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1

The thermal performance of heat pipes with localized heat input  

NASA Technical Reports Server (NTRS)

The performance of heat pipes with localized heat input including the effects of axial and circumferential heat conduction under high and low working temperatures is investigated. The numerical results show that when heat pipes are spot heated, the peak temperature of the wall is greatly reduced and the surface can be protected from being burned out by the high heat flux. The boiling limitation becomes the most important limitation for this type of heat pipe. Numerical results for block heating a heat pipe with low working temperatures indicate a good agreement with existing experimental data. It is also shown that most of the input heat passes through the wall beneath the heated block.

Cao, Yiding; Faghri, Amir; Mahefkey, E. T.

1989-01-01

2

Implantable Apparatus for Localized Heating of Tissue.  

National Technical Information Service (NTIS)

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 ...

J. D. Doss

1985-01-01

3

MEMS post-packaging by localized heating and bonding  

Microsoft Academic Search

This work addresses important post-packaging issues for microsystems and recommends specific research directions by localized heating and bonding. Micropackaging has become a major subject for both scientific research and industrial applications in the emerging field of microelectromechanical systems (MEMS). Establishing a versatile post-packaging process not only advances the field but also speeds up the product commercialization cycle. A review of

L. Lin

2000-01-01

4

Compact Directional Microwave Antenna for Localized Heating  

NASA Technical Reports Server (NTRS)

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.

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

2008-01-01

5

Implantable apparatus for localized heating of tissue  

DOEpatents

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.

Doss, J.D.

1985-05-20

6

Implantable apparatus for localized heating of tissue  

DOEpatents

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.

Doss, James D. (Los Alamos, NM)

1987-01-01

7

Localization of small heat shock proteins to the higher plant endomembrane system. [Low-molecular-weight heat shock proteins  

SciTech Connect

Most eukaryotic cells respond to high temperature and other stresses with the production of heat shock proteins, which aid in cell survival. There are four major classes of heat shock proteins HSP90, HSP70, HSP60 and low-molecular weight HSP. The data from this research indicate that members of the low-molecular weight heat shock proteins are most likely resident endoplasmic reticulum (ER) proteins and may be similar in function to related low-molecular weight heat shock proteins in the cytoplasm. The low-molecular weight heat shock proteins, the HSP90 and the HSP70 all appear to localize to the endoplasmic reticulum. Since the ER-localized low-molecular weight heat shock proteins are physically separated from their counterparts in other cell compartments, investigations of the ER-localized heat shock proteins provides a simplified model system for determining the functions of low-molecular weight heat shock proteins in eukaryotes.

Helm, K.W.; Vierling, E. (Univ. of Arizona, Tucson (United States)); LaFayette, P.R.; Nagao, R.T.; Key, J.L. (Univ. of Georgia, Athens (United States))

1993-01-01

8

Local heat transfer in the intertube space of a heat exchanger with spiral tubes  

NASA Astrophysics Data System (ADS)

The article explains the methods and presents the results of the experimental investigation of local heat transfer in bundles of spiral tubes with heat supply to the heat carrier that is nonuniform over the cross section.

Dzyubenko, B. V.; Sakalauskas, A. V.; Vilemas, Yu. V.; Ashmantas, L. A.

1981-08-01

9

Interface Shape Control Using Localized Heating during Bridgman Growth  

NASA Technical Reports Server (NTRS)

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.

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

2008-01-01

10

Effect of Local Heating and Arterial Occlusion on Sweat Electrolyte Content.  

National Technical Information Service (NTIS)

Three different procedures (general body thermal stress, local heating, and arterial occlusion) were utilized to alter the rate of sweat production while corresponding changes in the concentration and rate of electrolyte excretion were examined. The volar...

M. Banerjee R. S. Elizondo R. W. Bullard

1971-01-01

11

Localized heat induced urticaria: report of a case.  

PubMed

Localized heat induced urticaria is a rare clinical entity. Other physical urticarial subtypes include cholinergic, solar, cold, aquagenic, vibratory, and dermatographic. It is characterized by a well-demarcated urticarial lesion provoked by heat in direct contact with the skin. We describe a case of localized heat-induced urticaria in a 49-year-old woman after a heat-challenge test to her forearm. PMID:14964751

Darling, Matthew; Lambiase, Matthew C; Hodson, Darryl S

2004-01-01

12

Interface Shape Control using Localized Heating during Bridgman Growth  

NASA Technical Reports Server (NTRS)

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 ofthe interface. A convex interface shape was most readily achieved with ampoules of lower thermal conductivity. The conditions under which convection in the melt must be considered were determined.

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

2008-01-01

13

Boiling local heat transfer enhancement in minichannels using nanofluids  

PubMed Central

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.

2013-01-01

14

Boiling local heat transfer enhancement in minichannels using nanofluids.  

PubMed

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

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

2013-01-01

15

Heat Production as a Tool in Geothermal Exploration  

NASA Astrophysics Data System (ADS)

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.

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

2012-12-01

16

Local effects of longitudinal heat conduction in plate heat exchangers  

Microsoft Academic Search

In a plate heat exchanger, heat transfer from the hot to the cold fluid is a multi-dimensional conjugate problem, in which longitudinal heat conduction (LHC) along the dividing walls often plays some role and can not be neglected. Large-scale, or end-to-end, LHC is always detrimental to the exchanger’s effectiveness. On the contrary, if significant non-uniformities exist in the distribution of

Michele Ciofalo

2007-01-01

17

Heat production due to intracellular killing activity.  

PubMed

Using Saccharomyces ceravisiae, Candida albicans and Stapylococcus aureus, heat production during phagocytosis was measured in U937 cells which are capable of differentiating to monocytic phagocytes. No increase in heat production of non-differentiated U937 was observed since they were not phagocytic cells. However after differentiation to monocytic phagocytes by lymphokine, U937 cells produced a remarkable amount of heat during phagocytosis. Although Ehrlich ascites tumor cells sensitized with antibody were capable of engulfing S. aureus, no increase in heat nor in superoxide anion production during phagocytosis was detected. It was also found that no heat increase occurred in neutrophils from a patient with chronic granulomatous disease (CGD). It can thus be concluded that the heat production during phagocytosis is due to the intercellular killing process of phagocytic cells. PMID:2131646

Hayatsu, H; Masuda, S; Miyamae, T; Yamamura, M

1990-09-01

18

Heat production in steady states and oscillations  

NASA Astrophysics Data System (ADS)

Measurements were made of the rate of heat production in three oscillatory systems: benzaldehyde oxidation, the Briggs-Rauscher reaction, and the Belousov-Zhabotinsky reaction. In cases where a stable steady state coexists with a limit cycle oscillation or where the steady state undergoes a hard loss of stability to oscillations, the heat production in the oscillatory state was quite different from that of the steady state, varying from 50 percent less to 210 percent greater. Bifurcations to oscillations involving a soft loss of stability showed no discontinuity in the heat production, as expected. Consideration of the thermodynamics of these reactions indicates that the contribution to the rate of entropy production due to enthalpy changes dominates that due to differences in the entropies of the products and reactants. In the benzaldehyde oxidation, the changes in heat production are due to a change in the average rate of the reaction, and not due to a change in the distribution of products.

Roelofs, M. G.

1988-05-01

19

Measurement of local high-level, transient surface heat flux  

NASA Technical Reports Server (NTRS)

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.

Liebert, Curt H.

1988-01-01

20

Solar steam generation by heat localization.  

PubMed

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. PMID:25043613

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

2014-01-01

21

Local cloning of two product states  

NASA Astrophysics Data System (ADS)

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.

Ji, Zhengfeng; Feng, Yuan; Ying, Mingsheng

2005-09-01

22

Maximum Skin Hyperaemia Induced by Local Heating: Possible Mechanisms  

Microsoft Academic Search

Background: Maximum skin hyperaemia (MH) induced by heating skin to ?42°C is impaired in individuals at risk of diabetes and cardiovascular disease. Interpretation of these findings is hampered by the lack of clarity of the mechanisms involved in the attainment of MH. Methods: MH was achieved by local heating of skin to 42–43°C for 30 min, and assessed by laser

Kim M. Gooding; Michael M. Hannemann; John E. Tooke; Geraldine F. Clough; Angela C. Shore

2006-01-01

23

SOME CHARACTERISTICS OF HEAT PRODUCTION USING THE \\  

Microsoft Academic Search

Additional evidence is presented to show that heat production resulting from the Pons-Fleis- chmann Effect has a positive temperature coefficient, has a critical onset current density, and originates at the palladium cathode.

Edmund Storms

24

Local heating-induced plastic deformation in resistive switching devices  

Microsoft Academic Search

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

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

2011-01-01

25

Convection calibration method for local heat flux gages  

Microsoft Academic Search

An apparatus for calibrating local heat flux gages in convective air flows is described. Heat transfer from a ''hot'' gage to a ''cold'' fluid was measured using a guarded hot-plate technique. The system was used to calibrate Gardon-type circular foil heat flux gates of 1\\/8 in. and 1\\/16 in. outer diameters. The reslts indicate that the calibration curves are nonlinear,

G. J. Borell; T. E. Diller

1987-01-01

26

Experimental investigation of local heat transfer characteristics by impingement cooling  

NASA Astrophysics Data System (ADS)

The simulation of the local heat transfer characteristics of the leading edge region of a turbine blade by impingement cooling of a concave surface with a row of circular air jets has been investigated experimentally. The effects of Reynolds number, the dimensionless distance between the jet and the target, and the compound geometrical configurations both of the impingement tube and target on the local heat transfer coefficients are discussed. The special distributions of local heat transfer coefficients are also analyzed. It is found from a large amount of experiments that the heat transfer coefficient distribution is not a simple Gauss function. The Gauss function fits the experimental data satisfactorily only at the stagnation region, while the local heat transfer coefficients in the jet region at the wall can be expressed in exponent functions. A set of empirical formulas which describe the distribution of the local heat transfer coefficients by impingement cooling have been obtained from the experimental data by means of least square approach.

Ren, Linghua; Zheng, Jirui

1987-01-01

27

Photothermal approach to local heating imaging: application to laser degradation  

NASA Astrophysics Data System (ADS)

We use various probes to measure local temperature induced by internal or external heating of active or passive devices: Mirage detection can reveal heating of few ppb of the input power, whereas photothermal microscopy provides sub-micron spatial resolution. Temperature distribution is measured through periodic deflection or reflectivity mapping at frequencies high enough to confine heating near the source. Scanning InGaAsP/InP lasers facets, shows the weak influence of nonradiative recombination, in agreement with the high output power of these lasers before degradation. On strained-layer InGaAs quantum well lasers we obtained a drastic temperature rise, that we explain through simple model based on line heating for the laser cavity and point heating located at the facet. On a damaged laser the result, demonstrate clearly the existence of heating zones far from the facet along the laser cavity.

Cherrak, R.; Loriette, Vincent; Forget, Benoit; Roger, Jean P.; Fournier, D.; Boccara, A. Claude

1998-04-01

28

Open cycle heat pump development for local resource use. Phase 2: District heating case study analysis  

NASA Astrophysics Data System (ADS)

District heating (DH) systems provide thermal energy to their customers in the form of hot water or steam. These systems can use one or more types of heat sources to meet the thermal load, including boilers, cogeneration systems, or low-grade heat sources in conjunction with a heat pump. Most large-scale heat pumps operate using the closed-cycle concept and usually use a chlorinated fluorocarbon (CFC) as the working fluid. An alternative to this approach is the quasi open-cycle heat pump, which was first studied in a Phase 1 report entitled, Open-Cycle Heat Pump Development for Local Resource Use, DOE/CE/26563-5. The quasi open-cycle (QOC) heat pump actually uses the district heating transport medium as its working fluid. This document is the Final Report prepared as a part of Task 6 of Open-Cycle Heat Pump Development for Local Resource Use, Phase 2 District Heating Case Study Analysis. The objective of this study contract was to assess the application of the QOC heat pump in an actual case study.

Patch, K. D.; Dibella, F. A.; Glick, J. F.; Becker, F. E.

1990-04-01

29

Initiating magnetization switching in computational Fe nanopillars via local heating  

NASA Astrophysics Data System (ADS)

The use of high-coercivity materials in recording media assists in extending the areal information density by allowing smaller, more closely spaced bits. To achieve densities greater than one terabit per square inch, however, the necessary coercivity of the particles challenges the maximum applied field that can be attained by the write head. One proposed technique to overcome this dilemma is heat-assisted magnetization reversal (HAMR), in which a locally applied heat pulse lowers the coercivity, allowing the applied field to initiate switching. To model this, we employ micromagnetic simulations of iron nanopillars with thermal fluctuations that depend spatially and temporally on a solution of the heat equation corresponding to an initial heat pulse applied to the end of the pillar. For the case of an applied magnetic field parallel to the easy axis, the magnetization-switching behavior is explored as a function of total heat input and applied-field magnitude.

Thompson, Sam; Brown, Greg; Novotny, Mark; Rikvold, Per

2009-03-01

30

Local heat transfer in a rotating serpentine flow passage  

SciTech Connect

An experimental study is performed on the internal cooling of a rotating serpentine flow passage of square cross section with throughflow. The test section is not proceeded by a hydrodynamic calming region, i.e., a leading arm, and is rotated at low Rossby numbers. The local heat transfer coefficients along the flow passage, including the leading wall, trailing wall, and sidewalls, are determined together with the circumferentially averaged values. The Reynolds, Rossby, and rotating Rayleigh numbers are varied to determine their effects on heat transfer performance. It is disclosed that heat transfer augmentation is significant at all sharp turns due to the presence of strong secondary flow. The rotational effect is very obvious and complicated in the local heat transfer performance but it is very minor on the average heat transfer performance. The throughflow rate plays an important role on the heat transfer performance. The results may serve as a baseline for comparison with the results from a model with a leading arm to determine the effects of a hydro-dynamic calming section on the heat transfer performance of a rotating serpentine flow passage.

Wenjei Yang; Nengli Zhang; Chiou, J. (Univ. of Michigan, Ann Arbor (United States))

1992-05-01

31

Incremental Sheet Forming with Local Heating for Lightweight Hard-To Material  

NASA Astrophysics Data System (ADS)

A new incremental sheet forming technology with local heating is proposed to form lightweight hard-to-form sheet metals such as aluminum-magnesium alloy (JIS A5083) sheet or magnesium alloy (JIS AZ31) sheet. The newly designed forming tool has a built-in heater to heat the sheet metal locally and increase the material ductility around the tool-contact point. Incremental forming experiments of A5083 and AZ31 sheets are carried out at several tool-heater temperatures ranging from room temperature to 873K using the new forming method. The experimental results show that the formability of A5083 and AZ31 sheets increases remarkably with increasing local-heating temperature. In addition, springback of formed products decreases with increasing local-heating temperature. The developed incremental sheet forming method with local heating has great advantages in not only formability but also shape fixability. It is an effective forming method for lightweight hard-to-form sheet metal for small scale productions.

Hino, R.; Yoshida, F.; Nagaishi, N.; Naka, T.

32

Local heat transfer in a rotating serpentine flow passage  

Microsoft Academic Search

An experimental study is performed on the internal cooling of a rotating serpentine flow passage of square cross section with throughflow. The test section is not preceded by a hydrodynamic calming region, i.e., a leading arm, and is rotated at low Rossby numbers. The local heat transfer coefficients along the flow passage, including the leading wall, trailing wall, and sidewalls,

Wen-Jei Yang; Nengli Zhang; Jeff Chiou

1992-01-01

33

Local heating, but not indirect whole body heating, increases human skeletal muscle blood flow  

PubMed Central

For decades it was believed that direct and indirect heating (the latter of which elevates blood and core temperatures without directly heating the area being evaluated) increases skin but not skeletal muscle blood flow. Recent results, however, suggest that passive heating of the leg may increase muscle blood flow. Using the technique of positron-emission tomography, the present study tested the hypothesis that both direct and indirect heating increases muscle blood flow. Calf muscle and skin blood flows were evaluated from eight subjects during normothermic baseline, during local heating of the right calf [only the right calf was exposed to the heating source (water-perfused suit)], and during indirect whole body heat stress in which the left calf was not exposed to the heating source. Local heating increased intramuscular temperature of the right calf from 33.4 ± 1.0°C to 37.4 ± 0.8°C, without changing intestinal temperature. This stimulus increased muscle blood flow from 1.4 ± 0.5 to 2.3 ± 1.2 ml·100 g?1·min?1 (P < 0.05), whereas skin blood flow under the heating source increased from 0.7 ± 0.3 to 5.5 ± 1.5 ml·100 g?1·min?1 (P < 0.01). While whole body heat stress increased intestinal temperature by ?1°C, muscle blood flow in the calf that was not directly exposed to the water-perfused suit (i.e., indirect heating) did not increase during the whole body heat stress (normothermia: 1.6 ± 0.5 ml·100 g?1·min?1; heat stress: 1.7 ± 0.3 ml·100 g?1·min?1; P = 0.87). Whole body heating, however, reflexively increased calf skin blood flow (to 4.0 ± 1.5 ml·100 g?1·min?1) in the area not exposed to the water-perfused suit. These data show that local, but not indirect, heating increases calf skeletal muscle blood flow in humans. These results have important implications toward the reconsideration of previously accepted blood flow distribution during whole body heat stress.

Heinonen, Ilkka; Brothers, R. Matthew; Kemppainen, Jukka; Knuuti, Juhani; Kalliokoski, Kari K.

2011-01-01

34

Role of blood as heat source or sink in human limbs during local cooling and heating.  

PubMed

The objective of the present study was to investigate the relative contribution of the convective heat transfer in the forearm and hand to 1) the total heat loss during partial immersion in cold water [water temperature (Tw) = 20 degrees C] and 2) the heat gained during partial immersion in warm water (Tw = 38 degrees C). The heat fluxes from the skin of the forearm and finger were continuously monitored during the 3.5-h immersion of the upper limb (forearm and hand) with 23 recalibrated heat flux transducers. The last 30 min of the partial immersion were conducted with an arterial occlusion of the forearm. The heat flux values decreased during the occlusion period at Tw = 20 degrees C and increased at Tw = 38 degrees C for all sites, plateauing only for the finger to the value of the tissue metabolic rate (124.8 +/- 29.0 W/m3 at Tw = 20 degrees C and 287.7 +/- 41.8 W/m3 at Tw = 38 degrees C). The present study shows that, at thermal steady state during partial immersion in water at 20 degrees C, the convective heat transfer between the blood and the forearm tissue is the major heat source of the tissue and accounts for 85% of the total heat loss to the environment. For the finger, however, the heat produced by the tissue metabolism and that liberated by the convective heat transfer are equivalent. At thermal steady state during partial immersion in water at 38 degrees C, the blood has the role of a heat sink, carrying away from the limb the heat gained from the environment and, to a lesser extent (25%), the metabolic and conductive heats. These results suggest that during local cold stress the convective heat transfer by the blood has a greater role than that suggested by previous studies for the forearm but a lesser role for the hand. PMID:8063672

Ducharme, M B; Tikuisis, P

1994-05-01

35

Determinants of heat production in newborn lambs  

NASA Astrophysics Data System (ADS)

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.

Eales, F. A.; Small, J.

1980-06-01

36

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

SciTech Connect

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.

O'Brien, James Edward; Sohal, Manohar Singh

2000-08-01

37

Local Heat Flux Measurements with Single Element Coaxial Injectors  

NASA Technical Reports Server (NTRS)

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.

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

2006-01-01

38

Local and Nonlocal Parallel Heat Transport in General Magnetic Fields  

NASA Astrophysics Data System (ADS)

Transport in magnetized plasmas is a topic of fundamental interest in controlled fusion, space plasmas, and astrophysics. Three issues make this problem particularly challenging: (i) The extreme anisotropy between the parallel (i.e., along the magnetic field), ?, and the perpendicular, ?, conductivities; (ii) Magnetic field lines chaos which may preclude the use of magnetic coordinates; and (iii) Nonlocal parallel transport in the limit of small collisionality. As a result of these challenges, standard finite-difference and finite-element numerical methods face significant limitations. Motivated by the strong anisotropy typically encountered in magnetized plasmas (?/? may be less than 10-10 in fusion plasmas) we consider heat transport in the extreme anisotropic regime, ?=0. To overcome the limitations of previous approaches, we present a novel Lagrangian Green's function method that bypasses the need to discretize and invert the transport operators on a grid.ootnotetextD. del-Castillo-Negrete and L. Chacon, Phys. Rev. Lett. 106 195004 (2011). The method allows the integration of the parallel transport equation without perpendicular pollution, preserving the positivity of the temperature field at all times. The method is applicable to local (i.e., diffusive) and non-local (e.g., free streaming) heat flux closures in integrable or chaotic magnetic fields. The method is applied to study: (i) Local and non-local parallel temperature mixing and flattening inside magnetic islands; (ii) Fractal structure of the Devil's staircase temperature profile in the previously inaccessible ?=0 regime in weakly chaotic fields; (iii) Transport in fully chaotic fields. For the last problem it is shown that, for local and non-local parallel closures, transport is incompatible with the quasilinear diffusion model. In particular, flux-gradient plots show clear evidence of non-diffusive, non-local effective radial transport.

Del-Castillo-Negrete, Diego

2011-11-01

39

Comparison of steady state and transient methods for measurement of local heat transfer in plate fin-tube heat exchangers using liquid crystal thermography with radiant heating  

Microsoft Academic Search

Optical methods for measuring local heat transfer coefficients using thermochromic liquid crystals are discussed. Two techniques using radiative steady state and transient heating have been used to measure local heat transfer on the fin of a plate fin-tube heat exchanger. It is estimated that the errors in the steady state technique should be no more than ±10% and the results

R. E. Critoph; M. K. Holland; M. Fisher

1999-01-01

40

Sex-related differences in local and whole-body heat loss responses: Physical or physiological?  

PubMed

The current thesis examined whether sex differences in local and whole-body heat loss are evident after accounting for confounding differences in physical characteristics and rate of metabolic heat production. Three experimental studies were performed: the first examined whole-body heat loss in males and females matched for body mass and surface area during exercise at a fixed rate of metabolic heat production; the second examined local and whole-body heat loss responses between sexes during exercise at increasing requirements for heat loss; the third examined sex-differences in local sweating and cutaneous vasodilation to given doses of pharmacological agonists, as well as during passive heating. The first study demonstrated that females exhibit a lower whole-body sudomotor thermosensitivity (553 ± 77 vs. 795 ± 85 W·°C(-1), p = 0.05) during exercise performed at a fixed rate of metabolic heat production. The second study showed that whole-body sudomotor thermosensitivity is similar between sexes at a requirement for heat loss of 250 W·m(-2) (496 ± 139 vs. 483 ± 185 W·m(-2)·°C(-1), p = 0.91) and 300 W·m(-2) (283 ± 70 vs. 211 ± 66 W·m(-2)·°C(-1), p = 0.17), only becoming greater in males at a requirement for heat loss of 350 W·m(-2) (197 ± 61 vs. 82 ± 27 W·m(-2)·°C(-1), p = 0.007). In the third study, a lower sweat rate to the highest concentration of acetylcholine (0.27 ± 0.08 vs. 0.48 ± 0.13 mg·min(-1)·cm(-2), p = 0.02) and methacholine (0.41 ± 0.09 vs. 0.57 ± 0.11 mg·min(-1)·cm(-2), p = 0.04) employed was evidenced in females, with no differences in cholinergic sensitivity. Taken together, the results of the current thesis show that sex itself can modulate sudomotor activity, specifically the thermosensitivity of the response, during both exercise and passive heat stress. Furthermore, the results of the third study point towards a peripheral modulation of the sweat gland as a mechanism responsible for the lower sudomotor thermosensitivity in females. PMID:24971681

Gagnon, Daniel

2014-07-01

41

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

NASA Astrophysics Data System (ADS)

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.

Grabenstein, V.; Kabelac, S.

2012-11-01

42

Local heat transfer on the plane porous surface of a curvilinear duct of rectangular cross section  

Microsoft Academic Search

Results of an experimental study of local heat transfer coefficients on the plane porous surface of a curvilinear contracting duct of rectangular cross section are reported. The experimental data are generalized to obtain an expression for the relative injection function and a similarity equation for local heat transfer. The local heat transfer equation includes the combined effect of injection, flow

A. A. Khalatov; A. N. Trufanov; A. S. Kovalenko

1987-01-01

43

Transient response to localized episodic heating in the tropics  

NASA Astrophysics Data System (ADS)

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.

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

1985-12-01

44

Strong contributions of local background climate to urban heat islands.  

PubMed

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. PMID:25008529

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

2014-07-10

45

Compressed air production with waste heat utilization in industry  

Microsoft Academic Search

The centralized power-heat coupling (PHC) technique using block heating power stations, is presented. Compressed air production in PHC technique with internal combustion engine drive achieves a high degree of primary energy utilization. Cost savings of 50% are reached compared to conventional production. The simultaneous utilization of compressed air and heat is especially interesting. A speed regulated drive via an internal

E. Nolting

1984-01-01

46

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

NASA Astrophysics Data System (ADS)

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-Büttiker 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.

Sääskilahti, K.; Oksanen, J.; Tulkki, J.

2013-07-01

47

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

PubMed

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-Büttiker 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

Sääskilahti, K; Oksanen, J; Tulkki, J

2013-07-01

48

Homogeneous Thermal Cloak with Constant Conductivity and Tunable Heat Localization  

NASA Astrophysics Data System (ADS)

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.

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

2013-04-01

49

Local thermodynamic equilibrium in rapidly heated high energy density plasmas  

NASA Astrophysics Data System (ADS)

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.

Aslanyan, V.; Tallents, G. J.

2014-06-01

50

Homogeneous Thermal Cloak with Constant Conductivity and Tunable Heat Localization  

PubMed Central

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.

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

2013-01-01

51

Heating value of biomass and biomass pyrolysis products  

Microsoft Academic Search

Studies conducted on the heating value of various types of biomass components and their pyrolysis products such as char, liquids and gases are presented. Heating values of chars are comparable with those of lignite and coke; heating values of liquids are comparable with those of oxygenated fuels such as methanol and ethanol, which are much lower than those of petroleum

K. Raveendran; Anuradda Ganesh

1996-01-01

52

Direct contact heat exchangers in geothermal power production  

Microsoft Academic Search

The direct contact cycle can be advantageously utilized in the production of power from liquid dominated geothermal resources. The heat from the geothermal resource is transferred to a selected working fluid by direct countercurrent contact in a vertical perforated trayed tower. The direct contactor is divided into three heat transfer zones where heat is extracted from the hot water by

I. Sheinbaum

1975-01-01

53

Local heating of human skin causes hyperemia without mediation by muscarinic cholinergic receptors or prostanoids.  

PubMed

Local changes in surface temperature have a powerful influence on the perfusion of human skin. Heating increases local skin blood flow, but the mechanisms and mediators of this response (thermal hyperemia response) are incompletely elucidated. In the present study, we examined the possible dependence of the thermal hyperemia response on stimulation of muscarinic cholinergic receptors and on production of vasodilator prostanoids. In 13 male healthy subjects aged 20-30 yr, a temperature-controlled chamber was positioned on the volar face of one forearm and used to raise surface temperature from 34 to 41 degrees C. The time course of the resulting thermal hyperemia response was recorded with a laser-Doppler imager. In one experiment, each of eight subjects received an intravenous bolus of the antimuscarinic agent glycopyrrolate (4 microg/kg) on one visit and saline on the other. The thermal hyperemia response was determined within the hour after the injections. Glycopyrrolate effectively inhibited the skin vasodilation induced by iontophoresis of acetylcholine but did not influence the thermal hyperemia response. In a second experiment, conducted in five other subjects, 1 g of the cyclooxygenase inhibitor aspirin administered orally totally abolished the vasodilation induced in the skin by anodal current but also failed to modify the thermal hyperemia response. The present study excludes the stimulation of muscarinic receptors and the production of vasodilator prostaglandins as essential and nonredundant mechanisms for the vasodilation induced by local heating in human forearm skin. PMID:15247159

Golay, Sandrine; Haeberli, Christian; Delachaux, Anne; Liaudet, Lucas; Kucera, Paul; Waeber, Bernard; Feihl, François

2004-11-01

54

Local heat transfer on the plane porous surface of a curvilinear duct of rectangular cross section  

NASA Astrophysics Data System (ADS)

Results of an experimental study of local heat transfer coefficients on the plane porous surface of a curvilinear contracting duct of rectangular cross section are reported. The experimental data are generalized to obtain an expression for the relative injection function and a similarity equation for local heat transfer. The local heat transfer equation includes the combined effect of injection, flow line curvature, transverse boundary layer flows, flow acceleration, and laminar transition.

Khalatov, A. A.; Trufanov, A. N.; Kovalenko, A. S.

55

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

SciTech Connect

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''.

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

2001-12-31

56

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

NASA Astrophysics Data System (ADS)

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.

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

2014-05-01

57

Heat-Pipe-Associated Localized Thermoelectric Power Generation System  

NASA Astrophysics Data System (ADS)

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.

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

58

Heat-Pipe-Associated Localized Thermoelectric Power Generation System  

NASA Astrophysics Data System (ADS)

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.

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

2013-11-01

59

Local Heat Transfer for the Evaporation of a Laminar Falling Liquid Film on a Cylinder: Experimental, Numerical, and Inverse Heat Conduction Analysis  

Microsoft Academic Search

This article presents the experimental, numerical, and inverse heat conduction (IHCP) analysis of the evaporation heat transfer of a falling liquid film on a horizontal cylinder. The two-dimensional IHCP is solved in order to determine the surface temperature, local heat flux, and local heat transfer coefficient for the sheet flow. The local surface temperature is used as the boundary condition

H. Louahlia-Gualous; L. El Omari

2006-01-01

60

Crustal composition and mantle heat flow: Implications from surface heat flow and radiogenic heat production in the Variscan Erzgebirge (Germany)  

Microsoft Academic Search

From an enlarged data set of temperature logs and thermal conductivity measurements, surface heat flow (qs) in the Erzgebirge was determined to range from 61 to 112 mWm-2. U-Th-K2O data show that the heat flow pattern is controlled to first order by the occurrence of high heat production Variscan granites within a metamorphic basement. Highest heat flow correlates with granite

Andrea Förster; Hans-Jürgen Förster

2000-01-01

61

Dissipation and entropy production in deterministic heat conduction of quasi-one-dimensional systems  

NASA Astrophysics Data System (ADS)

We explore the consequences of a deterministic microscopic thermostat-reservoir contact mechanism. With different temperature reservoirs at each end of a two-dimensional system, a heat current is produced and the system has an anomalous thermal conductivity. The microscopic form for the local heat flux vector is derived and both the kinetic and potential contributions are calculated. The total heat flux vector is shown to satisfy the continuity equation. The properties of this nonequilibrium steady state are studied as functions of system size and temperature gradient, identifying key scaling relations for the local fluid properties and separating bulk and boundary effects. The local entropy density calculated from the local equilibrium distribution is shown to be a very good approximation to the entropy density calculated directly from the velocity distribution even for systems that are far from equilibrium. The dissipation and kinetic entropy production and flux are compared quantitatively and the differing mechanisms discussed within the Bhatnagar-Gross-Krook approximation. For equal-temperature reservoirs the entropy production near the reservoir walls is shown to be proportional to the local phase space contraction calculated from the tangent space dynamics. However, for unequal temperatures, the connection between local entropy production and local phase space contraction is more complicated.

Morriss, Gary P.; Truant, Daniel P.

2013-06-01

62

Dissipation and entropy production in deterministic heat conduction of quasi-one-dimensional systems.  

PubMed

We explore the consequences of a deterministic microscopic thermostat-reservoir contact mechanism. With different temperature reservoirs at each end of a two-dimensional system, a heat current is produced and the system has an anomalous thermal conductivity. The microscopic form for the local heat flux vector is derived and both the kinetic and potential contributions are calculated. The total heat flux vector is shown to satisfy the continuity equation. The properties of this nonequilibrium steady state are studied as functions of system size and temperature gradient, identifying key scaling relations for the local fluid properties and separating bulk and boundary effects. The local entropy density calculated from the local equilibrium distribution is shown to be a very good approximation to the entropy density calculated directly from the velocity distribution even for systems that are far from equilibrium. The dissipation and kinetic entropy production and flux are compared quantitatively and the differing mechanisms discussed within the Bhatnagar-Gross-Krook approximation. For equal-temperature reservoirs the entropy production near the reservoir walls is shown to be proportional to the local phase space contraction calculated from the tangent space dynamics. However, for unequal temperatures, the connection between local entropy production and local phase space contraction is more complicated. PMID:23848664

Morriss, Gary P; Truant, Daniel P

2013-06-01

63

Local jet impingement boiling heat transfer with R113  

Microsoft Academic Search

An experimental study was performed to characterize the boiling heat transfer of impinging circular submerged jets on simulated microelectronic chips with a nominal area of 5 mm × 5 mm. The heat transfer modes included natural convection, partially developed nucleate boiling, fully developed nucleate boiling and critical heat flux. The study included the effects of jet parameters and fluid subcooling

D. W. Zhou; C. F. Ma

2004-01-01

64

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

NASA Astrophysics Data System (ADS)

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.

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

2011-07-01

65

Heat production as a quantitative parameter of phagocytosis.  

