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1

Nanoparticles heat through light localization.  

PubMed

Aqueous solutions containing light-absorbing nanoparticles have recently been shown to produce steam at high efficiencies upon solar illumination, even when the temperature of the bulk fluid volume remains far below its boiling point. Here we show that this phenomenon is due to a collective effect mediated by multiple light scattering from the dispersed nanoparticles. Randomly positioned nanoparticles that both scatter and absorb light are able to concentrate light energy into mesoscale volumes near the illuminated surface of the liquid. The resulting light absorption creates intense localized heating and efficient vaporization of the surrounding liquid. Light trapping-induced localized heating provides the mechanism for low-temperature light-induced steam generation and is consistent with classical heat transfer. PMID:24960442

Hogan, Nathaniel J; Urban, Alexander S; Ayala-Orozco, Ciceron; Pimpinelli, Alberto; Nordlander, Peter; Halas, Naomi J

2014-08-13

2

Local heating realization by reverse thermal cloak  

PubMed Central

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

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

2014-01-01

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 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

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 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

7

Measurement of flow field and local heat transfer distribution on a scraped heat exchanger crystalliser surface  

E-print Network

Measurement of flow field and local heat transfer distribution on a scraped heat exchanger.ravelet@laposte.net Geert-Jan Witkamp G.J.Witkamp@xs4all.nl Abstract In a cylindrical scraped heat exchanger crystallizer geometry the flow field influence on the local heat transfer distribution on an evenly cooled scraped heat

Boyer, Edmond

8

Radiogenic heat production in continental lithosphere”  

NASA Astrophysics Data System (ADS)

About half the heat from continents is derived from the radiogenic decay of trace quantities of the unstable isotopes of uranium, thorium, and potassium in the continental crust. This contribution to surface heat flow is highly variable, however, typically resulting in a large scatter of surface heat flow values even in stable regions. Approximately 20 years ago, careful work by Robert Roy, Ed Decker, and Dave Blackwell with Francis Birch (Earth and Planetary Science Letters, vol. 5, pp. 1-12, 1968) showed that for well determined heat flow values in plutonic rocks, surface heat flow is linearly related to surface heat production in a given province. This relationship allows heat flow to be separated into two components: heat generated in the upper crustal zone enriched in heat-producing isotopes and heat from below this zone (the “reduced” heat flow). Art Lachenbruch quickly showed that the only distribution of heat production with depth that would satisfy this linear relationship under conditions of differential erosion is an exponential decrease with depth (in the Journal of Geophysical Research, vol. 73, pp. 6977-6989, 1968). The relationship has now been extended to include heat flow-heat production data from high-grade metamorphic rocks, and heat flow provinces have been defined in every continent except Antarctica. Two major problems remain, however:

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

Tailoring Material Properties of Aluminum by Local Laser Heat Treatment  

NASA Astrophysics Data System (ADS)

The local laser heat treatment of precipitation hardenable aluminum alloys enables the tailoring of the materials properties and the manufacturing of lightweight and crash-proof components for the body in white. For conventional aluminum sheet metals and profiles the formability is enhanced by an indirect approach. Thereby specific parts of the products are softened in order to improve the material flow towards crack critical areas during the forming operation. For innovative high-strength aluminum sheet metal with nanocrystalline grain structure produced in the Accumulative Roll Bonding process in addition to the indirect approach a direct enhancement of the formability by recrystallization effects is possible.

Merklein, Marion; Böhm, Wolfgang; Lechner, Michael

11

Boiling local heat transfer enhancement in minichannels using nanofluids  

NASA Astrophysics Data System (ADS)

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.

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

2013-03-01

12

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. PMID:23506445

2013-01-01

13

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

14

Characteristic of Local Boiling Heat Transfer of Ammonia / Water Binary Mixture on the Plate Type Evaporator  

NASA Astrophysics Data System (ADS)

Ocean thermal energy conversion (OTEC) and discharged thermal energy conversion (DTEC) are expected to be the next generation energy production systems. Both systems use a plate type evaporator, and ammonia or ammonia/water mixture as a working fluid. It is important to clarify heat transfer characteristic for designing efficient power generation systems. Measurements of local boiling heat transfer coefficients and visualization were performed for ammonia /water mixture (z = 0.9) on a vertical flat plate heat exchanger in a range of mass flux (7.5 - 15 kg/m2s), heat flux (15 - 23 kW/m2), and pressure (0.7 - 0.9 MPa). The result shows that in the case of ammonia /water mixture, the local heat transfer coefficients increase with an increase of vapor quality and mass flux, and decrease with an increase of heat flux, and the influence of the flow pattern on the local heat transfer coefficient is observed.

Okamoto, Akio; Arima, Hirofumi; Kim, Jeong-Hun; Akiyama, Hirokuni; Ikegami, Yasuyuki; Monde, Masanori

15

Cascade heat recovery with coproduct gas production  

DOEpatents

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

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

1986-01-01

16

Cascade heat recovery with coproduct gas production  

DOEpatents

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

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

1986-10-14

17

High-power ELF radiation generated by modulated HF heating of the ionosphere can cause Earthquakes, Cyclones and localized heating  

E-print Network

, Cyclones and localized heating Fran De Aquino Maranhao State University, Physics Department, S, Cyclones and strong localized heating. . Key words: Physics of the ionosphere, radiation processes Earthquakes, Cyclones and strong localized heating. 2. Gravitational Shielding The contemporary greatest

Paris-Sud XI, Université de

18

Measurement of local high-level, transient surface heat flux  

SciTech Connect

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, C.H.

1988-09-01

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

Local, instantaneous heat transfer in pulse-stabilized fluidization  

SciTech Connect

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

Pence, D.V. [Univ. of Rhode Island, Kingston, RI (United States). Dept. of Mechanical Engineering and Applied Mechanics; Beasley, D.E. [Clemson Univ., SC (United States). Dept. of Mechanical Engineering

1996-12-31

21

Local Laser Heat Treatment in Dual-Phase Steels  

NASA Astrophysics Data System (ADS)

This research deals with processes leading to local strengthening effects in hot-rolled dual-phase (DP) steels. For this purpose, a method was investigated to achieve local strengthening, namely, local laser heat treatment (LHT). DP sheet steels were globally and homogenously deformed with different degrees of prestrains by cold rolling and subsequently locally heat treated by laser. Following this treatment with selected parameters, the microstructure of the surface and cross section of the heat-treated area as well as the mechanical properties were evaluated by light optical microscopy (LOM), scanning electron microscopy (SEM), as well as transmission electron microscopy (TEM), hardness measurement, and tensile testing. It can be stated that with partial heat treatment, local high strengthening can be produced. At lower heat treating temperatures, this effect could be attributed to bake hardening (BH). Increasing the prestrain as well as temperature results in improving the local properties. With increased heat treating temperature, the initial microstructure near the surface is affected. Partial strengthening of DP steels by laser can open up new fields of application for locally using the strengthening effect to only influence relevant areas of interest, thus providing the potential for saving energy and designed the component's behavior.

Asadi, Mehdi; Frommeyer, Georg; Aghajani, Ali; Timokhina, Ilana; Palkowski, Heinz

2012-04-01

22

Local heat transfer measurements of plate finned-tube heat exchangers by infrared thermography  

Microsoft Academic Search

An experimental study is performed using an infrared thermovision to monitor temperature distribution over a plate-fin surface inside the plate finned-tube heat exchangers. The differentiation of the temperature function is derived to determine the local convective heat transfer coefficients on the tested fin, using a local element lumped conduction equation included the convective effect on the boundaries with experimental data.

Herchang Ay; JiinYuh Jang; Jer-Nan Yeh

2002-01-01

23

Local heating-induced plastic deformation in resistive switching devices  

NASA Astrophysics Data System (ADS)

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

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

2011-09-01

24

On the local thermal equilibrium in microchannel heat sinks  

Microsoft Academic Search

In this paper, analytical solutions for temperature distributions in the microchannel heat sink are obtained by using both one-equation and two-equation models for heat transfer. From the analytical solutions, variables of engineering importance are identified as the Darcy number and the effective thermal conductivity ratio, and their effects are studied. To check the validity of the local thermal equilibrium assumption

S. J. Kim; D. Kim; D. Y. Lee

2000-01-01

25

Local cloning of two product states  

SciTech Connect

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 [State Key Laboratory of Intelligent Technology and Systems, Department of Computer Science and Technology, Tsinghua University, Beijing 100084 (China)

2005-09-15

26

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

NASA Astrophysics Data System (ADS)

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

Bull, Geoffrey R.

27

Thermal response of a flat heat pipe sandwich structure to a localized heat flux  

Microsoft Academic Search

The temperature distribution across a flat heat pipe sandwich structure, subjected to an intense localized thermal flux has been investigated both experimentally and computationally. The aluminum sandwich structure consisted of a pair of aluminum alloy face sheets, a truncated square honeycomb (cruciform) core, a nickel metal foam wick and distilled water as the working fluid. Heat was applied via a

G. Carbajal; C. B. Sobhan; G. P. Peterson; D. T. Queheillalt; H. N. G. Wadley

2006-01-01

28

A Local Heat Flux Measurement Technique for Inclined Heat Exchanger Tubes  

Microsoft Academic Search

This article presents the design, fabrication, and calibration of thermocouple pairs for local heat flux measurement. The intended application of the thermocouple pairs is on the tubes of phase-change heat exchangers experiencing heat fluxes on the order of 10 W\\/m. Particular advantages of this technique are that it is accurate even for thin-wall tubes, there are no restrictions on the

T. Wu; K. Vierow

2006-01-01

29

Local Modification of Cu Microwires by Joule Heating  

NASA Astrophysics Data System (ADS)

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

Tohmyoh, Hironori; Ishihara, Mitsuharu

2013-07-01

30

Creation of skyrmions and antiskyrmions by local heating.  

PubMed

Heating a system usually increases entropy and destroys order. However, there are also cases where heating gives a system the energy to overcome the potential barrier to reach a state with a nontrivial ordered pattern. Whether heating can manipulate the topological nature of the system is especially important. Here, we theoretically show by microsimulation that local heating can create topological magnetic textures, skyrmions, in a ferromagnetic background of chiral magnets and dipolar magnets. The resulting states depend sharply on intensity and spot size of heating, as well as the interaction to stabilize the skyrmions. Typically, the creation process is completed within 0.1?ns and 10?nm at the shortest time and smallest size, and these values can be longer and larger according to the choice of system. This finding will lead to the creation of skyrmions at will, which constitutes an important step towards their application to memory devices. PMID:25322803

Koshibae, Wataru; Nagaosa, Naoto

2014-01-01

31

Relaxation of geothermal-reservoir stresses induced by heat production  

NASA Astrophysics Data System (ADS)

Fifteen million kWh of thermal energy were produced during 281 days of operation of the hot dry rock (HDR) geothermal reservoir at Fenton Hill, New Mexico. Following this heat production the thermal stresses and strains so were partially released by a shot, 7-h pressurization of the reservoir above the local tectonic confining stress. Following the partial stress release, it was found that the resistance to water flow through the reservoir was decreased by 37 percent, and that the reservoir volume, as measured by tracer studies, increased by 43 percent. Microseismic events recorded with geophones in two deep wells at positions within a few hundred meters of the reservoir were concentrated in those regions of the reservoir most affected by thermal depletion. These events define a reservoir region and size in qualitative agreement with estimates based upon heat production modeling.

Murphy, H.; Aamodt, R.; Fisher, H.; Grant, T.; Grigsby, C.; Hendron, R.; Keppler, H.; Pearson, C.; Potter, R.; Suhr, G.

1981-08-01

32

Viscoplastic response of structures for intense local heating  

NASA Technical Reports Server (NTRS)

A thermoviscoplastic finite element method employing the Bodner-Partom constitutive model is used to investigate the response of simplified thermal-structural models to intense local heating. With rapid rises of temperature, the nickel alloy structures display initially higher yield stresses due to strain rate effects. As temperatures approach elevated values, yield stress and stiffness degrade rapidly and pronounced plastic deformation occurs.

Thornton, Earl A.; Kolenski, J. D.

1991-01-01

33

Interface oscillation of subcooled flow boiling in locally heated microchannels  

NASA Astrophysics Data System (ADS)

An investigation was conducted to understand flow boiling of subcooled de-ionized water in locally heated parallel microchannels. High-speed visualization technology was employed to visually observe the transient phase change process in an individual microchannel. Signal analysis method was employed in studying the interface movement and phase change process. The phase change at locally heated condition was different from those at entirely heated condition where elongated bubble(s) stayed quasi-stable for a long time without venting out. Diversified and intensive interface oscillation was observed occurring on both of the upstream and downstream bubble caps. Evaporation and condensation modes were characterized with distinguished oscillation frequencies. The film-driven oscillations of both evaporating and condensing interfaces generally operated at higher frequencies than the oscillations driven by nucleation or dropwise condensation.

Liu, J. T.; Peng, X. F.

2009-02-01

34

Local cloning of two product states  

E-print Network

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. In this paper, we show that cloning is not that lucky; namely, conclusive LOCC cloning of two product states is strictly less efficient than global cloning.

Zhengfeng Ji; Yuan Feng; Mingsheng Ying

2005-03-23

35

Technologies for production of Electricity and Heat in Sweden  

E-print Network

Technologies for production of Electricity and Heat in Sweden Wind Energy ­ in perspective Morthorst December 2008 #12;Technologies for production of Electricity and Heat in Sweden Wind Energy Erik Morthorst Title: Technologies for production of Electricity and Heat in Sweden Wind Energy

36

Characterization of local heat fluxes around ICRF antennas on JET  

SciTech Connect

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

Campergue, A.-L. [Ecole Nationale des Ponts et Chaussées, F77455 Marne-la-Vallée (France); Jacquet, P.; Monakhov, I.; Arnoux, G.; Brix, M.; Sirinelli, A. [Euratom/CCFE Association, Culham Science Centre, Abingdon, OX14 3DB (United Kingdom); Bobkov, V. [Max-Planck-Institut für Plasmaphysik, EURATOM-Assoziation, Garching (Germany); Milanesio, D. [Politecnico di Torino, Department of Electronics, Torino (Italy); Colas, L. [CEA, IRFM, F-13108 Saint-Paul-Lez-Durance (France); Collaboration: JET-EFDA Contributors

2014-02-12

37

Local and Nonlocal Parallel Heat Transport in General Magnetic Fields  

SciTech Connect

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

Castillo-Negrete, D. del; Chacon, L. [Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-8071 (United States)

2011-05-13

38

Local and nonlocal parallel heat transport in general magnetic fields  

SciTech Connect

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

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

2011-01-01

39

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

40

Nickel foil microcantilevers for magnetic manipulation and localized heating  

PubMed Central

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

Gaitas, Angelo; McNaughton, Brandon H.

2014-01-01

41

Localized heating during serrated plastic flow in bulk metallic glasses  

Microsoft Academic Search

We have studied the serrated plastic flow observed in Zr40Ti14Ni10Cu12Be24 and Pd40Ni40P20 bulk metallic glass alloys tested in uniaxial compression. Quantitative measurements with sufficient temporal resolution to record the fine-scale structure of the data are reported. These data are used to predict temperature increases in single shear bands due to local adiabatic heating caused by the work done on the

Wendelin J Wright; Ricardo B Schwarz; William D Nix

2001-01-01

42

Local and nonlocal parallel heat transport in general magnetic fields  

NASA Astrophysics Data System (ADS)

A novel approach that enables the study of purely parallel transport in magnetized plasmas is proposed. The approach is based on a Lagrangian Green's function method applicable to general magnetic fields (2-D and 3-D from integrable to completely chaotic), and with local or nonlocal parallel heat-flux closures. The approach is free from numerical pollution, and preserves temperature positivity by construction. The method is used to study: (i) local and nonlocal temperature flattening in magnetic islands; (ii) the fractal structure of the devil staircase temperature profile in weakly chaotic fields; and (iii) effective radial transport in fully chaotic 3D fields. For (iii), self-similar evolution of the form T=(?t)^-?/2 f(?) is observed with similarity variable ?=(?-)/(?t^?/2) where ? is a radial flux function. Different to the well-know local transport case (Rechester-Rosenbluth), it is shown that in the case of non-local parallel transport f is an algebraic decaying, f ˜&-3circ;, non-Gaussian function, and ?=1. Recent work on the extension of the method to include perpendicular transport and heat sources is presented. The approach is algorithmically scalable, and second-order accurate in time on the slow-perpendicular-time scale. Numerical examples of relevance to magnetic fusion geometries will be presented.

Del-Castillo-Negrete, Diego; Chacon, Luis

2010-11-01

43

Localized, plasmon-mediated heating from embedded nanoparticles in nanocomposites  

NASA Astrophysics Data System (ADS)

Metallic nanoparticles exhibit a surface plasmon resonance which, when excited with visible light, results in a dramatic increase in the nanoparticle temperature. Previously such localized heating has been primarily employed in biomedical research and other experiments involving aqueous environments. In this work, we investigated use of the nanoparticles in solid phase to re-shape, bond, melt, and otherwise process nanofibrous mats of ˜200 nm diameter nanofibers doped with ˜80 nm spherical gold nanoparticles. Under low light intensities (100 mW/cm^2 @ 532 nm) and dilute nanoparticle loading (˜0.15% volume fraction), irradiation of a few minutes melted nanofibrous mats of poly (ethylene oxide) (Tm = 65 degree C). Control samples without gold nanoparticles displayed no melting. Because the heat is generated from within the material and only at the nanoparticle locations, this technique enables true nanoprocessing -- the non-contact, controlled application of heat at specific nano-sized locations within a material to effect desired local changes. Funded by CMMI-0829379.

Maity, Somsubhra; Downen, Lori; Bochinski, Jason; Clarke, Laura

2010-03-01

44

Fuel cell entropy production with ohmic heating and diffusive polarization  

E-print Network

Fuel cell entropy production with ohmic heating and diffusive polarization G.F. Naterer a,*, C production of ohmic heating and concentration polarization is investigated for two types of fuel cells (PEMFC oxide fuel cell (SOFC), this article formulates entropy production within electrodes of a proton

Naterer, Greg F.

45

The erosion of a salinity step by a localized heat source  

E-print Network

The erosion of a salinity step by a localized heat source D.M. Leppinen and S.B. Dalziel Department compare the erosion a salinity step by a localized heat source with the erosion of the same salinity step layers and it is shown that a localized heat source is more e cient at eroding a salinity step than

Dalziel, Stuart

46

Thermoviscoplastic response of thin plates subjected to intense local heating  

NASA Technical Reports Server (NTRS)

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

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

1992-01-01

47

Viscoplastic response of structures for intense local heating  

NASA Technical Reports Server (NTRS)

A thermoviscoplastic finite element method employing the Bodner-Partom constitutve model is used to investigate the response of simplified thermal-structural models to intense local heating. The computational method formulates the problem in rate and advances the solution in time by numerical integration. The thermoviscoplastic response of simplified structures with prescribed temperatures is investigated. With rapid rises of temperature, the nickel alloy structures display initially higher yield stresses due to strain rate effects. As temperatures approach elevated values, yield stress and stiffness degrade rapidly and pronounced plastic deformation occurs.

Thornton, Earl A.; Kolenski, J. D.

1994-01-01

48

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

49

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

50

Technologies for Production of Heat and Electricity  

SciTech Connect

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

Jacob J. Jacobson; Kara G. Cafferty

2014-04-01

51

Future crop production threatened by extreme heat  

NASA Astrophysics Data System (ADS)

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

Siebert, Stefan; Ewert, Frank

2014-04-01

52

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

Microsoft Academic Search

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

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

2011-01-01

53

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

54

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. PMID:23549139

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

2013-01-01

55

Local thermodynamic equilibrium in rapidly heated high energy density plasmas  

SciTech Connect

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. [York Plasma Institute, Department of Physics, University of York, Heslington, York YO10 5DD (United Kingdom)

2014-06-15

56

Heat flow, crustal heat production, and crustal evolution in the Canadian Shield  

NASA Astrophysics Data System (ADS)

More than 200 heat flow values are available for the entire Canadian Shield, in provinces that range in age between >3Ga and <1Ga. Heat production has been determined at nearly all the heat flow sites. In addition, systematic heat production studies have been conducted that sample through the most important lithologies and all structural levels. At the largest scale, we find that the mean heat flow is the same 41mW~m-2 in all provinces regardless of age, with the exception of the Archean Slave Province where the limited data set suggests that surface heat flow is higher (50mW~m-2). The Slave Province is also characterized by high surface heat production. On the other hand, geothermobarometry on mantle xenoliths indicate lower mantle temperature in the Slave than in the Superior Province. Heat flow and xenolith data can be reconciled if variations in heat flow are accounted for by crustal heat production. Variations are found at the smaller scale of individual subprovinces with different lithologies. The southern part of the Superior Province consists of E-W trending belts with ages decreasing southwards. This age trend seems to be reflected in a progressive southward increase in heat flow in the greenstone belts. Within a single belt, variations in heat flow reflect changes in the average crustal composition, essentially the proportion of mafic to felsic rocks. In the PaleoProterozoic (1.8Ga) Trans Hudson Orogen, juvenile crust is less radiogenic and has lower heat flow (37 mW~m-2) than the reworked Archean crust of the Thompson Belt (53mW~m-2). Several examples of high amplitude-short wavelength variations in heat flow have been found suggesting that these variations are due to crustal sources. Different methods have been used to estimate the crustal and mantle contribution in different regions of the Shield. The range of mantle heat flow values is very narrow 11-15mW~m-2 and within the error limits of the estimate (± 2 mW~m-2), implying that most of the heat flow variations are accounted by crustal heat production. With such narrow range of Moho heat flow variations, we can define a differentiation index, as the ratio of the surface to the mean crustal heat production. This index is positively correlated with the surface heat flow at the time of crustal stabilization, which is consistent with high temperature in the lower crust resulting in a very differentiated crust. Consequently, temperature differences are small at the base of the crust and in the lithospheric mantle.

Mareschal, J.; Jaupart, C.

2007-12-01

57

Measured Local Heat Transport in Turbulent Rayleigh-Benard Convection X.-D. Shang,1  

E-print Network

September 2002; published 20 February 2003) Local convective heat flux in turbulent thermal convection filled with water. It is found that fluctuations of the vertical heat flux are highly intermittent heat is trans- ported vertically through a convection cell [1­3]. A large number of global heat

Tong, Penger

58

Heat production by single fibres of frog muscle.  

PubMed

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

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

1983-04-01

59

Natural convection in enclosures with localized heating from below and symmetrical cooling from sides  

Microsoft Academic Search

Natural convection of air in a two-dimensional, rectangular enclosure with localized heating from below and symmetrical cooling from the sides has been numerically investigated. Localized heating is simulated by a centrally located heat source on the bottom wall, and four different values of the dimensionless heat source length, 1\\/5, 2\\/5, 3\\/5 and 4\\/5 are considered. Solutions are obtained for Rayleigh

Orhan Aydin; Wen-Jei Yang

2000-01-01

60

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

61

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

62

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...

63

Rubisco activase and wheat productivity under heat stress conditions  

Technology Transfer Automated Retrieval System (TEKTRAN)

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

64

Oil production response to in situ electrical resistance heating  

E-print Network

OIL PRODUCTION RESPONSE TO I? SITU ELECTRICAL RESISTANCE HEATING A Thesis by FRED WILLIAM MCDOUGAL Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE May... 1987 Major Subject: Petroleum Engineering OIL PRODUCTION RESPONSE TO IN SITV ELECTRICAL RESISTANCE HEATING A Thesis by FRED WILLIAM MCDOUGAL Approved to style and content by: R. A. Wattenbar (Chair of Commi ee) L. D. Piper (Member) D. D. Van...

McDougal, Fred William

1987-01-01

65

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

66

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

Federal Register 2010, 2011, 2012, 2013

...Circuit Packages Provided With Multiple Heat- Conducting Paths and Products Containing...circuit packages provided with multiple heat-conducting paths and products containing...circuit packages provided with multiple heat-conducting paths and products...

2012-07-05

67

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

Federal Register 2010, 2011, 2012, 2013

...Circuit Packages Provided With Multiple Heat- Conducting Paths and Products Containing...Circuit Packages Provided With Multiple Heat-Conducting Paths and Products Containing...circuit packages provided with multiple heat-conducting paths and products...

2012-06-06

68

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

69

Local heat transfer and thermal performance on periodically dimple-protrusion patterned walls for compact heat exchangers  

Microsoft Academic Search

In this study, heat transfer and thermal performance of a periodically dimple-protrusion patterned surface have been investigated to enhance energy-efficiency in compact heat exchangers. The local heat transfer coefficients on the dimple\\/protrusion walls are derived using a transient TLC (Thermochromic Liquid Crystal) technique. The periodically patterned surface is applied to the bottom wall only or both the bottom and top

Sang Dong Hwang; Hyun Goo Kwon; Hyung Hee Cho

2010-01-01

70

Microwave Heating System Using Lens Applicator for Localized Hyperthermia  

Microsoft Academic Search

A computer controlled microwave heating system for hyperthermia was developed with direct contact lens applicator to deposit the energy of electromagnetic field deep in human tissues. The results show that with the applicator operate at 2450 MHz, over double of heating depth was realized compared with simple waveguide applicators. And the heating result using the developed system show that the

Yoshio NIKAWA; Yasushi TAKAHASHI; Hiromi WATANABE; Makoto KIKUCHI; S. Mori

1985-01-01

71

Quantification of Local Ozone Production Attributable to Automobile Hydrocarbon Emissions  

Microsoft Academic Search

When automobile hydrocarbons are exhausted into the atmosphere in the presence of NOx and sunlight, ground- level ozone is formed. While researchers have used Maximum Incremental Reactivity (MIR) factors to estimate ozone production, this procedure often overestimates Local Ozone Production (LOP) because it does not consider local atmospheric conditions. In this paper, an enhanced MIR methodology for estimating actual LOP

Stanislav V. Bohac; Dennis N. Assanis

72

THE IMPACT OF HURRICANE STRIKES ON LOCAL CROPLAND PRODUCTIVITY  

E-print Network

THE IMPACT OF HURRICANE STRIKES ON LOCAL CROPLAND PRODUCTIVITY: EVIDENCE FROM THE CARIBBEAN Eric://www.enseignement.polytechnique.fr/economie/ mailto:chantal.poujouly@polytechnique.edu hal-00393883,version1-10Jun2009 #12;THE IMPACT OF HURRICANE° 2009-14 Abstract: We empirically estimate the impact of hurricane strikes on local crop productivity

Paris-Sud XI, Université de

73

LOCAL LIMIT THEOREM FOR NONUNIFORMLY PARTIALLY HYPERBOLIC SKEW-PRODUCTS  

E-print Network

LOCAL LIMIT THEOREM FOR NONUNIFORMLY PARTIALLY HYPERBOLIC SKEW-PRODUCTS AND FAREY SEQUENCES S both the central limit and local limit theorems. These results apply to a random walk related . . . . . . . . . . . . . . . . . . . . . . . . . . . . 212 4. Strategy and tools for the local limit theorem . . . . . . . . . . . . . . . 225 5. Proof

Gouëzel, Sébastien

74

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

PubMed Central

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

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

2012-01-01

75

PUBLISHED VERSION Characterization of local heat fluxes around ICRF antennas on JET  

E-print Network

PUBLISHED VERSION Characterization of local heat fluxes around ICRF antennas on JET A.-L. Campergue at : http://dx.doi.org/10.1063/1.4864538 #12;Characterization of local heat fluxes around ICRF antennas Antennas on JET AL. Camperguea , P. Jacquetb , V. Bobkovc , D. Milanesiod , I. Monakhovb , L. Colase , G

76

Evaluation of odor characteristics of heat-dried biosolids product.  

PubMed

Because it produces an exceptional quality pellet product, heat drying of wastewater solids from municipal wastewater treatment plants is becoming more prevalent as biosolids management regulations become more restrictive. The product from heat drying is sometimes odorous as dry or wetted pellets. The odors, although not regulated, can be important for marketability and public acceptance of the product. The reasons for the odors are usually a result of upstream processing and management of wastewater solids prior to drying. The goals of this study were to determine odor characteristics and to compare the odors produced by evaluating odors from four types of heat-dried biosolids products: all undigested; primary digested-waste activated sludge (WAS) undigested; all digested; and WAS lime stabilized pellets. The results are described in this paper. PMID:14704011

Murthy, Sudhir; Kim, Hyunook; Peot, Christopher; McConnell, Laura; Strawn, Mary; Sadick, Thomas; Dolak, Ivan

2003-01-01

77

Distribution of local heat transfer coefficient values in the wall region of an agitated vessel  

Microsoft Academic Search

Experimentally found local heat transfer coefficients are analyzed as a function of the measuring point on the heat transfer\\u000a surface area of the agitated vessel wall and of the impeller eccentricity. Eccentric Rushton turbine and A 315 impeller are\\u000a considered. Local heat transfer coefficients were measured by means of the computer-aided electrochemical method. The measurements\\u000a were performed in an agitated

Magdalena Cudak; Joanna Karcz

2008-01-01

78

Investigation of local heat transfer in compact heat exchangers by holographic interferometry  

Microsoft Academic Search

Compact heat exchangers are key components for the development of future aircraft devices. An enhancement of the heat transfer results in a decrease in the heat exchanger size and thus in lower weight and lower investment costs. Exact knowledge of the temperature distribution in the boundary layer is necessary for a specific augmentation of heat transfer. Holographic interferometry was applied

R. Fehle; J. Klas; F. Mayinger

1995-01-01

79

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

80

Localized induction heating solder bonding for wafer level MEMS packaging  

Microsoft Academic Search

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

Hsueh-An Yang; Mingching Wu; Weileun Fang

2005-01-01

81

Glove thermal insulation: local heat transfer measures and relevance  

Microsoft Academic Search

When exposed to cold, the hands need to be protected against heat loss not only in order to reduce thermal discomfort, but also to keep their efficiency. Although gloves are usually the most common protection, their thermal insulation is generally unknown. The aim of this study was to measure the heat losses from a gloved hand with a special interest

Hayet Sari; Maurice Gartner; Alain Hoeft; Victor Candas

2004-01-01

82

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

83

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

NASA Technical Reports Server (NTRS)

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

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

2002-01-01

84

Local aerodynamics and heat transfer in beds of packed spheres, simulating spherical fuel elements  

Microsoft Academic Search

An experimental study of the three-dimensional distribution of pressure coefficients and the coefficients of local heat transfer in beds of staggered spheres proved that the local characteristics depend strongly on the value of design factor kappa and on the location of the sphere within the packed bed. It was proved that largest changes in the local characteristics occur in regions

G. V. Zadanavicius; L. A. Margis

1983-01-01

85

Natural convection in an enclosure with localized heating from below  

SciTech Connect

Natural convection heat transfer in a cylindrical enclosure, heated partially from below by a disk shaped heating surface and cooled from the top and the side, was investigated experimentally and numerically. Heat transfer measurements are presented for Rayleigh numbers ranging from 10{sup 8} to 2 {times} 10{sup 10} with water as the test fluid. The test results were correlated by an equation of the form Nu{sub D} = 0.16 Ra{sub D}{sup 1/3} for a Prandtl number of 2 and aspect ratio of 1.01. The flow field was numerically analyzed using FLUENT code. The {kappa}-{epsilon} model for predicting the turbulent flows with buoyancy was used.

Ulucakli, M.E. [Lafayette Coll., Easton, PA (United States). Dept. of Mechanical Engineering

1996-12-31

86

Indication of anomalous heat energy production in a reactor device  

E-print Network

An experimental investigation of possible anomalous heat production in a special type of reactor tube named E-Cat HT is carried out. The reactor tube is charged with a small amount of hydrogen loaded nickel powder plus some additives. The reaction is primarily initiated by heat from resistor coils inside the reactor tube. Measurement of the produced heat was performed with high-resolution thermal imaging cameras, recording data every second from the hot reactor tube. The measurements of electrical power input were performed with a large bandwidth three-phase power analyzer. Data were collected in two experimental runs lasting 96 and 116 hours, respectively. An anomalous heat production was indicated in both experiments. The 116-hour experiment also included a calibration of the experimental set-up without the active charge present in the E-Cat HT. In this case, no extra heat was generated beyond the expected heat from the electric input. Computed volumetric and gravimetric energy densities were found to be far above those of any known chemical source. Even by the most conservative assumptions as to the errors in the measurements, the result is still one order of magnitude greater than conventional energy sources.

