Science.gov

Sample records for localized heat production

  1. Heat Flow and Heat Production in Korea

    NASA Astrophysics Data System (ADS)

    Lee, Y.; Kim, J.; Kim, H.; Hwang, S.; Koo, M.

    2007-12-01

    The mean heat flow in Korea estimated in 365 locations (mines, coal fields, groundwater, hot spring wells) is 60 11 mW/m2; mean geothermal gradients is 25.1 C/km. High heat flow values appear in the southeastern part, the central western part, and the northeastern part of Korea. In the tectonic provinces, heat flow is 66 mW/m2 for Gyeonggi Massif, 65 mW/m2 for Okcheon Fold Belt, 60 mW/m2 for Yeongnam Massif, 72 mW/m2 for Gyeongsang Basin, and 75 mW/m2 for Yeonil Basin. In the aspect of the lithology, heat flow is 71 2 mW/m2 for the sedimentary rock area, 68 2 mW/m2 for the sedimentary/volcanic rock area, 67 1 mW/m2 for the plutonic rock area, and 62 2 mW/m2 for the metamorphic rock area. In the geological time sequence, heat flow is 78 5 mW/m2 for the Cenozoic strata, 68 1 mW/m2 for Mesozoic, 65 3 mW/m2 for the Paleozoic strata, 67 8 mW/m2 for the Proterozoic strata, and 62 2 mW/m2 for the Archean strata. From the relationship between heat flow and Moho depth, we found that the shallow Moho depth area is likely to have higher heat flow values than the area of the thick crust. Heat production was measured by chemical analysis and gamma-ray logs on basement rocks (86 granite and 37 gneiss samples). The mean heat production is 2.15 ?W/m3 for granite, and 2.22 ?W/m3 for gneiss. The mean heat production is 2.52 ?W/m3 for Gyeonggi Massif, 2.16 ?W/m3 for Okcheon Fold Belt, 2.35 ?W/m3 for Yeongnam Massif, and 2.01 ?W/m3 for Gyeongsang Basin. The tectonic provinces with high mean heat flow tend to have low mean heat production. Therefore, heat production is unlikely to have a first-order importance in determining surface heat flow distribution in Korea. The analysis of 12 heat production and heat flow data sets from granite area in Gyeongsang Basin shows a linear relationship between heat production and surface heat flow, which is known as q=qr+AD, where q is surface heat flow, qr is reduced heat flow, A is heat production, and D is characteristic depth. We found q=47.06+12.29A for Gyeongsang Basin.

  2. Local heating realization by reverse thermal cloak

    PubMed Central

    Hu, Run; Wei, Xuli; Hu, Jinyan; Luo, Xiaobing

    2014-01-01

    Transformation thermodynamics, as one of the important branches among the extensions of transformation optics, has attracted plentiful attentions and interests recently. The result of transformation thermodynamics, or called as “thermal cloak”, can realize isothermal region and hide objects from heat. In this paper, we presented the concept of “reverse thermal cloak” to correspond to the thermal cloak and made a simple engineering definition to identify them. By full-wave simulations, we verified that the reverse thermal cloak can concentrate heat and realize local heating. The performance of local heating depends on the anisotropic dispersion of the cloaking layer's thermal conductivity. Three-dimensional finite element simulations demonstrated that the reverse thermal cloak can be used to heat up objects. Besides pre-engineered metamaterials, such reverse thermal cloak can even be realized with homogenous materials by alternating spoke-like structure or Hashin coated-sphere structure. PMID:24398592

  3. Local heating realization by reverse thermal cloak.

    PubMed

    Hu, Run; Wei, Xuli; Hu, Jinyan; Luo, Xiaobing

    2014-01-01

    Transformation thermodynamics, as one of the important branches among the extensions of transformation optics, has attracted plentiful attentions and interests recently. The result of transformation thermodynamics, or called as "thermal cloak", can realize isothermal region and hide objects from heat. In this paper, we presented the concept of "reverse thermal cloak" to correspond to the thermal cloak and made a simple engineering definition to identify them. By full-wave simulations, we verified that the reverse thermal cloak can concentrate heat and realize local heating. The performance of local heating depends on the anisotropic dispersion of the cloaking layer's thermal conductivity. Three-dimensional finite element simulations demonstrated that the reverse thermal cloak can be used to heat up objects. Besides pre-engineered metamaterials, such reverse thermal cloak can even be realized with homogenous materials by alternating spoke-like structure or Hashin coated-sphere structure. PMID:24398592

  4. Local Laser Heat Treatments of Steel Sheets

    NASA Astrophysics Data System (ADS)

    Jrvenp, A.; Jaskari, M.; Hietala, M.; Mntyjrvi, K.

    In this work UHS structural and abrasion resistant (AR) steels were heat treated with a single 4 kW Yb: YAG-laser beam. Aim of the softening heat treatments was to enhance the formability locally with minimized strength lose. 1.8 mm thick B24CR boron steel was used for hardening tests. Study presents the possibilities and limitations in laser processing showing that a single laser beam is suitable for heat treating of sheets through the whole cross-section up to the thickness of 6 mm. In the case of the 6 mm thick sheets, the achieved maximum temperature in the cross-section varies as a function of the depth. Consequently, the microstructure and mechanical properties differ between the surfaces and the center of the cross-section (layered microstructure). For better understanding, all layers were tested in tensile tests. The 10 mm thick sheet was heat treated separately on the both surfaces by heating to a lower temperature range to produce a shallow tempered layer. The tensile and bendability tests as well as hardness measurements indicated that laser heat treatment can be used to highly improve the bendability locally without significant strength losses. Laser process has been optimized by transverse scanning movement and with a simple FE-model.

  5. Effects of local heating of the testes on the concentration of testosterone in jugular and testicular venous blood of rats and on testosterone production in vitro.

    PubMed

    Galil, K A; Setchell, B P

    1988-02-01

    Heating both testes of rats to between 39 degrees C and 41 degrees C for 30 min was apparently without effect 21 days later, but heating to between 41.5 degrees C and 43 degrees C for 30 min resulted in a significant drop in testis weight accompanied by significant rises in the serum levels of LH and FSH. There were no changes in serum testosterone concentration in the peripheral circulation although there were increases in the concentration in testicular venous blood. The ability of the heated testis to secrete testosterone in vivo in response to maximal stimulation by hCG was reduced, as judged by testosterone levels in peripheral blood, while there was a supranormal increase in testosterone levels in testicular venous blood. Maximally stimulated testosterone production in vitro by the heated testis was supranormal whereas the basal production of testosterone per testis was not different from control values. Therefore, it appears that the testosterone produced by Leydig cells from heated testes may not be secreted as effectively as in normal testes. PMID:3128487

  6. Compact Directional Microwave Antenna for Localized Heating

    NASA Technical Reports Server (NTRS)

    Fink, Patrick W.; Lin, Gregory Y.; Chu, Andrew W.; Dobbins, Justin A.; Arndt, G. Dickey; Ngo, Phong

    2008-01-01

    A directional, catheter-sized cylindrical antenna has been developed for localized delivery of microwave radiation for heating (and thus killing) diseased tissue without excessively heating nearby healthy tissue. By "localized" is meant that the antenna radiates much more in a selected azimuthal direction than in the opposite radial direction, so that it heats tissue much more on one side than it does on the opposite side. This antenna can be inserted using either a catheter or a syringe. A 2.4-mm prototype was tested, although smaller antennas are possible. Prior compact, cylindrical antennas designed for therapeutic localized hyperthermia do not exhibit such directionality; that is, they radiate in approximately axisymmetric patterns. Prior directional antennas designed for the same purpose have been, variously, (1) too large to fit within catheters or (2) too large, after deployment from catheters, to fit within the confines of most human organs. In contrast, the present antenna offers a high degree of directionality and is compact enough to be useable as a catheter in some applications.

  7. Induction heating plant for heat treatment of spherical metal products

    NASA Astrophysics Data System (ADS)

    Meshcheryakov, V. N.; Titov, S. S.

    2015-12-01

    A control system for an induction heating plant is developed and studied to perform symmetric high-rate surface induction heating of spherical metal products with given technological parameters for heat treatment.

  8. Multi-Annual Data Products on Turbulent Heat Fluxes at the Local and Continental Scale Using AATSR and FY-2 Data

    NASA Astrophysics Data System (ADS)

    Menenti, M.; Ghafarian, H.; Tang, B.; Faivre, R.; Colin, J.; Jia, L.; Roupios, L.

    2013-01-01

    This paper summarizes the results of studies carried in the framework of the Dragon 2 Program - Project 5322 Key Eco-Hydrological Parameters Retrieval and Land Data Assimilation System Development in a Typical Inland River Basin of Chinas Arid Region. The investigations were focused on monitoring the fluxes of energy and water at the land-atmosphere interface across a range of spatial scales, using multi-spectral radiometric data collected by space-borne imaging radiometers. At the local scale a new approach to parameterize heat and vapour fluxes was developed and applied using Computational Fluid Dynamics to describe state and dynamics of the boundary layer over the heterogeneous and 3D structured land surface. An airborne scanning LIDAR was used to capture in detail surface geometry. Over the large area of the Qinghai-Tibet Plateau a land-atmospheric model was used to characterize the atmospheric Planetary Boundary Layer. The effect of land surface heterogeneity and structure on the exchange of heat and water was captured using the bi-angular observations of brightness temperature provided by the AATSR imaging radiometer. The heat and water flux densities were calculated hourly with Feng-Yun C, D and E VISSR data over the Qinghai-Tibet Plateau and the headwaters of main rivers around it.

  9. Implantable apparatus for localized heating of tissue

    DOEpatents

    Doss, J.D.

    1985-05-20

    With the object of repetitively treating deep-seated, inoperable tumors by hyperthermia as well as locally heating other internal tissue masses repetitively, a receiving antenna, transmission line and electrode arrangement are implanted completely within the patient's body, with the receiving antenna just under the surface of the skin and with the electrode arrangement being located so as to most effectively heat the tissue to be treated. An external, transmitting antenna, driven by an external radio-frequency energy source, is closely coupled to the implanted receiving antenna so that the energy coupled across the air-skin interface provides electromagnetic energy suitable for heating the tissue in the vicinity of the implanted electrodes. The resulting increase in tissue temperature may be estimated by an indirect measurement of the decrease in tissue resistivity in the heat region. This change in resistivity appears as a change in the loading of the receiving antenna which can be measured by either determining the change in the phase relationship between the voltage and the current appearing on the transmitting antenna or by measuring the change in the magnitude of the impedance thereof. Optionally, multiple electrode arrays may be activated or inactivated by the application of magnetic fields to operate implanted magnetic reed swtiches. 5 figs.

  10. Implantable apparatus for localized heating of tissue

    DOEpatents

    Doss, James D.

    1987-01-01

    With the object of repetitively treating deep-seated, inoperable tumors by hyperthermia as well as locally heating other internal tissue masses repetitively, a receiving antenna, transmission line, and electrode arrangment are implanted completely within the patient's body, with the receiving antenna just under the surface of the skin and with the electrode arrangement being located so as to most effectively heat the tissue to be treated. An external, transmitting antenna, driven by an external radio-frequency energy source, is closely coupled to the implanted receiving antenna so that the energy coupled across the air-skin interface provides electromagnetic energy suitable for heating the tissue in the vicinity of the implanted electrodes. The resulting increase in tissue temperature may be estimated by an indirect measurement of the decrease in tissue resistivity in the heated region. This change in resistivity appears as a change in the loading of the receiving antenna which can be measured by either determining the change in the phase relationship between the voltage and the current appearing on the transmitting antenna or by measuring the change in the magnitude of the impedance thereof. Optionally, multiple electrode arrays may be activated or inactivated by the application of magnetic fields to operate implanted magnetic reed switches.

  11. DNA transformation via local heat shock

    NASA Astrophysics Data System (ADS)

    Li, Sha; Meadow Anderson, L.; Yang, Jui-Ming; Lin, Liwei; Yang, Haw

    2007-07-01

    This work describes transformation of foreign DNA into bacterial host cells by local heat shock using a microfluidic system with on-chip, built-in platinum heaters. Plasmid DNA encoding ampicillin resistance and a fluorescent protein can be effectively transformed into the DH5? chemically competent E. coli using this device. Results further demonstrate that only one-thousandth of volume is required to obtain transformation efficiencies as good as or better than conventional practices. As such, this work complements other lab-on-a-chip technologies for potential gene cloning/therapy and protein expression applications.

  12. Localized rapid heating process for precision chalcogenide glass molding

    NASA Astrophysics Data System (ADS)

    Li, Hui; He, Peng; Yu, Jianfeng; Lee, L. James; Yi, Allen Y.

    2015-10-01

    Precision glass molding is an important process for high volume optical fabrication. However, conventional glass molding is a bulk heating process that usually requires a long thermal cycle, where molding assembly and other mechanical parts are heated and cooled together. This often causes low efficiency and other heating and cooling related problems, such as large thermal expansion in both the molds and molded optics. To cope with this issue, we developed a localized rapid heating process to effectively heat only very small part of the glass. This localized rapid heating study utilized a fused silica wafer coated with a thin graphene layer to heat only the surface of the glass. The graphene coating functions as an electrical resistant heater when a power source was applied across the thin film coating, generating heat on and near the coating. The feasibility of this process was validated by both experiments and numerical simulation. To demonstrate the advantages of the localized rapid heating, both localized rapid heating process and bulk heating process were performed and carefully compared. The uniformity and quality of the molded sample by localized rapid heating process was also demonstrated. In summary, localized rapid heating process by using graphene coated fused silica wafer was characterized and can be readily implemented in replication of micro scale chalcogenide glasses. A fused silica wafer coated with a thin graphene layer was utilized for localized rapid heating only the surface of the glass. The graphene coating functions as an electrical resistant heater when a power source was applied across the thin film coating, generating high temperature on and near the coating. This process is fast and efficient since only interested areas are heated without affecting the entire glass substrate or the mold assembly. The uniformity and quality of the molded sample by localized rapid heating process was demonstrated by comparing both localized rapid heating process and conventional bulk heating process.

  13. Interface Shape Control Using Localized Heating during Bridgman Growth

    NASA Technical Reports Server (NTRS)

    Volz, M. P.; Mazuruk, K.; Aggarwal, M. D.; Croll, A.

    2008-01-01

    Numerical calculations were performed to assess the effect of localized radial heating on the melt-crystal interface shape during vertical Bridgman growth. System parameters examined include the ampoule, melt and crystal thermal conductivities, the magnitude and width of localized heating, and the latent heat of crystallization. Concave interface shapes, typical of semiconductor systems, could be flattened or made convex with localized heating. Although localized heating caused shallower thermal gradients ahead of the interface, the magnitude of the localized heating required for convexity was less than that which resulted in a thermal inversion ahead of the interface. A convex interface shape was most readily achieved with ampoules of lower thermal conductivity. Increasing melt convection tended to flatten the interface, but the amount of radial heating required to achieve a convex interface was essentially independent of the convection intensity.

  14. Boiling local heat transfer enhancement in minichannels using nanofluids.

    PubMed

    Chehade, Ali Ahmad; Gualous, Hasna Louahlia; Le Masson, Stephane; Fardoun, Farouk; Besq, Anthony

    2013-01-01

    This paper reports an experimental study on nanofluid convective boiling heat transfer in parallel rectangular minichannels of 800 ?m hydraulic diameter. Experiments are conducted with pure water and silver nanoparticles suspended in water base fluid. Two small volume fractions of silver nanoparticles suspended in water are tested: 0.000237% and 0.000475%. The experimental results show that the local heat transfer coefficient, local heat flux, and local wall temperature are affected by silver nanoparticle concentration in water base fluid. In addition, different correlations established for boiling flow heat transfer in minichannels or macrochannels are evaluated. It is found that the correlation of Kandlikar and Balasubramanian is the closest to the water boiling heat transfer results. The boiling local heat transfer enhancement by adding silver nanoparticles in base fluid is not uniform along the channel flow. Better performances and highest effect of nanoparticle concentration on the heat transfer are obtained at the minichannels entrance. PMID:23506445

  15. Boiling local heat transfer enhancement in minichannels using nanofluids

    PubMed Central

    2013-01-01

    This paper reports an experimental study on nanofluid convective boiling heat transfer in parallel rectangular minichannels of 800 ?m hydraulic diameter. Experiments are conducted with pure water and silver nanoparticles suspended in water base fluid. Two small volume fractions of silver nanoparticles suspended in water are tested: 0.000237% and 0.000475%. The experimental results show that the local heat transfer coefficient, local heat flux, and local wall temperature are affected by silver nanoparticle concentration in water base fluid. In addition, different correlations established for boiling flow heat transfer in minichannels or macrochannels are evaluated. It is found that the correlation of Kandlikar and Balasubramanian is the closest to the water boiling heat transfer results. The boiling local heat transfer enhancement by adding silver nanoparticles in base fluid is not uniform along the channel flow. Better performances and highest effect of nanoparticle concentration on the heat transfer are obtained at the minichannels entrance. PMID:23506445

  16. Boiling local heat transfer enhancement in minichannels using nanofluids

    NASA Astrophysics Data System (ADS)

    Chehade, Ali Ahmad; Gualous, Hasna Louahlia; Le Masson, Stephane; Fardoun, Farouk; Besq, Anthony

    2013-03-01

    This paper reports an experimental study on nanofluid convective boiling heat transfer in parallel rectangular minichannels of 800 ?m hydraulic diameter. Experiments are conducted with pure water and silver nanoparticles suspended in water base fluid. Two small volume fractions of silver nanoparticles suspended in water are tested: 0.000237% and 0.000475%. The experimental results show that the local heat transfer coefficient, local heat flux, and local wall temperature are affected by silver nanoparticle concentration in water base fluid. In addition, different correlations established for boiling flow heat transfer in minichannels or macrochannels are evaluated. It is found that the correlation of Kandlikar and Balasubramanian is the closest to the water boiling heat transfer results. The boiling local heat transfer enhancement by adding silver nanoparticles in base fluid is not uniform along the channel flow. Better performances and highest effect of nanoparticle concentration on the heat transfer are obtained at the minichannels entrance.

  17. Human local and total heat losses in different temperature.

    PubMed

    Wang, Lijuan; Yin, Hui; Di, Yuhui; Liu, Yanfeng; Liu, Jiaping

    2016-04-01

    This study investigates the effects of operative temperature on the local and total heat losses, and the relationship between the heat loss and thermal sensation. 10 local parts of head, neck, chest, abdomen, upper arm, forearm, hand, thigh, leg and foot are selected. In all these parts, convection, radiation, evaporation, respiration, conduction and diffusion heat losses are analyzed when operative temperature is 23, 28, 33 and 37°C. The local heat losses show that the radiation and convection heat losses are mainly affected by the area of local body, and the heat loss of the thigh is the most in the ten parts. The evaporation heat loss is mainly affected by the distribution of sweat gland, and the heat loss of the chest is the most. The total heat loss of the local body shows that in low temperature, the thigh, leg and chest have much heat loss, while in high temperature, the chest, abdomen, thigh and head have great heat loss, which are useful for clothing design. The heat losses of the whole body show that as the operative temperature increases, the radiation and convection heat losses decrease, the heat losses of conduction, respiration, and diffusion are almost constant, and the evaporation heat loss increases. By comparison, the heat loss ratios of the radiation, convection and sweat evaporation, are in agreement with the previous researches. At last, the formula about the heat loss ratio of convection and radiation is derived. It's useful for thermal comfort evaluation and HVAC (heating, ventilation and air conditioning) design. PMID:26879106

  18. Localized electron heating and density peaking in downstream helicon plasma

    NASA Astrophysics Data System (ADS)

    Ghosh, Soumen; Barada, K. K.; Chattopadhyay, P. K.; Ghosh, J.; Bora, D.

    2015-06-01

    Localized electron temperature and density peaking at different axial locations in the downstream helicon plasma have been observed in a linear helicon device with both geometrical and magnetic expansion. The discharge is produced with an m=+1 right helical antenna powered by a RF source operating at 13.56 MHz. Axial wave field measurement shows the presence of damped helicon waves with standing wave character folded into it even at low densities ( {{10}16} m-3 ). The measured helicon wavelength is just about twice the antenna length and the phase velocity ?ft({{v}p}\\right) is almost the speed required for electron impact ionization. These experimental observations strongly advocate the Landau damping heating and density production by the helicon waves, particularly in low density plasma such as ours. The electron temperature maximizes at 35-45?cm away from the antenna center in our experiments indicating a local source of heating at those locations. Different mechanisms responsible for this additional heating at a particular spatial location have been discussed for their possible roles. Further downstream from the location of the maximum electron temperature, a density peak located 55-65?cm away from the antenna is observed. This downstream density peaking can be explained through pressure balance in the system.

  19. Heat Production as a Tool in Geothermal Exploration

    NASA Astrophysics Data System (ADS)

    Rhodes, J. M.; Koteas, C.; Mabee, S. B.; Thomas, M.; Gagnon, T.

    2012-12-01

    Heat flow data (together with knowledge, or assumptions, of stratigraphy, thermal conductivity and heat production) provide the prime parameter for estimating the potential of geothermal resources. Unfortunately this information is expensive to obtain as it requires deep boreholes. Consequently it is sparse or lacking in areas not traditionally considered as having geothermal potential. New England (and most of the northeastern U.S.A.) is one such area. However, in the absence of volcano-derived hydrothermal activity with its attendant high heat flow, granitic plutons provide an alternative geothermal resource. Compared with other crustal rocks, granites contain higher concentrations of heat-producing elements (K, U, Th). Additionally, they are relatively homogeneous, compared to surrounding country rock, allowing for stimulation through hydro-fracking of large (>1 km3) geothermal reservoirs. Consequently we have adopted a different approach, obtaining heat production data rather then relying on the very sparse heat flow data. Birch and colleagues long since recognized the relationship between heat flow and heat production as an integral part of their concept of Heat Flow Provinces. Heat production is readily determined in the laboratory by measuring the density of a sample and the concentrations of its heat-producing elements potassium, uranium and thorium. We have determined the heat production for 570 samples from most of the major granitic and gneissic bodies in Massachusetts and Connecticut. We have also measured these parameters for 70 sedimentary rocks that cover granites and gneiss in the Connecticut and Narragansett Basins. This data is being used to calculate inferred heat flow data for these localities. Comparison of these inferred heat flow values with the sparse number of those measured directly in boreholes in the two States is encouraging, indicating that this approach has merit. We have also measured thermal conductivity on all of these samples. This, together with the measured heat production and the inferred heat flow allow the calculation of inferred temperature - depth profiles for these localities, from which we have produced maps showing the distribution of heat production, thermal conductivity, inferred heat flow and inferred temperatures at depths of 2, 4 and 6 km in the two States. We believe that this is a rapid and relatively cheap approach for evaluating the geothermal potential of a region lacking in heat flow data allowing identification of areas that warrant more detailed investigation which would include geophysical surveys and drilling. In Massachusetts and Connecticut such areas include the Fitchburg pluton, Permian granites and the Narragansett and Hartford Basins, where gneiss and granites are buried beneath Carboniferous and Triassic sediments respectively. This project is funded by the Department of Energy through an award to the Association of American State Geologists.

  20. Impact of Heat Stress on Poultry Production

    PubMed Central

    Lara, Lucas J.; Rostagno, Marcos H.

    2013-01-01

    Simple Summary Due to the common occurrence of environmental stressors worldwide, many studies have investigated the detrimental effects of heat stress on poultry production. It has been shown that heat stress negatively affects the welfare and productivity of broilers and laying hens. However, further research is still needed to improve the knowledge of basic mechanisms associated to the negative effects of heat stress in poultry, as well as to develop effective interventions. Abstract Understanding and controlling environmental conditions is crucial to successful poultry production and welfare. Heat stress is one of the most important environmental stressors challenging poultry production worldwide. The detrimental effects of heat stress on broilers and laying hens range from reduced growth and egg production to decreased poultry and egg quality and safety. Moreover, the negative impact of heat stress on poultry welfare has recently attracted increasing public awareness and concern. Much information has been published on the effects of heat stress on productivity and immune response in poultry. However, our knowledge of basic mechanisms associated to the reported effects, as well as related to poultry behavior and welfare under heat stress conditions is in fact scarce. Intervention strategies to deal with heat stress conditions have been the focus of many published studies. Nevertheless, effectiveness of most of the interventions has been variable or inconsistent. This review focuses on the scientific evidence available on the importance and impact of heat stress in poultry production, with emphasis on broilers and laying hens. PMID:26487407

  1. Measurement of local high-level, transient surface heat flux

    NASA Technical Reports Server (NTRS)

    Liebert, Curt H.

    1988-01-01

    This study is part of a continuing investigation to develop methods for measuring local transient surface heat flux. A method is presented for simultaneous measurements of dual heat fluxes at a surface location by considering the heat flux as a separate function of heat stored and heat conducted within a heat flux gage. Surface heat flux information is obtained from transient temperature measurements taken at points within the gage. Heat flux was determined over a range of 4 to 22 MW/sq m. It was concluded that the method is feasible. Possible applications are for heat flux measurements on the turbine blade surfaces of space shuttle main engine turbopumps and on the component surfaces of rocket and advanced gas turbine engines and for testing sensors in heat flux gage calibrators.

  2. Solar steam generation by heat localization

    NASA Astrophysics Data System (ADS)

    Ghasemi, Hadi; Ni, George; Marconnet, Amy Marie; Loomis, James; Yerci, Selcuk; Miljkovic, Nenad; Chen, Gang

    2014-07-01

    Currently, steam generation using solar energy is based on heating bulk liquid to high temperatures. This approach requires either costly high optical concentrations leading to heat loss by the hot bulk liquid and heated surfaces or vacuum. New solar receiver concepts such as porous volumetric receivers or nanofluids have been proposed to decrease these losses. Here we report development of an approach and corresponding material structure for solar steam generation while maintaining low optical concentration and keeping the bulk liquid at low temperature with no vacuum. We achieve solar thermal efficiency up to 85% at only 10?kW?m-2. This high performance results from four structure characteristics: absorbing in the solar spectrum, thermally insulating, hydrophilic and interconnected pores. The structure concentrates thermal energy and fluid flow where needed for phase change and minimizes dissipated energy. This new structure provides a novel approach to harvesting solar energy for a broad range of phase-change applications.

  3. Local, instantaneous heat transfer in pulse-stabilized fluidization

    SciTech Connect

    Pence, D.V.; Beasley, D.E.

    1996-12-31

    The Pulsed Atmospheric Fluidized Bed Combustor (PAFBC), a hybrid combustor concept that couples a pulsed combustor with an atmospheric bubbling fluidized bed, has technical advantages in energy efficiency and emissions. The present study examines the effect of an opposing oscillatory flow on the local, instantaneous heat transfer in a laboratory scale bubbling gas-fluidized bed. This opposing secondary flow consisted of a steady mean component and an oscillating component thereby modeling the flow in the tailpipe of a pulsed combustor. Spectral and contact time analyses of local, instantaneous heat flux measurements from a heated, submerged horizontal cylinder clearly indicate that the bed hydrodynamics were significantly altered by the opposing secondary flow. These heat flux measurements were accomplished by employing an isothermal platinum film heat flux gage. For the present investigation, data were acquired for a monodisperse distribution of particles with a mean diameter of 345 {micro}m and total fluidization ratios ranging from 1.1 through 2.7. Heat transfer observed under conditions of secondary flows with a superimposed waveform exhibit characteristics of globally dominated, as opposed to locally dominated, hydrodynamics. For low primary and secondary flow rates and a forcing frequency of 5 Hz, a substantial enhancement in heat transfer was observed. Increases in the bubble phase and emulsion phase heat transfer coefficients were identified as the primary contributors to the observed increases in time-averaged local heat transfer coefficients.

  4. Cascade heat recovery with coproduct gas production

    DOEpatents

    Brown, William R. (Zionsville, PA); Cassano, Anthony A. (Allentown, PA); Dunbobbin, Brian R. (Allentown, PA); Rao, Pradip (Allentown, PA); Erickson, Donald C. (Annapolis, MD)

    1986-01-01

    A process for the integration of a chemical absorption separation of oxygen and nitrogen from air with a combustion process is set forth wherein excess temperature availability from the combustion process is more effectively utilized to desorb oxygen product from the absorbent and then the sensible heat and absorption reaction heat is further utilized to produce a high temperature process stream. The oxygen may be utilized to enrich the combustion process wherein the high temperature heat for desorption is conducted in a heat exchange preferably performed with a pressure differential of less than 10 atmospheres which provides considerable flexibility in the heat exchange.

  5. Cascade heat recovery with coproduct gas production

    DOEpatents

    Brown, W.R.; Cassano, A.A.; Dunbobbin, B.R.; Rao, P.; Erickson, D.C.

    1986-10-14

    A process for the integration of a chemical absorption separation of oxygen and nitrogen from air with a combustion process is set forth wherein excess temperature availability from the combustion process is more effectively utilized to desorb oxygen product from the absorbent and then the sensible heat and absorption reaction heat is further utilized to produce a high temperature process stream. The oxygen may be utilized to enrich the combustion process wherein the high temperature heat for desorption is conducted in a heat exchange preferably performed with a pressure differential of less than 10 atmospheres which provides considerable flexibility in the heat exchange. 4 figs.

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

    NASA Astrophysics Data System (ADS)

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

    2011-09-01

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

  7. Linear irreversible heat engines based on local equilibrium assumptions

    NASA Astrophysics Data System (ADS)

    Izumida, Yuki; Okuda, Koji

    2015-08-01

    We formulate an endoreversible finite-time Carnot cycle model based on the assumptions of local equilibrium and constant energy flux, where the efficiency and the power are expressed in terms of the thermodynamic variables of the working substance. By analyzing the entropy production rate caused by the heat transfer in each isothermal process during the cycle, and using the endoreversible condition applied to the linear response regime, we identify the thermodynamic flux and force of the present system and obtain a linear relation that connects them. We calculate the efficiency at maximum power in the linear response regime by using the linear relation, which agrees with the Curzon-Ahlborn (CA) efficiency known as the upper bound in this regime. This reason is also elucidated by rewriting our model into the form of the Onsager relations, where our model turns out to satisfy the tight-coupling condition leading to the CA efficiency.

  8. Heat and moisture production of modern swine

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The heat and moisture production (HP and MP) values that are currently published in the American Society of Heating, Refrigeration, and Air-Conditioning Engineers (ASHRAE) standards are from data collected in either the 1970s (nursery piglets) or the 1950s (growing-finishing pigs). This series of ...

  9. Local Production: Principles and Practice

    ERIC Educational Resources Information Center

    Whittell, J. M. S.

    1975-01-01

    Presents the problems of Third World countries in acquiring science equipment to augment their science curriculum development plans. Outlines an attempt by Kenya Science Teachers College to produce and supply science equipment. Describes the approach to production, quality control, and costing and sales. (GS)

  10. Global and local Joule heating effects seen by DE 2

    NASA Technical Reports Server (NTRS)

    Heelis, R. A.; Coley, W. R.

    1988-01-01

    In the altitude region between 350 and 550 km, variations in the ion temperature principally reflect similar variations in the local frictional heating produced by a velocity difference between the ions and the neutrals. Here, the distribution of the ion temperature in this altitude region is shown, and its attributes in relation to previous work on local Joule heating rates are discussed. In addition to the ion temperature, instrumentation on the DE 2 satellite also provides a measure of the ion velocity vector representative of the total electric field. From this information, the local Joule heating rate is derived. From an estimate of the height-integrated Pedersen conductivity it is also possible to estimate the global (height-integrated) Joule heating rate. Here, the differences and relationships between these various parameters are described.

  11. Heat exchangers for the new production reactor

    SciTech Connect

    Ondrejcin, R.S.

    1988-07-26

    Heat exchangers will be needed for the New Production Reactor (NRP). Present design calls for a cross flow shell and tube heat exchanger, the type that has been used in the SRP production reactors. This type of design is very popular and is found in most United States heat transfer texts. Other designs are available that are more efficient and there was impetus to develop these, especially during the OPEC produced energy shortage of the early 1970's. This memorandum presents a comparison between the shell and tube and a more efficient design known as the plate heat exchanger. Improvements in this design appear to have been more actively pursued in Europe than in the United States. The initial patent on plate heat exchangers was issued about 100 years ago, but recently has become more frequently used by multinational companies since some early manufacturing problems have been solved and available sizes have increased. 4 refs.

  12. Universal constant for heat production in protists.

    PubMed

    Johnson, Matthew D; Vlker, Jens; Moeller, Holly V; Laws, Edward; Breslauer, Kenneth J; Falkowski, Paul G

    2009-04-21

    Using a high sensitivity differential scanning calorimeter in isothermal mode, we directly measured heat production in eukaryotic protists from 5 phyla spanning over 5 orders of magnitude in carbon biomass and 8 orders of magnitude in cell volume. Our results reveal that metabolic heat production normalized to cell mass is virtually constant in these organisms, with a median of 0.037 pW pg C(-1) (95% confidence interval = 0.022-0.061 pW pg C(-1)) at 5 degrees C. Contrary to allometric models, the relationship between heat production and cell carbon content or surface area is isometric (scaling exponents, 1.056 and 1.057, respectively). That heat production per unit cell surface area is constant suggests that heat flux through the cell surface is effectively instantaneous, and hence that cells are isothermal with their environment. The results further suggest that allometric models of metabolism based on metazoans are not applicable to protists, and that the underlying metabolic processes in the latter polyphyletic group are highly constrained by evolutionary selection. We propose that the evolutionary constraint leading to a universally constant heat production in single-celled eukaryotes is related to cytoplasmic packaging of organelles and surface area to volume relationships controlling diffusion of resources to these organelles. PMID:19346469

  13. Arkoma exploration heats production builds

    SciTech Connect

    Petzet, G.A.

    1991-01-21

    This paper reports that exploratory drilling continues with fervor to Cambro-Ordovician Arbuckle targets, especially in Arkansas. Pennsylvanian zones continue to yield significant gas discoveries. Gas production from Arkoma basin counties in both states has been rising and stands to climb even further with startup of several new pipelines, assuming gas prices and takes hold up.

  14. Local cloning of two product states

    SciTech Connect

    Ji Zhengfeng; Feng Yuan; Ying Mingsheng

    2005-09-15

    Local quantum operations and classical communication (LOCC) put considerable constraints on many quantum information processing tasks such as cloning and discrimination. Surprisingly, however, discrimination of any two pure states survives such constraints in some sense. We show that cloning is not that lucky; namely, probabilistic LOCC cloning of two product states is strictly less efficient than global cloning. We prove our result by giving explicitly the efficiency formula of local cloning of any two product states.

  15. Single thermal plume in locally heated vertical soap films

    NASA Astrophysics Data System (ADS)

    Adami, N.; Dorbolo, S.; Caps, H.

    2011-10-01

    A vertical soap film is maintained by injection of a soap solution from the top. The film is then locally heated. Thermal plumes may be observed to rise in the film, depending on the magnitude of the heating and injected flows. The nearly two-dimensional nature of the system allows to visualize the motion of the plumes using an infrared camera. A model is proposed to describe the growth, emergence, and stationarity of the plumes in the film by taking into account both magnitudes of the heating ?T and injected flow Q.

  16. Local Modification of Cu Microwires by Joule Heating

    NASA Astrophysics Data System (ADS)

    Tohmyoh, Hironori; Ishihara, Mitsuharu

    2013-07-01

    A technique for modifying the crystalline structure of a metallic microwire is introduced. The technique involves passing current through the wire via two electrical probes causing local Joule heating. We used this technique to heat a 25-m-diameter Cu wire for 1 h at 573 K. The yield stress of the wire after modification was evaluated by a mechanical bending test and it was confirmed that the wire had softened after the process. We also performed heat treatment of a wire in a furnace and the properties of the wires modified by the two different methods were compared.

  17. Endothermic heat production in honeybee winter clusters.

    PubMed

    Stabentheiner, Anton; Pressl, Helga; Papst, Thomas; Hrassnigg, Norbert; Crailsheim, Karl

    2003-01-01

    In order to survive cold northern winters, honeybees crowd tightly together in a winter cluster. Present models of winter cluster thermoregulation consider the insulation by the tightly packed mantle bees as the decisive factor for survival at low temperatures, mostly ignoring the possibility of endothermic heat production. We provide here direct evidence of endothermic heat production by 'shivering' thermogenesis. The abundance of endothermic bees is highest in the core and decreases towards the surface. This shows that core bees play an active role in thermal control of winter clusters. We conclude that regulation of both the insulation by the mantle bees and endothermic heat production by the inner bees is necessary to achieve thermal stability in a winter cluster. PMID:12477904

  18. Locally-smeared operator product expansions

    SciTech Connect

    Monahan, Christopher; Orginos, Kostantinos

    2014-12-01

    We propose a "locally-smeared Operator Product Expansion" (sOPE) to decompose non-local operators in terms of a basis of locally-smeared operators. The sOPE formally connects nonperturbative matrix elements of smeared degrees of freedom, determined numerically using the gradient flow, to non-local operators in the continuum. The nonperturbative matrix elements do not suffer from power-divergent mixing on the lattice, provided the smearing scale is kept fixed in the continuum limit. The presence of this smearing scale prevents a simple connection to the standard operator product expansion and therefore requires the construction of a two-scale formalism. We demonstrate the feasibility of our approach using the example of real scalar field theory.

  19. Conjugate Heat Transfer in a Closed Volume with the Local Heat Sources and Non-Uniform Heat Dissipation on the Boundaries of Heat Conducting Walls

    NASA Astrophysics Data System (ADS)

    Maksimov, Vyacheslav I.; Nagornova, Tatiana A.; Glazyrin, Viktor P.

    2016-02-01

    Is solved the problem of heat transfer in the closed volume, limited by heat-conducting walls, with the local source of heat emission and the heterogeneous conditions of heat sink on the outer boundaries of solution area. The problem of convective heat transfer is solved with using a system of differential Navier-Stokes equations in the Boussinesq approximation. The simulation of turbulent flow conditions of heated air is carried out within the framework to k-ɛ model. On the basis the analysis of the obtained temperature field and the contour lines of stream functions is made conclusion about the essential transiency of the process in question. The obtained values of temperatures and speeds in different sections of region illustrate turbulence of the process. Are investigated laws governing the formation of temperature fields in closed areas with a local heat emission source under the conditions of intensive local heat sink into environment and accumulation of heat in the enclosing constructions.

  20. Local glucocorticoid production in the thymus.

    PubMed

    Talaber, Gergely; Jondal, Mikael; Okret, Sam

    2015-11-01

    Besides generating immunocompetent T lymphocytes, the thymus is an established site of de novo extra-adrenal glucocorticoid (GC) production. Among the compartments of the thymus, both stromal thymic epithelial cells (TECs) and thymocytes secrete biologically active GCs. Locally produced GCs secreted by the various thymic cellular compartments have been suggested to have different impact on thymic homeostasis. TEC-derived GCs may regulate thymocyte differentiation whereas thymocyte-derived GCs might regulate age-dependent involution. However the full biological significance of thymic-derived GCs is still not fully understood. In this review, we summarize and describe recent advances in the understanding of local GC production in the thymus and immunoregulatory steroid production by peripheral T cells and highlight the possible role of local GCs for thymus function. PMID:26102271

  1. Heat production of nursery and growing piglets

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Heat and moisture production (HMP) values are used to size ventilation fans in animal housing. The HMP values that are currently published in the ASABE standards were from data published in 1975. This study is one of a series of studies being conducted to update the HMP values for the ASABE and ASHR...

  2. District heating. Section 2: Products and services

    SciTech Connect

    Not Available

    1991-12-01

    This is a directory of companies providing products and services in the area of district heating. The subheadings of the directory include developers and owner operators, equipment manufacturers, measuring instruments and controls, consulting services, engineering and construction, operation and maintenance, project management, repair, and financial and legal services.

  3. A Production Rule System for Neurological Localization*

    PubMed Central

    Reggia, James A.

    1978-01-01

    A rule-based program for localization of damage to the central nervous system was developed to evaluate MYCIN-like production system methodology. The program uses the results of the neurological examination of unconscious patients to categorize them in a manner familiar to clinicians. A collection of rules was found to be a poor representation for neurological localization knowledge because such information is conceptually organized in a frame-like fashion and is very context-dependent. Rule understandability was improved through the use of “macropredicates” and by the development of a natural inference hierarchy. The role of production systems as a model of human cognition is discussed.

  4. Localized electron heating by strong guide-field magnetic reconnection

    NASA Astrophysics Data System (ADS)

    Guo, Xuehan; Inomoto, Michiaki; Sugawara, Takumichi; Yamasaki, Kotaro; Ushiki, Tomohiko; Ono, Yasushi

    2015-10-01

    Localized electron heating of magnetic reconnection was studied under strong guide-field using two merging spherical tokamak plasmas in the University of Tokyo Spherical Tokamak experiment. Our new slide-type two-dimensional Thomson scattering system is documented for the first time the electron heating localized around the X-point. Shape of the high electron temperature area does not agree with that of energy dissipation term Et.jt . If we include a guide-field effect term Bt/(Bp+αBt) for Et.jt , the energy dissipation area becomes localized around the X-point, suggesting that the electrons are accelerated by the reconnection electric field parallel to the magnetic field and thermalized around the X-point.

  5. Local indistinguishability of orthogonal product states

    NASA Astrophysics Data System (ADS)

    Zhang, Zhi-Chao; Gao, Fei; Cao, Ya; Qin, Su-Juan; Wen, Qiao-Yan

    2016-01-01

    In the general bipartite quantum system m ?n (m ,n ?3 ) , Y.-L. Wang et al. [Phys. Rev. A 92, 032313 (2015)], 10.1103/PhysRevA.92.032313 presented 3 (m +n )-9 orthogonal product states which cannot be distinguished by local operations and classical communication (LOCC). In this paper, we aim to construct less locally indistinguishable orthogonal product states in m ?n . First, in the 3 ?n (3 locally indistinguishable orthogonal product states which are not unextendible product bases. Then, for m ?n (4 ?m ?n ) , we present 3 n +m -4 orthogonal product states which cannot be perfectly distinguished by LOCC. Finally, in the general bipartite quantum system m ?n (3 ?m ?n ) , we show a smaller set with 2 n -1 orthogonal product states and prove that these states are LOCC indistinguishable using a very simple but quite effective method. All of the above results demonstrate the phenomenon of nonlocality without entanglement.

  6. Local and non-local correlations for critical heat flux at low and medium pressures

    SciTech Connect

    Jafri, T.; Dougherty, T.J.; Yang, B.W.

    1996-12-31

    The local and non-local correlations developed based on more than 10,000 Critical Heat Flux (CHF) data points are reviewed and the effects of the pressure and Peclet number are examined under low and medium pressure conditions (up to 110 bar). Examination of CHF data from many sources covering a wide range of operating conditions, reveals that both local and non-local CHF data exist with different dependencies on operating conditions, and different correlations are required to represent these data. These two distinct types of correlations imply the existence of at least two distinct mechanisms for CHF.

  7. Characterization of local heat fluxes around ICRF antennas on JET

    SciTech Connect

    Campergue, A.-L.; Jacquet, P.; Monakhov, I.; Arnoux, G.; Brix, M.; Sirinelli, A.; Milanesio, D.; Colas, L.; Collaboration: JET-EFDA Contributors

    2014-02-12

    When using Ion Cyclotron Range of Frequency (ICRF) heating, enhanced power deposition on Plasma-Facing Components (PFCs) close to the antennas can occur. Experiments have recently been carried out on JET with the new ITER-Like-Wall (ILW) to characterize the heat fluxes on the protection of the JET ICRF antennas, using Infra-Red (IR) thermography measurement. The measured heat flux patterns along the poloidal limiters surrounding powered antennas were compared to predictions from a simple RF sheath rectification model. The RF electric field, parallel to the static magnetic field in front of the antenna, was evaluated using the TOPICA code, integrating a 3D flattened model of the JET A2 antennas. The poloidal density variation in front of the limiters was obtained from the mapping of the Li-beam or edge reflectometry measurements using the flux surface geometry provided by EFIT equilibrium reconstruction. In many cases, this simple model can well explain the position of the maximum heat flux on the different protection limiters and the heat-flux magnitude, confirming that the parallel RF electric field and the electron plasma density in front of the antenna are the main driving parameters for ICRF-induced local heat fluxes.

  8. Effects of gas bubble production on heat transfer from a volumetrically heated liquid pool

    NASA Astrophysics Data System (ADS)

    Bull, Geoffrey R.

    Aqueous solutions of uranium salts may provide a new supply chain to fill potential shortfalls in the availability of the most common radiopharmaceuticals currently in use worldwide, including Tc99m which is a decay product of Mo99. The fissioning of the uranium in these solutions creates Mo99 but also generates large amounts of hydrogen and oxygen from the radiolysis of the water. When the dissolved gases reach a critical concentration, bubbles will form in the solution. Bubbles in the solution affect both the fission power and the heat transfer out of the solution. As a result, for safety and production calculations, the effects of the bubbles on heat transfer must be understood. A high aspect ratio tank was constructed to simulate a section of an annulus with heat exchangers on the inner and outer steel walls to provide cooling. Temperature measurements via thermocouples inside the tank and along the outside of the steel walls allowed the calculation of overall and local heat transfer coefficients. Different air injection manifolds allowed the exploration of various bubble characteristics and patterns on heat transfer from the pool. The manifold type did not appear to have significant impact on the bubble size distributions in water. However, air injected into solutions of magnesium sulfate resulted in smaller bubble sizes and larger void fractions than those in water at the same injection rates. One dimensional calculations provide heat transfer coefficient values as functions of the superficial gas velocity in the pool.

  9. Local Heat Transfer for Finned-Tube Heat Exchangers using Oval Tubes

    SciTech Connect

    O'Brien, James Edward; Sohal, Manohar Singh

    2000-08-01

    This paper presents the results of an experimental study of forced convection heat transfer in a narrow rectangular duct fitted with either a circular tube or an elliptical tube in crossflow. The duct was designed to simulate a single passage in a fin-tube heat exchanger. Heat transfer measurements were obtained using a transient technique in which a heated airflow is suddenly introduced to the test section. High-resolution local fin-surface temperature distributions were obtained at several times after initiation of the transient using an imaging infrared camera. Corresponding local fin-surface heat transfer coefficient distributions were then calculated from a locally applied one-dimensional semi-infinite inverse heat conduction model. Heat transfer results were obtained over an airflow rate ranging from 1.56 x 10-3 to 15.6 x 10-3 kg/s. These flow rates correspond to a duct-height Reynolds number range of 630 – 6300 with a duct height of 1.106 cm and a duct width-toheight ratio, W/H, of 11.25. The test cylinder was sized such that the diameter-to-duct height ratio, D/H is 5. The elliptical tube had an aspect ratio of 3:1 and a/H equal to 4.33. Results presented in this paper reveal visual and quantitative details of local fin-surface heat transfer distributions in the vicinity of circular and oval tubes and their relationship to the complex horseshoe vortex system that forms in the flow stagnation region. Fin surface stagnation-region Nusselt numbers are shown to be proportional to the square-root of Reynolds number.

  10. Local and Nonlocal Parallel Heat Transport in General Magnetic Fields

    SciTech Connect

    Castillo-Negrete, D. del; Chacon, L.

    2011-05-13

    A novel approach for the study of parallel transport in magnetized plasmas is presented. The method avoids numerical pollution issues of grid-based formulations and applies to integrable and chaotic magnetic fields with local or nonlocal parallel closures. In weakly chaotic fields, the method gives the fractal structure of the devil's staircase radial temperature profile. In fully chaotic fields, the temperature exhibits self-similar spatiotemporal evolution with a stretched-exponential scaling function for local closures and an algebraically decaying one for nonlocal closures. It is shown that, for both closures, the effective radial heat transport is incompatible with the quasilinear diffusion model.

  11. Local and nonlocal parallel heat transport in general magnetic fields

    SciTech Connect

    Del-Castillo-Negrete, Diego B; Chacon, Luis

    2011-01-01

    A novel approach for the study of parallel transport in magnetized plasmas is presented. The method avoids numerical pollution issues of grid-based formulations and applies to integrable and chaotic magnetic fields with local or nonlocal parallel closures. In weakly chaotic fields, the method gives the fractal structure of the devil's staircase radial temperature profile. In fully chaotic fields, the temperature exhibits self-similar spatiotemporal evolution with a stretched-exponential scaling function for local closures and an algebraically decaying one for nonlocal closures. It is shown that, for both closures, the effective radial heat transport is incompatible with the quasilinear diffusion model.

  12. Local Heat Flux Measurements with Single Element Coaxial Injectors

    NASA Technical Reports Server (NTRS)

    Jones, Gregg; Protz, Christopher; Bullard, Brad; Hulka, James

    2006-01-01

    To support the mission for the NASA Vision for Space Exploration, the NASA Marshall Space Flight Center conducted a program in 2005 to improve the capability to predict local thermal compatibility and heat transfer in liquid propellant rocket engine combustion devices. The ultimate objective was to predict and hence reduce the local peak heat flux due to injector design, resulting in a significant improvement in overall engine reliability and durability. Such analyses are applicable to combustion devices in booster, upper stage, and in-space engines, as well as for small thrusters with few elements in the injector. In this program, single element and three-element injectors were hot-fire tested with liquid oxygen and ambient temperature gaseous hydrogen propellants at The Pennsylvania State University Cryogenic Combustor Laboratory from May to August 2005. Local heat fluxes were measured in a 1-inch internal diameter heat sink combustion chamber using Medtherm coaxial thermocouples and Gardon heat flux gauges. Injectors were tested with shear coaxial and swirl coaxial elements, including recessed, flush and scarfed oxidizer post configurations, and concentric and non-concentric fuel annuli. This paper includes general descriptions of the experimental hardware, instrumentation, and results of the hot-fire testing for three of the single element injectors - recessed-post shear coaxial with concentric fuel, flush-post swirl coaxial with concentric fuel, and scarfed-post swirl coaxial with concentric fuel. Detailed geometry and test results will be published elsewhere to provide well-defined data sets for injector development and model validatation.

  13. Thermal plumes in locally heated vertical soap films

    NASA Astrophysics Data System (ADS)

    Adami, Nicolas; Dorbolo, Stphane; Caps, Herv.

    2012-02-01

    A vertical soap film is maintained by injection of a soap solution from the top. The film is then locally heated. Thermal plumes may be observed to rise in the film, depending on the magnitude of the heating and injected flows. The nearly-2D nature of the system allows to visualize the motion of the plumes using an infrared camera. A model is proposed to describe the growth, emergence, and stationarity of the plumes in the film by taking into account both magnitudes of the heating ?T and injected flow Q. Oscillatory behaviors of both the full-grown plumes size and direction with respect to the vertical direction may also be observed. Particular soap film thickness dynamics shows to be the origin of those phenomena.

  14. Nickel foil microcantilevers for magnetic manipulation and localized heating

    PubMed Central

    Gaitas, Angelo; McNaughton, Brandon H.

    2014-01-01

    Cellular manipulation has been investigated by a number of techniques. In this manuscript nickel foil microcantilevers were used for magnetophoresis and manipulation of microparticles and magnetically labeled HeLa cells. The cantilevers were also used for localized heating in liquid, reaching biologically relevant temperatures. This work aims to develop cantilevers for sample enrichment, manipulation, and thermal applications, offering an inexpensive and versatile solution compatible with standard tools in research and clinical diagnostic testing, such as microwell plates. PMID:25541581

  15. Determinants of heat production in newborn lambs

    NASA Astrophysics Data System (ADS)

    Eales, F. A.; Small, J.

    1980-06-01

    Measurement of summit metabolism (the maximum rate of heat production) in lambs aged 1 or 4h revealed considerable between animal variation. Summit metabolism per unit body weight decreased as body weight increased whereas summit metabolism per unit body surface area was independent of body weight. Severe pre-partum hypoxia was apparently associated with a low summit metabolism at 1 or 4h of age which made such lambs very susceptible to hypothermia. This deficiency in heat production capacity did not appear to be a permanent featuresince most lambs so affected recovered full thermoregulatory ability by 12h of age. Feeding of colostrum conferred an immediate 18% increase in summit metabolism. The significance of these findings to the prevention of hypothermia in the newborn lamb is discussed.

  16. Preheated autologous serum skin test in localized heat urticaria.

    PubMed

    Pezzolo, E; Peroni, A; Schena, D; Girolomoni, G

    2014-12-01

    Localized heat urticaria (LHU) is a rare type of physical urticaria, characterized by itching and erythema and well-demarcated weals, appearing withinminutes at heat-exposed body sites. Its pathogenesis has not yet been clarified. We report the case of a 46-year-old woman with a generalized form of LHU, which was induced by exposure to warm baths, and consumption of warm food and drinks. Weal reaction was obtained 10min after application of a metal cylinder heated to 43C. Interestingly, only serum previously heated to 56C and injected intradermally for autologous serum skin test induced a weal and flare reaction, whereas serum preheated to 45C did not induce any reaction. Our patient did not respond to high-dose antihistamines, and refused a heat desensitization programme. Treatment with colchicine 1mg/day or ciclosporin A 3.5mg/kg/day for 1month yielded no improvement. Mild improvement was obtained with intramuscular injection of triamcinolone acetonide 40mg every 2weeks for 2months. PMID:25283603

  17. Experimental and theoretical analysis of the local condensation heat transfer in a plate heat exchanger

    NASA Astrophysics Data System (ADS)

    Grabenstein, V.; Kabelac, S.

    2012-11-01

    Plate heat exchanger (PHE) are today widely used in industrial heat transfer applications due to their good thermal performance, modest space requirement, easy accessibility to all areas and their lower capital and operating costs as compared to shell-and-tube heat exchangers. Although authoritative models for the design of PHE used as condensers are missing, the number of applications where a PHE is operating as a condenser increases. On the way to a reliable model based on physical approaches for the prediction of heat transfer and pressure drop during the condensation process inside a PHE, the flow and heat interactions as well as their dependence on the geometrical parameters of the corrugated plates and the operating conditions must be studied in detail. In this work the stepwise procedure for the fundamental construction of such a model is described. An experimental setup was built to analyze the characteristics of the two-phase-flow in PHE. A single gap, consisting of two transparent corrugated plates, was tested with a two-phase flow of air/water and also with boiling refrigerant R365mfc. Flow pattern maps were constructed for plates with corrugation angles of 27 and 63 degrees relative to the direction of flow. Investigations of the local heat transfer coefficients and the pressure drop were done with the same plates. The measurement of the local heat transfer coefficients was carried out by the use of the "Temperature Oscillation InfraRed Thermography" (TOIRT) method. Based on these results three main flow patterns are defined: film flow, bubbly flow and slug flow. For each of the three flow patterns an own model for the heat transfer and pressure drop mechanism are developed and the heat transfer coefficient and the friction factor is calculated with different equations depending on the actual steam quality, mass flow and geometrical parameters by means of a flow pattern map. The theory of the flow pattern based prediction models is proved with own experimental data. The measurements were carried out with an experimental setup in a technical scale. The refrigerant cycle works with R134a as refrigerant and involves two PHEs, used as condenser and evaporator, and a 55 kWel compressor for the compression of the vapor phase. The setup allows the measurement of quasi-local heat transfer coefficients inside the PHEs. Additional heat exchangers assure saturated vapor at the inlet and saturated liquid at the outlet of the condenser.

  18. Localized tidal heating in icy shells of variable thickness

    NASA Astrophysics Data System (ADS)

    Beuthe, M.

    2013-09-01

    Several icy bodies are suspected to harbour an ocean beneath their surface icy shell. Candidates include Europa, Ganymede, Callisto, Titan, Enceladus, Triton and Pluto. Though the mean shell thickness is the quantity of primary interest, determining thickness variations is also useful to predict tectonics [1], long-wavelength topography [2, 3] or the rotational state of the body [4]. Variations in shell thickness are due to nonuniform solar insolation and internal heating. In particular, diurnal tides periodically deform the icy shell causing friction that heats the shell from within. Dissipation is much higher at the poles than at the equator and generates shell thickness variations if tides are large enough. This could be the case for Europa, Enceladus and Titan. In turn, tidal stresses and strains are modified by shell thickness variations so that there is a feedback loop between tidal dissipation and shell thickness. Using the 2D formalism of thin spherical shells, I investigate the interaction between shell thickness and tidal heating, which results in enhanced localized heating and stresses.

  19. Non-Heat Treatable Alloy Sheet Products

    SciTech Connect

    Hayden, H.W.; Barthold, G.W.; Das, S.K.

    1999-08-01

    ALCAR is an innovative approach for conducting multi-company, pre-competitive research and development programs. ALCAR has been formed to crate a partnership of aluminum producers, the American Society of Mechanical Engineers Center for Research and Technology Development (ASME/CRTD), the United States Department of Energy (USDOE), three USDOE National Laboratories, and a Technical Advisory Committee for conducting cooperative, pre-competitive research on the development of flower-cost, non-heat treated (NHT) aluminum alloys for automotive sheet applications with strength, formability and surface appearance similar to current heat treated (HT) aluminum alloys under consideration. The effort has been supported by the USDOE, Office of Transportation Technology (OTT) through a three-year program with 50/50 cost share at a total program cost of $3 million. The program has led to the development of new and modified 5000 series aluminum ally compositions. Pilot production-size ingots have bee n melted, cast, hot rolled and cold rolled. Stamping trials on samples of rolled product for demonstrating production of typical automotive components have been successful.

  20. Thermoviscoplastic response of thin plates subjected to intense local heating

    NASA Technical Reports Server (NTRS)

    Byrom, Ted G.; Allen, David H.; Thornton, Earl A.

    1992-01-01

    A finite element method is employed to investigate the thermoviscoplastic response of a half-cylinder to intense localized transient heating. Thermoviscoplastic material behavior is characterized by the Bodner-Partom constitutive model. Structure geometry is modeled with a three-dimensional assembly of CST-DKT plate elements incorporating the large deflection von Karman assumptions. The paper compares the results of a dynamic analysis with a quasi-static analysis for the half-cylinder structure with a step-function transient temperature loading similar to that which may be encountered with shock wave interference on a hypersonic leading edge.

  1. Numerical and experimental study of local heat transfer enhancement in helically coiled pipes. Preliminary results.

    NASA Astrophysics Data System (ADS)

    Bozzoli, F.; Cattani, L.; Rainieri, S.; Zachár, A.

    2015-11-01

    In the last years, the attention of heat transfer equipments manufacturers turned toward helically coiled-tube heat exchangers, especially with regards to applications for viscous and/or particulate products. The recent progress achieved in numerical simulation motivated many research groups to develop numerical models for this kind of apparatuses. These models, intended both to improve the knowledge of the fundamental heat transfer mechanisms in curved geometries and to support the industrial design of this kind of apparatuses, are usually validated throughout the comparison with either theoretical or experimental evidences by considering average heat transfer performances. However, this approach doesn't guarantee that the validated models are able to reproduce local effects in details, which are so important in this kind of non-standard geometries. In the present paper a numerical model of convective heat transfer in coiled tubes for laminar flow regime was formulated and discussed. Its goodness was checked throughout the comparison with the latest experimental outcomes of Bozzoli et al. [1] in terms of convective heat flux distribution along the boundary of the duct, by ensuring the effectiveness of the model also in the description of local behaviours. Although the present paper reports only preliminary results of this simulation/validation process, it could be of interest for the research community because it proposes a novel approach that could be useful to validate many numerical models for nonstandard geometries.

  2. Local infusion of ascorbate augments NO-dependent cutaneous vasodilatation during intense exercise in the heat.

    PubMed

    Meade, Robert D; Fujii, Naoto; Alexander, Lacy M; Paull, Gabrielle; Louie, Jeffrey C; Flouris, Andreas D; Kenny, Glen P

    2015-09-01

    Recent work demonstrates that nitric oxide (NO) contributes to cutaneous vasodilatation during moderate (400 W of metabolic heat production) but not high (700 W of metabolic heat production) intensity exercise bouts performed in the heat (35C). The present study evaluated whether the impairment in NO-dependent cutaneous vasodilatation was the result of a greater accumulation of reactive oxygen species during high (700 W of metabolic heat production) relative to moderate (500 W of metabolic heat production) intensity exercise. It was shown that local infusion of ascorbate (an anti-oxidant) improves NO-dependent forearm cutaneous vasodilatation during high intensity exercise in the heat. These findings provide novel insight into the physiological mechanisms governing cutaneous blood flow during exercise-induced heat stress and provide direction for future research exploring whether oxidative stress underlies the impairments in heat dissipation that may occur in older adults, as well as in individuals with pathophysiological conditions such as type 2 diabetes. Nitric oxide (NO)-dependent cutaneous vasodilatation is reportedly diminished during exercise performed at a high (700 W) relative to moderate (400 W) rate of metabolic heat production. The present study evaluated whether this impairment results from increased oxidative stress associated with an accumulation of reactive oxygen species (ROS) during high intensity exercise. On two separate days, 11 young (mean SD, 24 4 years) males cycled in the heat (35C) at a moderate (500 W) or high (700 W) rate of metabolic heat production. Each session included two 30 min exercise bouts followed by 20 and 40 min of recovery, respectively. Cutaneous vascular conductance (CVC) was monitored at four forearm skin sites continuously perfused via intradermal microdialysis with: (1) lactated Ringer solution (Control); (2) 10 mm ascorbate (Ascorbate); (3) 10 mm l-NAME; or (4) 10 mm ascorbate + 10 mm l-NAME (Ascorbate + l-NAME). At the end of each 500 W exercise bout, CVC was attenuated with l-NAME (?35% CVCmax ) and Ascorbate + l-NAME (?43% CVCmax ) compared to Control (?60% CVCmax ; all P < 0.04); however, Ascorbate did not modulate CVC during exercise (?60% CVCmax ; both P > 0.87). Conversely, CVC was elevated with Ascorbate (?72% CVCmax ; both P < 0.03) but remained similar to Control (?59% CVCmax ) with l-NAME (?50% CVCmax ) and Ascorbate + l-NAME (?47% CVCmax ; all P > 0.05) at the end of both 700 W exercise bouts. We conclude that oxidative stress associated with an accumulation of ascorbate-sensitive ROS impairs NO-dependent cutaneous vasodilatation during intense exercise. PMID:26110415

  3. Transient response to localized episodic heating in the tropics

    NASA Technical Reports Server (NTRS)

    Salby, M. L.; Garcia, R. R.

    1985-01-01

    It is generally recognized that equatorial disturbances in the lower stratosphere are excited by convective latent heat release associated with the Internal Tropical Convergence Zone (ITCZ). Recently, attention has also focused on tropical convection with regard to extratropical teleconnection patterns. Unlike equatorial waves which are trapped about the equator but propagate vertically, the latter extend well out of the tropics but are barotropic. They have been most widely discussed in connection with long-term climatological features. Both types of disturbances have been examined largely from the standpoint of steady monochromatic forcing, in the latter case zero frequency or time-mean heating. However, tropical convection as revealed by recent geostationary satellite imagery is anything but regular, surely not steady. Much of the heating variance is concentrated spatially within three localized convective centers: Indonesia, the Amazon, and the Congo. Convective activity within these regions undergoes an irregular evolution over the span of a couple of days. It involves a rather broad spectrum of spatial and temporal scales. The analysis of cloud brightness over the Eastern Atlantic and Africa suggests a characteristic time scale of 3-4 days and correlations scales in latitude and longitude of approximately 30 deg.

  4. Thermal balance and quantum heat transport in nanostructures thermalized by local Langevin heat baths

    NASA Astrophysics Data System (ADS)

    Sskilahti, K.; Oksanen, J.; Tulkki, J.

    2013-07-01

    Modeling of thermal transport in practical nanostructures requires making tradeoffs between the size of the system and the completeness of the model. We study quantum heat transfer in a self-consistent thermal bath setup consisting of two lead regions connected by a center region. Atoms both in the leads and in the center region are coupled to quantum Langevin heat baths that mimic the damping and dephasing of phonon waves by anharmonic scattering. This approach treats the leads and the center region on the same footing and thereby allows for a simple and physically transparent thermalization of the system, enabling also perfect acoustic matching between the leads and the center region. Increasing the strength of the coupling reduces the mean-free path of phonons and gradually shifts phonon transport from ballistic regime to diffusive regime. In the center region, the bath temperatures are determined self-consistently from the requirement of zero net energy exchange between the local heat bath and each atom. By solving the stochastic equations of motion in frequency space and averaging over noise using the general fluctuation-dissipation relation derived by Dhar and Roy [J. Stat. Phys.JSTPBS0022-471510.1007/s10955-006-9235-3 125, 801 (2006)], we derive the formula for thermal current, which contains the Caroli formula for phonon transmission function and reduces to the Landauer-Bttiker formula in the limit of vanishing coupling to local heat baths. We prove that the bath temperatures measure local kinetic energy and can, therefore, be interpreted as true atomic temperatures. In a setup where phonon reflections are eliminated, the Boltzmann transport equation under gray approximation with full phonon dispersion is shown to be equivalent to the self-consistent heat bath model. We also study thermal transport through two-dimensional constrictions in square lattice and graphene and discuss the differences between the exact solution and linear approximations.

  5. Thermal balance and quantum heat transport in nanostructures thermalized by local Langevin heat baths.

    PubMed

    Sskilahti, K; Oksanen, J; Tulkki, J

    2013-07-01

    Modeling of thermal transport in practical nanostructures requires making tradeoffs between the size of the system and the completeness of the model. We study quantum heat transfer in a self-consistent thermal bath setup consisting of two lead regions connected by a center region. Atoms both in the leads and in the center region are coupled to quantum Langevin heat baths that mimic the damping and dephasing of phonon waves by anharmonic scattering. This approach treats the leads and the center region on the same footing and thereby allows for a simple and physically transparent thermalization of the system, enabling also perfect acoustic matching between the leads and the center region. Increasing the strength of the coupling reduces the mean-free path of phonons and gradually shifts phonon transport from ballistic regime to diffusive regime. In the center region, the bath temperatures are determined self-consistently from the requirement of zero net energy exchange between the local heat bath and each atom. By solving the stochastic equations of motion in frequency space and averaging over noise using the general fluctuation-dissipation relation derived by Dhar and Roy [J. Stat. Phys. 125, 801 (2006)], we derive the formula for thermal current, which contains the Caroli formula for phonon transmission function and reduces to the Landauer-Bttiker formula in the limit of vanishing coupling to local heat baths. We prove that the bath temperatures measure local kinetic energy and can, therefore, be interpreted as true atomic temperatures. In a setup where phonon reflections are eliminated, the Boltzmann transport equation under gray approximation with full phonon dispersion is shown to be equivalent to the self-consistent heat bath model. We also study thermal transport through two-dimensional constrictions in square lattice and graphene and discuss the differences between the exact solution and linear approximations. PMID:23944435

  6. Strong contributions of local background climate to urban heat islands.

    PubMed

    Zhao, Lei; Lee, Xuhui; Smith, Ronald B; Oleson, Keith

    2014-07-10

    The urban heat island (UHI), a common phenomenon in which surface temperatures are higher in urban areas than in surrounding rural areas, represents one of the most significant human-induced changes to Earth's surface climate. Even though they are localized hotspots in the landscape, UHIs have a profound impact on the lives of urban residents, who comprise more than half of the world's population. A barrier to UHI mitigation is the lack of quantitative attribution of the various contributions to UHI intensity (expressed as the temperature difference between urban and rural areas, ?T). A common perception is that reduction in evaporative cooling in urban land is the dominant driver of ?T (ref. 5). Here we use a climate model to show that, for cities across North America, geographic variations in daytime ?T are largely explained by variations in the efficiency with which urban and rural areas convect heat to the lower atmosphere. If urban areas are aerodynamically smoother than surrounding rural areas, urban heat dissipation is relatively less efficient and urban warming occurs (and vice versa). This convection effect depends on the local background climate, increasing daytime ?T by 3.00.3kelvin (mean and standard error) in humid climates but decreasing ?T by 1.50.2kelvin in dry climates. In the humid eastern United States, there is evidence of higher ?T in drier years. These relationships imply that UHIs will exacerbate heatwave stress on human health in wet climates where high temperature effects are already compounded by high air humidity and in drier years when positive temperature anomalies may be reinforced by a precipitation-temperature feedback. Our results support albedo management as a viable means of reducing ?T on large scales. PMID:25008529

  7. Strong contributions of local background climate to urban heat islands

    NASA Astrophysics Data System (ADS)

    Zhao, Lei; Lee, Xuhui; Smith, Ronald B.; Oleson, Keith

    2014-07-01

    The urban heat island (UHI), a common phenomenon in which surface temperatures are higher in urban areas than in surrounding rural areas, represents one of the most significant human-induced changes to Earth's surface climate. Even though they are localized hotspots in the landscape, UHIs have a profound impact on the lives of urban residents, who comprise more than half of the world's population. A barrier to UHI mitigation is the lack of quantitative attribution of the various contributions to UHI intensity (expressed as the temperature difference between urban and rural areas, ?T). A common perception is that reduction in evaporative cooling in urban land is the dominant driver of ?T (ref. 5). Here we use a climate model to show that, for cities across North America, geographic variations in daytime ?T are largely explained by variations in the efficiency with which urban and rural areas convect heat to the lower atmosphere. If urban areas are aerodynamically smoother than surrounding rural areas, urban heat dissipation is relatively less efficient and urban warming occurs (and vice versa). This convection effect depends on the local background climate, increasing daytime ?T by 3.0 +/- 0.3 kelvin (mean and standard error) in humid climates but decreasing ?T by 1.5 +/- 0.2 kelvin in dry climates. In the humid eastern United States, there is evidence of higher ?T in drier years. These relationships imply that UHIs will exacerbate heatwave stress on human health in wet climates where high temperature effects are already compounded by high air humidity and in drier years when positive temperature anomalies may be reinforced by a precipitation-temperature feedback. Our results support albedo management as a viable means of reducing ?T on large scales.

  8. Homogeneous Thermal Cloak with Constant Conductivity and Tunable Heat Localization

    PubMed Central

    Han, Tiancheng; Yuan, Tao; Li, Baowen; Qiu, Cheng-Wei

    2013-01-01

    Invisible cloak has long captivated the popular conjecture and attracted intensive research in various communities of wave dynamics, e.g., optics, electromagnetics, acoustics, etc. However, their inhomogeneous and extreme parameters imposed by transformation-optic method will usually require challenging realization with metamaterials, resulting in narrow bandwidth, loss, polarization-dependence, etc. In this paper, we demonstrate that thermodynamic cloak can be achieved with homogeneous and finite conductivity only employing naturally available materials. It is demonstrated that the thermal localization inside the coating layer can be tuned and controlled robustly by anisotropy, which enables an incomplete cloak to function perfectly. Practical realization of such homogeneous thermal cloak has been suggested by using two naturally occurring conductive materials, which provides an unprecedentedly plausible way to flexibly realize thermal cloak and manipulate heat flow with phonons. PMID:23549139

  9. Local thermodynamic equilibrium in rapidly heated high energy density plasmas

    SciTech Connect

    Aslanyan, V.; Tallents, G. J.

    2014-06-15

    Emission spectra and the dynamics of high energy density plasmas created by optical and Free Electron Lasers (FELs) depend on the populations of atomic levels. Calculations of plasma emission and ionization may be simplified by assuming Local Thermodynamic Equilibrium (LTE), where populations are given by the Saha-Boltzmann equation. LTE can be achieved at high densities when collisional processes are much more significant than radiative processes, but may not be valid if plasma conditions change rapidly. A collisional-radiative model has been used to calculate the times taken by carbon and iron plasmas to reach LTE at varying densities and heating rates. The effect of different energy deposition methods, as well as Ionization Potential Depression are explored. This work shows regimes in rapidly changing plasmas, such as those created by optical lasers and FELs, where the use of LTE is justified, because timescales for plasma changes are significantly longer than the times needed to achieve an LTE ionization balance.

