WorldWideScience

Sample records for heat loss responses

  1. Can intradermal administration of angiotensin II influence human heat loss responses during whole body heat stress?

    Science.gov (United States)

    Fujii, Naoto; Meade, Robert D; Paull, Gabrielle; McGinn, Ryan; Foudil-bey, Imane; Akbari, Pegah; Kenny, Glen P

    2015-05-01

    It is unclear if angiotensin II, which can increase the production of reactive oxygen species (oxidative stress), modulates heat loss responses of cutaneous blood flow and sweating. We tested the hypothesis that angiotensin II-induced increases in oxidative stress impair cutaneous perfusion and sweating during rest and exercise in the heat. Eleven young (24 ± 4 yr) healthy adults performed two 30-min cycling bouts at a fixed rate of metabolic heat production (400 W) in the heat (35°C). The first and second exercises were followed by a 20- and 40-min recovery. Four microdialysis fibers were placed in the forearm skin for continuous administration of either: 1) lactated Ringer (control), 2) 10 μM angiotensin II, 3) 10 mM ascorbate (an antioxidant), or 4) a combination of 10 μM angiotensin II + 10 mM ascorbate. Cutaneous vascular conductance (CVC; laser-Doppler perfusion units/mean arterial pressure) and sweating (ventilated capsule) were evaluated at each skin site. Compared with control, angiotensin II reduced both CVC and sweating at baseline resting and during each recovery in the heat (all P 0.05). When ascorbate was coinfused with angiotensin II, the effect of angiotensin II on sweating was abolished (all P > 0.05); however, its effect on CVC at baseline resting and during each recovery remained intact (all P stress, while it impairs sweating through increasing oxidative stress during exposure to an ambient heat stress before and following exercise. Copyright © 2015 the American Physiological Society.

  2. Physiological Responses and Lactation to Cutaneous Evaporative Heat Loss in , , and Their Crossbreds

    Directory of Open Access Journals (Sweden)

    Wang Jian

    2015-11-01

    Full Text Available Cutaneous evaporative heat loss in Bos indicus and Bos taurus has been well documented. Nonetheless, how crossbreds with different fractional genetic proportions respond to such circumstances is of interest. A study to examine the physiological responses to cutaneous evaporative heat loss, also lactation period and milk yield, were conducted in Sahiwal (Bos indicus, n = 10, 444±64.8 kg, 9±2.9 years, Holstein Friesian (Bos taurus, HF100% (n = 10, 488±97.9 kg, 6±2.8 years and the following crossbreds: HF50% (n = 10, 355±40.7 kg, 2±0 years and HF87.5% (n = 10, 489±76.8 kg, 7±1.8 years. They were allocated so as to determine the physiological responses of sweating rate (SR, respiration rate (RR, rectal temperature (RT, and skin temperature (ST with and without hair from 06:00 h am to 15:00 h pm. And milk yield during 180 days were collected at days from 30 to 180. The ambient temperature-humidity-index (THI increased from less than 80 in the early morning to more than 90 in the late afternoon. The interaction of THI and breed were highly affected on SR, RR, RT, and ST (p0.05 but did change over time. The ST with and without hair were similar, and was higher in HF100% (37.4°C; 38.0°C and their crossbred HF50% (35.5°C; 35.5°C and HF87.5% (37.1°C; 37.9°C than Sahiwal (34.8°C; 34.8°C (p<0.01. Moreover, the early lactation were higher at HF100% (25 kg and 87.5% (25 kg than HF50% (23 kg which were higher than Sahiwal (18 kg while the peak period of lactation was higher at HF100% (35 kg than crossbreds both HF87.5% and HF50% (32 kg which was higher than Sahiwal (26 kg (p<0.05. In conclusion, sweating and respiration were the main vehicle for dissipating excess body heat for Sahiwal, HF and crossbreds, respectively. The THI at 76 to 80 were the critical points where the physiological responses to elevated temperature displayed change.

  3. Heat loss from Buildings

    DEFF Research Database (Denmark)

    Karlsson, Kenneth; Næraa, Rikke

    1997-01-01

    Determination of heat loss coefficients for buildings in Denmark. The coefficient are determined for 15 building groups and 3 year intervals. They are based on the BBR-registre and assumptions of U-values(W/K*m2)and computed in a simple spreed sheet model.The results are used in the REVEILLE...

  4. Turbulent energy losses during orchard heating

    Energy Technology Data Exchange (ETDEWEB)

    Bland, W.L.

    1979-01-01

    Two rapid-response drag anemometers and low time constant thermocouples, all at 4 m above a heated orchard floor, sampled wind component in the vertical direction and temperature at 30 Hz. The turbulent heat flux calculated revealed not more than 10% of the heat lost from the orchard was via turbulent transort. The observations failed to support previous estimates that at least a third of the energy applied was lost through turbulent transport. Underestimation of heat loss due to mean flow and a newly revealed flux due to spatial variations in the mean flow may explain the unaccounted for loss.

  5. 24 CFR 3280.506 - Heat loss/heat gain.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 5 2010-04-01 2010-04-01 false Heat loss/heat gain. 3280.506... URBAN DEVELOPMENT MANUFACTURED HOME CONSTRUCTION AND SAFETY STANDARDS Thermal Protection § 3280.506 Heat loss/heat gain. The manufactured home heat loss/heat gain shall be determined by methods outlined in...

  6. Psychophysical and cerebral responses to heat stimulation in patients with central pain, painless central sensory loss, and in healthy persons.

    Science.gov (United States)

    Casey, Kenneth L; Geisser, Michael; Lorenz, Jürgen; Morrow, Thomas J; Paulson, Pamela; Minoshima, Satoshi

    2012-02-01

    Patients with central pain (CP) typically have chronic pain within an area of reduced pain and temperature sensation, suggesting an impairment of endogenous pain modulation mechanisms. We tested the hypothesis that some brain structures normally activated by cutaneous heat stimulation would be hyperresponsive among patients with CP but not among patients with a central nervous system lesion causing a loss of heat or nociceptive sensation with no pain (NP). We used H(2)(15)O positron emission tomography to measure, in 15 healthy control participants, 10 NP patients, and 10 CP patients, increases in regional cerebral blood flow among volumes of interest (VOI) from the resting (no stimulus) condition during bilateral contact heat stimulation at heat detection, heat pain threshold, and heat pain tolerance levels. Both patient groups had a reduced perception of heat intensity and unpleasantness on the clinically affected side and a bilateral impairment of heat detection. Compared with the HC group, both NP and CP patients had more hyperactive and hypoactive VOI in the resting state and more hyperresponsive and hyporesponsive VOI during heat stimulation. Compared with NP patients, CP patients had more hyperresponsive VOI in the intralaminar thalamus and sensory-motor cortex during heat stimulation. Our results show that focal CNS lesions produce bilateral sensory deficits and widespread changes in the nociceptive excitability of the brain. The increased nociceptive excitability within the intralaminar thalamus and sensory-motor cortex of our sample of CP patients suggests an underlying pathophysiology for the pain in some central pain syndromes. Published by Elsevier B.V.

  7. Winter-regime surface heat loss from heated streams

    International Nuclear Information System (INIS)

    Paily, P.P.; Macagno, E.O.; Kennedy, J.F.

    1974-01-01

    Evaluation of the rate of surface heat exchange between the water and air is a significant factor in any study of the thermal response of heated streams to heat inputs. Existing methods to determine the amount of heat transfer across the water surface are surveyed, and the different formulas developed for determining the heat exchange components are compiled. Heat-transfer models that have been proposed in the literature are reviewed, and a new linearized model for determining the rate of surface heat exchange is proposed. Generalized relations between the major climatological factors and the coefficients of the linearized heat-loss rate are established by multiple-regression analysis. The analysis is limited to cold-period conditions, in the sense that air temperatures below the freezing point of water only are considered in developing the regression equations. A computer program, using FORTRAN, is presented which enables the computation of the coefficients appearing in the linearized heat-loss rate for all combinations of the various climatological factors

  8. A study on emergency response guideline during the loss of steam generator secondary heat sink in pressurizer water reactor

    International Nuclear Information System (INIS)

    Yoon, D. J.; Lee, J. Y.; Song, D. S.

    1999-01-01

    A loss of secondary heat sink can occur as a result of several different initiating events, which are a loss of main feedwater during power operation, a loss of off-site power, or any other scenario for which main feedwater is isolated or lost. At this point the opening and closing of the PORV or safety valves will result in a loss of RCS inventory similar in nature to a small break loss of coolant accident. If operator action is not taken, the pressurizer PORV or safety valves will continue to cycle open and closed at the valve setpoint pressure removing RCS inventory and a limited amount of core decay heat until eventually enough inventory will be lost to result in core uncovery. We conclude that a requirement to successfully initiate bleed and feed on steam generator dryout, without any significant core uncovery expected to occur, is that the PORV flow to power ratio must exceed 140 (lbm/hr)/Mwt. For all plants whose PORV capacity is less than 140 (lbm/hr)/Mwt, since symptoms of SG dryout cannot be used to initiate bleed and feed, increasing RCS pressure and temperature or pressure greater than 2335 psig cannot be used. The only alternative symptom available is SG narrow range level. Since Kori 1,2,3 and 4' PORV capacity is more than the criteria, the bleed and feed operation can be initiated at steam generator dryout

  9. Heat loss from an open cavity

    Energy Technology Data Exchange (ETDEWEB)

    McDonald, C.G. [California State Polytechnic Univ., Pomona, CA (United States). Coll. of Engineering

    1995-12-01

    Cavity type receivers are used extensively in concentrating solar thermal energy collecting systems. The Solar Total Energy Project (STEP) in Shenandoah, Georgia is a large scale field test for the collection of solar thermal energy. The STEP experiment consists of a large field array of solar collectors used to supplement the process steam, cooling and other electrical power requirements of an adjacent knitwear manufacturing facility. The purpose of the tests, conducted for this study, was to isolate and quantify the radiative, conductive, and convective components of total heat loss, and to determine the effects of operating temperature, receiver angle, and aperture size on cavity heat loss. An analytical model for radiative heat loss was developed and compared with two other methods used to determine radiative heat loss. A proposed convective heat loss correlation, including effects of aperture size, receiver operating temperature, and receiver angle is presented. The resulting data is a source to evaluate the STEP measurements.

  10. Body temperature depression and peripheral heat loss accompany the metabolic and ventilatory responses to hypoxia in low and high altitude birds.

    Science.gov (United States)

    Scott, Graham R; Cadena, Viviana; Tattersall, Glenn J; Milsom, William K

    2008-04-01

    The objectives of this study were to compare the thermoregulatory, metabolic and ventilatory responses to hypoxia of the high altitude bar-headed goose with low altitude waterfowl. All birds were found to reduce body temperature (T(b)) during hypoxia, by up to 1-1.5 degrees C in severe hypoxia. During prolonged hypoxia, T(b) stabilized at a new lower temperature. A regulated increase in heat loss contributed to T(b) depression as reflected by increases in bill surface temperatures (up to 5 degrees C) during hypoxia. Bill warming required peripheral chemoreceptor inputs, since vagotomy abolished this response to hypoxia. T(b) depression could still occur without bill warming, however, because vagotomized birds reduced T(b) as much as intact birds. Compared to both greylag geese and pekin ducks, bar-headed geese required more severe hypoxia to initiate T(b) depression and heat loss from the bill. However, when T(b) depression or bill warming were expressed relative to arterial O(2) concentration (rather than inspired O(2)) all species were similar; this suggests that enhanced O(2) loading, rather than differences in thermoregulatory control centres, reduces T(b) depression during hypoxia in bar-headed geese. Correspondingly, bar-headed geese maintained higher rates of metabolism during severe hypoxia (7% inspired O(2)), but this was only partly due to differences in T(b). Time domains of the hypoxic ventilatory response also appeared to differ between bar-headed geese and low altitude species. Overall, our results suggest that birds can adjust peripheral heat dissipation to facilitate T(b) depression during hypoxia, and that bar-headed geese minimize T(b) and metabolic depression as a result of evolutionary adaptations that enhance O(2) transport.

  11. Ion heat conduction losses in Extrap

    International Nuclear Information System (INIS)

    Tennfors, E.

    1989-08-01

    The classical ion heat conduction losses in Extrap discharges are calculated using polynomial magnetic field profiles and compared to the power input. For polynomials matched to magnetic field profiles measured in present experiments, these losses are small. By varying the coefficients of the polynomials, a region is found, where the power input can balance the classical heat conduction losses. Each set of coefficients corresponds to values of the parameters F and Θ used in RFP physics. The region determines a region in an F-Θ diagram, including the usual RFP region but extending to higher values of Θ and βΘ

  12. Targeting the maximum heat recovery for systems with heat losses and heat gains

    International Nuclear Information System (INIS)

    Wan Alwi, Sharifah Rafidah; Lee, Carmen Kar Mun; Lee, Kim Yau; Abd Manan, Zainuddin; Fraser, Duncan M.

    2014-01-01

    Graphical abstract: Illustration of heat gains and losses from process streams. - Highlights: • Maximising energy savings through heat losses or gains. • Identifying location where insulation can be avoided. • Heuristics to maximise heat losses or gains. • Targeting heat losses or gains using the extended STEP technique and HEAT diagram. - Abstract: Process Integration using the Pinch Analysis technique has been widely used as a tool for the optimal design of heat exchanger networks (HENs). The Composite Curves and the Stream Temperature versus Enthalpy Plot (STEP) are among the graphical tools used to target the maximum heat recovery for a HEN. However, these tools assume that heat losses and heat gains are negligible. This work presents an approach that considers heat losses and heat gains during the establishment of the minimum utility targets. The STEP method, which is plotted based on the individual, as opposed to the composite streams, has been extended to consider the effect of heat losses and heat gains during stream matching. Several rules to guide the proper location of pipe insulation, and the appropriate procedure for stream shifting have been introduced in order to minimise the heat losses and maximise the heat gains. Application of the method on two case studies shows that considering heat losses and heat gains yield more realistic utility targets and help reduce both the insulation capital cost and utility cost of a HEN

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

    Science.gov (United States)

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

    2016-04-01

    This study investigates the effects of operative temperature on the local and total heat losses, and the relationship between the heat loss and thermal sensation. 10 local parts of head, neck, chest, abdomen, upper arm, forearm, hand, thigh, leg and foot are selected. In all these parts, convection, radiation, evaporation, respiration, conduction and diffusion heat losses are analyzed when operative temperature is 23, 28, 33 and 37 °C. The local heat losses show that the radiation and convection heat losses are mainly affected by the area of local body, and the heat loss of the thigh is the most in the ten parts. The evaporation heat loss is mainly affected by the distribution of sweat gland, and the heat loss of the chest is the most. The total heat loss of the local body shows that in low temperature, the thigh, leg and chest have much heat loss, while in high temperature, the chest, abdomen, thigh and head have great heat loss, which are useful for clothing design. The heat losses of the whole body show that as the operative temperature increases, the radiation and convection heat losses decrease, the heat losses of conduction, respiration, and diffusion are almost constant, and the evaporation heat loss increases. By comparison, the heat loss ratios of the radiation, convection and sweat evaporation, are in agreement with the previous researches. At last, the formula about the heat loss ratio of convection and radiation is derived. It's useful for thermal comfort evaluation and HVAC (heating, ventilation and air conditioning) design. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. Analysis of decay heat removal following loss of RHR

    International Nuclear Information System (INIS)

    Naff, S.A.; Ward, L.W.

    1991-01-01

    Recent plant experience has included many events occurring during outages at pressurized water reactors. A recent example is the loss of residual heat removal system event that occurred March 20, 1990 at the Vogtle-1 plant following refueling. Plant conditions during outages differ markedly from those prevailing at normal full-power operation on which most past research has concentrated. Specifically, during outages the core power is low, the coolant system may be in a drained state with air or nitrogen present, and various reactor coolant system closures may be unsecured. With the residual heat removal system operating, the core decay heat is readily removed. However, if the residual heat removal system capability is lost and alternative heat removal means cannot be established, heat up of the coolant could lead to core coolant boil-off, fuel rod heat up, and core damage. A study was undertaken by the Nuclear Regulatory Commission to identify what information was needed to understand pressurized water reactor response to an extended loss of residual heat removal event during refueling and maintenance outages. By identifying the possible plant conditions and cooling methods that might be used, the controlling thermal-hydraulic processes and phenomena were identified. Controlling processes and phenomena include: gravity drain into the reactor coolant system, core water boil-off, and reflux condensation cooling processes

  15. Analysis of the internal heat losses in a thermoelectric generator

    DEFF Research Database (Denmark)

    Bjørk, Rasmus; Christensen, Dennis Valbjørn; Eriksen, Dan

    2014-01-01

    and radiative heat losses, including surface to surface radiation. For radiative heat losses it is shown that for the temperatures considered here, surface to ambient radiation is a good approximation of the heat loss. For conductive heat transfer the module efficiency is shown to be comparable to the case...... of radiative losses. Finally, heat losses due to internal natural convection in the module is shown to be negligible for the millimetre sized modules considered here. The combined case of radiative and conductive heat transfer resulted in the lowest efficiency. The optimized load resistance is found...... to decrease for increased heat loss. The leg dimensions are varied for all heat losses cases and it is shown that the ideal way to construct a TEG module with minimal heat losses and maximum efficiency is to either use a good insulating material between the legs or evacuate the module completely, and use...

  16. Heat losses in power boilers caused by thermal bridges

    Directory of Open Access Journals (Sweden)

    Kocot Monika

    2017-01-01

    Full Text Available In this article the analysis of heat losses caused by thermal bridges that occur in the steam boiler OP-140 is presented. Identification of these bridges were conducted with use of thermographic camera. Heat losses were evaluated based on methodology of VDI 4610 standard, but instead of its simplified equations, criterial equations based on Nusselt number were used. Obtained values of annual heat losses and heat flux density corresponding to the fully insulated boiler surfaces were compared to heat losses generated by thermal bridges located in the same areas. The emphasis is put on the role of industrial insulation in heat losses reduction.

  17. Heat loss by helicity injection in spheromaks

    International Nuclear Information System (INIS)

    Fowler, T.K.

    1994-01-01

    A model is presented for spheromak buildup and decay including thermal diffusivity associated with magnetic turbulence during helicity injection. It is shown that heat loss by magnetic turbulence scales more favorably than gyroBohm transport. Thus gyroBohm scaling for the proposed ignition experiment would be the conservative choice, though present experiments may be dominated by magnetic turbulence. Because of a change in boundary conditions when the gun is turned off, the model may account for the observed increase in electron temperature in CTX after turnoff

  18. Chlorophyll loss associated with heat-induced senescence in bentgrass.

    Science.gov (United States)

    Jespersen, David; Zhang, Jing; Huang, Bingru

    2016-08-01

    Heat stress-induced leaf senescence is characterized by the loss of chlorophyll from leaf tissues. The objectives of this study were to examine genetic variations in the level of heat-induced leaf senescence in hybrids of colonial (Agrostis capillaris)×creeping bentgrass (Agrostis stolonifera) contrasting in heat tolerance, and determine whether loss of leaf chlorophyll during heat-induced leaf senescence was due to suppressed chlorophyll synthesis and/or accelerated chlorophyll degradation in the cool-season perennial grass species. Plants of two hybrid backcross genotypes ('ColxCB169' and 'ColxCB190') were exposed to heat stress (38/33°C, day/night) for 28 d in growth chambers. The analysis of turf quality, membrane stability, photochemical efficiency, and chlorophyll content demonstrated significant variations in the level of leaf senescence induced by heat stress between the two genotypes, with ColXCB169 exhibiting a lesser degree of decline in chlorophyll content, photochemical efficiency and membrane stability than ColXCB190. The assays of enzymatic activity or gene expression of several major chlorophyll-synthesizing (porphobilinogen deaminase, Mg-chelatase, protochlorophyllide-reductase) and chlorophyll-degrading enzymes (chlorophyllase, pheophytinase, and chlorophyll-degrading peroxidase) indicated heat-induced decline in leaf chlorophyll content was mainly due to accelerated chlorophyll degradation, as manifested by increased gene expression levels of chlorophyllase and pheophytinase, and the activity of pheophytinase (PPH), while chlorophyll-synthesizing genes and enzymatic activities were not differentially altered by heat stress in the two genotypes. The analysis of heat-induced leaf senescence of pph mutants of Arabidopsis further confirmed that PPH could be one enzymes that plays key roles in regulating heat-accelerated chlorophyll degradation. Further research on enzymes responsible in part for the loss of chlorophyll during heat

  19. Impact of Next Generation District Heating Systems on Distribution Network Heat Losses: A Case Study Approach

    Science.gov (United States)

    Li, Yu; Rezgui, Yacine

    2018-01-01

    District heating (DH) is a promising energy pathway to alleviate environmental negative impacts induced by fossil fuels. Improving the performance of DH systems is one of the major challenges facing its wide adoption. This paper discusses the heat losses of the next generation DH based on the constructed Simulink model. Results show that lower distribution temperature and advanced insulation technology greatly reduce network heat losses. Also, the network heat loss can be further minimized by a reduction of heat demand in buildings.

  20. RCS pressure under reduced inventory conditions following a loss of residual heat removal

    International Nuclear Information System (INIS)

    Palmrose, D.E.; Hughes, E.D.; Johnsen, G.W.

    1992-01-01

    The thermal-hydraulic response of a closed-reactor coolant system to loss of residual heat removal (RHR) cooling is investigated. The processes examined include: core coolant boiling and steam generator reflux condensation, pressure increase on the primary side, heat transfer mechanisms on the steam generator primary and secondary sides, and effects of noncondensible gas on heat transfer processes

  1. TIDALLY HEATED TERRESTRIAL EXOPLANETS: VISCOELASTIC RESPONSE MODELS

    International Nuclear Information System (INIS)

    Henning, Wade G.; O'Connell, Richard J.; Sasselov, Dimitar D.

    2009-01-01

    Tidal friction in exoplanet systems, driven by orbits that allow for durable nonzero eccentricities at short heliocentric periods, can generate internal heating far in excess of the conditions observed in our own solar system. Secular perturbations or a notional 2:1 resonance between a hot Earth and hot Jupiter can be used as a baseline to consider the thermal evolution of convecting bodies subject to strong viscoelastic tidal heating. We compare results first from simple models using a fixed Quality factor and Love number, and then for three different viscoelastic rheologies: the Maxwell body, the Standard Anelastic Solid (SAS), and the Burgers body. The SAS and Burgers models are shown to alter the potential for extreme tidal heating by introducing the possibility of new equilibria and multiple response peaks. We find that tidal heating tends to exceed radionuclide heating at periods below 10-30 days, and exceed insolation only below 1-2 days. Extreme cases produce enough tidal heat to initiate global-scale partial melting, and an analysis of tidal limiting mechanisms such as advective cooling for earthlike planets is discussed. To explore long-term behaviors, we map equilibria points between convective heat loss and tidal heat input as functions of eccentricity. For the periods and magnitudes discussed, we show that tidal heating, if significant, is generally detrimental to the width of habitable zones.

  2. Individual heat stress response

    NARCIS (Netherlands)

    Havenith, G.

    1997-01-01

    In 5 experiments, heterogeneous subject groups (large variations in _VO2 max, regular daily activity level, mass, body surface area (AD), % body fat, and AD/mass ratio) were tested for their physiological response while exercising on a cycle ergometer at a relative (45% _VO2 max; REL) or an absolute

  3. Effect of human skin grafts on whole-body heat loss during exercise heat stress: a case report.

    Science.gov (United States)

    Ganio, Matthew S; Gagnon, Daniel; Stapleton, Jill; Crandall, Craig G; Kenny, Glen P

    2013-01-01

    When exposed to heat stress, increases in cutaneous blood flow and sweating in well-healed grafted skin are severely attenuated, which could impair whole-body heat loss if skin grafts cover a large portion of total body surface area (TBSA). It is unknown to what extent whole-body heat loss is impaired when skin grafts cover a significant (eg, >50%) proportion of TBSA. The authors examined whole-body heat exchange during and after 60 min of cycling exercise in the heat (35°C; 25% relative humidity), at a fixed rate of metabolic heat production (~400 W) in a woman (age, 36 years; mass, 78.2 kg) with well-healed (17+ years) skin grafts covering 75% of TBSA. Her responses were compared with two noninjured control subjects. Whole-body evaporative and dry heat exchange were measured by direct calorimetry. While exercising in the same ambient conditions and at the same rate of heat production, relative evaporative heat loss of nongrafted skin in the grafted subject (ie, evaporative heat loss per m) was nearly twice that of the control subjects. However, total rate of evaporative heat loss reached only 59% of the amount required for heat balance in the skin-grafted subject compared with 92 ± 3% in controls. Thus, the increase in core temperature was 2-fold greater for the grafted (1.22°C) vs control (0.61 ± 0.19°C) individuals. This case study demonstrates that a large area of grafted skin greatly diminishes maximum evaporative heat loss during exercise in the heat, making a compensable environment for control subjects uncompensable for skin-grafted individuals.

  4. Self-heating, gamma heating and heat loss effects on resistance temperature detector (RTD) accuracy

    International Nuclear Information System (INIS)

    Qian, T.; Hinds, H.W.; Tonner, P.

    1997-01-01

    Resistance temperature detectors (RTDs) are extensively used in CANDU nuclear power stations for measuring various process and equipment temperatures. Accuracy of measurement is an important performance parameter of RTDs and has great impact on the thermal power efficiency and safety of the plant. There are a number of factors that contribute to some extent to RTD measurement error. Self-heating, gamma heating and the heat-loss throughout conduction of the thermowell are three of these factors. The degree to which these three affect accuracy of RTDs used for the measurement of reactor inlet header temperature (RIHT) has been analyzed and is presented in this paper. (author)

  5. Heat losses through pipe connections in hot water stores

    DEFF Research Database (Denmark)

    Andersen, Elsa; Fan, Jianhua; Furbo, Simon

    2007-01-01

    The heat loss from pipe connections at the top of hot water storage tanks with and without a heat trap is investigated theoretically and compared to similar experimental investigations. Computational Fluid Dynamics (CFD) is used for the theoretical analysis. The investigations show that the heat...... loss from an ideally insulated pipe connected to the top of a hot water tank is mainly due to a natural convection flow in the pipe, that the heat loss coefficient of pipes connected to the top of a hot water tank is high, and that a heat trap can reduce the heat loss coefficient significantly. Further......, calculations show that the yearly thermal performance of solar domestic hot water systems is strongly reduced if the hot water tank has a thermal bridge located at the top of the tank....

  6. Heat loss investigation from spherical cavity receiver of solar concentrator

    Energy Technology Data Exchange (ETDEWEB)

    Shewale, V. C. [Dept. of Mechanical Engineering, NDMVPS KBT College of Engineering, Nashik (India); Dongarwar, P. R. [Dept. of Mechanical Engineering, College of Military Engineering, Pune (India); Gawande, R. P. [Dept. of Mechanical Engineering, B.D.C.O.E. Wardha, Nagpur University, NagpurI (India)

    2016-11-15

    The heat losses are mainly affects on the performance of cavity receiver of solar concentrator. In this paper, the experimental and numerical study is carried out for different heat losses from spherical cavity receiver of 0.385 m cavity diameter and 0.154 m opening diameter. The total and convection losses are studied experimentally to no wind and wind conditions for the temperature range of 150 °C to 300 °C at 0°, 30°, 45°, 60° and 90° inclination angle of cavity receiver. The experimental set up mainly consists of copper tube material cavity receiver wrapped with nichrome heating coil to heat the cavity and insulated with glasswool insulation. The numerical analysis was carried out with Fluent Computational fluid dynamics (CFD) software, to study connective heat losses for no wind condition only. The numerical results are compared with experimental results and found good agreement with maximum deviation of 12 %. The effect of inclination angle of cavity receiver on total losses and convection losses shows that as the inclination angle increases from 0o to 90o, both losses decreased due to decreased in convective zone into the cavity receiver. The effect of operating temperature of cavity shows that as the temperature of cavity receiver increases, the total and convective losses goes on increasing. The effect of external wind at 2 m/s and 4 m/s in two directions (side-on wind and head-on wind) is also studied experimentally for total and convective heat losses. The result shows that the heat losses are higher for head-on wind condition compared to side-on wind and no wind condition at all inclination angle of cavity receiver. The present results are also compared to the convective losses obtained from the correlations of Stine and Mcdonald and M. Prakash. The convective loss from these correlations shows nearest prediction to both experimental and numerical results.

  7. Heat loss investigation from spherical cavity receiver of solar concentrator

    International Nuclear Information System (INIS)

    Shewale, V. C.; Dongarwar, P. R.; Gawande, R. P.

    2016-01-01

    The heat losses are mainly affects on the performance of cavity receiver of solar concentrator. In this paper, the experimental and numerical study is carried out for different heat losses from spherical cavity receiver of 0.385 m cavity diameter and 0.154 m opening diameter. The total and convection losses are studied experimentally to no wind and wind conditions for the temperature range of 150 °C to 300 °C at 0°, 30°, 45°, 60° and 90° inclination angle of cavity receiver. The experimental set up mainly consists of copper tube material cavity receiver wrapped with nichrome heating coil to heat the cavity and insulated with glasswool insulation. The numerical analysis was carried out with Fluent Computational fluid dynamics (CFD) software, to study connective heat losses for no wind condition only. The numerical results are compared with experimental results and found good agreement with maximum deviation of 12 %. The effect of inclination angle of cavity receiver on total losses and convection losses shows that as the inclination angle increases from 0o to 90o, both losses decreased due to decreased in convective zone into the cavity receiver. The effect of operating temperature of cavity shows that as the temperature of cavity receiver increases, the total and convective losses goes on increasing. The effect of external wind at 2 m/s and 4 m/s in two directions (side-on wind and head-on wind) is also studied experimentally for total and convective heat losses. The result shows that the heat losses are higher for head-on wind condition compared to side-on wind and no wind condition at all inclination angle of cavity receiver. The present results are also compared to the convective losses obtained from the correlations of Stine and Mcdonald and M. Prakash. The convective loss from these correlations shows nearest prediction to both experimental and numerical results

  8. Heat Loss Evaluation of the SMART-ITL Primary System

    International Nuclear Information System (INIS)

    Ryu, Sung Uk; Bae, Hwang; Kim, Dong Eok; Park, Keun Tae; Park, Hyun Sik; Yi, Sung Jae

    2013-01-01

    It is considered that the heat loss rate is one of the critical factors affecting the transient behavior of an integral effect test facility. This paper presents the experimental results of the heat loss rate for the primary system of a SMART-ITL (System-Integrated Modular Advanced ReacTor-Integral Test Loop) facility including the pressurizer (PZR). To evaluate the heat loss rate of the primary system, two different approaches were pursued, i. e., integral and differential approaches. The integral approach is a constant temperature method which controls the core and PZR powers at a desired temperature condition and the differential approach is a natural cooling-down measurement method that lasts for a long period of time. In the present work, the heat losses derived from integral and differential approaches were acquired for the primary system of the SMART-ITL. The results obtained by the two approaches were very similar. In addition, an empirical correlation with respect to the difference between the wall temperature and the ambient temperature was proposed to represent the heat loss characteristics of the SMART-ITL facility. The estimated heat losses could be used to estimate the heat loss during the tests and code simulations

  9. Improving MODPRESS heat loss calculations for PWR pressurizers

    International Nuclear Information System (INIS)

    Ramos, Natalia V.; Lira, Carlos A. Brayner O.; Castrillho, Lazara S.

    2009-01-01

    The improvement of heat loss calculations in MODPRESS transient code for PWR pressurizer analysis is the main focus of this investigation. Initially, a heat loss model was built based on heat transfer coefficient (HTC) correlations obtained in handbooks of thermal engineering. A hand calculation for Neptunus experimental test number U47 yielded a thermal power loss of 11.2 kW against 17.3 kW given by MODPRESS at the same conditions, while the experimental estimate is given as 17 kW. This comparison is valid only for steady state or before starting the transient experiment, because MODPRESS does not update HTC's when the transient phase begins. Furthermore, it must be noted that MODPRESS heat transfer coefficients are adjusted to reproduce the experimental value of the specific type of pressurizer. After inserting the new routine for HTC's into MODPRESS, the heat loss was calculated as 11.4 kW, a value very close to the first estimate but far below 17 kW found in the U47 experiment. In this paper, the heat loss model and results will be described. Further research is being developed to find a more general HTC that allows the analysis of the effects of heat losses on transient behavior of Neptunus and IRIS pressurizers. (author)

  10. Indoor temperatures for calculating room heat loss and heating capacity of radiant heating systems combined with mechanical ventilation systems

    DEFF Research Database (Denmark)

    Wu, Xiaozhou; Olesen, Bjarne W.; Fang, Lei

    2016-01-01

    change rates on the indoor temperatures were performed using the proposed model. When heated surface temperatures and air change rates were from 21.0 to 29.0 degrees C and from 0.5 to 4.0 h-1, the indoor temperatures for calculating the transmission heat loss and ventilation heat loss were between 20...

  11. Orbit losses of strongly ICRF-heated ions

    International Nuclear Information System (INIS)

    Anderson, A.; Dillner, Oe.; Lisak, M.

    1992-01-01

    An approximate analytical investigation is made to assess the importance of orbit losses of strongly ICRF-heated minority ions. Explicit expressions for the fraction of lost minority ions are derived and shown to be in good agreement with numerical simulation results. The results indicate that present day ICRF heating power density levels cannot be raised significantly without causing important particle and energy losses due to unconfined particle orbits. 6 refs., 5 figs

  12. Aging Impairs Whole-Body Heat Loss in Women under Both Dry and Humid Heat Stress.

    Science.gov (United States)

    Notley, Sean R; Poirier, Martin P; Hardcastle, Stephen G; Flouris, Andreas D; Boulay, Pierre; Sigal, Ronald J; Kenny, Glen P

    2017-11-01

    This study was designed to determine whether age-related impairments in whole-body heat loss, which are known to exist in dry heat, also occur in humid heat in women. To evaluate this possibility, 10 young (25 ± 4 yr) and 10 older (51 ± 7 yr) women matched for body surface area (young, 1.69 ± 0.11; older, 1.76 ± 0.14 m, P = 0.21) and peak oxygen consumption (V˙O2peak) (young, 38.6 ± 4.6; older, 34.8 ± 6.6 mL·kg·min, P = 0.15) performed four 15-min bouts of cycling at a fixed metabolic heat production rate (300 W; equivalent to ~45% V˙O2peak), each separated by a 15-min recovery, in dry (35°C, 20% relative humidity) and humid heat (35°C, 60% relative humidity). Total heat loss (evaporative ± dry heat exchange) and metabolic heat production were measured using direct and indirect calorimetry, respectively. Body heat storage was measured as the temporal summation of heat production and loss. Total heat loss was lower in humid conditions compared with dry conditions during all exercise bouts in both groups (all P body heat storage in young and older women, respectively (both P body heat storage was 29% and 16% greater in older women compared with young women in dry and humid conditions, respectively (both P < 0.05). Increasing ambient humidity reduces heat loss capacity in young and older women. However, older women display impaired heat loss relative to young women in both dry and humid heat, and may therefore be at greater risk of heat-related injury during light-to-moderate activity.

  13. Effect of heat loss in a geothermal reservoir

    NARCIS (Netherlands)

    Ganguly, Sayantan; Tan, Lippong; Date, Abhijit; Mohan Kumar, Mandalagiri Subbarayappa

    This paper reports a three-dimensional (3D) numerical study to determine the effect of heat loss on the transient heat transport and temperature distribution in a geothermal reservoir. The operation of a geothermal power plant, which is essentially an injection-production process, involves

  14. Influence of Variable Fluid Properties and Radiative Heat loss on ...

    African Journals Online (AJOL)

    Consequently, comparative analysis is also performed on the wall shear stress and local heat transfer of the present study with the available results.The results show that the inclusion variable viscosity and thermal conductivity, and radiative heat loss mechanism cause significant effects on the fluid flow velocity, temperature ...

  15. Plasma Heating and Losses in Toroidal Multipole Fields

    International Nuclear Information System (INIS)

    Armentrout, C. J.; Barter, J. D.; Breun, R. A.; Cavallo, A. J.; Drake, J. R.; Etzweiler,; Greenwood, J. R.

    1974-01-01

    The heating and loss of plasmas have been studied in three pulsed, toroidal multipole devices: a large levitated octupole, a small supported octupole and a very small supported quadrupole. Plasmas are produced by gun injection and heated by electron and ion cyclotron resonance heating and ohmic heating. Electron cyclotron heating rates have been measured over a wide range of parameters, and the results are in quantitative agreement with stochastic heating theory. Electron cyclotron resonance heating produces ions with energies larger than predicted by theory. With the addition of a toroidal field, ohmic heating gives densities as high as 10 13 cm -3 in the toroidal quadrupole and 10 12 cm -3 in the small octupole. Plasma losses for n=5 x 10 9 cm -3 plasmas are inferred from Langmuir probe and Fabry-Perot interferometer measurements, and measured with special striped collectors on the wall and rings. The loss to a levitated ring is measured using a modulated light beam telemeter. The confinement is better than Bohm but considerably worse than classical. Low frequency convective cells which are fixed in space are observed. These cells around the ring are diminished when a weak toroidal field is added, and loss collectors show a vastly reduced flux to the rings. Analysis of the spatial density profile shows features of B-independent diffusion. The confinement is sensitive to some kinds of dc field errors, but surprisingly insensitive to perturbations of the ac confining field

  16. Ripple losses during ICRF heating in Tore Supra

    International Nuclear Information System (INIS)

    Basiuk, V.; Eriksson, L.-G.; Bergeaud, V.; Chantant, M.; Martin, G.; Nguyen, F.; Reichle, R.; Vallet, J.C.; Delpeche, L.; Surle, F.

    2004-01-01

    The toroidal field coils in Tore Supra are supra-conducting, and their number is restricted to 18. As a result, the ripple is fairly large, about 7% at the plasma boundary. Tore Supra has consequently been equipped with dedicated ripple loss diagnostics, which has allowed ripple loss studies. This paper reports on the measurements made with these diagnostics and provides an analysis of the experimental results, comparing them with theoretical expectations whenever possible. Furthermore, the main heating source accelerating ions in Tore Supra is ion cyclotron resonance range of frequency (ICRF) heating, and the paper provides new information on the ripple losses of ICRF accelerated ions. (author)

  17. Regenerator heat exchanger – calculation of heat recovery efficiency and pressure loss

    DEFF Research Database (Denmark)

    Pomianowski, Michal Zbigniew; Heiselberg, Per Kvols

    Performance of heat exchangers is determined based on two main parameters: efficiency to exchange / recover heat and pressure loss due to friction between fluid and exchanger surfaces. These two parameters are contradicting each other which mean that the higher is efficiency the higher becomes...... pressure loss. The aim of the optimized design of heat exchanger is to reach the highest or the required heat efficiency and at the same time to keep pressure losses as low as possible keeping total exchanger size within acceptable size. In this report is presented analytical calculation method...... to calculate efficiency and pressure loss in the regenerator heat exchanger with a fixed matrix that will be used in the decentralized ventilation unit combined in the roof window. Moreover, this study presents sensitivity study of regenerator heat exchanger performance, taking into account, such parameters as...

  18. Heat loss prediction of a confined premixed jet flame using a conjugate heat transfer approach

    NARCIS (Netherlands)

    Gövert, S.; Mira, D.; Zavala-Ake, M.; Kok, J.B.W.; Vázquez, M.; Houzeaux, G.

    2017-01-01

    The presented work addresses the investigation of the heat loss of a confined turbulent jet flame in a lab-scale combustor using a conjugate-heat transfer approach and large-eddy simulation. The analysis includes the assessment of the principal mechanisms of heat transfer in this combustion chamber:

  19. Quantitative thermography and methods for in-situ determination of heat losses from district heating networks

    Energy Technology Data Exchange (ETDEWEB)

    Boehm, B. [ed.

    1996-11-01

    The course and seminar summarizing application of infrared thermography in district heating systems control gathered Danish specialists with 5 contributions on the subject. Maintenance of the heat distribution pipelines and thermographic inspection of the systems are essential in order to avoid heat losses. (EG)

  20. Modeling heat loss from the udder of a dairy cow.

    Science.gov (United States)

    Gebremedhin, Kifle G; Wu, Binxin

    2016-07-01

    A mechanistic model that predicts sensible and latent heat fluxes from the udder of a dairy cow was developed. The prediction of the model was spot validated against measured data from the literature, and the result agreed within 7% of the measured value for the same ambient temperature. A dairy cow can lose a significant amount of heat (388W/m(2)) from the udder. This suggests that the udder could be considered as a heat sink. The temperature profile through the udder tissue (core to skin) approached the core temperature for an air temperature ≥37°C whereas the profile decreased linearly from the core to skin surface for an air temperature less than 37°C. Sensible heat loss was dominant when ambient air temperature was less than 37.5°C but latent heat loss was greater than sensible heat loss when air temperature was ≥37.5°C. The udder could lose a total (sensible + latent) heat flux of 338W/m(2) at an ambient temperature of 35°C and blood-flow rate of 3.2×10(-3)m(3)/(sm(3) tissue). The results of this study suggests that, in time of heat stress, a dairy cow could be cooled by cooling the udder only (e.g., using an evaporative cooling jacket). Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. Heat loss mechanisms in a measurement of specific heat capacity of graphite

    International Nuclear Information System (INIS)

    Shipley, D.R.; Duane, S.

    1996-01-01

    Absorbed dose to graphite in electron beams with nominal energies in the range 3-20 MeV is determined by measuring the temperature rise in the core of a primary standard graphite calorimeter. This temperature rise is related to absorbed dose by a separate measurement of the specific heat capacity of the graphite core. There is, however, a small but significant amount of heat loss from the sample in the determination of specific heat capacity and corrections for these losses are required. This report discusses the sources of heat loss in the measurements and, where possible, provides estimates for the magnitude of these losses. For those mechanisms which are significant, a more realistic model of the measurement system is analysed and corrections for the losses are provided. (UK)

  2. Steady-state heat losses in pipes for low-energy district heating

    DEFF Research Database (Denmark)

    Dalla Rosa, Alessandro; Li, Hongwei; Svendsen, Svend

    2010-01-01

    The synergy between highly energy efficient buildings and low-energy district heating (DH) systems is a promising concept for the optimal integration of energy saving policies and energy supply systems based on renewable energy (RE). Distribution heat losses represent a key factor in the design o...

  3. Heat stress causes substantial labour productivity loss in Australia

    Science.gov (United States)

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

    2015-07-01

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

  4. MATHEMATICAL MODELLING OF OPERATION HEAT NETWORKS IN VIEW OF HEAT LOSS

    Directory of Open Access Journals (Sweden)

    ZBARAZ L. I.

    2016-08-01

    Full Text Available Goal. In recent years, due to a significant rise in price of energy, the reduction of direct costs for heating becomes a priority. In the utilities especially important to optimization of energy heating system equipment. During transport of thermal energy in the distribution networks thermal losses occur along the length of the hydraulic pipes and the coolant pumping losses. These loss-dependence of the particular distribution network. Changing temperature and the hydraulic regime at the source necessary to achieve the minimum cost of transport for today acting tariffs for energy. Scientific novelty. The studies received law changes head to the source at the qualitative and quantitative methods of regulation. Results. A mathematical model of an extensive network of decentralized heat source heating, which are analyzed using different methods of regulating and found the best.

  5. Effect of pipe insulation losses on a loss-of-heat sink accident for an LMR

    International Nuclear Information System (INIS)

    Horak, W.C.; Guppy, J.G.; Wood, P.M.

    1985-01-01

    The efficacy of pipe radiation losses as a heat sink during LOHS in a loop-type LMR plant is investigated. The Super System Code (SSC), which was modified to include pipe radiation losses, was used to simulate such an LOHS in an LMR plant. In order to enhance these losses, the pipes were assumed to be insulated by rock wool, a material whose thermal conductivity increases with increasing temperature. A transient was simulated for a total of eight days, during which the coolant temperatures peaked well below saturation conditions and then declined steadily. The coolant flow rate in the loop remained positive throughout the transient

  6. A comparison of different methods for in-situ determination of heat losses form district heating pipes

    Energy Technology Data Exchange (ETDEWEB)

    Boehm, Benny [Technical Univ. of Denmark, Dept. of Energy Engineering (Denmark)

    1996-11-01

    A comparison of different methods for in-situ determination of heat losses has been carried out on a 273 mm transmission line in Copenhagen. Instrumentation includes temperature sensors, heat flux meters and an infrared camera. The methods differ with regard to time consumption and costs of applying the specific method, demand on accuracy of temperature measurements, sensitivity to computational parameters, e.g. the thermal conductivity of the soil, response to transients in water temperature and the ground, and steady state assumptions in the model used in the interpretation of the measurements. Several of the applied methods work well. (au)

  7. Tissue physiology and the response to heat

    DEFF Research Database (Denmark)

    Horsman, Michael Robert

    2006-01-01

    physiological effects should occur in normal tissues, such combination therapies must be carefully applied. Heating tumours to higher temperatures typically causes a transient increase in perfusion during heating, followed by vascular collapse which if sufficient will increase tumour necrosis. The speed...... and degree of vascular collapse is dependent on heating time, temperature and tumour model used. Such vascular collapse generally occurs at temperatures that cause a substantial blood flow increase in certain normal tissues, thus preferential anti-tumour effects can be achieved. The tumour vascular supply...... can also be exploited to improve the response to heat. Decreasing blood flow, using transient physiological modifiers or longer acting vascular disrupting agents prior to the initiation of heating, can both increase the accumulation of physical heat in the tumour, as well as increase heat sensitivity...

  8. Combined Influence of Strain and Heat Loss on Turbulent Premixed Flame Stabilization

    KAUST Repository

    Tay-Wo-Chong, Luis; Zellhuber, Mathieu; Komarek, Thomas; Im, Hong G.; Polifke, Wolfgang

    2015-01-01

    relation in terms of Markstein number, Karlovitz Number and a non-dimensional heat loss parameter was proposed for the combined influence of strain and heat losses on the consumption speed. Combining this empirical relation with a presumed probability

  9. Condensing heat transfer following a loss-of-coolant accident

    International Nuclear Information System (INIS)

    Krotiuk, W.J.; Rubin, M.B.

    1978-01-01

    A new method for calculating the steam mass condensation energy removal rates on cold surfaces in contact with an air-steam mixture has been developed. This method is based on the principles of mass diffusion of steam from an area of high concentration to the condensing surface, which is an area of low steam concentration. This new method of calculating mass condensation has been programmed into the CONTEMPT-LT Mod 26 computer code, which calculates the pressure and temperature transients inside a light water reactor containment following a loss-of-coolant accident. The condensing heat transfer coefficient predicted by the mass diffusion method is compared to existing semi-empirical correlations and to the experimental results of the Carolinas Virginia Tube Reactor Containment natural decay test. Closer agreement with test results is shown in the calculation of containment pressure, temperature, and heat sink surface temperature using the mass diffusion condensation method than when using any existing semi-empirical correlation

  10. Chaos of radiative heat-loss-induced flame front instability.

    Science.gov (United States)

    Kinugawa, Hikaru; Ueda, Kazuhiro; Gotoda, Hiroshi

    2016-03-01

    We are intensively studying the chaos via the period-doubling bifurcation cascade in radiative heat-loss-induced flame front instability by analytical methods based on dynamical systems theory and complex networks. Significant changes in flame front dynamics in the chaotic region, which cannot be seen in the bifurcation diagrams, were successfully extracted from recurrence quantification analysis and nonlinear forecasting and from the network entropy. The temporal dynamics of the fuel concentration in the well-developed chaotic region is much more complicated than that of the flame front temperature. It exhibits self-affinity as a result of the scale-free structure in the constructed visibility graph.

  11. Heat Transmission Coefficient Measurements in Buildings Utilizing a Heat Loss Measuring Device

    DEFF Research Database (Denmark)

    Sørensen, Lars Schiøtt

    2013-01-01

    Global energy efficiency can be obtained in two ordinary ways. One way is to improve the energy production and supply side, and the other way is, in general, to reduce the consumption of energy in society. This paper has focus on the latter and especially the consumption of energy for heating...... and cooling our houses. There is a huge energy-saving potential in this area for reducing both the global climate problems as well as economy challenges. Heating of buildings in Denmark accounts for approximately 40% of the entire national energy consumption. For this reason, a reduction of heat losses from...... building envelopes are of great importance in order to reach the Bologna CO2 emission reduction targets. Upgrading of the energy performance of buildings is a topic of huge global interest these years. Not only heating in the temperate and arctic regions are important, but also air conditioning...

  12. 7 CFR 760.812 - Production losses; participant responsibility.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 7 2010-01-01 2010-01-01 false Production losses; participant responsibility. 760.812....812 Production losses; participant responsibility. (a) Where available and determined accurate by FSA, RMA loss records will be used for insured crops. (b) If RMA loss records are not available, or if the...

  13. Study of high energy ion loss during hydrogen minority heating in TFTR

    International Nuclear Information System (INIS)

    Park, J.; Zweben, S.J.

    1994-03-01

    High energy ion loss during hydrogen minority ICRF heating is measured and compared with the loss of the D-D fusion products. During H minority heating a relatively large loss of high energy ions is observed at 45 degrees below the outer midplane, with or without simultaneous NBI heating. This increase is most likely due to a loss of the minority tail protons, a possible model for this process is described

  14. Thermal stratification in a hot water tank established by heat loss from the tank

    DEFF Research Database (Denmark)

    Fan, Jianhua; Furbo, Simon

    2012-01-01

    This paper presents numerical investigations of thermal stratification in a vertical cylindrical hot water tank established by standby heat loss from the tank. The transient fluid flow and heat transfer in the tank during cooling caused by standby heat loss are calculated by means of validated...... computational fluid dynamics (CFD) models. The measured heat loss coefficient for the different parts of the tank is used as input to the CFD model. Parametric studies are carried out using the validated models to investigate the influence on thermal stratification of the tank by the downward flow...... the heat loss from the tank sides will be distributed at different levels of the tank at different thermal conditions. The results show that 20–55% of the side heat loss drops to layers below in the part of the tank without the presence of thermal stratification. A heat loss removal factor is introduced...

  15. Geospatial Analysis of the Building Heat Demand and Distribution Losses in a District Heating Network

    Directory of Open Access Journals (Sweden)

    Tobias Törnros

    2016-11-01

    Full Text Available The district heating (DH demand of various systems has been simulated in several studies. Most studies focus on the temporal aspects rather than the spatial component. In this study, the DH demand for a medium-sized DH network in a city in southern Germany is simulated and analyzed in a spatially explicit approach. Initially, buildings are geo-located and attributes obtained from various sources including building type, ground area, and number of stories are merged. Thereafter, the annual primary energy demand for heating and domestic hot water is calculated for individual buildings. Subsequently, the energy demand is aggregated on the segment level of an existing DH network and the water flow is routed through the system. The simulation results show that the distribution losses are overall the highest at the end segments (given in percentage terms. However, centrally located pipes with a low throughflow are also simulated to have high losses. The spatial analyses are not only useful when addressing the current demand. Based on a scenario taking into account the refurbishment of buildings and a decentralization of energy production, the future demand was also addressed. Due to lower demand, the distribution losses given in percentage increase under such conditions.

  16. Combined heat transfer and kinetic models to predict cooking loss during heat treatment of beef meat.

    Science.gov (United States)

    Kondjoyan, Alain; Oillic, Samuel; Portanguen, Stéphane; Gros, Jean-Bernard

    2013-10-01

    A heat transfer model was used to simulate the temperature in 3 dimensions inside the meat. This model was combined with a first-order kinetic models to predict cooking losses. Identification of the parameters of the kinetic models and first validations were performed in a water bath. Afterwards, the performance of the combined model was determined in a fan-assisted oven under different air/steam conditions. Accurate knowledge of the heat transfer coefficient values and consideration of the retraction of the meat pieces are needed for the prediction of meat temperature. This is important since the temperature at the center of the product is often used to determine the cooking time. The combined model was also able to predict cooking losses from meat pieces of different sizes and subjected to different air/steam conditions. It was found that under the studied conditions, most of the water loss comes from the juice expelled by protein denaturation and contraction and not from evaporation. Copyright © 2013 Elsevier Ltd. All rights reserved.

  17. The radiative heating response to climate change

    Science.gov (United States)

    Maycock, Amanda

    2016-04-01

    The structure and magnitude of radiative heating rates in the atmosphere can change markedly in response to climate forcings; diagnosing the causes of these changes can aid in understanding parts of the large-scale circulation response to climate change. This study separates the relative drivers of projected changes in longwave and shortwave radiative heating rates over the 21st century into contributions from radiatively active gases, such as carbon dioxide, ozone and water vapour, and from changes in atmospheric and surface temperatures. Results are shown using novel radiative diagnostics applied to timeslice experiments from the UM-UKCA chemistry-climate model; these online estimates are compared to offline radiative transfer calculations. Line-by-line calculations showing spectrally-resolved changes in heating rates due to different gases will also be presented.

  18. Fitness-related differences in the rate of whole-body total heat loss in exercising young healthy women are heat-load dependent.

    Science.gov (United States)

    Lamarche, Dallon T; Notley, Sean R; Poirier, Martin P; Kenny, Glen P

    2018-03-01

    What is the central question of this study? Aerobic fitness modulates heat loss, albeit the heat load at which fitness-related differences occur in young healthy women remains unclear. What is the main finding and its importance? We demonstrate using direct calorimetry that fitness modulates heat loss in a heat-load dependent manner, with differences occurring between young women of low and high fitness and matched physical characteristics when the metabolic heat load is at least 400 W in hot, dry conditions. Although fitness has been known for some time to modulate heat loss, our findings define the metabolic heat load at which fitness-related differences occur. Aerobic fitness has recently been shown to alter heat loss capacity in a heat-load dependent manner in young men. However, given that sex-related differences in heat loss capacity exist, it is unclear whether this response is consistent in women. We therefore assessed whole-body total heat loss in young (21 ± 3 years old) healthy women matched for physical characteristics, but with low (low-fit; 35.8 ± 4.5 ml O 2  kg -1  min -1 ) or high aerobic fitness (high-fit; 53.1 ± 5.1 ml O 2  kg -1  min -1 ; both n = 8; indexed by peak oxygen consumption), during three 30 min bouts of cycling performed at increasing rates of metabolic heat production of 250 (Ex1), 325 (Ex2) and 400 W (Ex3), each separated by a 15 min recovery, in hot, dry conditions (40°C, 11% relative humidity). Whole-body total heat loss (evaporative ± dry heat exchange) and metabolic heat production were measured using direct and indirect calorimetry, respectively. Body heat content was measured as the temporal summation of heat production and loss. Total heat loss did not differ during Ex1 (low-fit, 215 ± 16 W; high-fit, 231 ± 20 W; P > 0.05) and Ex2 (low-fit, 278 ± 15 W; high-fit, 301 ± 20 W; P > 0.05), but was lower in the low-fit (316 ± 21 W) compared with the high-fit women (359 ± 32

  19. Loss of Coolant Accidents (LOCA): Study of CAREM Reactor Response

    International Nuclear Information System (INIS)

    Gonzalez, Jose; Gimenez, Marcelo

    2000-01-01

    We analyzed the neutronic and thermohydraulic response of CAREM25 reactor and the safety systems involved in a Loss Of Coolant Accident (LOCA).This parametric analysis considers several break diameters (1/2inch, 3/4inch, 1inch, 1.1/2inch and 2inches) in the vapor zone of the Reactor Pressure Vessel.For each accidental sequence, the successful operation of the following safety systems is modeled: Second Safety System (SSS), Residual Heat Removal System (RHRS) and Safety Injection System (SIS). Availability of only one module is postulated for each system.On the other hand, the unsuccessful operation of all safety systems is postulated for each accidental sequence.In both cases the First Shutdown System (FSS) actuates, and the loss of Steam Generator secondary flow and Chemical and Control of Volume System (CCVS) unavailability are postulated.Maximum loss of coolant flow, reactor power and time for safety systems operation are analyzed, as well as its set point parameters.We verified that safety systems are dimensioned to satisfy the 48 hours cooling criteria

  20. Experimental and numerical analysis of convective heat losses from spherical cavity receiver of solar concentrator

    Directory of Open Access Journals (Sweden)

    Shewale Vinod C.

    2017-01-01

    Full Text Available Spherical cavity receiver of solar concentrator is made up of Cu tubing material having cavity diameter 385 mm to analyze the different heat losses such as conduction, convection and radiation. As the convection loss plays major role in heat loss analysis of cavity receiver, the experimental analysis is carried out to study convective heat loss for the temperature range of 55-75°C at 0°, 15°, 30°, 45°, 60°, and 90° inclination angle of downward facing cavity receiver. The numerical analysis is carried out to study convective heat loss for the low temperature range (55-75°C as well as high temperature range (150-300 °C for no wind condition only. The experimental set-up mainly consists of spherical cavity receiver which is insulated with glass wool insulation to reduce the heat losses from outside surface. The numerical analysis is carried out by using CFD software and the results are compared with the experimental results and found good agreement. The result shows that the convective loss increases with decrease in cavity inclination angle and decreases with decrease in mean cavity receiver temperature. The maximum losses are obtained at 0° inclination angle and the minimum losses are obtained at 90° inclination angle of cavity due to increase in stagnation zone in to the cavity from 0° to 90° inclination. The Nusselt number correlation is developed for the low temperature range 55-75°C based on the experimental data. The analysis is also carried out to study the effect of wind speed and wind direction on convective heat losses. The convective heat losses are studied for two wind speeds (3 m/s and 5 m/s and four wind directions [α is 0° (Side-on wind, 30°, 60°, and 90° (head-on wind]. It is found that the convective heat losses for both wind speed are higher than the losses obtained by no wind test. The highest heat losses are found for wind direction α is 60° with respect to receiver stand and lowest heat losses are found

  1. Assessment of heat loss for RSG-GAS primary cooling system

    International Nuclear Information System (INIS)

    Dibyo, S.

    1998-01-01

    Heat Loss is part term of energy balance equation of system, therefore heat loss very important thing in the thermal dynamic analysis. Heat energy loosed from the surface pipe to the air in the room was calculated. Heat energy pass through by conduction, convection and radiation. The convection process are caused by moving of air density, i.e up flow of the hot air return to be down flow. The heat transfer phenomenon could be determined by empirical correlation of Heilman. The primary cooling system is consisted to the 3 zone : 1). Zone of (safety valves-heat exchanger), 2). Zone of heat exchanger surfaces, 3). Zone of heat exchanger-reactor pool. By using input data of air temperature are about 25 o C, temperature of primary coolant about 45 o C, The heat Loss along the pipes to the air are 23.9 k watt or 0.1%

  2. System transient response to loss of off-site power

    International Nuclear Information System (INIS)

    Sozer, A.

    1990-01-01

    A simultaneous trip of the reactor, main circulation pumps, secondary coolant pumps, and pressurizer pump due to loss of off-site power at the High Flux Isotope Reactor (HFIR) located at the Oak Ridge National Laboratory (ORNL) has been analyzed to estimate available safety margin. A computer model based on the Modular Modeling System code has been used to calculate the transient response of the system. The reactor depressurizes from 482.7 psia down to about 23 psia in about 50 seconds and remains stable thereafter. Available safety margin has been estimated in terms of the incipient boiling heat flux ratio. It is a conservative estimate due to assumed less than available primary and secondary flows and higher than normal depressurization rate. The ratio indicates no incipient boiling conditions at the hot spot. No potential damage to the fuel is likely to occur during this transient. 2 refs., 6 figs

  3. Evaluation of external heat loss from a small-scale expander used in organic Rankine cycle

    International Nuclear Information System (INIS)

    Li Jing; Pei Gang; Li Yunzhu; Ji Jie

    2011-01-01

    With the scaling down of the Organic Rankine Cycle (ORC), the engine shaft power is not only determined by the enthalpy drop in the expansion process but also the external heat loss from the expander. Theoretical and experimental support in evaluating small-scale expander heat loss is rare. This paper presents a quantitative study on the convection, radiation, and conduction heat transfer from a kW-scale expander. A mathematical model is built and validated. The results show that the external radiative or convective heat loss coefficient was about 3.2 or 7.0 W/K.m 2 when the ORC operated around 100 o C. Radiative and convective heat loss coefficients increased as the expander operation temperature increased. Conductive heat loss due to the connection between the expander and the support accounted for a large proportion of the total heat loss. The fitting relationships between heat loss and mean temperature difference were established. It is suggested that low conductivity material be embodied in the support of expander. Mattress insulation for compact expander could be eliminated when the operation temperature is around 100 o C. - Highlights: → A close examination of external heat loss from a small expander is presented. → Theoretical analysis and experimental test were conducted. → The established formulas can be applied to other small ORC expanders. → The results are useful in further research of small-scale ORC.

  4. Combined Influence of Strain and Heat Loss on Turbulent Premixed Flame Stabilization

    KAUST Repository

    Tay-Wo-Chong, Luis

    2015-11-16

    The present paper argues that the prediction of turbulent premixed flames under non-adiabatic conditions can be improved by considering the combined effects of strain and heat loss on reaction rates. The effect of strain in the presence of heat loss on the consumption speed of laminar premixed flames was quantified by calculations of asymmetric counterflow configurations (“fresh-to-burnt”) with detailed chemistry. Heat losses were introduced by setting the temperature of the incoming stream of products on the “burnt” side to values below those corresponding to adiabatic conditions. The consumption speed decreased in a roughly exponential manner with increasing strain rate, and this tendency became more pronounced in the presence of heat losses. An empirical relation in terms of Markstein number, Karlovitz Number and a non-dimensional heat loss parameter was proposed for the combined influence of strain and heat losses on the consumption speed. Combining this empirical relation with a presumed probability density function for strain in turbulent flows, an attenuation factor that accounts for the effect of strain and heat loss on the reaction rate in turbulent flows was deduced and implemented into a turbulent combustion model. URANS simulations of a premixed swirl burner were carried out and validated against flow field and OH chemiluminescence measurements. Introducing the effects of strain and heat loss into the combustion model, the flame topology observed experimentally was correctly reproduced, with good agreement between experiment and simulation for flow field and flame length.

  5. Radiant heat loss, an unexploited path for heat stress reduction in shaded cattle.

    Science.gov (United States)

    Berman, A; Horovitz, T

    2012-06-01

    Reducing thermal radiation on shaded animals reduces heat stress independently of other means of stress relief. Radiant heat exchange was estimated as a function of climate, shade structure, and animal density. Body surface portion exposed to radiant sources in shaded environments was determined by geometrical relations to determine angles of view of radiation sources (roof underside, sky, sun-exposed ground, shaded ground) on the animal's surface. The relative representation of environment radiation sources on the body surface was determined. Animal thermal radiation balance was derived from radiant heat gained from radiation sources (including surrounding animals) and that lost from the animal surface. The animal environment was assumed to have different shade dimensions and temperatures. These were summed to the radiant heat balance of the cow. The data formed served to estimate the effect of changes in intensity of radiation sources, roof and shaded surface dimensions, and animal density on radiant heat balance (Rbal) of cattle. Roof height effect was expressed by effect of roof temperature on Rbal. Roof underside temperature (35 to 75°C) effect on Rbal was reduced by roof height. If roof height were 4m, an increase in its underside temperature from 35 to 75°C would increase mean Rbal from -63 to -2 W·m⁻², whereas if roof height were 10 m, Rbal would only increase from -99 to -88 W·m⁻². A hot ground temperature increase from 35 to 65°C reduced mean Rbal heat loss from -45 to 3 W·m⁻². Increasing the surface of the shaded area had only a minor effect on Rbal and on the effect of hot ground on Rbal. Increasing shade roof height reduced the effect of roof temperature on Rbal to minor levels when height was > 8m. Increasing the roof height from 4 to 10 m decreased Rbal from -32 to -94 W·m⁻². Increasing indirect radiation from 100 to 500 W·m⁻² was associated with an increase in Rbal from -135 to +23 W·m⁻². Their combined effects were lower

  6. Test bench HEATREC for heat loss measurement on solar receiver tubes

    Science.gov (United States)

    Márquez, José M.; López-Martín, Rafael; Valenzuela, Loreto; Zarza, Eduardo

    2016-05-01

    In Solar Thermal Electricity (STE) plants the thermal energy of solar radiation is absorbed by solar receiver tubes (HCEs) and it is transferred to a heat transfer fluid. Therefore, heat losses of receiver tubes have a direct influence on STE plants efficiency. A new test bench called HEATREC has been developed by Plataforma Solar de Almería (PSA) in order to determinate the heat losses of receiver tubes under laboratory conditions. The innovation of this test bench consists in the possibility to determine heat losses under controlled vacuum.

  7. Buoyancy driven flow in a hot water tank due to standby heat loss

    DEFF Research Database (Denmark)

    Fan, Jianhua; Furbo, Simon

    2012-01-01

    Results of experimental and numerical investigations of thermal behavior in a vertical cylindrical hot water tank due to standby heat loss of the tank are presented. The effect of standby heat loss on temperature distribution in the tank is investigated experimentally on a slim 150l tank...... show that the CFD model predicts satisfactorily water temperatures at different levels of the tank during cooling by standby heat loss. It is elucidated how the downward buoyancy driven flow along the tank wall is established by the heat loss from the tank sides and how the natural convection flow...... with a height to diameter ratio of 5. A tank with uniform temperatures and with thermal stratification is studied. A detailed computational fluid dynamics (CFD) model of the tank is developed to calculate the natural convection flow in the tank. The distribution of the heat loss coefficient for the different...

  8. Method for optimal design of pipes for low-energy district heating, with focus on heat losses

    DEFF Research Database (Denmark)

    Dalla Rosa, Alessandro; Li, Hongwei; Svendsen, Svend

    2011-01-01

    The synergy between highly energy-efficient buildings and low-energy district heating (DH) systems is a promising concept for the optimal integration of energy-saving policies and energy supply systems based on renewable energy (RE). Network transmission and distribution heat loss is one of the k...

  9. Reduction of heat losses from greenhouses by means of internal blinds with low thermal emissivity

    NARCIS (Netherlands)

    Meijer, J.

    1980-01-01

    Heat losses in greenhouses may be substantially reduced by the use of heat reflecting blinds. Quantitative results are obtained solving a mathematical heat flow model by numerical methods. Special attention has been given to the emissivity and transmittance of the screen and the ventilation through

  10. Predicting TDN losses from heat damaged hays and haylages with NIR

    Science.gov (United States)

    During the storage of hay or haylage, heating damage may occur and lead to losses of available protein and digestible nutrients. Recent research indicates that losses of TDN may be more significant economically than losses of available protein. Our objectives for this study were to establish a near-...

  11. Radiation loss driven instabilities in laser heated plasmas

    International Nuclear Information System (INIS)

    Evans, R.G.

    1985-01-01

    Any plasma in which a significant part of the power balance is due to optically thin radiative losses may be subject to a radiation cooling instability. A simple analytical model gives the dispersion relation for the instability and inclusion of a realistic radiation loss term in a two dimensional hydrodynamic simulation shows that ''jet'' like features form in moderate to high Z plasmas

  12. Thermoregulatory responses to acute heat loads in rats following spontaneous running.

    Science.gov (United States)

    Sugimoto, N; Shido, O; Sakurada, S; Nagasaka, T

    1999-02-01

    Earlier studies showed that spontaneous exercise training in rodents shifted their core temperature and thermoeffector thresholds to high levels. The present study investigated heat loss and heat production responses to acute heat loads of exercise-trained rats. The exercise-trained rats were allowed to run in a running wheel freely for 6 months, while the sedentary controls were denied access to the wheel during the same period. Then, they were loosely restrained and put in a direct calorimeter. After thermal equilibrium had been attained, they were warmed for 30 min with an intraperitoneal electric heater (internal heating). At least 2 h later, the rats were externally warmed for 90 min by raising the ambient temperature from 24 to 38C (external warming). Hypothalamic temperature (Thy), evaporative and nonevaporative heat loss (R+C+K) and heat production were measured. Internal and external heating significantly increased Thy. During internal heating, the magnitude of the increase in Thy was significantly smaller and the amount of increase in (R+C+K) was significantly greater in the exercise-trained rats than in the controls. The slope showing the relationship between Thy and (R+C+K) in the trained rats was significantly steeper than that in the controls. During external warming, the magnitude of increase in Thy of the exercise-trained rats was significantly greater than that of the controls. The slope showing the relationship between Thy and (R+C+K) in the trained rats was not different from that in the controls. Changes in evaporative heat loss and heat production during the two types of heat load did not differ between the two groups. The results suggest that, in rats, exercise training with voluntary running improves heat tolerance through enhancing nonevaporative heat loss response. However, this may be the case only when the rats are subjected to a direct internal heat load.

  13. Recouping the thermal-to-electric conversion loss by the use of waste heat

    International Nuclear Information System (INIS)

    Bradley, W.J.