Giuseppe Levi; Evelyn Foschi; Torbjörn Hartman; Bo Höistad; Roland Pettersson; Lars Tegnér; Hanno Essén

2013-05-16

87

Crossed products of locally C*-algebras and Morita equivalence  

E-print Network

We introduce the notion of strong Morita equivalence for group actions on locally C*-algebras and prove that the crossed products associated with two strongly Morita equivalent continuous inverse limit actions of a locally compact group G on the locally C*-algebras A and B are strongly Morita equivalent. This generalizes a result of F. Combes, Proc. London Math. Soc. 49(1984) and R. E. Curto, P.S. Muhly, D. P. Williams, Proc. Amer. Soc. 90(1984).

Joita, Maria

2007-01-01

88

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

2015-01-01

89

Conservation of Heat Energy at Hot Petroleum Products Terminals  

E-print Network

Exxon operates several terminals which store asphalt and heavy fuel oil. Due to the rising cost of fuels, Exxon initiated a study to identify economic investments which would reduce the fuel needed to heat these products. First, fuel usage at four...

Powell, J. C.; Graham, R. M.

1981-01-01

90

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

91

Local heat transfer distribution in a triangular channel with smooth walls and staggered ejection holes  

E-print Network

Transient liquid crystal experiments have been conducted to determine the distribution of the local heat transfer coefficient in a triangular channel with smooth wails and ejection holes along one or two of the wails. The end of the test channel...

Moon, Sung-Won

1999-01-01

92

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

NASA Technical Reports Server (NTRS)

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

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

1982-01-01

93

Local\\/global analysis applications to ground-coupled heat transfer  

Microsoft Academic Search

In this paper, a new local\\/global analysis technique is developed to solve multi-dimensional ground-coupled heat transfer problems. In particular, the novel method is applied in this paper to determine foundation heat transfer for buildings with slab-on-grade floors. It is found that analytical solutions can be used successfully to capture thermal bridging effect when integrated in the developed local\\/global analysis technique.

Adnan Al-Anzi; Moncef Krarti

2003-01-01

94

Local\\/global analysis of transient heat transfer from building foundations  

Microsoft Academic Search

In this paper, a novel local\\/global (L–G) analysis technique is developed to solve transient ground-coupled heat transfer problems. The presented (L–G) analysis approach combines analytical and numerical techniques to obtain solutions of building foundation heat transfer problems with significant localized thermal bridges. Even though simplified analytical solutions generally fail to account for thermal bridging in building foundations, they can be

Adnan Al-Anzi; Moncef Krarti

2004-01-01

95

On the Reaction Product and Heat Correlation for LENRs  

E-print Network

“Low Energy Nuclear Reactions”, or LENRs, typically involve electrolytes containing light water along with electrodes made of metals such as Ni, Ti and Pd. In these experiments a variety of reaction products (isotopes), with masses both higher and lower than that of the host electrode material, have been observed at the University of Illinois (U of IL). Related results, often termed “transmutation ” studies, have been reported by other researchers. These observations suggest that proton-metal initiated reactions occur in such LENR cells. This paper discusses evidence that the production of these reaction products is correlated with the excess heat also frequently observed in LENR cells. Such a correlation for LENR reactions would be equivalent, in principle, to the correlation of He-4 with excess heat that is reported for heavy water-Pd experiments where a D-D reaction is postulated.

George H. Miley

1996-01-01

96

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

97

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

PubMed

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

Gallego-Gómez, Francisco; Blanco, Alvaro; López, Cefe

2012-12-01

98

Enhancement of Localized Heating by Ultrasonically Induced Cavitation in High Intensity Focused Ultrasound Treatment  

Microsoft Academic Search

There are reports that ultrasonically induced cavitation bubbles locally enhance tissue heating in high intensity focused ultrasound (HIFU) treatment. In this study, a high-intensity burst (named ``a triggering pulse'') above the cavitation threshold was used to trigger cavitation. Immediately after that, CW ultrasound (named ``heating waves''), at an intensity level and duration typical for conventional HIFU ablation was irradiated. Before

Ryo Takagi; Shin Yoshizawa; Shin-ichiro Umemura

2010-01-01

99

Local convective heat transfer from a horizontal tube in an acoustic cavitation field  

Microsoft Academic Search

An experiment has been carried out to investigate the local convective heat transfer from a horizontal circular copper tube\\u000a in an acoustic cavitation field. The effects of acoustical parameters (including sound source intensity, the vibrator location\\u000a and sound distance), fluid temperature and thermophysical properties of working fluid on heat transfer enhancement were studied,\\u000a as well as the variation of heat

Dingwei Zhou; Xuegong Hu; Dengying Liu

2004-01-01

100

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

101

Evidence for localized cell heating induced by infrared optical tweezers.  

PubMed

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

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

1995-05-01

102

Quality assessment of palm products upon prolonged heat treatment.  

PubMed

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

Tarmizi, Azmil Haizam Ahmad; Lin, Siew Wai

2008-01-01

103

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

Technology Transfer Automated Retrieval System (TEKTRAN)

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

104

Local and National Government-set rules for Production of Agricultural Products  

E-print Network

in the market #12;Production standards and trade barriers · Unless there are import barriers, cost · National, state, and local measures need trade barriers to change animal care standards, unless local production standards are required of imports · This is a natural case for a technical barriers dispute

Schladow, S. Geoffrey

105

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

106

Localized corrosion of aluminum alloys for OTEC heat exchangers  

SciTech Connect

The effects of dissolved oxygen, pH and temperature on the rate of initiation and growth of pitting and crevice corrosion of aluminum alloy 5052 and pure aluminum have been determined. Variations in pH and temperature rather than dissolved oxygen are shown to account for increased corrosion rates of 5000 series aluminum alloys that have been reported for deep ocean exposures. The impact of these results on the use of aluminum for heat exchanger tubing and on possible approaches to corrosion control are discussed. 31 refs.

Dexter, S.C.

1981-01-01

107

Application of heat treatment simulation in production environment  

SciTech Connect

Traditionally experimentation was the only tool for development of heat treatment processes. This approach is not only expensive and time consuming, but also contrary to today`s market needs to reduce lead times and to {open_quotes}Do It Right The First Time{close_quotes} by mastering the process, and planning the production a priori. Consequently, to meet the market challenge, a reliable, economical and quick simulation tool is required, as an alternative to the expensive and time consuming experimentation. This paper deals with the development of a simulation tool capable of predicting hardness, microstructure, residual stresses, and distortions. Good correlation is found between finite element based predictions and experimental results. This predictive tool has been used to solve production problems related to material selection, evaluation of residual stresses, and distortions in heat treated parts.

Clements, T.E.; Chuzhoy, L. [Caterpillar Inc., Peoria, IL (United States); Shareef, I. [Bradley Univ., Peoria, IL (United States)

1996-12-31

108

Grate-firing of biomass for heat and power production  

Microsoft Academic Search

As a renewable and environmentally friendly energy source, biomass (i.e., any organic non-fossil fuel) and its utilization are gaining an increasingly important role worldwide. Grate-firing is one of the main competing technologies in biomass combustion for heat and power production, because it can fire a wide range of fuels of varying moisture content, and requires less fuel preparation and handling.

Chungen Yin; Lasse A. Rosendahl; Søren K. Kær

2008-01-01

109

Monodisperse magnetofluorescent nanoplatforms for local heating and temperature sensing.  

PubMed

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

Zhang, H; Huang, H; He, S; Zeng, H; Pralle, A

2014-11-21

110

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

NASA Astrophysics Data System (ADS)

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

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

1996-11-01

111

Zak transform for semidirect product of locally compact groups  

NASA Astrophysics Data System (ADS)

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

Arefijamaal, Ali Akbar; Ghaani Farashahi, Arash

2013-09-01

112

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

113

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

114

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

Federal Register 2010, 2011, 2012, 2013

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

2012-12-12

115

Cold End Inserts for Process Gas Waste Heat Boilers Air Products, operates hydrogen production plants, which utilize large waste heat boilers (WHB)  

E-print Network

production plants, which utilize large waste heat boilers (WHB) to cool process syngas. The gas entersCold End Inserts for Process Gas Waste Heat Boilers Overview Air Products, operates hydrogen walls. Air Products tasked our team to design an insert to place in the tubes of the WHB to increase

Demirel, Melik C.

116

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

SciTech Connect

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

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

1998-07-01

117

Local production systems in Brazil: mapping, typology and policy suggestions  

Microsoft Academic Search

This paper sets out to advance further in the development of a methodology for mapping, classifying and characterizing Local Production Systems (LPS) in Brazil. Such effort is justified not only for the importance these systems have been amassing for generating jobs and social welfare, economic growth, exports and technological development, but also for the attention they have received from several

Wilson Suzigan; João Furtado; Renato Garcia; Sergio Sampaio

2004-01-01

118

Local kinetic interpretation of entropy production through reversed diffusion  

NASA Astrophysics Data System (ADS)

The time reversal of stochastic diffusion processes is revisited with emphasis on the physical meaning of the time-reversed drift and the noise prescription in the case of multiplicative noise. The local kinematics and mechanics of free diffusion are linked to the hydrodynamic description. These properties also provide an interpretation of the Pope-Ching formula for the steady-state probability density function along with a geometric interpretation of the fluctuation-dissipation relation. Finally, the statistics of the local entropy production rate of diffusion are discussed in the light of local diffusion properties, and a stochastic differential equation for entropy production is obtained using the Girsanov theorem for reversed diffusion. The results are illustrated for the Ornstein-Uhlenbeck process.

Porporato, A.; Kramer, P. R.; Cassiani, M.; Daly, E.; Mattingly, J.

2011-10-01

119

Local kinetic interpretation of entropy production through reversed diffusion.  

PubMed

The time reversal of stochastic diffusion processes is revisited with emphasis on the physical meaning of the time-reversed drift and the noise prescription in the case of multiplicative noise. The local kinematics and mechanics of free diffusion are linked to the hydrodynamic description. These properties also provide an interpretation of the Pope-Ching formula for the steady-state probability density function along with a geometric interpretation of the fluctuation-dissipation relation. Finally, the statistics of the local entropy production rate of diffusion are discussed in the light of local diffusion properties, and a stochastic differential equation for entropy production is obtained using the Girsanov theorem for reversed diffusion. The results are illustrated for the Ornstein-Uhlenbeck process. PMID:22181122

Porporato, A; Kramer, P R; Cassiani, M; Daly, E; Mattingly, J

2011-10-01

120

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

PubMed

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

Li, Xiantao

2014-09-01

121

Effects of heat on workers' health and productivity in Taiwan  

PubMed Central

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

Lin, Ro-Ting; Chan, Chang-Chuan

2009-01-01

122

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

123

Local heat transfer augmentation in channels with two opposite ribbed surfaces  

NASA Technical Reports Server (NTRS)

The local heat transfer coefficient distribution of a square channel with two opposite ribbed walls was determined. The square channel was connected to a sudden contraction entrance in order to simulate the inlet condition of the turbine blade cooling passages. The test channel was heated by thin stainless steel foils with a thickness of 0.000025 m, and instrumented with 180 thermocouples. The brass ribs of a square cross-section were glued periodically, in line, onto the top and bottom walls of the foil-heated channel in patterns to achieve the desired spacing and angle-of-attack. The local heat transfer coefficients on the smooth side and the ribbed side walls, at the channel entrance and the downstream regions, were measured for eight rib configurations and three Reynolds numbers (Re = 10,000, 30,000, and 60,000).

Han, J. C.; Park, J. S.

1986-01-01

124

Nonequilibrium fluctuation-dissipation theorem and heat production.  

PubMed

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

Lippiello, E; Baiesi, M; Sarracino, A

2014-04-11

125

Measurements of the instantaneous local heat flux in turbulent Rayleigh-Bénard convection  

Microsoft Academic Search

We present measurements of the instantaneous local heat flux in highly turbulent Rayleigh-Bénard (RB) convection in air (Pr=0.7) for aspect ratios in the range 1.13<=Gamma<=9.00 and for Rayleigh numbers in the range 1.3×109<=Ra<=9.6×1011. The measurements have been carried out simultaneously at the surfaces of the heating and the cooling plate using a commercial sensor whose diameter is 360 times smaller

Ronald du Puits; Christian Resagk; André Thess

2010-01-01

126

Effect of nozzle geometry on local convective heat transfer to a confined impinging air jet  

Microsoft Academic Search

This article reports results on the effects of hyperbolic nozzle geometry on the local heat-transfer coefficients for confined impinging air jets. A thermochromatic liquid-crystal technique is used to visualize and record isotherms on a uniformly heated impingement surface. Experiments are conducted at low nozzle-to-plate spacings (0.25 < HD < 6.0) and Reynolds numbers in the range of 10,000 to 50,000

D. W. Colucci; R. Viskanta

1996-01-01

127

Numerical simulation of local heat transfer in rotating two-pass square channels.  

PubMed

3D turbulent air flow and heat transfer developing in a two-pass square channel rotating in the orthogonal mode are simulated using the high-Re k-epsilon turbulence model and a recently developed modification of wall functions. Auxiliary problem for accurate definition of inlet boundary conditions formed by a long unheated upstream section is considered. Details of flow structure are presented. Local heat transfer results are compared with experimental data. PMID:11460661

Kirillov, A I; Ris, V V; Smirnov, E M; Zaitsev, D K

2001-05-01

128

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

129

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. PMID:19967115

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

130

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

131

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

132

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

133

Computer simulation of pipe-bending processes with small bending radius using local induction heating  

Microsoft Academic Search

Through analyzing the stress state and deformation of pipe bending using local induction heating with small bending radius, a computer simulation system has been developed based on the FEM software ANSYS and finite strain elasto–plastic theory. The results, such as the thinning and thickening ratio of the pipe wall thickness, the pushing force with or without a reverse moment acting

Z Hu; J. Q Li

1999-01-01

134

Local Boiling and Cavitation in Heat-Induced Counterflow of He II  

Microsoft Academic Search

Local boiling, cavitation, and cavitation collapse have been observed in the heat induced counter-flow of He II in a convergent-divergent nozzle. These observations are described and shown to be qualitatively and quantitatively in agreement with the two fluid equations supplemented by the Gorter-Mellink force.

James E. Broadwell; Hans W. Liepmann

1969-01-01

135

Local effective dynamics of quantum systems: A generalized approach to work and heat  

E-print Network

By computing the local energy expectation values with respect to some local measurement basis we show that for any quantum system there are two fundamentally different contributions: changes in energy that do not alter the local von Neumann entropy and changes that do. We identify the former as work and the latter as heat. Since our derivation makes no assumptions on the system Hamiltonian or its state, the result is valid even for states arbitrarily far from equilibrium. Examples are discussed ranging from the classical limit to purely quantum mechanical scenarios, i.e. where the Hamiltonian and the density operator do not commute.

Hendrik Weimer; Markus J. Henrich; Florian Rempp; Heiko Schröder; Günter Mahler

2007-08-17

136

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

137

Local endwall heat/mass-transfer distributions in pin fin channels  

NASA Astrophysics Data System (ADS)

Naphthalene sublimination experiments were conducted to study the effects of the pin configuration, the pin length-to-diameter ratio, and the entrance length on local endwall heat/mass transfer in a channel with short pin fins (pin length-to-diameter ratios of 0.5 and 1.0). The detailed distributions of the local endwall heat/mass-transfer coefficient were obtained for staggered and aligned arrays of pin fins, for the spanwise pin spacing-to-diameter ratio of 2.5, and for streamwise pin spacing-to-diameter ratios of 1.25 and 2.5. The Reynolds numbers were kept at about 33,000. Overall- and row-averaged Nusselt numbers compared very well with those from previous heat-transfer studies.

Lau, S. C.; Kim, Y. S.; Han, J. C.

1987-10-01

138

Current localization, non-uniform heating, and failures of ZnO varistors  

SciTech Connect

Metal oxide varistors have highly nonlinear electrical characteristics and are widely used as devices for over-voltage protection. Varistor applications range from the use of small varistors to protect delicate electronic components to the use of much larger varistors for the protection of electrical-power-distribution systems. Non-uniform heating of ZnO varistors by electrical pulses occurs on three different spatial scales: (1) microscopic (sub-micron), (2) intermediate (sub-millimeter), and (3) macroscopic (of order of millimeters or centimeters). Heating on these scales has different origins and different consequences for device failure in large and small varistors. On the microscopic scale, the heating localizes in strings of tiny hot spots. They occur at the grain boundaries in a conducting path where the potential is dropped across Schottky-type barriers. These observations are interpreted by applying transport theory and using computer simulations. It is shown that the heat transfer on a scale of the grain size is too fast to permit temperature differences that could cause a varistor failure. On an intermediate size scale, the heating is most intense along localized electrical paths. The high electrical conductivity of these paths has microstructural origin, i.e., it derives from the statistical fluctuations of grain sizes and grain boundary properties. Current localization on the intermediate size scale appears to be significant only in small varistors. On the macroscopic scale, current localization in large blocks can be attributed to inhomogeneities in the electrical properties which originate during ceramic processing. The resulting non-uniform heating is shown to cause destructive failures of large varistor blocks.

Bartkowiak, M. [Univ. of Tennessee, Knoxville, TN (United States). Dept. of Physics and Astronomy]|[Oak Ridge National Lab., TN (United States). Solid State Div.

1997-11-01

139

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

140

Heat Production of Free Fermions Subjected to Electric Fields in Disordered Media  

E-print Network

Siqueira Pedra C. Kurig March 21, 2013 Abstract Electric resistance in conducting media is related to heatHeat Production of Free Fermions Subjected to Electric Fields in Disordered Media J.-B. Bru W. de in disordered media. More precisely, we investigate the heat production of the non-autonomous C­dynamical system

141

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

142

ensl-00151647,version1-5Jun2007 Lagrangian temperature, velocity and local heat flux measurement in  

E-print Network

laws which relate global heat flux and flow velocities to fluid properties, flow boundary geom- etryensl-00151647,version1-5Jun2007 Lagrangian temperature, velocity and local heat flux measurement.1 C). The Nusselt number, defined as the total heat flux normalized by T/H, is Nu = 167.9 ± 0.2. Under

Paris-Sud XI, Université de

143

Integration of autonomic and local mechanisms in regulating cardiovascular responses to heating and cooling in a reptile ( Crocodylus porosus )  

Microsoft Academic Search

Reptiles change heart rate and blood flow patterns in response to heating and cooling, thereby decreasing the behavioural cost of thermoregulation. We tested the hypothesis that locally produced vasoactive substances, nitric oxide and prostaglandins, mediate the cardiovascular response of reptiles to heat. Heart rate and blood pressure were measured in eight crocodiles ( Crocodylus porosus) during heating and cooling and

Frank Seebacher; Craig E. Franklin

2004-01-01

144

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

145

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

NASA Technical Reports Server (NTRS)

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

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

1999-01-01

146

Thermal parameters determination of battery cells by local heat flux measurements  

NASA Astrophysics Data System (ADS)

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

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

2014-12-01

147

Multi-fractal signal simulation of local, instantaneous heat transfer in a bubbling gas fluidized bed  

SciTech Connect

Recent investigations suggest that the mechanisms of heat transfer in bubbling gas fluidized beds exhibit characteristics consistent with chaos. Also, methods for simulating fractal time-series data have undergone significant development. In the present work, experimental time-series data were acquired using a constant temperature, platinum film heat flux probe flush mounted on a horizontal cylinder submerged in a bubbling gas fluidized bed. Analysis of the power spectra of the experimental signals suggests the existence of multi-fractal characteristics. Based on the fractal nature of chaotic systems, the multi-fractal Weierstrass-Mandelbrot (WM) function was used to simulate the scale-independent contribution to the local instantaneous heat transfer signals. The number of fractal components, the dimension of each fractal component and the range of frequencies associated with each fractal were determined from the power spectrum of an experimental signal. This information was subsequently used to simulate the multi-fractal contribution of an experimental signal.

Pence, D.V.; Beasley, D.E. [Clemson Univ., SC (United States)

1995-12-31

148

Inductive heat property of Fe 3O 4 nanoparticles in AC magnetic field for local hyperthermia  

Microsoft Academic Search

Magnetite (Fe3O4) nanoparticles with different magnetic properties were prepared by coprecipita-tion of Fe3 + and Fe2 + with aqueous NaOH solution. The inductive heat properties of Fe3O4 nanoparticles in an alternating current (AC) magnetic field were investigated for local hyperthermia. The maximum saturation magnetization Ms of Fe3O4 nanoparticles is 65.53 emu·g?1 under the optimum conditions of Fe3+\\/Fe2+ molar ratio at

Donglin ZHAO; Xianwei ZENG; Qisheng XIA; Jintian TANG

2006-01-01

149

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. PMID:18972332

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

2008-01-01

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

Characteristic of local boiling heat transfer of ammonia and ammonia / water binary mixture on the plate type evaporator  

NASA Astrophysics Data System (ADS)

Power generation using small temperature difference such as ocean thermal energy conversion (OTEC) and discharged thermal energy conversion (DTEC) is expected to be the countermeasures against global warming problem. As ammonia and ammonia/water are used in evaporators for OTEC and DTEC as working fluids, the research of their local boiling heat transfer is important for improvement of the power generation efficiency. Measurements of local boiling heat transfer coefficients were performed for ammonia /water mixture ( z = 0.9-1) on a vertical flat plate heat exchanger in a range of mass flux (7.5-15 kg/m2 s), heat flux (15-23 kW/m2), and pressure (0.7-0.9 MPa). The result shows that in the case of ammonia /water mixture, the local heat transfer coefficients increase with an increase of mass flux and composition of ammonia, and decrease with an increase of heat flux.

Okamoto, Akio; Arima, Hirofumi; Ikegami, Yasuyuki

2011-08-01

152

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

153

Natural convection in horizontal porous layers with localized heating from below  

SciTech Connect

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

Prasad, V. (Columbia Univ., New York, NY (United States)); Kulacki, F.A. (Univ. of Delaware, Newark (United States))

1987-08-01

154

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

155

SIGNATURES OF IMPULSIVE LOCALIZED HEATING IN THE TEMPERATURE DISTRIBUTION OF MULTI-STRANDED CORONAL LOOPS  

SciTech Connect

We study the signatures of coronal heating on the differential emission measure (DEM) by means of hydrodynamic simulations capable of resolving the chromospheric-corona transition region sections of multi-stranded coronal loops and following their evolution. We consider heating either uniformly distributed along the loop or localized close to the chromospheric footpoints, in both steady and impulsive regimes. Our simulations show that condensation at the top of the loop forms when the impulsive heating, with a pulse cadence lower than the plasma cooling time, is localized at the loop footpoints, and the pulse energy is below a threshold above which the heating balances the radiative losses, thus preventing the catastrophic cooling which triggers the condensation. A condensation does not produce observable signatures in the DEM because it does not redistribute the plasma over a sufficiently large temperature range. On the other hand, the DEM coronal peak is found sensitive to the pulse cadence time when this is longer or comparable to the plasma cooling time. In this case, the heating pulses produce large oscillations in temperature in the bulk of the coronal plasma, which effectively smears out the coronal DEM structure. The pronounced DEM peak observed in active regions would indicate a predominance of conditions in which the cadence time is shorter or of the order of the plasma cooling time, whilst the structure of the quiet-Sun DEM suggests a cadence time longer than the plasma cooling time. Our simulations give an explanation of the warm overdense and hot underdense loops observed by TRACE, SOHO, and Yohkoh. However, they are unable to reproduce both the transition region and the coronal DEM structure with a unique set of parameters, which outlines the need for a more realistic description of the transition region.

Susino, R.; Lanzafame, A. C. [Dipartimento di Fisica e Astronomia - Sezione Astrofisica, Universita di Catania, via S. Sofia 78, I-95123 Catania (Italy); Lanza, A. F.; Spadaro, D. [INAF-Osservatorio Astrofisico di Catania, via S. Sofia 78, I-95123 Catania (Italy)

2010-01-20

156

The effects of differentiated heat production on the stability of deep dense pools at the core-mantle boundary  

NASA Astrophysics Data System (ADS)

The formation of the continental and oceanic crust is a main source of chemical differentiation. Mantle convection both generates this heterogeneity by melting at plate boundaries and destroys it by convective mixing. Thermochemical convection models had been a useful tool to study the geochemical evolution of the earth, with tracers carrying the chemical information and combining geodynamics and geochemistry (e.g., Christensen and Hofmann, 1994; Brandenburg et al., 2008). Brandenburg et al., 2008 demonstrated that the creation and destruction of oceanic crust over the age of the Earth explains the radiogenic isotope characteristics of HIMU, EM1 and DMM reasonably well. The dense oceanic crust forms deep dense piles that seem similar to the large low velocity regions seen in seismology. In this study we have extended the Brandenburg et al. by taking into account the effects of differentiation on heat production. We use high resolution 2D finite element models that incorporate a very large number of active tracers, that carry information about the local density and heat production. Unlike the additional density carried by the tracer, which influences the flow instantaneously, the additional heat productivity influence the flow in a more gradual and integrated manner: tracer heating causes localized temperature increase, and then increase of buoyancy and decrease of viscosity as well. The piles of recycled oceanic crust carry higher concentration of radioactive elements. According to the thermochemical convection models from Christensen & Hofmann 1994 and Brandenburg et al. 2008, the piles of subducted slabs, featured by higher concentration of eclogite, always have higher temperature than the surroundings, as a result of long-term heating from the bottom(core). Radiogenic heating naturally further promotes this effect and destabilizes more rapidly the deep dense pools. Our work quantifies the relative density increase that is necessary to retain the deep pools and satisfy the geochemical, seismological and geodynamical constraints.

Hu, Z.; Van Keken, P. E.; Ballentine, C. J.; Hauri, E. H.

2011-12-01

157

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

Technology Transfer Automated Retrieval System (TEKTRAN)

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

158

Models relevant to excess heat production in fleischmann-pons experiments  

E-print Network

Observations of excess heat in the absence of commensurate energetic charged particles challenges local energy and momentum conservation, a foundation of nuclear physics. We have explored models based on excitation transfer, ...

Hagelstein, Peter L.

159

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

160

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 certain aspects of convective transport in a magma chamber. The authors 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 platform. An electrically heated strip, with a width equal to 1/4 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 distributions as well as overall heat transfer rates are presented. The experiment is numerically simulated through use of a finite element computer program. Numerically predicted steamlines, isotherms, and velocity distributions are presented for the transverse vertical midplane of the enclosure. Good agreement is demonstrated between predictions and measurements.

Chu, T.Y.; Hickox, C.F. (Sandia National Labs., Albuquerque, NM (United States))

1990-05-01

161

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

NASA Astrophysics Data System (ADS)

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 Pn method with ˜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 µm 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; Stölken, James; Vignes, Ryan

2011-03-01

162

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

163

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

164

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

165

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

166

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

SciTech Connect

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

Lara-Curzio, E., E-mail: laracurzioe@ornl.gov; May, A. F.; Delaire, O.; McGuire, M. A. [Materials Science and Technology Division, Oak Ridge National Laboratory, 1 Bethel Valley Rd., Oak Ridge, Tennessee 37831 (United States); Lu, X.; Liu, Cheng-Yun; Case, E. D.; Morelli, D. T. [Department of Chemical Engineering and Materials Science, Michigan State University, East Lansing, Michigan 48824 (United States)

2014-05-21

167

Heat conductivity from molecular chaos hypothesis in locally confined billiard systems  

E-print Network

We study the transport properties of a large class of locally confined Hamiltonian systems, in which neighboring particles interact through hard core elastic collisions. When these collisions become rare and the systems large, we derive a Boltzmann-like equation for the evolution of the probability densities. We solve this equation in the linear regime and compute the heat conductivity from a Green-Kubo formula. The validity of our approach is demonstated by comparing our predictions to the results of numerical simulations performed on a new class of high-dimensional defocusing chaotic billiards.

Thomas Gilbert; Raphael Lefevere

2008-10-14

168

Heat conductivity from molecular chaos hypothesis in locally confined billiard systems.  

PubMed

We study the transport properties of a large class of locally confined Hamiltonian systems, in which neighboring particles interact through hard-core elastic collisions. When these collisions become rare and the systems large, we derive a Boltzmann-like equation for the evolution of the probability densities. We solve this equation in the linear regime and compute the heat conductivity from a Green-Kubo formula. The validity of our approach is demonstrated by comparing our predictions with the results of numerical simulations performed on a new class of high-dimensional defocusing chaotic billiards. PMID:19113325

Gilbert, Thomas; Lefevere, Raphaël

2008-11-14

169

Localized Edge Vibrations and Edge Reconstruction by Joule Heating in Graphene Nanostructures  

NASA Astrophysics Data System (ADS)

Control of the edge topology of graphene nanostructures is critical to graphene-based electronics. A means of producing atomically smooth zigzag edges using electronic current has recently been demonstrated in experiments [Jia , Science 323, 1701 (2009)SCIEAS0036-807510.1126/science.1166862]. We develop a microscopic theory for current-induced edge reconstruction using density functional theory. Our calculations provide evidence for localized vibrations at edge interfaces involving unpassivated armchair edges. We demonstrate that these vibrations couple to the current, estimate their excitation by Joule heating, and argue that they are the likely cause of the reconstructions observed in the experiments.

Engelund, M.; Fürst, J. A.; Jauho, A. P.; Brandbyge, M.

2010-01-01

170

Boiling heat transfer in a vertical microchannel: Local estimation during flow boiling with a non intrusive method  

E-print Network

Boiling heat transfer in a vertical microchannel: Local estimation during flow boiling with a non densities. Indeed, microchannels are already attrac- tive in many domains such as: electronics cooling removal, and they have large heat dissipa- tion capabilities. Moreover, microchannels can be used

171

A study on the flow field and local heat transfer performance due to geometric scaling of centrifugal fans  

Microsoft Academic Search

Scaled versions of fan designs are often chosen to address thermal management issues in space constrained applications. Using velocity field and local heat transfer measurement techniques, the thermal performance characteristics of a range of geometrically scaled centrifugal fan designs have been investigated. Complex fluid flow structures and surface heat transfer trends due to centrifugal fans were found to be common

Jason Stafford; Ed Walsh; Vanessa Egan

172

New industrial heat pump applications to fructose production  

SciTech Connect

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

Not Available

1990-04-01

173

New industrial heat pump applications to textile production  

SciTech Connect

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

none,

1990-12-01

174

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

PubMed

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

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

2012-02-01

175

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

176

Reactive oxygen species (ROS) from NADPH and xanthine oxidase modulate the cutaneous local heating response in healthy humans.  

PubMed

Local cutaneous heating produces vasodilation that is largely nitric oxide (NO) dependent. We showed that angiotensin II (ANG II) attenuates this by an ANG II receptor, type 1 (AT1R)-dependent mechanism that is reversible with the antioxidant ascorbate, indicating oxidative stress. Reactive oxygen species (ROS) produced by ANG II employ NADPH and xanthine oxidase pathways. To determine whether these mechanisms pertain to skin, we measured cutaneous local heating with 10 ?M ANG II, using apocynin to inhibit NADPH oxidase and allopurinol to inhibit xanthine oxidase. We also inhibited superoxide with tempol, and H(2)O(2) with ebselen. We heated the skin of the calf in 8 healthy volunteers (24.5-29.9 yr old) to 42°C and measured local blood flow to assess the percentage of maximum cutaneous vascular conductance. We remeasured while perfusing allopurinol, apocynin, ebselen, and tempol through individual microdialysis catheters. This was then repeated with ANG II combined with antioxidant drugs. tempol and apocynin alone had no effect on the heat response. Allopurinol enhanced the entire response (125% of heat alone), while ebselen suppressed the heat plateau (76% of heat alone). ANG II alone caused significant attenuation of the entire heat response (52%). When added to ANG II, Allopurinol partially reversed the ANG II attenuation. Heat with ebselen and ANG II were similar to heat and ANG II; ebselen only partially reversed the ANG II attenuation. Apocynin and tempol each partially reversed the attenuation caused by ANG II. This suggests that ROS, produced by ANG II via NADPH and xanthine oxidase pathways, modulates the response of skin to the application of heat, and thus contributes to the control of local cutaneous blood flow. PMID:21436462

Medow, Marvin S; Bamji, Natasha; Clarke, Debbie; Ocon, Anthony J; Stewart, Julian M

2011-07-01

177

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

PubMed

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

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

2014-11-01

178

In vivo production of heat shock protein in mouse peritoneal macrophages by administration of lipopolysaccharide.  

