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1

Heat recovery in thermoplastics production  

Microsoft Academic Search

An energy optimization of production of a thermoplastic material, polyamid-6, i.e. nylon-6, using boiler flue gases heat recovery is presented. Energy and environmental studies show an increase of process efficiency simultaneously with a decrease of thermal pollution. If the feed water is heated with flue gases, the fuel consumption is reduced by about 13%, while the boiler outlet flue gases

Alka Miheli?-Bogdani?; Rajka Budin

2002-01-01

2

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

3

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

4

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

5

DNA transformation via local heat shock  

NASA Astrophysics Data System (ADS)

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

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

2007-07-01

6

On the non-local heat kernel expansion  

NASA Astrophysics Data System (ADS)

We propose a novel derivation of the non-local heat kernel expansion, first studied by Barvinsky, Vilkovisky, and Avramidi, based on simple diagrammatic equations satisfied by the heat kernel. For Laplace-type differential operators, we obtain the explicit form of the non-local heat kernel form factors to second order in the curvatures. Our method can be generalized easily to the derivation of the non-local heat kernel expansion of a wide class of differential operators.

Codello, Alessandro; Zanusso, Omar

2013-01-01

7

Electricity and Heat Production Using Natural Gas.  

National Technical Information Service (NTIS)

The purpose of this report is to describe technique, production costs and competitiveness for the production of electricity and heat from natural gas. The report deals with the production of electricity using gas turbines, conventional power plants fuelle...

E. Hakkarainen B. Olsson M. Borchers

1987-01-01

8

Effect of local controlled heat on transdermal delivery of nicotine  

PubMed Central

Skin permeability and local blood perfusion are important factors for transdermal drug delivery. Application of heat is expected to enhance microcirculation and local perfusion and/or blood vessel permeability, thus facilitating drug transfer to the systemic circulation. In addition, heating prior to or during topical application of a drug may facilitate skin penetration, increase kinetic energy, and facilitate drug absorption. The aim of the present study was to investigate whether application of controlled local heat would enhance transdermal delivery from the nicotine patch mounted on the upper arm of ten healthy non-smoking male Caucasian subjects. Local skin perfusion was monitored using Laser Doppler Imaging (LDI) at baseline (32 C) and following application of local controlled heat (43 C) on the upper arm, where the patch was placed. The residue of the nicotine patches was then examined by High-Performance Liquid Chromatography (HPLC) to indicate the uptake of nicotine from the patch due to the local controlled heat. Controlled heat application (43C) caused significant cutaneous hyperaemia (up to 9 folds increase in skin perfusion) with an increase in nicotine uptake (up to 13 folds). The method was well tolerated without causing any pain or discomfort. These data suggest that controlled heat application, which is a simple, non-invasive method, can significantly enhance local skin perfusion and drug uptake from patches.

Petersen, Kristian Kjaer; Rousing, Mark Lillelund; Jensen, Carina; Arendt-Nielsen, Lars; Gazerani, Parisa

2011-01-01

9

PROTEIN INTAKE AND HEAT PRODUCTION1  

Microsoft Academic Search

During recent years the authors and their associates have conducted six experiments, five with growing and one with mature albino rats, for the purpose of determining the influence of the protein content of equicaloric diets on the heat production under conditions representing normal nutritive practice ; and in these experiments the heat production diminished, at moderate rates, in the increasing

ERNEST B. FORBES; RAYMOND W. SWIFT; LAWSON F. MARCY; MARY T. DAVENPORT

10

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

11

Local Lower Bounds on Heat Kernels.  

National Technical Information Service (NTIS)

We analyze convolution semigroups on a regular measure space which satisfies the local doubling property. We assume the kernels are bounded and symmetric with the characteristic small-time, volume-dependent, singularity. Then, using a weak conservation pr...

A. F. M. ter Elst D. W. Robinson

1997-01-01

12

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

13

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

14

Use of heat flux sensors for studying local heat transfer in pipes  

Microsoft Academic Search

Local heat transfer in the flow of air in a circular pipe 36 mm in diameter and 2000 mm in length was measured with single heat flux sensors and with a battery of such sensors. Data reveal an intensity of local heat transfer in the region of developed flow at Reynolds numbers in the range 10,000-120,000, length-to-diameter ratios above 50,

V. M. Legkii; O. A. Gerashchenko; V. D. Burlei

1978-01-01

15

How barn heating saves fuel, boosts productivity  

Microsoft Academic Search

L.B. White Co., a leading manufacturer of portable unvented propane barn heaters in Onalaska, Wis., recently published a booklet which demonstrates that barn heating can increase the production efficiency of farm animals and decrease the time required for preparing the animal for market during the winter months. In combination with proper ventilation, barn heating allows the farmer to cut his

de Tingo

1974-01-01

16

Universal constant for heat production in protists  

PubMed Central

Using a high sensitivity differential scanning calorimeter in isothermal mode, we directly measured heat production in eukaryotic protists from 5 phyla spanning over 5 orders of magnitude in carbon biomass and 8 orders of magnitude in cell volume. Our results reveal that metabolic heat production normalized to cell mass is virtually constant in these organisms, with a median of 0.037 pW pg C?1 (95% confidence interval = 0.0220.061 pW pg C?1) at 5 C. Contrary to allometric models, the relationship between heat production and cell carbon content or surface area is isometric (scaling exponents, 1.056 and 1.057, respectively). That heat production per unit cell surface area is constant suggests that heat flux through the cell surface is effectively instantaneous, and hence that cells are isothermal with their environment. The results further suggest that allometric models of metabolism based on metazoans are not applicable to protists, and that the underlying metabolic processes in the latter polyphyletic group are highly constrained by evolutionary selection. We propose that the evolutionary constraint leading to a universally constant heat production in single-celled eukaryotes is related to cytoplasmic packaging of organelles and surface area to volume relationships controlling diffusion of resources to these organelles.

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

2009-01-01

17

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

NASA Astrophysics Data System (ADS)

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

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

1990-04-01

18

Single thermal plume in locally heated vertical soap films  

NASA Astrophysics Data System (ADS)

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

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

2011-10-01

19

Single thermal plume in locally heated vertical soap films.  

PubMed

A vertical soap film is maintained by injection of a soap solution from the top. The film is then locally heated. Thermal plumes may be observed to rise in the film, depending on the magnitude of the heating and injected flows. The nearly two-dimensional nature of the system allows to visualize the motion of the plumes using an infrared camera. A model is proposed to describe the growth, emergence, and stationarity of the plumes in the film by taking into account both magnitudes of the heating ?T and injected flow Q. PMID:22181270

Adami, N; Dorbolo, S; Caps, H

2011-10-19

20

Electron heating and Landau damping in intense localized electric fields  

Microsoft Academic Search

A systematic kinetic-theory treatment of the interaction of electrons and ions with intense high-frequency localized electrostatic fields is formulated. A generalization of the familiar nonlinear Schroedinger equation includes nonlinear Landau-damping effects which prevent soliton collapse. An analytic calculation predicts a heated-electron distribution behaving asymptotically and modulated in the region near the localized field to form streamers in phase space.

B. Bezzerides; D. F. Dubois

1975-01-01

21

Heat production of nursery and growing piglets  

Technology Transfer Automated Retrieval System (TEKTRAN)

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

22

Radiogenic Heat Production in the Core?  

Microsoft Academic Search

Radiogenic heat production in the Earth is dominated by three elements: K, Th and U, which mainly reside in the Earth's mantle and crust. The global budget is determined from the fact that Th and U are both refractory. Thus, it is believed that the Th\\/U ratio of the bulk Earth must be identical to those of chondritic meteorites. In

M. Humayun

2003-01-01

23

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

PubMed

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

Ducharme, M B; Tikuisis, P

1994-05-01

24

Specific heat of a non-local attractive Hubbard model  

NASA Astrophysics Data System (ADS)

The specific heat C(T) of an attractive (interaction G<0) non-local Hubbard model is investigated within a two-pole approximation that leads to a set of correlation functions, which play an important role as a source of anomalies as the pseudogap. For a giving range of G and nT (where nT=n?+n?), the specific heat as a function of the temperature presents a two peak structure. Nevertehelesss, the presence of a pseudogap eliminates the two peak structure. The effects of the second nearest-neighbor hopping on C(T) are also investigated.

Calegari, E. J.; Lobo, C. O.; Magalhaes, S. G.; Chaves, C. M.; Troper, A.

2013-10-01

25

Investigation of local heat transfer coefficients in plate heat exchangers with temperature oscillation IR thermography and CFD  

Microsoft Academic Search

A method for the measurement of local convective heat transfer coefficients from the outside of a heat-transferring wall has been developed. This method is contact-free and fluid independent, employing radiant heating by laser or halogen spotlights and an IR camera for surface temperature measurements; it allows for the rapid evaluation of the heat transfer coefficient distribution of sizable heat exchanger

S. Freund; S. Kabelac

2010-01-01

26

Shear heating induced lithospheric localization: Does it result in subduction?  

NASA Astrophysics Data System (ADS)

Subduction is one of the main features of plate tectonics, yet it remains unclear how subduction started on Earth. Shear heating has been proposed to play an important role in i) creating deep focus as well as intermediate-depth earthquakes (Ogawa 1987) and ii) creating lithospheric-scale shear zones, thus creating a weak decoupling interface that enables subsequent subduction initiation. To understand the physics of this mechanisms, Kaus and Podladchikov (2006) conducted a scaling analysis for simplified viscoelastoplastic rheologies and found that the boundary between localization and no localization is quite sharp. Crameri and Kaus (2010) and Lu et al. (2011) extended this analysis to more realistic lithospheric setups and demonstrated that shear heating induced lithospheric-scale localization might occur for Earth-like parameters. It is however unclear if a lithospheric-scale shear zones on its own evolves into a subduction zone. Here, we use numerical models to adress the question of shear heating induced subduction initiation. In the framework of our models, we can identify four different regimes, of which two show subduction initiation. We then develop scaling laws that are able to predict the behaviour of our models, thus providing means to better understand the physics of shear heating induced subduction initiation. Our results suggest that shear heating induced subduction initiation is more likely to initate in a lithosphere consisting of dry olivine rather than wet olivine. A large plate age does not necessarily increase the potential for subduction initiation, as it increases the potential for convective instabilities to occur.

Thielmann, M.; Kaus, B. J. P.

2012-04-01

27

Thermal plumes in locally heated vertical soap films  

NASA Astrophysics Data System (ADS)

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

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

2012-02-01

28

One dimensional global and local solution for ICRF heating  

SciTech Connect

A numerical code GLOSI [Global and Local One-dimensional Solution for Ion cyclotron range of frequencies (ICRF) heating] is developed to solve one-dimensional wave equations resulting from the use of radio frequency (RF) waves to heat plasmas. The code uses a finite difference method. Due to its numerical stability, the code can be used to find both global and local solutions when imposed with appropriate boundary conditions. Three types of boundary conditions are introduced to describe wave scattering, antenna wave excitation, and fixed tangential wave magnetic field. The scattering boundary conditions are especially useful for local solutions. The antenna wave excitation boundary conditions can be used to excite fast and slow waves in a plasma. The tangential magnetic field boundary conditions are used to calculate impedance matrices, which describe plasma and antenna coupling and can be used by an antenna code to calculate antenna loading. These three types of boundary conditions can also be combined to describe various physical situations in RF plasma heating. The code also includes plasma thermal effects and calculates collisionless power absorption and kinetic energy flux. The plasma current density is approximated by a second-order Larmor radius expansion, which results in a sixth-order ordinary differential equation.

Wang, C.Y.; Batchelor, D.B.; Jaeger, E.F.; Carter, M.D.

1995-02-01

29

Constraints on Crustal Heat Production from Heat Flow Data  

NASA Astrophysics Data System (ADS)

The continental crust is an important repository of highly incompatible elements such as uranium and thorium. Exactly how much it contains is a key issue for the thermal regime of continents and for understanding how the Earth's mantle has evolved through geological time due to crust extraction. Recent estimates of the average uranium, thorium, and potassium concentrations in the continental crust vary by almost a factor of 2 (Wedepohl, 1995;Rudnick and Fountain, 1995; Taylor and McLennan, 1995; see also Chapter 3.01). These estimates are based on different assumptions regarding crustal structure and rely on different types of crustal samples, ranging from xenoliths to shales. They require an extrapolation in scale from tiny specimens to the whole crust of a geological province. Uranium and thorium tend to be located in accessory minerals and on grain boundaries, which are not related simply to bulk chemical composition. Thus, their concentrations vary on the scale of a petrological thin section, a hand sample, an outcrop, and a whole massif. In a geological province, abundant rocks such as gneisses and metasedimentary rocks are usually under-studied because of their complex origin and metamorphic history. A final difficulty is to evaluate the composition of intermediate and lower crustal levels, which are as heterogeneous as the shallow ones (e.g., Fountain and Salisbury, 1981; Clowes et al., 1992).Independent estimates of the amount of uranium and thorium in the continental crust can be obtained from heat flow data. The energy produced by the decay of these radioactive elements accounts for a large fraction of the heat flow at the surface of continents (Birch, 1954; Wasserburg et al., 1964; Clark and Ringwood, 1964; Sclater et al., 1980; Taylor and McLennan, 1995). This may be the only case where geophysical data bear directly on geochemical budgets. Since the mid-1970s, there has been much progress in our understanding of continental heat flow. The relationship between variations in heat flow and crustal heat production has been investigated systematically ( England et al., 1980; Jaupart, 1983a; Vasseur and Singh, 1986; Ketcham, 1996; Jaupart and Mareschal, 1999). Heat flow determinations on continents have been multiplied by almost a factor of 10 between the compilations by Jessop et al. (1976) and Pollack et al. (1993). Since the last compilation, a large number of high-quality data have been obtained for the poorly studied Precambrian Shield areas of Canada and India ( Mareschal et al., 2000a, b; Roy and Rao, 2000; Rolandone et al., 2002; Lewis et al., 2003).

Jaupart, C.; Mareschal, J.-C.

2003-12-01

30

Determinants of heat production in newborn lambs  

NASA Astrophysics Data System (ADS)

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

Eales, F. A.; Small, J.

1980-06-01

31

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

32

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

NASA Astrophysics Data System (ADS)

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

Grabenstein, V.; Kabelac, S.

2012-11-01

33

Modelling of hydrodynamics instabilities including the non local heat transport  

NASA Astrophysics Data System (ADS)

Experimental works [T. Sakaiya et al., Phys. Rev. Lett. 88, 145003 (2002)] have shown that the growth rate of ablative Rayleigh-Taylor instability is well reproduced by the simulation that solves the nonlocal heat transport. Furthermore, it has been recently pointed out [V. N. Goncharov et al., Phys. Plasmas 13, 012702 (2006)]that non local heat transport modifies characteristic lengths needed in hydrodynamic instabilities models. This work presents a new way to take into account the non local effects in hydrodynamic instabilities modelling. The simulations are performed with a code dedicated to the linear stability study of unsteady flows [M. Olazabal-Loum'e et al., J. Phys. IV France 133 (2006)]. The code calculates a one-dimensional basic solution and its first order 3D perturbation in Lagrangian formalism. It integrates a multidimensionnal non local model based on the approach of [J-F. Luciani et al., Phys. Rev. Lett. 51, 1664 (1983)] and [E. Epperlein et al., Phys. Fluids B 3, 3082 (1991)].

Olazabal-Loume, Marina; Feugeas, Jean-Luc; Nicolai, Philippe; Sanz, Javier

2007-11-01

34

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-Bttiker formula in the limit of vanishing coupling to local heat baths. We prove that the bath temperatures measure local kinetic energy and can, therefore, be interpreted as true atomic temperatures. In a setup where phonon reflections are eliminated, the Boltzmann transport equation under gray approximation with full phonon dispersion is shown to be equivalent to the self-consistent heat bath model. We also study thermal transport through two-dimensional constrictions in square lattice and graphene and discuss the differences between the exact solution and linear approximations.

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

2013-07-01

35

Energy conservation measures in buildings heated by district heating A local energy system perspective  

Microsoft Academic Search

The extensive energy use in the European building sector creates opportunities for implementing energy conservation measures (ECMs) in residential buildings. If ECM are implemented in buildings that are connected to a district heating (DH) system, the operation of DH plants may be affected, which in turn may change both revenue and electricity production in cogeneration plants. In this study a

Kristina Difs; Marcus Bennstam; Louise Trygg; Lena Nordenstam

2010-01-01

36

Proposed principles of maximum local entropy production.  

PubMed

Articles have appeared that rely on the application of some form of "maximum local entropy production principle" (MEPP). This is usually an optimization principle that is supposed to compensate for the lack of structural information and measurements about complex systems, even systems as complex and as little characterized as the whole biosphere or the atmosphere of the Earth or even of less known bodies in the solar system. We select a number of claims from a few well-known papers that advocate this principle and we show that they are in error with the help of simple examples of well-known chemical and physical systems. These erroneous interpretations can be attributed to ignoring well-established and verified theoretical results such as (1) entropy does not necessarily increase in nonisolated systems, such as "local" subsystems; (2) macroscopic systems, as described by classical physics, are in general intrinsically deterministic-there are no "choices" in their evolution to be selected by using supplementary principles; (3) macroscopic deterministic systems are predictable to the extent to which their state and structure is sufficiently well-known; usually they are not sufficiently known, and probabilistic methods need to be employed for their prediction; and (4) there is no causal relationship between the thermodynamic constraints and the kinetics of reaction systems. In conclusion, any predictions based on MEPP-like principles should not be considered scientifically founded. PMID:22746154

Ross, John; Corlan, Alexandru D; Mller, Stefan C

2012-06-29

37

Intelligent Control of Electrically Heated Micro Heat Exchanger with Locally Linear Neurofuzzy Identifier and Emotional Based Learning Controller  

Microsoft Academic Search

In this paper, an intelligent controller is applied to electrically heated micro heat exchanger. First, the dynamics of the micro heat exchanger is identified using Locally Linear Model Tree (LOLIMOT) algorithm. Then, an intelligent controller based on brain emotional learning algorithm is applied to the identified model. Modeling emotions has attracted much attention in recent years, both in cognitive psychology

Hossein Rouhani; Mahdi Jalili-Kharaajoo; Babak Nadjar Araabi; Caro Lucas

38

Homogeneous thermal cloak with constant conductivity and tunable heat localization.  

PubMed

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

39

Homogeneous Thermal Cloak with Constant Conductivity and Tunable Heat Localization  

NASA Astrophysics Data System (ADS)

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

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

2013-04-01

40

Human cyclophilin 40 is a heat shock protein that exhibits altered intracellular localization following heat shock  

PubMed Central

The unactivated steroid receptors are chaperoned into a conformation that is optimal for binding hormone by a number of heat shock proteins, including Hsp90, Hsp70, Hsp40, and the immunophilin, FKBP52 (Hsp56). Together with its partner cochaperones, cyclophilin 40 (CyP40) and FKBP51, FKBP52 belongs to a distinct group of structurally related immunophilins that modulate steroid receptor function through their association with Hsp90. Due to the structural similarity between the component immunophilins, FKBP52 and cyclophilin 40, we decided to investigate whether CyP40 is also a heat shock protein. Exposure of MCF-7 breast cancer cells to elevated temperatures (42C for 3 hours) resulted in a 75-fold increase in CyP40 mRNA levels, but no corresponding increase in CyP40 protein expression, even after 7 hours of heat stress. The use of cycloheximide to inhibit protein synthesis revealed that in comparison to MCF-7 cells cultured at 37C, those exposed to heat stress (42C for 3 hours) displayed an elevated rate of degradation of both CyP40 and FKBP52 proteins. Concomitantly, the half-life of the CyP40 protein was reduced from more than 24 hours to just over 8 hours following heat shock. As no alteration in CyP40 protein levels occurred in cells exposed to heat shock, an elevated rate of degradation would imply that CyP40 protein was synthesized at an increased rate, hence the designation of human CyP40 as a heat shock protein. Application of heat stress elicited a marked redistribution of CyP40 protein in MCF-7 cells from a predominantly nucleolar localization, with some nuclear and cytoplasmic staining, to a pattern characterized by a pronounced nuclear accumulation of CyP40, with no distinguishable nucleolar staining. This increase in nuclear CyP40 possibly resulted from a redistribution of cytoplasmic and nucleolar CyP40, as no net increase in CyP40 expression levels occurred in response to stress. Exposure of MCF-7 cells to actinomycin D for 4 hours resulted in the translocation of the nucleolar marker protein, B23, from the nucleolus, with only a small reduction in nucleolar CyP40 levels. Under normal growth conditions, MCF-7 cells exhibited an apparent colocalization of CyP40 and FKBP52 within the nucleolus.

Mark, Peter J.; Ward, Bryan K.; Kumar, Premlata; Lahooti, Hooshang; Minchin, Rodney F.; Ratajczak, Thomas

2001-01-01

41

Human cyclophilin 40 is a heat shock protein that exhibits altered intracellular localization following heat shock.  

PubMed

The unactivated steroid receptors are chaperoned into a conformation that is optimal for binding hormone by a number of heat shock proteins, including Hsp90, Hsp70, Hsp40, and the immunophilin, FKBP52 (Hsp56). Together with its partner cochaperones, cyclophilin 40 (CyP40) and FKBP51, FKBP52 belongs to a distinct group of structurally related immunophilins that modulate steroid receptor function through their association with Hsp90. Due to the structural similarity between the component immunophilins, FKBP52 and cyclophilin 40, we decided to investigate whether CyP40 is also a heat shock protein. Exposure of MCF-7 breast cancer cells to elevated temperatures (42 degrees C for 3 hours) resulted in a 75-fold increase in CyP40 mRNA levels, but no corresponding increase in CyP40 protein expression, even after 7 hours of heat stress. The use of cycloheximide to inhibit protein synthesis revealed that in comparison to MCF-7 cells cultured at 37 degrees C, those exposed to heat stress (42 degrees C for 3 hours) displayed an elevated rate of degradation of both CyP40 and FKBP52 proteins. Concomitantly, the half-life of the CyP40 protein was reduced from more than 24 hours to just over 8 hours following heat shock. As no alteration in CyP40 protein levels occurred in cells exposed to heat shock, an elevated rate of degradation would imply that CyP40 protein was synthesized at an increased rate, hence the designation of human CyP40 as a heat shock protein. Application of heat stress elicited a marked redistribution of CyP40 protein in MCF-7 cells from a predominantly nucleolar localization, with some nuclear and cytoplasmic staining, to a pattern characterized by a pronounced nuclear accumulation of CyP40, with no distinguishable nucleolar staining. This increase in nuclear CyP40 possibly resulted from a redistribution of cytoplasmic and nucleolar CyP40, as no net increase in CyP40 expression levels occurred in response to stress. Exposure of MCF-7 cells to actinomycin D for 4 hours resulted in the translocation of the nucleolar marker protein, B23, from the nucleolus, with only a small reduction in nucleolar CyP40 levels. Under normal growth conditions, MCF-7 cells exhibited an apparent colocalization of CyP40 and FKBP52 within the nucleolus. PMID:11525244

Mark, P J; Ward, B K; Kumar, P; Lahooti, H; Minchin, R F; Ratajczak, T

2001-01-01

42

Evaluation of Performance of Soft Heating Element for Local Hyperthermia  

Microsoft Academic Search

The soft heating method is an induction heating method utilizing temperature-sensitive magnetic materials implanted in the body. In this method, the Curie temperature is the reference temperature and the generation of heat is controlled automatically. In this paper, we evaluate the performance of three kinds of soft heating elements: a temperature-sensitive ferrite rod, which is a hybrid device, ferrite powders,

T. Yanada; H. Mastuki; T. Satoh; K. Murakami; S. Kikuchi; T. Hoshino

1991-01-01

43

Rural tourism and visitors' expenditures for local food products  

Microsoft Academic Search

Skuras D., Dimara E. and Petrou A (2006) Rural tourism and visitors' expenditures for local food products, Regional Studies40, 769779. European rural development policy has supported the production of local and regionally denominated food as a means to differentiate agricultural production, and rural tourism as a means to diversify rural employment. The aim of the present work is to address

Dimitris Skuras; Efthalia Dimara; Anastasia Petrou

2006-01-01

44

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

45

Adapting poultry production to solar heat  

SciTech Connect

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

Not Available

1982-12-15

46

Local Heating Effect of Flow Past a Circular Cylinder  

NASA Astrophysics Data System (ADS)

Heating effects of air flows past a two-dimensional circular cylinder at low Reynolds numbers and low Mach numbers are investigated by numerical simulation. The cylinder wall is heated partially rather than heated on the whole surface as with previous researches. The heating effects are completely different for various heating locations on the cylinder surface. Heating either windward or leeward side stabilizes the flow and reduces or completely suppresses vortex shedding from the cylinder at supercritical Reynolds numbers, which is consistent with previous results of heating on the whole surface of the cylinder. However, as the lateral sides of the cylinder (perpendicular to the stream-wise direction) are heated, an adverse effect is found for the first time in that the flow is destabilized and vortex shedding can be excited at subcritical Reynolds numbers. As the lateral sides of the cylinder are cooled, the flow is stabilized.

Xin, Xiao-Feng; Chen, Cheng; Wang, Bo-Fu; Ma, Dong-Jun; Sun, De-Jun

2010-04-01

47

Size spectra of heat production of microplankton of Sevastopol Bay  

Microsoft Academic Search

The object of this study is the heat production size spectra, i.e. the integral value of heat production over the size fractions (standard increments of logarithm of the particle size) of microplankton (organisms < 120 ?m). The particles of the sea water samples analyzed were separated and concentrated into fractions of different sizes by nylon nets, Sartorius membrane filters and

Alexander Lopukhin; Yury Kamenir

1995-01-01

48

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. The electroplated magnetic film was heated up using the induction heating, and leaded to solder reflow. It took only several seconds to complete the solder reflow and bonding process. The measurement results showed that the temperature of device region was only 110C during heating.

Hsueh-An Yang; Mingching Wu; Weileun Fang

2004-01-01

49

Adapting Poultry Production to Solar Heat.  

National Technical Information Service (NTIS)

During 1982 a floor heating system has been installed in a 40 ft. x 300 ft. chicken house (15,000 birds). The floor heating system consists of EPDM synthetic rubber tubing buried in a 4-inch concrete slab. Hot water is supplied to the tubing from a 4000 g...

1982-01-01

50

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

PubMed

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

Morriss, Gary P; Truant, Daniel P

2013-06-28

51

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

NASA Astrophysics Data System (ADS)

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 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 ?2?s 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.

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

2012-09-01

52

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

PubMed

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 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 ?2?s 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

2012-09-05

53

Marketing Locally Grown Food Products in Globally Branded Restaurants  

Microsoft Academic Search

This research study measures the perception patrons of a McDonald's restaurant for locally grown food products used in standard menu items. A survey questionnaire attempts to determine differences in consumer knowledge regarding the use of local Swiss food products and whether an increase in frequency of patronizing the restaurant will occur as a result of this program. The issue of

Michael Vieregge; Nancy Scanlon; James Huss

2007-01-01

54

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

55

Experiments on the local heat transfer characteristics of a circulating fluidized bed  

Microsoft Academic Search

The role of particle diameter in the heat transfer of a gassolid suspension to the walls of a circulating fluidized bed was studied for particles of uniform size. This work reports and analyzes new experimental results for the local bed to wall heat transfer coefficient, not including the radiation component, in a long active heat transfer surface length laboratory bed,

Josmar Davilson Pagliuso; Geraldo Lombardi; Leonardo Goldstein

2000-01-01

56

Calculation of Fission Product Decay Heat.  

National Technical Information Service (NTIS)

A method is described for calculating decay schemes for nuclei far from the line of beta stability. Results of calculations of the decay heat using these decay schemes are compared with experimental results. (Atomindex citation 09:368003)

P. Henningsen L. Mortensen

1977-01-01

57

Heat transfer during heat sterilization and cooling processes of canned products  

NASA Astrophysics Data System (ADS)

In this paper, an analysis of transient heat transfer during heat sterilization and cooling processes of a cylindrical canned product is presented. In the analysis, most practical case including the boundary condition of third kind (i.e., convection boundary condition, leading to 0.1 <= Bi <= 100) was employed. A simple analytical model for determining effective heat transfer coefficients for such products is developed. For the heat sterilization process, heating coefficient is incorporated into heat transfer coefficient model. An experimental study was performed to measure the thermal center temperatures of the short-cylindrical canned products (i.e., Tuna fish) during heat sterilization at the retort medium temperatures of 115?C and 121?C, and during cooling process at 16?C. The effective heat transfer coefficient model used the experimental temperature data. Using these effective heat transfer coefficients the center temperature distributions were calculated and compared with the experimental temperature distributions. Agreement was found considerably high. The results of the present study indicate that the heat-transfer analysis technique and heat-transfer coefficient model are reliable, and can provide accurate results for such problems.

Dincer, I.

58

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

59

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

PubMed Central

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

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

2012-01-01

60

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

Microsoft Academic Search

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

Hans Bjork; Anders Rasmuson

1999-01-01

61

Evaluation of Fission Product After-Heat.  

National Technical Information Service (NTIS)

Reported here are studies on: estimation of fission-product gamma spectra; comparisons of theoretical predictions of fission-product decay power with ongoing experimental programs; and a protocol for estimating bias in decay energy estimates for fission p...

B. I. Spinrad

1976-01-01

62

Indigenous algae for local bioresource production: Phycoprospecting  

Microsoft Academic Search

Photosynthetic algae represent a large and diverse group of organisms that have only a limited history of characterization and exploitation. The application of resource production from algae is relatively untapped, with the potential to produce fuels, food, fibers and nutraceuticals on a large scale. Methods to screen for indigenous species of algae have improved and can allow communities to prospect

Ann C. Wilkie; Scott J. Edmundson; James G. Duncan

63

Latent heat thermal energy storage for lunar oxygen production  

SciTech Connect

A necessary component of a solar-based lunar oxygen production system is a thermal energy storage module. We discuss some of the heat transfer and phase change problems associated with the design and operation of such a module based on the latent heat of melting of lunar rock. 12 refs.

Solomon, A.D. [Solomon (A.D.), Omer (Israel); Alexiades, V.; Jacobs, G.; Naney, M.; Olszewski, M. [Oak Ridge National Lab., TN (United States)

1992-08-01

64

Latent heat thermal energy storage for lunar oxygen production  

SciTech Connect

A necessary component of a solar-based lunar oxygen production system is a thermal energy storage module. We discuss some of the heat transfer and phase change problems associated with the design and operation of such a module based on the latent heat of melting of lunar rock. 12 refs.

Solomon, A.D. (Solomon (A.D.), Omer (Israel)); Alexiades, V.; Jacobs, G.; Naney, M.; Olszewski, M. (Oak Ridge National Lab., TN (United States))

1992-01-01

65

Extraction of Natural Products Using Microwaves as a Heat Source  

Microsoft Academic Search

Microwave-assisted extraction is the process of using microwave energy to heat the moisture present in the plant material or solvents in contact in order to extract natural products from the plant materials. A typical microwave-assisted extraction is completed within few minutes with higher yield and less solvent consumption. This review gives a brief theoretical background of microwave heating along with

Meghal Desai; Jigisha Parikh; P. A. Parikh

2010-01-01

66

Intermittency and local heating in the solar wind.  