    1976-01-01

    This paper looks at ways to recoup the thermal-to-electric conversion loss of our thermal power generating stations. These stations now produce twice as much low-grade waste heat as they do electricity. We can improve the situation in two ways: by improving the station efficiency, and by utilizing the low-grade heat beneficially. The following options are examined: N 2 O 4 turbines condensing at 10 deg C; power from moderator waste heat; 50 MW heat pump for district heating; industrial parks with integrated waste heat upgrading station. (author)

  14. Plate heat exchanger - inertia flywheel performance in loss of flow transient

    International Nuclear Information System (INIS)

    Abou-El-Maaty, Talal; Abd-El-Hady, Amr

    2009-01-01

    One of the most versatile types of heat exchangers used is the plate heat exchanger. It has principal advantages over other heat exchangers in that plates can be added and/or removed easily in order to change the area available for heat transfer and therefore its overall performance. The cooling systems of Egypt's second research reactor (ETRR 2) use this type of heat exchanger for cooling purposes in its primary core cooling and pool cooling systems. In addition to the change in the number of heat exchanger cooling channels, the effect of changing the amount of mass flow rate on the heat exchanger performance is an important issues in this study. The inertia flywheel mounted on the primary core cooling system pump with the plate heat exchanger plays an important role in the case of loss of flow transients. The PARET code is used to simulate the effect of loss of flow transients on the reactor core. Hence, the core outlet temperature with the pump-flywheel flow coast down is fed into the plate heat exchanger model developed to estimate the total energy transferred to the cooling tower, the primary side heat exchanger temperature variation, the transmitted heat exchanger power, and the heat exchanger effectiveness. In addition, the pressure drop in both, the primary side and secondary side of the plate heat exchanger is calculated in all simulated transients because their values have limits beyond which the heat exchanger is useless. (orig.)

  15. Heat loss may explain bill size differences between birds occupying different habitats.

    Directory of Open Access Journals (Sweden)

    Russell Greenberg

    Full Text Available Research on variation in bill morphology has focused on the role of diet. Bills have other functions, however, including a role in heat and water balance. The role of the bill in heat loss may be particularly important in birds where water is limiting. Song sparrows localized in coastal dunes and salt marsh edge (Melospiza melodia atlantica are similar in size to, but have bills with a 17% greater surface area than, those that live in mesic habitats (M. m. melodia, a pattern shared with other coastal sparrows. We tested the hypotheses that sparrows can use their bills to dissipate "dry" heat, and that heat loss from the bill is higher in M. m. atlantica than M. m. melodia, which would indicate a role of heat loss and water conservation in selection for bill size.Bill, tarsus, and body surface temperatures were measured using thermal imaging of sparrows exposed to temperatures from 15-37°C and combined with surface area and physical modeling to estimate the contribution of each body part to total heat loss. Song sparrow bills averaged 5-10°C hotter than ambient. The bill of M. m atlantica dissipated up to 33% more heat and 38% greater proportion of total heat than that of M. m. melodia. This could potentially reduce water loss requirements by approximately 7.7%.This >30% higher heat loss in the bill of M. m. atlantica is independent of evaporative water loss and thus could play an important role in the water balance of sparrows occupying the hot and exposed dune/salt marsh environments during the summer. Heat loss capacity and water conservation could play an important role in the selection for bill size differences between bird populations and should be considered along with trophic adaptations when studying variation in bill size.

  16. HEAT LOSS FROM HOT WATER SUPPLY LINE IN A RESIDENTIAL BUILDING

    OpenAIRE

    近藤, 修平; 鉾井, 修一

    2011-01-01

    In order to the evaluate heat loss from hot water supply lines in a residential building, hot water demand in a house in Chiba prefecture was measured and analyzed. The following results were obtained. 1. The heat loss of the hot water supply line was about 132kJ for the shower and 110kJ for the bathtub in winter. Since the temperature difference between the inlet and outlet of the hot water supply line is small, the measured heat loss from the hot water supply line sometimes becomes negative...

  17. Oceans and continents: Similarities and differences in the mechanisms of heat loss

    International Nuclear Information System (INIS)

    Sclater, J.G.; Parsons, B.; Jaupart, C.

    1981-01-01

    The principal objective of this paper is to present a simple and self-consistent review of the basic physical processes controlling heat loss from the earth. To accomplish this objective, we give a short summary of the oceanic and continental data and compare and contrast the respective mechanisms of heat loss . In the oceans we concentrate on the effect of hydrothermal circulation, and on the continents we consider in some detail a model relating surface heat flow to varying depth scales for the distribution of potassium, thorium, and uranium. From this comparison we conclude that the range in possible geotherms at depths below 100 to 150 km under continents and oceans overlaps and the thermal structure beneath an old stable continent is indistinguishable from that beneath an ocean were it at equilibrium. Oceans and continents are part of the same thermal system. Both have an upper rigid mechanical layer where heat loss is by conduction and a lower thermal boundary layer where convection is dominant. The simple conductive definition of the plate thickness is an oversimplification. The observed distribution of area versus age in the ocean allows us to investigate the dominant mechanism of heat loss which is plate creation. This distribution and an understanding of the heat flow through oceans and continents can be used to calculate the heat loss of the earth. This heat loss is 10 13 cal/s (4.2 x 10 13 W) of which more than 60% results from the creation of oceanic plate. The relation between area and age of the oceans is coupled to the ridge and subducting slab forces that contribute to the driving mechanism for plate motions. These forces are self-regulating and maintain the rate of plate generation required to achieve a balance between heat loss and heat generation

  18. Heat loss and fluid leakage tests of the ROSA-III facility

    International Nuclear Information System (INIS)

    Suzuki, Mitsuhiro; Tasaka, Kanji; Shiba, Masayoshi

    1981-12-01

    The report presents characteristic test results about the steady state heat loss, one of the inherent characteristics of the ROSA-III test facility. The steady state heat loss tests were conducted at five different temperature conditions between 111 0 C and 290 0 C . Net heat loss rates were obtained by estimating the electric power supplied to the core, heat input from the recirculation pumps and steam leakage rate. The heat loss characteristics have important contribution to analyses of the ROSA-III small break tests. A following simple relation was obtained between the net heat loss rate Q*sub(HL) (kJ/s) (*: radical) of the ROSA-III facility and the temperature difference ΔT ( 0 C) between the fluid temperature of the system and the room temperature, Q*sub(HL) = 0.56 x ΔT. (*: radical) And the steam leak flow at normal operating condition of the ROSA-III test, (P = 7.2 MPa) was obtained as 8.9 x 10 -3 kg/s and corresponding steam leakage energy as 10.5 kJ/s. The heat input from the recirculation pumps was indirectly estimated under a constant speed by assuming the heat input was equal to the brake horce power of the pumps. (author)

  19. MeV ion loss during 3He minority heating in TFTR

    International Nuclear Information System (INIS)

    Zweben, S.J.; Hammett, G.; Boivin, R.; Phillips, C.; Wilson, R.

    1992-01-01

    The loss of MeV ions during 3 He ICRH minority heating experiments has been measured using scintillator detectors near the wall of TFTR. The observed MeV ion losses to the bottom (90 degrees poloidal) detector are generally consistent with the expected first-orbit loss of D- 3 He alpha particle fusion products, with an inferred global reaction rate up to ∼10 16 reactions/sec. A qualitatively similar but unexpectedly large loss occurs 45 degrees poloidally below the outer midplane. This additional loss might be due to ICRH tail ions or to ICRH wave-induced loss of previously confined fusion products

  20. Heat loss during carbon dioxide insufflation: comparison of a nebulization based humidification device with a humidification and heating system.

    Science.gov (United States)

    Noll, Eric; Schaeffer, Roland; Joshi, Girish; Diemunsch, Sophie; Koessler, Stefanie; Diemunsch, Pierre

    2012-12-01

    This study compared the heat loss observed with the use of MR860 AEA Humidifier™ system (Fisher & Paykel Healthcare, New Zealand), which humidifies and heats the insufflated CO(2), and the use of the AeronebPro™ device (Aerogen, Ireland), which humidifies but does not heat the insufflated CO(2). With institutional approval, 16 experiments were conducted in 4 pigs. Each animal, acting as its own control, was studied at 8-day intervals in randomized sequence with the following four conditions: (1) control (C) no pneumoperitoneum; (2) standard (S) insufflation with nonhumidified, nonheated CO(2); (3) Aeroneb™ (A): insufflation with humidified, nonheated CO(2); and (4) MR860 AEA humidifier™ (MR): insufflation with humidified and heated CO(2). The measured heat loss after 720L CO(2) insufflation during the 4 h was 1.03 ± 0.75 °C (mean ± SEM) in group C; 3.63 ± 0.31 °C in group S; 3.03 ± 0.39 °C in group A; and 1.98 ± 0.09 °C in group MR. The ANOVA showed a significant difference with time (p = 0.0001) and with the insufflation technique (p = 0.024). Heat loss in group C was less than in group S after 60 min (p = 0.03), less than in group A after 70 min (p = 0.03), and less than in group MR after 150 min (p = 0.03). The heat loss in group MR was less than in group S after 50 min (p = 0.04) and less than in group A after 70 min (p = 0.02). After 160 min, the heat loss in group S was greater than in group A (p = 0.03). As far as heat loss is concerned, for laparoscopic procedures of less than 60 min, there is no benefit of using any humidification with or without heating. However, for procedures greater than 60 min, use of heating along with humidification, is superior.

  1. ESBWR long term containment response to loss of coolant accidents

    International Nuclear Information System (INIS)

    Alamgir, M. D.; Marquino, W.; Diaz-Quiroz, J.; Tucker, L.

    2010-01-01

    ESBWR is a 4500 MWt generation III+ natural circulation reactor with an array of robust passive safety systems to keep the reactor safe during postulated transients and accidents. With the submittal of the latest revision of the Design Control Document (DCD) to US Nuclear Regulatory Commission, ESBWR is nearing the completion of the US certification process. This paper focuses on the bounding licensing analysis of the long-term (30-day) response of the ESBWR containment to limiting Loss of Coolant Accident (LOCA) performed with the TRACG code. It is shown that using only passive systems available during the first 72 hours after the limiting Main Steam Line Break LOCA, the predicted peak containment pressure in the ESBWR containment remain well below the design limits with good margin. After 72 hours of LOCA initiation, PCCS Vent Fans (non-safety system) become available that remove non-condensable gases from, and further enhance the effectiveness of, PCCS heat exchangers to reduce the containment pressure and temperature to values substantially below the design limits. During the post- 72 hour period, the beneficial effects of the Vent Fan operation, combined with the available operator action to refill of PCCS pools, continue to maintain the containment pressure to about 30% below the design limit at 30 days after a limiting ESBWR LOCA. (authors)

  2. Wind effects on convective heat loss from a cavity receiver for a parabolic concentrating solar collector

    Energy Technology Data Exchange (ETDEWEB)

    Ma, R.Y. [California State Polytechnic Univ., Pomoma, CA (United States). Dept. of Mechanical Engineering

    1993-09-01

    Tests were performed to determine the convective heat loss characteristics of a cavity receiver for a parabolid dish concentrating solar collector for various tilt angles and wind speeds of 0-24 mph. Natural (no wind) convective heat loss from the receiver is the highest for a horizontal receiver orientation and negligible with the reveler facing straight down. Convection from the receiver is substantially increased by the presence of side-on wind for all receiver tilt angles. For head-on wind, convective heat loss with the receiver facing straight down is approximately the same as that for side-on wind. Overall it was found that for wind speeds of 20--24 mph, convective heat loss from the receiver can be as much as three times that occurring without wind.

  3. Tritium permeation losses in HYLIFE-II heat exchanger tubes

    International Nuclear Information System (INIS)

    Longhurst, G.R.; Dolan, T.J.

    1990-01-01

    Tritium permeation through the intermediate heat exchanger of the HYLIFE-II inertial fusion design concept is evaluated for routine operating conditions. The permeation process is modelled using the Lewis analogy combined with surface recombination. It is demonstrated that at very low driving potentials, permeation becomes proportional to the first power of the driving potential. The model predicts that under anticipated conditions the primary cooling loop will pass about 6% of the tritium entering it to the intermediate coolant. Possible approached to reducing tritium permeation are explored. Permeation is limited by turbulent diffusion transport through the molten salt. Hence, surface barriers with impendance factors typical of present technology can do very little to reduce permeation. Low Flibe viscosity is desirable. An efficient tritium removal system operating on the Flibe before it gets to the intermediate heat exchanger is required. Needs for further research are highlighted. 9 refs., 2 figs., 1 tab

  4. Treatment of the loss of ultimate heat sink initiating events in the IRSN level 1 PSA

    International Nuclear Information System (INIS)

    Dupuy, Patricia; Georgescu, Gabriel; Corenwinder, Francois

    2014-01-01

    The total loss of the ultimate heat sink is an initiating event which, even it is mainly of external origin, has been considered in the frame of internal events Level 1 PSA by IRSN. The on-going actions on the development of external hazards PSA and the recent incident of loss of the heat sink induced by the ingress of vegetable matter that occurred in France in 2009 have pointed out the need to improve the modeling of the loss of the heat sink initiating event and sequences to better take into account the fact that this loss may be induced by external hazards and thus affect all the site units. The paper presents the historical steps of the modeling of the total loss of the heat sink, the safety stakes of this modeling, the main assumptions used by IRSN in the associated PSA for the 900 MWe reactors and the results obtained. The total loss of the heat sink was not initially addressed in the safety demonstration of French NPPs. On the basis of the insights of the first probabilistic assessments performed in the 80's, the risks associated to this 'multiple failure situation' turned out to be very significant and design and organisational improvements were implemented on the plants. Reviews of the characterization of external hazards and of their consequences on the installations and French operating feedback have revealed that extreme hazards may induce a total loss of the heat sink. Moreover, the accident that occurred at Fukushima in 2011 has pointed out the risk of such a loss of long duration at all site units in case of extreme hazards. In this context, it seems relevant to further improve the modelling of the total loss of the heat sink by considering the external hazards that may cause this loss. In a first step, IRSN has improved the assumptions and data used in the loss of the heat sink PSA model, in particular by considering that such a loss may affect all the site units. The next challenge will be the deeper analysis of the impact of external hazards on

  5. Heat loss of heat pipelines in insulation moisture conditions with the evaporation

    Directory of Open Access Journals (Sweden)

    Polovnikov Vyacheslav Yu.

    2014-01-01

    Full Text Available Results of numerical simulation of heat and mass transfer in a wet fibroporous material in conditions of evaporation and steam diffusion were obtained. Values of heat and mass fluxes were established. The contribution of evaporation effect to total heat flux and need to consider volume fractions of water and steam into the structure of fibroporous material in calculation of effective thermal conductivity were shown. Nonstationarity of heat and mass transfer in conditions of considered problem can be ignored.

  6. Measuring and heat losses for district heating systems in detached house areas; Maet- och vaermefoerluster foer fjaerrvaermesystem i smaahusomraaden

    Energy Technology Data Exchange (ETDEWEB)

    Cederborg, Frederick; Nordgren, Ola [FVB Sverige ab, Vaesteraas (Sweden)

    2005-07-01

    Within 'low heat load' areas e.g. residential areas, with low energy consumption per individual customer, the resulting relationship between the heat loss and the energy sales is big. For these customers with low energy consumption, in particular during the summer season, concerns have been raised regarding the ability of the heat volume meters to register the true energy consumption. In order to determine the magnitude of the losses, the Swedish District Heating Association, has initiated a measuring project where measurements have been made in two separate residential areas with different system configurations and different temperature control programs. The measurements were performed from May 15, 2003 to September 23, 2004. The main objective for the project was to gather data and to analyse the magnitude of the total losses in the building systems. The relation between the heat losses and the measuring losses was also studied briefly. Two types of systems have been studied, on one hand a conventional district heating area with primary connected houses and on the other hand an area with secondary connected houses with PEX-pipes in Enkoeping. The heat and measuring losses at the area Munksundet in Enkoeping is 17 % at a 'load density' of 0,84. This value is somewhat lower than the accounted annual relative loss of 22-23 % stated in the report 'FVF 1997:11 Fjaerrvaerme till smaahus'. The results show that a secondary connected low temperature system with PEX-pipes is an interesting connection alternative for small houses. Also at the residential area Rotskaer in Skutskaer, the heat and measuring losses are lower than the accounted annual relative loss, about 24 % at a 'load density' of 0,49,which is to be compared with about 33 % annual relative loss according to the report 'FVF 1997:11'. Within this assignment there are difficulties to divide the measuring losses in short circuit flows and errors in the heat

  7. The TX-model - a quantitative heat loss analysis of district heating pipes by means of IR surface temperature measurements

    Energy Technology Data Exchange (ETDEWEB)

    Zinki, Heimo [ZW Energiteknik, Nykoeping (Sweden)

    1996-11-01

    The aim of this study was to investigate the possibility of analysing the temperature profile at the ground surface above buried district heating pipes in such a way that would enable the quantitative determination of heat loss from the pair of pipes. In practical applications, it is supposed that this temperature profile is generated by means of advanced IR-thermography. For this purpose, the principle of the TX - model has been developed, based on the fact that the heat losses from pipes buried in the ground have a temperature signature on the ground surface. Qualitative analysis of this temperature signature is very well known and in practical use for detecting leaks from pipes. These techniques primarily make use of relative changes of the temperature pattern along the pipe. In the quantitative heat loss analysis, however, it is presumed that the temperature profile across the pipes is related to the pipe heat loss per unit length. The basic idea is that the integral of the temperature profile perpendicular to the pipe, called TX, is a function of the heat loss, but is also affected by other parameters such as burial depth, heat diffusivity, wind, precipitation and so on. In order to analyse the parameters influencing the TX- factor, a simulation model for the energy balance at the ground surface has been developed. This model includes the heat flow from the pipe to the surface and the heat exchange at the surface with the environment due to convection, latent heat change, solar and long wave radiation. The simulation gives the surprising result that the TX factor is by and large unaffected during the course of a day even when the sun is shining, as long as other climate conditions are relatively stable (low wind, no rain, no shadows). The results from the simulations were verified at different sites in Denmark, Finland, Sweden and USA through a co-operative research program organised and partially financed by the IEA District Heating Programme, Task III, and

  8. Analysis of unscrammed loss of flow and heat sink for PRISM with GEM

    International Nuclear Information System (INIS)

    Slovik, G.C.; Van Tuyle, G.J.; Kennett, R.J.

    1991-01-01

    The US Department of Energy is sponsoring an advanced liquid-metal reactor design by General Electric Company (GE) called PRISM. The intent is to design a reactor with passively safe responses to many operational and severe accidents. PRISM is under review at the US Nuclear Regulatory Commission for licensability with Brookhaven National Laboratory providing technical assistance. Recently, the PRISM design has been modified to include three gas expansion modules (GEMs) on its core periphery. The GEMs were added to quickly reduce the power (by inserting negative reactivity) during loss-of-flow events to curtail peak fuel and clad temperatures predicted in the previous design. The GEM prototypes have been tested at the Fast Flux Test Facility. The significance of the GEMs in PRISM is discussed in this paper through the evaluation of the unprotected loss of flow (ULOF) and loss of heat sink using the SSC code. It has been demonstrated in the past that SSC predicts results similar to GE and other liquid-metal reactor codes

  9. Emotion regulation reduces loss aversion and decreases amygdala responses to losses.

    Science.gov (United States)

    Sokol-Hessner, Peter; Camerer, Colin F; Phelps, Elizabeth A

    2013-03-01

    Emotion regulation strategies can alter behavioral and physiological responses to emotional stimuli and the neural correlates of those responses in regions such as the amygdala or striatum. The current study investigates the brain systems engaged when using an emotion regulation technique during financial decisions. In decision making, regulating emotion with reappraisal-focused strategies that encourage taking a different perspective has been shown to reduce loss aversion as observed both in choices and in the relative arousal responses to actual loss and gain outcomes. In the current study, we find using fMRI that behavioral loss aversion correlates with amygdala activity in response to losses relative to gains. Success in regulating loss aversion also correlates with the reduction in amygdala responses to losses but not to gains. Furthermore, across both decisions and outcomes, we find the reappraisal strategy increases baseline activity in dorsolateral and ventromedial prefrontal cortex and the striatum. The similarity of the neural circuitry observed to that seen in emotion regulation, despite divergent tasks, serves as further evidence for a role of emotion in decision making, and for the power of reappraisal to change assessments of value and thereby choices.

  10. A model for allometric scaling of mammalian metabolism with ambient heat loss

    KAUST Repository

    Kwak, Ho Sang; Im, Hong G.; Shim, Eun Bo

    2016-01-01

    The finding that additional radiative heat loss and the consideration of an outer insulation fur layer attenuate these deviation effects and render the scaling law closer to 2/3 provides in silico evidence for a functional impact of heat transfer mode on the allometric scaling law in mammalian metabolism.

  11. Effects of loss aversion on neural responses to loss outcomes: An event-related potential study.

    Science.gov (United States)

    Kokmotou, Katerina; Cook, Stephanie; Xie, Yuxin; Wright, Hazel; Soto, Vicente; Fallon, Nicholas; Giesbrecht, Timo; Pantelous, Athanasios; Stancak, Andrej

    2017-05-01

    Loss aversion is the tendency to prefer avoiding losses over acquiring gains of the same amount. To shed light on the spatio-temporal processes underlying loss aversion, we analysed the associations between individual loss aversion and electrophysiological responses to loss and gain outcomes in a monetary gamble task. Electroencephalographic feedback-related negativity (FRN) was computed in 29 healthy participants as the difference in electrical potentials between losses and gains. Loss aversion was evaluated using non-linear parametric fitting of choices in a separate gamble task. Loss aversion correlated positively with FRN amplitude (233-263ms) at electrodes covering the lower face. Feedback related potentials were modelled by five equivalent source dipoles. From these dipoles, stronger activity in a source located in the orbitofrontal cortex was associated with loss aversion. The results suggest that loss aversion implemented during risky decision making is related to a valuation process in the orbitofrontal cortex, which manifests during learning choice outcomes. Copyright © 2017. Published by Elsevier B.V.

  12. Thermal-hydraulic processes involved in loss of residual heat removal during reduced inventory operation

    International Nuclear Information System (INIS)

    Fletcher, C.D.; McHugh, P.R.; Naff, S.A.; Johnsen, G.W.

    1991-02-01

    This paper identifies the topics needed to understand pressurized water reactor response to an extended loss of residual heat removal event during refueling and maintenance outages. By identifying the possible plant conditions and cooling methods that would be used for each cooling mode, the controlling thermal-hydraulic processes and phenomena were identified. Controlling processes and phenomena include: gravity drain, core water boil-off, and reflux cooling processes. Important subcategories of the reflux cooling processes include: the initiation of reflux cooling from various plant conditions, the effects of air on reflux cooling, core level depression effects, issues regarding the steam generator secondaries, and the special case of boiler-condenser cooling with once-through steam generators. 25 refs., 6 figs., 1 tab

  13. Use of infrared thermography for the evaluation of heat losses during coal storage

    NARCIS (Netherlands)

    Fierro, V.; Miranda, J.L.; Romero, C.; Andrés, J.M.; Pierrot, A.; Gómez-Landesa, E.; Arriaga, A.; Schmal, D.

    1999-01-01

    The exothermic processes during coal storage reduce the calorific value of the coal which in turn results in financial losses. An accurate and easy calculation of the losses may be an efficient tool to evaluate the effectiveness of the measures taken to reduce the spontaneous heating of coal and to

  14. A model for particle and heat losses by type I edge localized modes

    International Nuclear Information System (INIS)

    Tokar, M Z; Gupta, A; Kalupin, D; Singh, R

    2007-01-01

    A model to estimate the particle and energy losses caused in tokamaks by type I edge localized modes (ELMs) is proposed. This model is based on the assumption that the increase in transport by ELM is due to flows along magnetic field lines perturbed by ballooning-peeling MHD modes. The model reproduces well the experimentally found variation of losses with the plasma collisionality ν*, namely, the weak dependence of the particle loss and significant reduction of the energy loss with increasing ν*. It is argued that the electron parallel heat conductivity is dominating in the energy loss at not very large ν*

  15. SCDAP/RELAP5 Modeling of Heat Transfer and Flow Losses in Lower Head Porous Debris

    International Nuclear Information System (INIS)

    Coryell, E.W.; Siefken, L.J.; Paik, S.

    1998-01-01

    Designs are described for implementing models for calculating the heat transfer and flow losses in porous debris in the lower head of a reactor vessel. The COUPLE model in SCDAP/RELAP5 represents both the porous and non-porous debris that results from core material slumping into the lower head. Currently, the COUPLE model has the capability to model convective and radiative heat transfer from the surfaces of non-porous debris in a detailed manner and to model only in a simplistic manner the heat transfer from porous debris. In order to advance beyond the simplistic modeling for porous debris, designs are developed for detailed calculations of heat transfer and flow losses in porous debris. Correlations are identified for convective heat transfer in porous debris for the following modes of heat transfer; (1) forced convection to liquid, (2) forced convection to gas, (3) nucleate boiling, (4) transition boiling, and (5) film boiling. Interphase heat transfer is modeled in an approximate manner. A design is also described for implementing a model of heat transfer by radiation from debris to the interstitial fluid. A design is described for implementation of models for flow losses and interphase drag in porous debris. Since the models for heat transfer and flow losses in porous debris in the lower head are designed for general application, a design is also described for implementation of these models to the analysis of porous debris in the core region. A test matrix is proposed for assessing the capability of the implemented models to calculate the heat transfer and flow losses in porous debris. The implementation of the models described in this report is expected to improve the COUPLE code calculation of the temperature distribution in porous debris and in the lower head that supports the debris. The implementation of these models is also expected to improve the calculation of the temperature and flow distribution in porous debris in the core region

  16. Effect of heterogenous and homogenous air gaps on dry heat loss through the garment

    Science.gov (United States)

    Mert, Emel; Psikuta, Agnes; Bueno, Marie-Ange; Rossi, René M.

    2015-11-01

    In real life conditions, the trapped air between the human body and the garment has uneven shape and vary over the body parts as a consequence of the complex geometry of the human body. However, the existing clothing models assume uniform air layer between the human body and the garment or its full contact, which may cause large error in the output of simulations. Therefore, the aim of this study was to investigate the effect of a heterogeneous vertical air gap with different configuration of folds (size and frequency) on dry heat loss using a heated cylinder (Torso). It was found that the presence of folds in the garment led to an increased heat loss from the body in comparison to a homogeneous air gap of comparable size. Interestingly, the size of folds did not have an influence on the dry heat loss. Additionally, the effect of the contact area on dry heat loss became important when exceeding a threshold of about 42 %. The results from this study are useful for modelling of a realistic dry heat loss through the clothing and contribute to the improvement of design of protective and active sport garments.

  17. Thermal stratification in a hot water tank established by heat loss from the tank

    DEFF Research Database (Denmark)

    Fan, Jianhua; Furbo, Simon

    2009-01-01

    Results of experimental and numerical investigations of thermal stratification and natural convection in a vertical cylindrical hot water tank during standby periods are presented. The transient fluid flow and heat transfer in the tank during cooling caused by heat loss are investigated...... on the natural buoyancy resulting in downward flow along the tank side walls due to heat loss of the tank and the influence on thermal stratification of the tank by the downward flow and the corresponding upward flow in the central parts of the tank. Water temperatures at different levels of the tank...... by computational fluid dynamics (CFD) calculations and by thermal measurements. A tank with uniform temperatures and thermal stratification is studied. The distribution of the heat loss coefficient for the different parts of the tank is measured by tests and used as input to the CFD model. The investigations focus...

  18. Heat losses and thermal imaging of ferroic components

    International Nuclear Information System (INIS)

    Ilyashenko, S E; Ivanova, A I; Gasanov, O V; Grechishkin, R M; Tretiakov, S A; Yushkov, K B; Linde, B B J

    2015-01-01

    A study is made of spatial and temporal temperature variations in working devices based on ferroic functional materials. The measurement of the sample's temperature is complemented with direct observation of its distribution over the sample surface. For the latter purpose a thermovision infrared videocamera technique was employed. Specific features of the temperature distribution and its evolution during heating and cooling of a number of piezoelectric, acoustooptic and shape memory components are revealed. Examples of hot spot observations indicative of structural defects in the samples under study are given thus suggesting the use of thermal vision for nondestructive testing. A proposal is made to combine the thermovision method with that of thermomagnetic analysis for the study of ferromagnetic shape memory alloys

  19. Heat losses and thermal performance of commercial combined solar and pellet heating systems

    OpenAIRE

    Fiedler, Frank; Persson, Tomas; Bales, Chris; Nordlander, Svante

    2004-01-01

    Various pellet heating systems are marketed in Sweden, some of them in combination with a solar heating system. Several types of pellet heating units are available and can be used for a combined system. This article compares four typical combined solar and pellet heating systems: System 1 and 2 two with a pellet stove, system 3 with a store integrated pellet burner and system 4 with a pellet boiler. The lower efficiency of pellet heaters compared to oil or gas heaters increases the primary en...

  20. Experimental investigations on heat content of supercooled sodium acetate trihydrate by a simple heat loss method

    DEFF Research Database (Denmark)

    Kong, Weiqiang; Dannemand, Mark; Johansen, Jakob Berg

    2016-01-01

    Sodium acetate trihydrate is a phase change material that can be used for long term heat storage in solar heating systems because of its relatively high heat of fusion, a melting temperature of 58 °C and its ability to supercool stable. In practical applications sodium acetate trihydrate tend to ......, 0.3–0.5 % (wt.%) Xanthan Gum or 1–2% (wt.%) of some solid or liquid polymers as additives had significantly higher heat contents compared to samples of sodium acetate trihydrate suffering from phase separation....

  1. Sauropod necks: are they really for heat loss?

    Directory of Open Access Journals (Sweden)

    Donald M Henderson

    Full Text Available Three-dimensional digital models of 16 different sauropods were used to examine the scaling relationship between metabolism and surface areas of the whole body, the neck, and the tail in an attempt to see if the necks could have functioned as radiators for the elimination of excess body heat. The sauropod taxa sample ranged in body mass from a 639 kg juvenile Camarasaurus to a 25 t adult Brachiosaurus. Metabolism was assumed to be directly proportional to body mass raised to the ¾ power, and estimates of body mass accounted for the presence of lungs and systems of air sacs in the trunk and neck. Surface areas were determined by decomposing the model surfaces into triangles and their areas being computed by vector methods. It was found that total body surface area was almost isometric with body mass, and that it showed negative allometry when plotted against metabolic rate. In contrast, neck area showed positive allometry when plotted against metabolic rate. Tail area show negative allometry with respect to metabolic rate. The many uncertainties about the biology of sauropods, and the variety of environmental conditions that different species experienced during the groups 150 million years of existence, make it difficult to be absolutely certain about the function of the neck as a radiator. However, the functional combination of the allometric increase of neck area, the systems of air sacs in the neck and trunk, the active control of blood flow between the core and surface of the body, changing skin color, and strategic orientation of the neck with respect to wind, make it plausible that the neck could have functioned as a radiator to avoid over-heating.

  2. Enhanced O2 Loss at Mars Due to an Ambipolar Electric Field from Electron Heating

    Science.gov (United States)

    Ergun, R. E.; Andersson, L. A.; Fowler, C. M.; Woodson, A. K.; Weber, T. D.; Delory, G. T.; Andrews, D. J.; Eriksson, A. I.; Mcenulty, T.; Morooka, M. W.; hide

    2016-01-01

    Recent results from the MAVEN Langmuir Probe and Waves (LPW) instrument suggest higher than predicted electron temperatures (T sub e) in Mars dayside ionosphere above approx. 180 km in altitude. Correspondingly, measurements from Neutral Gas and Ion Mass Spectrometer (NGIMS) indicate significant abundances of O2+ up to approx. 500 km in altitude, suggesting that O2+ may be a principal ion loss mechanism of oxygen. In this article, we investigate the effects of the higher T(sub e) (which results from electron heating) and ion heating on ion outflow and loss. Numerical solutions show that plasma processes including ion heating and higher T(sub e) may greatly increase O2+ loss at Mars. In particular, enhanced T(sub e) in Mars ionosphere just above the exobase creates a substantial ambipolar electric field with a potential (e) of several k(sub b)T(sub e), which draws ions out of the region allowing for enhanced escape. With active solar wind, electron and ion heating, direct O2+ loss could match or exceed loss via dissociative recombination of O2+. These results suggest that direct loss of O2+ may have played a significant role in the loss of oxygen at Mars over time.

  3. SCDAP/RELAP5 Modeling of Heat Transfer and Flow Losses in Lower Head Porous Debris

    International Nuclear Information System (INIS)

    Siefken, Larry James; Coryell, Eric Wesley; Paik, Seungho; Kuo, Han Hsiung

    1999-01-01

    Designs are described for implementing models for calculating the heat transfer and flow losses in porous debris in the lower head of a reactor vessel. The COUPLE model in SCDAP/RELAP5 represents both the porous and nonporous debris that results from core material slumping into the lower head. Currently, the COUPLE model has the capability to model convective and radiative heat transfer from the surfaces of nonporous debris in a detailed manner and to model only in a simplistic manner the heat transfer from porous debris. In order to advance beyond the simplistic modeling for porous debris, designs are developed for detailed calculations of heat transfer and flow losses in porous debris. Correlations are identified for convective heat transfer in porous debris for the following modes of heat transfer; (1) forced convection to liquid, (2) forced convection to gas, (3) nucleate boiling, (4) transition boiling, and (5) film boiling. Interphase heat transfer is modeled in an approximate manner. Designs are described for models to calculate the flow losses and interphase drag of fluid flowing through the interstices of the porous debris, and to apply these variables in the momentum equations in the RELAP5 part of the code. Since the models for heat transfer and flow losses in porous debris in the lower head are designed for general application, a design is also described for implementation of these models to the analysis of porous debris in the core region. A test matrix is proposed for assessing the capability of the implemented models to calculate the heat transfer and flow losses in porous debris. The implementation of the models described in this report is expected to improve the COUPLE code calculation of the temperature distribution in porous debris and in the lower head that supports the debris. The implementation of these models is also expected to improve the calculation of the temperature and flow distribution in porous debris in the core region

  4. Heat Loss Measurements in Buildings Utilizing a U-value Meter

    DEFF Research Database (Denmark)

    Sørensen, Lars Schiøtt

    Heating of buildings in Denmark accounts for approximately 40% of the entire national energy consumption. For this reason, a reduction of heat losses from building envelopes are of great importance in order to reach the Bologna CO2 emission reduction targets. Upgrading of the energy performance...... of buildings is a topic of huge global interest these years. Not only heating in the temperate and arctic regions are important, but also air conditioning and mechanical ventilation in the tropical countries contribute to an enormous energy consumption and corresponding CO2 emission. In order to establish...... the best basis for upgrading the energy performance, it is important to measure the heat losses at different locations on a building facade, in order to optimize the energy performance. The author has invented a U-value meter, enabling measurements of heat transfer coefficients. The meter has been used...

  5. Effect of energetic ion loss on ICRF heating efficiency and energy confinement time in heliotrons

    International Nuclear Information System (INIS)

    Murakami, S.; Nakajima, N.; Okamoto, M.; Nuehrenberg, J.

    1999-06-01

    ICRF heating efficiency and the global energy confinement time during ICRF heating are investigated including the effect of energetic ion loss in heliotrons. The approximate formula of ICRF heating efficiency is derived using the results based on Monte Carlo simulations. The global energy confinement time including energetic ion effect can be expressed in terms of ICRF heating power, plasma density, and magnetic field strength in heliotrons. Our results in the CHS plasma show the systematic decrement of the global energy confinement time due to the energetic ion loss from the assumed energy confinement scaling law, which is consistent with the experimental observations. Also we apply our model to the ICRF minority heating in the LHD plasma in two cases of typical magnetic configurations. The clear increment of the global energy confinement time due to the stored energy of energetic tail ions is obtained in the 'orbit improved' configuration, while the decrement is observed in the 'standard' configuration. (author)

  6. Automatic hearing loss detection system based on auditory brainstem response

    International Nuclear Information System (INIS)

    Aldonate, J; Mercuri, C; Reta, J; Biurrun, J; Bonell, C; Gentiletti, G; Escobar, S; Acevedo, R

    2007-01-01

    Hearing loss is one of the pathologies with the highest prevalence in newborns. If it is not detected in time, it can affect the nervous system and cause problems in speech, language and cognitive development. The recommended methods for early detection are based on otoacoustic emissions (OAE) and/or auditory brainstem response (ABR). In this work, the design and implementation of an automated system based on ABR to detect hearing loss in newborns is presented. Preliminary evaluation in adults was satisfactory

  7. Genetic and epigenetic control of plant heat responses

    Directory of Open Access Journals (Sweden)

    Junzhong eLiu

    2015-04-01

    Full Text Available Plants have evolved sophisticated genetic and epigenetic regulatory systems to respond quickly to unfavorable environmental conditions such as heat, cold, drought, and pathogen infections. In particular, heat greatly affects plant growth and development, immunity and circadian rhythm, and poses a serious threat to the global food supply. According to temperatures exposing, heat can be usually classified as warm ambient temperature (about 22-27℃, high temperature (27-30℃ and extremely high temperature (37-42℃, also known as heat stress for the model plant Arabidopsis thaliana. The genetic mechanisms of plant responses to heat have been well studied, mainly focusing on elevated ambient temperature-mediated morphological acclimation and acceleration of flowering, modulation of plant immunity and circadian clock by high temperatures, and thermotolerance to heat stress. Recently, great progress has been achieved on epigenetic regulation of heat responses, including DNA methylation, histone modifications, histone variants, ATP-dependent chromatin remodeling, histone chaperones, small RNAs, long non-coding RNAs and other undefined epigenetic mechanisms. These epigenetic modifications regulate the expression of heat-responsive genes and function to prevent heat-related damage. This review focuses on recent progresses regarding the genetic and epigenetic control of heat responses in plants, and pays more attention to the role of the major epigenetic mechanisms in plant heat responses. Further research perspectives are also discussed.

  8. Remarkable separability of the circulation response to Arctic sea ice loss and greenhouse gas forcing

    Science.gov (United States)

    McCusker, K. E.; Kushner, P. J.; Fyfe, J. C.; Sigmond, M.; Kharin, V. V.; Bitz, C. M.

    2017-12-01

    Arctic sea ice loss has an important effect on local climate through increases in ocean to atmosphere heat flux and associated feedbacks, and may influence midlatitude climate by changing large-scale circulation that can enhance or counter changes that are due to greenhouse gases. The extent to which climate change in a warming world can be understood as greenhouse gas-induced changes that are modulated by Arctic sea ice loss depends on how additive the responses to the separate influences are. Here we use a novel sea ice nudging methodology in the Canadian Earth System Model, which has a fully coupled ocean, to isolate the effects of Arctic sea ice loss and doubled atmospheric carbon dioxide (CO2) to determine their additivity and sensitivity to mean state. We find that the separate effects of Arctic sea ice loss and doubled CO2 are remarkably additive and relatively insensitive to mean climate state. This separability is evident in several thermodynamic and dynamic fields throughout most of the year, from hemispheric to synoptic scales. The extent to which the regional response to sea ice loss sometimes agrees with and sometimes cancels the response to CO2 is quantified. In this model, Arctic sea ice loss enhances the CO2-induced surface air temperature changes nearly everywhere and zonal wind changes over the Pacific sector, whereas sea ice loss counters CO2-induced sea level pressure changes nearly everywhere over land and zonal wind changes over the Atlantic sector. This separability of the response to Arctic sea ice loss from the response to CO2 doubling gives credence to the body of work in which Arctic sea ice loss is isolated from the forcing that modified it, and might provide a means to better interpret the diverse array of modeling and observational studies of Arctic change and influence.

  9. A model for allometric scaling of mammalian metabolism with ambient heat loss

    KAUST Repository

    Kwak, Ho Sang

    2016-02-02

    Background Allometric scaling, which represents the dependence of biological trait or process relates on body size, is a long-standing subject in biological science. However, there has been no study to consider heat loss to the ambient and an insulation layer representing mammalian skin and fur for the derivation of the scaling law of metabolism. Methods A simple heat transfer model is proposed to analyze the allometry of mammalian metabolism. The present model extends existing studies by incorporating various external heat transfer parameters and additional insulation layers. The model equations were solved numerically and by an analytic heat balance approach. Results A general observation is that the present heat transfer model predicted the 2/3 surface scaling law, which is primarily attributed to the dependence of the surface area on the body mass. External heat transfer effects introduced deviations in the scaling law, mainly due to natural convection heat transfer which becomes more prominent at smaller mass. These deviations resulted in a slight modification of the scaling exponent to a value smaller than 2/3. Conclusion The finding that additional radiative heat loss and the consideration of an outer insulation fur layer attenuate these deviation effects and render the scaling law closer to 2/3 provides in silico evidence for a functional impact of heat transfer mode on the allometric scaling law in mammalian metabolism.

  10. Morphological dependency of cutaneous blood flow and sweating during compensable heat stress when heat-loss requirements are matched across participants.

    Science.gov (United States)

    Notley, Sean R; Park, Joonhee; Tagami, Kyoko; Ohnishi, Norikazu; Taylor, Nigel A S

    2016-07-01

    Human heat loss is thought, in part, to be morphologically related. It was therefore hypothesized that when heat-loss requirements and body temperatures were matched, that the mass-specific surface area alone could significantly explain both cutaneous vascular and sudomotor responses during compensable exercise. These thermoeffector responses were examined in 36 men with widely varying mass-specific surface areas (range, 232.3-292.7 cm(2)/kg), but of similar age, aerobic fitness, and adiposity. Subjects completed two trials under compensable conditions (28.1°C, 36.8% relative humidity), each involving rest (20 min) and steady-state cycling (45 min) at two matched metabolic heat-production rates (light, ∼135 W/m(2); moderate, ∼200 W/m(2)). Following equivalent mean body temperature changes, forearm blood flow and vascular conductance (r = 0.63 and r = 0.65) shared significant, positive associations with the mass-specific surface area during light work (P < 0.05), explaining ∼45% of the vasomotor variation. Conversely, during light and moderate work, whole body sweat rate, as well as local sweat rate and sudomotor sensitivity at three of four measured sites, revealed moderate, negative relationships with the mass-specific surface area (correlation coefficient range -0.37 to -0.73, P < 0.05). Moreover, those relationships could uniquely account for between 10 and 53% of those sweating responses (P < 0.05). Therefore, both thermoeffector responses displayed a significant morphological dependency in the presence of equivalent thermoafferent drive. Indeed, up to half of the interindividual variation in these effector responses could now be explained through morphological differences and the first principles governing heat transfer. Copyright © 2016 the American Physiological Society.

  11. Enhanced loss of fusion products during mode conversion heating in TFTR

    International Nuclear Information System (INIS)

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

    1995-07-01

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

  12. Tunneling of heat: Beyond linear response regime

    Science.gov (United States)

    Walczak, Kamil; Saroka, David

    2018-02-01

    We examine nanoscale processes of heat (energy) transfer as carried by electrons tunneling via potential barriers and molecular interconnects between two heat reservoirs (thermal baths). For that purpose, we use Landauer-type formulas to calculate thermal conductance and quadratic correction to heat flux flowing via quantum systems. As an input, we implement analytical expressions for transmission functions related to simple potential barriers and atomic bridges. Our results are discussed with respect to energy of tunneling electrons, temperature, the presence of resonant states, and specific parameters characterizing potential barriers as well as heat carriers. The simplicity of semi-analytical models developed by us allows to fit experimental data and extract crucial information about the values of model parameters. Further investigations are expected for more realistic transmission functions, while time-dependent aspects of nanoscale heat transfer may be addressed by using the concept of wave packets scattered on potential barriers and point-like defects within regular (periodic) nanostructures.

  13. Extra Heat Loss Through Light Weight Roofs Due to Latent Heat

    DEFF Research Database (Denmark)

    Rode, Carsten

    1996-01-01

    that changes phase at the terminals of its passage.Note however, that convection of air most often will have an important effect on the overall heat flow - but that is a different topic.Macroscopic latent heat transferConsider the following scenario: Initially, moisture is present in its condensed or frozen......This report is one in a series of papers in Task 5 of IEA Annex 24 on how moisture and air movements affect the energy performance of building constructions. The effect of latent heat flow will be demonstrated by means of an example: a light weight flat roof.Latent heat flow is one of three...... processes by which moisture affects energy performance:Higher thermal conductivityMoist materials have higher thermal con-ductivity than when they are dry. This is because thermally conducting moisture replaces the better insulating air in the pores of the materials. Moisture also enhan-ces the thermal...

  14. Social media responses to heat waves

    Science.gov (United States)

    Jung, Jihoon; Uejio, Christopher K.

    2017-07-01

    Social network services (SNSs) may benefit public health by augmenting surveillance and distributing information to the public. In this study, we collected Twitter data focusing on six different heat-related themes (air conditioning, cooling center, dehydration, electrical outage, energy assistance, and heat) for 182 days from May 7 to November 3, 2014. First, exploratory linear regression associated outdoor heat exposure to the theme-specific tweet counts for five study cities (Los Angeles, New York, Chicago, Houston, and Atlanta). Next, autoregressive integrated moving average (ARIMA) time series models formally associated heat exposure to the combined count of heat and air conditioning tweets while controlling for temporal autocorrelation. Finally, we examined the spatial and temporal distribution of energy assistance and cooling center tweets. The result indicates that the number of tweets in most themes exhibited a significant positive relationship with maximum temperature. The ARIMA model results suggest that each city shows a slightly different relationship between heat exposure and the tweet count. A one-degree change in the temperature correspondingly increased the Box-Cox transformed tweets by 0.09 for Atlanta, 0.07 for Los Angeles, and 0.01 for New York City. The energy assistance and cooling center theme tweets suggest that only a few municipalities used Twitter for public service announcements. The timing of the energy assistance tweets suggests that most jurisdictions provide heating instead of cooling energy assistance.

  15. Thermal performance of a porus radial fin with natural convection and radiative heat losses

    Directory of Open Access Journals (Sweden)

    Darvishi M.T.

    2015-01-01

    Full Text Available An analytic (series solution is developed to describe the thermal performance of a porous radial fin with natural convection in the fluid saturating the fin and radiation heat loss from the top and bottom surfaces of the fin. The HAM results for the temperature distribution and base heat flux are compared with the direct numerical results and found to be very accurate.

  16. Reducing heat loss from the energy absorber of a solar collector

    Science.gov (United States)

    Chao, Bei Tse; Rabl, Ari

    1976-01-01

    A device is provided for reducing convective heat loss in a cylindrical radiant energy collector. It includes a curved reflective wall in the shape of the arc of a circle positioned on the opposite side of the exit aperture from the reflective side walls of the collector. Radiant energy exiting the exit aperture is directed by the curved wall onto an energy absorber such that the portion of the absorber upon which the energy is directed faces downward to reduce convective heat loss from the absorber.

  17. Uncertainty in unprotected loss-of-heat-sink, loss-of-flow, and transient-overpower accidents.

    Energy Technology Data Exchange (ETDEWEB)

    Morris, E. E.; Nuclear Engineering Division

    2007-10-08

    The sensitivities of various output parameters to selected input parameters in unprotected combined loss of heat-sink and loss-of-flow (ULOHS), loss-of-flow (ULOF), and transient-overpower (UTOP) accidents are explored in this report. This line of investigation was suggested by R. A. Wigeland. For an initial examination of potential sensitivities, the MATWS computer program has been compiled as part of a dynamic link library (DLL) so that uncertain input parameters can be sampled from their probability distributions using the GoldSim simulation software. The MATWS program combines the point-kinetics module from the SAS4A/SASSYS computer code with a simplified representation of the reactor heat removal system. Coupling with the GoldSim software by means of a DLL not only provides a convenient mechanism for sampling the stochastic input parameters but also allows the use of various tools that are available in GoldSim for analyzing the dependence of various MATWS outputs on these parameters. Should a decision be made to continue this investigation, the techniques used to couple MATWS and GoldSim could also be applied to couple the SAS4A/SASSYS computer code with GoldSim. The work described here illustrates the type of results that can be obtained from the stochastic analysis.

  18. Uncertainty in unprotected loss-of-heat-sink, loss-of-flow, and transient-overpower accidents

    International Nuclear Information System (INIS)

    Morris, E.E.

    2007-01-01

    The sensitivities of various output parameters to selected input parameters in unprotected combined loss of heat-sink and loss-of-flow (ULOHS), loss-of-flow (ULOF), and transient-overpower (UTOP) accidents are explored in this report. This line of investigation was suggested by R. A. Wigeland. For an initial examination of potential sensitivities, the MATWS computer program has been compiled as part of a dynamic link library (DLL) so that uncertain input parameters can be sampled from their probability distributions using the GoldSim simulation software. The MATWS program combines the point-kinetics module from the SAS4A/SASSYS computer code with a simplified representation of the reactor heat removal system. Coupling with the GoldSim software by means of a DLL not only provides a convenient mechanism for sampling the stochastic input parameters but also allows the use of various tools that are available in GoldSim for analyzing the dependence of various MATWS outputs on these parameters. Should a decision be made to continue this investigation, the techniques used to couple MATWS and GoldSim could also be applied to couple the SAS4A/SASSYS computer code with GoldSim. The work described here illustrates the type of results that can be obtained from the stochastic analysis

  19. Feelings of Loss in Response to Divorce: Assessment and Intervention.

    Science.gov (United States)

    Huber, Charles H.

    1983-01-01

    Presents a cognitively based model, founded on rational emotive therapy, as a basis for assessment and intervention strategies for assisting individuals to cope with feelings of loss in response to divorce. The model is seen as a four-pane window through which persons might see their divorce. (Author/JAC)

  20. Application of response theory to steam venting during a loss of AC power transient

    Energy Technology Data Exchange (ETDEWEB)

    Cady, K.B.; Miller, R.J.

    1987-05-01

    We have applied the theory of response to the loss of AC power transient for an LMFBR design to determine the ultimate loss of coolant inventory and the sensitivity of this figure with respect to the initial conditions and input parameters. Using a simple four region heat transfer model, the analysis shows that 3717 kg coolant are vented after feed water is lost and before venting stops. The sensitivity analysis reveals that this figure is strongly dependent on design parameters and system assumptions. The uncertainty in the lost inventory caused by the uncertainties and correlations in the input parameters and initial conditions is found to be 3464 kg. We thus report the result of the calculation as lost inventory (kg)=3717+-3464 and conclude that the available inventory of 8775 kg is sufficient to ensure an adequate heat sink.

  1. Systematic losses of outdoor production from heat stress and climate change

    Science.gov (United States)

    Buzan, J. R.; Huber, M.

    2017-12-01

    Heat stress impacts humans today with heat waves, worker reductions, and health issues. Here we show novel results in labor productivity for outdoor work due to global warming. We use the HumanIndexMod to calculate 4x daily values of Simplified Wet Bulb Globe Temperature index (sWBGT) from the CMIP5 archive normalized by global mean surface temperature changes. Previous work shows that scaling of sWBGT is robust across the CMIP5 archive. We calculate total annual outdoor labor capacity from our scaled sWBGT results. Our results show modern day losses due to heat stress impacting outdoor work for low latitudes (and parts of Eastern China and the Southern United States). At 2°C of climate change, up to 20% losses to total capacity impact Midwestern United States, while the Southern United States suffers >20% losses. Western Coastal Africa suffers annual losses at >80%, along with the Amazon Basin and the greater South East Asia region. India suffers losses >50% annually. At +5°C, the estimated mean global change by 2100, the Equatorial region (Northern Australia and Northern Bolivia to Western Coastal Africa and Southern India) has complete cessation of annual outdoor work. The Midwest United States suffers losses up to 30%, and the Gulf of Mexico suffers losses >50%. Our results imply that small changes in global mean surface temperature (2°C) will lead to crippling losses to outdoor work annually, and ≥5°C losses will lead to cessation of labor for more than half the world's population.

  2. Enhanced loss of fast ions during mode conversion ion Bernstein wave heating in TFTR

    International Nuclear Information System (INIS)

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

    1995-12-01

    A strong interaction of fast ions with ion Bernstein waves has been observed in TFTR. It results in a large increase in the fast ion loss rate, and heats the lost particles to several MeV. The lost ions are observed at the passing/trapped boundary and appear to be either DD fusion produced tritons or accelerated D neutral beam ions. Under some conditions, enhanced loss of DT alpha particles is also seen. The losses provide experimental support for some of the elements required for alpha energy channeling

  3. Minimum success criteria at SGTR combined with loss of secondary heat sink

    International Nuclear Information System (INIS)

    Parzer, I.; Petelin, S.

    1993-01-01

    A parametric analysis has been performed investigating minimum success criteria for the hypothetical Steam Generator Tube Rupture (SGTR) accident in a Pressurized Water Reactor (PWR) Nuclear Power Plant, combined with the total loss of secondary heat sink. The analyses have been performed by RELAP5/MOD2 and MOD3 computer codes using Krsko NPP input deck. The Krsko NPP is a 2-loop Westinghouse PWR, 640 MWe, located in Slovenia and operating from 1981. Two break sizes have been chosen for the SGTR event: 2 and 5 double-ended broken tubes have been assumed. Total loss of secondary heat sink has been assumed from the beginning of the calculation. The ways of cooling down the plant after the postulated accident have been investigated, including Bleed ampersand Feed through the primary system. The NPP Krsko Emergency Operating Procedures (EOP) have been verified for this case. Some suggestions have been made, how to improve FR-H.1 procedure (Loss of Secondary Heat Sink), to include some steps, which take into account also SGTR when it is combined with loss of secondary heat sink. Possible misinterpretations of E-0 procedure (Reactor Trip or Safety Injection) have been studied

  4. Turbomachinery Heat Transfer and Loss Modeling for 3D Navier-Stokes Codes

    Science.gov (United States)

    DeWitt, Kenneth; Ameri, Ali

    2005-01-01

    This report's contents focus on making use of NASA Glenn on-site computational facilities,to develop, validate, and apply models for use in advanced 3D Navier-Stokes Computational Fluid Dynamics (CFD) codes to enhance the capability to compute heat transfer and losses in turbomachiney.

  5. The influence of soil moisture transfer on building heat loss via the ground

    NARCIS (Netherlands)

    Janssen, H.M.; Carmeliet, J.; Hens, H.

    2004-01-01

    In this paper, the influence of soil moisture transfer on building heat loss via the ground is investigated by comparing fully coupled simulations with linear thermal simulations. The observed influences of coupling are (1) the larger amplitude of surface temperature, (2) the variation of thermal

  6. Possible biphasic sweating response during short-term heat acclimation protocol for tropical natives.

    Science.gov (United States)

    Magalhães, Flávio de Castro; Machado-Moreira, Christiano Antônio; Vimieiro-Gomes, Ana Carolina; Silami-Garcia, Emerson; Lima, Nilo Resende Viana; Rodrigues, Luiz Oswaldo Carneiro

    2006-05-01

    The aim of the present study was to evaluate the sweat loss response during short-term heat acclimation in tropical natives. Six healthy young male subjects, inhabitants of a tropical region, were heat acclimated by means of nine days of one-hour heat-exercise treatments (40+/-0 degrees C and 32+/-1% relative humidity; 50% (.)VO(2peak) on a cycle ergometer). On days 1 to 9 of heat acclimation whole-body sweat loss was calculated by body weight variation corrected for body surface area. On days 1 and 9 rectal temperature (T(re)) and heart rate (HR) were measured continuously, and rating of perceived exertion (RPE) every 4 minutes. Heat acclimation was confirmed by reduced HR (day 1 rest: 77+/-5 b.min(-1); day 9 rest: 68+/-3 b.min(-1); day 1 final exercise: 161+/-15 b.min(-1); day 9 final exercise: 145+/-11 b.min(-1), p0.05) of the protocol. These findings are consistent with the heat acclimation induced adaptations and suggest a biphasic sweat response (an increase in the sweat rate in the middle of the protocol followed by return to initial values by the end of it) during short-term heat acclimation in tropical natives.

  7. The effect of wind on the rate of heat loss from avian cup-shaped nests.

    Science.gov (United States)

    Heenan, Caragh B; Seymour, Roger S

    2012-01-01

    Forced convection can significantly influence the heat loss from birds and their offspring but effects may be reduced by using sheltered micro-sites such as cavities or constructing nests. The structural and thermal properties of the nests of two species, the spiny-cheeked honeyeater (Acanthagenys rufogularis) and yellow-throated miner (Manorina flavigula), were measured in relation to three wind speeds. Nest dimensions differ between the two species, despite the similar body mass of the incubating adults, however nest conductance is comparable. As wind speed increases, so does the rate of heat loss from the nests of both species, and further still during incubation recesses. The significance of forced convection through the nest is a near-doubling in heat production required by the parent, even when incubating at relatively low wind speeds. This provides confirmation that selecting a sheltered nest site is important for avian reproductive success.

  8. The effect of wind on the rate of heat loss from avian cup-shaped nests.

    Directory of Open Access Journals (Sweden)

    Caragh B Heenan

    Full Text Available Forced convection can significantly influence the heat loss from birds and their offspring but effects may be reduced by using sheltered micro-sites such as cavities or constructing nests. The structural and thermal properties of the nests of two species, the spiny-cheeked honeyeater (Acanthagenys rufogularis and yellow-throated miner (Manorina flavigula, were measured in relation to three wind speeds. Nest dimensions differ between the two species, despite the similar body mass of the incubating adults, however nest conductance is comparable. As wind speed increases, so does the rate of heat loss from the nests of both species, and further still during incubation recesses. The significance of forced convection through the nest is a near-doubling in heat production required by the parent, even when incubating at relatively low wind speeds. This provides confirmation that selecting a sheltered nest site is important for avian reproductive success.

  9. Experimentally-determined external heat loss of automotive gas turbine engine

    Science.gov (United States)

    Meng, P. R.; Wulf, R. F.

    1975-01-01

    An external heat balance was conducted on a 150 HP two-shaft automotive gas turbine engine. The engine was enclosed in a calorimeter box and the temperature change of cooling air passing through the box was measured. Cooling airflow ranges of 1.6 to 2.1 lb-per-second and 0.8 to 1.1 lb-per-second were used. The engine housing heat loss increased as the cooling airflow through the calorimeter box was increased, as would be the case in a moving automobile. The heat balance between the total energy input and the sum of shaft power output and various losses compared within 30 percent at engine idle speeds and within 7 percent at full power.

  10. Effect of Wind Flow on Convective Heat Losses from Scheffler Solar Concentrator Receivers

    Science.gov (United States)

    Nene, Anita Arvind; Ramachandran, S.; Suyambazhahan, S.

    2018-05-01

    Receiver is an important element of solar concentrator system. In a Scheffler concentrator, solar rays get concentrated at focus of parabolic dish. While radiation losses are more predictable and calculable since strongly related to receiver temperature, convective looses are difficult to estimate in view of additional factors such as wind flow direction, speed, receiver geometry, prior to current work. Experimental investigation was carried out on two geometries of receiver namely cylindrical and conical with 2.7 m2 Scheffler to find optimum condition of tilt to provide best efficiency. Experimental results showed that as compared to cylindrical receiver, conical receiver gave maximum efficiency at 45° tilt angle. However effect of additional factors like wind speed, wind direction on especially convective losses could not be separately seen. The current work was undertaken to investigate further the same two geometries using computation fluid dynamics using FLUENT to compute convective losses considering all variables such at tilt angle of receiver, wind velocity and wind direction. For cylindrical receiver, directional heat transfer coefficient (HTC) is remarkably high to tilt condition meaning this geometry is critical to tilt leading to higher convective heat losses. For conical receiver, directional average HTC is remarkably less to tilt condition leading to lower convective heat loss.

  11. Responses to Small Break Loss of Coolant Accidents for SMART

    International Nuclear Information System (INIS)

    Bae, Kyoo Hwan; Kim, Hee C.; Chang, Moon H.; Zee, Sung Q.; Kim, Si-Hwan; Lee, Un-Chul

    2004-01-01

    The SMART NSSS adopts the design characteristics of containing most of the primary circuit components, such as the reactor core, main coolant pumps (MCPs), steam generators (SGs), and N 2 gas pressurizer (PZR) in a single leak-tight Reactor Pressure Vessel (RPV) with a relatively large ratio of the primary coolant inventory to the core power compared to the conventional loop-type PWR. Due to these design characteristics, the SMART can fundamentally eliminate the possibility of Large Break Loss of Coolant Accidents (LBLOCAs), improve the natural circulation capability, and assure a sufficient time to mitigate the possibility of core uncover. Also, SMART adopts inherent safety improving features and passive engineered safety systems such as the substantially large negative moderator temperature coefficients, passive residual heat removal system, emergency core cooling system, and a steel-made leak-tight Safeguard Vessel (SV) housing the RPV. This paper presents the results of the safety analyses using a MARS/SMR code for the instantaneous guillotine ruptures of the major pipelines penetrating the RPV. The analysis results, employing conservative initial/boundary conditions and assumptions, show that the safety systems of the SMART basic design adequately remove the core decay heat without causing core uncover for all the cases of the Small Break Loss of Coolant Accidents (SBLOCAs). The sensitivity study results with variable SV conditions show that the reduced SV net free volume can shorten the time for reaching the thermal and mechanical equilibrium condition between the RPV and SV. Under these boundary conditions, the primary system inventory loss can be minimized and the core remains covered for a longer period of time without any makeup of the coolant. (authors)

  12. Evaluation of Heat Losses Behind the Front of the Detonation Moving Along the Metallic Porous Surface

    Directory of Open Access Journals (Sweden)

    S. V. Golovastov

    2016-01-01

    Full Text Available The paper considers a computational technique of the heat flow from the hot products of detonation combustion into the porous coating and estimates the efficiency of the coating layer that results in slowing the flame front down with disregard the transverse displacement of the combustion products weight of a hydrogen-air mixture.Initial thermodynamic parameters of combustion products on the porous coating surface have been estimated. A drag (stagnation temperature of flow was determined.The statement of task was to calculate the heat flow into the long cylindrical metal fiber with radius of 15 μm. The reference values of heat capacity and heat diffusivity were used to estimate a thermal diffusivity in a wide range of temperatures. An approximation of the parameters is given for a wide range of temperatures.The calculation algorithm using an explicit four-point scheme is presented. The convergence and accuracy of the results were confirmed. The theoretical estimation using cylindrical Bessel functions was made to prove the accuracy of the results.Total heat loss was estimated using the photos of moving detonation front and hot combustion gases.Comparison of the total heat loss and the amount of energy absorbed by a single fiber allowed us to find that the porous coating thickness, resulting in attenuation of detonation wave, is efficient.

  13. Modeling and simulation of loss of the ultimate heat sink in a typical material testing reactor

    International Nuclear Information System (INIS)

    El-Khatib, Hisham; El-Morshedy, Salah El-Din; Higazy, Maher G.; El-Shazly, Karam

    2013-01-01

    Highlights: ► A thermal–hydraulic model has been developed to simulate loss of the ultimate heat sink in MTR. ► The model involves three coupled sub-models for core, heat exchanger and cooling tower. ► The model is validated against PARET for steady-state and verified by operation data for transients. ► The model is used to simulate the behavior of the reactor under a loss of the ultimate heat sink. ► The model results are analyzed and discussed. -- Abstract: A thermal–hydraulic model has been developed to simulate loss of the ultimate heat sink in a typical material testing reactor (MTR). The model involves three interactively coupled sub-models for reactor core, heat exchanger and cooling tower. The model is validated against PARET code for steady-state operation and verified by the reactor operation records for transients. Then, the model is used to simulate the thermal–hydraulic behavior of the reactor under a loss of the ultimate heat sink event. The simulation is performed for two operation regimes: regime I representing 11 MW power and three cooling tower cells operated, and regime II representing 22 MW power and six cooling tower cells operated. In regime I, the simulation is performed for 1, 2 and 3 cooling tower cells failed while in regime II, it is performed for 1, 2, 3, 4, 5 and 6 cooling tower cells failed. The simulation is performed under protected conditions where the safety action called power reduction is triggered by reactor protection system to decrease the reactor power by 20% when the coolant inlet temperature to the core reaches 43 °C and scram is triggered if the core inlet temperature reaches 44 °C. The model results are analyzed and discussed.

  14. Ruminant Nutrition Symposium: ruminant production and metabolic responses to heat stress.

    Science.gov (United States)

    Baumgard, L H; Rhoads, R P

    2012-06-01

    Heat stress compromises efficient animal production by marginalizing nutrition, management, and genetic selection efforts to maximize performance endpoints. Modifying farm infrastructure has yielded modest success in mitigating heat stress-related losses, yet poor production during the summer remains arguably the costliest issue facing livestock producers. Reduced output (e.g., milk yield and muscle growth) during heat stress was traditionally thought to result from decreased nutrient intake (i.e., a classic biological response shared by all animals during environmental-induced hyperthermia). Our recent observations have begun to challenge this belief and indicate heat-stressed animals employ novel homeorhetic strategies to direct metabolic and fuel selection priorities independently of nutrient intake or energy balance. Alterations in systemic physiology support a shift in carbohydrate metabolism, evident by increased basal and stimulated circulating insulin concentrations. Perhaps most intriguing given the energetic shortfall of the heat-stressed animal is the apparent lack of basal adipose tissue mobilization coupled with a reduced responsiveness to lipolytic stimuli. Thus, the heat stress response markedly alters postabsorptive carbohydrate, lipid, and protein metabolism independently of reduced feed intake through coordinated changes in fuel supply and utilization by multiple tissues. Interestingly, the systemic, cellular, and molecular changes appear conserved amongst different species and physiological states. Ultimately, these changes result in the reprioritization of fuel selection during heat stress, which appears to be primarily responsible for reduced ruminant animal productivity during the warm summer months.

  15. Pressure loss characteristics of LSTF steam generator heat-transfer tubes. Pressure loss increase due to tube internal instruments

    International Nuclear Information System (INIS)

    Suzuki, Mitsuhiro

    1994-11-01

    The steam generator of the Large-Scale Test Facility (LSTF) includes 141 heat-transfer U-tubes with different lengths. Six U-tubes among them are furnished with 15 or 17 probe-type instruments (conduction probe with a thermocouple; CPT) protuberant into the primary side of the U-tubes. Other 135 U-tubes are not instrumented. This results in different hydraulic conditions between the instrumented and non-instrumented U-tubes with the same length. A series of pressure loss characteristics tests was conducted at a test apparatus simulating both types of U-tube. The following pressure loss coefficient (K CPT ) was reduced as a function of Reynolds number (Re) from these tests under single-phase water flow conditions. K CPT =0.16 5600≤Re≤52820, K CPT =60.66xRe -0.688 2420≤Re≤5600, K CPT =2.664x10 6 Re -2.06 1371≤Re≤2420. The maximum uncertainty is 22%. By using these results, the total pressure loss coefficients of full length U-tubes were estimated. It is clarified that the total pressure loss of the shortest instrumented U-tube is equivalent to that of the middle-length non-instrumented U-tube and also that a middle-length instrumented U-tube is equivalent to the longest non-instrumented U-tube. Concludingly. it is important to take account of the CPT pressure loss mentioned above in estimation of fluid behavior at the non-instrumented U-tubes either by using the LSTF experiment data from the CPT-installed U-tubes or by using any analytical codes. (author)

  16. Energy reduction in buildings in temperate and tropic regions utilizing a heat loss measuring device

    DEFF Research Database (Denmark)

    Sørensen, Lars Schiøtt

    2012-01-01

    There exist two ordinary ways to obtain global energy efficiency. One way is to make improvements on the energy production and supply side, and the other way is, in general, to reduce the consume of energy in the society. This paper has focus on the latter and especially the consume of energy...... for heating up, and cooling down our houses. There is a huge energy saving potential on this area reducing both the World climate problems and economy challenges as well. Heating of buildings in Denmark counts for approximately 40% of the entire national energy consume. Of this reason a reduction of heat...... losses from building envelopes are of great impor­tance in order to reach the Bologna CO2-emission reduction goals. Energy renovation of buildings is a topic of huge focus around the world these years. Not only expenses for heating in the tempered and arctic regions are of importance, but also expenses...

  17. Application of dynamic response analysis to JET heat pulse data

    International Nuclear Information System (INIS)

    Griguoli, A.; Sips, A.C.C.

    1993-09-01

    The plasma dynamic response can be used to study transport processes in a tokamak plasma. A method has been developed for the application of dynamic response analysis to study perturbations away from the plasma equilibrium. In this report perturbations on the electron temperature following a sawtooth collapse in the center of the plasma are considered. The method has been used to find mathematical description of a series of heat pulses at the Joint European Torus project (JET). From the plasma dynamic response, the time constants which characterise the heat pulse are obtained. These time constants are compared to the transport coefficients found in previous analysis of the JET heat pulse data. Various methods are discussed for applying dynamic response analysis to JET heat pulse data. (author)

  18. Comparing heat flow models for interpretation of precast quadratic pile heat exchanger thermal response tests

    DEFF Research Database (Denmark)

    Alberdi Pagola, Maria; Poulsen, Søren Erbs; Loveridge, Fleur

    2018-01-01

    This paper investigates the applicability of currently available analytical, empirical and numerical heat flow models for interpreting thermal response tests (TRT) of quadratic cross section precast pile heat exchangers. A 3D finite element model (FEM) is utilised for interpreting five TRTs by in...

  19. Smart electric storage heating and potential for residential demand response

    OpenAIRE

    Darby, S

    2017-01-01

    Low-carbon transition plans for temperate and sub-polar regions typically involve some electrification of space heating. This poses challenges to electricity system operation and market design, as it increases overall demand and alters the temporal patterns of that demand. One response to the challenge is to ‘smarten’ electrical heating, enabling it to respond to network conditions by storing energy at times of plentiful supply, releasing it in response to customer demands and offering rapid-...

  20. How robust is the atmospheric circulation response to Arctic sea-ice loss in isolation?

    Science.gov (United States)

    Kushner, P. J.; Hay, S. E.; Blackport, R.; McCusker, K. E.; Oudar, T.