PubMed

Microcalorimetry was applied to measure phagocytosis by human peripheral blood neutrophils and monocytes. Heat production was 9.1 +/- 2.6 microW by 1 X 10(6) unstimulated neutrophils and increased to 28.4 +/- 3.2 microW in association with phagocytosis. The increase in heat production was directly proportional to the number of Saccharomyces cerevisiae particles phagocytosed as well as to the concentration of opsonizing serum. No heat increase was observed in the absence of phagocytosis. An increase in heat production by monocytes was also observed in association with phagocytosis, but it was much less obvious than that by neutrophils. Heat production can thus be used as a quantitative measure of phagocytosis. PMID:3283245

Hayatsu, H; Miyamae, T; Yamamura, M

1988-05-01

66

A three-dimensional inverse problem in imaging the local heat transfer coefficients for plate finned-tube heat exchangers  

Microsoft Academic Search

A three-dimensional inverse heat conduction problem in imaging the local heat transfer coefficients for plate finned-tube heat exchangers utilizing the steepest descent method and a general purpose commercial code CFX4.4 is applied successfully in the present study based on the simulated measured temperature distributions on fin surface by infrared thermography.It is assumed that no prior information is available on the

Cheng-Hung Huang; I-Cha Yuan; Herchang Ay

2003-01-01

67

Local and transient structural changes in stratum corneum at high electric fields: Contribution of Joule heating  

Microsoft Academic Search

Electroporation of skin is accompanied by local heating, such that thermally induced structural changes of the stratum corneum (SC) accompany the field effect. Comparing on the time scale, the local changes in structure, temperature and conductance of the SC, during and after the pulse, it is seen that Joule heating also facilitates the subsequent molecular transport. It is found that

U. Pliquett; S. Gallo; S. W. Hui; Ch. Gusbeth; E. Neumann

2005-01-01

68

A Simple Atmospheric Model of the Local and Teleconnection Responses to Tropical Heating Anomalies  

Microsoft Academic Search

A minimal complexity model of both the local and remote stationary responses of the atmosphere to tropical heating anomalies is described and demonstrated. Two levels are recast as baroclinic and barotropic components with thermal advection in the tropics neglected. The model is linearized about some idealized and realistic background wind fields and forced with a localized heating for illustration. In

Sang-Ki Lee; Chunzai Wang; Brian E. Mapes

2009-01-01

69

Generalization of experimental data on local heat transfer over the plane surfaces of a curved duct  

NASA Astrophysics Data System (ADS)

A method is proposed for generalizing experimental data on local heat transfer over a flat end surface of a curved duct of rectangular cross-section with comparable side dimensions. A similarity equation for local heat transfer is obtained which allows for the effect of the curvature of flow lines, transverse flows in the boundary layer, flow laminarization, and longitudinal pressure gradient.

Khalatov, A. A.; Kapitanchuk, K. I.; Malkov, V. A.

70

Measurement of localized heating in the focus of an optical trap  

SciTech Connect

Localized heating in the focus of an optical trap operating in water can result in a temperature rise of several kelvins. We present spatially resolved measurements of the refractive-index distribution induced by the localized heating produced in an optical trap and infer the temperature distribution. We have determined a peak temperature rise in water of 4 K in the focus of a 985-nm-wavelength 55-mW laser beam. The localized heating is directly proportional to power and the absorption coefficient. The temperature distribution is in excellent agreement with a model based on the heat equation. (c) 2000 Optical Society of America.

Celliers, Peter M. [Lawerence Livermore National Laboratory, P. O. Box 808, Livermore, California 94550 (United States); Conia, Jerome [Cell Robotics, Inc., 2715 Broadbent Parkway NE, Albuquerque, New Mexico 87107 (United States)

2000-07-01

71

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

SciTech Connect

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.

Bolte, J.; Niebisch, F.; Pelzl, J. [Fakultaet fuer Physik und Astronomie, Festkoerperspektroskopie, Ruhr-Universitaet Bochum, D-44780 Bochum (Germany); Stelmaszyk, P.; Wieck, A. D. [Fakultaet fuer Physik und Astronomie, Angewandte Physik, Ruhr-Universitaet Bochum, D-44780 Bochum (Germany)

1999-03-15

72

A meshless local boundary integral equation method for heat conduction analysis in nonhomogeneous solids  

Microsoft Academic Search

A local boundary integral equation method (LBIEM) with meshless approximation for heat conduction analysis in non?homogeneous solids is presented. A review of recent developments in advanced meshless LBIEM for 2?d, 3?d axisymmetric problems and microwave heating analysis is given. Both stationary and transient heat conduction problems are investigated in the paper. For transient problems both the Laplace transform technique and

Jan Sladek; Vladimir Sladek; Chuanzeng Zhang

2004-01-01

73

Production and Localization of Inulinases in 'Kluyveromyces' Yeasts.  

National Technical Information Service (NTIS)

In the thesis a physiological study on the production and localization of inulinase in Kluyveromyces yeasts, and especially in K. marxianus var. marxianus CBS 6556, is presented. It includes a biochemical study into the nature of the glycoprotein inulinas...

R. J. Rouwenhorst

1990-01-01

74

PM DEVELOPMENT TASK 5.0 LOCAL BOILING HEAT TRANSFER TESTS. Single Tube Heat Transfer and Pressure Drop Tests  

Microsoft Academic Search

Local boiling heat transfer and pressure drop data were obtained on the ; inside of a single tube test section which was dimensionally identical to a PM-1 ; fuel element. A total of 242 experimental runs were performed, including l32 ; local boiling runs. The test parameters covered were: system pressure from 800 ; to l500 psia; flow rates of

J. J. Jr. Jicha; S. Frank

1961-01-01

75

Zirconium alloy heat treatment process and product  

SciTech Connect

Zirconium-base alloy channels and fuel cladding tubes having unique resistance to accelerated pustular corrosion in the boiling water reactor environment are produced by a heat treatment causing segregation of intermetallic particulate precipitate phase in two dimensional arrays preferably located along grain boundaries and subgrain boundaries throughout the alloy body.

Black, T.J.; Proebstle, R.A.; Urquhart, A.W.; Walker, J.L.; Williams, C.D.

1980-12-09

76

Urban Heat Islands and Their Mitigation vs. Local Impacts of Climate Change  

Microsoft Academic Search

Urban heat islands and their mitigation take on added significance, both negative and positive, when viewed from a climate-change perspective. In negative terms, urban heat islands can act as local exacerbating factors, or magnifying lenses, to the effects of regional and large-scale climate perturbations and change. They can locally impact meteorology, energy\\/electricity generation and use, thermal environment (comfort and heat

H. Taha

2007-01-01

77

Radiogenic heat production, thermal regime and evolution of continental crust  

NASA Astrophysics Data System (ADS)

Heat flow and heat production data complement seismic information and provide strong constraints on crustal composition, thickness and evolution. They have helped understand the nature of the Mohorovicic discontinuity and the variations in seismic velocities below the Moho. Notably, heat flow studies have delineated the vertical distribution of heat producing elements throughout the crust and in the upper most mantle lithosphere. Analysis of global data sets on heat flow and crustal thickness demonstrate that there is no correlation between these two variables. This is due to the large spatial variations in crustal composition and heat production that exist within a single geological province. For a given crustal thickness, the Moho temperature varies within a wide range (? 300 K) depending on surface heat flux and crustal heat production. Thus one cannot use generic models based on a "type" crustal column to calculate crustal geotherms. In stable regions, lower crustal temperatures depend on the amount and vertical distribution of heat producing elements in the crust. These temperatures determine the conditions of crustal stability and impose a limit on the maximum thickness of a stabilized crust.

Mareschal, Jean-Claude; Jaupart, Claude

2013-12-01

78

GREENHOUSE PRODUCTION OF BEDDING AND FOLIAGE PLANTS WITH INDUSTRIAL HEAT  

EPA Science Inventory

The report gives results of an evaluation of potentially beneficial uses of industrial waste heat for production of bedding and foliage plants, using conventionally and warm-water heated greenhouses in Fort Valley, GA. Each greenhouse was a plastic covered, 30 x 72-ft quonset. Th...

79

Flat Plate Heat Exchangers for the New Production Reactor.  

National Technical Information Service (NTIS)

The New Production Reactor (NPR) will require heat exchangers (HX) as part of the ancillary equipment. The most common type of heat exchanger in the US is the shell and tube, the type presently in SRP reactor service. This type of design is the one that i...

R. S. Ondrejcin

1988-01-01

80

Endothelial nitric oxide synthase mediates cutaneous vasodilation during local heating and is attenuated in middle-aged human skin  

PubMed Central

Local skin heating is used to assess microvascular function in clinical populations because NO is required for full expression of the response; however, controversy exists as to the precise NO synthase (NOS) isoform producing NO. Human aging is associated with attenuated cutaneous vasodilation but little is known about the middle aged, an age cohort used for comparison with clinical populations. We hypothesized that endothelial NOS (eNOS) is the primary isoform mediating NO production during local heating, and eNOS-dependent vasodilation would be reduced in middle-aged skin. Vasodilation was induced by local heating (42°C) and during acetylcholine dose-response (ACh-DR: 0.01, 0.1, 1.0, 5.0, 10.0, 50.0, 100.0 mmol/l) protocols. Four microdialysis fibers were placed in the skin of 24 men and women; age cohorts were 12 middle-aged (53 ± 1 yr) and 12 young (23 ± 1 yr). Sites served as control, nonselective NOS inhibited [NG-nitro-l-arginine methyl ester (l-NAME)], inducible NOS (iNOS) inhibited (1400W), and neuronal NOS (nNOS) inhibited (N?-propyl-l-arginine). After full expression of the local heating response, l-NAME was perfused at all sites. Cutaneous vascular conductance was measured and normalized to maximum (%CVCmax: Nitropress). l-NAME reduced %CVCmax at baseline, all phases of the local heating response, and at all ACh concentrations compared with all other sites. iNOS inhibition reduced the initial peak (53 ± 2 vs. 60 ± 2%CVCmax; P < 0.001); however, there were no other differences between control, nNOS-, and iNOS-inhibited sites during the phases of local heating or ACh-DR. When age cohorts were compared, NO-dependent vasodilation during local heating (52 ± 6 vs. 68 ± 4%CVCmax; P = 0.013) and ACh perfusion (50 mmol/l: 83 ± 3 vs. 93 ± 2%CVCmax; 100 mmol/l: 83 ± 4 vs. 92 ± 3%CVCmax; both P = 0.03) were reduced in middle-aged skin. There were no differences in NOS isoform expression obtained from skin biopsy samples between groups (all P > 0.05). These data suggest that eNOS mediates the production of NO during local heating and that cutaneous vasodilation is attenuated in middle-aged skin.

Bruning, Rebecca S.; Santhanam, Lakshmi; Stanhewicz, Anna E.; Smith, Caroline J.; Berkowitz, Dan E.; Kenney, W. Larry

2012-01-01

81

NGNP Process Heat Applications: Hydrogen Production Accomplishments for FY2010  

SciTech Connect

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.

Charles V Park

2011-01-01

82

Spectral Retrieval of Latent Heating Profiles from TRMM PR data.: Version-7 Heating Products  

NASA Astrophysics Data System (ADS)

The first satellite mission dedicated to measure rainfall, the Tropical Rainfall Measuring Mission (TRMM), was launched in the late November 1997 and greatly has been providing a wealth of information related to precipitation in the Tropics. The TRMM standard products have version numbers that are incremented each time the data are reprocessed to reflect an advancement of the TRMM standard products (Kummerow et al. 2000). Recently, version 7 of the TRMM standard products has been published by NASA and JAXA. The differences between version 7 of the Precipitation Radar (PR) and the TRMM Microwave Imager (TMI) standard rainfall products have narrowed compared to prior products (version 5 and 6). The primary goal of TRMM is to use this precipitation information to determine the four-dimensional (i.e., temporal and spatial) patterns of latent heating over the whole tropical region. In version 7 of the TRMM standard products, latent heating estimates was introduced. The Spectral Latent Heating algorithm (SLH; Shige et al. 2004, 2007, 2008, 2009) is employed to obtain latent heating from the PR rainfall product (TRMM product 2A25; Iguchi et al. 2009), while the Convective Stratiform Heating algorithm (CSH; Tao et al. 1993, 2010) employed to obtain latent heating from the TRMM Combined Instrument product, which employs data from both PR and TMI (TRMM product 2B31; Haddad et al. 1997). This paper describes the revised SLH for the version 7 of PR heating products. Less agreement between SLH-retrieved heating and sounding-based heating for the South China Sea Monsoon Experiment (SCSMEX) was found when the SLH algorithm was applied to the version 7 of PR rainfall products than the version 6 of PR rainfall products. This problem was caused by the fact that the algorithm did not estimate lower-level cooling of deep stratiform rain when the rain intensity below the melting level increases downward. Stratiform heating retrieval is now separated into downward decrease and downward increase of the rain intensity below the melting level, resulting in the better agreement. Revised procedure for heating retrieval over mountainous regions and region with low melting level height is also described.

Shige, S.; Takayabu, Y. N.; Kachi, M.; Hamada, A.; Mega, T.; Tao, W.

2012-12-01

83

Volatile by-products during heat polymerization of soybean oil  

Microsoft Academic Search

Volatile by-products during heat polymerization of soybean oil at 330C were analyzed using GC-MS and NMR. Color and viscosity\\u000a changes were monitored for the heat-polymerized soybean oil and the by-products. About 90% (w\\/w) of the by-products were decanoic,\\u000a palmitic, linoleic, oleic, and stearic acids and cis-9-tricosene. The by-products also contained small amounts of 3-eicosene, 9,17-octadecadienal, and cyclotetracosene. The weight\\u000a percentage

Sevim Z. Erhan; Quan Sheng; Hong-Sik Hwang

2003-01-01

84

LIFE CYCLE ASSESSMENT OF AN ENERGY-SYSTEM WITH A SUPERHEATED STEAM DRYER INTEGRATED IN A LOCAL DISTRICT HEAT AND POWER PLANT  

Microsoft Academic Search

Life cycle assessment (LCA) is a method for analysing and assessing the environmental impact of a material, product or service throughout the entire life cycle. In this study 100 GWh heat is to be demanded by a local heat district. A mixture of coal and wet biofuel is frequently used as fuel for steam generation (Case 1). A conversion of

Hans Bjork; Anders Rasmuson

1999-01-01

85

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

SciTech Connect

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.

Pferdehirt, W.; Kron, N. Jr.

1980-11-01

86

Using local clays and waste products to produce facing tiles  

Microsoft Academic Search

This paper deals with the production of tile bodies based on the local raw materials of the Gorodok deposit (Gomel' district) and the waste products of the Dobrush Porcelain Factory (sediments of the sewage water of the factory). A systematic study of the \\

I. M. Tereshchenko; I. S. Kachan; A. V. Deshkovets; O. I. Livshits; Ya. I. Moiseeva; N. P. Belyi

1986-01-01

87

Heat Pipe Solar Receiver for Oxygen Production of Lunar Regolith  

NASA Astrophysics Data System (ADS)

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.

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

2009-03-01

88

Characterisation of local ICRF heat loads on the JET ILW  

NASA Astrophysics Data System (ADS)

When using Ion Cyclotron Range of Frequency (ICRF) heating, enhanced heat-fluxes are commonly observed on some plasma facing components close to the antennas. Experiments have recently been carried out on JET with the new ITER-Like-Wall (ILW) to characterize the heat flux to the JET ICRF antennas. Using Infra-Red thermography and thermal models of the tiles, heat-fluxes were evaluated from the surface temperature increase during the RF phase of L-mode plasmas. The maximum observed heat-flux intensity was ˜4.5 MW/m2 when operating with -?/2 current drive strap phasing at power level of 2 MW per antenna and with a 4 cm distance between the plasma and the outer limiters. Heat-fluxes are reduced when using dipole strap phasing. The fraction of ICRF power deposited on the antenna limiters or septa was in the range 2-10% for dipole phasing and 10-20% with ± ?/2 phasing.

Jacquet, P.; Marcotte, F.; Colas, L.; Arnoux, G.; Bobkov, V.; Corre, Y.; Devaux, S.; Gardarein, J.-L.; Gauthier, E.; Graham, M.; Lerche, E.; Mayoral, M.-L.; Monakhov, I.; Rimini, F.; Sirinelli, A.; Van Eester, D.; JET EFDA contributors

2013-07-01

89

The Invisible Heat: Heat-Production By Strain In The Continental Crust  

Microsoft Academic Search

The production of leucogranites and high-temperature metamorphism in thickened orogens has been an intriguing problem because of the difficulty of producing sufficient heat to cause them. Deep burial of crustal materials with high radioactive element contents or unusually high mantle heat flux have been considered as sources of elevated T in thickened continental lithosphere. Following previous suggestions, we argue that

P. I. Nabelek; A. G. Whittington; A. Hofmeister

2009-01-01

90

Influence of cooling conditions on the local parameters of heat and mass transfer in condensation heat-utilization units  

NASA Astrophysics Data System (ADS)

Based on the earlier developed model of calculation of the local parameters of heat and mass transfer in deep cooling of flue gases (a vapor-gas mixture) in a bundle of tubes of a condensation heat-utilization unit, the distribution of the parameters of a condensing vapor-gas mixture both along the length of the tubes and in the depth of the tube bundle in a crossflow under various cooling conditions corresponding to the working parameters of heat-utilization units at industrial thermoelectric plants (TEP) and in boiler houses has been obtained. A comparison of the calculated values of the heating efficiency of the indicated heat-utilization unit with the results of tests of the condensation heat-utilization unit at the Ul'yanovsk TEP-3 (Russia) has demonstrated their satisfactory agreement.

Borodulya, V. A.; Malevich, V. L.; Sinkevich, A. E.

2012-01-01

91

Control of Grain Structure in Pure Copper by a Local Heating  

NASA Astrophysics Data System (ADS)

The present work deals with a preferential grain growth process in a localized region utilizing local heating method in order to fabricate some unique microstructures different from those fabricated in the homogeneous way of microstructure evolution. A Monte Carlo simulation of grain growth under a heterogeneous temperature gradient, i.e. spot heating, was performed. Steep temperature gradient brought about a preferential grain growth in the higher temperature region, showing that the local heating was effective for the control of grain structure of polycrystalline materials. Such type of preferential grain growth became less significant under the mild temperature gradient. Local heating of pure copper foil with 0.2mm in thickness utilizing laser beam was performed by changing the irradiation conditions. In the case of 200W for laser power and 18mm/s for sweep velocity, some grains were observed to have larger grain sizes than their surrounding grains, suggesting a possibility of preferential grain growth in the localized region.

Shibayanagi, Toshiya; Tsukamoto, Masahiro; Abe, Nobuyuki

92

Studies of local electron heat transport on TFTR  

SciTech Connect

The anomalously fast relaxation of the perturbations to the electron temperature profile caused by a sawtooth crash has been studied extensively on TFTR. We will show that on a short timescale the heat pulse is not simply diffusive as has been generally assumed, but that modeling of the heat pulse requires a transient enhancement in {chi}{sub e} following the sawtooth crash. It will be shown that the time-dependent enhancement in {chi}{sub e} predicted by non-linear thermal transport models, i.e., incremental {chi} models or the Rebut-Lallia-Watkins transport model, is much smaller than that required to explain the anomalies in the heat pulse propagation.

Fredrickson, E.D.; Chang, Z.Y.; Janos, A.; McGuire, K.M.; Scott, S.; Taylor, G.

1993-08-16

93

Production Of Liquid Alum Coagulant From Local Saudi Clays  

Microsoft Academic Search

This study was carried out to investigate the use of local clays extremely abundant in the Kingdom for production of liquid alum. Local kaolinitic clay containing 29.4% Al2O3 was ground, activated by calcination and treated with sulfuric acid solution to extract alumina. In the activation step, the effects of grain size of clay, temperature and period of calcination on the

A. AL-ZAHRANI; M. H. ABDEL-MAJID

94

Local nucleation propagation on heat transfer uniformity during subcooled convective boiling  

NASA Astrophysics Data System (ADS)

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.

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

2014-05-01

95

New technique of the local heat flux measurement in combustion chambers of steam boilers  

NASA Astrophysics Data System (ADS)

A new method for measurement of local heat flux to water-walls of steam boilers was developed. A flux meter tube was made from an eccentric tube of short length to which two longitudinal fins were attached. These two fins prevent the boiler setting from heating by a thermal radiation from the combustion chamber. The fins are not welded to the adjacent water-wall tubes, so that the temperature distribution in the heat flux meter is not influenced by neighbouring water-wall tubes. The thickness of the heat flux tube wall is larger on the fireside to obtain a greater distance between the thermocouples located inside the wall which increases the accuracy of heat flux determination. Based on the temperature measurements at selected points inside the heat flux meter, the heat flux absorbed by the water-wall, heat transfer coefficient on the inner tube surface and temperature of the water-steam mixture was determined.

Taler, Jan; Taler, Dawid; Sobota, Tomasz; Dzierwa, Piotr

2011-12-01

96

Localized induction heating solder bonding for wafer level MEMS packaging  

NASA Astrophysics Data System (ADS)

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.

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

2005-02-01

97

Interfacing primary heat sources and cycles for thermochemical hydrogen production  

SciTech Connect

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.

Bowman, M.G.

1980-01-01

98

The Therapeutic Use of Local Heat and Cold  

PubMed Central

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.

Tepperman, Perry S.; Devlin, Michael

1986-01-01

99

The Direct Contact Heat Exchanger: Experiences on Ice Slurry Production  

Microsoft Academic Search

An experimental pilot scale of direct contact heat exchanger (DCHE) for ice slurry production was fabricated and evaluated. The study investigated the DCHE of Ø114mm and 1000 mm height using evaporated refrigerant as disperse phase and solidified water as continuous phase. The heat transfer rate across the DCHE was varied between 3.0 and 6.5 kW while the water flow rate

Raksit Thitipatanapong; Bundit Limmeechokchai

100

The Invisible Heat: Heat-Production By Strain In The Continental Crust  

NASA Astrophysics Data System (ADS)

The production of leucogranites and high-temperature metamorphism in thickened orogens has been an intriguing problem because of the difficulty of producing sufficient heat to cause them. Deep burial of crustal materials with high radioactive element contents or unusually high mantle heat flux have been considered as sources of elevated T in thickened continental lithosphere. Following previous suggestions, we argue that strain-heating is an important heat-producing mechanism in crustal shear zones and ultimately can lead to melting and high-temperature metamorphism. Heat production (W/m3) by strain in the ductile regime is given by the product of shear-strength and strain-rate. Using recently published power-law parameters for rheology of crustal materials, calculations show that deformation of dry quartzite at strain-rate of 3x10-13 s-1 at 450° C produces 580 ?W/m3 but the heat production diminishes as T increases to ~7 ?W/m3 at 800° C. Deformation of a stronger material such as pyroxene at this strain-rate produces >10 ?W/m3 even at 1000° C. These values greatly exceed the normal volumetric radiogenic heat production in upper crustal rocks of 2-3 ?W/m3. The maximum heat production at lower temperatures is limited by the brittle strength of rocks as expressed by Byerlee’s law. 1-D and 2-D numerical simulations were conducted to examine the effects of heat-production within deep crustal shear zones on the crustal geotherm. The lithosphere was assumed to be 130 km thick with Moho at 70 km depth. T at the bottom was fixed at 1300° C. The top 35 km of the crust had exponentially decreasing radiogenic heat-production (Arad) with depth while the lower crust had Arad of 0.2 ?W/m3 and the mantle lithoshere 0.02 ?W/m3. Temperature-dependent rheologies, thermal diffusivity, and heat capacities were applied. The simulations show that T’s >1000° C are reached in the vicinity of a shear zone deforming at 3x10-13 s-1 (equivalent to translation of 3 cm/y) within 10 Ma, assuming a pyroxene rheology. Heat-production by deformation of a weaker rock with a combination of quartz and feldspar rheologies is less efficient, but nevertheless temperatures that are required for dehydration melting of muscovite are reached within several 10’s of Ma after initiation of deformation. An inverted geothermal gradient is retained below a shallow-dipping shear zone for much of the duration of thrusting because of lower thermal diffusivity at high temperatures. The strain-heating mechanism directly couples heat-production to deformation in the crust, which is ultimately determined by tectonic forcing. The occurrence of leucogranites within crustal shear-zone systems and high strains seen in granulites are evidence of coupling between deformation and heat production in the crust.

Nabelek, P. I.; Whittington, A. G.; Hofmeister, A.

2009-12-01

101

Thermal-Electrical FEA of Localized Heating for MEMS Packaging.  

National Technical Information Service (NTIS)

Localized silicon fusion and eutectic bonding for MEMS packaging have been preliminarily investigated through the U.S. Army SBIR Phase I program entitled 'Multi- Power Source for MEMS Packaging', contract No.: W56HZV-05-C- 0092. This methodology allows lo...

C. L. Xie G. Newaz J. J. Mabesa M. Hailat

2006-01-01

102

A local BIEM for analysis of transient heat conduction with nonlinear source terms in FGMs  

Microsoft Academic Search

The diffusion equation with nonlinear heat source intensity in functionally graded materials (FGMs) is considered. In FGMs the thermal material properties are dependent on spatial coordinates. For transient or steady-state heat problems in FGMs the conventional boundary integral equation method or boundary element method cannot be applied due to the lack of a fundamental solution. In this paper, a local

Jan Sladek; Vladimir Sladek; Ch. Zhang

2004-01-01

103

Remotely actuated localized pressure and heat apparatus and method of use  

NASA Technical Reports Server (NTRS)

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.

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

2004-01-01

104

Flow boiling of pure fluids: local heat transfer and flow pattern modeling through artificial neural networks  

Microsoft Academic Search

A new modeling technique based on neural networks as a universal function approximator has been applied to study the local representation of flow boiling heat transfer at varying fluid dynamics conditions along the tube, i.e., moving through different flow pattern regions. After subdivision of the experimental data into subsets homogeneous for flow conditions, specific heat transfer equations have been heuristically

G. Scalabrin; M. Condosta; P. Marchi

2006-01-01

105

Inverse estimation of the local heat transfer coefficient in curved tubes: a numerical validation  

NASA Astrophysics Data System (ADS)

Wall curvature represents one of the most used passive techniques to enhance convective heat transfer. The effectiveness of wall curvature is due to the fact that it gives origin to the centrifugal force: this phenomenon induces local maxima in the velocity distribution that locally increase the temperature gradients at the wall by then maximizing the heat transfer. This fact brings to a significant variation of the wall temperature and of the wall heat flux along the circumferential coordinate. The convective heat transfer coefficient is consequently not uniformly distributed along the tube's perimeter and is characterized by higher values at the extrados wall surface in comparison to the ones at the intrados wall surface. Therefore, for predicting the overall performance of heat transfer apparatuses that involve the use of curved tubes, it becomes important to know the local distribution of the convective heat transfer coefficient not only along the axis of the heat transfer section, but also on the internal tube's surface along the cross section circumference. The present paper is intended to the assessment of a procedure developed to evaluate the local convective heat transfer coefficient, along the circumferential coordinate, at the internal wall of a coiled pipe.

Bozzoli, F.; Cattani, L.; Corradi, C.; Mordacci, M.; Rainieri, S.

2014-04-01

106

Transient heat conduction analysis in functionally graded materials by the meshless local boundary integral equation method  

Microsoft Academic Search

Advanced computational method for transient heat conduction analysis in continuously nonhomogeneous functionally graded materials (FGM) is proposed. The method is based on the local boundary integral equations with moving least square approximation of the temperature and heat flux. The initial-boundary value problem is solved by the Laplace transform technique. Both Papoulis and Stehfest algorithms are applied for the numerical Laplace

J. Sladek; V. Sladek; Ch. Zhang

2003-01-01

107

Heat transport and phonon localization in mass-disordered harmonic crystals  

Microsoft Academic Search

We investigate the steady-state heat current in two- and three-dimensional disordered harmonic crystals in a slab geometry connected at the boundaries to stochastic white-noise heat baths at different temperatures. The disorder causes short-wavelength phonon modes to be localized so the heat current in this system is carried by the extended phonon modes which can be either diffusive or ballistic. Using

Abhishek Chaudhuri; Anupam Kundu; Dibyendu Roy; Abhishek Dhar; Joel L. Lebowitz; Herbert Spohn

2010-01-01

108

Evidence for localized cell heating induced by infrared optical tweezers  

SciTech Connect

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 {similar_to}1.45{plus_minus}0.15 {degree}C/100 mW is observed when the vesicles are held stationary with a 1.064 {mu}m optical tweezers having a power density of {similar_to}10{sup 7} W/cm{sup 2} and a focused spot size of {similar_to}0.8 {mu}m. 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{plus_minus}0.25 {degree}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. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.

Liu, Y.; Cheng, D.K.; Sonek, G.J. [Department of Electrical and Computer Engineering and Beckman Laser Institute and Medical Clinic, University of California, Irvine, California 92717 (United States); Berns, M.W.; Chapman, C.F.; Tromberg, B.J. [Department of Biophysics, and Beckman Laser Institute and Medical Clinic, University of California, Irvine, California 92717 (United States)

1995-05-01

109

Cost allocation and product costing in Dutch local government  

Microsoft Academic Search

The importance of cost allocation and product costing in Dutch local government organizations is increasing for two reasons: first, due to a switch from centralized to decentralized control, which implies a stronger responsibility by divisional managers for the transformation of inputs into outputs; second, because of growing pressure to deliver more value for money, which may lead to incentives for

G. Jan Van Helden

1997-01-01

110

Local heat transfer analysis for boiling of hydrocarbons in complex geometries: A new approach for heat transfer prediction in staggered tube bundle  

Microsoft Academic Search

This paper deals with heat transfer analysis for boiling flow in staggered tube bundle. A local analysis is performed to determine the heat transfer coefficient linked to local flow regimes by optical fibre. The first part of the paper is devoted to the literature survey of the main existing studies on the topic. We show that published heat transfer correlations

L. Aprin; P. Mercier; L. Tadrist

2011-01-01

111

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

SciTech Connect

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.

Dr. Ronald D. Boyd

2000-07-01

112

Heat conduction and Fourier's law by consecutive local mixing and thermalization.  

PubMed

We present a first-principles study of heat conduction in a class of models which exhibit a new multistep local thermalization mechanism which gives rise to Fourier's law. Local thermalization in our models occurs as the result of binary collisions among locally confined gas particles. We explore the conditions under which relaxation to local equilibrium, which involves no energy exchange, takes place on time scales shorter than that of the binary collisions which induce local thermalization. The role of this mechanism in multiphase material systems such as aerogels is discussed. PMID:18764167

Gaspard, P; Gilbert, T

2008-07-11

113

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

NASA Technical Reports Server (NTRS)

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.

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

1984-01-01

114

Determination of the heating temperature of fishery products.  

PubMed

The German Fish Directive prescribes that products must be heated to the core temperature of +70 degrees C to kill existing larvae of nematodes. For subsequent determination of the heating temperature samples were extracted with water. The extracts were analysed for protein content, for protein patterns obtained by isoelectric focusing and by using the coagulation test. The suitability of these methods was investigated with heated extracts, heated minced fish flesh, and smoked herring and mackerel. Smoking was performed in the kiln of the institute at controlled temperatures. Analysis of commercial samples showed that the core temperature during smoking of herring and mackerel must have been clearly below 70 degrees C in several cases. PMID:1462706

Rehbein, H

1992-11-01

115

New industrial heat pump applications to ethanol production  

SciTech Connect

An energy cost reduction study of the Midwest Grain Products, Atchison, Kansas Beverage grade alcohol (from grain) and speciality starch plant has been completed. The objective was to find out 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 alcohol plants, due to the similarity of processes throughout the industry. This study and others indicate that reductions in thermal energy consumption of 10--30% can be expected through increased heat recovery. Additional energy cost reductions can be achieved through the use of MVR evaporators and other heat pump systems. 16 figs., 3 tabs.

Not Available

1990-04-01

116

EVALUATING HEAT INTEGRATION SCHEME FOR BATCH PRODUCTION OF OLEIC ACID  

Microsoft Academic Search

Research works on Process System Engineering are well established for conventional sectors of bulk chemical manufacturing, such as that in the oil and gas and petrochemical industries. However, relatively less attention has been given to the area of bio-related and fine chemical production. This paper demonstrates the use of process synthesis and analysis tools in evaluating heat integration schemes for

Chew Yin Hoon; Lee Chew Tin; Dominic Foo; Chwan Yee

117

Heat Production and Optimal Cooling for Navy Special Warfare Divers.  

National Technical Information Service (NTIS)

This report is a review of the literature regarding heat production and optimal cooling of divers swimming underwater. In previous studies, divers fin swimming at paces sustainable for at least 20 min showed oxygen consumption rates (VO2) ranging from 1.2...

M. B. Beckett J. A. Hodgdon

1991-01-01

118

The Heat is On: Understanding Local Climate Change  

NSDL National Science Digital Library

The is a curriculum module from the project Data Sets and Inquiry in Geoscience Education (DIGS). The module consists of a week-long unit and two-day performance assessment in which students apply the inquiry skills to problem-based investigations of urban micro-climates. The unit and performance assessment present semi-parallel tasks but about different cities (Phoenix and Chicago). Sudents draw conclusions about the extent to which multiple decades of temperature data about Phoenix suggest that a shift in local climate is taking place as opposed to exhibiting nothing more than natural variability. The data are from the Global Climate Historical Network (GHCN) database. GHCN is a large, multi-year, international project to measure temperature, precipitation, and air pressure from near the ground. Each monthly maximum and minimum temperature is the highest and lowest temperature reading for the month, measured in Celsius. In Phoenix and in most other places, the temperature data are collected at local airports. The performance assessment for this module requires that students apply the methods and findings from the investigation of the climate data for Phoenix to climate data for Chicago. The Chicago data shows less evidence of trends in temperature change, and this is most evident comparing the night-time minimum temperature fluctuations between the two cities. Chicago also exhibits less increase in urban development and population growth than does Phoenix. In contrast to the curriculum unit, which primarily uses constructed-response tasks to encourage student explanation and discussion, the climate assessment tasks pose explicit selected- and constructed-response questions to ensure that the items elicit the intended thinking and hence provide evidence of the targeted standards-aligned skills and understandings.

Zalles, Dan

119

Creating a Local Climate Product Using Composite Analysis  

NSDL National Science Digital Library

This Webcast features Heather Hauser of NOAA/ERH/SSD describing the utility of and introducing the methodology for conducting composite analysis as part of the NWS Climate Services program. This 30-minute presentation is intended to introduce climate focal points to the composite analysis process and will be a useful prerequisite to attending the Operational Climate Services residence courses, where the topic will be explored further. Composite analysis is the foundation of a forthcoming local climate-related product, the 3 Month Outlook of Local El Nino/La Nina Impacts.

