WorldWideScience

Sample records for temperature effects

  1. Temperature Effect on Energy Demand

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Young Duk [Korea Energy Economics Institute, Euiwang (Korea)

    1999-03-01

    We provide various estimates of temperature effect for accommodating seasonality in energy demand, particularly natural gas demand. We exploit temperature response and monthly temperature distribution to estimate the temperature effect on natural gas demand. Both local and global smoothed temperature responses are estimated from empirical relationship between hourly temperature and hourly energy consumption data during the sample period (1990 - 1996). Monthly temperature distribution estimates are obtained by kernel density estimation from temperature dispersion within a month. We integrate temperature response and monthly temperature density over all the temperatures in the sample period to estimate temperature effect on energy demand. Then, estimates of temperature effect are compared between global and local smoothing methods. (author). 15 refs., 14 figs., 2 tabs.

  2. Cepheid radii and effective temperatures

    International Nuclear Information System (INIS)

    Fernley, J.A.; Skillen, I.; Jameson, R.F.

    1989-01-01

    New infrared photometry for the Cepheid variables T Vul, δ Cephei and XCyg is presented. Combining this with published infrared photometry of T Vul, ηAql, S Sge and XCyg and published optical photometry we use the infrared flux method to determine effective temperatures and angular radii at all phases of the pulsation cycle. These angular radii combined with published radial velocity curves then give the radii of the stars. Knowing the radii and effective temperatures we obtain the absolute magnitudes. (author)

  3. Proximity effect at Millikelvin temperatures

    International Nuclear Information System (INIS)

    Mota, A.C.

    1986-01-01

    Proximity effects have been studied extensively for the past 25 years. Typically, they are in films several thousand angstroms thick at temperatures not so far below T/sub CNS/, the transition temperature of the NS system. Interesting is, however, the proximity effect at temperatures much lower than T/sub CNS/. In this case, the Cooper-pair amplitudes are not small and very long pair penetration lengths into the normal metal can be expected. Thus, we have observed pair penetration lengths. For these investigations very suitable specimens are commercial wires of one filament of NbTi or Nb embedded in a copper matrix. The reasons are the high transmission coefficient at the interface between the copper and the superconductor and the fact that the copper in these commercial wires is rather clean with electron free paths between 5 to 10 μm long. In this paper, the magnetic properties of thick proximity systems in the range of temperatures between T/sub CNS/ and 5 x 10/sup -4/ T/sub CNS/ in both low and high magnetic fields are discussed

  4. Quantifying Temperature Effects on Fall Chinook Salmon

    Energy Technology Data Exchange (ETDEWEB)

    Jager, Yetta [ORNL

    2011-11-01

    The motivation for this study was to recommend relationships for use in a model of San Joaquin fall Chinook salmon. This report reviews literature pertaining to relationships between water temperature and fall Chinook salmon. The report is organized into three sections that deal with temperature effects on development and timing of freshwater life stages, temperature effects on incubation survival for eggs and alevin, and temperature effects on juvenile survival. Recommendations are made for modeling temperature influences for all three life stages.

  5. Effect of ambient temperature on human pain and temperature perception.

    Science.gov (United States)

    Strigo, I A; Carli, F; Bushnell, M C

    2000-03-01

    Animal studies show reduced nociceptive responses to noxious heat stimuli and increases in endogenous beta-endorphin levels in cold environments, suggesting that human pain perception may be dependent on ambient temperature. However, studies of changes in local skin temperature on human pain perception have yielded variable results. This study examines the effect of both warm and cool ambient temperature on the perception of noxious and innocuous mechanical and thermal stimuli. Ten subjects (7 men and 3 women, aged 20-23 yr) used visual analog scales to rate the stimulus intensity, pain intensity, and unpleasantness of thermal (0-50 degrees C) and mechanical (1.2-28.9 g) stimuli applied on the volar forearm with a 1-cm2 contact thermode and von Frey filaments, respectively. Mean skin temperatures were measured throughout the experiment by infrared pyrometer. Each subject was tested in ambient temperatures of 15 degrees C (cool), 25 degrees C (neutral), and 35 degrees C (warm) on separate days, after a 30-min acclimation to the environment. Studies began in the morning after an 8-h fast. Mean skin temperature was altered by ambient temperature (cool room: 30.1 degrees C; neutral room: 33.4 degrees C; warm room: 34.5 degrees C; P cool than in the neutral environment (P cool room and that noxious heat stimuli were more unpleasant in a warm environment. Environmental temperature did not alter ratings of warm (37 and 40 degrees C) or mechanical stimuli. These results indicate that, in humans, a decrease in skin temperature following exposure to cool environments reduces thermal pain. Suppression of Adelta primary afferent cold fiber activity has been shown to increase cold pain produced by skin cooling. Our current findings may represent the reverse phenomenon, i.e., a reduction in thermal nociceptive transmission by the activation of Adelta cutaneous cold fibers.

  6. Effect of temperature on quantum dots

    Indian Academy of Sciences (India)

    MAHDI AHMADI BORJI

    2017-07-12

    Jul 12, 2017 ... Effect of temperature on InxGa1−xAs/GaAs quantum dots. MAHDI AHMADI BORJI1, ALI ... Attention should be given to the effects of temperature, ... tion 2 explains the model and method of the numerical simulation. Our results ...

  7. Electrocutaneous sensitivity: effects of skin temperature.

    Science.gov (United States)

    Larkin, W D; Reilly, J P

    1986-01-01

    The effect of human skin temperature on electrocutaneous sensitivity was examined using brief capacitive discharges. Stimuli were designed to ensure that sensory effects would be independent of skin resistance and would reflect underlying neural excitability as closely as possible. Skin temperature was manipulated by immersing the forearm in circulating hot or cold air. Detection thresholds on the arm and fingertip were raised by cooling, but were not altered by heating. Temperature-related sensitivity shifts were described by the same multiplicative factors for both threshold and suprathreshold levels. The temperature coefficient (Q10) for cutaneous sensitivity under these conditions was approximately 1.3.

  8. Temperature effects in differential mobility spectrometry

    Science.gov (United States)

    Krylov, Evgeny V.; Coy, Stephen L.; Nazarov, Erkinjon G.

    2009-01-01

    Drift gas temperature and pressure influence differential mobility spectrometer (DMS) performance, changing DMS peak positions, heights and widths. This study characterizes the effect of temperature on DMS peak positions. Positive ions of methyl salicylate, DMMP, and toluene, and negative ions of methyl salicylate and the reactant ion peaks were observed in purified nitrogen in the Sionex microDMx planar DMS. Measurements were made at ambient pressure (1 atm) at temperatures from 25 °C to 150 °C in a planar sensor with height 0.5 mm. Peak value of the separation voltage asymmetric waveform was scanned from 500 V to 1500 V. Compensation voltage (DMS peak position) showed a strong variation with temperature for all investigated ions. By generalizing the concept of effective ion temperature to include the effects of inelastic ion-molecular collisions, we have been able to condense peak position dependence on separation field and temperature to dependence on a redefined effective temperature including a smoothly varying inelasticity correction. It allows prediction and correction of the gas temperature effect on DMS peak positions.

  9. ELEVATED TEMPERATURE EFFECTS ON THE ELECTRICAL ...

    African Journals Online (AJOL)

    The effects of elevated temperatures on the electrical properties of Bi metal probe to Si thin films had been investigated for electric field values 10-100V/m. Measurements of current (I) – voltage (V) characteristics were obtained at temperatures 300,320,340,360,380 and 400K respectively. The results indicated linear I–V ...

  10. MOSFET dosimetry: temperature effects in-vivo

    International Nuclear Information System (INIS)

    Yu, P.K.N.; Cheung, T.; Butson, M.J.; Cancer Services, Wollongong, NSW

    2004-01-01

    Full text: This note investigates temperature effects on dosimetry using a Metal Oxide Semiconductor Field Effect Transistor (MOSFET) for radiotherapy x-ray treatment. This was performed by analysing the dose response and threshold voltage outputs for MOSFET dosimeters as a function of ambient temperature. Results have shown the clinical semiconductor dosimetry system (CSDS) MOSFET provides stable dose measurements with temperatures varying from 15 deg C up to 40 deg C. Thus standard irradiations performed at room temperature can be directly compared to in-vivo dose assessments performed at near body temperature without a temperature correction function. The MOSFET dosimeter threshold voltage varies with temperature and this level is dependant on the dose history of the MOSFET dosimeter. However the variation can be accounted for in the measurement method. For accurate dosimetry the detector should be placed for approximately 60 seconds on a patient to allow thermal equilibrium before measurements are taken with the final reading performed whilst still attached to the patient or conversely left for approximately 120 seconds after removal from the patient if initial readout was measured at room temperature to allow temperature equilibrium to be established. Copyright (2004) Australasian College of Physical Scientists and Engineers in Medicine

  11. Effects of temperature variation on MOSFET dosimetry

    International Nuclear Information System (INIS)

    Cheung Tsang; Butson, Martin J; Yu, Peter K N

    2004-01-01

    This note investigates temperature effects on dosimetry using a metal oxide semiconductor field effect transistor (MOSFET) for radiotherapy x-ray treatment. This was performed by analysing the dose response and threshold voltage outputs for MOSFET dosimeters as a function of ambient temperature. Results have shown that the clinical semiconductor dosimetry system (CSDS) MOSFET provides stable dose measurements with temperatures varying from 15 deg. C up to 40 deg. C. Thus standard irradiations performed at room temperature can be directly compared to in vivo dose assessments performed at near body temperature without a temperature correction function. The MOSFET dosimeter threshold voltage varies with temperature and this level is dependent on the dose history of the MOSFET dosimeter. However, the variation can be accounted for in the measurement method. For accurate dosimetry, the detector should be placed for approximately 60 s on a patient to allow thermal equilibrium before measurements are taken with the final reading performed whilst still attached to the patient or conversely left for approximately 120 s after removal from the patient if initial readout was measured at room temperature to allow temperature equilibrium to be established. (note)

  12. Temperature effects on flocculation, using different coagulants.

    Science.gov (United States)

    Fitzpatrick, C S B; Fradin, E; Gregory, J

    2004-01-01

    Temperature is known to affect flocculation and filter performance. Jar tests have been conducted in the laboratory, using a photometric dispersion analyser (PDA) to assess the effects of temperature on floc formation, breakage and reformation. Alum, ferric sulphate and three polyaluminium chloride (PACI) coagulants have been investigated for temperatures ranging between 6 and 29 degrees C for a suspension of kaolin clay in London tap water. Results confirm that floc formation is slower at lower temperatures for all coagulants. A commercial PACl product, PAX XL 19, produces the largest flocs for all temperatures; and alum the smallest. Increasing the shear rate results in floc breakage in all cases and the flocs never reform to their original size. This effect is most notable for temperatures around 15 degrees C. Breakage, in terms of floc size reduction, is greater for higher temperatures, suggesting a weaker floc. Recovery after increased shear is greater at lower temperatures implying that floc break-up is more reversible for lower temperatures.

  13. The Plutonium Temperature Effect Experimental Program

    Energy Technology Data Exchange (ETDEWEB)

    Haeck, Wim; Leclaire, Nicolas; Letang, Eric [IRSN, Fontenay-aux-Roses (France); Girault, Emmanuel; Fouillaud, Patrick [CEA, VALDUC (France)

    2008-07-01

    Various theoretical studies have shown that highly diluted plutonium solutions could have a positive temperature effect but (up to now) no experimental program has confirmed this effect. The main goal of the French Plutonium Temperature Effect Experimental Program (or PU+ in short) is to effectively show that such a positive temperature effect exists for diluted plutonium solutions. The experiments were conducted in the 'Apparatus B' facility at the CEA Valduc research centre in France and involved several sub-critical approach type of experiments using plutonium nitrate solutions with concentrations of 14.3, 15 and 20 g/l at temperatures ranging from 20 to 40 deg. C. A total number of 14 phase I experiments (consisting of independent subcritical approaches) have been performed (5 at 20 g/l, 4 at 15 g/l and 5 at 14.3 g/l) between 2006 and 2007. The impact of the uncertainties on the solution acidity and the plutonium concentration makes it difficult to clearly demonstrate the positive temperature effect, requiring an additional phase II experiment (in which the use of the same plutonium solution was ensured) from 22 to 28 deg. C performed in July 2007. This experiment has shown the existence of a positive temperature effect approx +2 pcm/deg. C (from 22 to 28 deg. C for a plutonium concentration of 14.3 g/l). (authors)

  14. Variable effects of temperature on insect herbivory

    Directory of Open Access Journals (Sweden)

    Nathan P. Lemoine

    2014-05-01

    Full Text Available Rising temperatures can influence the top-down control of plant biomass by increasing herbivore metabolic demands. Unfortunately, we know relatively little about the effects of temperature on herbivory rates for most insect herbivores in a given community. Evolutionary history, adaptation to local environments, and dietary factors may lead to variable thermal response curves across different species. Here we characterized the effect of temperature on herbivory rates for 21 herbivore-plant pairs, encompassing 14 herbivore and 12 plant species. We show that overall consumption rates increase with temperature between 20 and 30 °C but do not increase further with increasing temperature. However, there is substantial variation in thermal responses among individual herbivore-plant pairs at the highest temperatures. Over one third of the herbivore-plant pairs showed declining consumption rates at high temperatures, while an approximately equal number showed increasing consumption rates. Such variation existed even within herbivore species, as some species exhibited idiosyncratic thermal response curves on different host plants. Thus, rising temperatures, particularly with respect to climate change, may have highly variable effects on plant-herbivore interactions and, ultimately, top-down control of plant biomass.

  15. Effects of temperature increase in insect community

    International Nuclear Information System (INIS)

    Tuda, Midori; Fujii, Koichi

    1993-01-01

    Temperature will rise by 2degC in the near future. Potential effects of the rise on biological community are predicted with little evidence on the subjects. Individualistic responses of component species in community are often ignored. We performed experiments on a lab host-parasitoid community and tested the hypothesis that individualistic changes in developmental schedules by temperature rise can generate drastic community change. (author)

  16. Temperature effects on cathodoluminescence of enstatite

    Science.gov (United States)

    Ohgo, S.; Nishido, H.

    2017-12-01

    Cathodoluminescence (CL) of enstatite has been extensively investigated for planetary science applications. The CL features are affected by many factors of impurities such as transition metal elements, structural defects and sample temperature. However, the temperature effects on enstatite CL have not been clarified so far. In this study, we have quantitatively evaluated temperature effects on enstatite CL. Three samples of luminescent enstatite were employed for CL spectral measurements. Color CL imaging was carried out using a cold-cathode type Luminoscope with a cooled-CCD camera. CL spectroscopy was made by a SEM-CL system, which is comprised of SEM (JEOL: JSM-5410LV) combined with a grating monochromator (OXFORD: Mono CL2). The CL emitted from the sample was collected in the range of 300-800 nm with a photomultiplier tube by a photon counting method at various temperatures from -193-50 degree C. All CL spectra were corrected for total instrumental response. Color CL imaging reveals various CL emissions with red, reddish-purple and bluish-purple in the terrestrial and extraterrestrial enstatite. All of them have two broad emission bands at around 400 nm in a blue region and at around 670 nm in a red region at room and liquid nitrogen temperatures. The spectral peak in a red region is sharpened and enhanced at lower temperature due to reduction of thermal lattice vibration and an increase in luminescent efficiency. CL intensity at around 670 nm of enstatite decreases with an increase in sample temperature up to -110 degree C from -193 degree C, and increases with an increase in sample temperature between -110 and 50 degree C. This behavior is not able to be explained by a temperature quenching theory based on an increase in the probability of non-radiative transition with the rise of temperature. A least-square fitting of the Arrhenius plot by assuming a Mott-Seitz model provides an activation energy of less than 0.01 eV in temperature quenching process from

  17. Elevated temperature effects on concrete properties

    International Nuclear Information System (INIS)

    Grant, P.R.; Gruber, R.S.; Van Katwijk, C.

    1993-08-01

    The design of facilities to process or store radioactive wastes presents many challenging engineering problems. Such facilities must not only provide for safe storage of radioactive wastes but they must also be able to maintain confinement of these materials during and after natural phenomena events. Heat generated by the radioactive decay of the wastes will cause the temperature of the concrete containment structure to increase to a magnitude higher than that found in conventional structures. These elevated temperatures will cause strength-related concrete properties to degrade over time. For concrete temperatures less than 150 degree F, no reduction in strength is taken and the provisions of ACI 349, which states that higher temperatures are allowed if tests are provided to evaluate the reduction in concrete strength properties, apply. Methods proposed in a Pacific Northwest Laboratory (PNL) report, Modeling of Time-Variant Concrete Properties at Elevated Temperatures, can be used to evaluate the effects of elevated temperatures on concrete properties. Using these modified concrete properties the capacity of a concrete structure, subjected to elevated temperatures, to resist natural phenomena hazards can be determined

  18. Effective Tolman temperature induced by trace anomaly

    International Nuclear Information System (INIS)

    Eune, Myungseok; Gim, Yongwan; Kim, Wontae

    2017-01-01

    Despite the finiteness of stress tensor for a scalar field on the four-dimensional Schwarzschild black hole in the Israel-Hartle-Hawking vacuum, the Tolman temperature in thermal equilibrium is certainly divergent on the horizon due to the infinite blue-shift of the Hawking temperature. The origin of this conflict is due to the fact that the conventional Tolman temperature was based on the assumption of a traceless stress tensor, which is, however, incompatible with the presence of the trace anomaly responsible for the Hawking radiation. Here, we present an effective Tolman temperature which is compatible with the presence of the trace anomaly by using the modified Stefan-Boltzmann law. Eventually, the effective Tolman temperature turns out to be finite everywhere outside the horizon, and so an infinite blue-shift of the Hawking temperature at the event horizon does not appear any more. In particular, it is vanishing on the horizon, so that the equivalence principle is exactly recovered at the horizon. (orig.)

  19. Effective Tolman temperature induced by trace anomaly

    Energy Technology Data Exchange (ETDEWEB)

    Eune, Myungseok [Sangmyung University, Department of Civil Engineering, Cheonan (Korea, Republic of); Gim, Yongwan [Sogang University, Department of Physics, Seoul (Korea, Republic of); Sogang University, Research Institute for Basic Science, Seoul (Korea, Republic of); Kim, Wontae [Sogang University, Department of Physics, Seoul (Korea, Republic of)

    2017-04-15

    Despite the finiteness of stress tensor for a scalar field on the four-dimensional Schwarzschild black hole in the Israel-Hartle-Hawking vacuum, the Tolman temperature in thermal equilibrium is certainly divergent on the horizon due to the infinite blue-shift of the Hawking temperature. The origin of this conflict is due to the fact that the conventional Tolman temperature was based on the assumption of a traceless stress tensor, which is, however, incompatible with the presence of the trace anomaly responsible for the Hawking radiation. Here, we present an effective Tolman temperature which is compatible with the presence of the trace anomaly by using the modified Stefan-Boltzmann law. Eventually, the effective Tolman temperature turns out to be finite everywhere outside the horizon, and so an infinite blue-shift of the Hawking temperature at the event horizon does not appear any more. In particular, it is vanishing on the horizon, so that the equivalence principle is exactly recovered at the horizon. (orig.)

  20. Nuclear shell effects at high temperatures

    International Nuclear Information System (INIS)

    Davidson, N.J.; Miller, H.G.

    1993-01-01

    In discussing the disappearance of nuclear shell effects at high temperatures, it is important to distinguish between the ''smearing out'' of the single-particle spectrum with increasing temperature and the vanishing of shell related structures in many-body quantities such as the excitation energy per nucleon. We propose a semiempirical method to obtain an upper bound on the temperature required to smooth the single-particle spectrum, and point out that shell effects in many-body parameters may persist above this temperature. We find that the temperature required to smear out the single-particle spectrum is approximately 1 MeV for heavy nuclei (A approx-gt 150) and about 3--4 MeV for light nuclei (A approx-lt 50), in reasonable agreement with the estimate of 41/πA 1/3 obtained from calculations with harmonic oscillator potentials. These temperatures correspond to many-body excitation energies of approximately 20 and 60 MeV, respectively

  1. Effects of temperature changes on groundwater ecosystems

    Science.gov (United States)

    Griebler, Christian; Kellermann, Claudia; Schreglmann, Kathrin; Lueders, Tillmann; Brielmann, Heike; Schmidt, Susanne; Kuntz, David; Walker-Hertkorn, Simone

    2014-05-01

    The use of groundwater as a carrier of thermal energy is becoming more and more important as a sustainable source of heating and cooling. At the same time, the present understanding of the effects of aquifer thermal usage on geochemical and biological aquifer ecosystem functions is extremely limited. Recently we started to assess the effects of temperature changes in groundwater on the ecological integrity of aquifers. In a field study, we have monitored hydrogeochemical, microbial, and faunal parameters in groundwater of an oligotrophic aquifer in the vicinity of an active thermal discharge facility. The observed seasonal variability of abiotic and biotic parameters between wells was considerable. Yet, due to the energy-limited conditions no significant temperature impacts on bacterial or faunal abundances and on bacterial productivity were observed. In contrast, the diversity of aquifer bacterial communities and invertebrate fauna was either positively or negatively affected by temperature, respectively. In follow-up laboratory experiments temperature effects were systematically evaluated with respect to energy limitation (e.g. establishment of unlimited growth conditions), geochemistry (e.g. dynamics of DOC and nutrients), microbiology (e.g. survival of pathogens), and fauna (temperature preference and tolerance). First, with increased nutrient and organic carbon concentrations even small temperature changes revealed microbiological dynamics. Second, considerable amounts of adsorbed DOC were mobilized from sediments of different origin with an increase in temperatures. No evidence was obtained for growth of pathogenic bacteria and extended survival of viruses at elevated temperatures. Invertebrates clearly preferred natural thermal conditions (10-12°C), where their highest frequency of appearance was measured in a temperature gradient. Short-term incubations (48h) of invertebrates in temperature dose-response tests resulted in LT50 (lethal temperature) values

  2. Discrete breathers in graphane: Effect of temperature

    Energy Technology Data Exchange (ETDEWEB)

    Baimova, J. A., E-mail: julia.a.baimova@gmail.com [Russian Academy of Sciences, Institute of Metal Physics, Ural Branch (Russian Federation); Murzaev, R. T.; Lobzenko, I. P.; Dmitriev, S. V. [Russian Academy of Sciences, Institute for Metals Superplasticity Problems (Russian Federation); Zhou, Kun [Nanyang Technological University, School of Mechanical and Aerospace Engineering (Singapore)

    2016-05-15

    The discrete breathers in graphane in thermodynamic equilibrium in the temperature range 50–600 K are studied by molecular dynamics simulation. A discrete breather is a hydrogen atom vibrating along the normal to a sheet of graphane at a high amplitude. As was found earlier, the lifetime of a discrete breather at zero temperature corresponds to several tens of thousands of vibrations. The effect of temperature on the decay time of discrete breathers and the probability of their detachment from a sheet of graphane are studied in this work. It is shown that closely spaced breathers can exchange energy with each other at zero temperature. The data obtained suggest that thermally activated discrete breathers can be involved in the dehydrogenation of graphane, which is important for hydrogen energetics.

  3. Effects of chilling temperatures on photosynthesis

    Science.gov (United States)

    Environmental stress is an inescapable reality for most plants growing in natural settings. Conditions of sub or supra-optimal temperatures, water deficit, water logging, salinity, and pollution can have dramatic effects on plant growth and development, and in agricultural settings, yield. In cotton...

  4. SUPPLEMENTARY INFORMATION Temperature effects on the ...

    Indian Academy of Sciences (India)

    Windows User

    SUPPLEMENTARY INFORMATION. Temperature effects on the hydrophobic force between two graphene-like surfaces in liquid water. TUHIN SAMANTA and BIMAN BAGCHI. Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore, Karnataka 560. 012, India. Table of Contents. Figure S1. Page 2.

  5. Effect of programmed circadian temperature fluctuations on ...

    African Journals Online (AJOL)

    to our knowledge of the effects of temperature on the population dynamics of freshwater snails and its bearing on their .... 28"C regime as reflected by the net reproduction rate recorded in Table 1. It was demonstrated by De Kock & .... ANDREW ARlHA, H.G. & BIRCH, L.C. 1954. The distribution and abundance of animals.

  6. Temperature standards, what and where: resources for effective temperature measurements

    International Nuclear Information System (INIS)

    Johnston, W.W. Jr.

    1982-01-01

    Many standards have been published to describe devices, methods, and other topics. How they are developed and by whom are briefly described, and an attempt is made to extract most of those relating to temperature measurements. A directory of temperature standards and their sources is provided

  7. Temperature effect on surface oxidation of titanium

    International Nuclear Information System (INIS)

    Vaquilla, I.; Barco, J.L. del; Ferron, J.

    1990-01-01

    The effect of temperature on the first stages of the superficial oxidation of polycrystalline titanium was studied using both Auger electron spectroscopy (AES) and emission shreshold (AEAPS). The number of compounds present on the surface was determined by application of the factor analysis technique. Reaction evolution was followed through the relative variation of Auger LMM and LMV transitions which are characteristic of titanium. Also the evolution of the chemical shift was determined by AEAPS. The amount of oxygen on the surface was quantified using transition KLL of oxygen. It was found that superficial oxidation depends on temperature. As much as three different compounds were determined according to substrate temperature and our exposure ranges. (Author). 7 refs., 5 figs

  8. Effective temperature in relaxation of Coulomb glasses.

    Science.gov (United States)

    Somoza, A M; Ortuño, M; Caravaca, M; Pollak, M

    2008-08-01

    We study relaxation in two-dimensional Coulomb glasses up to macroscopic times. We use a kinetic Monte Carlo algorithm especially designed to escape efficiently from deep valleys around metastable states. We find that, during the relaxation process, the site occupancy follows a Fermi-Dirac distribution with an effective temperature much higher than the real temperature T. Long electron-hole excitations are characterized by T(eff), while short ones are thermalized at T. We argue that the density of states at the Fermi level is proportional to T(eff) and is a good thermometer to measure it. T(eff) decreases extremely slowly, roughly as the inverse of the logarithm of time, and it should affect hopping conductance in many experimental circumstances.

  9. Processing temperature effects on molybdenum disilicide

    International Nuclear Information System (INIS)

    Wade, R.K.; Petrovic, J.J.

    1992-01-01

    This paper reports on a series of MoSi 2 compacts that were fabricated at increasing hot-pressing temperatures to achieve different grain sizes. The materials were evaluated by Vickers indentation fracture to determine room-temperature fracture toughness, hardness, and fracture mode. From 1500 degrees to 1800 degrees C, MoSi 2 had a constant 67% transgranular fracture and linearly increasing rain size from 14 to 21 μm. Above 1800 degrees C, the fracture percentage increased rapidly to 97% transgranular at 1920 degrees C (32 μ grain size). Fracture toughness and hardness decreased slightly with increasing temperature. MoSi 2 processed at 1600 degrees C had the highest fracture toughness and hardness values of 3.6 MPa·m 1/2 and 9.9 GPa, respectively. The effects of SiO 2 formation from oxygen impurities in the MoSi 2 starting powders and MoSi 2 -Mo 5 Si 3 eutectic liquid formation were studied

  10. Nickel brittling by hydrogen. Temperature effect

    International Nuclear Information System (INIS)

    Lapitz, P.A; Fernandez, S; Alvarez, M.G

    2006-01-01

    The results of a study on the effect of different variables on the susceptibility to brittling by hydrogen and the velocity of propagation of fissures in nickel wire (99.7% purity) are described. The hydrogen load was carried out by cathodic polarization in H 2 SO 4 0.5m solution. The susceptibility to brittling by hydrogen was determined with traction tests at slow deformation speed and constant cathodic potential, and the later observation of the fracture surface by scanning electron microscopy. The variables studied were: applied cathodic overpower, speed of initial deformation and temperature. The results showed that the speed of fissure propagation in the nickel by brittleness from hydrogen is a function of the applied potential and the speed of deformation used. Without tension, the hydrogen load by cathodic polarization at room temperature leads to the formation of cavities similar to those observed when the hydrogenation is performed in the presence of gaseous hydrogen at high pressure and temperature (CW)

  11. The sublethal effects of zinc at different water temperatures on ...

    African Journals Online (AJOL)

    The sublethal effects of zinc at different water temperatures on selected ... of 96h at different water temperatures representing the seasonal temperatures in the ... are mobilised to meet increased energy demands during periods of stress.

  12. Effect of temperature on sandstone permeability

    DEFF Research Database (Denmark)

    Rosenbrand, Esther; Kjøller, Claus

    Hot water injection in geothermal sandstone aquifers is considered for seasonal energy storage in Denmark. However, an increase in the aquifer temperature might reduce permeability, and thereby increase production costs. An understanding of the factors that control permeability is required in order...... and the Klinkenberg procedure showed the expected correlation between the two measures, however, differences could be around one order of magnitude. In tight gas sandstones, permeability is often sensitive to net stress, which might change due to the pore pressure change in the Klinkenberg procedure. Besides...... affecting the Klinkenberg procedure, the combined effect of slip and changes in permeability would affect production during pressure depletion in tight gas sandstone reservoirs; therefore effects of gas slip and net stress on permeability were combined in a model based on the Klinkenberg equation. A lower...

  13. Effect of microstructure on the high temperature strength of nitride

    Indian Academy of Sciences (India)

    Effect of microstructure on the high temperature strength of nitride bonded silicon carbide composite. J Rakshit P K Das. Composites Volume ... The effect of these parameters on room temperature and high temperature strength of the composite up to 1300°C in ambient condition were studied. The high temperature flexural ...

  14. Managing Temperature Effects in Nanoscale Adaptive Systems

    CERN Document Server

    Wolpert, David

    2012-01-01

    This book discusses new techniques for detecting, controlling, and exploiting the impacts of temperature variations on nanoscale circuits and systems.  It provides a holistic discussion of temperature management, including physical phenomena (reversal of the MOSFET temperature dependence) that have recently become problematic, along with circuit techniques for detecting, controlling, and adapting to these phenomena. A detailed discussion is also included of the general aspects of thermal-aware system design and management of temperature-induced faults. A new sensor system is described that can determine the temperature dependence as well as the operating temperature to improve system reliability.  A new method is presented to control a circuit’s temperature dependence by individually tuning pull-up and pull-down networks to their temperature-insensitive operating points. This method extends the range of supply voltages that can be made temperature-insensitive, achieving insensitivity at nominal voltage fo...

  15. Room Temperature Silicene Field-Effect Transistors

    Science.gov (United States)

    Akinwande, Deji

    Silicene, a buckled Si analogue of graphene, holds significant promise for future electronics beyond traditional CMOS. In our predefined experiments via encapsulated delamination with native electrodes approach, silicene devices exhibit an ambipolar charge transport behavior, corroborating theories on Dirac band in Ag-free silicene. Monolayer silicene device has extracted field-effect mobility within the theoretical expectation and ON/OFF ratio greater than monolayer graphene, while multilayer silicene devices show decreased mobility and gate modulation. Air-stability of silicene devices depends on the number of layers of silicene and intrinsic material structure determined by growth temperature. Few or multi-layer silicene devices maintain their ambipolar behavior for days in contrast to minutes time scale for monolayer counterparts under similar conditions. Multilayer silicene grown at different temperatures below 300oC possess different intrinsic structures and yield different electrical property and air-stability. This work suggests a practical prospect to enable more air-stable silicene devices with layer and growth condition control, which can be leveraged for other air-sensitive 2D materials. In addition, we describe quantum and classical transistor device concepts based on silicene and related buckled materials that exploit the 2D topological insulating phenomenon. The transistor device physics offer the potential for ballistic transport that is robust against scattering and can be employed for both charge and spin transport. This work was supported by the ARO.

  16. Combined scale effects for effective brazing at low temperatures

    Directory of Open Access Journals (Sweden)

    Bartout D.

    2012-12-01

    Full Text Available In modern joining technology, the focus is on effective brazing and soldering of temperature sensitive materials. Here, as well as in diffusion welding processes the needed thermal energy is externally realized in the joint zone. This produces a heating of the whole joining parts, since in laminar joining the thermal energy is transported in interior by thermal conduction. An excess of critical temperatures or tolerable impact periods in wide parts of materials and respectively components is often not avoidable. This leads to thermal damages. In this point of view nanotechnology shows promising possibilities as scale effects and their resulting thermophysical effects such as melting temperature reduction and high diffusion rates can be used for providing a self-propagating high-temperature synthesis at room temperature. After ignition by an external energy source a self-propagating exothermic reaction is started. By producing a multilayer system with alternately arranged nanoscaled layers of e.g. Al and Ni the resulting thin foil can be used as heat source for melting the braze or solder material within the joining zone without any external preheating. Due to the high process velocities up to 30 m/s and the local heat input significant thermal influences on the joined parts are not detectable.

  17. Temperature dependence of radiation effects in polyethylene

    International Nuclear Information System (INIS)

    Wu, G; Katsumura, Y.; Kudoh, H.; Morita, Y.; Seguchi, T.

    2000-01-01

    Temperature dependence of crosslinking and gas evolution under γ-irradiation was studied for high-density and low-density polyethylene samples in the 30-360degC range. It was found that crosslinking was the predominant process up to 300degC and the gel point decreased with increasing temperature. At above 300degC, however, the gel fraction at a given dose decreased rapidly with temperature and the action of radiation turned to enhance polyethylene degradation. Yields of H 2 and hydrocarbon gases increased with temperature and the compositions of hydrocarbons were dose dependent. (author)

  18. Effective temperature in driven vortex lattices with random pinning

    International Nuclear Information System (INIS)

    Kolton, Alejandro B.; Dominguez, Daniel; Exartier, Raphael; Cugliandolo, Leticia F.; Groenbech-Jensen, N.

    2003-09-01

    We study numerically correlation and response functions in non-equilibrium driven vortex lattices with random pinning. From a generalized fluctuation-dissipation relation we calculate an effective transverse temperature in the fluid moving phase. We find that the effective temperature decreases with increasing driving force and becomes equal to the equilibrium melting temperature when the dynamic transverse freezing occurs. We also discuss how the effective temperature can be measured experimentally from a generalized Kubo formula. (author)

  19. Magnetic memory effects in high temperature superconductors

    International Nuclear Information System (INIS)

    Rockenbauer, A.

    1989-01-01

    Microwave absorption of high temperature oxide superconductors MBa 2 Cu 3 O 7 (M = Y, Er, Dy, Ho, Lu, Tm, Gd) at 77 K have been studied by ESR. In granular samples diamagnetic zero-field resonance and strong ESR baseline hysteresis have been observed: for increasing field sweep - a high, for decreasing one - a low, while in constant field the baseline approaches the middle position with kinetics typical of spin-glasses. The hysteresis amplitude, i.e. the deviation of high and low baselines, possesses maximum at zero field if the sample is cooled down in zero field. In case of field cooling both the diamagnetic resonance and hysteresis maximum are shifted as a function of relative direction of the fields where the samples are cooled and measured, respectively. The shift is caused by the remanent diamagnetism of trapped fluxons. The hysteresis critically depends on the modulation amplitude of magnetic field, and no hysteresis can be observed if the microwave absorption is detected without field modulation. By applying saw-tooth sweep the spin-glass can be driven between two extreme hysteresis states, and the ESR response is rectangular for large saw-tooth amplitude and linear - for small one, while for intermediate amplitudes the recording shows characteristic memory effects. The hysteresis memory is explained in terms of loop distribution of fluxons. In the single crystal the fluxon absorptions are also detected and the separation of fluxon lines can be related to the hysteresis in granular samples. (author)

  20. Effect of processor temperature on film dosimetry

    International Nuclear Information System (INIS)

    Srivastava, Shiv P.; Das, Indra J.

    2012-01-01

    Optical density (OD) of a radiographic film plays an important role in radiation dosimetry, which depends on various parameters, including beam energy, depth, field size, film batch, dose, dose rate, air film interface, postexposure processing time, and temperature of the processor. Most of these parameters have been studied for Kodak XV and extended dose range (EDR) films used in radiation oncology. There is very limited information on processor temperature, which is investigated in this study. Multiple XV and EDR films were exposed in the reference condition (d max. , 10 × 10 cm 2 , 100 cm) to a given dose. An automatic film processor (X-Omat 5000) was used for processing films. The temperature of the processor was adjusted manually with increasing temperature. At each temperature, a set of films was processed to evaluate OD at a given dose. For both films, OD is a linear function of processor temperature in the range of 29.4–40.6°C (85–105°F) for various dose ranges. The changes in processor temperature are directly related to the dose by a quadratic function. A simple linear equation is provided for the changes in OD vs. processor temperature, which could be used for correcting dose in radiation dosimetry when film is used.

  1. Temperature has a causal effect on avian timing of reproduction

    NARCIS (Netherlands)

    Visser, M.E.; Holleman, L.J.M.; Caro, S.P.

    2009-01-01

    Many bird species reproduce earlier in years with high spring temperatures, but little is known about the causal effect of temperature. Temperature may have a direct effect on timing of reproduction but the correlation may also be indirect, for instance via food phenology. As climate change has led

  2. Temperature effects on waste glass performance

    International Nuclear Information System (INIS)

    Mazer, J.J.

    1991-02-01

    The temperature dependence of glass durability, particularly that of nuclear waste glasses, is assessed by reviewing past studies. The reaction mechanism for glass dissolution in water is complex and involves multiple simultaneous reaction proceeded, including molecular water diffusion, ion exchange, surface reaction, and precipitation. These processes can change in relative importance or dominance with time or changes in temperature. The temperature dependence of each reaction process has been shown to follow an Arrhenius relationship in studies where the reaction process has been isolated, but the overall temperature dependence for nuclear waste glass reaction mechanisms is less well understood, Nuclear waste glass studies have often neglected to identify and characterize the reaction mechanism because of difficulties in performing microanalyses; thus, it is unclear if such results can be extrapolated to other temperatures or reaction times. Recent developments in analytical capabilities suggest that investigations of nuclear waste glass reactions with water can lead to better understandings of their reaction mechanisms and their temperature dependences. Until a better understanding of glass reaction mechanisms is available, caution should be exercised in using temperature as an accelerating parameter. 76 refs., 1 tab

  3. Effects of cryogenic irradiation on temperature sensors

    International Nuclear Information System (INIS)

    Courts, S.S.; Holmes, D.S.

    1996-01-01

    Several types of commercially available cryogenic temperature sensors were calibrated, irradiated at 4.2 K by a gamma or neutron source, and recalibrated in-situ to determine their suitability for thermometry in radiation environments. Comparisons were made between pre- and post-irradiation calibrations with the equivalent temperature shift calculated for each sensor at various temperature in the 4.2 K to 330 K range. Four post-irradiation calibrations were performed with annealing steps performed at 20 K, 80 K, and 330 K. Temperature sensors which were gamma irradiated were given a total dose of 10,000 Gy. Temperature sensors which were neutron irradiated were irradiated to a total fluence of 2 x 10 12 n/cm 2 . In general, for gamma radiation environments, diodes are unsuitable for use. Both carbon glass and germanium resistance sensors performed well at lower temperature, while platinum resistance sensors performed best above 30 K. Thin-film rhodium and Cernox trademark resistance sensors both performed well over the 4.2 K to 330 K range. Only thin-film rhodium and Cernox trademark resistance temperature sensors were neutron irradiated and they both performed well over the 4.2 K to 330 K range

  4. Memory effect in the high-temperature superconducting bulks

    International Nuclear Information System (INIS)

    Zhang, Xing-Yi; Zhou, Jun; Zhou, You-He

    2013-01-01

    Highlights: •Effects of temperature cycles on levitation force relaxation are investigated. •Memory effect of the YBCO bulks is observed in experiments. •With an increase of temperature, memory of the superconductor is gradually lost. -- Abstract: We present an experimental investigation of the relaxation of vertical force components in a high-temperature superconducting levitation system with different temperature cycle processes. For a selected ambient temperature (T 1 ) of the system, the experimental results show that the relaxations of the levitation forces are strongly dependent on the initial temperature. When the sample was submitted to temperature jumps around T 1 , the sample temperature was regulated at T 2 , and there were two cases of the experiments, ΔT = T 2 − T 1 0 (positive temperature cycle). It was found that in the case of negative temperature cycle, the superconducting samples have memory effect. And for the positive temperature cycle, with the experimental temperature increase, the memory effect of samples is gradually losing. Additionally, with the increase of temperature, the influences of the negative and positive temperature cycle on the levitation force relaxation are unsymmetrical. All the results are interpreted by using the characteristics of the free energy ‘ground’ plot of the Spin-glasses qualitatively

  5. EFFECTS OF ELEVATED TEMPERATURE ON ELEVATED ...

    African Journals Online (AJOL)

    eobe

    various temperature regimes before testing. A concrete mix of 1:1:3 ... approach arising from statistical evidence is not out of place. ... This paper presents the results of concrete cubes tests ..... accelerated there by reducing the strength of the.

  6. Finite temperature effects in primordial inflation

    Science.gov (United States)

    Gelmini, G. B.; Nanopoulos, D. V.; Olive, K. A.

    1983-11-01

    We present a detailed study of a recently proposed model for primordial inflation based on an N=1 locally supersymmetric potential. For a large class of parameters with which all cosmological constraints are satisfied, the temperature corrections can be neglected during the inflation period. At higher temperatures, the minimum is not at the origin, but very close to it. Address after July 1, 1983: Theory Group, Fermilab, PO Box 500, Batavia, IL 60510, USA.

  7. Effects of air temperature and discharge on Upper Mississippi River summer water temperatures

    Science.gov (United States)

    Gray, Brian R.; Robertson, Dale M.; Rogala, James T.

    2018-01-01

    Recent interest in the potential effects of climate change has prompted studies of air temperature and precipitation associations with water temperatures in rivers and streams. We examined associations between summer surface water temperatures and both air temperature and discharge for 5 reaches of the Upper Mississippi River during 1994–2011. Water–air temperature associations at a given reach approximated 1:1 when estimated under an assumption of reach independence but declined to approximately 1:2 when water temperatures were permitted to covary among reaches and were also adjusted for upstream air temperatures. Estimated water temperature–discharge associations were weak. An apparently novel feature of this study is that of addressing changes in associations between water and air temperatures when both are correlated among reaches.

  8. Effects of open-air temperature on air temperature inside biological safety cabinet.

    Science.gov (United States)

    Umemura, Masayuki; Shigeno, Katsuro; Yamamura, Keiko; Osada, Takashi; Soda, Midori; Yamada, Kiyofumi; Ando, Yuichi; Wakiya, Yoshifumi

    2011-02-14

    In Japan, biological safety cabinets (BSCs) are normally used by medical staff while handling antineoplastic agents. We have also set up a class II B2 BSC at the Division of Chemotherapy for Outpatients. The air temperature inside this BSC, however, decreases in winter. We assumed that this decrease is caused by the intake of open-air. Therefore, we investigated the effects of low open-air temperature on the BSC temperature and the time of admixtures of antineoplastic agents. The studies were conducted from January 1 to March 31, 2008. The outdoor air temperature was measured in the shade near the intake nozzle of the BSC and was compared with the BSC temperature. The correlation between the outdoor air temperature and the BSC temperature, the dissolution time of cyclophosphamide (CPA) and gemcitabine (GEM), and accurate weight measurement of epirubicin (EPI) solution were investigated for low and normal BSC temperatures. The BSC temperature was correlated with the open-air temperature for open-air temperatures of 5-20°C (p air is drawn from outdoors. We showed that the BSC temperature affects the dissolution rate of antineoplastic agents. Further, we suggested that the BSC temperature drop might delay the affair of the admixtures of antineoplastic agents and increase the waiting time of outpatients for chemotherapy.

  9. Temperature effects on the Davydov soliton

    DEFF Research Database (Denmark)

    Cruzeiro, L.; Halding, J.; Christiansen, Peter Leth

    1988-01-01

    As a possible mechanism for energy storage and transport in proteins, Davydov has proposed soliton formation and propagation. In this paper we investigate the stability of Davydov solitons at biological temperatures. From Davydov’s original theory evolution equations are derived quantum mechanica......As a possible mechanism for energy storage and transport in proteins, Davydov has proposed soliton formation and propagation. In this paper we investigate the stability of Davydov solitons at biological temperatures. From Davydov’s original theory evolution equations are derived quantum...

  10. Temperature extremes: Effect on plant growth and development

    Directory of Open Access Journals (Sweden)

    Jerry L. Hatfield

    2015-12-01

    Full Text Available Temperature is a primary factor affecting the rate of plant development. Warmer temperatures expected with climate change and the potential for more extreme temperature events will impact plant productivity. Pollination is one of the most sensitive phenological stages to temperature extremes across all species and during this developmental stage temperature extremes would greatly affect production. Few adaptation strategies are available to cope with temperature extremes at this developmental stage other than to select for plants which shed pollen during the cooler periods of the day or are indeterminate so flowering occurs over a longer period of the growing season. In controlled environment studies, warm temperatures increased the rate of phenological development; however, there was no effect on leaf area or vegetative biomass compared to normal temperatures. The major impact of warmer temperatures was during the reproductive stage of development and in all cases grain yield in maize was significantly reduced by as much as 80−90% from a normal temperature regime. Temperature effects are increased by water deficits and excess soil water demonstrating that understanding the interaction of temperature and water will be needed to develop more effective adaptation strategies to offset the impacts of greater temperature extreme events associated with a changing climate.

  11. The measurement of temperature effect of light output of scintillators

    International Nuclear Information System (INIS)

    Ji Changsong; Zhou Zaiping; Zhang Longfang

    1999-01-01

    The author describes a experiment equipment used for measurement of temperature effect of light output of scintillators; gives some measurement results of temperature effect of light output for NaI(Tl), CsI(Tl), plastic scintillator, ZnS(Ag), anthracene crystal glass scintillator; analyzes the error factors affecting the measurement results. The total uncertainty of the temperature effect measurement for NaI(Tl) and plastic scintillator is 11%

  12. Effects of Elevated Temperature on Compressive Strength Of Concrete

    African Journals Online (AJOL)

    This study presents the results of investigation of the effects of elevated temperatures on the compressive strength of Grade 40 concrete. A total of thirty cube specimens were cast, cured in water at ambient temperature in the laboratory and subjected to various temperature regimes before testing. A concrete mix of 1:1:3 ...

  13. Le Chatelier's Principle, Temperature Effects, and Entropy.

    Science.gov (United States)

    Campbell, J. Arthur

    1985-01-01

    One of the most useful methods of understanding chemical equilibria is provided by Le Chatelier's principle. The relationships between this principle, temperature, and entropy are discussed. Tables with thermodynamic data for some net reactions commonly used to illustrate the principle and for reactions involving gases are included. (JN)

  14. Enhanced battery model including temperature effects

    NARCIS (Netherlands)

    Rosca, B.; Wilkins, S.

    2013-01-01

    Within electric and hybrid vehicles, batteries are used to provide/buffer the energy required for driving. However, battery performance varies throughout the temperature range specific to automotive applications, and as such, models that describe this behaviour are required. This paper presents a

  15. TEMPERATURE EFFECT OF ELECTRICAL PROPERTIES OF CIGS ...

    African Journals Online (AJOL)

    2011-06-30

    Jun 30, 2011 ... Key words: Thin film solar cells, SCAPS, CIGS, temperature, effiency energetic. 1. INTRODUCTION ... technology are the low material consumption and the high efficiency that has been demonstrated, which .... [2] S. Wenham, M. Green, M. Watt, Applied Photovoltaics, The University of New. South Wales ...

  16. Quantitative Temperature Dependence of Longitudinal Spin Seebeck Effect at High Temperatures

    Directory of Open Access Journals (Sweden)

    Ken-ichi Uchida

    2014-11-01

    Full Text Available We report temperature-dependent measurements of longitudinal spin Seebeck effects (LSSEs in Pt/Y_{3}Fe_{5}O_{12} (YIG/Pt systems in a high temperature range from room temperature to above the Curie temperature of YIG. The experimental results show that the magnitude of the LSSE voltage in the Pt/YIG/Pt systems rapidly decreases with increasing the temperature and disappears above the Curie temperature. The critical exponent of the LSSE voltage in the Pt/YIG/Pt systems at the Curie temperature is estimated to be 3, which is much greater than that for the magnetization curve of YIG. This difference highlights the fact that the mechanism of the LSSE cannot be explained in terms of simple static magnetic properties in YIG.

  17. Effective model for deconfinement at high temperature

    International Nuclear Information System (INIS)

    Skokov, Vladimir

    2013-01-01

    In this talk I consider the deconfining phase transition at nonzero temperature in a SU(N) gauge theory, using a matrix model. I present some results including the position of the deconfining critical endpoint, where the first order transition for deconfinement is washed out by the presence of massive, dynamical quarks, and properites of the phase transition in the limit of large N. I show that the model is soluble at infinite N, and exhibits a Gross-Witten-Wadia transition

  18. High Pressure and Temperature Effects in Polymers

    Science.gov (United States)

    Bucknall, David; Arrighi, Valeria; Johnston, Kim; Condie, Iain

    Elastomers are widely exploited as the basis for seals in gas and fluid pipelines. The underlying behaviour of these elastomer at the high pressure, elevated temperatures they experience in operation is poorly understood. Consequently, the duty cycle of these materials is often deliberately limited to a few hours, and in order to prevent failure, production is stopped in order to change the seals in critical joints. The result is significant time lost due to bringing down production to change the seals as well as knock on financial costs. In order to address the fundamental nature of the elastomers at their intended operating conditions, we are studying the gas permeation behaviour of hydrogenated natural butyl rubber (HNBR) and fluorinated elastomers (FKM) at a high pressure and elevated temperature. We have developed a pressure system that permits gas permeation studies at gas pressures of up to 5000 psi and operating temperatures up to 150° C. In this paper, we will discuss the nature of the permeation behaviour at these extreme operating conditions, and how this relates to the changes in the polymer structure. We will also discuss the use of graphene-polymer thin layer coatings to modify the gas permeation behaviour of the elastomers.

  19. Effect of temperature and temperature fluctuation on thermophilic anaerobic digestion of cattle manure

    NARCIS (Netherlands)

    Mashad, El H.; Zeeman, G.; Loon, van W.K.P.; Bot, G.P.A.; Lettinga, G.

    2004-01-01

    The influence of temperature, 50 and 60 °C, at hydraulic retention times (HRTs) of 20 and 10 days, on the performance of anaerobic digestion of cow manure has been investigated in completely stirred tank reactors (CSTRs). Furthermore, the effect of both daily downward and daily upward temperature

  20. Effect of Temperature and Relative Humidity on the Growth of ...

    African Journals Online (AJOL)

    The effects of temperature and relative humidity on the growth of Helminthosporium fulvum were investigated. Various temperature regimes of 10oC, 15oC, 20oC, 25oC, 30oC, 35oC and 40¢ªC were used to determine the temperature effect on the growth of H. fulvum. Maximum growth of H. fulvum was obtained at 25¢ªC ...

  1. The effects of temperature on the radiation chemistry of polymers

    International Nuclear Information System (INIS)

    Hill, D.J.T.

    1995-01-01

    The effects of high energy radiation on polymers is dependent on a number of factors. One of the most important factors is the radiolysis temperature. This paper discusses the effects of the α-transition and the other secondary transitions, as well as the ceiling and melting temperatures, on the nature of the radiolysis reactions which occur for a number of polymers. Some implications of changes in the radiation chemistry of polymers with a change in the temperature are also considered. (author)

  2. The Effect of Temperature on Moisture Transport in Concrete.

    Science.gov (United States)

    Wang, Yao; Xi, Yunping

    2017-08-09

    Most concrete structures and buildings are under temperature and moisture variations simultaneously. Thus, the moisture transport in concrete is driven by the moisture gradient as well as the temperature gradient. This paper presents an experimental approach for determining the effect of different temperature gradients on moisture distribution profiles in concrete. The effect of elevated temperatures under isothermal conditions on the moisture transport was also evaluated, and found not to be significant. The non-isothermal tests show that the temperature gradient accelerates the moisture transport in concrete. The part of increased moisture transfer due to the temperature gradient can be quantified by a coupling parameter D HT , which can be determined by the present test data. The test results indicated that D HT is not a constant but increases linearly with the temperature variation. A material model was developed for D HT based on the experimental results obtained in this study.

  3. Effect of Temperature and Hose Genotype on Components of ...

    African Journals Online (AJOL)

    Effect of Temperature and Hose Genotype on Components of Resistance to Groundnut Rust. P Subrahmanyam, PV Subba Rao, PM Reddy, D McDonald. Abstract. The effects of temperature on incubation period, infection frequency, lesion diameter, leaf area damage, pustule rupture, and sporulation were quantified for six ...

  4. 'Vanishing' structural effects of temperature in polymer glasses close to the glass-transition temperature

    International Nuclear Information System (INIS)

    Shantarovich, V.P.; Suzuki, T.; Ito, Y.; Yu, R.S.; Kondo, K.; Yampolskii, Yu. P.; Alentiev, A.Yu.

    2007-01-01

    Positron annihilation lifetime (PAL) measurements were used for observation of structural effects of temperature in polystyrene (PS), super-cross-linked polystyrene networks (CPS), and in polyimides (PI) below and in the vicinity of glass-transition temperature T g . 'Vanishing' of these structural effects in the repeating cycles of the temperature controlled PAL experiments due to the slow relaxation processes in different conditions and details of chemical structure is demonstrated. Obtained results illustrate complex, dependent on thermal history, inhomogeneous character of the glass structure. In fact, structure of some polymer glasses is changing continuously. Calculations of the number density of free volume holes in these conditions are discussed

  5. Effects of molten material temperatures and coolant temperatures on vapor explosion

    Institute of Scientific and Technical Information of China (English)

    LI Tianshu; YANG Yanhua; YUAN Minghao; HU Zhihua

    2007-01-01

    An observable experiment facility for low-temperature molten materials to be dropped into water was set up in this study to investigate the mechanism of the vapor explosion. The effect of the fuel and coolant interaction(FCI) on the vapor explosion during the severe accidents of a fission nuclear reactor has been studied. The experiment results showed that the molten material temperature has an important effect on the vapor explosion behavior and pressure. The increase of the coolant temperature would decrease the pressure of the vapor explosion.

  6. Estimated effects of temperature on secondary organic aerosol concentrations.

    Science.gov (United States)

    Sheehan, P E; Bowman, F M

    2001-06-01

    The temperature-dependence of secondary organic aerosol (SOA) concentrations is explored using an absorptive-partitioning model under a variety of simplified atmospheric conditions. Experimentally determined partitioning parameters for high yield aromatics are used. Variation of vapor pressures with temperature is assumed to be the main source of temperature effects. Known semivolatile products are used to define a modeling range of vaporization enthalpy of 10-25 kcal/mol-1. The effect of diurnal temperature variations on model predictions for various assumed vaporization enthalpies, precursor emission rates, and primary organic concentrations is explored. Results show that temperature is likely to have a significant influence on SOA partitioning and resulting SOA concentrations. A 10 degrees C decrease in temperature is estimated to increase SOA yields by 20-150%, depending on the assumed vaporization enthalpy. In model simulations, high daytime temperatures tend to reduce SOA concentrations by 16-24%, while cooler nighttime temperatures lead to a 22-34% increase, compared to constant temperature conditions. Results suggest that currently available constant temperature partitioning coefficients do not adequately represent atmospheric SOA partitioning behavior. Air quality models neglecting the temperature dependence of partitioning are expected to underpredict peak SOA concentrations as well as mistime their occurrence.

  7. Temperature corrections, supersymmetric effective potentials and inflation

    International Nuclear Information System (INIS)

    Binetruy, P.; Gaillard, M.K.; California Univ., Berkeley

    1985-01-01

    We calculate the one-loop temperature corrections to general potentials in N=1 supergravity, and study the conditions under which a new inflationary scenario is possible. The results are sensitive to the total number N of chiral superfields. For large N, we find that in 'hidden sector' models supersymmetry must be broken at a scale governed by the energy density of the false vacuum: msub(3/2) > or approx. 2√8π μ 2 /Msub(p), where μ approx.= (10 -3 -10 -4 )Msub(p) in typical inflationary scenarios. We also discuss an alternative picture where inflation occurs at the preonic level, before the preon-confining phase transition. (orig.)

  8. Effects of temperature during the irradiation of calcium carbonate

    Energy Technology Data Exchange (ETDEWEB)

    Negron M, A.; Camargo R, C.; Ramos B, S. [UNAM, Instituto de Ciencias Nucleares, Circuito Exterior, Ciudad Universitaria, 04510 Mexico D. F. (Mexico); Gomez V, V. [UNAM, Instituto de Quimica, Ciudad Universitaria, 04510 Mexico D. F. (Mexico); Uribe, R. M., E-mail: negron@nucleares.unam.mx [Kent State University, College of Technology, Kent 44240 Ohio (United States)

    2015-10-15

    The gamma irradiation of calcium carbonate at different doses (0 to 309 kGy) and temperature regimes (77 K to 298 K) was carried out to study the effects of irradiation temperature. The changes were followed by EPR spectroscopy. We observed the formation of a composite EPR spectrum even at low radiation doses and temperature. There is a strong effect on the evaluation of the radicals formed as a function of irradiation temperature, probably due to the diffusion in the frozen powder. Response curves show that this system tends to saturate at 10 MGy at 298 K. (Author)

  9. Effects of temperature during the irradiation of calcium carbonate

    International Nuclear Information System (INIS)

    Negron M, A.; Camargo R, C.; Ramos B, S.; Gomez V, V.; Uribe, R. M.

    2015-10-01

    The gamma irradiation of calcium carbonate at different doses (0 to 309 kGy) and temperature regimes (77 K to 298 K) was carried out to study the effects of irradiation temperature. The changes were followed by EPR spectroscopy. We observed the formation of a composite EPR spectrum even at low radiation doses and temperature. There is a strong effect on the evaluation of the radicals formed as a function of irradiation temperature, probably due to the diffusion in the frozen powder. Response curves show that this system tends to saturate at 10 MGy at 298 K. (Author)

  10. Percolation temperature and the 'instability' of the effective potential

    International Nuclear Information System (INIS)

    Carvalho, C.A. de; Bazeia Filho, D.; Eboli, O.J.P.; Marques, G.C.; Silva, A.J. da; Ventura, I.