PubMed

Evidence for nonuniform heating in the solar wind plasma near current sheets dynamically generated by magnetohydrodynamic (MHD) turbulence is obtained using measurements from the ACE spacecraft. These coherent structures only constitute 19% of the data, but contribute 50% of the total plasma internal energy. Intermittent heating manifests as elevations in proton temperature near current sheets, resulting in regional heating and temperature enhancements extending over several hours. The number density of non-Gaussian structures is found to be proportional to the mean proton temperature and solar wind speed. These results suggest magnetofluid turbulence drives intermittent dissipation through a hierarchy of coherent structures, which collectively could be a significant source of coronal and solar wind heating. PMID:23004953

Osman, K T; Matthaeus, W H; Wan, M; Rappazzo, A F

2012-06-26

67

Thermoregulatory and Nonthermoregulatory Heat Production in Burned Rat.  

National Technical Information Service (NTIS)

Severely burned patients are hypermetabolic within their thermoneutral zone (TNZ), where there are no thermoregulatory demands on heat production. The rat has been used as a model of postburn hypermetabolism without clear evidence that it behaves in a sim...

D. R. Strome L. H. Aulick A. D. Mason B. A. Pruitt

1986-01-01

68

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

Microsoft Academic Search

Concentrations of heat producing elements (Th, U, and K) in 58 samples representative of the main lithologies in a 100-km transect of the Superior Province of the Canadian Shield have been obtained. The relatively large variation in heat production found among the silicic plutonic rocks is shown to correlate with modal abundances of accessory minerals, and these variations are interpreted

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

1987-01-01

69

Effect of Heating Treatments, Processing Methods and Refrigerated Storage of Milk and Some Dairy Products on Lipids Oxidation  

Microsoft Academic Search

The effect of heating treatments (pasteurization and boiling), micro waving, processing steps and storage of milk and some locally produced dairy products (Brined white cheese (Nabulsi), Yogurt and Labaneh on chemical changes of milk lipids were evaluated. The Peroxide value (POV) p-anisidine value (p-AV), thiobarbituric acid (TBA), free fatty acid and totox were determined. The heating treatments of milk do

2008-01-01

70

Heat transfer to a transition-range gas flow in a pipe at high heat fluxes; Effect of buoyancy on local heat transfer in forced turbulent flow  

Microsoft Academic Search

Experimental data on the local coefficient of heat transfer in pipe flow of gas in the laminar to turbulent transition range are presented. The experiments were performed at elevated pressure, so that free convection exerted a significant effect on the forced turbulent flow (the free and forced convection acted in the same direction). Under these conditions the coefficient of heat

P. S. Poskas; V. E. Kaupas; J. V. Vilemas

1989-01-01

71

Heat Pipe Solar Receiver for Oxygen Production of Lunar Regolith  

NASA Astrophysics Data System (ADS)

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

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

2009-03-01

72

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

Federal Register 2010, 2011, 2012, 2013

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

2012-07-05

73

Effects of electron beam local post-weld heat-treatment on the microstructure and properties of 30CrMnSiNi2A steel welded joints  

Microsoft Academic Search

To improve the microstructure and properties of electron beam welded joints, vacuum or furnace whole post-weld heat-treatment (FWPWHT) should usually be carried out. Electron beam local post-weld heat-treatment (EBLPWHT) is a quite new heat-treatment procedure that provides the advantages of high precision, flexibility and efficiency, energy saving, and higher productivity. In this paper, the microstructure, mechanical properties, fracture toughness and

F. R. Chen; L. X. Huo; Y. F. Zhang; L. Zhang; F. J. Liu; G. Chen

2002-01-01

74

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

75

Studies of full-coverage film cooling. II - Measurement of local heat transfer coefficient  

NASA Astrophysics Data System (ADS)

The local heat transfer coefficient of full-coverage film-cooled wall has been measured by using the law of analogy to mass transfer. For this experiment, the technique of sublimation of naphthalene was used. From these experiments, the effects of the mass flux ratio and nondimensional injection wall temperature ratio on the local Stanton number are made clear and it is confirmed experimentally that the local Stanton number is a linear function of nondimensional temperature ratio as expected from the analysis. Furthermore, the local heat transfer coefficient on the backside surface has been obtained and a technique for the improvement of cooling effectiveness is discussed.

Kumada, M.; Hirata, M.; Kasagi, N.

1981-03-01

76

Sweat gland response to local heating during sleep in man.  

PubMed

In order to assess whether the fluctuations in the sweating response occurring during sleep are related to changes in central drive or in peripheral sweat gland reactivity, 4 healthy male subjects spent 6 non-consecutive nights in a climatic chamber. Air temperature was 25 degrees C, dew-point temperature was 10 degrees C and air velocity was 0.3 m X s-1, while wall temperature was either 38 degrees C, 46 degrees C or 48.7 degrees C giving 3 levels of operative temperature (To = 30, 33 or 34 degrees C). During the whole night, 2 local sweating rates on the right and the left sides of the upper chest were continuously recorded from 12 cm2 area capsules using a dew-point hygrometer technique, while applying local thermal clamps, a constant 2 degrees C difference in local skin temperatures being imposed between the two symmetrical skin areas. Continuous measurements were made of rectal temperature, 10 local skin temperatures, 2 EEGs, 2 EOGs, 1 EMG and 1 ECG. Results show that the multiplicative relationship between the peripheral influence of local skin temperature and the central drive for sweating described in waking subjects, is still valid in sleeping subjects. No peripheral change appears in sweat gland reactivity between the different sleep stages. Changes in the sensitivity of the thermoregulatory system occurring during sleep cannot be explained by a local factor acting at the sweat gland level. PMID:3795118

Amoros, C; Sagot, J C; Libert, J P; Candas, V

1986-01-01

77

The mesoscale responses of a locally heated planetary boundary layer  

Microsoft Academic Search

The steady boundary layer responses that occur over the Great Lakes region during wintertime cold air outbreaks are examined using a 2-D, linear, analytic model. The boundary layer is modeled as an idealized, constantly stratified, viscous, rotating Boussinesq fluid that move uniformly between two horizontally infinite, rigid, stress free plates. The heat from the lakes is parameterized in terms of

Peter John Sousounis

1990-01-01

78

Effect of local heat supply to a turbulent boundary layer on the friction  

Microsoft Academic Search

The results of calculating a supersonic turbulent boundary layer on a flat plate in the presence of thermal energy supply\\u000a to the boundary layer are presented. Two methods of energy supply are considered: heating a local interval of the surface,\\u000a which is otherwise thermally insulated and using a local volume heat source. It is shown that for the same amount

A. V. Kazakov; M. N. Kogan; A. P. Kuryachii

1997-01-01

79

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

Microsoft Academic Search

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

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

1987-01-01

80

Low-power nuclear engineering for heat production  

NASA Astrophysics Data System (ADS)

The paper shows the expediency and importance of the development of low-power nuclear engineering as well as feasibility indices of an up-to-date nuclear power plant intended for regional energy production. A high reliability of the vessel-type boiling reactor with a natural coolant circulation is shown under various operating conditions of a nuclear heat production plant.

Kursky, A. S.; Kalygin, V. V.; Semidotsky, I. I.

2012-05-01

81

Experimental study of local natural convection heat transfer in inclined and rotating enclosures  

SciTech Connect

The local and mean natural-convection heat-transfer characteristics were studied experimentally in an air-filled differentially heated enclosure with cross-sectional aspect-ratio one. A Mach-Zehnder interferometer was employed to reveal the entire temperature field, which enables the measurement of the local and mean Nusselt numbers at the hot and cold surfaces. The first part of this investigation was a study of the inclination effect on the flow and heat-transfer behaviors. The measurements of local and mean Nusselt numbers are obtained at various inclination angles, ranging between 0/sup 0/ (heated from above) and 180/sup 0/. (Benard convection, heated from below), for Rayleigh numbers between 10/sup 4/ and 10/sup 6/. The measured heat flux at the hot and cold boundaries showed a strong dependence on the angle of inclination and Rayleigh number. In the second part, the study is extended to include the effect of combined heating and rotation on the thermal and hydrodynamic boundary layers. The enclosure is rotated about its longitudinal horizontal axis. Experimental results showed how the centrifugal and Coriolis forces arising from rotation have remarkably influenced the local heat transfer behavior when compared with the non-rotating results.

Hamady, F.J.

1987-01-01

82

Local thermal equilibrium for transient heat conduction: theory and comparison with numerical experiments  

Microsoft Academic Search

Local thermal equilibrium refers to the state in which a single temperature can be used to describe a heat transfer process in a multiphase system. When this condition occurs, a one-equation model can be used and the analysis of the heat transfer process is greatly simplified. In this paper we first develop the constraints that must be satisfied in order

Stephen Whitaker

1995-01-01

83

Intracellular localization of Xenopus small heat shock protein, hsp30, in A6 kidney epithelial cells  

Microsoft Academic Search

Small heat shock proteins (shsps) are molecular chaperones that are inducible by environmental stress. In this study, immunocytochemical analysis and laser scanning confocal microscopy revealed that the shsp family, hsp30, was localized primarily in the cytoplasm of Xenopus A6 kidney epithelial cells after heat shock or sodium arsenite treatment. Heat shock-induced hsp30 was enriched in the perinuclear region with some

Mekonnen Gellalchew; John J. Heikkila

2005-01-01

84

Microchannel size effects on local flow boiling heat transfer to a dielectric fluid  

Microsoft Academic Search

Heat transfer with liquidvapor phase change in microchannels can support very high heat fluxes for use in applications such as the thermal management of high-performance electronics. However, the effects of channel cross-sectional dimensions on the two-phase heat transfer coefficient and pressure drop have not been investigated extensively. In the present work, experiments are conducted to investigate the local flow boiling

Tannaz Harirchian; Suresh V. Garimella

2008-01-01

85

Formation of Silicon-Gold Eutectic Bond Using Localized Heating Method  

Microsoft Academic Search

A new bonding technique is proposed by using localized heating to supplythe bonding energy.Heating is achieved by applying a dc current through micromachined heaters made of gold which serves as both the heating and bonding material.At the interface of silicon and gold, the formation of eutectic bond takes place in about 5 minutes.Assembly of two substrates in microfabrication processescan be

Liwei Lin; Yu-Ting Cheng; Khalil Najafi

1998-01-01

86

Evidence for localized cell heating induced by infrared optical tweezers  

Microsoft Academic Search

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 1.45±0.15 °C\\/100 mW

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

1995-01-01

87

Evaluation of Fission Product After-Heat.  

National Technical Information Service (NTIS)

Reported here is work for the period indicated under the subject contract. Specific tasks covered in this report are: (1) Neutron capture in fission products, with the preliminary result that this effect does not lead to a major change in decay power of r...

B. I. Spinrad

1976-01-01

88

Enthalphyand Heat Capacity of Several Candy Products.  

National Technical Information Service (NTIS)

Neither in the Soviet nor in the foreign literature are there at the present sufficient data on the thermophysical properties of candy products. The lack of such data makes it impossible to carry out thermal and technological computations with a sufficien...

A. Kovalev I. Perelshtein

1972-01-01

89

An experimental method to measure local heat transfer coefficient from a distance  

NASA Astrophysics Data System (ADS)

The present paper describes an experimental method to measure local heat flux from a distance. The method is based on the fact that when a wall is heated locally, the wall temperature rise depends on the local heat transfer coefficient at that point. In the experiment, the wall was heated by a power laser and the temperature rise was measured by an infrared spot thermometer. Transient heat conduction in a wall was numerically solved for a heated location. The integral of the temperature rise is found to be the quantity most sensitive to variation in heat transfer coefficient. If the integral value is measured within a 2 percent error margin, the heat transfer coefficient could be evaluated within a margin of 10 percent for acryl. For metals having high thermal diffusivity, however, error is above 80 percent. Automatical measurement with the aid of a personal computer made it possible to evaluate forced convection heat transfer coefficient of a flat plaster plate within an accuracy of 20 percent.

Fujii, Motoo; Mugabi, Nelson; Yoshikawa, Chouiku; Fujii, Tetsu

90

Heat Loss ResponseInducedby Local Heating of Spinal Cord with Argon Laser  

Microsoft Academic Search

The parts of spinalcord were locallyheated with an argonlaser in order to inducethe heat loss responsesin rabbits.Andthe spinalcordtouchedwitha guide tube for a glass fiber (0.4mm in diameter)was heated by the argon laser irradiationinside the guide tube. This localheatingmethodis possibleselectivelyto heat a part of spinal cord within length of implantedguide tube. The guide tube was implantedinto the periduralspace fromlumbarvertebrae(L4\\/L5)to thoracicvertebra(Th7)of the

Nobu OHWATARI; Mitsuo KOSAKA

91

Thermal-Electrical FEA of Localized Heating for MEMS Packaging.  

National Technical Information Service (NTIS)

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

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

2006-01-01

92

Rubisco activase and wheat productivity under heat-stress conditions.  

PubMed

Rubisco activase (RCA) constrains the photosynthetic potential of plants at high temperatures (heat stress). Endogenous levels of RCA could serve as an important determinant of plant productivity under heat-stress conditions. Thus, in this study, the possible relationship between expression levels of RCA and plant yield in 11 European cultivars of winter wheat following prolonged exposure to heat stress was investigated. In addition, the effect of a short-term heat stress on RCA expression in four genotypes of wheat, five genotypes of maize, and one genotype of Arabidopsis thaliana was examined. Immunoblots prepared from leaf protein extracts from control plants showed three RCA cross-reacting bands in wheat and two RCA cross-reacting bands in maize and Arabidopsis. The molecular mass of the observed bands was in the range between 40 kDa and 46 kDa. Heat stress affected RCA expression in a few genotypes of wheat and maize but not in Arabidopsis. In wheat, heat stress slightly modulated the relative amounts of RCA in some cultivars. In maize, heat stress did not seem to affect the existing RCA isoforms (40 kDa and 43 kDa) but induced the accumulation of a new putative RCA of 45-46 kDa. The new putative 45-46 kDa RCA was not seen in a genotype of maize (ZPL 389) that has been shown to display an exceptional sensitivity to heat stress. A significant, positive, linear correlation was found between the expression of wheat 45-46 kDa RCA and plant productivity under heat-stress conditions. Results support the hypothesis that endogenous levels of RCA could play an important role in plant productivity under supraoptimal temperature conditions. PMID:19671572

Ristic, Zoran; Momcilovic, Ivana; Bukovnik, Urska; Prasad, P V Vara; Fu, Jianming; Deridder, Benjamin P; Elthon, Thomas E; Mladenov, Novica

2009-08-11

93

LOCAL THEORY IN CRITICAL SPACES FOR COMPRESSIBLE VISCOUS AND HEAT-CONDUCTIVE GASES  

Microsoft Academic Search

We are concerned with local existence and uniqueness of solutions for a general model of viscous and heat-conductive gases with low regularity assumptions on the initial data (the velocity and the temperature may be discontinuous). Local well-posedness is showed to hold in spaces which are critical with respect to the scaling of the equations, provided that the initial density is

Raphal Danchin

2001-01-01

94

Evidence for localized cell heating induced by infrared optical tweezers  

SciTech Connect

The confinement of liposomes and Chinese hamster ovary (CHO) cells by infrared (IR) optical tweezers is shown to result in sample heating and temperature increases by several degrees centigrade, as measured by a noninvasive, spatially resolved fluorescence detection technique. For micron-sized spherical liposome vesicles having bilayer membranes composed of the phospholipid 1,2-diacyl-pentadecanoyl-glycero-phosphocholine (15-OPC), a temperature rise of {similar_to}1.45{plus_minus}0.15 {degree}C/100 mW is observed when the vesicles are held stationary with a 1.064 {mu}m optical tweezers having a power density of {similar_to}10{sup 7} W/cm{sup 2} and a focused spot size of {similar_to}0.8 {mu}m. The increase in sample temperature is found to scale linearly with applied optical power in the 40 to 250 mW range. Under the same trapping conditions, CHO cells exhibit an average temperature rise of nearly 1.15{plus_minus}0.25 {degree}C/100 mW. The extent of cell heating induced by infrared tweezers confinement can be described by a heat conduction model that accounts for the absorption of infrared (IR) laser radiation in the aqueous cell core and membrane regions, respectively. The observed results are relevant to the assessment of the noninvasive nature of infrared trapping beams in micromanipulation applications and cell physiological studies. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.

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

1995-05-01

95

Heat and fission product transport in molten core material pool with crust  

Microsoft Academic Search

Heat transfer and fluid flow in a molten pool are influenced by internal volumetric heat generated from the radioactive decay of fission product species retained in the reactor vessel during a severe accident. The pool superheat is determined based on the overall energy balance that equates the heat production rate to the heat loss rate. Decay heat of fission products

J. I. Yun; K. Y. Suh; C. S. Kang

2005-01-01

96

Heat production during contraction in skeletal muscle of hypothyroid mice  

SciTech Connect

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

Leijendekker, W.J.; van Hardeveld, C.; Elzinga, G. (Free Univ., Amsterdam (Netherlands))

1987-08-01

97

Ohmic heated sheet for the Ca ion beam production  

SciTech Connect

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

Efremov, A.; Bogomolov, S.; Kazarinov, N.; Kochagov, O.; Loginov, V. [Joint Institute for Nuclear Research, Dubna, Moscow 141980 (Russian Federation)

2008-02-15

98

Tissue localization of maize acetylcholinesterase associated with heat tolerance in plants  

PubMed Central

Our recent study reported that maize acetylcholinesterase (AChE) activity in the coleoptile node is enhanced through a post-translational modification response to heat stress and transgenic plants overexpressing maize AChE gene had an elevated heat tolerance, which strongly suggests that maize AChE plays a positive, important role in maize heat tolerance. Here we present (1) maize AChE activity in the mesocotyl also enhances during heat stress and (2) maize AChE mainly localizes in vascular bundles including endodermis and epidermis in coleoptile nodes and mesocotyls of maize seedlings.

Yamamoto, Kosuke; Momonoki, Yoshie S.

2012-01-01

99

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...

100

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

101

Vortices in a cylindrical annulus nonhomogeneously heated: effect of localized heating on their stability and intensity.  

PubMed

In this paper we study the influence of localized or widespread nonhomogeneous temperature profiles on the stability and intensity of vertical vortices generated in a cylindrical annulus by a convective instability. Localized profiles lead to more stable vortices while widespread inhomogeneities intensify the spin motion around the inner cylinder. PMID:22060538

Navarro, M C; Herrero, H

2011-09-07

102

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

NASA Astrophysics Data System (ADS)

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

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

103

Maintaining health, comfort and productivity in heat waves  

PubMed Central

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

Parsons, Ken

2009-01-01

104

ADOPTING PERSONNEL PRODUCTIVITY INNOVATIONS IN AMERICAN LOCAL GOVERNMENTS  

Microsoft Academic Search

Improving the productivity of public employees has increasingly attracted the attention of urban policymakers and administrators concerned about the quality, cost, and efficiency of governmental service delivery. A national survey of local personnel managers was undertaken to ascertain the degree of jurisdictional receptivity to personnel-based management tools, preferred approaches, and the most serious policy and institutional barriers to the implementation

Charles E. Davis; Jonathan P. West

1985-01-01

105

Language production: electroencephalographic localization in the normal human brain.  

PubMed

Slow negative potentials, which are at a maximum over Broca's area in the left hemisphere, were recorded when normnal subjects spontaneously produced polysyllabic words. Bilaterally symmetrical potentials were seen with analogous, nonspeech control gestures. These potentials began up to 1 second before word or gesture articulation. These results are the first demonstration of localization of language production in normal human brain. PMID:5550508

McAdam, D W; Whitaker, H A

1971-04-30

106

Language Production: Electroencephalographic Localization in the Normal Human Brain  

Microsoft Academic Search

Slow negative potentials, which are at a maximum over Broca's area in the left hemisphere, were recorded when normal subjects spontaneously produced polysyllabic words. Bilaterally symmetrical potentials were seen with analogous, nonspeech control gestures. These potentials began up to 1 second before word or gesture articulation. These results are the first demonstration of localization of language production in normal human

Dale W. McAdam; Harry A. Whitaker

1971-01-01

107

Naming Products in China: Local or Foreign Branding  

Microsoft Academic Search

As China's entry into the WTO is imminent and more multinational corporations (MNCs) enter and expand in the Chinese market, the issue of how to name the brand of a product in the largest developing country market becomes a frequently asked question. Should MNCs adopt a locally meaningful brand or one that sounds like the original brand name of the

Zhan G. Li; L. William Murray

2002-01-01

108

Multisensor Based Indoor Vehicle Localization System for Production and Logistic  

Microsoft Academic Search

In this paper a multisensor based indoor vehicle localization system for production and logistics is introduced. To track the position and the orientation of a moving vehicle a set of distance values to several points on the vehicle is measured by a wireless ranging system. The beacons of the wireless system are mounted at known positions in the surrounding infrastructure.

J. C. Fuentes Michel; Mark Christmann; Michael Fiegert; Peter Gulden; Martin Vossiek

2006-01-01

109

Productivity spillovers from competition between local firms and foreign affiliates  

Microsoft Academic Search

Using detailed (unpublished) industry data from Mexican manufacturing, this paper estimates a simple simultaneous model to examine if there are signs of productivity spillovers from competition between local firms and foreign affiliates. The results are affirmative, but only when suspected 'enclave' industries are dropped from the sample. The spillovers from competition are not determined by foreign presence alone, but rather

Ari Kokko

1996-01-01

110

Production of high-energy chemicals using solar energy heat  

Microsoft Academic Search

Techno-economic studies and thermodynamic assessments of chemical reactions and processes were made and the market potentials for major chemical commodities that use significant amounts of fossil resources were determined in order to identify energy-intensive processes that would be suitable for the production of chemicals and fuels using solar energy process heat. Of particular importance was the comparison of relative costs

J. R. Dafler; J. Sinnott; M. Novil; B. D. Yudow; M. G. Rackoff

1978-01-01

111

Arc heater nozzle heating test with hydrogen combustion products  

Microsoft Academic Search

A single-edge expansion test nozzle was tested to obtain hypersonic vehicle flight-level nozzle heating data with simulated hydrogen combustion products. The test objectives were to extend the database for nozzle design and computer code validation, and also to analyze flow patterns using oil flow visualizations. A total of 34 runs were made for 15 and 25 degree nozzle ramp angles

Bernard S. C. Kim; Stanley L. Stoy; Herschel J. Fivel

1991-01-01

112

Effects of Progesterone on the Autonomic Heat Production  

Microsoft Academic Search

posterior hypothalamus and ventromedial nucleus, respectively. These signals were inhibited by signals in the preoptic area of the hypothalamus. When the temperature in the preoptic area rose, both heat productions were inhibited. We made a simple model consisting of an amplifier with a threshold. The step response of the model simulated closely the actual thermoregulatory responses against a cold load.

Takayoshi Hosono; Kazuyuki Kanosue; Kenzo Akazawa; Koichi Umimoto

113

Lethal effects of heat and use of localized heat treatment for control of bed bug infestations.  

PubMed

Bed bugs, Cimex lectularius L., hide in cracks and crevices in furniture and are difficult to control. The bed bug thermal death kinetics were examined to develop a heat treatment method to eliminate bed bug infestations in room contents. High temperatures caused temporary immobilization (knockdown) of bed bugs even with exposures that did not have lethal effects. Exposure of bed bug adults to 39 degrees C for 240 min caused no mortality; however, as temperatures increased from 41 to 49 degrees C, exposure times that caused 100% mortality decreased. The temperature difference to provide a 10-fold change in the mortality was estimated at 4 degrees C, and the estimated activation energy (EA) was between 484 and 488.3 kJ/mol. This demonstrates that bed bugs are not more resistant or susceptible to changes in temperature than other tested insects and that the temperatures needed to kill bed bugs are relatively low. In room treatment tests, heat treatment times varied from 2 to 7 h with complete mortality of exposed bed bugs within the treatment envelope created by surrounding the treated furniture with polystyrene sheathing boards. Containment and circulation of heat around the treated material were crucial factors in an efficient heat treatment for bed bug control. The room floor material greatly affected containment of the heat. The tested method for limited heat treatment of furniture and other room contents required equipment costing less than US$400 and provided opportunity for residual pesticide application around the room with minimal disruption in use of treated room. PMID:19610436

Pereira, Roberto M; Koehler, Philip G; Pfiester, Margie; Walker, Wayne

2009-06-01

114

Local heat transfer augmentation in channels with two opposite ribbed surfaces  

NASA Astrophysics Data System (ADS)

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.

115

The local heat transfer mathematical model between vibrated fluidized beds and horizontal tubes  

SciTech Connect

A dimensionless mathematical model is proposed to predict the local heat transfer coefficients between vibrated fluidized beds and immersed horizontal tubes, and the effects of the thickness of gas film and the contact time of particle packets are well considered. Experiments using the glass beads (the average diameter bar d{sub p}=1.83mm) were conducted in a two-dimensional vibrated fluidized bed (240 mm x 80 mm). The local heat transfer law between vibrated fluidized bed and horizontal tube surface has been investigated. The results show that the values of theoretical prediction are in good agreement with experimental data, so the model is able to predict the local heat transfer coefficients between vibrated fluidized beds and immersed horizontal tubes reasonably well, and the error is in range of {+-}15%. The results can provide references for future designing and researching on the vibrated fluidized beds with immersed horizontal tubes. (author)

Zhu, Xuejun [School of Chemical Engineering, Sichuan University, Chengdu 610065 (China); College of Biology and Chemical Engineering, Panzhihua University, Panzhihua 617000 (China); Ye, Shichao; Pan, Xiaoheng [School of Chemical Engineering, Sichuan University, Chengdu 610065 (China)

2008-05-15

116

Local thermal heating in VO2 electric-field-induced metal insulator transition  

NASA Astrophysics Data System (ADS)

Over recent years, the insulator to metal transition (IMT) of the vanadium dioxide (VO2) Mott insulator has been revisited revealing an electric-field-induced resistance switching. Whether this feature is purely due to an electrical field effect or due to some Joule heating is still under debate. Here we report a local temperature measurement in a 10?m and a 20?m VO2 junction while going through the resistance switching. The sample was placed at ?T=15K below 340K (the thermally induced insulator to metal transition). When ramping up the voltage across the junction we find that the local heating inside the VO2 junction is close to 15K. This data suggests that in these temperature, current and voltage ranges, the field induced IMT can be explained by local Joule heating. Work supported by the French ANR-09-BLAN-0388-01 and the US DOE and AFOSR.

Zimmers, A.; Aigouy, L.; Sharoni, A.; Wang, S.; Ramirez, J. G.; Schuller, I. K.

2012-02-01

117

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

PubMed Central

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

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

2005-01-01

118

Differential heat shock protein localization in chronic lymphocytic leukemia  

PubMed Central

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

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

2010-01-01

119

Hydrogen production from nuclear fission product waste heat and use in gas turbines  

Microsoft Academic Search

An analysis has been made on the feasibility of producing hydrogen using fission product waste heat and its subsequent combustion in gas turbines. The work has been performed in three distinct phases. In the first phase, a system using radioactive waste heat has been designed, which produces electricity. The electrical power output of this system has been calculated as a

M. E. Nelson; E. L. Keating; D. R. Govan; R. J. Banchak; J. R. Corpus

1979-01-01

120

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

121

Elevated local skin temperature impairs cutaneous vasoconstrictor responses to a simulated haemorrhagic challenge while heat stressed.  

PubMed

During a simulated haemorrhagic challenge, syncopal symptoms develop sooner when individuals are hyperthermic relative to normothermic. This is due, in part, to a large displacement of blood to the cutaneous circulation during hyperthermia, coupled with inadequate cutaneous vasoconstriction during the hypotensive challenge. The influence of local skin temperature on these cutaneous vasoconstrictor responses is unclear. This project tested the hypothesis that local skin temperature modulates cutaneous vasoconstriction during simulated haemorrhage in hyperthermic humans. Eight healthy participants (four men and four women; 32 7 years old; 75.2 10.8 kg) underwent lower-body negative pressure to presyncope while heat stressed via a water-perfused suit sufficiently to increase core temperature by 1.2 0.2 C. At forearm skin sites distal to the water-perfused suit, local skin temperature was either 35.2 0.6 (mild heating) or 38.2 0.2 C (moderate heating) throughout heat stress and lower-body negative pressure, and remained at these temperatures until presyncope. The reduction in cutaneous vascular conductance during the final 90 s of lower-body negative pressure, relative to heat-stress baseline, was greatest at the mildly heated site (-10 15% reduction) relative to the moderately heated site (-2 12%; P = 0.05 for the magnitude of the reduction in cutaneous vascular conductance between sites), because vasoconstriction at the moderately heated site was either absent or negligible. In hyperthermic individuals, the extent of cutaneous vasoconstriction during a simulated haemorrhage can be modulated by local skin temperature. In situations where skin temperature is at least 38 C, as is the case in soldiers operating in warm climatic conditions, a haemorrhagic insult is unlikely to be accompanied by cutaneous vasoconstriction. PMID:22903981

Pearson, J; Lucas, R A I; Crandall, C G

2012-08-17

122

Adsorption heat pump modeling: the thermal wave process with local equilibrium  

Microsoft Academic Search

This paper describes a model for a thermal-wave adsorption heat pump cycle. Local equilibrium is assumed, providing the asymptotic best-case performance. The model is utilized to examine the performance of adsorption refrigeration cycles powered by low temperature waste heat sources of 373393 K. The impact of varying system temperatures, bed cycling frequency, valve positioning, and sectioning of the bed are

Brian K Sward; M. Douglas LeVan; Francis Meunier

2000-01-01

123

Local Inductive Heating Method Using Novel High-Temperature Implant for Thermal Treatment of Luminal Organs  

Microsoft Academic Search

The authors have previously proposed both a regional heating system, which introduced auxiliary electrodes, and a local inductive heating system, which introduced high-temperature-rise implants. In this paper, we present two novel types of high-temperaturerise implants aiming at luminal organ treatments, namely, a coaxial needle and a stent. Since hot-spot generation may degrade the accuracy of temperature measurements when developing these

Youji Kotsuka; Hiroki Kayahara; Kimitoshi Murano; Hiroto Matsui; Masao Hamuro

2009-01-01

124

Theoretical and experimental study of convection in a fluid layer under conditions of local heating  

NASA Astrophysics Data System (ADS)

Results of a theoretical and experimental study of thermocapillary convection (the Marangoni effect) under conditions of local laser heating are presented for three types of fluids: ethyl alcohol, kerosene, and acetone. An analysis of experimental data obtained by the photochrome visualization method indicates that thermocapillary forces lead to intense heat and mass transfer in the fluids. The experimental and theoretical results are in good agreement, which supports the validity of the theoretical model used in the study.

Al'Vares-Suares, V. A.; Riazantsev, Iu. S.; Shevtsova, V. M.

1990-04-01

125

Estimates of heat flow and heat production and a thermal model of the So Francisco craton  

Microsoft Academic Search

An updated analysis of geothermal data from the highland area of eastern Brazil has been carried out and the characteristics\\u000a of regional variations in geothermal gradients and heat flow examined. The database employed includes results of geothermal\\u000a measurements at 45 localities. The results indicate that the Salvador craton and the adjacent metamorphic fold belts northeastern\\u000a parts of the study area

Carlos H. Alexandrino; Valiya M. Hamza

2008-01-01

126

Heat transport and phonon localization in mass-disordered harmonic crystals  

NASA Astrophysics Data System (ADS)

We investigate the steady-state heat current in two- and three-dimensional disordered harmonic crystals in a slab geometry connected at the boundaries to stochastic white-noise heat baths at different temperatures. The disorder causes short-wavelength phonon modes to be localized so the heat current in this system is carried by the extended phonon modes which can be either diffusive or ballistic. Using ideas both from localization theory and from kinetic theory we estimate the contribution of various modes to the heat current and from this we obtain the asymptotic system size dependence of the current. These estimates are compared with results obtained from a numerical evaluation of an exact formula for the current, given in terms of a frequency-transmission function, as well as from direct nonequilibrium simulations. These yield a strong dependence of the heat flux on boundary conditions. Our analytical arguments show that for realistic boundary conditions the conductivity is finite in three dimensions but we are not able to verify this numerically, except in the case where the system is subjected to an external pinning potential. This case is closely related to the problem of localization of electrons in a random potential and here we numerically verify that the pinned three-dimensional system satisfies Fouriers law while the two-dimensional system is a heat insulator. We also investigate the inverse participation ratio of different normal modes.

