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Sample records for heat capacity measurement

  1. MEASUREMENT OF SPECIFIC HEAT CAPACITY OF SALTSTONE

    Energy Technology Data Exchange (ETDEWEB)

    Harbour, J; Vickie Williams, V

    2008-09-29

    One of the goals of the Saltstone variability study is to identify (and quantify the impact of) the operational and compositional variables that control or influence the important processing and performance properties of Saltstone grout mixtures. The heat capacity of the Saltstone waste form is one of the important properties of Saltstone mixes that was last measured at SRNL in 1997. It is therefore important to develop a core competency for rapid and accurate analysis of the specific heat capacity of the Saltstone mixes in order to quantify the impact of compositional and operational variations on this property as part of the variability study. The heat capacity, coupled with the heat of hydration data obtained from isothermal calorimetry for a given Saltstone mix, can be used to predict the maximum temperature increase in the cells within the vaults of the Saltstone Disposal Facility (SDF). The temperature increase controls the processing rate and the pour schedule. The maximum temperature is also important to the performance properties of the Saltstone. For example, in mass pours of concrete or grout of which Saltstone is an example, the maximum temperature increase and the maximum temperature difference (between the surface and the hottest location) are controlled to ensure durability of the product and prevent or limit the cracking caused by the thermal gradients produced during curing. This report details the development and implementation of a method for the measurement of the heat capacities of Saltstone mixes as well as the heat capacities of the cementitious materials of the premix and the simulated salt solutions used to batch the mixes. The developed method utilizes the TAM Air isothermal calorimeter and takes advantage of the sophisticated heat flow measurement capabilities of the instrument. Standards and reference materials were identified and used to validate the procedure and ensure accuracy of testing. Heat capacities of Saltstone mixes were

  2. How to Measure Heat Capacity at Low Temperatures

    Science.gov (United States)

    Ventura, Guglielmo; Perfetti, Mauro

    This chapter is devoted to the description of calorimetric techniques used to measure heat capacity of solids: pulse heat calorimetry (Sect. 2.3), relaxation calorimetry (Sect. 2.4), dual slope calorimetry (Sect. 2.5), a.c. calorimetry (Sect. 2.6), differential scanning calorimetry (Sect. 2.7). Examples of measurements of heat capacity are reported in Sects. 2.3 and 2.4.

  3. Device for Measuring Heat Capacities of Microcalorimeter Absorber Materials

    Science.gov (United States)

    Kotsubo, Vincent; Beall, James; Ullom, Joel

    2009-12-01

    We are developing a device for measuring the heat capacity of candidate absorber materials for gamma-ray microcalorimeters with the goal of finding materials with low heat capacity and high stopping power to improve detector efficiency. To date, only Sn has been effective as an absorber, and speculation is that other materials suffer from anomalously high heat capacities at low temperatures. The key component of the measurement device is a 17 mm×17 mm low heat capacity silicon platform suspended by Kevlar fibers designed for accepting 1 g to 2 g samples, and whose heat capacity can be characterized prior to attaching a sample. The platform has a thin film Pd/Au heater deposited directly on the silicon, and a semiconducting thermometer bonded to the surface. The heat capacity is determined from C = Gτ, where G is the in-situ measured conductance and x is the measured temperature decay time from a step change in applied heat. For a platform without samples, decay periods on the order of 0.3 to 0.05 seconds were measured. With samples, decay periods of several seconds are projected, allowing good resolution of the heat capacities. Several thermometers were tested in an effort to find one with the optimum characteristics for measuring platform temperatures. These included a commercial thick-film Ruthenium-oxide surface-mount resistor, a germanium NTD, and a zirconium oxy-nitride thin-film thermometer.

  4. Heat-capacity measurements on small samples: The hybrid method

    NARCIS (Netherlands)

    Klaasse, J.C.P.; Brück, E.H.

    2008-01-01

    A newly developed method is presented for measuring heat capacities on small samples, particularly where thermal isolation is not sufficient for the use of the traditional semiadiabatic heat-pulse technique. This "hybrid technique" is a modification of this heat-pulse method in case the temperature

  5. Measurement of the specific heat capacity of graphite

    Energy Technology Data Exchange (ETDEWEB)

    Picard, S.; Burns, D.T.; Roger, P

    2006-01-15

    With the objective of implementing graphite calorimetry at the BIPM to measure absorbed dose, an experimental assembly has recently been constructed to measure the specific heat capacity of graphite. A status description of the apparatus and results from the first measurements are given. The outcome is discussed and the experimental uncertainty is reviewed. (authors)

  6. Heat capacity measurements on high T sub c superconductors

    CERN Document Server

    Oezcan, S

    1998-01-01

    temperature interval. The phase transition jump increases with the increasing of oxygen amount in the CuO sub 2 layers. The hight of the jump is varying from 1.5% to 3.5% of the total specific heat which is the nature of the bulk superconductivity. The small coherence length increases fluctuation effects and also causes the dependence of superconducting properties on structural defects. The fluctuation effects on the heat capacity of YBCO is investigated on the sample that shows clear superconducting properties. In this work, a heat capacity measurement system which has high sensitivity and reproducibility designed and constructed. The investigation of the effect of oxygen stoichiometry on the superconducting properties of high T sub c superconductors was aimed. For this purpose electrical resistivity, magnetic susceptibility and heat capacity experiment were performed. The constructed system is a computerized adiabatic calorimeter which has temperature resolution of about 0.1 mk and operates in the temperatu...

  7. An automated flow calorimeter for heat capacity and enthalpy measurements

    Energy Technology Data Exchange (ETDEWEB)

    Sandarusi, J.A.; Yesavage, V.F.

    1988-11-01

    An automated flow calorimeter has been developed for the measurement of heat capacity and latent enthalpies of fluids at elevated temperatures (300-700 K) and pressure (< 30 MPa) with a design accuracy of 0.1%. The method of measurement is the traditional electrical power input flow calorimeter, utilizing a precision metering pump, which eliminates the need for flow-rate monitoring. The calorimeter cell uses a unique concentric coil design with passive metal radiation shields and active guard heaters to minimize heat leakage, eliminate the traditional constant-temperature bath, and facilitate easy component replacement. An additional feature of the instrument is a complete automation system, greatly simplifying operation of the apparatus. A novel multitasking software scheme allows a single microcomputer simultaneously to control all system temperatures, provide continuous monitoring and updates on system status, and log data. Preliminary results for liquid water mean heat capacities show the equipment to be performing satisfactorily, with data accuracies of better than /plus minus/0.3%. Minor equipment modifications and better thermometry are required to reduce systemic errors and to achieve the designed operational range.

  8. Thermodynamics of micellization from heat-capacity measurements.

    Science.gov (United States)

    Šarac, Bojan; Bešter-Rogač, Marija; Lah, Jurij

    2014-06-23

    Differential scanning calorimetry (DSC), the most important technique for studying the thermodynamics of structural transitions of biological macromolecules, is seldom used in quantitative thermodynamic studies of surfactant micellization/demicellization. The reason for this could be ascribed to an insufficient understanding of the temperature dependence of the heat capacity of surfactant solutions (DSC data) in terms of thermodynamics, which leads to problems with the design of experiments and interpretation of the output signals. We address these issues by careful design of DSC experiments performed with solutions of ionic and nonionic surfactants at various surfactant concentrations, and individual and global mass-action model analysis of the obtained DSC data. Our approach leads to reliable thermodynamic parameters of micellization for all types of surfactants, comparable with those obtained by using isothermal titration calorimetry (ITC). In summary, we demonstrate that DSC can be successfully used as an independent method to obtain temperature-dependent thermodynamic parameters for micellization. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Measurement and Model Validation of Nanofluid Specific Heat Capacity with Differential Scanning Calorimetry

    Directory of Open Access Journals (Sweden)

    Harry O'Hanley

    2012-01-01

    Full Text Available Nanofluids are being considered for heat transfer applications; therefore it is important to know their thermophysical properties accurately. In this paper we focused on nanofluid specific heat capacity. Currently, there exist two models to predict a nanofluid specific heat capacity as a function of nanoparticle concentration and material. Model I is a straight volume-weighted average; Model II is based on the assumption of thermal equilibrium between the particles and the surrounding fluid. These two models give significantly different predictions for a given system. Using differential scanning calorimetry (DSC, a robust experimental methodology for measuring the heat capacity of fluids, the specific heat capacities of water-based silica, alumina, and copper oxide nanofluids were measured. Nanoparticle concentrations were varied between 5 wt% and 50 wt%. Test results were found to be in excellent agreement with Model II, while the predictions of Model I deviated very significantly from the data. Therefore, Model II is recommended for nanofluids.

  10. Measurements of thermal diffusivity, specific heat capacity and thermal conductivity with LFA 447 apparatus

    DEFF Research Database (Denmark)

    Zajas, Jan Jakub; Heiselberg, Per

    The LFA 447 can be successfully used for measurements of thermal diffusivity, specific heat and thermal conductivity of various samples. It is especially useful when determining the properties of materials on a very small scale. The matrix measurement mode allows for determining the local...... properties with a fine resolution, down to 1 millimeter. Special attention needs to be taken when determining the specific heat capacity in the comparative method. First of all, the test and reference sample should be of nearly identical thickness. Secondly, their heat diffusion time should be comparable, so...... that the heat losses from both samples during the measurement are similar. Finally, the leveling of the samples is very important. Very small discrepancies can cause a massive error in the derivation of specific heat capacity and, as a result, thermal conductivity....

  11. Heat capacity measurements of sub-nanoliter volumes of liquids using bimaterial microchannel cantilevers

    Energy Technology Data Exchange (ETDEWEB)

    Khan, M. F.; Miriyala, N.; Hassanpourfard, M.; Thundat, T. [Ingenuity Lab, Edmonton, Alberta T6G 2R3 (Canada); Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta T6G 2R3 (Canada); Lee, J. [Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta T6G 2R3 (Canada); Department of Mechanical Engineering, Sogang University, 121-742 Seoul (Korea, Republic of); Kumar, A. [Department of Mechanical Engineering, University of Alberta, Edmonton, Alberta T6G 2R3 (Canada)

    2016-05-23

    Lab-on-a-Chip compatible techniques for thermal characterization of miniaturized volumes of liquid analytes are necessary in applications such as protein blotting, DNA melting, and drug development, where samples are either rare or volume-limited. We developed a closed-chamber calorimeter based on a bimaterial microchannel cantilever (BMC) for sub-nanoliter level thermal analysis. When the liquid-filled BMC is irradiated with infrared (IR) light at a specific wavelength, the IR absorption by the liquid analyte results in localized heat generation and the subsequent deflection of the BMC, due to a thermal expansion mismatch between the constituent materials. The time constant of the deflection, which is dependent upon the heat capacity of the liquid analyte, can be directly measured by recording the time-dependent bending of the BMC. We have used the BMC to quantitatively measure the heat capacity of five volatile organic compounds. With a deflection noise level of ∼10 nm and a signal-to-noise ratio of 68:1, the BMC offers a sensitivity of 30.5 ms/(J g{sup −1 }K{sup −1}) and a resolution of 23 mJ/(g K) for ∼150 pl liquid for heat capacity measurements. This technique can be used for small-scale thermal characterization of different chemical and biological samples.

  12. Heat Capacity Measurements of Sr2RuO4 Under Uni-axial Stress

    Science.gov (United States)

    Li, You-Sheng; Gibbs, Alexandra; MacKenzie, Andrew; Hicks, Clifford; Nicklas, Michael

    One of the most-discussed possible pairing symmetries of the superconductor Sr2RuO4 is px + /-ipy. By applying in-plane uniaxial stress, the degeneracy of the px and py components should be lifted, yielding two critical temperatures (Tc) . Hicks et al. observed an increase of Tc of Sr2RuO4 under both compressive and tensile stress, and did not find evidence for splitting of transition. However, that result was based on magnetic susceptibility measurements, which would be sensitive only to the upper transition. For a direct test of possible splitting, we measure the heat capacity of Sr2RuO4 under uniaxial stress. To do so, we have developed an approach to measure heat capacity under non-adiabatic conditions. We have observed the increase in Tc under compressive strain, providing the first thermodynamic evidence for the strain-induced increase in Tc of Sr2RuO4, and also resolve strong strain-induced changes in the normal-state heat capacity.

  13. Cryostat for semiautomatic measurement of heat capacity and elastic moduli between 1.6 and 400 K

    Science.gov (United States)

    Hirao, Kazuyuki; Soga, Naohiro

    1983-11-01

    An adiabatic cryostat system for the measurement of either heat capacity or elastic moduli was constructed. The vacuum system, electronic equipment to achieve the adiabatic conditions, and instruments for measurements are described. The cube resonance method used for measurement of elastic moduli is shown. Test measurements on the heat capacity of α-Al2O3 show agreement within ±1% of the literature values. The results of heat capacity and elastic moduli measurements on optical fiberglass are described and compared with other data.

  14. Electrolytic conductivity and molar heat capacity of two aqueous solutions of ionic liquids at room-temperature: Measurements and correlations

    Energy Technology Data Exchange (ETDEWEB)

    Lin Peiyin [R and D Center for Membrane Technology and Department of Chemical Engineering, Chung Yuan Christian University, Chung Li 32023, Taiwan (China); Soriano, Allan N. [R and D Center for Membrane Technology and Department of Chemical Engineering, Chung Yuan Christian University, Chung Li 32023, Taiwan (China); School of Chemical Engineering and Chemistry, Mapua Institute of Technology, Manila 1002 (Philippines); Leron, Rhoda B. [R and D Center for Membrane Technology and Department of Chemical Engineering, Chung Yuan Christian University, Chung Li 32023, Taiwan (China); Li Menghui, E-mail: mhli@cycu.edu.t [R and D Center for Membrane Technology and Department of Chemical Engineering, Chung Yuan Christian University, Chung Li 32023, Taiwan (China)

    2010-08-15

    As part of our systematic study on physicochemical characterization of ionic liquids, in this work, we report new measurements of electrolytic conductivity and molar heat capacity for aqueous solutions of two 1-ethyl-3-methylimidazolium-based ionic liquids, namely: 1-ethyl-3-methylimidazolium dicyanamide and 1-ethyl-3-methylimidazolium 2-(2-methoxyethoxy) ethylsulfate, at normal atmospheric condition and for temperatures up to 353.2 K. The electrolytic conductivity and molar heat capacity were measured by a commercial conductivity meter and a differential scanning calorimeter (DSC), respectively. The estimated experimental uncertainties for the electrolytic conductivity and molar heat capacity measurements were {+-}1% and {+-}2%, respectively. The property data are reported as functions of temperature and composition. A modified empirical equation from another researcher was used to correlate the temperature and composition dependence of the our electrolytic conductivity results. An excess molar heat capacity expression derived using a Redlich-Kister type equation was used to represent the temperature and composition dependence of the measured molar heat capacity and calculated excess molar heat capacity of the solvent systems considered. The correlations applied represent the our measurements satisfactorily as shown by an acceptable overall average deviation of 6.4% and 0.1%, respectively, for electrolytic conductivity and molar heat capacity.

  15. An automated flow calorimeter for heat capacity and enthalpy measurements at elevated temperatures and pressures

    Energy Technology Data Exchange (ETDEWEB)

    Yesavage, V.F.

    1990-08-31

    The need for highly accurate thermal property data for a broad range of new application fluids is well documented. To facilitate expansion of the current thermophysical database, an automated flow calorimeter was developed for the measurement of highly accurate isobaric heat capacities and enthalpies of fluids at elevated temperatures and pressures. The experimental technique utilizes traditional electrical power input, adiabatic flow calorimetry with a precision metering pump that eliminates the need for on-line flow rate monitoring. In addition, a complete automation system, greatly simplifies the operation of the apparatus and increases the rapidity of the measurement process. The range over which the instrument was tested, was 300--600 K and 0--12 Mpa, although the calorimeter should perform up to the original design goals of 700 K and 30 MPa. The new flow calorimeter was evaluated by measuring the mean, isobaric, specific heat capacities of liquid water and n-pentane. These experiments yielded an average deviation from the standard literature data of +0.02% and a total variation of 0.05%. Additional data analysis indicated that the overall measurement uncertainty was conservatively estimated as 0.2% with an anticipated precision of 0.1--0.15% at all operating conditions. 44 refs., 27 figs., 2 tabs.

  16. Heat capacity measurements of atoms and molecules adsorbed on evaporated metal films

    Energy Technology Data Exchange (ETDEWEB)

    Kenny, T.W.

    1989-05-01

    Investigations of the properties of absorbed monolayers have received great experimental and theoretical attention recently, both because of the importance of surface processes in practical applications such as catalysis, and the importance of such systems to the understanding of the fundamentals of thermodynamics in two dimensions. We have adapted the composite bolometer technology to the construction of microcalorimeters. For these calorimeters, the adsorption substrate is an evaporated film deposited on one surface of an optically polished sapphire wafer. This approach has allowed us to make the first measurements of the heat capacity of submonolayer films of /sup 4/He adsorbed on metallic films. In contrast to measurements of /sup 4/He adsorbed on all other insulating substrates, we have shown that /sup 4/He on silver films occupies a two-dimensional gas phase over a broad range of coverages and temperatures. Our apparatus has been used to study the heat capacity of Indium flakes. CO multilayers, /sup 4/He adsorbed on sapphire and on Ag films and H/sub 2/ adsorbed on Ag films. The results are compared with appropriate theories. 68 refs., 19 figs.

  17. Measurement uncertainties when determining heat rate, isentropic efficiency and swallowing capacity

    Energy Technology Data Exchange (ETDEWEB)

    Snygg, U.

    1996-05-01

    The objective of the project was to determine the uncertainties when calculating heat rate, isentropic efficiencies and swallowing capacities of power plants. Normally when a power plant is constructed, the supplier also guarantee some performance values, e.g. heat rate. When the plant is built and running under normal conditions, an evaluation is done and the guarantee values are checked. Different measured parameters influence the calculated value differently, and therefore a sensitivity factor can be defined as the sensitivity of a calculated value when the measured value is changing. The product of this factor and the uncertainty of the measured parameter gives an error of the calculated value. For every measured parameter, the above given factor has to be determined and then the root square sum gives the overall uncertainty of the calculated parameter. To receive acceptable data during the evaluation of the plant, a test code is to be followed. The test code also gives guidelines how big the errors of the measurements are. In this study, ASME PTC6 and DIN 1943 were used. The results show that not only the test code was of vital importance, but also the distribution of the power output of the HP-IP turbines contra LP turbines. A higher inlet pressure of the LP turbine gives a smaller uncertainty of the isentropic efficiency. An increase from 6 to 13 bar will lower the uncertainty 1.5 times. 10 refs, 24 figs, 23 tabs, 5 appendixes

  18. Simultaneous measurement of thermal conductivity and heat capacity by flash thermal imaging methods

    Science.gov (United States)

    Tao, N.; Li, X. L.; Sun, J. G.

    2017-06-01

    Thermal properties are important for material applications involved with temperature. Although many measurement methods are available, they may not be convenient to use or have not been demonstrated suitable for testing of a wide range of materials. To address this issue, we developed a new method for the nondestructive measurement of the thermal effusivity of bulk materials with uniform property. This method is based on the pulsed thermal imaging-multilayer analysis (PTI-MLA) method that has been commonly used for testing of coating materials. Because the test sample for PTI-MLA has to be in a two-layer configuration, we have found a commonly used commercial tape to construct such test samples with the tape as the first-layer material and the bulk material as the substrate. This method was evaluated for testing of six selected solid materials with a wide range of thermal properties covering most engineering materials. To determine both thermal conductivity and heat capacity, we also measured the thermal diffusivity of these six materials by the well-established flash method using the same experimental instruments with a different system setup. This paper provides a description of these methods, presents detailed experimental tests and data analyses, and discusses measurement results and their comparison with literature values.

  19. Frequency-dependent heat capacity

    DEFF Research Database (Denmark)

    Behrens, Claus Flensted

    The frequency–dependent heat capacity of super-cooled glycerol near the glass transition is measured using the 3w detection technique. An electrical conducting thin film with a temperature–dependent electrical resistance is deposited on a substrate. The thin film is used simultaneously as a heater...

  20. On the Specific Heat Capacity of CuO Nanofluid

    OpenAIRE

    Le-Ping Zhou; Bu-Xuan Wang; Xiao-Feng Peng; Xiao-Ze Du; Yong-Ping Yang

    2010-01-01

    This paper reviews briefly the definition of heat capacity and clarifies the defined specific heat capacity and volumetric heat capacity. The specific heat capacity and volumetric heat capacity, with our measured experimental data for CuO nanofluids, are discussed as an illustrating example. The result indicates that the specific heat capacity of CuO nanofluid decreases gradually with increasing volume concentration of nanoparticles. The measurement and the prediction from the thermal equilib...

  1. Laser Measurement of the Speed of Sound in Gases: A Novel Approach to Determining Heat Capacity Ratios and Gas Composition

    Science.gov (United States)

    Baum, J. Clayton; Compton, R. N.; Feigerle, Charles S.

    2008-01-01

    The speed of sound is measured in several gases using a pulsed laser to create a micro-spark on a carbon rod and a microphone connected to a digital oscilloscope to measure the time-of-flight of the resulting shockwave over a known distance. These data are used to calculate the heat capacity ratios (C[subscript p]/C[subscript V]) of the gases and…

  2. Heat capacity and heat of dissociation of methane hydrates

    Energy Technology Data Exchange (ETDEWEB)

    Rueff, R.M.; Sloan, E.D.; Yesavage, V.F.

    1988-09-01

    The objective of this study was to determine the heat capacity and heat of dissociation of methane hydrates. A technique has been devised which circumvents the two major problems encountered in measuring gas hydrate heat capacity: the need to impose a mechanical pressure during the measurement and the need to have an absolutely pure hydrate sample. The technique was shown to be successful utilizing high-pressure, constant-volume cells in a differential scanning calorimeter.

  3. Heat capacity measurements of Sr{sub 2}RuO{sub 4} under uni-axial strain

    Energy Technology Data Exchange (ETDEWEB)

    Li, You-sheng; Mackenzie, Andrew [Max Planck Institute for Chemical Physics of Solids, Dresden (Germany); University of St. Andrews, School of Physics and Astronomy (United Kingdom); Gibbs, Alexandra [Max Planck Institute for Solid State Research, Stuttgart (Germany); Hicks, Clifford [Max Planck Institute for Chemical Physics of Solids, Dresden (Germany); Nicklas, Michael [University of St. Andrews, School of Physics and Astronomy (United Kingdom)

    2016-07-01

    One of the most-discussed possible pairing symmetries of Sr{sub 2}RuO{sub 4} is p{sub x} ± ip{sub y}. By applying strain along left angle 100 right angle -direction, the degeneracy of the p{sub x} and p{sub y} components is lifted, and thus there should be two critical temperatures (T{sub c}). Hicks et al. have observed an increase of T{sub c} of Sr{sub 2}RuO{sub 4} under both compressive and tensile strains, by measuring the susceptibility, which is sensitive only to the first transition. Their results also indicate, indirectly, that any splitting of T{sub c}s might be small. For a direct test of possible splitting, we measure the heat capacity of Sr{sub 2}RuO{sub 4} under strain. To do so, we are developing an approach to measure heat capacity under non-adiabatic conditions. We have observed an increase of T{sub c} under compressive strain. This is the first thermodynamic evidence of the strain-induced increase in T{sub c} of Sr{sub 2}RuO{sub 4}.

  4. Measurement of the Electronic Thermal Conductance Channels and Heat Capacity of Graphene at Low Temperature

    Directory of Open Access Journals (Sweden)

    Kin Chung Fong

    2013-10-01

    Full Text Available The ability to transport energy is a fundamental property of the two-dimensional Dirac fermions in graphene. Electronic thermal transport in this system is relatively unexplored and is expected to show unique fundamental properties and to play an important role in future applications of graphene, including optoelectronics, plasmonics, and ultrasensitive bolometry. Here, we present measurements of bipolar thermal conductances due to electron diffusion and electron-phonon coupling and infer the electronic specific heat, with a minimum value of 10k_{B} (10^{-22}  J/K per square micron. We test the validity of the Wiedemann-Franz law and find that the Lorenz number equals 1.32×(π^{2}/3(k_{B}/e^{2}. The electron-phonon thermal conductance has a temperature power law T^{2} at high doping levels, and the coupling parameter is consistent with recent theory, indicating its enhancement by impurity scattering. We demonstrate control of the thermal conductance by electrical gating and by suppressing the diffusion channel using NbTiN superconducting electrodes, which sets the stage for future graphene-based single-microwave photon detection.

  5. Meteorite heat capacities: Results to date

    Science.gov (United States)

    Consolmagno, G.; Macke, R.; Britt, D.

    2014-07-01

    Heat capacity is an essential thermal property for modeling asteroid internal metamorphism or differentiation, and dynamical effects like YORP or Yarkovsky perturbations. We have developed a rapid, inexpensive, and non-destructive method for measuring the heat capacity of meteorites at low temperature [1]. A sample is introduced into a dewar of liquid nitrogen and an electronic scale measures the amount of nitrogen boiled away as the sample is cooled from the room temperature to the liquid nitrogen temperature; given the heat of vaporization of liquid nitrogen, one can then calculate the heat lost from the sample during the cooling process. Note that heat capacity in this temperature range is a strong function of temperature, but this functional relation is essentially the same for all materials; the values we determine are equivalent to the heat capacity of the sample at 175 K. To correct for systematic errors, samples of laboratory-grade quartz are measured along with the meteorite samples. To date, more than 70 samples of more than 50 different meteorites have been measured in this way, including ordinary chondrites [1], irons [2], basaltic achondrites [3], and a limited number of carbonaceous chondrites [1]. In general, one can draw a number of important conclusions from these results. First, the heat capacity of a meteorite is a function of its mineral composition, independent of shock, metamorphism, or other physical state. Second, given this relation, heat capacity can be strongly altered by terrestrial weathering. Third, the measurement of heat capacity in small (less than 1 g) samples as done typically by commercial systems runs a serious risk of giving misleading results for samples that are heterogeneous on scales of tens of grams or more. Finally, we demonstrate that heat capacity is a useful tool for determining and classifying a sample, especially if used in conjunction with other intrinsic variables such as grain density and magnetic susceptibility

  6. Heat capacity of spinning plasma

    Science.gov (United States)

    Geyko, V. I.; Fisch, N. J.

    2017-10-01

    Equilibrium thermodynamics properties, such as heat capacity and adiabatic axial and radial compressibility of a rotating plasma column are studied. These properties depend on rotation speed, charge density, external magnetic field strength and electron-ion mass ratio. Plasma rotation serves as an additional energy storage, hence, yields to increased heat capacity. It also leads to charge separation that changes plasma density distribution due to electrostatic interaction and Lorentz force and therefore modifies thermodynamic properties. The obtained results can provide limits and optimal regimes for radial compression of z-pinch type structures and optimize energy deposition profile. This work was supported by NNSA DE-NA0001836 and DE-NA0002948 and by NSF Contract No. PHY-1506122.

  7. Gas Nonideality at One Atmosphere Revealed through Speed of Sound Measurements and Heat Capacity Determinations

    Science.gov (United States)

    Halpern, Arthur M.; Liu, Allen

    2008-01-01

    Using an easy-to-make cylindrical resonator, students can measure the speed of sound in a gas, u, with sufficiently high precision (by locating standing-wave Lissajous patterns on an oscilloscope) to observe real gas properties at one atmosphere and 300 K. For CO[subscript 2] and SF[subscript 6], u is found to be 268.83 and 135.25 m s[superscript…

  8. An adiabatic calorimeter for heat capacity measurements of polyurethane foam with blowing agent of HFC245fa in the temperature range 60-290K

    Energy Technology Data Exchange (ETDEWEB)

    Yang, C.G.; Xu, L.; Zhang, L.Q.; Chen, N. [Institute of Refrigeration and Cryogenics, Shanghai Jiao Tong University, Shanghai 200030 (China)

    2006-06-15

    In order to meet the urgent need of heat insulating materials used under low temperature in the area of aerospace, a new polyurethane (PU) foam with HFC245fa as blowing agent was developed. In this paper, the heat capacity in the temperature range of 60-290K of the new material was measured through an automated adiabatic calorimeter, which was composed of a heat insulation system, a power measuring system, a vacuum pumping system and a cooling system. The sample cell of the calorimeter was equipped with a miniature platinum thermometer surrounded by two adiabatic shields and housed in a high vacuum can. The temperature differences among the sample cell and the inner and outer adiabatic shields could be adjusted automatically to less than 0.05K, all which ensure there was no heat exchange between the sample and surroundings. Under these conditions, the mathematical formulation of the sample with the physical model was given. Through measuring the heat capacity of {alpha}-Al{sub 2}O{sub 3}, which is a standard reference material, a relatively high reliability with a deviation of +/-2.5% of this adiabatic calorimeter was shown compared with the standard data. The results indicate that the newly developed PU foam has a higher heat capacity compared with other heat insulating materials, and there is no obvious sign of any phase transition or thermal anomaly in the entire temperature range. That is to say, the material is thermodynamically stable when used in the low temperature range. (author)

  9. An adiabatic calorimeter for heat capacity measurements of polyurethane foam with blowing agent of HFC245fa in the temperature range 60-290 K

    Energy Technology Data Exchange (ETDEWEB)

    Yang, C.G. [Institute of Refrigeration and Cryogenics, Shanghai Jiao Tong University, Shanghai 200030 (China)]. E-mail: chunguang_yang@sjtu.edu.cn; Xu, L. [Institute of Refrigeration and Cryogenics, Shanghai Jiao Tong University, Shanghai 200030 (China); Zhang, L.Q. [Institute of Refrigeration and Cryogenics, Shanghai Jiao Tong University, Shanghai 200030 (China); Chen, N. [Institute of Refrigeration and Cryogenics, Shanghai Jiao Tong University, Shanghai 200030 (China)

    2006-06-15

    In order to meet the urgent need of heat insulating materials used under low temperature in the area of aerospace, a new PU foam with HFC245fa as blowing agent was developed. In this paper, the heat capacity in the temperature range of 60-290 K of the new material was measured through an automated adiabatic calorimeter, which was composed of a heat insulation system, a power measuring system, a vacuum pumping system and a cooling system. The sample cell of the calorimeter was equipped with a miniature platinum thermometer surrounded by two adiabatic shields and housed in a high vacuum can. The temperature differences among the sample cell and the inner and outer adiabatic shields could be adjusted automatically to less than 0.05 K, all which ensure there was no heat exchange between the sample and surroundings. Under these conditions, the mathematical formulation of the sample with the physical model was given. Through measuring the heat capacity of {alpha}-Al{sub 2}O{sub 3}, which is a standard reference material, a relatively high reliability with a deviation of {+-}2.5% of this adiabatic calorimeter was shown compared with the standard data. The results indicate that the newly developed PU foam has a higher heat capacity compared with other heat insulating materials, and there is no obvious sign of any phase transition or thermal anomaly in the entire temperature range. That is to say, the material is thermodynamically stable when used in the low temperature range.

  10. Thermodynamic properties in the normal and superconducting states of Na(x)CoO(2)*yH(2)O powder measured by heat capacity experiments

    OpenAIRE

    Lorenz, B.; Cmaidalka, J.; Meng, R. L.; Chu, C. W.

    2003-01-01

    The heat capacity of superconducting Na(x)CoO(2)*yH(2)O was measured and the data are discussed based on three different models: The thermodynamic Ginzburg-Landau model, the BCS theory, and a model including the effects of line nodes in the superconducting gap function. The electronic heat capacity is separated from the lattice contribution in a thermodynamically consistent way maintaining the entropy balance of superconducting and normal states at the critical temperature. It is shown that f...

  11. Heat capacity and sticking probability measurements of sup 4 He submonolayers adsorbed on evaporated Ag films: Bose statistics in two dimensions

    Energy Technology Data Exchange (ETDEWEB)

    Kenny, T.W.; Richards, P.L. (Department of Physics, University of California, Berkeley, Berkeley, CA (USA) Materials and Chemical Sciences Division, Lawrence Berkeley Laboratories, Berkeley, CA (USA))

    1990-05-14

    We have measured the heat capacity of submonolayers of {sup 4}He adsorbed on Ag films between 1.7 and 3.3 K. Good fits to the results are obtained with a model of a noninteracting two-dimensional Bose gas. The sticking probability for room-temperature {sup 4}He atoms on cold Ag has been measured as a function of substrate temperature and {sup 4}He coverage. The sticking probability is 4% at low coverage, and abruptly drops to 1% for coverages above 0.5 monolayer.

  12. An automated flow calorimeter for heat capacity and enthalpy measurements at elevated temperatures and pressures: Progress report for period March 1, 1988--February 29, 1989

    Energy Technology Data Exchange (ETDEWEB)

    Yesavage, V.F.

    1988-10-30

    The need for thermal property data at process conditions has been well documented in applications such as development of atmospherically inert refrigerants and design of petrochemical and synfuel plants. As such, the primary objective of this work is to construct an automated flow calorimeter to measure isobaric heat capacities and enthalpies of vaporization over the range 0--30MPa and 300--700K with an anticipated accuracy of 0.1%. The method of measurement is an adiabatic electrical power input technique with a unique calorimeter design utilizing a concentric coil/radiation shield structure which minimizes heat loss errors and simplifies the replacement of plugged components. Flow generation is accomplished with a precision Ruska pump eliminating the need for on-line flow rate measurement. In addition, the proposed instrument will be fully automated minimizing the need for highly skilled operators which had previously been a severe limitation with this type of instrument. Assembly of all hardware and implementation of the necessary software was completed within the past year. In addition, water was used as a heat capacity standard to evaluate overall system performance. Preliminary indications are that the apparatus is operating near expectations (+//minus/0.2%) although some additional hardware refinements may be necessary achieve the design goals of +//minus/0.1%. 15 refs., 4 figs., 1 tab.

  13. Heat Capacity Mapping Mission: 1978-1980

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — NASA's Heat Capacity Mapping Mission (HCMM) project collected Earth data in the visible and thermal bands between April 1978 and September 1980. This was an...

  14. The capacity credit of micro-combined heat and power

    Energy Technology Data Exchange (ETDEWEB)

    Hawkes, A.D. [Centre for Energy Policy and Technology, Imperial College London, Exhibition Road, London SW7 2AZ (United Kingdom); Leach, M.A. [Centre for Environmental Strategy, Faculty of Engineering, University of Surrey, Guildford GU2 7XH (United Kingdom)

    2008-04-15

    This article is concerned with development of a methodology to determine the capacity credit of micro-combined heat and power (micro-CHP), and application of the method for the UK. Capacity credit is an important parameter in electricity system planning because it measures the amount of conventional generation that would be displaced by an alternative technology. Firstly, a mathematical formulation is presented. Capacity credit is then calculated for three types of micro-CHP units - Stirling engine, internal combustion engine, and fuel cell systems - operating under various control strategies. It is found that low heat-to-power ratio fuel cell technologies achieve the highest capacity credit of approximately 85% for a 1.1 GW penetration when a heat-led control strategy is applied. Higher heat-to-power ratio Stirling engine technology achieves approximately 33% capacity credit for heat-led operation. Low heat-to-power ratio technologies achieve higher capacity credit because they are able to continue operating even when heat demand is relatively low. Capacity credit diminishes as penetration of the technology increases. Overall, the high capacity credit of micro-CHP contributes to the viewpoint that the technology can help meet a number of economic and environmental energy policy aims. (author)

  15. Alternating current calorimeter for specific heat capacity measurements at temperatures below 10 K and pressures up to 10 GPa

    Energy Technology Data Exchange (ETDEWEB)

    Umeo, Kazunori, E-mail: kumeo@sci.hiroshima-u.ac [Cryogenics and Instrumental Analysis Division, N-BARD, Hiroshima University, Kagamiyama 1-3-1, Higashi-Hiroshima 739-8526 (Japan)

    2016-06-15

    A developed alternating current calorimeter for measuring the absolute value of specific heat C of a very small sample under a pressure up to 10 GPa and low temperature below 10 K is described. A Bridgman anvil cell made of tungsten carbide with a top diameter of 3 mm is used. A hollow at the top prevents expansion of the sample space over the anvil top. Two chip resistors, which act as a thermometer and a heater, are mounted on the outer part of a copper–beryllium gasket with a frying pan-like shape. Thus, the thermometer is not pressurized. In order to isolate the gasket from the anvil thermally, diamond powder with a grain size of 0.25 μm is placed on the anvil top. Two jumps of C at the superconducting transitions of Pb (3.3 mg) and In (5.0 mg) are observed under various pressures up to 9 GPa, as clearly as those at the ambient pressure.

  16. Heat capacity of GdNi sub 5

    Energy Technology Data Exchange (ETDEWEB)

    Szewczyk, A. (Inst. of Physics, Polish Academy of Sciences, Warsaw (Poland)); Radwanski, R.J.; Franse, J.J.M.; Nakotte, H. (Natuurkundig Lab., Univ. van Amsterdam (Netherlands))

    1992-02-01

    The heat capacity of GdNi{sub 5} was measured from 1.3 to 48 K in a fixed magnetic field (up to 5 T). The electronic, phonon, and magnetic contributions were separated. Temperature dependences of magnetic specific heat and entropy were calculated in the molecular field approximation. They are in good agreement with the experimental results. (orig.).

  17. Residential Variable-Capacity Heat Pumps Sized to Heating Loads

    Energy Technology Data Exchange (ETDEWEB)

    Munk, Jeffrey D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Jackson, Roderick K. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Odukomaiya, Adewale [Georgia Inst. of Technology, Atlanta, GA (United States); Gehl, Anthony C. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2014-01-01

    Variable capacity heat pumps are an emerging technology offering significant energy savings potential and improved efficiency. With conventional single-speed systems, it is important to appropriately size heat pumps for the cooling load as over-sizing would result in cycling and insufficient latent capacity required for humidity control. These appropriately sized systems are often under-sized for the heating load and require inefficient supplemental electric resistance heat to meet the heating demand. Variable capacity heat pumps address these shortcomings by providing an opportunity to intentionally size systems for the dominant heating season load without adverse effects of cycling or insufficient dehumidification in the cooling season. This intentionally-sized system could result in significant energy savings in the heating season, as the need for inefficient supplemental electric resistance heat is drastically reduced. This is a continuation of a study evaluating the energy consumption of variable capacity heat pumps installed in two unoccupied research homes in Farragut, a suburb of Knoxville, Tennessee. In this particular study, space conditioning systems are intentionally sized for the heating season loads to provide an opportunity to understand and evaluate the impact this would have on electric resistance heat use and dehumidification. The results and conclusions drawn through this research are valid and specific for portions of the Southeastern and Midwestern United States falling in the mixed-humid climate zone. While other regions in the U.S. do not experience this type of climate, this work provides a basis for, and can help understand the implications of other climate zones on residential space conditioning energy consumption. The data presented here will provide a framework for fine tuning residential building EnergyPlus models that are being developed.