    2017-12-01

    It is now apparent that active dynamical coupling between the ocean and atmosphere determines a good deal of how Arctic sea-ice loss changes the large-scale atmospheric circulation. In coupled ocean-atmosphere models, Arctic sea-ice loss indirectly induces a 'mini' global warming and circulation changes that extend into the tropics and the Southern Hemisphere. Ocean-atmosphere coupling also amplifies by about 50% Arctic free-tropospheric warming arising from sea-ice loss (Deser et al. 2015, 2016). The mechanisms at work and how to separate the response to sea-ice loss from the rest of the global warming process remain poorly understood. Different studies have used distinctive numerical approaches and coupled ocean-atmosphere models to address this problem. We put these studies on comparable footing using pattern scaling (Blackport and Kushner 2017) to separately estimate the part of the circulation response that scales with sea-ice loss in the absence of low-latitude warming from the part that scales with low-latitude warming in the absence of sea-ice loss. We consider well-sampled simulations from three different coupled ocean-atmosphere models (CESM1, CanESM2, CNRM-CM5), in which greenhouse warming and sea-ice loss are driven in different ways (sea ice albedo reduction/transient RCP8.5 forcing for CESM1, nudged sea ice/CO2 doubling for CanESM2, heat-flux forcing/constant RCP8.5-derived forcing for CNRM-CM5). Across these different simulations, surprisingly robust influences of Arctic sea-ice loss on atmospheric circulation can be diagnosed using pattern scaling. For boreal winter, the isolated sea-ice loss effect acts to increase warming in the North American Sub-Arctic, decrease warming of the Eurasian continent, enhance precipitation over the west coast of North America, and strengthen the Aleutian Low and the Siberian High. We will also discuss how Arctic free tropospheric warming might be enhanced via midlatitude ocean surface warming induced by sea-ice loss

  1. Heat loss in air of an Antarctic marine mammal, the Weddell seal.

    Science.gov (United States)

    Mellish, Jo-Ann; Hindle, Allyson; Skinner, John; Horning, Markus

    2015-01-01

    The conflicting needs of homeostasis in air versus water complicate our understanding of thermoregulation in marine mammals. Large-scale modeling efforts directed at predicting the energetic impact of changing sea ice conditions on polar ecosystems require a better understanding of thermoregulation in air of free-ranging animals. We utilized infrared imaging as an indirect approach to determine surface temperatures of dry, hauled-out Weddell seals (Leptonychotes weddellii, n = 35) of varying age and body condition during the Antarctic summer. The study groups provided a fivefold range in body mass and a threefold range in blubber depth. Surface temperature (T s) did not vary by body region (head, shoulder, axilla, torso, hip, flippers). Average seal T s (mean 13.9 ± 11.2 °C) was best described through a combination of the physical traits of body mass and environmental variables of ambient temperature T air, and wind speed. Additional factors of ice temperature (T ice), relative humidity and cloud cover did not improve the model. Heat transfer model estimates suggested that radiation contributed 56.6 ± 7.7 % of total heat loss. Convection and conduction accounted for the remaining 15.7 ± 12.3 and 27.7 ± 9.3 %, respectively. Heat loss by radiation was primarily influenced by body mass and wind speed, whereas convective heat loss was influenced primarily by blubber depth and wind speed. Conductive heat loss was modeled largely as a function of physical traits of mass and blubber depth rather than any environmental covariates, and therefore was substantially higher in animals in leaner condition.

  2. Quantifying global soil carbon losses in response to warming.

    Science.gov (United States)

    Crowther, T W; Todd-Brown, K E O; Rowe, C W; Wieder, W R; Carey, J C; Machmuller, M B; Snoek, B L; Fang, S; Zhou, G; Allison, S D; Blair, J M; Bridgham, S D; Burton, A J; Carrillo, Y; Reich, P B; Clark, J S; Classen, A T; Dijkstra, F A; Elberling, B; Emmett, B A; Estiarte, M; Frey, S D; Guo, J; Harte, J; Jiang, L; Johnson, B R; Kröel-Dulay, G; Larsen, K S; Laudon, H; Lavallee, J M; Luo, Y; Lupascu, M; Ma, L N; Marhan, S; Michelsen, A; Mohan, J; Niu, S; Pendall, E; Peñuelas, J; Pfeifer-Meister, L; Poll, C; Reinsch, S; Reynolds, L L; Schmidt, I K; Sistla, S; Sokol, N W; Templer, P H; Treseder, K K; Welker, J M; Bradford, M A

    2016-11-30

    The majority of the Earth's terrestrial carbon is stored in the soil. If anthropogenic warming stimulates the loss of this carbon to the atmosphere, it could drive further planetary warming. Despite evidence that warming enhances carbon fluxes to and from the soil, the net global balance between these responses remains uncertain. Here we present a comprehensive analysis of warming-induced changes in soil carbon stocks by assembling data from 49 field experiments located across North America, Europe and Asia. We find that the effects of warming are contingent on the size of the initial soil carbon stock, with considerable losses occurring in high-latitude areas. By extrapolating this empirical relationship to the global scale, we provide estimates of soil carbon sensitivity to warming that may help to constrain Earth system model projections. Our empirical relationship suggests that global soil carbon stocks in the upper soil horizons will fall by 30 ± 30 petagrams of carbon to 203 ± 161 petagrams of carbon under one degree of warming, depending on the rate at which the effects of warming are realized. Under the conservative assumption that the response of soil carbon to warming occurs within a year, a business-as-usual climate scenario would drive the loss of 55 ± 50 petagrams of carbon from the upper soil horizons by 2050. This value is around 12-17 per cent of the expected anthropogenic emissions over this period. Despite the considerable uncertainty in our estimates, the direction of the global soil carbon response is consistent across all scenarios. This provides strong empirical support for the idea that rising temperatures will stimulate the net loss of soil carbon to the atmosphere, driving a positive land carbon-climate feedback that could accelerate climate change.

  3. Effect of energetic ion loss on ICRF heating efficiency and energy confinement time in heliotrons

    International Nuclear Information System (INIS)

    Murakami, S.; Nakajima, N.; Okamoto, M.; Nuehrenberg, J.

    1999-01-01

    The ICRF heating efficiency and the global energy confinement time during ICRF heating are investigated, including the effect of energetic ion loss in heliotrons. The approximate formula of ICRF heating efficiency is derived using results based on Monte Carlo simulations (Murakami, S., et al., Fusion Eng. Des. 26 (1995) 209). The global energy confinement time including the energetic ion effect can be expressed in heliotrons in terms of ICRF heating power, plasma density and magnetic field strength. Results in plasmas at CHS show a systematic decrease of the global energy confinement time due to energetic ion loss from the assumed energy confinement scaling law, which is consistent with the experimental observations. The model is also applied to ICRF minority heating in LHD plasmas in two cases of typical magnetic configurations. A clear increase of the global energy confinement time due to the stored energy of energetic tail ions is obtained in the 'orbit improved' configuration, while a decrease is observed in the 'standard' configuration. (author)

  4. Oxidative stress impairs the heat stress response and delays unfolded protein recovery.

    Directory of Open Access Journals (Sweden)

    Masaaki Adachi

    2009-11-01

    Full Text Available Environmental changes, air pollution and ozone depletion are increasing oxidative stress, and global warming threatens health by heat stress. We now face a high risk of simultaneous exposure to heat and oxidative stress. However, there have been few studies investigating their combined adverse effects on cell viability.Pretreatment of hydrogen peroxide (H(2O(2 specifically and highly sensitized cells to heat stress, and enhanced loss of mitochondrial membrane potential. H(2O(2 exposure impaired the HSP40/HSP70 induction as heat shock response (HSR and the unfolded protein recovery, and enhanced eIF2alpha phosphorylation and/or XBP1 splicing, land marks of ER stress. These H(2O(2-mediated effects mimicked enhanced heat sensitivity in HSF1 knockdown or knockout cells. Importantly, thermal preconditioning blocked H(2O(2-mediated inhibitory effects on refolding activity and rescued HSF1 +/+ MEFs, but neither blocked the effects nor rescued HSF1 -/- MEFs. These data strongly suggest that inhibition of HSR and refolding activity is crucial for H(2O(2-mediated enhanced heat sensitivity.H(2O(2 blocks HSR and refolding activity under heat stress, thereby leading to insufficient quality control and enhancing ER stress. These uncontrolled stress responses may enhance cell death. Our data thus highlight oxidative stress as a crucial factor affecting heat tolerance.

  5. ANALYSIS OF THERMAL PROPERTIES AND HEAT LOSS IN CONSTRUCTION AND ISOTHERMAL MATERIALS OF MULTILAYER BUILDING WALLS

    Directory of Open Access Journals (Sweden)

    Arkadiusz Urzędowski

    2017-06-01

    Full Text Available The article discusses the impact of vertical partition, technology on thermal insulation of the building, and the resulting savings and residents thermal comfort. The study is carried out as an analysis of three selected design solutions including such materials as: aerated concrete elements, polystyrene, ceramic elements, concrete, mineral plaster. Simulation results of heat transfer in a multi-layered wall, are subjected to detailed analysis by means of thermal visual methods. The study of existing structures, helped to identify the local point of heat loss by means of infrared technology leading to determination of U-value reduction by 36% in maximum for the described 3 types of structure.

  6. Probabilistic analysis of the loss of the decay heat removal function for Creys-Malville reactor

    International Nuclear Information System (INIS)

    Lanore, J.M.; Villeroux-Lombard, C.; Bouscatie, F.; Pavret de la Rochefordiere, A.

    1982-01-01

    The classical fault tree/event tree methods do not take into account the dependence in time of the systems behaviour during the sequences, and that is quite unrealistic for the decay heat removal function. It was then necessary to use a new methodology based on functional states of the whole system and on transition laws between these states. Thus, the probabilistic analysis of the decay heat removal function for Creys-Malville plant is performed in a global way. The main accident sequences leading to the loss of the function are then determined a posteriori. The weak points are pointed out, in particular the importance of common mode failures

  7. Hawking's Israel boycott sparks heated response

    Science.gov (United States)

    Dacey, James

    2013-06-01

    The controversial decision by Stephen Hawking to boycott a prominent conference in Jerusalem in protest against the policies of the Israeli government has provoked strong responses from academics and commentators.

  8. Heat shock response improves heterologous protein secretion in Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Hou, Jin; Österlund, Tobias; Liu, Zihe

    2013-01-01

    The yeast Saccharomyces cerevisiae is a widely used platform for the production of heterologous proteins of medical or industrial interest. However, heterologous protein productivity is often low due to limitations of the host strain. Heat shock response (HSR) is an inducible, global, cellular...... stress response, which facilitates the cell recovery from many forms of stress, e.g., heat stress. In S. cerevisiae, HSR is regulated mainly by the transcription factor heat shock factor (Hsf1p) and many of its targets are genes coding for molecular chaperones that promote protein folding and prevent...... the accumulation of mis-folded or aggregated proteins. In this work, we over-expressed a mutant HSF1 gene HSF1-R206S which can constitutively activate HSR, so the heat shock response was induced at different levels, and we studied the impact of HSR on heterologous protein secretion. We found that moderate and high...

  9. Fast pyrobolometers for measurements of plasma heat fluxes and radiation losses in the MST Reversed Field Pinch

    International Nuclear Information System (INIS)

    Fiksel, G.; Frank, J.; Holly, D.

    1993-01-01

    Two types of fast bolometers are described for the plasma energy transport study in the Madison Symmetric Torus plasma confinement device. Both types use pyrocrystals of LiTaO 3 or LiNbO 3 as the sensors. One type is used for measurements of the radiated heat losses and is situated at the vacuum shell inner surface. Another type is insertable in the plasma and measures the plasma particle heat flux. The frequency response of the bolometers is measured to be in the 150--200 kHz range. The range of the measured power fluxes is 0.1 W/cm 2 10 kW/cm 2 and can be adjusted by changing the size of the entrance aperture. The lower limit is determined by the amplifier noise and the frequency bandwidth, the higher limit by destruction of the bolometer sensor

  10. Mode and climatic factors effect on energy losses in transient heat modes of transmission lines

    Science.gov (United States)

    Bigun, A. Ya; Sidorov, O. A.; Osipov, D. S.; Girshin, S. S.; Goryunov, V. N.; Petrova, E. V.

    2018-01-01

    Electrical energy losses increase in modern grids. The losses are connected with an increase in consumption. Existing models of electric power losses estimation considering climatic factors do not allow estimating the cable temperature in real time. Considering weather and mode factors in real time allows to meet effectively and safely the consumer’s needs to minimize energy losses during transmission, to use electric power equipment effectively. These factors increase an interest in the evaluation of the dynamic thermal mode of overhead transmission lines conductors. The article discusses an approximate analytic solution of the heat balance equation in the transient operation mode of overhead lines based on the least squares method. The accuracy of the results obtained is comparable with the results of solving the heat balance equation of transient thermal mode with the Runge-Kutt method. The analysis of mode and climatic factors effect on the cable temperature in a dynamic thermal mode is presented. The calculation of the maximum permissible current for variation of weather conditions is made. The average electric energy losses during the transient process are calculated with the change of wind, air temperature and solar radiation. The parameters having the greatest effect on the transmission capacity are identified.

  11. Oscillating-flow loss test results in rectangular heat exchanger passages

    Science.gov (United States)

    Wood, J. Gary

    1991-01-01

    Test results of oscillating flow losses in rectangular heat exchanger passages of various aspect ratios are given. This work was performed in support of the design of a free-piston Stirling engine (FPSE) for a dynamic space power conversion system. Oscillating flow loss testing was performed using an oscillating flow rig, which was based on a variable stroke and variable frequency linear drive motor. Tests were run over a range of oscillating flow parameters encompassing the flow regimes of the proposed engine design. Test results are presented in both tabular and graphical form and are compared against analytical predictions.

  12. Dynamic Response Testing in an Electrically Heated Reactor Test Facility

    Science.gov (United States)

    Bragg-Sitton, Shannon M.; Morton, T. J.

    2006-01-01

    Non-nuclear testing can be a valuable tool in development of a space nuclear power or propulsion system. In a non-nuclear test bed, electric heaters are used to simulate the heat from nuclear fuel. Standard testing allows one to fully assess thermal, heat transfer, and stress related attributes of a given system, but fails to demonstrate the dynamic response that would be present in an integrated, fueled reactor system. The integration of thermal hydraulic hardware tests with simulated neutronic response provides a bridge between electrically heated testing and full nuclear testing. By implementing a neutronic response model to simulate the dynamic response that would be expected in a fueled reactor system, one can better understand system integration issues, characterize integrated system response times and response characteristics, and assess potential design improvements at a relatively small fiscal investment. Initial system dynamic response testing was demonstrated on the integrated SAFE-100a heat pipe cooled, electrically heated reactor and heat exchanger hardware, utilizing a one-group solution to the point kinetics equations to simulate the expected neutronic response of the system (Bragg-Sitton, 2005). The current paper applies the same testing methodology to a direct drive gas cooled reactor system, demonstrating the applicability of the testing methodology to any reactor type and demonstrating the variation in system response characteristics in different reactor concepts. In each testing application, core power transients were controlled by a point kinetics model with reactivity feedback based on core average temperature; the neutron generation time and the temperature feedback coefficient are provided as model inputs. Although both system designs utilize a fast spectrum reactor, the method of cooling the reactor differs significantly, leading to a variable system response that can be demonstrated and assessed in a non-nuclear test facility.

  13. Heat Loss Testing of Schott's 2008 PTR70 Parabolic Trough Receiver

    Energy Technology Data Exchange (ETDEWEB)

    Burkholder, Frank [National Renewable Energy Lab. (NREL), Golden, CO (United States); Kutscher, Chuck [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2009-05-01

    Two Schott 2008 model year PTR70 HCEs were tested on NREL's heat loss test stand from 100 - 500 deg C in 50 deg C increments. Absorber emittance was determined from the laboratory testing so that the performance of the HCEs could be modeled in a parabolic trough collector. Collector/HCE simulation results for many different field operation conditions were used to create heat loss correlationcoefficients for Excelergy and SAM. SAM estimates that the decreased emittance of the 2008 PTR70 will decrease the LCOE for parabolic trough power plants by 0.5 cents/kWh and increase the electricity generated by 5% relative to previous PTR70s. These conclusions assume that the 2008 PTR70 is supplied at the same cost and with the same optical performance as earlier PTR70 models.

  14. Monitoring the risk of loss of heat sink during plant shutdowns at Bruce Generating Station 'A'

    International Nuclear Information System (INIS)

    Krishnan, K.S.; Mancuso, F.; Vecchiarelli, D.

    1996-01-01

    A relatively simple loss of shutdown heat sink fault tree model has been developed and used during unit outages at Bruce Nuclear Generation Station 'A' to assess, from a risk and reliability perspective, alternative heat sink strategies and to aid in decisions on allowable outage configurations. The model is adjusted to reflect the various unit configurations planned during a specific outage, and identifies events and event combinations leading to loss of fuel cooling. The calculated failure frequencies are compared to the limits consistent with corporate and international public safety goals. The importance measures generated by the interrogation of the fault tree model for each outage configuration are also used to reschedule configurations with high fuel damage frequency later into the outage and to control the configurations with relatively high probability of fuel damage to short intervals at the most appropriate time into the outage. (author)

  15. The influence of soil moisture in the unsaturated zone on the heat loss from buildings via the ground

    NARCIS (Netherlands)

    Janssen, H.; Carmeliet, J.; Hens, H.

    2002-01-01

    In calculations of building heat loss via the ground, the coupling with soil moisture transfer is generally ignored, an important hypothesis which will be falsified in this paper. Results from coupled simulations - coupled soil heat and moisture transfer equations and complete surface heat and

  16. Heat deposition on the first wall due to ICRF-induced loss of fast ions in JT-60U

    International Nuclear Information System (INIS)

    Kusama, Y.; Tobita, K.; Kimura, H.; Hamamatsu, K.; Fujii, T.; Nemoto, M.; Saigusa, M.; Moriyama, S.; Tani, K.; Koide, Y.; Sakasai, A.; Nishitani, T.; Ushigusa, K.

    1995-01-01

    In JT-60U, the heat deposition on the first wall due to the ICRF-induced loss of fast ions was investigated by changing the position of the resonance layer in the ripple-trapping region. A heat spot appears on the first wall of the same major radius as the resonance layer of the ICRF waves. The broadening of the heat spot in the major radius direction is consistent with that of the resonance layer due to the Doppler broadening. The heat spot is considered to be formed by the ICRF-induced ripple-trapped loss of fast ions. Although the total ICRF-induced loss power to the heat spot is as low as 2% of the total ICRF power, the additional heat flux will become a new issue because of the localized heat deposition on the first wall. ((orig.))

  17. Method for reducing heat loss during injection of hot water into an oil stratum

    Energy Technology Data Exchange (ETDEWEB)

    Evgenev, A E; Kalashnikov, V N; Raiskii, Yu D

    1968-07-01

    A method is described for reduction of heat loss during the injection of hot water into an oil stratum. During the transportation of the hot water to the face of the bore holes, it has high-molecular polymers added to it. The high-molecular polymer may be guanidine or polyoxyethylene in the quantity of 0.01 to 0.03% by wt.

  18. Early weight loss predicts weight loss treatment response regardless of binge-eating disorder status and pretreatment weight change.

    Science.gov (United States)

    Barnes, Rachel D; Ivezaj, Valentina; Pittman, Brian P; Grilo, Carlos M

    2018-04-10

    Individuals seeking weight loss treatment have diverse pretreatment weight trajectories, and once enrolled, individuals' response to weight loss treatments also varies greatly and may be influenced by the presence of binge-eating disorder (BED). Reported average weight losses may obscure these considerable differences. This study examined whether BED status and different weight-related change variables are associated with successful weight loss treatment outcomes in a controlled treatment study. Participants (N = 89) with overweight/obesity, with and without BED, participated in a 3-month weight loss trial in primary care with 3- and 12-month follow-ups. We tested the prognostic significance of four weight-related change variables (the last supper, early weight loss, pretreatment weight trajectory, weight suppression) on outcomes (weight loss-overall, weight loss-"subsequent," weight loss during second half of treatment). Early weight loss was positively associated with weight loss-overall at post-treatment, and at 3-month and 12-month follow-up. Early weight loss was positively associated with weight loss-subsequent at post-treatment only. No other weight-related variables were significantly associated with weight loss. Models including BED status and treatment condition were not significant. Participants with early weight loss were more likely to continue losing weight, regardless of BED status or treatment condition. The results highlight the importance of early dedication to weight loss treatment to increase the likelihood of positive outcomes. © 2018 Wiley Periodicals, Inc.

  19. Finite time thermodynamic analysis and optimization of solar-dish Stirling heat engine with regenerative losses

    Directory of Open Access Journals (Sweden)

    Sharma Arjun

    2011-01-01

    Full Text Available The present study investigates the performance of the solar-driven Stirling engine system to maximize the power output and thermal efficiency using the non-linearized heat loss model of the solar dish collector and the irreversible cycle model of the Stirling engine. Finite time thermodynamic analysis has been done for combined system to calculate the finite-rate heat transfer, internal heat losses in the regenerator, conductive thermal bridging losses and finite regeneration process time. The results indicate that exergy efficiency of dish system increases as the effectiveness of regenerator increases but decreases with increase in regenerative time coefficient. It is also found that optimal range of collector temperature and corresponding concentrating ratio are 1000 K~1400 K and 1100~1400, respectively in order to get maximum value of exergy efficiency. It is reported that the exergy efficiency of this dish system can reach the maximum value when operating temperature and concentrating ratio are 1150 K and 1300, respectively.

  20. Radiation losses and global energy balance for Ohmically heated discharges in ASDEX

    International Nuclear Information System (INIS)

    Mueller, E.R.; Behringer, K.; Niedermeyer, H.

    1982-01-01

    Global energy balance, radiation profiles and dominant impurity radiation sources are compared for Ohmically heated limiter and divertor discharges in the ASDEX tokamak. In discharges with a poloidal stainless-steel limiter, total radiation from the plasma is the dominant energy loss channel. The axisymmetric divertor reduces this volume-integrated radiation to 30-35% of the heating power and additional Ti-gettering halves it again to 10-15%. Local radiation losses in the plasma centre, which are mainly due to the presence of iron impurity ions, are reduced by about one order of magnitude. In high-current (Isub(p) = 400 kA) and high-density (nsub(e)-bar = 6 x 10 13 cm -3 ) ungettered divertor discharges, up to 55% of the heating power is dumped into a cold-gas target inside the divertor chambers. The bolometrically detected volume power losses in the chambers can mainly be attributed to neutral hydrogen atoms with kinetic energies of a few eV. In this parameter range, the divertor plasma is dominated by inelastic molecular and atomic processes, the main process being Franck-Condon dissociation of H 2 molecules. (author)

  1. Superconductor design and loss analysis for a 20 MJ induction heating coil

    International Nuclear Information System (INIS)

    Walker, M.S.; Declercq, J.G.; Zeitlin, B.A.

    1980-01-01

    The design of a 50 k Ampere conductor for use in a 20 MJ Induction Heating Coil is described. The conductor is a wide flat cable of 36 subcables, each of which contains six NbTi strands around a stainless steel core strand. The 2.04 mm (0.080'') diameter monolithic strands allow bubble clearing for cryostable operation at a pool boiling heat transfer from the unoccluded strand surface of 0.26 Watts/cm 2 . A thin, tough polyester amide-imide (Westinghouse Omega) insulation provides a rugged coating that will resist flaking and chipping during the cabling and compaction operations and provide (1) a reliable adherent surface for enhanced heat transfer, and (2) a low voltage standoff preventing interstrand coupling losses. The strands are uniquely configured using CuNi elements to provide low ac losses with NbTi filaments in an all-copper matrix. AC losses are expected to be approximately 0.3% of 20 MJ for a -7.5 T to 7.5 T one-second 1/2-cosinusoidal bipolar operation in a 20 MJ coil. They will be approximately 0.1% of 100 MJ for 1.8 second -8 T and +8 T ramped operation in a 100 MJ coil. The design is firmly based on the results of tests performed on prototype strands and subcables

  2. Using Solar Hot Water to Address Piping Heat Losses in Multifamily Buildings

    Energy Technology Data Exchange (ETDEWEB)

    Springer, David [Alliance for Residential Building Innovation, Davis, CA (United States); Seitzler, Matt [Alliance for Residential Building Innovation, Davis, CA (United States); Backman, Christine [Alliance for Residential Building Innovation, Davis, CA (United States); Weitzel, Elizabeth [Alliance for Residential Building Innovation, Davis, CA (United States)

    2015-10-01

    Solar thermal water heating is most cost effective when applied to multifamily buildings and some states offer incentives or other inducements to install them. However, typical solar water heating designs do not allow the solar generated heat to be applied to recirculation losses, only to reduce the amount of gas or electric energy needed for hot water that is delivered to the fixtures. For good reasons, hot water that is recirculated through the building is returned to the water heater, not to the solar storage tank. The project described in this report investigated the effectiveness of using automatic valves to divert water that is normally returned through the recirculation piping to the gas or electric water heater instead to the solar storage tank. The valves can be controlled so that the flow is only diverted when the returning water is cooler than the water in the solar storage tank.

  3. Hypocretin/orexin loss changes the hypothalamic immune response.

    Science.gov (United States)

    Tanaka, Susumu; Takizawa, Nae; Honda, Yoshiko; Koike, Taro; Oe, Souichi; Toyoda, Hiromi; Kodama, Tohru; Yamada, Hisao

    2016-10-01

    Hypocretin, also known as orexin, maintains the vigilance state and regulates various physiological processes, such as arousal, sleep, food intake, energy expenditure, and reward. Previously, we found that when wild-type mice and hypocretin/ataxin-3 littermates (which are depleted of hypothalamic hypocretin-expressing neurons postnatally) were administered lipopolysaccharide (LPS), the two genotypes exhibited significant differences in their sleep/wake cycle, including differences in the degree of increase in sleep periods and in recovery from sickness behaviour. In the present study, we examined changes in the hypothalamic vigilance system and in the hypothalamic expression of inflammatory factors in response to LPS in hypocretin/ataxin-3 mice. Peripheral immune challenge with LPS affected the hypothalamic immune response and vigilance states. This response was altered by the loss of hypocretin. Hypocretin expression was inhibited after LPS injection in both hypocretin/ataxin-3 mice and their wild-type littermates, but expression was completely abolished only in hypocretin/ataxin-3 mice. Increases in the number of histidine decarboxylase (HDC)-positive cells and in Hdc mRNA expression were found in hypocretin/ataxin-3 mice, and this increase was suppressed by LPS. Hypocretin loss did not impact the change in expression of hypothalamic inflammatory factors in response to LPS, except for interferon gamma and colony stimulating factor 3. The number of c-Fos-positive/HDC-positive cells in hypocretin/ataxin-3 mice administered LPS injections was elevated, even during the rest period, in all areas, suggesting that there is an increase in the activity of histaminergic neurons in hypocretin/ataxin-3 mice following LPS injection. Taken together, our results suggest a novel role for hypocretin in the hypothalamic response to peripheral immune challenge. Our findings contribute to the understanding of the pathophysiology of narcolepsy. Copyright © 2016 Elsevier Inc. All

  4. Endoreversible quantum heat engines in the linear response regime.

    Science.gov (United States)

    Wang, Honghui; He, Jizhou; Wang, Jianhui

    2017-07-01

    We analyze general models of quantum heat engines operating a cycle of two adiabatic and two isothermal processes. We use the quantum master equation for a system to describe heat transfer current during a thermodynamic process in contact with a heat reservoir, with no use of phenomenological thermal conduction. We apply the endoreversibility description to such engine models working in the linear response regime and derive expressions of the efficiency and the power. By analyzing the entropy production rate along a single cycle, we identify the thermodynamic flux and force that a linear relation connects. From maximizing the power output, we find that such heat engines satisfy the tight-coupling condition and the efficiency at maximum power agrees with the Curzon-Ahlborn efficiency known as the upper bound in the linear response regime.

  5. Proteomics analysis of alfalfa response to heat stress.

    Directory of Open Access Journals (Sweden)

    Weimin Li

    Full Text Available The proteome responses to heat stress have not been well understood. In this study, alfalfa (Medicago sativa L. cv. Huaiyin seedlings were exposed to 25 °C (control and 40 °C (heat stress in growth chambers, and leaves were collected at 24, 48 and 72 h after treatment, respectively. The morphological, physiological and proteomic processes were negatively affected under heat stress. Proteins were extracted and separated by two-dimensional polyacrylamide gel electrophoresis (2-DE, and differentially expressed protein spots were identified by mass spectrometry (MS. Totally, 81 differentially expressed proteins were identified successfully by MALDI-TOF/TOF. These proteins were categorized into nine classes: including metabolism, energy, protein synthesis, protein destination/storage, transporters, intracellular traffic, cell structure, signal transduction and disease/defence. Five proteins were further analyzed for mRNA levels. The results of the proteomics analyses provide a better understanding of the molecular basis of heat-stress responses in alfalfa.

  6. Hormonal modulation of the heat shock response: insights from fish with divergent cortisol stress responses

    DEFF Research Database (Denmark)

    LeBlanc, Sacha; Höglund, Erik; Gilmour, Kathleen M.

    2012-01-01

    shock response, we capitalized on two lines of rainbow trout specifically bred for their high (HR) and low (LR) cortisol response to stress. We predicted that LR fish, with a low cortisol but high catecholamine response to stress, would induce higher levels of HSPs after acute heat stress than HR trout....... We found that HR fish have significantly higher increases in both catecholamines and cortisol compared with LR fish, and LR fish had no appreciable stress hormone response to heat shock. This unexpected finding prevented further interpretation of the hormonal modulation of the heat shock response...

  7. A SIMPLE EXPERIMENTAL MODEL OF HEAT SHOCK RESPONSE IN RATS

    Directory of Open Access Journals (Sweden)

    Tufi Neder Meyer

    1998-10-01

    Full Text Available Objective: To obtain a simple model for the elicitation of the heat shock response in rats. Design: Laboratory study. Setting: University research laboratories. Sample: Seventy-nine adult male albino rats (weight range 200 g to 570 g. Procedures: Exposure to heat stress by heating animals in a warm bath for 5 min after their rectal temperatures reached 107.60 F (420 C. Liver and lung samples were collected for heat-shock protein 70 (HSP70 detection (Western analysis. Results: Western analysis was positive for HSP70 in the liver and in the lungs of heated animals. There was a temporal correlation between heating and HSP70 detection: it was strongest 1 day after heating and reduced afterwards. No heated animals died. Conclusion: These data show that heating rats in a warm (45o C bath, according to parameters set in this model, elicits efficiently the heat shock response.OBJETIVO: Obter um modelo simples para tentar esclarecer a resposta ao choque térmico em ratos. LOCAL: Laboratório de pesquisa da Universidade. MÉTODO: Amostra: 79 ratos albinos, adultos, entre 200g a 570g. Procedimentos: Exposição ao calor, em banho quente, por 5 minutos, após a temperatura retal chegar a 42 graus centigrados. Biópsias de fígado e pulmão foram obtidas para detectar a proteina 70 (HSP 70, pelo "Western blot". RESULTADOS: As análises foram positivas nos animais aquecidos, com uma correlação entre aquecimento e constatação da HSP 70. Foi mais elevada no primeiro dia e não houve óbitos nos animais aquecidos. CONCLUSÃO: Os ratos aquecidos a 45 graus centígrados respondem eficientemente ao choque térmico.

  8. Social comparison mediates chimpanzees' responses to loss, not frustration

    DEFF Research Database (Denmark)

    Hopper, Lydia M; Lambeth, Susan P; Schapiro, Steve

    2014-01-01

    Why do chimpanzees react when their partner gets a better deal than them? Do they note the inequity or do their responses reflect frustration in response to unattainable rewards? To tease apart inequity and contrast, we tested chimpanzees in a series of conditions that created loss through...... individual contrast, through inequity, or by both. Chimpanzees were tested in four social and two individual conditions in which they received food rewards in return for exchanging tokens with an experimenter. In conditions designed to create individual contrast, after completing an exchange, the chimpanzees...... were given a relatively less-preferred reward than the one they were previously shown. The chimpanzees' willingness to accept the less-preferred rewards was independent of previously offered foods in both the social and individual conditions. In conditions that created frustration through inequity...

  9. Artificial Neural Networks-Based Software for Measuring Heat Collection Rate and Heat Loss Coefficient of Water-in-Glass Evacuated Tube Solar Water Heaters

    Science.gov (United States)

    Liu, Zhijian; Liu, Kejun; Li, Hao; Zhang, Xinyu; Jin, Guangya; Cheng, Kewei

    2015-01-01

    Measurements of heat collection rate and heat loss coefficient are crucial for the evaluation of in service water-in-glass evacuated tube solar water heaters. However, conventional measurement requires expensive detection devices and undergoes a series of complicated procedures. To simplify the measurement and reduce the cost, software based on artificial neural networks for measuring heat collection rate and heat loss coefficient of water-in-glass evacuated tube solar water heaters was developed. Using multilayer feed-forward neural networks with back-propagation algorithm, we developed and tested our program on the basis of 915measuredsamples of water-in-glass evacuated tube solar water heaters. This artificial neural networks-based software program automatically obtained accurate heat collection rateand heat loss coefficient using simply "portable test instruments" acquired parameters, including tube length, number of tubes, tube center distance, heat water mass in tank, collector area, angle between tubes and ground and final temperature. Our results show that this software (on both personal computer and Android platforms) is efficient and convenient to predict the heat collection rate and heat loss coefficient due to it slow root mean square errors in prediction. The software now can be downloaded from http://t.cn/RLPKF08. PMID:26624613

  10. Artificial Neural Networks-Based Software for Measuring Heat Collection Rate and Heat Loss Coefficient of Water-in-Glass Evacuated Tube Solar Water Heaters.

    Science.gov (United States)

    Liu, Zhijian; Liu, Kejun; Li, Hao; Zhang, Xinyu; Jin, Guangya; Cheng, Kewei

    2015-01-01

    Measurements of heat collection rate and heat loss coefficient are crucial for the evaluation of in service water-in-glass evacuated tube solar water heaters. However, conventional measurement requires expensive detection devices and undergoes a series of complicated procedures. To simplify the measurement and reduce the cost, software based on artificial neural networks for measuring heat collection rate and heat loss coefficient of water-in-glass evacuated tube solar water heaters was developed. Using multilayer feed-forward neural networks with back-propagation algorithm, we developed and tested our program on the basis of 915 measured samples of water-in-glass evacuated tube solar water heaters. This artificial neural networks-based software program automatically obtained accurate heat collection rate and heat loss coefficient using simply "portable test instruments" acquired parameters, including tube length, number of tubes, tube center distance, heat water mass in tank, collector area, angle between tubes and ground and final temperature. Our results show that this software (on both personal computer and Android platforms) is efficient and convenient to predict the heat collection rate and heat loss coefficient due to it slow root mean square errors in prediction. The software now can be downloaded from http://t.cn/RLPKF08.

  11. Pulse mitigation and heat transfer enhancement techniques. Volume 3: Liquid sodium heat transfer facility and transient response of sodium heat pipe to pulse forward and reverse heat load

    Science.gov (United States)

    Chow, L. C.; Hahn, O. J.; Nguyen, H. X.

    1992-08-01

    This report presents the description of a liquid sodium heat transfer facility (sodium loop) constructed to support the study of transient response of heat pipes. The facility, consisting of the loop itself, a safety system, and a data acquisition system, can be safely operated over a wide range of temperature and sodium flow rate. The transient response of a heat pipe to pulse heat load at the condenser section was experimentally investigated. A 0.457 m screen wick, sodium heat pipe with an outer diameter of 0.127 m was tested under different heat loading conditions. A major finding was that the heat pipe reversed under a pulse heat load applied at the condenser. The time of reversal was approximately 15 to 25 seconds. The startup of the heat pipe from frozen state was also studied. It was found that during the startup process, at least part of the heat pipe was active. The active region extended gradually down to the end of the condenser until all of the working fluid in the heat pipe was molten.

  12. Modeling Loss-of-Flow Accidents and Their Impact on Radiation Heat Transfer

    Directory of Open Access Journals (Sweden)

    Jivan Khatry

    2017-01-01

    Full Text Available Long-term high payload missions necessitate the need for nuclear space propulsion. The National Aeronautics and Space Administration (NASA investigated several reactor designs from 1959 to 1973 in order to develop the Nuclear Engine for Rocket Vehicle Application (NERVA. Study of planned/unplanned transients on nuclear thermal rockets is important due to the need for long-term missions. In this work, a system model based on RELAP5 is developed to simulate loss-of-flow accidents on the Pewee I test reactor. This paper investigates the radiation heat transfer between the fuel elements and the structures around it. In addition, the impact on the core fuel element temperature and average core pressure was also investigated. The following expected results were achieved: (i greater than normal fuel element temperatures, (ii fuel element temperatures exceeding the uranium carbide melting point, and (iii average core pressure less than normal. Results show that the radiation heat transfer rate between fuel elements and cold surfaces increases with decreasing flow rate through the reactor system. However, radiation heat transfer decreases when there is a complete LOFA. When there is a complete LOFA, the peripheral coolant channels of the fuel elements handle most of the radiation heat transfer. A safety system needs to be designed to counteract the decay heat resulting from a post-LOFA reactor scram.

  13. Optimizing the District Heating Primary Network from the Perspective of Economic-Specific Pressure Loss

    Directory of Open Access Journals (Sweden)

    Haichao Wang

    2017-07-01

    Full Text Available A district heating (DH system is one of the most important components of infrastructures in cold areas. Proper DH network design should balance the initial investment and the heat distribution cost of the DH network. Currently, this design is often based on a recommended value for specific pressure loss (R = ∆P/L in the main lines. This will result in a feasible network design, but probably not be optimal in most cases. The paper develops a novel optimization model to facilitate the design by considering the initial investment in the pipes and the heat distribution costs. The model will generate all possible network scenarios consisting of different series of diameters for each pipe in the flow direction of the network. Then, the annuity on the initial investment, the heat distribution cost, and the total annual cost will be calculated for each network scenario, taking into account the uncertainties of the material prices and the yearly operating time levels. The model is applied to a sample DH network and the results indicate that the model works quite well, clearly identifying the optimal network design and demonstrating that the heat distribution cost is more important than the initial investment in DH network design.

  14. STEAM GENERATOR TUBE INTEGRITY ANALYSIS OF A TOTAL LOSS OF ALL HEAT SINKS ACCIDENT FOR WOLSONG NPP UNIT 1

    Directory of Open Access Journals (Sweden)

    HEOK-SOON LIM

    2014-02-01

    Full Text Available A total loss of all heat sinks is considered a severe accident with a low probability of occurrence. Following a total loss of all heat sinks, the degasser/condenser relief valves (DCRV become the sole means available for the depressurization of the primary heat transport system. If a nuclear power plant has a total loss of heat sinks accident, high-temperature steam and differential pressure between the primary heat transport system (PHTS and the steam generator (SG secondary side can cause a SG tube creep rupture. To protect the PHTS during a total loss of all heat sinks accident, a sufficient depressurization capability of the degasser/condenser relief valve and the SG tube integrity is very important. Therefore, an accurate estimation of the discharge through these valves is necessary to assess the impact of the PHTS overprotection and the SG tube integrity of the primary circuit. This paper describes the analysis of DCRV discharge capacity and the SG tube integrity under a total loss of all heat sink using the CATHENA code. It was found that the DCRV's discharge capacity is enough to protect the overpressure in the PHTS, and the SG tube integrity is maintained in a total loss of all heat accident.

  15. Steam Generator Tube Integrity Analysis of A Total Loss of all Heat Sinks Accident for Wolsong NPP Unit 1

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Heoksoon; Song, Taeyoung; Chi, Moongoo [Korea Htydro and Nuclear Power Co., Ltd., Daejeon (Korea, Republic of); Kim, Seoungrae [Nuclear Engineering Service and Solution, Daejeon (Korea, Republic of)

    2014-02-15

    A total loss of all heat sinks is considered a severe accident with a low probability of occurrence. Following a total loss of all heat sinks, the degasser/condenser relief valves (DCRV) become the sole means available for the depressurization of the primary heat transport system. If a nuclear power plant has a total loss of heat sinks accident, high-temperature steam and differential pressure between the primary heat transport system (PHTS) and the steam generator (SG) secondary side can cause a SG tube creep rupture. To protect the PHTS during a total loss of all heat sinks accident, a sufficient depressurization capability of the degasser/condenser relief valve and the SG tube integrity is very important. Therefore, an accurate estimation of the discharge through these valves is necessary to assess the impact of the PHTS overprotection and the SG tube integrity of the primary circuit. This paper describes the analysis of DCRV discharge capacity and the SG tube integrity under a total loss of all heat sink using the CATHENA code. It was found that the DCRV's discharge capacity is enough to protect the overpressure in the PHTS, and the SG tube integrity is maintained in a total loss of all heat accident.

  16. Steam Generator Tube Integrity Analysis of A Total Loss of all Heat Sinks Accident for Wolsong NPP Unit 1

    International Nuclear Information System (INIS)

    Lim, Heoksoon; Song, Taeyoung; Chi, Moongoo; Kim, Seoungrae

    2014-01-01

    A total loss of all heat sinks is considered a severe accident with a low probability of occurrence. Following a total loss of all heat sinks, the degasser/condenser relief valves (DCRV) become the sole means available for the depressurization of the primary heat transport system. If a nuclear power plant has a total loss of heat sinks accident, high-temperature steam and differential pressure between the primary heat transport system (PHTS) and the steam generator (SG) secondary side can cause a SG tube creep rupture. To protect the PHTS during a total loss of all heat sinks accident, a sufficient depressurization capability of the degasser/condenser relief valve and the SG tube integrity is very important. Therefore, an accurate estimation of the discharge through these valves is necessary to assess the impact of the PHTS overprotection and the SG tube integrity of the primary circuit. This paper describes the analysis of DCRV discharge capacity and the SG tube integrity under a total loss of all heat sink using the CATHENA code. It was found that the DCRV's discharge capacity is enough to protect the overpressure in the PHTS, and the SG tube integrity is maintained in a total loss of all heat accident

  17. NO formation in the burnout region of a partially premixed methane-air flame with upstream heat loss

    Energy Technology Data Exchange (ETDEWEB)

    Mokhov, A.V.; Levinsky, H.B.

    1999-09-01

    Measurements of temperature and NO concentration in laminar, partially premixed methane-air flames stabilized on a ceramic burner in coflow are reported. The NO concentration and temperature were determined by laser-induced fluorescence (LIF) and coherent anti-Stokes Raman scattering (CARS), respectively. Upstream heat loss to the burner was varied by changing the exit velocity of the fuel-air mixture at a constant equivalence ratio of 1,3; this alters the structure of the flame from an axisymmetric Bunsen-type to a strongly stabilized flat flame. To facilitate analysis of the results, a method is derived for separating the effects of dilution from those of chemical reaction based on the relation between the measured temperature and the local mixture fraction, including the effects of upstream heat loss. Using this method, the amount of NO formed during burnout of the hot, fuel-rich combustion products can be ascertained. In the Bunsen-type flame, it is seen that {approximately}40 ppm of NO are produced in this burnout region, at temperatures between {approximately}2,100 K and {approximately}1,900 K, probably via the Zeldovich mechanism. Reducing the exit velocity of 12 cm/s reduces the flame temperature substantially, and effectively eliminates this contribution. At velocities of 12 and 8 cm/s, {approximately}10 ppm of NO are formed in the burnout region, even though the gas temperatures are too low for Zeldovich NO to be significant. Although the mechanism responsible for these observations is as yet unclear, the results are consistent with the idea that the low temperatures in the fuel-rich gases caused by upstream heat loss retard the conversion of HCN (formed via the Fenimore mechanism) to NO, with this residual HCN then being converted to NO during burnout.

  18. Performance evaluation of a biomass boiler on the basis of heat loss method and total heat values of steam

    International Nuclear Information System (INIS)

    Munir, A.; Alvi, J.Z.; Ashfaq, S.; Ghafoor, A.

    2014-01-01

    Pakistan being an agricultural country has large resources of biomass in the form of crop residues like wood, wheat straw, rice husk, cotton sticks and bagasse. Power generation using biomass offers an excellent opportunity to overcome current scenario of energy crises. Of the all biomass resources, bagasse is one of the potential energy sources which can be successfully utilized for power generation. During the last decade, bagasse fired boilers attained major importance due to increasing prices of primary energy (e.g. fossil fuels). Performance of a bagasse fired boiler was evaluated at Shakarganj Sugar Mill, Bhone-Jhang having steam generation capacity of 80 tons h/sup -1/at 25 bar working pressure. The unit was forced circulation and bi-drum type water tube boiler which was equipped with all accessories like air heater, economizer and super-heater. Flue gas analyzer and thermocouples were used to record percent composition and temperature of flue gases respectively. Physical analysis of bagasse showed gross calorific value of bagasse as 2326 kCal kg/sup -1/. Ultimate analysis of bagasse was performed and the actual air supplied to the boiler was calculated to be 4.05 kg per kg of bagasse under the available resources of the plant. Performance evaluation of the boiler was carried out and a complete heat balance sheet was prepared to investigate the different sources of heat losses. The efficiency of the boiler was evaluated on the basis of heat losses through boiler and was found to be 56.08%. It was also determined that 2 kg of steam produced from 1 kg of bagasse under existing condition of the boiler. The performance evaluation of the boiler was also done on the basis of total heat values of steam and found to be 55.98%. The results obtained from both the methods were found almost similar. Effects of excess air, stack and ambient temperature on the efficiency of boiler have also been evaluated and presented in the manuscript. (author)

  19. Influence of the heat losses and accumulated heat upon the evolution of the thermohydraulic processes in the transients as applied to the ISB-WWER integral test facility

    International Nuclear Information System (INIS)

    Gashenko, I.V.; Melikhov, O.I.; Shmal, I.I.; Kouznetsov, V.D.

    2001-01-01

    The results of the calculational study using the RELAP5/MOD3.2 thermalhydraulic code performed on the influence of the heat losses to the ambient and the heat accumulated in the pipelines walls upon the evolution of the thermalhydraulic processes in the primary circuit of the integral test facility ISB-WWER when simulating the transients caused by the loss of the coolant are presented in the paper. (authors)

  20. Impact of thermodynamic properties and heat loss on ignition of transportation fuels in rapid compression machines

    KAUST Repository

    Ahmed, Ahfaz

    2018-01-30

    Rapid compression machines (RCM) are extensively used to study autoignition of a wide variety of fuels at engine relevant conditions. Fuels ranging from pure species to full boiling range gasoline and diesel can be studied in an RCM to develop a better understanding of autoignition kinetics in low to intermediate temperature ranges. In an RCM, autoignition is achieved by compressing a fuel/oxidizer mixture to higher pressure and temperature, thereby initiating chemical reactions promoting ignition. During these experiments, the pressure is continuously monitored and is used to deduce significant events such as the end of compression and the onset of ignition. The pressure profile is also used to assess the temperature evolution of the gas mixture with time using the adiabatic core hypothesis and the heat capacity ratio of the gas mixture. In such RCM studies, real transportation fuels containing many components are often represented by simpler surrogate fuels. While simpler surrogates such as primary reference fuels (PRFs) and ternary primary reference fuel (TPRFs) can match research and motor octane number of transportation fuels, they may not accurately replicate thermodynamic properties (including heat capacity ratio). This non-conformity could exhibit significant discrepancies in the end of compression temperature, thereby affecting ignition delay (τign) measurements. Another aspect of RCMs that can affect τign measurement is post compression heat loss, which depends on various RCM parameters including geometry, extent of insulation, pre-heating temperature etc. To, better understand the effects of these non-chemical kinetic parameters on τign, thermodynamic properties of a number of FACE G gasoline surrogates were calculated and simulated in a multi-zone RCM model. The problem was further investigated using a variance based analysis and individual sensitivities were calculated. This study highlights the effects on τign due to thermodynamic properties of

  1. Impact of thermodynamic properties and heat loss on ignition of transportation fuels in rapid compression machines

    KAUST Repository

    Ahmed, Ahfaz; Hantouche, Mireille; Khurshid, Muneeb; Mohamed, Samah; Nasir, Ehson Fawad; Farooq, Aamir; Roberts, William L.; Knio, Omar; Sarathy, Mani

    2018-01-01

    Rapid compression machines (RCM) are extensively used to study autoignition of a wide variety of fuels at engine relevant conditions. Fuels ranging from pure species to full boiling range gasoline and diesel can be studied in an RCM to develop a better understanding of autoignition kinetics in low to intermediate temperature ranges. In an RCM, autoignition is achieved by compressing a fuel/oxidizer mixture to higher pressure and temperature, thereby initiating chemical reactions promoting ignition. During these experiments, the pressure is continuously monitored and is used to deduce significant events such as the end of compression and the onset of ignition. The pressure profile is also used to assess the temperature evolution of the gas mixture with time using the adiabatic core hypothesis and the heat capacity ratio of the gas mixture. In such RCM studies, real transportation fuels containing many components are often represented by simpler surrogate fuels. While simpler surrogates such as primary reference fuels (PRFs) and ternary primary reference fuel (TPRFs) can match research and motor octane number of transportation fuels, they may not accurately replicate thermodynamic properties (including heat capacity ratio). This non-conformity could exhibit significant discrepancies in the end of compression temperature, thereby affecting ignition delay (τign) measurements. Another aspect of RCMs that can affect τign measurement is post compression heat loss, which depends on various RCM parameters including geometry, extent of insulation, pre-heating temperature etc. To, better understand the effects of these non-chemical kinetic parameters on τign, thermodynamic properties of a number of FACE G gasoline surrogates were calculated and simulated in a multi-zone RCM model. The problem was further investigated using a variance based analysis and individual sensitivities were calculated. This study highlights the effects on τign due to thermodynamic properties of

  2. Heat production, respiratory quotient, and methane loss subsequent to LPS challenge in beef heifers

    Science.gov (United States)

    Respiration calorimetry was used to measure energy utilization during an acute phase response (APR) to lipopolysaccharide (LPS). Eight Angus heifers (208 +/- 29.2 kg) were randomly assigned to one of two calorimeters in four 2-day periods for measurement of heat production (HP), methane (CH4), and r...

  3. Numerical Studies on Natural Convection Heat Losses from Open Cubical Cavities

    Directory of Open Access Journals (Sweden)

    M. Prakash

    2013-01-01

    Full Text Available The natural convection heat losses occurring from cubical open cavities are analysed in this paper. Open cubical cavities of sides 0.1 m, 0.2 m, 0.25 m, 0.5 m, and 1 m with constant temperature back wall boundary conditions and opening ratio of 1 are studied. The Fluent CFD software is used to analyse the three-dimensional (3D cavity models. The studies are carried out for cavities with back wall temperatures between 35°C and 100°C. The effect of cavity inclination on the convective loss is analysed for angles of 0° (cavity facing sideways, 30°, 45°, 60°, and 90° (cavity facing vertically downwards. The Rayleigh numbers involved in this study range between 4.5 × 105 and 1.5 × 109. The natural convection loss is found to increase with an increase in back wall temperature. The natural convection loss is observed to decrease with an increase in cavity inclination; the highest convective loss being at 0° and the lowest at 90° inclination. This is observed for all cavities analysed here. Nusselt number correlations involving the effect of Rayleigh number and the cavity inclination angle have been developed from the current studies. These correlations can be used for engineering applications such as electronic cooling, low- and medium-temperature solar thermal systems, passive architecture, and also refrigeration systems.

  4. Canine tumor and normal tissue response to heat and radiation

    International Nuclear Information System (INIS)

    Gillette, E.L.; McChesney, S.L.

    1985-01-01

    Oral squamous cell carcinomas of dogs were treated with either irradiation alone or combined with hyperthermia. Tumor control was assessed as no evidence of disease one year following treatment. Dogs were randomized to variable radiation doses which were given in ten fractions three times a week for three weeks. Heat was given three hours after the first and third radiation dose each week for seven treatments. The attempt was made to achieve a minimum tumor temperature of 42 0 C for thirty minutes with a maximum normal tissue temperature of 40 0 C. It was usually possible to selectively heat tumors. The TCD 50 for irradiation alone was about 400 rads greater than for heat plus irradiation. The dose response curve for heat plus radiation was much steeper than for radiation alone indicating less heterogeneity of tumor response. That also implies a much greater effectiveness of radiation combined with heat at higher tumor control probabilities. Early necrosis caused by heating healed with conservative management. No increase in late radiation necrosis was observed

  5. Heat loss analysis-based design of a 12 MW wind power generator module having an HTS flux pump exciter

    International Nuclear Information System (INIS)

    Sung, Hae-Jin; Go, Byeong-Soo; Jiang, Zhenan; Park, Minwon; Yu, In-Keun

    2016-01-01

    Highlights: • A large-scale HTS generator module has been suggested to avoid issues such as a huge vacuum vessel and higher reliability. • The challenging heat loss analysis of a large-scale HTS generator has successfully been performed, enabling the design of an optimal support structure having a total heat loss of 43 W/400 kW. • The results prove the potential of a large-scale superconducting wind-power generator to operate efficiently, and support further development of the concept. - Abstract: The development of an effective high-temperature superconducting (HTS) generator is currently a research focus; however, the reduction of heat loss of a large-scale HTS generator is a challenge. This study deals with a heat loss analysis-based design of a 12 MW wind power generator module having an HTS flux pump exciter. The generator module consists of an HTS rotor of the generator and an HTS flux pump exciter. The specifications of the module were described, and the detailed configuration of the module was illustrated. For the heat loss analysis of the module, the excitation loss of the flux pump exciter, eddy current loss of all of the structures in the module, radiation loss, and conduction loss of an HTS coil supporter were assessed using a 3D finite elements method program. In the case of the conduction loss, different types of the supporters were compared to find out the supporter of the lowest conduction loss in the module. The heat loss analysis results of the module were reflected in the design of the generator module and discussed in detail. The results will be applied to the design of large-scale superconducting generators for wind turbines including a cooling system.

  6. Heat loss analysis-based design of a 12 MW wind power generator module having an HTS flux pump exciter

    Energy Technology Data Exchange (ETDEWEB)

    Sung, Hae-Jin, E-mail: haejin0216@gmail.com [Changwon National University, 20 Changwondaehak-ro, Changwon, 641-773 (Korea, Republic of); Go, Byeong-Soo [Changwon National University, 20 Changwondaehak-ro, Changwon, 641-773 (Korea, Republic of); Jiang, Zhenan [Robinson Research Institute, Victoria University of Wellington, PO Box 33436 (New Zealand); Park, Minwon [Changwon National University, 20 Changwondaehak-ro, Changwon, 641-773 (Korea, Republic of); Yu, In-Keun, E-mail: yuik@changwon.ac.kr [Changwon National University, 20 Changwondaehak-ro, Changwon, 641-773 (Korea, Republic of)

    2016-11-15

    Highlights: • A large-scale HTS generator module has been suggested to avoid issues such as a huge vacuum vessel and higher reliability. • The challenging heat loss analysis of a large-scale HTS generator has successfully been performed, enabling the design of an optimal support structure having a total heat loss of 43 W/400 kW. • The results prove the potential of a large-scale superconducting wind-power generator to operate efficiently, and support further development of the concept. - Abstract: The development of an effective high-temperature superconducting (HTS) generator is currently a research focus; however, the reduction of heat loss of a large-scale HTS generator is a challenge. This study deals with a heat loss analysis-based design of a 12 MW wind power generator module having an HTS flux pump exciter. The generator module consists of an HTS rotor of the generator and an HTS flux pump exciter. The specifications of the module were described, and the detailed configuration of the module was illustrated. For the heat loss analysis of the module, the excitation loss of the flux pump exciter, eddy current loss of all of the structures in the module, radiation loss, and conduction loss of an HTS coil supporter were assessed using a 3D finite elements method program. In the case of the conduction loss, different types of the supporters were compared to find out the supporter of the lowest conduction loss in the module. The heat loss analysis results of the module were reflected in the design of the generator module and discussed in detail. The results will be applied to the design of large-scale superconducting generators for wind turbines including a cooling system.

  7. Influence of resonant magnetic perturbations on transient heat load deposition and fast ion losses

    International Nuclear Information System (INIS)

    Rack, Michael Thomas

    2014-01-01

    losses in the presence of resonant magnetic perturbation fields, is presented. It is used to investigate the impact of various types of perturbation field, static and rotating, on the losses. The investigations of the heat load deposition profiles show important features of the resonant magnetic perturbation fields. Firstly, the heat can be favourably redistributed to reduce the local heat fluxes; secondly, a physical process is observed that appears to be linked to the heat redistribution and causes a slow propagation of a heat flux pattern long before the major energy is ejected. This opens a new view on the physics of resonant magnetic perturbation fields as it shows that processes on different time-scales are involved during the control of the plasma edge instabilities. The control of these instabilities can benefit from the new method of applying resonant magnetic perturbation fields using lower hybrid waves. This method provides high flexibility as needed to optimize the heat load redistribution. It is proven to create perturbation fields that are always resonant in the plasma edge region. In addition, it was found that no clear drawbacks appear over a wide range of perturbation fields; moreover, strong indications for an improvement of the fast ion confinement are seen. The overall results provide a positive outlook for the application of resonant magnetic perturbation fields to control edge instabilities: (a) an advantageous redistribution of transient heat loads is achievable, (b) lower hybrid waves can be used for the production of highly flexible resonant magnetic perturbation fields, and (c) resonant magnetic perturbation fields do not necessarily reduce the fast ion confinement. These results show that an optimization of the applied magnetic perturbation fields is able to solve the problem of transient heat loads without any drawbacks for the crucial fast ion confinement.

  8. Influence of resonant magnetic perturbations on transient heat load deposition and fast ion losses

    Energy Technology Data Exchange (ETDEWEB)

    Rack, Michael Thomas

    2014-07-11

    losses in the presence of resonant magnetic perturbation fields, is presented. It is used to investigate the impact of various types of perturbation field, static and rotating, on the losses. The investigations of the heat load deposition profiles show important features of the resonant magnetic perturbation fields. Firstly, the heat can be favourably redistributed to reduce the local heat fluxes; secondly, a physical process is observed that appears to be linked to the heat redistribution and causes a slow propagation of a heat flux pattern long before the major energy is ejected. This opens a new view on the physics of resonant magnetic perturbation fields as it shows that processes on different time-scales are involved during the control of the plasma edge instabilities. The control of these instabilities can benefit from the new method of applying resonant magnetic perturbation fields using lower hybrid waves. This method provides high flexibility as needed to optimize the heat load redistribution. It is proven to create perturbation fields that are always resonant in the plasma edge region. In addition, it was found that no clear drawbacks appear over a wide range of perturbation fields; moreover, strong indications for an improvement of the fast ion confinement are seen. The overall results provide a positive outlook for the application of resonant magnetic perturbation fields to control edge instabilities: (a) an advantageous redistribution of transient heat loads is achievable, (b) lower hybrid waves can be used for the production of highly flexible resonant magnetic perturbation fields, and (c) resonant magnetic perturbation fields do not necessarily reduce the fast ion confinement. These results show that an optimization of the applied magnetic perturbation fields is able to solve the problem of transient heat loads without any drawbacks for the crucial fast ion confinement.

  9. Distance determination of NPP and oil reservoir on enhanced oil recovery based on heat loss and safety in view point

    International Nuclear Information System (INIS)

    Erlan Dewita; Dedy Priambodo; Sudi Ariyanto

    2013-01-01

    EOR is a method used to increasing oil recovery by injecting material or other to the reservoir. There are 3 EOR technique have been used in the world, namely thermal injection, chemical injection dan Miscible. Thermal injection method is the method most widely used in the world, however, one drawback is the loss of heat during steam distribution to the injection wells. In Indonesia, EOR application has been successfully done in the field of Duri, Chevron uses steam injection method, but still use petroleum as a fuel for steam production. In order to save oil reserves, it was done the introduction of co-generation nuclear power plants to supply some of the heat of nuclear power plants for EOR processes. In cogeneration nuclear power plant, the safety aspect is main priority. The purpose of the study was to evaluate the distance NPP with oil wells by considering heat loss and safety aspects. The method of study and calculations done using Tempo Cycle program. The study results showed that in the distance of 400 meter as exclusion zone of PBMR reactor, with pipe insulation thickness 1 in, the amount of heat loss of 277, 883 kw, while in pipe isolation thickness 2 in, amount of heat loss became 162,634 kw and with isolation thickness 3 in, amount of heat loss 120,767 kw., heat loss can be overcome and provide insulation pipes and improve the quality of saturated steam into superheated. (author)

  10. Retinoblastoma loss modulates DNA damage response favoring tumor progression.

    Directory of Open Access Journals (Sweden)

    Marcos Seoane

    Full Text Available Senescence is one of the main barriers against tumor progression. Oncogenic signals in primary cells result in oncogene-induced senescence (OIS, crucial for protection against cancer development. It has been described in premalignant lesions that OIS requires DNA damage response (DDR activation, safeguard of the integrity of the genome. Here we demonstrate how the cellular mechanisms involved in oncogenic transformation in a model of glioma uncouple OIS and DDR. We use this tumor type as a paradigm of oncogenic transformation. In human gliomas most of the genetic alterations that have been previously identified result in abnormal activation of cell growth signaling pathways and deregulation of cell cycle, features recapitulated in our model by oncogenic Ras expression and retinoblastoma (Rb inactivation respectively. In this scenario, the absence of pRb confers a proliferative advantage and activates DDR to a greater extent in a DNA lesion-independent fashion than cells that express only HRas(V12. Moreover, Rb loss inactivates the stress kinase DDR-associated p38MAPK by specific Wip1-dependent dephosphorylation. Thus, Rb loss acts as a switch mediating the transition between premalignant lesions and cancer through DDR modulation. These findings may have important implications for the understanding the biology of gliomas and anticipate a new target, Wip1 phosphatase, for novel therapeutic strategies.

  11. The dry-heat loss effect of melt-spun phase change material fibres.

    Science.gov (United States)

    Tjønnås, Maria Suong; Færevik, Hilde; Sandsund, Mariann; Reinertsen, Randi E

    2015-01-01

    Phase change materials (PCM) have the ability to store latent heat when they change phases, a property that gives clothing that incorporates PCM its cooling effect. This study investigated the effect of dry-heat loss (cooling) of a novel melt-spun PCM fibre on the basis of the area covered, mass, the latent heat of fusion and melting temperature, compared to a known PCM clothing product. PCM fibres with melting temperatures of 28.4 and 32.0°C and PCM packs with melting temperatures of 28.0 and 32.0°C were studied. The results showed that the PCM fibres had a larger initial peak cooling effect than that of the PCM packs. The duration of the cooling effect of PCM fibres was primarily dependent on the PCM mass and the latent heat of fusion capacity, and secondly on the covered area and melting temperature of the PCM. This study investigates the cooling effect of PCM fibres on a thermal manikin. The PCM fibres had a high but short-lasting cooling effect. This study contributes to the knowledge of how the body's temperature regulation may be affected by the cooling properties of clothing that incorporates PCM.

  12. Unmanned Aerial Vehicles for Environmental Monitoring with Special Reference to Heat Loss

    Science.gov (United States)

    Anweiler, Stanisław; Piwowarski, Dawid; Ulbrich, Roman

    2017-10-01

    This paper presents the design and implementation of device for remote and automatic monitoring of temperature field of large objects. The project aimed to create a quadcopter flying platform equipped with a thermal imaging camera. The object of the research was district heating installations above ground and underground. The results of the work on the implementation of low-cost (below 750 EUR) and efficient heat loss monitoring system. The system consists of a small (<2kg) multirotor platform. To perform thermal images micro camera FlirOne with microcomputer Raspberry Pi3 was used. Exploitation of UAVs in temperature field monitoring reveals only a fraction of their capabilities. The fast-growing multirotor platform market continues to deliver new solutions and improvements. Their use in monitoring the environment is limited only by the imagination of the user.

  13. Unmanned Aerial Vehicles for Environmental Monitoring with Special Reference to Heat Loss

    Directory of Open Access Journals (Sweden)

    Anweiler Stanisław

    2017-01-01

    Full Text Available This paper presents the design and implementation of device for remote and automatic monitoring of temperature field of large objects. The project aimed to create a quadcopter flying platform equipped with a thermal imaging camera. The object of the research was district heating installations above ground and underground. The results of the work on the implementation of low-cost (below 750 EUR and efficient heat loss monitoring system. The system consists of a small (<2kg multirotor platform. To perform thermal images micro camera FlirOne with microcomputer Raspberry Pi3 was used. Exploitation of UAVs in temperature field monitoring reveals only a fraction of their capabilities. The fast-growing multirotor platform market continues to deliver new solutions and improvements. Their use in monitoring the environment is limited only by the imagination of the user.

  14. ATHENA simulations of divertor pump trip and loss of heat sink transients for the GSSR

    Energy Technology Data Exchange (ETDEWEB)

    Sjoeberg, A

    2001-04-01

    The ITER-FEAT Generic Site Safety Report includes evaluations of the consequences of various types of conceivable transients that may occur during operation. The transients that have to be considered in this respect are specified in the Accident Analysis Specifications document of the safety report. For the divertor primary heat transport system the ranges of transients include amongst others a trip of the main circulation pump in the divertor cooling loop as well as a loss of heat sink, both initiated at full fusion power operation. The thermal-hydraulic consequences related to the coolability of the divertor primary heat transport system components for these two transients have been evaluated and summarized in the safety report and in the current report an overview of those efforts and associated outcome is provided. The analyses have been made with the ATHENA thermal-hydraulic code using a separately developed ATHENA model of the ITER-FEAT divertor cooling system. The results from the analyses indicate that for the pump trip transient the margin against overheating of critical highly loaded parts of the divertor cassette is small but seems sufficient. In case of the loss of heat sink transient the conservative analysis reveals that the pressurizer safety valve will be opened for an extended period of time and the long term transient development indicates a risk of completely filling up the pressurizer vessel. Thus the margins against jeopardizing the integrity of the divertor cooling system with the current design are for this case small but can for a long term operation at associate conditions pose a problem.

  15. Global transcriptome analysis of the heat shock response ofshewanella oneidensis

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Haichun; Wang, Sarah; Liu, Xueduan; Yan, Tinfeng; Wu, Liyou; Alm, Eric; Arkin, Adam P.; Thompson, Dorothea K.; Zhou, Jizhong

    2004-04-30

    Shewanella oneidensis is an important model organism for bioremediation studies because of its diverse respiratory capabilities. However, the genetic basis and regulatory mechanisms underlying the ability of S. oneidensis to survive and adapt to various environmentally relevant stresses is poorly understood. To define this organism's molecular response to elevated growth temperatures, temporal gene expression profiles were examined in cells subjected to heat stress using whole-genome DNA microarrays for S. oneidensis MR-1. Approximately 15 percent (711) of the predicted S. oneidensis genes represented on the microarray were significantly up- or down-regulated (P < 0.05) over a 25-min period following shift to the heat shock temperature (42 C). As expected, the majority of S. oneidensis genes exhibiting homology to known chaperones and heat shock proteins (Hsps) were highly and transiently induced. In addition, a number of predicted genes encoding enzymes in glycolys is and the pentose cycle, [NiFe] dehydrogenase, serine proteases, transcriptional regulators (MerR, LysR, and TetR families), histidine kinases, and hypothetical proteins were induced in response to heat stress. Genes encoding membrane proteins were differentially expressed, suggesting that cells possibly alter their membrane composition or structure in response to variations in growth temperature. A substantial number of the genes encoding ribosomal proteins displayed down-regulated co-expression patterns in response to heat stress, as did genes encoding prophage and flagellar proteins. Finally, based on computational comparative analysis of the upstream promoter regions of S.oneidensis heat-inducible genes, a putative regulatory motif, showing high conservation to the Escherichia coli sigma 32-binding consensus sequence, was identified.

  16. A method to determine stratification efficiency of thermal energy storage processes independently from storage heat losses

    DEFF Research Database (Denmark)

    Haller, M.Y.; Yazdanshenas, Eshagh; Andersen, Elsa

    2010-01-01

    process is in agreement with the first law of thermodynamics. A comparison of the stratification efficiencies obtained from experimental results of charging, standby, and discharging processes gives meaningful insights into the different mixing behaviors of a storage tank that is charged and discharged......A new method for the calculation of a stratification efficiency of thermal energy storages based on the second law of thermodynamics is presented. The biasing influence of heat losses is studied theoretically and experimentally. Theoretically, it does not make a difference if the stratification...

  17. Physiological response of heat stressed broiler chickens to ...

    African Journals Online (AJOL)

    Effect of supplementing the drinking water of broilers reared under natural heat stress with ammonium chloride (NH4Cl), sodium bicarbonate (NaHCO3), calcium chloride (CaCl2) and ascorbic acid (AA) on physiological response was investigated. A 200, one-day Arbor acre chicks were randomly allotted to five treatments in ...

  18. A Numerical Study on Effect of Gas-Phase Radiative Heat Loss on Extinction of Hydrogen Diffusion Flames

    International Nuclear Information System (INIS)

    Sohn, Chae Hoon

    2007-01-01

    Extinction characteristics of hydrogen-air diffusion flames are investigated numerically by adopting counterflow flame configuration. At various pressures, effect of radiative heat loss on flame extinction is examined. Only gas-phase radiation is considered here. Radiative heat loss depends on flame thickness, temperature, H 2 O concentration, and pressure. From flame structures at various pressures, flame thickness decreases with pressure, but its gradient decreases at high pressure. Flame temperature and mole fraction of H 2 O increase slightly with pressure. Accordingly, as pressure increases, radiative heat loss becomes dominant. When radiative heat loss is considered, radiation-induced extinction is observed at low strain rate in addition to transport-induced extinction. As pressure increases, flammable region shifts to the high-temperature region and then, shrunk to the point on the coordinate plane of flame temperature and strain rate

  19. Fitness-related differences in the rate of whole-body evaporative heat loss in exercising men are heat-load dependent.