Spangler, Tim

2005-07-01

120

Fundamental Study of Local Heat Transfer in Forced Convective Boiling of Ammonia on Vertical Flat Plate  

NASA Astrophysics Data System (ADS)

In the present study, the fundamental experiments that investigate characteristics of local heat transfer in forced convective boiling on vertical flat plate with 2-mm channel height are taken to realize plate type compact evaporator for OTEC or STEC. The experiments are performed with ammonia as the working fluid. The experiments are also carried out with the following test conditions; saturated pressure = 0.7, 0.8, 0.9 MPa, mass flux = 7.5, 10, 15 kg/(m2•s), heat flux = 15, 20, 25 kW/m2 and inlet quality = 0.1 ~ 0.4 [-]. The result shows that the wall superheated temperature of forced convective boiling is lower than that of pool boiling. And the heat transfer coefficient increases with an increase in quality and the decrease in the local heat flux and saturated pressure for prescribed experimental conditions. However, local heat transfer coefficients are not affected by mass fluxes in the prescribed experimental conditions. An empirical correlation that can predict the local heat transfer coefficient on vertical flat plate within experimental conditions is also proposed.

Kim, Jeong-Hun; Arima, Hirofumi; Ikegami, Yasuyuki

121

Differential heat shock protein localization in chronic lymphocytic leukemia.  

PubMed

Mechanisms behind carcinogenesis and resistance of tumor cells to treatment regimes remain elusive. The major stress proteins Hsp72, Hsp90, and Hsp27 are credible candidates to provide this resistance, as their overexpression in many cancer types is well documented. In addition to being present inside tumor cells, where they confer resistance to apoptosis, Hsp72, in particular, is presented externally, embedded in the cell membrane of cancer cells. This study aimed to investigate the localization of Hsp72, Hsp90, and Hsp27 in leukocytes from patients with CLL and age-matched control subjects. CLL patients were found to express significantly higher levels of iHsp90 (CLL=2463 MFI; control=748 MFI) and iHsp27 (CLL=2190 MFI; control=1031 MFI) in lymphocytes than that expressed by lymphocytes from control subjects. Furthermore, expression of iHsp90 was shown to be related to stage of disease, and expression of iHsp27 correlated with levels of active caspase-3. Patients were found to express very high levels or very low levels of sHsp72 and iHsp72 in CD5(+)/CD19(+) cells, although surface and intracellular datasets did not correlate. Levels of extracellular Hsp72 circulating in the serum were found to correlate with internal levels of Hsp72 and were also found to be significantly lower in patients receiving corticosteroid treatment than in patients not receiving corticosteroid treatment. Finally, analysis of the number of circulating Tregs revealed significantly elevated numbers in CLL patients compared with control subjects. PMID:20007907

Dempsey, Nina C; Leoni, Francesca; Ireland, H Elyse; Hoyle, Christine; Williams, John H H

2010-03-01

122

Differential heat shock protein localization in chronic lymphocytic leukemia  

PubMed Central

Mechanisms behind carcinogenesis and resistance of tumor cells to treatment regimes remain elusive. The major stress proteins Hsp72, Hsp90, and Hsp27 are credible candidates to provide this resistance, as their overexpression in many cancer types is well documented. In addition to being present inside tumor cells, where they confer resistance to apoptosis, Hsp72, in particular, is presented externally, embedded in the cell membrane of cancer cells. This study aimed to investigate the localization of Hsp72, Hsp90, and Hsp27 in leukocytes from patients with CLL and age-matched control subjects. CLL patients were found to express significantly higher levels of iHsp90 (CLL=2463 MFI; control=748 MFI) and iHsp27 (CLL=2190 MFI; control=1031 MFI) in lymphocytes than that expressed by lymphocytes from control subjects. Furthermore, expression of iHsp90 was shown to be related to stage of disease, and expression of iHsp27 correlated with levels of active caspase-3. Patients were found to express very high levels or very low levels of sHsp72 and iHsp72 in CD5+/CD19+ cells, although surface and intracellular datasets did not correlate. Levels of extracellular Hsp72 circulating in the serum were found to correlate with internal levels of Hsp72 and were also found to be significantly lower in patients receiving corticosteroid treatment than in patients not receiving corticosteroid treatment. Finally, analysis of the number of circulating Tregs revealed significantly elevated numbers in CLL patients compared with control subjects.

Dempsey, Nina C.; Leoni, Francesca; Ireland, H. Elyse; Hoyle, Christine; Williams, John H. H.

2010-01-01

123

Heat production and chemical change in tortoise muscle  

PubMed Central

1. Measurements have been made of heat production and changes in levels of phosphorylcreatine (PC), ATP and lactic acid resulting from contraction of tortoise muscle under anaerobic conditions. 2. The only significant chemical change found was a break-down of PC. 3. The amount of heat produced per mole of PC split (-?H) was 13·18 ± 1·04 kcal/mole (mean and S.E. from thirty-five observations). 4. (-?H) is probably rather greater in tortoise than in frog muscle. The value of (-?H) cannot easily be accounted for by the known processes accompanying PC splitting in either type of muscle.

Walsh, T. H.; Woledge, R. C.

1970-01-01

124

Intradermal angiotensin II administration attenuates the local cutaneous vasodilator heating response.  

PubMed

The vasodilation response to local cutaneous heating is nitric oxide (NO) dependent and blunted in postural tachycardia but reversed by angiotensin II (ANG II) type 1 receptor (AT(1)R) blockade. We tested the hypothesis that a localized infusion of ANG II attenuates vasodilation to local heating in healthy volunteers. We heated the skin of a calf to 42 degrees C and measured local blood flow to assess the percentage of maximum cutaneous vascular conductance (%CVC(max)) in eight healthy volunteers aged 19.5-25.5 years. Initially, two experiments were performed; in one, Ringer solution was perfused in three catheters, the response to heating was measured, 2 microg/l losartan, 10 mM nitro-l-arginine (NLA), or NLA + losartan was added to perfusate, and the heat response was remeasured; in another, 10 microM ANG II was given, the heat response was measured, losartan, NLA, or NLA + losartan was added to ANG II, and the heat response was reassessed. The heat response decreased with ANG II, particularly the plateau phase (47 +/- 5 vs. 84 +/- 3 %CVC(max)). Losartan increased baseline conductance in both experiments (from 8 +/- 1 to 20 +/- 2 and 12 +/- 1 to 24 +/- 3). Losartan increased the ANG II response (83 +/- 4 vs. 91 +/- 6 in Ringer). NLA decreased both angiotensin and Ringer responses (31 +/- 4 vs. 43 +/- 3). NLA + losartan blunted the Ringer response (48 +/- 2), but the ANG II response (74 +/- 5) increased. In a second set of experiments, we used dose responses to ANG II (0.1 nM to 10 microM) with and without NLA + losartan to confirm graded responses. Sodium ascorbate (10 mM) restored the ANG II-blunted heating plateau. NO synthase and AT(1)R inhibition cause an NO-independent angiotensin-mediated vasodilation with local heating. ANG II mediates the AT(1)R blunting of local heating, which is not exclusively NO dependent, and is improved by antioxidant supplementation. PMID:18469148

Stewart, Julian M; Taneja, Indu; Raghunath, Neeraj; Clarke, Debbie; Medow, Marvin S

2008-07-01

125

Localized heating/bonding techniques in MEMS packaging  

NASA Astrophysics Data System (ADS)

Packaging is used to protect and enable intelligent sensor systems utilized in manned/unmanned ground vehicle systems/subsystems. Because Micro electro mechanical systems (MEMS) are used often in these sensor or actuation products, it must interact with the surrounding environment, which may be in direct conflict with the desire to isolate the electronics for improved reliability/durability performance. For some very simple devices, performance requirements may allow a high degree of isolation from the environment (e.g., stints and accelerometers). Other more complex devices (i.e. chemical and biological analysis systems, particularly in vivo systems) present extremely complex packaging requirements. Power and communications to MEMS device arrays are also extremely problematic. The following describes the research being performed at the U.S. Army Research, Development, and Engineering Command (RDECOM) Tank and Automotive Research, Development, and Engineering Center (TARDEC), in collaboration with Wayne State University, in Detroit, MI. The focus of the packaging research is limited to six main categories: a) provision for feed-through for electrical, optical, thermal, and fluidic interfaces; b) environmental management including atmosphere, hermiticity, and temperature; c) control of stress and mechanical durability; d) management of thermal properties to minimize absorption and/or emission; e) durability and structural integrity; and f) management of RF/magnetic/electrical and optical interference and/or radiation properties and exposure.

Mabesa, J. R., Jr.; Scott, A. J.; Wu, X.; Auner, G. W.

2005-05-01

126

Heat exposure, cardiovascular stress and work productivity in rice harvesters in India: implications for a climate change future.  

PubMed

Excessive workplace heat exposures create well-known risks of heat stroke, and it limits the workers' capacity to sustain physical activity. There is very limited evidence available on how these effects reduce work productivity, while the quantitative relationship between heat and work productivity is an essential basis for climate change impact assessments. We measured hourly heat exposure in rice fields in West Bengal and recorded perceived health problems via interviews of 124 rice harvesters. In a sub-group (n = 48) heart rate was recorded every minute in a standard work situation. Work productivity was recorded as hourly rice bundle collection output. The hourly heat levels (WBGT = Wet Bulb Globe Temperature) were 26-32°C (at air temperatures of 30-38°C), exceeding international standards. Most workers reported exhaustion and pain during work on hot days. Heart rate recovered quickly at low heat, but more slowly at high heat, indicating cardiovascular strain. The hourly number of rice bundles collected was significantly reduced at WBGT>26°C (approximately 5% per°C of increased WBGT). We conclude that high heat exposure in agriculture caused heat strain and reduced work productivity. This reduction will be exacerbated by climate change and may undermine the local economy. PMID:23685851

Sahu, Subhashis; Sett, Moumita; Kjellstrom, Tord

2013-01-01

127

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

PubMed Central

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.

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

128

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

PubMed

The local kinetic energy dissipation rate ?(u,c) in Rayleigh-Bénard 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))=1.05×10(-4)Ra(1.55±0.02)Pr(1.15±0.38). 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

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

2011-10-21

129

Numerical modeling of precessing vortex core in the presence of local heat sources  

NASA Astrophysics Data System (ADS)

Based on the results of numerical simulation of a nonstationary, nonaxisymmetric turbulent swirling gas flow in a tube with local sources of heat release, it is shown that a precessing vortex core (PVC) appears at supercritical values of the swirl parameter as a result of the development of instability of a left-handed bending mode. The dependence of the PVC frequency on the mass flow rate of the gas and the heat-source power has been studied. As the heat-source power increases, the frequency of precession grows while the amplitude of vortex core oscillations drops.

Zavershinskii, I. P.; Kogan, E. Ya.; Makaryan, V. G.; Molevich, N. E.; Porfir'ev, D. P.; Sugak, S. S.

2013-04-01

130

Identification and localization of the FMR-1 protein product  

SciTech Connect

The fragile X syndrome results from amplification of the CGG repeat found in the FMR-1 gene. As a first step in the identification and localization of the FMR-1 gene product, antibodies were raised against different regions of the FMR-1 protein (FMRP). These antibodies were used to analyze FMRP in lymphoblastoid cell lines from patients (n=5) and controls (n=3). FMRP was immunoprecipated and subsequently analyzed by immunoblotting. Four molecular species (67-74 kDa) were found which were absent in 4 of the 5 patients. The lack is in agreement with the absence of FMR-1 mRNA. The patient expressing FMRP`s shows a mosaic DNA pattern with part of the cells carrying a premutation and others carrying a full mutation. The premutation allele is preceded by an unmethylated CpG island and is expressed into FMR-1 mRNA which is subsequently translated into protein. The four different FMRPs most likely result from alternative splicing of the FMR-1 mRNA. Two splice products were mimicked in cDNA constructs transiently expressed in COS-1 cells. Both splice products appeared to encode for stable protein products and were recognized by the antibodies. The molecular weight of the protein products was in agreement with two of the protein products found in the lymphoblastoid cell lines, indicating that the FMRPs detected in lymphoblasts are the result of alternative splicing. The intracellular localization of FMRP in COS-1 cells was cytoplasmatic. The finding of four FMRPs of the same molecular weight in controls and the mosaic patient indicate that the CGG repeat is not translated.

Verheij, C.; Hoogeveen, A.T.; Verkerk, A.J.M.H.; DeGraaf, E.; Bakker, C.; Reuser, A.J.J. [Erasmus Univ., Rotterdam (Netherlands)

1994-07-15

131

A comparative study of the local heat transfer distributions around various surface mounted obstacles  

NASA Astrophysics Data System (ADS)

In many engineering applications, heat transfer enhancement techniques are of vital importance in order to ensure reliable thermal designs of convective heat transfer applications. This study examines experimentally the heat transfer characteristics on the base plate around various surface mounted obstacles. Local convection coefficients are evaluated in the vicinity of each individual protruding body with great spatial resolution using the transient liquid crystal technique. Five different obstacles of constant height-to-hydraulic diameter ratio (˜1.3) are considered. These include: a cylinder, a square, a triangle, a diamond and a vortex generator of delta wing shape design. The experiments were carried out over a range of freestream Reynolds numbers, based on the hydraulic diameter of each obstacle, varying from 4,000 to 13,000. The results indicate a negligible effect of the flow speed on the heat transfer topological structure and a considerable effect of the obstacle geometry on the level and distribution of heat transfer enhancement.

Wyssmann, Robert; Ullmer, Dirk; Terzis, Alexandros; Ott, Peter

2014-04-01

132

Nitric oxide production is enhanced in patients with heat stroke  

Microsoft Academic Search

Objective: To determine whether nitric oxide (NO) production is increased in heat stroke (HS) patients. Design: A prospective analysis of nitrite and nitrate (NO\\u000a \\u000a 2\\/NO3) levels in ten HS patients was performed at the HS center in Makkah, Saudi Arabia. Methods: Plasma (NO\\u000a \\u000a 2\\/NO3) levels were determined spectrophotometrically before cooling (0 time), and at 6, 12, and 24 h post-cooling.

A. H. Alzeer; A. Al-Arifi; A. S. Warsy; Z. Ansari; H. Zhang; J.-L. Vincent

1999-01-01

133

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

NASA Technical Reports Server (NTRS)

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.

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

2006-01-01

134

Application of Thin-Film Thermocouples to Localized Heat Transfer Measurements  

NASA Technical Reports Server (NTRS)

The paper describes a proof-of-concept experiment on thin-film thermocouples used for localized heat transfer measurements applicable to experiments on hot parts of turbine engines. The paper has three main parts. The first part describes the thin-film sensors and manufacturing procedures. Attention is paid to connections between thin-film thermocouples and lead wires, which has been a source of problems in the past. The second part addresses the test arrangement and facility used for the heat transfer measurements modeling the conditions for upcoming warm turbine tests at NASA LeRC. The paper stresses the advantages of a modular approach to the test rig design. Finally, we present the results of bulk and local heat flow rate measurements, as well as overall heat transfer coefficients obtained from measurements in a narrow passage with an aspect ratio of 11.8. The comparison of bulk and local heat flow rates confirms applicability of thin-film thermocouples to upcoming warm turbine tests.

Lepicovsky, J.; Bruckner, R. J.; Smith, F. A.

1995-01-01

135

Effect of functional electrostimulation on impaired skin vasodilator responses to local heating in spinal cord injury  

Microsoft Academic Search

Spinal cord injury (SCI) induces vascular adaptations below the level of the lesion, such as impaired cutaneous vasodilation. However, the mechanisms underlying these differences are unclear. The aim of this study is to examine arm and leg cutaneous vascular conductance (CVC) responses to local heating in 17 able-bodied controls (39 +\\/- 13 yr) and 18 SCI subjects (42 +\\/- 8

Noortje T. L. Van Duijnhoven; Thomas W. J. Janssen; Daniel J. Green; Christopher T. Minson; Maria T. E. Hopman; Dick H. J. Thijssen

2009-01-01

136

Computer-based areal surface temperature and local heat transfer measurements with thermochromic liquid crystals (TLC)  

Microsoft Academic Search

The experimental technique presented is designed to obtain detailed local heat transfer data on both stationary as well as rotating disc-cavity surfaces applicable to gas turbines. The method employed utilizes thin coatings of thermochromic liquid crystals (TLC) as surface temperature indicators under aerodynamically steady but thermally transient experimental conditions. The color display of the liquid crystals is monitored by a

K. H. Platzer; C. Hirsch; D. E. Metzger; S. Wittig

1992-01-01

137

Medical instrument based on a heat pipe for local cavity hypothermia  

NASA Astrophysics Data System (ADS)

The design and results of tests of an instrument based on a heat pipe for local cavity hypothermia are presented. The instrument is a part of a device for noninvasive nonmedical treatment of inflammatory diseases of the organs of the small pelvis, pathologies of alimentary canal, etc.

Vasil'Ev, L. L.; Zhuraviyov, A. S.; Molodkin, F. F.; Khrolenok, V. V.; Zhdanov, V. L.; Vasil'Ev, V. L.; Adamov, S. I.; Tyurin, A. A.

1996-05-01

138

Local Heat Transfer During Condensation with Forced Convection in a Vertical Tube.  

National Technical Information Service (NTIS)

The local heat transfer coefficients during the condensation of pure substances in a vertical tube has been measured by varying separately the mass flux density of the vapor and the trickling quantity. The substances used in the experiments are water and ...

F. Blangetti

1979-01-01

139

AVERAGE AND LOCAL HEAT TRANSFER FOR CROSSFLOW OF LIQUID METAL IN A TUBE BANK  

Microsoft Academic Search

Local and average heat transfer coefficients were obtained for the flow ; of mercury normal to a staggered tube bank. The tube bank consisted of sixty 1\\/; 2-inch tubes, six wide and ten deep, arranged in an equilateral triangular array. ; Results are presented showing the effects of Reyn olds number, Prandtl number, ; wetting of the tube surfaces by

1962-01-01

140

Local hardening behavior of free air balls and heat affected zones of thermosonic wire bond interconnections  

Microsoft Academic Search

The local deformation behavior of the free air ball (FAB) and the heat affected zone (HAZ) of thermosonic wire bond interconnections is of great interest in reliability considerations for current highly integrated microelectronic devices. The mechanical properties of the HAZ have significant influence on the loop stability, which is very critical in fine pitch and long loop applications. On the

C. Dresbach; G. Lorenz; M. Mittag; M. Petzold; E. Milke; T. Muller

2009-01-01

141

Local temperature redistribution and structural transition during joule-heating-driven conductance switching in VO2.  

PubMed

Joule-heating induced conductance-switching is studied in VO2 , a Mott insulator. Complementary in situ techniques including optical characterization, blackbody microscopy, scanning transmission X-ray microscopy (STXM) and numerical simulations are used. Abrupt redistribution in local temperature is shown to occur upon conductance-switching along with a structural phase transition, at the same current. PMID:23868142

Kumar, Suhas; Pickett, Matthew D; Strachan, John Paul; Gibson, Gary; Nishi, Yoshio; Williams, R Stanley

2013-11-13

142

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

SciTech Connect

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.

Waples, Douglas W., E-mail: dwwaples@cs.com

2002-06-15

143

Heat-generating property of a local plasmon resonator under illumination.  

PubMed

We have investigated the heat generation from gold nanoparticles resulting from their local plasma resonance. We have demonstrated the self-assembly of Au nanoparticle arrays/dielectric layer/Ag mirror sandwiches, i.e., a local plasmon resonator, using a dynamic oblique deposition technique. The thicknesses of the Au and dielectric layers were changed combinatorially on a single substrate. As a result, local plasmon resonator chips were successfully fabricated. Because of strong interference, their optical absorption can be controlled between 0.0% and 97% in the near-IR region, depending on the thickness of the dielectric layer. We evaluated the heat generation from Au nanoparticles by measuring the temperature of water with which a cell prepared on a chip is filled under laser illumination. The change in the water temperature is proportional to the optical absorption of the local plasmon resonator chips. This suggests that the photothermal conversion efficiency can be controlled by interference. These features make the application of the local plasmon resonator to nanoheaters, which can spatiotemporally control heat generation, suitable. PMID:21931381

Namura, Kyoko; Suzuki, Motofumi; Nakajima, Kaoru; Kimura, Kenji

2011-09-15

144

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

NASA Technical Reports Server (NTRS)

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.

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

1998-01-01

145

Biogas foer vaerme, el-, och drivmedelsproduktion. (Biogas for production of heat, power and automotive fuels).  

National Technical Information Service (NTIS)

This report gives a description of suitable techniques for production from biogas of heat, power and automotive fuels. Techniques for gas purification and load equalization are also described. Today, district heat production is the most common field of ap...

E. Stroem T. Ekeborg

1991-01-01

146

Hydrogen production from coal using a nuclear heat source  

NASA Technical Reports Server (NTRS)

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.

Quade, R. N.

1976-01-01

147

Study of Heating and Fusion Power Production in ITER Discharges  

SciTech Connect

ITER simulations, in which the temperatures, toroidal angular frequency and currents are evolved, are carried out using the PTRANSP code starting with initial profiles and boundary conditions obtained from TSC code studies. The dependence of heat deposition and current drive on ICRF frequency, number of poloidal modes, beam orientation, number of Monte Carlo particles and ECRH launch angles is studied in order to examine various possibilities and contingencies for ITER steady state and hybrid discharges. For the hybrid discharges, the fusion power production and fusion Q, computed using the Multi-Mode MMM v7.1 anomalous transport model, are compared with those predicted using the GLF23 model. The simulations of the hybrid scenario indicate that the fusion power production at 1000 sec will be approximately 500 MW corresponding to a fusion Q = 10.0. The discharge scenarios simulated aid in understanding the conditions for optimizing fusion power production and in examining measures of plasma performance.

Rafiq, T.; Kritz, A. H.; Bateman, G. [Department of Physics, Lehigh University, Bethlehem, PA 18015 (United States); Kessel, C.; McCune, D. C.; Budny, R. V. [PPPL, Princeton University, PO Box 451, Princeton, NJ 08543 (United States); Pankin, A. Y. [Tech-X Corporation, Boulder, CO 80303 (United States)

2011-10-03

148

Solar production of intermediate temperature process heat, phase 1 design  

NASA Astrophysics Data System (ADS)

The system consists of 42,420 sq ft of parabolic trough, single axis tracking, concentrating solar collectors. The collectors are oriented in a North-South configuration and track East-West. A heat transfer fluid (Gulf Synfluid 4cs) is circulated in a closed loop fashion through the solar collectors and a series of heat exchangers. The inlet and outlet fluid temperatures for the collectors are 370 F and 450 F respectively. These temperatures are constantly maintained via a variable flow rate through the collectors (the flow rate varies in direct proportion to the level of insolation). Superheated steam is the final product of the solar energy system. Final steam quality at the steam generator is 420 F and 165 Psia.

1980-08-01

149

Nonequilibrium Fluctuation-Dissipation Theorem and Heat Production  

NASA Astrophysics Data System (ADS)

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.

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

2014-04-01

150

The global potential of local peri-urban food production  

NASA Astrophysics Data System (ADS)

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.

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

2013-04-01

151

Heat Resistance of Salmonella in Various Egg Products  

PubMed Central

The heat-resistance characteristics of Salmonella typhimurium Tm-1, a reference strain in the stationary phase of growth, were determined at several temperatures in the major types of products produced by the egg industry. The time required to kill 90% of the population (D value) at a given temperature in specific egg products was as follows: at 60 C (140 F), D = 0.27 min for whole egg; D = 0.60 min for whole egg plus 10% sucrose; D = 1.0 min for fortified whole egg; D = 0.20 min for egg white (pH 7.3), stabilized with aluminum; D = 0.40 min for egg yolk; D = 4.0 min for egg yolk plus 10% sucrose; D = 5.1 min for egg yolk plus 10% NaCl; D = 1.0 min for scrambled egg mix; at 55 C (131 F), D = 0.55 min for egg white (pH 9.2); D = 1.2 min for egg white (pH 9.2) plus 10% sucrose. The average Z value (number of degrees, either centigrade or fahrenheit, for a thermal destruction time curve to traverse one logarithmic cycle) was 4.6 C (8.3 F) with a range from 4.2 to 5.3 C. Supplementation with 10% sucrose appeared to have a severalfold greater effect on the heat stabilization of egg white proteins than on S. typhimurium Tm-1. This information should be of value in the formulation of heat treatments to insure that all egg products be free of viable salmonellae. Images

Garibaldi, J. A.; Straka, R. P.; Ijichi, K.

1969-01-01

152

Heat resistance of Salmonella in various egg products.  

PubMed

The heat-resistance characteristics of Salmonella typhimurium Tm-1, a reference strain in the stationary phase of growth, were determined at several temperatures in the major types of products produced by the egg industry. The time required to kill 90% of the population (D value) at a given temperature in specific egg products was as follows: at 60 C (140 F), D = 0.27 min for whole egg; D = 0.60 min for whole egg plus 10% sucrose; D = 1.0 min for fortified whole egg; D = 0.20 min for egg white (pH 7.3), stabilized with aluminum; D = 0.40 min for egg yolk; D = 4.0 min for egg yolk plus 10% sucrose; D = 5.1 min for egg yolk plus 10% NaCl; D = 1.0 min for scrambled egg mix; at 55 C (131 F), D = 0.55 min for egg white (pH 9.2); D = 1.2 min for egg white (pH 9.2) plus 10% sucrose. The average Z value (number of degrees, either centigrade or fahrenheit, for a thermal destruction time curve to traverse one logarithmic cycle) was 4.6 C (8.3 F) with a range from 4.2 to 5.3 C. Supplementation with 10% sucrose appeared to have a severalfold greater effect on the heat stabilization of egg white proteins than on S. typhimurium Tm-1. This information should be of value in the formulation of heat treatments to insure that all egg products be free of viable salmonellae. PMID:4890741

Garibaldi, J A; Straka, R P; Ijichi, K

1969-04-01

153

Sustained laser induced incandescence in carbon nanotubes for rapid localized heating  

SciTech Connect

Sustained laser-induced incandescence (LII) was observed when a continuous wave laser beam was focused on aligned multiwalled carbon nanotubes (CNTs) in vacuum. The sustained incandescence originated from radiative dissipation of heated CNTs due to laser-CNT interactions. Sustainability of the LII up to 2 h was achieved. Fittings of the LII intensity spectrum with Planck blackbody distribution indicate a rise of temperature from room temperature to {approx}2500 K in less than 0.1 s. This provides an effective way of achieving rapid high temperature heating at specific localized positions within CNT arrays.

Lim, Z.H.; Sow, C.-H. [Department of Physics, Faculty of Science, National University of Singapore, Singapore S117542 (Singapore); National University of Singapore Nanoscience and Nanotechnology Initiative, National University of Singapore, Singapore S117542 (Singapore); Lee, Andrielle; Zhu Yanwu [Department of Physics, Faculty of Science, National University of Singapore, Singapore S117542 (Singapore); Lim, Kim-Yong [NUS High School of Mathematics and Science, 20 Clementi Avenue 1, Singapore S129957 (Singapore)

2009-02-16

154

Computer-based areal surface temperature and local heat transfer measurements with thermochromic liquid crystals (TLC)  

NASA Astrophysics Data System (ADS)

The experimental technique presented is designed to obtain detailed local heat transfer data on both stationary as well as rotating disk-cavity surfaces applicable to gas turbines. The method employed utilizes thin coatings of thermochromic liquid crystals (TLC) as surface temperature indicators under aerodynamically steady but thermally transient experimental conditions. The color display of the liquid crystals is monitored by a video camera. The video signals are captured in real time by a computer-based color recognition system to extract areal temperature and heat transfer information. Some typical results are presented and compared with literature data to illustrate the potential of the system.

Platzer, K.-H.; Hirsch, C.; Metzger, D. E.; Wittig, S.

1992-05-01

155

Selective domain wall depinning by localized Oersted fields and Joule heating  

NASA Astrophysics Data System (ADS)

Using low temperature magnetoresistance measurements, the possibility to selectively move a domain wall locally by applying current pulses through a Au nanowire adjacent to a permalloy element is studied. We find that the domain wall depinning field is drastically modified with increasing current density due to the Joule heating and the Oersted field of the current, and controlled motion due to the Oersted field without any externally applied fields is achieved. By placing the domain wall at various distances from the Au wire, we determine the range of the Joule heating and the Oersted field and both effects can be separated.

Ilgaz, Dennis; Kläui, Mathias; Heyne, Lutz; Boulle, Olivier; Zinser, Fabian; Krzyk, Stephen; Fonin, Mikhail; Rüdiger, Ulrich; Backes, Dirk; Heyderman, Laura J.

2008-09-01

156

Laser production and heating of plasma for MHD application  

NASA Technical Reports Server (NTRS)

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.

Jalufka, N. W.

1988-01-01

157

Laser production and heating of plasma for MHD application  

SciTech Connect

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.

Jalufka, N.W.

1988-03-01

158

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)

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.

Liebermeister, C.

1978-01-01

159

Optical investigation of heat release and NOx production in combustion  

NASA Astrophysics Data System (ADS)

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.

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

2005-08-01

160

Optical investigation of heat release and NOx production in combustion  

NASA Astrophysics Data System (ADS)

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.

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

2007-10-01

161

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

PubMed Central

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 42°C 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.

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

2013-01-01

162

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

PubMed

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 42°C 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

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

2013-01-01

163

An improved local radial point interpolation method for transient heat conduction analysis  

NASA Astrophysics Data System (ADS)

The smoothing thin plate spline (STPS) interpolation using the penalty function method according to the optimization theory is presented to deal with transient heat conduction problems. The smooth conditions of the shape functions and derivatives can be satisfied so that the distortions hardly occur. Local weak forms are developed using the weighted residual method locally from the partial differential equations of the transient heat conduction. Here the Heaviside step function is used as the test function in each sub-domain to avoid the need for a domain integral. Essential boundary conditions can be implemented like the finite element method (FEM) as the shape functions possess the Kronecker delta property. The traditional two-point difference method is selected for the time discretization scheme. Three selected numerical examples are presented in this paper to demonstrate the availability and accuracy of the present approach comparing with the traditional thin plate spline (TPS) radial basis functions.

Wang, Feng; Lin, Gao; Zheng, Bao-Jing; Hu, Zhi-Qiang

2013-06-01

164

Differential Heat Shock Tolerance and Expression of Heat-Inducible Proteins in Two Stored-Product Psocids  

Microsoft Academic Search

The recent recognition of psocids as a major concern in stored products and also the reemergence of heat treatment as a control tactic of stored-product insects led to the present investigation. The objectives of this study were to determine whether there are differences in heat shock tolerance of two species of stored-product psocidsÑLepinotusreticulatus Enderlein (Trogiidae) and Liposcelis entomophila (Enderlein) (Liposcelididae)Ñand

R. N. C. GUEDES; K. Y. Zhu; G. P. Opit; J. E. Throne

2008-01-01

165

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

SciTech Connect

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.

Lyneis, C.; Leitner, D.; Todd, D.; Virostek, S.; Loew, T.; Heinen, A.; Tarvainen, O. [Lawrence Berkeley National Laboratory, One Cyclotron Road, Berkeley, California 94720 (United States); Institute of Nuclear Physics, Wilhelm-Klemm-Strasse, 9, D-48149, Muenster (Germany); Department of Physics (JYFL), FI-40014, University of Jyvaeskylae, Jyvaeskylae (Finland)

2006-03-15

166

Characterization of Heat Melt Compactor (HMC) Product Water  

NASA Technical Reports Server (NTRS)

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.

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

2013-01-01

167

Local Measurement of Non-Classical Ion Heating During Magnetic Reconnection  

SciTech Connect

Local ion temperature is measured directly in the well-characterized reconnection layer of a laboratory plasma. These measurements demonstrate definitively that ions are heated due to reconnection and that more than half of the reconnected field energy is converted to ion kinetic energy. Neither classical Ohmic dissipation nor thermalization of energetic flows is sufficient to account for the energy converted, suggesting the importance of non-classical dissipation mechanisms such as wave-particle interactions.

G. Fiskel; H. Ji; M. Yamada; R.M. Kulsrud; S.C. Hsu; T.A. Carter

1999-11-01

168

Localized electron-cyclotron heating and current drive in the TIBER-II reactor study  

SciTech Connect

A scenario is shown for launching 10 MW of 450 GHz extraordinary-mode electron-cyclotron waves into a TIBER-II equilibrium. Localized, high-efficiency current drive near but outside the q = 2 surface causes substantial reduction in the current gradients that may play a role in major disruptions and anomalous transport. The same launch geometry shows promise for heating the plasma core during startup.

Smith, G.R.; Logan, B.G.; Kritz, A.H.

1987-05-01

169

Stress-strain state of the cylindrical shell of a pressure vessel with local heating  

Microsoft Academic Search

Results of calculated and experimental investigations of the stress-strain state of a cylindrical shell subjected to local heating are presented. The solution is obtained by expanding the internal forces into a Fourier series for the circumferential coordinate of the shell. The method of full-scale high-temperature tensometry was used for the experimental investigations. Experimental data and calculation results are compared.

V. N. Mukhin; A. I. Tarovatov; É. I. Él'manovich

1990-01-01

170

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

SciTech Connect

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.

Pechersky, M.J.; Miller, R.F. [Westinghouse Savannah River Company, SC (United States); Vikram, C.S. [University of Alabama, AL (United States)

1994-01-06

171

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

PubMed

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

Chen, Youping

2006-02-01

172

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

NASA Astrophysics Data System (ADS)

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.