  10. Localized bending and heating at Enceladus' south pole

    NASA Astrophysics Data System (ADS)

    Beuthe, M.

    2015-10-01

    Since the discovery in 2005 of geysers at the southpole of Enceladus, this midsize moon of Saturn has become famous as the most active icy world in the solar system and as a potential harbor for microbial life. All data gathered during flybys by the Cassini probe point to the existence of a subsurface ocean maintained by tidal heating in the icy crust. This explanation, however, is in conflict with geophysical models which only account for a tenth of the heat output. Such models are based on an approach designed for larger satellites, for which elastic effects are weaker and lateral inhomogeneities are less prominent. By contrast, lateral variations of interior structure are probably the key to understand Enceladus' geological activity. We will test the hypothesis that tidal dissipation is greatly enhanced by local bending of a thinner crust in the south polar region. More generally, we plan to develop a new and faster method to compute tidal dis-sipation in small bodies with lateral heterogeneities,consisting in modeling the crust as a two-dimensional spherical shell with variable thickness or rigidity and with depth-dependent rheology.

  11. Heat production in an Archean crustal profile and implications for heat flow and mobilization of heat-producing elements

    NASA Technical Reports Server (NTRS)

    Ashwal, L. D.; Morgan, P.; Kelley, S. A.; Percival, J. A.

    1987-01-01

    Concentrations of heat producing elements (Th, U, and K) in 58 samples representative of the main lithologies in a 100-km transect of the Superior Province of the Canadian Shield have been obtained. The relatively large variation in heat production found among the silicic plutonic rocks is shown to correlate with modal abundances of accessory minerals, and these variations are interpreted as premetamorphic. The present data suggest fundamental differences in crustal radioactivity distributions between granitic and more mafic terrains, and indicate that a previously determined apparently linear heat flow-heat production relationship for the Kapuskasing area does not relate to the distribution of heat production with depth.

  12. Technologies for Production of Heat and Electricity

    SciTech Connect

    Jacob J. Jacobson; Kara G. Cafferty

    2014-04-01

    Biomass is a desirable source of energy because it is renewable, sustainable, widely available throughout the world, and amenable to conversion. Biomass is composed of cellulose, hemicellulose, and lignin components. Cellulose is generally the dominant fraction, representing about 40 to 50% of the material by weight, with hemicellulose representing 20 to 50% of the material, and lignin making up the remaining portion [4,5,6]. Although the outward appearance of the various forms of cellulosic biomass, such as wood, grass, municipal solid waste (MSW), or agricultural residues, is different, all of these materials have a similar cellulosic composition. Elementally, however, biomass varies considerably, thereby presenting technical challenges at virtually every phase of its conversion to useful energy forms and products. Despite the variances among cellulosic sources, there are a variety of technologies for converting biomass into energy. These technologies are generally divided into two groups: biochemical (biological-based) and thermochemical (heat-based) conversion processes. This chapter reviews the specific technologies that can be used to convert biomass to energy. Each technology review includes the description of the process, and the positive and negative aspects.

  13. Heat Transfer and Fluid Transport of Supercritical CO2 in Enhanced Geothermal System with Local Thermal Non-equilibrium Model

    DOE PAGESBeta

    Zhang, Le; Luo, Feng; Xu, Ruina; Jiang, Peixue; Liu, Huihai

    2014-12-31

    The heat transfer and fluid transport of supercritical CO2 in enhanced geothermal system (EGS) is studied numerically with local thermal non-equilibrium model, which accounts for the temperature difference between solid matrix and fluid components in porous media and uses two energy equations to describe heat transfer in the solid matrix and in the fluid, respectively. As compared with the previous results of our research group, the effect of local thermal non-equilibrium mainly depends on the volumetric heat transfer coefficient ah, which has a significant effect on the production temperature at reservoir outlet and thermal breakthrough time. The uniformity of volumetricmore » heat transfer coefficient ah has little influence on the thermal breakthrough time, but the temperature difference become more obvious with time after thermal breakthrough with this simulation model. The thermal breakthrough time reduces and the effect of local thermal non-equilibrium becomes significant with decreasing ah.« less

  14. An evaluation of local heating as a means of fuel evaporation for gasoline engines

    SciTech Connect

    Aquino, C.; Plensdorf, W.D.

    1986-01-01

    The technique of evaporating fuel by localized heating before entering the intake manifold is evaluated as a means of improving A/F ratio control. Techniques currently in use are briefly discussed, and attempts to analyze fuel evaporation in S.I. engines are reviewed. A test fixture which includes all the essential features of production feasible hardware is used to develop a basis of understanding for the evaporation process. Tests are conducted on a flow bench using water as ''fuel,'' and on an engine using isooctane and gasoline. A heat-mass transfer analogy is described and used to predict evaporation rates for water and isooctane. Predicted and measured rates are compared for both bench and engine tests. Engine tests with gasoline show the ability of the test configuration to evaporate all part throttle fuel flow before it enters the intake manifold. Results are presented which show the ability of local heating to reduce A/F excursions on the 1.6 Liter engine by 80% over the ambient temperature range of 0/sup 0/F to 70/sup 0/F. Results showing the elimination of cylinder to cylinder A/F maldistribution are presented, and recommended operating temperatures and heat inputs for engine operation are also presented.

  15. Future crop production threatened by extreme heat

    NASA Astrophysics Data System (ADS)

    Siebert, Stefan; Ewert, Frank

    2014-04-01

    Heat is considered to be a major stress limiting crop growth and yields. While important findings on the impact of heat on crop yield have been made based on experiments in controlled environments, little is known about the effects under field conditions at larger scales. The study of Deryng et al (2014 Global crop yield response to extreme heat stress under multiple climate change futures Environ. Res. Lett. 9 034011), analysing the impact of heat stress on maize, spring wheat and soya bean under climate change, represents an important contribution to this emerging research field. Uncertainties in the occurrence of heat stress under field conditions, plant responses to heat and appropriate adaptation measures still need further investigation.

  16. Adapting poultry production to solar heat

    SciTech Connect

    Not Available

    1982-12-15

    During 1982 a floor heating system has been installed in a 40 ft. x 300 ft. chicken house (15,000 birds). The floor heating system consists of EPDM synthetic rubber tubing buried in a 4-inch concrete slab. Hot water is supplied to the tubing from a 4000 gallon storage tank which is insulated and buried outside the chicken house. The storage tank is heated by 24 solar collectors which are ground mounted on the south side of the chicken house. A propane fired boiler is in line between the storage tank and the floor. The boiler adds heat to the water entering the floor if the water is not hot enough.

  17. Local electron heating in the Io plasma torus associated with Io: the HISAKI observation

    NASA Astrophysics Data System (ADS)

    Tsuchiya, F.; Yoshioka, K.; Kimura, T.; Murakami, G.; Kagitani, M.; Yamazaki, A.; Kasaba, Y.; Sakanoi, T.; Yoshikawa, I.; Nozawa, H.

    2014-12-01

    Io-correlated brightness change in Io plasma torus (IPT) has been discovered by Voyager and show an evidence of local electron heating around Io. However, the amount of observation data is still limited to investigate its detail properties. In addition, the clear Io-correlated change has not been detected by EUVE and Cassini observations. Cause of the Io-correlated effect is still open issue. The HISAKI satellite was launched on Sep. 14, 2013 and started observation of IPT and Jovian aurora for more than two months since the end of Dec. 2013. EUV spectrograph onboard the HISAKI satellite covers wavelength range from 55 to 145 nm, a wide slit which had a field of view of 400 x 140 arc-second was chosen to measure radial distribution and time variation of IPT. Observation of IPT with HISAKI showed clear Io-correlated brightness change since the Voyager observation. The amplitude of the periodic variation associated with Io's orbital period was found. It also showed long-term variation during the HISAKI's observation period. Through the observation period, the amplitude was larger in the short wavelength than in long wavelength. The wavelength dependence suggests significant electron heating and/or hot electron production. The Io phase dependence shows that bright region is located just downstream of Io. These are evidence of local electron heating around/downstream of Io and consistent with the Voyager result. The brightness also depends on system-III longitude and has local maximum around 120 and 300 degrees. Based on an empirical model of IPT, electron density at Io also shows maxima around the same longitudes. This suggests that the electron heating process is related with plasma density at Io. Candidate mechanisms which are responsible for the electron heating will be discussed.

  18. Harvesting Nanocatalytic Heat Localized in Nanoalloy Catalyst as a Heat Source in a Nanocomposite Thin Film Thermoelectric Device.

    PubMed

    Zhao, Wei; Shan, Shiyao; Luo, Jin; Mott, Derrick M; Maenosono, Shinya; Zhong, Chuan-Jian

    2015-10-20

    This report describes findings of an investigation of harvesting nanocatalytic heat localized in a nanoalloy catalyst layer as a heat source in a nanocomposite thin film thermoelectric device for thermoelectric energy conversion. This device couples a heterostructured copper-zinc sulfide nanocomposite for thermoelectrics and low-temperature combustion of methanol fuels over a platinum-cobalt nanoalloy catalyst for producing heat localized in the nanocatalyst layer. The possibility of tuning nanocatalytic heat in the nanocatalyst and thin film thermoelectric properties by compositions points to a promising pathway in thermoelectric energy conversion. PMID:26444621

  19. Heat-Pipe-Associated Localized Thermoelectric Power Generation System

    NASA Astrophysics Data System (ADS)

    Kim, Pan-Jo; Rhi, Seok-Ho; Lee, Kye-Bock; Hwang, Hyun-Chang; Lee, Ji-Su; Jang, Ju-Chan; Lee, Wook-Hyun; Lee, Ki-Woo

    2014-06-01

    The present study focused on how to improve the maximum power output of a thermoelectric generator (TEG) system and move heat to any suitable space using a TEG associated with a loop thermosyphon (loop-type heat pipe). An experimental study was carried out to investigate the power output, the temperature difference of the thermoelectric module (TEM), and the heat transfer performance associated with the characteristic of the researched heat pipe. Currently, internal combustion engines lose more than 35% of their fuel energy as recyclable heat in the exhaust gas, but it is not easy to recycle waste heat using TEGs because of the limited space in vehicles. There are various advantages to use of TEGs over other power sources, such as the absence of moving parts, a long lifetime, and a compact system configuration. The present study presents a novel TEG concept to transfer heat from the heat source to the sink. This technology can transfer waste heat to any location. This simple and novel design for a TEG can be applied to future hybrid cars. The present TEG system with a heat pipe can transfer heat and generate power of around 1.8 V with T TEM = 58°C. The heat transfer performance of a loop-type heat pipe with various working fluids was investigated, with water at high heat flux (90 W) and 0.05% TiO2 nanofluid at low heat flux (30 W to 70 W) showing the best performance in terms of power generation. The heat pipe can transfer the heat to any location where the TEM is installed.

  20. Local Mass and Heat Transfer on a Turbine Blade Tip

    DOE PAGESBeta

    Jin, P.; Goldstein, R. J.

    2003-01-01

    Locmore » al mass and heat transfer measurements on a simulated high-pressure turbine blade-tip surface are conducted in a linear cascade with a nonmoving tip endwall, using a naphthalene sublimation technique. The effects of tip clearance (0.86–6.90% of chord) are investigated at various exit Reynolds numbers (4–7 × 10 5 ) and turbulence intensities (0.2 and 12.0%). The mass transfer on the tip surface is significant along its pressure edge at the smallest tip clearance. At the two largest tip clearances, the separation bubble on the tip surface can cover the whole width of the tip on the second half of the tip surface. The average mass-transfer rate is highest at a tip clearance of 1.72% of chord. The average mass-transfer rate on the tip surface is four and six times as high as on the suction and the pressure surface, respectively. A high mainstream turbulence level of 12.0% reduces average mass-transfer rates on the tip surface, while the higher mainstream Reynolds number generates higher local and average mass-transfer rates on the tip surface.« less

  1. Comparison of local and regional heat transport processes into the subsurface urban heat island of Karlsruhe, Germany

    NASA Astrophysics Data System (ADS)

    Benz, Susanne; Bayer, Peter; Menberg, Kathrin; Blum, Philipp

    2014-05-01

    Temperatures in shallow urban ground are typically elevated. They manifest as subsurface urban heat islands, which are observed worldwide in different metropolitan areas and which have a site-specific areal extent and intensity. As of right now the governing heat transport processes accumulating heat in the subsurface of cities are insufficiently understood. Based on a spatial assessment of groundwater temperatures, six individual heat flux processes could be identified: (1) heat flux from elevated ground surface temperatures (GST), (2) heat flux from basements of buildings, (3) reinjection of thermal waste water, (4) sewage drains, (5) sewage leakage, and (6) district heating. In this study, the contributions of these processes are quantified on local and regional scales for the city of Karlsruhe in Germany. For the regional scale, the Regionalized Monte Carlo (RMC) method is used. This method applies a single Monte Carlo (MC) simulation for the entire study area. At relatively low data demand, the RMC method provides basic insights into the heat contribution for the entire city. For the local scale, the Local Monte Carlo (LMC) method was developed and applied. This method analyzes all dominant heat fluxes spatially dependent by performing an MC simulation for each arbitrary sized pixel of the study area (here 10 x 10 m). This more intricate approach allows for a spatial representation of all heat flux processes, which is necessary for the local planning of geothermal energy use. In order to evaluate the heat transport processes on a regional scale, we compared the mean annual thermal energies that result from the individual heat flux processes. Both methods identify the heat flux from elevated GST and the heat flux from buildings as the dominant regional processes. However, reinjection of thermal wastewater is by far the most dominant local heat flux processes with an average heat flux of 16 ± 2 W/m2 in the affected areas. Although being dominant on the regional scale, fluxes from elevated GST and buildings only contribute with minor heat fluxes of 0.1 ± 0.3 W/m2 and 0.7 ± 0.8 W/m2, respectively, which clearly shows that such differences in heat fluxes should be carefully considered for the site specific and local planning of geothermal installations.

  2. Local Measurement of Fuel Energy Deposition and Heat Transfer Environment During Fuel Lifetime Using Controlled Calorimetry

    SciTech Connect

    Don W. Miller; Andrew Kauffmann; Eric Kreidler; Dongxu Li; Hanying Liu; Daniel Mills; Thomas D. Radcliff; Joseph Talnagi

    2001-12-31

    A comprehensive description of the accomplishments of the DOE grant titled, ''Local Measurement of Fuel Energy Deposition and Heat Transfer Environment During Fuel Lifetime using Controlled Calorimetry''.

  3. Terrestrial heat flow and radiogenic heat production in Finland, the central Baltic Shield

    NASA Astrophysics Data System (ADS)

    Kukkonen, I. T.

    1989-08-01

    Heat flow density and radiogenic heat production of the bedrock were studied in Finland in part of the central Baltic (Fennoscandian) Shield. Heat flow data were collected from 35 holes 270-1080 m deep. The heat production values at the sites were determined from the drill core samples by gamma ray spectrometry. The areal variation in heat production was studied with the aid of K, U and Th analyses of 1054 glacial till samples collected for the "Geochemical Atlas of Finland". A heat production map constructed from this data set revealed a strong areal variation that can be attributed to the known lithological, geochemical and tectonic features of the bedrock. In general, heat production seems to increase with decreasing geological age. The presented data strongly suggest that the southern and western parts of Finland are geothermally anomalous (apparent heat flow density 38-68 mW/m 2, surface heat production > 2.0 μW/m 3) in contrast to the other parts of the country (< 42 mW/ m2, < 2.0 μW/ m3). The heat production-heat flow density plots were constructed from apparent and palaeoclimatically corrected heat flow densities; the heat production values were determined from both drill core samples and till samples. The plot constructed from the till data and apparent heat flow densities, which yielded a scale depth of 10.8 ± 2.6 km and a reduced heat flow density of 15.8 ± 4.9 mW/ m2, was considered the most reliable. The results are discussed in terms of crustal fracturing and deep groundwater flow. If the crystalline bedrock is approached as a medium consisting of blocks internally conductive but bounded by fracture zones in which heat is transported by groundwater flow, an alternative hypothesis can be constructed for interpreting the linear heat production-heat flow density plots. According to this hypothesis, the scale depth and reduced heat flow densities refer only to the geothermal properties of the uppermost bedrock block. In the present study, this concept is supported by results from deep electromagnetic and seismic soundings.

  4. Martian surface heat production and crustal heat flow from Mars Odyssey Gamma-Ray spectrometry

    NASA Astrophysics Data System (ADS)

    Hahn, B. C.; McLennan, S. M.; Klein, E. C.

    2011-07-01

    Martian thermal state and evolution depend principally on the radiogenic heat-producing element (HPE) distributions in the planet's crust and mantle. The Gamma-Ray Spectrometer (GRS) on the 2001 Mars Odyssey spacecraft has mapped the surface abundances of HPEs across Mars. From these data, we produce the first models of global and regional surface heat production and crustal heat flow. As previous studies have suggested that the crust is a repository for approximately 50% of the radiogenic elements on Mars, these models provide important, directly measurable constraints on Martian heat generation. Our calculations show considerable geographic and temporal variations in crustal heat flow, and demonstrate the existence of anomalous heat flow provinces. We calculate a present day average surface heat production of 4.9 0.3 10-11 W kg-1. We also calculate the average crustal component of heat flow of 6.4 0.4 mW m-2. The crustal component of radiogenically produced heat flow ranges from <1 mW m-2 in the Hellas Basin and Utopia Planitia regions to 13 mW m-2 in the Sirenum Fossae region. These heat production and crustal heat flow values from geochemical measurements support previous heat flow estimates produced by different methodologies.

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

    PubMed Central

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

    2012-01-01

    Focusing heat delivery while minimizing collateral damage to normal tissues is essential for successful nanoparticle-mediated laser-induced thermal cancer therapy. We present thermal maps obtained via magnetic resonance imaging (MRI) characterizing laser heating of a phantom tissue containing a multiwalled carbon nanotube inclusion. The data demonstrate that heating continuously over tens of seconds leads to poor localization (~ 0.5 cm) of the elevated temperature region. By contrast, for the same energy input, heat localization can be reduced to the millimeter rather than centimeter range by increasing the laser power and shortening the pulse duration. The experimental data can be well understood within a simple diffusive heat conduction model. Analysis of the model indicates that to achieve 1 mm or better resolution, heating pulses of ~ 2s or less need to be used with appropriately higher heating power. Modeling these data using a diffusive heat conduction analysis predicts parameters for optimal targeted delivery of heat for ablative therapy. PMID:22948207

  6. The Effect of Local Heating by Laser Irradiation for Aluminum, Deep Drawing Steel and Copper Sheets in Incremental Sheet Forming

    NASA Astrophysics Data System (ADS)

    Lehtinen, Pekka; Väisänen, Tapio; Salmi, Mika

    Incremental sheet forming is a technique where a metal sheet is formed into a product usually by a CNC-controlled (Computer Numerical Control) round tipped tool. The part is formed as the tool indents into the sheet and follows a contour of the desired product. In single point incremental forming (SPIF) there is no need for tailored tools and dies, since the process requires only a CNC machine, a clamping rig and a simple tool. The effect of applying local heating by laser irradiation from the bottom side of the metal sheet is investigated with a SPIF approach. Using a laser light source for local heating should increase the material ductility and decrease material strength, and thus, increase the formability. The research was performed using 0.50-0.75 mm thick, deep drawing steel, aluminum and copper sheets. The forming was done with a round tipped tool, whose tip diameter was 4 mm. In order to achieve selective heating, a 1 kW fiber laser was attached to a 3-axis stepper motor driven CNC milling machine. The results show that the applied heating increased the maximum achievable wall angle of aluminum and copper products. However, for the steel sheets the local heating reduced the maximum achievable wall angle and increased the surface roughness.

  7. Heat production by single fibres of frog muscle.

    PubMed

    Curtin, N A; Howarth, J V; Woledge, R C

    1983-04-01

    The heat produced during contractions of preparations consisting of one or a few muscle fibres was measured for the first time. Fibres were dissected from the anterior tibialis muscles of the frog, Rana temporaria. Measurements were made with thermopiles of a design based on that described by Howarth et al. (1975). Although the fibre preparations were small, measurable signals could be recorded because the heat capacity of the thermopiles was also small. The output of the thermopile was amplified by a galvanometer circuit. In all the experiments the ends of the preparation were held in a fixed position during stimulation ("isometric'). Observations were made of heat production during twitches and tetanic contractions. The heat produced in a twitch of a single fibre depended on the stimulus strength in an all-or-nothing way. The results show that the amount of heat produced in individual twitches is fairly constant at different temperatures in the range 3-15 degrees C. In contrast, the heat produced in tetanic contractions is considerably greater at higher temperatures. The time course of heat production in a tetanus was influenced by temperature such that the early rapid phase of heat production was less obvious at the higher temperature. The quantities of heat produced by fibre preparations were in reasonable agreement with those produced by whole muscles when the comparison was made on the basis of heat produced per g wet weight of tissue. PMID:6602811

  8. Study of local heat dissipation in semiconductor devices by thermally modulated atomic force microscopy

    SciTech Connect

    Bolte, J.; Niebisch, F.; Pelzl, J.; Stelmaszyk, P.; Wieck, A. D.

    1999-03-15

    The local heat dissipation in semiconductor devices were investigated by means of a thermally modulated scanning thermoelastic microscope (STEM). The temperature induced thermal expansion and the topographic information are measured simultaneously. The spatial resolution of the constructed microscope is better than 50 nm. Heat spots of the semiconducting devices are visualised by heating with a modulated voltage.

  9. Imaging Local Heating and Thermal Diffusion of Nanomaterials with Plasmonic Thermal Microscopy.

    PubMed

    Chen, Zixuan; Shan, Xiaonan; Guan, Yan; Wang, Shaopeng; Zhu, Jun-Jie; Tao, Nongjian

    2015-12-22

    Measuring local heat generation and dissipation in nanomaterials is critical for understanding the basic properties and developing applications of nanomaterials, including photothermal therapy and joule heating of nanoelectronics. Several technologies have been developed to probe local temperature distributions in nanomaterials, but a sensitive thermal imaging technology with high temporal and spatial resolution is still lacking. Here, we describe plasmonic thermal microscopy (PTM) to image local heat generation and diffusion from nanostructures in biologically relevant aqueous solutions. We demonstrate that PTM can detect local temperature change as small as 6 mK with temporal resolution of 10 ?s and spatial resolution of submicrons (diffraction limit). With PTM, we have successfully imaged photothermal generation from single nanoparticles and graphene pieces, studied spatiotemporal distribution of temperature surrounding a heated nanoparticle, and observed heating at defect sites in graphene. We further show that the PTM images are in quantitative agreement with theoretical simulations based on heat transport theories. PMID:26435320

  10. RF heating for fusion product studies

    NASA Astrophysics Data System (ADS)

    Hellsten, T.; Johnson, T.; Sharapov, S. E.; Kiptily, V.; Eriksson, J.; Mantsinen, M.; Schneider, M.; Rimini, F.; Tsalas, M.

    2015-12-01

    Third harmonic cyclotron heating is an effective tool for accelerating deuterium (D) beams to the MeV energy range, suitable for studying ITER relevant fast particle physics in plasmas without significant tritium content. Such experiments were recently conducted in JET with an ITER like wall in D plasmas with 3He concentrations up to 30% in order to boost the fusion reactivity by D-3He reactions. The harmonic cyclotron heating produces high-energy tails in the MeV range of D ions by on-axis heating and of 3He ions by tangential off-axis heating. The discharges are characterized by long sawtooth free periods and a rich spectrum of MHD modes excited by the fast D and 3He ions. The partitions of the power, which depend on the distribution function of D, vary strongly over several slowing down times. Self-consistent modelling of the distribution function with the SELFO-light code are presented and compared with experimental data from fast particle diagnostics.

  11. District heating from electric-generating plants and municipal incinerators: local planner's assessment guide

    SciTech Connect

    Pferdehirt, W.; Kron, N. Jr.

    1980-11-01

    This guide is designed to aid local government planners in the preliminary evaluation of the feasibility of district heating using heat recovered from electric generating plants and municipal incinerators. System feasibility is indicated by: (1) the existence of an adequate supply of nearby waste heat, (2) the presence of a sufficiently dense and large thermal load, and (3) a favorable cost comparison with conventional heating methods. 34 references.

  12. Rubisco activase and wheat productivity under heat stress conditions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rubisco activase (RCA) constrains the photosynthetic potential of plants at high temperature (heat stress). We hypothesized that endogenous levels of RCA could serve as an important determinant of plant productivity under heat stress conditions. In this study, we investigated the possible relation...

  13. Plasmonic local heating beyond diffraction limit by the excitation of magnetic polariton

    NASA Astrophysics Data System (ADS)

    Alshehri, Hassan; Wang, Hao; Ma, Yanchao; Wang, Liping

    2015-08-01

    In recent years, optical local heating in the nanoscale has attracted great attention due to its unique features of small hot spot size and high energy density. Plasmonic local heating can provide solutions to several challenges in data storage and cancer treatment. Research conducted in this field to achieve plasmonic local heating has mainly utilized the excitation of localized surface plasmon (LSP) or surface plasmon resonance (SPR). However, achieving plasmonic local heating by the excitation of magnetic polariton (MP) has not been researched extensively yet. We numerically investigate the optical response of a nanostructure composed of a gold nanowire on a gold surface separated by a polymer spacer using the ANSYS High Frequency Structural Simulator (HFSS). The structure exhibits a strong absorption peak at the wavelength of 750 nm, and the underlying physical mechanism is verified by the local electromagnetic field distribution to be the magnetic resonance excitation. By incorporating the volume loss density due to the strong local optical energy confinement as the heat generation, nanoscale temperature distribution within the structure is numerically obtained with a thermal solver after assigning proper boundary conditions. The results show a maximum temperature of 158.5C confined in a local area on the order of 35 nm within the ultrathin polymer layer, which clearly demonstrates the plasmonic local heating effect beyond diffraction limit by excitation of MP.

  14. Local pressure measurements and heat transfer coefficients of flow boiling in a rectangular microchannel

    NASA Astrophysics Data System (ADS)

    Mirmanto, M.

    2016-01-01

    Experiments to investigate local pressure distribution and local heat transfer coefficients during flow boiling of water in a microchannel were performed. The hydraulic diameter of the channel was 0.635 mm. The nominal mass fluxes used were varied from 200 to 700 kg/m2 s and heat fluxes ranging from 171 to 685 kW/m2 were applied. An inlet fluid temperature of 98 °C and pressure of 125 kPa were maintained at the microchannel entrance. There were six pressure tappings inserted into the channel to measure the local pressures and six thermocouple inserted into the channel block with equally distances to measure the wall local temperatures. The local pressure measurements during flow boiling show a non linear line connecting each local pressure, especially at higher heat fluxes or pressure drops. The non linear local pressure influences the value of the estimated local heat transfer coefficient. The effects of mass flux and heat flux on local heat transfer coefficient are also discussed.

  15. NGNP Process Heat Applications: Hydrogen Production Accomplishments for FY2010

    SciTech Connect

    Charles V Park

    2011-01-01

    This report summarizes FY10 accomplishments of the Next Generation Nuclear Plant (NGNP) Engineering Process Heat Applications group in support of hydrogen production technology development. This organization is responsible for systems needed to transfer high temperature heat from a high temperature gas-cooled reactor (HTGR) reactor (being developed by the INL NGNP Project) to electric power generation and to potential industrial applications including the production of hydrogen.

  16. Effect of whole-body and local heating on cutaneous vasoconstrictor responses in humans

    NASA Technical Reports Server (NTRS)

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

    2002-01-01

    Animal studies suggest that alpha-adrenergic-mediated vasoconstriction is compromised during whole-body heating. The purpose of this study was to identify whether whole-body heating and/or local surface heating reduce cutaneous alpha-adrenergic vasoconstrictor responsiveness in human skin. Protocol I: Six subjects were exposed to neutral skin temperature (i.e., 34 degrees C), whole-body heating, and local heating of forearm skin to increase skin blood flow to the same relative magnitude as that observed during whole-body heating. Protocol II: In eight subjects forearm skin was locally heated to 34, 37, 40, and 42 degrees C. During both protocols, alpha-adrenergic vasoconstrictor responsiveness was assessed by local delivery of norepinephrine (NE) via intradermal microdialysis. Skin blood flow was continuously monitored over each microdialysis membrane via laser-Doppler flowmetry. In protocol I, whole-body and local heating caused similar increases in cutaneous vascular conductance (CVC). The EC50 (log NE dose) of the dose-response curves for both whole body (-4.2 +/- 0.1 M) and local heating (-4.7 +/- 0.4 M) were significantly greater (i.e., high dose required to cause 50% reduction in CVC) relative to neutral skin temperature (- 5.6 +/- 0.0 M; P<0.05 for both). In both local and whole-body heated conditions CVC did not return to pre-heating values even at the highest dose of NE. In protocol II, calculated EC50 for 34, 37, 40, and 42 degrees C local heating was - 5.5 +/- 0.4, -4.6 +/- 0.3, -4.5 +/- 0.3, - 4.2 +/- 0.4 M, respectively. Statistical analyses revealed that the EC50 for 37,40 and 42 degrees C were significantly greater than the EC50 for 34 degrees C. These results indicate that even during administration of high concentrations of NE, alpha-adrenergic vasoconstriction does not fully compensate for local heating and whole-body heating induced vasodilatation in young, healthy subjects. Moreover, these data suggest that elevated local temperatures, above 37 degrees C, and whole-body heating similarly attenuate cutaneous alpha-adrenergic vasoconstriction responsiveness.

  17. Heat Pipe Solar Receiver for Oxygen Production of Lunar Regolith

    NASA Astrophysics Data System (ADS)

    Hartenstine, John R.; Anderson, William G.; Walker, Kara L.; Ellis, Michael C.

    2009-03-01

    A heat pipe solar receiver operating in the 1050° C range is proposed for use in the hydrogen reduction process for the extraction of oxygen from the lunar soil. The heat pipe solar receiver is designed to accept, isothermalize and transfer solar thermal energy to reactors for oxygen production. This increases the available area for heat transfer, and increases throughput and efficiency. The heat pipe uses sodium as the working fluid, and Haynes 230 as the heat pipe envelope material. Initial design requirements have been established for the heat pipe solar receiver design based on information from the NASA In-Situ Resource Utilization (ISRU) program. Multiple heat pipe solar receiver designs were evaluated based on thermal performance, temperature uniformity, and integration with the solar concentrator and the regolith reactor(s). Two designs were selected based on these criteria: an annular heat pipe contained within the regolith reactor and an annular heat pipe with a remote location for the reactor. Additional design concepts have been developed that would use a single concentrator with a single solar receiver to supply and regulate power to multiple reactors. These designs use variable conductance or pressure controlled heat pipes for passive power distribution management between reactors. Following the design study, a demonstration heat pipe solar receiver was fabricated and tested. Test results demonstrated near uniform temperature on the outer surface of the pipe, which will ultimately be in contact with the regolith reactor.

  18. Method of heat treating a formed powder product material

    NASA Technical Reports Server (NTRS)

    Freche, J. C.; Waters, W. J.; Ashbrook, R. L. (Inventor)

    1973-01-01

    Heat treating a product material of prealloyed powders after shaping by superplastic deformation restores the ability of the material to resist deformation at high temperatures. Heat treating is accomplished by heating to a temperature between the solidus and liquidus with the application of isostatic pressure to close any voids. This pressure may be simultaneously applied while the material is at the heat treating temperature. The pressure may also be applied when the material cools to a temperature between that at which it is shaped and the solidus.

  19. Novel oriented channels products for heat exchangers

    SciTech Connect

    Tuchinskiy, L.

    1995-11-01

    The new method, which allows one to produce microhoneycombs of metal, ceramics, and composites with highly developed inner surface has been developed. That makes it possible to create the tubes with thousands of channels and design on their base new highly efficient heat-exchangers, catalyst carriers, filters, etc. Relationships between honeycomb elastic constants and the channel porosity have been obtained. Formulas to calculate the longitudinal and lateral thermal conductivity of microhoneycombs, which allow one to consider not only the number of channels but the structure of honeycombs, have been deduced.

  20. Vermont Biofuels Initiative: Local Production for Local Use to Supply a Portion of Vermont's Energy Needs

    SciTech Connect

    Sawyer, Scott; Kahler, Ellen

    2009-05-31

    The Vermont Biofuels initiative (VBI) is the Vermont Sustainable Jobs Fund's (VSJF) biomass-to-biofuels market development program. Vermont is a small state with a large petroleum dependency for transportation (18th in per capita petroleum consumption) and home heating (55% of all households use petroleum for heating). The VBI marks the first strategic effort to reduce Vermont's dependency on petroleum through the development of homegrown alternatives. As such, it supports the four key priorities of the U.S. Department of Energy's Multi-year Biomass Plan: 1.) Dramatically reduce dependence on foreign oil; 2.) Promote the use of diverse, domestic and sustainable energy resources; 3.) Reduce carbon emissions from energy production and consumption; 4.) Establish a domestic bioindustry. In 2005 VSJF was awarded with a $496,000 Congressionally directed award from U.S. Senator Patrick Leahy. This award was administered through the U.S. Department of Energy (DE-FG36- 05GO85017, hereafter referred to as DOE FY05) with $396,000 to be used by VSJF for biodiesel development and $100,000 to be used by the Vermont Department of Public Service for methane biodigester projects. The intent and strategic focus of the VBI is similar to another DOE funded organization-the Biofuels Center of North Carolina-in that it is a nonprofit driven, statewide biofuels market development effort. DOE FY05 funds were expensed from 2006 through 2008 for seven projects: 1) a feedstock production, logistics, and biomass conversion research project conducted by the University of Vermont Extension; 2) technical assistance in the form of a safety review and engineering study of State Line Biofuels existing biodiesel production facility; 3) technical assistance in the form of a safety review and engineering study of Borderview Farm's proposed biodiesel production facility; 4) technology and infrastructure purchases for capacity expansion at Green Technologies, LLC, a waste vegetable biodiesel producer; 5) technical assistance in the form of feasibility studies for AgNorth Biopower LLC's proposed multi-feedstock biodigester; 6) technology and infrastructure purchases for the construction of a "Cow Power" biodigester at Gervais Family Farm; and 7) the education and outreach activities of the Vermont Biofuels Association. DOE FY05 funded research, technical assistance, and education and outreach activities have helped to provide Vermont farmers and entrepreneurs with important feedstock production, feedstock logistics, and biomass conversion information that did not exist prior as we work to develop an instate biodiesel sector. The efficacy of producing oilseed crops in New England is now established: Oilseed crops can grow well in Vermont, and good yields are achievable given improved harvesting equipment and techniques. DOE FY05 funds used for technology and infrastructure development have expanded Vermont's pool of renewable electricity and liquid fuel generation. It is now clear that on-farm energy production provides an opportunity for Vermont farmers and entrepreneurs to reduce on-farm expenditures of feed and fuel while providing for their energy security. Meanwhile they are developing new value-added revenue sources (e.g., locally produced livestock meal), retaining more dollars in the local economy, and reducing greenhouse gas emissions.

  1. Application of varied measurement conditions in evaluation of plasters with local heating activity.

    PubMed

    Musia?, Witold; Pluta, Janusz; Szumny, Antoni

    2010-01-01

    The aim of our study was to compare the temperatures of selected heating pads in conditions similar to standard application, and in conditions of isolated pads applied on the area with impaired local circulation. The research was conducted for three kinds of preparations, accessible on the polish pharmaceutical market, encoded as pads I, II, and III, and stored due to the manufacturer guidelines. In the first phase study--in conditions mimicking the physiological situation, mean temperature value, after gaining plateau phase, was at the level of ca. 42.5 degrees C. The fast increase of temperature of I and II pads, followed after 10 and 15 minutes respectively. Also pad III presented similar increase of temperature. The data obtained in the second part of the experiment were different comparing to the thermostated model. High differences were recorded between pads I, II, and III. The I pads attained the maximum temperature after ca. 20-25 min, and the temperature was maintained on the level of 60-65 degrees C, and this is threated by immediate tissue damage after 5 sec. the application of heating pads in patients with proper local circulation, and when there is no additional isolation on the pad, seems to be safe and effective, however the complete evaluation of the product must be confirmed in "in vivo" conditions, e.g., with human volunteers. PMID:21110501

  2. Local nucleation propagation on heat transfer uniformity during subcooled convective boiling

    NASA Astrophysics Data System (ADS)

    Kim, Beom Seok; Yang, Gang Mo; Shin, Sangwoo; Choi, Geehong; Cho, Hyung Hee

    2015-01-01

    Convective boiling heat transfer is an efficient cooling mechanism to dissipate amount of thermal energy by accompanying the phase transition of the working fluids. Particularly, the amount of heat dissipation capacity can be readily extensible by increasing the degree of subcooling due to initial demands requiring for coolant saturation. Under severely subcooled condition of 60°, we investigate boiling heat transfer phenomena regarding spatial heat transfer uniformity and stability on a planar surface. Severe subcooling can induce locally concentrated thermal loads due to poor spatial uniformity of the heat transfer. For reliable cooling, a high degree of spatial uniformity of the heat transfer should be guaranteed with minimized spatial deviation of heat transfer characteristics. Under pre-requisite safeguards below CHF, we experimentally elucidate the principal factors affecting the spatial uniformity of the heat transfer for a flow/thermal boundary layer considering heat transfer domains from a single-phase regime to a fully-developed boiling regime. Based on the local heat transfer evaluation, we demonstrate that full nucleation boiling over the entire heat transfer surface under subcooling conditions is favorable in terms of the uniformity of heat dissipation through the phase-change of the working fluid.

  3. Localized induction heating solder bonding for wafer level MEMS packaging

    NASA Astrophysics Data System (ADS)

    Yang, Hsueh-An; Wu, Mingching; Fang, Weileun

    2005-02-01

    This paper reports a new solder bonding method for the wafer level packaging of MEMS devices. Electroplated magnetic film was heated using induction heating causing the solder to reflow. The experiment results show that it took less than 1 min to complete the bonding process. In addition, the MEMS devices experienced a temperature of only 110 C during bonding, thus thin film materials would not be damaged. Moreover, the bond strength between silicon and silicon wafer was higher than 18 MPa. The step height of the feed-through wire (acting as the electrical feed-through of the bonded region) is sealed by the electroplated film. Thus, the flatness and roughness of the electroplated surface are recovered by the solder reflow, and the package for preventing water leakage can be achieved. The integration of the surface micromachined devices with the proposed packaging techniques was demonstrated.

  4. The Therapeutic Use of Local Heat and Cold

    PubMed Central

    Tepperman, Perry S.; Devlin, Michael

    1986-01-01

    Thermotherapy and cryotherapy are often valuable in the treatment of pain, inflammation and muscle spasm. Safe use of available modalities depends on specific knowledge of their contraindications. The choice of method requires an understanding of the physiological effects of heat and cold. The choice of any individual thermal modality depends on several factors including size of the area to be treated, ease of application, affordability, duration of application and depth of penetration. PMID:21267207

  5. Prediction of local and integrated heat transfer in nozzles using an integral turbulent boundary layer method

    NASA Technical Reports Server (NTRS)

    Boldman, D. R.; Schmidt, J. F.; Ehlers, R. C.

    1972-01-01

    An empirical modification of an existing integral energy turbulent boundary layer method is proposed in order to improve the estimates of local heat transfer in converging-diverging nozzles and consequently, provide better assessments of the total or integrated heat transfer. The method involves the use of a modified momentum-heat analogy which includes an acceleration term comprising the nozzle geometry and free stream velocity. The original and modified theories are applied to heat transfer data from previous studies which used heated air in 30 deg - 15 deg, 45 deg - 15 deg, and 60 deg - 15 deg water-cooled nozzles.

  6. Feasibility of local condom production examined.

    PubMed

    1999-01-01

    Despite Africa being the world region worst affected by the HIV/AIDS pandemic, there is only 1 condom manufacturer on the continent, in Johannesburg. Hundreds of millions of condoms are donated and imported annually. For example, 500 million units were donated in 1996, of which 212 million came from the US Agency for International Development. A recently released study commissioned by the European Union's HIV/AIDS Program for Developing Countries determined that it would be technically viable to manufacture condoms in not only South Africa, but also in Mauritius, Cote d'Ivoire, and Kenya. All that is required is a factory, work force, water, and electricity, with the raw materials to be imported from Malaysia or Thailand regardless of where the factory is located. The financial returns of such an operation would depend upon the cost of labor, the type of factory and its output, and market demand. Benefits would include employment creation, potential exports, and foreign exchange savings. A typical condom plant, operating 24 hours a day with 2 production lines, can produce 160 million condom units per year. However, should such a factory be built and put into operation, managers must ensure that any condoms produced are of high quality. PMID:12295121

  7. Evidence for localized cell heating induced by infrared optical tweezers.

    PubMed Central

    Liu, Y; Cheng, D K; Sonek, G J; Berns, M W; Chapman, C F; Tromberg, B J

    1995-01-01

    The confinement of liposomes and Chinese hamster ovary (CHO) cells by infrared (IR) optical tweezers is shown to result in sample heating and temperature increases by several degrees centigrade, as measured by a noninvasive, spatially resolved fluorescence detection technique. For micron-sized spherical liposome vesicles having bilayer membranes composed of the phospholipid 1,2-diacyl-pentadecanoyl-glycero-phosphocholine (15-OPC), a temperature rise of approximately 1.45 +/- 0.15 degrees C/100 mW is observed when the vesicles are held stationary with a 1.064 microns optical tweezers having a power density of approximately 10(7) W/cm2 and a focused spot size of approximately 0.8 micron. The increase in sample temperature is found to scale linearly with applied optical power in the 40 to 250 mW range. Under the same trapping conditions, CHO cells exhibit an average temperature rise of nearly 1.15 +/- 0.25 degrees C/100 mW. The extent of cell heating induced by infrared tweezers confinement can be described by a heat conduction model that accounts for the absorption of infrared (IR) laser radiation in the aqueous cell core and membrane regions, respectively. The observed results are relevant to the assessment of the noninvasive nature of infrared trapping beams in micromanipulation applications and cell physiological studies. Images FIGURE 1 FIGURE 3 PMID:7612858

  8. Heat stress causes substantial labour productivity loss in Australia

    NASA Astrophysics Data System (ADS)

    Zander, Kerstin K.; Botzen, Wouter J. W.; Oppermann, Elspeth; Kjellstrom, Tord; Garnett, Stephen T.

    2015-07-01

    Heat stress at the workplace is an occupational health hazard that reduces labour productivity. Assessment of productivity loss resulting from climate change has so far been based on physiological models of heat exposure. These models suggest productivity may decrease by 11-27% by 2080 in hot regions such as Asia and the Caribbean, and globally by up to 20% in hot months by 2050. Using an approach derived from health economics, we describe self-reported estimates of work absenteeism and reductions in work performance caused by heat in Australia during 2013/2014. We found that the annual costs were US$655 per person across a representative sample of 1,726 employed Australians. This represents an annual economic burden of around US$6.2 billion (95% CI: 5.2-7.3 billion) for the Australian workforce. This amounts to 0.33 to 0.47% of Australia’s GDP. Although this was a period when many Australians experienced what is at present considered exceptional heat, our results suggest that adaptation measures to reduce heat effects should be adopted widely if severe economic impacts from labour productivity loss are to be avoided if heat waves become as frequent as predicted.

  9. Photoinduced local heating in silica photonic crystals for fast and reversible switching.

    PubMed

    Gallego-Gmez, Francisco; Blanco, Alvaro; Lpez, Cefe

    2012-12-01

    Fast and reversible photonic-bandgap tunability is achieved in silica artificial opals by local heating. The effect is fully reversible as heat rapidly dissipates through the non-irradiated structure without active cooling and water is readsorbed. The performance is strongly enhanced by decreasing the photoirradiated opal volume, allowing bandgap shifts of 12 nm and response times of 20 ms. PMID:22976241

  10. Remotely actuated localized pressure and heat apparatus and method of use

    NASA Technical Reports Server (NTRS)

    Merret, John B. (Inventor); Taylor, DeVor R. (Inventor); Wheeler, Mark M. (Inventor); Gale, Dan R. (Inventor)

    2004-01-01

    Apparatus and method for the use of a remotely actuated localized pressure and heat apparatus for the consolidation and curing of fiber elements in, structures. The apparatus includes members for clamping the desired portion of the fiber elements to be joined, pressure members and/or heat members. The method is directed to the application and use of the apparatus.

  11. Interfacing primary heat sources and cycles for thermochemical hydrogen production

    SciTech Connect

    Bowman, M.G.

    1980-01-01

    Advantages cited for hydrogen production from water by coupling thermochemical cycles with primary heat include the possibility of high efficiencies. These can be realized only if the cycle approximates the criteria required to match the characteristics of the heat source. Different types of cycles may be necessary for fission reactors, for fusion reactors or for solar furnaces. Very high temperature processes based on decomposition of gaseous H/sub 2/O or CO/sub 2/ appear impractical even for projected solar technology. Cycles based on CdO decomposition are potentially quite efficient and require isothermal heat at temperatures that may be available from solar furnaces of fusion reactors. Sulfuric acid and solid sulfate cycles are potentially useful at temperatures available from each heat source. Solid sulfate cycles offer advantages for isothermal heat sources. All cycles under development include concentration and drying steps. Novel methods for improving such operations would be beneficial.

  12. Monodisperse Magnetofluorescent Nanoplatforms for Local Heating and Temperature Sensing

    PubMed Central

    Zhang, H.; Huang, H.; He, S.

    2014-01-01

    Monodisperse multifunctional MnFe2O4/dye/silica core/shell nanoparticles have been designed and developed. The magnetic cores act as nano-heaters in biological systems under RF field excitation and the encapsulated dyes work as local temperature probes. The silica shells enable the water-solubility and biocompatibility of the NPs and protect the encapsulated fluorophores from photobleaching. PMID:25308371

  13. Observation of localized heating phenomena during microwave heating of mixed powders using in situ x-ray diffraction technique

    SciTech Connect

    Sabelström, N. Hayashi, M.; Watanabe, T.; Nagata, K.

    2014-10-28

    In materials processing research using microwave heating, there have been several observations of various phenomena occurring known as microwave effects. One significant example of such a phenomenon is increased reaction kinetics. It is believed that there is a possibility that this might be caused by localized heating, were some reactants would attain a higher than apparent temperature. To examine whether such thermal gradients are indeed possible, mixed powders of two microwave non-absorbers, alumina and magnesia, were mixed with graphite, a known absorber, and heated in a microwave furnace. During microwave irradiation, the local temperatures of the respective sample constituents were measured using an in situ x-ray diffraction technique. In the case of the alumina and graphite sample, a temperature difference of around 100 °C could be observed.

  14. Heat production during contraction in skeletal muscle of hypothyroid mice

    SciTech Connect

    Leijendekker, W.J.; van Hardeveld, C.; Elzinga, G. )

    1987-08-01

    The effect of hypothyroidism on tension-independent and -dependent heat produced during a twitch and a tetanic contraction of extensor digitorum longus (EDL) and soleus muscle of mice was examined. The amount of heat produced during a twitch and the rate of heat development during a tetanus of EDL and soleus were measured at and above optimal length. The effect of hypothyroidism on force production was <30%. Straight lines were used to fit the relation between heat production and force. Hypothyroidism significantly decreases tension-independent heat during contraction of EDL and soleus muscle. Because the tension-independent heat is considered to be related to the Ca{sup 2+} cycling, these findings suggest that ATP splitting due to the Ca{sup 2+} cycling is reduced in hypothyroid mice. This conclusion was strengthened by the observation that the oxalate-supported {sup 45}Ca{sup 2+}-uptake activity and {sup 45}Ca{sup 2+}-loading capacity of muscle homogenates from hypothyroid mice were reduced, respectively, to 51 and to 65% in soleus and to 63 and 73% in EDL muscle as compared with euthyroid mice. The tension-dependent rate of heat development during a tetanus was also decreased in soleus muscle of hypothyroid mice. This suggests a lower rate of ATP hydrolysis related to cross-bridge cycling in this muscle due to the hypothyroid state.

  15. Ohmic heated sheet for the Ca ion beam production

    SciTech Connect

    Efremov, A.; Bogomolov, S.; Kazarinov, N.; Kochagov, O.; Loginov, V.

    2008-02-15

    The production of intense accelerated {sup 48}Ca ion beams is the key problem in the experiments on the synthesis of new superheavy nuclei. For this purpose in the FLNR (JINR), an electron cyclotron resonance ion source is used at the U-400 cyclotron. The combination of a micro oven with a hot tantalum sheet inside the discharge chamber allowed the production of the intense {sup 48}Ca{sup 5+} ion beam at the {sup 48}Ca consumption of about 0.5 mg/h. In this case, the tantalum sheet is heated by microwaves and plasma electrons. The microwave power of up to 500 W is required to heat the sheet to the temperature of about 500 deg. C. To decrease the required microwave power, a new sheet with a direct Ohmic heating was designed. The present paper describes the method, technique, and preliminary experimental results on the production of the Ca ion beam.

  16. Reversible control of current across lipid membranes by local heating

    PubMed Central

    Urban, Patrick; Kirchner, Silke R.; Mühlbauer, Christian; Lohmüller, Theobald; Feldmann, Jochen

    2016-01-01

    Lipid membranes are almost impermeable for charged molecules and ions that can pass the membrane barrier only with the help of specialized transport proteins. Here, we report how temperature manipulation at the nanoscale can be employed to reversibly control the electrical resistance and the amount of current that flows through a bilayer membrane with pA resolution. For this experiment, heating is achieved by irradiating gold nanoparticles that are attached to the bilayer membrane with laser light at their plasmon resonance frequency. We found that controlling the temperature on the nanoscale renders it possible to reproducibly regulate the current across a phospholipid membrane and the membrane of living cells in absence of any ion channels. PMID:26940847

  17. Reversible control of current across lipid membranes by local heating.

    PubMed

    Urban, Patrick; Kirchner, Silke R; Mühlbauer, Christian; Lohmüller, Theobald; Feldmann, Jochen

    2016-01-01

    Lipid membranes are almost impermeable for charged molecules and ions that can pass the membrane barrier only with the help of specialized transport proteins. Here, we report how temperature manipulation at the nanoscale can be employed to reversibly control the electrical resistance and the amount of current that flows through a bilayer membrane with pA resolution. For this experiment, heating is achieved by irradiating gold nanoparticles that are attached to the bilayer membrane with laser light at their plasmon resonance frequency. We found that controlling the temperature on the nanoscale renders it possible to reproducibly regulate the current across a phospholipid membrane and the membrane of living cells in absence of any ion channels. PMID:26940847

  18. Local Heat Transfer and CHF for Subcooled Flow Boiling - Annual Report 1994

    SciTech Connect

    Dr. Ronald D. Boyd

    2000-07-01

    The physical phenomenon of forced convective boiling is probably one of the most interesting and complex transport phenomena. It has been under study for more than two centuries. Simply stated, forced convective subcooled boiling involves a locally boiling fluid: (1) whose mean temperature is below its saturation temperature, and (2) that flows over a surface exposed uniformly or non-uniformly to a high heat flux (HHF). The objective of this work is to assess and/or improve the present ability to predict local axial heat transfer distributions in the subcooled flow boiling regime for the case of uniformly heated coolant channels. This requires an accurate and complete representation of the boiling curve up to the CHF. The present. results will be useful for both heat transfer research and industrial design applications. Future refinements may result in the application of the results to non-uniformly heated channels or other geometries, and other fluids. Several existing heat transfer models for uniformly heated channels were examined for: (1) accurate representation of the boiling curve, and (2) characterizing the local heat transfer coefficient under high heat flux (HHF) conditions. Comparisons with HHF data showed that major correlation modifications were needed in the subcooled partial nucleate boiling (SPNB) region. Since the slope of boiling curve in this region is important to assure continuity of the HHF trends into the fully developed boiling region and up to the critical heat flux, accurate characterization in the SPNB region is essential. Approximations for the asymptotic limits for the SPNB region have been obtained and have been used to develop an improved composite correlation. The developed correlation has been compared with 363 water data points. For the local heat transfer coefficient and wall temperature, the over-all percent standard deviations with respect to the data were 19% and 3%, respectively, for the high velocity water data.

  19. Study of the change of electron temperature inside magnetic island caused by localized radio frequency heating

    SciTech Connect

    Yang, J.; Zhu, S.; Yu, Q.; Zhuang, G.

    2010-05-15

    The change in the electron temperature inside magnetic island caused by localized radio frequency (rf) heating is studied numerically by solving the two-dimensional energy transport equation, to investigate the dependence of the temperature change on the location and width of the rf power deposition along the minor radius and the helical angle, the island width, and the ratio between the parallel and the perpendicular heat conductivity. Based on obtained numerical results, suggestions for optimizing the island stabilization by localized rf heating are made.

  20. Measurement of local connective heat transfer coefficients of four ice accretion shapes

    NASA Technical Reports Server (NTRS)

    Smith, M. E.; Armilli, R. V.; Keshock, E. G.

    1984-01-01

    In the analytical study of ice accretions that form on aerodynamic surfaces (airfoils, engine inlets, etc.) it is often necessary to be able to calculate convective heat transfer rates. In order to do this, local convective heat transfer coefficients for the ice accretion shapes must be known. In the past, coefficients obtained for circular cylinders were used as an approximation to the actual coefficients since no better information existed. The purpose of this experimental study was to provide local convective heat transfer coefficients for four shapes that represent ice accretions. The shapes were tested with smooth and rough surfaces. The experimental method chosen was the thin-skin heat rate technique. Using this method local Nusselt numbers were determined for the ice shapes. In general it was found that the convective heat transfer was higher in regions where the model's surfaces were convex and lower in regions where the model's surfaces were concave. The effect of roughness was to increase the heat transfer in the high heat transfer regions by approximately 100% while little change was apparent in the low heat transfer regions.

  1. Intracellular Localization of Heat Shock Proteins in Maize 1

    PubMed Central

    Cooper, Pam; Ho, Tuan-Hua David

    1987-01-01

    The intracellular distribution of the maize root heat shock proteins (hsp) was studied as a step toward understanding their physiological function. Linear sucrose density centrifugation was employed to separate organelles so the relative quantities of hsp in different subcellular compartments could be analyzed in a single preparation. Gradient fractions were assayed for the presence of hsp by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and for marker enzyme activities. Analyses of 15 to 60% gradients showed five hsp to be organelle associated. Hsp 25 and 72 were in fractions containing closely equilibrating Golgi and endoplasmic reticulum marker activities, while hsp 18, 29, and 72 were in fractions containing overlapping plasma membrane, mitochondria, and glyoxysomal marker activities. Hsp larger than 72 kilodaltons were not present in gradient fractions. A second fractionation scheme achieved better separation of the two sets of closely equilibrating organelles. When a 13,000g centrifugation step to remove mitochondria was employed prior to gradient centrifugation, hsp 29 was absent from the gradient fractions. If the buoyant density of the endoplasmic reticulum was shifted by either maintaining the ribosomes on the membrane or removing them, a corresponding shift in the equilibrium positions of hsp 25 and 72 occurred. Hsp 18 and 70 remained in plasma membrane-containing fractions irrespective of these treatments. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 PMID:16665584

  2. Antioxidants in heat-processed koji and the production mechanisms.

    PubMed

    Okutsu, Kayu; Yoshizaki, Yumiko; Ikeda, Natsumi; Kusano, Tatsuro; Hashimoto, Fumio; Takamine, Kazunori

    2015-11-15

    We previously developed antioxidative heat-processed (HP)-koji via two-step heating (55 C/2days ? 75 C/3 days) of white-koji. In this study, we isolated antioxidants in HP-koji and investigated their formation mechanisms. The antioxidants were identified to be 5-hydroxymethyl furfural (HMF) and 5-(?-D-glucopyranosyloxymethyl)-2-furfural (GMF) based on nuclear magnetic resonance spectral analysis. HMF and GMF were not present in intact koji, but were formed by heating at 75 C. As production of these antioxidants was more effective by two-step heating than by constant heating at 55 C or 75 C, we presumed that the antioxidant precursors are derived enzymatically at 55C and that the antioxidants are formed subsequently by thermal reaction at 75 C. The heating assay of saccharide solutions revealed glucose and isomaltose as HMF and GMF precursors, respectively, and thus the novel finding of GMF formation from isomaltose. Finally, HMF and GMF were effectively formed by two-step heating from glucose and isomaltose present in koji. PMID:25977038

  3. Maintaining health, comfort and productivity in heat waves

    PubMed Central

    Parsons, Ken

    2009-01-01

    Background The aim of this paper is to summarise what is known about human response to heat and to use this knowledge to provide guidance on how to maintain the health, comfort and performance of people in heat waves. Design The use of power and especially water are critical in providing cooling. A practical method of cooling people in a water bath is described. A warm bath slowly cooled will provide effective cooling but not thermal trauma. Result It is concluded that for sedentary and light activities, it is not necessary to cool offices or homes below 25C for thermal comfort. Conclusion To compare the costs due to loss of productivity caused by a heat wave, with the cost of taking action, more research is needed into the relationship between levels of heat stress and how much distraction and time off task it causes. PMID:20052377

  4. Magnonics: Selective heat production in nanocomposites with different magnetic nanoparticles

    NASA Astrophysics Data System (ADS)

    Gu, Yu; Kornev, Konstantin G.

    2016-03-01

    We theoretically study Ferromagnetic Resonance (FMR) in nanocomposites focusing on the analysis of heat production. It is demonstrated that at the FMR frequency, the temperature of nanoparticles can be raised at the rate of a few degrees per second at the electromagnetic (EM) irradiation power equivalent to the sunlight power. Thus, using FMR, one can initiate either surface or bulk reaction in the vicinity of a particular magnetic inclusion by purposely delivering heat to the nanoscale at a sufficiently fast rate. We examined the FMR features in (a) the film with a mixture of nanoparticles made of different materials; (b) the laminated films where each layer is filled with a particular type of magnetic nanoparticles. It is shown that different nanoparticles can be selectively heated at the different bands of EM spectrum. This effect opens up new exciting opportunities to control the microwave assisted chemical reactions depending on the heating rate.

  5. Large spectral tuning of liquid microdroplets by local heating with a focused infrared laser

    NASA Astrophysics Data System (ADS)

    Kiraz, Alper; Karadağ, Yasin; Yorulmaz, Saime Ç.; Muradoğlu, Metin

    2008-08-01

    Large deformations can easily be introduced in liquid microdroplets by applying relatively small external forces or controlling the evaporation/condensation kinetics. This makes liquid microdroplets attractive to serve as the building blocks of largely tunable optical switches or filters that are essential in optical communication systems based on wavelength division multiplexing. Solid optical microcavities have not found large use in these applications, mainly due to their rigid nature. The fact that liquid microdroplets are low-cost and disposable can also prove to be important in mass production of these photonic devices. Here, we show that local heating with an infrared laser can be used to largely tune the whispering gallery modes (WGMs) of water/glycerol or salty water microdroplets standing on a superhydrophobic surface. In the scheme presented, a liquid microdroplet kept in a humidity chamber is stabilized on a superhydrophobic surface, and an infrared laser beam is focused near the center of the microdroplet. As a result of the local heating, the temperature of the liquid microdroplet increases, and the water content in the liquid microdroplet evaporates until a new equilibrium is reached. At the new equilibrium state, the non-volatile component (i.e. glycerol or salt) attains a higher concentration in the liquid microdroplet. We report tunability over large spectral ranges up to 30 nm at around 590 nm. For salty water microdroplets the reported spectral tuning mechanism is almost fully reversible, while for the case of glycerol/water microdroplets the spectral tuning mechanism can be made highly reversible when the chamber is saturated with glycerol vapor and the relative water humidity approaches unity.

  6. Local electron heating in the Io plasma torus associated with Io from HISAKI satellite observation

    NASA Astrophysics Data System (ADS)

    Tsuchiya, Fuminori; Kagitani, Masato; Yoshioka, Kazuo; Kimura, Tomoki; Murakami, Go; Yamazaki, Atsushi; Nozawa, Hiromasa; Kasaba, Yasumasa; Sakanoi, Takeshi; Uemizu, Kazunori; Yoshikawa, Ichiro

    2015-12-01

    Io-correlated brightness change in the Io plasma torus (IPT) was discovered by the Voyager spacecraft, showing evidence of local electron heating around Io. However, its detailed properties and the cause of electron heating are still open issues. The extreme ultraviolet spectrograph on board the HISAKI satellite continuously observed the IPT from the end of December 2013 to the middle of January 2014. The variation in the IPT brightness showed that clear periodicity associated with Io's orbital period (42 h) and that the bright region was located downstream of Io. The amplitude of the periodic variation was larger at short wavelengths than at long wavelengths. From spectral analyses, we found that Io-correlated brightening is caused by the increase in the hot electron population in the region downstream of Io. We also found that the brightness depends on the system III longitude and found primary and secondary peaks in the longitude ranges of 100-130 and 250-340, respectively. Io's orbit crosses the center of the IPT around these longitudes. This longitude dependence suggests that the electron heating process is related to the plasma density around Io. The total radiated power from the IPT in January 2014 was estimated to be 1.4 TW in the wavelength range from 60 to 145 nm. The Io-correlated component produced 10% of this total radiated power. The interaction between Io and the IPT continuously produces a large amount of energy around Io, and 140 GW of that energy is immediately converted to hot electron production in the IPT.

  7. Locally smeared operator product expansions in scalar field theory

    DOE PAGESBeta

    Monahan, Christopher; Orginos, Kostas

    2015-04-01

    We propose a new locally smeared operator product expansion to decompose non-local operators in terms of a basis of smeared operators. The smeared operator product expansion formally connects nonperturbative matrix elements determined numerically using lattice field theory to matrix elements of non-local operators in the continuum. These nonperturbative matrix elements do not suffer from power-divergent mixing on the lattice, which significantly complicates calculations of quantities such as the moments of parton distribution functions, provided the smearing scale is kept fixed in the continuum limit. The presence of this smearing scale complicates the connection to the Wilson coefficients of the standardmore » operator product expansion and requires the construction of a suitable formalism. We demonstrate the feasibility of our approach with examples in real scalar field theory.« less

  8. Locally smeared operator product expansions in scalar field theory

    SciTech Connect

    Monahan, Christopher; Orginos, Kostas

    2015-04-01

    We propose a new locally smeared operator product expansion to decompose non-local operators in terms of a basis of smeared operators. The smeared operator product expansion formally connects nonperturbative matrix elements determined numerically using lattice field theory to matrix elements of non-local operators in the continuum. These nonperturbative matrix elements do not suffer from power-divergent mixing on the lattice, which significantly complicates calculations of quantities such as the moments of parton distribution functions, provided the smearing scale is kept fixed in the continuum limit. The presence of this smearing scale complicates the connection to the Wilson coefficients of the standard operator product expansion and requires the construction of a suitable formalism. We demonstrate the feasibility of our approach with examples in real scalar field theory.

  9. Cultural and environmental factors governing tomato production: Local food production under elevated temperature conditions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Long-term fresh tomato (Solanum lycopersicum L.) production data was used to estimate cultural and environmental impacts on marketable tomato yields in eastern Oklahoma. Quantifying the interactive effects of planting date and growing season duration and the effects of cumulative heat units and heat...

  10. Heat conduction in nanoscale materials: a statistical-mechanics derivation of the local heat flux.

    PubMed

    Li, Xiantao

    2014-09-01

    We derive a coarse-grained model for heat conduction in nanoscale mechanical systems. Starting with an all-atom description, this approach yields a reduced model, in the form of conservation laws of momentum and energy. The model closure is accomplished by introducing a quasilocal thermodynamic equilibrium, followed by a linear response approximation. Of particular interest is the constitutive relation for the heat flux, which is expressed nonlocally in terms of the spatial and temporal variation of the temperature. Nanowires made of copper and silicon are presented as examples. PMID:25314400

  11. HEAT TREATMENTS FOR CONTROLLING STORED PRODUCT INSECTS IN STRUCTURES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This presentation is part of a Round-table Discussion on "Organic pest management in stored-product", to be conducted at the 5th National IPM Conference. Discussion topics include advantages and disadvantages in using heat treatments, similarities with other pest control measures, problems encounter...

  12. Localized heat transfer to verticle forced flow two-phase helium

    SciTech Connect

    Panek, J.; Huang, X.; Van Sciver, S.W.

    1996-12-31

    Localized heat transfer measurements in vertical two-phase helium are reported. The test loop contains two short heat transfer sections made of 5 mm thick oxygen-free high conductivity (OFHC) copper discs. These test sections were installed in a U-shaped vertical flow loop driven by a single-stroke bellows pump. The surface temperature of each test section is measured with two germanium thermometers placed on different radial positions in each test section. With one test section placed on the downflow side and one on the upflow side of the loop, the effect of flow orientation on heat transfer characteristics in vertical two-phase helium flow is investigated. The study includes the effects of system pressure, mass flow rate, and geometry on the heat transfer coefficient, critical heat flux, and recovery heat flux.

  13. The dynamics of thermal regime changes of a local working zone in conditions of its heating by gas infrared radiators

    NASA Astrophysics Data System (ADS)

    Nee, A.

    2015-10-01

    Mathematical modeling of unsteady heat transfer in a closed rectangular area with a local heat supply object in a conjugate formulation in working conditions of radiation source of energy is passed. Fields of temperatures and stream functions, illustrating the influence of a local typical object on thermal regime are received. The effect of Grashof number on dimensionless heat transfer coefficient - Nusselt number is investigated. The influence of nonconducted heat supply object on heat transfer rate in solution domain is showed.

  14. Fundamental Study on Localized Heating in Hyperthermia Using Phase Control of Long-wavelength Microwaves

    NASA Astrophysics Data System (ADS)

    Matsumoto, Hiroshi; Ishida, Hiroki; Nakamoto, Satoshi; Takeno, Hiromasa; Yasaka, Yasuyoshi; Kawai, Shigeaki; Mitani, Tomohiko; Shinohara, Naoki; Namiki, Hironori

    For the treatment of cancer using hyperthermia, high frequency electromagnetic fields are used to heat the cancer cells. These electromagnetic fields fall into two general frequency ranges, one relatively low, and the other in the microwave range. Both produce some side effects such as the heating of healthy cells or the impact on the body of invasive surgery required to expose deep-lying cells. To reduce these side reactions, the use of lower microwave frequencies with phase control was proposed. In this paper, we present a very basic study to prove the viability of the proposed scheme. This includes the selection of a suitable frequency, demonstration of localized heating using the selected frequency, and a three-dimensional numerical analysis of the electromagnetic fields involved. In the heating demonstration, a tissue-equivalent phantom made from agar was irradiated by phase-controlled electromagnetic waves from a pair of circular patch antennas operating at 430MHz. This produced localized heating. The numerical analysis produced a field distribution that corresponded closely to the results from the heating experiment. It confirmed that the phase control technique for long-wavelength microwaves was effective in producing localized heating.

  15. Using Forecast and Observed Weather Data to Assess Performance of Forecast Products in Identifying Heat Waves and Estimating Heat Wave Effects on Mortality

    PubMed Central

    Chen, Yeh-Hsin; Schwartz, Joel D.; Rood, Richard B.; ONeill, Marie S.

    2014-01-01

    Background: Heat wave and health warning systems are activated based on forecasts of health-threatening hot weather. Objective: We estimated heatmortality associations based on forecast and observed weather data in Detroit, Michigan, and compared the accuracy of forecast products for predicting heat waves. Methods: We derived and compared apparent temperature (AT) and heat wave days (with heat waves defined as ? 2 days of daily mean AT ? 95th percentile of warm-season average) from weather observations and six different forecast products. We used Poisson regression with and without adjustment for ozone and/or PM10 (particulate matter with aerodynamic diameter ? 10 ?m) to estimate and compare associations of daily all-cause mortality with observed and predicted AT and heat wave days. Results: The 1-day-ahead forecast of a local operational product, Revised Digital Forecast, had about half the number of false positives compared with all other forecasts. On average, controlling for heat waves, days with observed AT = 25.3C were associated with 3.5% higher mortality (95% CI: 1.6, 8.8%) than days with AT = 8.5C. Observed heat wave days were associated with 6.2% higher mortality (95% CI: 0.4, 13.2%) than nonheat wave days. The accuracy of predictions varied, but associations between mortality and forecast heat generally tended to overestimate heat effects, whereas associations with forecast heat waves tended to underestimate heat wave effects, relative to associations based on observed weather metrics. Conclusions: Our findings suggest that incorporating knowledge of local conditions may improve the accuracy of predictions used to activate heat wave and health warning systems. Citation: Zhang K, Chen YH, Schwartz JD, Rood RB, ONeill MS. 2014. Using forecast and observed weather data to assess performance of forecast products in identifying heat waves and estimating heat wave effects on mortality. Environ Health Perspect 122:912918;?http://dx.doi.org/10.1289/ehp.1306858 PMID:24833618

  16. Alterations in heat loss and heat production mechanisms in rat exposed to hypergravic fields

    NASA Technical Reports Server (NTRS)

    Horowitz, J. M.; Horwitz, B. A.; Oyama, J.

    1982-01-01

    A review of studies investigating the thermal response of rats exposed to hypergravic fields well below maximum tolerance levels is presented. It is concluded that several lines of evidence indicate that the neural switching network for temperature regulation and cardiovascular channeling of blood flow is transiently affected during the first hour a rat is exposed to hypergravity. Moreover, even after one hour of exposure, when the core temperature has fallen several degrees, shivering and nonshivering thermogenesis are not fully activated. Only after prolonged exposure to hypergravic fields do heat production mechanisms recover sufficiently to bring the core temperature back to a normal level. Thus, the data indicate a more rapid recovery of effector mechanisms for heat loss than for heat production.

  17. Local heat transfer behavior and its impact on a single-row, annularly finned tube heat exchanger

    SciTech Connect

    Hu, X.; Jacobi, A.M. )

    1993-02-01

    Experimental studies of the local mass transfer characteristics of annularly finned tubes in crossflow are presented. Variations due to boundary layer development, forward-edge separation, the tube wake, horseshoe vortices, and tip vortices are discussed. In addition, regularly located local maxima in mass transfer rates associated with the horseshoe vortex system are found, and conjecture as to their mechanism is offered. Inferring heat transfer behavior from the mass transfer results, we find that the true fin efficiency is always less than that obtained with an assumed constant convective heat transfer coefficient. The difference is 3-7 percent for high-conductivity materials such as aluminum alloys, and 9-17 percent for low-conductivity materials such as mild steels. 26 refs., 7 refs., 2 tabs.

