the assumptions involved are discussed in a general context that applies to all properly defined reaction progress variables. The major advantage of the proposed definition is that it does not require the thin-flame assumption, in contrast to previous definitions. Experimental determination of the local turbulent displacement speed, S{sub D}, and the local turbulent consumption speed, S{sub C}, is also demonstrated with the particle image velocimetry technique in three turbulent premixed stagnation flames. The turbulence intensity of these flames is of the same order of the laminar burning velocity. Based on the current data, a model equation for the local mean heat release rate is proposed. The relationship between S{sub D} and S{sub C} is discussed along with a possible modeling approach for the turbulent displacement speed. (author)

  8. δ-FeOOH: a superparamagnetic material for controlled heat release under AC magnetic field

    NASA Astrophysics Data System (ADS)

    Chagas, Poliane; da Silva, Adilson Cândido; Passamani, Edson Caetano; Ardisson, José Domingos; de Oliveira, Luiz Carlos Alves; Fabris, José Domingos; Paniago, Roberto M.; Monteiro, Douglas Santos; Pereira, Márcio César

    2013-04-01

    Experimental evidences on its in vitro use reveal that δ-FeOOH is a material that release-controlled amount of heat if placed under an AC magnetic field. δ-FeOOH nanoparticles were prepared by precipitating Fe(OH)2 in alkaline solution followed by fast oxidation with H2O2. XRD and 57Fe Mössbauer spectroscopy data confirmed that δ-FeOOH is indeed the only iron-bearing compound in the produced sample. TEM images evidence that the averaged particle sizes for this δ-FeOOH sample is 23 nm. Magnetization measurements indicate that these δ-FeOOH particles behave superparamagnetically at 300 K; its saturation magnetization was found to be 13.2 emu g-1; the coercivity and the remnant magnetization were zero at 300 K. The specific absorption rate values at 225 kHz were 2.1, 6.2, and 34.2 W g-1, under 38, 64, and 112 mT, respectively. The release rate of heat can be directly controlled by changing the mass of δ-FeOOH nanoparticles. In view of these findings, the so-prepared δ-FeOOH is a real alternative to be further tested as a material for medical practices in therapies involving magnetic hyperthermia as in clinical oncology.

  9. T cell-mediated lethal shock triggered in mice by the superantigen staphylococcal enterotoxin B: critical role of tumor necrosis factor

    PubMed Central

    1992-01-01

    Because mice are more resistant than humans to the pathogenic effects of bacterial toxins, we used D-Galactosamine- (D-Gal) sensitized mice as a model system to evaluate potential toxic shock symptoms triggered by the superantigen staphylococcal enterotoxin B (SEB). We show that similar to endotoxin (lipopolysaccharide) [LPS], the exotoxin SEB causes lethal shock within 8 h in D-Gal-sensitized mice, inducing 100% and about 50% lethality with 20 and 2 micrograms SEB, respectively. The lethal shock triggered by the superantigen SEB is mediated by T cells, a conclusion based on the observation that T cell repopulation of SCID mice conferred sensitivity to SEB. Since CSA also conferred protection, the role of T cell-derived lymphokines in mediating lethal shock was evaluated. Within 30-60 min after SEB injection, serum tumor necrosis factor (TNF) levels peaked, followed immediately by interleukin-2 (IL- 2). Serum-borne lymphokines were detected well in advance of signs of T cell activation, as assessed by IL-2 receptor expression of SEB- reactive V beta 8+ T cells. Passive immunization with anti-TNF- alpha/beta-neutralizing monoclonal antibody also conferred protection, indicating that it is TNF which is critical for initiating toxic shock symptoms. Taken together, this study defines basic differences between endotoxin (LPS)- and exotoxin (SEB)-mediated lethal shock, in that the former is mediated by macrophages and the latter by T cells. Yet the pathogenesis distal to the lymphokine/cytokine-producing cells appears surprisingly similar in that TNF represents a key mediator in inducing shock. PMID:1730929

  10. Microemulsion-made gadolinium carbonate hollow nanospheres showing magnetothermal heating and drug release.

    PubMed

    Jung-König, J; Sanhaji, M; Popescu, R; Seidl, C; Zittel, E; Schepers, U; Gerthsen, D; Hilger, I; Feldmann, C

    2017-06-22

    Gadolinium carbonate (Gd2(CO3)3) hollow nanospheres and their suitability for drug transport and magnetothermally-induced drug release are presented. The hollow nanospheres are prepared via a microemulsion-based synthesis using tris(tetramethylcyclopentadienyl)gadolinium(iii) and CO2 as the starting materials. Size, structure and composition of the as-prepared Gd2(CO3)3 hollow nanospheres are comprehensively validated by several independent analytical methods (HRTEM, HAADF-STEM, DLS, EDXS, XRD, FT-IR, DTA-TG). Accordingly, they exhibit an outer diameter of 26 ± 4 nm, an inner cavity of 7 ± 2 nm, and a wall thickness of 9 ± 3 nm. As a conceptual study, the nanocontainer-functionality of the Gd2(CO3)3 hollow nanospheres is validated upon filling with the anti-cancerogenic agent doxorubicin (DOX), which is straightforward via the microemulsion (ME) strategy. The resulting DOX@Gd2(CO3)3 nanocontainers provide the option of multimodal imaging including optical and magnetic resonance imaging (OI, MRI) as well as magnetothermal heating and drug release. As a proof-of-concept, we could already prove the intrinsic DOX-based fluorescence, a low systemic toxicity according to in vitro studies as well as the magnetothermal effect and a magnetothermally-induced DOX release. In particular, the latter is new for Gd-containing nanoparticles and highly promising in view of theranostic nanocontainers and synergistic physical and chemical tumor treatment.

  11. Latent Heat Release and Mass Loss in Baroclinic Waves on Early Mars

    NASA Astrophysics Data System (ADS)

    Sabato, J. S.; Pierrehumbert, R. T.

    2002-12-01

    Interpretation of ancient fluvial features on the surface of Mars requires a better understanding of the Early Mars climate, and baroclinic eddies (or "storms") would be a key feature of the midlatitude atmosphere. Such eddies would affect the climate by transporting heat, transporting CO2, stimulating CO2 precipitation, and modulating cloud formation. We present some preliminary results on baroclinic instability in a hypothetical dense CO2 Early Mars atmosphere, focusing on the novel features arising from this situation. These features include the latent heat release in a deep condensing layer (making for a particularly extreme form of moist baroclinic instability), and pressure alterations due to significant loss of mass in precipitating system. The stability of zonal flows in a two dimensional (x-z) quasigeostrophic model is examined. The model assumes a saturated "cloud" layer above about 2 scale heights (28 km). The zonal mean zonal wind is jet-like in the vertical with the profile /line{u}=αze-(z)/(H). The zonal mean temperature at the surface is constant (280K) and decays adiabatically with height until the saturation pressure is reached. In the condensing layer, the basic state temperature is given by the moist adiabat, Ts=(-a)/(b-ln (p/po). Normal mode calculations are performed in the absence of condensation. Initial value calculations are also performed in which the effect of latent heat release and mass loss accompanying condensation is included. Growth rates for both the normal mode and initial value problem are found as a function of the zonal scale (wavenumber). Various eddy characteristics are discussed.

  12. Release of H and He from TiC, stainless steel and graphite by pulsed electron and furnace heating

    SciTech Connect

    Picraux, S.T.; Wampler, W.R.

    1980-01-01

    The release of implanted D and /sup 3/He from TiC coatings, SS 304 and graphite by pulsed electron beam (e-beam) heating and furnace heating has been investigated. Low fluence implants of D or /sup 3/He and saturation fluence D implants have been studied for 0.5 - 1.5 keV D and 3 keV /sup 3/He. The retained D or /sup 3/He was monitored by ion beam analysis. The 50 ns e-beam pulsing resulted in the release of D in all materials and was compared with release during isochronal annealing in a furnace. A substantial enhancement in the fractional D release was found for D saturated TiC (0.25 D to host atom ratio) compared with low fluence implants. In contrast no enhancement of D release was observed for D saturated graphite and SS 304 compared with low fluence implants. Release of /sup 3/He from TiC was also obtained by e-beam pulsed heating and this release was not affected by the presence of saturation concentrations of D. Comparison to furnace anneals and the calculated time evolution of the temperature profiles suggests a simple model for the D release based on diffusion-limited release in the case of pulsed e-beam treatments and trap-limited release in the case of furnace bulk heating. These processes are closely related to hydrogen recycle in tokamaks and have implications for T inventory control and He ash removal.

  13. Interaction of heat release and vortex breakdown during flame flashback driven by combustion induced vortex breakdown

    NASA Astrophysics Data System (ADS)

    Konle, Marco; Sattelmayer, Thomas

    2009-10-01

    The interaction of heat release by chemical reaction and the flow dominates flame transition in swirling flows caused by combustion induced vortex breakdown (CIVB). The simultaneous application of 1 kHz high-speed particle imaging velocimetry (PIV) for the analysis of the flow field and OH planar laser-induced fluorescence for the detection of the flame front is particularly useful for the improvement of the understanding of the observed fast CIVB driven flame propagation. For the first time, the combination of both techniques was successfully applied to confined swirling flows. In the study, the flow field characteristics of an aerodynamically stabilized burner system with CIVB are analyzed in great depth. The influence of geometric parameters of the swirl generator was investigated and conclusions concerning the proper burner design of vortex breakdown premix burners are drawn from the experimental results. In particular, the effect of the vortex core with respect to the stability of the swirl stabilized burner is analyzed. The contribution of combustion to vortex breakdown is shown comparing isothermal and reacting flows. The presented data reveals that at the onset of CIVB driven flame transition, the azimuthal vorticity leads to the formation of a closed recirculation bubble at the tip of the internal recirculation zone. Once this bubble propagates upstream, the flame is able to follow and propagate relative to the bulk flow velocity with a velocity far beyond the turbulent flame speed. The interaction of reaction and flow was observed for different volumetric heat releases. The experiments confirm the CIVB theory of the authors, which was initially developed on the basis of a CFD study alone. Both the volume expansion and the baroclinic torque have an effect on whether fast flame propagation occurs. Whereas the volume expansion caused by the heat release stabilizes the flow field and the reaction, the baroclinic torque stimulates flame transition. For

  14. Wet-season Dormancy Release in Seed Banks of a Tropical Leguminous Shrub is Determined by Wet Heat

    PubMed Central

    VAN KLINKEN, RIEKS D.; FLACK, LLOYD K.; PETTIT, WILLIAM

    2006-01-01

    • Background and Aims Hard-seeded (physical) dormancy is common among plants, yet mechanisms for dormancy release are poorly understood, especially in the tropics. The following questions are asked: (a) whether dormancy release in seed banks of the tropical shrub Parkinsonia aculeata (Caesalpiniaceae) is determined by wet heat (incubation under wet, warm to hot, conditions); and (b) whether its effect is modified by microclimate. • Methods A seed burial trial was conducted in the wet–dry tropics (northern Australia) to compare dormancy release across different habitats (open, artificial cover, ground cover and canopy cover), burial depths (0, 3 and 20 cm) and burial durations (2, 6 and 14 weeks). Results were compared with predictions using a laboratory-derived relationship between wet heat and dormancy release, and microclimate data collected during the trial. • Key Results Wet heat (defined as the soil temperature above which seeds were exposed to field capacity or higher for a cumulative total of 24 h) was 43·6 °C in the 0 cm open treatment, and decreased with increasing shade and depth to 29·5 °C at 20 cm under canopy cover. The dormancy release model showed that wet heat was a good predictor of the proportion of seeds remaining dormant. Furthermore, dormancy release was particularly sensitive to wet heat across the temperature range encountered across treatments. This resulted in a 16-fold difference in dormancy levels between open (<5 % of seeds still dormant) and covered (82 %) microhabitats. • Conclusions These results demonstrate that wet heat is the principal dormancy release mechanism for P. aculeata when conditions are hot and wet. They also highlight the potential importance of microclimate in driving the population dynamics of such species. PMID:16891334

  15. Wet-season dormancy release in seed banks of a tropical leguminous shrub is determined by wet heat.

    PubMed

    van Klinken, Rieks D; Flack, Lloyd K; Pettit, William

    2006-10-01

    Hard-seeded (physical) dormancy is common among plants, yet mechanisms for dormancy release are poorly understood, especially in the tropics. The following questions are asked: (a) whether dormancy release in seed banks of the tropical shrub Parkinsonia aculeata (Caesalpiniaceae) is determined by wet heat (incubation under wet, warm to hot, conditions); and (b) whether its effect is modified by microclimate. A seed burial trial was conducted in the wet-dry tropics (northern Australia) to compare dormancy release across different habitats (open, artificial cover, ground cover and canopy cover), burial depths (0, 3 and 20 cm) and burial durations (2, 6 and 14 weeks). Results were compared with predictions using a laboratory-derived relationship between wet heat and dormancy release, and microclimate data collected during the trial. Wet heat (defined as the soil temperature above which seeds were exposed to field capacity or higher for a cumulative total of 24 h) was 43.6 degrees C in the 0 cm open treatment, and decreased with increasing shade and depth to 29.5 degrees C at 20 cm under canopy cover. The dormancy release model showed that wet heat was a good predictor of the proportion of seeds remaining dormant. Furthermore, dormancy release was particularly sensitive to wet heat across the temperature range encountered across treatments. This resulted in a 16-fold difference in dormancy levels between open (<5 % of seeds still dormant) and covered (82 %) microhabitats. These results demonstrate that wet heat is the principal dormancy release mechanism for P. aculeata when conditions are hot and wet. They also highlight the potential importance of microclimate in driving the population dynamics of such species.

  16. 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.

  17. 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.

  18. Characterization of nonlinear heat release-acoustic interactions in gas turbine combustors

    NASA Astrophysics Data System (ADS)

    Bellows, Benjamin D.

    This thesis describes an experimental investigation of the flame transfer function between flow disturbances and heat release oscillations in lean, premixed combustors. This research effort was motivated by the fact that modern gas turbines, operating fuel lean to minimize exhaust emissions, are susceptible to self-excited combustion oscillations. These instabilities generally occur when the unsteady combustion process couples with the acoustic modes of the combustion chamber. The resultant flow and structural vibrations can substantially reduce hot section part life. As such, avoiding operating regimes where high dynamics occur often requires operating at lower power outputs and/or higher pollutant emissions than the turbine is otherwise capable. This work demonstrated nonlinearities in the chemiluminescence response at large amplitude velocity oscillations in a turbulent, swirling flame. It is observed that the nonlinear flame response can exhibit a variety of behaviors, both in the shape of the response curve and the forcing amplitude at which nonlinearity is first observed depending on the operating conditions of the combustor. The phase between the flow oscillations and heat release is also seen to have substantial amplitude dependence. In addition, the interactions between the fundamental frequency and the higher and subharmonics of the measured signals can significantly influence the flame as well as the frequency response of the system. The nonlinear flame dynamics are governed by different mechanisms in different frequency and flowrate regimes. Three mechanisms, vortex rollup, unsteady flame liftoff, and parametric instability, are identified to influence the nonlinear flame response in these combustors. Analysis of the results shows that the mechanisms responsible for nonlinearity m the flame response are influenced by the Strouhal number, the mean velocity at the combustor dump plane, and the ratio of the oscillating velocity amplitude to the laminar

  19. Tomographic reconstruction of heat release rate perturbations induced by helical modes in turbulent swirl flames

    NASA Astrophysics Data System (ADS)

    Moeck, Jonas P.; Bourgouin, Jean-François; Durox, Daniel; Schuller, Thierry; Candel, Sébastien

    2013-04-01

    Swirl flows with vortex breakdown are widely used in industrial combustion systems for flame stabilization. This type of flow is known to sustain a hydrodynamic instability with a rotating helical structure, one common manifestation of it being the precessing vortex core. The role of this unsteady flow mode in combustion is not well understood, and its interaction with combustion instabilities and flame stabilization remains unclear. It is therefore important to assess the structure of the perturbation in the flame that is induced by this helical mode. Based on principles of tomographic reconstruction, a method is presented to determine the 3-D distribution of the heat release rate perturbation associated with the helical mode. Since this flow instability is rotating, a phase-resolved sequence of projection images of light emitted from the flame is identical to the Radon transform of the light intensity distribution in the combustor volume and thus can be used for tomographic reconstruction. This is achieved with one stationary camera only, a vast reduction in experimental and hardware requirements compared to a multi-camera setup or camera repositioning, which is typically required for tomographic reconstruction. Different approaches to extract the coherent part of the oscillation from the images are discussed. Two novel tomographic reconstruction algorithms specifically tailored to the structure of the heat release rate perturbations related to the helical mode are derived. The reconstruction techniques are first applied to an artificial field to illustrate the accuracy. High-speed imaging data acquired in a turbulent swirl-stabilized combustor setup with strong helical mode oscillations are then used to reconstruct the 3-D structure of the associated perturbation in the flame.

  20. Different assay conditions for detecting the production and release of heat-labile and heat-stable toxins in enterotoxigenic Escherichia coli isolates.

    PubMed

    Rocha, Letícia B; Ozaki, Christiane Y; Horton, Denise S P Q; Menezes, Caroline A; Silva, Anderson; Fernandes, Irene; Magnoli, Fabio C; Vaz, Tania M I; Guth, Beatriz E C; Piazza, Roxane M F

    2013-12-02

    Enterotoxigenic Escherichia coli (ETEC) produce heat-labile (LT) and/or heat-stable enterotoxins (ST). Despite that, the mechanism of action of both toxins are well known, there is great controversy in the literature concerning the in vitro production and release of LT and, for ST, no major concerns have been discussed. Furthermore, the majority of published papers describe the use of only one or a few ETEC isolates to define the production and release of these toxins, which hinders the detection of ETEC by phenotypic approaches. Thus, the present study was undertaken to obtain a better understanding of ST and LT toxin production and release under laboratory conditions. Accordingly, a collection of 90 LT-, ST-, and ST/LT-producing ETEC isolates was used to determine a protocol for toxin production and release aimed at ETEC detection. For this, we used previously raised anti-LT antibodies and the anti-ST monoclonal and polyclonal antibodies described herein. The presence of bile salts and the use of certain antibiotics improved ETEC toxin production/release. Triton X-100, as chemical treatment, proved to be an alternative method for toxin release. Consequently, a common protocol that can increase the production and release of LT and ST toxins could facilitate and enhance the sensitivity of diagnostic tests for ETEC using the raised and described antibodies in the present work.

  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. Assessment of heat resistance of bacterial spores from food product isolates by fluorescence monitoring of dipicolinic acid release.

    PubMed

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

    2005-07-01

    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 degrees C, 120 degrees C, and 131 degrees C, respectively. The estimated Z values were 6.3 degrees C, 6.1 degrees C, and 9.7 degrees 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 degrees C, 121 degrees C, and 131 degrees 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.

  3. Effect of dry heating and ionic gum on the physicochemical and release properties of starch from Dioscorea.

    PubMed

    Vashisht, Deepika; Pandey, Anima; Hermenean, Anca; Yáñez-Gascón, Maria Josefa; Pérez-Sánchez, Horacio; Kumar, K Jayaram

    2017-02-01

    To meet the ever increasing industrial demand for excipients with desirable properties, modified starch is regarded as an alternative to it. With this in mind, the present study focuses on the modification of starches of Dioscorea from Jharkhand (India) using dry heat treatment with and without ionic gum. Modified starches were prepared using sodium alginate (1% w/w). Native and modified starches were subjected to heat treatment at 130°C for 2h and 4h. The effect of heating and ionic gum on the properties of Dioscorea starch was investigated. The amylose content, water holding capacity, micromeritic properties, swelling power, solubility and morphology of starches were evaluated. Dry heat treatment of starches without gum showed an increment in water-holding capacity after two-hours heating, but no such increment was found after four-hours heating. Oil binding capacity of starches modified with gum varied from 62% to 78%. Strongest effect of heat treatment occurred on the morphology of starches and thereby modified starches showed distorted surface morphology. Amylose content (21.09-21.89%) found to be decreased with the addition of gum which lead to decrease in paste clarity. Starches heated with gum at high-temperature resulted in restrict swelling and slight increase in solubility. Micromeritic properties of the modified starches showed the good flow properties. Further, the modified starches were investigated for in-vitro release studies and that the thermally modified derivatives can be a good prospect in slow release formulations.

  4. Selective release from cultured mammalian cells of heat-shock (stress) proteins that resemble glia-axon transfer proteins.

    PubMed

    Hightower, L E; Guidon, P T

    1989-02-01

    Cultured rat embryo cells were stimulated to rapidly release a small group of proteins that included several heat-shock proteins (hsp110, hsp71, hscp73) and nonmuscle actin. The extracellular proteins were analyzed by two-dimensional polyacrylamide gel electrophoresis. Heat-shocked cells released the same set of proteins as control cells with the addition of the stress-inducible hsp110 and hsp71. Release of these proteins was not blocked by either monensin or colchicine, inhibitors of the common secretory pathway. A small amount of the glucose-regulated protein grp78 was externalized by this pathway. The extracellular accumulation of these proteins was inhibited after they were synthesized in the presence of the lysine analogue aminoethyl cysteine. It is likely that the analogue-substituted proteins were misfolded and could not be released from cells, supporting our conclusion that a selective release mechanism is involved. Remarkably, actin and the squid heat-shock proteins homologous to rat hsp71 and hsp110 are also among a select group of proteins transferred from glial cells to the squid giant axon, where they have been implicated in neuronal stress responses (Tytell et al.: Brain Res., 363:161-164, 1986). Based in part on the similarities between these two sets of proteins, we hypothesized that these proteins were released from labile cortical regions of animal cells in response to perturbations of homeostasis in cells as evolutionarily distinct as cultured rat embryo cells and squid glial cells.

  5. Polymyxin B-Induced Release of Low-Molecular-Weight, Heat-Labile Enterotoxin from Escherichia coli

    PubMed Central

    Evans, Doyle J.; Evans, Dolores G.; Gorbach, Sherwood L.

    1974-01-01

    Polymyxin B-induced release of enterotoxin from Escherichia coli strain H-10407 was demonstrated. Incubation of E. coli cells derived from 6-h cultures with polymyxin caused the rapid release of enterotoxin with a molecular weight of approximately 20,000, as estimated by the gel filtration technique. The rapidity of the release of enterotoxin indicates that it probably resides in the periplasmic space of the cell. The low-molecular-weight enterotoxin possessed vascular permeability factor and diarrheagenic activities, both of which were found to be heat-labile. The permeability factor activity of this enterotoxin was neutralized by antisera prepared against crude E. coli enterotoxin, Vibrio cholerae enterotoxin (choleragen), and V. cholerae toxoid (choleragenoid), respectively. Supernatant fluids of 6-h E. coli cultures did not contain this molecular form of enterotoxin but did contain very high-molecular-weight, heat-labile enterotoxin. Incubation of cells derived from older (18 h) cultures with polymyxin caused the release of both low- (20,000) and high-molecular-weight forms of enterotoxin. We concluded that either the 20,000-dalton form of heat-labile enterotoxin is not released by E. coli under in vitro growth conditions or that enterotoxin released in this form is rapidly destroyed or inactivated. PMID:16558081

  6. 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

    2014-06-06

    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.