  18. Determination of the heat capacities of Lithium/BCX (bromide chloride in thionyl chloride) batteries

    Science.gov (United States)

    Kubow, Stephen A.; Takeuchi, Kenneth J.; Takeuchi, Esther S.

    1989-01-01

    Heat capacities of twelve different Lithium/BCX (BrCl in thionyl chloride) batteries in sizes AA, C, D, and DD were determined. Procedures and measurement results are reported. The procedure allowed simple, reproducible, and precise determinations of heat capacities of industrially important Lithium/BCX cells, without interfering with performance of the cells. Use of aluminum standards allowed the accuracy of the measurements to be maintained. The measured heat capacities were within 5 percent of calculated heat capacity values.

  19. Classical fluids of negative heat capacity

    Energy Technology Data Exchange (ETDEWEB)

    Landsberg, P.T. (Southampton Univ., (United Kingdom). Faculty of Mathematical Studies); Woodard, R.P. (Florida Univ., Gainesville, FL (United States). Dept. of Physics)

    1992-06-01

    It is shown that new parameters X can be defined such that the heat capacity C{sub X} {equivalent to} T({partial derivative}S/{partial derivative}T)X is negative, even when the canonical ensemble (i.e. at fixed T = ({partial derivative}U/{partial derivative}S) and Y {ne} X) is stable. As examples we treat black body radiation and general gas systems with nonsingular {kappa}{sub T}. For the case of a simple ideal gas we even exhibit an apparatus which enforces a constraint X(p,V) = const. that makes C{sub X} < 0. Since it is possible to invent constraints for which canonically stable systems have negative heat capacity we speculate that it may also be possible to infer the statistical mechanics of canonically unstable systems - for which even the traditional heat capacities are negative - by imposing constraints that stabilize the associated, inoncanonical ensembles.

  20. Classical fluids of negative heat capacity

    Energy Technology Data Exchange (ETDEWEB)

    Landsberg, P.T. [Southampton Univ., (United Kingdom). Faculty of Mathematical Studies; Woodard, R.P. [Florida Univ., Gainesville, FL (United States). Dept. of Physics

    1992-06-01

    It is shown that new parameters X can be defined such that the heat capacity C{sub X} {equivalent_to} T({partial_derivative}S/{partial_derivative}T)X is negative, even when the canonical ensemble (i.e. at fixed T = ({partial_derivative}U/{partial_derivative}S) and Y {ne} X) is stable. As examples we treat black body radiation and general gas systems with nonsingular {kappa}{sub T}. For the case of a simple ideal gas we even exhibit an apparatus which enforces a constraint X(p,V) = const. that makes C{sub X} < 0. Since it is possible to invent constraints for which canonically stable systems have negative heat capacity we speculate that it may also be possible to infer the statistical mechanics of canonically unstable systems - for which even the traditional heat capacities are negative - by imposing constraints that stabilize the associated, inoncanonical ensembles.

  1. An automated flow calorimeter for heat capacity and enthalpy measurements at elevated temperatures and pressures: Progress report, March 1, 1987-February 29, 1988

    Energy Technology Data Exchange (ETDEWEB)

    Yesavage, V.F.

    1987-10-01

    The need for thermal property data at process conditions in the design of petrochemical and synfuel plants has been well documented. As such, the primary objective of this work is to construct an automated flow calorimeter to measure isobaric heat capacities and enthalpies of vaporization over the range 0 to 30MPa and 300 to 700K with an anticipated accuracy of 0.1%. The method of measurement is by the traditional electrical power input technique with a unique calorimeter design utilizing a concentric coil/radiation shield structure which minimizes heat loss errors and simplifies the replacement of plugged components. Flow generation is accomplished with a precision Ruska pump eliminating the need for on-line flow rate measurement. In addition, the proposed instrument will be fully automated minimizing the need for highly skilled operators which had previously been a severe limitation with this type of instrument. Significant progress has been made on the project this last year with the completion of construction of all major system hardware components and the associated automation electronics. Initial tests of the equipment are encouraging and no significant delays are foreseen in the completion of the apparatus. During the next year the automation and data acquisition software will be written and the completed unit will be tested with water. 7 figs.

  2. Systematic Studies on Anharmonicity of Rattling Phonons in Type I Clathrates by Low Temperature Heat Capacity Measurements

    Science.gov (United States)

    Tanigaki, Katsumi; Wu, Jiazhen; Tanabe, Yoichi; Heguri, Satoshi; Shiimotani, Hidekazu; Tohoku University Collaboration

    2014-03-01

    Clathrates are featured by cage-like polyhedral hosts mainly composed of the IVth group elements of Si, Ge, or Sn and alkali metal or alkaline-earth metal elements can be accommodated inside as a guest atom. One of the most intriguing issues in clathrates is their outstanding high thermoelectric performances thanks to the low thermal conductivity. Being irrespective of good electric conductivity σ, the guest atom motions provide a low-energy lying less-dispersive phonons and can greatly suppress thermal conductivity κ. This makes clathrates close to the concept of ``phonon glass electron crystal: PGEC'' and useful in thermoelectric materials from the viewpoint of the figure of merit. In the present study, we show that the local phonon anharmonicity indicated by the tunneling-term of the endohedral atoms (αT) and the itinerant-electron term (γeT), both of which show T-linear dependences in specific heat Cp, can successfully be separated by employing single crystals with various carrier concentrations in a wide range of temperture experimennts. The factors affecting on the phonon anharmonicity as well as the strength of electron-phonon interactions will be discussed based on our recent experiments. The research was financially supported by Ministry of Education, Science, Sports and Culture, Grant in Aid for Science, and Technology of Japan.

  3. Negative heat capacities in central Xe+Sn reactions

    Energy Technology Data Exchange (ETDEWEB)

    Le Neindre, N.; Bougault, R.; Gulminelli, F. [Laboratoire de Physique Corpusculaire, IN2P3-CNRS, ISMRA et Universite, 14 - Caen (France)] [and others

    2000-02-01

    In this study the fluctuation method is applied to the 32-50 A.MeV Xe + Sn central collisions detected with the INDRA multidetector. This method based on kinetic energy fluctuations allows the authors to provide information on the liquid gas phase transition in nuclear multifragmentation. In the case of Xe + Sn central reactions a divergence in the total heat capacity is observed. This divergence corresponds to large fluctuations on the detected fragment partitions. A negative heat capacity branch is measured and so tends to confirm the observation of a first order phase transition in heavy-ion collisions. (A.C.)

  4. Heat capacity measurement and EXAFS study of (U{sub 0.85}Mg{sub 0.15})O{sub 2{minus}x} for x = 0 and 0.1

    Energy Technology Data Exchange (ETDEWEB)

    Atita, Y; Matsui, T. [Nagoya Univ. (Japan); Ohno, H. [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Office of Synchrotron Radiation Facility Project; Kobayashi, K. [National Lab. for High Energy Physics, Tsukuba, Ibaraki (Japan). Photon Factory

    1997-03-01

    Heat capacities and electrical conductivities of (U{sub 0.85}Mg{sub 0.15})O{sub 2{minus}x} (x = 0 and 0.1) were measured simultaneously by means of a direct heating pulse calorimeter (DHPC) in the temperature range from 300 to 1500 K. Anomalous increases in the heat capacity curves of (U{sub 0.85}Mg{sub 0.15})O{sub 2{minus}x} (x = 0 and 0.1) were observed above about 800 and 1150 K, respectively. The values for the enthalpy of oxygen Frenkel defect formation were calculated from the excess heat capacity and were found to be similar to those for UO{sub 2} doped with rare earth elements. On the other hand, no anomaly was seen in the electrical conductivity curve around the onset temperature of the anomalous increase in the heat capacity. It was, therefore, concluded that the excess heat capacity originates from the predominant contribution of the formation of Frenkel pair-like defects of oxygen. An extended X-ray absorption fine structure (EXAFS) experiment shows a different environment of oxygen around uranium and magnesium, and this should be a cause of the onset temperature difference.

  5. Heat Capacity and Thermal Conductance Measurements of a Superconducting-Normal Mixed State by Detection of Single 3 eV Photons in a Magnetic Penetration Thermometer

    Science.gov (United States)

    Stevenson, T. R.; Balvin, M. A.; Bandler, S. R.; Denis, K. L.; Lee, S.-J.; Nagler, P. C.; Smith, S. J.

    2015-01-01

    We report on measurements of the detected signal pulses in a molybdenum-gold Magnetic Penetration Thermometer (MPT) in response to absorption of one or more 3 eV photons. We designed and used this MPT sensor for x-ray microcalorimetry. In this device, the diamagnetic response of a superconducting MoAu bilayer is used to sense temperature changes in response to absorbed photons, and responsivity is enhanced by a Meissner transition in which the magnetic flux penetrating the sensor changes rapidly to minimize free energy in a mixed superconducting normal state. We have previously reported on use of our MPT to study a thermal phonon energy loss to the substrate when absorbing x-rays. We now describe results of extracting heat capacity C and thermal conductance G values from pulse height and decay time of MPT pulses generated by 3 eV photons. The variation in C and G at temperatures near the Meissner transition temperature (set by an internal magnetic bias field) allow us to probe the behavior in superconducting normal mixed state of the condensation energy and the electron cooling power resulting from quasi-particle recombination and phonon emission. The information gained on electron cooling power is also relevant to the operation of other superconducting detectors, such as Microwave Kinetic Inductance Detectors.

  6. The influence of working memory capacity on experimental heat pain.

    Science.gov (United States)

    Nakae, Aya; Endo, Kaori; Adachi, Tomonori; Ikeda, Takashi; Hagihira, Satoshi; Mashimo, Takashi; Osaka, Mariko

    2013-10-01

    Pain processing and attention have a bidirectional interaction that depends upon one's relative ability to use limited-capacity resources. However, correlations between the size of limited-capacity resources and pain have not been evaluated. Working memory capacity, which is a cognitive resource, can be measured using the reading span task (RST). In this study, we hypothesized that an individual's potential working memory capacity and subjective pain intensity are related. To test this hypothesis, we evaluated 31 healthy participants' potential working memory capacity using the RST, and then applied continuous experimental heat stimulation using the listening span test (LST), which is a modified version of the RST. Subjective pain intensities were significantly lower during the challenging parts of the RST. The pain intensity under conditions where memorizing tasks were performed was compared with that under the control condition, and it showed a correlation with potential working memory capacity. These results indicate that working memory capacity reflects the ability to process information, including precise evaluations of changes in pain perception. In this work, we present data suggesting that changes in subjective pain intensity are related, depending upon individual potential working memory capacities. Individual working memory capacity may be a phenotype that reflects sensitivity to changes in pain perception. Copyright © 2013 American Pain Society. Published by Elsevier Inc. All rights reserved.

  7. High-Capacity Heat-Pipe Evaporator

    Science.gov (United States)

    Oren, J. A.; Duschatko, R. J.; Voss, F. E.; Sauer, L. W.

    1989-01-01

    Heat pipe with cylindrical heat-input surface has higher contact thermal conductance than one with usual flat surface. Cylindrical heat absorber promotes nearly uniform flow of heat into pipe at all places around periphery of pipe, helps eliminate hotspots on heat source. Lugs in aluminum pipe carry heat from outer surface to liquid oozing from capillaries of wick. Liquid absorbs heat, evaporates, and passes out of evaporator through interlug passages.

  8. Low temperature heat capacity of lutetium and lutetium hydrogen alloys

    Energy Technology Data Exchange (ETDEWEB)

    Thome, David Keith [Iowa State Univ., Ames, IA (United States)

    1977-10-01

    The heat capacity of high purity electrotransport refined lutetium was measured between 1 and 20°K. Results for thetaD were in excellent agreement with theta values determined from elastic constant measurements. The heat capacity of a series of lutetium-hydrogen solid solution alloys was determined and results showed an increase in γ to about 11.3 mJ/g-atom-K2 for hydrogen content increasing from zero to about one atomic percent. Above one percent hydrogen γ decreased with increasing hydrogen contents. The C/T data showed an increase with temperature decreasing below about 2.5°K for samples with 0.1 to 1.5 atomic percent hydrogen. This accounts for a large amount of scatter in thetaD versus hydrogen content in this range. The heat capacity of a bulk sample of lutetium dihydride was measured between 1 and 20°K and showed a large increase in thetaD and a large decrease in ..gamma.. compared to pure lutetium.

  9. Evaluation of Heat Capacity and Resistance to Cyclic Oxidation of Nickel Superalloys

    Directory of Open Access Journals (Sweden)

    Przeliorz R.

    2014-08-01

    Full Text Available Paper presents the results of evaluation of heat resistance and specific heat capacity of MAR-M-200, MAR-M-247 and Rene 80 nickel superalloys. Heat resistance was evaluated using cyclic method. Every cycle included heating in 1100°C for 23 hours and cooling for 1 hour in air. Microstructure of the scale was observed using electron microscope. Specific heat capacity was measured using DSC calorimeter. It was found that under conditions of cyclically changing temperature alloy MAR-M-247 exhibits highest heat resistance. Formed oxide scale is heterophasic mixture of alloying elements, under which an internal oxidation zone was present. MAR-M-200 alloy has higher specific heat capacity compared to MAR-M-247. For tested alloys in the temperature range from 550°C to 800°C precipitation processes (γ′, γ″ are probably occurring, resulting in a sudden increase in the observed heat capacity.

  10. Reassembling and testing of a high-precision heat capacity drop calorimeter. Heat capacity of some polyphenyls at T = 298.15 K

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Luis M.N.B.F., E-mail: lbsantos@fc.up.pt [Centro de Investigacao em Quimica, Departamento de Quimica e Bioquimica, Faculdade de Ciencias, Universidade do Porto, Rua do Campo Alegre, 687, 4169-007 Porto (Portugal); Rocha, Marisa A.A.; Rodrigues, Ana S.M.C. [Centro de Investigacao em Quimica, Departamento de Quimica e Bioquimica, Faculdade de Ciencias, Universidade do Porto, Rua do Campo Alegre, 687, 4169-007 Porto (Portugal); Stejfa, Vojtech; Fulem, Michal [Department of Physical Chemistry, Institute of Chemical Technology, Technicka 5, CZ-166 28 Prague 6 (Czech Republic); Bastos, Margarida [Centro de Investigacao em Quimica, Departamento de Quimica e Bioquimica, Faculdade de Ciencias, Universidade do Porto, Rua do Campo Alegre, 687, 4169-007 Porto (Portugal)

    2011-12-15

    Graphical abstract: Highlights: > We present the reassembling, improvement and testing of a high-precision C{sub p} drop calorimeter. > The apparatus was tested, using benzoic acid and hexafluorobenzene. > The high sensitivity of the apparatus is comparable to the one obtained in adiabatic calorimetry. > Heat capacities at T = 298.15 K of some polyphenyls were measured. > Subtle heat capacity differences among position isomers (ortho, meta, para) were detected. - Abstract: The description of the reassembling and testing of a twin heat conduction, high-precision, drop microcalorimeter for the measurement of heat capacities of small samples are presented. The apparatus, originally developed and used at the Thermochemistry Laboratory, Lund, Sweden, has now been reassembled and modernized, with changes being made as regarding temperature sensors, electronics and data acquisition system. The apparatus was thereafter thoroughly tested, using benzoic acid and hexafluorobenzene as test substances. The accuracy of the C{sub p,m}{sup 0} (298.15 K) data obtained with this apparatus is comparable to that achieved by high-precision adiabatic calorimetry. Here we also present the results of heat capacity measurements on of some polyphenyls (1,2,3-triphenylbenzene, 1,3,5-triphenylbenzene, p-terphenyl, m-terphenyl, o-terphenyl, p-quaterphenyl) at T = 298.15 K, measured with the renewed high precision heat capacity drop calorimeter system. The high resolution and accuracy of the obtained heat capacity data enabled differentiation among the ortho-, meta-, and para-phenyl isomers.

  11. Electron heat capacity and lattice properties of Americium

    Science.gov (United States)

    Povzner, A. A.; Filanovich, A. N.; Os'kina, V. A.; Volkov, A. G.

    2013-12-01

    The temperature dependence of the electron heat capacity of americium is calculated using the concepts on the electronic structure and magnetic properties of this element. The Debye temperature, the thermal expansion coefficient, and the bulk modulus of americium are determined on the basis of the results of calculations and experimental data on heat capacity.

  12. A New Method for the Determination of the Specific Heat Capacity Using Laser-Flash Calorimetry Down to 77K

    Science.gov (United States)

    Göbel, A.; Hemberger, F.; Vidi, S.; Ebert, H.-P.

    2013-05-01

    A new method for evaluation of the specific heat capacity in the temperature regime between 77K and 330K using laser-flash calorimetry is presented. Usually, laser-flash calorimetry is accomplished by performing an additional laser-flash measurement on a reference specimen with a known specific heat capacity and by comparing the maximum rear-side temperatures rises. In this study, the calibration is achieved by comparison of the rear-side temperature rise to specific-heat-capacity data determined by other methods in an adjacent temperature regime. Subsequently, the thus yielded proportional factor is used for the evaluation of the specific heat capacity from laser-flash measurements at temperatures where no specific-heat-capacity data are available. The reliability of this method is shown by performing measurements on a material with known specific heat capacity, aluminum oxide. Furthermore, the specific heat capacity and thermal conductivity of borosilicate crown glass (BK7) was determined experimentally.

  13. Measuring of heat transfer coefficient

    DEFF Research Database (Denmark)

    Henningsen, Poul; Lindegren, Maria

    Subtask 3.4 Measuring of heat transfer coefficient Subtask 3.4.1 Design and setting up of tests to measure heat transfer coefficient Objective: Complementary testing methods together with the relevant experimental equipment are to be designed by the two partners involved in order to measure...... the heat transfer coefficient for a wide range of interface conditions in hot and warm forging processes. Subtask 3.4.2 Measurement of heat transfer coefficient The objective of subtask 3.4.2 is to determine heat transfer values for different interface conditions reflecting those typically operating in hot...

  14. Saturated-liquid heat capacity calculation of alkanes

    Directory of Open Access Journals (Sweden)

    JOVAN D. JOVANOVIC

    2005-12-01

    Full Text Available An empirical model for the calculation of the heat capacity of alkanes is recommended. This model was tested and compared to known models (Luria–Benson and Rizicka–Domalski using 68 sets with 1155 literature experimental heat capacity data of 39 alkanes. The obtained results indicate that the newmodel is slightly better tha the existing models, especially near the critical point.

  15. Prediction of nanofluids properties: the density and the heat capacity

    Science.gov (United States)

    Zhelezny, V. P.; Motovoy, I. V.; Ustyuzhanin, E. E.

    2017-11-01

    The results given in this report show that the additives of Al2O3 nanoparticles lead to increase the density and decrease the heat capacity of isopropanol. Based on the experimental data the excess molar volume and the excess molar heat capacity were calculated. The report suggests new method for predicting the molar volume and molar heat capacity of nanofluids. It is established that the values of the excess thermodynamic functions are determined by the properties and the volume of the structurally oriented layers of the base fluid molecules near the surface of nanoparticles. The heat capacity of the structurally oriented layers of the base fluid is less than the heat capacity of the base fluid for given parameters due to the greater regulation of its structure. It is shown that information on the geometric dimensions of the structured layers of the base fluid near nanoparticles can be obtained from data on the nanofluids density and at ambient temperature – by the dynamic light scattering method. For calculations of the nanofluids heat capacity over a wide range of temperatures a new correlation based on the extended scaling is proposed.

  16. Separation of Power and Capacity In latent Heat Energy Storage

    OpenAIRE

    Pointner, H.; Steinmann, W.D.; van Eck, M.; Bachelier, C.

    2015-01-01

    The state-of-the-art latent heat energy storage system is equipped with aluminum fins at the heat exchanger pipes in order to compensate the low thermal conductivity of the phase change material (PCM). The necessary amount of fins is directly coupled to the capacity of the storage system, what makes larger systems expensive. The PCMflux concept is developed in order to realize both a controllable and a possibly more cost effectivelatent heat storage system. These aims are addressed by separat...

  17. Can Science and Technology Capacity be Measured?

    CERN Document Server

    Wagner, Caroline S; Dutta, Arindum

    2015-01-01

    The ability of a nation to participate in the global knowledge economy depends to some extent on its capacities in science and technology. In an effort to assess the capacity of different countries in science and technology, this article updates a classification scheme developed by RAND to measure science and technology capacity for 150 countries of the world.

  18. Effect of Inhomogeneous Heat Flow on the Enhancement of Heat Capacity in Helium-II by Counterflow near Tλ

    Science.gov (United States)

    Boyd, S. T. P.; Chatto, A. R.; Lee, R. A. M.; Duncan, R. V.; Goodstein, D. L.

    2006-09-01

    In 2000 Harter et al. reported the first measurements of the enhancement of the heat capacity ΔCQ≡C(Q)-C(Q=0) of helium-II transporting a heat flux density Q near Tλ. Surprisingly, their measured ΔCQ was ˜7-12 times larger than predicted, depending on which theory was assumed. In this report we present a candidate explanation for this discrepancy: unintended heat flux inhomogeneity. Because C(Q) should diverge at a critical heat flux density Qc, homogeneous heat flow is required for an accurate measurement. We present results from numerical analysis of the heat flow in the Harter et al. cell indicating that substantial inhomogeneity occurred. We determine the effect of the inhomogeneity on ΔCQ and find rough agreement with the observed disparity between prediction and measurement.

  19. Measuring melting capacity with calorimetry

    OpenAIRE

    Betten, Linda

    2014-01-01

    Road salting is an important aspect of winter maintenance. There has been an increase in the usage of salt in later years to keep the road safe and accessible. It is a desire to reduce the amount of salt due to environmental aspects. To achieve better practices for winter maintenance it is necessary to obtain more knowledge about the different properties of salt. The motivation for this thesis is to develop a better method for determining the melting capacity for salt, which is an important p...

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

    DEFF Research Database (Denmark)

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

    2016-01-01

    In this study, a typical office room with a radiant heating system and a mechanical ventilation system was selected as the research subject. Indoor temperature formulas for calculating the room heat loss (including transmission heat loss and ventilation heat loss) and heating capacity of the hybrid...... for calculating ventilation heat loss and heating capacity of radiant heating systems combined with mechanical ventilation systems. (C) 2015 Elsevier B.V. All rights reserved....... change rates on the indoor temperatures were performed using the proposed model. When heated surface temperatures and air change rates were from 21.0 to 29.0 degrees C and from 0.5 to 4.0 h-1, the indoor temperatures for calculating the transmission heat loss and ventilation heat loss were between 20...

  1. Reductions in labour capacity from heat stress under climate warming

    Science.gov (United States)

    Dunne, John P.; Stouffer, Ronald J.; John, Jasmin G.

    2013-06-01

    A fundamental aspect of greenhouse-gas-induced warming is a global-scale increase in absolute humidity. Under continued warming, this response has been shown to pose increasingly severe limitations on human activity in tropical and mid-latitudes during peak months of heat stress. One heat-stress metric with broad occupational health applications is wet-bulb globe temperature. We combine wet-bulb globe temperatures from global climate historical reanalysis and Earth System Model (ESM2M) projections with industrial and military guidelines for an acclimated individual's occupational capacity to safely perform sustained labour under environmental heat stress (labour capacity)--here defined as a global population-weighted metric temporally fixed at the 2010 distribution. We estimate that environmental heat stress has reduced labour capacity to 90% in peak months over the past few decades. ESM2M projects labour capacity reduction to 80% in peak months by 2050. Under the highest scenario considered (Representative Concentration Pathway 8.5), ESM2M projects labour capacity reduction to less than 40% by 2200 in peak months, with most tropical and mid-latitudes experiencing extreme climatological heat stress. Uncertainties and caveats associated with these projections include climate sensitivity, climate warming patterns, CO2 emissions, future population distributions, and technological and societal change.

  2. Ambient heat capacities and entropies of ionic solids: a unique view using the Debye equation.

    Science.gov (United States)

    Glasser, Leslie

    2013-06-03

    Entropies of solids are obtained experimentally as integrals of measured heat capacities over the temperature range from zero to ambient. Correspondingly, the Debye phonon distribution equation for solids provides a theoretical connection between these two chemical thermodynamic measures. We examine how the widely applicable Debye equation illuminates the relation between the corresponding experimental measures using more than 250 ionic solids. Estimation of heat capacities for simple ionic solids by the Dulong-Petit heat capacity limit, by the Neumann-Kopp elemental sum, and by the ion sum method is examined in relation to the Debye equation. We note that, and explain why, the ambient temperature heat capacities and entropies of ionic solids are found to be approximately equal, and how deviations from equality may be related to the Debye temperature, ΘD, which characterizes the Debye equation. It is also demonstrated that Debye temperatures may be readily estimated from the experimental ratio of ambient heat capacity to entropy, C(p)/S(p), rather than requiring resort to elaborate theoretical or experimental procedures for their determination. Correspondingly, ambient mineral entropies and heat capacities are linearly correlated and may thus be readily estimated from one another.

  3. Maximum Power Point Characteristics of Generalized Heat Engines with Finite Time and Finite Heat Capacities

    Directory of Open Access Journals (Sweden)

    Abhishek Khanna

    2012-01-01

    Full Text Available We revisit the problem of optimal power extraction in four-step cycles (two adiabatic and two heat-transfer branches when the finite-rate heat transfer obeys a linear law and the heat reservoirs have finite heat capacities. The heat-transfer branch follows a polytropic process in which the heat capacity of the working fluid stays constant. For the case of ideal gas as working fluid and a given switching time, it is shown that maximum work is obtained at Curzon-Ahlborn efficiency. Our expressions clearly show the dependence on the relative magnitudes of heat capacities of the fluid and the reservoirs. Many previous formulae, including infinite reservoirs, infinite-time cycles, and Carnot-like and non-Carnot-like cycles, are recovered as special cases of our model.

  4. Development of a high capacity variable conductance heat pipe.

    Science.gov (United States)

    Kosson, R.; Hembach, R.; Edelstein, F.; Loose, J.

    1973-01-01

    The high-capacity, pressure-primed, tunnel-artery wick concept was used in a gas-controlled variable conductance heat pipe. A variety of techniques were employed to control the size of gas/vapor bubbles trapped within the artery. Successful operation was attained with a nominal 6-foot long, 1-inch diameter cold reservoir VCHP using ammonia working fluid and nitrogen control gas. The pipe contained a heat exchanger to subcool the liquid in the artery. Maximum transport capacity with a 46-inch effective length was 1200 watts level (more than 50,000 watt-inches) and 800 watts at 0.5-inch adverse tilt.

  5. On the Einstein-Stern model of rotational heat capacities

    DEFF Research Database (Denmark)

    Dahl, Jens Peder

    1998-01-01

    The Einstein-Stern model for the rotational contribution to the heat capacity of a diatomic gas has recently been resuscitated. In this communication, we show that the apparent success of the model is illusory, because it is based on what has turned out to be an unfortunate comparison with experi......The Einstein-Stern model for the rotational contribution to the heat capacity of a diatomic gas has recently been resuscitated. In this communication, we show that the apparent success of the model is illusory, because it is based on what has turned out to be an unfortunate comparison...

  6. Hybrid heat capacity-moving slab solid-state laser

    Science.gov (United States)

    Stappaerts, Eddy A.

    2005-03-01

    Laser material is pumped and its stored energy is extracted in a heat capacity laser mode at a high duty factor. When the laser material reaches a maximum temperature, it is removed from the lasing region and a subsequent volume of laser material is positioned into the lasing region to repeat the lasing process. The heated laser material is cooled passively or actively outside the lasing region.

  7. Thermodynamic properties of zeolites: low-temperature heat capacities and thermodynamic functions for phillipsite and clinoptilolite. Estimates of the thermochemical properties of zeolitic water at low temperature.

    Science.gov (United States)

    Hemingway, B.S.; Robie, R.A.

    1984-01-01

    Measured heat capacities between 15 and 305 K and calculated heat capacities, entropies, enthalpy functions and Gibbs energy functions are reported and analysed for phillipsite and clinoptilolite. - J.A.Z.

  8. Heat capacity changes in carbohydrates and protein-carbohydrate complexes.

    Science.gov (United States)

    Chavelas, Eneas A; García-Hernández, Enrique

    2009-05-13

    Carbohydrates are crucial for living cells, playing myriads of functional roles that range from being structural or energy-storage devices to molecular labels that, through non-covalent interaction with proteins, impart exquisite selectivity in processes such as molecular trafficking and cellular recognition. The molecular bases that govern the recognition between carbohydrates and proteins have not been fully understood yet. In the present study, we have obtained a surface-area-based model for the formation heat capacity of protein-carbohydrate complexes, which includes separate terms for the contributions of the two molecular types. The carbohydrate model, which was calibrated using carbohydrate dissolution data, indicates that the heat capacity contribution of a given group surface depends on its position in the saccharide molecule, a picture that is consistent with previous experimental and theoretical studies showing that the high abundance of hydroxy groups in carbohydrates yields particular solvation properties. This model was used to estimate the carbohydrate's contribution in the formation of a protein-carbohydrate complex, which in turn was used to obtain the heat capacity change associated with the protein's binding site. The model is able to account for protein-carbohydrate complexes that cannot be explained using a previous model that only considered the overall contribution of polar and apolar groups, while allowing a more detailed dissection of the elementary contributions that give rise to the formation heat capacity effects of these adducts.

  9. Space qualification of high capacity grooved heat pipes

    Energy Technology Data Exchange (ETDEWEB)

    Dubois, M.; Mullender, B.; Druart, J. [SABCA, Societe Anomyme Belgel de Construction Aeronautique (Belgium); Supper, W.; Beddows, A. [ESTEC-The (Netherlands)

    1996-12-31

    Based on the thermal requirements of the future telecommunication satellites, the development of a High Capacity Grooved Heat Pipe (HPG), was contracted by ESA to SABCA leading to an aluminium extruded heat pipe (outer diameter of 25 mm) based on a multi re-entrant grooves design. After an intensive acceptance test campaign whose results showed a good confidence in the design and the fulfillment of the required specifications of heat transport and on tilt capability (experimental maximum heat transport capability of 1500 Watt metres for a vapour temperature of 20 deg C), similar heat pipes have been developed with various outer diameters (11 mm, 15 mm and 20 mm) and with various shapes (circular outer shapes, integrated saddles). Several of these heat pipes were tested during two parabolic flight campaigns, by varying the heat loads during the micro-gravity periods. This HGP heat pipe family is now being submitted to a space qualification program according to ESA standards (ESA PSS-49), both in straight and bent configuration. Within this qualification, the heat pipes are submitted to an extended test campaign including environmental (random/sinus vibration, constant acceleration) and thermal tests (thermal performance, thermal cycle, thermal soak, ageing). (authors) 9 refs.

  10. Measuring effective capacity in an emergency department.

    Science.gov (United States)

    Lantz, Björn; Rosén, Peter

    2016-01-01

    The purpose of this paper is to show how elements from queueing theory can be used to obtain objective measures of effective capacity in the triage function at Skaraborg Hospital in Sweden without direct observation of the function itself. Approximately 30,000 patients arrived to the emergency department at Skaraborg Hospital in Sweden during 2011. The exact time of arrival and the exact time of triage were recorded for each patient on an individual level. Basic queueing theory uses arrival rates and system capacity measures to derive average queueing times. The authors use the theoretical relation between these three measures to derive system capacity measures based on observed arrival rates and observed average queueing times. The effective capacity in the triage process is not a linear function of the number of nurses. However, the management of capacity seems well adapted to the actual demand, even though service levels vary substantially during the day and night. This paper uses elements from queueing theory in an innovative way to measure the effective capacity of a service process without direct observation, thereby also avoiding the potential risk of the Hawthorne effect.

  11. Latent heat sink in soil heat flux measurements

    Science.gov (United States)

    The surface energy balance includes a term for soil heat flux. Soil heat flux is difficult to measure because it includes conduction and convection heat transfer processes. Accurate representation of soil heat flux is an important consideration in many modeling and measurement applications. Yet, the...

  12. Heat Capacity, Crystallization, and Nucleation in Poly(vinyl alcohol) Thin Films

    Science.gov (United States)

    Thomas, David; Wurm, Andreas; Zhuravlev, Evgeny; Schick, Christoph; Cebe, Peggy

    Polyvinyl alcohol (PVA) is hydrophilic, biodegradable, semi-crystalline polymer with a wide array of applications ranging from textiles and packaging to medicine. Despite possessing favorable properties, PVA thermally degrades at temperatures just in excess of 200 °C which occurs slightly below the observed peak endothermic melting peak at 203 °C. Utilizing fast scanning calorimetry it is possible to minimize sample degradation allowing measurements of the liquid phase heat capacity as well as study nucleation and crystallization from the amorphous melt state. Samples cut from parent films 2-3 μm thick were placed on UFSC1 sensors and brought between -80 and 270 °C at rates of 2000 °C/s under a nitrogen atmosphere. After five complete cycles samples did not show any signs of degradation. By fitting the symmetry corrected glassy phase heat capacity with literature values for the specific heat capacity from the ATHAS databank sample masses were determined to vary between 15-50 ng. Homogeneous nucleation was observed for all samples cooled from the melt with peak temperature 123 °C. Fitting linear heat capacity baselines in the melt and glassy states it was possible to obtain an experimental measurement of the heat capacity increment 44.5 J/mol K at the glass transition 85 °C. NSF DMR-1206010.

  13. Excess enthalpy, density, and heat capacity for binary systems of alkylimidazolium-based ionic liquids + water

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Miaja, Gonzalo; Troncoso, Jacobo [Departamento de Fisica Aplicada, Universidad de Vigo, Facultad de Ciencias, Campus As Lagoas, 32004 Ourense (Spain); Romani, Luis [Departamento de Fisica Aplicada, Universidad de Vigo, Facultad de Ciencias, Campus As Lagoas, 32004 Ourense (Spain)], E-mail: romani@uvigo.es

    2009-02-15

    Experimental measurements of excess molar enthalpy, density, and isobaric molar heat capacity are presented for a set of binary systems ionic liquid + water as a function of temperature at atmospheric pressure. The studied ionic liquids are 1-butyl-3-methylpyridinium tetrafluoroborate, 1-ethyl-3-methylimidazolium ethylsulfate, 1-butyl-3-methylimidazolium methylsulfate, 1-butyl-3-methylimidazolium trifluoromethanesulfonate, and 1-ethyl-3-methylimidazolium trifluoromethanesulfonate. Excess molar enthalpy was measured at 303.15 K whereas density and heat capacity were determined within the temperature range (293.15 to 318.15) K. From experimental data, excess molar volume and excess molar isobaric heat capacity were calculated. The analysis of the excess properties reveals important differences between the studied ionic liquids which can be ascribed to their capability to form hydrogen bonds with water molecules.

  14. Investigation of high capacity heat energy storage for building applications

    OpenAIRE

    Ding, Yate

    2014-01-01

    The problems of excessive consumption of fossil resources, oil shortages and greenhouse gas emissions are becoming increasingly severe. Research and development work on new methods of thermal energy storage are imminently required. To effectively store seasonal renewable energy, a novel high capacity heat storage system has been designed and evaluated/validated through laboratory experiments and numerical simulations in this research. The system is driven by direct flow evacuated tube solar c...

  15. Heat capacities and thermal diffusivities of n-alkane acid ethyl esters—biodiesel fuel components

    Science.gov (United States)

    Bogatishcheva, N. S.; Faizullin, M. Z.; Nikitin, E. D.

    2017-09-01

    The heat capacities and thermal diffusivities of ethyl esters of liquid n-alkane acids C n H2 n-1O2C2H5 with the number of carbon atoms in the parent acid n = 10, 11, 12, 14, and 16 are measured. The heat capacities are measured using a DSC 204 F1 Phoenix heat flux differential scanning calorimeter (Netzsch, Germany) in the temperature range of 305-375 K. Thermal diffusivities are measured by means of laser flash method on an LFA-457 instrument (Netzsch, Germany) at temperatures of 305-400 K. An equation is derived for the dependence of the molar heat capacities of the investigated esters on temperature. It is shown that the dependence of molar heat capacity C p,m (298.15 K) on n ( n = 1-6) is close to linear. The dependence of thermal diffusivity on temperature in the investigated temperature range is described by a first-degree polynomial, but thermal diffusivity a (298.15 K) as a function of n has a minimum at n = 5.

  16. High capacity demonstration of honeycomb panel heat pipes

    Science.gov (United States)

    Tanzer, H. J.

    1989-01-01

    The feasibility of performance enhancing the sandwich panel heat pipe was investigated for moderate temperature range heat rejection radiators on future-high-power spacecraft. The hardware development program consisted of performance prediction modeling, fabrication, ground test, and data correlation. Using available sandwich panel materials, a series of subscale test panels were augumented with high-capacity sideflow and temperature control variable conductance features, and test evaluated for correlation with performance prediction codes. Using the correlated prediction model, a 50-kW full size radiator was defined using methanol working fluid and closely spaced sideflows. A new concept called the hybrid radiator individually optimizes heat pipe components. A 2.44-m long hybrid test vehicle demonstrated proof-of-principle performance.

  17. High-temperature heat capacity of CdO-V2O5 oxides

    Science.gov (United States)

    Denisova, L. T.; Chumilina, L. G.; Belousova, N. V.; Denisov, V. M.; Galiakhmetova, N. A.