    1984-01-01

    It is shown that in spontaneously broken lambda phi 4 theory the percolation temperature coincides with the temperature at which the semiclassical (loop) expansion of the effective potential (free energy) of the system around a uniform field configuration fails. This allows us to extract the percolation temperature directly from the effective potential. The addition of fermions or gauge fields does not alter the result as long as they are weakly coupled to the scalars. The coincidence holds in the high temperature limit at every order in the loop expansion. (Author) [pt

  11. Effect of temperature and temperature fluctuation on thermophilic anaerobic digestion of cattle manure.

    Science.gov (United States)

    El-Mashad, Hamed M; Zeeman, Grietje; van Loon, Wilko K P; Bot, Gerard P A; Lettinga, Gatze

    2004-11-01

    The influence of temperature, 50 and 60 degrees C, at hydraulic retention times (HRTs) of 20 and 10 days, on the performance of anaerobic digestion of cow manure has been investigated in completely stirred tank reactors (CSTRs). Furthermore, the effect of both daily downward and daily upward temperature fluctuations has been studied. In the daily downward temperature fluctuation regime the temperatures of each reactor was reduced by 10 degrees C for 10 h while in the daily upward fluctuation regime the temperature of each reactor was increased 10 degrees C for 5 h. The results show that the methane production rate at 60 degrees C is lower than that at 50 degrees C at all experimental conditions of imposed HRT except when downward temperature fluctuations were applied at an HRT of 10 days. It also was found that the free ammonia concentration not only affects the acetate-utilising bacteria but also the hydrolysis and acidification process. The upward temperature fluctuation affects the maximum specific methanogenesis activity more severely as compared to imposed downward temperature fluctuations. The results clearly reveal the possibility of using available solar energy at daytime to heat up the reactor(s) without the need of heat storage during nights, especially at an operational temperature of 50 degrees C and at a 20 days HRT, and without the jeopardising of the overheating.

  12. Effect of temperature and temperature fluctuation on thermophilic anaerobic digestion of cattle manure

    Energy Technology Data Exchange (ETDEWEB)

    El-Mashad, H.M. [Mansoura University, El-Mansoura (Egypt). Faculty of Agriculture, Department of Agricultural Engineering; Zeeman, G.; Van Loon, W.K.P.; Bot, G.P.A.; Lettinga, G. [Wageningen University Agrotechnion (Netherlands). Department of Agrotechnology and Food Sciences

    2004-11-01

    The influence of temperature, 50 and 60 {sup o}C, at hydraulic retention times (HRTs) of 20 and 10 days, on the performance of anaerobic digestion of cow manure has been investigated in completely stirred tank reactors (CSTRs). Furthermore, the effect of both daily downward and daily upward temperature fluctuations has been studied. In the daily downward temperature fluctuation regime the temperatures of each reactor was reduced by 10 {sup o}C for 10 h while in the daily upward fluctuation regime the temperature of each reactor was increased 10 {sup o}C for 5 h. The results show that the methane production rate at 60 {sup o}C is lower than that at 50 {sup o}C at all experimental conditions of imposed HRT except when downward temperature fluctuations were applied at an HRT of 10 days. It also was found that the free ammonia concentration not only affects the acetate-utilising bacteria but also the hydrolysis and acidification process. The upward temperature fluctuation affects the maximum specific methanogenesis activity more severely as compared to imposed downward temperature fluctuations. The results clearly reveal the possibility of using available solar energy at daytime to heat up the reactor(s) without the need of heat storage during nights, especially at an operational temperature of 50 {sup o}C and at a 20 days HRT, and without the jeopardising of the overheating. (author)

  13. Temperature, humidity and time. Combined effects on radiochromic film dosimeters

    DEFF Research Database (Denmark)

    Abdel-Fattah, A.A.; Miller, A.

    1996-01-01

    The effects of both relative humidity and temperature during irradiation on the dose response of FWT-60-00 and Riso B3 radiochromic film dosimeters have been investigated in the relative humidity (RH) range 11-94% and temperature range 20-60 degrees C for irradiation by Co-60 photons and 10-Me......V electrons. The results show that humidity and temperature cannot be treated as independent variables, rather there appears to be interdependence between absorbed dose, temperature, and humidity. Dose rate does not seem to play a significant role. The dependence of temperature during irradiation is +0.......25 +/- 0.1% per degrees C for the FWT-60-00 dosimeters and +0.5 +/- 0.1% per degrees C For Riso B3 dosimeters at temperatures between 20 and 50 degrees C and at relative humidities between 20 and 53%. At extreme conditions both with respect to temperature and to humidity, the dosimeters show much stronger...

  14. Effect of temperature on the mechanical properties of polymer mortars

    Directory of Open Access Journals (Sweden)

    João Marciano Laredo dos Reis

    2012-08-01

    Full Text Available This paper presents the results of an experimental program to investigate the effect of temperature on the performance of epoxy and unsaturated polyester polymer mortars (PM. PM is a composite material in which polymeric materials are used to bond the aggregates in a fashion similar to that used in the preparation of Portland cement concrete. For this purpose, prismatic and cylindrical specimens were prepared for flexural and compressive tests, respectively, at different temperatures. Measurements of the temperature-dependent elastic modulus and the compressive and flexural strength were conducted using a thermostatic chamber attached to a universal test machine for a range of temperatures varying from room temperature to 90 ºC. The flexural and compressive strength decreases as temperature increases, especially after matrix HDT. Epoxy polymer mortars are more sensitive to temperature variation than unsaturated polyester ones.

  15. Effect of temperature increments in septic tank efficiency

    International Nuclear Information System (INIS)

    Chi-Tec, M.; Caballero-Arzapalo, N.; Giacoman Vallejo, G.; Mendez-Novelo, R.; Quintal-Franco, C.

    2009-01-01

    Septic tanks are the main sewage disposal system used in Yucatan, Mexico. Septic tank content is stabilized under anaerobic conditions and is considered the temperature has a significant effect on the efficiency. This work was developed in order asses the feasibility to improve communal septic tanks efficiency by increasing content temperature. Temperatures inside the tank were increased using a hybrid heater system (solar and electricity). (Author)

  16. Modeling the temperature dependence of thermophysical properties: Study on the effect of temperature dependence for RFA.

    Science.gov (United States)

    Watanabe, Hiroki; Kobayashi, Yo; Hashizume, Makoto; Fujie, Masakatsu G

    2009-01-01

    Radio frequency ablation (RFA) has increasingly been used over the past few years and RFA treatment is minimally invasive for patients. However, it is difficult for operators to control the precise formation of coagulation zones due to inadequate imaging modalities. With this in mind, an ablation system using numerical simulation to analyze the temperature distribution of the organ is needed to overcome this deficiency. The objective of our work is to develop a temperature dependent thermophysical liver model. First, an overview is given of the development of the thermophysical liver model. Second, a simulation to evaluate the effect of temperature dependence of the thermophysical properties of the liver is explained. Finally, the result of the simulation, which indicated that the temperature dependence of thermophysical properties accounts for temperature differences influencing the accuracy of RFA treatment is described.

  17. Experimental and computational investigation of temperature effects on soot mechanisms

    Directory of Open Access Journals (Sweden)

    Bi Xiaojie

    2014-01-01

    Full Text Available Effects of initial ambient temperatures on combustion and soot emission characteristics of diesel fuel were investigated through experiment conducted in optical constant volume chamber and simulation using phenomenological soot model. There are four difference initial ambient temperatures adopted in our research: 1000 K, 900 K, 800 K and 700 K. In order to obtain a better prediction of soot behavior, phenomenological soot model was revised to take into account the soot oxidation feedback on soot number density and good agreement was observed in the comparison of soot measurement and prediction. Results indicated that ignition delay prolonged with the decrease of initial ambient temperature. The heat release rate demonstrated the transition from mixing controlled combustion at high ambient temperature to premixed combustion mode at low ambient temperature. At lower ambient temperature, soot formation and oxidation mechanism were both suppressed. But finally soot mass concentration reduced with decreasing initial ambient temperature. Although the drop in ambient temperature did not cool the mean in-cylinder temperature during the combustion, it did shrink the total area of local high equivalence ratio, in which soot usually generated fast. At 700 K initial ambient temperature, soot emissions were almost negligible, which indicates that sootless combustion might be achieved at super low initial temperature operation conditions.

  18. Temperature effects on neutron drip line

    International Nuclear Information System (INIS)

    Rajasekaran, M.; Aggarwal, Mamta

    1996-01-01

    Extremely neutron rich hot nuclei formed in high energy collisions having high thermal excitation energies are investigated in the framework of statistical theory and the effect of level density parameter a = U/T 2 , on the drip line is analysed

  19. Microstructural Evolution and Mechanical Behavior of High Temperature Solders: Effects of High Temperature Aging

    Science.gov (United States)

    Hasnine, M.; Tolla, B.; Vahora, N.

    2018-04-01

    This paper explores the effects of aging on the mechanical behavior, microstructure evolution and IMC formation on different surface finishes of two high temperature solders, Sn-5 wt.% Ag and Sn-5 wt.% Sb. High temperature aging showed significant degradation of Sn-5 wt.% Ag solder hardness (34%) while aging has little effect on Sn-5 wt.% Sb solder. Sn-5 wt.% Ag experienced rapid grain growth as well as the coarsening of particles during aging. Sn-5 wt.% Sb showed a stable microstructure due to solid solution strengthening and the stable nature of SnSb precipitates. The increase of intermetallic compound (IMC) thickness during aging follows a parabolic relationship with time. Regression analysis (time exponent, n) indicated that IMC growth kinetics is controlled by a diffusion mechanism. The results have important implications in the selection of high temperature solders used in high temperature applications.

  20. Effect of temperature on shelf life, chemical and microbial properties ...

    African Journals Online (AJOL)

    Cream cheese samples were analyzed to find out the effect of recommended storage temperature (4±1°C) and ambient room temperature (21±1°C) on pH, titratable acidity (% lactic acid), moisture content and microbial growth. Percent reduction in moisture content and increase in titratable acidity of cheeses were found to ...

  1. Temperature effects on quantum interference in molecular junctions

    DEFF Research Database (Denmark)

    Markussen, Troels; Thygesen, Kristian Sommer

    2014-01-01

    A number of experiments have demonstrated that destructive quantum interference (QI) effects in molecular junctions lead to very low conductances even at room temperature. On the other hand, another recent experiment showed increasing conductance with temperature which was attributed to decoheren...

  2. Effect of temperature and time on solvothermal synthesis of ...

    Indian Academy of Sciences (India)

    Effect of temperature and time study on solvothermal synthesis of BaTiO3 revealed that a moderate reaction temperature i.e. 185◦C and longer reaction time favour tetragonal phase stabiliza- tion. Dissolution–precipitation appears to be the transformation mechanism for the crystallization of BaTiO3 from particulate TiO2 ...

  3. Effects of exhaust temperature on helicopter infrared signature

    International Nuclear Information System (INIS)

    Cheng-xiong, Pan; Jing-zhou, Zhang; Yong, Shan

    2013-01-01

    The effects of exhaust temperature on infrared signature (in 3–5 μm band) for a helicopter equipped with integrative infrared suppressor were numerically investigated. The internal flow of exhaust gas and the external downwash flow, as well as the mixing between exhaust gas and downwash were simulated by CFD software to determine the temperature distributions on the helicopter skin and in the exhaust plume. Based on the skin and plume temperature distributions, a forward–backward ray-tracing method was used to calculate the infrared radiation intensity from the helicopter with a narrow-band model. The results show that for a helicopter with its integrative infrared suppressor embedded inside its rear airframe, the exhaust temperature has significant influence on the plume radiation characteristics, while the helicopter skin radiation intensity has little impact. When the exhaust temperature is raised from 900 K to 1200 K, the plume radiation intensity in 3–5 μm band is increased by about 100%, while the skin radiation intensity is increased by only about 5%. In general, the effects of exhaust temperature on helicopter infrared radiation intensity are mainly concentrated on plume, especially obvious for a lower skin emissivity case. -- Highlights: ► The effect of exhaust temperature on infrared signature for a helicopter is numerically investigated. ► The impact of exhaust temperature on helicopter skin temperature is revealed. ► The impact of exhaust temperature on plume radiation characteristics is revealed. ► The impact of exhaust temperature on helicopter skin radiation is revealed. ► The impact of exhaust temperature on helicopter's total infrared radiation intensity is revealed

  4. Modeling the Temperature Effect of Orientations in Residential Buildings

    Directory of Open Access Journals (Sweden)

    Sabahat Arif

    2012-07-01

    Full Text Available Indoor thermal comfort in a building has been an important issue for the environmental sustainability. It is an accepted fact that their designs and planning consume a lot of energy in the modern architecture of 20th and 21st centuries. An appropriate orientation of a building can provide thermally comfortable indoor temperatures which otherwise can consume extra energy to condition these spaces through all the seasons. This experimental study investigates the potential effect of this solar passive design strategy on indoor temperatures and a simple model is presented for predicting indoor temperatures based upon the ambient temperatures.

  5. Interactive effects of temperature and habitat complexity on freshwater communities.

    Science.gov (United States)

    Scrine, Jennifer; Jochum, Malte; Ólafsson, Jón S; O'Gorman, Eoin J

    2017-11-01

    Warming can lead to increased growth of plants or algae at the base of the food web, which may increase the overall complexity of habitat available for other organisms. Temperature and habitat complexity have both been shown to alter the structure and functioning of communities, but they may also have interactive effects, for example, if the shade provided by additional habitat negates the positive effect of temperature on understory plant or algal growth. This study explored the interactive effects of these two major environmental factors in a manipulative field experiment, by assessing changes in ecosystem functioning (primary production and decomposition) and community structure in the presence and absence of artificial plants along a natural stream temperature gradient of 5-18°C. There was no effect of temperature or habitat complexity on benthic primary production, but epiphytic production increased with temperature in the more complex habitat. Cellulose decomposition rate increased with temperature, but was unaffected by habitat complexity. Macroinvertebrate communities were less similar to each other as temperature increased, while habitat complexity only altered community composition in the coldest streams. There was also an overall increase in macroinvertebrate abundance, body mass, and biomass in the warmest streams, driven by increasing dominance of snails and blackfly larvae. Presence of habitat complexity, however, dampened the strength of this temperature effect on the abundance of macroinvertebrates in the benthos. The interactive effects that were observed suggest that habitat complexity can modify the effects of temperature on important ecosystem functions and community structure, which may alter energy flow through the food web. Given that warming is likely to increase habitat complexity, particularly at higher latitudes, more studies should investigate these two major environmental factors in combination to improve our ability to predict the

  6. Temperature Dependence of the Resonant Magnetoelectric Effect in Layered Heterostructures

    Directory of Open Access Journals (Sweden)

    Dmitrii A. Burdin

    2017-10-01

    Full Text Available The dependence of the resonant direct magnetoelectric effect on temperature is studied experimentally in planar composite structures. Samples of rectangular shapes with dimensions of 5 mm × 20 mm employed ferromagnetic layers of either an amorphous (metallic glass alloy or nickel with a thickness of 20–200 μm and piezoelectric layers of single crystalline langatate material or lead zirconate titanate piezoelectric ceramics with a thickness of 500 μm. The temperature of the samples was varied in a range between 120 and 390 K by blowing a gaseous nitrogen stream around them. It is shown that the effective characteristics of the magnetoelectric effect—such as the mechanical resonance frequency fr, the quality factor Q and the magnitude of the magnetoelectric coefficient αE at the resonance frequency—are contingent on temperature. The interrelations between the temperature changes of the characteristics of the magnetoelectric effect and the temperature variations of the following material parameters—Young’s modulus Y, the acoustic quality factor of individual layers, the dielectric constant ε, the piezoelectric modulus d of the piezoelectric layer as well as the piezomagnetic coefficients λ(n of the ferromagnetic layer—are established. The effect of temperature on the characteristics of the nonlinear magnetoelectric effect is observed for the first time. The results can be useful for designing magnetoelectric heterostructures with specified temperature characteristics, in particular, for the development of thermally stabilized magnetoelectric devices.

  7. Peltier Effect Based Temperature Controlled System for Dielectric Spectroscopy

    Science.gov (United States)

    Mukda, T.; Jantaratana, P.

    2017-09-01

    The temperature control system was designed and built for application in dielectric spectroscopy. It is based on the dual-stage Peltier element that decreases electrical power and no cryogenic fluids are required. A proportional integral derivative controller was used to keep the temperature stability of the system. A Pt100 temperature sensor was used to measure temperature of the sample mounting stage. Effect of vacuum isolation and water-cooling on accuracy and stability of the system were also studied. With the incorporation of vacuum isolation and water-cooling at 18 °C, the temperature of the sample under test can be controlled in the range of -40 °C to 150 °C with temperature stability ± 0.025 °C.

  8. THE EFFECTS OF TEMPERATURE AND pH ON BACTERIAL ...

    African Journals Online (AJOL)

    PROF EKWUEME

    The effect of temperature and pH on bacterial degradation of latex paint under humid condition by .... blade and plastic bags as described by Okpokwasili and. Ituen(1996) and .... provided different ecological niche for bacteria at favourable ...

  9. rainfall and temperature effects on flowering and pollen productions ...

    African Journals Online (AJOL)

    RAINFALL AND TEMPERATURE EFFECTS ON FLOWERING AND POLLEN. PRODUCTIONS IN COCOA ... chocolate or for extracting cocoa butter. Although, all cultivated .... healthy flowers of the selected clones. These flowers were stored in ...

  10. Statistical analysis of the effects of relative humidity and temperature ...

    African Journals Online (AJOL)

    Isreal

    and temperature on radio refractivity over Nigeria using satellite data ... refractive index of air causes adverse effects such as multipath ... decreased power levels at the receiver and to increased ... the southern and central part of Nigeria.

  11. Finite-temperature effects in helical quantum turbulence

    Science.gov (United States)

    Clark Di Leoni, Patricio; Mininni, Pablo D.; Brachet, Marc E.

    2018-04-01

    We perform a study of the evolution of helical quantum turbulence at different temperatures by solving numerically the Gross-Pitaevskii and the stochastic Ginzburg-Landau equations, using up to 40963 grid points with a pseudospectral method. We show that for temperatures close to the critical one, the fluid described by these equations can act as a classical viscous flow, with the decay of the incompressible kinetic energy and the helicity becoming exponential. The transition from this behavior to the one observed at zero temperature is smooth as a function of temperature. Moreover, the presence of strong thermal effects can inhibit the development of a proper turbulent cascade. We provide Ansätze for the effective viscosity and friction as a function of the temperature.

  12. Theory of the superconducting proximity effect below the transition temperature

    International Nuclear Information System (INIS)

    Silvert, W.

    1975-01-01

    The form of the low-temperature theory of the superconducting proximity effect depends on whether the non-linear terms are assumed to depend only on the local value of the gap or on its average value over some finite range. The local assumption leads to smaller values of the gap and to unphysical results at low temperatures. The effect of non-locality is significant even in the Ginsburg-Landau regime. (author)

  13. Effect of irrigation fluid temperature on body temperature during arthroscopic elbow surgery in dogs.

    Science.gov (United States)

    Thompson, K R; MacFarlane, P D

    2013-01-01

    This prospective randomised clinical trial evaluated the effect of warmed irrigation fluid on body temperature in anaesthetised dogs undergoing arthroscopic elbow surgery. Nineteen dogs undergoing elbow arthroscopy were included in the study and were randomly allocated to one of two groups. Group RT received irrigation fluid at room temperature (RT) while dogs in group W received warmed (W) irrigation fluid (36°C). A standardised patient management and anaesthetic protocol was used and body temperature was measured at four time points; (T1) pre-anaesthetic examination, (T2) arrival into theatre, (T3) end of surgery and (T4) arrival into recovery. There was no significant difference in body temperature at any time point between the groups. The mean overall decrease in body temperature between pre-anaesthetic examination (T1) and return to the recovery suite (T4) was significant in both groups, with a fall of 1.06±0.58°C (pdogs were hypothermic (temperature management protocol in dogs undergoing elbow arthroscopy during general anaesthesia did not lead to decreased temperature losses.

  14. High temperature effects on compact-like structures

    Energy Technology Data Exchange (ETDEWEB)

    Bazeia, D.; Lima, E.E.M.; Losano, L. [Universidade Federal da Paraiba, Departamento de Fisica, Joao Pessoa, PB (Brazil)

    2016-08-15

    In this work we investigate the transition from kinks to compactons at high temperatures. We deal with a family of models, described by a real scalar field with standard kinematics, controlled by a single parameter, real and positive. The family of models supports kink-like solutions, and the solutions tend to become compact when the parameter increases to larger and larger values. We study the one-loop corrections at finite temperature, to see how the thermal effects add to the effective potential. The results suggest that the symmetry is restored at very high temperatures. (orig.)

  15. Chiral symmetry and finite temperature effects in quantum theories

    International Nuclear Information System (INIS)

    Larsen, Aa.

    1987-01-01

    A computer simulation of the harmonic oscillator at finite temperature has been carried out, using the Monte Carlo Metropolis algorithm. Accurate results for the energy and fluctuations have been obtained, with special attention to the manifestation of the temperature effects. Varying the degree of symmetry breaking, the finite temperature behaviour of the asymmetric linear model in a linearized mean field approximation has been studied. In a study of the effects of chiral symmetry on baryon mass splittings, reasonable agreement with experiment has been obtained in a non-relativistic harmonic oscillator model

  16. Temperature dependence of the elastocaloric effect in natural rubber

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Zhongjian, E-mail: zhongjian.xie521@gmail.com; Sebald, Gael; Guyomar, Daniel

    2017-07-12

    The temperature dependence of the elastocaloric (eC) effect in natural rubber (NR) has been studied. This material exhibits a large eC effect over a broad temperature range from 0 °C to 49 °C. The maximum adiabatic temperature change (ΔT) occurred at 10 °C and the behavior could be predicted by the temperature dependence of the strain-induced crystallization (SIC) and the temperature-induced crystallization (TIC). The eC performance of NR was then compared with that of shape memory alloys (SMAs). This study contributes to the SIC research of NR and also broadens the application of elastomers. - Highlights: • A large elastocaloric effect over a broad temperature range was found in natural rubber (NR). • The caloric performance of NR was compared with that of shape memory alloys. • The temperature dependence of the elastocaloric effect in NR can be prediced by the theory of strain-induced crystallization.

  17. HAp physical investigation - the effect of sintering temperature

    International Nuclear Information System (INIS)

    Mohd Reusmaazran Yusof; Idris Besar; Rusnah Mustaffa; Cik Rohaida Che Hak

    2004-01-01

    The paper presents the effect of sintering temperature on the physical properties of porous hydroxyapatite (HAp). In this study, the HAp was prepared using polymeric sponge techniques with different binder concentration. The sintering process was carried out in air for temperature ranging from 1200 degree C to 1600 degree C. Different physical properties namely density and porosity were observed at different sintering temperatures. The HAp prepared with higher PVP binder showed a slightly decreased in apparent density with increasing sintering temperature, while those HAp prepared with lower PVP showed a slightly increase in apparent density with increasing sintering temperature. The total porosity was found to be approximately constant in the whole sintering temperature range. However, closed porosity decreases with increasing sintering temperature for HAp prepared by lower binder concentration. On the other hand, the HAp prepared by higher binder concentration HAp showed increasing closed porosity with increasing sintering temperature. Other features such as the influence of sintering temperatures on grain and strut also be presented in this paper. (Author)

  18. Effect of temperature on task performance in officeenvironment

    Energy Technology Data Exchange (ETDEWEB)

    Seppanen, Olli; Fisk, William J.; Lei, Q.H.

    2006-07-01

    Indoor temperature is one of the fundamental characteristics of the indoor environment. It can be controlled with a degree of accuracy dependent on the building and its HVAC system. The indoor temperature affects several human responses, including thermal comfort, perceived air quality, sick building syndrome symptoms and performance at work. In this study, we focused on the effects of temperature on performance at office work. We included those studies that had used objective indicators of performance that are likely to be relevant in office type work, such as text processing, simple calculations (addition, multiplication), length of telephone customer service time, and total handling time per customer for call-center workers. We excluded data from studies of industrial work performance. We calculated from all studies the percentage of performance change per degree increase in temperature, and statistically analyzed measured work performance with temperature. The results show that performance increases with temperature up to 21-22 C, and decreases with temperature above 23-24 C. The highest productivity is at temperature of around 22 C. For example, at the temperature of 30 C, the performance is only 91.1% of the maximum i.e. the reduction in performance is 8.9%

  19. Temperature effect compensation for fast differential pressure decay testing

    International Nuclear Information System (INIS)

    Shi, Yan; Tong, Xiaomeng; Cai, Maolin

    2014-01-01

    To avoid the long temperature recovery period with differential pressure decay for leak detection, a novel method with temperature effect compensation is proposed to improve the testing efficiency without full stabilization of temperature. The mathematical model of conventional differential pressure decay testing is established to analyze the changes of temperature and pressure during the measuring period. Then the differential pressure is divided into two parts: the exponential part caused by temperature recovery and the linear part caused by leak. With prior information obtained from samples, parameters of the exponential part can be identified precisely, and the temperature effect will be compensated before it fully recovers. To verify the effect of the temperature compensated method, chambers with different volumes are tested under various pressures and the experiments show that the improved method is faster with satisfactory precision, and an accuracy less than 0.25 cc min −1  can be achieved when the compensation time is proportional to four times the theoretical thermal-time constant. (paper)

  20. Effect of In-situ Cure on Measurement of Glass Transition Temperatures in High-temperature Thermosetting Polymers

    Science.gov (United States)

    2015-01-01

    TEMPERATURES IN HIGH-TEMPERATURE THERMOSETTING POLYMERS 5a. CONTRACT NUMBER In-House 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S...illustrated the difficulties inherent in measurement of the glass transition temperature of this high-temperature thermosetting polymer via dynamic...copyright protection in the United States. EFFECT OF IN-SITU CURE ON MEASUREMENT OF GLASS TRANSITION TEMPERATURES IN HIGH-TEMPERATURE THERMOSETTING

  1. The effectiveness of dispersants under various temperature and salinity regimes

    International Nuclear Information System (INIS)

    Fingas, M.; Fieldhouse, B.; Wang, Z.; Environment Canada, Ottawa, ON

    2005-01-01

    A series of tests were conducted to determine the effectiveness of dispersants in Arctic waters where salinity and temperature interactions play a critical role. In particular, Corexit 9500 was tested on Alaska North Slope oil at different temperatures and salinity using the ASTM standard test and variations of this test. Results were compared to the only historically reported test in which both temperature and salinity were changed over a range of values. This series of tests demonstrated that there is an interaction between salinity, temperature and dispersant effectiveness. It was shown that conventional and currently available dispersants are nearly ineffective at 0 salinity. Dispersant effectiveness peaks at 20 to 40 units of salinity, depending on the type of dispersant. Corexit is less sensitive to salinity, while Corexit 9527 is more sensitive to salinity. There is a smooth gradient of effectiveness with salinity both as the salinity rises to a peak point of effectiveness and as it exceeds this value. Results from the 2 field trials in fresh water suggest that laboratory tests correctly conclude that the effectiveness of dispersants is very low in freshwater. The study also examined several analytical factors such as the total petroleum hydrocarbon (TPH) versus relative petroleum hydrocarbon (RPH) methods, specific versus general calibration curves, and automatic versus manual baseline placement. The analytical variations of effectiveness by RPH or TPH methods do not affect the fundamental relationship between salinity and temperature. 6 refs., 6 tabs., 8 figs

  2. Conduction-corrected modified effective temperature as the indices of combined and separate effect of environmental factors on sensational temperature

    Energy Technology Data Exchange (ETDEWEB)

    Kurazumi, Yoshihito [School of Life Studies, Sugiyama Jogakuen University, 17-3 Hoshigaoka-motomachi, Chikusa-ku, Nagoya, Aichi 464-8662 (Japan); Tsuchikawa, Tadahiro [School of Human Science and Environment, University of Hyogo, 1-1-12 Hon-cho, Shinzaike, Himeji, Hyogo 670-0092 (Japan); Kondo, Emi [Graduate School Nagoya Institute of Technology, Gokiso-cyo, Showa-ku, Nagoya, Aichi 468555 (Japan); Horikoshi, Tetsumi [Department of Techno-Business Administration, Graduate School of Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya, Aichi 468555 (Japan); Matsubara, Naoki [Division of Environmental Sciences, Graduate School of Kyoto Prefectural University, Nakaragi-cho, Shimogamo, Sakyo-ku, Kyoto 608522 (Japan)

    2010-04-15

    In living spaces, people sit or lie on the floor and adopt a posture in which much of the surface of the body is in contact with the floor. When the temperature of the spatial structure or the surface temperature of an object in contact with the human body is not equivalent to the air temperature, these effects are non-negligible. Most research examining the physiological and psychological responses of the human body has involved subjects sitting in chairs. Research that takes into account body heat balance and assessments of thermal conduction into the environment is uncommon. Thus, in this study, conduction-corrected modified effective temperature (ETF), which is a new thermal environmental index incorporating heat conduction, is defined in order to make possible the evaluation of thermal environments that take into account different postures. This sensational temperature index converts the effects of the following parameters into a temperature equivalent: air velocity, thermal radiation, contact material surface temperature and humidity. This index has the features of a summation formula. Through the use of these parameters, it is possible to represent and quantify their composite influence on bodily sensation and the effects of discrete meteorological elements through an evaluation on an identical axis. (author)

  3. Effect of temperature on the radioiodination of human growth hormone

    International Nuclear Information System (INIS)

    Mohammed-Ali, S.A.; Salacinski, P.R.; Landon, J.

    1981-01-01

    Studies have been undertaken to assess the effect of altering the temperature at which human growth hormone is radioiodinated on the incorporation of 125 I and the immunoreactivity and stability of the labelled hormone. Employing highly purified monomeric hormone it proved possible, by the iodogen procedure, to prepare a labelled product of high specific activity irrespective of temperature. However, in radioiodinations performed at ambient temperature (20 to 25 degrees) significant amounts of the labelled hormone were in an aggregated form which was less immunoreactive than the 125 I-labelled monomeric hormone. Such aggregation was largely prevented by radioiodinating at low temperature (0 to 4 degrees) and even the large monomeric peak was more immunoreactive (about 95% bound in antibody excess) than the monomeric peak from iodinations performed at room temperature

  4. Temperature effects on radiation damage in plastic detectors

    International Nuclear Information System (INIS)

    Mendoza A, D.

    1996-01-01

    The objective of present work was to study the temperature effect on radiation damage registration in the structure of a Solid State Nuclear Track Detector of the type CR-39. In order to study the radiation damage as a function of irradiation temperature, sheets of CR-39 detectors were irradiated with electron beams, simulating the interaction of positive ions. CR-39 detectors were maintained at a constant temperature from room temperature up to 373 K during irradiation. Two techniques were used from analyzing changes in the detector structure: Electronic Paramagnetic Resonance (EPR) and Infrared Spectroscopy (IR). It was found by EPR analysis that the amount of free radicals decrease as irradiation temperature increases. The IR spectrums show yield of new functional group identified as an hydroxyl group (OH). A proposed model of interaction of radiation with CR-39 detectors is discussed. (Author)

  5. Comparing the effect of pressure and temperature on ion mobilities

    International Nuclear Information System (INIS)

    Tabrizchi, Mahmoud; Rouholahnejad, Fereshteh

    2005-01-01

    The effect of pressure on ion mobilities has been investigated and compared with that of temperature. In this connection, an ion mobility spectrometry (IMS) cell, which employs a corona discharge as the ionization source, has been designed and constructed to allow varying pressure inside the drift region. IMS spectra were recorded at various pressures ranging from 15 Torr up to atmospheric pressure. The results show that IMS peaks shift perfectly linear with pressure which is in excellent agreement with the ion mobility theory. However, experimental ion mobilities versus temperature show deviation from the theoretical trend. The deviation is attributed to formation of clusters. The different behaviour of pressure and temperature was explained on the basis of the different impact of pressure and temperature on hydration and clustering of ions. Pressure affects the clustering reactions linearly but temperature affects it exponentially

  6. Impervious surfaces and sewer pipe effects on stormwater runoff temperature

    Science.gov (United States)

    Sabouri, F.; Gharabaghi, B.; Mahboubi, A. A.; McBean, E. A.

    2013-10-01

    The warming effect of the impervious surfaces in urban catchment areas and the cooling effect of underground storm sewer pipes on stormwater runoff temperature are assessed. Four urban residential catchment areas in the Cities of Guelph and Kitchener, Ontario, Canada were evaluated using a combination of runoff monitoring and modelling. The stormwater level and water temperature were monitored at 10 min interval at the inlet of the stormwater management ponds for three summers 2009, 2010 and 2011. The warming effect of the ponds is also studied, however discussed in detail in a separate paper. An artificial neural network (ANN) model for stormwater temperature was trained and validated using monitoring data. Stormwater runoff temperature was most sensitive to event mean temperature of the rainfall (EMTR) with a normalized sensitivity coefficient (Sn) of 1.257. Subsequent levels of sensitivity corresponded to the longest sewer pipe length (LPL), maximum rainfall intensity (MI), percent impervious cover (IMP), rainfall depth (R), initial asphalt temperature (AspT), pipe network density (PND), and rainfall duration (D), respectively. Percent impervious cover of the catchment area (IMP) was the key parameter that represented the warming effect of the paved surfaces; sensitivity analysis showed IMP increase from 20% to 50% resulted in runoff temperature increase by 3 °C. The longest storm sewer pipe length (LPL) and the storm sewer pipe network density (PND) are the two key parameters that control the cooling effect of the underground sewer system; sensitivity analysis showed LPL increase from 345 to 966 m, resulted in runoff temperature drop by 2.5 °C.

  7. Effect of temperature and benzalkonium chloride on nitrate reduction.

    Science.gov (United States)

    Hajaya, Malek G; Tezel, Ulas; Pavlostathis, Spyros G

    2011-04-01

    The effect of temperature and benzalkonium chloride (BAC) on nitrate reduction was investigated in batch assays using a mixed nitrate reducing culture. Nitrate was transformed completely, mainly through denitrification, to dinitrogen at 5, 10, 15 and 22 °C. In the absence of BAC, reduction of individual nitrogen oxides had different susceptibility to temperature and transient nitrite accumulation was observed at low temperatures. When the effect of BAC was tested up to 100 mg/L from 5 to 22 °C, denitrification was inhibited at and above 50mg BAC/L with transient nitrite accumulation at all temperatures. The effect of BAC was described by a competitive inhibition model. Nitrite reduction was the denitrification step most susceptible to BAC, especially at low temperatures. BAC was not degraded during the batch incubation and was mostly biomass-adsorbed. Overall, this study shows that low temperatures exacerbate the BAC inhibitory effect, which in turn is controlled by adsorption to biomass. Copyright © 2011 Elsevier Ltd. All rights reserved.

  8. Effect of ambient temperature and relative humidity on interfacial temperature during early stages of drop evaporation.

    Science.gov (United States)

    Fukatani, Yuki; Orejon, Daniel; Kita, Yutaku; Takata, Yasuyuki; Kim, Jungho; Sefiane, Khellil

    2016-04-01

    Understanding drop evaporation mechanisms is important for many industrial, biological, and other applications. Drops of organic solvents undergoing evaporation have been found to display distinct thermal patterns, which in turn depend on the physical properties of the liquid, the substrate, and ambient conditions. These patterns have been reported previously to be bulk patterns from the solid-liquid to the liquid-gas drop interface. In the present work the effect of ambient temperature and humidity during the first stage of evaporation, i.e., pinned contact line, is studied paying special attention to the thermal information retrieved at the liquid-gas interface through IR thermography. This is coupled with drop profile monitoring to experimentally investigate the effect of ambient temperature and relative humidity on the drop interfacial thermal patterns and the evaporation rate. Results indicate that self-generated thermal patterns are enhanced by an increase in ambient temperature and/or a decrease in humidity. The more active thermal patterns observed at high ambient temperatures are explained in light of a greater temperature difference generated between the apex and the edge of the drop due to greater evaporative cooling. On the other hand, the presence of water humidity in the atmosphere is found to decrease the temperature difference along the drop interface due to the heat of adsorption, absorption and/or that of condensation of water onto the ethanol drops. The control, i.e., enhancement or suppression, of these thermal patterns at the drop interface by means of ambient temperature and relative humidity is quantified and reported.

  9. Temperature effects on hospital admissions for kidney morbidity in Taiwan

    International Nuclear Information System (INIS)

    Lin, Yu-Kai; Wang, Yu-Chun; Ho, Tsung-Jung; Lu, Chensheng

    2013-01-01

    Objective: This study aimed to associate hospital admissions of kidney diseases with extreme temperature and prolonged heat/cold events in 7 regions of Taiwan. Methods: Age-specific ( 10 , O 3 , and NO 2 ) and potential confounders. Results: We observed a V or J-shape association between daily average temperatures and the RR estimates for hospital admissions of kidney diseases in Taiwan. The lowest risk for hospital admissions of kidney diseases was found at around 25 °C, and risk increased as temperatures deviated from 25 °C. The pooled cumulative 8-day RR for all ages of population of the 7 study areas were 1.10 (95% confidence interval (CI): 1.01, 1.19) at 18 °C and 1.45 (95% CI: 1.27, 1.64) at 30 °C. High temperature has more profound influence on hospital admission of kidney diseases than low temperature. Temperature risks for hospital admissions were similar between younger (< 65 years) and elderly (65 + years) population. This study observed no significant effects of prolonged heat extremes on hospital admissions of kidney diseases. Conclusions: The heat effect for kidney morbidities leading to hospital admission was more significant than that of the cold temperature. This study did not find the age-dependent relative risks for temperature associating with hospital admissions of kidney diseases. - Highlights: ► V or J-shaped association was observed between daily temperatures and hospital admissions for renal diseases in Taiwan. ► The pooled relative risks accounting for 8 days of lag for the 7 study areas were 1.1 at 18 °C and 1.46 at 30 °C. ► There is no difference of the relative risk estimates for hospital admissions between younger and elderly population. ► We found significant protective effects of hospital admissions for prolonged cold extremes, but not for heat extremes

  10. Load forecasting method considering temperature effect for distribution network

    Directory of Open Access Journals (Sweden)

    Meng Xiao Fang

    2016-01-01

    Full Text Available To improve the accuracy of load forecasting, the temperature factor was introduced into the load forecasting in this paper. This paper analyzed the characteristics of power load variation, and researched the rule of the load with the temperature change. Based on the linear regression analysis, the mathematical model of load forecasting was presented with considering the temperature effect, and the steps of load forecasting were given. Used MATLAB, the temperature regression coefficient was calculated. Using the load forecasting model, the full-day load forecasting and time-sharing load forecasting were carried out. By comparing and analyzing the forecast error, the results showed that the error of time-sharing load forecasting method was small in this paper. The forecasting method is an effective method to improve the accuracy of load forecasting.

  11. Effects of pressure and temperature on gate valve unwedging

    Energy Technology Data Exchange (ETDEWEB)

    Damerell, P.S.; Harrison, D.H.; Hayes, P.W.; Simons, J.W.; Walker, T.A.

    1996-12-01

    The stem thrust required to unwedge a gate valve is influenced by the pressure and temperature when the valve is closed and by the changes in these conditions between closure and opening. {open_quotes}Pressure locking{close_quotes} and {open_quotes}thermal binding{close_quotes} refer to situations where pressure and temperature effects cause the unwedging load to be much higher than normal. A model of these phenomena has been developed. Wedging (closure) is modeled as developing an {open_quotes}interference{close_quotes} between the disk and its seat rings in the valve. The effects of pressure and temperature are analyzed to determine the change in this disk-to-seat {open_quotes}interference{close_quotes}. Flexibilities, of the disk, body, stem and yoke strongly influence the unwedging thrust. Calculations and limited comparisons to data have been performed for a range of valve designs and scenarios. Pressure changes can increase the unwedging load when there is either a uniform pressure decrease, or a situation where the bonnet pressure exceeds the pressures in the adjacent piping. Temperature changes can increase the unwedging load when: (1) valve closure at elevated system temperature produces a delayed stem expansion, (2) a temperature increase after closure produces a bonnet pressure increase, or (3) a temperature change after closure produces an increase in the disk-to-seat {open_quotes}interference{close_quotes} or disk-to-seat friction.

  12. Effects of pressure and temperature on gate valve unwedging

    International Nuclear Information System (INIS)

    Damerell, P.S.; Harrison, D.H.; Hayes, P.W.; Simons, J.W.; Walker, T.A.

    1996-01-01

    The stem thrust required to unwedge a gate valve is influenced by the pressure and temperature when the valve is closed and by the changes in these conditions between closure and opening. open-quotes Pressure lockingclose quotes and open-quotes thermal bindingclose quotes refer to situations where pressure and temperature effects cause the unwedging load to be much higher than normal. A model of these phenomena has been developed. Wedging (closure) is modeled as developing an open-quotes interferenceclose quotes between the disk and its seat rings in the valve. The effects of pressure and temperature are analyzed to determine the change in this disk-to-seat open-quotes interferenceclose quotes. Flexibilities, of the disk, body, stem and yoke strongly influence the unwedging thrust. Calculations and limited comparisons to data have been performed for a range of valve designs and scenarios. Pressure changes can increase the unwedging load when there is either a uniform pressure decrease, or a situation where the bonnet pressure exceeds the pressures in the adjacent piping. Temperature changes can increase the unwedging load when: (1) valve closure at elevated system temperature produces a delayed stem expansion, (2) a temperature increase after closure produces a bonnet pressure increase, or (3) a temperature change after closure produces an increase in the disk-to-seat open-quotes interferenceclose quotes or disk-to-seat friction

  13. Effects of tissue susceptibility on brain temperature mapping.

    Science.gov (United States)

    Maudsley, Andrew A; Goryawala, Mohammed Z; Sheriff, Sulaiman

    2017-02-01

    A method for mapping of temperature over a large volume of the brain using volumetric proton MR spectroscopic imaging has been implemented and applied to 150 normal subjects. Magnetic susceptibility-induced frequency shifts in gray- and white-matter regions were measured and included as a correction in the temperature mapping calculation. Additional sources of magnetic susceptibility variations of the individual metabolite resonance frequencies were also observed that reflect the cellular-level organization of the brain metabolites, with the most notable differences being attributed to changes of the N-Acetylaspartate resonance frequency that reflect the intra-axonal distribution and orientation of the white-matter tracts with respect to the applied magnetic field. These metabolite-specific susceptibility effects are also shown to change with age. Results indicate no change of apparent brain temperature with age from 18 to 84 years old, with a trend for increased brain temperature throughout the cerebrum in females relative for males on the order of 0.1°C; slightly increased temperatures in the left hemisphere relative to the right; and a lower temperature of 0.3°C in the cerebellum relative to that of cerebral white-matter. This study presents a novel acquisition method for noninvasive measurement of brain temperature that is of potential value for diagnostic purposes and treatment monitoring, while also demonstrating limitations of the measurement due to the confounding effects of tissue susceptibility variations. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. Temperature effect on Zircaloy-4 stress corrosion cracking

    International Nuclear Information System (INIS)

    Farina, Silvia B.; Duffo, Gustavo S.; Galvele, Jose R.

    1999-01-01

    Stress corrosion cracking (SCC) susceptibility of Zircaloy-4 alloy in chloride, bromide and iodide solutions with variables as applied electrode potential, deformation rate and temperature have been studied. In those three halide solutions the susceptibility to SCC is only observed at potentials close to pitting potential, the crack propagation rate increases with the increase of deformation rate, and that the temperature has a notable effect only for iodide solutions. For chloride and bromide solutions and temperatures ranging between 20 to 90 C degrees it was not found measurable changes in crack propagation rates. (author)

  15. The effect of temperature and oxygen content on coal burnout

    Energy Technology Data Exchange (ETDEWEB)

    K. Milenkova; A.G. Borrego; D. Alvarez; J. Xiberta; R. Menendez [Instituto Nacional del Carbon, CSIC, Oviedo (Spain)

    2003-07-01

    In this study chars from six coals differing in rank and maceral composition have been prepared at 1100 and 1300{sup o}C in a drop tube reactor using four oxygen concentrations (0, 2.5, 10 and 21% oxygen). Char burnout, reactivity, morphology and optical texture have been considered in an attempt to understand the effect of temperature and oxygen concentration in relation to coal characteristics. Temperature has shown to have a different effect on conversion depending on coal rank. The high volatile coals showed similar conversions at 1100 and 1300{sup o}C at the various atmospheres tested, whereas higher rank coals showed higher conversions at 1300 than at 1100{sup o}C. The presence of oxygen in the reacting gas appears to have two opposite effects on coal combustion. On the one hand it prevents swelling and devolatilisation and on the other it enhances combustion. The burnout will depend on which process dominates. In addition, this effect appears to be temperature dependant and the inhibiting effect of oxygen on coal devolatilisation has shown to be higher at higher temperature, since at low temperature it only affects the lowest ranked coals. The presence of oxygen also affects the structure of carbonaceous material since the lower the oxygen concentration the higher the anisotropy development. The difference in temperature separating the two series of experiments (1000 and 1300{sup o}C) did not have a positive effect on the conversion of coals yielding highly porous chars whereas for coals yielding more dense structures higher conversions were achieved at higher temperatures. 7 refs., 5 figs., 1 tab.

  16. Effect of ultraviolet rays in low temperature Si02 deposition

    International Nuclear Information System (INIS)

    Calix, V.M.; Peccoud, L.; Chevallier, M.

    1976-09-01

    Vitreous silicon dioxide films have been prepared on silicon wafers by the oxidation of SiH 2 at temperature below 360 deg C. In this experiment the samples were exposed to ultraviolet rays during deposition process. Results show that there is marked effect on the deposition rate which in turn is temperature dependent. The physical characteristics between the normal and ultraviolet-enhanced deposition show an increase of minute nodules of the latter

  17. The Path of Carbon in Photosynthesis XII. Some Temperature Effects

    Science.gov (United States)

    Ouellet, C.

    1951-06-25

    The photosynthetic assimilation of radioactive carbon dioxide for two-minute periods by Scenedesmus has bee studied at temperatures ranging from 25? to 44? C. All labeled intermediates cease to be formed at about 45? C. With rising temperature, the radioactivity reaching the sugar phosphate reservoirs decreases regularly while there is a sharp maximum in sucrose at 37? C. and a less pronounced one in malic and aspartic acids about 40? C. A tentative interpretation of these effects is offered.

  18. Effect of increasing growth temperature on yeast fermentation ...

    African Journals Online (AJOL)

    The effect of increasing growth temperature on yeast fermentation was studied at approximately 5 oC intervals over a range of 18 – 37 oC, using one strain each of ale, lager and wine yeast. The ale and wine yeasts grew at all the temperatures tested, but lager yeast failed to grow at 37 oC. All these strains gave lower ...

  19. The effect of non-uniform fuel rod temperatures on effective resonance integrals

    International Nuclear Information System (INIS)

    Reichel, A.

    1961-06-01

    The effective resonance integral for heterogeneous lattices can be reduced to the effective resonance integral for an equivalent homogeneous system with a fairly well defined error depending on lump size and geometry. This report investigates the effect of a radial parabolic temperature variation in cylindrical lumps on the equivalent homogeneous effective resonance integral. Also determined is the equivalent uniform temperature to be taken in the usual formulae to allow for non-uniform fuel rod temperature. This effective temperature is found to be T eff. = T s + 4/9 (T c - T s ) where T s and T c are the surface and central temperatures of the lump. (author)

  20. Effects of repetition and temperature on Contingent Electrical Stimulation

    DEFF Research Database (Denmark)

    Castrillon, Eduardo E.; Zhou, Xinwen; Svensson, Peter

    ) activity associated with bruxism. Repetition of the electrical stimulus and skin surface temperature (ST) may affect the perception of CES and possibly also the inhibitory EMG effects.Objectives: To determine the effects of stimulus repetition and skin ST on the perception of CES.  Methods: Healthy...

  1. Effect of Pyrolysis Temperature on Cadmium and Lead ...

    African Journals Online (AJOL)

    Consumption of tobacco as cigarette or otherwise has been demonstrated to contribute to air pollution via smoke generation resulting in adverse health effect. Therefore, this study investigates the effect of pyrolysis temperature on the concentration, distribution of cadmium and lead between ash residue and smoke in some ...

  2. H/D isotope effects in high temperature proton conductors

    DEFF Research Database (Denmark)

    Bonanos, Nikolaos; Huijser, A.; Poulsen, Finn Willy

    2015-01-01

    The atomic mass ratio of ca. 2 between deuterium and hydrogen is the highest for any pair of stable isotopes and results in significant and measurable H/D isotope effects in high temperature proton conductors containing these species. This paper discusses H/D isotope effects manifested in O-H/O-D...

  3. Effect of temperature on the passivation behavior of steel rebar

    Science.gov (United States)

    Chen, Shan-meng; Cao, Bei; Wu, Yin-shun; Ma, Ke

    2014-05-01

    Steel rebar normally forms an oxide or rusty skin before it is embedded into concrete and the passivation properties of this skin will be heavily influenced by temperature. To study the effect of temperature on the passivation properties of steel rebar under different surface conditions, we conducted scanning electron microscopy (SEM) observations and electrochemical measurements, such as measurements of the free corrosion potential and polarization curves of HPB235 steel rebar. These measurements identified three kinds of surfaces: polished, oxide skin, and rusty skin. Our results show that the passivation properties of all the surface types decrease with the increase of temperature. Temperature has the greatest effect on the rusty-skin rebar and least effect on the polished steel rebar, because of cracks and crevices on the mill scale on the steel rebar's surface. The rusty-skin rebar exhibits the highest corrosion rate because crevice corrosion can accelerate the corrosion of the steel rebar, particularly at high temperature. The results also indicate that the threshold temperatures of passivation for the oxide-skin rebar and the rusty-skin rebar are 37°C and 20°C, respectively.

  4. The effects of temperatures on the pebble flow in a pebble bed high temperature reactor

    International Nuclear Information System (INIS)

    Sen, R. S.; Cogliati, J. J.; Gougar, H. D.

    2012-01-01

    The core of a pebble bed high temperature reactor (PBHTR) moves during operation, a feature which leads to better fuel economy (online refueling with no burnable poisons) and lower fuel stress. The pebbles are loaded at the top and trickle to the bottom of the core after which the burnup of each is measured. The pebbles that are not fully burned are recirculated through the core until the target burnup is achieved. The flow pattern of the pebbles through the core is of importance for core simulations because it couples the burnup distribution to the core temperature and power profiles, especially in cores with two or more radial burnup 'zones '. The pebble velocity profile is a strong function of the core geometry and the friction between the pebbles and the surrounding structures (other pebbles or graphite reflector blocks). The friction coefficient for graphite in a helium environment is inversely related to the temperature. The Thorium High Temperature Reactor (THTR) operated in Germany between 1983 and 1989. It featured a two-zone core, an inner core (IC) and outer core (OC), with different fuel mixtures loaded in each zone. The rate at which the IC was refueled relative to the OC in THTR was designed to be 0.56. During its operation, however, this ratio was measured to be 0.76, suggesting the pebbles in the inner core traveled faster than expected. It has been postulated that the positive feedback effect between inner core temperature, burnup, and pebble flow was underestimated in THTR. Because of the power shape, the center of the core in a typical cylindrical PBHTR operates at a higher temperature than the region next to the side reflector. The friction between pebbles in the IC is lower than that in the OC, perhaps causing a higher relative flow rate and lower average burnup, which in turn yield a higher local power density. Furthermore, the pebbles in the center region have higher velocities than the pebbles next to the side reflector due to the

  5. The effects of temperatures on the pebble flow in a pebble bed high temperature reactor

    Energy Technology Data Exchange (ETDEWEB)

    Sen, R. S.; Cogliati, J. J.; Gougar, H. D. [Idaho National Laboratory, P.O. Box 1625, Idaho Falls, ID 83415 (United States)

    2012-07-01

    The core of a pebble bed high temperature reactor (PBHTR) moves during operation, a feature which leads to better fuel economy (online refueling with no burnable poisons) and lower fuel stress. The pebbles are loaded at the top and trickle to the bottom of the core after which the burnup of each is measured. The pebbles that are not fully burned are recirculated through the core until the target burnup is achieved. The flow pattern of the pebbles through the core is of importance for core simulations because it couples the burnup distribution to the core temperature and power profiles, especially in cores with two or more radial burnup 'zones '. The pebble velocity profile is a strong function of the core geometry and the friction between the pebbles and the surrounding structures (other pebbles or graphite reflector blocks). The friction coefficient for graphite in a helium environment is inversely related to the temperature. The Thorium High Temperature Reactor (THTR) operated in Germany between 1983 and 1989. It featured a two-zone core, an inner core (IC) and outer core (OC), with different fuel mixtures loaded in each zone. The rate at which the IC was refueled relative to the OC in THTR was designed to be 0.56. During its operation, however, this ratio was measured to be 0.76, suggesting the pebbles in the inner core traveled faster than expected. It has been postulated that the positive feedback effect between inner core temperature, burnup, and pebble flow was underestimated in THTR. Because of the power shape, the center of the core in a typical cylindrical PBHTR operates at a higher temperature than the region next to the side reflector. The friction between pebbles in the IC is lower than that in the OC, perhaps causing a higher relative flow rate and lower average burnup, which in turn yield a higher local power density. Furthermore, the pebbles in the center region have higher velocities than the pebbles next to the side reflector due to the

  6. Effective temperature of the non-equilibrium electrons in a degenerate semiconductor at low lattice temperature

    Energy Technology Data Exchange (ETDEWEB)

    Das, B.; Basu, A.; Das, J.; Bhattacharya, D.P., E-mail: d_p_bhattacharya@rediffmail.com

    2015-10-01

    The energy balance equation for the electron–phonon system is recast taking the degeneracy of the carrier ensemble into account. The effect of degeneracy on the field dependence of the temperature of the non-equilibrium carriers has been studied by solving the same equation. The high field distribution function of the carriers is assumed to be given by the Fermi Dirac function at the field dependent carrier temperature. The distribution function has been approximated in a way that facilitates analytical solution of the problem without any serious loss of accuracy. The field dependence of the electron temperature thus obtained seems to be significantly different from what follows had the degeneracy not been taken into account. The agreement of the results obtained from the present analysis with the available experimental data for Ge and InSb are quite satisfactory. The scope of further refinement of the present theory is highlighted.

  7. Solvated electrons at elevated temperatures in different alcohols: Temperature and molecular structure effects

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Yu [Department of Nuclear Engineering and Management, Graduate School of Engineering, University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-8656 (Japan); Lin, Mingzhang [Nuclear Science and Engineering Directorate, Japan Atomic Energy Agency, 2-4 Shirakata-Shirane, Tokai, Naka, Ibaraki 319-1195 (Japan); Katsumura, Yosuke, E-mail: katsu@n.t.u-tokyo.ac.j [Department of Nuclear Engineering and Management, Graduate School of Engineering, University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-8656 (Japan); Nuclear Professional School, Graduate School of Engineering, University of Tokyo, 2-22 Shirakata-Shirane, Tokai, Naka, Ibaraki 319-1188 (Japan); Fu, Haiying; Muroya, Yusa [Nuclear Professional School, Graduate School of Engineering, University of Tokyo, 2-22 Shirakata-Shirane, Tokai, Naka, Ibaraki 319-1188 (Japan)

    2010-12-15

    The absorption spectra of solvated electrons in pentanol, hexanol and octanol are measured from 22 to 200, 22 to 175 and 50 to150 {sup o}C, respectively, at a fixed pressure of 15 MPa, using nanosecond pulse radiolysis technique. The results show that the peak positions of the absorption spectra have a red-shift (shift to longer wavelengths) as temperature increases, similar to water and other alcohols. Including the above mentioned data, a compilation of currently available experimental data on the energy of absorption maximum (E{sub max}) of solvated electrons changed with temperature in monohydric alcohols, diols and triol is presented. E{sub max} of solvated electron is larger in those alcohols that have more OH groups at all the temperatures. The molecular structure effect, including OH numbers, OH position and carbon chain length, is investigated. For the primary alcohols with same OH group number and position, the temperature coefficient increases with increase in chain length. For the alcohols with same chain length and OH numbers, temperature coefficient is larger for the symmetric alcohols than the asymmetric ones.

  8. Canceling effect leads temperature insensitivity of hydrolytic enzymes in soil

    Science.gov (United States)

    Razavi, Bahar S.; Blagodatskaya, Evgenia; Kuzyakov, Yakov

    2015-04-01

    Extracellular enzymes are important for decomposition of many macromolecules abundant in soil such as cellulose, hemicelluloses and proteins (Allison et al., 2010; Chen et al., 2012). The temperature sensitivity of enzymes responsible for organic matter decomposition is the most crucial parameter for prediction of the effects of global warming on carbon cycle. Temperature responses of biological systems are often expressed as a Q10 functions; The Q10 describes how the rate of a chemical reaction changes with a temperature increase for 10 °C The aim of this study was to test how the canceling effect will change with variation in temperature interval, during short-term incubation. We additionally investigated, whether canceling effect occurs in a broad range of concentrations (low to high) and whether it is similar for the set of hydrolytic enzymes within broad range of temperatures. To this end, we performed soil incubation over a temperature range of 0-40°C (with 5°C steps). We determined the activities of three enzymes involved in plant residue decomposition: β-glucosidase and cellobiohydrolase, which are commonly measured as enzymes responsible for degrading cellulose (Chen et al., 2012), and xylanase, which degrades xylooligosaccharides (short xylene chain) in to xylose, thus being responsible for breaking down hemicelluloses (German et al., 2011). Michaelis-Menten kinetics measured at each temperature allowed to calculate Q10 values not only for the whole reaction rates, but specifically for maximal reaction rate (Vmax) and substrate affinity (Km). Subsequently, the canceling effect - simultaneous increase of Vmax and Km with temperature was analyzed within 10 and 5 degree of temperature increase. Three temperature ranges (below 10, between 15 and 25, and above 30 °C) clearly showed non-linear but stepwise increase of temperature sensitivity of all three enzymes and allowed to conclude for predominance of psychrophilic, mesophilic and thermophilic

  9. Temperature, humidity and time., Combined effects on radiochromic film dosimeters

    International Nuclear Information System (INIS)

    Abdel-Fattah, A.A.; Miller, A.