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

2011-03-01

173

Safety of localizing epilepsy monitoring intracranial electroencephalograph electrodes using MRI: Radiofrequency-induced heating  

PubMed Central

Purpose To investigate heating during postimplantation localization of intracranial electroencephalograph (EEG) electrodes by MRI. Materials and Methods A phantom patient with a realistic arrangement of electrodes was used to simulate tissue heating during MRI. Measurements were performed using 1.5 Tesla (T) and 3T MRI scanners, using head- and body-transmit RF-coils. Two electrode-lead configurations were assessed: a “standard” condition with external electrode-leads physically separated and a “fault” condition with all lead terminations electrically shorted. Results Using a head-transmit–receive coil and a 2.4 W/kg head-average specific absorption rate (SAR) sequence, at 1.5T the maximum temperature change remained within safe limits (<1°C). Under “standard” conditions, we observed greater heating (?2.0°C) at 3T on one system and similar heating (<1°C) on a second, compared with the 1.5T system. In all cases these temperature maxima occurred at the grid electrode. In the “fault” condition, larger temperature increases were observed at both field strengths, particularly for the depth electrodes. Conversely, with a body-transmit coil at 3T significant heating (+6.4°C) was observed (same sequence, 1.2/0.5 W/kg head/body-average) at the grid electrode under “standard” conditions, substantially exceeding safe limits. These temperature increases neglect perfusion, a major source of heat dissipation in vivo. Conclusion MRI for intracranial electrode localization can be performed safely at both 1.5T and 3T provided a head-transmit coil is used, electrode leads are separated, and scanner-reported SARs are limited as determined in advance for specific scanner models, RF coils and implant arrangements. Neglecting these restrictions may result in tissue injury. J. Magn. Reson. Imaging 2008;28:1233–1244. © 2008 Wiley-Liss, Inc.

Carmichael, David W; Thornton, John S; Rodionov, Roman; Thornton, Rachel; McEvoy, Andrew; Allen, Philip J; Lemieux, Louis

2008-01-01

174

A transient 3-D inverse problem in imaging the time-dependent local heat transfer coefficients for plate fin  

Microsoft Academic Search

The local time-dependent surface heat transfer coefficients for plate finned-tube heat exchangers are estimated in a three-dimensional inverse heat conduction problem. The inverse algorithm utilizing the steepest descent method (SDM) and a general purpose commercial code CFX4.4 is applied successfully in this study in accordance with the simulated measured temperature distributions on fin surface by infrared thermography. Two different heat

Cheng-Hung Huang; Yao-Long Tsai

2005-01-01

175

Heat production and heat flow in the mantle lithosphere, Slave craton, Canada  

NASA Astrophysics Data System (ADS)

Thermobarometric data for mantle xenoliths from a kimberlite pipe in the NWT, Canada are used to constrain the thermal properties of the lithospheric mantle underlying the Slave craton. We derive an analytical expression for a steady-state conductive mantle geotherm that is independent of the geometry and thermal properties of the crust. The model has an upper boundary coincident with the MOHO at a depth Zm and has temperature Tm and heat flow qm. The mantle is assumed to have constant radiogenic heat production ( A) and we allow for a temperature-dependent thermal conductivity [ K( T)= Ko(1+ B( T- Tm))]. Inverting the thermobarometric data through the model geotherm gives limiting values for mantle heat production ( A) and bounds on the temperature dependence of K (e.g. B) that are consistent with the mantle P- T array. We characterize the Slave lithospheric mantle in terms of three critical parameters qm (mW m -2), A (?W m -3), Tm (°C). The optimal solution has values [15.1, 0.012, 455]. This characterization of thermal state of the Slave mantle is based mainly on petrological data and is not biased by assumptions about crustal thermal properties. Our analysis shows that a substantial range of parameter values can be used to describe the data accurately and the two bounding solutions are [24.2, 0.088, 296] and [12.3, 0, 534], respectively. However, model parameters are strongly correlated and this precludes the arbitrary selection of values of [ qm, A, Tm] from these ranges.

Russell, James K.; Dipple, G. M.; Kopylova, M. G.

2001-03-01

176

Simplified model for determining local heat flux boundary conditions for slagging wall  

SciTech Connect

In this work, two models for calculating heat transfer through a cooled vertical wall covered with a running slag layer are investigated. The first one relies on a discretization of the velocity equation, and the second one relies on an analytical solution. The aim is to find a model that can be used for calculating local heat flux boundary conditions in computational fluid dynamics (CFD) analysis of such processes. Two different cases where molten deposits exist are investigated: the black liquor recovery boiler and the coal gasifier. The results show that a model relying on discretization of the velocity equation is more flexible in handling different temperature-viscosity relations. Nevertheless, a model relying on an analytical solution is the one fast enough for a potential use as a CFD submodel. Furthermore, the influence of simplifications to the heat balance in the model is investigated. It is found that simplification of the heat balance can be applied when the radiation heat flux is dominant in the balance. 9 refs., 7 figs., 10 tabs.

Bingzhi Li; Anders Brink; Mikko Hupa [Aabo Akademi University, Turku (Finland). Process Chemistry Centre

2009-07-15

177

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

PubMed Central

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.

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

2012-01-01

178

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

ERIC Educational Resources Information Center

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…

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

2009-01-01

179

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

SciTech Connect

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.

Dr. Ronald D. Boyd

2000-07-01

180

Effect of model orientation and wall heating condition on local heat transfer in a rotating two-pass square channel with rib turbulators  

Microsoft Academic Search

The influences of channel orientation and wall heating condition on the local surface heat transfer coefficient in a rotating, two-pass, square channel with 60° and 90° ribs on the leading and trailing walls were investigated for Reynolds numbers from 2500 to 25 000 and rotation numbers from 0 to 0.352. The two channel orientations were (1) square channel perpendicular to

James A. Parsons; Je-Chin Han; Yuming Zhang

1995-01-01

181

Experimental investigation of the local heat transfer in a vertical gas-liquid slug unit  

NASA Astrophysics Data System (ADS)

Heat transfer mechanism in two-phase flows and particularly in vertical slug flow is of high interest both for basic hydrodynamic research and for industrial applications. Two-phase slug flow is highly complicated and only a limited number of heat transfer studies have been carried out. The flow field around a single Taylor bubble propagating in a vertical pipe can be subdivided into three distinct hydrodynamic regions: the gas bubble surrounded by a thin liquid film, a highly turbulent liquid wake in the vicinity of the bubble bottom, and the far wake region. Experimental and theoretical works were presented during the last decades investigating the hydrodynamic parameters in each region. Due to the complexity and intermittent nature of slug flow the existing data on the heat transfer in slug flow is limited to a narrow range of operational conditions. To improve the understanding of the heat transfer mechanism in slug flow a new experimental setup was constructed. A part of the vertical pipe wall was replaced by a thin metal foil heated by electrical current. An IR video camera was used to determine the temporal variation of the instantaneous temperature field along the foil at two locations: at the thermal entrance region and at the upper part of the foil where thermal boundary is thicker. The video camera was synchronized with a sensor that determined the instantaneous location of the Taylor bubble. The results of the instantaneous heat transfer measurements along the liquid film and in the wake of the Taylor bubble can be correlated with the detailed velocity measurements carried out in the same facility (Shemer et al. 2007)[1]. The effect of the local hydrodynamic parameters on the heat transfer coefficient in each region is examined.

Babin, Valery; Shemer, Lev; Barnea, Dvora

2012-03-01

182

Influence of coastal polynyas on heat flux and sea ice production in the southwestern Weddell Sea  

NASA Astrophysics Data System (ADS)

A coastal polynya occurs where off-shore winds cause the sea ice to drift away from the coastline. The reduced or removed ice cover allows an almost unobstructed ocean-atmosphere heat exchange and in the winter months very high ice production rates are induced. Therefore, coastal polynyas are often referred to as 'ice factories'. With the Finite Element Sea ice-Ocean Model (FESOM) we investigate the coastal polynyas in the southwestern Weddell Sea. The combination of a primitive-equation, hydrostatic ocean model and a dynamic-thermodynamic sea ice model was set up with a global, unstructured grid that features a horizontal resolution of up to 3 km along the southwestern Weddell Sea coastline. The 37 depth levels have increased resolution toward the surface. The model was initialized on 01/01/1980 with data from the Polar Hydrographic Climatology and the boundary conditions were supplied by the NCEP/NCAR Reanalysis. Our analysis of the period 1990-2009 indicates that in an average winter season coastal polynyas cover an area of 9000 km2 and facilitate an ocean-to-atmosphere heat transport of 370 W/m2, which splits into about 61% of sensible heat, 24% latent heat, 16% longwave radiation and -1.5% shortwave radiation. The ocean provides 50 W/m2 by cooling the water column, the rest is supplied from latent heat released in the process of 9 cm/d ice production (accumulating to 1?1011 m3/season). Interannual variability, however, is high. An evaluation of additional simulations with three higher-resolution atmospheric forcing dataset, including two regional configurations of the COSMO atmosphere model, yields local differences but robustness and consistency on a larger scale.

Haid, Verena; Timmermann, Ralph; Ebner, Lars; Heinemann, Guenther

2013-04-01

183

Local and transient structural changes in stratum corneum at high electric fields: contribution of Joule heating.  

PubMed

Electroporation of skin is accompanied by local heating, such that thermally induced structural changes of the stratum corneum (SC) accompany the field effect. Comparing on the time scale, the local changes in structure, temperature and conductance of the SC, during and after the pulse, it is seen that Joule heating also facilitates the subsequent molecular transport. It is found that the transport of medium-sized, ionic molecules occurs through localized transport regions (LTR). The size of a LTR increases with the pulse length, whereas the density of the LTRs increases with increasing voltage, for instance at U(SC=)80 V, the LTR cover approximately 0.02--1% of the surface area. The state of low resistance within the LTR is long-lived. During high voltage application, the center of the LTR is heated above the phase transition temperature of the SC lipids (70 degrees C) and the heat front propagates outwards. Inside the SC, the pulse causes aggregates of small-sized vesicles. At a higher temperature, the aggregate formation and their disappearance are delayed. Multiple pulses with the applied voltage of U(appl)=80 V induce the formation of long-lasting vesicle aggregates with a diameter of slashed circle=1--30 microm, covering 0.05--0.5% of the total sample area. The electric energy dissipated within the LTR during high voltage application is apparently sufficient to raise the temperature well above the phase transition temperature of the lipids of the SC, accounting for the conformational changes from the multi-lamella to the vesicular structures. PMID:15967399

Pliquett, U; Gallo, S; Hui, S W; Gusbeth, Ch; Neumann, E

2005-09-01

184

Production of multicharged iron ions with inductively heated vapor source  

SciTech Connect

Multiply charged Fe ions are produced from solid material in a 2.45 GHz electron cyclotron resonance (ECR) ion source. We develop an evaporator by induction heating with an induction coil covered by ceramics in vacuum and surrounding the pure Fe rod with noncontact. The typical power and the frequency of the induction currents range from 300 to 800 W and from 30 to 40 kHz, respectively. The evaporator is inserted into the ECR plasma from the mirror endplate along the geometrical axis of the mirror field. Argon gas is usually chosen for supporting gas, and the working pressure is about 10{sup -4}-10{sup -3} Pa. The multicharged Fe ions are extracted from the opposite side of mirror and against the evaporator, and then multicharged Fe ion beam is formed. We compare the production of multicharged iron ions by using this source with our previous methods.

Kato, Yushi; Tomida, Masashi; Kubo, Takashi; Asaji, Toyohisa; Tanaka, Kiyokatsu; Sato, Fuminobu; Iida, Toshiyuki [Department of Electrical, Electronic and Information Engineering, Graduate School of Engineering, Osaka Univ. 2-1 Yamada-oka, Suita-shi, Osaka 565-0871 (Japan); Department of Electronics and Informatics, Toyama Pref. Univ. 5180 Kosugikurokawa, Imizu, Toyama 939-0398 (Japan); Department of Electrical, Electronic and Information Engineering, Graduate School of Engineering, Osaka Univ. 2-1 Yamada-oka, Suita-shi, Osaka 565-0871 (Japan); Department of Electrical, Electronic and Information Engineering, Graduate School of Engineering, Osaka Univ. 2-1 Yamada-oka, Suita-shi, Osaka 565-0871 (Japan); Tateyama Machine Co., Ltd., Tateyama Kagaku Group, 30 Shimonoban, Toyama 930-1305 (Japan); Tateyama Machine Co., Ltd., Tateyama Kagaku Group, 30 Shimonoban, Toyama 930-1305 (Japan); Department of Electrical, Electronic and Information Engineering, Graduate School of Engineering, Osaka Univ. 2-1 Yamada-oka, Suita-shi, Osaka 565-0871 (Japan)

2006-03-15

185

A Fresnel collector process heat experiment at Capitol Concrete Products  

NASA Technical Reports Server (NTRS)

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.

Hauger, J. S.

1981-01-01

186

Drucklufterzeugung MIT Abwaermenutzung in Industriebetrieben (Compressed Air Production with Waste Heat Utilization in Industry).  

National Technical Information Service (NTIS)

The centralized power-heat coupling (PHC) technique using block heating power stations, is presented. Compressed air production in PHC technique with internal combustion engine drive achieves a high degree of primary energy utilization. Cost savings of 50...

E. Nolting

1984-01-01

187

Discontinuities in the specific heat of magnesium and associated latent heat at pressure-induced structural phase transitions using a local first principles pseudopotential  

Microsoft Academic Search

After a successful application of a local first principles pseudopotential to the study of the structural pressure-induced phase transition for magnesium, I now use the same local first principles type of pseudopotential, to study the specific heat as function of the pressure, at 300 K, in the region around the predicted phase transitions. I found that the specific presents two

Gregorio Ruiz Chavarría

2007-01-01

188

Local heating of ZnO due to the surface plasmon excitation of Au nanoparticles  

NASA Astrophysics Data System (ADS)

Temperature dependent E2(high) Raman active optical phonon mode was investigated to identify the local heating of the ZnO, due to the surface plasmon excitation of the Au nanoparticles. The variation of the linewidth (FWHM) of E2(high) mode for ZnO was investigated from room temperature to 450 ^oC with 25 ^oC steps under constant 532 nm laser excitation intensity of 2.6*10^5 W/m^2. Linewidth (FWHM) was increased with the temperature and it was fitted into the theoretical model originally developed by Menendez et al, which contains both cubic and quadratic anharmonicities. After optimizing the cubic and quadratic anharmonic coupling constants, the fit was used to estimate the local temperatures of Au/ZnO, which were irradiated with different laser intensities. The estimated local temperature for Au/ZnO was 613 ^oC at the laser intensity of 8.1*10^5 W/m^2. ZnO without Au nanoparticles didn't show any large temperature variation under the different laser intensities. This is a clear evidence for the heat generation of Au nanoparticles due to the surface plasmon excitation.

Ranasingha, Oshadha; Wang, Congjun; Lewis, James P.; Matranga, Christopher

2013-03-01

189

Spectral non-uniform temperature and non-local heat transfer in the spin Seebeck effect.  

PubMed

Recently discovered spin-dependent thermoelectric effects have merged spin, charge, and thermal physics, known as spin caloritronics, of which the spin Seebeck effect is its most puzzling. Here we present a theory of this effect driven by subthermal non-local phonon heat transfer and spectral non-uniform temperature. The theory explains its non-local behaviour from the fact that phonons that store the energy (thermal) and the phonons that transfer it (subthermal) are located in different parts of the spectrum and have different kinetics. This gives rise to a spectral phonon distribution that deviates from local equilibrium along the substrate and is sensitive to boundary conditions. The theory also predicts a non-magnon origin of the effect in ferromagnetic metals in agreement with observations in recent experiments. Equilibration of the heat flow from the substrate to the Pt probe and backwards leads to a vertical spin current produced by the spin-polarized electrons dragged by the thermal phonons. PMID:23735931

Tikhonov, Konstantin S; Sinova, Jairo; Finkel'stein, Alexander M

2013-01-01

190

Formation of Maillard reaction products during heat treatment of carrots.  

PubMed

As indicators of the early stage of the Maillard reaction in carrots, N-(furoylmethyl) amino acids (FMAAs) formed during acid hydrolysis of the corresponding Amadori products were analyzed using RP-HPLC with UV detection. N(?)-FM-Lys (furosine), FM-Gly, FM-Ala, FM-Val, FM-Ile, FM-Leu, and FM-GABA were identified using synthesized standard material by means of mass spectrometry. Furthermore, N(?)-carboxymethyllysine (CML) and pyrraline were analyzed as indicators for advanced stages of glycation. For commercial samples with high water content, the formation of Amadori compounds predominates, whereas the advanced stage of Maillard reaction plays only a minor part. Carrot juices, baby food, and tinned carrots showed quite low rates of amino acid modification up to 5%. For dehydrated carrots, significantly higher values for Amadori products were measured, corresponding to a lysine derivatization of up to 58% and nearly 100% derivatization of GABA. Drying experiments revealed great differences in reactivity between the amino acids studied. Whereas furosine reached constant values quite quickly, some FMAAs showed a continuous increase with heating time, indicating that selected FMAAs can be used as a hallmark for the early Maillard reaction to control processing conditions. PMID:21682346

Wellner, Anne; Huettl, Christine; Henle, Thomas

2011-07-27

191

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

SciTech Connect

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.

Colvin, Jeffrey; Shestakov, Aleksei; Stoelken, James; Vignes, Ryan [Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, CA 94551 (United States)

2011-03-01

192

Thermal convection with large viscosity variation in an enclosure with localized heating  

SciTech Connect

The present study is undertaken in order to gain an understanding of convective transport in a magma chamber. We have chosen to represent the chamber by an enclosure with localized heating from below. Results of both laboratory experiments and computer modeling are reported. The experimental apparatus consists of a transparent enclosure with a square planform. An electrically heated strip, with a width equal to one-fourth of the length of a side of the enclosure, is centered on the lower inside surface of the enclosure. For the experiments reported here, the top of the fluid layer is maintained at a constant temperature and the depth of the layer is equal to the width of the heated strip. The large viscosity variation characteristic of magma convection is simulated by using corn syrup as the working fluid. Measured velocity and temperature distribution as well as overall heat transfer rates are presented. The experiment is numerically simulated through use of a finite element computer program. Numerically predicted streamlines, isotherms, and velocity distributions are presented for the transverse vertical midplane of the enclosure. Good agreement is demonstrated between predictions and measurements. 23 refs., 8 figs., 2 tabs.

Chu, T.Y.; Hickox, C.E.

1988-01-01

193

A Low Molecular Mass Heat-Shock Protein Is Localized to Higher Plant Mitochondria.  

PubMed Central

When pea (Pisum sativum L. var Douce Provence) plants are shifted from a normal growth temperature of 25[deg] C up to 40[deg] C for 3 h, a novel 22-kD protein is produced and accumulates in the matrix compartment of green leaf mitochondria. HSP22 was purified and used as antigen to prepare guinea pig antiserum. The expression of HSP22 was studied using immunodetection methods. HSP22 is a nuclear-encoded protein de novo synthesized in heat-stressed pea plants. The heat-shock response is rapid and can be detected as early as 30 min after the temperature is raised. On the other hand, HSP22 declines very slowly after pea leaves have been transferred back to 25[deg] C. After 100 h at 25[deg] C, the heat-shock pattern was undetectable. The precise localization of HSP22 was investigated and we demonstrated that HSP22 was found only in mitochondria, where it represents 1 to 2% of total matrix proteins. However, the induction of HSP22 does not seem to be tissue specific, since the protein was detected in green or etiolated pea leaves as well as in pea roots. Finally, examination of matrix extracts by nondenaturing polyacrylamide gel electrophoresis and immunoblotting with anti-HSP22 serum revealed a high-molecular mass heat-shock protein complex of 230 kD, which contains HSP22.

Lenne, C.; Douce, R.

1994-01-01

194

Dehydrating of flax fiber with microwave heating for biocomposite production.  

PubMed

The feasibility of microwave dehydrating flax fiber was evaluated using a commercial domestic microwave oven at four power settings representing 200, 300, 400 and 500 Watt (W) power level. Due to the possibility of local heating and consequent fiber degradation, the changes in color of the flax fiber at different levels of temperature were also investigated. The dehydration processes at various power levels were simulated by Page model. Based on visual inspection, color analysis and scanning electron microscopy (SEM) of the fiber, it was revealed that discoloration of the fiber occurred at about 170 degrees C. At 200 and 300 W power level, after 10 minutes of dehydrating, the moisture content of the fiber reached from initial 7.9% close to 2.0 and 1.0%, respectively. For 400 W power level, the moisture content of the fiber dropped to 0. 10% in about 9.5 minutes. Major discoloration of the fiber was noticed when dehydration was proceed beyond 4.5 minutes for 500 W treatment. The Page model very well fitted the experimental data. The coefficients of determination calculated from the model and the experimental data increased with increase in applied microwave power PMID:17278791

Panigrahi, Satyanarayan; Ghazanfari, Ahmad; Meda, Venkatesh

2006-01-01

195

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

SciTech Connect

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.

Lara-Curzio, Edgar [ORNL] [ORNL; May, Andrew F [ORNL] [ORNL; Delaire, Olivier A [ORNL] [ORNL; McGuire, Michael A [ORNL] [ORNL; Lu, Xu [Michigan State University] [Michigan State University; Li, Cheng-Yun [Michigan State University] [Michigan State University; Case, Eldon D [Michigan State University, East Lansing] [Michigan State University, East Lansing; Morelli, Donold [Michigan State University, East Lansing] [Michigan State University, East Lansing

2014-01-01

196

Stability of symmetric vortex flow over slender bodies and possibility of control by local gas heating  

NASA Astrophysics Data System (ADS)

Stability properties of vortex structure over slender bodies at high angles of attack and instability mechanism are the subjects of many experimental and computational studies, most of which are observed in [1, 2]. However, the reasons and mechanism of spontaneous symmetric flow breaking are not established up to now. In the first part of the present paper, a criterion for asymmetry origin for slender conical bodies is obtained using slender body theory [3] and catastrophe theory [4]. The theoretical results are verified by comparison with experimental data [5-8]; they helped to explain most of experimental observations and numerical simulations. In the second part, based on the obtained criterion and numerical solutions of boundary layer equations evaluations are made to estimate an effectiveness of global flow structure control method using local volumetric or surface gas heating. Qualitative confirmation of these estimations was done in experiments [7, 8] with gas heating by plasma discharge.

Shalaev, V. I.; Shalaev, I. V.

2013-06-01

197

Sawtooth stabilization by localized electron cyclotron heating in a tokamak plasma  

SciTech Connect

Sawtooth oscillations (STO) in the Ohmically heated WT-3 tokamak are strongly modified or suppressed by localized-electron cyclotron resonance heating (ECH) near the {ital q}=1 surface, where {ital q} refers to the safety factor. The efect of ECH is much stronger when it is applied on the high-field side as compared to the low-field side. Complete suppression of the STO is achieved for the duration of the ECH, in most cases, when it is applied on the high-field side of a low-density plasma, provided the ECH power exceeds a threshold 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 {ital q}=1 region.

Hanada, K.; Tanaka, H.; Iida, M.; Ide, S.; Minami, T.; Nakamura, M.; Maekawa, T.; Terumichi, Y.; Tanaka, S. (Department of Physics, Faculty of Science, Kyoto University, Kyoto, Japan (JP)); Yamada, M.; Manickam, J.; White, R.B. (Plasma Physics Laboratory, Princeton University, Princeton, New Jersey 08543 (USA))

1991-04-15

198

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

NASA Astrophysics Data System (ADS)

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 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.

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

2014-05-01

199

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

PubMed Central

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.

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

2013-01-01

200

A flexible RF applicator for heating viscous lossy products such as foods.  

PubMed

A helical RF industrial applicator was evaluated for heating minced meat flowing in a hollow tube. Heating was homogeneous inside the product, although the product was highly lossy due to its high electric conductivity. The homogeneity was much better than could be obtained with microwave heating. A high power density, up to 5 kW/liter, can be deposited inside the product with 95% efficiency. PMID:15038550

Roussy, G; Streiff, F; Moneuse, M

2001-01-01

201

Skin blood flow and local temperature independently modify sweat rate during passive heat stress in humans.  

PubMed

Sweat rate (SR) is reduced in locally cooled skin, which may result from decreased temperature and/or parallel reductions in skin blood flow. The purpose of this study was to test the hypotheses that decreased skin blood flow and decreased local temperature each independently attenuate sweating. In protocols I and II, eight subjects rested supine while wearing a water-perfused suit for the control of whole body skin and internal temperatures. While 34°C water perfused the suit, four microdialysis membranes were placed in posterior forearm skin not covered by the suit to manipulate skin blood flow using vasoactive agents. Each site was instrumented for control of local temperature and measurement of local SR (capacitance hygrometry) and skin blood flow (laser-Doppler flowmetry). In protocol I, two sites received norepinephrine to reduce skin blood flow, while two sites received Ringer solution (control). All sites were maintained at 34°C. In protocol II, all sites received 28 mM sodium nitroprusside to equalize skin blood flow between sites before local cooling to 20°C (2 sites) or maintenance at 34°C (2 sites). In both protocols, individuals were then passively heated to increase core temperature ~1°C. Both decreased skin blood flow and decreased local temperature attenuated the slope of the SR to mean body temperature relationship (2.0 ± 1.2 vs. 1.0 ± 0.7 mg·cm(-2)·min(-1)·°C(-1) for the effect of decreased skin blood flow, P = 0.01; 1.2 ± 0.9 vs. 0.07 ± 0.05 mg·cm(-2)·min(-1)·°C(-1) for the effect of decreased local temperature, P = 0.02). Furthermore, local cooling delayed the onset of sweating (mean body temperature of 37.5 ± 0.4 vs. 37.6 ± 0.4°C, P = 0.03). These data demonstrate that local cooling attenuates sweating by independent effects of decreased skin blood flow and decreased local skin temperature. PMID:20705945

Wingo, Jonathan E; Low, David A; Keller, David M; Brothers, R Matthew; Shibasaki, Manabu; Crandall, Craig G

2010-11-01

202

Use of a laser-induced fluorescence thermal imaging system for local jet impingement heat transfer measurement  

Microsoft Academic Search

In this paper the efficacy of a novel thermal imaging system designed for use in the study of local convective heat transfer is examined. The transient temperature measurements employed to calculate local heat transfer coefficients in this study rely on the temperature-sensitive fluorescence properties of a europium-doped lanthanum oxysulfide (La2O2S:Eu3+) thermographic phosphor. A series of temperature-time data sets acquired during

D. J. Bizzak; M. K. Chyu

1995-01-01

203

Analytical determination of local surface heat-transfer coefficients for cooled turbine blades from measured metal temperatures  

NASA Technical Reports Server (NTRS)

Analytical methods are presented for the determination of local values of outside and inside heat-transfer coefficients and effective gas temperatures by use of turbine-blade-temperature measurements. The methods are derived for a number of configurations that can be applied to typical cooled-turbine-blade shapes as well as to other types of heat-transfer apparatus.

Brown, W Byron; Esgar, Jack B

1950-01-01

204

Treatment of material discontinuity in two meshless local Petrov-Galerkin (MLPG) formulations of axisymmetric transient heat conduction  

Microsoft Academic Search

SUMMARY We use two meshless local Petrov-Galerkin (MLPG) formulations to analyse heat conduction in a bimetallic circular disk. The continuity of the normal component of the heat flux at the interface between two materials is satisfied either by the method of Lagrange multipliers or by using a jump function. The convergence of the H 0 and H 1 error norms

R. C. Batra; M. Porfiri; D. Spinello

2004-01-01

205

Turbulent Heat Fluxes in Urban Areas: Observations and a Local-Scale Urban Meteorological Parameterization Scheme (LUMPS)  

Microsoft Academic Search

A linked set of simple equations specifically designed to calculate heat fluxes for the urban environment is presented. This local-scale urban meteorological parameterization scheme (LUMPS), which has similarities to the hybrid plume dispersion model (HPDM) scheme, requires only standard meteorological observations and basic knowledge of surface cover. LUMPS is driven by net all-wave radiation. Heat storage by the urban fabric

C. S. B. Grimmond; T. R. Oke

2002-01-01

206

Application of the predicted heat strain model in development of localized, threshold-based heat stress management guidelines for the construction industry.  

PubMed

Existing heat stress risk management guidelines recommended by international standards are not practical for the construction industry which needs site supervision staff to make instant managerial decisions to mitigate heat risks. The ability of the predicted heat strain (PHS) model [ISO 7933 (2004). Ergonomics of the thermal environment analytical determination and interpretation of heat stress using calculation of the predicted heat strain. Geneva: International Standard Organisation] to predict maximum allowable exposure time (D lim) has now enabled development of localized, action-triggering and threshold-based guidelines for implementation by lay frontline staff on construction sites. This article presents a protocol for development of two heat stress management tools by applying the PHS model to its full potential. One of the tools is developed to facilitate managerial decisions on an optimized work-rest regimen for paced work. The other tool is developed to enable workers' self-regulation during self-paced work. PMID:24371045

Rowlinson, Steve; Jia, Yunyan Andrea

2014-04-01

207

Local Municipality Productive Efficiency and Its Determinants in South Africa  

Microsoft Academic Search

The paper assesses the technical efficiency of 231 local municipalities in South Africa for 2007 and investigates the potential determinants of efficiency gaps among local municipalities in the country using the nonparametric Data Envelopment Analysis (DEA) and the parametric Stochastic Frontier Analysis (SFA) techniques. In relation to the DEA technique, efficiency scores are subsequently explained in a second stage regression

Nara F. Monkam

2011-01-01

208

Constructing a model of 3D radiogenic heat production in Ireland  

NASA Astrophysics Data System (ADS)

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.

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

2012-04-01

209

Interfacing primary heat sources and cycles for thermochemical hydrogen production  

NASA Astrophysics Data System (ADS)

It is pointed out that an efficient utilization of heat from high-temperature heat sources in processes, which employ thermochemical cycles to obtain hydrogen from water, can be achieved only if the reaction temperatures and heat requirements of the cycle match the maximum temperature and heat delivery characteristics of the heat source. An investigation is, therefore, conducted regarding the criteria for ideal cycles in terms of their potential for practical adaptation to available heat sources. Attention is given to a method for selecting cycles for specific maximum temperatures in terms of thermodynamic criteria for 'ideal' cycles, the heat source characteristics, the direct decomposition of H2O and CO2, oxide decomposition cycles, sulfuric acid - metal sulfate cycles, alternate sulfate cycles, and low temperature cycles.

Bowman, M. G.

210

Clinical Performance of a Device That Applies Local Heat to the Insulin Infusion Site: A Crossover Study  

PubMed Central

Background Fast-acting insulin analogs have been available since 1996. The absorption rate of these insulins is still too slow to mimic the physiological insulin action in healthy subjects. This study investigates the clinical performance of InsuPatch™, a local skin-heating device, on postprandial glucose excursion. Methods Twenty-four type 1 diabetes mellitus subjects on continuous subcutaneous insulin infusion were included in this crossover study [10 male, 14 female, age: 43.5 ± 11.3 years, diabetes duration: 18.3 ± 10.5 years, glycosylated hemoglobin: 7.4 ± 0.8%, body mass index: 25.0 ± 3.0 kg/m² (mean ± standard deviation)]. The impact of local skin heating was measured by dividing the two-hour area under the curve by integration time (AUC/t120) for blood glucose (BG) above baseline after two standardized breakfast and dinner meal pairs (with and without heating) per subject. For the first breakfast pair, venous insulin concentration was also measured. Results A significant reduction was found for the AUC/t120 after breakfast and after dinner meals (42 breakfast meal pairs, AUC/t120 not heated 66.4 ± 32.8 mg/dl vs heated 56.8 ± 34.0 mg/dl, p = .017; 38 dinner meal pairs, AUC/t120 not heated 30.8 ± 31.0 mg/dl vs heated 18.4 ± 23.9 mg/dl, p = .0028). The maximum venous insulin concentration with heating was 27% higher than without heating (n = 23). The number of hypoglycemic events on days with heating (n = 9) was similar to the number of days without heating (n = 13). Conclusions Local heating of the skin around the infusion site significantly reduced postprandial BG by enhancing insulin absorption. The heating device was well tolerated, and it could facilitate development of closed-loop systems.

Freckmann, Guido; Pleus, Stefan; Westhoff, Antje; Krinelke, Lars G.; Buhr, Andreas; Jendrike, Nina; Haug, Cornelia

2012-01-01

211

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

NASA Astrophysics Data System (ADS)

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.

Barlow, Douglas N.

1994-08-01

212

Changes in dermal interstitial ATP levels during local heating of human skin.  

PubMed

Heating skin is believed to activate vanilloid type III and IV transient receptor potential ion channels (TRPV3, TRPV4, respectively), resulting in the release of ATP into the interstitial fluid. We examined the hypothesis that local skin heating would result in an accumulation of ATP in the interstitial fluid that would be related with a rise in skin blood flow (SkBF) and temperature sensation. Two microdialysis probes were inserted into the dermis on the dorsal aspect of the forearm in 15 young, healthy subjects. The probed skin was maintained at 31°C, 35°C, 39°C and 43°C for 8 min periods, during which SkBF was monitored as cutaneous vascular conductance (CVC). Dialysate was collected and analysed for ATP ([ATP](d)) using a luciferase-based assay, and ratings of perceived warmth were taken at each temperature. At a skin temperature of 31°C, [ATP](d) averaged 18.93 ± 4.06 nm and CVC averaged 12.57 ± 1.59% peak. Heating skin to 35°C resulted in an increase in CVC (17.63 ± 1.27% peak; P < 0.05), but no change in [ATP](d). Heating skin to 39°C and 43°C resulted in a decreased [ATP](d) (5.88 ± 1.68 nm and 8.75 ± 3.44 nm, respectively; P < 0.05), which was accompanied by significant elevations in CVC (38.90 ± 1.37% peak and 60.32 ± 1.95% peak, respectively; P < 0.05). Ratings of perceived warmth increased in proportion to the increase in skin temperature (r(2) = 0.75, P < 0.05). In conclusion, our data indicate that an accumulation of interstitial ATP does not occur during local heating, and therefore does not have a role in temperature sensation or the dilator response in human skin. Nevertheless, the low threshold of dilatation (35°C) indicates a possible role for the TRPV3, TRPV4 channels or the sensitization of other ion channels in mediating the dilator response. PMID:23045344

Gifford, Jayson R; Heal, Cory; Bridges, Jarom; Goldthorpe, Scott; Mack, Gary W

2012-12-15

213

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

SciTech Connect

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.