    2017-12-01

    Vanadates Cd2V2O7 and CdV2O6 have been prepared from CdO i V2O5 by three-phase synthesis with subsequent burning at 823-1073 K and 823-853 K, respectively. The molar heat capacity of these oxide compounds has been measured by differential scanning calorimetry. The enthalpy change, the entropy change, and the reduced Gibbs energy are calculated using the experimental dependences C p = f( T). It is shown that there is a correlation between the specific heat capacity and the composition of CdO-V2O5 oxide system.

  18. Measuring Innovative Capacities of the Georgia Regions

    Directory of Open Access Journals (Sweden)

    Joseph Gogodze

    2013-10-01

    Full Text Available European Union (EU experience reveal that the composite indicators are probably the most useful instruments for measuring the innovative capacities at the regional (sub-national level. However, some gap exists in the current literature with respect to the elaboration of composite indicators for regional innovation systems (RISs of developing countries. This article introduces the composite indicators GRIS and GCLS for measuring the regional innovative capacities (for GNUTS1 and GNUTS2 territorial classification levels, respectively. Georgia is a useful case-subject because its smallscale developing economy presents special challenges for elaborating the composite indicators for RISs. This article also includes a brief analysis using these composite indicators and indicates the significant heterogeneity among the innovative capacities of the Georgian regions.

  19. THE HEAT CAPACITY OF FLUORINATED PROPANE AND BUTANE DERIVATIVES BY DIFFERENTIAL SCANNING CALORIMETRY

    Science.gov (United States)

    The paper gives results of the measurement (to 3% accuracy) of the constant-pressure liquid-phase heat capacities of 21 hydrogen-containing fluorinated propane and butane derivatives and one fluorinated ether (CF3OCF2H) with boiling points ranging from -34.6 to 76.7 C, using diff...

  20. Liquid heat capacity of the solvent system (piperazine + 2-amino-2-methyl-l-propanol + water)

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Y.-R. [R and D Center for Membrane Technology and Department of Chemical Engineering, Chung Yuan Christian University, Chung Li 32023, Taiwan (China); Caparanga, Alvin R.; Soriano, Allan N. [R and D Center for Membrane Technology and Department of Chemical Engineering, Chung Yuan Christian University, Chung Li 32023, Taiwan (China); School of Chemical Engineering and Chemistry, Mapua Institute of Technology, Intramuros, Manila 1002 (Philippines); Li, M.-H., E-mail: mhli@cycu.edu.t [R and D Center for Membrane Technology and Department of Chemical Engineering, Chung Yuan Christian University, Chung Li 32023, Taiwan (China)

    2010-04-15

    This report presents a new set of heat capacity data for the system piperazine left brace(PZ) + 2-amino-2-methyl-1-propanol (AMP) + water (H{sub 2}O)right brace, measured using the differential scanning calorimetry technique, over the temperature range 303.2 K to 353.2 K and at fourteen (14) different concentrations in which the water mole fractions, x{sub 3}'s, were fixed at 0.60, 0.70, 0.80, and 0.90. Heat capacity for the binary system left bracePZ (1) + AMP (2)right brace at x{sub 1} = 0.05, 0.10, 0.15, and 0.20 were, likewise, measured to generate parameters necessary in the Redlich-Kister-type model, which was used to estimate excess molar heat capacities. Such estimates were then used to predict the values of the molar heat capacity at the corresponding sets of temperature and concentration. The predicted values were subsequently compared against the measured values and the results are satisfactory.

  1. Unprecedented Integral-Free Debye Temperature Formulas: Sample Applications to Heat Capacities of ZnSe and ZnTe

    National Research Council Canada - National Science Library

    R. Pässler

    2017-01-01

    Detailed analytical and numerical analyses are performed for combinations of several complementary sets of measured heat capacities, for ZnSe and ZnTe, from the liquid-helium region up to 600 K. The isochoric (harmonic...

  2. Capacity Measurement with the UIC 406 Capacity Method

    DEFF Research Database (Denmark)

    Landex, Alex; Schittenhelm, Bernd; Kaas, Anders H.

    2008-01-01

    This article describes the fast and effective UIC 406 method for calculating capacity consumption on railway lines. It is possible to expound the UIC 406 method in different ways which can lead to different capacity consumptions. Therefore, this article describes how the methodology is expounded ...

  3. Molecular mobility, thermodynamics and stability of griseofulvin's ultraviscous and glassy states from dynamic heat capacity.

    Science.gov (United States)

    Tombari, E; Presto, S; Johari, G P; Shanker, Ravi M

    2008-04-01

    To determine the calorimetric relaxation time needed for modeling griseofulvin's stability against crystallization during storage. Both temperature-modulated and unmodulated scanning calorimetry have been used to determine the heat capacity of griseofulvin in the glassy and melt state. The calorimetric relaxation time, tau cal, of its melt varies with the temperature T according to the relation, tau cal [s] = 10(-13.3) exp [2, 292 /(T[K] - 289.5)] , and the distribution of relaxation times parameter is 0.67. The unrelaxed heat capacity of the griseofulvin melt is equal to its vibrational heat capacity. Griseofulvin neither crystallizes on heating to 373 K at 1 K/h rate, nor on cooling. Molecular mobility and vibrational heat capacity measured here are more reliable for modeling a pharmaceutical's stability against crystallization than the currently used kinetics-thermodynamics relations, and molecular mobility in the (fixed structure) glassy state is much greater than the usual extrapolation from the melt state yields. Molecular relaxation time of the glassy state of griseofulvin is about 2 months at 298 K, and longer at lower temperatures. It would spontaneously increase with time. If the long-range motions alone were needed for crystallization, griseofulvin would become more stable against crystallization during storage.

  4. Anomalous dependence of the heat capacity of supercooled water on pressure and temperature

    Directory of Open Access Journals (Sweden)

    I.A. Stepanov

    2014-01-01

    Full Text Available In some papers, dependences of the isobaric heat capacity of water versus pressure and temperature were obtained. It is shown that these dependences contradict both the dependence of heat capacity on temperature for supercooled water, and an important thermodynamic equation for the dependence of heat capacity on pressure. A possible explanation for this contradiction is proposed.

  5. Information capacities of quantum measurement channels

    Science.gov (United States)

    Holevo, A. S.

    2013-03-01

    We study the relation between the unassisted and entanglement-assisted classical capacities C and Cea of entanglement-breaking channels. We argue that the gain of entanglement assistance Cea/C > 1 generically for measurement channels with unsharp observables; in particular for the measurements with pure posterior states the information loss in the entanglement-assisted protocol is zero, resulting in an arbitrarily large gain for very noisy or weak signal channels. This is illustrated by examples of continuous observables corresponding to state tomography in finite dimensions and heterodyne measurement. In contrast, state preparations are characterized by the property of having no gain of entanglement assistance, Cea/C = 1.

  6. Low-temperature heat capacity and thermodynamic functions of vitamin B{sub 12}

    Energy Technology Data Exchange (ETDEWEB)

    Knyazev, A.V., E-mail: knyazevav@gmail.com; Smirnova, N.N.; Plesovskikh, A.S.; Shushunov, A.N.; Knyazeva, S.S.

    2014-04-01

    Graphical abstract: - Highlights: • Temperature dependence of heat capacity of vitamin B{sub 12} has been measured by precision adiabatic vacuum calorimetry. • The thermodynamic functions of the vitamin B{sub 12} have been determined for the range from T → 0 to 343 K. • The character of heterodynamics of structure was detected. • The thermal stability of cyanocobalamin was studied by differential scanning calorimetry. - Abstract: In the present work temperature dependence of heat capacity of vitamin B{sub 12} (cyanocobalamin) has been measured for the first time in the range from 6 to 343 K by precision adiabatic vacuum calorimetry. Based on the experimental data, the thermodynamic functions of the vitamin B{sub 12}, namely, the heat capacity, enthalpy H°(T) − H°(0), entropy S°(T) − S°(0) and Gibbs function G°(T) − H°(0) have been determined for the range from T → 0 to 343 K. The value of the fractal dimension D in the function of multifractal generalization of Debye's theory of the heat capacity of solids was estimated and the character of heterodynamics of structure was detected. The thermal stability of cyanocobalamin was also studied by differential scanning calorimetry.

  7. Heat Capacity Uncertainty Calculation for the Eutectic Mixture of Biphenyl/Diphenyl Ether Used as Heat Transfer Fluid: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Gomez, J. C.; Glatzmaier, G. C.; Mehos, M.

    2012-09-01

    The main objective of this study was to calculate the uncertainty at 95% confidence for the experimental values of heat capacity of the eutectic mixture of biphenyl/diphenyl ether (Therminol VP-1) determined from 300 to 370 degrees C. Twenty-five samples were evaluated using differential scanning calorimetry (DSC) to obtain the sample heat flow as a function of temperature. The ASTM E-1269-05 standard was used to determine the heat capacity using DSC evaluations. High-pressure crucibles were employed to contain the sample in the liquid state without vaporizing. Sample handling has a significant impact on the random uncertainty. It was determined that the fluid is difficult to handle, and a high variability of the data was produced. The heat capacity of Therminol VP-1 between 300 and 370 degrees C was measured to be equal to 0.0025T+0.8672 with an uncertainty of +/- 0.074 J/g.K (3.09%) at 95% confidence with T (temperature) in Kelvin.

  8. Heat capacity and Joule-Thomson coefficient of selected n-alkanes at 0.1 and 10 MPa in broad temperature ranges

    DEFF Research Database (Denmark)

    Regueira Muñiz, Teresa; Varzandeh, Farhad; Stenby, Erling Halfdan

    2017-01-01

    Isobaric heat capacity of six n-alkanes, i.e. n-hexane, n-octane, n-decane, n-dodecane, n-tetradecane and n-hexadecane, was determined with a Calvet type differential heat-flux calorimeter at 0.1 and 10 MPa in a broad temperature range. The measured isobaric heat capacity data were combined...

  9. Cold drink ingestion improves exercise endurance capacity in the heat.

    Science.gov (United States)

    Lee, Jason K W; Shirreffs, Susan M; Maughan, Ronald J

    2008-09-01

    To investigate the effect of drink temperature on cycling capacity in the heat. On two separate trials, eight males cycled at 66 +/- 2% VO2peak (mean +/- SD) to exhaustion in hot (35.0 +/- 0.2 degrees C) and humid (60 +/- 1%) environments. Participants ingested three 300-mL aliquots of either a cold (4 degrees C) or a warm (37 degrees C) drink during 30 min of seated rest before exercise and 100 mL of the same drink every 10 min during exercise. Rectal and skin temperatures, heart rate, and sweat rate were recorded. Ratings of thermal sensation and perceived exertion were assessed. Exercise time was longer (P drink (63.8 +/- 4.3 min) than with the warm drink (52.0 +/- 4.1 min). Rectal temperature fell by 0.5 +/- 0.1 degrees C (P drinks. There was no effect of drink temperature on mean skin temperature at rest (P = 0.870), but mean skin temperature was lower from 20 min during exercise with ingestion of the cold drink than with the warm drink (P drink than with the warm drink (P Drink temperature influenced sweat rate (1.22 +/- 0.34 and 1.40 +/- 0.41 L x h(-1) for the cold and the warm drink, respectively; P drink was ingested. Compared with a drink at 37 degrees C, the ingestion of a cold drink before and during exercise in the heat reduced physiological strain (reduced heat accumulation) during exercise, leading to an improved endurance capacity (23 +/- 6%).

  10. Thermodynamic functions of ZrW2O8 from its heat capacity

    Science.gov (United States)

    Ji, FengMin; Dai, XianXi; Stevens, R.; Goates, J. B.

    2012-04-01

    It is interesting to maximize the amount of information we can obtain from one experiment on a single sample. In obtaining all the thermodynamic properties of some materials from their experimental heat capacity data only, we aim to get the temperature- independent energy spectrum. However, all the practical measured energy spectra depend on the temperature of experiments. One promising method to obtain the temperature-independent energy spectrum is to solve the so-called specific heat-phonon spectrum inversion (SPI) problem. Here we show, by developing a new practical solution method of SPI, the phonon spectrum of the negative thermal expansion material ZrW2O8 is obtained. This phonon spectrum is temperature- independent and almost method independent. Hence all the thermodynamic properties of ZrW2O8, such as thermodynamic potential, entropy, Helmholtz free energy, etc. are obtained by heat capacity only.

  11. Study of heating capacity of focused IR light soldering systems.

    Science.gov (United States)

    Anguiano, C; Félix, M; Medel, A; Bravo, M; Salazar, D; Márquez, H

    2013-10-07

    An experimental study about four optical setups used for developing a Focused IR Light Soldering System (FILSS) for Surface Mount Technology (SMT) lead-free electronic devices specifically for Ball Grid Arrays (BGA) is presented. An analysis of irradiance and infrared thermography at BGA surface is presented, as well as heat transfer by radiation and conduction process from the surface of the BGA to the solder balls. The results of this work show that the heating provided by our proposed optical setups, measured at the BGA under soldering process, meets the high temperature and uniform thermal distribution requirements, which are defined by the reflow solder method for SMT devices.

  12. Modeling the Heat Capacity of Spider Silk Inspired Di-block Copolymers

    Science.gov (United States)

    Huang, W.; Krishnaji, S.; Kaplan, D.; Cebe, P.

    2011-03-01

    We synthesized and characterized a new family of di-block copolymers based on the amino acid sequences of Nephila clavipes major ampulate dragline spider silk, having the form HABn and HBAn (n=1-6), comprising an alanine-rich hydrophobic block, A, a glycine-rich hydrophilic block, B, and a histidine tag, H. Using temperature modulated differential scanning calorimetry (TMDSC), we captured the effect of bound water acting as a plasticizer for copolymer films which had been cast from water solution and dried. We determined the water content by thermogravimetry and used the weight loss vs. temperature to correct the mass in TMDSC experiments. Our result shows that non-freezing bound water has a strong plasticization effect which lowers the onset of the glass transition by about 10circ; C. The reversing heat capacities, Cp(T), for temperatures below and above the glass transition were also characterized by TMDSC. We then calculated the solid state heat capacities of our novel block copolymers below the glass transition (Tg) based on the vibrational motions of the constituent poly(amino acid)s, whose heat capacities are known from the ATHAS Data Bank. Excellent agreement was found between the measured and calculated values of the heat capacity, showing that this model can serve as a standard method to predict the solid state Cp for other biologically inspired block copolymers. Support was provided from the NSF CBET-0828028 and the MRI Program under DMR-0520655 for thermal analysis instrumentation.

  13. Vibrational Spectra and Heat Capacity of Methane, and the Speed of Sound

    Science.gov (United States)

    Tennis, Ronald; Bailey, Ryan; Henderson, Giles

    2000-12-01

    A two-part physical chemistry laboratory experiment is described in which students evaluate statistical mechanical theory by comparing a measured speed of sound and heat capacity with values predicted from vibrational spectra. In part 1 students measure the IR spectrum of CH4(g) and the Raman spectrum of CH4(l) to determine quantized vibrational energy spacings. Strong Raman scattering of a pulsed nitrogen laser beam is observed with a liquid methane sample in a custom cryogenic cell constructed from two side-arm test tubes and a length of Pyrex tube. These data are used with the statistical mechanics of a harmonic oscillator to calculate vibrational heat capacities and CP/CV; of CH4(g) and the speed of sound in CH4(g). In part 2, the predicted speed of sound is compared with an experimental value measured with a simple acoustic resonance cavity (Kundt's tube) exhausted to a Bunsen burner.

  14. An experimental study of the enhanced heating capacity of an electric heat pump (EHP) using the heat recovered from a gas engine generator

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Cheol Min; Chang, Se Dong [HAC R and D Laboratory, LG Electronics, 327-23 Gasan-Dong, Geumcheon-gu, Seoul 153-802 (Korea); Lee, Jaekeun; Hwang, Yujin [School of Mechanical Engineering, Pusan National University, San 30, Changjeon-Dong, Keumjeong-Ku, Busan 609-735 (Korea)

    2009-11-15

    This paper is concerned with the effect of recovered heat on the heating capacity of an Electric Heat Pump (EHP), which is supplied with electric power and recovered heat from a gas engine generator system. Two methods of supplying recovery heat are examined: (i) to the refrigerant with the discharge line heat exchanger (HEX), and (ii) to the refrigerant of the evaporator with the sub-evaporator. Heating capacity, input power and coefficient of performance (COP) were investigated and compared for each heat recovery method. Conclusively, we found that the second method was most reasonable to recover wasted heat and increased system COP by 215%. (author)

  15. Excess heat capacity and entropy of mixing along the chlorapatite-fluorapatite binary join

    Science.gov (United States)

    Dachs, Edgar; Harlov, Daniel; Benisek, Artur

    2010-10-01

    The heat capacity at constant pressure, C p, of chlorapatite [Ca5(PO4)3Cl - ClAp], and fluorapatite [Ca5(PO4)3F - FAp], as well as of 12 compositions along the chlorapatite-fluorapatite join have been measured using relaxation calorimetry [heat capacity option of the physical properties measurement system (PPMS)] and differential scanning calorimetry (DSC) in the temperature range 5-764 K. The chlor-fluorapatites were synthesized at 1,375-1,220°C from Ca3(PO4)2 using the CaF2-CaCl2 flux method. Most of the chlor-fluorapatite compositions could be measured directly as single crystals using the PPMS such that they were attached to the sample platform of the calorimeter by a crystal face. However, the crystals were too small for the crystal face to be polished. In such cases, where the sample coupling was not optimal, an empirical procedure was developed to smoothly connect the PPMS to the DSC heat capacities around ambient T. The heat capacity of the end-members above 298 K can be represented by the polynomials: C {p/ClAp} = 613.21 - 2,313.90 T -0.5 - 1.87964 × 107 T -2 + 2.79925 × 109 T -3 and C {p/FAp} = 681.24 - 4,621.73 × T -0.5 - 6.38134 × 106 T -2 + 7.38088 × 108 T -3 (units, J mol-1 K-1). Their standard third-law entropy, derived from the low-temperature heat capacity measurements, is S° = 400.6 ± 1.6 J mol-1 K-1 for chlorapatite and S° = 383.2 ± 1.5 J mol-1 K-1 for fluorapatite. Positive excess heat capacities of mixing, Δ C {p/ex}, occur in the chlorapatite-fluorapatite solid solution around 80 K (and to a lesser degree at 200 K) and are asymmetrically distributed over the join reaching a maximum of 1.3 ± 0.3 J mol-1 K-1 for F-rich compositions. They are significant at these conditions exceeding the 2 σ-uncertainty of the data. The excess entropy of mixing, Δ S ex, at 298 K reaches positive values of 3-4 J mol-1 K-1 in the F-rich portion of the binary, is, however, not significantly different from zero across the join within its 2 σ-uncertainty.

  16. Transient response of a high-capacity heat pipe for Space Station Freedom

    Science.gov (United States)

    Ambrose, J. H.; Holmes, H. R.

    1991-01-01

    High-capacity heat pipe radiator panels have been proposed as the primary means of heat rejection for Space Station Freedom. In this system, the heat pipe would interface with the thermal bus condensers. Changes in system heat load can produce large temperature and heat load variations in individual heat pipes. Heat pipes could be required to start from an initially cold state, with heat loads temporarily exceeding their low-temperature transport capacity. The present research was motivated by the need for accurate prediction of such transient operating conditions. In this work, the cold startup of a 6.7-meter long high-capacity heat pipe is investigated experimentally and analytically. A transient thermohydraulic model of the heat pipe was developed which allows simulation of partially-primed operation. The results of cold startup tests using both constant temperature and constant heat flux evaporator boundary conditions are shown to be in good agreement with predicted transient response.

  17. Large-scale calculations of gas phase thermochemistry : Enthalpy of formation, standard entropy, and heat capacity

    OpenAIRE

    Ghahremanpour, Mohammad M.; van Maaren, Paul J.; Ditz, Jonas C.; Lindh, Roland; van der Spoel, David

    2016-01-01

    Large scale quantum calculations for molar enthalpy of formation (Delta(f) H-0), standard entropy (S-0), and heat capacity (C-V) are presented. A large data set may help to evaluate quantum thermochemistry tools in order to uncover possible hidden shortcomings and also to find experimental data that might need to be reinvestigated, indeed we list and annotate approximately 200 problematic thermochemistry measurements. Quantum methods systematically underestimate S-0 for flexible molecules in ...

  18. Measurement and Evaluation of Heating Performance of Heat Pump Systems Using Wasted Heat from Electric Devices for an Electric Bus

    Directory of Open Access Journals (Sweden)

    Moo-Yeon Lee

    2012-03-01

    Full Text Available The objective of this study is to investigate heating performance characteristics of a coolant source heat pump using the wasted heat from electric devices for an electric bus. The heat pump, using R-134a, is designed for heating a passengers’ compartment by using discharged energy from the coolant of electric devices, such as motors and inverters of the electric bus. The heating performance of the heat pump was tested by varying the operating parameters, such as outdoor temperature and volume flow rate of the coolant water of the electrical devices. Heating capacity, compressor work, and heating COP were measured; their behaviors with regard to the parameters were observed. Experimental results showed that heating COP increased with decrease of outdoor temperature, from 20.0 °C to 0 °C, and it observed to be 3.0 in the case of 0 °C outdoor temperature. The observed characteristics of the heating COP suggest that the heat pump is applicable as the cabin heater of an electric vehicle, which is limited by short driving range.

  19. Measured Performance of a Low Temperature Air Source Heat Pump

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, R. K. [Johnson Research LLC, Pueblo West, CO (United States)

    2013-09-01

    A 4-ton Low Temperature Heat Pump (LTHP) manufactured by Hallowell International was installed in a residence near New Haven, Connecticut and monitored over two winters of operation. After attending to some significant service issues, the heat pump operated as designed. This report should be considered a review of the dual compressor 'boosted heat pump' technology. The Low Temperature Heat Pumpsystem operates with four increasing levels of capacity (heat output) as the outdoor temperature drops. The system was shown to select capacity correctly, supplying the appropriate amount of heat to the house across the full range of outdoor temperatures. The system's Coefficient of Performance (Seasonal COP, or SCOP) over two entire winters was calculated, based on measured data, to be 3.29over the first winter and 2.68 over the second winter. A second seasonal efficiency calculation by a different method yielded a SCOP of 2.78 for the first winter and 2.83 for the second winter. This second seasonal efficiency calculation was determined by comparing measured heat pump energy use to the in situ energy use with resistance heat alone. This method is the ratio of the slopes of thedaily energy use load lines.

  20. Temperature fluctuation and heat capacity in relativistic heavy-ion collisions

    CERN Document Server

    Ma, Guo Liang; Chen Jin Gen; He Ze-Jun; Long Jia-Li; Lu Zhao-Hui; Ma Yu-Gang; Sá Ben-Hao; Shen Wen-Qing; Wang Kun; Wei Yi-Bin; Zhang Hu-Yong; Zhong Chen

    2004-01-01

    We used LUCIAE3.0 model to simulate the Pb+Pb and C+C in SPS energy. The heat capacity was then extracted from event-by-event temperature fluctuation. It is found that the heat capacity per hadron multiplicity decreases with the increasing of beam energy and impact parameter for a given reaction system. While the hadron mass increases, the heat capacity per hadron multiplicity rises. In addition, we found that, for a given hadron, the heat capacity per hadron multiplicity is almost the same regardless of the reaction system. Some discussions were also given.

  1. Decoding heat capacity features from the energy landscape

    Science.gov (United States)

    Wales, David J.

    2017-03-01

    A general scheme is derived to connect transitions in configuration space with features in the heat capacity. A formulation in terms of occupation probabilities for local minima that define the potential energy landscape provides a quantitative description of how contributions arise from competition between different states. The theory does not rely on a structural interpretation for the local minima, so it is equally applicable to molecular energy landscapes and the landscapes defined by abstract functions. Applications are presented for low-temperature solid-solid transitions in atomic clusters, which involve just a few local minima with different morphologies, and for cluster melting, which is driven by the landscape entropy associated with the more numerous high-energy minima. Analyzing these features in terms of the balance between states with increasing and decreasing occupation probabilities provides a direct interpretation of the underlying transitions. This approach enables us to identify a qualitatively different transition that is caused by a single local minimum associated with an exceptionally large catchment volume in configuration space for a machine learning landscape.

  2. Measuring Specific Heats at High Temperatures

    Science.gov (United States)

    Vandersande, Jan W.; Zoltan, Andrew; Wood, Charles

    1987-01-01

    Flash apparatus for measuring thermal diffusivities at temperatures from 300 to 1,000 degrees C modified; measures specific heats of samples to accuracy of 4 to 5 percent. Specific heat and thermal diffusivity of sample measured. Xenon flash emits pulse of radiation, absorbed by sputtered graphite coating on sample. Sample temperature measured with thermocouple, and temperature rise due to pulse measured by InSb detector.

  3. A Heat Vulnerability Index: Spatial Patterns of Exposure, Sensitivity and Adaptive Capacity for Santiago de Chile

    Science.gov (United States)

    Palme, Massimo; de la Barrera, Francisco

    2016-01-01

    Climate change will worsen the high levels of urban vulnerability in Latin American cities due to specific environmental stressors. Some impacts of climate change, such as high temperatures in urban environments, have not yet been addressed through adaptation strategies, which are based on poorly supported data. These impacts remain outside the scope of urban planning. New spatially explicit approaches that identify highly vulnerable urban areas and include specific adaptation requirements are needed in current urban planning practices to cope with heat hazards. In this paper, a heat vulnerability index is proposed for Santiago, Chile. The index was created using a GIS-based spatial information system and was constructed from spatially explicit indexes for exposure, sensitivity and adaptive capacity levels derived from remote sensing data and socio-economic information assessed via principal component analysis (PCA). The objective of this study is to determine the levels of heat vulnerability at local scales by providing insights into these indexes at the intra city scale. The results reveal a spatial pattern of heat vulnerability with strong variations among individual spatial indexes. While exposure and adaptive capacities depict a clear spatial pattern, sensitivity follows a complex spatial distribution. These conditions change when examining PCA results, showing that sensitivity is more robust than exposure and adaptive capacity. These indexes can be used both for urban planning purposes and for proposing specific policies and measures that can help minimize heat hazards in highly dynamic urban areas. The proposed methodology can be applied to other Latin American cities to support policy making. PMID:27606592

  4. Temperature dependence of electronic heat capacity in Holstein model of DNA

    Science.gov (United States)

    Fialko, N.; Sobolev, E.; Lakhno, V.

    2016-04-01

    The dynamics of charge migration was modeled to calculate temperature dependencies of its thermodynamic equilibrium values such as energy and electronic heat capacity in homogeneous adenine fragments. The energy varies from nearly polaron one at T ∼ 0 to midpoint of the conductivity band at high temperatures. The peak on the graph of electronic heat capacity is observed at the polaron decay temperature.

  5. Saturated-liquid heat capacity of organic compounds: new empirical correlation model

    Directory of Open Access Journals (Sweden)

    DUSAN K. GROZDANIC

    2004-03-01

    Full Text Available A new saturated-liquid heat capacity model is recommended. This model is tested and compared with the known polynomial and quasi-polynomial models on 39 sets with 1453 experimental heat capacity data. The obtained results indicate that the new model is better then the existing models, especially near the critical point.

  6. Droplet Evaporator For High-Capacity Heat Transfer

    Science.gov (United States)

    Valenzuela, Javier A.

    1993-01-01

    Proposed heat-exchange scheme boosts heat transfer per unit area. Key component is generator that fires uniform size droplets of subcooled liquid at hot plate. On impact, droplets spread out and evaporate almost instantly, removing heat from plate. In practice, many generator nozzles arrayed over evaporator plate.

  7. Heat capacity and thermodynamic functions of thulium orthophosphate TmPO4 in the range of 10-1350 K

    Science.gov (United States)

    Ryumin, M. A.; Gurevich, V. M.; Khoroshilov, A. V.; Tyurin, A. V.; Gavrichev, K. S.

    2017-12-01

    The heat capacity of TmPO4 in temperature ranges of 9.11-346.05 and 304.6-1344.6 K is measured via adiabatic and differential scanning calorimetry, respectively. The measurement data are used to calculate the temperature dependences of the heat capacity, entropy, change in enthalpy, and reduced Gibbs energy of TmPO4 in the range of 10-1344 K. The Gibbs energy of formation of thulium orthophosphate from elements Δf G 0(298.15 K) is determined.

  8. Heat capacity for systems with excited-state quantum phase transitions

    Energy Technology Data Exchange (ETDEWEB)

    Cejnar, Pavel; Stránský, Pavel, E-mail: stransky@ipnp.troja.mff.cuni.cz

    2017-03-18

    Heat capacities of model systems with finite numbers of effective degrees of freedom are evaluated using canonical and microcanonical thermodynamics. Discrepancies between both approaches, which are observed even in the infinite-size limit, are particularly large in systems that exhibit an excited-state quantum phase transition. The corresponding irregularity of the spectrum generates a singularity in the microcanonical heat capacity and affects smoothly the canonical heat capacity. - Highlights: • Thermodynamics of systems with excited-state quantum phase transitions • ESQPT-generated singularities of the microcanonical heat capacity • Non-monotonous dependences of the canonical heat capacity • Discord between canonical and microcanonical pictures in the infinite-size limit.

  9. Basic measurements on a multiple heat pipe

    Science.gov (United States)

    Rohner, P.; Schippl, K.

    1982-04-01

    A multiple heat pipe which is a specially formed long heat pipe that fulfills the function of several single heat pipes was studied. The suitability of this arrangement for a heat exchanger was investigated. Several laboratory models were manufactured from corrugated tubes and their behavior was measured. Results show that the serpentine model exhibits the expected heat exchange properties. When subjected to severe operating conditions, the pipes remain operational, although somewhat limited in performance. The results are in function of the nature of the exchange media (air-air, air-water, water-water). This corrugated heat pipe design shows good promise for successful further development into an air-air heat exchanger.

  10. Characterization of Molten CZT Using Thermal Conductivity and Heat Capacity

    Energy Technology Data Exchange (ETDEWEB)

    Nero, Franco [Y-12 National Security Complex, Oak Ridge, TN (United States); Jackson, Maxx [Y-12 National Security Complex, Oak Ridge, TN (United States); Stowe, Ashley [Y-12 National Security Complex, Oak Ridge, TN (United States)

    2017-10-10

    To compare thermal conductivity of a polycrystalline semiconductor to the single crystal semiconductor using thermo-physical data acquired from Simultaneous Thermal Analysis and Transient Plane Source heating.

  11. A heat capacity anomaly of the superconducting transition in a ferromagnetic superconductor UGe{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Tateiwa, Naoyuki; Kobayashi, Tatsuo C.; Amaya, Kiichi; Haga, Yoshinori; Settai, Rikio; Onuki, Yoshichika

    2003-05-15

    We performed the heat capacity, C(T), measurement under high pressure on a ferromagnetic superconductor UGe{sub 2}, in order to study the pressure dependence of the anomaly in C(T) associated with the superconducting transition. A clear peak appears only around a critical pressure P{sub c}* where an another transition temperature T* becomes 0 K. This result suggests that a bulk superconducting phase exists in the narrower pressure region around P{sub c}* than those clarified by previous studies.

  12. Mössbauer and heat capacity studies of ErZnSn2

    Directory of Open Access Journals (Sweden)

    Łątka Kazimierz

    2017-06-01

    Full Text Available Heat capacity results obtained for the intermetallic compound ErZnSn2 were re-analysed to also consider, apart from the classical Debye model, the anharmonicity of the crystal lattice and the proper set of Einstein modes. The 119mSn Mössbauer technique was applied to derive the hyperfine interaction parameters characteristic of the two inequivalent crystallographic Sn sites in the compound studied. Quadrupole interaction constants, as measured by 119mSn Mössbauer spectroscopy, allowed for estimations of Vzz components of the electric field gradient tensor that exist at both Sn sites in the discussed compound.

  13. Measures for Increasing of Company’s Production Capacity

    Directory of Open Access Journals (Sweden)

    Ernesta Žikevičiūtė

    2012-07-01

    Full Text Available Production capacity improvements are poorly explored areas of economic literature and the existing methods are difficult to apply. For this reason, the organization has only a superficial analysis of capacity, but after all this time, each production company had to improve the production capacity for the market economy and the most economical use of production factors.This article explores the company’s production capacity for better use of tools. It also presents the capacity of their concept, establishment, evaluates the factors leading to their production capacity, for developing efficiency measures and model presentation.Article in Lithuanian

  14. Effect of crystalline electric field on heat capacity of LnBaCuFeO5 (Ln = Gd, Ho, Yb)

    Science.gov (United States)

    Lal, Surender; Mukherjee, K.; Yadav, C. S.

    2018-02-01

    Structural, magnetic and thermodynamic properties of layered perovskite compounds LnBaCuFeO5 (Ln = Ho, Gd, Yb) have been investigated. Unlike the iso-structural compound YBaCuFeO5, which shows commensurate antiferromagnetic to incommensurate antiferromagnetic ordering below ∼200 K, the studied compounds do not show any magnetic transition in measured temperature range of 2-350 K. The high temperature heat capacity of the compounds is understood by employing contributions from both optical and acoustic phonons. At low temperature, the observed upturn in the heat capacity is attributed to the Schottky anomaly. The magnetic field dependent heat capacity shows the variation in position of the anomaly with temperature, which appears due to the removal of ground state degeneracy of the rare earth ions, by the crystalline electric field.

  15. Heat and moisture exchange capacity of the upper respiratory tract and the effect of tracheotomy breathing on endotracheal climate

    NARCIS (Netherlands)

    Scheenstra, R.J.; Muller, S.H.; Vincent, A.; Hilgers, F.J.M.

    2011-01-01

    Background. The aim of this study was to assess the heat and moisture exchange (HME) capacity of the upper respiratory tract and the effect of tracheotomy breathing on endotracheal climate in patients with head and neck cancer. Methods. We plotted the subglottic temperature and humidity measurements

  16. HEAT AND MOISTURE EXCHANGE CAPACITY OF THE UPPER RESPIRATORY TRACT AND THE EFFECT OF TRACHEOTOMY BREATHING ON ENDOTRACHEAL CLIMATE

    NARCIS (Netherlands)

    Scheenstra, Renske J.; Muller, Sara H.; Vincent, Andrew; Hilgers, Frans J. M.

    2011-01-01

    Background. The aim of this study was to assess the heat and moisture exchange (HME) capacity of the upper respiratory tract and the effect of tracheotomy breathing on endotracheal climate in patients with head and neck cancer. Methods. We plotted the subglottic temperature and humidity measurements

  17. Determination of the thermal conductivity and specific heat capacity of neem seeds by inverse problem method

    Directory of Open Access Journals (Sweden)

    S.N. Nnamchi

    2010-01-01

    Full Text Available Determination of the thermal conductivity and the specific heat capacity of neem seeds (Azadirachta indica A. Juss usingthe inverse method is the main subject of this work. One-dimensional formulation of heat conduction problem in a spherewas used. Finite difference method was adopted for the solution of the heat conduction problem. The thermal conductivityand the specific heat capacity were determined by least square method in conjunction with Levenberg-Marquardt algorithm.The results obtained compare favourably with those obtained experimentally. These results are useful in the analysis ofneem seeds drying and leaching processes.

  18. Magnetocaloric effect and the heat capacity of ferrimagnetic nanosystems in magnetic fluids

    Science.gov (United States)

    Korolev, V. V.; Aref'ev, I. M.; Ramazanova, A. G.

    2007-10-01

    The specific heat capacity of a magnetite-based magnetic fluid and changes in the magnetic part of the molar heat capacity of its magnetic phase in magnetic fields of 0 0.7 T were determined calorimetrically over the temperature range 288 353 K. The temperature dependence of changes in the magnetic part of entropy in an applied magnetic field was calculated. It was found that the field dependence of heat capacity had a maximum in fields of 0.3 0.4 T, and the temperature dependences of changes in the magnetic part of heat capacity Δ C p ( H) and entropy Δ S m( H) had maxima at the magnetic phase transition temperature.

  19. Solvation thermodynamics and heat capacity of polar and charged solutes in water.

    Science.gov (United States)

    Sedlmeier, Felix; Netz, Roland R

    2013-03-21

    The solvation thermodynamics and in particular the solvation heat capacity of polar and charged solutes in water is studied using atomistic molecular dynamics simulations. As ionic solutes we consider a F(-) and a Na(+) ion, as an example for a polar molecule with vanishing net charge we take a SPC/E water molecule. The partial charges of all three solutes are varied in a wide range by a scaling factor. Using a recently introduced method for the accurate determination of the solvation free energy of polar solutes, we determine the free energy, entropy, enthalpy, and heat capacity of the three different solutes as a function of temperature and partial solute charge. We find that the sum of the solvation heat capacities of the Na(+) and F(-) ions is negative, in agreement with experimental observations, but our results uncover a pronounced difference in the heat capacity between positively and negatively charged groups. While the solvation heat capacity ΔC(p) stays positive and even increases slightly upon charging the Na(+) ion, it decreases upon charging the F(-) ion and becomes negative beyond an ion charge of q = -0.3e. On the other hand, the heat capacity of the overall charge-neutral polar solute derived from a SPC/E water molecule is positive for all charge scaling factors considered by us. This means that the heat capacity of a wide class of polar solutes with vanishing net charge is positive. The common ascription of negative heat capacities to polar chemical groups might arise from the neglect of non-additive interaction effects between polar and apolar groups. The reason behind this non-additivity is suggested to be related to the second solvation shell that significantly affects the solvation thermodynamics and due to its large spatial extent induces quite long-ranged interactions between solvated molecular parts and groups.

  20. Calculation of heat capacities of light and heavy water by path-integral molecular dynamics.

    Science.gov (United States)

    Shiga, Motoyuki; Shinoda, Wataru

    2005-10-01

    As an application of atomistic simulation methods to heat capacities, path-integral molecular dynamics has been used to calculate the constant-volume heat capacities of light and heavy water in the gas, liquid, and solid phases. While the classical simulation based on conventional molecular dynamics has estimated the heat capacities too high, the quantum simulation based on path-integral molecular dynamics has given reasonable results based on the simple point-charge/flexible potential model. The calculated heat capacities (divided by the Boltzmann constant) in the quantum simulation are 3.1 in the vapor H2O at 300 K, 6.9 in the liquid H2O at 300 K, and 4.1 in the ice Ih H2O at 250 K, respectively, which are comparable to the experimental data of 3.04, 8.9, and 4.1, respectively. The quantum simulation also reproduces the isotope effect. The heat capacity in the liquid D2O has been calculated to be 10% higher than that of H2O, while it is 13% higher in the experiment. The results demonstrate that the path-integral simulation is a promising approach to quantitatively evaluate the heat capacities for molecular systems, taking account of quantum-mechanical vibrations as well as strongly anharmonic motions.