    1996-01-01

    The effects of both relative humidity and temperature during irradiation on the dose response of FWT-60-00 and Riso B3 radiochromic film dosimeters have been investigated in the relative humidity (RH) range 11-94% and temperature range 20-60 o C for irradiation by 60 Co photons and 10-MeV electrons. The results show that humidity and temperature cannot be treated as independent variables, rather there appears to be interdependence between absorbed dose, temperature, and humidity. Dose rate does not seem to play a significant role. The dependence of temperature during irradiation is + 0.25 ± 0.1% per o C for the FWT-60-00 dosimeters and +0.5 ± 0.1% per o C for Riso B3 dosimeters at temperatures between 20 and 50 o C and at relative humidities between 20 and 53%. At extreme conditions both with respect to temperature and to humidity, the dosimeters show much stronger dependences. Whenever possible one should use dosimeters sealed in pouches under controlled intermediate humidity conditions (30-50%) or, if that is impractical, one should maintain conditions of calibration as close as possible to the conditions of use. Without that precaution, severe dosimetry errors may result. (author)

  10. The effects of spatial sampling choices on MR temperature measurements.

    Science.gov (United States)

    Todd, Nick; Vyas, Urvi; de Bever, Josh; Payne, Allison; Parker, Dennis L

    2011-02-01

    The purpose of this article is to quantify the effects that spatial sampling parameters have on the accuracy of magnetic resonance temperature measurements during high intensity focused ultrasound treatments. Spatial resolution and position of the sampling grid were considered using experimental and simulated data for two different types of high intensity focused ultrasound heating trajectories (a single point and a 4-mm circle) with maximum measured temperature and thermal dose volume as the metrics. It is demonstrated that measurement accuracy is related to the curvature of the temperature distribution, where regions with larger spatial second derivatives require higher resolution. The location of the sampling grid relative temperature distribution has a significant effect on the measured values. When imaging at 1.0 × 1.0 × 3.0 mm(3) resolution, the measured values for maximum temperature and volume dosed to 240 cumulative equivalent minutes (CEM) or greater varied by 17% and 33%, respectively, for the single-point heating case, and by 5% and 18%, respectively, for the 4-mm circle heating case. Accurate measurement of the maximum temperature required imaging at 1.0 × 1.0 × 3.0 mm(3) resolution for the single-point heating case and 2.0 × 2.0 × 5.0 mm(3) resolution for the 4-mm circle heating case. Copyright © 2010 Wiley-Liss, Inc.

  11. Temperature effects on interaction of positive ions with plastic detectors

    International Nuclear Information System (INIS)

    Mendoza Anaya, D.

    1992-01-01

    The range of heavy charged particles in matter is dependent mainly on two groups of parameters, one related to the particle characteristics (charge z, mass m, energy E) and the other characterized by the stopping medium (charge z, density ρ). Those two groups are enough to describe the particle energy lost, which is related to the residual range. Research on charge particles registration using solid state nuclear track detectors (SSNTD), probe that environmental parameters affect the stabilization and formation of the tracks. One of those, is the temperature detector which shows an important effect during the irradiation on the characteristics of the tracks produced. In order to study the dependence of track geometry as a function of irradiation temperature, some SSNTD (CR 39 type) were irradiated with α particles and fission fragments. Results of this work show the existence of irradiation temperature effect on the track geometry. It is observed a reduction of length and diameters, as temperature increases. For low irradiation temperatures, there is a reduction of the track geometry, as compared with environmental temperature. (Author)

  12. Effect of temperature to the properties of sago starch

    Science.gov (United States)

    Mustafa Kamal, M.; Baini, R.; Mohamaddan, S.; Selaman, O. S.; Zauzi, N. Ahmad; Rahman, M. R.; Rahman, N. Abdul; Chong, K. H.; Atan, M. F.; Samat, N. A. S. Abdul; Taib, S. N. L.; Othman, A. K.

    2017-06-01

    Recently, the importance of sago starch has increased, as it has become one of the main economically important agricultural crops to the most Southeast Asia countries. In the present work, an analysis on drying process of sago starch (Metroxylon sagu Rottb.) underwent various temperature has been made by using four empirical equations. The main goal of this analysis is to suggest the most accurate equation, in order to model and simulate the mechanical drying of sago starch. The experimental investigations were carried out in a gravity convection lab oven; and ±50g of sago starch (sample heights of 1 cm) was dried through four different temperatures, which were 50, 60, 70 and 80ºC. The effect of drying temperature on the drying kinetics, as well as various qualities attributes of sago starch, such as microstructure, colour and functional properties were investigated. The results suggested that drying temperature has significant effect on sago starch drying kinetic; therefore, drying temperature would be the basis to select drying condition. Meanwhile, it was found that the various drying temperature ranging from 50 to 80ºC affected the product quality especially in term of colour.

  13. Effects of Transverse Power Distribution on Fuel Temperature

    International Nuclear Information System (INIS)

    Jo, Daeseong; Park, Jonghark; Seo, Chul Gyo; Chae, Heetaek

    2014-01-01

    In the present study, transverse power distributions with segments of 4 and 18 are evaluated. Based on the power distribution, the fuel temperatures are evaluated with a consideration of lateral heat conduction. In the present study, the effect of the transverse power distribution on the fuel temperature is investigated. The transverse power distributions with variation of fuel segment number are evaluated. The maximum power peaking with 12 segments is higher than that with 4 segments. Based on the calculation, 6-order polynomial is generated to express the transverse power distributions. The maximum power peaking factor increases with segments. The averaged power peaking is 2.10, and the maximum power peaking with 18 segments is 2.80. With the uniform power distribution, the maximum fuel temperature is found in the middle of the fuel. As the power near the side ends of the fuel increases, the maximum fuel temperature is found near the side ends. However, the maximum fuel temperature is not found where the maximum transverse power is. This is because the high power locally released from the edge of the fuel is laterally conducted to the cladding. As a result of the present study, it can be concluded that the effect of the high power peaking at the edge of the fuel on the fuel outer wall temperature is not significant

  14. Effects of MDMA on body temperature in humans

    Science.gov (United States)

    Liechti, Matthias E

    2014-01-01

    Hyperthermia is a severe complication associated with the recreational use of 3,4-methylenedioxymethamphetamine (MDMA, Ecstasy). In this review, the clinical laboratory studies that tested the effects of MDMA on body temperature are summarized. The mechanisms that underlie the hyperthermic effects of MDMA in humans and treatment of severe hyperthermia are presented. The data show that MDMA produces an acute and dose-dependent rise in core body temperature in healthy subjects. The increase in body temperature is in the range of 0.2-0.8°C and does not result in hyperpyrexia (>40°C) in a controlled laboratory setting. However, moderately hyperthermic body temperatures >38.0°C occur frequently at higher doses, even in the absence of physical activity and at room temperature. MDMA primarily releases serotonin and norepinephrine. Mechanistic clinical studies indicate that the MDMA-induced elevations in body temperature in humans partially depend on the MDMA-induced release of norepinephrine and involve enhanced metabolic heat generation and cutaneous vasoconstriction, resulting in impaired heat dissipation. The mediating role of serotonin is unclear. The management of sympathomimetic toxicity and associated hyperthermia mainly includes sedation with benzodiazepines and intravenous fluid replacement. Severe hyperthermia should primarily be treated with additional cooling and mechanical ventilation. PMID:27626046

  15. Temperature effects on hospital admissions for kidney morbidity in Taiwan

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Yu-Kai [Department of Environmental Health, Harvard School of Public Health, 665 Huntington Avenue, Boston, MA 02115 (United States); Wang, Yu-Chun [Department of Bioenvironmental Engineering, College of Engineering, Chung Yuan Christian University, 200 Chung-Pei Road, Chung Li 320, Taiwan (China); Research Center for Environmental Risk Management, Chung Yuan Christian University, 200 Chung-Pei Road, Chung Li 320, Taiwan (China); Ho, Tsung-Jung [The Division of Chinese Medicine, China Medical University Beigang Hospital, Taiwan (China); School Of Chinese Medicine, College of Chinese Medicine, China Medical University, 91 Xueshi Road, Taichung City 404, Taiwan (China); Lu, Chensheng, E-mail: cslu@hsph.harvard.edu [Department of Environmental Health, Harvard School of Public Health, 665 Huntington Avenue, Boston, MA 02115 (United States)

    2013-01-15

    Objective: This study aimed to associate hospital admissions of kidney diseases with extreme temperature and prolonged heat/cold events in 7 regions of Taiwan. Methods: Age-specific (< 65 years, 65 + years and all ages) hospital admission records of nephritis, nephrotic syndrome, or nephrosis, in the form of electronic insurance reimbursement claims, were retrieved from Taiwan's National Health Insurance Research Database during the period of 2000–2008. The area–age-specific relative risk (RR) accounting for 8 days of lag for temperature on hospital admissions of kidney diseases were estimated using distributed lag non-linear models with the Poisson distribution controlling for extreme temperature events, levels of air pollutants (PM{sub 10}, O{sub 3}, and NO{sub 2}) and potential confounders. Results: We observed a V or J-shape association between daily average temperatures and the RR estimates for hospital admissions of kidney diseases in Taiwan. The lowest risk for hospital admissions of kidney diseases was found at around 25 °C, and risk increased as temperatures deviated from 25 °C. The pooled cumulative 8-day RR for all ages of population of the 7 study areas were 1.10 (95% confidence interval (CI): 1.01, 1.19) at 18 °C and 1.45 (95% CI: 1.27, 1.64) at 30 °C. High temperature has more profound influence on hospital admission of kidney diseases than low temperature. Temperature risks for hospital admissions were similar between younger (< 65 years) and elderly (65 + years) population. This study observed no significant effects of prolonged heat extremes on hospital admissions of kidney diseases. Conclusions: The heat effect for kidney morbidities leading to hospital admission was more significant than that of the cold temperature. This study did not find the age-dependent relative risks for temperature associating with hospital admissions of kidney diseases. - Highlights: ► V or J-shaped association was observed between daily temperatures and

  16. Effect of temperature on tribological properties of palm biodiesel

    Energy Technology Data Exchange (ETDEWEB)

    Haseeb, A.S.M.A.; Sia, S.Y.; Fazal, M.A.; Masjuki, H.H. [Department of Mechanical Engineering, University of Malaya, 50603 Kuala Lumpur (Malaysia)

    2010-03-15

    Biodiesel, as an alternative fuel is steadily gaining attention to replace petroleum diesel partially or completely. The tribological performance of biodiesel is crucial for its application in automobiles. In the present study, effect of temperature on the tribological performance of palm biodiesel was investigated by using four ball wear machine. Tests were conducted at temperatures 30, 45, 60 and 75 C, under a normal load of 40 kg for 1 h at speed 1200 rpm. For each temperature, the tribological properties of petroleum diesel (B0) and three biodiesel blends like B10, B20, B50 were investigated and compared. During the wear test, frictional torque was recorded on line. Wear scars in tested ball were investigated by optical microscopy. Results show that friction and wear increase with increasing temperature. (author)

  17. Remote sensing of land surface temperature: The directional viewing effect

    International Nuclear Information System (INIS)

    Smith, J.A.; Schmugge, T.J.; Ballard, J.R. Jr.

    1997-01-01

    Land Surface Temperature (LST) is an important parameter in understanding global environmental change because it controls many of the underlying processes in the energy budget at the surface and heat and water transport between the surface and the atmosphere. The measurement of LST at a variety of spatial and temporal scales and extension to global coverage requires remote sensing means to achieve these goals. Land surface temperature and emissivity products are currently being derived from satellite and aircraft remote sensing data using a variety of techniques to correct for atmospheric effects. Implicit in the commonly employed approaches is the assumption of isotropy in directional thermal infrared exitance. The theoretical analyses indicate angular variations in apparent infrared temperature will typically yield land surface temperature errors ranging from 1 to 4 C unless corrective measures are applied

  18. Pressure effects on high temperature steam oxidation of Zircaloy-4

    International Nuclear Information System (INIS)

    Park, Kwangheon; Kim, Kwangpyo; Ryu, Taegeun

    2000-01-01

    The pressure effects on Zircaloy-4 (Zry-4) cladding in high temperature steam have been analyzed. A double layer autoclave was made for the high pressure, high temperature oxidation tests. The experimental test temperature range was 700 - 900 deg C, and pressures were 0.1 - 15 MPa. Steam partial pressure turns out to be an important one rather than total pressure. Steam pressure enhances the oxidation rate of Zry-4 exponentially. The enhancement depends on the temperature, and the maximum exists between 750 - 800 deg C. Pre-existing oxide layer decreases the enhancement about 40 - 60%. The acceleration of oxidation rate by high pressure team seems to be originated from the formation of cracks by abrupt transformation of tetragonal phase in oxide, where the un-stability of tetragonal phase comes from the reduction of surface energy by steam. (author)

  19. Simulating the moderating effect of a lake on downwind temperatures

    Science.gov (United States)

    Bill, R. G., Jr.; Chen, E.; Sutherland, R. A.; Bartholic, J. F.

    1979-01-01

    A steady-state, two-dimensional numerical model is used to simulate air temperatures and humidity downwind of a lake at night. Thermal effects of the lake were modelled for the case of moderate and low surface winds under the cold-air advective conditions that occur following the passage of a cold front. Surface temperatures were found to be in good agreement with observations. A comparison of model results with thermal imagery indicated the model successfully predicts the downwind distance for which thermal effects due to the lake are significant.

  20. Effects of temperature and relative humidity on DNA methylation.

    Science.gov (United States)

    Bind, Marie-Abele; Zanobetti, Antonella; Gasparrini, Antonio; Peters, Annette; Coull, Brent; Baccarelli, Andrea; Tarantini, Letizia; Koutrakis, Petros; Vokonas, Pantel; Schwartz, Joel

    2014-07-01

    Previous studies have found relationships between DNA methylation and various environmental contaminant exposures. Associations with weather have not been examined. Because temperature and humidity are related to mortality even on non-extreme days, we hypothesized that temperature and relative humidity may affect methylation. We repeatedly measured methylation on long interspersed nuclear elements (LINE-1), Alu, and 9 candidate genes in blood samples from 777 elderly men participating in the Normative Aging Study (1999-2009). We assessed whether ambient temperature and relative humidity are related to methylation on LINE-1 and Alu, as well as on genes controlling coagulation, inflammation, cortisol, DNA repair, and metabolic pathway. We examined intermediate-term associations of temperature, relative humidity, and their interaction with methylation, using distributed lag models. Temperature or relative humidity levels were associated with methylation on tissue factor (F3), intercellular adhesion molecule 1 (ICAM-1), toll-like receptor 2 (TRL-2), carnitine O-acetyltransferase (CRAT), interferon gamma (IFN-γ), inducible nitric oxide synthase (iNOS), and glucocorticoid receptor, LINE-1, and Alu. For instance, a 5°C increase in 3-week average temperature in ICAM-1 methylation was associated with a 9% increase (95% confidence interval: 3% to 15%), whereas a 10% increase in 3-week average relative humidity was associated with a 5% decrease (-8% to -1%). The relative humidity association with ICAM-1 methylation was stronger on hot days than mild days. DNA methylation in blood cells may reflect biological effects of temperature and relative humidity. Temperature and relative humidity may also interact to produce stronger effects.

  1. Effect of In-Situ Cure on Measurement of Glass Transition Temperatures in High-Temperature Thermosetting Polymers (Briefing Charts)

    Science.gov (United States)

    2015-05-20

    TEMPERATURES IN HIGH-TEMPERATURE THERMOSETTING POLYMERS 5a. CONTRACT NUMBER In-House 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d...temperature thermosetting polymer via dynamic mechanical analysis alone. These difficulties result from the residual cure of samples heated beyond their...98) Prescribed by ANSI Std. 239.18 Effect of In-Situ Cure on Measurement of Glass Transition Temperatures in High-Temperature Thermosetting

  2. Temperature Effects of Dielectric Properties of ER Fluids

    Science.gov (United States)

    Qiu, Z. Y.; Hu, L.; Liu, M. W.; Bao, H. X.; Jiang, Y. G.; Zhou, L. W.; Tang, Y.; Gao, Z.; Sun, M.; Korobko, E. V.

    Under the consideration of the role that energy transfer and dissipation play in ER effect, an improved theory frame for ER effects, polarization-dissipation-structure-rheology, is suggested. The theory frame is substantiated by the basic physical laws and certain critical experimental facts. The dielectric response of a diatomite ER fluid to temperature is measured in the temperature range of 140 K to 400 K. By comparison of the DC conductivity with the AC effective conductivity of the sample, we found that the AC dielectric loss consists of two parts. One part comes from the DC conductivity, the other from the response of the bound charges in scope of particle to AC field. It is suggested that the response of bound charges is very important to ER effects. Besides, the effect of temperature on shear stress is measured, and interpreted based on the dielectric measurements. The source of two loss peaks in the curve of the dielectric loss versus temperature is not clear.

  3. Temperature and Humidity Effects on Hospital Morbidity in Darwin, Australia.

    Science.gov (United States)

    Goldie, James; Sherwood, Steven C; Green, Donna; Alexander, Lisa

    2015-01-01

    Many studies have explored the relationship between temperature and health in the context of a changing climate, but few have considered the effects of humidity, particularly in tropical locations, on human health and well-being. To investigate this potential relationship, this study assessed the main and interacting effects of daily temperature and humidity on hospital admission rates for selected heat-relevant diagnoses in Darwin, Australia. Univariate and bivariate Poisson generalized linear models were used to find statistically significant predictors and the admission rates within bins of predictors were compared to explore nonlinear effects. The analysis indicated that nighttime humidity was the most statistically significant predictor (P < 0.001), followed by daytime temperature and average daily humidity (P < 0.05). There was no evidence of a significant interaction between them or other predictors. The nighttime humidity effect appeared to be strongly nonlinear: Hot days appeared to have higher admission rates when they were preceded by high nighttime humidity. From this analysis, we suggest that heat-health policies in tropical regions similar to Darwin need to accommodate the effects of temperature and humidity at different times of day. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  4. Thermoelectric and thermomagnetic effects in high-temperature superconductors

    International Nuclear Information System (INIS)

    Huebener, R.P.; Ri, H.C.; Gross, R.; Kober, F.

    1992-01-01

    In the mixed state of high-temperature superconductors the dominant part of the Seebeck and Nernst effect is due to the thermal diffusion of quasiparticles and vortices, respectively. The authors' understanding of the Seebeck effect is based on the two-fluid counterflow model of Ginzburg and its extension to the mixed state with the presence of vortices. From the Nernst effect the transport entropy of the vortices is obtained. In this paper summarize the recent thermoelectric and thermomagnetic experiments, paying also attention to the role of the Magnus force (Hall effect) and to the thermal fluctuation effects near T c

  5. Temperature shifts in the Sinai model: static and dynamical effects

    International Nuclear Information System (INIS)

    Sales, Marta; Bouchaud, Jean-Philippe; Ritort, Felix

    2003-01-01

    We study analytically and numerically the role of temperature shifts in the simplest model where the energy landscape is explicitly hierarchical, namely the Sinai model. This model has both attractive features (there are valleys within valleys in a strict self-similar sense), but also one important drawback: there is no phase transition so that the model is, in the large-size limit, effectively at zero temperature. We compute various static chaos indicators, that are found to be trivial in the large-size limit, but exhibit interesting features for finite sizes. Correspondingly, for finite times, some interesting rejuvenation effects, related to the self-similar nature of the potential, are observed. Still, the separation of time scales/length scales with temperature in this model is much weaker than in experimental spin glasses

  6. Temperature effects in an optical limiter using carbon nanotube suspensions

    International Nuclear Information System (INIS)

    Yu, Hyojung; Kim, Sokwon

    2005-01-01

    An optical limiter is an optical component that reduces the laser beam intensity for the protection of eyes and light sensors, and a carbon nanotube is known to be a highly efficient optical limiting material. However, the effects of heat generated by continuous use have not been studied yet. Therefore, in this work, the variation of optical limiting effect of multi-walled carbon-nanotube suspensions in several kinds of solvents such as distilled water, chloroform, ethanol and ethylene glycol, were measured in the temperature range from room temperature to the boiling point of each solvent. A pulsed Nd : YAG laser with a wavelength of 1064 nm and a pulse duration of 6 ns was used as the light source. The experimental result shows that the limiting efficiencies of all the suspensions were reduced as the temperature was increased and that a suspension with a solvent of lower boiling point, viscosity, and surface tension showed a higher efficiency.

  7. Maximum weight of greenhouse effect to global temperature variation

    International Nuclear Information System (INIS)

    Sun, Xian; Jiang, Chuangye

    2007-01-01

    Full text: The global average temperature has risen by 0.74 0 C since the late 19th century. Many studies have concluded that the observed warming in the last 50 years may be attributed to increasing concentrations of anthropogenic greenhouse gases. But some scientists have a different point of view. Global climate change is affected not only by anthropogenic activities, but also constraints in climate system natural factors. How much is the influencing weight of C02's greenhouse effects to the global temperature variation? Does global climate continue warming or decreasing in the next 20 years? They are two hot spots in global climate change. The multi-timescales analysis method - Empirical mode decomposition (EMD) is used to diagnose global annual mean air temperature dataset for land surface provided by IPCC and atmospheric content of C02 provided by the Carbon Dioxide Information Analysis Center (CDIAC) during 1881-2002. The results show that: Global temperature variation contains quasi-periodic oscillations on four timescales (3 yr, 6 yr, 20 yr and 60 yr, respectively) and a century-scale warming trend. The variance contribution of IMF1-IMF4 and trend is 17.55%, 11.34%, 6.77%, 24.15% and 40.19%, respectively. The trend and quasi-60 yr oscillation of temperature variation are the most prominent; C02's greenhouse effect on global temperature variation is mainly century-scale trend. The contribution of C02 concentration to global temperature variability is not more than 40.19%, whereas 59.81% contribution to global temperature variation is non-greenhouse effect. Therefore, it is necessary to re-study the dominant factors that induce the global climate change; It has been noticed that on the periods of 20 yr and 60 yr oscillation, the global temperature is beginning to decreased in the next 20 years. If the present C02 concentration is maintained, the greenhouse effect will be too small to countercheck the natural variation in global climate cooling in the next 20

  8. Effects of emitted electron temperature on the plasma sheath

    International Nuclear Information System (INIS)

    Sheehan, J. P.; Kaganovich, I. D.; Wang, H.; Raitses, Y.; Sydorenko, D.; Hershkowitz, N.

    2014-01-01

    It has long been known that electron emission from a surface significantly affects the sheath surrounding that surface. Typical fluid theory of a planar sheath with emitted electrons assumes that the plasma electrons follow the Boltzmann relation and the emitted electrons are emitted with zero energy and predicts a potential drop of 1.03T e /e across the sheath in the floating condition. By considering the modified velocity distribution function caused by plasma electrons lost to the wall and the half-Maxwellian distribution of the emitted electrons, it is shown that ratio of plasma electron temperature to emitted electron temperature significantly affects the sheath potential when the plasma electron temperature is within an order of magnitude of the emitted electron temperature. When the plasma electron temperature equals the emitted electron temperature the emissive sheath potential goes to zero. One dimensional particle-in-cell simulations corroborate the predictions made by this theory. The effects of the addition of a monoenergetic electron beam to the Maxwellian plasma electrons were explored, showing that the emissive sheath potential is close to the beam energy only when the emitted electron flux is less than the beam flux

  9. Effects of Sintering Temperature on the Density And Porosity of ...

    African Journals Online (AJOL)

    Effects of sintering temperature on the density and porosity of sodium chloride preforms for alu- minium foam manufacturing have been investigated. Cold pressed salt preforms were sintered at 30, 760 and 790 and di erent times ranging between 6- 18 hours in a carbolite furnace at a heating rate of 5/minute. The Results of ...

  10. The effects of incubation period and temperature on the Hydrogen ...

    African Journals Online (AJOL)

    The effects of incubation period and temperature on the Hydrogen sulphide (H 2 S) technique for detection of faecal contamination in water. ... African Journal of Environmental Science and Technology. Journal Home ... A total of 171 water samples from 3 sources were analyzed for the presence of faecal contamination by

  11. Effects of temperature on biological activity of permafrost microorganisms.

    Science.gov (United States)

    Kalyonova, L F; Novikova, M A; Subbotin, A M; Bazhin, A S

    2015-04-01

    The number and viability of microorganism specimens Bacillus spp. isolated from permafrost soil remained unchanged after incubation at temperatures of -16-37°C. Experiments on F1 CBA/Black-6 mice showed that incubation of bacteria at -5°C for 72 h promotes a decrease in their toxicity and an increase in their immunostimulating effect.

  12. Effect of temperature and salinity on germination of Achillea ...

    African Journals Online (AJOL)

    Achillea fragrantissima and Moringa peregrina are dominant plants in the mountainous desert of Saudi Arabia. The two species suffer from intensive anthropogenic pressures as they have important medicinal uses. This paper aimed to evaluate the effect of temperature and salinity on germination of A. fragrantissima and M.

  13. Main and interaction effects of extrusion temperature and usage ...

    African Journals Online (AJOL)

    The extruded full fat soybean (EFFSB) may be used in diet to satisfy the energy and protein requirements of fast growing broiler chickens. The main and interaction effects of three extrusion temperatures and two dietary levels of FFSB were studied on the performance, physiological enzymes and blood metabolites of broiler ...

  14. Effects of Hot Water Treatment and Temperature on Seedling ...

    African Journals Online (AJOL)

    An experiment was conducted at the Faculty of Agriculture, University of Maiduguri, to study the effect of hot water treatment and temperature on the morphological characteristics of Arabic gum. The experiment was laid out in a Randomized Complete Block Design in a factorial arrangement. The treatments included a ...

  15. Effect of temperature on structure and corrosion resistance for ...

    Indian Academy of Sciences (India)

    The effect of plating temperatures between 60 and 90◦C on structure and corrosion resistance for elec- troless NiWP coatings ..... which helps to form fine grain. At 80 .... [23] Zhang W X, Jiang Z H, Li G Y and Jiang Q 2008 Surf. Coat. Technol.

  16. "Deflategate": Time, Temperature, and Moisture Effects on Football Pressure

    Science.gov (United States)

    Blumenthal, Jack; Beljak, Lauren; Macatangay, Dahlia-Marie; Helmuth-Malone, Lilly; McWilliams, Catharina; Raptis, Sofia

    2016-01-01

    In a recent paper in "The Physics Teacher (TPT)", DiLisi and Rarick used the National Football League "Deflategate" controversy to introduce to physics students the physics of a bouncing ball. In this paper, we measure and analyze the environmental effects of time, ambient temperature, and moisture on the internal pressure of…

  17. Surface and temperature effects in isovector giant resonances

    International Nuclear Information System (INIS)

    Lipparini, E.; Stringari, S.

    1988-01-01

    Using the liquid droplet model (LDM) we investigate three different sum rules for the isovector dipole and monopole excitations. Analytical formulae are derived for the excitation energies of these resonances and the predictions are compared with experiments. The role of the surface and the effects of temperature are explicitly discussed. (orig.)

  18. Effect of sintering temperature on structural and electrical properties ...

    Indian Academy of Sciences (India)

    TECS

    to reduce the operating temperature, two approaches are widely applied. ... simple and cost-effective method, is often adopted to pre- pare bulk ... The lattice parameter 'a' was calculated using the relation. 2. 2. 2 ,. a d h k l. = ⋅. +. +. (1).

  19. Statistical analysis of the effects of relative humidity and temperature ...

    African Journals Online (AJOL)

    Meteorological data from the Department of Satellite Application Facility on Climate Monitoring (CMSAF), DWD Germany have been used to study and investigate the effect of relative humidity and temperature on refractivity in twenty six locations grouped into for climatic regions aloft Nigeria (Coastal, Guinea savannah, ...

  20. Effect of temperature on accumulation of chlorophylls and leaf ...

    African Journals Online (AJOL)

    White young shoots from albino tea cultivars have high level of amino acids and are rare and valuable materials for processing green tea. The effects of temperature on leaf colour, accumulation of chlorophylls and leaf ultrastructures of an albino tea cultivar 'Xiaxueya' were investigated. The study showed that the shoot ...

  1. Effect of Calcination and Reduction Temperatures on the Reduction ...

    African Journals Online (AJOL)

    2003-12-05

    Dec 5, 2003 ... the catalyst activity. The results obtained by Rathousky et al.,9 however, revealed that the pretreatment conditions had a significant effect on the catalytic properties of Co/Al2O3 and. Co/SiO2 catalysts. Turnover frequency (TOF) for the F-T reaction decreased with increasing calcination temperature for both.

  2. The effects of Mg incorporation and annealing temperature on the ...

    Indian Academy of Sciences (India)

    Home; Journals; Pramana – Journal of Physics; Volume 88; Issue 2. The effects of Mg incorporation and annealing temperature on the physicochemical properties and antibacterial activity against {\\it Listeria monocytogenes} of ZnO nanoparticles. NIMA SHADAN ALI ABDOLAHZADEH ZIABARI RAFIEH MERAAT KAMYAR ...

  3. Effect of repository underground ventilation on emplacement drift temperature control

    International Nuclear Information System (INIS)

    Yang, H.; Sun, Y.; McKenzie, D.G.; Bhattacharyya, K.K.

    1996-01-01

    The repository advanced conceptual design (ACD) is being conducted by the Civilian Radioactive Waste Management System, Management ampersand Operating Contractor. Underground ventilation analyses during ACD have resulted in preliminary ventilation concepts and design methodologies. This paper discusses one of the recent evaluations -- effects of ventilation on emplacement drift temperature management

  4. Effect of sintering temperature and heating mode on consolidation of ...

    Indian Academy of Sciences (India)

    ratures ranging from 570–630 ◦C. Microwave sintering at a heating rate of as high as 22◦. C/min resulted in ... The effect of heating mode and sintering temperature are discussed .... the compacts. This is attributed to the Zn evaporated from the.

  5. Effects of Different Temperatures for Drying Cervical Mucus Smear ...

    African Journals Online (AJOL)

    The effects of different room temperatures for drying cervical mucus on crystallisation of fern-tree patterns was determined using cervical mucus smears from 60 women undergoing investigation for infertility at the University of Benin Teaching Hospital. Cervical mucus smears were dried in the oven at 15, 20, 25, 30 and 35C ...

  6. Effect of heat treatment temperature on binder thermal conductivities

    International Nuclear Information System (INIS)

    Wagner, P.

    1975-12-01

    The effect of heat treatment on the thermal conductivities of a pitch and a polyfurfuryl alcohol binder residue was investigated. Graphites specially prepared with these two binders were used for the experiments. Measured thermal conductivities were treated in terms of a two-component system, and the binder thermal conductivities were calculated. Both binder residues showed increased thermal conductivity with increased heat treatment temperature

  7. Effect of Temperature and Relative Humidity on the Growth of ...

    African Journals Online (AJOL)

    were used to determine the temperature effect on the growth of H. fulvum. Maximum growth of H. ... The fungus showed maximum growth at 92.5 and 100% relative humidity. .... recommended that fruits and vegetables should be stored at low ...

  8. Effect of peritoneal lavage solution temperature on body temperature in anaesthetised cats and small dogs.

    Science.gov (United States)

    Barnes, D C; Leece, E A; Trimble, T A; Demetriou, J L

    2017-05-20

    A prospective, randomised, non-blinded, clinical study to assess the effect of peritoneal lavage using warmed fluid on body temperature in anesthetised cats and dogs of less than 10 kg body mass undergoing coeliotomy. A standardised anaesthetic protocol was used. Oesophageal and rectal temperatures were measured at various time points. At the end of surgery, group 1 patients (n=10) were lavaged with 200 ml/kg sterile isotonic saline at 34±1°C and group 2 (n=10) at 40±1°C. Groups were similar with respect to age, mass, body condition and surgical incision length. Duration of anaesthesia, surgical procedures and peritoneal lavage was similar between groups. Linear regression showed no significant change in oesophageal temperature during the lavage period for group 1 (P=0.64), but a significant increase for group 2 patients (Ptemperature changes of -0.5°C (from (36.3°C to 35.9°C) and +0.9°C (from 35.4°C to 36.3°C), respectively. Similar results were found for rectal temperature, with mean changes of -0.5°C and +0.8°C (P=0.922 and 0.045), respectively. The use of isotonic crystalloid solution for peritoneal lavage at a temperature of 40±1°C significantly warms small animal patients, when applied in a clinical setting, compared with lavage solution at 34±1°C. British Veterinary Association.

  9. Effects of CO2 and temperature on tritrophic interactions.

    Directory of Open Access Journals (Sweden)

    Lee A Dyer

    Full Text Available There has been a significant increase in studies of how global change parameters affect interacting species or entire communities, yet the combined or interactive effects of increased atmospheric CO2 and associated increases in global mean temperatures on chemically mediated trophic interactions are mostly unknown. Thus, predictions of climate-induced changes on plant-insect interactions are still based primarily on studies of individual species, individual global change parameters, pairwise interactions, or parameters that summarize communities. A clear understanding of community response to global change will only emerge from studies that examine effects of multiple variables on biotic interactions. We examined the effects of increased CO2 and temperature on simple laboratory communities of interacting alfalfa, chemical defense, armyworm caterpillars, and parasitoid wasps. Higher temperatures and CO2 caused decreased plant quality, decreased caterpillar development times, developmental asynchrony between caterpillars and wasps, and complete wasp mortality. The effects measured here, along with other effects of global change on natural enemies suggest that biological control and other top-down effects of insect predators will decline over the coming decades.

  10. Thermal contraction effects in epoxy resin composites at low temperatures

    International Nuclear Information System (INIS)

    Evans, D.; Morgan, J.T.

    1979-10-01

    Because of their electrical and thermal insulation characteristics, high strength fibreglass/epoxy composites are widely used in the construction of bubble chamber and other cryogenic equipment. Thermal contraction effects on cooling to operating temperature present problems which need to be taken into account at the design stage. This paper gives results of thermal contraction tests carried out on fibreglass/epoxy composites including the somewhat anomalous results obtained with rings and tubes. Also considered are some of the problems associated with the use of these materials at temperatures in the region of 20K. (author)

  11. Effects of temperature on SCC propagation in high temperature water injected with hydrogen peroxide

    International Nuclear Information System (INIS)

    Nakano, Junichi; Sato, Tomonori; Kato, Chiaki; Yoshiyuki, Kaji; Yamamoto, Masahiro; Tsukada, Takashi

    2012-09-01

    To understand the stress corrosion cracking (SCC) behaviour of austenitic stainless steels (SSs) in the boiling water reactor (BWR) coolant environment, it is significant to investigate the effect of hydrogen peroxide (H 2 O 2 ) produced by the radiolysis of water on SCC under the various water chemistry and operational conditions. At the start-up or shut-down periods, for example, the conditions of radiation and temperature on the structural materials are different from those during the plant normal operation, and may be influencing on SCC behaviour. Therefore, the effect of temperature on SCC in high temperature water injected with H 2 O 2 was evaluated by SCC propagation test at the present study. Oxide films on the metal surface in crack were examined and the thermal equilibrium diagram was calculated to estimate the environmental situation in the crack. On the thermally sensitized type 304 SS, crack growth tests were conducted in high temperature water injected with H 2 O 2 to simulate water radiolysis in the core. Small CT type specimens with a width of 15.5 mm and thickness of 6.2 mm were machined from the sensitized SS. SCC growth tests were conducted in high temperature water injected with 100 ppb H 2 O 2 at 453 and 561 K. To minimize H 2 O 2 decomposition by a contact with metal surface of autoclave, the CT specimen was isolated from inner surface of the autoclave by the inner modules made of polytetrafluoroethylene (PTFE), and PTFE lining was also used for the inner surface of inlet and sampling tubes. Base on the measurement of sampled water, it was confirmed that 80-90 % of injected H 2 O 2 remained around the CT specimen in autoclave. Constant load at initial K levels of 11-20 MPam 1/2 was applied to the CT specimens during crack growth tests. After crack growth tests, CT specimens were split into two pieces on the plane of crack propagation. Scanning electron microscope (SEM) examination and laser Raman spectroscopy for outer oxide layer of oxide

  12. Temperature Effects Explain Continental Scale Distribution of Cyanobacterial Toxins.

    Science.gov (United States)

    Mantzouki, Evanthia; Lürling, Miquel; Fastner, Jutta; de Senerpont Domis, Lisette; Wilk-Woźniak, Elżbieta; Koreivienė, Judita; Seelen, Laura; Teurlincx, Sven; Verstijnen, Yvon; Krztoń, Wojciech; Walusiak, Edward; Karosienė, Jūratė; Kasperovičienė, Jūratė; Savadova, Ksenija; Vitonytė, Irma; Cillero-Castro, Carmen; Budzyńska, Agnieszka; Goldyn, Ryszard; Kozak, Anna; Rosińska, Joanna; Szeląg-Wasielewska, Elżbieta; Domek, Piotr; Jakubowska-Krepska, Natalia; Kwasizur, Kinga; Messyasz, Beata; Pełechaty, Aleksandra; Pełechaty, Mariusz; Kokocinski, Mikolaj; García-Murcia, Ana; Real, Monserrat; Romans, Elvira; Noguero-Ribes, Jordi; Duque, David Parreño; Fernández-Morán, Elísabeth; Karakaya, Nusret; Häggqvist, Kerstin; Demir, Nilsun; Beklioğlu, Meryem; Filiz, Nur; Levi, Eti E.; Iskin, Uğur; Bezirci, Gizem; Tavşanoğlu, Ülkü Nihan; Özhan, Koray; Gkelis, Spyros; Panou, Manthos; Fakioglu, Özden; Avagianos, Christos; Kaloudis, Triantafyllos; Çelik, Kemal; Yilmaz, Mete; Marcé, Rafael; Catalán, Nuria; Bravo, Andrea G.; Buck, Moritz; Colom-Montero, William; Mustonen, Kristiina; Pierson, Don; Yang, Yang; Raposeiro, Pedro M.; Gonçalves, Vítor; Antoniou, Maria G.; Tsiarta, Nikoletta; McCarthy, Valerie; Perello, Victor C.; Feldmann, Tõnu; Laas, Alo; Panksep, Kristel; Tuvikene, Lea; Gagala, Ilona; Mankiewicz-Boczek, Joana; Yağcı, Meral Apaydın; Çınar, Şakir; Çapkın, Kadir; Yağcı, Abdulkadir; Cesur, Mehmet; Bilgin, Fuat; Bulut, Cafer; Uysal, Rahmi; Obertegger, Ulrike; Boscaini, Adriano; Flaim, Giovanna; Salmaso, Nico; Cerasino, Leonardo; Richardson, Jessica; Visser, Petra M.; Verspagen, Jolanda M. H.; Karan, Tünay; Soylu, Elif Neyran; Maraşlıoğlu, Faruk; Napiórkowska-Krzebietke, Agnieszka; Ochocka, Agnieszka; Pasztaleniec, Agnieszka; Antão-Geraldes, Ana M.; Vasconcelos, Vitor; Morais, João; Vale, Micaela; Köker, Latife; Akçaalan, Reyhan; Albay, Meriç; Špoljarić Maronić, Dubravka; Stević, Filip; Žuna Pfeiffer, Tanja; Fonvielle, Jeremy; Straile, Dietmar; Rothhaupt, Karl-Otto; Hansson, Lars-Anders; Urrutia-Cordero, Pablo; Bláha, Luděk; Geriš, Rodan; Fránková, Markéta; Koçer, Mehmet Ali Turan; Alp, Mehmet Tahir; Remec-Rekar, Spela; Elersek, Tina; Triantis, Theodoros; Zervou, Sevasti-Kiriaki; Hiskia, Anastasia; Haande, Sigrid; Skjelbred, Birger; Madrecka, Beata; Nemova, Hana; Drastichova, Iveta; Chomova, Lucia; Edwards, Christine; Sevindik, Tuğba Ongun; Tunca, Hatice; Önem, Burçin; Aleksovski, Boris; Krstić, Svetislav; Vucelić, Itana Bokan; Nawrocka, Lidia; Salmi, Pauliina; Machado-Vieira, Danielle; de Oliveira, Alinne Gurjão; Delgado-Martín, Jordi; García, David; Cereijo, Jose Luís; Gomà, Joan; Trapote, Mari Carmen; Vegas-Vilarrúbia, Teresa; Obrador, Biel; Grabowska, Magdalena; Karpowicz, Maciej; Chmura, Damian; Úbeda, Bárbara; Gálvez, José Ángel; Özen, Arda; Christoffersen, Kirsten Seestern; Warming, Trine Perlt; Kobos, Justyna; Mazur-Marzec, Hanna; Pérez-Martínez, Carmen; Ramos-Rodríguez, Eloísa; Arvola, Lauri; Alcaraz-Párraga, Pablo; Toporowska, Magdalena; Pawlik-Skowronska, Barbara; Niedźwiecki, Michał; Pęczuła, Wojciech; Leira, Manel; Hernández, Armand; Moreno-Ostos, Enrique; Blanco, José María; Rodríguez, Valeriano; Montes-Pérez, Jorge Juan; Palomino, Roberto L.; Rodríguez-Pérez, Estela; Carballeira, Rafael; Camacho, Antonio; Picazo, Antonio; Rochera, Carlos; Santamans, Anna C.; Ferriol, Carmen; Romo, Susana; Soria, Juan Miguel; Dunalska, Julita; Sieńska, Justyna; Szymański, Daniel; Kruk, Marek; Kostrzewska-Szlakowska, Iwona; Jasser, Iwona; Žutinić, Petar; Gligora Udovič, Marija; Plenković-Moraj, Anđelka; Frąk, Magdalena; Bańkowska-Sobczak, Agnieszka; Wasilewicz, Michał; Özkan, Korhan; Maliaka, Valentini; Kangro, Kersti; Grossart, Hans-Peter; Paerl, Hans W.; Carey, Cayelan C.; Ibelings, Bas W.

    2018-04-13

    Insight into how environmental change determines the production and distribution of cyanobacterial toxins is necessary for risk assessment. Management guidelines currently focus on hepatotoxins (microcystins). Increasing attention is given to other classes, such as neurotoxins (e.g., anatoxin-a) and cytotoxins (e.g., cylindrospermopsin) due to their potency. Most studies examine the relationship between individual toxin variants and environmental factors, such as nutrients, temperature and light. In summer 2015, we collected samples across Europe to investigate the effect of nutrient and temperature gradients on the variability of toxin production at a continental scale. Direct and indirect effects of temperature were the main drivers of the spatial distribution in the toxins produced by the cyanobacterial community, the toxin concentrations and toxin quota. Generalized linear models showed that a Toxin Diversity Index (TDI) increased with latitude, while it decreased with water stability. Increases in TDI were explained through a significant increase in toxin variants such as MC-YR, anatoxin and cylindrospermopsin, accompanied by a decreasing presence of MC-LR. While global warming continues, the direct and indirect effects of increased lake temperatures will drive changes in the distribution of cyanobacterial toxins in Europe, potentially promoting selection of a few highly toxic species or strains.

  13. Effect of temperature on biodegradation of crude oil

    International Nuclear Information System (INIS)

    Zekri, A.; Chaalal, O.

    2005-01-01

    An active strain of anaerobic thermophilic bacteria was isolated from the environment of the United Arab Emirates. This project studied the effect of temperature, salinity and oil concentration on biodegradation of crude oil. Oil weight loss, microbial growth and the changes of the crude oil asphaltene concentration are used to evaluate the oil degradation by this strain. A series of batch experiments was performed to study the effects of bacteria on the degradation of crude oil. The effects of oil concentration, bacteria concentration, temperature and salinity on the biodegradation were investigated. The temperatures of the studied systems were varied between 35 and 75 o C and the salt concentrations were varied between 0 and 10%. Oil concentrations were ranged from 5 to 50% by volume. Experimental work showed the bacteria employed in this project were capable of surviving the harsh environment and degrading the crude oil at various conditions. Increasing the temperature increases the rate of oil degradation by bacteria. Increasing the oil concentration in general decreases the rate of bacteria oil degradation. Salinity plays a major role on the acceleration of biodegradation process of crude oil. An optimum salinity should be determined for every studied system. The finding of this project could be used in either the treatment of oil spill or in-situ stimulation of heavy oil wells. (author)

  14. Effects of temperature changes on maize production in Mozambique

    Science.gov (United States)

    Harrison, L.; Michaelsen, J.; Funk, Chris; Husak, G.

    2011-01-01

    We examined intraseasonal changes in maize phenology and heat stress exposure over the 1979-2008 period, using Mozambique meteorological station data and maize growth requirements in a growing degree-day model. Identifying historical effects of warming on maize growth is particularly important in Mozambique because national food security is highly dependent on domestic food production, most of which is grown in already warm to hot environments. Warming temperatures speed plant development, shortening the length of growth periods necessary for optimum plant and grain size. This faster phenological development also alters the timing of maximum plant water demand. In hot growing environments, temperature increases during maize pollination threaten to make midseason crop failure the norm. In addition to creating a harsher thermal environment, we find that early season temperature increases have caused the maize reproductive period to start earlier, increasing the risk of heat and water stress. Declines in time to maize maturation suggest that, independent of effects to water availability, yield potential is becoming increasingly limited by warming itself. Regional variations in effects are a function of the timing and magnitude of temperature increases and growing season characteristics. Continuation of current climatic trends could induce substantial yield losses in some locations. Farmers could avoid some losses through simple changes to planting dates and maize varietal types.

  15. Temperature Effects Explain Continental Scale Distribution of Cyanobacterial Toxins

    Directory of Open Access Journals (Sweden)

    Evanthia Mantzouki

    2018-04-01

    Full Text Available Insight into how environmental change determines the production and distribution of cyanobacterial toxins is necessary for risk assessment. Management guidelines currently focus on hepatotoxins (microcystins. Increasing attention is given to other classes, such as neurotoxins (e.g., anatoxin-a and cytotoxins (e.g., cylindrospermopsin due to their potency. Most studies examine the relationship between individual toxin variants and environmental factors, such as nutrients, temperature and light. In summer 2015, we collected samples across Europe to investigate the effect of nutrient and temperature gradients on the variability of toxin production at a continental scale. Direct and indirect effects of temperature were the main drivers of the spatial distribution in the toxins produced by the cyanobacterial community, the toxin concentrations and toxin quota. Generalized linear models showed that a Toxin Diversity Index (TDI increased with latitude, while it decreased with water stability. Increases in TDI were explained through a significant increase in toxin variants such as MC-YR, anatoxin and cylindrospermopsin, accompanied by a decreasing presence of MC-LR. While global warming continues, the direct and indirect effects of increased lake temperatures will drive changes in the distribution of cyanobacterial toxins in Europe, potentially promoting selection of a few highly toxic species or strains.

  16. On effective temperature in network models of collective behavior

    International Nuclear Information System (INIS)

    Porfiri, Maurizio; Ariel, Gil

    2016-01-01

    Collective behavior of self-propelled units is studied analytically within the Vectorial Network Model (VNM), a mean-field approximation of the well-known Vicsek model. We propose a dynamical systems framework to study the stochastic dynamics of the VNM in the presence of general additive noise. We establish that a single parameter, which is a linear function of the circular mean of the noise, controls the macroscopic phase of the system—ordered or disordered. By establishing a fluctuation–dissipation relation, we posit that this parameter can be regarded as an effective temperature of collective behavior. The exact critical temperature is obtained analytically for systems with small connectivity, equivalent to low-density ensembles of self-propelled units. Numerical simulations are conducted to demonstrate the applicability of this new notion of effective temperature to the Vicsek model. The identification of an effective temperature of collective behavior is an important step toward understanding order–disorder phase transitions, informing consistent coarse-graining techniques and explaining the physics underlying the emergence of collective phenomena.

  17. Pseudogap temperature T* of cuprate superconductors from the Nernst effect

    Science.gov (United States)

    Cyr-Choinière, O.; Daou, R.; Laliberté, F.; Collignon, C.; Badoux, S.; LeBoeuf, D.; Chang, J.; Ramshaw, B. J.; Bonn, D. A.; Hardy, W. N.; Liang, R.; Yan, J.-Q.; Cheng, J.-G.; Zhou, J.-S.; Goodenough, J. B.; Pyon, S.; Takayama, T.; Takagi, H.; Doiron-Leyraud, N.; Taillefer, Louis

    2018-02-01

    We use the Nernst effect to delineate the boundary of the pseudogap phase in the temperature-doping phase diagram of hole-doped cuprate superconductors. New data for the Nernst coefficient ν (T ) of YBa2Cu3Oy (YBCO), La1.8 -xEu0.2SrxCuO4 (Eu-LSCO), and La1.6 -xNd0.4SrxCuO4 (Nd-LSCO) are presented and compared with previously published data on YBCO, Eu-LSCO, Nd-LSCO, and La2 -xSrxCuO4 (LSCO). The temperature Tν at which ν /T deviates from its high-temperature linear behavior is found to coincide with the temperature at which the resistivity ρ (T ) deviates from its linear-T dependence, which we take as the definition of the pseudogap temperature T★—in agreement with the temperature at which the antinodal spectral gap detected in angle-resolved photoemission spectroscopy (ARPES) opens. We track T★ as a function of doping and find that it decreases linearly vs p in all four materials, having the same value in the three LSCO-based cuprates, irrespective of their different crystal structures. At low p ,T★ is higher than the onset temperature of the various orders observed in underdoped cuprates, suggesting that these orders are secondary instabilities of the pseudogap phase. A linear extrapolation of T★(p ) to p =0 yields T★(p →0 ) ≃TN (0), the Néel temperature for the onset of antiferromagnetic order at p =0 , suggesting that there is a link between pseudogap and antiferromagnetism. With increasing p ,T★(p ) extrapolates linearly to zero at p ≃pc 2 , the critical doping below which superconductivity emerges at high doping, suggesting that the conditions which favor pseudogap formation also favor pairing. We also use the Nernst effect to investigate how far superconducting fluctuations extend above the critical temperature Tc, as a function of doping, and find that a narrow fluctuation regime tracks Tc, and not T★. This confirms that the pseudogap phase is not a form of precursor superconductivity, and fluctuations in the phase of the

  18. Temperature effects studies in light water reactor lattices

    International Nuclear Information System (INIS)

    Erradi, Lahoussine.

    1982-02-01

    The CREOLE experiments performed in the EOLE critical facility located in the Nuclear Center of CADARACHE - CEA (UO 2 and UO 2 -PuO 2 lattice reactivity temperature coefficient continuous measurements between 20 0 C and 300 0 C; integral measurements by boron equivalent effect in the moderator; water density effects measurements with the use of over cladding aluminium tubes to remove moderator) allow to get an interesting and complete information on the temperature effects in the light water reactor lattices. A very elaborated calcurated scheme using the transport theory and the APOLLO cross sections library, has been developed. The analysed results of the whole lot of experiments show that the discrepancy between theory and experiment strongly depends on the temperature range and on the type of lattices considered. The error is mainly linked with the thermal spectrum effects. A study on the temperature coefficient sensitivity to the different cell neutron parameters has shown that only the shapes of the 235 U and 238 U thermal cross sections have enough weight and uncertainty margins to explain the observed experimental/calculation bias. Instead of arbitrarily fitting the identified wrong data on the calculation of the reactivity temperature coefficient we have defined a procedure of modification of the cross sections based on the consideration of the basic nuclear data: resonance parameters and associated statistic laws. The implementation of this procedure has led to propose new thermal cross sections sets for 235 U and 238 U consistent with the uncertainty margins associated with the previously accepted values and with some experimental data [fr

  19. Pyrolysis temperature influences ameliorating effects of biochars on acidic soil.

    Science.gov (United States)

    Wan, Qing; Yuan, Jin-Hua; Xu, Ren-Kou; Li, Xing-Hui

    2014-02-01

    The biochars were prepared from straws of canola, corn, soybean, and peanut at different temperatures of 300, 500, and 700 °C by means of oxygen-limited pyrolysis.Amelioration effects of these biochars on an acidic Ultisol were investigated with incubation experiments, and application rate of biochars was 10 g/kg. The incorporation of these biochars induced the increase in soil pH, soil exchangeable base cations, base saturation, and cation exchange capacity and the decrease in soil exchangeable acidity and exchangeable Al. The ameliorating effects of biochars on acidic soil increased with increase in their pyrolysis temperature. The contribution of oxygen-containing functional groups on the biochars to their ameliorating effects on the acidic soil decreased with the rise in pyrolysis temperature, while the contribution from carbonates in the biochars changed oppositely. The incorporation of the biochars led to the decrease in soil reactive Al extracted by 0.5mol/L CuCl2, and the content of reactive Al was decreased with the increase in pyrolysis temperature of incorporated biochars. The biochars generated at 300 °C increased soil organically complexed Al due to ample quantity of oxygen-containing functional groups such as carboxylic and phenolic groups on the biochars, while the biochars generated at 500 and 700 °C accelerated the transformation of soil exchangeable Al to hydroxyl-Al polymers due to hydrolysis of Al at higher pH. Therefore, the crop straw-derived biochars can be used as amendments for acidic soils and the biochars generated at relatively high temperature have great ameliorating effects on the soils.

  20. Effect of temperature on swelling and bubble growth in metals

    International Nuclear Information System (INIS)

    Tiwari, G.P.

    1982-01-01

    The effect of temperature on the swelling of copper-boron alloys has been studied in the temperature range of 900-1040deg C. It is observed that beyond 1030deg C, swelling as well as the rate of bubble growth decrease. Similar characteristics of the bubble growth have been observed in aluminium-boron alloys also. At 590deg C, the bubble growth in aluminium-boron alloys is faster as compared to that at 640deg C. It thus appears that the swelling as well as the growth of the gas bubble are retarded at temperatures near the melting point in metals. Possible reasons for this kind of behaviour are discussed. (author)

  1. Finite temperature effects on monopole and dipole excitations

    International Nuclear Information System (INIS)

    Niu, Y F; Paar, N; Vretenar, D; Meng, J

    2011-01-01

    The relativistic random phase approximation based on effective Lagrangian with density dependent meson-nucleon couplings has been extended to finite temperature and employed in studies of multipole excitations within the temperature range T = 1 - 2 MeV. The model calculations showed that isoscalar giant monopole and isovector giant dipole resonances are only slightly modified with temperature, but additional transition strength appears at low energies because of thermal unblocking of single-particle orbitals close to the Fermi level. The analysis of low-lying states shows that isoscalar monopole response in 132 Sn results from single particle transitions, while the isovector dipole strength for 60 Ni, located around 10 MeV, is composed of several single particle transitions, accumulating a small degree of collectivity.

  2. Effect of temperature on crack initiation in gas formed structures

    Energy Technology Data Exchange (ETDEWEB)

    Gohari, S.; Vrcelj, Z.; Sharifi, S.; Sharifishourabi, G.; Abadi, R. [Universiti Teknlogi Malaysia, Skudai (Malaysia)

    2013-12-15

    In the gas forming process, the work piece is formed by applying gas pressure. However, the gas pressure and the accompanying gas temperature can result in crack initiation and unstable crack growth. Thus, it is vital to determine the critical values of applied gas pressure and temperature to avoid crack and fracture failure. We studied the mechanism of fracture using an experimental approach and finite element simulations of a perfect aluminum sheet containing no inclusions and voids. The definition of crack was based on ductile damage mechanics. For inspection of initiation of crack and rupture in gas-metal forming, the ABAQUS/EXPLICIT simulation was used. In gas forming, the applied load is the pressure applied rather than the punching force. The results obtained from both the experimental approach and finite element simulations were compared. The effects of various parameters, such as temperature and gas pressure value on crack initiation, were taken into account.

  3. Simulations of dimensionally reduced effective theories of high temperature QCD

    CERN Document Server

    Hietanen, Ari

    Quantum chromodynamics (QCD) is the theory describing interaction between quarks and gluons. At low temperatures, quarks are confined forming hadrons, e.g. protons and neutrons. However, at extremely high temperatures the hadrons break apart and the matter transforms into plasma of individual quarks and gluons. In this theses the quark gluon plasma (QGP) phase of QCD is studied using lattice techniques in the framework of dimensionally reduced effective theories EQCD and MQCD. Two quantities are in particular interest: the pressure (or grand potential) and the quark number susceptibility. At high temperatures the pressure admits a generalised coupling constant expansion, where some coefficients are non-perturbative. We determine the first such contribution of order g^6 by performing lattice simulations in MQCD. This requires high precision lattice calculations, which we perform with different number of colors N_c to obtain N_c-dependence on the coefficient. The quark number susceptibility is studied by perf...

  4. Effect of high temperature on integrity of concrete containment structures

    International Nuclear Information System (INIS)

    Bhat, P.D.

    1986-01-01

    The effect of high temperature on concrete material properties and structural behavior are studied in order to relate these effects to the performance of concrete containment structures. Salient data obtained from a test program undertaken to study the behavior of a restrained concrete structure under thermal gradient loads up to its ultimate limit are described. The preliminary results indicate that concrete material properties can be considered to remain unaltered up to temperatures of 100 0 C. The presence of thermal gradients did not significantly affect the structures ultimate mechanical load capacity. Relaxation of restraint forces due to creep was found to be an important factor. The test findings are compared with the observations made in available literature. The effect of test findings on the integrity analysis of a containment structure are discussed. The problem is studied from the viewpoint of a CANDU heavy water reactor containment

  5. Irradiation effects of high temperature superconductor of lanthanoid oxides

    Energy Technology Data Exchange (ETDEWEB)

    Ueda, Koh-ichi; Kohara, Takao [Himeji Inst. of Tech., Hyogo (Japan)

    1996-04-01

    Neutron irradiation effects on excess oxygen were studied by neutron irradiation on La{sub 2}CuO{sub 4} treated with high pressure oxygen. La{sub 2}CuO{sub 4} was prepared by the usual method and annealed for 10 h under the oxygen pressure of 800-2000 atm. at 600degC. The superconducting transition temperature (Tc) is 27-32K before irradiation (La{sub 2}CuO{sub 4+d}, amount of excess oxygen d=0.03-0.12). Neutron irradiation was carried out by two kinds of experiments. Low irradiation dose test at low temperature (LTL: {approx}20-200K, storage in LN{sub 2}) showed Tc decreased more slowly than that of high temperature range. Experiment at high temperature (Hyd:{approx}80deg{yields}, storage at room temperature) showed -10K/10{sup 18}n/cm{sup 2}, the decrease of Tc was three times larger than that of YBCO type superconductor. (S.Y.)

  6. Temperature effects on bond between concrete and reinforcing steel

    Directory of Open Access Journals (Sweden)

    Lublóy Éva

    2014-01-01

    Full Text Available Bond behaviour between concrete and reinforcing bars was observed under elevated temperatures. Five different concrete compositions were used. Hundred five pull-out specimens (Ø120 mm, 100 mm were prepared. After removing the specimens from the formwork, they were stored in water for seven days then kept at laboratory conditions until testing. The specimens were 28 days old by testing. After heating up the specimens, they were kept for two hours at these maximum temperatures (20 °C, 150 °C, 300 °C, 400 °C, 500 °C, 800 °C. Specimens were then cooled down in laboratory conditions. Finally the specimens were tested at room temperature. In order to check the compressive strength standard cubes were cast, cured, and heat treated, then tested to compressive strength. The results showed reduction in residual compressive strength and considerable changes in steel-concrete bond under high temperatures. Based on test results, a proposal is presented for the modification of MC2010 bond-ship formula in order to consider temperature effect.