  18. Heat shock protein and heat shock factor 1 expression and localization in vaccinia virus infected human monocyte derived macrophages

    PubMed Central

    Kowalczyk, Aleksandra; Guzik, Krzysztof; Slezak, Kinga; Dziedzic, Jakub; Rokita, Hanna

    2005-01-01

    Background Viruses remain one of the inducers of the stress response in the infected cells. Heat shock response induced by vaccinia virus (VV) infection was studied in vitro in human blood monocyte derived macrophages (MDMs) as blood cells usually constitute the primary site of the infection. Methods Human blood monocytes were cultured for 12 – 14 days. The transcripts of heat shock factor 1 (HSF1), heat shock protein 70 (HSP70), heat shock protein 90 (HSP90) and two viral genes (E3L and F17R) were assayed by reverse transcriptase-polymerase chain reaction (RT-PCR), and the corresponding proteins measured by Western blot. Heat shock factor 1 DNA binding activities were estimated by electrophoretic mobility shift assay (EMSA) and its subcellular localization analyzed by immunocytofluorescence. Results It appeared that infection with vaccinia virus leads to activation of the heat shock factor 1. Activation of HSF1 causes increased synthesis of an inducible form of the HSP70 both at the mRNA and the protein level. Although HSP90 mRNA was enhanced in vaccinia virus infected cells, the HSP90 protein content remained unchanged. At the time of maximum vaccinia virus gene expression, an inhibitory effect of the infection on the heat shock protein and the heat shock factor 1 was most pronounced. Moreover, at the early phase of the infection translocation of HSP70 and HSP90 from the cytoplasm to the nucleus of the infected cells was observed. Conclusion Preferential nuclear accumulation of HSP70, the major stress-inducible chaperone protein, suggests that VV employs this particular mechanism of cytoprotection to protect the infected cell rather than to help viral replication. The results taken together with our previuos data on monocytes or MDMs infected with VV or S. aureus strongly argue that VV employs multiple cellular antiapoptotic/cytoprotective mechanisms to prolong viability and proinflammatory activity of the cells of monocytic-macrophage lineage. PMID:16246258

  19. Zak transform for semidirect product of locally compact groups

    NASA Astrophysics Data System (ADS)

    Arefijamaal, Ali Akbar; Ghaani Farashahi, Arash

    2013-09-01

    Let be a locally compact group and be an LCA group also let be a continuous homomorphism and be the semidirect product of and with respect to . In this article we define the Zak transform on with respect to a -invariant uniform lattice of and we also show that the Zak transform satisfies the Plancherel formula. As an application we analyze how these technique apply for the semidirect product group and also the Weyl-Heisenberg groups.

  20. r-process Lanthanide Production and Heating Rates in Kilonovae

    NASA Astrophysics Data System (ADS)

    Lippuner, Jonas; Roberts, Luke F.

    2015-12-01

    r-process nucleosynthesis in material ejected during neutron star mergers may lead to radioactively powered transients called kilonovae. The timescale and peak luminosity of these transients depend on the composition of the ejecta, which determines the local heating rate from nuclear decays and the opacity. Kasen et al. and Tanaka & Hotokezaka pointed out that lanthanides can drastically increase the opacity in these outflows. We use the new general-purpose nuclear reaction network SkyNet to carry out a parameter study of r-process nucleosynthesis for a range of initial electron fractions Ye, initial specific entropies s, and expansion timescales τ. We find that the ejecta is lanthanide-free for Ye ≳ 0.22-0.30, depending on s and τ. The heating rate is insensitive to s and τ, but certain, larger values of Ye lead to reduced heating rates, due to individual nuclides dominating the heating. We calculate approximate light curves with a simplified gray radiative transport scheme. The light curves peak at about a day (week) in the lanthanide-free (-rich) cases. The heating rate does not change much as the ejecta becomes lanthanide-free with increasing Ye, but the light-curve peak becomes about an order of magnitude brighter because it peaks much earlier when the heating rate is larger. We also provide parametric fits for the heating rates between 0.1 and 100 days, and we provide a simple fit in Ye, s, and τ to estimate whether or not the ejecta is lanthanide-rich.

  1. Quantitative analysis of the local phase transitions induced by the laser heating

    DOE PAGESBeta

    Levlev, Anton V.; Susner, Michael A.; McGuire, Michael A.; Maksymovych, Petro; Kalinin, Sergei V.

    2015-11-04

    Functional imaging enabled by scanning probe microscopy (SPM) allows investigations of nanoscale material properties under a wide range of external conditions, including temperature. However, a number of shortcomings preclude the use of the most common material heating techniques, thereby limiting precise temperature measurements. Here we discuss an approach to local laser heating on the micron scale and its applicability for SPM. We applied local heating coupled with piezoresponse force microscopy and confocal Raman spectroscopy for nanoscale investigations of a ferroelectric-paraelectric phase transition in the copper indium thiophosphate layered ferroelectric. Bayesian linear unmixing applied to experimental results allowed extraction of themore » Raman spectra of different material phases and enabled temperature calibration in the heated region. Lastly, the obtained results enable a systematic approach for studying temperature-dependent material functionalities in heretofore unavailable temperature regimes.« less

  2. Quantitative Analysis of the Local Phase Transitions Induced by Laser Heating.

    PubMed

    Ievlev, Anton V; Susner, Michael A; McGuire, Michael A; Maksymovych, Petro; Kalinin, Sergei V

    2015-12-22

    Functional imaging enabled by scanning probe microscopy (SPM) allows investigations of nanoscale material properties under a wide range of external conditions, including temperature. However, a number of shortcomings preclude the use of the most common material heating techniques, thereby limiting precise temperature measurements. Here we discuss an approach to local laser heating on the micron scale and its applicability for SPM. We applied local heating coupled with piezoresponse force microscopy and confocal Raman spectroscopy for nanoscale investigations of a ferroelectric-paraelectric phase transition in the copper indium thiophosphate layered ferroelectric. Bayesian linear unmixing applied to experimental results allowed extraction of the Raman spectra of different material phases and enabled temperature calibration in the heated region. The obtained results enable a systematic approach for studying temperature-dependent material functionalities in heretofore unavailable temperature regimes. PMID:26536387

  3. Quantitative analysis of the local phase transitions induced by the laser heating

    SciTech Connect

    Levlev, Anton V.; Susner, Michael A.; McGuire, Michael A.; Maksymovych, Petro; Kalinin, Sergei V.

    2015-11-04

    Functional imaging enabled by scanning probe microscopy (SPM) allows investigations of nanoscale material properties under a wide range of external conditions, including temperature. However, a number of shortcomings preclude the use of the most common material heating techniques, thereby limiting precise temperature measurements. Here we discuss an approach to local laser heating on the micron scale and its applicability for SPM. We applied local heating coupled with piezoresponse force microscopy and confocal Raman spectroscopy for nanoscale investigations of a ferroelectric-paraelectric phase transition in the copper indium thiophosphate layered ferroelectric. Bayesian linear unmixing applied to experimental results allowed extraction of the Raman spectra of different material phases and enabled temperature calibration in the heated region. Lastly, the obtained results enable a systematic approach for studying temperature-dependent material functionalities in heretofore unavailable temperature regimes.

  4. Transient mass transfer caused by local surface heating in close binaries

    NASA Technical Reports Server (NTRS)

    Modisette, J. J.; Kondo, Y.

    1980-01-01

    The surge of mass from one component of a binary system resulting from local surface heating is analyzed. The impact of such surges on the companion can produce transient phenomena such as those seen in X-ray binaries, RS CVn objects, and cataclysmic variables. The heating may be caused by nonlinear g-mode oscillations or by X-ray heating by the companion in X-ray binaries, among other possible mechanisms. As an example, model calculations have been performed for a surge, triggered by a relatively moderate local heating, in a hypothetical X-ray binary; the results show that such a surge can account for X-ray turn-ons.

  5. Self-generated Local Heating Induced Nanojoining for Room Temperature Pressureless Flexible Electronic Packaging

    PubMed Central

    Peng, Peng; Hu, Anming; Gerlich, Adrian P.; Liu, Yangai; Zhou, Y. Norman

    2015-01-01

    Metallic bonding at an interface is determined by the application of heat and/or pressure. The means by which these are applied are the most critical for joining nanoscale structures. The present study considers the feasibility of room-temperature pressureless joining of copper wires using water-based silver nanowire paste. A novel mechanism of self-generated local heating within the silver nanowire paste and copper substrate system promotes the joining of silver-to-silver and silver-to-copper without any external energy input. The localized heat energy was delivered in-situ to the interfaces to promote atomic diffusion and metallic bond formation with the bulk component temperature stays near room-temperature. This local heating effect has been detected experimentally and confirmed by calculation. The joints formed at room-temperature without pressure achieve a tensile strength of 5.7 MPa and exhibit ultra-low resistivity in the range of 101.3 nOhm·m. The good conductivity of the joint is attributed to the removal of organic compounds in the paste and metallic bonding of silver-to-copper and silver-to-silver. The water-based silver nanowire paste filler material is successfully applied to various flexible substrates for room temperature bonding. The use of chemically generated local heating may become a potential method for energy in-situ delivery at micro/nanoscale. PMID:25788019

  6. Self-generated Local Heating Induced Nanojoining for Room Temperature Pressureless Flexible Electronic Packaging

    NASA Astrophysics Data System (ADS)

    Peng, Peng; Hu, Anming; Gerlich, Adrian P.; Liu, Yangai; Zhou, Y. Norman

    2015-03-01

    Metallic bonding at an interface is determined by the application of heat and/or pressure. The means by which these are applied are the most critical for joining nanoscale structures. The present study considers the feasibility of room-temperature pressureless joining of copper wires using water-based silver nanowire paste. A novel mechanism of self-generated local heating within the silver nanowire paste and copper substrate system promotes the joining of silver-to-silver and silver-to-copper without any external energy input. The localized heat energy was delivered in-situ to the interfaces to promote atomic diffusion and metallic bond formation with the bulk component temperature stays near room-temperature. This local heating effect has been detected experimentally and confirmed by calculation. The joints formed at room-temperature without pressure achieve a tensile strength of 5.7 MPa and exhibit ultra-low resistivity in the range of 101.3 nOhm.m. The good conductivity of the joint is attributed to the removal of organic compounds in the paste and metallic bonding of silver-to-copper and silver-to-silver. The water-based silver nanowire paste filler material is successfully applied to various flexible substrates for room temperature bonding. The use of chemically generated local heating may become a potential method for energy in-situ delivery at micro/nanoscale.

  7. Self-generated local heating induced nanojoining for room temperature pressureless flexible electronic packaging.

    PubMed

    Peng, Peng; Hu, Anming; Gerlich, Adrian P; Liu, Yangai; Zhou, Y Norman

    2015-01-01

    Metallic bonding at an interface is determined by the application of heat and/or pressure. The means by which these are applied are the most critical for joining nanoscale structures. The present study considers the feasibility of room-temperature pressureless joining of copper wires using water-based silver nanowire paste. A novel mechanism of self-generated local heating within the silver nanowire paste and copper substrate system promotes the joining of silver-to-silver and silver-to-copper without any external energy input. The localized heat energy was delivered in-situ to the interfaces to promote atomic diffusion and metallic bond formation with the bulk component temperature stays near room-temperature. This local heating effect has been detected experimentally and confirmed by calculation. The joints formed at room-temperature without pressure achieve a tensile strength of 5.7 MPa and exhibit ultra-low resistivity in the range of 101.3 nOhm · m. The good conductivity of the joint is attributed to the removal of organic compounds in the paste and metallic bonding of silver-to-copper and silver-to-silver. The water-based silver nanowire paste filler material is successfully applied to various flexible substrates for room temperature bonding. The use of chemically generated local heating may become a potential method for energy in-situ delivery at micro/nanoscale. PMID:25788019

  8. Quality assessment of palm products upon prolonged heat treatment.

    PubMed

    Tarmizi, Azmil Haizam Ahmad; Lin, Siew Wai

    2008-01-01

    Extending the frying-life of oils is of commercial and economic importance. Due to this fact, assessment on the thermal stability of frying oils could provide considerable savings to the food processors. In this study, the physico-chemical properties of five palm products mainly palm oil, single-fractionated palm olein, double-fractionated palm olein, red palm olein and palm-based shortening during 80 hours of heating at 180 degrees C were investigated. Heating properties of these products were then compared with that of high oleic sunflower oil, which was used as reference oil. The indices applied in evaluating the quality changes of oils were free fatty acid, smoke point, p-anisidine value, tocols, polar and polymer compounds. Three palm products i.e. palm oil, single-fractionated palm olein and double-fractionated palm olein were identified to be the most stable in terms of lower formation of free fatty acid, polar and polymer compounds as well as preserving higher smoke point and tocols content compared to the other three oils. The low intensity of hydrolytic and oxidative changes due to prolonged heating, suggests that these palm products are inherently suitable for frying purposes. PMID:19001776

  9. Local energy dissipation rate balances local heat flux in the center of turbulent thermal convection.

    PubMed

    Ni, Rui; Huang, Shi-Di; Xia, Ke-Qing

    2011-10-21

    The local kinetic energy dissipation rate ?(u,c) in Rayleigh-Bnard convection cell was measured experimentally using the particle tracking velocimetry method, with varying Rayleigh number Ra, Prandtl number Pr, and cell height H. It is found that ?(u,c)/(?(3)H(-4))=1.0510(-4)Ra(1.550.02)Pr(1.150.38). The Ra and H dependencies of the measured results are found to be consistent with the assumption made for the bulk energy dissipation rate ?(u,bulk) in the Grossmann-Lohse model. A remarkable finding of the study is that ?(u,c) balances the directly measured local Nusselt number Nu(c) in the cell center, not only scalingwise but also in magnitude. PMID:22107524

  10. Localized Heating on Silicon Field Effect Transistors: Device Fabrication and Temperature Measurements in Fluid

    PubMed Central

    Elibol, Oguz H.; Reddy, Bobby; Nair, Pradeep R.; Dorvel, Brian; Butler, Felice; Ahsan, Zahab; Bergstrom, Donald E.; Alam, Muhammad A.; Bashir, Rashid

    2010-01-01

    We demonstrate electrically addressable localized heating in fluid at the dielectric surface of silicon-on-insulator field-effect transistors via radio-frequency Joule heating of mobile ions in the Debye layer. Measurement of fluid temperatures in close vicinity to surfaces poses a challenge due to the localized nature of the temperature profile. To address this, we developed a localized thermometry technique based on the fluorescence decay rate of covalently attached fluorophores to extract the temperature within 2 nm of any oxide surface. We demonstrate precise spatial control of voltage dependent temperature profiles on the transistor surfaces. Our results introduce a new dimension to present sensing systems by enabling dual purpose silicon transistor-heaters that serve both as field effect sensors as well as temperature controllers that could perform localized bio-chemical reactions in Lab on Chip applications. PMID:19967115

  11. Heat Transfer and Fluid Transport of Supercritical CO2 in Enhanced Geothermal System with Local Thermal Non-equilibrium Model

    SciTech Connect

    Zhang, Le; Luo, Feng; Xu, Ruina; Jiang, Peixue; Liu, Huihai

    2014-12-31

    The heat transfer and fluid transport of supercritical CO2 in enhanced geothermal system (EGS) is studied numerically with local thermal non-equilibrium model, which accounts for the temperature difference between solid matrix and fluid components in porous media and uses two energy equations to describe heat transfer in the solid matrix and in the fluid, respectively. As compared with the previous results of our research group, the effect of local thermal non-equilibrium mainly depends on the volumetric heat transfer coefficient ah, which has a significant effect on the production temperature at reservoir outlet and thermal breakthrough time. The uniformity of volumetric heat transfer coefficient ah has little influence on the thermal breakthrough time, but the temperature difference become more obvious with time after thermal breakthrough with this simulation model. The thermal breakthrough time reduces and the effect of local thermal non-equilibrium becomes significant with decreasing ah.

  12. Local modification of GaAs nanowires induced by laser heating

    NASA Astrophysics Data System (ADS)

    Yazji, S.; Zardo, I.; Soini, M.; Postorino, P.; Morral, A. Fontcuberta i.; Abstreiter, G.

    2011-08-01

    GaAs nanowires were heated locally under ambient air conditions by a focused laser beam which led to oxidation and formation of crystalline arsenic on the nanowire surface. Atomic force microscopy, photoluminescence and Raman spectroscopy experiments were performed on the same single GaAs nanowires in order to correlate their structural and optical properties. We show that the local changes of the nanowires act as a barrier for thermal transport which is of interest for thermoelectric applications.

  13. Method of preparing a high heating value fuel product

    SciTech Connect

    Somerville, R.; Fan, L.T.

    1989-10-24

    This patent describes a method of preparing a high heating value fuel product. The method comprising the steps of: blending a high heating value waste material with a cellulosic material; mixing an organic reagent to the blended mixture of the waste material and the cellulosic material, the organic reagent being a mixture having a 4-15 weight percent of a chemical selected from the group consisting of: triethylene, glycol, diethylene glycol, and glycerin propylene glycol; introducing a pozzolanic agent to the blended mixture for controlling the rate of solidification; and forming the blended mixture into a form suitable for handling. Also described is the same method with the mixture of the organic reagent further comprising: a 20-32 weight percent calcium chloride solution. Another method of preparing a fuel product is also described.

  14. Geothermal Energy Production With Innovative Methods Of Geothermal Heat Recovery

    SciTech Connect

    Swenson, Allen; Darlow, Rick; Sanchez, Angel; Pierce, Michael; Sellers, Blake

    2014-12-19

    The ThermalDrive™ Power System (“TDPS”) offers one of the most exciting technological advances in the geothermal power generation industry in the last 30 years. Using innovations in subsurface heat recovery methods, revolutionary advances in downhole pumping technology and a distributed approach to surface power production, GeoTek Energy, LLC’s TDPS offers an opportunity to change the geothermal power industry dynamics.

  15. Heat flow and heat production in the Arkoma Basin and Oklahoma Platform, southeastern Oklahoma

    NASA Astrophysics Data System (ADS)

    Lee, Youngmin; Deming, David; Chen, Kevin F.

    1996-11-01

    Subsurface temperature and thermal gradients along a north-south cross section through the Arkoma Basin and the Oklahoma Platform in southeastern Oklahoma were estimated from 345 bottom hole temperatures from 199 oil and gas wells. The average geothermal gradient in the southern part of the basin near the Ouachita Front is 20C/km, exceeds 30C/km in the middle part of the basin, and is 24C/km on the Oklahoma Platform to the north. Drill cuttings obtained from 11 oil and gas wells were used for 843 thermal conductivity measurements. Thermal conductivity data, corrected to in situ conditions, were used to estimate heat flow. Estimated heat flow (20%) in the deep part of the Arkoma Basin near the Ouachita Front is 35-40 mW/m2 and increases systematically northward to 60-65 mW/m2 on the Oklahoma Platform. Average heat production, estimated from gamma ray logs, is 2.3 0.2 ?W/m3 for basement rocks underlying the Arkoma Basin and 2.8 0.1 ?W/m3 for basement rocks in the Oklahoma Platform area. Numerical models show that heat refraction from the less conductive sedimentary rocks (1.6 W/mK) of the Arkoma Basin to the more conductive crystalline rocks (3.0 W/mK at 25C) of the Oklahoma Platform and the Ouachita Mountains accounts for about 5-10 mW/m2 of the observed 20-30 mW/m2 decrease in heat flow from north to south. Changes in crustal heat production related to compositional changes and crustal thinning account for another 5-15 mW/m2 of the observed heat flow change. If the remaining 0-20 mW/m2 difference in heat flow is attributed to heat transport by topographically driven groundwater flow, the average basin-scale permeability of the Arkoma Basin and the Oklahoma Platform can be no greater than 10-15 m2. Results of this study are not generally supportive of theories which invoke topographically driven regional groundwater flow from the Arkoma Basin in Late Pennsylvanian-Early Permian time (290 Ma) to explain the genesis of Mississippi Valley-type lead-zinc deposits, paleothermal anomalies, and regional diagenesis in the North American midcontinent.

  16. 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.

  17. Local Heat Flux Measurements with Single and Small Multi-element Coaxial Element-Injectors

    NASA Technical Reports Server (NTRS)

    Jones, Gregg; Protz, Christopher; Bullard, Brad; Hulka, James

    2006-01-01

    To support NASA's Vision for Space Exploration mission, the NASA Marshall Space Flight Center conducted a program in 2005 to improve the capability to predict local thermal compatibility and heat transfer in liquid propellant rocket engine combustion devices. The ultimate objective was to predict and hence reduce the local peak heat flux due to injector design, resulting in a significant improvement in overall engine reliability and durability. Such analyses are applicable to combustion devices in booster, upper stage, and in-space engines with regeneratively cooled chamber walls, as well as in small thrust chambers with few elements in the injector. In this program, single and three-element injectors were hot-fire tested with liquid oxygen and gaseous hydrogen propellants at The Pennsylvania State University Cryogenic Combustor Laboratory from May to August 2005. Local heat fluxes were measured in a 1-inch internal diameter heat sink combustion chamber using Medtherm coaxial thermocouples and Gardon heat flux gauges, Injector configurations were tested with both shear coaxial elements and swirl coaxial elements. Both a straight and a scarfed single element swirl injector were tested. This paper includes general descriptions of the experimental hardware, instrumentation, and results of the hot-fire testing for three coaxial shear and swirl elements. Detailed geometry and test results the for shear coax elements has already been published. Detailed test result for the remaining 6 swirl coax element for the will be published in a future JANNAF presentation to provide well-defined data sets for development and model validation.

  18. Birch's Crustal Heat Production-Heat Flow Law: Key to Quantifying Mantle Heat Flow as a function of time

    NASA Astrophysics Data System (ADS)

    Blackwell, D. D.; Thakur, M.

    2007-12-01

    Birch (1968) first showed the linear correlation of surface heat flow and radioactive heat production (Qs = Qo + bAs ) in granites in New England, USA and discussed implications to the vertical scale of radioactive heat generation in the crust. Subsequently similar relationships have been found worldwide and numerous papers written describing more details and expanding the implications of Birch's Law. The results are a powerful contribution from heat flow research to the understanding of the lithosphere and its evolution. Models are both well constrained experimentally and simple in implications. However, there still exist thermal models of the crust and lithosphere that do not have the same firm foundation and involve unnecessary ad hoc assumptions. A main point of confusion has been that the several of the original relationships were so low in error as to be considered by some to be "fortuitous". Interestingly a "similar" relationship has been proposed based on regional scale averaging of Qs -As data. A second point of confusion is that one admissible crustal radioactivity distribution model (the constant heat generation to depth b) has been criticized as unrealistic for a number of reasons, including the effect of erosion. However, it is appropriate to refer to the Qs -As relationship as a law because in fact the relationship holds as long as the vertical distribution is "geologically realistic." as will be demonstrated in this paper. All geologic and geophysical models of the continental crust imply decreasing heat production as a function of depth (i.e. the seismic layering for example) except in very special cases. This general decrease with depth is the only condition required for the existence of a "linear" Qs -As relationship. A comparison of all the Qs -As relationships proposed for terrains not affected by thermal events over the last 150 to 200 Ma shows a remarkably uniformity in slope (10 3 km) and intercept value (30 5 mWm-2 ). Therefore these parameters of Birch's Law equation represent the starting place for discussions of lithospheric thermal regime and evolution. The stability of the values of intercept Qo for areas with thermal ages of Paleozoic and older prove that the lithosphere heat flow does not vary significantly with age as is demonstrated in the companion paper. The minimum mantle heat flow for preMesozoic thermal terrains is 20 - 25 mWm-2. This value is consistent with the lack of indication from xenolith data that lithosphere thickness changes with age and with theoretical models of mantle convection.

  19. A New Model for Heat Flow in Extensional Basins: Estimating Radiogenic Heat Production

    SciTech Connect

    Waples, Douglas W.

    2002-06-15

    Radiogenic heat production (RHP) represents a significant fraction of surface heat flow, both on cratons and in sedimentary basins. RHP within continental crust-especially the upper crust-is high. RHP at any depth within the crust can be estimated as a function of crustal age. Mantle RHP, in contrast, is always low, contributing at most 1 to 2 mW/m{sup 2} to total heat flow. Radiogenic heat from any noncrystalline basement that may be present also contributes to total heat flow. RHP from metamorphic rocks is similar to or slightly lower than that from their precursor sedimentary rocks. When extension of the lithosphere occurs-as for example during rifting-the radiogenic contribution of each layer of the lithosphere and noncrystalline basement diminishes in direct proportion to the degree of extension of that layer. Lithospheric RHP today is somewhat less than in the distant past, as a result of radioactive decay. In modeling, RHP can be varied through time by considering the half lives of uranium, thorium, and potassium, and the proportional contribution of each of those elements to total RHP from basement. RHP from sedimentary rocks ranges from low for most evaporites to high for some shales, especially those rich in organic matter. The contribution to total heat flow of radiogenic heat from sediments depends strongly on total sediment thickness, and thus differs through time as subsidence and basin filling occur. RHP can be high for thick clastic sections. RHP in sediments can be calculated using ordinary or spectral gamma-ray logs, or it can be estimated from the lithology.

  20. Constant Temperature Storage House Heated by the Respiration Heat of Agricultural Products

    NASA Astrophysics Data System (ADS)

    Kobiyama, Masayoshi; Takegata, Kiyohide; Hashimoto, Yoshiaki; Kawamoto, Syuroh; Ohno, Syozi

    HIMURO type storage house, cooled by natural snow/ice, has been practically applied by means of its good storing condition and of the easy handling. As this type storage house is constructed by enough insulation structure, it can been used not only for a cool house in the summer but also a constant temperature storage house in the winter. In this paper, the authors suggested that the HIMURO type storage house might be used as the constant temperature house in the severe cold winter season after the theoretical investigation on the thermal characteristics of it. In general, the conventional type constant temperature storage house is heated by heater throughout storing period, that of this paper is self heated by the respiration heat of agricultural products stored in this house, so the house proposed in this paper look forward to smaller heat addition than that of conventional house. The practical experiment was performed to verify the theoretical investigation and to observe the storing condition of the product and we obtained enough results.

  1. Novel localized heating technique on centrifugal microfluidic disc with wireless temperature monitoring system.

    PubMed

    Joseph, Karunan; Ibrahim, Fatimah; Jongman Cho

    2015-08-01

    Recent advances in the field of centrifugal microfluidic disc suggest the need for electrical interface in the disc to perform active biomedical assays. In this paper, we have demonstrated an active application powered by the energy harvested from the rotation of the centrifugal microfluidic disc. A novel integration of power harvester disc onto centrifugal microfluidic disc to perform localized heating technique is the main idea of our paper. The power harvester disc utilizing electromagnetic induction mechanism generates electrical energy from the rotation of the disc. This contributes to the heat generation by the embedded heater on the localized heating disc. The main characteristic observed in our experiment is the heating pattern in relative to the rotation of the disc. The heating pattern is monitored wirelessly with a digital temperature sensing system also embedded on the disc. Maximum temperature achieved is 82 °C at rotational speed of 2000 RPM. The technique proves to be effective for continuous heating without the need to stop the centrifugal motion of the disc. PMID:26736977

  2. Optical cable fault locating using Brillouin optical time domain reflectometer and cable localized heating method

    NASA Astrophysics Data System (ADS)

    Lu, Y. G.; Zhang, X. P.; Dong, Y. M.; Wang, F.; Liu, Y. H.

    2007-07-01

    A novel optical cable fault location method, which is based on Brillouin optical time domain reflectometer (BOTDR) and cable localized heating, is proposed and demonstrated. In the method, a BOTDR apparatus is used to measure the optical loss and strain distribution along the fiber in an optical cable, and a heating device is used to heat the cable at its certain local site. Actual experimental results make it clear that the proposed method works effectively without complicated calculation. By means of the new method, we have successfully located the optical cable fault in the 60 km optical fiber composite power cable from Shanghai to Shengshi, Zhejiang. A fault location accuracy of 1 meter was achieved. The fault location uncertainty of the new optical cable fault location method is at least one order of magnitude smaller than that of the traditional OTDR method.

  3. Temperature distribution in tissues subjected to local hyperthermia by RF induction heating.

    PubMed Central

    Hand, J. W.; Ledda, J. L.; Evans, T. S.

    1982-01-01

    We have used a finite difference formulation of the bio-heat transfer equation to predict temperature distributions in and around a non-uniformly perfused volume located in layered tissue. Using available data on blood flow in experimental tumours we have shown that techniques capable of highly localized heating are required to treat small, well perfused tumours effectively. However, the r.f. technique considered here produces acceptable temperature distributions in larger tumours with poorly perfused centres. Skin cooling improves the effective penetration of the hyperthermal treatment and may improve the uniformity of heating. However, the considerable heat flux through superficial tissues associated with chilled water cooling can produce large temperature gradients in such regions. PMID:6950769

  4. Spatial control of chemical processes on nanostructures through nano-localized water heating.

    PubMed

    Jack, Calum; Karimullah, Affar S; Tullius, Ryan; Khorashad, Larousse Khosravi; Rodier, Marion; Fitzpatrick, Brian; Barron, Laurence D; Gadegaard, Nikolaj; Lapthorn, Adrian J; Rotello, Vincent M; Cooke, Graeme; Govorov, Alexander O; Kadodwala, Malcolm

    2016-01-01

    Optimal performance of nanophotonic devices, including sensors and solar cells, requires maximizing the interaction between light and matter. This efficiency is optimized when active moieties are localized in areas where electromagnetic (EM) fields are confined. Confinement of matter in these 'hotspots' has previously been accomplished through inefficient 'top-down' methods. Here we report a rapid 'bottom-up' approach to functionalize selective regions of plasmonic nanostructures that uses nano-localized heating of the surrounding water induced by pulsed laser irradiation. This localized heating is exploited in a chemical protection/deprotection strategy to allow selective regions of a nanostructure to be chemically modified. As an exemplar, we use the strategy to enhance the biosensing capabilities of a chiral plasmonic substrate. This novel spatially selective functionalization strategy provides new opportunities for efficient high-throughput control of chemistry on the nanoscale over macroscopic areas for device fabrication. PMID:26961708

  5. A Transport Model for Non-Local Heating of Electrons in ICP Reactors

    NASA Technical Reports Server (NTRS)

    Chang, C. H.; Bose, Deepak; Arnold, James O. (Technical Monitor)

    1998-01-01

    A new model has been developed for non-local heating of electrons in ICP reactors, based on a hydrodynamic approach. The model has been derived using the electron momentum conservation in azimuthal direction with electromagnetic and frictional forces respectively as driving force and damper of harmonic oscillatory motion of electrons. The resulting transport equations include the convection of azimuthal electron momentum in radial and axial directions, thereby accounting for the non-local effects. The azimuthal velocity of electrons and the resulting electrical current are coupled to the Maxwell's relations, thus forming a self-consistent model for non-local heating. This model is being implemented along with a set of Navier-Stokes equations for plasma dynamics and gas flow to simulate low-pressure (few mTorr's) ICP discharges. Characteristics of nitrogen plasma in a TCP 300mm etch reactor is being studied. The results will be compared against the available Langmuir probe measurements.

  6. Spatial control of chemical processes on nanostructures through nano-localized water heating

    PubMed Central

    Jack, Calum; Karimullah, Affar S.; Tullius, Ryan; Khorashad, Larousse Khosravi; Rodier, Marion; Fitzpatrick, Brian; Barron, Laurence D.; Gadegaard, Nikolaj; Lapthorn, Adrian J.; Rotello, Vincent M.; Cooke, Graeme; Govorov, Alexander O.; Kadodwala, Malcolm

    2016-01-01

    Optimal performance of nanophotonic devices, including sensors and solar cells, requires maximizing the interaction between light and matter. This efficiency is optimized when active moieties are localized in areas where electromagnetic (EM) fields are confined. Confinement of matter in these ‘hotspots' has previously been accomplished through inefficient ‘top-down' methods. Here we report a rapid ‘bottom-up' approach to functionalize selective regions of plasmonic nanostructures that uses nano-localized heating of the surrounding water induced by pulsed laser irradiation. This localized heating is exploited in a chemical protection/deprotection strategy to allow selective regions of a nanostructure to be chemically modified. As an exemplar, we use the strategy to enhance the biosensing capabilities of a chiral plasmonic substrate. This novel spatially selective functionalization strategy provides new opportunities for efficient high-throughput control of chemistry on the nanoscale over macroscopic areas for device fabrication. PMID:26961708

  7. Localized self-heating in large arrays of 1D nanostructures.

    PubMed

    Monereo, O; Illera, S; Varea, A; Schmidt, M; Sauerwald, T; Schütze, A; Cirera, A; Prades, J D

    2016-02-25

    One dimensional (1D) nanostructures offer a promising path towards highly efficient heating and temperature control in integrated microsystems. The so called self-heating effect can be used to modulate the response of solid state gas sensor devices. In this work, efficient self-heating was found to occur at random networks of nanostructured systems with similar power requirements to highly ordered systems (e.g. individual nanowires, where their thermal efficiency was attributed to the small dimensions of the objects). Infrared thermography and Raman spectroscopy were used to map the temperature profiles of films based on random arrangements of carbon nanofibers during self-heating. Both the techniques demonstrate consistently that heating concentrates in small regions, the here-called "hot-spots". On correlating dynamic temperature mapping with electrical measurements, we also observed that these minute hot-spots rule the resistance values observed macroscopically. A physical model of a random network of 1D resistors helped us to explain this observation. The model shows that, for a given random arrangement of 1D nanowires, current spreading through the network ends up defining a set of spots that dominate both the electrical resistance and power dissipation. Such highly localized heating explains the high power savings observed in larger nanostructured systems. This understanding opens a path to design highly efficient self-heating systems, based on random or pseudo-random distributions of 1D nanostructures. PMID:26868599

  8. Effects of heat on workers' health and productivity in Taiwan

    PubMed Central

    Lin, Ro-Ting; Chan, Chang-Chuan

    2009-01-01

    Background The impact of global warming on population health is a growing concern and has been widely discussed. The issue of heat stress disorders and consequent productivity reduction among workers has not yet been widely addressed. Taiwan is an island straddling the Tropic of Cancer in the West Pacific and has both subtropical and tropical climates. As of 2008, the economy of Taiwan accounts for 1.1% of the world gross domestic product at purchasing power parity and is listed as 19th in the world and eighth in Asia, according to International Monetary Fund data. Objective The aim of this paper is to identify occupations at risk and the potential health impacts of heat on workers in Taiwan. Design Historical data relating to meteorology, population, the labour force and economy were obtained from publicly available databases from the Taiwanese government. Results Hot seasons with an average maximum temperature above 30C and relative humidity above 74%, lasting for four to six months from May to October, pose health threats to construction, farming and fishery workers. In particular, populations of ageing farmers and physically overloaded construction workers are the two most vulnerable worker categories in which high temperature impacts on health and productivity. Conclusions Currently, regulations and preventive actions for heat relief are difficult to enforce for several reasons, including lack of equipment for measuring environmental conditions, lack of awareness of potential hazards and strict time constraints imposed on workers. There is an urgent need to systematically and comprehensively assess the impact of a warming climate on workers health and productivity to provide effective prevention strategies for a better working and living environment in Taiwan. PMID:20052376

  9. Hydrogen production from coal using a nuclear heat source

    NASA Technical Reports Server (NTRS)

    Quade, R. N.

    1976-01-01

    A strong candidate for hydrogen production in the intermediate time frame of 1985 to 1995 is a coal-based process using a high-temperature gas-cooled reactor (HTGR) as a heat source. Expected process efficiencies in the range of 60 to 70% are considerably higher than all other hydrogen production processes except steam reforming of a natural gas. The process involves the preparation of a coal liquid, hydrogasification of that liquid, and steam reforming of the resulting gaseous or light liquid product. A study showing process efficiency and cost of hydrogen vs nuclear reactor core outlet temperature has been completed, and shows diminishing returns at process temperatures above about 1500 F. A possible scenario combining the relatively abundant and low-cost Western coal deposits with the Gulf Coast hydrogen users is presented which provides high-energy density transportation utilizing coal liquids and uranium.

  10. Nonequilibrium fluctuation-dissipation theorem and heat production.

    PubMed

    Lippiello, E; Baiesi, M; Sarracino, A

    2014-04-11

    We use a relationship between response and correlation function in nonequilibrium systems to establish a connection between the heat production and the deviations from the equilibrium fluctuation-dissipation theorem. This scheme extends the Harada-Sasa formulation [Phys. Rev. Lett. 95, 130602 (2005)], obtained for Langevin equations in steady states, as it also holds for transient regimes and for discrete jump processes involving small entropic changes. Moreover, a general formulation includes two times and the new concepts of two-time work, kinetic energy, and of a two-time heat exchange that can be related to a nonequilibrium effective temperature. Numerical simulations of a chain of anharmonic oscillators and of a model for a molecular motor driven by adenosine triphosphate hydrolysis illustrate these points. PMID:24765939

  11. Nonequilibrium Fluctuation-Dissipation Theorem and Heat Production

    NASA Astrophysics Data System (ADS)

    Lippiello, E.; Baiesi, M.; Sarracino, A.

    2014-04-01

    We use a relationship between response and correlation function in nonequilibrium systems to establish a connection between the heat production and the deviations from the equilibrium fluctuation-dissipation theorem. This scheme extends the Harada-Sasa formulation [Phys. Rev. Lett. 95, 130602 (2005)], obtained for Langevin equations in steady states, as it also holds for transient regimes and for discrete jump processes involving small entropic changes. Moreover, a general formulation includes two times and the new concepts of two-time work, kinetic energy, and of a two-time heat exchange that can be related to a nonequilibrium "effective temperature." Numerical simulations of a chain of anharmonic oscillators and of a model for a molecular motor driven by adenosine triphosphate hydrolysis illustrate these points.

  12. A Framework for Spatial Assessment of Local Level Vulnerability and Adaptive Capacity to Extreme Heat

    NASA Astrophysics Data System (ADS)

    Wilhelmi, O.; Hayden, M.; Harlan, S.; Ruddell, D.; Komatsu, K.; England, B.; Uejio, C.

    2008-12-01

    Changing climate is predicted to increase the intensity and impacts of heat waves prompting the need to develop preparedness and adaptation strategies that reduce societal vulnerability. Central to understanding societal vulnerability, is adaptive capacity, the potential of a system or population to modify its features/behaviors so as to better cope with existing and anticipated stresses and fluctuations. Adaptive capacity influences adaptation, the actual adjustments made to cope with the impacts from current and future hazardous heat events. Understanding societal risks, vulnerabilities and adaptive capacity to extreme heat events and climate change requires an interdisciplinary approach that includes information about weather and climate, the natural and built environment, social processes and characteristics, interactions with the stakeholders, and an assessment of community vulnerability. This project presents a framework for an interdisciplinary approach and a case study that explore linkages between quantitative and qualitative data for a more comprehensive understanding of local level vulnerability and adaptive capacity to extreme heat events in Phoenix, Arizona. In this talk, we will present a methodological framework for conducting collaborative research on societal vulnerability and adaptive capacity on a local level that includes integration of household surveys into a quantitative spatial assessment of societal vulnerability. We highlight a collaborative partnership among researchers, community leaders and public health officials. Linkages between assessment of local adaptive capacity and development of regional climate change adaptation strategies will be discussed.

  13. Modelling of shape memory polymer sheets that self-fold in response to localized heating.

    PubMed

    Mailen, Russell W; Liu, Ying; Dickey, Michael D; Zikry, Mohammed; Genzer, Jan

    2015-10-21

    We report a nonlinear finite element analysis (FEA) of the thermo-mechanical shrinking and self-folding behavior of pre-strained polystyrene polymer sheets. Self-folding is useful for actuation, packaging, and remote deployment of flat surfaces that convert to 3D objects in response to a stimulus such as heat. The proposed FEA model accounts for the viscoelastic recovery of pre-strained polystyrene sheets in response to localized heating on the surface of the polymer. Herein, the heat results from the localized absorption of light by ink patterned on the surface of the sheet. This localized delivery of heat results in a temperature gradient through the thickness of the sheet, and thus a gradient of strain recovery, or shrinkage, develops causing the polymer sheet to fold. This process transforms a 2D pattern into a 3D shape through an origami-like behavior. The FEA predictions indicate that shrinking and folding are sensitive to the thermo-mechanical history of the polymer during pre-straining. The model also shows that shrinkage does not vary linearly through the thickness of the polymer during folding due to the accumulation of mass in the hinged region. Counterintuitively, the maximum shrinkage does not occur at the patterned surface. Rather, it occurs considerably below the top surface of the polymer. This investigation provides a fundamental understanding of shrinking, self-folding dynamics, and bending angles, and provides design guidelines for origami shapes and structures. PMID:26324954

  14. Calculations of the time-averaged local heat transfer coefficients in circulating fluidized bed

    SciTech Connect

    Dai, T.H.; Qian, R.Z.; Ai, Y.F.

    1999-04-01

    The great potential to burn a wide variety of fuels and the reduced emission of pollutant gases mainly SO{sub x} and NO{sub x} have inspired the investigators to conduct research at a brisk pace all around the world on circulating fluidized bed (CFB) technology. An accurate understanding of heat transfer to bed walls is required for proper design of CFB boilers. To develop an optimum economic design of the boiler, it is also necessary to know how the heat transfer coefficient depends on different design and operating parameters. It is impossible to do the experiments under all operating conditions. Thus, the mathematical model prediction is a valuable method instead. Based on the cluster renewal theory of heat transfer in circulating fluidized beds, a mathematical model for predicting the time-averaged local bed-to-wall heat transfer coefficients is developed. The effects of the axial distribution of the bed density on the time-average local heat transfer coefficients are taken into account via dividing the bed into a series of sections along its height. The assumptions are made about the formation and falling process of clusters on the wall. The model predictions are in an acceptable agreement with the published data.

  15. Integrated bioenergy complex for the production of power, heat and bio-ethanol

    SciTech Connect

    Taviani, M.; Chiaramonti, D.; Tondi, G.; Grassi, G.

    1998-07-01

    In this paper an integrated bioenergy complex for the production of power, heat and bio-ethanol is presented. Ethanol, in fact, has been recognized as a high-quality transportation fuel. The reduction of petroleum consumption, especially for transport, is a strategic goal especially for those countries that already have or will experience an intensive industrial development in the next future. For these motivations, the production of bio-ethanol from Sweet Sorghum (which is now one of the most promising crop for this application in term of productivity, inputs demand, and flexibility) is of great interest in most of countries. The proposed integrated complex produces power, heat and bio-ethanol: the produced power and heat are partly used for bio-ethanol processing and biomass pre-treatment, partly to be sold to the market. This system has important innovations allowing a decentralized energy and ethanol production and creating new local jobs. The small power plant is based upon a steam cycle with an advanced low emission combustor, capable of burning different biomass resources with a modest decrease in the efficiency value. The Bioenergy Complex, suitable to satisfy the needs of a 3,000 inhabitants village, is composed by the following sub-systems: (1) Sweet Sorghum plantation (250 ha); the main products are: dry bagasse (approximately 3,900 Ton/year), grains (1,300 Ton/y) and sugar (1,850 Ton/y); (2) Cane crushing--sugar juice extraction system; (3) Sugar juice fermentation and distillation ethanol production (approx. 835 Ton/y); (4) Biomass pre-treatment components (grinding, drying, briquetting, storage, etc.); and (5) Cogeneration unit--the expansion unit is constituted by a last generation reciprocating steam engine, coupled with a 500 kWe alternator; the heat of the expanded flow is removed in the condenser, with an available thermal power of approximately 2,000 kWt.

  16. Local flow and heat transfer behavior in convex-louver fin arrays

    SciTech Connect

    DeJong, N.C.; Jacobi, A.M.

    1999-02-01

    Highly interrupted fin surfaces are widely used to enhance the air-side thermal performance of compact heat exchangers. Here, local and surface-averaged measurements of convection coefficients and core pressure-drop data are provided for an array of convex-louver fins. For a Reynolds number range from 200 to 5400, these data are complemented with a flow visualization study and contrasted with new measurements from a similar offset-strip geometry. The results clarify the effects of boundary layer restarting, shear-layer unsteadiness, spanwise vortices, and separation, reattachment, and recirculation on heat transfer in the convex-louver geometry.

  17. Localized self-heating in large arrays of 1D nanostructures

    NASA Astrophysics Data System (ADS)

    Monereo, O.; Illera, S.; Varea, A.; Schmidt, M.; Sauerwald, T.; Schütze, A.; Cirera, A.; Prades, J. D.

    2016-02-01

    One dimensional (1D) nanostructures offer a promising path towards highly efficient heating and temperature control in integrated microsystems. The so called self-heating effect can be used to modulate the response of solid state gas sensor devices. In this work, efficient self-heating was found to occur at random networks of nanostructured systems with similar power requirements to highly ordered systems (e.g. individual nanowires, where their thermal efficiency was attributed to the small dimensions of the objects). Infrared thermography and Raman spectroscopy were used to map the temperature profiles of films based on random arrangements of carbon nanofibers during self-heating. Both the techniques demonstrate consistently that heating concentrates in small regions, the here-called ``hot-spots''. On correlating dynamic temperature mapping with electrical measurements, we also observed that these minute hot-spots rule the resistance values observed macroscopically. A physical model of a random network of 1D resistors helped us to explain this observation. The model shows that, for a given random arrangement of 1D nanowires, current spreading through the network ends up defining a set of spots that dominate both the electrical resistance and power dissipation. Such highly localized heating explains the high power savings observed in larger nanostructured systems. This understanding opens a path to design highly efficient self-heating systems, based on random or pseudo-random distributions of 1D nanostructures.One dimensional (1D) nanostructures offer a promising path towards highly efficient heating and temperature control in integrated microsystems. The so called self-heating effect can be used to modulate the response of solid state gas sensor devices. In this work, efficient self-heating was found to occur at random networks of nanostructured systems with similar power requirements to highly ordered systems (e.g. individual nanowires, where their thermal efficiency was attributed to the small dimensions of the objects). Infrared thermography and Raman spectroscopy were used to map the temperature profiles of films based on random arrangements of carbon nanofibers during self-heating. Both the techniques demonstrate consistently that heating concentrates in small regions, the here-called ``hot-spots''. On correlating dynamic temperature mapping with electrical measurements, we also observed that these minute hot-spots rule the resistance values observed macroscopically. A physical model of a random network of 1D resistors helped us to explain this observation. The model shows that, for a given random arrangement of 1D nanowires, current spreading through the network ends up defining a set of spots that dominate both the electrical resistance and power dissipation. Such highly localized heating explains the high power savings observed in larger nanostructured systems. This understanding opens a path to design highly efficient self-heating systems, based on random or pseudo-random distributions of 1D nanostructures. Electronic supplementary information (ESI) available: (i) Experimental procedures and the electrical model used in this work. (ii) MPEG file showing the thermography recording of a heating sequence consisting of five steps: room temperature (RT, 25 °C), 100 °C driven by a heater, RT again, 100 °C driven by self-heating (self-heating nominal temperature, taking the resistance signal as in ref. 34) and RT again. The evolution of the temperature distribution histogram, the maximum, average and minimum temperature recorded and its corresponding CNFs film electrical signal. See DOI: 10.1039/c5nr07158e

  18. Solar powered biohydrogen production requires specific localization of the hydrogenase

    DOE PAGESBeta

    Burroughs, Nigel J.; Boehm, Marko; Eckert, Carrie; Mastroianni, Giulia; Spence, Edward M.; Yu, Jianfeng; Nixon, Peter J.; Appel, Jens; Mullineaux, Conrad W.; Bryan, Samantha J.

    2014-09-04

    Cyanobacteria contain a bidirectional [NiFe] hydrogenase which transiently produces hydrogen upon exposure of anoxic cells to light, potentially acting as a “valve” releasing excess electrons from the electron transport chain. However, its interaction with the photosynthetic electron transport chain remains unclear. By GFP-tagging the HoxF diaphorase subunit we show that the hydrogenase is thylakoid associated, comprising a population dispersed uniformly through the thylakoids and a subpopulation localized to discrete puncta in the distal thylakoid. Thylakoid localisation of both the HoxH and HoxY hydrogenase subunits is confirmed by immunogold electron microscopy. The diaphorase HoxE subunit is essential for recruitment to themore » dispersed thylakoid population, potentially anchoring the hydrogenase to the membrane, but aggregation to puncta occurs through a distinct HoxE-independent mechanism. Membrane association does not require NDH-1. Localization is dynamic on a scale of minutes, with anoxia and high light inducing a significant redistribution between these populations in favour of puncta. Lastly, since HoxE is essential for access to its electron donor, electron supply to the hydrogenase depends on a physiologically controlled localization, potentially offering a new avenue to enhance photosynthetic hydrogen production by exploiting localization/aggregation signals.« less

  19. Solar powered biohydrogen production requires specific localization of the hydrogenase

    SciTech Connect

    Burroughs, Nigel J.; Boehm, Marko; Eckert, Carrie; Mastroianni, Giulia; Spence, Edward M.; Yu, Jianfeng; Nixon, Peter J.; Appel, Jens; Mullineaux, Conrad W.; Bryan, Samantha J.

    2014-09-04

    Cyanobacteria contain a bidirectional [NiFe] hydrogenase which transiently produces hydrogen upon exposure of anoxic cells to light, potentially acting as a “valve” releasing excess electrons from the electron transport chain. However, its interaction with the photosynthetic electron transport chain remains unclear. By GFP-tagging the HoxF diaphorase subunit we show that the hydrogenase is thylakoid associated, comprising a population dispersed uniformly through the thylakoids and a subpopulation localized to discrete puncta in the distal thylakoid. Thylakoid localisation of both the HoxH and HoxY hydrogenase subunits is confirmed by immunogold electron microscopy. The diaphorase HoxE subunit is essential for recruitment to the dispersed thylakoid population, potentially anchoring the hydrogenase to the membrane, but aggregation to puncta occurs through a distinct HoxE-independent mechanism. Membrane association does not require NDH-1. Localization is dynamic on a scale of minutes, with anoxia and high light inducing a significant redistribution between these populations in favour of puncta. Lastly, since HoxE is essential for access to its electron donor, electron supply to the hydrogenase depends on a physiologically controlled localization, potentially offering a new avenue to enhance photosynthetic hydrogen production by exploiting localization/aggregation signals.

  20. The Production of Electricity out of a Heat Bath

    NASA Astrophysics Data System (ADS)

    Graeff, Roderich W.

    2011-12-01

    In order to clarify the dispute between Loschmidt and Boltzmann/Maxwell concerning the existence of a temperature gradient in insulated vertical columns of gas, liquid or solids, macroscopic measurements of the temperature distribution in air, water and solids were performed. A negative temperature gradient, cold at the top and warm at the bottom, is found in insulated vertical tubes, while the outside environment has a reverse gradient. This is explainable by the influence of gravity. It allows the production of electricity out of a heat bath.

  1. 77 FR 39735 - Certain Integrated Circuit Packages Provided With Multiple Heat-Conducting Paths and Products...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-05

    ... COMMISSION Certain Integrated Circuit Packages Provided With Multiple Heat- Conducting Paths and Products... with multiple heat-conducting paths and products containing same by reason of infringement of certain... integrated circuit packages provided with multiple heat-conducting paths and products containing same...

  2. 77 FR 33486 - Certain Integrated Circuit Packages Provided With Multiple Heat-Conducting Paths and Products...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-06

    ... COMMISSION Certain Integrated Circuit Packages Provided With Multiple Heat- Conducting Paths and Products... With Multiple Heat-Conducting Paths and Products Containing Same, DN 2899; the Commission is soliciting... multiple heat-conducting paths and products containing same. The complaint names as respondents...

  3. Characterization and localization of the Huntington disease gene product.

    PubMed

    Hoogeveen, A T; Willemsen, R; Meyer, N; de Rooij, K E; Roos, R A; van Ommen, G J; Galjaard, H

    1993-12-01

    The recent identification of the Huntington's disease (HD) gene, enabled us to synthesize oligopeptides corresponding with the carboxy-terminal end of the predicted HD-gene (IT15) product. Immunobiochemcial studies with polyclonal antibodies directed against this synthetic peptide (position 3114-3141) on lymphoblastoid cells from normal individuals and patients with Huntington disease, revealed the presence of a protein (huntingtin) with a molecular mass of approximately 330 kDa. Immunocytochemical studies showed a cytoplasmic localization of huntingtin in various cell types including neurons. In most of the neuronal cells the protein was also present in the nucleus. No difference in molecular mass or intracellular localization was found between normal and mutant cells. PMID:8111375

  4. Laser production and heating of plasma for MHD application

    NASA Technical Reports Server (NTRS)

    Jalufka, N. W.

    1988-01-01

    Experiments have been made on the production and heating of plasmas by the absorption of laser radiation. These experiments were performed to ascertain the feasibility of using laser-produced or laser-heated plasmas as the input for a magnetohydrodynamic (MHD) generator. Such a system would have a broad application as a laser-to-electricity energy converter for space power transmission. Experiments with a 100-J-pulsed CO2 laser were conducted to investigate the breakdown of argon gas by a high-intensity laser beam, the parameters (electron density and temperature) of the plasma produced, and the formation and propagation of laser-supported detonation (LSD) waves. Experiments were also carried out using a 1-J-pulsed CO2 laser to heat the plasma produced in a shock tube. The shock-tube hydrogen plasma reached electron densities of approximately 10 to the 17th/cu cm and electron temperatures of approximately 1 eV. Absorption of the CO2 laser beam by the plasma was measured, and up to approximately 100 percent absorption was observed. Measurements with a small MHD generator showed that the energy extraction efficiency could be very large with values up to 56 percent being measured.

  5. Laser production and heating of plasma for MHD application

    SciTech Connect

    Jalufka, N.W.

    1988-03-01

    Experiments have been made on the production and heating of plasmas by the absorption of laser radiation. These experiments were performed to ascertain the feasibility of using laser-produced or laser-heated plasmas as the input for a magnetohydrodynamic (MHD) generator. Such a system would have a broad application as a laser-to-electricity energy converter for space power transmission. Experiments with a 100-J-pulsed CO/sub 2/ laser were conducted to investigate the breakdown of argon gas by a high-intensity laser beam, the parameters (electron density and temperature) of the plasma produced, and the formation and propagation of laser-supported detonation (LSD) waves. Experiments were also carried out using a 1-J-pulsed CO/sub 2/ laser to heat the plasma produced in a shock tube. The shock-tube hydrogen plasma reached electron densities of approximately 10 to the 17th/cu cm and electron temperatures of approximately 1 eV. Absorption of the CO/sub 2/ laser beam by the plasma was measured, and up to approximately 100 percent absorption was observed. Measurements with a small MHD generator showed that the energy extraction efficiency could be very large with values up to 56 percent being measured.

  6. Numerical investigation of thermo-mechanical behaviour of composite under local laser heating

    NASA Astrophysics Data System (ADS)

    Li, Xiao; Ni, Xiaowu; Shen, Zhonghua; Li, Zewen

    2015-10-01

    Thermomechanical behaviour of a glass/epoxy composite plate under local laser irradiation is investigated. Physico-chemical transformations and gas transport in a matrix and fibers are describe by Arrhenius and Darcy's law. The changes of material thermal properties are expressed in terms of the volume fractions of fiber, resin, gas and char. At the same time, we take into account the effects of pore pressure and elevating temperature on thermal stresses and strains. It is established that transverse stress, radius stress and interlayer shear caused by local heating and pore pressure are causes of delamination and cracking of composite plates under laser heating. And interlayer shear can lead failure of composite fast.

  7. Local heat-transfer characteristics of glaze-ice accretions on an NACA 0012 airfoil

    NASA Astrophysics Data System (ADS)

    Pais, M. R.; Singh, S. N.; Zou, L.

    1988-12-01

    Laboratory-scale experiments were conducted in the subsonic wind-tunnel facility at the University of Kentucky. Experimental convective local heat-transfer coefficients were obtained for a simulated, full-scale, selected set of 0- and 5-min glaze like ice models on a NACA 0012 airfoil. A steady-state heat-flux method was employed. Local Nusselt numbers for a smooth NACA 0012 airfoil at angles of attack of 0, 2, 4, 6, and 8 deg, and on a 5-min smooth glaze-ice shape on the same airfoil at alpha = 4 deg were also obtained. For the 5-min model, the maximum Nusselt number occurs at the tip of the horn, where it is about 51 percent higher than the rest of the surface, and 25 percent higher for the same location on the 0-min model. A comparison with published results on a NACA 65, 2-016 airfoil is also presented.

  8. Modulation of the axon-reflex response to local heat by reactive oxygen species in subjects with chronic fatigue syndrome.

    PubMed

    Medow, Marvin S; Aggarwal, Arun; Baugham, Ila; Messer, Zachary; Stewart, Julian M

    2013-01-01

    Local cutaneous heating causes vasodilation as an initial first peak, a nadir, and increase to plateau. Reactive oxygen species (ROS) modulate the heat plateau in healthy controls. The initial peak, due to C-fiber nociceptor-mediated axon reflexes, is blunted with local anesthetics and may serve as a surrogate for the cutaneous response to peripheral heat. Chronic fatigue syndrome (CFS) subjects report increased perception of pain. To determine the role of ROS in this neurally mediated response, we evaluated changes in cutaneous blood flow from local heat in nine CFS subjects (16-22 yr) compared with eight healthy controls (18-26 yr). We heated skin to 42C and measured local blood flow as a percentage of maximum cutaneous vascular conductance (%CVC(max)). Although CFS subjects had significantly lower baseline flow [8.75 0.56 vs. 12.27 1.07 (%CVC(max), CFS vs. control)], there were no differences between groups to local heat. We then remeasured this with apocynin to inhibit NADPH oxidase, allopurinol to inhibit xanthine oxidase, tempol to inhibit superoxide, and ebselen to reduce H(2)O(2). Apocynin significantly increased baseline blood flow (before heat, 14.91 2.21 vs. 8.75 1.66) and the first heat peak (69.33 3.36 vs. 59.75 2.75). Allopurinol and ebselen only enhanced the first heat peaks (71.55 2.48 vs. 61.72 2.01 and 76.55 5.21 vs. 58.56 3.66, respectively). Tempol had no effect on local heating. None of these agents changed the response to local heat in control subjects. Thus the response to heat may be altered by local levels of ROS, particularly H(2)O(2) in CFS subjects, and may be related to their hyperesthesia/hyperalgesia. PMID:23139367

  9. Modulation of the axon-reflex response to local heat by reactive oxygen species in subjects with chronic fatigue syndrome

    PubMed Central

    Aggarwal, Arun; Baugham, Ila; Messer, Zachary; Stewart, Julian M.

    2013-01-01

    Local cutaneous heating causes vasodilation as an initial first peak, a nadir, and increase to plateau. Reactive oxygen species (ROS) modulate the heat plateau in healthy controls. The initial peak, due to C-fiber nociceptor-mediated axon reflexes, is blunted with local anesthetics and may serve as a surrogate for the cutaneous response to peripheral heat. Chronic fatigue syndrome (CFS) subjects report increased perception of pain. To determine the role of ROS in this neurally mediated response, we evaluated changes in cutaneous blood flow from local heat in nine CFS subjects (1622 yr) compared with eight healthy controls (1826 yr). We heated skin to 42C and measured local blood flow as a percentage of maximum cutaneous vascular conductance (%CVCmax). Although CFS subjects had significantly lower baseline flow [8.75 0.56 vs. 12.27 1.07 (%CVCmax, CFS vs. control)], there were no differences between groups to local heat. We then remeasured this with apocynin to inhibit NADPH oxidase, allopurinol to inhibit xanthine oxidase, tempol to inhibit superoxide, and ebselen to reduce H2O2. Apocynin significantly increased baseline blood flow (before heat, 14.91 2.21 vs. 8.75 1.66) and the first heat peak (69.33 3.36 vs. 59.75 2.75). Allopurinol and ebselen only enhanced the first heat peaks (71.55 2.48 vs. 61.72 2.01 and 76.55 5.21 vs. 58.56 3.66, respectively). Tempol had no effect on local heating. None of these agents changed the response to local heat in control subjects. Thus the response to heat may be altered by local levels of ROS, particularly H2O2 in CFS subjects, and may be related to their hyperesthesia/hyperalgesia. PMID:23139367

  10. Heat shock modulates the subcellular localization, stability, and activity of HIPK2.

    PubMed

    Upadhyay, Mamta; Bhadauriya, Pratibha; Ganesh, Subramaniam

    2016-04-15

    The homeodomain-interacting protein kinase-2 (HIPK2) is a highly conserved serine/threonine kinase and is involved in transcriptional regulation. HIPK2 is a highly unstable protein, and is kept at a low level under normal physiological conditions. However, exposure of cells to physiological stress - such as hypoxia, oxidative stress, or UV damage - is known to stabilize HIPK2, leading to the HIPK2-dependent activation of p53 and the cell death pathway. Therefore HIPK2 is also known as a stress kinase and as a stress-activated pro-apoptotic factor. We demonstrate here that exposure of cells to heat shock results in the stabilization of HIPK2 and the stabilization is mediated via K63-linked ubiquitination. Intriguingly, a sub-lethal heat shock (42 °C, 1 h) results in the cytoplasmic localization of HIPK2, while a lethal heat shock (45 °C, 1 h) results in its nuclear localization. Cells exposed to the lethal heat shock showed significantly higher levels of the p53 activity than those exposed to the sub-lethal thermal stress, suggesting that both the level and the nuclear localization are essential for the pro-apoptotic activity of HIPK2 and that the lethal heat shock could retain the HIPK2 in the nucleus to promote the cell death. Taken together our study underscores the importance of HIPK2 in stress mediated cell death, and that the HIPK2 is a generic stress kinase that gets activated by diverse set of physiological stressors. PMID:26972256

  11. Numerical calculation of local convective heat transfer coefficients over air-cooled vane surfaces

    NASA Astrophysics Data System (ADS)

    Ling, J.; Jin, D.

    1982-12-01

    A numerical model for iterative, simultaneous solution of two-dimensional compressible boundary layer equations and steady-state equations of heat conduction is presented, together with a FORTRAN program for calculating the local convective heat transfer coefficients over an air-cooled, vaned surface. The approximate integral method is employed for the boundary layer equation, while the finite element method is used to derive the temperature field of the blades. The program input comprises the blade geometry, the pressure or velocity distribution of the gas flow outside the boundary layer, the entrance flow characteristics, the internal cooling conditions, the nodal numbers, and the coordinates of the elements. The program yields the heat transfer coefficients and the temperature distribution on the surface and inside the blades. Good agreement was found with experimental results

  12. In situ imaging highlights local structural changes during heating: the case of meat.

    PubMed

    Bouhrara, Mustapha; Clerjon, Sylvie; Damez, Jean-Louis; Kondjoyan, Alain; Bonny, Jean-Marie

    2012-05-01

    Understanding and monitoring deformation and water content changes in meat during cooking is of prime importance. We show the possibilities offered by nuclear magnetic resonance imaging (MRI) for the in situ dynamic measurement of deformation fields and water content mapping during beef heating from 20 to 75 C. MRIs were acquired during heating, and image registration was used to calculate the deformation field. The temperature distribution in the sample was simulated numerically to link structural modifications and water transfer to temperature values. During heating, proton density decreases because of a magnetic susceptibility drop with temperature and water expulsion due to muscle contraction. A positive relationship was found between local cumulative deformation and water content. This new approach makes it possible to identify the deformation field and water transfer simultaneously and to trace thermal history to build heuristic models linking these parameters. PMID:22462532

  13. Local stress and heat flux in atomistic systems involving three-body forces.

    PubMed

    Chen, Youping

    2006-02-01

    Local densities of fundamental physical quantities, including stress and heat flux fields, are formulated for atomistic systems involving three-body forces. The obtained formulas are calculable within an atomistic simulation, in consistent with the conservation equations of thermodynamics of continuum, and can be applied to systems with general two- and three-body interaction forces. It is hoped that this work may correct some misuse of inappropriate formulas of stress and heat flux in the literature, may clarify the definition of site energy of many-body potentials, and may serve as an analytical link between an atomistic model and a continuum theory. Physical meanings of the obtained formulas, their relation with virial theorem and heat theorem, and the applicability are discussed. PMID:16468857

  14. Implantable polymer/metal thin film structures for the localized treatment of cancer by Joule heating

    NASA Astrophysics Data System (ADS)

    Kan-Dapaah, Kwabena; Rahbar, Nima; Theriault, Christian; Soboyejo, Wole

    2015-04-01

    This paper presents an implantable polymer/metal alloy thin film structure for localized post-operative treatment of breast cancer. A combination of experiments and models is used to study the temperature changes due to Joule heating by patterned metallic thin films embedded in poly-dimethylsiloxane. The heat conduction within the device and the surrounding normal/cancerous breast tissue is modeled with three-dimensional finite element method (FEM). The FEM simulations are used to explore the potential effects of device geometry and Joule heating on the temperature distribution and lesion (thermal dose). The FEM model is validated using a gel model that mimics biological media. The predictions are also compared to prior results from in vitro studies and relevant in vivo studies in the literature. The implications of the results are discussed for the potential application of polymer/metal thin film structures in hyperthermic treatment of cancer.

  15. Residual Stress Measurements with Laser Speckle Correlation Interferometry and Local Heat Treating

    SciTech Connect

    Pechersky, M.J.; Miller, R.F.; Vikram, C.S.

    1994-01-06

    A new experimental technique has been devised to measure residual stresses in ductile materials with a combination of laser speckle pattern interferometry and spot heating. The speckle pattern interferometer measures in-plane deformations while the heating provides for very localized stress relief. The residual stresses are determined by the amount of strain that is measured subsequent to the heating and cool-down of the region being interrogated. A simple lumped parameter model is presented to provide a description of the method. This description is followed by presentations of the results of finite element analyses and experimental results with uniaxial test specimens. Excellent agreement between the experiments and the computer analyses were obtained.

  16. On the locality of parallel transport of heat carrying electrons in the SOL

    NASA Astrophysics Data System (ADS)

    Chankin, A. V.; Coster, D. P.

    2015-08-01

    A continuum Vlasov-Fokker-Planck code KIPP is used to assess the degree of locality of parallel transport of heat carrying electrons (HCE) in collisional SOLs. It is shown that for typical SOL collisionalities, the HCE are marginally collisionless which puts into question successful parameterization of kinetic code results of transport parameters such as parallel heat flux and ion-electron thermoforce in the present 2D fluid codes. A kinetic solution for the case of 90% recycling at the target and factor 10Te drop along the field line is also presented, showing the degree of heat flux 'limiting' upstream and 'enhancement' downstream, compared to predictions of the Braginskii's (or Spitzer-Hrm's) formulas. Possible causes of these features are discussed.

  17. Thermal parameters determination of battery cells by local heat flux measurements

    NASA Astrophysics Data System (ADS)

    Murashko, K. A.; Mityakov, A. V.; Pyrhnen, J.; Mityakov, V. Y.; Sapozhnikov, S. S.

    2014-12-01

    A new approach to define of the thermal parameters, such as heat capacity and through-plane thermal conductivity, of pouch-type cells is introduced. Application of local heat flux measurement with a gradient heat flux sensor (GHFS) allows determination of the cell thermal parameters in different surface points of the cell. The suggested method is not cell destructive as it does not require deep discharge of the cell or application of any charge/discharge cycles during the measurements of the thermal parameters of the cell. The complete procedure is demonstrated on a high-power lithium-ion (Li-ion) pouch cell, and it is verified on a sample with well-known thermal parameters. A comparison of the experimental results with conventional thermal characterization methods shows an acceptably low error. The dependence of the cell thermal parameters on the state of charge (SoC) and measurement points on the surface was studied by the proposed measurement approach.

  18. 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.

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

    NASA Astrophysics Data System (ADS)

    Timmerman, B. H.; Bryanston-Cross, P. J.

    2007-10-01

    Two novel optical techniques are presented for non-intrusive, spatially resolved study of combustion, both based on passive Optical Emission Tomography (OET). Firstly, 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 presented 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, a method is presented for study of the production of NOx through chemiluminescence from tri-methyl-borate (TMB). In combustion, the tri-methyl-borate produces green luminescence in locations where NOx would be produced. Combining the green luminescence visualisation with UV 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.

  20. Welding of Semiconductor Nanowires by Coupling Laser-Induced Peening and Localized Heating

    PubMed Central

    Rickey, Kelly M.; Nian, Qiong; Zhang, Genqiang; Chen, Liangliang; Suslov, Sergey; Bhat, S. Venkataprasad; Wu, Yue; Cheng, Gary J.; Ruan, Xiulin

    2015-01-01

    We demonstrate that laser peening coupled with sintering of CdTe nanowire films substantially enhances film quality and charge transfer while largely maintaining basic particle morphology. During the laser peening phase, a shockwave is used to compress the film. Laser sintering comprises the second step, where a nanosecond pulse laser beam welds the nanowires. Microstructure, morphology, material content, and electrical conductivities of the films are characterized before and after treatment. The morphology results show that laser peening can decrease porosity and bring nanowires into contact, and pulsed laser heating fuses those contacts. Multiphysics simulations coupling electromagnetic and heat transfer modules demonstrate that during pulsed laser heating, local EM field enhancement is generated specifically around the contact areas between two semiconductor nanowires, indicating localized heating. The characterization results indicate that solely laser peening or sintering can only moderately improve the thin film quality; however, when coupled together as laser peen sintering (LPS), the electrical conductivity enhancement is dramatic. LPS can decrease resistivity up to a factor of ~10,000, resulting in values on the order of ~105 Ω-cm in some cases, which is comparable to CdTe thin films. Our work demonstrates that LPS is an effective processing method to obtain high-quality semiconductor nanocrystal films. PMID:26527570

  1. Welding of Semiconductor Nanowires by Coupling Laser-Induced Peening and Localized Heating.

    PubMed

    Rickey, Kelly M; Nian, Qiong; Zhang, Genqiang; Chen, Liangliang; Suslov, Sergey; Bhat, S Venkataprasad; Wu, Yue; Cheng, Gary J; Ruan, Xiulin

    2015-01-01

    We demonstrate that laser peening coupled with sintering of CdTe nanowire films substantially enhances film quality and charge transfer while largely maintaining basic particle morphology. During the laser peening phase, a shockwave is used to compress the film. Laser sintering comprises the second step, where a nanosecond pulse laser beam welds the nanowires. Microstructure, morphology, material content, and electrical conductivities of the films are characterized before and after treatment. The morphology results show that laser peening can decrease porosity and bring nanowires into contact, and pulsed laser heating fuses those contacts. Multiphysics simulations coupling electromagnetic and heat transfer modules demonstrate that during pulsed laser heating, local EM field enhancement is generated specifically around the contact areas between two semiconductor nanowires, indicating localized heating. The characterization results indicate that solely laser peening or sintering can only moderately improve the thin film quality; however, when coupled together as laser peen sintering (LPS), the electrical conductivity enhancement is dramatic. LPS can decrease resistivity up to a factor of ~10,000, resulting in values on the order of ~10(5) Ω-cm in some cases, which is comparable to CdTe thin films. Our work demonstrates that LPS is an effective processing method to obtain high-quality semiconductor nanocrystal films. PMID:26527570

  2. Welding of Semiconductor Nanowires by Coupling Laser-Induced Peening and Localized Heating

    NASA Astrophysics Data System (ADS)

    Rickey, Kelly M.; Nian, Qiong; Zhang, Genqiang; Chen, Liangliang; Suslov, Sergey; Bhat, S. Venkataprasad; Wu, Yue; Cheng, Gary J.; Ruan, Xiulin

    2015-11-01

    We demonstrate that laser peening coupled with sintering of CdTe nanowire films substantially enhances film quality and charge transfer while largely maintaining basic particle morphology. During the laser peening phase, a shockwave is used to compress the film. Laser sintering comprises the second step, where a nanosecond pulse laser beam welds the nanowires. Microstructure, morphology, material content, and electrical conductivities of the films are characterized before and after treatment. The morphology results show that laser peening can decrease porosity and bring nanowires into contact, and pulsed laser heating fuses those contacts. Multiphysics simulations coupling electromagnetic and heat transfer modules demonstrate that during pulsed laser heating, local EM field enhancement is generated specifically around the contact areas between two semiconductor nanowires, indicating localized heating. The characterization results indicate that solely laser peening or sintering can only moderately improve the thin film quality; however, when coupled together as laser peen sintering (LPS), the electrical conductivity enhancement is dramatic. LPS can decrease resistivity up to a factor of ~10,000, resulting in values on the order of ~105 Ω-cm in some cases, which is comparable to CdTe thin films. Our work demonstrates that LPS is an effective processing method to obtain high-quality semiconductor nanocrystal films.