Windows and Daylighting Group

1997-12-08

214

Sustaining malaria prevention in Benin: local production of bednets.  

PubMed

Through a Benin-Canada participatory research initiative which included both Benin and Canadian non-governmental organizations, a local capacity to produce and market bednets for the prevention of malaria was developed. The development process began following a community-based assessment of local needs and skills. All materials for the manufacture and distribution of the bednets were obtained locally with the exception of the netting which was imported from Canada. The sustainability of the enterprise is enhanced by the community's recognition of the importance of malaria and the culturally acceptable practice of bednet use. PMID:10166104

Rashed, S; Johnson, H; Dongier, P; Gbaguidi, C C; Laleye, S; Tchobo, S; Gyorkos, T W; Maclean, J D; Moreau, R

1997-03-01

215

High-temperature strength of prealloyed-powder products increased by heat/pressure treatment  

NASA Technical Reports Server (NTRS)

Heat treatment process involves heating products to a temperature above the solidus, and subsequently applying pressure at a temperature below the solidus. Technique can be modified to one step process involving simultaneous application if both high pressure and heat. Process is not limited to cobalt-base alloys.

Ashbrook, R. L.; Freche, J. C.; Waters, W. J.

1971-01-01

216

Thermal histories of convective earth models and constraints on radiogenic heat production in the earth  

Microsoft Academic Search

Thermal histories have been calculated for simple models of the earth which assume that heat is transported by convection throughout the interior. The application of independent constraints to these solutions limits the acceptable range of the ratio of present radiogenic heat production in the earth to the present surface heat flux. The models use an empirical relation between the rate

Geoffrey F. Davies

1980-01-01

217

Climate change, workplace heat exposure, and occupational health and productivity in Central America.  

PubMed

Climate change is increasing heat exposure in places such as Central America, a tropical region with generally hot/humid conditions. Working people are at particular risk of heat stress because of the intrabody heat production caused by physical labor. This article aims to describe the risks of occupational heat exposure on health and productivity in Central America, and to make tentative estimates of the impact of ongoing climate change on these risks. A review of relevant literature and estimation of the heat exposure variable wet bulb globe temperature (WBGT) in different locations within the region were used to estimate the effects. We found that heat stress at work is a real threat. Literature from Central America and heat exposure estimates show that some workers are already at risk under current conditions. These conditions will likely worsen with climate change, demonstrating the need to create solutions that will protect worker health and productivity. PMID:21905396

Kjellstrom, Tord; Crowe, Jennifer

2011-01-01

218

The use of nickel/aluminum explosively reactive nanolayers as localized heat sources in solder joints  

NASA Astrophysics Data System (ADS)

Although solder reflow continues to be the current state of the art in joining technology, conventional reflow makes use of furnace heating, in which all components must be exposed to temperatures higher than the melting temperature of the solder. Damaging temperature sensitive components and thermal stresses involved in joining materials of different thermal expansion coefficients are critical drawbacks in using furnace heating. An alternative heat source is provided by Ni/Al reactive nanolayer foils, which is a material comprised of thousands of alternating, nanoscale layers of Al and Ni. A small pulse of energy in the form of an electric spark ignites the reaction by initiating interlayer atomic diffusion. The reaction between these layers is exothermic, releasing enough heat to allow the reaction to propagate through the remainder of the sample. Due to its shape and localized nature of heat released, solder can be melted without heating layers beyond the solder, such as temperature sensitive bond components. In this study, a process is developed to integrate Ni/Al reactive nanolayer foils into bond structures using materials in current technologies. Si/solder/Si and Cu/solder/Cu solder joints are fabricated by reactive nanolayer soldering and are used to study the microstructure and mechanical properties. The microstructural and chemical analysis are performed using scanning and transmission electron microscopy and as well as X-Ray diffraction and energy dispersive analysis, respectively. Single-lap shear testing, through-thickness tensile testing, in-situ nanocompression, and nanoindentation are used to characterize the mechanical strength. Ni/Al nanolayers become a single phase, nanocrystalline NiAl phase as a result of the explosive reaction. The wetting of Sn-based solders is good on this layer, as evidenced by the interlocking branched microstructure as well as the formation of Ni3Sn4 at the interface. A joint shear strength of approximately 30 MPa was yielded when the initial temperature was 70°C and the applied pressure was 15 MPa. In-situ nanocompression results show the direct observation of <110> slip and nanoindentation analysis showed that the NiAI layer has large compressive residual stress.

Tong, Michael Shou-Ming

219

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

NASA Astrophysics Data System (ADS)

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.

Mullen, Steven L.

1986-07-01

220

Local Heat and Mass Transfer in a Counter-current Slug Flow Absorber for Ammonia-water Absorption Heat Pump System  

NASA Astrophysics Data System (ADS)

This study deals with experimental results and data reduction model for a counter-current slug flow absorber working with ammonia-water mixture for significantly low solution flow rate-condition that is required for operating as the GAX cycle. From visualization results of flow pattern, frost flow just after the gas inlet followed by slug flow with well-shaped Taylor bubble are observed, while dry patch on the tube wall are not observed. The local heat flow rate is measured by varying main parameters, namely, pressure, ammonia gas flow rate, solution flow rate, ammonia concentration of inlet solution and coolant inlet conditions. A data reduction model to obtain local heat and mass transfer coefficient on the liquid side is proposed by using the drift flux model to analyze the flow characteristics. Control volume method and heat and mass transfer analogy are employed to solve the combined heat and mass transfer problem. As a result, it is found that the local heat and mass transfer coefficient on the liquid side is greatly influenced by the flow pattern. The heat and mass transfer coefficient at the frost flow region is higher than that at the slug flow region due to flow disturbance and random fluctuation.

Koyama, Shigeru; B. Saha, Bidyut; Kim, Hyun-Young

221

Localized Fast-Ion Induced Heat Loads in Test Blanket Module Mockup Experiments on DIII-D  

NASA Astrophysics Data System (ADS)

Localized hot spots can be created in ITER on the Test Blanket Modules (TBMs) because the ferritic steel of the TBMs distorts the local magnetic field near the modules and alters fast ion confinement. Predicting the TBM heat load levels is important for assessing their effects on the ITER first wall. Experiments in DIII-D were carried out with a mock-up of the ITER TBM ferromagnetic error field to provide data for validation of fast-ion orbit following codes. The front surface temperature of the protective TBM tiles was imaged directly with a calibrated infrared camera and heat loads were extracted. The detailed spot sizes and measured heat loads are compared with results from heat load calculations performed with a suite of orbit following codes. The codes reproduce the hot spots well, thereby validating the codes and giving confidence in predictions for fast-ion heat loads in ITER.

Kramer, G. J.; Budny, R. V.; Ellis, R. A.; Nazikian, R.; McLean, A. G.; Brooks, N. H.; Schaffer, M. J.; van Zeeland, M. A.; Heidbrink, W. W.; Kurki-Suonio, T.; Koskela, T.; Shinohara, K.; Snipes, J. A.; Spong, D. A.

2012-10-01

222

Nonmodal and nonlinear dynamics of a volatile liquid film flowing over a locally heated surface  

NASA Astrophysics Data System (ADS)

The stability of a thin, volatile liquid film falling under the influence of gravity over a locally heated, vertical plate is analyzed in the noninertial regime using a model based on long-wave theory. The model is formulated to account for evaporation that is either governed by thermodynamic considerations at the interface in the one-sided limit or limited by the rate of mass transfer of the vapor from the interface. The temperature gradient near the upstream edge of the heater induces a gradient in surface tension that opposes the gravity-driven flow, and a pronounced thermocapillary ridge develops in the streamwise direction. Recent theoretical analyses predict that the ridge becomes unstable above a critical value of the Marangoni parameter, leading to the experimentally observed rivulet structure that is periodic in the direction transverse to the bulk flow. An oscillatory, thermocapillary instability in the streamwise direction above the heater is also predicted for films with sufficiently large heat loss at the free surface due to either evaporation or strong convection in the adjoining gas. This present work extends the recent linear stability analysis of such flows by Tiwari and Davis [Phys. Fluids 21, 022105 (2009)] to a nonmodal analysis of the governing non-self-adjoint operator and computations of the nonlinear dynamics. The nonmodal analysis identifies the most destabilizing perturbations to the film and their maximum amplification. Computations of the nonlinear dynamics reveal that small perturbations can be sufficient to destabilize a linearly stable film for a narrow band of wave numbers predicted by the nonmodal, linearized analysis. This destabilization is linked to the presence of stable, discrete modes that appear as the Marangoni parameter approaches the critical value at which the film becomes linearly unstable. Furthermore, the thermocapillary instability leads to a new, time-periodic base state. This transition corresponds to a Hopf bifurcation with increasing Marangoni parameter. A linear stability analysis of this time-periodic state reveals further instability to transverse perturbations, with the wave number of the most unstable mode about 50% smaller than for the rivulet instability of the steady base state and exponential growth rate about three times larger. The resulting film behavior is reminiscent of inertial waves on locally heated films, although the wave amplitude is larger in the present case near the heater and decays downstream where the Marangoni stress vanishes. The film's heat transfer coefficient is found to increase significantly upon the transition to the time-periodic flow.

Tiwari, Naveen; Davis, Jeffrey M.

2009-10-01

223

Heat control for electric resistance welding in steel pipe production  

Microsoft Academic Search

A heat control system for electric resistance welding (ERW) for use in pipe manufacturing has been developed. The distinguishing features of the control system are: (1) use of a silicon photodiode array as a heat input sensor, (2) feedback control for steady welding, and (3) open-loop control for transient welding. This control system has been introduced into three ERW mills

I. Komine; I. Takahashi; S. Ishiro

1987-01-01

224

Stage-specific expression and cellular localization of the heat shock factor 2 isoforms in the rat seminiferous epithelium.  

PubMed

Heat shock transcription factors (HSFs) are generally known as regulators of cellular stress response. The mammalian HSF1 functions as a classical stress factor, whereas HSF2 is active during certain developmental processes, including embryogenesis and spermatogenesis. In the present study, we examined HSF2 expression at specific stages of the rat seminiferous epithelial cycle. We found that expression of the alternatively spliced HSF2-alpha and HSF2-beta isoforms is developmentally regulated in a stage-specific manner. Studies on cellular localization demonstrated that HSF2 is present in the nuclei of early pachytene spermatocytes at stages I-IV and in the nuclei of round spermatids at stages V-VIIab. In contrast a strong HSF2 immunoreactivity was detected in small distinct cytoplasmic regions from zygotene spermatocytes to maturation phase spermatids. Immunoelectron microscopic analysis revealed that these structures are mainly cytoplasmic bridges between germ cells. Our results on cellular localization of HSF2 and stage-specific expression of the HSF2 isoforms indicate that HSF2, in addition to its function as a nuclear transcription factor, may be involved in other cellular processes during spermatogenesis, possibly in the sharing process of gene products between the germ cells. PMID:9570917

Alastalo, T P; Lönnström, M; Leppä, S; Kaarniranta, K; Pelto-Huikko, M; Sistonen, L; Parvinen, M

1998-04-10

225

Radiogenic heat production in sedimentary rocks of the Gulf of Mexico Basin, south Texas  

USGS Publications Warehouse

Radiogenic heat production within the sedimentary section of the Gulf of Mexico basin is a significant source of heat. Radiogenic heat should be included in thermal models of this basin (and perhaps other sedimentary basins). We calculate that radiogenic heat may contribute up to 26% of the overall surface heat-flow density for an area in south Texas. Based on measurements of the radioactive decay rate of ??-particles, potassium concentration, and bulk density, we calculate radiogenic heat production for Stuart City (Lower Cretaceous) limestones, Wilcox (Eocene) sandstones and mudrocks, and Frio (Oligocene) sandstones and mudrocks from south Texas. Heat production rates range from a low of 0.07 ?? 0.01 ??W/m3 in clean Stuart City limestones to 2.21 ?? 0.24??W/m3 in Frio mudrocks. Mean heat production rates for Wilcox sandstones, Frio sandstones, Wilcox mudrocks, and Frio mudrocks are 0.88, 1.19, 1.50, and 1.72 ??W/m3, respectively. In general, the mudrocks produce about 30-40% more heat than stratigraphically equivalent sandstones. Frio rocks produce about 15% more heat than Wilcox rocks per unit volume of clastic rock (sandstone/mudrock). A one-dimensional heat-conduction model indicates that this radiogenic heat source has a significant effect on subsurface temperatures. If a thermal model were calibrated to observed temperatures by optimizing basal heat-flow density and ignoring sediment heat production, the extrapolated present-day temperature of a deeply buried source rock would be overestimated.Radiogenic heat production within the sedimentary section of the Gulf of Mexico basin is a significant source of heat. Radiogenic heat should be included in thermal models of this basin (and perhaps other sedimentary basins). We calculate that radiogenic heat may contribute up to 26% of the overall surface heat-flow density for an area in south Texas. Based on measurements of the radioactive decay rate of ??-particles, potassium concentration, and bulk density, we calculate radiogenic heat production for Stuart City (Lower Cretaceous) limestones, Wilcox (Eocene) sandstones and mudrocks, and Frio (Oligocene) sandstones and mudrocks from south Texas. Heat production rates range from a low of 0.07??0.01 ??W/m3 in clean Stuart City limestones to 2.21??0.24 ??W/m3 in Frio mudrocks. Mean heat production rates for Wilcox sandstones, Frio sandstones, Wilcox mudrocks, and Frio mudrocks are 0.88, 1.19, 1.50, and 1.72 ??W/m3, respectively. In general, the mudrocks produce about 30-40% more heat than stratigraphically equivalent sandstones. Frio rocks produce about 15% more heat than Wilcox rocks per unit volume of clastic rock (sandstone/mudrock). A one-dimensional heat-conduction model indicates that this radiogenic heat source has a significant effect on subsurface temperatures. If a thermal model were calibrated to observed temperatures by optimizing basal heat-flow density and ignoring sediment heat production, the extrapolated present-day temperature of a deeply buried source rock would be overestimated.

McKenna, T. E.; Sharp, Jr. , J. M.

1998-01-01

226

Experimental analysis of the local heat transfer coefficient of falling film evaporation with and without co-current air flow velocity  

NASA Astrophysics Data System (ADS)

This paper presents the experimental results of the local heat transfer for falling film evaporation of water sheet by solving the inverse heat conduction problem. It is shown that the local heat transfer coefficients increase by increasing the air flow velocity, the film liquid flow rate or decreasing the inlet bulk film temperature. Correlations for the mean heat transfer coefficients in the absence of superimposed flow for the stagnation region, the thermally developed region and the bottom of the heated cylinder are proposed.

Louahlia-Gualous, H.; Omari, L. El.; Panday, P. K.; Artioukhine, E.

2005-10-01

227

Kondo Signature in Heat Transfer via a Local Two-State System  

NASA Astrophysics Data System (ADS)

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 ?=(kB2TK/?)f(?,T/TK), where TK and ? indicate the Kondo temperature and dimensionless coupling strength, respectively. Temperature dependence of conductance is classified by the Kondo temperature as ??(T/TK)3 for T?TK and ??(kBT/??c)2?-1 for T?TK. Similarities to the Kondo signature in electric transport are discussed.

Saito, Keiji; Kato, Takeo

2013-11-01

228

Sawtooth stabilization by localized electron cyclotron heating in the WT-3 tokamak  

SciTech Connect

The effect on sawtooth oscillations (STO) by localized electron-cyclotron-resonance heating (ECH) on the WT-3 tokamak ({ital Plasma} {ital Physics} {ital and} {ital Controlled} {ital Nuclear} {ital Fusion} {ital Research}, 1988 (International Atomic Energy Agency, Vienna, 1989), Vol. 1, p. 563) is studied. STO are strongly modified or stabilized by ECH near the {ital q}=1 surface, where {ital q} refers to the safety factor. The effect of ECH is much stronger when it is applied on the high-field side as compared to the low-field side. Further, even when ECH is applied outside the {ital q}=1 surface, the amplitude of STO decreases and STO stabilizes. In the very high {ital q}{sub {ital L}} discharge, the excitation of STO can be obtained by applying ECH.

Hanada, K.; Maehara, T.; Makino, K.; Kishigami, Y.; Kishino, T.; Minami, T.; Tanaka, H.; Iida, M.; Nakamura, M.; Maekawa, T.; Terumichi, Y.; Tanaka, S. (Department of Physics, Kyoto University, Kyoto 606 (Japan))

1992-11-01

229

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

PubMed

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

Saito, Keiji; Kato, Takeo

2013-11-22

230

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

SciTech Connect

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.

Kaye, S.M.

1985-05-01

231

Diesel driven low capacity heat pump for heating and hot water production  

NASA Astrophysics Data System (ADS)

Heat pumps that reduce primary energy consumption for heating needs when they are driven by an internal combustion motor were studied. The heat produced as well from the heat pump as from the combustion in the diesel motor was used for home heating and hot water preparation. The objective was a 25kW capacity for a one familiy house. Material used should be standard, so a special design diesel motor or heat pump was not considered. An air/water cooled type diesel motor was coupled to a 12kW capacity heat pump for an outdoor temperature of 3 C using R12 freon as refrigerant. Description of all elements is given. Tests were in the laboratory and in a one family house. The expected efficiency factor of 1.34 could not be confirmed and an average annual value of only 1.05 is assumed. The diesel driven heat pump can not produce the energy savings hoped for.

Hoefler, P.

1982-08-01

232

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

NASA Astrophysics Data System (ADS)

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 1°C 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.

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

2014-03-01

233

Effects of heat-stress on production in dairy cattle.  

PubMed

The southeastern United States is characterized as humid subtropical and is subject to extended periods of high ambient temperature and relative humidity. Because the primary nonevaporative means of cooling for the cow (radiation, conduction, convection) become less effective with rising ambient temperature, the cow becomes increasingly reliant upon evaporative cooling in the form of sweating and panting. High relative humidity compromises evaporative cooling, so that under hot, humid conditions common to the Southeast in summer the dairy cow cannot dissipate sufficient body heat to prevent a rise in body temperature. Increasing air temperature, temperature-humidity index and rising rectal temperature above critical thresholds are related to decreased dry matter intake (DMI) and milk yield and to reduced efficiency of milk yield. Modifications including shade, barns which enhance passive ventilation, and the addition of fans and sprinklers increase body heat loss, lowering body temperature and improving DMI. New technologies including tunnel ventilation are being investigated to determine if they offer cooling advantages. Genetic selection for heat tolerance may be possible, but continued selection for greater performance in the absence of consideration for heat tolerance will result in greater susceptibility to heat stress. The nutritional needs of the cow change during heat stress, and ration reformulation to account for decreased DMI, the need to increase nutrient density, changing nutrient requirements, avoiding nutrient excesses and maintenance of normal rumen function is necessary. Maintaining cow performance in hot, humid climatic conditions in the future will likely require improved cooling capability, continued advances in nutritional formulation, and the need for genetic advancement which includes selection for heat tolerance or the identification of genetic traits which enhance heat tolerance. PMID:12836950

West, J W

2003-06-01

234

New industrial heat pump applications to cheese production  

SciTech Connect

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.

Not Available

1990-04-01

235

Suppression of local heat flux in a turbulent magnetized intracluster medium  

NASA Astrophysics Data System (ADS)

X-ray observations of hot gas in galaxy clusters often show steeper temperature gradients across cold fronts - contact discontinuities, driven by the differential gas motions. These sharp (a few kpc wide) surface brightness/temperature discontinuities would be quickly smeared out by the electron thermal conduction in unmagnetized plasma, suggesting significant suppression of the heat flow across the discontinuities. In fact, the character of the gas flow near cold fronts is favourable for suppression of conduction by aligning magnetic field lines along the discontinuities. We argue that a similar mechanism is operating in the bulk of the gas. Generic 3D random isotropic and incompressible motions increase the temperature gradients (in some places) and at the same time suppress the local conduction by aligning the magnetic field lines perpendicular to the local temperature gradient. We show that the suppression of the effective conductivity in the bulk of the gas can be linked to the increase of the frozen magnetic field energy density. On average the rate of decay of the temperature fluctuations d/dt decreases as -1/5.

Komarov, S. V.; Churazov, E. M.; Schekochihin, A. A.; ZuHone, J. A.

2014-05-01

236

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

ERIC Educational Resources Information Center

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…

Wilson, Geoff A.; Whitehead, Ian

2012-01-01

237

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

PubMed

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 ± 0.8°C 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

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

2012-05-01

238

Geoneutrinos and Heat Production in the Earth: Constraints and Implications  

ScienceCinema

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.

239

Geoneutrinos and Heat Production in the Earth: Constraints and Implications  

ScienceCinema

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.

240

Geoneutrinos and Heat Production in the Earth: Constraints and Implications  

ScienceCinema

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.

Bill McDonough

2010-01-08

241

Geoneutrinos and Heat Production in the Earth: Constraints and Implications  

SciTech Connect

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.

Bill McDonough

2008-07-02

242

Geoneutrinos and Heat Production in the Earth: Constraints and Implications  

SciTech Connect

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.

McConough, Bill (University of Maryland) [University of Maryland

2008-07-02

243

Efficient reconstruction of local heat fluxes in pool boiling experiments by goal-oriented adaptive mesh refinement  

NASA Astrophysics Data System (ADS)

In this paper, we consider the efficient estimation of local boiling heat fluxes from transient temperature measurements in the heater close to the heater surface. For accurate prediction, heat flux estimation is formulated as a transient three-dimensional (3D) inverse heat conduction problem (IHCP). This inverse problem is ill-posed and cannot be treated straightforwardly by established numerical methods. In order to obtain a regularized stable solution, a large-scale time-dependent PDE-constrained optimization problem has to be solved and an appropriate stopping criterion for the termination of the iterative solution process has to be chosen. Since the boiling heat flux is non-uniformly distributed on the heater surface due to the strong local activity of the boiling process, the use of a fixed uniform spatial discretization is not efficient. Instead, an adaptive mesh refinement strategy can be used to obtain an appropriate discretization which significantly reduces the total computational effort. In this work, we present an automatic algorithm incorporating an adaptive mesh refinement via a heat flux-based a-posteriori error estimation technique. The suggested algorithm can cope with both spatially point-wise or highly resolved temperature observations efficiently. It is applied to real measurement data obtained from two different types of pool boiling experiments. The numerical results show that the computational effort can be reduced significantly for given estimation quality. This adaptive IHCP solution technique can be also viewed as an efficient soft sensor to deduce unmeasurable local boiling heat fluxes.

Heng, Yi; Mhamdi, Adel; Marquardt, Wolfgang

2010-11-01

244

No evidence for the localized heating of solar wind protons at intense velocity shear zones  

NASA Astrophysics Data System (ADS)

measurements from the Wind spacecraft at 1 AU, the heating of protons in the solar wind at locations of intense velocity shear is examined. The 4321 sites of intense shear in fast coronal hole origin plasma are analyzed. The proton temperature, the proton specific entropy, and the proton number density at the locations of the shears are compared with the same quantities in the plasmas adjacent to the shears. A very slight but statistically significant enhancement of the proton temperature is seen at the sites of the shears, but it is accompanied by a larger enhancement of the proton number density at the sites of the shears. Consequently, there is no enhancement of the proton specific entropy at the shear sites, indicating no production of entropy; hence, no evidence for plasma heating is found at the sites of the velocity shears. Since the shearing velocities have appreciable Mach numbers, the authors suggest that there can be a slight adiabatic compression of the plasma at the shear zones.

Borovsky, Joseph E.; Steinberg, John T.

2014-03-01

245

Fermentor production of pectinases on gruel, a local by-product and their use in olive oil extraction  

Microsoft Academic Search

The CT1 mutant is a hyperproducer of pectinases isolated from Penicillium occitanis. It highly secretes pectinases on citrus pectin as well as on orange peel. Production in fermentor was carried out on another local by-product of wheat manufactories, the gruel. This substrate, poor in pectic substances, showed the highest capacity to induce pectinases, strengthening the fact that our mutant is

Noomen Hadj-Taieb; Malika Ayadi; Mohsen Khlif; Kamel Mrad; Ilem Hassairi; Ali Gargouri

2006-01-01

246

Immunocytochemical Localization of the Cystic Fibrosis Gene Product CFTR  

Microsoft Academic Search

Antisera against two peptides, corresponding to different domains of the cystic fibrosis gene product CFTR, have been raised and extensively characterized. Both antisera recognize CFTR as a 165-kDa polypeptide in Western analysis of cells transfected with CFTR cDNA as well as in epithelial cell lines. The cell and tissue distribution of CFTR has been studied by immunocytochemistry. CFTR is abundant

Isabelle Crawford; Peter C. Maloney; Pamela L. Zeitlin; William B. Guggino; Stephen C. Hyde; Helen Turley; Kevin C. Gatter; Ann Harris; Christopher F. Higgins

1991-01-01

247

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

PubMed Central

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.

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

2011-01-01

248

Global Surface Currents and Heat Transport: A New Product for Investigating Ocean Dynamics  

NASA Astrophysics Data System (ADS)

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.

Sudre, J.; Morrow, R.

2006-07-01

249

Ice-slurry production using direct contact heat transfer  

Microsoft Academic Search

An ice slurry generation system was developed using direct contact heat transfer between water and the coolant, Fluroinert FC-84. The location of the coolant nozzle is an important design consideration to avoid clogging due to freezing of water. An ice fraction of up to about 40 percent was obtained with the nozzle located at the bottom of the ice slurry

N. E. Wijeysundera; M. N. A. Hawlader; Chan Wee Boon Andy; M. Kamal Hossain

2004-01-01

250

Heat-inducible production of ?-glucuronidase in tobacco hairy root cultures  

Microsoft Academic Search

The production of ?-glucuronidase (GUS) driven by the Arabidopsis small heat shock protein 18.2 promoter in liquid cultures of transgenic tobacco (Nicotiana tabacum) hairy roots is reported. Clone GD-3, showing high GUS heat induction and a moderate growth rate, was selected from 436 clones\\u000a for study. Treatment of GD-3 with heat shock at 36–42C for 2 h then recovery at 27C

Kung-Ta Lee; Shih-Cheng Chen; Bor-Luen Chiang; Takashi Yamakawa

2007-01-01

251

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

PubMed

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

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

2010-01-01

252

Energy Production from Waste Heat by Means of Elastomers or Memory Metals.  

National Technical Information Service (NTIS)

The thermodynamic restrictions of the production of electric power from waste heat by means of memory metals or elastomers have been studied. Calculation of the energy of an ideal heat engine for a flow between waste water and cooling water has been made....

L. Ljung

1980-01-01

253

Nuclear power plant with closed gas-cooling circuit for production of process heat  

Microsoft Academic Search

A power plant is described which has a closed gas-cooling circuit for the production of process heat to be transferred to a secondary circuit. It consists of: (a) a vessel comprising a generally solid block of material; (b) a high-temperature reactor positioned within the vessel; (c) a plurality of heat exchanger units positioned about the reactor in the reactor in

Baumgaertner

1977-01-01

254

Composition stability and degradation products of selected materials for solar heating and cooling  

Microsoft Academic Search

The composition, stability and thermal degradation products of a variety of structural plastics, heat transfer fluids, thermal storage media and sealants, which have been proposed for use in solar heating and cooling applications, were either defined generically by analysis or obtained by surveying the literature. This information will be used to aid in the assessment of the environmental impact of

C. Arnold Jr.; R. E. Trujillo

1979-01-01

255

Pitch Angle Distribution Analysis from the CRRES MEA - Average Picture and Radial Diffusion versus Local Heating  

NASA Astrophysics Data System (ADS)

Variations in electron phasespace density at a particular location can be indicative of a specific energization or loss process. Determining the nature of that process as diffusive or local heating can be difficult to do. However, these processes can also leave different signatures on the pitch angle distributions (PADs) of a particle population, such that changes at a single location can give us important clues to the factors producing electron flux variations. Using data from the medium electron A instrument (MEA) on the CRRES satellite, a survey of PADs of energetic electrons is performed. The distributions are classified into three types (butterfly, 90-degree peaked, and flattop) based on the ratio of counts at 90 degrees and the average of the counts at 45 and 135 degrees. The categorizations are examined as a function of L-shell, localtime, orbit number and geomagnetic activity. The 90-degree peaked distributions tend to dominate on the dayside and in the lowest energy channel (153keV). Butterfly distributions are more prevalent at higher L-shells and on the nightside. During periods of moderate geomagnetic activity, we see an increase in butterfly distributions at L-shells greater than on the nightside and for 3.5 < L < 5.5 on the dayside. We also find significant differences in the average PAD before and after the great storm of March 24, 1991. Knowing the typical PAD types in a region, and the dependencies on other parameters, we can look for changes that might indicate a particular energization process is occurring. Radial diffusion tends to favor local 90-degree particles. As diffusion occurs, the pitch angle distribution becomes more 90-degree peaked, or transitions from one type of distribution to another, for example butterfly to flattop. We show examples of the diffusion of PADs at higher L-shells, consistent with radial diffusion, and examples inconsistent with radial diffusion at lower L-shells and near the plasmapause.

Gannon, J.; Li, X.; Heyndericks, D.

2005-12-01

256

Production of Gluconic Acid by Some Local Fungi  

PubMed Central

Forty-one fungal species belonging to 15 fungal genera isolated from Egyptian soil and sugar cane waste samples were tested for their capacity of producing acidity and gluconic acid. For the tests, the fungi were grown on glucose substrate and culture filtrates were examined using paper chromatography analysis. Most of the tested fungi have a relative wide potentiality for total acid production in their filtrates. Nearly 51% of them showed their ability of producing gluconic acid. Aspergillus niger was distinguishable from other species by its capacity to produce substantial amounts of gluconic acid when it was cultivated on a selective medium. The optimized cultural conditions for gluconic acid yields were using submerged culture at 30? at initial pH 6.0 for 7 days of incubation. Among the various concentrations of substrate used, glucose (14%, w/v) was found to be the most suitable carbon source for maximal gluconic acid during fermentation. Maximum values of fungal biomass (10.02 g/l) and gluconic acid (58.46 g/l) were obtained when the fungus was grown with 1% peptone as sole nitrogen source. Influence of the concentration of some inorganic salts as well as the rate of aeration on the gluconic acid and biomass production is also described.

Shindia, A. A.; El-Esawy, A. E.; Sheriff, Y. M. M. M.

2006-01-01

257

Incentives for Combined Production of Heat and Power in Some Countries.  

National Technical Information Service (NTIS)

This study examines the incentives for cogeneration (combined production of heat and power) in some countries. The most thorough study was made in USA where cogeneration at industrial facilities is provided with considerable tax credits. Moreover, in USA ...

J. Pellikka J. Koskiniemi

1986-01-01

258

Energy Production from Waste Heat by Means of Elastomers or Memory Metals.  

National Technical Information Service (NTIS)

Results are given of an examination of the possibility of energy production from waste heat with memory metals or elastomers. A primary concern has been to present a general description of the thermodynamic limitations on extracting the energy content of ...

L. Ljung

1982-01-01

259

The collapse of the local, Spitzer-Haerm formulation and a global-local generalization for heat flow in an inhomogeneous, fully ionized plasma  

NASA Technical Reports Server (NTRS)

The breakdown of the classical (CBES) field aligned transport relations for electrons in an inhomogeneous, fully ionized plasma as a mathematical issue of radius of convergence is addressed, the finite Knudsen number conditions when CBES results are accurate is presented and a global-local (GL) way to describe the results of Coulomb physics moderated conduction that is more nearly appropriate for astrophysical plasmas are defined. This paper shows the relationship to and points of departure of the present work from the CBES approach. The CBES heat law in current use is shown to be an especially restrictive special case of the new, more general GL result. A preliminary evaluation of the dimensionless heat function, using analytic formulas, shows that the dimensionless heat function profiles versus density of the type necessary for a conduction supported high speed solar wind appear possible.

Scudder, J. D.; Olbert, S.

1983-01-01

260

Production and Utilization of Biogas and Compost Heat.  

National Technical Information Service (NTIS)

The report deals with a plant for biogas production from manure in Rogaland (Norway). The production capacity will be about 0.6 to 1.0 m sup 3 of biogas per m sup 3 of reactor volume and day. The environmental effects have been analysed, and process param...

O. Tjernshaugen J. F. Hanssen

1984-01-01

261

Truly meshless localized type techniques for the steady-state heat conduction problems for isotropic and functionally graded materials  

Microsoft Academic Search

A numerical solution of steady-state heat conduction problems is obtained using the strong form meshless point collocation (MPC) method. The approximation of the field variables is performed using the Moving Least Squares (MLS) and the local form of the multiquadrics Radial Basis Functions (LRBF). The accuracy and the efficiency of the MPC schemes (with MLS and LRBF approximations) are investigated

E. D. Skouras; G. C. Bourantas; V. C. Loukopoulos; G. C. Nikiforidis

2011-01-01

262

Convective heat transfer coefficient model for spherical products subject to hydrocooling  

SciTech Connect

An analytical model was developed to determine the convective heat transfer coefficients of spherical products being cooled in any medium. In order to verify the present model, the experimental center temperature measurements of the individual spherical products (i.e., plums, peaches, tomatoes, pears) were determined in batches containing 5 and 20 kg of product. It was found that the convective heat transfer coefficient of an individual product varied with the batch weight. This study shows that the present model is a simple and effective tool to determine such coefficients and could be a benefit to the refrigeration industry.