  7. Temperature Effect on Rheological Behavior of Portuguese Honeys

    Directory of Open Access Journals (Sweden)

    Afonso Maria João

    2018-09-01

    Full Text Available In the present work the temperature effect on rheological properties of Portuguese honeys was studied for the first time. Two unifloral honeys – heather and rosemary – and a polyflower honey were analyzed. All honeys showed flow independence over time and behaved as Newtonian fluids at the studied temperature and shear rate ranges. For all honeys it was found that the viscosity decreased with temperature and the rosemary honey was the one that always presented the lowest viscosity at 30°C (6120 mPa·s, 50°C (603 mPa·s and 70°C (145 mPa·s. The temperature dependence of viscosity was well described by the K0×eAT-B$K_0 \\times e^{{A \\over {T - B}}} $ equation. Nevertheless, good regression coefficients were also obtained when fitting the experimental data to the Arrhenius model, showing the rosemary honey to be less temperature sensitive. The results obtained in this study are of great interest to beekeepers and industrials that handle and prepare eatable honey-based products because they will be better informed about the best type of honey to use.

  8. Effect of solvent and temperature on solution-crystallized terfenadine

    International Nuclear Information System (INIS)

    Leitao, M. Luisa P.; Canotilho, Joao; Ferreira, Simone C.R.; Sousa, Adriano T.; Simoes Redinha, J.

    2004-01-01

    The aim of this work was to understand the crystallization process of terfenadine in solution. Cooling of saturated solutions prepared at 50 deg. C at different temperatures, evaporating the solvent from nearly saturated solutions at a certain temperature, and exposing ethanol solutions of terfenadine to water vapour atmosphere were the techniques used for obtaining terfenadine specimens. The characterization of these specimens was carried out by thermal microscopy, differential thermal analysis, thermogravimetry and powder X-ray diffraction. Crystalline phases, amorphous solids, and solvates were identified. For the solvents used in the present study, the crystallinity degree of terfenadine decreases from ethanol-water to ethanol and from this to methanol. Decreasing the temperature promotes the formation of amorphous solid material; at low temperatures, methanol and ethanol solvates are also formed. Desolvation, following the terfenadine aggregation process in solution accounts for the different behaviour found for the solvents and for the effect of temperature on the structure. The role of the solvent as structure-mediator is explained on the grounds of the values previously published for the enthalpy of solution of terfenadine in the solvents under study

  9. Effects of Ambient Temperature and Forced-air Warming on Intraoperative Core Temperature: A Factorial Randomized Trial.

    Science.gov (United States)

    Pei, Lijian; Huang, Yuguang; Xu, Yiyao; Zheng, Yongchang; Sang, Xinting; Zhou, Xiaoyun; Li, Shanqing; Mao, Guangmei; Mascha, Edward J; Sessler, Daniel I

    2018-05-01

    The effect of ambient temperature, with and without active warming, on intraoperative core temperature remains poorly characterized. The authors determined the effect of ambient temperature on core temperature changes with and without forced-air warming. In this unblinded three-by-two factorial trial, 292 adults were randomized to ambient temperatures 19°, 21°, or 23°C, and to passive insulation or forced-air warming. The primary outcome was core temperature change between 1 and 3 h after induction. Linear mixed-effects models assessed the effects of ambient temperature, warming method, and their interaction. A 1°C increase in ambient temperature attenuated the negative slope of core temperature change 1 to 3 h after anesthesia induction by 0.03 (98.3% CI, 0.01 to 0.06) °Ccore/(h°Cambient) (P ambient temperature with passive insulation, but was unaffected by ambient temperature during forced-air warming (0.02 [98.3% CI, -0.04 to 0.09] °Ccore/°Cambient; P = 0.40). After an average of 3.4 h of surgery, core temperature was 36.3° ± 0.5°C in each of the forced-air groups, and ranged from 35.6° to 36.1°C in passively insulated patients. Ambient intraoperative temperature has a negligible effect on core temperature when patients are warmed with forced air. The effect is larger when patients are passively insulated, but the magnitude remains small. Ambient temperature can thus be set to comfortable levels for staff in patients who are actively warmed.

  10. Effects of environment temperature rise on marine life. Bibliographic study

    International Nuclear Information System (INIS)

    Ancellin, J.; Eustache, M.; Vilquin, A.

    1973-12-01

    The effects of a temperature rise in the marine environment resulting from thermal wastes have already been covered by many studies. A body of data acquired on this subject, in the biological field, experimentally and in situ are reviewed. To this are added data concerning the major effects associated with the use of cooling systems, drag effect exerted on organisms by the pumping system and consequences due to the use of anti-fouling substances, as well as some ideas concerning the potential use of thermal wastes in the field of aquaculture [fr

  11. The effective temperatures of early Wolf-Rayet stars

    International Nuclear Information System (INIS)

    Schmutz, W.

    1982-01-01

    Nussbaumer et al. (1981) (NSSW) have calculated temperatures of 15 Wolf-Rayet stars, which cover most subtypes in the WN and WC sequences. Some Wolf-Rayet stars are found to have a blackbody-like energy distribution and therefore their effective temperature can be well determined, others show deviation from the blackbody shape. This deviation is probably due to an extended continuum emitting region. In view of these later cases NSSW adopted a temperature which they derived from a Zanstra analysis of the He II recombination lines. According to their analysis there should be a continuum jump at 2050 A. New IUE observations of the WN 5 star HD 50896 however did not show any trace of such an absorption edge. This implies that the effective temperature of this WN 5 star and probably of all WR stars with a non blackbody energy distribution is not yet known accurately. Therefore the author started a detailed analysis with a spherically symmetric atmosphere model. Though the model has not yet reached its final shape he has obtained as a first result that the location of HD 50896 in the HR-diagram is to the left of the ZAMS and that the Zanstra analysis is indeed not valid for this star. (Auth.)

  12. Ponderomotive force effects on temperature-gradient-driven instabilities

    International Nuclear Information System (INIS)

    Sundaram, A.K.; Hershkowitz, N.

    1992-01-01

    The modification of temperature-gradient-driven instabilities due to the presence of nonuniform radio-frequency fields near the ion cyclotron frequency is investigated in the linear regime. Employing the fluid theory, it is shown that the induced field line compression caused by ion cyclotron range of frequencies (ICRF) fields makes the net parallel compressibility positive, and thus provides a stabilizing influence on the ion-temperature-gradient-driven mode for an appropriately tailored profile of radio-frequency (rf) pressure. Concomitantly, the radial ponderomotive force generates an additional contribution via coupling between the perturbed fluid motion and the equilibrium ponderomotive force and this effect plays the role of dissipation to enhance or decrease the growth of temperature-gradient-driven modes depending upon the sign of rf pressure gradients. For decreased growth of temperature-gradient-driven instabilities, the plasma density gradients and rf pressure gradients must have opposite signs while enhancement in growth arises when both gradients have the same sign. Finally, the kinetic effects associated with these modes are briefly discussed

  13. Temperature Effect on Micelle Formation: Molecular Thermodynamic Model Revisited.

    Science.gov (United States)

    Khoshnood, Atefeh; Lukanov, Boris; Firoozabadi, Abbas

    2016-03-08

    Temperature affects the aggregation of macromolecules such as surfactants, polymers, and proteins in aqueous solutions. The effect on the critical micelle concentration (CMC) is often nonmonotonic. In this work, the effect of temperature on the micellization of ionic and nonionic surfactants in aqueous solutions is studied using a molecular thermodynamic model. Previous studies based on this technique have predicted monotonic behavior for ionic surfactants. Our investigation shows that the choice of tail transfer energy to describe the hydrophobic effect between the surfactant tails and the polar solvent molecules plays a key role in the predicted CMC. We modify the tail transfer energy by taking into account the effect of the surfactant head on the neighboring methylene group. The modification improves the description of the CMC and the predicted micellar size for aqueous solutions of sodium n-alkyl sulfate, dodecyl trimethylammonium bromide (DTAB), and n-alkyl polyoxyethylene. The new tail transfer energy describes the nonmonotonic behavior of CMC versus temperature. In the DTAB-water system, we redefine the head size by including the methylene group, next to the nitrogen, in the head. The change in the head size along with our modified tail transfer energy improves the CMC and aggregation size prediction significantly. Tail transfer is a dominant energy contribution in micellar and microemulsion systems. It also promotes the adsorption of surfactants at fluid-fluid interfaces and affects the formation of adsorbed layer at fluid-solid interfaces. Our proposed modifications have direct applications in the thermodynamic modeling of the effect of temperature on molecular aggregation, both in the bulk and at the interfaces.

  14. Effect of temperature on the oxidation of soybean biodiesel

    Directory of Open Access Journals (Sweden)

    Pereira, G. G.

    2015-06-01

    Full Text Available This paper proposes to examine the effect of temperature on the oxidation behavior of biodiesel. Soybean biodiesel was oxidized at different temperatures (room temperature, 60, and 110 °C, and the increase in primary and secondary oxidation products was determined based on the peroxide and anisidine values, respectively, during the induction period (IP. The results indicated that the evolution of hydroperoxides followed zero-order reaction kinetics during the IP at all temperatures, and their rate of formation was exponentially affected by temperature. It was also deduced that temperature influenced the ratio between primary and secondary oxidation products formation, which decreased as the temperature increased. Additionally, it was possible to predict the oxidation behavior of the soybean biodiesel at room temperature by an exponential model fitted to the IP values at different temperatures (70, 80, 90, 100, and 110 °C using the Rancimat apparatus.El propósito de este trabajo es evaluar el efecto de la temperatura en el comportamiento oxidativo del biodiesel. Biodiesel derivado de aceite de soja fue oxidado a diferentes temperaturas (temperatura ambiente, 60 y 110 °C y se evaluaron el contenido de compuestos primarios y secundarios de oxidación mediante el índice de peróxidos y de anisidina, respectivamente, a lo largo del periodo de inducción. Los resultados indicaron que el contenido de hidroperóxidos evolucionó siguiendo una cinética de orden cero a lo largo del periodo de inducción a todas las temperaturas y que su velocidad de formación cambió exponencialmente con la temperatura. También se dedujo que la temperatura influyó en la relación entre la formación de los productos de oxidación primarios y secundarios, disminuyendo a medida que aumentaba la temperatura. Además, fue posible predecir el comportamiento oxidativo del biodiesel de soja a temperatura ambiente ajustando a un modelo exponencial los valores de periodo

  15. Low temperature isotope effects of hydrogen diffusion in metallic glasses

    International Nuclear Information System (INIS)

    Hofmann, A.; Kronmueller, H.

    1989-01-01

    Snoek-like relaxation peaks of Hydrogen and Deuterium in amorphous Fe 80 B 20 , Fe 40 Ni 40 P 14 B 6 and Fe 91 Zr 9 are detected. At low H, D concentrations the peaks are near 200 K and show small isotope effects of the average activation energies (anti Q H ≅ 0.6 eV, anti Q D - anti Q H ≤ 10 meV). For higher H, D-contents the peaks shift to lower temperatures around to 120 K and show distinct isotope effects in the activation energies (anti Q H ≅ 0.3 eV, anti Q D - anti Q H ≅ 30 meV) and in the amplitude of the low temperature tails of the relaxation peaks. This points to isotope mass dependent deviations from the Arrhenius law due to nonthermal tunneling processes. (orig.)

  16. Effects of eutrophication and temperature on submersed rooted plants

    DEFF Research Database (Denmark)

    Raun, Ane-Marie Løvendahl

    nutrient levels facilitate the formation of pelagic alga blooms which lead to poor light conditions (Nielsen et al., 2002). However, the lack of re‐colonization after reduced nutrient loading for Zostera marina and other seagrasses indicates that other factors influence the pattern. Sedimentation...... in combination with high temperature affect internal oxygen concentrations, growth and survival of aquatic macrophytes. Measurements of internal oxygen levels were made on several north temperate and tropical marine seagrass species exposed to a range of water column oxygen concentrations. The combined effects...... of eutrophication and temperatures were clarified for the temporal seagrass Zostera marina. Furthermore, the direct effect of sediment enrichment with labile organic matter was examined for four freshwater species with different growth strategies (isoetids: Lobelia dortmanna and Littorella uniflora, and elodeids...

  17. Global non-linear effect of temperature on economic production.

    Science.gov (United States)

    Burke, Marshall; Hsiang, Solomon M; Miguel, Edward

    2015-11-12

    Growing evidence demonstrates that climatic conditions can have a profound impact on the functioning of modern human societies, but effects on economic activity appear inconsistent. Fundamental productive elements of modern economies, such as workers and crops, exhibit highly non-linear responses to local temperature even in wealthy countries. In contrast, aggregate macroeconomic productivity of entire wealthy countries is reported not to respond to temperature, while poor countries respond only linearly. Resolving this conflict between micro and macro observations is critical to understanding the role of wealth in coupled human-natural systems and to anticipating the global impact of climate change. Here we unify these seemingly contradictory results by accounting for non-linearity at the macro scale. We show that overall economic productivity is non-linear in temperature for all countries, with productivity peaking at an annual average temperature of 13 °C and declining strongly at higher temperatures. The relationship is globally generalizable, unchanged since 1960, and apparent for agricultural and non-agricultural activity in both rich and poor countries. These results provide the first evidence that economic activity in all regions is coupled to the global climate and establish a new empirical foundation for modelling economic loss in response to climate change, with important implications. If future adaptation mimics past adaptation, unmitigated warming is expected to reshape the global economy by reducing average global incomes roughly 23% by 2100 and widening global income inequality, relative to scenarios without climate change. In contrast to prior estimates, expected global losses are approximately linear in global mean temperature, with median losses many times larger than leading models indicate.

  18. Global non-linear effect of temperature on economic production

    Science.gov (United States)

    Burke, Marshall; Hsiang, Solomon M.; Miguel, Edward

    2015-11-01

    Growing evidence demonstrates that climatic conditions can have a profound impact on the functioning of modern human societies, but effects on economic activity appear inconsistent. Fundamental productive elements of modern economies, such as workers and crops, exhibit highly non-linear responses to local temperature even in wealthy countries. In contrast, aggregate macroeconomic productivity of entire wealthy countries is reported not to respond to temperature, while poor countries respond only linearly. Resolving this conflict between micro and macro observations is critical to understanding the role of wealth in coupled human-natural systems and to anticipating the global impact of climate change. Here we unify these seemingly contradictory results by accounting for non-linearity at the macro scale. We show that overall economic productivity is non-linear in temperature for all countries, with productivity peaking at an annual average temperature of 13 °C and declining strongly at higher temperatures. The relationship is globally generalizable, unchanged since 1960, and apparent for agricultural and non-agricultural activity in both rich and poor countries. These results provide the first evidence that economic activity in all regions is coupled to the global climate and establish a new empirical foundation for modelling economic loss in response to climate change, with important implications. If future adaptation mimics past adaptation, unmitigated warming is expected to reshape the global economy by reducing average global incomes roughly 23% by 2100 and widening global income inequality, relative to scenarios without climate change. In contrast to prior estimates, expected global losses are approximately linear in global mean temperature, with median losses many times larger than leading models indicate.

  19. Temperature effects on sinking velocity of different Emiliania huxleyi strains.

    Science.gov (United States)

    Rosas-Navarro, Anaid; Langer, Gerald; Ziveri, Patrizia

    2018-01-01

    The sinking properties of three strains of Emiliania huxleyi in response to temperature changes were examined. We used a recently proposed approach to calculate sinking velocities from coccosphere architecture, which has the advantage to be applicable not only to culture samples, but also to field samples including fossil material. Our data show that temperature in the sub-optimal range impacts sinking velocity of E. huxleyi. This response is widespread among strains isolated in different locations and moreover comparatively predictable, as indicated by the similar slopes of the linear regressions. Sinking velocity was positively correlated to temperature as well as individual cell PIC/POC over the sub-optimum to optimum temperature range in all strains. In the context of climate change our data point to an important influence of global warming on sinking velocities. It has recently been shown that seawater acidification has no effect on sinking velocity of a Mediterranean E. huxleyi strain, while nutrient limitation seems to have a small negative effect on sinking velocity. Given that warming, acidification, and lowered nutrient availability will occur simultaneously under climate change scenarios, the question is what the net effect of different influential factors will be. For example, will the effects of warming and nutrient limitation cancel? This question cannot be answered conclusively but analyses of field samples in addition to laboratory culture studies will improve predictions because in field samples multi-factor influences and even evolutionary changes are not excluded. As mentioned above, the approach of determining sinking rate followed here is applicable to field samples. Future studies could use it to analyse not only seasonal and geographic patterns but also changes in sinking velocity over geological time scales.

  20. Effect of pairing in nuclear level density at low temperatures

    International Nuclear Information System (INIS)

    Rhine Kumar, A.K.; Modi, Swati; Arumugam, P.

    2013-01-01

    The nuclear level density (NLD) has been an interesting topic for researchers, due its importance in many aspects of nuclear physics, nuclear astrophysics, nuclear medicine, and other applied areas. The calculation of NLD helps us to understand the energy distribution of the excited levels of nuclei, entropy, specific heat, reaction cross sections etc. In this work the effect of temperature and pairing on level-density of the nucleus 116 Sn has been studied

  1. Cosmic-ray test and temperature effects of MRPC

    International Nuclear Information System (INIS)

    Yue Qian; Li Yuanjing; Cheng Jianping; Wang Yi; Li Jin; Lai Yongfang; Li Qinghua; Tang Le

    2004-01-01

    A comic-ray test system has been built for testing the performance of MRPC modules. Some methods have been studied to improve the time resolution of the cosmic-ray test based on this testing system. The time resolutions of about 84 ps and 75 ps can be achieved for MRPC and its reference time, respectively. The temperature effects of MRPC have also been researched and some useful results are obtained. (author)

  2. The effective neutron temperature in heated graphite sleeves

    Energy Technology Data Exchange (ETDEWEB)

    Shaw, J A; Small, V G [General Reactor Physics Division, Atomic Energy Establishment, Winfrith, Dorchester, Dorset (United Kingdom)

    1963-08-15

    In a series of oscillator measurements carried out in the reactor NERO the variation of the relative reaction rates of cadmium and boron absorbers has been used to determine the effective neutron temperature inside heated graphite sleeves. This work extends the scope of similar oscillator measurements previously carried out in DIMPLE, in that the bulk moderator is now graphite as opposed to D{sub 2}O in the former case. (author)

  3. Effect of extraction temperature on characteristics of chicken legskin gelatin

    Science.gov (United States)

    Sompie, M.; Triasih, A.

    2018-01-01

    Gelatin is a denaturalized protein that is derived from collagen by acidic or alkaline hydrolysis and is an important functional biopolymer that has a very broad application in many industrial fields. Its functional properties depend on processing conditions as well as the raw material. The objective of the research was to study effect of extraction temperature on characteristics of native chicken legskin gelatin. This study used Completely Randomized Design (CRD) with four treatments (T1 = 500C, T2 = 550C, T3 = 600C, T4 = 650C) and five replications. Statistical analysis were carried out by one Anova and the mean difference was tested using Duncan’s Multiple Range Test. The result of research indicated that, extraction temperature had significant effect (Pchicken legskin gelatin, but it had no significant effect (P>0.05) on water content. It was concluded that the use of extraction temperature 600C was (yields 13.75, gel strength 78.75 g bloom, viscosity 6.52 cP, protein content 84.23% and water content 6.20%).

  4. Effects of Temperature on Polymer/Carbon Chemical Sensors

    Science.gov (United States)

    Manfireda, Allison; Lara, Liana; Homer, Margie; Yen, Shiao-Pin; Kisor, Adam; Ryan, Margaret; Zhou, Hanying; Shevade, Abhijit; James, Lim; Manatt, Kenneth

    2009-01-01

    Experiments were conducted on the effects of temperature, polymer molecular weight, and carbon loading on the electrical resistances of polymer/carbon-black composite films. The experiment were performed in a continuing effort to develop such films as part of the JPL Electronic Nose (ENose), that would be used to detect, identify, and quantify parts-per-million (ppm) concentration levels of airborne chemicals in the space shuttle/space station environments. The polymers used in this study were three formulations of poly(ethylene oxide) [PEO] that had molecular weights of 20 kilodaltons, 600 kilodaltons, and 1 megadalton, respectively. The results of one set of experiments showed a correlation between the polymer molecular weight and the percolation threshold. In a second set of experiments, differences among the temperature dependences of resistance were observed for different carbon loadings; these differences could be explained by a change in the conduction mechanism. In a third set of experiments, the responses of six different polymer/carbon composite sensors to three analytes (water vapor, methanol, methane) were measured as a function of temperature (28 to 36 C). For a given concentration of each analyte, the response of each sensor decreased with increasing temperature, in a manner different from those of the other sensors.

  5. Temperature Effects on Cuscuta campestris Yunk. Seed Germination

    Directory of Open Access Journals (Sweden)

    Marija Sarić-Krsmanović

    2013-01-01

    Full Text Available Studies of biological characteristics of seeds and conditions for their germination havea major importance for planning and executing rational measures of weed control. Theaim of this study was to investigate the effect of different temperatures on germinationof C. campestris seeds. Three treatments (T1- storage at room temperature; T2 – exposureto 4°C for 30 days; T3 – scarification by concentrated sulphuric acid differing in manipulationwith seeds before germination were tested at different temperatures (5°C, 10°C, 15°C,20°C, 25°C, 30°C, 35°C, 40°C, 45°C. Germinated seeds were counted daily for ten days andthe length of seedlings was measured on the last day. The results showed that differencesin germination of C. campestris seeds were very prominent between temperatures, as wellas between treatments T1, T2 and T3. Seeds failed to germinate at 5°C and 45°C in all treatments(T1, T2, T3. Germination ranged from 6.25 at 10°C to 96.88%, the highest percentage,achieved at 30°C.

  6. Effects of Elevated Temperature on Concrete with Recycled Coarse Aggregates

    Science.gov (United States)

    Salau, M. A.; Oseafiana, O. J.; Oyegoke, T. O.

    2015-11-01

    This paper discusses the effects of heating temperatures of 200°C, 400°C and 600°C each for 2 hours at a heating rate of 2.5°C/min on concrete with the content of Natural Coarse Aggregates (NCA) partially replaced with Recycled Coarse Aggregates (RCA), obtained from demolished building in the ratio of 0%, 15% and 30%.There was an initial drop in strength from 100°C to 200°C which is suspected to be due to the relatively weak interfacial bond between the RCA and the hardened paste within the concrete matrix;a gradual increase in strength continued from 200°C to 450°C and steady drop occurred again as it approached 600°C.With replacement proportion of 0%, 15% and 30% of NCA and exposure to peak temperature of 600°C, a relative concrete strength of 23.6MPa, 25.3MPa and 22.2MPa respectively can be achieved for 28 days curing age. Furthermore, RAC with 15% NCA replacement when exposed to optimum temperature of 450°C yielded high compressive strength comparable to that of control specimen (normal concrete). In addition, for all concrete samples only slight surface hairline cracks were noticed as the temperature approached 400°C. Thus, the RAC demonstrated behavior just like normal concrete and may be considered fit for structural use.

  7. Modeling of helium effects in metals: High temperature embrittlement

    International Nuclear Information System (INIS)

    Trinkaus, H.

    1985-01-01

    The effects of helium on swelling, creep rupture and fatigue properties of fusion reactor materials subjected to (n,α)-reactions and/or direct α-injection, are controlled by bubble formation. The understanding of such effects requires therefore the modeling of (1) diffusional reactions of He atoms with other defects; (2) nucleation and growth of He bubbles; (3) transformation of such bubbles into cavities under continuous He generation and irradiation or creep stress. The present paper is focussed on the modeling of the (coupled) high temperature bubble nucleation and growth processes within and on grain boundaries. Two limiting cases are considered: di-atomic nucleation described by the simplest possible sets of rate equations, and multi-atomic nucleation described by classical nucleation theory. Scaling laws are derived which characterize the dependence of the bubble densities upon time (He-dose), He generation rate and temperature. Comparison with experimental data of AISI 316 SS α-implanted at temperatures around 1000 K indicates bubble nucleation of the multi-atomic type. The nucleation and growth models are applied to creep tests performed during α-implantation suggesting that in these cases gas driven bubble growth is the life time controlling mechanism. The narrow (creep stress/He generation rate) range of this mechanism in a mechanism map constructed from these tests indicates that in many reactor situations the time to rupture is probably controlled by stress driven cavity growth rather than by gas driven bubble growth. (orig.)

  8. Temperature effect on the behaviour of engineered clay barriers

    International Nuclear Information System (INIS)

    Tang, A.M.

    2005-11-01

    The present work deals with the thermo-hydro-mechanical behaviour of compacted swelling clay used for engineered barriers in high-level radioactive repositories. The MX80 bentonite was chosen for this work. Firstly, an experimental work on the thermal conductivity of the compacted bentonite was performed. The results evidenced the effects of dry density, water content, volumetric fraction of soil components, microstructure, and mineralogy. This experimental work gave rise to the proposition of a theoretical model for estimate the thermal conductivity of compacted bentonites. Secondly, after a calibration of suction generated by saturated saline solution in function of temperature, water retention curves were determined at different temperatures. The experimental results showed a decrease of the water retention capacity of soil after heating. A simple model based on the interfacial tension air-water was formulated to simulate this effect. Thirdly, a new isotropic cell enabling a simultaneous control of suction, temperature and mechanical stress was developed. With this new cell, an experimental work on the thermo-mechanical behaviour of the unsaturated compacted bentonite was performed. Finally, a constitutive model was developed for simulate the thermo-hydro-mechanical behaviours obtained experimentally. (author)

  9. Rheology of Indian Honey: Effect of Temperature and Gamma Radiation

    Directory of Open Access Journals (Sweden)

    Sudhanshu Saxena

    2014-01-01

    Full Text Available Honey brands commonly available in Indian market were characterized for their rheological and thermal properties. Viscosity of all the honey samples belonging to different commercial brands was found to decrease with increase in temperature (5–40°C and their sensitivity towards temperature varied significantly as explained by calculating activation energy based on Arrhenius model and ranged from 54.0 to 89.0 kJ/mol. However, shear rate was not found to alter the viscosity of honey indicating their Newtonian character and the shear stress varied linearly with shear rate for all honey samples. Honey is known to contain pathogenic microbial spores and in our earlier study gamma radiation was found to be effective in achieving microbial decontamination of honey. The effect of gamma radiation (5–15 kGy on rheological properties of honey was assessed, and it was found to remain unchanged upon radiation treatment. The glass transition temperatures (Tg of these honey analyzed by differential scanning calorimetry varied from −44.1 to −54.1°C and remained unchanged upon gamma radiation treatment. The results provide information about some key physical properties of commercial Indian honey. Radiation treatment which is useful for ensuring microbial safety of honey does not alter these properties.

  10. (Amino acid + silica) adsorption thermodynamics: Effects of temperature

    International Nuclear Information System (INIS)

    Sebben, Damien; Pendleton, Phillip

    2015-01-01

    Highlights: • High resolution, low concentration Gly, Lys and Glu solution adsorption isotherms. • All isotherms fitted with Langmuir–Freundlich isotherm model. • Gly, Lys and Glu show exothermic adsorption processes. • Isosteric heat analyses reveal changes in interaction strength with surface coverage. - Abstract: A thorough understanding of amino acid adsorption by mineral and oxide surfaces has a major impact on a variety of industrial and biomedical applications. Little information currently exists regarding temperature effects on most of these adsorption processes. Deeper thermodynamic analyses of their multiple temperature adsorption isotherms would aid the interpretation of the interfacial interactions. Low solution concentration adsorption isotherms for glycine, lysine and glutamic acid on a silica adsorbent were generated for T = (291, 298 and 310) K. Data analysis via the Clausius–Clapeyron method yielded the isosteric heat of adsorption as a function of fractional monolayer coverage for each adsorptive. Each amino acid showed an exothermic adsorption response. Glycine and lysine experienced a greater negative effect of increased temperature compared with glutamic acid, indicating a greater number of adsorbed molecules than glutamic acid, with the former undergoing intermolecular clustering within the adsorbed phase. Isosteric heat analyses suggest ionic interactions for lysine and hydrogen bonding for glutamic acid, both weakening with increased coverage. In contrast, initial hydrogen bonding led to ionic bonding for glycine with increasing coverage

  11. The Effects of Air Pollution and Temperature on COPD.

    Science.gov (United States)

    Hansel, Nadia N; McCormack, Meredith C; Kim, Victor

    2016-06-01

    Chronic Obstructive Pulmonary Disease (COPD) affects 12-16 million people in the United States and is the third-leading cause of death. In developed countries, smoking is the greatest risk factor for the development of COPD, but other exposures also contribute to the development and progression of the disease. Several studies suggest, though are not definitive, that outdoor air pollution exposure is linked to the prevalence and incidence of COPD. Among individuals with COPD, outdoor air pollutants are associated with loss of lung function and increased respiratory symptoms. In addition, outdoor air pollutants are also associated with COPD exacerbations and mortality. There is much less evidence for the impact of indoor air on COPD, especially in developed countries in residences without biomass exposure. The limited existing data suggests that indoor particulate matter and nitrogen dioxide concentrations are linked to increased respiratory symptoms among patients with COPD. In addition, with the projected increases in temperature and extreme weather events in the context of climate change there has been increased attention to the effects of heat exposure. Extremes of temperature-both heat and cold-have been associated with increased respiratory morbidity in COPD. Some studies also suggest that temperature may modify the effect of pollution exposure and though results are not conclusive, understanding factors that may modify susceptibility to air pollution in patients with COPD is of utmost importance.

  12. Effect of dialysate temperature on hemodynamic stability among hemodialysis patients

    International Nuclear Information System (INIS)

    Azar, Ahmad Taher

    2009-01-01

    Cooling the dialysate below 36.5 degree C is an important factor that contributes to hemody-namic stability in patients during hemodialysis (HD). In this study, the effect of dialysate tempe-rature on hemodynamic stability, patients' perception of dialysis discomfort and post dialysis fatigue were assessed in a group of patients on HD. A total of 50 patients, all of whom were on 3-times-perweek dialysis regimen, were studied. Patients were assessed during six dialysis sessions; in three sessions, the dialysate temperature was normal (37 degree C) and in three other sessions, the dialysate temperature was low (35 degree C). Specific scale questionnaires were used in each dialysis session, to evaluate the symptoms during the dialysis procedure as well as post-dialysis fatigue, and respective scores were noted. The results showed that usage of low dialysate temperature was associated with the following: higher post dialysis systolic blood pressure (P< 0.05) and lower post dialysis heart rate (P<0.01), with similar ultrafiltration rates, better intra-dialysis symptoms score and post-dialysis fatigue scores (P< 0.001, and P<0.001, respectively), shorter post-dialysis fatigue period (P<0.001) as well as higher urea removal (P< 00001) and Kt/V (P< 0.0001). Patients' perceptions were measured by a questionnaire, which showed that 76% of them felt more energetic after dialysis with cool dialysate and requested to be always dialyzed with cool dialysate. Low temperature dialysate is particularly beneficial for highly symptomatic patients, improves tolerance to dialysis in hypotensive patients and helps increase ultrafiltration while maintaining hemodynamic stability during and after dialysis. (author)

  13. Effect of storage temperature on the activity of submitochondrial particles.

    Science.gov (United States)

    Doherty, Francis G

    2008-12-01

    The submitochondrial particle (SMP) assay employs processed mammalian mitchondria to assess the toxicity of chemical contaminants in aqueous solutions. Particles and associated reagents are commercially available to support two individual procedures, the electron transfer (ETr) and reverse electron transfer (RET) assays. The objective of the present study was to assess the effect of storage temperature on SMP activity. One RET and one ETr assay were conducted with sodium dodecylsulfate on each of two vials of particles stored at -20 and -80 degrees C at periodic intervals over a six-month span. Results demonstrated that SMP could remain active in either assay through six months of storage at either temperature. However, there were isolated vials of particles stored at -20 degrees C that exhibited unacceptable reductions in activity for both the ETr and the RET assays that were not related to storage duration. These results were used to develop guidance in assessing the acceptability of particle activity in SMP assays.

  14. Effects of electrons on the solar wind proton temperature anisotropy

    International Nuclear Information System (INIS)

    Michno, M. J.; Lazar, M.; Schlickeiser, R.; Yoon, P. H.

    2014-01-01

    Among the kinetic microinstabilities, the firehose instability is one of the most efficient mechanisms to restrict the unlimited increase of temperature anisotropy in the direction of an ambient magnetic field as predicted by adiabatic expansion of collision-poor solar wind. Indeed, the solar wind proton temperature anisotropy detected near 1 AU shows that it is constrained by the marginal firehose condition. Of the two types of firehose instabilities, namely, parallel and oblique, the literature suggests that the solar wind data conform more closely to the marginal oblique firehose condition. In the present work, however, it is shown that the parallel firehose instability threshold is markedly influenced by the presence of anisotropic electrons, such that under some circumstances, the cumulative effects of both electron and proton anisotropies could describe the observation without considering the oblique firehose mode.

  15. Effect of re-heating on the hot electron temperature

    International Nuclear Information System (INIS)

    Estabrook, K.; Rosen, M.

    1980-01-01

    Resonant absorption is the direct conversion of the transverse laser light to longitudinal electron plasma waves (epw) at the critical density [10 21 (1.06 μm/lambda 0 ) 2 cm -3 ]. The oscillating longitudinal electric field of the epw heats the electrons by accelerating them down the density gradient to a temperature of approximately 21T/sub e/ 0 25 ([I(W/cm 2 )/10 16 ](lambda 0 /1.06 μm) 2 ) 0 4 . This section extends the previous work by studying the effects of magnetic fields and collisions (albedo) which return the heated electrons for further heating. A magnetic field increases their temperature and collisions do not

  16. Pressure and temperature effects in homopolymer blends and diblock copolymers

    DEFF Research Database (Denmark)

    Frielinghaus, H.; Schwahn, D.; Mortensen, K.

    1997-01-01

    Thermal composition fluctuations in a homogeneous binary polymer blend and in a diblock copolymer were measured by small-angle neutron scattering as a function of temperature and pressure. The experimental data were analyzed with theoretical expressions, including the important effect of thermal...... fluctuations. Phase boundaries, the Flory-Huggins interaction parameter and the Ginzburg number were obtained. The packing of the molecules changes with pressure. Therefore, the degree of thermal fluctuation as a function of packing and temperature was studied. While in polymer blends packing leads, in some...... respects, to a universal behaviour, such behaviour is not found in diblock copolymers. It is shown that the Ginzburg number decreases with pressure sensitively in blends, while it is constant in diblock copolymers. The Ginzburg number is an estimation of the transition between the universality classes...

  17. Variable temperature effects on release rates of readily soluble nuclides

    International Nuclear Information System (INIS)

    Kim, C.-L.; Light, W.B.; Lee, W.W.-L.; Chambre, P.L.; Pigford, T.H.

    1988-09-01

    In this paper we study the effect of temperature on the release rate of readily soluble nuclides, as affected by a time-temperature dependent diffusion coefficient. In this analysis ground water fills the voids in the waste package at t = 0 and one percent of the inventories of cesium and iodine are immediately dissolved into the void water. Mass transfer resistance of partly failed container and cladding is conservatively neglected. The nuclides move through the void space into the surrounding rock under a concentration gradient. We use an analytic solution to compute the nuclide concentration in the gap or void, and the mass flux rate into the porous rock. 8 refs., 4 figs

  18. Temperature Effects on Aluminoborosilicate Glass and Melt Structure

    Science.gov (United States)

    Wu, J.; Stebbins, J. F.

    2008-12-01

    Quantitative determination of the atomic-scale structure of multi-component oxide melts, and the effects of temperature on them, is a complex problem. Ca- and Na- aluminoborosilicates are especially interesting, not only because of their major role in widespread technical applications (flat-panel computer displays, fiber composites, etc.), but because the coordination environments of two of their main network cations (Al3+ and B3+) change markedly with composition and temperature is ways that may in part be analogous to processes in silicate melts at high pressures in the Earth. Here we examine a series of such glasses with different cooling rates, chosen to evaluate the role modifier cation field strength (Ca2+ vs. Na+) and of non-bridging oxygen (NBO) content. To explore the effects of fictive temperature, fast quenched and annealed samples were compared. We have used B-11 and Al-27 MAS NMR to measure the different B and Al coordinations and calculated the contents of non-bridging oxygens (NBO). Lower cooling rates increase the fraction of [4]B species in all compositions. The conversion of [3]B to [4]B is also expected to convert NBO to bridging oxygens, which should affect thermodynamic properties such as configurational entropy and configurational heat capacity. For four compositions with widely varying compositions and initial NBO contents, analysis of the speciation changes with the same, simple reaction [3]B = [4]B + NBO yields similar enthalpy values of 25±7 kJ/mol. B-11 triple quantum MAS NMR allows as well the proportions of [3]B boroxol ring and non-ring sites to be determined, and reveals more [3]B boroxol ring structures present in annealed (lower temperature) glasses. In situ, high-temperature MAS NMR spectra have been collected on one of the Na-aluminoborosilicate and on a sodium borate glass at 14.1 T. The exchange of boron between the 3- and 4-coordinated sites is clearly observed well above the glass transition temperatures, confirming the

  19. The Effects of the Heat and Moisture Exchanger on Humidity, Airway Temperature, and Core Body Temperature

    National Research Council Canada - National Science Library

    Delventhal, Mary

    1999-01-01

    Findings from several studies have demonstrated that the use of a heat and moisture exchanger increases airway humidity, which in turn increases mean airway temperature and prevents decreases in core body temperature...

  20. Effect and control on temperature measurement accuracy of the fiber- optic colorimeter by emissivity of different temperatures

    Science.gov (United States)

    Liu, Yu-fang; Han, Xin; Shi, De-heng

    2008-03-01

    Based on the Kirchhoff's Law, a practical dual-wavelength fiber-optic colorimeter, with the optimal work wavelength centered at 2.1 μm and 2.3 μm is presented. The effect of the emissivity on the precision of the measured temperature has been explored under various circumstances (i.e. temperature, wavelength) and for different materials. In addition, by fitting several typical material emissivity-temperature dependencies curves, the influence of the irradiation (radiant flux originating from the surroundings) and the surface reflected radiation on the temperature accuracy is studied. The results show that the calibration of the measured temperature for reflected radiant energy is necessary especially in low target temperature or low target emissivity, and the temperature accuracy is suitable for requirements in the range of 400-1200K.

  1. Solute strengthening effects for 316 stainless steel at elevated temperature

    International Nuclear Information System (INIS)

    Park, Nam Ju; Lee, Sang Mae

    1986-01-01

    The inelastic behavior of 316 stainless steel is studied in order to investigate the solute strengthening effects. The Arrhenius-type rate equation with inclusion of the Voce-type evolution phenomenon is extended by addition of solute strengthening term to the isotropic work hardening effect. Changing of strain rate and temperature during the tension tests, we found that the strong work hardening for the inelastic of 316 stainless steel resulted from the vacancy-interstitial pair mechanism. Thus, the calculated results using the extended constitutive equations including solute effect due to the vacancy-interstitial pair mechanism were found to be in good agreement with the stress-strain curves obtained from the tension tests. (Author)

  2. Nonlinear effects of high temperature on buckling of structural elements

    International Nuclear Information System (INIS)

    Iyengar, N.G.R.

    1975-01-01

    Structural elements used in nuclear reactors are subjected to high temperatures. Since with increase in temperature there is a gradual fall in the elastic modulus and the stress-strain relationship is nonlinear at these operating load levels, a realistic estimate of the buckling load should include this nonlinearity. In this paper the buckling loads for uniform columns with circular and rectangular cross-sections and different boundary conditions under high temperature environment are estimated. The stress-strain relationship for the material has been assumed to follow inverse Ramberg-Osgood law. In view of the fact that no closed form solutions are possible, approximate methods like perturbation and Galerkin techniques are used. Further, the solution for general value for 'm' is quite involved. Results have been obtained with values for 'm' as 3 and 5. Studies reveal that the influence of material nonlinearity on the buckling load is of the softening type, and it increases with increase in the value of 'm'. The nonlinear effects are more for clamped boundaries than for simply supported boundaries. For the first mode analysis both the methods are powerful. It is, however, felt that for higher modes the Galerkin method might be better in view of its simplicity. This investigation may be considered as a step towards a more general solution

  3. Temperature effects on MIPs in the BGO calorimeters of DAMPE

    Science.gov (United States)

    Wang, Yuan-Peng; Wen, Si-Cheng; Jiang, Wei; Yue, Chuan; Zhang, Zhi-Yong; Wei, Yi-Feng; Zhang, YunLong; Zang, Jing-Jing; Wu, Jian

    2017-10-01

    In this paper, we present a study of temperature effects on BGO calorimeters using proton MIPs collected in the first year of operation of DAMPE. By directly comparing MIP calibration constants used by the DAMPE data production pipe line, we find an experimental relation between the temperature and signal amplitudes of each BGO bar: a general deviation of -1.162%/°C, and -0.47%/°C to -1.60%/°C statistically for each detector element. During 2016, DAMPE’s temperature changed by ˜8°C due to solar elevation angle, and the corresponding energy scale bias is about 9%. By frequent MIP calibration operation, this kind of bias is eliminated to an acceptable value. This work was supported by National Key Program for Research and Development (No. 2016YFA0400200) and by NSFC (11303105, 11673021). The DAMPE mission was funded by the strategic priority science and technology projects in space science of the Chinese Academy of Sciences (No. XDA04040000 and No. XDA04040400)

  4. Interplay between geometry and temperature in the Casimir effect

    Energy Technology Data Exchange (ETDEWEB)

    Weber, Alexej

    2010-06-23

    In this thesis, we investigate the interplay between geometry and temperature in the Casimir effect for the inclined-plates, sphere-plate and cylinder-plate configurations. We use the worldline approach, which combines the string-inspired quantum field theoretical formalism with Monte Carlo techniques. The approach allows the precise computation of Casimir energies in arbitrary geometries. We analyze the dependence of the Casimir energy, force and torque on the separation parameter and temperature T, and find Casimir phenomena which are dominated by long-range fluctuations. We demonstrate that for open geometries, thermal energy densities are typically distributed on scales of thermal wavelengths. As an important consequence, approximation methods for thermal corrections based on local energy-density estimates, such as the proximity-force approximation, are found to become unreliable even at small surface-separations. Whereas the hightemperature behavior is always found to be linear in T, richer power-law behaviors at small temperatures emerge. In particular, thermal forces can develop a non-monotonic behavior. Many novel numerical as well as analytical results are presented. (orig.)

  5. Interplay between geometry and temperature in the Casimir effect

    International Nuclear Information System (INIS)

    Weber, Alexej

    2010-01-01

    In this thesis, we investigate the interplay between geometry and temperature in the Casimir effect for the inclined-plates, sphere-plate and cylinder-plate configurations. We use the worldline approach, which combines the string-inspired quantum field theoretical formalism with Monte Carlo techniques. The approach allows the precise computation of Casimir energies in arbitrary geometries. We analyze the dependence of the Casimir energy, force and torque on the separation parameter and temperature T, and find Casimir phenomena which are dominated by long-range fluctuations. We demonstrate that for open geometries, thermal energy densities are typically distributed on scales of thermal wavelengths. As an important consequence, approximation methods for thermal corrections based on local energy-density estimates, such as the proximity-force approximation, are found to become unreliable even at small surface-separations. Whereas the hightemperature behavior is always found to be linear in T, richer power-law behaviors at small temperatures emerge. In particular, thermal forces can develop a non-monotonic behavior. Many novel numerical as well as analytical results are presented. (orig.)

  6. The effects of fire temperatures on water soluble heavy metals.

    Science.gov (United States)

    Pereira, P.; Ubeda, X.; Martin, D. A.

    2009-04-01

    Fire ash are majority composed by base cations, however the mineralized organic matter, led also available to transport a higher quantity of heavy metals that potentially could increase a toxicity in soil and water resources. The amount availability of these elements depend on the environment were the fire took place, burning temperature and combusted tree specie. The soil and water contamination from fire ash has been neglected, because the majority of studies are focused on base cations dynamic. Our research, beside contemplate major elements, is focused in to study the behavior of heavy metals released from ash slurries created at several temperatures under laboratory environment, prescribed fires and wildland fires. The results presented in these communication are preliminary and study the presence of Aluminium (Al3+), Manganese (Mn2+), Iron (Fe2+) and Zinc (Zn2+) of ash slurries generated in laboratory environment at several temperatures (150°, 200°, 250°, 300°, 350°, 400°,450°, 500°, 550°C) from Quercus suber, Quercus robur, Pinus pinea and Pinus pinaster and from a low medium temperature prescribed fire in a forest dominated Quercus suber trees. We observed that ash produced at lower and medium temperatures (Pinus ashes. Fe2+ and Zn2+ showed a reduced concentration in test solution in relation to unburned sample at all temperatures of exposition. In the results obtained from prescribed fire, we identify a higher release of Al3+ and a decrease of the remain elements. The solubilization of these elements are related with pH levels and ash calcite content, because their ability to capture ions in solution. Moreover, the amount and the type of ions released in relation to unburned sample vary in each specie. In this study Al3+ release is related with Quercus species and Mn2+ with Pinus species. Fire ashes can be an environmental problem, because at long term can increase soil acidity. After all base cations have being leached, pH values decrease, and

  7. Effect of Centrifuge Temperature on Routine Coagulation Tests.

    Science.gov (United States)

    Yazar, Hayrullah; Özdemir, Fatma; Köse, Elif

    2018-01-01

    This study investigated the effects of cooled and standard centrifuges on the results of coagulation tests to examine the effects of centrifugation temperature. Equal-volume blood samples from each patient were collected at the same time intervals and subjected to standard (25°C) and cooled centrifugation (2-4°C). Subsequently, the prothrombin time (PT), international normalized ratio (INR), activated partial thromboplastin time (aPTT), fibrinogen, and D-dimer values were determined in runs with the same lot numbers in the same coagulation device using the Dia-PT R (PT and INR), Dia-PTT-liquid (aPTT), Dia-FIB (fibrinogen), and Dia-D-dimer kits, respectively. The study enrolled 771 participants. The PT was significantly (p centrifuges were as follows: PT 10.30 versus 10.50 s; PT (INR) 1.04 versus 1.09 s; APTT 28.90 versus 29.40 s; fibrinogen 321.5 versus 322.1 mg/dL; and D-dimer 179.5 versus 168.7 µg FEU/mL. There were significant differences (p centrifuges. Centrifuge temperature can have a significant effect on the results of coagulation tests. However, broad and specific disease-based studies are needed. © 2018 S. Karger AG, Basel.

  8. Effect of temperature on aflatoxin production in Mucuna pruriens seeds.

    Science.gov (United States)

    Roy, A K; Chourasia, H K

    1989-01-01

    This paper describes the effect of temperature on the level of aflatoxin production in Mucuna pruriens seeds. The highest level of aflatoxin B1 (1.75 micrograms/g) was detected in the samples incubated at 25 degrees C for three weeks. At 20, 30, and 35 degrees C, aflatoxin levels were 0.30 to 0.56, 0.37 to 1.20, and 0.26 to 0.65 micrograms/g, respectively. The lowest concentration of aflatoxin B1 (0.10 to 0.29 microgram/g) was produced at 15 degrees C. PMID:2719482

  9. The Effect of Temperature on the Production of Nitrobenzene

    Science.gov (United States)

    Agustriyanto, R.; Sapei, L.; Rosaline, G.; Setiawan, R.

    2017-02-01

    Nitrobenzene is a compound derived from benzene and quite fundamental in the petrochemical industry. One of which is in the manufacture of aniline. Aniline has an important role as dyes, synthetic rubber materials, rocket fuels and pharmaceuticals. Nitrobenzene can be synthesized by the nitration reaction of benzene. The purpose of the research is to design synthesis process of nitrobenzene by using Aspen Hysys simulator. The effect of changes in operating condition on nitrobenzene will be investigated. The benefits of the research are to obtain the optimum operating temperature for nitrobenzene production so that the use of utility can be minimized.

  10. The Effects of High Temperature on Gessoes with Different Admixtures

    Science.gov (United States)

    Budu, Ana-Maria; Sandu, Ion; Cristache, Raluca Anamaria

    2014-11-01

    This paper presents the effects of temperature on gessoes that have different substances added, usually used in painting or restoration to enhance the flexibility of the ground layer or to create a suitable gesso for the specific painting technique. Five samples of gesso were made and applied on Balsa wood (a dry, stable wood that is used in restoration for completing the missing elements of the panel). After the thermal treatment, the samples were analyzed optical, by microscopy and colorimetry. The results showed small differences in colour, but no cracks of the gessoes

  11. Effects of temperature and salinity on light scattering by water

    Science.gov (United States)

    Zhang, Xiaodong; Hu, Lianbo

    2010-04-01

    A theoretical model on light scattering by water was developed from the thermodynamic principles and was used to evaluate the effects of temperature and salinity. The results agreed with the measurements by Morel within 1%. The scattering increases with salinity in a non-linear manner and the empirical linear model underestimate the scattering by seawater for S < 40 psu. Seawater also exhibits an 'anomalous' scattering behavior with a minimum occurring at 24.64 °C for pure water and this minimum increases with the salinity, reaching 27.49 °C at 40 psu.

  12. Effects of the safety factor on ion temperature gradient modes

    International Nuclear Information System (INIS)

    Wang, A.K.; Dong, J.Q.; Sanuki, H.; Itoh, K.

    2003-01-01

    A model for the ion temperature gradient (ITG) driven instability is derived from Braginskii magnetohydrodynamic equations of ions. The safety factor q in a toroidal plasma is introduced into the model through the current density J parallel . The effects of q or J parallel on both the ITG instability in k perpendicular and k parallel spectra and the critical stability thresholds are studied. It is shown that the current density // J or the safety factor q plays an important role in stabilizing the ITG instability. (author)

  13. Fluctuations in macroscopically agitated plasma:quasiparticles and effective temperature

    International Nuclear Information System (INIS)

    Sosenko, P.P.; Gresillon, D.

    1994-01-01

    Fluctuations in the plasma, in which macroscopic fluid-like motion is agitated due to large-scale and low-frequency electro-magnetic fields, are studied. Such fields can be produced by external factors or internally, for example due to turbulence. Fluctuation spectral distributions are calculated with regard to the renormalization of the transition probability for a test-particle and of the test-particle shielding. If the correlation length for the random fluid-like motion is large as compared to the fluctuation scale lengths, then the fluctuation spectral distributions can be explained in terms of quasiparticles originating from macroscopic plasma agitation and of an effective temperature

  14. High temperature hall effect measurement system design, measurement and analysis

    Science.gov (United States)

    Berkun, Isil

    A reliable knowledge of the transport properties of semiconductor materials is essential for the development and understanding of a number of electronic devices. In this thesis, the work on developing a Hall Effect measurement system with software based data acqui- sition and control for a temperature range of 300K-700K will be described. A system was developed for high temperature measurements of materials including single crystal diamond, poly-crystalline diamond, and thermoelectric compounds. An added capability for monitor- ing the current versus voltage behavior of the contacts was used for studying the influence of ohmic and non-ohmic contacts on Hall Effect measurements. The system has been primar- ily used for testing the transport properties of boron-doped single crystal diamond (SCD) deposited in a microwave plasma-assisted chemical vapor deposition (MPCVD) reactor [1]. Diamond has several outstanding properties that are of high interest for its development as an electronic material. These include a relatively wide band gap of 5.5 (eV), high thermal conductivity, high mobility, high saturation velocity, and a high breakdown voltage. For a temperature range of 300K-700K, IV curves, Hall mobilities and carrier concentrations are shown. Temperature dependent Hall effect measurements have shown carrier concentrations from below 1017cm --3 to approximately 1021 cm--3 with mobilities ranging from 763( cm2/V s) to 0.15(cm 2/V s) respectively. Simulation results have shown the effects of single and mixed carrier models, activation energies, effective mass and doping concentrations. These studies have been helpful in the development of single crystal diamond for diode applications. Reference materials of Ge and GaAs were used to test the Hall Effect system. The system was also used to characterize polycrystalline diamond deposited on glass for electrochemical applications, and Mg2(Si,Sn) compounds which are promising candidates of low-cost, light weight and non

  15. Effects of conductive fillers on temperature distribution of asphalt pavements

    International Nuclear Information System (INIS)

    Chen Mingyu; Wu Shaopeng; Zhang Yuan; Wang Hong

    2010-01-01

    The sun provides a cheap and abundant source of clean and renewable energy. Solar cells have been used to capture this energy and generate electricity. A more useful form of the solar cell would be asphalt pavements, which get heated up by solar radiation. Graphite powders are utilized as thermal conductive fillers to make an asphalt collector conductive so as to improve the efficiency of the asphalt collector. Accounting for the important application conditions and evaluating the effects of the heat conductive materials and the solar energy absorbability of the conductive asphalt collector, a finite element model has been developed to predict temperature distributions in the conductive asphalt solar collector. In this study, an experimental validation exercise was conducted using the measured data taken from full-depth asphalt slabs. Validation results showed that the model can satisfactorily predict the temperature distributions in asphalt concrete slabs. The optimal depth is 25-50 mm for placing pipes that serve as the heat exchanger. Meanwhile, the effect of the surroundings on the solar energy potential of the asphalt collector was noticeable.

  16. Effect of Time and Temperature on Thickened Infant Formula.

    Science.gov (United States)

    Gosa, Memorie M; Dodrill, Pamela

    2017-04-01

    Unlike adult populations, who primarily depend on liquids for hydration alone, infants rely on liquids to provide them with hydration and nutrition. Speech-language pathologists working within pediatric medical settings often identify dysphagia in patients and subsequently recommend thickened liquids to reduce aspiration risk. Caregivers frequently report difficulty attempting to prepare infant formula to the prescribed thickness. This study was designed to determine (1) the relationship between consistencies in modified barium swallow studies and thickened infant formulas and (2) the effects of time and temperature on the resulting thickness of infant formula. Prepackaged barium consistencies and 1 standard infant formula that was thickened with rice cereal and with 2 commercially available thickening agents were studied. Thickness was determined via a line spread test after various time and temperature conditions were met. There were significant differences between the thickened formula and barium test consistencies. Formula thickened with rice cereal separated over time into thin liquid and solid residue. Formula thickened with a starch-based thickening agent was thicker than the desired consistency immediately after mixing, and it continued to thicken over time. The data from this project suggest that nectar-thick and honey-thick infant formulas undergo significant changes in flow rates within 30 minutes of preparation or if refrigerated and then reheated after 3 hours. Additional empirical evidence is warranted to determine the most reliable methods and safest products for thickening infant formula when necessary for effective dysphagia management.

  17. Effect of thermal phonons on the superconducting transition temperature

    International Nuclear Information System (INIS)

    Leavens, C.R.; Talbot, E.

    1983-01-01

    There is no consensus in the literature on whether or not thermal phonons depress the superconducting transition temperature T/sub c/. In this paper it is shown by accurate numerical solution of the real-frequency Eliashberg equations for the pairing self-energy phi and renormalization function Z that thermal phonons in the kernel for phi raise T/sub c/ but those in Z lower it by a larger amount so that the net effect is to depress T/sub c/. (A previous calculation which ignored the effect of thermal phonons in phi overestimated the suppression of T/sub c/ by at least a factor of 3.) It is shown how to switch off the thermal phonons in the imaginary-frequency Eliashberg equations, exactly for Z and approximately for phi. The real-frequency and approximate imaginary-frequency results for the depression of T/sub c/ by thermal phonons are in very satisfactory agreement. Thermal phonons are found to depress the transition temperature of Nb 3 Sn by only 2%. It is estimated that the suppression of T/sub c/ by thermal phonons saturates at about 50% in the limit of very strong electron-phonon coupling

  18. Temperature effects on lithium-nitrogen reaction rates

    International Nuclear Information System (INIS)

    Ijams, W.J.; Kazimi, M.S.

    1985-08-01

    A series of experiments have been run with the aim of measuring the reaction rate of lithium and nitrogen over a wide spectrum of lithium pool temperatures. In these experiments, pure nitrogen was blown at a controlled flow rate over a preheated lithium pool. The pool had a surface area of approximately 4 cm 2 and a total volume of approximately 6 cm 3 . The system pressure varied from 0 to 4 psig. The reaction rate was very small - approximately 0.002 to 0.003 g Li min cm 2 for lithium temperatures below 500 0 C. Above 500 0 C the reaction rate began to increase sharply, and reached a maximum of approximately 0.80 g Li min cm 2 above 700 0 C. It dropped off beyond 1000 0 C and seemed to approach zero at 1150 0 C. The maximum reaction rate observed in these forced convection experiments was higher by 60% than those previously observed in experiments where the nitrogen flowed to the reaction site by means of natural convection. During a reaction, a hard nitride layer built up on the surface of the lithium pool - its effect on the reaction rate was observed. The effect of the nitrogen flow rate on the reaction rate was also observed

  19. The precious metal effect in high temperature corrosion

    Energy Technology Data Exchange (ETDEWEB)

    Wit, J.H.W. de (Lab. for Materials Science, Delft Univ. of Technology (Netherlands)); Manen, P.A. van (Lab. for Materials Science, Delft Univ. of Technology (Netherlands))

    1994-01-01

    Additions of platinum and to a smaller extent rhodium, to aluminium oxide forming alloys are known to improve the high temperature corrosion resistance of the alloys. This effect is known as the ''precious metal effect''. The expensive Pt-additions are used because of the increased lifetime of turbine-vanes especially in marine environments. Only a limited number of coating systems is commercially available, as JML-1, LDC-2 and RT22. Normally Pt is deposited electrochemically or by a fused salt method. After deposition the high or low activity pack-cementation-process is applied to obtain a PtNiAl-coating. In this paper the effect of platinum on the oxidation mechanism is discussed by comparing the oxidation mechanism of [beta]-NiAl and Pt20Ni30Al50. This composition agrees with the average composition of a platinum modified aluminide coating. The alloys were oxidized at temperatures from 1000 to 1200 C. The growth of the oxide scale on the NiAl alloy proceeds both by aluminium and by oxygen diffusion through the scale resulting in growth within the scale. On Pt20Ni30Al50 the growth of the scale is limited to the oxide/gas interface due to a predominant aluminium transport through the scale. The morphology of the oxide scales did not show large differences. However, the extensive void formation at the [beta]-NiAl/oxide interface was not observed on the Pt20Ni30Al50 samples. The absence of voids at the interface and the reduction of growth stresses, as a result of the outward growth of the scale, are the two likely reasons for the improved oxide scale adherence and can thus be considered, to be two elements of the ''precious metal effect''. (orig.)

  20. Mutagenic effect of gamma radiation on Arabidopsis thaliana. Effect of low temperature and cytokinin

    International Nuclear Information System (INIS)

    Pesina, K.

    1975-01-01

    The effect was studied of low temperature and cytokinin (6-benzyl aminopurine) on sterility and mutation frequency in A r a b i d o ps i s t h a l i a n a irradiatied with gamma radiation. Liquid nitrogen temperature was found to modify the radiation effect in that that it reduced sterility and mutation frequency. Cytokinin applied to seed prior to and after irradiation increased mutation frequency. (L.O.)