  3. Local Control of Aldosterone Production and Primary Aldosteronism.

    PubMed

    Lalli, Enzo; Barhanin, Jacques; Zennaro, Maria-Christina; Warth, Richard

    2016-03-01

    Primary aldosteronism (PA) is caused by excessive production of aldosterone by the adrenal cortex and is determined by a benign aldosterone-producing adenoma (APA) in a significant proportion of cases. Local mechanisms, as opposed to circulatory ones, that control aldosterone production in the adrenal cortex are particularly relevant in the physiopathological setting and in the pathogenesis of PA. A breakthrough in our understanding of the pathogenetic mechanisms in APA has been the identification of somatic mutations in genes controlling membrane potential and intracellular calcium concentrations. However, recent data show that the processes of nodule formation and aldosterone hypersecretion can be dissociated in pathological adrenals and suggest a model envisaging different molecular events for the pathogenesis of APA. PMID:26803728

  4. A non-local model of fractional heat conduction in rigid bodies

    NASA Astrophysics Data System (ADS)

    Borino, G.; di Paola, M.; Zingales, M.

    2011-03-01

    In recent years several applications of fractional differential calculus have been proposed in physics, chemistry as well as in engineering fields. Fractional order integrals and derivatives extend the well-known definitions of integer-order primitives and derivatives of the ordinary differential calculus to real-order operators. Engineering applications of fractional operators spread from viscoelastic models, stochastic dynamics as well as with thermoelasticity. In this latter field one of the main actractives of fractional operators is their capability to interpolate between the heat flux and its time-rate of change, that is related to the well-known second sound effect. In other recent studies a fractional, non-local thermoelastic model has been proposed as a particular case of the non-local, integral, thermoelasticity introduced at the mid of the seventies. In this study the autors aim to introduce a different non-local model of extended irreverible thermodynamics to account for second sound effect. Long-range heat flux is defined and it involves the integral part of the spatial Marchaud fractional derivatives of the temperature field whereas the second-sound effect is accounted for introducing time-derivative of the heat flux in the transport equation. It is shown that the proposed model does not suffer of the pathological problems of non-homogenoeus boundary conditions. Moreover the proposed model coalesces with the Povstenko fractional models in unbounded domains.

  5. Local multiquadric RBF meshless scheme for radiative heat transfer in strongly inhomogeneous media

    NASA Astrophysics Data System (ADS)

    Sun, Jie; Luo, Kang; Yi, Hong-Liang; Tan, He-Ping

    2015-10-01

    A local radial basis function meshless method (LRBFM) is developed to solve radiative heat transfer in participating media, in which multiquadric (MQ) radial basis functions (RBF) augmented with polynomial basis are employed to construct the trial functions, and the radiative transfer equation (RTE) is discretized directly at nodes by collocation method. The LRBFM belongs to a class of truly meshless methods which do not need any mesh, and can be implemented on a set of uniform or irregular nodes without nodes' connectivity. To improve numerical stability of LRBFM for the solution to radiative heat transfer in strongly inhomogeneous media, an upwind support domain scheme is introduced. The upwind scheme is implemented by moving the support domain of local radial basis function interpolation approximation to the opposite direction of each streamline, which can fully capture the information from upstream and improve the accuracy and stability of LRBFM. Performances of the LRBFM and upwind LRBFM (LRBFM_U) are compared with analytical solutions and other numerical results reported earlier in the literatures via a variety of problems in 1-D and 2-D geometries with strongly inhomogeneous media. It is demonstrated that the local radial basis function meshless method with upwind support domain scheme (LRBFM_U) provides high accuracy and great stability to solve radiative heat transfer in strongly inhomogeneous media.

  6. Model simulation of a localized high intensity heat source interacting with cooled metal plates

    NASA Astrophysics Data System (ADS)

    Cranfill, F. M.

    The basic, generic problem of a localized high intensity heat source directed against one surface of a plate of finite thickness was investigated using the finite element program ANSYS. After reviewing similar work in nuclear fuel and laser machining, ANSYS was verified against a known solution. ANSYS was used to create a model that yields minimum heat transfer coefficients needed to prevent the initiation of melting in thin aluminum, titanium, and stainless steel (AISI 304) plates. These heat transfer coefficients were converted into minimum local Nusselt numbers and graphed against local Nusselt number correlations for constant temperature flat plates in forced and free convection regimes. A detailed listing of both laminar and turbulent correlations is presented along with references. The suitability of liquid sodium, air, and water (under high pressure) as coolants for a source intensity of 2.0 x 10 to the 7th power w/sq m was examined. For free convection, only liquid sodium cooling a titanium plate is feasible, For forced convection, liquid sodium is feasible in laminar flow fo r all three plates with velocities ranging from 0.28 m/s to 1.09 m/s. Water is feasible for aluminum and titanium in turbulent flow at velocities of approximately 4 m/s.

  7. Numerical assessment of local forcing on the heat transfer in a turbulent channel flow

    NASA Astrophysics Data System (ADS)

    Araya, Guillermo; Leonardi, Stefano; Castillo, Luciano

    2008-08-01

    The influence of local forcing on an incompressible turbulent channel flow is numerically investigated. The extensive information provided by the direct numerical simulations enables us to have a better understanding of the physical mechanism responsible for local heat transfer enhancement. Time-periodic blowing/suction is applied by means of thin spanwise slots located at the lower and upper walls. The molecular Prandtl number is 0.71 and the Reynolds number based on the wall friction velocity and the channel half-height, Re?, is 394 for the unforced case. The normal perturbing velocity is varied sinusoidally in time at several perturbing frequencies between 0.16local increase in the skin friction in the region 0.1heat flux, and Stanton number enhancement downstream from the local forcing source. On the other hand, local maxima of Reynolds shear stresses, wall-normal turbulent heat fluxes, and the incoherent component of streamwise vorticity fluctuations exhibited analogous behavior along the streamwise direction.

  8. Characterization of Heat Melt Compactor (HMC) Product Water

    NASA Technical Reports Server (NTRS)

    Harris, Linden; Wignarajah, Kanapathipi; Alba, Richard Gilbert; Pace, Gregory S.; Fisher, John W.

    2013-01-01

    The Heat Melt Compactor (HMC) is designed to sterilize and process wastes produced during space missions. Benefits of the HMC include reduction of biohazards to the crew, reduction in volume of wastes that would otherwise require storage, production of radiation shielding tiles, and recovery of water and other resources. Water reuse is critical onboard spacecrafts; it reduces the need for resupply missions and saves valuable storage space. The main sources of water in HMC batches are food, beverages, shampoo, disinfecting wipes, toothpaste, and diapers. Water reclaimed by the HMC was analyzed for concentrations of Na+, NH4+, K+, Mg2+, Ca2+, Cl-­-, NO2-­-, Br-­-, NO3-­-, PO43-­-, SO42-­-, total organic carbon (TOC), total inorganic carbon (TIC), % total solids, and pH. The data are discussed in relation to the current water input characteristics established for the International Space Station Water Processor Assembly system. Batches with higher than average amounts of food produced HMC product water with higher sulfate content, and batches with higher proportions of disinfectant wipes and food yielded HMC product water with higher ammonium concentration. We also compared theoretical chemical composition of HMC product water based on food labels and literature values to experimental results.

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

    SciTech Connect

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

    2006-03-15

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

  10. Natural convection in horizontal porous layers with localized heating from below

    SciTech Connect

    Prasad, V. ); Kulacki, F.A. )

    1987-08-01

    Convective flow of fluid through saturated porous media heated from below is of considerable interest, and has been extensively studied. Most of these studies are concerned with either infinite horizontal porous layers or rectangular (or cylindrical) porous cavities with adiabatic vertical walls. A related problem of practical importance occurs when only a portion of the bottom surface is heated and the rest of it is either adiabatic or isothermally cooled. This situation is encountered in several geothermal areas which consists of troughs of volcanic debris contained by walls of nonfragmented ignimbrite. Thus, the model region considered is a locally heated long trough of isotropic porous medium confined by impermeable and insulating surroundings. Also, the recent motivation to study this problem has come from the efforts to identify a geologic repository for nuclear waste disposal. The purpose of the present work is to consider the effects of aspect ratio and Rayleigh number on free convection heat transfer from an isothermal heat source centrally located on the bottom surface of a horizontal porous cavity.

  11. Local Heating of Discrete Droplets Using Magnetic Porous Silicon-Based Photonic Crystals

    PubMed Central

    Park, Ji-Ho; Derfus, Austin M.; Segal, Ester; Vecchio, Kenneth S.; Bhatia, Sangeeta N.; Sailor, Michael J.

    2012-01-01

    This paper describes a method for local heating of discrete micro-liter scale liquid droplets. The droplets are covered with magnetic porous Si microparticles, and heating is achieved by application of an external alternating electromagnetic field. The magnetic porous Si microparticles consist of two layers: the top layer contains a photonic code and it is hydrophobic, with surface-grafted dodecyl moieties. The bottom layer consists of a hydrophilic Si oxide host layer that is infused with Fe3O4 nanoparticles. The amphiphilic microparticles spontaneously align at the interface of a water droplet immersed in mineral oil, allowing manipulation of the droplets by application of a magnetic field. Application of an oscillating magnetic field (338 kHz, 18A RMS current in a coil surrounding the experiment) generates heat in the superparamagnetic particles that can raise the temperature of the enclosed water droplet to >80 °C within 5 min. A simple microfluidics application is demonstrated: combining complementary DNA strands contained in separate droplets and then thermally inducing dehybridization of the conjugate. The complementary oligonucleotides were conjugated with the cyanine dye fluorophores Cy3 and Cy5 to quantify the melting/re-binding reaction by fluorescence resonance energy transfer (FRET). The magnetic porous Si microparticles were prepared as photonic crystals, containing spectral codes that allowed the identification of the droplets by reflectivity spectroscopy. The technique demonstrates the feasibility of tagging, manipulating, and heating small volumes of liquids without the use of conventional microfluidic channel and heating systems. PMID:16771508

  12. Natural products locally modulators of the cellular response: therapeutic perspectives in skin burns.

    PubMed

    Mogo?anu, G D; Popescu, Florina Carmen; Busuioc, Cristina Jana; Prv?nescu, H; Lasc?r, I

    2012-01-01

    Local cellular response plays a major role in restoring skin integrity, in burns with infectious complications, chronic fibrous sequelae, etc. For the study of wound-healing process, different experimental models of skin burn were developed. Mice, rats, rabbits and guinea pigs are the most used laboratory animals, kept under standard conditions of light, temperature, food and water (ad libitum). Commonly, by intramuscular injection, general anesthesia was induced with ketamine hydrochloride. Most times, skin burns were inflicted on the dorsal region of animals. Metal devices with different shapes and weights, heated in water at various temperatures were applied locally, for few seconds. The paper reports on 65 natural medicinal products recommended for the external and internal treatment of skin damages (first- or second-degree burns, various wounds, ulcerations). Some of them are traditionally used in the Romanian ethnopharmacology, supporting the wound-healing process mainly because of their epithelizing, astringent, emollient, demulcent, anti-inflammatory, antimicrobial, immunomodulatory and antioxidant properties. PMID:22732793

  13. The global potential of local peri-urban food production

    NASA Astrophysics Data System (ADS)

    Kriewald, Steffen; Garcia Cantu Ros, Anselmo; Sterzel, Till; Kropp, Jürgen P.

    2013-04-01

    One big challenge for the rest of the 21st century will be the massive urbanisation. It is expected that more than 7 out of 10 persons will live in a city by the year 2050. Crucial developments towards a sustainable future will therefore take place in cities. One important approach for a sustainable city development is to re-localize food production and to close urban nutrient cycles through better waste management. The re-location of food production avoids CO2 emissions from transportation of food to cities and can also generate income for inhabitants. Cities are by definition locations where fertility accumulates. As cities are often built along rivers, their soils are often fertile. Furthermore, labour force and the possibility of producing fertilizer from human fecal matter within the city promises sustainable nutrients cycles. Although urban and peri-urban agriculture can be found in many cities worldwide and already have a substantial contribution to food supply, it has not jet been comprehensibly structured by research. We combine several worldwide data sets to determine the supply of cities with regional food production, where regional is defined as a production that occurs very close to the consumption within the peri-urban area. Therefore, urban areas are not defined by administrative boundaries but by connected built-up urban areas, and peri-urban area by the surrounding area with the same size multiplied with a scaling parameter. Both together accumulate to an urban-bio-region (UBR). With regard to national food consumption, a linear program achieves the best possible yield on agricultural areas and allows the computation of the fraction of population, which can be nourished. Additionally, several climate scenarios and different dietary patterns were considered. To close the gap between single case studies and to provide a quantitative overview of the global potential of peri-urban food production we used high resolution land-use data Global Land Cover Service (GlobCover), the global agricultural yield dataset from the Global Agro-ecological Zones (GAEZ) and census population data from the Global Rural-Urban Mapping Project, Version 1 (GRUMPv1) to estimate the potential of 2838 UBR worldwide. With regard to making use of local circumstances, the results of potential worldwide peri-urban agriculture emphasize the ongoing investigation of sustainable transitions of the socio-ecologic system. Identifying areas for increased food production while maintaining the natural resources and the urban needs will be a major task for cities in future.

  14. Investigations about the quantitative changes of carbon dioxide production in humans. Report 2: Carbon dioxide production during fever and its relationship with heat production

    NASA Technical Reports Server (NTRS)

    Liebermeister, C.

    1978-01-01

    Investigations are cited and explained for carbon dioxide production during fever and its relationship with heat production. The general topics of discussion are: (1) carbon dioxide production for alternating fever attacks; (2) heat balance during the perspiration phase; (3) heat balance during the chill phase; (4) the theory of fever; and (5) chill phase for other fever attacks.

  15. Local Heat Transfer and CHF for Subcooled Flow Boiling - Annual Report 1996

    SciTech Connect

    Dr. Ronald D. Boyd

    2000-07-01

    For the past decade, efforts have been growing in the development of high heat flux (HHF) components for many applications, including fusion and fission reactor components, advanced electronic components, synchrotrons and optical components, and other advanced HHF engineering applications. From a thermal prospective, work in the fusion reactor development arena has been underway in a number of areas including: (1) Plasma thermal, and electro-magnetics, and particle transport, (2) Fusion material, rheology, development, and expansion and selection; (3) High heat flux removal; and (4) Energy production and efficiency.

  16. The Immunology of a Healing Response in Cutaneous Leishmaniasis Treated with Localized Heat or Systemic Antimonial Therapy

    PubMed Central

    Lakhal-Naouar, Ines; Slike, Bonnie M.; Aronson, Naomi E.; Marovich, Mary A.

    2015-01-01

    Background The effectiveness of systemic antimonial (sodium stibogluconate, Pentostam, SSG) treatment versus local heat therapy (Thermomed) for cutaneous leishmaniasis was studied previously and showed similar healing rates. We hypothesized that different curative immune responses might develop with systemic and local treatment modalities. Methods We studied the peripheral blood immune cells in a cohort of 54 cutaneous Leishmania major subjects treated with SSG or TM. Multiparameter flow cytometry, lymphoproliferative assays and cytokine production were analyzed in order to investigate the differences in the immune responses of subjects before, on and after treatment. Results Healing cutaneous leishmaniasis lead to a significant decline in circulating T cells and NKT-like cells, accompanied by an expansion in NK cells, regardless of treatment modality. Functional changes involved decreased antigen specific CD4+ T cell proliferation (hyporesponsiveness) seen with CD8+ T cell depletion. Moreover, the healing (or healed) state was characterized by fewer circulating regulatory T cells, reduced IFN-γ production and an overall contraction in polyfunctional CD4+ T cells. Conclusion Healing from cutaneous Leishmaniasis is a dynamic process that alters circulating lymphocyte populations and subsets of T, NK and NKT-like cells. Immunology of healing, through local or systemic treatments, culminated in similar changes in frequency, quality, and antigen specific responsiveness with immunomodulation possibly via a CD8+ T cell dependent mechanism. Understanding the evolving immunologic changes during healing of human leishmaniasis informs protective immune mechanisms. PMID:26485398

  17. Singlet oxygen production in Chlamydomonas reinhardtii under heat stress.

    PubMed

    Prasad, Ankush; Ferretti, Ursula; Sedlářová, Michaela; Pospíšil, Pavel

    2016-01-01

    In the current study, singlet oxygen formation by lipid peroxidation induced by heat stress (40 °C) was studied in vivo in unicellular green alga Chlamydomonas reinhardtii. Primary and secondary oxidation products of lipid peroxidation, hydroperoxide and malondialdehyde, were generated under heat stress as detected using swallow-tailed perylene derivative fluorescence monitored by confocal laser scanning microscopy and high performance liquid chromatography, respectively. Lipid peroxidation was initiated by enzymatic reaction as inhibition of lipoxygenase by catechol and caffeic acid prevented hydroperoxide formation. Ultra-weak photon emission showed formation of electronically excited species such as triplet excited carbonyl, which, upon transfer of excitation energy, leads to the formation of either singlet excited chlorophyll or singlet oxygen. Alternatively, singlet oxygen is formed by direct decomposition of hydroperoxide via Russell mechanisms. Formation of singlet oxygen was evidenced by the nitroxyl radical 2,2,6,6-tetramethylpiperidine-1-oxyl detected by electron paramagnetic resonance spin-trapping spectroscopy and the imaging of green fluorescence of singlet oxygen sensor green detected by confocal laser scanning microscopy. Suppression of singlet oxygen formation by lipoxygenase inhibitors indicates that singlet oxygen may be formed via enzymatic lipid peroxidation initiated by lipoxygenase. PMID:26831215

  18. Singlet oxygen production in Chlamydomonas reinhardtii under heat stress

    PubMed Central

    Prasad, Ankush; Ferretti, Ursula; Sedlářová, Michaela; Pospíšil, Pavel

    2016-01-01

    In the current study, singlet oxygen formation by lipid peroxidation induced by heat stress (40 °C) was studied in vivo in unicellular green alga Chlamydomonas reinhardtii. Primary and secondary oxidation products of lipid peroxidation, hydroperoxide and malondialdehyde, were generated under heat stress as detected using swallow-tailed perylene derivative fluorescence monitored by confocal laser scanning microscopy and high performance liquid chromatography, respectively. Lipid peroxidation was initiated by enzymatic reaction as inhibition of lipoxygenase by catechol and caffeic acid prevented hydroperoxide formation. Ultra-weak photon emission showed formation of electronically excited species such as triplet excited carbonyl, which, upon transfer of excitation energy, leads to the formation of either singlet excited chlorophyll or singlet oxygen. Alternatively, singlet oxygen is formed by direct decomposition of hydroperoxide via Russell mechanisms. Formation of singlet oxygen was evidenced by the nitroxyl radical 2,2,6,6-tetramethylpiperidine-1-oxyl detected by electron paramagnetic resonance spin-trapping spectroscopy and the imaging of green fluorescence of singlet oxygen sensor green detected by confocal laser scanning microscopy. Suppression of singlet oxygen formation by lipoxygenase inhibitors indicates that singlet oxygen may be formed via enzymatic lipid peroxidation initiated by lipoxygenase. PMID:26831215

  19. The Chemistry of Self-Heating Food Products: An Activity for Classroom Engagement

    ERIC Educational Resources Information Center

    Oliver-Hoyo, Maria T.; Pinto, Gabriel; Llorens-Molina, Juan Antonio

    2009-01-01

    Two commercial self-heating food products have been used to apply chemical concepts such as stoichiometry, enthalpies of reactions and solutions, and heat transfer in a classroom activity. These products are the self-heating beverages sold in Europe and the Meals, Ready to Eat or MREs used primarily by the military in the United States. The main…

  20. The Chemistry of Self-Heating Food Products: An Activity for Classroom Engagement

    ERIC Educational Resources Information Center

    Oliver-Hoyo, Maria T.; Pinto, Gabriel; Llorens-Molina, Juan Antonio

    2009-01-01

    Two commercial self-heating food products have been used to apply chemical concepts such as stoichiometry, enthalpies of reactions and solutions, and heat transfer in a classroom activity. These products are the self-heating beverages sold in Europe and the Meals, Ready to Eat or MREs used primarily by the military in the United States. The main

  1. A Fresnel collector process heat experiment at Capitol Concrete Products

    NASA Technical Reports Server (NTRS)

    Hauger, J. S.

    1981-01-01

    An experiment is planned, conducted and evaluated to determine the feasibility of using a Power Kinetics' Fresnel concentrator to provide process heat in an industrial environment. The plant provides process steam at 50 to 60 psig to two autoclaves for curing masonry blocks. When steam is not required, the plant preheats hot water for later use. A second system is installed at the Jet Propulsion Laboratory parabolic dish test site for hardware validation and experiment control. Experiment design allows for the extrapolation of results to varying demands for steam and hot water, and includes a consideration of some socio-technical factors such as the impact on production scheduling of diurnal variations in energy availability.

  2. Detailed measurements of local heat transfer coefficient and adiabatic wall temperature beneath an array of impinging jets

    SciTech Connect

    Van Treuren, K.W.; Wang, Z.; Ireland, P.T.; Jones, T.V. . Dept. of Engineering Science)

    1994-07-01

    A transient method of measuring the local heat transfer under an array of impinging jets has been developed. The use of a temperature-sensitive coating consisting of three encapsulated thermochromic liquid crystal materials has allowed the calculation of both the local adiabatic wall temperature and the local heat transfer coefficient over the complete surface of the target plate. The influence of the temperature of the plate through which the impingment gas flows on the target plate heat transfer has been quantified. Results are presented for a single in-line array configuration over a range of jet Reynolds numbers.

  3. Toxicological evaluation of some Malaysian locally processed raw food products.

    PubMed

    Sharif, R; Ghazali, A R; Rajab, N F; Haron, H; Osman, F

    2008-01-01

    Malaysian locally processed raw food products are widely used as main ingredients in local cooking. Previous studies showed that these food products have a positive correlation with the incidence of cancer. The cytotoxicity effect was evaluated using MTT assay (3-(4,5-dimetil-2-thiazolil)-2,5-diphenyl-2H-tetrazolium bromide) against Chang liver cells at 2000 microg/ml following 72 h incubation. Findings showed all methanol extracts caused a tremendous drop in the percentage of cell viability at 2000 microg/ml (shrimp paste - 41.69+/-3.36%, salted fish - 37.2+/-1.06%, dried shrimp - 40.32+/-1.8%, p<0.05). To detect DNA damage in a single cell, alkaline Comet Assay was used. None of the extracts caused DNA damage to the Chang liver cells at 62.5 microg/ml following 24 h incubation, as compared to the positive control, hydrogen peroxide (tail moment - 9.50+/-1.50; tail intensity - 30.50+/-2.50). Proximate analysis which was used for the evaluation of macronutrients in food showed that shrimp paste did not comply with the protein requirement (<25%) as in Food Act 1983. Salt was found in every sample with the highest percentage being detected in shrimp paste which exceeded 20%. Following heavy metal analysis (arsenic, cadmium, lead and mercury), arsenic was found in every sample with dried shrimps showing the highest value as compared to the other samples (6.16 mg/kg). In conclusion, several food extracts showed cytotoxic effect but did not cause DNA damage against Chang liver cells. Salt was found as the main additive and arsenic was present in every sample, which could be the probable cause of the toxicity effects observed. PMID:17900779

  4. The role of radiation transport in the thermal response of semitransparent materials to localized laser heating

    SciTech Connect

    Colvin, Jeffrey; Shestakov, Aleksei; Stoelken, James; Vignes, Ryan

    2011-03-01

    Lasers are widely used to modify the internal structure of semitransparent materials for a wide variety of applications, including waveguide fabrication and laser glass damage healing. The gray diffusion approximation used in past models to describe radiation cooling is not adequate for these materials, particularly near the heated surface layer. In this paper we describe a computational model based upon solving the radiation transport equation in 1D by the P{sub n} method with {approx}500 photon energy bands, and by multi-group radiation diffusion in 2D with fourteen photon energy bands. The model accounts for the temperature-dependent absorption of infrared laser light and subsequent redistribution of the deposited heat by both radiation and conductive transport. We present representative results for fused silica irradiated with 2-12 W of 4.6 or 10.6 {mu}m laser light for 5-10 s pulse durations in a 1 mm spot, which is small compared to the diameter and thickness of the silica slab. We show that, unlike the case for bulk heating, in localized infrared laser heating radiation transport plays only a very small role in the thermal response of silica.

  5. Local heat transfer measurement with liquid crystals on rotating surfaces including non-axisymmetric cases

    NASA Technical Reports Server (NTRS)

    Metzger, D. E.; Kim, Y. K.

    1993-01-01

    An overview and summary of test methods and results are given for the problem of measuring local heat transfer on rotating surfaces that model gas turbine engine disks. Disk cavity situations generically similar to those encountered in the high pressure stage disk cooling are considered, with cooling air supplied both at or near the wheel centerline as well as through single or multiple jets impinging outboard on the wheel near the blade attachment region. In some situations provision has been made for ingestion into the disk-cavity from the gas path region radially outboard of the disk. Local heat transfer rates in all cases are determined from the color display from a thin coating of encapsulated liquid crystals sprayed onto the disk, in conjunction with use of a video camera and computer vision system. For cases with axisymmetric disk surfaces, the coated surfaces are illuminated and viewed continuously, and detailed radial distributions of local Nusselt number are obtained. For non-axisymmetric disk surfaces, such as encountered in the vicinity of bolt heads, the disk is illuminated with stroboscopic light, and a method has been developed and used to synchronize the computer frame grabber with the illumination.

  6. Light masking of circadian rhythms of heat production, heat loss, and body temperature in squirrel monkeys

    NASA Technical Reports Server (NTRS)

    Robinson, E. L.; Fuller, C. A.

    1999-01-01

    Whole body heat production (HP) and heat loss (HL) were examined to determine their relative contributions to light masking of the circadian rhythm in body temperature (Tb). Squirrel monkey metabolism (n = 6) was monitored by both indirect and direct calorimetry, with telemetered measurement of body temperature and activity. Feeding was also measured. Responses to an entraining light-dark (LD) cycle (LD 12:12) and a masking LD cycle (LD 2:2) were compared. HP and HL contributed to both the daily rhythm and the masking changes in Tb. All variables showed phase-dependent masking responses. Masking transients at L or D transitions were generally greater during subjective day; however, L masking resulted in sustained elevation of Tb, HP, and HL during subjective night. Parallel, apparently compensatory, changes of HL and HP suggest action by both the circadian timing system and light masking on Tb set point. Furthermore, transient HL increases during subjective night suggest that gain change may supplement set point regulation of Tb.

  7. The local heating effect by magnetic nanoparticles aggregate on support lipid bilayers.

    PubMed

    Wang, Changling; Xu, Ruizhi; Tang, Liming

    2013-07-01

    In this paper, we established a theoretical model to investigate the local heating effect of magnetic nanoparticles (MNPs) aggregate on the support lipid bilayers (SLBs) under external alternating current (AC) magnetic field, which may be helpful to understand hyperthermia at single cell level. Using atomic force microscope (AFM), the transformation of the support phospholipid bilayers surrounding MNPs aggregate was observed in real-time. We found that the fluidity of lipid bilayers changed when the size of MNPs aggregate larger than 200 nm, as a result of magnetic heating in the AC magnetic field. These experimental data were consistent with the simulation results, which demonstrated the valid of our established model, as well as described more realistically the above phenomenon. PMID:23909135

  8. Sawtooth stabilization by localized electron cyclotron heating in a tokamak plasma

    SciTech Connect

    Hanada, K.; Tanaka, H.; Iida, M.; Minami, T.; Maekawa, T.; Terumichi, Y.; Tanaka, S. . Dept. of Physics); Ide, S. . Naka Fusion Research Establishment); Nakamura, M. ); Yamada, M.; Manickam, J.; White, R.B. . Plasma Physics Lab.)

    1990-11-01

    Sawtooth oscillations (STO) in the ohmically heated WT-3 tokamak are strongly modified or suppressed by localized electron cyclotron resonance heating (ECH) near the q = 1 surface, where q refers to the safety factor. The effect of ECH is much stronger when it is applied on the high field side (the inner side of the tokamak) as compared to the low field side (outer side). Complete suppression of the STO is achieved for the duration of the ECH when it is applied on the high field side, in a low density plasma, provided the ECH power exceeds a thresholds value. The STO stabilization is attributed to a modification of the current density profile by hot electrons generated by ECH, which reduces the shear in the q = region. 14 refs., 5 figs.

  9. Low-Temperature Heat Capacity and Localized Vibrational Modes in Natural and Synthetic Tetrahedrites

    SciTech Connect

    Lara-Curzio, Edgar; May, Andrew F; Delaire, Olivier A; McGuire, Michael A; Lu, Xu; Li, Cheng-Yun; Case, Eldon D; Morelli, Donold

    2014-01-01

    The heat capacity of natural (Cu12-x (Fe, Zn, Ag)x(Sb, As)4S13) and synthetic (Cu12-xZnxSb4S13 with x=0, 1, 2) tetrahedrite compounds was measured between 2K and 380K. It was found that the temperature dependence of the heat capacity can be described using a Debye term and three Einstein oscillators with characteristic temperatures that correspond to energies of ~1.0 meV, ~2.8 meV and ~8.4 meV. The existence of localized vibration modes, which are assigned to the displacements of the trigonally coordinated Cu atoms in the structure, is discussed in the context of anharmonicity and its effect on the low lattice thermal conductivity exhibited by these compounds.

  10. Local advection of sensible heat in the snowmelt landscape of Arctic tundra

    NASA Astrophysics Data System (ADS)

    Neumann, Natasha; Marsh, Philip

    1998-07-01

    The spring landscape of the Arctic tundra is dominated by a snow cover which is highly variable in depth owing to redistribution by wind. Because of different energy dynamics, this heterogeneous land cover produces a horizontal transfer of energy at a small scale, a process termed local advection. An advection efficiency term (FS), which represents the fraction of the sensible heat from snow-free patches which is advected to snow patches, was determined from field studies and published model results. Energy balance calculations demonstrated the strong contrast between the two surface cover types that drive advective processes, and FS was found to decrease exponentially with decreasing snow cover fraction. The field results suggest higher values of FS compared with the model results for single snow patches of varying size, but similar in magnitude to FS for multiple small snow patches. Utilizing exponential best-fit relationships between FS and fractional snow cover shows an increase in sensible heat flux of over 100% for low snow cover fractions. When considering the average flux over a composite snow and snow-free surface, the average sensible heat flux obtained from weighting the fluxes for each surface by their respective areas underestimates the composite flux when compared with when advection is considered.This work provides a simple method to estimate the effect of local advection on sensible heat to snow patches and the average flux from a composite surface during the snowmelt period, using only fluxes calculated independently for 0% snow cover and 100% snow cover and an estimate of FS . It demonstrates a good first estimate of the role of advection, but for future study the influence of wind speed, patch distribution patterns and fetch lengths needs to be considered more explicitly. This has important implications in studies of areal energy fluctuations over melting, patchy snow covers, basin water balance studies and regional and global climate modelling.

  11. The effect of intermittent local heat and cold on labor pain and child birth outcome

    PubMed Central

    Ganji, Zhila; Shirvani, Marjan A.; Rezaei-Abhari, Farideh; Danesh, Mahmonir

    2013-01-01

    Background: Labor pain is one of the severest pains that cause many women request cesarean section for fear of pain. Thus, controlling labor pain is a major concern of maternity care. Nowadays, interest in non-pharmacological pain relief methods has been increased because of their lower side effects. The effects of discrete heat and cold on decreasing labor pain have been reported but there was no evaluation of the effects of simultaneous heat and cold. The aim of this study was to investigate the effect of intermittent heat and cold on pain severity and childbirth outcomes. Materials and Methods: This study was a randomized controlled trial. Sixty-four nulliparous women with term, One fetus, and low-risk pregnancy were divided into the intervention (32 participants) and the control group (32 participants) by random allocation. Excluding criteria were: administration of pain relief drugs, skin disease in the field of intervention, fetal distress, bleeding, fever, and disagreement with participation in the study. Warm and cold packs were used intermittently on low back and lower abdomen during the first phase and on perineum during the second phase of labor. Pain intensity was assessed with Visual Analogue Scale. Descriptive statistic, chi square, and t-test were used for data analysis. Results: There were no significant differences in demographic and midwifery characteristics and the baseline pain between two groups. The pain was significantly lower in intervention group during the first and second phases of labor. Duration of the first and third phases of labor was shorter in the case group. There were no significant differences in type of delivery, perineal laceration, oxytocin uptake, fetal heart rate, and APGAR between two groups. Discussion: Local warming with intermittent cold pack can reduce labor pain without adverse effects on maternal and fetal outcomes. It is an inexpensive and simple method. Conclusion: Intermittent local heat and cold therapy is a no pharmalogical, safe and effective method to relief labor pain. PMID:24403926

  12. The reliability of a heat acclimation state test prescribed from metabolic heat production intensities.

    PubMed

    Willmott, A G B; Hayes, M; Dekerle, J; Maxwell, N S

    2015-10-01

    Acclimation state indicates an individual's phenotypic response to a thermally stressful environment, where changes in heat dissipation capacity are determined during a heat acclimation state test (HAST). Variations in thermoregulatory and sudomotor function are reported while exercising at intensities relative to maximal oxygen uptake. This inter-individual variation is not true when intensity is prescribed to elicit a fixed rate of metabolic heat production (?prod). This study investigated the reliability of peak Tre and two composite measures (sweat gain and sweat setpoint) derived from indices of thermosensitivity during a HAST prescribed from ?prod intensities. Fourteen participants (meanSD; age 233 years, stature 1747cm, body mass 75.09.4kg, body surface area 1.90.1m(2), peak oxygen consumption [V?O2peak] 3.490.53Lmin(-1)) completed a lactate threshold-V?O2peak test and two duplicate ?prod HASTs on a cycle ergometer. The HAST consisted of three, 30-min periods of exercise at fixed ?prod intensities relative to body mass (3, 4.5 and 6Wkg(-1)), within hot dry conditions (44.71.8C and 18.14.7% relative humidity). Peak Tre (38.200.36 vs. 38.160.42C, p=0.54), sweat setpoint (36.760.34 and 36.790.38C, p=0.68) and sweat gain (0.370.14 and 0.400.18gs(-1)C(-1), p=0.40) did not differ between HASTs. Typical error of measurement (TEM), coefficient variation (CV) and intra-class coefficient of correlation (ICC) were 0.19C, 0.5% and 0.80 for peak Tre, 0.21C, 0.6% and 0.65 for sweat setpoint and 0.09gs(-1)C(-1), 28% and 0.68 for sweat gain, respectively. The use of fixed ?prod intensities relative to body mass is a reliable method for measuring Tre and ascertaining sweat setpoint during a HAST, whereas, sweat gain displays greater variability. A ?prod HAST appears sufficiently reliable for quantifying heat acclimation state, where TEM in peak Tre and sweat setpoint are small enough to identify physiologically meaningful improvements post-intervention. PMID:26590454

  13. A mathematical model of heat flow in a thermopile for measuring muscle heat production: implications for design and signal analysis.

    PubMed

    Barclay, C J

    2015-09-01

    Contracting muscles produce heat which largely arises from the biochemical reactions that provide the energy for contraction. Measurements of muscle heat production have made, and continue to make, important contributions to our understanding of the bases of contraction. Most measurements of muscle heat production are made using a thermopile, consisting of a series of thermocouples arranged so that alternate thermocouples are in thermal contact with the muscle and with an isothermal reference. In this study, a mathematical model was constructed of a muscle lying on a thermopile consisting of antimony-bismuth thermocouples sandwiched between polymer sheets. The validity of the model was demonstrated by its ability to accurately predict thermopile outputs in response to applying heat to the thermopile surface, to generating heat in the thermocouples using the Peltier effect and to adding heat capacity on the thermopile surface. The model was then used to show how practical changes to thermopile construction could minimise response time and thermopile heat capacity and allow measurement of very low rates of heat production. The impulse response of a muscle-thermopile system was generated using the model and used to illustrate how a measured signal can be deconvolved with the impulse response to correct for lag introduced by the thermopile. PMID:26234299

  14. Overexpression of a chloroplast-localized small heat shock protein OsHSP26 confers enhanced tolerance against oxidative and heat stresses in tall fescue.

    PubMed

    Kim, Kyung-Hee; Alam, Iftekhar; Kim, Yong-Goo; Sharmin, Shamima Akhtar; Lee, Ki-Won; Lee, Sang-Hoon; Lee, Byung-Hyun

    2012-02-01

    Small heat shock proteins are involved in stress tolerance. We previously isolated and characterized a rice cDNA clone, Oshsp26, encoding a chloroplast-localized small heat shock protein that is expressed following oxidative or heat stress. In this study, we transferred this gene to tall fescue plants by an Agrobacterium-mediated transformation system. The integration and expression of the transgene was confirmed by PCR, Southern, northern, and immunoblot analyzes. Compared to the control plants, the transgenic plants had significantly lower electrolyte leakage and accumulation of thiobarbituric acid-reactive substances when exposed to heat or methyl viologen. The photochemical efficiency of photosystem II (PSII) (Fv/Fm) in the transgenic tall fescue plants was higher than that in the control plants during heat stress (42°C). These results suggest that the OsHSP26 protein plays an important role in the protection of PSII during heat and oxidative stress in vivo. PMID:21984008

  15. Localization of heat shock proteins in cerebral cortical cultures following induction by celastrol.

    PubMed

    Chow, Ari M; Tang, Derek W F; Hanif, Asad; Brown, Ian R

    2014-11-01

    Hsp70, Hsp32, and Hsp27 were induced by celastrol in rat cerebral cortical cultures at dosages that did not affect cell viability. Pronounced differences were observed in the cellular localization of these heat shock proteins in cell types of cerebral cortical cultures. Celastrol-induced Hsp70 localized to the cell body and cellular processes of neurons that were identified by neuron-specific ?III-tubulin. Hsp70 was not detected in adjacent GFAP-positive glial cells that demonstrated a strong signal for Hsp27 and Hsp32 in both glial cell bodies and cellular processes. Cells in the cerebral cortex region of the brain are selectively impacted during the progression of Alzheimer's disease which is a "protein misfolding disorder." Heat shock proteins provide a line of defense against misfolded, aggregation-prone proteins. Celastrol is a potential agent to counter this neurodegenerative disorder as recent evidence indicates that in vivo administration of celastrol in a transgenic model of Alzheimer's reduces an important neuropathological hallmark of this disease, namely, amyloid beta pathology that involves protein aggregation. PMID:24700193

  16. Effect of surface roughness on local film cooling effectiveness and heat transfer coefficients

    NASA Astrophysics Data System (ADS)

    Barlow, Douglas N.

    1994-08-01

    In high temperature gas turbine engines, the life cycle of the hot section is extremely dependent on accurate design prediction of component temperature distribution. Particular attention must be paid to the film cooling performance of the first stage turbine stator vanes where the highest heat loads are encountered. Recent investigations have determined during operation the smooth surface of high pressure turbine vanes become rough due to corrosion, oxidation and particulate impact. A transient experimental method has been developed to obtain both local heat transfer and cooling effectiveness information downstream of a row of film cooling holes on a rough flat plate. This investigation provides information on the effects of roughness on film cooling heat transfer for a Reynolds number and dimensionless boundary layer momentum thickness which match conditions applicable to the pressure side of the first stage turbine vane of the Pratt and Whitney F-100-PW229 engine. Data for film cooling on rough surfaces are extremely limited in the literature. However, comparison with the available data is made.

  17. The effect of substrate wettability on the breakdown of a locally heated fluid film

    NASA Astrophysics Data System (ADS)

    Zaitsev, D. V.; Kirichenko, D. P.; Kabov, O. A.

    2015-06-01

    The effect of the equilibrium contact angle of wetting on the dynamics of the dry patch propagation and on the critical heat flux upon the breakdown of a water film that is heated locally from the substrate side is studied experimentally. The equilibrium contact angle is varied from 27 6 to 74 9 (with no changes in the thermophysical properties of the system) through the use of different types of surface grinding. The studies are performed for three flow modes: (a) a fluid film that freely flows down along a substrate with an inclination of 5 to the horizon, (b) a film that moves along a horizontal substrate under the influence of hydrostatic pressure, and (c) a static film on a horizontal substrate. It is found that the substrate wettability has a significant effect on the dry patch propagation rate and its final size in all these cases, but has almost no effect on the threshold heat flux at which the breakdown of a film occurs.

  18. Monitoring local heating around an interventional MRI antenna with RF radiometry

    SciTech Connect

    Ertürk, M. Arcan; El-Sharkawy, AbdEl-Monem M.; Bottomley, Paul A.

    2015-03-15

    Purpose: Radiofrequency (RF) radiometry uses thermal noise detected by an antenna to measure the temperature of objects independent of medical imaging technologies such as magnetic resonance imaging (MRI). Here, an active interventional MRI antenna can be deployed as a RF radiometer to measure local heating, as a possible new method of monitoring device safety and thermal therapy. Methods: A 128 MHz radiometer receiver was fabricated to measure the RF noise voltage from an interventional 3 T MRI loopless antenna and calibrated for temperature in a uniformly heated bioanalogous gel phantom. Local heating (ΔT) was induced using the antenna for RF transmission and measured by RF radiometry, fiber-optic thermal sensors, and MRI thermometry. The spatial thermal sensitivity of the antenna radiometer was numerically computed using a method-of-moment electric field analyses. The gel’s thermal conductivity was measured by MRI thermometry, and the localized time-dependent ΔT distribution computed from the bioheat transfer equation and compared with radiometry measurements. A “H-factor” relating the 1 g-averaged ΔT to the radiometric temperature was introduced to estimate peak temperature rise in the antenna’s sensitive region. Results: The loopless antenna radiometer linearly tracked temperature inside a thermally equilibrated phantom up to 73 °C to within ±0.3 °C at a 2 Hz sample rate. Computed and MRI thermometric measures of peak ΔT agreed within 13%. The peak 1 g-average temperature was H = 1.36 ± 0.02 times higher than the radiometric temperature for any media with a thermal conductivity of 0.15–0.50 (W/m)/K, indicating that the radiometer can measure peak 1 g-averaged ΔT in physiologically relevant tissue within ±0.4 °C. Conclusions: Active internal MRI detectors can serve as RF radiometers at the MRI frequency to provide accurate independent measures of local and peak temperature without the artifacts that can accompany MRI thermometry or the extra space needed to accommodate alternative thermal transducers. A RF radiometer could be integrated in a MRI scanner to permit “self-monitoring” for assuring device safety and/or monitoring delivery of thermal therapy.

  19. Monitoring local heating around an interventional MRI antenna with RF radiometry

    PubMed Central

    Ertürk, M. Arcan; El-Sharkawy, AbdEl-Monem M.; Bottomley, Paul A.

    2015-01-01

    Purpose: Radiofrequency (RF) radiometry uses thermal noise detected by an antenna to measure the temperature of objects independent of medical imaging technologies such as magnetic resonance imaging (MRI). Here, an active interventional MRI antenna can be deployed as a RF radiometer to measure local heating, as a possible new method of monitoring device safety and thermal therapy. Methods: A 128 MHz radiometer receiver was fabricated to measure the RF noise voltage from an interventional 3 T MRI loopless antenna and calibrated for temperature in a uniformly heated bioanalogous gel phantom. Local heating (ΔT) was induced using the antenna for RF transmission and measured by RF radiometry, fiber-optic thermal sensors, and MRI thermometry. The spatial thermal sensitivity of the antenna radiometer was numerically computed using a method-of-moment electric field analyses. The gel’s thermal conductivity was measured by MRI thermometry, and the localized time-dependent ΔT distribution computed from the bioheat transfer equation and compared with radiometry measurements. A “H-factor” relating the 1 g-averaged ΔT to the radiometric temperature was introduced to estimate peak temperature rise in the antenna’s sensitive region. Results: The loopless antenna radiometer linearly tracked temperature inside a thermally equilibrated phantom up to 73 °C to within ±0.3 °C at a 2 Hz sample rate. Computed and MRI thermometric measures of peak ΔT agreed within 13%. The peak 1 g-average temperature was H = 1.36 ± 0.02 times higher than the radiometric temperature for any media with a thermal conductivity of 0.15–0.50 (W/m)/K, indicating that the radiometer can measure peak 1 g-averaged ΔT in physiologically relevant tissue within ±0.4 °C. Conclusions: Active internal MRI detectors can serve as RF radiometers at the MRI frequency to provide accurate independent measures of local and peak temperature without the artifacts that can accompany MRI thermometry or the extra space needed to accommodate alternative thermal transducers. A RF radiometer could be integrated in a MRI scanner to permit “self-monitoring” for assuring device safety and/or monitoring delivery of thermal therapy. PMID:25735295

  20. Localizing the lipid products of PI3K? in neutrophils

    PubMed Central

    Norton, Laura; Lindsay, Yvonne; Deladeriere, Arnaud; Chessa, Tamara; Guillou, Herv; Suire, Sabine; Lucocq, John; Walker, Simon; Andrews, Simon; Segonds-Pichon, Anne; Rausch, Oliver; Finan, Peter; Sasaki, Takehiko; Du, Cheng-Jin; Bretschneider, Till; Ferguson, G. John; Hawkins, Phillip T.; Stephens, Len

    2016-01-01

    Class I phosphoinositide 3-kinases (PI3Ks) are important regulators of neutrophil migration in response to a range of chemoattractants. Their primary lipid products PtdIns(3,4,5)P3 and PtdIns(3,4)P2 preferentially accumulate near to the leading edge of migrating cells and are thought to act as an important cue organizing molecular and morphological polarization. We have investigated the distribution and accumulation of these lipids independently in mouse neutrophils using eGFP-PH reportersand electron microscopy (EM). We found that authentic mouse neutrophils rapidly polarized their Class I PI3K signalling, as read-out by eGFP-PH reporters, both at the up-gradient leading edge in response to local stimulation with fMLP as well as spontaneously and randomly in response to uniform stimulation. EM studies revealed these events occurred at the plasma membrane, were dominated by accumulation of PtdIns(3,4,5)P3, but not PtdIns(3,4)P2, and were dependent on PI3K? and its upstream activation by both Ras and G??s. PMID:26596865

  1. Constructing a model of 3D radiogenic heat production in Ireland

    NASA Astrophysics Data System (ADS)

    Willmot Noller, N. M.; Daly, J. S.

    2012-04-01

    Heat production values in the crust and mantle rock inform heat flow density data to provide crucial information about the structure of the Earth's lithosphere. In addition, accurate models of horizontal and vertical distribution of heat production can help to define geothermal exploration targets. Low-enthalpy district scale space heating and Enhanced Geothermal Systems (EGS) using hot, dry rock may provide sustainable energy resources in regions currently perceived as having low geothermal energy potential. Ireland is located within stable lithosphere, unaffected by recent tectonism and volcanism, and has an estimated heat flow range below the measured global continental average. Nevertheless, borehole data indicate that heat production is variable across the island, with anomalously high rates observed, for example, in Cavan, Meath and Antrim. Data coverage is, however, poor. Radioactive isotopic decay generates heat in rock. By using established heat production constants and known concentrations of unstable isotopes of uranium, thorium and potassium, along with rock density values, a heat production rate in ?W m -3 is obtained. With the objective of compiling the first comprehensive database of information about the Irish lithosphere, in three dimensions, the authors present here initial results obtained from published and unpublished whole-rock major and trace element analyses. The presence of systematic trends correlating heat production to properties such as age and lithology are also investigated. Offering insight into the vertical component of heat production distribution, Irish xenoliths emplaced in Lower Carboniferous volcanics are regarded as a reliable proxy for the present-day lower crust. Their geochemical composition gives heat production values that are higher than expected for the depths indicated by their thermobarometric data, suggesting that heat production rates do not simply reduce with depth.

  2. The Local Balances of Vorticity and Heat for Blocking Anticyclones in a Spectral General Circulation Model.

    NASA Astrophysics Data System (ADS)

    Mullen, Steven L.

    1986-07-01

    Blocking anticyclones that appear in perpetual January simulations of a spectral general circulation model are examined. Blocks in three geographical regions are studied: the North Pacific, the North Atlantic and western North America. Local time-averaged balances of vorticity and heat are evaluated for composite cases of blocking. The following common relationships emerged from these budgets.The time-mean divergence term is, in general, a flat-order term in the vorticity balance throughout the troposphere and its pattern over severe orography is closely related to the underlying topography. Above the surface layer, the horizontal advection of time-mean absolute vorticity by the mean wind mainly balances the divergence term with the net effect of the time-mean vorticity forcing being a tendency for the blocking pattern to propagate downstream. The transient eddy vorticity transports act to shift the block upstream and hence they mainly offset the downstream tendency due to the time-mean flow; the magnitude of the eddy vorticity term is typically one-third to one-half that of the divergence or advection terms alone. Frictional dissipation is negligible everywhere except near the ground where it primarily offsets the divergence term.The horizontal advection of the time-mean temperature field by the mean wind throughout the troposphere is a first-order term in the beat balance and is mainly responsible for maintaining the block's thermal perturbations; it is predominately balanced by adiabatic heating in the free troposphere and by diabatic heating near the surface. Transient eddy heat transports act to dissipate the block's thermal perturbations at all levels, while diabatic heating does not exhibit a systematic relationship with the temperature field at any level.A quasi-geostrophic diagnosis of the ageostrophic motion field suggests that dynamical processes which strongly affect the vorticity balance may be more important to the maintenance of model blocks than processes which strongly affect the heat balance. The mountains appear capable of influencing the shape of the model blocks, but preliminary results indicate that orographic forcing may not be absolutely essential for the blocking process to occur in the model.

  3. Effects of polypropylene and polytetrafluoroethylene prostheses for abdominal plasty on local and systemic cytokine production.

    PubMed

    Grigoryuk, A A; Turmova, E P

    2014-02-01

    We studied the effects of Esphyl polypropylene mesh and Ecoflon polytetrafluoroethylene endoprostheses on local and systemic production of cytokines. Polytetrafluoroethylene is a more reactogenic material than polypropylene; it stimulates mainly the local production of pro-inflammatory cytokines. The local anti-inflammatory effect of polypropylene was less pronounced, but persisted for longer time. PMID:24771444

  4. THERM 2.0: a PC Program for Analyzing Two-Dimensional HeatTransfer through Building Products

    SciTech Connect

    Windows and Daylighting Group

    1997-12-08

    THERM is a state-of-the-art, Microsoft Windows{trademark}-based computer program developed at Lawrence Berkeley National Laboratory (LBNL) for use by building component manufacturers, engineers, educators, students, architects, and others interested in heat transfer. Using THERM, you can model two-dimensional heat-transfer effects in building components such as windows, walls, foundations, roofs, and doors; appliances; and other products where thermal bridges are of concern. THERM's heat-transfer analysis allows you to evaluate a product's energy efficiency and local temperature patterns, which may relate directly to problems with condensation, moisture damage, and structural integrity. THERM's two-dimensional conduction heat-transfer analysis is based on the finite-element method, which can model the complicated geometries of building products. The program's graphic interface allows you to draw cross sections of products or components to be analyzed. To create the cross sections, you can trace imported files in DXF or bitmap format, or input the geometry from known dimensions. Each cross section is represented by a combination of polygons. You define the material properties for each polygon and introduce the environmental conditions to which the component is exposed by defining the boundary conditions surrounding the cross section. Once the model is created, the remaining analysis (mesher and heat transfer) is automatic. You can view results from THERM in several forms, including U-factors, isotherms, heat-flux vectors, and local temperatures. This version of THERM includes several new technical and user interface features; the most significant is a radiation view-factor algorithm. This feature increases the accuracy of calculations in situations where you are analyzing non-planar surfaces that have different temperatures and exchange energy through radiation heat transfer. This heat-transfer mechanism is important in greenhouse windows, hollow cavities, and some aluminum frames. THERM is a module of the WINDOW+5 program under development by LBNL. WINDOW+5 is the next generation of the WINDOW software series and is being developed for the Microsoft Windows{trademark} operating environment. THERM's results can be used with WINDOW's center-of-glass optical and thermal models to determine total window product U-factors and Solar Heat Gain Coefficients. These values can be used, in turn, with the RESFEN program, which calculates total annual energy requirements in typical residences throughout the United States.

  5. SPECIFIC HEATS OF COTTONSEED AND ITS CO-PRODUCTS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Most of the annual crops are harvested and stored for the entire crushing season until the new crop year begins. It is desirable to have the specific heat data of the agricultural materials for the engineer to manage the heat transfer problem associated with each crop during the storage. Thermal p...

  6. Local non-similarity solution of coupled heatMass transfer of a flat plate with uniform heat flux in a laminar parallel flow

    NASA Astrophysics Data System (ADS)

    Zhang, Yuwen; Chen, Zhongqi; Chen, Mingyong

    1996-04-01

    The coupled heat and mass transfer problem of gas flow over a UHF flat plate with its wall coated with sublimable substance has been solved by local non-similarity method. Considerations have been given also to the effect of non-saturation of the sublimable substance in the oncoming flow and the normal injection velocity at the surface. Analytical results are given for local Nusselt and Sherwood numbers at the various locations.

  7. Local Production of Chemokines during Experimental Vaginal Candidiasis

    PubMed Central

    Saavedra, Michael; Taylor, Brad; Lukacs, Nicholas; Fidel, Paul L.

    1999-01-01

    Recurrent vulvovaginal candidiasis, caused by Candida albicans, is a significant problem in women of childbearing age. Although cell-mediated immunity (CMI) due to T cells and cytokines is the predominant host defense mechanism against C. albicans at mucosal tissue sites, host defense mechanisms against C. albicans at the vaginal mucosa are poorly understood. Based on an estrogen-dependent murine model of vaginal candidiasis, our data suggest that systemic CMI is ineffective against C. albicans vaginal infections. Thus, we have postulated that local immune mechanisms are critical for protection against infection. In the present study, the kinetic production of chemokines normally associated with the chemotaxis of T cells, macrophages (RANTES, MIP-1α, MCP-1), and polymorphonuclear neutrophils (MIP-2) was examined following intravaginal inoculation of C. albicans in estrogen-treated or untreated mice. Results showed significant increases in MCP-1 protein and mRNA in vaginal tissue of infected mice as early as 2 and 4 days postinoculation, respectively, that continued through a 21-day observation period, irrespective of estrogen status. No significant changes were observed with RANTES, MIP-1α, or MIP-2, although relatively high constitutive levels of RANTES mRNA and MIP-2 protein were observed. Furthermore, intravaginal immunoneutralization of MCP-1 with anti-MCP-1 antibodies resulted in a significant increase in vaginal fungal burden early during infection, suggesting that MCP-1 plays some role in reducing the fungal burden during vaginal infection. However, the lack of changes in leukocyte profiles in vaginal lavage fluids collected from infected versus uninfected mice suggests that MCP-1 functions to control vaginal C. albicans titers in a manner independent of cellular chemotactic activity. PMID:10531235

  8. RELATIONSHIP BETWEEN AGING AND NUTRITIONAL CONTROLLED GROWTH RATE ON HEAT PRODUCTION OF EWE LAMBS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of this study was to determine how reducing growth rate nutritionally alters the relationship between heat production per unit body weight and aging. Fasting heat production of 12 Dorset ewe lambs at 114 ± 2 d of age was determined, and ewes were assigned to treatments. Treatments co...

  9. HEAT PRODUCTION OF GROWING HEIFERS THAT DIFFER IN COMPOSITION OF BOS INDICUS AND BOS TAURUS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Previous studies using indirect-calorimetry have reported that heat production scaled to body weight of Bos indicus cross cattle is lower than that of Bos taurus cattle; however, in a comparative slaughter study, estimated fasting heat production of Bos indicus x Bos taurus steers was not lower than...

  10. The composition of the thermal oxidative transformation liquid products in the oil shale under electrophysical heating

    NASA Astrophysics Data System (ADS)

    Ivanov, A. A.; Bukharkin, A. A.; Martemyanov, S. M.; Savelyev, V. V.; Golovko, A. K.

    2015-10-01

    The data of liquid and solid products of thermal decomposition of oil shale under the influence of electrophysical heating are described in the article. Qualitative and quantitative composition of products is compared with the composition of initial oil shale. Qualitative characteristics of organic matter transformations of oil shale are determined under electrophysics heating.

  11. 77 FR 74027 - Certain Integrated Circuit Packages Provided with Multiple Heat-Conducting Paths and Products...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-12

    ... COMMISSION Certain Integrated Circuit Packages Provided with Multiple Heat- Conducting Paths and Products..., California (collectively, ``ITRI''). 77 FR 39735 (Jul. 5, 2012). The complaint, as amended, alleges... integrated circuit packages provided with multiple heat-conducting paths and products containing same...

  12. Heating of thin products by means of transverse-flux inductors

    NASA Astrophysics Data System (ADS)

    1980-02-01

    There are some forms of metallic products which do not lend themselves well to induction heating upon first consideration, either because of their shape (small thickness) or their nature (materials with low resistance). In particular, this applies to all products in the form of a thin sheet. Various applications are suggested such as the drying of the sheet after pickling the heating of the sheet in order to dry or harden varnish lacquer, and the heat treatment of aluminium sheet.

  13. Local heat activation of single myosins based on optical trapping of gold nanoparticles.

    PubMed

    Iwaki, Mitsuhiro; Iwane, Atsuko H; Ikezaki, Keigo; Yanagida, Toshio

    2015-04-01

    Myosin is a mechano-enzyme that hydrolyzes ATP in order to move unidirectionally along actin filaments. Here we show by single molecule imaging that myosin V motion can be activated by local heat. We constructed a dark-field microscopy that included optical tweezers to monitor 80 nm gold nanoparticles (GNP) bound to single myosin V molecules with nanometer and submillisecond accuracy. We observed 34 nm processive steps along actin filaments like those seen when using 200 nm polystyrene beads (PB) but dwell times (ATPase activity) that were 4.5 times faster. Further, by using DNA nanotechnology (DNA origami) and myosin V as a nanometric thermometer, the temperature gradient surrounding optically trapped GNP could be estimated with nanometer accuracy. We propose our single molecule measurement system should advance quantitative analysis of the thermal control of biological and artificial systems like nanoscale thermal ratchet motors. PMID:25736894

  14. Review of energy confinement and local transport scaling results in neutral-beam-heated tokamaks

    SciTech Connect

    Kaye, S.M.

    1985-05-01

    Over the past several years, tokamak neutral beam injection experiments have evolved from the brute force study of the effects of global discharge characteristics (I/sub p/, anti n/sub e/, P/sub heat/, etc.) on energy confinement to the appreciation that there are effects more subtle, yet controllable, that may influence confinement dramatically. While this evolution from first to second generation experiments is derived from an empirical understanding of low and high energy confinement modes and how to achieve them operationally, the underlying physics is still unknown. Several theories with different physical bases appear to describe the global scaling of the low confinement mode discharges quite well. On the other hand, little agreement has been found between theoretical and experimentally deduced values of local transport coefficients. While it is known operationally how to achieve any one of several types of high confinement mode discharges, here too, the underlying physics of the transport associated with these modes is poorly understood.

  15. Kondo signature in heat transfer via a local two-state system.

    PubMed

    Saito, Keiji; Kato, Takeo

    2013-11-22

    We study the Kondo effect in heat transport via a local two-state system. This system is described by the spin-boson Hamiltonian with Ohmic dissipation, which can be mapped onto the Kondo model with anisotropic exchange coupling. We calculate thermal conductance by the Monte Carlo method based on the exact formula. Thermal conductance has a scaling form ?=(k(B)(2)T(K)/?)f(?,T/T(K)), where T(K) and ? indicate the Kondo temperature and dimensionless coupling strength, respectively. Temperature dependence of conductance is classified by the Kondo temperature as ? is proportional to (T/T(K))(3) for TT(K). Similarities to the Kondo signature in electric transport are discussed. PMID:24313492

  16. New industrial heat pump applications to fructose production

    SciTech Connect

    Not Available

    1990-04-01

    An energy cost reduction study of the American Fructose Decatur,Inc. High Fructose Corn Syrup process has been completed. The objective was to find cost effective energy cost reduction projects and to develop a coherent strategy for realizing the savings. There are many possible options for reducing energy cost. To facilitate a fair comparison of the options, Pinch Technology was used to identify appropriate heat recovery, heat pumping and cogeneration options. Of particular interest were the opportunities for utilizing heat pumps, for energy cost reduction or other profit increasing uses. Therefore, where a heat pumping scheme was identified, its merits relative to other potential projects was carefully evaluated to ensure that the heat pump was technically and economically sound. It is felt that the results obtained in this study are applicable to other wet corn milling sites which include a refinery section, due to the similarity of processes throughout the industry. This study and others indicate that reductions in thermal energy consumption of 15--25% can be expected through increased heat recovery. Also, the use of MVR and thermocompression evaporators is appropriate and additional economically viable opportunities exist for using industrial heat pumps to increase even further the level of energy cost reduction achievable. 17 figs., 4 tabs.

  17. Localization of heat shock protein 110 in canine mammary gland tumors.

    PubMed

    Okada, Satoru; Furuya, Masaru; Takenaka, Shigeo; Fukui, Ayano; Matsubayashi, Makoto; Tani, Hiroyuki; Sasai, Kazumi

    2015-10-15

    Heat shock proteins (HSPs) function as molecular chaperones in the regulation of protein folding, conformation, and assembly; in addition, they also protect cells from protein-protein aggregation resulting from cellular stress. Recently, HSPs were shown to be overexpressed in several human cancer cells compared with normal cells. HSPs are considered to be related to apoptosis-associated proteins, and inhibition of apoptosis promotes tumor growth. Canine mammary gland tumors have received a great deal of attention from researchers due to the many common biological and histological characteristics that they share with human tumors. We previously confirmed that HSP110 is a canine mammary gland tumor antigen and reported that HSP110 mRNA expression significantly increased in tumor tissue. We have now created a functional recombinant canine HSP110 protein and a rabbit anti-HSP110 polyclonal antibody. This recombinant protein can refold heat-denatured firefly luciferase at 42C. Immunohistochemical analysis showed that HSP110 was mainly localized in the cytoplasm of epithelial and interstitial cells in canine mammary gland tumors. Extensive genomic research has revealed genetic similarities between humans and dogs; comparative oncological studies between these species have made remarkable progress. The results reported here contribute valuable oncological knowledge for the development of novel therapeutic methods in both veterinary science and human medicine. PMID:26292766

  18. Low-temperature heat capacity and localized vibrational modes in natural and synthetic tetrahedrites

    SciTech Connect

    Lara-Curzio, E. May, A. F.; Delaire, O.; McGuire, M. A.; Lu, X.; Liu, Cheng-Yun; Case, E. D.; Morelli, D. T.

    2014-05-21

    The heat capacity of natural (Cu{sub 12−x} (Fe, Zn, Ag){sub x}(Sb, As){sub 4}S{sub 13}) and synthetic (Cu{sub 12−x}Zn{sub x}Sb{sub 4}S{sub 13} with x = 0, 1, 2) tetrahedrite compounds was measured between 2 K and 380 K. It was found that the temperature dependence of the heat capacity can be described using a Debye term and three Einstein oscillators with characteristic temperatures that correspond to energies of ∼1.0 meV, ∼2.8 meV, and ∼8.4 meV. The existence of localized vibrational modes, which are assigned to the displacements of the trigonally coordinated Cu atoms in the structure, is discussed in the context of anharmonicity and its effect on the low lattice thermal conductivity exhibited by these compounds.

  19. New industrial heat pump applications to textile production

    SciTech Connect

    1990-12-01

    Application of pinch technology to the US industries in an early screening study has identified potential for heat pumps in several standard processes such as distillation and drying processes. Due to lack process information, the previous study was not able to draw any definite conclusion concerning the heat pump application potential in textile process. However, the commonly encountered drying process in the finishing section of textile plant has been shown to create opportunities for heat pump placement. The site selected for this study is a textile plant in North Carolina and the participating utility is Duke Power Company. The objective of this study is to further identify the energy savings potential through advanced heat pumps and other energy conservation methods developed in the context of pinch technology. The key findings of this study are as follows. The previously unrecoverable waste heat from the exhaust air can now be reclaimed through a spray type air washer and heat pump system. The recommended heat pump system recovers heat from the looper exhaust and use it to preheat the air in the gas tenter. A reduction of 50% of the gas consumption in the tenter can be achieved. The removal of lint from the exhaust air reduced the potential of air pollution. The collected lint can be burned in the boiler as a supplemental fuel source to reduce the fuel consumption in the plant. With fuel price predicted to go up and electricity price remain relatively stable in the future, the heat pump system can payback in less than three years. 15 figs., 4 tabs.

  20. A computational study of droplet evaporation with fuel vapor jet ejection induced by localized heat sources

    NASA Astrophysics Data System (ADS)

    Sim, Jaeheon; Im, Hong G.; Chung, Suk Ho

    2015-05-01

    Droplet evaporation by a localized heat source under microgravity conditions was numerically investigated in an attempt to understand the mechanism of the fuel vapor jet ejection, which was observed experimentally during the flame spread through a droplet array. An Eulerian-Lagrangian method was implemented with a temperature-dependent surface tension model and a local phase change model in order to effectively capture the interfacial dynamics between liquid droplet and surrounding air. It was found that the surface tension gradient caused by the temperature variation within the droplet creates a thermo-capillary effect, known as the Marangoni effect, creating an internal flow circulation and outer shear flow which drives the fuel vapor into a tail jet. A parametric study demonstrated that the Marangoni effect is indeed significant at realistic droplet combustion conditions, resulting in a higher evaporation constant. A modified Marangoni number was derived in order to represent the surface force characteristics. The results at different pressure conditions indicated that the nonmonotonic response of the evaporation rate to pressure may also be attributed to the Marangoni effect.

  1. New industrial heat pump applications to cheese production

    SciTech Connect

    Not Available

    1990-04-01

    A energy cost reduction of the Sorrento Cheese Co. Inc. cheese/whey powder process has been completed. Of Particular interest were the opportunities for utilizing heat pumps for energy cost reduction or other profit improving uses. Pinch Technology was used to identify heat recovery, heat pumping, process modification and congeneration options. Pinch Technology provides a thermodynamically consistent base from which the relative merits of competing cost reduction options can be assessed. The study identified heat recovery opportunities which could save $198,000/yr at an over all payback of 26 months. Individual project paybacks range from 18 to 36 months. The use of heat pumps in the form of MVR and TVR evaporators is well established in the dairy industry. For this process, which already incorporates a TVR evaporator, no additional cost effective opportunities for utilizing heat pumps were identified. It is felt that the results obtained in this study are applicable to other cheese/whey powder manufacturing sits. This study, and others, indicate that reductions in thermal energy consumption of 10--15% can be expected. Also the use of MVR and TVR evaporators is appropriate. 10 figs., 1 tab.

  2. Improved measurement of low residual stresses by speckle correlation interferometry and local heat treating

    SciTech Connect

    Pechersky, M.J.

    2000-02-23

    The results presented in this paper clearly demonstrate that the dynamic range of this measurement technique can be improved substantially over the earlier experiments. It is just as clear that a more systematic study must be performed to quantify these improvements and to generate usable calibrations. These results are also encouraging in the sense that this technique may now be appropriate for other materials with high thermal diffusivities. Previous attempts to measure residual stresses by laser annealing and electronic speckle pattern interferometry have been successful for moderate to high stress levels. The method uses an infrared laser for relieving stress in a small spot. A dab on temperature indicating paint is applied to the spot and a specklegram of the spot and the surrounding area is captured. The paint is then heated with a laser until it melts. The heat is transferred from the paint into the metal resulting in a small amount of localized stress relief as the yield stress of the material drops below the stress levels surrounding the spot. Once the spot and area around it have cooled a second speckle-gram is captured and the images are processed to determine the in-plane strain. The amount of stress relief depends on the melting temperature of the paint since yield stress is a function of temperature. The measurement of local stress relief by heating is subject to limitations that result from thermal expansion competing with the reduction in yield stress of the spot at the elevated temperature. That is, as the spot is heated it tends to temporarily reduce the stress in the region surrounding the spot as it expands into this surrounding region. This limits the amount of stress relief that can occur. This can be overcome to some extent by using higher temperature paints, which in turn lowers the yield stress in the heated spot. At some point, however, the thermal expansion overtakes the surrounding stress field and can even drive it into compression. Furthermore, for tension levels on the order of eighty percent or less of the yield stress, the sub-micrometer deformations result in less than a single fringe. The strains indicated by such sub-fringes are comparable to noise levels that occur from air turbulence, environmental thermal variations and so forth. Thus, for both fundamental and practical reasons the technique was modified to increase the fringe count at lower stress levels. The authors have successfully performed two separate experiments to raise the fringe count. One method was simply to start observing the fringes (or strains) immediately after annealing. Not only can several fringes be obtained in this way but a clear relationship has been observed with the stress levels. The other approach was to cool an area surrounding the region of interest and then observe the net strain after thermal equilibrium is reestablished. Both methods have shown the ability to handle lower tension levels than were measurable by the earlier procedure.

  3. Effect of heating system using a geothermal heat pump on the production performance and housing environment of broiler chickens.

    PubMed

    Choi, H C; Salim, H M; Akter, N; Na, J C; Kang, H K; Kim, M J; Kim, D W; Bang, H T; Chae, H S; Suh, O S

    2012-02-01

    A geothermal heat pump (GHP) is a potential heat source for the economic heating of broiler houses with optimum production performance. An investigation was conducted to evaluate the effect of a heating system using a GHP on production performance and housing environment of broiler chickens. A comparative analysis was also performed between the GHP system and a conventional heating system that used diesel for fuel. In total, 34,000 one-day-old straight run broiler chicks were assigned to 2 broiler houses with 5 replicates in each (3,400 birds/replicate pen) for 35 d. Oxygen(,) CO(2), and NH(3) concentrations in the broiler house, energy consumption and cost of heating, and production performance of broilers were evaluated. Results showed that the final BW gain significantly (P < 0.05) increased when chicks were reared in the GHP broiler house compared with that of chicks reared in the conventional broiler house (1.73 vs. 1.62 kg/bird). The heating system did not affect the mortality of chicks during the first 4 wk of the experimental period, but the mortality markedly increased in the conventional broiler house during the last wk of the experiment. Oxygen content in the broiler house during the experimental period was not affected by the heating system, but the CO(2) and NH(3) contents significantly increased (P < 0.05) in the conventional broiler house compared with those in the GHP house. Fuel consumption was significantly reduced (P < 0.05) and electricity consumption significantly increased (P < 0.05) in the GHP house compared with the consumption in the conventional house during the experiment. The total energy cost of heating the GHP house was significantly lower (P < 0.05) compared with that of the conventional house. It is concluded that a GHP system could increase the production performance of broiler chicks due to increased inside air quality of the broiler house. The GHP system had lower CO(2) and NH(3) emissions with lower energy cost than the conventional heating system for broiler chickens. PMID:22252338

  4. Geoneutrinos and Heat Production in the Earth: Constraints and Implications

    ScienceCinema

    McDonough, Bill [University of Maryland, College Park, Maryland, United States

    2010-01-08

    Recent results from antineutrino (geoneutrino) studies at KamLAND are coincident with geochemical models of Th and U in the Earth.  KamLAND and Borexino detectors are on line, thus uncertainties in counting statistics will be reduced as data are accumulated.  The SNO+ detector, situated in the middle of the North American plate will come on line in ~3 yrs and will be best suited to yield a precise estimate of the continental contribution to the Earth?s Th & U budget.  The distribution of heat producing elements in the Earth drives convection and plate tectonics.  Geochemical models posit that ~40% of the heat producing elements are in the continental crust, with the remainder in the mantle.  Although models of core formation allow for the incorporation of heat producing elements, the core contribution of radiogenic heating is considered to be negligible.  Most parameterized convection models for the Earth require significant amounts of radiogenic heating of the Earth, a factor of two greater than geochemical models predict.  The initial KamLAND results challenge these geophysical models and support geochemical models calling for a significant contribution from secular cooling of the mantle.