Dincer, I. [TUBITAK-Marmara Research Center, Gebze (Turkey)

1996-09-01

263

Nucleolar Localization of RNA Binding Proteins Induced by Actinomycin D and Heat Shock in Trypanosoma cruzi  

PubMed Central

In this work we show that under Actinomycin D (ActD) treatment, several RNA Binding Proteins (RBPs) involved in mRNA metabolism are relocalized into the nucleolus in Trypanosoma cruzi as a specific stress response. ATP depletion as well as kinase inhibition markedly reduced the nucleolar localization response, suggesting that an energy-dependent transport modulated by the phosphorylation status of the parasite might be required. Deletion analyses in one of such proteins, TcSR62, showed that a domain bearing basic amino acids located in the COOH terminal region was sufficient to promote its nucleolar relocalization. Interestingly, we showed that in addition to RBPs, poly(A)+ RNA is also accumulated into the nucleolus in response to ActD treatment. Finally, we found out that nucleolar relocalization of RBPs is also triggered by severe heat shock in a reversible way. Together, these results suggest that the nucleolus of an early divergent eukaryote is either able to sequester key factors related to mRNA metabolism in response to transcriptional stress or behaves as a RBP processing center, arguing in favour to the hypothesis that the non-traditional features of the nucleolus could be acquired early during evolution.

Nazer, Ezequiel; Verdun, Ramiro E.; Sanchez, Daniel O.

2011-01-01

264

A (S)TEM Gas Cell Holder with Localized Laser Heating for In Situ Experiments  

SciTech Connect

The advent of aberration correction for transmission electron microscopy has transformed atomic resolution imaging into a nearly routine technique for structural analysis. Now an emerging frontier in electron microscopy is the development of in situ capabilities to observe reactions at atomic resolution in real time and within realistic environments. Here we present a new in situ gas cell holder that is designed for compatibility with a wide variety of sample type (i.e., dimpled 3-mm discs, standard mesh grids, various types of focused ion beam lamellae attached to half grids). Its capabilities include localized heating and precise control of the gas pressure and composition while simultaneously allowing atomic resolution imaging at ambient pressure. The results show that 0.25-nm lattice fringes are directly visible for nanoparticles imaged at ambient pressure with gas path lengths up to 20 ?m. Additionally, we quantitatively demonstrate that while the attainable contrast and resolution decrease with increasing pressure and gas path length, resolutions better than 0.2 nm should be accessible at ambient pressure with gas path lengths less than the 15 ?m utilized for these experiments.

Mehraeen, S.; McKeown, J.; Deshmukh, Pushkarraj V.; Evans, James E.; Abellan Baeza, Patricia; Xu, Pinghong; Reed, Bryan W.; Taheri, Mitra L.; Fischione, Paul E.; Browning, Nigel D.

2013-04-01

265

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

NASA Astrophysics Data System (ADS)

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.

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

2012-02-01

266

Controlled Cavitation for Scale-Free Heating, Gum Hydration and Emulsification in Food and Consumer Products  

Microsoft Academic Search

\\u000a Cavitation is defined as the sudden formation and collapse of bubbles in liquid by means of a mechanical force. As bubbles\\u000a rapidly form and collapse, pressurized shock waves, localized heating events and tremendous shearing forces occur. As microscopic\\u000a cavitation bubbles are produced and collapse, shockwaves are given off into the liquid, which can result in heating and\\/or\\u000a mixing, similar to

Douglas G. Mancosky; Paul Milly

2011-01-01

267

Identification of potential local isolated for biosurfactant production  

NASA Astrophysics Data System (ADS)

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.

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

2013-11-01

268

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

SciTech Connect

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.

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

2000-04-04

269

Local heat transfer in rotating smooth and ribbed two-pass square channels with three channel orientations  

SciTech Connect

This paper presents experimental heat transfer results in a two-pass square channel with smooth and ribbed surfaces. The ribs are placed in a staggered half-V fashion with the rotation orthogonal to the channel axis. The channel orientation varies with respect to the rotation plane. A change in the channel orientation about the rotating frame causes a change in the secondary flow structure and associated flow and turbulence distribution. Consequently, the heat transfer coefficient from the individual surfaces of the two-pass square channel changes. The effects of rotation number on local Nusselt number ratio distributions are presented. Heat transfer coefficients with ribbed surfaces show different characteristics in rotation number dependency from those with smooth surfaces. Results show that staggered half-V ribs mostly have higher heat transfer coefficients than those with 90 and 60 deg continuous ribs. 16 refs., 10 figs.

Dutta, S. [Univ. of South Carolina, Columbia, SC (United States); Han, J.C. [Texas A& M Univ., College Station, TX (United States)

1996-08-01

270

Non-local-thermodynamical-equilibrium effects in the x-ray emission of radiatively heated materials of different atomic numbers.  

PubMed

X-ray self-emission of radiatively heated materials with different values of Z has been investigated. Thin foils were uniformly heated by a 120-eV Hohlraum radiation of 400-ps duration in order to study the self-emission of a homogeneous, optically thin material. The x-ray emission spectra were followed for more than 2 ns. The spectrally integrated emission shows not only a strong Z dependence, but different temporal behaviors for different values of Z. The lower is the value of Z of the x-ray heated matter, the longer is the duration of self-emission. Theoretical comparison with a hydrocode and FLY post-processing shows a non-local-thermal equilibrium behavior caused by direct photoionization due to the thermal pumping radiation, which has a higher brightness temperature than the matter temperature of the heated material. PMID:11461413

Földes, I B; Eidmann, K; Veres, G; Bakos, J S; Witte, K

2001-07-01

271

Effects of local lexical competition and regional dialect on vowel production.  

PubMed

Global measures of lexical competition, such as lexical neighborhood density, assume that all phonological contrasts contribute equally to competition. However, effects of local phonetic similarity have also been observed in speech production processes, suggesting that some contrasts may lead to greater competition than others. In the current study, the effect of local lexical competition on vowel production was examined across two dialects of American English that differ in the phonetic similarity of the low-front and low-back vowel pairs. Results revealed a significant interaction between regional dialect and local lexical competition on the acoustic distance within each vowel pair. Local lexical contrast led to greater acoustic distance between vowels, as expected, but this effect was significantly enhanced for acoustically similar dialect-specific variants. These results were independent of global neighborhood density, suggesting that local lexical competition may contribute to the realization of sociolinguistic variation and phonological change. PMID:24993188

Clopper, Cynthia G; Tamati, Terrin N

2014-07-01

272

The representation of the Chinese product crisis in national and local newspapers in the United States  

Microsoft Academic Search

This paper examines how national and local newspapers in the United States frame Chinese product recalls in 2007. First, it reviews literature on international communication and framing. Second, it content analyzes the presentations of the Chinese product recalls in two leading national newspapers, including the New York Times and the USA today, and six major newspapers from five Southern states,

Hongmei Li; Lu Tang

2009-01-01

273

A Productivity Measurement System for State and Local Government Purchasing and Materials Management Services, Executive Summary.  

National Technical Information Service (NTIS)

This research provides local governments with valid approaches and procedures for measuring the productivity of the Purchasing and Materials Management (P&MM) function. The authors attempt to identify the state-of-the-art of P&MM productivity measurements...

1978-01-01

274

A Calorimeter for Rapid Determination of Heat Loss and Heat Production in Laboratory Animals  

Microsoft Academic Search

A rapid calorimeter of the gradient type, suitable for laboratory animals, has been built and tested. A thin gradient layer (0.015-inch woven glass tape) of relatively high thermal conductivity is used to line the walls of the calorimeter. The heat flow rate across the gradient layer is measured by means of 2152 copper-constantan thermal junctions wired in series. With an

Richard W. Lawton; Lawrence R. Prouty; James D. Hardy

1954-01-01

275

Heat Inactivation of Milk Phosphatase in Dairy Products  

Microsoft Academic Search

A description of the phosphatase test and the modifications that make it ap- plicable to various dairy products to determine the adequacy of pasteurization was loublished in 1947 (12). In a later publication (13), it was pointed out that negative results with the phosphatase test indicate that the pathogenic organisms that may have been present were destroyed. With a phosphatase

George P. Sanders; Oscar S. Sager

1948-01-01

276

Heat Production During Countermeasure Exercises Planned for the International Space Station  

NASA Technical Reports Server (NTRS)

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.

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

2004-01-01

277

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

NASA Astrophysics Data System (ADS)

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 1 MHz, 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.

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

2012-11-01

278

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

PubMed

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 1 MHz, 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

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

2012-11-21

279

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

NASA Technical Reports Server (NTRS)

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.

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

1956-01-01

280

Effect of radio frequency (RF) heating on the texture, colour and sensory properties of a comminuted pork meat product  

Microsoft Academic Search

Radio frequency (RF) cooking is a form of dielectric heating in which products are heated by subjecting them to an alternating electromagnetic field between two parallel electrodes. Although similar in some respects to Microwave heating, RF has been proposed to be more suitable for industrial heating of meats because of the greater penetration depths possible with this technology. In this

Nigel P. Brunton; James G. Lyng; Wenqu Li; Denis A. Cronin; Desmond Morgan; Brian McKenna

2005-01-01

281

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

NASA Astrophysics Data System (ADS)

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.

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

2011-10-01

282

Local convection heat transfer coefficient measurement in a wavy channel with flow disturbers  

Microsoft Academic Search

The need for high performance heat exchangers has led to the development of many types of surfaces that enhance the rate of heat transfer. The simplest and most common surface configuration for a two-fluid compact heat exchanger is the plate-fin arrangement. Examples of types of plate-fin surfaces are: plain, louvered, strip, pin, perforated and wavy. Wavy-fin surfaces are high performance

Said Dini; Richard R. Veronesi; Robert K. Huff

2002-01-01

283

Cerebral Metabolism during Cord Occlusion and Hypoxia in the Fetal Sheep: A Novel Method of Continuous Measurement Based on Heat Production  

PubMed Central

This study was undertaken to validate a new method of measuring cerebral metabolic rate in the fetal sheep based on heat production in a local region of the brain. Heat production was compared to oxygen use in 20 near-term fetuses during basal conditions, moderate hypoxia and cord occlusion. Thermocouples were placed to measure core and brain temperature and a composite probe placed in the parietal cortex to measure changes in cortical blood flow (CBF) using laser Doppler flowmetry and tissue PO2 using fluorescent decay. Catheters were inserted in a brachiocephalic artery and sagittal sinus for blood sampling. With moderate hypoxia, induced by administering 10?12 % oxygen to the ewes, fetal arterial PO2 declined from 23 ± 1 to 11 ± 1 Torr and brain tissue PO2 fell from 7.6± 0.7 to a nadir of 0.8 ± 0.4 Torr, while CBF increased to 139 ± 5 % of baseline. Cortical heat production, calculated as the product of CBF, the temperature gain from artery to brain tissue, and the specific heat of blood, decreased by 45 ± 11 % in parallel to similar declines in oxygen uptake. With severe asphyxia induced by complete cord occlusion for 10 min, fetal arterial PO2 declined from 23 ± 1 to 9 ± 2 Torr and brain tissue PO2 fell from 7.0 ± 0.7 to essentially 0 Torr while CBF decreased 40 ± 5 %. Cortical heat production decreased by 78 ± 6 % while oxygen use declined by 90 ± 3 %. Glucose uptake increased significantly relative to oxygen use and lactate concentration increased in sagittal sinus blood. We conclude that local measurements of heat production in the brain provide a useful index of overall metabolic rate, closely reflecting oxygen use in moderate hypoxia and indicating a significant contribution from anaerobic metabolism during severe asphyxia.

Hunter, Christian J; Blood, Arlin B; Power, Gordon G

2003-01-01

284

Production and localization of beta-fructosidase in asynchronous and synchronous chemostat cultures of yeasts.  

PubMed

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

Rouwenhorst, R J; van der Baan, A A; Scheffers, W A; Van Dijken, J P

1991-02-01

285

Effect of a rotor wake on the local heat transfer on the forward half of a circular cylinder  

NASA Technical Reports Server (NTRS)

Turbine rotor-stator wake dynamics was simulated by a spoked wheel rotating in annular flow, generating rotor wakes. Spanwise averaged circumferentially local heat transfer in the circular cylindrical leading edge region of a turbine airfoil was obtained. Reynolds numbers ranged from 35,000 to 175,000. Strouhal numbers ranged from 0.63 to 2.50. Wakes were generated by 2 sets of circular cylindrical bars, 1.59 and 3.18 mm in diameter. The rotor could be rotated either clockwise or counterclockwise. Grid turbulence was introduced upstream yielding freestream turbulence of 1.0 to 2.5% at the stator. Data represented an extensive body of local heat transfer coefficients, which can be used to model the leading edge region of a turbine airfoil. In the presence of rotor wakes, an asymmetry from the leeward to windward side was noted. Windward side levels were 30 to 40% higher than the corresponding leeward side.

Morehouse, K. A.; Simoneu, R. J.

1986-01-01

286

Design of a Compact Ceramic High Temperature Heat Exchanger and Chemical Decomposer for Hydrogen Production  

Microsoft Academic Search

This article describes a compact silicon carbide ceramic, high-temperature heat exchanger for hydrogen production in the sulfur iodine thermo-chemical cycle; and in particular, to be used as the sulfuric acid decomposer. In this cycle, hot helium from a nuclear reactor is used to heat the SI (sulfuric acid) feed components (H2O, H2SO4, SO3) to obtain appropriate conditions for the SI

VALERY PONYAVIN; YITUNG CHEN; TAHA MOHAMED; MOHAMED TRABIA; ANTHONY E. HECHANOVA; MERRILL WILSON

2012-01-01

287

Design of a Compact Ceramic High-Temperature Heat Exchanger and Chemical Decomposer for Hydrogen Production  

Microsoft Academic Search

This article describes a compact silicon carbide ceramic, high-temperature heat exchanger for hydrogen production in the sulfur iodine thermochemical cycle, and in particular, to be used as the sulfuric acid decomposer. In this cycle, hot helium from a nuclear reactor is used to heat the SI (sulfuric acid) feed components (H2O, H2SO4, SO3) to obtain appropriate conditions for the SI

Valery Ponyavin; Yitung Chen; Taha Mohamed; Mohamed Trabia; Anthony E. Hechanova; Merrill Wilson

2012-01-01

288

Lymphatic absorption of nonvolatile oxidation products of heated oils in the rat  

Microsoft Academic Search

The lymphatic absorption of nonvolatile oxidation products (NVOP) formed during heating of fats was studied. Heated colza\\u000a or soybean oils or synthetic triglycerides containing a definite aromatic or alicyclic fatty acid were fed to thoracic duct-cannulated\\u000a rats. Tritium-labeled triolein was added to each dietary fat, as an internal standard, in order to calculate the percentage\\u000a of lymphatic absorption of the

N. Combe; M. J. Constantin; B. Entressangles

1981-01-01

289

Experimental Production of Heat-Island Map with Satellite and Airborne Thermal Infrared Data  

Microsoft Academic Search

The purpose of this study is experimental production of heat-island map with satellite and airborne thermal infrared data. In Japan, at almost of all cities, including not only major cities (i.e. Tokyo, Osaka, population is over one million) but also provincial cities (i.e. Sendai, Nagano, Kofu and so on, population is 100 thousands to 500 thousands), there are heat island

Naoki Takagi; Akira Hoyano; Akinobu Murakami; Tsuneo Matsunaga

2008-01-01

290

Simulated heat flux and sea ice production at coastal polynyas in the southwestern Weddell Sea  

NASA Astrophysics Data System (ADS)

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.

Haid, V.; Timmermann, R.

2013-05-01

291

Locally indistinguishable subspaces spanned by three-qubit unextendible product bases  

SciTech Connect

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.

Duan Runyao; Ying Mingsheng [Centre for Quantum Computation and Intelligent Systems (QCIS), Faculty of Engineering and Information Technology, University of Technology, Sydney, New South Wales 2007 (Australia); State Key Laboratory of Intelligent Technology and Systems, Tsinghua National Laboratory for Information Science and Technology, Department of Computer Science and Technology, Tsinghua University, Beijing 100084 (China); Xin Yu [Computer Science and Artificial Intelligence Laboratory, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Department of Physics, Tsinghua University, Beijing 100084 (China)

2010-03-15

292

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

SciTech Connect

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.

McCabe, D.E.

1999-09-01

293

Influence of local heating on current-optical output power characteristics in Ga1 - xAlxAs lasers  

Microsoft Academic Search

Available optical output powers from the Ga1?xAlxAs lasers are limited by the catastrophic optical damage or output power saturation due to local heating on the facet. Especially, the saturation of current-optical output power characteristically occurs during the operations at relatively low output power. This report describes the degradation process in an active region for lasers with the striped window as

Satoru Todoroki

1986-01-01

294

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

SciTech Connect

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.

Karamavruc, A.I.; Clark, N.N. [West Virginia Univ., Morgantown, WV (United States). Dept. of Mechanical and Aerospace Engineering

1996-09-01

295

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

NASA Technical Reports Server (NTRS)

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.

Liebert, Curt H.; Ehlers, Robert C.

1961-01-01

296

Paeaestoenormien vaikutus saehkoen- ja laemmoentuotannon kapasiteetin kaeyttoeikaeaen. (Power and heat production capacity retirement depending on environmental regulations).  

National Technical Information Service (NTIS)

The report studies the retirement of the power and heat production capacity which was in operation at the beginning of 1991. The plant by plant evaluation included industrial process power, district heating power and conventional condensation power, corre...

S. Helynen A. Asikainen H. Maskuniitty

1992-01-01

297

Materials experience and selection for nuclear materials production reactor heat exchangers  

SciTech Connect

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).

Marra, J.E.; Louthan, M.R. Jr.

1990-01-01

298

Localized dryout: An approach for managing the thermal hydrologi-cal effects of decay heat at Yucca Mountain  

SciTech Connect

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.

Buscheck, T. A.; Nitao, J.J.; Ramspott, L.D.

1995-11-01

299

Analysis of Competitiveness and Support Instruments for Heat and Electricity Production from Wood Biomass in Latvia  

NASA Astrophysics Data System (ADS)

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.

Klavs, G.; Kudrenickis, I.; Kundzina, A.

2012-01-01

300

The Effects of Cesarean Section Anesthesia on Heat Loss and Heat Production in the Newborn Rabbit  

PubMed Central

The newborn of some smaller animals rely upon heat produced by nonshivering thermogenesis in the brown fat to prevent a fall in body temperature after birth. Because of their pharmacological properties, some drugs may affect nonshivering thermogenesis. Therefore, in this study, the ability of newborn rabbits delivered under Innovar-Vet, ketamine hydrochloride, methoxyflurane and epidural anesthesia to maintain the rectal, subcutaneous interscapular and lumbar temperature was investigated at an ambient temperature of 35°C or 22°C and the results compared with control newborns delivered without anesthesia. When the newborns were exposed to 35°C, the anesthetics studied had no effect on the ability of the newborn to maintain the rectal temperature and the subcutaneous temperature over the interscapular fat pad was similar to the lumbar subcutaneous temperature thereby indicating that nonshivering thermogenesis was not activated. However, at an ambient temperature of 22°C Innovar-Vet or methoxyflurane reduced the temperature difference between interscapular and lumbar temperatures to 1.6°C compared to 2.5°C in controls and the difference between core temperature and ambient temperature to 3.5°C greater compared to 7.5°C in controls. Ketamine hydrochloride or lidocaine hydrochloride plus meperidine has less effect because these compounds lack adrenergic blocking properties. These data suggest that newborns delivered under anesthetics or tranquillizers that have adrenergic blocking properties require a warm (35°C) environment to prevent a fall in core temperature.

Harris, W.H.; Yamashiro, S.; Stopps, T.P.

1983-01-01

301

Heat treatment of retinal pigment epithelium induces production of elastic lamina components and antiangiogenic activity  

PubMed Central

Age-related macular degeneration (AMD) is the leading cause of blindness in the Western world. In advanced AMD, new vessels from choriocapillaris (CC) invade through the Bruch's membrane (BrM) into the retina, forming choroidal neovascularization (CNV). BrM, an elastic lamina that is located between the retinal pigment epithelium (RPE) and CC, is thought to act as a physical and functional barrier against CNV. The BrM of patients with early AMD are characterized by decreased levels of antiangiogenic factors, including endostatin, thrombospondin-1 (TSP-1), and pigment epithelium-derived factor (PEDF), as well as by degeneration of the elastic layer. Motivated by a previous report that heat increases elastin expression in human skin, we examined the effect of heat on human ARPE-19 cell production of BrM components. Heat treatment stimulated the production of BrM components, including TSP-1, PEDF, and tropoelastin in vitro and increased the antiangiogenic activity of RPE measured in a mouse corneal pocket assay. The effect of heat on experimental CNV was investigated by pretreating the retina with heat via infrared diode laser prior to the induction of CNV. Heat treatment blocked the development of experimental CNV in vivo. These findings suggest that heat treatment may restore BrM integrity and barrier function against new vessel growth.—Sekiyama, E., Saint-Geniez, M., Yoneda, K., Hisatomi, T., Nakao, S., Walshe, T. E., Maruyama, K., Hafezi-Moghadam, A., Miller, J. W., Kinoshita, S., D'Amore, P. A. Heat treatment of retinal pigment epithelium induces production of elastic lamina components and anti-angiogenic activity.

Sekiyama, Eiichi; Saint-Geniez, Magali; Yoneda, Kazuhito; Hisatomi, Toshio; Nakao, Shintaro; Walshe, Tony E.; Maruyama, Kazuichi; Hafezi-Moghadam, Ali; Miller, Joan W.; Kinoshita, Shigeru; D'Amore, Patricia A.

2012-01-01

302

Localization of the mei-1 gene product of Caenorhaditis elegans, a meiotic-specific spindle component  

Microsoft Academic Search

Genetic evidence suggests that the product of the mei-1 gene of Caenorhabditis elegans is specifically required for meiosis in the female germ- line. Loss-of-function mei4 mutations block meiotic spindle formation while a gain-of-function allele in- stead results in spindle defects during the early mitotic cleavages. In this report, we use immunocytochemistry to examine the localization of the mei-1 product in

Shawna Clark-Maguire; Paul E. Mains

1994-01-01

303

Experimental investigation of local heat transfer in the packing with triangular channels  

NASA Astrophysics Data System (ADS)

Results of experimental studies on temperature distribution over the surface of a complex-shape heat exchanger like “Frenkel packing” are presented. Measurements were carried out with the airflow between two corrugated sheets with triangular crimps directed at 90° relative to each other. Microthermocouples glued on the outer surface of the heater were used for measurements. The effect of contact points, Reynolds number, and gap between corrugated sheets on temperature distribution over the heat exchanger surface is analysed under the turbulent mode of airflow. The main attention is paid to temperature distribution over the heating surface in an elementary cell. According to measurements performed, there is insignificant effect of contact points and gap on the type of temperature distribution over the perimeter of heated cell.

Perepelitsa, B. V.

2006-12-01

304

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

National Technical Information Service (NTIS)

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 adv...

R. D. Boyd

1996-01-01

305

A simplified method for thermal analysis of a cowl leading edge subject to intense local shock-wave-interference heating  

NASA Technical Reports Server (NTRS)

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.

Mcgowan, David M.; Camarda, Charles J.; Scotti, Stephen J.

1992-01-01

306

Carbon dioxide local heat transfer coefficients during flow boiling in a horizontal circular smooth tube  

Microsoft Academic Search

Carbon dioxide is gaining renewed interest as an environmentally safe refrigerant. In order to improve the energy efficiency of R744 systems, an accurate knowledge of heat transfer coefficients is fundamental.In this paper experimental heat transfer coefficients during flow boiling of R744 in a smooth, horizontal, circular, 6.00mm inner diameter tube are presented. We obtained 217 experimental points in 18 operating

R. Mastrullo; A. W. Mauro; A. Rosato; G. P. Vanoli

2009-01-01

307

The production of activated carbon using the equipment of thermal power plants and heating plants  

NASA Astrophysics Data System (ADS)

The production technology of activated carbon using the conventional equipment of the thermal power stations and boiler houses is proposed. The obtained product is directed into the systems of chemical water preparation and water drain of enterprises. The production cycle is invariable when producing the activated carbon by the proposed technology. The fuel consumption and heat losses are considerably reduced when implementing this technology compared with the known analogs of the carbon sorbent. The production efficiency increases if small dust particles are preliminary separated and coal is activated in narrow ranges of fraction sizes.

Osintsev, K. V.; Osintsev, V. V.; Dzhundubaev, A. K.; Kim, S. P.; Al'musin, G. T.; Akbaev, T. A.; Bogatkin, V. I.

2013-08-01

308

Mixed convection in a horizontal porous duct with a sudden expansion and local heating from below  

SciTech Connect

Results are reported for an experimental and numerical study of forced and mixed convective heat transfer in a liquid-saturated horizontal porous duct. The cross section of the duct has a sudden expansion with a heated region on the lower surface downstream and adjacent to the expansion. Within the framework of Darcy`s formulation, the calculated and measured Nusselt numbers for 0.1 < Pe < 100 and 50 < Ra < 500 are in excellent agreement. Further, the calculated Nusselt numbers are very close to those for the bottom-heated flat duct. This finding has important implications for convective heat and mass transfer in geophysical systems and porous matrix heat exchangers. The calculations were also carried out for glass bead-packed beds saturated with water using non-Darcy`s formula. The streamlines in the forced convection indicate that, even with non-Darcy effects included, recirculation is not observed downstream of an expansion and the heat transfer rate is decreased but only marginally.

Yokoyama, Y.; Mahajan, R.L. [Univ. of Colorado, Boulder, CO (United States). Dept. of Mechanical Engineering; Kulacki, F.A. [Univ. of Minnesota, Minneapolis, MN (United States). Dept. of Mechanical Engineering

1999-08-01

309

Temperature-humidity indices as indicators of milk production losses due to heat stress.  

PubMed

Meteorological data (1993 to 2004) from 2 public weather stations in Phoenix, Arizona, and Athens, Georgia, were analyzed with test day milk yield data from herds near weather stations to identify the most appropriate temperature-humidity index (THI) to measure losses in milk production due to heat stress in the semiarid climate of Arizona and the humid climate of Georgia. Seven THI with different weightings of dry bulb temperature and humidity were compared. Test-day data were analyzed using 2 models to determine threshold of heat stress and rate of decline of milk production associated with a specific THI. Differences in thresholds of heat stress were found among indices and between regions. Indices with higher weights on humidity were best in the humid climate, whereas indices with larger weights on temperature were the best indicators of heat stress in the semiarid climate. Humidity was the limiting factor of heat stress in humid climates, whereas dry bulb temperature was the limiting factor of heat stress in dry climates. PMID:17369235

Bohmanova, J; Misztal, I; Cole, J B

2007-04-01

310

Covariance of time-ordered products implies local commutativity of fields  

SciTech Connect

We formulate Lorentz covariance of a quantum field theory in terms of covariance of time-ordered products (or other Green's functions). This formulation of Lorentz covariance implies spacelike local commutativity or anticommutativity of fields, sometimes called microscopic causality or microcausality. With this formulation microcausality does not have to be taken as a separate assumption.

Greenberg, O.W. [Center for Theoretical Physics, Department of Physics, University of Maryland, College Park, Maryland 20742-4111 (United States)

2006-04-15

311

Departure from corotation of the IO plasma torus: local plasma production  

Microsoft Academic Search

The departure of the Jovian magnetosphere from rigid corotation is adequately explained by outward plasma transport at distances L> or approx. =10. The departure of 5% observed in the Io plamsa torus, however, is too large to be accounted for simply by plasma transport. We propose local plasma production to be the main factor determining the corotation lag in the

D. H. Jr. Pontius; T. W. Hill

1982-01-01

312

Cleaner production in SMEs through a partnership with (local) authorities: successes from the Netherlands  

Microsoft Academic Search

The contribution of small and medium-sized enterprises (SMEs) to total industrial production and their dominance in some sectors indicate that their contribution to total industrial environmental impact is considerable. This paper therefore focuses on pollution prevention by SMEs and on the ways in which local authorities can become a strategic partner in this process. The paper consists of a theoretical

Marieke Gombault; Stephan Versteege

1999-01-01

313

Field nano-localization of gas bubble production from water electrolysis  

NASA Astrophysics Data System (ADS)

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.

Hammadi, Z.; Morin, R.; Olives, J.

2013-11-01

314

Deletion of muscle GRP94 impairs both muscle and body growth by inhibiting local IGF production  

PubMed Central

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.

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

315

Complex patterns of local adaptation in heat tolerance in Drosophila simulans from eastern Australia.  

PubMed

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

van Heerwaarden, B; Lee, R F H; Wegener, B; Weeks, A R; Sgró, C M

2012-09-01

316

Microcalorimetric measurements of heat production in brown adipocytes from control and cafeteria-fed rats.  

PubMed

The effects of the sequential addition of glucose, noradrenaline, propranolol and oleic acid on the rates of O2 consumption and heat production by isolated interscapular brown adipocytes from control and cafeteria-fed rats were compared. Although the chemical agents produced very similar changes in oxidative metabolism, the actual rates of O2 uptake and heat output in adipocytes from the cafeteria-fed rats, when expressed per g dry wt. of cells, were approx. 65% less than those obtained with cells from the control rats. However, when the same results were expressed per 10(8) multiloccular brown adipocytes, rather than gravimetrically, rates of O2 consumption and heat production were equivalent. Further interpretation of these data is complicated, because the average volume of multiloccular brown adipocytes from cafeteria-fed rats was 2.5 times that for multiloccular cells from control animals. PMID:3741394

Clark, D G; Brinkman, M; Neville, S D

1986-04-15

317

Microcalorimetric measurements of heat production in brown adipocytes from control and cafeteria-fed rats.  

PubMed Central

The effects of the sequential addition of glucose, noradrenaline, propranolol and oleic acid on the rates of O2 consumption and heat production by isolated interscapular brown adipocytes from control and cafeteria-fed rats were compared. Although the chemical agents produced very similar changes in oxidative metabolism, the actual rates of O2 uptake and heat output in adipocytes from the cafeteria-fed rats, when expressed per g dry wt. of cells, were approx. 65% less than those obtained with cells from the control rats. However, when the same results were expressed per 10(8) multiloccular brown adipocytes, rather than gravimetrically, rates of O2 consumption and heat production were equivalent. Further interpretation of these data is complicated, because the average volume of multiloccular brown adipocytes from cafeteria-fed rats was 2.5 times that for multiloccular cells from control animals.

Clark, D G; Brinkman, M; Neville, S D

1986-01-01

318

Maan laemmittaeminen avomaan puutarhatuotannossa. (Soil heating in connection with outdoor garden production).  

National Technical Information Service (NTIS)

Soil heating using electricity, hot water and air has been studied within Nordic countries as a way to extend the growing season in spring. The methods have not found general acceptance in practical outdoor garden production in Nordic countries, except in...

S. Malkki J. Moilanen

1991-01-01

319

Regulation of Heat Production in the Inflorescences of an Arum Lily by Endogenous Salicylic Acid  

Microsoft Academic Search

We have recently purified calorigen, the natural trigger for heat production in the inflorescences of Sauromatum guttatum Schott (voodoo lily), a thermogenic plant, and identified it as salicylic acid. Since then an analytical assay was developed that allows the quantitation of salicylic acid in plant tissues. This assay was used to demonstrate that on the day preceding the day of

Ilya Raskin; Ivan M. Turner; Wayne R. Melander

1989-01-01

320

Temperature-Humidity Indices as Indicators of Milk Production Losses due to Heat Stress  

Microsoft Academic Search

Meteorological data (1993 to 2004) from 2 public weather stations in Phoenix, Arizona, and Athens, Georgia, were analyzed with test day milk yield data from herds near weather stations to identify the most appropriate temperature-humidity index (THI) to mea- sure losses in milk production due to heat stress in the semiarid climate of Arizona and the humid climate of Georgia.

J. Bohmanova; I. Misztal; J. B. Cole

2007-01-01

321

Feasibility of Continuous Heat Sterilization of Food Products Using Microwave Power.  

National Technical Information Service (NTIS)

A continuous system for the thermal processing of food in plastic pouches has been developed in which over-riding air pressure is used to balance internal pressure and prevent pouch rupture. The pouches are filled with 6-8 ozs of food product, heat sealed...

E. M. Kenyon

1970-01-01

322

Combustion of pyrotechnic mixtures with heat transfer from gaseous reaction products  

Microsoft Academic Search

The existence of a steady combustion wave in the porous reacting mass of a chemical gas generator, with heat transfer to the original substance from the gaseous reaction products, has been confirmed theoretically and by experimental data. In this case, the combustion temperature exceeds the adiabatic combustion temperature. Possible combustion mechanisms are discussed.

A. P. Aldushin; K. I. Zeinenko

1991-01-01

323

Measurement of local strain and heat propagation during high-temperature testing in a split-Hopkinson tension bar system  

NASA Astrophysics Data System (ADS)

Aluminium alloys are commonly used by the industry due to their good mechanical properties and their relatively low density. An accurate prediction of the behaviour of aluminium alloys under a wide range of temperatures and strain rates is important in numerical simulations of forming processes or applications involving adiabatic heating like penetration and crash situations. Several tests are needed at low, medium and high strain rates to study this behaviour. This paper will focus on the high strain rate test rig, which is a split- Hopkinson tension bar system (SHTB), the acquisition system for strain measurements, and a thermal analysis of the bars due to heating of the sample. A new way of doing local measurements with a high-speed camera will be presented. The thermal boundary conditions of the tests have been measured and simulated, and the results indicate that the stress wave propagation in the bars is not significantly affected by a local heating of the part of the bars which is closest to the sample.

Vilamosa, V.; Clausen, A. H.; Hopperstad, O. S.; Børvik, T.; Skjervold, S.

2012-08-01

324

Bioequivalence for locally acting nasal spray and nasal aerosol products: standard development and generic approval.  