    Science.gov (United States)

    Lamarche, Dallon T; Notley, Sean R; Louie, Jeffrey C; Poirier, Martin P; Kenny, Glen P

    2018-01-01

    What is the central question of this study? Aerobic fitness modulates heat loss, but the heat-load threshold at which fitness-related differences in heat loss occur in young healthy men remains unclear. What is the main finding and its importance? We demonstrate using direct calorimetry that aerobic fitness modulates heat loss in a heat-load-dependent manner, with fitness-related differences occurring between young men who have low and high fitness when the heat load is ∼≥500 W. Although aerobic fitness has been known for some time to modulate heat loss, our findings define the precise heat-load threshold at which fitness-related differences occur. The effect of aerobic fitness (defined as rate of peak oxygen consumption) on heat loss during exercise is thought to be related to the level of heat stress. However, it remains unclear at what combined exercise and environmental (net) heat-load threshold these fitness-related differences occur. To identify this, we assessed whole-body heat exchange (dry and evaporative) by direct calorimetry in young (22 ± 3 years) men matched for physical characteristics with low (Low-fit; 39.8 ± 2.5 ml O 2  kg -1  min -1 ), moderate (Mod-fit; 50.9 ± 1.2 ml O 2  kg -1  min -1 ) and high aerobic fitness (High-fit; 62.0 ± 4.4 ml O 2  kg -1  min -1 ; each n = 8), during three 30 min bouts of cycling in dry heat (40°C, 12% relative humidity) at increasing rates of metabolic heat production of 300 (Ex1), 400 (Ex2) and 500 W (Ex3), each followed by a 15 min recovery period. Each group was exposed to a similar net heat load (metabolic plus ∼100 W dry heat gain; P = 0.83) during each exercise bout [∼400 (Ex1), ∼500 (Ex2) and ∼600 W (Ex3); P fit (Ex2, 466 ± 21 W; Ex3, 557 ± 26 W) compared with the Low-fit group (Ex2, 439 ± 22 W; Ex3, 511 ± 20 W) during Ex2 and Ex3 (P ≤ 0.03). Conversely, evaporative heat loss for the Mod-fit group did not differ from either the High-fit or Low

  20. Extreme learning machine: a new alternative for measuring heat collection rate and heat loss coefficient of water-in-glass evacuated tube solar water heaters.

    Science.gov (United States)

    Liu, Zhijian; Li, Hao; Tang, Xindong; Zhang, Xinyu; Lin, Fan; Cheng, Kewei

    2016-01-01

    Heat collection rate and heat loss coefficient are crucial indicators for the evaluation of in service water-in-glass evacuated tube solar water heaters. However, the direct determination requires complex detection devices and a series of standard experiments, wasting too much time and manpower. To address this problem, we previously used artificial neural networks and support vector machine to develop precise knowledge-based models for predicting the heat collection rates and heat loss coefficients of water-in-glass evacuated tube solar water heaters, setting the properties measured by "portable test instruments" as the independent variables. A robust software for determination was also developed. However, in previous results, the prediction accuracy of heat loss coefficients can still be improved compared to those of heat collection rates. Also, in practical applications, even a small reduction in root mean square errors (RMSEs) can sometimes significantly improve the evaluation and business processes. As a further study, in this short report, we show that using a novel and fast machine learning algorithm-extreme learning machine can generate better predicted results for heat loss coefficient, which reduces the average RMSEs to 0.67 in testing.

  1. LOFT/LP-FW-1, Loss of Fluid Test, PWR Response to Loss-of-Feedwater Transient

    International Nuclear Information System (INIS)

    1989-01-01

    1 - Description of test facility: The LOFT Integral Test Facility is a scale model of a LPWR. The intent of the facility is to model the nuclear, thermal-hydraulic phenomena which would take place in a LPWR during a LOCA. The general philosophy in scaling coolant volumes and flow areas in LOFT was to use the ratio of the LOFT core [50 MW(t)] to a typical LPWR core [3000 MW(t)]. For some components, this factor is not applied; however, it is used as extensively as practical. In general, components used in LOFT are similar in design to those of a LPWR. Because of scaling and component design, the LOFT LOCA is expected to closely model a LPWR LOCA. 2 - Description of test: The first OECD LOFT experiment was conducted on February 20, 1983. It was designed to evaluate the generic PWR system response during a complete loss-of-feedwater transient. The objective of the experiment was to investigate the performance of primary 'feed and bleed' using a 'bleed' from the PORV and 'feed' from the HPIS to provide decay heat removal and system pressure reduction while maintaining the primary coolant inventory. 3 - Experimental limitations or shortcomings: Short core and steam generator, excessive core bypass, other scaling compromises, and lack of adequate measurements in certain areas

  2. Barcoding heat shock proteins to human diseases : looking beyond the heat shock response

    NARCIS (Netherlands)

    Kakkar, Vaishali; Meister-Broekema, Melanie; Minoia, Melania; Carra, Serena; Kampinga, Harm H.

    There are numerous human diseases that are associated with protein misfolding and the formation of toxic protein aggregates. Activating the heat shock response (HSR) - and thus generally restoring the disturbed protein homeostasis associated with such diseases - has often been suggested as a

  3. Responses to hyperthermia. Optimizing heat dissipation by convection and evaporation: Neural control of skin blood flow and sweating in humans.

    Science.gov (United States)

    Smith, Caroline J; Johnson, John M

    2016-04-01

    Under normothermic, resting conditions, humans dissipate heat from the body at a rate approximately equal to heat production. Small discrepancies between heat production and heat elimination would, over time, lead to significant changes in heat storage and body temperature. When heat production or environmental temperature is high the challenge of maintaining heat balance is much greater. This matching of heat elimination with heat production is a function of the skin circulation facilitating heat transport to the body surface and sweating, enabling evaporative heat loss. These processes are manifestations of the autonomic control of cutaneous vasomotor and sudomotor functions and form the basis of this review. We focus on these systems in the responses to hyperthermia. In particular, the cutaneous vascular responses to heat stress and the current understanding of the neurovascular mechanisms involved. The available research regarding cutaneous active vasodilation and vasoconstriction is highlighted, with emphasis on active vasodilation as a major responder to heat stress. Involvement of the vasoconstrictor and active vasodilator controls of the skin circulation in the context of heat stress and nonthermoregulatory reflexes (blood pressure, exercise) are also considered. Autonomic involvement in the cutaneous vascular responses to direct heating and cooling of the skin are also discussed. We examine the autonomic control of sweating, including cholinergic and noncholinergic mechanisms, the local control of sweating, thermoregulatory and nonthermoregulatory reflex control and the possible relationship between sudomotor and cutaneous vasodilator function. Finally, we comment on the clinical relevance of these control schemes in conditions of autonomic dysfunction. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Regulatory analysis for the resolution of Generic Issue 99: Loss of RHR [residual heat removal] capability in PWRs

    International Nuclear Information System (INIS)

    Spano, A.H.

    1989-02-01

    Generic Issue 99 is concerned with the loss of residual heat removal (RHR) capability in pressurized water reactors during cold-plant outage operations. The issue focuses on two risk-significant common-cause failure modes of the RHR system: (1) air binding of the RHR pumps during reduced-inventory operations and (2) spurious closure of the RHR suction valves due to misapplication of the autoclosure interlocks. Resolution of this issue involves consideration of the adequacy of plant capabilities for (1) preventing losses of RHR, (2) responding promptly and effectively to such challenges in order to prevent core damage, and (3) ensuring timely containment protection against the release of radioactivity to the environment in the unlikely event of core damage due to loss of shutdown cooling. This entails examination of (1) relevant operational and accident response procedures, (2) the instrumentation available to the operator for accident diagnosis and mitigation, and (3) the administrative controls available for ensuring control room cognizance of ongoing maintenance activities that could potentially affect the stability of the reactor coolant system. This regulatory analysis provides quantitative assessments of the costs and benefits associated with several alternatives considered for the resolution of Generic Issue 99. 24 refs

  5. Minimizing scatter-losses during pre-heat for magneto-inertial fusion targets

    Science.gov (United States)

    Geissel, Matthias; Harvey-Thompson, Adam J.; Awe, Thomas J.; Bliss, David E.; Glinsky, Michael E.; Gomez, Matthew R.; Harding, Eric; Hansen, Stephanie B.; Jennings, Christopher; Kimmel, Mark W.; Knapp, Patrick; Lewis, Sean M.; Peterson, Kyle; Schollmeier, Marius; Schwarz, Jens; Shores, Jonathon E.; Slutz, Stephen A.; Sinars, Daniel B.; Smith, Ian C.; Speas, C. Shane; Vesey, Roger A.; Weis, Matthew R.; Porter, John L.

    2018-02-01

    The size, temporal and spatial shape, and energy content of a laser pulse for the pre-heat phase of magneto-inertial fusion affect the ability to penetrate the window of the laser-entrance-hole and to heat the fuel behind it. High laser intensities and dense targets are subject to laser-plasma-instabilities (LPI), which can lead to an effective loss of pre-heat energy or to pronounced heating of areas that should stay unexposed. While this problem has been the subject of many studies over the last decades, the investigated parameters were typically geared towards traditional laser driven Inertial Confinement Fusion (ICF) with densities either at 10% and above or at 1% and below the laser's critical density, electron temperatures of 3-5 keV, and laser powers near (or in excess of) 1 × 1015 W/cm2. In contrast, Magnetized Liner Inertial Fusion (MagLIF) [Slutz et al., Phys. Plasmas 17, 056303 (2010) and Slutz and Vesey, Phys. Rev. Lett. 108, 025003 (2012)] currently operates at 5% of the laser's critical density using much thicker windows (1.5-3.5 μm) than the sub-micron thick windows of traditional ICF hohlraum targets. This article describes the Pecos target area at Sandia National Laboratories using the Z-Beamlet Laser Facility [Rambo et al., Appl. Opt. 44(12), 2421 (2005)] as a platform to study laser induced pre-heat for magneto-inertial fusion targets, and the related progress for Sandia's MagLIF program. Forward and backward scattered light were measured and minimized at larger spatial scales with lower densities, temperatures, and powers compared to LPI studies available in literature.

  6. A minimization procedure for estimating the power deposition and heat transport from the temperature response to auxiliary power modulation

    International Nuclear Information System (INIS)

    Eester, Dirk van

    2004-01-01

    A method commonly used for determining where externally launched power is absorbed inside a tokamak plasma is to examine the temperature response to modulation of the launched power. Strictly speaking, this response merely provides a first good guess of the actual power deposition rather than the deposition profile itself: not only local heat sources but also heat losses and heat wave propagation affect the temperature response at a given position. Making use of this, at first sight non-desirable, effect modulation becomes a useful tool for conducting transport studies. In this paper a minimization method based on a simple conduction-convection model is proposed for deducing the power deposition and transport characteristics from the experimentally measured (electron) energy density response to a modulation of the auxiliary heating power. An L-mode JET example illustrates the potential of the technique

  7. Tomato yellow leaf curl virus infection mitigates the heat stress response of plants grown at high temperatures

    Science.gov (United States)

    Ghandi, Anfoka; Adi, Moshe; Lilia, Fridman; Linoy, Amrani; Or, Rotem; Mikhail, Kolot; Mouhammad, Zeidan; Henryk, Czosnek; Rena, Gorovits

    2016-01-01

    Cultured tomatoes are often exposed to a combination of extreme heat and infection with Tomato yellow leaf curl virus (TYLCV). This stress combination leads to intense disease symptoms and yield losses. The response of TYLCV-susceptible and resistant tomatoes to heat stress together with viral infection was compared. The plant heat-stress response was undermined in TYLCV infected plants. The decline correlated with the down-regulation of heat shock transcription factors (HSFs) HSFA2 and HSFB1, and consequently, of HSF-regulated genes Hsp17, Apx1, Apx2 and Hsp90. We proposed that the weakened heat stress response was due to the decreased capacity of HSFA2 to translocate into the nuclei of infected cells. All the six TYLCV proteins were able to interact with tomato HSFA2 in vitro, moreover, coat protein developed complexes with HSFA2 in nuclei. Capturing of HSFA2 by viral proteins could suppress the transcriptional activation of heat stress response genes. Application of both heat and TYLCV stresses was accompanied by the development of intracellular large protein aggregates containing TYLCV proteins and DNA. The maintenance of cellular chaperones in the aggregated state, even after recovery from heat stress, prevents the circulation of free soluble chaperones, causing an additional decrease in stress response efficiency. PMID:26792235

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

    Science.gov (United States)

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

    2015-01-01

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

  9. ATHENA simulations of divertor loss of heat sink transient for the GSSR - Final report with updates

    Energy Technology Data Exchange (ETDEWEB)

    Sponton, L.L

    2001-05-01

    The ITER-FEAT Generic Site Safety Report includes evaluations of the consequences of various types of conceivable transients that can occur during operation. The transients that have to be considered in this respect are specified in the Accident Analysis Specifications document of the safety report. For the divertor primary heat transport system the ranges of transients include amongst others a loss of heat sink at full fusion power operation. The thermal-hydraulic consequences related to the coolability of the divertor primary heat transport system components for this transient have been evaluated and summarised in the safety report and in the current report an overview of those efforts and associated outcome is provided. The analyses have been made with the ATHENA thermal-hydraulic code using a separately developed ATHENA model of the ITER-FEAT divertor cooling system. In the current report results from calculations with an updated pressurizer model and pressurizer control system are outlined. The results show that the pressurizer safety valve does not open, that the pressurizer level increase is moderate and that no temperature increases jeopardize the structure integrity.

  10. ATHENA simulations of divertor loss of heat sink transient for the GSSR - Final report with updates

    International Nuclear Information System (INIS)

    Sponton, L.L.

    2001-05-01

    The ITER-FEAT Generic Site Safety Report includes evaluations of the consequences of various types of conceivable transients that can occur during operation. The transients that have to be considered in this respect are specified in the Accident Analysis Specifications document of the safety report. For the divertor primary heat transport system the ranges of transients include amongst others a loss of heat sink at full fusion power operation. The thermal-hydraulic consequences related to the coolability of the divertor primary heat transport system components for this transient have been evaluated and summarised in the safety report and in the current report an overview of those efforts and associated outcome is provided. The analyses have been made with the ATHENA thermal-hydraulic code using a separately developed ATHENA model of the ITER-FEAT divertor cooling system. In the current report results from calculations with an updated pressurizer model and pressurizer control system are outlined. The results show that the pressurizer safety valve does not open, that the pressurizer level increase is moderate and that no temperature increases jeopardize the structure integrity

  11. Core thermal response during Semiscale Mod-1 blowdown heat transfer tests

    International Nuclear Information System (INIS)

    Larson, T.K.

    1976-06-01

    Selected experimental data and results calculated from experimental data obtained from the Semiscale Mod-1 PWR blowdown heat transfer test series are analyzed. These tests were designed primarily to provide information on the core thermal response to a loss-of-coolant accident. The data are analyzed to determine the effect of core flow on the heater rod thermal response. The data are also analyzed to determine the effects of initial operating conditions on the rod cladding temperature behavior during the transient. The departure from nucleate boiling and rewetting characteristics of the rod surfaces are examined for radial and axial patterns in the response. Repeatability of core thermal response data is also investigated. The test data and the core thermal response calculated with the RELAP4 code are compared

  12. Human thermal physiological and psychological responses under different heating environments.

    Science.gov (United States)

    Wang, Zhaojun; Ning, Haoran; Ji, Yuchen; Hou, Juan; He, Yanan

    2015-08-01

    Anecdotal evidence suggests that many residents of severely cold areas of China who use floor heating (FH) systems feel warmer but drier compared to those using radiant heating (RH) systems. However, this phenomenon has not been verified experimentally. In order to validate the empirical hypothesis, and research the differences of human physiological and psychological responses in these two asymmetrical heating environments, an experiment was designed to mimic FH and RH systems. The subjects participating in the experiment were volunteer college-students. During the experiment, the indoor air temperature, air speed, relative humidity, globe temperature, and inner surface temperatures were measured, and subjects' heart rate, blood pressure and skin temperatures were recorded. The subjects were required to fill in questionnaires about their thermal responses during testing. The results showed that the subjects' skin temperatures, heart rate and blood pressure were significantly affected by the type of heating environment. Ankle temperature had greatest impact on overall thermal comfort relative to other body parts, and a slightly cool FH condition was the most pleasurable environment for sedentary subjects. The overall thermal sensation, comfort and acceptability of FH were higher than that of RH. However, the subjects of FH felt drier than that of RH, although the relative humidity in FH environments was higher than that of the RH environment. In future environmental design, the thermal comfort of the ankles should be scrutinized, and a FH cool condition is recommended as the most comfortable thermal environment for office workers. Consequently, large amounts of heating energy could be saved in this area in the winter. The results of this study may lead to more efficient energy use for office or home heating systems. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Study of Power Loss Reduction in SEPR Converters for Induction Heating through Implementation of SiC Based Semiconductor Switches

    Directory of Open Access Journals (Sweden)

    Angel Marinov

    2014-08-01

    Full Text Available This paper presents a power loss analysis for a Single Ended Parallel Resonance (SEPR Converter used for induction heating. The analysis includes a comparison of the losses in the electronic switch when the circuit is realized using a conventional Silicon (Si based IGBT or when using Silicon Carbide (SiC based MOSFET. The analysis includes modelling and simulation as well as experimental verification through power loss and heat dissipation measurement. The presented results can be used as a base of comparison between the switches and can be a starting point for efficiency based design of those types of converters.

  14. Osmotic heat engine using thermally responsive ionic liquids

    KAUST Repository

    Zhong, Yujiang

    2017-07-11

    The osmotic heat engine (OHE) is a promising technology for converting low grade heat to electricity. Most of the existing studies have focused on thermolytic salt systems. Herein, for the first time, we proposed to use thermally responsive ionic liquids (TRIL) that have either an upper critical solution temperature (UCST) or lower critical solution temperature (LCST) type of phase behavior as novel thermolytic osmotic agents. Closed-loop TRIL-OHEs were designed based on these unique phase behaviors to convert low grade heat to work or electricity. Experimental studies using two UCST-type TRILs, protonated betaine bis(trifluoromethyl sulfonyl)imide ([Hbet][Tf2N]) and choline bis(trifluoromethylsulfonyl)imide ([Choline][Tf2N]) showed that (1) the specific energy of the TRIL-OHE system could reach as high as 4.0 times that of the seawater and river water system, (2) the power density measured from a commercial FO membrane reached up to 2.3 W/m2, and (3) the overall energy efficiency reached up to 2.6% or 18% of the Carnot efficiency at no heat recovery and up to 10.5% or 71% of the Carnet efficiency at 70% heat recovery. All of these results clearly demonstrated the great potential of using TRILs as novel osmotic agents to design high efficient OHEs for recovery of low grade thermal energy to work or electricity.

  15. Effect of prolonged heat treatments at low temperature on shear force and cooking loss in cows and young bulls

    DEFF Research Database (Denmark)

    Christensen, L.; Andersen, L.; Løje, Hanne

    2011-01-01

    and cooking loss in semitendinosus from cows (4-6 years) and young bulls (12-14 months), representing 2 categories of beef with varying thermal strength of connective tissue. Vacuum packed muscle samples were heat treated at 53°C, 55°C, 58°C and 63°C in water baths for 2½, 7½ and 19½ h. Cooking loss...... 53°C to 55°C, or when increasing heating time from 2½ to 7½ h at 53°C. In semitendinosus from cows shear force decreased significantly with increasing temperature, and with increasing heating time from 2½ to 19½ h at 55°C and 63°C. Cooking loss increased with increasing heating temperature in both...

  16. Microstructural response to heat affected zone cracking of prewelding heat-treated Inconel 939 superalloy

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, M.A., E-mail: mgonzalez@comimsa.com.mx [Facultad de Ingenieria Mecanica y Electrica (FIME-UANL), Av. Universidad s/n. Ciudad Universitaria, C.P.66451 San Nicolas de los Garza, N.L. (Mexico); Martinez, D.I., E-mail: dorairma@yahoo.com [Facultad de Ingenieria Mecanica y Electrica (FIME-UANL), Av. Universidad s/n. Ciudad Universitaria, C.P.66451 San Nicolas de los Garza, N.L. (Mexico); Perez, A., E-mail: betinperez@hotmail.com [Facultad de Ingenieria Mecanica y Electrica (FIME-UANL), Av. Universidad s/n. Ciudad Universitaria, C.P.66451 San Nicolas de los Garza, N.L. (Mexico); Guajardo, H., E-mail: hguajardo@frisa.com [FRISA Aerospace, S.A. de C.V., Valentin G. Rivero No. 200, Col. Los Trevino, C.P. 66150, Santa Caterina N.L. (Mexico); Garza, A., E-mail: agarza@comimsa.com [Corporacion Mexicana de Investigacion en Materiales S.A. de C.V. (COMIMSA), Ciencia y Tecnologia No.790, Saltillo 400, C.P. 25295 Saltillo Coah. (Mexico)

    2011-12-15

    The microstructural response to cracking in the heat-affected zone (HAZ) of a nickel-based IN 939 superalloy after prewelding heat treatments (PWHT) was investigated. The PWHT specimens showed two different microstructures: 1) spherical ordered {gamma} Prime precipitates (357-442 nm), with blocky MC and discreet M{sub 23}C{sub 6} carbides dispersed within the coarse dendrites and in the interdendritic regions; and 2) ordered {gamma} Prime precipitates in 'ogdoadically' diced cube shapes and coarse MC carbides within the dendrites and in the interdendritic regions. After being tungsten inert gas welded (TIG) applying low heat input, welding speed and using a more ductile filler alloy, specimens with microstructures consisting of spherical {gamma} Prime precipitate particles and dispersed discreet MC carbides along the grain boundaries, displayed a considerably improved weldability due to a strong reduction of the intergranular HAZ cracking associated with the liquation microfissuring phenomena. - Highlights: Black-Right-Pointing-Pointer Homogeneous microstructures of {gamma} Prime spheroids and discreet MC carbides of Ni base superalloys through preweld heat treatments. Black-Right-Pointing-Pointer {gamma} Prime spheroids and discreet MC carbides reduce the intergranular HAZ liquation and microfissuring of Nickel base superalloys. Black-Right-Pointing-Pointer Microstructure {gamma} Prime spheroids and discreet blocky type MC carbides, capable to relax the stress generated during weld cooling. Black-Right-Pointing-Pointer Low welding heat input welding speeds and ductile filler alloys reduce the HAZ cracking susceptibility.

  17. SCDAP/RELAP5 modeling of heat transfer and flow losses in lower head porous debris. Rev. 1

    International Nuclear Information System (INIS)

    Siefken, L.J.; Coryell, E.W.; Paik, S.; Kuo, H.

    1999-01-01

    Designs are described for implementing models for calculating the heat transfer and flow losses in porous debris in the lower head of a reactor vessel. The COUPLE model in SCDAP/RELAP5 represents both the porous and nonporous debris that results from core material slumping into the lower head. Currently, the COUPLE model has the capability to model convective and radiative heat transfer from the surfaces of nonporous debris in a detailed manner and to model only in a simplistic manner the heat transfer from porous debris. In order to advance beyond the simplistic modeling for porous debris, designs are developed for detailed calculations of heat transfer and flow losses in porous debris. Correlations are identified for convective heat transfer in porous debris for the following modes of heat transfer; (1) forced convection to liquid, (2) forced convection to gas, (3) nucleate boiling, (4) transition boiling, and (5) film boiling. Interphase heat transfer is modeled in an approximate ma nner. Designs are described for models to calculate the flow losses and interphase drag of fluid flowing through the interstices of the porous debris, and to apply these variables in the momentum equations in the RELAP5 part of the code. Since the models for heat transfer and flow losses in porous debris in the lower head are designed for general application, a design is also described for implementation of these models to the analysis of porous debris in the core region. A test matrix is proposed for assessing the capability of the implemented models to calculate the heat transfer and flow losses in porous debris. The implementation of the models described in this report is expected to improve the COUPLE code calculation of the temperature distribution in porous debris and in the lower head that supports the debris. The implementation of these models is also expected to improve the calculation of the temperature and flow distribution in porous debris in the core region

  18. Life cycle biological efficiency of mice divergently selected for heat loss.

    Science.gov (United States)

    Bhatnagar, A S; Nielsen, M K

    2014-08-01

    Divergent selection in mice for heat loss was conducted in 3 independent replicates creating a high maintenance, high heat loss (MH) and low maintenance, low heat loss (ML) line and unselected control (MC). Improvement in feed efficiency was observed in ML mice due to a reduced maintenance energy requirement but there was also a slight decline in reproductive performance, survivability, and lean content, particularly when compared to MC animals. The objective of this study was to model a life cycle scenario similar to a livestock production system and calculate total inputs and outputs to estimate overall biological efficiency of these lines and determine if reduced feed intake resulted in improved life cycle efficiency. Feed intake, reproductive performance, growth, and body composition were recorded on 21 mating pairs from each line × replicate combination, cohabitated at 7 wk of age and maintained for up to 1 yr unless culled. Proportion of animals at each parity was calculated from survival rates estimated from previous research when enforcing a maximum of 4, 8, or 12 allowed parities. This parity distribution was then combined with values from previous studies to calculate inputs and outputs of mating pairs and offspring produced in a single cycle at equilibrium. Offspring output was defined as kilograms of lean output of offspring at 49 d. Offspring input was defined as megacalories of energy intake for growing offspring from 21 to 49 d. Parent output was defined as kilograms of lean output of culled parents. Parent input was defined as megacalories of energy intake for mating pairs from weaning of one parity to weaning of the next. Offspring output was greatest in MC mice due to superior BW and numbers weaned, while output was lowest in ML mice due to smaller litter sizes and lean content. Parent output did not differ substantially between lines but was greatest in MH mice due to poorer survival rates resulting in more culled animals. Input was greatest in

  19. Analysis of thermal-dose response to heat

    International Nuclear Information System (INIS)

    Storm, F.; Roe, D.; Drury, B.

    1987-01-01

    The authors reasoned that if hyperthermia alone has a clinical anti-tumor effect, response should have a thermal dose relationship. The authors analyzed 100 patients with advanced cancer treated with magnetic-induction. Three methods of determining thermal dose were used: (A) t1x10, the lowest temperature sustained throughout the tumor for 30-60min during the first of ten daily treatments, which represents one usual course of ten hourly sessions; (B) t43 (equivalent minutes at 43C) which accounts for non-linear tumor heating by combining serially measured temperatures during the first treatment with a mathematical description of the time-temperature relationship for thermal inactivation or damage; (C) Ct43 (cumulative t43), which represents the t43 value multiplied by the actual number of subsequent daily treatments received. Response was defined as CR+PR+MR. The results show a statistically significant effect of heat alone for t1x10, t43, and Ct43. These analyses demonstrate a thermal-dose relationship between hyperthermia therapy and tumor response as a sole independent variable, which indicates that heat therapy has clinical anti-cancer activity

  20. Effects of heat loss as percentage of fuel's energy, friction and variable specific heats of working fluid on performance of air standard Otto cycle

    International Nuclear Information System (INIS)

    Lin, J.-C.; Hou, S.-S.

    2008-01-01

    The objective of this study is to analyze the effects of heat loss characterized by a percentage of the fuel's energy, friction and variable specific heats of working fluid on the performance of an air standard Otto cycle with a restriction of maximum cycle temperature. A more realistic and precise relationship between the fuel's chemical energy and the heat leakage that is based on a pair of inequalities is derived through the resulting temperature. The variations in power output and thermal efficiency with compression ratio, and the relations between the power output and the thermal efficiency of the cycle are presented. The results show that the power output as well as the efficiency where maximum power output occurs will increase with increase of the maximum cycle temperature. The temperature dependent specific heats of the working fluid have a significant influence on the performance. The power output and the working range of the cycle increase with the increase of specific heats of the working fluid, while the efficiency decreases with the increase of specific heats of the working fluid. The friction loss has a negative effect on the performance. Therefore, the power output and efficiency of the cycle decrease with increasing friction loss. It is noteworthy that the effects of heat loss characterized by a percentage of the fuel's energy, friction and variable specific heats of the working fluid on the performance of an Otto cycle engine are significant and should be considered in practical cycle analysis. The results obtained in the present study are of importance to provide good guidance for performance evaluation and improvement of practical Otto engines

  1. Effects of entrance configuration on pressure loss and heat transfer of transitional gas flow in a circular tube

    International Nuclear Information System (INIS)

    Ogawa, Masuro; Kawamura, Hiroshi

    1986-01-01

    Pressure loss and heat transfer of a transitional gas flow are affected significantly by the entrance configuration. The friction factor and the heat transfer coefficient were measured using a circular tube with four different kinds of entrance configurations. The Reynolds number at the transition from laminar to intermittent flow was varied from about 1,940 to 9,120. The intermittency factor was measured for heated and unheated flows ; and the relation between the intermittency and the friction factor or heat transfer coefficient was examined. Several existing correlations were tested and found to correlate with the experimental results fairly well. (author)

  2. Comparison of thermoregulatory responses to heat between Malaysian and Japanese males during leg immersion

    Science.gov (United States)

    Wijayanto, Titis; Wakabayashi, Hitoshi; Lee, Joo-Young; Hashiguchi, Nobuko; Saat, Mohamed; Tochihara, Yutaka

    2011-07-01

    The objective of this study was to investigate thermoregulatory responses to heat in tropical (Malaysian) and temperate (Japanese) natives, during 60 min of passive heating. Ten Japanese (mean ages: 20.8 ± 0.9 years) and ten Malaysian males (mean ages: 22.3 ± 1.6 years) with matched morphological characteristics and physical fitness participated in this study. Passive heating was induced through leg immersion in hot water (42°C) for 60 min under conditions of 28°C air temperature and 50% RH. Local sweat rate on the forehead and thigh were significantly lower in Malaysians during leg immersion, but no significant differences in total sweat rate were observed between Malaysians (86.3 ± 11.8 g m-2 h-1) and Japanese (83.2 ± 6.4 g m-2 h-1) after leg immersion. In addition, Malaysians displayed a smaller rise in rectal temperature (0.3 ± 0.1°C) than Japanese (0.7 ± 0.1°C) during leg immersion, with a greater increase in hand skin temperature. Skin blood flow was significantly lower on the forehead and forearm in Malaysians during leg immersion. No significant different in mean skin temperature during leg immersion was observed between the two groups. These findings indicated that regional differences in body sweating distribution might exist between Malaysians and Japanese during heat exposure, with more uniform distribution of local sweat rate over the whole body among tropical Malaysians. Altogether, Malaysians appear to display enhanced efficiency of thermal sweating and thermoregulatory responses in dissipating heat loss during heat loading. Thermoregulatory differences between tropical and temperate natives in this study can be interpreted as a result of heat adaptations to physiological function.

  3. Complex effects of ecosystem engineer loss on benthic ecosystem response to detrital macroalgae

    NARCIS (Netherlands)

    Rossi, F.; Gribsholt, B.; Gazeau, F.; Di Santo, V.; Middelburg, J.J.

    2013-01-01

    Ecosystem engineers change abiotic conditions, community assembly and ecosystem functioning. Consequently, their loss may modify thresholds of ecosystem response to disturbance and undermine ecosystem stability. This study investigates how loss of the bioturbating lugworm Arenicola marina modifies

  4. Complex Effects of Ecosystem Engineer Loss on Benthic Ecosystem Response to Detrital Macroalgae

    NARCIS (Netherlands)

    Rossi, F.; Gribsholt, B.; Gazeau, F.; Di Santo, V.; Middelburg, J.J.

    2013-01-01

    Ecosystem engineers change abiotic conditions, community assembly and ecosystem functioning. Consequently, their loss may modify thresholds of ecosystem response to disturbance and undermine ecosystem stability. This study investigates how loss of the bioturbating lugworm Arenicola marina modifies

  5. Future Earth: Reducing Loss By Automating Response to Earthquake Shaking

    Science.gov (United States)

    Allen, R. M.

    2014-12-01

    Earthquakes pose a significant threat to society in the U.S. and around the world. The risk is easily forgotten given the infrequent recurrence of major damaging events, yet the likelihood of a major earthquake in California in the next 30 years is greater than 99%. As our societal infrastructure becomes ever more interconnected, the potential impacts of these future events are difficult to predict. Yet, the same inter-connected infrastructure also allows us to rapidly detect earthquakes as they begin, and provide seconds, tens or seconds, or a few minutes warning. A demonstration earthquake early warning system is now operating in California and is being expanded to the west coast (www.ShakeAlert.org). In recent earthquakes in the Los Angeles region, alerts were generated that could have provided warning to the vast majority of Los Angelinos who experienced the shaking. Efforts are underway to build a public system. Smartphone technology will be used not only to issue that alerts, but could also be used to collect data, and improve the warnings. The MyShake project at UC Berkeley is currently testing an app that attempts to turn millions of smartphones into earthquake-detectors. As our development of the technology continues, we can anticipate ever-more automated response to earthquake alerts. Already, the BART system in the San Francisco Bay Area automatically stops trains based on the alerts. In the future, elevators will stop, machinery will pause, hazardous materials will be isolated, and self-driving cars will pull-over to the side of the road. In this presentation we will review the current status of the earthquake early warning system in the US. We will illustrate how smartphones can contribute to the system. Finally, we will review applications of the information to reduce future losses.

  6. A assessment of loss-of-heat-sink accident with scram in the LMFBR

    International Nuclear Information System (INIS)

    Bari, R.A.; Ludewig, H.; Pratt, W.T.; Sun, Y.H.

    1978-01-01

    A description of a slow core meltdown in a liquid metal fast breeder reactor is presented for conditions of loss-of-heat-sink following neutronic shutdown. Simple models are developed for the prediction of phase changes and/or relocation of the core materials including fuel, clad, ducts, control rod absorber material (B 4 C), and plenum gases. The sequence of events is accounted for and the accident progression is described up to the point of recriticality. The neutronic behavior of the disrupted core is analyzed in R-Z geometry with a static transport theory code. For most scenarios assessed, the reactor is expected to become recritical although large ramp rates are not anticipated. (author)

  7. Assessment of the loss-of-heat-sink accident with scram in the LMFBR

    International Nuclear Information System (INIS)

    Bari, R.A.; Ludewig, H.; Pratt, W.T.; Sun, Y.H.

    1978-01-01

    A description of a slow core meltdown in a liquid metal fast breeder reactor is presented for the conditions of loss-of-heat-sink following neutronic shutdown. Simple models are developed for the prediction of phase changes and/or relocation of the core materials including fuel, clad, ducts, control rod absorber material (B 4 C), and plenum gases. The sequence of events is accounted for and the accident progression is described up to the point of recriticality. The neutronic behavior of the disrupted core is analyzed in R-Z geometry with a static transport theory code. For most scenarios assessed, the reactor is expected to become recritical although large ramp rates are not anticipated

  8. Comparative study of beam losses and heat loads reduction methods in MITICA beam source

    Energy Technology Data Exchange (ETDEWEB)

    Sartori, E., E-mail: emanuele.sartori@igi.cnr.it; Agostinetti, P.; Dal Bello, S.; Marcuzzi, D.; Serianni, G.; Veltri, P. [Consorzio RFX, Euratom-ENEA association, C.so Stati Uniti 4, 35127 Padova (Italy); Sonato, P. [Consorzio RFX, Euratom-ENEA association, C.so Stati Uniti 4, 35127 Padova (Italy); Dipartimento di Ingegneria Elettrica, Padova University, Via Gradenigo 6/a, 35131 Padova (Italy)

    2014-02-15

    In negative ion electrostatic accelerators a considerable fraction of extracted ions is lost by collision processes causing efficiency loss and heat deposition over the components. Stripping is proportional to the local density of gas, which is steadily injected in the plasma source; its pumping from the extraction and acceleration stages is a key functionality for the prototype of the ITER Neutral Beam Injector, and it can be simulated with the 3D code AVOCADO. Different geometric solutions were tested aiming at the reduction of the gas density. The parameter space considered is limited by constraints given by optics, aiming, voltage holding, beam uniformity, and mechanical feasibility. The guidelines of the optimization process are presented together with the proposed solutions and the results of numerical simulations.

  9. Mitigation Measures Following a Loss-of-Residual-Heat-Removal Event During Shutdown

    International Nuclear Information System (INIS)

    Seul, Kwang Won; Bang, Young Seok; Kim, Hho Jung

    2000-01-01

    The transient following a loss-of-residual-heat-removal event during shutdown was analyzed to determine the containment closure time (CCT) to prevent uncontrolled release of fission products and the gravity-injection path and rate (GIPR) for effective core cooling using the RELAP5/MOD3.2 code. The plant conditions of Yonggwang Units 3 and 4, a pressurized water reactor (PWR) of 2815-MW(thermal) power in Korea, were reviewed, and possible event sequences were identified. From the CCT analysis for the five cases of typical plant configurations, it was estimated for the earliest CCT to be 40 min after the event in a case with a large cold-leg opening and emptied steam generators (SGs). However, the case with water-filled SGs significantly delayed the CCT through the heat removal to the secondary side. From the GIPR analysis for the six possible gravity-injection paths from the refueling water storage tank (RWST), the case with the injection point and opening on the other leg side was estimated to be the most suitable path to avoid core boiling. In addition, from the sensitivity study, it was evaluated for the plant to be capable of providing the core cooling for the long-term transient if nominal RWST water is available. As a result, these analysis methods and results will provide useful information in understanding the plant behavior and preparing the mitigation measures after the event, especially for Combustion Engineering-type PWR plants. However, to directly apply the analysis results to the emergency procedure for such an event, additional case studies are needed for a wide range of operating conditions such as reactor coolant inventory, RWST water temperature, and core decay heat rate

  10. Free convective heat loss from cavity-type solar furnace; Solar receiver kara no shizen tairyu ni yoru netsusonshitsu

    Energy Technology Data Exchange (ETDEWEB)

    Fujii, I; Ito, N [Meiji University, Tokyo (Japan)

    1996-10-27

    Free convective heat loss from solar heat receivers was studied, using three laboratory model receivers (different in depth L and aperture diameter d) heated by electric heaters. Most of the heat produced by heaters was transmitted to the air inside. The cylindrical vessel walls were fully insulated against heat. Heat loss being supposed to result mainly from transfer by free convection, the experiment results were edited by use of Nusselt number Nu and Rayley number Ra. Relations between Nu(D/d){sup m1} and Ra(L/D){sup m2} were plotted in a chart. Here, D is the receiver inner diameter, and m1 and m2 are constants that can be determined by computation. Tests points were provided approximately lineally, irrespective of D, L, or receiver inclination. Air currents were found to produce one or more swirls inside, thanks to the current visualization technique, when the receiver inclination was not sharper than 120{degree} (except 0{degree}). The number of swirls increased as the inner wall temperature rose. This kind of behavior of air currents directly affects the degree of heat loss. 9 refs., 4 figs.

  11. Transcriptome analysis provides insights into hepatic responses to moderate heat stress in the rainbow trout (Oncorhynchus mykiss).

    Science.gov (United States)

    Li, Yongjuan; Huang, Jinqiang; Liu, Zhe; Zhou, Yanjing; Xia, Binpeng; Wang, Yongjie; Kang, Yujun; Wang, Jianfu

    2017-07-01

    The rainbow trout is an economically important fish in the world. The limited stress tolerance of this species to high summer-like temperatures usually leads to mass mortality and great economic loss. However, there is limited information on the mechanisms underlying moderate heat responses in the liver of the rainbow trout. Here, we performed transcriptome profiling of rainbow trout liver under moderate heat stress by using the Hiseq™ 4000 sequencing platform. More than 277 million clean reads were obtained from 6 libraries and aligned against the rainbow trout genome. A total of 128 unique transcripts were differentially expressed in the liver under heat-stress and control conditions, many heat shock protein genes for thermoregulation and some novel genes involved in heat stress were identified. Nine of the differently expressed genes were further validated by qRT-PCR. Gene ontology and Kyoto Encyclopedia of Genes and Genomes analyses revealed that several pathways, including those for protein metabolism, energy metabolism, and immune system, were influenced by heat stress. Moreover, an important protein-processing pathway in the endoplasmic reticulum (ER) was identified, and the key role of ER-associated degradation and function of calpain as an upstream regulator of apoptosis were confirmed under heat stress. The results of this study provide a comprehensive overview of heat stress-induced transcriptional patterns in rainbow trout liver and would be particularly useful for further studies on the molecular mechanisms underlying responses to heat stress in this species. Copyright © 2017. Published by Elsevier B.V.

  12. Biodiversity losses and conservation responses in the Anthropocene.

    Science.gov (United States)

    Johnson, Christopher N; Balmford, Andrew; Brook, Barry W; Buettel, Jessie C; Galetti, Mauro; Guangchun, Lei; Wilmshurst, Janet M

    2017-04-21

    Biodiversity is essential to human well-being, but people have been reducing biodiversity throughout human history. Loss of species and degradation of ecosystems are likely to further accelerate in the coming years. Our understanding of this crisis is now clear, and world leaders have pledged to avert it. Nonetheless, global goals to reduce the rate of biodiversity loss have mostly not been achieved. However, many examples of conservation success show that losses can be halted and even reversed. Building on these lessons to turn the tide of biodiversity loss will require bold and innovative action to transform historical relationships between human populations and nature. Copyright © 2017, American Association for the Advancement of Science.

  13. Adaptive response in Drosophila melanogaster heat shock proteins mutant strains

    International Nuclear Information System (INIS)

    Shaposhnikov, M.V.; Moskalev, A.A.; Turysheva, E.V.

    2007-01-01

    Complete text of publication follows. The members of the heat shock proteins (Hsp) family function as molecular chaperones and assist intracellular folding of newly synthesized proteins. Also it is possible that molecular chaperones are induced during adaptive response to oxidative stress and radiation. The aim of our research was to exam the role of heat shock proteins in adaptive response to oxidative stress after low dose rate gamma-irradiation in Drosophila melanogaster. Drosophilamelanogaster strains were kindly provided by Bloomington Drosophila Stock Center (University of state of Indiana, Bloomington, USA). We used wild type strain (CS), heat shock protein mutant strains (Hsp22, Hsp70, Hsp83), and heat shock factor mutant strain (Hsf). Strains were chronically exposured to adaptive dose of gamma-irradiation in dose rate of 0.17 cGy/h during all stages of life history (from the embrional stage to the stage of matured imago). The rate of absorbed dose was 60 cGy. For oxidative-stress challenge twodays old flies were starved in empty vials for 6 h and then transferred to vials containing only filter paper soaked with 20 mM paraquat in 5% sucrose solution. Survival data were collected after 26 h of treatment. Dead flies were counted daily. The obtained data were subjected to survival analysis by Kaplan and Meier method and presented as survival curves. Statistical analysis was held by non-parametric methods. To test the significance of the difference between the two age distributions Kolmogorov-Smirnov test was applied. Gehan-Braslow- Wilcoxon and Cox-Mantel tests were used for estimation of median life span differences. In addition the minimal and maximal life span, time of 90% death, and mortality rate doubling time (MRDT) were estimated. The obtained results will be discussed in presentation.

  14. In-vessel natural circulation during a hypothetical loss-of-heat-sink accident in the Fast Flux Test Facility

    International Nuclear Information System (INIS)

    Perkins, K.R.; Bari, R.A.; Pratt, W.T.

    1979-05-01

    The capability to remove decay heat from the FFTF core via in-vessel natural circulation has been analyzed for the preboiling phase using a lumped parameter model. The results indicate that boiling will occur in the average fuel assembly for a wide spectrum of initial conditions which appear to be representative of the hypothetical loss-of-heat-sink accident. Two-phase pressure drop calculations indicate that, once the saturation temperature is reached, coolability can only be assured for decay heat levels which are less than 0.5% of the operating power. A review of the limited sodium boiling data indicates that boiling-induced natural circulation may support up to 4% of the operating power, but geometric atypicalities and a large degree of inlet subcooling for the existing data limit the applicability to the loss-of-heat-sink accident in FFTF

  15. Assessment of Coping Capability of KORI Unit 1 under Extended Loss AC Power and Loss of Ultimate Heat Sink Initiated by Beyond Design Natural Disaster

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Chang Hyun; Ha, Sang Jun [KHNP CRI, Daejeon (Korea, Republic of); Han, Kee Soo [Nuclear Engineering Service and Solution (NESS) Co. Ltd., Deajeon (Korea, Republic of); Park, Chan Eok [KEPCO Engineering and Constructd., Deajeon (Korea, Republic of)

    2016-10-15

    In Korea, the government and industry performed comprehensive safety inspection on all domestic nuclear power plants against beyond design basis external events and fifty action items have been issued. In addition to post- Fukushima action items, the stress tests for all domestic nuclear power plants are on the way to enhance the safety of domestic nuclear power plants through finding the vulnerabilities in intentional stress conditions initiated by beyond design natural disaster. This paper presents assessment results of coping capability of KORI Unit 1 under the simultaneous Extended Loss of AC Power (ELAP) and Loss of Ultimate Heat Sink (LUHS) which is a representative plant condition initiated by beyond design natural disaster. The assessment of the coping capability of KORI Unit 1 has been performed under simultaneous the extended loss of AC power and loss of ultimate heat sink initiated by beyond design natural disaster. It is concluded that KORI Unit 1 has the capability, in the event of loss of safety functions by beyond design natural disaster, to sufficiently cool down the reactor core without fuel damage, to keep pressure boundaries of the reactor coolant system in transient condition and to control containment and temperature to maintain the integrity of the containment buildings.

  16. Assessment of Coping Capability of KORI Unit 1 under Extended Loss AC Power and Loss of Ultimate Heat Sink Initiated by Beyond Design Natural Disaster

    International Nuclear Information System (INIS)

    Kim, Chang Hyun; Ha, Sang Jun; Han, Kee Soo; Park, Chan Eok

    2016-01-01

    In Korea, the government and industry performed comprehensive safety inspection on all domestic nuclear power plants against beyond design basis external events and fifty action items have been issued. In addition to post- Fukushima action items, the stress tests for all domestic nuclear power plants are on the way to enhance the safety of domestic nuclear power plants through finding the vulnerabilities in intentional stress conditions initiated by beyond design natural disaster. This paper presents assessment results of coping capability of KORI Unit 1 under the simultaneous Extended Loss of AC Power (ELAP) and Loss of Ultimate Heat Sink (LUHS) which is a representative plant condition initiated by beyond design natural disaster. The assessment of the coping capability of KORI Unit 1 has been performed under simultaneous the extended loss of AC power and loss of ultimate heat sink initiated by beyond design natural disaster. It is concluded that KORI Unit 1 has the capability, in the event of loss of safety functions by beyond design natural disaster, to sufficiently cool down the reactor core without fuel damage, to keep pressure boundaries of the reactor coolant system in transient condition and to control containment and temperature to maintain the integrity of the containment buildings

  17. Tissue responses to fractional transient heating with sinusoidal heat flux condition on skin surface.

    Science.gov (United States)

    Ezzat, Magdy A; El-Bary, Alaa A; Al-Sowayan, Noorah S

    2016-10-01

    A fractional model of Bioheat equation for describing quantitatively the thermal responses of skin tissue under sinusoidal heat flux conditions on skin surface is given. Laplace transform technique is used to obtain the solution in a closed form. The resulting formulation is applied to one-dimensional application to investigate the temperature distribution in skin with instantaneous surface heating for different cases. According to the numerical results and its graphs, conclusion about the fractional bioheat transfer equation has been constructed. Sensitivity analysis is performed to explore the thermal effects of various control parameters on tissue temperature. The comparisons are made with the results obtained in the case of the absence of time-fractional order. © 2016 Japanese Society of Animal Science. © 2016 Japanese Society of Animal Science.

  18. Magnetic flux and heat losses by diffusive, advective, and Nernst effects in MagLIF-like plasma

    International Nuclear Information System (INIS)

    Velikovich, A. L.; Giuliani, J. L.; Zalesak, S. T.

    2014-01-01

    The MagLIF approach to inertial confinement fusion involves subsonic/isobaric compression and heating of a DT plasma with frozen-in magnetic flux by a heavy cylindrical liner. The losses of heat and magnetic flux from the plasma to the liner are thereby determined by plasma advection and gradient-driven transport processes, such as thermal conductivity, magnetic field diffusion and thermomagnetic effects. Theoretical analysis based on obtaining exact self-similar solutions of the classical collisional Braginskii's plasma transport equations in one dimension demonstrates that the heat loss from the hot plasma to the cold liner is dominated by the transverse heat conduction and advection, and the corresponding loss of magnetic flux is dominated by advection and the Nernst effect. For a large electron Hall parameter ω e τ e effective diffusion coefficients determining the losses of heat and magnetic flux are both shown to decrease with ω e τ e as does the Bohm diffusion coefficient, which is commonly associated with low collisionality and two-dimensional transport. This family of exact solutions can be used for verification of codes that model the MagLIF plasma dynamics

  19. Latent heat loss and sweat gland histology of male goats in an equatorial semi-arid environment

    Science.gov (United States)

    de Melo Costa, Cíntia Carol; Maia, Alex Sandro Campos; Neto, José Domingues Fontenele; Oliveira, Steffan Edward Octávio; de Queiroz, João Paulo Araújo Fernandes

    2014-03-01

    The objective of this work was to quantify the heat loss by cutaneous evaporation of goats in an equatorial semi-arid environment. The latent heat loss from the body surfaces of these ten undefined breed goats was measured using a ventilated capsule in sun and shade and in the three body regions (neck, flank and hindquarters). Skin samples from these three regions were histologically analyzed to relate the quantity of sweat glands, the area of sweat glands and the epithelium thickness of each of these regions to the heat loss by cutaneous evaporation of the examined goats. The epithelium thickness that was measured varied significantly for body regions with different quantities and areas of sweat glands ( P < 0.01). Among the body regions that were examined, the samples from the neck demonstrated the highest epithelium thickness (16.23 ± 0.13 μm). However, the samples of sweat glands from the flank had the biggest area (43330.51 ± 778.71 μm2) and quantity per square centimeter (390 ± 9 cm-2). After the animals were exposed to sun, the flanks lost the greatest amount of heat by cutaneous evaporation (73.03 ± 1.75 W m-2) and possessed the highest surface temperatures (39.47 ± 0.18 °C). The histological characteristics may have influenced the heat loss by cutaneous evaporation that was observed in the flank region after the animals were exposed to sun.

  20. First and Second-Law Efficiency Analysis and ANN Prediction of a Diesel Cycle with Internal Irreversibility, Variable Specific Heats, Heat Loss, and Friction Considerations

    Directory of Open Access Journals (Sweden)

    M. M. Rashidi

    2014-04-01

    Full Text Available The variability of specific heats, internal irreversibility, heat and frictional losses are neglected in air-standard analysis for different internal combustion engine cycles. In this paper, the performance of an air-standard Diesel cycle with considerations of internal irreversibility described by using the compression and expansion efficiencies, variable specific heats, and losses due to heat transfer and friction is investigated by using finite-time thermodynamics. Artificial neural network (ANN is proposed for predicting the thermal efficiency and power output values versus the minimum and the maximum temperatures of the cycle and also the compression ratio. Results show that the first-law efficiency and the output power reach their maximum at a critical compression ratio for specific fixed parameters. The first-law efficiency increases as the heat leakage decreases; however the heat leakage has no direct effect on the output power. The results also show that irreversibilities have depressing effects on the performance of the cycle. Finally, a comparison between the results of the thermodynamic analysis and the ANN prediction shows a maximum difference of 0.181% and 0.194% in estimating the thermal efficiency and the output power. The obtained results in this paper can be useful for evaluating and improving the performance of practical Diesel engines.

  1. Improving the Material Response for Slow Heat of Energetic Materials

    Energy Technology Data Exchange (ETDEWEB)

    Nichols, A L

    2010-03-08

    The goal of modern high explosive slow heat cookoff modeling is to understand the level of mechanical violence. This requires understanding the coupled thermal-mechanical-chemical system that such an environment creates. Recent advances have improved our ability to predict the time to event, and we have been making progress on predicting the mechanical response. By adding surface tension to the product gas pores in the high explosive, we have been able to reduce the current model's tendency to overpressurize confinement vessels. We describe the model and demonstrate how it affects a LX-10 STEX experiment. Issues associated with current product gas equations of state are described and examined.

  2. Assessment of prism responses to loss of flow events

    International Nuclear Information System (INIS)

    Slovik, G.C.; Van Tuyle, G.J.; Sands, S.

    1992-01-01

    The Nuclear Regulatory Commission (NRC), with Brookhaven national Laboratory providing technical support, is continuing a preapplication review of the 471 MWt, advanced liquid metal reactor (ALMR), PRISM by General Electric. The revised design has been evaluated using the SSC code, for a series of loss of flow events (LOF) with and without gas expansion modules (GEMs). These devices have a net worth of 69 cents and have reduced the seriousness of the LOF in PRISM. However, it was found that the extremely low probability case of an instantaneous loss of 4 EM pumps without scram could lead to sodium boiling even with the GEMs

  3. Terrestrial Ecosystem Responses to Species Gains and Losses

    NARCIS (Netherlands)

    Wardle, D.A.; Bardgett, R.D.; Callaway, R.; Putten, van der W.H.

    2011-01-01

    Ecosystems worldwide are losing some species and gaining others, resulting in an interchange of species that is having profound impacts on how these ecosystems function. However, research on the effects of species gains and losses has developed largely independently of one another. Recent conceptual

  4. Terrestrial ecosystem responses to species gains and losses

    NARCIS (Netherlands)

    Wardle, D.A.; Bardgett, R.D.; Callaway, R.M.; Van der Putten, W.H.

    2011-01-01

    Ecosystems worldwide are losing some species and gaining others, resulting in an interchange of species that is having profound impacts on how these ecosystems function. However, research on the effects of species gains and losses has developed largely independently of one another. Recent conceptual

  5. Numerical analysis of the effects of radiation heat transfer and ionization energy loss on the cavitation Bubble's dynamics

    International Nuclear Information System (INIS)

    Mahdi, M.; Ebrahimi, R.; Shams, M.

    2011-01-01

    A numerical scheme for simulating the acoustic and hydrodynamic cavitation was developed. Bubble instantaneous radius was obtained using Gilmore equation which considered the compressibility of the liquid. A uniform temperature was assumed for the inside gas during the collapse. Radiation heat transfer inside the bubble and the heat conduction to the bubble was considered. The numerical code was validated with the experimental data and a good correspondence was observed. The dynamics of hydrofoil cavitation bubble were also investigated. It was concluded that the thermal radiation heat transfer rate strongly depended on the cavitation number, initial bubble radius and hydrofoil angle of attack. -- Highlights: → Heat transfer and ionization energy losses were analyzed in the cavitation bubble. → Radiation of hydrodynamic bubble was approximately equal to the black body. → Radiation heat transfer did not affect the bubble dynamic. → Conduction decreased the bubble pressure and increased the bubble temperature. → Ionization decreased the temperature and increased the pressure in the bubble.

  6. Global Analysis of Heat Shock Response in Desulfovibrio vulgaris Hildenborough.

    Energy Technology Data Exchange (ETDEWEB)

    Chhabra, S.R.; He, Q.; Huang, K.H.; Gaucher, S.P.; Alm, E.J.; He,Z.; Hadi, M.Z.; Hazen, T.C.; Wall, J.D.; Zhou, J.; Arkin, A.P.; Singh, A.K.

    2005-09-16

    Desulfovibrio vulgaris Hildenborough belongs to a class ofsulfate-reducing bacteria (SRB) and is found ubiquitously in nature.Given the importance of SRB-mediated reduction for bioremediation ofmetal ion contaminants, ongoing research on D. vulgaris has been in thedirection of elucidating regulatory mechanisms for this organism under avariety of stress conditions. This work presents a global view of thisorganism's response to elevated growth temperature using whole-celltranscriptomics and proteomics tools. Transcriptional response (1.7-foldchange or greater; Z>1.5) ranged from 1,135 genes at 15 min to 1,463genes at 120 min for a temperature up-shift of 13oC from a growthtemperature of 37oC for this organism and suggested both direct andindirect modes of heat sensing. Clusters of orthologous group categoriesthat were significantly affected included posttranslationalmodifications; protein turnover and chaperones (up-regulated); energyproduction and conversion (down-regulated), nucleotide transport,metabolism (down-regulated), and translation; ribosomal structure; andbiogenesis (down-regulated). Analysis of the genome sequence revealed thepresence of features of both negative and positive regulation whichincluded the CIRCE element and promoter sequences corresponding to thealternate sigma factors ?32 and ?54. While mechanisms of heat shockcontrol for some genes appeared to coincide with those established forEscherichia coli and Bacillus subtilis, the presence of unique controlschemes for several other genes was also evident. Analysis of proteinexpression levels using differential in-gel electrophoresis suggestedgood agreement with transcriptional profiles of several heat shockproteins, including DnaK (DVU0811), HtpG (DVU2643), HtrA (DVU1468), andAhpC (DVU2247). The proteomics study also suggested the possibility ofposttranslational modifications in the chaperones DnaK, AhpC, GroES(DVU1977), and GroEL (DVU1976) and also several periplasmic ABCtransporters.

  7. Heat transfer and loss by whole-body hyperthermia during severe lower-body heating are impaired in healthy older men.

    Science.gov (United States)

    Brazaitis, Marius; Paulauskas, Henrikas; Eimantas, Nerijus; Obelieniene, Diana; Baranauskiene, Neringa; Skurvydas, Albertas

    2017-10-01

    Most studies demonstrate that aging is associated with a weakened thermoregulation. However, it remains unclear whether heat transfer (for heat loss) from the lower (uncompensable) to the upper (compensable) body during passively-induced severe lower-body heating is delayed or attenuated with aging. Therefore, the main purpose of this study was to investigate heat transfer from uncompensable to compensable body areas in young men and healthy older men during passively-induced whole-body hyperthermia with a demonstrated post-heating change in core body (rectal; T re ) temperature. Nine healthy older men and eleven healthy young men (69±6 vs. 21±1 years old, mean±SD, Pheating in water at approximately 43°C. Despite a similar increment in T re (approximately 2.5°C) in both groups, the heating rate was significantly lower in older men than in young men (1.69±0.12 vs. 2.47±0.29°C/h, respectively; Pheat in the skin and deep muscles than young men, and this was associated with a greater heat-transfer delay and subsequent inertia in the increased core body (T re ) temperature. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. No effects of acclimation to heat on immune and hormonal responses to passive heating in healthy volunteers

    Science.gov (United States)

    Kanikowska, Dominika; Sato, Maki; Sugenoya, Junichi; Iwase, Satoshi; Shimizu, Yuuki; Nishimura, Naoki; Inukai, Yoko

    2012-01-01

    Heat acclimation results in whole body-adaptations that increase heat tolerance, and might also result in changed immune responses. We hypothesized that, after heat acclimation, tumor necrosis factor alpha, interleukin 6 and the lymphocyte count would be altered. Heat acclimation was induced in 6 healthy men by 100 min of heat exposure for 9 days. Heat exposure consisted of (1) 10 min of immersion up to chest-level in water at 42°C and (2) 90 min of passive heating by a warm blanket to maintain tympanic temperature at 37.5°C. The climatic chamber was maintained at 40°C and a relative humidity of 50%. Blood samples were analyzed before and after heat acclimation for natural killer (NK) cell activity, counts of lymphocytes B and T, before and after heat acclimation for peripheral blood morphology, interleukin 6, tumor necrosis factor alpha, and cortisol. A Japanese version of the profile of mood states questionnaire was also administered before and after acclimation. The concentrations of white blood cells, lymphocytes B and T, cortisol, interleukin 6, tumor necrosis factor alpha and NK cell activity showed no significant differences between pre- and post-acclimation, but there was a significantly lower platelet count after acclimation and, with the profile of mood states questionnaire, there was a significant rise in anger after acclimation. It is concluded that heat acclimation by passive heating does not induce alterations in immune or endocrine responses.

  9. Tidal heating and mass loss in neutron star binaries - Implications for gamma-ray burst models

    Science.gov (United States)

    Meszaros, P.; Rees, M. J.

    1992-01-01

    A neutron star in a close binary orbit around another neutron star (or stellar-mass black hole) spirals inward owing to gravitational radiation. We discuss the effects of tidal dissipation during this process. Tidal energy dissipated in the neutron star's core escapes mainly as neutrinos, but heating of the crust, and outward diffusion of photons, blows off the outer layers of the star. This photon-driven mass loss precedes the final coalescence. The presence of this eject material impedes the escape of gamma-rays created via neutrino interactions. If an e(+) - e(-) fireball, created in the late stages of coalescence, were loaded with (or surrounded by) material with the mean column density of the ejecta, it could not be an efficient source of gamma-rays. Models for cosmologically distant gamma-rays burst that involve neutron stars must therefore be anisotropic, so that the fireball expands preferentially in directions where the column density of previously blown-off material is far below the spherically averaged value which we have calculated. Some possible 'scenarios' along these lines are briefly discussed.

  10. Loss of residual heat removal system: Diablo Canyon, Unit 2, April 10, 1987

    International Nuclear Information System (INIS)

    1987-06-01

    This report presents the findings of an NRC Augmented Inspection Team (AIT) investigation into the circumstances associated with the loss of residual heat removal (RHR) system capability for a period of approximately one and one-half hours at the Diablo Canyon, Unit 2 reactor facility on April 10, 1987. This event occurred while the Diablo Canyon, Unit 2, a pressurized water reactor, was shutdown with the reactor coolant system (RCS) water level drained to approximately mid-level of the hot leg piping. The reactor containment building equipment hatch was removed at the time of the event, and plant personnel were in the process of removing the primary side manways to gain access into the steam generator channel head areas. Thus, two fission product barriers were breached throughout the event. The RCS temperature increased from approximately 87 0 F to bulk boiling conditions without RCS temperature indication available to the plant operators. The RCS was subsequently pressurized to approximately 7 to 10 psig. The NRC AIT members concluded that the Diablo Canyon, Unit 2 plant was, at the time of the event, in a condition not previously analyzed by the NRC staff. The AIT findings from this event appear significant and generic to other pressurized water reactor facilities licensed by the NRC

  11. Modeling of Transient Response of the Wickless Heat Pipes

    International Nuclear Information System (INIS)

    Hussien, A.K.A.

    2013-01-01

    Thermosyphons transient response for startup from ambient temperature to steady state until shutdown conditions, is considered a stringent necessity for applications such as electronic, solar, geothermal and even nuclear reactors safety systems. This typically returns to the need to keep the temperature within certain limits before reaching critical conditions. A simple network model is derived for describing the transient response of closed two-phase thermosyphon (CTPT) at startup and shutdown states. In addition, for predicting the effect of operational characteristics of water/copper closed two-phase thermosyphon such as thermal load, filling ratio, evaporator length, and thermosyphon tube diameter. The thermosyphons operation was considered a thermal network of various components with different thermal resistances and dynamic responses. The network model consists of six sub-models. These models are pure conduction in walls of evaporator, adiabatic and condenser, and convection in evaporator pool, evaporator film, and condenser film. So, an energy balance for each sub-model was done to estimate temperatures, heat transfer coefficients, thermal resistances, time constant, and other thermal characteristics that describe the required transient response of the closed two-phase thermosyphon. Governing equations of the transient thermosyphon behavior can be simplified into a set of first-order linear ordinary differential equations. The Runge-Kutta method can be used to obtain transient thermosyphon temperatures from these equations.

  12. Demand response offered by households with direct electric heating

    International Nuclear Information System (INIS)

    Kofod, C.; Togeby, M.

    2004-01-01

    The peak power balance in the Nordic power system is gradually turning to be very tight, especially in the electric area of southern Sweden and eastern Denmark. Power stations are closed and hardly any investments in new production are carried out. Demand response is considered essential when the formation of spot prices shall send the signal of needed investments in new capacity. Demand response which are based on individual preferences, and carried out automatically, can be one way to increase the volume of price elastic demand. Demand response need hourly metering for calculation and documentation of the decrease in demand, and controllability in order to meet the timing requirements. Within the EU SAVE project EFFLOCOM (2002 - 2004), a Danish demand response pilot project was established in 2003 including 25 single family homes with direct electrical heating. The system has been tested during the winter 2003/2004. The tested technologies include hourly metering, communication by GRPS as well as the Internet. GPRS is used for daily remote meter reading and automatic control of the electric heating including individual control of up to five zones. The system is designed for automatic activation when the Nord Pool hourly Elspot prices exceed preset levels. The system can also be used as regulating power. The EFFLOCOM Web Bite includes an interactive demonstrator of the system. The developed customer Web Bite is including the services: 1) Access to setting the limits for the maximum duration of interruption for up to five different control zones for two periods of the day and for three price levels. 2) Access to stop an actual interruption. 3) A report on the hourly, daily, weekly and monthly use of electricity and the saved bonus by demand response control. The report is updated daily. The goals of up to 5 kW controlled per house were fulfilled. Besides the demand response bonus the customers have also saved electricity. A customer survey did show that the

  13. An Approximate Solution for Predicting the Heat Extraction and Preventing Heat Loss from a Closed-Loop Geothermal Reservoir

    Directory of Open Access Journals (Sweden)

    Bisheng Wu

    2017-01-01

    Full Text Available Approximate solutions are found for a mathematical model developed to predict the heat extraction from a closed-loop geothermal system which consists of two vertical wells (one for injection and the other for production and one horizontal well which connects the two vertical wells. Based on the feature of slow heat conduction in rock formation, the fluid flow in the well is divided into three stages, that is, in the injection, horizontal, and production wells. The output temperature of each stage is regarded as the input of the next stage. The results from the present model are compared with those obtained from numerical simulator TOUGH2 and show first-order agreement with a temperature difference less than 4°C for the case where the fluid circulated for 2.74 years. In the end, a parametric study shows that (1 the injection rate plays dominant role in affecting the output performance, (2 higher injection temperature produces larger output temperature but decreases the total heat extracted given a specific time, (3 the output performance of geothermal reservoir is insensitive to fluid viscosity, and (4 there exists a critical point that indicates if the fluid releases heat into or absorbs heat from the surrounding formation.

  14. SCDAP/RELAP5 modeling of fluid heat transfer and flow losses through porous debris in a light water reactor

    International Nuclear Information System (INIS)

    Harvego, E. A.; Siefken, L. J.

    2000-01-01

    The SCDAP/RELAP5 code is being developed at the Idaho National Engineering and Environmental Laboratory under the primary sponsorship of the U.S. Nuclear Regulatory Commission (NRC) to provide best-estimate transient simulations of light water reactor coolant systems during severe accidents. This paper describes the modeling approach used in the SCDAP/RELAP5 code to calculate fluid heat transfer and flow losses through porous debris that has accumulated in the vessel lower head and core regions during the latter stages of a severe accident. The implementation of heat transfer and flow loss correlations into the code is discussed, and calculations performed to assess the validity of the modeling approach are described. The different modes of heat transfer in porous debris include: (1) forced convection to liquid, (2) forced convection to gas, (3) nucleate boiling, (4) transition boiling, (5) film boiling, and (6) transition from film boiling to convection to vapor. The correlations for flow losses in porous debris include frictional and form losses. The correlations for flow losses were integrated into the momentum equations in the RELAP5 part of the code. Since RELAP5 is a very general non-homogeneous non-equilibrium thermal-hydraulics code, the resulting modeling methodology is applicable to a wide range of debris thermal-hydraulic conditions. Assessment of the SCDAP/RELAP5 debris bed thermal-hydraulic models included comparisons with experimental measurements and other models available in the open literature. The assessment calculations, described in the paper, showed that SCDAP/RELAP5 is capable of calculating the heat transfer and flow losses occurring in porous debris regions that may develop in a light water reactor during a severe accident

  15. Heat shock factor-1 modulates p53 activity in the transcriptional response to DNA damage

    Science.gov (United States)

    Logan, Ian R.; McNeill, Hesta V.; Cook, Susan; Lu, Xiaohong; Meek, David W.; Fuller-Pace, Frances V.; Lunec, John; Robson, Craig N.

    2009-01-01

    Here we define an important role for heat shock factor 1 (HSF1) in the cellular response to genotoxic agents. We demonstrate for the first time that HSF1 can complex with nuclear p53 and that both proteins are co-operatively recruited to p53-responsive genes such as p21. Analysis of natural and synthetic cis elements demonstrates that HSF1 can enhance p53-mediated transcription, whilst depletion of HSF1 reduces the expression of p53-responsive transcripts. We find that HSF1 is required for optimal p21 expression and p53-mediated cell-cycle arrest in response to genotoxins while loss of HSF1 attenuates apoptosis in response to these agents. To explain these novel properties of HSF1 we show that HSF1 can complex with DNA damage kinases ATR and Chk1 to effect p53 phosphorylation in response to DNA damage. Our data reveal HSF1 as a key transcriptional regulator in response to genotoxic compounds widely used in the clinical setting, and suggest that HSF1 will contribute to the efficacy of these agents. PMID:19295133

  16. Forest response to heat waves at the dry timberline

    Science.gov (United States)

    Yakir, D.; Rotenberg, E.; Tatrinov, F.; Ogee, J.; Maseyk, K.