PubMed Central

The in vivo production of heat shock protein was studied by administration of bacterial lipopolysaccharide (LPS) into mice. Heat shock protein 70 was detected in the extract of adherent peritoneal cells from mice injected intraperitoneally with LPS by using the immunoblotting method. The expression of heat shock protein 70 was found 2 days after injection of LPS and reached its peak 4 days after injection. The intraperitoneal injection of LPS induced the expression of heat shock protein 70, whereas its subcutaneous injection did not. The in vivo production of heat shock protein 70 was inhibited by administration of LPS together with quercetin, an inhibitor of accumulation of heat shock protein 70 mRNA. Tumor necrosis factor alpha enhanced LPS-induced heat shock protein production in vivo. There was a decrease of gamma delta T cells in the peritoneal cavity of mice injected intraperitoneally with LPS. It was suggested that bacterial LPS is a stressful agent which induces the in vivo heat shock protein response, and its administration leads to the production of heat shock protein 70 in peritoneal macrophages. PMID:7927668

Zhang, Y H; Takahashi, K; Jiang, G Z; Zhang, X M; Kawai, M; Fukada, M; Yokochi, T

1994-01-01

179

Local heat transfer distribution in a rotating serpentine rib-roughened flow passage  

NASA Astrophysics Data System (ADS)

Experiments are performed to determine the local heat transfer performance in a rotating serpentine passage with rib-roughened surfaces. The ribs are placed on the trailing and leading walls in a corresponding posited arrangement with an angle of attack of 90 deg. The rib height-to-hydraulic diameter ratio, e/D(h), is 0.0787, and the rib pitch-to-height ratio, s/e, is 11. The throughflow Reynolds number is varied, typically at 23,000, 47,000, and 70,000 in the passage both at rest and in rotation. In the rotation cases, the rotation number is varied from 0.023 to 0.0594. Results for the rib-roughened serpentine passages are compared with those of smooth ones in the literature. Comparison is also made on results for the rib-roughened passages between the stationary and rotating cases. It is disclosed that a significant enhancement is achieved in the heat transfer in both the stationary and rotating cases resulting from an installation of the ribs. Both the rotation and Rayleigh numbers play important roles in the heat transfer performance on both the trailing and leading walls. Although the Reynolds number strongly influences the Nusselt numbers in the rib-roughened passage of both the stationary and rotating cases, Nu(0) and Nu, respectively, it has little effect on their ratio Nu/Nu(0).

Zhang, N.; Chiou, J.; Fann, S.; Yang, W.-J.

1993-08-01

180

Local heating of human skin by millimeter waves: effect of blood flow.  

PubMed

We investigated the influence of blood perfusion on local heating of the forearm and middle finger skin following 42.25 GHz exposure with an open ended waveguide (WG) and with a YAV mm wave therapeutic device. Both sources had bell-shaped distributions of the incident power density (IPD) with peak intensities of 208 and 55 mW/cm(2), respectively. Blood perfusion was changed in two ways: by blood flow occlusion and by externally applied vasodilator (nonivamide/nicoboxil) cream to the skin. For thermal modeling, we used the bioheat transfer equation (BHTE) and the hybrid bioheat equation (HBHE) which combines the BHTE and the scalar effective thermal conductivity equation (ETCE). Under normal conditions with the 208 mW/cm(2) exposure, the cutaneous temperature elevation (DeltaT) in the finger (2.5 +/- 0.3 degrees C) having higher blood flow was notably smaller than the cutaneous DeltaT in the forearm (4.7 +/- 0.4 degrees C). However, heating of the forearm and finger skin with blood flow occluded was the same, indicating that the thermal conductivity of tissue in the absence of blood flow at both locations was also the same. The BHTE accurately predicted local hyperthermia in the forearm only at low blood flow. The HBHE made accurate predictions at both low and high perfusion rates. The relationship between blood flow and the effective thermal conductivity (k(eff)) was found to be linear. The heat dissipating effect of higher perfusion was mostly due to an apparent increase in k(eff). It was shown that mm wave exposure could result in steady state heating of tissue layers located much deeper than the penetration depth (0.56 mm). The surface DeltaT and heat penetration into tissue increased with enlarging the irradiating beam area and with increasing exposure duration. Thus, mm waves at sufficient intensities could thermally affect thermo-sensitive structures located in the skin and underlying tissue. PMID:15931684

Alekseev, S I; Radzievsky, A A; Szabo, I; Ziskin, M C

2005-09-01

181

About the possible options for models of convective heat transfer in closed volumes with local heating source  

NASA Astrophysics Data System (ADS)

Results of mathematical modeling of convective heat transfer in air area surrounded on all sides enclosing structures, in the presence of heat source at the lower boundary of the media are presented. Solved the system of differential equations of unsteady Navier-Stokes equations with the appropriate initial and boundary conditions. The process of convective heat transfer is calculated using the models of turbulence Prandtl and Prandtl-Reichard. Takes into account the processes of heat exchange region considered with the environment. Is carried out the analysis of the dimensionless heat transfer coefficient at interfaces "air - enclosures". The distributions average along the gas temperature range are obtained.

Maksimov, Vyacheslav I.; Nagornova, Tatiana A.; Shestakov, Igor A.

2015-01-01

182

Local microwave heating of sand molds as a means to overcome design limitations in sand mold casting  

NASA Astrophysics Data System (ADS)

Microwave induced selective heating outmatches conventional mold heating by convective heat transfer in means of energy efficiency and cycle time. Moreover, it provides the opportunity of a local manipulation of solidification and cooling processes within the sand casting mold. In this paper, we investigate the suitability of different highly absorbing materials to indirectly heat up the mostly microwave transparent sand mold. The temperature-dependent permittivity of the involved materials is determined by resonator experiments and subsequently used to simulate the electromagnetic field and the thermodynamic response of the sand mold prior to a metal casting process. Experimental results are presented and compared with the outcome of the coupled electromagnetic-thermodynamic simulations and the influence of local microwave heating on the solidification and cooling of the cast is studied.

Wiedenmann, O.; Ramakrishnan, R.; Saal, P.; K?l?ç, E.; Siart, U.; Eibert, T. F.; Volk, W.

2014-11-01

183

Development and demonstration of a Stirling/Rankine heat activated heat pump. Volume 1. Phase 2. Product development program. Final report  

SciTech Connect

This report presents the results of the Phase II and Phase IIIB Stirling/Rankine Heat Activated Heat Pump product development program. In the Phase II program, a complete gas fired heat activated prototype residential heat pump system was developed and tested. Results of the product system development are presented in Volume I of this report, emphasizing the key components of the system: the free piston Stirling engine prime mover and the free piston linear inertia compressor.

Not Available

1984-04-25

184

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

185

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

186

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

187

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

188

HEAT PRODUCTION FROM FORAGING ACTIVITY CONTRIBUTES TO THERMOREGULATION IN BLACK-CAPPED CHICKADEES  

Microsoft Academic Search

We measured metabolic heat produc- tion (Hm) of perching and foraging Black-capped Chickadees (Poecile atricapillus) to determine if the heat produced during foraging activity, or exercise thermogenesis, could replace thermoregulatory heat production requirements. Hm and activity of chick- adees in winter were measured at ambient tempera- tures (Ta) ranging from 211.5u to 15.5uC. Mean activity amplitude recorded with an activity

SHELDON J. COOPER; SARAH SONSTHAGEN

2007-01-01

189

Antagonism of soluble guanylyl cyclase attenuates cutaneous vasodilation during whole body heat stress and local warming in humans  

PubMed Central

We hypothesized that nitric oxide activation of soluble guanylyl cyclase (sGC) participates in cutaneous vasodilation during whole body heat stress and local skin warming. We examined the effects of the sGC inhibitor, 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ), on reflex skin blood flow responses to whole body heat stress and on nonreflex responses to increased local skin temperature. Blood flow was monitored by laser-Doppler flowmetry, and blood pressure by Finapres to calculate cutaneous vascular conductance (CVC). Intradermal microdialysis was used to treat one site with 1 mM ODQ in 2% DMSO and Ringer, a second site with 2% DMSO in Ringer, and a third site received Ringer. In protocol 1, after a period of normothermia, whole body heat stress was induced. In protocol 2, local heating units warmed local skin temperature from 34 to 41°C to cause local vasodilation. In protocol 1, in normothermia, CVC did not differ among sites [ODQ, 15 ± 3% maximum CVC (CVCmax); DMSO, 14 ± 3% CVCmax; Ringer, 17 ± 6% CVCmax; P > 0.05]. During heat stress, ODQ attenuated CVC increases (ODQ, 54 ± 4% CVCmax; DMSO, 64 ± 4% CVCmax; Ringer, 63 ± 4% CVCmax; P < 0.05, ODQ vs. DMSO or Ringer). In protocol 2, at 34°C local temperature, CVC did not differ among sites (ODQ, 17 ± 2% CVCmax; DMSO, 18 ± 4% CVCmax; Ringer, 18 ± 3% CVCmax; P > 0.05). ODQ attenuated CVC increases at 41°C local temperature (ODQ, 54 ± 5% CVCmax; DMSO, 86 ± 4% CVCmax; Ringer, 90 ± 2% CVCmax; P < 0.05 ODQ vs. DMSO or Ringer). sGC participates in neurogenic active vasodilation during heat stress and in the local response to direct skin warming. PMID:21292837

Zhao, Joan L.; Wu, Yubo; Johnson, John M.

2011-01-01

190

Effects of continental insulation and the partitioning of heat producing elements on the Earth's heat loss  

Microsoft Academic Search

Continental lithosphere influences heat loss by acting as a local insulator to the convecting mantle and by sequestering heat-producing radioactive elements from the mantle. Continental heat production can have a two-part effect since it decreases the amount of internal heat driving convection, which lowers mantle temperature, while also increasing the local insulating effect of continental lithosphere, which raises mantle temperature.

C. M. Cooper; A. Lenardic; L. Moresi

2006-01-01

191

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

NASA Astrophysics Data System (ADS)

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

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

2014-09-01

192

Immunoenzyme histochemical localization of fibrin degradation products in tissues.  

PubMed Central

An immunoenzyme histochemical study was conducted to localize fibrin degradation products (FDPs) in rat tissues during disseminated intravascular coagulation (DIC). Serial measurements of FDP levels in serum after thrombin-induced DIC showed peak levels to be found at 30 minutes; the FDPs were rapidly cleared from the circulation (half-life about one hour). Rat tissues obtained from 10 minutes to 3 hours after the induction of DIC were studied by means of immunohistochemistry. A method was developed to differentiate FDPs from fibrin in tissue sections. This method is based on the observation that, in paraplast-embedded tissues, FDPs can be demonstrated following ethanol fixation only, and that fibrin is demonstrable after both paraformaldehyde fixation and ethanol fixation. Moreover, FDPs will react to some of the antiserums employed only, while fibrin will react to all antiserum used (antiserums against fibrin monomer, against the constituent chains of fibrinogen, and against FDP-D and -E). At 10-20 minutes after the induction of DIC, FDPs were found in kidney proximal tubule epithelial cells. These FDPs could be demonstrated using antiserum against the constituent chains of fibrinogen, but not by antiserums against FDP-D or -E. At 30-90 minutes, FDPs were found inside liver macrophages. The FDPs in liver did not react to anti-chain antiserums, though they did react to antiserums against FDP-D and -E. Since no FDPs were found in other tissues, rat FDPs are apparently cleared by kidney (earlier phase) and liver (later phase) only. In human cases of DIC, FDPs, could be demonstrated in kidney proximal tubules cells and in liver macrophages as well. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 PMID:7015871

Emeis, J. J.; Lindeman, J.; Nieuwenhuizen, W.

1981-01-01

193

FARM NET INCOME IMPACT OF SWITCHGRASS PRODUCTION AND CORN STOVER COLLECTION FOR HEAT AND POWER GENERATION  

E-print Network

and Corn Stover Collection for Heat and Power Generation Mitchell A. Myhre Advisor: Associate ProfessorFARM NET INCOME IMPACT OF SWITCHGRASS PRODUCTION AND CORN STOVER COLLECTION FOR HEAT AND POWER GENERATION by Mitchell A. Myhre A thesis submitted in partial fulfillment of the requirements for the degree

Wisconsin at Madison, University of

194

The use of plate heat exchangers to improve energy efficiency in phosphoric acid production  

Microsoft Academic Search

This paper originated as a part of a comprehensive research project designed to develop ecologically sustainable, environmentally friendly, resource- and energy-saving industrial process technology for the production of a wide class of phosphorus containing substances. The essential feature of the research was designed for the replacement of tubular heat exchangers with Plate heat exchangers (PHEs) and for the installation of

Petro Kapustenko; Stanislav Boldyryev; Olga Arsenyeva; Gennadiy Khavin

2009-01-01

195

Catalyzed deuterium-deuterium and deuterium-tritium fusion blankets for high temperature process heat production  

Microsoft Academic Search

Tritiumless blanket designs, associated with a catalyzed deuterium-deuterium (D-D) fusion cycle and using a single high temperature solid pebble or falling bed zone, for process heat production, are proposed. Neutronics and photonics calculations, using the Monte Carlo method, show that an about 90% heat deposition fraction is possible in the high temperature zone, compared to a 30 to 40% fraction

M. M. H. Ragheb; B. Salimi

1982-01-01

196

All local quantum states are mixtures of direct products  

E-print Network

According to Popescu's recent analysis [Phys. Rev. Lett. {\\bf72}, 797 (1994)], {\\it nonideal} measurements, rather than ideal ones, may be more sensitive to reveal nonlocal correlations between distant parts of composite quantum systems. The outcome statistics of joint nonideal measurements on local states should by definition admit local hidden variable models. We prove that the density operator of a local composite system must be convex mixture of the subsystems' density operators. This result depends essentially on a plausible consistency condition restricting the class of admissible local hidden variable models.

Lajos Diosi

1995-06-06

197

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

198

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

NASA Astrophysics Data System (ADS)

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

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

2013-04-01

199

Wavelet-analysis of skin temperature oscillations during local heating for revealing endothelial dysfunction.  

PubMed

Skin microvessels have proven to be a model to investigate the mechanisms of vascular disease; in particular, endothelial dysfunction. To analyze skin blood flow, high-resolution thermometry can be used because low-amplitude skin temperature oscillations are caused by changes in the tone of skin vessels. The aim of our study was to test the possibilities of wavelet analysis of skin temperature (WAST) for the diagnosis of impaired regulation of microvascular tone in patients with type 2 diabetes. A local heating functional test was used for the assessment of microvascular tone regulation. A control group consisted of healthy male and female volunteers (n=5 each), aged 39.1±5.3years. A group of patients with type 2 diabetes comprised thirteen people, seven men and six women, aged 36 to 51years old (43.2±3.4years). The diagnosis of diabetes was made according to the criteria of the World Health Organization (WHO). The mean disease duration was 7.36±0.88years. Skin temperature oscillations, reflecting intrinsic myogenic activity (0.05-0.14Hz), neurogenic factors (0.02-0.05Hz) and endothelial activity (0.0095-0.02Hz) increase greatly during local heating for healthy subjects. In the group of patients with type 2 diabetes, no statistically significant differences in the amplitudes in the endothelial range were observed. Relative changes in the oscillation amplitudes in patients with type 2 diabetes were markedly lower compared to the control group. The latter indicates that the WAST method enables assessment of the state of vascular tone and the effects of mechanisms responsible for regulation of blood flow in the microvasculature. PMID:25446367

Podtaev, Sergey; Stepanov, Rodion; Smirnova, Elena; Loran, Evgenia

2015-01-01

200

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

NASA Technical Reports Server (NTRS)

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

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

1990-01-01

201

A Simple Calorimeter for the Simultaneous Determination of Heat Loss and Heat Production in Animals  

Microsoft Academic Search

This paper describes a new type of gradient calorimeter which permits the rapid simultaneous measurement of respiratory metabolism and heat loss. It uses the temperature difference between the inner and outer aspect of a fixed transitional layer of air rather than adiabatic principles. (W. O. Atwater and F. G. Benedict, ``A respiration calorimeter with appliances for the direct determination of

Lawrence R. Prouty; Martha J. Barrett; James D. Hardy

1949-01-01

202

Phenomenological Approach to Heat Conduction in a One-Dimensional Hard-Point Gas beyond Local Equilibrium  

NASA Astrophysics Data System (ADS)

Molecular dynamics simulation data on stationary heat conduction in a one-dimensional binary hard-point gas are studied: We estimate the validity range of the local equilibrium assumption explicitly. The temperature profiles with the temperature jumps at the boundaries are analyzed consistently by a phenomenological theory beyond the local equilibrium assumption (extended thermodynamics). The agreement between the numerical result of the temperature profiles and its theoretical prediction is fairly well. The heat conductivity is analyzed in two limiting cases: We find that the exponent, which characterizes the divergence of the heat conductivity in a thermodynamic limit, depends on the mass ratio of two different constituent particles. We also find a power law relation between the heat conductivity and the mass ratio in a limit to the system where energy transport is in a ballistic mode.

Taniguchi, Shigeru; Nakamura, Masashi; Sugiyama, Masaru; Isobe, Masaharu; Zhao, Nanrong

2008-01-01

203

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

204

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

205

Theoretical analysis of the microwave-drill near-field localized heating effect  

NASA Astrophysics Data System (ADS)

The microwave-drill principle [Jerby et al., Science 298, 587 (2002)] is based on a localized hot-spot effect induced by a near-field coaxial applicator. The microwave drill melts the nonmetallic material locally and penetrates mechanically into it to shape the hole. This paper presents a theoretical analysis of the thermal-runaway effect induced in front of the microwave drill. The model couples the Maxwell's and heat equations including the material's temperature-dependent properties. A finite-difference time-domain algorithm is applied in a two-time-scale numerical model. The simulation is demonstrated for mullite, and benchmarked in simplified cases. The results show a temperature rise of ˜103K/s up to 1300K within a hot spot confined to a ˜4-mm width (˜0.1 wavelength). The input-port response to this near-field effect is modeled by equivalent time-varying lumped-circuit elements. Besides the physical insight, this theoretical study provides computational tools for design and analysis of microwave drills and for their real-time monitoring and adaptive impedance matching.

Jerby, E.; Aktushev, O.; Dikhtyar, V.

2005-02-01

206

Enacting Music Scenes: Mobility, Locality and Cultural Production  

Microsoft Academic Search

Cluster theories assume ‘locality’ to be a bounded and fixed spatiality characterized by shared worlds-of-life, strong ties and co-presence. This paper contests the immobility of such a definition. Drawing on the case of Santiago’s experimental music scene, in Chile, I argue for a mobile, transient and fluid approach to localized (cultural) economies. The empirical evidence indicates that Santiago’s experimental music

Manuel Tironi

2012-01-01

207

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

208

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

NASA Astrophysics Data System (ADS)

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

Anders, André

2014-12-01

209

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

PubMed

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

Casey, T M

1976-06-01

210

Impact of Heat Stress on Production and Fertility of Dairy Cattle  

Microsoft Academic Search

Summer heat stress depresses both milk production and reproductive performance of dairy cows. The use of efficient cooling systems is required because high milk-producing cows are not capable of maintaining normothermia in the summer. Cooling, if efficient enough, is capable of narrowing the gap between winter and summer milk production; however, its positive effect on fertility is limited. Fertility surveys

David Wolfenson

211

Using heat demand prediction to optimise Virtual Power Plant production capacity  

E-print Network

1 Using heat demand prediction to optimise Virtual Power Plant production capacity Vincent Bakker. By combining a group of micro-generators, a Virtual Power Plant can be formed. The electricity market/network requires a VPP control system to be fast, scalable and reliable. It should be able to adjust the production

Al Hanbali, Ahmad

212

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. PMID:22408589

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

2011-01-01

213

The locality axiom in quantum field theory and tensor products of C*-algebras  

NASA Astrophysics Data System (ADS)

The prototypes of mutually independent systems are systems which are localized in spacelike separated regions. In the framework of locally covariant quantum field theory, we show that the commutativity of observables in spacelike separated regions can be encoded in the tensorial structure of the functor which associates unital C*-algebras (the local observable algebras) to globally hyperbolic spacetimes. This holds under the assumption that the local algebras satisfy the split property and involves the minimal tensor product of C*-algebras.

Brunetti, Romeo; Fredenhagen, Klaus; Imani, Paniz; Rejzner, Katarzyna

2014-06-01

214

The Locality Axiom in Quantum Field Theory and Tensor Products of $C^*$-algebras  

E-print Network

The prototype of mutually independent systems are systems which are localized in spacelike separated regions. In the framework of locally covariant quantum field theory we show that the commutativity of observables in spacelike separated regions can be encoded in the tensorial structure of the functor which associates unital $C^*$-algebras (the local observable algebras) to globally hyperbolic spacetimes. This holds under the assumption that the local algebras satisfy the split property and involves the minimal tensor product of $C^*$-algebras.

Romeo Brunetti; Klaus Fredenhagen; Paniz Imani; Katarzyna Rejzner

2012-06-24

215

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

216

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

EPA Science Inventory

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

217

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

SciTech Connect

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

Shaw, H.L.

1980-12-23

218

Heat production in chemically skinned smooth muscle of guinea-pig taenia coli.  

PubMed Central

1. The rate of heat production of chemically skinned guinea-pig taenia coli smooth muscle at 25 degrees C was measured using microcalorimetric techniques. 2. Muscle strips were mounted isometrically and incubated in solutions containing MgATP (3.2 mM) and phosphocreatine (PCr, 12 mM), pH 6.9. Activation was obtained by the injection of Ca2+ into the sample compartment of the calorimeter. 3. The heat production rate of the resting preparation (pCa 9) was 0.40 +/- 0.03 mW g-1 wet weight (n = 23). During maximal activation (pCa 4.8) the heat rate increased to 1.12 +/- 0.07 mW g-1 (mean +/- S.E.M., n = 15). With stepwise increase in [Ca2+] from pCa 9 to 4.8 the energetic cost of force maintenance tended to increase at higher [Ca2+]. 4. After activation by Ca2+, the heat production rate reached its maximum while force was still increasing. 5. Changing ionic strength from 90 to 150 mM had no effect on either basal or activated heat rate. Oligomycin, amphotericin B and the adenylate kinase inhibitor Ap5A had no effect on the basal heat rate. 6. Exchanging ATP in the incubation medium for inosine triphosphate (ITP) reduced the force and heat production after injection of Ca2+. The basal heat production was not lowered when ATP was exchanged for ITP. 7. The observed enthalpy change for PCr splitting at 25 degrees C (pH 6.9, ionic strength 90 mM) was -28 +/- 3 kJ mol-1 (mean +/- S.E.M., n = 9). After correction for the phosphate equilibrium, buffer reactions, and Mg2+ binding to PCr and HPO42-, the net enthalpy change is calculated to be -39 +/- 3 kJ mol-1. 8. Heat production in the skinned smooth muscle consists of one basal component present in relaxed muscle, and one component associated with contraction. The nature of the basal heat production is unclear but does not seem to involve turnover of phosphate on the myosin light chains. The increase in the energetic tension cost with increasing activation by Ca2+ has implications for the understanding of the contractile mechanism in smooth muscle. PMID:1804969

Lönnbro, P; Hellstrand, P

1991-01-01

219

Heat management for hydrogen production by high temperature steam electrolysis  

Microsoft Academic Search

Many research and development projects throughout the world are devoted to sustainable hydrogen production processes. Low-temperature electrolysis, when consuming electricity produced without greenhouse gas emissions, is a sustainable process, though having limited efficiency.The performance of electrolysis processes can be improved by functioning at high temperature (high-temperature electrolysis, HTE). This leads to a reduction in energy consumption but requires some of

Christine Mansilla; Jon Sigurvinsson; André Bontemps; Alain Maréchal; François Werkoff

2007-01-01

220

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

Microsoft Academic Search

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

Hüseyin Yapici; Nesrin Kayatas; Gamze Bastürk; Nafiz Kahraman

2006-01-01

221

Local heat-transfer characteristics of a row of circular air jets impinging on a concave semicylindrical surface  

NASA Technical Reports Server (NTRS)

An experimental study was made of the local heat-transfer characteristics of air jets impinging on the concave side of a right circular semicylinder. A correlation was developed for expressing individual and combined effects of a number of dimensionless variables on the normalized Nusselt number distributions. Results of the present study are in good agreement with those of other investigators.

Livingood, J. N. B.; Gauntner, J. W.

1973-01-01

222

608 IEEE TRANSACTIONS ON ADVANCED PACKAGING, VOL. 23, NO. 4, NOVEMBER 2000 MEMS Post-Packaging by Localized Heating and  

E-print Network

608 IEEE TRANSACTIONS ON ADVANCED PACKAGING, VOL. 23, NO. 4, NOVEMBER 2000 MEMS Post-Packaging by Localized Heating and Bonding Liwei Lin Abstract--This work addresses important post-packaging issues of microelectromechanical systems (MEMS). Establishing a versatile post-packaging process not only advances the field

Lin, Liwei

223

Localization and expression of heat shock protein 70 with rat myocardial cell damage induced by heat stress in vitro and in vivo.  

PubMed

The aim of the present study was to investigate the association between heat shock protein (Hsp) 70 expression kinetics and heat stress?induced damage to rat myocardial cells in vitro and in vivo. The results showed that the activity of heart injury?associated enzymes, including aspartate aminotransferase and creatine kinase, significantly increased and myocardial cells developed acute histopathological lesions; this therefore suggested that heat stress altered the integrity of myocardial cells in vitro and in vivo. Levels of Hsp70 in vitro decreased following the initiation of heat stress and then steadily increased until heat stress ceased at 100 min; however, in vivo studies demonstrated a gradual increase in Hsp70 levels in the heart cells of rats from the initiation of heat stress, followed by a sharp decline at 100 min. These results indicated that the cells sustained different degrees of injury in vivo compared with those sustained in vitro, this may be due to different regulatory mechanisms in the two environments. Intracytoplasmic Hsp70 signaling was significantly reduced at 60 min in vitro, compared with that of the in vivo study, indicating that Hsp70 consumption may have exceeded its production prior to 60 min of heat stress, and following 60 min the cells produced sufficient Hsp70 protein for their protection against heat stress. Hsp70?positive signals in the cytoplasm of heart cells in vivo were more prominent in the intact areas compared with those of the degenerated areas and the density of Hsp70?positive signals was significantly reduced following 60 min of heat stress. In conclusion, comprehensive comparisons of enzymes, cell morphology and Hsp70 levels indicated that decreased levels of Hsp70 were associated with the reduced protective effect on myocardial cells in vitro and in vivo. PMID:25412361

Chen, Hongbo; Adam, Abdelnasir; Cheng, Yanfen; Tang, Shu; Hartung, Jörg; Bao, Endong

2015-03-01

224

Biohydrogen production from sewage sludge using a continuous hydrogen fermentation system with a heat treatment vessel  

Microsoft Academic Search

An anaerobic hydrogen fermentation system with a thermophilic flow-through reactor (55°C) for hydrogen production and a boiling\\u000a retention vessel (100°C) for continuous heat treatment, was studied for enhanced continuous hydrogen fermentation using sewage\\u000a sludge. The performance of the hydrogen fermentation system was tested at various Hydraulic Retention Times (HRTs) ranged\\u000a from 1 to 5 days. The heat treatment of the

Jung-Hui Woo; Young-Chae Song

2010-01-01

225

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

NASA Astrophysics Data System (ADS)

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

Maksimov, Vyacheslav I.; Nagornov, Dmitriy A.

2014-08-01

226

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

227

Production of heat shock proteins, cytokines, and nitric oxide in toxic stress.  

PubMed

Expression of heat shock proteins Hsp27, Hsp90, and Hsp70 and production of tumor necrosis factors (TNF-alpha, TNF-beta), interferon-gamma (IFN-gamma), interleukin-2, -3, -6, and nitric oxide (NO) were studied under conditions of acute and chronic intoxication of animals with lipopolysaccharides. Injection of endotoxin increased expression of heat shock proteins Hsp70 and Hsp90-alpha in mouse cells. Acute toxic stress also provoked a sharp increase in the production of TNF-alpha, TNF-beta, and NO in mouse cells. The production of other cytokines (interleukins and IFN-gamma) was changed insignificantly. In the model of chronic toxic stress, changes in the production of Hsp70, Hsp90, TNF, and NO were followed during 11 days after the beginning of the toxin injections. The expression of Hsp70 and Hsp90 in acute stress was significantly higher than at the final stage of the chronic exposure. The changes in the TNF and NO productions, on one hand, and the production of heat shock proteins, on the other hand, were synchronous. The findings indicate that repeated injections of increasing endotoxin doses result in a decreased ability of the body cells to respond to stress by overproduction of heat shock proteins, TNF, and NO. PMID:16615857

Novoselova, E G; Glushkova, O V; Cherenkov, D A; Parfenyuk, S B; Novoselova, T V; Lunin, S M; Khrenov, M O; Guzhova, I V; Margulis, B A; Fesenko, E E

2006-04-01

228

Evaluation of Cyanogenic Potentials of Local Cassava Species and Residual Cyanide Contents of Their Locally Processed Food Products in Southeast Nigeria  

Microsoft Academic Search

The cyanogenic potentials and residual cyanide contents of local cassava parenchyma and their locally processed food products in southeastern Nigeria were studied. Seven species of cassava locally grown and four main food products from them were analyzed colourimetrically for their cyanide contents. Results of the analyses indicated that five of the species contain cyanide potentials between 50 and 100 mg HCN\\/kg

Nwachukwu R. Ekere; Ifeanyi S. Eze

2012-01-01

229

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

230

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

231

Consistent Pattern of Local Adaptation during an Experimental Heat Wave in a Pipefish-Trematode Host-Parasite System  

PubMed Central

Extreme climate events such as heat waves are expected to increase in frequency under global change. As one indirect effect, they can alter magnitude and direction of species interactions, for example those between hosts and parasites. We simulated a summer heat wave to investigate how a changing environment affects the interaction between the broad-nosed pipefish (Syngnathus typhle) as a host and its digenean trematode parasite (Cryptocotyle lingua). In a fully reciprocal laboratory infection experiment, pipefish from three different coastal locations were exposed to sympatric and allopatric trematode cercariae. In order to examine whether an extreme climatic event disrupts patterns of locally adapted host-parasite combinations we measured the parasite's transmission success as well as the host's adaptive and innate immune defence under control and heat wave conditions. Independent of temperature, sympatric cercariae were always more successful than allopatric ones, indicating that parasites are locally adapted to their hosts. Hosts suffered from heat stress as suggested by fewer cells of the adaptive immune system (lymphocytes) compared to the same groups that were kept at 18°C. However, the proportion of the innate immune cells (monocytes) was higher in the 18°C water. Contrary to our expectations, no interaction between host immune defence, parasite infectivity and temperature stress were found, nor did the pattern of local adaptation change due to increased water temperature. Thus, in this host-parasite interaction, the sympatric parasite keeps ahead of the coevolutionary dynamics across sites, even under increasing temperatures as expected under marine global warming. PMID:22303448

Landis, Susanne H.; Kalbe, Martin; Reusch, Thorsten B. H.; Roth, Olivia

2012-01-01

232

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

233

CARTOGRAPHIC LANGUAGE AND PRODUCTION OF KNOWLEDGE: TEACHING LOCAL GEOGRAPHY WITH A MUNICIPAL SCHOOL ATLAS  

Microsoft Academic Search

At events on School Cartography in Brazil, local school atlases have been one of the subjects most frequently presented. However, further research is necessary to elucidate how these materials can be used in teachers' practices. To this end, a collaborative research was conducted involving fifteen teachers, to investigate the production of knowledge about space based on a local atlas. This

Rosângela Doin de Almeida

234

Seasonal and acute heat stress effects on steroid production by dominant follicles in cows.  