  7. Comparison of the Heat Release Rate from the Mass Loss Calorimeter to the Cone Calorimeter for Wood-based Materials

    Treesearch

    Laura E. Hasburgh; Robert H. White; Mark A. Dietenberger; Charles R. Boardman

    2015-01-01

    There is a growing demand for material properties to be used as inputs in fi re behavior models designed to address building fire safety. This comparative study evaluates using the mass loss calorimeter as an alternative to the cone calorimeter for obtaining heat release rates of wood-based materials. For this study, a modified mass loss calorimeter utilized an...

  8. Experimental study of the influence of varying ceiling height on the heat release rate of a pool fire

    NASA Astrophysics Data System (ADS)

    Liu, Jiahao; Wang, Jian; Richard, Yuen

    2017-05-01

    To investigate the influence of ceiling height on the combustion process of a pool fire whose flame impinges the ceiling, a sequence of pool fires with varying ceiling heights was performed using a scaled-down cone calorimeter. N-heptane and jet-A were employed as fuels to conducted the tests. Experimental findings reveal that with the decreasing ceiling height, the maximum and average heat release rates will initially increase due to the enhanced heat feedback, and then decrease as a result of the restriction of air entrainment caused by the extremely small ceiling height. In addition, the dimensionless ceiling height is found to have a linear relationship with the logarithm value of the dimensionless averaged heat release rate for the two given fuels with the similar slope of -2/3.

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

    PubMed

    Basiri, Ladan; Rajabzadeh, Ghadir; Bostan, Aram

    2017-04-15

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

  10. 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.

  11. Visualization of the heat release zone of highly turbulent premixed jet flames

    NASA Astrophysics Data System (ADS)

    Lv, Liang; Tan, Jianguo; Zhu, Jiajian

    2017-10-01

    Visualization of the heat release zone (HRZ) of highly turbulent flames is significantly important to understand the interaction between turbulence and chemical reactions, which is the foundation to design and optimize engines. Simultaneous measurements of OH and CH2O using planar laser-induced fluorescence (PLIF) were performed to characterize the HRZ. A well-designed piloted premixed jet burner was employed to generate four turbulent premixed CH4/air jet flames, with different jet Reynolds numbers (Rejet) ranging from 4900 to 39200. The HRZ was visualized by both the gradient of OH and the pixel-by-pixel product of OH and CH2O. It is shown that turbulence has an increasing effect on the spatial structure of the flame front with an increasing height above the jet exit for the premixed jet flames, which results in the broadening of the HRZ and the increase of the wrinkling. The HRZ remains thin as the Rejet increases, whereas the preheat zone is significantly broadened and thickened. This indicates that the smallest turbulent eddies can only be able to enter the flame front rather than the HRZ in the present flame conditions. The flame quenching is observed with Rejet = 39200, which may be due to the strong entrainment of the cold air from outside of the burned gas region.

  12. Density functional theory simulations of polyethylene: principal Hugoniot, specific heats, compression and release isentropes

    NASA Astrophysics Data System (ADS)

    Cochrane, K. R.; Desjarlais, M. P.; Mattsson, T. R.

    2011-06-01

    An accurate equation of state (EOS) for polyethylene is required in order to model high energy density experiments for CH2 densities above 1 g/cc, temperatures above 1 eV, and pressures above 1 Mbar. Density Functional Theory (DFT) based molecular dynamics has been established as a method capable of yielding high fidelity results for many materials at a wide range of pressures and temperatures and has recently been applied to complex polymers such as polyethylene. Using high density polyethylene as the reference state, we compute the principal Hugoniot to 350 GPa, compression isentrope, and several release isentropes from states on the principal Hugoniot. We also calculate the specific heat and the dissociation along the Hugoniot. Our simulation results are validated by comparing to experimental data and then used to construct a wide range EOS. Sandia National Laboratories is a multiprogram laboratory managed and operated by Sandia Corp., a subsidiary of Lockheed Martin Corp., for the U.S. Department of Energy's National Nuclear Security Administration under Contract No. DE-AC04-94AL85000.

  13. 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

    2015-12-07

    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

  14. 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

    2016-11-01

    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.

  15. 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.

  16. The first critical heat-flux density of kerosene in stepwise and steady-state releases of heat

    NASA Astrophysics Data System (ADS)

    Obukhov, D. S.

    2006-11-01

    Experimental results on determination of stationary and nonstationary first critical densities of heat fluxes for the TS-1 hydrocarbon fuel are presented. As a consequence of the investigations carried out in a wide range of subcoolings and pressures, it has been established that for kerosene, just as for water, hydrogen, and helium, the first nonstationary critical heat-flux density qcr.1n coincides with the stationary one qcr1.

  17. 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

  18. 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

  19. 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.

  20. Modeling of heat release in aqueous suspensions of solid-state nanoparticles under electromagnetic radio-frequency irradiation

    NASA Astrophysics Data System (ADS)

    Tamarov, Konstantin P.; Kanavin, Andrey P.; Timoshenko, Victor Y.; Kabashin, Andrei V.; Zavestovskaya, Irina N.

    2016-03-01

    We examine absorption of electromagnetic radio-frequency (RF) radiation in aqueous suspensions of semiconductor (silicon) and metal (gold) nanoparticles (NPs) and theoretically investigate the heat release in these systems. The absorption of RF radiation is considered in both bulk electrolyte and the region around the NPs. Simulations show a strong dependence of the heating rate on electrical conductivity of the electrolyte rather than on that of NPs properties. The obtained results indicate that NPs can act as sensitizers of the RF induced hyperthermia for biomedical applications.

  1. On numerical model of time-dependent processes in three-dimensional porous heat-releasing objects

    NASA Astrophysics Data System (ADS)

    Lutsenko, Nickolay A.

    2016-10-01

    The gas flows in the gravity field through porous objects with heat-releasing sources are investigated when the self-regulation of the flow rate of the gas passing through the porous object takes place. Such objects can appear after various natural or man-made disasters (like the exploded unit of the Chernobyl NPP). The mathematical model and the original numerical method, based on a combination of explicit and implicit finite difference schemes, are developed for investigating the time-dependent processes in 3D porous energy-releasing objects. The advantage of the numerical model is its ability to describe unsteady processes under both natural convection and forced filtration. The gas cooling of 3D porous objects with different distribution of heat sources is studied using computational experiment.

  2. Temperature and heat capacity of atomic clusters as estimated in terms of kinetic-energy release of atomic evaporation

    NASA Astrophysics Data System (ADS)

    Fujii, Mikiya; Takatsuka, Kazuo

    2007-11-01

    The temperature and heat capacity of isolated atomic clusters are studied in terms of an ab initio statistical theory of kinetic energy distribution by atomic evaporation. Two definitions of canonical temperature are examined and numerically compared: One is based on the most probable kinetic energy release (KER), whereas the other is determined with use of the entire distribution of the KER. The mutual relationship and their advantages are discussed.

  3. Neuronal serotonin release triggers the heat shock response in C. elegans in the absence of temperature increase.

    PubMed

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

    2015-01-19

    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. 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. 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. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. 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.

  5. 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.

  6. Coupling between hydrodynamics, acoustics, and heat release in a self-excited unstable combustor

    NASA Astrophysics Data System (ADS)

    Harvazinski, Matthew E.; Huang, Cheng; Sankaran, Venkateswaran; Feldman, Thomas W.; Anderson, William E.; Merkle, Charles L.; Talley, Douglas G.

    2015-04-01

    The unsteady gas dynamic field in a closed combustor is determined by the nonlinear interactions between chamber acoustics, hydrodynamics, and turbulent combustion that can energize these modes. These interactions are studied in detail using hybrid RANS/large eddy simulations (RANS = Reynolds Averaged Navier-Stokes) of a non-premixed, high-pressure laboratory combustor that produces self-excited longitudinal instabilities. The main variable in the study is the relative acoustic length between the combustion chamber and the tube that injects oxidizer into the combustor. Assuming a half-wave (closed-closed) combustion chamber, the tube lengths approximately correspond to quarter-, 3/8-, and half-wave resonators that serve to vary the phasing between the acoustic modes in the tube and the combustion chamber. The simulation correctly predicts the relatively stable behavior measured with the shortest tube and the very unstable behavior measured with the intermediate tube. Unstable behavior is also predicted for the longest tube, a case for which bifurcated stability behavior was measured in the experiment. In the first (stable) configuration, fuel flows into the combustor uninterrupted, and heat release is spatially continuous with a flame that remains attached to the back step. In the second (unstable) configuration, a cyclic process is apparent comprising a disruption in the fuel flow, subsequent detachment of the flame from the back step, and accumulation of fuel in the recirculation zone that ignites upon arrival of a compression wave reflected from the downstream boundary of the combustion chamber. The third case (mixed stable/unstable) shares features with both of the other cases. The major difference between the two cases predicted to be unstable is that, in the intermediate length tube, a pressure wave reflection inside the tube pushes unburnt fuel behind the back step radially outward, leading to a post-coupled reignition mechanism, while in the case of the

  7. 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

  8. Argon release systematics of hypogene and supergene alunite based on progressive heating experiments from 100 to 1000°C

    NASA Astrophysics Data System (ADS)

    Itaya, Tetsumaru; Arribas, Antonio, Jr.; Okada, Toshinori

    1996-11-01

    Few minerals have as many different geological applications for Ksbnd Ar or 39Ar/ 40Ar dating as alunite (KAl 3(SO 4) 2(OH) 6), but a basic understanding of the systematics of argon release from this mineral is lacking. Progressive heating experiments from 100-1000°C at 100°C intervals were conducted in this study to obtain argon release patterns from hypogene and supergene alunite. The samples analyzed were selected from well understood deposits and are representative of the principal natural environments of acid-sulfate generation and related advanced argillic alteration and alunite formation. For gas extraction and purification, a low-blank metallic extraction-purification system used for dating silicates was complemented with a quartz-Pyrex glass line that included an external resistance furnace. The resulting patterns of argon release vs. temperature are well defined and similar for all the samples. Quantitative release of radiogenic 40Ar occurs during the dehydroxylation reaction of alunite at temperatures >400 and <700°C, in association with the first phase transformation of alunite during thermal decomposition to alum and alumina. This observation applies to alunites of different origin, regardless of characteristics such as grain size, crystal habit, growth temperature, and nature or origin of alunite-formation fluids. It applies as well to alunite treated chemically to remove small amounts of contaminant phases, such as illite. Argon released at <300°C is dominated by atmospheric argon adsorbed on the mineral surfaces, and Ar released at >800°C is mainly derived from the extraction system. The results indicate that the retentivity of Ar in fine-grained supergene alunite is similar to that of coarsely crystalline hypogene alunite. The data support the reliability of K-Ar dating of hypogene and supergene alunite and provide practical information to conduct routine high precision analyses.

  9. Transcriptional Activation of a Constitutive Heterochromatic Domain of the Human Genome in Response to Heat ShockD⃞

    PubMed Central

    Rizzi, Nicoletta; Denegri, Marco; Chiodi, Ilaria; Corioni, Margherita; Valgardsdottir, Rut; Cobianchi, Fabio; Riva, Silvano; Biamonti, Giuseppe

    2004-01-01

    Heat shock triggers the assembly of nuclear stress bodies that contain heat shock factor 1 and a subset of RNA processing factors. These structures are formed on the pericentromeric heterochromatic regions of specific human chromosomes, among which chromosome 9. In this article we show that these heterochromatic domains are characterized by an epigenetic status typical of euchromatic regions. Similarly to transcriptionally competent portions of the genome, stress bodies are, in fact, enriched in acetylated histone H4. Acetylation peaks at 6 h of recovery from heat shock. Moreover, heterochromatin markers, such as HP1 and histone H3 methylated on lysine 9, are excluded from these nuclear districts. In addition, heat shock triggers the transient accumulation of RNA molecules, heterogeneous in size, containing the subclass of satellite III sequences found in the pericentromeric heterochromatin of chromosome 9. This is the first report of a transcriptional activation of a constitutive heterochromatic portion of the genome in response to stress stimuli. PMID:14617804

  10. 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.

  11. Custom-designed Laser-based Heating Apparatus for Triggered Release of Cisplatin from Thermosensitive Liposomes with Magnetic Resonance Image Guidance.

    PubMed

    Dou, Yannan N; Weersink, Robert A; Foltz, Warren D; Zheng, Jinzi; Chaudary, Naz; Jaffray, David A; Allen, Christine

    2015-12-13

    Liposomes have been employed as drug delivery systems to target solid tumors through exploitation of the enhanced permeability and retention (EPR) effect resulting in significant reductions in systemic toxicity. Nonetheless, insufficient release of encapsulated drug from liposomes has limited their clinical efficacy. Temperature-sensitive liposomes have been engineered to provide site-specific release of drug in order to overcome the problem of limited tumor drug bioavailability. Our lab has designed and developed a heat-activated thermosensitive liposome formulation of cisplatin (CDDP), known as HTLC, to provide triggered release of CDDP at solid tumors. Heat-activated delivery in vivo was achieved in murine models using a custom-built laser-based heating apparatus that provides a conformal heating pattern at the tumor site as confirmed by MR thermometry (MRT). A fiber optic temperature monitoring device was used to measure the temperature in real-time during the entire heating period with online adjustment of heat delivery by alternating the laser power. Drug delivery was optimized under magnetic resonance (MR) image guidance by co-encapsulation of an MR contrast agent (i.e., gadoteridol) along with CDDP into the thermosensitive liposomes as a means to validate the heating protocol and to assess tumor accumulation. The heating protocol consisted of a preheating period of 5 min prior to administration of HTLC and 20 min heating post-injection. This heating protocol resulted in effective release of the encapsulated agents with the highest MR signal change observed in the heated tumor in comparison to the unheated tumor and muscle. This study demonstrated the successful application of the laser-based heating apparatus for preclinical thermosensitive liposome development and the importance of MR-guided validation of the heating protocol for optimization of drug delivery.

  12. Maturation of Released Spores Is Necessary for Acquisition of Full Spore Heat Resistance during Bacillus subtilis Sporulation ▿

    PubMed Central

    Sanchez-Salas, Jose-Luis; Setlow, Barbara; Zhang, Pengfei; Li, Yong-qing; Setlow, Peter

    2011-01-01

    The first ∼10% of spores released from sporangia (early spores) during Bacillus subtilis sporulation were isolated, and their properties were compared to those of the total spores produced from the same culture. The early spores had significantly lower resistance to wet heat and hypochlorite than the total spores but identical resistance to dry heat and UV radiation. Early and total spores also had the same levels of core water, dipicolinic acid, and Ca and germinated similarly with several nutrient germinants. The wet heat resistance of the early spores could be increased to that of total spores if early spores were incubated in conditioned sporulation medium for ∼24 h at 37°C (maturation), and some hypochlorite resistance was also restored. The maturation of early spores took place in pH 8 buffer with Ca2+ but was blocked by EDTA; maturation was also seen with early spores of strains lacking the CotE protein or the coat-associated transglutaminase, both of which are needed for normal coat structure. Nonetheless, it appears to be most likely that it is changes in coat structure that are responsible for the increased resistance to wet heat and hypochlorite upon early spore maturation. PMID:21821751

  13. 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

  14. Small heat shock proteins can release light dependence of tobacco seed during germination.

    PubMed

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

    2015-03-01

    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.

  15. 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. Copyright © 2015 Elsevier Inc. All rights reserved.

  16. 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.

  17. Sickle cell vaso-occlusive crisis induces the release of circulating serum heat shock protein-70.

    PubMed

    Adewoye, Adeboye H; Klings, Elizabeth S; Farber, Harrison W; Palaima, Elizabeth; Bausero, Maria A; McMahon, Lillian; Odhiambo, Adam; Surinder, Safaya; Yoder, Mark; Steinberg, Martin H; Asea, Alexzander

    2005-03-01

    Inflammation may play an important role in the pathophysiology of sickle cell disease (SCD), and recent studies have identified the 70-kDa heat shock protein (Hsp70) as an important mediator of inflammatory responses. Here we demonstrate a significant increase in circulating serum Hsp70 level in SCD during vaso-occlusive crisis (VOC) as compared with baseline steady-state levels (P <0.05) and a significant increase in Hsp70 levels in SCD at baseline compared with normal controls (P <0.05). Taken together, these results indicate that circulating serum Hsp70 might be a marker for VOC in SCD.

  18. Sickle Cell Vaso-occlusive Crisis Induces the Release of Circulating Serum Heat Shock Protein-70

    PubMed Central

    Adewoye, Adeboye H.; Klings, Elizabeth S.; Farber, Harrison W.; Palaima, Elizabeth; Bausero, Maria A.; McMahon, Lillian; Odhiambo, Adam; Surinder, Safaya; Yoder, Mark; Steinberg, Martin H.; Asea, Alexzander

    2006-01-01

    Inflammation may play an important role in the pathophysiology of sickle cell disease (SCD), and recent studies have identified the 70-kDa heat shock protein (Hsp70) as an important mediator of inflammatory responses. Here we demonstrate a significant increase in circulating serum Hsp70 level in SCD during vaso-occlusive crisis (VOC) as compared with baseline steady-state levels (P < 0.05) and a significant increase in Hsp70 levels in SCD at baseline compared with normal controls (P < 0.05). Taken together, these results indicate that circulating serum Hsp70 might be a marker for VOC in SCD. PMID:15726596

  19. 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.

  20. Effect of ATP on the release of hsp 70 and hsp 40 from the nucleus in heat-shocked HeLa cells.

    PubMed

    Ohtsuka, K; Utsumi, K R; Kaneda, T; Hattori, H

    1993-12-01

    We have recently found a novel 40-kDa heat-shock protein (hsp 40) in mammalian and avian cells and reported that the N-terminal amino acid sequence of mammalian hsp 40 has homology with the bacterial DnaJ heat-shock protein. Also, hsp 40 has been shown to be translocated from the cytoplasm into the nuclei/nucleoli by heat shock and colocalized with hsc 70 (p73) in the nucleoli of exactly the same cells. We here investigated the effect of ATP on the release of hsp 70 (both constitutive p73 and inducible p72) and hsp 40 from the nuclei/nucleoli of heat-shocked HeLa cells which were permeabilized with Nonidet-P40 using immunofluorescence and immunoblotting. Hsp 70 in the nucleoli was released by the addition of ATP but not by ADP, GTP, nonhydrolyzable ATP, nor high salt buffer. In contrast, hsp 40 was not released from the nucleoli with any of these treatments or any combination of these treatments. Thus, hsp 40 might dissociate spontaneously from the nucleoli after hsp 70 has been released in an ATP-dependent manner. Using cell fractionation methods, we showed that while the majority of hsp 40 is localized in the cytoplasm, a small portion of it is located in the microsome fraction in non-heat-shocked control cells and in cells which recovered from heat shock.

  1. Non-quasi-geostrophic effects in baroclinic waves with latent heat release

    NASA Technical Reports Server (NTRS)

    Fichtl, G. H.; Tang, C.-M.

    1984-01-01

    A study is conducted for the non-quasi-geostrophic baroclinic wave effects in a saturated atmosphere whose vertical motion is subject to pseudo-adiabatic processes. With respect to the characteristics of energetics for the first-order solution, it is noted that, in the cases of both the dry mode and the first moist mode, the heat transport quantities due to the second-order eddy are small and opposite in sign to their respective transports. The non-quasi-geostrophic effects render the vertical motion field asymmetric in each of the regions involved and enter into the present treatment only as nonlinear terms. The moisture transport terms in the eddy-available potential energy equation is small by comparison to other individual terms in the cyclone scale motion's energetics calculation. This is consistent with the observational results of Smith (1980).

  2. Non-quasi-geostrophic effects in baroclinic waves with latent heat release

    NASA Technical Reports Server (NTRS)

    Fichtl, G. H.; Tang, C.-M.

    1984-01-01

    A study is conducted for the non-quasi-geostrophic baroclinic wave effects in a saturated atmosphere whose vertical motion is subject to pseudo-adiabatic processes. With respect to the characteristics of energetics for the first-order solution, it is noted that, in the cases of both the dry mode and the first moist mode, the heat transport quantities due to the second-order eddy are small and opposite in sign to their respective transports. The non-quasi-geostrophic effects render the vertical motion field asymmetric in each of the regions involved and enter into the present treatment only as nonlinear terms. The moisture transport terms in the eddy-available potential energy equation is small by comparison to other individual terms in the cyclone scale motion's energetics calculation. This is consistent with the observational results of Smith (1980).

  3. Integrated bioprocess for production of human proinsulin C-peptide via heat release of an intracellular heptameric fusion protein.

    PubMed

    Jonasson, P; Nygren, P A; Jörnvall, H; Johansson, B L; Wahren, J; Uhlén, M; Ståhl, S

    2000-01-21

    An integrated bioprocess has been developed suitable for production of recombinant peptides using a gene multimerization strategy and site-specific cleavage of the resulting gene product. The process has been used for production in E. coli of the human proinsulin C-peptide via a fusion protein BB-C7 containing seven copies of the 31-residues C-peptide monomer. The fusion protein BB-C7 was expressed at high level, 1.8 g l(-1), as a soluble gene product in the cytoplasm. A heat treatment procedure efficiently released the BB-C7 fusion protein into the culture medium. This step also served as an initial purification step by precipitating the majority of the host cell proteins, resulting in a 70% purity of the BB-C7 fusion protein. Following cationic polyelectrolyte precipitation of the nucleic acids and anion exchange chromatography, native C-peptide monomers were obtained by enzymatic cleavage at flanking arginine residues. The released C-peptide material was further purified by reversed-phase chromatography and size exclusion chromatography. The overall yield of native C-peptide at a purity exceeding 99% was 400 mg l(-1) culture, corresponding to an overall recovery of 56%. The suitability of this process also for the production of other recombinant proteins is discussed.

  4. Laser-Triggered Small Interfering RNA Releasing Gold Nanoshells against Heat Shock Protein for Sensitized Photothermal Therapy.

    PubMed

    Wang, Zhaohui; Li, Siwen; Zhang, Min; Ma, Yi; Liu, Yuxi; Gao, Weidong; Zhang, Jiaqi; Gu, Yueqing

    2017-02-01

    The resistance of cancer cells to photothermal therapy is closely related to the overexpression of heat shock proteins (HSPs), which are abnormally upregulated when cells are under lethal stresses. Common strategies that use small molecule inhibitors against HSPs to enhance hyperthermia effect lack spatial and temporal control of drug release, leading to unavoidable systemic toxicity. Herein, a versatile photothermal platform is developed which is composed of a hollow gold nanoshell core densely packed with small interfering RNAs against heat shock protein 70 (Hsp70). Upon near infrared light irradiation, the small interfering RNAs can detach from gold surface specifically and escape from endosomes for Hsp70 silencing. Meanwhile, the temperature increases for hyperthermia therapy due to the high photothermal efficiency of the nanoshells. Efficient downregulation of Hsp70 after light activation is achieved in vitro and in vivo. Ultimately, the light-controlled dual functional nanosystem, with the effects of Hsp70 silencing and temperature elevation, results in sensitized photothermal therapy in nude mice model under mild temperature. This strategy smartly combines the localized photothermal therapy with controlled Hsp70 silencing, and has great potential for clinical translation with a simple and easily controlled structure.