    2012-04-01

    Predictions of climate change consistently indicate continuous warming and drying for the entire Mediterranean basin and other regions during the next century. Investigating forest functioning at the current dry and hot "timberline" has therefore implications for predicting future forest distribution. In such investigations we should consider the forest adjustments to extreme conditions both at the long-term average climate basis, as at the time-scale of episodic extreme events, such as heat waves and droughts. Investigating both aspects in a 45-yr old semi-arid pine forest at the dry timberline (MuSICA) was used to test our understandings of underlying processes, and our ability to account for such differential responses.

  17. Reactor coolant pump seal response to loss of cooling

    International Nuclear Information System (INIS)

    Graham, T.; Metcalfe, R.; Burchett, P.

    2000-01-01

    This paper describes the results of a test done to determine the performance of a reactor coolant pump seal for a water cooled nuclear reactor under loss of all cooling conditions. Under these conditions, seal faces can lose their liquid lubricating film and elastomers can rapidly degrade. Temperatures in the seal-cartridge tester reached 230 o C in three hours, at which time the tester was stopped and the temperature increased to 265 o C for a further five hours before cooling was restored. Seal leakage was 'normal' throughout the test. Parts sustained minor damage with no effect on seal integrity. Plant operators were shown to have ample margin beyond their 15 minute allowable reaction time. (author)

  18. Barcoding heat shock proteins to human diseases: looking beyond the heat shock response.

    Science.gov (United States)

    Kakkar, Vaishali; Meister-Broekema, Melanie; Minoia, Melania; Carra, Serena; Kampinga, Harm H

    2014-04-01

    There are numerous human diseases that are associated with protein misfolding and the formation of toxic protein aggregates. Activating the heat shock response (HSR)--and thus generally restoring the disturbed protein homeostasis associated with such diseases--has often been suggested as a therapeutic strategy. However, most data on activating the HSR or its downstream targets in mouse models of diseases associated with aggregate formation have been rather disappointing. The human chaperonome consists of many more heat shock proteins (HSPs) that are not regulated by the HSR, however, and researchers are now focusing on these as potential therapeutic targets. In this Review, we summarize the existing literature on a set of aggregation diseases and propose that each of them can be characterized or 'barcoded' by a different set of HSPs that can rescue specific types of aggregation. Some of these 'non-canonical' HSPs have demonstrated effectiveness in vivo, in mouse models of protein-aggregation disease. Interestingly, several of these HSPs also cause diseases when mutated--so-called chaperonopathies--which are also discussed in this Review.

  19. Analysis on the Role of RSG-GAS Pool Cooling System during Partial Loss of Heat Sink Accident

    Science.gov (United States)

    Susyadi; Endiah, P. H.; Sukmanto, D.; Andi, S. E.; Syaiful, B.; Hendro, T.; Geni, R. S.

    2018-02-01

    RSG-GAS is a 30 MW reactor that is mostly used for radioisotope production and experimental activities. Recently, it is regularly operated at half of its capacity for efficiency reason. During an accident, especially loss of heat sink, the role of its pool cooling system is very important to dump decay heat. An analysis using single failure approach and partial modeling of RELAP5 performed by S. Dibyo, 2010 shows that there is no significant increase in the coolant temperature if this system is properly functioned. However lessons learned from the Fukushima accident revealed that an accident can happen due to multiple failures. Considering ageing of the reactor, in this research the role of pool cooling system is to be investigated for a partial loss of heat sink accident which is at the same time the protection system fails to scram the reactor when being operated at 15 MW. The purpose is to clarify the transient characteristics and the final state of the coolant temperature. The method used is by simulating the system in RELAP5 code. Calculation results shows the pool cooling systems reduce coolant temperature for about 1 K as compared without activating them. The result alsoreveals that when the reactor is being operated at half of its rated power, it is still in safe condition for a partial loss of heat sink accident without scram.

  20. All fiber cladding mode stripper with uniform heat distribution and high cladding light loss manufactured by CO2 laser ablation

    Science.gov (United States)

    Jebali, M. A.; Basso, E. T.

    2018-02-01

    Cladding mode strippers are primarily used at the end of a fiber laser cavity to remove high-power excess cladding light without inducing core loss and beam quality degradation. Conventional manufacturing methods of cladding mode strippers include acid etching, abrasive blasting or laser ablation. Manufacturing of cladding mode strippers using laser ablation consist of removing parts of the cladding by fused silica ablation with a controlled penetration and shape. We present and characterize an optimized cladding mode stripper design that increases the cladding light loss with a minimal device length and manufacturing time. This design reduces the localized heat generation by improving the heat distribution along the device. We demonstrate a cladding mode stripper written on a 400um fiber with cladding light loss of 20dB, with less than 0.02dB loss in the core and minimal heating of the fiber and coating. The manufacturing process of the designed component is fully automated and takes less than 3 minutes with a very high throughput yield.

  1. Yeast culture increased plasma niacin concentration, evaporative heat loss, and feed efficiency of dairy cows in a hot environment.

    Science.gov (United States)

    Dias, Julia D L; Silva, Rayana B; Fernandes, Tatiane; Barbosa, Eugenio F; Graças, Larissa E C; Araujo, Rafael C; Pereira, Renata A N; Pereira, Marcos N

    2018-04-04

    The supplementation of dairy cows with yeast culture may increase diet digestibility, plasma niacin concentration, heat dissipation, and lactation performance. Our objective was to evaluate the response of Holstein cows in late lactation (234 ± 131 d in milk) to dead yeast culture (YC, 15 g/d, Factor SC, GRASP, Saccharomyces cerevisiae) during Brazilian summer (temperature-humidity index >68 for 92.2% of the time). Thirty-two cows were individually fed a standard total mixed ration for 14 d and control (CTL) or YC treatments for 35 d, in a covariate adjusted complete randomized block design. Response was evaluated in wk 5 or as repeated measures over time. Cows were milked 3 times per day and treatments (YC or placebo) were orally dosed to each cow before each milking. Plasma niacin was 1.50 for CTL and 1.66 µg/mL for YC. The YC reduced rectal temperature, respiration rate, and skin temperature, whereas it tended to increase sweating rate. The proportion of cows with rectal temperature ≥39.2°C on CTL and YC was, respectively, 8 and 0% at 0730 h, 52 and 25% at 1500 h, and 35 and 26% at 2200 h. Plasma glucose was increased by YC. The total-tract apparent digestibility of nutrients, plasma urea N concentration, molar proportion of ruminal VFA, and urinary allantoin excretion were not affected by YC. Cows fed YC were less selective against feed particles >19 mm in the morning, in the afternoon were more selective against long feed particles and in favor of particles loss, and feed efficiency of late lactation dairy cows by reducing intake at similar milk yield. Copyright © 2018 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  2. Thermal response test data of five quadratic cross section precast pile heat exchangers.

    Science.gov (United States)

    Alberdi-Pagola, Maria

    2018-06-01

    This data article comprises records from five Thermal Response Tests (TRT) of quadratic cross section pile heat exchangers. Pile heat exchangers, typically referred to as energy piles, consist of traditional foundation piles with embedded heat exchanger pipes. The data presented in this article are related to the research article entitled "Comparing heat flow models for interpretation of precast quadratic pile heat exchanger thermal response tests" (Alberdi-Pagola et al., 2018) [1]. The TRT data consists of measured inlet and outlet temperatures, fluid flow and injected heat rate recorded every 10 min. The field dataset is made available to enable model verification studies.

  3. Thermal response test data of five quadratic cross section precast pile heat exchangers

    Directory of Open Access Journals (Sweden)

    Maria Alberdi-Pagola

    2018-06-01

    Full Text Available This data article comprises records from five Thermal Response Tests (TRT of quadratic cross section pile heat exchangers. Pile heat exchangers, typically referred to as energy piles, consist of traditional foundation piles with embedded heat exchanger pipes. The data presented in this article are related to the research article entitled “Comparing heat flow models for interpretation of precast quadratic pile heat exchanger thermal response tests” (Alberdi-Pagola et al., 2018 [1]. The TRT data consists of measured inlet and outlet temperatures, fluid flow and injected heat rate recorded every 10 min. The field dataset is made available to enable model verification studies.

  4. Global-scale hydrological response to future glacier mass loss

    Science.gov (United States)

    Huss, Matthias; Hock, Regine

    2018-01-01

    Worldwide glacier retreat and associated future runoff changes raise major concerns over the sustainability of global water resources1-4, but global-scale assessments of glacier decline and the resulting hydrological consequences are scarce5,6. Here we compute global glacier runoff changes for 56 large-scale glacierized drainage basins to 2100 and analyse the glacial impact on streamflow. In roughly half of the investigated basins, the modelled annual glacier runoff continues to rise until a maximum (`peak water') is reached, beyond which runoff steadily declines. In the remaining basins, this tipping point has already been passed. Peak water occurs later in basins with larger glaciers and higher ice-cover fractions. Typically, future glacier runoff increases in early summer but decreases in late summer. Although most of the 56 basins have less than 2% ice coverage, by 2100 one-third of them might experience runoff decreases greater than 10% due to glacier mass loss in at least one month of the melt season, with the largest reductions in central Asia and the Andes. We conclude that, even in large-scale basins with minimal ice-cover fraction, the downstream hydrological effects of continued glacier wastage can be substantial, but the magnitudes vary greatly among basins and throughout the melt season.

  5. BOLD responses in somatosensory cortices better reflect heat sensation than pain.

    Science.gov (United States)

    Moulton, Eric A; Pendse, Gautam; Becerra, Lino R; Borsook, David

    2012-04-25

    The discovery of cortical networks that participate in pain processing has led to the common generalization that blood oxygen level-dependent (BOLD) responses in these areas indicate the processing of pain. Physical stimuli have fundamental properties that elicit sensations distinguishable from pain, such as heat. We hypothesized that pain intensity coding may reflect the intensity coding of heat sensation during the presentation of thermal stimuli during fMRI. Six 3T fMRI heat scans were collected for 16 healthy subjects, corresponding to perceptual levels of "low innocuous heat," "moderate innocuous heat," "high innocuous heat," "low painful heat," "moderate painful heat," and "high painful heat" delivered by a contact thermode to the face. Subjects rated pain and heat intensity separately after each scan. A general linear model analysis detected different patterns of brain activation for the different phases of the biphasic response to heat. During high painful heat, the early phase was associated with significant anterior insula and anterior cingulate cortex activation. Persistent responses were detected in the right dorsolateral prefrontal cortex and inferior parietal lobule. Only the late phase showed significant correlations with perceptual ratings. Significant heat intensity correlated activation was identified in contralateral primary and secondary somatosensory cortices, motor cortex, and superior temporal lobe. These areas were significantly more related to heat ratings than pain. These results indicate that heat intensity is encoded by the somatosensory cortices, and that pain evaluation may either arise from multimodal evaluative processes, or is a distributed process.

  6. Kids, candy, brain and behavior: Age differences in responses to candy gains and losses

    Directory of Open Access Journals (Sweden)

    Katherine R. Luking

    2014-07-01

    Full Text Available The development of reward-related neural systems, from adolescence through adulthood, has received much recent attention in the developmental neuroimaging literature. However, few studies have investigated behavioral and neural responses to both gains and losses in pre-pubertal child populations. To address this gap in the literature, in the present study healthy children aged 7–11 years and young-adults completed an fMRI card-guessing game using candy pieces delivered post-scan as an incentive. Age differences in behavioral and neural responses to candy gains/losses were investigated. Adults and children displayed similar responses to gains, but robust age differences were observed following candy losses within the caudate, thalamus, insula, and hippocampus. Interestingly, when task behavior was included as a factor in post hoc mediation analyses, activation following loss within the caudate/thalamus related to task behavior and relationships with age were no longer significant. Conversely, relationships between response to loss and age within the hippocampus and insula remained significant even when controlling for behavior, with children showing heightened loss responses within the dorsal/posterior insula. These results suggest that both age and task behavior influence responses within the extended reward circuitry, and that children seem to be more sensitive than adults to loss feedback particularly within the dorsal/posterior insula.

  7. Age Modulates Physiological Responses during Fan Use under Extreme Heat and Humidity.

    Science.gov (United States)

    Gagnon, Daniel; Romero, Steven A; Cramer, Matthew N; Kouda, Ken; Poh, Paula Y S; Ngo, Hai; Jay, Ollie; Crandall, Craig G

    2017-11-01

    We examined the effect of electric fan use on cardiovascular and thermoregulatory responses of nine young (26 ± 3 yr) and nine aged (68 ± 4 yr) adults exposed to extreme heat and humidity. While resting at a temperature of 42°C, relative humidity increased from 30% to 70% in 2% increments every 5 min. On randomized days, the protocol was repeated without or with fan use. HR, core (Tcore) and mean skin (Tsk) temperatures were measured continuously. Whole-body sweat loss was measured from changes in nude body weight. Other measures of cardiovascular (cardiac output), thermoregulatory (local cutaneous and forearm vascular conductance, local sweat rate), and perceptual (thermal and thirst sensations) responses were also examined. When averaged over the entire protocol, fan use resulted in a small reduction of HR (-2 bpm, 95% confidence interval [CI], -8 to 3), and slightly greater Tcore (+0.05°C; 95% CI, -0.13 to 0.23) and Tsk (+0.03°C; 95% CI, -0.36 to 0.42) in young adults. In contrast, fan use resulted in greater HR (+5 bpm; 95% CI, 0-10), Tcore (+0.20°C; 95% CI, 0.00-0.41), and Tsk (+0.47°C; 95% CI, 0.18-0.76) in aged adults. A greater whole-body sweat loss during fan use was observed in young (+0.2 kg; 95% CI, -0.2 to 0.6) but not aged (0.0 kg; 95% CI, -0.2 to 0.2) adults. Greater local sweat rate and cutaneous vascular conductance were observed with fan use in aged adults. Other measures of cardiovascular, thermoregulatory, and perceptual responses were unaffected by fan use in both groups. During extreme heat and humidity, fan use elevates physiological strain in aged, but not young, adults.

  8. Antioxidant responses to heat and light stress differ with habitat in a common reef coral

    Science.gov (United States)

    Hawkins, Thomas D.; Krueger, Thomas; Wilkinson, Shaun P.; Fisher, Paul L.; Davy, Simon K.

    2015-12-01

    Coral bleaching—the stress-induced collapse of the coral- Symbiodinium symbiosis—is a significant driver of worldwide coral reef degradation. Yet, not all corals are equally susceptible to bleaching, and we lack a clear understanding of the mechanisms underpinning their differential susceptibilities. Here, we focus on cellular redox regulation as a potential determinant of bleaching susceptibility in the reef coral Stylophora pistillata. Using slow heating (1 °C d-1) and altered irradiance, we induced bleaching in S. pistillata colonies sampled from two depths [5-8 m (shallow) and 15-18 m (deep)]. There was significant depth-dependent variability in the timing and extent of bleaching (loss of symbiont cells), as well as in host enzymatic antioxidant activity [specifically, superoxide dismutase and catalase (CAT)]. However, among the coral fragments that bleached, most did so without displaying any evidence of a host enzymatic antioxidant response. For example, both deep and shallow corals suffered significant symbiont loss at elevated temperature, but only deep colonies exposed to high temperature and high light displayed any up-regulation of host antioxidant enzyme activity (CAT). Surprisingly, this preceded the equivalent antioxidant responses of the symbiont, which raises questions about the source(s) of hydrogen peroxide in the symbiosis. Overall, changes in enzymatic antioxidant activity in the symbionts were driven primarily by irradiance rather than temperature, and responses were similar across depth groups. Taken together, our results suggest that in the absence of light stress, heating of 1 °C d-1 to 4 °C above ambient is not sufficient to induce a substantial oxidative challenge in S. pistillata. We provide some of the first evidence that regulation of coral enzymatic antioxidants can vary significantly depending on habitat, and, in terms of determining bleaching susceptibility, our results suggest a significant role for the host's differential

  9. Loss of Response to Melatonin Treatment Is Associated with Slow Melatonin Metabolism

    Science.gov (United States)

    Braam, W.; van Geijlswijk, I.; Keijzer, Henry; Smits, Marcel G.; Didden, Robert; Curfs, Leopold M. G.

    2010-01-01

    Background: In some of our patients with intellectual disability (ID) and sleep problems, the initial good response to melatonin disappeared within a few weeks after starting treatment, while the good response returned only after considerable dose reduction. The cause for this loss of response to melatonin is yet unknown. We hypothesise that this…

  10. Loss of response to melatonin treatment is associated with slow melatonin metabolism

    NARCIS (Netherlands)

    Braam, W.J.; Geijlswijk, I.M. van; Keijzer, H.; Smits, M.G.; Didden, H.C.M.; Curfs, L.M.G.

    2010-01-01

    Background In some of our patients with intellectual disability (ID) and sleep problems, the initial good response to melatonin disappeared within a few weeks after starting treatment, while the good response returned only after considerable dose reduction. The cause for this loss of response to

  11. Remarkable separability of circulation response to Arctic sea ice loss and greenhouse gas forcing

    Science.gov (United States)

    McCusker, K. E.; Kushner, P. J.; Fyfe, J. C.; Sigmond, M.; Kharin, V. V.; Bitz, C. M.

    2017-08-01

    Arctic sea ice loss may influence midlatitude climate by changing large-scale circulation. The extent to which climate change can be understood as greenhouse gas-induced changes that are modulated by this loss depends on how additive the responses to the separate influences are. A novel sea ice nudging methodology in a fully coupled climate model reveals that the separate effects of doubled atmospheric carbon dioxide (CO2) concentrations and associated Arctic sea ice loss are remarkably additive and insensitive to the mean climate state. This separability is evident in several fields throughout most of the year, from hemispheric to synoptic scales. The extent to which the regional response to sea ice loss sometimes agrees with and sometimes cancels the response to CO2 is quantified. The separability of the responses might provide a means to better interpret the diverse array of modeling and observational studies of Arctic change and influence.

  12. XML Survey of the productivity loss due to heat stress in different tasks of farmers in Darreh Shahr city

    Directory of Open Access Journals (Sweden)

    M. R. Monazzam Esmaielpou

    2015-09-01

    Full Text Available Introduction: Heat is one of the hazardous physical agents in the workplace. Exposure to heat and consequent thermal stress influence workers productivity in addition to adverse health effects. The aim of this study was to determine the heat stress induced productivity loss related to different tasks of farmers in Darreh Shahr city, during summer. Material and Method: This cross-sectional study was conducted in summer, 2014, among farmers in Darreh Shahr city. After determining the sample size, farmers’ activities were determined using hierarchical task analysis (HTA, and WBGT measurements were done according to the ISO7243. Metabolism was estimated by the ISO8996. Following, the type of activities were identified according their required metabolism. Knowing WBGT and workload and using the work capacity model, the productivity loss in different tasks and ultimately total productivity loss were calculated. Result: The mean WBGT activities for plowing, terracing, planting seeds, watering, fertilizing, weeding, spraying, and harvesting were 29.98 °C, 31.28 °C,30.66 °C,31.39 °C,31.99 °C,31.75 °C,31.08 °C, and 30.3 °C, respectively. WBGT values were higher than the permissible level provided by ISO7243 in all farming activities. Maximum value of WBGT was belonged to fertilizing activity (31.99 °C and the lowest value was for plowing (29.98 °C. ANOVA test results did not show a significant difference in WBGT at head, waist, and ankle height. The highest and lowest amount of productivity loss was estimated respectively for weeding and plowing activities. The total productivity loss for farming was calculated 69.3 percent in an hour which is due to high physical activity, working outdoor, with exposure to direct solar radiation, and consequent heat stress imposed to workers. Conclusion: Productivity is a factor which is affected by the workplace heat stress. According to results of the present research, the amount of productivity is reduced

  13. Survey of the productivity loss due to heat stress in different tasks of farmers in Darreh Shahr city

    Directory of Open Access Journals (Sweden)

    M. R. Monazzam Esmaielpour

    2015-09-01

    Full Text Available Introduction: Heat is one of the hazardous physical agents in the workplace. Exposure to heat and consequent thermal stress influence workers productivity in addition to adverse health effects. The aim of this study was to determine the heat stress induced productivity loss related to different tasks of farmers in Darreh Shahr city, during summer. . Material and Method: This cross-sectional study was conducted in summer, 2014, among farmers in Darreh Shahr city. After determining the sample size, farmers’ activities were determined using hierarchical task analysis (HTA, and WBGT measurements were done according to the ISO7243. Metabolism was estimated by the ISO8996. Following, the type of activities were identified according their required metabolism. Knowing WBGT and workload and using the work capacity model, the productivity loss in different tasks and ultimately total productivity loss were calculated. .Result: The mean WBGT activities for plowing, terracing, planting seeds, watering, fertilizing, weeding, spraying, and harvesting were 29.98 °C, 31.28 °C,30.66 °C,31.39 °C,31.99 °C,31.75 °C,31.08 °C, and 30.3 °C, respectively. WBGT values were higher than the permissible level provided by ISO7243 in all farming activities. Maximum value of WBGT was belonged to fertilizing activity (31.99 °C and the lowest value was for plowing (29.98 °C. ANOVA test results did not show a significant difference in WBGT at head, waist, and ankle height. The highest and lowest amount of productivity loss was estimated respectively for weeding and plowing activities. The total productivity loss for farming was calculated 69.3 percent in an hour which is due to high physical activity, working outdoor, with exposure to direct solar radiation, and consequent heat stress imposed to workers. .Conclusion: Productivity is a factor which is affected by the workplace heat stress. According to results of the present research, the amount of productivity is

  14. An effect of heat insulation parameters on thermal losses of water-cooled roofs for secondary steelmaking electric arc furnaces

    Directory of Open Access Journals (Sweden)

    E. Mihailov

    2016-07-01

    Full Text Available The aim of this work is research in the insulation parameters effect on the thermal losses of watercooled roofs for secondary steelmaking electric arc furnaces. An analytical method has been used for the investigation in heat transfer conditions in the working area. The results of the research can be used to choose optimal cooling parameters and select a suitable kind of insulation for water-cooled surfaces.

  15. Infrared thermography applied to the evaluation of metabolic heat loss of chicks fed with different energy densities

    Directory of Open Access Journals (Sweden)

    VMOS Ferreira

    2011-06-01

    Full Text Available Brazil must comply with international quality standards and animal welfare requirements in order to maintain its position as world's largest exporter of poultry meat. With the scenario of global climate change there is the forecast of occurrence of extreme events with characteristics of both excess cold and heat for several regions of the country. This study aimed to evaluate the effectiveness of using images of infrared thermography to evaluate the loss of sensible heat in young broilers fed different dietary energy levels. Twenty birds were reared in a house with appropriate brooding using infrared lamps. Birds were distributed in a completely randomized experimental into two treatments: T1 (control diet with 2950 kcal ME/kg-1, and T2 (high-energy diet with 3950 kcal ME/kg-1. Infrared thermographic images of the birds were recorded for four consecutive days. One bird was randomly chosen per treatment, and had special images taken and analyzed. Average surface temperature of the body area was calculated using the surface temperature recorded at 100 spots (50 at the front and 50 at the lateral side of the bird's body. Mean surface temperature of the flock was calculated recording 100 spots on the group of birds. Total radiant heat loss was calculated based on the average data of surface temperature. The results indicated that the young broilers fed the high-energy diet presented a metabolic energy loss equivalent to 0.64 kcal h-1, while the birds fed with the control diet lost 2.18 kcal h-1. This finding confirms that oil supplementation to the diet reduces bird heat loss. The infrared camera was able to record young broilers' surface temperature variation when birds were fed diets with different energy contents.

  16. A quick earthquake disaster loss assessment method supported by dasymetric data for emergency response in China

    Science.gov (United States)

    Xu, Jinghai; An, Jiwen; Nie, Gaozong

    2016-04-01

    Improving earthquake disaster loss estimation speed and accuracy is one of the key factors in effective earthquake response and rescue. The presentation of exposure data by applying a dasymetric map approach has good potential for addressing this issue. With the support of 30'' × 30'' areal exposure data (population and building data in China), this paper presents a new earthquake disaster loss estimation method for emergency response situations. This method has two phases: a pre-earthquake phase and a co-earthquake phase. In the pre-earthquake phase, we pre-calculate the earthquake loss related to different seismic intensities and store them in a 30'' × 30'' grid format, which has several stages: determining the earthquake loss calculation factor, gridding damage probability matrices, calculating building damage and calculating human losses. Then, in the co-earthquake phase, there are two stages of estimating loss: generating a theoretical isoseismal map to depict the spatial distribution of the seismic intensity field; then, using the seismic intensity field to extract statistics of losses from the pre-calculated estimation data. Thus, the final loss estimation results are obtained. The method is validated by four actual earthquakes that occurred in China. The method not only significantly improves the speed and accuracy of loss estimation but also provides the spatial distribution of the losses, which will be effective in aiding earthquake emergency response and rescue. Additionally, related pre-calculated earthquake loss estimation data in China could serve to provide disaster risk analysis before earthquakes occur. Currently, the pre-calculated loss estimation data and the two-phase estimation method are used by the China Earthquake Administration.

  17. Isolating the atmospheric circulation response to Arctic sea-ice loss in the coupled climate system

    Science.gov (United States)

    Kushner, Paul; Blackport, Russell

    2017-04-01

    In the coupled climate system, projected global warming drives extensive sea-ice loss, but sea-ice loss drives warming that amplifies and can be confounded with the global warming process. This makes it challenging to cleanly attribute the atmospheric circulation response to sea-ice loss within coupled earth-system model (ESM) simulations of greenhouse warming. In this study, many centuries of output from coupled ocean/atmosphere/land/sea-ice ESM simulations driven separately by sea-ice albedo reduction and by projected greenhouse-dominated radiative forcing are combined to cleanly isolate the hemispheric scale response of the circulation to sea-ice loss. To isolate the sea-ice loss signal, a pattern scaling approach is proposed in which the local multidecadal mean atmospheric response is assumed to be separately proportional to the total sea-ice loss and to the total low latitude ocean surface warming. The proposed approach estimates the response to Arctic sea-ice loss with low latitude ocean temperatures fixed and vice versa. The sea-ice response includes a high northern latitude easterly zonal wind response, an equatorward shift of the eddy driven jet, a weakening of the stratospheric polar vortex, an anticyclonic sea level pressure anomaly over coastal Eurasia, a cyclonic sea level pressure anomaly over the North Pacific, and increased wintertime precipitation over the west coast of North America. Many of these responses are opposed by the response to low-latitude surface warming with sea ice fixed. However, both sea-ice loss and low latitude surface warming act in concert to reduce storm track strength throughout the mid and high latitudes. The responses are similar in two related versions of the National Center for Atmospheric Research earth system models, apart from the stratospheric polar vortex response. Evidence is presented that internal variability can easily contaminate the estimates if not enough independent climate states are used to construct them

  18. Ongoing hydrothermal heat loss from the 1912 ash-flow sheet, Valley of Ten Thousand Smokes, Alaska

    Science.gov (United States)

    Hogeweg, N.; Keith, T.E.C.; Colvard, E.M.; Ingebritsen, S.E.

    2005-01-01

    The June 1912 eruption of Novarupta filled nearby glacial valleys on the Alaska Peninsula with ash-flow tuff (ignimbrite), and post-eruption observations of thousands of steaming fumaroles led to the name 'Valley of Ten Thousand Smokes' (VTTS). By the late 1980s most fumarolic activity had ceased, but the discovery of thermal springs in mid-valley in 1987 suggested continued cooling of the ash-flow sheet. Data collected at the mid-valley springs between 1987 and 2001 show a statistically significant correlation between maximum observed chloride (Cl) concentration and temperature. These data also show a statistically significant decline in the maximum Cl concentration. The observed variation in stream chemistry across the sheet strongly implies that most solutes, including Cl, originate within the area of the VTTS occupied by the 1912 deposits. Numerous measurements of Cl flux in the Ukak River just below the ash-flow sheet suggest an ongoing heat loss of ???250 MW. This represents one of the largest hydrothermal heat discharges in North America. Other hydrothermal discharges of comparable magnitude are related to heat obtained from silicic magma bodies at depth, and are quasi-steady on a multidecadal time scale. However, the VTTS hydrothermal flux is not obviously related to a magma body and is clearly declining. Available data provide reasonable boundary and initial conditions for simple transient modeling. Both an analytical, conduction-only model and a numerical model predict large rates of heat loss from the sheet 90 years after deposition.

  19. Characterization of the frictional losses and heat transfer of oscillatory viscous flow through wire-mesh regenerators

    Directory of Open Access Journals (Sweden)

    A.A. Boroujerdi

    2015-12-01

    Full Text Available In this paper, new relations for calculating heat transfer and pressure drop characteristics of oscillatory flow through wire-mesh screen regenerator such as Darcy permeability, Forchheimer’s inertial coefficient, and heat transfer area per unit volume, as a function of the wire diameter are presented. According to the derived relations, thinner wires have higher pressure drop and higher heat transfer rate. The relations are applicable for all regenerative cryocoolers. Embedding the new relations into a numerical model, three Stirling-type orifice pulse tube cryocoolers with three regenerators different in length and diameter but same volume in a variety of wire diameters, have been modeled. The results achieved by the model reveal that the local heat transfer coefficient decreases with increase of the wire diameter and the length-to-diameter ratio. In addition, it was shown that the mean absolute gas–solid wire temperature difference is a linear function of wire diameter in the range investigated. The results show that for larger length-to-diameter ratios, Forchheimer’s effect will dominate frictional losses, and the variations of the frictional losses are proportional to the inverse of the wire diameter. Wire diameter has been optimized to maximize the coefficient of performance of the cryocooler. Shorter regenerators have thinner optimum wires.

  20. ATF1 Modulates the Heat Shock Response by Regulating the Stress-Inducible Heat Shock Factor 1 Transcription Complex

    Science.gov (United States)

    Takii, Ryosuke; Fujimoto, Mitsuaki; Tan, Ke; Takaki, Eiichi; Hayashida, Naoki; Nakato, Ryuichiro; Shirahige, Katsuhiko

    2014-01-01

    The heat shock response is an evolutionally conserved adaptive response to high temperatures that controls proteostasis capacity and is regulated mainly by an ancient heat shock factor (HSF). However, the regulation of target genes by the stress-inducible HSF1 transcription complex has not yet been examined in detail in mammalian cells. In the present study, we demonstrated that HSF1 interacted with members of the ATF1/CREB family involved in metabolic homeostasis and recruited them on the HSP70 promoter in response to heat shock. The HSF1 transcription complex, including the chromatin-remodeling factor BRG1 and lysine acetyltransferases p300 and CREB-binding protein (CBP), was formed in a manner that was dependent on the phosphorylation of ATF1. ATF1-BRG1 promoted the establishment of an active chromatin state and HSP70 expression during heat shock, whereas ATF1-p300/CBP accelerated the shutdown of HSF1 DNA-binding activity during recovery from acute stress, possibly through the acetylation of HSF1. Furthermore, ATF1 markedly affected the resistance to heat shock. These results revealed the unanticipated complexity of the primitive heat shock response mechanism, which is connected to metabolic adaptation. PMID:25312646

  1. [Regulation of heat shock gene expression in response to stress].

    Science.gov (United States)

    Garbuz, D G

    2017-01-01

    Heat shock (HS) genes, or stress genes, code for a number of proteins that collectively form the most ancient and universal stress defense system. The system determines the cell capability of adaptation to various adverse factors and performs a variety of auxiliary functions in normal physiological conditions. Common stress factors, such as higher temperatures, hypoxia, heavy metals, and others, suppress transcription and translation for the majority of genes, while HS genes are upregulated. Transcription of HS genes is controlled by transcription factors of the HS factor (HSF) family. Certain HSFs are activated on exposure to higher temperatures or other adverse factors to ensure stress-induced HS gene expression, while other HSFs are specifically activated at particular developmental stages. The regulation of the main mammalian stress-inducible factor HSF1 and Drosophila melanogaster HSF includes many components, such as a variety of early warning signals indicative of abnormal cell activity (e.g., increases in intracellular ceramide, cytosolic calcium ions, or partly denatured proteins); protein kinases, which phosphorylate HSFs at various Ser residues; acetyltransferases; and regulatory proteins, such as SUMO and HSBP1. Transcription factors other than HSFs are also involved in activating HS gene transcription; the set includes D. melanogaster GAF, mammalian Sp1 and NF-Y, and other factors. Transcription of several stress genes coding for molecular chaperones of the glucose-regulated protein (GRP) family is predominantly regulated by another stress-detecting system, which is known as the unfolded protein response (UPR) system and is activated in response to massive protein misfolding in the endoplasmic reticulum and mitochondrial matrix. A translational fine tuning of HS protein expression occurs via changing the phosphorylation status of several proteins involved in translation initiation. In addition, specific signal sequences in the 5'-UTRs of some HS

  2. Experimental study of heat exchange coefficients, critical heat flux and charge losses, using water-steam mixtures in turbulent flow in a vertical tube

    International Nuclear Information System (INIS)

    Perroud, P.; De La Harpe, A.; Rebiere, J.

    1960-12-01

    Two stainless steel tubes were used (with diameters of 5 and 10 mm, lengths 400 and 600 mm respectively), heated electrically (50 Hz). The mixture flows from top to bottom. The work was carried out mainly on mixtures of high concentration (x > 0.1), at pressures between 50 and 60 kg/cm 2 , flowing as a liquid film on the walls of the tube with droplets suspended in the central current of steam. By analysis of the heat transfer laws the exchange mechanisms were established, and the conditions under which the critical heat flux may be exceeded without danger of actual burnout were determined. In this way high output concentrations (x s > 0.9) may be obtained. An attempt has been made to find out to what extent existing correlation formulae can be used to account for the phenomena observed. It is shown that those dealing with exchange coefficients can only be applied in a first approximation in cases where exchange by convection is preponderant, and only below the critical flux. The formulae proposed by WAPD and CISE do not give a satisfactory estimation of the critical heat flux, and the essential reasons for this inadequacy are explained. Lastly, the Martinelli and Nelson method may be used to an approximation of 30 per cent for the calculation of charge losses. (author) [fr

  3. Genome-wide deficiency screen for the genomic regions responsible for heat resistance in Drosophila melanogaster

    Directory of Open Access Journals (Sweden)

    Teramura Kouhei

    2011-06-01

    Full Text Available Abstract Background Temperature adaptation is one of the most important determinants of distribution and population size of organisms in nature. Recently, quantitative trait loci (QTL mapping and gene expression profiling approaches have been used for detecting candidate genes for heat resistance. However, the resolution of QTL mapping is not high enough to examine the individual effects of various genes in each QTL. Heat stress-responsive genes, characterized by gene expression profiling studies, are not necessarily responsible for heat resistance. Some of these genes may be regulated in association with the heat stress response of other genes. Results To evaluate which heat-responsive genes are potential candidates for heat resistance with higher resolution than previous QTL mapping studies, we performed genome-wide deficiency screen for QTL for heat resistance. We screened 439 isogenic deficiency strains from the DrosDel project, covering 65.6% of the Drosophila melanogaster genome in order to map QTL for thermal resistance. As a result, we found 19 QTL for heat resistance, including 3 novel QTL outside the QTL found in previous studies. Conclusion The QTL found in this study encompassed 19 heat-responsive genes found in the previous gene expression profiling studies, suggesting that they were strong candidates for heat resistance. This result provides new insights into the genetic architecture of heat resistance. It also emphasizes the advantages of genome-wide deficiency screen using isogenic deficiency libraries.

  4. Hyper-responsivity to losses in the anterior insula during economic choice scales with depression severity.

    Science.gov (United States)

    Engelmann, J B; Berns, G S; Dunlop, B W

    2017-12-01

    Commonly observed distortions in decision-making among patients with major depressive disorder (MDD) may emerge from impaired reward processing and cognitive biases toward negative events. There is substantial theoretical support for the hypothesis that MDD patients overweight potential losses compared with gains, though the neurobiological underpinnings of this bias are uncertain. Twenty-one unmedicated patients with MDD were compared with 25 healthy controls (HC) using functional magnetic resonance imaging (fMRI) together with an economic decision-making task over mixed lotteries involving probabilistic gains and losses. Region-of-interest analyses evaluated neural signatures of gain and loss coding within a core network of brain areas known to be involved in valuation (anterior insula, caudate nucleus, ventromedial prefrontal cortex). Usable fMRI data were available for 19 MDD and 23 HC subjects. Anterior insula signal showed negative coding of losses (gain > loss) in HC subjects consistent with previous findings, whereas MDD subjects demonstrated significant reversals in these associations (loss > gain). Moreover, depression severity further enhanced the positive coding of losses in anterior insula, ventromedial prefrontal cortex, and caudate nucleus. The hyper-responsivity to losses displayed by the anterior insula of MDD patients was paralleled by a reduced influence of gain, but not loss, stake size on choice latencies. Patients with MDD demonstrate a significant shift from negative to positive coding of losses in the anterior insula, revealing the importance of this structure in value-based decision-making in the context of emotional disturbances.

  5. NLP modeling for the optimization of LiBr-H2O absorption refrigeration systems with exergy loss rate, heat transfer area, and cost as single objective functions

    DEFF Research Database (Denmark)

    Mussati, Sergio F.; Gernaey, Krist; Morosuk, Tatiana

    2016-01-01

    exergy loss rate, the total heat transfer area, and the total annual cost of the system. It was found that the optimal solution obtained by minimization of the total exergy loss rate provides “theoretical” upper bounds not only for the total heat transfer area of the system but also for each process unit...... and all stream temperatures, while the optimal solution obtained by minimization of the total heat transfer area provides the lower bounds for these model variables, to solve a cost optimization problem. The minimization of the total exergy loss rate by varying parametrically the available total heat...... transfer area between these bounds was also performed, allowing to see how the optimal distribution of the available total heat transfer area among the system components, as well as the operating conditions (stream temperature, pressure, composition, and mass flow rate) and heat loads, vary qualitatively...

  6. Contrasting responses of urban and rural surface energy budgets to heat waves explain synergies between urban heat islands and heat waves

    International Nuclear Information System (INIS)

    Li, Dan; Sun, Ting; Liu, Maofeng; Yang, Long; Wang, Linlin; Gao, Zhiqiu

    2015-01-01

    Heat waves (HWs) are projected to become more frequent and last longer over most land areas in the late 21st century, which raises serious public health concerns. Urban residents face higher health risks due to synergies between HWs and urban heat islands (UHIs) (i.e., UHIs are higher under HW conditions). However, the responses of urban and rural surface energy budgets to HWs are still largely unknown. This study analyzes observations from two flux towers in Beijing, China and reveals significant differences between the responses of urban and rural (cropland) ecosystems to HWs. It is found that UHIs increase significantly during HWs, especially during the nighttime, implying synergies between HWs and UHIs. Results indicate that the urban site receives more incoming shortwave radiation and longwave radiation due to HWs as compared to the rural site, resulting in a larger radiative energy input into the urban surface energy budget. Changes in turbulent heat fluxes also diverge strongly for the urban site and the rural site: latent heat fluxes increase more significantly at the rural site due to abundant available water, while sensible heat fluxes and possibly heat storage increase more at the urban site. These comparisons suggest that the contrasting responses of urban and rural surface energy budgets to HWs are responsible for the synergies between HWs and UHIs. As a result, urban mitigation and adaption strategies such as the use of green roofs and white roofs are needed in order to mitigate the impact of these synergies. (letter)

  7. Contrasting Arctic and Antarctic atmospheric responses to future sea-ice loss

    Science.gov (United States)

    England, M.; Polvani, L. M.; Sun, L.

    2017-12-01

    By the end of this century, the annual mean Antarctic sea ice area is projected to decline by over a third, an amount similar to that in the Arctic, but the effect of Antarctic sea ice loss on the atmosphere remains largely unexplored. Using the Community Earth Systems Model (CESM) Whole Atmosphere Coupled Climate Model (WACCM), we investigate the effect of future Antarctic sea ice loss, and contrast it with its Arctic counterpart. This is accomplished by analyzing integrations of the model with historic and future sea ice levels, using the RCP8.5 scenario. This allows us to disentangle the effect of future sea ice loss on the atmosphere from other aspects of the coupled system. We find that both Antarctic and Arctic sea ice loss act to shift the tropospheric jet equatorwards, counteracting the poleward shift due to increases in greenhouse gases. Although the total forcing to the atmosphere is similar in both hemispheres, the response to Arctic sea ice loss is larger in amplitude and but more seasonally varying, while the response in the Antarctic persists throughout the year but with a smaller amplitude. Furthermore, the atmospheric temperature response over the Antarctic is trapped closer to the surface than in the Arctic, and perhaps surprisingly, we find that the surface temperature response to Antarctic sea ice loss is unable to penetrate the Antarctic continent.

  8. Heat transport as torsional responses and Keldysh formalism in a curved spacetime

    OpenAIRE

    Shitade, Atsuo

    2013-01-01

    We revisit a theory of heat transport in the light of a gauge theory of gravity and find the proper heat current with a corresponding gauge field, which yields the natural definitions of the heat magnetization and the Kubo-formula contribution to the thermal conductivity as torsional responses. We also develop a general framework for calculating gravitational responses by combining the Keldysh and Cartan formalisms. By using this framework, we explicitly calculate these two quantities and rep...

  9. Linking physiological and cellular responses to thermal stress: β-adrenergic blockade reduces the heat shock response in fish.

    Science.gov (United States)

    Templeman, Nicole M; LeBlanc, Sacha; Perry, Steve F; Currie, Suzanne

    2014-08-01

    When faced with stress, animals use physiological and cellular strategies to preserve homeostasis. We were interested in how these high-level stress responses are integrated at the level of the whole animal. Here, we investigated the capacity of the physiological stress response, and specifically the β-adrenergic response, to affect the induction of the cellular heat shock proteins, HSPs, following a thermal stress in vivo. We predicted that blocking β-adrenergic stimulation during an acute heat stress in the whole animal would result in reduced levels of HSPs in red blood cells (RBCs) of rainbow trout compared to animals where adrenergic signaling remained intact. We first determined that a 1 h heat shock at 25 °C in trout acclimated to 13 °C resulted in RBC adrenergic stimulation as determined by a significant increase in cell swelling, a hallmark of the β-adrenergic response. A whole animal injection with the β2-adrenergic antagonist, ICI-118,551, successfully reduced this heat-induced RBC swelling. The acute heat shock caused a significant induction of HSP70 in RBCs of 13 °C-acclimated trout as well as a significant increase in plasma catecholamines. When heat-shocked fish were treated with ICI-118,551, we observed a significant attenuation of the HSP70 response. We conclude that circulating catecholamines influence the cellular heat shock response in rainbow trout RBCs, demonstrating physiological/hormonal control of the cellular stress response.

  10. Saturation mechanism of the heat release response of a premixed swirl flame using LES

    NARCIS (Netherlands)

    Krediet, H.J.; Beck, C. H.; Krebs, W.; Kok, J. B.W.

    2013-01-01

    The nonlinear heat release response of a premixed swirl flame to velocity perturbations is investigated using Large Eddy Simulation. The nonlinear heat release response is required for the prediction of thermoacoustic limit cycle pressure amplitudes and is represented here by the Flame Describing

  11. Food crops face rising temperatures: An overview of responses, adaptive mechanisms, and approaches to improve heat tolerance

    Directory of Open Access Journals (Sweden)

    Neeru Kaushal

    2016-12-01

    Full Text Available The rising temperatures are resulting in heat stress for various agricultural crops to limit their growth, metabolism, and leading to significant loss of yield potential worldwide. Heat stress adversely affects normal plant growth and development depending on the sensitivity of each crop species. Each crop species has its own range of temperature maxima and minima at different developmental stages beyond which all these processes get inhibited. The reproductive stage is on the whole more sensitive to heat stress, resulting in impaired fertilization to cause abortion of flowers. During seed filling, heat stress retards seed growth by affecting all the biochemical events to reduce seed size. Unfavorable temperature may significantly affect photosynthesis, respiration, water balance, and membrane stability of leaves. To combat heat stress, plants acquire various defense mechanisms for their survival such as maintaining membrane stability, and scavenging reactive oxygen species by generating antioxidants and stress proteins. Thermo-tolerance can be improved by the accumulation of various compounds of low molecular mass known as thermo-protectants as well as phyto-hormones. Exogenous application of these molecules has benefited plants growing under heat stress. Alternatively, transgenic plants over-expressing the enzymes catalyzing the synthesis of these molecules may be raised to increase their endogenous levels to improve heat tolerance. In recent times, various transgenics have been developed with improved thermo-tolerance having potential benefits for inducing heat tolerance in food crops. Updated information about of the effects of heat stress on various food crops and their responses as well as adaptive mechanisms is reviewed here.

  12. Economic simplified boiling water reactor (ESBWR) response to an extended station blackout/ loss of all AC power

    International Nuclear Information System (INIS)

    Barrett, A.J.; Marquino, W.

    2013-01-01

    U.S. federal regulations require light water cooled nuclear power plants to cope with Station Blackout for a predetermined amount of time based on design factors for the plant. U.S. regulations define Station Blackout (SBO) as a loss of the offsite electric power system concurrent with turbine trip and unavailability of the onsite emergency AC power system. According to U.S. regulations, typically the coping period for an SBO is 4 hours and can be as long as 16 hours for currently operating BWR plants. Being able to cope with an SBO and loss of all AC power is required by international regulators as well. The U.S. licensing basis for the ESBWR is a coping period of 72 hours for an SBO based on U.S. NRC requirements for passive safety plants. In the event of an extended SBO (viz., greater than 72 hours), the ESBWR response shows that the design is able to cope with the event for at least 7 days without AC electrical power or operator action. ESBWR is a Generation III+ reactor design with an array of passive safety systems. The ESBWR primary success path for mitigation of an SBO event is the Isolation Condenser System (ICS). The ICS is a passive, closed loop, safety system that initiates automatically on a loss of power. Upon Station Blackout or loss of all AC power, the ICS begins removing decay heat from the Reactor Pressure Vessel (RPV) by (i) condensing the steam into water in heat exchangers located in pools of water above the containment, and (ii) transferring the decay heat to the atmosphere. The condensed water is then returned by gravity to cool the reactor again. The ICS alone is capable of maintaining the ESBWR in a safe shutdown condition after an SBO for an extended period. The fuel remains covered throughout the SBO event. The ICS is able to remove decay heat from the RPV for at least 7 days and maintains the reactor in a safe shutdown condition. The water level in the RPV remains well above the top of active fuel for the duration of the SBO event

  13. Investigation on heat transfer enhancement and pressure loss of double swirl chambers cooling

    Directory of Open Access Journals (Sweden)

    Gang Lin

    2013-09-01

    Full Text Available By merging two standard swirl chambers, an alternative cooling configuration named double swirl chambers (DSC has been developed. In the DSC cooling configuration, the main physical phenomena of the swirl flow in swirl chamber and the advantages of swirl flow in heat transfer augmentation are maintained. Additionally, three new physical phenomena can be found in DSC cooling configuration, which result in a further improvement of the heat transfer: (1 impingement effect has been observed, (2 internal heat exchange has been enhanced between fluids in two swirls, and (3 “∞” shape swirl has been generated because of cross effect between two chambers, which improves the mixing of the fluids. Because of all these improvements, the DSC cooling configuration leads to a higher globally-averaged thermal performance parameter (Nu¯¯/Nu∞/(f/f01/3 than standard swirl chamber. In particular, at the inlet region, the augmentation of the heat transfer is nearly 7.5 times larger than the fully developed non-swirl turbulent flow and the circumferentially averaged Nusselt number coefficient is 41% larger than the standard swirl chamber. Within the present work, a further investigation on the DSC cooling configuration has been focused on the influence of geometry parameters e.g. merging ratio of chambers and aspect ratio of inlet duct on the cooling performance. The results show a very large influence of these geometry parameters in heat transfer enhancement and pressure drop ratio. Compared with the basic configuration of DSC cooling, the improved configuration with 20% to 23% merging ratio shows the highest globally-averaged thermal performance parameter. With the same cross section area in tangential inlet ducts, the DSC cooling channel with larger aspect ratio shows larger heat transfer enhancement and at the same time reduced pressure drop ratio, which results in a better globally-averaged thermal performance parameter.

  14. Thermal Response of Tritiated Codeposits from JET and TFTR to Transient Heat Pulses

    International Nuclear Information System (INIS)

    Skinner, C.H.; Bekrisl, N.; Coad, J.P.; Gentile, C.A.; Hassanein, A.; Reiswig, R.; Willms, S.

    2002-01-01

    High heat flux interactions with plasma-facing components have been studied at microscopic scales. The beam from a continuous wave neodymium laser was scanned at high speed over the surface of graphite and carbon fiber composite tiles that had been retrieved from TFTR (Tokamak Fusion Test Reactor) and JET (Joint European Torus) after D-T plasma operations. The tiles have a surface layer of amorphous hydrogenated carbon that was co-deposited during plasma operations, and laser scanning has released more than 80% of the co-deposited tritium. The temperature rise of the co-deposit was much higher than that of the manufactured material and showed an extended time history. The peak temperature varied dramatically (e.g., 1,436 C compared to >2,300 C), indicating strong variations in the thermal conductivity to the substrate. A digital microscope imaged the co-deposit before, during, and after the interaction with the laser and revealed 100-micron scale hot spots during the interaction. Heat pulse durations of order 100 ms resulted in brittle destruction and material loss from the surface, whilst a duration of =10 ms showed minimal changes to the co-deposit. These results show that reliable predictions for the response of deposition areas to off-normal events such as ELMs (edge-localized modes) and disruptions in next-step devices need to be based on experiments with tokamak generated co-deposits

  15. Low-loss metamaterial electromagnetically induced transparency based on electric toroidal dipolar response

    Energy Technology Data Exchange (ETDEWEB)

    Li, Hai-ming; Liu, Shao-bin, E-mail: lsb@nuaa.edu.cn; Liu, Si-yuan; Ding, Guo-wen; Yang, Hua; Yu, Zhi-yang; Zhang, Hai-feng [Key Laboratory of Radar Imaging and Microwave Photonics, Nanjing University of Aeronautics and Astronautics, Nanjing, 210016 (China); Wang, Shen-yun [Research Center of Applied Electromagnetic, Nanjing University of Information Science and Technology, Nanjing, 210044 (China)

    2015-02-23

    In this paper, a low-loss and high transmission analogy of electromagnetically induced transparency based on electric toroidal dipolar response is numerically and experimentally demonstrated. It is obtained by the excitation of the low-loss electric toroidal dipolar response, which confines the magnetic field inside a dielectric substrate with toroidal geometry. The metamaterial electromagnetically induced transparency (EIT) structure is composed of the cut wire and asymmetric split-ring resonators. The transmission level is as high as 0.88, and the radiation loss is greatly suppressed, which can be proved by the surface currents distributions, the magnetic field distributions, and the imaginary parts of the effective permeability and permittivity. It offers an effective way to produce low-loss and high transmission metamaterial EIT.

  16. Heat waves imposed during early pod development in soybean (Glycine max) cause significant yield loss despite a rapid recovery from oxidative stress.

    Science.gov (United States)

    Siebers, Matthew H; Yendrek, Craig R; Drag, David; Locke, Anna M; Rios Acosta, Lorena; Leakey, Andrew D B; Ainsworth, Elizabeth A; Bernacchi, Carl J; Ort, Donald R

    2015-08-01

    Heat waves already have a large impact on crops and are predicted to become more intense and more frequent in the future. In this study, heat waves were imposed on soybean using infrared heating technology in a fully open-air field experiment. Five separate heat waves were applied to field-grown soybean (Glycine max) in central Illinois, three in 2010 and two in 2011. Thirty years of historical weather data from Illinois were analyzed to determine the length and intensity of a regionally realistic heat wave resulting in experimental heat wave treatments during which day and night canopy temperatures were elevated 6 °C above ambient for 3 days. Heat waves were applied during early or late reproductive stages to determine whether and when heat waves had an impact on carbon metabolism and seed yield. By the third day of each heat wave, net photosynthesis (A), specific leaf weight (SLW), and leaf total nonstructural carbohydrate concentration (TNC) were decreased, while leaf oxidative stress was increased. However, A, SLW, TNC, and measures of oxidative stress were no different than the control ca. 12 h after the heat waves ended, indicating rapid physiological recovery from the high-temperature stress. That end of season seed yield was reduced (~10%) only when heat waves were applied during early pod developmental stages indicates the yield loss had more to do with direct impacts of the heat waves on reproductive process than on photosynthesis. Soybean was unable to mitigate yield loss after heat waves given during late reproductive stages. This study shows that short high-temperature stress events that reduce photosynthesis and increase oxidative stress resulted in significant losses to soybean production in the Midwest, U.S. The study also suggests that to mitigate heat wave-induced yield loss, soybean needs improved reproductive and photosynthetic tolerance to high but increasingly common temperatures. Published 2015. This article is a U.S. Government work and is

  17. Reduction of heat losses on the skid pipe system of reheating furnaces in the steel industry; Verringerung der Waermeverluste am Tragrohrsystem von Waermeoefen in der Stahlindustrie

    Energy Technology Data Exchange (ETDEWEB)

    Springer, Michael; Huegel, Frank [FBB Engineering GmbH, Moenchengladbach (Germany)

    2011-06-15

    New technology can improve the energy efficiency of thermo processing equipment, innovative technology can ultimately help to reduce CO{sub 2} emissions from existing facilities and simultaneously ensure that the equipment can also operate more economically. The result of consequent development at FBB ENGINEERING GmbH for insulation of skid pipe systems of reheating furnaces in steel industry (walking beam -, pusher type furnace) are efficient pre-fabricated shells made of ultra-light weight castable FLB-11/150-I1 with thermo technical optimized sandwich design that lead to significant and sustainable reduction of heat losses and are responsible for high energy saving potential. Thermo technical CFD simulations, laboratory tests, field trials and complete installations of skid pipe systems show that compared to dense castable heat loss in the skid pipe cooling systems can be reduced up to 30 % and more with pre-fabricated shells made of ultra-light weight castable FLB-11/150-I1. (orig.)

  18. Effects of oxygen on responses to heating in two lizard species sampled along an elevational gradient.

    Science.gov (United States)

    DuBois, P Mason; Shea, Tanner K; Claunch, Natalie M; Taylor, Emily N

    2017-08-01

    Thermal tolerance is an important variable in predictive models about the effects of global climate change on species distributions, yet the physiological mechanisms responsible for reduced performance at high temperatures in air-breathing vertebrates are not clear. We conducted an experiment to examine how oxygen affects three variables exhibited by ectotherms as they heat-gaping threshold, panting threshold, and loss of righting response (the latter indicating the critical thermal maximum)-in two lizard species along an elevational (and therefore environmental oxygen partial pressure) gradient. Oxygen partial pressure did not impact these variables in either species. We also exposed lizards at each elevation to severely hypoxic gas to evaluate their responses to hypoxia. Severely low oxygen partial pressure treatments significantly reduced the gaping threshold, panting threshold, and critical thermal maximum. Further, under these extreme hypoxic conditions, these variables were strongly and positively related to partial pressure of oxygen. In an elevation where both species overlapped, the thermal tolerance of the high elevation species was less affected by hypoxia than that of the low elevation species, suggesting the high elevation species may be adapted to lower oxygen partial pressures. In the high elevation species, female lizards had higher thermal tolerance than males. Our data suggest that oxygen impacts the thermal tolerance of lizards, but only under severely hypoxic conditions, possibly as a result of hypoxia-induced anapyrexia. Copyright © 2017. Published by Elsevier Ltd.

  19. Fuzzy Adaptive Particle Swarm Optimization for Power Loss Minimisation in Distribution Systems Using Optimal Load Response

    DEFF Research Database (Denmark)

    Hu, Weihao; Chen, Zhe; Bak-Jensen, Birgitte

    2014-01-01

    Consumers may decide to modify the profile of their demand from high price periods to low price periods in order to reduce their electricity costs. This optimal load response to electricity prices for demand side management generates different load profiles and provides an opportunity to achieve...... power loss minimization in distribution systems. In this paper, a new method to achieve power loss minimization in distribution systems by using a price signal to guide the demand side management is proposed. A fuzzy adaptive particle swarm optimization (FAPSO) is used as a tool for the power loss...

  20. Effect of Stabilization Heat Treatment on Time-Dependent Polarization Losses in Sintered Nd-Fe-B Permanent Magnets

    Directory of Open Access Journals (Sweden)

    Tuominen S.

    2013-01-01

    Full Text Available Some companies in the motor and generator industry utilizing sintered NdFeB magnets have adopted pre-ageing heat treatment in order to improve the stability of the magnets. The parameters of this stabilization heat treatment are based mainly on assumptions rather than on any published research results. In this work, the effects of pre-ageing treatment on the time-dependent polarization losses of two different types of commercial sintered NdFeB magnets were studied. The material showing the squarer J(H curve did not benefit from the pre-ageing treatment, since it seems to be stable under a certain critical temperature. In contrast, a stabilizing effect was observed in the material showing rounder J(H curve. After the stabilization heat treatment, the polarization of the magnets was found to be at lower level, but unchanged over a certain period of time. The length of this period depends on the temperature and the duration of the pre-ageing treatment. In addition, our analysis reveals that the stabilization heat treatment performed in an open circuit condition does not stabilize the magnet uniformly.

  1. THERMAL POWER LOSS COMPENSATION IN THE PRODUCTION OF COOKED AND DRIED GRAINS WITH HEAT PUMPS USING

    Directory of Open Access Journals (Sweden)

    S. A. Shevtsov

    2015-01-01

    Full Text Available Using scientificand practical experience and analysis of recent innovative activity on modernization of food concentrates production, a new variant of the energy-efficient processing of cereal crops using superheated steam and direct involvement in the cooking and drying process waste energy using the vapor compression heat pump was suggested. A method for production of cereal concentrates, which is realized using microprocessor control of technological parameters. According to the information on the processes of cereals washing, cooking, drying and cooling microprocessor provides regime parameters control under the restrictions due to both yield of cooked and dried cereal of high quality and economic feasibility. At the same time the amount of moisture is continuously determined in the recirculation loop formed by the evaporation from the cereals in the drying process. To implement the proposed method of cooked and dried cereals production it is offered to use refrigerationand compressor unit operating in a heat pump mode. The refrigerant to be used is khladon 12V1 CF2ClBr with a boiling point in the evaporator of 4°C and the condensing temperature of 153.7 °C. The use of the heat pump in the heat supply system of cooked and dried cereals production instead of electric heaters will reduce power costs by 1.72 times. The proposed method for the production and control of technological parameters in the field of the product acceptable technological properties will provide high quality cooked and dried cereals; an increase in thermal efficiency by making full use of the waste heat of superheated steam; the reduction of specific energy consumption by 25-30 %; the creation of waste-free and environmentally friendly technologies for cereal production.

  2. A negative relationship between ventral striatal loss anticipation response and impulsivity in borderline personality disorder.

    Science.gov (United States)

    Herbort, Maike C; Soch, Joram; Wüstenberg, Torsten; Krauel, Kerstin; Pujara, Maia; Koenigs, Michael; Gallinat, Jürgen; Walter, Henrik; Roepke, Stefan; Schott, Björn H

    2016-01-01

    Patients with borderline personality disorder (BPD) frequently exhibit impulsive behavior, and self-reported impulsivity is typically higher in BPD patients when compared to healthy controls. Previous functional neuroimaging studies have suggested a link between impulsivity, the ventral striatal response to reward anticipation, and prediction errors. Here we investigated the striatal neural response to monetary gain and loss anticipation and their relationship with impulsivity in 21 female BPD patients and 23 age-matched female healthy controls using functional magnetic resonance imaging (fMRI). Participants performed a delayed monetary incentive task in which three categories of objects predicted a potential gain, loss, or neutral outcome. Impulsivity was assessed using the Barratt Impulsiveness Scale (BIS-11). Compared to healthy controls, BPD patients exhibited significantly reduced fMRI responses of the ventral striatum/nucleus accumbens (VS/NAcc) to both reward-predicting and loss-predicting cues. BIS-11 scores showed a significant positive correlation with the VS/NAcc reward anticipation responses in healthy controls, and this correlation, while also nominally positive, failed to reach significance in BPD patients. BPD patients, on the other hand, exhibited a significantly negative correlation between ventral striatal loss anticipation responses and BIS-11 scores, whereas this correlation was significantly positive in healthy controls. Our results suggest that patients with BPD show attenuated anticipation responses in the VS/NAcc and, furthermore, that higher impulsivity in BPD patients might be related to impaired prediction of aversive outcomes.

  3. Radiation loss and global energy balance of ohmically heated divertor discharge in JT-60 tokamak

    International Nuclear Information System (INIS)

    Koide, Yoshihiko; Yamada, Kimio; Yoshida, Hidetoshi; Nakamura, Hiroo; Niikura, Setsuo; Tsuji, Shunji

    1986-03-01

    Divertor experiment in JT-60 with a small divertor chamber has been successfully performed up to 1.6 MA discharge. Several divertor effects were experimentally confirmed as follows. Radiation loss in main plasma saturates with the increase of plasma current and its ratio to the input power is about 20 % at 1.5 MA. The rest of input power is exhausted into the divertor chamber and a half of it is dissipated as the radiation loss. Impurity accumulation is not observed during a few sec without internal MHD activity and gross impurity confinement time is several hundred msec. (author)

  4. Evaluation of a loss of residual heat removal event during mid-loop operation

    International Nuclear Information System (INIS)

    Seul, Kwang Won; Bang, Young Seok; Lee, Sukho; Kim, Hho Jung

    1996-01-01

    The potential for the RELAP5/MOD3.2 was assessed for the loss-of -RHR event during the mid-loop operation and the predictability of major thermal-hydraulic phenomena was also evaluated for the long term transient. The analysis results of the typical two cases(cold leg opening case and pressurizer opening case) were compared with experimental data which was conducted at ROSA-IV/LSTF in Japan. As a result, it was shown that the code was capable of simulating the thermal-hydraulic transport process with appropriate time step during the reduced inventory operation with the loss-of-RHR system

  5. Comparison of the superelasticity of different nickel?titanium orthodontic archwires and the loss of their properties by heat treatment

    OpenAIRE

    Bellini, Humberto; Moyano, Javier; Gil, Javier; Puigdollers, Andreu

    2016-01-01

    The aim of this work is to describe and compare mechanical properties of eight widely used nickel?titanium orthodontic wires under uniform testing conditions and to determine the influence of the heat treatments on the loss of the superelasticity. Ten archwires from two batches from eight different manufacturers were evaluated. A three-point bending test was performed, in accordance with ISO 15841:2006, on 80 round nickel?titanium archwire segments of 0.016?inch. To obtain a load-deflection c...

  6. Physiological stress response to loss of social influence and threats to masculinity.

    Science.gov (United States)

    Taylor, Catherine J

    2014-02-01

    Social influence is an important component of contemporary conceptualizations of masculinity in the U.S. Men who fail to achieve masculinity by maintaining social influence in the presence of other men may be at risk of stigmatization. As such, men should be especially likely to exhibit a stress response to loss of social influence in the presence of other men. This study assesses whether men who lose social influence exhibit more of a stress response than men who gain social influence, using data collected in a laboratory setting where participants were randomly assigned into four-person groups of varying sex compositions. The groups were videotaped working on two problem-solving tasks. Independent raters assessed change in social influence using a well-validated measure borrowed from experimental work in the Status Characteristics Theory tradition. Cortisol is used as a measure of stress response because it is known to increase in response to loss of social esteem. Results show that young men who lose social influence while working with other young men exhibit cortisol response. In contrast women do not exhibit cortisol response to loss of social influence, nor do men working with women. Results are consistent with the hypothesis that loss of social influence in men may be associated with a physiological stress response because maintaining social influence is very important to men while in the presence of other men. This physiological response to loss of social influence underscores the importance to men of achieving masculinity through gaining and maintaining social influence, and avoiding the stigma associated with the failure to do so. Copyright © 2013 Elsevier Ltd. All rights reserved.

  7. ITER SAFETY TASK NID-5D: Operational tritium loss and accident investigation for heat transport and water detritiation systems

    International Nuclear Information System (INIS)

    Kalyanam, K.M.; Fong, C.; Moledina, M.; Natalizio, A.

    1995-02-01

    The task objectives are to: a) determine major pathways for tritium loss during normal operation of the cooling systems and water detritiation system, b) estimate operational losses and environmental tritium releases from the heat transport and water detritiation systems of ITER, and c) prepare a preliminary Failure Modes and Effects Analysis (FMEA) for the ITER Water Detritiation System. The analysis will be used to estimate chronic environmental tritium releases (airborne and waterborne) for the ITER Cooling Systems and Water Detritiation System. The assessment will form the basis for demonstrating the acceptability of ITER for siting in the Early Safety and Environmental Characterization Study (ESECS), to be issued in early 1995. (author). 7 refs., 10 tabs., 11 figs

  8. Novel Method for Measuring the Heat Collection Rate and Heat Loss Coefficient of Water-in-Glass Evacuated Tube Solar Water Heaters Based on Artificial Neural Networks and Support Vector Machine

    Directory of Open Access Journals (Sweden)

    Zhijian Liu

    2015-08-01

    Full Text Available The determinations of heat collection rate and heat loss coefficient are crucial for the evaluation of in service water-in-glass evacuated tube solar water heaters. However, the direct determination requires complex detection devices and a series of standard experiments, which also wastes too much time and manpower. To address this problem, we propose machine learning models including artificial neural networks (ANNs and support vector machines (SVM to predict the heat collection rate and heat loss coefficient without a direct determination. Parameters that can be easily obtained by “portable test instruments” were set as independent variables, including tube length, number of tubes, tube center distance, heat water mass in tank, collector area, final temperature and angle between tubes and ground, while the heat collection rate and heat loss coefficient determined by the detection device were set as dependent variables respectively. Nine hundred fifteen samples from in-service water-in-glass evacuated tube solar water heaters were used for training and testing the models. Results show that the multilayer feed-forward neural network (MLFN with 3 nodes is the best model for the prediction of heat collection rate and the general regression neural network (GRNN is the best model for the prediction of heat loss coefficient due to their low root mean square (RMS errors, short training times, and high prediction accuracies (under the tolerances of 30%, 20%, and 10%, respectively.

  9. A Mass Loss Penetration Model to Investigate the Dynamic Response of a Projectile Penetrating Concrete considering Mass Abrasion

    Directory of Open Access Journals (Sweden)

    NianSong Zhang

    2015-01-01

    Full Text Available A study on the dynamic response of a projectile penetrating concrete is conducted. The evolutional process of projectile mass loss and the effect of mass loss on penetration resistance are investigated using theoretical methods. A projectile penetration model considering projectile mass loss is established in three stages, namely, cratering phase, mass loss penetration phase, and remainder rigid projectile penetration phase.

  10. The dose-response relationship between in-ear occupational noise exposure and hearing loss.

    Science.gov (United States)

    Rabinowitz, Peter M; Galusha, Deron; Dixon-Ernst, Christine; Clougherty, Jane E; Neitzel, Richard L

    2013-10-01

    Current understanding of the dose-response relationship between occupational noise and hearing loss is based on cross-sectional studies prior to the widespread use of hearing protection, and with limited data regarding noise exposures below 85 dBA. We report on the hearing loss experience of a unique cohort of industrial workers, with daily monitoring of noise inside of hearing protection devices. At an industrial facility, workers exhibiting accelerated hearing loss were enrolled in a mandatory programme to monitor daily noise exposures inside of hearing protection. We compared these noise measurements (as time-weighted LAVG) to interval rates of high-frequency hearing loss over a 6-year period using a mixed-effects model, adjusting for potential confounders. Workers' high-frequency hearing levels at study inception averaged more than 40 dB Hearing threshold level (HTL). Most noise exposures were less than 85 dBA (mean LAVG 76 dBA, IQR 74-80 dBA). We found no statistical relationship between LAvg and high-frequency hearing loss (p=0.53). Using a metric for monthly maximum noise exposure did not improve model fit. At-ear noise exposures below 85 dBA did not show an association with risk of high-frequency hearing loss among workers with substantial past noise exposure and hearing loss at baseline. Therefore, effective noise control to below 85 dBA may lead to significant reduction in occupational hearing loss risk in such individuals. Further research is needed on the dose-response relationship of noise and hearing loss in individuals with normal hearing and little prior noise exposure.

  11. The Dose Response Relationship between In Ear Occupational Noise Exposure and Hearing Loss

    Science.gov (United States)

    Rabinowitz, Peter M.; Galusha, Deron; Dixon-Ernst, Christine; Clougherty, Jane E.; Neitzel, Richard L.

    2014-01-01

    Objectives Current understanding of the dose-response relationship between occupational noise and hearing loss is based on cross-sectional studies prior to the widespread use hearing protection and with limited data regarding noise exposures below 85dBA. We report on the hearing loss experience of a unique cohort of industrial workers with daily monitoring of noise inside of hearing protection devices. Methods At an industrial facility, workers exhibiting accelerated hearing loss were enrolled in a mandatory program to monitor daily noise exposures inside of hearing protection. We compared these noise measurements (as time-weighted LAVG) to interval rates of high frequency hearing loss over a six year period using a mixed effects model, adjusting for potential confounders. Results Workers’ high frequency hearing levels at study inception averaged more than 40 dB hearing threshold level (HTL). Most noise exposures were less than 85dBA (mean LAVG 76 dBA, interquartile range 74 to 80 dBA). We found no statistical relationship between LAvg and high frequency hearing loss (p = 0.53). Using a metric for monthly maximum noise exposure did not improve model fit. Conclusion At-ear noise exposures below 85dBA did not show an association with risk of high frequency hearing loss among workers with substantial past noise exposure and hearing loss at baseline. Therefore, effective noise control to below 85dBA may lead to significant reduction in occupational hearing loss risk in such individuals. Further research is needed on the dose response relationship of noise and hearing loss in individuals with normal hearing and little prior noise exposure. PMID:23825197

  12. EFFECTIVENESS OF USING POLYURETHANE FOAM TO REDUCE HEAT LOSS IN THE PREMISES FOR BREEDING

    Directory of Open Access Journals (Sweden)

    Medvedev A.Y.