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

2010-02-01

127

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

Microsoft Academic Search

Type IV shock wave interference heating on a blunt body causes extremely intense heating over a very localized region of the body. An analytical solution is presented to a heat transfer problem that approximates the shock wave interference heating of an engine cowl leading edge of the National Aero-Space Plane. The problem uses a simplified geometry to represent the leading

David M. McGowan; Charles J. Camarda; Stephen J. Scotti

1992-01-01

128

Stretching and controlled motion of single-stranded DNA in locally heated solid-state nanopores.  

PubMed

Practical applications of solid-state nanopores for DNA detection and sequencing require the electrophoretic motion of DNA through the nanopores to be precisely controlled. Controlling the motion of single-stranded DNA presents a particular challenge, in part because of the multitude of conformations that a DNA strand can adopt in a nanopore. Through continuum, coarse-grained and atomistic modeling, we demonstrate that local heating of the nanopore volume can be used to alter the electrophoretic mobility and conformation of single-stranded DNA. In the nanopore systems considered, the temperature near the nanopore is modulated via a nanometer-size heater element that can be radiatively switched on and off. The local enhancement of temperature produces considerable stretching of the DNA fragment confined within the nanopore. Such stretching is reversible, so that the conformation of DNA can be toggled between compact (local heating is off) and extended (local heating is on) states. The effective thermophoretic force acting on single-stranded DNA in the vicinity of the nanopore is found to be sufficiently large (4-8 pN) to affect such changes in the DNA conformation. The local heating of the nanopore volume is observed to promote single-file translocation of DNA strands at transmembrane biases as low as 10 mV, which opens new avenues for using solid-state nanopores for detection and sequencing of DNA. PMID:23876013

Belkin, Maxim; Maffeo, Christopher; Wells, David B; Aksimentiev, Aleksei

2013-07-26

129

Arc heater nozzle heating test with hydrogen combustion products  

NASA Astrophysics Data System (ADS)

A single-edge expansion test nozzle was tested to obtain hypersonic vehicle flight-level nozzle heating data with simulated hydrogen combustion products. The test objectives were to extend the database for nozzle design and computer code validation, and also to analyze flow patterns using oil flow visualizations. A total of 34 runs were made for 15 and 25 degree nozzle ramp angles and water content of zero and 15 mole percent. Higher water produced higher heating rates, as did a higher enthalpy and lower ramp angle. Test data compared favorably with BARTZ and BLIMPK88 computer code predictions.

Kim, Bernard S. C.; Stoy, Stanley L.; Fivel, Herschel J.

1991-06-01

130

Transport code studies of m=2 mode control by local electron cyclotron heating in TFR  

NASA Astrophysics Data System (ADS)

Transport code simulations of TFR experiments were carried out to determine whether positive results obtained by local electron cyclotron heating are indeed a consequence of profile tailoring. The evolution of the m=2, n=1 tearing mode was evaluated for cylindrical geometry using quasi-linear theory. The conclusion is that the suppression of the magnetohydrodynamic activity with electron cyclotron heating on TFR cannot be due to current profile tailoring alone. The most probable cause is the effect of electron cyclotron heating on the plasma position.

Westerhof, E.; Goedheer, W. J.

1988-06-01

131

Local endwall heat/mass transfer in a pin fin channel  

NASA Astrophysics Data System (ADS)

The naphthalene-sublimation technique of flow visualization is used to ascertain the local endwall heat/mass transfer coefficient distribution in a channel with a staggered array of pin fins, over the Reynolds number range of 9000-33,000. It is found that, near the leading edge, the heat/mass transfer coefficient decreases as a result of boundary layer growth and then increases as the flow encounters the pins on the first and second rows. The streamwise distributions of the heat/mass transfer coefficient downstream of the first pin row are nearly periodic.

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

132

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

NASA Astrophysics Data System (ADS)

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

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

2013-04-01

133

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

PubMed Central

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

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

2010-01-01

134

Local heat/mass transfer distribution around sharp 180 deg turn in a smooth square channel  

NASA Astrophysics Data System (ADS)

The naphthalene sublimation technique is used to determine the heat transfer characteristics of turbulent flow in a three-pass square channel whose segments are connected by two sharp 180-deg turns resembling the internal cooling passages of gas turbine blades and vanes. The results obtained show that spanwise-averaged heat transfer initially decreased with increasing distance from the channel entrance, and then sharply increased upon entering the 180-deg turn; the maximum value is attained toward the turn's end. There exist both a low heat transfer region near the inner wall and a region of high heat transfer near the outer wall. For the three Reynolds numbers investigated, local heat transfer coefficients at the 180-deg turn were 2-3 times higher than the fully developed values.

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

135

Creating a Local Climate Product Using Composite Analysis  

NSDL National Science Digital Library

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

Spangler, Tim

2005-07-01

136

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 26-32C (at air temperatures of 30-38C), 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>26C (approximately 5% perC 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

2013-05-20

137

Tissue-specific localization of heat-stress proteins during embryo development  

Microsoft Academic Search

We report on the stress-independent, tissue-specific expression of the heat-stress protein HSP17 in developing seeds of different plant species and on its intracellular localization. Though HSP17 expression during seed development seems to be a general phenomenon, the isoform patterns, the relative amounts in embryonic tissues and the intracellular localization show species-specific variations. In contrast to the results on the stressinduced

Uta zur Nieden; Dieter Neumann; Alexander Bucka; Lutz Nover

1995-01-01

138

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

PubMed

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

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

2011-10-17

139

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

NASA Astrophysics Data System (ADS)

Urban heat islands and their mitigation take on added significance, both negative and positive, when viewed from a climate-change perspective. In negative terms, urban heat islands can act as local exacerbating factors, or magnifying lenses, to the effects of regional and large-scale climate perturbations and change. They can locally impact meteorology, energy/electricity generation and use, thermal environment (comfort and heat waves), emissions of air pollutants, photochemistry, and air quality. In positive terms, on the other hand, mitigation of urban heat islands (via urban surface modifications and control of man-made heat, for example) can potentially have a beneficial effect of mitigating the local negative impacts of climate change. In addition, mitigation of urban heat islands can, in itself, contribute to preventing regional and global climate change, even if modestly, by helping reduce CO2 emissions from power plants and other sources as a result of decreased energy use for cooling (both direct and indirect) and reducing the rates of meteorology-dependent emissions of air pollutants. This presentation will highlight aspects and characteristics of heat islands, their mitigation, their modeling and quantification techniques, and recent advances in meso-urban modeling of California (funded by the California Energy Commission). In particular, the presentation will focus on results from quantitative, modeling-based analyses of the potential benefits of heat island mitigation in 1) reducing point- and area-source emissions of CO2, NOx, and VOC as a result of reduced cooling energy demand and ambient/surface temperatures, 2) reducing evaporative and fugitive hydrocarbon emissions as a result of lowered temperatures, 3) reducing biogenic hydrocarbon emissions from existing vegetative cover, 4) slowing the rates of tropospheric/ground-level ozone formation and/or accumulation in the urban boundary layer, and 5) helping improve air quality. Quantitative estimates of the above will be presented based on recent and earlier meteorological, energy, thermal environmental, emissions, and photochemical modeling studies for California and Texas.

Taha, H.

2007-12-01

140

Locally Performing an Inner Product Modification on Remote Qubit Product States via Partially Entangled Qubit Pairs  

NASA Astrophysics Data System (ADS)

We give a scheme for locally implementing an inner product modification onto remote qubit product states using partially entangled states, which is designed for obtaining conclusive result with optimal success probability. We exemplify this remote inner product modification (RIPM) by applying it to two-qubit product states via three partially entangled qubit pairs and, additionally, we construct a quantum network to implement this RIPM. It is interesting that our treatment can save entanglement resources.

Chen, Libing; Lu, Hong

2013-10-01

141

Identifying Biomass Sources for Localized Ethanol Production-- Remote Sensing Lesson  

NSDL National Science Digital Library

This remote sensing lesson from iGETT asks the question: "How can communities document local sources of biomass that can be used for energy production?" Students will use ArcGIS and ENVI software to develop a classified map that can be used to identify a source of biomass for energy production. The lesson will guide students through procedures for image processing, creating a vegetative index and identifying areas which have biomass materials. This resource from iGETT includes a learning unit summary, a student guide, supporting documentation and a data file. A quick, free registration is required to view or download any of the materials.

2011-11-04

142

Local permutations of products of Bell states and entanglement distillation  

SciTech Connect

We present different algorithms for mixed-state multicopy entanglement distillation for pairs of qubits. Our algorithms perform significantly better than the best-known algorithms. Better algorithms can be derived that are tuned for specific initial states. These algorithms are based on a characterization of the group of all locally realizable permutations of the 4{sup n} possible tensor products of n Bell states.

Dehaene, Jeroen; Nest, Maarten van den; Moor, Bart; Verstraete, Frank de [Katholieke Universiteit Leuven, Leuven, ESAT-SCD (Belgium); Department of Mathematical Physics and Astronomy, Universiteit Gent, Gent (Belgium)

2003-02-01

143

Medical instrument based on a heat pipe for local cavity hypothermia  

NASA Astrophysics Data System (ADS)

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

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

1996-05-01

144

Accumulation, stability, and localization of a major chloroplast heat- shock protein  

Microsoft Academic Search

Diverse higher plant species synthesize low molecular weight (LMW) heat shock proteins (HSPs) which localize to chloroplasts. These proteins are ho- mologous to LMW HSPs found in the cytoplasm of all eukaryotes, a class of HSPs whose molecular mode of action is not understood. To obtain basic informa- tion concerning the role of chloroplast HSPs, we ex- amined the accumulation,

Qiang Chen; Lisa M. Lauzon; Amy E. DeRocher; Elizabeth Vierling

1990-01-01

145

Meshless Local Petrov-Galerkin Method for Nonlinear Heat Conduction Problems  

Microsoft Academic Search

The meshless local Petrov-Galerkin (MLPG) method is an effective meshless method to solve partial differential equations. In this article, the MLPG method is used to solve nonlinear steady and transient heat conduction problems. The essential boundary condition is enforced by the method of direct interpolation. The moving least-squares (MLS) method is used for interpolation. Thermal conductivity of the material is

Harishchandra Thakur; K. M. Singh; P. K. Sahoo

2010-01-01

146

Local Heat Transfer Distribution in a Rectangular Pin Channel With and Without Vortex Generators  

Microsoft Academic Search

Short pin fins are used to enhance heat transfer rates by increasing the level of turbulence in the trailing edge of gas turbine blades. Experiments are conducted to investigate the local Nusselt number distributions in a staggered pin-fin array using the infrared thermal imaging technique. The pin fins are arranged in a rectangular channel with an aspect ratio of 9.

Amaey Indi; S. V. Prabhu; R. P. Vedula

2011-01-01

147

Development of a new device to measure local heat exchange by evaporation and convection  

NASA Astrophysics Data System (ADS)

According to the principles of heat and mass transfer, the rate of local heat exchange by convection (C) and local heat loss by evaporation (E) can be estimated if temperature and vapor concentration profiles in the boundary layer are measured. In addition, temperature (Ts) and vapor concentration (rho s) at the surface may be predicted from the measured profiles. On this basis, a new device was developed to measure parabolic profiles by incorporating three relative humidity sensors coupled with thermistors into its probe. It has been evaluated from various tests including human experiments. The results showed that the device, with humidity sensors arranged perpendicular to the surface, could estimate C, E, Ts, and rho s in closer agreement with direct measurements when compared with the conventional gradient method. This confirmed that our method had clear advantages over the conventional gradient method under laminar air flow conditions.

Kakitsuba, N.; Katsuura, T.

1992-06-01

148

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

149

Local and average heat transfer characteristics for a disk situated perpendicular to a uniform flow  

NASA Astrophysics Data System (ADS)

The average heat transfer coefficient and the radial distribution of the local heat transfer coefficient were determined experimentally for the case of a circular disk facing a uniform flow for Reynolds numbers ranging from 5000 to 50,000. The wind tunnel experiments employed the naphthalene sublimation technique and covered free-stream velocities from 2.1 to 21 m/s. An analysis was also performed which incorporated the potential flow theory and the boundary layer theory to predict the stagnation point heat transfer. Radial profiles indicate that the local Sherwood number reaches its minimum value at the stagnation point and increases steadily with increasing radial distance from the disk center. Theoretical predictions of the Sherwood number at the stagnation point were found to exceed experimental values by about 6 percent, which is also shown to occur at the stagnation line of a cylinder in crossflow and at the stagnation point of a sphere in a uniform free stream.

Sparrow, E. M.; Geiger, G. T.

1985-05-01

150

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

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

1996-11-01

151

Local Heat Transfer and CHF for Subcooled Flow Boiling - Annual Report 1993  

SciTech Connect

Subcooled flow boiling in heated coolant channels is an important heat transfer enhancement technique in the development of fusion reactor components, where high heat fluxes must be accommodated. As energy fluxes increase in magnitude, additional emphasis must be devoted to enhancing techniques such as sub cooling and enhanced surfaces. In addition to subcooling, other high heat flux alternatives such as high velocity helium and liquid metal cooling have been considered as serious contenders. Each technique has its advantages and disadvantages [1], which must be weighed as to reliability and reduced cost of fusion reactor components. Previous studies [2] have set the stage for the present work, which will concentrate on fundamental thermal hydraulic issues associated with the h-international Thermonuclear Experimental Reactor (ITER) and the Engineering Design Activity (EDA). This proposed work is intended to increase our understanding of high heat flux removal alternatives as well as our present capabilities by: (1) including single-side heating effects in models for local predictions of heat transfer and critical heat flux; (2) inspection of the US, Japanese, and other possible data sources for single-side heating, with the aim of exploring possible correlations for both CHF and local heat transfer; and (3) assessing the viability of various high heat flux removal techniques. The latter task includes: (a) sub-cooled water flow boiling with enhancements such as twisted tapes, and hypervapotrons, (b) high velocity helium cooling, and (c) other potential techniques such as liquid metal cooling. This assessment will increase our understanding of: (1) hypervapotron heat transfer via fins, flow recirculation, and flow oscillation, and (2) swirl flow. This progress report contains selective examples of ongoing work. Section II contains an extended abstract, which is part of and evolving technical paper on single-side f heating. Section III describes additional details which will be included in the first year of work. Section IV summarizes past and anticipated international interactions with investigators from other countries. Finally, Section V gives summaries of two conceptual experiments which are planned for the second and third years.

Dr. Ronald D. Boyd

2000-07-01

152

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

NASA Astrophysics Data System (ADS)

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

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

153

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

154

Explanation of how to run the global local optimization code (GLO) to find surface heat flux  

SciTech Connect

From the evaluation[1] of the inverse techniques available, it was determined that the Global Local Optimization Code[2] can determine the surface heat flux using known experimental data at various points in the geometry. This code uses a whole domain approach in which an analysis code (such as TOPAZ2D or ABAQUS) can be run to get the appropriate data needed to minimize the heat flux function. This document is a compilation of our notes on how to run this code to find the surface heat flux. First, the code is described and the overall set-up procedure is reviewed. Then, creation of the configuration file is described. A specific configuration file is given with appropriate explanation. Using this information, the reader should be able to run GLO to find the surface heat flux.

Aceves, S; Sahai, V; Stein, W

1999-03-01

155

Numerical Study of Generation of Vapor Bubbles by Localized Surface Heating  

NASA Astrophysics Data System (ADS)

The generation of vapor bubbles by rapid, intensive localized Surface heating is studied numerically. The heating process is Modeled by providing a heat flux over a finite region between a semi-infinite fluid and a semi-infinite solid for a given period. A small spherical nucleus is than introduced into the liquid near the liquid-solid interface. The nucleus is initially filled with vapor at the temperature of its surrounding liquid. An convection-conduction equation for the energy and Laplace equation for the fluid motion are solved over a non-orthogonal grid system. The bubble internal vapor pressure is then calculated by equilibrium thermodynamics. Maximum bubble size, bubble life time and bubble shape evolution and their relationship with controlling heating parameters are going to be presented.

Yuan, H.; Prosperetti, A.; Yin, Z.

2000-11-01

156

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

NASA Astrophysics Data System (ADS)

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

Blackwell, D. D.; Thakur, M.

2007-12-01

157

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

National Technical Information Service (NTIS)

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

E. Stroem T. Ekeborg

1991-01-01

158

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

Federal Register 2010, 2011, 2012, 2013

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

2012-12-12

159

Noninvasive measurement of local thermal diffusivity using backscattered ultrasound and focused ultrasound heating.  

PubMed

Previously, noninvasive methods of estimating local tissue thermal and acoustic properties using backscattered ultrasound have been proposed in the literature. In this article, a noninvasive method of estimating local thermal diffusivity in situ during focused ultrasound heating using beamformed acoustic backscatter data and applying novel signal processing techniques is developed. A high intensity focused ultrasound (HIFU) transducer operating at subablative intensities is employed to create a brief local temperature rise of no more than 10 degrees C. Beamformed radio-frequency (RF) data are collected during heating and cooling using a clinical ultrasound scanner. Measurements of the time-varying "acoustic strain", that is, spatiotemporal variations in the RF echo shifts induced by the temperature related sound speed changes, are related to a solution of the heat transfer equation to estimate the thermal diffusivity in the heated zone. Numerical simulations and experiments performed in vitro in tissue mimicking phantoms and excised turkey breast muscle tissue demonstrate agreement between the ultrasound derived thermal diffusivity estimates and independent estimates made by a traditional hot-wire technique. The new noninvasive ultrasonic method has potential applications in thermal therapy planning and monitoring, physiological monitoring and as a means of noninvasive tissue characterization. PMID:18450361

Anand, Ajay; Kaczkowski, Peter J

2008-05-01

160

Local warming of groundwaters caused by the urban heat island effect in Istanbul, Turkey  

NASA Astrophysics Data System (ADS)

The urban heat island (UHI) is a result of urbanization, causing local microclimatologic changes such as increase in ambient temperature. Factors causing the UHI effect are anthropogenic energy release, energy absorption by concrete, tarmac structures and traffic, although the main factor is the replacement of vegetation with man-made structures. These factors cause heating of not only local air but also subsurface and groundwater. Observations of groundwater temperatures from the urban, southern part of Istanbul (Turkey) and the rural, northern part of Istanbul revealed that the urban groundwater temperatures were 3.5C higher than the rural. Urbanization is a direct consequence of improvements in technology and modern life. However, this comes at the cost of an ever-increasing demand for energy. Exploitation of low-enthalpy geothermal energy is an attractive alternative to fossil fuel based energies. From the environmental point of view, clean and cheap energy is the most preferable, with heat pumps being the best choice for recovery purposes. Usage of elevated groundwater temperature in the heat pumps in urban areas increases the efficiency of the heat pump system and yields more thermal energy than that of rural groundwater. This system may be applicable to Istanbul.

Yalcin, Tolga; Yetemen, Omer

2009-07-01

161

Sensor for the detection of local contrast gloss of products.  

PubMed

We introduce a sensor for providing information on the local contrast gloss (or luster) of products. The sensor also provides information of the local specular gloss of the object. The signals of this sensor are produced by diffractive optical elements from fields that are scattered in the diffuse and specular directions from the object. We present specular gloss, diffuse-reflectance factor related to the contrast gloss, and visibility maps measured from black prints on paper. High variation can be observed in the relevant gloss parameters obtained from the printed area. In addition, borders of the print can be clearly detected from the diffuse-reflectance-factor maps. The sensor also allows detection of raster points of a print. This sensor opens up entirely new means to study prints and other substances. PMID:18382507

Oksman, Antti; Juuti, Mikko; Peiponen, Kai-Erik

2008-04-01

162

Determination of local fluid drag by a laser heating\\/thermographic phosphor technique: Applicability of the H. Ludwieg model  

Microsoft Academic Search

A new application of laser thermography, that utilizes local heat- transfer measurements to deduce local fluid-induced drag is proposed and analyzed. The analytical model originally developed by H. Ludwieg is extended to account for heat conduction in the wall, and the limitations in Reynolds number that correspond to the Ludwieg assumption of a thin thermal boundary layer for air and

J. J. Keyes Jr.; W. K. Sartory

1988-01-01

163

Bias-induced local heating in atom-sized metal contacts at 77 K  

SciTech Connect

Local heating in Zn atom-sized contacts is studied at 77 K under high biases. Switching rate {nu} of two-level fluctuations of the contact conductance is measured and statistically analyzed to estimate the contact effective temperature. Typical log {nu} increases linearly with the bias up to 0.35 V, which suggests negligible contact heating in the low-bias regime. Above 0.4 V, however, log {nu} rises steeply with the bias due to an onset of contact overheating. The estimated contact temperature rises more rapidly with the bias than the {radical}(V) dependence derived theoretically.

Tsutsui, Makusu; Kurokawa, Shu; Sakai, Akira [International Innovation Center, Kyoto University, Sakyo-ku, Kyoto 606-8501 (Japan)

2007-03-26

164

Sustained laser induced incandescence in carbon nanotubes for rapid localized heating  

SciTech Connect

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

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

2009-02-16

165

A Technique for Locally Increasing Surface Heat Spreading and through-Thickness Thermal Conductivity of Graphite\\/Epoxy Laminates  

Microsoft Academic Search

The polymer matrix composite through-thickness thermal conductivity is particularly important in applications such as composite spaceborne electronics enclosures where the heat dissipation is primarily dependent on thermal conduction to a heat sink. The spreading of heat at the composite surface and subsequent localized conduction in the through-thickness direction down to high thermal conductivity fiber may be the key to designing

Jack C. Roberts; Mark H. Luesse; Thomas C. Magee

1996-01-01

166

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

Federal Register 2010, 2011, 2012, 2013

...Packages Provided With Multiple Heat- Conducting Paths and Products...Packages Provided With Multiple Heat-Conducting Paths and Products...packages provided with multiple heat-conducting paths and products...confidence must request confidential treatment. All such requests should...

2012-06-06

167

Shear heating induced lithospheric-scale localization: Does it result in subduction?  

NASA Astrophysics Data System (ADS)

Even though it is a well-established fact that the Earth is currently in a plate-tectonics mode, the question on how to "break" lithospheric plates and initiate subduction remains a matter of debate. Here we focus on shear heating as a potential mechanism to cause lithospheric shear localization and subsequent subduction initiation in oceanic plates. It is shown that shear heating under some conditions (i) facilitates the formation of a lithospheric-scale shear zone and (ii) is capable of stabilizing a lithospheric-scale shear zone, thus creating the necessary condition for subduction initiation to occur. Furthermore, we demonstrate that not only the localization process is of importance, but also the post-localization stage, where rapidly growing convective instabilities might prevent an incipient subduction zone from developing.We develop scaling laws for both the localization and the post-localization stages. In the case of lithospheric localization, the characteristic length scale equals a quarter of the dominant folding wavelength in the lithosphere, thus of the order of the competent layer thickness. This shows that oceanic lithosphere develops an intrinsic perturbation length scale that is largely independent of smaller-scale heterogeneities. We compare the subduction initiation potential of wet olivine and dry olivine rheologies and find that, for Earth-like conditions, a dry olivine rheology is more likely to result in subduction initiation. A large plate age does not always increase the potential for subduction initiation, as it increases the potential for convective instabilities to occur. Instead, an optimal plate age exists for shear heating induced subduction initiation, which is around 40 Ma for a wet olivine rheology.

Thielmann, Marcel; Kaus, Boris J. P.

2012-12-01

168

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

NASA Astrophysics Data System (ADS)

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

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

1988-12-01

169

Local mass (heat) transfer distribution over the concave surface of a turbine blade  

NASA Astrophysics Data System (ADS)

This paper presents mass transfer results over the concave surface of a turbine blade using a naphthalene sublimation technique. An automated data acquisition system was employed to investigate the local mass transfer coefficient over a simulated turbine blade in a planar cascade. Results show a large variation along the spanwise direction in local mass transfer distribution even in the two-dimensional flow region, possibly due to the effect of Taylor vortices. The average mass transfer distribution over the measured span has a sharp decrease in the leading edge region and a rapid increase at both the reattachment of the boundary layer flow and the trailing edge. A comparison with an early study using a direct heat transfer method is made and shows good agreement in the general trend of the heat transfer distribution.

Chen, Ping-Hei; Goldstein, Richard J.

1990-04-01

170

Electron correlation effects on the diode properties and the local heating  

NASA Astrophysics Data System (ADS)

Single molecular bridge junctions and atomic wires provide one of the best test fields for non-equilibrium transport theories whose progress gives benefits over wide range of physics. Experimental progresses in inelastic tunneling spectroscopy (IETS) and break junction techniques have played very important roles to make this possible. Inelastic scatterings between electrons and phonons give ``local heating'' of the junctions. The effective temperature due to the local heating was discussed successfully in terms of a fully self-consistent theory treating energy dissipation processes as well as inelastic heat generation on equal footing [1]. Recently, we found two cases where electron correlation gives distinct changes. The first case was found in the local heating problem in the resonant systems, where phonon damping due to its coupling with electron-hole excitation is suppressed by the correlation. The suppression enhances heat release to electrodes leading to the effective temperature suppression [2]. Another example is the single molecular rectifier. First principle NEGF-GGA calculation fails to explain the large rectification ratio (RR) at high bias voltage. Separate GW calculation based on Keldysh Green's function gives clear enhancement of RR over the mean field NEGF results suggesting that RR could be enhanced by the electron correlation effect [3]. Thus latest non-equilibrium transport theories enable us to treat the important physical processes accompanying electric conduction allowing us to make more direct comparisons with experimental phenomena at nano-scale. [4pt] [1] Y. Asai, Phys. Rev. B78, 045434 (2008).[0pt] [2] Y. Asai, Phys. Rev. B84, 085436 (2011).[0pt] [3] Y. Asai, H. Nakamura, J. Hihath, C. Bruot, and N.J Tao, Phys. Rev. B 84, 115436 (2011).

Asai, Yoshihiro

2012-02-01

171

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

NASA Astrophysics Data System (ADS)

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

Chen, Youping

2006-02-01

172

The effect of heat transfer on local solidification kinetics of eutectic Al-Si cast alloy  

Microsoft Academic Search

Recently, Fourier thermal analysis (FTA) has been proposed as a suitable technique to obtain information about local solidification\\u000a kinetics in casting alloys. In this work, FTA was applied to a near-eutectic aluminum-silicon cast alloy in order to seek\\u000a experimental evidence supporting the solidification kinetics obtained from this method. Also, a heat-transfer\\/solidification-kinetics\\u000a model was used to compare predictions with experimental results.

C. Gonzlez-Rivera; M. H. Cruz; H. A. Garca; J. A. Juarez-Islas

1999-01-01

173

Local laser heat treatment of ultra high strength steels to improve formability  

Microsoft Academic Search

Ultra high strength steels are of enormous interest especially in the automotive industry due to their potential in realising\\u000a light weight structures and improving the crash behaviour. However the poor formability of these steels limits their application\\u000a for many parts in the car body. A solution to this limitation can be a local heat treatment using a laser beam to

Reimund Neugebauer; Sren Scheffler; Reinhart Poprawe; Andreas Weisheit

2009-01-01

174

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-transmitreceive 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 (<1C). Under standard conditions, we observed greater heating (?2.0C) at 3T on one system and similar heating (<1C) 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 (+6.4C) 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;28:12331244. 2008 Wiley-Liss, Inc.

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

2008-01-01

175

Nicotine increases initial blood flow responses to local heating of human non-glabrous skin  

PubMed Central

Nicotine affects the regulation of skin blood flow (SkBF), but the mechanisms involved are not well understood. We tested the hypothesis that acute exposure to nicotine inhibits both the initial neurally mediated component and the later sustained component of SkBF responses to local heating of non-glabrous skin in humans. SkBF (measured by laser-Doppler) responses to local heating of forearm skin from 32 to 42C were measured in 11 chronic smokers. Heating occurred at one site over 15 min (RAMP) and over 90 s (STEP) at another site, and was maintained for an additional 30 min. STEP heating was also applied to a site pretreated with bretylium via iontophoresis to inhibit noradrenergic neurotransmission. Responses were measured before and after acute administration of nicotine via cigarettes or nasal spray in two experimental sessions. Nicotine decreased resting skin blood flow (P < 0.05); this response was inhibited by bretylium. During RAMP, nicotine increased the initial SkBF at 42C (by ?12%, P < 0.05). For STEP, nicotine increased the initial peak response (by ?25%, P < 0.05), and decreased the sustained plateau value (by ?10%, P < 0.05). In skin pretreated with bretylium, the increase caused by nicotine in the initial peak value persisted, but the plateau value was not different from pre-nicotine. These data suggest that in abstinent cigarette smokers, nicotine augments initial responses to both gradual and rapid non-painful heating of non-glabrous skin by sensitizing the sensory nerves that mediate the axon reflex associated with rapid vasodilatation. In contrast, nicotine decreases SkBF responses to prolonged heating by activating noradrenergic nerves.

Warner, David O; Joyner, Michael J; Charkoudian, Nisha

2004-01-01

176

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, Jrgen P.

2013-04-01

177

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

NASA Astrophysics Data System (ADS)

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 (Jyvskyl, 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.

2006-03-01

178

Influence of surface heating condition on local heat transfer in a rotating square channel with smooth walls and radial outward flow  

SciTech Connect

The effect of a surface heating condition on the local heat transfer coefficient in a rotating square channel with smooth walls and radial outward flow was investigated for Reynolds numbers from 2,500 to 25,000 and rotation numbers from 0 to 0.352. The square channel, composed of six isolated copper sections, has a length-to-hydraulic diameter ratio of 12. The mean rotating radius to the channel hydraulic diameter ratio is kept at a constant value of 30. Four surface heating conditions were tested: (1) four walls at uniform temperature, (2) temperature ratio of leading surface to side wall and trailing surface to side wall is 1.05 and 1.10, respectively, (3) trailing surface hot and remaining three walls cold, and (4) leading surface not and remaining three walls cold. The results show that the heat transfer coefficients on the leading surface are much lower than that of the trailing surface due to rotation. For case (1) of four walls at uniform temperature, the leading surface heat transfer coefficient decreases and then increases with increasing rotation numbers, and the trailing surface heat transfer coefficient increases monotonically with rotation numbers. However, the trailing surface heat transfer coefficients for cases (2) and (3) are slightly lower than case (1), and the leading surface heat transfer coefficients for cases (2) and (4) are significantly higher than for case (1). The results suggest that the local wall heating condition creates the local buoyancy forces, which reduce the effects of the bulk buoyancy and Coriolis forces. Therefore, the local heat transfer coefficients on the leading and trailing surfaces are altered by the surface local heating condition.