  5. Laser‐Triggered Small Interfering RNA Releasing Gold Nanoshells against Heat Shock Protein for Sensitized Photothermal Therapy

    PubMed Central

    Wang, Zhaohui; Li, Siwen; Zhang, Min; Ma, Yi; Liu, Yuxi; Gao, Weidong; Zhang, Jiaqi

    2016-01-01

    The resistance of cancer cells to photothermal therapy is closely related to the overexpression of heat shock proteins (HSPs), which are abnormally upregulated when cells are under lethal stresses. Common strategies that use small molecule inhibitors against HSPs to enhance hyperthermia effect lack spatial and temporal control of drug release, leading to unavoidable systemic toxicity. Herein, a versatile photothermal platform is developed which is composed of a hollow gold nanoshell core densely packed with small interfering RNAs against heat shock protein 70 (Hsp70). Upon near infrared light irradiation, the small interfering RNAs can detach from gold surface specifically and escape from endosomes for Hsp70 silencing. Meanwhile, the temperature increases for hyperthermia therapy due to the high photothermal efficiency of the nanoshells. Efficient downregulation of Hsp70 after light activation is achieved in vitro and in vivo. Ultimately, the light‐controlled dual functional nanosystem, with the effects of Hsp70 silencing and temperature elevation, results in sensitized photothermal therapy in nude mice model under mild temperature. This strategy smartly combines the localized photothermal therapy with controlled Hsp70 silencing, and has great potential for clinical translation with a simple and easily controlled structure. PMID:28251053

  6. Negative effect of heat shock on feline calicivirus release from infected cells is associated with the control of apoptosis.

    PubMed

    Alvarez-Sanchez, Cristal; Cancio-Lonches, Clotilde; Mora-Heredia, José Eduardo; Santos-Valencia, Juan Carlos; Barrera-Vázquez, Oscar Salvador; Yocupicio-Monroy, Martha; Gutiérrez-Escolano, Ana Lorena

    2015-02-16

    FCV infection causes rapid cytopathic effects, and its replication results in the induction of apoptosis changes in cultured cells. It is well established that the survival of apoptotic cells can be enhanced by the expression of heat-shock proteins (Hsp) to prevent damage or facilitate recovery. Hsps can act as molecular chaperones, but they can also have anti-apoptotic roles by binding to apoptotic proteins and inhibiting the activation of caspases, the primary mediators of apoptosis. Because apoptosis occurs during FCV infection and heat shock (HS) treatment has a cytoprotective role due to the expression of Hsps, we studied the effect of the HS response to hyperthermia during FCV infection in cultured cells. We found that FCV infection does not inhibit the expression of Hsp70 induced by HS and that non-structural and structural protein synthesis was not modified during HS treatment. However, HS caused a delay in the appearance of a cytopathic effect in infected cells, as well as a reduction in the extracellular but not in the cell-associated viral yield. This antiviral effect of HS correlates with the inhibition of caspase-3 activation. Thus, the HS-induced reduction in virus production appeared to be associated with the control of apoptosis, supporting previous data that indicate that apoptosis is necessary for FCV release. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. 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.

  8. Controlling Heat Release from a Close-Packed Bisazobenzene-Reduced-Graphene-Oxide Assembly Film for High-Energy Solid-State Photothermal Fuels.

    PubMed

    Zhao, Xiaoze; Feng, Yiyu; Qin, Chengqun; Yang, Weixiang; Si, Qianyu; Feng, Wei

    2017-04-10

    A closed-cycle system for light-harvesting, storage, and heat release is important for utilizing and managing renewable energy. However, combining a high-energy, stable photochromic material with a controllable trigger for solid-state heat release remains a great challenge for developing photothermal fuels (PTFs). This paper presents a uniform PTF film fabricated by the assembly of close-packed bisazobenzene (bisAzo) grafted onto reduced graphene oxide (rGO). The assembled rGO-bisAzo template exhibited a high energy density of 131 Wh kg(-1) and a long half-life of 37 days owing to inter- or intramolecular H-bonding and steric hindrance. The rGO-bisAzo PTF film released and accumulated heat to realize a maximum temperature difference (DT) of 15 °C and a DT of over 10 °C for 30 min when the temperature difference of the environment was greater than100 °C. Controlling heat release in the solid-state assembly paves the way to develop highly efficient and high-energy PTFs for a multitude of applications.

  9. 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.

  10. 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.

  11. Heat shock response and homeostatic plasticity

    PubMed Central

    Karunanithi, Shanker; Brown, Ian R.

    2015-01-01

    Heat shock response and homeostatic plasticity are mechanisms that afford functional stability to cells in the face of stress. Each mechanism has been investigated independently, but the link between the two has not been extensively explored. We explore this link. The heat shock response enables cells to adapt to stresses such as high temperature, metabolic stress and reduced oxygen levels. This mechanism results from the production of heat shock proteins (HSPs) which maintain normal cellular functions by counteracting the misfolding of cellular proteins. Homeostatic plasticity enables neurons and their target cells to maintain their activity levels around their respective set points in the face of stress or disturbances. This mechanism results from the recruitment of adaptations at synaptic inputs, or at voltage-gated ion channels. In this perspective, we argue that heat shock triggers homeostatic plasticity through the production of HSPs. We also suggest that homeostatic plasticity is a form of neuroprotection. PMID:25814928

  12. Engine Operating Conditions and Fuel Properties on Pre-Spark Heat Release and SPI Promotion in SI Engines

    SciTech Connect

    Splitter, Derek A; Kaul, Brian C; Szybist, James P; Jatana, Gurneesh S

    2017-01-01

    This work explores the dependence of fuel ignition delay on stochastic pre-ignition (SPI). Findings are based on bulk gas thermodynamic state, where the effects of kinetically controlled bulk gas pre-spark heat release (PSHR) are correlated to SPI tendency and magnitude. Specifically, residual gas and low temperature PSHR chemistry effects and observations are explored, which are found to be indicative of bulk gas conditions required for strong SPI events. Analyzed events range from non-knocking SPI to knocking SPI and even detonation SPI events in excess of 325 bar peak cylinder pressure. The work illustrates that singular SPI event count and magnitude are found to be proportional to PSHR of the bulk gas mixture and residual gas fraction. Cycle-to-cycle variability in trapped residual mass and temperature are found to impose variability in singular SPI event count and magnitude. However, clusters and short lived bursts of multiple SPI events are found to better correlate with fuel-wall interaction. The results highlight the interplay of bulk gas thermodynamics and SPI ignition source, on SPI event magnitude and cluster tendency. Moreover, the results highlight fundamental fuel reactivity and associated hypersensitivity to operating conditions at SPI prone operating conditions.

  13. 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.

  14. 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

  15. 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

  16. Effect of radiative transfer of heat released from combustion reaction on temperature distribution: A numerical study for a 2-D system

    NASA Astrophysics Data System (ADS)

    Zhou, Huai-Chun; Ai, Yu-Hua

    2006-09-01

    Both light and heat are produced during a chemical reaction in a combustion process, but traditionally all the energy released is taken as to be transformed into the internal energy of the combustion medium. So the temperature of the medium increases, and then the thermal radiation emitted from it increases too. Chemiluminescence is generated during a chemical reaction and independent of the temperature, and has been used widely for combustion diagnostics. It was assumed in this paper that the total energy released in a combustion reaction is divided into two parts, one part is a self-absorbed heat, and the other is a directly emitted heat. The former is absorbed immediately by the products, becomes the internal energy and then increases the temperature of the products as treated in the traditional way. The latter is emitted directly as radiation into the combustion domain and should be included in the radiation transfer equation (RTE) as a part of radiation source. For a simple, 2-D, gray, emitting absorbing, rectangular system, the numerical study showed that the temperatures in reaction zones depended on the fraction of the directly emitted energy, and the smaller the gas absorption coefficient was, the more strong the dependence appeared. Because the effect of the fraction of the directly emitted heat on the temperature distribution in the reacting zones for gas combustion is significant, it is required to conduct experimental measurements to determine the fraction of self-absorbed heat for different combustion processes.

  17. 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.

  18. 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.

  19. 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.

  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. Additional information is included in the original extended abstract.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. Heat shock induces apoptosis through reactive oxygen species involving mitochondrial and death receptor pathways in corneal cells.

    PubMed

    Hsu, Ya-Ling; Yu, Hsin-Su; Lin, Hsien-Chung; Wu, Kwou-Yeung; Yang, Rei-Cheng; Kuo, Po-Lin

    2011-10-01

    Although many studies have been performed to elucidate the molecular consequences of ultraviolet irradiation, little is known about the effect of infrared radiation on ocular disease. In addition to photons, heat is generated as a consequence of infrared irradiation, and heat shock is widely considered to be an environmental stressor. Here, we are the first to investigate the biological effect of heat shock on Statens Seruminstitut Rabbit Cornea (SIRC) cells. Our results indicate that heat shock exhibits effective cell proliferation inhibition by inducing apoptosis. Heat shock triggers the mitochondrial apoptotic pathway indicated by a change in Bax/Bcl-2 ratios, resulting in caspase-9 activity. In addition, heat shock triggered the death receptor apoptotic pathway indicated by a change in Fas ligand expression, resulting in caspase-8 activity. Furthermore, we also found that generation of reactive oxygen species (ROS) is a critical mediator in heat shock-induced apoptosis. In addition, the antioxidant vitamin C significantly decreased heat shock-mediated apoptosis. Taken together, these findings suggest a critical role for ROS involving mitochondrial and death receptor pathways in heat shock-mediated apoptosis of cornea cells. Copyright © 2011 Elsevier Ltd. All rights reserved.

  8. Bacterial lipopolysaccharide augments febrile-range hyperthermia-induced heat shock protein 70 expression and extracellular release in human THP1 cells.

    PubMed

    Tulapurkar, Mohan E; Ramarathnam, Aparna; Hasday, Jeffrey D; Singh, Ishwar S

    2015-01-01

    Sepsis, a devastating and often lethal complication of severe infection, is characterized by fever and dysregulated inflammation. While infections activate the inflammatory response in part through Toll-like receptors (TLRs), fever can partially activate the heat shock response with generation of heat shock proteins (HSPs). Since extracellular HSPs, especially HSP70 (eHSP70), are proinflammatory TLR agonists, we investigated how exposure to the TLR4 agonist, bacterial lipopolysaccharide (LPS) and febrile range hyperthermia (FRH; 39.5°C) modify HSP70 expression and extracellular release. Using differentiated THP1 cells, we found that concurrent exposure to FRH and LPS as well as TLR2 and TLR3 agonists synergized to activate expression of inducible HSP72 (HSPA1A) mRNA and protein via a p38 MAP kinase-requiring mechanism. Treatment with LPS for 6 h stimulated eHSP70 release; levels of eHSP70 released at 39.5°C were higher than at 37°C roughly paralleling the increase in intracellular HSP72 in the 39.5°C cells. By contrast, 6 h exposure to FRH in the absence of LPS failed to promote eHSP70 release. Release of eHSP70 by LPS-treated THP1 cells was inhibited by glibenclamide, but not brefeldin, indicating that eHSP70 secretion occurred via a non-classical protein secretory mechanism. Analysis of eHSP70 levels in exosomes and exosome-depleted culture supernatants from LPS-treated THP1 cells using ELISA demonstrated similar eHSP70 levels in unfractionated and exosome-depleted culture supernatants, indicating that LPS-stimulated eHSP70 release did not occur via the exosome pathway. Immunoblot analysis of the exosome fraction of culture supernatants from these cells showed constitutive HSC70 (HSPA8) to be the predominant HSP70 family member present in exosomes. In summary, we have shown that LPS stimulates macrophages to secrete inducible HSP72 via a non-classical non-exosomal pathway while synergizing with FRH exposure to increase both intracellular and secreted levels

  9. Impact of Trench and Ramp Film Cooling Designs to Reduce Heat Release Effects in a Reacting Flow

    DTIC Science & Technology

    2012-03-22

    turbine blade shown in Figure I-3 demonstrates conventional thin film cooling used in high temperature turbines . The cooling air enters through the base...high temperature gas near the blade surface reducing the local gas temperature. Additional heat transfers to the cooling air as it travels though...the center of the blade and exits through the surface. As a result, the material surface temperature is reduced allowing for Turbine Inlet

  10. 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

  11. A hyposensitive anticancer drug induces higher surface expression and release of heat shock proteins in a human hepatocellular carcinoma cell line.

    PubMed

    Yang, Mei; Xu, Zhe; Wang, Qi; Zhang, An-Qin; Min, Jun

    2015-08-01

    Heat shock proteins (HSPs) respond to multiple stresses and have been implicated as essential immune chaperones that regulate innate and adaptive immunity. The exposure of HSPs containing tumour peptide complex to immune surveillance elements may elicit a specific anti-tumour response. The present study examined the potential of anticancer drugs to induce apoptosis of HepG2 cells and elicit the expression of HSP proteins, including HSP70 and gp96, on the membrane or their release to the extracellular environment, leading to HSP exposure. In the present study, etoposide and carboplatin were classified by an adenosine triphosphate assay as representatives of hypersensitive and hyposensitive anticancer drugs, respectively. Flow cytometry, immunofluorescence, ELIZA and reverse transcription quantitative polymerase chain reaction were all used to detect changes in the HSPs. The results demonstrated that etoposide and carboplatin induced apoptosis of HepG2 cells. In addition, following treatment with etoposide or carboplatin, HSP70/gp96 expression increased, demonstrating a 'transfer expression' pattern: The cytosol expression decreased while the surface expression increased. These alterations progressed steadily with notable alterations following treatment with etoposide for 24 h or carboplatin for 72 h. Additionally, at the end of treatment, release of HSP70/gp96 to the extracellular environment increased. Notably, following treatment with the hyposensitive anticancer drug carboplatin for 72 h, the surface expression of gp96 in HepG2 cells was significantly increased. These results suggest that when combined with cancer cell apoptosis, anticancer drugs induce the membrane expression and release of HSP70/gp96 in hepatocellular carcinoma (HCC) cells, which may represent a crucial event in the immune anti-tumour response. Notably, treatment with the hyposensitive anticancer drug for a longer time period resulted in greater surface expression and release of gp96, which

  12. 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.

  13. Quarterly technical progress report No. 2, December 20-March 19, 1982. Second quarterly report on the effect of rapid heating rate on coal nitrogen and sulfur release

    SciTech Connect

    Gat, N.

    1982-04-26

    A laser pyrolysis technique is applied to the investigation of the effects of heating rate on release of coal-bound sulfur and nitrogen. An experimental system characterization and calibration has been completed. A detailed documentation was prepared describing the 3-color pyrometer and the data analysis technique. The coal particle feed system has been calibrated to provide accurate mass flow rate at pre-selected particle velocities. The first batch of samples submitted for chemical analysis will be used for the determination of kinetics parameters at a high heating rate (approximately equal to 10/sup 6/ K/s). The coal used presently is a Montana Rosebud. Two other coals are available; one is ILL No. 6 (through EERC) which will need to be pulverized and the second is a Pitt. hv-A (through KVB). It was confirmed that sieve and drag size distribution of coal differ significantly, and that particle shape effects may be significant in the modelling of particle dynamics.

  14. 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

  15. The Effect of Ethanol Addition to Gasoline on Low- and Intermediate-Temperature Heat Release under Boosted Conditions in Kinetically Controlled Engines

    NASA Astrophysics Data System (ADS)

    Vuilleumier, David Malcolm

    The detailed study of chemical kinetics in engines has become required to further advance engine efficiency while simultaneously lowering engine emissions. This push for higher efficiency engines is not caused by a lack of oil, but by efforts to reduce anthropogenic carbon dioxide emissions, that cause global warming. To operate in more efficient manners while reducing traditional pollutant emissions, modern internal combustion piston engines are forced to operate in regimes in which combustion is no longer fully transport limited, and instead is at least partially governed by chemical kinetics of combusting mixtures. Kinetically-controlled combustion allows the operation of piston engines at high compression ratios, with partially-premixed dilute charges; these operating conditions simultaneously provide high thermodynamic efficiency and low pollutant formation. The investigations presented in this dissertation study the effect of ethanol addition on the low-temperature chemistry of gasoline type fuels in engines. These investigations are carried out both in a simplified, fundamental engine experiment, named Homogeneous Charge Compression Ignition, as well as in more applied engine systems, named Gasoline Compression Ignition engines and Partial Fuel Stratification engines. These experimental investigations, and the accompanying modeling work, show that ethanol is an effective scavenger of radicals at low temperatures, and this inhibits the low temperature pathways of gasoline oxidation. Further, the investigations measure the sensitivity of gasoline auto-ignition to system pressure at conditions that are relevant to modern engines. It is shown that at pressures above 40 bar and temperatures below 850 Kelvin, gasoline begins to exhibit Low-Temperature Heat Release. However, the addition of 20% ethanol raises the pressure requirement to 60 bar, while the temperature requirement remains unchanged. These findings have major implications for a range of modern engines

  16. Anticancer drugs cause release of exosomes with heat shock proteins from human hepatocellular carcinoma cells that elicit effective natural killer cell antitumor responses in vitro.

    PubMed

    Lv, Li-Hong; Wan, Yun-Le; Lin, Yan; Zhang, Wei; Yang, Mei; Li, Guo-Lin; Lin, Hao-Ming; Shang, Chang-Zhen; Chen, Ya-Jin; Min, Jun

    2012-05-04

    Failure of immune surveillance related to inadequate host antitumor immune responses has been suggested as a possible cause of the high incidence of recurrence and poor overall survival outcome of hepatocellular carcinoma. The stress-induced heat shock proteins (HSPs) are known to act as endogenous "danger signals" that can improve tumor immunogenicity and induce natural killer (NK) cell responses. Exosome is a novel secretory pathway for HSPs. In our experiments, the immune regulatory effect of the HSP-bearing exosomes secreted by human hepatocellular carcinoma cells under stress conditions on NK cells was studied. ELISA results showed that the production of HSP60, HSP70, and HSP90 was up-regulated in both cell lines in a stress-specific manner. After exposure to hepatocellular carcinoma cell-resistant or sensitive anticancer drugs (hereafter referred to as "resistant" or "sensitive" anticancer drug), the membrane microvesicles were actively released by hepatocellular carcinoma cells, differing in their ability to present HSPs on the cell surface, which were characterized as exosomes. Acting as a decoy, the HSP-bearing exosomes efficiently stimulated NK cell cytotoxicity and granzyme B production, up-regulated the expression of inhibitory receptor CD94, and down-regulated the expression of activating receptors CD69, NKG2D, and NKp44. Notably, resistant anticancer drugs enhanced exosome release and generated more exosome-carried HSPs, which augmented the activation of the cytotoxic response. In summary, our findings demonstrated that exosomes derived from resistant anticancer drug-treated HepG2 cells conferred superior immunogenicity in inducing HSP-specific NK cell responses, which provided a clue for finding an efficient vaccine for hepatocellular carcinoma immunotherapy.

  17. Enhanced intracellular heat shock protein 70 expression of leukocytes and serum interleukins release: comparison of on-pump and off-pump coronary artery surgery.

    PubMed

    Lin, Chih-Yuan; Yang, Tung-Lin; Hong, Gou-Jieng; Li, Chi-Yuan; Lin, Feng-Yen; Tsai, Chien-Sung

    2010-04-01

    Coronary artery bypass grafting (CABG) employing cardiopulmonary bypass (CPB; "on-pump" technique) is known to induce a systemic inflammatory response and heat-shock protein 70 kDa (HSP70) expression. The objective of the present study was to investigate the perioperative intracellular HSP70 expression of leukocytes and serum interleukin (IL) release in CABG conducted with both on-pump and off-pump techniques. Thirty-seven patients referred for elective CABG were enrolled in this study. These patients were categorized into the following three groups: on-pump cardioplegic arrest (n = 12); on-pump beating heart (n = 13); and off-pump (n = 12). Blood samples were collected at four time points during the perioperative period. Enzyme-linked immunosorbent assay (ELISA) was used to determine the serum level of IL-8, IL-10, IL-12, and HSP70. Flow cytometric analysis of intracellular HSP70 was performed in populations of lymphocytes, monocytes, and granulocytes. The clinical outcomes were comparable among the three groups. Elevated serum IL-8, IL-10, IL-12 were found in all three groups during the perioperative period. Serum HSP70 was elevated in all three groups and was significantly lower in the off-pump group than in the on-pump cardioplegic arrest and on-pump beating-heart groups. Heat shock protein-70 expression was found in leukocytes and showed a faster response in monocytes and granulocytes than in lymphocytes. The inflammatory response in the off-pump group was less than in either of the on-pump groups. During the perioperative period, activation of inflammatory response was associated with enhanced expression of HSP70 within leukocytes in CABG patients.

  18. 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.

  19. An evaluation of the assumed beta probability density function subgrid-scale model for large eddy simulation of nonpremixed, turbulent combustion with heat release

    SciTech Connect

    Wall, Clifton; Boersma, Bendiks Jan; Moin, Parviz

    2000-10-01

    The assumed beta distribution model for the subgrid-scale probability density function (PDF) of the mixture fraction in large eddy simulation of nonpremixed, turbulent combustion is tested, a priori, for a reacting jet having significant heat release (density ratio of 5). The assumed beta distribution is tested as a model for both the subgrid-scale PDF and the subgrid-scale Favre PDF of the mixture fraction. The beta model is successful in approximating both types of PDF but is slightly more accurate in approximating the normal (non-Favre) PDF. To estimate the subgrid-scale variance of mixture fraction, which is required by the beta model, both a scale similarity model and a dynamic model are used. Predictions using the dynamic model are found to be more accurate. The beta model is used to predict the filtered value of a function chosen to resemble the reaction rate. When no model is used, errors in the predicted value are of the same order as the actual value. The beta model is found to reduce this error by about a factor of two, providing a significant improvement. (c) 2000 American Institute of Physics.

  20. The influence of fuel injection and heat release on bulk flow structures in a direct-injection, swirl-supported diesel engine

    NASA Astrophysics Data System (ADS)

    Sterl, Andreas; van Oldenborgh, Geert Jan; Hazeleger, Wilco; Burgers, Gerrit

    2007-08-01

    Particle image velocimetry is applied to measure the vertical (r z) plane flow structures in a light-duty direct-injection diesel engine with a realistic piston geometry. The measurements are corrected for optical distortions due to the curved piston bowl walls and the cylindrical liner. Mean flow fields are presented and contrasted for operation both with and without fuel injection and combustion. For operation with combustion, the two-dimensional divergence of the measured mean velocity fields is employed as a qualitative indicator of the locations of mean heat release. In agreement with numerical simulations, dual-vortex, vertical plane mean flow structures that may enhance mixing rates are formed approximately mid-way through the combustion event. Late in the cycle a toroidal vortex forms outside the bowl mouth. Imaging studies suggest that soot and partially oxidized fuel trapped within this vortex are slow to mix with surrounding fluid; moreover, the vortex impedes mixing of fluid exiting the bowl with air within the squish volume.

  1. 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

  2. An in vitro model to consider the effect of 2 mM glutamine and KNK437 on endotoxin-stimulated release of heat shock protein 70 and inflammatory mediators.