  1. Linear heating system for measurement of thermoluminescence ...

    Indian Academy of Sciences (India)

    A linear heating system is developed using a 8031/51 microcontroller for the measurement of thermoluminescence (TL) in alkali halides and other related compounds. This system also measures the temperature and the amount of light emitted by the sample for TL studies.

  2. Determination of Specific Heat Capacity on Composite Shape-Stabilized Phase Change Materials and Asphalt Mixtures by Heat Exchange System.

    Science.gov (United States)

    Ma, Biao; Zhou, Xue-Yan; Liu, Jiang; You, Zhanping; Wei, Kun; Huang, Xiao-Feng

    2016-05-19

    Previous research has shown that composite shape-stabilized phase change material (CPCM) has a remarkable capacity for thermal storage and stabilization, and it can be directly applied to highway construction without leakage. However, recent studies on temperature changing behaviors of CPCM and asphalt mixture cannot intuitively reflect the thermoregulation mechanism and efficiency of CPCM on asphalt mixture. The objective of this paper is to determine the specific heat capacity of CPCM and asphalt mixtures mixed with CPCM using the heat exchange system and the data acquisition system. Studies have shown that the temperature-rise curve of 5 °C CPCM has an obvious temperature plateau, while an asphalt mixture mixed with 5 °C CPCM does not; with increasing temperature, the specific heat capacities of both 5 °C CPCM and asphalt mixture first increase and then decrease, while the variation rate of 5 °C CPCM is larger than that of the asphalt mixture, and the maximum specific heat capacity of 5 °C CPCM appears around the initial phase change temperature. It is concluded that the temperature intervals of 5 °C CPCM are -18 °C-7 °C, 7 °C-25 °C and 25 °C-44 °C, respectively, and that of the asphalt mixture are -18 °C~10 °C, -10 °C~5 °C and 5 °C~28 °C. A low dosage of 5 °C CPCM has little influence on the specific heat capacity of asphalt mixture. Finally, the functions of specific heat capacities and temperature for CPCM and asphalt mixture mixed with CPCM were recommended by the sectional regression method.

  3. Influence of heat treatment on antioxidant capacity and (poly)phenolic compounds of selected vegetables.

    Science.gov (United States)

    Juániz, Isabel; Ludwig, Iziar A; Huarte, Estibaliz; Pereira-Caro, Gema; Moreno-Rojas, Jose Manuel; Cid, Concepción; De Peña, María-Paz

    2016-04-15

    The impact of cooking heat treatments (frying in olive oil, frying in sunflower oil and griddled) on the antioxidant capacity and (poly)phenolic compounds of onion, green pepper and cardoon, was evaluated. The main compounds were quercetin and isorhamnetin derivates in onion, quercetin and luteolin derivates in green pepper samples, and chlorogenic acids in cardoon. All heat treatments tended to increase the concentration of phenolic compounds in vegetables suggesting a thermal destruction of cell walls and sub cellular compartments during the cooking process that favor the release of these compounds. This increase, specially that observed for chlorogenic acids, was significantly correlated with an increase in the antioxidant capacity measured by DPPH (r=0.70). Griddled vegetables, because of the higher temperature applied during treatment in comparison with frying processes, showed the highest amounts of phenolic compounds with increments of 57.35%, 25.55% and 203.06% compared to raw onion, pepper and cardoon, respectively. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Specific Heat and Second Sound Measurements with the DYNAMIX Instrument

    Science.gov (United States)

    Nissen, Joel

    2003-01-01

    In addition to its primary role of studying non-linear heat transport effects near the lambda transition of He-4, the DYNAMX apparatus is suitable for measurements of the specific heat and the velocity of second sound. We plan to take advantage of available time on orbit to make measurements in these areas near to the lambda transition. The specific heat work would be similar to LPE, aimed at improving our knowledge of the singularity in the bulk heat capacity at the transition, but would provide more accurate results close to the transition. It would focus roughly equally on each side of the transition and would be synergistic with the CQ experiment, providing wider-range data at Q = 0. The second sound measurements are made possible by the fast time constant and high resolution of the DYNAMX thermometers, which allow accurate time-of-flight measurements of second sound pulses. It appears possible to measure the second sound velocity to about 1% at a reduced temperature of t = 5x10(exp -8) by averaging over a moderate number of pulses. The data would complement and extend earlier ground-based measurements, leading to improved tests of the theory of static critical phenomena at the lambda transition.

  5. Infrared thermography for convective heat transfer measurements

    Energy Technology Data Exchange (ETDEWEB)

    Carlomagno, Giovanni Maria; Cardone, Gennaro [University of Naples Federico II, Department of Aerospace Engineering, Naples (Italy)

    2010-12-15

    This paper deals with the evolution of infrared (IR) thermography into a powerful optical tool that can be used in complex fluid flows to either evaluate wall convective heat fluxes or investigate the surface flow field behavior. Measurement of convective heat fluxes must be performed by means of a thermal sensor, where temperatures have to be measured with proper transducers. By correctly choosing the thermal sensor, IR thermography can be successfully exploited to resolve convective heat flux distributions with both steady and transient techniques. When comparing it to standard transducers, the IR camera appears very valuable because it is non-intrusive, it has a high sensitivity (down to 20 mK), it has a low response time (down to 20 {mu}s), it is fully two dimensional (from 80 k up to 1 M pixels, at 50 Hz) and, therefore, it allows for better evaluation of errors due to tangential conduction within the sensor. This paper analyses the capability of IR thermography to perform convective heat transfer measurements and surface visualizations in complex fluid flows. In particular, it includes the following: the necessary radiation theory background, a review of the main IR camera features, a description of the pertinent heat flux sensors, an analysis of the IR image processing methods and a report on some applications to complex fluid flows, ranging from natural convection to hypersonic regime. (orig.)

  6. Emulsion stabilizing capacity of intact starch granules modified by heat treatment or octenyl succinic anhydride.

    Science.gov (United States)

    Timgren, Anna; Rayner, Marilyn; Dejmek, Petr; Marku, Diana; Sjöö, Malin

    2013-03-01

    Starch granules are an interesting stabilizer candidate for food-grade Pickering emulsions. The stabilizing capacity of seven different intact starch granules for making oil-in-water emulsions has been the topic of this screening study. The starches were from quinoa; rice; maize; waxy varieties of rice, maize, and barley; and high-amylose maize. The starches were studied in their native state, heat treated, and modified by octenyl succinic anhydride (OSA). The effect of varying the continuous phase, both with and without salt in a phosphate buffer, was also studied. Quinoa, which had the smallest granule size, had the best capacity to stabilize oil drops, especially when the granules had been hydrophobically modified by heat treatment or by OSA. The average drop diameter (d 32) in these emulsions varied from 270 to 50 μm, where decreasing drop size and less aggregation was promoted by high starch concentration and absence of salt in the system. Of all the starch varieties studied, quinoa had the best overall emulsifying capacity, and OSA modified quinoa starch in particular. Although the size of the drops was relatively large, the drops themselves were in many instances extremely stable. In the cases where the system could stabilize droplets, even when they were so large that they were visible to the naked eye, they remained stable and the measured droplet sizes after 2 years of storage were essentially unchanged from the initial droplet size. This somewhat surprising result has been attributed to the thickness of the adsorbed starch layer providing steric stabilization. The starch particle-stabilized Pickering emulsion systems studied in this work has potential practical application such as being suitable for encapsulation of ingredients in food and pharmaceutical products.

  7. Heat capacity and monogamy relations in the mixed-three-spin XXX Heisenberg model at low temperatures

    Science.gov (United States)

    Zad, Hamid Arian; Movahhedian, Hossein

    2016-08-01

    Heat capacity of a mixed-three-spin (1/2,1,1/2) antiferromagnetic XXX Heisenberg chain is precisely investigated by use of the partition function of the system for which, spins (1,1/2) have coupling constant J1 and spins (1/2,1/2) have coupling constant J2. We verify tripartite entanglement for the model by means of the convex roof extended negativity (CREN) and concurrence as functions of temperature T, homogeneous magnetic field B and the coupling constants J1 and J2. As shown in our previous work, [H. A. Zad, Chin. Phys. B 25 (2016) 030303.] the temperature, the magnetic field and the coupling constants dependences of the heat capacity for such spin system have different behaviors for the entangled and separable states, hence, we did some useful comparisons between this quantity and negativities of its organized bipartite (sub)systems at entangled and separable states. Here, we compare the heat capacity of the mixed-three-spin (1/2,1,1/2) system with the CREN and the tripartite concurrence (as measures of the tripartite entanglement) at low temperature. Ground state phase transitions, and also, transition from ground state to some excited states are explained in detail for this system at zero temperature. Finally, we investigate the heat capacity behavior around those critical points in which these quantum phase transitions occur.

  8. Influence of collector heat capacity and internal conditions of heat exchanger on cool-down process of small gas liquefier

    Science.gov (United States)

    Saberimoghaddam, Ali; Bahri Rasht Abadi, Mohammad Mahdi

    2018-01-01

    Joule-Thomson cooling systems are commonly used in gas liquefaction. In small gas liquefiers, transient cool-down time is high. Selecting suitable conditions for cooling down process leads to decrease in time and cost. In the present work, transient thermal behavior of Joule-Thomson cooling system including counter current helically coiled tube in tube heat exchanger, expansion valve, and collector was studied using experimental tests and simulations. The experiments were performed using small gas liquefier and nitrogen gas as working fluid. The heat exchanger was thermally studied by experimental data obtained from a small gas liquefier. In addition, the simulations were performed using experimental data as variable boundary conditions. A comparison was done between presented and conventional methods. The effect of collector heat capacity and convection heat transfer coefficient inside the tubes on system performance was studied using temperature profiles along the heat exchanger.

  9. Reductive capacity measurement of waste forms for secondary radioactive wastes

    Energy Technology Data Exchange (ETDEWEB)

    Um, Wooyong; Yang, Jung-Seok; Serne, R. Jeffrey; Westsik, Joseph H.

    2015-12-01

    The reductive capacities of dry ingredients and final solid waste forms were measured using both the Cr(VI) and Ce(IV) methods and the results were compared. Blast furnace slag (BFS), sodium sulfide, SnF2, and SnCl2 used as dry ingredients to make various waste forms showed significantly higher reductive capacities compared to other ingredients regardless of which method was used. Although the BFS exhibits appreciable reductive capacity, it requires greater amounts of time to fully react. In almost all cases, the Ce(IV) method yielded larger reductive capacity values than those from the Cr(VI) method and can be used as an upper bound for the reductive capacity of the dry ingredients and waste forms, because the Ce(IV) method subjects the solids to a strong acid (low pH) condition that dissolves much more of the solids. Because the Cr(VI) method relies on a neutral pH condition, the Cr(VI) method can be used to estimate primarily the waste form surface-related and readily dissolvable reductive capacity. However, the Cr(VI) method does not measure the total reductive capacity of the waste form, the long-term reductive capacity afforded by very slowly dissolving solids, or the reductive capacity present in the interior pores and internal locations of the solids.

  10. Linear heating system for measurement of thermoluminescence ...

    Indian Academy of Sciences (India)

    Unknown

    scence intensity is monitored. The theory of TL usually assumes that the sample temperature varies linearly with time, although more general theories have been formu- lated and calculations made for non-linear heating system. Previous descriptions of apparatus for the measurement of TL have been published elsewhere ...

  11. Cooling and Heating Season Impacts of Right-Sizing of Fixed- and Variable-Capacity Heat Pumps With Attic and Indoor Ductwork

    Energy Technology Data Exchange (ETDEWEB)

    Cummings, James [Building America Partnership for Improved Residential Construction, Cocoa, FL (United States); Withers, Charles [Building America Partnership for Improved Residential Construction, Cocoa, FL (United States); Kono, Jamie [Building America Partnership for Improved Residential Construction, Cocoa, FL (United States)

    2015-06-01

    A new generation of central, ducted variable-capacity heat pump systems has come on the market, promising very high cooling and heating efficiency. They are controlled differently than standard fixed-capacity systems. Instead of cycling on at full capacity and then cycling off when the thermostat is satisfied, they vary their cooling and heating output over a wide range (approximately 40% - 118% of nominal full capacity), thus staying 'on' for 60% - 100% more hours per day compared to fixed -capacity systems. Experiments in this research examined the performance of 2-ton and 3-ton fixed- and variable-capacity systems and the impacts of system oversizing.

  12. FEM Simulation of the Effect of Coefficient of Thermal Expansion and Heat Capacity on Prediction of Residual Stresses of Compression Molded Glass Lenses

    Science.gov (United States)

    Tao, Bo; Yuan, Ye

    2017-11-01

    In this research, the effects of the coefficient of thermal expansion (CTE) and heat capacity on the prediction of residual stresses in BK7 compression molded glass lenses were studied. Three different groups of CTE and two different kinds of heat capacity, which are constant and proportional to temperature, were chosen to investigate the impacts of residual stresses. The simulation results show a big difference and suggest that the properties of glass materials determine the residual stresses and should be measured carefully.

  13. Measured Performance of a Low Temperature Air Source Heat Pump

    Energy Technology Data Exchange (ETDEWEB)

    R.K. Johnson

    2013-09-01

    A 4-ton Low Temperature Heat Pump (LTHP) manufactured by Hallowell International was installed in a residence near New Haven, Connecticut and monitored over two winters of operation. After attending to some significant service issues, the heat pump operated as designed. This report should be considered a review of the dual compressor “boosted heat pump” technology. The Low Temperature Heat Pump system operates with four increasing levels of capacity (heat output) as the outdoor temperature drops.

  14. Technical-and-Economic Efficiency of Draft Enriched with Oxygen in Small-Capacity Heating Boilers

    Directory of Open Access Journals (Sweden)

    P. Ratnikov

    2013-01-01

    Full Text Available Data on complex experimental and theoretical investigations pertaining to efficiency of oxygen-enriched draft in the small-capacity heating boilers as exemplified by the plant HEIZA (HW-S-10/K have been presented in the paper. The paper provides a calculation model of heating processes in heat generator burner (as exemplified by HEIZA plant. Simulation of heating processes in the operational zone has been executed in paper. The experimental data have proved model adequacy. The calculation scheme of the plant will be used in future for determination of power and ecological efficiency of draft enrichment with oxygen.

  15. Analysis of heat capacity and Mössbauer data for LuZnSn2 compound

    Directory of Open Access Journals (Sweden)

    Łątka Kazimierz

    2015-03-01

    Full Text Available New analysis of heat capacity data is presented for LuZnSn2 compound that takes into account anharmonic effects together with the existence of Einstein modes. 119mSn Mössbauer spectroscopy was used to monitor the hyperfine parameters at the two crystallographically inequivalent Sn sites in the studied compound. The problem of non-unique mathematical resonance spectrum description and the problem how to choose physically meaningful set of hyperfine parameters will be thoroughly discussed. Measured quadrupole interaction constants by 119mSn Mössbauer spectroscopy give estimations for Vzz component of electric field gradient tensor at both Sn sites in LuZnSn2.

  16. A Framework for Spatial Assessment of Local Level Vulnerability and Adaptive Capacity to Extreme Heat

    Science.gov (United States)

    Wilhelmi, O.; Hayden, M.; Harlan, S.; Ruddell, D.; Komatsu, K.; England, B.; Uejio, C.

    2008-12-01

    Changing climate is predicted to increase the intensity and impacts of heat waves prompting the need to develop preparedness and adaptation strategies that reduce societal vulnerability. Central to understanding societal vulnerability, is adaptive capacity, the potential of a system or population to modify its features/behaviors so as to better cope with existing and anticipated stresses and fluctuations. Adaptive capacity influences adaptation, the actual adjustments made to cope with the impacts from current and future hazardous heat events. Understanding societal risks, vulnerabilities and adaptive capacity to extreme heat events and climate change requires an interdisciplinary approach that includes information about weather and climate, the natural and built environment, social processes and characteristics, interactions with the stakeholders, and an assessment of community vulnerability. This project presents a framework for an interdisciplinary approach and a case study that explore linkages between quantitative and qualitative data for a more comprehensive understanding of local level vulnerability and adaptive capacity to extreme heat events in Phoenix, Arizona. In this talk, we will present a methodological framework for conducting collaborative research on societal vulnerability and adaptive capacity on a local level that includes integration of household surveys into a quantitative spatial assessment of societal vulnerability. We highlight a collaborative partnership among researchers, community leaders and public health officials. Linkages between assessment of local adaptive capacity and development of regional climate change adaptation strategies will be discussed.

  17. Cryogenic Heat Load and Refrigeration Capacity Management at the Large Hadron Collider (LHC)

    CERN Document Server

    Claudet, S; Serio, L; Tavian, L; Van Weelderen, R; Wagner, U

    2009-01-01

    The Large Hadron Collider (LHC) is a 26.7 km high-energy proton and ion collider based on several thousand high-field superconducting magnets operating in superfluid helium below 2 K, now under commissioning at CERN. After a decade of development of the key technologies, the project was approved for construction in 1994 and the industrial procurement for the cryogenic system launched in 1997, concurrently with the completion of the R&D program. This imposed to base the sizing of the refrigeration plants on estimated and partially measured values of static and dynamic heat loads, with adequate uncertainty and overcapacity coefficients to cope with unknowns in machine configuration and in physical processes at work. With the cryogenic commissioning of the complete machine, full-scale static heat loads could be measured, thus confirming the correctness of the estimates and the validity of the approach, and safeguarding excess refrigeration capacity for absorbing the beam-induced dynamic loads. The metho...

  18. Measurement of heat and moisture exchanger efficiency.

    Science.gov (United States)

    Chandler, M

    2013-09-01

    Deciding between a passive heat and moisture exchanger or active humidification depends upon the level of humidification that either will deliver. Published international standards dictate that active humidifiers should deliver a minimum humidity of 33 mg.l(-1); however, no such requirement exists, for heat and moisture exchangers. Anaesthetists instead have to rely on information provided by manufacturers, which may not allow comparison of different devices and their clinical effectiveness. I suggest that measurement of humidification efficiency, being the percentage moisture returned and determined by measuring the temperature of the respired gases, should be mandated, and report a modification of the standard method that will allow this to be easily measured. In this study, different types of heat and moisture exchangers for adults, children and patients with a tracheostomy were tested. Adult and paediatric models lost between 6.5 mg.l(-1) and 8.5 mg.l(-1) moisture (corresponding to an efficiency of around 80%); however, the models designed for patients with a tracheostomy lost between 16 mg.l(-1) and 18 mg.l(-1) (60% efficiency). I propose that all heat and moisture exchangers should be tested in this manner and percentage efficiency reported to allow an informed choice between different types and models. © 2013 The Association of Anaesthetists of Great Britain and Ireland.

  19. Multiple pulse-heating experiments with different current to determine total emissivity, heat capacity, and electrical resistivity of electrically conductive materials at high temperatures

    Science.gov (United States)

    Watanabe, Hiromichi; Yamashita, Yuichiro

    2012-01-01

    A modified pulse-heating method is proposed to improve the accuracy of measurement of the hemispherical total emissivity, specific heat capacity, and electrical resistivity of electrically conductive materials at high temperatures. The proposed method is based on the analysis of a series of rapid resistive self-heating experiments on a sample heated at different temperature rates. The method is used to measure the three properties of the IG-110 grade of isotropic graphite at temperatures from 850 to 1800 K. The problem of the extrinsic heating-rate effect, which reduces the accuracy of the measurements, is successfully mitigated by compensating for the generally neglected experimental error associated with the electrical measurands (current and voltage). The results obtained by the proposed method can be validated by the linearity of measured quantities used in the property determinations. The results are in reasonably good agreement with previously published data, which demonstrate the suitability of the proposed method, in particular, to the resistivity and total emissivity measurements. An interesting result is the existence of a minimum in the emissivity of the isotropic graphite at around 1120 K, consistent with the electrical resistivity results.

  20. Calculation of thermal conductivity, thermal diffusivity and specific heat capacity of sedimentary rocks using petrophysical well logs

    DEFF Research Database (Denmark)

    Fuchs, Sven; Balling, Niels; Förster, Andrea

    2015-01-01

    In this study, equations are developed that predict for synthetic sedimentary rocks (clastics, carbonates and evapourates) thermal properties comprising thermal conductivity, specific heat capacity and thermal diffusivity. The rock groups are composed of mineral assemblages with variable contents...... of each property vary depending on the selected well-log combination. Best prediction is in the range of 2–8 per cent for the specific heat capacity, of 5–10 per cent for the thermal conductivity, and of 8–15 for the thermal diffusivity, respectively. Well-log derived thermal conductivity is validated...... by laboratory data measured on cores from deep boreholes of the Danish Basin, the North German Basin, and the Molasse Basin. Additional validation of thermal conductivity was performed by comparing predicted and measured temperature logs. The maximum deviation between these logs is conductivity...

  1. Heat capacities and asymmetric criticality of coexistence curves for benzonitrile + alkanes and dimethyl carbonate + alkanes.

    Science.gov (United States)

    Huang, Meijun; Lei, Yuntao; Yin, Tianxiang; Chen, Zhiyun; An, Xueqin; Shen, Weiguo

    2011-11-24

    The critical behavior of isobaric heat capacities per unit volume for a series of critical binary solutions {benzonitrile + octane, or dodecane, or hexadecane} and {dimethyl carbonate + nonane, or decane, or dodecane} were studied. The corresponding exponent was obtained to be in consistent with the 3D-Ising value. The amplitudes in one-phase and two-phase regions were deduced, which were used to test some critical amplitude ratios. Analysis of the dependence of the effective critical exponent of the heat capacity on the temperature indicated a critical crossover from the 3D-Ising to the mean-field for all the studied systems. It was found that the heat capacity does play an important role for describing the asymmetric criticality of coexistence curves by the complete scaling theory. © 2011 American Chemical Society

  2. The Magnetocaloric Effect and Heat Capacity of Suspensions of High-Dispersity Samarium Ferrite

    Science.gov (United States)

    Korolev, V. V.; Aref'ev, I. M.; Ramazanova, A. G.

    2008-02-01

    The magnetocaloric effect and specific heat capacity of an aqueous suspension of samarium ferrite were determined calorimetrically over the temperature range 288-343 K in magnetic fields of 0-0.7 T. The data obtained were used to calculate changes in the magnetic component of the molar heat capacity and entropy of the magnetic phase and changes in the enthalpy of the process under an applied magnetic field. The magnetocaloric effect was found to increase nonlinearly as the magnetic field induction grew. The corresponding temperature dependences contained a maximum at 313 K related to the second-order magnetic phase transition at the Curie point. The field and temperature dependences of heat capacity contained a maximum in fields of 0.4 T and a minimum at the magnetic phase transition temperature.

  3. Circular Dichroism Method for Heat Capacity Determination of Proteins

    Science.gov (United States)

    Jones, Cecil L.; Bailey, Chris; Bheemarti, Kiran Kumar

    2006-01-01

    Circular dichroism spectroscopy was used to measure the thermal unfolding of bovine pancreatic ribonuclease A (RNase A) with various concentrations of guanidine hydrochloride (GuHCl). A red shift in transition midpoint temperatures, T[subscript m], occurred with increasing concentration of the strong protein denaturant. van Hoff enthalpy changes,…

  4. Age-related differences in heat loss capacity occur under both dry and humid heat stress conditions.

    Science.gov (United States)

    Larose, Joanie; Boulay, Pierre; Wright-Beatty, Heather E; Sigal, Ronald J; Hardcastle, Stephen; Kenny, Glen P

    2014-07-01

    This study examined the progression of impairments in heat dissipation as a function of age and environmental conditions. Sixty men (n = 12 per group; 20-30, 40-44, 45-49, 50-54, and 55-70 yr) performed four intermittent exercise/recovery cycles for a duration of 2 h in dry (35°C, 20% relative humidity) and humid (35°C, 60% relative humidity) conditions. Evaporative heat loss and metabolic heat production were measured by direct and indirect calorimetry, respectively. Body heat storage was measured as the temporal summation of heat production and heat loss during the sessions. Evaporative heat loss was reduced during exercise in the humid vs. dry condition in age groups 20-30 (-17%), 40-44 (-18%), 45-49 (-21%), 50-54 (-25%), and 55-70 yr (-20%). HE fell short of being significantly different between groups in the dry condition, but was greater in age group 20-30 yr (279 ± 10 W) compared with age groups 45-49 (248 ± 8 W), 50-54 (242 ± 6 W), and 55-70 yr (240 ± 7 W) in the humid condition. As a result of a reduced rate of heat dissipation predominantly during exercise, age groups 40-70 yr stored between 60-85 and 13-38% more heat than age group 20-30 yr in the dry and humid conditions, respectively. These age-related differences in heat dissipation and heat storage were not paralleled by significant differences in local sweating and skin blood flow, or by differences in core temperature between groups. From a whole body perspective, combined heat and humidity impeded heat dissipation to a similar extent across age groups, but, more importantly, intermittent exercise in dry and humid heat stress conditions created a greater thermoregulatory challenge for middle-aged and older adults. Copyright © 2014 the American Physiological Society.

  5. THERMAL STUDY OF THE DIII-D MACHINE HEAT REMOVAL CAPACITY

    Energy Technology Data Exchange (ETDEWEB)

    YIP,H; ADERSON,P.M; HOLTROP,K.L; HARRISON,S

    2003-10-01

    OAK-B135 With each plasma shot, the DIII-D tokamak dissipates 0.5 to 1.0 GJ of energy. Plasma shots may occur as frequently as every ten minutes, and the energy is removed in the form of heat by a cooling water system. to remove heat from the machine, cooling water circulates through each major heat source. These sources include the power supplies, motor/generator, rf current drives, neutral beam power supplies, magnetic field coils, and vacuum vessel. The cooling water system consists of isolated primary and secondary cooling loops separated by intermediate heat exchangers. As future DIII-D plans include operation during summer months and longer pulse duration, the cooling system's overall heat removal capability and performance efficiency must be assessed. Temperature and flow data from around the DIII-D facility are collected by a programmable logic controller (PLC); the data are used to analyze the heat generating sources, the heat transfer rate to intermediate heat exchangers, and the ultimate heat rejection to the environment via the cooling towers. A comparison of the original DIII-D machine design versus the actual performance determines the margin of heat removal capacity. projections of the heat removal rate for various longer plasma shots are made. Improvements in design and/or operational procedure will be necessary to attain the desired pulse duration.

  6. Investigations of temperature dependences of electrical resistivity and specific heat capacity of metals

    Energy Technology Data Exchange (ETDEWEB)

    Eser, Erhan, E-mail: eserphy@gmail.com [Department of Physics, Polatlı Faculty of Arts and Sciences, Gazi University, Polatlı, Ankara (Turkey); Koç, Hüseyin [Department of Electrical and Electronics Engineering, Faculty of Engineering, Muş Alparslan University, Muş (Turkey)

    2016-07-01

    In this study, we calculated the electrical resistivity and heat capacities of some ideal metals (Cu, Pt, and Pd) using a method that it employs the statistical model and Debye functions. The method is used to provide a simple and reliable analytical procedure for wide temperature range. The results obtained for the electrical resistivity and heat capacity have been compared with the results in literature. The results obtained at low temperature are in excellent agreement with experimental and theoretical results. Finally the used approximation and analytical method are a useful approach to calculate thermophysical properties of metals.

  7. Empirical equations for viscosity and specific heat capacity determination of paraffin PCM and fatty acid PCM

    Science.gov (United States)

    Barreneche, C.; Ferrer, G.; Palacios, A.; Solé, A.; Inés Fernández, A.; Cabeza, L. F.

    2017-10-01

    Phase change materials (PCM) used in thermal energy storage (TES) systems have been presented, over recent years, as one of the most effective options in energy storage. Paraffin and fatty acids are some of the most used PCM in TES systems, as they have high phase change enthalpy and in addition they do not present subcooling nor hysteresis and have proper cycling stability. The simulations and design of TES systems require the knowledge of the thermophysical properties of PCM. Thermal conductivity, viscosity, specific heat capacity (Cp) can be experimentally determined, but these are material and time consuming tasks. To avoid or to reduce them, and to have reliable data without the need of experimentation, thermal properties can be calculated by empirical equations. In this study, five different equations are given to calculate the viscosity and specific heat capacity of fatty acid PCM and paraffin PCM. Two of these equations concern, respectively, the empirical calculation of the viscosity and liquid Cp of the whole paraffin PCM family, while the other three equations presented are for the corresponding calculation of viscosity, solid Cp, liquid Cp of the whole fatty acid family of PCM. Therefore, this study summarize the work performed to obtain the main empirical equations to measure the above mentioned properties for whole fatty acid PCM family and whole paraffin PCM family. Moreover, empirical equations have been obtained to calculate these properties for other materials of these PCM groups and these empirical equations can be extrapolated for PCM with higher or lower phase change temperatures within a lower relative error 4%.

  8. Influence of heat treatment on antioxidant capacity and (poly)phenolic compounds of selected vegetables

    OpenAIRE

    Juaniz, I. (Isabel); Ludwig, I.A. (Iziar A.); Huarte, E; Pereira-Caro, G.; Moreno-Rojas, J.M.; Cid, C. (Concepción); Peña, M.P. (María Paz) de

    2016-01-01

    The impact of cooking heat treatments (frying in olive oil, frying in sunflower oil and griddled) on the antioxidant capacity and (poly)phenolic compounds of onion, green pepper and cardoon, was evaluated. The main compounds were quercetin and isorhamnetin derivates in onion, quercetin and luteolin derivates in green pepper samples, and chlorogenic acids in cardoon. All heat treatments tended to increase the concentration of phenolic compounds in vegetables suggesting a thermal destruction of...

  9. Measuring weld heat to evaluate weld integrity

    Energy Technology Data Exchange (ETDEWEB)

    Schauder, V., E-mail: schauder@hks-prozesstechnik.de [HKS-Prozesstechnik GmbH, Halle (Germany)

    2015-11-15

    Eddy current and ultrasonic testing are suitable for tube and pipe mills and have been used for weld seam flaw detection for decades, but a new process, thermography, is an alternative. By measuring the heat signature of the weld seam as it cools, it provides information about weld integrity at and below the surface. The thermal processes used to join metals, such as plasma, induction, laser, and gas tungsten arc welding (GTAW), have improved since they were developed, and they get better with each passing year. However, no industrial process is perfect, so companies that conduct research in flaw detection likewise continue to develop and improve the technologies used to verify weld integrity: ultrasonic testing (UT), eddy current testing (ET), hydrostatic, X-ray, magnetic particle, and liquid penetrant are among the most common. Two of these are used for verifying the integrity of the continuous welds such as those used on pipe and tube mills: UT and ET. Each uses a transmitter to send waves of ultrasonic energy or electrical current through the material and a receiver (probe) to detect disturbances in the flow. The two processes often are combined to capitalize on the strengths of each. While ET is good at detecting flaws at or near the surface, UT penetrates the material, detecting subsurface flaws. One drawback is that sound waves and electrical current waves have a specific direction of travel, or an alignment. A linear defect that runs parallel to the direction of travel of the ultrasonic sound wave or a flaw that is parallel to the coil winding direction of the ET probe can go undetected. A second drawback is that they don't detect cold welds. An alternative process, thermography, works in a different fashion: It monitors the heat of the material as the weld cools. Although it measures the heat at the surface, the heat signature provides clues about cooling activity deep in the material, resulting in a thorough assessment of the weld's integrity It

  10. Measurement of the Specific Heat Using a Gravity Cancellation Approach

    Science.gov (United States)

    Zhong, Fang

    2003-01-01

    The specific heat at constant volume C(sob V) of a simple fluid diverges near its liquid-vapor critical point. However, gravity-induced density stratification due to the divergence of isothermal susceptibility hinders the direct comparison of the experimental data with the predictions of renormalization group theory. In the past, a microgravity environment has been considered essential to eliminate the density stratification. We propose to perform specific heat measurements of He-3 on the ground using a method to cancel the density stratification. A He-3 fluid layer will be heated from below, using the thermal expansion of the fluid to cancel the hydrostatic compression. A 6% density stratification at a reduced temperature of 10(exp -5) can be cancelled to better than 0.1% with a steady 1.7 micro K temperature difference across a 0.05 cm thick fluid layer. A conventional AC calorimetry technique will be used to determine the heat capacity. The minimized bulk density stratification with a relaxation time 6500 sec at a reduced temperature of 10(exp -5) will stay unchanged during 1 Hz AC heating. The smear of the specific heat divergence due to the temperature difference across the cell is about 0.1% at a reduced temperature of 10(exp -6). The combination of using High Resolution Thermometry with a 0.5 n K temperature resolution in the AC technique and the cancellation of the density stratification will enable C(sub V) to be measured down to a reduced temperature of 10(exp -6) with less than a 1% systematic error.

  11. New techniques for measuring thermal properties and surface heat transfer applied to food freezing

    OpenAIRE

    Brennvall, Jon Eirik

    2007-01-01

    This thesis presents two different works. The first part introduces a thermal multimeter which measures heat capacity, thermal conductivity and density. The instrument gives continuous measurement data within a temperature range. With some exceptions this also holds for the prototype of a thermal multimeter which is built and tested. The measuring method is constant heating of one side of a slab. The slab is insulated on all other sides. After some time there will be equilibrium where there i...

  12. Parametric Study on the Dynamic Heat Storage Capacity of Building Elements

    DEFF Research Database (Denmark)

    Artmann, Nikolai; Manz, H.; Heiselberg, Per

    2007-01-01

    of onedimensional heat conduction in a slab with convective boundary condition was applied to quantify the dynamic heat storage capacity of a particular building element. The impact of different parameters, such as slab thickness, material properties and the heat transfer coefficient was investigated, as well......In modern, extensively glazed office buildings, due to high solar and internal loads and increased comfort expectations, air conditioning systems are often used even in moderate and cold climates. Particularly in this case, passive cooling by night-time ventilation seems to offer considerable...... potential. However, because heat gains and night ventilation periods do not coincide in time, a sufficient amount of thermal mass is needed in the building to store the heat. Assuming a 24 h-period harmonic oscillation of the indoor air temperature within a range of thermal comfort, the analytical solution...

  13. Building America Case Study: Impact of Improved Duct Insulation on Fixed-Capacity (SEER 13) and Variable-Capacity (SEER 22) Heat Pumps, Cocoa, Florida

    Energy Technology Data Exchange (ETDEWEB)

    C. Withers, J. Cummings, B. Nigusse, E. Martin

    2017-04-01

    A new generation of central, ducted variable-capacity heat pump systems has come on the market, promising very high cooling and heating efficiency. Instead of cycling on at full capacity and then cycling off when the thermostat is satisfied, they vary their cooling and heating output over a wide range (approximately 40 to 118% of nominal full capacity); thus, staying 'on' for 60% to 100% more hours per day compared to fixed-capacity systems. Current Phase 4 experiments in an instrumented lab home with simulated occupancy evaluate the impact of duct R-value enhancement on the overall operating efficiency of the variable-capacity system compared to the fixed-capacity system.

  14. Low-temperature heat capacities and Raman spectra of negative thermal expansion compounds ZrW2O8 and HfW2O8

    Science.gov (United States)

    Yamamura, Yasuhisa; Nakajima, Noriyuki; Tsuji, Toshihide; Koyano, Mikio; Iwasa, Yoshihiro; Katayama, Shin'ichi; Saito, Kazuya; Sorai, Michio

    2002-06-01

    Heat capacities of ZrW2O8 and HfW2O8 were precisely measured between 1.8 and 330 K. Heat-capacity curves of ZrW2O8 and HfW2O8 are very similar to each other. The heat capacity of HfW2O8 at low temperature is larger than that of ZrW2O8 due to atomic mass effect, but both heat capacities cross around 220 K. Raman spectra of ZrW2O8 and HfW2O8 were recorded at room temperature. Frequency distributions of lattice vibrations were estimated through an analysis of the heat capacities for ZrW2O8 and HfW2O8. It is found that the difference in the frequency distributions between ZrW2O8 and HfW2O8 arises from the different atomic mass and bond strength, and causes the different temperature dependence of the heat capacities. The properties of the optical-phonon modes with a large negative mode-Grüneisen parameter are discussed.

  15. Effect of high energy electron beam (10MeV) on specific heat capacity of low-density polyethylene/hydroxyapatite nano-composite.

    Science.gov (United States)

    Soltani, Z; Ziaie, F; Ghaffari, M; Beigzadeh, A M

    2017-02-01

    In the present work, thermal properties of low density polyethylene (LDPE) and its nano composites are investigated. For this purpose LDPE reinforced with different weight percents of hydroxyapatite (HAP) powder which was synthesized via hydrolysis method are produced. The samples were irradiated with 10MeV electron beam at doses of 75 to 250kGy. Specific heat capacity measurement have been carried out at different temperatures, i.e. 25, 50, 75 and 100°C using modulated temperature differential scanning calorimetry (MTDSC) apparatus and the effect of three parameters include of temperature, irradiation dose and the amount of HAP nano particles as additives on the specific heat capacity of PE/HAP have been investigated precisely. The MTDSC results indicate that the specific heat capacity have decreased by addition of nano sized HAP as reinforcement for LDPE. On the other hand, the effect of radiation dose is reduction in the specific heat capacity in all materials including LDPE and its nano composites. The HAP nano particles along with cross-link junctions due to radiation restrain the movement of the polymer chains in the vicinity of each particle and improve the immobility of polymer chains and consequently lead to reduction in specific heat capacity. Also, the obtained results confirm that the radiation effect on the specific heat capacity is more efficient than the reinforcing effect of nano-sized hydroxyapatite. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Size-dependence of the heat capacity and thermodynamic properties of hematite ({alpha}-Fe{sub 2}O{sub 3})

    Energy Technology Data Exchange (ETDEWEB)

    Snow, Claine L.; Lee, Christopher R.; Shi, Quan; Boerio-Goates, Juliana [Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT 84602 (United States); Woodfield, Brian F., E-mail: brian_woodfield@byu.ed [Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT 84602 (United States)

    2010-09-15

    The heat capacity of a 13 nm hematite ({alpha}-Fe{sub 2}O{sub 3}) sample was measured from T = (1.5 to 350) K using a combination of semi-adiabatic and adiabatic calorimetry. The heat capacity was higher than that of the bulk which can be attributed to the presence of water on the surface of the nanoparticles. No anomaly was observed in the heat capacity due to the Morin transition and theoretical fits of the heat capacity below T = 15 K show a small T{sup 3} dependence (due to lattice contributions) with no T{sup 3/2} dependence. This suggests that there are no magnetic spin-wave contributions to the heat capacity of 13 nm hematite. The use of a large linear term to fit the heat capacity below T = 15 K is most likely due to superparamagnetic contributions. A small anomaly within the temperature range (4 to 8) K was attributed to the presence of uncompensated surface spins.