PubMed

The present study concerned the seasonal and acute effects of heat stress on steroid concentrations in follicular fluid and on steroid production by granulosa and theca interna cells, in bovine dominant follicles. Three groups of cows were studied: summer (n = 5), autumn (n = 5) and winter (n = 9) cows. During the winter season, another group of cows was acutely heat-stressed from days 3 through 5 of the estrous cycle (n = 5). On day 7 of the estrous cycle, follicular fluid from first-wave dominant follicles was aspirated, and dispersed granulosa and theca cells from each seasonal group were incubated for 18 h at normothermic (37.5 degrees C) or high (40.5 degrees C) temperatures. Cells were incubated in media only or in media containing testosterone (300 ng ml-1, for granulosa cells) or forskolin (4 micrograms ml-1, for theca cells). In follicular fluid the 17 beta-estradiol concentration was high (P < 0.05) in winter and low in autumn, and summer, the androstenedione concentration was high in summer (P < 0.05), low in autumn, and intermediate in winter. During the winter season, acute in vivo heat stress increased follicular fluid androstenedione and decreased estradiol to levels comparable with those prevailing in summer. Basal and forskolin-stimulated androstenedione production by theca cells was higher (P < 0.05) in the winter group than in the summer and autumn groups, and also higher than in the cows that were heat-stressed during winter, which suggests that theca cell function is susceptible to chronic (summer), short-term (winter) and delayed (autumn) heat stresses. In vitro incubation at high temperature (40.5 degrees C) reduced the high, forskolin-stimulated androstenedione production in winter (P < 0.05). Estradiol production by granulosa cells was high in winter and autumn, and low in summer (P < 0.05). Acute heat stress in winter did not alter estradiol production relative to winter controls, whereas a high incubation temperature (40.5 degrees C) reduced (P < 0.05) estradiol production only in the autumn, when the highest production rate was recorded. The results indicate a differential effect of heat stress on the functions of granulosa and theca cells. Both concurrent and delayed effects of heat stress on the steroidogenic capacity of ovarian follicles in cattle are presented. PMID:9233502

Wolfenson, D; Lew, B J; Thatcher, W W; Graber, Y; Meidan, R

1997-05-01

235

Molecular epidemiology and heat resistance of Listeria monocytogenes in meat products and meat-processing plants and listeriosis in Latvia.  

E-print Network

??The prevalence, contamination and heat resistance of Listeria monocytogenes were investigated in meat products and meat-processing plants. Moreover, trends of human listeriosis in Latvia were… (more)

Berzins, Aivars

2010-01-01

236

Production of 5'-phosphodiesterase by Catharanthus roseus cells promoted by heat-degraded products generated from uronic acid.  

PubMed

Polyalginate was autoclaved at 121 degrees C for 20 min and its molecular weight distribution was analyzed. The autoclaved alginate yielded alginate polymer, oligomer and heat degraded products (HDPs). Each of the separated substances promoted 5'-phosphodiesterase (5'-PDase) production in suspension culture of Catharanthus roseus cells. HDPs could also be generated from other uronic acids (galacturonic acid and glucuronic acid) by autoclave treatment. The most effective substance in the HDPs was isolated and characterized as trans-4,5-dihydroxy-2-cyclopenten-1-one (DHCP). The optimal conditions for DHCP production were also established (autoclaving 1 mg/ml monogalacturonic acid [pH 2] at 121 degrees C for 2 h). A combination of oligo-alginate (below 4 kDa) and HDPs significantly promoted the production of 5'-PDase in C. roseus. Based on the above results, a novel alginate complex that gave a 44-fold increase in 5'-PDase production by C. roseus was developed. PMID:16233285

Akimoto-Tomiyama, Chiharu; Aoyagi, Hideki; Ozawa, Tetsuo; Tanaka, Hideo

2002-01-01

237

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

238

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

239

Delayed effect of heat stress on steroid production in medium-sized and preovulatory bovine follicles.  

PubMed

During the autumn, the conception rate of dairy cattle in warm countries is low although ambient temperatures have decreased and cows are no longer exposed to summer thermal stress, indicating that there may be a delayed effect of heat stress on cattle fertility. Two experiments were conducted to examine possible delayed effects of heat stress on follicular characteristics and steroid production at two distinct stages of follicular growth: medium-sized and preovulatory follicles, 20 and 26 days after heat exposure, respectively. Lactating cows were subjected to heat stress for 12 h a day in an environmental chamber, during days 2-6 of a synchronized oestrous cycle. In Expt 1, ovaries were collected on day 3 of the subsequent cycle, before selection of the dominant follicle, and medium-sized follicles were classified as atretic or healthy. In Expt 2, on day 7 of the subsequent cycle, PGF(2a) was administered and preovulatory follicles were collected 40 h later. In both experiments, follicular fluid was aspirated, granulosa and thecal cells were incubated, and steroid production was determined. In healthy medium-sized follicles (Expt 1), oestradiol production by granulosa cells and androstenedione production by thecal cells were lower (P < 0.05) and the concentration of progesterone in the follicular fluid was higher in cows that had been previously heat-stressed than in control cows (P < 0.05). In preovulatory follicles (Expt 2), the viability of granulosa cells was lower (P < 0.05) and the concentration of androstenedione in the follicular fluid and its production by thecal cells were lower (P < 0.05) in cows that had been previously heat-stressed than in control cows. In both experiments, the oestradiol concentrations in the follicular fluids were not altered by heat stress. These results demonstrate a delayed effect of heat stress on steroid production and follicular characteristics in both medium-sized and preovulatory follicles; this effect could be related to the low fertility of cattle in the autumn. PMID:11427162

Roth, Z; Meidan, R; Shaham-Albalancy, A; Braw-Tal, R; Wolfenson, D

2001-05-01

240

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. PMID:24039465

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

2006-01-01

241

Combined Heat and Power (CHP), also known as cogeneration, is the concurrent production of electricity or  

E-print Network

movers or technology types, which include: Reciprocating Engines Combustion or Gas Turbines Steam systems can provide the following products: Electricity Direct mechanical drive Steam or hot water, integrated systems that consist of various components ranging from prime mover (heat engine), generator

242

Volatile production during preignition heating. Final technical report, 15 September 1980-30 September 1982  

SciTech Connect

Pulverized coal particles, in a flowing inert nitrogen stream, have been heated by high power Carbon Dioxide Laser. The consequence of such an irradiation have proved to be both novel and surprising as a result of the rapid quenching of primary coal products. It ahs been found that the gas phase yield from such heating (typically, temperatures in excess of 1400 K at rates approx. 2 x 10/sup 5/ K/s) is very small (< 0.2 percent of coal carbon and hydrogen). Analysis of the solid residue has shown the presence of fine lacy particulate chains of material of 0.1 ..mu..m diameter, which appears to be soluble in tetrahydrofuran. The yields of solute were significantly much higher than for raw coals. Molecular weight of the solute material was high, being in the range of 600 to 3000. The above and substantiating evidence point to a new mechanism of high heating rate pyrolysis in which only tar-like materials are produced as primary products from the coal. It is hypothesized that gas phase products are primarily the result of secondary reactions of these primary products in the hot gas environments usually employed by other heating techniques.

Ballantyne, A.; Chou, H.; Flusberg, A.; Neoh, K.; Orozco, N.; Stickler, D.

1983-10-01

243

Seasonal and acute heat stress effects on steroid production by dominant follicles in cows  

Microsoft Academic Search

The present study concerned the seasonal and acute effects of heat stress on steroid concentrations in follicular fluid and on steroid production by granulosa and theca interna cells, in bovine dominant follicles. Three groups of cows were studied: summer (n = 5), autumn (n = 5) and winter (n = 9) cows. During the winter season, another group of cows

D. Wolfenson; B. J. Lew; W. W. Thatcher; Y. Graber; R. Meidan

1997-01-01

244

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

SciTech Connect

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

Anders, Andre

2014-12-07

245

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

246

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

247

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

248

Response of Cell Division and Cell Expansion to Local Fruit Heating in Tomato Fruit  

Microsoft Academic Search

To improve our understanding of fruit growth responses to temperature, it is important to analyze temperature effects on underlying fruit cellular processes. This study aimed at analyzing the response of tomato (Solanum lycopersicum) fruit size to heating as affected by changes in cell number and cell expansion in different directions. Individual trusses were enclosed into cuvettes and heating was applied

J. Fanwoua; Visser de P. H. B; E. Heuvelink; G. C. Angenent; X. Yin; L. F. M. Marcelis; P. C. Struik

2012-01-01

249

Modeling the Daly Gap: The Influence of Latent Heat Production in Controlling Magma Extraction and Eruption  

NASA Astrophysics Data System (ADS)

A century-old issue in volcanology is the origin of the gap in chemical compositions observed in magmatic series on ocean islands and arcs - the "Daly Gap". If the gap forms during differentiation from a mafic parent, models that predict the dynamics of magma extraction as a function of chemical composition must simulate a process that results in volumetrically biased, bimodal compositions of erupted magmas. The probability of magma extraction is controlled by magma dynamical processes, which have a complex response to magmatic heat evolution. Heat loss from the magmatic system is far from a simple, monotonic function of time. It is modified by the crystallization sequence, chamber margin heat flux, and is buffered by latent heat production. We use chemical and thermal calculations of MELTS (Ghiorso & Sack, 1995) as input to the physical model of QUANTUM (Dufek & Bachmann, 2010) to predict crystallinity windows of most probable magma extraction. We modeled two case studies: volcanism on Tenerife, Canary Islands, and the Campanian Ignimbrite (CI) of Campi Flegrei, Italy. Both preserve a basanitic to phonolitic lineage and have comparable total alkali concentrations; however, CI has high and Tenerife has low K2O/Na2O. Modeled thermal histories of differentiation for the two sequences contrast strongly. In Tenerife, the rate of latent heat production is almost always greater than sensible heat production, with spikes in the ratio of latent to sensible heats of up to 40 associated with the appearance of Fe-Ti oxides at near 50% crystallization. This punctuated heat production must cause magma temperature change to stall or slow in time. The extended time spent at ?50% crystallinity, associated with dynamical processes that enhance melt extraction near 50% crystallinity, suggests the magma composition at this interval should be common. In Tenerife, the modeled composition coincides with that of the first peak in the bimodal frequency-composition distribution. In our model, we move the extracted liquid to a shallower chamber (1.5 kbar as inferred for Tenerife phonolite) and resume crystallization. At the optimal magma extraction window of ?50% crystallinity, the composition matches well with the observed composition of the second peak of the bimodal distribution. In contrast, CI does not show an early spike in latent heat production, but a late (?900°C) pseudo-invariant point where latent heat production spikes. This spike is very near the 50% crystallinity window, again enhancing the probability of magma extraction. The model liquid composition at this crystallinity matches the observed trachyte composition. In both systems, phase chemistry supports a two-chamber evolution, one deep and the second shallow, corresponding to two primary melt extraction events. Realistically incorporating chemical, thermal and physical processes in magma chamber models provides composition-volume estimates of extracted magma that coincide with observed bimodal composition-volume relations. The strong variability in latent heat production is an important control, and its characterization is central to physical models of magma chamber evolution.

Nelson, B. K.; Ghiorso, M. S.; Bachmann, O.; Dufek, J.

2011-12-01

250

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

251

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

252

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

253

Endocytosis of Mycobacterium tuberculosis Heat Shock Protein 60 Is Required to Induce Interleukin-10 Production in Macrophages*  

PubMed Central

Understanding the signaling pathways involved in the regulation of anti-inflammatory and pro-inflammatory responses in tuberculosis is extremely important in tailoring a macrophage innate response to promote anti-tuberculosis immunity in the host. Although the role of toll-like receptors (TLRs) in the regulation of anti-inflammatory and pro-inflammatory responses is known, the detailed molecular mechanisms by which the Mycobacterium tuberculosis bacteria modulate these innate responses are not clearly understood. In this study, we demonstrate that M. tuberculosis heat shock protein 60 (Mtbhsp60, Cpn60.1, and Rv3417c) interacts with both TLR2 and TLR4 receptors, but its interaction with TLR2 leads to clathrin-dependent endocytosis resulting in an increased production of interleukin (IL)-10 and activated p38 MAPK. Blockage of TLR2-mediated endocytosis inhibited IL-10 production but induced production of tumor necrosis factor (TNF)-? and activated ERK1/2. In contrast, upon interaction with TLR4, Mtbhsp60 remained predominantly localized on the cell surface due to poorer endocytosis of the protein that led to decreased IL-10 production and p38 MAPK activation. The Escherichia coli homologue of hsp60 was found to be retained mainly on the macrophage surface upon interaction with either TLR2 or TLR4 that triggered predominantly a pro-inflammatory-type immune response. Our data suggest that cellular localization of Mtbhsp60 upon interaction with TLRs dictates the type of polarization in the innate immune responses in macrophages. This information is likely to help us in tailoring the host protective immune responses against M. tuberculosis. PMID:23846686

Parveen, Nazia; Varman, Raja; Nair, Shiny; Das, Gobardhan; Ghosh, Sudip; Mukhopadhyay, Sangita

2013-01-01

254

Propagation of Localization Optimal Entropy Production and Convergence rates for the Central Limit Theorem  

E-print Network

We prove for the rescaled convolution map $f\\to f\\circledast f$ propagation of polynomial, exponential and gaussian localization. The gaussian localization is then used to prove an optimal bound on the rate of entropy production by this map. As an application we prove the convergence of the CLT to be at the optimal rate $1/\\sqrt{n}$ in the entropy (and $L^1$) sense, for distributions with finite 4th moment.

E. Carlen; A. Soffer

2011-06-11

255

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

256

Local heat treatment of high strength steels with zoom-optics and 10kW-diode laser  

NASA Astrophysics Data System (ADS)

High strength steels enable new solutions for weight optimized car bodies without sacrificing crash safety. However, cold forming of these steels is limited due to the need of high press capacity, increased tool wear, and limitations in possible geometries. One can compensate for these drawbacks by local heat treatment of the blanks. In high-deformation areas the strength of the material is reduced and the plasticity is increased by diode laser irradiation. Local heat treatment with diode laser radiation could also yield key benefits for the applicability of press hardened parts. High strength is not desired all over the part. Joint areas or deformation zones for requested crash properties require locally reduced strength. In the research project "LOKWAB" funded by the German Federal Ministry of Education and Research (BMBF), heat treatment of high strength steels was investigated in cooperation with Audi, BMW, Daimler, ThyssenKrupp, Fraunhofer- ILT, -IWU and others. A diode laser with an output power of 10 kW was set up to achieve acceptable process speed. Furthermore a homogenizing zoom-optics was developed, providing a rectangular focus with homogeneous power density. The spot size in x- and y-direction can be changed independently during operation. With pyrometer controlled laser power the surface temperature is kept constant, thus the laser treated zone can be flexibly adapted to the needs. Deep-drawing experiments show significant improvement in formability. With this technique, parts can be manufactured, which can conventionally only be made of steel with lower strength. Locally reduced strength of press hardened serial parts was demonstrated.

Baumann, Markus; Krause, Volker; Bergweiler, Georg; Flaischerowitz, Martin; Banik, Janko

2012-03-01

257

Effect of Discrete Fracture Network Characteristics on the Sustainability of Heat Production in Enhanced Geothermal Reservoirs  

NASA Astrophysics Data System (ADS)

Viability of an enhanced or engineered geothermal reservoir is determined by the rate of produced fluid at production wells and the rate of temperature drawdown in the reservoir as well as that of the produced fluid. Meeting required targets demands sufficient permeability and flow circulation in a relatively large volume of rock mass. In-situ conditions such overall permeability of the bedrock formation, magnitude and orientation of stresses, and the characteristics of the existing Discrete Fracture Network (DFN) greatly affect sustainable heat production. Because much of the EGS resources are in formations with low permeability, different stimulation techniques are required prior to the production phase to enhance fluid circulation. Shear stimulation or hydro-shearing is the method of injecting a fluid into the reservoir with the aim of increasing the fluid pressure in the naturally fractured rock and inducing shear failure or slip events. This mechanism can enhance the system's permeability through permanent dilatational opening of the sheared fractures. Using a computational modeling approach, the correlation between heat production and DFN statistical characteristics, namely the fracture length distribution, fracture orientation, and also fracture density is studied in this paper. Numerical analyses were completed using two-dimensional distinct element code UDEC (Itasca, 2011), which represents rock masses as an assembly of interacting blocks separated by fractures. UDEC allows for simulation of fracture propagation along the predefined planes only (i.e., the trajectory of the hydraulic fracture is not part of the solution of the problem). Thus, the hydraulic fracture is assumed to be planar, aligned with the direction of the major principal stress. The pre-existing fractures were represented explicitly. They are discontinuities which deform elastically, but also can open and slip (Coulomb slip law) as a function of pressure and total stress changes. The fluid injection into the reservoir during stimulation phase was simulated using a fully coupled hydro-mechanical model. The heat production phase was simulated using a coupled thermo-hydro-mechanical model. In these simulations, both advective heat transfer by fluid flow and the conductive heat transfer within the rock blocks were modeled. The effect of temperature change on stresses and fracture aperture, and thus flow rates was considered. The response of formations with different DFN characteristics are analyzed by evaluating the production rate, produced power, and total energy extracted from the system over a period of five years. By simulating a full cycle of stimulation and production, the numerical modeling approach represents a realistic estimate of evolving permeability and evaluates how stimulation can be beneficial to the production phase. It is believed that these numerical sensitivity studies can provide valuable insight in evaluation of the potential of success of an EGS project, and can be used to better design the operational parameters in order to optimize heat production. Keywords: Numerical modeling, rock mechanics, discrete fracture network, stimulation, engineered geothermal reservoirs, heat production

Riahi, A.; Damjanac, B.

2013-12-01

258

Enhanced glycerol production in Shochu yeast by heat-shock treatment is due to prolonged transcription of GPD1.  

PubMed

Enhancement of glycerol production in Shochu yeast, which was induced by heat-shock treatment, was studied. Although heat-shock treatment (45 degrees C, 1 h) caused a transient delay in cell growth, the amount of glycerol produced by heat-shock-treated cells was 20% higher than that by control cells. During the glycerol-production phase, the NAD+-dependent glycerol-3-phosphate dehydrogenase (GPDH) activity of heat-shock-treated cells was much higher than that of control cells, suggesting that a higher GPDH activity enhances glycerol production. The level of NAD+-dependent glycerol dehydrogenase (GDH) activity was almost the same between heat-shock-treated cells and control cells. The results of Northern blot analysis of GPD genes (GPD1 and GPD2) encoding the GPDH enzyme showed that the transcription of GPD genes was not affected by heat-shock treatment but the period of intensive transcription of GPD1 was prolonged. PMID:16232830

Kajiwara, Y; Ogawa, K; Takashita, H; Omori, T

2000-01-01

259

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

260

Heat production rate from radioactive elements in igneous and metamorphic rocks in Eastern Desert, Egypt.  

PubMed

Radioactive heat-production data of Igneous and Metamorphic outcrops in the Eastern Desert are presented. Samples were analysed using a low level gamma-ray spectrometer (HPGe) in the laboratory. A total of 205 rock samples were investigated, covering all major rock types of the area. The heat-production rate of igneous rocks ranges from 0.11 (basalt) to 9.53 microWm(-3) (granite). In metamorphic rocks it varies from 0.28 (serpentinite ) to 0.91 microWm(-3) (metagabbro). The contribution due to U is about 51%, as that from Th is 31% and 18% from K. The corresponding values in igneous rocks are 76%, 19% and 5%, respectively. The calculated values showed good agreement with global values except in some areas containing granites. PMID:16120480

Abbady, Adel G E; El-Arabi, A M; Abbady, A

2006-01-01

261

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. PMID:16840557

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

2006-01-01

262

Enhancement of anaerobic biohydrogen/methane production from cellulose using heat-treated activated sludge.  

PubMed

Anaerobic digestion is an effective technology to convert cellulosic wastes to methane and hydrogen. Heat-treatment is a well known method to inhibit hydrogen-consuming bacteria in using anaerobic mixed cultures for seeding. This study aims to investigate the effects of heat-treatment temperature and time on activated sludge for fermentative hydrogen production from alpha-cellulose by response surface methodology. Hydrogen and methane production was evaluated based on the production rate and yield (the ability of converting cellulose into hydrogen and methane) with heat-treated sludge as the seed at various temperatures (60-97 degrees C) and times (20-60 min). Batch experiments were conducted at 55 degrees C and initial pH of 8.0. The results indicate that hydrogen and methane production yields peaked at 4.3 mmol H2/g cellulose and 11.6 mmol CH4/g cellulose using the seed activated sludge that was thermally treated at 60 degrees C for 40 min. These parameter values are higher than those of no-treatment seed (HY 3.6 mmol H2/g cellulose and MY 10.4 mmol CH4/g cellulose). The maximum hydrogen production rate of 26.0 mmol H2/L/d and methane production rate of 23.2 mmol CH4/L/d were obtained for the seed activated sludge that was thermally treated at 70 degrees C for 50 min and 60 degrees C for 40 min, respectively. PMID:21902022

Lay, C H; Chang, F Y; Chu, C Y; Chen, C C; Chi, Y C; Hsieh, T T; Huang, H H; Lin, C Y

2011-01-01

263

Application of Magnetic Circuit and Multiple-Coils Array in Induction Heating for Improving Localized Hyperthermia  

Microsoft Academic Search

? Abstract— Aiming the application of localized hyperthermia, a magnetic induction system with new approaches is proposed. The techniques in this system for improving the effectiveness of localized hyperthermia are that using magnetic circuit and the multiple-coil array instead of a giant coil for generating magnetic field. Specially, amorphous metal is adopted as the material of magnetic circuit. Detail design

Chi-Fang Huang; Xi-Zhang Lin; Yi-Ru Yang

2009-01-01

264

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

265

Technological Alternatives or Use of Wood Fuel in Combined Heat and Power Production  

NASA Astrophysics Data System (ADS)

Abstract Latvia aims for 40% share of renewable energy in the total final energy use. Latvia has large resources of biomass and developed district heating systems. Therefore, use of biomass for heat and power production is an economically attractive path for increase of the share of renewable energy. The optimum technological solution for use of biomass and required fuel resources have to be identified for energy planning and policy purposes. The aim of this study was to compare several wood fuel based energy conversion technologies from the technical and economical point of view. Three biomass conversion technologies for combined heat and electricity production (CHP) were analyzed: • CHP with steam turbine technology; • gasification CHP using gas engine; • bio-methane combined cycle CHP. Electricity prices for each alternative are presented. The results show the level of support needed for the analyzed renewable energy technologies and time period needed to reach price parity with the natural gas - fired combined cycle gas turbine (CCGT) CHPss. The results also show that bio-methane technology is most competitive when compared with CCGT among the considered technologies regarding fuel consumption and electricity production, but it is necessary to reduce investment costs to reach the electricity price parity with the natural gas CCGT.

Rusanova, Jekaterina; Markova, Darja; Bazbauers, Gatis; Valters, K?rlis

2013-12-01

266

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

267

Supramaximal heat production induced by aminophylline in temperature-acclimated rats  

NASA Astrophysics Data System (ADS)

Previous studies have shown that aminophylline, a phosphodiesterase inhibitor (thereby increasing intracellular cyclic AMP concentration) elicits supramaximal heat production and improves cold tolerance in rats acclimated to 22°C. To test whether aminophylline-stimulated supramaximal thermogenesis is independent of both the thermogenic capacity (i.e. aerobic fitness) and the mode of thermogenesis (shivering vs. non-shivering), rats (adult male Sprague-Dawley, approximately 400 g) of two different ages (4 11 month and 9 17 month, n=12 for each) were acclimated to 5, 15, and 25°C in succession and their thermogenic responses to aminophylline subsequently assessed. Aminophylline elicited supramaximal thermogenesis and improved cold tolerance regardless of age or acclimating temperatures. Further, the absolute net increase in heat production stimulated by aminophylline was also similar for all acclimating temperatures. After acclimating to 15°C, a single injection of aminophylline in the older rats elicited thermogenesis greater than that of the controls acclimated to 5°C; in the younger rats, aminophylline duplicated 46% of the increase in thermogenesis observed after acclimating to 5°C. These results indicated that the aminophylline-stimulated extra heat production is independent of both the thermogenic capacity and the mode of thermogenesis. It is possible that an enhanced substrate mobilization consequent to increased intracellular cyclic AMP concentration by aminophylline underlies the common mechanism via which supramaximal thermogenesis is elicited in temperature-acclimated rats.

Wang, L. C. H.

1985-03-01

268

Star-Product Functions in Higher-Spin Theory and Locality  

E-print Network

Properties of the functional classes of star-product elements associated with higher-spin gauge fields and gauge parameters are elaborated. Cohomological interpretation of the nonlinear higher-spin equations is given. An algebra ${\\mathcal H}$, where solutions of the nonlinear higher-spin equations are valued, is found. A conjecture on the classes of star-product functions underlying (non)local maps and gauge transformations in the nonlinear higher-spin theory is proposed.

Vasiliev, M A

2015-01-01

269

Star-Product Functions in Higher-Spin Theory and Locality  

E-print Network

Properties of the functional classes of star-product elements associated with higher-spin gauge fields and gauge parameters are elaborated. Cohomological interpretation of the nonlinear higher-spin equations is given. An algebra ${\\mathcal H}$, where solutions of the nonlinear higher-spin equations are valued, is found. A conjecture on the classes of star-product functions underlying (non)local maps and gauge transformations in the nonlinear higher-spin theory is proposed.

M. A. Vasiliev

2015-02-08

270

An evaluation of local thermal analysis of polymers on the sub-micrometer scale using heated scanning probe microscopy cantilevers.  

PubMed

A basic understanding of thermal properties of polymers is of fundamental importance for the development of advanced polymers. However, up to now, mainly bulk properties have been investigated. To characterize local softening processes in polymers, a local thermal analysis (LTA) technique is applied as an add-on to a scanning probe microscope. The development of a new generation of heatable cantilever probes enables thermal analysis in the sub-?m range. This method is based on an appropriate temperature calibration, which provides a reliable correlation of the applied voltage heating the tip and the actual temperature at the tip-sample interface. As the presented technique is more susceptible to environmental changes than comparable macroscopic methods, different parameters that might influence its performance are evaluated like a strong dependence on sample temperature. It is shown that the measured softening temperature on a polystyrene (PS) sample decreases from 102.2 to 66.4 °C as the temperature of the substrate is increased by 50 °C. The interaction between heat from the cantilever and the substrate is the reason for local sample softening, which opens new perspectives to understand the temperature calibration process using the melting standard method. A stepwise guideline for a suitable temperature calibration is provided. PMID:24654598

Fischinger, Thomas J; Laher, Martin; Hild, Sabine

2014-05-22

271

Vermont Biofuels Initiative: Local Production for Local Use to Supply a Portion of VermontâÂ?Â?s Energy Needs  

SciTech Connect

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

Scott Sawyer; Ellen Kahler

2009-05-31

272

Influence of local and external processes on the annual nitrogen cycle and primary productivity on Georges Bank: A 3-D  

E-print Network

Influence of local and external processes on the annual nitrogen cycle and primary productivity.V. All rights reserved. Keywords: Nitrogen cycle; Phytoplankton productivity; Modeling; Biological., Influence of local and external processes on the annual nitrogen cycle and primary productivity on Georges

Chen, Changsheng

273

Predictions of Heating Rates in Localized Magnetic Structures From The Photosphere To The Upper Chromosphere  

NASA Astrophysics Data System (ADS)

The heating rates due to resistive dissipation of magnetic field aligned currents and of Pedersen currents are computed as functions of height and horizontal radius in a specified 2.5 D magnetic field from the photosphere to the upper chromosphere. The model uses the VAL C height dependent profiles of temperature, and electron, proton, hydrogen, helium, and heavy ion densities together with the magnetic field to compute the anisotropic electrical conductivity tensor for each charged particle species. The magnetic field is parameterized by its maximum magnitude B0, scale height L, characteristic diameter D0, and twist ? which is the ratio of the azimuthal field component to the radial field component. The objective is to determine the ranges of values of these parameters that yield heating rates that are within observational constraints for values of D0 that are above and below the resolution limit of ˜ 150 km. This provides a test of the proposition that Pedersen current dissipation is a major source of chromopsheric heating in magnetic structures throughout the chromosphere, and that it is the rapid increase of charged particle magnetization with height in the lower chromosphere that causes the chromospheric temperature inversion and the rapid increase of the heating rate per unit mass with height in this region. It is found that the heating rate is a monotonically increasing function of B0, L, and ? , and a monotonically decreasing function of D0. For values of D0 below the resolution limit, values of ? >> 1 correspond to strongly heated magnetic structures. This work was supported by NSF grant ATM 9816335.

Goodman, M. L.

2003-05-01

274

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

275

Dietary fat affects heat production and other variables of equine performance, under hot and humid conditions.  

PubMed

Does dietary fat supplementation during conditioning improve athletic performance, especially in the heat? Fat adaptation has been used to increase energy density, decrease bowel bulk and faecal output and reduce health risks associated with hydrolysable carbohydrate overload. It may also reduce spontaneous activity and reactivity (excitability), increase fatty acid oxidation, reduce CO2 production and associated acidosis, enhance metabolic regulation of glycolysis, improve both aerobic and anaerobic performance and substantially reduce heat production. A thermochemical analysis of ATP generation showed the least heat release during the direct oxidation of long chain fatty acids, which have a 3% advantage over glucose and 20 to 30% over short chain fatty acids and amino acids. Indirect oxidation via storage as triglyceride increased heat loss during ATP generation by 3% for stearic acid, 65% for glucose and 174% for acetic acid. Meal feeding and nutrient storage, therefore, accentuates the advantage of dietary fat. A calorimetric model was based on initial estimates of net energy for competitive work (10.76 MJ for the Endurance Test of an Olympic level 3-day-event), other work (14.4 MJ/day) and maintenance (36 MJ), then applied estimates of efficiencies to derive associated heat productions for the utilisation of 3 diets, Diet A: hay (100), Diet B: hay and oats (50:50) and Diet C: hay, oats and vegetable oil (45:45:10), the difference between the last 2 diets representing fat adaptation. During a 90.5 min speed and stamina test, heat production was estimated as 37, 35.4 and 34.6 MJ for the 3 diets, respectively, an advantage 0.8 MJ less heat load for the fat adapted horse, which would reduce water needed for evaporation by 0.33 kg and reduce body temperature increase by about 0.07 degree C. Total estimated daily heat production was 105, 93 and 88 MJ for the 3 diets, respectively, suggesting a 5 MJ advantage for the fat adapted horse (Diet C vs. Diet B). Estimated intake energy was 348, 269 and 239 MJ for the 3 diets, respectively, and corresponding daily intakes as fed were 22.2, 16.6 and 12.9 kg, an advantage of 3.7 kg for the fat adapted horse. Water requirement was estimated to decrease by about 6 kg/day in the fat adapted horse: 4 kg less faecal water output and 2 kg less water for evaporation. This model indicated that the fat supplemented diet reduced daily heat load by 5%, feed intake by 22%, faecal output (and bowel ballast) by 31% and water requirement by 12%. The advantage of fat supplementation over hay and oats was in general about half that gained by hay and oats over hay alone. PMID:8894547

Kronfeld, D S

1996-07-01

276

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

277

Heat Wave Safety Checklist  

MedlinePLUS

... to 72 hours. Excessive Heat Warning—Heat Index values are forecast to meet or exceed locally defined ... highs=105-110° Fahrenheit). Heat Advisory—Heat Index values are forecast to meet locally defined advisory criteria ...

278

Appropriation of the Eclipse Ecosystem: Local Integration of Global Network Production  

E-print Network

Appropriation of the Eclipse Ecosystem: Local Integration of Global Network Production Gunnar source projects. Research on such software ecosystems shows that collaboration patterns in the software presents an empirical study on the practices of appropriating the Eclipse ecosystem as an example

279

Fully Distributed Scrum: Replicating Local Productivity and Quality with Offshore Teams  

Microsoft Academic Search

Scrum was designed for hyperproductive teams where productivity increases by 5-10 times over industry averages and many collocated teams have achieved this effect. The question for this paper is whether distributed, offshored teams can consistently achieve the same level of performance. In particular, can a team establish a localized velocity and quality and then maintain or increase that velocity and

Jeffrey Sutherland; Guido Schoonheim; Mauritz Rijk

2009-01-01

280

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

281

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

282

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

283

The effects of an excited impinging jet on the local heat transfer coefficient of aircraft turbine blades  

NASA Astrophysics Data System (ADS)

The primary objective of this paper is to present the results of research into the effects of periodic excitation upon the local heat transfer characteristics of a turbine blade cooled by an impinging jet of air. A curved plate (used to simulate the inner leading edge of a turbine blade) was subjected to a two-dimensional jet flow field (Re = 10,000) with a superimposed periodic acoustic disturbance. When compared to the naturally disturbed flow, the excited flow field was found to reduce the local Nusselt number and cool the blade less efficiently (by as much as ten percent in the extreme cases). The results of the study appear to indicate that harmonic disturbances present a serious controlling factor in the quest for optimization of turbine blade cooling techniques. By isolating dominant frequencies in gas turbine engines and working to suppress them, it is believed that significant contributions towards the desired increase in turbine inlet temperature could be possible.

Disimile, P. J.; Paule, D. M.