    PubMed

    Marino, Luise V; Pathan, Nazima; Meyer, Rosan W; Wright, Victoria J; Habibi, Parviz

    2016-03-01

    Glutamine has been shown to promote the release of heat shock protein 70 (HSP70) both within experimental in vitro models of sepsis and in adults with septic shock. This study aimed to investigate the effects of 2 mM glutamine and an inhibitor of HSP70 (KNK437) on the release of HSP70 and inflammatory mediators in healthy adult volunteers. An in vitro whole blood endotoxin stimulation assay was used. The addition of 2 mM glutamine significantly increased HSP70 levels over time (P < 0.05). HSP70 release had a positive correlation at 4 h with IL-1 β (r = 0.51, P = 0.03) and an inverse correlation with TNF-α (r = -0.56, P = 0.02) and IL-8 levels (r = -0.52, P = 0.03), and there were no significant correlations between HSP70 and IL6 or IL-10 or glutamine. Glutamine supplementation significantly (P < 0.05) attenuated the release of IL-10 at 4 h and IL-8 at 24 h, compared with conditions without glutamine. In endotoxin-stimulated blood there were no significant differences in the release of IL-6, TNF-α, and IL-1 β with glutamine supplementation at 4 and 24 h. However, glutamine supplementation (2 mM) appeared to attenuate the release of inflammatory mediators (IL-1 β, IL-6, TNF-α), although this effect was not statistically significant. The addition of KNK437, a HSP70 inhibitor, significantly diminished HSP70 release, which resulted in lower levels of inflammatory mediators (P < 0.05). Glutamine supplementation promotes HSP70 release in an experimental model of sepsis. After the addition of KNK437, the effects of glutamine on HSP70 and inflammatory mediator release appear to be lost, suggesting that HSP70 in part orchestrates the inflammatory mediator response to sepsis. The clinical implications require further investigation. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. 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 PAGES

    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

  4. Technical note: physiological response of beef heifers after receiving a reused controlled internal drug release insert processed with different heat-treating methods.

    PubMed

    Dahlen, C R; Klein, S I; Lamb, G C; Mercadante, V R G; Steichen, P L

    2014-05-01

    Eighty-one prepubertal beef heifers were used to evaluate effects of used controlled internal drug release (CIDR) insert heating methods on concentrations of progesterone after CIDR insert reinsertion. Heifers were stratified by weight and birth date and then assigned to receive a new CIDR insert (New; n = 10) or 1 of 8 used (7 d prior use) CIDR insert treatments: 1) no processing (Used; n = 10), 2) autoclaved (Autoclaved; n = 8), 3) processed in dishwasher (Dishwasher; n = 8), 4) processed in microwave for 30 s (Microwave; n = 10), 5) processed in toaster oven (Oven; n = 9), 6) processed in clothes dryer (Dryer; n = 10), 7) processed in boiling water (Boiled; n = 8), or 8) stored outdoors for 60 d (Outside; n = 8). Used CIDR inserts were processed at 121°C for 30 min for autoclaved and oven treatments, at 121°C for boiled treatment, and for 30 min for dryer and dishwasher treatments. Blood samples were collected on d -10, immediately before CIDR insert insertion (d 0), 3 h after CIDR insert insertion (3 h), daily while CIDR insert was in place (d 1 to 11), and 24 h after CIDR insert removal (d 12) for analysis of concentrations of progesterone. Subjective color scores (1 = bright white to 5 = completely stained yellow/red) were assigned to each CIDR insert after d 11. A treatment × time interaction (P < 0.0001) was present for concentrations of progesterone. Concentrations of progesterone were similar (P > 0.10) for heifers receiving a used CIDR insert compared with heifers receiving CIDR inserts processed in a dishwasher, microwave, oven, dryer, or boiling water (collectively reported as "Processed"). However, heifers receiving autoclaved CIDR inserts had greater (P < 0.05) concentrations of progesterone from h 3 to d 3 but similar (P > 0.10) concentrations of progesterone from d 4 to d 11 compared with heifers receiving used or processed CIDR inserts. From d 1 to 11 heifers receiving outside CIDR inserts had decreased (P < 0.05) concentrations of progesterone

  5. 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.

  6. Omnigen-AF reduces basal plasma cortisol, AWA cortisol release to adrencocorticotropic hormone or corticotrophin releasing hormone & vasopressin in lactating dairy cows under thermoneutral or acute heat stress conditions.

    USDA-ARS?s Scientific Manuscript database

    Differences in the adrenal cortisol response of OmniGen-AF (OG) supplemented dairy cows to a corticotrophin releasing hormone (CRH) and vasopressin (VP) or an adrenocorticotropic hormone (ACTH) challenge when housed at different temperature-humidity indices (THI) were studied. Holstein cows (n=12; 1...

  7. Vertical Profiles of Latent Heat Release and Their Retrieval for TOGA COARE Convective Systems Using a Cloud Resolving Model, SSM/I, and Ship-borne Radar Data

    NASA Technical Reports Server (NTRS)

    Tao, Wei-Kuo; Lang, S.; Simpson, J.; Olson, W. S.; Johnson, D.; Ferrier, B.; Kummerow, C.; Adler, R.

    1999-01-01

    Latent heating profiles associated with three (TOGA COARE) Tropical Ocean and Global Atmosphere Coupled Ocean Atmosphere Response Experiment active convective episodes (December 10-17 1992; December 19-27 1992; and February 9-13 1993) are examined using the Goddard Cumulus Ensemble (GCE) Model and retrieved by using the Goddard Convective and Stratiform Heating (CSH) algorithm . The following sources of rainfall information are input into the CSH algorithm: Special Sensor Microwave Imager (SSM/1), Radar and the GCE model. Diagnostically determined latent heating profiles calculated using 6 hourly soundings are used for validation. The GCE model simulated rainfall and latent heating profiles are in excellent agreement with those estimated by soundings. In addition, the typical convective and stratiform heating structures (or shapes) are well captured by the GCE model. Radar measured rainfall is smaller than that both estimated by the GCE model and SSM/I in all three different COARE IFA periods. SSM/I derived rainfall is more than the GCE model simulated for the December 19-27 and February 9-13 periods, but is in excellent agreement with the GCE model for the December 10-17 period. The GCE model estimated stratiform amount is about 50% for December 19-27, 42% for December 11-17 and 56% for the February 9-13 case. These results are consistent with large-scale analyses. The accurate estimates of stratiform amount is needed for good latent heating retrieval. A higher (lower) percentage of stratiform rain can imply a maximum heating rate at a higher (lower) altitude. The GCE model always simulates more stratiform rain (10 to 20%) than the radar for all three convective episodes. SSM/I derived stratiform amount is about 37% for December 19-27, 48% for December 11-17 and 41% for the February 9-13 case. Temporal variability of CSH algorithm retrieved latent heating profiles using either GCE model simulated or radar estimated rainfall and stratiform amount is in good

  8. Ultrathin ZnSe nanowires: one-pot synthesis via a heat-triggered precursor slow releasing route, controllable Mn doping and application in UV and near-visible light detection.

    PubMed

    Li, Dong; Xing, Guanjie; Tang, Shilin; Li, Xiaohong; Fan, Louzhen; Li, Yunchao

    2017-10-12

    We report herein a heat-triggered precursor slow releasing route for the one-pot synthesis of ultrathin ZnSe nanowires (NWs), which relies on the gradual dissolving of Se powder into oleylamine containing a soluble Zn precursor under heating. This route allows the reaction system to maintain a high monomer concentration throughout the entire reaction process, thus enabling the generation of ZnSe NWs with diameter down to 2.1 nm and length approaching 400 nm. The size-dependent optical properties and band-edge energy levels of the ZnSe NWs were then explored in depth by UV-visible spectroscopy and cyclic voltammetry, respectively. Considering their unique absorption properties, these NWs were specially utilized for fabricating photoelectrochemical-type photodetectors (PDs). Impressively, the PDs based on the ZnSe NWs with diameters of 2.1 and 4.5 nm exhibited excellent responses to UVA and near-visible light, respectively: both possessed ultrahigh on/off ratios (5150 for UVA and 4213 for near-visible light) and ultrawide linear response ranges (from 2.0 to 9000 μW cm(-2) for UVA and 5.0 to 8000 μW cm(-2) for near-visible light). Furthermore, these ZnSe NWs were selectively doped with various amounts of Mn(2+) to tune their emission properties. As a result, ZnSe NW film-based photochromic cards were creatively developed for visually detecting UVA and near-visible radiation.

  9. Heat pipe array heat exchanger

    DOEpatents

    Reimann, Robert C.

    1987-08-25

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

  10. Heat Sink Design and Optimization

    DTIC Science & Technology

    2015-12-01

    obtained using equation 2, the convective heat transfer coefficient for the U-channels can be calculated by...6) Radiation The procedure for calculating the radiative heat transfer coefficient for the U-channels...public release; distribution is unlimited. UNCLASSIFIED 7 The convective heat transfer coefficient for the vertical fins is defined as

  11. Syndactyly Release.

    PubMed

    Braun, Tara L; Trost, Jeffrey G; Pederson, William C

    2016-11-01

    Syndactyly is one of the most common congenital hand anomalies treated by pediatric plastic surgeons. Established principles of syndactyly separation dictate the timing and order of syndactyly release, with the goals of surgery being the creation of an anatomically normal webspace, tension-free closure of soft tissue, and return of function to the fingers. Numerous surgical methods have been described, many of which involve the use of local flaps to reconstruct the commissure and full-thickness skin grafts for coverage of raw areas. Recently, reconstructive techniques without the use of skin grafts have been devised, which work well for certain indications. Special considerations are described for complete, complex, and syndromic syndactylies. Outcomes for simple syndactyly release are typically good when surgical principles are followed, whereas complex syndactyly release tends to have less-favorable outcomes and more complications.

  12. 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.

  13. Thermo-sensitive nanoparticles for triggered release of siRNA.

    PubMed

    Yang, Zheng; Cheng, Qiang; Jiang, Qian; Deng, Liandong; Liang, Zicai; Dong, Anjie

    2015-01-01

    Efficient delivery of small interfering RNA (siRNA) is crucially required for cancer gene therapy. Herein, a thermo-sensitive copolymer with a simple structure, poly (ethylene glycol) methyl ether acrylate-b-poly (N-isopropylacrylamide) (mPEG-b-PNIPAM) was developed. A novel kind of thermo-sensitive nanoparticles (DENPs) was constructed for the cold-shock triggered release of siRNA by double emulsion-solvent evaporation method using mPEG-b-PNIPAM and a cationic lipid, 3β [N-(N', N'-dimethylaminoethane)-carbamoyl] cholesterol [DC-Chol]. DENPs were observed by transmission electron microscopy and dynamical light scattering before and after 'cold shock' treatment. The encapsulation efficiency (EE) of siRNA in DENPs, which was measured by fluorescence spectrophotometer was 96.8% while it was significantly reduced to be 23.2% when DC-Chol was absent. DENPs/siRNA NPs exhibited a thermo-sensitive siRNA release character that the cumulatively released amount of siRNA from cold shock was approximately 2.2 folds higher after 7 days. In vitro luciferase silencing experiments indicated that DENPs showed potent gene silencing efficacy in HeLa-Luc cells (HeLa cells steadily expressed luciferase), which was further enhanced by a cold shock. Furthermore, MTT assay showed that cell viability with DENPs/siRNA up to 200 nM remained above 80%. We also observed that most of siRNA was accumulated in kidney mediated by DENPs instead of liver and spleen in vivo experiments. Thus, DENPs as a cold shock responsive quick release model for siRNA or hydrophilic macromolecules delivery provide a new way to nanocarrier design and clinic therapy.

  14. Novel Heat Transfer Device Research

    DTIC Science & Technology

    2012-04-01

    Thermography Comparison of the Qu Tube with the Wicked Heat Pipe .................. 4 3.3 Quantitative Characterization of both Qu Tube and Heat Pipe...the Qu Tube operations in comparison with a wicked water heat pipe using the IR thermography . III. Quantitative characterization of both Qu Tubes...4 Approved for public release; distribution unlimited. Figure 2: X-Ray Images of Copper Heat Pipes 3.2 IR Thermography

  15. Application of curdlan to controlled drug delivery. III. Drug release from sustained release suppositories in vitro.

    PubMed

    Kanke, M; Tanabe, E; Katayama, H; Koda, Y; Yoshitomi, H

    1995-08-01

    The use of curdlan, a natural beta-1,3-glucan, in the preparation of sustained release suppositories was studied in vitro. To prepare the suppositories, indomethacin, prednisolone or salbutamol sulfate was mixed with curdlan gel. Preparation conditions, including heating time and curdlan concentrations of 5 and 10%, had little effect on the drug release. The tonicity (hypotonic or isotonic) of the media for the suppository preparation and for in vitro drug release study also had little effect on drug release. However, the heating temperature during gel preparation, the drug amount in the suppository and the type of release media did affect drug release. It was found that drug release was sustained and diffusion-controlled in the three drugs. And finally, curdlan can be applicable for use in a sustained release suppository.

  16. Heat Islands

    EPA Pesticide Factsheets

    EPA's Heat Island Effect Site provides information on heat islands, their impacts, mitigation strategies, related research, a directory of heat island reduction initiatives in U.S. communities, and EPA's Heat Island Reduction Program.

  17. 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.

  18. Cell swelling-induced ATP release is tightly dependent on intracellular calcium elevations

    PubMed Central

    Boudreault, Francis; Grygorczyk, Ryszard

    2004-01-01

    Mechanical stresses release ATP from a variety of cells by a poorly defined mechanism(s). Using custom-designed flow-through chambers, we investigated the kinetics of cell swelling-induced ATP secretion, cell volume and intracellular calcium changes in epithelial A549 and 16HBE14o− cells, and NIH/3T3 fibroblasts. Fifty per cent hypotonic shock triggered transient ATP release from cell confluent monolayers, which consistently peaked at around 1 min 45 s for A549 and NIH/3T3, and at 3 min for 16HBE14o− cells, then declined to baseline within the next 15 min. Whereas the release time course had a similar pattern for the three cell types, the peak rates differed significantly (294 ± 67, 70 ± 22 and 17 ± 2.8 pmol min−1 (106 cells)−1, for A549, 16HBE14o− and NIH/3T3, respectively). The concomitant volume changes of substrate-attached cells were analysed by a 3-dimensional cell shape reconstruction method based on images acquired from two perpendicular directions. The three cell types swelled at a similar rate, reaching maximal expansion in 1 min 45 s, but differed in the duration of the volume plateau and regulatory volume decrease (RVD). These experiments revealed that ATP release does not correlate with either cell volume expansion and the expected activation of stretch-sensitive channels, or with the activation of volume-sensitive, 5-nitro-2-(3-phenylpropylamino) benzoic acid-inhibitable anion channels during RVD. By contrast, ATP release was tightly synchronized, in all three cell types, with cytosolic calcium elevations. Furthermore, loading A549 cells with the calcium chelator BAPTA significantly diminished ATP release (71% inhibition of the peak rate), while the calcium ionophore ionomycin triggered ATP release in the absence of cell swelling. Lowering the temperature to 10°C almost completely abolished A549 cell swelling-induced ATP release (95% inhibition of the peak rate). These results strongly suggest that calcium-dependent exocytosis plays a

  19. 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

  20. 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

  1. Heat accumulator

    SciTech Connect

    Bracht, A.

    1981-09-29

    A heat accumulator comprises a thermally-insulated reservoir full of paraffin wax mixture or other flowable or meltable heat storage mass, heat-exchangers immersed in the mass, a heat-trap connected to one of the heat-exchangers, and a heat user connected to the other heat-exchanger. Pumps circulate fluids through the heat-trap and the heat-using means and the respective heat-exchangers, and a stirrer agitates and circulates the mass, and the pumps and the stirrer and electric motors driving these devices are all immersed in the mass.

  2. 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.

  3. 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.

  4. Silicon Heat Pipe Array

    NASA Technical Reports Server (NTRS)

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

    2013-01-01

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

  5. Heat pumps

    NASA Astrophysics Data System (ADS)

    Gilli, P. V.

    1982-11-01

    Heat pumps for residential/commercial space heating and hot tap water make use of free energy of direct or indirect solar heat and save from about 40 to about 70 percent of energy if compared to a conventional heating system with the same energy basis. In addition, the electrically driven compressor heat pump is able to substitute between 40% (bivalent alternative operation) to 100% (monovalent operation) of the fuel oil of an oilfired heating furnace. For average Central European conditions, solar space heating systems with high solar coverage factor show the following sequence of increasing cost effectiveness: pure solar systems (without heat pumps); heat pump assisted solar systems; solar assisted heat pump systems; subsoil/water heat pumps; air/water heat pumps; air/air heat pumps.

  6. 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.

  7. 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

  8. 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

  9. Heat Pipes

    ERIC Educational Resources Information Center

    Lewis, J.

    1975-01-01

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

  10. Heat Stress

    MedlinePlus

    ... Work in the Heat: Why Acclimatization Matters The natural adaptation to the heat takes time, and from a management perspective, it may require careful planning. NIOSH Science Blog: Extreme Heat – Are you prepared for summer ...

  11. Tidal Heating in Enceladus

    NASA Astrophysics Data System (ADS)

    Meyer, Jennifer; Wisdom, J.

    2007-07-01

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

  12. Modular passive solar heating system

    SciTech Connect

    Hunter, B.D.

    1985-03-19

    A modular passive solar energy storage system comprises a plurality of heat tubes which are arranged to form a flat plate solar collector and are releasably connected to a water reservoir by, and are part of, double-walled heat exchangers which penetrate to the water reservoir and enhance the heat transfer characteristics between the collector and the reservoir. The flat plate collector-heat exchanger disassembly, the collector housing, and the reservoir are integrated into a relatively light weight, unitary structural system in which the reservoir is a primary structural element. In addition to light weight, the system features high efficiency and ease of assembly and maintenance.

  13. Ultrafast radiative heat transfer.

    PubMed

    Yu, Renwen; Manjavacas, Alejandro; García de Abajo, F Javier

    2017-02-23

    Light absorption in conducting materials produces heating of their conduction electrons, followed by relaxation into phonons within picoseconds, and subsequent diffusion into the surrounding media over longer timescales. This conventional picture of optical heating is supplemented by radiative cooling, which typically takes place at an even lower pace, only becoming relevant for structures held in vacuum or under extreme thermal isolation. Here, we reveal an ultrafast radiative cooling regime between neighboring plasmon-supporting graphene nanostructures in which noncontact heat transfer becomes a dominant channel. We predict that more than 50% of the electronic heat energy deposited on a graphene disk can be transferred to a neighboring nanoisland within a femtosecond timescale. This phenomenon is facilitated by the combination of low electronic heat capacity and large plasmonic field concentration in doped graphene. Similar effects should occur in other van der Waals materials, thus opening an unexplored avenue toward efficient heat management.Electron relaxation, which is the dominant release channel of electronic heat in nanostructures, occurs with characteristic times of several picoseconds. Here, the authors predict that an ultrafast (femtosecond) radiative cooling regime takes place in plasmonically active neighboring graphene nanodisks prior to electron relaxation.

  14. 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.

  15. Complex coacervates for thermally sensitive controlled release of flavor compounds.

    PubMed

    Yeo, Yoon; Bellas, Evangelia; Firestone, William; Langer, Robert; Kohane, Daniel S

    2005-09-21

    To improve the appeal of frozen baked foods upon heating, we have encapsulated flavor oil in complex coacervate microcapsules using gelatin and gum Arabic. Variation of polyion concentrations and homogenization rate affected particle morphology, size distribution, and oil release upon heating. Release of the oil from formulations was determined by a simple spectroscopic method based on separation of oil labeled with a lipophilic dye from unaffected particles. When heated to 100 degrees C or higher, univesicular microcapsules (prepared with a lower homogenization rate) released almost all of the encapsulated oil, while multivesicular microcapsules (produced by high homogenization rates) resulted had lesser degrees of release. The oil remained encapsulated during 4 weeks of storage at 4 and -20 degrees C (freezing and thawing) but was released by exposure to 100 mM NaCl at room temperature. When particles were cooled after releasing their oil content, the oil was re-encapsulated.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. Reusable Release Mechanism

    NASA Technical Reports Server (NTRS)

    Bunker, J. W.; Ritchie, R. S.

    1984-01-01

    Slider release mechanism reusable. Bears heavy loads while latched, yet gives smooth release motion. Release effected by explosively driving perpendicular slider out of engagement with load-bearing shank. Device has potential industrial applications such as emergency release of lifting cables from helicopters, cranes and hoists.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. Major Volatiles Released from the Fourth John Klein Portion

    NASA Image and Video Library

    2013-04-08

    As the Sample Analysis at Mars SAM suite of instruments on NASA Curiosity Mars rover heats a sample, gases are released or evolved from the sample and can be identified using SAM quadrupole mass spectrometer.

  7. 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.

  8. Heating apparatus

    SciTech Connect

    Woo, C.G.

    1991-07-30

    This patent describes a heating apparatus. It comprises a housing, means for introducing water to a plurality of water conduits of the housing, a fireplace compartment disposed within the housing, the fireplace compartment being provided with a burner, a fin coil member disposed in the upper portion of the housing and communicating with the room environment for heat emitting, the fin coil member containing a serpentine configured fin coils disposed therein for absorbing heat from the water disposed in the water conduits, a heat chamber containing the water conduits, the heat chamber connected at one end to the fireplace compartment and at the other end to a chimney disposed at the middle of the the fireplace compartment for circulating hot combustion gases therethrough and for heating the water disposed in the water conduits, the combustion gases being vented from the chimney, and at least four turbo fans communicating with the heat chamber for blowing air across the fin coil member so as to heat the air and discharge it to the room environment, and reduce noise pollution of the heating apparatus.

  9. Study on Supercooling Release in Encapsulated Ice System

    NASA Astrophysics Data System (ADS)

    Tsuchiya, Yooko; Hasagawa, Hiromi; Iwatsubo, Tetsushiro

    As regards the super cooling phenomena which is important matter in encapsulated ice system, the system efficient suffering from the super cooling release of water was estimated and the performance of release reagent was determined. The following conclusions were reached. (1) It was clear that the COP of heat storing of the system fell by 3% with decreasing release temperature by 1 degree centigrade. (2) As a result of determinations about release reagents, Xanthomonas campestris (ice nuclei bacteria) was very effective in release the super cooling state, and the performance was maintained in continuous application of freezing and melting.

  10. 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.

  11. Latent Heating from TRMM Satellite Measurements

    NASA Astrophysics Data System (ADS)

    Tao, W.; Takayabu, Y. N.; Shige, S.; Lang, S. E.; Olson, W. S.

    2012-12-01

    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 within the Tropics - as well as modify the energetic efficiencies of mid-latitude weather systems. This paper highlights 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. A set of algorithm methodologies has been 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 generated 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.

  12. 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)…

  13. 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)…

  14. Heat transfer in microwave heating

    NASA Astrophysics Data System (ADS)

    Peng, Zhiwei

    Heat transfer is considered as one of the most critical issues for design and implement of large-scale microwave heating systems, in which improvement of the microwave absorption of materials and suppression of uneven temperature distribution are the two main objectives. The present work focuses on the analysis of heat transfer in microwave heating for achieving highly efficient microwave assisted steelmaking through the investigations on the following aspects: (1) characterization of microwave dissipation using the derived equations, (2) quantification of magnetic loss, (3) determination of microwave absorption properties of materials, (4) modeling of microwave propagation, (5) simulation of heat transfer, and (6) improvement of microwave absorption and heating uniformity. Microwave heating is attributed to the heat generation in materials, which depends on the microwave dissipation. To theoretically characterize microwave heating, simplified equations for determining the transverse electromagnetic mode (TEM) power penetration depth, microwave field attenuation length, and half-power depth of microwaves in materials having both magnetic and dielectric responses were derived. It was followed by developing a simplified equation for quantifying magnetic loss in materials under microwave irradiation to demonstrate the importance of magnetic loss in microwave heating. The permittivity and permeability measurements of various materials, namely, hematite, magnetite concentrate, wüstite, and coal were performed. Microwave loss calculations for these materials were carried out. It is suggested that magnetic loss can play a major role in the heating of magnetic dielectrics. Microwave propagation in various media was predicted using the finite-difference time-domain method. For lossy magnetic dielectrics, the dissipation of microwaves in the medium is ascribed to the decay of both electric and magnetic fields. The heat transfer process in microwave heating of magnetite

  15. 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.