    2013-10-01

    Full Text Available It is proved that the use of polyurethane foam insulation for the purpose of walling premises for breeding allows them to halve the deficit of heat in winter. Because of this more efficient use of feed, increases the intensity and the level of growth of young comprehensive energp $rocess in the energy of live weight gain of cattle while increasing the profitability of its cultivation for meat.

  13. Experimental investigation of airfoil trailing edge heat transfer and aerodynamic losses

    Energy Technology Data Exchange (ETDEWEB)

    Brundage, A.L. [Sandia National Laboratories, Albuquerque, NM 87185 (United States); Plesniak, M.W.; Lawless, P.B. [School of Mechanical Engineering, Maurice J. Zucrow Laboratories, Purdue University, West Lafayette, IN 47907 (United States); Ramadhyani, S. [132 Cecil Street SE, Minneapolis, MN 55414 (United States)

    2007-01-15

    Modern gas turbine development is being driven by the often-incompatible goals of increased efficiency, better durability, and reduced emissions. High turbine inlet temperatures and ineffective cooling at the trailing edge of a first-stage stator vane lead to corrosion, oxidation, and thermal fatigue. Observations of this region in engines frequently reveal burn marks, cracks, and buckling. Fundamental studies of the importance of trailing edge heat transfer to the design of an optimal cooling scheme are scarce. An experimental study of an actively cooled trailing edge configuration, in which coolant is injected through a slot, is performed. Trailing edge heat transfer and aerodynamic measurements are reported. An optimum balance between maximizing blade row aerodynamic efficiency and improving thermal protection at the trailing edge is estimated to be achieved when blowing ratios are in the range between 2.1% and 2.8%. The thermal phenomena at the trailing edge are dominated by injection slot heat transfer and flow physics. These measured trends are generally applicable over a wide range of gas turbine applications. (author)

  14. Evaluation of the Safety Issue Concerning the Potential for Loss of Decay Heat Removal Function due to Crude Oil Spill in the Ultimate Heat Sink of Nuclear Reactors

    International Nuclear Information System (INIS)

    Jo, Jong Chull; Roh, Kyung Wan; Yune, Young Gill; Kang, Dong Gu; Kim, Hho Jhung

    2008-01-01

    A barge crashed into a moored oil tanker at about 7:15 a.m., Dec. 12, 2007, dumping around 10,500 tons of crude oil into the sea in Korea. The incident took place about 15 kilometers northwest of Manripo beach in South Chungcheong where is Korea's west coast in the Yellow Sea. In a few days, the oil slicks spread to the northern and southern tips of the Taean Peninsula by strong winds and tides. As time went the spilled oil floating on the surface of sea water was volatilized to become tar-balls and lumps and drifted far away in the southern direction. 13 days after the incident, some of oil slicks and tar lumps were observed to flow in the service water intake at the Younggwang nuclear power plants (NPPs) operating 6 reactors, which are over 150 km away from the incident spot in the southeastern direction. According to the report by the Younggwang NPPs, a total weight 83 kg of tar lumps was removed for about 3 days. Oil spills in the sea can happen in any country or anytime due to human errors or mistakes, wars, terrors, intentional dumping of waste oils, and natural disasters like typhoon and tsunami. In fact, there have been 7 major oil spills over 10,000 tons that have occurred around the world since 1983. As such serious oil spill incidents may happen near the operating power plants using the sea water as ultimate heat sink. To ensure the safe operation of nuclear reactors it is required to evaluate the potential for loss of decay heat removal function of nuclear reactors due to the spilled oils flowing in the service water intake, from which the service water is pumped. Thus, Korea Institute of Nuclear Safety identified this problem as one of the important safety. When an incident of crude oil spill from an oil carrier occurs in the sea near the nuclear power plants, the spilled oil can be transported to the intake pit, where all service water pumps locate, by sea current and wind drift (induced) current. The essential service water pumps take the service

  15. Evaluation of the Safety Issue Concerning the Potential for Loss of Decay Heat Removal Function due to Crude Oil Spill in the Ultimate Heat Sink of Nuclear Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Jo, Jong Chull; Roh, Kyung Wan; Yune, Young Gill; Kang, Dong Gu; Kim, Hho Jhung [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

    2008-05-15

    A barge crashed into a moored oil tanker at about 7:15 a.m., Dec. 12, 2007, dumping around 10,500 tons of crude oil into the sea in Korea. The incident took place about 15 kilometers northwest of Manripo beach in South Chungcheong where is Korea's west coast in the Yellow Sea. In a few days, the oil slicks spread to the northern and southern tips of the Taean Peninsula by strong winds and tides. As time went the spilled oil floating on the surface of sea water was volatilized to become tar-balls and lumps and drifted far away in the southern direction. 13 days after the incident, some of oil slicks and tar lumps were observed to flow in the service water intake at the Younggwang nuclear power plants (NPPs) operating 6 reactors, which are over 150 km away from the incident spot in the southeastern direction. According to the report by the Younggwang NPPs, a total weight 83 kg of tar lumps was removed for about 3 days. Oil spills in the sea can happen in any country or anytime due to human errors or mistakes, wars, terrors, intentional dumping of waste oils, and natural disasters like typhoon and tsunami. In fact, there have been 7 major oil spills over 10,000 tons that have occurred around the world since 1983. As such serious oil spill incidents may happen near the operating power plants using the sea water as ultimate heat sink. To ensure the safe operation of nuclear reactors it is required to evaluate the potential for loss of decay heat removal function of nuclear reactors due to the spilled oils flowing in the service water intake, from which the service water is pumped. Thus, Korea Institute of Nuclear Safety identified this problem as one of the important safety. When an incident of crude oil spill from an oil carrier occurs in the sea near the nuclear power plants, the spilled oil can be transported to the intake pit, where all service water pumps locate, by sea current and wind drift (induced) current. The essential service water pumps take the

  16. Analysis of loss of decay heat removal sequences at Browns Ferry Unit One: Chapter 17

    International Nuclear Information System (INIS)

    Harrington, R.M.

    1983-01-01

    This paper summarizes the Oak Ridge National Laboratory (ORNL) report ''Loss of DHR Sequences at Browns Ferry Unit One - Accident Sequence Analysis'' (NUREG/CR-2973). The Loss of DHR investigation is the third in a series of accident studies concerning the BWR 4 - MK I containment plant design. These studies, sponsored by the Nuclear Regulatory Commission Severe Accident Sequence Analysis (SASA) program, have been conducted at ORNL with the full cooperation of the Tennessee Valley Authority (TVA), using Unit One of the Browns Ferry Nuclear Plant as the model design. Each unit of this three-unit plant has a maximum authorized power of 3293 MW(t) or 1067 net MW(e). The primary containments are of the Mark I pressure suppression pool type and the three units share a secondary containment of the controlled leakage, elevated release design. Each unit occupies a separate reactor building located in one structure underneath the common refueling floor

  17. The effects of heating on mechanical loss in tantala/silica optical coatings

    International Nuclear Information System (INIS)

    Abernathy, Matthew R.; Harry, Gregory M.; Travasso, Flavio; Martin, Iain; Reid, Stuart; Rowan, Sheila; Hough, Jim; Fejer, Martin M.; Route, Roger; Penn, Steve; Armandula, Helena; Gretarsson, Andri

    2008-01-01

    Second-generation interferometric gravitational-wave detectors will operate at temperatures noticeably above room temperature. Study was done to determine what effect elevated temperatures would have on the Q and coating thermal noise of the detector mirrors. Results show that increased temperature increases loss angle in a manner that is more significant at higher frequencies. Trends show that the increased temperature will have a negligible effect at the low (100 Hz) frequencies important to second-generation detectors

  18. The Scaling of Loss Pathways and Heat Transfer in Small Scale Internal Combustion Engines

    Science.gov (United States)

    2016-09-16

    to the time required for mass transport in the system and describes how fast combustion will propagate relative to the rate that mass is transported ...it had much lower parasitic losses [117]. 3.6.2. Fuel AKI Reduction and Alternative Fuels As the largest single consumer of transport fuel in the...United States, the Air Force also has a vested interest in alternative fuels. Groenewegen et al. [120] investigated algae and Camelia biodiesels as

  19. Thermal response testing of precast pile heat exchangers

    DEFF Research Database (Denmark)

    Pagola, Maria Alberdi; Poulsen, Søren Erbs; Jensen, Rasmus Lund

    The report is organized as follows: first, the concept of TRT is explained. Second, the test sites are described. Third, the field work is presented and a summary of the future work regarding the methodology to treat the data from the tests is provided. Finally, further documentation...... of the fieldwork, the pile heat exchangers and the TRT equipment is extended in diverse appendices....

  20. Heat shock response and autophagy--cooperation and control

    DEFF Research Database (Denmark)

    Dokladny, Karol; Myers, Orrin B; Moseley, Pope L

    2015-01-01

    Protein quality control (proteostasis) depends on constant protein degradation and resynthesis, and is essential for proper homeostasis in systems from single cells to whole organisms. Cells possess several mechanisms and processes to maintain proteostasis. At one end of the spectrum, the heat...

  1. Treatment response to the RENEW weight loss intervention in schizophrenia: impact of intervention setting.

    Science.gov (United States)

    Brown, Catana; Goetz, Jeannine; Hamera, Edna; Gajewski, Byron

    2014-11-01

    Individuals with serious mental illness have high rates of obesity and a need for specialized weight loss intervention programs. This study examines the efficacy of the RENEW weight loss intervention and examines the impact of the intervention setting on outcomes. 136 individuals with serious mental illness from 4 different settings were randomly assigned to receive the RENEW weight loss intervention or a control condition of treatment as usual. The RENEW intervention is a one year program that includes an intensive, maintenance and intermittent supports phase. The intervention group experienced a modest weight loss of 4.8 lbs at 3 months, 4.1 lbs at 6 months and a slight weight gain of 1.5 lbs at 12 months. The control group gained a total of 6.2 lbs at 12 months. However when settings were examined separately the responder sites had a weight loss of 9.4 lbs at 3 months, 10.9 lbs at 6 months and 7 lbs at 12 months. These results suggest that the settings in which individuals receive services may act as a support or hindrance toward response to weight loss interventions. The concept of the obesogenic environment deserves further examination as a factor in the success of weight loss programs. Copyright © 2014 Elsevier B.V. All rights reserved.

  2. Heat adaptation from regular hot water immersion decreases proinflammatory responses, HSP70 expression, and physical heat stress.

    Science.gov (United States)

    Yang, Fwu-Lin; Lee, Chia-Chi; Subeq, Yi-Maun; Lee, Chung-Jen; Ke, Chun-Yen; Lee, Ru-Ping

    2017-10-01

    Hot-water immersion (HWI) is a type of thermal therapy for treating various diseases. In our study, the physiological responses to occasional and regular HWI have been explored. The rats were divided into a control group, occasional group (1D), and regular group (7D). The 1D and 7D groups received 42°C during 15mins HWI for 1 and 7 days, respectively. The blood samples were collected for proinflammatory cytokines examinations, the heart, liver and kidney were excised for subsequent IHC analysis to measure the level of heat shock protein 70 (HSP70). The results revealed that the body temperature increased significantly during HWI on Day 3 and significantly declined on Days 6 and 7. For the 7D group, body weight, heart rate, hematocrit, platelet, osmolarity, and lactate level were lower than those in the 1D group. Furthermore, the levels of granulocyte counts, tumor necrosis factor-α, and interleukin-6 were lower in the 7D group than in the 1D group. The induction of HSP70 in the 1D group was higher than in the other groups. Physiological responses to occasional HWI are disadvantageous because of heat stress. However, adaptation to heat from regular HWI resulted in decreased proinflammatory responses and physical heat stress. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. A negative relationship between ventral striatal loss anticipation response and impulsivity in borderline personality disorder

    OpenAIRE

    Herbort, Maike C.; Soch, Joram; W?stenberg, Torsten; Krauel, Kerstin; Pujara, Maia; Koenigs, Michael; Gallinat, J?rgen; Walter, Henrik; Roepke, Stefan; Schott, Bj?rn H.

    2016-01-01

    Patients with borderline personality disorder (BPD) frequently exhibit impulsive behavior, and self-reported impulsivity is typically higher in BPD patients when compared to healthy controls. Previous functional neuroimaging studies have suggested a link between impulsivity, the ventral striatal response to reward anticipation, and prediction errors. Here we investigated the striatal neural response to monetary gain and loss anticipation and their relationship with impulsivity in 21 female BP...

  4. Flux loss and heating during the formation of a field-reversed configuration

    International Nuclear Information System (INIS)

    Sgro, A.G.; Armstrong, W.T.; Lipson, J.; Tuszewski, M.G.; Cochrane, J.C.

    1982-01-01

    The simulated time evolution of magnetic field profiles and trapped flux in a field-reversed configuration, when compared with the experiment, implies that the rapid decay of the initial reversed flux is due to a resistivity that is anomalously enhanced over its classical value. A tenuous plasma between the field-reversed configuration and the wall carries a significant fraction of the current, and about half of the anomalous Joule heating must be deposited directly in the ions in order to calculate the correct ion temperature. The fractional flux retention is most sensitive to an increase of applied bias field

  5. Response of Cryolite-Based Bath to a Shift in Heat Input/output Balance

    Science.gov (United States)

    Liu, Jingjing; Taylor, Mark; Dorreen, Mark

    2017-04-01

    A technology for low amperage potline operation is now recognized as a competitive advantage for the aluminum smelting industry in order to align smelter operations with the power and aluminum price markets. This study investigates the cryolite-based bath response to heat balance shifts when the heat extraction from the bath is adjusted to different levels in a laboratory analogue. In the analogue experiments, the heat balance shift is driven by a graphite `cold finger' heat exchanger, which can control the heat extraction from the analogue, and a corresponding change in heat input from the furnace which maintains the control temperature of the lab "cell." This paper reports the first experimental results from shifting the steady state of the lab cell heat balance, and investigates the effects on the frozen ledge and bath superheat. The lab cell energy balances are compared with energy balances in a published industrial cell model.

  6. Physiological and proteome studies of responses to heat stress during grain filling in contrasting wheat cultivars

    DEFF Research Database (Denmark)

    Wang, Xiao; Dinler, Burcu Seckin; Vignjevic, Marija

    2015-01-01

    compared to sensitive cultivars under heat stress. The tolerant cv. '810' and the sensitive cv. '1039' were selected for further proteome analysis of leaves. Proteins related to photosynthesis, glycolysis, stress defence, heat shock and ATP production were differently expressed in leaves of the tolerant...... and sensitive cultivar under heat stress in relation to the corresponding control. The abundance of proteins related to signal transduction, heat shock, photosynthesis, and antioxidants increased, while the abundance of proteins related to nitrogen metabolism decreased in the tolerant cv. '810' under heat......Experiments to explore physiological and biochemical differences of the effects of heat stress in ten wheat (Triticum aestivum L) cultivars have been performed. Based on the response of photosynthesis rates, cell membrane lipid peroxide concentrations and grain yield to heat, six cultivars were...

  7. Physiological responses and physical performance during football in the heat

    DEFF Research Database (Denmark)

    Mohr, Magni; Nybo, Lars; Grantham, Justin

    2012-01-01

    To examine the impact of hot ambient conditions on physical performance and physiological responses during football match-play.......To examine the impact of hot ambient conditions on physical performance and physiological responses during football match-play....

  8. Nonlocal response in thin-film waveguides: Loss versus nonlocality and breaking of complementarity

    DEFF Research Database (Denmark)

    Raza, Søren; Christensen, Thomas; Wubs, Martijn

    2013-01-01

    the Thomas-Fermi internal kinetic energy of the free electrons in the metal. We derive the nonlocal dispersion relations of the three waveguide structures taking into account also retardation and interband effects, and examine the delicate interplay between nonlocal response and absorption losses...

  9. Species loss, delayed numerical responses, and functional compensation in an antbird guild.

    Science.gov (United States)

    Touchton, Janeene M; Smith, James N M

    2011-05-01

    When a community loses species through fragmentation, its total food consumption may drop. Compensatory responses of remaining species, whereby survivors assume roles of extinct competitors, may reduce the impact of species loss through numerical or functional responses. We measured compensatory responses in two remaining antbird species on Barro Colorado Island, Panama, four decades after the loss of their dominant competitor, the Ocellated Antbird, Phaenostictus mcleannani. We compared current abundances and behavior of these two species on Barro Colorado to those reported before the island lost Ocellated Antbirds, and to those in a nearby mainland population where all three species still exist as a space-for-time substitution. The smaller, more subordinate Spotted Antbird, Hylophylax naevioides, responded far more strongly than the larger Bicolored Antbird, Gymnopithys leucaspis, which is functionally more like the Ocellated Antbird. Islandwide density of Spotted Antbirds has more than doubled since the loss of Ocellated Antbirds. Moreover, Spotted Antbirds now spend so much more of their time following ant swarms that their metabolic biomass at these swarms has more than tripled since Ocellated Antbirds disappeared. These responses in Spotted Antbirds were apparently delayed by >20 years. Bicolored Antbirds have not increased substantially in islandwide density or metabolic biomass at ant swarms. We hypothesize that behavioral flexibility, as shown by Spotted Antbirds on Barro Colorado Island, is a major factor governing the extent to which fragmented ecosystems can buffer the impacts of species loss.

  10. The Performance of a Second Generation Service Discovery Protocol In Response to Message Loss

    NARCIS (Netherlands)

    Sundramoorthy, V.; van de Glind, G.J.; Hartel, Pieter H.; Scholten, Johan

    We analyze the behavior of FRODO, a second generation service discovery protocol, in response to message loss in the network. Earlier protocols, like UPnP and Jini rely on underlying network layers to enhance their failure recovery. A comparison with UPnP and Jini shows that FRODO performs more

  11. The Performance of a Second Generation Service Discovery Protocol In Response to Message Loss

    NARCIS (Netherlands)

    Sundramoorthy, V.; van de Glind, G.J.; Hartel, Pieter H.; Scholten, Johan

    We analyze the behavior of FRODO, a second generation service discovery protocol, in response to message loss in the network. First generation protocols, like UPnP and Jini rely on underlying network layers to enhance their failure recovery. A comparison with UPnP and Jini shows that FRODO performs

  12. Measurement of AC losses in superconducting tapes by reproduction of thermometric dynamic response

    Energy Technology Data Exchange (ETDEWEB)

    Ligneris, Benoit des; Aubin, Marcel; Cave, Julian

    2003-04-15

    We have developed a dynamic response thermometric method for the measurement of AC losses in high T{sub c} superconductors. This method is based on the comparison of a temperature response caused by a known dissipation in the sample with that produced by the AC losses. By passing a DC current and measuring the DC voltage and corresponding temperature response the sample can be used as its own power dissipation reference. The advantages of this method are the short measurement duration time and the possibility to vary many experimental conditions: for example, AC and DC transport currents and AC, DC and rotating applied magnetic fields. In this article we present the basic method using variable short pulses of constant DC current for calibration and similarly of constant amplitude AC current to create the losses. The losses are obtained by numerical modelling and comparison of the thermometric dynamic response in the two above conditions. Finally, we present some experimental results for a Bi2223 superconducting tape at 50 Hz and 77 K.

  13. Respite Utilization and Responses to Loss among Family Caregivers: Relationship Matters

    Science.gov (United States)

    DeCaporale, Lauren; Mensie, Lauren; Steffen, Ann

    2013-01-01

    Family caregivers of physically and cognitively impaired older adults face multiple challenges when providing care, including responses to tangible and anticipated losses. However, little is known about the grief experiences of family caregivers and how these might differentially influence the care-related behaviors of spouses and adult children.…

  14. Winter reduction in body mass in a very small, nonhibernating mammal: consequences for heat loss and metabolic rates.

    Science.gov (United States)

    Taylor, Jan R E; Rychlik, Leszek; Churchfield, Sara

    2013-01-01

    Low temperatures in northern winters are energetically challenging for mammals, and a special energetic burden is expected for diminutive species like shrews, which are among the smallest of mammals. Surprisingly, shrews shrink their body size in winter and reduce body and brain mass, an effect known as Dehnel's phenomenon, which is suggested to lower absolute energy intake requirements and thereby enhance survival when food availability is low. Yet reduced body size coupled with higher body-surface-to-mass ratio in these tiny mammals may result in thermoregulatory heat production at a given temperature constituting a larger proportion of the total energy expenditure. To evaluate energetic consequences of reduced body size in winter, we investigated common shrews Sorex araneus in northeastern Poland. Average body mass decreased by 19.0% from summer to winter, and mean skull depth decreased by 13.1%. There was no difference in Dehnel's phenomenon between years despite different weather conditions. The whole-animal thermal conductance (proportional to absolute heat loss) in shrews was 19% lower in winter than in summer; the difference between the two seasons remained significant after correcting for body mass and was caused by improved fur insulation in winter. Thermogenic capacity of shrews, although much enhanced in winter, did not reach its full potential of increase, and this corresponded with relatively mild subnivean temperatures. These findings indicate that, despite their small body size, shrews effectively decrease their costs of thermoregulation. The recorded decrease in body mass from summer to winter resulted in a reduction of overall resting metabolic rate (in thermoneutrality) by 18%. This, combined with the reduced heat loss, should translate to food requirements that are substantially lower than would be the case if shrews did not undergo seasonal decrease in body mass.

  15. The Weight Loss Effect of Heated Inner Cylinder by Free Convection in Horizontal Cylindrical Enclosure

    Science.gov (United States)

    Sboev, I. O.; Kondrashov, A. N.; Rybkin, K. A.; Burkova, L. N.; Goncharov, M. M.

    2018-03-01

    The work presents results of numerical simulations of natural convection in cavity formed by the surfaces of two horizontal coaxial cylinders. The temperature of the outer cylinder is constant. The area between the cylinders is filled with an ideal incompressible fluid. The inner cylinder is set as the heater. The solution of the equations of thermal convection in a two-dimensional approximation performed by the software package ANSYS Fluent with finite volume method. The study compares the results of numerical simulation with several well-known theoretical and experimental results. The nature of interaction of the inner cylinder with a convection current created in the gap was observed. It was shown that the flux appeared around a heated cylinder affects the weight of the heat source and causes an additional lift force from the surrounding fluid. The various Rayleigh numbers (from 1.0 ṡ 103 to 1.5 ṡ 106) and fluid with different Prandtl number (from 0.5 to 1.0 ṡ 105) are considered.

  16. Neural responses to gains and losses in children of suicide attempters.

    Science.gov (United States)

    Tsypes, Aliona; Owens, Max; Hajcak, Greg; Gibb, Brandon E

    2017-02-01

    [Correction Notice: An Erratum for this article was reported in Vol 126(2) of Journal of Abnormal Psychology (see record 2016-56318-001). In the article, Figure 1 had incorrect axis labels. There was also an error in the abstract, which did not state that ΔFN was calculated as FN to losses minus FN to gains. All versions of this article have been corrected.] Suicidal behavior aggregates within families, yet the specific mechanisms of suicide-risk transmission are poorly understood. Despite some evidence that abnormal patterns of reward responsiveness might constitute one such potential mechanism, empirical evidence is lacking. The goal of this study was to examine neural responses to gains and losses in children of suicide attempters with no personal history of suicide attempt (SA) themselves. To objectively assess these neural responses, we used feedback negativity (FN), a psychophysiological marker of responsiveness to reward and loss. Participants were 66 parents and their 7-11-year-old children (22 with parental history of SA and 44 demographically and clinically matched children of parents with no SA history). Diagnostic interviews were used to gather information about psychiatric diagnoses, symptoms, and histories of suicidal thoughts and behaviors. Children also completed a guessing task, during which continuous electroencephalography (EEG) was recorded. The FN was scored as the mean amplitude, 275-375 ms, following gain or loss feedback at frontocentral sites (Fz and FCz). Children of suicide attempters exhibited significantly more negative ΔFN (i.e., FN to losses minus FN to gains) than children of parents with no SA history. We found that this difference in ΔFN was due specifically to children of parents with a history of SA exhibiting a stronger response to loss, and no group differences were observed for responses to gains. The results suggest that an increased neural response to loss might represent one of the potential pathways of the familial

  17. Identification of proteins involved in the heat stress response of Bacillus cereus ATCC 14579

    NARCIS (Netherlands)

    Periago, P.M.; Schaik, van W.; Abee, T.; Wouters, J.A.

    2002-01-01

    To monitor the ability of the food-borne opportunistic pathogen Bacillus cereus to survive during minimal processing of food products, we determined its heat-adaptive response. During pre-exposure to 42°C, B. cereus ATCC 14579 adapts to heat exposure at the lethal temperature of 50°C (maximum

  18. Differential Response to Heat Stress in Outer and Inner Onion Bulb Scales.

    Science.gov (United States)

    Galsurker, Ortal; Doron-Faigenboim, Adi; Teper-Bamnolker, Paula; Daus, Avinoam; Lers, Amnon; Eshel, Dani

    2018-05-18

    Brown protective skin formation in onion bulbs can be induced by rapid postharvest heat treatment. Onions that were peeled to different depths and were exposed to heat stress showed that only the outer scale formed dry brown skin, whereas the inner scales maintained high water content and did not change color. Our results reveal that browning of the outer scale during heat treatment is due to an enzymatic process that is associated with high levels of oxidation components, such as peroxidase and quercetin glucoside. De-novo transcriptome analysis revealed differential molecular responses of the outer and inner scales to the heat stress. Genes involved in lipid metabolism, oxidation pathways and cell-wall modification were highly expressed in the outer scale during heating. Defense-response-related genes such as those encoding heat-shock proteins, antioxidative stress defense or production of osmoprotectant metabolites were mostly induced in the inner scale in response to the heat exposure. These transcriptomic data led to a conceptual model that suggests sequential processes for browning development and desiccation of the outer scales versus processes associated with defense response and heat tolerance in the inner scale. Thus, the observed physiological differences between the outer and inner scales is supported by the identified molecular differences.

  19. Heat Acclimation and Water-Immersion Deconditioning: Responses to Exercise

    Science.gov (United States)

    Shvartz, E.; Bhattacharya, A.; Sperinde, S. J.; Brock, P. J.; Sciaraffa, D.; Haines, R. F.; Greenleaf, J. E.

    1977-01-01

    Simulated subgravity conditions, such as bed rest and water immersion, cause a decrease in a acceleration tolerance (3, 4), tilt tolerance (3, 9, 10), work capacity (5, 7), and plasma volume (1, 8-10). Moderate exercise training performed during bed rest (4) and prior to water immersion (5) provides some protection against the adverse effects of deconditioning, but the relationship between exercise and changes due to deconditioning remains unclear. Heat acclimation increases plasma and interstitial volumes, total body water, stroke volume (11), and tilt tolerance (6) and may, therefore, be a more efficient method of ameliorating deconditioning than physical training alone. The present study was undertaken to determine the effects of heat acclimation and moderate physical training, performed in cool conditions, on water-immersion deconditioning.

  20. Dynamic response of the target container under pulsed heating

    Energy Technology Data Exchange (ETDEWEB)

    Liping Ni [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1997-09-01

    The structural mechanics of a liquid target container for pulsed spallation sources have been simulated using both a commercial code and a PSI-developed program. Results from the transient thermal-structural analysis showed that, due to inertia effects, the dynamic stress in the target container is contributed mainly from direct heating in the initial time stage, and later from the pressure wave in the target liquid once it reaches the wall. (author) figs., tab., refs.

  1. Transcription of four Rhopalosiphum padi (L.) heat shock protein genes and their responses to heat stress and insecticide exposure.

    Science.gov (United States)

    Li, Yuting; Zhao, Qi; Duan, Xinle; Song, Chunman; Chen, Maohua

    2017-03-01

    The bird cherry-oat aphid, Rhopalosiphum padi (L.), a worldwide destructive pest, is more heat tolerant than other wheat aphids, and it has developed resistance to different insecticides. Heat shock proteins (HSPs) play an important role in coping with environmental stresses. To investigate Hsp transcriptional responses to heat and insecticide stress, four full-length Hsp genes from R. padi (RpHsp60, RpHsc70, RpHsp70-1, and RpHsp70-2) were cloned. Four RpHsps were expressed during all R. padi developmental stages, but at varying levels. The mRNA levels of RpHsps were increased under thermal stress and reached maximal induction at a lower temperature (36°C) in the alate morph than in the apterous morph (37°C or 38°C). RpHsp expressions under heat stress suggest that RpHsp70-1 and RpHsp70-2 are inducible in both apterous and alate morphs, RpHsc70 is only heat-inducible in apterous morph, and RpHsp60 exhibits poor sensitivity to heat stress. The pretreatment at 37°C significantly increase both the survival rate and the RpHsps expression level of R. padi at subsequent lethal temperature. Under exposure to two sublethal concentrations (LC 10 and LC 30 ) of beta-cypermethrin, both RpHsp70-1 and RpHsp70-2 expressions were induced and reached a maximum 24h after exposure. In contrast, expression of RpHsp60 was not induced by either sublethal concentration of beta-cypermethrin. Moreover, the responses of RpHsp70-1 and RpHsp70-2 to heat shock were more sensitive than those to beta-cypermethrin. These results suggest that induction of RpHsp expression is related to thermal tolerance, and that RpHsp70-1 and RpHsp70-2 are the primary genes involved in the response to both heat and pesticide stress. Copyright © 2016 Elsevier Inc. All rights reserved.

  2. Response of NSTX liquid lithium divertor to high heat loads

    Energy Technology Data Exchange (ETDEWEB)

    Abrams, T., E-mail: tabrams@pppl.gov [Princeton Plasma Physics Laboratory, Princeton, NJ 08543 (United States); Jaworski, M.A. [Princeton Plasma Physics Laboratory, Princeton, NJ 08543 (United States); Kallman, J. [Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States); Kaita, R. [Princeton Plasma Physics Laboratory, Princeton, NJ 08543 (United States); Foley, E.L. [Nova Photonics, Inc., Princeton, NJ 08543 (United States); Gray, T.K. [Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Kugel, H. [Princeton Plasma Physics Laboratory, Princeton, NJ 08543 (United States); Levinton, F. [Nova Photonics, Inc., Princeton, NJ 08543 (United States); McLean, A.G. [Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States); Skinner, C.H. [Princeton Plasma Physics Laboratory, Princeton, NJ 08543 (United States)

    2013-07-15

    Samples of the NSTX Liquid Lithium Divertor (LLD) with and without an evaporative Li coating were directly exposed to a neutral beam ex-situ at a power of ∼1.5 MW/m{sup 2} for 1–3 s. Measurements of front face and bulk sample temperature were obtained. Predictions of temperature evolution were derived from a 1D heat flux model. No macroscopic damage occurred when the “bare” sample was exposed to the beam but microscopic changes to the surface were observed. The Li-coated sample developed a lithium hydroxide (LiOH) coating, which did not change even when the front face temperature exceeded the pure Li melting point. These results are consistent with the lack of damage to the LLD surface and imply that heating alone may not expose pure liquid Li if the melting point of surface impurities is not exceeded. This suggests that flow and heat are needed for future PFCs requiring a liquid Li surface.

  3. The Adaptive Response in p53 Cancer Prone Mice: Loss of heterozygosity and Genomic Instability

    International Nuclear Information System (INIS)

    Lavoie Jose; Dolling Jo-Anna; Mitchel Ron E J; Boreham Douglas R

    2004-01-01

    The Trp53 gene is clearly associated with increased cancer risk. This, coupled with the broad understanding of its mode of action at the molecular level, makes this gene a good candidate for investigating the relationship between genetic risk factors and spontaneous cancer occurring in a mouse model exposed to low dose radiation. We have shown that adaptive response to chronic low dose radiation could increase cancer latency, as well as overall lifespan. To better understand the molecular processes that influence cellular risk, modern tools in molecular biology were used to evaluate the loss of heterozigozity (LOH) at the Trp53 locus, and chromosomal instability in the cells from mice exposed to chronic low dose radiation. Female mice carrying a single defective copy of the Trp53 gene were irradiated with doses of gamma-radiation delivered at a low dose rate of about 0.7 mGy/hr. Groups of mice (5 irradiated and 5 unexposed) were exposed to 0.33 mGy per day for 15, 30, 45, 60, 67 and 75 weeks equaling total body doses of 2.4, 4.7, 7.2, 9.7, 10.9 and 12.1 cGy, respectively. The presence of a single defective copy of the Trp53 gene increases cancer risk in these mice. However, in vivo exposure to low dose radiation increased cancer latency. We hypothesized that: (1) These mice might have spontaneous chromosome instability, and (2) that this low dose adaptive exposure would reduce the chromosomal instability. This instability was investigated using spectral karyotyping (SKY). Bone marrow cells from 5 irradiated mice (doses of 10.9 and 12.1 cGy) and 5 control mice were collected for metaphase harvest. Briefly, the cells were incubated at 37 C for 4 hours in RPMI containing 25% heat-inactivated FBS and 0.1 mg/ml colcemid, and then given a hypotonic treatment of 0.075M KCl for 20 minutes at 37 C. An average of 100 metaphases per mouse were karyotyped. The Trp53 heterozygous mice do not show apparent structural chromosome instability. From both unexposed and irradiated

  4. Predicting hearing thresholds and occupational hearing loss with multiple-frequency auditory steady-state responses.

    Science.gov (United States)

    Hsu, Ruey-Fen; Ho, Chi-Kung; Lu, Sheng-Nan; Chen, Shun-Sheng

    2010-10-01

    An objective investigation is needed to verify the existence and severity of hearing impairments resulting from work-related, noise-induced hearing loss in arbitration of medicolegal aspects. We investigated the accuracy of multiple-frequency auditory steady-state responses (Mf-ASSRs) between subjects with sensorineural hearing loss (SNHL) with and without occupational noise exposure. Cross-sectional study. Tertiary referral medical centre. Pure-tone audiometry and Mf-ASSRs were recorded in 88 subjects (34 patients had occupational noise-induced hearing loss [NIHL], 36 patients had SNHL without noise exposure, and 18 volunteers were normal controls). Inter- and intragroup comparisons were made. A predicting equation was derived using multiple linear regression analysis. ASSRs and pure-tone thresholds (PTTs) showed a strong correlation for all subjects (r = .77 ≈ .94). The relationship is demonstrated by the equationThe differences between the ASSR and PTT were significantly higher for the NIHL group than for the subjects with non-noise-induced SNHL (p tool for objectively evaluating hearing thresholds. Predictive value may be lower in subjects with occupational hearing loss. Regardless of carrier frequencies, the severity of hearing loss affects the steady-state response. Moreover, the ASSR may assist in detecting noise-induced injury of the auditory pathway. A multiple linear regression equation to accurately predict thresholds was shown that takes into consideration all effect factors.

  5. Viewing sexual images is associated with reduced physiological arousal response to gambling loss.

    Science.gov (United States)

    Lui, Ming; Hsu, Ming

    2018-01-01

    Erotic imagery is one highly salient emotional signal that exists everywhere in daily life. The impact of sexual stimuli on human decision-making, however, has rarely been investigated. This study examines the impact of sexual stimuli on financial decision-making under risk. In each trial, either a sexual or neutral image was presented in a picture categorization task before a gambling task. Thirty-four men made gambling decisions while their physiological arousal, measured by skin conductance responses (SCRs), was recorded. Behaviorally, the proportion of gambling decisions did not differ between the sexual and neutral image trials. Physiologically, participants had smaller arousal differences, measured in micro-siemen per dollar, between losses and gains in the sexual rather than in the neutral image trials. Moreover, participants' SCRs to losses relative to gains predicted the proportion of gambling decisions in the neutral image trials but not in the sexual image trials. The results were consistent with the hypothesis that the presence of emotionally salient sexual images reduces attentional and arousal-related responses to gambling losses. Our results are consistent with the theory of loss attention involving increased cognitive investment in losses compared to gains. The findings also have potential practical implications for our understanding of the specific roles of sexual images in human financial decision making in everyday life, such as gambling behaviors in the casino.

  6. Consistency and discrepancy in the atmospheric response to Arctic sea-ice loss across climate models

    Science.gov (United States)

    Screen, James A.; Deser, Clara; Smith, Doug M.; Zhang, Xiangdong; Blackport, Russell; Kushner, Paul J.; Oudar, Thomas; McCusker, Kelly E.; Sun, Lantao

    2018-03-01

    The decline of Arctic sea ice is an integral part of anthropogenic climate change. Sea-ice loss is already having a significant impact on Arctic communities and ecosystems. Its role as a cause of climate changes outside of the Arctic has also attracted much scientific interest. Evidence is mounting that Arctic sea-ice loss can affect weather and climate throughout the Northern Hemisphere. The remote impacts of Arctic sea-ice loss can only be properly represented using models that simulate interactions among the ocean, sea ice, land and atmosphere. A synthesis of six such experiments with different models shows consistent hemispheric-wide atmospheric warming, strongest in the mid-to-high-latitude lower troposphere; an intensification of the wintertime Aleutian Low and, in most cases, the Siberian High; a weakening of the Icelandic Low; and a reduction in strength and southward shift of the mid-latitude westerly winds in winter. The atmospheric circulation response seems to be sensitive to the magnitude and geographic pattern of sea-ice loss and, in some cases, to the background climate state. However, it is unclear whether current-generation climate models respond too weakly to sea-ice change. We advocate for coordinated experiments that use different models and observational constraints to quantify the climate response to Arctic sea-ice loss.

  7. Wheat yield loss attributable to heat waves, drought and water excess at the global, national and subnational scales

    Science.gov (United States)

    Zampieri, M.; Ceglar, A.; Dentener, F.; Toreti, A.

    2017-06-01

    Heat waves and drought are often considered the most damaging climatic stressors for wheat. In this study, we characterize and attribute the effects of these climate extremes on wheat yield anomalies (at global and national scales) from 1980 to 2010. Using a combination of up-to-date heat wave and drought indexes (the latter capturing both excessively dry and wet conditions), we have developed a composite indicator that is able to capture the spatio-temporal characteristics of the underlying physical processes in the different agro-climatic regions of the world. At the global level, our diagnostic explains a significant portion (more than 40%) of the inter-annual production variability. By quantifying the contribution of national yield anomalies to global fluctuations, we have found that just two concurrent yield anomalies affecting the larger producers of the world could be responsible for more than half of the global annual fluctuations. The relative importance of heat stress and drought in determining the yield anomalies depends on the region. Moreover, in contrast to common perception, water excess affects wheat production more than drought in several countries. We have also performed the same analysis at the subnational level for France, which is the largest wheat producer of the European Union, and home to a range of climatic zones. Large subnational variability of inter-annual wheat yield is mostly captured by the heat and water stress indicators, consistently with the country-level result.

  8. TG2 regulates the heat-shock response by the post-translational modification of HSF1.

    Science.gov (United States)

    Rossin, Federica; Villella, Valeria Rachela; D'Eletto, Manuela; Farrace, Maria Grazia; Esposito, Speranza; Ferrari, Eleonora; Monzani, Romina; Occhigrossi, Luca; Pagliarini, Vittoria; Sette, Claudio; Cozza, Giorgio; Barlev, Nikolai A; Falasca, Laura; Fimia, Gian Maria; Kroemer, Guido; Raia, Valeria; Maiuri, Luigi; Piacentini, Mauro

    2018-05-11

    Heat-shock factor 1 (HSF1) is the master transcription factor that regulates the response to proteotoxic stress by controlling the transcription of many stress-responsive genes including the heat-shock proteins. Here, we show a novel molecular mechanism controlling the activation of HSF1. We demonstrate that transglutaminase type 2 (TG2), dependent on its protein disulphide isomerase activity, triggers the trimerization and activation of HSF1 regulating adaptation to stress and proteostasis impairment. In particular, we find that TG2 loss of function correlates with a defect in the nuclear translocation of HSF1 and in its DNA-binding ability to the HSP70 promoter. We show that the inhibition of TG2 restores the unbalance in HSF1-HSP70 pathway in cystic fibrosis (CF), a human disorder characterized by deregulation of proteostasis. The absence of TG2 leads to an increase of about 40% in CFTR function in a new experimental CF mouse model lacking TG2. Altogether, these results indicate that TG2 plays a key role in the regulation of cellular proteostasis under stressful cellular conditions through the modulation of the heat-shock response. © 2018 The Authors.

  9. Rapid IV Versus Oral Rehydration: Responses to Subsequent Exercise Heat Stress

    National Research Council Canada - National Science Library

    Kenefick, Robert W; O'Moore, Kathleen M; Mahood, Nicholas V; Castellani, John W

    2006-01-01

    This study sought to determine the effect of rapid intravenous (IV) versus oral (ORAL) rehydration immediately after dehydration, on cardiovascular, thermoregulatory, and perceptual responses during subsequent exercise in the heat.

  10. Regimes of heating and dynamical response in driven many-body localized systems

    Science.gov (United States)

    Gopalakrishnan, Sarang; Knap, Michael; Demler, Eugene

    2016-09-01

    We explore the response of many-body localized (MBL) systems to periodic driving of arbitrary amplitude, focusing on the rate at which they exchange energy with the drive. To this end, we introduce an infinite-temperature generalization of the effective "heating rate" in terms of the spread of a random walk in energy space. We compute this heating rate numerically and estimate it analytically in various regimes. When the drive amplitude is much smaller than the frequency, this effective heating rate is given by linear response theory with a coefficient that is proportional to the optical conductivity; in the opposite limit, the response is nonlinear and the heating rate is a nontrivial power law of time. We discuss the mechanisms underlying this crossover in the MBL phase. We comment on implications for the subdiffusive thermal phase near the MBL transition, and for response in imperfectly isolated MBL systems.

  11. Hippocampal adaptive response following extensive neuronal loss in an inducible transgenic mouse model.

    Directory of Open Access Journals (Sweden)

    Kristoffer Myczek

    Full Text Available Neuronal loss is a common component of a variety of neurodegenerative disorders (including Alzheimer's, Parkinson's, and Huntington's disease and brain traumas (stroke, epilepsy, and traumatic brain injury. One brain region that commonly exhibits neuronal loss in several neurodegenerative disorders is the hippocampus, an area of the brain critical for the formation and retrieval of memories. Long-lasting and sometimes unrecoverable deficits caused by neuronal loss present a unique challenge for clinicians and for researchers who attempt to model these traumas in animals. Can these deficits be recovered, and if so, is the brain capable of regeneration following neuronal loss? To address this significant question, we utilized the innovative CaM/Tet-DT(A mouse model that selectively induces neuronal ablation. We found that we are able to inflict a consistent and significant lesion to the hippocampus, resulting in hippocampally-dependent behavioral deficits and a long-lasting upregulation in neurogenesis, suggesting that this process might be a critical part of hippocampal recovery. In addition, we provide novel evidence of angiogenic and vasculature changes following hippocampal neuronal loss in CaM/Tet-DTA mice. We posit that angiogenesis may be an important factor that promotes neurogenic upregulation following hippocampal neuronal loss, and both factors, angiogenesis and neurogenesis, can contribute to the adaptive response of the brain for behavioral recovery.

  12. Loss of Response to Anti-TNFs: Definition, Epidemiology, and Management.

    Science.gov (United States)

    Roda, Giulia; Jharap, Bindia; Neeraj, Narula; Colombel, Jean-Frederic

    2016-01-07

    Tumor necrosis factor-α (TNFα) antagonists have advanced the management of inflammatory bowel diseases patients leading to an improvement of patient's quality of life with the reduction of number of surgeries and hospitalizations. Despite these advances, many patients do not respond to the induction therapy (primary non-response-PNR) or lose response during the treatment (secondary loss of response-LOR). In this paper we will provide an overview of the definition, epidemiology and risk factors for PNR and LOR, as well as discuss the therapeutic options for managing LOR.

  13. Testing the responses of four wheat crop models to heat stress at anthesis and grain filling.

    Science.gov (United States)

    Liu, Bing; Asseng, Senthold; Liu, Leilei; Tang, Liang; Cao, Weixing; Zhu, Yan

    2016-05-01

    Higher temperatures caused by future climate change will bring more frequent heat stress events and pose an increasing risk to global wheat production. Crop models have been widely used to simulate future crop productivity but are rarely tested with observed heat stress experimental datasets. Four wheat models (DSSAT-CERES-Wheat, DSSAT-Nwheat, APSIM-Wheat, and WheatGrow) were evaluated with 4 years of environment-controlled phytotron experimental datasets with two wheat cultivars under heat stress at anthesis and grain filling stages. Heat stress at anthesis reduced observed grain numbers per unit area and individual grain size, while heat stress during grain filling mainly decreased the size of the individual grains. The observed impact of heat stress on grain filling duration, total aboveground biomass, grain yield, and grain protein concentration (GPC) varied depending on cultivar and accumulated heat stress. For every unit increase of heat degree days (HDD, degree days over 30 °C), grain filling duration was reduced by 0.30-0.60%, total aboveground biomass was reduced by 0.37-0.43%, and grain yield was reduced by 1.0-1.6%, but GPC was increased by 0.50% for cv Yangmai16 and 0.80% for cv Xumai30. The tested crop simulation models could reproduce some of the observed reductions in grain filling duration, final total aboveground biomass, and grain yield, as well as the observed increase in GPC due to heat stress. Most of the crop models tended to reproduce heat stress impacts better during grain filling than at anthesis. Some of the tested models require improvements in the response to heat stress during grain filling, but all models need improvements in simulating heat stress effects on grain set during anthesis. The observed significant genetic variability in the response of wheat to heat stress needs to be considered through cultivar parameters in future simulation studies. © 2016 John Wiley & Sons Ltd.

  14. Speech-evoked auditory brainstem responses in children with hearing loss.

    Science.gov (United States)

    Koravand, Amineh; Al Osman, Rida; Rivest, Véronique; Poulin, Catherine

    2017-08-01

    The main objective of the present study was to investigate subcortical auditory processing in children with sensorineural hearing loss. Auditory Brainstem Responses (ABRs) were recorded using click and speech/da/stimuli. Twenty-five children, aged 6-14 years old, participated in the study: 13 with normal hearing acuity and 12 with sensorineural hearing loss. No significant differences were observed for the click-evoked ABRs between normal hearing and hearing-impaired groups. For the speech-evoked ABRs, no significant differences were found for the latencies of the following responses between the two groups: onset (V and A), transition (C), one of the steady-state wave (F), and offset (O). However, the latency of the steady-state waves (D and E) was significantly longer for the hearing-impaired compared to the normal hearing group. Furthermore, the amplitude of the offset wave O and of the envelope frequency response (EFR) of the speech-evoked ABRs was significantly larger for the hearing-impaired compared to the normal hearing group. Results obtained from the speech-evoked ABRs suggest that children with a mild to moderately-severe sensorineural hearing loss have a specific pattern of subcortical auditory processing. Our results show differences for the speech-evoked ABRs in normal hearing children compared to hearing-impaired children. These results add to the body of the literature on how children with hearing loss process speech at the brainstem level. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Thermotolerance and responses to short duration heat stress in tropical and temperate species

    Science.gov (United States)

    Marias, D.; Meinzer, F. C.; Still, C. J.

    2017-12-01

    Temperature and heat waves are predicted to increase throughout the 21st century in both tropical and temperate regions. Tropical species are vulnerable to heat stress because of the higher radiation load and the narrower distribution of temperatures typically experienced compared to extratropical species. Germinant seedlings are also vulnerable to heat stress because they inhabit the boundary layer close to the soil surface where intense heating occurs. We quantified the effect of leaf age and heat stress duration (45 min, 90 min) on leaf thermotolerance and whole plant physiological responses to heat stress in Coffea arabica (COAR) saplings. We also evaluated leaf thermotolerance and whole plant responses to heat stress of seedlings in two populations each of Pinus ponderosa (PIPO) and Pseudotsuga menziesii (PSME) from contrasting climates. Thermotolerance of detached leaves/needles was evaluated using chlorophyll fluorescence (FV/FM, FO) and electrolyte leakage. After exposure of whole plants to a simulated heat wave in a growth chamber, we monitored FV/FM, photosynthesis (A), stomatal conductance (gs), non-structural carbohydrates (NSCs), and carbon isotope ratios (δ13C). In COAR, thermotolerance and rate of recovery increased with leaf age. Following heat treatment, reductions in A and gs led to reduced intrinsic water use efficiency (iWUE) and increased leaf temperatures. NSC results suggested that starch was converted to sugars for recovery from heat stress and phloem transport was inhibited. Plants failed to flower in both heat stress duration treatments. In PIPO and PSME, heat treatment induced significant reductions in FV/FM and A. NSC results suggested that starch was converted to glucose + fructose to aid recovery from heat-induced damage. Populations from drier sites had greater δ13C values than those from wetter sites, consistent with higher iWUE of populations from drier climates. Thermotolerance and heat stress responses appeared to be

  16. Ecological grief as a mental health response to climate change-related loss

    Science.gov (United States)

    Cunsolo, Ashlee; Ellis, Neville R.

    2018-04-01

    Climate change is increasingly understood to impact mental health through multiple pathways of risk, including intense feelings of grief as people suffer climate-related losses to valued species, ecosystems and landscapes. Despite growing research interest, ecologically driven grief, or `ecological grief', remains an underdeveloped area of inquiry. We argue that grief is a natural and legitimate response to ecological loss, and one that may become more common as climate impacts worsen. Drawing upon our own research in Northern Canada and the Australian Wheatbelt, combined with a synthesis of the literature, we offer future research directions for the study of ecological grief.

  17. Comparison of three different methods to prevent heat loss in healthy dogs undergoing 90 minutes of general anesthesia.

    Science.gov (United States)

    Clark-Price, Stuart C; Dossin, Olivier; Jones, Katherine R; Otto, Angela N; Weng, Hsin-Yi

    2013-05-01

    To compare a towel under, a warm water pad under or a forced warm air blanket over dogs as techniques to reduce heat loss during a standardized anesthetic. Prospective, randomized, crossover study. Eight, healthy, mixed breed dogs weighing 16.3-19.6 kg. Dogs were anesthetized four times for 90 minutes. Dogs were placed on a steel table (treatment TA), with a cotton towel (treatment TO) or a circulating warm water pad (treatment WP) between the dog and the table, or with, a towel under the dog and covered with a forced warm air blanket (treatment WAB). Rectal temperature (RT) was recorded at 5 minute intervals. Changes in temperature (ΔRT) were calculated as the RT at a given point subtracted from the RT before anesthesia (baseline) and compared over time. After 90 minutes of anesthesia, the ΔRT was 3.42 °C ± 0.29 for TA, 2.78 °C ± 0.43 for TO, 1.98 °C ± 0.29 for WP, and 0.91 °C ± 0.27 for WAB. Significant differences in ΔRT occurred between TA and WAB at 20 minutes (0.94 °C ± 0.42, p = 0.0206), between TO and WAB at 30 minutes (1.16 °C ± 0.62, p = 0.0063), between WP and WAB at 50 minutes (0.96 °C ± 0.98, p = 0.0249), between TA and WP at 35 minutes (1.19 °C ± 0.54, p = 0.0091), between TO and WP at 70 minutes (1.12 °C ± 0.56, p = 0.0248), and between TA and TO at 75 minutes (0.96 °C ± 0.62, p = 0.0313). These differences in ΔRT between each treatment persisted from the times indicated until the end of the anesthesia. During anesthesia, forced warm air blankets were superior to other methods tested for limiting heat loss. An efficient heat loss technique should be used for anesthesia longer than 20 minutes duration in medium sized dogs. © 2013 The Authors. Veterinary Anaesthesia and Analgesia © 2013 Association of Veterinary Anaesthetists and the American College of Veterinary Anesthesia and Analgesia.

  18. Bioimpedance identifies body fluid loss after exercise in the heat: a pilot study with body cooling.

    Directory of Open Access Journals (Sweden)

    Hannes Gatterer

    Full Text Available Assessment of post-exercise changes in hydration with bioimpedance (BI is complicated by physiological adaptations that affect resistance (R and reactance (Xc values. This study investigated exercise-induced changes in R and Xc, independently and in bioelectrical impedance vector analysis, when factors such as increased skin temperature and blood flow and surface electrolyte accumulation are eliminated with a cold shower.Healthy males (n = 14, 24.1±1.7 yr; height (H: 182.4±5.6 cm, body mass: 72.3±6.3 kg exercised for 1 hr at a self-rated intensity (15 BORG in an environmental chamber (33°C and 50% relative humidity, then had a cold shower (15 min. Before the run BI, body mass, hematocrit and Posm were measured. After the shower body mass was measured; BI measurements were performed continuously every 20 minutes until R reached a stable level, then hematocrit and Posm were measured again.Compared to pre-trial measurements body mass decreased after the run and Posm, Hct, R/H and Xc/H increased (p<0.05 with a corresponding lengthening of the impedance vector along the major axis of the tolerance ellipse (p<0.001. Changes in Posm were negatively related to changes in body mass (r = -0.564, p = 0.036 and changes in Xc/H (r = -0.577, p = 0.041.Present findings showed that after a bout of exercise-induced dehydration followed by cold shower the impedance vector lengthened that indicates fluid loss. Additionally, BI values might be useful to evaluate fluid shifts between compartments as lower intracellular fluid loss (changed Xc/R indicated greater Posm increase.

  19. The atmospheric heat engine response to climate change

    Science.gov (United States)

    Pauluis, O. M.

    2014-12-01

    Moist convection is characterized by complex interactions between dynamics and thermodynamics. As air parcels within the atmosphere, they experience multiple thermodynamic transformations, such as compression and expansion, diabatic heating and cooling, condensation and mixing. These transformations correspond to those of a heat engine that produces kinetic energy while transporting energy from a warm source to a colder sink. This atmospheric heat engine is however directly affected by moist processes. First, falling precipitation acts as a break on the circulation by dissipating a significant amount of kinetic energy. Second, evaporation of unsaturated water and diffusion of water vapor are irrevesible processes that also reduce the amount of work that can be produced. An important challenge is to quantify the impacts that these two effects have on the generation of kinetic energy. Here, I will introduce a new technique - the Mean Air Flow As Lagragian Dynamics Approximation (MAFALDA) - that can be used to systematically analyze the thermodynamic behavior of complex atmospheric flows. This approach relies on sorting the upward mass transport in terms of the equivalent potential temperature of the air parcels to obtain an isentropic streamfunction. This streamfunction is then used to determine the thermodynamic evolution of air parcels as they move through the atmosphere. This approach is applied to analyze how convective systems would behave in a warmer climate. It is shown that an increase in atmospheric temperature lead to a significant increase of the amount of kinetic energy that is produced per unit of mass of air transported. At the same time, the total generation of kinetic energy is only slightly affected. Taken together, these findings imply that, in a warming atmosphere, the number of intense convective events will be reduced, while their intensity should increase. I will also discuss the new possibility of systematically studying the thermodynamic

  20. Temperature response functions (G-functions) for single pile heat exchangers

    International Nuclear Information System (INIS)

    Loveridge, Fleur; Powrie, William

    2013-01-01

    Foundation piles used as heat exchangers as part of a ground energy system have the potential to reduce energy use and carbon dioxide emissions from new buildings. However, current design approaches for pile heat exchangers are based on methods developed for boreholes which have a different geometry, with a much larger aspect (length to diameter) ratio. Current methods also neglect the transient behaviour of the pile concrete, instead assuming a steady state resistance for design purposes. As piles have a much larger volume of concrete than boreholes, this neglects the significant potential for heat storage within the pile. To overcome these shortcomings this paper presents new pile temperature response functions (G-functions) which are designed to reflect typical geometries of pile heat exchangers and include the transient response of the pile concrete. Owing to the larger number of pile sizes and pipe configurations which are possible with pile heat exchangers it is not feasible to developed a single unified G-function and instead upper and lower bound solutions are provided for different aspects ratios. - Highlights: • We present new temperature response functions for pile heat exchangers. • The functions include transient heat transfer within the pile concrete. • Application of the functions reduces the resulting calculated temperature ranges. • Greater energy efficiency is possible by accounting for heat storage in the pile

  1. Network analysis of oyster transcriptome revealed a cascade of cellular responses during recovery after heat shock.

    Directory of Open Access Journals (Sweden)

    Lingling Zhang

    Full Text Available Oysters, as a major group of marine bivalves, can tolerate a wide range of natural and anthropogenic stressors including heat stress. Recent studies have shown that oysters pretreated with heat shock can result in induced heat tolerance. A systematic study of cellular recovery from heat shock may provide insights into the mechanism of acquired thermal tolerance. In this study, we performed the first network analysis of oyster transcriptome by reanalyzing microarray data from a previous study. Network analysis revealed a cascade of cellular responses during oyster recovery after heat shock and identified responsive gene modules and key genes. Our study demonstrates the power of network analysis in a non-model organism with poor gene annotations, which can lead to new discoveries that go beyond the focus on individual genes.

  2. Comparison of feed energy costs of maintenance, lean deposition, and fat deposition in three lines of mice selected for heat loss.

    Science.gov (United States)

    Eggert, D L; Nielsen, M K

    2006-02-01

    Three replications of mouse selection populations for high heat loss (MH), low heat loss (ML), and a nonselected control (MC) were used to estimate the feed energy costs of maintenance and gain and to test whether selection had changed these costs. At 21 and 49 d of age, mice were weighed and subjected to dual x-ray densitometry measurement for prediction of body composition. At 21 d, mice were randomly assigned to an ad libitum, an 80% of ad libitum, or a 60% of ad libitum feeding group for 28-d collection of individual feed intake. Data were analyzed using 3 approaches. The first approach was an attempt to partition energy intake between costs for maintenance, fat deposition, and lean deposition for each replicate, sex, and line by multiple regression of feed intake on the sum of daily metabolic weight (kg(0.75)), fat gain, and lean gain. Approach II was a less restrictive attempt to partition energy intake between costs for maintenance and total gain for each replicate, sex, and line by multiple regression of feed intake on the sum of daily metabolic weight and total gain. Approach III used multiple regression on the entire data set with pooled regressions on fat and lean gains, and subclass regressions for maintenance. Contrasts were conducted to test the effect of selection (MH - ML) and asymmetry of selection [(MH + ML)/2 - MC] for the various energy costs. In approach I, there were no differences between lines for costs of maintenance, fat deposition, or protein deposition, but we question our ability to estimate these accurately. In approach II, selection changed both cost of maintenance (P = 0.03) and gain (P = 0.05); MH mice had greater per unit costs than ML mice for both. Asymmetry of the selection response was found in approach II for the cost of maintenance (P = 0.06). In approach III, the effect of selection (P maintenance cost, but asymmetry of selection (P > 0.17) was not evident. Sex effects were found for the cost of fat deposition (P = 0.02) in

  3. Response of eddy activities to localized diabatic heating in Held-Suarez simulations

    Science.gov (United States)

    Lin, Yanluan; Zhang, Jishi; Li, Xingrui; Deng, Yi

    2018-01-01

    Widespread air pollutions, such as black carbon over East Asia in recent years, could induce a localized diabatic heating, and thus lead to localized static stability and meridional temperature gradient (MTG) changes. Although effect of static stability and MTG on eddies has been addressed by the linear baroclinic instability theory, impacts of a localized heating on mid-latitude eddy activities have not been well explored and quantified. Via a series of idealized global Held-Suarez simulations with different magnitudes of localized heating at different altitudes and latitudes, responses of mid-latitude eddy activity and circulation to these temperature perturbations are systematically investigated. Climatologically, the localized heating in the lower atmosphere induces a wave-like response of eddy activity near the mid-latitude jet stream. Over the heating region, eddy activity tends to be weakening due to the increased static stability. However, there are cyclonic anomalies over the upstream and downstream of the heating region. The zonal mean eddy activity weakens along the baroclinic zone due to reduced MTG and increased static stability. Furthermore, the response of eddy activity increased as the heating magnitude is increased and moved to higher altitudes. The influence of the heating decreases as the heating is prescribed further away from the climatological mid-latitude jet. This implies that the localized heating is most effective over the region with the maximum baroclinicity. Besides, enhanced storm track downstream of the localized heating area found here suggests that increased aerosols over East Asia might strengthen the North Pacific storm track.

  4. Responses of bat social groups to roost loss: More questions than answers

    Science.gov (United States)

    Silvis, Alexander; Abaid, Nicole; Ford, W. Mark; Britzke, Eric R.; Ortega, Jorge

    2016-01-01

    Though characterization of, and understanding determinants of, social structure in bats is increasing, little is known about how bat social groups respond to disturbance resulting in roost loss. Given that many species of bats roost in ephemeral or transitory resources such as plants, it is clear that bat social groups can tolerate some level of roost loss. Understanding responses of bat social groups to roost loss can provide insight into social structure that have applied conservation use. Herein, we review the existing literature on the effects of disturbance on bat social groups, and present a parameterizable agent-based model that can be used to explore the relationships among roost dynamics, population dynamics, and social behavior.

  5. Numerical analysis of Eucalyptus grandis × E. urophylla heat-treatment: A dynamically detecting method of mass loss during the process

    Science.gov (United States)

    Zhao, Zijian; Ma, Qing; Mu, Jun; Yi, Songlin; He, Zhengbin

    Eucalyptus particles, lamellas and boards were applied to explore a simply-implemented method with neglected heat and mass transfer to inspect the mass loss during the heat-treatment course. The results revealed that the mass loss of a certain period was theoretically the definite integration of loss rate to time in this period, and a monitoring model for mass loss speed was developed with the particles and validated with the lamellas and boards. The loss rate was correlated to the temperature and temperature-evolving speed in the model which was composed of three functions during different temperature-evolving period. The sample mass loss was calculated in the MATLAB for the lamellas and boards and the model was validated and adjusted based on the difference between the computed results and the practically measured loss values. The error ranges of the new models were -16.30% to 18.35% for wood lamellas and -9.86% to 6.80% for wood boards. This method made it possible to acquire the instantaneous loss value through continuously detecting the wood temperature evolution. This idea could provide a reference for the Eucalyptus heat-treatment to detect the treating course and control the final material characteristics.

  6. Effects of Vestibular Loss on Orthostatic Responses to Tilts in the Pitch Plane

    Science.gov (United States)

    Wood, Scott J.; Serrador, Jorge M.; Black, F. Owen; Rupert,Angus H.; Schlegel, Todd T.

    2004-01-01

    The purpose of this study was to determine the extent to which vestibular loss might impair orthostatic responses to passive tilts in the pitch plane in human subjects. Data were obtained from six subjects having chronic bilateral vestibular loss and six healthy individuals matched for age, gender, and body mass index. Vestibular loss was assessed with a comprehensive battery including dynamic posturography, vestibulo-ocular and optokinetic reflexes, vestibular evoked myogenic potentials, and ocular counterrolling. Head up tilt tests were conducted using a motorized two-axis table that allowed subjects to be tilted in the pitch plane from either a supine or prone body orientation at a slow rate (8 deg/s). The sessions consisted of three tilts, each consisting of20 min rest in a horizontal position, tilt to 80 deg upright for 10 min, and then return to the horizontal position for 5 min. The tilts were performed in darkness (supine and prone) or in light (supine only). Background music was used to mask auditory orientation cues. Autonomic measurements included beat-to-beat recordings of blood pressure (Finapres), heart rate (ECG), cerebral blood flow velocity in the middle cerebral artery (transcranial Doppler), end tidal CO2, respiratory rate and volume (Respritrace), and stroke volume (impedance cardiography). For both patients and control subjects, cerebral blood flow appeared to exhibit the most rapid adjustment following transient changes in posture. Outside of a greater cerebral hypoperfusion in patients during the later stages of tilt, responses did not differ dramatically between the vestibular loss and control subjects, or between tilts performed in light and dark room conditions. Thus, with the 'exception of cerebrovascular regulation, we conclude that orthostatic responses during slow postural tilts are not substantially impaired in humans following chronic loss of vestibular function, a result that might reflect compensation by nonvisual graviceptor

  7. Behavioral Animal Model of the Emotional Response to Tinnitus and Hearing Loss.

    Science.gov (United States)

    Lauer, Amanda M; Larkin, Gail; Jones, Aikeen; May, Bradford J

    2018-02-01

    Increased prevalence of emotional distress is associated with tinnitus and hearing loss. The underlying mechanisms of the negative emotional response to tinnitus and hearing loss remain poorly understood, and it is challenging to disentangle the emotional consequences of hearing loss from those specific to tinnitus in listeners experiencing both. We addressed these questions in laboratory rats using three common rodent anxiety screening assays: elevated plus maze, open field test, and social interaction test. Open arm activity in the elevated plus maze decreased substantially after one trial in controls, indicating its limited utility for comparing pre- and post-treatment behavior. Open field exploration and social interaction behavior were consistent across multiple sessions in control animals. Individual sound-exposed and salicylate-treated rats showed a range of phenotypes in the open field, including reduced entries into the center in some subjects and reduced locomotion overall. In rats screened for tinnitus, less locomotion was associated with higher tinnitus scores. In salicylate-treated animals, locomotion was correlated with age. Sound-exposed and salicylate-treated rats also showed reduced social interaction. These results suggest that open field exploratory activity is a selective measure for identifying tinnitus distress in individual animals, whereas social interaction reflects the general effects of hearing loss. This animal model will facilitate future studies of the structural and functional changes in the brain pathways underlying emotional distress associated with hearing dysfunction, as well as development of novel interventions to ameliorate or prevent negative emotional responses.

  8. Shifts of heat availability and stressful temperatures in Russian Federation result in gains and losses of wheat thermal suitability

    Science.gov (United States)

    Di Paola, Arianna; Caporaso, Luca; Santini, Monia; Di Paola, Francesco; Vasenev, Ivan; Valentini, Riccardo

    2017-04-01

    Climate changes are likely to shift the suitability of lands devoted to cropping systems. We explored the past-to-future thermal suitability of Russian Federation for wheat (Triticum aestivum) culture through an ensemble of bias corrected CMIP5-GCMs outputs considering two representative concentration pathways (RCP 4.5 and 8.5). Thermal suitability assesses where wheat heat requirement, counted from suggested sowing dates, is satisfied without the occurrence of stressful hot and frost temperatures. Thermal requirement was estimated by means of phenological observations on soft wheat involving different wheat cultivar collected in different regions of Russian Federation, Azerbaidhan, Kazakhstan and Tadzhikistan, whilst stressful temperatures were taken from a literature survey. Results showed projected geographical shift of heat resource toward the north-eastern regions, currently mainly covered by forests and croplands, but also an increase of very hot temperatures in the most productive areas of the southern regions. Gains and losses were then quantified and discussed from both agronomical and climatic perspective.

  9. Simple method for calculation of heat loss through floor/beam-wall intersections according to ISO 9164

    International Nuclear Information System (INIS)

    Dilmac, Sukran; Guner, Abdurrahman; Senkal, Filiz; Kartal, Semiha

    2007-01-01

    The international standards for calculation of energy consumption for heating are ISO 9164 and EN 832. Although they are based on similar principles, there are significant differences in the calculation procedure of transmission heat loss coefficient, H T , especially in the evaluation of thermal bridges. The calculation of H T and the way thermal bridges are to be taken into consideration are explained in detail in EN 832 and in a series of other linked standards. In ISO 9164, the parameters used in the relevant equations are cited, but there is a lack of explanation about how they will be determined or calculated. Although in ISO 6946-2, the earlier version of the same standard, the calculation methods of these quantities were explained for column-wall intersections; in the revised ISO 6946, these explanations have been removed. On the other hand, these parameters had never been defined for floor/beam-wall intersections. In this paper, a new method is proposed for calculation of the parameters cited in ISO 9164 for floor/beam-wall intersections. The results obtained by the proposed method for typical floor with beam sections are compared with the results obtained by the methods stated in EN 832/EN 13789/EN ISO 14683 and the results obtained from 2D analysis. Different methods are evaluated as to their simplicity and agreement

  10. Organic Matter Loading Modifies the Microbial Community Responsible for Nitrogen Loss in Estuarine Sediments.

    Science.gov (United States)

    Babbin, Andrew R; Jayakumar, Amal; Ward, Bess B

    2016-04-01

    Coastal marine sediments, as locations of substantial fixed nitrogen loss, are very important to the nitrogen budget and to the primary productivity of the oceans. Coastal sediment systems are also highly dynamic and subject to periodic natural and anthropogenic organic substrate additions. The response to organic matter by the microbial community involved in nitrogen loss processes was evaluated using mesocosms of Chesapeake Bay sediments. Over the course of a 50-day incubation, rates of anammox and denitrification were measured weekly using (15)N tracer incubations, and samples were collected for genetic analysis. Rates of both nitrogen loss processes and gene abundances associated with them corresponded loosely, probably because heterogeneities in sediments obscured a clear relationship. The rates of denitrification were stimulated more, and the fraction of nitrogen loss attributed to anammox slightly reduced, by the higher organic matter addition. Furthermore, the large organic matter pulse drove a significant and rapid shift in the denitrifier community composition as determined using a nirS microarray, indicating that the diversity of these organisms plays an essential role in responding to anthropogenic inputs. We also suggest that the proportion of nitrogen loss due to anammox in these coastal estuarine sediments may be underestimated due to temporal dynamics as well as from methodological artifacts related to conventional sediment slurry incubation approaches.