Han, J.C.; Zhang, Y.M. (Texas A M Univ., College Station, TX (United States). Dept. of Mechanical Engineering); Lee, C.P. (General Electric Co., Cincinnati, OH (United States))

1994-01-01

179

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

Microsoft Academic Search

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

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

2008-01-01

180

Optical investigation of heat release and NOx production in combustion  

NASA Astrophysics Data System (ADS)

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

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

2005-08-01

181

Optical investigation of heat release and NOx production in combustion  

NASA Astrophysics Data System (ADS)

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

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

2007-10-01

182

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

SciTech Connect

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

Dr. Ronald D. Boyd

2000-07-01

183

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

Microsoft Academic Search

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

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

1990-01-01

184

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

185

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

SciTech Connect

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

Van Treuren, K.W.; Wang, Z.; Ireland, P.T.; Jones, T.V. (Univ. of Oxford (United Kingdom). Dept. of Engineering Science)

1994-07-01

186

Energetic efficiency of cogeneration systems for combined heat, cold and power production  

Microsoft Academic Search

This paper deals with the problem of energetic efficiency evaluation of cogeneration systems for combined heat, cold and power production. Cogeneration systems have a large potential for energy saving, especially when they simultaneously produce heat, cold and power as useful energy flows. Various cogeneration systems for combined heat, cold and power production are designed by means of computer simulation to

V Havelsk

1999-01-01

187

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

188

Transient heat transfer analysis in air cooling of individual spherical products  

Microsoft Academic Search

This study presents a new approach for analyzing unsteady heat transfer during forced air cooling of figs as spherical products. In the cooling of food products, conduction, convection, radiation, and internal heat generation take place. Moisture loss is coupled with heat transfer. An analytical scheme is presented for solving these equations for three cases, namely, h = hc, h =

Ibrahim Dincer

1995-01-01

189

Tubular reabsorption and local production of urine hepcidin-25  

PubMed Central

Background Hepcidin is a central regulator of iron metabolism. Serum hepcidin levels are increased in patients with renal insufficiency, which may contribute to anemia. Urine hepcidin was found to be increased in some patients after cardiac surgery, and these patients were less likely to develop acute kidney injury. It has been suggested that urine hepcidin may protect by attenuating heme-mediated injury, but processes involved in urine hepcidin excretion are unknown. Methods To assess the role of tubular reabsorption we compared fractional excretion (FE) of hepcidin-25 with FE of ?2-microglobulin (?2m) in 30 patients with various degrees of tubular impairment due to chronic renal disease. To prove that hepcidin is reabsorbed by the tubules in a megalin-dependent manner, we measured urine hepcidin-1 in wild-type and kidney specific megalin-deficient mice. Lastly, we evaluated FE of hepcidin-25 and ?2m in 19 patients who underwent cardiopulmonary bypass surgery. Hepcidin was measured by a mass spectrometry assay (MS), whereas ?2m was measured by ELISA. Results In patients with chronic renal disease, FE of hepcidin-25 was strongly correlated with FE of ?2m (r?=?0.93, P <0.01). In megalin-deficient mice, urine hepcidin-1 was 7-fold increased compared to wild-type mice (p?local production at 1224hours. Conclusions Hepcidin-25 is reabsorbed by the renal tubules and increased urine hepcidin-25 levels may reflect a reduction in tubular uptake. Uncoupling of FE of hepcidin-25 and ?2m in cardiac surgery patients suggests local production.

2013-01-01

190

Toxicological evaluation of some Malaysian locally processed raw food products.  

PubMed

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

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

2007-08-19

191

Local mass/heat transfer from a wall-mounted block in rectangular channel flow  

NASA Astrophysics Data System (ADS)

This investigation explores the mass/heat transfer from a wall-mounted block in a rectangular fully developed channel flow. The naphthalene sublimation scheme was used to measure the level of local mass transfer from the blocks surfaces. The heat transfer coefficient can be obtained by analogy between heat and mass transfer. The effects of the Reynolds number on the local mass transfer from the blocks surfaces have been widely discussed. Results showed that, owing to the flow complexity induced by vortices around the block, the blocks surfaces appeared four different spatial Sherwood number distributions, termed Wave type, U type, Slant type, and Pit type. A change in the Reynolds number significantly altered the spatial Sherwood number distributions on the blocks surfaces. Besides, four correlations between the Reynolds number and the surface-averaged Sherwood number were presented for the front, top, side, and rear surfaces of the block at a given blocks height, for the purpose of practical applications.

Wang, Kun-Chieh; Chiou, Ruey-Tsorng

2006-05-01

192

Experimental measurement of local heat transfer coefficients over discrete roughened plates using infrared thermography  

NASA Astrophysics Data System (ADS)

Convective heat transfer over ribbed surfaces is a very complex process that requires detailed measurements for further understanding. Recent developments in infrared detector designs, optical attachments and computer and video capabilities have produced accurate infrared thermography systems with the spatial resolution required to obtain local heat transfer measurements on surfaces of complex geometry. Thus infrared thermography represents an attractive alternative to existing methods for heat transfer measurements (i.e. thermocouples, naphthalene sublimation, or liquid crystal measurements). The present investigation describes a new experimental method which uses infrared thermography in a subsonic wind tunnel to obtain detailed temperature measurements over ribbed plates with constant heat flux. The infrared system used in this study incorporated an infrared detector with a closed cycle microcooler which permitted the infrared camera to be positioned at arbitrary viewing angles. This flexibility permitted direct observations of the ribbed surface without the use of reflective optics that would have increased the inaccuracy of the procedure. Reference thermocouples placed at strategic locations over the ribbed plates were used to correct temperature readings of the infrared system in order to minimize measurement errors. Three ribbed plates were tested. Plates A and B had ribs of square cross section. The rib spacing (pitch) on plate A was designed so that regions of separation and reattachment would occur on the plate between ribs whereas plate B was designed to produce only regions of separation and recirculation. Plate C was constructed as an improved version of plate A and included trapezoidal ribs. The rib height and pitch on plate C was the same as on plate A. The trapezoidal shape of the rib for plate C was designed to minimize the recirculation regions in the front and back of the ribs while allowing reattachment at the base surface of the plate. Local heat transfer coefficients surrounding the ribs are presented and comparisons between plates are drawn. It is shown that the new method of heat transfer measurement is able to detect numerous small scale features of the complex flow field and consequent heat transfer distribution around ribs of arbitrary shape.

Aliaga, David Alfredo

193

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

NASA Astrophysics Data System (ADS)

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

Tikhonov, Konstantin S.; Sinova, Jairo; Finkel'Stein, Alexander M.

2013-06-01

194

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

PubMed

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

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

2013-01-01

195

Accumulation, stability, and localization of a major chloroplast heat- shock protein  

PubMed Central

Diverse higher plant species synthesize low molecular weight (LMW) heat shock proteins (HSPs) which localize to chloroplasts. These proteins are homologous to LMW HSPs found in the cytoplasm of all eukaryotes, a class of HSPs whose molecular mode of action is not understood. To obtain basic information concerning the role of chloroplast HSPs, we examined the accumulation, stability, tissue specificity, and intra- chloroplast localization of HSP21, the major LMW chloroplast HSP in pea. Intact pea plants were subjected to heat stress conditions which would be encountered in the natural environment and HSP21 mRNA and protein levels were measured in leaves and roots. HSP21 was not detected in leaves or roots before stress, but the mature, 21-kD protein accumulated in direct proportion to temperature and HSP21 mRNA levels in both tissues. All of the HSP21 in leaves was localized to chloroplasts; there was no evidence for its transport into other organelles. In chloroplast fractionation experiments, greater than 80% of HSP21 was recovered in the soluble chloroplast protein fraction. The half-life of HSP21 at control temperatures was 52 +/- 12 h, suggesting the protein's function is critical during recovery as well as during stress. We hypothesize that HSP21 functions in a catalytic fashion in both photosynthetic and nonphotosynthetic plastids.

1990-01-01

196

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

197

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

198

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

National Technical Information Service (NTIS)

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

E. Nolting

1984-01-01

199

Crack arrest toughness of a heat-affected zone containing local brittle zones  

SciTech Connect

The awareness of the presence of local brittle zones (LBZs) in the heat-affected zone (HAZ) of welds has led to the requirements for minimum initiation toughness for the HAZ for critical applications. A fracture control philosophy that is proposed to be an attractive alternative for heat-affected zones containing LBZs is the prevention of crack propagation rather than of crack initiation. Such an approach would be viable if it could be demonstrated that cracks initiated in the LBZs will be arrested without causing catastrophic failure, notwithstanding the low initiation (CTOD) toughness resulting from the presence of LBZs. Unstable propagation of a crack initiating from an LBZ requires the rupture of tougher microstructural regions surrounding the LBZ in HAZ, and therefore the CTOD value reflecting the presence of LBZ is unlikely to provide a true indication of the potential for fast fracture along the heat-affected zone. Base metal specifications usually ensure that small unstable cracks propagating from the weld zone into the base metal would be arrested. To investigate the likelihood of fast fracture within the HAZ, a test program has been carried out that involved performing compact plane strain and plane stress crack arrest tests on a heat-affected zone that contained LBZs, and thus exhibited unacceptable low CTOD toughness for resistance to brittle fracture initiation. The results indicated that the crack arrest toughness was little influenced by the presence of local brittle zones. Instead, the superior toughness of the larger proportion of finer-grain HAZ surrounding the LBZ present along the crack path has a greater influence on the crack arrest toughness.

Malik, L.; Pussegoda, L.N. [Fleet Technology Ltd., Kanata, Ontario (Canada); Graville, B.A. [Graville Associates Inc., Georgetown, Ontario (Canada); Tyson, W.R. [CANMET, Ottawa, Ontario (Canada). Metals Technology Labs.

1996-11-01

200

Heat recovery from molten CuCl in the CuCl cycle of hydrogen production  

Microsoft Academic Search

The copperchlorine (CuCl) cycle of thermochemical hydrogen production requires heat recovery from molten CuCl at various points within the cycle. This paper examines the convective heat transfer between molten CuCl droplets and air in a counter-current spray flow heat exchanger. This direct contact heat exchanger is analyzed as a proposed new method of recovering heat from the solidified molten CuCl.

O. Jaber; G. F. Naterer; I. Dincer

2010-01-01

201

Induction of Cambial Reactivation by Localized Heating in a Deciduous Hardwood Hybrid Poplar (Populus sieboldii x P. grandidentata)  

PubMed Central

Background and Aims The timing of cambial reactivation plays an important role in the control of both the quantity and the quality of wood. The effect of localized heating on cambial reactivation in the main stem of a deciduous hardwood hybrid poplar (Populus sieboldii P. grandidentata) was investigated. Methods Electric heating tape (2022 C) was wrapped at one side of the main stem of cloned hybrid poplar trees at breast height in winter. Small blocks were collected from both heated and non-heated control portions of the stem for sequential observations of cambial activity and for studies of the localization of storage starch around the cambium from dormancy to reactivation by light microscopy. Key Results Cell division in phloem began earlier than cambial reactivation in locally heated portions of stems. Moreover, the cambial reactivation induced by localized heating occurred earlier than natural cambial reactivation. In heated stems, well-developed secondary xylem was produced that had almost the same structure as the natural xylem. When cambial reactivation was induced by heating, the buds of trees had not yet burst, indicating that there was no close temporal relationship between bud burst and cambial reactivation. In heated stems, the amount of storage starch decreased near the cambium upon reactivation of the cambium. After cambial reactivation, storage starch disappeared completely. Storage starch appeared again, near the cambium, during xylem differentiation in heated stems. Conclusions The results suggest that, in deciduous diffuse-porous hardwood poplar growing in a temperate zone, the temperature in the stem is a limiting factor for reactivation of phloem and cambium. An increase in temperature might induce the conversion of storage starch to sucrose for the activation of cambial cell division and secondary xylem. Localized heating in poplar stems provides a useful experimental system for studies of cambial biology.

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

2007-01-01

202

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

PubMed

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

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

2011-10-09

203

Experimental study on local heat transfer with liquid impingement flow in two-dimensional micro-channels  

Microsoft Academic Search

Experiments were performed to investigate the heat transfer characteristics of impingement flow of transformer oil and 3M fluorinert liquid FC-72 in two-dimensional micro-channels. Jet impingement technique was used in this research for its high heat transfer rate and large potential in industrial applications. Local heat transfer coefficients were recorded both at stagnation and parallel flow regions in the range of

Y. Zhuang; C. F. Ma; M. Qin

1997-01-01

204

Do Local Production, Organic Certification, Nutritional Claims, and Product Branding Pay in Consumer Food Choices?  

Microsoft Academic Search

This research furthers the assessment of consumer demand for locally produced foods, while also considering a host of other food attributes that may interact to influence consumer utility. Using stated preference data from a choice-based conjoint analysis survey instrument, we estimate willingness-to-pay for processed food products (blackberry jam) that are differentiated with respect to their branding, the location of their

Marvin T. Batte; Wuyang Hu; Timothy A. Woods; Ernst Stan

2010-01-01

205

Changes in volatile compounds of palm sap ( Arenga pinnata) during the heating process for production of palm sugar  

Microsoft Academic Search

This study was carried out to determine the changes of volatile compounds composition during palm sugar production. The samples were collected at every 30min interval for 4h of heating process at 150C from a local traditional manufacturer in Kuala Pilah, Malaysia. The analyses were performed by gas chromatographymass spectrometry after headspace solid phase micro extraction. The results showed that N-heterocyclic

C. W. Ho; W. M. Wan Aida; M. Y. Maskat; H. Osman

2007-01-01

206

Productivity of local chickens under village management conditions.  

PubMed

The productivity of local chickens under village management conditions was studied in six villages situated in three climatic zones within Morogoro District in Tanzania. Two villages were picked in each climatic zone (warm and wet, warm and dry, cool and wet) for the study. The data were obtained by actual measurement, qualitative observations and interview of members of the households directly responsible for the care of chickens. In addition, data sheets were given to selected farmers to record the performance of their chickens. The mean flock size for the three zones was 16.2, with a range of 2 to 58. The overall mean clutch size, egg weight and hatchability were 11.8, 44.1 g and 83.6%, respectively. The overall mean chick survival rate to 10 weeks of age was 59.7%. The mean live weights for cocks and hens were 1948 g and 1348 g, respectively. The mean growth rates to the age of 10 weeks were 4.6 g/day and 5.4 g/day, while those from 10 to 14 weeks of age were 8.4 g/day and 10.2 g/day for female and male birds, respectively. The age at first lay ranged between 6 and 8 months, and the average hen had three laying cycles per year. Most of the chickens were left to scavenge during the day and were provided with simple housing at night (95.2% of the owners). Only small amounts of supplementary feeds were occasionally given and minimal health care was provided. It was concluded that the low productivity of chickens was partly due to the prevailing poor management practices, in particular the lack of proper health care, poor nutrition and housing. PMID:12379059

Mwalusanya, N A; Katule, A M; Mutayoba, S K; Mtambo, M M A; Olsen, J E; Minga, U M

2002-09-01

207

Interleukin6 Production in Human Intestinal Epithelial Cells Increases in Association with the Heat Shock Response  

Microsoft Academic Search

Background.In recent studies, IL-1? stimulated the production of IL-6 in human enterocytes. The heat shock response influences the production of inflammatory mediators in certain cell types. We tested the hypothesis that heat shock regulates IL-1?-induced IL-6 production in human intestinal epithelial cells.Materials and methods.Cultured Caco-2 cells, a human intestinal epithelial cell line, were exposed to thermal heat shock at 43C

Alexander A. Parikh; M. Ryan Moon; Christine D. Kane; Andrew L. Salzman; Josef E. Fischer; Per-Olof Hasselgren

1998-01-01

208

Local Governments' Behavior in Promoting the Product-market-based Cycle Agriculture  

Microsoft Academic Search

The thesis focuses on studying the local governments' behavior based on the product market and studying how local governments improve the competitiveness of the cycle agriculture and promote its development in the region by influencing the farming producers' operating environment. By combining the farming households' Cournot equilibrium, agricultural products processing enterprises' Bertrand equilibrium and local governments' behavior functions, the thesis

Chen Hong; Shi Shuai

2007-01-01

209

Living local, growing global: Renegotiating the export production regime in New Zealands pipfruit sector  

Microsoft Academic Search

The articulation between global food commodity complexes and the local production regimes of particular contexts is a major gap in the new political economy literature on food regimes, food complexes, agricultural restructuring and local adjustment. This paper explores how different regions of producers in the New Zealand apple industry in the mid-1990s have negotiated the local export regime of production

Megan McKenna; Richard Le Heron; Michael Roche

2001-01-01

210

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

PubMed Central

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

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

2012-01-01

211

Transient fluid flow and heat transfer in petroleum production systems  

NASA Astrophysics Data System (ADS)

Heat transfer is an important phenomenon in both wellbore and reservoir. The pertinent temperature distribution can provide a valuable perspective in analyzing and optimizing the oil production. In this work, two kinds of co-production, production fluid through the annulus and tubing, and through two independent tubings, have been modeled using steady state analysis. The fluid temperatures in the production string and annulus have been solved analytically in both cases. Furthermore, we extended the theory of steady state energy transport to remedy asphaltene deposition problem by circulating the cooling fluid in the annulus. Due to the complex nature of two-phase flow in the oil/gas production, more reliable mechanistic modeling approaches have been developed since early 1980's. Rooted in Hasan-Kabir model, we have developed a wellbore/reservoir coupling simulator for the transient non-Darcy two-phase flow in the flow-after-flow well test. The entire historical flow behavior has been modeled using superposition method and validated with field data. Our second simulation is for the investigation of a blowout well, which is a great concern in the oil field. When the pressure in the wellbore is sufficiently high, the fluids will attain sonic velocity at the wellhead. We presented a computational algorithm to estimate the blowout rate in a given wellbore/reservoir system and examined four major parameters, such as formation permeability, Gas-Oil-Ratio (GOR), reservoir pressure and tubing diameter. The transient nature of this approach also illustrates the evolution process of a blowout. We have also developed a transient simulator to determine the location and severity of a blockage in a gas pipeline based on the theory of two-phase flow and pressure transient analysis. The presence of a sizeable blockage will affect the outlet gas pressure response by decreasing the available pipe volume and increasing the friction loss of the fluid flow. The simulator solves for the pressure response using a finite and iterative numerical method with transport theory of mass and momentum. Comparing the outlet transient pressure signature from a clean pipeline with those having a plug shows that the predictions of our model agree well with the experimental data.

Lin, Dongqing

212

Local heat/mass transfer distribution in a square channel with full and V-shaped ribs  

NASA Astrophysics Data System (ADS)

Naphthalene sublimation experiments have been conducted to study the turbulent heat/mass transfer characteristics of airflow in a square channel, in which two opposite walls are roughened with aligned arrays of full ribs and V-shaped ribs. The detailed distributions of the local heat/mass transfer coefficient on the ribbed walls and on the smooth walls are obtained. Results show that there are significant spanwise as well as streamwise variations of the local heat/mass transfer coefficient on the exposed surfaces of the ribbed walls in the oblique full rib and V-shaped rib cases.

Kukreja, R. T.; Lau, S. C.; McMillin, R. D.

1993-05-01

213

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

NASA Astrophysics Data System (ADS)

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

Barlow, Douglas N.

1994-08-01

214

A Local-in-Space-Timestep Approach to a Finite Element Discretization of the Heat Equation with a Posteriori Estimates  

Microsoft Academic Search

A new discretization method is presented in this paper for the heat equation with discontinuous coefficients based on a Crank-Nicolson scheme and a conforming finite element space discretization. In the proposed method each node of the spatial discretization may have the global timestep split into an arbitrary number of local substeps in order to pursue a local improvement of the

Stefano Berrone

2009-01-01

215

Differential heat shock tolerance and expression of heat shock inducible proteins in two stored-product psocids  

Technology Transfer Automated Retrieval System (TEKTRAN)

The recent recognition of psocid infestations as a major concern in stored products, where their management with fumigants and conventional insecticides has proven difficult, and also the recent reemergence of heat treatment as a potential tactic for control of stored-product insects led to the pres...

216

The Political Ecology of Banana Exports and local Food Production in St. Vincent, Eastern Caribbean  

Microsoft Academic Search

In St. Vincent and the Grenadines in the Eastern Caribbean, export banana production is expanding at the same time that local food production is declining and food imports are rising. When export agriculture is accompanied by such changes, the general assumption in much of the development literature, including political ecology, is that export agriculture has undermined local food production, leading

Lawrence S. Grossman

1993-01-01

217

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

SciTech Connect

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

Windows and Daylighting Group

1997-12-08

218

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

NASA Astrophysics Data System (ADS)

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

Tong, Michael Shou-Ming

219

On the possibility of localization of a substorm by using the "Sura" heating facility  

NASA Astrophysics Data System (ADS)

We present the results of analysis of helio-geophysical conditions for the experiments performed in 2007-2010 to study modification of the ionosphere by high-power radio emission of the "Sura" heating facility. The feature of the experiments is that the operating frequency of the facility exceeded the upper-hybrid frequency for the F2 layer maximum in the ionosphere. All the experiments were performed in the local-time sector of the Harang discontinuity (i.e., from 21:00 to 00:00, local time) to ensure the most probable influence of the facility operation on the onset of natural processes in the subauroral region of the ionosphere. At least two experiments were found to demonstrate that the observed substorm activity in the region of the modification produced by the facility could be stimulated by its operation. The results of the ground- and satellite-based measurements, both in the vicinity of the "Sura" facility and in the magnetically conjugate region, confirm the conclusion about the possibility of substorm localization by this facility.

Ruzhin, Yu. Ya.; Kuznetsov, V. D.; Kovalev, V. I.; Bershadskaya, I. N.; Karabadzhak, G. F.; Plastinin, Yu. A.; Frolov, V. L.; Komrakov, G. P.; Parrot, M.

2012-06-01

220

A Mechanism to Explain the Exponential Model for Heat Production  

NASA Astrophysics Data System (ADS)

Evidence for chemical interaction between plutons and meteoric ground water and analyses of the micro-scale and mega-scale distribution of uranium and thorium suggests that thermal convection in batholith complexes mobilizes uranium and may partially explain the exponential model for the vertical distribution of crustal heat production. Investigations of the distribution of uranium, thorium, and potassium within and around eight shallow plutons show evidence for mobilization and redistribution of uranium that was not bound in resistate-refractory minerals. Induced fission track radiography of thin sections was used to reveal the mineral associations of uranium within the rocks. Shallow plutons showing evidence of significant chemical interaction with meteoric groundwater (delta 18O) contain significant amounts of uranium in secondary hydrous minerals and secondary oxides. Plutons from deeper levels in the crust that show no evidence of interaction with meteoric ground water show uranium occurs predominately in resistate minerals such as zircon, apatite, allanite, sphene, and monazite. Thorium may behave similarly. These observations suggest the hypothesis that an exponential decrease in fracture permeability with depth likely controls the volume of hydrothermal fluid activity within the crust. Soils, sediments, volcanics, metamorphic, igneous, and sedimentary rocks contain uranium and thorium in both resistate minerals and as mobile ions. A significant amount of uranium, and possibly thorium, may be assimilated from hydrothermal fluids that interact with cooling plutons in the upper crust. Metasomatism may similarly affect the distribution of uranium and thorium in metamorphic environments.

Gosnold, W.

2007-12-01

221

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

PubMed

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 41C to cause local vasodilation. In protocol 1, in normothermia, CVC did not differ among sites [ODQ, 15 3% maximum CVC (CVC(max)); DMSO, 14 3% CVC(max); Ringer, 17 6% CVC(max); P > 0.05]. During heat stress, ODQ attenuated CVC increases (ODQ, 54 4% CVC(max); DMSO, 64 4% CVC(max); Ringer, 63 4% CVC(max); P < 0.05, ODQ vs. DMSO or Ringer). In protocol 2, at 34C local temperature, CVC did not differ among sites (ODQ, 17 2% CVC(max); DMSO, 18 4% CVC(max); Ringer, 18 3% CVC(max); P > 0.05). ODQ attenuated CVC increases at 41C local temperature (ODQ, 54 5% CVC(max); DMSO, 86 4% CVC(max); Ringer, 90 2% CVC(max); 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

Kellogg, Dean L; Zhao, Joan L; Wu, Yubo; Johnson, John M

2011-02-03

222

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

Technology Transfer Automated Retrieval System (TEKTRAN)

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

223

Respiration and heat production by the inflorescence of Philodendron selloum Koch  

Microsoft Academic Search

During a 2-d sequence of anthesis, the spadices of the thermogenic arum lily, Philodendron selloum, regulated maximum temperature within a small range (3744C) by reversible thermal inhibition of respiratory heat production. This response protects the inflorescence and the attracted insects from thermal damage. Heat production by whole spadices, measured by O2 respirometry, equalled heat loss, measured by gradient layer calorimetry,

Roger S. Seymour; George A. Bartholomew; M. Christopher Barnhart

1983-01-01

224

Localized vibrational mode analysis of the resistivity and specific heat of LaB{sub 6}  

SciTech Connect

LaB{sub 6} and other hexaborides are inclusion compounds in which the rare earth or other metal ion is weakly bound and sits in an oversized ''cage'' of boron ions. Here we show that a simple model that treats the La ions as independent harmonic (Einstein) oscillators embedded in a Debye framework of boron ions successfully accounts for the anomalies in the specific heat and resistivity of LaB{sub 6}. One of the nice features of the model is that the Einstein temperature of the La atoms and the Debye temperature of the boron framework are derived from room-temperature x-ray crystallography data. This feature makes the model easy to apply to other hexaborides and other materials that can be treated as inclusion compounds. The results from this work imply that local modes are likely to be important for understanding the physical properties of all the hexaborides.

Mandrus, D.; Sales, B. C.; Jin, R.

2001-07-01

225

Localization of the gene encoding the human heat shock cognate protein, HSP73, to chromosome 11  

SciTech Connect

The heat shock cognate protein HSP73 (or HSC70) is a member of the HSP70 multigene family. This protein has several functions, including binding to nascent polypeptides to facilitate correct folding and the uncoating of clathrin-coated vesicles. Analysis of somatic cell hybrids by two-dimensional protein gel electrophoresis revealed the presence of a 73-kDa protein in two hybrids containing human chromosomes 5, 6, 9, and 11 in common. Using Western blot analysis, we demonstrate that this protein is a member of the HSP70 family and, by Southern blot analysis, that the HSP73 gene is located on human chromosome 11. Fluorescence in situ hybridization further localized HSP73 to the region 11q23.3-q25. This region is involved in a number of genetic rearrangements and is associated with several well-characterized tumors. 20 refs., 2 figs.

Tavaria, M.; Kola, I. [Monash Univ., Melbourne Victoria (Australia); Gabriele, T. [Peter MacCallum Cancer Institute, Melbourne, Victoria (Australia)] [and others

1995-09-01

226

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

227

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

USGS Publications Warehouse

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

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

1998-01-01

228

Life cycle assessment of an energy-system with a superheated steam dryer integrated in a local district heat and power plant  

SciTech Connect

Life cycle assessment (LCA) is a method for analyzing and assessing the environmental impact of a material, product or service throughout the entire life cycle. In this study 100 GWh heat is to be demanded by a local heat district. A mixture of coal and wet biofuel is frequently used as fuel for steam generation (Case 1). A conversion of the mixed fuel to dried biofuel is proposed. In the district it is also estimated that it is possible for 4000 private houses to convert from oil to wood pellets. It is proposed that sustainable solution to the actual problem is to combine heat and power production together with an improvement in the quality of wood residues and manufacture of pellets. It is also proposed that a steam dryer is integrated to the system (Case 2). Most of the heat from the drying process is used by the municipal heating networks. In this study the environmental impact of the two cases is examined with LCA. Different valuation methods shows the Case 2 is an improvement over Case 1, but there is diversity in the magnitudes of environmental impact in the comparison of the cases. The differences depend particularly on how the emissions of CO{sub 2}, NO{sub x} and hydrocarbons are estimated. The impact of the organic compounds from the exhaust gas during the drying is estimated as low in all of the three used methods.

Bjoerk, H.; Rasmuson, A. [Chalmers Univ. of Technology, Goeteborg (Sweden). Dept. of Chemical Engineering Design

1999-07-01

229

Synchronization of Sacral Skin Blood Flow Oscillations in Response to Local Heating  

PubMed Central

Local heating causes an increase in skin blood flow by activating sensory axon reflex and metabolic nitric oxide controls. It has been observed that the remote skin area without temperature changes also shows a slightly increase in blood flow. The responsible mechanism of this indirect vasodilation remains unclear. We hypothesized that the remote skin area will have enhanced synchronization of blood flow oscillations (BFO), thus inducing a vasodilatory response. We studied BFO in two sites separated 10cm of the sacral skin in 12 healthy people. Ensemble empirical mode decomposition method was used to decompose blood flow signals into a set of intrinsic mode functions (IMFs), and an IMF was selected to quantify each of myogenic, neurogenic, and metabolic modes of BFO. Then the instantaneous phase of the mode was calculated using the Hilbert transform. From the time series of phase difference between a pair of characteristic modes, we detected the epochs of phase synchronization and estimated the level of statistical significance using surrogate time series. The results showed that phase synchronization between neurogenic BFO was significantly higher in the period of the maximal vasodilation. We also observed a weak synchronization between myogenic BFO of the two skin sites. Our results suggested that synchronization of BFO may be associated with the changes in skin blood flow at the non-heated site.

Jan, Yih-Kuen; Liao, Fuyuan

2012-01-01

230

Local heat transfer on a flat surface roughened with broken ribs  

NASA Astrophysics Data System (ADS)

Detailed local mass(heat) transfer distributions are obtained for three different rib configurations, i.e., full transverse-rib, and broken ribs which may be either in-line or staggered, with pitch/rib height = 10 and 90-degree flow angle-of-attack. The study is performed using the naphthalene sublimation technique with a computer-controlled surface contour measurement system. Mass transfer characteristics for five periods are measured in both the developing and the developed regimes. The results show a fully developed periodic nature in the mass transfer starting after the second rib for all cases. The mass transfer in the first period is always the highest among all periods, and it displays greater spanwise variation than that in the developed regime. The broken rib, in general, produces lower mass transfer enhancement than the full rib. In the developed regime, the mass transfer enhancement for the full rib, broken in-line and broken staggered are 105 percent, 55 percent and 90 percent, respectively. Although the heat transfer for the broken rib may be lower, the performance index which takes pressure drop into consideration could be advantageous over the full rib.

Chyu, M. K.; Natarajan, V.

231

In-situ growth of two-terminal silicon nanowires from locally heated cantilevers  

NASA Astrophysics Data System (ADS)

Resistively heated crystalline silicon cantilevers extending over the edge of a chip offer excellent control of local growth of nanowires, without heating the entire micro-system. Besides being CMOS compatible, the cantilevers also have a rapid temperature cycling, and furthermore the freestanding cantilevers are suitable for in-situ studies of nanowire growth inside a TEM, offering the possibility of applying electrical fields to direct the growth and growing bridging wires between cantilevers thereby making two-terminal in-situ electrical measurements of nanowires possible. We have used such cantilever loops to study the growth of nanowires in-situ in UHVTEM. Epitaxial growth was observed from the crystalline cantilevers and the rapid temperature cycling ensured a very fast reaction time when crystallizing or melting the catalytic particle. The silicon wires were grown towards a cold cantilever loop, thereby forming bridging nanowires and the nanowire contact was seen to depend on the wetting ability of the gold catalytic particle to the cold cantilever. Furthermore various two-terminal measurements were performed on the bridging silicon nanowires in-situ in UHV.

Kallesoe, Christian; Ross, Frances; Wen, Chen-Yen; Molhave, Kristian; Boggild, Peter

2009-03-01

232

Application of Microwave Heating for the Production of Construction Materials.  