  16. Effect of transfer of one or two in vitro-produced embryos and post-transfer administration of gonadotropin releasing hormone on pregnancy rates of heat-stressed dairy cattle.

    PubMed

    Franco, M; Block, J; Jousan, F D; de Castro e Paula, L A; Brad, A M; Franco, J M; Grisel, F; Monson, R L; Rutledge, J J; Hansen, P J

    2006-07-15

    Pregnancy rates following transfer of an in vitro-produced (IVP) embryo are often lower than those obtained following transfer of an embryo produced by superovulation. The purpose of the current pair of experiments was to examine two strategies for increasing pregnancy rates in heat stressed, dairy recipients receiving an IVP embryo. One method was to transfer two embryos into the uterine horn ipsilateral to the CL, whereas the other method involved injection of GnRH at Day 11 after the anticipated day of ovulation. In Experiment 1, 32 virgin crossbred heifers and 26 lactating crossbred cows were prepared for timed embryo transfer by being subjected to a timed ovulation protocol. Those having a palpable CL were randomly selected to receive one (n = 31 recipients) or two (n = 27 recipients) embryos on Day 7 after anticipated ovulation. At Day 64 of gestation, the pregnancy rate tended to be higher (P = 0.07) for cows than for heifers. Heifers that received one embryo tended to have a higher pregnancy rate than those that received two embryos (41% versus 20%, respectively) while there was no difference in pregnancy rate for cows that received one or two embryos (57% versus 50%, respectively). Pregnancy loss between Day 64 and 127 only occurred for cows that received two embryos (pregnancy rate at Day 127=17%). Between Day 127 and term, one animal (a cow with a single embryo) lost its pregnancy. There was no difference in pregnancy rates at Day 127 or calving rates between cows and heifers, but females that received two embryos had lower Day-127 pregnancy rates and calving rates than females that received one embryo (P < 0.03). Of the females receiving two embryos that calved, 2 of 5 gave birth to twins. For Experiment 2, 87 multiparous, late lactation, nonpregnant Holstein cows were synchronized for timed embryo transfer as in Experiment 1. Cows received a single embryo in the uterine horn ipsilateral to the ovary containing the CL and received either 100 microg Gn

  17. [Lateral retinacular release].

    PubMed

    Verdonk, P; Bonte, F; Verdonk, R

    2008-09-01

    This overview of numerous studies discusses, based on short-term and long-term results, which diagnoses are indications for lateral retinacular release. No significant differences in outcome between arthroscopic and open lateral release could be documented. Isolated lateral release offers a good success rate for treating a stable patella with excessive lateral pressure. In patellar instability, the results are less favorable in long-term follow-up evaluation. Hyperlaxity with hypermobility of the patella is an absolute contraindication. Lateral release provides only temporary benefit for patellofemoral osteoarthritis. Proximal and/or distal realignment of the extensor mechanism gives better results than isolated lateral release.

  18. 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.

  19. 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.

  20. 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.

  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. 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.

  3. 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.

  4. 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

  5. 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.

  6. Extended-release oxybutynin.

    PubMed

    Comer, A M; Goa, K L

    2000-02-01

    Extended-release oxybutynin (Ditropan XL) uses an osmotic system (OROS) to deliver a controlled amount of oxybutynin chloride into the gastrointestinal tract over a 24-hour period when taken once daily. Oxybutynin binds to M3 muscarinic receptors on the detrusor muscle of the bladder, preventing acetylcholinergic activation and relaxing the muscle. Mean peak plasma concentrations are lower with extended-release oxybutynin 15mg once daily than with conventional immediate-release oxybutynin 5mg taken 3 times daily. Relative bioavailabilities of parent drug and metabolite N-desethoxybutynin are 153 and 69%, respectively, for extended-release oxybutynin when compared with immediate-release oxybutynin. In short (< or =6 weeks) randomised, double-blind clinical trials of patients with detrusor instability, extended-release oxybutynin 5 to 30mg once daily significantly reduced the mean weekly number of urge incontinence episodes by 84 to 90%. Extended-release oxybutynin had similar efficacy to immediate-release oxybutynin. Adverse events reported by patients taking extended-release oxybutynin were dose-related anticholinergic effects, most frequently dry mouth, somnolence, constipation, blurred vision and dizziness. A large noncomparative study demonstrated that approximately two thirds of the patients prescribed extended-release oxybutynin for detrusor instability were still taking the medication 6 months later.

  7. Resistance heating elements with specific heating profiles

    NASA Technical Reports Server (NTRS)

    Hirschberg, M. H.

    1976-01-01

    Bundled, interrupted, resistance heating elements provide specific heating profiles. Design allows for easily tailored lengths and locations of "hot sections" and larger surface areas for heat radiation.

  8. Microwave pretreatment for enhancement of phosphorus release from dairy manure.

    PubMed

    Pan, Szu-Hua; Lo, Kwang Victor; Liao, Ping Huang; Schreier, Hans

    2006-01-01

    Both the advanced oxidation process (AOP) using a combination of hydrogen peroxide addition and microwave heating (H2O2/microwave), and the microwave heating process were used for solubilization of phosphorus from liquid dairy manure. About 80% of total phosphate was released into the solution at a microwave heating time of 5 min at 170 degrees C. With an addition of H2O2, more than 81% of total phosphate could be released over a reaction period of 49 h at ambient temperature. The AOP process could achieve up to 85% of total phosphate release at 120 degrees C. The results indicated that both the microwave, and the AOP processes could effectively release phosphate from liquid dairy manure. These processes could serve as pretreatments for phosphorus recovery from animal wastes, and could be combined with the struvite crystallization process to provide a new approach in treating animal wastes.

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

    NASA Technical Reports Server (NTRS)

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

    1979-01-01

    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 rates of multilayered seat materials were then measured at heat fluxes of 1.5 and 3.5 W/sq cm. Choices of contact and silicone adhesives for bonding multilayered assemblies were based on flammability, burn and smoke generation, animal toxicity tests, and thermal gravimetric analysis. Abrasion tests were conducted on the decorative fabric covering and slip sheet to ascertain service life and compatibility of layers.

  10. 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.

  11. 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.

  12. 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)

  13. Use of insulin-like growth factor-I during embryo culture and treatment of recipients with gonadotropin-releasing hormone to increase pregnancy rates following the transfer of in vitro-produced embryos to heat-stressed, lactating cows.

    PubMed

    Block, J; Drost, M; Monson, R L; Rutledge, J J; Rivera, R M; Paula-Lopes, F F; Ocon, O M; Krininger, C E; Liu, J; Hansen, P J

    2003-06-01

    An experiment was conducted to determine whether pregnancy rates following the transfer of in vitro-produced embryos to heat-stressed cows could be improved by 1) culturing embryos in the presence of IGF-I and 2) treating recipients with GnRH. Lactating Holstein cows (n = 260) were synchronized using a timed ovulation protocol. Embryos were produced in vitro and cultured with or without 100 ng/mL of IGF-I. On d 7 after anticipated ovulation (d 0), a single embryo was transferred to all recipients with a palpable corpus luteum (n = 210). A subset of recipients (n = 164) was injected with either GnRH or placebo on d 11. Plasma progesterone concentrations on d 0 and 7 were used to determine the synchrony of recipients. Pregnancy was diagnosed at d 53 and 81 by rectal palpation. Among all recipients, transfer of IGF-I-treated embryos increased pregnancy rate at d 53 (P < 0.05) and tended to increase pregnancy rate at d 81 (P < 0.06). Calving rate also tended to be higher for recipients that received IGF-I-treated embryos (P < 0.07). Among the subset of synchronized recipients (n = 190), pregnancy rate at d 53 and d 81 and calving rate were higher (P < 0.05) for IGF-I-treated embryos. The GnRH tended to increase pregnancy rate at d 53 for all recipients (P < 0.08) and the subset of synchronized recipients (P < 0.10). There were no effects of GnRH (P > 0.10) for pregnancy rate at d 81 and calving rate. The overall proportion of male calves was 64.3%. There was no effect (P > 0.10) of embryo treatment or GnRH on the birth weight or sex ratio of calves. Results of this experiment indicate that treatment of embryos with IGF-I can improve pregnancy and calving rates following transfer of in vitro-produced embryos. Further research is necessary to determine whether the treatment of recipients with GnRH is a practical approach to increase pregnancy rates following in vitro embryo transfer.

  14. Dendritic Release of Neurotransmitters.

    PubMed

    Ludwig, Mike; Apps, David; Menzies, John; Patel, Jyoti C; Rice, Margaret E

    2016-12-06

    Release of neuroactive substances by exocytosis from dendrites is surprisingly widespread and is not confined to a particular class of transmitters: it occurs in multiple brain regions, and includes a range of neuropeptides, classical neurotransmitters, and signaling molecules, such as nitric oxide, carbon monoxide, ATP, and arachidonic acid. This review is focused on hypothalamic neuroendocrine cells that release vasopressin and oxytocin and midbrain neurons that release dopamine. For these two model systems, the stimuli, mechanisms, and physiological functions of dendritic release have been explored in greater detail than is yet available for other neurons and neuroactive substances. © 2017 American Physiological Society. Compr Physiol 7:235-252, 2017.

  15. 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.…

  16. Modular Heat Exchanger With Integral Heat Pipe

    NASA Technical Reports Server (NTRS)

    Schreiber, Jeffrey G.

    1992-01-01

    Modular heat exchanger with integral heat pipe transports heat from source to Stirling engine. Alternative to heat exchangers depending on integrities of thousands of brazed joints, contains only 40 brazed tubes.

  17. Chromospheric Heating

    NASA Astrophysics Data System (ADS)

    Musielak, Z. E.

    2002-05-01

    It is now well-established that the Sun and all other late-type stars show chromospheric activity, which is typically identified with the presence of emission in the cores of Ca II and Mg II spectral lines. This activity varies significantly for a given spectral type and a star is more active when a larger portion of its surface is covered by magnetic fields. For stars of very low activity, a minimum core emission flux ("basal flux") has been observed. To explain the required heating and the observed range of activity, two classes of heating mechanisms have been considered: (1) dissipation of acoustic and magnetic waves generated in stellar convection zones; and (2) dissipation of currents generated by photospheric motions of surface magnetic fields. I will review both classes of heating mechanisms and discuss recent results which demonstrate that theoretical models of stellar chromospheres based on the wave heating (1) can explain the "basal flux" and the observed Ca II emission in most stars but cannot account for the observed Mg II emission in active stars. I will also present theoretical arguments which imply that the base of stellar chromospheres is heated by acoustic waves, the heating of the middle and upper chromospheric layers is dominated by magnetic waves associated with magnetic flux tubes, and that other non-wave (2) heating mechanisms are required to explain the structure of the highest layers of stellar chromospheres in active stars. This work was supported by NSF under grant ATM-0087184, NATO under grant CRG-910058 and The Alexander von Humboldt Foundation.

  18. Magnetar Heating

    NASA Astrophysics Data System (ADS)

    Beloborodov, Andrei M.; Li, Xinyu

    2016-12-01

    We examine four candidate mechanisms that could explain the high surface temperatures of magnetars. (1) Heat flux from the liquid core heated by ambipolar diffusion. It could sustain the observed surface luminosity {{\\mathscr{L}}}s≈ {10}35 erg s-1 if core heating offsets neutrino cooling at a temperature {T}{core}\\gt 6× {10}8 K. This scenario is viable if the core magnetic field exceeds 1016 G and the heat-blanketing envelope of the magnetar has a light-element composition. However, we find that the lifetime of such a hot core should be shorter than the typical observed lifetime of magnetars. (2) Mechanical dissipation in the solid crust. This heating can be quasi-steady, powered by gradual (or frequent) crustal yielding to magnetic stresses. We show that it obeys a strong upper limit. As long as the crustal stresses are fostered by the field evolution in the core or Hall drift in the crust, mechanical heating is insufficient to sustain persistent {{\\mathscr{L}}}s≈ {10}35 erg s-1. The surface luminosity is increased in an alternative scenario of mechanical deformations triggered by external magnetospheric flares. (3) Ohmic dissipation in the crust, in volume or current sheets. This mechanism is inefficient because of the high conductivity of the crust. Only extreme magnetic configurations with crustal fields B\\gt {10}16 G varying on a 100 meter scale could provide {{\\mathscr{L}}}s≈ {10}35 erg s-1. (4) Bombardment of the stellar surface by particles accelerated in the magnetosphere. This mechanism produces hot spots on magnetars. Observations of transient magnetars show evidence of external heating.

  19. 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.

  20. Indirectly-heated biomass gasification using latent-heat ballasting of a fluidized reactor

    SciTech Connect

    Stobbe, S.; Oatley, J.; Brown, R.C.

    1996-12-31

    The objective of this study is to improve heating value and methane content of gas produced from biomass gasification. This project investigates a latent-heat ballasted, indirectly-heated gasifier. The latent-heat ballast consists of metal alloy with melting point close to the desired gasification temperature. The ballast allows a single reactor to sustain pyrolysis without oxygen addition by storing energy during periods of combustion and releasing stored energy during periods of pyrolysis. Tests were performed to evaluate the heat transfer and gasification characteristics of the ballasted reactor.

  1. 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.

  2. Heat Pipes

    NASA Astrophysics Data System (ADS)

    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.

  3. 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.

  4. 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.

  5. 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.

  6. Ion release and cytotoxicity of stainless steel wires.

    PubMed

    Oh, Keun-Taek; Kim, Kyoung-Nam

    2005-12-01

    Heat treatment is generally applied to orthodontic stainless steel (SS) wires to relieve the stresses that result from their manipulation by orthodontists. The quality and thickness of the oxide films formed on the surface of heat-treated wires can vary, and it is believed that these oxide films can influence the properties of heat-treated wires. The aim of this study was to investigate the influence of heat treatment and cooling methods on the amount of metal ions released and to examine the cytotoxicity of heat-treated wires. In this study, four types of SS wires (Remanium, Permachrome, Colboloy and Orthos) with a cross-sectional area of 0.41 x 0.56 mm were investigated. These wires were heat-treated in a vacuum, air, or argon environment, and were cooled in either a furnace or a water bath. Four control groups and 24 experimental groups were classified according to the type of wires, heat treatment conditions and cooling methods. In each group, the amount of nickel released as well as its cytotoxicity was investigated. The concentration of dissolved nickel ions in artificial saliva was measured for a period of up to 12 weeks. In all groups, the concentration of dissolved nickel ions in artificial saliva was lowest for the vacuum heat treatment-furnace cooling group and a significant difference was shown compared with the other experimental groups. The concentration of dissolved nickel ions in artificial saliva was highest in the groups heat-treated in air (P < 0.05), while the amount of nickel released was highest in the Remanium and Colboloy (P < 0.05). The cytotoxicity was mild in all the experimental groups but the response index of the air groups was slightly higher than in the other groups. According to these results, SS wires retain their high corrosion resistance and low ion release rate when heat-treated in a vacuum and cooled in a furnace.

  7. 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.

  8. Heat generation in aircraft tires

    NASA Technical Reports Server (NTRS)

    Clark, S. K.

    1983-01-01

    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.

  9. 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.

  10. 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.

  11. 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)

  12. Chromospheric heating

    NASA Technical Reports Server (NTRS)

    Kalkofen, Wolfgang

    1989-01-01

    The solar chromosphere is identified with the atmosphere inside magnetic flux tubes. Between the temperature minimum and the 7000 K level, the chromosphere in the bright points of the quiet sun is heated by large-amplitude, long-period, compressive waves with periods mainly between 2 and 4 minutes. These waves do not observe the cutoff condition according to which acoustic waves with periods longer than 3 minutes do not propagate vertically in the upper solar photosphere. It is concluded that the long-period waves probably supply all the energy required for the heating of the bright points in the quiet solar chromosphere.

  13. 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…

  14. 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…

  15. Renewable Heating and Cooling

    EPA Pesticide Factsheets

    Renewable heating and cooling is a set of alternative resources and technologies that can be used in place of conventional heating and cooling technologies for common applications such as water heating, space heating, space cooling and process heat.

  16. 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.

  17. Latent heat effects in subsurface heat transport modelling and their impact on palaeotemperature reconstructions

    NASA Astrophysics Data System (ADS)

    Mottaghy, Darius; Rath, Volker

    2006-01-01

    In cold regions the thermal regime is strongly affected by freezing or melting processes, consuming or releasing large amounts of latent heat. This changes enthalpy by orders of magnitude. We present a numerical approach for the implementation of these effects into a 3-D finite-difference heat transport model. The latent heat effect can be handled by substituting an apparent heat capacity for the volumetric heat capacity of unfrozen soil in the heat transfer equation. The model is verified by the analytical solution of the heat transport equation including phase change. We found significant deviations of temperature profiles when applying the latent heat effect on forward calculations of deep temperature logs. Ground surface temperature histories derived from synthetic data and field data from NE Poland underline the importance of considering freezing processes. In spite of its limitations, the proposed method is appropriate for the study of long-period climatic changes.

  18. Infrared heating

    USDA-ARS?s Scientific Manuscript database

    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...

  19. Heat exchanger

    DOEpatents

    Wolowodiuk, Walter

    1976-01-06

    A heat exchanger of the straight tube type in which different rates of thermal expansion between the straight tubes and the supply pipes furnishing fluid to those tubes do not result in tube failures. The supply pipes each contain a section which is of helical configuration.

  20. Flash Heating

    NASA Astrophysics Data System (ADS)

    Taylor, G. J.

    2000-03-01

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

  1. 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.

  2. 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.

  3. Release of hydrogen from nanoconfined hydrides by application of microwaves

    NASA Astrophysics Data System (ADS)

    Sanz-Moral, Luis Miguel; Navarrete, Alexander; Sturm, Guido; Link, Guido; Rueda, Miriam; Stefanidis, Georgios; Martín, Ángel

    2017-06-01

    The release of hydrogen from solid hydrides by thermolysis can be improved by nanoconfinement of the hydride in a suitable micro/mesoporous support, but the slow heat transfer by conduction through the support can be a limitation. In this work, a C/SiO2 mesoporous material has been synthesized and employed as matrix for nanoconfinement of hydrides. The matrix showed high surface area and pore volume (386 m2/g and 1.41 cm3/g), which enabled the confinement of high concentrations of hydride. Furthermore, by modification of the proportion between C and SiO2, the dielectric properties of the complex could be modified, making it susceptible to microwave heating. As with this heating method the entire sample is heated simultaneously, the heat transfer resistances associated to conduction were eliminated. To demonstrate this possibility, ethane 1,2-diaminoborane (EDAB) was embedded on the C/SiO2 matrix at concentrations ranging from 11 to 31%wt using a wet impregnation method, and a device appropriate for hydrogen release from this material by application of microwaves was designed with the aid of a numerical simulation. Hydrogen liberation tests by conventional heating and microwaves were compared, showing that by microwave heating hydrogen release can be initiated and stopped in shorter times.

  4. The role of compressibility in energy release by magnetic reconnection

    SciTech Connect

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

    2012-08-15

    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{sup 3} to 10{sup 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.

  5. 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.

  6. DSCOVR Public Release Statement

    Atmospheric Science Data Center

    2016-11-23

    ... DSCOVR Public Release Statement Wednesday, July 20, 2016 The Deep Space Climate Observatory (DSCOVR) is a ... is limited to the near infrared solar reflected signal. The fourth detector is a high signal-to-noise photodiode spanning UV, Visible, and ...

  7. The 2017 Release Cloudy

    NASA Astrophysics Data System (ADS)

    Ferland, G. J.; Chatzikos, M.; Guzmán, F.; Lykins, M. L.; van Hoof, P. A. M.; Williams, R. J. R.; Abel, N. P.; Badnell, N. R.; Keenan, F. P.; Porter, R. L.; Stancil, P. C.

    2017-10-01

    We describe the 2017 release of the spectral synthesis code Cloudy, summarizing the many improvements to the scope and accuracy of the physics which have been made since the previous release. Exporting the atomic data into external data files has enabled many new large datasets to be incorporated into the code. The use of the complete datasets is not realistic for most calculations, so we describe the limited subset of data used by default, which predicts significantly more lines than the previous release of Cloudy. This version is nevertheless faster than the previous release, as a result of code optimizations. We give examples of the accuracy limits using small models, and the performance requirements of large complete models. We summarize several advances in the H- and He-like iso-electronic sequences and use our complete collisional-radiative models to establish the densities where the coronal and local thermodynamic equilibrium approximations work.

  8. Rad-Release

    ScienceCinema

    None

    2016-07-12

    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/

  9. 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/

  10. 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.

  11. 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.

  12. Geothermal heating

    SciTech Connect

    Aureille, M.

    1982-01-01

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

  13. Heat pump

    SciTech Connect

    Apte, A.J.

    1982-11-30

    A single working fluid heat pump system having a turbocompressor with a first fluid input for the turbine and a second fluid input for the compressor, and a single output volute or mixing chamber for combining the working fluid output flows of the turbine and the compressor. The system provides for higher efficiency than single fluid systems whose turbine and compressor are provided with separate output volutes.

  14. Magnetic-Responsive Release Controlled by Hot Spot Effect.

    PubMed

    Guisasola, Eduardo; Baeza, Alejandro; Talelli, Marina; Arcos, Daniel; Moros, María; de la Fuente, Jesús M; Vallet-Regí, María

    2015-11-24

    Magnetically triggered drug delivery nanodevices have attracted great attention in nanomedicine, as they can feature as smart carriers releasing their payload at clinician's will. The key principle of these devices is based on the properties of magnetic cores to generate thermal energy in the presence of an alternating magnetic field. Then, the temperature increase triggers the drug release. Despite this potential, the rapid heat dissipation in living tissues is a serious hindrance for their clinical application. It is hypothesized that magnetic cores could act as hot spots, this is, produce enough heat to trigger the release without the necessity to increase the global temperature. Herein, a nanocarrier has been designed to respond when the temperature reaches 43 °C. This material has been able to release its payload under an alternating magnetic field without the need of increasing the global temperature of the environment, proving the efficacy of the hot spot mechanism in magnetic-responsive drug delivery devices.

  15. Novel particle release patterns for increased receiver thermal efficiency

    NASA Astrophysics Data System (ADS)

    Mills, Brantley; Ho, Clifford K.; Christian, Joshua M.; Peacock, Gregory

    2017-06-01

    Novel particle release patterns have been investigated for falling particle receivers. Zig-zag, wave-like, and multiple parallel particle curtains have been simulated and compared to a conventional planar particle curtain. Simulations show that particle release patterns that promote light-trapping through non-planar features and volumetric heating can increase the thermal efficiency of particle receivers by nearly 10%, despite an increase in convective heat loss. Multiple parallel curtains yielded the highest efficiencies overall, while larger amplitudes and high frequencies in the wave-like patterns yielded high efficiencies relative to the baseline planar case. Thermal efficiency increased with increasing mass flow rate for all cases (up to 12.5 kg/s-m), while the relative improvement of the alternative release patterns decreased relative to the baseline. Testing has demonstrated the ability to implement these alternative release patterns using discharge plates that have machined slots of the desired pattern.