  17. Glass heat capacity and its abrupt change in glass transition region

    DEFF Research Database (Denmark)

    Yue, Yuanzheng; Smedskjær, Morten Mattrup; Mauro, John C.

    Glass transition (GT) has been a fascinating, but challenging subject in the condensed matter science over decades. Despite progress in understanding GT, many crucial problems still need to be clarified. One of the problems deals with the microscopic origin of abrupt change of heat capacity (Cp) ...

  18. Comparative analysis of single- and continuously variable-capacity heat pump concepts

    Energy Technology Data Exchange (ETDEWEB)

    Rice, C.K.; Fischer, S.K.

    1984-01-01

    This work is an initial assessment of the potential benefits of continuous-capacity-modulation in electric-driven, air-to-air heat pumps for residential application. The purpose of the project was to provide a quantitative estimate of the possible annual performance gains of advanced continuously modulating heat pumps relative to single-speed designs at comparable levels of development. Previous analytical design work in this area at ORNL dealt with single-design-point, heating-mode optimization of single-speed heat pumps. For that work the ORNL Steady State Heat Pump Design Model was connected to a constrained numerical optimization code. The present work represents an extension of the earlier work in two directions. First, seasonal (heating and cooling) and annual performance factor (APF) analysis capability was added to allow direct evaluation of annual energy use from heat pump performance data generated by the ORNL heat pump model. Secondly, a modulating version of the heat pump model was developed to provide a means for simulating the steady state performance of continuously variable-speed (CVS) systems. With these tools, the APFs of both single- and continuously variable-capacity (CVC) concepts could be studied as basic heat pump design variables were varied. Based on this initial evaluation of CVS systems and considering the potential for electronics costs to further decrease as electricity prices rise, we see such advanced CVS systems as a strong future competitor to single-speed systems and as decidedly superior in energy conservation potential. To achieve this position, it seems especially important that such systems be computer optimized to take full advantage of the increased design flexibility available. Further, development of PM-ECMs or equivalent technology must continue to the point of providing speed controllers of: moderate to low cost, moderate to high performance, and high reliability. 16 refs., 12 figs.

  19. Enhancing heat capacity of colloidal suspension using nanoscale encapsulated phase-change materials for heat transfer.

    Science.gov (United States)

    Hong, Yan; Ding, Shujiang; Wu, Wei; Hu, Jianjun; Voevodin, Andrey A; Gschwender, Lois; Snyder, Ed; Chow, Louis; Su, Ming

    2010-06-01

    This paper describes a new method to enhance the heat-transfer property of a single-phase liquid by adding encapsulated phase-change nanoparticles (nano-PCMs), which absorb thermal energy during solid-liquid phase changes. Silica-encapsulated indium nanoparticles and polymer-encapsulated paraffin (wax) nanoparticles have been made using colloid method, and suspended into poly-alpha-olefin (PAO) and water for potential high- and low-temperature applications, respectively. The shells prevent leakage and agglomeration of molten phase-change materials, and enhance the dielectric properties of indium nanoparticles. The heat-transfer coefficients of PAO containing indium nanoparticles (30% by mass) and water containing paraffin nanoparticles (10% by mass) are 1.6 and 1.75 times higher than those of corresponding single-phase fluids. The structural integrity of encapsulation allows repeated use of such nanoparticles for many cycles in high heat generating devices.

  20. Novel Anthropometry-Based Calculation of the Body Heat Capacity in the Korean Population.

    Directory of Open Access Journals (Sweden)

    Duong Duc Pham

    Full Text Available Heat capacity (HC has an important role in the temperature regulation process, particularly in dealing with the heat load. The actual measurement of the body HC is complicated and is generally estimated by body-composition-specific data. This study compared the previously known HC estimating equations and sought how to define HC using simple anthropometric indices such as weight and body surface area (BSA in the Korean population. Six hundred participants were randomly selected from a pool of 902 healthy volunteers aged 20 to 70 years for the training set. The remaining 302 participants were used for the test set. Body composition analysis using multi-frequency bioelectrical impedance analysis was used to access body components including body fat, water, protein, and mineral mass. Four different HCs were calculated and compared using a weight-based HC (HC_Eq1, two HCs estimated from fat and fat-free mass (HC_Eq2 and HC_Eq3, and an HC calculated from fat, protein, water, and mineral mass (HC_Eq4. HC_Eq1 generally produced a larger HC than the other HC equations and had a poorer correlation with the other HC equations. HC equations using body composition data were well-correlated to each other. If HC estimated with HC_Eq4 was regarded as a standard, interestingly, the BSA and weight independently contributed to the variation of HC. The model composed of weight, BSA, and gender was able to predict more than a 99% variation of HC_Eq4. Validation analysis on the test set showed a very high satisfactory level of the predictive model. In conclusion, our results suggest that gender, BSA, and weight are the independent factors for calculating HC. For the first time, a predictive equation based on anthropometry data was developed and this equation could be useful for estimating HC in the general Korean population without body-composition measurement.

  1. Heat capacity changes associated with guanine quadruplex formation: an isothermal titration calorimetry study.

    Science.gov (United States)

    Majhi, Pinaki R; Qi, Jianying; Tang, Chung-Fei; Shafer, Richard H

    2008-04-01

    This study addresses the temperature dependence of the enthalpy of formation for several unimolecular quadruplexes in the presence of excess monovalent salt. We examined a series of biologically significant guanine-rich DNA sequences: thrombin binding aptamer (TBA) (d(G(2)T(2)G(2)TGTG(2)T(2)G(2)), PS2.M, a catalytically active aptamer (d(GTG(3)TAG(3)CG(3)T(2)G(2))), and the human telomere repeat (HT) (d(AG(3)(T(2)AG(3))(3))). Using CD spectra and UV melting, we confirmed the presence of quadruplex structures and established the temperature range in which quadruplex conformation is stable. We then performed ITC experiments, adding DNA to a solution containing excess NaCl or KCl. In this approach, only several additions are made, and only the enthalpy of quadruplex formation is measured. This measurement was repeated at different temperatures to determine the temperature dependence of the enthalpy change accompanying quadruplex formation. To control for the effect of nonspecific salt interactions during DNA folding, we repeated the experiment by replacing the quadruplex-forming sequences with a similar but nonfolding sequence. Dilution enthalpies were also subtracted to obtain the final enthalpy value involving only the quadruplex folding process. For all sequences studied, quadruplex formation was exothermic but with an increasing magnitude with increasing temperature. These results are discussed in terms of the change in heat capacity associated with quadruplex formation.

  2. Measuring the antioxidant capacity of blood plasma using potentiometry.

    Science.gov (United States)

    Tessutti, L S; Macedo, D V; Kubota, L T; Alves, A A

    2013-10-15

    The use of potentiometry to measure plasma antioxidant capacity to contribute to oxidative stress evaluation is presented. In this assay, plasma (n=60) diluted (0.3 to 1 ml) in phosphate buffer, pH 7.4, NaCl 9%, was submitted to potentiometry. A platinum wire was the working electrode and saturated calomel the reference. The results are presented as the difference between sample and buffer potential (ΔE). ΔE presented a good inverse correlation with added increasing concentrations of ascorbate (2.5-75 μmol/L; R=-0.99), urate (9.0-150 μmol/L; R=-0.99), and bilirubin (0.78-13 μmol/L; R=-0.99). Increase in the antioxidant capacity decreased ΔE. Depletion of the antioxidant capacity by tert-butylhydroperoxide (6.5-50 μmol/L) presented a direct correlation (0.97) with ΔE. Furthermore, ΔE presented an inverse correlation (R=-0.99) with increased antioxidant capacity of plasma (FRAP) induced by the addition of ascorbate (2.5-75 μmol/L). The response of the potentiometric method proved be adequate for measuring the plasma antioxidant depletion induced by acute exhaustive exercise in rats (control, n=15; exercised, n=15). This exercise decreased the concentration of urate (ppotentiometry for evaluating the antioxidant capacity of blood plasma samples. Copyright © 2013 Elsevier Inc. All rights reserved.

  3. Heat capacity, lattice dynamics, and thermodynamic stability of the negative thermal expansion material HfMo2O8

    Science.gov (United States)

    Kennedy, Catherine A.; White, Mary Anne; Wilkinson, Angus P.; Varga, Tamas

    2007-06-01

    We explore the lattice dynamics of the negative thermal expansion material, cubic HfMo2O8 , through analysis of its heat capacity (measured from 0.5to300K ) and its room-temperature Raman spectrum. Its heat capacity is quantitatively very similar to that of ZrW2O8 , as is its Raman spectrum. The heat capacity of HfMo2O8 can be well represented by the present lattice dynamical assignment and by CP(HfW2O8)-CP(ZrW2O8)+CP(ZrMo2O8) , but not by CP(HfO2)+2CP(MoO3) , likely because the AB2O8 compounds have low-frequency optic modes, not present in HfO2 and MoO3 . The present thermodynamic data also allow an analysis of the thermodynamic stability of cubic HfMo2O8 , and it is shown to be unstable with respect to MoO3 and HfO2 at room temperature.

  4. The determination of values of the specific heat capacity of the selected thermal insulation materials used in track bed structure

    Directory of Open Access Journals (Sweden)

    Dobeš Peter

    2017-01-01

    Full Text Available The report concentrates on the determination of the specific heat capacity of the selected thermal insulation materials (liapor, styrodur, foam concrete. The aim of the report is to gain the necessary input parameters for the numerical modelling of the temperature changes of various track bed structures of the railway line where a part or, if appropriate, the whole protective layer is replaced by the material with better thermal insulation properties. There are described the methods for stating the specific heat capacity as well as the calibration of the calorimeter for stating of the calorimetric constant in the introduction of the report. The parameters needed for calculation of the specific heat capacity of the selected thermal insulation materials are characterized in the second part of the report. There are also introduced the laboratory stated values of the parameter in question. The comparison of the values stated by the laboratory measurements with the values introduced in the technical data sheets from their producers (or if appropriate gained from the foreign sources is made in the conclusion of the report.

  5. Force Exertion Capacity Measurements in Haptic Virtual Environments

    Science.gov (United States)

    Munih, Marko; Bardorfer, Ales; Ceru, Bojan; Bajd, Tadej; Zupan, Anton

    2010-01-01

    An objective test for evaluating functional status of the upper limbs (ULs) in patients with muscular distrophy (MD) is presented. The method allows for quantitative assessment of the UL functional state with an emphasis on force exertion capacity. The experimental measurement setup and the methodology for the assessment of maximal exertable force…

  6. Final Report: Cooling Seasonal Energy and Peak Demand Impacts of Improved Duct Insulation on Fixed-Capacity (SEER 13) and Variable-Capacity (SEER 22) Heat Pumps

    Energy Technology Data Exchange (ETDEWEB)

    Withers, C. [Building America Partnership for Improved Residential Construction, Cocoa, FL (United States); Florida Solar Energy Center (FSEC), Cocoa, FL (United States); Cummings, J. [Building America Partnership for Improved Residential Construction, Cocoa, FL (United States); Florida Solar Energy Center (FSEC), Cocoa, FL (United States); Nigusse, B. [Building America Partnership for Improved Residential Construction, Cocoa, FL (United States); Florida Solar Energy Center (FSEC), Cocoa, FL (United States)

    2016-09-01

    A new generation of full variable-capacity, central, ducted air-conditioning (AC) and heat pump units has come on the market, and they promise to deliver increased cooling (and heating) efficiency. They are controlled differently than standard single-capacity (fixed-capacity) systems. Instead of cycling on at full capacity and then cycling off when the thermostat is satisfied, they can vary their capacity over a wide range (approximately 40% to 118% of nominal full capacity), thus staying “on” for up to twice as many hours per day compared to fixed-capacity systems of the same nominal capacity. The heating and cooling capacity is varied by adjusting the indoor fan air flow rate, compressor, and refrigerant flow rate as well as the outdoor unit fan air flow rate. Note that two-stage AC or heat pump systems were not evaluated in this research effort. The term dwell is used to refer to the amount of time distributed air spends inside ductwork during space-conditioning cycles. Longer run times mean greater dwell time and therefore greater exposure to conductive gains and losses.

  7. Final Report: Cooling Seasonal Energy and Peak Demand Impacts of Improved Duct Insulation on Fixed-Capacity (SEER 13) and Variable-Capacity (SEER 22) Heat Pumps

    Energy Technology Data Exchange (ETDEWEB)

    Withers, C. [Building America Partnership for Improved Residential Construction, Cocoa, FL (United States); Florida Solar Energy Center, Cocoa, FL (United States); Cummings, J. [Building America Partnership for Improved Residential Construction, Cocoa, FL (United States); Florida Solar Energy Center, Cocoa, FL (United States); Nigusse, B. [Building America Partnership for Improved Residential Construction, Cocoa, FL (United States); Florida Solar Energy Center, Cocoa, FL (United States)

    2016-09-08

    A new generation of full variable-capacity, central, ducted air-conditioning (AC) and heat pump units has come on the market, and they promise to deliver increased cooling (and heating) efficiency. They are controlled differently than standard single-capacity (fixed-capacity) systems. Instead of cycling on at full capacity and then cycling off when the thermostat is satisfied, they can vary their capacity over a wide range (approximately 40% to 118% of nominal full capacity), thus staying “on” for up to twice as many hours per day compared to fixed-capacity systems of the same nominal capacity. The heating and cooling capacity is varied by adjusting the indoor fan air flow rate, compressor, and refrigerant flow rate as well as the outdoor unit fan air flow rate. Note that two-stage AC or heat pump systems were not evaluated in this research effort. The term dwell is used to refer to the amount of time distributed air spends inside ductwork during space-conditioning cycles. Longer run times mean greater dwell time and therefore greater exposure to conductive gains and losses.

  8. Prediction of heat capacities and heats of vaporization of organic liquids by group contribution methods

    DEFF Research Database (Denmark)

    Ceriani, Roberta; Gani, Rafiqul; Meirelles, A.J.A.

    2009-01-01

    for 86 types of substances) included fatty compounds, such as fatty acids, esters, alcohols and triacylglycerols, and hydrocarbons. The performance of this method is compared with other published group contribution methods [Z. Kolska, J. Kukal, M. Zabransky, V. Ruzicka Ind. Eng. Chem. Res. 47 (2008) 2075......-2085] and the Rowlinson-Bondi equation. Also, the predictive performance of general correlations of heats of vaporization based on the corresponding-states method, such as Carruth and Kobayashi [G.F. Carruth, R. Kobayashi, Ind. Eng. Chem. Fundam. 11 (1972) 509-516], Sivaraman et al. [A. Sivaraman, J.W. Magee, R...... in the prediction of heats of vaporization of fatty compounds based on the vapor pressure model of Ceriani and Meirelles [R. Ceriani. A.J.A. Meirelles, Fluid Phase Equilib. 215 (2004) 227-236] and its combination with the Clausius-Clapeyron equation has been Studied. (C) 2009 Elsevier B.V. All rights reserved....

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

    DEFF Research Database (Denmark)

    Sørensen, Lars Schiøtt

    2013-01-01

    and cooling our houses. There is a huge energy-saving potential in this area for reducing both the global climate problems as well as economy challenges. Heating of buildings in Denmark accounts for approximately 40% of the entire national energy consumption. For this reason, a reduction of heat losses from...... and mechanical ventilation in the “warm countries” contribute to an enormous energy consumption and corresponding CO2 emission. In order to establish the best basis for upgrading the energy performance, it is important to make measurements of the heat losses at different places on a building facade, in order......Global energy efficiency can be obtained in two ordinary ways. One way is to improve the energy production and supply side, and the other way is, in general, to reduce the consumption of energy in society. This paper has focus on the latter and especially the consumption of energy for heating...

  10. Meteorological insights from planetary heat flow measurements

    Science.gov (United States)

    Lorenz, Ralph D.

    2015-04-01

    Planetary heat flow measurements are made with a series of high-precision temperature sensors deployed in a column of regolith to determine the geothermal gradient. Such sensors may, however, be susceptible to other influences, especially on worlds with atmospheres. First, pressure fluctuations at the surface may pump air in and out of pore space leading to observable, and otherwise unexpected, temperature fluctuations at depth. Such pumping is important in subsurface radon and methane transport on Earth: evidence of such pumping may inform understanding of methane or water vapor transport on Mars. Second, the subsurface profile contains a muted record of surface temperature history, and such measurements on other worlds may help constrain the extent to which Earth's Little Ice Age was directly solar-forced, versus volcanic-driven and/or amplified by climate feedbacks.

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

    Directory of Open Access Journals (Sweden)

    Lars Schiøtt Sørensen

    2013-08-01

    Full Text Available Global energy efficiency can be obtained in two ordinary ways. One way is to improve the energy production and supply side, and the other way is, in general, to reduce the consumption of energy in society. This paper has focus on the latter and especially the consumption of energy for heating and cooling our houses. There is a huge energy-saving potential in this area for reducing both the global climate problems as well as economy challenges. Heating of buildings in Denmark accounts for approximately 40% of the entire national energy consumption. For this reason, a reduction of heat losses from building envelopes are of great importance in order to reach the Bologna CO2 emission reduction targets. Upgrading of the energy performance of buildings is a topic of huge global interest these years. Not only heating in the temperate and arctic regions are important, but also air conditioning and mechanical ventilation in the “warm countries” contribute to an enormous energy consumption and corresponding CO2 emission. In order to establish the best basis for upgrading the energy performance, it is important to make measurements of the heat losses at different places on a building facade, in order to optimize the energy performance. This paper presents a method for measuring the heat loss by utilizing a U-value meter. The U-value meter measures the heat transfer in the unit W/Km2 and has been used in several projects to upgrade the energy performance in temperate regions. The U-value meter was also utilized in an EUDP (Energy Technological Development and Demonstration Program focusing on renovation of houses from the 1960s and 1970s.

  12. Measurement of heat transfer coefficient using termoanemometry methods

    Directory of Open Access Journals (Sweden)

    Dančová P.

    2014-03-01

    Full Text Available This work deals with a measurement of heat transfer from a heated flat plate on which a synthetic jet impacts perpendicularly. Measurement of a heat transfer coefficient (HTC is carried out using the hot wire anemometry method with glue film probe Dantec 55M47. The paper brings also results of velocity profiles measurements and turbulence intensity calculations.

  13. Reaction heats and heat capacity changes for intermediate steps of the ATP hydrolysis catalyzed by myosin subfragment 1.

    Science.gov (United States)

    Kodama, T

    1981-03-25

    The interaction of myosin Subfragment 1 with ATP in 0.1 M KCl containing 0.01 M MgCl2 and 0.02 M Tris/HCl (pH 8.0) was studied by microcalorimetry at temperatures of 4, 12, and 23 degrees C so that values of the heat capacity change (delta Cp) could be obtained for intermediate steps of the ATPase cycle. The delta Cp values are large compared to the value for the overall cycle, indicating that large changes in the hydrophobic effect are involved in transitions between different intermediate states. However, the heat capacity changes themselves show peculiar temperature dependences. Thus bindings of ATP and ADP to Subfragment 1, both of which are strongly exothermic processes, take place with large negative delta Cp of about -3 kJK-1 mol-1 between 4 and 12 degrees C but with very small delta Cp of 0.3-0.4 kJ K-1 mol-1 between 12 and 23 degrees C. On the contrary, the delta Cp for the endothermic hydrolysis of ATP bound to Subfragment 1 is positive (congruent to kJK-1 mol-1) in the lower temperature range but strongly negative (congruent to -4 kJK-1 mol-1) in the higher temperature range. The magnitude of delta Cp for the slow Pi dissociation process is similar but its sign is just opposite to that for the hydrolysis. These anomalous changes in the heat capacity may be due to the temperature-induced changes in a balance between large opposing effects which result from distinct, local conformation changes within the Subfragment 1 molecule.

  14. Field Measurements of Heating System Efficiency in Nine Electrically-Heated Manufactured Homes.

    Energy Technology Data Exchange (ETDEWEB)

    Davis, Bob; Siegel, J.; Palmiter, L.; Baylon, D.

    1996-07-01

    This report presents the results of field measurements of heating efficiency performed on nine manufactured homes sited in the Pacific Northwest. The testing procedure collects real-time data on heating system energy use and heating zone temperatures, allowing direct calculation of heating system efficiency.

  15. Development of energy efficient smart module with variable direction of heat flow, heat capacity and surface absorptivity(I)

    Energy Technology Data Exchange (ETDEWEB)

    Chun, W.K.; Lee, Y.J.; Lee, H.J. [Jeju University, Jeju (Korea, Republic of)] [and others

    1996-02-01

    This work has been carried out to develop thermal diode modules with variable direction of heat flow, heat capacity and surface absorptivity. The module can be used for space heating in winter and reduce the cooling load of buildings in summer. this concept could be also utilized for domestic hot water heating. The modules are categorized as follows; (1) Loop Type Smart Module, (2) Bayonet Type Smart Module, (3) Roller Type Smart Module, (4) Plane Tubeless Solar Collector and Storage System Utilizing the Bayonet Concept. Each system generally features either or both of the passive or active schemes. The Loop Type, in particular, is designed with the photo diode and microprocessor to harness the solar energy more aggressively. It is essential to contrive a totally new design concept apart from conventional ones to fully appreciate the availability of the sun`s energy. In this regard, the solar modules under investigation in the present study is of great significance. (author) 29 refs., 65 figs., 5 photos.

  16. Cooling and Heating Season Impacts of Right-Sizing of Fixed- and Variable-Capacity Heat Pumps With Attic and Indoor Ductwork

    Energy Technology Data Exchange (ETDEWEB)

    Cummings, James [Building America Partnership for Improved Residential Construction, Cocoa, FL (United States); Withers, Charles [Building America Partnership for Improved Residential Construction, Cocoa, FL (United States); Kono, Jamie [Building America Partnership for Improved Residential Construction, Cocoa, FL (United States)

    2015-06-24

    A new generation of full variable-capacity air-conditioning (A/C) and heat pump units has come on the market that promises to deliver very high cooling and heating efficiency. The units are controlled differently than standard single-capacity (fixed-capacity) systems. Instead of cycling on at full capacity and cycling off when the thermostat is satisfied, the new units can vary their capacity over a wide range (approximately 40%–118% of nominal full capacity) and stay on for 60%–100% more hours per day than the fixed-capacity systems depending on load-to-capacity ratios. Two-stage systems were not evaluated in this research effort.

  17. Dynamic heat capacity of the east model and of a bead-spring polymer model.

    Energy Technology Data Exchange (ETDEWEB)

    McCoy, John Dwane (New Mexico Institute of Mining and Technology, Socorro, NM); Brown, Jonathan R. (New Mexico Institute of Mining and Technology, Socorro, NM); Adolf, Douglas Brian

    2011-10-01

    In this report we have presented a brief review of the glass transition and one means of characterizing glassy materials: linear and nonlinear thermodynamic oscillatory experiments to extract the dynamic heat capacity. We have applied these methods to the east model (a variation of the Ising model for glass forming systems) and a simple polymeric system via molecular dynamics simulation, and our results match what is seen in experiment. For the east model, since the dynamics are so simple, a mathematical model is developed that matches the simulated dynamics. For the polymeric system, since the system is a simulation, we can instantaneously 'quench' the system - removing all vibrational energy - to separate the vibrational dynamics from dynamics associated with particle rearrangements. This shows that the long-time glassy dynamics are due entirely to the particle rearrangements, i.e. basin jumping on the potential energy landscape. Finally, we present an extension of linear dynamic heat capacity to the nonlinear regime.

  18. Magnetic susceptibility and heat capacity of graphene in two-band Harrison model

    Science.gov (United States)

    Mousavi, Hamze; Bagheri, Mehran; Khodadadi, Jabbar

    2015-11-01

    Using a two-band tight-binding Harrison model and Green's function technique, the influences of both localized σ and delocalized π electrons on the density of states, the Pauli paramagnetic susceptibility, and the heat capacity of a graphene sheet are investigated. We witness an extension in the bandwidth and an increase in the number of Van-Hove singularities as well. As a notable point, besides the magnetic nature which includes diamagnetism in graphene-based nanosystems, a paramagnetic behavior associated with the itinerant π electrons could be occurred. Further, we report a Schottky anomaly in the heat capacity. This study asserts that the contribution of both σ and π electrons play dominant roles in the mentioned physical quantities.

  19. High-temperature heat capacity of samarium and erbium titanates with pyrochlore structure

    Science.gov (United States)

    Denisova, L. T.; Chumilina, L. G.; Denisov, V. M.; Ryabov, V. V.

    2017-12-01

    Titanates Sm2Ti2O7 and Er2Ti2O7 with pyrochlore structure have been prepared by solid-phase synthesis in air from stoichiometric Sm2O3 (Er2O3)-TiO2 mixtures sequentially at 1673 and 1773 K. Hightemperature heat capacity of the oxide compounds has been determined by differential scanning calorimetry. Their thermodynamic properties have been calculated from experimental temperature dependence C p = f( T).

  20. Emulsion stabilizing capacity of intact starch granules modified by heat treatment or octenyl succinic anhydride

    OpenAIRE

    Timgren, Anna; Rayner, Marilyn; Dejmek, Petr; Marku, Diana; Sjöö, Malin

    2013-01-01

    Starch granules are an interesting stabilizer candidate for food-grade Pickering emulsions. The stabilizing capacity of seven different intact starch granules for making oil-in-water emulsions has been the topic of this screening study. The starches were from quinoa; rice; maize; waxy varieties of rice, maize, and barley; and high-amylose maize. The starches were studied in their native state, heat treated, and modified by octenyl succinic anhydride (OSA). The effect of varying the continuous...

  1. Measuring Statistical Capacity Building; A Logical Framework Approach

    OpenAIRE

    Thomas K. Morrison; Sarmad Khawaja

    2001-01-01

    This paper suggests a way forward in the effort to measure statistical capacity building by combining features of two tools – the Project Management System, a logical framework methodology that the IMF Statistics Department uses to plan, monitor, and evaluate technical assistance projects, and the Data Quality Assessment Framework, a methodology for assessing data quality that brings together best practices and internationally accepted concepts and definitions in statistics

  2. Measurements for improvement of running capacity. : Physiological and biomechanical evaluations

    OpenAIRE

    Gullstrand, Lennart

    2009-01-01

    Introduction: Running is included in a large number of sports and one of the most well investigated modes of locomotion in both physiology and biomechanics. This thesis focuses on how some new methods from both areas may be used to capture running capacity in mid-distance and distance running from laboratory and field recordings. Measurement of running economy is included and defined as oxygen uptake at a given submaximal velocity in a steady-state condition. Running economy...

  3. Improved exercise capacity in the heat followed by coconut water consumption

    Directory of Open Access Journals (Sweden)

    Orlando Laitano

    2014-03-01

    Full Text Available The aim of the present study was to assess the effects of prior ingestion of coconut water on fluid retention and exercise capacity in the heat as well as signs of gastrointestinal distress. Eight physically active men were recruited (age 23 ± 3 years, height 176 ± 6 cm, body mass 78 ± 7 kg and performed three exercise capacity trials on a cycle ergometer in the heat (34 ± 1°C after the ingestion of one of the following drinks: a plain water (PW, b flavored drink (FD, and c coconut water (CW. Ingestion of CWresulted in a longer time to exhaustion (p=0.029. Likewise, participants achieved a higher heart rate in the CW session when compared to the other trials (PW 183 ± 5 bpm, FD 184 ± 8 bpm, and CW 189 ± 8 bpm, p<0.05 and a reduced urine output after the coconut water ingestion (PW 214 ± 85 ml, FD 267 ± 90 ml, and CW 161 ± 73 ml, p<0.05 indicating a higher fluid retention of coconut water in comparison to plain water and the flavored drink. These results demonstrate that previous ingestion of coconut water improves exercise capacity in the heat and provide a reduced urine output in comparison to plain water and flavored drink. Also there is no evidence for GI distress.

  4. Prevalence of Temperature Dependent Heat Capacity Changes in Protein-DNA Interactions

    Energy Technology Data Exchange (ETDEWEB)

    Liu, C.-C.; Richard, A.J.; Kausiki, D.; LiCata, V.J.

    2009-05-19

    A large, negative {Delta}Cp of DNA binding is a thermodynamic property of the majority of sequence-specific DNA-protein interactions, and a common, but not universal property of non-sequence-specific DNA binding. In a recent study of the binding of Taq polymerase to DNA, we showed that both the full-length polymerase and its 'Klentaq' large fragment bind to primed-template DNA with significant negative heat capacities. Herein, we have extended this analysis by analyzing this data for temperature-variable heat capacity effects ({Delta}{Delta}Cp), and have similarly analyzed an additional 47 protein-DNA binding pairs from the scientific literature. Over half of the systems examined can be easily fit to a function that includes a {Delta}{Delta}Cp parameter. Of these, 90% display negative {Delta}{Delta}Cp values, with the result that the {Delta}Cp of DNA binding will become more negative with rising temperature. The results of this collective analysis have potentially significant consequences for current quantitative theories relating {Delta}Cp values to changes in accessible surface area, which rely on the assumption of temperature invariance of the {Delta}Cp of binding. Solution structural data for Klentaq polymerase demonstrate that the observed heat capacity effects are not the result of a coupled folding event.

  5. Application of Neumann-Kopp rule for the estimation of heat capacity of mixed oxides

    Energy Technology Data Exchange (ETDEWEB)

    Leitner, J., E-mail: jindrich.leitner@vscht.cz [Department of Solid State Engineering, Institute of Chemical Technology Prague, Technicka 5, 166 28 Prague 6 (Czech Republic); Vonka, P. [Department of Physical Chemistry, Institute of Chemical Technology Prague, Technicka 5, 166 28 Prague 6 (Czech Republic); Sedmidubsky, D. [Department of Inorganic Chemistry, Institute of Chemical Technology Prague, Technicka 5, 166 28 Prague 6 (Czech Republic); European Commission, JRC, Institute for Transuranium Elements, Postbox 2340, D-76125 Karlsruhe (Germany); Svoboda, P. [Department of Condensed Matter Physics, Faculty of Mathematics and Physics, Charles University, Ke Karlovu 5, 120 00 Prague 2 (Czech Republic)

    2010-01-10

    The empirical Neumann-Kopp rule (NKR) for the estimation of temperature dependence of heat capacity of mixed oxide is analyzed. NKR gives a reasonable estimate of C{sub pm} for most mixed oxides around room temperature, but at both low and high temperatures the accuracy of the estimate is substantially lowered. At very low temperatures, the validity of NKR is shown to be predominantly determined by the relation between the characteristic Debye and Einstein temperatures of a mixed oxide and its constituents. At high temperatures, the correlation between their molar volumes, volume expansion coefficients and compressibilities takes the dominance. In cases where the formation of a mixed oxide is not accompanied by any volume change, the difference between dilatation contributions to heat capacity of a mixed oxide and its constituents is exclusively negative. It turns out that in the high-temperature range, where the contribution of harmonic lattice vibrations approached the 3NR limit, {Delta}{sub ox}C{sub p} assumes negative values. For more complex oxides whose heat capacity has contributions from terms such as magnetic ordering, electronic excitations, the applicability of NKR is only restricted to lattice and dilatation terms.

  6. On the reliability of negative heat capacity measurements

    Science.gov (United States)

    D'Agostino, M.; Bougault, R.; Gulminelli, F.; Bruno, M.; Cannata, F.; Chomaz, Ph.; Gramegna, F.; Iori, I.; Le Neindre, N.; Margagliotti, G. V.; Moroni, A.; Vannini, G.

    2002-03-01

    A global protocol for the thermostatistical analysis of hot nuclear sources is discussed. Within our method of minimization of variances we show that the abnormal kinetic energy fluctuation signal recently reported in different experimental data from the MULTICS and INDRA collaborations is a genuine signal of a first-order phase transition in a finite system.

  7. Heat capacity jumps induced by magnetic field in the Er{sub 2}HoAl{sub 5}O{sub 12} garnet

    Energy Technology Data Exchange (ETDEWEB)

    Shevchenko, E.V. [Centre for Diagnostics of Functional Materials for Medicine, Pharmacology and Nanoelectronics, St. Petersburg State University, St. Petersburg, 198504 (Russian Federation); Charnaya, E.V., E-mail: charnaya@live.com [Physics Department, St. Petersburg State University, St. Petersburg, 198504 (Russian Federation); Lee, M.K. [Department of Physics, National Cheng Kung University, Tainan, 70101 Taiwan (China); NSC Instrument Center at NCKU, Tainan, 70101 Taiwan (China); Chang, L.J. [Department of Physics, National Cheng Kung University, Tainan, 70101 Taiwan (China); Khazanov, E.N.; Taranov, A.V. [Kotel' nikov Institute of Radio Engineering and Electronics RAS, 125009 (Russian Federation); Bugaev, A.S. [Moscow Institute of Physics and Technology, Moscow, 141700 (Russian Federation)

    2017-01-30

    Measurements of the heat capacity were carried out for the mixed Er{sub 2}HoAl{sub 5}O{sub 12} garnet at magnetic fields up to 15 T. The heat capacity variations at low temperatures were dominated by the Schottky anomalies. In addition, anomalous sharp steps in the heat capacity were observed in magnetic fields stronger than 8 T upon cooling as well as upon warming. The temperatures of the steps increased with increasing magnetic field. Jumps found upon cooling and warming were shifted relative to each other showing the thermal hysteresis. The sharp decrease in the heat capacity at low temperatures suggested the blocking of magnetic flips induced by strong enough magnetic fields. - Highlights: • Anomalous steps of the heat capacity were observed in the Er{sub 2}HoAl{sub 5}O{sub 12} garnet. • The steps are induced by magnetic field at low temperatures. • The temperatures of the steps increased with increasing magnetic field. • The steps show a pronounced thermal hysteresis. • The findings suggest the blocking of the magnetic moment flips at field.

  8. Molar Heat Capacity (Cv) for Saturated and Compressed Liquid and Vapor Nitrogen from 65 to 300 K at Pressures to 35 MPa.

    Science.gov (United States)

    Magee, J W

    1991-01-01

    Molar heat capacities at constant volume (Cv ,) for nitrogen have been measured with an automated adiabatic calorimeter. The temperatures ranged from 65 to 300 K, while pressures were as high as 35 MPa. Calorimetric data were obtained for a total of 276 state conditions on 14 isochores. Extensive results which were obtained in the saturated liquid region (Cv((2)) and Cσ ) demonstrate the internal consistency of the Cv (ρ,T) data and also show satisfactory agreement with published heat capacity data. The overall uncertainty of the Cv values ranges from 2% in the vapor to 0.5% in the liquid.

  9. Army Solid State Laser Program: Design, Operation, and Mission Analysis for a Heat-Capacity Laser

    Energy Technology Data Exchange (ETDEWEB)

    Dane, C B; Flath, L; Rotter, M; Fochs, S; Brase, J; Bretney, K

    2001-05-18

    of operation is ideally suited for applications that require 1-30s engagements at very high average power. If necessary, multiple laser apertures can provide continuous operation. Land Combat mission analysis of a stressing air defense scenario including a dense attack of rockets, mortars, and artillery has indicated that multiple HEL weapon systems, based on the solid state, heat capacity laser concept, can provide significantly improved protection of high value battlefield assets. We will present EADSIM results for two government-supplied scenarios, one with temporally high threat density over a fairly large defended area, and one with fewer threats concentrating on a single defended asset. Implications for weapon system requirements will be presented. In order to demonstrate the operation of a high average power heat-capacity laser system, we have developed a flashlamp-pumped Nd:glass laser with output energies in the range of 500-1000J/pulse in a 10 x 10cm{sup 2} beam. With a repetition frequency of 20Hz, an average power of 13kW has been demonstrated for operational periods of up to 10s using a stable optical resonator (see enclosed figure). Using an M=1.4 unstable resonator, a beam divergence of 5X diffraction-limited has been measured with no active wavefront correction. An adaptively corrected unstable resonator that incorporates an intracavity deformable mirror controlled by feedback from an external wavefront sensor will provide <2X diffraction-limited output integrated over an entire 10s run at an average power of 10kW. A very similar laser architecture in which the Nd:glass is replaced by Nd:GGG and the flashlamps are replaced by large diode-laser arrays will enable the scaling of the output average power from the demonstrated 10kW to 100kW (500J/pulse at 200Hz). Risk reduction experiments for diode-pumped Nd:GGG, the fabrication of large Nd:GGG amplifier slabs, as well as the progress toward a sub-scale amplifier testbed pumped by diode arrays with total

  10. Improving public health preparedness capacity measurement: development of the local health department preparedness capacities assessment survey.