National Technical Information Service (NTIS)

The aim of the project was to study the replacement of classic heating processes by microwave heating. A knowledge of the microwave and thermal parameters of the materials to be treated was needed for computer simulation and optimization of the process. T...

W. Van Loock M. De Pourcq C. De Wagter

1984-01-01

233

Tvaamediaprocesser foer vaermeproduktion. (Two-media cycles for heat production).  

National Technical Information Service (NTIS)

One way to increase efficiency in converting chemical energy to electricity and heat is to develop new thermodynamic working cycles. In the refrigeration technology and in the heat pump technology, mixtures of two or more components have been used as work...

J. Murray E. Olsson G. Svedberg

1990-01-01

234

Nuclear localization of the testis determining gene product SRY  

Microsoft Academic Search

We have studied the expression of the hu- man SRY protein (termed p27SRY) in two different cell lines by using specific antibodies. Confocal mi- croscopy enabled us to localize p27SRY precisely in the nucleus in a discrete punctuate pattern. Further- more, through microinjection experiments, we have demonstrated that the localization of the p27SRY pro- tein into the nucleus was an

Francis Poulat; Franck Girard; Marie-Pierre Chevron; Catherine Goz; Xavier Rebillard; Bernard Calas; Ned Lamb; Philippe Berta

1995-01-01

235

Detailed measurements of local heat transfer coefficient in the entrance to normal and inclined film cooling holes  

SciTech Connect

The local heat transfer inside the entrance to large-scale models of film cooling holes has been measured using the transient heat transfer technique. The method employs temperature-sensitive liquid crystals to measure the surface temperature of large-scale perspex models. Full distributions of local Nusselt number were calculated based on the cooling passage centerline gas temperature ahead of the cooling hole. The circumferentially averaged Nusselt number was also calculated based on the local mixed bulk driving gas temperature to aid interpretation of the results, and to broaden the potential application of the data. Data are presented for a single film cooling hole inclined at 90 and 150 deg to the coolant duct wall. Both holes exhibited entry length heat transfer levels that were significantly lower than those predicted by entry length data in the presence of crossflow. The reasons for the comparative reduction are discussed in terms of the interpreted flow field.

Gillespie, D.R.H.; Byerley, A.R.; Ireland, P.T.; Wang, Z.; Jones, T.V. [Univ. of Oxford (United Kingdom). Dept. of Engineering Science; Kohler, S.T. [Rolls Royce, Bristol (United Kingdom)

1996-04-01

236

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

237

Local entropy production in turbulent shear flows: a high-Reynolds number model with wall functions  

Microsoft Academic Search

Entropy production in incompressible turbulent shear flows of Newtonian fluids is analysed systematically and incorporated into a CFD code. There are four different mechanisms of entropy production: dissipation in a mean and fluctuating velocity field and heat flux in a mean and fluctuating temperature field. Based on asymptotic considerations wall functions for the four production terms are developed. These wall

Fabian Kock; Heinz Herwig

2004-01-01

238

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.

Not Available

1990-12-01

239

Effect of trailing-edge ejection on local heat (mass) transfer in pin fin cooling channels in turbine blades  

Microsoft Academic Search

Experiments are conducted to study the local heat transfer distribution and pressure drop in a pi fin channel that models the cooling passages in modern gas turbine blades. The detailed heat\\/mass transfer distribution is determined via the napthalene sublimation technique for flow through a channel with a 16-row, staggered 3 x 2 array of short pin fins (with a height-to-diameter

R. D. McMillin; S. C. Lau

1994-01-01

240

Development-dependent differences in intracellular localization of stress proteins (hsps) in rainbow trout, Oncorhynchus mykiss, following heat shock  

Microsoft Academic Search

Using antibodies specific for salmonid fish, we have determined the intracellular localization of hsp70, hsc70 and hsp90 before and after an acute heat shock in juvenile and mature rainbow trout. We found that both hsp70 and hsp90 were primarily located outside the nucleus in both the liver and the heart of juvenile and mature fish and heat shock resulted in

Jillian L. Rendell; Stephanie Fowler; Amanda Cockshutt; Suzanne Currie

2006-01-01

241

Characteristic Properties of a Locally Produced Paraffinic Oil and Its Suitability as a Heat-Transfer Fluid  

Microsoft Academic Search

The thermo-physical properties of a paraffinic mineral oil produced in a local refinery were experimentally determined over a wide temperature range of 30360C to determine its suitability for use as a heat-transfer fluid. The effect of temperature on the physical characteristics of the oil and two synthetic organic heat transfer fluids was evaluated at high temperatures (180360C). Comparison of the

L. O. Oyekunle; A. A. Susu

2005-01-01

242

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

SciTech Connect

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

Pechersky, M.J.

2000-02-23

243

Images of new product success: a case study in search of local validity  

Microsoft Academic Search

Purpose This paper aims to measure new product success within a Dutch mailing company and to hypothesize that there exists no definition of new product success which is generally applicable, or valid in all circumstances. It seeks to opine that the best that can be achieved is a local definition: a definition valid only in a specific local context.

Derk Jan Kiewiet; Marjolein C. Achterkamp

2008-01-01

244

The Relative Importance of Search versus Credence Product Attributes: Organic and Locally Grown  

Microsoft Academic Search

Organic foods and local foods have come to the forefront of consumer issues, due to concerns about nutrition, health, sustainability, and food safety. A conjoint analysis experiment quantified the relative importance of, and trade-offs between, apple search and experience attributes (quality\\/blemishes, size, flavor), credence attributes (conventional vs. organic production method, local origin vs. product of USA vs. imported), and purchase

Ferdinand F. Wirth; John L. Stanton; James B. Wiley

2011-01-01

245

Production of neutral atoms by pulsed laser heating  

Microsoft Academic Search

Sodium and thallium surfaces were heated in vacuum by a short intense pulse from a CO2 TEA laser. The time-dependent emission of neutral atoms following the laser pulse was measured in the density range 10111012 atoms\\/cm3 by monitoring the absorption from a beam of resonance light. The temperature of the metal surface and the depth of heating after the laser

A. T. Prengel; J. Dehaven; E. J. Johnson; P. Davidovits

1977-01-01

246

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

PubMed

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

2011-12-07

247

A New Facility for Measurements of Three-Dimensional, Local Subcooled Flow Boiling Heat Flux and Related Critical Heat Flux for PFCs  

SciTech Connect

In the development of plasma-facing components for fusion reactors and high-heat-flux heat sinks (or components) for electronic applications, the components are usually subjected to a peripherally nonuniform heat flux. Even if the applied heat flux is uniform in the axial direction (which is unlikely), both intuition and recent investigations have clearly shown that both the local heat flux and the eventual critical heat flux (CHF) in this three-dimensional (3-D) case will differ significantly from similar quantities found in the voluminous body of data for uniformly heated flow channels. Although this latter case has been used in the past as an estimate for the former case, more study has become necessary to examine the 3-D temperature and heat flux distributions and related CHF. Work thus far has shown that the nonuniform peripheral heat flux condition enhances CHF in some cases.To avoid the excess costs associated with using electron or ion beams to produce the nonuniform heat flux, a new facility was developed that will allow 3-D conjugate heat transfer measurements and two-dimensional, local subcooled flow boiling heat flux and related CHF measurements.The configurations under study for this work consist of (a) a nonuniformly heated cylinder-like test section with a circular coolant channel bored through the center and (b) a monoblock that is a square cross-section parallelepiped with a circular drilled flow channel along the channel centerline. The theoretical or ideal cylinder-like test section would be a circular cylinder with half (-90 to 90 deg) of its outside boundary subjected to a uniform heat flux and the remaining half insulated. For the monoblock, a uniform heat flux is applied to one of the outside surfaces, and the remaining surfaces are insulated. The outside diameter of the cylinder-like test section is 30.0 mm, and its length is 200.0 mm. The monoblock square is 30.0 mm long. The inside diameter of the flow channel for both types of test sections is 10.0 mm. Water is the coolant. The inlet water temperature can be set at any level in the range from 26.0 to 130.0 deg. C, and the exit pressure can be set at any level in the range from 0.4 to 4.0 MPa. Thermocouples were placed at 48 locations inside the solid cylinder-like or monoblock test section to obtain 3-D wall temperature variations and related local heat flux. Finally, the mass velocity can be set at any level in the range from 0.4 to 10.0 Mg/m{sup 2}.s for the 10.0-mm-diam channel.

Boyd, Ronald D. Sr.; Cofie, Penrose; Li Qingyuan; Ekhlassi, Ali A

2002-01-15

248

Critical heat flux experiments with a local hot patch in an internally heated annulus (LWBR development program)  

Microsoft Academic Search

Critical heat flux experiments were conducted for upflow of water in a vertical 84 inch annular flow channel, 0.303 inch heated I.D. and 0.500 inch unheated O.D. Test data were obtained at pressures from 1200 to 2000 psia, mass velocities from 0.25 x 10⁶ to 2.8 x 10⁶ lb\\/hr-ft² and inlet temperatures ranging from 200 to 600°F. Three different test

E. P. Mortimore; S. G. Beus

1979-01-01

249

Contribution a l'Etude Locale et Temporelle de la Combustion et des Transferis Thermiques dans UN Moteur Diesel a Injection Directe (Local and Temporal Study of the Combustion and Heat Transfer in a Direct Injection Diesel Engine).  

National Technical Information Service (NTIS)

Local and instantaneous combustion of heat transfer in a direct injection industrial diesel engine was studied. Local combustion was calculated by measuring diesel flame monochromatic radiation. A two colored optical method was used to obtain gas temperat...

H. X. Quoc

1991-01-01

250

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)

2008-07-02

251

Ecological entrepreneurship: sustainable development in local communities through quality food production and local branding  

Microsoft Academic Search

The paper explores the importance of specialised networks in shaping local\\/regional responses to the deepening crisis of conventional agriculture in the EU, as well as potentially creating a more sustainable platform for rural development. The emphasis will be on the problem-solving aspects of network creation and maintenance within a broader and not necessarily supportive competitive and regulatory environment. This involves

Terry Marsden; Everard Smith

2005-01-01

252

Statistical Mechanics of Entropy Production: Gibbsian hypothesis and local fluctuations  

Microsoft Academic Search

It is argued that a Gibbsian formula for the space-time distribution of microscopic trajectories of a nonequilibrium system provides a unifying framework for recent results on the fluctuations of the entropy production. The variable entropy production is naturally expressed as the time-reversal symmetry breaking part of the space-time action functional. Its mean is always positive. This is both supported by

Christian Maes

2001-01-01

253

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

ERIC Educational Resources Information Center

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

Wilson, Geoff A.; Whitehead, Ian

2012-01-01

254

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

NASA Astrophysics Data System (ADS)

A global reso lution surface current and surface heat tr ansport product is available at the Centre de Topographie des O cans et de l'Hydrosphre (CTOH) . The surface curren t field is calculated from a co mbination of altimetric geostrophic curren t anomalies, Qu ickscat Ek man curren ts at 15 m dep th and a climatolog ical mean geostrophic cir culation. The velocity field in th e equ atorial band is adapted from the equ atorial adjustment d escr ibed by [1]. These surface curren ts are co mbined with microw ave sea surface temper atur e (SST) d ata from the comb ined global TMI/A MSR-E SST product. A preliminary an alysis shows how the comb ined product can be used to calcu late h eat transports and heat budgets, and investig ate the relativ e roles of eddy heat transport, mean geostrophic heat tr ansport and Ekman heat tr ansport.

Sudre, J.; Morrow, R.

2006-07-01

255

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

NASA Astrophysics Data System (ADS)

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

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

2008-09-01

256

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

257

Heat and moisture production of layers in constant and dynamic environments  

SciTech Connect

Heat and moisture production of layers under constant and cyclic environments were measured and compared to published values. These data were obtained from two environmental chambers each with a capacity for 48 caged birds. Sensible heat for the constant thermal environment compared favorably with published values. Latent heat differed from published values, this difference was attributed to evaporation from fecal matter. Preliminary results from cyclic environments are presented.

Dubensky, H.J.; Puri, V.M.; Manbeck, H.B.

1986-01-01

258

TRANSIENT THERMAL STRESSES DUE TO A LOCAL SOURCE OF HEAT MOVING OVER THE SURFACE OF AN INFINITE ELASTIC SLAB  

Microsoft Academic Search

A solution is given for the transient thermal stresses due to a local source of heat that moves at constant speed over the surface of an infinite elastic slab. The transient temperature distribution is obtained by means of the Fourier and Laplace transforms, and the associated thermal stresses are obtained by making use of the thermoelastic displacement function and the

Naobumi Sumi; Richard B. Hetnarski; Naotake Noda

1987-01-01

259

Potential for Evaporative Cooling during Heat Stress Periods in Pig Production in Portugal (Alentejo)  

Microsoft Academic Search

Hot weather adversely affects the performance of pig production. Under heat stress, penalties to efficient performance, production, reproduction, feed conversion, health and welfare of animals can be severe. In the Alentejo region of Portugal, the main losses in pig production result from the summer dry period, characterized by high air temperature and low relative humidity.For this study, hourly air temperature

E. M. Lucas; J. M. Randall; J. F. Meneses

2000-01-01

260

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

NASA Astrophysics Data System (ADS)

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

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

2012-02-01

261

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

PubMed Central

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

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

1993-01-01

262

Estimating local instabilities for irregular flows in the differentially heated rotating annulus  

NASA Astrophysics Data System (ADS)

In stable flows, transient growth of 'non-normal' modes can lead to turbulence. Usually, non-normal modes are computed from linearized model equations [1]. However, for some problems the proper set of equations is unknown, or unhandy for the purpose of finding non-normal modes. Therefore it is proposed to estimate non-normal modes from data alone, without using the model equations. Crucial for such an estimation is a good guess of the linear system matrix for the flow under consideration. Such a guess can be obtained following the approach by [2] discussed in the context of climate analysis. In the present paper a simple test case will be presented that demonstrates the suitability of the approach. Subsequently, the method is applied to temperature data from a differentially heated rotating annulus, a laboratory model that covers features of the large-scale atmospheric circulation [3]. The method proposed might help to gain insight into the spatial structures of local instability in annulus flows.

Harlander, U.; Faulwetter, R.; Alexandrov, K.; Egbers, C.

263

Hydrogen production from water utilizing solar heat at high temperatures  

Microsoft Academic Search

Possibilities of producing hydrogen and oxygen from water utilizing solar heat at high temperatures are investigated. The process of direct thermal decomposition of water is studied using a conceptual model. It is shown that the thermodynamic requirements for the direct thermal decomposer are difficult to realize from the structural viewpoint and that existing separation methods are not applicable for such

T. Nakamura

1977-01-01

264

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

National Technical Information Service (NTIS)

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

L. Ljung

1980-01-01

265

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

Technology Transfer Automated Retrieval System (TEKTRAN)

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

266

Respiration energetics of marine algae for total heat production and some features of photosynthesis  

Microsoft Academic Search

A preliminary study of microplankton biothermodynamics in Sevastopol Bay showed an endothermic effect at the end of the first day of measuring the heat production. Measuring the heat dissipation of dark reactions in metabolism of some seaweeds, using a microcalorimeter, determined the analogous endothermic effect approximately within the same time period of measurements. One can observe that energy of consumption

G. V. Barinov; A. S. Lopukhin; R. P. Trenckenshu

1998-01-01

267

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

Technology Transfer Automated Retrieval System (TEKTRAN)

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

268

Arabidopsis HIT4 encodes a novel chromocentre-localized protein involved in the heat reactivation of transcriptionally silent loci and is essential for heat tolerance in plants.  

PubMed

The Arabidopsis mutant heat-intolerant 4-1 (hit4-1) was isolated from an ethyl methanesulphonate-mutagenized M2 population on the basis of its inability to withstand prolonged heat stress (4 days at 37C). Further characterization indicated that hit4-1 was impaired specifically in terms of basal but not acquired thermotolerance. Map-based cloning revealed that the HIT4 gene encoded a plant-specific protein for which the molecular function has yet to be studied. To investigate the cellular role of HIT4 and hence elucidate better its protective function in heat tolerance in plants, a GFP-HIT4 reporter construct was created for a protoplast transient expression assay. Results showed that fluorescently tagged HIT4 was localized to the chromocentre, a condensed heterochromatin domain that harbours repetitive elements for which transcription is normally suppressed by transcriptional gene silencing (TGS). DAPI-staining analysis and FISH with a probe that targeted centromeric repeats showed that heat-induced chromocentre decondensation was inhibited in nuclei of hit4-1 subjected to direct heat treatment, but not in those that were allowed to acquire thermotolerance. Moreover, heat reactivation of various TGS loci, regardless of whether they were endogenous or transgenic, or existed as a single copy or as repeats, was found to be attenuated in hit4-1. Meanwhile, the levels of transcripts of heat shock protein genes in response to heat stress were similar in both hit4-1 and wild-type plants. Collectively, these results demonstrated that HIT4 defines a new TGS regulator that acts at the level of heterochromatin organization and is essential for basal thermotolerance in plants. PMID:23408827

Wang, Lian-Chin; Wu, Jia-Rong; Chang, Wei-Ling; Yeh, Chin-Hui; Ke, Yi-Ting; Lu, Chun-An; Wu, Shaw-Jye

2013-02-13

269

Adjustments in metabolic heat production by squirrel monkeys exposed to microwaves  

SciTech Connect

The basic fact that microwave exposure can lower metabolic heat production has been previously demonstrated for the mouse by Ho and Edwards (1977) and for the rat by Phillips et al. (1975). The general conclusion drawn from both studies was that the metabolic reduction produced by microwave exposure was dose dependent. The present study extends the investigation into the effects of microwave exposure on metabolic heat production to a primate, the squirrel monkey. When squirrel monkeys are restrained in cool environments, body temperature is regulated by an increase in metabolic heat production. The results of the current study demonstrate that either brief or prolonged whole-body exposure to a microwave field will cause a reduction of this elevated heat production by an amount directly related to the microwave energy absorbed.

Adair, E.R. (John B. Pierce Foundation Laboratory, New Haven, CT); Adams, B.W. (Yale University, New Haven, CT)

1982-04-01

270

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

National Technical Information Service (NTIS)

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

L. Ljung

1982-01-01

271

Radiogenic Heat Production in the Moon: Constraints from Plagioclase-Melt Trace Element Partitioning Experiments  

NASA Astrophysics Data System (ADS)

We estimate radiogenic heat production in the Moon, and its depth distribution, by combining highland surface concentrations of U, Th, and K with experimental constraints on the distribution of these elements between anorthositic plagioclase and melt.

de Vries, J.; van Westrenen, W.; van den Berg, A.

2012-03-01

272

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

SciTech Connect

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

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

2000-04-04

273

Molten salt techniques for excess heat production and the loading issue  

Microsoft Academic Search

An interesting molten salt technique for elevated-temperature excess heat production has recently been reported, promising great potential for commercial applications. This technique shows improved efficiency due to a high-temperature operation, high-grade heat production, and fast kinetics in metal-hydrogen reactions. This paper gives an overview of our work in molten salt electrolysis experiments using Ti and Pd as anodes in deuteride

Bor Y. Liaw

1994-01-01

274

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

PubMed

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

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

2001-06-26

275

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 Wm-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

276

Temperature and heat production patterns inside organism clusters  

NASA Astrophysics Data System (ADS)

Clustering of organisms under cold air temperature conditions is modelled with a finite-difference method. Metabolic functions of temperature are used to simulate completely ectothermic, completely endothermic, and other organisms. To adequately match real conditions, the core temperature is kept constant at a high level, while the periphery of the organism cluster is assigned a lower temperature representing the cold conditions under which clustering is observed for organisms. The numerical model reasonably predicts the observed temperature distribution in honeybee clusters. The results do not support suggestions that organisms could overheat in the core of a cluster if they do not use thermoregulatory mechanisms to cool down. Endothermic organisms are not as efficient as ectothermic ones in heating a cluster core temperature to a given level. The general ectothermic metabolic rate function exhibited one of the highest efficiencies for heating the cluster.

Kyaw Tha Paw, U.

1988-06-01

277

Convective heat transfer coefficient model for spherical products subject to hydrocooling  

SciTech Connect

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

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

1996-09-01

278

Production of neutral atoms by pulsed laser heating  

Microsoft Academic Search

Sodium and thallium surfaces were heated in vacuum by a short intense pulse from a CO2 TEA laser. The time-dependent emission of neutral atoms following the laser pulse was measured in the density range 10 to the 11th to 10 to the 12th atoms\\/cu cm by monitoring the absorption from a beam of resonance light. The temperature of the metal

A. T. Prengel; J. Dehaven; E. J. Johnson; P. Davidovits

1977-01-01

279

ALUMINUM PRODUCTION USING HIGH-TEMPERATURE SOLAR PROCESS HEAT  

Microsoft Academic Search

The primary metals industry is one of the most energy intensive in the manufacturing sector, and is consequently also a major source of climate-altering gases. The replacement of electrolysis or electrothermal processes with direct reduction processes using high-temperature solar process heat may well be economical, especially when the costs of CO2 emission are included in the analysis. In particular, aluminum

JEAN P. MURRAY

1999-01-01

280

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

281

Increased local cytokine production at culprit superficial femoral artery plaques.  

PubMed

Characterization of local inflammation at culprit superficial femoral artery (SFA) stenosis has not been studied. We hypothesized that arterial cytokine concentrations would be greater at sites of stenosis. Twenty patients with ?50% angiographic stenosis of the SFA had blood drawn just proximal to the lesion and from a contralateral site free of disease. A microplate immunoassay was used to determine the concentrations of 42 distinct cytokines and growth factors. Exact conditional logistic analysis was used to compare measures at the two sites with interaction terms describing clinical factors used to identify difference mediators. Interaction terms identified clinical factors that could predict cytokine levels. The concentrations of soluble CD40 ligand (sCD40L; mean 212 and 177pg/ml, p=0.01) and tumor necrosis factor beta (TNF-B; mean 16.6 and 15.9pg/ml, p=0.04) were increased immediately proximal to areas of stenosis. Factors associated with greater concentrations at sites of stenosis were bilateral ankle-brachial index ?0.90 (p=0.04), no statin use (p=0.02), claudication (p=0.03), low leukocyte count (p=0.03), absence of limb ischemia (p=0.04) and lack of aspirin or clopidogrel therapy (p?0.06). Greater concentrations of sCD40L and TNF-B at sites of stenosis suggest that these cytokines play a role in the pathogenesis of symptomatic SFA disease. Our results also suggest that statin, aspirin and clopidogrel therapy may attenuate localized inflammation in the SFA, though due to a small sample size and the use of multiple comparisons across groups, these findings can be viewed as hypothesis generating only. In conclusion, selected cytokines are heightened at culprit SFA lesions and inflammation may be modulated by statin and antiplatelet therapy. PMID:23299818

Donaldson, Cameron W; Schneider, David J; Bertges, Daniel J; Adams, Julie E; Elgharib, Nader Z; Mueller, Enkhtuyaa L; Prabhu, William; Ashikaga, Taka; Dauerman, Harold L

2013-10-01

282

Thermal plumes and electric potentials generation in a porous medium locally heated from below  

NASA Astrophysics Data System (ADS)

The mechanism of convection and electric phenomena around an isolated heat source in a fluid saturated porous media is of interest in geothermal processes and volcanology. Laboratory and numerical experiments of transient convective flows and induced electric potentials in a porous layer with a local bottom heat source are reported. Laboratory characterization of fluid flow in porous media has a severe limitation by non-transparent nature of the media comparing to the case for a single fluid. In this study as for the temperature characterization, we utilized gridded thermocouples for multiple temperature measurement. As for the flow characterization, we set multiple electrodes to measure flow-induced potential. Axisymetric laminar plumes were experimentally generated by a small electric heater in a tank filled with water-saturated glass beads. We determined the spread of the plume with horizontally-gridded thermocouples, while vertical sets were used to characterize the time evolution of the plume ascent. Vertically-aligned electrodes along the central line exhibit large positive increase associated with plume ascent. The magnitude is consistent with the temperature increase and applied power. To understand the development of the plume, 2D-3D numerical simulations have been performed for the same situations of laboratory experiments. The flow pattern is investigated for Rayleigh numbers up to 8000. Plumes ascent in two different regimes. For Ra<1200, the velocity of the plume head slowly decreases during the ascension in the porous medium (consistent with Elder, 1967). For Ra>1200, the velocity increases owing to the development of the thermal boundary layer, remains nearly constant during the rise, before decreasing at the top of the tank. Finally, the electric potentials induced by the development of the plume are analyzed. It is shown that the signal initially decreases when the plume is detaching itself from the bottom, but largely increases during the ascension of the water, which is systematically observed in experimental results. We consider flow-induced potential as a good experimental probe for fluid flow characterization in porous media. This study is the first step to further experimental and numerical works on convective cells generation and induced electric potentials in a stratified porous medium.

Antoine, R.; Kurita, K.

2010-12-01

283

HEAT STRESS AS IT AFFECTS ANIMAL PRODUCTION l  

Microsoft Academic Search

Summary It is well documented that the stress of hot environments lowers productive and reproduc- tive efficiency in farm animals. Likewise, research information is available to aid in the management of livestock in such adverse conditions. However, practical methods to achieve the desired levels of productive and reproductive performance are lacking. Summer forages that will support a high level of

J. W. Fuquay

2010-01-01

284

Consistent pattern of local adaptation during an experimental heat wave in a pipefish-trematode host-parasite system.  

PubMed

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 18C. However, the proportion of the innate immune cells (monocytes) was higher in the 18C 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

2012-01-27

285

Thermophilic biohydrogen production by an anaerobic heat treated-hot spring culture  

Microsoft Academic Search

Batch experiments were conducted to investigate the thermophilic biohydrogen production using an enrichment culture from a Turkish hot spring. Following the enrichment, the culture was heat treated at 100C for 10min to select for spore-forming bacteria. H2 production was accompanied by production of acetate, butyrate, lactate and ethanol. H2 production was associated by acetatebutyrate type fermentation while accumulation of lactate

Dogan Karadag; Annukka E. Mkinen; Elena Efimova; Jaakko A. Puhakka

2009-01-01

286

The Response of Balanced Hurricanes to Local Sources of Heat and Momentum.  

NASA Astrophysics Data System (ADS)

Eliassen's (1951) diagnostic technique is used to calculate the secondary circulation induced by point sources of heat and momentum in balanced, hurricane-like vortices. Scale analysis reveals that such responses are independent of the horizontal scale of the vortex. Analytic solutions for the secondary circulation are readily obtained in idealized barotropic vortices, but numerical methods are required for more realistic barotropic and baroclinic vortices. For sources near the radius of maximum wind, the local, two-dimensional, streamfunction dipole response of Eliassen is modified by both the spatial variations of the vortex structure and the influences of boundary conditions.The secondary flow advects mean-flow buoyancy and angular momentum and thus leads to a slow evolution of the vortex structure. In weak systems (maximum tangential wind <35 m s1), the restraining influences of structure and boundaries lengthen the time scale of the vortex evolution. In stronger vortices, the horizontal scale of the response is smaller, the restraining influences are less important, and the evolution is faster. When the maximum wind exceeds 35 m s1, recirculation of air within the vortex core tends to form an eye.The most rapid temporal changes in tangential wind lie inside the eye, where the horizontal gradients of angular momentum are strongest. In most cases, the tangential wind increases most rapidly just inside the radius of maximum wind and decreases near the central axis of the vortex. This effect leads to contraction of the wind maximum as the vortex intensifies. The present results are compared with observations and other theoretical mutts.

Shapiro, Lloyd J.; Willoughby, Huch E.

1982-02-01

287

Production and localization of recombinant pharmaceuticals in transgenic seeds.  

PubMed

Among the many plant-based production systems that have been developed for pharmaceutical proteins, seeds have the useful advantage of accumulating proteins in a relatively small volume, and recombinant proteins are very stable in dry seeds allowing long-term storage and facilitating distribution before processing.To take full advantage of the natural ability of endosperm cells to store large amounts of protein in a protected subcellular environment, it is useful to target recombinant proteins to appropriate storage organelles. In this chapter, we describe the distinct types of protein storage organelles in the cereal endosperm and a protocol for the detection of recombinant proteins in these organelles by immunofluorescence and immunogold labelling.The use of food and feed crops for the production of pharmaceutical proteins such as edible vaccines implies the need for strict separation of the transgenic seeds from the food and feed chain. For improved traceability visual markers may be co-expressed with the gene of interest in engineered seeds. DsRed is one example for a fluorescent protein that can be detected with high sensitivity using low tech equipment. We therefore describe the generation of transgenic maize plants expressing DsRed in a constitutive manner, and we point out the advantages of using this marker during the process of transformation and selection of plant tissue and later during breeding of transgenic lines into elite germplasm. PMID:19183894

Rademacher, Thomas; Arcalis, Elsa; Stoger, Eva

2009-01-01

288

Production of gluconic Acid by some local fungi.  

PubMed

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-Sherbeny, G A; El-Esawy, A E; Sheriff, Y M M M

2006-03-31

289

Production of Gluconic Acid by Some Local Fungi  

PubMed Central

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

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

2006-01-01

290

Molten salt techniques for excess heat production and the loading issue  

NASA Astrophysics Data System (ADS)

An interesting molten salt technique for elevated-temperature excess heat production has recently been reported, promising great potential for commercial applications. This technique shows improved efficiency due to a high-temperature operation, high-grade heat production, and fast kinetics in metal-hydrogen reactions. This paper gives an overview of our work in molten salt electrolysis experiments using Ti and Pd as anodes in deuteride melts, in which substantial excess heat was found. This paper also presents some preliminary results using Ni and steel as anodes for electrolysis in hydride melts. Because the deuterium loading in Pd is considered a critical parameter for excess heat production, this paper will discuss this aspect and extend to elevated-temperature conditions.

Liaw, Bor Y.

1994-07-01

291

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

NASA Astrophysics Data System (ADS)

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

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

2012-11-01

292

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

PubMed

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

Attoh

2000-05-01

293

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

PubMed

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

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

2012-05-01

294

Hydrostatic and Geostrophic Adjustment in a Compressible Atmosphere: Initial Response and Final Equilibrium to an Instantaneous Localized Heating.  

NASA Astrophysics Data System (ADS)

The initial and steady-state response of a compressible atmosphere to an instantaneous, localized heat source is investigated analytically. Potential vorticity conservation removes geostrophic and hydrostatic degeneracy and provides a direct method for obtaining the steady-state solution. The heat source produces a vertical potential vorticity dipole that induces a hydrostatically and geostrophically balanced cyclone anticyclone structure in the final state. For a typical deep mesoscale heating, the net displacements required for the adjustment to the final steady state include a small, O(100 m) ascent of the core of the heated air with weak far-field descent and a large, O(10 km) outward/inward lateral displacement at the top/base of the heating.The heating initially generates available elastic and potential energy. The energy is then exchanged between kinetic, elastic, potential, and acoustic and gravity wave energy. In the final state, after the acoustic and gravity wave energy has dispersed, the remaining energy is partitioned between kinetic, and available potential and elastic energy. The fraction of wave energy increases with increasing horizontal wavenumber.The effect of several vertical boundary conditions is assessed. It is shown that a rigid lid suppresses the vertical expansion of the heated layer and reduces the fraction of wave energy. The impact of the rigid lid on the steady-state solution is maximized for the horizontal wavenumber zero solution and when the heating takes place close to the rigid upper boundary.The compressible solution is used as a prototype for comparing and evaluating several compressibility approximations: the anelastic, pseudo-incompressible, and modified-compressible approximations. The anelastic model omits the available elastic energetics entirely, but the pseudo-incompressible and modified-compressible models omit either its generation or storage. The result is an ambiguous projection of heating energy onto the remaining energy terms. The errors associated with these approximations are only significant on synoptic scales. Furthermore, the modified-compressible set does not conserve potential vorticity globally.The initial response to the heating differs for each approximation. Although the initial compressible response consists of pressure and potential temperature anomalies confined to the heated layer, the modified-compressible atmosphere generates density and potential temperature anomalies but no pressure anomaly. The anelastic atmosphere undergoes an instantaneous acoustic adjustment in which pressure and density anomalies exist inside and outside of the heated region. The pseudo-incompressible atmosphere generates an instantaneous, net divergence characterized by a residual velocity remaining after the heating and an instantaneous pulse in the pressure and velocity fields.