1988-06-01

284

Local heat transfer distribution in a two-pass trapezoidal channel with a 180{degree} turn via the transient liquid crystal technique  

SciTech Connect

This experimental investigation studies the heat transfer characteristics of cooling airflows in serpentine channels in stator blades of gas turbines. The internal cooling channels are modeled as a smooth two-pass channel of trapezoidal cross section. Attention is focused on the effect of the 180{degree} turn on the local heat transfer distributions on the interior surfaces of the various walls at the turn, under turbulent flow conditions. Transient heat transfer experiments, using encapsulated thermochromic liquid crystals, are conducted to obtain the local distributions of the heat transfer coefficient on all the walls at the turn for various rates of airflow through the channel, corresponding to Reynolds numbers between 30,000 and 88,000. The heat transfer is, in general, much higher on the walls in the turn and downstream of the turn than on the walls upstream of the turn. The turn induces secondary flows that impinge on the end wall and the outlet outer wall, causing high heat transfer in several distinct regions on the walls. The flow separates at the tip of the middle wall and reattaches on the outlet inner wall in a region only a short distance from the turn. The heat transfer is the lowest on the inlet outer wall. Heat transfer enhancement due to the turn is the highest in the lowest Reynolds number case. The trends of the local heat transfer distributions on the various walls at the turn are relatively insensitive to varying the flow rate, over the range of Reynolds number studied.

Endley, S.; Yoon, C.; Lau, S.C.

1999-07-01

285

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

286

Heat Conduction and Entropy Production in Anharmonic Crystals with Self-Consistent Stochastic Reservoirs  

E-print Network

We investigate a class of anharmonic crystals in $d$ dimensions, $d\\ge 1$, coupled to both external and internal heat baths of the Ornstein-Uhlenbeck type. The external heat baths, applied at the boundaries in the 1-direction, are at specified, unequal, temperatures $\\tlb$ and $\\trb$. The temperatures of the internal baths are determined in a self-consistent way by the requirement that there be no net energy exchange with the system in the non-equilibrium stationary state (NESS). We prove the existence of such a stationary self-consistent profile of temperatures for a finite system and show it minimizes the entropy production to leading order in $(\\tlb -\\trb)$. In the NESS the heat conductivity $\\kappa$ is defined as the heat flux per unit area divided by the length of the system and $(\\tlb -\\trb)$. In the limit when the temperatures of the external reservoirs goes to the same temperature $T$, $\\kappa(T)$ is given by the Green-Kubo formula, evaluated in an equilibrium system coupled to reservoirs all having the temperature $T$. This $\\kappa(T)$ remains bounded as the size of the system goes to infinity. We also show that the corresponding infinite system Green-Kubo formula yields a finite result. Stronger results are obtained under the assumption that the self-consistent profile remains bounded.

Federico Bonetto; Joel L. Lebowitz; Jani Lukkarinen; Stefano Olla

2008-11-21

287

Volatile production during preignition coal heating. Quarterly progress report, April 1981 - June 1981  

SciTech Connect

The goal of this program is to determine the characteristic pyrolysis behavior of representative coals under laser heating. The use of a CO/sub 2/ laser enables a controllable heating rate to be given to the coal particles as they pass through the laser beam. The development of such a laser heating diagnostic should prove to be an extremely valuable tool for generation of a data base necessary for the future design of coal burning facilities. The experimental configuration is illustrated. A dilute coal/gas stream, surrounded aby an inert shield flow is passed through a laser beam from an Avco HPL CO/sub 2/ laser. Under a prescribed flux density, and thus heating rate, the particle pyrolyse. The gaseous products are sampled and subsequently analyzed (primarily by gas chromatography) for carbon conversion. Particle temperature is to be monitored by a two-color pyrometer and particle velocity by laser Doppler velocimeter, by which means, evolution of the pyrolysis process can be determined.

Not Available

1981-07-01

288

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

289

Gas production and transport during bench-scale electrical resistance heating of water and trichloroethene  

NASA Astrophysics Data System (ADS)

The effective remediation of chlorinated solvent source zones using in situ thermal treatment requires successful capture of gas that is produced. Replicate electrical resistance heating experiments were performed in a thin bench-scale apparatus, where water was boiled and pooled dense non-aqueous phase liquid (DNAPL) trichloroethene (TCE) and water were co-boiled in unconsolidated silica sand. Quantitative light transmission visualization was used to assess gas production and transport mechanisms. In the water boiling experiments, nucleation, growth and coalescence of the gas phase into connected channels were observed at critical gas saturations of Sgc = 0.233 ± 0.017, which allowed for continuous gas transport out of the sand. In experiments containing a colder region above a target heated zone, condensation prevented the formation of steam channels and discrete gas clusters that mobilized into colder regions were trapped soon after discontinuous transport began. In the TCE-water experiments, co-boiling at immiscible fluid interfaces resulted in discontinuous gas transport above the DNAPL pool. Redistribution of DNAPL was also observed above the pool and at the edge of the vapor front that propagated upwards through colder regions. These results suggest that the subsurface should be heated to water boiling temperatures to facilitate gas transport from specific locations of DNAPL to extraction points and reduce the potential for DNAPL redistribution. Decreases in electric current were observed at the onset of gas phase production, which suggests that coupled electrical current and temperature measurements may provide a reliable metric to assess gas phase development.

Hegele, P. R.; Mumford, K. G.

2014-09-01

290

Heat production and fluorescence changes of toad sartorius muscle during aerobic recovery after a short tetanus.  

PubMed

1. The time course of the aerobic recovery following a 0.5 sec tetanus at 20 degrees C of the sartorius muscle of the toad Bufo bufo, equilibrated in bicarbonate-CO(2) Ringer solution, has been followed by recording simultaneously the heat production and the fluorescence excited by ultra-violet light at 366 nm.2. The fluorescence light emitted in these conditions in the region of 450 nm monitors the state of oxidation-reduction of the nicotinamideadenine dinucleotides (NAD(+)-NADH). After a short tetanus, the cycle evoked consists of an initial increase of the fluorescence (reduction of NAD(+)) followed by a long lasting phase of decreased light emission. This includes an early period of oxidation of NADH succeeded by a slow reduction of the NAD(+) formed in excess over the resting state. After iodoacetate, the initial reduction is suppressed.3. The time course of both fluorescence and heat production may be analysed into a rapid and a slow component by a double exponential model.4. The time courses of the aerobic recovery heat and of the fluorescence changes are similar after five minutes, but differ in their fast components. IAA significantly increases the rate constants of the fast terms of both monitors.5. The slow component is mainly related to aerobic processes while the fast one is due to both oxidative and glycolytic reactions occurring simultaneously. PMID:4339903

Godfraind-de Becker, A

1972-06-01

291

Determination of local anesthetics in illegal products using HPLC method with amperometric detection.  

PubMed

An HPLC method with amperometric detection was developed for analysis of two local anesthetics (lidocaine and benzocaine) in products for delaying ejaculation illegally marketed in Polish sex shops. Chromatographic elution on an RP column C18 with mobile phase composed of acetate buffer with acetonitrile, provides an optimal separation not only of active substances but also electroactive preservatives which are occasionally added to cosmetic creams (methylparaben and propylparaben). Application of glassy carbon electrode as a working electrode and a procedure with pulsed potential waveforms enables a sensitive, accurate measurement within a relatively short analysis time (250 s). This method has been successfully employed for the determination of local anesthetics in products under investigation. The obtained results show that most samples contained therapeutic concentrations of lidocaine or benzocaine. According to European law, a sale of products containing lidocaine or benzocaine outside the pharmacy sector is forbidden. PMID:22594253

Jadach, Magdalena; B?azewicz, Agata; Fijalek, Zbigniew

2012-01-01

292

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

293

Calorimetric Determinations of the Heat and Products of Detonation for Explosives: October 1961 to April 1982  

NASA Astrophysics Data System (ADS)

This report is a compilation of heat-of-detonation and product-composition data obtained at Lawrence Livermore National Laboratory during the last 21 years. In each determination, a 25-g high-explosive charge was detonated in a bomb calorimeter; a complete calorimetric measurement was made in 1 to 2 h with a precision of 0.3%. Data were interpreted using thermodynamic and hydrodynamic computer calculations. For unconfined or lightly confined charges, the released energy is largely retained in the products, which are subsequently shocked considerably off the Chapman-Jouguet isentrope by reflections from the bomb wall. For heavily confined charges, the detonation energy is largely converted to kinetic and internal energy of the confining case, and the products expand with minimal reshock along the Chapman-Jouguet isentrope.

Ornellas, D. L.

1982-04-01

294

Obtaining Reliable Information on Energy-Saving Regimes for the Heating of Continuous-Cast Semifinished Products Prior to Rolling  

Microsoft Academic Search

Reducing the amount of fuel used to heat continuous-cast semifinished products before rolling is an important problem in modern\\u000a high-speed rolling operations. The heating furnaces of high-speed rolling mills are usually operating under nonsteady conditions,\\u000a which makes it difficult to realize energy-saving regimes for heating the metal. Modern continuous furnaces are multi-zone\\u000a units, and the prescribed temperature regime in each

S. M. Andreev; B. N. Parsunkin; D. Yu. Zhadinskii

2005-01-01

295

Anaerobic Heat Production of Bull Spermatozoa. II. The Effects of Changes in the Colligative and Other Properties of the Suspending Medium  

Microsoft Academic Search

1. The anaerobic heat production of bull spermatozoa has been examined under varying environmental conditions, in an isothermal calorimeter, capacity 2.4 ml., working at atmospheric pressure. The minimum detectable heat production was 10 mu cal\\/min. The calorimeter was calibrated with needles containing plutonium oxide of known heat production, both now and in the future. 2. Abnormal environmental conditions or treatments,

Lord Rothschild

1959-01-01

296

Comparison of the effects of millimeter wave irradiation, general bath heating, and localized heating on neuronal activity in the leech ganglion  

NASA Astrophysics Data System (ADS)

The use of electrically-induced neuromodulation has grown in importance in the treatment of multiple neurological disorders such as Parkinson's disease, dystonia, epilepsy, chronic pain, cluster headaches and others. While electrical current can be applied locally, it requires placing stimulation electrodes in direct contact with the neural tissue. Our goal is to develop a method for localized application of electromagnetic energy to the brain without direct tissue contact. Toward this goal, we are experimenting with the wireless transmission of millimeter wave (MMW) energy in the 10-100 GHz frequency range, where penetration and focusing can be traded off to provide non-contact irradiation of the cerebral cortex. Initial experiments have been conducted on freshly-isolated leech ganglia to evaluate the real-time changes in the activity of individual neurons upon exposure to the MMW radiation. The initial results indicate that low-intensity MMWs can partially suppress the neuronal activity. This is in contrast to general bath heating, which had an excitatory effect on the neuronal activity. Further studies are underway to determine the changes in the state of the membrane channels that might be responsible for the observed neuromodulatory effects.

Romanenko, Sergii; Siegel, Peter H.; Wagenaar, Daniel A.; Pikov, Victor

2013-02-01

297

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

298

Free-radical production triggered by hyperthermia contributes to heat stress-induced cardioprotection in isolated rat hearts  

E-print Network

1 Free-radical production triggered by hyperthermia contributes to heat stress to either hyperthermia (42°C internal temperature for 15 min) or sham anaesthesia and treated or not with N hyperthermia appears to play a role in the heat stress induced cardioprotection, independently of Hsp levels

Paris-Sud XI, Université de

299

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. PMID:23795228

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

300

Heat and mass transfer coefficients during the refrigeration, freezing and storage of meats, meat products and analogues  

Microsoft Academic Search

The existing bibliographical data on heat and mass transfer coefficients during refrigeration, freezing and storage of meat and meat products were reviewed.Heat transfer coefficients for meat balls and hamburgers were determined experimentally in a prototype belt freezer. Measurements were carried out at different air velocities and directions of air flow. In each case, the coefficients thus obtained were correlated with

A. M. Tocci; R. H. Mascheroni

1995-01-01

301

Crustal radiogenic heat production and the selective survival of ancient continental crust  

NASA Technical Reports Server (NTRS)

It is pointed out that the oldest terrestrial rocks have so far revealed no evidence of the impact phase of earth evolution. This observation suggests that processes other than impact were dominant at the time of stabilization of these units. However, a use of the oldest terrestrial rocks as a sample of the early terrestrial crust makes it necessary to consider the possibility that these rocks may represent a biased sample. In the present study, the global continental heat flow data set is used to provide further evidence that potassium, uranium, and thorium abundances are, on the average, low in surviving Archean crust relative to younger continental crust. An investigation is conducted of the implications of relatively low crustal radiogenic heat production to the stabilization of early continental crust, and possible Archean crustal stabilization models are discussed.

Morgan, P.

1985-01-01

302

Crustal radiogenic heat production and the selective survival of ancient continental crust  

NASA Technical Reports Server (NTRS)

It is pointed out that the oldest terrestrial rocks have so far revealed no evidence of the impact phase of Earth evolution. This observation suggests that processes other than impact were dominant at the time of stabilization of these units. However, a use of the oldest terrestrial rocks as a sample of the early terrestrial crust makes it necessary to consider the possibility that these rocks may represent a biased sample. In the present study, the global continental heat flow data set is used to provide further evidence that potassium, uranium, and thorium abundances are, on the average, low in surviving Archean crust relative to younger continental crust. An investigation is conducted of the implications of relatively low crustal radiogenic heat production to the stabilization of early continental crust, and possible Archean crustal stabilization models are discussed.

Morgan, P.

1985-01-01

303

Effect of Catalytic Pyrolysis Conditions Using Pulse Current Heating Method on Pyrolysis Products of Wood Biomass  

PubMed Central

The influence of catalysts on the compositions of char and pyrolysis oil obtained by pyrolysis of wood biomass with pulse current heating was studied. The effects of catalysts on product compositions were analyzed using GC-MS and TEM. The compositions of some aromatic compounds changed noticeably when using a metal oxide species as the catalyst. The coexistence or dissolution of amorphous carbon and iron oxide was observed in char pyrolyzed at 800°C with Fe3O4. Pyrolysis oil compositions changed remarkably when formed in the presence of a catalyst compared to that obtained from the uncatalyzed pyrolysis of wood meal. We observed a tendency toward an increase in the ratio of polyaromatic hydrocarbons in the pyrolysis oil composition after catalytic pyrolysis at 800°C. Pyrolysis of biomass using pulse current heating and an adequate amount of catalyst is expected to yield a higher content of specific polyaromatic compounds. PMID:25614894

Honma, Sensho; Hata, Toshimitsu; Watanabe, Takashi

2014-01-01

304

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.

305

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

306

Analytical calculation of the skin temperature distribution due to subcutaneous heat production in a spherical heat source.  

PubMed

An analytical solution of the thermal conductivity equation describing the surface temperature distribution over a buried heat source is given in tabular form. The solution is applicable to experimental models for studies of the surface temperature over an implanted artificial heat source. The results can also be used for the analysis of the skin temperature over biological heat sources such as breat tumours. PMID:1153512

Gustafsson, S E; Nilsson, S K; Torell, L M

1975-03-01

307

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

308

A Randomized Controlled Trial of Local Heat Therapy Versus Intravenous Sodium Stibogluconate for the Treatment of Cutaneous Leishmania major Infection  

PubMed Central

Background Cutaneous Leishmania major has affected many travelers including military personnel in Iraq and Afghanistan. Optimal treatment for this localized infection has not been defined, but interestingly the parasite is thermosensitive. Methodology/Principal Findings Participants with parasitologically confirmed L. major infection were randomized to receive intravenous sodium stibogluconate (SSG) 20mg/kg/day for ten doses or localized ThermoMed (TM) device heat treatment (applied at 50°C for 30 seconds) in one session. Those with facial lesions, infection with other species of Leishmania, or more than 20 lesions were excluded. Primary outcome was complete re-epithelialization or visual healing at two months without relapse over 12 months. Fifty-four/56 enrolled participants received intervention, 27 SSG and 27 TM. In an intent to treat analysis the per subject efficacy at two months with 12 months follow-up was 54% SSG and 48% TM (p?=?0.78), and the per lesion efficacy was 59% SSG and 73% TM (p?=?0.053). Reversible abdominal pain/pancreatitis, arthralgias, myalgias, headache, fatigue, mild cytopenias, and elevated transaminases were more commonly present in the SSG treated participants, whereas blistering, oozing, and erythema were more common in the TM arm. Conclusions/Significance Skin lesions due to L. major treated with heat delivered by the ThermoMed device healed at a similar rate and with less associated systemic toxicity than lesions treated with intravenous SSG. Clinical Trial Registration ClinicalTrials.gov NCT 00884377 PMID:20231896

Aronson, Naomi E.; Wortmann, Glenn W.; Byrne, William R.; Howard, Robin S.; Bernstein, Wendy B.; Marovich, Mary A.; Polhemus, Mark E.; Yoon, In-Kyu; Hummer, Kelly A.; Gasser, Robert A.; Oster, Charles N.; Benson, Paul M.

2010-01-01

309

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. PMID:22542100

Lindeman, Robin Emily; Pelegri, Francisco

2012-01-01

310

In situ localization of heat-shock and histone proteins in honey-bee ( apis mellifera l.) larvae infected with paenibacillus larvae  

Microsoft Academic Search

The immunohistochemical localization of the heat shock proteins (Hsp70 and Hsp90) and histone protein in healthy and Paenibacillus larvae infected honeybee (Apis mellifera L.) larvae has been studied. Hsp70 was found in the nuclei and the cytoplasm of infected midgut, salivary gland cells and haemocytes, but not in uninfected larvae. Hsp90 was localized in both infected and uninfected cells. Exposed

Aleš Gregorc; Ivor D. Bowen

1999-01-01

311

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

312

Optimization of a One-Step Heat-Inducible In Vivo Mini DNA Vector Production System  

PubMed Central

While safer than their viral counterparts, conventional circular covalently closed (CCC) plasmid DNA vectors offer a limited safety profile. They often result in the transfer of unwanted prokaryotic sequences, antibiotic resistance genes, and bacterial origins of replication that may lead to unwanted immunostimulatory responses. Furthermore, such vectors may impart the potential for chromosomal integration, thus potentiating oncogenesis. Linear covalently closed (LCC), bacterial sequence free DNA vectors have shown promising clinical improvements in vitro and in vivo. However, the generation of such minivectors has been limited by in vitro enzymatic reactions hindering their downstream application in clinical trials. We previously characterized an in vivo temperature-inducible expression system, governed by the phage ? pL promoter and regulated by the thermolabile ? CI[Ts]857 repressor to produce recombinant protelomerase enzymes in E. coli. In this expression system, induction of recombinant protelomerase was achieved by increasing culture temperature above the 37°C threshold temperature. Overexpression of protelomerase led to enzymatic reactions, acting on genetically engineered multi-target sites called “Super Sequences” that serve to convert conventional CCC plasmid DNA into LCC DNA minivectors. Temperature up-shift, however, can result in intracellular stress responses and may alter plasmid replication rates; both of which may be detrimental to LCC minivector production. We sought to optimize our one-step in vivo DNA minivector production system under various induction schedules in combination with genetic modifications influencing plasmid replication, processing rates, and cellular heat stress responses. We assessed different culture growth techniques, growth media compositions, heat induction scheduling and temperature, induction duration, post-induction temperature, and E. coli genetic background to improve the productivity and scalability of our system, achieving an overall LCC DNA minivector production efficiency of ?90%.We optimized a robust technology conferring rapid, scalable, one-step in vivo production of LCC DNA minivectors with potential application to gene transfer-mediated therapeutics. PMID:24586704

Wettig, Shawn; Slavcev, Roderick A.

2014-01-01

313

Optimization of a one-step heat-inducible in vivo mini DNA vector production system.  

PubMed

While safer than their viral counterparts, conventional circular covalently closed (CCC) plasmid DNA vectors offer a limited safety profile. They often result in the transfer of unwanted prokaryotic sequences, antibiotic resistance genes, and bacterial origins of replication that may lead to unwanted immunostimulatory responses. Furthermore, such vectors may impart the potential for chromosomal integration, thus potentiating oncogenesis. Linear covalently closed (LCC), bacterial sequence free DNA vectors have shown promising clinical improvements in vitro and in vivo. However, the generation of such minivectors has been limited by in vitro enzymatic reactions hindering their downstream application in clinical trials. We previously characterized an in vivo temperature-inducible expression system, governed by the phage ? pL promoter and regulated by the thermolabile ? CI[Ts]857 repressor to produce recombinant protelomerase enzymes in E. coli. In this expression system, induction of recombinant protelomerase was achieved by increasing culture temperature above the 37°C threshold temperature. Overexpression of protelomerase led to enzymatic reactions, acting on genetically engineered multi-target sites called "Super Sequences" that serve to convert conventional CCC plasmid DNA into LCC DNA minivectors. Temperature up-shift, however, can result in intracellular stress responses and may alter plasmid replication rates; both of which may be detrimental to LCC minivector production. We sought to optimize our one-step in vivo DNA minivector production system under various induction schedules in combination with genetic modifications influencing plasmid replication, processing rates, and cellular heat stress responses. We assessed different culture growth techniques, growth media compositions, heat induction scheduling and temperature, induction duration, post-induction temperature, and E. coli genetic background to improve the productivity and scalability of our system, achieving an overall LCC DNA minivector production efficiency of ? 90%.We optimized a robust technology conferring rapid, scalable, one-step in vivo production of LCC DNA minivectors with potential application to gene transfer-mediated therapeutics. PMID:24586704

Nafissi, Nafiseh; Sum, Chi Hong; Wettig, Shawn; Slavcev, Roderick A

2014-01-01

314

Practical considerations for maximizing heat production in a novel thermobrachytherapy seed prototype  

SciTech Connect

Purpose: A combination of hyperthermia and radiation in the treatment of cancer has been proven to provide better tumor control than radiation administered as a monomodality, without an increase in complications or serious toxicities. Moreover, concurrent administration of hyperthermia and radiation displays synergistic enhancement, resulting in greater tumor cell killing than hyperthermia and radiation delivered separately. The authors have designed a new thermobrachytherapy (TB) seed, which serves as a source of both radiation and heat for concurrent brachytherapy and hyperthermia treatments when implanted in solid tumors. This innovative seed, similar in size and geometry to conventional seeds, will have self-regulating thermal properties. Methods: The new seed's geometry is based on the standard BEST Model 2301{sup 125}I seed, resulting in very similar dosimetric properties. The TB seed generates heat when placed in an oscillating magnetic field via induction heating of a ferromagnetic Ni–Cu alloy core that replaces the tungsten radiographic marker of the standard Model 2301. The alloy composition is selected to undergo a Curie transition near 50?°C, drastically decreasing power production at higher temperatures and providing for temperature self-regulation. Here, the authors present experimental studies of the magnetic properties of Ni–Cu alloy material, the visibility of TB seeds in radiographic imaging, and the ability of seed prototypes to uniformly heat tissue to a desirable temperature. Moreover, analyses are presented of magnetic shielding and thermal expansion of the TB seed, as well as matching of radiation dose to temperature distributions for a short interseed distance in a given treatment volume. Results: Annealing the Ni–Cu alloy has a significant effect on its magnetization properties, increasing the sharpness of the Curie transition. The TB seed preserves the radiographic properties of the BEST 2301 seed in both plain x rays and CT images, and a preliminary experiment demonstrates thermal self-regulation and adequate heating of a tissue-mimicking phantom by seed prototypes. The effect of self-shielding of the seed against the external magnetic field is small, and only minor thermal stress is induced in heating of the seeds from room temperature to well above the seed operating temperature. With proper selection of magnetic field parameters, the thermal dose distribution of an arrangement of TB and hyperthermia-only seeds may be made to match with its radiation dose distribution. Conclusions: The presented analyses address several practical considerations for manufacturing of the proposed TB seeds and identify critical issues for the prototype implementation. The authors’ preliminary experiments demonstrate close agreement with the modeling results, confirming the feasibility of combining sources of heat and radiation into a single thermobrachytherapy seed.

Gautam, Bhoj; Warrell, Gregory; Shvydka, Diana; Ishmael Parsai, E., E-mail: e.parsai@utoledo.edu [University of Toledo Medical Center, 3000 Arlington Avenue, MS1151, Toledo, Ohio 43614 (United States); Subramanian, Manny [BEST Medical International, Inc., 7643 Fullerton Road, Springfield, Virginia 22153 (United States)] [BEST Medical International, Inc., 7643 Fullerton Road, Springfield, Virginia 22153 (United States)

2014-02-15

315

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

316

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

317

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

318

Genome-wide analysis of the Populus Hsp90 gene family reveals differential expression patterns, localization, and heat stress responses  

PubMed Central

Background Members of the heat shock protein 90 (Hsp90) class of proteins are evolutionarily conserved molecular chaperones. They are involved in protein folding, assembly, stabilization, activation, and degradation in many normal cellular processes and under stress conditions. Unlike many other well-characterized molecular chaperones, Hsp90s play key roles in signal transduction, cell-cycle control, genomic silencing, and protein trafficking. However, no systematic analysis of genome organization, gene structure, and expression compendium has been performed in the Populus model tree genus to date. Results We performed a comprehensive analysis of the Populus Hsp90 gene family and identified 10 Populus Hsp90 genes, which were phylogenetically clustered into two major groups. Gene structure and motif composition are relatively conserved in each group. In Populus trichocarpa, we identified three paralogous pairs, among which the PtHsp90-5a/PtHsp90-5b paralogous pair might be created by duplication of a genome segment. Subcellular localization analysis shows that PtHsp90 members are localized in different subcellular compartments. PtHsp90-3 is localized both in the nucleus and in the cytoplasm, PtHsp90-5a and PtHsp90-5b are in chloroplasts, and PtHsp90-7 is in the endoplasmic reticulum (ER). Furthermore, microarray and semi-quantitative real-time RT-PCR analyses show that a number of Populus Hsp90 genes are differentially expressed upon exposure to various stresses. Conclusions The gene structure and motif composition of PtHsp90s are highly conserved among group members, suggesting that members of the same group may also have conserved functions. Microarray and RT-PCR analyses show that most PtHsp90s were induced by various stresses, including heat stress. Collectively, these observations lay the foundation for future efforts to unravel the biological roles of PtHsp90 genes. PMID:23915275

2013-01-01

319

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

320

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

NASA Astrophysics Data System (ADS)

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

321

A thermo-pharmacokinetic model of tissue temperature oscillations during localized heating.  

PubMed

Thermally-induced large blood flow increases and oscillations have been experimentally observed in both muscle and prostate tissues. However, the bio-physical/-chemical mechanisms underlying these phenomena remain undiscovered. To study the basic nature of these coupled thermal-mass transport processes, this study combines a compartmental vasodilator pharmacokinetics model with a bio-heat-transfer temperature model. The resulting simulated temperature responses to different applied power levels closely match both the overall behaviour and the fine structure of the complex temperature responses observed in vivo. This suggests that the coupled thermo-pharmacokinetic model captures the essence of the links between tissue temperature and blood flow oscillations and of the role of the important vaso-active substances. Thus, it appears that such thermo-pharmacokinetic models can provide a basis for helping to understand and quantify the fundamental bio-physical/-chemical processes that couple the transient tissue temperature distributions to blood flow oscillations. Such combined models allow investigators to directly predict tissue blood flow responses to applied power and avoid the need to make ad hoc assumptions regulating the blood flow rates present in heated tissues. PMID:15764354

Chen, C; Roemer, R B

2005-03-01

322

FEM simulation of local heating and melting during electrical discharge plasma impact  

NASA Astrophysics Data System (ADS)

The effect of an electrical discharge can be seen as an energy input into a material. This energy increases the material temperature within concentrated zones even over the boiling point producing the erosion of the material surface. In this paper, thermal analysis by a finite element method (FEM) and by using the analytical solution for the heat conduction problem in a semi-infinite solid subjected to a point source heat was carried out. The simulation includes the solid-liquid and liquid-vapour transformations, which facilitate the calculation of the volumes of the molten and vaporized materials. The simulation results were compared with the material loss due to individual sparks in several metallic electrodes at high pressure and room temperature. It was found that the volume of the molten pool is related to the volume of the eroded material, and therefore the material loss is practically controlled by the melting enthalpy and the melting point. Because of the linear relation between the eroded and molten pool volumes, it is possible to estimate the resistance to electrode erosion by calculating and comparing the volume of the molten pool with a reference metal.

Lasagni, A.; Soldera, F.; Mücklich, F.

2004-09-01

323

Strangeness Production and Local Thermalization in an Integrated Boltzmann + Hydrodynamics Approach  

NASA Astrophysics Data System (ADS)

We present results on strangeness production from a coupled Boltzmann and hydrodynamics approach to relativistic heavy ion reactions. This approach is based on the Ultra-relativistic Quantum Molecular Dynamics (UrQMD) transport model with an intermediate hydrodynamical evolution for the hot and dense stage of the collision. Final particle yields are discussed, putting special attention on the production of multistrange hyperons. We find that the yields for (multi)strange particles are strongly enhanced, due to the inferred local thermal equilibrium in the hydrodynamic evolution, leading to an improved description of experimental yields for these particles.

Steinheimer, J.; Petersen, H.; Burau, G.; Bleicher, M.; Stoecker, H.

2009-04-01

324

Survival of Helicobacter pylori in Turkish fermented sucuk and heat-treated sucuk during production.  

PubMed

The aim of this study was to investigate the survival of Helicobacter pylori during production of sucuk (Turkish fermented sausage). The sucuk mixture was inoculated with H. pylori ATCC 43504 to produce a final level in the mixture of ?5 × 10(6) CFU/g. Samples in group I were fermented and dried traditionally at 22°C for 7 days. Samples in groups II and III were subjected to the traditional fermentation at 22°C for 3 days. After fermentation, group II samples were fermented and dried at 35°C for 4 days and group III samples were treated with heat until the core temperature reached 65°C. On the first day of fermentation, a 1-log reduction in H. pylori was found in all groups. The H. pylori levels in all groups increased by about 1 log CFU/g by the third day of fermentation and reached the inoculation level. On the fifth and seventh days of fermentation, no appreciable change occurred in the level of H. pylori in groups I and II. After heat treatment, the H. pylori levels were below the level of detection. These results suggest that H. pylori can grow during sucuk fermentation and that a heat treatment should be used during sucuk processing to destroy H. pylori. PMID:22186045

Guner, Ahmet; Kav, Kursat; Tekinsen, Kemal Kaan; Dogruer, Yusuf; Telli, Nihat

2011-12-01

325

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

326

Local limit theorem for nonuniformly partially hyperbolic skew-products, and Farey sequences  

Microsoft Academic Search

We study skew-products of the form (x,\\\\omega)\\\\mapsto (Tx, \\\\omega+\\\\phi(x)) where T is a nonuniformly expanding map on a space X, preserving a (possibly singular) probability measure \\\\tilde\\\\mu, and \\\\phi:X\\\\to S^1 is a C^1 function. Under mild assumptions on \\\\tilde\\\\mu and \\\\phi, we prove that such a map is exponentially mixing, and satisfies the central and local limit theorems. These results

Sebastien Gouezel

2007-01-01

327

EFFECTS OF LOCALIZED AQUIFER BOILING ON FLUID PRODUCTION AT CERRO PRIETO.  

USGS Publications Warehouse

Localized aquifer boiling in the shallow two-phase reservoir of Cerro Prieto has produced excess steam and increased electrical output. Unfortunately it has also caused near-well mineral deposition that has decreased permeability and fluid flow. Inflow of cold water has limited the extent of aquifer boiling and permeability loss. The deeper reservoir at Cerro Prieto may need injection of cold water to decrease boiling and prevent loss of production. Refs.

Truesdell, Alfred H.; D'Amore, Franco; Nieva, David

1984-01-01

328

Distributing resources and collecting benefits: Integrating local planning, production costing, and central resource evaluation  

SciTech Connect

Distributed resources (DR) include small, modular generation and storage options, and demand-side management (SDM) that can be dispersed throughout a utility system. High-value DR applications are identified by comparing DR costs to avoided distribution investments and central generation expenses. One approach to making this comparison is to coordinate load flow and production costing simulations with bulk and local planning area models (BPMs and LPAMs). Such coordination is desirable because it accommodates existing models, but it poses two challenges. First, the long run marginal cost of power is not generally a simple sum of capacity costs and short-run marginal fuel costs. Second, interactions between bulk and distributed resources require iteration between the BPM and DR models; a simple iterative process, however, may not converge and could fail to yield a least-cost solution. These difficulties can be overcome by coordinating models with a decomposition scheme--such as Benders decomposition--that guarantees convergence and correct marginal costs. This paper outlines a decomposition approach that optimally coordinates BPMs, LPAMs, and production costing models for distributed resource evaluation. The coordination involves exchange among the models of information on investments, net power demands by local areas, and marginal costs in each iteration. The coordination scheme is illustrated by an example that uses a multiarea probabilistic production costing model with DC-load flow constraints and a mixed integer programming local area planning and production costing model. The results demonstrate the potential effect of resource costs, local area demands, and spatially-varying marginal bulk power costs on the value of DRs.