PubMed

Demonstrating bioequivalence (BE) for nasal spray/aerosol products for local action has been very challenging because the relationship between the drug in systemic circulation and the drug reaching the nasal site of action has not been well established. Thus, the current BE standard for these drug/device combination products is based on a weight-of-evidence approach, which contains three major elements: equivalent in vitro performance, equivalent systemic exposure, and equivalent local delivery. In addition, formulation sameness and device similarity are evidences to support BE. This paper presents a comprehensive review of the scientific rationale of the current BE standard and their development history for nasal spray/aerosol products, as well as the Food and Drug Administration's review and approval status of generic nasal sprays/aerosols with the application of these BE standard. PMID:23686396

Li, Bing V; Jin, Feiyan; Lee, Sau L; Bai, Tao; Chowdhury, Badrul; Caramenico, Hoainhon T; Conner, Dale P

2013-07-01

325

Influence of pubertal stage on local sweating patterns of girls exercising in the heat.  

PubMed

The influence of puberty on sweating patterns of girls exercising in the heat is not known. Nine- to 17-year-old girls, representing 4 stages of breast development: T1 (n = 21); T2 (n = 22); T3 (n = 25); and T4 (n = 22), cycled for 20 min at 60% in 35 °C. The population density of heat activated sweat glands was higher in T1 vs T3 and T4 and in T2 vs T4. Sweat drop area was lower in T1 vs T3 and in T1 vs T4, T2 vs T4 and T3 vs T4. The proportion of skin covered by sweat was lower in T1 vs T4. Sweating patterns of girls exercising in the heat are influenced by pubertal stage. PMID:23749395

Wilk, Boguslaw; Pender, Nola; Volterman, Kim; Bar-Or, Oded; Timmons, Brian W

2013-05-01

326

Localized products of futile cycle/lrmp promote centrosome-nucleus attachment in the zebrafish zygote  

PubMed Central

SUMMARY Background The centrosome has a well-established role as a microtubule organizer during mitosis and cytokinesis. In addition, it facilitates the union of parental haploid genomes following fertilization by nucleating a microtubule aster along which the female pronucleus migrates towards the male pronucleus. Stable associations between the sperm aster and the pronuclei are essential during this directed movement. Results Our studies reveal that the zebrafish gene futile cycle (fue) is required in the zygote for male pronucleus-centrosome attachment and female pronuclear migration. We show that fue encodes a novel, maternally-provided long form of lymphoid-restricted membrane protein (lrmp), a vertebrate-specific gene of unknown function. Both maternal lrmp mRNA and protein are highly localized in the zygote, in a largely overlapping pattern at nuclear membranes, centrosomes, and spindles. Truncated Lrmp-EGFP fusion proteins identified subcellular targeting signals in the C-terminus of Lrmp, however endogenous mRNA localization is likely important to ensure strict spatial expression of the protein. Localization of both Lrmp protein and lrmp RNA is defective in fue mutant embryos, indicating that correct targeting of lrmp gene products is dependent on Lrmp function. Conclusions Lrmp is a conserved vertebrate gene whose maternally-inherited products are essential for nucleus-centrosome attachment and pronuclear congression during fertilization. Precise subcellular localization of lrmp products also suggests a requirement for strict spatiotemporal regulation of their function in the early embryo.

Lindeman, Robin Emily; Pelegri, Francisco

2012-01-01

327

Heat Storage in Urban Areas: Local-Scale Observations and Evaluation of a Simple Model  

Microsoft Academic Search

The flux density of sensible heat to or from storage in the physical mass of the city is determined for seven cities (Chicago, Illinois; Los Angeles, California; Mexico City, Distrito Federal; Miami, Florida; Sacramento, California; Tucson, Arizona; and Vancouver, British Columbia) in North America across a 308 latitudinal range. These cities have a variety of synoptic-scale climates and surface cover

C. S. B. Grimmond; T. R. Oke

1999-01-01

328

Electrostatic coherent structures generation by local heating in a collisionless plasma  

Microsoft Academic Search

We propose a new mechanism for the generation of electrostatic coherent structures and Langmuir fluctuations in a stratified plasma. The model is base on open boundary 1D Vlasov simulations where heated electrons are injected by applying a temporal continuous periodic modification of the width of the electron distribution function at one boundary of the simulation box. To our knowledge, that

C. Briand; A. Mangeney; F. Califano

2007-01-01

329

Characterization of smallholder pig production system: productive and reproductive performances of local and crossbred pigs in Sikkim Himalayan region.  

PubMed

The present study was conducted to know the smallholder pig production system in tribal areas of Sikkim State, India. Two hundred tribal farmers were selected randomly from the North and East District of the state. Information on socio-economic characteristics of farmers (gender, occupation, educational status, and farming experience), management practices, disease prevalence, and economics in pig production was collected. The study recorded the mean land holding as 1.2 ± 0.8 ha, and the number of pigs per farm was 5.0 ± 0.28. Pigs were mainly kept as a source of income, and 70 % of farmers reared crossbreed pigs. Ninety percent (90 %) of respondents practiced the intensive system of management whereby kitchen wastes along with cooked mixture comprising maize bhusa, mustard oil cake, pseudostem of banana, tuber, stem, and plant leaves were used to feed their animals. About 40.5 % of farmers procured their breeding stock from government farms that had good records and utilized veterinary services like timely vaccination and deworming. The diseases prevalent in the study area were swine fever, diarrhea, helminthoses, sarcoptic mange, pneumonia, etc. The litter sizes at birth (local, 4.3 ± 0.45; crossbreed, 7.2 ± 0.33), at weaning (local, 2.79 ± 0.24; crossbreed, 6.1 ± 0.21), and age at first farrowing (local, 365.39 ± 7.96 days; crossbreed, 337.24 ± 8.79 days) were recorded. Production costs of meat extracted from local and crossbred pigs were 1.08 $/kg and 0.86 $/kg, respectively. PMID:23636408

Nath, B G; Pathak, P K; Ngachan, S V; Tripathi, A K; Mohanty, A K

2013-10-01

330

The impact of local geochemical variability on quantifying hillslope soil production and chemical weathering  

NASA Astrophysics Data System (ADS)

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 2? 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.

Heimsath, Arjun M.; Burke, Benjamin C.

2013-10-01

331

Local heat transfer distribution in a square channel with 90 continuous, 90 saw tooth profiled and 60 broken ribs  

SciTech Connect

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)

Gupta, Abhishek; SriHarsha, V.; Prabhu, S.V.; Vedula, R.P. [Department of Mechanical Engineering, IIT Bombay, Powai, Mumbai 400 076 (India)

2008-02-15

332

Identification of plasma structures with local enhancement in temperature and implication for intermittent heating of the solar wind  

NASA Astrophysics Data System (ADS)

Observationally, the solar wind temperature fluctuations are highly intermittent, especially at small scales. This phenomenon may contain information about solar wind intermittent heating and turbulence intermittent cascading. However, the physical nature of temperature intermittency is not yet clear. To clarify this issue, we identified the plasma structures associated with local temperature enhancements (may be called temperature peaks, TPs) according to their high normalized partial variance of increment (PVI) in temperature, which is the ratio between the local temperature difference for a time lag (24 seconds) and the standard deviation of those temperature differences. The plasma data observed by the WIND spacecraft in high-speed streams are used for this study. It is found that about 70% of the TPs are associated with linear magnetic holes (LMH) and 30% with TD-associated current sheets (TCSs). The TP-associated LMH have characteristic features, such as magnetic-amplitude dip of 30%-80% only in L (MVA) direction, extension of 80-800 proton gyro-radius, temperature anisotropy, and density enhancement in some cases, and plasma-beta peak which may be consistent with the mirror mode instability. However, some additional new features are also found. The cross-helicity (sigma_c) is in some cases high, which is not consistent with predictions for the mirror mode instability, but may indicate a possible relation with Alfven waves. Some cases show dips in total pressure, perhaps indicating non-static convection of the structures. The high percentage of LMHs associated with TPs may suggest that solar wind intermittent heating is mainly due to the processes which create LMH, such as the cyclotron resonance heating, mirror mode instability, or obliquely propagating large-amplitude Alfven waves. Magnetic reconnection in TD-associated current sheets may also contribute considerably to intermittent heating. How turbulence with intermittent cascade can produce such structures, as LMHs and TCSs, will be a topic for future studies.

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

2013-12-01

333

Differences and implications in biogeochemistry from maximizing entropy production locally versus globally  

NASA Astrophysics Data System (ADS)

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.

Vallino, J. J.

2011-01-01

334

Differences and implications in biogeochemistry from maximizing entropy production locally versus globally  

NASA Astrophysics Data System (ADS)

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.

Vallino, J. J.

2011-06-01

335

Periodic structure optimization via local heat pulse-quench cycles employing the GULP code  

NASA Astrophysics Data System (ADS)

We present an optimization algorithm for problems with many continuous degrees of freedom and a huge number of local minima. It is based on the thermal cycling approach, originally developed for combinatorial optimization tasks [1]. The main idea is to cyclically disturb a few randomly chosen degrees of freedom of the current best local minimum and to quench this state by a highly efficient local search code. As the optimization proceeds, the amplitude of the disturbance slowly decreases. This approach is applied to a lattice structure prediction problem. We use the general utility lattice program (GULP) by J.D. Gale and co-workers [2] for local search. As test, the hypothetical periodic Mg10Al4Ge2Si8O36 compound is studied, where both the cell parameters and the atom positions are free to vary. The results demonstrate that the proposed procedure is robust and far more efficient than the previous approaches to this problem by means of multi-start local search, simulated annealing, and evolutionary algorithms in Ref. 3. [4pt] [1] A. M"obius et al., Phys. Rev. Lett. 79 (1997) 4297. [0pt] [2] J.D. Gale and A.L Rohl, Mol. Simul. 29 (2003) 291. [0pt] [3] A.R. Oganov et al., in ``Modern Methods of Crystal Structure Prediction,'' ed. A.R. Organov, (Wiley, 2011), p. 223.

Möbius, Arnulf; Schön, J. Christian

2012-02-01

336

Heat stress impairs the nutritional metabolism and reduces the productivity of egg-laying ducks.  

PubMed

This research was conducted to determine the effect of heat stress on the nutritional metabolism and productivity of egg-laying shelducks. Healthy shelducks (n=120) in the early laying stage (uniform body weights and normal feed intakes) were randomly assigned to two identical climate chambers and exposed to constant high temperature (34°C) or control temperature (23°C) for 28d. The heat-exposed ducks had reduced feed intakes and laying rates (P<0.05), increased frequency of panting and spreading wings and dull featheration; egg weight, eggshell thickness and strength, and Haugh unit also decreased and malondialdehyde (MDA) content of egg yolk increased (P<0.05). Compared with the control ducks, the plasma concentrations of HCO3(-), phosphorus, glucose, thyroxine and activities of glutamic-pyruvic transaminase and glutamic oxaloacetic transaminase were decreased, while there were increased concentrations of corticosterone (P<0.05). The content of MDA and lactate in plasma and liver was greater in heat-exposed than in control ducks, but superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), total antioxidant enzymes (T-AOC) activities and glutathione (GSH) contents were less. The expression of HSP70 gene expression in the liver was increased in heat-stressed ducks. The relative weight of oviduct, number of large ovarian follicles, length of the oviduct all decreased (P<0.05) in heat-treated ducks, as did expression of carbonic anhydrase and calcium binding protein genes in the shell gland as a result of heat stress. In summary, heat stress decreased the productivity of ducks, which related to reduced feed intake, protein synthesis, endocrine dysfunction, less antioxidant capacity, and derangement of calcium and phosphorous balance. PMID:24491646

Ma, Xianyong; Lin, Yingcai; Zhang, Hanxing; Chen, Wei; Wang, Shang; Ruan, Dong; Jiang, Zongyong

2014-03-01

337

Effect of rib angle on local heat/mass transfer distribution in a two-pass rib-roughened channel  

NASA Technical Reports Server (NTRS)

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.

Chandra, P. R.; Han, J. C.; Lau, S. C.

1987-01-01

338

Water flow calorimetry measurements of heat loads for a volume production H/sup -/ source  

SciTech Connect

The design of volume-production H/sup -/ sources requires the knowledge of heat loads on the source components. The arc and filament heater power input to a 20 cm diameter x 23 cm long source can be 50 kW or higher, practically all of which is absorbed in the cooling water. Water flow calorimetry measurements were made to determine the heat loads on the bucket walls, grid no. 1, and magnetic filter rods. The measurements are presented for two different filament locations, for three different values of arc power, and for three values of source gas pressure. 1 ref., 4 figs., 2 tabs.

Purgalis, P.; Ackerman, G.; Kwan, J.; Wells, R.P.

1987-10-01

339

Heat of Combustion of the Product Formed by the Reaction of Acetylene, Ethylene, and Diborane  

NASA Technical Reports Server (NTRS)

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.

Tannenbaum, Stanley

1957-01-01

340

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

SciTech Connect

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.

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

2011-02-01

341

Composite heat-insulating material and process for the production thereof  

SciTech Connect

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.

Yazaki, T.; Hattori, K.; Hattori, S.; Hayama, K.; Itoh, I.

1985-02-19

342

A local heat transfer analysis of lava cooling in the atmosphere: application to thermal diffusion-dominated lava flows  

NASA Astrophysics Data System (ADS)

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.

Neri, Augusto

1998-05-01

343

Heat-resistance of Hamigera avellanea and Thermoascus crustaceus isolated from pasteurized acid products.  

PubMed

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

Scaramuzza, Nicoletta; Berni, Elettra

2014-01-01

344

Heat Transfer Applications of Meshless Local Petrov-Galerkin (MLPG) Method during Plasma Spray  

Microsoft Academic Search

In this work, a compact computational formulation is established based on the truly meshless method MLPG, and is firstly used\\u000a to solve steady and transient heat conductions of the plasma spray. The unknown function of temperature distribution is approximated\\u000a by moving least square approximation functions. These approximants are constructed by using a weight function, a polynomial\\u000a basis and a set

S. C. Wu; H. O. Zhang; G. L. Wang; W. S. Xia

345

On-line corrosion monitoring in geothermal district heating systems. II. Localized corrosion  

Microsoft Academic Search

Corrosion monitoring in district heating systems has traditionally been performed by using off-line methods, such as weight loss. The disadvantage is that the method is very slow, especially in low-corrosive environments, and that it only provides information about the past corrosion (accumulated over period of time). The purpose of the work is to test on-line monitoring methods in geothermal hot

S. Richter; R. I. Thorarinsdottir; F. Jonsdottir

2007-01-01

346

Influence of bubble column diameter on local heat transfer and related hydrodynamics  

Microsoft Academic Search

Heat transfer coefficients measured in a 0.15m ID bubble column are compared with similar studies in larger diameter columns to identify influence of column diameter. Gas phase used is oil free compressed air and its flow rate is varied from 0.03 to 0.35m\\/s. Tap water is the liquid phase and the solid particles used are 49?m glass beads and their

A. K. Jhawar; A. Prakash

2011-01-01

347

Energy confinement and MHD activity in shaped TCV plasmas with localized electron cyclotron heating  

Microsoft Academic Search

Confinement in TCV electron cyclotron heated discharges was studied as a function of plasma shape, i.e. as a function of elongation, 1.1 < kappa< 2.15, and triangularity, -0.65 <= delta <= 0.55. The electron energy confinement time was found to increase with elongation, owing in part to the increase of plasma current with elongation. The beneficial effect of negative triangularities

A. Pochelon; T. P. Goodman; M. Henderson; C. Angioni; R. Behn; S. Coda; F. Hofmann; J.-P. Hogge; N. Kirneva; A. A. Martynov; J.-M. Moret; Z. A. Pietrzyk; F. Porcelli; H. Reimerdes; J. Rommers; E. Rossi; O. Sauter; M. Q. Tran; H. Weisen; S. Alberti; S. Barry; P. Blanchard; P. Bosshard; R. Chavan; B. P. Duval; Y. V. Esipchuck; D. Fasel; A. Favre; S. Franke; I. Furno; P. Gorgerat; P.-F. Isoz; B. Joye; J. B. Lister; X. Llobet; J.-C. Magnin; P. Mandrin; A. Manini; B. Marlétaz; P. Marmillod; Y. Martin; J.-M. Mayor; J. Mlynar; C. Nieswand; P. J. Paris; A. Perez; R. A. Pitts; K. A. Razumova; A. Refke; E. Scavino; A. Sushkov; G. Tonetti; F. Troyon; W. Van Toledo; P. Vyas

1999-01-01

348

Results from the Phoenix Urban Heat Island (UHI) experiment: effects at the local, neighbourhood and urban scales  

NASA Astrophysics Data System (ADS)

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 façades 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 façade 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.

di Sabatino, S.; Leo, L. S.; Hedquist, B. C.; Carter, W.; Fernando, H. J. S.

2009-04-01

349

Biohydrogen production from CO-rich syngas via a locally isolated Rhodopseudomonas palustris PT.  

PubMed

Biohydrogen production through water–gas shift (WGS) reaction by a biocatalyst was conducted in batch fermentation. The isolated photosynthetic bacterium Rhodopseudomonas palustris PT was able to utilize carbon monoxide and simultaneously produce hydrogen. Light exposure was provided as an indispensable requirement for the first stage of bacterial growth, but throughout the hydrogen production stage, the energy requirement was met through the WGS reaction. At ambient pressure and temperature, the effect of various sodium acetate concentrations in presence of CO-rich syngas on cell growth, carbon monoxide consumption, and biohydrogen production was also investigated. Maximal efficiency of hydrogen production in response to carbon monoxide consumption was recorded at 86 % and the highest concentration of hydrogen at 33.5 mmol/l was achieved with sodium acetate concentration of 1.5 g/l. The obtained results proved that the local isolate; R. palustris PT, was able to utilize CO-rich syngas and generate biohydrogen via WGS reaction. PMID:24078148

Pakpour, Fatemeh; Najafpour, Ghasem; Tabatabaei, Meisam; Tohidfar, Masoud; Younesi, Habiboallah

2014-05-01

350

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

NASA Astrophysics Data System (ADS)

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.

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

351

Detailed measurements of local heat transfer coefficients in turbulent flow through smooth and rib-roughened serpentine passages with a 180° sharp bend  

Microsoft Academic Search

An experimental study is performed to investigate heat transfer and fluid flow in two straight, rectangular channels with a 180° sharp bend. Ribs are attached to two opposite walls with an angle of 90° or 60° to the flow. More than 450 thermocouples are used to monitor detailed distributions of local heat transfer coefficients over the four wall surfaces of

S. Mochizuki; A. Murata; R. Shibata; Wen-Jei Yang

1998-01-01

352

Genetic diversity of local geese of varying productivity and feather color in Kars  

Microsoft Academic Search

The local geese in the transition region between the Caucasus Mountains and Anatolia have economically significant differences\\u000a in productivity and are identified by four feather colors, white, black, piebald, and yellow. This study was undertaken to\\u000a determine the genetic structure, evolutionary relationships, and genetic diversity among these birds. DNA samples were obtained\\u000a from 100 animals, and 50 random primers were

Alparslan Kadir Devrim; Necati Kaya; Aysel Guven; Buket Kocer

2007-01-01

353

Heat shock factor-1 protein in heat shock factor-1 gene-transfected human epidermoid A431 cells requires phosphorylation before inducing heat shock protein-70 production.  

PubMed Central

Heat shock factor-1 (HSF1) is a transcriptional factor that binds to heat shock elements located on the promoter region of heat shock protein genes. The purpose of this study was to further investigate the regulation of the expression of the heat shock protein-70 (HSP-70) gene. The HSF1 gene was inserted into pCDNA3 plasmid and then transfected into human epidermoid A431 cells using the CaOP3 method. Control cells were transfected with vector alone. Expression of HSP-70, HSF1, and HSF2 genes and protein were determined. We found a significant increase in the expression of the HSF1 gene, but not HSP-70 and HSF2 genes, in the HSF1 gene-transfected cells. The amount of HSF1-heat shock element complex was significantly increased in both the nucleus and cytosol in HSF1 gene-transfected cells, indicating increased synthesis of HSF1. The amount of HSP-72 in these cells did not change. Therefore, overexpression of HSF1 protein failed to initiate transcription of the HSP-70 gene. Subsequently, we treated the cells with 1 microM PMA (a protein kinase C stimulator), and HSP-70 mRNA and protein were measured at 1 or 4 h of the treatment, respectively. The levels of both HSP-70 mRNA and HSP-72 protein were significantly increased in nontransfected and transfected cells; the levels of HSP-72 in HSF1 gene-transfected cells were greater than that found in the vector-transfected cells. The PMA-induced increase in HSP-72 protein peaked 8 h after treatment with PMA and returned to baseline levels at 72 h. This increase was blocked by a PKC inhibitor, staurosporine. After treatment with PMA, HSF1 translocated quickly from cytosol to nucleus. The results suggest that phosphorylation of newly synthesized HSF1 and possibly of other factors are necessary for the induction of HSP-72. Activation of PKC can cause phosphorylation of HSF1, which leads to an enhanced but transient increase in HSP-70 production.

Ding, X Z; Tsokos, G C; Kiang, J G

1997-01-01

354

Development of Naphthalene PLIF for Visualizing Ablation Products From a Space Capsule Heat Shield  

NASA Technical Reports Server (NTRS)

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.

Combs, C. S.; Clemens, N. T.; Danehy, P. M.

2014-01-01

355

[Local heating of murine skin by millimeter waves based on HBHE].  

PubMed

The authors deduced Gaussian function of millimeter wave power distribution, and built up a transient thermal multilayer model for the heating of murine skin by high power millimeter waves with finite volume method (FVM) based on HBHE in the present paper. We analyzed the calculated results and compared them with the results calculated by Pennes' equation and the experimental ones; found that the temperature calculated by HBHE was more reasonable. Especially under high power millimeter wave, the calculated results were basically consistent with the experimental ones, and the superiority of the theoretical model was confirmed. PMID:23016351

Hu, Shuang-Xi; Fan, Chun-Li; Yang, Li; Sun, Feng-Rui

2012-07-01

356

Millimeter Wave Detection of Localized Anomalies in the Space Shuttle External Fuel Tank Insulating Foam and Acreage Heat Tiles  

NASA Technical Reports Server (NTRS)

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.

Kharkovsky, S.; Case, J. T.; Zoughi, R.; Hepburn, F.

2005-01-01

357

Salicylic Acid: a natural inducer of heat production in arum lilies.  

PubMed

For more than 50 years the identity of "calorigen," the agent that triggers pronounced heat production in the flowers and inflorescences of some thermogenic plants, remained obscure. Mass spectroscopic analysis of highly purified calorigen extracted from the male flowers of Sauromatum guttatum Schott (voodoo lily) revealed the presence of 2-hydroxybenzoic (salicylic) acid. Application of salicylic acid at 0.13 microgram per gram (fresh weight) to sections of the upper part of the plant's immature spadix, known as the appendix, led to temperature increases of as much as 12 Celsius degrees. These increases duplicated, in both magnitude and timing, the temperature increases produced by the crude calorigen extract. The sensitivity of appendix tissue to salicylic acid increases daily with the approach of anthesis and is controlled by the photoperiod. Thus, at least in some Arum lilies, salicylic acid functions as an endogenous regulator of heat production. PMID:17834449

Raskin, I; Ehmann, A; Melander, W R; Meeuse, B J

1987-09-25

358

Developing natural convection in a fluid layer with localized heating and large viscosity variation  

SciTech Connect

Numerical simulations and laboratory experiments are used to elucidate aspects of transient natural convection in a magma chamber. The magma chamber is modeled as a horizontal fluid layer confined within an enclosure of square planform and heated from below by a strip heater centered on the lower boundary of the enclosure. The width of the strip heater and the depth of the fluid layer are one-fourth of the layer width. Corn syrup is used as the working fluid in order to approximate the large viscosity variation with temperature and the large Prandtl number typical of magma. The quiescent, uniform, fluid layer is subjected to instantaneous heating from the strip heater producing a transient flow which is dominated by two counter-rotating convective cells. Experimentally determined characteristics of the developing flow are compared with numerical simulations carried out with a finite element computer program. The results of numerical simulations are in essential agreement with experimental data. Differences between the numerical simulations and experimental measurements are conjectured to result from non-ideal effects present in the experiment which are difficult to represent accurately in a numerical simulation.

Hickox, C.E.; Chu, Tze Yao.

1991-01-01

359

Extreme heat reduces and shifts United States premium wine production in the 21st century  

PubMed Central

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 (>35°C) 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.

White, M. A.; Diffenbaugh, N. S.; Jones, G. V.; Pal, J. S.; Giorgi, F.

2006-01-01

360

Extreme heat reduces and shifts United States premium wine production in the 21st century.  

PubMed

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 (>35 degrees C) 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

White, M A; Diffenbaugh, N S; Jones, G V; Pal, J S; Giorgi, F

2006-07-25

361

BODY COMPOSITION AS A FACTOR GOVERNING THE BASAL HEAT PRODUCTION AND THE ENDOGENOUS NITROGEN EXCRETION  

Microsoft Academic Search

The heat production of warm-blooded animals is generally believed to be proportional to approximately the two-thirds power of body weight. It is also commonly assumed that animals with an excess of adipose tissue have a lower basal metabolic rate (B.M.R.) per unit body weight than those containing less fatty tissue. Recent work would seem to indicate that the endogenous urinary

URAL S. ASHWORTH; GEORGE R. COWGILL

362

Thermodynamic performance assessment of an ammonia–water Rankine cycle for power and heat production  

Microsoft Academic Search

In this paper, an ammonia–water based Rankine cycle is thermodynamically analyzed for renewable-based power production, e.g. solar, geothermal, biomass, oceanic-thermal, and nuclear as well as industrial waste heat. Due to the nature of the ammonia–water mixture, changes in its concentration allow thermodynamic cycles to adapt to fluctuations in renewable energy sources, which is an important advantage with respect to other

W. R. Wagar; C. Zamfirescu; I. Dincer

2010-01-01

363

Radiogenic heat production in the Variscan crust: new determinations and distribution models in Corsica (northwestern Mediterranean)  

Microsoft Academic Search

New heat-production values of Variscan volcanic rocks cropping out in the southern part of the Corsican batholith were determined in the laboratory by analysing uranium, thorium and potassium concentrations with gamma-ray spectrometry. They vary from a minimum of 0.2 for basalts to a maximum of 4.2 ?W m?3 for calc-alkaline granites. The Th\\/U ratio in Variscan granitoids is slightly higher

M. Verdoya; V. Pasquale; P. Chiozzi; I. T. Kukkonen

1998-01-01

364

Studies of the use of high-temperature nuclear heat from an HTGR for hydrogen production  

NASA Technical Reports Server (NTRS)

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.

Peterman, D. D.; Fontaine, R. W.; Quade, R. N.; Halvers, L. J.; Jahromi, A. M.

1975-01-01

365

Production of pyrolytic liquids from industrial sewage sludges in an induction-heating reactor.  

PubMed

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

Tsai, Wen-Tien; Chang, Jeng-Hung; Hsien, Kuo-Jung; Chang, Yuan-Ming

2009-01-01

366

Thermocapillary flows and interface deformations produced by localized laser heating in confined environment  

NASA Astrophysics Data System (ADS)

The deformation of a fluid-fluid interface due to the thermocapillary stress induced by a continuous Gaussian laser wave is investigated analytically. We show that the direction of deformation of the liquid interface strongly depends on the viscosities and the thicknesses of the involved liquid layers. We first investigate the case of an interface separating two different liquid layers while a second part is dedicated to a thin film squeezed by two external layers of same liquid. These results are predictive for applications fields where localized thermocapillary stresses are used to produce flows or to deform interfaces in presence of confinement, such as optofluidics.

Chraïbi, Hamza; Delville, Jean-Pierre

2012-03-01

367

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)

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.

Hippensteele, S. A.; Russell, L. M.; Torres, F. J.

1985-01-01

368

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)

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 STANS boundary layer code. Also, a leading edge separation bubble was revealed by thermal and flow visualization.

Hippensteele, S. A.; Russell, L. M.; Torres, F. J.

1985-01-01

369

Local heat-transfer measurements on a large scale-model turbine blade airfoil using a composite of a heater element and liquid crystals  

SciTech Connect

Local heat-transfer coefficients were experimentally mapped along the midchord of a five-times-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, which change color with temperature, and a heater sheet made of a carbon-impregnated paper, which 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/sup 5/ to 7.6 X 10/sup 5/. 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.

Hippensteele, S.A.; Russell, L.M.; Torres, F.J.

1985-10-01

370

3D slicing of radiogenic heat production in Bahariya Formation, Tut oil field, North-Western Desert, Egypt.  

PubMed

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 ?Wm(-3) to 2.2 ?Wm(-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 ?Wm(-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

Al-Alfy, I M; Nabih, M A

2013-03-01

371

Estimation of Soil Thermal Inertia and Ground Heat Flux Based on Maximum Entropy Production Hypothesis  

NASA Astrophysics Data System (ADS)

Ground heat flux is an important component of the energy balance at the terrestrial earth surface. This study focuses on the remote sensing of areal ground heat flux G. Before, Wang and Bras (1999) suggested a method to evaluate G based on the half-order time derivatives of soil surface temperature. The method required thermal inertia of surface layer Is, which should be estimated using soil thermal properties or calculated with a few measurements of G for calibration. However, areal representative Is was difficult to obtain for the complexity of areal surface composition and lack of the direct methods of G measurement. The author developed a novel method to estimate areal Is and G, for which remotely sensible net radiation and surface temperature were only used. It depended on the assumptions that energy sharing of net radiation obeyed the maximum entropy production hypothesis in calm nights and then latent heat flux was insignificant. Validation showed thermal inertia of air Ia at the soil surface did not agree well with the theory of Wang and Bras (2009). A new empirical equation of Ia and sensitive heat flux relationship was proposed. Using this equation, net radiation was divided into sensitive heat flux and ground heat flux, and Is was obtained. For several days, systematic changes of Is could not be detected. That is, the thermal inertia of surface soil layer could be treated as a constant if not for remarkable changes of soil wetness. The method should be useful for remote sensing of other objects, for instance, soil water condition and evapotranspiration.

Kiyosawa, H.

2013-12-01

372

Human hnRNP Q re-localizes to cytoplasmic granules upon PMA, thapsigargin, arsenite and heat-shock treatments  

SciTech Connect

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.

Quaresma, Alexandre J.C. [Brazilian Synchrotron Light Laboratory - LNLS, 13083-970, Campinas, SP (Brazil); Bressan, G.C. [Brazilian Synchrotron Light Laboratory - LNLS, 13083-970, Campinas, SP (Brazil); Institute of Biology, University of Campinas - UNICAMP, 13083-970, Campinas, SP (Brazil); Gava, L.M. [Institute of Biology, University of Campinas - UNICAMP, 13083-970, Campinas, SP (Brazil); Institute of Chemistry, University of Campinas, CEP 13083-970, Campinas, SP (Brazil); Lanza, D.C.F. [Brazilian Synchrotron Light Laboratory - LNLS, 13083-970, Campinas, SP (Brazil); Institute of Biology, University of Campinas - UNICAMP, 13083-970, Campinas, SP (Brazil); Ramos, C.H.I [Institute of Chemistry, University of Campinas, CEP 13083-970, Campinas, SP (Brazil); Kobarg, Joerg [Brazilian Synchrotron Light Laboratory - LNLS, 13083-970, Campinas, SP (Brazil); Institute of Biology, University of Campinas - UNICAMP, 13083-970, Campinas, SP (Brazil)], E-mail: jkobarg@lnls.br

2009-04-01

373

Engineered heat treated methanogenic granules: a promising biotechnological approach for extreme thermophilic biohydrogen production.  

PubMed

In the present study, two granular systems were compared in terms of hydrogen production rate, stability and bacterial diversity under extreme thermophilic conditions (70 degrees C). Two EGSB reactors were individually inoculated with heat treated methanogenic granules (HTG) and HTG amended with enrichment culture with high capacity of hydrogen production (engineered heat treated methanogenic granules - EHTG), respectively. The reactor inoculated with EHTG (R(EHTG)) attained a maximum production rate of 2.7l H(2)l(-1)day(-1) in steady state. In comparison, the R(HTG) containing the HTG granules was very unstable, with low hydrogen productions and only two peaks of hydrogen (0.8 and 1.5l H(2)l(-1)day(-1)). The presence of active hydrogen producers in the R(EHTG) system during the reactor start-up resulted in the development of an efficient H(2)-producing bacterial community. The results showed that "engineered inocula" where known hydrogen producers are co-inoculated with HTG is an efficient way to start up biohydrogen-producing reactors. PMID:20709532

Abreu, Angela A; Alves, Joana I; Pereira, M Alcina; Karakashev, Dimitar; Alves, M Madalena; Angelidaki, Irini

2010-12-01

374

Effect of gold nanoparticles in the local heating of skin tumors induced by phototherapy  

NASA Astrophysics Data System (ADS)

During optical therapies, several types of interaction between the optical radiation and the target tissue can occur. The application of different power densities and the variation of the exposure time can cause from photochemical reactions to photodisruption. Photothermal therapy (PTT) is based in the thermal interactions, where the biological injury is provoked by a given increase of their temperature during the exposition to the optical source. Another treatment option very extended in several clinical fields due to its promising results is Photodynamic Therapy. This treatment modality is based in photochemical reactions where it is also required oxygen and the administration of a photosensitive substance known as photosensitizer. The use of nanotechnology in optical therapeutic techniques, constitutes a novel promising treatment strategy. Specifically, gold nanoparticles can improve different issues related to the transport of photosensitizers or the light energy absorption and the subsequent heat generation. This work focuses in the effects that can produce the use of gold nanoparticles in Photothermal and Photodynamic Therapies applied to skin diseases commonly treated by means of these techniques. We present a thermal model that permits to calculate the temperature distribution in different kinds of pathological dermatological tissues depending on the optical power provided by the optical source. The results obtained permit to compare the thermal injury produced depending on not only the provided power but also the type of pathology and the incorporation or not of gold nanoparticles in the target tissue.