  11. RNA-Seq Reveals Extensive Transcriptional Response to Heat Stress in the Stony Coral Galaxea fascicularis

    Science.gov (United States)

    Hou, Jing; Xu, Tao; Su, Dingjia; Wu, Ying; Cheng, Li; Wang, Jun; Zhou, Zhi; Wang, Yan

    2018-01-01

    Galaxea fascicularis, a stony coral belonging to family Oculinidae, is widely distributed in Red Sea, the Gulf of Aden and large areas of the Indo-Pacific oceans. So far there is a lack of gene expression knowledge concerning this massive coral. In the present study, G. fascicularis was subjected to heat stress at 32.0 ± 0.5°C in the lab, we found that the density of symbiotic zooxanthellae decreased significantly; meanwhile apparent bleaching and tissue lysing were observed at 10 h and 18 h after heat stress. The transcriptome responses were investigated in the stony coral G. fascicularis during heat bleaching using RNA-seq. A total of 42,028 coral genes were assembled from over 439 million reads. Gene expressions were compared at 10 and 18 h after heat stress. The significantly upregulated genes found in the Control_10h vs. Heat_10h comparison, presented mainly in GO terms related with DNA integration and unfolded protein response; and for the Control_18h vs. Heat_18h comparison, the GO terms include DNA integration. In addition, comparison between groups of Control_10h vs. Heat_10h and Control_18h vs. Heat_18h revealed that 125 genes were significantly upregulated in common between the two groups, whereas 21 genes were significantly downregulated in common, all these differentially expressed genes were found to be involved in stress response, DNA integration and unfolded protein response. Taken together, our results suggest that high temperature could activate the stress response at the early stage, and subsequently induce the bleaching and lysing through DNA integration and unfolded protein response, which are able to disrupt the balance of coral-zooxanthella symbiosis in the stony coral G. fascicularis. PMID:29487614

  12. RNA-Seq Reveals Extensive Transcriptional Response to Heat Stress in the Stony Coral Galaxea fascicularis

    Directory of Open Access Journals (Sweden)

    Jing Hou

    2018-02-01

    Full Text Available Galaxea fascicularis, a stony coral belonging to family Oculinidae, is widely distributed in Red Sea, the Gulf of Aden and large areas of the Indo-Pacific oceans. So far there is a lack of gene expression knowledge concerning this massive coral. In the present study, G. fascicularis was subjected to heat stress at 32.0 ± 0.5°C in the lab, we found that the density of symbiotic zooxanthellae decreased significantly; meanwhile apparent bleaching and tissue lysing were observed at 10 h and 18 h after heat stress. The transcriptome responses were investigated in the stony coral G. fascicularis during heat bleaching using RNA-seq. A total of 42,028 coral genes were assembled from over 439 million reads. Gene expressions were compared at 10 and 18 h after heat stress. The significantly upregulated genes found in the Control_10h vs. Heat_10h comparison, presented mainly in GO terms related with DNA integration and unfolded protein response; and for the Control_18h vs. Heat_18h comparison, the GO terms include DNA integration. In addition, comparison between groups of Control_10h vs. Heat_10h and Control_18h vs. Heat_18h revealed that 125 genes were significantly upregulated in common between the two groups, whereas 21 genes were significantly downregulated in common, all these differentially expressed genes were found to be involved in stress response, DNA integration and unfolded protein response. Taken together, our results suggest that high temperature could activate the stress response at the early stage, and subsequently induce the bleaching and lysing through DNA integration and unfolded protein response, which are able to disrupt the balance of coral-zooxanthella symbiosis in the stony coral G. fascicularis.

  13. Evaluating infant core temperature response in a hot car using a heat balance model.

    Science.gov (United States)

    Grundstein, Andrew J; Duzinski, Sarah V; Dolinak, David; Null, Jan; Iyer, Sujit S

    2015-03-01

    Using a 1-year old male infant as the model subject, the objectives of this study were to measure increased body temperature of an infant inside an enclosed vehicle during the work day (8:00 am-4:00 pm) during four seasons and model the time to un-compensable heating, heat stroke [>40 °C (>104 °F)], and critical thermal maximum [>42 °C (>107.6 °F)]. A human heat balance model was used to simulate a child's physiological response to extreme heat exposure within an enclosed vehicle. Environmental variables were obtained from the nearest National Weather Service automated surface observing weather station and from an observational vehicular temperature study conducted in Austin, Texas in 2012. In all four seasons, despite differences in starting temperature and solar radiation, the model infant reached heat stroke and demise before 2:00 pm. Time to heat stroke and demise occurred most rapidly in summer, at intermediate durations in fall and spring, and most slowly in the winter. In August, the model infant reached un-compensable heat within 20 min, heat stroke within 105 min, and demise within 125 min. The average rate of heating from un-compensable heat to heat stroke was 1.7 °C/h (3.0 °F/h) and from heat stroke to demise was 4.8 °C/h (8.5 °F/h). Infants left in vehicles during the workday can reach hazardous thermal thresholds quickly even with mild environmental temperatures. These results provide a seasonal analogue of infant heat stroke time course. Further effort is required to create a universally available forensic tool to predict vehicular hyperthermia time course to demise.

  14. Optimal Scheduling of Integrated Energy Systems with Combined Heat and Power Generation, Photovoltaic and Energy Storage Considering Battery Lifetime Loss

    Directory of Open Access Journals (Sweden)

    Yongli Wang

    2018-06-01

    Full Text Available Integrated energy systems (IESs are considered a trending solution for the energy crisis and environmental problems. However, the diversity of energy sources and the complexity of the IES have brought challenges to the economic operation of IESs. Aiming at achieving optimal scheduling of components, an IES operation optimization model including photovoltaic, combined heat and power generation system (CHP and battery energy storage is developed in this paper. The goal of the optimization model is to minimize the operation cost under the system constraints. For the optimization process, an optimization principle is conducted, which achieves maximized utilization of photovoltaic by adjusting the controllable units such as energy storage and gas turbine, as well as taking into account the battery lifetime loss. In addition, an integrated energy system project is taken as a research case to validate the effectiveness of the model via the improved differential evolution algorithm (IDEA. The comparison between IDEA and a traditional differential evolution algorithm shows that IDEA could find the optimal solution faster, owing to the double variation differential strategy. The simulation results in three different battery states which show that the battery lifetime loss is an inevitable factor in the optimization model, and the optimized operation cost in 2016 drastically decreased compared with actual operation data.

  15. Gustatory tissue injury in man: radiation dose response relationships and mechanisms of taste loss

    International Nuclear Information System (INIS)

    Mossman, K.L.

    1986-01-01

    In this report dose response data for gustatory tissue damage in patients given total radiation doses ranging from 3000 to 6000 cGy are presented. In order to evaluate direct radiation injury to gustatory tissues as a mechanism of taste loss, measurements of damage to specific taste structures in bovine and murine systems following radiation exposure in the clinical range are correlated to taste impairment observed in radiotherapy patients. (author)

  16. NOy production, ozone loss and changes in net radiative heating due to energetic particle precipitation in 2002-2010

    Science.gov (United States)

    Sinnhuber, Miriam; Berger, Uwe; Funke, Bernd; Nieder, Holger; Reddmann, Thomas; Stiller, Gabriele; Versick, Stefan; von Clarmann, Thomas; Maik Wissing, Jan

    2018-01-01

    winter, ranging from 10-50 % during solar maximum to 2-10 % during solar minimum. Ozone loss continues throughout polar summer after strong solar proton events in the Southern Hemisphere and after large sudden stratospheric warmings in the Northern Hemisphere. During mid-winter, the ozone loss causes a reduction of the infrared radiative cooling, i.e., a positive change of the net radiative heating (effective warming), in agreement with analyses of geomagnetic forcing in stratospheric temperatures which show a warming in the late winter upper stratosphere. In late winter and spring, the sign of the net radiative heating change turns to negative (effective cooling). This spring-time cooling lasts well into summer and continues until the following autumn after large solar proton events in the Southern Hemisphere, and after sudden stratospheric warmings in the Northern Hemisphere.

  17. HSF1 and HSF3 cooperatively regulate the heat shock response in lizards.

    Science.gov (United States)

    Takii, Ryosuke; Fujimoto, Mitsuaki; Matsuura, Yuki; Wu, Fangxu; Oshibe, Namiko; Takaki, Eiichi; Katiyar, Arpit; Akashi, Hiroshi; Makino, Takashi; Kawata, Masakado; Nakai, Akira

    2017-01-01

    Cells cope with temperature elevations, which cause protein misfolding, by expressing heat shock proteins (HSPs). This adaptive response is called the heat shock response (HSR), and it is regulated mainly by heat shock transcription factor (HSF). Among the four HSF family members in vertebrates, HSF1 is a master regulator of HSP expression during proteotoxic stress including heat shock in mammals, whereas HSF3 is required for the HSR in birds. To examine whether only one of the HSF family members possesses the potential to induce the HSR in vertebrate animals, we isolated cDNA clones encoding lizard and frog HSF genes. The reconstructed phylogenetic tree of vertebrate HSFs demonstrated that HSF3 in one species is unrelated with that in other species. We found that the DNA-binding activity of both HSF1 and HSF3 in lizard and frog cells was induced in response to heat shock. Unexpectedly, overexpression of lizard and frog HSF3 as well as HSF1 induced HSP70 expression in mouse cells during heat shock, indicating that the two factors have the potential to induce the HSR. Furthermore, knockdown of either HSF3 or HSF1 markedly reduced HSP70 induction in lizard cells and resistance to heat shock. These results demonstrated that HSF1 and HSF3 cooperatively regulate the HSR at least in lizards, and suggest complex mechanisms of the HSR in lizards as well as frogs.

  18. Molecular cloning, phylogenetic analysis and heat shock response of Babesia gibsoni heat shock protein 90.

    Science.gov (United States)

    Yamasaki, Masahiro; Tsuboi, Yoshihiro; Taniyama, Yusuke; Uchida, Naohiro; Sato, Reeko; Nakamura, Kensuke; Ohta, Hiroshi; Takiguchi, Mitsuyoshi

    2016-09-01

    The Babesia gibsoni heat shock protein 90 (BgHSP90) gene was cloned and sequenced. The length of the gene was 2,610 bp with two introns. This gene was amplified from cDNA corresponding to full length coding sequence (CDS) with an open reading frame of 2,148 bp. A phylogenetic analysis of the CDS of HSP90 gene showed that B. gibsoni was most closely related to B. bovis and Babesia sp. BQ1/Lintan and lies within a phylogenetic cluster of protozoa. Moreover, mRNA transcription profile for BgHSP90 exposed to high temperature were examined by quantitative real-time reverse transcription-polymerase chain reaction. BgHSP90 levels were elevated when the parasites were incubated at 43°C for 1 hr.

  19. Domestic hot water. Measurements of consumption and heat loss from circulation pipes; Varmt brugsvand. Maaling af forbrug og varmetab fra cirkulationsledninger

    Energy Technology Data Exchange (ETDEWEB)

    Boehm, B.; Schroeder, F.; Bergsoee, N.C.

    2009-07-01

    It is likely that the production and distribution of domestic hot water (DHW) in buildings will constitute a dominant share of both the present and in particular future energy design requirements. The goal of this project has been to propose more energy efficient and environmentally friendly solutions for DHW systems based on analyses of existing conditions. The possibilities include new types of circulation pipes, which have the potential of a 40 per cent reduction of heat losses. In addition to the reduction of heat losses inside the building, a low return temperature from the hot water system will have a large impact on the heat losses from the district heating network when the building is being heated by district heating. The results of this project could influence not only future buildings but also existing buildings in case of renovation of the installations. In this project measurements of water and energy consumptions have been carried out in a number of buildings, and heat losses from the production of domestic hot water and the distribution lines have been measured. In addition to the measurements, analyses and simulations have been carried out. Two models have been developed: One of an apartment room with vertical pipes passing through the room, and one of a room above a basement with horizontal heating pipes. The models make it possible to assess how much of the heat loss from the heating pipes is utilised for space heating. The following recommendations are pointed out: 1) In large buildings e.g. apartment buildings and office buildings the technical installations should be provided with meters so that it is possible to separate the energy consumption for DHW, space heating and ventilation, respectively. 2) In new buildings and in case of retrofitting existing buildings, careful planning of the placement and disposition of hot water taps compared with the location of the hot water tank or heat exchanger is recommended. Also, the necessity of a

  20. Rising Mercury, Rising Hostility: How Heat Affects Survey Response

    Science.gov (United States)

    Cohen, Alexander H.; Krueger, James S.

    2016-01-01

    Recent social scientific research has examined connections between public opinion and weather conditions. This article contributes to this literature by analyzing the relationship between high temperature and survey response. Because hot temperatures are associated with aggression, irritation, and negativity, such conditions should lead to the…

  1. Fungistatic activity of heat-treated flaxseed determined by response surface methodology.

    Science.gov (United States)

    Xu, Y; Hall, C; Wolf-Hall, C

    2008-08-01

    The objective of this study was to evaluate the effect of heat treatment on the fungistatic activity of flaxseed (Linum usitatissimum) in potato dextrose agar (PDA) medium and a fresh noodle system. The radial growth of Penicilliumn chrysogenum, Aspergillus flavus, and a Penicillium sp. isolated from moldy noodles, as well as the mold count of fresh noodle enriched with heat treated flaxseed, were used to assess antifungal activity. A central composite design in the response surface methodology was used to predict the effect of heating temperature and time on antifungal activity of flaxseed flour (FF). Statistical analysis determined that the linear terms of both variables (that is, heating temperature and time) and the quadratic terms of the heating temperature had significant (P<0.05) effects on the radial growth of all 3 test fungi and the mold count log-cycle reduction of fresh noodle. The interactions between the temperature and time were significant for all dependent variables (P<0.05). Significant reductions in antifungal activities were found when FF was subjected to high temperatures, regardless of heating time. In contrast, prolonging the heating time did not substantially affect the antifungal activities of FF at low temperature. However, 60% of the antifungal activity was retained after FF was heated at 100 degrees C for 15 min, which suggests a potential use of FF as an antifungal additive in food products subjected to low to mild heat treatments.

  2. The role of PKA in the translational response to heat stress in Saccharomyces cerevisiae.

    Directory of Open Access Journals (Sweden)

    Carla E Barraza

    Full Text Available Cellular responses to stress stem from a variety of different mechanisms, including translation arrest and relocation of the translationally repressed mRNAs to ribonucleoprotein particles like stress granules (SGs and processing bodies (PBs. Here, we examine the role of PKA in the S. cerevisiae heat shock response. Under mild heat stress Tpk3 aggregates and promotes aggregation of eIF4G, Pab1 and eIF4E, whereas severe heat stress leads to the formation of PBs and SGs that contain both Tpk2 and Tpk3 and a larger 48S translation initiation complex. Deletion of TPK2 or TPK3 impacts upon the translational response to heat stress of several mRNAs including CYC1, HSP42, HSP30 and ENO2. TPK2 deletion leads to a robust translational arrest, an increase in SGs/PBs aggregation and translational hypersensitivity to heat stress, whereas TPK3 deletion represses SGs/PBs formation, translational arrest and response for the analyzed mRNAs. Therefore, this work provides evidence indicating that Tpk2 and Tpk3 have opposing roles in translational adaptation during heat stress, and highlight how the same signaling pathway can be regulated to generate strikingly distinct physiological outputs.

  3. Prediction of postoperative pain by preoperative pain response to heat stimulation in total knee arthroplasty

    DEFF Research Database (Denmark)

    Lunn, Troels H; Gaarn-Larsen, Lissi; Kehlet, Henrik

    2013-01-01

    It has been estimated that up to 54% of the variance in postoperative pain experience may be predicted with preoperative pain responses to experimental stimuli, with suprathreshold heat pain as the most consistent test modality. We aimed to explore if 2 heat test paradigms could predict postopera......It has been estimated that up to 54% of the variance in postoperative pain experience may be predicted with preoperative pain responses to experimental stimuli, with suprathreshold heat pain as the most consistent test modality. We aimed to explore if 2 heat test paradigms could predict...... and logistic regressions analyses were carried out including 8 potential preoperative explanatory variables (among these anxiety, depression, preoperative pain and pain catastrophizing) to assess pain response to preoperative heat pain stimulation as independent predictor for postoperative pain. 100 patients...... by the linear and logistic regression analyses, where only anxiety, preoperative pain and pain catastrophizing were significant explanatory variables (but with low R-Squares;0.05-0.08). Pain responses to 2 types of preoperative heat stimuli were not independent clinical relevant predictors for postoperative...

  4. Effect of a patent foramen ovale in humans on thermal responses to passive cooling and heating.

    Science.gov (United States)

    Davis, James T; Hay, Madeline W; Hardin, Alyssa M; White, Matthew D; Lovering, Andrew T

    2017-12-01

    Humans with a patent foramen ovale (PFO) have a higher esophageal temperature (T esoph ) than humans without a PFO (PFO-). Thus the presence of a PFO might also be associated with differences in thermal responsiveness to passive cooling and heating such as shivering and hyperpnea, respectively. The purpose of this study was to determine whether thermal responses to passive cooling and heating are different between PFO- subjects and subjects with a PFO (PFO+). We hypothesized that compared with PFO- subjects PFO+ subjects would cool down more rapidly and heat up slower and that PFO+ subjects who experienced thermal hyperpnea would have a blunted increase in ventilation. Twenty-seven men (13 PFO+) completed two trials separated by >48 h: 1 ) 60 min of cold water immersion (19.5 ± 0.9°C) and 2 ) 30 min of hot water immersion (40.5 ± 0.2°C). PFO+ subjects had a higher T esoph before and during cold water and hot water immersion ( P heating. NEW & NOTEWORTHY Patent foramen ovale (PFO) is found in ~25-40% of the population. The presence of a PFO appears to be associated with a greater core body temperature and blunted ventilatory responses during passive heating. The reason for this blunted ventilatory response to passive heating is unknown but may suggest differences in thermal sensitivity in PFO+ subjects compared with PFO- subjects. Copyright © 2017 the American Physiological Society.

  5. Comparison of the heat treatment response of wrought and SSM-HPDC alloy 6082

    CSIR Research Space (South Africa)

    Möller, H

    2011-06-01

    Full Text Available The natural and artificial aging responses of wrought and SSM-HPDC alloy 6082 are compared. It is shown that the heat treatment response of this Al-Mg-Si alloy is not influenced by differences in microstructures produced by different processing...

  6. Relationships between drought, heat and air humidity responses revealed by transcriptome-metabolome co-analysis.

    Science.gov (United States)

    Georgii, Elisabeth; Jin, Ming; Zhao, Jin; Kanawati, Basem; Schmitt-Kopplin, Philippe; Albert, Andreas; Winkler, J Barbro; Schäffner, Anton R

    2017-07-10

    Elevated temperature and reduced water availability are frequently linked abiotic stresses that may provoke distinct as well as interacting molecular responses. Based on non-targeted metabolomic and transcriptomic measurements from Arabidopsis rosettes, this study aims at a systematic elucidation of relevant components in different drought and heat scenarios as well as relationships between molecular players of stress response. In combined drought-heat stress, the majority of single stress responses are maintained. However, interaction effects between drought and heat can be discovered as well; these relate to protein folding, flavonoid biosynthesis and growth inhibition, which are enhanced, reduced or specifically induced in combined stress, respectively. Heat stress experiments with and without supplementation of air humidity for maintenance of vapor pressure deficit suggest that decreased relative air humidity due to elevated temperature is an important component of heat stress, specifically being responsible for hormone-related responses to water deprivation. Remarkably, this "dry air effect" is the primary trigger of the metabolomic response to heat. In contrast, the transcriptomic response has a substantial temperature component exceeding the dry air component and including up-regulation of many transcription factors and protein folding-related genes. Data level integration independent of prior knowledge on pathways and condition labels reveals shared drought and heat responses between transcriptome and metabolome, biomarker candidates and co-regulation between genes and metabolic compounds, suggesting novel players in abiotic stress response pathways. Drought and heat stress interact both at transcript and at metabolite response level. A comprehensive, non-targeted view of this interaction as well as non-interacting processes is important to be taken into account when improving tolerance to abiotic stresses in breeding programs. Transcriptome and metabolome

  7. Babcock and Wilcox revisions to CONTEMPT, computer program for predicting containment pressure-temperature response to a loss-of-coolant accident

    International Nuclear Information System (INIS)

    Hsii, Y.H.

    1976-06-01

    The CONTEMPT computer program predicts the pressure-temperature response of a single-volume reactor building to a loss-of-coolant accident. The report describes the analytical model used for the program. CONTEMPT assumes that the loss-of-coolant accident can be separated into two phases; the primary system blowdown and reactor building pressurization. The results of the blowdown analysis serve as the boundary conditions and are input to the CONTEMPT program. Thus, the containment model is only concerned with the pressure and temperature in the reactor building and the temperature distribution through the reactor building structures. The user is required to input the description of the discharge of coolant, the boiling of residual water by reactor decay heat, the superheating of steam passing through the core, and metal-water reactions. The reactor building is separated into liquid and vapor regions. Each region is in thermal equilibrium itself, but the two may not be in thermal equilibrium; the liquid and gaseous regions may have different temperatures. The reactor building is represented as consisting of several heat-conducting structures whose thermal behavior can be described by the one-dimensional multi-region heat conduction equation. The program also calculates building leakage and the effects of engineered safety features such as reactor building sprays, decay heat coolers, sump coolers, etc

  8. Owners’ Perceptions of Their Animal’s Behavioural Response to the Loss of an Animal Companion

    Directory of Open Access Journals (Sweden)

    Jessica K. Walker

    2016-11-01

    Full Text Available The loss of a companion animal is recognised as being associated with experiences of grief by the owner, but it is unclear how other animals in the household may be affected by such a loss. Our aim was to investigate companion animals’ behavioural responses to the loss of a companion through owner-report. A questionnaire was distributed via, and advertised within, publications produced by the Royal Society for the Prevention of Cruelty to Animals (RSPCA across Australia and New Zealand, and through a selection of veterinary clinics within New Zealand. A total of 279 viable surveys were returned pertaining to 159 dogs and 152 cats. The two most common classes of behavioural changes reported for both dogs and cats were affectionate behaviours (74% of dogs and 78% of cats and territorial behaviours (60% of dogs and 63% of cats. Both dogs and cats were reported to demand more attention from their owners and/or display affiliative behaviour, as well as spend time seeking out the deceased’s favourite spot. Dogs were reported to reduce the volume (35% and speed (31% of food consumption and increase the amount of time spent sleeping (34%. Cats were reported to increase the frequency (43% and volume (32% of vocalisations following the death of a companion. The median duration of reported behavioural changes in both species was less than 6 months. There was consensus that the behaviour of companion animals changed in response to the loss of an animal companion. These behavioural changes suggest the loss had an impact on the remaining animal.

  9. Owners' Perceptions of Their Animal's Behavioural Response to the Loss of an Animal Companion.

    Science.gov (United States)

    Walker, Jessica K; Waran, Natalie K; Phillips, Clive J C

    2016-11-03

    The loss of a companion animal is recognised as being associated with experiences of grief by the owner, but it is unclear how other animals in the household may be affected by such a loss. Our aim was to investigate companion animals' behavioural responses to the loss of a companion through owner-report. A questionnaire was distributed via, and advertised within, publications produced by the Royal Society for the Prevention of Cruelty to Animals (RSPCA) across Australia and New Zealand, and through a selection of veterinary clinics within New Zealand. A total of 279 viable surveys were returned pertaining to 159 dogs and 152 cats. The two most common classes of behavioural changes reported for both dogs and cats were affectionate behaviours (74% of dogs and 78% of cats) and territorial behaviours (60% of dogs and 63% of cats). Both dogs and cats were reported to demand more attention from their owners and/or display affiliative behaviour, as well as spend time seeking out the deceased's favourite spot. Dogs were reported to reduce the volume (35%) and speed (31%) of food consumption and increase the amount of time spent sleeping (34%). Cats were reported to increase the frequency (43%) and volume (32%) of vocalisations following the death of a companion. The median duration of reported behavioural changes in both species was less than 6 months. There was consensus that the behaviour of companion animals changed in response to the loss of an animal companion. These behavioural changes suggest the loss had an impact on the remaining animal.

  10. Systemic Inflammatory Response to Malaria During Pregnancy Is Associated With Pregnancy Loss and Preterm Delivery.

    Science.gov (United States)

    Fried, Michal; Kurtis, Jonathan D; Swihart, Bruce; Pond-Tor, Sunthorn; Barry, Amadou; Sidibe, Youssoufa; Gaoussou, Santara; Traore, Moussa; Keita, Sekouba; Mahamar, Almahamoudou; Attaher, Oumar; Dembele, Adama B; Cisse, Kadidia B; Diarra, Bacary S; Kanoute, Moussa B; Dicko, Alassane; Duffy, Patrick E

    2017-10-30

    Pregnancy malaria (PM) is associated with a proinflammatory immune response characterized by increased levels of cytokines and chemokines such as tumor necrosis factor-α, interferon-γ, interleukin 10 (IL-10), and CXCL9. These changes are associated with poor outcomes including low birthweight delivery and maternal anemia. However, it is unknown if inflammatory pathways during malaria are related to pregnancy loss and preterm delivery (PTD). Cytokine and chemokine levels were measured in maternal peripheral blood at enrollment, gestational week 30-32, and delivery, and in placental blood, of 638 women during a longitudinal cohort study in Ouelessebougou, Mali. Plasmodium falciparum infection was assessed by blood smear microscopy at all visits. PM was associated with increased levels of cytokines and chemokines including IL-10 and CXCL9. In a competing risks model adjusted for known covariates, high CXCL9 levels measured in the peripheral blood during pregnancy were associated with increased risk of pregnancy loss and PTD. At delivery, high IL-10 levels in maternal blood were associated with an increase in pregnancy loss, and increased IL-1β levels in placental blood were associated with pregnancy loss and PTD. PM is associated with increased proinflammatory cytokine and chemokine levels in placental and maternal peripheral blood. Systemic inflammatory responses to malaria during pregnancy predict increased risk of pregnancy loss and PTD. NCT01168271. Published by Oxford University Press for the Infectious Diseases Society of America 2017. This work is written by (a) US Government employee(s) and is in the public domain in the US.

  11. The Neural Responses to Social Cooperation in Gain and Loss Context.

    Directory of Open Access Journals (Sweden)

    Peng Sun

    Full Text Available Cooperation is pervasive and constitutes the core behavioral principle of human social life. Previous studies have revealed that mutual cooperation was reliably correlated with two reward-related brain regions, the ventral striatum and the orbitofrontal cortex. Using functional magnetic resonance imaging (fMRI, this study sought to investigate how the loss and gain contexts modulated the neural responses to mutual cooperation. Twenty-five female participants were scanned when they played a series of one-shot prisoner's dilemma games in the loss and gain contexts. Specifically, participants and partners independently chose to either cooperate with each other or not, and each was awarded or deprived of (in the gain context or the loss context, respectively a sum of money which depended upon the interaction of their choices. Behavioral results indicated that participants cooperated in nearly half of the experiment trials and reported higher level of positive emotions for mutual cooperation in both contexts, but they cooperated more in the gain than in the loss context. At the neural level, stronger activities in the orbitofrontal cortex were observed for mutual cooperation compared with the other three outcomes in both contexts, while stronger activation in ventral striatum associated with mutual cooperation was observed in the gain context only. Together, our data indicated that, even in the one-shot interaction under loss context, participants still exhibited preference for cooperation and the rewarding experience from a mutually cooperative social interaction activated the ventral striatum and the orbitofrontal cortex, but the loss context weakened the association between the ventral striatum activation and mutual cooperation.

  12. Contempt-LT: a computer program for predicting containment pressure-temperature response to a loss-of-coolant accident

    International Nuclear Information System (INIS)

    Wheat, L.L.; Wagner, R.J.; Niederauer, G.F.; Obenchain, C.F.

    1975-06-01

    CONTEMPT-LT is a digital computer program, written in FORTRAN IV, developed to describe the long-term behavior of water-cooled nuclear reactor containment systems subjected to postulated loss-of-coolant accident (LOCA) conditions. The program calculates the time variation of compartment pressures, temperatures, mass and energy inventories, heat structure temperature distributions, and energy exchange with adjacent compartments. The program is capable of describing the effects of leakage on containment response. Models are provided to describe fan cooler and cooling spray engineered safety systems. Up to four compartments can be modeled with CONTEMPT-LT, and any compartment except the reactor system may have both a liquid pool region and an air-vapor atmosphere region above the pool. Each region is assumed to have a uniform temperature, but the temperatures of the two regions may be different. CONTEMPT-LT can be used to model all current boiling water reactor pressure suppression systems, including containments with either vertical or horizontal vent systems. CONTEMPT-LT can also be used to model pressurized water reactor dry containments, subatmospheric containments, and dual volume containments with an annulus region, and can be used to describe containment responses in experimental containment systems. The program user defines which compartments are used, specifies input mass and energy additions, defines heat structure and leakage systems, and describes the time advancement and output control. CONTEMPT-LT source decks are available in double precision extended-binary-coded-decimal-interchange-code (EBCDIC) versions. Sample problems have been run on the IBM360/75 computer. (U.S.)

  13. Occupational heat stress and associated productivity loss estimation using the PHS model (ISO 7933): a case study from workplaces in Chennai, India.

    Science.gov (United States)

    Lundgren, Karin; Kuklane, Kalev; Venugopal, Vidhya

    2014-01-01

    Heat stress is a major occupational problem in India that can cause adverse health effects and reduce work productivity. This paper explores this problem and its impacts in selected workplaces, including industrial, service, and agricultural sectors in Chennai, India. Quantitative measurements of heat stress, workload estimations, and clothing testing, and qualitative information on health impacts, productivity loss, etc., were collected. Heat strain and associated impacts on labour productivity between the seasons were assessed using the International Standard ISO 7933:2004, which applies the Predicted Heat Strain (PHS) model. All workplaces surveyed had very high heat exposure in the hot season (Wet Bulb Globe Temperature =29.7), often reaching the international standard safe work values (ISO 7243:1989). Most workers had moderate to high workloads (170-220 W/m2), with some exposed to direct sun. Clothing was found to be problematic, with high insulation values in relation to the heat exposure. Females were found to be more vulnerable because of the extra insulation added from wearing a protective shirt on top of traditional clothing (0.96 clo) while working. When analysing heat strain--in terms of core temperature and dehydration--and associated productivity loss in the PHS model, the parameters showed significant impacts that affected productivity in all workplaces, apart from the laundry facility, especially during the hot season. For example, in the canteen, the core temperature limit of 38°C predicted by the model was reached in only 64 min for women. With the expected increases in temperature due to climate change, additional preventive actions have to be implemented to prevent further productivity losses and adverse health impacts. Overall, this study presented insight into using a thermo-physiological model to estimate productivity loss due to heat exposure in workplaces. This is the first time the PHS model has been used for this purpose. An exploratory

  14. Influence of variable oxygen concentration on the response of cells to heat or x irradiation

    International Nuclear Information System (INIS)

    Gerweck, L.E.; Richards, B.; Jennings, M.

    1981-01-01

    The influence of oxygen concentration on the lethal response of cells exposed to 43 0 C hyperthermia was determined and compared to the response of cells exposed to radiation under equivalent culturing and environmental conditions. Chinese hamster ovary (CHO) cells were heated or irradiated 0.5 h after induction of hypoxia and then reoxygenated following treatment. The oxygen enhancement ratio (OER) for heat or radiation was determined at the 1% survival level from least-squares fit of survival curves. A maximum OER of 3.1 +- 0.2 was observed in the 20 to 95% oxygen concentration range. The OER for heat, however, was 1.0 +- 0.1 irrespective of the gas-phase oxygen concentration. These results show that the lethal effects of heat are not influenced by the oxygen concentration at the time of treatment in CHO cells exposed to 43 0 C hyperthermia

  15. Fourier and non-Fourier bio-heat transfer models to predict ex vivo temperature response to focused ultrasound heating

    Science.gov (United States)

    Li, Chenghai; Miao, Jiaming; Yang, Kexin; Guo, Xiasheng; Tu, Juan; Huang, Pintong; Zhang, Dong

    2018-05-01

    Although predicting temperature variation is important for designing treatment plans for thermal therapies, research in this area is yet to investigate the applicability of prevalent thermal conduction models, such as the Pennes equation, the thermal wave model of bio-heat transfer, and the dual phase lag (DPL) model. To address this shortcoming, we heated a tissue phantom and ex vivo bovine liver tissues with focused ultrasound (FU), measured the temperature response, and compared the results with those predicted by these models. The findings show that, for a homogeneous-tissue phantom, the initial temperature increase is accurately predicted by the Pennes equation at the onset of FU irradiation, although the prediction deviates from the measured temperature with increasing FU irradiation time. For heterogeneous liver tissues, the predicted response is closer to the measured temperature for the non-Fourier models, especially the DPL model. Furthermore, the DPL model accurately predicts the temperature response in biological tissues because it increases the phase lag, which characterizes microstructural thermal interactions. These findings should help to establish more precise clinical treatment plans for thermal therapies.

  16. Preliminary study on the forgeability and heat treatment response of niobium - containing tool steels materials

    International Nuclear Information System (INIS)

    Cescon, T.; Papaleo, R.

    1981-01-01

    The forgeability and microstructure of tool steels materials based on the M-2 composition, where W and V were partially replaced by Nb, were examined. The optimum heat-treating conditions were established. The poor response to heat treatment of some of the alloys studied indicated the need of increasing the C content of the steels when Nb is used as a substitute for W and V. (Author) [pt

  17. Chicken hepatic response to chronic heat stress using integrated transcriptome and metabolome analysis.

    Directory of Open Access Journals (Sweden)

    Sara F Jastrebski

    Full Text Available The liver plays a central role in metabolism and is important in maintaining homeostasis throughout the body. This study integrated transcriptomic and metabolomic data to understand how the liver responds under chronic heat stress. Chickens from a rapidly growing broiler line were heat stressed for 8 hours per day for one week and liver samples were collected at 28 days post hatch. Transcriptome analysis reveals changes in genes responsible for cell cycle regulation, DNA replication, and DNA repair along with immune function. Integrating the metabolome and transcriptome data highlighted multiple pathways affected by heat stress including glucose, amino acid, and lipid metabolism along with glutathione production and beta-oxidation.

  18. Specific microRNAs Regulate Heat Stress Responses in Caenorhabditis elegans

    DEFF Research Database (Denmark)

    Nehammer, Camilla; Podolska, Agnieszka; Mackowiak, Sebastian D

    2015-01-01

    have identified additional functions for already known players (mir-71 and mir-239) as well as identifying mir-80 and the mir-229 mir-64-66 cluster as important regulators of the heat stress response in C. elegans. These findings uncover an additional layer of complexity to the regulation of stress...... to heat stress in Caenorhabditis elegans and show that a discrete subset of miRNAs is thermoregulated. Using in-depth phenotypic analyses of miRNA deletion mutant strains we reveal multiple developmental and post-developmental survival and behavioral functions for specific miRNAs during heat stress. We...

  19. Exploring the heat-responsive chaperones and microsatellite markers associated with terminal heat stress tolerance in developing wheat.

    Science.gov (United States)

    Kumar, Ranjeet R; Goswami, Suneha; Shamim, Mohammad; Dubey, Kavita; Singh, Khushboo; Singh, Shweta; Kala, Yugal K; Niraj, Ravi R K; Sakhrey, Akshay; Singh, Gyanendra P; Grover, Monendra; Singh, Bhupinder; Rai, Gyanendra K; Rai, Anil K; Chinnusamy, Viswanathan; Praveen, Shelly

    2017-11-01

    Global warming is a major threat for agriculture and food security, and in many cases the negative impacts are already apparent. Wheat is one of the most important staple food crops and is highly sensitive to the heat stress (HS) during reproductive and grain-filling stages. Here, whole transcriptome analysis of thermotolerant wheat cv. HD2985 was carried out at the post-anthesis stage under control (22 ± 3 °C) and HS-treated (42 °C, 2 h) conditions using Illumina Hiseq and Roche GS-FLX 454 platforms. We assembled ~24 million (control) and ~23 million (HS-treated) high-quality trimmed reads using different assemblers with optimal parameters. De novo assembly yielded 52,567 (control) and 59,658 (HS-treated) unigenes. We observed 785 transcripts to be upregulated and 431 transcripts to be downregulated under HS; 78 transcripts showed >10-fold upregulation such as HSPs, metabolic pathway-related genes, etc. Maximum number of upregulated genes was observed to be associated with processes such as HS-response, protein-folding, oxidation-reduction and photosynthesis. We identified 2008 and 2483 simple sequence repeats (SSRs) markers from control and HS-treated samples; 243 SSRs were observed to be overlying on stress-associated genes. Polymorphic study validated four SSRs to be heat-responsive in nature. Expression analysis of identified differentially expressed transcripts (DETs) showed very high fold increase in the expression of catalytic chaperones (HSP26, HSP17, and Rca) in contrasting wheat cvs. HD2985 and HD2329 under HS. We observed positive correlation between RNA-seq and qRT-PCR expression data. The present study culminated in greater understanding of the heat-response of tolerant genotype and has provided good candidate genes for the marker development and screening of wheat germplasm for thermotolerance.

  20. Dependence of the coefficient of environmental thermal losses of radiation-absorbing thermal exchange panels of flat solar collectors for heating heat-transfer fluid from their average operating and ambient temperatures

    International Nuclear Information System (INIS)

    Avezova, N.R.; Avezov, R.R.

    2015-01-01

    The approximation formula is derived for calculating the normalized coefficient of thermal losses of flat solar collectors (FSCs) for heating heat-transfer fluid (HTF). These are used in hot water supply systems in the warmer part of the year, depending on the average working surface temperature of their radiation-absorbing thermal exchange panels (RATEPs) (t"-_w_s_r) and the ambient temperature (t_a_m_b) in their realistic variation range. (author)

  1. An efficient approach to characterizing and calculating carrier loss due to heating and barrier height variation in vertical-cavity surface-emitting lasers

    International Nuclear Information System (INIS)

    Jian, Wu; Summers, H. D.

    2010-01-01

    It is important to determine quantitatively the internal carrier loss arising from heating and barrier height variation in a vertical-cavity surface-emitting quantum well laser (VCSEL). However, it is generally difficult to realize this goal using purely theoretical formulas due to difficulty in deriving the parameters relating to the quantum well structure. In this paper, we describe an efficient approach to characterizing and calculating the carrier loss due to the heating and the barrier height change in the VCSEL. In the method, the thermal carrier loss mechanism is combined with gain measurement and calculation. The carrier loss is re-characterized in a calculable form by constructing the threshold current and gain detuning-related loss current using the measured gain data and then substituting them for the quantum well-related parameters in the formula. The result can be expressed as a product of an exponential weight factor linked to the barrier height change and the difference between the threshold current and gain detuning-related loss current. The gain variation at cavity frequency due to thermal carrier loss and gain detuning processes is measured by using an AlInGaAs–AlGaAs VCSEL structure. This work provides a useful approach to analysing threshold and loss properties of the VCSEL, particularly, gain offset design for high temperature operation of VCSELs. (classical areas of phenomenology)

  2. How a retrotransposon exploits the plant's heat stress response for its activation.

    Directory of Open Access Journals (Sweden)

    Vladimir V Cavrak

    2014-01-01

    Full Text Available Retrotransposons are major components of plant and animal genomes. They amplify by reverse transcription and reintegration into the host genome but their activity is usually epigenetically silenced. In plants, genomic copies of retrotransposons are typically associated with repressive chromatin modifications installed and maintained by RNA-directed DNA methylation. To escape this tight control, retrotransposons employ various strategies to avoid epigenetic silencing. Here we describe the mechanism developed by ONSEN, an LTR-copia type retrotransposon in Arabidopsis thaliana. ONSEN has acquired a heat-responsive element recognized by plant-derived heat stress defense factors, resulting in transcription and production of full length extrachromosomal DNA under elevated temperatures. Further, the ONSEN promoter is free of CG and CHG sites, and the reduction of DNA methylation at the CHH sites is not sufficient to activate the element. Since dividing cells have a more pronounced heat response, the extrachromosomal ONSEN DNA, capable of reintegrating into the genome, accumulates preferentially in the meristematic tissue of the shoot. The recruitment of a major plant heat shock transcription factor in periods of heat stress exploits the plant's heat stress response to achieve the transposon's activation, making it impossible for the host to respond appropriately to stress without losing control over the invader.

  3. Stress Responses to Heat Exposure in Three Species of Australian Desert Birds.

    Science.gov (United States)

    Xie, Shangzhe; Romero, L Michael; Htut, Zaw Win; McWhorter, Todd J

    Birds need to respond to weather changes quickly and appropriately for their own well-being and survival. The inability to respond appropriately to heat waves can be fatal to individual birds and can translate into large-scale mortality events. We investigated corticosterone (CORT) and heterophil∶lymphocyte (H∶L) ratio responses of budgerigars (Melopsittacus undulatus), zebra finches (Taeniopygia guttata), and diamond doves (Geopelia cuneata) to heat exposures. The birds were exposed to a temperature similar to what they experience during a typical summer day (35°C) and a higher temperature (45°C) similar to that experienced during a heat wave. There were no significant increases between the CORT concentrations before and after heat exposure in zebra finches and budgerigars at 35° and 45°C, but there was a significant increase in CORT concentrations in diamond doves after exposure to 45°C. The H∶L ratios increased significantly after heat exposure in budgerigars at 35° and 45°C and in diamond doves at 35°C. No significant correlation was found between the changes in CORT and H∶L ratios. The data suggest that there are species differences in birds' stress responses to heat exposure that may reflect their ability to detect and adapt to high temperatures. There appear to be differences between the two types of stress measurements, which may reflect differences in the timescales of these responses.

  4. Perspectives on deciphering mechanisms underlying plant heat stress response and thermotolerance

    Directory of Open Access Journals (Sweden)

    Kamila Lucia Bokszczanin

    2013-08-01

    Full Text Available Global warming is a major threat for agriculture and food safety and in many cases the negative effects are already apparent. The current challenge of basic and applied plant science is to decipher the molecular mechanisms of heat stress response and thermotolerance in detail and use this information to identify genotypes that will withstand unfavorable environmental conditions. Nowadays X-omics approaches complement the findings of previous targeted studies and highlight the complexity of heat stress response mechanisms giving information for so far unrecognized genes, proteins and metabolites as potential key players of thermotolerance. Even more, roles of epigenetic mechanisms and the involvement of small RNAs in thermotolerance are currently emerging and thus open new directions of yet unexplored areas of plant heat stress response. In parallel it is emerging that although the whole plant is vulnerable to heat, specific organs are particularly sensitive to elevated temperatures. This has redirected research from the vegetative to generative tissues. The sexual reproduction phase is considered as the most sensitive to heat and specifically pollen exhibits the highest sensitivity and frequently an elevation of the temperature just a few degrees above the optimum during pollen development can have detrimental effects for crop production. Compared to our knowledge on heat stress response of vegetative tissues, the information on pollen is still scarce. Nowadays, several techniques for high-throughput X-omics approaches provide major tools to explore the principles of pollen heat stress response and thermotolerance mechanisms in specific genotypes. The collection of such information will provide an excellent support for improvement of breeding programs to facilitate the development of tolerant cultivars. The review aims at describing the current knowledge of thermotolerance mechanisms and the technical advances which will foster new insights into

  5. Modification of the heat response and thermotolerance by cycloheximide, hydroxyurea, and lucanthone in CHO cells

    International Nuclear Information System (INIS)

    Henle, K.J.; Leeper, D.B.

    1982-01-01

    Exposure of Chinese hamster ovary cells to cycloheximide for 2 hr immediately prior to 45 0 C hyperthemia increased cell survival by a factor of 1.8. The increase in cell survival was independent of the heating time for heat treatments longer than 10 min at 45 0 C and was similar with cycloheximide concentrations of 1 and 10 μg/ml. Thermotolerance was induced by an initial treatment of 10 min at 45 0 C (conditioning), developed during a 7-hr incubation period at 37 0 C, and was defined by the hyperthermia dose response with a second 45 0 C heat treatment. When cycloheximide (1μg/ml) was added to the medium after heat conditioning and removed prior to the second heat treatment, the degree of thermotolerance was 50% less than that in medium controls. A 3-hr exposure to 10 μg/ml cycloheximide at 37 0 C by itself did not result in the progressive development of thermotolerance which occurs after a conditioning heat treatment. In contrast to the effects of cycloheximide, hydroxyurea (1 mM) and lucanthone (5 μg/ml) showed little effect on the heat sensitivity and the development of thermotolerance after heat conditioning. Although the results can be interpreted that the development of thermotolerance requires the synthesis of new proteins, but not that of DNA and RNA, alternate interpretations are possible based on known cycloheximide effects aside from its primary inhibition of protein synthesis

  6. Leaf Proteome Analysis Reveals Prospective Drought and Heat Stress Response Mechanisms in Soybean

    Directory of Open Access Journals (Sweden)

    Aayudh Das

    2016-01-01

    Full Text Available Drought and heat are among the major abiotic stresses that affect soybean crops worldwide. During the current investigation, the effect of drought, heat, and drought plus heat stresses was compared in the leaves of two soybean varieties, Surge and Davison, combining 2D-DIGE proteomic data with physiology and biochemical analyses. We demonstrated how 25 differentially expressed photosynthesis-related proteins affect RuBisCO regulation, electron transport, Calvin cycle, and carbon fixation during drought and heat stress. We also observed higher abundance of heat stress-induced EF-Tu protein in Surge. It is possible that EF-Tu might have activated heat tolerance mechanisms in the soybean. Higher level expressions of heat shock-related protein seem to be regulating the heat tolerance mechanisms. This study identifies the differential expression of various abiotic stress-responsive proteins that regulate various molecular processes and signaling cascades. One inevitable outcome from the biochemical and proteomics assays of this study is that increase of ROS levels during drought stress does not show significant changes at the phenotypic level in Davison and this seems to be due to a higher amount of carbonic anhydrase accumulation in the cell which aids the cell to become more resistant to cytotoxic concentrations of H2O2.

  7. Flamingwagon: Athey Wagon braves heat to aid oilpatch blowout response

    Energy Technology Data Exchange (ETDEWEB)

    Leschart, M.

    2002-09-01

    Construction of an Athey wagon by Key Safety Ltd at the company's Red Deer, Alberta facilities is announced. At present, the wagon is awaiting only the installation of its fire-prevention system to be ready for action. The last such blowout response equipment was built in Alberta 40 years ago, and when Crestar Energy lost control of a horizontal sour well during a recent drilling in the Little Bow area, a unit built in 1954 and housed in a museum at the Leduc No. 1 historic site in Devon, Alberta, had to be pressed into service to deal with the emergency. While Athey wagons are not always essential to the blow-out control process, the addition of this new piece of well control safety equipment is welcome news, especially in the light of the new knowledge gained, and innovative processes and procedures developed by Canadian companies fighting oil field fires in Kuwait after the Gulf War.

  8. LOFT fuel module structural response during loss-of-coolant experiments

    International Nuclear Information System (INIS)

    Saffell, B.F. Jr.; Selcho, H.S.

    1979-01-01

    The structural response of the reactor fuel modules installed in the Loss-of-Fluid Test (LOFT) facility have been analyzed for subcooled blowdown loading conditions associated with loss-of-coolant experiments (LOCE). Three independent analyses using the WHAM, SHOCK, and SAP computer codes have been interfaced to calculate the transient mechanical behavior of the LOFT fuel. Test data from two LOCEs indicate the analysis method is conservative. Structural integrity of the fuel modules has been assessed by monitoring guide tube temperatures and control rod drop times during the LOCEs. The analysis and experimental test data indicate the fuel module structural integrity will be maintained for the duration of the LOFT experimental program

  9. Comparison of the superelasticity of different nickel-titanium orthodontic archwires and the loss of their properties by heat treatment.

    Science.gov (United States)

    Bellini, Humberto; Moyano, Javier; Gil, Javier; Puigdollers, Andreu

    2016-10-01

    The aim of this work is to describe and compare mechanical properties of eight widely used nickel-titanium orthodontic wires under uniform testing conditions and to determine the influence of the heat treatments on the loss of the superelasticity. Ten archwires from two batches from eight different manufacturers were evaluated. A three-point bending test was performed, in accordance with ISO 15841:2006, on 80 round nickel-titanium archwire segments of 0.016 inch. To obtain a load-deflection curve, the centre of each segment was deflected to 3.1 mm and then unloaded until force became zero. On the unloading curve, deflection at the end of the plateau and forces delivered at that point, and at 3, 2, 1 and 0.5 mm of deflection, were recorded. Plateau slopes were calculated from 3 and from 2 mm of deflection. Data obtained were statistically analysed to determine inter-brand, intra-brand and inter-batch differences (P Sentalloy M (1.001 N)] was 0.998 N (102 gf). The Nitinol SuperElastic plateau slope (0.353 N/mm) was the only one that was statistically different from 2 mm of deflection, as compared with the other brand values (0.129-0.155 N/mm). Damon Optimal Force described the gentlest slope from 3 mm of deflection (0.230 N/mm) and one of the longest plateaus. Titanol and Orthonol showed the most notable intra-brand differences, whereas inter-batch variability was significant for Nitinol (Henry Schein), Euro Ni-Ti and Orthonol. Superelasticity degree and exerted forces differed significantly among brands. Superelasticity of Nitinol SuperElastic was not observed, while Damon Optimal Force and Proclinic Ni-Ti Superelástico (G&H) showed the most superelastic curves. Intra-brand and inter-batch differences were observed in some brands. In all cases, the heat treatment at 600 °C produces precipitation in the matrix. The precipitates are rich in titanium and this fact produce changes in the chemical composition of the matrix and the loss of

  10. Numerical analysis of the effects of radiation heat transfer and ionization energy loss on the cavitation Bubble's dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Mahdi, M. [Faculty of Mechanical Engineering, K.N. Toosi University of Technology, Tehran (Iran, Islamic Republic of); Ebrahimi, R. [Faculty of Aerospace Engineering, K.N. Toosi University of Technology, Tehran (Iran, Islamic Republic of); Shams, M., E-mail: shams@kntu.ac.ir [Faculty of Mechanical Engineering, K.N. Toosi University of Technology, Pardis St., Molla-Sadra Ave, Vanak. Sq., P.O. Box: 19395-1999, Tehran (Iran, Islamic Republic of)

    2011-06-13

    A numerical scheme for simulating the acoustic and hydrodynamic cavitation was developed. Bubble instantaneous radius was obtained using Gilmore equation which considered the compressibility of the liquid. A uniform temperature was assumed for the inside gas during the collapse. Radiation heat transfer inside the bubble and the heat conduction to the bubble was considered. The numerical code was validated with the experimental data and a good correspondence was observed. The dynamics of hydrofoil cavitation bubble were also investigated. It was concluded that the thermal radiation heat transfer rate strongly depended on the cavitation number, initial bubble radius and hydrofoil angle of attack. -- Highlights: → Heat transfer and ionization energy losses were analyzed in the cavitation bubble. → Radiation of hydrodynamic bubble was approximately equal to the black body. → Radiation heat transfer did not affect the bubble dynamic. → Conduction decreased the bubble pressure and increased the bubble temperature. → Ionization decreased the temperature and increased the pressure in the bubble.

  11. Doppler laser imaging predicts response to topical minoxidil in the treatment of female pattern hair loss.

    Science.gov (United States)

    McCoy, J; Kovacevic, M; Situm, M; Stanimirovic, A; Bolanca, Z; Goren, A

    2016-01-01

    Topical minoxidil is the only drug approved by the US FDA for the treatment of female pattern hair loss. Unfortunately, following 16 weeks of daily application, less than 40% of patients regrow hair. Several studies have demonstrated that sulfotransferase enzyme activity in plucked hair follicles predicts topical minoxidil response in female pattern hair loss patients. However, due to patients’ discomfort with the procedure, and the time required to perform the enzymatic assay it would be ideal to develop a rapid, non-invasive test for sulfotransferase enzyme activity. Minoxidil is a pro-drug converted to its active form, minoxidil sulfate, by sulfotransferase enzymes in the outer root sheath of hair. Minoxidil sulfate is the active form required for both the promotion of hair regrowth and the vasodilatory effects of minoxidil. We thus hypothesized that laser Doppler velocimetry measurement of scalp blood perfusion subsequent to the application of topical minoxidil would correlate with sulfotransferase enzyme activity in plucked hair follicles. In this study, plucked hair follicles from female pattern hair loss patients were analyzed for sulfotransferase enzyme activity. Additionally, laser Doppler velocimetry was used to measure the change in scalp perfusion at 15, 30, 45, and 60 minutes, after the application of minoxidil. In agreement with our hypothesis, we discovered a correlation (r=1.0) between the change in scalp perfusion within 60 minutes after topical minoxidil application and sulfotransferase enzyme activity in plucked hairs. To our knowledge, this is the first study demonstrating the feasibility of using laser Doppler imaging as a rapid, non-invasive diagnostic test to predict topical minoxidil response in the treatment of female pattern hair loss.

  12. Impaired heat shock response in cells expressing full-length polyglutamine-expanded huntingtin.

    Directory of Open Access Journals (Sweden)

    Sidhartha M Chafekar

    Full Text Available The molecular mechanisms by which polyglutamine (polyQ-expanded huntingtin (Htt causes neurodegeneration in Huntington's disease (HD remain unclear. The malfunction of cellular proteostasis has been suggested as central in HD pathogenesis and also as a target of therapeutic interventions for the treatment of HD. We present results that offer a previously unexplored perspective regarding impaired proteostasis in HD. We find that, under non-stress conditions, the proteostatic capacity of cells expressing full length polyQ-expanded Htt is adequate. Yet, under stress conditions, the presence of polyQ-expanded Htt impairs the heat shock response, a key component of cellular proteostasis. This impaired heat shock response results in a reduced capacity to withstand the damage caused by cellular stress. We demonstrate that in cells expressing polyQ-expanded Htt the levels of heat shock transcription factor 1 (HSF1 are reduced, and, as a consequence, these cells have an impaired a heat shock response. Also, we found reduced HSF1 and HSP70 levels in the striata of HD knock-in mice when compared to wild-type mice. Our results suggests that full length, non-aggregated polyQ-expanded Htt blocks the effective induction of the heat shock response under stress conditions and may thus trigger the accumulation of cellular damage during the course of HD pathogenesis.

  13. Transcriptional Profiling and Identification of Heat-Responsive Genes in Perennial Ryegrass by RNA-Sequencing

    Directory of Open Access Journals (Sweden)

    Kehua Wang

    2017-06-01

    Full Text Available Perennial ryegrass (Lolium perenne is one of the most widely used forage and turf grasses in the world due to its desirable agronomic qualities. However, as a cool-season perennial grass species, high temperature is a major factor limiting its performance in warmer and transition regions. In this study, a de novo transcriptome was generated using a cDNA library constructed from perennial ryegrass leaves subjected to short-term heat stress treatment. Then the expression profiling and identification of perennial ryegrass heat response genes by digital gene expression analyses was performed. The goal of this work was to produce expression profiles of high temperature stress responsive genes in perennial ryegrass leaves and further identify the potentially important candidate genes with altered levels of transcript, such as those genes involved in transcriptional regulation, antioxidant responses, plant hormones and signal transduction, and cellular metabolism. The de novo assembly of perennial ryegrass transcriptome in this study obtained more total and annotated unigenes compared to previously published ones. Many DEGs identified were genes that are known to respond to heat stress in plants, including HSFs, HSPs, and antioxidant related genes. In the meanwhile, we also identified four gene candidates mainly involved in C4 carbon fixation, and one TOR gene. Their exact roles in plant heat stress response need to dissect further. This study would be important by providing the gene resources for improving heat stress tolerance in both perennial ryegrass and other cool-season perennial grass plants.

  14. The Transcriptional Heat Shock Response of Salmonella Typhimurium Shows Hysteresis and Heated Cells Show Increased Resistance to Heat and Acid Stress

    DEFF Research Database (Denmark)

    Pin, C.; Hansen, Trine; Munoz-Cuevas, M.

    2012-01-01

    We investigated if the transcriptional response of Salmonella Typhimurium to temperature and acid variations was hysteretic, i.e. whether the transcriptional regulation caused by environmental stimuli showed memory and remained after the stimuli ceased. The transcriptional activity of non......, implying that down-regulation was significantly less synchronized than upregulation. The hysteretic transcriptional response to heat shock was accompanied by higher resistance to inactivation at 50uC as well as cross-resistance to inactivation at pH 3; however, growth rates and lag times at 43uC and at p......H 4.5 were not affected. The exposure to pH 5 only caused up-regulation of 12 genes and this response was neither hysteretic nor accompanied of increased resistance to inactivation conditions. Cellular memory at the transcriptional level may represent a mechanism of adaptation to the environment...

  15. Comparison of the heat shock response induced by conventional heating and two methods of delivery of pulsed radiofrequency energy

    International Nuclear Information System (INIS)

    Laurence, J.A.; University of Sydney, NSW; McKenzie, D.R.; Veas, L.; French, P.W.

    2002-01-01

    Full text: In 2001, we published a (hypothetical) mechanism by which radiofrequency (RF) radiation from mobile phones could induce cancer, via the chronic induction of the heat shock response (HSR). This hypothesis provides the focus for our research. Other groups have reported induction of the HSR by RF at apparently non thermal levels. The aim of this study was to determine whether the HSR induced by RF is (a) truly non thermal and (b) quantitatively or qualitatively different from that induced by conventional heating of cells. A rat mast cell line, RBL-2H3, was chosen as the target RBL-2H3 cells were exposed in an air incubator at 41.1 deg C for 45 minutes and 75 minutes, and then returned to a 37 deg C incubator. Sham exposures were performed in the same air incubator at 37 deg C. Cells were exposed for 1 hour in the two pulsed RF exposure systems. The first was a converted 750W microwave oven that emits a short burst of 2.45GHz pulses at the start of each contiguous six minute period. This exposes cells to an average specific energy absorption rate (SAR) of 20W/kg. The second system was a TEM cell, which simulates. GSM pulses - the earner frequency is 0.9GHz pulse modulated at 217Hz. The SAR was approx 0.1W/kg. Both of these exposure systems are housed in incubators maintained at 37 deg C. Sham exposures were performed in the two systems with the same conditions but with no RF radiation present. Cell samples for the conventional heating and microwave exposures were taken 0, 2. 5, 5 and 20 hours after exposure, and expression of heat shock proteins hsp 110, 90, 70, 60 and 56 were determined by Western Blotting and compared between exposures

  16. Physiological Responses and Physical Performance during Football in the Heat

    Science.gov (United States)

    Mohr, Magni; Nybo, Lars; Grantham, Justin; Racinais, Sebastien

    2012-01-01

    Purpose To examine the impact of hot ambient conditions on physical performance and physiological responses during football match-play. Methods Two experimental games were completed in temperate (∼21°C; CON) and hot ambient conditions (∼43°C; HOT). Physical performance was assessed by match analysis in 17 male elite players during the games and a repeated sprint test was conducted after the two game trials. Core and muscle temperature were measured and blood samples were obtained, before and after the games. Results Muscle and core temperatures were ∼1°C higher (P14 km⋅h−1) by 26% in HOT compared to CON), but peak sprint speed was 4% higher (P24 km⋅h−1) between CON and HOT. In HOT, success rates for passes and crosses were 8 and 9% higher (Pheat (r = 0.85 and r = 0.53, respectively; Pheat, but these changes were not directly related to the absolute or relative changes in core or muscle temperature. However, peak sprinting speed and execution of successful passes and crosses were improved in the HOT condition. PMID:22723963

  17. Maximum Expected Wall Heat Flux and Maximum Pressure After Sudden Loss of Vacuum Insulation on the Stratospheric Observatory for Infrared Astronomy (SOFIA) Liquid Helium (LHe) Dewars

    Science.gov (United States)

    Ungar, Eugene K.

    2014-01-01

    The aircraft-based Stratospheric Observatory for Infrared Astronomy (SOFIA) is a platform for multiple infrared observation experiments. The experiments carry sensors cooled to liquid helium (LHe) temperatures. A question arose regarding the heat input and peak pressure that would result from a sudden loss of the dewar vacuum insulation. Owing to concerns about the adequacy of dewar pressure relief in the event of a sudden loss of the dewar vacuum insulation, the SOFIA Program engaged the NASA Engineering and Safety Center (NESC). This report summarizes and assesses the experiments that have been performed to measure the heat flux into LHe dewars following a sudden vacuum insulation failure, describes the physical limits of heat input to the dewar, and provides an NESC recommendation for the wall heat flux that should be used to assess the sudden loss of vacuum insulation case. This report also assesses the methodology used by the SOFIA Program to predict the maximum pressure that would occur following a loss of vacuum event.

  18. Modeling of flows in heat exchangers with distributed load loss. Simulation of wet-type cooling tower operation with the two-dimensional calculation code ETHER

    International Nuclear Information System (INIS)

    Coic, P.

    1984-01-01

    The principle of a cooling tower is first presented. The equations of the problem are given; the modeling of load losses and heat transfer is described. Then, the numerical method based on a finite difference discrete method is described. Finally, the different results of the calculations carried out in the case of an industrial operation are presented [fr

  19. Impact of Subgrid Scale Models and Heat Loss on Large Eddy Simulations of a Premixed Jet Burner Using Flamelet-Generated Manifolds

    Science.gov (United States)

    Hernandez Perez, Francisco E.; Im, Hong G.; Lee, Bok Jik; Fancello, Alessio; Donini, Andrea; van Oijen, Jeroen A.; de Goey, L. Philip H.

    2017-11-01

    Large eddy simulations (LES) of a turbulent premixed jet flame in a confined chamber are performed employing the flamelet-generated manifold (FGM) method for tabulation of chemical kinetics and thermochemical properties, as well as the OpenFOAM framework for computational fluid dynamics. The burner has been experimentally studied by Lammel et al. (2011) and features an off-center nozzle, feeding a preheated lean methane-air mixture with an equivalence ratio of 0.71 and mean velocity of 90 m/s, at 573 K and atmospheric pressure. Conductive heat loss is accounted for in the FGM tabulation via burner-stabilized flamelets and the subgrid-scale (SGS) turbulence-chemistry interaction is modeled via presumed filtered density functions. The impact of heat loss inclusion as well as SGS modeling for both the SGS stresses and SGS variance of progress variable on the numerical results is investigated. Comparisons of the LES results against measurements show a significant improvement in the prediction of temperature when heat losses are incorporated into FGM. While further enhancements in the LES results are accomplished by using SGS models based on transported quantities and/or dynamically computed coefficients as compared to the Smagorinsky model, heat loss inclusion is more relevant. This research was sponsored by King Abdullah University of Science and Technology (KAUST) and made use of computational resources at KAUST Supercomputing Laboratory.

  20. NOy production, ozone loss and changes in net radiative heating due to energetic particle precipitation in 2002–2010

    Directory of Open Access Journals (Sweden)

    M. Sinnhuber

    2018-01-01

    the models in nearly every polar winter, ranging from 10–50 % during solar maximum to 2–10 % during solar minimum. Ozone loss continues throughout polar summer after strong solar proton events in the Southern Hemisphere and after large sudden stratospheric warmings in the Northern Hemisphere. During mid-winter, the ozone loss causes a reduction of the infrared radiative cooling, i.e., a positive change of the net radiative heating (effective warming, in agreement with analyses of geomagnetic forcing in stratospheric temperatures which show a warming in the late winter upper stratosphere. In late winter and spring, the sign of the net radiative heating change turns to negative (effective cooling. This spring-time cooling lasts well into summer and continues until the following autumn after large solar proton events in the Southern Hemisphere, and after sudden stratospheric warmings in the Northern Hemisphere.

  1. Physiological responses of horses to a treadmill simulated speed and endurance test in high heat and humidity before and after humid heat acclimation.

    Science.gov (United States)

    Marlin, D J; Scott, C M; Schroter, R C; Harris, R C; Harris, P A; Roberts, C A; Mills, P C

    1999-01-01

    To investigate whether horses were able to acclimate to conditions of high temperature and humidity, 5 horses of different breeds were trained for 80 min on 15 consecutive days on a treadmill at 30 degrees C and 80%RH. Training consisted of a combination of long duration low-intensity exercise, medium duration medium intensity exercise and short duration high intensity exercise. Between training sessions the horses were maintained at 11+/-3 degrees C and 74+/-2%RH. Before (PRE-ACC) and after acclimation (POST-ACC) the horses undertook a simulated Competition Exercise Test (CET), designed to represent the Speed and Endurance Test of a 3-day event, at 30 degrees C/80%RH. Maximal oxygen uptake (VO2PEAK) was not changed following acclimation (PRE-ACC 141+/-8 ml/min/kg bwt vs. POST-ACC 145+/-9 ml/min/kg bwt [STPD], P>0.05). Following acclimation, 4 of the 5 horses were able to complete a significantly greater amount of Phase D in the CET (PRE-ACC 6.3+/-0.3 min vs. POST-ACC 7.3+/-0.3 min, P<0.05; target time = 8 min). Resting body temperatures (pulmonary artery [TPA], rectal [TREC] and tail-skin [TTSK] temperatures) were all significantly lower following acclimation. During exercise, metabolic heat production (M) and heat dissipation (HD), for the same exercise duration, were both significantly lower following acclimation (P<0.05), although heat storage (HS) was significantly higher (P<0.05). The higher heat storage following acclimation was associated with a lower TTSK for a given TPA and a decreased total fluid loss (% bodyweight, P<0.05). Plasma volume was not changed following acclimation. The relationship of sweating rate (SR) to TPA or TTSK on either the neck or the gluteal region was not significantly altered by acclimation, although the onset of sweating occurred at a lower TPA or TTSK following acclimation (P<0.05). The horses in the present study showed a number of physiological adaptations to a period of 15 days of exposure to high heat and humidity consistent

  2. Prediction of postoperative pain by preoperative pain response to heat stimulation in total knee arthroplasty.

    Science.gov (United States)

    Lunn, Troels H; Gaarn-Larsen, Lissi; Kehlet, Henrik

    2013-09-01

    It has been estimated that up to 54% of the variance in postoperative pain experience may be predicted with preoperative pain responses to experimental stimuli, with suprathreshold heat pain as the most consistent test modality. This study aimed to explore whether 2 heat test paradigms could predict postoperative pain after total knee arthroplasty (TKA). Patients scheduled for elective, unilateral, primary TKA under spinal anesthesia were consecutively included in this prospective, observational study. Perioperative analgesia was standardized for all patients. Outcomes were postoperative pain during walk: from 6 to 24 hours (primary), from postoperative day (POD) 1 to 7 (secondary), and from POD 14 to 30 (tertiary). Two preoperative tonic heat stimuli with 47°C were used; short (5 seconds) and long (7 minutes) stimulation upon which patients rated their pain response on an electronic visual analog scale. Multivariate stepwise linear and logistic regressions analyses were carried out, including 8 potential preoperative explanatory variables (among these anxiety, depression, preoperative pain, and pain catastrophizing) to assess pain response to preoperative heat pain stimulation as an independent predictor for postoperative pain. A total of 100 patients were included, and 3 were later excluded. A weak correlation [rho (95% confidence interval); P value] was observed between pain from POD 1 to 7 and pain response to short [rho=0.25(0.04 to 0.44); P=.02] and to long [rho=0.27 (0.07 to 0.46); P=.01] heat pain stimulation. However, these positive correlations were not supported by the linear and logistic regression analyses, in which only anxiety, preoperative pain, and pain catastrophizing were significant explanatory variables (but with low R-squares; 0.05 to 0.08). Pain responses to 2 types of preoperative heat stimuli were not independent clinically relevant predictors for postoperative pain after TKA. Copyright © 2013 International Association for the Study of

  3. Density response to central electron heating: theoretical investigations and experimental observations in ASDEX Upgrade

    Science.gov (United States)

    Angioni, C.; Peeters, A. G.; Garbet, X.; Manini, A.; Ryter, F.; ASDEX Upgrade Team

    2004-08-01

    Theory of ion temperature gradient (ITG) and trapped electron modes (TEMs) is applied to the study of particle transport in experimental conditions with central electron heating. It is shown that in the unstable domain of TEMs, the electron thermodiffusive flux is directed outwards. By means of such a flux, a mechanism is identified likely to account for density flattening with central electron heating. Theoretical predictions are compared with experimental observations in ASDEX Upgrade. A parameter domain (including L- and H-mode plasmas) is identified, in which flattening with central electron heating is observed in the experiments. In general, this domain turns out to be the same domain in which the dominant plasma instability is a TEM. On the contrary, the dominant instability is an ITG in plasmas whose density profile is not affected significantly by central electron heating. The flattening predicted by quasi-linear theory for low density L-mode plasmas is too small compared to the experimental observations. At very high density, even when the dominant instability is an ITG, electron heating can provide density flattening, via the coupling with the ion heat channel. In these conditions the anomalous diffusivity increases in response to the increased ion heat flux, while the large collisionality makes the anomalous pinch small and the Ware pinch important.

  4. Simulation of the ATLAS SCT barrel module response to LHC beam loss scenarios

    CERN Document Server

    Rose, P; The ATLAS collaboration; Fadeyev, V; Spencer, E; Wilder, M; Domingo, M

    2014-01-01

    In the event of beam loss at the LHC, ATLAS Inner Detector components nearest the beam line may be subjected to unusually large amounts of radiation. Understanding their behavior in such an event is important in determining whether they would still function properly. We built a SPICE model of the silicon strip module electrical system to determine the behavior of its elements during a realistic beam loss scenario. We found that the power supply and bias filter characteristics strongly affect the module response in such scenarios. In particular, the following self-limiting phenomena were observed: there is a finite amount of charge initially available on the bias filter capacitors for collection by the strips; the power supply current limit reduces the rate at which the bias filter capacitors' charge can be replenished; the reduced bias voltage leads to a smaller depletion depth in the sensors which results in less collected charge. These effects provide a larger measure of safety during beam loss events than ...