McCusker, S.A.; Hobbs, B.F.; Ji, Y.

1998-07-01

329

The product of hedgehog autoproteolytic cleavage active in local and long-range signalling  

Microsoft Academic Search

THE secreted protein products of the hedgehog (hh) gene family are associated with local and long-range signalling activities that are responsible for developmental patterning in multiple systems, including Drosophila embryonic and larval tissues1-8 and vertebrate neural tube, limbs and somites9-15. In a process that is critical for full biological activity, the hedgehog protein (Hh) undergoes autoproteolysis to generate two biochemically

Jeffery A. Porter; Doris P. von Kessler; Stephen C. Ekker; Keith E. Young; John J. Lee; Kevin Moses; Philip A. Beachy

1995-01-01

330

Model predictive control of a combined heat and power plant using local linear models  

SciTech Connect

Model predictive control has been applied to control of a combined heat and power plant. One of the main features of this plant is that it exhibits nonlinear process behavior due to large throughput swings. In this application, the operating window of the plant has been divided into a number of smaller windows in which the nonlinear process behavior has been approximated by linear behavior. For each operating window, linear step weight models were developed from a detailed nonlinear first principles model, and the model prediction is calculated based on interpolation between these linear models. The model output at each operating point can then be calculated from four basic linear models, and the required control action can subsequently be calculated with the standard model predictive control approach using quadratic programming.

Kikstra, J.F. [Delft Univ. of Technology (Netherlands). Faculty of Mechanical Engineering; Roffel, B. [Univ. of Twente, AE Enschede (Netherlands). Faculty of Chemical Engineering; Schoen, P. [Stork Engineers and Contractors, Amsterdam (Netherlands)

1998-10-01

331

Productivity and energy partition of late lactation dairy cows during heat exposure.  

PubMed

Three late-lactation Holstein cows were used to determine the effects of environmental temperature on performance and energy partitioning. Each cow was housed in a respiratory chamber for 30 consecutive days and exposed to three different conditions of environmental temperature: (i) 20 degrees C and 20 degrees C (20 degrees C), (ii) 25 degrees C and 20 degrees C (25 degrees C), (iii) 30 degrees C and 25 degrees C (30 degrees C) during the day and night, respectively. The temperature was switched in an interval of 10 days. Humidity in the chamber was maintained at 55-65% through the entire experimental period. The daily mean as well as morning and evening rectal temperatures of Holstein cows increased linearly (P < 0.05) as chamber temperature increased. There was a significant linear reduction in dry matter (DM) intake (P < 0.05) and an increase in DM digestibility (P < 0.05). The response in milk yield, however, was not affected by heat stress. There were no significant differences among treatments for intake energy, heat production, net energy for lactation and net energy for gain. This results of this study disagreed with the assumption that late lactation cows gave priority to increasing body tissue at the expense of milk production under thermal stress. PMID:20163673

Kim, Kyoung Hoon; Kim, Do-Hyung; Oh, Young-Kyoon; Lee, Sung-Sill; Lee, Hyun-Jeong; Kim, Dong-Woon; Seol, Yong-Joo; Kimura, Nobuhiro

2010-02-01

332

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. The results were compared with a control group (Ta=25° C, LD 12:12) and winter acclimatized individuals of both species.Vo2 in cold acclimated mice of both species was significantly increased when compared to the control group and was even higher than the winter acclimatized group when measured below the lower critical temperature. Long scotophase acclimated mice of both species also increased their oxygen consumption significantly when compared to the control group. NST was significantly increased in long scotophase acclimated mice from both species when compared to the control group. The results of this study indicate that the effects of acclimation to long scotophase are similar to those of cold acclimation. As changes in photoperiod are regular, it may be assumed that heat production mechanisms in acclimatization to winter will respond to changes in photoperiodicity.

Haim, A.; Fourie, F. Le R.

1980-09-01

333

Gas production and transport during bench-scale electrical resistance heating of water and trichloroethene.  

PubMed

The effective remediation of chlorinated solvent source zones using in situ thermal treatment requires successful capture of gas that is produced. Replicate electrical resistance heating experiments were performed in a thin bench-scale apparatus, where water was boiled and pooled dense non-aqueous phase liquid (DNAPL) trichloroethene (TCE) and water were co-boiled in unconsolidated silica sand. Quantitative light transmission visualization was used to assess gas production and transport mechanisms. In the water boiling experiments, nucleation, growth and coalescence of the gas phase into connected channels were observed at critical gas saturations of Sgc=0.233±0.017, which allowed for continuous gas transport out of the sand. In experiments containing a colder region above a target heated zone, condensation prevented the formation of steam channels and discrete gas clusters that mobilized into colder regions were trapped soon after discontinuous transport began. In the TCE-water experiments, co-boiling at immiscible fluid interfaces resulted in discontinuous gas transport above the DNAPL pool. Redistribution of DNAPL was also observed above the pool and at the edge of the vapor front that propagated upwards through colder regions. These results suggest that the subsurface should be heated to water boiling temperatures to facilitate gas transport from specific locations of DNAPL to extraction points and reduce the potential for DNAPL redistribution. Decreases in electric current were observed at the onset of gas phase production, which suggests that coupled electrical current and temperature measurements may provide a reliable metric to assess gas phase development. PMID:25084057

Hegele, P R; Mumford, K G

2014-09-01

334

Examination and simulation of effect of Ag2O content on heat mirror production  

NASA Astrophysics Data System (ADS)

We propose a method to determine the effect of Ag2O on heat mirror production processes. A heat mirror is a low emissivity ( low-E ) film with high visible transmittance, high infrared reflectance and vanishing infrared transmittance. We carried out a computer simulation to understand the effect of Ag2O on the spectrum of three-layered low-E films. We then prepared three-layered low-E samples with ITO buffer layers, which were deposited on the Ag layer at 0.6kW, 1kW, and 2kW sputtering power. The simulation showed that the peak visible transmittance decreased, the FWHM of the transmittance widened, and the infrared reflectance was lowered as the amount of Ag2O was increased. In experiments, the three-layered sample with the buffer sputtered at 0.6kW exhibited a lower peak transmittance, broadened FWHM, and decreased infrared reflectance, suggesting that higher levels of Ag2O were introduced. We also prepared five-layered low-E samples, which are of typical heat mirror structures, with buffer layers similar to the three layered samples. The transmittance and reflectance spectrum of the five-layered sample with the buffer sputtered at 0.6kW also suggested a higher Ag2O content than other samples. Therefore, studying the spectrum of the three-layered low-E film, along with the simulation, can be an economical way to optimize manufacturing processes in the production of five-layered low-E films.

Chen, En-Shih; Wu, Jin-Yu; Yang, Chun-Wei; Chang, Shih-Tse; Lin, Wei-Sin; Tseng, Ching-Pei

2013-12-01

335

Effects of steam pretreatment and co-production with ethanol on the energy efficiency and process economics of combined biogas, heat and electricity production from industrial hemp  

PubMed Central

Background The study presented here has used the commercial flow sheeting program Aspen Plus™ to evaluate techno-economic aspects of large-scale hemp-based processes for producing transportation fuels. The co-production of biogas, district heat and power from chopped and steam-pretreated hemp, and the co-production of ethanol, biogas, heat and power from steam-pretreated hemp were analysed. The analyses include assessments of heat demand, energy efficiency and process economics in terms of annual cash flows and minimum biogas and ethanol selling prices (MBSP and MESP). Results Producing biogas, heat and power from chopped hemp has the highest overall energy efficiency, 84% of the theoretical maximum (based on lower heating values), providing that the maximum capacity of district heat is delivered. The combined production of ethanol, biogas, heat and power has the highest energy efficiency (49%) if district heat is not produced. Neither the inclusion of steam pretreatment nor co-production with ethanol has a large impact on the MBSP. Ethanol is more expensive to produce than biogas is, but this is compensated for by its higher market price. None of the scenarios examined are economically viable, since the MBSP (EUR 103–128 per MWh) is higher than the market price of biogas (EUR 67 per MWh). The largest contribution to the cost is the cost of feedstock. Decreasing the retention time in the biogas process for low solids streams by partly replacing continuous stirred tank reactors by high-rate bioreactors decreases the MBSP. Also, recycling part of the liquid from the effluent from anaerobic digestion decreases the MBSP. The production and prices of methane and ethanol influence the process economics more than the production and prices of electricity and district heat. Conclusions To reduce the production cost of ethanol and biogas from biomass, the use of feedstocks that are cheaper than hemp, give higher output of ethanol and biogas, or combined production with higher value products are primarily suggested. Further, practical investigations on increased substrate concentration in biogas and ethanol production, recycling of the liquid in anaerobic digestion and separation of low solids flows into solid and a liquid fraction for improved reactor applications deserves further attention. PMID:23607263

2013-01-01

336

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

NASA Technical Reports Server (NTRS)

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

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

2003-01-01

337

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.

2011-07-01

338

Biobutanol production by a new local isolate of Clostridium acetobutylicum YM1  

NASA Astrophysics Data System (ADS)

Increasing demand of energy and awareness about environmental pollution has led to increase interest in alternative, clean and renewable energy sources. Biobutanol is considered as the candidate liquid biofuel to replace gasoline. In this study, the capability of a newly isolated strain of local Clostridium acetobutylicum YM1 was tested to produce biobutanol in batch fermentation. Various culture conditions including glucose concentration, initial pH, incubation temperature and inoculum size were investigated for their effects on production of biobutanol using strain YM1. The results showed that the optimal biobutanol production was obtained at glucose concentration 50 g/L, initial pH 6.2, temperature 30°C and inoculum size 10%. These results show that C. acetobutylicum YM1 as a mesophilic bacterium is a potential candidate for biobutanol production.

Al-Shorgani, Najeeb Kaid; Tibin, El Mubarak; Kalil, Mohd Sahaid; Yusoff, Wan Mohtar Wan; Hamid, Aidil Abdul

2014-09-01

339

Processes governing phytoplankton blooms in estuaries. I: The local production-loss balance  

USGS Publications Warehouse

The formation and spatial distribution of phytoplankton blooms in estuaries are controlled by (1) local mechanisms, which determine the production-loss balance for a water column at a particular spatial location (i.e. control if a bloom is possible), and (2) transport-related mechanisms, which govern biomass distribution (i.e. control if and where a bloom actually occurs). In this study, the first of a 2-paper series, we use a depth-averaged numerical model as a theoretical tool to describe how interacting local conditions (water column height, light availability, benthic grazing) influence the local balance between phytoplankton sources and sinks. We also explore trends in the spatial variability of the production-loss balance across the topographic gradients between deep channels and lateral shoals which are characteristic of shallow estuaries. For example, under conditions of high turbidity and slow benthic grazing the highest rates of phytoplankton population growth are found in the shallowest regions. On the other hand, with low turbidity and rapid benthic grazing the highest growth rates occur in the deeper areas. We also explore the effects of semidiurnal tidal variation in water column height, as well as spring-neap variability. Local population growth in the shallowest regions is very sensitive to tidal-scale shallowing and deepening of the water column, especially in the presence of benthic grazing. A spring-neap signal in population growth rate is also prominent in the shallow areas. Population growth in deeper regions is less sensitive to temporal variations in tidal elevation. These results show that both shallow and deep regions of estuaries can act as sources or sinks for phytoplankton biomass, depending on the local conditions of mean water column height, tidal amplitude, light-limited growth rate, and consumption by grazers.

Lucas, L.V.; Koseff, J.R.; Cloern, J.E.; Monismith, S.G.; Thompson, J.K.

1999-01-01

340

24 CFR 200.950 - Building product standards and certification program for solar water heating system.  

...certification program for solar water heating system. 200.950 Section...certification program for solar water heating system. (a) Applicable standards. (1) All solar water heating systems shall be designed,...

2014-04-01

341

24 CFR 200.950 - Building product standards and certification program for solar water heating system.  

Code of Federal Regulations, 2010 CFR

...certification program for solar water heating system. 200.950 Section...certification program for solar water heating system. (a) Applicable standards. (1) All solar water heating systems shall be designed,...

2010-04-01

342

24 CFR 200.950 - Building product standards and certification program for solar water heating system.  

Code of Federal Regulations, 2012 CFR

...certification program for solar water heating system. 200.950 Section...certification program for solar water heating system. (a) Applicable standards. (1) All solar water heating systems shall be designed,...

2012-04-01

343

24 CFR 200.950 - Building product standards and certification program for solar water heating system.  

Code of Federal Regulations, 2013 CFR

...certification program for solar water heating system. 200.950 Section...certification program for solar water heating system. (a) Applicable standards. (1) All solar water heating systems shall be designed,...

2013-04-01

344

24 CFR 200.950 - Building product standards and certification program for solar water heating system.  

Code of Federal Regulations, 2011 CFR

...certification program for solar water heating system. 200.950 Section...certification program for solar water heating system. (a) Applicable standards. (1) All solar water heating systems shall be designed,...

2011-04-01

345

Determination of mass and heat transfer parameters during freeze-drying cycles of pharmaceutical products.  

PubMed

The principal aim of this study was to evaluate the water vapour mass transfer resistance of the dried layer and the vial heat transfer coefficient values of a pharmaceutical product during the primary drying period. First, overall vial heat transfer coefficient values, Kv, were determined by a gravimetric method based on pure ice sublimation experiments. Thus, it was possible to set up a map of the total heat flux received by each vial throughout the plate surface of our pilot scale freeze-dryer. Important heterogeneities were observed for the vials placed at the plate edges and for the vials placed at the center of the plate. As well, the same gravimetric method was also used to precisely determine the influence of main lyophilization operating parameters (shelf temperature and gas total pressure) or the vial types and sizes on these overall heat transfer coefficient values. A semi-empirical relationship as a function of total gas pressure was proposed. The transient method by pressure rise analysis (PRA method) after interrupting the water vapour flow between the sublimation chamber and the condenser, previously set up and validated in our laboratory, was then extensively used with an amorphous BSA-based formulation to identify the dried layer mass transfer resistance values, Rp, the ice front temperature, and the total heat transfer coefficient values, Kv, with or without annealing treatment. It was proved that this method gave accurate and coherent data only during the first half of the sublimation period when the totality of the vials of the set was still sublimating. Thus, this rapid method allowed estimation of, on line and in situ, the sublimation front temperature and the characterization of the morphology and structure of the freeze-dried layer, all along the first part of the sublimation period. The estimated sublimation temperatures shown by the PRA model were about 2 degrees C lower than the experimental values obtained using thermocouples inserted inside the vial, in accordance with previous data given by this method for similar freeze-drying conditions. As well, by using this method we could confirm the homogenization of the dried layer porous structure by annealing treatment after the freezing step. Furthermore, frozen matrix structure analysis (mean pore diameter) using optical microscopy and mass transfer modelling of water vapour by molecular diffusion (Knudsen regime) allowed, in some cases, to predict the experimental values of this overall mass transfer resistance directly related to the freeze-dried cake permeability. PMID:15971546

Hottot, A; Vessot, S; Andrieu, J

2005-01-01

346

Local stratification control of marine productivity in the subtropical North Pacific  

NASA Astrophysics Data System (ADS)

Strengthened stratification of the upper ocean due to global warming is generally expected to inhibit marine primary productivity in the subtropics, based on the supposition that increased water column stability will decrease vertical mixing and consequently the entrainment of deep nutrients into the euphotic zone. A recent analysis of observational data from the subtropical North Atlantic, however, demonstrates that productivity in this region is not correlated with stratification on interannual time scales over the modern observational record, but is instead impacted by other dynamics that affect vertical mixing and nutrient supply. Herein, we examine data from the Hawaiian Ocean Time series program's Station ALOHA (A Long-Term Oligotrophic Habitat Assessment) in the subtropical North Pacific. We find that stratification and productivity are not strongly correlated at this location over the observational record. In contrast to the North Atlantic, the weakness of correlation observed at ALOHA may reflect the strongly stratified ecosystem of the eastern subtropical North Pacific and a lack of sufficiently strong interannual forcing in this region. Although basin-wide climate processes (namely El Niño-Southern Oscillation and Pacific Decadel Oscillation) have previously been suggested to impact local stratification and vertical nutrient supply at ALOHA, we find no evidence of a strong or consistent linkage. Comparing local ecosystem variability to the recently identified North Pacific Gyre Oscillation, however, we observe a correlation with local subsurface productivity and salinity. The correlations have similar structure in both space (i.e., depth) and time and are possibly linked to dynamics associated with the formation and advection of water masses in the central gyre.

Dave, Apurva C.; Lozier, M. Susan

2010-12-01

347

Human white adipocytes express the cold receptor TRPM8 which activation induces UCP1 expression, mitochondrial activation and heat production.  

PubMed

Mammals possess two types of adipose tissue, white (WAT) and brown (BAT). The uncoupling protein 1 (UCP1) is a hallmark of BAT, being the pivotal player for cold-induced thermogenesis. WAT can acquire BAT characteristics with up-regulation of UCP1 after cold exposure or adrenergic stimulation. In the present study we demonstrated that human white adipocytes express the cold-sensing receptor TRPM8 which activation by menthol and icilin induced a rise in [Ca²?](i) and UCP1 expression, increased mitochondrial membrane potential, glucose uptake and heat production. The induction of "brown-like" phenotype in human white adipocytes after TRPM8 activation was supported by ultrastructural morphological changes of mitochondrial morphology and of their intracellular localization, with no modifications of the genes regulating mitochondrial biogenesis. In conclusion human white adipocytes express the cold receptor TRPM8 which activation induces their "browning" supporting a possible role of this receptor in the control of adipose tissue metabolism and body energy balance. PMID:24342393

Rossato, Marco; Granzotto, Marnie; Macchi, Veronica; Porzionato, Andrea; Petrelli, Lucia; Calcagno, Alessandra; Vencato, Juri; De Stefani, Diego; Silvestrin, Valentina; Rizzuto, Rosario; Bassetto, Franco; De Caro, Raffaele; Vettor, Roberto

2014-03-01

348

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

NASA Technical Reports Server (NTRS)

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

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

2002-01-01

349

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

NASA Technical Reports Server (NTRS)

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

Tao, W.-K.

2003-01-01

350

Assessing complexity of skin blood flow oscillations in response to locally applied heating and pressure in rats: Implications for pressure ulcer risk  

NASA Astrophysics Data System (ADS)

The objective of this study was to investigate the effects of local heating on the complexity of skin blood flow oscillations (BFO) under prolonged surface pressure in rats. Eleven Sprague-Dawley rats were studied: 7 rats underwent surface pressure with local heating (?t=10 °C) and 4 rats underwent pressure without heating. A pressure of 700 mmHg was applied to the right trochanter area of rats for 3 h. Skin blood flow was measured using laser Doppler flowmetry. The loading period was divided into nonoverlapping 30 min epochs. For each epoch, multifractal detrended fluctuation analysis (MDFA) was utilized to compute DFA coefficients and complexity of endothelial related metabolic, neurogenic, and myogenic frequencies of BFO. The results showed that under surface pressure, local heating led to a significant decrease in DFA coefficients of myogenic frequency during the initial epoch of loading period, a sustained decrease in complexity of myogenic frequency, and a significantly higher degree of complexity of metabolic frequency during the later phase of loading period. Surrogate tests showed that the reduction in complexity of myogenic frequency was associated with a loss of nonlinearity whereas increased complexity of metabolic frequency was associated with enhanced nonlinearity. Our results indicate that increased metabolic activity and decreased myogenic response due to local heating manifest themselves not only in magnitudes of metabolic and myogenic frequencies but also in their structural complexity. This study demonstrates the feasibility of using complexity analysis of BFO to monitor the ischemic status of weight-bearing skin and risk of pressure ulcers.

Liao, Fuyuan; O'Brien, William D.; Jan, Yih-Kuen

2013-10-01

351

Dependence of flight behavior and heat production on air temperature in the green darner dragonfly Anax junius (Odonata: Aeshnidae)  

PubMed

The large, endothermic dragonfly Anax junius regulates the temperatures of its thorax (Tth) and head (Th) during flight. At high ambient temperature (Ta) it is able to dispose of excess heat from the thorax by increasing hemolymph circulation to the abdomen, but recent evidence suggests that heat loss to the abdomen is largely passive at Ta<30 °C. Nevertheless, these insects continue to regulate Tth and Th at least down to 20 °C and probably at much lower values of Ta. As Ta declines, A. junius glide less, probably fly faster when feeding, and increase their wingbeat frequency when patrolling. Presumably as a result of these behavioral changes, heat production, and thus inferred flight metabolic rate, is inversely proportional to Ta. This is the first demonstration based on field data that an insect regulates body temperature while flying by altering heat production. PMID:9320306

May

1995-01-01

352

Heat and Mass Transfer Measurements for Tray-Fermented Fungal Products  

NASA Astrophysics Data System (ADS)

In this study, heat and mass transfer in static tray fermentation, which is widely used in solid-state fermentation (SSF) to produce fungal products, such as enzymes or koji, is investigated. Specifically, kinetic models of transport phenomena in the whole-tray chamber are emphasized. The effects of temperature, moisture, and humidity on microbial growth in large-scale static tray fermentation are essential to scale-up SSF and achieve uniform fermentation. In addition, heat and mass transfer of static tray fermentation of Trichoderma fungi with two tray setups—traditional linen coverings and stacks in a temperature-humidity chamber is examined. In both these setups, the following factors of fermentation were measured: air velocity, air temperature, illumination, pH, carbon dioxide (CO2) concentration, and substrate temperature, and the effects of bed height, moisture of substrate, and relative humidity of air are studied. A thin (1 cm) bed at 28 °C and 95 % relative humidity is found to be optimum. Furthermore, mixing was essential for achieving uniform fermentation of Trichoderma fungi. This study has important applications in large-scale static tray fermentation of fungi.

Jou, R.-Y.; Lo, C.-T.

2011-01-01

353

Deposition behaviour of corrosion products on the Zircaloy heat transfer surface  

NASA Astrophysics Data System (ADS)

The deposition behaviour of corrosion products on the Zircaloy heat transfer surface was examined under four different experimental environments. First, iron oxide deposition on two kinds of Zircaloy surfaces was carried out in order to evaluate the effects of the oxidation state of Zircaloy. Second, the amount of iron oxide deposits on the Zircaloy surface was measured in order to analyse the influence of dissolved hydrogen. Third, nickel oxide deposition was carried out on two Zircaloy surfaces with dense and porous iron oxide layers, respectively, to evaluate the effects of pre-deposited iron oxides. Finally, the effects of Fe 2+ ions on the deposition of iron oxide micro-particles were examined in a suspended hematite solution and a mixed solution containing Fe 2+ ions and suspended hematite. In our results, a heat treatment of the Zircaloy surface was effective for reducing the iron oxide deposition. Dissolved hydrogen and Fe 2+ were found to promote the deposition of the iron oxides. And the amount of nickel oxide deposits was increased on the porous iron oxide layer.

Yeon, Jei-Won; Jung, Yongju; Pyun, Su-Il

2006-08-01

354

Dry period heat stress relief effects on prepartum progesterone, calf birth weight, and milk production.  

PubMed

Effects of cooling high producing dairy cows during the dry period were examined in 84 pluriparous Israeli-Holstein cows. Cooling was by a combination of wetting and forced ventilation from 0600 to 1800 h until parturition and common management afterwards for both groups. Cooling maintained diurnal increase in rectal temperature within .2 degrees C as compared with .5 degrees C in control cows in warmer months, Mean rectal temperatures at 1400 h in control cows were moderate, within 39.2 degrees C. Cooling did not affect prepartum or postpartum body condition score or mean blood progesterone during the dry period. Results suggested a possible increase in blood progesterone in later pregnancy by cooling during hot weather. Cooling increased mean 150-d milk production by 3.6 kg/d (3.1 kg FCM/d). Prepartum cooling negatively affected first lactation month yield in cows calving in early summer. Prepartum cooling might prevent adaptation to heat and impair subsequent postpartum performance. Prepartum progesterone was not related to milk yield. Calves' birth weight increased by cooling, but the effect was mostly in older cows. Birth weight was related to milk yield, independently of cooling effect, mostly in older cows. Cooling during the dry period might increase milk yield as it does during lactation. Results indicate possible benefit of cooling dry cows even under mild heat stress. PMID:3372821

Wolfenson, D; Flamenbaum, I; Berman, A

1988-03-01

355

Performance of a CEBAF production cavity after high-temperature heat treatment  

SciTech Connect

CEBAF`s production cavities are tested in a vertical configuration after appropriate chemical surface treatment prior to installation into the accelerator. The performance of these cavities is excellent, often exceeding the specifications of E{sub acc}=5 MV/m at 2 K by factors of 2 to 3. In such cases the cavities are often limited by thermal-magnetic breakdown. A cavity that exhibited a limiting gradient of E{sub acc} {le} 16.4 MV/m has been heat-treated at 1400{degrees}C for 6 hours in the presence of titanium as a solid state gettering material to improve the thermal stability of the niobium. After the heat treatment a gradient of E{sub acc}=20.5 MV/m corresponding to a peak surface electric field of E{sub peak}=52 MV/m has been measured. In addition to the cavity results, data on thermal conductivity and tensile properties of samples which have undergone the same treatments as the cavity are reported.

Kneisel, P.; Rao, M.

1993-06-01

356

Optimization of the Mu2e Production Solenoid Heat and Radiation Shield  

NASA Astrophysics Data System (ADS)

The Mu2e experiment at Fermilab is designed to study the conversion of a negative muon to electron in the field of a nucleus without emission of neutrinos. Observation of this process would provide unambiguous evidence for physics beyond the Standard Model, and can point to new physics beyond the reach of the LHC. The main parts of the Mu2e apparatus are its superconducting solenoids: Production Solenoid (PS), Transport Solenoid (TS), and Detector Solenoid (DS). Being in the vicinity of the beam, PS magnets are most subjected to the radiation damage. In order for the PS superconducting magnet to operate reliably, the peak neutron flux in the PS coils must be reduced by 3 orders of magnitude by means of sophisticatedly designed massive Heat and Radiation Shield (HRS), optimized for the performance and cost. An issue with radiation damage is related to large residual electrical resistivity degradation in the superconducting coils, especially its Al stabilizer. A detailed MARS15 analysis and optimization of the HRS has been carried out both to satisfy the Mu2e requirements to the radiation quantities (such as displacements per atom, peak temperature and power density in the coils, absorbed dose in the insulation, and dynamic heat load) and cost. Results of MARS15 simulations of these radiation quantities are reported and optimized HRS models are presented; it is shown that design levels satisfy all requirements.

Pronskikh, V. S.; Coleman, R.; Glenzinski, D.; Kashikhin, V. V.; Mokhov, N. V.

2014-03-01

357

Effects of NaCl, sucrose, and storage on rheological parameters of heat induced gels of liquid egg products  

E-print Network

-30 minutes 55 12 Gel strength of egg yolk stored at -10 C (24 hrs. ) then heated at 80 C for 0-30 minutes 57 Figure 13 14 15 Elasticity of egg yolk stored at 24oC (6 hrs. ) then heated at 80 C for 0-30 minutes Elasticity of egg yolk stored at 3 C (18... of liquid egg products utilized fresh, refrigerated or frozen. A counter-flow back extrusion method was used to measure the rheological parameters of gel strength, elasticity, and viscosity of heat induced gels of albumen, yolk, and blended whole egg...

Brough, Joan

1988-01-01

358

Aspen Plus® and economic modeling of equine waste utilization for localized hot water heating via fast pyrolysis.  

PubMed

Aspen Plus(®) based simulation models have been developed to design a pyrolysis process for on-site production and utilization of pyrolysis oil from equine waste at the Equine Rehabilitation Center at Morrisville State College (MSC). The results indicate that utilization of all the available waste from the site's 41 horses requires a 6 oven dry metric ton per day (ODMTPD) pyrolysis system but it will require a 15 ODMTPD system for waste generated by an additional 150 horses at the expanded area including the College and its vicinity. For this a dual fluidized bed combustion reduction integrated pyrolysis system (CRIPS) developed at USDA's Agricultural Research Service (ARS) was identified as the technology of choice for pyrolysis oil production. The Aspen Plus(®) model was further used to consider the combustion of the produced pyrolysis oil (bio-oil) in the existing boilers that generate hot water for space heating at the Equine Center. The model results show the potential for both the equine facility and the College to displace diesel fuel (fossil) with renewable pyrolysis oil and alleviate a costly waste disposal problem. We predict that all the heat required to operate the pyrolyzer could be supplied by non-condensable gas and about 40% of the biochar co-produced with bio-oil. Techno-economic Analysis shows neither design is economical at current market conditions; however the 15 ODMTPD CRIPS design would break even when diesel prices reach $11.40/gal. This can be further improved to $7.50/gal if the design capacity is maintained at 6 ODMTPD but operated at 4950 h per annum. PMID:23845952

Hammer, Nicole L; Boateng, Akwasi A; Mullen, Charles A; Wheeler, M Clayton

2013-10-15

359

Heat shock induces production of reactive oxygen species and increases inner mitochondrial membrane potential in winter wheat cells.  

PubMed

Heat shock leads to oxidative stress. Excessive ROS (reactive oxygen species) accumulation could be responsible for expression of genes of heat-shock proteins or for cell death. It is known that in isolated mammalian mitochondria high protonic potential on the inner membrane actuates the production of ROS. Changes in viability, ROS content, and mitochondrial membrane potential value have been studied in winter wheat (Triticum aestivum L.) cultured cells under heat treatment. Elevation of temperature to 37-50°C was found to induce elevated ROS generation and increased mitochondrial membrane potential, but it did not affect viability immediately after treatment. More severe heat exposure (55-60°C) was not accompanied by mitochondrial potential elevation and increased ROS production, but it led to instant cell death. A positive correlation between mitochondrial potential and ROS production was observed. Depolarization of the mitochondrial membrane by the protonophore CCCP inhibited ROS generation under the heating conditions. These data suggest that temperature elevation leads to mitochondrial membrane hyperpolarization in winter wheat cultured cells, which in turn causes the increased ROS production. PMID:25540005

Fedyaeva, A V; Stepanov, A V; Lyubushkina, I V; Pobezhimova, T P; Rikhvanov, E G

2014-11-01

360

Effects of continental insulation and the partitioning of heat producing elements on the Earth's heat loss  

NASA Astrophysics Data System (ADS)

Continental lithosphere influences heat loss by acting as a local insulator to the convecting mantle and by sequestering heat-producing radioactive elements from the mantle. Continental heat production can have a two-part effect since it decreases the amount of internal heat driving convection, which lowers mantle temperature, while also increasing the local insulating effect of continental lithosphere, which raises mantle temperature. We explored these competing effects using simulations that incorporated enriched continents within a mixed internal- and bottom-heated convecting mantle. Increasing continental surface area was found to enhance global heat loss for a range of heat production distributions and Rayleigh numbers. The effect of enriched continents was evident as a double peak in the continental surface area values that maximize global heat loss. That the presence of continental lithosphere could increase average mantle temperature despite the mantle being depleted suggests that continents can significantly influence mantle potential temperature.

Cooper, C. M.; Lenardic, A.; Moresi, L.

2006-07-01

361

Detection of horse meat contamination in raw and heat-processed meat products.  

PubMed

Europe's recent problems with the adulteration of beef products with horse meat highlight the need for a reliable method for detecting horse meat in food for human consumption. The objective of this study was therefore to develop a reliable monoclonal antibody (mAb) based enzyme-linked immunosorbent assay (ELISA) for horse meat detection. Two mAbs, H3E3 (IgG2b) and H4E7 (IgG2a), were characterized as horse-selective, and competitive ELISAs (cELISAs) employing these mAbs were developed. The cELISAs were found to be capable of detecting levels as low as 1% of horse meat in raw, cooked, and autoclaved ground beef or pork, being useful analytical tools for addressing the health, economic, and ethical concerns associated with adulterating meat products with horse meat. However, due to cross-reaction with raw poultry meat, it is recommended that samples be heated (100 °C for 15 min) prior to analysis to eliminate possible false-positive results. PMID:25474205

Hsieh, Yun-Hwa P; Ofori, Jack A

2014-12-31

362

Autoimmunity to heat shock protein 60 and antigen-specific production of interleukin-10.  