  16. Heat Release Rates for Shipboard Dry Goods Storage Space Materials

    DTIC Science & Technology

    2007-05-04

    ODMs ); and 6. Thermal imaging and visible light video cameras to record the development of the fires. 4 This space was previously used for studies...density meters ( ODMs ) Four ODMs were installed on two different levels at each of the two locations shown in Figure 4. The lower level instruments were...represent head heights for crawling and standing persons, respectively. The ODMs used low power lasers to monitor optical transmittance over a path

  17. 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

  18. 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.

  19. 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.

  20. Data summary report for fission product release test VI-4

    SciTech Connect

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

    1991-01-01

    This was the fourth in a series of high-temperature fission product release tests in a vertical test apparatus. The test specimen, a 15.2-cm-long section of a fuel rod from the BR3 reactor in Belgium, had been irradiated to a burnup of 47 MWd/kg. In simulation of a severe accident in a light-water reactor, it was heated in hydrogen in a hot cell-mounted test apparatus to a maximum test temperature of 2400 K for a period of 20 min. The released fission products were collected on components designed to facilitate sampling and analysis. On-line radioactivity measurements and posttest inspection revealed that the fuel had partially collapsed at about the time the cladding melted. Based on fission product inventories measured in the fuel or calculated by ORIGEN2, analyses of test components showed total releases from the fuel of 85% for {sup 85}Kr, <1% for {sup 106}Ru, 3.9% for {sup 125}Sb, 96% for both {sup 134}Cs and {sup 137}Cs, and 13% for {sup 154}Eu. Large fractions of the released fission products (up to 96% of the {sup 154}Eu) were retained in the furnace. Small release fractions for several other fission products -- Rb, Br, Sr, Te, I, and Ba -- were detected also. In addition, very small amounts of fuel material -- uranium and plutonium -- were released. Total mass release from the furnace to the collection system, which included fission products, fuel material, and structural materials, was 0.40g, with 40% of this material being deposited as vapor and 60% of it being collected as aerosols. The results from this test were compared with previous tests in this series and with an in-pile test at similar conditions at Sandia National Laboratories. There was no indication that the mode of heating (fission heat vs radiant heat) significantly affected fission product release. 24 refs., 25 figs., 14 tabs.

  1. Heat-Exchanger/Heat-Pipe Interface

    NASA Technical Reports Server (NTRS)

    Snyder, H. J.; Van Hagan, T. H.

    1987-01-01

    Monolithic assembly reliable and light in weight. Heat exchanger and evaporator ends of heat pipes integrated in monolithic halves welded together. Interface assembly connects heat exchanger of furnace, reactor, or other power source with heat pipes carrying heat to radiator or power-consuming system. One of several concepts proposed for nuclear power supplies aboard spacecraft, interface useful on Earth in solar thermal power systems, heat engines, and lightweight cooling systems.

  2. 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.

  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. Temporal control of drug release from biodegradable polymer: multicomponent diclofenac sodium releasing PLGA 80/20 rod.

    PubMed

    Nikkola, Lila; Viitanen, Petrus; Ashammakhi, Nureddin

    2009-05-01

    In our previous studies we have reported on the development of diclofenac sodium (DS) releasing rods. However, their drug release profiles were unsatisfactory. To enhance the drug release properties of the implant, we have developed a system whereby various elements can be combined into one implant. Melt extruded, self-reinforced (SR), and sterilized (S) DS-containing SR-PLGA 80/20 billets were combined to produce multicomponent implants with various compositions. These components were basically heat pressed together to form multicomponent rods. Drug release from single component and multicomponent rods was defined using a UV-Vis spectrophotometer. DS was released from individual components within 82-111 days and from multicomponent rods within 50-70 days. Thermal properties were analyzed using differential scanning calorimetry (DSC). The melting temperature (T(m)) of multicomponent implants was about 157 degrees C, change in heat fusion (DeltaH) was 13.3 J/g, and the glass transition temperature (T(g)) was 55.4 degrees C. Mechanical strength was measured for 2 weeks and it decreased from 55 to 15 MPa. In conclusion, by compression molding three components with different release rates it is possible to control the temporal release from multicomponent rods. Released DS concentrations were within range for 49-74 days depending on the fractions of individual components used.

  5. 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.

  6. Heat pipe waste heat recovery boilers

    NASA Astrophysics Data System (ADS)

    Littwin, D. A.; McCurley, J.

    The use of heat pipes as transport devices in waste heat recovery boilers is examined. Test results show that heat pipes can efficiently extract heat from the hot gas stream and transfer it inside the pressure vessel for the steam generation process. The benefits of incorporating heat pipes into the design of waste heat recovery boilers include a highly compact package, a significant reduction in thermally induced stresses, double isolation of the steam from the heat source, an extended surface for improved efficiency in heat extraction, improved circulation and stability in the boiling regime, easy cleaning, individually replaceable tubes, and low flue gas pressure drop.

  7. Heating systems for heating subsurface formations

    DOEpatents

    Nguyen, Scott Vinh [Houston, TX; Vinegar, Harold J [Bellaire, TX

    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. A fluoride release-adsorption-release system applied to fluoride-releasing restorative materials.

    PubMed

    Suljak, J P; Hatibovic-Kofman, S

    1996-09-01

    This investigation compared the initial fluoride release and release following refluoridation of three resin-modified glass-ionomer cements (Photac-Fil Applicap, Vitremer, and Fuji II LC) and a new polyacid-modified resin composite material (Dyract). After daily flouride release was measured for 8 days, specimens were refluoridated in 1,000-ppm solutions of fluoride ion for 10 minutes and fluoride release was measured for 5 days. Two further 5-day refluoridation-release periods were carried out. All materials released fluoride initially. Photac released the most; Dyract released the least. Initial release was greatest over the first few days. All materials released significantly more fluoride for 24 to 48 hours after refluoridation. Less fluoride was released with each successive refluoridation for the three glass-ionomer cements. The release from the Dyract compomer remained at a comparatively constant and significantly lower level following each refluoridation.

  9. 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.

  10. RAVEN Beta Release

    SciTech Connect

    Rabiti, Cristian; Alfonsi, Andrea; Cogliati, Joshua Joseph; Mandelli, Diego; Kinoshita, Robert Arthur; Wang, Congjian; Maljovec, Daniel Patrick; Talbot, Paul William

    2016-02-01

    This documents the release of the Risk Analysis Virtual Environment (RAVEN) code. A description of the RAVEN code is provided, and discussion of the release process for the M2LW-16IN0704045 milestone. The RAVEN code is a generic software framework to perform parametric and probabilistic analysis based on the response of complex system codes. RAVEN is capable of investigating the system response as well as the input space using Monte Carlo, Grid, or Latin Hyper Cube sampling schemes, but its strength is focused toward system feature discovery, such as limit surfaces, separating regions of the input space leading to system failure, using dynamic supervised learning techniques. RAVEN has now increased in maturity enough for the Beta 1.0 release.

  11. 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.

  12. Controlled-release microchips.

    PubMed

    Sharma, Sadhana; Nijdam, A Jasper; Sinha, Piyush M; Walczak, Robbie J; Liu, Xuewu; Cheng, Mark M-C; Ferrari, Mauro

    2006-05-01

    Efficient drug delivery remains an important challenge in medicine: continuous release of therapeutic agents over extended time periods in accordance with a predetermined temporal profile; local delivery at a constant rate to the tumour microenvironment to overcome much of the systemic toxicity and to improve antitumour efficacy; improved ease of administration, and increasing patient compliance required are some of the unmet needs of the present drug delivery technology. Microfabrication technology has enabled the development of novel controlled-release microchips with capabilities not present in the current treatment modalities. In this review, the current status and future prospects of different types of controlled-release microchips are summarised and analysed with reference to microneedle-based microchips, as well as providing an in-depth focus on microreservoir-based and nanoporous microchips.

  13. Regenerative Hydride Heat Pump

    NASA Technical Reports Server (NTRS)

    Jones, Jack A.

    1992-01-01

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

  14. 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.

  15. 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.

  16. Nonenzymatic release of free reducing glycans from glycosphingolipids.

    PubMed

    Song, Xuezheng; Smith, David F; Cummings, Richard D

    2012-10-01

    A major limitation in studying the structures and functions of glycans in glycosphingolipids is the difficulty in releasing free glycans for analysis and derivatization. Here we show that reducing glycans can be released nonenzymatically from glycosphingolipids after a brief treatment with ozone followed by heating in neutral aqueous buffer (pHs 6.0-8.0). The released free reducing glycans are then available for glycomic analyses, including fluorescent labeling, permethylation, and mass spectrometry. This procedure is simple and highly efficient, with no base-catalyzed "peeling" reaction by-products observed.

  17. 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.

  18. Latent Heat in Soil Heat Flux Measurements

    USDA-ARS?s Scientific Manuscript database

    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. 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.

  20. 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.

  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. Data Release Summary Statement

    Atmospheric Science Data Center

    2016-11-14

    ... 3 CALIOP Level 1 data are released with a product maturity classification of Validated Stage1 , indicating that initial validation of ... users for evaluation and to provide feedback to the CALIOP algorithm development team. Users should carefully read the section of the Data ...

  3. 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...

  4. Release of OLe peanut

    USDA-ARS?s Scientific Manuscript database

    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...

  5. NASTRAN: April 1982 Release

    NASA Technical Reports Server (NTRS)

    Brugh, R. L.

    1982-01-01

    Latest public release of NASTRAN, April 1982 most efficient and versatile to date. Intended range of applications of NASTRAN includes almost every kind of structure and construction. Users may develop their own analysis capabilities by using Direct Matrix Abstraction Programming (DMAP) language to direct NASTRAN in solution of general matrix problems.

  6. 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…

  7. Hydraulic release oil tool

    SciTech Connect

    Mims, M.G.; Mueller, M.D.; Ehlinger, J.C.

    1992-03-11

    This patent describes a hydraulic release tool. It comprises a setting assembly; a coupling member for coupling to drill string or petroleum production components, the coupling member being a plurality of sockets for receiving the dogs in the extended position and attaching the coupling member the setting assembly; whereby the setting assembly couples to the coupling member by engagement of the dogs in the sockets of releases from and disengages the coupling member in movement of the piston from its setting to its reposition in response to a pressure in the body in exceeding the predetermined pressure; and a relief port from outside the body into its bore and means to prevent communication between the relief port and the bore of the body axially of the piston when the piston is in the setting position and to establish such communication upon movement of the piston from the setting position to the release position and reduce the pressure in the body bore axially of the piston, whereby the reduction of the pressure signals that the tool has released the coupling member.

  8. 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...

  9. Trigger release liposome systems: local and remote controlled delivery?

    PubMed

    Bibi, Sagida; Lattmann, E; Mohammed, Afzal R; Perrie, Yvonne

    2012-01-01

    Target-specific delivery has become an integral area of research in order to increase bioavailability and reduce the toxic effects of drugs. As a drug-delivery option, trigger-release liposomes offer sophisticated targeting and greater control-release capabilities. These are broadly divided into two categories; those that utilise the local environment of the target site where there may be an upregulation in certain enzymes or a change in pH and those liposomes that are triggered by an external physical stimulus such as heat, ultrasound or light. These release mechanisms offer a greater degree of control over when and where the drug is released; furthermore, targeting of diseased tissue is enhanced by incorporation of target-specific components such as antibodies. This review aims to show the development of such trigger release liposome systems and the current research in this field.

  10. Release behavior of tritium from graphite heavily irradiated by neutrons

    NASA Astrophysics Data System (ADS)

    Saeki, Masakatsu

    1981-07-01

    The release behavior of tritium formed in graphite has been investigated as a function of radiation damage by means of isochronal annealing of samples heavily irradiated by neutrons. The lithium impurities in graphite were estimated as the source of tritium formation. The main chemical form of released tritium was hydrogen accompanied by a small quantity of methane. No other hydrocarbons could be detected. Tritiated water was always measured, but the formation mechanism was experimentally confirmed as the secondary oxidation of released HT molecule. The release spectrum of tritium in isochronal annealing was shifted to a higher heating temperature with the increase of the neutron fluence received by the graphite crystal. A relationship was established between the amount of tritium released up to a certain temperature and the degree of graphitization of the sample.

  11. Energy release in braided coronal loops

    NASA Astrophysics Data System (ADS)

    Pontin, David; Hornig, Gunnar; Galsgaard, Klaus; Candelaresi, Simon

    2017-04-01

    I will examine the dynamics of solar coronal loops containing non-trivial magnetic field line braiding, in the context of Parker's braiding mechanism for coronal heating. The existence of braided force-free equilibria will be discussed, including a demonstration that these equilibria must contain current layers whose thickness deceases for increasing field complexity. The implication for the corona is that if one considers a line-tied coronal loop that is driven by photospheric motions, then the eventual onset of reconnection and energy release is inevitable. Once the initial reconnection event is triggered a turbulent relaxation ensues. The properties of this relaxation will be discussed, together with the expected observational signatures of energy release in such a braided coronal loop.

  12. Heat transfer characteristics of building walls using phase change material

    NASA Astrophysics Data System (ADS)

    Irsyad, M.; Pasek, A. D.; Indartono, Y. S.; Pratomo, A. W.

    2017-03-01

    Minimizing energy consumption in air conditioning system can be done with reducing the cooling load in a room. Heat from solar radiation which passes through the wall increases the cooling load. Utilization of phase change material on walls is expected to decrease the heat rate by storing energy when the phase change process takes place. The stored energy is released when the ambient temperature is low. Temperature differences at noon and evening can be utilized as discharging and charging cycles. This study examines the characteristics of heat transfer in walls using phase change material (PCM) in the form of encapsulation and using the sleeve as well. Heat transfer of bricks containing encapsulated PCM, tested the storage and released the heat on the walls of the building models were evaluated in this study. Experiments of heat transfer on brick consist of time that is needed for heat transfer and thermal conductivity test as well. Experiments were conducted on a wall coated by PCM which was exposed on a day and night cycle to analyze the heat storage and heat release. PCM used in these experiments was coconut oil. The measured parameter is the temperature at some points in the brick, walls and ambient temperature as well. The results showed that the use of encapsulation on an empty brick can increase the time for thermal heat transfer. Thermal conductivity values of a brick containing encapsulated PCM was lower than hollow bricks, where each value was 1.3 W/m.K and 1.6 W/m.K. While the process of heat absorption takes place from 7:00 am to 06:00 pm, and the release of heat runs from 10:00 pm to 7:00 am. The use of this PCM layer can reduce the surface temperature of the walls of an average of 2°C and slows the heat into the room.

  13. Direct expansion solar collector and heat pump

    NASA Astrophysics Data System (ADS)

    1982-05-01

    A hybrid heat pump/solar collector combination in which solar collectors replace the outside air heat exchanger found in conventional air-to-air heat pump systems is discussed. The solar panels ordinarily operate at or below ambient temperature, eliminating the need to install the collector panels in a glazed and insulated enclosure. The collectors simply consist of a flat plate with a centrally located tube running longitudinally. Solar energy absorbed by exposed panels directly vaporizes the refrigerant fluid. The resulting vapor is compressed to higher temperature and pressure; then, it is condensed to release the heat absorbed during the vaporization process. Control and monitoring of the demonstration system are addressed, and the tests conducted with the demonstration system are described. The entire heat pump system is modelled, including predicted performance and costs, and economic comparisons are made with conventional flat-plate collector systems.

  14. 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.

  15. 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

  16. Silicate release from glass for pharmaceutical preparations.

    PubMed

    Bohrer, Denise; Bortoluzzi, Fabiana; Nascimento, Paulo Cícero; Carvalho, Leandro Machado; Ramirez, Adrian Gustavo

    2008-05-01

    Glass is made of polymeric silica and other minor components, which are necessary for turning the silica into a material more easily moldable and resistant to temperature changes. Glass containers for pharmaceutical usage are classified according to their resistance to a chemical attack, a test carried out in the presence of water and heat. The test is designed to show the released alkalinity, a variable dependent on the amount of sodium oxide, one of the minor components added to the glass mass. In this work, the release of silica from glass by action of constituents from pharmaceutical formulations was investigated. The study included products used in large volumes and usually stored in glass containers. Solutions of amino acids, electrolytes, glucose, oligoelements and others such as heparin and sodium bicarbonate were individually stored in glass containers and heated at 121 degrees C for 30min, as in the water attack test. The test was also carried out only with water, where the pH varied from 2 to 12. The released silicate was measured either by photometry or atomic absorption spectrometry, depending on the nature of the sample. The results showed that silicate is released during the heating cycle even if the contact is with pure water only. The pH exerts a considerable influence on the release, being that the higher the pH, the higher the silica dissolved. An elevated pH, however, is not the only factor responsible for silica dissolution. While in the solutions of NaCl, KCl, Mg Cl2 and ZnSO4 and in most of the amino acids, the concentration of silicate was as high as in pure water (0.1-1.0mg Si/L). In the solutions of sodium acetate, bicarbonate and gluconate, its concentration was much higher, over 30mg Si/L. These results were confirmed by the analysis of commercial products, where in solutions of amino acids the level of silicate ranged from 0.14 to 0.19mg Si/L. On the other hand, calcium gluconate, sodium bicarbonate and potassium phosphate presented

  17. Metabolic heat production by human and animal populations in cities

    NASA Astrophysics Data System (ADS)

    Stewart, Iain D.; Kennedy, Chris A.

    2016-12-01

    Anthropogenic heating from building energy use, vehicle fuel consumption, and human metabolism is a key term in the urban energy budget equation. Heating from human metabolism, however, is often excluded from urban energy budgets because it is widely observed to be negligible. Few reports for low-latitude cities are available to support this observation, and no reports exist on the contribution of domestic animals to urban heat budgets. To provide a more comprehensive view of metabolic heating in cities, we quantified all terms of the anthropogenic heat budget at metropolitan scale for the world's 26 largest cities, using a top-down statistical approach. Results show that metabolic heat release from human populations in mid-latitude cities (e.g. London, Tokyo, New York) accounts for 4-8% of annual anthropogenic heating, compared to 10-45% in high-density tropical cities (e.g. Cairo, Dhaka, Kolkata). Heat release from animal populations amounts to <1% of anthropogenic heating in all cities. Heat flux density from human and animal metabolism combined is highest in Mumbai—the world's most densely populated megacity—at 6.5 W m-2, surpassing heat production by electricity use in buildings (5.8 W m-2) and fuel combustion in vehicles (3.9 W m-2). These findings, along with recent output from global climate models, suggest that in the world's largest and most crowded cities, heat emissions from human metabolism alone can force measurable change in mean annual temperature at regional scale.

  18. Metabolic heat production by human and animal populations in cities

    NASA Astrophysics Data System (ADS)

    Stewart, Iain D.; Kennedy, Chris A.

    2017-07-01

    Anthropogenic heating from building energy use, vehicle fuel consumption, and human metabolism is a key term in the urban energy budget equation. Heating from human metabolism, however, is often excluded from urban energy budgets because it is widely observed to be negligible. Few reports for low-latitude cities are available to support this observation, and no reports exist on the contribution of domestic animals to urban heat budgets. To provide a more comprehensive view of metabolic heating in cities, we quantified all terms of the anthropogenic heat budget at metropolitan scale for the world's 26 largest cities, using a top-down statistical approach. Results show that metabolic heat release from human populations in mid-latitude cities (e.g. London, Tokyo, New York) accounts for 4-8% of annual anthropogenic heating, compared to 10-45% in high-density tropical cities (e.g. Cairo, Dhaka, Kolkata). Heat release from animal populations amounts to <1% of anthropogenic heating in all cities. Heat flux density from human and animal metabolism combined is highest in Mumbai—the world's most densely populated megacity—at 6.5 W m-2, surpassing heat production by electricity use in buildings (5.8 W m-2) and fuel combustion in vehicles (3.9 W m-2). These findings, along with recent output from global climate models, suggest that in the world's largest and most crowded cities, heat emissions from human metabolism alone can force measurable change in mean annual temperature at regional scale.

  19. Handbook on heat exchangers

    NASA Astrophysics Data System (ADS)

    Bazhan, Pavel I.; Kanevets, Georgii E.; Seliverstov, Vladimir M.

    Essential data on heat exchange equipment used in ship, locomotive, automotive, and aircraft powerplants are presented in a systematic manner. The data cover the principal types and technical and performance characteristics of heat exchangers, fundamentals of the theory of heat exchange, calculation of heat transfer coefficients for different types of heat exchange apparatus, optimization of heat exchangers, computer-aided design of heat exchange equipment, testing techniques, and test result processing.

  20. 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.

  1. 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.

  2. Charring rate of wood exposed to a constant heat flux

    Treesearch

    R. H. White; H. C. Tran

    1996-01-01

    A critical factor in the fire endurance of a wood member is its rate of charring. Most available charring rate data have been obtained using the time-temperature curves of the standard fire resistance tests (ASTM E 119 and ISO 834) to define the fire exposure. The increased use of heat release calorimeters using exposures of constant heat flux levels has broadened the...

  3. 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.

  4. 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.

  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. 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.

  8. Sudden releases of gases

    NASA Astrophysics Data System (ADS)

    Chaloupecká, Hana; Jaňour, Zbyněk; Jurčáková, Klára; Kukačka, Libor; Nosek, Štěpán

    2014-03-01

    Conurbations all over the world have enlarged for numberless years. The accidental or intentional releases of gases become more frequent. Therefore, these crises situations have to be studied. The aim of this paper is to describe experiments examining these processes that were carried out in the laboratory of Environmental Aerodynamics of the Institute of Thermomechanics AS CR in Nový Knín. Results show huge puff variability from replica to replica.

  9. 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.

  10. 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.

  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. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  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. 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.

  20. [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.

  1. Applications of Infrared Thermography in Convective Heat Transfer.

    DTIC Science & Technology

    1986-03-01

    INFRARED THERMOGRAPHY IN CONVECTIVE HEAT TRANSFER by Timothy M. SpenceVX March 1986 Thesis Advisor: R.H. Nunn Approved for public release...Include Security Classfication) APPLICATIONS OF INFRARED THERMOGRAPHY IN CONVECTIVE HEAT TRANSFER !2 PERSONAL AUTHOR(S) Spence, Timothy M. 𔃽a TYPE...I18 SUBJECT TERMS (Continue on reverse if necessary and identify by block number) P:ELD GROUP SUB-GROUP Infrared Thermography ; TVC Convective Heat

  2. Heat powered refrigeration compressor

    NASA Astrophysics Data System (ADS)

    Goad, R. R.

    This prototype will be of similar capacity as the compressor that will eventually be commercially produced. This unit can operate on almost any moderate temperature water heat source. This heat source could include such applications as industrial waste heat, solar, wood burning stove, resistance electrical heat produced by a windmill, or even perhaps heat put out by the condenser of another refrigeration system.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. Recommended for release on recognizance: factors affecting pretrial release recommendations.

    PubMed

    Petee, T A

    1994-06-01

    Researchers have acknowledged the influence of pretrial release agencies in judicial decision making regarding bail; however, few researchers have focused on the process used by the pretrial release agencies to make bail-bond recommendations. In this study I sought to establish which factors were most salient in making the decision to recommend a defendant for release on recognizance. I found that both officially sanctioned release criteria and "extralegal" variables were predictive of this decision.