  1. Preferred temperature and thermal breadth of birds wintering in peninsular Spain: the limited effect of temperature on species distribution

    Directory of Open Access Journals (Sweden)

    Luis M. Carrascal

    2016-07-01

    Full Text Available Background. The availability of environmental energy, as measured by temperature, is expected to limit the abundance and distribution of endotherms wintering at temperate latitudes. A prediction of this hypothesis is that birds should attain their highest abundances in warmer areas. However, there may be a spatial mismatch between species preferred habitats and species preferred temperatures, so some species might end-up wintering in sub-optimal thermal environments. Methods. We model the influence of minimum winter temperature on the relative abundance of 106 terrestrial bird species wintering in peninsular Spain, at 10 ×10 km2 resolution, using 95%-quantile regressions. We analyze general trends across species on the shape of the response curves, the environmental preferred temperature (at which the species abundance is maximized, the mean temperature in the area of distribution and the thermal breadth (area under the abundance-temperature curve. Results. Temperature explains a low proportion of variation in abundance. The most significant effect is on limiting the maximum potential abundance of species. Considering this upper-limit response, there is a large interspecific variability on the thermal preferences and specialization of species. Overall, there is a preponderance of positive relationships between species abundance and temperature; on average, species attain their maximum abundances in areas 1.9 °C warmer than the average temperature available in peninsular Spain. The mean temperature in the area of distribution is lower than the thermal preferences of the species. Discussion. Many species prefer the warmest areas to overwinter, which suggests that temperature imposes important restrictions to birds wintering in the Iberian Peninsula. However, one third of species overwinter in locations colder than their thermal preferences, probably reflecting the interaction between habitat and thermal requirements. There is a high inter

  2. Whole body immersion and hydromineral homeostasis: effect of water temperature.

    Science.gov (United States)

    Jimenez, Chantal; Regnard, Jacques; Robinet, Claude; Mourot, Laurent; Gomez-Merino, Danielle; Chennaoui, Mounir; Jammes, Yves; Dumoulin, Gilles; Desruelle, Anne-Virginie; Melin, Bruno

    2010-01-01

    This experiment was designed to assess the effects of prolonged whole body immersion (WBI) in thermoneutral and cold conditions on plasma volume and hydromineral homeostasis.10 navy "combat swimmers" performed three static 6-h immersions at 34 degrees C (T34), 18 degrees C (T18) and 10 degrees C (T10). Rectal temperature, plasma volume (PV) changes, plasma proteins, plasma and urine ions, plasma osmolality, renin, aldosterone and antidiuretic hormone (ADH) were measured. Results show that compared to pre-immersion levels, PV decreased throughout WBI sessions, the changes being markedly accentuated in cold conditions. At the end of WBI, maximal PV variations were -6.9% at T34, -14.3% at T18, and -16.3% at T10. Plasma osmolality did not change during and after T34 immersion, while hyperosmolality was present at the end of T18 immersion and began after only 1 h of T10 immersion. In the three temperature conditions, significant losses of water (1.6-1.7 l) and salt (6-8 g) occurred and were associated with similar increases in osmolar and free water clearances. Furthermore, T18 and T10 immersions increased the glomerular filtration rate. There was little or no change in plasma renin and ADH, while the plasma level of aldosterone decreased equally in the three temperature conditions. In conclusion, our data indicate that cold water hastened PV changes induced by immersion, and increased the glomerular filtration rate, causing larger accumulated water losses. The iso-osmotic hypovolemia may impede the resumption of baseline fluid balance. Results are very similar to those repeatedly described by various authors during head-out water immersion.

  3. Total Dose Effects on Bipolar Integrated Circuits at Low Temperature

    Science.gov (United States)

    Johnston, A. H.; Swimm, R. T.; Thorbourn, D. O.

    2012-01-01

    Total dose damage in bipolar integrated circuits is investigated at low temperature, along with the temperature dependence of the electrical parameters of internal transistors. Bandgap narrowing causes the gain of npn transistors to decrease far more at low temperature compared to pnp transistors, due to the large difference in emitter doping concentration. When irradiations are done at temperatures of -140 deg C, no damage occurs until devices are warmed to temperatures above -50 deg C. After warm-up, subsequent cooling shows that damage is then present at low temperature. This can be explained by the very strong temperature dependence of dispersive transport in the continuous-time-random-walk model for hole transport. For linear integrated circuits, low temperature operation is affected by the strong temperature dependence of npn transistors along with the higher sensitivity of lateral and substrate pnp transistors to radiation damage.

  4. Effect of evaporator temperature on vapor compression refrigeration system

    Directory of Open Access Journals (Sweden)

    Abdullah A.A.A. Al-Rashed

    2011-12-01

    Full Text Available This paper presents a comparable evaluation of R600a (isobutane, R290 (propane, R134a, R22, for R410A, and R32 an optimized finned-tube evaporator, and analyzes the evaporator effect on the system coefficient of performance (COP. Results concerning the response of a refrigeration system simulation software to an increase in the amount of oil flowing with the refrigerant are presented. It is shown that there is optima of the apparent overheat value, for which either the exchanged heat or the refrigeration coefficient of performance (COP is maximized: consequently, it is not possible to optimize both the refrigeration COP and the evaporator effect. The obtained evaporator optimization results were incorporated in a conventional analysis of the vapor compression system. For a theoretical cycle analysis without accounting for evaporator effects, the COP spread for the studied refrigerants was as high as 11.7%. For cycle simulations including evaporator effects, the COP of R290 was better than that of R22 by up to 3.5%, while the remaining refrigerants performed approximately within a 2% COP band of the R22 baseline for the two condensing temperatures considered.

  5. Temperature induced effects on the durability of MR fluids

    International Nuclear Information System (INIS)

    Wiehe, A; Maas, J; Kieburg, C

    2013-01-01

    Although commercial MR fluids exist for quite some time now and the feasibility as well as the advantages of the MR technology have been demonstrated for several applications by a variety of MR actuator prototypes, a sustainable market break-through of brake and clutch applications utilizing the shear mode is still missing. Essential impediments are the marginal knowledge about the durability of the MR technology. To overcome this situation, a long-term measurement system was developed for the durability analysis of MR fluid formulations within a technical relevant scale with respect to the volume of MR fluid and the transmitted torque. The focus of the presented series of measurements is given to the analysis of temperature induced effects on the durability. In this context four different failure indicators can be distinguished, namely an apparent negative viscosity, deviations in torque data obtained from different measurements as well as a pressure increase and a drop in the on-state torque. The measurement data of the present durability experiments indicate a significant dependency of the attainable energy intake density on the temperature. The aim of such durability tests is to establish a reliable data base for the industry to estimate the life-time of MR devices.

  6. Effect of temperature stress on protein methyl esters

    International Nuclear Information System (INIS)

    Welch, W.; Kracaw, K.

    1986-01-01

    Protein methyl esters have been implicated in a number of physiological processes. They have measured the effect of temperature stress on the levels of protein methyl esters in the mesophilic fungus Penicillium chrysogenum (PCPS) and the thermophilic fungus P. duponti (PD). PD and PCPS were incubated with [methyl- 3 H]methionine. The mycelia were collected by filtration, frozen in liquid nitrogen and ground to a fine powder. The nitrogen powder was extracted with either phosphate buffer or with SDS, glycerol, phosphate, 2-mercaptoethanol. Insoluble material was removed by centrifugation. The supernatants were assayed for protein methyl esters. The released [ 3 H]methanol was extracted into toluene:isoamyl alcohol (3:2) and quantitated by liquid scintillation. The production of volatile methanol was confirmed by use of Conway diffusion cells. Soluble proteins accounted for about one-fourth of the total protein methyl ester extracted by SDS. In PCPS, the SDS extracted proteins have about three times the level of esterification of the soluble proteins whereas in PD there is little difference between soluble and SDS extracted protein. The level of protein esterification in PD is about one-tenth that observed in PCPS. Temperature stress caused large changes in the level of protein esterification. The data suggest protein methyl esters may contribute to the adaptation to environmental stress

  7. Shape Effect on the Temperature Field during Microwave Heating Process

    Directory of Open Access Journals (Sweden)

    Zhijun Zhang

    2018-01-01

    Full Text Available Aiming at improving the food quality during microwave process, this article mainly focused on the numerical simulation of shape effect, which was evaluated by microwave power absorption capability and temperature distribution uniformity in a single sample heated in a domestic microwave oven. This article only took the electromagnetic field and heat conduction in solid into consideration. The Maxwell equations were used to calculate the distribution of microwave electromagnetic field distribution in the microwave cavity and samples; then the electromagnetic energy was coupled as the heat source in the heat conduction process in samples. Quantitatively, the power absorption capability and temperature distribution uniformity were, respectively, described by power absorption efficiency (PAE and the statistical variation of coefficient (COV. In addition, we defined the comprehensive evaluation coefficient (CEC to describe the usability of a specific sample. In accordance with volume or the wave numbers and penetration numbers in the radial and axial directions of samples, they can be classified into different groups. And according to the PAE, COV, and CEC value and the specific need of microwave process, an optimal sample shape and orientation could be decided.

  8. Theory of static friction: temperature and corrugation effects

    International Nuclear Information System (INIS)

    Franchini, A; Brigazzi, M; Santoro, G; Bortolani, V

    2008-01-01

    We present a study of the static friction, as a function of temperature, between two thick solid slabs. The upper one is formed of light particles and the substrate of heavy particles. We focus our attention on the interaction between the phonon fields of the two blocks and on the interface corrugation, among the various mechanisms responsible for the friction. To give evidence of the role played by the dynamical interaction of the substrate with the upper block, we consider both a substrate formed by fixed atoms and a substrate formed by mobile atoms. To study the effect of the corrugation, we model it by changing the range parameter σ in the Lennard-Jones interaction potential. We found that in the case of the mobile substrate there is a large momentum transfer from the substrate to the upper block. This momentum transfer increases on increasing the temperature and produces a large disorder in the upper block favouring a decrease of the static friction with respect to the case for a rigid substrate. Reducing the corrugation, we found that with a rigid substrate the upper block becomes nearly commensurate, producing an enhancement of the static friction with respect to that with a mobile substrate

  9. Heating temperature effect on ferritic grain size of rotor steel

    International Nuclear Information System (INIS)

    Cheremnykh, V.G.; Derevyankin, E.V.; Sakulin, A.A.

    1983-01-01

    The heating temperature effect on ferritic grain size of two steels 13Kh1M1FA and 25Kh1M1FA is evaluated. It is shown that exposure time increase at heating temperatures below 1000 deg C up to 10h changes but slightly the size of the Cr-Mo-V ferritic grain of rotor steel cooled with 25 deg C/h rate. Heating up to 1000 deg C and above leads to substantial ferritic grain growth. The kinetics of ferritic grain growth is determined by the behaviour of phases controlling the austenitic grain growth, such as carbonitrides VCsub(0.14)Nsub(0.78) in 13Kh1M1FA steel and VCsub(0.18)Nsub(0.72) in 25Kh1M1FA steel. Reduction of carbon and alloying elements content in steel composition observed at the liquation over rotor length leads to a certain decrease of ferritic grain resistance to super heating

  10. Historical effects of temperature and precipitation on California crop yields

    Energy Technology Data Exchange (ETDEWEB)

    Lobell, D.B. [Energy and Environment Directorate, Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States); Cahill, K.N. [Interdisciplinary Graduate Program in Environment and Resources, Stanford University, Stanford, CA 94305 (United States); Field, C.B. [Department of Global Ecology, Carnegie Institution, Stanford, CA 94305 (United States)

    2007-03-15

    For the 1980-2003 period, we analyzed the relationship between crop yield and three climatic variables (minimum temperature, maximum temperature, and precipitation) for 12 major Californian crops: wine grapes, lettuce, almonds, strawberries, table grapes, hay, oranges, cotton, tomatoes, walnuts, avocados, and pistachios. The months and climatic variables of greatest importance to each crop were used to develop regressions relating yield to climatic conditions. For most crops, fairly simple equations using only 2-3 variables explained more than two-thirds of observed yield variance. The types of variables and months identified suggest that relatively poorly understood processes such as crop infection, pollination, and dormancy may be important mechanisms by which climate influences crop yield. Recent climatic trends have had mixed effects on crop yields, with orange and walnut yields aided, avocado yields hurt, and most crops little affected by recent climatic trends. Yield-climate relationships can provide a foundation for forecasting crop production within a year and for projecting the impact of future climate changes.

  11. The effect of stress on core and peripheral body temperature in humans.

    Science.gov (United States)

    Vinkers, Christiaan H; Penning, Renske; Hellhammer, Juliane; Verster, Joris C; Klaessens, John H G M; Olivier, Berend; Kalkman, Cor J

    2013-09-01

    Even though there are indications that stress influences body temperature in humans, no study has systematically investigated the effects of stress on core and peripheral body temperature. The present study therefore aimed to investigate the effects of acute psychosocial stress on body temperature using different readout measurements. In two independent studies, male and female participants were exposed to a standardized laboratory stress task (the Trier Social Stress Test, TSST) or a non-stressful control task. Core temperature (intestinal and temporal artery) and peripheral temperature (facial and body skin temperature) were measured. Compared to the control condition, stress exposure decreased intestinal temperature but did not affect temporal artery temperature. Stress exposure resulted in changes in skin temperature that followed a gradient-like pattern, with decreases at distal skin locations such as the fingertip and finger base and unchanged skin temperature at proximal regions such as the infra-clavicular area. Stress-induced effects on facial temperature displayed a sex-specific pattern, with decreased nasal skin temperature in females and increased cheek temperature in males. In conclusion, the amplitude and direction of stress-induced temperature changes depend on the site of temperature measurement in humans. This precludes a direct translation of the preclinical stress-induced hyperthermia paradigm, in which core temperature uniformly rises in response to stress to the human situation. Nevertheless, the effects of stress result in consistent temperature changes. Therefore, the present study supports the inclusion of body temperature as a physiological readout parameter of stress in future studies.

  12. Bias temperature instability in tunnel field-effect transistors

    Science.gov (United States)

    Mizubayashi, Wataru; Mori, Takahiro; Fukuda, Koichi; Ishikawa, Yuki; Morita, Yukinori; Migita, Shinji; Ota, Hiroyuki; Liu, Yongxun; O'uchi, Shinichi; Tsukada, Junichi; Yamauchi, Hiromi; Matsukawa, Takashi; Masahara, Meishoku; Endo, Kazuhiko

    2017-04-01

    We systematically investigated the bias temperature instability (BTI) of tunnel field-effect transistors (TFETs). The positive BTI and negative BTI mechanisms in TFETs are the same as those in metal-oxide-semiconductor FETs (MOSFETs). In TFETs, although traps are generated in high-k gate dielectrics by the bias stress and/or the interface state is degraded at the interfacial layer/channel interface, the threshold voltage (V th) shift due to BTI degradation is caused by the traps and/or the degradation of the interface state locating the band-to-band tunneling (BTBT) region near the source/gate edge. The BTI lifetime in n- and p-type TFETs is improved by applying a drain bias corresponding to the operation conditions.

  13. Temperature and fluence effects in lead implanted cobalt single crystals

    International Nuclear Information System (INIS)

    Johansen, A.; Sarholt-Kristensen, L.; Johnson, E.; Steenstrup, S.; Chernysh, V.S.

    1988-01-01

    The channeled sputtering yields of the hcp and fcc phases of cobalt depend on the crystal structure and the radiation induced damage. Earlier irradiations of cobalt with argon ions channeled in the hcp direction give sputtering yields higher than expected in the temperature range 100-350deg C. This effect was attributed to a combination of radiation induced damage and a possible implantation induced hcp --> fcc phase transition. Sputtering yields for cobalt single crystals irradiated with 150 keV Pb + ions along the direction of the hcp phase and the direction of the fcc phase have been measured using the weightloss method. The radiation damage and the amount of lead retained in the implanted surface has been investigated by 'in situ' RBS/channeling analysis. Measured partial sputtering yields of lead ≅ 1 atom/ion indicate preferential sputtering of lead atoms. (orig.)

  14. Quantum effects on the temperature relaxation in plasmas

    International Nuclear Information System (INIS)

    Sakai, Kazuo; Aono, Osamu.

    1979-03-01

    This work was carried out under the collaborating Research Program at Institute of Plasma Physics, Nagoya University. Further communication about this report is to be sent to the Research Information Center, Institute of Plasma Physics, Nagoya University, Nagoya 464, Japan. The rate of equilibration of difference between the ion and electron temperatures is obtained on the basis of the unified theory, in which the collective and binary interactions are both treated properly. The electrons obey the Fermi distribution of arbitrary degeneracy. The rate decreases owing to the degeneracy. Even in the nondegenerated case, the quantum effect appeares in the argument of the Coulomb logarithm. When the de Broglie wave length of the electron is much longer than the radius of close collision, the results agree with those obtained on the Born approximation. In the opposite limit, the classical theory applies. For other cases, graphical examples are given. (author)

  15. Chemical composition and effective temperatures of metallic line white dwarfs

    International Nuclear Information System (INIS)

    Hammond, G.L.

    1974-01-01

    Model atmosphere techniques have been employed to determine the composition, effective temperatures, radii, masses and surface gravities of white dwarfs Ross 640 and van Maanen 2. The non-gray, LTE, convective, constant flux models employed collisional damping constants for the Ca II H and K lines that were measured in a laboratory device that simulated white dwarf atmospheric conditions. Ross 640 was found to have an extremely helium-rich composition and T/sub eff/ = 8500K, while the observed properties of van Maanen 2 were fitted best by a model with 91 percent helium, 9 percent hydrogen and T/sub eff/ = 6100K. The laboratory measurements of pressure shifts for the Ca II lines casts some doubt on the interpretation of recent radial velocity determinations for van Maanen 2. (U.S.)

  16. Radiation effects on epoxy composites at cryogenic temperatures

    International Nuclear Information System (INIS)

    Yamaoka, H.; Miyata, K.; Nishijima, S.; Okada, T.

    1995-01-01

    Radiation effects on glass-fiber reinforced epoxy composites at cryogenic temperatures has been studied by measuring the changes in interlaminar shear strength of the specimens. The scanning electron microscope observation has also been performed on fracture surface of the specimens. At 8.5 MGy of absorbed dose, only 10 % decrease of the strength was observed in the case of gamma irradiation, whereas over 80 % decrease of the strength was found on the reactor irradiated specimen. The difference of degradation behavior between gamma and reactor irradiations is attributed to the additional absorbed dose in the latter from the nuclear reaction due to boron-10 contained in the glass fibers by capture of thermal neutrons. (author)

  17. Effects of early and chronic exposure to high temperatures on ...

    African Journals Online (AJOL)

    Jane

    2011-09-28

    Sep 28, 2011 ... temperature on growth performance, carcass parameters, fatty acid deposition and composition of ... breeding, a decreased weight of pectoral muscle (PM) associated .... These temperatures are often associated with lower.

  18. Effect of varying temperature on growth, morphology and soluble ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-05-16

    May 16, 2008 ... High temperature severely affects cell morphology (cell size, cell types, formation of filaments/minicells ... media (Anagnostopolous and Spizezen, 1961) were used. .... inactivation of fts Z (filamentous temperature sensitive).

  19. Effect of substrate temperature on electrical and magnetic properties ...

    Indian Academy of Sciences (India)

    . Figure 1. The temperature dependence of resistivity for LPMO films grown at different substrate temperatures (solid and open circles are the data in zero and 1 T magnetic field). The inset shows the variation of magnetoresistance with ...

  20. Thermal fluctuation effects far from the critical temperature

    International Nuclear Information System (INIS)

    Refai, T.F.

    1980-01-01

    We report the first measurements of thermal fluctuations in superconductors at temperatures far from the critical temperature T/sub c/ (T approx. 1/2 T/sub c/), and also the first measurements that use thermal fluctuations to probe the non-equilibrium dynamics of a superconductor. This is the first work that separately measures the fluctuations that cause a superconductor to switch to the dissipative state and those that cause it to switch back to the superconductor state. These unique measurements allowed: (1) The first measurement experimental confirmation of the theory of Langer, Ambegaokar, McCumber, and Halperin (LAMH) where T/sub c/ was not an adjustable parameter. This rigorous test of the theory was not previously possible because earlier measurements were carried out very near T/sub c/, where a change of many orders of magnitude of predicted effects occur if the assumed T/sub c/ changes a few millidegrees. Thus T/sub c/ in all previous work was always adjusted so as to get agreement with the theory. (2) The first verification of the LAMH model far from T/sub c/. (3) The first experimental confirmation of the relation between current and transition probability that was predicted in the LAMH model. (4) Confirmation that the Lamda model developed by Peters, Wolf, and Rachford (PWR) to explain the dynamics on the nonequilibrium region can be extended to explain fluctuation effects. This is based on an original phenomenological extension of the LAMH model that is developed in this work and on our data. (5) The most direct measurement to date of the nature of the decay of the dissipative region in a weak link. These measurements show that the region recovers exponentially in time as proposed in the Lamda model

  1. Effects of temperature and copper pollution on soil community--extreme temperature events can lead to community extinction.

    Science.gov (United States)

    Menezes-Oliveira, Vanessa B; Scott-Fordsmand, Janeck J; Soares, Amadeu M V M; Amorim, Monica J B

    2013-12-01

    Global warming affects ecosystems and species' diversity. The physiology of individual species is highly influenced by changes in temperature. The effects on species communities are less studied; they are virtually unknown when combining effects of pollution and temperature. To assess the effects of temperature and pollution in the soil community, a 2-factorial soil mesocosms multispecies experiment was performed. Three exposure periods (28 d, 61 d, and 84 d) and 4 temperatures (19 °C, 23 °C, 26 °C, and 29 °C) were tested, resembling the mean annual values for southern Europe countries and extreme events. The soil used was from a field site, clean, or spiked with Cu (100 mg Cu/kg). Results showed clear differences between 29 °C treatment and all other temperature treatments, with a decrease in overall abundance of organisms, further potentiated by the increase in exposure time. Folsomia candida was the most abundant species and Enchytraeus crypticus was the most sensitive to Cu toxicity. Differences in species optimum temperatures were adequately covered: 19 °C for Hypoaspis aculeifer or 26 °C for E. crypticus. The temperature effects were more pronounced the longer the exposure time. Feeding activity decreased with higher temperature and exposure time, following the decrease in invertebrate abundance, whereas for the same conditions the organic matter turnover increased. Hence, negative impacts on ecosystem services because of temperature increase can be expected by changes on soil function and as consequence of biodiversity loss. © 2013 SETAC.

  2. The effect of low temperature cryocoolers on the development of low temperature superconducting magnets

    International Nuclear Information System (INIS)

    Green, Michael A.

    2000-01-01

    The commercial development of reliable 4 K cryocoolers improves the future prospects for magnets made from low temperature superconductors (LTS). The hope of the developers of high temperature superconductors (HTS) has been to replace liquid helium cooled LTS magnets with HTS magnets that operate at or near liquid nitrogen temperature. There has been limited success in this endeavor, but continued problems with HTS conductors have greatly slowed progress toward this goal. The development of cryocoolers that reliably operate below 4 K will allow magnets made from LTS conductor to remain very competitive for many years to come. A key enabling technology for the use of low temperature cryocoolers on LTS magnets has been the development of HTS leads. This report describes the characteristics of LTS magnets that can be successfully melded to low-temperature cryocoolers. This report will also show when it is not appropriate to consider the use of low-temperature cryocoolers to cool magnets made with LTS conductor. A couple of specific examples of LTS magnets where cryocoolers can be used are given

  3. Effect of temperature on continuous dry fermentation of swine manure.

    Science.gov (United States)

    Deng, Liangwei; Chen, Chuang; Zheng, Dan; Yang, Hongnan; Liu, Yi; Chen, Ziai

    2016-07-15

    Laboratory-scale experiments were performed on the dry digestion of solid swine manure in a semi-continuous mode using 4.5 L down plug-flow anaerobic reactors with an organic loading rate of 3.46 kg volatile solids (VS) m(-3) d(-1) to evaluate the effects of temperature (15, 25 and 35 °C). At 15 °C, biogas production was the poorest due to organic overload and acidification, with a methane yield of 0.036 L CH4 g(-1) VS added and a volumetric methane production rate of 0.125 L CH4 L(-1) d(-1). The methane yield and volumetric methane production rate at 25 °C (0.226 L CH4 g(-1) VS added and 0.783 L CH4 L(-1) d(-1), respectively) were 6.24 times higher than those at 15 °C. However, the methane yield (0.237 L CH4 g(-1) VS added) and the volumetric methane production rate (0.821 L CH4 L(-1) d(-1)) at 35 °C were only 4.86% higher than those at 25 °C, which indicated similar results were obtained at 25 °C and 35 °C. The lower biogas production at 35 °C in dry digestion compared with that in wet digestion could be attributed to ammonia inhibition. For a single pig farm, digestion of solid manure is accomplished in small-scale domestic or small-farm bioreactors, for which operating temperatures of 35 °C are sometimes difficult to achieve. Considering biogas production, ammonia inhibition and net energy recovery, an optimum temperature for dry digestion of solid swine manure is 25 °C. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Urban climate effects on extreme temperatures in Madison, Wisconsin, USA

    Science.gov (United States)

    Schatz, Jason; Kucharik, Christopher J.

    2015-09-01

    As climate change increases the frequency and intensity of extreme heat, cities and their urban heat island (UHI) effects are growing, as are the urban populations encountering them. These mutually reinforcing trends present a growing risk for urban populations. However, we have limited understanding of urban climates during extreme temperature episodes, when additional heat from the UHI may be most consequential. We observed a historically hot summer and historically cold winter using an array of up to 150 temperature and relative humidity sensors in and around Madison, Wisconsin, an urban area of population 402 000 surrounded by lakes and a rural landscape of agriculture, forests, wetlands, and grasslands. In the summer of 2012 (third hottest since 1869), Madison’s urban areas experienced up to twice as many hours ⩾32.2 °C (90 °F), mean July TMAX up to 1.8 °C higher, and mean July TMIN up to 5.3 °C higher than rural areas. During a record setting heat wave, dense urban areas spent over four consecutive nights above the National Weather Service nighttime heat stress threshold of 26.7 °C (80 °F), while rural areas fell below 26.7 °C nearly every night. In the winter of 2013-14 (coldest in 35 years), Madison’s most densely built urban areas experienced up to 40% fewer hours ⩽-17.8 °C (0 °F), mean January TMAX up to 1 °C higher, and mean January TMIN up to 3 °C higher than rural areas. Spatially, the UHI tended to be most intense in areas with higher population densities. Temporally, both daytime and nighttime UHIs tended to be slightly more intense during more-extreme heat days compared to average summer days. These results help us understand the climates for which cities must prepare in a warming, urbanizing world.

  5. Global Cooling: Effect of Urban Albedo on Global Temperature

    Energy Technology Data Exchange (ETDEWEB)

    Akbari, Hashem; Menon, Surabi; Rosenfeld, Arthur

    2007-05-22

    In many urban areas, pavements and roofs constitute over 60% of urban surfaces (roof 20-25%, pavements about 40%). The roof and the pavement albedo can be increased by about 0.25 and 0.10, respectively, resulting in a net albedo increase for urban areas of about 0.1. Many studies have demonstrated building cooling-energy savings in excess of 20% upon raising roof reflectivity from an existing 10-20% to about 60%. We estimate U.S. potential savings in excess of $1 billion (B) per year in net annual energy bills. Increasing albedo of urban surfaces can reduce the summertime urban temperature and improve the urban air quality. Increasing the urban albedo has the added benefit of reflecting more of the incoming global solar radiation and countering the effect of global warming. We estimate that increasing albedo of urban areas by 0.1 results in an increase of 3 x 10{sup -4} in Earth albedo. Using a simple global model, the change in air temperature in lowest 1.8 km of the atmosphere is estimated at 0.01K. Modelers predict a warming of about 3K in the next 60 years (0.05K/year). Change of 0.1 in urban albedo will result in 0.01K global cooling, a delay of {approx}0.2 years in global warming. This 0.2 years delay in global warming is equivalent to 10 Gt reduction in CO2 emissions.

  6. PWR clad ballooning: The effect of circumferential clad temperature variations on the burst strain/burst temperature relationship

    International Nuclear Information System (INIS)

    Barlow, P.

    1983-01-01

    By experiment, it has been shown by other workers that there is a reduction in the creep ductility of Zircaloy 4 in the α+β phase transition region. Results from single rod burst tests also show a reduction in burst strain in the α+β phase region. In this report it is shown theoretically that for single rod burst tests in the presence of circumferential temperature gradients, the temperature dependence of the mean burst strain is not determined by temperature variations in creep ductility, but is governed by the temperature sensitivity of the creep strain rate, which is shown to be a maximum in the α+β phase transition region. To demonstrate this effect, the mean clad strain at burst was calculated for creep straining at different temperature levels in the α, α+β and β phase regions. Cross-pin temperature gradients were applied which produced strain variations around the clad which were greatest in the α+β phase region. The mean strain at burst was determined using a maximum local burst strain (i.e. a creep ductility) which is independent of temperature. By assuming cross-pin temperature gradients which are typical of those observed during burst tests, then the calculated mean burst strain/burst temperature relationship gave good agreement with experiment. The calculations also show that when circumferential temperature differences are present, the calculated mean strain at burst is not sensitive to variations in the magnitude of the assumed creep ductility. This reduces the importance of the assumed burst criterion in the calculations. Hence a temperature independent creep ductility (e.g. 100% local strain) is adequate as a burst criterion for calculations under PWR LOCA conditions. (author)

  7. High-temperature gas effects on aerodynamic characteristics of waverider

    Directory of Open Access Journals (Sweden)

    Jun Liu

    2015-02-01

    Full Text Available This paper focuses on the analysis of high-temperature effect on a conical waverider and it is a typical configuration of near space vehicles. Two different gas models are used in the numerical simulations, namely the thermochemical non-equilibrium and perfect gas models. The non-equilibrium flow simulations are conducted with the usage of the parallel non-equilibrium program developed by the authors while the perfect gas flow simulations are carried out with the commercial software Fluent. The non-equilibrium code is validated with experimental results and grid sensitivity analysis is performed as well. Then, numerical simulations of the flow around the conical waverider with the two gas models are conducted. In the results, differences in the flow structures as well as aerodynamic performances of the conical waverider are compared. It is found that the thermochemical non-equilibrium effect is significant mainly near the windward boundary layer at the tail of the waverider, and the non-equilibrium influence makes the pressure center move forward to about 0.57% of the whole craft’s length at the altitude of 60 km.

  8. Size, Shape and Impurity Effects on Superconducting critical temperature.

    Science.gov (United States)

    Umeda, Masaki; Kato, Masaru; Sato, Osamu

    Bulk superconductors have their own critical temperatures Tc. However, for a nano-structured superconductor, Tc depends on size and shape of the superconductor. Nishizaki showed that the high pressure torsion on bulks of Nb makes Tc higher, because the torsion makes many nano-sized fine grains in the bulks. However the high pressure torsion on bulks of V makes Tc lower, and Nishizaki discussed that the decrease of Tc is caused by impurities in the bulks of V. We studied size, shape, and impurity effects on Tc, by solving the Gor'kov equations, using the finite element method. We found that smaller and narrower superconductors show higher Tc. We found how size and shape affects Tc by studying spacial order parameter distributions and quasi-particle eigen-energies. Also we studied the impurity effects on Tc, and found that Tc decreases with increase of scattering rate by impurities. This work was supported in part of KAKENHI Grant Number JP26400367 and JP16K05460, and program for leading graduate schools of ministry of education, culture, sports, science and technology-Japan.

  9. Effect of Temperature on the Intrinsic Flexibility of DNA and Its Interaction with Architectural Proteins

    NARCIS (Netherlands)

    Driessen, R.P.C.; Sitter, G.; Moolenaar, G.F.; Wuite, G.J.L.; Goosen, N.; Dame, R.T.

    2014-01-01

    The helical structure of double-stranded DNA is destabilized by increasing temperature. Above a critical temperature (the melting temperature), the two strands in duplex DNA become fully separated. Below this temperature, the structural effects are localized. Using tethered particle motion in a

  10. Temperature shift effect on the Chlorobaculum tepidum chlorosomes.

    Science.gov (United States)

    Tang, Joseph Kuo-Hsiang; Xu, Ying; Muhlmann, Guillermo M; Zare, Farrokh; Khin, Yadana; Tam, Sun W

    2013-05-01

    Chlorobaculum [Cba.] tepidum is known to grow optimally at 48-52 °C and can also be cultured at ambient temperatures. In this paper, we prepared constant temperature, temperature shift, and temperature shift followed by backshift cultures and investigated the intrinsic properties and spectral features of chlorosomes from those cultures using various approaches, including temperature-dependent measurements on circular dichroism (CD), UV-visible, and dynamic light scattering. Our studies indicate that (1) chlorosomes from constant temperature cultures at 50 and 30 °C exhibited more resistance to heat relative to temperature shift cultures; (2) as temperature increases bacteriochlorophyll c (BChl c) in chlorosomes is prone to demetalation, which forms bacteriopheophytin c, and degradation under aerobic conditions. Some BChl c aggregates inside reduced chlorosomes prepared in low-oxygen environments can reform after heat treatments; (3) temperature shift cultures synthesize and incorporate more BChl c homologs with a smaller substituent at C-8 on the chlorin ring and less BChl c homologs with a larger long-chain alcohol at C-17(3) versus constant-temperature cultures. We hypothesize that the long-chain alcohol at C-17(3) (and perhaps together with the substituent at C-8) may account for thermal stability of chlorosomes and the substituent at C-8 may assist self-assembling BChls; and (4) while almost identical absorption spectra are detected, chlorosomes from different growth conditions exhibited differences in the rotational length of the CD signal, and aerobic and reduced chlorosomes also display different Qy CD intensities. Further, chlorosomes exhibited changes of CD features in response to temperature increases. Additionally, we compare temperature-dependent studies for the Cba. tepidum chlorosomes and previous studies for the Chloroflexus aurantiacus chlorosomes. Together, our work provides useful and novel insights on the properties and organization of

  11. Effect of temperature on MRPC with pad read-outs

    International Nuclear Information System (INIS)

    Ding Weicheng; Wang Yi; Chen Huangshan; Wang Jingbo; Tuo Xianguo; Wang Min

    2013-01-01

    To obtain a quantitative understanding of the influence of temperature on the performance of multi-gap resistive plate chambers (MRPCs), we have tested the performance of a 10-gap, 12-pad, 2×2×12 cm 2 active area MRPC at different temperatures with cosmic rays. Presented are results from measurements of high-voltage scans, noise rate, dark current, streamer, time resolution, count rate, charge spectrum, and detection efficiency. The test results show that the MRPC performance is significantly affected by temperature arising from the temperature-dependence of the glass resistivity. (authors)

  12. Measurements of effective noise temperature in fused silica fiber violin modes

    Energy Technology Data Exchange (ETDEWEB)

    Bilenko, I.A.; Lourie, S.L

    2002-11-25

    The results of measurements of the effective noise temperature in fused silica fiber violin modes are presented. In these measurements the fibers were stressed and value of the effective noise temperature was obtained by direct observation of oscillations in the fundamental violin modes of several samples. Measured values indicate that effective noise temperature does not exceed the room temperature significantly. This result is important for the design of the advanced gravitational wave antennae.

  13. Temperature is the evil twin: effects of increased temperature and ocean acidification on reproduction in a reef fish.

    Science.gov (United States)

    Miller, G M; Kroon, F J; Metcalfe, S; Mundayi, P L

    2015-04-01

    Reproduction in many organisms can be disrupted by changes to the physical environment, such as those predicted to occur during climate change. Marine organisms face the dual climate change threats of increasing temperature and ocean acidification, yet no studies have examined the potential interactive effects of these stressors on reproduction in marine fishes. We used a long-term experiment to test the interactive effects of increased temperature and CO2 on the reproductive performance of the anemonefish, Amphiprion melanopus. Adult breeding pairs were kept for 10 months at three temperatures (28.5°C [+0.0°C], 30.0°C [-1.5°C] and 31.5°C [+3.0°C]) cross-factored with three CO2 levels (a current-day control [417 µatm] and moderate [644 µatm] and high [1134 µatm]) treatments consistent with the range of CO2 projections for the year 2100. We recorded each egg clutch produced during the breeding season, the number of eggs laid per clutch, average egg size, fertilization success, survival to hatching, hatchling length, and yolk provisioning. Adult body condition, hepatosomatic index, gonadosomatic index, and plasma 17β-estradiol concentrations were measured at the end of the breeding season to determine the effect of prolonged exposure to increased temperature and elevated. CO2 on adults, and to examine potential physiological mechanisms for changes in reproduction. Temperature had by far the stronger influence on reproduction, with clear declines in reproduction occurring in the +1.5°C treatment and ceasing altogether in the +3.0°C treatment. In contrast, CO2 had a minimal effect on the majority of reproductive traits measured, but caused a decline in offspring quality in combination with elevated temperature. We detected no significant effect of temperature or Co2 on adult body condition or hepatosomatic index. Elevated temperature had a significant negative effect on plasma 17β-estradiol concentrations, suggesting that declines in reproduction with

  14. Effects of strain rate and temperature on deformation behaviour of IN 718 during high temperature deformation

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, L X [Dept. of Metallurgy and Engineering Materials, Univ. of Strathclyde, Glasgow (United Kingdom); Baker, T N [Dept. of Metallurgy and Engineering Materials, Univ. of Strathclyde, Glasgow (United Kingdom)

    1994-04-15

    The hot deformation characteristics of a wrought IN 718 alloy were investigated by compression testing at constant strain rates in the range of 0.1 to 5 x 10[sup -3] s[sup -1], and testing temperatures in the range of 950 to 1100 C using a 200 ton capacity microprocessor controlled Fielding hydraulic press. Examination of the microstructures was carried out by optical microscopy and TEM. The flow stress of the compression tests showed a single peak in the flow stress-strain curves, and indicated that a dynamic recrystallization transition took place during the hot compression. The relationship between the peak stresses ([sigma][sub p]) and the Zener-Hollomon parameter (z) can be expressed by [sigma][sub p] = 0.5 Z[sup 0.17]. Necklace'' microstructures were observed at testing temperatures below 1050 C, for strain of 0.7. The fraction of recrystallized grains increased with the increasing temperature and strain, and decreasing strain rate. Fully recrystallized microstructures were observed at temperatures 1050 C or greater, with a strain of 0.7. (orig.)

  15. Low temperature irradiation effects on plastic deformation in BCC metals

    International Nuclear Information System (INIS)

    Aono, Yasuhisa

    1984-01-01

    Low temperature electron beam experiment was carried out on high purity iron and molybdenum single crystals, and its effect on the plastic deformation was examined. As the characteristics of the irradiated iron below 77 K, remarkable softening occurred in all orientations. This phenomenon is based on the interaction of self interstitial atoms and screw dislocations, and the other features such as the absorption of interstitial atoms into screw dislocations and the slip on maximum shearing stress planes were shown. On the other hand, the aggregate of interstitial atoms formed by annealing showed the different plastic characteristics from those of interstitial atoms, and gave the results corresponding to respective stages of the electric resistance recovery curves. Regarding molybdenum, the transfer of its self interstitial atoms is near 40 K, therefore at 77 K, cluster is formed, and it largely affects abnormal slip, which is one of the features of the plasticity of molybdenum. The peculiar dependence of the yield stress on the crystalline orientation was shown. The property of the interaction of the aggregate of interstitial atoms formed and grown by the annealing from 77 K to 500 K with dislocations corresponded to the information of defects obtained by the X-ray research of Maeta, and the similarity to the aggregate of iron was observed. (Kako, I.)

  16. The Effect of Temperature on the Gasification Process

    Directory of Open Access Journals (Sweden)

    Marek Baláš

    2012-01-01

    Full Text Available Gasification is a technology that uses fuel to produce power and heat. This technology is also suitable for biomass conversion. Biomass is a renewable energy source that is being developed to diversify the energy mix, so that the Czech Republic can reduce its dependence on fossil fuels and on raw materials for energy imported from abroad. During gasification, biomass is converted into a gas that can then be burned in a gas burner, with all the advantages of gas combustion. Alternatively, it can be used in internal combustion engines. The main task during gasification is to achieve maximum purity and maximum calorific value of the gas. The main factors are the type of gasifier, the gasification medium, biomass quality and, last but not least, the gasification mode itself. This paper describes experiments that investigate the effect of temperature and pressure on gas composition and low calorific value. The experiments were performed in an atmospheric gasifier in the laboratories of the Energy Institute atthe Faculty of Mechanical Engineering, Brno University of Technology.

  17. Hydrogen assisted catalytic biomass pyrolysis. Effect of temperature and pressure

    DEFF Research Database (Denmark)

    Stummann, M.Z.; Høj, M.; Schandel, C. B.

    2018-01-01

    fraction of 17 and 22% daf, corresponding to an energy recovery of between 40 and 53% in the organic product. The yield of the non-condensable gases varied between a mass fraction of 24 and 32% daf and the char yield varied between 9.6 and 18% daf. The condensed organics contained a mass fraction of 42....... The effect of varying the temperature (365–511 °C) and hydrogen pressure (1.6–3.6 MPa) on the product yield and organic composition was studied. The mass balance closed by a mass fraction between 90 and 101% dry ash free basis (daf). The yield of the combined condensed organics and C4+ varied between a mass......–75% aromatics, based on GC × GC-FID chromatographic peak area, and the remainder was primarily naphthenes with minor amounts of paraffins. The condensed organics were essentially oxygen free (mass fraction below 0.001%) when both reactors were used. Bypassing the HDO reactor increased the oxygen concentration...

  18. Moderator temperature effects on reactivity of HEU core of MNSR

    International Nuclear Information System (INIS)

    Ahmad, Siraj-ul-Islam; Sahibzada, Tasveer Muhammad

    2012-01-01

    Highlights: ► The MNSR core was analyzed to see the cross section effects on moderator temperature coefficient of reactivity. ► WIMS-D code was used for cell calculations. ► The 3D diffusion theory code PRIDE was first validated using IAEA benchmark problem and then used for analysis of MNSR. ► The differences among results for various libraries were discussed. -- Abstract: In this article we report on analyses that were performed to investigate the influence of cross section differences among libraries released by various centers on reactivity of Miniature Neutron Source Reactors. The 3D model of the core was developed with WIMS-D and PRIDE codes and six cross section libraries were used including JENDL-3.2, JEF-2.2, JEFF-3.3, ENDF/B-VI and ENDF/B-VII, and IAEA library. It was observed that all the libraries predict the reactivity within 10%, with IAEA library giving minimum reactivity worth, and JEF-2.2 data library resulted in highest worth.

  19. Effect of elevated temperature on the compressive strength of ...

    African Journals Online (AJOL)

    Based on results of tests, partial replacement of cement with 10 % PSMS is recommended for use in concrete production and resistance to elevated temperature. The studies show that at this replacement, the concrete compressive strength is not adversely affected when the elevated temperature reaches 500°C. Keywords: ...

  20. The effect of high temperatures on concrete incorporating ultrafine ...

    African Journals Online (AJOL)

    In this work, several concrete formulations have been tested and multi-scale observation of high-temperature behavior of ordinary concrete (compressive strength of 48 MPa) and HPC (compressive strength 75 MPa) were adopted. On the scale of the material, the identification of trends with temperature data such as porosity ...

  1. Effects of temperature and salinity on resting metabolism in two ...

    African Journals Online (AJOL)

    This study investigates the resting metabolic rate (RMR; mg O2 g/h) of the resident rock pool fish Caffrogobius caffer and the transient sparid Diplodus sargus capensis at a range of salinities (5, 15, 25, 35 and 45 PSU) and temperatures (14, 20 and 28°C) using closed-vessel respirometry. Both species were temperature ...

  2. Effect of different storage temperatures on bacterial spoilage of ...

    African Journals Online (AJOL)

    This study determined the bacterial organisms associated with Oreochromis niloticus spoilage at two storage temperatures (6 and 20°C) and also assessed the ability of the individual bacterial isolates to cause spoilage at the two storage temperatures. Bacteriological analysis revealed the association of five bacteria ...

  3. Effects of low temperature and drought on the physiological and ...

    African Journals Online (AJOL)

    To find out how oil palm adapts to the environmental conditions, the dynamics of a series of important physiological components derived from the leaves of potted oil palm seedlings under drought stress (DS) (water with holding) and low temperature stress (LTS) (10°C) were studied. The results showed that low temperature ...

  4. Possible effects of regulating hydroponic water temperature on plant ...

    African Journals Online (AJOL)

    Water temperature can affect many physiological processes during plant growth and development. Temperatures below or above optimum levels may influence plant metabolic activities positively or negatively. This may include accumulation of different metabolites such as phenolic compounds, reactive oxygen species ...

  5. Effect of a background electric field on the Hagedorn temperature

    International Nuclear Information System (INIS)

    Ferrer, E.J.; Incera, V. de la; Fradkin, E.S.

    1990-07-01

    We compute the one-loop free energy of the open neutral string gas in a constant electromagnetic background. Starting from this result we show that the Hagedorn temperature of this hot string gas depends on the background electric field. The larger the electric field, the lower the Hagedorn temperature is. (author). 13 refs

  6. Effects of temperature, light, desiccation and cold storage on ...

    African Journals Online (AJOL)

    In the present experiments, germination characteristics, desiccation, and low temperature tolerance of seeds of Sophora tonkinensis was studied; a traditional Chinese medicine on the edge of extinction, were investigated for the first time in attempt to interpret their storage behaviour. The results indicate that the temperature ...

  7. Temperature effect on growth and larval duration of plaice

    NARCIS (Netherlands)

    Comerford, S.; Brophy, D.; Fox, C.J.; Taylor, N.; van der Veer, H.W.; Nash, R.D.M.; Geffen, A.J.

    2013-01-01

    Transport models for planktonic fish eggs and larvae often use temperature to drive growth because temperature data are readily available. This pragmatic approach can be criticised as too simplistic as it ignores additional factors, such as food availability and growth-rate-dependent mortality. We

  8. Laboratory Study of the Effect of Temperature Changes on Mixing ...

    African Journals Online (AJOL)

    This work is an investigation of the eect of temperature changes on the mixing and performance of ponds. The parameters tested for were: biochemical oxygen demand, dissolved oxygen, coliform, suspended solid, temperature and pH. Three metallic tanks were fed simultaneously by a plastic container under gravity.

  9. Effect of drying temperatures on the proximate composition and ...

    African Journals Online (AJOL)

    Results of the proximate composition showed that the nutritional qualities of the dried eggs were retained during drying thus the drying temperature did not affect the quality of eggs. The moisture contents of the dried whole egg, dried egg yolk and dried egg white at the different temperatures range from 6.25 -7.23%, ...

  10. The effects of a tranquilizer on body temperature.

    Science.gov (United States)

    1963-10-01

    Four young adult mongrel dogs were exposed twice untranquilized to each of three environmental temperatures: 4.4C, 23.9C, and 37.8C and exposed twice tranquilized with 2.2 mg/Kg propiopromazine hydrochloride. Rectal temperatures were monitored ...

  11. Effects of sintering time and temperature to the characteristics of FeCrAl powder compacts formed at elevated temperature

    Science.gov (United States)

    Rahman, M. M.; Rahman, H. Y.; Awang, M. A. A.; Sopyan, I.

    2018-01-01

    This paper presents the outcomes of an experimental investigation on the effect of sintering schedule, i.e., holding time and temperature to the final properties of FeCrAl powder compacts prepared through uniaxial die compaction process at above room temperature. The feedstock was prepared by mechanically mixing iron powder ASC 100.29 with chromium (22 wt%) and aluminium (11 wt%) for 30 min at room temperature. A cylindrical shape die was filled with the powder mass and heated for one hour for uniform heating of the die assembly together with the powder mass. Once the temperature reached to the setup temperature, i.e., 150°C, the powder mass was formed by applying an axial pressure of 425 MPa simultaneously from upward and downward directions. The as-pressed green compacts were then cooled to room temperature and subsequently sintered in argon gas fired furnace at a rate of 5°C/min for three different holding times, i.e., 30, 60, and 90 min at three different sintering temperatures, i.e., 800, 900, and 1000°C. The sintered samples were characterized for their density, electrical resistivity, bending strength, and microstructure. The results revealed that the sample sintered at 1000°C for 90 min achieved the better characteristics.

  12. The effects of digestion temperature and temperature shock on the biogas yields from the mesophilic anaerobic digestion of swine manure.

    Science.gov (United States)

    Chae, K J; Jang, Am; Yim, S K; Kim, In S

    2008-01-01

    In order to obtain basic design criteria for anaerobic digesters of swine manure, the effects of different digesting temperatures, temperature shocks and feed loads, on the biogas yields and methane content were evaluated. The digester temperatures were set at 25, 30 and 35 degrees C, with four feed loads of 5%, 10%, 20% and 40% (feed volume/digester volume). At a temperature of 30 degrees C, the methane yield was reduced by only 3% compared to 35 degrees C, while a 17.4% reduction was observed when the digestion was performed at 25 degrees C. Ultimate methane yields of 327, 389 and 403 mL CH(4)/g VS(added) were obtained at 25, 30 and 35 degrees C, respectively; with moderate feed loads from 5% to 20% (V/V). From the elemental analysis of swine manure, the theoretical biogas and methane yields at standard temperature and pressure were 1.12L biogas/g VS(destroyed) and 0.724 L CH(4)/g VS(destroyed), respectively. Also, the methane content increased with increasing digestion temperatures, but only to a small degree. Temperature shocks from 35 to 30 degrees C and again from 30 to 32 degrees C led to a decrease in the biogas production rate, but it rapidly resumed the value of the control reactor. In addition, no lasting damage was observed for the digestion performance, once it had recovered.

  13. Environmental effects of high temperature sodium of fatigue crack characteristics

    International Nuclear Information System (INIS)

    Abe, Hideaki; Takahashi, Kazuo; Ozawa, Kazumasa; Takahashi, Yukio

    2004-01-01

    In order to study fatigue crack growth characteristics in the components used in liquid sodium, fatigue tests were carried out at 550degC. This is near the system temperature used for sodium coolant in fast breeder reactors (FBRs). The factors influencing fatigue lifetime in sodium compared with that in air were investigated by observation of surface cracks in 316FR steel. Furthermore, the effects of sodium environment on fatigue were investigated based on examining the results of thermal striping tests, etc., obtained up to now. The results of the fatigue tests show that many micro cracks in the shearing direction were produced by the mid-lifetime, and micro cracks connected quickly after that. This is because an oxidation film was not formed, since sodium is of a reductive nature, and strain of the material surface tends to distribute equally. During crack progression there is no oxide formed on broken surfaces. Therefore re-combination between broken surfaces takes place, and crack progression rate falls. Furthermore, in non-propagating crack, the wedge effect by oxide between broken surfaces at the time of compression is small. Therefore, the crack closure angle is small, compression strain generated in the crack tip becomes large, and the crack cannot stop easily. As mentioned above, the main sodium influence on the fatigue characteristics are because of its reductive nature. In summary, in sodium environment, it is hard to form a crack and to get it to grow. Once started, however, it is hard to stop the crack in sodium compared with in the case of the air. (author)

  14. Effect of temperature on the population dynamics of Aedes aegypti

    Science.gov (United States)

    Yusoff, Nuraini; Tokachil, Mohd Najir

    2015-10-01

    Aedes aegypti is one of the main vectors in the transmission of dengue fever. Its abundance may cause the spread of the disease to be more intense. In the study of its biological life cycle, temperature was found to increase the development rate of each stage of this species and thus, accelerate the process of the development from egg to adult. In this paper, a Lefkovitch matrix model will be used to study the stage-structured population dynamics of Aedes aegypti. In constructing the transition matrix, temperature will be taken into account. As a case study, temperature recorded at the Subang Meteorological Station for year 2006 until 2010 will be used. Population dynamics of Aedes aegypti at maximum, average and minimum temperature for each year will be simulated and compared. It is expected that the higher the temperature, the faster the mosquito will breed. The result will be compared to the number of dengue fever incidences to see their relationship.

  15. An effective temperature compensation approach for ultrasonic hydrogen sensors

    Science.gov (United States)

    Tan, Xiaolong; Li, Min; Arsad, Norhana; Wen, Xiaoyan; Lu, Haifei

    2018-03-01

    Hydrogen is a kind of promising clean energy resource with a wide application prospect, which will, however, cause a serious security issue upon the leakage of hydrogen gas. The measurement of its concentration is of great significance. In a traditional approach of ultrasonic hydrogen sensing, a temperature drift of 0.1 °C results in a concentration error of about 250 ppm, which is intolerable for trace amount of gas sensing. In order to eliminate the influence brought by temperature drift, we propose a feasible approach named as linear compensation algorithm, which utilizes the linear relationship between the pulse count and temperature to compensate for the pulse count error (ΔN) caused by temperature drift. Experimental results demonstrate that our proposed approach is capable of improving the measurement accuracy and can easily detect sub-100 ppm of hydrogen concentration under variable temperature conditions.

  16. Effects of copper, hypoxia and acute temperature shifts on mitochondrial oxidation in rainbow trout (Oncorhynchus mykiss) acclimated to warm temperature

    International Nuclear Information System (INIS)

    Sappal, Ravinder; Fast, Mark; Stevens, Don; Kibenge, Fred; Siah, Ahmed; Kamunde, Collins

    2015-01-01

    Highlights: • Warm acclimation reduced the electron transport system (ETS) efficiency. • Warm acclimation altered the effects of acute temperature shift, hypoxia and Cu on ETS. • Warm acclimation increased thermal sensitivity of state 3 and reduced that of state 4. • Cu stimulated while hypoxia inhibited ETS respiratory activity. • Interactions of Cu and hypoxia on the ETS and plasma metabolites were antagonistic. - Abstract: Temperature fluctuations, hypoxia and metals pollution frequently occur simultaneously or sequentially in aquatic systems and their interactions may confound interpretation of their biological impacts. With a focus on energy homeostasis, the present study examined how warm acclimation influences the responses and interactions of acute temperature shift, hypoxia and copper (Cu) exposure in fish. Rainbow trout (Oncorhynchus mykiss) were acclimated to cold (11 °C; control) and warm (20 °C) temperature for 3 weeks followed by exposure to environmentally realistic levels of Cu and hypoxia for 24 h. Subsequently, mitochondrial electron transport system (ETS) respiratory activity supported by complexes I–IV (CI–IV), plasma metabolites and condition indices were measured. Warm acclimation reduced fish condition, induced aerobic metabolism and altered the responses of fish to acute temperature shift, hypoxia and Cu. Whereas warm acclimation decelerated the ETS and increased the sensitivity of maximal oxidation rates of the proximal (CI and II) complexes to acute temperature shift, it reduced the thermal sensitivity of state 4 (proton leak). Effects of Cu with and without hypoxia were variable depending on the acclimation status and functional index. Notably, Cu stimulated respiratory activity in the proximal ETS segments, while hypoxia was mostly inhibitory and minimized the stimulatory effect of Cu. The effects of Cu and hypoxia were modified by temperature and showed reciprocal antagonistic interaction on the ETS and plasma

  17. Effects of copper, hypoxia and acute temperature shifts on mitochondrial oxidation in rainbow trout (Oncorhynchus mykiss) acclimated to warm temperature

    Energy Technology Data Exchange (ETDEWEB)

    Sappal, Ravinder [Department of Pathology and Microbiology, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, Prince Edward Island C1A 4P3 (Canada); Department of Biomedical Sciences, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, Prince Edward Island C1A 4P3 (Canada); Fast, Mark [Department of Pathology and Microbiology, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, Prince Edward Island C1A 4P3 (Canada); Stevens, Don [Department of Biomedical Sciences, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, Prince Edward Island C1A 4P3 (Canada); Kibenge, Fred [Department of Pathology and Microbiology, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, Prince Edward Island C1A 4P3 (Canada); Siah, Ahmed [British Columbia Centre for Aquatic Health Sciences, 871A Island Highway, Campbell River, British Columbia V9W 2C2 (Canada); Kamunde, Collins, E-mail: ckamunde@upei.ca [Department of Biomedical Sciences, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, Prince Edward Island C1A 4P3 (Canada)

    2015-12-15

    Highlights: • Warm acclimation reduced the electron transport system (ETS) efficiency. • Warm acclimation altered the effects of acute temperature shift, hypoxia and Cu on ETS. • Warm acclimation increased thermal sensitivity of state 3 and reduced that of state 4. • Cu stimulated while hypoxia inhibited ETS respiratory activity. • Interactions of Cu and hypoxia on the ETS and plasma metabolites were antagonistic. - Abstract: Temperature fluctuations, hypoxia and metals pollution frequently occur simultaneously or sequentially in aquatic systems and their interactions may confound interpretation of their biological impacts. With a focus on energy homeostasis, the present study examined how warm acclimation influences the responses and interactions of acute temperature shift, hypoxia and copper (Cu) exposure in fish. Rainbow trout (Oncorhynchus mykiss) were acclimated to cold (11 °C; control) and warm (20 °C) temperature for 3 weeks followed by exposure to environmentally realistic levels of Cu and hypoxia for 24 h. Subsequently, mitochondrial electron transport system (ETS) respiratory activity supported by complexes I–IV (CI–IV), plasma metabolites and condition indices were measured. Warm acclimation reduced fish condition, induced aerobic metabolism and altered the responses of fish to acute temperature shift, hypoxia and Cu. Whereas warm acclimation decelerated the ETS and increased the sensitivity of maximal oxidation rates of the proximal (CI and II) complexes to acute temperature shift, it reduced the thermal sensitivity of state 4 (proton leak). Effects of Cu with and without hypoxia were variable depending on the acclimation status and functional index. Notably, Cu stimulated respiratory activity in the proximal ETS segments, while hypoxia was mostly inhibitory and minimized the stimulatory effect of Cu. The effects of Cu and hypoxia were modified by temperature and showed reciprocal antagonistic interaction on the ETS and plasma

  18. Temperature effects on early season cotton growth and development

    International Nuclear Information System (INIS)

    Reddy, K.R.; Hodges, H.F.; Reddy, V.R.