  5. Geoneutrinos and Heat Production in the Earth: Constraints and Implications

    SciTech Connect

    McConough, Bill

    2008-07-02

    Recent results from antineutrino (geoneutrino) studies at KamLAND are coincident with geochemical models of Th and U in the Earth. KamLAND and Borexino detectors are on line, thus uncertainties in counting statistics will be reduced as data are accumulated. The SNO+ detector, situated in the middle of the North American plate will come on line in {approx}3 yrs and will be best suited to yield a precise estimate of the continental contribution to the Earth's Th & U budget. The distribution of heat producing elements in the Earth drives convection and plate tectonics. Geochemical models posit that {approx}40% of the heat producing elements are in the continental crust, with the remainder in the mantle. Although models of core formation allow for the incorporation of heat producing elements, the core contribution of radiogenic heating is considered to be negligible. Most parameterized convection models for the Earth require significant amounts of radiogenic heating of the Earth, a factor of two greater than geochemical models predict. The initial KamLAND results challenge these geophysical models and support geochemical models calling for a significant contribution from secular cooling of the mantle.

  6. Geoneutrinos and Heat Production in the Earth: Constraints and Implications

    SciTech Connect

    McDonough, Bill

    2008-07-02

    Recent results from antineutrino (geoneutrino) studies at KamLAND are coincident with geochemical models of Th and U in the Earth.  KamLAND and Borexino detectors are on line, thus uncertainties in counting statistics will be reduced as data are accumulated.  The SNO+ detector, situated in the middle of the North American plate will come on line in ~3 yrs and will be best suited to yield a precise estimate of the continental contribution to the Earth’s Th & U budget.  The distribution of heat producing elements in the Earth drives convection and plate tectonics.  Geochemical models posit that ~40% of the heat producing elements are in the continental crust, with the remainder in the mantle.  Although models of core formation allow for the incorporation of heat producing elements, the core contribution of radiogenic heating is considered to be negligible.  Most parameterized convection models for the Earth require significant amounts of radiogenic heating of the Earth, a factor of two greater than geochemical models predict.  The initial KamLAND results challenge these geophysical models and support geochemical models calling for a significant contribution from secular cooling of the mantle.

  7. Local sweating on the forehead, but not forearm, is influenced by aerobic fitness independently of heat balance requirements during exercise.

    PubMed

    Cramer, Matthew N; Bain, Anthony R; Jay, Ollie

    2012-05-01

    The present study investigated the influence of maximal oxygen uptake (V(O2 max)) on local steady-state sudomotor responses to exercise, independently of evaporative requirements for heat balance (E(req)). Eleven fit (F; (V(O2 max))61.9 6.0 ml kg(-1) min(-1)) and 10 unfit men (UF; (V(O2 max)) 40.4 3.8 ml kg(-1) min(-1)) cycled for 60 min at an air temperature of 24.5 0.8C and ambient humidity of 0.9 0.3 kPa at a set metabolic heat production per unit surface area, producing the same E(req) in all participants (BAL trial) and, in a second trial, at 60% of (V(O2 max)). During the BAL trial, absolute power (F 107 2 and UF 102 2 W; P = 0.126), E(req) (F 175 5 and UF 176 9 W m(-2); P = 0.855), steady-state whole-body sweat rate (F 0.44 0.02 and UF 0.47 0.02 mg cm(-2) min(-1); P = 0.385) and local sweat rate on the arm (F 0.29 0.03 and UF 0.35 0.03 mg cm(-2) min(-1); P = 0.129) were not different between groups; however, local sweat rate on the forehead in UF (1.67 0.20 mg cm(-2) min(-1)) was almost double (P = 0.002) that of F (0.87 0.11 mg cm(-2) min(-1)). Heart rate, ratings of perceived exertion and relative exercise intensity were also significantly greater in UF (P < 0.05). There was a trend towards an elevated minute ventilation in UF (P = 0.052), while end-tidal P(CO2) was significantly lower in UF (P = 0.028). At 60% (V(O2 max)), absolute power (F 174 6 and UF 110 5 W; P < 0.001), E(req) (F 291 14 and UF 190 17 W m(-2); P < 0.001), steady-state whole-body sweat rate (F 0.84 0.05 and UF 0.53 0.03 mg cm(-2) min(-1); P < 0.001) and local sweat rate on the arm (F 0.75 0.04 and UF 0.35 0.03 mg cm(-2) min(-1); P < 0.001) and on the forehead (F 2.92 0.42 and UF 1.68 0.23 mg cm(-2) min(-1); P = 0.022) were all significantly greater in F compared with UF. Heart rate and ratings of perceived exertion were similar at all time points (P > 0.05). Significantly greater minute ventilation (P < 0.001) and end-tidal P (CO2) responses (P = 0.017) were found in F. In conclusion, aerobic fitness alters local sweating on the forehead, but not the forearm, independently of evaporative requirements for heat balance, and may be the result of differential control of sweating in these skin areas associated with the relative intensity of exercise. PMID:22227199

  8. District heating from electric-generating plants and municipal incinerators: Local planners assessment guide

    NASA Astrophysics Data System (ADS)

    Pferdehirt, W.; Kron, N., Jr.

    1980-11-01

    The preliminary evaluation of the feasibility of district heating using heat recovered from electric generating plants and municipal incinerators is outlined. System feasibility is indicated by: (1) the existence of an adequate supply of nearby waste heat,(2) the presence of a sufficiently dense and large thermal load, and (3) a favorable cost comparison with conventional heating methods.

  9. The role of size polydispersity in magnetic fluid hyperthermia: average vs. local infra/over-heating effects.

    PubMed

    Munoz-Menendez, Cristina; Conde-Leboran, Ivan; Baldomir, Daniel; Chubykalo-Fesenko, Oksana; Serantes, David

    2015-11-01

    An efficient and safe hyperthermia cancer treatment requires the accurate control of the heating performance of magnetic nanoparticles, which is directly related to their size. However, in any particle system the existence of some size polydispersity is experimentally unavoidable, which results in a different local heating output and consequently a different hyperthermia performance depending on the size of each particle. With the aim to shed some light on this significant issue, we have used a Monte Carlo technique to study the role of size polydispersity in heat dissipation at both the local (single particle) and global (macroscopic average) levels. We have systematically varied size polydispersity, temperature and interparticle dipolar interaction conditions, and evaluated local heating as a function of these parameters. Our results provide a simple guide on how to choose, for a given polydispersity degree, the more adequate average particle size so that the local variation in the released heat is kept within some limits that correspond to safety boundaries for the average-system hyperthermia performance. All together we believe that our results may help in the design of more effective magnetic hyperthermia applications. PMID:26437746

  10. Localized heating of electrons in ionization zones: Going beyond the Penning-Thornton paradigm in magnetron sputtering

    SciTech Connect

    Anders, André

    2014-12-15

    The fundamental question of how energy is supplied to a magnetron discharge is commonly answered by the Penning-Thornton paradigm invoking secondary electrons. Recently, Huo and coworkers (Plasma Sources Sci. Technol. 22, 045005 (2013)) used a global discharge model to show that electron heating in the electric field of the magnetic presheath is dominant over heating by secondary electrons. In this contribution, this concept is applied locally taking into account the electric potential structure of ionization zones. Images of ionization zones can and should be interpreted as diagrams of the localization of high electric potential and related electron energy.

  11. Local heat and cold application after eastern cottonmouth moccasin (Agkistrodon piscivorus) envenomation in the rat: effect on tissue injury.

    PubMed

    Cohen, W R; Wetzel, W; Kadish, A

    1992-11-01

    We studied the effect of local application of heat or cold on the development of tissue necrosis in envenomated rats. Anesthetized animals had 6 mg/kg venom from Agkistrodon piscivorus injected subcutaneously into the lateral aspect of a hind limb. Heat or cold was applied to the site of envenomation in the experimental groups for 4-6 hr, and the injected area was examined histologically after 24 hr. Neither local treatment, with or without the presence of systemic antivenin, significantly affected the severity of tissue necrosis induced by the venom in comparison to a control group left at ambient temperature. PMID:1485335

  12. Local Self-Heating of Pyrolyzed Polymer Microstructure for Further Carbonization at Higher Temperature on Silicon Chip

    NASA Astrophysics Data System (ADS)

    Naka, Keisuke; Okamoto, Kanji; Konishi, Satoshi

    2008-12-01

    In this paper, we present the local self-heating of a pyrolyzed polymer microstructure on a silicon substrate by resistive heating for further carbonization at higher temperature. It becomes difficult to pyrolyze polymers on substrates above 1100 C because the substrates or other materials are thermally damaged. In order to address this restriction, we propose a multistep pyrolysis. A patterned polymer structure is converted to a conductive pyrolyzed polymer by a furnace process at low temperature. The pyrolyzed polymer structure carbonizes itself by resistive heating as the final process. We have successfully demonstrated the proposed method. The obtained material was characterized by electrical resistance measurement and Raman microspectroscopy.

  13. Local heat stroke prevention plans in Japan: characteristics and elements for public health adaptation to climate change.

    PubMed

    Martinez, Gerardo Sanchez; Imai, Chisato; Masumo, Kanako

    2011-12-01

    The adverse health effects from hot weather and heat waves represent significant public health risks in vulnerable areas worldwide. Rising temperatures due to climate change are aggravating these risks in a context of fast urbanization, population growth and societal ageing. However, environmental heat-related health effects are largely preventable through adequate preparedness and responses. Public health adaptation to climate change will often require the implementation of heat wave warning systems and targeted preventive activities at different levels. While several national governments have established such systems at the country level, municipalities do not generally play a major role in the prevention of heat disorders. This paper analyzes selected examples of locally operated heat-health prevention plans in Japan. The analysis of these plans highlights their strengths, but also the need of local institutions for assistance to make the transition towards an effective public health management of high temperatures and heat waves. It can also provide useful elements for municipal governments in vulnerable areas, both in planning their climate change and health adaptation activities or to better protect their communities against current health effects from heat. PMID:22408589

  14. Local Heat Stroke Prevention Plans in Japan: Characteristics and Elements for Public Health Adaptation to Climate Change

    PubMed Central

    Martinez, Gerardo Sanchez; Imai, Chisato; Masumo, Kanako

    2011-01-01

    The adverse health effects from hot weather and heat waves represent significant public health risks in vulnerable areas worldwide. Rising temperatures due to climate change are aggravating these risks in a context of fast urbanization, population growth and societal ageing. However, environmental heat-related health effects are largely preventable through adequate preparedness and responses. Public health adaptation to climate change will often require the implementation of heat wave warning systems and targeted preventive activities at different levels. While several national governments have established such systems at the country level, municipalities do not generally play a major role in the prevention of heat disorders. This paper analyzes selected examples of locally operated heat-health prevention plans in Japan. The analysis of these plans highlights their strengths, but also the need of local institutions for assistance to make the transition towards an effective public health management of high temperatures and heat waves. It can also provide useful elements for municipal governments in vulnerable areas, both in planning their climate change and health adaptation activities or to better protect their communities against current health effects from heat. PMID:22408589

  15. Chloroplast small heat shock proteins: evidence for atypical evolution of an organelle-localized protein.

    PubMed

    Waters, E R; Vierling, E

    1999-12-01

    Knowledge of the origin and evolution of gene families is critical to our understanding of the evolution of protein function. To gain a detailed understanding of the evolution of the small heat shock proteins (sHSPs) in plants, we have examined the evolutionary history of the chloroplast (CP)-localized sHSPs. Previously, these nuclear-encoded CP proteins had been identified only from angiosperms. This study reveals the presence of the CP sHSPs in a moss, Funaria hygrometrica. Two clones for CP sHSPs were isolated from a F. hygrometrica heat shock cDNA library that represent two distinct CP sHSP genes. Our analysis of the CP sHSPs reveals unexpected evolutionary relationships and patterns of sequence conservation. Phylogenetic analysis of the CP sHSPs with other plant CP sHSPs and eukaryotic, archaeal, and bacterial sHSPs shows that the CP sHSPs are not closely related to the cyanobacterial sHSPs. Thus, they most likely evolved via gene duplication from a nuclear-encoded cytosolic sHSP and not via gene transfer from the CP endosymbiont. Previous sequence analysis had shown that all angiosperm CP sHSPs possess a methionine-rich region in the N-terminal domain. The primary sequence of this region is not highly conserved in the F. hygrometrica CP sHSPs. This lack of sequence conservation indicates that sometime in land plant evolution, after the divergence of mosses from the common ancestor of angiosperms but before the monocot-dicot divergence, there was a change in the selective constraints acting on the CP sHSPs. PMID:10588716

  16. Chloroplast small heat shock proteins: Evidence for atypical evolution of an organelle-localized protein

    PubMed Central

    Waters, Elizabeth R.; Vierling, Elizabeth

    1999-01-01

    Knowledge of the origin and evolution of gene families is critical to our understanding of the evolution of protein function. To gain a detailed understanding of the evolution of the small heat shock proteins (sHSPs) in plants, we have examined the evolutionary history of the chloroplast (CP)-localized sHSPs. Previously, these nuclear-encoded CP proteins had been identified only from angiosperms. This study reveals the presence of the CP sHSPs in a moss, Funaria hygrometrica. Two clones for CP sHSPs were isolated from a F. hygrometrica heat shock cDNA library that represent two distinct CP sHSP genes. Our analysis of the CP sHSPs reveals unexpected evolutionary relationships and patterns of sequence conservation. Phylogenetic analysis of the CP sHSPs with other plant CP sHSPs and eukaryotic, archaeal, and bacterial sHSPs shows that the CP sHSPs are not closely related to the cyanobacterial sHSPs. Thus, they most likely evolved via gene duplication from a nuclear-encoded cytosolic sHSP and not via gene transfer from the CP endosymbiont. Previous sequence analysis had shown that all angiosperm CP sHSPs possess a methionine-rich region in the N-terminal domain. The primary sequence of this region is not highly conserved in the F. hygrometrica CP sHSPs. This lack of sequence conservation indicates that sometime in land plant evolution, after the divergence of mosses from the common ancestor of angiosperms but before the monocot–dicot divergence, there was a change in the selective constraints acting on the CP sHSPs. PMID:10588716

  17. Profile shape optimization in multi-jet impingement cooling of dimpled topologies for local heat transfer enhancement

    NASA Astrophysics Data System (ADS)

    Negi, Deepchand Singh; Pattamatta, Arvind

    2014-08-01

    The present study deals with shape optimization of dimples on the target surface in multi-jet impingement heat transfer. Bezier polynomial formulation is incorporated to generate profile shapes for the dimple profile generation and a multi-objective optimization is performed. The optimized dimple shape exhibits higher local Nusselt number values compared to the reference hemispherical dimpled plate optimized shape which can be used to alleviate local temperature hot spots on target surface.

  18. Profile shape optimization in multi-jet impingement cooling of dimpled topologies for local heat transfer enhancement

    NASA Astrophysics Data System (ADS)

    Negi, Deepchand Singh; Pattamatta, Arvind

    2015-04-01

    The present study deals with shape optimization of dimples on the target surface in multi-jet impingement heat transfer. Bezier polynomial formulation is incorporated to generate profile shapes for the dimple profile generation and a multi-objective optimization is performed. The optimized dimple shape exhibits higher local Nusselt number values compared to the reference hemispherical dimpled plate optimized shape which can be used to alleviate local temperature hot spots on target surface.

  19. The interrealtionship between locally applied heat, ageing and skin blood flow on heat transfer into and from the skin.

    PubMed

    Petrofsky, Jerrold; Alshahmmari, Faris; Yim, Jong Eun; Hamdan, Adel; Lee, Haneul; Neupane, Sushma; Shetye, Gauri; Moniz, Harold; Chen, Wei-Ti; Cho, Sungkwan; Pathak, Kunal; Malthane, Swapnil; Shenoy, Samruddha; Somanaboina, Karunakar; Alshaharani, Mastour; Nevgi, Bhakti; Dave, Bhargav; Desai, Rajavi

    2011-07-01

    In response to a thermal stress, skin blood flow (BF) increases to protect the skin from damage. When a very warm, noxious, heat source (44 C) is applied to the skin, the BF increases disproportionately faster than the heat stress that was applied, creating a safety mechanism for protecting the skin. In the present investigation, the rate of rise of BF in response to applied heat at temperatures between 32 C and 40 C was examined as well as the thermal transfer to and from the skin with and without BF in younger and older subjects to see how the skin responds to a non-noxious heat source. Twenty male and female subjects (10 - 20-35 years, 10 - 40-70 years) were examined. The arms of the subjects were passively heated for 6 min with and without vascular occlusion by a thermode at temperatures of 32, 36, 38 or 40 C. When occlusion was not used during the 6 min exposure to heat, there was an exponential rise in skin temperature and BF in both groups of subjects over the 6-min period. However, the older subjects achieved similar skin temperatures but with the expenditure of fewer calories from the thermode than was seen for the younger subjects (p<0.05). BF was significantly less in the older group than the younger group at rest and after exposure to each of the three warmest thermode temperatures (p<0.05). As was seen for noxious temperatures, after a delay, the rate of rise of BF at the three warmest thermode temperatures was faster than the rise in skin temperature in the younger group but less in the older group of subjects. Thus, a consequence of ageing is reduced excess BF in response to thermal stress increasing susceptibility to thermal damage. This must be considered in modelling of BF. PMID:21605003

  20. Heat Shock Protein 90 Regulates Subcellular Localization of Smads in Mv1Lu Cells.

    PubMed

    Lee, Jeeyong; An, You Sun; Kim, Mi-Ra; Kim, Ye-Ah; Lee, Jin Kyung; Hwang, Chang Sun; Chung, Eunkyung; Park, In-Chul; Yi, Jae Youn

    2016-01-01

    Heat shock protein 90 (HSP90) regulates the stability of various proteins and plays an essential role in cellular homeostasis. Many client proteins of HSP90 are involved in cell growth, survival, and migration; processes that are generally accepted as participants in tumorigenesis. HSP90 is also up-regulated in certain tumors. Indeed, the inhibition of HSP90 is known to be effective in cancer treatment. Recently, studies showed that HSP90 regulates transforming growth factor ?1 (TGF-?1)-induced transcription by increasing the stability of the TGF-? receptor. TGF-? signaling also has been implicated in cancer, suggesting the possibility that TGF-?1 and HSP90 function cooperatively during the cancer cell progression. Here in this paper, we investigated the role of HSP90 in TGF-?1-stimulated Mv1Lu cells. Treatment of Mv1Lu cells with the HSP90 inhibitor, 17-allylamino-demethoxy-geldanamycin (17AAG), or transfection with truncated HSP90 (?HSP90) significantly reduced TGF-?1-induced cell migration. Pretreatment with 17AAG or transfection with ?HSP90 also reduced the levels of phosphorylated Smad2 and Smad3. In addition, the HSP90 inhibition interfered the nuclear localization of Smads induced by constitutively active Smad2 (S2EE) or Smad3 (S3EE). We also found that the HSP90 inhibition decreased the protein level of importin-?1 which is known to regulate R-Smad nuclear translocation. These data clearly demonstrate a novel function of HSP90; HSP90 modulates TGF-? signaling by regulating Smads localization. Overall, our data could provide a detailed mechanism linking HSP90 and TGF-? signaling. The extension of our understanding of HSP90 would offer a better strategy for treating cancer. J. Cell. Biochem. 117: 230-238, 2016. 2015 Wiley Periodicals, Inc. PMID:26104915

  1. Heat losses in a CVD reactor for polysilicon production: Comprehensive model and experimental validation

    NASA Astrophysics Data System (ADS)

    Ramos, A.; Rodríguez, A.; del Cañizo, C.; Valdehita, J.; Zamorano, J. C.; Luque, A.

    2014-09-01

    This work addresses heat losses in a CVD reactor for polysilicon production. Contributions to the energy consumption of the so-called Siemens process are evaluated, and a comprehensive model for heat loss is presented. A previously-developed model for radiative heat loss is combined with conductive heat loss theory and a new model for convective heat loss. Theoretical calculations are developed and theoretical energy consumption of the polysilicon deposition process is obtained. The model is validated by comparison with experimental results obtained using a laboratory-scale CVD reactor. Finally, the model is used to calculate heat consumption in a 36-rod industrial reactor; the energy consumption due to convective heat loss per kilogram of polysilicon produced is calculated to be 22-30 kWh/kg along a deposition process.

  2. Polymer dispersed liquid crystals: effects of photorefractivity and local heating on holographic recording

    NASA Astrophysics Data System (ADS)

    Simoni, F.; Cipparrone, G.; Mazzulla, A.; Pagliusi, P.

    1999-07-01

    We report a detailed investigation of the photorefractive origin of permanent orientational gratings recorded by holographic technique in dye-doped polymer-dispersed liquid crystal (PDLC) films. This investigation was performed using wave-mixing characterization by two beam coupling (TBC) experiments. We determined the TBC gain by means of asymmetric energy transfer measurements and the phase shift by TBC translation technique measurements. The photorefractive origin of the effect were proved by the experimental results. Nevertheless, some peculiarities showed the presence of other mechanisms that combined with the photorefractivity to give the observed storage effect. The long time stability and some characteristic of the recorded structure have been explained as a thermal fixing of the grating. During the writing process, due to the strong light absorption, the sample was locally heated; under these conditions, the space charge field effect can modify the droplets interfaces and consequently the orientation of liquid crystal inside the droplets. After removing the two writing beams, the new configuration was frozen.

  3. Simulation Study of Toroidal Flow Generation of Minority Ions by Local ICRF Heating

    NASA Astrophysics Data System (ADS)

    Murakami, Sadayoshi; Itoh, Kimitaka; Zheng, Linjin; Van Dam, James W.; Fukuyama, Atsushi

    2015-12-01

    The toroidal flow generation of minority ions by the local ion cyclotron range of frequencies (ICRF) heating is investigated in a tokamak plasma by applying the GNET code, which can solve the drift kinetic equation in the 5-D phase space. An asymmetry of velocity distribution function in the parallel direction is found and two types of toroidal averaged flow of minority ions are observed. One is the sheared flow near the RF power absorption region depending on the sign of k||, and the other is the toroidal flow, which is larger than the previous one, independent of the sign of k||. It is found that the k||-sign-independent toroidal flow is generated by the net toroidal motion of energetic tail ions and that the k||-sign-dependent flow is related to the mechanism proposed by Ohkawa [Phys. Plasmas 12, 094506 (2005)].

  4. Optimization of a localized surface plasmon resonance biosensor for heat shock protein 70

    NASA Astrophysics Data System (ADS)

    Denomme, R. C.; Young, Z.; Brock, L.; Nieva, P. M.; Vijayan, M. M.

    2012-03-01

    Localized surface plasmon resonance, a property characteristic of metal nanoparticles, is a promising technique for the development of low cost, rapid, and portable biosensors for a variety of medical diagnostic applications. In order to meet the demanding detection limits required for many such applications, performance improvements are required. Designing nanoparticle structures to maximize refractive index sensitivity and optimize the electromagnetic field decay length is one approach to achieving better performance. However, experimentally finding the optimal nanoparticle structure, as has been done in the past, is time consuming and costly, and needs to be done for each biomolecule of interest. Instead, simulations can be used to find the optimal nanoparticle design prior to fabrication. In this paper, we present a numerical modeling technique that allows the design of optimal nanoparticles for LSPR biosensors, and report on the effect of the size and shape of gold nanoparticles on the sensitivity and decay length. The results are used to determine the optimal nanoparticle geometry for an LSPR immunosensor for heat shock protein 70, an important protein with applications in medical and wildlife diagnostics. Our simulations show an improvement of 373% in sensor response when using the optimal configuration, showcasing the significant advantages of proper nanoparticle design.

  5. Stably maintained microdomain of localized unrestrained supercoiling at a Drosophila heat shock gene locus.

    PubMed Central

    Jupe, E R; Sinden, R R; Cartwright, I L

    1993-01-01

    A psoralen crosslinking assay was utilized to detect localized, unrestrained DNA supercoiling (torsional tension) in vivo in Drosophila chromosomal regions subject to differential transcriptional activity. By comparing rates of crosslinking in intact cells with those in cells where potential tension in chromosomal domains was relaxed by DNA strand nicking, the contribution to psoralen accessibility caused by altered DNA-protein interactions (e.g. nucleosomal perturbations) was distinguished from that due to the presence of unrestrained supercoiling in a region of interest. The heat shock protein 70 (hsp70) genes were wound with a significant level of superhelical tension that remained virtually unaltered whether or not the genes were transcriptionally activated by thermal elevation. Constitutively expressed 18S ribosomal RNA genes also exhibited unrestrained superhelical tension at a level comparable with that across hsp70. In contrast, flanking regions downstream of each of the divergent hsp70 genes at locus 87A7 exhibited substantially less tension. Thus the results point to the existence of stable, torsionally stressed topological domains within eukaryotic chromosomal DNA, suggesting that the relaxing action of topoisomerases is not ubiquitous throughout the nucleus but, in fact, is likely to be tightly regulated. Images PMID:8458324

  6. Heat Shock Transcription Factor 1 Localizes to Sex Chromatin during Meiotic Repression*

    PubMed Central

    kerfelt, Malin; Vihervaara, Anniina; Laiho, Asta; Conter, Annie; Christians, Elisabeth S.; Sistonen, Lea; Henriksson, Eva

    2010-01-01

    Heat shock factor 1 (HSF1) is an important transcription factor in cellular stress responses, cancer, aging, and developmental processes including gametogenesis. Disruption of Hsf1, together with another HSF family member, Hsf2, causes male sterility and complete lack of mature sperm in mice, but the specific role of HSF1 in spermatogenesis has remained unclear. Here, we show that HSF1 is transiently expressed in meiotic spermatocytes and haploid round spermatids in mouse testis. The Hsf1?/? male mice displayed regions of seminiferous tubules containing only spermatogonia and increased morphological abnormalities in sperm heads. In search for HSF1 target genes, we identified 742 putative promoters in mouse testis. Among them, the sex chromosomal multicopy genes that are expressed in postmeiotic cells were occupied by HSF1. Given that the sex chromatin mostly is repressed during and after meiosis, it is remarkable that HSF1 directly regulates the transcription of sex-linked multicopy genes during postmeiotic repression. In addition, our results show that HSF1 localizes to the sex body prior to the meiotic divisions and to the sex chromocenter after completed meiosis. To the best of our knowledge, HSF1 is the first known transcription factor found at the repressed sex chromatin during meiosis. PMID:20802198

  7. A mathematical model for 2D heat transfer dynamics in fluid systems with localized sink of magmatic fluid into local fractured zones above the top of crystallizing intrusions

    NASA Astrophysics Data System (ADS)

    Sharapov, V. N.; Cherepanov, A. N.; Popov, V. N.; Bykova, V. G.

    2012-11-01

    A model describing two-dimensional (2D) dynamics of heat transfer in the fluid systems with a localized sink of a magmatic fluid into local fractured zones above the roof of crystallizing crustal intrusions is suggested. Numerical modeling of the migration of the phase boundaries in 2D intrusive chambers under retrograde boiling of magma with relatively high initial water content in the melt shows that, depending on the character of heat dissipation from a magmatic fluid into the host rock, two types of fluid magmatic systems can arise. (1) At high heat losses, the zoning of fluidogenic ore formation is determined by the changes in temperature of the rocks within the contact aureole of the intrusive bodies. These temperature variations are controlled by the migration of the phase boundaries in the cooling melt towards the center of the magmatic bodies from their contacts. (2) In the case of a localized sink of the magmatic fluid in different parts of the top of the intrusive chambers, a specific characteristic scenario of cooling of the magmatic bodies is probably implemented. In 2D systems with a heat transfer coefficient ? k < 5 104 W/m2 K, an area with quasi-stationary phase boundaries develops close to the region of fluid drainage through the fractured zone in the intrusion. Therefore, as the phase boundaries contract to the sink zone of a fluid, specific thermal tubes arise, whose characteristics depend on the width of the fluid-conductive zone and the heat losses into the side rocks. (3) The time required for the intrusion to solidify varies depending on the particular position of the fluid conductor above the top of the magmatic body.

  8. Crustal Heat Production and the Thermal Evolution of Mars. Revision

    NASA Technical Reports Server (NTRS)

    McLennan, Scott M.

    2001-01-01

    The chemical compositions of soils and rocks from the Pathfinder site and Phobos-2 orbital gamma-ray spectroscopy indicate that the Martian crust has a bulk composition equivalent to large-ion lithophile (LIL) and heat-producing element (HPE) enriched basalt, with a potassium content of about 0.5%. A variety of radiogenic isotopic data also suggest that separation of LIL-enriched crustal and depleted mantle reservoirs took place very early in Martian history (greater than 4.0 Ga). Accordingly, if the enriched Martian crust is greater than 30km thick it is likely that a large fraction (up to at least 50%) of the heat-producing elements in Mars was transferred into the crust very early in the planet's history. This would greatly diminish the possibility of early widespread melting of the Martian mantle.

  9. Crustal Heat Production and the Thermal Evolution of Mars

    NASA Technical Reports Server (NTRS)

    McLennan, Scott M.

    2001-01-01

    The chemical composition of soils and rocks from the Pathfinder site and Phobos-2 orbital gamma-ray spectroscopy indicate that the Martian crust has a bulk composition equivalent to large-ion lithophile (LIL) and heat-producing element (K, Th, U) enriched basalt, with a potassium content of about 0.5%. A variety of radiogenic isotope data also suggest that separation of LIL-enriched crust and depleted mantle reservoirs took place very early in Martian history (>4.0 Ga). Accordingly, if the enriched Martian crust is >30 km thick it is likely that a large fraction (up to at least 50%) of the heat-producing elements in Mars was transferred into the crust very early in the planet's history. This would greatly diminish the possibility of early widespread melting of the Martian mantle.

  10. Genetic variations alter production and behavioral responses following heat stress in two strains of laying hens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Heat stress is a problem for both egg production and hen well-being. Given a stressor, genetic differences alter the type and degree of hens’ responses and their adaptation. This study examined heat stress responses of two strains of White Leghorns: Dekalb XL (DXL), a commercial strain individually ...

  11. Performance evaluation of adding ethanol production into an existing combined heat and power plant.

    PubMed

    Starfelt, F; Thorin, E; Dotzauer, E; Yan, J

    2010-01-01

    In this paper, the configuration and performance of a polygeneration system are studied by modelling the integration of a lignocellulosic wood-to-ethanol process with an existing combined heat and power (CHP) plant. Data from actual plants are applied to validate the simulation models. The integrated polygeneration system reaches a total efficiency of 50%, meeting the heating load in the district heating system. Excess heat from the ethanol production plant supplies 7.9 MW to the district heating system, accounting for 17.5% of the heat supply at full heating load. The simulation results show that the production of ethanol from woody biomass is more efficient when integrated with a CHP plant compared to a stand-alone production plant. The total biomass consumption is reduced by 13.9% while producing the same amounts of heat, electricity and ethanol fuel as in the stand-alone configurations. The results showed that another feature of the integrated polygeneration system is the longer annual operating period compared to existing cogeneration. Thus, the renewable electricity production is increased by 2.7% per year. PMID:19758800

  12. Virtual Grower: Software to Calculate Heating Costs of Greenhouse Production in the US

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Greenhouses are used in many climates either for season extension or year-round production, and can be expensive to heat. Greenhouse users and growers are often faced with management decisions that rely on an understanding of how temperature settings, heating systems, fuel types, and construction d...

  13. Effects of Heat Stress on Egg Production and Quality in Two Strains of Layers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Heat stress is a problem for both egg production and bird well-being. Given a stressor, genetic differences can alter the type and degree of birds’ responses and their adaptation. This study examined heat stress responses of two strains of White Leghorns: DeKalb XL (DXL), an individually-selected, c...

  14. Wasp Hawking Induces Endothermic Heat Production in Guard Bees

    PubMed Central

    Tan, K.; Li, H.; Yang, M.X.; Hepburn, H.R.; Radloff, S.E.

    2010-01-01

    When vespine wasps, Vespa velutina Lepeletier (Hymenoptera: Vespidae), hawk (capture) bees at their nest entrances alerted and poised guards of Apis cerana cerana F. and Apis mellifera ligustica Spinola (Hymenoptera: Apidae) have average thoracic temperatures slightly above 24 C. Many additional worker bees of A. cerana, but not A. mellifera, are recruited to augment the guard bee cohort and begin wing-shimmering and body-rocking, and the average thoracic temperature rises to 29.8 1.6 C. If the wasps persist hawking, about 30 guard bees of A. cerana that have raised their thoracic temperatures to 31.4 0.9 C strike out at a wasp and form a ball around it. Within about three minutes the core temperature of the heat-balling A. cerana guard bees reaches about 46 C, which is above the lethal limit of the wasps, which are therefore killed. Although guard bees of A. mellifera do not exhibit the serial behavioural and physiological changes of A. cerana, they may also heat-ball hawking wasps. Here, the differences in the sequence of changes in the behaviour and temperature during resting and heat-balling by A. cerana and A. mellifera are reported. PMID:21073346

  15. Wasp hawking induces endothermic heat production in guard bees.

    PubMed

    Tan, K; Li, H; Yang, M X; Hepburn, H R; Radloff, S E

    2010-01-01

    When vespine wasps, Vespa velutina Lepeletier (Hymenoptera: Vespidae), hawk (capture) bees at their nest entrances alerted and poised guards of Apis cerana cerana F. and Apis mellifera ligustica Spinola (Hymenoptera: Apidae) have average thoracic temperatures slightly above 24 C. Many additional worker bees of A. cerana, but not A. mellifera, are recruited to augment the guard bee cohort and begin wing-shimmering and body-rocking, and the average thoracic temperature rises to 29.8 1.6 C. If the wasps persist hawking, about 30 guard bees of A. cerana that have raised their thoracic temperatures to 31.4 0.9 C strike out at a wasp and form a ball around it. Within about three minutes the core temperature of the heat-balling A. cerana guard bees reaches about 46 C, which is above the lethal limit of the wasps, which are therefore killed. Although guard bees of A. mellifera do not exhibit the serial behavioural and physiological changes of A. cerana, they may also heat-ball hawking wasps. Here, the differences in the sequence of changes in the behaviour and temperature during "resting" and "heat-balling" by A. cerana and A. mellifera are reported. PMID:21073346

  16. Increasing bioenergy production on arable land: Does the regional and local climate respond? Germany as a case study

    NASA Astrophysics Data System (ADS)

    Tlle, Merja H.; Gutjahr, Oliver; Busch, Gerald; Thiele, Jan C.

    2014-03-01

    The extent and magnitude of land cover change effect on local and regional future climate during the vegetation period due to different forms of bioenergy plants are quantified for extreme temperatures and energy fluxes. Furthermore, we vary the spatial extent of plant allocation on arable land and simulate alternative availability of transpiration water to mimic both rainfed agriculture and irrigation. We perform climate simulations down to 1 km scale for 1970-1975 C20 and 2070-2075 A1B over Germany with Consortium for Small-Scale Modeling in Climate Mode. Here an impact analysis indicates a strong local influence due to land cover changes. The regional effect is decreased by two thirds of the magnitude of the local-scale impact. The changes are largest locally for irrigated poplar with decreasing maximum temperatures by 1C in summer months and increasing specific humidity by 0.15 g kg-1. The increased evapotranspiration may result in more precipitation. The increase of surface radiative fluxes Rnet due to changes in latent and sensible heat is estimated by 5 W m-2locally. Moreover, increases in the surface latent heat flux cause strong local evaporative cooling in the summer months, whereas the associated regional cooling effect is pronounced by increases in cloud cover. The changes on a regional scale are marginal and not significant. Increasing bioenergy production on arable land may result in local temperature changes but not in substantial regional climate change in Germany. We show the effect of agricultural practices during climate transitions in spring and fall.

  17. Working in Australia's heat: health promotion concerns for health and productivity.

    PubMed

    Singh, Sudhvir; Hanna, Elizabeth G; Kjellstrom, Tord

    2015-06-01

    This exploratory study describes the experiences arising from exposure to extreme summer heat, and the related health protection and promotion issues for working people in Australia. Twenty key informants representing different industry types and occupational groups or activities in Australia provided semi-structured interviews concerning: (i) perceptions of workplace heat exposure in the industry they represented, (ii) reported impacts on health and productivity, as well as (iii) actions taken to reduce exposure or effects of environmental heat exposure. All interviewees reported that excessive heat exposure presents a significant challenge for their industry or activity. People working in physically demanding jobs in temperatures>35°C frequently develop symptoms, and working beyond heat tolerance is common. To avoid potentially dangerous health impacts they must either slow down or change their work habits. Such health-preserving actions result in lost work capacity. Approximately one-third of baseline work productivity can be lost in physically demanding jobs when working at 40°C. Employers and workers consider that heat exposure is a 'natural hazard' in Australia that cannot easily be avoided and so must be accommodated or managed. Among participants in this study, the locus of responsibility for coping with heat lay with the individual, rather than the employer. Heat exposure during Australian summers commonly results in adverse health effects and productivity losses, although quantification studies are lacking. Lack of understanding of the hazardous nature of heat exposure exacerbates the serious risk of heat stress, as entrenched attitudinal barriers hamper amelioration or effective management of this increasing occupational health threat. Educational programmes and workplace heat guidelines are required. Without intervention, climate change in hot countries, such as Australia, can be expected to further exacerbate heat-related burden of disease and loss of productivity in many jobs. In light of projected continued global warming, and associated increase in heat waves, more attention needs to be given to environmental heat as a human health hazard in the Occupational Health and Safety arena. Without adoption of effective heat protective strategies economic output and fitness levels will diminish. Health protection and promotion activities should include strategies to reduce heat exposure, limit exposure duration, ensure access to hydration, and promote acclimatization and fitness programmes, and reorientate attitudes towards working in the heat. PMID:23690144

  18. A rigorous derivation of the bioheat equation for local tissue heat transfer based on a volume averaging theory

    NASA Astrophysics Data System (ADS)

    Nakayama, A.; Sano, Y.; Yoshikawa, K.

    2010-08-01

    A general three-dimensional bioheat equation for local tissue heat transfer has been derived with less assumptions, exploiting a volume averaging theory commonly used in fluid-saturated porous media. The volume averaged energy equations obtained for the arterial blood, venous blood and tissue were combined together to form a single energy equation in terms of the tissue temperature alone. The resulting energy equation turns out to be remarkably simple as we define the effective thermal conductivity tensor, which accounts not only for the countercurrent heat exchange mechanism but also for the thermal dispersion mechanism. The present equation for local tissue heat transfer naturally reduces to the Weinbaum-Jiji equation for the unidirectional case.

  19. Determination of the local heat-transfer characteristics on simulated smooth glaze ice accretions on a NACA 0012 airfoil

    NASA Astrophysics Data System (ADS)

    Pais, M. R.; Singh, S. N.; Zou, L.

    1988-01-01

    Convective local heat-transfer coefficients have been obtained in a subsonic wind tunnel for two ice models, a smooth NACA 0012 airfoil and a 5-min glaze-ice accretion on the same airfoil. Local Nusselt numbers have been obtained at various angles of attack. It is found that, when data from a 5-min glaze ice are compared with those for a smooth airfoil, a strong correlation exists in the local Nusselt numbers based on the distance from the nose tip along the surface. This suggests that smooth airfoil data can be used in the prediction of ice accretion at later stages in time.

  20. An iterative procedure for estimating areally averaged heat flux using planetary boundary layer mixed layer height and locally measured heat flux

    SciTech Connect

    Coulter, R. L.; Gao, W.; Lesht, B. M.

    2000-04-04

    Measurements at the central facility of the Southern Great Plains (SGP) Cloud and Radiation Testbed (CART) are intended to verify, improve, and develop parameterizations in radiative flux models that are subsequently used in General Circulation Models (GCMs). The reliability of this approach depends upon the representativeness of the local measurements at the central facility for the site as a whole or on how these measurements can be interpreted so as to accurately represent increasingly large scales. The variation of surface energy budget terms over the SGP CART site is extremely large. Surface layer measurements of the sensible heat flux (H) often vary by a factor of 2 or more at the CART site (Coulter et al. 1996). The Planetary Boundary Layer (PBL) effectively integrates the local inputs across large scales; because the mixed layer height (h) is principally driven by H, it can, in principal, be used for estimates of surface heat flux over scales on the order of tens of kilometers. By combining measurements of h from radiosondes or radar wind profiles with a one-dimensional model of mixed layer height, they are investigating the ability of diagnosing large-scale heat fluxes. The authors have developed a procedure using the model described by Boers et al. (1984) to investigate the effect of changes in surface sensible heat flux on the mixed layer height. The objective of the study is to invert the sense of the model.

  1. Experimental study and mathematical simulation of the mixed convection in a rectangular area with a local heat source and the heat sink at the external boundaries

    NASA Astrophysics Data System (ADS)

    Maksimov, Vyacheslav I.; Nagornov, Dmitriy A.

    2014-08-01

    The results of the experimental determination of temperatures and numerical simulation of temperature fields in a mixed convection in a rectangular area with a heat-conducting walls at a local energy source on the bottom are presented. For the experimental determination of temperature fields in a mixed convection method of thermocouple measurements was used. Studies were conducted at Reynolds numbers 10 ?Re ? 1500 and Rayleigh 103 ?Ra ? 105. For the verification of obtained experimental data mathematical simulation of mixed convection in the region with the use of a software package Comsol Multiphysics is carried out. A good agreement between the results of experimental determination of the local characteristics of mixed convection in a rectangular volume with a local source of energy and heat-conducting walls with theoretical consequences obtained in the simulation of convective flows using a mathematical package is established. It makes it possible to make a conclusion about the possibility of application for the analysis of flow conditions of viscous heat-conducting gas of experimental procedure based on methods of thermocouple measurements. At the same time the developed approach to the experimental study of mixed convection is applicable in a wide enough range of the main flow parameters and the experimental conditions.

  2. Subcontinental lithosphere reactivation beneath the Hoggar swell (Algeria): Localized deformation, melt channeling and heat advection

    NASA Astrophysics Data System (ADS)

    Kourim, Fatna; Vauchez, Alain; Bodinier, Jean-Louis; Alard, Olivier; Bendaoud, Abderrahmane

    2015-05-01

    In the Tahalgha district (southwestern Hoggar, Algeria), the Cenozoic volcanism has sampled subcontinental mantle beneath two crustal terranes that collided during the Pan-African orogeny: the "Polycyclic Central Hoggar" to the east and the "Western Hoggar" to the west. Two major lithospheric shear zones separate these terranes: the "4°35" and the "4°50" faults. Mantle xenoliths were collected between the two faults and across the 4°35 fault. In addition to a range in equilibrium temperatures and chemical compositions reported elsewhere, the samples show variations in their microstructures and crystallographic preferred orientations. Equilibrium temperatures and geochemical characteristics allow dividing them into low - (LT; 700-900 °C), intermediate - (IT; 900-1000 °C), and high-temperature (HT; 1000-1100 °C) xenoliths. The LT and IT peridotites occur on both sides of the 4°35 fault; they are usually coarse-grained. HT xenoliths are present only east of the 4°35 fault, in the narrow domain stuck between the two faults; they are fine-grained and extensively affected by annealing and melt-rock reactions. Microstructures and crystallographic textures indicate that deformation in the LT- and IT-xenoliths occurred through dislocation creep under relatively high-temperature, low-pressure conditions, followed by post-kinematic cooling. The fine-grained HT-xenoliths were deformed under relatively high-stress conditions before being annealed. Combining microstructural and CPO data with petrological and geochemical informations suggests that: (1) the LT xenoliths are remnants of the Neoproterozoic lithospheric mantle that preserved microstructural and chemical characteristics inherited from the Pan-African orogeny, and (2) the HT xenoliths record localized Cenozoic deformation associated with melt channeling through feed-back processes that culminated in the formation of high-permeability porous-flow conduits. Limited grain-growth in HT xenoliths suggests that advective heating of melt conduits was transient and rapidly followed by thermal relaxation due to conductive heat loss into wall-rock peridotites represented by the IT xenoliths, then by exhumation due to volcanic activity.

  3. Synchronous heating of two local regions of a biological tissue phantom using automated targeting of phase conjugate ultrasound beams

    NASA Astrophysics Data System (ADS)

    Krutyansky, L. M.; Brysev, A. P.; Klopotov, R. V.

    2015-01-01

    Synchronous heating of two local regions of an absorbing medium by phase conjugate ultrasound beams focused on them has been experimentally demonstrated. A polymeric biological tissue phantom with two small air cavities scattering sound has been used as the medium irradiated by a 5-MHz "probe" ultrasound beam. The scattered field is incident on a parametric device for ultrasonic wave phase conjugation. The conjugate and amplified field is self-adaptive focused on scatterers and heats the medium owing to the absorption of the ultrasonic energy. In this case, these regions are heated by about 5C in 70 s. Only an insignificant increase in the temperature owing to the heat conduction effect is observed in the remaining volume of the phantom. The implemented effect can be used in medical applications of phase conjugate ultrasound beams.

  4. Local heat transfer in turbine disk-cavities. I - Rotor and stator cooling with hub injection of coolant

    NASA Astrophysics Data System (ADS)

    Bunker, R. S.; Metzger, D. E.; Wittig, S.

    1990-06-01

    Detailed radial heat-transfer coefficient distributions applicable to the cooling of disk-cavity regions of gas turbines are obtained experimentally from local heat-transfer data on both the rotating and stationary surfaces of a parallel-geometry disk-cavity system. Attention is focused on the hub injection of a coolant over a wide range of parameters including disk rotational Reynolds numbers of 200,000 to 50,000, rotor/stator spacing-to-disk ratios of 0.025 to 0.15, and jet mass flow rates between 0.10 and 0.40 times the turbulent pumped flow rate of a free disk. It is shown that rotor heat transfer exhibits regions of impingement and rotational domination with a transition region between, while stator heat transfer displays flow reattachment and convection regions with an inner recirculation zone.

  5. Flight energetics in sphinx moths: heat production and heat loss in Hyles lineata during free flight.

    PubMed

    Casey, T M

    1976-06-01

    1. Mean thoracic temperature of free-flying H. lineata in the field and in the laboratory increased from about 40 degrees C at Ta=16 degrees C to 42-5 degrees C at Ta=32 degrees C. At a given Ta, thoracic temperature was independent of body weight and weakly correlated with wing loading. 2. The difference between abdominal temperature and air temperature increased from 2 degrees C at low Ta to 4-2 degrees C at high Ta. At a given Ta, the difference between Tab and Ta was positively correlated with thoracic temperature. 3. Oxygen consumption per unit weight did not appear to vary with Ta from 15 to 30 degrees C and was inversely proportional to body weight. 4. Thermal conductance of the abdomen (Cab) was greater than thermal conductance of the thorax (Cth) in still air and at wind velocities up to 2-5 m/s. In moving air at speeds approximating flight, Cth was twice as high as in still air. Under the same conditions Cab was 3-4 times as high as in still air. 5. Thoracic and abdominal conductance are inversely proportional to their respective weights. 6. These data are consistent with the hypothesis that thoracic temperature is controlled by regulation of heat loss. However, a heat budget derived from these data suggests that heat dissipation may not be sufficient to offset the decrease in passive cooling of the thorax at high ambient temperatures. PMID:932632

  6. A comparison of microwave versus direct solar heating for lunar brick production

    NASA Technical Reports Server (NTRS)

    Yankee, S. J.; Strenski, D. G.; Pletka, B. J.; Patil, D. S.; Mutsuddy, B. C.

    1990-01-01

    Two processing techniques considered suitable for producing bricks from lunar regolith are examined: direct solar heating and microwave heating. An analysis was performed to compare the two processes in terms of the amount of power and time required to fabricate bricks of various sizes. Microwave heating was shown to be significantly faster than solar heating for rapid production of realistic-size bricks. However, the relative simplicity of the solar collector(s) used for the solar furnace compared to the equipment necessary for microwave generation may present an economic tradeoff.

  7. Origin, distribution and glaciological implications of Jurassic high heat production granites in the Weddell Sea rift, Antarctica

    NASA Astrophysics Data System (ADS)

    Leat, Phil T.; Jordan, Tom A. R. M.; Ferraccioli, Fausto; Flowerdew, Michael; R, Riley, Teal; Vaughan, Alan P. M.; Whitehouse, Martin

    2013-04-01

    The distribution of heat flow in Antarctic continental crust is critical to understanding ice sheet nucleation, growth and basal rheology and hydrology. We identify a group of High Heat Production granites intruded into Palaeozoic sedimentary sequences which may contribute to locally high heat flow beneath the central part of the West Antarctic Ice Sheet. Four of the granite plutons are exposed above ice sheet level at Pagano Nunatak, Pirrit Hills, Nash Hills and Whitmore Mountains. A new U-Pb zircon age from Pirrit Hills of 177.9 ± 2.3 Ma confirms earlier Rb-Sr dating that suggested an Early-Middle Jurassic age for the granites, coincident with the Karoo-Ferrar large igneous province and the first stage of Gondwana break-up. Our recently-acquired aerogeophysical data indicate that the plutons are distributed unevenly over 1000 km2 and were intruded into the actively extending, locally transcurrent, Jurassic Weddell Sea Rift [1]. In the NW part of the rift, the Pirrit Hills, Nash Hills and Whitmore Mountains granites form small isolated intrusions within weakly deformed upper crust. In the SE part of the rift, where granite intrusion was strongly structurally controlled within transtensional structures, the Pagano Nunatak granite is the only outcrop of a probably multiphase, ca 180 km long granite intrusion. The granites are weakly peraluminous, S-type and have Th and U abundances up to 61 and 19 ppm respectively. Heat production of analysed granite samples is ca. 2.9-9.1 µWm-3, toward the upper limit of values for High Heat Production granites globally. The granites are thought to have been generated during mafic underplating of the Weddell Rift during eruption of the contemporaneous Karoo-Ferrar magmatism [2]. The high Th and U abundances may be related to fractionation of the high Th-U Ferrar basaltic magmas combined with assimilation of pelitic sedimentary rocks. The granites correspond to an area of West Antarctica that may have heat flow significantly above the Antarctic average, as predicted from satellite magnetic data [3]. [1] Jordan, T.A., et al., Inland extent of the Weddell Sea Rift imaged by new aerogeophysical data, Tectonophysics (2012), 10.1016/j.tecto.2012.09.010 [2] Storey, B.C., et al., Middle Jurassic within-plate granites in West Antarctica and their bearing on the break-up of Gondwanaland. J. Geol. Soc. Lond, (1988), 145, 999-1007. [3] Fox Maule, C., et al., Heat flux anomalies in Antarctica revealed by satellite magnetic data. Science (2005), 10.1126/science.1106888

  8. Local Rural Product as a "Relic" Spatial Strategy in Globalised Rural Spaces: Evidence from County Clare (Ireland)

    ERIC Educational Resources Information Center

    Wilson, Geoff A.; Whitehead, Ian

    2012-01-01

    Using a case study from County Clare (Ireland), this study critically analyses notions of "local" rural production. It investigates where rural businesses source the different components of their products and how these interrelate with the locality, how local businesses use the notion of "local" in their product branding, and what the

  9. Local Rural Product as a "Relic" Spatial Strategy in Globalised Rural Spaces: Evidence from County Clare (Ireland)

    ERIC Educational Resources Information Center

    Wilson, Geoff A.; Whitehead, Ian

    2012-01-01

    Using a case study from County Clare (Ireland), this study critically analyses notions of "local" rural production. It investigates where rural businesses source the different components of their products and how these interrelate with the locality, how local businesses use the notion of "local" in their product branding, and what the…

  10. Excess recovery heat production by isolated muscles from mice overexpressing uncoupling protein-3.

    PubMed

    Curtin, N A; Clapham, J C; Barclay, C J

    2002-07-01

    Contractile and energetic performance of bundles of muscle fibres from the soleus of mice overexpressing uncoupling protein 3 (UCP-3tg) were compared with the performance of bundles from wild-type mice. Force and heat production were measured during a series of thirty 0.2 s isometric tetani at L(o), the length optimal for force. UCP-3tg fibres were as strong as the wild-type and maintained force in the series equally well; in the first tetanus force was 116.9 +/- 15.1 and 133.3 +/- 19.7 mN x mm(-2) respectively (all values means +/- S.E.M., n = 6 for UCP-3tg and n = 5 for wild-type). Heat production was partitioned into initial heat (due to contractile ATPases and the creatine kinase reaction) and recovery heat (due to other ATP-supplying processes) and expressed relative to the first cycle total heat. Initial heat production was similar for the UCP-3tg and wild-type fibres, decreasing during the series from 0.799 +/- 0.052 to 0.661 +/- 0.061 relative units (UCP-3tg), and from 0.806 +/- 0.024 to 0.729 +/- 0.039 relative units (wild-type). In both types the recovery heat was small at the start of the series and increased as the series progressed. At the end of the series, recovery heat production by UCP-3tg fibres, 1.575 +/- 0.246 relative units, was twice that of the wild-type fibres, 0.729 +/- 0.072 relative units. The extra recovery heat represents inefficient recovery in UCP-3tg fibres. This is the first direct evidence of enhanced energy dissipation as heat when UCP-3tg is overexpressed. PMID:12096064

  11. Study of heat production and transfer in shredded tires

    NASA Astrophysics Data System (ADS)

    Sellassie, Kassahun G.

    The purpose of this study is to determine the cause(s) of initial exothermic reactions in shredded tire. The primary hypothesis was that the oxidation of exposed steel wires, the oxidation of rubber, or sulfur causes the exothermic reactions in shredded tire. Laboratory tests were conducted to determine the heat transfer properties of the shredded tires by using a hot-plate apparatus. The experiments were conducted by varying the physical and environmental conditions as follows: (1) Tire size, (2) Wire content, (3) Water content, (4) Effective stress, (5) Air supply, (6) pH, (7) Humic Acid. First, laboratory testing was conducted to determine the effects of tire size on the heat transfer properties of shredded tires. The heat coefficient and diffusivity ranged from 3.0 to 3.5 W/m-K and 0.0002 to 0.00084 m 2/hour, respectively. Next, experiments were conducted to determine the effects of wire content on the exothermic reaction rate of tire shreds. When various amounts of wire (i.e., 5% to 15%) were exposed, the reaction rate increased, 2800 Btu for every lb of iron that is oxidized. In comparison, tire shreds with no wire were also tested under the same experimental conditions as above, however, no exothermic reaction occurred. These tests (i.e., with no wire) illustrate that carbon black in rubber molecule considers not oxidize. It was postulated that the reaction between iron in the wire and sulfur in the tire may be a potential cause of the exothermic reaction under low oxygen conditions. Experiments without air supply yielded no exothermic reaction. Thus, sulfur did not cause exotherm, because it is at low energy level and immobilized in the vulcanization process. In addition, experiments were conducted as the air supply was varied from 0 to 4 psi. With air pressure of less than 4-psi, no reaction occurred until 4-psi air was provided for the experiment. In conclusion, the design of an embankment with tire shreds should include shredded tires of bigger size without wire and the surface must be sealed to avoid any entrance of air into an embankment of shredded tires. Proper compact of the tire shreds should be conducted to reduce the air voids.

  12. Determination of the local heat-transfer characteristics on glaze ice accretions on a cylinder and a NACA 0012 airfoil

    NASA Astrophysics Data System (ADS)

    Pais, Martin Rabindra

    1987-12-01

    Laboratory scale experiments conducted in the subsonic wind tunnel facility at the University of Kentucky are discussed. Experimental convective local heat transfer coefficients were obtained for a simulated, full scale, selected set of 2, 5, 15 minute glaze ice models on a cylinder, and 0, 5 minute glaze ice models on a NACA 0012 airfoil. A steady state heat flux method was employed. The results show very good quantitative and qualitative agreement. The local heat transfer rate increases with increasing Reynolds number and as the ice grows shows a decreasing trend within the cup-like region formed in the forward zone. An attempt was made to define surface roughness by applying two-dimensional Fourier analysis to surface profiles of a 15 minute glaze ice accretion on a cylinder. When results of smooth glaze ice models are compared to those of rough models increases of up to 115 percent in the local heat-transfer rate are observed to occur primarily at the tips of the horns. This increase is partially attributed to the increase in area subtended by the roughness elements to the flow. A numerical formulation of a two-dimensional, unsteady, compressible Navier-Stokes code is introduced. Numerical tests are performed on the NACA 0012 profile and compared with experimental results.

  13. Biodiesel production process from microalgae oil by waste heat recovery and process integration.

    PubMed

    Song, Chunfeng; Chen, Guanyi; Ji, Na; Liu, Qingling; Kansha, Yasuki; Tsutsumi, Atsushi

    2015-10-01

    In this work, the optimization of microalgae oil (MO) based biodiesel production process is carried out by waste heat recovery and process integration. The exergy analysis of each heat exchanger presented an efficient heat coupling between hot and cold streams, thus minimizing the total exergy destruction. Simulation results showed that the unit production cost of optimized process is 0.592$/L biodiesel, and approximately 0.172$/L biodiesel can be avoided by heat integration. Although the capital cost of the optimized biodiesel production process increased 32.5% and 23.5% compared to the reference cases, the operational cost can be reduced by approximately 22.5% and 41.6%. PMID:26133477

  14. Adaptation to hot climate and strategies to alleviate heat stress in livestock production.

    PubMed

    Renaudeau, D; Collin, A; Yahav, S; de Basilio, V; Gourdine, J L; Collier, R J

    2012-05-01

    Despite many challenges faced by animal producers, including environmental problems, diseases, economic pressure, and feed availability, it is still predicted that animal production in developing countries will continue to sustain the future growth of the world's meat production. In these areas, livestock performance is generally lower than those obtained in Western Europe and North America. Although many factors can be involved, climatic factors are among the first and crucial limiting factors of the development of animal production in warm regions. In addition, global warming will further accentuate heat stress-related problems. The objective of this paper was to review the effective strategies to alleviate heat stress in the context of tropical livestock production systems. These strategies can be classified into three groups: those increasing feed intake or decreasing metabolic heat production, those enhancing heat-loss capacities, and those involving genetic selection for heat tolerance. Under heat stress, improved production should be possible through modifications of diet composition that either promotes a higher intake or compensates the low feed consumption. In addition, altering feeding management such as a change in feeding time and/or frequency, are efficient tools to avoid excessive heat load and improve survival rate, especially in poultry. Methods to enhance heat exchange between the environment and the animal and those changing the environment to prevent or limit heat stress can be used to improve performance under hot climatic conditions. Although differences in thermal tolerance exist between livestock species (ruminants > monogastrics), there are also large differences between breeds of a species and within each breed. Consequently, the opportunity may exist to improve thermal tolerance of the animals using genetic tools. However, further research is required to quantify the genetic antagonism between adaptation and production traits to evaluate the potential selection response. With the development of molecular biotechnologies, new opportunities are available to characterize gene expression and identify key cellular responses to heat stress. These new tools will enable scientists to improve the accuracy and the efficiency of selection for heat tolerance. Epigenetic regulation of gene expression and thermal imprinting of the genome could also be an efficient method to improve thermal tolerance. Such techniques (e.g. perinatal heat acclimation) are currently being experimented in chicken. PMID:22558920

  15. Local Heat Transfer and CHF for Subcooled Flow Boiling - Annual Report 1997

    SciTech Connect

    Dr. Ronald D. Boyd

    2000-07-01

    The Thermal Science Research Center (TSRC) at Prairie View A&M University is involved in an international fusion reactor technology development program aimed at demonstrating the technical feasibility of magnetic fusion energy. This report highlights: (1) Recent accomplishments and pinpoints thermal hydraulic problem areas of immediate concern to the development of plasma-facing components, and (2) Next generation thermal hydraulic problems which must be addressed to insure safety and reliability in component operation. More specifically, the near-term thermal hydraulic problem entails: (1) generating an appropriate data base to insure the development of single-side heat flux correlations, and (2) evaluating previously developed single-side/uniform heated transformations and correlations to determine which can be used to relate the vast two-phase heat transfer and critical heat flux (CHF) technical literature for uniformly heated flow channels to single-side heated channels.

  16. Contrasting Metamorphic Record of Heat Production Anomalies in the Penokean Orogen of Northern Michigan.

    PubMed

    Attoh

    2000-05-01

    It is proposed that the contrasting metamorphic mineral assemblages of the isolated amphibolite facies metamorphic highs in the Penokean orogen of northern Michigan may be caused by different heat production rates in the Archean basement. This hypothesis is based on concentrations of K, U, and Th in the Archean basement gneisses and Paleoproterozoic metasediments that indicate significant contribution of radiogenic heating during Penokean metamorphism. Heat production was anomalously high ( approximately 10.6 Wm-3) where andalusite-bearing mineral assemblages indicate that high temperatures were attained at shallow crustal levels ( approximately 550 degrees -600 degrees C at approximately 3 kbar). In contrast, where exposed metamorphic rocks indicate peak temperatures of 600 degrees -650 degrees C at 6-7 kbar, heat production in the Archean basement was lower ( approximately 3.7 Wm-3). The effect of heat production rates on the metamorphic pressure-temperature paths was tested with numerical thermal models. The calculations show (1) that if the heat production rate, where andalusite-bearing assemblages formed, was significantly <6.0 Wm-3, the estimated pressure at peak temperatures (PTmax) would be much higher and lie in the sillimanite or kyanite stability fields; and (2) differences between PTmax estimates for the metamorphic highs based on thermobarometry can be reproduced if thermal history involved significant crustal thickening as well as moderate unroofing rates. PMID:10769161

  17. Permafrost thawing in organic Arctic soils accelerated by ground heat production

    NASA Astrophysics Data System (ADS)

    Hollesen, Jørgen; Matthiesen, Henning; Møller, Anders Bjørn; Elberling, Bo

    2015-06-01

    Decomposition of organic carbon from thawing permafrost soils and the resulting release of carbon to the atmosphere are considered to represent a potentially critical global-scale feedback on climate change. The accompanying heat production from microbial metabolism of organic material has been recognized as a potential positive-feedback mechanism that would enhance permafrost thawing and the release of carbon. This internal heat production is poorly understood, however, and the strength of this effect remains unclear. Here, we have quantified the variability of heat production in contrasting organic permafrost soils across Greenland and tested the hypothesis that these soils produce enough heat to reach a tipping point after which internal heat production can accelerate the decomposition processes. Results show that the impact of climate changes on natural organic soils can be accelerated by microbial heat production with crucial implications for the amounts of carbon being decomposed. The same is shown to be true for organic middens with the risk of losing unique evidence of early human presence in the Arctic.

  18. Myeloperoxidase in human peripheral blood lymphocytes: Production and subcellular localization.

    PubMed

    Okada, Sabrina Sayori; de Oliveira, Edson Mendes; de Arajo, Tomaz Henrique; Rodrigues, Maria Rita; Albuquerque, Renata Chaves; Mortara, Renato Arruda; Taniwaki, Noemi Nosomi; Nakaya, Helder Imoto; Campa, Ana; Moreno, Ana Carolina Ramos

    2016-02-01

    Myeloperoxidase (MPO) is an important enzyme in the front-line protection against microorganisms. In peripheral blood, it is accepted that MPO is only produced by myeloid-lineage cells. Thus, MPO presence is unexpected in lymphocytes. We showed recently that B1-lymphocytes from mice have MPO. Here, we showed that subsets of human peripheral B, CD4(+) and CD8(+) T lymphocytes express MPO. The content of MPO in lymphocytes was very low compared to neutrophils/monocytes with a preferential distribution in the nucleus and perinuclear region. Also, we performed a MPO mRNA expression analysis from human blood cells derived from microarray raw data publicly available, showing that MPO is modulated in infectious disease. MPO was increased in CD4(+) T lymphocytes from HIV chronic infection and in CD8(+) T lymphocytes from HCV-positive patients. Our study points out MPO as a multifunctional protein due to its subcellular localization and expression modulation in lymphocytes indicating alternative unknown functions for MPO in lymphocytes. PMID:26632272

  19. Localized Recrystallization in Cast Al-Si-Mg Alloy during Solution Heat Treatment: Dilatometric and Calorimetric Studies

    NASA Astrophysics Data System (ADS)

    Chaudhury, S. K.; Warke, V.; Shankar, S.; Apelian, D.

    2011-10-01

    During heat treatment, the work piece experiences a range of heating rates depending upon the sizes and types of furnace. When the Al-Si-Mg cast alloy is heated to the solutionizing temperature, recrystallization takes place during the ramp-up stage. The effect of heating rate on recrystallization in the A356 (Al-Si-Mg) alloy was studied using dilatometric and calorimetric methods. Recrystallization in as-cast Al-Si alloys is a localized event and is confined to the elasto-plastic zone surrounding the eutectic Si phase; there is no evidence of recrystallization in the center of the primary Al dendritic region. The size of the elasto-plastic zone is of the same order of magnitude as the Si particles, and recrystallized grains are observed in the elasto-plastic region near the Si particles. The coefficient of thermal expansion of Al is an order of magnitude greater than Si, and thermal stresses are generated due to the thermal mismatch between the Al phase and Si particles providing the driving force for recrystallization. In contrast, recrystallization in Al wrought alloy (7075) occurs uniformly throughout the matrix, stored energy due to cold work being the driving force for recrystallization in wrought alloys. The activation energy for recrystallization in as-cast A356 alloy is 127 KJ/mole. At a slow heating rate of 4.3 K/min, creep occurs during the heating stage of solution heat treatment. However, creep does not occur in samples heated at higher heating rates, namely, 520, 130, and 17.3 K/min.

  20. ENERGY PRODUCTION AND RESIDENTIAL HEATING: TAXATION, SUBSIDIES, AND COMPARATIVE COSTS

    EPA Science Inventory

    This analysis is in support of the Ohio River Basin Energy Study (ORBES), a multidisciplinary policy research program supported by the Environmental Protection Agency. It examines the effect of economic incentives on public and private decisions affecting energy production and us...

  1. Investigation of Local Heat-transfer and Pressure Drag Characteristics of a Yawed Circular Cylinder at Supersonic Speeds

    NASA Technical Reports Server (NTRS)

    Goodwin, Glen; Creager, Marcus O; Winkler, Ernest L

    1956-01-01

    Local heat-transfer coefficients, temperature recovery factors, and pressure distributions were measured on the front side of a circular cylinder at a nominal Mach number of 3.9 over a range of free-stream Reynolds numbers from 2.1 x 10 to the 3rd power to 6.7 x 10 to the 3rd power and yaw angles from zero degrees to 44 degrees. Yawing the cylinder reduced the heat-transfer coefficients and the pressure drag coefficients. The amount of reduction may be predicted by a theory presented herein.

  2. Local heat transfer coefficients and superficial bed porosity of a horizontal cylinder in bubbling fluidized beds of geldart B particles

    NASA Astrophysics Data System (ADS)

    Di Natale, Francesco; Nigro, Roberto

    2012-05-01

    In this work, experimental values of local heat transfer coefficients around a horizontal cylinder immersed in a bubbling fluidized bed are reported for three types of bed materials classified as Geldart B particles, fluidized with air at ambient pressure and temperature. Results are interpreted in light of a model for heat transfer coefficient in order to estimate the time-average bed porosity profile close to the exchange surface. These angular profiles of bed porosity are compared with former experiments to verify the correctness of the adopted model, and are used to provide a physical interpretation of the experimental results.

  3. Selective and localized radiofrequency heating of skin and fat by controlling surface distributions of the applied voltage: analytical study.

    PubMed

    Jimnez-Lozano, Joel; Vacas-Jacques, Paulino; Anderson, R Rox; Franco, Walfre

    2012-11-21

    At low frequencies (hundreds of kHz to a few MHz), local energy absorption is proportional to the conductivity of tissue and the intensity of the internal electric field. At 1MHz, the electric conductivity ratio between skin and fat is approximately 10; hence, skin would heat more provided the intensity of the electric field is similar in both tissues. It follows that selective and localized heat deposition is only feasible by varying electric fields locally. In this study, we vary local intensities of the internal electric field in skin, fat and muscle by altering its direction through modifying surface distributions of the applied voltage. In addition, we assess the long-term effects of these variations on tissue thermal transport. To this end, analytical solutions of the electric and bioheat equations were obtained using a regular perturbation method. For voltage distributions given by second- and eight-degree functions, the power absorption in fat is much greater than in skin by the electrode center while the opposite is true by the electrode edge. For a sinusoidal function, the absorption in fat varies laterally from greater to lower than in skin, and then this trend repeats from the center to the edge of the electrode. Consequently, zones of thermal confinement selectively develop in the fat layer. Generalizing these functions by parametrization, it is shown that radiofrequency (RF) heating of layered tissues can be selective and precisely localized by controlling the spatial decay, extent and repetition of the surface distribution of the applied voltage. The clinical relevance of our study is to provide a simple, non-invasive method to spatially control the heat deposition in layered tissues. By knowing and controlling the internal electric field, different therapeutic strategies can be developed and implemented. PMID:23104083

  4. System for vaporizing carbon dioxide utilizing the heat by-product of the refrigeration system as a heat source

    SciTech Connect

    Shaw, H.L.

    1980-12-23

    The present invention is directed to a carbonation and refrigeration system wherein the heat of the refrigerant output side of the refrigeration compressor is utilized to vaporize liquid carbon dioxide into CO/sub 2/ gas which is introduced into a liquid product. The carbonation and refrigeration system successfully utilizes the heat of the refrigerant to vaporize the CO/sub 2/ liquid regardless of the cooling demand of the system caused by seasonal temperature variations. For example during the winter months when the cooling demand is as low as 10% of the cooling demand in the summer, the carbonation and refrigeration system operates effectively to vaporize the CO/sub 2/ liquid by means of a heat exchanger and a desuperheater which are connected in communication with the superheated vapor emerging from the output side of a refrigeration compressor. In addition, the carbonation and refrigeration system of the present invention cools more efficiently by extracting some of the heat from the condensed refrigerant entering the receiver of the refrigeration system. In this manner, the refrigeration compressor can operate more efficiently.

  5. Bradykinin-induced nociceptor sensitization to heat is mediated by cyclooxygenase products in isolated rat skin.

    PubMed

    Peth, G; Derow, A; Reeh, P W

    2001-07-01

    Bradykinin can excite C-polymodal nociceptors and sensitize them to heat and it can also enhance prostaglandin synthesis, but it is unclear whether these effects are causally related. The role of cyclooxygenase products was investigated using two enantiomers of the cyclooxygenase inhibitor flurbiprofen of which S(+)- is more potent than R(-)-flurbiprofen. Single-unit activity was recorded from mechano-heat-sensitive, polymodal C-fibers in the isolated rat skin-saphenous nerve preparation. Bradykinin pretreatment (10 microM, 5 min) induced a 219 +/- 26% increase in the number of spikes evoked by noxious heat stimulation and a drop in the heat threshold by 5.2 +/- 0.6 degrees C in a fully reproducible manner. S(+)-flurbiprofen (1 microM) abolished the bradykinin-induced heat sensitization but did not alter the unconditioned heat response itself. Under R(-)-flurbiprofen (1 microM) bradykinin still induced a significant heat sensitization which was reduced by 33 +/- 21% (P = 0.11) of its previous extent; this effect may be due to the limited purity of the enantiomer preparation or to a cyclooxygenase-independent action of flurbiprofen. The heat sensitization suppressed by S(+)-flurbiprofen could be significantly restored (to 43 +/- 12%) by addition of PGE(2) plus PGI(2) (10 microM both) to bradykinin. Neither S(+)- nor R(-)-flurbiprofen had an influence on the magnitude of the excitatory effect of bradykinin. It is concluded that (i) cyclooxygenase products are the main mediators of nociceptor sensitization to heat following bradykinin treatment in the isolated rat skin; (ii) PGE(2)/I(2) are essential but perhaps not the only relevant cyclooxygenase products involved and (iii) neither S(+)- nor R(-)-flurbiprofen inhibit the unconditioned noxious heat response and the excitatory bradykinin response of the polymodal C-nociceptors. PMID:11553274

  6. Genetic interactions for heat stress and production level: predicting foreign from domestic data

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Genetic by environmental interactions were estimated from U.S. national data by separately adding random regressions for heat stress (HS) and herd production level (HL) to the all-breed animal model to improve predictions of future records and rankings in other climate and production situations. Yie...