PubMed Central

The immunopathologic sequelae of chlamydial infection are correlated with immune responses to the Chlamydia trachomatis heat shock protein 60 (hsp60). One pathogenic mechanism that may explain this association is the induction of autoimmune responses to self hsp60, since these two proteins share a high degree of amino acid sequence identity. To investigate the conditions under which autoimmune responses can be generated against self hsp60, groups of CBA mice were immunized with recombinant mouse hsp60, recombinant chlamydial hsp60, or both proteins. The data show that autoimmune responses characterized by strong T-cell proliferation and high titers of antibody to self hsp60 are induced only by concurrent immunization with mouse and chlamydial hsp60. Immunization with mouse hsp60 alone induced lymphocytes that secreted high levels of interleukin-10 (IL-10) but did not proliferate in response to in vitro stimulation with mouse hsp60; coimmunization with mouse and chlamydial hsp60s induced lymphocytes that proliferated strongly in response to mouse hsp60, secreted 6-fold less IL-10, and exhibited a 12-fold increase in the ratio of gamma interferon/IL-10 production. Switches in cytokine production patterns may mediate the pathogenesis of hsp60-associated diseases such as C. trachomatis immunopathology. PMID:9125545

Yi, Y; Yang, X; Brunham, R C

1997-01-01

363

Overall and average local heat transfer from a horizontal cylinder in a gas-fluidized bed with an opposing oscillatory flow  

SciTech Connect

The Pulsed Atmospheric Fluidized Bed Combustor (PAFBC), a hybrid combustor concept that couples a pulsed combustor with an atmospheric bubbling fluidized bed, has technical advantages in energy efficiency and emissions. The present study examines fundamental aspects of heat transfer in this hybrid combustor by measuring the effect of an opposing oscillatory flow on the overall and time-averaged local heat transfer in a laboratory scale bubbling gas-fluidized bed. This opposing secondary flow consisted of a steady mean component and an oscillating component thereby modeling the flow in the tailpipe of a pulsed combustor. Data were acquired for a monodisperse distribution of particles with a mean diameter of 345 {micro}m and total fluidization ratios ranging from 1.1 through 2.7. Overall and time-averaged local heat flux measurements from the surface of a submerged horizontal cylinder show that heat transfer characteristics are significantly altered by an opposing oscillatory flow. Increases in overall heat transfer on the order of 12% were identified for operating conditions with low primary and secondary flow rates and low pulse frequencies. These enhancements were identified to be a consequence of significant localized enhancements. The fundamental trends and magnitude of the particle Nusselt number are effectively characterized by a modified form of the Strouhal number.

Pence, D.V. [Univ. of Rhode Island, Kingston, RI (United States). Dept. of Mechanical Engineering and Applied Mechanics; Beasley, D.E. [Clemson Univ., SC (United States). Dept. of Mechanical Engineering

1996-12-31

364

Low-cost multi-vehicle air temperature measurements for heat load assessment in local-scale climate applications  

NASA Astrophysics Data System (ADS)

In the recent years there has been a strong interest in exploring the potential of low-cost measurement devices as alternative source of meteorological monitoring data, especially in the urban areas where high-density observations become crucial for appropriate heat load assessment. One of the simple, but efficient approaches for gathering large amount of spatial data is through mobile measurement campaigns in which the sensors are attached to driving vehicles. However, non-standardized data collecting procedure, instrument quality, their response-time and design, variable device ventilation and radiation protection influence the reliability of the gathered data. We investigate what accuracy can be expected from the data collected through low-cost mobile measurements and whether the achieved quality of the data is sufficient for validation of the state-of-the-art local-scale climate models. We tested 5 types of temperature sensors and data loggers: Maxim iButton, Lascar EL-USB-2-LCD+ and Onset HOBO UX100-003 as market available devices and self-designed solar powered Arduino-based data loggers combined with the AOSONG AM2315 and Sensirion SHT21 temperature and humidity sensors. The devices were calibrated and tested in stationary mode at the Austrian Weather Service showing accuracy between 0.1°C and 0.8°C, which was mostly within the device specification range. In mobile mode, the best response-time was found for self-designed device with Arduino-based data logger and Sensirion SHT21 sensor. However, the device lacks the mechanical robustness and should be further improved for broad-range applications. We organized 4 measurement tours: two taking place in urban environment (Vienna, Austria in July 2011 and July 2013) and two in countryside with complex terrain of Mid-Adriatic islands (Hvar and Korcula, Croatia in August 2013). Measurements were taken on clear-sky, dry and hot days. We combined multiple devices attached to bicycle and cars with different radiation protection. Duration of each measurement tour lasted approximately 2 hours covering the distances in radius of about 10-30 km, logging the air temperature and geographical positioning in intervals of 1-5 seconds. The collected data were aggregated on a 100 m horizontal resolution grid and compared with the local-scale climate modelling simulations with the urban climate model MUKLIMO3 initialized with the atmospheric conditions for a given day. Both measurement and modelling results show similar features for distinct local climate zones (built-up area, near water environment, forest, parks, agricultural area, etc). The spatial gradients in temperature can be assigned to different orographical and land use characteristics. Even if many ambiguities remain in both modelling and the measurement approach, the collected data provide useful information for local-scale heat assessment and can serve as a base to increase the model reliability, especially in areas with low data coverage.

Zuvela-Aloise, Maja; Weyss, Gernot; Aloise, Giulliano; Mifka, Boris; Löffelmann, Philemon; Hollosi, Brigitta; Nemec, Johana; Vucetic, Visnja

2014-05-01

365

Three-Dimensional transient heat conduction in a functionally graded thick plate with a higher-order plate theory and a meshless local Petrov-Galerkin method  

Microsoft Academic Search

We analyze transient heat conduction in a thick functionally graded plate by using a higher-order plate theory and a meshless local Petrov-Galerkin (MLPG) method. The temperature field is expanded in the thickness direction by using Legendre polynomials as basis functions. For temperature prescribed on one or both major surfaces of the plate, modified Lagrange polynomials are used as basis and

L. F. Qian; R. C. Batra

2005-01-01

366

Integration of a Local Economy to the Global and European Markets through Export-Led Growth and Specialized Textile Products Export: Home Textile Production in Denizli - Turkey  

Microsoft Academic Search

Denizli is an inland province of the Agean region, one of the most developed regions in the country. Although textile production for local and internal markets in different small settlements of Denizli Province goes back till ancient times, export of various textile products to European and World markets is a relatively recent phenomenon. With the exception of one state-owned large

Hüseyin Özgür

367

On the existence of another source of heat production for the earth and planets, and its connection with gravitomagnetism.  

PubMed

Recent revised estimates of the Earth's surface heat flux are in the order of 47 TW. Given that its internal radiogenic (mantle and crust) heat production is estimated to be around 20 TW, the Earth has a thermal deficit of around 27 TW. This article will try to show that the action of the gravitational field of the Sun on the rotating masses of the Earth is probably the source of another heat production in order of 54TW, which would satisfy the thermal balance of our celestial body and probably explain the reduced heat flow Qo. We reach this conclusion within the framework of gravitation implied by Einstein's special and general relativity theory (SR, GR). Our results show that it might possible, in principle, to calculate the heat generated by the action of the gravitational field of celestial bodies on the Earth and planets of the Solar System (a phenomenon that is different to that of the gravitational tidal effect from the Sun and the Moon). This result should help physicists to improve and develop new models of the Earth's heat balance, and suggests that contrary to cooling, the Earth is in a phase of thermal balance, or even reheating. PMID:24255828

Elbeze, Alexandre Chaloum

2013-01-01

368

Effect of chemical form, heating, and oxidation products of linoleic acid on rumen bacterial population and activities of biohydrogenating enzymes.  

PubMed

Heating polyunsaturated fatty acids (PUFA) produces oxidation products, such as hydroperoxides, aldehydes, and oxypolymers, which could be responsible at least in part for modification of PUFA rumen biohydrogenation (BH). Three in vitro experiments were conducted to investigate the effects of linoleic acid (cis-9,cis-12-C18:2) oxidation products on BH. In the first experiment, we studied the effects of free linoleic acid (FLA), heated FLA (HFLA, at 150 °C for 6h), triacylglycerols of linoleic acid (TGLA), heated TGLA (HTGLA, at 150 °C for 6h), 13-hydroperoxide (13HPOD), trans-2-decenal (T2D), and hexanal (HEX) on BH in vitro after 6 and 24h of incubation. In the second experiment, aldehydes differing in chain length and degree of unsaturation [pentanal, HEX, heptanal, nonanal, T2D, trans-2,trans-4-decadienal (T2T4D)] were incubated in vitro for 5h in rumen fluid. In the third experiment, 9-hydroperoxide (9HPOD), 13HPOD, HEX, or T2T4D were incubated for 1h in rumen fluid inactivated with chloramphenicol to investigate their effects on enzyme activity. In experiment 1, heat treatment of TGLA generated TGLA oxypolymers, did not affect cis-9,cis-12-C18:2 disappearance, but did decrease BH intermediates, especially trans-11 isomers. Heating FLA decreased cis-9,cis-12-C18:2 disappearance and cis-9,trans-11-CLA and trans-11-C18:1 production. Treatment with HEX and T2D did not affect cis-9,cis-12-C18:2 disappearance and barely affected production of BH intermediates. The bacterial community was affected by 13HPOD compared with FLA and HFLA, in parallel with an increase in trans-10 isomer production after a 6-h incubation. After 24h of incubation, 13HPOD decreased trans-11 isomer production, but to a lesser extent than HFLA. In experiment 2, some weak but significant effects were observed on BH, unrelated to chain length or degree of unsaturation of aldehydes; the bacterial community was not affected. In experiment 3, 9HPOD inhibited ?(9)-isomerization, and both 9HPOD and 13HPOD inhibited ?(12)-isomerization. We concluded that oxypolymers did not affect cis-9,cis-12-C18:2 disappearance. Heating both esterified and free cis-9,cis-12-C18:2 greatly altered ?(12)-isomerization. Aldehydes had few effects. Hydroperoxides are responsible, at least in part, for the effects of fat heating: 13HPOD increased trans-10 isomer production (probably by affecting the bacterial community) and decreased trans-11 isomer production by inhibiting ?(12)-isomerase activity, whereas 9HPOD inhibited both isomerases. PMID:24011948

Kaleem, M; Kaleem, A; Enjalbert, F; Farizon, Y; Troegeler-Meynadier, A

2013-11-01

369

Brittle fracture initiation associated with the strain localization in a heat-affected zone of a low carbon steels  

SciTech Connect

Brittle fracture initiation in the ductile-brittle fracture transition region in the heat-affected zone (HAZ) of weldments of a low carbon steel has been investigated. Consistent with the previous results from blunt notch Charpy tests, brittle fracture initiation was observed in the case of J-integral tests to take place at the intersection of small bainitic ferrite grains of different orientations within a mixed area of bainitic ferrite and quasipolygonal ferrite in proximity to the boundary between a coarse bainitic ferrite. Partial load drop during loading, pop-in phenomena, in fracture mechanics tests in the low-temperature region is caused by essentially the same mechanism as for unstable brittle fracture initiation. Inhomogeneous microstructure in the HAZ gives rise to intense strain localizations in the mixed area of bainitic ferrite and quasipolygonal ferrite due to the constraint of plastic deformation therein and may produce accumulated defects that form an incipient crack for the brittle fracture. Partial load drop proceeds in association with repetitive initiations of brittle facets and their ductile linking. The strong temperature dependence of the magnitude of partial load drop is likely to show that the temperature dependence of the brittle fracture initiation is controlled by the first initiation of a brittle facet and the ductile linking with the following induced facets. Existence of coarse bainitic ferrite grains is a prerequisite for the extension of an incipient crack.

Yokoyama, Ken`ichi; Nagumo, Michihiko [Waseda Univ., Tokyo (Japan). Dept. of Materials Science and Engineering

1998-02-01

370

Evidence of local power deposition and electron heating by a standing electromagnetic wave in electron-cyclotron-resonance plasma  

NASA Astrophysics Data System (ADS)

Microwave plasmas excited at electron-cyclotron resonance were studied in the 0.5-15 mTorr pressure range. In contrast with low-limit pressure conditions where the plasma emission highlights a fairly homogeneous spatial structure, a periodic spatial modulation (period ˜6.2 cm) appeared as pressure increased. This feature is ascribed to a local power deposition (related to the electron density) due to the presence of a standing electromagnetic wave created by the feed electromagnetic field (2.45 GHz) in the cavity formed by the reactor walls. Analysis of the electron energy probability function by Langmuir probe and optical emission spectroscopy further revealed the presence of a high-energy tail that showed strong periodic spatial modulation at higher pressure. The spatial evolution of the electron density and of the characteristic temperature of these high-energy electrons coincides with the nodes (maximum) and antinodes (minimum) of the standing wave. These spatially-modulated power deposition and electron heating mechanisms are then discussed.

Durocher-Jean, A.; Stafford, L.; Dap, S.; Makasheva, K.; Clergereaux, R.

2014-09-01

371

Localization of Heat Shock Protein 27 (Hsp27) in the Rat Gingiva and its Changes with Tooth Eruption  

PubMed Central

Heat shock protein 27 kDa (Hsp27) functions as a molecular chaperon to prevent apoptosis as well as to contribute to the regulation of cell proliferation and differentiation during development. In the present study, the localization of Hsp27 in the oral epithelium of rats and its expression change during formation of the gingiva with the tooth eruption were examined immunohistochemically to elucidate the roles of Hsp27 in the oral mucosa. In adult rats, Hsp27-immunoreactivity was localized in the prickle and granular layers but absent in the basal and horny layers of the oral epithelium. On the other hand, in the outer and sulcular epithelia of the free gingival, Hsp27-immunoreactivity was detected in the whole layers, while it was not found in the proliferation zone of the junctional epithelium immunoreactive for Ki67. In immature rats on 10th postnatal day, Hsp27-immunoreactivity was intense in the prickle and granular layers of the oral epithelium, but was not detected in its basal layer. In rats at the eruptive phase on 15th postnatal day, Hsp27-immunoreactivity was detected in sites of the basal layer adjacent to where the dental cusps penetrated through the oral epithelium. Although the immunoreactivity for Ki67 was found in the basal layer of the oral epithelium, it was not localized in the Hsp27-immunopositive sites of tooth-penetration in the basal layer. Just after the tooth-eruption on 20th postnatal day, Hsp27-immunoreactivity was not found in the stratified squamous epithelium at the dentogingival junction, whereas it was intense in a single layer of cuboidal epithelial cells attached to the tooth neck. Ki67-positive cells were scattered in the stratified squamous epithelium at the dentogingival junction, whereas no positive cells were found in the portion of a single layer of cuboidal epithelial cells. These findings suggest that the outer and sulcular epithelia of the free gingiva have a relatively slower rate of proliferation than other gingival and oral epithelia, and that Hsp27 might inhibit the proliferation of the basal cells. Such specific phenomenon in the free gingiva occurred immediately after the dental cusps were exposed to the oral cavity. PMID:21448314

Sasaki, Au; Yamada, Tohru; Inoue, Katsuyuki; Momoi, Tomoko; Tokunaga, Hiroshi; Sakiyama, Koji; Kanegae, Haruhide; Suda, Naoto; Amano, Osamu

2011-01-01

372

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

373

The sarcomere length dependence of the rate of heat production during isometric tetanic contraction of frog muscles.  

PubMed Central

Heat production and force have been measured as a function of sarcomere length between 1.6 and 3.0 microns during isometric tetani at 0 degree C for two types of frog muscle: sartorius and extensor longus digiti iv (e.l.d. iv). Stable heat rate declines linearly with increasing sarcomere length above 2.20 microns for both e.l.d. iv and sartorius muscles. In sartorius muscle stable heat rate remains at or near its maximum value between 1.75 and 2.20 microns while force decreases. In e.l.d. iv muscle, both stable heat rate and force decline linearly as sarcomere length decreases below 2.20 microns. PMID:6334734

Elzinga, G; Peckham, M; Woledge, R C

1984-01-01

374

Summary of channel catfish and rainbow trout production at the Gallatin Waste Heat Aquaculture Facility, 1979-1980  

SciTech Connect

These studies have indicated that channel catfish and rainbow trout can be intensively cultured in concrete raceways using waste heat effluent water from the Gallatin Steam Plant. Optimum production was attained, especially with channel catfish, when desirable water temperatures and proper environmental conditions occurred. High density culture is possible during the winter and early spring months.

Collins, C.M.; Schweinforth, R.L.; Burton, G.L.

1984-02-01

375

Heat production and efficiency of energy utilization in finishing steers fed diets containing wet distillers grains with solubles (WDGS)  

Technology Transfer Automated Retrieval System (TEKTRAN)

This study was conducted to evaluate heat production (HP) and efficiency of energy utilization in feedlot cattle fed diets containing WDGS. Steers (n=24, BW = 452.5 ± 36.8 kg) were assigned in a randomized complete block design to diets containing 0, 20, 40, or 60% WDGS on a DM basis providing calcu...

376

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

377

Rural Women in Local Agrofood Production: Between Entrepreneurial Initiatives and Family Strategies. A Case Study in Greece  

ERIC Educational Resources Information Center

Recent years have seen a relative flourishing in the Greek countryside of small women's businesses engaged in the production of local traditional agrofood products for an emerging consumer demand for foods of specific quality. In the present article the central research question may be summarized as: "to what extent do these women perceive their…

Anthopoulou, Theodosia

2010-01-01

378

Producer Relationships and Local Development in Fresh Fruit Commodity Chains: An Analysis of Blueberry Production in Entre Ríos, Argentina  

Microsoft Academic Search

Craviotti C. Producer relationships and local development in fresh fruit commodity chains: an analysis of blueberry production in Entre Ríos, Argentina, Regional Studies. In current regional perspectives intangible capitals are considered critical assets of regional economies. The aim of this article is to analyse the role of networks in the development of blueberry production in the province of Entre Ríos,

Clara Craviotti

2011-01-01

379

Producer Relationships and Local Development in Fresh Fruit Commodity Chains: An Analysis of Blueberry Production in Entre Ríos, Argentina  

Microsoft Academic Search

Craviotti C. Producer relationships and local development in fresh fruit commodity chains: an analysis of blueberry production in Entre Ríos, Argentina, Regional Studies. In current regional perspectives intangible capitals are considered critical assets of regional economies. The aim of this article is to analyse the role of networks in the development of blueberry production in the province of Entre Ríos,

Clara Craviotti

2012-01-01

380

Localizing the Holy Grail: Glacial/interglacial variations in atmospheric CO2 and oceanic deepwater production  

NASA Astrophysics Data System (ADS)

The 'Holy Grail' of glacial/interglacial CO_2 research is to identify the major driver for variations in atmospheric CO_2 on this time scale. A simple mechanism has hitherto remained elusive. I use an entirely new approach to the problem, namely a global vertical advection-diffusion balance of tracers in the ocean which shows that the ocean's deepwater production (DWP) is the sought-after physical mechanism. The model adequately reproduces modern pCO_2 and vertical profiles of temperature, ?CO_2, Alkalinity, PO_4, and O_2 in the ocean. Based on recently advanced compelling evidence for reduced glacial DWP, the model will then be shown to explain the glacial pCO_2 of 200~?atm. over a full glacial/interglacial transition (20~ky), model results excellently reproduce the observed temporal evolution of atmospheric CO_2 and deep ocean CaCO_3 saturation. The mechanism also explains the remarkable correlation between Antarctic temperature and CO_2 as recorded in ice cores. The ocean's deepwater production rate is hence identified as the dominant driver of glacial/interglacial CO_2 variations through its effect on the vertical distribution of heat and elements in the sea, initially set into motion in the Southern Hemisphere.

Zeebe, R. E.

2003-04-01

381

Differential effects of foods traditionally regarded as 'heating' and 'cooling' on prostaglandin E(2) production by a macrophage cell line.  

PubMed

Some components of natural foods may enhance or inhibit prostaglandin formation and potentially affect the inflammation condition. A macrophage cell line, RAW264.7, was employed to examine the effects of foods traditionally regarded as 'heating' or 'cooling' on the production of PGE(2), a well-known proinflammatory mediator. Foods traditionally regarded as 'heating' (litchi, longan, and dried longan) or 'cooling' (chrysanthemum flower, bitter gourd, and lotus seed plumule) were extracted sequentially with water and ethyl acetate. The water extracts (WE) and ethyl acetate extracts (EAE) were applied to RAW264.7 macrophages in the presence or absence of LPS (lipopolysaccharide). In the absence of LPS, the WEs from the 'heating foods', litchi, longan, or dried longan had a dose-dependent enhancing effect on PGE(2) production, with respective EC(50)s of 8.4, 16, and 11 mg/ml. This effect was accompanied by significant induction of COX-2 protein expression, as shown by Western blot analysis. In contrast, LPS-induced PGE(2) production was inhibited in a dose-dependent manner by the WEs of the 'cooling foods', chrysanthemum flower, bitter gourd, and lotus seed plumule, with respective IC(50)s of 0.6, 0.13, and 0.08 mg/ml. At the concentrations tested, none of the EAEs had any effect on basal PGE(2 )production, while LPS-induced PGE(2) production was inhibited or increased by the EAE from bitter gourd and longan, respectively. Water-soluble extracts of foods traditionally regarded as 'heating' enhanced basal PGE(2) production, while those from 'cooling' foods significantly inhibited LPS-induced PGE(2) production by the macrophage cell line. This subject merits further study to determine whether appropriate food selection may help patients suffering from chronic inflammatory conditions. PMID:12432225

Huang, Ching Jang; Wu, Mei-Chiao

2002-01-01

382

Combined heat and power has the potential to significantly increase energy production efficiency and thus reduce greenhouse gas emissions, however current market penetration  

E-print Network

1 Combined heat and power has the potential to significantly increase energy production efficiency that California will not reach the targets for combined heat and power set for it by the Air Resources Board (ARB of combined heat and power into the new ARB Emissions Cap and Trade scheme. This potential failure would

Kammen, Daniel M.

383

Parametric Evaluation of Large-Scale High-Temperature Electrolysis Hydrogen Production Using Different Advanced Nuclear Reactor Heat Sources  

SciTech Connect

High Temperature Electrolysis (HTE), when coupled to an advanced nuclear reactor capable of operating at reactor outlet temperatures of 800 °C to 950 °C, has the potential to efficiently produce the large quantities of hydrogen needed to meet future energy and transportation needs. To evaluate the potential benefits of nuclear-driven hydrogen production, the UniSim process analysis software was used to evaluate different reactor concepts coupled to a reference HTE process design concept. The reference HTE concept included an Intermediate Heat Exchanger and intermediate helium loop to separate the reactor primary system from the HTE process loops and additional heat exchangers to transfer reactor heat from the intermediate loop to the HTE process loops. The two process loops consisted of the water/steam loop feeding the cathode side of a HTE electrolysis stack, and the sweep gas loop used to remove oxygen from the anode side. The UniSim model of the process loops included pumps to circulate the working fluids and heat exchangers to recover heat from the oxygen and hydrogen product streams to improve the overall hydrogen production efficiencies. The reference HTE process loop model was coupled to separate UniSim models developed for three different advanced reactor concepts (a high-temperature helium cooled reactor concept and two different supercritical CO2 reactor concepts). Sensitivity studies were then performed to evaluate the affect of reactor outlet temperature on the power cycle efficiency and overall hydrogen production efficiency for each of the reactor power cycles. The results of these sensitivity studies showed that overall power cycle and hydrogen production efficiencies increased with reactor outlet temperature, but the power cycles producing the highest efficiencies varied depending on the temperature range considered.

Edwin A. Harvego; Michael G. McKellar; James E. O'Brien; J. Stephen Herring

2009-09-01

384

Comparison of conventional and solar-water-heating products and industries report  

SciTech Connect

President Carter established a goal that would require installation of at least one million solar water heaters by 1985 and 20 million water-heating systems by the year 2000. The goals established require that the solar industry be sufficiently mature to provide cost-effective, reliable designs in the immediate future. The objective of this study was to provide the Department of Energy with quantified data that can be used to assess and redirect, if necessary, the program plans to assure compliance with the President's goals. Results deal with the product, the industry, the market, and the consumer. All issues are examined in the framework of the conventional-hot-water industry. Based on the results of this solar hot water assessment study, there is documented proof that the solar industry is blessed with over 20 good solar hot water systems. A total of eight generic types are currently being produced, but a majority of the systems being sold are included in only five generic types. The good systems are well-packaged for quality, performance and installation ease. These leading systems are sized and designed to fit the requirements of the consumer in every respect. This delivery end also suffers from a lack of understanding of the best methods for selling the product. At the supplier end, there are problems also, including: some design deficiencies, improper materials selection and, occasionally, the improper selection of components and subsystems. These, in total, are not serious problems in the better systems and will be resolved as this industry matures.

Noreen, D; LeChevalier, R; Choi, M; Morehouse, J

1980-07-11

385

Enhanced seed production under prolonged heat stress conditions in Arabidopsis thaliana plants deficient in cytosolic ascorbate peroxidase 2  

PubMed Central

Reactive oxygen species play a key role in the response of plants to abiotic stress conditions. Their level is controlled in Arabidopsis thaliana by a large network of genes that includes the H2O2-scavenging enzymes cytosolic ascorbate peroxidase (APX) 1 and 2. Although the function of APX1 has been established under different growth conditions, genetic evidence for APX2 function, as well as for the mode of cooperation between APX1 and APX2, is very limited. This study characterized the response of Arabidopsis mutants deficient in APX1, APX2, and APX1/APX2 to heat, salinity, light, and oxidative stresses. The findings reveal that deficiency in APX2 resulted in a decreased tolerance to light stress, as well as an enhanced tolerance to salinity and oxidative stresses. Interestingly, plants lacking APX2 were more sensitive to heat stress at the seedling stage, but more tolerant to heat stress at the reproductive stage. Cooperation between APX1 and APX2 was evident during oxidative stress, but not during light, salinity, or heat stress. The findings demonstrate a role for APX2 in the response of plants to light, heat, salinity, and oxidative stresses. The finding that plants lacking APX2 produced more seeds under prolonged heat stress conditions suggests that redundant mechanisms activated in APX2-deficient plants during heat stress play a key role in the protection of reproductive tissues from heat-related damage. This finding is very important because heat-associated damage to reproductive tissues in different crops is a major cause for yield loss in agriculture production worldwide. PMID:23183257

Mittler, Ron

2013-01-01

386

Local Magmatic Episodes and Heat Sources for Hydrothermal Activity in the Kawerau Geothermal Field, Taupo Volcanic Zone, New Zealand  

NASA Astrophysics Data System (ADS)

Kawerau Geothermal Field is the most northeasterly of the major, high-temperature geothermal fields in the central Taupo Volcanic Zone (TVZ, New Zealand), an intensely active Quaternary arc locus of rhyolitic volcanism and thermal output. Kawerau is situated at a transition where the voluminous silicic volcanism and associated magmatism of the central TVZ merge into the andesite-dacite dominated northern TVZ. Structurally, the Kawerau system lies within the southern part of the northeast-trending Whakatane Graben, in a zone where the active TVZ rift structures intersect the north-trending strike-slip faults of the North Island Shear Belt. The field is hosted in 600-1000 m of volcanic rocks and sediments overlying faulted Mesozoic basement greywacke. Fractured coherent rhyolite lava bodies occur between 0 and -1000 m below sea level, with several bodies intersected by drilling. These rhyolites represent local upper-crustal sources of magma, which could have provided heat input for past geothermal systems. Differentiating these rhyolites is important in deciphering the timing of past thermal events, and whether the modern field is long-lived or episodically rejuvenated. Age determinations obtained from samples of the rhyolite using single-crystal U-Pb dating on zircon (Secondary Ion Mass Spectrometry, using the SHRIMP-RG instrument) show the rhyolite bodies to belong to two periods of eruptive activity, one around 360 ka, the other around 140 ka. The older, more voluminous episode is represented by two petrographic magma types, each sampled as a buried surficial lava dome, and one or more buried intersections of sills. The younger episode is represented by modern surficial domes and by two intersections of dike feeders within the greywacke basement. Previous interpretations of the current Kawerau Geothermal Field as a long-lived system are now questioned, as it is apparent that only at long-spaced intervals is there evidence of magma at shallow enough crustal levels beneath the field to generate vigorous hydrothermal activity (as at the present day). The contrast between earlier sill emplacement and later diking is taken as reflecting a change in orientation of the principal stress axes at the field from ?3 vertical around 360 ka, to ?3 horizontal and orientated northwest-southeast (i.e., the modern TVZ orientation) by ca. 140 ka. The age data have provided key insights into the temporal evolution of rhyolitic magmatic activity at Kawerau, with the intrusive complexes representing past heat sources that have given rise to temporally discrete, geographically coincident 'Kawerau geothermal systems'.

Milicich, S. D.; Wilson, C. J.; Bignall, G.; Pezaro, B.

2012-12-01

387

Second law analysis in heat transfer  

Microsoft Academic Search

The second law of thermodynamics is used as a basis for evaluating the irreversibility (entropy generation) associated with simple heat transfer processes. In the first part of this paper, the irreversibility production is analyzed from the local level, at one point in a convective heat transfer arrangement. The second part of the paper is devoted to a limited review of

A. Bejan

1980-01-01

388

Local measurement and numerical modeling of mass/heat transfer from a turbine blade in a linear cascade with tip clearance  

NASA Astrophysics Data System (ADS)

Local mass/heat transfer measurements from the turbine blade near-tip and the tip surfaces are performed using the naphthalene sublimation technique. The experiments are conducted in a linear cascade consisting of five high-pressure blades with a central test-blade configuration. The incoming flow conditions are close to those of the gas turbine engine environment (boundary layer displacement thickness is about 0.01 of chord) with an exit Reynolds number of 6.2 x 105. The effects of tip clearance level (0.86%--6.90% of chord), mainstream Reynolds number and turbulence intensity (0.2 and 12.0%) are investigated. Two methods of flow visualization---oil and lampblack, laser light sheet smoke wire---as well as static pressure measurement on the blade surface are used to study the tip leakage flow and vortex in the cascade. In addition, numerical modeling of the flow and heat transfer processes in the linear cascade with different tip clearances is conducted using commercial software incorporating advanced turbulence models. The present study confirms many important results on the tip leakage flow and vortex from the literature, contributes to the current understanding in the effects of tip leakage flow and vortex on local heat transfer from the blade near-tip and the tip surfaces, and provides detailed local and average heat/mass transfer data applicable to turbine blade tip cooling design.

Jin, Peitong

2000-11-01

389

Quantitative prediction of radio frequency induced local heating derived from measured magnetic field maps in magnetic resonance imaging: A phantom validation at 7 T  

NASA Astrophysics Data System (ADS)

Electrical Properties Tomography (EPT) technique utilizes measurable radio frequency (RF) coil induced magnetic fields (B1 fields) in a Magnetic Resonance Imaging (MRI) system to quantitatively reconstruct the local electrical properties (EP) of biological tissues. Information derived from the same data set, e.g., complex numbers of B1 distribution towards electric field calculation, can be used to estimate, on a subject-specific basis, local Specific Absorption Rate (SAR). SAR plays a significant role in RF pulse design for high-field MRI applications, where maximum local tissue heating remains one of the most constraining limits. The purpose of the present work is to investigate the feasibility of such B1-based local SAR estimation, expanding on previously proposed EPT approaches. To this end, B1 calibration was obtained in a gelatin phantom at 7 T with a multi-channel transmit coil, under a particular multi-channel B1-shim setting (B1-shim I). Using this unique set of B1 calibration, local SAR distribution was subsequently predicted for B1-shim I, as well as for another B1-shim setting (B1-shim II), considering a specific set of parameter for a heating MRI protocol consisting of RF pulses plaid at 1% duty cycle. Local SAR results, which could not be directly measured with MRI, were subsequently converted into temperature change which in turn were validated against temperature changes measured by MRI Thermometry based on the proton chemical shift.

Zhang, Xiaotong; Van de Moortele, Pierre-Francois; Liu, Jiaen; Schmitter, Sebastian; He, Bin

2014-12-01

390

Solid waste from Swine wastewater as a fuel source for heat production.  