    1992-01-01

    Temperature is a primary environmental factor controlling growth and developmental rates of plants, yet little specific information is available regarding cotton (Gossypium hisutum L.) responses to temperature. Information covering a wide range of temperatures would be useful for predicting both developmental and growth rates in cotton. Therefore, an experiment was conducted in naturally lit, temperature- and CO 2 -controlled cabinets from soon after emergence until 56 d after emergence (DAE). The cabinets were maintained at 20/12, 25/17, 30/22, 35/27, and 40/32C day/night cycles. Plant heights, number of nodes, and leaf areas were determined weekly throughout the experiment, and dry weight measurements were obtained at three intervals. Mainstem elongation, leaf area growth, and biomass accumulation rates were very sensitive to temperature about 3 wk after emergence. Prior to that time, they were relatively insensitive to temperature. The temperature optimum for stem elongation, leaf area expansion, and biomass accumulation was 30/22 C. Developmental rates, as depicted by number of mainstem nodes produced, number of fruiting branches, and fruiting branch nodes, were not as sensitive to temperatures above 30/22 C as were growth rates. Four times as many fruiting branches were produced at 30/22 C as at 20/12 C; whereas more vegetative branches were produced at low temperatures. All flower buds abscised from plants grown at 40/32 C. Essentially, all bolls and squares were retained at 30/22 C while a 10% boll and square loss was observed at 35/27 C during the early reproductive period. Less time was required for this cultivar to produce squares at any temperature, suitable for growing cotton, than was suggested by previous experiments

  19. Effect of Temperature on Acoustic Evaluation of Standing trees and logs: Part 1-Laboratory investigation

    Science.gov (United States)

    Shan Gao; Xiping Wang; Lihai Wang; R. Bruce. Allison

    2012-01-01

    The goals of this study were to investigate the effect of environment temperature on acoustic velocity of standing trees and green logs and to develop workable models for compensating temperature differences as acoustic measurements are performed in different climates and seasons. The objective of Part 1 was to investigate interactive effects of temperature and...

  20. Effects of temperature and ionization density in medical luminescence dosimetry using Al2O3:C

    DEFF Research Database (Denmark)

    Edmund, Jens Morgenthaler

    2007-01-01

    temperature is kept constant, one can find an integration time which provides an OSL signal independent of stimulation temperature. Overall, the RL and OSL signals vary between -0.2 to 0.6% per C. Thermal effects were simulated with a band structure model and indicated that the temperature effects are caused...

  1. Effect of body fat and gender on body temperature distribution.

    Science.gov (United States)

    Neves, Eduardo Borba; Salamunes, Ana Carla Chierighini; de Oliveira, Rafael Melo; Stadnik, Adriana Maria Wan

    2017-12-01

    It is well known that body composition can influence peripheral heat loss and skin temperature. That the distribution of body fat is affected by gender is well known; however, there is little information on how body composition and gender influences the measure of skin temperature. This study evaluated skin temperature distribution according to body fat percentage (BF%) and gender. A sample of 94 apparently healthy volunteers (47 women and 47 men) was assessed with Dual-Energy X-Ray Absorptiometry (DXA) and infrared thermography (mean, maximum and minimum temperatures - T Mean , T Max and T Min ). The sample was divided into groups, according to health risk classification, based on BF%, as proposed by the American College of Sports Medicine: Average (n = 58), Elevated (n = 16) or High (n = 20). Women had lower T Mean in most regions of interest (ROI). In both genders, group High had lower temperature values than Average and Elevated in the trunk, upper and lower limbs. In men, palms and posterior hands had a tendency (p temperature along with increased BF%. T Mean , T Max and T Min of trunk, upper and lower limbs were negatively correlated with BF% and the fat percentage of each segment (upper limbs, lower limbs and trunk). The highest correlations found in women were between posterior trunk and BF% (rho = -0.564, p temperature than men, which was related with higher BF%. Facial temperature seems not to be influenced by body fat. With the future collection of data on the relationship between BF% and skin temperature while taking into account factors such as body morphology, gender, and ethnicity, we conclude that measurement of BF may be reliably estimated with the use of thermal imaging technology. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Temperature effects on geotechnical and hydraulic properties of bentonite hydrated with inorganic salt solutions

    DEFF Research Database (Denmark)

    Rashid, H. M. A.; Kawamoto, K.; Saito, T.

    2015-01-01

    © 2015, International Journal of GEOMATE. This study investigated the combined effect of temperature and single-species salt solutions on geotechnical properties (swell index and liquid limit) and hydraulic conductivity of bentonite applying different cation types, concentrations, and temperatures...

  3. Grasslands feeling the heat: The effects of elevated temperatures on a subtropical grassland

    Directory of Open Access Journals (Sweden)

    Rowan D. Buhrmann

    2016-12-01

    Conclusions: OTCs can simulate realistic increases of air temperature in subtropical grasslands. Graminoids and shrubs appear to benefit from elevated temperatures whilst forbs decrease in abundance, possibly through competition and/or direct physiological effects.

  4. Microhabitat effects of litter temperature and moisture on forest-floor invertebrate communities

    Science.gov (United States)

    Tim A. Christiansen; Sue A. Perry; William B. Perry

    1996-01-01

    Litter temperature and moisture may be altered due to changes in global climate. We investigated the effect of small changes in litter temperature and moisture on forest-floor communities in West Virginia.

  5. Temperature Dependence of the Moessbauer Effect on Prussian Blue Nanowires

    Energy Technology Data Exchange (ETDEWEB)

    Zhou Pingheng; Xue Desheng; Luo Haiqing; Shi Huigang [Lanzhou University, Key Lab for Magnetism and Magnetic Materials of MOE (China)

    2002-09-15

    Highly ordered Prussian blue nanowires with diameter of about 50 nm and length up to 4 {mu}m have been fabricated by an electrodepositing technology with two-step anodizing anodic aluminum oxide films. The Moessbauer spectra taken between 15 and 300 K indicate that the hyperfine parameters decrease as the temperature increases. The temperature dependence of the quadrupole splitting, the isomer shift and the spectra area are discussed. A decrease of Debye temperature for Prussian blue nanowires was found with respect to that of Prussian blue bulk.

  6. Temperature and Pressure Effects on Drilling Fluid Rheology and ECD in Very Deep Wells

    Energy Technology Data Exchange (ETDEWEB)

    Rommetveit, R.; Bjoerkvoll, K.S.

    1997-12-31

    The rheological properties of drilling fluids are usually approximated to be independent of pressure and temperature. In many cases this is a good approximation. However, for wells with small margins between pore and fracture pressure, careful evaluations and analysis of the effects of temperature and pressure on well bore hydraulics and kick probability are needed. In this publication the effects of pressure and temperature are discussed and described for typical HPHT (High Pressure High Temperature) wells. Laboratory measurements show that rheology is very pressure and temperature dependent. The practical implications of these observations are illustrated through a series of calculations with an advanced pressure and temperature simulator. 10 refs., 15 figs.

  7. Temperature Effects on Stiffness Moduli of Reservoir Sandstone from the Deep North Sea

    DEFF Research Database (Denmark)

    Orlander, Tobias; Andreassen, Katrine Alling; Fabricius, Ida Lykke

    We investigate effect of testing temperature on the dynamic frame stiffness of quartz-bearing North Sea sandstone from depths of 5 km. We show that at low stress levels, the rock frame stiffens with increasing temperature and we propose an explanation for the controlling mechanisms. While...... temperature. This is unfortunate and hence, we designed a testing program with the intension of separating and quantifying effects of temperature and stress, specifically for the sandstone material subject to this study....

  8. The effect of inertia, viscous damping, temperature and normal ...

    Indian Academy of Sciences (India)

    Nitish Sinha

    2018-04-16

    Apr 16, 2018 ... physical parameters such as inertia, viscous damping, temperature and normal stress on the chaotic ... However, the present study has shown the appearance of chaos for the specific .... Although chaos is a general man-.

  9. Effects of temperature on Chrysomya rufifacies (Diptera:Calliphoridae) development.

    Science.gov (United States)

    Byrd, J H; Butler, J F

    1997-05-01

    Growth curves were studied for the egg, larva, and pupa of Chrysomya rufifacies (Macquart) under mean cyclic temperatures of 15.6, 21.1, 26.7, and 35.0 degrees C and a constant temperature of 25.0 degrees C. Development from egg to adult under all regimes ranged from 190 to 598 h. A constant temperature of 25 degrees C produced a range of pupation times from 134 to 162 h, with adult emergence ranging from 237 to 289 h. The maximal preferential temperature of 35.1 degrees C was determined for maggots using a gradient system. Highly predictable developmental time, minimal larval length variation, and low cohort variation emphasize the utility of this species in entomological-based postmortem interval determinations. Therefore, C. rufifacies should be of primary forensic importance when recovered alone or in conjunction with other species of Calliphoridae.

  10. Effects of Temperature and Growing Seasons on Crop Water ...

    African Journals Online (AJOL)

    PROF HORSFALL

    The crop water requirement (CWR) depends on several factors including temperature and ...... infrastructure for collection, treatment and recycling of wastewater (MOEP, 2010 .... blue and grey water footprint of crops and derived crop products ...

  11. Possible effects of regulating hydroponic water temperature on plant ...

    African Journals Online (AJOL)

    Yomi

    2010-12-29

    Dec 29, 2010 ... temperature on plant growth, accumulation of nutrients and other metabolites ... Padda and Picha, 2008), a defensive mechanism em- ployed by plants ..... and flower development will vary depending on the growth stage of ...

  12. Temperature effects on vaccine induced immunity to viruses in fish

    DEFF Research Database (Denmark)

    Lorenzen, Niels; Lorenzen, Ellen; Rasmussen, Jesper Skou

    a problem in terms of inducing a protective immune response by vaccination in aquaculture, since it is often desirable to vaccinate fish during autumn, winter, or spring. In experimental vaccination trials with rainbow trout (Oncorhynchus mykiss) using a DNA-vaccine encoding the viral glycoprotein of viral...... haemorrhagic septicaemia virus (VHSV), non-specific as well as specific immune mechanisms seemed to be delayed at low temperature. At five weeks post vaccination fish kept at 5C had no detectable response of neutralising antibodies while two thirds of the fish kept at 15C had sero-converted. While protective...... immunity was still established at both temperatures, specificity analysis suggested that protection at the lower temperature was mainly due to non-specific innate antiviral mechanisms, which appeared to last longer at low temperature. This was presumably related to a prolonged persistence of the vaccine...

  13. Effects of sintering temperature on the density and porosity

    African Journals Online (AJOL)

    2013-03-01

    bonding) between the salt beads at all the temperatures in which sintering was performed. .... and the sintering of some covalent solids and low- stability ceramics. The entire sintering process is gen- erally considered to occur in ...

  14. The effect of temperature on one-dimensional nanometallic photonic ...

    Indian Academy of Sciences (India)

    ... 2016; revised 26 October 2016; accepted 16 December 2016; published online 7 April 2017 ... complex refractive index of silver is dependent on temperature and wavelength. ..... crystals: Physics and technology (Springer, Italia, 2008) p. 7.

  15. effect of elevated temperature on the compressive strength

    African Journals Online (AJOL)

    HOD

    reducing cost whilst maintaining structural integrity. [1–4].The solid ... density and surface appearance are affected by temperature .... Table 1: Physical properties of Sand, Granite, cement .... The relationship between weight loss and elevated.

  16. Effect of temperature on routine metabolism in Tilapia rendalli boulenger

    Energy Technology Data Exchange (ETDEWEB)

    Caulton, M.S.

    1977-12-01

    Using a continuous flow respirometer it was shown that young Tilapia rendalli had three distinct phases of oxygen consumption over the temperature range of 17 to 40/sup 0/C. In the first phase (17 to 28/sup 0/C) the metabolic energy demand followed the normal logarithmic increase with increasing temperature. Between 28 and 37/sup 0/C the increased oxygen uptake was suppressed and showed a relatively small increase with increasing temperature. This feature was believed to be a significant energy saving function important to the growth of these fish which feed in the warm eulitoral margins of lakes during the day. The final phase shows a return to the original logarithmic increase in oxygen consumption. These results were related to, and compared with, actual changes in biomass at various temperatures and the theoretical and actual biomass changes were found to compare favorably.

  17. Highly Effective Thermal Regenerator for Low Temperature Cryocoolers, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Future missions to investigate the structure and evolution of the universe require highly efficient, low-temperature cryocoolers for low-noise detector systems. We...

  18. Effect of temperature on moromi fermentation of soy sauce with ...

    African Journals Online (AJOL)

    PRECIOUS

    2010-02-01

    Feb 1, 2010 ... temperature of 45°C enhanced the aging of soy sauce, accompanying with lower contents of ethanol ... excretes protease, amylase and other enzymes. These .... produced through the microbial digestion of the starch.

  19. Effects of elevated ambient temperature on embryo implantation in rats

    African Journals Online (AJOL)

    Yomi

    2012-03-22

    Mar 22, 2012 ... ambient temperature leads to a delayed implantation and reduced number of implantation sites in. Sprague ... rates decrease after exposure to stress. One of the ..... implantation initiation time, support the previous findings.

  20. Effects of austenitizing temperature in quenched niobium steels

    International Nuclear Information System (INIS)

    Mello, F.B.C. de; Assuncao, F.C.R.

    1980-01-01

    Three steel compositions with varying Nb content were austenitized at different temperatures and quenched in cold water. Metallographic examination and hardness measurements provided a basis for explaining the hardening mechanism and the role of Nb on the process. (Author) [pt

  1. Development of Environment and Irradiation Effects of High Temperature Materials

    International Nuclear Information System (INIS)

    Ryu, Woo Seog; Kim, D. W.; Kim, S. H.

    2009-11-01

    Proposed materials, Mod.9Cr-1Mo steel (32 mm thickness) and 9Cr-1Mo-1W (100 mm thickness), for the reactor vessel were procured, and welded by the qualified welding technologies. Welding soundness was conformed by NDT, and mechanical testings were done along to weld depth. Two new irradiation capsules for use in the OR test hole of HANARO were designed and fabricated. specimens was irradiated in the OR5 test hole of HANARO with a 30MW thermal power at 390±10 .deg. C up to a fast neutron fluence of 4.4x10 19 (n/cm 2 ) (E>1.0 MeV). The dpa was evaluated to be 0.034∼0.07. Base metals and weldments of both Mod.9Cr-1Mo and 9Cr-1Mo-1W steels were tested tensile and impact properties in order to evaluate the irradiation hardening effects due to neutron irradiation. DBTT of base metal and weldment of Mod.9Cr-1Mo steel were -16 .deg. C and 1 .deg. C, respectively. After neutron irradiation, DBTT of weldment of Mod.9Cr-1Mo steel increased to 25 . deg. C. Alloy 617 and several nickel-base superalloys were studied to evaluate high temperature degradation mechanisms. Helium loop was developed to evaluate the oxidation behaviors of materials in the VHTR environments. In addition, creep behaviors in air and He environments were compared, and oxidation layers formed outer surfaces were measured as a function of applied stress and these results were investigated to the creep life

  2. Temperature Effects on Free Radicals in Gamma-sterilized Beef

    Science.gov (United States)

    Pramanik, S. I.; Jahan, M. S.

    1999-11-01

    Gamma irradiation has become the method of choice for sterilizing frozen meat and their products to reduce levels of food-borne pathogens and to extend shelf life. In this report we have employed ESR technique for detection of free radicals in sterilized and non-sterilized dry beef without bone. We have also determined the heating effects on free radicals at temperatures 176^°C and 250^°C. Meat samples were dried in a food dehydrator at 60^°C and were packaged in dry N_2. They were then sterilized by γ-irradiation (2.5 MRad), ground into powder, and placed in ESR sample tubes. Non-sterilized powder samples were used as control. While all powder samples, sterilized or not, produced a broad single line in the ESR spectra with (Δ H_pp ~ 9 G) and g = 2.013, the radical concentration in the sterilized samples increased by a factor of five. Heat treatment at 176^°C produced similar radicals. But, when samples were heated 250^°C different radical species were formed which are characterized by narrow width (Δ H_pp ~ 6 G) and lower g-value (g =2.010). In contrast with previous work, where free radicals in chicken bones were reduced by heating [1], we observed an increase in concentration. Results of structural analyses of the radicals will be presented. Ref.[1]: Radiat. Phys. Chem., 49, 477-481, 1997. Work supported by Grants from the University of Memphis

  3. EFFECT OF TEMPERATURE ON THE PROCESS OF BEER PRIMARY FERMENTATION

    OpenAIRE

    Miriam Solgajová; Helena Frančáková; Štefan Dráb; Žigmund Tóth

    2013-01-01

    Beer is a very popular and widespread drink worldwide. Beer may be defined as a foamy alcoholic drink aerated by carbon dioxide that is formed during fermentation. Sensorial and analytical character of beer is mainly formed during process of primary fermentation. Our work has monitored the influence of temperature of fermentation substrate on the process of primary fermentation during beer production. Obtained values of temperature and apparent extract out of four brews of 10% light hopped wo...

  4. Temperature and Solar Radiation Effects on Photovoltaic Panel Power

    OpenAIRE

    Karafil, Akif; Ozbay, Harun; Kesler, Metin

    2016-01-01

    Solar energy is converted to electrical energy directly by semi-conductors materials used in Photovoltaic (PV) panels. Although, there has been great advancements in semi-conductor material technology in recent years panel efficiency is very lower. There are many factors affecting the panel efficiency such as tilt angle, shading, dust, solar radiation level, temperature and wiring losses. Among these factors, solar radiation level and temperature are more prominent. The solar radiation level ...

  5. The effect of Soil Temperature on Electrodialytic Remediation

    DEFF Research Database (Denmark)

    Kristensen, Iben Vernegren

    1999-01-01

    The electrodialytic remediation of copper, zinc and lead contaminated kaolin was studied at three different temperatures (0-39 degrees centrigrate). It is shown that an increase in temperature increases the rate of remediation for all three metals. Copper and zinc shows similar rate constants......, while for lead, the rate constant obtained are significantly smaller. The increased remediation rate is presumed to be due mainly to the lowering of the viscosity....

  6. Temperature effects on copepod egg hatching: does acclimatization matter?

    DEFF Research Database (Denmark)

    Hansen, Benni Winding; Drillet, Guillaume; Kozmér, A.

    2010-01-01

    This report investigates female sizes, egg sizes and egg hatching rates in relation to temperature for the near-shore calanoid copepod Acartia tonsa cultured at 6, 9, 14 and 24°C for several generations to achieve acclimatization. Inverse size relationships of eggs and females were revealed...... with increasing temperature. Eggs produced at 6°C were 85 ± 4 µm in diameter, but decreased to 80 ± 3 µm at 24°C. Female cephalothorax length was 840 ± 52 and 692 ± 39 µm at 9 and 24°C, respectively. Parallel hatching experiments were performed between non-acclimatized and acclimatized cultures across a range...... of temperatures reflecting natural conditions in Danish waters. A greater fraction of eggs enter quiescence as temperature declines. Eggs were able to hatch at temperatures as low as 1.5°C. Final egg hatching success increased with temperature. Acclimatization of the copepods resulted in a lower maximum hatching...

  7. On the urban heat island effect dependence on temperature trends

    International Nuclear Information System (INIS)

    Camilloni, I.; Barros, V.

    1997-01-01

    For US, Argentine and Australian cities, yearly mean urban to rural temperature differences (ΔT u-r ) and rural temperatures (T r ) are negatively correlated in almost every case, suggesting that urban heat island intensity depends, among other parameters on the temperature itself. This negative correlation is related to the fact that interannual variability of temperature is generally lower in urban environments than in rural areas. This seems to hold true at low frequencies leading to opposite trends in the two variables. Hence, urban stations are prone to have lower trends in absolute value than rural ones. Therefore, regional data sets including records from urban locations, in addition to urban growth bias may have a second type of urban bias associated with temperature trends. A bulk estimate of this second urban bias trend for the contiguous United States during 1901-1984 indicates that it could be of the same order as the urban growth bias and of opposite sign. If these results could be extended to global data, it could be expected that the spurious influence of urban growth on global temperature trends during warming periods will be offset by the diminishing of the urban heat island intensity. 36 refs., 7 figs., 2 tabs

  8. Effect of Temperature on Tolbutamide Binding to Glycated Serum Albumin

    Directory of Open Access Journals (Sweden)

    Agnieszka Szkudlarek

    2017-03-01

    Full Text Available Glycation process occurs in protein and becomes more pronounced in diabetes when an increased amount of reducing sugar is present in bloodstream. Glycation of protein may cause conformational changes resulting in the alterations of its binding properties even though they occur at a distance from the binding sites. The changes in protein properties could be related to several pathological consequences such as diabetic and nondiabetic cardiovascular diseases, cataract, renal dysfunction and Alzheimer’s disease. The experiment was designed to test the impact of glycation process on sulfonylurea drug tolbutamide-albumin binding under physiological (T = 309 K and inflammatory (T = 311 K and T = 313 K states using fluorescence and UV-VIS spectroscopies. It was found in fluorescence analysis experiments that the modification of serum albumin in tryptophanyl and tyrosyl residues environment may affect the tolbutamide (TB binding to albumin in subdomain IIA and/or IIIA (Sudlow’s site I and/or II, and also in subdomains IB and IIB. We estimated the binding of tolbutamide to albumin described by a mixed nature of interaction (specific and nonspecific. The association constants Ka (L∙mol−1 for tolbutamide at its high affinity sites on non-glycated albumin were in the range of 1.98–7.88 × 104 L∙mol−1 (λex = 275 nm, 1.20–1.64 × 104 L∙mol−1 (λex = 295 nm and decreased to 1.24–0.42 × 104 L∙mol−1 at λex = 275 nm (T = 309 K and T = 311 K and increased to 2.79 × 104 L∙mol−1 at λex = 275 nm (T = 313 K and to 4.43–6.61 × 104 L∙mol−1 at λex = 295 nm due to the glycation process. Temperature dependence suggests the important role of van der Waals forces and hydrogen bonding in hydrophobic interactions between tolbutamide and both glycated and non-glycated albumin. We concluded that the changes in the environment of TB binding of albumin in subdomain IIA and/or IIIA as well as in subdomains IB and IIB influence on

  9. Does Temperature and UV Exposure History Modulate the Effects of Temperature and UV Stress on Symbiodinium Growth Rates?

    Science.gov (United States)

    Temperature and ultraviolet radiation (UV) alone or in combination are known to inhibit the growth of Symbiodinium isolates. This conclusion was drawn from a number of studies having widely different exposure scenarios. Here we have examined the effects of pre-exposure acclimat...

  10. Effects of Gloves, Temperature and Their Interaction on Finger, Hand, and Arm Blood Flow and Skin Temperature: A Pilot Study

    Science.gov (United States)

    Hallbech, M. Susan

    1996-01-01

    The objective of this study is to investigate the effects of cold only, commercially available gloves only, and the combination of gloves and cold on the blood flow and surface (skin) temperature of the medial and proximal phalanxes of digit 3, the metacarpal region of the hand, and the forearm.

  11. Effect of Temperature Variation on Modal Frequency of Reinforced Concrete Slab and Beam in Cold Regions

    Directory of Open Access Journals (Sweden)

    Hanbing Liu

    2016-01-01

    Full Text Available Changes of modal frequencies induced by temperature variation can be more obvious than those caused by structural damage, which will lead to the false damage identification results. Therefore, quantifying the temperature effect on modal frequencies is a critical step to eliminate its interference in damage detection. Due to the nonuniform and time-dependent characteristics of temperature distribution, it is insufficient to obtain the reliable relationships between temperatures and modal frequencies using temperatures in air or at surface. In this paper, correlations between measured temperatures (air temperature, surface temperature, mean temperature, etc. and modal frequencies for the slab and beam are comparatively analyzed. And the quantitative models are constructed considering nonuniform temperature distribution. Firstly, the reinforced concrete slab and beam were constructed and placed outside the laboratory to be monitored. Secondly, the correlation coefficients between modal frequencies and three kinds of temperatures are calculated, respectively. Thirdly, simple linear regression models between mean temperature and modal frequencies are established for the slab and beam. Finally, five temperature variables are selected to construct the multiple linear regression models. Prediction results reveal that the proposed multiple linear regression models possess favorable accuracy to quantify the temperature effect on modal frequencies considering nonuniform temperature distribution.

  12. Effect of operating microscope light on brain temperature during craniotomy.

    Science.gov (United States)

    Gayatri, Parthasarathi; Menon, Girish G; Suneel, Puthuvassery R

    2013-07-01

    Operating microscopes used during neurosurgery are fitted with xenon light. Burn injuries have been reported because of xenon microscope lighting as the intensity of xenon light is 300 W. We designed this study to find out if the light of operating microscope causes an increase in temperature of the brain tissue, which is exposed underneath. Twenty-one adult patients scheduled for elective craniotomies were enrolled. Distal esophageal temperature (T Eso), brain temperature under the microscope light (T Brain), and brain temperature under dura mater (T Dura) were measured continuously at 15-minute intervals during microscope use. The irrigation fluid temperature, room temperature, intensity of the microscope light, and the distance of the microscope from the brain surface were kept constant. The average age of the patients was 44±15 years (18 males and 3 females). The mean duration of microscope use was 140±39 minutes. There were no significant changes in T Brain and T Dura and T Eso over time. T Dura was significantly lower than T Brain both at time 0 and 60 minutes but not at 90 minutes. T Brain was significantly lower than T Eso both at time 0 and 60 minutes but not at 90 minutes. The T Dura remained significantly lower than T Eso at 0, 60, and 90 minutes. Our study shows that there is no significant rise in brain temperature under xenon microscope light up to 120 minutes duration, at intensity of 60% to 70%, from a distance of 20 to 25 cm from the brain surface.

  13. Effect of Temperature on Topological States of Circular DNA

    Science.gov (United States)

    Fan, Yang-Tao; Li, Xiu-Yan; Liu, Yan-Hui; Chen, Hu

    2017-07-01

    The different topological states of circular double-stranded DNA can be defined by their linking number. The equilibrium distribution of linking number can be obtained by circularizing a linear DNA into a circle by ligase. Based on the recent experimental results that the DNA bending rigidity and twist rigidity strongly depend on temperature, the reduced bending rigidity can be approximated by g=(3.19× {10}-19-T\\cdot 4.14× {10}-22) {erg}\\cdot {cm} over the temperature interval (5 ∼ 53) °C, and the temperature dependence of twist rigidity can be fitted by C(T)=(4588.89{exp} (-T/117.04)-251.33) nm. The temperature dependence of the linking number distribution of circular DNAs can be predicted by using Monte Carlo simulation. The variance of linking number distribution on temperature is in accordance with the previous experimental results. Compared with the temperature dependence of bending rigidity, the temperature dependence of twist rigidity causes a noticeable fluctuation in linking number distribution and mainly contribute towards the variance change of linking number distribution of circular DNA. The variance of the writhe number and twist number in the equation = + depends on the length of circular DNA. When the length of circular DNA is less than 230 nm, the variance of twist number is dominant over the variance of writhe number ( ), whereas for the condition that the length of the circular DNA is larger than 370 nm. Supported by the National Natural Science Foundation of China under Grant Nos. 11047022, 11204045, and 11464004, Guizhou Provincial Tracking Key Program of Social Development (SY20123089, SZ20113069), the General Financial Grant from the China Postdoctoral Science Foundation (2014M562341), the Research Foundation for Young University Teachers from Guizhou University (201311), and College Innovation Talent Team of Guizhou Province (2014)32

  14. Irradiation temperature effect on glutamine (spectrophotometric readout) dosimeter

    International Nuclear Information System (INIS)

    Gupta, B.L.; Narayan, G.R.; Nilekani, S.R.; Bhat, R.M.

    2001-01-01

    For the dose estimation using glutamine dosimeter, 20 mg L-glutamine powder is dissolved in 10 ml of a solution which contains 2x10 -3 mol dm -3 ferrous ammonium sulphate and 10 -4 mol dm -3 xylenol orange in aerated aqueous 0.033 mol dm -3 sulphuric acid (FX). The plot of absorbance at 549 nm against dose is non-linear, however, the plot of 1/absorbance vs. 1/dose is linear. The slope of this linear plot changes above an absorbance of 0.3 corresponding to a dose of about 15 kGy. The response of the dosimeter is independent of irradiation temperature in the temperature range of 23-30 deg. C within the uncertainty of dose measurement. Below 23 deg. C, the absorbance decreases by 1.23% per deg. sign C decrease in temperature while between 30 and 40 deg. C, the absorbance increases by 0.75% per deg. C increase in temperature. Above 40 deg. C, the absorbance increases by 0.2% per deg. C only. The absorbance is corrected for the irradiation temperature and the dose is read from a calibration graph at 25 deg. C. Either a linear or polynomial relation can be used for the dose calculation

  15. Effect of freezing temperature on the color of frozen salmon.

    Science.gov (United States)

    Ottestad, Silje; Enersen, Grethe; Wold, Jens Petter

    2011-09-01

    New freezing methods developed with the purpose of improved product quality after thawing can sometimes be difficult to get accepted in the market. The reason for this is the formation of ice crystals that can give the product a temporary color loss and make it less appealing. We have here used microscopy to study ice crystal size as a function of freezing temperature by investigating the voids in the cell tissue left by the ice crystals. We have also investigated how freezing temperature affects the color and the visible absorption spectra of frozen salmon. Freezing temperatures previously determined to be the best for quality after thawing (-40 to -60 °C) were found to cause a substantial loss in perceived color intensity during frozen state. This illustrated the conflict between optimal freezing temperatures with respect to quality after thawing against visual appearance during frozen state. Low freezing temperatures gave many small ice crystals, increased light scattering and an increased absorption level for all wavelengths in the visible region. Increased astaxanthin concentration on the other hand would give higher absorption at 490 nm. The results showed a clear potential of using visible interactance spectroscopy to differentiate between poor product coloration due to lack of pigmentation and temporary color loss due to light scattering by ice crystal. This type of measurements could be a useful tool in the development of new freezing methods and to monitor ice crystal growth during frozen storage. It could also potentially be used by the industry to prove good product quality. In this article we have shown that freezing food products at intermediate to low temperatures (-40 to -80 °C) can result in paler color during frozen state, which could affect consumer acceptance. We have also presented a spectroscopic method that can separate between poor product color and temporary color loss due to freezing. © 2011 Institute of Food Technologists®

  16. Effects of electrostatic discharge on three cryogenic temperature sensor models

    Energy Technology Data Exchange (ETDEWEB)

    Courts, S. Scott; Mott, Thomas B. [Lake Shore Cryotronics, 575 McCorkle Blvd., Westerville, OH 43082 (United States)

    2014-01-29

    Cryogenic temperature sensors are not usually thought of as electrostatic discharge (ESD) sensitive devices. However, the most common cryogenic thermometers in use today are thermally sensitive diodes or resistors - both electronic devices in their base form. As such, they are sensitive to ESD at some level above which either catastrophic or latent damage can occur. Instituting an ESD program for safe handling and installation of the sensor is costly and it is desirable to balance the risk of ESD damage against this cost. However, this risk cannot be evaluated without specific knowledge of the ESD vulnerability of the devices in question. This work examines three types of cryogenic temperature sensors for ESD sensitivity - silicon diodes, Cernox(trade mark, serif) resistors, and wire wound platinum resistors, all manufactured by Lake Shore Cryotronics, Inc. Testing was performed per TIA/EIA FOTP129 (Human Body Model). Damage was found to occur in the silicon diode sensors at discharge levels of 1,500 V. For Cernox(trade mark, serif) temperature sensors, damage was observed at 3,500 V. The platinum temperature sensors were not damaged by ESD exposure levels of 9,900 V. At the lower damage limit, both the silicon diode and the Cernox(trade mark, serif) temperature sensors showed relatively small calibration shifts of 1 to 3 K at room temperature. The diode sensors were stable with time and thermal cycling, but the long term stability of the Cernox(trade mark, serif) sensors was degraded. Catastrophic failure occurred at higher levels of ESD exposure.

  17. Effects of electrostatic discharge on three cryogenic temperature sensor models

    International Nuclear Information System (INIS)

    Courts, S. Scott; Mott, Thomas B.

    2014-01-01

    Cryogenic temperature sensors are not usually thought of as electrostatic discharge (ESD) sensitive devices. However, the most common cryogenic thermometers in use today are thermally sensitive diodes or resistors - both electronic devices in their base form. As such, they are sensitive to ESD at some level above which either catastrophic or latent damage can occur. Instituting an ESD program for safe handling and installation of the sensor is costly and it is desirable to balance the risk of ESD damage against this cost. However, this risk cannot be evaluated without specific knowledge of the ESD vulnerability of the devices in question. This work examines three types of cryogenic temperature sensors for ESD sensitivity - silicon diodes, Cernox(trade mark, serif) resistors, and wire wound platinum resistors, all manufactured by Lake Shore Cryotronics, Inc. Testing was performed per TIA/EIA FOTP129 (Human Body Model). Damage was found to occur in the silicon diode sensors at discharge levels of 1,500 V. For Cernox(trade mark, serif) temperature sensors, damage was observed at 3,500 V. The platinum temperature sensors were not damaged by ESD exposure levels of 9,900 V. At the lower damage limit, both the silicon diode and the Cernox(trade mark, serif) temperature sensors showed relatively small calibration shifts of 1 to 3 K at room temperature. The diode sensors were stable with time and thermal cycling, but the long term stability of the Cernox(trade mark, serif) sensors was degraded. Catastrophic failure occurred at higher levels of ESD exposure

  18. Temperature Effect on Power Drop of Different Photovoltaic Modules

    Directory of Open Access Journals (Sweden)

    Emad Talib Hahsim

    2016-05-01

    Full Text Available Solar module operating temperature is the second major factor affects the performance of solar photovoltaic panels after the amount of solar radiation. This paper presents a performance comparison of mono-crystalline Silicon (mc-Si, poly-crystalline Silicon (pc-Si, amorphous Silicon (a-Si and Cupper Indium Gallium di-selenide (CIGS photovoltaic technologies under Climate Conditions of Baghdad city. Temperature influence on the solar modules electric output parameters was investigated experimentally and their temperature coefficients was calculated. These temperature coefficients are important for all systems design and sizing. The experimental results revealed that the pc-Si module showed a decrease in open circuit voltage by -0.0912V/ºC while mc-Si and a-Si had nearly -0.07V/ºC and the CIGS has -0.0123V/ºC. The results showed a slightly increase in short circuit current with temperature increasing about 0.3mA/ºC ,4.4mA/ºC and 0.9mA/ºC for mc-Si , pc-Si and both a-Si and CIGS. The mc-Si had the largest drop in output power about -0.1353W/ºC while -0.0915, -0.0114 and -0.0276 W/ºC for pc-Si, a-Si and CIGS respectively. The amorphous silicon is the more suitable module for high operation temperature but it has the lowest conversion efficiency between the tested modules.

  19. New pressure and temperature effects on bacterial spores

    Science.gov (United States)

    Mathys, A.; Heinz, V.; Knorr, D.

    2008-07-01

    The mechanism of inactivation of bacterial spores by heat and pressure is still a matter of discussion. Obviously, the change of the dissociation equilibrium under pressure and temperature plays a dominant role in inactivation of microorganisms. Heat and pressure inactivation of Geobacillus. stearothermophilus spores at different initial pH-values in ACES and phosphate buffer confirmed this view. Thermal inactivation in ACES buffer at 122°C resulted in higher logarithmic reductions. Contrary, after pressure treatment at 900 MPa with 80°C phosphate buffer showed higher inactivation. These results indicated the different dissociation equilibrium shifts in buffer systems by heat and pressure. Due to preparation, storage and handling of highly concentrated spore suspensions the clumping and the formation of aggregates can hardly be avoided. Consequently, the impact of the agglomeration size distribution on the quantitative assessment of G. stearothermophilus spore inactivation was determined by using a three-fold dynamic optical backreflexion measurement. Two limiting cases have been discriminated in mathematical modelling: three dimensional, spherical packing for maximum spore count and two dimensional, circular packing for minimum spore count of a particular agglomerate. Thermal inactivation studies have been carried out in thin glass capillaries, where by using numerical simulations the non isothermal conditions were modelled and taken into account. It is shown that the shoulder formation often found in thermal spore inactivation can sufficiently be described by first-order inactivation kinetics when the agglomeration size is considered. In case of high pressure inactivation agglomerations could be strongly changed by high forces at compression and especially decompression phase. The physiological response of Bacillus licheniformis spores to high pressure was investigated using multiparameter flow cytometry. Spores were treated by high pressure at 150 MPa with 37

  20. New pressure and temperature effects on bacterial spores

    Energy Technology Data Exchange (ETDEWEB)

    Mathys, A; Knorr, D [Berlin University of Technology, Department of Food Biotechnology and Food Process Engineering, Koenigin-Luise-Str. 22, D-14195 Berlin (Germany); Heinz, V [German Institute of Food Technology, p. o. box 1165, D-49601, Quackenbrueck (Germany)], E-mail: alexander.mathys@tu-berlin.de

    2008-07-15

    The mechanism of inactivation of bacterial spores by heat and pressure is still a matter of discussion. Obviously, the change of the dissociation equilibrium under pressure and temperature plays a dominant role in inactivation of microorganisms. Heat and pressure inactivation of Geobacillus. stearothermophilus spores at different initial pH-values in ACES and phosphate buffer confirmed this view. Thermal inactivation in ACES buffer at 122 deg. C resulted in higher logarithmic reductions. Contrary, after pressure treatment at 900 MPa with 80 deg. C phosphate buffer showed higher inactivation. These results indicated the different dissociation equilibrium shifts in buffer systems by heat and pressure. Due to preparation, storage and handling of highly concentrated spore suspensions the clumping and the formation of aggregates can hardly be avoided. Consequently, the impact of the agglomeration size distribution on the quantitative assessment of G. stearothermophilus spore inactivation was determined by using a three-fold dynamic optical backreflexion measurement. Two limiting cases have been discriminated in mathematical modelling: three dimensional, spherical packing for maximum spore count and two dimensional, circular packing for minimum spore count of a particular agglomerate. Thermal inactivation studies have been carried out in thin glass capillaries, where by using numerical simulations the non isothermal conditions were modelled and taken into account. It is shown that the shoulder formation often found in thermal spore inactivation can sufficiently be described by first-order inactivation kinetics when the agglomeration size is considered. In case of high pressure inactivation agglomerations could be strongly changed by high forces at compression and especially decompression phase. The physiological response of Bacillus licheniformis spores to high pressure was investigated using multiparameter flow cytometry. Spores were treated by high pressure at 150 MPa

  1. New pressure and temperature effects on bacterial spores

    International Nuclear Information System (INIS)

    Mathys, A; Knorr, D; Heinz, V

    2008-01-01

    The mechanism of inactivation of bacterial spores by heat and pressure is still a matter of discussion. Obviously, the change of the dissociation equilibrium under pressure and temperature plays a dominant role in inactivation of microorganisms. Heat and pressure inactivation of Geobacillus. stearothermophilus spores at different initial pH-values in ACES and phosphate buffer confirmed this view. Thermal inactivation in ACES buffer at 122 deg. C resulted in higher logarithmic reductions. Contrary, after pressure treatment at 900 MPa with 80 deg. C phosphate buffer showed higher inactivation. These results indicated the different dissociation equilibrium shifts in buffer systems by heat and pressure. Due to preparation, storage and handling of highly concentrated spore suspensions the clumping and the formation of aggregates can hardly be avoided. Consequently, the impact of the agglomeration size distribution on the quantitative assessment of G. stearothermophilus spore inactivation was determined by using a three-fold dynamic optical backreflexion measurement. Two limiting cases have been discriminated in mathematical modelling: three dimensional, spherical packing for maximum spore count and two dimensional, circular packing for minimum spore count of a particular agglomerate. Thermal inactivation studies have been carried out in thin glass capillaries, where by using numerical simulations the non isothermal conditions were modelled and taken into account. It is shown that the shoulder formation often found in thermal spore inactivation can sufficiently be described by first-order inactivation kinetics when the agglomeration size is considered. In case of high pressure inactivation agglomerations could be strongly changed by high forces at compression and especially decompression phase. The physiological response of Bacillus licheniformis spores to high pressure was investigated using multiparameter flow cytometry. Spores were treated by high pressure at 150 MPa

  2. Temperature effect upon blood consumption in Triatoma infestans

    Directory of Open Access Journals (Sweden)

    Silvia Catalá

    1992-12-01

    Full Text Available Different blood consumption speed was observed in Triatoma infestans - nymphs and adults - exposed to 12 degrees C and 28 degrees C. Exposure to optimal temperature (28 degrees C allows the insects to consume blood at a rate of 9% per day. Significative relationship between blood amount present in the promesenteron and consumed blood was found at 28 degrees. Consumption of blood was drastically reduced at the lowest temperature. Accordingly, lack of ovaric development, oviposition and mating behaviour was observed in insects kept at 12 degrees C. Relationship between laboratory and field observations are discussed.

  3. Effect of Temperature on the Biotic Potential of Honeybee Microsporidia▿

    Science.gov (United States)

    Martín-Hernández, Raquel; Meana, Aránzazu; García-Palencia, Pilar; Marín, Pilar; Botías, Cristina; Garrido-Bailón, Encarna; Barrios, Laura; Higes, Mariano

    2009-01-01

    The biological cycle of Nosema spp. in honeybees depends on temperature. When expressed as total spore counts per day after infection, the biotic potentials of Nosema apis and N. ceranae at 33°C were similar, but a higher proportion of immature stages of N. ceranae than of N. apis were seen. At 25 and 37°C, the biotic potential of N. ceranae was higher than that of N. apis. The better adaptation of N. ceranae to complete its endogenous cycle at different temperatures clearly supports the observation of the different epidemiological patterns. PMID:19233948

  4. The effects of injected solution temperature on intravenous regional anaesthesia.

    Science.gov (United States)

    Paul, D L; Logan, M R; Wildsmith, J A

    1988-05-01

    Ten healthy volunteers received three standard Bier's blocks. Prilocaine 0.5%, 40 ml was injected at a solution temperature of 0 degrees C, 22 degrees C or 37 degrees C. Recordings were made of sensory block, motor block, intravenous pressure, limb temperature and pain on injection. There were no differences between the three treatments in the rate of development or in the quality of block but there was a significant difference in the comfort of injection. Cold solutions caused most, and warm solutions least discomfort.

  5. Effects of Dehydration on Fish Muscles at Chilled Temperature

    Science.gov (United States)

    Miki, Hidemasa; Seto, Fuminori; Nishimoto, Motomi; Nishimoto, Junichi

    Recently,new method of removing water from fish fillet at low temperature using dehydration sheet have been reported. The present study is concerned with the factors to affect the quality during dehydration of horse mackerel muscle at low temperature. The rate of dehydration at -3 °C was about two times faster than that at 0 °C. The rate of denaturation of fish muscle protein was kept less than about 10 % (ATPase activity) of the undenaturated initial values after removing free water content. Present results suggest the practical possibility of the dehydration at -3 °C for keeping quality of fish flesh.

  6. Electron temperature effects for an ion beam source

    International Nuclear Information System (INIS)

    Uramoto, Joshin.

    1979-05-01

    A hydrogen high temperature plasma up to 200 eV is produced by acceleration of electrons in a hot hollow cathode discharge and is used as an ion beam source. Then, two characteristics are observed: A rate of the atomic ion (H + ) number increases above 70%. A perveance of the ion beam increases above 30 times compared with that of a cold plasma, while a floating potential of an ion acceleration electrode approaches an ion acceleration potential (- 500 V) according as an increment of the electron temperature. Moreover, a neutralized ion beam can be produced by only the negative floating electrode without an external power supply. (author)

  7. Non-equilibrium effects in high temperature chemical reactions

    Science.gov (United States)

    Johnson, Richard E.

    1987-01-01

    Reaction rate data were collected for chemical reactions occurring at high temperatures during reentry of space vehicles. The principle of detailed balancing is used in modeling kinetics of chemical reactions at high temperatures. Although this principle does not hold for certain transient or incubation times in the initial phase of the reaction, it does seem to be valid for the rates of internal energy transitions that occur within molecules and atoms. That is, for every rate of transition within the internal energy states of atoms or molecules, there is an inverse rate that is related through an equilibrium expression involving the energy difference of the transition.

  8. Combustion Temperature Effect of Diesel Engine Convert to Compressed Natural Gas Engine

    OpenAIRE

    Semin; Abdul R. Ismail; Rosli A. Bakar

    2009-01-01

    Effect of combustion temperature in the engine cylinder of diesel engine convert to Compressed Natural Gas (CNG) engine was presents in this study. The objective of this study was to investigate the engine cylinder combustion temperature effect of diesel engine convert to CNG engine on variation engine speed. Problem statement: The hypothesis was that the lower performance of CNG engine was caused by the effect of lower in engine cylinder temperature. Are the CNG engine is lower cylinder temp...

  9. A low temperature cryostat with a refrigerator for studying electron-irradiation effects on solids, 2

    International Nuclear Information System (INIS)

    Oka, Takashi; Yoshida, Toshio; Shono, Yoshihiko

    1978-01-01

    A convenient cryostat with a small cryogenic refrigerator for studying electron-irradiation effects on solids is reported. The lowest temperature at the sample room is about 10 K or less. In a temperature region below 80 K, the sample temperature can be controlled within 0.05 K. (auth.)

  10. Effect of temperature on anaerobic treatment of black water in UASB-septic tank systems

    NARCIS (Netherlands)

    Luostarinen, S.; Sanders, W.T.M.; Kujawa-Roeleveld, K.; Zeeman, G.

    2007-01-01

    The effect of northern European seasonal temperature changes and low temperature on the performance of upflow anaerobic sludge blanket (UASB)-septic tanks treating black water was studied. Three UASB-septic tanks were monitored with different operational parameters and at different temperatures. The

  11. Temperature effects on solute diffusion and adsorption in differently compacted kaolin clay

    DEFF Research Database (Denmark)

    Mon, Ei Ei; Hamamoto, Shoichiro; Kawamoto, Ken

    2016-01-01

    Effects of soil temperature on the solute diffusion process in soils are important since subsurface temperature variation affects solute transport such as a fertilizer movement, leaching of salt, and pollutant movement to groundwater aquifers. However, the temperature dependency on the solute dif...

  12. Effect of Upper-Cycle Temperature on the Load-Biased, Strain-Temperature Response of NiTi

    Science.gov (United States)

    Padula, Santo, II; Noebe, Ronald; Bigelow, Glen; Qiu, Shipeng; Vaidyanathan, Raj; Gaydosh, Darrell; Garg, Anita

    2011-01-01

    Over the past decade, interest in shape memory alloy based actuators has increased as the primary benefits of these solid-state devices have become more apparent. However, much is still unknown about the characteristic behavior of these materials when used in actuator applications. Recently we have shown that the maximum temperature reached during thermal cycling under isobaric conditions could significantly affect the observed mechanical response of NiTi (55 wt% Ni), especially the amount of transformation strain available for actuation and thus work output. The investigation we report here extends that original work to ascertain whether further increases in the upper-cycle temperature would produce additional changes in the work output of the material, which has a stress-free austenite finish temperature of 113 C, and to determine the optimum cyclic conditions. Thus, isobaric, thermal-cycle experiments were conducted on the aforementioned alloy at various stresses from 50-300 MPa using upper-cycle temperatures of 165, 200, 230, 260, 290, 320 and 350 C. The data indicated that the amount of applied stress influenced the transformation strain, as would be expected. However, the maximum temperature reached during the thermal excursion also plays an equally significant role in determining the transformation strain, with the maximum transformation strain observed during thermal cycling to 290 C. In situ neutron diffraction at stress and temperature showed that the differences in transformation strain were mostly related to changes in martensite texture when cycling to different upper-cycle temperatures. Hence, understanding this effect is important to optimizing the operation of SMA-based actuators and could lead to new methods for processing and training shape memory alloys for optimal performance.

  13. Effect of temperature on the crack resistance of a molybdenum alloy with 30% tungsten

    International Nuclear Information System (INIS)

    Uskov, E.I.; Babak, A.V.; D'yachkov, A.P.; Platonov, V.A.

    1986-01-01

    Results are presented for a study of the effect of temperature on the crack resistance of molybdenum alloy with 30% tungsten (Mo - 30% W), and data are presented for the crack resistance of commercial-purity molybdenum and tungsten obtained by power metallurgy in the temperature range 20-1800 C. It was found that the nature of failure for Mo-30% W alloy depends on test temperature; in the temperature range 20 C-T /SUP d/ /SUB br/ (upper boundary for the temperature range of the ductile to brittle transition), failure is unstable in nature, and at temperatures exceeding this transition, it occurs by steady main crack development

  14. Modelling the effect of temperature on seed germination in some ...

    African Journals Online (AJOL)

    The prediction of germination percentage (GP) and germination speed (GS) of the seeds for some cucurbits (watermelon, melon, cucumber, summer squash, pumpkin and winter squash) was investigated by mathematical model based on temperature. The model, D = [a - (b x T) + (c x T2)] of Uzun et al. (2001), was adapted ...

  15. Temperature effects on peel spotting in "Sucrier banana" fruit

    NARCIS (Netherlands)

    Trakulnaleumsai, C.; Ketsa, S.; Doorn, van W.G.

    2006-01-01

    Banana fruit of the cultivar `Sucrier¿ (Musa acuminata, AA Group) develops peel spotting at a relatively early stage of development (when the peel is about as slightly more yellow than green). Holding ripening bananas at 15 and 18 °C instead of room temperature (26¿27 °C) only temporarily reduced

  16. Effects of temperature and water stresses on germination of some ...

    African Journals Online (AJOL)

    Therefore, we opted for the Chetoui variety that better meets the conditions of stresses induced by low temperatures and water deficit. This best performing variety must have, throughout their development cycle, been tolerant to environmental stresses; which allows us to obtain early tools for discriminative selection between ...

  17. barrel temperature emperature emperature effects on the ffects

    African Journals Online (AJOL)

    eobe

    Keywords: barrel temperature,plastic products, injection moulding machine , tensile strength, flexual strength. 1. INTRODUCTION. INTRODUCTION. INTRODUCTION. The utilization of process control and process monitoring are rarely fully implemented for the production of injection moulded products. This may be due to a ...

  18. The effect of grass transpiration on the air temperature

    Czech Academy of Sciences Publication Activity Database

    Šír, M.; Tesař, Miroslav; Lichner, Ľ.; Czachor, H.

    2014-01-01

    Roč. 69, č. 11 (2014), s. 1570-1576 ISSN 0006-3088 Institutional support: RVO:67985874 Keywords : air temperature oscillations * embolism * plant transpiration * soil water * tensiometric pressure * xylem tension Subject RIV: DA - Hydrology ; Limnology Impact factor: 0.827, year: 2014

  19. effects of temperature levels and concrete cover thickness

    African Journals Online (AJOL)

    HP USER

    With the knowledge of the temperature of the fire, thickness of concrete cover, residual strength of ... the structural behavior during fires by a careful inspection of the ... visual or physical damage is negligible; and Alonso[9] in the same vein said ...

  20. Effects of storage temperature and extension media on motility of ...

    African Journals Online (AJOL)

    ADEYEYE

    2016-07-26

    Jul 26, 2016 ... stored at room temperature and the other set was slowly cooled to 5°C and .... spermatozoa in buck semen stored in liquid form for 72h ... protein and a decrease in the ionic calcium and change in .... A review on goat sperm.

  1. Effect of electric field (at different temperatures) on germination of ...

    African Journals Online (AJOL)

    Chickpea (Cicer arietinum) seeds were exposed to electric field from zero to 1300 V for 15 min at three different temperatures (13, 16 and 19°C). It was found that the exposure of chickpea seeds to the electric field caused a change in water uptake capacity (and its coefficient) as compared to control. A new theoretical model ...

  2. Temperature fluctuation effect on microstructural evolution of vanadium

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, Hideo; Ochiai, Kenso; Yoshida, Naoaki [Kyushu Univ., Kasuga, Fukuoka (Japan). Research Inst. for Applied Mechanics

    1996-04-01

    To compare the damage structure of vanadium and it`s alloy by irradiation at a constant and fluctuating temperature, the microstructure of samples irradiated by heavy ion were observed by an electron microscope. Pure vanadium (99.9%) from China was used as samples. After preparing the samples for the electron microscope, they are covered with Zr and Ta film, vacuum sealed and annealed for 2h at 1323K. Then the samples were irradiated by 3 MeV Cu ion of 0.75-100 dpa at 473-873K. Temperature was changed from low to high (473K/673K, 473K/873K, 673K/873K). On the irradiation experiments at constant temperature, the density of dislocation decreased with increasing temperature, but, more than 773K, the density became very low and the needle precipitation grown to <100> and void were observed. On the irradiation experiment at 673K/873K, the density of number of precipitation and void were decreased. (S.Y.)

  3. Effects of reaction temperature on size and optical properties of ...

    Indian Academy of Sciences (India)

    Administrator

    influential factors in shape control of CdSe nanocrystals by changing the ratio of .... four different temperatures (200, 220, 240 and 280°C). During the whole .... J, Wu A M, Gambhir S S and Weiss S 2005 Science 307 538. Murray C B, Norris ...

  4. Effect of temperature, light intensity and growth regulators on ...

    African Journals Online (AJOL)

    Ansellia africana (Orchidaceae) is an important endangered medicinal plant species of South Africa which has been heavily exploited in recent years. Experiments were conducted in growth rooms at different temperatures (16, 26, 36°C) and in a nursery at different light intensities induced by shade cloth densities (200, 400, ...

  5. Modelling the effect of temperature on seed germination in some ...

    African Journals Online (AJOL)

    USER

    2010-03-01

    Mar 1, 2010 ... utilizes temperature for predicting seed germination and the model can be applied to ... seeds were sprinkled on round filter papers (Watman No. 1) in a 9 cm Petri dish and ..... A review of research on seedbed preparation for ...

  6. Effects of preparation temperature on the conductivity of polypyrrole ...

    Indian Academy of Sciences (India)

    Unknown

    2002-04-02

    Apr 2, 2002 ... polymer formed at low temperature has higher conductivity and is stronger than that ... it offers mass production at reasonable cost. ... its good intrinsic properties, polypyrrole appears promising for use in batteries, super ... actuators, electromagnetic interference shielding, anti-static coating and drug delivery.

  7. Environmental stressors during space flight: potential effects on body temperature

    Science.gov (United States)

    Jauchem, J. R.

    1988-01-01

    1. Organisms may be affected by many environmental factors during space flight, e.g., acceleration, weightlessness, decreased pressure, changes in oxygen tension, radiofrequency radiation and vibration. 2. Previous studies of change in body temperature--one response to these environmental factors--are reviewed. 3. Conditions leading to heat stress and hypothermia are discussed.

  8. Effects of drying temperature on viability of macaw palm ( Acrocomia ...

    African Journals Online (AJOL)

    In response to a growing interest in improving seedling production of oilseed species (like macaw palm), a fruit drying protocol for facilitating seed extraction was proposed. This enabled the production of macaw palm seedlings, but the temperature most suitable for seed extraction without losing its physiological quality is ...

  9. Effects of light and temperature on duckweed photosynthesis

    Energy Technology Data Exchange (ETDEWEB)

    Wedge, R M; Burris, J E

    1982-06-01

    Rates of photosynthesis of Lemna minor L. and Spirodela punctata, two aquatic angiosperms, were measured at different temperatures and light intensities. Photosynthesis was measured both as oxygen evolution and /sup 14/CO/sub 2/ fixation. At temperatures ranging from 15 to 35/sup 0/C, light saturation of photosynthetic O/sub 2/ evolution of Lemna occured from 300-600 ..mu..E m/sup -2/ s/sup -1/, while in Spirodela photosynthetic O/sub 2/ evolution was light saturated at 5600-1200 ..mu..E m/sup -2/ s/sup -1/. Photosynthetic O/sub 2/ evolution of both species was photoinhibited at light intensities greater than 1200 ..mu..E m/sup -2/ s/sup -1/. The optimal temperature for Lemna photosynthetic O/sub 2/ evolution was 30/sup 0/C, while the optimal temperatures for /sup 14/CO/sub 2/ fixation were from 20 to 30/sup 0/C. For Spirodela maximum photosynthetic O/sub 2/, evolution occurred at 35/sup 0/C, while maximum /sup 14/CO/sub 2/ fixation was at 30/sup 0/C.

  10. Effect of Brewing Time and Temperature on the release of ...

    African Journals Online (AJOL)

    Michael Horsfall

    Moringa oleifera blended leaves sample at brewing temperature and time of 29oC and 2mins respectively. ... most countries they are taken as tea to treat diabetics, obesity, fever ... human and highly toxic to insects, making it an ideal.

  11. Combined Effects of Temperature and Salinity on Larval ...

    African Journals Online (AJOL)

    It was found that P. catenata larvae develop optimally in near to seawater salinity at a temperature of around 25 ºC. These results support the assumption that newly-hatched larvae of this species are exported from the estuarine environment to the sea for development. Western Indian Ocean Journal of Marine Science ...

  12. Effect of working pressure and annealing temperature on ...

    Indian Academy of Sciences (India)

    roughness was found at higher temperatures as a result of a more heterogeneous growth and less tensions. Keywords. Barium strontium titanate; thin film; pulsed laser deposition; ferroelectric. 1. Introduction. Perovskite barium strontium titanate (BST) thin films are promising candidates for dynamic random access memory.

  13. Effects of agitation speed, temperature, carbon and nitrogen sources ...

    African Journals Online (AJOL)

    Lactococcus lactis is a Gram-positive bacterium widely used in the production of buttermilk and cheese. Recently, the bacterium becomes famous as the genetically modified organism can be used alive for the treatment of disease. In this study, different cultural conditions based on agitation speed and temperature on the ...

  14. Effect of strain rate and temperature at high strains on fatigue behavior of SAP alloys

    DEFF Research Database (Denmark)

    Blucher, J.T.; Knudsen, Per; Grant, N.J.

    1968-01-01

    Fatigue behavior of three SAP alloys of two nominal compositions (7 and 13% Al2O3) was studied in terms of strain rate and temperature at high strains; strain rate had no effect on life at 80 F, but had increasingly greater effect with increasing temperature above 500 F; life decreased with decre......Fatigue behavior of three SAP alloys of two nominal compositions (7 and 13% Al2O3) was studied in terms of strain rate and temperature at high strains; strain rate had no effect on life at 80 F, but had increasingly greater effect with increasing temperature above 500 F; life decreased...

  15. Soil surface temperatures reveal moderation of the urban heat island effect by trees and shrubs

    DEFF Research Database (Denmark)

    Edmondson, Jill L; Stott, Iain; Davies, Zoe G

    2016-01-01

    months increased by 0.6 °C over the 5 km from the city outskirts to the centre. Trees and shrubs in non-domestic greenspace reduced mean maximum daily soil surface temperatures in the summer by 5.7 °C compared to herbaceous vegetation, but tended to maintain slightly higher temperatures in winter. Trees...... in domestic gardens, which tend to be smaller, were less effective at reducing summer soil surface temperatures. Our findings reveal that the UHI effects soil temperatures at a city-wide scale, and that in their moderating urban soil surface temperature extremes, trees and shrubs may help to reduce...

  16. Low temperature modification of gamma-irradiation effect on peas. II.Low temperature effect on the radio-sensitivity and the chlorophyll mutations

    International Nuclear Information System (INIS)

    Najdenova, N.; Vasileva, M.