    Science.gov (United States)

    Davis, Mary V; Mays, Glen P; Bellamy, James; Bevc, Christine A; Marti, Cammie

    2013-12-01

    To address limitations in measuring the preparedness capacities of health departments, we developed and tested the Local Health Department Preparedness Capacities Assessment Survey (PCAS). Preexisting instruments and a modified 4-cycle Delphi panel process were used to select instrument items. Pilot test data were analyzed using exploratory factor analysis. Kappa statistics were calculated to examine rater agreement within items. The final instrument was fielded with 85 North Carolina health departments and a national matched comparison group of 248 health departments. Factor analysis identified 8 initial domains: communications, surveillance and investigation, plans and protocols, workforce and volunteers, legal infrastructure, incident command, exercises and events, and corrective action. Kappa statistics and z scores indicated substantial to moderate agreement among respondents in 7 domains. Cronbach α coefficients ranged from 0.605 for legal infrastructure to 0.929 for corrective action. Mean scores and standard deviations were also calculated for each domain and ranged from 0.41 to 0.72, indicating sufficient variation in the sample to detect changes over time. The PCAS is a useful tool to determine how well health departments are performing on preparedness measures and identify opportunities for future preparedness improvements. Future survey implementation will incorporate recent Centers for Disease Control and Prevention's Public Health Preparedness Capabilities: National Standards for State and Local Planning.

  11. A new experimental method to determine specific heat capacity of inhomogeneous concrete material with incorporated microencapsulated-PCM

    DEFF Research Database (Denmark)

    Pomianowski, Michal Zbigniew; Heiselberg, Per; Jensen, Rasmus Lund

    2014-01-01

    The study presented in this paper focuses on an experimental investigation of the specific heat capacity as a function of the temperature Cp (T) of concrete mixed with various amounts of phase change material (PCM). The tested specimens are prepared by directly mixing concrete and microencapsulated...... PCM. This paper describes the development of the new material and the experimental set-up to determine the specific heat capacity of the PCM concrete material. Moreover, various methods are proposed and compared to calculate the specific heat capacity of the PCM concrete. Finally, it is hoped...

  12. Power Output Stability Research for Harvesting Automobile Exhaust Energy with Heat Capacity Material as Intermediate Medium

    Science.gov (United States)

    Xiao, Longjie; He, Tianming; Mei, Binyu; Wang, Yiping; Wang, Zongsong; Tan, Gangfeng

    2018-01-01

    Automobile exhaust energy thermoelectric utilization can promote energy-saving and emission-reduction. Unexpected urban traffic conditions lead to the hot-end temperature instability of the exhaust pipe-mounted thermoelectric generator (TEG), and influence the TEG power generation efficiency. The heat conduction oil circulation located at the hot-end could smooth the temperature fluctuation, at the expense of larger system size and additional energy supply. This research improves the TEG hot-end temperature stability by installing solid heat capacity material (SHCM) to the area between the outer wall of the exhaust pipe and the TEG, which has the merits of simple structure, light weight and no additional energy consumption. The exhaust temperature and flow rate characteristics with various driving conditions are firstly studied for the target engine. Then the convective heat transfer models of SHCM's hot-end and thermoelectric material's cold-end are established. Meanwhile, SHCM thermal properties' effects on the amplitude and response speed of the TEG hot-end temperature are studied. The candidate SHCM with the characteristics of low thermal resistance and high heat capacity is determined. And the heat transfer model going through from TEG's hot-end to the cold-end is established. The results show that the SHCM significantly improves the TEG hot-end temperature stability but slightly reduces the average power output. When the engine working conditions change a lot, the SHCM's improvement on the TEG hot-end temperature stability is more significant, but the reduction of the average power output becomes more remarkable.

  13. IMP improves water-holding capacity, physical and sensory properties of heat-induced gels from porcine meat.

    Science.gov (United States)

    Nakamura, Yukinobu; Migita, Koshiro; Okitani, Akihiro; Matsuishi, Masanori

    2014-05-01

    Water-holding capacity (WHC) of heat-induced pork gels was examined. The heat-induced gels were obtained from meat homogenates prepared by adding nine volumes of 0.3-0.5 mol/L NaCl solutions containing 9-36 mmol/L disodium inosine-5'-monophosphate (IMP) or 9 mmol/L tetrapotassium pyrophosphate (KPP) to minced pork. IMP at 36 mmol/L enhanced the WHC to the same level as attained by KPP. Physical and sensory properties of heat-induced gels were also examined. The heat-induced gels were prepared from porcine meat homogenates containing 0.3 mol/L NaCl and 9-36 mmol/L IMP or 9 mmol/L KPP. IMP at 36 mmol/L enhanced the values of hardness, cohesiveness, gumminess and springiness, measured with a Tensipresser, and several organoleptic scores to the same level as the score attained by KPP. Thus, it is concluded that IMP is expected to be a practical substitute for pyrophosphates to improve the quality of sausages. © 2014 Japanese Society of Animal Science.

  14. Guide for the calculation of heating capacity and heating coils for deep tanks / Handleiding bij de berekening van verwarmingskapasiteit en spiraallengte voor dieptanks

    NARCIS (Netherlands)

    Heeden, D.J. van der; Koppenol, A.D.

    1972-01-01

    This report deals with a method for calculating the heating capacity and the length of heating coils, required for deep tanks in dry cargo ships. It is based on the theory of natural convection and on experiments, carried out on tanks loaded with mineral oils. The calculating method is set up for

  15. Exercise capacity in the heat is greater in the morning than in the evening in man.

    Science.gov (United States)

    Hobson, Ruth M; Clapp, Emma L; Watson, Phillip; Maughan, Ronald J

    2009-01-01

    This study investigated the effect of time of day on endurance exercise capacity in a warm environment. Nine males cycled to exhaustion at 65% .VO2peak in an ambient temperature of 35 degrees C (60% relative humidity) at 0645 h (AM) and 1845 h (PM). Rectal temperature (Tc), skin temperature (Tsk), and heart rate (HR) were recorded and blood and expired air samples collected at rest every 5 min during exercise and during recovery. Time to exhaustion was longer in the AM trial (45.8 +/- 10.7 min) than in the PM trial (40.5 +/- 9.0 min; P = 0.009). Resting Tc was lower in the AM trial and remained lower for the first 25 min of exercise (P exercise (P exercise capacity in the heat was significantly greater in the morning than the evening, possibly due to a lower initial Tc.

  16. Thermal analysis method of high capacity communications satellite with heat pipes

    Science.gov (United States)

    Tsunoda, Hiroaki; Nakajima, Katsuhiko; Miyasaka, Akihiro

    Thermal analysis method for heat pipe embedded communications equipment panel is treated in this paper. The main problem of the thermal analysis is how to construct the mathematical model under the limitation of computer CPU memory size. The mathematical model for the heat pipe embedded panel is first established based on the experiments. The essence of this method is to divide panel area into several small regions and perform thermal analysis independently using the fact of low thermal conductivity of honeycomb sandwich panel. To check the correctness of this method, the experiment using the test panel which thermally simulates the north communications equipment panel of two-ton class high capacity communications satellite has been conducted. The experiment shows the method works well.

  17. Heat capacities of xenotime-type ceramics: An accurate ab initio prediction

    Science.gov (United States)

    Ji, Yaqi; Beridze, George; Bosbach, Dirk; Kowalski, Piotr M.

    2017-10-01

    Because of ability to incorporate actinides into their structure, the lanthanide phosphate ceramics (LnPO4) are considered as potential matrices for the disposal of nuclear waste. Here we present highly reliable ab initio prediction of the variation of heat capacities and the standard entropies of these compounds in zircon structure along lanthanide series (Ln = Dy, …,Lu) and validate them against the existing experimental data. These data are helpful for assessment of thermodynamic parameters of these materials in the context of using them as matrices for immobilization of radionuclides for the purpose of nuclear waste management.

  18. Analytical evaluation of thermal conductance and heat capacities of one-dimensional material systems

    Energy Technology Data Exchange (ETDEWEB)

    Saygi, Salih [Department of Physics, Gaziosmanpasa University, Tokat, 60200 Turkey (Turkey)

    2014-02-15

    We theoretically predict some thermal properties versus temperature dependence of one dimensional (1D) material nanowire systems. A known method is used to provide an efficient and reliable analytical procedure for wide temperature range. Predicted formulas are expressed in terms of Bloch-Grüneisen functions and Debye functions. Computing results has proved that the expressions are in excellent agreement with the results reported in the literature even if it is in very low dimension limits of nanowire systems. Therefore the calculation method is a fully predictive approach to calculate thermal conductivity and heat capacities of nanowire material systems.

  19. [Measurement of CO diffusion capacity (II): Standardization and quality criteria].

    Science.gov (United States)

    Salcedo Posadas, A; Villa Asensi, J R; de Mir Messa, I; Sardón Prado, O; Larramona, H

    2015-08-01

    The diffusion capacity is the technique that measures the ability of the respiratory system for gas exchange, thus allowing a diagnosis of the malfunction of the alveolar-capillary unit. The most important parameter to assess is the CO diffusion capacity (DLCO). New methods are currently being used to measure the diffusion using nitric oxide (NO). There are other methods for measuring diffusion, although in this article the single breath technique is mainly referred to, as it is the most widely used and best standardized. Its complexity, its reference equations, differences in equipment, inter-patient variability and conditions in which the DLCO is performed, lead to a wide inter-laboratory variability, although its standardization makes this a more reliable and reproductive method. The practical aspects of the technique are analyzed, by specifying the recommendations to carry out a suitable procedure, the calibration routine, calculations and adjustments. Clinical applications are also discussed. An increase in the transfer of CO occurs in diseases in which there is an increased volume of blood in the pulmonary capillaries, such as in the polycythemia and pulmonary hemorrhage. There is a decrease in DLCO in patients with alveolar volume reduction or diffusion defects, either by altered alveolar-capillary membrane (interstitial diseases) or decreased volume of blood in the pulmonary capillaries (pulmonary embolism or primary pulmonary hypertension). Other causes of decreased or increased DLCO are also highlighted. Copyright © 2014 Asociación Española de Pediatría. Published by Elsevier España, S.L.U. All rights reserved.

  20. Towards Systematic Prediction of Urban Heat Islands: Grounding Measurements, Assessing Modeling Techniques

    Directory of Open Access Journals (Sweden)

    Jackson Voelkel

    2017-06-01

    Full Text Available While there exists extensive assessment of urban heat, we observe myriad methods for describing thermal distribution, factors that mediate temperatures, and potential impacts on urban populations. In addition, the limited spatial and temporal resolution of satellite-derived heat measurements may limit the capacity of decision makers to take effective actions for reducing mortalities in vulnerable populations whose locations require highly-refined measurements. Needed are high resolution spatial and temporal information for urban heat. In this study, we ask three questions: (1 how do urban heat islands vary throughout the day? (2 what statistical methods best explain the presence of temperatures at sub-meter spatial scales; and (3 what landscape features help to explain variation in urban heat islands? Using vehicle-based temperature measurements at three periods of the day in the Pacific Northwest city of Portland, Oregon (USA, we incorporate LiDAR-derived datasets, and evaluate three statistical techniques for modeling and predicting variation in temperatures during a heat wave. Our results indicate that the random forest technique best predicts temperatures, and that the evening model best explains the variation in temperature. The results suggest that ground-based measurements provide high levels of accuracy for describing the distribution of urban heat, its temporal variation, and specific locations where targeted interventions with communities can reduce mortalities from heat events.

  1. Dynamic measurement of near-field radiative heat transfer

    OpenAIRE

    Lang, S.; G. Sharma; Molesky, S.; Kränzien, P. U.; Jalas, T.; Z. Jacob; Petrov, A. Yu.; Eich, M.

    2017-01-01

    Super-Planckian near-field radiative heat transfer allows effective heat transfer between a hot and a cold body to increase beyond the limits long known for black bodies. Until present, experimental techniques to measure the radiative heat flow relied on steady-state systems. Here, we present a dynamic measurement approach based on the transient plane source technique, which extracts thermal properties from a temperature transient caused by a step input power function. Using this versatile me...

  2. Using a Cold Radiometer to Measure Heat Loads and Survey Heat Leaks

    Science.gov (United States)

    Dipirro, M.; Tuttle, J.; Hait, T.; Shirron, P.

    2014-01-01

    We have developed an inexpensive cold radiometer for use in thermal/vacuum chambers to measure heat loads, characterize emissivity and specularity of surfaces and to survey areas to evaluate stray heat loads. We report here the results of two such tests for the James Webb Space Telescope to measure heat loads and effective emissivities of 2 major pieces of optical ground support equipment that will be used in upcoming thermal vacuum testing of the Telescope.

  3. Inspiratory Capacity during Exercise: Measurement, Analysis, and Interpretation

    Directory of Open Access Journals (Sweden)

    Jordan A. Guenette

    2013-01-01

    Full Text Available Cardiopulmonary exercise testing (CPET is an established method for evaluating dyspnea and ventilatory abnormalities. Ventilatory reserve is typically assessed as the ratio of peak exercise ventilation to maximal voluntary ventilation. Unfortunately, this crude assessment provides limited data on the factors that limit the normal ventilatory response to exercise. Additional measurements can provide a more comprehensive evaluation of respiratory mechanical constraints during CPET (e.g., expiratory flow limitation and operating lung volumes. These measurements are directly dependent on an accurate assessment of inspiratory capacity (IC throughout rest and exercise. Despite the valuable insight that the IC provides, there are no established recommendations on how to perform the maneuver during exercise and how to analyze and interpret the data. Accordingly, the purpose of this manuscript is to comprehensively examine a number of methodological issues related to the measurement, analysis, and interpretation of the IC. We will also briefly discuss IC responses to exercise in health and disease and will consider how various therapeutic interventions influence the IC, particularly in patients with chronic obstructive pulmonary disease. Our main conclusion is that IC measurements are both reproducible and responsive to therapy and provide important information on the mechanisms of dyspnea and exercise limitation during CPET.

  4. Quantum thermodynamics from the nonequilibrium dynamics of open systems: Energy, heat capacity, and the third law

    Science.gov (United States)

    Hsiang, J.-T.; Chou, C. H.; Subaşı, Y.; Hu, B. L.

    2018-01-01

    In a series of papers, we intend to take the perspective of open quantum systems and examine from their nonequilibrium dynamics the conditions when the physical quantities, their relations, and the laws of thermodynamics become well defined and viable for quantum many-body systems. We first describe how an open-system nonequilibrium dynamics (ONEq) approach is different from the closed combined system + environment in a global thermal state (CGTs) setup. Only after the open system equilibrates will it be amenable to conventional thermodynamics descriptions, thus quantum thermodynamics (QTD) comes at the end rather than assumed in the beginning. The linkage between the two comes from the reduced density matrix of ONEq in that stage having the same form as that of the system in the CGTs. We see the open-system approach having the advantage of dealing with nonequilibrium processes as many experiments in the near future will call for. Because it spells out the conditions of QTD's existence, it can also aid us in addressing the basic issues in quantum thermodynamics from first principles in a systematic way. We then study one broad class of open quantum systems where the full nonequilibrium dynamics can be solved exactly, that of the quantum Brownian motion of N strongly coupled harmonic oscillators, interacting strongly with a scalar-field environment. In this paper, we focus on the internal energy, heat capacity, and the third law. We show for this class of physical models, amongst other findings, the extensive property of the internal energy, the positivity of the heat capacity, and the validity of the third law from the perspective of the behavior of the heat capacity toward zero temperature. These conclusions obtained from exact solutions and quantitative analysis clearly disprove claims of negative specific heat in such systems and dispel allegations that in such systems the validity of the third law of thermodynamics relies on quantum entanglement. They are

  5. Measuring Upper Limb Capacity in Patients After Stroke : Reliability and Validity of the Stroke Upper Limb Capacity Scale

    NARCIS (Netherlands)

    Houwink, Annemieke; Roorda, Leo D.; Smits, Wendy; Molenaar, Ivo W.; Geurts, Alexander C.

    Houwink A, Roorda LD, Smits W, Molenaar IW, Geurts AC. Measuring upper limb capacity in patients after stroke: reliability and validity of the Stroke Upper Limb Capacity Scale. Arch Phys Med Rehabil 2011;92:1418-22. Objective: To investigate the interrater reliability and construct validity of the

  6. Labworks and the Kundt's Tube: A New Way to Determine the Heat Capacities of Gases

    Science.gov (United States)

    Bryant, Philip A.; Morgan, Matthew E.

    2004-01-01

    The potency of heat in gases is measured by the application of a computer and the LabWorks interaction, while the speed of sound in gases is determined by an instrument called Kundt's tube. This unique and accurate procedure is repeatable, and greatly reduces data acquisition time.

  7. Measuring Credit Capacity on Danish Farms Using DEA

    DEFF Research Database (Denmark)

    Friis Pedersen, Michael; Vesterlund Olsen, Jakob

    2013-01-01

    Purpose:The purpose of this paper is to introduce a novel measure of access to credit suited to estimate the relative change in credit reserves. Design/methodology/approach: A debt possibility frontier is estimated using data envelopment analysis and the Malmquist index is calculated. The Malmquist...... index is redubbed the Debt Development index and decomposed into “change in debt capacity” and “change in debt capacity utilization”. Bootstrapping is applied for statistical inference. The method is applied to an unbalanced panel of 92,000 Danish farm accounts from 1996 to 2009. Findings: The paper...... have important implications for risk management practice, investment and technology adoption and related policy issues. The method is limited by the possibility of strategic behavior of lenders during credit cycle busts. In credit cycle booms, the method gives a good basis for the estimates of change...

  8. Heat flux measurement in SSME turbine blade tester

    Science.gov (United States)

    Liebert, Curt H.

    1990-01-01

    Surface heat flux values were measured in the turbine blade thermal cycling tester located at NASA-Marshall. This is the first time heat flux has been measured in a space shuttle main engine turbopump environment. Plots of transient and quasi-steady state heat flux data over a range of about 0 to 15 MW/sq m are presented. Data were obtained with a miniature heat flux gage device developed at NASA-Lewis. The results from these tests are being incorporated into turbine design models. Also, these gages are being considered for airfoil surface heat flux measurement on turbine vanes mounted in SSME turbopump test bed engine nozzles at Marshall. Heat flux effects that might be observed on degraded vanes are discussed.

  9. Non intrusive measurement of the convective heat transfer coefficient

    Energy Technology Data Exchange (ETDEWEB)

    Rebay, M.; Mebarki, G.; Padet, J. [Reims Univ., Reims (France). Faculty of Science, GRESPI Thermomechanical Lab; Arfaoui, A. [Reims Univ., Reims (France). Faculty of Science, GRESPI Thermomechanical Lab; Tunis Univ., Tunis (Tunisia). Faculty of Science, EL MANAR, LETTM; Maad, B.R. [Tunis Univ., Tunis (Tunisia). Faculty of Science, EL MANAR, LETTM

    2010-07-01

    The efficiency of cooling methods in thermal systems such as radiators and heat exchangers must be improved in order to enhance performance. The evaluation of the heat transfer coefficients between a solid and a fluid is necessary for the control and the dimensioning of thermal systems. In this study, the pulsed photothermal method was used to measure the convective heat transfer coefficient on a solid-fluid interface, notably between an air flow and a heated slab mounted on a PVC flat plate. This configuration simulated the electronic air-cooling inside enclosures and racks. The influence of the deflector's inclination angle on the enhancement of heat transfer was investigated using 2 newly developed identification models. The first model was based on a constant heat transfer coefficient during the pulsed experiment, while the second, improved model was based on a variable heat transfer coefficient. The heat transfer coefficient was deduced from the evolution of the transient temperature induced by a sudden deposit of a luminous energy on the front face of the slab. Temperature evolutions were derived by infrared thermography, a camera for cartography and a detector for precise measurement in specific locations. The results show the improvement of measurement accuracies when using a model that considers the temporal evolution of the convective heat transfer coefficient. The deflection of air flow on the upper surface of the heated slab demonstrated better cooling of the slab by the deflection of air flow. 11 refs., 1 tab., 8 figs.

  10. Repeatability of aerobic capacity measurements in Parkinson disease.

    Science.gov (United States)

    Katzel, Leslie I; Sorkin, John D; Macko, Richard F; Smith, Barbara; Ivey, Frederick M; Shulman, Lisa M

    2011-12-01

    Maximal or peak aerobic capacity (VO(2peak)) during a maximal-effort graded exercise test is considered by many to be the "gold standard" outcome for assessing the effect of exercise training on cardiorespiratory fitness. The reliability of this measure in Parkinson disease (PD) has not been established, where the degree of motor impairment can vary greatly and is influenced by medications. This study examined the reliability of VO(2peak) during a maximal-effort graded exercise test in subjects with PD. Seventy healthy middle-aged and older subjects with PD Hoehn and Yahr stage 1.5-3 underwent a screening/acclimatization maximal-effort treadmill test followed by two additional maximal-effort treadmill tests with repeated measurements of VO(2peak). A third VO(2peak) test was performed in a subset of 21 subjects. The mean VO(2peak) measurement was 2.4% higher in the second test compared with the first test (21.42 ± 4.3 vs 21.93 ± 4.50 mL·kg(-1)·min(-1), mean ± SD, P = 0.03). The intraclass correlation coefficients (ICC) for VO(2peak) expressed either as milliliters per kilogram per minute or as liters per minute were highly reliable, with ICC of 0.90 and 0.94, respectively. The maximum HR (ICC of 0.91) and final speed achieved during the tests (ICC of 0.94) were also highly reliable, with the respiratory quotient being the least reliable of the parameters measured (ICC of 0.65). Our results demonstrate that measurement of VO(2peak) is reliable and repeatable in subjects with mild to moderate PD, thereby validating use of this parameter for assessing the effects of exercise interventions on cardiorespiratory fitness.

  11. Measuring the dimensions of adaptive capacity: a psychometric approach

    Directory of Open Access Journals (Sweden)

    Michael Lockwood

    2015-03-01

    Full Text Available Although previous studies have examined adaptive capacity using a range of self-assessment procedures, no objective self-report approaches have been used to identify the dimensions of adaptive capacity and their relative importance. We examine the content, structure, and relative importance of dimensions of adaptive capacity as perceived by rural landholders in an agricultural landscape in South-Eastern Australia. Our findings indicate that the most important dimensions influencing perceived landholder adaptive capacity are related to their management style, particularly their change orientation. Other important dimensions are individual financial capacity, labor availability, and the capacity of communities and local networks to support landholders' management practices. Trust and confidence in government with respect to native vegetation management was not found to be a significant dimension of perceived adaptive capacity. The scale items presented, particularly those with high factor loadings, provide a solid foundation for assessment of adaptive capacity in other study areas, as well as exploration of relationships between the individual dimensions of adaptive capacity and dependent variables such as perceived resilience. Further work is needed to refine the scale items and compare the findings from this case study with those from other contexts and population samples.

  12. Temperature Dependence of the Molar Heat Capacity for Ferromagnets Within the Mean Field Theory

    Science.gov (United States)

    Fernández Rodríguez, J.; Blanco, J. A.

    2005-01-01

    We describe, using the Mean Field Theory, a detailed analysis of the magnetic contribution to the molar heat capacity Cmag for ferromagnetic systems. This calculation is designed to be used as a teaching homework problem for physics undergraduates. The description emphasises that Cmag at the transition temperature TC is characterised by the existence of a simple jump discontinuity anomaly, but when the temperature is lowered down to 0 K the shape of Cmag depends strongly on the magnitude of the spin S. In fact, the appearance of a shoulder in Cmag for S > 3/2 is expected. The origin of this shoulder could be understood as a Schottky-like anomaly in the ordered state. These physical results are in good agreement with those from real systems, and give the student a valuable insight into the behaviour of the thermodynamical response of a ferromagneticmaterial.

  13. Consistency among integral measurements of aggregate decay heat power

    Energy Technology Data Exchange (ETDEWEB)

    Takeuchi, H.; Sagisaka, M.; Oyamatsu, K.; Kukita, Y. [Nagoya Univ. (Japan)

    1998-03-01

    Persisting discrepancies between summation calculations and integral measurements force us to assume large uncertainties in the recommended decay heat power. In this paper, we develop a hybrid method to calculate the decay heat power of a fissioning system from those of different fissioning systems. Then, this method is applied to examine consistency among measured decay heat powers of {sup 232}Th, {sup 233}U, {sup 235}U, {sup 238}U and {sup 239}Pu at YAYOI. The consistency among the measured values are found to be satisfied for the {beta} component and fairly well for the {gamma} component, except for cooling times longer than 4000 s. (author)

  14. Dynamic measurement of near-field radiative heat transfer.

    Science.gov (United States)

    Lang, S; Sharma, G; Molesky, S; Kränzien, P U; Jalas, T; Jacob, Z; Petrov, A Yu; Eich, M

    2017-10-24

    Super-Planckian near-field radiative heat transfer allows effective heat transfer between a hot and a cold body to increase beyond the limits long known for black bodies. Until present, experimental techniques to measure the radiative heat flow relied on steady-state systems. Here, we present a dynamic measurement approach based on the transient plane source technique, which extracts thermal properties from a temperature transient caused by a step input power function. Using this versatile method, that requires only single sided contact, we measure enhanced radiative conduction up to 16 times higher than the blackbody limit on centimeter sized glass samples without any specialized sample preparation or nanofabrication.

  15. Sensors measure surface ablation rate of reentry vehicle heat shield

    Science.gov (United States)

    Russel, J. M., III

    1966-01-01

    Sensors measure surface erosion rate of ablating material in reentry vehicle heat shield. Each sensor, which is placed at precise depths in the heat shield is activated when the ablator surface erodes to the location of a sensing point. Sensor depth and activation time determine ablator surface erosion rate.

  16. Combining performance measures to investigate capacity changes in fisheries

    DEFF Research Database (Denmark)

    Thøgersen, Thomas Talund; Pascoe, Sean

    2014-01-01

    The Common Fisheries Policy (CFP) aims to achieve a balance between the European fleet capacity and the resources available. This can be realized either by temporarily reducing the fishing effort (i.e. capacity utilization) or quotas in the hope of increasing the resources available or reducing t...

  17. Energy Approach to Measure the Region’s Assimilative Capacity

    Directory of Open Access Journals (Sweden)

    Irina Stepanovna Belik

    2017-12-01

    Full Text Available One of the important problems of the environmental economics is the development of methodology for quantifying the assimilative capacity (AC of a territory. The article analyzes the existing approaches to determining and assessing the AC of a territory. We justify the advantages of using the energy approach. The authors’ method consists in using the maximum permissible energy load (MPEL for quantitative assessment of the AC of a territory. MPEL is a value that the ecological and economic system can withstand for a long time without changing its properties. We determine MPEL on the basis of data on the ability of various categories of land to absorb greenhouse gases (GHG, as well as the specific GHG emissions per ton of conventional fuel. Further, we compare the calculated value of MPEL in fuel equivalents with the actual consumption of fuel resources for the needs of the national economy. These values ratio can serve as a standard for measuring and balancing the environmental and economic system. The authors have validated the described method on the example of the Sverdlovsk region, which is characterized by a high level of man’s impact. Calculations show that the actual consumption of fossil fuels in the region exceeds MPEL. That indicates an imbalance in the ecological and economic system and may lead to further deterioration of the environmental quality in the region. The proposed methodological approach and calculations can be used when developing strategic planning documents for a territory, including its energy strategy

  18. Reactor Gamma Heat Measurements with Calorimeters and Thermoluminescence Dosimeters

    DEFF Research Database (Denmark)

    Haack, Karsten; Majborn, Benny

    1973-01-01

    Intercomparison measurements of reactor γ-ray heating were carried out with calorimeters and thermoluminescence dosimeters. Within the measurement uncertainties the two methods yield coincident results. In the actual measurement range thermoluminescence dosimeters are less accurate than calorimet......Intercomparison measurements of reactor γ-ray heating were carried out with calorimeters and thermoluminescence dosimeters. Within the measurement uncertainties the two methods yield coincident results. In the actual measurement range thermoluminescence dosimeters are less accurate than...... calorimeters, but possess advantages such as a small probe size and the possibility of making simultaneous measurements at many different positions. Hence, thermoluminescence dosimeters may constitute a valuable supplement to calorimeters for reactor γ-ray heating measurements....

  19. Heat capacity and density of solutions of calcium and cadmium nitrates in N-methylpyrrolidone at 298.15 K

    Science.gov (United States)

    Novikov, A. N.; Rassokhina, L. Yu.

    2013-08-01

    The heat capacity and density of solutions of calcium and cadmium nitrates in N-methylpyrrolidone (MP) at 298.15 K are studied by calorimetry and densimetry. The obtained data are discussed in relation to certain features of solvation and complex formation in solutions of these salts. The standard partial molar heat capacities and volumes (overline {C_{p^2 }^0 } and overline {V_2^0 }) of the electrolytes in MP are calculated. The standard heat capacities overline {C_{p^i }^0 } and volumes overline {V_i^0 } of Ca2+ and Cd2+ ions in MP at 298.15 K were determined, along with the contribution from specific interactions to the values of overline {C_{p^i }^0 } and overline {V_i^0 } of Cd2+ ions in MP solution.

  20. Heat capacity and density of solutions of lithium and sodium nitrates in N-methylpyrrolidone at 298.15 K

    Science.gov (United States)

    Novikov, A. N.

    2013-09-01

    The heat capacity and density of solutions of lithium and sodium nitrates in N-methylpyrrolidone (MP) at 298.15 K are studied by calorimetry and densimetry. The standard partial molar heat capacities and volumes ( C¯ p,2° and V¯ 2°) of LiNO3 and NaNO3 in MP are calculated. The standard heat capacities C¯ p,i ° and volumes V¯ i ° of Li+ and Na+ ions in MP at 298.15 K are determined on the basis of a proposed scale of ionic contributions of C¯ p,2° and V¯ 2° values. The obtained data are discussed in relation to certain features of solvation in solutions of the investigated salts.

  1. An automated flow calorimeter for the determination of liquid and vapor isobaric heat capacities: Test results for water and n -pentane

    Energy Technology Data Exchange (ETDEWEB)

    Sandarusi, J.A. (National Institute of Science and Technology, Thermophysics Division, Boulder, Colorado 80303 (United States)); Mulia, K.; Yesavage, V.F. (Colorado School of Mines, Chemical Engineering Department, Golden, Colorado 80401 (United States))

    1992-02-01

    An automated flow calorimeter has been developed for the measurement of highly accurate isobaric heat capacities and enthalpies of fluids at elevated temperatures and pressures. The instrument was successfully tested over the range 300--600 K and 0--12 MPa and is readily extensible to 700 K and 30 MPa. The flow calorimeter relied on an adiabatic design with a two-chambered cell design incorporating several concentric shells of active and passive shields designed to minimize heat losses, facilitate easy component replacement, and eliminate any external temperature regulation baths. A pair of miniature standard platinum resistance thermometers were built to determine the differential calorimeter temperatures. A precision metering pump eliminated the need for direct mass flow-rate determinations while a complete automation system supplied all of the required data acquisition, monitoring, and control (except for pressure) resources necessary to operate the calorimeter and make measurements from a single personal computer. Measurements of isobaric heat capacities were performed on water (liq.) and {ital n}-pentane (liq. and vap.) to test the new calorimeter. These experiments compared well with the published values, indicating an overall measurement precision of 0.1% and uncertainty in the range of 0.2%--0.3%. The total calorimeter heat leak was small affecting the experimental uncertainty as much as the combined mass flow-rate and calorimeter temperature difference errors.

  2. EXPERIENCE OF UTILIZATION OF CAPACITY BANKS AND SCHEMES OF FREQUENCY REGULATION IN MUNICIPAL CENTRALIZED HEATING SYSTEM OF CHISINAU

    Directory of Open Access Journals (Sweden)

    CHERNEI M

    2013-04-01

    Full Text Available The current paper provides a brief summary of the district heating system of the municipality Chisinau, including heat power sources, heat distribution network, production and consumption development over the past two decades and other data. Also, the priority investment projects realized by JSC "Termocom" are being presented. The company had implemented an automated monitoring system for the heat power production, transportation and distribution. For many years, the company used bellows pipes with polyurethane insulation, ball valves and plate heat exchangers. 14 out of 21 district heating boiler stations were upgraded 10 were completely automated having as a result no further need in full-time duty personnel there. The experience gained in the implementation of capacity banks and frequency inverters, summarizing the benefits and achieved results, is also presented in the current paper. It is to be underlined that in 2011 the company achieved decrease in electricity consumption by about 30% in comparison with 2005.

  3. Estimating local heat transfer coefficients from thin wall temperature measurements

    Science.gov (United States)

    Gazizov, I. M.; Davletshin, I. A.; Paereliy, A. A.

    2017-09-01

    An approach to experimental estimation of local heat transfer coefficient on a plane wall has been described. The approach is based on measurements of heat-transfer fluid and wall temperatures during some certain time of wall cooling. The wall was a thin plate, a printed circuit board, made of composite epoxy material covered with a copper layer. The temperature field can be considered uniform across the plate thickness when heat transfer is moderate and thermal resistance of the plate in transversal direction is low. This significantly simplifies the heat balance written for the wall sections that is used to estimate the heat transfer coefficient. The copper layer on the plate etched to form a single strip acted as resistance thermometers that measured the local temperature of the wall.

  4. Measurement of heat generation from simulated bituminized product

    Energy Technology Data Exchange (ETDEWEB)

    Kato, Yoshiyuki; Yoneya, Masayuki [TRP Safety Evaluation and Analysis team, Japan Nuclear Cycle Development Inst., Tokai, Ibaraki (Japan)

    1999-09-01

    The fire and explosion incident occurred at Bituminization Demonstration Facility of PNC Tokai Works on March 11, 1997. In order to ascertain the cause of incident, the investigation has been pushed forward. For the investigation, we prepared simulated bituminized product of measurement of heat generation in low temperature region less than 200degC. We used calvet Calorimeter MS80 for the heat generation measurement. Result of measurement, we were able to catch the feeble heat generation from bituminized product. The maximum calorific value that was able to detect it in isothermal measurement was approximately 1 mW/g in 160degC. It was approximately 2 mW/g in 200degC. And, as the another measurement, the measurement condition went heat rate by 0.01degC/minute, the highest temperature 190degC. As a result, the maximum generation of heat value that was able to detect it was approximately 0.5 mW/g. I changed simulated bituminized products and measured these. A difference of condition is salt particle size, salt content rate (45%, 60%), addition of the simulated precipitate. But there was not a difference in the generation of heat characteristic detected. (author)

  5. Application of Electric Capacity Measurements to Detecting Delamination in Blades of Helicopter’s Lifting and Auxiliary Rotors

    Directory of Open Access Journals (Sweden)

    Gębura Andrzej

    2017-06-01

    Full Text Available This paper represents a series of the authors’ publications concerning effects of atmospheric conditions on aircraft [5-6, 11]. Hazards connected with separation ( delamination of heating elements from blade’s spar , namely: increased susceptibility to ice formation as a result of change in aerodynamic profile, decreased deicing effectiveness, shortened life of heating elements , weakened strength of blade’s structure, are described. In order to monitor the above mentioned delamination process during its early phase, these authors proposed to measure systematically electric capacity between the heating element and blade’s spar by means of a technical method. The electric capacity measurements performed by these authors on blades both in laboratory and service conditions demonstrated their practical usefulness for assessing delamination extent as well as for identifying areas where heating element separation from spar occurred. The method in question is simple , cheap , fast and non-interferring (non-destructive as well as it does not require dismounting the blades off the helicopter. As proved in practice , it is especially useful in sea-rescue or military operational conditions. Special attention was paid to application of the method to composite blades where coming-off the heating element tape causes local overheating the blade structure , that impairs flexibility of composite’s layers and may lead even to local cracks which may trigger helicopter crash. These authors desire to apply the method as a standard unit of on-board diagnostic system in the future.

  6. Negative heat capacity in the critical region of nuclear fragmentation: an experimental evidence of the liquid-gas phase transition

    Science.gov (United States)

    D'Agostino, M.; Gulminelli, F.; Chomaz, P.; Bruno, M.; Cannata, F.; Bougault, R.; Gramegna, F.; Iori, I.; Le Neindre, N.; Margagliotti, G. V.; Moroni, A.; Vannini, G.

    2000-02-01

    An experimental indication of negative heat capacity in excited nuclear systems is inferred from the event by event study of energy fluctuations in Au quasi-projectile sources formed in Au+Au collisions at 35 A.MeV. Equilibrated events are selected and the excited source configuration is reconstructed through a calorimetric analysis of its de-excitation products. Fragment partitions show signs of a critical behavior at about 4.5 A.MeV excitation energy. Around this value the heat capacity shows a negative branch providing a direct evidence of a first order liquid gas phase transition.

  7. Measuring capacity building in communities: a review of the literature

    Directory of Open Access Journals (Sweden)

    Liberato Selma C

    2011-11-01

    Full Text Available Abstract Background Although communities have long been exhorted to make efforts to enhance their own health, such approaches have often floundered and resulted in little or no health benefits when the capacity of the community has not been adequately strengthened. Thus being able to assess the capacity building process is paramount in facilitating action in communities for social and health improvement. The current review aims to i identify all domains used in systematically documented frameworks developed by other authors to assess community capacity building; and ii to identify the dimensions and attributes of each of the domains as ascribed by these authors and reassemble them into a comprehensive compilation. Methods Relevant published articles were identified through systematic electronic searches of selected databases and the examination of the bibliographies of retrieved articles. Studies assessing capacity building or community development or community participation were selected and assessed for methodological quality, and quality in relation to the development and application of domains which were identified as constituents of community capacity building. Data extraction and analysis were undertaken using a realist synthesis approach. Results Eighteen articles met the criteria for this review. The various domains to assess community capacity building were identified and reassembled into nine comprehensive domains: "learning opportunities and skills development", "resource mobilization", "partnership/linkages/networking", "leadership", "participatory decision-making", "assets-based approach", "sense of community", "communication", and "development pathway". Six sub-domains were also identified: "shared vision and clear goals", "community needs assessment", "process and outcome monitoring", "sustainability", "commitment to action" and "dissemination". Conclusions The set of domains compiled in this review serve as a foundation for

  8. Measuring capacity building in communities: a review of the literature.

    Science.gov (United States)

    Liberato, Selma C; Brimblecombe, Julie; Ritchie, Jan; Ferguson, Megan; Coveney, John

    2011-11-09

    Although communities have long been exhorted to make efforts to enhance their own health, such approaches have often floundered and resulted in little or no health benefits when the capacity of the community has not been adequately strengthened. Thus being able to assess the capacity building process is paramount in facilitating action in communities for social and health improvement. The current review aims to i) identify all domains used in systematically documented frameworks developed by other authors to assess community capacity building; and ii) to identify the dimensions and attributes of each of the domains as ascribed by these authors and reassemble them into a comprehensive compilation. Relevant published articles were identified through systematic electronic searches of selected databases and the examination of the bibliographies of retrieved articles. Studies assessing capacity building or community development or community participation were selected and assessed for methodological quality, and quality in relation to the development and application of domains which were identified as constituents of community capacity building. Data extraction and analysis were undertaken using a realist synthesis approach. Eighteen articles met the criteria for this review. The various domains to assess community capacity building were identified and reassembled into nine comprehensive domains: "learning opportunities and skills development", "resource mobilization", "partnership/linkages/networking", "leadership", "participatory decision-making", "assets-based approach", "sense of community", "communication", and "development pathway". Six sub-domains were also identified: "shared vision and clear goals", "community needs assessment", "process and outcome monitoring", "sustainability", "commitment to action" and "dissemination". The set of domains compiled in this review serve as a foundation for community-based work by those in the field seeking to support and

  9. Modern perspectives on measuring and interpreting seafloor heat flux

    Science.gov (United States)

    Harris, Reid N.; Fisher, A.; Ruppel, C.; Martinez, F.