Salas-García, I.; Fanjul-Vélez, F.; Ortega-Quijano, N.; Lavín-Castanedo, A.; Mingo-Ortega, P.; López-Escobar, M.; Arce-Diego, J. L.

2011-06-01

375

Genetic variations alter production and behavioral responses following heat stress in 2 strains of laying hens.  

PubMed

Genetic differences alter the type and degree of hens' responses and their ability to adapt to a stressor. This study examined the effects of genotypic variations on the productivity and behavior of laying hens following heat stress (HS). Two strains of White Leghorn hens were used: DXL (Dekalb XL), a commercial strain individually selected for egg production and KGB (kind, gentle bird), a strain selected for high group productivity and survivability. Ninety hens (48 DXL and 42 KGB) at 28 wk of age were randomly assigned to either a hot (H: mean = 32.6°C) or control (C: mean = 24.3°C) treatment and housed in pairs by strain for 9 d. Egg production and quality, behavior, body and organ weights, and circulating hormone concentrations were measured. Heat-stressed hens had lower egg production [adjusted (adj) P < 0.001] than their respective controls. Among H-DXL hens, egg weight tended to be reduced at d 1 and was reduced at d 9 (adj P = 0.007), but was reduced only at d 9 among H-KGB hens (adj P = 0.007). Eggshell thickness was also reduced among H hens at d 9 (adj P = 0.007), especially among H-KGB hens (adj P = 0.01). Plasma triiodothyronine concentration was reduced among H-hens (adj P = 0.01), especially among H-DXL hens (adj P = 0.01). Neither temperature nor strain affected the plasma thyroxine and plasma and yolk corticosterone concentrations. Heat-stressed hens spent less time walking (adj P = 0.001) and more time drinking (adj P = 0.007) and resting (adj P = 0.001) than C-hens. The results indicate that although HS reduced production and caused behavioral changes among hens from both strains, the responses differed by genotype. The data provide evidence that genetic selection is a useful strategy for reducing HS response in laying hens. The results provide insights for conducting future studies to develop heat-resistant strains to improve hen well-being, especially under the current commercial conditions. PMID:23300291

Mack, L A; Felver-Gant, J N; Dennis, R L; Cheng, H W

2013-02-01

376

Radiation heat savings in polysilicon production: Validation of results through a CVD laboratory prototype  

NASA Astrophysics Data System (ADS)

This work aims at a deeper understanding of the energy loss phenomenon in polysilicon production reactors by the so-called Siemens process. Contributions to the energy consumption of the polysilicon deposition step are studied in this paper, focusing on the radiation heat loss phenomenon. A theoretical model for radiation heat loss calculations is experimentally validated with the help of a laboratory CVD prototype. Following the results of the model, relevant parameters that directly affect the amount of radiation heat losses are put forward. Numerical results of the model applied to a state-of-the-art industrial reactor show the influence of these parameters on energy consumption due to radiation per kilogram of silicon produced; the radiation heat loss can be reduced by 3.8% when the reactor inner wall radius is reduced from 0.78 to 0.70 m, by 25% when the wall emissivity is reduced from 0.5 to 0.3, and by 12% when the final rod diameter is increased from 12 to 15 cm.

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

2013-07-01

377

Renoprotective effects of Maillard reaction products generated during heat treatment of ginsenoside Re with leucine.  

PubMed

The structural change of ginsenoside and the generation of Maillard reaction products (MRPs) are important to the increase in the biological activities of Panax ginseng. This study was carried out to identify the renoprotective active component of P. ginseng using the Maillard reaction model experiment with ginsenoside Re and leucine. Ginsenoside Re was gradually converted into less-polar ginsenosides Rg2, Rg6 and F4 by heat-processing, followed by separation of the glucosyl moiety at carbon-20. The free radical-scavenging activity of the ginsenoside Re-leucine mixture was increased by heat-processing. The improved free radical-scavenging activity by heat-processing was mediated by the generation of MRPs from the reaction of glucose and leucine. The cisplatin-induced LLC-PK1 renal cell damage was also significantly reduced by treatment with MRPs. Moreover, the heat-processed glucose-leucine mixture (major MRPs from the ginsenoside Re-leucine mixture) showed protective effects against cisplatin-induced oxidative renal damage in rats through the inhibition of caspase-3 activation. PMID:24054220

Kim, Ji Hoon; Han, Im-Ho; Yamabe, Noriko; Kim, Young-Joo; Lee, Woojung; Eom, Dae-Woon; Choi, Pilju; Cheon, Gab Jin; Jang, Hyuk-Jai; Kim, Su-Nam; Ham, Jungyeob; Kang, Ki Sung

2014-01-15

378

Heat removal from high temperature tubular solid oxide fuel cells utilizing product gas from coal gasifiers.  

SciTech Connect

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 .

Parkinson, W. J. (William Jerry),

2003-01-01

379

Finite Volume schemes on unstructured grids for non-local models: Application to the simulation of heat transport in plasmas  

SciTech Connect

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.

Goudon, Thierry, E-mail: thierry.goudon@inria.fr [Team COFFEE, INRIA Sophia Antipolis Mediterranee (France) [Team COFFEE, INRIA Sophia Antipolis Mediterranee (France); Labo. J.A. Dieudonne CNRS and Univ. Nice-Sophia Antipolis (UMR 7351), Parc Valrose, 06108 Nice cedex 02 (France); Parisot, Martin, E-mail: martin.parisot@gmail.com [Project-Team SIMPAF, INRIA Lille Nord Europe, Park Plazza, 40 avenue Halley, F-59650 Villeneuve d'Ascq cedex (France)] [Project-Team SIMPAF, INRIA Lille Nord Europe, Park Plazza, 40 avenue Halley, F-59650 Villeneuve d'Ascq cedex (France)

2012-10-15

380

RF plasma production and heating below ion-cyclotron frequencies in Uragan torsatrons  

NASA Astrophysics Data System (ADS)

In the IPP-Kharkiv there are two torsatrons (stellarators) in operation, and in both of them Alfvén resonance heating under high-k? conditions is used. This method of heating is advantageous for small-size devices, since in contrast to the minority and second-harmonic heating it can be realized at lower plasma densities. A series of experiments has been performed at the Uragan-3M torsatron with an aim to investigate the features of the discharge with a three-half-turn antenna. Electron temperatures in the \\bar {T}_e =0.2{{--}}0.5\\,keV range are achieved at plasma densities \\bar {n}_e \\approx (0.5{{--}}1.5)\\times 10^{13}\\,cm^{-3} . The plasma energy content has increased by a factor of 2 with respect to the plasma produced with the frame antenna. A new four-strap shielded antenna has been manufactured and installed in the Uragan-2M. A high-frequency discharge for wall conditioning is introduced in the Uragan-2M torsatron. The discharge is sustained by a specially designed small frame antenna, and efficient hydrogen dissociation is achieved. A self-consistent model has been developed for simulation of plasma production in ICRF. The model includes a set of particle and energy-balance equations for the electrons, and the boundary problem for the Maxwell equations. The first calculation results on RF plasma production in the Uragan-2M stellarator with the frame-type antenna are presented.

Moiseenko, V. E.; Berezhnyj, V. L.; Bondarenko, V. N.; Burchenko, P. Ya.; Castejón, F.; Chechkin, V. V.; Chernyshenko, V. Ya.; Dreval, M. B.; Garkusha, I. E.; Glazunov, G. P.; Grigor'eva, L. I.; Hartmann, D.; Hidalgo, C.; Koch, R.; Konovalov, V. G.; Kotsubanov, V. D.; Kramskoi, Ye. D.; Kulaga, A. E.; Lozin, A. V.; Lyssoivan, A. I.; Mironov, V. K.; Mysiura, I. N.; Pavlichenko, R. O.; Pashnev, V. K.; Romanov, V. S.; Shapoval, A. N.; Skibenko, A. I.; Slavnyi, A. S.; Sorokovoy, E. L.; Stadnik, Yu. S.; Taran, V. S.; Tereshin, V. I.; Voitsenya, V. S.

2011-08-01

381

Changes in the localization and levels of starch and lipids in cambium and phloem during cambial reactivation by artificial heating of main stems of Cryptomeria japonica trees  

PubMed Central

Background and Aims Cambial reactivation in trees occurs from late winter to early spring when photosynthesis is minimal or almost non-existent. Reserve materials might be important for wood formation in trees. The localization and approximate levels of starch and lipids (as droplets) and number of starch granules in cambium and phloem were examined from cambial dormancy to the start of xylem differentiation in locally heated stems of Cryptomeria japonica trees in winter. Methods Electric heating tape was wrapped on one side of the stem of Cryptomeria japonica trees at breast height in winter. The localization and approximate levels of starch and lipids (as droplets) and number of starch granules were determined by image analysis of optical digital images obtained by confocal laser scanning microscopy. Key Results Localized heating induced earlier cambial reactivation and xylem differentiation in stems of Cryptomeria japonica, as compared with non-heated stems. There were clear changes in the respective localizations and levels of starch and lipids (as droplets) determined in terms of relative areas on images, from cambial dormancy to the start of xylem differentiation in heated stems. In heated stems, the levels and number of starch granules fell from cambial reactivation to the start of xylem differentiation. There was a significant decrease in the relative area occupied by lipid droplets in the cambium from cambial reactivation to the start of xylem differentiation in heated stems. Conclusions The results showed clearly that the levels and number of storage starch granules in cambium and phloem cells and levels of lipids (as droplets) in the cambium decreased from cambial reactivation to the start of xylem differentiation in heated stems during the winter. The observations suggest that starch and lipid droplets might be needed as sources of energy for the initiation of cambial cell division and the differentiation of xylem in Cryptomeria japonica.

Begum, Shahanara; Nakaba, Satoshi; Oribe, Yuichiro; Kubo, Takafumi; Funada, Ryo

2010-01-01

382

Localization of pNT22 70 kDa heat shock cognate-like protein in the plasma membrane.  

PubMed

It has been argued that 70 kDa heat shock cognate (hsc73)-like molecules may be expressed on the surface of certain cells, but direct evidence of this has yet to be found. To clarify whether this molecule belongs to hsc73 itself, the membrane protein fraction of Daudi cells was isolated by Triton X-114 phase separation and the reactivity of this membrane protein fraction was assessed with monoclonal antibodies (mAbs) which react with 70 kDa heat shock protein (hsp) family, i.e., NT22, A15 and 3A3. In western blotting analysis, mAb NT22-defined protein (pNT22) was clearly detected as a membrane protein of Daudi cells with an approximate molecular size of 70 kDa, whereas pNT22 was not recognized by anti-cytoplasmic hsc73/hsp72 mAbs A15 or 3A3. By using deleted recombinant hsc73 proteins, it was determined that mAb NT22 recognizes the N-terminal 350-372 amino acid stretches of the hsc73 protein. mAb NT22 also reacted with the cell surface protein of Daudi cells in FACS analysis. Taken together, our present data strongly suggest that pNT22 may be a novel hsc73-like protein that is localized in the plasma membrane. PMID:9706404

Hirai, I; Sato, N; Qi, W; Ohtani, S; Torigoe, T; Kikuchi, K

1998-06-01

383

Study on transient local entropy generation in pulsating fully developed laminar flow through an externally heated pipe  

NASA Astrophysics Data System (ADS)

This study presents the investigation of transient local entropy generation rate in pulsating fully developed laminar flow through an externally heated pipe. The flow inlet to the pipe is considered as pulsating at a constant period and amplitude (only the velocity oscillates). The simulations are extended to include different pulsating flow cases (sinusoidal flow, step flow, and saw-down flow). To determine the effects of the mean velocity, the period and the amplitude of the pulsating flow on the entropy generation rate, the pulsating flow is examined for various cases of these parameters. Two-dimensional flow and temperature fields are computed numerically with the help of the fluent computational fluid dynamics (CFD) code. In addition to this CFD code, a computer program has been developed to calculate numerically the entropy generation and other thermodynamic parameters by using the results of the calculations performed for the flow and temperature fields. In all investigated cases, the irreversibility due to the heat transfer dominates. The step flow constitutes the highest temperature (about 919 K) and generates the highest total entropy rate (about 0.033 W/K) within the pipe. The results of this study indicate that in the considered situations, the inverse of square of temperature (1/ T 2) is more dominant on the entropy generation than the temperature gradients, and that the increase of the mean velocity of the pulsating flow has an adverse effect on the ratio of the useful energy transfer rate to irreversibility rate.

Yap?c?, Hüseyin; Kayata?, Nesrin; Ba?türk, Gamze; Kahraman, Nafiz

2006-11-01

384

Natural convective heat and mass transfer of water with corrosion products at super-critical pressures under cooling conditions  

Microsoft Academic Search

A numerical study is reported of laminar natural convective heat and mass transfer on a vertical cooled plate for water containing\\u000a metal corrosion products at super-critical pressures. The influence of variable properties at super-critical pressures on\\u000a natural convection has been analyzed. The difference between heat and mass transfer under cooling or heating conditions is\\u000a also discussed and some correlations for

Pei-Xue Jiang; Ze-Pei Ren; Bu-Xuan Wang

1993-01-01

385

Improved irradiances for use in ocean heating, primary production, and photo-oxidation calculations.  

PubMed

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

Mobley, Curtis D; Boss, Emmanuel S

2012-09-20

386

Thermal Gains Through Collective Metabolic Heat Production in Social Caterpillars of Eriogaster lanestris  

NASA Astrophysics Data System (ADS)

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.

Ruf, C.; Fiedler, K.

387

Skylab and solar exploration. [chromosphere-corona structure, energy production and heat transport processes  

NASA Technical Reports Server (NTRS)

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.

Von Puttkamer, J.

1973-01-01

388

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

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

Lachenbruch, A. H.

1980-01-01

389

Citrate-capped gold nanoparticle electrophoretic heat production in response to a time-varying radiofrequency electric-field  

PubMed Central

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.

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

390

The vertical distribution of radiogenic heat production in the Precambrian Crust of Norway and Sweden: Geothermal implications  

Microsoft Academic Search

The present geology of southern Scandinavia offers the unique opportunity to sample deep and intermediate levels from the same crustal section for both heat flow and heat production. In the central part ot southern Norway, amphibolite facies terranes appear to lie on top of the same deeper crustal formations which crop out on their western and eastern margins. An extensive

Christophe Pinet; Claude Jaupart

1987-01-01

391

Applications of high-temperature solar heat to the production of selected fuels and chemicals  

SciTech Connect

An attempt is made to judge whether solar heat in the 500 K to 2500 K temperature range might be economical for some important fuel- and chemical-production processes. Previous work in related areas is reviewed and the chemicals aluminum oxide (and bauxite), calcium sulfate (and gypsum), and calcium oxide (lime) chosen for detailed study. In addition to reviewing the energy needs of the more common bulk chemicals, several innovative processes requiring heat in the 1500 to 2500 K range were investigated. Hydrogen production by several thermochemical means, carbon monoxide production by thermochemical and direct thermal dissociation, and nitrogen fixation by direct thermal reaction of nitrogen and oxygen in air were considered. The engineering feasibility of the processes is discussed. The problem of matching the conventional and innovative processes to a high-temperature solar supply is studied. Some solar-thermal power plants of current designs are examined and several advanced concepts of highly concentrating systems are considered for very high-temperature applications. Conclusions and recommendations are presented.

Beall, S.E. Jr.; Bamberger, C.E.; Goeller, H.A.

1981-07-01

392

A comparison between the effects of artificial land cover and anthropogenic heat on a localized heavy rain event in 2008 in Zoshigaya, Tokyo, Japan  

NASA Astrophysics Data System (ADS)

5 August 2008, a localized heavy rainfall event caused a rapid increase in drainpipe discharge, which killed five people working in a drainpipe near Zoshigaya, Tokyo. This study compared the effects of artificial land cover and anthropogenic heat on this localized heavy rainfall event based on three ensemble experiments using a cloud-resolving model that includes realistic urban features. The first experiment CTRL (control) considered realistic land cover and urban features, including artificial land cover, anthropogenic heat, and urban geometry. In the second experiment NOAH (no anthropogenic heat), anthropogenic heat was ignored. In the third experiment NOLC (no land cover), urban heating from artificial land cover was reduced by keeping the urban geometry but with roofs, walls, and roads of artificial land cover replaced by shallow water. The results indicated that both anthropogenic heat and artificial land cover increased the amount of precipitation and that the effect of artificial land cover was larger than that of anthropogenic heat. However, in the middle stage of the precipitation event, the difference between the two effects became small. Weak surface heating in NOAH and NOLC reduced the near-surface air temperature and weakened the convergence of horizontal wind and updraft over the urban areas, resulting in a reduced rainfall amount compared with that in CTRL.

Souma, Kazuyoshi; Tanaka, Kenji; Suetsugi, Tadashi; Sunada, Kengo; Tsuboki, Kazuhisa; Shinoda, Taro; Wang, Yuqing; Sakakibara, Atsushi; Hasegawa, Koichi; Moteki, Qoosaku; Nakakita, Eiichi

2013-10-01

393

Biogeographic affinity helps explain productivity-richness relationships at regional and local scales  

USGS Publications Warehouse

The unresolved question of what causes the observed positive relationship between large-scale productivity and species richness has long interested ecologists and evolutionists. Here we examine a potential explanation that we call the biogeographic affinity hypothesis, which proposes that the productivity-richness relationship is a function of species' climatic tolerances that in turn are shaped by the earth's climatic history combined with evolutionary niche conservatism. Using botanical data from regions and sites across California, we find support for a key prediction of this hypothesis, namely, that the productivity-species richness relationship differs strongly and predictably among groups of higher taxa on the basis of their biogeographic affinities (i.e., between families or genera primarily associated with north-temperate, semiarid, or desert zones). We also show that a consideration of biogeographic affinity can yield new insights on how productivity-richness patterns at large geographic scales filter down to affect patterns of species richness and composition within local communities. ?? 2007 by The University of Chicago. All rights reserved.

Harrison, S.; Grace, J. B.

2007-01-01

394

Expression and Localization of TRK-Fused Gene Products in the Rat Brain and Retina  

PubMed Central

The TRK-fused gene (TFG in human, Tfg in rat) was originally identified in human papillary thyroid cancer as a chimeric form of the NTRK1 gene. It has been reported that the gene product (TFG) plays a role in regulating phosphotyrosine-specific phosphatase-1 activity. However, no information regarding the localization of Tfg in rat tissues is available. In this study, we investigated the expression of Tfg mRNA in normal rat tissues using reverse transcription-polymerase chain reaction (RT-PCR). We also produced an antibody against Tfg gene products and examined the localization of TFG in the rat brain and retina. The RT-PCR experiments demonstrated that two types of Tfg mRNA were expressed in rat tissues: the conventional form of Tfg (cTfg) and a novel variant form, retinal Tfg (rTfg). RT-PCR analyses demonstrated that cTfg was ubiquitously expressed in rat tissues, while rTfg was predominantly expressed in the brain and retina. Western blot analysis demonstrated two bands with molecular weights of about 30 kDa and 50 kDa in the rat brain. Immunohistochemistry indicated that TFG proteins were predominantly expressed by neurons in the brain. In the rat retina, intense TFG-immunoreactivity was detected in the layer of rods and cones and the outer plexiform layer.

Maebayashi, Hisae; Takeuchi, Shigako; Masuda, Chiaki; Makino, Satoshi; Fukui, Kenji; Kimura, Hiroshi; Tooyama, Ikuo

2012-01-01

395

Modelling Hydraulic and Thermal Responses in a Benchmark for Deep Geothermal Heat Production  

NASA Astrophysics Data System (ADS)

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

Holzbecher, E.; Oberdorfer, P.

2012-04-01

396

Dynamics and localization of H2O2 production in elicited plant cells.  

PubMed

H(2)O(2) produced in plant cells plays a dual role. In addition to its antimicrobial effect, it also acts as a secondary messenger initiating and modulating responses of plants exposed to unfavorable external signals. A suspension culture of Rubia tinctorum cells challenged with elicitors was used as a model system to investigate H(2)O(2) formation. Cellular H(2)O(2) was measured by a modified titanium(IV) method, while that in the medium was detected with scopoletin fluorescence. Localization of H(2)O(2) production at the ultrastructural level was carried out by the CeCl(3) reaction. A fungal elicitor induced H(2)O(2) production with transient maxima, the first of which appeared 4 min after treatment. Three subsequent maxima appeared in the cells up to 48 h after treatment. Exposure of cells to exogenous jasmonic acid and salicylic acid also changed the H(2)O(2) concentration maxima over 48 h; however, their timing was slightly shifted. Fungal-elicitor, jasmonic acid, and salicylic acid treatments had different effects on the H(2)O(2) concentration in the medium. Ultrastructural investigations revealed that electron-dense precipitates were present at the plasmalemma and in some nearby vesicular cytoplasmic structures 30 min after treatment. Later samples showed cytochemical-precipitate accumulation in the cell walls. These deposits appeared to be local and independent of the direction of the external signal. We could not detect the presence of H(2)O(2) in peroxisomes, mitochondria, plastids, or the central vacuolar space. Electron energy loss spectroscopy investigations distinguished between the cerium-containing precipitates and other electrondense particles, thereby proving that H(2)O(2) generation occurs locally. PMID:17351735

Bóka, K; Orbán, N; Kristóf, Z

2007-01-01

397

The measurement of local wall heat transfer in stationary u-ducts of strong curvature, with smooth and rib-roughened walls  

SciTech Connect

The paper presents some of the authors recent investigations of convective heat transfer in flow through stationary passages relevant to gas turbine blade-cooling applications. The main objective of this effort is to produce local heat transfer data for CFD validation. Local Nusselt number measurements in flows through round-ended U-bends of square cross section, with and without artificial wall roughness, are presented. Their earlier LDA measurements of flows through these passages are first briefly reviewed and then the liquid-crystal technique for the measurement of local wall heat transfer inside passages of complex geometries is presented. Tightly curved U-bends generate strong secondary motion and cause flow separation at the bend exit, which substantially raises turbulence levels. Wall heat transfer is significantly increased, especially immediately downstream of the U-bend, where it is over two times higher than in a straight duct. The local heat transfer coefficient around the perimeter of the passage is also found to vary considerably because of the curvature-induced secondary motion. The introduction of surface ribs results in a further increase in turbulence levels, a reduction in the size of the curvature-induced separation bubble, and a complex flow development after the bend exit with additional separation regions along the outer wall. Heat transfer levels in the straight sections are more than doubled by the introduction of ribs. The effects of the bend on the overall levels of Nusselt number are not as strong as in the smooth U-bend, but are still significant. The effects of the bend on the perimetral variation of local heat transfer coefficients within the ribbed downstream section are also substantial.

Iacovides, H.; Jackson, D.C.; Kelemenis, G.; Launder, B.E.

2000-04-01

398

Compilation of Data on Radionuclide Data for Specific Activity, Specific Heat and Fission Product Yields  

SciTech Connect

This compilation was undertaken to update the data used in calculation of curie and heat loadings of waste containers in the Solid Waste Management Facility. The data has broad general use and has been cross-checked extensively in order to be of use in the Materials Accountability arena. The fission product cross-sections have been included because they are of use in the Environmental Remediation and Waste Management areas where radionuclides which are not readily detectable need to be calculated from the relative fission yields and material dispersion data.

Gibbs, A.; Thomason, R.S.

2000-09-05

399

Enhanced loss of fusion products during mode conversion heating in TFTR  

SciTech Connect

Ion Bernstein waves (IBWS) have been generated by mode conversion of ion cyclotron range of frequency (ICRF) fast waves in TFTR. The loss rate of fusion products in these discharges can be large, up to 10 times the first orbit loss rate. The losses are observed at the passing/trapped boundary, indicating that passing particles are being moved onto loss orbits either by increase of their v{perpendicular} due to the wave, by outward transport in minor radius, or both. The lost particles appear to be DD fusion produced tritons heated to {approximately}1.5 times their birth energy.

Darrow, D.S.; Majeski, R.; Fisch, N.J.; Heeter, R.F.; Herrmann, H.W.; Herrmann, M.C.; Zarnstorff, M.C.; Zweben, S.J.

1995-07-01

400

Fission product transport analysis in a loss of decay heat removal accident at Browns Ferry  

SciTech Connect

This paper summarizes an analysis of the movement of noble gases, iodine, and cesium fission products within the Mark-I containment BWR reactor system represented by Browns Ferry Unit 1 during a postulated accident sequence initiated by a loss of decay heat removal (DHR) capability following a scram. The event analysis showed that this accident could be brought under control by various means, but the sequence with no operator action ultimately leads to containment (drywell) failure followed by loss of water from the reactor vessel, core degradation due to overheating, and reactor vessel failure with attendant movement of core debris onto the drywell floor.

Wichner, R.P.; Weber, C.F.; Hodge, S.A.; Beahm, E.C.; Wright, A.L.

1984-01-01

401

Global versus local environmental impacts of grazing and confined beef production systems  

NASA Astrophysics Data System (ADS)

Carbon footprint is a key indicator of the contribution of food production to climate change and its importance is increasing worldwide. Although it has been used as a sustainability index for assessing production systems, it does not take into account many other biophysical environmental dimensions more relevant at the local scale, such as soil erosion, nutrient imbalance, and pesticide contamination. We estimated carbon footprint, fossil fuel energy use, soil erosion, nutrient imbalance, and risk of pesticide contamination for five real beef background-finishing systems with increasing levels of intensification in Uruguay, which were combinations of grazing rangelands (RL), seeded pastures (SP), and confined in feedlot (FL). Carbon footprint decreased from 16.7 (RL-RL) to 6.9 kg (SP-FL) CO2 eq kg body weight-1 (BW; ‘eq’: equivalent). Energy use was zero for RL-RL and increased up to 17.3 MJ kg BW-1 for SP-FL. Soil erosion values varied from 7.7 (RL-RL) to 14.8 kg of soil kg BW-1 (SP-FL). Nitrogen and phosphorus nutrient balances showed surpluses for systems with seeded pastures and feedlots while RL-RL was deficient. Pesticide contamination risk was zero for RL-RL, and increased up to 21.2 for SP-FL. For the range of systems studied with increasing use of inputs, trade-offs were observed between global and local environmental problems. These results demonstrate that several indicators are needed to evaluate the sustainability of livestock production systems.

Modernel, P.; Astigarraga, L.; Picasso, V.

2013-09-01

402

Carbonaceous material for production of hydrogen from low heating value fuel gases  

DOEpatents

A process for the catalytic production of hydrogen, from a wide variety of low heating value fuel gases containing carbon monoxide, comprises circulating a carbonaceous material between two reactors--a carbon deposition reactor and a steaming reactor. In the carbon deposition reactor, carbon monoxide is removed from a fuel gas and is deposited on the carbonaceous material as an active carbon. In the steaming reactor, the reactive carbon reacts with steam to give hydrogen and carbon dioxide. The carbonaceous material contains a metal component comprising from about 75% to about 95% cobalt, from about 5% to about 15% iron, and up to about 10% chromium, and is effective in suppressing the production of methane in the steaming reactor.

Koutsoukos, Elias P. (Los Angeles, CA)

1989-01-01

403

Increased heat production proportional to oxygen consumption in human neutrophils activated with phorbol-12-myristate-13-acetate  

Microsoft Academic Search

The heat produced by neutrophils was measured with a flow microcalorimeter. O2 consumption, ATP concentration, lactic acid production and14CO2 production from oxidation of [1-14C]-glucose [6-14C]-glucose and [U-14C]-glucose were evaluated. Experiments were also carried out in the presence of the metabolic inhibitors,N-ethylmaleimide and NaF. Heat effects were correlated to the enthalpy change of aerobic and anaerobic glucose catabolism.\\u000a Two different heat

Costantino Eftimiadi; Giovanni Rialdi

1982-01-01

404

The role of radiogenic heat production in the generation of ultra high temperature crustal metamorphism  

NASA Astrophysics Data System (ADS)

How the Earth’s crust can reach temperatures greater than 900°C at depths less than 40 km to produce ultrahigh temperature (UHT) metamorphism is a question exercising the minds of many researchers. Many models of continental geothermal gradients fail to account for this type of metamorphism yet natural examples of these rocks are being identified more frequently in orogenic belts around the world. UHT metamorphism is best preserved in rocks of sedimentary origin. This is in part because sedimentary rocks have chemical compositions that generate distinctive mineral phases under conditions of extreme temperature, but there also is a strong indication that this style of metamorphism is often associated with tectonic inversion of a sedimentary basin. It is widely accepted that such high geothermal gradients require thickening of crustal rocks that are either already anomalously hot, or have the potential to become so through elevated concentrations of U, Th and K. The applicability of these models hinges on two key factors (1) that there is a threshold enrichment of the relevant crustal column in U, Th and K and (2) the crust has enough time to respond conductively to the heat generated through the radioactive decay of these elements. In this presentation we will examine these two factors in an ideal natural laboratory, the Madurai Block of the Southern Granulite Terrane, India. We will constrain the duration of high-geothermal metamorphism through the application of in-situ Sensitive High Resolution Ion Probe (SHRIMP) geochronology linked to the development of UHT mineral assemblages. We will also present 1D numerical models for the temporal evolution of geothermal gradients in these rocks. Our models couple the temperature dependence of thermal conductivity and heat capacity from recent studies with in-situ radiogenic heat production measurements from lithologies within the Madurai Block and integrate the effect of the consumption of heat due to the initiation of partial melting. Geotherms calculated at 5, 10, 20, 40, 60, 80 and 120 Myr after crustal thickening for a pre-thickened uniform distribution of heat production of 2.5 ?m-3 in the upper 20 km and 0.4 ?m-3 from 20 - 35 km.

Clark, C.; Healy, D.

2009-12-01

405

Effect of cubic and planar collective and localized modes on the specific heat of C 60 fullerite for 0.2 ? T ? 300 K  

NASA Astrophysics Data System (ADS)

A dynamical model for C 60 polycrystalline fullerite is suggested to explain successfully the recent experimentally observed seven orders of variation in its specific heat for 0.2 ? T ? 300 K. The collective translational modes have both cubic and planar characters which yield correct T3 dependence of the observed specific heat for T < 1 K and over 60% contribution of the total specific heat for T ? 100 K. Other localized modes of the buckyballs: librational, orientational diffusive, tunneling and intramolecular vibrational, contribute significantly in different ranges of temperatures. It appears that surface modes persist in curled up graphite sheets that form fullerenes.

Tewari, S. P.; Silotia, Poonam; Bera, Kakoli

1998-05-01

406

Vinegar production from Togolese local variety Mangovi of Mango mangifera indica Linn. (Anacardiaceae).  

PubMed

The present study aimed to access for the physiochemical parameters of vinegar production through Togolese local variety Mangovi of mango Mangifera indica juice fermentation. The juice was fermented successively by Saccharomyces cerevisisae and acetic bacteria. The levels of ethanol and acetic acid in the juice during the production of vinegar were monitored by gas chromatography and titrimetry methods, respectively. The physiological state of the yeast Saccharomyces cerevisiae L2056 was determined by flow cytometry using a dual fluorescent labeling of diacetate carboxy-fluorescein (CFDA) and propidium iodide. The results indicated that 200 mL of mango juice, sugar content 20 Brix, set in alcoholic fermentation with 10(6) yeast cells produced 22.4 g L(-1) ethanol in 72 h. Acetic fermentation transformed 93% of this ethanol to acetic acid in 288 h. Twenty-four hours after the beginning of alcoholic fermentation, 91% of cells were viable, 8.85% were stressed and 0.05% died. After 24 h of acetic fermentation, viable, stressed and dead cells were 45, 12 and 39%, respectively; corresponding to the passage of acetic vinegar level from 0.9 to 2.1 degrees. At the end of the acetic fermentation, dead cells were estimated to 98% at and acetic acid to 4.7 degrees. Using consecutive fermentations is suitable technique for vinegar production from mango juice. The application of the present results may contribute to avoid fruits post harvest losses. PMID:20437702

Ameyapoh, Y; Leveau, Jean-Yves; Karou, Simplice D; Bouix, M; Sossou, Seyram K; De Souza, C

2010-02-01

407

Local heat transfer in internally cooled turbine airfoil leading edge regions. I - Impingement cooling without film coolant extraction. II - Impingement cooling with film coolant extraction  

Microsoft Academic Search

The highly localized internal heat transfer characteristics of large-scale models of impingement-cooled turbine blade leading edge regions presently studied derives its cooling from a single line of equally-spaced multiple jets aimed at the leading-edge apex, and exiting the leading-edge region in the opposite or chordwise direction. Detailed two-dimensional local surface Nusselt number distributions have been obtained with temperature-indicating coatings. Results

R. S. Bunker; D. E. Metzger

1988-01-01

408

Optimization of Pin-Fin Heat Sinks Using Anisotropic Local Thermal Nonequilibrium Porous Model in a Jet Impinging Channel  

Microsoft Academic Search

A numerical study has been carried out to optimize the thermal performance of a pin-fin heat sink. A pin-fin heat sink, which is placed horizontally in a channel, is modeled as a hydraulically and thermally anisotropic porous medium. A uniform heat flux is prescribed at the bottom of the heat sink. Cool air is supplied from the top opening of

Seo Young Kim; Andrey V. Kuznetsov

2003-01-01

409

Heat production in cold and long scotophase acclimated and winter acclimatized rodents  

NASA Astrophysics Data System (ADS)

Heat production by means of oxygen consumptionVo2 (at Ta = 6° C, 25° C, 30° C, and 32° C) and non-shivering thermogenesis (NST) were studied in individuals of a diurnal rodent ( Rhabdomys pumilio) and a nocturnal rodent ( Praomys natalensis). The studied mice were acclimated to cold at Ta=8°C with a photoperiod of LD 12:12. On the otherhand specimens of these two species were acclimated at Ta=25°C with a long scotophase LD8:16