    1976-01-01

    Dry pea seeds of cv.Ramonskii 77 with 11-12% moisture were γ-irradiated by 60 Co in doses 5, 15, 20 and 30 krad. Low temperature (-78 deg C) was effected in the form of dry ice for a 24 h period prior to, at the time of and post irradiation. As control were used: (a) dry non-irradiated seeds, stored at room temperature; (b) non-irradiated seeds subjected to low temperature (-78 deg C) for a 24 h period. and (c) seeds irradiated by the named doses, stored at room temperature until the time of irradiation. Treated and control seeds were sown in the field. Germination, survival rate and sterility were recorded in M 1 , while in M 2 chlorophyll mutations were scored. Results obtained showed that low temperature modification effect on the various irradiation doses depended on the time of its application; low temperature (-78 deg C) treatment prior to seed irradiation with doses 15, 20 and 30 krad increased germination percentage, plant survival and yield components in M 1 . The post-irradiation treatment did not have a significant effect on gamma-rays; highest protection effect was obtained in case seeds were irradiated at low temperature and then received supplementary treatment at high temperature. In this way the damaging effect of radiation was reduced to a maximum degree; low temperature treatment prior to irradiation with doses of 15 and 20 krad or at the time of irradiation with doses of 15, 20 and 30 krad resulted in a considerably wider chlorophyll mutation spectrum. (author)

  17. Effects of incubation temperature on growth and performance of the veiled chameleon (Chamaeleo calyptratus).

    Science.gov (United States)

    Andrews, Robin M

    2008-10-01

    I evaluated the effect of incubation temperature on phenotypes of the veiled chameleon, Chamaeleo calyptratus. I chose this species for study because its large clutch size (30-40 eggs or more) allows replication within clutches both within and among experimental treatments. The major research objectives were (1) to assess the effect of constant low, moderate, and high temperatures on embryonic development, (2) to determine whether the best incubation temperature for embryonic development also produced the "best" hatchlings, and (3) to determine how a change in incubation temperature during mid-development would affect phenotype. To meet these objectives, I established five experimental temperature regimes and determined egg survival and incubation length and measured body size and shape, selected body temperatures, and locomotory performance of lizards at regular intervals from hatching to 90 d, or just before sexual maturity. Incubation temperature affected the length of incubation, egg survival, and body mass, but did not affect sprint speed or selected body temperature although selected body temperature affected growth in mass independently of treatment and clutch. Incubation at moderate temperatures provided the best conditions for both embryonic and post-hatching development. The highest incubation temperatures were disruptive to development; eggs had high mortality, developmental rate was low, and hatchlings grew slowly. Changes in temperature during incubation increased the among-clutch variance in incubation length relative to that of constant temperature treatments. Copyright 2008 Wiley-Liss, Inc.

  18. Temperature effect on X-ray photoelectron spectra of 3d transition metal ions

    International Nuclear Information System (INIS)

    Kochur, A.G.; Kozakov, A.T.; Yavna, V.A.; Daniel, Ph.

    2014-01-01

    Highlights: • 2p XPS of 3d metal ions are calculated in an isolated ion approximation. • 2p XPS of Ti, V, Cr, Mn, Fe ions are temperature dependent even at room temperature. • Temperature effect on 3p XPS is slight. • No temperature effect on 3s XPS is discovered. - Abstract: Temperature effect on 2p- 3s- and 3p X-ray photoelectron spectra (XPS) of various ions of Ti, V, Cr, Mn and Fe is studied theoretically within an isolated ion approximation. It is shown that the 2p XPS of those ions are temperature dependent even at room temperature due to a very slight energy splitting between the ground-state-term total-momentum J-components which can be thermally populated. Most significant temperature effect is expected in the 2p-spectra of Ti 2+ (3d 2 ), V 2+ (3d 3 ), Cr 2+ (3d 4 ), Mn 3+ (3d 4 ), and Mn 3+ (3d 4 ) ions. The temperature effect on 3p XPS is slight. No temperature effect on 3s XPS is expected

  19. The effect of temperature on the sensitivity of Daphnia magna to cyanobacteria is genus dependent.

    Science.gov (United States)

    Hochmuth, Jennifer D; De Schamphelaere, Karel A C

    2014-10-01

    In the present study, the authors investigated the effects of 6 different genera of cyanobacteria on multiple endpoints of Daphnia magna in a 21-d life table experiment conducted at 3 different temperatures (15 °C, 19 °C, and 23 °C). The specific aims were to test if the effect of temperature on Daphnia's sensitivity to cyanobacteria differed among different cyanobacteria and if the rank order from most to least harmful cyanobacteria to Daphnia reproduction changed or remained the same across the studied temperature range. Overall, the authors observed a decrease in harmful effects on reproduction with increasing temperature for Microcystis, Nodularia, and Aphanizomenon, and an increase in harmful effects with increasing temperature for Anabaena and Oscillatoria. No effect of temperature was observed on Daphnia sensitivity to Cylindrospermopsis. Harmful effects of Microcystis and Nodularia on reproduction appear to be mirrored by a decrease in length. On the other hand, harmful effects of Anabaena, Aphanizomenon, and Oscillatoria on reproduction were correlated with a decrease in intrinsic rate of natural increase, which was matched by a later onset of reproduction in exposures to Oscillatoria. In addition, the results suggest that the cyanobacteria rank order of harmfulness may change with temperature. Higher temperatures may increase the sensitivity of D. magna to the presence of some cyanobacteria (Anabaena and Oscillatoria) in their diet, whereas the harmful effects of others (Microcystis, Nodularia, and Aphanizomenon) may be reduced by higher temperatures. © 2014 SETAC.

  20. Effect of annealing temperature on the mechanical properties of Zircaloy-4 cladding

    International Nuclear Information System (INIS)

    Beauregard, R.J.; Clevinger, G.S.; Murty, K.L.

    1977-01-01

    The mechanical properties of Zircaloy cladding materials are sensitive to those fabrication variables which have an effect on the preferred crystallographic orientation or texture of the finished tube. The effect of one such variable, the final annealing temperature, on various mechanical properties is examined using tube reduced Zircaloy-4 fuel rod cladding annealed at temperatures from 905F to 1060F. This temperature range provides cladding with varying degrees of recrystallization including full recrystallization. The burst strength of the cladding at 650F decreased with the annealing temperature reaching a saturation value at approximately 1000F. The total circumferential elongation increased with the annealing temperature reaching a maximum at approximately 1000F and decreasing at higher temperatures. Hoop creep characteristics of Zircaloy cladding were studied as a function of the annealing temperature using closed-end internal pressurization tests at 750F and hoop stresses of 10, 15, 20 and 25 ksi. The effect of annealing temperature on the room temperature mechanical anisotropy parameters, R and P, was studied. The R-parameter was essentially independent of the annealing temperature while the P-parameter increased with annealing temperature. The mechanical anisotropy parameters were also studied as a function of the test temperature from ambient to approximately 800F using continuously monitored high precision extensometry. (Auth.)

  1. Effects of cold and hot temperature on dehydration: a mechanism of cardiovascular burden.

    Science.gov (United States)

    Lim, Youn-Hee; Park, Min-Seon; Kim, Yoonhee; Kim, Ho; Hong, Yun-Chul

    2015-08-01

    The association between temperature (cold or heat) and cardiovascular mortality has been well documented. However, few studies have investigated the underlying mechanism of the cold or heat effect. The main goal of this study was to examine the effect of temperature on dehydration markers and to explain the pathophysiological disturbances caused by changes of temperature. We investigated the relationship between outdoor temperature and dehydration markers (blood urea nitrogen (BUN)/creatinine ratio, urine specific gravity, plasma tonicity and haematocrit) in 43,549 adults from Seoul, South Korea, during 1995-2008. We used piece-wise linear regression to find the flexion point of apparent temperature and estimate the effects below or above the apparent temperature. Levels of dehydration markers decreased linearly with an increase in the apparent temperature until a point between 22 and 27 °C, which was regarded as the flexion point of apparent temperature, and then increased with apparent temperature. Because the associations between temperature and cardiovascular mortality are known to be U-shaped, our findings suggest that temperature-related changes in hydration status underlie the increased cardiovascular mortality and morbidity during high- or low-temperature conditions.

  2. Low temperature gamma-ray irradiation effects on polymer materials

    International Nuclear Information System (INIS)

    Kudoh, Hisaaki; Kasai, Noboru; Sasuga, Tsuneo; Seguchi, Tadao

    1995-01-01

    The gamma radiation induced degradation of glass fiber reinforced plastic (GFRP) and polymethylmethacrylate (PMMA) at 77K was examined by flexural test and gas analysis after irradiation and compared by the irradiation at room temperature. The decrease in flexural strength at break was much less at 77K than at RT. The evolution of CH 4 , CO and CO 2 was also depressed at 77K. The temperature dependence of the degradation closely relates to the local molecular motion of matrix resin during irradiation. Polytetrafluoroethylene (PTFE) was also studied by irradiation at RT, 77K and 4K in terms of tensile elongation and molecular weight. The degradation was much less at 77K and 4K than at RT, and the same between 77K and 4K. (author)

  3. Indoor ran don concentration. Temperature and wind effects

    International Nuclear Information System (INIS)

    Sesana, L.; Benigni, S.

    2000-01-01

    The present study analyses and discusses the behaviour of the indoor radon concentration in a research house. Hourly measurements were carried out in the basement of the house from November 1998 up to June 1999. In many sequences of days radon concentration in the room under analysis shows strong variation all day long with accumulation in the evening and overnight and decrease in the morning and in the afternoon. Measurements of wind velocity, indoor and outdoor temperatures and outdoor-indoor pressure difference were performed and their trend is compared with the observed radon concentration. The exhalation of radon from walls, floor and ceiling and the pressure difference driven exhalation from the soil are discussed, particularly the relation with the temperature differences. The air exchange rates between the house and the outdoor air are studied [it

  4. Effect of oxidation and annealing temperature on optical and ...

    Indian Academy of Sciences (India)

    Administrator

    Tin oxide thin films were deposited on glass substrate with 100 nm thickness of Sn, which was coated by magnetron sputtering followed by thermal oxidation at different temperatures. ... Annealing of the samples at 500–650 °C caused the transmittance and optical ..... (αhν)1/2 and (αhν)1/3 to determine the Eg. (b) They used.

  5. Effects of Temperature on Time Dependent Rheological Characteristics of Koumiss

    Directory of Open Access Journals (Sweden)

    Serdal Sabancı

    2016-04-01

    Full Text Available The rheological properties of koumiss were investigated at different temperatures (4, 10, and 20°C. Experimental shear stress–shear rate data were fitted to different rheological models. The consistency of koumiss was predicted by using the power-law model since it described the consistency of koumiss best with highest regression coefficient and lowest errors (root mean square error and chi-square. Koumiss exhibited shear thinning behavior (n

  6. Effects of temperature and hypoxic stress on the oxygen ...

    African Journals Online (AJOL)

    The specific oxygen consumption rate (VO2lMb) of Labeo capensis, the freshwater mudsucker, was determined for small and large fish at winter (8°C) and summer (23°C) temperatures. VO2lMb was also determined during hypoxic conditions of the experimental water. It was found that VO2lMb does not differ substantially ...

  7. Effect of operating temperature on LMFBR core performance

    International Nuclear Information System (INIS)

    Noyes, R.C.; Bergeron, R.J.; di Lauro, G.F.; Kulwich, M.R.; Stuteville, D.W.

    1977-01-01

    The purpose of the study is to provide an engineering evaluation of high and low temperature LMFBR core designs. The study was conducted by C-E supported by HEDL expertise in the areas of materials behavior, fuel performance and fabrication/fuel cycle cost. The evaluation is based primarily on designs and analyses prepared by AI, GE and WARD during Phase I of the PLBR studies

  8. Temperature effect on water absorption in an improved periwinkle ...

    African Journals Online (AJOL)

    Studies have been carried out on the water absorption of the improved periwinkle reinforced cement stabilized lateritic bricks. These bricks were produced at different cement to laterite to periwinkle ratio of 1:3:1, 2:3:1, 3:3:1, 3:2:1, 3:1:1, and fired at an elevated temperature of 10000C and 11500C, respectively. From the ...

  9. Temperature Effects Explain Continental Scale Distribution of Cyanobacterial Toxins

    OpenAIRE

    Mantzouki, Evanthia; Lürling, Miquel; Fastner, Jutta; de Senerpont Domis, Lisette; Wilk-Woźniak, Elżbieta; Koreivienė, Judita; Seelen, Laura; Teurlincx, Sven; Verstijnen, Yvon; Krztoń, Wojciech; Walusiak, Edward; Karosienė, Jūratė; Kasperovičienė, Jūratė; Savadova, Ksenija; Vitonytė, Irma

    2018-01-01

    Insight into how environmental change determines the production and distribution of cyanobacterial toxins is necessary for risk assessment. Management guidelines currently focus on hepatotoxins (microcystins). Increasing attention is given to other classes, such as neurotoxins (e.g., anatoxin-a) and cytotoxins (e.g., cylindrospermopsin) due to their potency. Most studies examine the relationship between individual toxin variants and environmental factors, such as nutrients, temperature and li...

  10. Temperature effects explain continental scale distribution of cyanobacterial toxins

    OpenAIRE

    Mantzouki, Evanthia; Lürling, Miquel; Fastner, Jutta; de Senerpont Domis, Lisette; Wilk-Woźniak, Elżbieta; Koreivienė, Judita; Seelen, Laura; Teurlincx, Sven; Verstijnen, Yvon; Krztoń, Wojciech; Walusiak, Edward; Karosienė, Jūratė; Kasperovičienė, Jūratė; Savadova, Ksenija; Vitonytė, Irma

    2018-01-01

    Insight into how environmental change determines the production and distribution of cyanobacterial toxins is necessary for risk assessment. Management guidelines currently focus on hepatotoxins (microcystins). Increasing attention is given to other classes, such as neurotoxins (e.g., anatoxin-a) and cytotoxins (e.g., cylindrospermopsin) due to their potency. Most studies examine the relationship between individual toxin variants and environmental factors, such as nutrients, temperature and li...

  11. Temperature hysteretic effect and its influence on colossal ...

    Indian Academy of Sciences (India)

    Record values of colossal magnetoresistance (CMR) have been achieved. The CMR value reaches nearly 99% in the temperature ranges of 90 K to 140 K and 90 K to 170 K for 20 kOe and 40 kOe magnetic fields in the cooling mode, respectively. The observed unusual behavior is attributed to the co-existence of La-rich ...

  12. THE EFFECT OF LINE-OF-SIGHT TEMPERATURE VARIATION AND NOISE ON DUST CONTINUUM OBSERVATIONS

    International Nuclear Information System (INIS)

    Shetty, Rahul; Kauffmann, Jens; Goodman, Alyssa A.; Ercolano, Barbara; Schnee, Scott

    2009-01-01

    We investigate the effect of line-of-sight temperature variations and noise on two commonly used methods to determine dust properties from dust-continuum observations of dense cores. One method employs a direct fit to a modified blackbody spectral energy distribution (SED); the other involves a comparison of flux ratios to an analytical prediction. Fitting fluxes near the SED peak produces inaccurate temperature and dust spectral index estimates due to the line-of-sight temperature (and density) variations. Longer wavelength fluxes in the Rayleigh-Jeans part of the spectrum (∼> 600 μm for typical cores) may more accurately recover the spectral index, but both methods are very sensitive to noise. The temperature estimate approaches the density-weighted temperature, or 'column temperature', of the source as short wavelength fluxes are excluded. An inverse temperature-spectral index correlation naturally results from SED fitting, due to the inaccurate isothermal assumption, as well as noise uncertainties. We show that above some 'threshold' temperature, the temperatures estimated through the flux ratio method can be highly inaccurate. In general, observations with widely separated wavelengths, and including shorter wavelengths, result in higher threshold temperatures; such observations thus allow for more accurate temperature estimates of sources with temperatures less than the threshold temperature. When only three fluxes are available, a constrained fit, where the spectral index is fixed, produces less scatter in the temperature estimate when compared to the estimate from the flux ratio method.

  13. Effect of storage temperature on Streptococcus mutans viability

    Directory of Open Access Journals (Sweden)

    Ana Lídia Soares COTA

    2018-04-01

    Full Text Available Abstract Introduction Proper storage conditions and maintenance of viable biological material plays an important role in microbiological research, allowing for the opportunity to conduct future studies. Objective To evaluate the viability of Streptococcus mutans strains that were previously grown and stored under different temperatures for approximately eight years. Material and method In this study, we evaluated 393 bacterial isolates that were stored in a freezer at -80°C (G1 and 200 isolates stored in a freezer at -20°C (G2. Aliquots of each sample were plated on blood agar and mitis-salivarius bacitracin sucrose agar-solidified medium. After incubating under microaerophilic conditions in an incubator at 37°C for 72 hours, the presence, morphology and purity of bacterial growth was observed. The data were analyzed by means of descriptive statistics. Result Microbial viability was observed in almost all samples (99.7% in G1, whereas all isolates stored at -20°C were considered inviable. Conclusion The viability of S. mutans is influenced by the storage temperature of the samples, and the strains remain viable when stored under ideal temperature conditions (-80°C, even when stored for a long period of time.

  14. Effects of Environmental Temperature on Capnodis tenebrionis Adult Phenology

    Directory of Open Access Journals (Sweden)

    Carmelo Peter Bonsignore

    2012-01-01

    Full Text Available The phenology of Capnodis tenebrionis adults was presented with reference to two different climate conditions. In a temperate moderate-warm climate, adult density showed two separate peaks during the year: one in early summer of the overwintering generation and one with beetles emerging in the late summer. In a warmer semiarid climate, the overwintering adults and the new generation overlapped during summer with a continuous increase of adult density. The difference in the average annual temperature between areas during the study period was almost 3∘C, and, in the warmer area, the new generation of C. tenebrionis emerged at least one month earlier. To make a prediction of adult presence, a model utilizing degree-days was developed from data collected over a five-year period. Models obtained from equations (Logistic 4-parameter, y(x=yo+a/(1+(x/xob of each year were developed to describe the relationship between degree-day accumulation (with a minimal threshold activity temperature of 14.21∘C calculated in the laboratory and the cumulative percentage of adult presence. According to the overall model, the 50% of overwintering beetles occurred at 726 degree-days (Biofix: 1st March and the emerging beetles occurred at 801 degree-days (Biofix: 1st July. The results show that a change in temperature is an important aspect that highlights the adaptability of this species.

  15. The effective temperatures and colours of G and K stars

    International Nuclear Information System (INIS)

    Bell, R.A.; Gustafsson, B.

    1989-01-01

    Temperature scales are found for G and K dwarf and giant stars, using new tables of synthetic infrared colours as well as the infrared flux ratio method. The temperatures of 95 individual stars are given. The colours are presented for grids of flux constant, line blanketed models. One grid has been published previously, as have some colours for the visible region of the spectrum. The models of this grid are in the range 4000 K eff < 6000 K, 0.75 < log g < 3.00, - 3.0 < [A/H] < 0.0. A grid of dwarf models, with the same temperature and abundance range but with 3.75 < log g < 4.5 is also used. The colours are computed from two series of overlapping synthetic spectra, which have been calculated with a resolution of 0.1 A between 3000 and 12 000 A and 1.0 A between 0.9 and 6.0 μm. (author)

  16. Temperature Dependence of Faraday Effect-Induced Bias Error in a Fiber Optic Gyroscope.

    Science.gov (United States)

    Li, Xuyou; Liu, Pan; Guang, Xingxing; Xu, Zhenlong; Guan, Lianwu; Li, Guangchun

    2017-09-07

    Improving the performance of interferometric fiber optic gyroscope (IFOG) in harsh environments, such as magnetic field and temperature field variation, is necessary for its practical applications. This paper presents an investigation of Faraday effect-induced bias error of IFOG under varying temperature. Jones matrix method is utilized to formulize the temperature dependence of Faraday effect-induced bias error. Theoretical results show that the Faraday effect-induced bias error changes with the temperature in the non-skeleton polarization maintaining (PM) fiber coil. This phenomenon is caused by the temperature dependence of linear birefringence and Verdet constant of PM fiber. Particularly, Faraday effect-induced bias errors of two polarizations always have opposite signs that can be compensated optically regardless of the changes of the temperature. Two experiments with a 1000 m non-skeleton PM fiber coil are performed, and the experimental results support these theoretical predictions. This study is promising for improving the bias stability of IFOG.

  17. Effects of rf power on electron density and temperature, neutral temperature, and Te fluctuations in an inductively coupled plasma

    International Nuclear Information System (INIS)

    Camparo, James; Fathi, Gilda

    2009-01-01

    Atomic clocks that fly on global-navigation satellites such as global positioning system (GPS) and Galileo employ light from low-temperature, inductively coupled plasmas (ICPs) for atomic signal generation and detection (i.e., alkali/noble-gas rf-discharge lamps). In this application, the performance of the atomic clock and the capabilities of the navigation system depend sensitively on the stability of the ICP's optical emission. In order to better understand the mechanisms that might lead to instability in these rf-discharge lamps, and hence the satellite atomic clocks, we studied the optical emission from a Rb/Xe ICP as a function of the rf power driving the plasma. Surprisingly, we found that the electron density in the plasma was essentially independent of increases in rf power above its nominal value (i.e., 'rf-power gain') and that the electron temperature was only a slowly varying function of rf-power gain. The primary effect of rf power was to increase the temperature of the neutrals in the plasma, which was manifested by an increase in Rb vapor density. Interestingly, we also found evidence for electron temperature fluctuations (i.e., fluctuations in the plasma's high-energy electron content). The variance of these fluctuations scaled inversely with the plasma's mean electron temperature and was consistent with a simple model that assumed that the total electron density in the discharge was independent of rf power. Taken as a whole, our results indicate that the electrons in alkali/noble-gas ICPs are little affected by slight changes in rf power and that the primary effect of such changes is to heat the plasma's neutral species.

  18. The surface temperature effect on the dissociative sticking of N2 on Fe(111)

    DEFF Research Database (Denmark)

    Henriksen, Niels Engholm; Hansen, Flemming Yssing; Billing, Gert Due

    1995-01-01

    We present the first realistic calculation of the surface temperature effect on the dissociative sticking probability of molecular nitrogen on Fe(111). Extensive quantum dynamical calculations show that, depending on the impact point in the unit cell, the sticking probabilities can increase as well...... as decrease as a function of the surface temperature. The magnitude of the temperature effect on randomly chosen impact points is comparable with the experimental observation. Since only a small fraction of the impacts give a significant contribution to the sticking and the alternating temperature effect...

  19. Effect of temperature upon the fatigue-crack propagation behavior of Inconel 625

    International Nuclear Information System (INIS)

    James, L.A.

    1977-03-01

    The techniques of linear-elastic fracture mechanics were employed to characterize the effect of temperature upon the fatigue-crack propagation behavior of mill-annealed Inconel 625 in an air environment over the range 75 0 - 1200 0 F (24 0 - 649 0 C). In general, fatigue-crack growth rates increased with increasing test temperature. Two different specimen sizes were employed at each test temperature, and no effects of specimen size upon crack growth were noted

  20. Effect of temperature on the electro-oxidation of ethanol on platinum

    OpenAIRE

    Camargo, Ana Paula M.; Previdello, Bruno A. F.; Varela, Hamilton; Gonzalez, Ernesto R.

    2010-01-01

    We present in this work an experimental investigation of the effect of temperature (from 25 to 180 ºC) in the electro-oxidation of ethanol on platinum in two different phosphoric acid concentrations. We observed that the onset potential for ethanol electro-oxidation shifts to lower values and the reaction rates increase as temperature is increased for both electrolytes. The results were rationalized in terms of the effect of temperature on the adsorption of reaction intermediates, poisons, an...

  1. Effective neutron temperature measurements in well moderated reactor by the reactivity coefficient method

    International Nuclear Information System (INIS)

    Raisic, N.; Klinc, T.

    1968-11-01

    The ratio of the reactivity changes of a nuclear reactor produced by successive introduction of two different neutron absorbers in the reactor core, has been measured and information on effective neutron temperature at a particular point obtained. Boron was used as a l/v absorber and cadmium as an absorber sensiti ve to neutron temperature. Effective neutron temperature distribution has been deduced by moving absorbers across the reactor core and observing the corresponding reactivity changes. (author)

  2. Interactive effect of elevated CO2 and temperature on coral physiology

    Science.gov (United States)

    Grottoli, A. G.; Cai, W.; Warner, M.; Melman, T.; Schoepf, V.; Baumann, J.; Matsui, Y.; Pettay, D. T.; Hoadley, K.; Xu, H.; Wang, Y.; Li, Q.; Hu, X.

    2011-12-01

    Increases in ocean acidification and temperature threaten coral reefs globally. However, the interactive effect of both lower pH and higher temperature on coral physiology and growth are poorly understood. Here, we present preliminary findings from a replicated controlled experiment where four species of corals (Acorpora millepora, Pocillopora damicornis, Montipora monasteriata, Turbinaria reniformis) were reared under the following six treatments for three weeks: 1) 400ppm CO2 and ambient temperature, 2) 400ppm CO2 and elevated temperature, 3) 650ppm CO2 and ambient temperature, 4) 650ppm CO2 and elevated temperature, 5) 800ppm CO2 and ambient temperature, 6) 800ppm CO2 and elevated temperature. Initial findings of photophysiological health (Fv/Fm), calcification rates (as measured by both buoyant weight and the total alkalinity methods), and energy reserves will be presented.

  3. Irradiation effect of the insulating materials for fusion superconducting magnets at cryogenic temperature

    Science.gov (United States)

    Kobayashi, Koji; Akiyama, Yoko; Nishijima, Shigehiro

    2017-09-01

    In ITER, superconducting magnets should be used in such severe environment as high fluence of fast neutron, cryogenic temperature and large electromagnetic forces. Insulating material is one of the most sensitive component to radiation. So radiation resistance on mechanical properties at cryogenic temperature are required for insulating material. The purpose of this study is to evaluate irradiation effect of insulating material at cryogenic temperature by gamma-ray irradiation. Firstly, glass fiber reinforced plastic (GFRP) and hybrid composite were prepared. After irradiation at room temperature (RT) or liquid nitrogen temperature (LNT, 77 K), interlaminar shear strength (ILSS) and glass-transition temperature (Tg) measurement were conducted. It was shown that insulating materials irradiated at room temperature were much degraded than those at cryogenic temperature.

  4. Effect of ambient temperature on emergency department visits in Shanghai, China: a time series study.

    Science.gov (United States)

    Zhang, Yue; Yan, Chenyang; Kan, Haidong; Cao, Junshan; Peng, Li; Xu, Jianming; Wang, Weibing

    2014-11-25

    Many studies have examined the association between ambient temperature and mortality. However, less evidence is available on the temperature effects on gender- and age-specific emergency department visits, especially in developing countries. In this study, we examined the short-term effects of daily ambient temperature on emergency department visits (ED visits) in Shanghai. Daily ED visits and daily ambient temperatures between January 2006 and December 2011 were analyzed. After controlling for secular and seasonal trends, weather, air pollution and other confounding factors, a Poisson generalized additive model (GAM) was used to examine the associations between ambient temperature and gender- and age-specific ED visits. A moving average lag model was used to evaluate the lag effects of temperature on ED visits. Low temperature was associated with an overall 2.76% (95% confidence interval (CI): 1.73 to 3.80) increase in ED visits per 1°C decrease in temperature at Lag1 day, 2.03% (95% CI: 1.04 to 3.03) and 2.45% (95% CI: 1.40 to 3.52) for males and females. High temperature resulted in an overall 1.78% (95% CI: 1.05 to 2.51) increase in ED visits per 1°C increase in temperature on the same day, 1.81% (95% CI: 1.08 to 2.54) among males and 1.75% (95% CI: 1.03 to 2.49) among females. The cold effect appeared to be more acute among younger people aged effects were consistent on individuals aged ≥65 years. In contrast, the effects of high temperature were relatively consistent over all age groups. These findings suggest a significant association between ambient temperature and ED visits in Shanghai. Both cold and hot temperatures increased the relative risk of ED visits. This knowledge has the potential to advance prevention efforts targeting weather-sensitive conditions.

  5. Effect of substrate temperature and post annealing temperature on ZnO:Zn PLD thin film properties

    Science.gov (United States)

    Hasabeldaim, E.; Ntwaeaborwa, O. M.; Kroon, R. E.; Coetsee, E.; Swart, H. C.

    2017-12-01

    The pulsed laser deposition (PLD) substrate temperature and post-annealing temperature are effective methods to control the film optical and structural properties. The structure, morphology and optical properties of the deposited and post-annealed PLD ZnO:Zn films were studied. The films were deposited at different substrate temperatures of 50 °C, 200 °C and 400 °C. The films deposited at the substrate temperature of 50 °C and 200 °C were post-annealed in air at 400 °C and 600 °C for two hours. The films all had a highly preferential orientation with the hexagonal c-axis perpendicular to the substrate surface. The stress was found to be compressive stress with values -3.289 GPa, -4.864 GPa and -4.425 GPa for the film deposited at 50 °C, 200 °C and 400 °C, respectively. After post-annealing treatments, the stress of the films was almost completely released and stress-free films were obtained. The crystallite sizes were 19 nm, 25 nm and 39 nm, while the average particles sizes were 95 nm, 85 nm and 129 nm for the film deposited at 50 °C, 200 °C and 400 °C respectively. The crystallite sizes and particles sizes seemed to increase with the increase in the substrate temperature. Contrary to this, the change in crystallite sizes were inversely proportional to the particles size when increasing the post-annealing temperatures. Deconvoluted X-ray photoelectron spectroscopy peaks of the O1s binding energy region revealed that the films deposited at different substrate temperatures contained oxygen-related defects. Photoluminescence studies revealed that the films all emitted ultra-violet emission around 379 nm. The film deposited at 50 °C emitted a broad green emission centered at ∼524 nm. By increasing the substrate temperature up to 200 °C and 400 °C a new orange emission around 621 nm and 634 nm as well as a weak emission around 416 nm and 500 nm were observed, respectively. After post-annealing treatments, new bands over the visible region (blue, green

  6. Ageing and temperature effect on the fatigue performance of bituminous mixtures

    Directory of Open Access Journals (Sweden)

    T. López-Montero

    2017-06-01

    Full Text Available The ageing of asphalt mixes, together with their exposure to low temperatures, causes a progressive increase of cracking. In this paper, the effect of ageing and temperature on the fatigue of asphalt concretes made with two types of binders, conventional (50/70 and polymer modified bitumen (PMB, is studied. For this purpose, specimens previously subjected to an accelerated laboratory ageing process were tested by a strain sweep test at different temperatures (-5ºC, 5ºC and 20°C. Results were compared with the obtained from the unaged specimens showing the relative importance of ageing, temperature and type of bitumen on the parameters that determine the fatigue life of the mixture. The mixtures behaviour becomes more brittle with ageing and the decrease of temperature. However, ageing hardly has an effect on fatigue at lower temperatures. In general, mixtures made with polymer modified bitumen have a better fatigue performance to ageing and temperature.

  7. The effect of air velocity on heat stress at increased air temperature

    DEFF Research Database (Denmark)

    Bjerg, B.; Wang, Xiaoshuai; Zhang, Guoqiang

    Increased air velocity is a frequently used method to reduce heat stress of farm animals housed in warm conditions. The main reason why the method works is that higher air velocity increases the convective heat release from the animals. Convective heat release from the animals is strongly related...... to the temperature difference between the surfaces of animals and the surrounding air, and this temperature difference declines when the air temperature approaches the animal body temperature. Consequently it can it by expected that the effect of air velocity decreases at increased air temperature. The literature...... on farm animals in warm conditions includes several thermal indices which incorporate the effect of air velocities. But, surprisingly none of them predicts a decreased influence of air velocity when the air temperature approaches the animal body temperature. This study reviewed published investigations...

  8. Effects of temperature and salinity on the development of the amphipod crustacean Eogammarus sinensis

    Science.gov (United States)

    Xue, Suyan; Fang, Jianguang; Zhang, Jihong; Jiang, Zengjie; Mao, Yuze; Zhao, Fazhen

    2013-09-01

    The amphipod crustacean Eogammarus sinensis has useful features that make it suitable for use in the aquaculture of fish and large decapod crustaceans. In this study, we investigated the effects of temperature and salinity on the development, fecundity, survival, and growth rate of E. sinensis. The results show that temperature significantly affected E. sinensis development, but salinity. As temperature increased, the duration of E. sinensis embryonic development decreased. Fecundity was affected significantly by temperature and the combination of temperature and salinity, but by salinity alone. In addition, high temperatures accelerated E. sinensis juvenile growth rates, whereas high salinity reduced it. Therefore, our data suggest that E. sinensis tolerates a wide range of salinities and that temperature has more significant effects than salinity on the embryonic development, fecundity, and growth of E. sinensis. Our results shall be useful for mass production of this species for use in aquaculture.

  9. Testing the effects of temperature and humidity on printed passive UHF RFID tags on paper substrate

    Science.gov (United States)

    Linnea Merilampi, Sari; Virkki, Johanna; Ukkonen, Leena; Sydänheimo, Lauri

    2014-05-01

    This article is an interesting substrate material for environmental-friendly printable electronics. In this study, screen-printed RFID tags on paper substrate are examined. Their reliability was tested with low temperature, high temperature, slow temperature cycling, high temperature and high humidity and water dipping test. Environmental stresses affect the tag antenna impedance, losses and radiation characteristics due to their impact on the ink film and paper substrate. Low temperature, temperature cycling and high humidity did not have a radical effect on the measured parameters: threshold power, backscattered signal power or read range of the tags. However, the frequency response and the losses of the tags were slightly affected. Exposure to high temperature was found to even improve the tag performance due to the positive effect of high temperature on the ink film. The combined high humidity and high temperature had the most severe effect on the tag performance. The threshold power increased, backscattered power decreased and the read range was shortened. On the whole, the results showed that field use of these tags in high, low and changing temperature conditions and high humidity conditions is possible. Use of these tags in combined high-humidity and high-temperature conditions should be carefully considered.

  10. Effects of wall temperature on skin-friction measurements by oil-film interferometry

    International Nuclear Information System (INIS)

    Bottini, H; Kurita, M; Iijima, H; Fukagata, K

    2015-01-01

    Wind-tunnel skin-friction measurements with thin-oil-film interferometry have been taken on an aluminum sample to investigate the effects of wall temperature on the accuracy of the technique. The sample has been flush-mounted onto a flat plate with an electric heater at its bottom and mirror-smooth temperature-sensitive paint sprayed on its top. The heater has varied the sample temperature from ambient to 328 K, and the paint has permitted wall temperature measurements on the same area of the skin-friction measurements and during the same test. The measured wall temperatures have been used to calculate the correct oil viscosities, and these viscosities and the constant nominal viscosity at 298 K have been used to calculate two different sets of skin-friction coefficients. These sets have been compared to each other and with theoretical values. This comparison shows that the effects of wall temperature on the accuracy of skin-friction measurements are sensible, and more so as wall temperature differs from 298 K. Nonetheless, they are effectively neutralized by the use of wall temperature measurements in combination with the correct oil viscosity–temperature law. In this regard, the special temperature-sensitive paint developed for this study shows advantages with respect to more traditional wall temperature measurement techniques. (paper)

  11. Ontogeny of decapod crustacean hemocyanin: effects of temperature and nutrition.

    Science.gov (United States)

    Terwilliger, N; Dumler, K

    2001-03-01

    Hemocyanin is present throughout the decapod crustacean's life, usually as one-hexamer and two-hexamer oligomers. Hemocyanins of some decapod crustaceans undergo changes in subunit composition and oxygen affinity during development. Maternal hemocyanin is taken up from the hemolymph via endocytosis by the oocyte. Embryo hemocyanin differs in subunit composition from hemocyanin of oocyte and adult crab and may represent the onset of hemocyanin synthesis. Complex changes in expression of hemocyanin subunits occur through megalopa and early juvenile stages of the crab Cancer magister, culminating in the pattern of adult hemocyanin. The influences of food availability and temperature on development, growth and hemocyanin ontogeny in early juvenile C. magister have been studied. Crabs were raised in warm or cold sea water and fed high or low levels of food for 6 months. While intermolt period was shorter in crabs fed high food levels, especially those raised in warm water, crabs reared in cold water with high food levels attained the largest sizes. Thus increased food availability affects growth more than increased temperature. Adult hemocyanin appeared at about the same number of weeks after the start of the experiment for crabs in the warm water/high food, warm water/low food and cold water/high food groups, even though warm water/low food crabs had molted fewer times. Crabs in the cold water/low food group expressed adult hemocyanin much later than the other groups. Molt stage and maturation from juvenile to adult are not absolutely coupled, and food availability has a greater influence than temperature on hemocyanin ontogeny.

  12. Temperature effects on hemocyanin oxygen binding in an antarctic cephalopod.

    Science.gov (United States)

    Zielinski, S; Sartoris, F J; Pörtner, H O

    2001-02-01

    The functional relevance of oxygen transport by hemocyanin of the Antarctic octopod Megaleledone senoi and of the eurythermal cuttlefish Sepia officinalis was analyzed by continuous and simultaneous recordings of changes in pH and hemocyanin oxygen saturation in whole blood at various temperatures. These data were compared to literature data on other temperate and cold-water cephalopods (octopods and giant squid). In S. officinalis, the oxygen affinity of hemocyanin changed at deltaP50/degrees C = 0.12 kPa (pH 7.4) with increasing temperatures; this is similar to observations in temperate octopods. In M. senoi, thermal sensitivity was much smaller (delta log P50/delta pH) increased with increasing temperature in both the cuttlefish and the Antarctic octopod. At low PO2 (1.0 kPa) and pH (7.2), the presence of a large venous oxygen reserve (43% saturation) insensitive to pH reflects reduced pH sensitivity and high oxygen affinity in M. senoi hemocyanin at 0 degrees C. In S. officinalis, this reserve was 19% at pH 7.4, 20 degrees C, and 1.7 kPa O2, a level still higher than in squid. These findings suggest that the lower metabolic rate of octopods and cuttlefish compared to squid is reflected in less pH-dependent oxygen transport. Results of the hemocyanin analysis for the Antarctic octopod were similar to those reported for Vampyroteuthis--an extremely high oxygen affinity supporting a very low metabolic rate. In contrast to findings in cold-adapted giant squid, the minimized thermal sensitivity of oxygen transport in Antarctic octopods will reduce metabolic scope and thereby contribute to their stenothermality.

  13. Effect of extraction temperature on the yield and physicochemical ...

    African Journals Online (AJOL)

    The chemical properties of the extracted oil at the two temperatures of 55oC and 65oC are as follows: Saponification value of 156.61 and 199.62; acid value of 12.53 and 14.40; iodine value (mg iodine/100g) of 55.23 and 52.36; peroxide value of 8.55 and 7.59 and free fatty acid (mg KOH/g) of 6.26 and 7.20 respectively.

  14. Effects of elevated CO2 and temperature on seed quality

    DEFF Research Database (Denmark)

    Hampton, John G; Boelt, Birte; Rolston, M P

    2013-01-01

    production on three seed quality components: seed mass, germination and seed vigour. In response to elevated CO2, seed mass has been reported to both increase and decrease in C3 plants, but not change in C4 plants. Increases are greater in legumes than non-legumes, and there is considerable variation among...... species. Seed mass increases may result in a decrease of seed nitrogen (N) concentration in non-legumes. Increasing temperature may decrease seed mass because of an accelerated growth rate and reduced seed filling duration, but lower seed mass does not necessarily reduce seed germination or vigour. Like...

  15. The effect and mechanism of the bipolar junction transistor in different temperature

    International Nuclear Information System (INIS)

    Wang Dong; Lu Wu; Ren Diyuan; Li Aiwu; Kuang Zhibing

    2007-01-01

    The annealing-effect of bipolar junction transistor in different temperature is investigated. It is found that the anneal of the bipolar transistor is related to the annealing-temperature, and the annealing-effect of the different type transistor is dissimilar. The possible mechanism is discussed. (authors)

  16. Combined effects of noise, vibration, and low temperature on the physiological parameters of labor employees

    Directory of Open Access Journals (Sweden)

    Pao-Chiang Chao

    2013-10-01

    Full Text Available Noise, vibration, and low temperature render specific occupational hazards to labor employees. The purpose of this research was to investigate the combined effects of these three physical hazards on employees' physiological parameters. The Taguchi experimental method was used to simulate different exposure conditions caused by noise, vibration, and low temperature, and their effects on the physiological parameters of the test takers were measured. The data were then analyzed using statistical methods to evaluate the combined effects of these three factors on human health. Results showed that the factor that influenced the finger skin temperature, manual dexterity, and mean artery pressure (MAP most was air temperature, and exposure time was the second most influential factor. Noise was found to be the major factor responsible for hearing loss; in this case, hand–arm vibration and temperature had no effect at all. During the study, the temperature was confined in the 5–25°C range (which was not sufficient to study the effects at extremely high- and low-temperature working conditions because the combined effects of even two factors were very complicated. For example, the combined effects of hand–arm vibration and low temperature might lead to occupational hazards such as vibration-induced white finger syndrome in working labors. Further studies concerning the occupational damage caused by the combined effects of hazardous factors need to be conducted in the future.

  17. The effect of temperature on the bioventing of soil contaminated with toluene and decane

    NARCIS (Netherlands)

    Malina, G.; Grotenhuis, J.T.C.; Rulkens, W.H.

    1999-01-01

    The effect of temperature on evaporation and biodegradation rates during soil bioventing (SBV) was studied for a mixture of toluene and decane in bench-scale soil columns at a continuous air flow and consecutively at two different flow rates. The effect of temperature on SBV was monitored by GC

  18. Effect of triethanolamine on the stability of furfurol at elevated temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Baiburskaya, E.L.; Kalenik, G.S.; Levchenko, E.S.; Martynenko, A.G.; Okhrimenko, N.V.; Shiryaeva, G.P.

    1982-01-01

    The effect of triethanolamine (I) on the stability of furfurol under the conditions of oil purification was studied. It was shown that (I) shows a stabilizing effect at a temperature of 200/sup 0/, which is considerably weakened on heating the furfurol in the presence of air (at atmospheric pressure). At a temperature of 230/sup 0/ (I) is not a stabilizer for furfurol.

  19. The Effect of Temperature on the Enzyme-Catalyzed Reaction: Insights from Thermodynamics

    Science.gov (United States)

    Aledo, Juan Carlos; Jimenez-Riveres, Susana; Tena, Manuel

    2010-01-01

    When teaching the effect of temperature on biochemical reactions, the problem is usually oversimplified by confining the thermal effect to the catalytic constant, which is identified with the rate constant of the elementary limiting step. Therefore, only positive values for activation energies and values greater than 1 for temperature coefficients…

  20. The effects of gender on circadian rhythm of human physiological indexes in high temperature environment

    Science.gov (United States)

    Zheng, G. Z.; Li, K.; Bu, W. T.; Lu, Y. Z.; Wang, Y. J.

    2018-03-01

    In the context of frequent high temperature weather in recent years, peoples’ physical health is seriously threatened by the indoor high temperature. The physiological activities of human body show a certain changes of circadian rhythm. In this paper, the circadian rhythms of the physiological indexes in indoor high temperature environment were quantified and compared between the male subjects and female subjects. Ten subjects (five males and five females) were selected. The temperature conditions were set at 28°C, 32°C, 36°C and 38°C, respectively. The blood pressure, heart rate, rectal temperature, eardrum temperature, forehead temperature and mean skin temperature were measured for 24 hours continuously. The medians, amplitudes and acrophases of the circadian rhythms were obtained by the cosinor analysis method. Then the effects of gender on the circadian rhythm of the human body in high temperature environment were analyzed. The results indicate that, compared with the female subjects, the male medians of the systolic pressure and diastolic pressure were higher, and the male medians of heart rate and rectal temperature were lower, however, no significant differences were found between eardrum temperature, forehead temperature and mean skin temperature. This study can provide scientific basis for the health protection of the indoor relevant personnel.

  1. A new kind of shape-stabilized PCMs with positive temperature coefficient (PTC) effect

    International Nuclear Information System (INIS)

    Cheng, Wen-long; Wu, Wan-fan; Song, Jia-liang; Liu, Yi; Yuan, Shuai; Liu, Na

    2014-01-01

    Highlights: • A new kind of shape-stabilized PCMs with PTC effect is first prepared. • It provides a potential means for the thermal control of the electronic devices. • The switching temperature of the materials is about 25 °C. • The most appropriate component of the material is found out by experimental study. • The NTC effect of the new PCMs is eliminated effectively by heat treatment. - Abstract: A new kind of shape-stabilized phase change materials (PCMs) with positive temperature coefficient (PTC) effect was prepared in this paper. The materials were prepared by adding graphite powder (GP) to the paraffin/low density polyethylene (LDPE) composite and the PTC characteristic was found by adjusting the component ratio of the material. Then the physical structures and thermal properties of the materials were investigated and the effect of various GP mass fractions and paraffin/LDPE mass proportions on the PTC behavior of the materials was studied experimentally. The results showed that the switching temperature of the materials was about 25 °C (room temperature) which approached to the first phase change temperature of paraffin dispersed in the materials. The PTC behavior of the materials was the best when the GP mass fraction and the mass proportion of LDPE/paraffin were 40 wt% and 30:70, respectively. Furthermore, the negative temperature coefficient (NTC) effect of the materials could be eliminated effectively with heat treatment. This new kind of materials is different from the former PTC materials which the switching temperatures focus on high temperature ranges. It makes up for the defect of previous materials that the switching temperatures only range in high temperature rather than room temperature and provides a potential means for the thermal control of the electronic devices or other room temperature thermal control applications

  2. Alerting and vitalizing effects of color temperature during daytime: findings on subjective and objective indicators

    NARCIS (Netherlands)

    Smolders, K.C.H.J.; Kort, de Y.A.W.; Haans, A.; Gennip, van D. A. P.; Ham, J.; Kort, de Y. A. W.

    2011-01-01

    We investigated the effects of correlated colour temperature on alertness, vitality and performance during daytime. Results of a within-groups experiment demonstrate time dependent effects on subjective indicators; objective measures are still being analysed.

  3. EFFECT OF TEMPERATURE ON THE PROCESS OF BEER PRIMARY FERMENTATION

    Directory of Open Access Journals (Sweden)

    Miriam Solgajová

    2013-02-01

    Full Text Available Beer is a very popular and widespread drink worldwide. Beer may be defined as a foamy alcoholic drink aerated by carbon dioxide that is formed during fermentation. Sensorial and analytical character of beer is mainly formed during process of primary fermentation. Our work has monitored the influence of temperature of fermentation substrate on the process of primary fermentation during beer production. Obtained values of temperature and apparent extract out of four brews of 10% light hopped wort has been recorded, during the process of primary fermentation carried out in mini brewery of SPU. We have compared our results with theoretical values of primary fermentation process commonly achieved in conditions of industrial breweries. It was found out that our results differ in some ways, moreover they exceed theoretically given values which was caused due to different construction of mini brewery fermentation tank in comparison with industrial brewery technologies. Beer produced in mini brewery of SPU showed in sensorial tests very good quality without any strange odour and any strange taste.

  4. EFFECTS OF PAVEMENT SURFACE TEMPERATURE ON THE MODIFICATION OF URBAN THERMAL ENVIRONMENT

    Directory of Open Access Journals (Sweden)

    SARAT, Adebayo-Aminu

    2012-07-01

    Full Text Available Urban centres continue to experience escalating average summer temperature over the last fifty years. Temperature in the urban core cites have been rising due to rapid growth of urbanization in the latter half of the twentieth century (Akbari et al., 1989. Outdoor experiments were conducted to investigate the effects of different movement of materials on the urban thermal environment. Meteorological conditions such as air temperature, pavement surface temperature, Relative humidity and wind velocity were recorded to determine temperature differences among Asphalt/concrete, interlocking bricks and grass surfaces.

  5. Pulse pileup effects of plasma electron temperature measurements by soft x-ray energy analysis

    International Nuclear Information System (INIS)

    Dyer, G.R.; Neilson, G.H.; Kelley, G.G.

    1978-10-01

    The electron temperature of hot plasmas is conveniently derived from bremsstrahlung spectra obtained by pulse-height analysis using a lithium-compensated silicon detector. Time-resolved temperature measurements require high counting rates, with ultimate rate limited by pulse pileup. To evaluate this limit, spectral distortion due to pileup and consequent effects on temperature determination are investigated. Expressions for distorted spectra are derived as functions of Maxwellian temperature and pileup fraction for both square and triangular pulse shapes. A comparison of temperatures obtained from distorted spectra with actual values indicates that measurements with less than 10% error can be made in the absence of line radiation, even from spectra containing 40% pileup

  6. High temperature study of flexible silicon-on-insulator fin field-effect transistors

    KAUST Repository

    Diab, Amer El Hajj

    2014-09-29

    We report high temperature electrical transport characteristics of a flexible version of the semiconductor industry\\'s most advanced architecture: fin field-effect transistor on silicon-on-insulator with sub-20 nm fins and high-κ/metal gate stacks. Characterization from room to high temperature (150 °C) was completed to determine temperature dependence of drain current (Ids), gate leakage current (Igs), transconductance (gm), and extracted low-field mobility (μ0). Mobility degradation with temperature is mainly caused by phonon scattering. The other device characteristics show insignificant difference at high temperature which proves the suitability of inorganic flexible electronics with advanced device architecture.

  7. The Effect of Elevated Temperature on Concrete Materials and Structures - a Literature Review.

    Energy Technology Data Exchange (ETDEWEB)

    Naus, Dan J [ORNL

    2006-03-01

    The objective of this limited study was to provide an overview of the effects of elevated temperature on the behavior of concrete materials and structures. In meeting this objective the effects of elevated temperatures on the properties of ordinary Portland cement concrete constituent materials and concretes are summarized. The effects of elevated temperature on high-strength concrete materials are noted and their performance compared to normal strength concretes. A review of concrete materials for elevated-temperature service is presented. Nuclear power plant and general civil engineering design codes are described. Design considerations and analytical techniques for evaluating the response of reinforced concrete structures to elevated-temperature conditions are presented. Pertinent studies in which reinforced concrete structural elements were subjected to elevated temperatures are described.

  8. The Effect of Elevated Temperature on Concrete Materials and Structures - a Literature Review

    International Nuclear Information System (INIS)

    Naus, Dan J.

    2006-01-01

    The objective of this limited study was to provide an overview of the effects of elevated temperature on the behavior of concrete materials and structures. In meeting this objective the effects of elevated temperatures on the properties of ordinary Portland cement concrete constituent materials and concretes are summarized. The effects of elevated temperature on high-strength concrete materials are noted and their performance compared to normal strength concretes. A review of concrete materials for elevated-temperature service is presented. Nuclear power plant and general civil engineering design codes are described. Design considerations and analytical techniques for evaluating the response of reinforced concrete structures to elevated-temperature conditions are presented. Pertinent studies in which reinforced concrete structural elements were subjected to elevated temperatures are described.

  9. Temperature effect on the behaviour of engineered clay barriers; Effet de la temperature sur le comportement des barrieres de confinement

    Energy Technology Data Exchange (ETDEWEB)

    Tang, A.M

    2005-11-15

    The present work deals with the thermo-hydro-mechanical behaviour of compacted swelling clay used for engineered barriers in high-level radioactive repositories. The MX80 bentonite was chosen for this work. Firstly, an experimental work on the thermal conductivity of the compacted bentonite was performed. The results evidenced the effects of dry density, water content, volumetric fraction of soil components, microstructure, and mineralogy. This experimental work gave rise to the proposition of a theoretical model for estimate the thermal conductivity of compacted bentonites. Secondly, after a calibration of suction generated by saturated saline solution in function of temperature, water retention curves were determined at different temperatures. The experimental results showed a decrease of the water retention capacity of soil after heating. A simple model based on the interfacial tension air-water was formulated to simulate this effect. Thirdly, a new isotropic cell enabling a simultaneous control of suction, temperature and mechanical stress was developed. With this new cell, an experimental work on the thermo-mechanical behaviour of the unsaturated compacted bentonite was performed. Finally, a constitutive model was developed for simulate the thermo-hydro-mechanical behaviours obtained experimentally. (author)

  10. Hyperbolic heat conduction, effective temperature, and third law for nonequilibrium systems with heat flux

    Science.gov (United States)

    Sobolev, S. L.

    2018-02-01

    Some analogies between different nonequilibrium heat conduction models, particularly random walk, the discrete variable model, and the Boltzmann transport equation with the single relaxation time approximation, have been discussed. We show that, under an assumption of a finite value of the heat carrier velocity, these models lead to the hyperbolic heat conduction equation and the modified Fourier law with relaxation term. Corresponding effective temperature and entropy have been introduced and analyzed. It has been demonstrated that the effective temperature, defined as a geometric mean of the kinetic temperatures of the heat carriers moving in opposite directions, acts as a criterion for thermalization and is a nonlinear function of the kinetic temperature and heat flux. It is shown that, under highly nonequilibrium conditions when the heat flux tends to its maximum possible value, the effective temperature, heat capacity, and local entropy go to zero even at a nonzero equilibrium temperature. This provides a possible generalization of the third law to nonequilibrium situations. Analogies and differences between the proposed effective temperature and some other definitions of a temperature in nonequilibrium state, particularly for active systems, disordered semiconductors under electric field, and adiabatic gas flow, have been shown and discussed. Illustrative examples of the behavior of the effective temperature and entropy during nonequilibrium heat conduction in a monatomic gas and a strong shockwave have been analyzed.

  11. Temperature effects in the valence fluctuation of europium intermetallic compounds

    International Nuclear Information System (INIS)

    Menezes, O.L.T. de; Troper, A.; Gomes, A.A.

    1978-03-01

    A previously reported model for valence fluctuations in europium compound in order to account for thermal occupation effect. Experimental results are critically discussed and new experiments are suggested

  12. Effect of temperature on internal structure of uranyl gels

    International Nuclear Information System (INIS)

    Landspersky, H.; Urbanek, V.

    1983-01-01

    Tempering freshly prepared uranyl gel serves the homogenization of the volume of the individual spheres and the whole volume of the processed material. Tempering is carried out at a temperature of 90 degC in a special countercurrent through-flow column. The tempered gel particles were analyzed for specific surface and porosity using different methods, subjected to phase analysis, and the crystallite mean size was determined. It was found that the quality of the final gel depends on the residence time in the tempering column. Gel recrystallization probably takes place during tempering leading to stress and cracks which in the final stage lead to the disintegration of the xerogel. Maximum permissible gel residence time in the tempering column is 15 mins. (M.D.)

  13. Effect of Temperature towards RNA Concentration: Quantitative Investigation with Spectrophotometer

    Directory of Open Access Journals (Sweden)

    Feby Fariska Savira

    2016-06-01

    Full Text Available Ribonucleic acid (RNA is a thermodynamically unstable molecule. The way RNA samples are preserved is critical to maintain maximum yield and quality, therefore it is useful for molecular analysis such as real time- PCR. There are many contradictions and variations regarding the temperature for RNA storage. The aim of this study is to find the ideal temperature to store RNA among -80o C, -20o C and 4oC by determining changes in RNA concentration over two weeks of storage time. The liver of eight rats was divided into three groups, weighing from 25-26 μg. Samples were homogenized, isolated and stored in -80oC, -20oC and 4oC freezers. Absorbance was measured with spectrophotometry at 260 and 280 nm to determine the concentration of RNA. There was no significant difference in the concentration of RNA samples stored in all temperatures after two weeks, both experimentally and statistically (Kruskal-Wallis, -80oC p=0.949; -20oC p=0.885; 4oC p=0.935. In conclusion, RNA can be stored in -80oC, -20oC and 4oC for two weeks without quantity reduction. Longer duration of study and RNA quality analysis is recommended to check for RNA degradation. Keywords: RNA, temperature, concentration, storage, spectrophotometry Efek Suhu terhadap Konsentrasi RNA: Investigasi Kuantitatif dengan Spektrofotometer Abstrak Ribonucleic acid (RNA adalah molekul yang tidak stabil secara termodinamik. Cara penyimpanan RNA sangat kritis untuk menjaga kuantitas dan kualitasnya agar dapat digunakan untuk analisis molekuler seperti real time-PCR. Tujuan penelitian ini adalah mengetahui suhu ideal penyimpanan RNA di antara -80oC, -20oC dan 4oC dengan melihat perubahan pada konsentrasi RNA selama dua minggu masa penyimpanan. Delapan hati tikus dibagi menjadi tiga kelompok dengan berat sampel 25-26 μg. Sampel hati dihomogenisasi dan diisolasi, lalu disimpan pada suhu -80oC, -20oC and 4oC. Absorbansi diukur dengan spektrofotometri pada gelombang cahaya 260 dan 280 nm untuk mendapatkan

  14. Peak effect versus skating in high-temperature nanofriction

    Science.gov (United States)

    Zykova-Timan, T.; Ceresoli, D.; Tosatti, E.

    2007-03-01

    The physics of sliding nanofriction at high temperature near the substrate melting point, TM, is so far unexplored. We conducted simulations of hard tips sliding on a prototype non-melting surface, NaCl(100), revealing two distinct and opposite phenomena for ploughing and for grazing friction in this regime. We found a frictional drop close to TM for deep ploughing and wear, but on the contrary a frictional rise for grazing, wearless sliding. For both phenomena, we obtain a fresh microscopic understanding, relating the former to `skating' through a local liquid cloud, and the latter to linear response properties of the free substrate surface. We argue that both phenomena occur more generally on surfaces other than NaCl and should be pursued experimentally. Most metals, in particular those possessing one or more close-packed non-melting surfaces, such as Pb, Al or Au(111), are likely to behave similarly.

  15. Field Effect Devices Sensitive to CO at Room Temperature

    Directory of Open Access Journals (Sweden)

    Ricardo ARAG?N

    2014-10-01

    Full Text Available [5,10,15-Tris(2,6-dichlorophenylcorrolate] cobalt(III was used to chemisorb CO selectively, on the gap-gate of MOS capacitors and the state of charge monitored by voltage shifts of the photocurrent induced by pulsed illumination under constant D. C. bias, proportionally to CO concentration in air. Negative chemically induced charges at room temperature induce positive responses above and negative shifts below the threshold voltage, conforming to acceptor behavior, and the dynamic range (125 ppm is limited by the silicon doping concentration. The linear proportionality between CO concentration and surface charge (6.46[ppm.m2.µC-1] corresponds to the low concentration limit of the Langmuir isotherm. Sluggish CO desorption can be compensated by photo stimulation at 395 nm.

  16. Effect of carbonization temperatures on biochar formation of bamboo leaves

    Science.gov (United States)

    Pattnaik, D.; Kumar, S.; Bhuyan, S. K.; Mishra, S. C.