  5. Simulation of the ATLAS SCT Barrel Module Response to LHC Beam Loss Scenarios

    CERN Document Server

    Rose, P; The ATLAS collaboration; Fadeyev, V; Spencer, E; Wilder, M; Domingo, M

    2013-01-01

    In the event of beam loss at the LHC, ATLAS Inner Detector components nearest the beamline may be subjected to unusually large amounts of radiation. Understanding their behavior in such an event is important in determining whether they would still function properly. We built a SPICE model of the silicon strip module electrical system to determine the behavior of its elements during a realistic beam loss scenario. We found that the power supply and bias filter characteristics strongly affect the module response in such scenarios. In particular, the following self-limiting phenomena were observed: there is a finite amount of charge initially available on the bias filter capacitors for collection by the strips; the power supply current limit reduces the rate at which the bias filter capacitors' charge can be replenished; the reduced bias voltage leads to a smaller depletion depth which results in less collected charge. These effects provide a larger measure of safety during beam loss events than we have previous...

  6. Decreased hedonic responsiveness following chronic mild stress is not secondary to loss of body weight.

    Science.gov (United States)

    Willner, P; Moreau, J L; Nielsen, C K; Papp, M; Sluzewska, A

    1996-07-01

    Chronic exposure to mild unpredictable stress (CMS) has previously been found to decrease hedonic responsiveness, as measured by the consumption of palatable sweet solutions or sensitivity to brain stimulation reward. These effects are reversed by chronic treatment with antidepressant drugs, and the CMS procedure has been proposed as a relatively valid animal model of depression. It has recently been suggested that the behavioural effects of CMS may be secondary to loss of body weight. This article collates data from five laboratories using the CMS procedure. Data are presented from seven studies using five different rat strains, as well as CD1 mice. Three-week exposure to CMS significantly decreased sucrose consumption by Lister hooded, PVG hooded, Wistar, and Wistar WU rats, and by CD1 mice, and sensitivity to brain stimulation reward in Ibm:Ro Ro rats. Weight loss in different experiments varied between 0 and 10%. Hedonic sensitivity relative to body weight (e.g., mg sucrose/g body weight) decreased significantly in all experiments. Animals maintained on a restricted feeding regime lost weight but did not show decreases in sucrose intake. It is concluded that decreased hedonic sensitivity following chronic mild stress cannot be attributed to loss of body weight.

  7. Small mammal diversity loss in response to late-Pleistocene climatic change.

    Science.gov (United States)

    Blois, Jessica L; McGuire, Jenny L; Hadly, Elizabeth A

    2010-06-10

    Communities have been shaped in numerous ways by past climatic change; this process continues today. At the end of the Pleistocene epoch about 11,700 years ago, North American communities were substantially altered by the interplay of two events. The climate shifted from the cold, arid Last Glacial Maximum to the warm, mesic Holocene interglacial, causing many mammal species to shift their geographic distributions substantially. Populations were further stressed as humans arrived on the continent. The resulting megafaunal extinction event, in which 70 of the roughly 220 largest mammals in North America (32%) became extinct, has received much attention. However, responses of small mammals to events at the end of the Pleistocene have been much less studied, despite the sensitivity of these animals to current and future environmental change. Here we examine community changes in small mammals in northern California during the last 'natural' global warming event at the Pleistocene-Holocene transition and show that even though no small mammals in the local community became extinct, species losses and gains, combined with changes in abundance, caused declines in both the evenness and richness of communities. Modern mammalian communities are thus depauperate not only as a result of megafaunal extinctions at the end of the Pleistocene but also because of diversity loss among small mammals. Our results suggest that across future landscapes there will be some unanticipated effects of global change on diversity: restructuring of small mammal communities, significant loss of richness, and perhaps the rising dominance of native 'weedy' species.

  8. Natural Circulation in the Blanket Heat Removal System During a Loss-of-Pumping Accident (LOFA) Based on Initial Conceptual Design

    International Nuclear Information System (INIS)

    Hamm, L.L.

    1998-01-01

    A transient natural convection model of the APT blanket primary heat removal (HR) system was developed to demonstrate that the blanket could be cooled for a sufficient period of time for long term cooling to be established following a loss-of-flow accident (LOFA). The particular case of interest in this report is a complete loss-of-pumping accident. For the accident scenario in which pumps are lost in both the target and blanket HR systems, natural convection provides effective cooling of the blanket for approximately 68 hours, and, if only the blanket HR systems are involved, natural convection is effective for approximately 210 hours. The heat sink for both of these accident scenarios is the assumed stagnant fluid and metal on the secondary sides of the heat exchangers

  9. Response of concrete exposed to a high heat flux on one surface

    International Nuclear Information System (INIS)

    Muir, J.F.

    1977-11-01

    Experiments were performed to investigate the response of concrete to severe thermal environments such as might be encountered during the interaction of molten reactor core materials with the containment substructure following a hypothetical fuel melt accident. The dominant mechanism for erosion of both limestone and basaltic concrete appears to be melting of the cementitious material in the matrix. The erosion proceeded in a quiescent manner with negligible spallation. The erosion rate increased with heat flux, becoming as large as approximately 70 cm/hr for a net surface heat flux of roughly 190 W/cm 2 . Analyses reveal the surface temperature to be the single most significant parameter affecting the net surface heat flux, through its importance to emitted radiation; and that the greatest fraction of the net energy transmitted to the concrete goes into sensible heat

  10. Numerical analysis of thermal response tests with a groundwater flow and heat transfer model

    Energy Technology Data Exchange (ETDEWEB)

    Raymond, J.; Therrien, R. [Departement de Geologie et de Genie Ggeologique, Universite Laval, 1065 avenue de la medecine, Quebec (Qc) G1V 0A6 (Canada); Gosselin, L. [Departement de Genie Mecanique, Universite Laval, 1065 avenue de la medecine, Quebec (Qc) G1V 0A6 (Canada); Lefebvre, R. [Institut National de la Recherche Scientifique, Centre Eau Terre Environnement, 490 de la Couronne, Quebec (Qc) G1K 9A9 (Canada)

    2011-01-15

    The Kelvin line-source equation, used to analyze thermal response tests, describes conductive heat transfer in a homogeneous medium with a constant temperature at infinite boundaries. The equation is based on assumptions that are valid for most ground-coupled heat pump environments with the exception of geological settings where there is significant groundwater flow, heterogeneous distribution of subsurface properties, a high geothermal gradient or significant atmospheric temperature variations. To address these specific cases, an alternative method to analyze thermal response tests was developed. The method consists in estimating parameters by reproducing the output temperature signal recorded during a test with a numerical groundwater flow and heat transfer model. The input temperature signal is specified at the entrance of the ground heat exchanger, where flow and heat transfer are computed in 2D planes representing piping and whose contributions are added to the 3D porous medium. Results obtained with this method are compared to those of the line-source model for a test performed under standard conditions. A second test conducted in waste rock at the South Dump of the Doyon Mine, where conditions deviate from the line-source assumptions, is analyzed with the numerical model. The numerical model improves the representation of the physical processes involved during a thermal response test compared to the line-source equation, without a significant increase in computational time. (author)

  11. Arctigenin from Fructus Arctii is a novel suppressor of heat shock response in mammalian cells

    Science.gov (United States)

    Ishihara, Keiichi; Yamagishi, Nobuyuki; Saito, Youhei; Takasaki, Midori; Konoshima, Takao; Hatayama, Takumi

    2006-01-01

    Because heat shock proteins (Hsps) are involved in protecting cells and in the pathophysiology of diseases such as inflammation, cancer, and neurodegenerative disorders, the use of regulators of the expression of Hsps in mammalian cells seems to be useful as a potential therapeutic modality. To identify compounds that modulate the response to heat shock, we analyzed several natural products using a mammalian cell line containing an hsp promoter-regulated reporter gene. In this study, we found that an extract from Fructus Arctii markedly suppressed the expression of Hsp induced by heat shock. A component of the extract arctigenin, but not the component arctiin, suppressed the response at the level of the activation of heat shock transcription factor, the induction of mRNA, and the synthesis and accumulation of Hsp. Furthermore, arctigenin inhibited the acquisition of thermotolerance in mammalian cells, including cancer cells. Thus, arctigenin seemed to be a new suppressive regulator of heat shock response in mammalian cells, and may be useful for hyperthermia cancer therapy. PMID:16817321

  12. Comparative transcriptional analysis of clinically relevant heat stress response in Clostridium difficile strain 630.

    Directory of Open Access Journals (Sweden)

    Nigel G Ternan

    Full Text Available Clostridium difficile is considered to be one of the most important causes of health care-associated infections worldwide. In order to understand more fully the adaptive response of the organism to stressful conditions, we examined transcriptional changes resulting from a clinically relevant heat stress (41 °C versus 37 °C in C. difficile strain 630 and identified 341 differentially expressed genes encompassing multiple cellular functional categories. While the transcriptome was relatively resilient to the applied heat stress, we noted upregulation of classical heat shock genes including the groEL and dnaK operons in addition to other stress-responsive genes. Interestingly, the flagellin gene (fliC was downregulated, yet genes encoding the cell-wall associated flagellar components were upregulated suggesting that while motility may be reduced, adherence--to mucus or epithelial cells--could be enhanced during infection. We also observed that a number of phage associated genes were downregulated, as were genes associated with the conjugative transposon Tn5397 including a group II intron, thus highlighting a potential decrease in retromobility during heat stress. These data suggest that maintenance of lysogeny and genome wide stabilisation of mobile elements could be a global response to heat stress in this pathogen.

  13. NLP modeling for the optimization of LiBr-H_2O absorption refrigeration systems with exergy loss rate, heat transfer area, and cost as single objective functions

    International Nuclear Information System (INIS)

    Mussati, Sergio F.; Gernaey, Krist V.; Morosuk, Tatiana; Mussati, Miguel C.

    2016-01-01

    Highlights: • A NLP model is used for simultaneous optimization of sizes and operating conditions. • Total exergy loss rate and transfer area are optimized as single objective functions. • Theoretical and practical bounds for cost optimization problems are computed. • A systematic solution strategy is proposed for total annual cost optimization. • Relevance of components is ranked by heat transfer area, exergy loss rate, and cost. - Abstract: Based on a nonlinear mathematical programming model, the sizes and operating conditions of the process units of single-effect absorption refrigeration systems operating with a LiBr–H_2O solution are optimized for a specified cooling capacity by minimizing three single objective functions: the total exergy loss rate, the total heat transfer area, and the total annual cost of the system. It was found that the optimal solution obtained by minimization of the total exergy loss rate provides “theoretical” upper bounds not only for the total heat transfer area of the system but also for each process unit and all stream temperatures, while the optimal solution obtained by minimization of the total heat transfer area provides the lower bounds for these model variables, to solve a cost optimization problem. The minimization of the total exergy loss rate by varying parametrically the available total heat transfer area between these bounds was also performed, allowing to see how the optimal distribution of the available total heat transfer area among the system components, as well as the operating conditions (stream temperature, pressure, composition, and mass flow rate) and heat loads, vary qualitatively and quantitatively with increasing available total heat transfer area. These optimization results allowed to find a “practical” value of the total heat transfer area, i.e. no benefits can be obtained by increasing the available total heat transfer area above this value since the minimal total exergy loss value cannot

  14. Loss of melanocortin-4 receptor function attenuates HPA responses to psychological stress

    DEFF Research Database (Denmark)

    Ryan, Karen K; Mul, Joram D; Clemmensen, Christoffer

    2014-01-01

    function. These results support the hypothesis that endogenous MC4R signaling contributes to the HPA axis response to stress. Because MC4R plays a critical role in the regulation of energy balance, the present work suggests that it may also serve as an important communication link between brain metabolic...... in hypothalamic-pituitary-adrenocortical axis (HPA) regulation. The present work investigated the role of chronic Mc4r function to modulate basal HPA axis tone and to facilitate acute HPA responses to psychological stress, using a novel rat model with Mc4r loss-of-function. In this study, adult male rats were......The melanocortin 4 receptor (MC4R), well-known for its role in the regulation of energy balance, is widely expressed in stress-regulatory brain regions, including the paraventricular nucleus of the hypothalamus (PVH) and the medial amygdala (MeA). In agreement with this, MC4R has been implicated...

  15. Melanocortin-3 receptors in the limbic system mediate feeding-related motivational responses during weight loss

    Directory of Open Access Journals (Sweden)

    Maria Mavrikaki

    2016-07-01

    Full Text Available Objective: Appetitive responses to weight loss are mediated by a nutrient-sensing neural network comprised of melanocortin neurons. The role of neural melanocortin-3 receptors (MC3R in mediating these responses is enigmatic. Mc3r knockout mice exhibit a paradoxical phenotype of obesity and reduced feeding-related behaviors in situations of nutrient scarcity. Here we examined whether MC3Rs expressed in mesolimbic neurons regulate feeding-related motivational responses. Methods: Interactions between Mc3r genotype, cognitive function and energy balance on food self-administration were assessed using operant conditioning with fixed- and progressive ratio (FR1/PR1 settings. Inhibition of Mc3r transcription by a loxP-flanked transcriptional blocker (TB in C57BL/6JN mice (Mc3rTB/TB was reversed in mesolimbic neurons using DAT-Cre (DAT-MC3R. Results: Caloric restriction (CR caused 10–15% weight loss and increased motivation to acquire food rewards during training sessions. c-Fos-expression in the nucleus accumbens was increased 1 h following food presentation. While exhibiting weight loss, total food self-administration, enhanced motivation to self-administer food rewards in training sessions held during CR and c-Fos-activation in the nucleus accumbens following re-feeding were all markedly attenuated in Mc3rTB/TB mice. In contrast, cognitive abilities were normal in Mc3rTB/TB mice. Total food self-administration during FR1 sessions was not rescued in DAT-MC3R mice, however enhanced motivational responses to self-administer food rewards in PR1 conditions were restored. The nutrient-partitioning phenotype observed with Mc3r-deficiency was not rescued in DAT-MC3R mice. Conclusions: Mesolimbic MC3Rs mediate enhanced motivational responses during CR. However, they are insufficient to restore normal caloric loading when food is presented during CR and do not affect metabolic conditions altering nutrient partitioning. Author Video: Author Video Watch what

  16. The Response of the Ocean Thermal Skin Layer to Air-Sea Surface Heat Fluxes

    Science.gov (United States)

    Wong, Elizabeth Wing-See

    There is much evidence that the ocean is heating as a result of an increase in concentrations of greenhouse gases (GHGs) in the atmosphere from human activities. GHGs absorb infrared radiation and re-emit infrared radiation back to the ocean's surface which is subsequently absorbed. However, the incoming infrared radiation is absorbed within the top micrometers of the ocean's surface which is where the thermal skin layer exists. Thus the incident infrared radiation does not directly heat the upper few meters of the ocean. We are therefore motivated to investigate the physical mechanism between the absorption of infrared radiation and its effect on heat transfer at the air-sea boundary. The hypothesis is that since heat lost through the air-sea interface is controlled by the thermal skin layer, which is directly influenced by the absorption and emission of infrared radiation, the heat flow through the thermal skin layer adjusts to maintain the surface heat loss, assuming the surface heat loss does not vary, and thus modulates the upper ocean heat content. This hypothesis is investigated through utilizing clouds to represent an increase in incoming longwave radiation and analyzing retrieved thermal skin layer vertical temperature profiles from a shipboard infrared spectrometer from two research cruises. The data are limited to night-time, no precipitation and low winds of less than 2 m/s to remove effects of solar radiation, wind-driven shear and possibilities of thermal skin layer disruption. The results show independence of the turbulent fluxes and emitted radiation on the incident radiative fluxes which rules out the immediate release of heat from the absorption of the cloud infrared irradiance back into the atmosphere through processes such as evaporation and increase infrared emission. Furthermore, independence was confirmed between the incoming and outgoing radiative flux which implies the heat sink for upward flowing heat at the air-sea interface is more

  17. Reduction of heat losses on the skid pipe system of a pusher type furnace; Verringerung der Waermeverluste am Tragrohrsystem eines Stossofens

    Energy Technology Data Exchange (ETDEWEB)

    Hoffelner, Mario; Winter, Franz [voestalpine Grobblech GmbH, Linz (Austria); Springer, Michael; Huegel, Frank [FBB Engineering GmbH, Moenchengladbach (Germany); Buhr, Andreas [Almatis GmbH, Frankfurt (Germany); Kockegey-Lorenz, Rainer [Almatis GmbH, Ludwigshafen (Germany)

    2013-06-15

    This paper discusses how energy consumption and energy loss can be reduced in reheating furnaces of hot rolling mills by new lightweight refractory materials and a new modular lining concept for the skid pipe insulation using pre-fabricated shells. The target is to optimise the hot rolling process from an energy point of view, and to reduce the operational cost of the furnaces. The new lightweight pre-fabricated shells based on the microporous castable and a thermotechnical optimised sandwich design can significantly reduce the heat losses compared to dense castable. Industrial application of the new system in a 110 t/h pusher type furnace at voestalpine Grobblech GmbH in Linz, Austria, resulted in reduction of heat loss about 30 %. The annualised energy saving gives a cost reduction of more than Euro 200,000 a year. Costs for the complete new lining about Euro 170,000 result in a payback period of less than one year. (orig.)

  18. Myocardial functional responses do not contribute to maximal exercise performance in the heat.

    Science.gov (United States)

    Smith, Denise L; DeBlois, Jacob P; Wharton, Margaret; Rowland, Thomas

    2015-01-01

    Both the extent and means by which maximal oxygen uptake ([Formula: see text]) is depressed by elevated ambient temperature are uncertain. Particularly, information is currently unavailable regarding the possible influence of alterations in myocardial function on [Formula: see text] and performance during exercise in the heat. This study investigated the effects of environmental heat on [Formula: see text], peak work capacity, and myocardial function during a standard, progressive cycle test to exhaustion. Twelve euhydrated men (aged 20.7 ± 1.7 years) performed a maximal cycle test in an environmental chamber in both heat stress [35°C, 30% relative humidity (RH)] and temperate (20°C, 30% RH) conditions with measurement of standard gas exchange variables, core temperature, and echocardiographic measures of cardiac function. A small but statistically significant reduction of peak work capacity was observed in the heat stress versus temperate conditions (253 ± 30 and 259 ± 30 W, respectively, p = 0.02). Mean [Formula: see text] was not statistically different in the two conditions (p = 0.16) but values were 3.4% lower in the heat, and 9 of 12 participants demonstrated lower values in the heat stress trial. No differences in responses of heart rate, cardiac output, stroke volume, core temperature, hydration status, or myocardial systolic or diastolic function were observed between the two conditions, but perceived body temperature was higher in the heat. The small, negative impact of heat on exercise performance and [Formula: see text] could not be explained by disturbances in myocardial functional responses to exercise in young adult males.

  19. Theoretical Loss and Gambling Intensity (Revisited): A Response to Braverman et al. (2013).

    Science.gov (United States)

    Auer, Michael; Griffiths, Mark D

    2015-09-01

    In this paper, we provide a brief response to Braverman et al. (J Gambl Stud. doi: 10.1007/s10899-013-9428-z , 2013b) critique of our 'Theoretical Loss' metric as a measure of monetary gambling intensity (Auer and Griffiths in J Gambl Stud. doi: 10.1007/s10899-013-9376-7 , 2013a; Auer et al. in Gaming Law Rev Econ 16:269-273, 2012). We argue that 'gambling intensity' and 'gambling involvement' are essentially the same construct as descriptors of monetary gambling activity. Additionally, we acknowledge that playing duration (i.e., the amount of time—as opposed to money—actually spent gambling) is clearly another important indicator of gambling involvement-something that we have consistently noted in our previous studies including our empirical studies on gambling using behavioural tracking data. Braverman and colleagues claim that the concept of Theoretical Loss is nullified when statistical analysis focuses solely on one game type as the house edge is constant across all games. In fact, they state, the correlation between total amount wagered and Theoretical Loss is perfect. Unfortunately, this is incorrect. To disprove the claim made, we demonstrate that in sports betting (i.e., a single game type), the amount wagered does not reflect monetary gambling involvement using actual payout percentage data (based on 52,500 independent bets provided to us by an online European bookmaker). After reviewing the arguments presented by Braverman and colleagues, we are still of the view that when it comes to purely monetary measures of 'gambling intensity', the Theoretical Loss metric is a more robust and accurate measure than other financial proxy measures such as 'amount wagered' (i.e., bet size) as a measure of what players are prepared to financially risk while gambling.

  20. Thermotolerant yeasts selected by adaptive evolution express heat stress response at 30ºC

    DEFF Research Database (Denmark)

    Caspeta, Luis; Chen, Yun; Nielsen, Jens

    2016-01-01

    to grow at increased temperature, activated a constitutive heat stress response when grown at the optimal ancestral temperature, and that this is associated with a reduced growth rate. This preventive response was perfected by additional transcriptional changes activated when the cultivation temperature...... is increased. Remarkably, the sum of global transcriptional changes activated in the thermotolerant strains when transferred from the optimal to the high temperature, corresponded, in magnitude and direction, to the global changes observed in the ancestral strain exposed to the same transition....... This demonstrates robustness of the yeast transcriptional program when exposed to heat, and that the thermotolerant strains streamlined their path to rapidly and optimally reach post-stress transcriptional and metabolic levels. Thus, long-term adaptation to heat improved yeasts ability to rapidly adapt to increased...

  1. Vibration-response due to thickness loss on steel plate excited by resonance frequency

    Science.gov (United States)

    Kudus, S. A.; Suzuki, Y.; Matsumura, M.; Sugiura, K.

    2018-04-01

    The degradation of steel structure due to corrosion is a common problem found especially in the marine structure due to exposure to the harsh marine environment. In order to ensure safety and reliability of marine structure, the damage assessment is an indispensable prerequisite for plan of remedial action on damaged structure. The main goal of this paper is to discuss simple vibration measurement on plated structure to give image on overview condition of the monitored structure. The changes of vibration response when damage was introduced in the plate structure were investigated. The damage on plate was simulated in finite element method as loss of thickness section. The size of damage and depth of loss of thickness were varied for different damage cases. The plate was excited with lower order of resonance frequency in accordance estimate the average remaining thickness based on displacement response obtain in the dynamic analysis. Significant reduction of natural frequency and increasing amplitude of vibration can be observed in the presence of severe damage. The vibration analysis summarized in this study can serve as benchmark and reference for researcher and design engineer.

  2. Intraspecific variation in cellular and biochemical heat response strategies of Mediterranean Xeropicta derbentina [Pulmonata, Hygromiidae].

    Directory of Open Access Journals (Sweden)

    Sandra Troschinski

    Full Text Available Dry and hot environments challenge the survival of terrestrial snails. To minimize overheating and desiccation, physiological and biochemical adaptations are of high importance for these animals. In the present study, seven populations of the Mediterranean land snail species Xeropicta derbentina were sampled from their natural habitat in order to investigate the intraspecific variation of cellular and biochemical mechanisms, which are assigned to contribute to heat resistance. Furthermore, we tested whether genetic parameters are correlated with these physiological heat stress response patterns. Specimens of each population were individually exposed to elevated temperatures (25 to 52°C for 8 h in the laboratory. After exposure, the health condition of the snails' hepatopancreas was examined by means of qualitative description and semi-quantitative assessment of histopathological effects. In addition, the heat-shock protein 70 level (Hsp70 was determined. Generally, calcium cells of the hepatopancreas were more heat resistant than digestive cells - this phenomenon was associated with elevated Hsp70 levels at 40°C.We observed considerable variation in the snails' heat response strategy: Individuals from three populations invested much energy in producing a highly elevated Hsp70 level, whereas three other populations invested energy in moderate stress protein levels - both strategies were in association with cellular functionality. Furthermore, one population kept cellular condition stable despite a low Hsp70 level until 40°C exposure, whereas prominent cellular reactions were observed above this thermal limit. Genetic diversity (mitochondrial cytochrome c oxidase subunit I gene within populations was low. Nevertheless, when using genetic indices as explanatory variables in a multivariate regression tree (MRT analysis, population structure explained mean differences in cellular and biochemical heat stress responses, especially in the group

  3. Effect of heat-killed Lactobacillus brevis SBC8803 on cutaneous arterial sympathetic nerve activity, cutaneous blood flow and transepidermal water loss in rats.

    Science.gov (United States)

    Horii, Y; Kaneda, H; Fujisaki, Y; Fuyuki, R; Nakakita, Y; Shigyo, T; Nagai, K

    2014-05-01

    To evaluate the efficacy of the effects of heat-killed Lactobacillus brevis SBC8803 (HK-SBC8803) on the standard physiological markers of skin health of cutaneous arterial sympathetic nerve activity (CASNA), cutaneous blood flow and transepidermal water loss (TEWL) and to determine whether SBC8803 targets serotonin 5-HT3 receptors in rats. A set of three experiments were conducted to examine the effects of SBC8803 on CASNA, cutaneous blood flow and TEWL using Wistar and hairless rats. Two additional experiments further attempted to determine whether HK-SBC8803 was targeting the serotonin 5-HT3 receptors by pretreatment with the 5-HT3 antagonist granisetron. Administration of HK-SBC8803 in the first three experiments caused marked inhibition of CASNA and significant elevation of cutaneous blood flow under urethane anaesthesia as well as significant decrease in TEWL on the dorsal skin of conscious hairless rats. Pretreatment with granisetron decreased the effects of HK-SBC8803 on CASNA and cutaneous blood flow. These findings suggest that HK-SBC8803 reduces CASNA, increases cutaneous blood flow and decreases TEWL and that 5-HT3 receptors may be involved in CASNA and cutaneous blood flow responses. HK-SBC8803 could be a useful substance in the treatment/prevention of skin problems, specifically chapped or dry skin. © 2014 The Society for Applied Microbiology.

  4. Canonical Modeling of the Multi-Scale Regulation of the Heat Stress Response in Yeast

    Directory of Open Access Journals (Sweden)

    Luis L. Fonseca

    2012-02-01

    Full Text Available Heat is one of the most fundamental and ancient environmental stresses, and response mechanisms are found in prokaryotes and shared among most eukaryotes. In the budding yeast Saccharomyces cerevisiae, the heat stress response involves coordinated changes at all biological levels, from gene expression to protein and metabolite abundances, and to temporary adjustments in physiology. Due to its integrative multi-level-multi-scale nature, heat adaptation constitutes a complex dynamic process, which has forced most experimental and modeling analyses in the past to focus on just one or a few of its aspects. Here we review the basic components of the heat stress response in yeast and outline what has been done, and what needs to be done, to merge the available information into computational structures that permit comprehensive diagnostics, interrogation, and interpretation. We illustrate the process in particular with the coordination of two metabolic responses, namely the dramatic accumulation of the protective disaccharide trehalose and the substantial change in the profile of sphingolipids, which in turn affect gene expression. The proposed methods primarily use differential equations in the canonical modeling framework of Biochemical Systems Theory (BST, which permits the relatively easy construction of coarse, initial models even in systems that are incompletely characterized.

  5. Babcock and Wilcox revisions to CONTEMPT, computer program for predicting containment pressure-temperature response to a loss-of-coolant accident

    International Nuclear Information System (INIS)

    Hsii, Y.H.

    1975-01-01

    The CONTEMPT computer program predicts the pressure-temperature response of a single-volume reactor building to a loss-of-coolant accident. The analytical model used for the program is described. CONTEMPT assumes that the loss-of-coolant accident can be separated into two phases; the primary system blowdown and reactor building pressurization. The results of the blowdown analysis serve as the boundary conditions and are input to the CONTEMPT program. Thus, the containment model is only concerned with the pressure and temperature in the reactor building and the temperature distribution through the reactor building structures. The program also calculates building leakage and the effects of engineered safety features such as reactor building sprays, decay heat coolers, sump coolers, etc. 11 references. (U.S.)

  6. Heat exchangers

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, E L; Eisenmann, G; Hahne, E [Stuttgart Univ. (TH) (F.R. Germany). Inst. fuer Thermodynamik und Waermetechnik

    1976-04-01

    A survey is presented on publications on design, heat transfer, form factors, free convection, evaporation processes, cooling towers, condensation, annular gap, cross-flowed cylinders, axial flow through a bundle of tubes, roughnesses, convective heat transfer, loss of pressure, radiative heat transfer, finned surfaces, spiral heat exchangers, curved pipes, regeneraters, heat pipes, heat carriers, scaling, heat recovery systems, materials selection, strength calculation, control, instabilities, automation of circuits, operational problems and optimization.

  7. Genome-wide analysis identifies chickpea (Cicer arietinum) heat stress transcription factors (Hsfs) responsive to heat stress at the pod development stage.

    Science.gov (United States)

    Chidambaranathan, Parameswaran; Jagannadham, Prasanth Tej Kumar; Satheesh, Viswanathan; Kohli, Deshika; Basavarajappa, Santosh Halasabala; Chellapilla, Bharadwaj; Kumar, Jitendra; Jain, Pradeep Kumar; Srinivasan, R

    2018-05-01

    The heat stress transcription factors (Hsfs) play a prominent role in thermotolerance and eliciting the heat stress response in plants. Identification and expression analysis of Hsfs gene family members in chickpea would provide valuable information on heat stress responsive Hsfs. A genome-wide analysis of Hsfs gene family resulted in the identification of 22 Hsf genes in chickpea in both desi and kabuli genome. Phylogenetic analysis distinctly separated 12 A, 9 B, and 1 C class Hsfs, respectively. An analysis of cis-regulatory elements in the upstream region of the genes identified many stress responsive elements such as heat stress elements (HSE), abscisic acid responsive element (ABRE) etc. In silico expression analysis showed nine and three Hsfs were also expressed in drought and salinity stresses, respectively. Q-PCR expression analysis of Hsfs under heat stress at pod development and at 15 days old seedling stage showed that CarHsfA2, A6, and B2 were significantly upregulated in both the stages of crop growth and other four Hsfs (CarHsfA2, A6a, A6c, B2a) showed early transcriptional upregulation for heat stress at seedling stage of chickpea. These subclasses of Hsfs identified in this study can be further evaluated as candidate genes in the characterization of heat stress response in chickpea.

  8. The condensation of steam on the external surfaces of the shells of HIFAR heavy water heat exchangers during a loss-of-coolant accident

    International Nuclear Information System (INIS)

    Chapman, A.G.

    1987-03-01

    A study of steam condensation rates on the HIFAR heavy water heat exchangers was undertaken to predict thermohydraulic conditions in the HIFAR containment during a postulated loss-of-coolant accident (LOCA). The process of surface condensation from a mixture of air and steam, and methods for calculating the rate of condensation, are briefly reviewed. Suitable experimental data are used to estimate coefficients of condensation heat transfer to cool surfaces in a reactor containment during a LOCA. The relevance of the available data to a LOCA in the HIFAR materials testing reactor is examined, and two sets of data are compared. The differences between air/H 2 O and air/D 2 O mixtures are discussed. Formulae are derived for the estimation of the coefficient of heat transfer from the heat exchanger shells to the cooling water, and a method of calculating the rate of condensation per unit area of surface is developed

  9. Thermal storage in a heat pump heated living room floor for urban district power balancing - effects on thermal comfort, energy loss and costs for residents

    NARCIS (Netherlands)

    van Leeuwen, Richard Pieter; de Wit, J.B.; Fink, J.; Smit, Gerardus Johannes Maria

    2014-01-01

    For the Dutch smart grid demonstration project Meppelenergie, the effects of controlled thermal energy storage within the floor heating structure of a living room by a heat pump are investigated. Storage possibilities are constrained by room operative and floor temperatures. Simulations indicate

  10. Loss of proteostatic control as a substrate for Atrial Fibrillation; a novel target for upstream therapy by Heat Shock Proteins

    Directory of Open Access Journals (Sweden)

    Roelien Amanda Marjolein Meijering

    2012-02-01

    Full Text Available Atrial Fibrillation (AF is the most common, sustained clinical tachyarrhythmia associated with significant morbidity and mortality. AF is a persistent condition with progressive structural remodeling of the atrial cardiomyocytes due to the AF itself, resulting in cellular changes commonly observed in ageing and in other heart diseases. While rhythm control by electrocardioversion or drug treatment is the treatment of choice in symptomatic AF patients, its effectiveness is still limited. Current research is directed at preventing new-onset AF by limiting the development of substrates underlying AF promotion and resembles mechanism-based therapy. Upstream therapy refers to the use of non-ion channel anti-arrhythmic drugs that modify the atrial substrate- or target-specific mechanisms of AF, with the ultimate aim to prevent the occurrence (primary prevention or recurrence of the arrhythmia following (spontaneous conversion (secondary prevention.Heat shock proteins (HSPs are molecular chaperones and comprise a large family of proteins involved in the protection against various forms of cellular stress. Their classical function is the conservation of proteostasis via prevention of toxic protein aggregation by binding to (partially unfolded proteins. Our recent data reveal that HSPs prevent electrical, contractile and structural remodeling of cardiomyocytes, thus attenuating the AF substrate in cellular, Drosophila melanogaster and animal experimental models. Furthermore, studies in humans suggest a protective role for HSPs against the progression from paroxysmal AF to persistent AF and in recurrence of AF. In this review, we discuss upregulation of the heat shock response system as a novel target for upstream therapy to prevent derailment of proteostasis and consequently promotion and recurrence of AF.

  11. Changes in body temperature in king penguins at sea: the result of fine adjustments in peripheral heat loss?

    Science.gov (United States)

    Schmidt, Alexander; Alard, Frank; Handrich, Yves

    2006-09-01

    To investigate thermoregulatory adjustments at sea, body temperatures (the pectoral muscle and the brood patch) and diving behavior were monitored during a foraging trip of several days at sea in six breeding king penguins Aptenodytes patagonicus. During inactive phases at sea (water temperature: 4-7 degrees C), all tissues measured were maintained at normothermic temperatures. The brood patch temperature was maintained at the same values as those measured when brooding on shore (38 degrees C). This high temperature difference causes a significant loss of heat. We hypothesize that high-energy expenditure associated with elevated peripheral temperature when resting at sea is the thermoregulatory cost that a postabsorptive penguin has to face for the restoration of its subcutaneous body fat. During diving, mean pectoral temperature was 37.6 +/- 1.6 degrees C. While being almost normothermic on average, the temperature of the pectoral muscle was still significantly lower than during inactivity in five out of the six birds and underwent temperature drops of up to 5.5 degrees C. Mean brood patch temperature was 29.6 +/- 2.5 degrees C during diving, and temperature decreases of up to 21.6 degrees C were recorded. Interestingly, we observed episodes of brood patch warming during the descent to depth, suggesting that, in some cases, king penguins may perform active thermolysis using the brood patch. It is hypothesized that functional pectoral temperature may be regulated through peripheral adjustments in blood perfusion. These two paradoxical features, i.e., lower temperature of deep tissues during activity and normothermic peripheral tissues while inactive, may highlight the key to the energetics of this diving endotherm while foraging at sea.

  12. Memory Loss and the Onset of Alzheimer's Disease Could Be Under the Control of Extracellular Heat Shock Proteins.

    Science.gov (United States)

    Arispe, Nelson; De Maio, Antonio

    2018-04-17

    Alzheimer's disease (AD) is a major contemporary and escalating malady in which amyloid-β (Aβ) peptides are the most likely causative agent. Aβ peptides spontaneously tend to aggregate in extracellular fluids following a progression from a monomeric state, through intermediate forms, ending in amyloid fibers and plaques. It is generally accepted now that the neurotoxic agents leading to cellular death, memory loss, and other AD characteristics are the Aβ intermediate aggregated states. However, Aβ peptides are continuously produced, released into the extracellular space, and rapidly cleared from healthy brains. Coincidentally, members of the heat shock proteins (hsp) family are present in the extracellular medium of healthy cells and body fluids, opening the possibility that hsps and Aβ could meet and interact in the extracellular milieu of the brain. In this perspective and reflection article, we place our investigation showing that the presence of Hsp70s mitigate the formation of low molecular weight Aβ peptide oligomers resulting in a reduction of cellular toxicity, in context of the current understanding of the disease. We propose that it may be an inverse relationship between the presence of Hsp70, the stage of Aβ oligomers, neurotoxicity, and the incidence of AD, particularly since the expression and circulating levels of hsp decrease with aging. Combining these observations, we propose that changes in the dynamics of Hsp70s and Aβ concentrations in the circulating brain fluids during aging defines the control of the formation of Aβ toxic aggregates, thus determining the conditions for neuron degeneration and the incidence of AD.

  13. Revisiting Gill's Circulation. Dynamic Response to Diabatic Heating of Different Horizontal Extents

    Science.gov (United States)

    Reboredo, B.; Bellon, G.

    2017-12-01

    The horizontal extent of diabatic heating associated with the MJO is thought to be crucial to its development, and the inability of GCMs to simulate the spatial, horizontal organization of clouds is considered a leading hypothesis to explain their limited capacity to simulate MJO events. This prevents the MJO large-circulation response from developing and feeding back on the development of clouds. We apply mid-tropospheric heating of different size in simple linear and non-linear models of the tropical atmosphere following Gill's seminal work on heat-induced tropical circulations. Results show that there is a scale for which the characteristic circulation {Γ c} for the vertical advection of moisture to produce the latent heat mean {Q} gives a rough estimate of the real world MJO scale. Overturning circulation flow rates above {Γ c} account for a circulation that transports more moisture than necessary to be maintained, and below {Γ c}, circulation would not transport enough moisture to maintain circulation. This dynamic scale might constrain the size of the spatially-organised convection necessary to the development of an MJO event. However, other effects are expected to modulate this scale, such as vertical advection of moisture anomalies, horizontal advection, evaporation, radiative heating, and sensible heat fluxes.

  14. Stress proteins in lymphocytes: Membrane stabilization does not affect the heat shock response

    International Nuclear Information System (INIS)

    Hughes, C.S.; Repasky, E.A.; Subjeck, J.R.

    1987-01-01

    Temperatures which have been used to induce heat shock proteins (hsps) have been at the upper physiologic limit or well above this limit. In addition, little attention has been given to the effects of physiologic heat exposures on hsp induction in lymphocytes. The author examined temperatures between 39 0 C and 41 0 C on protein synthesis in the following lymphoid cell lines and cells: BDK, EL-4, JM, DO.11, and in dispersed lymph nodes and thymic tissues. In these studies, 39.5 0 appears to be the threshold for hsp induction (as distinguished by gel electrophoresis). At this temperature the induction of the major hsps at 70 and 89 kDa are observed. Hsp 89 appears to be the most strongly induced in all cells examined. In JM cells, a human cell line, heat shock also induces hsp 68, the non-constitutive hsp at this size. These temperatures do not depress normal levels of protein synthesis. When stearic acid or cholesterol was added to lymphocyte cultures prior to heating (which stabilize membranes), hsp induction appears to occur in a manner indistinguishable from cells heated in normal media. This suggests that membrane fluidity (as influenced by these agents) does not affect or depress the heat shock response in these cells. Finally, the authors observed that 2-deoxyglucose and other inducers of glucose regulated proteins in fibroblasts also induce the major glucose regulated proteins in lymphocytes

  15. Preliminary findings of cerebral responses on transcutaneous vagal nerve stimulation on experimental heat pain.

    Science.gov (United States)

    Usichenko, Taras; Laqua, René; Leutzow, Bianca; Lotze, Martin

    2017-02-01

    Transcutaneous vagal nerve stimulation (TVNS) is a promising complementary method of pain relief. However, the neural networks associated with its analgesic effects are still to be elucidated. Therefore, we conducted two functional magnetic resonance imaging (fMRI) sessions, in a randomized order, with twenty healthy subjects who were exposed to experimental heat pain stimulation applied to the right forearm using a Contact Heat-Evoked Potential Stimulator. While in one session TVNS was administered bilaterally to the concha auriculae with maximal, non-painful intensity, the stimulation device was switched off in the other session (placebo condition). Pain thresholds were measured before and after each session. Heat stimulation elicited fMRI activation in cerebral pain processing regions. Activation magnitude in the secondary somatosensory cortex, posterior insula, anterior cingulate and caudate nucleus was associated with heat stimulation without TVNS. During TVNS, this association was only seen for the right anterior insula. TVNS decreased fMRI signals in the anterior cingulate cortex in comparison with the placebo condition; however, there was no relevant pain reducing effect over the group as a whole. In contrast, TVNS compared to the placebo condition showed an increased activation in the primary motor cortex, contralateral to the site of heat stimulation, and in the right amygdala. In conclusion, in the protocol used here, TVNS specifically modulated the cerebral response to heat pain, without having a direct effect on pain thresholds.

  16. Experimental investigation of a multicylinder unmodified diesel engine performance, emission, and heat loss characteristics using different biodiesel blends: rollout of B10 in Malaysia.

    Science.gov (United States)

    Abedin, M J; Masjuki, H H; Kalam, M A; Varman, M; Arbab, M I; Fattah, I M Rizwanul; Masum, B M

    2014-01-01

    This paper deals with the performance and emission analysis of a multicylinder diesel engine using biodiesel along with an in-depth analysis of the engine heat losses in different subsystems followed by the energy balance of all the energy flows from the engine. Energy balance analysis allows the designer to appraise the internal energy variations of a thermodynamic system as a function of ''energy flows" across the control volume as work or heat and also the enthalpies associated with the energy flows which are passing through these boundaries. Palm and coconut are the two most potential biodiesel feed stocks in this part of the world. The investigation was conducted in a four-cylinder diesel engine fuelled with 10% and 20% blends of palm and coconut biodiesels and compared with B5 at full load condition and in the speed range of 1000 to 4000 RPM. Among the all tested blends, palm blends seemed more promising in terms of engine performance, emission, and heat losses. The influence of heat losses on engine performance and emission has been discussed thoroughly in this paper.

  17. Experimental Investigation of a Multicylinder Unmodified Diesel Engine Performance, Emission, and Heat Loss Characteristics Using Different Biodiesel Blends: Rollout of B10 in Malaysia

    Directory of Open Access Journals (Sweden)

    M. J. Abedin

    2014-01-01

    Full Text Available This paper deals with the performance and emission analysis of a multicylinder diesel engine using biodiesel along with an in-depth analysis of the engine heat losses in different subsystems followed by the energy balance of all the energy flows from the engine. Energy balance analysis allows the designer to appraise the internal energy variations of a thermodynamic system as a function of ‘‘energy flows’’ across the control volume as work or heat and also the enthalpies associated with the energy flows which are passing through these boundaries. Palm and coconut are the two most potential biodiesel feed stocks in this part of the world. The investigation was conducted in a four-cylinder diesel engine fuelled with 10% and 20% blends of palm and coconut biodiesels and compared with B5 at full load condition and in the speed range of 1000 to 4000 RPM. Among the all tested blends, palm blends seemed more promising in terms of engine performance, emission, and heat losses. The influence of heat losses on engine performance and emission has been discussed thoroughly in this paper.

  18. Improvements in modelling (by ESCADRE mod1.0) radiative heat losses through gas and aerosols generated by molten corium-concrete interactions

    International Nuclear Information System (INIS)

    Passalacqua, R.

    1996-01-01

    Aerosols generated during the molten core-concrete interaction (MCCI) influence the reactor cavity thermal hydraulics: the cloud of aerosols, located inside the reactor cavity, restrains the upward-directed heat exchange consequently the cool-down of the high-temperature molten corium for a considerable period of time. IPSN is developing a computer code system for source predictions in severe accident scenarios. This code system is named ESCADRE. WECHSL/CALTHER is internal module dealing with MCCI (it is also a stand-alone code): it models the heat transfers involving the superior volume of the cavity. When modelling the upward-directed power distribution by WECHSL/CALTHER, a faster concrete basemat penetration takes place due to the low heat losses of the closed MCCI cavity enclosure. The model, here presented, is going to be validated with data from the AEROSTAT experiment. This experiment, planned at CEA Cadarache, will evaluate the influence of aerosols on the global power distribution in the reactor cavity. Radiative heat losses are important especially for cavity configurations such as those of new plant designs (equipped with a core-catcher) where the upward power losses are promoted by the corium spreading in a flat cavity

  19. The Mycoplasma hyopneumoniae recombinant heat shock protein P42 induces an immune response in pigs under field conditions.

    Science.gov (United States)

    Jorge, Sérgio; de Oliveira, Natasha Rodrigues; Marchioro, Silvana Beutinger; Fisch, Andressa; Gomes, Charles Klazer; Hartleben, Cláudia Pinho; Conceição, Fabricio Rochedo; Dellagostin, Odir Antonio

    2014-09-01

    Enzootic pneumonia (EP), resulting from Mycoplasma hyopneumoniae infection is one of the most prevalent diseases in pigs and is a major cause of economic losses to the swine industry worldwide. EP is often controlled by vaccination with inactivated, adjuvanted whole-cell bacterin. However, these bacterins provide only partial protection and do not prevent M. hyopneumoniae colonization. Attempts to develop vaccines that are more efficient have made use of the recombinant DNA technology. The objective of this study was to assess the potential of recombinant M. hyopneumoniae heat shock protein P42 in vaccine preparations against EP, using piglets housed under field conditions in a M. hyopneumoniae-positive farm. The cellular and humoral immune responses were elicited after a single intramuscular inoculation of rP42 in an oil-based adjuvant, or in conjunction with whole-cell vaccine preparation. The production of INF-γ and IL-10 cytokines was quantified in the supernatant of the cultured mononuclear cells. The rP42 emulsified in oil-based adjuvant was able to trigger a strong humoral immune response. Further, it induced a cellular immune response, accompanied by the production of antibodies that reacted with the native M. hyopneumoniae protein. The rP42 mediated induction of cellular and humoral immune response in the host suggests that rP42 emulsified in an oil-based adjuvant holds promise as an effective recombinant subunit vaccine against EP. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. Heat response of mouse tumor cells treated with 5-thio-D-glucose and Rhodamine-123

    International Nuclear Information System (INIS)

    Rhee, J.G.; Lyons, J.C.; Song, C.W.

    1987-01-01

    Cellular heat-sensitivity has been known to depend on intracellular energy. The authors studied the thermal response of cultured SCK mammary carcinoma cells in vitro, following glycolytic inhibition with 5-thio-D-glucose (TG) and mitochondrial inactivation with Rhodamine-123 (Rh). The cells in exponential growth phase in RPMI 1640 medium supplemented with serum and antibiotics were exposed to medium containing Rh and/or TG, heated in a prewarmed water bath, and the clonogenic survivals of the heated cells were determined. Thermal cell killing by the 30 min. heating was increased, when 10 and 20 μg/ml Rh were present in the medium at temperatures above 42 0 and 40 0 C, respectively. The slope of the heat survival curve for 43 0 C heating became steeper in the presence of 10 and 20 μg/ml Rh, and the initial shoulder of the survival curve was unaltered at the dose of 10 μg/ml Rh, but disappeared at 20 μg/ml. A TG dose of 3 mg/ml, which is about 10 times that necessary to kill 90% of cells in 5 hrs. under hypoxic condition, was ineffective in altering any parameters of the heat survival curve of aerobic cells. The combined effect of TG and Rh on the thermal cell killing in aerobic condition did not exceed the effect of Rh alone. The above results indicate that the energy supply derived by mitochondria is an important determinant for the shape of heat survival curve of the proliferating and aerobic SCK tumor cells

  1. Inflammatory cytokines and plasma redox status responses in hypertensive subjects after heat exposure

    Directory of Open Access Journals (Sweden)

    S.F. Fonseca

    2016-03-01

    Full Text Available Hypertension is characterized by a pro-inflammatory status, including redox imbalance and increased levels of pro-inflammatory cytokines, which may be exacerbated after heat exposure. However, the effects of heat exposure, specifically in individuals with inflammatory chronic diseases such as hypertension, are complex and not well understood. This study compared the effects of heat exposure on plasma cytokine levels and redox status parameters in 8 hypertensive (H and 8 normotensive (N subjects (age: 46.5±1.3 and 45.6±1.4 years old, body mass index: 25.8±0.8 and 25.6±0.6 kg/m2, mean arterial pressure: 98.0±2.8 and 86.0±2.3 mmHg, respectively. They remained at rest in a sitting position for 10 min in a thermoneutral environment (22°C followed by 30 min in a heated environmental chamber (38°C and 60% relative humidity. Blood samples were collected before and after heat exposure. Plasma cytokine levels were measured using sandwich ELISA kits. Plasma redox status was determined by thiobarbituric acid reactive substances (TBARS levels and ferric reducing ability of plasma (FRAP. Hypertensive subjects showed higher plasma levels of IL-10 at baseline (P<0.05, although levels of this cytokine were similar between groups after heat exposure. Moreover, after heat exposure, hypertensive individuals showed higher plasma levels of soluble TNF receptor (sTNFR1 and lower TBARS (P<0.01 and FRAP (P<0.05 levels. Controlled hypertensive subjects, who use angiotensin-converting-enzyme inhibitor (ACE inhibitors, present an anti-inflammatory status and balanced redox status. Nevertheless, exposure to a heat stress condition seems to cause an imbalance in the redox status and an unregulated inflammatory response.

  2. Controlling Price-Responsive Heat Pumps for Overload Elimination in Distribution Systems

    DEFF Research Database (Denmark)

    Csetvei, Zsuzsa; Østergaard, Jacob; Nyeng, Preben

    2011-01-01

    This paper investigates the possibility of applying electric heat pumps with the control-by-price-concept in order to avoid overload in a local distribution system. The proposed control algorithm is based upon a centrally dispatched real-time market price, reflecting the state of a larger power...... system, and is extended with a local price control for overload elimination on the corresponding feeder. The paper presents the mathematical models of a two-node system with price-responsive heat pumps, the chosen methodology of the central price calculation, and the proposed local feedback control...

  3. Weight loss, leukopenia and thrombocytopenia associated with sustained virologic response to Hepatitis C treatment

    Science.gov (United States)

    Suwantarat, Nuntra; Tice, Alan D.; Khawcharoenporn, Thana; Chow, Dominic C.

    2010-01-01

    OBJECTIVE: To identify apparent adverse effects of treatment of chronic hepatitis C and their relationship to sustained virologic response (SVR). METHODS: A retrospective study was conducted of all Hepatitis C virus (HCV)-infected patients treated with pegylated interferon and ribavirin in an academic ambulatory infectious disease practice. Clinical and laboratory characteristics were compared between patients with SVR and without SVR. RESULTS: Fifty-four patients completed therapy with the overall SVR rate of 76%. SVR was associated with genotype non-1 (P=0.01), weight loss more than 5 kilograms (P=0.04), end of treatment leukopenia (P=0.02) and thrombocytopenia (P=0.05). In multivariate analysis, SVR was significant associated with HCV genotype non-1 (Adjusted Odd Ratio [AOR] 15.22; CI 1.55 to 149.72; P=0.02), weight loss more than 5 kilograms, (AOR 5.74; CI 1.24 to 26.32; P=0.04), and end of treatment white blood cell count level less than 3 X 103 cells/µl (AOR 9.09; CI 1.59 to 52.63; P=0.02). Thrombocytopenia was not significant after adjustment. Other factors including age, gender, ethnicity, injection drug use, viral load, anemia, alanine transaminase level, and liver histology did not reach statistical significance. CONCLUSION: Besides non-1 genotype, SVR was found to be independently associated with weight loss during therapy, and leukopenia at the end of HCV treatment. These correlations suggest continuation of therapy despite adverse effects, may be of benefit. PMID:20107528

  4. Grief symptoms and difficult patient loss for oncologists in response to patient death.

    Science.gov (United States)

    Granek, Leeat; Ben-David, Merav; Shapira, Shahar; Bar-Sela, Gil; Ariad, Samuel

    2017-07-01

    The study aimed to explore oncologist's grief symptoms over patient death and to identify why and which losses are particularly challenging when patients die. The grounded theory method was used to collect and analyze the data. Twenty-two oncologists were interviewed between March 2013 and June 2014 from three adult oncology centers in the north, center, and south of Israel. Oncologists were at different stages of their careers and varied in their sub-specialties, gender, and personal and professional backgrounds. Grief begun when the patient died, in anticipation of the patient's death, many days after the death, or when the patient received a poor prognosis. The phenomenological experience of grief for oncologists included behavioral, cognitive, physical, and emotional symptoms in response to patient death. Behavioral symptoms included crying and difficulties sleeping. Cognitive symptoms included self-doubt and rumination about the patient and the care the patient had received before death. Physical symptoms included chest pain, fatigue, and general physical discomfort. Emotional symptoms included sadness, anxiety, helplessness, guilt, relief, irritability, and loss. Difficult patient loss was caused by patient-related factors, family-related factors, and disease-related factors. Patient deaths result in behavioral, cognitive, physical, and emotional symptoms of grief in oncologists. These symptoms become particularly intense in the context of patient, family, and disease-related factors. Educational and supportive interventions for managing grief related to patient death are needed in order to support oncologists in their emotionally and mentally taxing work. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  5. Auditory brainstem response screening for hearing loss in high risk neonates.

    Science.gov (United States)

    Watson, D R; McClelland, R J; Adams, D A

    1996-07-01

    The present paper reports the findings of a 7 year study evaluating the use of the auditory brainstem response (ABR) as the basis of a hearing screening procedure in a group of newborns at increased risk of hearing impairment. A Special Care Baby Unit (SCBU) population of 417 infants with diverse clinical backgrounds and treatment histories was tested for hearing impairment at birth using ABR audiometry. Some 332 passed the original screen at 30 dBnHL test level in both ears. Of the failure group, 18 did not survive and 32 had some degree of hearing impairment confirmed, nine of which were sensorineural in origin. An increased incidence of persistent middle ear disease was also noted in the failure group. A detailed operational analysis demonstrates that provided appropriate pass/fail criteria are adopted, the ABR technique offers excellent sensitivity and specificity for the detection of significant hearing loss in the test population. Furthermore, the study establishes that implementation of an ABR-based screening programme could reduce the average age at detection of permanent hearing loss by 7 months. A cost assessment shows that the introduction of such a targetted screening procedure could be done at a reasonable outlay.

  6. Applications of Solar Technology for Catastrophe Response, Claims Management, and Loss Prevention

    Energy Technology Data Exchange (ETDEWEB)

    Deering, A.; Thornton, J.P.

    1999-02-17

    Today's insurance industry strongly emphasizes developing cost-effective hazard mitigation programs, increasing and retaining commercial and residential customers through better service, educating customers on their exposure and vulnerabilities to natural disasters, collaborating with government agencies and emergency management organizations, and exploring the use of new technologies to reduce the financial impact of disasters. In June of 1998, the National Renewable Energy Laboratory (NREL) and the National Association of Independent Insurers (NAII) sponsored a seminar titled, ''Solar Technology and the Insurance Industry.'' Presentations were made by insurance company representatives, insurance trade groups, government and state emergency management organizations, and technology specialists. The meeting was attended by insurers, brokers, emergency managers, and consultants from more than 25 US companies. Leading insurers from the personal line and commercial carriers were shown how solar technology can be used in underwriting, claims, catastrophe response, loss control, and risk management. Attendees requested a follow-up report on solar technology, cost, and applications in disasters, including suggestions on how to collaborate with the utility industry and how to develop educational programs for business and consumers. This report will address these issues, with an emphasis on pre-disaster planning and mitigation alternatives. It will also discuss how energy efficiency and renewable technologies can contribute to reducing insurance losses.

  7. Occupational heat stress and associated productivity loss estimation using the PHS model (ISO 7933): a case study from workplaces in Chennai, India

    Science.gov (United States)

    Lundgren, Karin; Kuklane, Kalev; Venugopal, Vidhya

    2014-01-01

    Background Heat stress is a major occupational problem in India that can cause adverse health effects and reduce work productivity. This paper explores this problem and its impacts in selected workplaces, including industrial, service, and agricultural sectors in Chennai, India. Design Quantitative measurements of heat stress, workload estimations, and clothing testing, and qualitative information on health impacts, productivity loss, etc., were collected. Heat strain and associated impacts on labour productivity between the seasons were assessed using the International Standard ISO 7933:2004, which applies the Predicted Heat Strain (PHS) model. Results and conclusions All workplaces surveyed had very high heat exposure in the hot season (Wet Bulb Globe Temperature x¯ =29.7), often reaching the international standard safe work values (ISO 7243:1989). Most workers had moderate to high workloads (170–220 W/m2), with some exposed to direct sun. Clothing was found to be problematic, with high insulation values in relation to the heat exposure. Females were found to be more vulnerable because of the extra insulation added from wearing a protective shirt on top of traditional clothing (0.96 clo) while working. When analysing heat strain – in terms of core temperature and dehydration – and associated productivity loss in the PHS model, the parameters showed significant impacts that affected productivity in all workplaces, apart from the laundry facility, especially during the hot season. For example, in the canteen, the core temperature limit of 38°C predicted by the model was reached in only 64 min for women. With the expected increases in temperature due to climate change, additional preventive actions have to be implemented to prevent further productivity losses and adverse health impacts. Overall, this study presented insight into using a thermo-physiological model to estimate productivity loss due to heat exposure in workplaces. This is the first time the PHS

  8. Mathematical model for heat loss calculation through a window; Modelo para el calculo de la perdida de calor por una ventana

    Energy Technology Data Exchange (ETDEWEB)

    Fissore Sch, Adelqui; Cuevas B, Cristian [Universidad de Concepcion (Chile). Facultad de Ingenieria. Dept. de Ingenieria Mecanica]. E-mail: afissore@udec.cl; ccuevas@udec.cl

    2000-07-01

    In the present work a semi-empirical model for heat loss by convection at an indoor window surface with curtain or blind is given. With this model, the convection heat transfer coefficient and temperature of the air at confined space between the curtain and the glass can be calculated. The curtain was modeled with a paper due to the low thermal inertia that it has. The model is based on experimental data obtained for four separations between the paper and the window. Data from numerical simulation program are also used. (author)

  9. Occupational heat stress and associated productivity loss estimation using the PHS model (ISO 7933: a case study from workplaces in Chennai, India

    Directory of Open Access Journals (Sweden)

    Karin Lundgren

    2014-11-01

    Full Text Available Background: Heat stress is a major occupational problem in India that can cause adverse health effects and reduce work productivity. This paper explores this problem and its impacts in selected workplaces, including industrial, service, and agricultural sectors in Chennai, India. Design: Quantitative measurements of heat stress, workload estimations, and clothing testing, and qualitative information on health impacts, productivity loss, etc., were collected. Heat strain and associated impacts on labour productivity between the seasons were assessed using the International Standard ISO 7933:2004, which applies the Predicted Heat Strain (PHS model. Results and conclusions: All workplaces surveyed had very high heat exposure in the hot season (Wet Bulb Globe Temperature x¯ =29.7, often reaching the international standard safe work values (ISO 7243:1989. Most workers had moderate to high workloads (170–220 W/m2, with some exposed to direct sun. Clothing was found to be problematic, with high insulation values in relation to the heat exposure. Females were found to be more vulnerable because of the extra insulation added from wearing a protective shirt on top of traditional clothing (0.96 clo while working. When analysing heat strain – in terms of core temperature and dehydration – and associated productivity loss in the PHS model, the parameters showed significant impacts that affected productivity in all workplaces, apart from the laundry facility, especially during the hot season. For example, in the canteen, the core temperature limit of 38°C predicted by the model was reached in only 64 min for women. With the expected increases in temperature due to climate change, additional preventive actions have to be implemented to prevent further productivity losses and adverse health impacts. Overall, this study presented insight into using a thermo-physiological model to estimate productivity loss due to heat exposure in workplaces. This is the

  10. ER Stress Causes Rapid Loss of Intestinal Epithelial Stemness through Activation of the Unfolded Protein Response

    Directory of Open Access Journals (Sweden)

    Jarom Heijmans

    2013-04-01

    Full Text Available Stem cells generate rapidly dividing transit-amplifying cells that have lost the capacity for self-renewal but cycle for a number of times until they exit the cell cycle and undergo terminal differentiation. We know very little of the type of signals that trigger the earliest steps of stem cell differentiation and mediate a stem cell to transit-amplifying cell transition. We show that in normal intestinal epithelium, endoplasmic reticulum (ER stress and activity of the unfolded protein response (UPR are induced at the transition from stem cell to transit-amplifying cell. Induction of ER stress causes loss of stemness in a Perk-eIF2α-dependent manner. Inhibition of Perk-eIF2α signaling results in stem cell accumulation in organoid culture of primary intestinal epithelium. Our findings show that the UPR plays an important role in the regulation of intestinal epithelial stem cell differentiation.

  11. Response of EBR-II to a complete loss of primary forced flow during power operation

    International Nuclear Information System (INIS)

    Singer, R.M.; Gillette, J.L.; Mohr, D.; Tokar, J.V.; Sullivan, J.E.; Dean, E.M.

    1980-01-01

    Detailed measurements of the thermal, hydraulic, and neutronic response of EBR-II to a complete loss of primary forced flow followed by a PPS-activated scram are presented. The experimental results clearly indicate a smooth transition to natural convective flow with a quite modest incore temperature transient. The accompanying calculations using the NATDEMO code agree quite well with the measured temperatures and flow rates throughout the primary system. The only region of the plant where a significant discrepancy between the measurements and calculations occurred was in the IHX. The reasons for this result could not be definitively determined, but it is speculated that the one-dimensional assumptions used in the modeling may not be valid in the IHX during buoyancy driver flows

  12. Global crop yield response to extreme heat stress under multiple climate change futures

    Science.gov (United States)

    Deryng, D.; Conway, D.; Ramankutty, N.; Price, J.; Warren, R.

    2014-12-01

    Extreme heat stress during the crop reproductive period can be critical for crop productivity. Projected changes in the frequency and severity of extreme climatic events are expected to negatively impact crop yields and global food production. This study applies the global crop model PEGASUS to quantify, for the first time at the global scale, impacts of extreme heat stress on maize, spring wheat and soybean yields resulting from 72 climate change scenarios for the 21st century. Our results project maize to face progressively worse impacts under a range of RCPs but spring wheat and soybean to improve globally through to the 2080s due to CO2 fertilization effects, even though parts of the tropic and sub-tropic regions could face substantial yield declines. We find extreme heat stress at anthesis (HSA) by the 2080s (relative to the 1980s) under RCP 8.5, taking into account CO2 fertilization effects, could double global losses of maize yield (dY = -12.8 ± 6.7% versus -7.0 ± 5.3% without HSA), reduce projected gains in spring wheat yield by half (dY = 34.3 ± 13.5% versus 72.0 ± 10.9% without HSA) and in soybean yield by a quarter (dY = 15.3 ± 26.5% versus 20.4 ± 22.1% without HSA). The range reflects uncertainty due to differences between climate model scenarios; soybean exhibits both positive and negative impacts, maize is generally negative and spring wheat generally positive. Furthermore, when assuming CO2 fertilization effects to be negligible, we observe drastic climate mitigation policy as in RCP 2.6 could avoid more than 80% of the global average yield losses otherwise expected by the 2080s under RCP 8.5. We show large disparities in climate impacts across regions and find extreme heat stress adversely affects major producing regions and lower income countries.

  13. Complex Effects of Ecosystem Engineer Loss on Benthic Ecosystem Response to Detrital Macroalgae.

    Directory of Open Access Journals (Sweden)

    Francesca Rossi

    Full Text Available Ecosystem engineers change abiotic conditions, community assembly and ecosystem functioning. Consequently, their loss may modify thresholds of ecosystem response to disturbance and undermine ecosystem stability. This study investigates how loss of the bioturbating lugworm Arenicola marina modifies the response to macroalgal detrital enrichment of sediment biogeochemical properties, microphytobenthos and macrofauna assemblages. A field manipulative experiment was done on an intertidal sandflat (Oosterschelde estuary, The Netherlands. Lugworms were deliberately excluded from 1× m sediment plots and different amounts of detrital Ulva (0, 200 or 600 g Wet Weight were added twice. Sediment biogeochemistry changes were evaluated through benthic respiration, sediment organic carbon content and porewater inorganic carbon as well as detrital macroalgae remaining in the sediment one month after enrichment. Microalgal biomass and macrofauna composition were measured at the same time. Macroalgal carbon mineralization and transfer to the benthic consumers were also investigated during decomposition at low enrichment level (200 g WW. The interaction between lugworm exclusion and detrital enrichment did not modify sediment organic carbon or benthic respiration. Weak but significant changes were instead found for porewater inorganic carbon and microalgal biomass. Lugworm exclusion caused an increase of porewater carbon and a decrease of microalgal biomass, while detrital enrichment drove these values back to values typical of lugworm-dominated sediments. Lugworm exclusion also decreased the amount of macroalgae remaining into the sediment and accelerated detrital carbon mineralization and CO2 release to the water column. Eventually, the interaction between lugworm exclusion and detrital enrichment affected macrofauna abundance and diversity, which collapsed at high level of enrichment only when the lugworms were present. This study reveals that in nature the

  14. Complex Effects of Ecosystem Engineer Loss on Benthic Ecosystem Response to Detrital Macroalgae.

    Science.gov (United States)

    Rossi, Francesca; Gribsholt, Britta; Gazeau, Frederic; Di Santo, Valentina; Middelburg, Jack J

    2013-01-01

    Ecosystem engineers change abiotic conditions, community assembly and ecosystem functioning. Consequently, their loss may modify thresholds of ecosystem response to disturbance and undermine ecosystem stability. This study investigates how loss of the bioturbating lugworm Arenicola marina modifies the response to macroalgal detrital enrichment of sediment biogeochemical properties, microphytobenthos and macrofauna assemblages. A field manipulative experiment was done on an intertidal sandflat (Oosterschelde estuary, The Netherlands). Lugworms were deliberately excluded from 1× m sediment plots and different amounts of detrital Ulva (0, 200 or 600 g Wet Weight) were added twice. Sediment biogeochemistry changes were evaluated through benthic respiration, sediment organic carbon content and porewater inorganic carbon as well as detrital macroalgae remaining in the sediment one month after enrichment. Microalgal biomass and macrofauna composition were measured at the same time. Macroalgal carbon mineralization and transfer to the benthic consumers were also investigated during decomposition at low enrichment level (200 g WW). The interaction between lugworm exclusion and detrital enrichment did not modify sediment organic carbon or benthic respiration. Weak but significant changes were instead found for porewater inorganic carbon and microalgal biomass. Lugworm exclusion caused an increase of porewater carbon and a decrease of microalgal biomass, while detrital enrichment drove these values back to values typical of lugworm-dominated sediments. Lugworm exclusion also decreased the amount of macroalgae remaining into the sediment and accelerated detrital carbon mineralization and CO2 release to the water column. Eventually, the interaction between lugworm exclusion and detrital enrichment affected macrofauna abundance and diversity, which collapsed at high level of enrichment only when the lugworms were present. This study reveals that in nature the role of this

  15. Analysis of dispersed frequency response for ionic glasses: influence of electrode and nearly constant loss effects

    International Nuclear Information System (INIS)

    Macdonald, J Ross

    2005-01-01

    Analysis by D L Sidebottom of the dispersive frequency response of the real-part of the conductivity, σ'(ω), for many alkali phosphate and metaphosphate glasses, using a fitting model involving a 'universal dynamic response' power law with an exponent n and a constant-loss term, led to anomalous n behaviour that he explained as arising from variable constriction of the local cation conduction space. In order to obtain adequate fits, he eliminated from the data all low-frequency decreases of σ'(ω) below the dc plateau, ones actually associated with electrode effects. Such a cut-off does not, however, eliminate electrode effects possibly present in the high-frequency part of the data range. The results of the present detailed analysis and fitting of both synthetic data and several of his experimental data sets show unequivocally that his anomalous n behaviour arose from neglecting electrode effects. Their inclusion, with or without data cut-off in the fitting model, leads to the expected high-frequency slope value of n = 2/3 associated with bulk conduction, as required by recently published topological effective-dimension considerations for dielectric relaxation in conductive systems. Further, the effects of the inclusion in a full fitting model of series and possibly parallel complex constant-phase-element contributions, representing electrode and nearly constant loss effects, respectively, have been investigated in detail. Such composite models usually lead to best fitting of either the full or cut-off complex data when they include the semi-universal, topologically based K1 bulk model, one indirectly derived from the assumption of stretched-exponential temporal behaviour

  16. An estimation of core damage frequency of a pressurized water reactor during midloop operation due to loss of residual heat removal

    International Nuclear Information System (INIS)

    Chao, C.C.; Chen, C.T.; Lee, M.

    1995-01-01

    The core damage frequency caused by loss of residual heat removal (RHR) events was assessed during midloop operation of a Westinghouse-designed three-loop pressurized water reactor. The assessment considers two types of outages (refueling and drained maintenance) and uses failure data collected specifically for shutdown condition. Event trees were developed for five categories of loss of RHR events. Human actions to mitigate the loss of RHR events were identified and human error probabilities were quantified using the human cognitive reliability (HCR) and the technique for human error rate prediction (THERP) models. The results showed that the core damage frequency caused by loss of RHR events during midloop operation was 3.4 x 10 -5 per year. The results also showed that the core damage frequency can be reduced significantly by removing a pressurizer safety valve before entering midloop operation. The establishment of reflux cooling, i.e., decay heat remo