Chagnon, Jeffrey M.; Bannon, Peter R.

2001-12-01

295

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

SciTech Connect

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

Dr. Ronald D. Boyd

2000-07-01

296

Impact Research of Process Parameters on Sink Index of Rapid Heat Cycle Molding Products  

Microsoft Academic Search

Taking the independently designed in-vehicle Bluetooth high glossy product as an example, in combination with the Taguchi experiment and the simulation technology, the experimental research of the impact of Rapid Heat Cycle Molding(RHCM) process on the sink mark of the product is conducted through the introduction of interference factors. The results show that the technical characteristics of high mold temperature

Sun Ling; Liu Donglei

2010-01-01

297

Study of heat production and transfer in shredded tires  

NASA Astrophysics Data System (ADS)

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

Sellassie, Kassahun G.

298

Fossil fuels substitution by the solar energy utilization for the hot water production in the heating plant Cerak in Belgrade  

Microsoft Academic Search

The main objective of this paper is to evaluate energy and environmental benefits of the large-scale solar heating system connection with district heating system. The assessment of fossil fuels substitution by the solar energy for the hot water production for domestic use, during the summer period, is done. Hot water for district heating and domestic use is produced in heating

V. Turanjanin; V. Baki?; M. Jovanovi?; M. Pezo

2009-01-01

299

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

Microsoft Academic Search

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

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

2005-01-01

300

Transient geotherms in Archean continental lithosphere: New constraints on thickness and heat production of the subcontinental lithospheric mantle  

Microsoft Academic Search

Because of its large thickness and thermal relaxation time, Archean lithosphere cannot be in thermal equilibrium with the instantaneous rate of heat production in the lithospheric mantle and heat supplied to its base. Comparison of xenolith (P,T) data with time-dependent thermal models allows constraints on lithosphere thickness, in situ heat production in the lithospheric mantle and time changes of basal

C. Michaut; C. Jaupart; D. R. Bell

2007-01-01

301

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

302

Consumer Preferences for Locally Made Specialty Food Products Across Northern New England  

Microsoft Academic Search

Does willingness to pay a premium for local specialty food products differ between consumers in Maine, New Hampshire, and Vermont? Two food categories are investigated: low-end ($5) and high-end ($20) products. Premia estimates are compared across states and across base prices within states using dichotomous choice contingent valuation methods. Results suggest that the three states of northern New England have

Kelly L. Gii-aud; Craig A. Bond; Jennifer Keeling Bond

2005-01-01

303

Competitiveness, Local Production Systems and Global Commodity Chains in the Music Industry: Entering the US Market  

Microsoft Academic Search

Power D. and Hallencreutz D. (2007) Competitiveness, local production systems and global commodity chains in the music industry: entering the US market, Regional Studies41, . This paper traces the principal channels and barriers that determine the conditions of access for musical products entering the US music market. It is shown that music distribution channels and retail environments exist in a

Dominic Power; Daniel Hallencreutz

2007-01-01

304

Effect of Atropine on Local Skin Wettedness and Sensible Heat Loss.  

National Technical Information Service (NTIS)

This study examined arm skin wettedness (w) and dry heat loss (arm R+C) responses during atropine injection (2 mg im, vastis lateralis) or saline injection in heat acclimated subjects. Six male subjects dressed in shorts and sneakers, each exercised (1h t...

R. R. Gonzalez M. A. Kolka L. A. Stephenson

1984-01-01

305

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

306

Intramitochondrial localization of the main 70-kDa heat-shock cognate protein in Drosophila cells.  

PubMed

The main heat shock cognate protein (hsc) of 70 kDa in Drosophila, hsc 4, was localized in cultured cells using a specific affinity-purified antibody and colloidal gold immunoelectron microscopy. This constitutively expressed member of the heat shock protein (hsp) 70 family is found in the cytosol, in mitochondria, and in the nucleus of unstressed cells. The identity of hsc 4 in these three cellular compartments was confirmed by two-dimensional gel immunoblots and partial proteolytic digestion patterns. In mitochondria, the colloidal gold particles are observed in close proximity to or on the inner membranes. The intramitochondrial localization of this hsc was confirmed by density gradient purification and by resistance of hsc 4 to externally added trypsin. In the nucleus, the labeling is found on nucleo-plasmic perichromatin RNP fibrils and is not detected in the nucleolus. Heat shock induces an intracellular redistribution of hsc 4 with an enrichment in the nucleus. The localization of this hsc in different cellular compartments is consistent with the previously suggested functions of some members of this family of proteins in basic cellular processes such as protein folding. Moreover, the present data suggests that the main constitutively expressed member of the hsp 70 family, hsc 4, functions both within the mitochondrial compartment and in the nucleus. PMID:8344382

Carbajal, E M; Beaulieu, J F; Nicole, L M; Tanguay, R M

1993-08-01

307

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.

Lonnbro, P; Hellstrand, P

1991-01-01

308

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; Andr Bontemps; Alain Marchal; Franois Werkoff

2007-01-01

309

Experimental investigation into the effects of rotating and static bolts on both windage heating and local heat transfer coefficients in a rotor/stator cavity  

NASA Astrophysics Data System (ADS)

Experiments are carried out on the following combinations of bolts: single row rotating, single row static, double row rotating, and combined rotating and static. Different sizes of bolts were tested as well as variation in pitching and the effects of various bolt shields. The adiabatic wall temperature was measured locally at various positions on the rotor surface both between adjacent bolts and at different pitch circle diameters. In the course of the testing, a considerable reduction in windage due to the shape of the disc surface near the rim was measured. This study describes the experimental technique used and presents a selection of the windage and heat transfer results.

Millward, J. A.; Robinson, P. H.

1989-06-01

310

Renewable Power Production of Moderate Temperature Geothermal Heat Using Air Conditioning Hardware  

Microsoft Academic Search

A system has been developed to enable cost-effective power production from moderate temperature liquid heat sources, defined as temperatures less than 125 0C. Examples of such heat sources are the warm water from geothermal wells, the warm water\\/oil mixture from active or abandoned oil and gas wells and the warm jacket water from reciprocating engines that is normally cooled in

JOOST J. BRASZ

311

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

Microsoft Academic Search

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

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

1981-01-01

312

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

NASA Astrophysics Data System (ADS)

Coastal polynyas are areas in an ice-covered ocean where the ice cover is exported, mostly by off-shore winds. The resulting reduction of sea ice enables an enhanced ocean-atmosphere heat transfer. Once the water temperatures are at the freezing point, further heat loss induces sea ice production. The heat exchange and ice production in coastal polynyas in the southwestern Weddell Sea is addressed using the Finite-Element Sea-ice Ocean Model, a primitive-equation, hydrostatic ocean circulation model coupled with a dynamic-thermodynamic sea-ice model, which allows to quantify the amount of heat associated with cooling of the water column. Three important polynya regions are identified: at Brunt Ice Shelf, at Ronne Ice Shelf and along the southern part of the Antarctic Peninsula. Multiyear winter means (May-September 1990-2009) give an upward heat flux to the atmosphere of 311 W/m2 in the Brunt polynyas, 511 W/m2 in Ronne Polynya and 364 W/m2 in the Antarctic Peninsula polynyas, whereof 57 W/m2, 49 W/m2 and 48 W/m2, respectively, are supplied as oceanic heat flux from deeper layers. The mean winter sea ice production is 7.2 cm/d in the Brunt polynyas corresponding to an ice volume of 1.3 1010 m3/winter, 13.2 cm/d at Ronne polynya (4.4 1010 m3/winter), and 9.2 cm/d in the Antarctic Peninsula polynyas (2.1 1010 m3/winter). The heat flux to the atmosphere inside polynyas is 7 to 9 times higher than the heat flux in the adjacent area; polynya ice production per unit area exceeds adjacent values by a factor of 9 to 14.

Haid, V.; Timmermann, R.

2013-05-01

313

Joule-Heated Molten Regolith Electrolysis Reactor Concepts for Oxygen and Metals Production on the Moon and Mars.  

National Technical Information Service (NTIS)

The maturation of Molten Regolith Electrolysis (MRE) as a viable technology for oxygen and metals production on explored planets relies on the realization of the self-heating mode for the reactor. Joule heat generated during regolith electrolysis creates ...

J. A. Dominques L. Sibille

2012-01-01

314

Gold nanorod-facilitated localized heating of droplets in microfluidic chips.  

PubMed

A gold nanorod-facilitated optical heating method for droplets in microfluidic chips is reported. Individual and stream nanoliter level droplets containing gold nanorods are heated by a low power 808-nm-wavelength laser. Owing to the high photothermal conversion efficiency of gold nanorods, a droplet temperature of 95 C is achieved by employing a 13.6 mW laser with good reproducibility. The heating and cooling times are 200 and 800 ms, respectively, which are attributed to the fast thermal-transfer rates of the droplets. By controlling the irradiation laser power, the temperature cycles for polymerase chain reaction are also demonstrated. PMID:23389021

Li, Zhiyong; Wang, Pan; Tong, Limin; Zhang, Lei

2013-01-14

315

Theoretical Design of a Thermosyphon for Efficient Process Heat Removal from Next Generation Nuclear Plant (NGNP) for Production of Hydrogen  

SciTech Connect

The work reported here is the preliminary analysis of two-phase Thermosyphon heat transfer performance with various alkali metals. Thermosyphon is a device for transporting heat from one point to another with quite extraordinary properties. Heat transport occurs via evaporation and condensation, and the heat transport fluid is re-circulated by gravitational force. With this mode of heat transfer, the thermosyphon has the capability to transport heat at high rates over appreciable distances, virtually isothermally and without any requirement for external pumping devices. For process heat, intermediate heat exchangers (IHX) are required to transfer heat from the NGNP to the hydrogen plant in the most efficient way possible. The production of power at higher efficiency using Brayton Cycle, and hydrogen production requires both heat at higher temperatures (up to 1000oC) and high effectiveness compact heat exchangers to transfer heat to either the power or process cycle. The purpose for selecting a compact heat exchanger is to maximize the heat transfer surface area per volume of heat exchanger; this has the benefit of reducing heat exchanger size and heat losses. The IHX design requirements are governed by the allowable temperature drop between the outlet of the NGNP (900oC, based on the current capabilities of NGNP), and the temperatures in the hydrogen production plant. Spiral Heat Exchangers (SHEs) have superior heat transfer characteristics, and are less susceptible to fouling. Further, heat losses to surroundings are minimized because of its compact configuration. SHEs have never been examined for phase-change heat transfer applications. The research presented provides useful information for thermosyphon design and Spiral Heat Exchanger.

Piyush Sabharwall; Fred Gunnerson; Akira Tokuhiro; Vivek Utgiker; Kevan Weaver; Steven Sherman

2007-10-01

316

Materials experience and selection for nuclear materials production reactor heat exchangers  

SciTech Connect

The primary coolant systems for the heavy-water nuclear materials production reactors at the Savannah River Site are coupled to the secondary coolant systems through shell and tube heat exchangers. The head, shell, and tube sheets of these heat exchangers are fabricated from AISI Type 304 grades of austenitic stainless steel. The 8,957 tubes in each heat exchanger were originally fabricated from Type 304 stainless steel, but service experience has lead to the use of Sea Cure tubing in newer systems. The design includes double tube sheets, core rods, and 33,410 square feet of heat transfer surface. Tubes are rolled into the tube sheets and seal welded after rolling. The tubes contain Type 304 stainless steel rods which are positioned in the center of each tube axis to increase the fraction of the cooling water contacting the heat transfer surface. Each reactor utilizes twelve heat exchangers; thus the 120+ reactor-years of operating experience provide approximately 1,440 heat exchanger-years of service. Fatigue, stress corrosion cracking, crevice corrosion, and pitting have been observed during the service life. This paper describes the observed degradation processes and uses the operational experience to recommend materials for the Heavy Water -- New Production Reactor (HW-NPR).

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

1990-01-01

317

An evaluation of alternate production methods for Pu-238 general purpose heat source pellets  

SciTech Connect

For the past half century, the National Aeronautics and Space Administration (NASA) has used Radioisotope Thermoelectric Generators (RTG) to power deep space satellites. Fabricating heat sources for RTGs, specifically General Purpose Heat Sources (GPHSs), has remained essentially unchanged since their development in the 1970s. Meanwhile, 30 years of technological advancements have been made in the applicable fields of chemistry, manufacturing and control systems. This paper evaluates alternative processes that could be used to produce Pu 238 fueled heat sources. Specifically, this paper discusses the production of the plutonium-oxide granules, which are the input stream to the ceramic pressing and sintering processes. Alternate chemical processes are compared to current methods to determine if alternative fabrication processes could reduce the hazards, especially the production of respirable fines, while producing an equivalent GPHS product.

Mark Borland; Steve Frank

2009-06-01

318

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

Microsoft Academic Search

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

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

2009-01-01

319

Natural convection in a vertical rectangular enclosure with localized heating and cooling zones  

NASA Astrophysics Data System (ADS)

Experimental and numerical studies of natural convection in a single phase, closed thermosyphon were carried out using a vertical, rectangular enclosure model. Only one vertical plate plays the role of heat transfer surface having 100mm height and 100mm width, and others act as the adiabatic wall made of transparent plexi-glass. The heat transfer surface is separated into three horizontal zones with an equal height; top 1/3 and bottom 1/3 of the surface are cooling and heating zones, respectively and intermediate section is an adiabatic zone. Water is used as the working fluid. Variable parameters are distance D between the heat transfer surface and an adiabatic plate opposite to the heat transfer plate, and temperature difference ?T between heating and cooling zones. By changing both D and ?T, three regimes of the natural convection flow; quasi-two-dimensional steady, three-dimensional steady and unsteady flows are observed by means of thermo-sensitive liquid crystal powder and numerically simulated very well by solving a set of governing equations.

Ishihara, I.; Matsumoto, R.; Senoo, A.

320

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

321

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

PubMed Central

In synchronized continuous cultures of Saccharomyces cerevisiae CBS 8066, the production of the extracellular invertase (EC 3.2.1.26) showed a cyclic behavior that coincided with the budding cycle. The invertase activity increased during bud development and ceased at bud maturation and cell scission. The cyclic changes in invertase production resulted in cyclic changes in amounts of invertase localized in the cell wall. However, the amount of enzyme invertase present in the culture liquid remained constant throughout the budding cycle. Also, in asynchronous continuous cultures of S. cerevisiae, the production and localization of invertase showed significant fluctuation. The overall invertase production in an asynchronous culture was two to three times higher than in synchronous cultures. This could be due to more-severe invertase-repressive conditions in a synchronous chemostat culture. Both the intracellular glucose-6-phosphate concentration and residual glucose concentration were significantly higher in synchronous chemostat cultures than in asynchronous chemostat cultures. In the asynchronous and synchronous continuous cultures of S. cerevisiae, about 40% of the invertase was released into the culture liquid; it has generally been believed that S. cerevisiae releases only about 5% of its invertase. In contrast to invertase production and localization in the chemostat cultures of S. cerevisiae, no significant changes in inulinase (EC 3.2.1.7) production and localization were observed in chemostat cultures of Kluyveromyces maxianus CBS 6556. In cultures of K. marxianus about 50% of the inulinase was present in the culture liquid.

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

1991-01-01

322

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

PubMed

In synchronized continuous cultures of Saccharomyces cerevisiae CBS 8066, the production of the extracellular invertase (EC 3.2.1.26) showed a cyclic behavior that coincided with the budding cycle. The invertase activity increased during bud development and ceased at bud maturation and cell scission. The cyclic changes in invertase production resulted in cyclic changes in amounts of invertase localized in the cell wall. However, the amount of enzyme invertase present in the culture liquid remained constant throughout the budding cycle. Also, in asynchronous continuous cultures of S. cerevisiae, the production and localization of invertase showed significant fluctuation. The overall invertase production in an asynchronous culture was two to three times higher than in synchronous cultures. This could be due to more-severe invertase-repressive conditions in a synchronous chemostat culture. Both the intracellular glucose-6-phosphate concentration and residual glucose concentration were significantly higher in synchronous chemostat cultures than in asynchronous chemostat cultures. In the asynchronous and synchronous continuous cultures of S. cerevisiae, about 40% of the invertase was released into the culture liquid; it has generally been believed that S. cerevisiae releases only about 5% of its invertase. In contrast to invertase production and localization in the chemostat cultures of S. cerevisiae, no significant changes in inulinase (EC 3.2.1.7) production and localization were observed in chemostat cultures of Kluyveromyces maxianus CBS 6556. In cultures of K. marxianus about 50% of the inulinase was present in the culture liquid. PMID:2014991

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

1991-02-01

323

Spatial resolution of a chemiluminescence sensor for local heat-release rate and equivalence ratio measurements in a model gas turbine combustor  

NASA Astrophysics Data System (ADS)

The spatial resolution of a Chemiluminescence Sensor, based on focused Cassegrain optics, to detect the location of the reaction zone and heat-release rate in a model gas turbine combustor is reported. The sensor measures simultaneously the chemiluminescent intensities from OH* and CH* excited radicals in flames in order to obtain information on the local flame characteristics. The spatial resolution was evaluated by a combined theoretical and experimental study in laminar and turbulent flames and was supported by detailed chemistry calculations, including the chemiluminescent species, of unstrained one-dimensional flames. The experimental study involved simultaneous measurements of chemiluminescence with the sensor and laser-based reaction rate imaging, using the product of OH and CH2O radicals obtained from planar laser-induced fluorescence (PLIF), and OH PLIF for the location of the reaction zone. The study quantified the influence of flame shape and dimensions and the direction of traverse of the focal region of the sensor through the flames on the spatial resolution, thereby identifying the limitations and optimising the applicability of the sensor. The sensor was used to obtain local time-dependent measurements of heat-release and equivalence ratio of a reacting mixture, based on the chemiluminescent intensity ratio of OH*/CH*, in a swirl-stabilised model gas turbine combustor and quantified the degree of air-fuel premixedness, probability of reaction and power spectra of pressure and chemiluminescent intensity fluctuations in two unsteady flames.

Hardalupas, Y.; Panoutsos, C. S.; Taylor, A. M. K. P.

2010-10-01

324

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

2012-02-01

325

Localization and production of novel l-asparaginase from Pectobacterium carotovorum MTCC 1428  

Microsoft Academic Search

Bacterial l-asparaginase has been widely used as therapeutic agent in the treatment of various lymphoblastic leukemia diseases. Studies on localization and production of novel glutaminase-free l-asparaginase were performed using Pectobacterium carotovorum MTCC 1428. The localization of l-asparaginase was carried out using cell fractionation techniques. The activity of l-asparaginase was found to be 85 and 77% in the cytoplasm of P.

Sanjay Kumar; Veeranki Venkata Dasu; Kannan Pakshirajan

2010-01-01

326

Brand competition in CPG industries: Sustaining large local advantages with little product differentiation  

Microsoft Academic Search

In direct competition between national brands of consumer packaged goods (CPG), one brand often has a large local share advantage\\u000a over the other despite the similarity of the branded products. I present an explanation for these large and persistent advantages\\u000a in the context of local competition on perceived quality or brand image. The main result of the analysis is a

Bart J. Bronnenberg

2008-01-01

327

Identification of Fibroblasts Responsible for Increased Collagen Production in Localized Scleroderma by In Situ Hybridization  

Microsoft Academic Search

Skin biopsies from seven patients with localized scleroderma (morphea) and from two healthy individuals were studied by in situ hybridization to localize the cells responsible for increased procollagen production. In scleroderma lesions, high levels of pro?1(I) and pro?1 (III) collagen mRNAs were detected in some but not all fibroblasts, suggesting the presence of a subpopulation responsible for the increased collagen

Veli-Matti Khri; Minna Sandberg; Hannu Kalimo; Tuula Vuorio; Eero Vuorio

1988-01-01

328

Effect of variable heat production on the thermal evolution of the mantle  

NASA Astrophysics Data System (ADS)

The Earth currently loses heat at about 44 TW; this reflects both cooling and radioactive decay. From cosmochemical models, the bulk silicate earth budgets of uranium, thorium, and potassium are thought to produce about 20 TW. Thermal history models, which balance the rate of heat loss against the resulting temperatures in the mantle, yield a slightly higher value of about 30 TW. This heat production is distributed among the continental and oceanic crust, mantle, and core. The total heat production in the depleted mantle (the MORB source), plus the crust, may total between 9.6 and 17 TW, leaving a substantial amount of heat unaccounted for (at least 3 to 10.4 TW, assuming that the cosmochemical models correctly estimate the bulk silicate earth.) The most likely reservoir for the excess is either in the deep mantle or in the core. We investigate the several models for the distribution of the excess heat within the mantle, using numerical models of convection. Our goal is to assess the effects on Earth's thermal history of a mantle reservoir of excess heat production. Such a reservoir could be formed, for example, by incomplete differentiation of the crust and mantle, or by separation and isolation of recycled oceanic crust. We concentrated on models with a moderate amount of excess heat production in a lower layer, while remaining within the constraints required above. The excess heat must be low enough to prevent an excessive temperature increase across any internal boundary layers. In models with two strictly isolated layers and equivalent total heat production, the temperature-dependent viscosity adjusts to maintain an equivalent temperature drop across the layers, regardless of the thickness of the layers. The regulation of viscosity by temperature is consistent with the results of earlier parameterized models of two-layered convection by a number of researchers. Using a double-diffusive model of two-component convection to relax the mass transfer constraint across the interface, we observe substantial topography on the boundary. We will discuss the effect of fully dynamical layering on the thermal evolution.

Kellogg, L. H.; Ferrachat, S.; Natarajan, C. S.

2003-12-01

329

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

330

The distribution of radiogenic heat production as a function of depth in the Sierra Nevada Batholith, California  

Microsoft Academic Search

Geochemical analyses and geobarometric determinations have been combined to create a depth vs. radiogenic heat production database for the Sierra Nevada batholith, California. This database shows that mean heat production values first increase, then decrease, with increasing depth. Heat production is ?2 ?W\\/m3 within the ?3-km-thick volcanic pile at the top of the batholith, below which it increases to an

Robert J. Brady; Mihai N. Ducea; Steven B. Kidder; Jason B. Saleeby

2006-01-01

331

Full surface local heat transfer coefficient measurements in a model of an integrally cast impingement cooling geometry  

SciTech Connect

Cast impingement cooling geometries offer the gas turbine designer higher structural integrity and improved convective cooling when compared to traditional impingement cooling systems, which rely on plate inserts. In this paper, it is shown that the surface that forms the jets contributes significantly to the total cooling. Local heat transfer coefficient distributions have been measured in a model of an engine wall cooling geometry using the transient heat transfer technique. The method employs temperature-sensitive liquid crystals to measure the surface temperature of large-scale perspex models during transient experiments. Full distributions of local Nusselt number on both surfaces of the impingement plate, and on the impingement target plate, are presented at engine representative Reynolds numbers. The relative effects of the impingement plate thermal boundary condition and the coolant supply temperature on the target plate heat transfer have been determined by maintaining an isothermal boundary condition at the impingement plate during the transient tests. The results are discussed in terms of the interpreted flow field.

Gillespie, D.R.H.; Wang, Z.; Ireland, P.T. [Univ. of Oxford (United Kingdom). Dept. of Engineering Science; Kohler, S.T. [Rolls Royce, Bristol (United Kingdom)

1998-01-01

332

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

PubMed

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

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

2013-05-01

333

Modelling the measured local time evolution of strongly nonlinear heat pulses in the Large Helical Device  

NASA Astrophysics Data System (ADS)

In some magnetically confined plasmas, an applied pulse of rapid edge cooling can trigger either a positive or negative excursion in the core electron temperature from its steady state value. We present a new model which captures the time evolution of the transient, non-diffusive local dynamics in the core plasma. We show quantitative agreement between this model and recent spatially localized measurements (Inagaki et al 2010 Plasma Phys. Control. Fusion 52 075002) of the local time-evolving temperature pulse in cold pulse propagation experiments in the Large Helical Device.

Dendy, R. O.; Chapman, S. C.; Inagaki, S.

2013-11-01

334

Nuclear data production, calculation and measurement: a global overview of the gamma heating issue  

NASA Astrophysics Data System (ADS)

The gamma heating evaluation in different materials found in current and future generations of nuclear reactor (EPRTM, GENIV, MTR-JHR), is becoming an important issue especially for the design of many devices (control rod, heavy reflector, in-core & out-core experiments). This paper deals with the works started since 2009 in the Reactor Studies Department of CEA Cadarache in ordre to answer to several problematic which have been identified as well for nuclear data production and calculation as for experimental measurement methods. The selected subjects are: Development of a Monte Carlo code (FIFRELIN) to simulate the prompt fission gamma emission which represents the major part of the gamma heating production inside the core Production and qualification of new evaluations of nuclear data especially for radiative capture and inelastic neutron scattering which are the main sources of gamma heating out-core Development and qualification of a recommended method for the total gamma heating calculation using the Monte Carlo simulation code TRIPOLI-4 Development, test and qualification of new devices dedicated to the in-core gamma heating measurement as well in MTR-JHR as in zero power facilities (EOLE-MINERVE) of CEA, Cadarache to increase the experimental measurement accuracy.

Colombier, A.-C.; Amharrak, H.; Fourmentel, D.; Ravaux, S.; Rgnier, D.; Gueton, O.; Hudelot, J.-P.; Lemaire, M.

2013-03-01

335

Stimulation of cysteinyl leukotriene production in mast cells by heat shock and acetylsalicylic acid.  

PubMed

Immunoglobulin (Ig) E-dependent activation of mast cells is central to the allergic response. The engagement of IgE-occupied receptors initiates a series of molecular events that causes the release of preformed, and de novo synthesis of, allergic mediators. Cysteinyl leukotrienes are able to contract airway smooth muscle and increase mucus secretion and vascular permeability and recruit eosinophils. Mast cells have also recently been recognized as active participants in innate immune responses. Heat stress can modulate innate immunity by inducing stress proteins such as heat-shock proteins (HSPs). We previously demonstrated that treatment of mast cells with heat shock or acetylsalicylic acid results in an increase of TNF-alpha and IL-6 release. This effect was paralleled by expression of HSP70. In the current study, we further investigated the effects of heat shock and acetylsalicylic acid on the activation of mast cells and the release of cysteinyl leukotrienes. In mouse mast cells, derived from a culture of bone marrow cells, responsiveness to heat shock, acetylsalicylic acid and exogenous or endogenous HSP70 was monitored by measuring leukotriene C4 release. We show that after heat shock treatment and exposure to acetylsalicylic acid leukotriene production was increased. Moreover, exogenous rHSP70 also induced leukotriene production. Because it has been reported that leukotriene production in mast cells may be mediated by Toll like receptor (TLR) activation, and HSP70 also activates TLRs signaling, we further explored these issues by using mast cells that are not able to produce HSP70, i.e. heat shock factor-1 (HSF-1) knockout cells. We found that in HSF-1 knockout bone marrow derived mast cells, heat shock and acetylsalicylic acid failed to induce release of leukotrienes. Moreover, in wild type cells the surface expression of TLR4 was attenuated, whereas the intracellular expression was up-regulated. We conclude that heat shock and acetylsalicylic acid induce the production and release of heat shock proteins from mast cells, which in turn stimulate leukotriene synthesis through activation of TLR4. PMID:17306251

Mortaz, Esmaeil; Redegeld, Frank A; Dunsmore, Kathy; Odoms, Kelli; Wong, Hector R; Nijkamp, Frans P; Engels, Ferdi

2007-01-20

336

Factors affecting aerobic recovery heat production and recovery ratio of frog sartorius.  

PubMed Central

1. Sartorius muscles of Rana temporaria, equilibrated at 20 degrees C in Ringer solution buffered with phosphates, were stimulated isometrically for 0.2 up to 0.75 s at lengths varying from 1.03 to 1.48 times rest length, L0. The aerobic recovery heat was measured for 10.5 min after contraction. 2. The recovery heat production had a complex time course, showing a variable delay to maximum, declining thereafter. In most cases, the rate of heat production did not decrease monotonically; attention was focused on the slow exponential decay which only persisted from 1.5-5 min after contraction. This latter part of the time course was considered as strictly aerobic and characterized by the time constant tau s. 3. Increasing the tetanus duration from 0.2 to 0.75 s increased initial heat Qi and recovery heat Qr in proportion, so that the recovery ratio R (Qr/Qi) did not change; it was equal to 1.29 +/- 0.03 (S.E.M.; n = 44) for muscles at about L0. The kinetics of heat production were modified with longer tetani; in particular, tau s was increased from 2.2 to 5.2 min. 4. When muscles were stretched beyond L0, as long as there was no increase of the resting heat rate (stretch response or 'Feng effect'), recovery heat production had a similar evolution to that in muscles at about L0; R was constant and equal to 1.21 +/- 0.03 (n = 46). 5. When muscles were sufficiently stretched to develop a stretch response, R increased proportionally to the stretch response. The effect seemed independent of the contractile machinery, as it vanished concomitantly with the stretch response, while force and Qi remained unchanged for the length considered. The kinetics were also modified--the delay to maximum was no longer detected and tau s most likely increased. 6. Substitution of 60% of the NaCl of the Ringer solution by NaI (mol/mol) produced a significant increase of R, mainly due to the increase of Qr. 7. The results show that neither the time course nor the amount of aerobic recovery heat Qr are strictly determined by the amount of initial heat Qi. The hypothesis is discussed that Qr might include a variable fraction due to processes which are not directly implicated in the actin-myosin interactions, possibly those involving the cytosolic Ca2+ concentration and the rate of resting metabolism. Images Fig. 3

Godfraind-De Becker, A

1989-01-01

337

Local Heat Transfer and CHF for Subcoled Flow Boiling. 1994 Annual Report.  

National Technical Information Service (NTIS)

The physical phenomenon of forced convective boiling is probably one of the most interesting and complex transport phenomena. It has been under study for more than two centuries. Simply stated, forced convective subcooled boiling involves a locally boilin...

R. D. Boyd

1994-01-01

338

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

SciTech Connect

The Vermont Biofuels initiative (VBI) is the Vermont Sustainable Jobs Fundâ??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 Vermontâ??s dependency on petroleum through the development of homegrown alternatives. As such, it supports the four key priorities of the U.S. Department of Energyâ??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 organizationâ?? the Biofuels Center of North Carolinaâ??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 Farmâ??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 LLCâ??s proposed multi-feedstock biodigester; 6) technology and infrastructure purchases for the construction of a â??Cow Powerâ? 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 Vermontâ??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

339

Influence of the dwarfing gene dw on egg production and viability under summer heat stress  

Microsoft Academic Search

1. Dwarf egg layer (Narmada XL) dwarf broiler (DB) and normal bodied sib (NB) hens were studied under cyclic summer hot and dry heat stress of 21.1 to 45.5 C for a period of 50 d. The genotype effect for egg production was significant (P<0.01).2. N?XL and DB genotypes laid 12.1% more eggs than NB. Egg production declined by 3.17,

A. G. Khan; R. N. S. Tiwari; K. K. S. Baghel; R. D. Gupta

1987-01-01

340

Relative Contributions of Uranium, Thorium, and Potassium to Heat Production in the Earth.  