    2018-03-01

    Bamboo is a typical plant native in Asia, been used in many sectors, which also produces a large volume of leaves which goes waste and not find its application for any useful purposes; is often considered as a bio-waste and normally incinerated or dumped; as its applications are not yet fully explored. However, some research work done on bamboo fibers for use as a reinforcement in making polymer matrix composite. In the present piece of research work, the influence of burning/carbonization of bamboo leaves (at different temperatures) have been studied and characterized. Proximate analysis gave the fixed carbon content (of ~nearly21%). X-Ray diffraction results revealed the presence of various phases viz. cristobalite (SiO2), Calcite (Ca2O3) etc. accompanied with changes in crystal structures. Fourier transform infrared spectroscopy results showed various modes of vibrations viz. O-H stretching bending of other bonds; (for aromatic benzene derivatives) etc. Scanning Electron Microscopic observation (of morphology) showed irregular stacking arrangements between the randomly spaced lamellae structure, with variation in carbonizing temperature. Results revealed the advantages of pyrolysis process in biochar production/formation. It appears that, the bamboo biochar can have suitable properties for its use as an alternative energy source and also for agricultural applications. Its high porosity and carbon content suggest its application as activated carbon also; after physical or chemical treatments. The present research focuses on extending the frontiers of use of bamboo leaves from being an unutilized biowaste to its conversion into a value added product, which can be compassed in terms of sustainable applications.

  17. Numerical simulation of the temperature effects on the performance of rotational supercavitating evaporator

    International Nuclear Information System (INIS)

    Zheng, Z Y; Cheng, J P; Li, F C; Zhang, M; Li, Q; Kulagin, V A

    2015-01-01

    With the application of supercavitation effect, a novel device named Rotational Supercavitating Evaporator (RSCE) has been designed for desalination. In order to study the effect of temperature on the performance of RSCE and then direct the experimental study on RSCE for the next step, numerical simulations are conducted on the supercavitating flows in RSCE under different temperatures and rotational speeds. The results show that the rotational speed, resistance moment and mechanical energy consumed by the rotational cavitator under the critical state with the largest supercavity, decrease with the increase of temperature. And the area and volume of the supercavity increase exponentially with the increase of temperature under the same rotational speed

  18. Effect of aging on the martensitic transformation temperature in Ag-Zn-Al alloys

    International Nuclear Information System (INIS)

    Takezawa, K.; Hoshi, H.; Marukawa, K.

    2000-01-01

    The relation between atomic ordering and martensitic transformation temperature, M s , in Ag-Zn-Al alloys was examined mainly by means of electrical resistivity measurements. Disordered bcc phase was frozen-in by quenching from a temperature above the critical temperature for ordering, T c . In a Ag-22.3at%Zn-8.9at%Al alloy, the M s temperature has been found to decrease by aging in the parent phase at temperatures between 253 and 293 K. The resistivity also decreased in accord with the M s temperature. This indicates that atomic ordering proceeds by aging. The relation between the decrease in the reverse transformation temperature, A f , and the degree of long range order was obtained. In a Ag-11.0at%Zn-15.5at%Al alloy, in which the M s temperature in the as-quenched state is higher and the T c temperature is lower than that of the former alloy, aging in the martensite phase was performed. In this case, the aging brought about the increase in the A f temperature. This is in contrast to the results of aging in the parent phase. Furthermore, the effect of aging in the parent phase at temperatures higher than T c was examined. Both the transformation temperature and the resistivity were found to become higher. These changes are due to lowering in the degree of short range order. (orig.)

  19. Effect of high temperature deposition on CoSi2 phase formation

    International Nuclear Information System (INIS)

    Comrie, C. M.; Ahmed, H.; Smeets, D.; Demeulemeester, J.; Vantomme, A.; Turner, S.; Van Tendeloo, G.; Detavernier, C.

    2013-01-01

    This paper discusses the nucleation behaviour of the CoSi to CoSi 2 transformation from cobalt silicide thin films grown by deposition at elevated substrate temperatures ranging from 375 °C to 600 °C. A combination of channelling, real-time Rutherford backscattering spectrometry, real-time x-ray diffraction, and transmission electron microscopy was used to investigate the effect of the deposition temperature on the subsequent formation temperature of CoSi 2 , its growth behaviour, and the epitaxial quality of the CoSi 2 thus formed. The temperature at which deposition took place was observed to exert a significant and systematic influence on both the formation temperature of CoSi 2 and its growth mechanism. CoSi films grown at the lowest temperatures were found to increase the CoSi 2 nucleation temperature above that of CoSi 2 grown by conventional solid phase reaction, whereas the higher deposition temperatures reduced the nucleation temperature significantly. In addition, a systematic change in growth mechanism of the subsequent CoSi 2 growth occurs as a function of deposition temperature. First, the CoSi 2 growth rate from films grown at the lower reactive deposition temperatures is substantially lower than that grown at higher reactive deposition temperatures, even though the onset of growth occurs at a higher temperature, Second, for deposition temperatures below 450 °C, the growth appears columnar, indicating nucleation controlled growth. Elevated deposition temperatures, on the other hand, render the CoSi 2 formation process layer-by-layer which indicates enhanced nucleation of the CoSi 2 and diffusion controlled growth. Our results further indicate that this observed trend is most likely related to stress and changes in microstructure introduced during reactive deposition of the CoSi film. The deposition temperature therefore provides a handle to tune the CoSi 2 growth mechanism.

  20. Analyzing the effect of tool edge radius on cutting temperature in micro-milling process

    Science.gov (United States)

    Liang, Y. C.; Yang, K.; Zheng, K. N.; Bai, Q. S.; Chen, W. Q.; Sun, G. Y.

    2010-10-01

    Cutting heat is one of the important physical subjects in the cutting process. Cutting heat together with cutting temperature produced by the cutting process will directly have effects on the tool wear and the life as well as on the workpiece processing precision and surface quality. The feature size of the workpiece is usually several microns. Thus, the tiny changes of cutting temperature will affect the workpiece on the surface quality and accuracy. Therefore, cutting heat and temperature generated in micro-milling will have significantly different effect than the one in the traditional tools cutting. In this paper, a two-dimensional coupled thermal-mechanical finite element model is adopted to determine thermal fields and cutting temperature during the Micro-milling process, by using software Deform-2D. The effect of tool edge radius on effective stress, effective strain, velocity field and cutting temperature distribution in micro-milling of aluminum alloy Al2024-T6 were investigated and analyzed. Also, the transient cutting temperature distribution was simulated dynamically. The simulation results show that the cutting temperature in Micro-milling is lower than those occurring in conventional milling processes due to the small loads and low cutting velocity. With increase of tool edge radius, the maximum temperature region gradually occurs on the contact region between finished surfaced and flank face of micro-cutter, instead of the rake face or the corner of micro-cutter. And this phenomenon shows an obvious size effect.

  1. Effects of temperature variations on guided waves propagating in composite structures

    Science.gov (United States)

    Shoja, Siavash; Berbyuk, Viktor; Boström, Anders

    2016-04-01

    Effects of temperature on guided waves propagating in composite materials is a well-known problem which has been investigated in many studies. The majority of the studies is focused on effects of high temperature. Understanding the effects of low temperature has major importance in composite structures and components which are operating in cold climate conditions such as e.g. wind turbines operating in cold climate regions. In this study first the effects of temperature variations on guided waves propagating in a composite plate is investigated experimentally in a cold climate chamber. The material is a common material used to manufacture rotor blades of wind turbines. The temperature range is 25°C to -25°C and effects of temperature variations on amplitude and phase shift of the received signal are investigated. In order to apply the effects of lowering the temperature on the received signal, the Baseline Signal Stretch (BSS) method is modified and used. The modification is based on decomposing the signal into symmetric and asymmetric modes and applying two different stretch factors on each of them. Finally the results obtained based on the new method is compared with the results of application of BSS with one stretch factor and experimental measurements. Comparisons show that an improvement is obtained using the BSS with the mode decomposition method at temperature variations of more than 25°C.

  2. Effect of temperatures up to 130 deg C on the responses of TLD 700

    Energy Technology Data Exchange (ETDEWEB)

    Douglas, J A; Binns, P J [UKAEA Atomic Energy Research Establishment, Harwell. Environmental and Medical Sciences Div.

    1984-01-01

    The need to measure doses at temperatures up to 130 deg C led to an investigation into the effect of exposure and storage at these temperatures on the response of TLD 700 before and after UV phototransfer. As a preliminary, the delays required during the UV re-estimation process were optimised. The effects of storage and exposure were compared. This was followed by a detailed examination of the effects of storage at temperatures up to 130 deg C. Glow curves were analysed to investigate the rates of growth and decay of the different peaks. The findings for peaks 6 and 7 are compatible with previously reported effects at lower temperatures on peaks 3, 4 and 5. Storage at temperatures of 130 deg C or below for periods up to 28 days does not affect the UV photo-transfer response.

  3. Compressibility, zero sound, and effective mass of a fermionic dipolar gas at finite temperature

    International Nuclear Information System (INIS)

    Kestner, J. P.; Das Sarma, S.

    2010-01-01

    The compressibility, zero-sound dispersion, and effective mass of a gas of fermionic dipolar molecules is calculated at finite temperature for one-, two-, and three-dimensional uniform systems, and in a multilayer quasi-two-dimensional system. The compressibility is nonmonotonic in the reduced temperature, T/T F , exhibiting a maximum at finite temperature. This effect might be visible in a quasi-low-dimensional experiment, providing a clear signature of the onset of many-body quantum degeneracy effects. The collective mode dispersion and effective mass show similar nontrivial temperature and density dependence. In a quasi-low-dimensional system, the zero-sound mode may propagate at experimentally attainable temperatures.

  4. Effect of External Pressure Drop on Loop Heat Pipe Operating Temperature

    Science.gov (United States)

    Jentung, Ku; Ottenstein, Laura; Rogers, Paul; Cheung, Kwok; Obenschain, Arthur F. (Technical Monitor)

    2002-01-01

    This paper discusses the effect of the pressure drop on the operating temperature in a loop heat pipe (LHP). Because the evaporator and the compensation chamber (CC) both contain two-phase fluid, a thermodynamic constraint exists between the temperature difference and the pressure drop for these two components. As the pressure drop increases, so will the temperature difference. The temperature difference in turn causes an increase of the heat leak from the evaporator to the CC, resulting in a higher CC temperature. Furthermore, the heat leak strongly depends on the vapor void fraction inside the evaporator core. Tests were conducted by installing a valve on the vapor line so as to vary the pressure drop, and by charging the LHP with various amounts of fluid. Test results verify that the LHP operating temperature increases with an increasing differential pressure, and the temperature increase is a strong function of the fluid inventory in the loop.

  5. Climate change, global warming and coral reefs: modelling the effects of temperature.

    Science.gov (United States)

    Crabbe, M James C

    2008-10-01

    Climate change and global warming have severe consequences for the survival of scleractinian (reef-building) corals and their associated ecosystems. This review summarizes recent literature on the influence of temperature on coral growth, coral bleaching, and modelling the effects of high temperature on corals. Satellite-based sea surface temperature (SST) and coral bleaching information available on the internet is an important tool in monitoring and modelling coral responses to temperature. Within the narrow temperature range for coral growth, corals can respond to rate of temperature change as well as to temperature per se. We need to continue to develop models of how non-steady-state processes such as global warming and climate change will affect coral reefs.

  6. Effect of temperature on the AC impedance of protein and ...

    Indian Academy of Sciences (India)

    tunnelling model, gum acacia and gum guar obey ion or electron tunnelling model, and gum tragacanth obeys the correlated .... The conductivity is derived from the resistance value .... effect affects the chain alignment, leads to the increase.

  7. Hysteresis effects on the high-temperature internal friction of polycrystalline zirconium

    International Nuclear Information System (INIS)

    Povolo, F.; Molinas, B.J.; Rosario Univ. Nacional

    1985-01-01

    Hysteresis effects present on the high temperature internal friction of annealed polycrystalline zirconium are investigated in detail. It is shown that two internal friction maxima are present when the measurements are performed on heating. If a high enough temperature is reached, only one internal friction maximum is observed on cooling. Furthermore, when the temperature is not decreased below a certain value (critical temperature) only the lower temperature peak is present during a subsequent heating cycle. The critical temperature is strongly dependent on the grain size. Finally, both the hysteresis effects and the internal friction maxima are explained by relaxation mechanisms associated with grain boundary sliding and segregation of impurities to the grain boundaries. (author)

  8. Numerical studies of temperature effect on the extrusion fracture and swell of plastic micro-pipe

    Science.gov (United States)

    Ren, Zhong; Huang, Xingyuan; Xiong, Zhihua

    2018-03-01

    Temperature is a key factor that impacts extrusion forming quality of plastic micro-pipe. In this study, the effect of temperature on extrusion fracture and swell of plastic micro-pipe was investigated by numerical method. Under a certain of the melt’s flow volume, the extrusion pattern, extrusion swelling ratio of melt are obtained under different temperatures. Results show that the extrusion swelling ratio of plastic micro-pipe decreases with increasing of temperature. In order to study the reason of temperature effect, the physical distributions of plastic micro-pipe are gotten. Numerical results show that the viscosity, pressure, stress value of melt are all decreased with the increasing of temperature, which leads to decrease the extrusion swell and fracture phenomenon for the plastic micro-pipe.

  9. High autumn temperature delays spring bud burst in boreal trees, counterbalancing the effect of climatic warming

    Energy Technology Data Exchange (ETDEWEB)

    Heide, O. M. [Agricultural Univesity of Norway, Department of Biology and Nature Conservation, As (Norway)

    2003-09-01

    The effect of temperature during short-day dormancy induction on the duration and stability of bud dormancy was examined in three boreal tree species (2 birches and 1 alder) grown in a controlled environment. The phenology of the latitudinal range of birch populations, and the relationship between spring bud burst and autumn and spring temperatures were also studied. Results showed that during short-day dormancy induction in the autumn high temperatures delayed bud burst in the following spring in both controlled and natural environments. It is suggested that this response to higher autumn temperatures may be a manifestation of a general synergism between high temperature and short-day photoperiodic processes, and may be an adaptive mechanism common to boreal trees. It is further conjectured that this mechanism may be important in counterbalancing the potentially adverse effects of higher winter temperatures on dormancy stability of boreal trees during climate warming. 23 refs., 2 tabs., 4 figs.

  10. Effect of preliminary plastic deformation on low temperature strength of carbon steels

    International Nuclear Information System (INIS)

    Gur'ev, A.V.; Alkhimenkov, T.B.

    1979-01-01

    Considered is the effect of preliminary plastic deformation on the following low-temperature strength (at -196 deg C) of structural carbon steels at the room temperature. The study of regularities of microheterogenetic deformations by alloy structure elements at room and low temperatures shows that the transition on low -temperature loading is built on the base of inheritance of the general mechanism of plastic deformation, which took place at preliminary deformation; in this effect the ''memory'' of metal to the history of loading is shown. It is established that physical strengthening (cold hardening), received by the metal during preliminary loading at the room temperature is put over the strengthening connected only with decrease of test temperature

  11. Three-dimensional temperature effect modelling of piezoceramic transducers used for Lamb wave based damage detection

    International Nuclear Information System (INIS)

    Kijanka, Piotr; Packo, Pawel; Staszewski, Wieslaw J; Zhu, Xuan; Di Scalea, Francesco Lanza

    2015-01-01

    The paper presents a three-dimensional temperature-dependent model of surface-bonded, low-profile piezoceramic transducers (PZT) used for Lamb wave propagation. The effect of temperature on Lamb wave actuation, propagation and sensing is investigated. The major focus is on the study of actuation and sensing properties of PZT for various temperature levels. These properties are investigated through the electric field analysis of transducers. The temperature effect on transducer bond layers is also investigated. Numerically simulated amplitude responses are analysed for various temperatures and excitation frequencies. Numerical simulations are validated experimentally. The results demonstrate that temperature-dependent physical properties of PZT, bond layers and particularly host structures significantly affect the amplitude and phase of Lamb wave responses. (paper)

  12. Couplings in multiphasic geo-materials: temperature and chemistry effects

    International Nuclear Information System (INIS)

    Ghasemzadeh, H.

    2006-05-01

    Transport of chemical components in soil through water is the major cause of pollution of the soil. This transport takes place around landfills and nuclear waste storage areas, tailings and mine wastes, and so on. A great number of these sites are unsaturated of water and in some cases heat can change the fate of chemical species, that lead us to a coupled problem. In this dissertation, numerical simulation with an existent thermo-hydro-mechanical model and theoretical modeling and numerical simulation of transport and interactions of one chemical species in multiphase media are presented. Integrated THM model in the Code-Aster is presented. Excavation, engineering barrier and thermal load of waste nuclear storage well are modeled. Verification of model is presented with these simulations. A thermo-hydro-mechanical behaviour coupled with chemical phenomena is presented with a fully coupled method that water, gas, chemical species and soil skeleton were considered as constituents and corresponding unknowns are temperature, water pressure, gas pressure, chemical concentration and displacements. For each constituent, mass balance equation and linear momentum equation are written and solved simultaneously to find related unknowns. The results of this model have been compared with the theoretical and experimental results existing in the literature. Furthermore, results of some applications of this model are included. Some areas where further work is required are identified. In particular, there is a need to perform experiments to obtain necessary soil parameters to permit accurate modelling of the heat and contaminant transport in unsaturated soils. (author)

  13. low temperature irradiation effects in iron-alloys and ceramics

    International Nuclear Information System (INIS)

    Kuramoto, Eiichi; Abe, Hironobu; Tanaka, Minoru; Nishi, Kazuya; Tomiyama, Noriyuki.

    1991-01-01

    Electron beam irradiation at 77K and neutron irradiation at 20K were carried out on Fe-Cr and Fe-Cr-Ni alloys and ZnO and graphite system ceramics, and by measuring positron annihilation lifetime, the micro-information about irradiation-introduced defects was obtained. The temperature of the movement of atomic vacancies in pure iron is about 200K, but it was clarified that by the addition of Cr, it was not much affected. However, in the case of high concentration Cr alloys, the number of atomic vacancies which take part in the formation of micro-voids decreased as compared with the case of pure iron. It is considered that among the irradiation defects of ZnO, O-vac. restored below 300degC. It is considered that in the samples without irradiation, the stage of restoration exists around 550degC, which copes with structural defects. By the measurement of graphite without irradiation, the positron annihilation lifetime corresponding with the interface of matrix and crystal grains, grain boundaries and internal surfaces was almost determined. The materials taken up most actively in the research and development of nuclear fusion reactor materials are austenitic and ferritic stainless steels, and their irradiation defects have been studied. (K.I.)

  14. Effects of high temperature surface oxides on room temperature aqueous corrosion and environmental embrittlement of iron aluminides

    Energy Technology Data Exchange (ETDEWEB)

    Buchanan, R.A.; Perrin, R.L.

    1996-09-01

    Studies were conducted to determine the effects of high-temperature surface oxides, produced during thermomechanical processing, heat treatment (750 {degrees}C in air, one hour) or simulated in-service-type oxidation (1000{degrees}C in air, 24 hours) on the room-temperature aqueous-corrosion and environmental-embrittlement characteristics of iron aluminides. Materials evaluated included the Fe{sub 3}Al-based iron aluminides, FA-84, FA-129, FAL and FAL-Mo, a FeAl-based iron aluminide, FA-385, and a disordered low-aluminum Fe-Al alloy, FAPY. Tests were performed in a mild acid-chloride solution to simulate aggressive atmospheric corrosion. Cyclic-anodic-polarization tests were employed to evaluate resistances to localized aqueous corrosion. The high-temperature oxide surfaces consistently produced detrimental results relative to mechanically or chemically cleaned surfaces. Specifically, the pitting corrosion resistances were much lower for the as-processed and 750{degrees} C surfaces, relative to the cleaned surfaces, for FA-84, FA-129, FAL-Mo, FA-385 and FAPY. Furthermore, the pitting corrosion resistances were much lower for the 1000{degrees}C surfaces, relative to cleaned surfaces, for FA-129, FAL and FAL-Mo.

  15. Growth temperature and dopant species effects on deep levels in Si grown by low temperature molecular beam epitaxy

    International Nuclear Information System (INIS)

    Chung, Sung-Yong; Jin, Niu; Rice, Anthony T.; Berger, Paul R.; Yu, Ronghua; Fang, Z-Q.; Thompson, Phillip E.

    2003-01-01

    Deep-level transient spectroscopy measurements were performed in order to investigate the effects of substrate growth temperature and dopant species on deep levels in Si layers during low-temperature molecular beam epitaxial growth. The structures studied were n + -p junctions using B doping for the p layer and p + -n junctions using P doping for the n layer. While the density of hole traps H1 (0.38-0.41 eV) in the B-doped p layers showed a clear increase with decreasing growth temperature from 600 to 370 degree sign C, the electron trap density was relatively constant. Interestingly, the minority carrier electron traps E1 (0.42-0.45 eV) and E2 (0.257 eV), found in the B-doped p layers, are similar to the majority carrier electron traps E11 (0.48 eV) and E22 (0.269 eV) observed in P-doped n layers grown at 600 degree sign C. It is hypothesized that these dominating electron traps are associated with pure divacancy defects and are independent of the dopant species

  16. Soil surface temperatures reveal moderation of the urban heat island effect by trees and shrubs.

    Science.gov (United States)

    Edmondson, J L; Stott, I; Davies, Z G; Gaston, K J; Leake, J R

    2016-09-19

    Urban areas are major contributors to air pollution and climate change, causing impacts on human health that are amplified by the microclimatological effects of buildings and grey infrastructure through the urban heat island (UHI) effect. Urban greenspaces may be important in reducing surface temperature extremes, but their effects have not been investigated at a city-wide scale. Across a mid-sized UK city we buried temperature loggers at the surface of greenspace soils at 100 sites, stratified by proximity to city centre, vegetation cover and land-use. Mean daily soil surface temperature over 11 months increased by 0.6 °C over the 5 km from the city outskirts to the centre. Trees and shrubs in non-domestic greenspace reduced mean maximum daily soil surface temperatures in the summer by 5.7 °C compared to herbaceous vegetation, but tended to maintain slightly higher temperatures in winter. Trees in domestic gardens, which tend to be smaller, were less effective at reducing summer soil surface temperatures. Our findings reveal that the UHI effects soil temperatures at a city-wide scale, and that in their moderating urban soil surface temperature extremes, trees and shrubs may help to reduce the adverse impacts of urbanization on microclimate, soil processes and human health.

  17. Effects of alloying and temperature on the high-temperature oxidation of Cr-Cr{sub 2}Nb

    Energy Technology Data Exchange (ETDEWEB)

    Tortorelli, P.F.; DeVan, J.H. [Oak Ridge National Lab., TN (United States); Carson, L.J. [Lincoln Univ., PA (United States)

    1993-06-01

    Effects of alloying additions and temperature on isothermal and cyclic oxidation resistance of Cr-Cr{sub 2}Nb alloys were examined for air exposures. An isothermal exposure temperature of 1100C led to rapid reaction of binary Cr-12 at.% Nb as manifested a high oxidation rate and nonprotective behavior. Generally parabolic kinetics, complicated by some isothermal scale cracking, were observed at 900--1000C. Scale damage was exacerbated by thermal cycling. The addition of 8 at.% Al to Cr-12 at.% Nb did not effect cyclic oxidation resistance, but there was some evidence that scale adherence on Cr-6 at.% Nb-8 at.% Al was better than that for binary Cr-6 at.% Nb. Alloying additions of Al (up to 18 at.%) or Re (2 at.%) did not improve the isothermal oxidation resistance of Cr-12 at.% Nb. However, the tendency for scale damage during both isothermal and thermal cycling exposures suggests that alloying additions that specifically improve scale plasticity or modify growth stresses could be effective for Cr-Nb alloys. 10 refs, 9 figs, 1 tab.

  18. Effects of Temperature,Mother of Vinegar, and Amount of Sugar on AroniamelanocarpaChokeberry Fermentation

    OpenAIRE

    Won Sik Choi; Soon Hong Kwon; Sung Won Chung; Soon Goo Kwon; Jong Min Park; Jong Soon Kim; Destiani Supeno

    2016-01-01

    This study evaluatesthe effects of temperature, mother of vinegar, and amount of sugaron the fermentation of black chokeberry (Aroniamelanocarpa). To investigate temperature, samples of black chokeberrieswere compared after fermentation in a thermostat incubator (T 40ᵒC) and at room temperature (T 25ᵒC). Six mothers of vinegar were also used: white grape vinegar, brown rice black vinegar (pomegranate), brown rice black vinegar (blackberry and blueberry), pomegranate vinegar, brown rice vinega...

  19. Effective temperatures of late-type stars: The field giants from K0 to M6

    International Nuclear Information System (INIS)

    Ridgway, S.T.; Joyce, R.R.; White, N.M.; Wing, R.F.

    1980-01-01

    Angular diameters from lunar occultation are combined with infrared photometry to determine effective temperatures, T/sub eff/, for K0--M6 giants. The relation between T/sub eff/ and color temperature, MK spectral type, V--K color, and I (104) --L color are derived. The principal result is a general increase in T/sub eff/ for the cooler spectral types compared to previous calibrations. Throughout the temperature range studied, we obtain excellent agreement with recent model atmosphere computations

  20. Inconsistent effects of developmental temperatureacclimation on low-temperature performance andmetabolism in Drosophila melanogaster

    DEFF Research Database (Denmark)

    Kristensen, Torsten Nygaard; Overgaard, Johannes; Hoffmann, Ary A

    2012-01-01

    Question: Does acclimation to developmental temperature consistently affect metabolismand low-temperature performance when measured in different laboratory and field assays? Hypothesis: Developmental acclimation reflecting naturally fluctuating thermal conditionsconsistently increases different...... conditions in the field, while constant cool rearingconditions led to high cold resistance. The fluctuating- and low-temperature rearing conditionsresulted in a similar metabolic profile, while the 24C rearing profile was distinct and showeda lack of plasticity. The effects of developmental acclimation...

  1. The effect of various sintering temperature on used refractory towards its physical properties

    Science.gov (United States)

    Sudibyo; Wulandari, Y. R.; Amin, M.; Azhar

    2018-01-01

    The used magnesia refractory from the kiln of cement industry was successfully recycled to new refractory using Kaolin as an adhesive. In this work, the temperatures of sintering were varied from 1000°C to 1500°C. The result shows that the increment temperature effects in sintering process will enhance refractory physical properties such as bulk density, cold crushing strength or pressure strength and thermal conductivity. Meanwhile, the porosity was decreased as the increase of the sintering temperature.

  2. Temperature and pressure effects on 40Ar-39Ar systematics

    International Nuclear Information System (INIS)

    Ozima, M.; Kaneoka, I.; Yanagisawa, M.

    1979-01-01

    The effects of thermal and compressional treatment on 40 Ar- 39 Ar systematics have been investigated on three artificially heated biotite samples (heated for 1 hour at 700 0 C and 860 0 C in air and 700 0 C in vacuum respectively) and uniaxially compressed granite (p=1400 bar) and basalt samples (p=1660 bar). The 40 Ar- 39 Ar results for the disturbed samples are compared with those for undisturbed samples. Except for the vacuum-heating case, the effects of the disturbances may be interpreted as the combined effect of a partial loss of radiogenic 40 Ar from the sample and an incorporation of air Ar into the sample. Common diagnostic effects are (1) reduction of the total fusion age, (2) distortion of the age spectrum and, if the degree of the partial Ar loss is small (3) approximate preservation of the isochron age, and (4) reduction of the intercept value ( 40 Ar/ 36 Ar) in the isochron plot. The features observed in the age spectra of artificially disturbed samples are rather common in geologically disturbed samples, suggesting that the artificial disturbances simulate the effects of geological disturbances on 40 Ar- 39 Ar systematics. (Auth.)

  3. Finite temperature effects in Bose-Einstein condensed dark matter halos

    International Nuclear Information System (INIS)

    Harko, Tiberiu; Madarassy, Enikö J.M.

    2012-01-01

    Once the critical temperature of a cosmological boson gas is less than the critical temperature, a Bose-Einstein Condensation process can always take place during the cosmic history of the universe. Zero temperature condensed dark matter can be described as a non-relativistic, Newtonian gravitational condensate, whose density and pressure are related by a barotropic equation of state, with barotropic index equal to one. In the present paper we analyze the effects of the finite dark matter temperature on the properties of the dark matter halos. We formulate the basic equations describing the finite temperature condensate, representing a generalized Gross-Pitaevskii equation that takes into account the presence of the thermal cloud. The static condensate and thermal cloud in thermodynamic equilibrium is analyzed in detail, by using the Hartree-Fock-Bogoliubov and Thomas-Fermi approximations. The condensed dark matter and thermal cloud density and mass profiles at finite temperatures are explicitly obtained. Our results show that when the temperature of the condensate and of the thermal cloud are much smaller than the critical Bose-Einstein transition temperature, the zero temperature density and mass profiles give an excellent description of the dark matter halos. However, finite temperature effects may play an important role in the early stages of the cosmological evolution of the dark matter condensates

  4. Environmental control of drilling mud discharge through dewatering in cold weather climates: effect of ambient temperature

    Energy Technology Data Exchange (ETDEWEB)

    Wojtanowicz, A. K. [Louisiana State Univ., Baton Rouge, LA (United States); Ye, Y. [Jianghan Petroleum Institute, Beijing, (China)

    1998-05-01

    Results of an experimental study of the effects of drilling mud temperature upon dewatering performance at various temperatures were presented. Three temperature ranges (from flowline temperature to room temperature, from room temperature to freezing point, and freeze/thaw, i.e. from -20 degrees C to 12 degrees C) were considered. Both unweighted and weighted fresh water muds and weighted salt water mud were tested using a sealed laboratory batch reactor, to prevent rapid vaporization of separated water at temperatures above 60 degrees C. Deep freezing was achieved by using ice or ice-salt baths. Net water removal was measured with a bench-top plate press under constant expression pressure of 270 kPa. Results showed that the freeze/thaw treatment process proved to be very effective, enhancing water removal by 34 to 39 per cent, and reducing waste mud volume by 64 to 72 per cent. No advantage to dewatering hot drilling mud from active systems was observed at temperatures above 21 degrees C. It was suggested that at temperatures under 21 degrees C, the waste drilling mud diverted from an active system should be dewatered when its temperature is still over 40 degrees C. to reduce the amount of chemicals needed for separation enhancement. 14 refs., 4 tabs., 4 figs.

  5. Effects of temperature on development, mortality, mating and blood feeding behavior of Culiseta incidens (Diptera: Culicidae).

    Science.gov (United States)

    Su, T; Mulla, M S

    2001-06-01

    Culiseta incidens Thomson is distributed over most of the western USA and Canada northward to Alaska. Because this mosquito is difficult to colonize, its biology has not been well investigated. We colonized this species in 1998 and studied the effects of temperature on various aspects of its life cycle. The time required for egg melanization and the duration of the egg stage were negatively correlated with temperature. The proportion of fertile egg rafts was temperature-independent. An inverse relationship existed between temperature and egg hatch. Molting and stadium duration after hatching were temperature-dependent, with higher temperature accelerating development and molting. Larvae and pupae experienced lower mortality and higher molting success at lower temperatures. Survivorship of adult mosquitoes fed on sugar solution was inversely proportional to temperature, lethal times for 50% mortality (LT50) were greater at the lower temperature than at the higher temperature. Females survived longer than did males at all test temperatures. Because this species is eurygamous, mating only occurred in large cages. Mating success was also affected by temperature. At the test temperatures, 20 degrees C, 25 degrees C and 30 degrees C, mating started from 3-5 days after emergence and reached a peak on days 13-15 after emergence. Maximum mating rates at 20 degrees C and 25 degrees C were higher than at 30 degrees C. Blood feeding, as indicated by cumulative feeding rates, was affected by cage size, mosquito age and temperature. Mosquitoes in large cages exhibited a much higher feeding rate than in small cages. With age, the cumulative blood feeding rate increased, with the highest rate at 25 degrees C, followed by 20 degrees C and 30 degrees C. At all temperatures tested, most of the blood fed females were mated.

  6. Temperature effect on microstructure and P-wave propagation in Linyi sandstone

    International Nuclear Information System (INIS)

    Sun, Hui; Sun, Qiang; Deng, Wenni; Zhang, Weiqiang; Lü, Chao

    2017-01-01

    Highlights: • Mass loss rate, P-wave velocity change rate and damage factor increase exponentially as temperatures rise. • The damage threshold temperature of sandstone samples is 300 °C and limit temperature is 900 °C. • P-wave velocity change rate of sandstone exhibits excellent linearity with mass loss rate. • Damage factor can be well expressed by mass loss rate. - Abstract: In order to study the effect of high temperature on the sandstone, scanning electron microscope (SEM) experiments and primary wave (P-wave) velocity tests have been carried out on sandstone specimens heated to different temperature. The results showed that: (1) the mass loss rate increases exponentially with the increase of temperature and reaches 2.97% at 900 °C; (2) the P-wave velocity change rate increases exponentially with the increase of temperature while there is some fluctuation before 500 °C; (3) the damage threshold temperature of sandstone samples is 300 °C and the limit temperature is 900 °C; (4) there is a good linear relationship between the mass loss rate and the P-wave velocity change rate, and the correlation coefficient (R) of the fitting line is 0.989; (5) the damage caused by high temperature can be reflected better by the mass loss rate than P-wave velocity change rate. The results obtained in this paper will be good for predicting the properties of sandstone when exposed to high temperature.

  7. Temperature effects on snapping performance in the common snapper Chelydra serpentina (Reptilia, Testudines).

    Science.gov (United States)

    Vervust, Bart; Brecko, Jonathan; Herrel, Anthony

    2011-01-01

    Studies on the effect of temperature on whole-animal performance traits other than locomotion are rare. Here we investigate the effects of temperature on the performance of the turtle feeding apparatus in a defensive context. We measured bite force and the kinematics of snapping in the Common Snapping Turtle (Chelydra serpentina) over a wide range of body temperatures. Bite force performance was thermally insensitive over the broad range of temperatures typically experienced by these turtles in nature. In contrast, neck extension (velocity, acceleration, and deceleration) and jaw movements (velocity, acceleration, and deceleration) showed clear temperature dependence with peak acceleration and deceleration capacity increasing with increasing temperatures. Our results regarding the temperature dependence of defensive behavior are reflected by the ecology and overall behavior of this species. These data illustrate the necessity for carefully controlling T(b) when carrying out behavioral and functional studies on turtles as temperature affects the velocity, acceleration, and deceleration of jaw and neck extension movements. More generally, these data add to the limited but increasing number of studies showing that temperature may have important effects on feeding and defensive performance in ectotherms. © 2010 Wiley-Liss, Inc.

  8. Potential effects of diurnal temperature oscillations on potato late blight with special reference to climate change.

    Science.gov (United States)

    Shakya, S K; Goss, E M; Dufault, N S; van Bruggen, A H C

    2015-02-01

    Global climate change will have effects on diurnal temperature oscillations as well as on average temperatures. Studies on potato late blight (Phytophthora infestans) development have not considered daily temperature oscillations. We hypothesize that growth and development rates of P. infestans would be less influenced by change in average temperature as the magnitude of fluctuations in daily temperatures increases. We investigated the effects of seven constant (10, 12, 15, 17, 20, 23, and 27°C) and diurnally oscillating (±5 and ±10°C) temperatures around the same means on number of lesions, incubation period, latent period, radial lesion growth rate, and sporulation intensity on detached potato leaves inoculated with two P. infestans isolates from clonal lineages US-8 and US-23. A four-parameter thermodynamic model was used to describe relationships between temperature and disease development measurements. Incubation and latency progression accelerated with increasing oscillations at low mean temperatures but slowed down with increasing oscillations at high mean temperatures (P effects of global climate change on disease development.

  9. Coupled effects of the temperature and the relative humidity on gecko adhesion

    International Nuclear Information System (INIS)

    Peng, Zhilong; Yang, Yazheng; Chen, Shaohua

    2017-01-01

    To explain the inconsistent results of experiments on temperature-dependent gecko adhesion, a theoretical peeling model is established wherein a nano-thin film is adopted to simulate a gecko spatula. The model considers not only the respective effects of temperature and environmental humidity on the peel-off force but also the coupled effect of both factors. Increasing temperature is found to lead to a decreasing peel-off force if the environmental humidity is uncontrolled. However, if the environmental humidity is constant, the peel-off force is insensitive to the temperature and remains almost constant. The synthetic theoretical analysis demonstrates that the seemingly contradictory results of temperature-dependent gecko adhesion experiments are actually consistent under their respective experimental conditions. This inconsistency is mainly due to the environmental humidity, which varies with the changing temperature if it is not artificially controlled. The results cannot only reasonably explain the different experimental results for the effect of temperature on gecko adhesion but can also facilitate the design of temperature-controlled or humidity-controlled adhesion sensors by tuning the environmental humidity or temperature. (paper)

  10. Effect of annealing temperature on the mechanical properties of zircaloy-4 cladding

    International Nuclear Information System (INIS)

    Beauregard, R.J.; Clevinger, G.S.; Murty, K.L.

    1977-01-01

    The mechanical properties of zircaloy cladding materials are sensitive to those fabrication variables which have an effect on the preferred crystallographic orientation or texture of the finished tube. The effect of one such variable, the final annealing temperature, on various mechanical properties is examined using tube reduced zircaloy-4 fuel rod cladding annealed at temperatures from 905F to 1060F. This temperature range provides cladding with varying degrees of recrystallization including full recrystallization. Hoop creep characteristics of zircaloy cladding were studied as a function of the annealing temperature using closed-end internal pressurization tests at 750F and hoop stresses of 10, 15, 20 and 25 ksi. The critical annealing temperature at which a minimum creep strain occurs decreases as the applied stress increases. An additional test at 700F and 30 ksi hoop stress was conducted to demonstrate that the critical annealing temperature is essentially independent of the test temperature. Plausible explanations based on differing substructures developed in cold-worked stress-relieved material are forwarded. The effect of annealing temperature on the room temperature mechanical anisotropy parameters, R and P, was studied. R-parameters were determined from in situ transverse strain gage measurements in uniaxial tensile tests. P-parameters were calculated from uniaxial test data (R and yield stress) and hoop yield stress determined in biaxial, closed-end internal pressurization tests

  11. An analysis of hot plate initial temperature effect on rectangular narrow gap quenching process

    International Nuclear Information System (INIS)

    M-Hadi Kusuma; Mulya Juarsa; Anhar Riza Antariksawan; Nandy Putra

    2012-01-01

    The understanding about thermal management in the event of a severe accident such as the melting nuclear reactor fuel and reactor core, became a priority to maintain the integrity of reactor pressure vessel. Thus the debris will not out from the reactor pressure vessel and resulting impact of more substantial to the environment. One way to maintain the integrity of the reactor pressure vessel was cooling of the excess heat generated due to the accident. To get understanding of this aspect, there search focused on the effect of the initial temperature of the hot plate in the rectangular narrow gap quenching process. The initial temperature effect on quenching process is related to cooling process (thermal management) when the occurrence of a nuclear accident due to loss of coolant accident or severe accident. In order to address the problem, it is crucial to conduct research to get a better understanding of thermal management regarding to nuclear cooling accident. The research focused on determining the rewetting temperature of hot plate cooling on 220°C, 400°C, and 600°C with 0.2 liters/sec cooling water flowrate. Experiments were carried out by injecting 85°C cooling water temperature into the narrow gap at flowrates of 0.2 liters/sec. Data of transient temperature measurements were recorded using a data acquisition system in order to know the rewetting temperature during the quenching process. This study aims to understand the effect of hot plate initial temperature on rewetting during rectangular narrow gap quenching process. The results obtained show that the rewetting point on cooling the hot plate 220°C, 400°C and 600°occurs at varying rewetting temperatures. At 220°C hot plate initial temperature, the rewetting temperature occurs on 220°C. At 400°C hot plate initial temperature, the rewetting temperature occurs on 379.51°C. At 600°C hot plate initial temperature, the rewetting temperature occurs on 426.63°C. Significant differences of hot plate

  12. Effect of kaolin treatment temperature on mortar chloride permeability

    Directory of Open Access Journals (Sweden)

    Puertas, F.

    2007-03-01

    Full Text Available The present paper discusses the results of chloride resistance tests conducted on ordinary Portland cement (OPC mortars containing a Colombian kaolin pre-treated at temperatures of from 600 to 800 ºC. The resulting metakaolin (MK was added to OPC mortar mixes in proportions of 10 and 20% by cement weight. The mortars were compared for physical and chemical properties, including capillary absorption, chloride permeability and pore microstructure as assessed by mercury porosimetry. The best performance was recorded for the samples containing 20% of the material treated at 800 ºC.En el presente trabajo se incluyen los resultados de la resistencia a la penetración de cloruros de morteros de Cemento Portland Ordinario (OPC adicionados con un caolín colombiano sometido a tratamiento térmico en un rango de temperaturas entre 600 y 800 °C. Los productos del tratamiento térmico, metacaolín (MK, son incorporados en mezclas de morteros de OPC en proporciones del 10 y 20% en relación al peso del cemento. Se comparan sus características físico-químicas, entre las cuales se incluye la microestructura de poros evaluada por la técnica de porosimetría de mercurio, con la absorción capilar y la permeabilidad a cloruros. Se concluye que las muestras adicionadas con un 20% del material tratado térmicamente a 800 °C presentan el mejor desempeño en sus propiedades finales.

  13. Effect of solution saturation state and temperature on diopside dissolution

    Directory of Open Access Journals (Sweden)

    Carroll Susan A

    2007-03-01

    Full Text Available Abstract Steady-state dissolution rates of diopside are measured as a function of solution saturation state using a titanium flow-through reactor at pH 7.5 and temperature ranging from 125 to 175°C. Diopside dissolved stoichiometrically under all experimental conditions and rates were not dependent on sample history. At each temperature, rates continuously decreased by two orders of magnitude as equilibrium was approached and did not exhibit a dissolution plateau of constant rates at high degrees of undersaturation. The variation of diopside dissolution rates with solution saturation can be described equally well with a ion exchange model based on transition state theory or pit nucleation model based on crystal growth/dissolution theory from 125 to 175°C. At 175°C, both models over predict dissolution rates by two orders of magnitude indicating that a secondary phase precipitated in the experiments. The ion exchange model assumes the formation of a Si-rich, Mg-deficient precursor complex. Lack of dependence of rates on steady-state aqueous calcium concentration supports the formation of such a complex, which is formed by exchange of protons for magnesium ions at the surface. Fit to the experimental data yields Rate (moldiopsidecm−2s−1=k×10−Ea/2.303RT(aH+2aMg2+n MathType@MTEF@5@5@+=feaafiart1ev1aaatCvAUfKttLearuWrP9MDH5MBPbIqV92AaeXatLxBI9gBaebbnrfifHhDYfgasaacH8akY=wiFfYdH8Gipec8Eeeu0xXdbba9frFj0=OqFfea0dXdd9vqai=hGuQ8kuc9pgc9s8qqaq=dirpe0xb9q8qiLsFr0=vr0=vr0dc8meaabaqaciaacaGaaeqabaqabeGadaaakeaaieaacqWFsbGucqWFHbqycqWF0baDcqWFLbqzcqqGGaaicqGGOaakcqWFTbqBcqWFVbWBcqWFSbaBcqWFGaaicqWFKbazcqWFPbqAcqWFVbWBcqWFWbaCcqWFZbWCcqWFPbqAcqWFKbazcqWFLbqzcqWFGaaicqWFJbWycqWFTbqBdaahaaWcbeqaaiabgkHiTiabikdaYaaakiab=bcaGiab=nhaZnaaCaaaleqabaGaeyOeI0IaeGymaedaaOGaeiykaKIaeyypa0Jaem4AaSMaey41aqRaeeymaeJaeeimaaZaaWbaaSqabeaacqGHsislcqWGfbqrdaWgaaadbaGaemyyaegabeaaliabc+caViabikdaYiabc6caUiabioda

  14. Ameliorative effects of ascorbic acid on rectal temperature ...

    African Journals Online (AJOL)

    Jane

    2011-08-29

    Aug 29, 2011 ... On day 1 post-transportation, the control rabbits lost 2.70% of the pre- transportation ... the adverse effects of stress due to road transportation. Key words: ... Besides, management strate-gies aimed at alleviating stress due to ...

  15. Effects of geometry and temperature on mode I interlaminar fracture ...

    Indian Academy of Sciences (India)

    Administrator

    explanation of the toughening mechanisms were made by comparing the impact properties with ... characteristics of this material are suitable for common ... qualitatively fine dispersion of the nanofiller within the ... may be too small to effectively interact with the propa- ... failure is examined by studying the structural changes.

  16. Main and interaction effects of extrusion temperature and usage ...

    African Journals Online (AJOL)

    ali

    2012-10-30

    Oct 30, 2012 ... The main and interaction effects of three extrusion ... oil extraction and allow the use of a homegrown protein supplement in the .... Statistical analysis. The main and .... acceptable level of antitrypsin factor is 4 mg/g; this level.

  17. Halogen effect for improving high temperature oxidation resistance of Ti-50Al by anodization

    Science.gov (United States)

    Mo, Min-Hua; Wu, Lian-Kui; Cao, Hua-Zhen; Lin, Jun-Pin; Zheng, Guo-Qu

    2017-06-01

    The high temperature oxidation resistance of Ti-50Al was significantly improved via halogen effect which was achieved by anodizing in an ethylene glycol solution containing with fluorine ion. The anodized Ti-50Al with holes and micro-cracks could be self-repaired during oxidation at 1000 °C. The thickness of the oxide scale increases with the prolonging of oxidation time. On the basis of halogen effect for improving the high temperature oxidation resistance of Ti-50Al by anodization, only fluorine addition into the electrolyte can effectively improve the high temperature oxidation resistance of Ti-50Al.

  18. Modeling of Temperature Effect on Modal Frequency of Concrete Beam Based on Field Monitoring Data

    Directory of Open Access Journals (Sweden)

    Wenchen Shan

    2018-01-01

    Full Text Available Temperature variation has been widely demonstrated to produce significant effect on modal frequencies that even exceed the effect of actual damage. In order to eliminate the temperature effect on modal frequency, an effective method is to construct quantitative models which accurately predict the modal frequency corresponding to temperature variation. In this paper, principal component analysis (PCA is conducted on the temperatures taken from all embedded thermocouples for extracting input parameters of regression models. Three regression-based numerical models using multiple linear regression (MLR, back-propagation neural network (BPNN, and support vector regression (SVR techniques are constructed to capture the relationships between modal frequencies and temperature distributions from measurements of a concrete beam during a period of forty days of monitoring. A comparison with respect to the performance of various optimally configured regression models has been performed on measurement data. Results indicate that the SVR exhibits a better reproduction and prediction capability than BPNN and MLR models for predicting the modal frequencies with respect to nonuniformly distributed temperatures. It is succeeded that temperature effects on modal frequencies can be effectively eliminated based on the optimally formulated SVR model.

  19. Chemotaxis in the cellular slime molds : I. The effect of temperature

    NARCIS (Netherlands)

    Konijn, Theo M.

    1965-01-01

    The effect of temperature on chemotaxis in the cellular slime mold Dictyostelium discoideum has been studied by incubating small populations of washed myxamoebae at different temperatures. Droplets containing a cell suspension of known density were deposited on a hydrophobic agar surface. The

  20. Effect of semen extender and storage temperature on ram sperm motility over time

    Science.gov (United States)

    Storage of ram semen for long period of time depends on a number of factors, including type of extender and storage temperature. A study compared the effect of semen extender and storage temperature on motility of ram semen stored for 72 h. Semen collected via electroejaculator from 5 mature Katahd...

  1. Effects of wildfire on stream temperatures in the Bitterroot River basin, Montana

    Science.gov (United States)

    Shad K. Mahlum; Lisa A. Eby; Michael K. Young; Chris G. Clancy; Mike Jakober

    2011-01-01

    Wildfire is a common natural disturbance that can influence stream ecosystems. Of particular concern are increases in water temperature during and following fires, but studies of these phenomena are uncommon. We examined effects of wildfires in 2000 on maximum water temperature for a suite of second- to fourth-order streams with a range of burn severities in the...

  2. Effect of environmental temperature on the vector competence of mosquitoes for Rift Valley fever virus

    Science.gov (United States)

    Environmental temperature has been shown to affect the ability of mosquitoes to transmit numerous arboviruses and for Rift Valley fever virus (RVFV) in particular. We evaluated the effect of incubation temperatures ranging from 14-26ºC on infection, dissemination, and transmission rates for Culex ta...

  3. Measurement of the temperature Gradient in air using Talbot effect and Moire technique

    International Nuclear Information System (INIS)

    Tavassoly, M.T.; Rasouli, S.

    2000-01-01

    In this paper we have exploited the self-imaging or Talbot effect and Moire technique to measure the temperature distribution in the air enclosed between two paral led plates of different temperatures. This study shows that for the plates width of 60 cm a change of 1 d egC in 1 cm can be easily detected

  4. Evaluation of the effect of temperature on the stability of metal soaps ...

    African Journals Online (AJOL)

    The thermal stability of calcium and zinc dicarboxylates was studied. The kinetics of the decomposition was studied thermogravimetrically at various temperatures. The rates of the first stage decomposition were used to assess the effect of temperature on the susceptibility of the metal soaps of dicarboxylic acids to ...

  5. Effective temperature of an ultracold electron source based on near-threshold photoionization

    NARCIS (Netherlands)

    Engelen, W.J.; Smakman, E.P.; Bakker, D.J.; Luiten, O.J.; Vredenbregt, E.J.D.

    2014-01-01

    We present a detailed description of measurements of the effective temperature of a pulsed electron source, based on near-threshold photoionization of laser-cooled atoms. The temperature is determined by electron beam waist scans, source size measurements with ion beams, and analysis with an

  6. Effects of Different Environment Temperatures on Some Motor Characteristics and Muscle Strength

    Science.gov (United States)

    Çakir, Ergün; Yüksek, Selami; Asma, Bülent; Arslanoglu, Erkal

    2016-01-01

    The aim of this study was determine the effects of different environment temperatures on motor characteristics and muscle strength. 15 athletes participated to study. Flexibility, vertical jump, hand grip-leg strength, 30m sprint, 20-meter shuttle run and coordination-agility tests were measured in five different environment temperatures. (22°C,…

  7. Mathematical modeling of photoinitiated coating degradation: Effects of coating glass transition temperature and light stabilizers

    DEFF Research Database (Denmark)

    Kiil, Søren; G.de With, R.A.T.M.Van Benthem

    2013-01-01

    A mathematical model, describing coating degradation mechanisms of thermoset coatings exposed to ultraviolet radiation and humidity at constant temperature, was extended to simulate the behavior of a coating with a low glass transition temperature. The effects of adding light stabilizers (a UV...

  8. Temperature sensitivity analysis of polarity controlled electrostatically doped tunnel field-effect transistor

    Science.gov (United States)

    Nigam, Kaushal; Pandey, Sunil; Kondekar, P. N.; Sharma, Dheeraj

    2016-09-01

    The conventional tunnel field-effect transistors (TFETs) have shown potential to scale down in sub-22 nm regime due to its lower sub-threshold slope and robustness against short-channel effects (SCEs), however, sensitivity towards temperature variation is a major concern. Therefore, for the first time, we investigate temperature sensitivity analysis of a polarity controlled electrostatically doped tunnel field-effect transistor (ED-TFET). Different performance metrics and analog/RF figure-of-merits were considered and compared for both devices, and simulations were performed using Silvaco ATLAS device tool. We found that the variation in ON-state current in ED-TFET is almost temperature independent due to electrostatically doped mechanism, while, it increases in conventional TFET at higher temperature. Above room temperature, the variation in ION, IOFF, and SS sensitivity in ED-TFET are only 0.11%/K, 2.21%/K, and 0.63%/K, while, in conventional TFET the variations are 0.43%/K, 2.99%/K, and 0.71%/K, respectively. However, below room temperature, the variation in ED-TFET ION is 0.195%/K compared to 0.27%/K of conventional TFET. Moreover, it is analysed that the incomplete ionization effect in conventional TFET severely affects the drive current and the threshold voltage, while, ED-TFET remains unaffected. Hence, the proposed ED-TFET is less sensitive towards temperature variation and can be used for cryogenics as well as for high temperature applications.

  9. Effect of the annealing temperature for the hydrogen Q-degradation on superconducting cavities

    International Nuclear Information System (INIS)

    Ota, Tomoko; Sukenobu, Satoru; Tanabe, Yoshio; Onishi, Yoshimichi; Noguchi, Shuichi; Ono, Masaaki; Saito, Kenji; Shishido, Toshio; Yamazaki, Yoshishige

    1997-01-01

    Hydrogen Q-degradation was studied in niobium superconducting cavities prepared by barrel polishing, and electropolishing without annealing, though a fast cooling down of cavities. Cavity performance with various annealing temperature were tested using a 1.3GHz single-cell cavity to compare the effects of annealing temperature for hydrogen Q-degradation. (author)

  10. The interacting effects of temperature and food chain length on trophic abundance and ecosystem function.

    Science.gov (United States)

    Beveridge, Oliver S; Humphries, Stuart; Petchey, Owen L

    2010-05-01

    1. While much is known about the independent effects of trophic structure and temperature on density and ecosystem processes, less is known about the interaction(s) between the two. 2. We manipulated the temperature of laboratory-based bacteria-protist communities that contained communities with one, two, or three trophic levels, and recorded species' densities and bacterial decomposition. 3. Temperature, food chain length and their interaction produced significant responses in microbial density and bacterial decomposition. Prey and resource density expressed different patterns of temperature dependency during different phases of population dynamics. The addition of a predator altered the temperature-density relationship of prey, from a unimodal trend to a negative one. Bacterial decomposition was greatest in the presence of consumers at higher temperatures. 4. These results are qualitatively consistent with a recent model of direct and indirect temperature effects on resource-consumer population dynamics. Results highlight and reinforce the importance of indirect effects of temperature mediated through trophic interactions. Understanding and predicting the consequences of environmental change will require that indirect effects, trophic structure, and individual species' tolerances be incorporated into theory and models.

  11. The effect of ambient temperature on gross-efficiency in cycling

    NARCIS (Netherlands)

    Hettinga, F.J.; Koning, J.J. de; Vrijer, A. de; Wüst, R.C.I.; Daanen, H.A.M.; Foster, C.

    2007-01-01

    Time-trial performance deteriorates in the heat. This might potentially be the result of a temperature-induced decrease in gross-efficiency (GE). The effect of high ambient temperature on GE during cycling will be studied, with the intent of determining if a heat-induced change in GE could account

  12. Effects of whole body cryotherapy and cold water immersion on knee skin temperature

    OpenAIRE

    Costello, J. T.; Donnelly, A. E.; Karki, A.; Selfe, J.

    2014-01-01

    This study sought to a) compare and contrast the effect of 2 commonly used cryotherapy treatments, 4 min of −110°C whole body cryotherapy and 8°C cold water immersion, on knee skin temperature and b) establish whether either protocol was capable of achieving a skin temperature (

  13. Effect of temperature upon the fatigue-crack propagation behavior of Inconel X-750

    International Nuclear Information System (INIS)

    James, L.A.

    1976-05-01

    The techniques of linear-elastic fracture mechanics were employed to characterize the effect of temperature upon the fatigue-crack propagation behavior of precipitation heat-treated Inconel X-750 in an air environment over the range 75-1200 0 F. In general, fatigue-crack growth rates increased with increasing test temperature

  14. Effect of cellulose fiber reinforcement on the temperature dependent mechanical performance of nylon 6

    Science.gov (United States)

    Mehdi Tajvidi; Mokhtar Feizmand; Robert H. Falk; Colin Felton

    2009-01-01

    In order to quantify the effect of temperature on the mechanical properties of pure nylon 6 and its composite with cellulose fibers (containing 25 wt% cellulose fibers), the materials were sampled and tested at three representative temperatures of 256, 296, and 336 K. Flexural and tensile tests were performed and the reductions in mechanical properties were evaluated....

  15. Quantification of the effect of hysteresis on the adiabatic temperature change in magnetocaloric materials

    DEFF Research Database (Denmark)

    von Moos, Lars; Bahl, Christian R.H.; Nielsen, Kaspar Kirstein

    2014-01-01

    description of the phase transition at varying magnetic fields and temperatures. Using detailed experimental property data, a Preisach type model is used to describe the thermal hysteresis effects and simulate the material under realistic working conditions. We find that the adiabatic temperature change...

  16. Temperature effects in exchange-biased planar Hall sensors for bioapplications

    DEFF Research Database (Denmark)

    Damsgaard, Christian Danvad; Dalslet, Bjarke Thomas; Freitas, S.C.

    2009-01-01

    The temperature dependence of exchange biased planar Hall effect sensors is investigated between T = −10 and 70 °C. It is shown that a single domain model describes the system well and that the temperature coefficient of the low-field sensitivity at T = 25 °C is 0.32%/°C. A procedure for temperat...

  17. The effect of skin temperature on performance during a 7.5-km cycling time trial

    NARCIS (Netherlands)

    Levels, K.; de Koning, J.J.; Foster Jr., C.C.; Daanen, H.A.M.

    2012-01-01

    Aerobic exercise performance is seriously compromised in the heat. Possibly, a high skin temperature causes a rating of perceived exertion (RPE)-mediated decrease in exercise intensity. The purpose of this study was to determine the effect of skin temperature on power output during a 7.5-km cycling

  18. Effects of dissolution medium, pH and temperature on the in vitro ...

    African Journals Online (AJOL)

    Similarly, disssolution studies were carrtied out at varying temperatures to determine the effect of temperature onn release and disintegration. Results obtained showed that the tablets possessed officailly acceptable hardness, uniformity of weight, and absolute drug content, but a high friablity. The drugs were released faster ...

  19. Effect of temperature on Acoustic Evaluation of standing trees and logs: Part 2: Field Investigation

    Science.gov (United States)

    Shan Gao; Xiping Wang; Lihai Wang; R. Bruce Allison

    2013-01-01

    The objectives of this study were to investigate the effect of seasonal temperature changes on acoustic velocity measured on standing trees and green logs and to develop models for compensating temperature differences because acoustic measurements are performed in different climates and seasons. Field testing was conducted on 20 red pine (Pinus resinosa...

  20. The finite-temperature Gaussian effective potential from a variational principle

    International Nuclear Information System (INIS)

    Haugerud, H.; Ravndal, F.

    1990-08-01

    Writing the partition function for a scalar quantum field theory as a functional integral, it follows that the finite-temperature Gaussian effective potential is an upper limit to the free energy of the system. Explicit results are given for the anharmonic oscillator at finite temperature. 5 refs., 2 figs