  7. 78 FR 63410 - Energy Conservation Program for Consumer Products: Test Procedures for Direct Heating Equipment...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-24

    ... energy consumption of these products, as required under EPCA.\\3\\ 75 FR 52892. DOE published a... provides guidance on rounding and sampling. 76 FR 56347. DOE published a final rule adopting standby mode and off mode provisions for heating products in the Federal Register on December 17, 2012. 77 FR...

  8. Heat Production During Countermeasure Exercises Planned for the International Space Station

    NASA Technical Reports Server (NTRS)

    Rapley, Michael G.; Lee, Stuart M. C.; Guilliams, Mark E.; Greenisen, Michael C.; Schneider, Suzanne M.

    2004-01-01

    This investigation's purpose was to determine the amount of heat produced when performing aerobic and resistance exercises planned as part of the exercise countermeasures prescription for the ISS. These data will be used to determine thermal control requirements of the Node 1 and other modules where exercise hardware might reside. To determine heat production during resistive exercise, 6 subjects using the iRED performed 5 resistance exercises which form the core exercises of the current ISS resistive exercise countermeasures. Each exerciser performed a warm-up set at 50% effort, then 3 sets of increasing resistance. We measured oxygen consumption and work during each exercise. Heat loss was calculated as the difference between the gross energy expenditure (minus resting metabolism) and the work performed. To determine heat production during aerobic exercise, 14 subjects performed an interval, cycle exercise protocol and 7 subjects performed a continuous, treadmill protocol. Each 30-min. exercise is similar to exercises planned for ISS. Oxygen consumption monitored continuously during the exercises was used to calculate the gross energy expenditure. For cycle exercise, work performed was calculated based on the ergometer's resistance setting and pedaling frequency. For treadmill, total work was estimated by assuming 25% work efficiency and subtracting the calculated heat production and resting metabolic rate from the gross energy expenditure. This heat production needs to be considered when determining the location of exercise hardware on ISS and designing environmental control systems. These values reflect only the human subject s produced heat; heat produced by the exercise hardware also will contribute to the heat load.

  9. Study of Local Plasma Heating during Magnetic Reconnection by Tomographic Ion Doppler Spectroscopy in TS-3, TS-4 and MAST

    NASA Astrophysics Data System (ADS)

    Tanabe, Hiroshi; Kuwahata, Akihiro; Yamada, Takuma; Watanabe, Takenori; Gi, Keii; Annoura, Masanobu; Kadowaki, Kazutake; Kaminou, Yasuhiro; Koike, Hideya; Nishida, Kento; Inomoto, Michiaki; You, Setthivoine; Crowley, Brendan; Conway, Neil; Scannel, Rory; Gryaznevich, Mikhail; Ono, Yasushi

    2013-10-01

    For the past decade, local plasma heating during magnetic reconnection has been investigated in TS-3 and TS-4 by use of 2D Doppler tomography and in-situ probe diagnostics. Our merging experiments revealed significant ion heating in the outflow region and electron heating around X point. The reconnection heating energy scales with the square of reconnecting field Brec and reaches ~200 eV at maximum with Brec ~0.1T. As a promising CS-less spherical tokamak startup technique, the reconnection/merging startup in MAST achieved the maximum ions and electron temperatures over 1 keV. The high-resolution Thomson scattering with 130 chords reveals direct electron heating at the X-point and electron density pile-up in the downstream. The 32 chords Doppler tomography system was installed on the midplane of MAST for the purpose of measuring the radial profile of ion temperature. The measured triple peaks of ion temperature indicate the ion heating in the downstream as well as that in the current sheet with and without the assist of centre solenoid coil.

  10. Combined heat and power for drinking water production

    SciTech Connect

    Chellini, R.

    1996-04-01

    ABB Kraftwerke AG, of Mannheim, Germany, is presently involved in two huge projects aimed at supplying electric power and drinking water in the Arabian Gulf. To limit fuel consumption as much as possible, electricity and water are produced in CHP plants. These plants are powered either by gas turbines equipped with HRSGs, or by conventional boilers feeding controlled extraction-condensing steam turbines. The selection of one of the two systems depends mainly on the type of fuel available (oil or natural gas), on the power/water loads through the year and other local factors. The gas turbine-based CHP systems can be setup in a shorter time and feature a slightly higher overall efficiency. The steam turbine solution, once the plant is commissioned, needs less maintenance. In the final analysis, operating costs of the two solutions are equivalent.

  11. Role of local heating in crystallization of amorphous alloys under ball milling: An experiment on Fe{sub 90}Zr{sub 10}

    SciTech Connect

    Kwon, Y. S.; Kim, J. S.; Povstugar, I. V.; Yelsukov, E. P.; Choi, P. P.

    2007-04-01

    Fe{sub 90}Zr{sub 10} was chosen as a model system to elucidate the roles of mechanical deformation and local heating in the phenomenon of ball-milling-induced crystallization of amorphous alloys. The structural evolution of melt-spun amorphous Fe{sub 90}Zr{sub 10} ribbons under different milling conditions and high-pressure torsion was investigated by means of x-ray diffraction, Moessbauer spectroscopy, and magnetic measurements. Despite a considerable difference in the local temperatures for high-energy and low-energy ball millings, cryomilling (under liquid nitrogen-cooling), and high-pressure torsion, amorphous Fe{sub 90}Zr{sub 10} crystallizes into a supersaturated {alpha}-Fe(Zr) solid solution in all cases. Local heating occurring under high- and low-energy millings only plays a minor role and leads to a slight shift of the crystallization products towards equilibrium state. Mechanical deformation was established as the primary cause of crystallization of the amorphous Fe-Zr alloy under ball milling.

  12. Encoding the structure of many-body localization with matrix product operators

    NASA Astrophysics Data System (ADS)

    Pekker, David; Clark, Bryan K.

    2015-03-01

    Anderson insulators are non-interacting disordered systems which have localized single particle eigenstates. The interacting analogue of Anderson insulators are the Many-Body Localized (MBL) phases. The natural language for representing the spectrum of the Anderson insulator is that of product states over the single-particle modes. We show that product states over Matrix Product Operators of small bond dimension is the corresponding natural language for describing the MBL phases. In this language all of the many-body eigenstates are encode by Matrix Product States (i.e. DMRG wave function) consisting of only two sets of low bond-dimension matrices per site: the Gi matrix corresponding to the local ground state on site i and the Ei matrix corresponding to the local excited state. All 2 n eigenstates can be generated from all possible combinations of these matrices.

  13. Identification of potential local isolated for biosurfactant production

    NASA Astrophysics Data System (ADS)

    Shafiei, Zahra; Yusoff, Wan Mohtar Wan; Hamid, Aidil Abdul; Moazami, Nasrin; Hamzah, Ainon; Fooladi, Taybeh

    2013-11-01

    Biosurfactant are amphiphilic molecule that have received increasing attention in recent years because of their role in the growth of microorganisms on water-insoluble hydrophobic materials such as hydrocarbons as well as their commercial potential in the cosmetics, food, oil recovery and agricultural industries. In this study a potential biosurfactant producing strain was isolated from several soil samples of Terengganu oil refinery, Malaysia and selected during preliminary screening using hemolytic activity, oil spreading and drop collapsed technique. Isolates with at least more than one positive response to these three methods were subjected to complementary screening by measuring surface tension reduction as well as emulsification capacity. The biosurfactant produced by isolated 5M was able to reduced surface tension of culture medium from 60 mN/m to30mN/m. The biochemical and morphological characterization, 16SrRNA gene sequencing showed that the isolated 5M belongs to bacillus groups. The maximum production of biosurfactant by Bacillus 5M was observed after 48 h of incubation.

  14. Localized heating of electrons in ionization zones: Going beyond the Penning-Thornton paradigm in magnetron sputtering

    SciTech Connect

    Anders, Andre

    2014-12-07

    The fundamental question of how energy is supplied to a magnetron discharge is commonly answered by the Penning-Thornton paradigm invoking secondary electrons. Huo et al. (Plasma Sources Sci. Technol. 22, 045005, (2013)) used a global discharge model to show that electron heating in the electric field of the magnetic presheath is dominant. In this contribution, this concept is applied locally taking into account the electric potential structure of ionization zones. Images of ionization zones can and should be interpreted as diagrams of the localization of electric potential and related electron energy, where certain collisions promote or dampen their formation.

  15. Determination of Local Experimental Heat-Transfer Coefficients on Combustion Side of an Ammonia-Oxygen Rocket

    NASA Technical Reports Server (NTRS)

    Liebert, Curt H.; Ehlers, Robert C.

    1961-01-01

    Local experimental heat-transfer coefficients were measured in the chamber and throat of a 2400-pound-thrust ammonia-oxygen rocket engine with a nominal chamber pressure of 600 pounds per square inch absolute. Three injector configurations were used. The rocket engine was run over a range of oxidant-fuel ratio and chamber pressure. The injector that achieved the best performance also produced the highest rates of heat flux at design conditions. The heat-transfer data from the best-performing injector agreed well with the simplified equation developed by Bartz at the throat region. A large spread of data was observed for the chamber. This spread was attributed generally to the variations of combustion processes. The spread was least evident, however, with the best-performing injector.

  16. Initial Evaluation of the Heat-Affected Zone, Local Embrittlement Phenomenon as it Applies to Nuclear Reactor Vessels

    SciTech Connect

    McCabe, D.E.

    1999-09-01

    The objective of this project was to determine if the local brittle zone (LBZ) problem, encountered in the testing of the heat-affected zone (HAZ) part of welds in offshore platform construction, can also be found in reactor pressure vessel (RPV) welds. Both structures have multipass welds and grain coarsening along the fusion line. Literature was obtained that described the metallurgical evidence and the type of research work performed on offshore structure welds.

  17. Application of deterministic chaos theory to local instantaneous temperature, pressure, and heat transfer coefficients in a gas fluidized bed

    SciTech Connect

    Karamavruc, A.I.; Clark, N.N.

    1996-09-01

    A stainless steel heat transfer tube, carrying a hot water flow, was placed in a cold bubbling fluidized bed. The tube was instrumented in the circumferential direction with five fast-responding surface thermocouples and a vertical pressure differential sensor. The local temperature and pressure data were measured simultaneously at a frequency of 120 Hz. Additionally, the local instantaneous heat transfer coefficient was evaluated by solving the transient two-dimensional heat conduction equation across the tube wall numerically. The mutual information function (MIF) has been applied to the signals to observe the relationship between points separated in time. MIF was also used to provide the most appropriate time delay constant {tau} to reconstruct an m-dimensional phase portrait of the one-dimensional time series. The distinct variation of MIF around the tube indicates the variations of solid-surface contact in the circumferential direction. The correlation coefficient was evaluated to calculate the correlation exponent {nu}, which is closely related to the fractal dimension. The correlation exponent is a measure of the strange attractor. The minimum embedding dimension as well as the degrees of freedom of the system were evaluated via the correlation coefficient. Kolmogorov entropies of the signals were approximated by using the correlation coefficient. Kolmogorov entropy considers the inherent multi-dimensional nature of chaotic data. A positive estimation of Kolmogorov entropy is an indication of the chaotic nature of the signal. The Kolmogorov entropies of the temperature data around the tube were found to be between 10 bits/s and 24 bits/s. A comparison between the signals has shown that the local instantaneous heat transfer coefficient exhibits a higher degree of chaos than the local temperature and pressure signals.

  18. Converting the patterns of local heat flux via thermal illusion device

    NASA Astrophysics Data System (ADS)

    Zhu, N. Q.; Shen, X. Y.; Huang, J. P.

    2015-05-01

    Since the thermal conduction equation has form invariance under coordinate transformation, one can design thermal metamaterials with novel functions by tailoring materials' thermal conductivities. In this work, we establish a different transformation theory, and propose a layered device with anisotropic thermal conductivities. The device is able to convert heat flux from parallel patterns into non-parallel patterns and vice versa. In the mean time, the heat flux pattern outside the device keeps undisturbed as if this device is absent. We perform finite-element simulations to confirm the converting behavior. This work paves a different way to manipulate the flow of heat at will.

  19. Localized dryout: An approach for managing the thermal hydrologi-cal effects of decay heat at Yucca Mountain

    SciTech Connect

    Buscheck, T. A.; Nitao, J.J.; Ramspott, L.D.

    1995-11-01

    For a nuclear waste repository in the unsaturated zone at Yucca Mountain, there are two thermal loading approaches to using decay heat constructively -- that is, to substantially reduce relative humidity and liquid flow near waste packages for a considerable time, and thereby limit waste package degradation and radionuclide dissolution and release. ``Extended dryout`` achieves these effects with a thermal load high enough to generate large-scale (coalesced) rock dryout. ``Localized dryout``(which uses wide drift spacing and a thermal load too low for coalesced dryout) achieves them by maintaining a large temperature difference between the waste package and drift wall; this is done with close waste package spacing (generating a high line-heat load) and/or low-thermal-conductivity backfill in the drift. Backfill can greatly reduce relative humidity on the waste package in both the localized and extended dryout approaches. Besides using decay heat constructively, localized dryout reduces the possibility that far-field temperature rise and condensate buildup above the drifts might adversely affect waste isolation.

  20. Subtask 12D1: Impact properties of production heat of V-4Cr-4Ti

    SciTech Connect

    Chung, H.M.; Nowicki, L.; Smith, D.L.

    1995-03-01

    Following previous reports of excellent properties of a laboratory heat of V-4Cr-4Ti, the alloy identified as the primary vanadium-based candidate for application as fusion reactor structural components, a large production-scale (500-kg) heat of the alloy was fabricated successfully. Since impact toughness has been known to be most sensitive to alloy composition and microstructure, impact testing of the production-scale heat was conducted in this work between -200{degrees}C and +200{degrees}C. A 500-kg heat of V-4Cr-4Ti, an alloy identified previously as the primary vanadium-based candidate alloy for application as fusion reactor structural components, has been produced successfully. Impact tests were conducted at -196{degrees}C to 150{degrees}C on 1/3-size Charpy specimens of the scale-up heat in as-rolled condition and after annealing for 1 h at 950, 1000, and 1050{degrees}C in high-quality vacuum. The annealed material remained ductile at all test temperatures; the ductile-brittle transition temperature (DBTT) was lower than -200{degrees}C. The upper-shelf energy of the production-scale heat was similar to that of the laboratory-scale ({approx}30-kg) heat of V-4Cr-4Ti investigated previously. Effect of annealing temperature was not significant; however, annealing at 1000{degrees}C for 1 h not only produces best impact properties but also ensures a sufficient tolerance to effect of temperature inhomogeneity expected when annealing large components. Effect of notch geometry was also investigated on the production heat. When annealed properly (e.g., at 1000{degrees}C for 1 h), impact properties were not sensitive to notch geometry (45{degrees}-notch, root radius 0.25 mm; and 300-notch, root radius 0.08 mm). 11 refs., 6 figs., 1 tab.

  1. Simulated heat flux and sea ice production at coastal polynyas in the southwestern Weddell Sea

    NASA Astrophysics Data System (ADS)

    Haid, V.; Timmermann, R.

    2013-05-01

    Coastal polynyas are areas in an ice-covered ocean where the ice cover is exported, mostly by off-shore winds. The resulting reduction of sea ice enables an enhanced ocean-atmosphere heat transfer. Once the water temperatures are at the freezing point, further heat loss induces sea ice production. The heat exchange and ice production in coastal polynyas in the southwestern Weddell Sea is addressed using the Finite-Element Sea-ice Ocean Model, a primitive-equation, hydrostatic ocean circulation model coupled with a dynamic-thermodynamic sea-ice model, which allows to quantify the amount of heat associated with cooling of the water column. Three important polynya regions are identified: at Brunt Ice Shelf, at Ronne Ice Shelf and along the southern part of the Antarctic Peninsula. Multiyear winter means (May-September 1990-2009) give an upward heat flux to the atmosphere of 311 W/m2 in the Brunt polynyas, 511 W/m2 in Ronne Polynya and 364 W/m2 in the Antarctic Peninsula polynyas, whereof 57 W/m2, 49 W/m2 and 48 W/m2, respectively, are supplied as oceanic heat flux from deeper layers. The mean winter sea ice production is 7.2 cm/d in the Brunt polynyas corresponding to an ice volume of 1.3 1010 m3/winter, 13.2 cm/d at Ronne polynya (4.4 1010 m3/winter), and 9.2 cm/d in the Antarctic Peninsula polynyas (2.1 1010 m3/winter). The heat flux to the atmosphere inside polynyas is 7 to 9 times higher than the heat flux in the adjacent area; polynya ice production per unit area exceeds adjacent values by a factor of 9 to 14.

  2. Greenhouse soil heating for improved production and energy conservation. Final report

    SciTech Connect

    Roller, W.L.; Elwell, D.L.

    1981-09-01

    A three-year study of the beneficial use of simulated power plant reject heat for soil heating in greenhouses is described. The effect of 25, 30, 35, and 40/sup 0/C warm water on the temperature of and moisture distribution in three diverse, greenhouse soils was studied, and the growth response of variety HR-5 lettuce in this environment was determined. Detailed information on soil temperature and moisture distribution, heat transfer rates, and lettuce production yield under various operating conditions was obtained.

  3. Materials experience and selection for nuclear materials production reactor heat exchangers

    SciTech Connect

    Marra, J.E.; Louthan, M.R. Jr.

    1990-01-01

    The primary coolant systems for the heavy-water nuclear materials production reactors at the Savannah River Site are coupled to the secondary coolant systems through shell and tube heat exchangers. The head, shell, and tube sheets of these heat exchangers are fabricated from AISI Type 304 grades of austenitic stainless steel. The 8,957 tubes in each heat exchanger were originally fabricated from Type 304 stainless steel, but service experience has lead to the use of Sea Cure tubing in newer systems. The design includes double tube sheets, core rods, and 33,410 square feet of heat transfer surface. Tubes are rolled into the tube sheets and seal welded after rolling. The tubes contain Type 304 stainless steel rods which are positioned in the center of each tube axis to increase the fraction of the cooling water contacting the heat transfer surface. Each reactor utilizes twelve heat exchangers; thus the 120+ reactor-years of operating experience provide approximately 1,440 heat exchanger-years of service. Fatigue, stress corrosion cracking, crevice corrosion, and pitting have been observed during the service life. This paper describes the observed degradation processes and uses the operational experience to recommend materials for the Heavy Water -- New Production Reactor (HW-NPR).

  4. Vacuum evaporation treatment of digestate: full exploitation of cogeneration heat to process the whole digestate production.

    PubMed

    Guercini, S; Castelli, G; Rumor, C

    2014-01-01

    Vacuum evaporation represents an interesting and innovative solution for managing animal waste surpluses in areas with high livestock density. To reduce operational costs, a key factor is the availability of an inexpensive source of heat, such as that coming from an anaerobic digestion (AD) plant. The aim of this study was to test vacuum evaporation for the treatment of cattle slurry digestate focusing on heat exploitation. Tests were performed with a pilot plant fed with the digestate from a full-scale AD plant. The results were used to evaluate if and how cogeneration heat can support both the AD plant and the subsequent evaporation of the whole daily digestate production in a full-scale plant. The concentrate obtained (12% total solids) represents 40-50% of the influent. The heat requirement is 0.44 kWh/kg condensate. Heat power availability exceeding the needs of the digestor ranges from 325 (in winter) to 585 kW (in summer) versus the 382 kW required for processing the whole digestate production. To by-pass fluctuations, we propose to use the heat coming from the cogenerator directly in the evaporator, tempering the digestor with the latent heat of distillation vapor. PMID:25098878

  5. An evaluation of alternate production methods for Pu-238 general purpose heat source pellets

    SciTech Connect

    Mark Borland; Steve Frank

    2009-06-01

    For the past half century, the National Aeronautics and Space Administration (NASA) has used Radioisotope Thermoelectric Generators (RTG) to power deep space satellites. Fabricating heat sources for RTGs, specifically General Purpose Heat Sources (GPHSs), has remained essentially unchanged since their development in the 1970s. Meanwhile, 30 years of technological advancements have been made in the applicable fields of chemistry, manufacturing and control systems. This paper evaluates alternative processes that could be used to produce Pu 238 fueled heat sources. Specifically, this paper discusses the production of the plutonium-oxide granules, which are the input stream to the ceramic pressing and sintering processes. Alternate chemical processes are compared to current methods to determine if alternative fabrication processes could reduce the hazards, especially the production of respirable fines, while producing an equivalent GPHS product.

  6. Evaluation of effective case depth in heat treated steel products using photothermal radiometry

    NASA Astrophysics Data System (ADS)

    Wang, C.; Mandelis, A.

    2008-01-01

    A quantitative calibrated methodology based on photothermal radiometric (PTR) depth-profilometry for non-contact, non-intrusive determination of effective case depth in heat treated case-hardened steel products was developed. Several types of heat-treated C1018 industrial steel screw products (with hexa- gonal, cylindrical and spherical heads) were statistically evaluated using the case-depth induced interferometric thermal-wave phase minima. Calibration curves for each type of sample were established with the help of conventional destructive indenter measurements. It is shown that PTR thermal-wave interferometric phase minima can be used as a fast, on-line inspection methodology of industrial steel products for non-destructive quality control of heat treating processes.

  7. Theoretical Design of a Thermosyphon for Efficient Process Heat Removal from Next Generation Nuclear Plant (NGNP) for Production of Hydrogen

    SciTech Connect

    Piyush Sabharwall; Fred Gunnerson; Akira Tokuhiro; Vivek Utgiker; Kevan Weaver; Steven Sherman

    2007-10-01

    The work reported here is the preliminary analysis of two-phase Thermosyphon heat transfer performance with various alkali metals. Thermosyphon is a device for transporting heat from one point to another with quite extraordinary properties. Heat transport occurs via evaporation and condensation, and the heat transport fluid is re-circulated by gravitational force. With this mode of heat transfer, the thermosyphon has the capability to transport heat at high rates over appreciable distances, virtually isothermally and without any requirement for external pumping devices. For process heat, intermediate heat exchangers (IHX) are required to transfer heat from the NGNP to the hydrogen plant in the most efficient way possible. The production of power at higher efficiency using Brayton Cycle, and hydrogen production requires both heat at higher temperatures (up to 1000oC) and high effectiveness compact heat exchangers to transfer heat to either the power or process cycle. The purpose for selecting a compact heat exchanger is to maximize the heat transfer surface area per volume of heat exchanger; this has the benefit of reducing heat exchanger size and heat losses. The IHX design requirements are governed by the allowable temperature drop between the outlet of the NGNP (900oC, based on the current capabilities of NGNP), and the temperatures in the hydrogen production plant. Spiral Heat Exchangers (SHE’s) have superior heat transfer characteristics, and are less susceptible to fouling. Further, heat losses to surroundings are minimized because of its compact configuration. SHEs have never been examined for phase-change heat transfer applications. The research presented provides useful information for thermosyphon design and Spiral Heat Exchanger.

  8. A simplified method for thermal analysis of a cowl leading edge subject to intense local shock-wave-interference heating

    NASA Technical Reports Server (NTRS)

    Mcgowan, David M.; Camarda, Charles J.; Scotti, Stephen J.

    1992-01-01

    Type IV shock wave interference heating on a blunt body causes extremely intense heating over a very localized region of the body. An analytical solution is presented to a heat transfer problem that approximates the shock wave interference heating of an engine cowl leading edge of the National Aero-Space Plane. The problem uses a simplified geometry to represent the leading edge. An analytical solution is developed that provides a means for approximating maximum temperature differences between the outer and inner surface temperatures of the leading edge. The solution is computationally efficient and, as a result, is well suited for conceptual and preliminary design or trade studies. Transient and steady state analyses are conducted, and results obtained from the analytical solution are compared with results of 2-D thermal finite element analyses over a wide range of design parameters. Isotropic materials as well as laminated composite materials are studied. Results of parametric studies are presented to indicate the effects of the thickness of the cowl leading edge and the width of the region heated by the shock wave interference on the thermal response of the leading edge.

  9. Analysis of Competitiveness and Support Instruments for Heat and Electricity Production from Wood Biomass in Latvia

    NASA Astrophysics Data System (ADS)

    Klavs, G.; Kudrenickis, I.; Kundzina, A.

    2012-01-01

    Utilisation of renewable energy sources is one of the key factors in a search for efficient ways of reducing the emissions of greenhouse gases and improving the energy supply security. So far, the district heating supply in Latvia has been based on natural gas, with the wood fuel playing a minor role; the same is true for decentralised combined heat-power (CHP) production. The paper describes a method for evaluation of the economic feasibility of heat and electricity production from wood biomass under the competition between different fuel types and taking into account the electricity market. For the simulation, a cost estimation model is applied. The results demonstrate that wood biomass can successfully be utilised for competitive heat production by boiler houses, while for electricity production by CHP utilities it cannot compete on the market (even despite the low prices on wood biomass fuel) unless particular financial support instruments are applied. The authors evaluate the necessary support level and the impact of two main support instruments - the investment subsidies and the feed-in tariff - on the economic viability of wood-fuelled CHP plants, and show that the feed-in tariff could be considered as an instrument strongly affecting the competitiveness of such type CHP. Regarding the feed-in tariff determination, a compromise should be found between the economy-dictated requirement to develop CHP projects concerning capacities above 5 MWel - on the one hand, and the relatively small heat loads in many Latvian towns - on the other.

  10. High radiogenic heat production in the Kerala Khondalite Block, Southern Granulite Province, India

    NASA Astrophysics Data System (ADS)

    Ray, Labani; Roy, Sukanta; Srinivasan, R.

    2008-04-01

    In situ radioelemental (K, U and Th) analysis and heat production estimates have been made at 59 sites in the Kerala Khondalite Block (KKB) of the Southern Granulite Province (SGP) of India. Together with the in situ analyses on granulites and gneisses previously reported from 28 sites, and heat production estimated from the published geochemical analyses on granites and syenites of the KKB, the new data set allows good characterization of heat production for the major granulite facies rocks and granitoids of the KKB. Garnet biotite gneisses are characterized by high levels of Th and U, with mean values of 60 and 3 ppm, respectively. Khondalites, leptynites and charnockites have slightly lower levels of Th (23, 20 and 22 ppm, respectively) and U (2.9, 2.4 and 0.9 ppm, respectively). The mean K, U, Th abundances for the granites, leucogranites and granitic gneisses ranges from 3.9 to 4.3%, 2.6 to 4.3 ppm, 22 to 50 ppm respectively, and for the syenites 4.8%, 2 ppm and 5.7 ppm. Mean radiogenic heat production values for garnet-biotite gneiss, khondalite, leptynite and charnockite are 5.5, 2.7, 2.4 and 2.2 ?W m-3, respectively. For the granites, leucogranites, granitic gneisses and syenites it is 2.6, 3.4, 4.6 and 1.4 ?W m-3, respectively. Heat production of granulite facies rocks, which are the most abundant rocks in KKB, correlate well with Th, but less with U, suggesting that variation is caused by Th and U bearing accessory minerals such as monazite and zircon. The high heat production of the KKB granulites are in contrast to the low heat production of the Late Archaean granulites of the Northern Block (NB) of the SGP which are highly depleted in radioelements and also the granulites of Madurai Block (MB) that have higher radioelemental abundances than in the granulites of the NB. The high heat production of the KKB granulites could be due to the nature of protoliths and/or metasomatism associated with Neoproteroic- to- Pan African alkaline magmatic activity represented by alkali granite and syenite-carbonatite emplacements and emplacement of pegmatites.

  11. Consistent pattern of local adaptation during an experimental heat wave in a pipefish-trematode host-parasite system.

    PubMed

    Landis, Susanne H; Kalbe, Martin; Reusch, Thorsten B H; Roth, Olivia

    2012-01-01

    Extreme climate events such as heat waves are expected to increase in frequency under global change. As one indirect effect, they can alter magnitude and direction of species interactions, for example those between hosts and parasites. We simulated a summer heat wave to investigate how a changing environment affects the interaction between the broad-nosed pipefish (Syngnathus typhle) as a host and its digenean trematode parasite (Cryptocotyle lingua). In a fully reciprocal laboratory infection experiment, pipefish from three different coastal locations were exposed to sympatric and allopatric trematode cercariae. In order to examine whether an extreme climatic event disrupts patterns of locally adapted host-parasite combinations we measured the parasite's transmission success as well as the host's adaptive and innate immune defence under control and heat wave conditions. Independent of temperature, sympatric cercariae were always more successful than allopatric ones, indicating that parasites are locally adapted to their hosts. Hosts suffered from heat stress as suggested by fewer cells of the adaptive immune system (lymphocytes) compared to the same groups that were kept at 18°C. However, the proportion of the innate immune cells (monocytes) was higher in the 18°C water. Contrary to our expectations, no interaction between host immune defence, parasite infectivity and temperature stress were found, nor did the pattern of local adaptation change due to increased water temperature. Thus, in this host-parasite interaction, the sympatric parasite keeps ahead of the coevolutionary dynamics across sites, even under increasing temperatures as expected under marine global warming. PMID:22303448

  12. Studies on the wholesomeness of ready-to-eat meat products. I. Bacteriological evaluation of comminuted heated products.

    PubMed

    Tittiger, F; Saschenbrecker, P W

    1973-01-01

    Bacteriological studies were conducted on comminuted heated types of ready-to-eat meat products. Seventy-five per cent of the samples showed total counts in the range of 100-10,000 organisms per gm. Of potential food poisoning organisms, coagulase positive staphylococci were present in 4% and Clostridium perfringens in 1.7% of all samples in low numbers. Of indicator organisms for fecal and sewage contamination, Escherichia coli were found in 3.2% and Streptococcus fecalis in 5.4% of the samples. The heat treatment applied during processing is not sufficient to destroy these organisms. PMID:4346796

  13. Local heat treatment of high strength steels with zoom-optics and 10kW-diode laser

    NASA Astrophysics Data System (ADS)

    Baumann, Markus; Krause, Volker; Bergweiler, Georg; Flaischerowitz, Martin; Banik, Janko

    2012-03-01

    High strength steels enable new solutions for weight optimized car bodies without sacrificing crash safety. However, cold forming of these steels is limited due to the need of high press capacity, increased tool wear, and limitations in possible geometries. One can compensate for these drawbacks by local heat treatment of the blanks. In high-deformation areas the strength of the material is reduced and the plasticity is increased by diode laser irradiation. Local heat treatment with diode laser radiation could also yield key benefits for the applicability of press hardened parts. High strength is not desired all over the part. Joint areas or deformation zones for requested crash properties require locally reduced strength. In the research project "LOKWAB" funded by the German Federal Ministry of Education and Research (BMBF), heat treatment of high strength steels was investigated in cooperation with Audi, BMW, Daimler, ThyssenKrupp, Fraunhofer- ILT, -IWU and others. A diode laser with an output power of 10 kW was set up to achieve acceptable process speed. Furthermore a homogenizing zoom-optics was developed, providing a rectangular focus with homogeneous power density. The spot size in x- and y-direction can be changed independently during operation. With pyrometer controlled laser power the surface temperature is kept constant, thus the laser treated zone can be flexibly adapted to the needs. Deep-drawing experiments show significant improvement in formability. With this technique, parts can be manufactured, which can conventionally only be made of steel with lower strength. Locally reduced strength of press hardened serial parts was demonstrated.

  14. Parameter study of r-process lanthanide production and heating rates in kilonovae

    NASA Astrophysics Data System (ADS)

    Lippuner, Jonas; Roberts, Luke F.

    2015-04-01

    Explosive r-process nucleosynthesis in material ejected during compact object mergers may lead to radioactively powered transients called kilonovae. The timescale and peak luminosity of these transients are sensitive to the composition of the material after nuclear burning ceases, as the composition determines the local heating rate from nuclear decays and the opacity. The presence of lanthanides in the ejecta can drastically increase the opacity. We use the new general-purpose nuclear reaction network SkyNet to run a parameter study of r-process nucleosynthesis for a range of initial electron fractions Ye, initial entropies s, and density decay timescales ?. We find that the ejecta is lanthanide-free for Ye >~ 0 . 22 - 0 . 3 , depending on s and ?. The heating rate is insensitive to s and ?, but certain, larger values of Ye lead to reduced heating rates, because single nuclides dominate the heating. With a simple model we estimate the luminosity, time, and effective temperature at the peak of the light curve. Since the opacity is much lower in the lanthanide-free case, we find the luminosity peaks much earlier at ~ 1 day vs. ~ 15 days in the lanthanide-rich cases. Although there is significant variation in the heating rate with Ye, changes in the heating rate do not mitigate the effect of the lanthanides. This research is partially supported by NSF under Award Numbers AST-1333520 and AST-1205732.

  15. Factors affecting aerobic recovery heat production and recovery ratio of frog sartorius.

    PubMed Central

    Godfraind-De Becker, A

    1989-01-01

    1. Sartorius muscles of Rana temporaria, equilibrated at 20 degrees C in Ringer solution buffered with phosphates, were stimulated isometrically for 0.2 up to 0.75 s at lengths varying from 1.03 to 1.48 times rest length, L0. The aerobic recovery heat was measured for 10.5 min after contraction. 2. The recovery heat production had a complex time course, showing a variable delay to maximum, declining thereafter. In most cases, the rate of heat production did not decrease monotonically; attention was focused on the slow exponential decay which only persisted from 1.5-5 min after contraction. This latter part of the time course was considered as strictly aerobic and characterized by the time constant tau s. 3. Increasing the tetanus duration from 0.2 to 0.75 s increased initial heat Qi and recovery heat Qr in proportion, so that the recovery ratio R (Qr/Qi) did not change; it was equal to 1.29 +/- 0.03 (S.E.M.; n = 44) for muscles at about L0. The kinetics of heat production were modified with longer tetani; in particular, tau s was increased from 2.2 to 5.2 min. 4. When muscles were stretched beyond L0, as long as there was no increase of the resting heat rate (stretch response or 'Feng effect'), recovery heat production had a similar evolution to that in muscles at about L0; R was constant and equal to 1.21 +/- 0.03 (n = 46). 5. When muscles were sufficiently stretched to develop a stretch response, R increased proportionally to the stretch response. The effect seemed independent of the contractile machinery, as it vanished concomitantly with the stretch response, while force and Qi remained unchanged for the length considered. The kinetics were also modified--the delay to maximum was no longer detected and tau s most likely increased. 6. Substitution of 60% of the NaCl of the Ringer solution by NaI (mol/mol) produced a significant increase of R, mainly due to the increase of Qr. 7. The results show that neither the time course nor the amount of aerobic recovery heat Qr are strictly determined by the amount of initial heat Qi. The hypothesis is discussed that Qr might include a variable fraction due to processes which are not directly implicated in the actin-myosin interactions, possibly those involving the cytosolic Ca2+ concentration and the rate of resting metabolism. Images Fig. 3 PMID:2621637

  16. Study of Hydrogen Production Method using Latent Heat of Liquefied Natural Gas

    NASA Astrophysics Data System (ADS)

    Ogawa, Masaru; Seki, Tatsuyoshi; Honda, Hiroshi; Nakamura, Motomu; Takatani, Yoshiaki

    In recent years, Fuel Cell Electrical Vehicle is expected to improve urban environment. Particularly a hydrogen fuel type FCEV expected for urban use, because its excellent characters such as short startup time, high responsibility and zero emission. On the other hand, as far as hydrogen production is concerned, large amount of CO2 is exhausted into the atmosphere by the process of LNG reforming. In our research, we studied the utilization of LNG latent heat for hydrogen gas production process as well as liquefied hydrogen process. Furthermore, CO2---Capturing as liquid state or solid state from hydrogen gas production process by LNG is also studied. Results of research shows that LNG latent heat is very effect to cool hydrogen gas for conventional hydrogen liquefied process. However, the LNG latent heat is not available for LNG reforming process. If we want to use LNG latent heat for this process, we have to develop new hydrogen gas produce process. In this new method, both hydrogen and CO2 is cooled by LNG directly, and CO2 is removed from the reforming gas. In order to make this method practical, we should develop a new type heat-exchanger to prevent solid CO2 from interfering the performance of it.

  17. Global Surface Currents and Heat Transport: A New Product for Investigating Ocean Dynamics

    NASA Astrophysics Data System (ADS)

    Sudre, J.; Morrow, R.

    2006-07-01

    A global ¼° reso lution surface current and surface heat tr ansport product is available at the Centre de Topographie des O céans et de l'Hydrosphère (CTOH) . The surface curren t field is calculated from a co mbination of altimetric geostrophic curren t anomalies, Qu ickscat Ek man curren ts at 15 m dep th and a climatolog ical mean geostrophic cir culation. The velocity field in th e equ atorial band is adapted from the equ atorial adjustment d escr ibed by [1]. These surface curren ts are co mbined with microw ave sea surface temper atur e (SST) d ata from the comb ined global TMI/A MSR-E ¼° SST product. A preliminary an alysis shows how the comb ined product can be used to calcu late h eat transports and heat budgets, and investig ate the relativ e roles of eddy heat transport, mean geostrophic heat tr ansport and Ekman heat tr ansport.

  18. The heat released in single catalytic events locally enhances enzyme diffusion

    NASA Astrophysics Data System (ADS)

    Tsekouras, Konstantinos; Riedel, Clement; Wilson, Christian; Hamadani, Kambiz; Marqusee, Susan; Presse, Steve; Bustamante, Carlos

    2014-03-01

    Recent experiments have shown that some enzymes catalyzing highly exothermic reactions exhibit increased diffusion with rising substrate concentration. We present a stochastic theory linking increased enzyme diffusion to reaction rate, discuss other possible origins for diffusion coefficient increases and finally provide a mechanistic interpretation showing how the heat released by the reaction perturbs the enzyme.

  19. Production of 5'-phosphodiesterase by Catharanthus roseus cells promoted by heat-degraded products generated from uronic acid.

    PubMed

    Akimoto-Tomiyama, Chiharu; Aoyagi, Hideki; Ozawa, Tetsuo; Tanaka, Hideo

    2002-01-01

    Polyalginate was autoclaved at 121 degrees C for 20 min and its molecular weight distribution was analyzed. The autoclaved alginate yielded alginate polymer, oligomer and heat degraded products (HDPs). Each of the separated substances promoted 5'-phosphodiesterase (5'-PDase) production in suspension culture of Catharanthus roseus cells. HDPs could also be generated from other uronic acids (galacturonic acid and glucuronic acid) by autoclave treatment. The most effective substance in the HDPs was isolated and characterized as trans-4,5-dihydroxy-2-cyclopenten-1-one (DHCP). The optimal conditions for DHCP production were also established (autoclaving 1 mg/ml monogalacturonic acid [pH 2] at 121 degrees C for 2 h). A combination of oligo-alginate (below 4 kDa) and HDPs significantly promoted the production of 5'-PDase in C. roseus. Based on the above results, a novel alginate complex that gave a 44-fold increase in 5'-PDase production by C. roseus was developed. PMID:16233285

  20. Complex patterns of local adaptation in heat tolerance in Drosophila simulans from eastern Australia.

    PubMed

    van Heerwaarden, B; Lee, R F H; Wegener, B; Weeks, A R; Sgró, C M

    2012-09-01

    Latitudinal clines are considered a powerful means of investigating evolutionary responses to climatic selection in nature. However, most clinal studies of climatic adaptation in Drosophila have involved species that contain cosmopolitan inversion polymorphisms that show clinal patterns themselves, making it difficult to determine whether the traits or inversions are under selection. Further, although climatic selection is unlikely to act on only one life stage in metamorphic organisms, a few studies have examined clinal patterns across life stages. Finally, clinal patterns of heat tolerance may also depend on the assay used. To unravel these potentially confounding effects on clinal patterns of thermal tolerance, we examined adult and larval heat tolerance traits in populations of Drosophila simulans from eastern Australia using static and dynamic (ramping 0.06 °C min(-1)) assays. We also used microsatellites markers to clarify whether demographic factors or selection are responsible for population differentiation along clines. Significant cubic clinal patterns were observed for adult static basal, hardened and dynamic heat knockdown time and static basal heat survival in larvae. In contrast, static, hardened larval heat survival increased linearly with latitude whereas no clinal association was found for larval ramping survival. Significant associations between adult and larval traits and climatic variables, and low population differentiation at microsatellite loci, suggest a role for climatic selection, rather than demographic processes, in generating these clinal patterns. Our results suggest that adaptation to thermal stress may be species and life-stage specific, complicating our efforts to understand the evolutionary responses to selection for increasing thermotolerance. PMID:22775577

  1. Options for state and local governments to regulate non-cigarette tobacco products.

    PubMed

    Freiberg, Michael

    2012-01-01

    Most tobacco control laws were written to address the scourge of smoking--particularly smoking cigarettes. As a result, these laws frequently exclude non-cigarette tobacco products, which are becoming more prevalent on the market. These regulatory gaps jeopardize public health by increasing the possibility that these products will be used--particularly by minors and young adults. This article examines gaps in regulation using five products as case studies: dissolvable tobacco products, electronic cigarettes, little cigars, snus, and water pipes. In addition, this article presents policy options that state and local governments can adopt to regulate these products more effectively, including regulations relating to price, flavors, youth access, use in public places, point-of-sale warnings, and marketing. Furthermore, this article contains extensive discussion of the recently adopted federal Family Smoking Prevention and Tobacco Control Act, which both limits and expands the power of state and local governments. PMID:22606921

  2. Rejection of waste heat from oxygen liquefaction operations at a lunar oxygen production plant

    NASA Astrophysics Data System (ADS)

    Linsley, J. N.; Jenson, E. B.

    Oxygen liquefaction is a key processing step of proposed lunar oxygen production plants. A baseline oxygen liquefaction process has been developed. The process operates continuously with a production rate of 200 tonnes per year. Oxygen is liquefied using a cascade refrigeration scheme in which methane and ethane refrigeration loops are used to increase the rejection temperature to 270 K. Heat is transferred from three process coolers to a utility cooling fluid and subsequently rejected by conduction to the lunar subsurface. An initial subsurface regolith exchanger consists of smooth tubes buried horizontally at a depth of about 2 m. A heat transfer analysis is performed to determine approximations for the spacing required between parallel tubes and the required heat exchange area.

  3. Indomethacin and ibuprofen induce Hsc70 nuclear localization and activation of the heat shock response in HeLa cells.

    PubMed

    Lagunas, Lucio; Bradbury, C Matthew; Laszlo, Andrei; Hunt, Clayton R; Gius, David

    2004-01-23

    It has been established that non-steroidal anti-inflammatory drugs (NSAIDs), such as sodium salicylate, sulindac, ibuprofen, and indomethacin, induce anti-inflammatory and anti-proliferative effects independent of cyclooxygenase. These cyclooxygenase-independent pharmacodynamic effects appear to regulate several signaling pathways involving proliferation, apoptosis, and heat shock response. However, the mechanisms of these actions remain an area of ongoing investigation. Hsc70 is a cytoplasmic chaperone protein involved in folding and trafficking of client proteins to different subcellular compartments, plays roles in signal transduction and apoptosis processes, and translocates to the nucleus following exposure to heat shock. Since NSAIDs induce some aspects of the heat shock response, we hypothesized that they may also induce Hsc70 nuclear translocation. Western immunoblotting and indirect cellular immunofluorescence showed that indomethacin and ibuprofen induce Hsc70 nuclear translocation at concentrations previously shown to induce HSF DNA-binding activity. Chemical inhibition of both p38(MAPK) and Erk42/44 had no effect on localization patterns. In addition, while indomethacin has been shown to behave as an oxidative stressor, the radical scavenging agent, N-acetyl cysteine, did not inhibit nuclear translocation. These results indicate that induction of the heat shock response by NSAIDs occurs at concentrations fivefold greater than those required to inhibit cyclooxygenase activity, suggesting a cyclooxygenase-independent mechanism, and in the presence or absence of kinase inhibitors and a free radical scavenger, suggesting independence of Erk42/44 or p38(MAPK) activities and intracellular oxidoreductive state. PMID:14706622

  4. Production and localization of beta-fructosidase in asynchronous and synchronous chemostat cultures of yeasts.

    PubMed Central

    Rouwenhorst, R J; van der Baan, A A; Scheffers, W A; Van Dijken, J P

    1991-01-01

    In synchronized continuous cultures of Saccharomyces cerevisiae CBS 8066, the production of the extracellular invertase (EC 3.2.1.26) showed a cyclic behavior that coincided with the budding cycle. The invertase activity increased during bud development and ceased at bud maturation and cell scission. The cyclic changes in invertase production resulted in cyclic changes in amounts of invertase localized in the cell wall. However, the amount of enzyme invertase present in the culture liquid remained constant throughout the budding cycle. Also, in asynchronous continuous cultures of S. cerevisiae, the production and localization of invertase showed significant fluctuation. The overall invertase production in an asynchronous culture was two to three times higher than in synchronous cultures. This could be due to more-severe invertase-repressive conditions in a synchronous chemostat culture. Both the intracellular glucose-6-phosphate concentration and residual glucose concentration were significantly higher in synchronous chemostat cultures than in asynchronous chemostat cultures. In the asynchronous and synchronous continuous cultures of S. cerevisiae, about 40% of the invertase was released into the culture liquid; it has generally been believed that S. cerevisiae releases only about 5% of its invertase. In contrast to invertase production and localization in the chemostat cultures of S. cerevisiae, no significant changes in inulinase (EC 3.2.1.7) production and localization were observed in chemostat cultures of Kluyveromyces maxianus CBS 6556. In cultures of K. marxianus about 50% of the inulinase was present in the culture liquid. PMID:2014991

  5. Volatile production during preignition heating. Final technical report, 15 September 1980-30 September 1982

    SciTech Connect

    Ballantyne, A.; Chou, H.; Flusberg, A.; Neoh, K.; Orozco, N.; Stickler, D.

    1983-10-01

    Pulverized coal particles, in a flowing inert nitrogen stream, have been heated by high power Carbon Dioxide Laser. The consequence of such an irradiation have proved to be both novel and surprising as a result of the rapid quenching of primary coal products. It ahs been found that the gas phase yield from such heating (typically, temperatures in excess of 1400 K at rates approx. 2 x 10/sup 5/ K/s) is very small (< 0.2 percent of coal carbon and hydrogen). Analysis of the solid residue has shown the presence of fine lacy particulate chains of material of 0.1 ..mu..m diameter, which appears to be soluble in tetrahydrofuran. The yields of solute were significantly much higher than for raw coals. Molecular weight of the solute material was high, being in the range of 600 to 3000. The above and substantiating evidence point to a new mechanism of high heating rate pyrolysis in which only tar-like materials are produced as primary products from the coal. It is hypothesized that gas phase products are primarily the result of secondary reactions of these primary products in the hot gas environments usually employed by other heating techniques.

  6. Assessment of heat treatment of dairy products by MALDI-TOF-MS.

    PubMed

    Meltretter, Jasmin; Birlouez-Aragon, Ins; Becker, Cord-Michael; Pischetsrieder, Monika

    2009-12-01

    The formation of the Amadori product from lactose (protein lactosylation) is a major parameter to evaluate the quality of processed milk. Here, MALDI-TOF-MS was used for the relative quantification of lactose-adducts in heated milk. Milk was heated at a temperature of 70, 80, and 100 degrees C between 0 and 300 min, diluted, and subjected directly to MALDI-TOF-MS. The lactosylation rate of alpha-lactalbumin increased with increasing reaction temperature and time. The results correlated well with established markers for heat treatment of milk (concentration of total soluble protein, soluble alpha-lactalbumin and beta-lactoglobulin at pH 4.6, and fluorescence of advanced Maillard products and soluble tryptophan index; r=0.969-0.997). The method was also applied to examine commercially available dairy products. In severely heated products, protein pre-purification by immobilized metal affinity chromatography improved spectra quality. Relative quantification of protein lactosylation by MALDI-TOF-MS proved to be a very fast and reliable method to monitor early Maillard reaction during milk processing. PMID:19760680

  7. Alteration of fasting heat production during fescue toxicosis in Holstein steers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study was designed to examine alteration of fasting heat production (FHP) during fescue toxicosis. Six ruminally cannulated Holstein steers (BW=348 ±13 kg) were weight-matched into pairs and utilized in a two period crossover design experiment. Each period consisted of two temperature segments,...

  8. TEMPERATURE-HUMIDITY INDICES AS INDICATORS OF MILK PRODUCTION LOSSES DUE TO HEAT STRESS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Meteorological data (1993 to 2004) from two public weather stations in Phoenix, AZ and Athens, GA were analyzed with test day milk yield data from herds nearby the weather stations to identify the most appropriate temperature humidity index (THI) to measure losses in milk production due to heat stre...

  9. Heat unit availability for cotton production in the Ogallala Aquifer Region of the United States

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Expansion in cotton (Gossypium hirsutum L.) production in the Ogallala Aquifer Region can be tied to early maturing varieties, rising energy costs, and declining water levels in the Ogallala Aquifer. However, the feasibility of growing cotton considering the availability of heat units in this region...

  10. Heat and moisture production of growing-finishing barrows as affected by environmental temperature

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Heat and moisture production measurements were completed on barrows over the normal weight range of 60 to 120 kg and a temperature range of 16 to 32°C. All measurements were based on a 21-hr period and adjusted to a 24-hr base. Animals were acclimated to treatment temperatures for 2 weeks, and the...

  11. 24 CFR 200.950 - Building product standards and certification program for solar water heating system.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 24 Housing and Urban Development 2 2010-04-01 2010-04-01 false Building product standards and certification program for solar water heating system. 200.950 Section 200.950 Housing and Urban Development Regulations Relating to Housing and Urban Development (Continued) OFFICE OF ASSISTANT SECRETARY FOR HOUSING-FEDERAL HOUSING...

  12. Simulation of magmatic and metamorphic fluid production coupled with deformation, fluid flow and heat transport

    NASA Astrophysics Data System (ADS)

    Sheldon, Heather A.

    2009-11-01

    A methodology for simulating magmatic and metamorphic fluid production coupled with mechanical deformation, fluid flow and heat transport is presented. The methodology is implemented in FLAC3D, a lagrangian finite difference code designed for simulation of coupled deformation, fluid flow and heat transport in porous media. The rate of metamorphic fluid production is governed by the rate of temperature change and an approximation of the variation in bound water content of appropriate lithologies with temperature. Magmatic fluid production is governed by the rate of cooling and the variation in free water content of a mafic granitic magma with temperature. Changes in porosity and fluid pressure due to fluid production, deformation, and thermal expansion are taken into account. Dilation associated with thermal expansion and fluid production leads to rotation of the principal stresses around fluid source regions. Fluid properties are calculated using an equation of state for pure water. The methodology has been applied to examples representing aspects of Archaean gold mineralisation in Western Australia, providing insight into the role of magmatic and metamorphic fluids in mineralisation, and effects arising from interactions between deformation, heat transport and fluid production.

  13. Local heat transfer in turbine disk-cavities. II - Rotor cooling with radial location injection of coolant

    NASA Astrophysics Data System (ADS)

    Bunker, R. S.; Metzger, D. E.; Wittig, S.

    1990-06-01

    The detailed radial distributions of rotor heat-transfer coefficients for three basic disk-cavity geometries applicable to gas turbines are presented. The coefficients are obtained over a range of parameters including disk rotational Reynolds numbers of 200,000 to 50,000, rotor/stator spacing-to-disk ratios of 0.025 to 0.15, and jet mass flow rates between 0.10 and 0.40 times the turbulent pumped flow rate of a free disk. The effects of a parallel rotor are analyzed, and strong variations in local Nusselt numbers for all but the rotational speed are pointed out and compared with the associated hub-injection data from a previous study. It is demonstrated that the overall rotor heat transfer is optimized by either the hub injection or radial location injection of a coolant, dependent on the configuration.

  14. Muscle heat production and anaerobic energy turnover during repeated intense dynamic exercise in humans

    PubMed Central

    Krustrup, Peter; Gonzlez-Alonso, Jos; Quistorff, Bjrn; Bangsbo, Jens

    2001-01-01

    The aim of the present study was to examine muscle heat production, oxygen uptake and anaerobic energy turnover throughout repeated intense exercise to test the hypotheses that (i) energy turnover is reduced when intense exercise is repeated and (ii) anaerobic energy production is diminished throughout repeated intense exercise. Five subjects performed three 3 min intense one-legged knee-extensor exercise bouts (EX1, EX2 and EX3) at a power output of 65 5 W (mean s.e.m.), separated by 6 min rest periods. Muscle, femoral arterial and venous temperatures were measured continuously during exercise for the determination of muscle heat production. In addition, thigh blood flow was measured and femoral arterial and venous blood were sampled frequently during exercise for the determination of muscle oxygen uptake. Anaerobic energy turnover was estimated as the difference between total energy turnover and aerobic energy turnover. Prior to exercise, the temperature of the quadriceps muscle was passively elevated to 37.02 0.12 C and it increased 0.97 0.08 C during EX1, which was higher (P < 0.05) than during EX2 (0.79 0.05 C) and EX3 (0.77 0.06 C). In EX1 the rate of muscle heat accumulation was higher (P < 0.05) during the first 120 s compared to EX2 and EX3, whereas the rate of heat release to the blood was greater (P < 0.05) throughout EX2 and EX3 compared to EX1. The rate of heat production, determined as the sum of heat accumulation and release, was the same in EX1, EX2 and EX3, and it increased (P < 0.05) from 86 8 during the first 15 s to 157 7 J s?1 during the last 15 s of EX1. Oxygen extraction was higher during the first 60 s of EX2 and EX3 than in EX 1 and thigh oxygen uptake was elevated (P < 0.05) during the first 120 s of EX2 and throughout EX3 compared to EX1. The anaerobic energy production during the first 105 s of EX2 and 150 s of EX3 was lower (P < 0.05) than in EX1. The present study demonstrates that when intense exercise is repeated muscle heat production is not changed, but muscle aerobic energy turnover is elevated and anaerobic energy production is reduced during the first minutes of exercise. PMID:11691886

  15. Locally indistinguishable subspaces spanned by three-qubit unextendible product bases

    SciTech Connect

    Duan Runyao; Ying Mingsheng; Xin Yu

    2010-03-15

    We study the local distinguishability of general multiqubit states and show that local projective measurements and classical communication are as powerful as the most general local measurements and classical communication. Remarkably, this indicates that the local distinguishability of multiqubit states can be decided efficiently. Another useful consequence is that a set of orthogonal n-qubit states is locally distinguishable only if the summation of their orthogonal Schmidt numbers is less than the total dimension 2{sup n}. Employing these results, we show that any orthonormal basis of a subspace spanned by arbitrary three-qubit orthogonal unextendible product bases (UPB) cannot be exactly distinguishable by local operations and classical communication. This not only reveals another intrinsic property of three-qubit orthogonal UPB but also provides a class of locally indistinguishable subspaces with dimension 4. We also explicitly construct locally indistinguishable subspaces with dimensions 3 and 5, respectively. Similar to the bipartite case, these results on multipartite locally indistinguishable subspaces can be used to estimate the one-shot environment-assisted classical capacity of a class of quantum broadcast channels.

  16. Kinetic-freezing and unfreezing of local-region fluctuations in a glass structure observed by heat capacity hysteresis

    SciTech Connect

    Aji, D. P. B.; Johari, G. P.

    2015-06-07

    Fluctuations confined to local regions in the structure of a glass are observed as the Johari-Goldstein (JG) relaxation. Properties of these regions and their atomic configuration are currently studied by relaxation techniques, by electron microscopy, and by high-energy X-ray scattering and extended x-ray absorption fine structure methods. One expects that these fluctuations (i) would kinetically freeze on cooling a glass, and the temperature coefficient of its enthalpy, dH/dT, would consequently show a gradual decrease with decrease in T, (ii) would kinetically unfreeze on heating the glass toward the glass-liquid transition temperature, T{sub g}, and dH/dT would gradually increase, and (iii) there would be a thermal hysteresis indicating the time and temperature dependence of the enthalpy. Since no such features have been found, thermodynamic consequences of these fluctuations are debated. After searching for these features in glasses of different types, we found it in one of the most stable metal alloy glasses of composition Pd{sub 40}Ni{sub 10}Cu{sub 30}P{sub 20}. On cooling from its T{sub g}, dH/dT decreased along a broad sigmoid-shape path as local-region fluctuations kinetically froze. On heating thereafter, dH/dT increased along a similar path as these fluctuations unfroze, and there is hysteresis in the cooling and heating paths, similar to that observed in the T{sub g}-endotherm range. After eliminating other interpretations, we conclude that local-region fluctuations seen as the JG relaxation in the non-equilibrium state of a glass contribute to its entropy, and we suggest conditions under which such fluctuations may be observed.

  17. Kinetic-freezing and unfreezing of local-region fluctuations in a glass structure observed by heat capacity hysteresis

    NASA Astrophysics Data System (ADS)

    Aji, D. P. B.; Johari, G. P.

    2015-06-01

    Fluctuations confined to local regions in the structure of a glass are observed as the Johari-Goldstein (JG) relaxation. Properties of these regions and their atomic configuration are currently studied by relaxation techniques, by electron microscopy, and by high-energy X-ray scattering and extended x-ray absorption fine structure methods. One expects that these fluctuations (i) would kinetically freeze on cooling a glass, and the temperature coefficient of its enthalpy, dH/dT, would consequently show a gradual decrease with decrease in T, (ii) would kinetically unfreeze on heating the glass toward the glass-liquid transition temperature, Tg, and dH/dT would gradually increase, and (iii) there would be a thermal hysteresis indicating the time and temperature dependence of the enthalpy. Since no such features have been found, thermodynamic consequences of these fluctuations are debated. After searching for these features in glasses of different types, we found it in one of the most stable metal alloy glasses of composition Pd40Ni10Cu30P20. On cooling from its Tg, dH/dT decreased along a broad sigmoid-shape path as local-region fluctuations kinetically froze. On heating thereafter, dH/dT increased along a similar path as these fluctuations unfroze, and there is hysteresis in the cooling and heating paths, similar to that observed in the Tg-endotherm range. After eliminating other interpretations, we conclude that local-region fluctuations seen as the JG relaxation in the non-equilibrium state of a glass contribute to its entropy, and we suggest conditions under which such fluctuations may be observed.

  18. Local heat transfer distribution in a square channel with 90 continuous, 90 saw tooth profiled and 60 broken ribs

    SciTech Connect

    Gupta, Abhishek; SriHarsha, V.; Prabhu, S.V.; Vedula, R.P.

    2008-02-15

    Internal channel cooling is employed in advanced gas turbines blade to allow high inlet temperatures so as to achieve high thrust/weight ratios and low specific fuel consumption. The objective of the present study is to measure the local heat transfer distributions in a double wall ribbed square channel with 90 continuous, 90 saw tooth profiled and 60 V-broken ribs. Comparison is made between the 90 continuous ribs (P/e = 7 and 10 for a e/D = 0.15) and 90 saw tooth profiled rib configurations (P/e = 7 for an e/D = 0.15) for the same rib height to the hydraulic diameter ratio (e/D). The effect of pitch to rib height ratio (P/e = 7.5,10 and 12) of 60 V-broken ribbed channel with a constant rib height to hydraulic diameter ratio (e/D) of 0.0625 on the local heat transfer distribution is studied. The Reynolds number based on duct hydraulic diameter is ranging from 10,000 to 30,000. A thin stainless steel foil of 0.05 mm thickness is used as heater and infrared thermography technique is used to obtain the local temperature distribution on the surface. The images are captured in the periodically fully developed region of the channel. It is observed that the heat transfer augmentations in the channel with 90 saw tooth profiled ribs are comparable with those of 90 continuous ribs. The enhancements caused by 60 V-broken ribs are higher than those of 90 continuous ribs. The effect of pitch to the rib height ratio (P/e) is not significant for channel with 60 V-broken ribs for a given rib height to hydraulic diameter ratio (e/D = 0.0625). (author)

  19. Kinetic-freezing and unfreezing of local-region fluctuations in a glass structure observed by heat capacity hysteresis.

    PubMed

    Aji, D P B; Johari, G P

    2015-06-01

    Fluctuations confined to local regions in the structure of a glass are observed as the Johari-Goldstein (JG) relaxation. Properties of these regions and their atomic configuration are currently studied by relaxation techniques, by electron microscopy, and by high-energy X-ray scattering and extended x-ray absorption fine structure methods. One expects that these fluctuations (i) would kinetically freeze on cooling a glass, and the temperature coefficient of its enthalpy, dH/dT, would consequently show a gradual decrease with decrease in T, (ii) would kinetically unfreeze on heating the glass toward the glass-liquid transition temperature, Tg, and dH/dT would gradually increase, and (iii) there would be a thermal hysteresis indicating the time and temperature dependence of the enthalpy. Since no such features have been found, thermodynamic consequences of these fluctuations are debated. After searching for these features in glasses of different types, we found it in one of the most stable metal alloy glasses of composition Pd40Ni10Cu30P20. On cooling from its Tg, dH/dT decreased along a broad sigmoid-shape path as local-region fluctuations kinetically froze. On heating thereafter, dH/dT increased along a similar path as these fluctuations unfroze, and there is hysteresis in the cooling and heating paths, similar to that observed in the Tg-endotherm range. After eliminating other interpretations, we conclude that local-region fluctuations seen as the JG relaxation in the non-equilibrium state of a glass contribute to its entropy, and we suggest conditions under which such fluctuations may be observed. PMID:26049502

  20. Characterization of microstructure, local deformation and microchemistry in Alloy 690 heat-affected zone and stress corrosion cracking in high temperature water

    NASA Astrophysics Data System (ADS)

    Lu, Zhanpeng; Chen, Junjie; Shoji, Tetsuo; Takeda, Yoichi; Yamazaki, Seiya

    2015-10-01

    With increasing the distance from the weld fusion line in an Alloy 690 heat-affected zone, micro-hardness decreases, kernel average misorientation decreases and the fraction of Σ3 boundaries increases. Chromium depletion at grain boundaries in the Alloy 690 heat-affected zone is less significant than that in an Alloy 600 heat-affected zone. Alloy 690 heat-affected zone exhibits much higher IGSCC resistance than Alloy 600 heat-affected zone in simulated pressurized water reactor primary water. Heavily cold worked Alloy 690 exhibits localized intergranular stress corrosion cracking. The effects of metallurgical and mechanical properties on stress corrosion cracking in Alloy 690 are discussed.

  1. Stability of high-speed boundary layer on a sharp cone with localized wall heating or cooling

    NASA Astrophysics Data System (ADS)

    Soudakov, V. G.; Fedorov, A. V.; Egorov, I. V.

    2015-06-01

    A localized heating or cooling effect on stability and transition of the boundary layer flow on a sharp cone is analyzed at the Mach number 6. The mean flows are calculated using axisymmetric Navier-Stokes equations. The spatial linear stability analysis is performed for twodimensional (2D) disturbances related to the Mack second mode. The transition onset points are estimated using the eN method. In this framework, the heater or cooler may cause earlier or later transition depending on the choice of critical N-factor. Direct numerical simulations (DNS) of 2D wave propagating in the boundary layer are compared with stability results.

  2. Effect of rib angle on local heat/mass transfer distribution in a two-pass rib-roughened channel

    NASA Technical Reports Server (NTRS)

    Chandra, P. R.; Han, J. C.; Lau, S. C.

    1987-01-01

    The naphthalene sublimation technique is used to investigate the heat transfer characteristics of turbulent air flow in a two-pass channel. A test section that resembles the internal cooling passages of gas turbine airfoils is employed. The local Sherwood numbers on the ribbed walls were found to be 1.5-6.5 times those for a fully developed flow in a smooth square duct. Depending on the rib angle-of-attack and the Reynolds number, the average ribbed-wall Sherwood numbers were 2.5-3.5 times higher than the fully developed values.

  3. A local heat transfer analysis of lava cooling in the atmosphere: application to thermal diffusion-dominated lava flows

    NASA Astrophysics Data System (ADS)

    Neri, Augusto

    1998-05-01

    The local cooling process of thermal diffusion-dominated lava flows in the atmosphere was studied by a transient, one-dimensional heat transfer model taking into account the most relevant processes governing its behavior. Thermal diffusion-dominated lava flows include any type of flow in which the conductive-diffusive contribution in the energy equation largely overcomes the convective terms. This type of condition is supposed to be satisfied, during more or less extended periods of time, for a wide range of lava flows characterized by very low flow-rates, such as slabby and toothpaste pahoehoe, spongy pahoehoe, flow at the transition pahoehoe-aa, and flows from ephemeral vents. The analysis can be useful for the understanding of the effect of crust formation on the thermal insulation of the lava interior and, if integrated with adequate flow models, for the explanation of local features and morphologies of lava flows. The study is particularly aimed at a better knowledge of the complex non-linear heat transfer mechanisms that control lava cooling in the atmosphere and at the estimation of the most important parameters affecting the global heat transfer coefficient during the solidification process. The three fundamental heat transfer mechanisms with the atmosphere, that is radiation, natural convection, and forced convection by the wind, were modeled, whereas conduction and heat generation due to crystallization were considered within the lava. The magma was represented as a vesiculated binary melt with a given liquidus and solidus temperature and with the possible presence of a eutectic. The effects of different morphological features of the surface were investigated through a simplified description of their geometry. Model results allow both study of the formation in time of the crust and the thermal mushy layer underlying it, and a description of the behavior of the temperature distribution inside the lava as well as radiative and convective fluxes to the atmosphere. The analysis, performed by using parameters typical of Etnean lavas, particularly focuses on the non-intuitive relations between superficial cooling effects and inner temperature distribution as a function of the major variables involved in the cooling process. Results integrate recent modelings and measurements of the cooling process of Hawaiian pahoehoe flow lobes by Hon et al. (1994) and Keszthelyi and Denlinger (1996) and highlight the critical role played by surface morphology, lava thermal properties, and crystallization dynamics. Furthermore, the reported description of the various heat fluxes between lava and atmosphere can be extended to any other type of lava flows in which atmospheric cooling is involved.

  4. Effects of heating rate on slow pyrolysis behavior, kinetic parameters and products properties of moso bamboo.

    PubMed

    Chen, Dengyu; Zhou, Jianbin; Zhang, Qisheng

    2014-10-01

    Effects of heating rate on slow pyrolysis behaviors, kinetic parameters, and products properties of moso bamboo were investigated in this study. Pyrolysis experiments were performed up to 700 C at heating rates of 5, 10, 20, and 30 C/min using thermogravimetric analysis (TGA) and a lab-scale fixed bed pyrolysis reactor. The results show that the onset and offset temperatures of the main devolatilization stage of thermogravimetry/derivative thermogravimetry (TG/DTG) curves obviously shift toward the high-temperature range, and the activation energy values increase with increasing heating rate. The heating rate has different effects on the pyrolysis products properties, including biochar (element content, proximate analysis, specific surface area, heating value), bio-oil (water content, chemical composition), and non-condensable gas. The solid yields from the fixed bed pyrolysis reactor are noticeably different from those of TGA mainly because the thermal hysteresis of the sample in the fixed bed pyrolysis reactor is more thorough. PMID:25063973

  5. Determination of the position of a localized heat source within a chirped fibre Bragg grating using a Fourier transform technique

    NASA Astrophysics Data System (ADS)

    Nand, Anbhawa; Kitcher, Daniel J.; Wade, Scott A.; Nguyen, Thinh B.; Baxter, Greg W.; Jones, Rhys; Collins, Stephen F.

    2006-06-01

    The ability to determine the centre position of a localized temperature change within a chirped fibre Bragg grating (CFBG) has been investigated as a function of grating strength. The intragrating sensor is based on the analysis of reflected power spectra arising from a CFBG. The technique uses a discrete Fourier transform (FFT) in which the measured spectrum of the CFBG due to a localized temperature change (heat source) was simulated using a FFT grating design model. The model operated on the reference spectrum and hypothesis temperature distributions, T(z), to generate a spectrum of a CFBG subjected to a hypothesis temperature disturbance. The simulated spectrum was fitted to the measured spectrum using a three-parameter automatic disturbance function fitting algorithm operating on position, width and amplitude of temperature change. RMS deviations to within 0.03 mm of applied values of position have been obtained.

  6. Thomson scattering diagnostics of thermal plasmas: Laser heating of electrons and the existence of local thermodynamic equilibrium.

    PubMed

    Murphy, A B

    2004-01-01

    A number of assessments of electron temperatures in atmospheric-pressure arc plasmas using Thomson scattering of laser light have recently been published. However, in this method, the electron temperature is perturbed due to strong heating of the electrons by the incident laser beam. This heating was taken into account by measuring the electron temperature as a function of the laser pulse energy, and linearly extrapolating the results to zero pulse energy to obtain an unperturbed electron temperature. In the present paper, calculations show that the laser heating process has a highly nonlinear dependence on laser power, and that the usual linear extrapolation leads to an overestimate of the electron temperature, typically by 5000 K. The nonlinearity occurs due to the strong dependence on electron temperature of the absorption of laser energy and of the collisional and radiative cooling of the heated electrons. There are further problems in deriving accurate electron temperatures from laser scattering due to necessary averages that have to be made over the duration of the laser pulse and over the finite volume from which laser light is scattered. These problems are particularly acute in measurements in which the laser beam is defocused in order to minimize laser heating; this can lead to the derivation of electron temperatures that are significantly greater than those existing anywhere in the scattering volume. It was concluded from the earlier Thomson scattering measurements that there were significant deviations from equilibrium between the electron and heavy-particle temperatures at the center of arc plasmas of industrial interest. The present calculations indicate that such deviations are only of the order of 1000 K in 20 000 K, so that the usual approximation that arc plasmas are approximately in local thermodynamic equilibrium still applies. PMID:14995726

  7. Results from the Phoenix Urban Heat Island (UHI) experiment: effects at the local, neighbourhood and urban scales

    NASA Astrophysics Data System (ADS)

    di Sabatino, S.; Leo, L. S.; Hedquist, B. C.; Carter, W.; Fernando, H. J. S.

    2009-04-01

    This paper reports on the analysis of results from a large urban heat island experiment (UHI) performed in Phoenix (AZ) in April 2008. From 1960 to 2000, the city of Phoenix experienced a minimum temperature rise of 0.47 C per decade, which is one of the highest rates in the world for a city of this size (Golden, 2004). Contemporaneously, the city has recorded a rapid enlargement and large portion of the land and desert vegetation have been replaced by buildings, asphalt and concrete (Brazel et al., 2007, Emmanuel and Fernando, 2007). Besides, model predictions show that minimum air temperatures for Phoenix metropolitan area in future years might be even higher than 38 C. In order to make general statements and mitigation strategies of the UHI phenomenon in Phoenix and other cities in hot arid climates, a one-day intensive experiment was conducted on the 4th-5th April 2008 to collect surface and ambient temperatures within various landscapes in Central Phoenix. Inter alia, infrared thermography (IRT) was used for UHI mapping. The aim was to investigate UHI modifications within the city of Phoenix at three spatial scales i.e. the local (Central Business District, CBD), the neighborhood and the city scales. This was achieved by combining IRT measurements taken at ground level by mobile equipment (automobile-mounted and pedicab) and at high elevation by a helicopter. At local scale detailed thermographic images of about twenty building faades and several street canyons were collected. In total, about two thousand images were taken during the 24-hour campaign. Image analysis provides detailed information on building surface and pavement temperatures at fine resolution (Hedquist et al. 2009, Di Sabatino et al. 2009). This unique dataset allows us several investigations on local air temperature dependence on albedo, building thermal inertia, building shape and orientation and sky view factors. Besides, the mosaic of building faade temperatures are being analyzed in terms of local buoyancy fluxes and possible wind flow modifications by such thermally driven flows will be elucidated. The results are of consequence for understanding microclimate of large cities in order to derive urbanizations schemes for numerical models and to set-up suitable heat mitigation strategies. REFERENCES Brazel, AJ, Gober, P., Lee, S., Grossman-Clarke, S., Zehnder, J., Hedquist, B. and Comparri, E 2007: Dynamics and determinants of urban heat island change (1990-2004) with Phoenix, Arizona, USA. Climate Research 33, 171-182. Di Sabatino S, Hedquist BC, Carter W, Leo LS, Fernando HJS. 2009. Phoenix urban heat island experiment: effects of built elements. Proceedings of the Eighth Symposium on the Urban Environment, Phoenix, Arizona. Emmanuel, R. and Fernando HJS 2007: Effects of urban form and thermal properties in urban heat island mitigation in hot humid and hot arid climates: The cases of Colombo, Sri Lanka and Phoenix, USA. Climate Research 34, 241-251. Golden JS. 2004. The built environment induced urban heat island in rapidly urbanizing arid regions: a sustainable urban engineering complexity. Environmental Sciences 1(4):321-349. Hedquist, BC, Brazel, AJ, Di Sabatino, S., Carter, W. and Fernando, HJS 2009: Phoenix urban heat island experiment: micrometeorological aspects. Proceedings of the Eighth Symposium on the Urban Environment, Phoenix, Arizona.