PubMed

Data from a wide variety of igneous rock types show that the ratio of potassium to uranium is approximately 1 X 10(4). This suggests that the value of K/U approximately 1 X 10(4) is characteristic of terrestrial materials and is distinct from the value of 8 X 10(4) found in chondrites. In a model earth with K/U approximately 10(4), uranium and thorium are the dominant sources of radioactive heat at the present time. This will permit the average terrestrial concentrations of uranium and thorium to be 2 to 4.7 times higher than that observed in chondrites. The resulting models of the terrestrial heat production will be considerably different from those for chondritic heat production because of the longer half-life of U(238) and Th(238) compared with K(40). PMID:17833743

Wasserburg, G J; Macdonald, G J; Hoyle, F; Fowler, W A

1964-01-31

341

Electrostatic coherent structures generation by local heating in a collisionless plasma  

Microsoft Academic Search

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

C. Briand; A. Mangeney; F. Califano

2007-01-01

342

Prediction of local thermal contact conductance in plate finned-tube heat exchangers  

Microsoft Academic Search

An inverse problem utilizing the conjugate gradient method (CGM) of minimization with adjoint equation is used successfully to estimate the temporally and circumferentially varying thermal contact conductance of a plate finned-tube heat exchanger by reading the transient temperature measurement data from the thermocouples located on the plate and around the tube.It is assumed that no prior information is available on

Cheng-Hung Huang; Duen-Min Wang; Hsi-Mei Chen

1999-01-01

343

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

344

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

345

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

Microsoft Academic Search

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

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

1989-01-01

346

Radionuclide concentration in fuels and ash products from biofuel heating plants.  

National Technical Information Service (NTIS)

The activity concentration of the radionuclides K-40, Ac-228, Pa-234, Mn-54, Co-60, Zr-95, Ru-106, Ag-110m, Sb-125, Cs-134, Cs-137, and Ce-144 have been investigated in peat wood chips and ash products from 13 Swedish district heating plants during the wi...

B. Erlandsson R. Hedvall S. Mattsson

1995-01-01

347

Modelling temperature-dependent heat production over decades in High Arctic coal waste rock piles  

Microsoft Academic Search

Subsurface heat production from oxidation of pyrite is an important process that may increase subsurface temperatures within coal waste rock piles and increase the release of acid mine drainage, AMD. Waste rock piles in the Arctic are especially vulnerable to changes in subsurface temperatures as the release of AMD normally is limited by permafrost. Here we show that temperatures within

J. Hollesen; B. Elberling; P. E. Jansson

2011-01-01

348

Heat and moisture production of growing-finishing gilts as affected by environmental temperature  

Technology Transfer Automated Retrieval System (TEKTRAN)

Heat and moisture production (HMP) values are used to size ventilation fans in animal housing. The HMP values that are currently published in the ASABE (American Society of Agricultural and Biological Engineers) standards were from data collected in the early 1950. This study is one of a series of...

349

Optimization system for combined heat and electricity production in the wood-processing industry  

Microsoft Academic Search

In the Croatian economy, the wood-processing industry is among the country's strategic export branches. The energy costs have a partial impact on the final price of wood products. The goal of this work paper is to minimize energy costs in this sector, using a mathematical formula that computes the lowest heat capacity as the cogeneration system starts to be more

V. Uran

2006-01-01

350

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

351

Helminth control using local resources in smallholder production systems of Asia.  

PubMed

Practical helminth control in smallholder systems needs to match technical options with local knowledge, locally available animal and feed resources and the needs of both producers and consumers. Despite extensive research over many decades the uptake of new technology in these systems has been slow and limited to few farmers with access to good technical support. Investment by small holders is constrained by lack of regular market signals for livestock and livestock products. Examples of effective helminth control in cattle, buffalo, sheep, goat and pig systems show that effective control is possible using local resources and knowledge. Livestock systems in Asia are changing rapidly through industrialisation of production and consolidation of supply chains and retail markets, but smallholder systems, which are resilient and multipurpose, will remain important in rural areas and in peri-urban environments. They also provide a significant pathway for the poor to build assets and generate income. Helminth control in these systems will always vary greatly between farmers and systems and will need to be relatively simple and tailored to locally available resources. The public sector will continue to provide advice on appropriate genetics, to regulate drug importation, use and quality, and ensure novel helminth control options are investigated for local application and promotion to livestock producers. The private sector has the complementary role to develop clear market signals for livestock and livestock products, and make anthelmintics available in appropriate packages. Improved helminth control has the potential to increase the profitability and sustainability of all components of the livestock sector. PMID:18414372

Gray, G D; Knox, M R; Cargill, C

2008-02-01

352

An assessment of solar hot water heating in the Washington, D.C. area - Implications for local utilities  

NASA Astrophysics Data System (ADS)

A survey of residential solar hot water heating in the Washington, D.C. area is presented with estimates of the total solar energy contribution per year. These estimates are examined in relation to a local utility's peak-load curves to determine the impact of a substantial increase in solar domestic hot water use over the next 20 yr in the area of utility management. The results indicate that a 10% market penetration of solar water heaters would have no detrimental effect on the utility's peak-load profile and could save several million dollars in new plant construction costs.

Stuart, M. W.

1980-04-01

353

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

NASA Astrophysics Data System (ADS)

The naphthalene sublimation technique is used to investigate the heat transfer characteristics of turbulent air flow in a two-pass channel. A test section that resembles the internal cooling passages of gas turbine airfoils is employed. The local Sherwood numbers on the ribbed walls were found to be 1.5-6.5 times those for a fully developed flow in a smooth square duct. Depending on the rib angle-of-attack and the Reynolds number, the average ribbed-wall Sherwood numbers were 2.5-3.5 times higher than the fully developed values.

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

1987-05-01

354

Survey report on rf radiation exposures from heat sealers at Beaverite Products, Inc. , Beaver Falls, New York. Industrywide study  

Microsoft Academic Search

The effect of radiofrequency (RF) radiation exposures from heat sealers was investigated in workers in a polyvinyl chloride and vinyl acetate production facility (SIC-2821). The RF radiation exposure of 16 operators at 8 heat sealers were measured. Six of eight heat sealers generated incident radiation fields in excess of the current 10 milliwatts per square centimeter OSHA standard. Thirteen of

C. Cox; D. L. Conover; W. E. Jr Murray; B. E. Baum

1980-01-01

355

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

NASA Astrophysics Data System (ADS)

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

Mbius, Arnulf; Schn, J. Christian

2012-02-01

356

Determination of the position of a localized heat source within a chirped fibre Bragg grating using a Fourier transform technique  

NASA Astrophysics Data System (ADS)

The ability to determine the centre position of a localized temperature change within a chirped fibre Bragg grating (CFBG) has been investigated as a function of grating strength. The intragrating sensor is based on the analysis of reflected power spectra arising from a CFBG. The technique uses a discrete Fourier transform (FFT) in which the measured spectrum of the CFBG due to a localized temperature change (heat source) was simulated using a FFT grating design model. The model operated on the reference spectrum and hypothesis temperature distributions, T(z), to generate a spectrum of a CFBG subjected to a hypothesis temperature disturbance. The simulated spectrum was fitted to the measured spectrum using a three-parameter automatic disturbance function fitting algorithm operating on position, width and amplitude of temperature change. RMS deviations to within 0.03 mm of applied values of position have been obtained.

Nand, Anbhawa; Kitcher, Daniel J.; Wade, Scott A.; Nguyen, Thinh B.; Baxter, Greg W.; Jones, Rhys; Collins, Stephen F.

2006-06-01

357

Doing Cultural Work: Local Postcard Production and Place Identity in a Rural Shire  

ERIC Educational Resources Information Center

|Studies of place construction in the rural studies literature have largely privileged the role of professionals over that of local lay actors. This paper contributes to redressing this imbalance through a critical case-study of lay postcard production in a rural shire. Drawing on original, qualitative research conducted in the Shire of

Mayes, Robyn

2010-01-01

358

Microanalysis of the reaction product in Karnovsky and Roots histochemical localization of acetylcholinesterase  

SciTech Connect

X-ray energy dispersive microanalysis of the reaction product in Karnovsky and Roots histochemical localization of acetylcholinesterase indicated the presence of sulfur, iodine, copper, and iron. The reaction was run in vitro using purified acetylcholinesterase from the electric eel to confirm our previous results on similarly treated neuromuscular junction in situ.

Tewari, J.P.; Sehgal, S.S.; Malhotra, S.K.

1982-05-01

359

Nitric Oxide Production in Rat Thalamus Changes with Behavioral State, Local Depolarization, and Brainstem Stimulation  

Microsoft Academic Search

Since its discovery as a putative neurotransmitter in the CNS, several functional roles have been suggested for nitric oxide (NO). However, few studies have investigated the role of NO in natural physiology. Because NO synthase (NOS) has been localized in regions believed to be important for attention and arousal, we hypothesized that NO production would be state- dependent. To test

Julie A. Williams; Steven R. Vincent; Peter B. Reiner

1997-01-01

360

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

Microsoft Academic Search

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

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

1982-01-01

361

The impact of inward FDI on local companies' labour productivity: evidence from the Italian case  

Microsoft Academic Search

The article aims to investigate the impact of inward foreign direct investment (FDI) occurring through acquisition upon the local target company' performance, as measured by labour productivity. It relies upon the idea that multinational enterprises (MNEs) act as a device to transfer firm-specific proprietary assets, thus causing their subsidiaries to exhibit better performance than their host country rivals. Specifically, our

Lucia Piscitello; Larissa Rabbiosi

2005-01-01

362

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

NASA Astrophysics Data System (ADS)

This paper reports on the analysis of results from a large urban heat island experiment (UHI) performed in Phoenix (AZ) in April 2008. From 1960 to 2000, the city of Phoenix experienced a minimum temperature rise of 0.47 C per decade, which is one of the highest rates in the world for a city of this size (Golden, 2004). Contemporaneously, the city has recorded a rapid enlargement and large portion of the land and desert vegetation have been replaced by buildings, asphalt and concrete (Brazel et al., 2007, Emmanuel and Fernando, 2007). Besides, model predictions show that minimum air temperatures for Phoenix metropolitan area in future years might be even higher than 38 C. In order to make general statements and mitigation strategies of the UHI phenomenon in Phoenix and other cities in hot arid climates, a one-day intensive experiment was conducted on the 4th-5th April 2008 to collect surface and ambient temperatures within various landscapes in Central Phoenix. Inter alia, infrared thermography (IRT) was used for UHI mapping. The aim was to investigate UHI modifications within the city of Phoenix at three spatial scales i.e. the local (Central Business District, CBD), the neighborhood and the city scales. This was achieved by combining IRT measurements taken at ground level by mobile equipment (automobile-mounted and pedicab) and at high elevation by a helicopter. At local scale detailed thermographic images of about twenty building faades and several street canyons were collected. In total, about two thousand images were taken during the 24-hour campaign. Image analysis provides detailed information on building surface and pavement temperatures at fine resolution (Hedquist et al. 2009, Di Sabatino et al. 2009). This unique dataset allows us several investigations on local air temperature dependence on albedo, building thermal inertia, building shape and orientation and sky view factors. Besides, the mosaic of building faade temperatures are being analyzed in terms of local buoyancy fluxes and possible wind flow modifications by such thermally driven flows will be elucidated. The results are of consequence for understanding microclimate of large cities in order to derive urbanizations schemes for numerical models and to set-up suitable heat mitigation strategies. REFERENCES Brazel, AJ, Gober, P., Lee, S., Grossman-Clarke, S., Zehnder, J., Hedquist, B. and Comparri, E 2007: Dynamics and determinants of urban heat island change (1990-2004) with Phoenix, Arizona, USA. Climate Research 33, 171-182. Di Sabatino S, Hedquist BC, Carter W, Leo LS, Fernando HJS. 2009. Phoenix urban heat island experiment: effects of built elements. Proceedings of the Eighth Symposium on the Urban Environment, Phoenix, Arizona. Emmanuel, R. and Fernando HJS 2007: Effects of urban form and thermal properties in urban heat island mitigation in hot humid and hot arid climates: The cases of Colombo, Sri Lanka and Phoenix, USA. Climate Research 34, 241-251. Golden JS. 2004. The built environment induced urban heat island in rapidly urbanizing arid regions: a sustainable urban engineering complexity. Environmental Sciences 1(4):321-349. Hedquist, BC, Brazel, AJ, Di Sabatino, S., Carter, W. and Fernando, HJS 2009: Phoenix urban heat island experiment: micrometeorological aspects. Proceedings of the Eighth Symposium on the Urban Environment, Phoenix, Arizona.

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

2009-04-01

363

Effect of Local Heating and Cooling on Cambial Activity and Cell Differentiation in the Stem of Norway Spruce (Picea abies)  

PubMed Central

Background and Aims The effect of heating and cooling on cambial activity and cell differentiation in part of the stem of Norway spruce (Picea abies) was investigated. Methods A heating experiment (2325?C) was carried out in spring, before normal reactivation of the cambium, and cooling (911?C) at the height of cambial activity in summer. The cambium, xylem and phloem were investigated by means of light- and transmission electron microscopy and UV-microspectrophotometry in tissues sampled from living trees. Key Results Localized heating for 10 d initiated cambial divisions on the phloem side and after 20 d also on the xylem side. In a control tree, regular cambial activity started after 30 d. In the heat-treated sample, up to 15 earlywood cells undergoing differentiation were found to be present. The response of the cambium to stem cooling was less pronounced, and no anatomical differences were detected between the control and cool-treated samples after 10 or 20 d. After 30 d, latewood started to form in the sample exposed to cooling. In addition, almost no radially expanding tracheids were observed and the cambium consisted of only five layers of cells. Low temperatures reduced cambial activity, as indicated by the decreased proportion of latewood. On the phloem side, no alterations were observed among cool-treated and non-treated samples. Conclusions Heating and cooling can influence cambial activity and cell differentiation in Norway spruce. However, at the ultrastructural and topochemical levels, no changes were observed in the pattern of secondary cell-wall formation and lignification or in lignin structure, respectively.

GRICAR, JOZICA; ZUPANCIC, MARTIN; CUFAR, KATARINA; KOCH, GERALD; SCHMITT, UWE; OVEN, PRIMOZ

2006-01-01

364

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

Microsoft Academic Search

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

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

2007-01-01

365

Selective Functionalization of Silicon Micro\\/Nanowire Sensors via Localized Joule Heating  

Microsoft Academic Search

A novel approach to achieve localized surface functionalization of silicon-based micro and nanoscale linear structures (e.g., silicon nanowire sensors) is proposed in this paper. This method is based upon the protection of silicon surface by hydrophobic polymer layers such as polytetrafluoroethylene (PTFE). These layers are used as a protective, patterning barrier against surface functionalization of silicon or silicon oxide surface.

Inkyu Park; Zhiyong Li; A. P. Pisano

2007-01-01

366

Local heating and viscosity drop during shear band evolution in bulk metallic glasses under quasistatic loading  

Microsoft Academic Search

Based on the facts that the thickness of a shear band in bulk metallic glasses (BMGs) is a few tens of nanometers, the shear displacement across the band is few micrometers, and the time for their formation is in submicrosecond duration, the local strain rates within the shear band can be as high as 109\\/s. To capture such dynamic effects,

Hongwen Zhang; Ghatu Subhash; Spandan Maiti

2007-01-01

367

An efficient envelope-based Branch and Bound algorithm for non-convex combined heat and power production planning  

Microsoft Academic Search

Combined heat and power (CHP) production is universally accepted as one of the most energy-efficient technologies to produce energy with lower fuel consumption and fewer emissions. In CHP technology, heat and power generation follow a joint characteristic. Traditional CHP production is usually applied in backpressure plants, where the joint characteristic can often be represented by a convex model. Advanced CHP

Aiying Rong; Risto Lahdelma

2007-01-01

368

Analysis of Vertical Turbulent Heat Flux Limit in Stable Conditions with a Local Equilibrium, Turbulence Closure Model  

NASA Astrophysics Data System (ADS)

Assuming that the vertical turbulent heat flux vanishes at extremely stable conditions, one should expect its maximal absolute value to occur somewhere at moderate stability, between a neutral and extremely stable equilibrium. Consequently, in some situations duality of solutions may be encountered (e.g. two different values of temperature difference associated with the same values of heat flux and wind speed). A quantitative analysis of this feature with a local equilibrium Reynolds-stress model is presented. The fixed-wind / fixed-shear maximum has been identified both in the bulk and in single-point flux-gradient relationships (that is, in the vertical temperature gradient and wind-shear parameter domain). The value of the Richardson number corresponding to this maximum is derived from the model equations. To study the possible feedback in strongly stable conditions, weak and intense cooling scenarios have been simulated with a one-dimensional numerical, high-resolution atmospheric boundary-layer model. Despite the rapid cooling, flow decoupling at the surface has not been observed; instead, a stability-limited heat flux is maintained, with a gradual increase of the Richardson number towards the top of the turbulent layer, with some signs of oscillatory behaviour at intermediate heights. Vertical changes of wind shear and the Brunt-Visl frequency display a remarkably non-monotonic character, with some signs of a gradually developing instability.

?obocki, Lech

2013-09-01

369

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

NASA Astrophysics Data System (ADS)

Soil-mantled upland landscapes are widespread across the habitable world, support extensive life, and are the interface between the atmosphere, hydrosphere, and lithosphere but typically are not cultivated. Soil found across such landscapes fits the conceptual framework of a physically mobile layer derived from the underlying parent material along with some locally derived organic content. The extent and persistence of these upland soils depend on the long-term balance between soil production and erosion. Here we briefly review methods used to quantify the physical and chemical processes of soil production and erosion and revisit three granitic study areas in southeastern Australia and northern California that enabled early quantification of the soil production function and topographic controls on chemical weathering. We then present new major and trace element data from 2-m by 2-m pits dug at each field site to quantify local variability of Zr concentrations and the chemical index of alteration (CIA), weathering indices used to determine chemical weathering rates and extents in soils and saprolites. Using both new and previously published data, we compare differences between local variability and regional, as well as intersite variability of these important indices. For each of the 2-m pits, we collected 25 samples and found that the simple mean and the 2? standard deviation best describe the local variation in the data. We also find that the variability in the 2-m pit data lies within variability observed in the same data from samples collected in individual soil pits across each of the field sites and that the differences between sites are consistent with previously published results. These observations highlight the importance of quantifying local scale variability in studies that use similar, multifaceted measurements to quantify hillslope soil production and erosion processes.

Heimsath, Arjun M.; Burke, Benjamin C.

2013-10-01

370

Computation of turbulent flow in mixed convection in a cavity with a localized heat source  

SciTech Connect

A numerical simulation of the turbulent transport from an isolated heat source in a square cavity with side openings is presented in this work. The openings allow an externally induced air stream at ambient temperature to flow through the cavity and, thus, mixed convection arises. Results for the turbulent regime are obtained, by employing a suitable, high-Reynolds-number form of the K-E turbulence model. A stream junction-vorticity mathematical formulation is used, along with the kinetic energy and dissipation rate equations and an expression for the eddy viscosity. A time-marching scheme is employed, using the ADI method. The values of the Reynolds number Re, associated with the external flow, and the Grashof number Gr, based on the heat flux from the source, for which turbulent flow sets in are sought. Two typical values of the Reynolds number are chosen, Re = 1000 and Re = 2000, and turbulent results are obtained in the range Gr = 5 X 10{sup 7}-5 X 10{sup 8}. For both values of Re, the average Nusselt number over the surface of the source is found to vary with Gr in a fashion consistent with previous numerical and experimental results for closed cavities, while the effect of Re in the chosen range of values was small. 25 refs., 11 figs., 2 tabs.

Papanicolaou, E. [Univ. of Karlsruhe (Germany); Jaluria, Y. [Rutgers, the State Univ. of New Jersey, New Brunswick, NJ (United States)

1995-08-01

371

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

372

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

373

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

NASA Astrophysics Data System (ADS)

In this manuscript we investigate the use of the maximum entropy production (MEP) principle for modeling biogeochemical processes that are catalyzed by living systems. Because of novelties introduced by the MEP approach, many questions need to be answered and techniques developed in the application of MEP to describe biological systems that are responsible for energy and mass transformations on a planetary scale. In previous work we introduce the importance of integrating entropy production over time to distinguish abiotic from biotic processes under transient conditions. Here we investigate the ramifications of modeling biological systems involving one or more spatial dimensions. When modeling systems over space, entropy production can be maximized either locally at each point in space asynchronously or globally over the system domain synchronously. We use a simple two-box model inspired by two-layer ocean models to illustrate the differences in local versus global entropy maximization. Synthesis and oxidation of biological structure is modeled using two autocatalytic reactions that account for changes in community kinetics using a single parameter each. Our results show that entropy production can be increased if maximized over the system domain rather than locally, which has important implications regarding how biological systems organize and supports the hypothesis for multiple levels of selection and cooperation in biology for the dissipation of free energy.

Vallino, J. J.

2011-06-01

374

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

NASA Astrophysics Data System (ADS)

In this manuscript we investigate the use of the maximum entropy production (MEP) principle for modeling biogeochemical processes that are catalyzed by living systems. Because of novelties introduced by the MEP approach, many questions need to be answered and techniques developed in the application of MEP to describe biological systems that are responsible for energy and mass transformations on a planetary scale. In previous work we introduce the importance of integrating entropy production over time to distinguish abiotic from biotic processes under transient conditions. Here we investigate the ramifications of modeling biological systems involving one or more spatial dimensions. When modeling systems with spatial dimensions, entropy production can be maximized either locally at each point in space asynchronously or globally over the system domain synchronously. We use a simple two-box model inspired by two-layer ocean models to illustrate the differences in local versus global entropy maximization. Synthesis and oxidation of biological structure is modeled using two autocatalytic reactions that account for changes in community kinetics using a single parameter each. Our results show that entropy production can be increased if maximized over the system domain rather than locally, which has important implications regarding how biological systems organize and supports the hypothesis for multiple levels of selection and cooperation in biology for the dissipation of free energy.

Vallino, J. J.

2011-01-01

375

Acquisition of thermotolerance in soybean seedlings: synthesis and accumulation of heat shock proteins and their cellular localization  

SciTech Connect

When soybean Glycine max var Wayne seedlings are shifted from a normal growth temperature of 28/sup 0/C up to 40/sup 0/C (heat shock or HS), there is a dramatic change in protein synthesis. A new set of proteins known as shock proteins (HSPs) is produced and normal protein synthesis is greatly reduced. However, a pretreatmemt at 40/sup 0/C or a brief (10 minute) pulse treatment at 45/sup 0/C followed by a 28/sup 0/C incubation provide protection (thermal tolerance) to a subsequent exposure at 45/sup 0/C. During 40/sup 0/C HS, some HSPs become localized and stably associated with purified organelle fractions while others do not. A chase at 28/sup 0/C results in the gradual loss over a 4-hour period of the HSPs from the organelle fractions, but the HSPs remain selectively localized during a 40/sup 0/C chase period. The relative amount of HSPs which relocalize during a second HS increases with higher temperatures from 40/sup 0/C to 45/sup 0/C. Proteins induced by arsenite treatment are not selectively localized with organelle fractions at 28/sup 0/C but become organelle-associated during a subsequent HS at 40/sup 0/C.

Lin, C.Y.; Roberts, J.K.; Key, J.L.

1984-01-01

376

Hyperthyroidism increases the uncoupled ATPase activity and heat production by the sarcoplasmic reticulum Ca2+-ATPase.  

PubMed Central

The sarcoplasmic reticulum Ca2+-ATPase is able to modulate the distribution of energy released during ATP hydrolysis, so that a portion of energy is used for Ca2+ transport (coupled ATPase activity) and a portion is converted into heat (uncoupled ATPase activity). In this report it is shown that T4 administration to rabbits promotes an increase in the rates of both the uncoupled ATPase activity and heat production in sarcoplasmic reticulum vesicles, and that the degree of activation varies depending on the muscle type used. In white muscles hyperthyroidism promotes a 0.8-fold increase of the uncoupled ATPase activity and in red muscle a 4-fold increase. The yield of vesicles from hyperthyroid muscles is 3-4-fold larger than that obtained from normal muscles; thus the rate of heat production by the Ca2+-ATPase expressed in terms of g of muscle in hyperthyroidism is increased by a factor of 3.6 in white muscles and 12.0 in red muscles. The data presented suggest that the Ca2+-ATPase uncoupled activity may represent one of the heat sources that contributes to the enhanced thermogenesis noted in hyperthyroidism.

Arruda, Ana Paula; Da-Silva, Wagner S; Carvalho, Denise P; De Meis, Leopoldo

2003-01-01

377

Thermal imaging of receptor-activated heat production in single cells.  

PubMed Central

Changes in enthalpy (i.e., heat content) occur during the diverse intracellular chemical and biophysical interactions that take place in the life cycle of biological cells. Such changes have previously been measured for cell suspensions or cell-free biochemical extracts by using microcalorimetry, thermocouples, or pyroelectric films, all of which afford minimal spatial or temporal resolution. Here we present a novel thermal imaging method that combines both diffraction-limited spatial (approximately 300 nm) and sampling-rate-limited time resolution, using the temperature-dependent phosphorescence intensity of the rare earth chelate Eu-TTA (europium (III) thenoyltrifluoro-acetonate). With this thermosensitive dye, we imaged intracellular heat waves evoked in Chinese hamster ovary cells after activation of the metabotropic m1-muscarinic receptor. Fast application of acetylcholine onto the cells evoked a biphasic heat wave that was blocked by atropine, and after a brief delay was followed by a calcium wave. Atropine applied by itself produced a monophasic heat wave in the cells, suggesting that its interactions with the receptor activate some intracellular metabolic pathways. The thermal imaging technique introduced here should provide new insights into cellular functions by resolving the location, kinetics, and quantity of intracellular heat production.

Zohar, O; Ikeda, M; Shinagawa, H; Inoue, H; Nakamura, H; Elbaum, D; Alkon, D L; Yoshioka, T

1998-01-01

378

Suppression of Ca(2+)-dependent heat production in mouse skeletal muscle by high fish oil consumption.  

PubMed

The energy dissipation associated with calcium homeostasis amounts to more than 20% of muscle energy expenditure (EE) at rest and can be quantified from microcalorimetric measurements of heat production in response to chemical modulators of sarcoplasmic reticulum (SR) Ca2+ release. Using this approach, Ca(2+)-dependent heat production in both red- and white-fiber muscles from mice fed a high-fat (HF) diet rich in fish oil was found to be significantly lower than in other groups fed HF diets rich in saturated fat (hydrogenated coconut oil) or n-6 polyunsaturated fats corn oil) and in a group fed a low-fat diet. These findings reveal a potentially specific effect of fish oil on muscle-cell energy metabolism via interference with sarcoplasmic calcium homeostasis, and raise the possibility that modification of the energy cost for intracellular calcium homoeostasis may be a cellular mechanism by which diet could modulate skeletal muscle thermogenesis and whole-body EE. PMID:8052148

Dulloo, A G; Decrouy, A; Chinet, A

1994-08-01

379

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

2005-08-24

380

Fluctuation Theorems for Entropy Production and Heat Dissipation in Periodically Driven Markov Chains  

Microsoft Academic Search

Asymptotic fluctuation theorems are statements of a Gallavotti-Cohen symmetry in the rate function of either the time-averaged\\u000a entropy production or heat dissipation of a process. Such theorems have been proved for various general classes of continuous-time\\u000a deterministic and stochastic processes, but always under the assumption that the forces driving the system are time independent,\\u000a and often relying on the existence

Benjamin Hertz Shargel; Tom Chou

2009-01-01

381

Comparison of chemical properties of food products processed by conventional and ohmic heating  

Microsoft Academic Search

The effect of ohmic and conventional heat processing of different food products on their chemical and physical parameters\\u000a was studied. Depending on the food being analysed, parameters such as pH, total solids, ash, titratable acidity, ascorbic\\u000a acid, total sugars, total fatty acids, total phenolic compounds, and anthocyanins content were determined before and after\\u000a ohmic and conventional pasteurization techniques and the

R. Pereira; M. Pereira; J. A. Teixeira; A. A. Vicente

2007-01-01

382

High frequency core localized modes in neutral beam heated plasmas on TFTR  

SciTech Connect

A band of high frequency modes in the range 50--150 kHz with intermediate toroidal mode numbers 4 < n < 10 are commonly observed in the core of supershot plasmas on TFTR. Two distinct varieties of MHD modes are identified corresponding to a flute-like mode predominantly appearing around the q = 1 surface and an outward ballooning mode for q > 1. The flute-like modes have nearly equal amplitude on the high field and low field side of the magnetic axis and are mostly observed in moderate performance supershot plasmas with {tau}{sub E} < 2{tau}{sub L} while the ballooning-like modes have enhanced amplitude on the low field side of the magnetic axis and tend to appear in higher performance supershot plasmas with {tau}{sub E} > 2{tau}{sub L}, where {tau}{sub L} is the equivalent L-mode confinement time. The modes propagate in the ion diamagnetic drift direction and are highly localized with radial widths {Delta}r {approximately} 5--10 cm, fluctuation levels {tilde n}/n, {tilde T}{sub e}/T{sub e} < 0.01, and radial displacements {zeta}{sub r} {approximately} 0.1 cm. Unlike the toroidally localized high-n activity observed just prior to major and minor disruptions on TFTR, these modes are typically much weaker, more benign, and may be indicative of kinetic ballooning modes destabilized by resonant circulating neutral beam ions.

Nazikian, R.; Chang, Z.; Fredrickson, E.D. [and others

1995-11-01

383

Simulating local measurements on a quantum many-body system with stochastic matrix product states  

SciTech Connect

We demonstrate how to simulate both discrete and continuous stochastic evolutions of a quantum many-body system subject to measurements using matrix product states. A particular, but generally applicable, measurement model is analyzed and a simple representation in terms of matrix product operators is found. The technique is exemplified by numerical simulations of the antiferromagnetic Heisenberg spin-chain model subject to various instances of the measurement model. In particular, we focus on local measurements with small support and nonlocal measurements, which induce long-range correlations.

Gammelmark, Soeren; Moelmer, Klaus [Lundbeck Foundation Theoretical Center for Quantum System Research, Department of Physics and Astronomy, University of Aarhus, DK-8000 Aarhus C (Denmark)

2010-01-15

384

Immunohistochemical localization of different epitopes of advanced glycation end products in human atherosclerotic lesions  

Microsoft Academic Search

To better understand the role of advanced glycation end products (AGEs) in atherogenesis, we developed specific antibodies against different immunological epitopes of AGE structures, including N?-(carboxymethyl)lysine-protein adduct (CML) and a structure(s) other than CML (nonCML), and demonstrated the immunohistochemical localization of CML- and nonCML-epitopes in atherosclerotic lesions of human aorta, which were obtained at autopsy from 20 nondiabetic patients (12

Noriyuki Sakata; Yoshinobu Imanaga; Jing Meng; Yutaka Tachikawa; Shigeo Takebayashi; Ryoji Nagai; Seikoh Horiuchi; Hiroyuki Itabe; Tatsuya Takano

1998-01-01

385

How does the productivity of foreign direct investment spill over to local firms in Chinese manufacturing?  