  8. Sustained-release, extended-release, and other time-release formulations in neuropsychiatry.

    PubMed

    Andrade, Chittaranjan

    2015-08-01

    Pills and capsules may release their contents within minutes of ingestion; these are immediate-release formulations. Pills and capsules may also release their contents after a time lag, or a little at a time, or in some other predetermined way; these are time-release formulations. Many drugs in psychiatry have been time-release formulated to reduce their local adverse effects in the gastrointestinal tract, to reduce adverse effects associated with peak blood levels, or to artificially extend their half-life. Time-release formulations are associated with the added advantages of convenience of dosing, improved compliance, and less fluctuation in blood levels across the course of the day. A disadvantage of time-release formulations is that they may be incompletely absorbed; this is a serious issue in patients with acute or chronic intestinal hurry disorders, such as gastroenteritis or irritable bowel syndrome. Time-release formulations may also be more expensive than immediate-release formulations.

  9. 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.

  10. Energy Corner: Heat Reclamation Rescues Wasted Heat.

    ERIC Educational Resources Information Center

    Daugherty, Thomas

    1982-01-01

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

  11. Energy Corner: Heat Reclamation Rescues Wasted Heat.

    ERIC Educational Resources Information Center

    Daugherty, Thomas

    1982-01-01

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

  12. Identification of coronal heating events in 3D simulations

    NASA Astrophysics Data System (ADS)

    Kanella, Charalambos; Gudiksen, Boris V.

    2017-07-01

    Context. The solar coronal heating problem has been an open question in the science community since 1939. One of the proposed models for the transport and release of mechanical energy generated in the sub-photospheric layers and photosphere is the magnetic reconnection model that incorporates Ohmic heating, which releases a part of the energy stored in the magnetic field. In this model many unresolved flaring events occur in the solar corona, releasing enough energy to heat the corona. Aims: The problem with the verification and quantification of this model is that we cannot resolve small scale events due to limitations of the current observational instrumentation. Flaring events have scaling behavior extending from large X-class flares down to the so far unobserved nanoflares. Histograms of observable characteristics of flares show powerlaw behavior for energy release rate, size, and total energy. Depending on the powerlaw index of the energy release, nanoflares might be an important candidate for coronal heating; we seek to find that index. Methods: In this paper we employ a numerical three-dimensional (3D)-magnetohydrodynamic (MHD) simulation produced by the numerical code Bifrost, which enables us to look into smaller structures, and a new technique to identify the 3D heating events at a specific instant. The quantity we explore is the Joule heating, a term calculated directly by the code, which is explicitly correlated with the magnetic reconnection because it depends on the curl of the magnetic field. Results: We are able to identify 4136 events in a volume 24 × 24 × 9.5 Mm3 (i.e., 768 × 786 × 331 grid cells) of a specific snapshot. We find a powerlaw slope of the released energy per second equal to αP = 1.5 ± 0.02, and two powerlaw slopes of the identified volume equal to αV = 1.53 ± 0.03 and αV = 2.53 ± 0.22. The identified energy events do not represent all the released energy, but of the identified events, the total energy of the largest events

  13. 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.

  14. 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.

  15. 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. ❏ ...

  16. Extreme Heat Guidebook

    EPA Pesticide Factsheets

    The 'Climate Change and Extreme Heat: What You Can Do to Prepare' handbook explains the connection between climate change and extreme heat events, and outlines actions citizens can take to protect their health during extreme heat.

  17. 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 ...

  18. 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.

  19. 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.

  20. Thermal Release of Gases in Achondrites: 1. Gas Release During Melting of Eucrites

    NASA Astrophysics Data System (ADS)

    Assonov, S. S.; Ivanova, M. A.; Shukolyukov, Yu. A.

    1995-09-01

    We previously studied Ar, Kr and Xe during stepwise heating of a sample of the eucrite Pomozdino [1], with temperature steps 400, 600, 800, 900, 1100, 1300 and 1600 C. Most (96%) of the cosmogenic and fissiogenic Xe was released in the 1100 - 1600 C fractions, with maximum release (70%) in the 1300 C fraction. The relative release of these components in the fractions was nearly identical. The fissiongenic Xe release curve is shown in Fig. 1 lower part (construction technique is discussed in part 2). The release curves of all isotopes formed in situ have a peak release in the 1300 C fraction too. The existence of this common peak for different isotopes suggests either the same release process or that the different isotopes were present in the same mineral phase. The rock-forming minerals of eucrites are plagioclase and pyroxenes. Investigation of the Sm-Nd system in the eucrite Pomozdino [2] demonstrated the nearness of the concentrations of Nd in both plagioclase and pyroxene fractions (3.34 and 2.89 nmol/g respectively). Thus the concentrations of both cosmogenic and fissiogenic Xe should be approximately equal in these minerals, and the presence of a single release peak might indicate the destruction of the crystal structure of both minerals, possibly during melting of eucrite under laboratory conditions. In order to evaluate the interval of the Pomozdino eucrite's melting temperatures we used a thermodynamic model of equilibrium crystallization of lunar magmas embodied in the LUNAMAG computer program [3] (and references in this work). The similar compositions of eucrites and lunar rocks, and also the vacuum conditions of the experiment (low fO2) make the model applicable. Fig. 1 (upper part) shows a LUNAMAG graph of equilibrium crystallization using the Pomozdino eucrite [4] chemical composition. The melting temperature of minerals during stepwise heating may be higher than the calculated values due to incomplete solid-melt equilibrium during the temperature

  1. Hydrogen release behavior.

    SciTech Connect

    LaChance, Jeffrey L.; Dedrick, Daniel E.; Keller, Jay O.; Evans, Gregory Herbert; Houf, William G.; Winters, William Stanley, Jr.; Ruggles, A.; Zhang, J.

    2010-04-01

    The summary of this presentation is: (1) Barrier walls are used to reduce setbacks by factor of 2; (2) We found no ignition-timing vs. over-pressure sensitivities for jet flow obstructed by barrier walls; (3) Cryogenic vapor cloud model indicates hazard length scales exceed the room-temperature release; validation experiments are required to confirm; (4) Light-up maps developed for lean limit ignition; flammability factor model provides good indication of ignition probability; and (5) Auto-ignition is enhanced by blunt-body obstructions - increases gas temperature and promotes fuel/air mixing.

  2. 75 FR 8970 - Guidance for Industry on Submission of Documentation in Applications for Parametric Release of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-26

    ... Applications for Parametric Release of Human and Veterinary Drug Products Terminally Sterilized by Moist Heat... ``Submission of Documentation in Applications for Parametric Release of Human and Veterinary Drug Products.... 2201, Silver Spring, MD 20993-0002; the Communications Staff (HFV-12), Center for Veterinary...

  3. Infrared laser triggered release of bioactive compounds from single hard shell microcapsules.

    PubMed

    Vöpel, Tobias; Scholz, Rebecca; Davico, Luca; Gross, Magdalena; Büning, Steffen; Kareth, Sabine; Weidner, Eckhard; Ebbinghaus, Simon

    2015-04-25

    Micro composites are commonly characterized in bulk. Here we study the temperature triggered release of a bioactive compound from single isolated microcapsules. We monitor the release process in real-time using a novel thermal microscopy method combining laser-induced heating and fluorescence imaging.

  4. Heat pump systems

    SciTech Connect

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

    1983-01-01

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

  5. 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.

  6. 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.

  7. Temperature-independent evanescent wave sensor made of a stress-released silica optical fiber taper

    NASA Astrophysics Data System (ADS)

    He, Yongxi; Li, Yingguang; Li, Nanya

    2017-07-01

    Based on a cyclic heating-cooling treatment method, a temperature-independent silica optical fiber evanescent wave sensor is proposed. The cyclic heating-cooling treatment process could significantly release the residual stresses in the taper, achieving a high measurement accuracy in the temperature range of 20-200 °C. After the treatment, the relative light intensity

  8. 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

  9. 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.

  10. 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.

  11. Highlights of the study of energy release in flares

    NASA Technical Reports Server (NTRS)

    Rust, D. M.; Batchelor, D. A.

    1987-01-01

    From February 26 to March 1, 1979, 32 solar flare investigators attended a workshop at Cambridge, MA to define objectives and devise a scientific program for the study of energy release in flares (SERF) during the coming solar maximum. Herein, some major results of the ensuing five-year effort to observe and understand the flare energy release process and its effects (energetic particle production, coronal and chromospheric heating, electromagnetic radiations, and mass motions and ejections) are reviewed. The central issue - what processes store and release the energy liberated in flares - remains unresolved except in the most general terms (e.g., it is generally agreed that the energy is stored in sheared or stressed magnetic fields and released by field annihilation during some MHD instability). Resolving that issue is still one of the most important goals in solar physics, but the advances during the SERF program have brought it closer.

  12. 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.

  13. Human adipocytes secrete mineralocorticoid-releasing factors.

    PubMed

    Ehrhart-Bornstein, M; Lamounier-Zepter, V; Schraven, A; Langenbach, J; Willenberg, H S; Barthel, A; Hauner, H; McCann, S M; Scherbaum, W A; Bornstein, S R

    2003-11-25

    Obesity has become an epidemic problem in western societies, contributing to metabolic diseases, hypertension, and cardiovascular disease. Overweight and obesity are frequently associated with increased plasma levels of aldosterone. Recent evidence suggests that human fat is a highly active endocrine tissue. Therefore, we tested the hypothesis that adipocyte secretory products directly stimulate adrenocortical aldosterone secretion. Secretory products from isolated human adipocytes strongly stimulated steroidogenesis in human adrenocortical cells (NCI-H295R) with a predominant effect on mineralocorticoid secretion. Aldosterone secretion increased 7-fold during 24 h of incubation. This stimulation was comparable to maximal stimulation of these cells with forskolin (2 x 10(-5) M). On the molecular level, there was a 10-fold increase in the expression of steroid acute regulatory peptide mRNA. This effect was independent of adipose angiotensin II as revealed by the stimulatory effect of fat cell-conditioned medium even in the presence of the angiotensin type 1 receptor antagonist, valsartan. None of the recently defined adipocytokines accounted for the effect. Mineralocorticoid-stimulating activity was heat sensitive and could be blunted by heating fat cell-conditioned medium to 99 degrees C. Centrifugal filtration based on molecular mass revealed at least two releasing factors: a heat sensitive fraction (molecular mass >50 kDa) representing 60% of total activity, and an inactive fraction (molecular mass <50 kDa). However, the recovery rate increased to 92% when combining these two fractions, indicating the interaction of at least two factors. In conclusion, human adipocytes secrete potent mineralocorticoid-releasing factors, suggesting a direct link between obesity and hypertension.

  14. Decay heat uncertainty quantification of MYRRHA

    NASA Astrophysics Data System (ADS)

    Fiorito, Luca; Buss, Oliver; Hoefer, Axel; Stankovskiy, Alexey; Eynde, Gert Van den

    2017-09-01

    MYRRHA is a lead-bismuth cooled MOX-fueled accelerator driven system (ADS) currently in the design phase at SCK·CEN in Belgium. The correct evaluation of the decay heat and of its uncertainty level is very important for the safety demonstration of the reactor. In the first part of this work we assessed the decay heat released by the MYRRHA core using the ALEPH-2 burnup code. The second part of the study focused on the nuclear data uncertainty and covariance propagation to the MYRRHA decay heat. Radioactive decay data, independent fission yield and cross section uncertainties/covariances were propagated using two nuclear data sampling codes, namely NUDUNA and SANDY. According to the results, 238U cross sections and fission yield data are the largest contributors to the MYRRHA decay heat uncertainty. The calculated uncertainty values are deemed acceptable from the safety point of view as they are well within the available regulatory limits.

  15. [Compound erythromycin sustained release preparation and its in vitro release].

    PubMed

    Chen, Hai-xia; Chen, Zhi-peng; Wang, Qi-rong; Liu, Ze-kun; Ma, Quan-long

    2011-11-01

    Using the weight-average molecular weight 50 000 polylactic acid (PLA) as a carrier, and a certain proportion of erythromycin (EM) and prednisone acetate (PNA) to mixed prepare the compound erythromycin sustained release preparation (sustained-release tablets). Using ultraviolet spectrophotometry and high performance liquid chromatography (HPLC) to detect separately the release amount of EM and PNA in vitro medium. The sustained-release tablets release for about 21 days, the average content of EM is 99.7 mg/table, RSD = 0.82%; and the average content of PNA is 10.03 mg/table, RSD = 0.93%. Within 21 days, the cumulative releases of EM and PNA are 86.1% and 78.3%, respectively. The drug release is steady and slow after 5 days, the burst release phenomenon in early stage is more significant. The results showed that the sustained-release tablet preparation method is feasible, the release performance is good and the clinical efficacy is significant.

  16. 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.

  17. Skeletal Muscle and Lymphocyte Mitochondrial Dysfunctions in Septic Shock Trigger ICU-Acquired Weakness and Sepsis-Induced Immunoparalysis

    PubMed Central

    Maestraggi, Quentin; Lebas, Benjamin; Clere-Jehl, Raphaël; Ludes, Pierre-Olivier; Schneider, Francis; Diemunsch, Pierre; Geny, Bernard

    2017-01-01

    Fundamental events driving the pathological processes of septic shock-induced multiorgan failure (MOF) at the cellular and subcellular levels remain debated. Emerging data implicate mitochondrial dysfunction as a critical factor in the pathogenesis of sepsis-associated MOF. If macrocirculatory and microcirculatory dysfunctions undoubtedly participate in organ dysfunction at the early stage of septic shock, an intrinsic bioenergetic failure, sometimes called “cytopathic hypoxia,” perpetuates cellular dysfunction. Short-term failure of vital organs immediately threatens patient survival but long-term recovery is also severely hindered by persistent dysfunction of organs traditionally described as nonvital, such as skeletal muscle and peripheral blood mononuclear cells (PBMCs). In this review, we will stress how and why a persistent mitochondrial dysfunction in skeletal muscles and PBMC could impair survival in patients who overcome the first acute phase of their septic episode. First, muscle wasting protracts weaning from mechanical ventilation, increases the risk of mechanical ventilator-associated pneumonia, and creates a state of ICU-acquired muscle weakness, compelling the patient to bed. Second, failure of the immune system (“immunoparalysis”) translates into its inability to clear infectious foci and predisposes the patient to recurrent nosocomial infections. We will finally emphasize how mitochondrial-targeted therapies could represent a realistic strategy to promote long-term recovery after sepsis. PMID:28589148

  18. Skeletal Muscle and Lymphocyte Mitochondrial Dysfunctions in Septic Shock Trigger ICU-Acquired Weakness and Sepsis-Induced Immunoparalysis.

    PubMed

    Maestraggi, Quentin; Lebas, Benjamin; Clere-Jehl, Raphaël; Ludes, Pierre-Olivier; Chamaraux-Tran, Thiên-Nga; Schneider, Francis; Diemunsch, Pierre; Geny, Bernard; Pottecher, Julien

    2017-01-01

    Fundamental events driving the pathological processes of septic shock-induced multiorgan failure (MOF) at the cellular and subcellular levels remain debated. Emerging data implicate mitochondrial dysfunction as a critical factor in the pathogenesis of sepsis-associated MOF. If macrocirculatory and microcirculatory dysfunctions undoubtedly participate in organ dysfunction at the early stage of septic shock, an intrinsic bioenergetic failure, sometimes called "cytopathic hypoxia," perpetuates cellular dysfunction. Short-term failure of vital organs immediately threatens patient survival but long-term recovery is also severely hindered by persistent dysfunction of organs traditionally described as nonvital, such as skeletal muscle and peripheral blood mononuclear cells (PBMCs). In this review, we will stress how and why a persistent mitochondrial dysfunction in skeletal muscles and PBMC could impair survival in patients who overcome the first acute phase of their septic episode. First, muscle wasting protracts weaning from mechanical ventilation, increases the risk of mechanical ventilator-associated pneumonia, and creates a state of ICU-acquired muscle weakness, compelling the patient to bed. Second, failure of the immune system ("immunoparalysis") translates into its inability to clear infectious foci and predisposes the patient to recurrent nosocomial infections. We will finally emphasize how mitochondrial-targeted therapies could represent a realistic strategy to promote long-term recovery after sepsis.

  19. Phase change dispersion, potentially a new class of heat transfer fluids

    NASA Astrophysics Data System (ADS)

    Fischer, L. J.; von Arx, S.; Wechsler, U.; Züst, S.; Worlitschek, J.

    2016-09-01

    The authors present values and an application of a phase change dispersion, where the dispersed phase change material within water changes from solid to liquid while absorbing heat and changes from liquid to solid while releasing heat at constant temperature. The phase change enthalpy increases the “apparent specific heat capacity” significantly in comparison to water. As the heat transfer takes place at constant temperature, the heat transfer fluid itself remains at constant temperature while absorbing heat. Isothermal heating and cooling of devices with a liquid is feasible.

  20. 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.

  1. SITELLE's Data Release 1

    NASA Astrophysics Data System (ADS)

    Martin, T. B.; Drissen, L.

    2016-12-01

    Installed at the Canada-France-Hawaii Telescope (CFHT) since August 2015, SITELLE is an Imaging Fourier Transform Spectrometer (IFTS) with an 11×11 field of view. After its prototype SpIOMM, installed at Mont Mégantic (Québec, Canada), it is the second IFTS in the world operating in the visible band (350-1000 nm). It delivers hyperspectral data cubes of 4 million spectra at R˜1500-5000 with a spatial sampling of 0.32" and a filling factor of 100 %. A suite of softwares has been designed to reduce (ORBS) and analyze (ORCS) the data. Based on commissioning data obtained in August 2015, a first stable version has been released in March 2016 which is capable of reducing all the data. In this paper the quality of the calibration is discussed.

  2. 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.

  3. Draft Wetlands Rule Released

    NASA Astrophysics Data System (ADS)

    Zielinski, Sarah

    2006-04-01

    The U.S. Environmental Protection Agency (EPA) and the U.S. Army Corps of Engineers released on 28 March a draft of a new rule to guide compensatory mitigation for when wetlands are unavoidably lost due to development. However, whether the rule is successful in preventing a net loss in wetlands will depend largely on its implementation, according to two wetlands scientists who evaluated the issue for the U.S. National Research Council (NRC) in 2001. Under the federal Clean Water Act, developers who seek to build on wetlands must compensate for any wetlands loss if they are unable to avoid or minimize the loss. Such compensation is covered under the newly proposed compensatory mitigation rule. Benjamin Grumbles, EPA assistant administrator for water, called the rule an ``innovative new standard that will accelerate the pace of wetlands conservation and restoration.''

  4. [Drug release system controlled by near infrared light].

    PubMed

    Niidome, Takuro

    2013-01-01

    Gold nanorods have absorption bands in the near-infrared region; in this spectral range, light penetrates deeply into tissues. The absorbed light energy is converted into heat by gold nanorods. This is the so-called photothermal effect. Gold nanorods are therefore expected to act not only as thermal converters for photothermal therapy, but also as controllers for drug-release systems responding to irradiation with near-infrared light. To achieve a controlled-release system that could be triggered by light irradiation, the gold nanorods were modified with double-stranded DNA (dsDNA). When the dsDNA-modified gold nanorods were irradiated with near-infrared light, single-stranded DNA (ssDNA) was released from the gold nanorods because of the photothermal effect. The release of ssDNA was also observed in tumors grown on mice after near-infrared light irradiation. We also proposed a different controlled-release system responding to near-infrared light. Gold nanorods were modified with polyethylene glycol (PEG) through Diels-Alder cycloadducts. When the gold nanorods were irradiated with near-infrared light, the PEG chains were released from the gold nanorods because of the retro Diels-Alder reaction induced by the photothermal effect. Such controlled-release systems triggered by near-infrared light irradiation will be expanded for gold nanorod drug delivery system applications.

  5. Direct fired heat exchanger

    DOEpatents

    Reimann, Robert C.; Root, Richard A.

    1986-01-01

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

  6. 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.

  7. 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.

  8. Woven heat exchanger

    DOEpatents

    Piscitella, Roger R.

    1987-01-01

    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.

  9. 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)

  10. Solar heat pump

    NASA Astrophysics Data System (ADS)

    Hermanson, R.

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

  11. 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)

  12. 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…

  13. 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…

  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. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. Integrated heat pump system

    SciTech Connect

    Reedy, W.R.

    1988-03-01

    An integrated heat pump and hot water system is described that includes: a heat pump having an indoor heat exchanger and an outdoor heat exchanger that are selectively connected to the suction line and the discharge line respectively of a compressor by a flow reversing means, and to each other by a liquid line having an expansion device mounted therein, whereby heating and cooling is provided to an indoor comfort zone by cycling the flow reversing means, a refrigerant to water heat exchanger having a hot water flow circuit in heat transfer relation with a first refrigerant condensing circuit and a second refrigerant evaporating circuit, a connection mounted in the liquid between the indoor heat exchanger and the expansion device, control means for regulating the flow of refrigerant through the refrigerant to water heat exchanger to selectively transfer heat into and out of the hot water flow circuit.

  2. Industrial heat exchangers

    SciTech Connect

    Hayes, A.J.; Liang, W.W.; Richlen, S.L.; Tabb, E.S.

    1985-01-01

    This book presents the papers given at a symposium on the use of heat exchangers in the industrial plants. Topics considered include the US DOE and GRI research programs, advanced fixed boundary heat exchanger technology, commercial heat exchanger applications, thermo-hydraulic performance of heat-transfer equipment, field tests, the corrosion of heat exchanger materials, economics, cost benefit analysis, payback, and advanced assembly and materials.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. Sunspot waves and flare energy release

    NASA Astrophysics Data System (ADS)

    Sych, R.; Karlický, M.; Altyntsev, A.; Dudík, J.; Kashapova, L.

    2015-05-01

    flare. The flare occurred because of this amplified flux, however, and because a sufficient amount of free magnetic energy was accumulated in close vicinity to the magnetic channel prior to the flare. Furthermore, because of loop heating, the wave velocity (sound velocity) increased with the penetration of waves into the energy release site. The heating is shown to be able to proceed after the flare main peak owing to a further energy pumping in the form of waves from the sunspot and additional reconnection episodes in the flare region.

  9. 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.

  10. 19 CFR 142.41 - Line Release.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... (CONTINUED) ENTRY PROCESS Line Release § 142.41 Line Release. Line Release is an automated system designed to release and tract repetitive shipments. It is a method of entry or immediate delivery extended to...

  11. Heat pump augmentation of nuclear process heat

    SciTech Connect

    Koutz, S.L.

    1986-03-18

    A system is described for increasing the temperature of a working fluid heated by a nuclear reactor. The system consists of: a high temperature gas cooled nuclear reactor having a core and a primary cooling loop through which a coolant is circulated so as to undergo an increase in temperature, a closed secondary loop having a working fluid therein, the cooling and secondary loops having cooperative association with an intermediate heat exchanger adapted to effect transfer of heat from the coolant to the working fluid as the working fluid passes through the intermediate heat exchanger, a heat pump connected in the secondary loop and including a turbine and a compressor through which the working fluid passes so that the working fluid undergoes an increase in temperature as it passes through the compressor, a process loop including a process chamber adapted to receive a process fluid therein, the process chamber being connected in circuit with the secondary loop so as to receive the working fluid from the compressor and transfer heat from the working fluid to the process fluid, a heat exchanger for heating the working fluid connected to the process loop for receiving heat therefrom and for transferring heat to the secondary loop prior to the working fluid passing through the compressor, the secondary loop being operative to pass the working fluid from the process chamber to the turbine so as to effect driving relation thereof, a steam generator operatively associated with the secondary loop so as to receive the working fluid from the turbine, and a steam loop having a feedwater supply and connected in circuit with the steam generator so that feedwater passing through the steam loop is heated by the steam generator, the steam loop being connected in circuit with the process chamber and adapted to pass steam to the process chamber with the process fluid.