  8. Modeling the Daly Gap: The Influence of Latent Heat Production in Controlling Magma Extraction and Eruption

    NASA Astrophysics Data System (ADS)

    Nelson, B. K.; Ghiorso, M. S.; Bachmann, O.; Dufek, J.

    2011-12-01

    A century-old issue in volcanology is the origin of the gap in chemical compositions observed in magmatic series on ocean islands and arcs - the "Daly Gap". If the gap forms during differentiation from a mafic parent, models that predict the dynamics of magma extraction as a function of chemical composition must simulate a process that results in volumetrically biased, bimodal compositions of erupted magmas. The probability of magma extraction is controlled by magma dynamical processes, which have a complex response to magmatic heat evolution. Heat loss from the magmatic system is far from a simple, monotonic function of time. It is modified by the crystallization sequence, chamber margin heat flux, and is buffered by latent heat production. We use chemical and thermal calculations of MELTS (Ghiorso & Sack, 1995) as input to the physical model of QUANTUM (Dufek & Bachmann, 2010) to predict crystallinity windows of most probable magma extraction. We modeled two case studies: volcanism on Tenerife, Canary Islands, and the Campanian Ignimbrite (CI) of Campi Flegrei, Italy. Both preserve a basanitic to phonolitic lineage and have comparable total alkali concentrations; however, CI has high and Tenerife has low K2O/Na2O. Modeled thermal histories of differentiation for the two sequences contrast strongly. In Tenerife, the rate of latent heat production is almost always greater than sensible heat production, with spikes in the ratio of latent to sensible heats of up to 40 associated with the appearance of Fe-Ti oxides at near 50% crystallization. This punctuated heat production must cause magma temperature change to stall or slow in time. The extended time spent at ≈50% crystallinity, associated with dynamical processes that enhance melt extraction near 50% crystallinity, suggests the magma composition at this interval should be common. In Tenerife, the modeled composition coincides with that of the first peak in the bimodal frequency-composition distribution. In our model, we move the extracted liquid to a shallower chamber (1.5 kbar as inferred for Tenerife phonolite) and resume crystallization. At the optimal magma extraction window of ≈50% crystallinity, the composition matches well with the observed composition of the second peak of the bimodal distribution. In contrast, CI does not show an early spike in latent heat production, but a late (≈900°C) pseudo-invariant point where latent heat production spikes. This spike is very near the 50% crystallinity window, again enhancing the probability of magma extraction. The model liquid composition at this crystallinity matches the observed trachyte composition. In both systems, phase chemistry supports a two-chamber evolution, one deep and the second shallow, corresponding to two primary melt extraction events. Realistically incorporating chemical, thermal and physical processes in magma chamber models provides composition-volume estimates of extracted magma that coincide with observed bimodal composition-volume relations. The strong variability in latent heat production is an important control, and its characterization is central to physical models of magma chamber evolution.

  9. Joule-Heated Molten Regolith Electrolysis Reactor Concepts for Oxygen and Metals Production on the Moon and Mars

    NASA Technical Reports Server (NTRS)

    Sibille, Laurent; Dominques, Jesus A.

    2012-01-01

    The maturation of Molten Regolith Electrolysis (MRE) as a viable technology for oxygen and metals production on explored planets relies on the realization of the self-heating mode for the reactor. Joule heat generated during regolith electrolysis creates thermal energy that should be able to maintain the molten phase (similar to electrolytic Hall-Heroult process for aluminum production). Self-heating via Joule heating offers many advantages: (1) The regolith itself is the crucible material, it protects the vessel walls (2) Simplifies the engineering of the reactor (3) Reduces power consumption (no external heating) (4) Extends the longevity of the reactor. Predictive modeling is a tool chosen to perform dimensional analysis of a self-heating reactor: (1) Multiphysics modeling (COMSOL) was selected for Joule heat generation and heat transfer (2) Objective is to identify critical dimensions for first reactor prototype.

  10. Numerical research of heat and mass transfer at the ignition of system "fabric - combustible liquid - oxidant" by the local energy source

    NASA Astrophysics Data System (ADS)

    Glushkov, Dmitrii O.; Kuznetsov, Genii V.; Strizhak, Pavel A.

    2015-01-01

    A numerical research was executed for macroscopic regularities determination of heat and mass transfer processes under the conditions of phase transformation and chemical reaction at the ignition of vapour coming from fabrics impregnated by typical combustible liquid into oxidant area at the local power supply. Limit conditions of heterogeneous system "fabric - combustible liquid - oxidant" ignition at the heating of single metal particle was established. Dependences of ignition delay time on temperature and rates of local power source were obtained.

  11. Farmers Market Brings Fresh Produce and Products from Local Vendors | Poster

    Cancer.gov

    By Carolynne Keenan, Guest Writer Every summer, you can shop for fresh fruits, veggies, flowers, honey, and plenty of other homemade goodies at the NCI at Frederick Farmers’ Market. Buying at the Farmers’ Market means you’re supporting a local farmer, crafter, or other type of vendor. The products are brought to you, so you don’t have to drive to get freshly picked produce and handmade products.

  12. In situ localization of heat-shock and histone proteins in honey-bee (Apis mellifera l.) larvae infected with Paenibacillus larvae.

    PubMed

    Gregorc, A; Bowen, I D

    1999-01-01

    The immunohistochemical localization of the heat shock proteins (Hsp70 and Hsp90) and histone protein in healthy and Paenibacillus larvae infected honeybee (Apis mellifera L.) larvae has been studied. Hsp70 was found in the nuclei and the cytoplasm of infected midgut, salivary gland cells and haemocytes, but not in uninfected larvae. Hsp90 was localized in both infected and uninfected cells. Exposed histone proteins were localized in the nuclei of dying uninfected cells undergoing programmed cell death. The distribution of histone protein in uninfected cells of midgut, salivary gland, and other tissues was nuclear and indicative of normal programmed cell death at levels between 1 and 5%. After applying histone protein antibodies to P. larvae infected honeybee larvae, the DAB based reaction product was located in the nuclei or immediate surroundings of all larval cells. The Hsp70, Hsp90 and histone protein distribution patterns are discussed in relation to the morphological, cytochemical and immunocytochemical characteristics of programmed cell death and pathological necrosis. Results produced by methyl green-pyronin staining confirm an elevation of RNA levels in normal programmed cell death and a reduced staining for RNA in necrotic infected cells. PMID:10562442

  13. Composite heat-insulating material and process for the production thereof

    SciTech Connect

    Yazaki, T.; Hattori, K.; Hattori, S.; Hayama, K.; Itoh, I.

    1985-02-19

    A composite heat-insulating material and a process for the production thereof are described. This material is of the structure that an olefin- or styrene-based resin sheet and a urethane foam material are laminated on each other with an adhesive containing: (A) 20 to 100% by weight of a water-soluble polyamine compound selected from the group consisting of polyethyleneimine, poly(ethyleneimine-urea), and a polyaminepolyamide/ethyleneimine adduct, and (B) 80 to 0% by weight of a nitrogen atom-containing cationic or amphoteric polymer. This composite heat-insulating material is very suitable for use as a lining material for a refrigerator, for example.

  14. Heat of Combustion of the Product Formed by the Reaction of Acetylene, Ethylene, and Diborane

    NASA Technical Reports Server (NTRS)

    Tannenbaum, Stanley

    1957-01-01

    The net heat of combustion of the product formed by the reaction of diborane with a mixture of acetylene and ethylene was found to be 20,440 +/- 150 Btu per pound for the reaction of liquid fuel to gaseous carbon dioxide, gaseous water, and solid boric oxide. The measurements were made in a Parr oxygen-bomb calorimeter, and the combustion was believed to be 98 percent complete. The estimated net-heat of combustion for complete combustion would therefore be 20,850 +/- 150 Btu per pound.

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

    SciTech Connect

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

    2011-02-01

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

  16. Effect of temperature and heating rate on apparent lethal concentrations of pyrolysis products

    NASA Technical Reports Server (NTRS)

    Hilado, C. J.; Solis, A. N.; Marcussen, W. H.; Furst, A.

    1976-01-01

    The apparent lethal concentrations for 50 percent of the test animals of the pyrolysis products from twelve polymeric materials were studied as a function of temperature and heating rate. The materials were polyethylene, nylon 6, ABS, polycarbonate, polyether sulfone, polyaryl sulfone, wool fabric, aromatic polyamide fabric, polychloroprene foam, polyvinyl fluoride film, Douglas fir, and red oak. The apparent lethal concentration values of most materials vary significantly with temperature and heating rate. The apparent lethal concentration values, based on weight of sample charged, appears to effectively integrate the thermophysical, thermochemical, and physiological responses from a known quantity of material under specified imposed conditions.

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

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

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

  18. Heat-resistance of Hamigera avellanea and Thermoascus crustaceus isolated from pasteurized acid products.

    PubMed

    Scaramuzza, Nicoletta; Berni, Elettra

    2014-01-01

    Products containing sugar or fruit derivatives are usually subjected to a pasteurization process that can anyway be ineffective to kill ascospores from heat-resistant molds. Although the most occurring and economically relevant heat-resistant species belong to Byssochlamys, Neosartorya, Talaromyces, and Eupenicillium genera, an increasing number of uncommon heat-resistant isolates have been recently detected as spoiling microorganisms in such products. Since Hamigera spp. and Thermoascus spp. were those more frequently isolated at SSICA, heat resistance of Hamigera avellanea and Thermoascus crustaceus strains from pasteurized acid products was studied in apple juice, in blueberry and grape juice and in a buffered glucose solution. Data obtained from thermal death curves and statistical elaboration of raw data showed that D values of H. avellanea may vary between 11.11 and 66.67 min at 87°C, between 4.67 and 13.51 at 90°C, and between 0.43 and 1.52 min at 95°C. Similarly, D values of T. crustaceus may vary between 18.52 and 90.91 min at 90°C, between 2.79 and 19.23 at 93°C, and between 1.11 and 2.53 min at 95°C. For both strains studied, the z-values calculated from the decimal reduction time curves did not prove to be significantly influenced by the heating medium, that being 4.35°C, 5.39°C or 5.27°C for H. avellanea and 4.42°C, 3.69°C or 3.37°C for T. crustaceus, respectively in apple juice, in blueberry and grape juice or in the buffered glucose solution. Considering the pasteurization treatments industrially applied to fruit-based foods, the variation of thermal parameters does not seem to be a possible way to avoid product spoilage by these two species and only good practices applied to reduce the original load of heat-resistant fungi can help producers to prevent losses in contaminated finished products, as usually happens for other heat resistant molds. PMID:24239977

  19. Comparison of the effects of millimeter wave irradiation, general bath heating, and localized heating on neuronal activity in the leech ganglion

    NASA Astrophysics Data System (ADS)

    Romanenko, Sergii; Siegel, Peter H.; Wagenaar, Daniel A.; Pikov, Victor

    2013-02-01

    The use of electrically-induced neuromodulation has grown in importance in the treatment of multiple neurological disorders such as Parkinson's disease, dystonia, epilepsy, chronic pain, cluster headaches and others. While electrical current can be applied locally, it requires placing stimulation electrodes in direct contact with the neural tissue. Our goal is to develop a method for localized application of electromagnetic energy to the brain without direct tissue contact. Toward this goal, we are experimenting with the wireless transmission of millimeter wave (MMW) energy in the 10-100 GHz frequency range, where penetration and focusing can be traded off to provide non-contact irradiation of the cerebral cortex. Initial experiments have been conducted on freshly-isolated leech ganglia to evaluate the real-time changes in the activity of individual neurons upon exposure to the MMW radiation. The initial results indicate that low-intensity MMWs can partially suppress the neuronal activity. This is in contrast to general bath heating, which had an excitatory effect on the neuronal activity. Further studies are underway to determine the changes in the state of the membrane channels that might be responsible for the observed neuromodulatory effects.

  20. Non-local Lateral electron heat transport from one or more hot spots.

    NASA Astrophysics Data System (ADS)

    Matte, Jean-Pierre; Alouani-Bibi, Fathallah

    2000-10-01

    Fokker-Planck simulations of collisional absorption and transport in long scale length, preformed, underdense plasmas heated by intense and narrow laser hot spots, as in certain recent LANL experiments [1], are presented. The temperature profiles compared with those obtained from flux limited or delocalized heat flow models. For the former, the temperature peaks can be matched only if a very low flux limiter is used, and even then, the scale length of the temperature profile is always overestimated. The electron distribution function will be characterized, and compared to the "DLM" shape, exp(-(v/u)^m), [2] and the best fit for m will be compared to older formulas for uniform plasmas [2]. Hydrodynamic effects are also addressed with simulations which include ion motion; both with and without the ponderomotive force. The enhancement of sound velocity due to the "DLM" shape [3] inside the hot spot will be quantified. [1] J.A. Cobble et al., Phys. Plasmas, 7, 323 (2000) [2] J.P. Matte et al., Plasma Phys. and Contr. Fusion, 30, 1665, (1988) [3] B. B. Afeyan et al., PRL 81, 2322 (1998).

  1. FEM simulation of local heating and melting during electrical discharge plasma impact

    NASA Astrophysics Data System (ADS)

    Lasagni, A.; Soldera, F.; Mcklich, F.

    2004-09-01

    The effect of an electrical discharge can be seen as an energy input into a material. This energy increases the material temperature within concentrated zones even over the boiling point producing the erosion of the material surface. In this paper, thermal analysis by a finite element method (FEM) and by using the analytical solution for the heat conduction problem in a semi-infinite solid subjected to a point source heat was carried out. The simulation includes the solid-liquid and liquid-vapour transformations, which facilitate the calculation of the volumes of the molten and vaporized materials. The simulation results were compared with the material loss due to individual sparks in several metallic electrodes at high pressure and room temperature. It was found that the volume of the molten pool is related to the volume of the eroded material, and therefore the material loss is practically controlled by the melting enthalpy and the melting point. Because of the linear relation between the eroded and molten pool volumes, it is possible to estimate the resistance to electrode erosion by calculating and comparing the volume of the molten pool with a reference metal.

  2. Local heat transfer distribution in a two-pass trapezoidal channel with a 180{degree} turn via the transient liquid crystal technique

    SciTech Connect

    Endley, S.; Yoon, C.; Lau, S.C.

    1999-07-01

    This experimental investigation studies the heat transfer characteristics of cooling airflows in serpentine channels in stator blades of gas turbines. The internal cooling channels are modeled as a smooth two-pass channel of trapezoidal cross section. Attention is focused on the effect of the 180{degree} turn on the local heat transfer distributions on the interior surfaces of the various walls at the turn, under turbulent flow conditions. Transient heat transfer experiments, using encapsulated thermochromic liquid crystals, are conducted to obtain the local distributions of the heat transfer coefficient on all the walls at the turn for various rates of airflow through the channel, corresponding to Reynolds numbers between 30,000 and 88,000. The heat transfer is, in general, much higher on the walls in the turn and downstream of the turn than on the walls upstream of the turn. The turn induces secondary flows that impinge on the end wall and the outlet outer wall, causing high heat transfer in several distinct regions on the walls. The flow separates at the tip of the middle wall and reattaches on the outlet inner wall in a region only a short distance from the turn. The heat transfer is the lowest on the inlet outer wall. Heat transfer enhancement due to the turn is the highest in the lowest Reynolds number case. The trends of the local heat transfer distributions on the various walls at the turn are relatively insensitive to varying the flow rate, over the range of Reynolds number studied.

  3. Use of a novel smart heating sleeping bag to improve wearers’ local thermal comfort in the feet

    PubMed Central

    Song, W. F.; Zhang, C. J.; Lai, D. D.; Wang, F. M.; Kuklane, K.

    2016-01-01

    Previous studies have revealed that wearers had low skin temperatures and cold and pain sensations in the feet, when using sleeping bags under defined comfort and limit temperatures. To improve wearers’ local thermal comfort in the feet, a novel heating sleeping bag (i.e., MARHT) was developed by embedding two heating pads into the traditional sleeping bag (i.e., MARCON) in this region. Seven female and seven male volunteers underwent two tests on different days. Each test lasted for three hours and was performed in a climate chamber with a setting temperature deduced from EN 13537 (2012) (for females: comfort temperature of −0.4 °C, and for males: the limit temperature of −6.4 °C). MARHT was found to be effective in maintaining the toe and feet temperatures within the thermoneutral range for both sex groups compared to the linearly decreased temperatures in MARCON during the 3-hour exposure. In addition, wearing MARHT elevated the toe blood flow significantly for most females and all males. Thermal and comfort sensations showed a large improvement in feet and a small to moderate improvement in the whole body for both sex groups in MARHT. It was concluded that MARHT is effective in improving local thermal comfort in the feet. PMID:26759077

  4. Use of a novel smart heating sleeping bag to improve wearers' local thermal comfort in the feet.

    PubMed

    Song, W F; Zhang, C J; Lai, D D; Wang, F M; Kuklane, K

    2016-01-01

    Previous studies have revealed that wearers had low skin temperatures and cold and pain sensations in the feet, when using sleeping bags under defined comfort and limit temperatures. To improve wearers' local thermal comfort in the feet, a novel heating sleeping bag (i.e., MARHT) was developed by embedding two heating pads into the traditional sleeping bag (i.e., MARCON) in this region. Seven female and seven male volunteers underwent two tests on different days. Each test lasted for three hours and was performed in a climate chamber with a setting temperature deduced from EN 13537 (2012) (for females: comfort temperature of -0.4?C, and for males: the limit temperature of -6.4?C). MARHT was found to be effective in maintaining the toe and feet temperatures within the thermoneutral range for both sex groups compared to the linearly decreased temperatures in MARCON during the 3-hour exposure. In addition, wearing MARHT elevated the toe blood flow significantly for most females and all males. Thermal and comfort sensations showed a large improvement in feet and a small to moderate improvement in the whole body for both sex groups in MARHT. It was concluded that MARHT is effective in improving local thermal comfort in the feet. PMID:26759077

  5. Field nano-localization of gas bubble production from water electrolysis

    NASA Astrophysics Data System (ADS)

    Hammadi, Z.; Morin, R.; Olives, J.

    2013-11-01

    Using a tip shaped electrode and ac voltages, we show that the production of micro bubbles of gas from water electrolysis is localized at the tip apex inside a domain in the voltage frequency phase space. A model taking into account the electrode shape and dimensions explains these results which suggest a field effect control of the electrolysis reaction rate at a nanometer scale.

  6. Deletion of muscle GRP94 impairs both muscle and body growth by inhibiting local IGF production

    PubMed Central

    Barton, Elisabeth R.; Park, SooHyun; James, Jose K.; Makarewich, Catherine A.; Philippou, Anastassios; Eletto, Davide; Lei, Hanqin; Brisson, Becky; Ostrovsky, Olga; Li, Zihai; Argon, Yair

    2012-01-01

    Insulin-like growth factors (IGFs) are critical for development and growth of skeletal muscles, but because several tissues produce IGFs, it is not clear which source is necessary or sufficient for muscle growth. Because it is critical for production of both IGF-I and IGF-II, we ablated glucose-regulated protein 94 (GRP94) in murine striated muscle to test the necessity of local IGFs for normal muscle growth. These mice exhibited smaller skeletal muscles with diminished IGF contents but with normal contractile function and no apparent endoplasmic reticulum stress response. This result shows that muscles rely on GRP94 primarily to support local production of IGFs, a pool that is necessary for normal muscle growth. In addition, body weights were ∼30% smaller than those of littermate controls, and circulating IGF-I also decreased significantly, yet glucose homeostasis was maintained with little disruption to the growth hormone pathway. The growth defect was complemented on administration of recombinant IGF-I. Thus, unlike liver production of IGF-I, muscle IGF-I is necessary not only locally but also globally for whole-body growth.—Barton, E. R., Park, S., James, J. K., Makarewich, C. A., Philippou, A., Eletto, D., Lei, H., Brisson, B., Ostrovsky, O., Li, Z., Argon, Y. Deletion of muscle GRP94 impairs both muscle and body growth by inhibiting local IGF production. PMID:22649033

  7. Microanalysis of the reaction product in Karnovsky and Roots histochemical localization of acetylcholinesterase

    SciTech Connect

    Tewari, J.P.; Sehgal, S.S.; Malhotra, S.K.

    1982-05-01

    X-ray energy dispersive microanalysis of the reaction product in Karnovsky and Roots histochemical localization of acetylcholinesterase indicated the presence of sulfur, iodine, copper, and iron. The reaction was run in vitro using purified acetylcholinesterase from the electric eel to confirm our previous results on similarly treated neuromuscular junction in situ.

  8. Analysis of Vertical Turbulent Heat Flux Limit in Stable Conditions with a Local Equilibrium, Turbulence Closure Model

    NASA Astrophysics Data System (ADS)

    ?obocki, Lech

    2013-09-01

    Assuming that the vertical turbulent heat flux vanishes at extremely stable conditions, one should expect its maximal absolute value to occur somewhere at moderate stability, between a neutral and extremely stable equilibrium. Consequently, in some situations duality of solutions may be encountered (e.g. two different values of temperature difference associated with the same values of heat flux and wind speed). A quantitative analysis of this feature with a local equilibrium Reynolds-stress model is presented. The fixed-wind / fixed-shear maximum has been identified both in the bulk and in single-point flux-gradient relationships (that is, in the vertical temperature gradient and wind-shear parameter domain). The value of the Richardson number corresponding to this maximum is derived from the model equations. To study the possible feedback in strongly stable conditions, weak and intense cooling scenarios have been simulated with a one-dimensional numerical, high-resolution atmospheric boundary-layer model. Despite the rapid cooling, flow decoupling at the surface has not been observed; instead, a stability-limited heat flux is maintained, with a gradual increase of the Richardson number towards the top of the turbulent layer, with some signs of oscillatory behaviour at intermediate heights. Vertical changes of wind shear and the Brunt-Visl frequency display a remarkably non-monotonic character, with some signs of a gradually developing instability.

  9. Millimeter Wave Detection of Localized Anomalies in the Space Shuttle External Fuel Tank Insulating Foam and Acreage Heat Tiles

    NASA Technical Reports Server (NTRS)

    Kharkovsky, S.; Case, J. T.; Zoughi, R.; Hepburn, F.

    2005-01-01

    The Space Shuttle Columbia's catastrophic accident emphasizes the growing need for developing and applying effective, robust and life-cycle oriented nondestructive testing (NDT) methods for inspecting the shuttle external fuel tank spray on foam insulation (SOFI) and its protective acreage heat tiles. Millimeter wave NDT techniques were one of the methods chosen for evaluating their potential for inspecting these structures. Several panels with embedded anomalies (mainly voids) were produced and tested for this purpose. Near-field and far-field millimeter wave NDT methods were used for producing millimeter wave images of the anomalies in SOFI panel and heat tiles. This paper presents the results of an investigation for the purpose of detecting localized anomalies in two SOFI panels and a set of heat tiles. To this end, reflectometers at a relatively wide range of frequencies (Ka-band (26.5 - 40 GHz) to W-band (75 - 110 GHz)) and utilizing different types of radiators were employed. The results clearly illustrate the utility of these methods for this purpose.

  10. Radionuclides behavior in induction heat melting and its products for non-combustible solid waste

    SciTech Connect

    Teshima, T.; Karita, Y.; Okamoto, O.; Ohno, H.

    1993-12-31

    Melting is one of the potential treatment methods for non-combustible waste based on its properties of solidified products, such as radionuclides confinement, mechanical strength, etc. The radionuclide behavior in induction heat melting and its products were examined, such as volatility, nuclide distribution in the product, and leachability in support of safety assessment of LLW disposal. Volatile nuclides such as C-14 and I-129 were confirmed to be released in off-gas in the melting operation. Cs-134 remained in the product. The other nuclides remaining in the product were confirmed to be distributed in metal and ceramic blocks, depending on the thermal properties of the nuclides. The leaching rate of the metal and ceramic blocks as measured to be adequate.

  11. Radioelements and heat production of an exposed Archaean crustal cross-section, Dharwar craton, south India

    NASA Astrophysics Data System (ADS)

    Kumar, P. Senthil; Reddy, G. K.

    2004-08-01

    The Dharwar craton (DC) in south India exposes a tilted ˜30-km-thick crustal section equivalent to upper, middle and lower Archaean continental crust. The DC is composed of poly-magmatic-metamorphic terrains such as the Western Dharwar Craton (WDC) and Eastern Dharwar Craton (EDC) whose contact is marked by the Closepet Granite batholith (CG). In-situ gamma-ray spectrometric analysis has been carried out to measure K, U and Th abundance at 1023 sites covering all major rock formations of the DC. The data show that the greenschist and amphibolite facies tonalite-trondhjemite-granodioritic (TTG) gneisses of the WDC are poorer in radioelements compared to granodioritic gneisses of the EDC. Similarly, the WDC granites of the amphibolite facies region have lower abundance indicating their derivation from a depleted lower crust, which had suffered an earlier crustal differentiation. The elemental data on the gneisses in the WDC and EDC do not show a difference between the greenschist and amphibolite facies, but there is a marked depletion in the granulite facies. The depletion reaches a maximum in the high- P granulites in the southernmost part of the DC. The elongate CG is an I-type, calc-alkaline, metaluminous granite, which exposes a ˜12-km-thick batholith, where K is remarkably uniform but U and Th show several fold increase with decreasing crustal levels. Heat production was calculated from the radioelemental data. For estimating the radiogenic heat contribution of crust to heat flow, we arrive at a present-day crustal configuration comprising four northerly dipping metamorphic facies layers: greenschist, amphibolite, metasomatized granulite and depleted granulite. Gross heat production of each layer is computed from heat production of constituent rocks and their abundance. The crustal contribution is found to decrease, from greenschist to granulite facies regions, from 23 to 18 mW m -2 in the WDC, 27 to 7 mW m -2 in the EDC. Surface heat flow and the crustal contribution models indicate that mantle heat flow of the WDC is lower (7-10 mW m -2) compared to the EDC (17-24 mW m -2) in the greenschist and amphibolite facies regions. High mantle heat flow of 29 mW m -2 beneath the depleted granulite facies region of the EDC appears anomalous in the Dharwar craton.

  12. Measurement of limiter heating due to fusion product losses during high fusion power deuterium-tritium operation of TFTR

    SciTech Connect

    Janos, A.; Owens, D.K.; Darrow, D.; Redi, M.; Zarnstorff, M.; Zweben, S.

    1995-03-01

    Preliminary analysis has been completed on measurements of limiter heating during high fusion power deuterium-tritium (D-T) operation of TFTR, in an attempt to identify heating from alpha particle losses. Recent operation of TFTR with a 50-50 mix of D-T has resulted in fusion power output ({approx} 6.2 MW) orders of magnitude above what was previously achieved on TFTR. A significantly larger absolute number of particles and energy from fusion products compared to D-D operation is expected to be lost to the limiters. Measurements were made in the vicinity of the midplane ({plus_minus} 30{degree}) with thermocouples mounted on the tiles of an outboard limiter. Comparisons were made -between discharges which were similar except for the mix of deuterium and tritium beam sources. Power and energy estimates of predicted alpha losses were as high as 0.13 MW and 64 kJ. Depending on what portion of the limiters absorbed this energy, temperature rises of up to 42 {degrees}C could be expected, corresponding to a heat load of 0.69 MJ/m{sup 2} over a 0.5 sec period, or a power load of 1.4 MW/m{sup 2}. There was a measurable increase in the limiter tile temperature as the fusion power yield increased with a more reactive mixture of D and T at constant beam power during high power D-T operation. Analysis of the data is being conducted to see if the alpha heating component can be extracted. Measured temperature increases were no greater than 1 {degree}C, indicating that there was probably neither an unexpectedly large fraction of lost particles nor unexpected localization of the losses. Limits on the stochastic ripple loss contribution from alphas can be deduced.

  13. Development of Naphthalene PLIF for Visualizing Ablation Products From a Space Capsule Heat Shield

    NASA Technical Reports Server (NTRS)

    Combs, C. S.; Clemens, N. T.; Danehy, P. M.

    2014-01-01

    The Orion Multi-Purpose Crew Vehicle (MPCV) will use an ablative heat shield. To better design this heat shield and others that will undergo planetary entry, an improved understanding of the ablation process would be beneficial. Here, a technique developed at The University of Texas at Austin that uses planar laser-induced fluorescence (PLIF) of a low-temperature sublimating ablator (naphthalene) to enable visualization of the ablation products in a hypersonic flow is applied. Although high-temperature ablation is difficult and expensive to recreate in a laboratory environment, low-temperature sublimation creates a limited physics problem that can be used to explore ablation-product transport in a hypersonic flow-field. In the current work, a subscale capsule reentry vehicle model with a solid naphthalene heat shield has been tested in a Mach 5 wind tunnel. The PLIF technique provides images of the spatial distribution of sublimated naphthalene in the heat-shield boundary layer, separated shear layer, and backshell recirculation region. Visualizations of the capsule shear layer using both naphthalene PLIF and Schlieren imaging compared favorably. PLIF images have shown high concentrations of naphthalene in the capsule separated flow region, intermittent turbulent structures on the heat shield surface, and interesting details of the capsule shear layer structure. It was shown that, in general, the capsule shear layer appears to be more unsteady at lower angels of attack. The PLIF images demonstrated that during a wind tunnel run, as the model heated up, the rate of naphthalene ablation increased, since the PLIF signal increased steadily over the course of a run. Additionally, the shear layer became increasingly unsteady over the course of a wind tunnel run, likely because of increased surface roughness but also possibly because of the increased blowing. Regions with a relatively low concentration of naphthalene were also identified in the capsule backshell recirculation region and are most likely the result of cross-flow-induced vortices on the capsule afterbody.

  14. Model predictive control of a combined heat and power plant using local linear models

    SciTech Connect

    Kikstra, J.F.; Roffel, B.; Schoen, P.

    1998-10-01

    Model predictive control has been applied to control of a combined heat and power plant. One of the main features of this plant is that it exhibits nonlinear process behavior due to large throughput swings. In this application, the operating window of the plant has been divided into a number of smaller windows in which the nonlinear process behavior has been approximated by linear behavior. For each operating window, linear step weight models were developed from a detailed nonlinear first principles model, and the model prediction is calculated based on interpolation between these linear models. The model output at each operating point can then be calculated from four basic linear models, and the required control action can subsequently be calculated with the standard model predictive control approach using quadratic programming.

  15. Secondary whirls in thermoconvective vortices developed in a cylindrical annulus locally heated from below

    NASA Astrophysics Data System (ADS)

    Castaño, D.; Navarro, M. C.; Herrero, H.

    2015-11-01

    This paper shows numerically the formation of secondary whirls embedded in axisymmetric vertical vortices generated in a cylindrical annulus non-homogeneously heated from below. This secondary circulation, that is formed near the center of the primary vortex, appears after a thermoconvective instability. The transition from the axisymmetric vortex to the time-dependent flow where the subvortex is found is studied using nonlinear simulations. The size of the inner radius of the cylindrical annulus is relevant for the appearance or not of subvortices. They only form for small and medium values of the inner radius. The temperature profile at the bottom affects the intensity of the subvortex generated. Results are remarkable as they qualitatively describe observations in dust devils.

  16. State and local regulation of district-heating-and-cooling systems: issues and options

    SciTech Connect

    Kier, P.; Feit, J.; Hanselman, W.; Loube, R.; Meek, C.; Wilson, W.

    1981-11-01

    Basic questions pertaining to public regulation of district heating and cooling (DHC) systems are investigated. Any such system not completely contained within a single tract of privately owned land, or which makes retail sales of thermal energy, may be subject to the same sort of state regulation that electric and gas utilities receive. Many states apply traditional utility regulation to DHC systems, especially those that are investor-owned. State regulation of an energy utility usually establishes pervasive control over the utility's basic activities: its entry into a market, construction (though usually not siting) of its facilities, its service rates and revenue requirements, the quantity and quality of service it provides, and the conditions under which service may be abandoned. Some states, however, take less traditional approaches to DHC regulation - including nonregulation, less regulation for DHC than for electric and gas companies, and DHC regulation on a case-by-case basis. These approaches are examined to determine how each affects the startup of new DHC systems, the revitalization of old systems, and development of both. The report also addresses a variety of possible ownership arrangements for a DHC system and its main subsystems, as well as a variety of cost-allocation procedures that can be employed by a company cogenerating electrical and thermal energy. Material appended to the report backgrounds DHC operations in several European countries and presents US case law and recent state legislation pertaining to DHC regulation. The authors view district heating as a socially useful technology that can reduce US consumption of scarce and imported fuels, and they argue in general that appropriate DHC regulation is one means of helping the technology become established and expand. They recommend no specific regulatory approach, however; instead, they seek to clarify issues and present options on which decisions about DHC regulation can be based.

  17. Downwind evolution of surface fluxes over a vegetated surface during local advection of heat and saturation deficit

    NASA Astrophysics Data System (ADS)

    Zermeo-Gonzalez, A.; Hipps, L. E.

    1997-05-01

    The horizontal advection of warm, dry air to a vegetated surface and the resulting effects on evaporation were examined. Contrary to the decreasing trend of evaporation with downwind distance predicted by traditional models, the eddy covariance measurements made in this study indicated that evaporation remained nearly constant with downwind distance over the few hundred meters considered. Under stronger advection there was even some evidence of increases in evaporation with distance. Canopy conductance values calculated from the measured values of sensible and latent heat fluxes wind speed and canopy temperature, suggested that canopy conductance increased with downwind distance, likely in response to the reduction in saturation deficit. The stomatal response to increases in humidity may have compensated for the effects of the humidity on transpiration, allowing the evaporation flux to continue at a high rate. These results support similar assertions made by recent studies. The mechanisms of heat and water vapor transfer between the surface and the atmosphere, downwind of the transition were analyzed using spectral analyses. Power spectra of temperature and humidity scalars showed changes with downwind distance that appear to be governed by both the upwind conditions and the growing local boundary layer. Cross-spectra of the vertical fluxes suggested that at lower frequencies the vertical motions preceded changes in temperature and humidity, whereas at higher frequencies the changes in the scalars led the changes in vertical motions. This suggests that large eddies generated over the upwind surface were essentially independent of the stability of the local boundary layer growing over the new surface. These findings suggest possible mechanisms for the recent observations that local similarity is not valid under these conditions. Observations of ramps of humidity and temperature at all downwind locations suggest that coherent structures were common. Intermittency of fluxes was estimated with a simple procedure, and suggested that a substantial portion of the fluxes occurred during intermittent events. More analyses of coherent structures and intermittency are needed to better understand the mechanisms of transport under advection conditions.

  18. Genome-wide analysis of the Populus Hsp90 gene family reveals differential expression patterns, localization, and heat stress responses

    PubMed Central

    2013-01-01

    Background Members of the heat shock protein 90 (Hsp90) class of proteins are evolutionarily conserved molecular chaperones. They are involved in protein folding, assembly, stabilization, activation, and degradation in many normal cellular processes and under stress conditions. Unlike many other well-characterized molecular chaperones, Hsp90s play key roles in signal transduction, cell-cycle control, genomic silencing, and protein trafficking. However, no systematic analysis of genome organization, gene structure, and expression compendium has been performed in the Populus model tree genus to date. Results We performed a comprehensive analysis of the Populus Hsp90 gene family and identified 10 Populus Hsp90 genes, which were phylogenetically clustered into two major groups. Gene structure and motif composition are relatively conserved in each group. In Populus trichocarpa, we identified three paralogous pairs, among which the PtHsp90-5a/PtHsp90-5b paralogous pair might be created by duplication of a genome segment. Subcellular localization analysis shows that PtHsp90 members are localized in different subcellular compartments. PtHsp90-3 is localized both in the nucleus and in the cytoplasm, PtHsp90-5a and PtHsp90-5b are in chloroplasts, and PtHsp90-7 is in the endoplasmic reticulum (ER). Furthermore, microarray and semi-quantitative real-time RT-PCR analyses show that a number of Populus Hsp90 genes are differentially expressed upon exposure to various stresses. Conclusions The gene structure and motif composition of PtHsp90s are highly conserved among group members, suggesting that members of the same group may also have conserved functions. Microarray and RT-PCR analyses show that most PtHsp90s were induced by various stresses, including heat stress. Collectively, these observations lay the foundation for future efforts to unravel the biological roles of PtHsp90 genes. PMID:23915275

  19. Determination of local anesthetics in illegal products using HPLC method with amperometric detection.

    PubMed

    Jadach, Magdalena; Błazewicz, Agata; Fijalek, Zbigniew

    2012-01-01

    An HPLC method with amperometric detection was developed for analysis of two local anesthetics (lidocaine and benzocaine) in products for delaying ejaculation illegally marketed in Polish sex shops. Chromatographic elution on an RP column C18 with mobile phase composed of acetate buffer with acetonitrile, provides an optimal separation not only of active substances but also electroactive preservatives which are occasionally added to cosmetic creams (methylparaben and propylparaben). Application of glassy carbon electrode as a working electrode and a procedure with pulsed potential waveforms enables a sensitive, accurate measurement within a relatively short analysis time (250 s). This method has been successfully employed for the determination of local anesthetics in products under investigation. The obtained results show that most samples contained therapeutic concentrations of lidocaine or benzocaine. According to European law, a sale of products containing lidocaine or benzocaine outside the pharmacy sector is forbidden. PMID:22594253

  20. The increase in the rate of heat production of frog's skeletal muscle caused by hypertonic solutions

    PubMed Central

    Yamada, K.

    1970-01-01

    1. The rate of heat production of resting muscle is increased by hypertonic solutions. 2. The threshold osmolality required to produce the increased heat rate is less than 2 times normal; at 25-3 times normal the heat production rises to 20-50 mcal.g-1.min-1, which is 10-20 times the basal rate. 3. In anaerobic conditions, the effect of hypertonic solutions on heat rate is only one tenth of that in aerobic conditions. 4. A glycerol-treated muscle, with damaged tubular system, still gives a normal response to hypertonic solutions, though it does not respond to raised K+ concentration. 5. The metabolic response to hypertonic solutions is considerably suppressed by procaine. 6. Ouabain, 10-5-10-4 M, has no effect. 7. The response remains substantial in a muscle which has been depolarized in isotonic K2SO4. 8. The membrane potential is slightly reduced by hypertonic solutions, but this cannot account for the increase of the resting metabolism. 9. It is suggested that the effect may be due to the release of calcium ions, which produce an increase in myosin ATPase activity. PMID:4250826

  1. Dissolved gas exsolution to enhance gas production and transport during bench-scale electrical resistance heating

    NASA Astrophysics Data System (ADS)

    Hegele, P. R.; Mumford, K. G.

    2015-05-01

    Condensation of volatile organic compounds in colder zones can be detrimental to the performance of an in situ thermal treatment application for the remediation of chlorinated solvent source zones. A novel method to increase gas production and limit convective heat loss in more permeable, potentially colder, zones involves the injection and liberation of dissolved gas from solution during heating. Bench-scale electrical resistance heating experiments were performed with a dissolved carbon dioxide and sodium chloride solution to investigate exsolved gas saturations and transport regimes at elevated, but sub-boiling, temperatures. At sub-boiling temperatures, maximum exsolved gas saturations of Sg = 0.12 were attained, and could be sustained when the carbon dioxide solution was injected during heating rather than emplaced prior to heating. This gas saturation was estimated to decrease groundwater relative permeability to krw = 0.64. Discontinuous gas transport was observed above saturations of Sg = 0.07, demonstrating the potential of exsolved CO2 to bridge vertical gas transport through colder zones.

  2. Heat production rate from radioactive elements in igneous and metamorphic rocks in Eastern Desert, Egypt.

    PubMed

    Abbady, Adel G E; El-Arabi, A M; Abbady, A

    2006-01-01

    Radioactive heat-production data of Igneous and Metamorphic outcrops in the Eastern Desert are presented. Samples were analysed using a low level gamma-ray spectrometer (HPGe) in the laboratory. A total of 205 rock samples were investigated, covering all major rock types of the area. The heat-production rate of igneous rocks ranges from 0.11 (basalt) to 9.53 microWm(-3) (granite). In metamorphic rocks it varies from 0.28 (serpentinite ) to 0.91 microWm(-3) (metagabbro). The contribution due to U is about 51%, as that from Th is 31% and 18% from K. The corresponding values in igneous rocks are 76%, 19% and 5%, respectively. The calculated values showed good agreement with global values except in some areas containing granites. PMID:16120480

  3. High frequency core localized modes in neutral beam heated plasmas on TFTR

    SciTech Connect

    Nazikian, R.; Chang, Z.; Fredrickson, E.D.

    1995-11-01

    A band of high frequency modes in the range 50--150 kHz with intermediate toroidal mode numbers 4 < n < 10 are commonly observed in the core of supershot plasmas on TFTR. Two distinct varieties of MHD modes are identified corresponding to a flute-like mode predominantly appearing around the q = 1 surface and an outward ballooning mode for q > 1. The flute-like modes have nearly equal amplitude on the high field and low field side of the magnetic axis and are mostly observed in moderate performance supershot plasmas with {tau}{sub E} < 2{tau}{sub L} while the ballooning-like modes have enhanced amplitude on the low field side of the magnetic axis and tend to appear in higher performance supershot plasmas with {tau}{sub E} > 2{tau}{sub L}, where {tau}{sub L} is the equivalent L-mode confinement time. The modes propagate in the ion diamagnetic drift direction and are highly localized with radial widths {Delta}r {approximately} 5--10 cm, fluctuation levels {tilde n}/n, {tilde T}{sub e}/T{sub e} < 0.01, and radial displacements {zeta}{sub r} {approximately} 0.1 cm. Unlike the toroidally localized high-n activity observed just prior to major and minor disruptions on TFTR, these modes are typically much weaker, more benign, and may be indicative of kinetic ballooning modes destabilized by resonant circulating neutral beam ions.

  4. Increasing the heat resistance of products made from vitreous silica for semiconductors

    SciTech Connect

    Zhuravlev, G.I.; Leiv, V.G.; Serkova, N.G.; Khotimchenko, V.S.

    1986-09-01

    Experiments are described in finding optimum heat-protective coatings for silica used in high-temperature process equipment for the production of semiconductor materials. The protective coatings tested were applied by plasma arc spraying and consisted of oxides of hafnium, zirconium, aluminium, and titanium, along with a zirconium phosphate. Data are given on their relative viscosities, thermal expansion behaviors, and melting points, as well as their proneness to high-temperature deformation.

  5. Acquisition of thermotolerance in soybean seedlings: synthesis and accumulation of heat shock proteins and their cellular localization

    SciTech Connect

    Lin, C.Y.; Roberts, J.K.; Key, J.L.

    1984-01-01

    When soybean Glycine max var Wayne seedlings are shifted from a normal growth temperature of 28/sup 0/C up to 40/sup 0/C (heat shock or HS), there is a dramatic change in protein synthesis. A new set of proteins known as shock proteins (HSPs) is produced and normal protein synthesis is greatly reduced. However, a pretreatmemt at 40/sup 0/C or a brief (10 minute) pulse treatment at 45/sup 0/C followed by a 28/sup 0/C incubation provide protection (thermal tolerance) to a subsequent exposure at 45/sup 0/C. During 40/sup 0/C HS, some HSPs become localized and stably associated with purified organelle fractions while others do not. A chase at 28/sup 0/C results in the gradual loss over a 4-hour period of the HSPs from the organelle fractions, but the HSPs remain selectively localized during a 40/sup 0/C chase period. The relative amount of HSPs which relocalize during a second HS increases with higher temperatures from 40/sup 0/C to 45/sup 0/C. Proteins induced by arsenite treatment are not selectively localized with organelle fractions at 28/sup 0/C but become organelle-associated during a subsequent HS at 40/sup 0/C.

  6. Endocytosis of Mycobacterium tuberculosis Heat Shock Protein 60 Is Required to Induce Interleukin-10 Production in Macrophages*

    PubMed Central

    Parveen, Nazia; Varman, Raja; Nair, Shiny; Das, Gobardhan; Ghosh, Sudip; Mukhopadhyay, Sangita

    2013-01-01

    Understanding the signaling pathways involved in the regulation of anti-inflammatory and pro-inflammatory responses in tuberculosis is extremely important in tailoring a macrophage innate response to promote anti-tuberculosis immunity in the host. Although the role of toll-like receptors (TLRs) in the regulation of anti-inflammatory and pro-inflammatory responses is known, the detailed molecular mechanisms by which the Mycobacterium tuberculosis bacteria modulate these innate responses are not clearly understood. In this study, we demonstrate that M. tuberculosis heat shock protein 60 (Mtbhsp60, Cpn60.1, and Rv3417c) interacts with both TLR2 and TLR4 receptors, but its interaction with TLR2 leads to clathrin-dependent endocytosis resulting in an increased production of interleukin (IL)-10 and activated p38 MAPK. Blockage of TLR2-mediated endocytosis inhibited IL-10 production but induced production of tumor necrosis factor (TNF)-? and activated ERK1/2. In contrast, upon interaction with TLR4, Mtbhsp60 remained predominantly localized on the cell surface due to poorer endocytosis of the protein that led to decreased IL-10 production and p38 MAPK activation. The Escherichia coli homologue of hsp60 was found to be retained mainly on the macrophage surface upon interaction with either TLR2 or TLR4 that triggered predominantly a pro-inflammatory-type immune response. Our data suggest that cellular localization of Mtbhsp60 upon interaction with TLRs dictates the type of polarization in the innate immune responses in macrophages. This information is likely to help us in tailoring the host protective immune responses against M. tuberculosis. PMID:23846686

  7. Extreme heat reduces and shifts United States premium wine production in the 21st century

    PubMed Central

    White, M. A.; Diffenbaugh, N. S.; Jones, G. V.; Pal, J. S.; Giorgi, F.

    2006-01-01

    Premium wine production is limited to regions climatically conducive to growing grapes with balanced composition and varietal typicity. Three central climatic conditions are required: (i) adequate heat accumulation; (ii) low risk of severe frost damage; and (iii) the absence of extreme heat. Although wine production is possible in an extensive climatic range, the highest-quality wines require a delicate balance among these three conditions. Although historical and projected average temperature changes are known to influence global wine quality, the potential future response of wine-producing regions to spatially heterogeneous changes in extreme events is largely unknown. Here, by using a high-resolution regional climate model forced by the Intergovernmental Panel on Climate Change Special Report on Emission Scenarios A2 greenhouse gas emission scenario, we estimate that potential premium winegrape production area in the conterminous United States could decline by up to 81% by the late 21st century. While increases in heat accumulation will shift wine production to warmer climate varieties and/or lower-quality wines, and frost constraints will be reduced, increases in the frequency of extreme hot days (>35C) in the growing season are projected to eliminate winegrape production in many areas of the United States. Furthermore, grape and wine production will likely be restricted to a narrow West Coast region and the Northwest and Northeast, areas currently facing challenges related to excess moisture. Our results not only imply large changes for the premium wine industry, but also highlight the importance of incorporating fine-scale processes and extreme events in climate-change impact studies. PMID:16840557

  8. Local heat-transfer measurements on a large, scale-model turbine blade airfoil using a composite of a heater element and liquid crystals

    NASA Technical Reports Server (NTRS)

    Hippensteele, S. A.; Russell, L. M.; Torres, F. J.

    1985-01-01

    Local heat transfer coefficients were experimentally mapped along the midchord of a five-time-size turbine blade airfoil in a static cascade operated at room temperature over a range of Reynolds numbers. The test surface consisted of a composite of commercially available materials: a mylar sheet with a layer of cholesteric liquid crystals, that change color with temperature, and a heater sheet made of a carbon-impregnated paper, that produces uniform heat flux. After the initial selection and calibration of the composite sheet, accurate, quantitative, and continuous heat transfer coefficients were mapped over the airfoil surface. The local heat transfer coefficients are presented for Reynolds numbers from 2.8 x 10 to the 5th power to 7.6 x 10 to the 5th power. Comparisons are made with analytical values of heat transfer coefficients obtained from the STAN5 boundary layer code. Also, a leading edge separation bubble was revealed by thermal and flow visualization.

  9. Production of pyrolytic liquids from industrial sewage sludges in an induction-heating reactor.

    PubMed

    Tsai, Wen-Tien; Chang, Jeng-Hung; Hsien, Kuo-Jung; Chang, Yuan-Ming

    2009-01-01

    With the application of induction-heating, the pyrolytic experiments have been carried out for three sewage sludges from the food processing factories in an externally heated fixed-bed reactor. The thermochemical characteristics of sludge samples were first analyzed. The results indicated that the calorific value had about 15 MJ/kg on an average, suggesting that it had a potential for biomass energy source. However, its nitrogen concentration was relatively high. From the thermogravimetric analysis (TGA) curves, it showed that the pyrolysis reaction can be almost finished in the temperature range of 450-750 degrees C. The yields of resulting liquid and char products from the pyrolysis of sewage sludge were discussed for examining the effects of pyrolysis temperature (500-800 degrees C), heating rate (200-500 degrees C/min), and holding time (1-8 min). Overall, the variation of yield was not so significant in the experimental conditions for three sewage sludges. All results of the resulting liquid products analyzed by elemental analyzer, pH meter, Karl-Fischer moisture titrator and bomb calorimeter were in consistence with those analyses by FTIR spectroscopy. Furthermore, the pyrolysis liquid products contained large amounts of water (>73% by weight) mostly derived from the bound water in the biosludge feedstocks and the condensation reactions during the pyrolysis reaction, and fewer contents of oxygenated hydrocarbons composing of carbonyl and nitrogen-containing groups, resulting in low pH and low calorific values. PMID:18656347

  10. Technological Alternatives or Use of Wood Fuel in Combined Heat and Power Production

    NASA Astrophysics Data System (ADS)

    Rusanova, Jekaterina; Markova, Darja; Bazbauers, Gatis; Valters, Kārlis

    2013-12-01

    Abstract Latvia aims for 40% share of renewable energy in the total final energy use. Latvia has large resources of biomass and developed district heating systems. Therefore, use of biomass for heat and power production is an economically attractive path for increase of the share of renewable energy. The optimum technological solution for use of biomass and required fuel resources have to be identified for energy planning and policy purposes. The aim of this study was to compare several wood fuel based energy conversion technologies from the technical and economical point of view. Three biomass conversion technologies for combined heat and electricity production (CHP) were analyzed: • CHP with steam turbine technology; • gasification CHP using gas engine; • bio-methane combined cycle CHP. Electricity prices for each alternative are presented. The results show the level of support needed for the analyzed renewable energy technologies and time period needed to reach price parity with the natural gas - fired combined cycle gas turbine (CCGT) CHPss. The results also show that bio-methane technology is most competitive when compared with CCGT among the considered technologies regarding fuel consumption and electricity production, but it is necessary to reduce investment costs to reach the electricity price parity with the natural gas CCGT.

  11. The impact of local geochemical variability on quantifying hillslope soil production and chemical weathering

    NASA Astrophysics Data System (ADS)

    Heimsath, Arjun M.; Burke, Benjamin C.

    2013-10-01

    Soil-mantled upland landscapes are widespread across the habitable world, support extensive life, and are the interface between the atmosphere, hydrosphere, and lithosphere but typically are not cultivated. Soil found across such landscapes fits the conceptual framework of a physically mobile layer derived from the underlying parent material along with some locally derived organic content. The extent and persistence of these upland soils depend on the long-term balance between soil production and erosion. Here we briefly review methods used to quantify the physical and chemical processes of soil production and erosion and revisit three granitic study areas in southeastern Australia and northern California that enabled early quantification of the soil production function and topographic controls on chemical weathering. We then present new major and trace element data from 2-m by 2-m pits dug at each field site to quantify local variability of Zr concentrations and the chemical index of alteration (CIA), weathering indices used to determine chemical weathering rates and extents in soils and saprolites. Using both new and previously published data, we compare differences between local variability and regional, as well as intersite variability of these important indices. For each of the 2-m pits, we collected 25 samples and found that the simple mean and the 2σ standard deviation best describe the local variation in the data. We also find that the variability in the 2-m pit data lies within variability observed in the same data from samples collected in individual soil pits across each of the field sites and that the differences between sites are consistent with previously published results. These observations highlight the importance of quantifying local scale variability in studies that use similar, multifaceted measurements to quantify hillslope soil production and erosion processes.

  12. Studies of the use of high-temperature nuclear heat from an HTGR for hydrogen production

    NASA Technical Reports Server (NTRS)

    Peterman, D. D.; Fontaine, R. W.; Quade, R. N.; Halvers, L. J.; Jahromi, A. M.

    1975-01-01

    The results of a study which surveyed various methods of hydrogen production using nuclear and fossil energy are presented. A description of these methods is provided, and efficiencies are calculated for each case. The process designs of systems that utilize the heat from a general atomic high temperature gas cooled reactor with a steam methane reformer and feed the reformer with substitute natural gas manufactured from coal, using reforming temperatures, are presented. The capital costs for these systems and the resultant hydrogen production price for these cases are discussed along with a research and development program.

  13. Processing Method for Enlarging Partial Diameter of Steel Shaft Heated Locally by High Frequency Induction

    NASA Astrophysics Data System (ADS)

    Mori, Kazuki; Suzuki, Risa; Okabe, Nagatoshi; Zhu, Xia; Iura, Tadashi

    In the present works effective application of partial preheating by high frequency induction to enlarge the partial diameter of middle carbon steel was experimentally investigated. The partial reheating was carried out by varying preheating times under the same electric power conditions. As all other conditions other than temperature remained constant during the diameter enlargement experiments, the partial preheating effects were clarified to be estimative using a parameter of the ?/?y, which was found to be dependent on temperature regardless of constant compressive axial stress. For heating times of less than 50 sec, the preheating effect for promoting partial diameter-enlargement did not appear. In fact the reverse effect appeared in times ranging from 30 sec to 50 sec due to blue brittleness generated at temperatures from about 523K to about 623K. Also, low cycle fatigue cracks must be avoided when initiating at the filet end of an enlarged shaft while passing through the temperature range of blue brittleness during the cooling process. Therefore, the preheating temperature found to be most effective for promoting the diameter enlargement was greater than about 856K so as to increase easily the Df/D0 to above 2 times without generating damage cracks from fatigue.

  14. Evidence of locally enhanced target heating due to instabilities of counter-streaming fast electron beams

    SciTech Connect

    Koester, Petra; Cecchetti, Carlo A.; Booth, Nicola; Woolsey, Nigel; Chen, Hui; Evans, Roger G.; Gregori, Gianluca; Li, Bin; Mithen, James; Murphy, Christopher D.; Labate, Luca; Gizzi, Leonida A.; Levato, Tadzio; Makita, Mikako; Riley, David; Notley, Margaret; Pattathil, Rajeev

    2015-02-15

    The high-current fast electron beams generated in high-intensity laser-solid interactions require the onset of a balancing return current in order to propagate in the target material. Such a system of counter-streaming electron currents is unstable to a variety of instabilities such as the current-filamentation instability and the two-stream instability. An experimental study aimed at investigating the role of instabilities in a system of symmetrical counter-propagating fast electron beams is presented here for the first time. The fast electron beams are generated by double-sided laser-irradiation of a layered target foil at laser intensities above 10{sup 19 }W/cm{sup 2}. High-resolution X-ray spectroscopy of the emission from the central Ti layer shows that locally enhanced energy deposition is indeed achieved in the case of counter-propagating fast electron beams.

  15. Differences and implications in biogeochemistry from maximizing entropy production locally versus globally

    NASA Astrophysics Data System (ADS)

    Vallino, J. J.

    2011-01-01

    In this manuscript we investigate the use of the maximum entropy production (MEP) principle for modeling biogeochemical processes that are catalyzed by living systems. Because of novelties introduced by the MEP approach, many questions need to be answered and techniques developed in the application of MEP to describe biological systems that are responsible for energy and mass transformations on a planetary scale. In previous work we introduce the importance of integrating entropy production over time to distinguish abiotic from biotic processes under transient conditions. Here we investigate the ramifications of modeling biological systems involving one or more spatial dimensions. When modeling systems with spatial dimensions, entropy production can be maximized either locally at each point in space asynchronously or globally over the system domain synchronously. We use a simple two-box model inspired by two-layer ocean models to illustrate the differences in local versus global entropy maximization. Synthesis and oxidation of biological structure is modeled using two autocatalytic reactions that account for changes in community kinetics using a single parameter each. Our results show that entropy production can be increased if maximized over the system domain rather than locally, which has important implications regarding how biological systems organize and supports the hypothesis for multiple levels of selection and cooperation in biology for the dissipation of free energy.

  16. Differences and implications in biogeochemistry from maximizing entropy production locally versus globally

    NASA Astrophysics Data System (ADS)

    Vallino, J. J.

    2011-06-01

    In this manuscript we investigate the use of the maximum entropy production (MEP) principle for modeling biogeochemical processes that are catalyzed by living systems. Because of novelties introduced by the MEP approach, many questions need to be answered and techniques developed in the application of MEP to describe biological systems that are responsible for energy and mass transformations on a planetary scale. In previous work we introduce the importance of integrating entropy production over time to distinguish abiotic from biotic processes under transient conditions. Here we investigate the ramifications of modeling biological systems involving one or more spatial dimensions. When modeling systems over space, entropy production can be maximized either locally at each point in space asynchronously or globally over the system domain synchronously. We use a simple two-box model inspired by two-layer ocean models to illustrate the differences in local versus global entropy maximization. Synthesis and oxidation of biological structure is modeled using two autocatalytic reactions that account for changes in community kinetics using a single parameter each. Our results show that entropy production can be increased if maximized over the system domain rather than locally, which has important implications regarding how biological systems organize and supports the hypothesis for multiple levels of selection and cooperation in biology for the dissipation of free energy.

  17. The importance of localized auxin production for morphogenesis of reproductive organs and embryos in Arabidopsis.

    PubMed

    Robert, Hlne S; Crhak Khaitova, Lucie; Mroue, Souad; Benkov, Eva

    2015-08-01

    Plant sexual reproduction involves highly structured and specialized organs: stamens (male) and gynoecia (female, containing ovules). These organs synchronously develop within protective flower buds, until anthesis, via tightly coordinated mechanisms that are essential for effective fertilization and production of viable seeds. The phytohormone auxin is one of the key endogenous signalling molecules controlling initiation and development of these, and other, plant organs. In particular, its uneven distribution, resulting from tightly controlled production, metabolism and directional transport, is an important morphogenic factor. In this review we discuss how developmentally controlled and localized auxin biosynthesis and transport contribute to the coordinated development of plants' reproductive organs, and their fertilized derivatives (embryos) via the regulation of auxin levels and distribution within and around them. Current understanding of the links between de novo local auxin biosynthesis, auxin transport and/or signalling is presented to highlight the importance of the non-cell autonomous action of auxin production on development and morphogenesis of reproductive organs and embryos. An overview of transcription factor families, which spatiotemporally define local auxin production by controlling key auxin biosynthetic enzymes, is also presented. PMID:26019252

  18. MODIS LAI and FPAR Product on Global, Regional and Local Scales

    NASA Astrophysics Data System (ADS)

    Knyazikhin, Y.; Yang, W.; Dong, H.; Bin, T.; Shabanov, N.; Myneni, R.

    2003-12-01

    An algorithm based on physics of radiative transfer in vegetation canopies for the retrieval of vegetation green leaf area index (LAI) and fraction of absorbed photosynthetically active radiation (FPAR) from MODIS surface reflectance data was developed, prototyped and is in operational production at NASA computing facilities since June 2000. This presentation is focused on the analysis of the of the LAI and FPAR retrievals as a function of time and spatial scale as detailed below. First theme covers analysis of the global MODIS LAI and FPAR products from July 2000 to December 2002, collections 1 and 3. About 70% of the total retrievals are obtained with the main radiative transfer based algorithm. Temporal compositing from 8-day to monthly further increases the frequency of main algorithm retrievals. The retrieved LAI and FPAR fields display expected features when analyzed by biomes and latitudes. The main algorithm fails as expected when input surface reflectance data have high uncertainties, especially under snow and cloud conditions. The analysis presented here reinforces the need for examining product quality flags accompanying the LAI and FPAR product before using these products in application studies. Second theme covers analysis of the LAI product at regional and local scales. We highlight the statistical nature of MODIS LAI and FPAR products arising from the relation between uncertainties in algorithm inputs and outputs, using Collection 3 MODIS LAI product. Two random variables impact the quality of retrieved LAI and FPAR fields at local scale- uncertainties in biome classification and surface reflectance measurements. To decrease impact of input uncertainties, averaging of LAI and FPAR product over an extended area is required to accumulate a sufficient number of pixels with high quality input. Further improvements in LAI and FPAR retrieval coverage and quality will require a better consistency between observed and simulated reflectances in spectral space.

  19. Human hnRNP Q re-localizes to cytoplasmic granules upon PMA, thapsigargin, arsenite and heat-shock treatments

    SciTech Connect

    Quaresma, Alexandre J.C.; Bressan, G.C.; Gava, L.M.; Lanza, D.C.F.; Ramos, C.H.I; Kobarg, Joerg

    2009-04-01

    Eukaryotic gene expression is regulated on different levels ranging from pre-mRNA processing to translation. One of the most characterized families of RNA-binding proteins is the group of hnRNPs: heterogenous nuclear ribonucleoproteins. Members of this protein family play important roles in gene expression control and mRNAs metabolism. In the cytoplasm, several hnRNPs proteins are involved in RNA-related processes and they can be frequently found in two specialized structures, known as GW-bodies (GWbs), previously known as processing bodies: PBs, and stress granules, which may be formed in response to specific stimuli. GWbs have been early reported to be involved in the mRNA decay process, acting as a site of mRNA degradation. In a similar way, stress granules (SGs) have been described as cytoplasmic aggregates, which contain accumulated mRNAs in cells under stress conditions and present reduced or inhibited translation. Here, we characterized the hnRNP Q localization after different stress conditions. hnRNP Q is a predominantly nuclear protein that exhibits a modular organization and several RNA-related functions. Our data suggest that the nuclear localization of hnRNP Q might be modified after different treatments, such as: PMA, thapsigargin, arsenite and heat shock. Under different stress conditions, hnRNP Q can fully co-localize with the endoplasmatic reticulum specific chaperone, BiP. However, under stress, this protein only co-localizes partially with the proteins: GW182 - GWbs marker protein and TIA-1 stress granule component.

  20. Human hnRNP Q re-localizes to cytoplasmic granules upon PMA, thapsigargin, arsenite and heat-shock treatments.

    PubMed

    Quaresma, Alexandre J C; Bressan, G C; Gava, L M; Lanza, D C F; Ramos, C H I; Kobarg, Jrg

    2009-04-01

    Eukaryotic gene expression is regulated on different levels ranging from pre-mRNA processing to translation. One of the most characterized families of RNA-binding proteins is the group of hnRNPs: heterogenous nuclear ribonucleoproteins. Members of this protein family play important roles in gene expression control and mRNAs metabolism. In the cytoplasm, several hnRNPs proteins are involved in RNA-related processes and they can be frequently found in two specialized structures, known as GW-bodies (GWbs), previously known as processing bodies: PBs, and stress granules, which may be formed in response to specific stimuli. GWbs have been early reported to be involved in the mRNA decay process, acting as a site of mRNA degradation. In a similar way, stress granules (SGs) have been described as cytoplasmic aggregates, which contain accumulated mRNAs in cells under stress conditions and present reduced or inhibited translation. Here, we characterized the hnRNP Q localization after different stress conditions. hnRNP Q is a predominantly nuclear protein that exhibits a modular organization and several RNA-related functions. Our data suggest that the nuclear localization of hnRNP Q might be modified after different treatments, such as: PMA, thapsigargin, arsenite and heat shock. Under different stress conditions, hnRNP Q can fully co-localize with the endoplasmatic reticulum specific chaperone, BiP. However, under stress, this protein only co-localizes partially with the proteins: GW182-GWbs marker protein and TIA-1 stress granule component. PMID:19331829

  1. Production of tritium, neutrons, and heat based on the transmission resonance model (TRM) for cold fusion

    NASA Astrophysics Data System (ADS)

    Bush, Robert T.

    1991-05-01

    The TRM has recently been successful in fitting calorimetric data having interesting nonlinear structure. The model appears to provide a natural description for electrolytic cold fusion in terms of ``fractals''. Extended to the time dimension, the model can apparently account for the phenomenon of heat ``bursts''. The TRM combines a transmission condition involving quantized energies and an engergy shift of a Maxwell-Boltzmann energy distribution of deuterons at the cathodic surface that appears related to the concentration overpotential (hydrogen overvoltage). The model suggest three possible regimes vis-a-vis tritium production in terms of this energy shift, and indicates why measurable tritium production in the electrolytic case will tend to be the exception rather than the rule in absence of a recipe: Below a shift of approximately 2.8 meV there is production of both tritium and measureable excess heat, with the possibility of accounting for the Bockris curve indicating about a 1% correlation between excess heat and tritium. However, over the large range from about 2.8 meV to 340 meV energy shift there is a regime of observable excess heat production but little, and probably no measurable, tritium production. The third regime is more hypothetical: It begins at an energy shift of about 1 keV and extends to the boundaries of ``hot'' fusion at about 10 keV. A new type of nucelar reaction, trint (for transmission resonance-induced neutron transfer), is suggested by the model leading to triton and neutron production. A charge distribution ``polarization conjecture'' is the basis for theoretical derivation for the low-energy limit for an energy-dependent branching ratio for D-on-D. When the values of the parameters are inserted, this expression yields an estimate for the ratio of neutron-to-triton production of about 1.6410-9. The possibility of some three-body reactions is also suggested. A comparison of the TRM's transmission energy levels for palladium deuteride and titanium deuteride is interesting when compared to recent data on neutron emission by Zelenskii. Theoretical work relating the TRM to stoichiometric considerations appear to enhance the significance of this hypothetical model.

  2. Arabidopsis HEAT SHOCK TRANSCRIPTION FACTORA1b overexpression enhances water productivity, resistance to drought, and infection.

    PubMed

    Bechtold, Ulrike; Albihlal, Waleed S; Lawson, Tracy; Fryer, Michael J; Sparrow, Penelope A C; Richard, François; Persad, Ramona; Bowden, Laura; Hickman, Richard; Martin, Cathie; Beynon, Jim L; Buchanan-Wollaston, Vicky; Baker, Neil R; Morison, James I L; Schöffl, Friedrich; Ott, Sascha; Mullineaux, Philip M

    2013-08-01

    Heat-stressed crops suffer dehydration, depressed growth, and a consequent decline in water productivity, which is the yield of harvestable product as a function of lifetime water consumption and is a trait associated with plant growth and development. Heat shock transcription factor (HSF) genes have been implicated not only in thermotolerance but also in plant growth and development, and therefore could influence water productivity. Here it is demonstrated that Arabidopsis thaliana plants with increased HSFA1b expression showed increased water productivity and harvest index under water-replete and water-limiting conditions. In non-stressed HSFA1b-overexpressing (HSFA1bOx) plants, 509 genes showed altered expression, and these genes were not over-represented for development-associated genes but were for response to biotic stress. This confirmed an additional role for HSFA1b in maintaining basal disease resistance, which was stress hormone independent but involved H₂O₂ signalling. Fifty-five of the 509 genes harbour a variant of the heat shock element (HSE) in their promoters, here named HSE1b. Chromatin immunoprecipitation-PCR confirmed binding of HSFA1b to HSE1b in vivo, including in seven transcription factor genes. One of these is MULTIPROTEIN BRIDGING FACTOR1c (MBF1c). Plants overexpressing MBF1c showed enhanced basal resistance but not water productivity, thus partially phenocopying HSFA1bOx plants. A comparison of genes responsive to HSFA1b and MBF1c overexpression revealed a common group, none of which harbours a HSE1b motif. From this example, it is suggested that HSFA1b directly regulates 55 HSE1b-containing genes, which control the remaining 454 genes, collectively accounting for the stress defence and developmental phenotypes of HSFA1bOx. PMID:23828547

  3. The mechanical properties and heat production of chicken latissimus dorsi muscles during tetanic contractions

    PubMed Central

    Canfield, S. P.

    1971-01-01

    1. A study has been made of the mechanical properties and heat production of chicken anterior (ALD) and posterior (PLD) latissimus dorsi muscles during contractions at 20 C. 2. There is a difference between these two muscles in the time course of the isometric response. The PLD reaches maximum tetanic tension 10 times faster and relaxes 8 times faster than ALD. The ratio of heat rate to isometric tension (heat rate/tension length) for PLD is 7-8 times larger than for ALD. 3. ALD maintains substantial isometric tension for more than 2 min of stimulation. In PLD tetanic tension begins to fall after only 1 sec. 4. The ALD muscle does not show the `activation' heat seen at the start of contraction with frog and toad muscle but this may be present in PLD. 5. There is a range of stimulation frequencies for both muscles over which the fused tetanic tension increases with stimulation frequency. 6. The tensionlength curve of ALD has a pronounced plateau and is broader than that of PLD. 7. The normalized forcevelocity relations for the two muscles are similar and may be fitted by Hill's equation with a value of a/P0 = 015-016. The maximum velocity of unloaded shortening of PLD is 4-5 times that of ALD. 8. Preliminary experiments indicate that the resting heat rate of both muscles is 4 times greater than that of frog muscle at the same temperature. The recovery heat rate of ALD is similar to that of frog. PMID:5158384

  4. High-frequency core localized modes in neutral beam heated plasmas on TFTR

    SciTech Connect

    Nazikian, R.; Chang, Z.; Fredrickson, E.D.; Mazzucato, E.; Batha, S.H.; Bell, R.; Budny, R.; Bush, C.E.; Cheng, C.Z.; Janos, A.; Levinton, F.; Manickam, J.; Mansfield, D.K.; Park, H.K.; Rewoldt, G.; Sabbagh, S.; Synakowski, E.J.; Tang, W.; Taylor, G.; Zakharov, L.E.