    2008-01-01

    There has been a resurgence of interest in marine heat flow in the past 10–15 years, coinciding with fundamental achievements in understanding the Earth's thermal state and quantifying the dynamics and impacts of material and energy fluxes within and between the lithosphere and hydrosphere. At the same time, technical capabilities have dwindled to the point that no U.S. academic institution currently operates a seagoing heat flow capacity.In September 2007, a workshop was convened in Salt Lake City with sponsorship from the U.S. National Science Foundation (NSF) and participation by scientists and engineers from North America, Europe, and Asia. The primary goals of the workshop were to (1) assess high-priority scientific and technical needs and (2) to evaluate options for developing and maintaining essential capabilities in marine heat flow for the U.S. scientific community.

  10. Heat Transfer Coefficient Measurement for Downward Facing Flow Boiling Heat Transfer

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Jun Yeong; Jeong, Yong Hoon [KAIST, Daejeon (Korea, Republic of)

    2016-05-15

    To evaluate heat transfer capability of the ERVC, estimating heat transfer coefficient (HTC) is important. In this study, the HTCs were experimentally measured, and large break loss of coolant accident (LLOCA) was used as basic accident. At the lower head outer wall, heat transfer phenomenon was downward facing flow boiling heat transfer. Because, natural circulation occurred. Hence, to simulate the flow boiling, water loop was designed. The reactor vessel lower head was simulated as 2-D slice main heater. To simulate the heat transfer characteristics of material and geometry, the main heater was made of SA508 consisting the reactor vessel, and its radius curvature was 2.5 m. The main heater outer surface (facing to air) temperature was measured by infrared (IR) camera, and the inner surface (facing to working fluid) temperature was calculated by solving conduction equation of main heater. The main heater heat flux was under CHF value of previous research. The results of 60 .deg. and 90 .deg. were used as representative angular location data. LLOCA was used as basic accident. Through this experiment, the HTC data was produced for SA508 heat transfer surface material and 2.5 m of radius curvature. The HTCs result shown different trend at each angular location. The HTCs commonly increased with heat flux increment, but the trends were different for angular location.

  11. 1.9 K Heat Inleak and Resistive Heating Measurements on LHC Cryomagnets

    CERN Document Server

    Ferlin, G; Tavian, L; Wagner, U

    2010-01-01

    The superconducting magnets of the Large Hadron Collider (LHC) distributed over eight sectors of 3.3-km long are cooled at 1.9 K in pressurized superfluid helium. During the commissioning campaign of the sectors in 2008, cold standby periods at nominal operating temperature have allowed to measure the overall static heat inleaks reaching the magnet cold masses at 1.9 K by enthalpy balance in steady-state operation. In addition, during electrical powering of the different magnet circuits, helium II calorimetry based on precision thermometry has been implemented to assess with an accuracy of 100 mW/m the additional heat loads due to resistive heating and to detect possible abnormal heat dissipation during powering. This paper describes the method applied to perform these measurements, compares the results with the expected specified values and discusses the impact of the measured values on cryo-plant tuning and operational margins.

  12. Avian thermoregulation in the heat: evaporative cooling capacity in an archetypal desert specialist, Burchell's sandgrouse (Pterocles burchelli).

    Science.gov (United States)

    McKechnie, Andrew E; Smit, Ben; Whitfield, Maxine C; Noakes, Matthew J; Talbot, William A; Garcia, Mateo; Gerson, Alexander R; Wolf, Blair O

    2016-07-15

    Sandgrouse (Pterocliformes) are quintessential examples of avian adaptation to desert environments, but relatively little is known about the limits to their heat tolerance and evaporative cooling capacity. We predicted that evaporative cooling in Burchell's sandgrouse (Pterocles burchelli) is highly efficient and provides the basis for tolerance of very high air temperature (Ta). We measured body temperature (Tb), resting metabolic rate (RMR) and evaporative water loss (EWL) at Ta between 25°C and ∼58°C in birds exposed to successive increments in Ta Normothermic Tb averaged 39.0°C, lower than typical avian values. At Ta>34.5°C, Tb increased linearly to a maximum of 43.6°C at Ta=56°C. The upper critical limit of thermoneutrality (Tuc) was Ta=43.8°C, closely coinciding with the onset of panting and gular flutter. Above the Tuc, RMR increased 2.5-fold to 2.89 W at Ta=56°C, a fractional increase far exceeding that of many other species under comparable conditions. Rates of EWL increased rapidly at Ta>42.9°C to 7.84±0.90 g h(-1) at Ta=56°C, an 11-fold increase above minimal levels. Maximum evaporative cooling efficiency (ratio of evaporative heat loss to metabolic heat production) was 2.03, but could be as high as 2.70 if our assumption that the birds were metabolising lipids is incorrect. Thermoregulation at very high Ta in P. burchelli was characterised by large increases in RMR and EWL, and is much less efficient than in taxa such as columbids and caprimulgids. © 2016. Published by The Company of Biologists Ltd.

  13. Measuring influenza laboratory capacity: use of a tool to measure improvements.

    Science.gov (United States)

    Kennedy, Pam; Aden, Tricia; Cheng, Po Yung; Moen, Ann

    2017-06-15

    To collect information, identify training needs, and assist with influenza capacity building voluntary laboratory capacity assessments were conducted using a standardized tool in CDC cooperative agreement countries. To understand the usefulness of comparing results from repeat assessments and to determine if targeted training supported improvements, this paper details comparison of assessment results of conducting 17 repeat laboratory assessments between 2009 and 2013. Laboratory assessments were conducted by SMEs in 17 laboratories (16 countries). We reviewed the quantitative assessment results of the laboratories that conducted both an initial and follow up assessment between 2009 to 2013 using repeated measures of Anova, (Mixed procedure of SAS (9.3)). Additionally, we compared the overall summary scores and the assessor recommendations from the two assessments. We were able to document a statistically significant improvement between the first and second assessments both on an aggregate as well as individual indicator score. Within the international capacity tool three of the eight categories recorded statistically significant improvement (equipment, management, and QA/QC), while the other tool categories (molecular, NIC, specimen, safety and virology) showed improvement in scores although not statistically significant. We found that using a standardized tool and quantitative framework is useful for documenting capacity and performance improvement in identified areas over time. The use of the tool and standard reports with assessor recommendations assisted laboratories with establishing, maintaining, and improving influenza laboratory practices. On-going assessments and the consistent application of the analytic framework over time will continue to aid in building a measurement knowledge base for laboratory capacity.

  14. Graded Reflectivity Mirror for the Solid State Heat Capacity Laser Final Report CRADA No. TC-2085-04

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, R. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Davis, J. A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2017-09-27

    This was a collaborative effort between The Regents of the University of California, Lawrence Livermore National Laboratory (LLNL) and the Boeing Company, to develop a Graded Reflectivity Mirror (GRM) to achieve improved near field fill and higher brightness in the far field output of LLNL’s Solid State Heat Capacity Laser (SSHCL).

  15. Sporulation environment of emetic toxin-producing Bacillus cereus strains determines spore size, heat resistance and germination capacity

    NARCIS (Netherlands)

    Voort, van der M.; Abee, T.

    2013-01-01

    Aim Heat resistance, germination and outgrowth capacity of Bacillus cereus spores in processed foods are major factors in causing the emetic type of gastrointestinal disease. In this study, we aim to identify the impact of different sporulation conditions on spore properties of emetic

  16. Heat transfer measurements with a four-core optical fiber

    Science.gov (United States)

    Güvenç, Sema; Inci, Mehmet Naci

    2017-05-01

    A four-core optical fiber is used to investigate one-dimensional heat transfer measurements. Heat pulses from a Nd:YAG laser of 600 ms duration with a repetition rate of the order of 10 s are delivered onto one of the fiber cores. This results in an optical path length difference between the guiding cores due to the change in the refractive index and physical length of the targeted fiber core. As a result of this process, a phase shift of 1.30 rad is measured with a digital camera for 140 mW pulses in reflection scheme. The heat diffusion length in the selected fiber core is determined to be 2.8 mm, which contains 33.2 kJ/m2s heat, causing a temperature rise of 4.30 K.

  17. Measurement and investigation into air source heat pump exergy

    Science.gov (United States)

    Cho, Hung-Pin; Hsu, Ching-Wei; Jwo, Ching-Song; Tsai, Meng-Ying; Chen, Sih-Li

    2011-12-01

    This study applies the second law of thermodynamics to analyze the irreversibility of air source heat pump systems. By using both T type thermocouple wires to measure the inlet and outlet temperatures of key components in the system and using pressure transmitters to measure the high and low pressure of the experiment systems, we collect data and use two control volume(CV) models to calculate the generative volume and irreversibility of entropy for each system component. According to the experiment results for both CV models (the CV of the refrigerant section and the CV of the whole control), the heat exchanger is found to have the largest irreversibility. The irreversibility error of the condenser is 4.6% and the irreversibility error of the evaporator is up to 21%. By applying the results of this study it is possible to improve the function of air source heat pump systems through improving the heat exchanger, achieving both cost and energy savings.

  18. Determination of heat capacity of ionic liquid based nanofluids using group method of data handling technique

    Science.gov (United States)

    Sadi, Maryam

    2017-07-01

    In this study a group method of data handling model has been successfully developed to predict heat capacity of ionic liquid based nanofluids by considering reduced temperature, acentric factor and molecular weight of ionic liquids, and nanoparticle concentration as input parameters. In order to accomplish modeling, 528 experimental data points extracted from the literature have been divided into training and testing subsets. The training set has been used to predict model coefficients and the testing set has been applied for model validation. The ability and accuracy of developed model, has been evaluated by comparison of model predictions with experimental values using different statistical parameters such as coefficient of determination, mean square error and mean absolute percentage error. The mean absolute percentage error of developed model for training and testing sets are 1.38% and 1.66%, respectively, which indicate excellent agreement between model predictions and experimental data. Also, the results estimated by the developed GMDH model exhibit a higher accuracy when compared to the available theoretical correlations.

  19. A role for haemolymph oxygen capacity in heat tolerance of eurythermal crabs.

    Directory of Open Access Journals (Sweden)

    Folco eGiomi

    2013-05-01

    Full Text Available Heat tolerance in aquatic ectotherms is constrained by a mismatch, occurring at high temperatures, between oxygen delivery and demand which compromises the maintenance of aerobic scope. The present study analyses how the wide thermal tolerance range of an eurythermal model species, the green crab Carcinus maenas is supported and limited by its ability to sustain efficient oxygen transport to tissues. Similar to other eurytherms, C. maenas sustains naturally occurring acute warming events through the integrated response of circulatory and respiratory systems. The response of C. maenas to warming is characterized by two phases. During initial warming, oxygen consumption and heart rate increase while stroke volume and haemolymph oxygen partial pressures decrease. During further warming, dissolved oxygen levels in the venous compartment decrease below the threshold of full haemocyanin oxygen saturation. The progressive release of haemocyanin bound oxygen with further warming follows an exponential pattern, thereby saving energy in oxygen transport and causing an associated leveling off of metabolic rate. According to the concept of oxygen and capacity limited thermal tolerance, this indicates that the thermal tolerance window is widened by the increasing contribution of haemocyanin oxygen transport and associated energy savings in cardiocirculation. Haemocyanin bound oxygen sustains cardiac performance to cover the temperature range experienced by C. maenas in the field. To our knowledge this is the first study providing evidence of a relationship between thermal tolerance and blood (haemolymph oxygen transport in eurythermal invertebrates.

  20. The Stone-Wales transformation: from fullerenes to graphite, from radiation damage to heat capacity.

    Science.gov (United States)

    Heggie, M I; Haffenden, G L; Latham, C D; Trevethan, T

    2016-09-13

    The Stone-Wales (SW) transformation, or carbon-bond rotation, has been fundamental to understanding fullerene growth and stability, and ab initio calculations show it to be a high-energy process. The nature and topology of the fullerene energy landscape shows how the Ih-C60 must be the final product, if SW transformations are fast enough, and various mechanisms for their catalysis have been proposed. We review SW transformations in fullerenes and then discuss the analogous transformation in graphite, where they form the Dienes defect, originally posited to be a transition state in the direct exchange of a bonded atom pair. On the basis of density functional theory calculations in the local density approximation, we propose that non-equilibrium concentrations of the Dienes defect arising from displacing radiation are rapidly healed by point defects and that equilibrium concentrations of Dienes defects are responsible for the divergent ultra-high-temperature heat capacity of graphite.This article is part of the themed issue 'Fullerenes: past, present and future, celebrating the 30th anniversary of Buckminster Fullerene'. © 2016 The Author(s).

  1. Low temperature resonances in the fermion heat capacity of finite systems

    Energy Technology Data Exchange (ETDEWEB)

    Kuzmenko, N K [V.G. Khlopin Radium Institute, 194021 St.-Petersburg (Russian Federation); Mikhajlov, V M [Institute of Physics St.-Petersburg State University 198904 (Russian Federation)], E-mail: kuzmenko@NK9433.spb.edu

    2009-02-01

    Temperature variations of the heat capacity (C) are studied in a low temperature regime T < {epsilon}{sub f}/N ({epsilon}{sub f} is the Fermi energy) for 2D-, and 3D-systems with N{approx} 10{sup 2} to 10{sup 4} treated as a canonical ensemble of N-noninteracting fermions. The analysis of C is performed by introducing a function {rho}({epsilon}), the spectral distribution of C that gives the contribution of each single-particle state to C. The function {rho}({epsilon}) has two peaks divided by the energy interval {delta} {epsilon} {approx} (2 to 5) T. If at some temperature T{sub res} there takes place a resonance i.e. the positions of these peaks coincide with energies of two levels nearest to {epsilon}{sub F} then C vs T shows a local maximum i.e. T{sub res} is determined by single-particle level spacings near the Fermi level.

  2. Urban and regional heat island adaptation measures in the Netherlands

    Directory of Open Access Journals (Sweden)

    Leyre Echevarria Icaza

    2017-11-01

    the formation of urban heat in the province. The average day LST of provincial parks in South Holland varies depending on the land use. The analysis of the average night LST varies depending of the land use of the patches. The following surfaces are arranged from the lowest to the highest temperatures: water surfaces, forests, cropland, and greenhouse areas. For each of these land uses, NDVI, imperviousness and landscape shape index (LSI shape index influence the thermal behaviour of the patches differently. NDVI is inversely correlated to day LST for all categories, imperviousness is correlated to day LST for all areas which do not comprise a significant presence of greenhouses (grassland and built patches and inversely correlated to LST for areas with a high presence of greenhouses (cropland and warehouses. Greenhouse surfaces have highly reflective roofs, which contribute to the reduction of day LST. Finally, landscape shape index varies depending on the nature of the surrounding patches, especially for small patches (built areas, forests and greenhouse areas. When the patches analysed are surrounded by warmer land uses, slender and scattered patches are warmer, more compact and large ones are cooler. In turn, when they are surrounded by cooler patches it is the opposite: slenderer and scattered patches are cooler and more compact and larger ones are warmer. In Midden-Delfland (1 of the 6 South Holland provincial parks, most of the hotspots surrounding the park are adjacent to grassland patches. The measure to increase the cooling capacity of those patches would consist in a change of land use and/or an increase of NDVI of the existing grassland patches. Conclusions Satellite imagery can be used not only to analyse the heat island phenomenom in Dutch neighbourhoods, cities and regions (identify neighbourhoods with highest surface temperature, identify impact of city size and morphology in surface temperature, calcuate average surface temperature for different land

  3. Simultaneous measurement of aerodynamic and heat transfer data ...

    Indian Academy of Sciences (India)

    An aluminum model incorporating a three-component accelerometer-based balance system for measuring the aerodynamic forces and an array of platinum thin-film gauges deposited on thermally insulating backing material flush mounted on the model surface is used for convective surface heat transfer measurement in the ...

  4. Measurements of convective and radiative heating in wildland fires

    Science.gov (United States)

    David Frankman; Brent W. Webb; Bret W. Butler; Daniel Jimenez; Jason M. Forthofer; Paul Sopko; Kyle S. Shannon; J. Kevin Hiers; Roger D. Ottmar

    2012-01-01

    Time-resolved irradiance and convective heating and cooling of fast-response thermopile sensors were measured in 13 natural and prescribed wildland fires under a variety of fuel and ambient conditions. It was shown that a sensor exposed to the fire environment was subject to rapid fluctuations of convective transfer whereas irradiance measured by a windowed sensor was...

  5. Understanding and Measuring Evaluation Capacity: A Model and Instrument Validation Study

    Science.gov (United States)

    Taylor-Ritzler, Tina; Suarez-Balcazar, Yolanda; Garcia-Iriarte, Edurne; Henry, David B.; Balcazar, Fabricio E.

    2013-01-01

    This study describes the development and validation of the Evaluation Capacity Assessment Instrument (ECAI), a measure designed to assess evaluation capacity among staff of nonprofit organizations that is based on a synthesis model of evaluation capacity. One hundred and sixty-nine staff of nonprofit organizations completed the ECAI. The 68-item…

  6. CO2 Capacity Sorbent Analysis Using Volumetric Measurement Approach

    Science.gov (United States)

    Huang, Roger; Richardson, Tra-My Justine; Belancik, Grace; Jan, Darrell; Knox, James; Cmarik, Gregory E.; Ebner, Armin; Ritter, James

    2017-01-01

    In support of air revitalization system sorbent selection for future space missions, Ames Research Center (ARC) has performed CO2 capacity tests on various solid sorbents to complement structural strength tests conducted at Marshall Space Flight Center (MSFC). The materials of interest are: Grace Davison Grade 544 13X, Honeywell UOP APG III, LiLSX VSA-10, BASF 13X, and Grace Davison Grade 522 5A. CO2 capacity was for all sorbent materials using a Micromeritics ASAP 2020 Physisorption Volumetric Analysis machine to produce 0 C, 10 C, 25 C, 50 C, and 75 C isotherms. These data are to be used for modeling data and to provide a basis for continued sorbent research. The volumetric analysis method proved to be effective in generating consistent and repeatable data for the 13X sorbents, but the method needs to be refined to tailor to different sorbents.

  7. Heating capacity of rebound shortwave diathermy and moist hot packs at superficial depths.

    Science.gov (United States)

    Hawkes, Amanda R; Draper, David O; Johnson, A Wayne; Diede, Mike T; Rigby, Justin H

    2013-01-01

    The effectiveness of a new continuous diathermy unit, ReBound, as a heating modality is unknown. To compare the effects of ReBound diathermy with silicate-gel moist hot packs on tissue temperature in the human triceps surae muscle. Crossover study. University research laboratory. A total of 12 healthy, college-aged volunteers (4 men, 8 women; age = 22.2 ± 2.25 years, calf subcutaneous fat thickness = 7.2 ± 1.9 mm). On 2 different days, 1 of 2 modalities (ReBound diathermy, silicate-gel moist hot pack) was applied to the triceps surae muscle of each participant for 30 minutes. After 30 minutes, the modality was removed, and temperature decay was recorded for 20 minutes. Medial triceps surae intramuscular tissue temperature at a depth of 1 cm was measured using an implantable thermocouple inserted horizontally into the muscle. Measurements were taken every 5 minutes during the 30-minute treatment and every minute during the 20-minute temperature decay, for a total of 50 minutes. Treatment was analyzed through a 2 × 7 mixed-model analysis of variance with repeated measures. Temperature decay was analyzed through a 2 × 21 mixed-model analysis of variance with repeated measures. During the 30-minute application, tissue temperatures at a depth of 1 cm increased more with the ReBound diathermy than with the moist hot pack (F6,66 = 7.14, P diathermy and moist hot packs increased tissue temperatures 3.69°C ± 1.50°C and 2.82°C ± 0.90°C, respectively, from baseline. Throughout the temperature decay, ReBound diathermy produced a greater rate of heat dissipation than the moist hot pack (F20,222 = 4.42, P diathermy increased tissue temperature to moderate levels, which were greater than the levels reached with moist hot packs.

  8. New free radicals to measure antiradical capacity: a theoretical study.

    Science.gov (United States)

    León-Carmona, Jorge Rafael; Martínez, Ana; Galano, Annia

    2014-08-28

    A new family of free radicals, that are soluble in water and stable at all pH values, were recently synthesized and used to assess the antiradical capacity of several polyphenols. In the present work, density functional calculations were used to investigate the single electron transfer reactions between these new free radicals and polyphenols in aqueous solution. The quantification of the antiradical capacity is a challenge, particularly for polyphenols, since they become unstable under experimental conditions. It was found that the electron transfer from polyphenols to the newly developed free radicals can be used to assess the efficiency of this kind of compound for preventing oxidative stress. Since one of the free radicals can be deprotonated under experimental conditions, this newly synthesized radical can help distinguish more clearly between different antiradical compounds with similar antioxidant capacity by modifying the pH in the experiments. The results reported here are in good agreement with the available experimental data and allowed making recommendations about possible experimental conditions in the design of antioxidant assays using the investigated radicals.

  9. How to measure working memory capacity in the change detection paradigm

    NARCIS (Netherlands)

    Rouder, Jeffrey N.; Morey, Richard D.; Morey, Candice C.; Cowan, Nelson

    Although the measurement of working memory capacity is crucial to understanding working memory and its interaction with other cognitive faculties, there are inconsistencies in the literature on how to measure capacity. We address the measurement in the change detection paradigm, popularized by Luck

  10. Application of customized absorption heat pumps with heating capacities above 500 kW: Project: VIVO, Warngau (near Munich)

    OpenAIRE

    Zachmeier, Peter; Radspieler, Michael; Schweigler, Christian

    2013-01-01

    Part of: Thermally driven heat pumps for heating and cooling. – Ed.: Annett Kühn – Berlin: Universitätsverlag der TU Berlin, 2013 ISBN 978-3-7983-2686-6 (print) ISBN 978-3-7983-2596-8 (online) urn:nbn:de:kobv:83-opus4-39458 [http://nbn-resolving.de/urn:nbn:de:kobv:83-opus4-39458] In 2005 a gas fired single effect absorption heat pump was installed at the area of VIVO GmbH, who runs a local civic waste collection point. Besides other recyclable materials, biodegra...

  11. Thermodynamics of aqueous uranyl ion: Apparent and partial molar heat capacities and volumes of aqueous uranyl perchlorate from 10 to 55°C

    Science.gov (United States)

    Hovey, Jamey K.; Nguyen-Trung, Chinh; Tremaine, Peter R.

    1989-07-01

    Apparent molar heat capacities and volumes of aqueous solutions containing UO2(ClO4)2 in dilute (≈0.06 molal) HClO4 have been determined from 10 to 55°C. These results have been analyzed using Young's rule to obtain apparent molar volumes and heat capacities for the solute UO2(ClO42). The temperature dependences of the conventional standard-state heat capacity and volume functions for UO22+ (aq) are well represented by the following equations: V¯°/cm(30 mo1P-1) -80.94 + 0.6091 T - 0.001063T2 andC¯/p0/(J K-1 mol-1) = 350.5 - 0.8722T - 5308/T -90) that are valid from 10 to 55°C. These results differ substantially from results of earlier measurements employing different uranyl salts. These differences are likely due to the presence of ion-paired or hydrolyzed U (VI) species in the earlier studies.

  12. Thermophysical Properties of Cold- and Vacuum Plasma-Sprayed Cu-Cr-X Alloys, NiAl and NiCrAlY Coatings II: Specific Heat Capacity

    Science.gov (United States)

    Raj, S. V.

    2017-10-01

    Part I of the paper discussed the temperature dependencies of the electrical resistivities, thermal conductivities, thermal diffusivities and total hemispherical emissivities of several vacuum plasma-sprayed (VPS) and cold-sprayed (CS) copper alloy monolithic coatings, VPS NiAl, VPS NiCrAlY, extruded GRCop-84 and as-cast Cu-17(wt.%)Cr-5%Al. Part II discusses the temperature dependencies of the constant-pressure specific heat capacities, C P, of these coatings. The data were empirically regression-fitted with the equation: \\varvec{C}_{P} = AT^{4} + BT^{3} + CT^{2} + DT + \\varvec{E} where T is the absolute temperature and A, B, C, D and E are regression constants. The temperature dependencies of the molar enthalpy, molar entropy and Gibbs molar free energy determined from experimental values of molar specific heat capacity are reported. Calculated values of C P using the Neumann-Kopp (NK) rule were in poor agreement with experimental data. Instead, a modification of the NK rule was found to predict values closer to the experimental data with an absolute deviation less than 6.5%. The specific molar heat capacities for all the alloys did not agree with the Dulong-Petit law, and C P > 3R, where R is the universal gas constant, were measured for all the alloys except NiAl for which C P < 3R at all temperatures.

  13. Thermophysical Properties of Cold and Vacuum Plasma Sprayed Cu-Cr-X Alloys, NiAl and NiCrAlY Coatings. Part 2; Specific Heat Capacity

    Science.gov (United States)

    Raj, S. V.

    2017-01-01

    Part I of the paper discussed the temperature dependencies of the electrical resistivities, thermal conductivities, thermal diffusivities and total hemispherical emissivities of several vacuum plasma sprayed (VPS) and cold sprayed copper alloy monolithic coatings, VPS NiAl, VPS NiCrAlY, extruded GRCop-84 and as-cast Cu-17(wt.%)Cr-5%Al. Part II discusses the temperature dependencies of the constant pressure specific heat capacities, CP, of these coatings. The data were empirically were regression-fitted with the equation: CP = AT4 + BT3 + CT2 + DT +E where T is the absolute temperature and A, B, C, D and E are regression constants. The temperature dependencies of the molar enthalpy, molar entropy and Gibbs molar free energy determined from experimental values of molar specific heat capacity are reported. Calculated values of CP using the Neumann-Kopp (NK) rule were in poor agreement with experimental data. Instead, a modification of the Neumann-Kopp rule was found to predict values closer to the experimental data with an absolute deviation less than 6.5%. The specific molar heat capacities for all the alloys did not agree with the Dulong-Petit law, and CP is greater than 3R, where R is the universal gas constant, were measured for all the alloys except NiAl for which CP is less than 3R at all temperatures.

  14. Low temperature heat capacities and standard molar enthalpy of formation of sodium benzoate C{sub 6}H{sub 5}COONa (s)

    Energy Technology Data Exchange (ETDEWEB)

    Kong, Yu-Xia [College of Chemistry and Chemical Engineering, Liaocheng University, Liaocheng 252059, Shandong Province (China); Di, You-Ying, E-mail: yydi@lcu.edu.cn [College of Chemistry and Chemical Engineering, Liaocheng University, Liaocheng 252059, Shandong Province (China); Qi, Yu-Dong; Yang, Wei-Wei [College of Chemistry and Chemical Engineering, Liaocheng University, Liaocheng 252059, Shandong Province (China); Tan, Zhi-Cheng [Thermochemistry Laboratory, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023 (China)

    2009-05-05

    Sodium benzoate was synthesized by the method of liquid phase synthesis, in which benzoic acid and anhydrous sodium carbonate were chosen as the reactants. The structure and composition of the compound were characterized by FTIR, chemical analysis, elemental analysis and X-ray powder diffraction techniques. Low temperature heat capacities of the compound were measured by a precision automated adiabatic calorimeter over the temperature range from 78 to 400 K. A polynomial equation of the heat capacities as a function of the temperature was fitted by least square method. The smoothed heat capacities and the thermodynamic functions of the compound relative to 298.15 K have been calculated based on the equation. In accordance with Hess law, the standard molar enthalpy of formation of the title compound C{sub 6}H{sub 5}COONa (s) was determined to be {Delta}{sub f}H{sup o}{sub m}[C{sub 6}H{sub 5}COONa,s]=-(642.56{+-}0.64)kJmol{sup -1} by using an isoperibol solution-reaction calorimeter.

  15. Thermophysical Properties of Cold- and Vacuum Plasma-Sprayed Cu-Cr-X Alloys, NiAl and NiCrAlY Coatings II: Specific Heat Capacity

    Science.gov (United States)

    Raj, S. V.

    2017-11-01

    Part I of the paper discussed the temperature dependencies of the electrical resistivities, thermal conductivities, thermal diffusivities and total hemispherical emissivities of several vacuum plasma-sprayed (VPS) and cold-sprayed (CS) copper alloy monolithic coatings, VPS NiAl, VPS NiCrAlY, extruded GRCop-84 and as-cast Cu-17(wt.%)Cr-5%Al. Part II discusses the temperature dependencies of the constant-pressure specific heat capacities, C P, of these coatings. The data were empirically regression-fitted with the equation: \\varvec{C}_{P} = {AT}^{4} + {BT}^{3} + {CT}^{2} + DT + \\varvec{E}where T is the absolute temperature and A, B, C, D and E are regression constants. The temperature dependencies of the molar enthalpy, molar entropy and Gibbs molar free energy determined from experimental values of molar specific heat capacity are reported. Calculated values of C P using the Neumann-Kopp (NK) rule were in poor agreement with experimental data. Instead, a modification of the NK rule was found to predict values closer to the experimental data with an absolute deviation less than 6.5%. The specific molar heat capacities for all the alloys did not agree with the Dulong-Petit law, and C P > 3 R, where R is the universal gas constant, were measured for all the alloys except NiAl for which C P < 3 R at all temperatures.

  16. Measurement of heat pump processes induced by laser radiation

    Science.gov (United States)

    Garbuny, M.; Henningsen, T.

    1983-01-01

    A series of experiments was performed in which a suitably tuned CO2 laser, frequency doubled by a Tl3AsSe37 crystal, was brought into resonance with a P-line or two R-lines in the fundamental vibration spectrum of CO. Cooling or heating produced by absorption in CO was measured in a gas-thermometer arrangement. P-line cooling and R-line heating could be demonstrated, measured, and compared. The experiments were continued with CO mixed with N2 added in partial pressures from 9 to 200 Torr. It was found that an efficient collisional resonance energy transfer from CO to N2 existed which increased the cooling effects by one to two orders of magnitude over those in pure CO. Temperature reductions in the order of tens of degrees Kelvin were obtained by a single pulse in the core of the irradiated volume. These measurements followed predicted values rather closely, and it is expected that increase of pulse energies and durations will enhance the heat pump effects. The experiments confirm the feasibility of quasi-isentropic engines which convert laser power into work without the need for heat rejection. Of more immediate potential interest is the possibility of remotely powered heat pumps for cryogenic use, such applications are discussed to the extent possible at the present stage.

  17. In vitro measurements and interpretation of total antioxidant capacity.

    Science.gov (United States)

    Fraga, Cesar G; Oteiza, Patricia I; Galleano, Monica

    2014-02-01

    One of the strategies most commonly used to assess a free radical-antioxidant balance in chemical and biological systems is the determination of the total antioxidant capacity (TAC). A large amount of research has been published using TAC. However, it remains unclear which is the significance of these investigations for understanding the biological importance of free radical reactions. This review discusses the relevance and limitations of TAC for the assessment of the antioxidant activities present in food and food derivatives, and in body tissues and fluids. TAC determinations are simple, inexpensive, and able to evaluate the capacity of known and unknown antioxidants and their additive, synergistic and/or antagonistic actions, in chemical and biological systems. However, different TAC assays correlate poorly with each other, since each TAC assay is sensitive to a particular combination of compounds, but exclude many others. The TAC values for foods cannot be translated to the in vivo (human) antioxidant defenses, and furthermore, to health effects provided by that food. Up to date, conclusions that can be drawn from the extensive amount of research done using TAC of foods or populations should not be considered when used for making decisions affecting population health. This article is part of a Special Issue entitled Current methods to study reactive oxygen species - pros and cons and biophysics of membrane proteins. Guest Editor: Christine Winterbourn. © 2013.

  18. Measure Guideline: Combined Space and Water Heating Installation and Optimization

    Energy Technology Data Exchange (ETDEWEB)

    Schoenbauer, B. [NorthernSTAR Building America Partnership, St. Paul, MN (United States); Bohac, D. [NorthernSTAR Building America Partnership, St. Paul, MN (United States); Huelman, P. [NorthernSTAR Building America Partnership, St. Paul, MN (United States)

    2017-03-01

    Combined space and water heater (combi or combo) systems are defined by their dual functionality. Combi systems provide both space heating and water heating capabilities with a single heat source. This guideline will focus on the installation and operation of residential systems with forced air heating and domestic hot water (DHW) functionality. Past NorthernSTAR research has used a combi system to replace a natural gas forced air distribution system furnace and tank type water heater (Schoenbauer et al. 2012; Schoenbauer, Bohac, and McAlpine 2014). The combi systems consisted of a water heater or boiler heating plant teamed with a hydronic air handler that included an air handler, water coil, and water pump to circulate water between the heating plant and coil. The combi water heater or boiler had a separate circuit for DHW. Past projects focused on laboratory testing, field characterization, and control optimization of combi systems. Laboratory testing was done to fully characterize and test combi system components; field testing was completed to characterize the installed performance of combi systems; and control methodologies were analyzed to understand the potential of controls to simplify installation and design and to improve system efficiency and occupant comfort. This past work was relied upon on to create this measure guideline.

  19. Measure Guideline: Combined Space and Water Heating Installation and Optimization

    Energy Technology Data Exchange (ETDEWEB)

    Schoenbauer, B. [Univ. of Minnesota, St. Paul, MN (United States). NorthernSTAR Building America Partnership; Bohac, D. [Univ. of Minnesota, St. Paul, MN (United States). NorthernSTAR Building America Partnership; Huelman, P. [Univ. of Minnesota, St. Paul, MN (United States). NorthernSTAR Building America Partnership

    2017-03-03

    Combined space and water heater (combi or combo) systems are defined by their dual functionality. Combi systems provide both space heating and water heating capabilities with a single heat source. This guideline will focus on the installation and operation of residential systems with forced air heating and domestic hot water (DHW) functionality. Past NorthernSTAR research has used a combi system to replace a natural gas forced air distribution system furnace and tank type water heater (Schoenbauer et al. 2012; Schoenbauer, Bohac, and McAlpine 2014). The combi systems consisted of a water heater or boiler heating plant teamed with a hydronic air handler that included an air handler, water coil, and water pump to circulate water between the heating plant and coil. The combi water heater or boiler had a separate circuit for DHW. Past projects focused on laboratory testing, field characterization, and control optimization of combi systems. Laboratory testing was done to fully characterize and test combi system components; field testing was completed to characterize the installed performance of combi systems; and control methodologies were analyzed to understand the potential of controls to simplify installation and design and to improve system efficiency and occupant comfort. This past work was relied upon on to create this measure guideline.

  20. Heat transport measurements in turbulent rotating Rayleigh-Benard convection

    Energy Technology Data Exchange (ETDEWEB)

    Ecke, Robert E [Los Alamos National Laboratory; Liu, Yuanming [Los Alamos National Laboratory

    2008-01-01

    We present experimental heat transport measurements of turbulent Rayleigh-Benard convection with rotation about a vertical axis. The fluid, water with Prandtl number ({sigma}) about 6, was confined in a cell which had a square cross section of 7.3 cm x 7.3 cm and a height of 9.4 cm. Heat transport was measured for Rayleigh numbers 2 x 10{sup 5} < Ra < 5 x 10{sup 8} and Taylor numbers 0 < Ta < 5 x 10{sup 9}. We show the variation of normalized heat transport, the Nusselt number, at fixed dimensional rotation rate {Omega}{sub D}, at fixed Ra varying Ta, at fixed Ta varying Ra, and at fixed Rossby number Ro. The scaling of heat transport in the range 10{sup 7} to about 10{sup 9} is roughly 0.29 with a Ro dependent coefficient or equivalently is also well fit by a combination of power laws of the form a Ra{sup 1/5} + b Ra{sup 1/3} . The range of Ra is not sufficient to differentiate single power law or combined power law scaling. The overall impact of rotation on heat transport in turbulent convection is assessed.

  1. Calibration of Heat Stress Monitor and its Measurement Uncertainty

    Science.gov (United States)

    Ekici, Can

    2017-07-01

    Wet-bulb globe temperature (WBGT) equation is a heat stress index that gives information for the workers in the industrial areas. WBGT equation is described in ISO Standard 7243 (ISO 7243 in Hot environments—estimation of the heat stress on working man, based on the WBGT index, ISO, Geneva, 1982). WBGT is the result of the combined quantitative effects of the natural wet-bulb temperature, dry-bulb temperature, and air temperature. WBGT is a calculated parameter. WBGT uses input estimates, and heat stress monitor measures these quantities. In this study, the calibration method of a heat stress monitor is described, and the model function for measurement uncertainty is given. Sensitivity coefficients were derived according to GUM. Two-pressure humidity generators were used to generate a controlled environment. Heat stress monitor was calibrated inside of the generator. Two-pressure humidity generator, which is located in Turkish Standard Institution, was used as the reference device. This device is traceable to national standards. Two-pressure humidity generator includes reference temperature Pt-100 sensors. The reference sensor was sheltered with a wet wick for the calibration of natural wet-bulb thermometer. The reference sensor was centred into a black globe that has got 150 mm diameter for the calibration of the black globe thermometer.