  12. Heat Pipe Technology

    NASA Astrophysics Data System (ADS)

    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.

  13. Enhancement of heat transfer

    NASA Astrophysics Data System (ADS)

    Nakayama, W.

    Recent publications on enhancement of heat transfer are reviewed, emphasizing the effects of roughness elements, fins, and porous surfaces. Enhancement of forced convective heat transfer on roughened surfaces, performance evaluation of enhanced surfaces, viscous flows in cooled tubes and tubes with swirlers, and active methods of enhancement are addressed. Aspects of pool boiling heat transfer are considered, including nucleate boiling heat transfer on rough surfaces and porous surfaces, and maximum and minimum heat fluxes. Evaporative heat transfer is discussed for thin-film evaporation on structured surfaces and liquid spray cooling of a heated surface. Condensation heat transfer on external surfaces is covered, including filmwise condensation on vertical finned and fluted surfaces and on horizontal tubes. In-tube boiling and condensation are treated, discussing their enhancement by fins and inserts, as well as critical heat flux in coiled, rifled, and corrugated tubes.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. Flexible Heating Head

    NASA Technical Reports Server (NTRS)

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

    1994-01-01

    United States Air Force is investigating method of repairing aircraft by use of adhesive bonding with induction heating to cure adhesive. Fast-acting and reliable induction heating device that is lightweight, portable, and easy to use needed for such applications. Newly developed flexible heating head lightweight and conforms to complex, curved surfaces. Incorporates principles and circuitry of toroid joining gun described in "Toroid Joining Gun for Fittings and Couplings" (LAR-14278). Concentrates heat in local area through induction heating. Flexible heating head contains tank circuit, connected via cable to source of power.

  19. Flexible Heating Head

    NASA Technical Reports Server (NTRS)

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

    1994-01-01

    United States Air Force is investigating method of repairing aircraft by use of adhesive bonding with induction heating to cure adhesive. Fast-acting and reliable induction heating device that is lightweight, portable, and easy to use needed for such applications. Newly developed flexible heating head lightweight and conforms to complex, curved surfaces. Incorporates principles and circuitry of toroid joining gun described in "Toroid Joining Gun for Fittings and Couplings" (LAR-14278). Concentrates heat in local area through induction heating. Flexible heating head contains tank circuit, connected via cable to source of power.

  20. 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.

  1. 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

  2. Influence of the Thomson effect on the pulse heating of high-current electrical contacts

    NASA Astrophysics Data System (ADS)

    Merkushev, A. G.; Pavleino, M. A.; Pavleino, O. M.; Pavlov, V. A.

    2014-09-01

    Pulse heating of high-current contacts is notable for the presence of considerable temperature gradients in the contact area, which cause the Thomson effect—the appearance of thermoelectric currents. The amount of this effect against conventional Joule heat release is quantitatively estimated. Pulse heating of electrical contacts is numerically simulated with the use of the Comsol program package. It is demonstrated that thermoelectric currents make a negligible contribution to heating in the case of copper contacts.

  3. 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.

  4. 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

  5. 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)

  6. 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)

  7. Slow-release fertilizers 101

    Treesearch

    Robin Rose

    2002-01-01

    Slow release fertilizers have been in common use within the horticultural industry for decades. Probably the mostly commonly heard of product is Scott's Osmocote which has been around for a quite a long time. However, some time ago slow release fertilizers moved out of the potted greenhouse environment and onto golf courses, suburban lawns and bushes, and orchards...

  8. Nonstationary Heat Conduction in Atomic Systems

    NASA Astrophysics Data System (ADS)

    Singh, Amit K.

    Understanding heat at the atomistic level is an interesting exercises. It is fascinating to note how the vibration of atoms result into thermodynamic concept of heat. This thesis aims to bring insights into different constitutive laws of heat conduction. We also develop a framework in which the interaction of thermostats to the system can be studied and a well known Kapitza effect can be reduced. The thesis also explores stochastic and continuum methods to model the latent heat release in the first order transition of ideal silicon surfaces into dimers. We divide the thesis into three works which are connected to each other: 1. Fourier's law leads to a diffusive model of heat transfer in which a thermal signal propagates infinitely fast and the only material parameter is the thermal conductivity. In micro- and nano-scale systems, non-Fourier effects involving coupled diffusion and wavelike propagation of heat can become important. An extension of Fourier's law to account for such effects leads to a Jeffreys-type model for heat transfer with two relaxation times. In this thesis, we first propose a new Thermal Parameter Identification (TPI) method for obtaining the Jeffreys-type thermal parameters from molecular dynamics simulations. The TPI method makes use of a nonlinear regression-based approach for obtaining the coefficients in analytical expressions for cosine and sine-weighted averages of temperature and heat flux over the length of the system. The method is applied to argon nanobeams over a range of temperature and system sizes. The results for thermal conductivity are found to be in good agreement with standard Green-Kubo and direct method calculations. The TPI method is more efficient for systems with high diffusivity and has the advantage, that unlike the direct method, it is free from the influence of thermostats. In addition, the method provides the thermal relaxation times for argon. Using the determined parameters, the Jeffreys-type model is able to

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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).

  14. 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.

  15. Fusion heating technology

    SciTech Connect

    Cole, A.J.

    1982-06-01

    John Lawson established the criterion that in order to produce more energy from fusion than is necessary to heat the plasma and replenish the radiation losses, a minimum value for both the product of plasma density and confinement time t, and the temperature must be achieved. There are two types of plasma heating: neutral beam and electromagnetic wave heating. A neutral beam system is shown. Main development work on negative ion beamlines has focused on the difficult problem of the production of high current sources. The development of a 30 keV-1 ampere multisecond source module is close to being accomplished. In electromagnetic heating, the launcher, which provides the means of coupling the power to the plasma, is most important. The status of heating development is reviewed. Electron cyclotron resonance heating (ECRH), lower hybrid heating (HHH), and ion cyclotron resonance heating (ICRH) are reviewed.

  16. 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

  17. 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.

  18. Magnetic Energy Release in Solar Flares

    NASA Astrophysics Data System (ADS)

    Forbes, Terry G.

    2017-01-01

    Solar flares are the result of a rapid release of magnetic energy stored in the solar corona. An ideal-MHD process, such as a loss of magnetic equilibrium, most likely initiates the flare, but the non-ideal process of magnetic reconnection quickly becomes the dominant mechanism by which energy is released. Within the last few years EUV and X-ray instruments have directly observed the kind of plasma flows and heating indicative of magnetic reconnection. Relatively cool plasma is observed moving slowly into the reconnection region where it is transformed into two high-temperature, high-speed outflow jets moving in opposite directions. Observations of the flow in these jets suggest that they are accelerated to the ambient Alfvén speed in a manner that resembles the reconnection process first proposed by H. E. Petschek in 1964. This result is somewhat surprising because Petschek-type reconnection does not occur in most numerical simulations of magnetic reconnection. The apparent contradiction between the observations and the simulations can be understood by the fact that most simulations assume a uniform resistivity model that is unlikely to occur in reality. Recently, we have developed a theory that shows how the type of reconnection is related to the plasma resistivity. The theory is based on a form of the time-dependent, MHD-nozzle equations that incorporate the plasma resistivity. These equations are very similar to the equations used to describe magnetized plasma flow in astrophysical jets.

  19. Cold Climate Heat Pump

    DTIC Science & Technology

    2013-08-01

    central heating , cooling, and air conditioning (HVAC) system . Both buildings had two zones for heating and cooling, which allowed for a direct...section calls for improved efficiency of mechanical systems as well as an increase of renewable resource usage. Current heating technologies in cold... heated refrigerant is injected into a mixing chamber between the two compressors. The injection leads to a gain in performance of the system through

  20. Compact, super heat exchanger

    NASA Technical Reports Server (NTRS)

    Fortini, A.; Kazaroff, J. M.

    1980-01-01

    Heat exchanger uses porous media to enhance heat transfer through walls of cooling channels, thereby lowering wall temperature. Porous media within cooling channel increases internal surface area from which heat can be transferred to coolant. Comparison data shows wall has lower temperature and coolant has higher temperature when porous medium is used within heat exchanger. Media can be sintered powedered metal, metal fibers, woven wire layers, or any porous metal having desired permeability and porosity.

  1. Compact, super heat exchanger

    NASA Technical Reports Server (NTRS)

    Fortini, A.; Kazaroff, J. M.

    1980-01-01

    Heat exchanger uses porous media to enhance heat transfer through walls of cooling channels, thereby lowering wall temperature. Porous media within cooling channel increases internal surface area from which heat can be transferred to coolant. Comparison data shows wall has lower temperature and coolant has higher temperature when porous medium is used within heat exchanger. Media can be sintered powedered metal, metal fibers, woven wire layers, or any porous metal having desired permeability and porosity.

  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 heat receiver

    DOEpatents

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

    1985-01-01

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

  4. 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.

  5. 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.

  6. 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.

  7. Characteristics of releases from TREAT source term experiment STEP-3

    SciTech Connect

    Fink, J.K.; Schlenger, B.J.; Baker, L. Jr.; Ritzman, R.L.

    1987-01-01

    Four in-pile experiments designed to characterize the radiological source term associated with postulated severe light water reactor accidents were performed at the Transient Reactor Test Facility. STEP-3 simulated a high-pressure TMLB' pressurized water reactor accident sequence that includes the extended loss of all ac power and leads to the loss of long-term decay heat removal. In STEP-3, four fuel elements from the Belgonucleaire BR3 reactor were subjected to temperature and pressures approaching those of a TMLB' accident. A description of the experiment and thermal-hydraulic analysis is reported elsewhere. The aerosols released into the flow stream were collected on coupons, settling plates, and wire impactors. Examination of the collected aerosol deposits was performed using scanning electron microscopy, electron microprobe microanalysis, and secondary ion mass spectroscopy (SIMS), to provide information about the chemical composition and morphology of the release. This paper describes the aerosol deposits and elemental composition of the release.

  8. 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.

  9. 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.

  10. Drug releasing nanoplatforms activated by alternating magnetic fields.

    PubMed

    Mertz, Damien; Sandre, Olivier; Bégin-Colin, Sylvie

    2017-02-24

    The use of an alternating magnetic field (AMF) to generate non-invasively and spatially a localized heating from a magnetic nano-mediator has become very popular these last years to develop magnetic hyperthermia (MH) as a promising therapeutic modality already used in the clinics. AMF has become highly attractive this last decade over others radiations, as AMF allows a deeper penetration in the body and a less harmful ionizing effect. In addition to pure MH which induces tumor cell death through local T elevation, this AMF-generated magneto-thermal effect can also be exploited as a relevant external stimulus to trigger a drug release from drug-loaded magnetic nanocarriers, temporally and spatially. This review article is focused especially on this concept of AMF induced drug release, possibly combined with MH. The design of such magnetically responsive drug delivery nanoplatforms requires two key and complementary components: a magnetic mediator which collects and turns the magnetic energy into local heat, and a thermoresponsive carrier ensuring thermo-induced drug release, as a consequence of magnetic stimulus. A wide panel of magnetic nanomaterials/chemistries and processes are currently developed to achieve such nanoplatforms. This review article presents a broad overview about the fundamental concepts of drug releasing nanoplatforms activated by AMF, their formulations, and their efficiency in vitro and in vivo. This article is part of a Special Issue entitled "Recent Advances in Bionanomaterials" Guest Editors: Dr. Marie-Louise Saboungi and Dr. Samuel D. Bader.

  11. 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.

  12. 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.

  13. 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.

  14. Heat-related illness.

    PubMed

    Atha, Walter F

    2013-11-01

    Environmental exposure to high temperatures can result in abnormalities ranging from mild heat exhaustion to heat stroke with multiorgan system failure. An understanding of the mechanisms of thermoregulation and how those mechanisms fail with extreme heat stress is critical for management of the patient with elevated body temperature in the emergency department.

  15. Heat Recovery System

    NASA Technical Reports Server (NTRS)

    1984-01-01

    Ball Metal's design of ducting and controls for series of roof top heat exchangers was inspired by Tech Briefs. Heat exchangers are installed on eight press and coating lines used to decorate sheet metal. The heat recovery system provides an estimated energy savings of more than $250,000 per year.

  16. 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.

  17. 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.

  18. Electric heating pad burns.

    PubMed

    Bill, T J; Edlich, R F; Himel, H N

    1994-01-01

    Patients with sensory deficits are especially prone to heating pad burns. Two cases are reported of patients with anesthetic skin who received partial and full-thickness burns of their feet from an electric heating pad. These burn injuries could have been prevented if the patients understood the potential hazard of heating pads.

  19. Orion Heat Shield

    NASA Image and Video Library

    2015-05-06

    ENGINEERS FROM AMES RESEARCH CENTER AND MARSHALL SPACE FLIGHT CENTER REMOVE AVCOAT SEGMENTS FROM THE SURFACE OF THE ORION HEAT SHIELD, THE PROTECTIVE SHELL DESIGNED TO HELP THE NEXT GENERATION CREW MODULE WITHSTAND THE HEAT OF ATMOSPHERIC REENTRY. THE HEAT SHIELD FLEW TO SPACE DURING THE EFT-1 FULL SCALL FLIGHT TEST OF ORION IN DECEMBER 2014

  20. 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. © 2011 American Chemical Society

  1. Geothermal heat in a heat pump use

    NASA Astrophysics Data System (ADS)

    Pavlova, A.; Hansen, J.; Obermeyer, H.; Pavlova, I.

    2016-09-01

    The considered innovative technology proposes to use alternative energy sources for the process efficiency in low-height construction. The world economy depends on price rises for energy sources and the danger of environmental pollution increases. Geothermal energy is the basic resource saving and environmentally safe renewable heat source that is characterized by inexhaustibility, permanent all the-year-round use, universal prevalence of resources and the ability to replace considerable volumes of traditional energy carriers. The expediency and power efficiency to apply a heat pump with the use of geothermal heat is proved for low-height construction.

  2. Heat pipes for industrial waste heat recovery

    SciTech Connect

    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 have been investigated. Economic studies of the use of heat-pipe based recuperators in industrial furnaces have been conducted and payback periods determined as a function of material, fabrication, and installation cost.

  3. High heat flux loop heat pipes

    NASA Technical Reports Server (NTRS)

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

    1997-01-01

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

  4. 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

  5. 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

  6. 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.

  7. 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

  8. Toxics Release Inventory indicates big increases in releases

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    2012-01-01

    Nearly 4 billion pounds of tracked toxic chemicals were released into the environment throughout the United States during 2010, according to an analysis by the U.S. Environmental Protection Agency (EPA) of the Toxics Release Inventory (TRI), the agency announced on 5 January. This is a 16% increase above 2009. The agency said the increase is mainly due to changes in the metal-mining sector, where differences in the chemical composition of ore being mined can result in significant changes in the amount of toxic chemicals. The chemical and primary metals industries were other sectors with increases in toxic releases in 2010, the latest year for which data collection is complete. EPA also noted that although releases in 2010 were higher than during the previous 2 years, they were lower than in 2007 and in prior years.

  9. Metabolic heat production by human and animal populations in cities.

    PubMed

    Stewart, Iain D; Kennedy, Chris A

    2016-12-26

    Anthropogenic heating from building energy use, vehicle fuel consumption, and human metabolism is a key term in the urban energy budget equation. Heating from human metabolism, however, is often excluded from urban energy budgets because it is widely observed to be negligible. Few reports for low-latitude cities are available to support this observation, and no reports exist on the contribution of domestic animals to urban heat budgets. To provide a more comprehensive view of metabolic heating in cities, we quantified all terms of the anthropogenic heat budget at metropolitan scale for the world's 26 largest cities, using a top-down statistical approach. Results show that metabolic heat release from human populations in mid-latitude cities (e.g. London, Tokyo, New York) accounts for 4-8% of annual anthropogenic heating, compared to 10-45% in high-density tropical cities (e.g. Cairo, Dhaka, Kolkata). Heat release from animal populations amounts to <1% of anthropogenic heating in all cities. Heat flux density from human and animal metabolism combined is highest in Mumbai-the world's most densely populated megacity-at 6.5 W m(-2), surpassing heat production by electricity use in buildings (5.8 W m(-2)) and fuel combustion in vehicles (3.9 W m(-2)). These findings, along with recent output from global climate models, suggest that in the world's largest and most crowded cities, heat emissions from human metabolism alone can force measurable change in mean annual temperature at regional scale.

  10. Mast cell release of superoxide

    SciTech Connect

    Dileepan, K.N.; Simpson, K.M.; Stechschulte, D.J.

    1987-05-01

    The ability of rat serosal mast cells (MC) to release superoxide (O/sub 2//sup -/) upon activation by immunologic and nonimmunologic stimuli was investigated. Purified MC (90-95%) were either sensitized with monoclonal IgE reactive against dinitrophenyl bovine serum albumin (DNP-BSA) and challenged with DNP-BSA, or naive MC were treated with compound 48/80 or ionophore A23187. O/sub 2//sup -/ release was measured by O/sub 2//sup -/ dismutase (SOD)-sensitive reduction of cytochrome C and MC activation was assessed by the release of histamine or (/sup 14/C)5-hydroxytryptamine (5HT). The results reveal that activation of MC by 48/80 or immunologic challenge does not release O/sub 2//sup -/, although these stimuli induce substantial release of histamine and 5HT (40-70%). In contrast, A23187 released O/sub 2//sup -/ (3-6 nMols/10/sup 6/ MC) and histamine (40-80%). In mixed cell preparations containing MC and macrophages (M0), activation of MC with 48/80 resulted in inhibition of M0 O/sub 2//sup -/ release. The MC-mediated inhibition of O/sub 2//sup -/ production was not due to histamine or 5HT, but was due to MC-granule SOD. MC contain abundant quantities of SOD and, therefore, release O/sub 2//sup -/ only when its production exceeds the intracellular SOD threshold following activation with selective stimuli. In addition, the apparent differences in the mode and site of action of various stimuli on MC may contribute to the discriminative release of O/sub 2//sup -/.

  11. Data summary report for fission product release test VI-3

    SciTech Connect

    Osborne, M.F.; Lorenz, R.A.; Collins, J.L.; Travis, J.R.; Webster, C.S.; Lee, H.K.; Nakamura, T.; Tong, Y.-C. )

    1990-06-01

    Test VI-3, the third in a series of high-temperature fission product release tests in the vertical test apparatus, was conducted in flowing steam. 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 42 MWd/kg. Using an induction furnace, it was heated under simulated light-water reactor (LWR) accident conditions to two test temperatures, 20 min at 2000 K and then 20 min at 2700 K, in a hot cell-mounted test apparatus. The released fission products were collected on components designed to facilitate sampling and analysis. Posttest inspection confirmed that the cladding had been completely oxidized during the test. Only minimal fragmentation of the fuel specimen was found, however, and very little melting or fuel-cladding interaction had occurred. Based on fission product inventories measured in the fuel or calculated by ORIGEN2, analyses of test components showed total releases from the fuel of 100% for {sup 85}Kr, 5% for {sup 106}Ru, 99% for {sup 125}Sb, and 99% for both {sup 134}Cs and {sup 137}Cs. A large fraction (27%) of the released {sup 125}Sb was retained in the furnace, but most of the released cesium (89%) escaped to the collection system. In addition, very small amounts of fuel material --- uranium and plutonium --- were released. Including fission products and fuel and structural materials, the total mass released from the furnace to the collection system was 3.17 g, 78% of which was collected on the filters. The results from this test were compared with previous tests in this series and with a commonly used model for fission product release. 25 refs., 22 figs., 14 tabs.

  12. 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.

  13. Hydrophobic Drug-Loaded PEGylated Magnetic Liposomes for Drug-Controlled Release

    NASA Astrophysics Data System (ADS)

    Hardiansyah, Andri; Yang, Ming-Chien; Liu, Ting-Yu; Kuo, Chih-Yu; Huang, Li-Ying; Chan, Tzu-Yi

    2017-05-01

    Less targeted and limited solubility of hydrophobic-based drug are one of the serious obstacles in drug delivery system. Thus, new strategies to enhance the solubility of hydrophobic drug and controlled release behaviors would be developed. Herein, curcumin, a model of hydrophobic drug, has been loaded into PEGylated magnetic liposomes as a drug carrier platform for drug controlled release system. Inductive magnetic heating (hyperthermia)-stimulated drug release, in vitro cellular cytotoxicity assay of curcumin-loaded PEGylated magnetic liposomes and cellular internalization-induced by magnetic guidance would be investigated. The resultant of drug carriers could disperse homogeneously in aqueous solution, showing a superparamagnetic characteristic and could inductive magnetic heating with external high-frequency magnetic field (HFMF). In vitro curcumin release studies confirmed that the drug carriers exhibited no significant release at 37 °C, whereas exhibited rapid releasing at 45 °C. However, it would display enormous (three times higher) curcumin releasing under the HFMF exposure, compared with that without HFMF exposure at 45 °C. In vitro cytotoxicity test shows that curcumin-loaded PEGylated magnetic liposomes could efficiently kill MCF-7 cells in parallel with increasing curcumin concentration. Fluorescence microscopy observed that these drug carriers could internalize efficiently into the cellular compartment of MCF-7 cells. Thus, it would be anticipated that the novel hydrophobic drug-loaded PEGylated magnetic liposomes in combination with inductive magnetic heating are promising to apply in the combination of chemotherapy and thermotherapy for cancer therapy.

  14. 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)

  15. Immunophilin regulation of neurotransmitter release.

    PubMed Central

    Steiner, J. P.; Dawson, T. M.; Fotuhi, M.; Snyder, S. H.

    1996-01-01

    BACKGROUND: The immunophilins are proteins that mediate actions of immunosuppressant drugs such as FK506 and cyclosporin A by binding to calcineurin, inhibiting its phosphatase activity, and increasing the phosphorylation level of transcription factors required for interleukin 2 formation. Though concentrations in the brain greatly exceed levels in immune tissues, no function has been previously established for nervous system immunophilins. Nitric oxide (NO) has been implicated in neurotransmitter release. FK506 appears to inhibit NO production by maintaining NO synthase in a highly phosphorylated and thereby inactivated state. Accordingly, we examined effects of FK506 and cyclosporin A on neurotransmitter release in PC12 cells treated with nerve growth factor (NGF) and in rat brain striatal synaptosomes. MATERIALS AND METHODS: We monitored effects of immunophilin ligands on [3H]-neurotransmitter release from PC12 cells differentiated with NGF. Rat brain striatal synaptosomes were loaded with radiolabeled transmitters and treated with FK506 or cyclosporin A prior to initiating neurotransmitter release with N-methyl-D-aspartate (NMDA) or potassium depolarization. Striatal synaptosomes were also loaded with 32P-orthophosphate and treated with FK506. 32P-labeled synaptic vesicle proteins were isolated from these synaptosomes in an attempt to relate specific FK506-dependent phosphorylation of vesicle proteins with the effects of FK506 on neurotransmitter release. Identification of proteins targetted by FK506 was made by immunoblot analysis and immunoprecipitation. RESULTS: Low nanomolar concentrations of the immunosuppressant drugs FK506 and cyclosporin A (CsA) inhibit transmitter release from PC-12 cells and from NMDA-stimulated brain synaptosomes. By contrast, the immunosuppressants augment depolarization-induced transmitter release from synaptosomes. Synapsin I, a synaptic vesicle phosphoprotein, displays enhanced phosphorylation in the presence of FK506

  16. 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.

  17. 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

  18. 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.

  19. 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.

  20. 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.