Microsoft Academic Search

We use a firm-level dataset for Chinese manufacturing, to estimate productivity spillovers from foreign direct investment (FDI) to local firms. The spillover channels considered include inter-firm labour turnover\\/mobility; vertical inputoutput linkages; exporting externalities; and horizontal effects. The roles of these channels are dependent on various factors including export propensity, R&D expenditure per capita, employee training, and ownership structure. We find

Adam Blake; Ziliang Deng; Rod Falvey

2009-01-01

386

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

Microsoft Academic Search

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

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

2007-01-01

387

MTT assay for cell viability: Intracellular localization of the formazan product is in lipid droplets.  

PubMed

Although MTT is widely used to assess cytotoxicity and cell viability, the precise localization of its reduced formazan product is still unclear. In the present study the localization of MTT formazan was studied by direct microscopic observation of living HeLa cells and by colocalization analysis with organelle-selective fluorescent probes. MTT formazan granules did not colocalize with mitochondria as revealed by rhodamine 123 labeling or autofluorescence. Likewise, no colocalization was observed between MTT formazan granules and lysosomes labeled by neutral red. Taking into account the lipophilic character and lipid solubility of MTT formazan, an evaluation of the MTT reaction was performed after treatment of cells with sunflower oil emulsions to induce a massive occurrence of lipid droplets. Under this condition, lipid droplets revealed a large amount of MTT formazan deposits. Kinetic studies on the viability of MTT-treated cells showed no harmful effects at short times. Quantitative structure-activity relations (QSAR) models were used to predict and explain the localization of both the MTT tetrazolium salt and its formazan product. These predictions were in agreement with experimental observations on the accumulation of MTT formazan product in lipid droplets. PMID:22341561

Stockert, Juan C; Blzquez-Castro, Alfonso; Caete, Magdalena; Horobin, Richard W; Villanueva, Angeles

2012-02-15

388

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

SciTech Connect

Eukaryotic gene expression is regulated on different levels ranging from pre-mRNA processing to translation. One of the most characterized families of RNA-binding proteins is the group of hnRNPs: heterogenous nuclear ribonucleoproteins. Members of this protein family play important roles in gene expression control and mRNAs metabolism. In the cytoplasm, several hnRNPs proteins are involved in RNA-related processes and they can be frequently found in two specialized structures, known as GW-bodies (GWbs), previously known as processing bodies: PBs, and stress granules, which may be formed in response to specific stimuli. GWbs have been early reported to be involved in the mRNA decay process, acting as a site of mRNA degradation. In a similar way, stress granules (SGs) have been described as cytoplasmic aggregates, which contain accumulated mRNAs in cells under stress conditions and present reduced or inhibited translation. Here, we characterized the hnRNP Q localization after different stress conditions. hnRNP Q is a predominantly nuclear protein that exhibits a modular organization and several RNA-related functions. Our data suggest that the nuclear localization of hnRNP Q might be modified after different treatments, such as: PMA, thapsigargin, arsenite and heat shock. Under different stress conditions, hnRNP Q can fully co-localize with the endoplasmatic reticulum specific chaperone, BiP. However, under stress, this protein only co-localizes partially with the proteins: GW182 - GWbs marker protein and TIA-1 stress granule component.

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

2009-04-01

389

Thermotolerant bacteriocin-producing lactic acid bacteria isolated from thai local fermented foods and their bacteriocin productivity.  

PubMed

Twenty-one samples of Thai local fermented foods were screened for thermotolerant bacteriocin-producing lactic acid bacteria. From 529 isolates of lactic acid bacteria, 121 isolates were able to inhibit the growth of certain bacterial strains. Of these 121 isolates, only 11 produced antibacterial agents that were capable of inhibiting the growth of multiple bacterial strains in a liquid medium. One strain (KKU 170) of these 11 isolates produced an antibacterial agent that could strongly inhibit the growth of selected strains of gram-positive bacteria including Listeria sp. The antibacterial agent produced by the strain KKU 170 was identified as a bacteriocin since it was inactivated by proteinase K treatment. The strain KKU 170 was identified as Pediococcus acidilactici by both biochemical tests and molecular biological techniques. Optimal production of bacteriocin by the strain KKU 170 was found in culture medium containing 0.2% glucose, at an initial culture pH of 6.5, and temperature of 45 C. The maximum bacteriocin activity (1600 AU ml(-1)) was reached at the late exponential phase of growth and displayed primary metabolite production. The partially purified bacteriocin of the strain KKU 170 was tolerant to heat treatment at 121 C for 30 min. PMID:21467627

Leelavatcharamas, Vichai; Arbsuwan, Nida; Apiraksakorn, Jirawan; Laopaiboon, Pattana; Kishida, Masao

2011-03-01

390

High productivity cultivation of a heat-resistant microalga Chlorella sorokiniana for biofuel production.  

PubMed

To augment biomass and lipid productivities of heterotrophic cultured microalgae Chlorella sorokiniana, the influence of environmental temperature and medium factors, such as carbon source, nitrogen source, and their initial concentrations was investigated in this study. The microalga C. sorokiniana could tolerate up to 42C and showed the highest growth rate of 1.60d(-1) at 37C. The maximum dry cell weight (DCW) and corresponding lipid concentration was obtained with 80gL(-1) of initial glucose and 4gL(-1) of initial KNO3 at 37C. In 5-L batch fermentation, the DCW increased dramatically from 0.9gL(-1) to 37.6gL(-1) in the first 72h cultivation, with the DCW productivity of 12.2gL(-1)d(-1). The maximum lipid content of 31.5% was achieved in 96h and the lipid productivity was 2.9gL(-1)d(-1). The results showed C. sorokiniana could be a promising strain for biofuel production. PMID:23340103

Li, Tingting; Zheng, Yubin; Yu, Liang; Chen, Shulin

2012-12-14

391

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

2012-12-20

392

Effects of solar radiation and wind speed on metabolic heat production by two mammals with contrasting coat colours.  

PubMed

We report the first empirical data describing the interactive effects of simultaneous changes in irradiance and convection on energy expenditure by live mammals. Whole-animal rates of solar heat gain and convective heat loss were measured for representatives of two ground squirrel species, Spermophilus lateralis and Spermophilus saturatus, that contrast in coloration. Radiative heat gain was quantified as the decrease in metabolic heat production caused by the animal's exposure to simulated solar radiation. Changes in convective heat loss were quantified as the variation in metabolic heat production caused by changes in wind speed. For both species, exposure to 780 W m-2 of simulated solar radiation significantly reduced metabolic heat production at all wind speeds measured. Reductions were greatest at lower wind speeds, reaching 42% in S. lateralis and 29% in S. saturatus. Solar heat gain, expressed per unit body surface area, did not differ significantly between the two species. This heat gain equalled 14-21% of the radiant energy intercepted by S. lateralis and 18-22% of that intercepted by S. saturatus. Body resistance, an index of animal insulation, declined by only 10% in S. saturatus and 13% in S. lateralis as wind speed increased from 0.5 to 4.0 ms-1. These data demonstrate that solar heat gain can be essentially constant, despite marked differences in animal coloration, and that variable exposure to wind and sunlight can have important consequences for both thermoregulatory stress experienced by animals and their patterns of energy allocation. PMID:7658187

Walsberg, G E; Wolf, B O

1995-07-01

393

Technological feasibility of heat-irradiation combination treatments for low-acid food products  

NASA Astrophysics Data System (ADS)

Combination processing is the purposeful use of two or more preservation techniques, where their combined effect can be synergistic in creating barriers or hurdles to microbial growth (Day, 1989). The amount of ionising irradiation needed to sterilise low-acid vegetable and starch products (with and without sauces) commercially, generally impairs their sensorial and nutritive qualities, and the use of thermal processes to sterilise these products commercially, may also affect product quality adversely (Kan et al., 1957; Kempe et al., 1957; Kempe, 1960; Langerak and Bruurs, 1973). The use of heat and ionising irradiation in combination can be advantageous, principally by allowing the less severe use of any single treatment, with consequent improvement in product quality (Vas, 1981). A systematic approach to the establishment of optimised combination parameters for heat-irradiation processing to produce high quality shelf-stable, low-acid food products on which future combination processing research and development could be based, is reviewed. In the initial study, mushrooms were chosen as a model system for the following reasons: they are low acid foods (pH > 4.6), have a high intrinsic value and their sensory and nutritional quality is affected adversely by severe processing conditions (Minnaar et al., 1995). Based on gamma D10- values for irradiation and F0-values for heating, the following treatments were selected to produce shelf-stable mushrooms in brine (Minnaar et al., 1992a): Treatment 1: Target F0-value = 8 min; Treatment 2: Target F0-value = 2 min + 2.5 kGy (0C) Treatment 3: Target F0-value = 1 min + 4.5 kGy (0C) Treatment 4: Target F0-value = 0.5 min + 7.5 kGy (-40C) Treatment 5: TargetF0 -value = 0.25 min + 10 kGy (-40C) Treatment 6: Target F0-value = 0.125 min + 20 kGy (-40C) Treatment 7: 45 kGy (-40C). A deliberate attempt was made to explore the full spectrum of possibilities in applying heat processing only (Treatment 1), heat-irradiation combination processing (Treatments 2-6) and irradiation processing (Treatment 7) only. The effects of selected heat, heat-irradiation combination and irradiation treatments on the micro-biological stability and quality of shelf-stable mushrooms in brine stored at ambient temperatures, are discussed. From our results it was concluded that the use of heat-irradiation combination treatments such as target F0- value = 2 min + 2.5 kGy at 0C and/or target F0- value = 1 min + 4.5 kGy at 0C, favouring low irradiation dose levels, offered a feasible alternative to thermally processed or radappertised mushrooms in brine from a quality point of view (Minnaar et al., 1995). In heat-irradiation combination studies of freeze-sensitive, low-acid starchy foods (e.g. rice), the minimum heat treatment required to render a product sufficiently cooked, should be combined with the maximum irradiation dose level that can be applied to the product (not exceeding 10 kGy), without affecting its sensory quality adversely (Minnaar et al., 1995). Based on results obtained from the mushroom study (Minnaar et al., 1992b; Minnaar et al., 1995), the following treatments were selected to produce shelf-stable rice: Treatment 1: Target F0-value = = 6 min; Treatment 2: Target F0-value = 2 min + 2.5 kGy at 0C Treatment 3: Target F0-value = 1 min + 4.5 kGy at 0C Treatment 4: TargetF0 -value = 3 min + 5.5 kGy at 0C Treatment 5: 45 kGy at -40C. The effects of heat, irradiation and heat-irradiation combination treatments on the microbiological safety, microstructure and consumer sensory acceptability and preference of rice are discussed. Our results showed that shelf-stable rice produced by heat-irradiation combination treatments such as target F0-value = 2 min + 2.5 kGy, target F0-value = 1 min + 4.5 kGy and/or target F0-value = 3 min + 5.5 kGy offered a feasible alternative only to radappertised rice from the standpoint of quality. It was established that technical requirements for heat and irradiation processing of a long grain American rice cultivar oppose each other directly, the

Minnaar, A.; Taylor, J. R. N.; Dersley, N. N.; McGill, A. E. J.

1996-09-01

394

Helicobacter pylori heat shock protein B (HspB) localizes in vivo in the gastric mucosa and MALT lymphoma.  

PubMed

Heat shock protein B (HspB) is one of the dominant proteins recognized by most Helicobacter pylori-infected persons and is being considered as potential candidates for subunit vaccines. In the present study we describe the generation of an antibody against HspB and its use in immunohistochemical assays on gastric biopsies. We have demonstrated that our rabbit polyclonal antibody against HspB did not recognize any protein in lysates from a lung human epithelial cell (H1299) line and did not cross-react with the other members of human heat shock proteins. Secondly, we have observed that in gastric biopsies, HspB immunostaining was present inside the cytoplasm of human epithelial cells with a particular localization in the apical portion of gastric epithelial cells other than in the extracellular spaces among gastric cells of human stomach. Finally, we have demonstrated a cytoplasmic HspB immunostaining in groups of neoplastic cells of MALT lymphoma. In conclusion, our observations suggest a possible involvement of HspB in the pathogenesis of H. pylori-related pathologies such as gastritis, ulcer and gastric cancer. PMID:18205181

De Luca, Antonio; De Falco, Maria; Manente, Lucrezia; Dattilo, Doriana; Lucariello, Angela; Esposito, Vincenzo; Gnarini, Mariarosaria; Citro, Gennaro; Baldi, Alfonso; Tufano, Maria Antonietta; Iaquinto, Gaetano

2008-07-01

395

Motion control of single F1-ATPase rotary biomolecular motor using microfabricated local heating devices  

NASA Astrophysics Data System (ADS)

Biomolecular motors are major targets in single-molecule studies, which reveal molecular behaviors usually hidden in the emsemble- and time-averaging of bulk experiments. Methods for rapid experimental condition control during single-biomolecule observation are a key technology to elucidate the molecular mechanisms of proteins. One of the most promising methods is real-time rapid temperature alternation. A microheater and a microthermosensor were integrated on the glass plate for controlling the temperature locally; the maximum response speeds were 71.5 and 56.9 K/s for temperature rise and fall, respectively. Rapid temperature alternation with microfabricated thermodevice allowed rapid and reversible angular velocity control of a single F1-ATPase, a rotary biomolecular motor. The rapid control of the temperature enabled us to perform rotation assay at temperatures higher than that would ``normally'' denature them. This revealed that the torque of F1-ATPase seems to increase at higher temperatures with the increasing rate of 4% per 10 C. This method and knowledge for controlling the biomolecular motor can also be applied to future hybrid organic-inorganic nanosystems, which use biomolecular motors as nanoactuators.

Arata, Hideyuki F.; Noji, Hiroyuki; Fujita, Hiroyuki

2006-02-01

396

Strengths and limitations of localizing food production as a sustainability-building strategy an analysis of bread production on the island of Gotland, Sweden  

Microsoft Academic Search

In this paper we analyze the environmental consequences of local small-scale versus centralized large-scale bread production and the potential for self-sufficiency in bread in a Swedish island community. Mills and bakeries located on the island of Gotland in the Baltic Sea were compared with large-scale production systems on the Swedish mainland. The results show that bread production in local bakeries

sa Sundkvist; AnnMari Jansson; Pia Larsson

2001-01-01

397

Frequency dependence of acoustic distortion products in a locally active model of the cochlea.  

PubMed

In two-tone experiments it has been shown that acoustic distortion products are "tuned" as a function of primary frequency ratio, that is, at a certain frequency ratio a maximum in emission occurs. Several authors maintain that this "tuning" is caused by band-pass filtering of the distortion products as they are coupled back to the basilar membrane. In this paper one possible other cause for this type of tuning is brought to light. It is shown that the same kind of "tuning" is present in a locally active cochlea model without such a filtering of distortion products. In this view "tuning" becomes evident because, when the frequency ratio is near unity, the primary components tend to suppress one another, and suppress the DP, too. PMID:9069623

Kanis, L J; de Boer, E

1997-03-01

398

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

399

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

PubMed

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

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

2013-07-27

400

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

PubMed

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

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

2013-02-01

401

Local renal aldosterone production induces inflammation and matrix formation in kidneys of diabetic rats.  

PubMed

Recently, we reported the presence of a local renal aldosterone production. In the present study, we tested the hypothesis that local aldosterone production in the kidney contributes to renal inflammation, matrix formation and albuminuria associated with diabetes. We evaluated changes in renal aldosterone content (RAC), aldosterone synthase expression, nuclear factor kappaB (NFkappaB), tumour necrosis factor alpha (TNFalpha), interleukin-6 (IL-6), transforming growth factor beta (TGFbeta), glomerular fibronectin, collagen type IV and urinary albumin extraction (UAE) in response to the aldosterone synthase inhibitor FAD286. Studies were conducted in adrenalectomized, normoglycaemic (control) or diabetic rats for 14 weeks. The FAD286 was administered during the last 10 weeks of the study. Plasma aldosterone levels were not detectable in any of the study groups. Compared with control rats, diabetic rats had higher levels of RAC by 488% (P < 0.01), NFkappaB by 293% (P < 0.01), TNFalpha by 356% (P < 0.01), IL-6 by 378% (P < 0.01), TGFbeta by 337% (P < 0.01) and UAE by 1122% (P < 0.01), and increased glomerular fibronectin and collagen type IV immunostaining. In diabetic rats, FAD286 reduced RAC (P < 0.01), UAE (P < 0.05), NFkappaB mRNA, TNFalpha mRNA, IL-6 mRNA and TGFbeta mRNA by 51, 41, 41 and 52% and also their proteins and decreased glomerular fibronectin and collagen type IV immunostaining. In conclusion, diabetes increases local aldosterone production in the kidney, which contributes to development of renal inflammation, matrix formation and albuminuria. Inhibition of aldosterone production in the kidney could be helpful in management of diabetic nephropathy. PMID:18296490

Siragy, Helmy M; Xue, Chun

2008-02-22

402

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

NASA Astrophysics Data System (ADS)

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

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

2011-08-01

403

Xylanase production with xylan rich lignocellulosic wastes by a local soil isolate of Trichoderma viride  

PubMed Central

In the present study, cultural and nutritional conditions for enhanced production of xylanase by a local soil isolate of Trichoderma viride, using various lignocellulosic substrates in submerged culture fermentation have been optimized. Of the lignocellulosics used, maize straw was the best inducer followed by jowar straw for xylanase production. The highest activity achieved was between 14 to 17 days of fermentation. A continuous increase in xylanase production was observed with increasing level of lignocellulosics in the medium and highest activity was observed with maize straw at 5% level. Xylanase production with higher levels of lignocellulosics (3 to 5%) of maize, jowar and barseem was found to be higher as compared to that with commercial xylan as carbon source. Sodium nitrate was the best nitrogen source among the six sources used. Maximum xylanase production was achieved with initial medium pH of 3.54.0 and incubation temperature of 25C.The enzyme preparation was effective in bringing about saccharification of different lignocellulosics. The xylanase production could be further improved by using alkali treated straw as carbon source.

Goyal, Meenakshi; Kalra, K.L.; Sareen, V.K.; Soni, G.

2008-01-01

404

Development of direct resistive heating method for SO 3 decomposition in the SI cycle for hydrogen production  

Microsoft Academic Search

The SulfurIodine (SI) cycle has been considered as one of the efficient and promising thermochemical water-splitting cycles for hydrogen production using nuclear energy. However, the catalytic SO3 decomposition process in the SI cycle demands high temperature heat (>800C). Existing nuclear reactors cannot provide such heat for SO3 decomposition. AECL proposed a direct resistive heating concept to compensate for the requirement

Hongqiang Li; Geng Tan; Wenyu Zhang; Sam Suppiah

2012-01-01

405

Heat-stable toxin production by strains of Bacillus cereus, Bacillus firmus, Bacillus megaterium, Bacillus simplex and Bacillus licheniformis  

Microsoft Academic Search

Strains of Bacillus cereus can produce a heat-stable toxin (cereulide). In this study, 101 Bacillus strains representing 7 Bacillus species were tested for production of heat-stable toxins. Strains of B. megaterium, B. firmus and B. simplex were found to produce novel heat-stable toxins, which showed varying levels of toxicity. B. cereus strains (18 out of 54) were positive for toxin

Janice M. W. Taylor; Alastair D. Sutherland; Kofi E. Aidoo; Niall A. Logan

2005-01-01

406

Two-phase flow of refrigerants in 85 ?m-wide multi-microchannels: Part II Heat transfer with 35 local heaters  

Microsoft Academic Search

This article is the second part of a study on flow boiling of R236fa and R245fa. This part presents the heat transfer coefficients obtained in a 12.7mm silicon evaporator composed of 135 microchannels with 85?m wide and 560?m high channels separated by 46?m wide fins. There were 35 local heaters and temperature measurements arranged in a 57 array. The heat

Etienne Costa-Patry; Jonathan Olivier; Bruno Michel; John Richard Thome

2011-01-01

407

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

408

The distribution of radiogenic heat production as a function of depth in the Sierra Nevada Batholith, California  

NASA Astrophysics Data System (ADS)

Geochemical analyses and geobarometric determinations have been combined to create a depth vs. radiogenic heat production database for the Sierra Nevada batholith, California. This database shows that mean heat production values first increase, then decrease, with increasing depth. Heat production is 2 ?W/m3 within the 3-km-thick volcanic pile at the top of the batholith, below which it increases to an average value of 3.5 ?W/m3 at 5.5 km depth, then decreases to 0.5 1 ?W/m3 at 15 km depth and remains at these values through the entire crust below 15 km. Below the crust, from depths of 40 125 km, the batholith's root and mantle wedge that coevolved beneath the batholith appears to have an average radiogenic heat production rate of 0.14 ?W/m3. This is higher than the rates from most published xenolith studies, but reasonable given the presence of crustal components in the arc root assemblages. The pattern of radiogenic heat production interpreted from the depth vs. heat production database is not consistent with the downward-decreasing exponential distribution predicted from modeling of surface heat flow data. The interpreted distribution predicts a reasonable range of geothermal gradients and shows that essentially all of the present day surface heat flow from the Sierra Nevada could be generated within the 35 km thick crust. This requires a very low heat flux from the mantle, which is consistent with a model of cessation of Sierran magmatism during Laramide flat-slab subduction, followed by conductive cooling of the upper mantle for 70 m.y. The heat production variation with depth is principally due to large variations in uranium and thorium concentration; potassium is less variable in concentration within the Sierran crust, and produces relatively little of the heat in high heat production rocks. Because silica content is relatively constant through the upper 30 km of the Sierran batholith, while U, Th, and K concentrations are highly variable, radiogenic heat production does not vary directly with silica content.

Brady, Robert J.; Ducea, Mihai N.; Kidder, Steven B.; Saleeby, Jason B.

2006-02-01

409

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=10C) 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

410

Modeling multi-keV radiation production of Laser heated Xe filled Be cans  

NASA Astrophysics Data System (ADS)

Recently experiments were performed on the Nova laser to assess using laser heated Xe gas targets for multi-keV radiation production. The targets consists of beryllium cans filled with 1 to 2 atms of Xe gas. When heated, the Xe emits L-shell radiation (n=3-2) into photon energies greater than 4 keV. These underdense radiators are predicted to produce high multi-keV conversion efficiency and have x-ray output duration's longer than conventional sources such as gas bags and foils. The initial experiments did indeed produce high L-shell conversion (>10and spatial extent of the x-ray emission were not what was expected. We present Lasnex simulations used to analyze the current experiments and to aid in the design of the next set of experiments. We find that simple modifications to the targets should greatly improve the performance

Decker, Chris; Suter, Larry; Back, Christina; Grun, Jacob; Laming, Martin; Davis, John

1997-11-01

411

Styles of post-subduction collisional orogeny: Influence of convergence velocity, crustal rheology and radiogenic heat production  

Microsoft Academic Search

A number of models of continental collision already exist, but the role of foregoing oceanic plate subduction or variable coupling between plates still remains to be explored. In addition, heat generation by radioactive decay may be quite variable. For example, our geochemical data from low-to-high grade metamorphic rocks of the Lesser and Higher Himalayan sequences reveal measured heat production values

Manuele Faccenda; Taras V. Gerya; Sumit Chakraborty

2008-01-01

412

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

413

Modelled effects of primary and secondary production enhancement by seamounts on local fish stocks  

NASA Astrophysics Data System (ADS)

This paper addresses how large aggregations of fish found on many seamounts are sustained. We used a generic seamount ecosystem model from the Northeast Atlantic to examine the impact of a potential increase of local primary production on higher trophic levels, to quantify the immigration of allochthonous micronekton that would be required to maintain a "typical" seamount community, and to quantify if the necessary immigration ratios could be supported by local oceanographic conditions. Our simulation predictions indicate a lack of autochthonous resources in the system to support large amounts of seamount aggregating fish. In other words, autochthonous seamount production may be responsible for sustaining only a small amount of its total biomass. Additionally, our study supports the idea that enhancement of primary productivity also cannot sustain large aggregations of seamount fish. Our seamount model, which took into account high abundances of fish, marine mammals, seabirds and tuna, required a total immigration of allochthonous micronekton of 95.2 t km -2 yr -1 less than the potential available biomass after considering the immigration of prey based upon average current velocities and prey standing stocks in oceanic waters. Our model predicted that the horizontal flux of prey would be sufficient to sustain the rich communities living on seamounts.

Morato, Telmo; Bulman, Cathy; Pitcher, Tony J.

2009-12-01

414

Influence of Theobromine on Heat Production and Body Temperatures in Cold-Exposed Humans: A Preliminary Report.  

National Technical Information Service (NTIS)

One of the most successful class of drugs employed to enhance cold tolerance in animals appears to be the methylxanthines. Indeed, methylxanthines such as caffeine, theophylline and theobromine have been shown to increase heat production, delay hypothermi...

A. L. Vallerand I. Jacobs L. C. Wang

1989-01-01

415

Using flowering and heat-loss models for improving greenhouse energy-use efficiency in annual bedding plant production  

Technology Transfer Automated Retrieval System (TEKTRAN)

In temperate climates, annual bedding plants are typically produced in heated greenhouses from late winter through early summer. Temperature, photoperiod, light intensity, and transplant date are commonly manipulated during commercial production so that plants are in flower for predetermined market ...

416

Heat Production Rate as an Indicator of the Ability of Plant Cell to Adapt to Environmental Conditions  

Microsoft Academic Search

The heat production rate in the suspension of unicellular alga (Chlorella vulgaris) was studied by the method of microcalorimetry during adaptation of the alga to stress conditions (NaCl and 45C). The heat production rate slightly increased after the addition of 75 mM NaCl to cell suspension. A two-phase response was observed at 150 and 450 mM NaCl and at elevated

N. L. Loseva; O. A. Kashina; G. G. Rakhimova

2003-01-01

417

Heat production and chemical change during isometric contraction of rat soleus muscle.  

PubMed

1. Methods are described whereby the soleus muscle of the rat may be used for the investigation of initial processes in the absence of oxidative recovery. 2. The anaerobic conditions employed had no effect on the concentration of phosphocreatine in resting muscle or the mechanical response during contraction. 3. Muscles were stimulated tetanically for 10 s at 17-18 degrees C. Measurements were made of the heat production and metabolic changes that occurred during a 13 s period following the first stimulus. 4. There was no detectable change in the concentration of ATP. Neither was there detectable activity of adenylate kinase or adenylate deaminase. The changes in the concentration of glycolytic intermediaries were undetectable or very small. 5. The change in the concentration of phosphocreatine was large and amounted to -127 +/- 11-4 mumol/mmol Ct (mean and S.E. of the mean, negative sign indicates break-down, Ct = free creatine + phosphocreatine) which is equivalent to about -2-13 mumol/g wet weight of muscle. The heat production was 6549 +/- 408 mJ/mmol Ct (mean and S.E. of mean) which is equivalent to about 110 mJ/g. 6. About 30% of the observed energy output is unaccounted for by measured metabolic changes. 7. The ratio of heat production (corrected for small amounts of glycolytic activity) to phosphocreatine hydrolysis was -49-7 +/- 5-6 kJ/mol (mean and S.E. of mean), in agreement with previous results using comparable contractions of frog muscle, but different from the enthalpy change associated with phosphocreatine hydrolysis under in vivo conditions (-34 kJ/mol). 8. The results support the notion that the discrepancy between energy output and metabolism is an indication of an unidentified process of substantial energetic significance that is common to a number of species. PMID:978498

Gower, D; Kretzschmar, K M

1976-07-01

418

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

Microsoft Academic Search

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

Seo Young Kim; Andrey V. Kuznetsov

2003-01-01

419

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

2013-07-08

420

Effect of stress on production of heat labile enterotoxin by Escherichia coli.  

PubMed

Enterotoxigenic Escherichia coli (ETEC) is an important pathogen responsible for secretory diarrhoea. The production of heat labile enterotoxin (LT), by ETEC, is largely responsible for the pathogenesis of diarrhoea. In the present study we investigated the effect of stress factors such as temperature, pH, osmotic stress and nutritional limitation on the production of LT by ETEC using in-house GMI-ELISA. Four strains of E. coli consisting, one standard strain MTCC 723 and three clinical isolates were used in the study. Maximum amount of LT (OD 3.285) was produced at 37 0 C followed by 40 0 C (OD 3.305). Growth of E. coli in medium with pH 8.6 resulted in maximum amount of LT production (OD 3.489). LT was not detectable when bacteria were grown in medium with pH < or =7.2 and > or = 9.2. Sodium chloride concentration of 0.2 M stimulated maximum amount of LT production. Maximum amount of LT was produced when the bacteria were grown in medium containing 2.5 g/l of glucose. All the stress factors had a significant effect on the LT production by E. coli , though quantitative differences in the various strains were observed. PMID:19736401

Hegde, A; Bhat, G K; Mallya, S

421

Effects of pulse-modulated microwave radiation and conventional heating on sperm production  

SciTech Connect

The effects on testicular function of pulse-modulated microwave radiation (PM MWR, 1.3 GHz) and of conventional heating were studied in the rat. Anesthetized adult males (Sprague-Dawley, 400-500 g) were treated then killed at specific intervals with respect to the 13-day cycle of the seminiferous epithelium. PM MWR at 7.7 mW/g (90 min) yielded a modest decline in daily sperm production (DSP) that derived primarily from effects on primary spermatocytes. PM MWR at 4.2 mW/g was ineffective. The mean intratesticular temperature during the former reached 40 degrees C and did not exceed 38 degrees C during the latter. MWR considerably in excess of 7.7 mW/g yielded decrements in virtually all germ cell types, with primary spermatocytes again being most markedly affected. Using conventional heating, intratesticular temperatures in excess of 39 degrees C for 60 min were required for significant decrements in DSP. Levels of circulating follicle-stimulating hormone and of leutinizing hormone were resistant to either treatment. We conclude that the damage threshold and the differential sensitivity of immature germ cells to PM MWR can be adequately explained by the consequent macroscopic heating.

Lebovitz, R.M.; Johnson, L.; Samson, W.K.

1987-01-01

422

Ultrastructural localization of hydrogen peroxide production in ligninolytic Phanerochaete chrysosporium cells  

SciTech Connect

Previous studies have shown that the hydroxyl radical derived from hydrogen peroxide (H2O2) is involved in lignin degradation by Phanerochaete chrysosporium. In the present study, the ultrastructural sites of H2O2 production in ligninolytic cells of P. chrysosporium were demonstrated by cytochemically staining cells with 3,3'-diaminobenzidine (DAB). Hydrogen peroxide production, as evidenced by the presence of oxidized DAB deposits, appeared to be localized in the periplasmic space of cells from ligninolytic cultures grown for 14 days in nitrogen-limited medium. When identical cells were treated with DAB in the presence of aminotriazole, periplasmic deposits of oxidized DAB were not observed, suggesting that the deposits resulted from H2O2-dependent peroxidatic oxidation of DAB by catalase. Cells from cultures grown for 3 or 6 days in nitrogen-limited medium or for 14 days in nitrogen- sufficient medium had little ligninolytic activity and low specific activity for H202 production and did not contain periplasmic oxidized DAB deposits. The results suggest that in cultures grown in nitrogen- limited medium, there is a positive correlation between the occurrence of oxidized DAB deposits, the specific activity for H2O2 production in cell extracts, and ligninolytic activity. (Refs. 25).

Forney, L.J.; Reddy, C.A.; Pankratz, H.S.

1982-09-01

423</