    1996-02-01

    A band of high-frequency modes in the range 50{endash}150 kHz with intermediate toroidal mode numbers 4{lt}{ital n}{lt}10 are commonly observed in the core of supershot plasmas on TFTR [R. Hawryluk, Plasma Phys. Controlled Fusion {bold 33}, 1509 (1991)]. Two distinct varieties of magnetohydrodynamic (MHD) modes are identified, corresponding to a flute-like mode predominantly appearing around the {ital q}=1 surface and an outward ballooning mode for {ital q}{approx_gt}1. The flute-like modes have nearly equal amplitude on the high-field and low-field side of the magnetic axis, and are mostly observed in moderate performance supershot plasmas with {tau}{sub {ital E}}{lt}2{tau}{sub L}, while the ballooning-like modes have enhanced amplitude on the low-field side of the magnetic axis and tend to appear in higher performance supershot plasmas with {tau}{sub {ital E}}{approx_gt}2{tau}{sub L}, where {tau}{sub L} is the equivalent L-mode confinement time. Both modes appear to propagate in the ion diamagnetic drift direction and are highly localized with radial widths {Delta}{ital r}{approximately}5{endash}10 cm, fluctuation levels {tilde {ital n}}/{ital n}, {tilde {ital T}}{sub {ital e}}/{ital T}{sub {ital e}}{lt}0.01, and radial displacements {xi}{sub {ital r}}{approximately}0.1 cm. Unlike the toroidally localized high-{ital n} activity observed just prior to major and minor disruptions on TFTR [E. D. Fredrickson {ital et} {ital al}., {ital Proceedings} {ital of} {ital the} 15{ital th} {ital International} {ital Conference} {ital on} {ital Plasma} {ital Physics} {ital and} {ital Controlled} {ital Nuclear} {ital Fusion} {ital Research}, Seville, Spain (International Atomic Energy Agency, Vienna, 1995), No. IAEA-CN-60/A-2-II-5], these modes are typically more benign and may be indicative of MHD activity excited by resonant circulating beam ions. {copyright} {ital 1996 American Institute of Physics.}

  5. Finite Volume schemes on unstructured grids for non-local models: Application to the simulation of heat transport in plasmas

    SciTech Connect

    Goudon, Thierry; Labo. J.A. Dieudonne CNRS and Univ. Nice-Sophia Antipolis , Parc Valrose, 06108 Nice cedex 02 ; Parisot, Martin

    2012-10-15

    In the so-called Spitzer-Haerm regime, equations of plasma physics reduce to a nonlinear parabolic equation for the electronic temperature. Coming back to the derivation of this limiting equation through hydrodynamic regime arguments, one is led to construct a hierarchy of models where the heat fluxes are defined through a non-local relation which can be reinterpreted as well by introducing coupled diffusion equations. We address the question of designing numerical methods to simulate these equations. The basic requirement for the scheme is to be asymptotically consistent with the Spitzer-Haerm regime. Furthermore, the constraints of physically realistic simulations make the use of unstructured meshes unavoidable. We develop a Finite Volume scheme, based on Vertex-Based discretization, which reaches these objectives. We discuss on numerical grounds the efficiency of the method, and the ability of the generalized models in capturing relevant phenomena missed by the asymptotic problem.

  6. Nonadiabatic effects on surfaces: Kohn anomaly, electronic damping of adsorbate vibrations, and local heating of single molecules

    NASA Astrophysics Data System (ADS)

    Krger, J.

    2008-06-01

    Three aspects of electron-phonon coupling at metal surfaces are reviewed. One aspect is the Kohn effect, which describes an anomalous dispersion relation of surface phonons due to quasi-one-dimensional nesting of Fermi surface contours. The combination of electron energy loss spectroscopy and angle-resolved photoelectron spectroscopy allows us to unambiguously characterize Kohn anomaly systems. A second aspect is the nonadiabatic damping of adsorbate vibrations. Characteristic spectroscopic line shapes of vibrational modes allow us to estimate the amount of energy transfer between the vibrational mode and electron-hole pairs. Case studies of a Kohn anomaly and nonadiabatic damping are provided by the hydrogen- and deuterium-covered Mo(110) surface. As a third aspect of interaction between electrons and phonons, local heating of a C60 molecule adsorbed on Cu(100) and in contact with the tip of a scanning tunnelling microscope is covered.

  7. A gyrokinetic one-dimensional scrape-off layer model of an edge-localized mode heat pulse

    SciTech Connect

    Shi, E. L.; Hakim, A. H.; Hammett, G. W.

    2015-02-15

    An electrostatic gyrokinetic-based model is applied to simulate parallel plasma transport in the scrape-off layer to a divertor plate. The authors focus on a test problem that has been studied previously, using parameters chosen to model a heat pulse driven by an edge-localized mode in JET. Previous work has used direct particle-in-cell equations with full dynamics, or Vlasov or fluid equations with only parallel dynamics. With the use of the gyrokinetic quasineutrality equation and logical sheath boundary conditions, spatial and temporal resolution requirements are no longer set by the electron Debye length and plasma frequency, respectively. This test problem also helps illustrate some of the physics contained in the Hamiltonian form of the gyrokinetic equations and some of the numerical challenges in developing an edge gyrokinetic code.

  8. 3D slicing of radiogenic heat production in Bahariya Formation, Tut oil field, North-Western Desert, Egypt.

    PubMed

    Al-Alfy, I M; Nabih, M A

    2013-03-01

    A 3D block of radiogenic heat production was constructed from the subsurface total gamma ray logs of Bahariya Formation, Western Desert, Egypt. The studied rocks possess a range of radiogenic heat production varying from 0.21 μWm(-3) to 2.2 μWm(-3). Sandstone rocks of Bahariya Formation have higher radiogenic heat production than the average for crustal sedimentary rocks. The high values of density log of Bahariya Formation indicate the presence of iron oxides which contribute the uranium radioactive ores that increase the radiogenic heat production of these rocks. The average radiogenic heat production produced from the study area is calculated as 6.3 kW. The histogram and cumulative frequency analyses illustrate that the range from 0.8 to 1.2 μWm(-3) is about 45.3% of radiogenic heat production values. The 3D slicing of the reservoir shows that the southeastern and northeastern parts of the study area have higher radiogenic heat production than other parts. PMID:23291561

  9. A Randomized Controlled Trial of Local Heat Therapy Versus Intravenous Sodium Stibogluconate for the Treatment of Cutaneous Leishmania major Infection

    PubMed Central

    Aronson, Naomi E.; Wortmann, Glenn W.; Byrne, William R.; Howard, Robin S.; Bernstein, Wendy B.; Marovich, Mary A.; Polhemus, Mark E.; Yoon, In-Kyu; Hummer, Kelly A.; Gasser, Robert A.; Oster, Charles N.; Benson, Paul M.

    2010-01-01

    Background Cutaneous Leishmania major has affected many travelers including military personnel in Iraq and Afghanistan. Optimal treatment for this localized infection has not been defined, but interestingly the parasite is thermosensitive. Methodology/Principal Findings Participants with parasitologically confirmed L. major infection were randomized to receive intravenous sodium stibogluconate (SSG) 20mg/kg/day for ten doses or localized ThermoMed (TM) device heat treatment (applied at 50°C for 30 seconds) in one session. Those with facial lesions, infection with other species of Leishmania, or more than 20 lesions were excluded. Primary outcome was complete re-epithelialization or visual healing at two months without relapse over 12 months. Fifty-four/56 enrolled participants received intervention, 27 SSG and 27 TM. In an intent to treat analysis the per subject efficacy at two months with 12 months follow-up was 54% SSG and 48% TM (p = 0.78), and the per lesion efficacy was 59% SSG and 73% TM (p = 0.053). Reversible abdominal pain/pancreatitis, arthralgias, myalgias, headache, fatigue, mild cytopenias, and elevated transaminases were more commonly present in the SSG treated participants, whereas blistering, oozing, and erythema were more common in the TM arm. Conclusions/Significance Skin lesions due to L. major treated with heat delivered by the ThermoMed device healed at a similar rate and with less associated systemic toxicity than lesions treated with intravenous SSG. Clinical Trial Registration ClinicalTrials.gov NCT 00884377 PMID:20231896

  10. Effects of solar radiation and wind speed on metabolic heat production by two mammals with contrasting coat colours.

    PubMed

    Walsberg, G E; Wolf, B O

    1995-07-01

    We report the first empirical data describing the interactive effects of simultaneous changes in irradiance and convection on energy expenditure by live mammals. Whole-animal rates of solar heat gain and convective heat loss were measured for representatives of two ground squirrel species, Spermophilus lateralis and Spermophilus saturatus, that contrast in coloration. Radiative heat gain was quantified as the decrease in metabolic heat production caused by the animal's exposure to simulated solar radiation. Changes in convective heat loss were quantified as the variation in metabolic heat production caused by changes in wind speed. For both species, exposure to 780 W m-2 of simulated solar radiation significantly reduced metabolic heat production at all wind speeds measured. Reductions were greatest at lower wind speeds, reaching 42% in S. lateralis and 29% in S. saturatus. Solar heat gain, expressed per unit body surface area, did not differ significantly between the two species. This heat gain equalled 14-21% of the radiant energy intercepted by S. lateralis and 18-22% of that intercepted by S. saturatus. Body resistance, an index of animal insulation, declined by only 10% in S. saturatus and 13% in S. lateralis as wind speed increased from 0.5 to 4.0 ms-1. These data demonstrate that solar heat gain can be essentially constant, despite marked differences in animal coloration, and that variable exposure to wind and sunlight can have important consequences for both thermoregulatory stress experienced by animals and their patterns of energy allocation. PMID:7658187

  11. Local adaptation constrains the distribution potential of heat-tolerant Symbiodinium from the Persian/Arabian Gulf.

    PubMed

    D'Angelo, Cecilia; Hume, Benjamin C C; Burt, John; Smith, Edward G; Achterberg, Eric P; Wiedenmann, Jörg

    2015-12-01

    The symbiotic association of corals and unicellular algae of the genus Symbiodinium in the southern Persian/Arabian Gulf (PAG) display an exceptional heat tolerance, enduring summer peak temperatures of up to 36 °C. As yet, it is not clear whether this resilience is related to the presence of specific symbiont types that are exclusively found in this region. Therefore, we used molecular markers to identify the symbiotic algae of three Porites species along >1000 km of coastline in the PAG and the Gulf of Oman and found that a recently described species, Symbiodinium thermophilum, is integral to coral survival in the southern PAG, the world's hottest sea. Despite the geographic isolation of the PAG, we discovered that representatives of the S. thermophilum group can also be found in the adjacent Gulf of Oman providing a potential source of thermotolerant symbionts that might facilitate the adaptation of Indian Ocean populations to the higher water temperatures expected for the future. However, corals from the PAG associated with S. thermophilum show strong local adaptation not only to high temperatures but also to the exceptionally high salinity of their habitat. We show that their superior heat tolerance can be lost when these corals are exposed to reduced salinity levels common for oceanic environments elsewhere. Consequently, the salinity prevailing in most reefs outside the PAG might represent a distribution barrier for extreme temperature-tolerant coral/Symbiodinium associations from the PAG. PMID:25989370

  12. Overexpression of chloroplast-localized small molecular heat-shock protein enhances chilling tolerance in tomato plant.

    PubMed

    Wang, Li; Zhao, Chun-Mei; Wang, Yi-Ju; Liu, Jian

    2005-04-01

    There are many reports about the correlation between small molecular heat-shock protein (sHSP) and the acquirement of chilling tolerance, but no direct evidence that sHSP confers enhanced chilling tolerance to plant has been reported. A DNA construct, including tomato chloroplast-localized small molecular heat-shock protein (CPsHSP) cDNA under the control of cauliflower mosaic virus 35S (35SCaMV) promoter, was introduced into the genome of tomato plants. The chilling tolerance of the transgenic tomato lines and the non-transgenic tomato was evaluated. After exposure to chilling stress, the transgenic plants exhibited lighter chilling-injured symptoms, suffered less electrolyte leakage and less destruction of chlorophyll, accumulated less anthocyanins and less MDA and kept higher value of net photosynthetic rate, than non-transgenic plant. All results indicated consistently that transgenic tomato plants had stronger chilling tolerance. These characters are ascribed to constitutive expression of cpshsp and lead to the conclusion that HSP can enhance chilling tolerance in plant. PMID:15840935

  13. Heat removal from high temperature tubular solid oxide fuel cells utilizing product gas from coal gasifiers.

    SciTech Connect

    Parkinson, W. J. ,

    2003-01-01

    In this work we describe the results of a computer study used to investigate the practicality of several heat exchanger configurations that could be used to extract heat from tubular solid oxide fuel cells (SOFCs) . Two SOFC feed gas compositions were used in this study. They represent product gases from two different coal gasifier designs from the Zero Emission Coal study at Los Alamos National Laboratory . Both plant designs rely on the efficient use of the heat produced by the SOFCs . Both feed streams are relatively rich in hydrogen with a very small hydrocarbon content . One feed stream has a significant carbon monoxide content with a bit less hydrogen . Since neither stream has a significant hydrocarbon content, the common use of the endothermic reforming reaction to reduce the process heat is not possible for these feed streams . The process, the method, the computer code, and the results are presented as well as a discussion of the pros and cons of each configuration for each process .

  14. EFFECTS OF LOCALIZED AQUIFER BOILING ON FLUID PRODUCTION AT CERRO PRIETO.

    USGS Publications Warehouse

    Truesdell, Alfred H.; D'Amore, Franco; Nieva, David

    1984-01-01

    Localized aquifer boiling in the shallow two-phase reservoir of Cerro Prieto has produced excess steam and increased electrical output. Unfortunately it has also caused near-well mineral deposition that has decreased permeability and fluid flow. Inflow of cold water has limited the extent of aquifer boiling and permeability loss. The deeper reservoir at Cerro Prieto may need injection of cold water to decrease boiling and prevent loss of production. Refs.

  15. Adjustments in metabolic heat production by squirrel monkeys exposed to microwaves.

    PubMed

    Adair, E R; Adams, B W

    1982-04-01

    Squirrel monkeys (Saimiri sciureus) were exposed in the far field of a horn antenna to both brief (10-min) and prolonged (90-min) periods of 2,450-MHz continuous microwaves. Ambient temperature (Ta) was constant at 15, 20, or 25 degrees C. Microwave power density ranged from 2.5 to 10 mW/cm2, representing a range of whole-body energy absorption from 0.4 to 1.5 W/kg. Reliable reductions in metabolic heat production (M), calculated from oxygen deficit in the monkey's expired air, were initiated at all Ta by 10-min whole-body exposures to power densities of 4 mW/cm2 (2 monkeys) or 6 mW/cm2 (1 monkey) and above. The magnitude of M reduction was linearly related to microwave intensity above the threshold level. Termination of microwaves was followed by a rapid M rebound. The change in M produced by a given power density was nearly the same in Ta = 15 and 20 degrees C. During 90-min exposures at Ta = 20 degrees C, the vigorous M reduction to microwave onset adapted slowly, ensuring continual precise regulation of internal body temperature. Thus cold-exposed endotherms readily compensate for microwave-induced body heating by reducing endogenous heat production. PMID:7085406

  16. Gas production and transport during bench-scale electrical resistance heating of water and trichloroethene

    NASA Astrophysics Data System (ADS)

    Hegele, P. R.; Mumford, K. G.

    2014-09-01

    The effective remediation of chlorinated solvent source zones using in situ thermal treatment requires successful capture of gas that is produced. Replicate electrical resistance heating experiments were performed in a thin bench-scale apparatus, where water was boiled and pooled dense non-aqueous phase liquid (DNAPL) trichloroethene (TCE) and water were co-boiled in unconsolidated silica sand. Quantitative light transmission visualization was used to assess gas production and transport mechanisms. In the water boiling experiments, nucleation, growth and coalescence of the gas phase into connected channels were observed at critical gas saturations of Sgc = 0.233 0.017, which allowed for continuous gas transport out of the sand. In experiments containing a colder region above a target heated zone, condensation prevented the formation of steam channels and discrete gas clusters that mobilized into colder regions were trapped soon after discontinuous transport began. In the TCE-water experiments, co-boiling at immiscible fluid interfaces resulted in discontinuous gas transport above the DNAPL pool. Redistribution of DNAPL was also observed above the pool and at the edge of the vapor front that propagated upwards through colder regions. These results suggest that the subsurface should be heated to water boiling temperatures to facilitate gas transport from specific locations of DNAPL to extraction points and reduce the potential for DNAPL redistribution. Decreases in electric current were observed at the onset of gas phase production, which suggests that coupled electrical current and temperature measurements may provide a reliable metric to assess gas phase development.

  17. MTT assay for cell viability: Intracellular localization of the formazan product is in lipid droplets.

    PubMed

    Stockert, Juan C; Blázquez-Castro, Alfonso; Cañete, Magdalena; Horobin, Richard W; Villanueva, Angeles

    2012-12-01

    Although MTT is widely used to assess cytotoxicity and cell viability, the precise localization of its reduced formazan product is still unclear. In the present study the localization of MTT formazan was studied by direct microscopic observation of living HeLa cells and by colocalization analysis with organelle-selective fluorescent probes. MTT formazan granules did not colocalize with mitochondria as revealed by rhodamine 123 labeling or autofluorescence. Likewise, no colocalization was observed between MTT formazan granules and lysosomes labeled by neutral red. Taking into account the lipophilic character and lipid solubility of MTT formazan, an evaluation of the MTT reaction was performed after treatment of cells with sunflower oil emulsions to induce a massive occurrence of lipid droplets. Under this condition, lipid droplets revealed a large amount of MTT formazan deposits. Kinetic studies on the viability of MTT-treated cells showed no harmful effects at short times. Quantitative structure-activity relations (QSAR) models were used to predict and explain the localization of both the MTT tetrazolium salt and its formazan product. These predictions were in agreement with experimental observations on the accumulation of MTT formazan product in lipid droplets. PMID:22341561

  18. Thermal Energy Consumption in the Heat-Technology Production of Solid Composite Fuel From Low-Grade Raw Materials

    NASA Astrophysics Data System (ADS)

    Tabakaev, Roman; Astafev, Alexander; Kazakov, Alexander; Zavorin, Alexander

    2016-02-01

    An evaluation is made of the thermal energy consumed in the heat-technology production of solid composite fuel from low-grade organic raw materials. It is shown that the heat of decomposition of the organic mass and the combustion of the by-products of heat-technology may be sufficient to cover all the energy needs for processing peat, brown coal and wood chips. Producing solid composite fuel from sapropel requires external resources to compensate for part of the heat consumed. Calculations show that it is possible for the thermal processing of raw materials to proceed autothermally due to the heat of decomposition when the moisture content at the reactor inlet is limited: for peat it should be no more than 35%, 54% for brown coal, and 37% for wood chips. The low heat of decomposition of the sapropel organic mass means that its thermal processing cannot proceed autothermally.

  19. Thermotolerant bacteriocin-producing lactic acid bacteria isolated from thai local fermented foods and their bacteriocin productivity.

    PubMed

    Leelavatcharamas, Vichai; Arbsuwan, Nida; Apiraksakorn, Jirawan; Laopaiboon, Pattana; Kishida, Masao

    2011-03-01

    Twenty-one samples of Thai local fermented foods were screened for thermotolerant bacteriocin-producing lactic acid bacteria. From 529 isolates of lactic acid bacteria, 121 isolates were able to inhibit the growth of certain bacterial strains. Of these 121 isolates, only 11 produced antibacterial agents that were capable of inhibiting the growth of multiple bacterial strains in a liquid medium. One strain (KKU 170) of these 11 isolates produced an antibacterial agent that could strongly inhibit the growth of selected strains of gram-positive bacteria including Listeria sp. The antibacterial agent produced by the strain KKU 170 was identified as a bacteriocin since it was inactivated by proteinase K treatment. The strain KKU 170 was identified as Pediococcus acidilactici by both biochemical tests and molecular biological techniques. Optimal production of bacteriocin by the strain KKU 170 was found in culture medium containing 0.2% glucose, at an initial culture pH of 6.5, and temperature of 45 C. The maximum bacteriocin activity (1600 AU ml(-1)) was reached at the late exponential phase of growth and displayed primary metabolite production. The partially purified bacteriocin of the strain KKU 170 was tolerant to heat treatment at 121 C for 30 min. PMID:21467627

  20. Skylab and solar exploration. [chromosphere-corona structure, energy production and heat transport processes

    NASA Technical Reports Server (NTRS)

    Von Puttkamer, J.

    1973-01-01

    Review of some of the findings concerning solar structure, energy production, and heat transport obtained with the aid of the manned Skylab space station observatory launched on May 14, 1973. Among the topics discussed are the observation of thermonuclear fusion processes which cannot be simulated on earth, the observation of short-wave solar radiation not visible to observers on earth, and the investigation of energy-transport processes occurring in the photosphere, chromosphere, and corona. An apparent paradox is noted in that the cooler chromosphere is heating the hotter corona, seemingly in defiance of the second law of thermodynamics, thus suggesting that a nonthermal mechanism underlies the energy transport. Understanding of this nonthermal mechanism is regarded as an indispensable prerequisite for future development of plasma systems for terrestrial applications.

  1. Effect of Catalytic Pyrolysis Conditions Using Pulse Current Heating Method on Pyrolysis Products of Wood Biomass

    PubMed Central

    Honma, Sensho; Hata, Toshimitsu; Watanabe, Takashi

    2014-01-01

    The influence of catalysts on the compositions of char and pyrolysis oil obtained by pyrolysis of wood biomass with pulse current heating was studied. The effects of catalysts on product compositions were analyzed using GC-MS and TEM. The compositions of some aromatic compounds changed noticeably when using a metal oxide species as the catalyst. The coexistence or dissolution of amorphous carbon and iron oxide was observed in char pyrolyzed at 800C with Fe3O4. Pyrolysis oil compositions changed remarkably when formed in the presence of a catalyst compared to that obtained from the uncatalyzed pyrolysis of wood meal. We observed a tendency toward an increase in the ratio of polyaromatic hydrocarbons in the pyrolysis oil composition after catalytic pyrolysis at 800C. Pyrolysis of biomass using pulse current heating and an adequate amount of catalyst is expected to yield a higher content of specific polyaromatic compounds. PMID:25614894

  2. Crustal radiogenic heat production and the selective survival of ancient continental crust

    NASA Technical Reports Server (NTRS)

    Morgan, P.

    1985-01-01

    It is pointed out that the oldest terrestrial rocks have so far revealed no evidence of the impact phase of earth evolution. This observation suggests that processes other than impact were dominant at the time of stabilization of these units. However, a use of the oldest terrestrial rocks as a sample of the early terrestrial crust makes it necessary to consider the possibility that these rocks may represent a biased sample. In the present study, the global continental heat flow data set is used to provide further evidence that potassium, uranium, and thorium abundances are, on the average, low in surviving Archean crust relative to younger continental crust. An investigation is conducted of the implications of relatively low crustal radiogenic heat production to the stabilization of early continental crust, and possible Archean crustal stabilization models are discussed.

  3. Crustal radiogenic heat production and the selective survival of ancient continental crust

    NASA Technical Reports Server (NTRS)

    Morgan, P.

    1985-01-01

    It is pointed out that the oldest terrestrial rocks have so far revealed no evidence of the impact phase of Earth evolution. This observation suggests that processes other than impact were dominant at the time of stabilization of these units. However, a use of the oldest terrestrial rocks as a sample of the early terrestrial crust makes it necessary to consider the possibility that these rocks may represent a biased sample. In the present study, the global continental heat flow data set is used to provide further evidence that potassium, uranium, and thorium abundances are, on the average, low in surviving Archean crust relative to younger continental crust. An investigation is conducted of the implications of relatively low crustal radiogenic heat production to the stabilization of early continental crust, and possible Archean crustal stabilization models are discussed.

  4. Thermal Gains Through Collective Metabolic Heat Production in Social Caterpillars of Eriogaster lanestris

    NASA Astrophysics Data System (ADS)

    Ruf, C.; Fiedler, K.

    We investigated thermal characteristics of aggregations of social, tent-building caterpillars of the small eggar moth Eriogaster lanestris (Lepidoptera: Lasiocampidae). The highly synchronous behavior of individuals of the colony has important consequences for their thermal ecology. Air temperature in the tent fluctuates according to the caterpillars' activity: air temperature slowly rises about 2.5-3 C above the surroundings when caterpillars aggregate in the tent after feeding and decreases rapidly when the larvae leave the tent. Thermal energy can be stored for a few hours when ambient temperature drops. Experiments show that metabolic heat production sufficiently explains this effect. As even minor additional heat gain may reduce developmental time, aggregating in the tent may thus confer selective advantages under overcast weather or at night, when behavioral thermoregulation through basking is not possible.

  5. Improved irradiances for use in ocean heating, primary production, and photo-oxidation calculations.

    PubMed

    Mobley, Curtis D; Boss, Emmanuel S

    2012-09-20

    Accurate calculation of underwater light is fundamental to predictions of upper-ocean heating, primary production, and photo-oxidation. However, most ocean models simulating these processes do not yet incorporate radiative transfer modules for their light calculations. Such models are often driven by above-surface, broadband, daily averaged irradiance or photosynthetically available radiation (PAR) values obtained from climatology or satellite observations, sometimes without correction for sea-surface reflectance, even though surface reflectance can reduce in-water values by more than 20%. We present factors computed by a radiative transfer code that can be used to convert above-surface values in either energy or quantum units to in-water net irradiance, as needed for calculations of water heating, and to in-water PAR, as needed for calculations of photosynthesis and photo-oxidation. PMID:23033025

  6. Comment on 'A reinterpretation of the linear heat flow and heat production relationship for the exponential model of the heat production in the crust' by R.N. Singh & J.G. Negi.

    USGS Publications Warehouse

    Lachenbruch, A.H.

    1980-01-01

    In their recent paper, Singh & Negi, (This journal, 57, 741-744) contend that if thd slope of the empirical linear relation between heat flow and heat production is interpreted as the decay-length of an exponential depth-distribution of sources, a discrepancy rises, whereas if it is interpreted as the depth of a step distribution, it does not. I should like to point out that their discrepancy follows from their arbitrary assumption of one of a range of physical possibilities unconstrained by the observations; with an equally valid alternate assumption (Lachenbruch 1970) the discrepancy disappears. In any case such discrepancies are probably minor compared to physical difficulties that arise from the step model, and to uncertainties introduced by other assumptions in any simple model.-Author

  7. Solar radiation during rewarming from torpor in elephant shrews: supplementation or substitution of endogenous heat production?

    PubMed

    Thompson, Michelle L; Mzilikazi, Nomakwezi; Bennett, Nigel C; McKechnie, Andrew E

    2015-01-01

    Many small mammals bask in the sun during rewarming from heterothermy, but the implications of this behaviour for their energy balance remain little understood. Specifically, it remains unclear whether solar radiation supplements endogenous metabolic thermogenesis (i.e., rewarming occurs through the additive effects of internally-produced and external heat), or whether solar radiation reduces the energy required to rewarm by substituting (i.e, replacing) metabolic heat production. To address this question, we examined patterns of torpor and rewarming rates in eastern rock elephant shrews (Elephantulus myurus) housed in outdoor cages with access to either natural levels of solar radiation or levels that were experimentally reduced by means of shade cloth. We also tested whether acclimation to solar radiation availability was manifested via phenotypic flexibility in basal metabolic rate (BMR), non-shivering thermogenesis (NST) capacity and/or summit metabolism (Msum). Rewarming rates varied significantly among treatments, with elephant shrews experiencing natural solar radiation levels rewarming faster than conspecifics experiencing solar radiation levels equivalent to approximately 20% or 40% of natural levels. BMR differed significantly between individuals experiencing natural levels of solar radiation and conspecifics experiencing approximately 20% of natural levels, but no between-treatment difference was evident for NST capacity or Msum. The positive relationship between solar radiation availability and rewarming rate, together with the absence of acclimation in maximum non-shivering and total heat production capacities, suggests that under the conditions of this study solar radiation supplemented rather than substituted metabolic thermogenesis as a source of heat during rewarming from heterothermy. PMID:25853244

  8. Solar Radiation during Rewarming from Torpor in Elephant Shrews: Supplementation or Substitution of Endogenous Heat Production?

    PubMed Central

    Thompson, Michelle L.; Mzilikazi, Nomakwezi; Bennett, Nigel C.; McKechnie, Andrew E.

    2015-01-01

    Many small mammals bask in the sun during rewarming from heterothermy, but the implications of this behaviour for their energy balance remain little understood. Specifically, it remains unclear whether solar radiation supplements endogenous metabolic thermogenesis (i.e., rewarming occurs through the additive effects of internally-produced and external heat), or whether solar radiation reduces the energy required to rewarm by substituting (i.e, replacing) metabolic heat production. To address this question, we examined patterns of torpor and rewarming rates in eastern rock elephant shrews (Elephantulus myurus) housed in outdoor cages with access to either natural levels of solar radiation or levels that were experimentally reduced by means of shade cloth. We also tested whether acclimation to solar radiation availability was manifested via phenotypic flexibility in basal metabolic rate (BMR), non-shivering thermogenesis (NST) capacity and/or summit metabolism (Msum). Rewarming rates varied significantly among treatments, with elephant shrews experiencing natural solar radiation levels rewarming faster than conspecifics experiencing solar radiation levels equivalent to approximately 20% or 40% of natural levels. BMR differed significantly between individuals experiencing natural levels of solar radiation and conspecifics experiencing approximately 20% of natural levels, but no between-treatment difference was evident for NST capacity or Msum. The positive relationship between solar radiation availability and rewarming rate, together with the absence of acclimation in maximum non-shivering and total heat production capacities, suggests that under the conditions of this study solar radiation supplemented rather than substituted metabolic thermogenesis as a source of heat during rewarming from heterothermy. PMID:25853244

  9. Experience of BESIII data production with local cluster and distributed computing model

    NASA Astrophysics Data System (ADS)

    Deng, Z. Y.; Li, W. D.; Lin, L.; Liu, H. M.; Nicholson, C.; Sun, Y. Z.; Zhang, X. M.; Zhemchugov, A.

    2012-12-01

    The BES III detector is a new spectrometer which works on the upgraded high-luminosity collider, BEPCII. The BES III experiment studies physics in the tau-charm energy region from 2 GeV to 4.6 GeV . From 2009 to 2011, BEPCII has produced 106M ?(2S) events, 225M J/? events, 2.8 fb-1 ?(3770) data, and 500 pb-1 data at 4.01 GeV. All the data samples were processed successfully and many important physics results have been achieved based on these samples. Doing data production correctly and efficiently with limited CPU and storage resources is a big challenge. This paper will describe the implementation of the experiment-specific data production for BESIII in detail, including data calibration with event-level parallel computing model, data reconstruction, inclusive Monte Carlo generation, random trigger background mixing and multi-stream data skimming. Now, with the data sample increasing rapidly, there is a growing demand to move from solely using a local cluster to a more distributed computing model. A distributed computing environment is being set up and expected to go into production use in 2012. The experience of BESIII data production, both with a local cluster and with a distributed computing model, is presented here.

  10. Processes governing phytoplankton blooms in estuaries. I: The local production-loss balance

    USGS Publications Warehouse

    Lucas, L.V.; Koseff, Jeffrey R.; Cloern, J.E.; Monismith, Stephen G.; Thompson, J.K.

    1999-01-01

    The formation and spatial distribution of phytoplankton blooms in estuaries are controlled by (1) local mechanisms, which determine the production-loss balance for a water column at a particular spatial location (i.e. control if a bloom is possible), and (2) transport-related mechanisms, which govern biomass distribution (i.e. control if and where a bloom actually occurs). In this study, the first of a 2-paper series, we use a depth-averaged numerical model as a theoretical tool to describe how interacting local conditions (water column height, light availability, benthic grazing) influence the local balance between phytoplankton sources and sinks. We also explore trends in the spatial variability of the production-loss balance across the topographic gradients between deep channels and lateral shoals which are characteristic of shallow estuaries. For example, under conditions of high turbidity and slow benthic grazing the highest rates of phytoplankton population growth are found in the shallowest regions. On the other hand, with low turbidity and rapid benthic grazing the highest growth rates occur in the deeper areas. We also explore the effects of semidiurnal tidal variation in water column height, as well as spring-neap variability. Local population growth in the shallowest regions is very sensitive to tidal-scale shallowing and deepening of the water column, especially in the presence of benthic grazing. A spring-neap signal in population growth rate is also prominent in the shallow areas. Population growth in deeper regions is less sensitive to temporal variations in tidal elevation. These results show that both shallow and deep regions of estuaries can act as sources or sinks for phytoplankton biomass, depending on the local conditions of mean water column height, tidal amplitude, light-limited growth rate, and consumption by grazers.

  11. The effects of localized heating and disbudding on cambial reactivation and formation of earlywood vessels in seedlings of the deciduous ring-porous hardwood, Quercus serrata

    PubMed Central

    Kudo, Kayo; Nabeshima, Eri; Begum, Shahanara; Yamagishi, Yusuke; Nakaba, Satoshi; Oribe, Yuichiro; Yasue, Koh; Funada, Ryo

    2014-01-01

    Background and Aims The networks of vessel elements play a vital role in the transport of water from roots to leaves, and the continuous formation of earlywood vessels is crucial for the growth of ring-porous hardwoods. The differentiation of earlywood vessels is controlled by external and internal factors. The present study was designed to identify the limiting factors in the induction of cambial reactivation and the differentiation of earlywood vessels, using localized heating and disbudding of dormant stems of seedlings of a deciduous ring-porous hardwood, Quercus serrata. Methods Localized heating was achieved by wrapping an electric heating ribbon around stems. Disbudding involved removal of all buds. Three treatments were initiated on 1 February 2012, namely heating, disbudding and a combination of heating and disbudding, with untreated dormant stems as controls. Cambial reactivation and differentiation of vessel elements were monitored by light and polarized-light microscopy, and the growth of buds was followed. Key Results Cambial reactivation and differentiation of vessel elements occurred sooner in heated seedlings than in non-heated seedlings before bud break. The combination of heating and disbudding of seedlings also resulted in earlier cambial reactivation and differentiation of first vessel elements than in non-heated seedlings. A few narrow vessel elements were formed during heating after disbudding, while many large earlywood vessel elements were formed in heated seedlings with buds. Conclusions The results suggested that, in seedlings of the deciduous ring-porous hardwood Quercus serrata, elevated temperature was a direct trigger for cambial reactivation and differentiation of first vessel elements. Bud growth was not essential for cambial reactivation and differentiation of first vessel elements, but might be important for the continuous formation of wide vessel elements. PMID:24685716

  12. Predictions and measurements of heat production and food and water requirements of Holstein calves in different environments

    SciTech Connect

    Gebremedhin, K.G.; Cramer, C.O.; Porter, W.P.

    1981-01-01

    Heat losses computed from respiratory gas analysis were used to determine animal food and water requirements. The specific heat production (keal kg-h) of Holstein calves were determined from continuously recording the respiratory gas exchange in an indirect calorimetric system. Growth rates varied by a factor of 30 over the measured temperature range for the same food investment.

  13. Citrate-capped gold nanoparticle electrophoretic heat production in response to a time-varying radiofrequency electric-field

    PubMed Central

    Corr, Stuart J.; Raoof, Mustafa; Mackeyev, Yuri; Phounsavath, Sophia; Cheney, Matthew A.; Cisneros, Brandon T.; Shur, Michael; Gozin, Michael; McNally, Patrick J.; Wilson, Lon J.; Curley, Steven A.

    2013-01-01

    The evaluation of heat production from gold nanoparticles (AuNPs) irradiated with radiofrequency (RF) energy has been problematic due to Joule heating of their background ionic buffer suspensions. Insights into the physical heating mechanism of nanomaterials under RF excitations must be obtained if they are to have applications in fields such as nanoparticle-targeted hyperthermia for cancer therapy. By developing a purification protocol which allows for highly-stable and concentrated solutions of citrate-capped AuNPs to be suspended in high-resistivity water, we show herein, for the first time, that heat production is only evident for AuNPs of diameters ? 10 nm, indicating a unique size-dependent heating behavior not previously observed. Heat production has also shown to be linearly dependent on both AuNP concentration and total surface area, and severely attenuated upon AuNP aggregation. These relationships have been further validated using permittivity analysis across a frequency range of 10 MHz to 3 GHz, as well as static conductivity measurements. Theoretical evaluations suggest that the heating mechanism can be modeled by the electrophoretic oscillation of charged AuNPs across finite length scales in response to a time-varying electric field. It is anticipated these results will assist future development of nanoparticle-assisted heat production by RF fields for applications such as targeted cancer hyperthermia. PMID:23795228

  14. Practical considerations for maximizing heat production in a novel thermobrachytherapy seed prototype

    PubMed Central

    Gautam, Bhoj; Warrell, Gregory; Shvydka, Diana; Subramanian, Manny; Ishmael Parsai, E.

    2014-01-01

    Purpose: A combination of hyperthermia and radiation in the treatment of cancer has been proven to provide better tumor control than radiation administered as a monomodality, without an increase in complications or serious toxicities. Moreover, concurrent administration of hyperthermia and radiation displays synergistic enhancement, resulting in greater tumor cell killing than hyperthermia and radiation delivered separately. The authors have designed a new thermobrachytherapy (TB) seed, which serves as a source of both radiation and heat for concurrent brachytherapy and hyperthermia treatments when implanted in solid tumors. This innovative seed, similar in size and geometry to conventional seeds, will have self-regulating thermal properties. Methods: The new seed's geometry is based on the standard BEST Model 2301 125I seed, resulting in very similar dosimetric properties. The TB seed generates heat when placed in an oscillating magnetic field via induction heating of a ferromagnetic NiCu alloy core that replaces the tungsten radiographic marker of the standard Model 2301. The alloy composition is selected to undergo a Curie transition near 50?C, drastically decreasing power production at higher temperatures and providing for temperature self-regulation. Here, the authors present experimental studies of the magnetic properties of NiCu alloy material, the visibility of TB seeds in radiographic imaging, and the ability of seed prototypes to uniformly heat tissue to a desirable temperature. Moreover, analyses are presented of magnetic shielding and thermal expansion of the TB seed, as well as matching of radiation dose to temperature distributions for a short interseed distance in a given treatment volume. Results: Annealing the NiCu alloy has a significant effect on its magnetization properties, increasing the sharpness of the Curie transition. The TB seed preserves the radiographic properties of the BEST 2301 seed in both plain x rays and CT images, and a preliminary experiment demonstrates thermal self-regulation and adequate heating of a tissue-mimicking phantom by seed prototypes. The effect of self-shielding of the seed against the external magnetic field is small, and only minor thermal stress is induced in heating of the seeds from room temperature to well above the seed operating temperature. With proper selection of magnetic field parameters, the thermal dose distribution of an arrangement of TB and hyperthermia-only seeds may be made to match with its radiation dose distribution. Conclusions: The presented analyses address several practical considerations for manufacturing of the proposed TB seeds and identify critical issues for the prototype implementation. The authors preliminary experiments demonstrate close agreement with the modeling results, confirming the feasibility of combining sources of heat and radiation into a single thermobrachytherapy seed. PMID:24506651

  15. Practical considerations for maximizing heat production in a novel thermobrachytherapy seed prototype

    SciTech Connect

    Gautam, Bhoj; Warrell, Gregory; Shvydka, Diana; Ishmael Parsai, E.; Subramanian, Manny

    2014-02-15

    Purpose: A combination of hyperthermia and radiation in the treatment of cancer has been proven to provide better tumor control than radiation administered as a monomodality, without an increase in complications or serious toxicities. Moreover, concurrent administration of hyperthermia and radiation displays synergistic enhancement, resulting in greater tumor cell killing than hyperthermia and radiation delivered separately. The authors have designed a new thermobrachytherapy (TB) seed, which serves as a source of both radiation and heat for concurrent brachytherapy and hyperthermia treatments when implanted in solid tumors. This innovative seed, similar in size and geometry to conventional seeds, will have self-regulating thermal properties. Methods: The new seed's geometry is based on the standard BEST Model 2301{sup 125}I seed, resulting in very similar dosimetric properties. The TB seed generates heat when placed in an oscillating magnetic field via induction heating of a ferromagnetic NiCu alloy core that replaces the tungsten radiographic marker of the standard Model 2301. The alloy composition is selected to undergo a Curie transition near 50?C, drastically decreasing power production at higher temperatures and providing for temperature self-regulation. Here, the authors present experimental studies of the magnetic properties of NiCu alloy material, the visibility of TB seeds in radiographic imaging, and the ability of seed prototypes to uniformly heat tissue to a desirable temperature. Moreover, analyses are presented of magnetic shielding and thermal expansion of the TB seed, as well as matching of radiation dose to temperature distributions for a short interseed distance in a given treatment volume. Results: Annealing the NiCu alloy has a significant effect on its magnetization properties, increasing the sharpness of the Curie transition. The TB seed preserves the radiographic properties of the BEST 2301 seed in both plain x rays and CT images, and a preliminary experiment demonstrates thermal self-regulation and adequate heating of a tissue-mimicking phantom by seed prototypes. The effect of self-shielding of the seed against the external magnetic field is small, and only minor thermal stress is induced in heating of the seeds from room temperature to well above the seed operating temperature. With proper selection of magnetic field parameters, the thermal dose distribution of an arrangement of TB and hyperthermia-only seeds may be made to match with its radiation dose distribution. Conclusions: The presented analyses address several practical considerations for manufacturing of the proposed TB seeds and identify critical issues for the prototype implementation. The authors preliminary experiments demonstrate close agreement with the modeling results, confirming the feasibility of combining sources of heat and radiation into a single thermobrachytherapy seed.

  16. Practical considerations for maximizing heat production in a novel thermobrachytherapy seed prototype

    SciTech Connect

    Gautam, Bhoj; Warrell, Gregory; Shvydka, Diana; Ishmael Parsai, E.; Subramanian, Manny

    2014-02-15

    Purpose: A combination of hyperthermia and radiation in the treatment of cancer has been proven to provide better tumor control than radiation administered as a monomodality, without an increase in complications or serious toxicities. Moreover, concurrent administration of hyperthermia and radiation displays synergistic enhancement, resulting in greater tumor cell killing than hyperthermia and radiation delivered separately. The authors have designed a new thermobrachytherapy (TB) seed, which serves as a source of both radiation and heat for concurrent brachytherapy and hyperthermia treatments when implanted in solid tumors. This innovative seed, similar in size and geometry to conventional seeds, will have self-regulating thermal properties. Methods: The new seed's geometry is based on the standard BEST Model 2301{sup 125}I seed, resulting in very similar dosimetric properties. The TB seed generates heat when placed in an oscillating magnetic field via induction heating of a ferromagnetic Ni–Cu alloy core that replaces the tungsten radiographic marker of the standard Model 2301. The alloy composition is selected to undergo a Curie transition near 50 °C, drastically decreasing power production at higher temperatures and providing for temperature self-regulation. Here, the authors present experimental studies of the magnetic properties of Ni–Cu alloy material, the visibility of TB seeds in radiographic imaging, and the ability of seed prototypes to uniformly heat tissue to a desirable temperature. Moreover, analyses are presented of magnetic shielding and thermal expansion of the TB seed, as well as matching of radiation dose to temperature distributions for a short interseed distance in a given treatment volume. Results: Annealing the Ni–Cu alloy has a significant effect on its magnetization properties, increasing the sharpness of the Curie transition. The TB seed preserves the radiographic properties of the BEST 2301 seed in both plain x rays and CT images, and a preliminary experiment demonstrates thermal self-regulation and adequate heating of a tissue-mimicking phantom by seed prototypes. The effect of self-shielding of the seed against the external magnetic field is small, and only minor thermal stress is induced in heating of the seeds from room temperature to well above the seed operating temperature. With proper selection of magnetic field parameters, the thermal dose distribution of an arrangement of TB and hyperthermia-only seeds may be made to match with its radiation dose distribution. Conclusions: The presented analyses address several practical considerations for manufacturing of the proposed TB seeds and identify critical issues for the prototype implementation. The authors’ preliminary experiments demonstrate close agreement with the modeling results, confirming the feasibility of combining sources of heat and radiation into a single thermobrachytherapy seed.

  17. Local government guide to the emerging technologies of energy-efficient motors and heat pumps. Energy technology report of the energy task force of the urban consortium

    SciTech Connect

    1980-01-01

    Information is presented to provide a local government manager with a basic background in energy efficient motors and heat pump technologies. An overview of each technology and the issues and considerations associated with their application are presented. Discussions cover installation and maintenance requirements, equipment availability, costs and risks/benefits. Data describing demonstration sites for solar assisted heat pump systems and contacts for further information are provided.

  18. Biobutanol production by a new local isolate of Clostridium acetobutylicum YM1

    NASA Astrophysics Data System (ADS)

    Al-Shorgani, Najeeb Kaid; Tibin, El Mubarak; Kalil, Mohd Sahaid; Yusoff, Wan Mohtar Wan; Hamid, Aidil Abdul

    2014-09-01

    Increasing demand of energy and awareness about environmental pollution has led to increase interest in alternative, clean and renewable energy sources. Biobutanol is considered as the candidate liquid biofuel to replace gasoline. In this study, the capability of a newly isolated strain of local Clostridium acetobutylicum YM1 was tested to produce biobutanol in batch fermentation. Various culture conditions including glucose concentration, initial pH, incubation temperature and inoculum size were investigated for their effects on production of biobutanol using strain YM1. The results showed that the optimal biobutanol production was obtained at glucose concentration 50 g/L, initial pH 6.2, temperature 30C and inoculum size 10%. These results show that C. acetobutylicum YM1 as a mesophilic bacterium is a potential candidate for biobutanol production.

  19. Biomass and lipid production of a local isolate Chlorella sorokiniana under mixotrophic growth conditions.

    PubMed

    Juntila, D J; Bautista, M A; Monotilla, W

    2015-09-01

    A local Chlorella sp. isolate with 97% rbcL sequence identity to Chlorella sorokiniana was evaluated in terms of its biomass and lipid production under mixotrophic growth conditions. Glucose-supplemented cultures exhibited increasing growth rate and biomass yield with increasing glucose concentration. Highest growth rate and biomass yield of 1.602 day(-1) and 687.5 mg L(-1), respectively, were achieved under 2 g L(-1) glucose. Nitrogen starvation up to 75% in the 1.0 g L(-1) glucose-supplemented culture was done to induce lipid accumulation and did not significantly affect the growth. Lipid content ranges from 20% to 27% dry weight. Nile Red staining showed more prominent neutral lipid bodies in starved mixotrophic cultures. C. sorokiniana exhibited enhanced biomass production under mixotrophy and more prominent neutral lipid accumulation under nitrogen starvation with no significant decrease in growth; hence, this isolate could be further studied to establish its potential for biodiesel production. PMID:25847795

  20. Fasting heat production and metabolic BW in group-housed broilers.

    PubMed

    Noblet, J; Dubois, S; Lasnier, J; Warpechowski, M; Dimon, P; Carré, B; van Milgen, J; Labussière, E

    2015-07-01

    Fasting heat production (FHP) is used for characterizing the basal metabolic rate of animals and the corresponding maintenance energy requirements and in the calculation of net energy value of feeds. In broilers, the most recent FHP estimates were obtained in the 1980s in slow-growing and fatter birds than nowadays. The FHP values (n=73; six experiments) measured in 3 to 6-week-old modern lines of broilers weighing 0.6 to 2.8 kg and growing at 80 to 100 g/day were used to update these literature values. Each measurement was obtained in a group of fasting broilers (5 to 14 birds) kept in a respiration chamber for at least 24 h. The FHP estimate corresponds to the asymptotic heat production corrected for zero physical activity obtained by modeling the decrease in heat production during the fasting day. The compilation of these data indicates that FHP was linearly related to the BW(0.70) (in kg), which can be considered as the metabolic BW of modern broilers. The 0.70 exponent differs from the conventional value of 0.75 used for mature animals. The FHP per kg of BW(0.70) ranged between 410 and 460 kJ/day according to the experiment (P<0.01). An experiment conducted with a shorter duration of fasting (16 h) indicated that FHP values are higher than those obtained over at least 24 h of fasting. Our values are similar to those obtained previously on fatter and slow-growing birds, even though the comparison is difficult since measurement conditions and methodologies have changed during the last 30 years. The FHP values obtained in our trials represent a basis for energy nutrition of modern broilers. PMID:25772629

  1. Using flowering and heat-loss models for improving greenhouse energy-use efficiency in annual bedding plant production

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In temperate climates, annual bedding plants are typically produced in heated greenhouses from late winter through early summer. Temperature, photoperiod, light intensity, and transplant date are commonly manipulated during commercial production so that plants are in flower for predetermined market ...

  2. Xylanase production with xylan rich lignocellulosic wastes by a local soil isolate of Trichoderma viride

    PubMed Central

    Goyal, Meenakshi; Kalra, K.L.; Sareen, V.K.; Soni, G.

    2008-01-01

    In the present study, cultural and nutritional conditions for enhanced production of xylanase by a local soil isolate of Trichoderma viride, using various lignocellulosic substrates in submerged culture fermentation have been optimized. Of the lignocellulosics used, maize straw was the best inducer followed by jowar straw for xylanase production. The highest activity achieved was between 14 to 17 days of fermentation. A continuous increase in xylanase production was observed with increasing level of lignocellulosics in the medium and highest activity was observed with maize straw at 5% level. Xylanase production with higher levels of lignocellulosics (3 to 5%) of maize, jowar and barseem was found to be higher as compared to that with commercial xylan as carbon source. Sodium nitrate was the best nitrogen source among the six sources used. Maximum xylanase production was achieved with initial medium pH of 3.5–4.0 and incubation temperature of 25ºC.The enzyme preparation was effective in bringing about saccharification of different lignocellulosics. The xylanase production could be further improved by using alkali treated straw as carbon source. PMID:24031262

  3. Assessing complexity of skin blood flow oscillations in response to locally applied heating and pressure in rats: Implications for pressure ulcer risk

    NASA Astrophysics Data System (ADS)

    Liao, Fuyuan; O'Brien, William D.; Jan, Yih-Kuen

    2013-10-01

    The objective of this study was to investigate the effects of local heating on the complexity of skin blood flow oscillations (BFO) under prolonged surface pressure in rats. Eleven Sprague-Dawley rats were studied: 7 rats underwent surface pressure with local heating (?t=10 C) and 4 rats underwent pressure without heating. A pressure of 700 mmHg was applied to the right trochanter area of rats for 3 h. Skin blood flow was measured using laser Doppler flowmetry. The loading period was divided into nonoverlapping 30 min epochs. For each epoch, multifractal detrended fluctuation analysis (MDFA) was utilized to compute DFA coefficients and complexity of endothelial related metabolic, neurogenic, and myogenic frequencies of BFO. The results showed that under surface pressure, local heating led to a significant decrease in DFA coefficients of myogenic frequency during the initial epoch of loading period, a sustained decrease in complexity of myogenic frequency, and a significantly higher degree of complexity of metabolic frequency during the later phase of loading period. Surrogate tests showed that the reduction in complexity of myogenic frequency was associated with a loss of nonlinearity whereas increased complexity of metabolic frequency was associated with enhanced nonlinearity. Our results indicate that increased metabolic activity and decreased myogenic response due to local heating manifest themselves not only in magnitudes of metabolic and myogenic frequencies but also in their structural complexity. This study demonstrates the feasibility of using complexity analysis of BFO to monitor the ischemic status of weight-bearing skin and risk of pressure ulcers.

  4. Effect of nozzle configuration on transport in the stagnation zone of axisymmetric, impinging free-surface liquid jets: Part 2-local heat transfer

    SciTech Connect

    Pan, Y.; Stevens, J.; Webb, B.W. )

    1992-11-01

    This is the second of a two-part study on the flow structure and heat transfer characteristics of turbulent, free-surface liquid jets. Part 2 deals with the effect of selected nozzle configurations on the local heat transfer in the stagnation zone. Infrared techniques have been used to characterize the local heat transfer for the four nozzle configurations whose mean and turbulent flow structure was detailed in Part 1. The results show that for identical jet Reynolds numbers, significant differences exist in the magnitudes of the local Nusselt number for the nozzle types studied. Differences of approximately 40 percent were observed. Local heat transfer results reveal that for already turbulent jets, the mean radial velocity gradient appears to be more influential in determining the heat transfer than incremental changes in the level of turbulence (as measured by the radial component of the fluctuations). An empirical correlation of the experimental data supports this conclusion, and reveals that the stagnation Nusselt number is affected independently by the jet Reynolds number and the dimensionless mean radial velocity gradient. 21 refs., 6 figs.

  5. Experimental investigation of the unusual behavior of local heat transfer coefficient in the transition region of a circular tube with a bell-mouth entrance

    SciTech Connect

    Tam, L.M.; Ghajar, A.J.

    1996-12-31

    The local heat transfer characteristics for ethylene glycol water mixtures flowing in a horizontal circular straight tube with a bell-mouth inlet have been determined experimentally over a flow Reynolds number range of 1,500 to 27,000. A wall-boundary heating condition of uniform heat flux was imposed. The variation of local heat transfer coefficient with length in the transition and turbulent flow regimes is very unusual. For the bell-mouth inlet, the boundary layer along the tube wall is at first laminar and then changes through a transition region to the turbulent condition causing a dip in the Nu-x/D curve. The length of the dip in the transition region is much longer than that in the turbulent region. For the experiments the length of the dip in the transition region varied from x/D = 100 to 175 in comparison to an x/D < 25 for the turbulent region. The presence of the dip in the transition region causes a significant influence on both the local and the average heat transfer coefficients. This is particularly important for heat transfer calculations in short tubes with a bell-mouth inlet.

  6. Optimization of a one-step heat-inducible in vivo mini DNA vector production system.

    PubMed

    Nafissi, Nafiseh; Sum, Chi Hong; Wettig, Shawn; Slavcev, Roderick A

    2014-01-01

    While safer than their viral counterparts, conventional circular covalently closed (CCC) plasmid DNA vectors offer a limited safety profile. They often result in the transfer of unwanted prokaryotic sequences, antibiotic resistance genes, and bacterial origins of replication that may lead to unwanted immunostimulatory responses. Furthermore, such vectors may impart the potential for chromosomal integration, thus potentiating oncogenesis. Linear covalently closed (LCC), bacterial sequence free DNA vectors have shown promising clinical improvements in vitro and in vivo. However, the generation of such minivectors has been limited by in vitro enzymatic reactions hindering their downstream application in clinical trials. We previously characterized an in vivo temperature-inducible expression system, governed by the phage ? pL promoter and regulated by the thermolabile ? CI[Ts]857 repressor to produce recombinant protelomerase enzymes in E. coli. In this expression system, induction of recombinant protelomerase was achieved by increasing culture temperature above the 37C threshold temperature. Overexpression of protelomerase led to enzymatic reactions, acting on genetically engineered multi-target sites called "Super Sequences" that serve to convert conventional CCC plasmid DNA into LCC DNA minivectors. Temperature up-shift, however, can result in intracellular stress responses and may alter plasmid replication rates; both of which may be detrimental to LCC minivector production. We sought to optimize our one-step in vivo DNA minivector production system under various induction schedules in combination with genetic modifications influencing plasmid replication, processing rates, and cellular heat stress responses. We assessed different culture growth techniques, growth media compositions, heat induction scheduling and temperature, induction duration, post-induction temperature, and E. coli genetic background to improve the productivity and scalability of our system, achieving an overall LCC DNA minivector production efficiency of ? 90%.We optimized a robust technology conferring rapid, scalable, one-step in vivo production of LCC DNA minivectors with potential application to gene transfer-mediated therapeutics. PMID:24586704

  7. Production of Heat Resistant Composite based on Siloxane Elastomer and Multiwall Carbon Nanotubes

    NASA Astrophysics Data System (ADS)

    Bessonov, I. V.; Karelina, N. V.; Kopitsyna, M. N.; Morozov, A. S.; Reznik, S. V.; Skidchenko, V. Yu.

    2016-02-01

    Development of a new generation of composite with unique thermal properties is an important task in the fields of science and technology where material is operated at high temperatures and exposure to a short-wave radiation. Recent studies show that carbon nanomaterials (fullerenes and carbon nanotubes) could improve the thermal, radiation and thermal-oxidative stability of the polymer matrix. In this article the development of a new heat resistant composite based on elastomer and carbon nanotubes (CNT) was performed and physicochemical properties of final product were evaluated.

  8. Modelling Hydraulic and Thermal Responses in a Benchmark for Deep Geothermal Heat Production

    NASA Astrophysics Data System (ADS)

    Holzbecher, E.; Oberdorfer, P.

    2012-04-01

    Geothermal heat production from deep reservoirs (5000-7000 m) is currently examined within the collaborative research program "Geothermal Energy and High-Performance Drilling" (gebo), funded by the Ministry of Science and Culture of Lower Saxony (Germany) and Baker Hughes. The projects concern exploration and characterization of geothermal reservoirs as well as production. They are gathered in the four major topic fields: geosystem, drilling, materials, technical system. We present modelling of a benchmark set-up concerning the geothermal production itself. The benchmark model "Horstberg" was originally created by J. Löhken and is based on geological data, concerning the Horstberg site in Lower Saxony. The model region consists of a cube with a side length of 5 km, in which 13 geological layers are included. A fault zone splits the region into two parts with shifted layering. A well is implemented, reaching from the top to an optional depth crossing all layers including the fault zone. The original geological model was rebuilt and improved in COMSOL Multiphysics Version 4.2a. The heterogeneous and detailed configuration makes the model interesting for benchmarking hydrogeological and geothermal applications. It is possible to inject and pump at any level in the well and to study the hydraulic and thermal responses of the system. The hydraulic and thermal parameters can be varied, and groundwater flow can be introduced. Moreover, it is also possible to examine structural mechanical responses to changes in the stress field (which is not further examined here). The main purpose of the presented study is to examine the dynamical flow characteristics of a hydraulic high conductive zone (Detfurth) in connection to a high conductive fault. One example is the fluid injection in the Detfurth zone and production in the fault. The high conductive domains can provide a hydraulic connection between the well screens and the initiated flow circuit could be used for geothermal heat production. The dependence of the flow regime and heat production on parameters like pumping rate, aquifer velocity and well position is demonstrated. Acknowledgements: gebo

  9. Global effects of local food-production crises: a virtual water perspective.

    PubMed

    Tamea, Stefania; Laio, Francesco; Ridolfi, Luca

    2016-01-01

    By importing food and agricultural goods, countries cope with the heterogeneous global water distribution and often rely on water resources available abroad. The virtual displacement of the water used to produce such goods (known as virtual water) connects together, in a global water system, all countries participating to the international trade network. Local food-production crises, having social, economic or environmental origin, propagate in this network, modifying the virtual water trade and perturbing local and global food availability, quantified in terms of virtual water. We analyze here the possible effects of local crises by developing a new propagation model, parsimonious but grounded on data-based and statistically-verified assumptions, whose effectiveness is proved on the Argentinean crisis in 2008-09. The model serves as the basis to propose indicators of crisis impact and country vulnerability to external food-production crises, which highlight that countries with largest water resources have the highest impact on the international trade, and that not only water-scarce but also wealthy and globalized countries are among the most vulnerable to external crises. The temporal analysis reveals that global average vulnerability has increased over time and that stronger effects of crises are now found in countries with low food (and water) availability. PMID:26804492

  10. Global effects of local food-production crises: a virtual water perspective

    PubMed Central

    Tamea, Stefania; Laio, Francesco; Ridolfi, Luca

    2016-01-01

    By importing food and agricultural goods, countries cope with the heterogeneous global water distribution and often rely on water resources available abroad. The virtual displacement of the water used to produce such goods (known as virtual water) connects together, in a global water system, all countries participating to the international trade network. Local food-production crises, having social, economic or environmental origin, propagate in this network, modifying the virtual water trade and perturbing local and global food availability, quantified in terms of virtual water. We analyze here the possible effects of local crises by developing a new propagation model, parsimonious but grounded on data-based and statistically-verified assumptions, whose effectiveness is proved on the Argentinean crisis in 2008–09. The model serves as the basis to propose indicators of crisis impact and country vulnerability to external food-production crises, which highlight that countries with largest water resources have the highest impact on the international trade, and that not only water-scarce but also wealthy and globalized countries are among the most vulnerable to external crises. The temporal analysis reveals that global average vulnerability has increased over time and that stronger effects of crises are now found in countries with low food (and water) availability. PMID:26804492

  11. Global effects of local food-production crises: a virtual water perspective

    NASA Astrophysics Data System (ADS)

    Tamea, Stefania; Laio, Francesco; Ridolfi, Luca

    2016-01-01

    By importing food and agricultural goods, countries cope with the heterogeneous global water distribution and often rely on water resources available abroad. The virtual displacement of the water used to produce such goods (known as virtual water) connects together, in a global water system, all countries participating to the international trade network. Local food-production crises, having social, economic or environmental origin, propagate in this network, modifying the virtual water trade and perturbing local and global food availability, quantified in terms of virtual water. We analyze here the possible effects of local crises by developing a new propagation model, parsimonious but grounded on data-based and statistically-verified assumptions, whose effectiveness is proved on the Argentinean crisis in 2008–09. The model serves as the basis to propose indicators of crisis impact and country vulnerability to external food-production crises, which highlight that countries with largest water resources have the highest impact on the international trade, and that not only water-scarce but also wealthy and globalized countries are among the most vulnerable to external crises. The temporal analysis reveals that global average vulnerability has increased over time and that stronger effects of crises are now found in countries with low food (and water) availability.

  12. 'Maximum' entropy production in self-organized plasma boundary layer: A thermodynamic discussion about turbulent heat transport

    SciTech Connect

    Yoshida, Z.; Mahajan, S. M.

    2008-03-15

    A thermodynamic model of a plasma boundary layer, characterized by enhanced temperature contrasts and ''maximum entropy production,'' is proposed. The system shows bifurcation if the heat flux entering through the inner boundary exceeds a critical value. The state with a larger temperature contrast (larger entropy production) sustains a self-organized flow. An inverse cascade of energy is proposed as the underlying physical mechanism for the realization of such a heat engine.

  13. Numerical study of the accumulation dynamics of oil shale thermal decomposition products in the vicinity of a heating element

    NASA Astrophysics Data System (ADS)

    Knyazeva, A. G.; Maslov, A. L.

    2015-10-01

    This study proposes the model of thermal decomposition of oil shale heated by electrodes. Differences in thermal physical properties of phases (solid core and gas, reagents and decomposition products), flow of generated gases in pores, and thermal effects of decomposition reactions are taken into account. The consideration of concentration expansion phenomenon is one of the features of the described model. The solution was carried out numerically. The concentration change of intermediate and final reaction products were studied for various heating conditions.

  14. Aspen Plus® and economic modeling of equine waste utilization for localized hot water heating via fast pyrolysis.

    PubMed

    Hammer, Nicole L; Boateng, Akwasi A; Mullen, Charles A; Wheeler, M Clayton

    2013-10-15

    Aspen Plus(®) based simulation models have been developed to design a pyrolysis process for on-site production and utilization of pyrolysis oil from equine waste at the Equine Rehabilitation Center at Morrisville State College (MSC). The results indicate that utilization of all the available waste from the site's 41 horses requires a 6 oven dry metric ton per day (ODMTPD) pyrolysis system but it will require a 15 ODMTPD system for waste generated by an additional 150 horses at the expanded area including the College and its vicinity. For this a dual fluidized bed combustion reduction integrated pyrolysis system (CRIPS) developed at USDA's Agricultural Research Service (ARS) was identified as the technology of choice for pyrolysis oil production. The Aspen Plus(®) model was further used to consider the combustion of the produced pyrolysis oil (bio-oil) in the existing boilers that generate hot water for space heating at the Equine Center. The model results show the potential for both the equine facility and the College to displace diesel fuel (fossil) with renewable pyrolysis oil and alleviate a costly waste disposal problem. We predict that all the heat required to operate the pyrolyzer could be supplied by non-condensable gas and about 40% of the biochar co-produced with bio-oil. Techno-economic Analysis shows neither design is economical at current market conditions; however the 15 ODMTPD CRIPS design would break even when diesel prices reach $11.40/gal. This can be further improved to $7.50/gal if the design capacity is maintained at 6 ODMTPD but operated at 4950 h per annum. PMID:23845952

  15. Possibilities of reducing the weight and cost of production of heat exchanger plates

    SciTech Connect

    Pertsev, L.P.; Dolinskii, V.D.; Iovenko, S.B.; Khodorets, A.N.; Posmyk, A.T.; Smyslina, O.V.; Yurchenko, V.Y.

    1984-03-01

    This article demonstrates how the method of production of sheets from shaped rolled sheet makes it possible to significantly reduce their metal consumption and cost. The sheets of heat exchange apparatuses are heavy structures compressing a block of plates with the help of tie bolts. There are two designs of sheets, unribbed and ribbed. The pieces for sheets are made by casting, forging, from rolled sheet, or by welding. A comparative strength evaluation is made of clamping sheets for semiprefabricated heat exchangers with a plate surface of 0.5 m/sup 2/. Sheets made by casting and from rolled sheet were calculated. A detailed analysis was made of five sheets of ribbed heat exchangers with a plate surface of 0.6 m/sup 2/ consisting of an unribbed sheet of rolled sheet, a welded sheet with longitudinal and transverse ribbing, a rolled sheet (shaded sheet) with transverse ribbing, and a rolled and welded sheet (shaped sheet) with longitudinal and transverse ribbing. It is determined that the ribbed designs of sheet require less metal than the unribbed.

  16. Control of Byssochlamys and Related Heat-resistant Fungi in Grape Products

    PubMed Central

    King, A. Douglas; Michener, H. David; Ito, Keith A.

    1969-01-01

    Heat-resistant strains of Byssochlamys fulva, B. nivea, and other heat-resistant fungi were isolated from vineyard soil, grapes, grape-processing lines, and waste pomace. They are known to remain in grape juice occasionally and to grow in grape juice products. Ascospores of these fungi have a D value (decimal reduction time) of about 10 min at 190 F (88 C), but in the presence of 90 μliters of SO2 per liter (normally added to the juice) the D value was cut in half. Filtration through a commercial diatomaceous filter aid (also a common processing step) entrapped all but about 0.001% of experimentally added spores. Thus, heat in the presence of SO2 and filtration together can reduce the population of these spores by several orders of magnitude. Growth was also prevented by benzoate or sorbate in low concentrations. Oxygen must be reduced to extremely low levels before lack of oxygen limits growth. Images PMID:16349856

  17. Effects of pulse-modulated microwave radiation and conventional heating on sperm production

    SciTech Connect

    Lebovitz, R.M.; Johnson, L.; Samson, W.K.

    1987-01-01

    The effects on testicular function of pulse-modulated microwave radiation (PM MWR, 1.3 GHz) and of conventional heating were studied in the rat. Anesthetized adult males (Sprague-Dawley, 400-500 g) were treated then killed at specific intervals with respect to the 13-day cycle of the seminiferous epithelium. PM MWR at 7.7 mW/g (90 min) yielded a modest decline in daily sperm production (DSP) that derived primarily from effects on primary spermatocytes. PM MWR at 4.2 mW/g was ineffective. The mean intratesticular temperature during the former reached 40 degrees C and did not exceed 38 degrees C during the latter. MWR considerably in excess of 7.7 mW/g yielded decrements in virtually all germ cell types, with primary spermatocytes again being most markedly affected. Using conventional heating, intratesticular temperatures in excess of 39 degrees C for 60 min were required for significant decrements in DSP. Levels of circulating follicle-stimulating hormone and of leutinizing hormone were resistant to either treatment. We conclude that the damage threshold and the differential sensitivity of immature germ cells to PM MWR can be adequately explained by the consequent macroscopic heating.

  18. Many-Body Localization Implies that Eigenvectors are Matrix-Product States.

    PubMed

    Friesdorf, M; Werner, A H; Brown, W; Scholz, V B; Eisert, J

    2015-05-01

    The phenomenon of many-body localization has received a lot of attention recently, both for its implications in condensed-matter physics of allowing systems to be an insulator even at nonzero temperature as well as in the context of the foundations of quantum statistical mechanics, providing examples of systems showing the absence of thermalization following out-of-equilibrium dynamics. In this work, we establish a novel link between dynamical properties--a vanishing group velocity and the absence of transport--with entanglement properties of individual eigenvectors. For systems with a generic spectrum, we prove that strong dynamical localization implies that all of its many-body eigenvectors have clustering correlations. The same is true for parts of the spectrum, thus allowing for the existence of a mobility edge above which transport is possible. In one dimension these results directly imply an entanglement area law; hence, the eigenvectors can be efficiently approximated by matrix-product states. PMID:25978216

  19. [Knowledge co-production and local transfer to reduce inequalities of access to breast cancer screening].

    PubMed

    Viot, Marianne; Vaillant, Zo; Harel, Lucile; Rican, Stphane; Dauchez, Mlanie Boulland; Baron, Marie; Ndiaye, El Hadji Malik Lam; Delpech, Eva; Brchenade, Sylvie; El Ghozi, Laurent; Salem, Grard

    2015-01-01

    This paper describes a knowledge transfer experiment that has been conducted since September 2012 in Argenteuil (Val d'Oise, France). This experiment is part of an interventional research project called DeCL/C: "Knowledge translation on social and spatial inequalities: a tool to raise local awareness and mobilization to lessen cancer screening participation rate disparities': The project is carried out by health geographers from Paris Ouest University (UPO) and the National Association of Cities for Public Health (Elus, Sante Publique et Territoires, ESPT). It encompasses two main components: intervention designed to implement a knowledge co-production and transfer process among researchers, stakeholders and decision makers at various levels. This knowledge concerns social and spatial determinants of inequalities of access to breast cancer screening programmes in cities. The research is multidisciplinary (geography, sociology, political science, epistemology) and is designed to measure the impact of this knowledge co-production and transfer in terms of actions in the targeted cities (six cities in the Paris region) as well as the reduction of inequalities of access to breast cancer screening programmes. This article, based on knowledge transfer literature and an empirical experiment in Argenteuil, describes the ongoing knowledge transfer process. It also highlights Argenteuil stakeholders' and decision makers' interest in action and research. The analysis of the knowledge co-production, sharing and ownership process by local actors a e both "strategic" and "profound': PMID:26414133

  20. The role of arterial oxygen tension in the respiratory response to localized heating of the hypothalamus and to hyperthermia

    PubMed Central

    Findlay, J. D.; Whittow, G. C.

    1966-01-01

    1. Rectal temperatures, respiratory rates, arterial blood gas tensions, arterial pH and the percentage of red cells in arterial blood have been measured in the unanaesthetized ox in a cool environment (15/12° C, dry bulb/wet bulb [DB/WB]), in a hot, dry environment (40/21° C, DB/WB), during hyperthermia, during infra-red irradiation, and during localized heating of the anterior hypothalamus. In some experiments the gas tensions and pH of mixed venous blood, and the percentage saturation of the arterial blood with oxygen, were also measured. 2. In the cool environment at a mean rectal temperature (Tr) of 38·8° C and a respiratory rate (f) of 28/min the mean values obtained from six animals were: arterial oxygen tension (Pa, O2), 93 mm Hg; arterial carbon dioxide tension (Pa, CO2) 42 mm Hg; arterial pH 7·49; arterial oxygen saturation (Sa, O2) 94%; arterial oxygen capacity (Capa, O2) 13·6 vol.%; arterial packed cell volume (P.C.V.) 29%. 3. Exposure to the hot, dry environment resulted in a small increase in the rectal temperature and thermal polypnoea, but there were no statistically significant changes in the blood gas tensions. 4. During hyperthermia statistically significant increases occurred in rectal temperature, respiratory rate, Pa, O2, pH and arterial haematocrit, while the Pa, CO2 decreased. The venous oxygen tension (Pv̄, O2) decreased also, and the tentative conclusion was made that although the oxygenation of arterial blood remained unimpaired during hyperthermia, tissue hypoxia may supervene. At very high levels of deep body temperature, some evidence for a secondary decrease in Pa, O2 was obtained. 5. Localized heating of the anterior hypothalamus caused an increase in respiratory rate and in Pa, O2. The Pv̄, O2 increased also. These changes were considered to be due to increased cardiac output and diversion of blood to the skin. 6. During infra-red irradiation of three animals at an environmental temperature of 40/21° C, the respiratory rate increased, but the Pa, O2 decreased. PMID:5972112