PubMed

This study was to evaluate the feasibility of recycling the solids separated from swine wastewater treatment process as a fuel source for heat production and to provide a data set on the gas emissions and combustion properties. Also, in this study, the heavy metals in ash content were analyzed for its possible use as a fertilizer. Proximate analysis of the solid recovered from the swine wastewater after flocculation with organic polymer showed high calorific (5,330.50 kcal/kg) and low moisture (15.38%) content, indicating that the solid separated from swine wastewater can be used as an alternative fuel source. CO and NOx emissions were found to increase with increasing temperature. Combustion efficiency of the solids was found to be stable (95 to 98%) with varied temperatures. Thermogravimetry (TG) and differential thermal analysis (DTA) showed five thermal effects (four exothermic and one endothermic), and these effects were distinguished in three stages, water evaporation, heterogeneous combustion of hydrocarbons and decomposition reaction. Based on the calorific value and combustion stability results, solid separated from swine manure can be used as an alternative source of fuel, however further research is still warranted regarding regulation of CO and NOx emissions. Furthermore, the heavy metal content in ash was below the legal limits required for its usage as fertilizer. PMID:25049526

Park, Myung-Ho; Kumar, Sanjay; Ra, ChangSix

2012-11-01

391

The critical role of extreme heat for maize production in the United States  

NASA Astrophysics Data System (ADS)

Statistical studies of rainfed maize yields in the United States and elsewhere have indicated two clear features: a strong negative yield response to accumulation of temperatures above 30°C (or extreme degree days (EDD)), and a relatively weak response to seasonal rainfall. Here we show that the process-based Agricultural Production Systems Simulator (APSIM) is able to reproduce both of these relationships in the Midwestern United States and provide insight into underlying mechanisms. The predominant effects of EDD in APSIM are associated with increased vapour pressure deficit, which contributes to water stress in two ways: by increasing demand for soil water to sustain a given rate of carbon assimilation, and by reducing future supply of soil water by raising transpiration rates. APSIM computes daily water stress as the ratio of water supply to demand, and during the critical month of July this ratio is three times more responsive to 2°C warming than to a 20% precipitation reduction. The results suggest a relatively minor role for direct heat stress on reproductive organs at present temperatures in this region. Effects of elevated CO2 on transpiration efficiency should reduce yield sensitivity to EDD in the coming decades, but at most by 25%.

Lobell, David B.; Hammer, Graeme L.; McLean, Greg; Messina, Carlos; Roberts, Michael J.; Schlenker, Wolfram

2013-05-01

392

Lunar South Pole ice as heat sink for Lunar cryofuel production system  

SciTech Connect

Recent Clementine bistatic radar data suggest that water ice may be present in a {open_quotes}forever shaded{close_quotes} depression or crater at the South Pole of the Moon. The ice is a feedstock for the electrolysis production of cryogenic oxygen and hydrogen rocket fuels for a transportation system on the moon and for leaving and descending on to the moon. The ice also provides a convective heat sink critical to the practical implementation of high throughput electric power generators and refrigerators that liquefy and cool the oxygen and hydrogen into cryogenic rocket fuel. This brief analysis shows that about a hundred tonnes of hardware delivered to the lunar surface can produce tens of thousands of tonnes of rocket fuel per year, on the moon. And it makes the point that if convective cooling is used instead of radiative cooling, then power and processing systems can be used that exist and have been tested already. This shortens the time by an order of magnitude to develop lunar operations. Quick deployment of a chemical cryofuel energy source is a key factor in the economics of lunar development.

Zuppero, A.; Stanley, M.; Modro, S.M. [Idaho National Engineering Lab., Idaho Falls, ID (United States); Whitman, P. [Univ. of Southwestern Louisiana, Lafayette, LA (United States)

1995-03-01

393

Cooperation between the products of different nuclei in hybrid myotubes produces localized acetylcholine receptor clusters.  

PubMed Central

Cultured myotubes form clusters of acetylcholine receptors (AChRs) spontaneously and at sites of nerve-muscle contact. To investigate the cellular mechanisms by which spontaneous clusters are formed, we have made hybrid myotubes between a mouse muscle cell variant, S27, that does not cluster AChRs, and one that does not make AChRs. We have also made hybrid myotubes using S27 and quail muscle cells. In both cases, clusters of AChRs were found near the non-S27 nuclei; in the case of the interspecific hybrids, mouse AChRs were associated with extracellular matrix components contributed by the quail nuclei. Our results suggest that AChRs made by one nucleus can be clustered by localized extracellular matrix produced by a different nucleus and provide an example of nuclear cooperation between the products of different nuclei within multinucleated muscle fibers. Images PMID:1631161

Gordon, H; Ralston, E; Hall, Z W

1992-01-01

394

Storage sizing for embedding of local gas production in a micro gas grid  

NASA Astrophysics Data System (ADS)

In this paper we study the optimal control of a micro grid of biogas producers. The paper considers the possibility to have a local storage device for each producer, who partly consumes his own production, i.e. prosumer. In addition, connected prosumers can sell stored gas to create revenue from it. An optimization model is employed to derive the size of storage device and to provide a pricing mechanism in an effort to value the stored gas. Taking into account physical grid constraints, the model is constructed in a centralized scheme of model predictive control. Case studies show that there is a relation between the demand and price profiles in terms of peaks and lows. The price profiles generally follow each other. The case studies are employed as well to to study the impacts of model parameters on deriving the storage size.

Alkano, D.; Nefkens, W. J.; Scherpen, J. M. A.; Volkerts, M.

2014-12-01

395

Study of the composition of products of controlled nucleosynthesis by local auger-electron spectroscopy  

E-print Network

By local Auger-electron spectroscopy on solid targets and accumulating screens, we studied the composition of nucleosynthesis products, in which we expected to reveal the presence of long-lived transuranium elements (LTE). In a number of cases for analyzed elements in complicated spectra the Auger-spectra of corresponding pure elements or their simple compounds were registered with a high signal-to-noise ratio. As artifacts of the analysis, we consider such phenomena as the electric charging, characteristic losses of energy, and chemical shift. We found the unidentifiable Auger-peaks with energies of 172, 527, 1096, 94, and 560 eV and the doublet of peaks with energies of 130 and 115 eV. We failed to refer them to any Auger-peaks of chemical elements in the atlases and catalogs or to any artifacts. As one of the variants of interpretation of the revealed peaks, we consider the assumption about their affiliation to LTE.

Adamenko, S V; Ponomarev, S S

2004-01-01

396

Study of the composition of products of controlled nucleosynthesis by local auger-electron spectroscopy  

E-print Network

By local Auger-electron spectroscopy on solid targets and accumulating screens, we studied the composition of nucleosynthesis products, in which we expected to reveal the presence of long-lived transuranium elements (LTE). In a number of cases for analyzed elements in complicated spectra the Auger-spectra of corresponding pure elements or their simple compounds were registered with a high signal-to-noise ratio. As artifacts of the analysis, we consider such phenomena as the electric charging, characteristic losses of energy, and chemical shift. We found the unidentifiable Auger-peaks with energies of 172, 527, 1096, 94, and 560 eV and the doublet of peaks with energies of 130 and 115 eV. We failed to refer them to any Auger-peaks of chemical elements in the atlases and catalogs or to any artifacts. As one of the variants of interpretation of the revealed peaks, we consider the assumption about their affiliation to LTE.

S. V. Adamenko; A. S. Adamenko; S. S. Ponomarev

2004-04-29

397

Assessing complexity of skin blood flow oscillations in response to locally applied heating and pressure in rats: implications for pressure ulcer risk  

PubMed Central

The objective of this study was to investigate the effects of local heating on complexity of skin blood flow oscillations (BFO) under prolonged surface pressure in rats. Eleven Sprague–Dawley rats were studied: 7 rats underwent surface pressure with local heating (?t = 10 °C) and 4 rats underwent pressure without heating. A pressure of 700 mmHg was applied to the right trochanter area of rats for 3 h. Skin blood flow was measured using laser Doppler flowmetry. The loading period was divided into nonoverlapping 30 min epochs. For each epoch, multifractal detrended fluctuation analysis (MDFA) was utilized to compute DFA coefficients and complexity of endothelia related metabolic, neurogenic, and myogenic frequencies of BFO. The results showed that under surface pressure, local heating led to a significant decrease in DFA coefficients of myogenic frequency during the initial epoch of loading period, a sustained decrease in complexity of myogenic frequency, and a significantly higher degree of complexity of metabolic frequency during the later phase of loading period. Surrogate tests showed that the reduction in complexity of myogenic frequency was associated with a loss of nonlinearity whereas increased complexity of metabolic frequency was associated with enhanced nonlinearity. Our results indicate that increased metabolic activity and decreased myogenic response due to local heating manifest themselves not only in magnitudes of metabolic and myogenic frequencies but also in their structural complexity. This study demonstrates the feasibility of using complexity analysis of BFO to monitor the ischemic status of weight-bearing skin and risk of pressure ulcers. PMID:24319315

Liao, Fuyuan; O’Brien, William D.; Jan, Yih-Kuen

2013-01-01

398

Toward an Improved Understanding of the Tropical Energy Budget Using TRMM-based Atmospheric Radiative Heating Products  

NASA Astrophysics Data System (ADS)

It is widely recognized that clouds and precipitation exert a profound influence on the propagation of radiation through the Earth's atmosphere. In fact, feedbacks between clouds, radiation, and precipitation represent one of the most important unresolved factors inhibiting our ability to predict the consequences of global climate change. Since its launch in late 1997, the Tropical Rainfall Measuring Mission (TRMM) has collected more than a decade of rainfall measurements that now form the gold standard of satellite-based precipitation estimates. Although not as widely advertised, the instruments aboard TRMM are also well-suited to the problem of characterizing the distribution of atmospheric heating in the tropics and a series of algorithms have recently been developed for estimating profiles of radiative and latent heating from these measurements. This presentation will describe a new multi-sensor tropical radiative heating product derived primarily from TRMM observations. Extensive evaluation of the products using a combination of ground and satellite-based observations is used to place the dataset in the context of existing techniques for quantifying atmospheric radiative heating. Highlights of several recent applications of the dataset will be presented that illustrate its utility for observation-based analysis of energy and water cycle variability on seasonal to inter-annual timescales and evaluating the representation of these processes in numerical models. Emphasis will be placed on the problem of understanding the impacts of clouds and precipitation on atmospheric heating on large spatial scales, one of the primary benefits of satellite observations like those provided by TRMM.

L'Ecuyer, T.; McGarragh, G.; Ellis, T.; Stephens, G.; Olson, W.; Grecu, M.; Shie, C.; Jiang, X.; Waliser, D.; Li, J.; Tian, B.

2008-05-01

399

Systemic but not local infections elicit immunosuppressive IL-10 production by Natural Killer cells  

PubMed Central

Summary IL-10 is an anti-inflammatory mediator, important in limiting immunopathology. Its impact is influenced both by the timing and localization of its release. Here we show that NK cells rapidly express IL-10 during acute infection with the rapidly disseminating pathogens Toxoplasma gondii, Listeria monocytogenes or Yersinia pestis. Direct IL-12 signals proved necessary and sufficient for NK induction of IL-10. NK cells from T. gondii-infected mice inhibited dendritic cell release of IL-12 in an IL-10-dependent manner and NK cell depletion resulted in elevated serum IL-12. Together these data suggest an innate, negative feedback loop, in which IL-12 limits its own production by eliciting IL-10 from NK cells. In contrast to the systemic pathogens, NK cell IL-10 was not elicited by locally restricted infection with influenza virus or with a Y. pestis strain attenuated to prevent dissemination. Thus, systemic infections uniquely engage NK cells in an IL-10-mediated immunoregulatory circuit that functions to alleviate inflammation during sepsis. PMID:20006839

Perona-Wright, Georgia; Mohrs, Katja; Szaba, Frank M.; Kummer, Lawrence W.; Madan, Rajat; Karp, Christopher L.; Johnson, Lawrence L.; Smiley, Stephen T.; Mohrs, Markus

2009-01-01

400

Alteration of fasting heat production during fescue toxicosis in Holstein steers.  

PubMed

This study was designed to examine alteration of fasting heat production (FHP) during fescue toxicosis. Six ruminally cannulated Holstein steers (BW = 348 ± 13 kg) were BW-matched into pairs and used in a 2 period crossover design experiment. Each period consisted of 2 temperature segments, one each at 22 and 30°C. During each period, 1 steer per pair was ruminally dosed twice daily with 0.5 kg of ground endophyte-infected fescue seed (E+) and the other with ground endophyte-free fescue seed (E-) for 7 d. Steers on E- treatment were pair-fed to E+ steers offered alfalfa cubes at 1.5 × NEm. On d 8 of each segment, steers were moved to individual metabolism stalls fitted with indirect calorimetry head boxes. Ruminal contents were removed, weighed, and subsampled for DM determinations. The reticulorumen was washed and filled with a buffer (NaCl = 96; NaHCO3 = 24; KHCO3 = 30; K2HPO4 = 2; CaCl2 = 1.5; MgCl2 = 1.5 mmol·kg buffer(-1)) that was gassed with a 75% N2 and 25% CO2 mixture before rumen incubation. During buffer incubation, an E+ or E- fescue seed extract was added at 12 h intervals to maintain treatment presentation to the animal. After a 12-h wait, heart rate, O2 consumption, CO2 production, and urinary output were recorded for 16 h. There was no difference (P = 0.931) in DMI/kg(0.75) between endophyte treatments by design; however, intake decreased (P = 0.004) at 30°C. Increased temperature had no effect (P > 0.10) on other measurements and there were no significant interactions (P > 0.11) of temperature and endophyte treatment. Heart rate was unaffected by fescue treatment or environmental temperature. Percent DM of ruminal contents as well as total rumen DM/kg(0.75) was increased (P < 0.0001) in E+ steers. Respiratory quotient was elevated (P = 0.02) in E+ steers. Oxygen consumption decreased (P = 0.04) and CO2 production tended to be reduced (P = 0.07) during E+ treatment. Calculated FHP (kcal/kg BW(0.75)) was also less (P = 0.006) in steers receiving E+ treatment. These data suggest that consumption of endophyte-infected tall fescue by cattle results in a reduction in basal metabolic rate. PMID:23908162

Koontz, A F; Kim, D H; Foote, A P; Bush, L P; Klotz, J L; McLeod, K R; Harmon, D L

2013-08-01

401

Heat Production and Storage Are Positively Correlated with Measures of Body Size/Composition and Heart Rate Drift during Vigorous Running  

ERIC Educational Resources Information Center

The purposes of this study were to determine the relationships between: (a) measures of body size/composition and heat production/storage, and (b) heat production/storage and heart rate (HR) drift during running at 95 % of the velocity that elicited lactate threshold, which was determined for 20 healthy recreational male runners. Subsequently,…

Buresh, Robert; Berg, Kris; Noble, John

2005-01-01

402

New heat flow measurements in the Ulleung Basin, East Sea (Sea of Japan): relationship to local BSR depth, and implications for regional heat flow distribution  

NASA Astrophysics Data System (ADS)

In July 2007, new marine heat flow data were collected at ten sites (HF01-10) in the central and southwestern sectors of the Ulleung Basin (East Sea or Sea of Japan) as part of regional gas hydrate research. In addition, cores were collected at five of these sites for laboratory analysis. The results show that the geothermal gradient ranged from 103-137 mK/m, and the in-situ thermal conductivity from 0.82-0.95 W/m·K. Laboratory measurements of thermal conductivity were found to deviate by as much as 40% from the in-situ measurements, despite the precautions taken to preserve the cores. Based on the in-situ conductivity, the heat flow was found to increase with water depth toward the center of the basin, ranging from 84-130 mW/m2. Using a simple model, we estimated the heat flow from the depths of the BSR, and compared this with the observed heat flow. In our study area, the two sets of values were quite consistent, the observed heat flows being slightly higher than the BSR-derived ones. The evaluation of regional pre-1994 data revealed that the heat flow varied widely from 51-157 mW/m2 in and around the basin. Due to a large scatter in these older data, a clear relationship between heat flow and water depth was not evident, in contrast to what would be expected for a rifted sedimentary basin. This raises the question as to whether the pre-1994 data represent the true background heat flow from the underlying basin crust since the basin opening, and/or whether they contain large measurement errors. In fact, evidence in support of the latter explanation exists. BSRs are generally found in the deep parts of the basin, and vary by only ±15 m in depth below the seafloor. From the average BSR depth, we inferred the background heat flow using a simple model, which in the case of the Ulleung Basin is approximately 120 and 80 mW/m2 for 2.5 and 1 km below sea level, respectively.

Kim, Young-Gyun; Lee, Sang-Mook; Matsubayashi, Osamu

2010-12-01

403

Protein-induced Local DNA Bends Regulate Global Topology of Recombination Products  

PubMed Central

The tyrosine family of recombinases produces two smaller DNA circles when acting on circular DNA harboring two recombination sites in head-to-tail orientation. If the substrate is supercoiled, these circles can be unlinked or form multiply linked catenanes. The topological complexity of the products varies strongly even for similar recombination systems. This dependence has been solved in the current study. Our computer simulation of the synapsis showed that the bend angles, ?, created in isolated recombination sites by protein binding before assembly of the full complex, determine the product topology. To verify the validity of this theoretical finding we measured the values of ? for Cre/loxP and Flp/FRT systems. The measurement was based on cyclization of the protein-bound short DNA fragments in solution. Despite the striking similarity of the synapses for these recombinases, action of Cre on head-to-tail target sites produces mainly unlinked circles, while that of Flp yields multiply linked catenanes. In full agreement with theoretical expectations we found that the values of ? for these systems are very different, close to 35° and 80°, respectively. Our findings have general implications in how small protein machines acting locally on large DNA molecules exploit statistical properties of their substrates to bring about directed global changes in topology. PMID:17337001

Du, Quan; Livshits, Alexei; Kwiatek, Agnieszka; Jayaram, Makkuni; Vologodskii, Alexander

2007-01-01

404

Production and characterization of violacein by locally isolated Chromobacterium violaceum grown in agricultural wastes.  

PubMed

The present work highlighted the production of violacein by the locally isolated Chromobacterium violaceum (GenBank accession no. HM132057) in various agricultural waste materials (sugarcane bagasse, solid pineapple waste, molasses, brown sugar), as an alternative to the conventional rich medium. The highest yield for pigment production (0.82 g L?¹) was obtained using free cells when grown in 3 g of sugarcane bagasse supplemented with 10% (v/v) of L-tryptophan. A much lower yield (0.15 g L?¹) was obtained when the cells were grown either in rich medium (nutrient broth) or immobilized onto sugarcane bagasse. Violacein showed similar chemical properties as other natural pigments based on the UV-Vis, Fourier transform infrared spectroscopy, thin-layer chromatography, nuclear magnetic resonance, and mass spectrometry analysis. The pigment is highly soluble in acetone and methanol, insoluble in water or non-polar organic solvents, and showed good stability between pH 5-9, 25-100 °C, in the presence of light metal ions and oxidant such as H?O?. However, violacein would be slowly degraded upon exposure to light. This is the first report on the use of cheap and easily available agricultural wastes as growth medium for violacein-producing C. violaceum. PMID:22278051

Ahmad, Wan Azlina; Yusof, Nur Zulaikha; Nordin, Nordiana; Zakaria, Zainul Akmar; Rezali, Mohd Fazlin

2012-07-01

405

Persistence of local cytokine production in shigellosis in acute and convalescent stages.  

PubMed Central

Shigella infection is accompanied by an intestinal activation of epithelial cells, T cells, and macrophages within the inflamed colonic mucosa. A prospective study was carried out to elucidate the cytokine pattern in Shigella infection linked to development of immunity and eradication of bacteria from the local site and also to correlate the cytokine profile with histological severity. An indirect immunohistochemical technique was used to determine the production and localization of various cytokines at the single-cell level in cryopreserved rectal biopsies from 24 patients with either Shigella dysenteriae type 1 (n = 18) or Shigella flexneri (n = 6) infection. The histopathological profile included presence of chronic inflammatory cells with or without neutrophils and microulcers in the lamina propria, crypt distortion, branching, and less frequently crypt abscesses. Patients had significantly higher (P < 0.005) numbers of cytokine producing cells for all of the cytokines studied, interleukin-1 alpha (IL-1 alpha), IL-1 beta, IL-1ra, tumor necrosis factor alpha (TNF-alpha), IL-6, IL-8, IL-4, IL-10, gamma interferon, TNF-beta, and transforming growth factor beta 1-3, in the biopsies than the healthy controls (n = 13). The cytokine production profile during the study period was dominated by IL-1 beta, transforming growth factor beta 1-3, IL-4, and IL-10. Significantly increased frequencies of cytokine-producing cells (P < 0.05) were observed for IL-1, IL-6, gamma interferon, and TNF-alpha in biopsies with severe inflammation in comparison with those with mild inflammation. During the acute stage of the disease, 20 of 24 patients exhibited acute inflammation in the rectal biopsies and the cellular infiltration was still extensive 30 days after the onset of diarrhea, although the disease was clinically resolved. In accordance with the histological findings, cytokine production was also upregulated during the convalescent phase; there was no significant difference (P > 0.05) in the incidence of cytokine-producing cells between acute (2 to 8 days after the onset of diarrhea) and convalescent (30 days after onset) stages. PMID:7806368

Raqib, R; Lindberg, A A; Wretlind, B; Bardhan, P K; Andersson, U; Andersson, J

1995-01-01

406

History of the development and industrial production of low thermal emissivity coatings for high heat insulating glass units.  

PubMed

Low-emissivity (low-E) coatings play a dominate role in high heat insulating multiple glass units with which an essential part of heat energy can be saved in buildings. With such coatings as the main part, and to a lesser part with low thermal conductive filling gases of the units' interspaces, their heat transmittance can be reduced from 6.0 W/m(2)? K for a single glazing--still glazed to a high degree--to 0.4 W/m(2) K for a triple insulating glass unit. This astonishing development is regarded as one of the most important innovations of the flat glass industry in the past century. The roots of low-E coatings in the 1960s, their startup for production in the 1970s, and, most important, further development steps accompanied by, and partly also codesigned actively by the author, are depicted. PMID:18449246

Gläser, Hans J

2008-05-01

407

The Costs of Increased Localization for a Multiple-Product Food Supply Chain: Dairy in the United States  

Microsoft Academic Search

There is increased interest in greater localization of food supply chains but little evidence about the effects of localization on supply chain costs. Assessing these effects is complex in multiple-product, multi-process supply chains such as the dairy industry. In this study, we develop a spatially-disaggregated transshipment model for the US dairy sector that minimizes total supply chain costs, including assembly,

Charles F. Nicholson; Miguel I. Gomez; Oliver H. Gao

2010-01-01

408

The costs of increased localization for a multiple-product food supply chain: Dairy in the United States  

Microsoft Academic Search

There is increased interest in greater localization of food supply chains but little evidence about the effects of localization on supply-chain costs. Assessing these effects is complex in multiple-product, multi-process supply chains such as the dairy industry. In this study, we develop a spatially-disaggregated transshipment model for the US dairy sector that minimizes total supply-chain costs, including assembly, processing, interplant

Charles F. Nicholson; Miguel I. Gómez; Oliver H. Gao

2011-01-01

409

Large-Scale Heat Exchange and Ice Production in the Central Arctic  

Microsoft Academic Search

The arctic ice pack is a mixture of ice of many different thicknesses. Ice growth and heat exchange are strongly influenced by thickness, particularly when the ice is thin. For this reason measurements at a particular location do not necessarily represent conditions elsewhere within the region. Large-scale heat exchange estimates must take into account contributions made by different thicknesses of

Gary A. Maykut

1982-01-01

410

Energy production from waste heat by means of elastomers or memory metals  

Microsoft Academic Search

Calculation of the energy of an ideal heat engine for a flow between waste water and cooling water was made. Also the Brayton, Carnot and Rankine cycles were computed as well as the processes with nitinol or elastomers as converters. It was shown that half the energy can be recovered by a nitinol heat engine which is comparable to or

L. Ljung

1980-01-01

411

Preparation and coercivity and saturation magnetization dependence of inductive heating property of Fe 3O 4 nanoparticles in an alternating current magnetic field for localized hyperthermia  

Microsoft Academic Search

The magnetite (Fe3O4) nanoparticles with different magnetic properties were prepared by coprecipitation of Fe3+ and Fe2+ with an aqueous NaOH solution. The inductive heating property of Fe3O4 nanoparticles in an alternating current (ac) magnetic field was investigated. The potential of Fe3O4 nanoparticles was evaluated for localized hyperthermia treatment of cancers. The maximum saturation magnetization Ms of Fe3O4 nanoparticles was 65.53emug?1,

Dong-Lin Zhao; Xian-Wei Zeng; Qi-Sheng Xia; Jin-Tian Tang

2009-01-01

412

Numerical analysis of the effect of local energy supply on the aerodynamic drag and heat transfer of a spherically blunted body in a supersonic air flow  

Microsoft Academic Search

The effect of local source of energy in a supersonic flow on the aerodynamic drag and heat transfer of a spherically blunted\\u000a body is studied numerically. Calculations are performed on the basis of the Navier-Stokes equations for a thermally equilibrium\\u000a model of air. Data on the effect of the intensity and size of the energy source on the wave drag,

V. A. Levin; V. G. Gromov; N. E. Afonina

2000-01-01

413

Effect of heat-treatment and defatting on the proximate composition of some Nigerian local soup thickeners  

Microsoft Academic Search

A comparative study of the effect of heat-treatment and defatting on the proximate composition of melon seeds (Colocynthis citrullus Linn.), dikanut seeds (Irvingia gabonensis) and cocoyam tuber (Colocasia esculenta), mostly used now as conventional soup thickeners in southern Nigeria, was carried out. There was generally no significant difference in proximate composition between raw and heat-processed samples at the 5% level

Eugene N. Onyeike; Tamunosiki Olungwe; Augustine A. Uwakwe

1995-01-01

414

New heat flow measurements in the Ulleung Basin, East Sea (Sea of Japan): relationship to local BSR depth,  

E-print Network

ORIGINAL New heat flow measurements in the Ulleung Basin, East Sea (Sea of Japan): relationship and southwestern sectors of the Ulleung Basin (East Sea or Sea of Japan) as part of regional gas hydrate research sea level, respectively. Introduction Seafloor heat flow measurements have made important

415

From local force-flux relationships to internal dissipations and their impact on heat engine performance: the illustrative case of a thermoelectric generator.  

PubMed

We present an in-depth analysis of the sometimes understated role of the principle of energy conservation in linear irreversible thermodynamics. Our case study is that of a thermoelectric generator (TEG), which is a heat engine of choice in irreversible thermodynamics, owing to the coupling between the electrical and heat fluxes. We show why Onsager's reciprocal relations must be considered locally and how internal dissipative processes emerge from the extension of these relations to a global scale: The linear behavior of a heat engine at the local scale is associated with a dissipation process that must partake in the global energy balance. We discuss the consequences of internal dissipations on the so-called efficiency at maximum power, in the light of our comparative analyses of exoreversibility and endoreversibility on the one hand and of two classes of heat engines, autonomous and periodically driven, on the other hand. Finally, basing our analysis on energy conservation, we also discuss recent works which claim the possibility to overcome the traditional boundaries on efficiency imposed by finite-time thermodynamics in thermoelectric systems with broken time-reversal symmetry; this we do by introducing a "thermal" thermopower and an "electrical" thermopower which permits an analysis of the thermoelectric response of the TEG considering a possible dissymmetry between the electrical/thermal and the thermal/electrical couplings. PMID:24032805

Apertet, Y; Ouerdane, H; Goupil, C; Lecoeur, Ph

2013-08-01

416

Localization of a yeast-phase-specific gene product to the cell wall in Histoplasma capsulatum.  

PubMed Central

A yeast-phase-specific gene, yps-3, has been identified in the virulent Histoplasma capsulatum strain, G217B. Although DNA sequencing of the genomic yps-3 gene from G217B failed to detect homologies with known proteins, the 5' end of a yps-3 cDNA contained a consensus signal sequence. A 519-bp fragment of the cDNA containing the translational stop codon was linker modified and inserted into the bacterial expression vector, pATH 1. Escherichia coli extracts containing the pATH 1 vector alone expressed a major 34-kDa TrpE polypeptide following induction with indoleacrylic acid, while the pATH 1/yps-3 construct produced a predominant 54-kDa TrpE/yps-3 fusion protein. Polyclonal rabbit sera directed against G217B reacted exclusively with the 54-kDa fusion protein in Western blots (immunoblots); serum samples from three patients with acute pulmonary or disseminated histoplasmosis were also positive. To localize the yps-3 protein within G217B, a monoclonal antibody (MAb 7.1) which recognized the yps-3 portion of the fusion protein was generated. A 17.4-kDa protein was detected with MAb 7.1 in Western blots prepared from cell wall fractions of G217B; cytoplasmic fractions were unreactive. No yps-3 antigen was detected in either fraction of the Downs strain, which fails to express the yps-3 gene. MAb 7.1 also detected a 17.4-kDa antigen in ethanol-precipitated culture supernatants derived from G217B. These findings localize the yps-3 gene product to the cell wall and culture supernatants, where the protein may influence the phase transition or the maintenance of the yeast state. PMID:8757832

Weaver, C H; Sheehan, K C; Keath, E J

1996-01-01

417

Salicylic acid alleviates adverse effects of heat stress on photosynthesis through changes in proline production and ethylene formation  

PubMed Central

We investigated the potential of salicylic acid (SA) in alleviating the adverse effects of heat stress on photosynthesis in wheat (Triticum aestivum L.) cv WH 711. Activity of ribulose 1,5-bisphosphate carboxylase (Rubisco), photosynthetic-nitrogen use efficiency (NUE), and net photosynthesis decreased in plants subjected to heat stress (40°C for 6 h), but proline metabolism increased. SA treatment (0.5 mM) alleviated heat stress by increasing proline production through the increase in ?-glutamyl kinase (GK) and decrease in proline oxidase (PROX) activity, resulting in promotion of osmotic potential and water potential necessary for maintaining photosynthetic activity. Together with this, SA treatment restricted the ethylene formation in heat-stressed plants to optimal range by inhibiting activity of 1-aminocyclopropane carboxylic acid (ACC) synthase (ACS). This resulted in improved proline metabolism, N assimilation and photosynthesis. The results suggest that SA interacts with proline metabolism and ethylene formation to alleviate the adverse effects of heat stress on photosynthesis in wheat. PMID:24022274

Khan, M Iqbal R; Iqbal, Noushina; Masood, Asim; Per, Tasir S; Khan, Nafees A

2013-01-01

418

Escherichia coli Heat Shock Protein DnaK: Production and Consequences in Terms of Monitoring Cooking  

PubMed Central

Through use of commercially available DnaK proteins and anti-DnaK monoclonal antibodies, a competitive enzyme-linked immunosorbent assay was developed to quantify this heat shock protein in Escherichia coli ATCC 25922 subjected to various heating regimens. For a given process lethality (F7010 of 1, 3, and 5 min), the intracellular concentration of DnaK in E. coli varied with the heating temperature (50 or 55°C). In fact, the highest DnaK concentrations were found after treatments at the lower temperature (50°C) applied for a longer time. Residual DnaK after heating was found to be necessary for cell recovery, and additional DnaK was produced during the recovery process. Overall, higher intracellular concentrations of DnaK tended to enhance cell resistance to a subsequent lethal stress. Indeed, E. coli cells that had undergone a sublethal heat shock (105 min at 55°C, F7010 = 3 min) accompanied by a 12-h recovery (containing 76,786 ± 25,230 molecules/cell) resisted better than exponentially growing cells (38,500 ± 6,056 molecules/cell) when later heated to 60°C for 50 min (F7010 = 5 min). Results reported here suggest that using stress protein to determine cell adaptation and survival, rather than cell counts alone, may lead to more efficient heat treatment. PMID:12788720

Seyer, Karine; Lessard, Martin; Piette, Gabriel; Lacroix, Monique; Saucier, Linda

2003-01-01

419

Off-design operation of ORC and CO 2 power production cycles for low temperature surplus heat recovery  

Microsoft Academic Search

In process industry, large amounts of surplus heat are available. Electricity production is an interesting method to recover this energy. This paper focuses on the off-design operation of the Rankine cycles and compares the behaviour of transcritical CO2<\\/sub> cycles and an organic Rankine cycle (ORC) with R-123 as the working fluid. The simulations show that the ORC is more sensitive

Harald Taxt Walnum; Yves Ladam; Petter Nekså; Trond Andresen

2011-01-01

420

On-line heat flux measurements improve the culture medium for the growth and productivity of genetically engineered CHO cells  

Microsoft Academic Search

With the increasingly competitive commercial production of target proteins by hybridoma and genetically engineered cells,\\u000a there is an urgent requirement for biosensors to monitor and control on-line and in real time the growth of cultured cells.\\u000a Since growth is accompanied by an enthalpy change, heat dissipation measured by calorimetry could act as an index for metabolic\\u000a flow rate. Recombinant CHO

Yue H. Guan; Richard B. Kemp

1999-01-01