  2. Atomic recombination rate determination through heat-transfer measurement.

    Science.gov (United States)

    Park, C.; Anderson, L. A.; Sheldahl, R. E.

    1973-01-01

    A theoretical and experimental demonstration is presented which shows that under suitable conditions the volume recombination coefficient can be determined by measuring the heat transfer rate into the wall of a cylinder through which a dissociated stream is passing. The experimental results obtained are in agreement with those of other investigators.

  3. Measurement of the Convective Heat-Transfer Coefficient

    Science.gov (United States)

    Conti, Rosaria; Gallitto, Aurelio Agliolo; Fiordilino, Emilio

    2014-01-01

    We propose an experiment for investigating how objects cool down toward the thermal equilibrium with their surroundings. We describe the time dependence of the temperature difference of the cooling objects and the environment with an exponential decay function. By measuring the thermal constant t, we determine the convective heat-transfer…

  4. Effect of crystallinity and irradiation on thermal properties and specific heat capacity of LDPE and LDPE/EVA

    Energy Technology Data Exchange (ETDEWEB)

    Borhani zarandi, Mahmoud, E-mail: mborhani@yazduni.ac.ir [Physics Department, Yazd University, Yazd (Iran, Islamic Republic of); Amrollahi Bioki, Hojjat; Mirbagheri, Zahra-alsadat [Physics Department, Yazd University, Yazd (Iran, Islamic Republic of); Tabbakh, Farshid [Institute of Nuclear Science and Technology, Tehran (Iran, Islamic Republic of); Mirjalili, Ghazanfar [Physics Department, Yazd University, Yazd (Iran, Islamic Republic of)

    2012-01-15

    In this paper a series of low-density polyethylene (LDPE) blends with different percentages (10%, 20%, and 30%) of EVA and sets of low-density polyethylene sheets were prepared. This set consists of four subsets, which were made under different cooling methods: fast cooling in liquid nitrogen, cooling with cassette, exposing in open air, and cooling in oven, to investigate the crystallinity effects. All of the samples were irradiated with 10 MeV electron-beam in the dose range of 0-250 kGy using a Rhodotron accelerator system. The variation of thermal conductivity (k) and specific heat capacity (C{sub p}) of all of the samples were measured. We found that, for the absorption dose less than 150 kGy, k of the LDPE samples at a prescribed temperature range decreased by increasing the amount of dose, but then the change is insignificant. With increasing the crystallinity, k of the LDPE samples increased, whereas C{sub p} of this material is decreased. In the case of LDPE/EVA blends, for the dose less than 150 kGy, C{sub p} (at 40 Degree-Sign C) and k (in average) decreased, but then the change is insignificant. With increasing the amount of additive (EVA), C{sub p} and k increased.

  5. Temperature dependence of the heat capacities in the solid state of 18 mono-, di-, and poly-saccharides

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez-Segura, Gerardo O. [Laboratorio de Biofisicoquimica, Departamento de Fisicoquimica, Facultad de Quimica, Universidad Nacional Autonoma de Mexico, Mexico D.F. 04510 (Mexico); Campos, Myriam [Departamento de Quimica, Centro de Investigacion y Estudios Avanzados del I.P.N., Apdo. Postal 14-740, Mexico D.F. 07000 (Mexico); Costas, Miguel [Laboratorio de Biofisicoquimica, Departamento de Fisicoquimica, Facultad de Quimica, Universidad Nacional Autonoma de Mexico, Mexico D.F. 04510 (Mexico)], E-mail: costasmi@servidor.unam.mx; Torres, Luis A. [Departamento de Quimica, Centro de Investigacion y Estudios Avanzados del I.P.N., Apdo. Postal 14-740, Mexico D.F. 07000 (Mexico)], E-mail: ltorres@cinvestav.mx

    2009-01-15

    The temperature dependence of the heat capacities in solid state C{sub p}(T) of 18 mono-, di-, and poly-saccharides has been determined using a power-compensation differential scanning calorimeter. The saccharides were {alpha}-D-xylose, D-ribose, 2-deoxy-D-ribose, methyl-{beta}-D-ribose, {alpha}-D-glucose, 2-deoxy-D-glucose, {alpha}-D-mannose, {beta}-D-fructose, {alpha}-D-galactose, methyl-{alpha}-D-glucose, sucrose, maltose monohydrate, {alpha}-lactose monohydrate, cellobiose, maltotriose, N-acetyl-D-glucosamine, {alpha}-cyclodextrin, and {beta}-cyclodextrin. The measurements were carried out at atmospheric pressure and from T = (288.15 to 358.15) K for 15 saccharides and from T = (288.15 to 328.15) K for D-ribose, 2-deoxy-D-ribose, and methyl-{beta}-D-ribose. The present results are compared against literature values both at single temperatures, where most of the data are available, and throughout a range of temperatures, i.e., for C{sub p}(T). The predictions of a recently published correlation for organic solids are briefly discussed. By grouping saccharides in subsets, our present results can be used to compare amongst saccharide isomers and to assess the effect of different chemical groups and molecular size.

  6. Preliminary phase relations involving glaucophane and applications to high pressure petrology: new heat capacity and thermodynamic data

    Science.gov (United States)

    Holland, Timothy J. B.

    1988-05-01

    New heat capacity measurements and cell volume data are presented for a very magnesian glaucophane from a Tauern Window eclogite. These data are combined with estimated entropy, thermal expansion, and compressibility data to generate an enthalpy of formation for glaucophane from experimentally determined phase equilibria. The data are supported by preliminary experiments of the author and provide consistent calculations on the pressure of formation of the Tauern eclogites and on the position of the blueschist-greenschist transformation reaction as studied experimentally by Maruyama et al. (1986). The resulting thermodynamic data for glaucophane may be combined with the dataset of Holland and Powell (1985) to calculate phase relations for blueschists and eclogites. The stability of magnesian glaucophane lies in the pressure range between 8 and 32 kbars at 400° C and between 13 and 33 kbars at 600° C, and the unusual eclogite assemblage of glaucophane+kyanite from the Tauern Window is restricted to pressures above 20 kbars at high water activity.

  7. Thermal expansion and the heat capacity of nanocrystalline and coarse-crystalline silver sulfide Ag2S

    Science.gov (United States)

    Sadovnikov, S. I.; Gusev, A. I.

    2017-09-01

    The thermal expansion and the heat capacity of coarse-crystalline and nanocrystalline silver sulfide Ag2S were studied by dilatometry and differential scanning calorimentry for the first time in the temperature range 290-970 K. It is found that the thermal expansion coefficient and the heat capacity of nanocrystalline silver sulfide in this temperature range are higher than those in the case of the coarse-crystalline sulfide. It is revealed that the transformation of α-Ag2S acanthite to β-Ag2S argentite and β-Ag2S argentite to γ-Ag2S phase are the first-order phase transitions; the temperatures and the enthalpies of these transformations have been determined.

  8. Bias induced modulation of electrical and thermal conductivity and heat capacity of BN and BN/graphene bilayers

    Science.gov (United States)

    Chegel, Raad

    2017-04-01

    By using the tight binding approximation and Green function method, the electronic structure, density of state, electrical conductivity, heat capacity of BN and BN/graphene bilayers are investigated. The AA-, AB1- and AB2- BN/graphene bilayers have small gap unlike to BN bilayers which are wide band gap semiconductors. Unlike to BN bilayer, the energy gap of graphene/BN bilayers increases with external field. The magnitude of the change in the band gap of BN bilayers is much higher than the graphene/BN bilayers. Near absolute zero, the σ(T) is zero for BN bilayers and it increases with temperature until reaches maximum value then decreases. The BN/graphene bilayers have larger electrical conductivity larger than BN bilayers. For both bilayers, the specific heat capacity has a Schottky anomaly.

  9. Bias induced modulation of electrical and thermal conductivity and heat capacity of BN and BN/graphene bilayers

    Energy Technology Data Exchange (ETDEWEB)

    Chegel, Raad, E-mail: Raad.chegel@gmail.com

    2017-04-15

    By using the tight binding approximation and Green function method, the electronic structure, density of state, electrical conductivity, heat capacity of BN and BN/graphene bilayers are investigated. The AA-, AB{sub 1}- and AB{sub 2}- BN/graphene bilayers have small gap unlike to BN bilayers which are wide band gap semiconductors. Unlike to BN bilayer, the energy gap of graphene/BN bilayers increases with external field. The magnitude of the change in the band gap of BN bilayers is much higher than the graphene/BN bilayers. Near absolute zero, the σ(T) is zero for BN bilayers and it increases with temperature until reaches maximum value then decreases. The BN/graphene bilayers have larger electrical conductivity larger than BN bilayers. For both bilayers, the specific heat capacity has a Schottky anomaly.

  10. Methodology of heat transfer and flow resistance measurement for matrices of rotating regenerative heat exchangers

    Directory of Open Access Journals (Sweden)

    Butrymowicz Dariusz

    2016-09-01

    Full Text Available The theoretical basis for the indirect measurement approach of mean heat transfer coefficient for the packed bed based on the modified single blow technique was presented and discussed in the paper. The methodology of this measurement approach dedicated to the matrix of the rotating regenerative gas heater was discussed in detail. The testing stand consisted of a dedicated experimental tunnel with auxiliary equipment and a measurement system are presented. Selected experimental results are presented and discussed for selected types of matrices of regenerative air preheaters for the wide range of Reynolds number of gas. The agreement between the theoretically predicted and measured temperature profiles was demonstrated. The exemplary dimensionless relationships between Colburn heat transfer factor, Darcy flow resistance factor and Reynolds number were presented for the investigated matrices of the regenerative gas heater.

  11. Measurement of a surface heat flux and temperature

    Science.gov (United States)

    Davis, R. M.; Antoine, G. J.; Diller, T. E.; Wicks, A. L.

    1994-01-01

    The Heat Flux Microsensor is a new sensor which was recently patented by Virginia Tech and is just starting to be marketed by Vatell Corp. The sensor is made using the thin-film microfabrication techniques directly on the material that is to be measured. It consists of several thin-film layers forming a differential thermopile across a thermal resistance layer. The measured heat flux q is proportional to the temperature difference across the resistance layer q= k(sub g)/delta(sub g) x (t(sub 1) - T(sub 2)), where k(sub g) is the thermal conductivity and delta (sub g) is the thickness of the thermal resistance layer. Because the gages are sputter coated directly onto the surface, their total thickness is less than 2 micrometers, which is two orders of magnitude thinner than previous gages. The resulting temperature difference across the thermal resistance layer (delta is less than 1 micrometer) is very small even at high heat fluxes. To generate a measurable signal many thermocouple pairs are put in series to form a differential thermopile. The combination of series thermocouple junctions and thin-film design creates a gage with very attractive characteristics. It is not only physically non-intrusive to the flow, but also causes minimal disruption of the surface temperature. Because it is so thin, the response time is less than 20 microsec. Consequently, the frequency response is flat from 0 to over 50 kHz. Moreover, the signal of the Heat Flux Microsensor is directly proportional to the heat flux. Therefore, it can easily be used in both steady and transient flows, and it measures both the steady and unsteady components of the surface heat flux. A version of the Heat Flux Microsensor has been developed to meet the harsh demands of combustion environments. These gages use platinum and platinum-10 percent rhodium as the thermoelectric materials. The thermal resistance layer is silicon monoxide and a protective coating of Al2O3 is deposited on top of the sensor. The

  12. Network optimization for enhanced resilience of urban heat island measurements

    OpenAIRE

    Honjo, Tsuyoshi; Yamato, Hiroaki; Mikami, Takehiko; Grimmond, C.S.B.

    2015-01-01

    The urban heat island is a well-known phenomenon that impacts a wide variety of city operations. With greater availability of cheap meteorological sensors, it is possible to measure the spatial patterns of urban atmospheric characteristics with greater resolution. To develop robust and resilient networks, recognizing sensors may malfunction, it is important to know when measurement points are providing additional information and also the minimum number of sensors needed to provide spatial inf...

  13. Magneto-heat capacity study on Kondo lattice system Ce(Ni1−xCux ...

    Indian Academy of Sciences (India)

    Abstract. Heat capacity studies on the Kondo lattice system Ce(Ni1−xCux)2Al3, in the presence of magnetic fields, were reported for x = 0.0−0.4. The physical properties of the intermediate compositions like x = 0.3 and 0.4 were known for their enhanced thermoelectric power and hence have been analysed with an extra ...

  14. Native and Heated Hydrolysates of Milk Proteins and Their Capacity to Inhibit Lipid Peroxidation in the Zebrafish Larvae Model.

    Science.gov (United States)

    Carrillo, Wilman; Guzmán, Xavier; Vilcacundo, Edgar

    2017-09-14

    Casein and whey proteins with and without heat treatment were obtained of whole milk and four commercial milks in Ecuador, and were hydrolyzed. Then, their capacity to inhibit the lipid peroxidation using the TBARS method was evaluated at concentrations of 0.02, 0.04, 0.2, and, 0.4 mg/mL. Native and heated hydrolysates of milk proteins present high inhibitions of lipid peroxidation with a dose dependent effect both in vivo and in vitro tests. Casein and whey proteins obtained from whole milk were the ones with the highest anti-oxidant activity in vitro and in vivo test. Native casein hydrolysate at 0.4 mg/mL present a value of 55.55% of inhibition of lipid peroxidation and heated casein hydrolysate at 0.4 mg/mL presents a value of 58.00% of inhibition of lipid peroxidation. Native whey protein at 0.4 mg/mL present a value of 34.84% of inhibition of lipid peroxidation, and heated whey protein at 0.4 mg/mL presents a value of 40.86% of inhibition of lipid peroxidation. Native and heated casein hydrolysates were more active than native and heated whey protein hydrolysates. Heat treatments have an effect of increasing the in vitro inhibition of lipid peroxidation of hydrolysates of milk protein. Casein and whey hydrolysates were able to inhibiting lipid peroxidation in the zebrafish larvae model. Native casein hydrolysate obtained of whole milk presents 48.35% of inhibition TBARS in vivo, this activity was higher in heated casein hydrolysate obtained of whole milk with a value of 56.28% of inhibition TBARS in vivo. Native whey protein hydrolysate obtained of whole milk presents 35.30% of inhibition TBARS, and heated whey protein hydrolysate obtained of whole milk was higher, with a value of 43.60% of inhibition TBARS in vivo.

  15. Compressibility measurements of gases using externally heated pressure vessels.

    Science.gov (United States)

    Presnall, D. C.

    1971-01-01

    Most of the data collected under conditions of high temperature and pressure have been determined using a thick-walled bomb of carefully measured and fixed volume which is externally heated by an electric furnace or a thermostatically controlled bath. There are numerous variations on the basic method depending on the pressure-temperature range of interest, and the particular gas or gas mixture being studied. The construction and calibration of the apparatus is discussed, giving attention to the pressure vessel, the volume of the bomb, the measurement of pressure, the control and measurement of temperature, and the measurement of the amount and composition of gas in the bomb.

  16. A study on specific heat capacities of Li-ion cell components and their influence on thermal management

    Science.gov (United States)

    Loges, André; Herberger, Sabrina; Seegert, Philipp; Wetzel, Thomas

    2016-12-01

    Thermal models of Li-ion cells on various geometrical scales and with various complexity have been developed in the past to account for the temperature dependent behaviour of Li-ion cells. These models require accurate data on thermal material properties to offer reliable validation and interpretation of the results. In this context a thorough study on the specific heat capacities of Li-ion cells starting from raw materials and electrode coatings to representative unit cells of jelly rolls/electrode stacks with lumped values was conducted. The specific heat capacity is reported as a function of temperature and state of charge (SOC). Seven Li-ion cells from different manufactures with different cell chemistry, application and design were considered and generally applicable correlations were developed. A 2D thermal model of an automotive Li-ion cell for plug-in hybrid electric vehicle (PHEV) application illustrates the influence of specific heat capacity on the effectivity of cooling concepts and the temperature development of Li-ion cells.

  17. Heat-capacity changes in host-guest complexation by Coulomb interactions in aqueous solution.

    Science.gov (United States)

    Kano, Koji; Ishida, Yoshiyuki; Kitagawa, Kohei; Yasuda, Mayuko; Watanabe, Maki

    2007-10-01

    Heat-capacity changes (deltaC(p)0) were determined for the complexation of 1-alkanecarboxylates with protonated hexakis(6-amino-6-deoxy)-alpha-cyclodextrin (per-NH3(+)-alpha-CD) and heptakis(6-amino-6-deoxy)-beta-cyclodextrin (per-NH3(+)-beta-CD). DeltaC(p)0 decreased with an increase in the binding constant (K) and plateaued at K = 4000 M(-1). The complexes of 1-pentanoate, 1-hexanoate, and 1-heptanoate with per-NH3(+)-alpha-CD are classified as the host-guest system in which the size of the guest fits the CD cavity well. In such a system, van der Waals interaction is the major force for complexation, leading to a negative deltaH0 value. Simultaneously, the water molecules around the hydrophobic alkyl chain of the guest and inside the CD cavity are released to the aqueous bulk phase, leading to a positive deltaS0 value. The negative deltaC(p)0 value in such complexation is ascribed to dehydration of the hydrophobic alkyl chain of the guest and extrusion of the water molecules inside the CD cavity. Meanwhile, the complexes that show positive deltaC(p)0 values are characterized by complexation in which the guest molecules are significantly smaller than the CD cavities. In such a case, the complexation is endothermic and driven by the entropy gain. When the guest is much smaller than the CD cavity, the main binding force should be Coulomb interaction. To form an ionic bond, dehydration of the charged groups must occur. This process is endothermic and leads to positive deltaH0 and deltaS0 values. As the top of the CD cavity is capped by a small but hydrophobic alkyl chain, the water molecules inside the CD cavity may form the iceberg structure. This process must be accompanied by a positive deltaC(p)0 value. Hence, the complexation of a small guest with the CD with a large cavity through Coulomb interactions shows positive and large deltaC(p)0 values. These conclusions were applied to the electrostatic binding of proteins with an anionic ligand.

  18. Cryogenic mechanical loss measurements of heat-treated hafnium dioxide

    Science.gov (United States)

    Abernathy, M. R.; Reid, S.; Chalkley, E.; Bassiri, R.; Martin, I. W.; Evans, K.; Fejer, M. M.; Gretarsson, A.; Harry, G. M.; Hough, J.; MacLaren, I.; Markosyan, A.; Murray, P.; Nawrodt, R.; Penn, S.; Route, R.; Rowan, S.; Seidel, P.

    2011-10-01

    Low mechanical loss, high index-of-refraction thin-film coating materials are of particular interest to the gravitational wave detection community, where reduced mirror coating thermal noise in gravitational wave detectors is desirable. Current studies are focused on understanding the loss of amorphous metal oxides such as SiO2, Ta2O5 and HfO2. Here, we report recent measurements of the temperature dependence of the mechanical loss of ion-beam sputtered hafnium dioxide (HfO2) coatings that have undergone heat treatment. The results indicate that, even when partially crystallized, these coatings have lower loss than amorphous Ta2O5 films below ~100 K and that their loss exhibits some features which are heat-treatment dependent in the temperature range of ~100-200 K, with higher heat treatment yielding lower mechanical loss. The potential for using silica doping of hafnia coatings to prevent crystallization is discussed.

  19. Heat capacity of quantum adsorbates: Hydrogen and helium on evaporated gold films

    Energy Technology Data Exchange (ETDEWEB)

    Birmingham, J.T. [Univ. of California, Berkeley, CA (United States). Dept. of Physics]|[Lawrence Berkeley National Lab., CA (United States). Materials Sciences Div.

    1996-06-01

    The author has constructed an apparatus to make specific heat measurements of quantum gases adsorbed on metallic films at temperatures between 0.3 and 4 K. He has used this apparatus to study quench-condensed hydrogen films between 4 and 923 layers thick with J = 1 concentrations between 0.28 and 0.75 deposited on an evaporated gold surface. He has observed that the orientational ordering of the J = 1 molecules depends on the substrate temperature during deposition of the hydrogen film. He has inferred that the density of the films condensed at the lowest temperatures is 25% higher than in bulk H{sub 2} crystals and have observed that the structure of those films is affected by annealing at 3.4 K. The author has measured the J = 1 to J = 0 conversion rate to be comparable to that of the bulk for thick films; however, he found evidence that the gold surface catalyzes conversion in the first two to four layers. He has also used this apparatus to study films of {sup 4}He less than one layer thick adsorbed on an evaporated gold surface. He shows that the phase diagram of the system is similar to that for {sup 4}He/graphite although not as rich in structure, and the phase boundaries occur at different coverages and temperatures. At coverages below about half a layer and at sufficiently high temperatures, the {sup 4}He behaves like a two-dimensional noninteracting Bose gas. At lower temperatures and higher coverages, liquidlike and solidlike behavior is observed. The Appendix shows measurements of the far-infrared absorptivity of the high-{Tc} superconductor La{sub 1.87}Sr{sub 0.13}CuO{sub 4}.

  20. Temperature measurements using multicolor pyrometry in thermal radiation heating environments.

    Science.gov (United States)

    Fu, Tairan; Liu, Jiangfan; Duan, Minghao; Zong, Anzhou

    2014-04-01

    Temperature measurements are important for thermal-structural experiments in the thermal radiation heating environments such as used for thermal-structural stress analyses. This paper describes the use of multicolor pyrometry for the measurements of diffuse surfaces in thermal radiation environments that eliminates the effects of background radiation reflections and unknown emissivities based on a least-squares algorithm. The near-infrared multicolor pyrometer had a spectral range of 1100-2400 nm, spectrum resolution of 6 nm, maximum sampling frequency of 2 kHz, working distance of 0.6 m to infinity, temperature range of 700-1700 K. The pyrometer wavelength response, nonlinear intensity response, and spectral response were all calibrated. The temperature of a graphite sample irradiated by quartz lamps was then measured during heating and cooling using the least-squares algorithm based on the calibrated irradiation data. The experiments show that higher temperatures and longer wavelengths are more suitable for the thermal measurements in the quartz lamp radiation heating system. This analysis provides a valuable method for temperature measurements of diffuse surfaces in thermal radiation environments.

  1. Temperature measurements using multicolor pyrometry in thermal radiation heating environments

    Energy Technology Data Exchange (ETDEWEB)

    Fu, Tairan, E-mail: trfu@mail.tsinghua.edu.cn [Key Laboratory for Thermal Science and Power Engineering of Ministry of Education, Department of Thermal Engineering, Tsinghua University, Beijing 100084 (China); Beijing Key Laboratory of CO2 Utilization and Reduction Technology, Beijing 100084 (China); Liu, Jiangfan; Duan, Minghao; Zong, Anzhou [Key Laboratory for Thermal Science and Power Engineering of Ministry of Education, Department of Thermal Engineering, Tsinghua University, Beijing 100084 (China)

    2014-04-15

    Temperature measurements are important for thermal-structural experiments in the thermal radiation heating environments such as used for thermal-structural stress analyses. This paper describes the use of multicolor pyrometry for the measurements of diffuse surfaces in thermal radiation environments that eliminates the effects of background radiation reflections and unknown emissivities based on a least-squares algorithm. The near-infrared multicolor pyrometer had a spectral range of 1100–2400 nm, spectrum resolution of 6 nm, maximum sampling frequency of 2 kHz, working distance of 0.6 m to infinity, temperature range of 700–1700 K. The pyrometer wavelength response, nonlinear intensity response, and spectral response were all calibrated. The temperature of a graphite sample irradiated by quartz lamps was then measured during heating and cooling using the least-squares algorithm based on the calibrated irradiation data. The experiments show that higher temperatures and longer wavelengths are more suitable for the thermal measurements in the quartz lamp radiation heating system. This analysis provides a valuable method for temperature measurements of diffuse surfaces in thermal radiation environments.

  2. Temperature measurements using multicolor pyrometry in thermal radiation heating environments

    Science.gov (United States)

    Fu, Tairan; Liu, Jiangfan; Duan, Minghao; Zong, Anzhou

    2014-04-01

    Temperature measurements are important for thermal-structural experiments in the thermal radiation heating environments such as used for thermal-structural stress analyses. This paper describes the use of multicolor pyrometry for the measurements of diffuse surfaces in thermal radiation environments that eliminates the effects of background radiation reflections and unknown emissivities based on a least-squares algorithm. The near-infrared multicolor pyrometer had a spectral range of 1100-2400 nm, spectrum resolution of 6 nm, maximum sampling frequency of 2 kHz, working distance of 0.6 m to infinity, temperature range of 700-1700 K. The pyrometer wavelength response, nonlinear intensity response, and spectral response were all calibrated. The temperature of a graphite sample irradiated by quartz lamps was then measured during heating and cooling using the least-squares algorithm based on the calibrated irradiation data. The experiments show that higher temperatures and longer wavelengths are more suitable for the thermal measurements in the quartz lamp radiation heating system. This analysis provides a valuable method for temperature measurements of diffuse surfaces in thermal radiation environments.

  3. Proposed Measures to Protect Temporary Roofs from Unwanted Heat Gains

    Directory of Open Access Journals (Sweden)

    Omar S. Asfour

    2017-06-01

    Full Text Available This study focuses on the uncompleted multi-storey residential buildings located in hot climates. This construction pattern is common in the case of incremental housing, where additional floors are added to the building as housing needs grow. Top roofs in these buildings are usually left without thermal insulation until the rest of upper floors are erected. This causes higher thermal discomfort in the top flats compared to the lower ones. Thus, the aim of this study is to investigate thermal effect of some proposed temporary measures that are intended to protect these roofs from unwanted heat gains until the rest of storeys are constructed. This has been carried out using thermal modelling to find out the effect of these measures on the amount of heat transfer through the roof in both summer and winter times. The analysis showed that it is possible to achieve competent thermal protection of the top roof compared to the layered thermal insulation using simple, cost-effective, and reversible measures. Among the examined measures, covering the roof with white foldable sheets and the use of pergolas have been found to be the most effective measures. In both cases, a reduction of 38% in conductive heat transfer through the top roof in summer was observed compared to the unprotected modelling case.

  4. High temperature thermographic measurements of laser heated silica

    Energy Technology Data Exchange (ETDEWEB)

    Elhadj, S; Yang, S T; Matthews, M J; Cooke, D J; Bude, J D; Johnson, M; Feit, M; Draggoo, V; Bisson, S E

    2009-11-02

    In situ spatial and temporal surface temperature profiles of CO{sub 2} laser-heated silica were obtained using a long wave infrared (LWIR) HgCdTe camera. Solutions to the linear diffusion equation with volumetric and surface heating are shown to describe the temperature evolution for a range of beam powers, over which the peak surface temperature scales linearly with power. These solutions were used with on-axis steady state and transient experimental temperatures to extract thermal diffusivity and conductivity for a variety of materials, including silica, spinel, sapphire, and lithium fluoride. Experimentally-derived thermal properties agreed well with reported values and, for silica, thermal conductivity and diffusivity are shown to be approximately independent of temperature between 300 and 2800K. While for silica our analysis based on a temperature independent thermal conductivity is shown to be accurate, for other materials studied this treatment yields effective thermal properties that represent reasonable approximations for laser heating. Implementation of a single-wavelength radiation measurement in the semi-transparent regime is generally discussed, and estimates of the apparent temperature deviation from the actual outer surface temperature are also presented. The experimental approach and the simple analysis presented yield surface temperature measurements that can be used to validate more complex physical models, help discriminate dominant heat transport mechanisms, and to predict temperature distribution and evolution during laser-based material processing.

  5. Heat capacity studies of single-crystalline CePt{sub 4}In

    Energy Technology Data Exchange (ETDEWEB)

    Pikul, A.P. [Polish Academy of Sciences, Institute of Low Temperature and Structure Research, P Nr 1410, 50-950 Wroclaw 2 (Poland); Max Planck Institute for Chemical Physics of Solids, Noethnitzer Str. 40, 01187 Dresden (Germany)], E-mail: A.Pikul@int.pan.wroc.pl; Kaczorowski, D.; Bukowski, Z. [Polish Academy of Sciences, Institute of Low Temperature and Structure Research, P Nr 1410, 50-950 Wroclaw 2 (Poland); Steglich, F. [Max Planck Institute for Chemical Physics of Solids, Noethnitzer Str. 40, 01187 Dresden (Germany)

    2008-04-01

    Single crystals of CePt{sub 4}In have been studied by means of specific heat measurements performed at low temperatures (down to 60 mK) and in high magnetic fields (up to 9 T). In zero magnetic field the {delta}C/T ratio strongly increases with decreasing temperature down to about 250 mK, where a broad maximum ({approx}1.75Jmol{sup -1}K{sup -2}) occurs. At lower temperatures {delta}C/T slightly diminishes and finally saturates at a value of about 1.7Jmol{sup -1}K{sup -2}. Upon applying magnetic field the maximum in {delta}C/T(T) disappears (it is not visible already in 0.5 T) and the magnitude of {delta}C/T becomes significantly lower. We argue that the observed anomaly in {delta}C(T)/T is due to some magnetic ordering of the cerium magnetic moments, in line with our previous statement on the localized character of the 4f-electrons in this compound.

  6. Simultaneous Measurement of Thermal Conductivity and Specific Heat in a Single TDTR Experiment

    Science.gov (United States)

    Sun, Fangyuan; Wang, Xinwei; Yang, Ming; Chen, Zhe; Zhang, Hang; Tang, Dawei

    2018-01-01

    Time-domain thermoreflectance (TDTR) technique is a powerful thermal property measurement method, especially for nano-structures and material interfaces. Thermal properties can be obtained by fitting TDTR experimental data with a proper thermal transport model. In a single TDTR experiment, thermal properties with different sensitivity trends can be extracted simultaneously. However, thermal conductivity and volumetric heat capacity usually have similar trends in sensitivity for most materials; it is difficult to measure them simultaneously. In this work, we present a two-step data fitting method to measure the thermal conductivity and volumetric heat capacity simultaneously from a set of TDTR experimental data at single modulation frequency. This method takes full advantage of the information carried by both amplitude and phase signals; it is a more convenient and effective solution compared with the frequency-domain thermoreflectance method. The relative error is lower than 5 % for most cases. A silicon wafer sample was measured by TDTR method to verify the two-step fitting method.

  7. Infrared Low Temperature Turbine Vane Rough Surface Heat Transfer Measurements

    Science.gov (United States)

    Boyle, R. J.; Spuckler, C. M.; Lucci, B. L.; Camperchioli, W. P.

    2000-01-01

    Turbine vane heat transfer distributions obtained using an infrared camera technique are described. Infrared thermography was used because noncontact surface temperature measurements were desired. Surface temperatures were 80 C or less. Tests were conducted in a three vane linear cascade, with inlet pressures between 0.14 and 1.02 atm., and exit Mach numbers of 0.3, 0.7, and 0.9, for turbulence intensities of approximately 1 and 10%. Measurements were taken on the vane suction side, and on the pressure side leading edge region. The designs for both the vane and test facility are discussed. The approach used to account for conduction within the vane is described. Midspan heat transfer distributions are given for the range of test conditions.

  8. Measuring the specific caesium sorption capacity of soils, sediments and clay minerals.

    NARCIS (Netherlands)

    Koning, de A.; Konoplev, A.V.; Comans, R.N.J.

    2007-01-01

    Two methods to quantify the specific Cs sorption capacity of soils and sediments, which is generally believed to be associated with the Frayed Edge Sites (FES) of illitic clay minerals, are described in detail and are critically reviewed. The first method is a direct measurement of the FES capacity,

  9. Nineteenth-Century Measurements of the Mechanical Equivalent of Heat

    Science.gov (United States)

    Greenslade, Thomas B.

    2002-04-01

    Today the measurement of the mechanical equivalent of heat is a laboratory exercise in which the student tries to come close to the accepted value. How different was the attitude of the 19th-century physicists and engineers, for which the value was a key link between mechanics and thermodynamics, two seemingly separate domains of physics. This article discusses some of the pioneering experiments, translating them into modern nomenclature and units.

  10. Measurement and Evaluation of Heating Performance of Heat Pump Systems Using Wasted Heat from Electric Devices for an Electric Bus

    OpenAIRE

    Cho, Chung-Won; Lee, Ho-Seong; Won, Jong-Phil; Lee, Moo-Yeon

    2012-01-01

    The objective of this study is to investigate heating performance characteristics of a coolant source heat pump using the wasted heat from electric devices for an electric bus. The heat pump, using R-134a, is designed for heating a passengers’ compartment by using discharged energy from the coolant of electric devices, such as motors and inverters of the electric bus. The heating performance of the heat pump was tested by varying the operating parameters, such as outdoor temperature and volum...

  11. Distributed Sensible Heat Flux Measurements for Wireless Sensor Networks

    Science.gov (United States)

    Huwald, H.; Brauchli, T.; Lehning, M.; Higgins, C. W.

    2015-12-01

    The sensible heat flux component of the surface energy balance is typically computed using eddy covariance or two point profile measurements while alternative approaches such as the flux variance method based on convective scaling has been much less explored and applied. Flux variance (FV) certainly has a few limitations and constraints but may be an interesting and competitive method in low-cost and power limited wireless sensor networks (WSN) with the advantage of providing spatio-temporal sensible heat flux over the domain of the network. In a first step, parameters such as sampling frequency, sensor response time, and averaging interval are investigated. Then we explore the applicability and the potential of the FV method for use in WSN in a field experiment. Low-cost sensor systems are tested and compared against reference instruments (3D sonic anemometers) to evaluate the performance and limitations of the sensors as well as the method with respect to the standard calculations. Comparison experiments were carried out at several sites to gauge the flux measurements over different surface types (gravel, grass, water) from the low-cost systems. This study should also serve as an example of spatially distributed sensible heat flux measurements.

  12. Measuring the temperature history of isochorically heated warm dense metals

    Science.gov (United States)

    McGuffey, Chris; Kim, J.; Park, J.; Moody, J.; Emig, J.; Heeter, B.; Dozieres, M.; Beg, Fn; McLean, Hs

    2017-10-01

    A pump-probe platform has been designed for soft X-ray absorption spectroscopy near edge structure measurements in isochorically heated Al or Cu samples with temperature of 10s to 100s of eV. The method is compatible with dual picosecond-class laser systems and may be used to measure the temperature of the sample heated directly by the pump laser or by a laser-driven proton beam Knowledge of the temperature history of warm dense samples will aid equation of state measurements. First, various low- to mid-Z targets were evaluated for their suitability as continuum X-ray backlighters over the range 200-1800 eV using a 10 J picosecond-class laser with relativistic peak intensity Alloys were found to be more suitable than single-element backlighters. Second, the heated sample package was designed with consideration of target thickness and tamp layers using atomic physics codes. The results of the first demonstration attempts will be presented. This work was supported by the U.S. DOE under Contract No. DE-SC0014600.

  13. Thermoeconomic Evaluation of Modular Organic Rankine Cycles for Waste Heat Recovery over a Broad Range of Heat Source Temperatures and Capacities

    Directory of Open Access Journals (Sweden)

    Markus Preißinger

    2017-02-01

    Full Text Available Industrial waste heat recovery by means of an Organic Rankine Cycle (ORC can contribute to the reduction of CO2 emissions from industries. Before market penetration, high efficiency modular concepts have to be developed to achieve appropriate economic value for industrial decision makers. This paper aims to investigate modularly designed ORC systems from a thermoeconomic point of view. The main goal is a recommendation for a suitable chemical class of working fluids, preferable ORC design and a range of heat source temperatures and thermal capacities in which modular ORCs can be economically feasible. For this purpose, a thermoeconomic model has been developed which is based on size and complexity parameters of the ORC components. Special emphasis has been laid on the turbine model. The paper reveals that alkylbenzenes lead to higher exergetic efficiencies compared to alkanes and siloxanes. However, based on the thermoeconomic model, the payback periods of the chemical classes are almost identical. With the ORC design, the developed model and the boundary conditions of this study, hexamethyldisiloxane is a suitable working fluid and leads to a payback period of less than 5 years for a heat source temperature of 400 to 600 °C and a mass flow rate of the gaseous waste heat stream of more than 4 kg/s.

  14. Heat Transfer Measurements for a Film Cooled Turbine Vane Cascade

    Science.gov (United States)

    Poinsatte, Philip E.; Heidmann, James D.; Thurman, Douglas R.

    2008-01-01

    Experimental heat transfer and pressure measurements were obtained on a large scale film cooled turbine vane cascade. The objective was to investigate heat transfer on a commercial high pressure first stage turbine vane at near engine Mach and Reynolds number conditions. Additionally blowing ratios and coolant density were also matched. Numerical computations were made with the Glenn-HT code of the same geometry and compared with the experimental results. A transient thermochromic liquid crystal technique was used to obtain steady state heat transfer data on the mid-span geometry of an instrumented vane with 12 rows of circular and shaped film cooling holes. A mixture of SF6 and Argon gases was used for film coolant to match the coolant-to-gas density ratio of a real engine. The exit Mach number and Reynolds number were 0.725 and 2.7 million respectively. Trends from the experimental heat transfer data matched well with the computational prediction, particularly for the film cooled case.

  15. Ice ingestion with a long rest interval increases the endurance exercise capacity and reduces the core temperature in the heat.

    Science.gov (United States)

    Naito, Takashi; Iribe, Yuka; Ogaki, Tetsuro

    2017-01-05

    The timing in which ice before exercise should be ingested plays an important role in optimizing its success. However, the effects of differences in the timing of ice ingestion before exercise on cycling capacity, and thermoregulation has not been studied. The aim of the present study was to assess the effect of length of time after ice ingestion on endurance exercise capacity in the heat. Seven males ingested 1.25 g kg body mass-1 of ice (0.5 °C) or cold water (4 °C) every 5 min, six times. Under three separate conditions after ice or water ingestion ([1] taking 20 min rest after ice ingestion, [2] taking 5 min rest after ice ingestion, and [3] taking 5 min rest after cold water ingestion), seven physically active male cyclists exercised at 65% of their maximal oxygen uptake to exhaustion in the heat (35 °C, 30% relative humidity). Participants cycled significantly longer following both ice ingestion with a long rest interval (46.0 ± 7.7 min) and that with a short rest interval (38.7 ± 5.7 min) than cold water ingestion (32.3 ± 3.2 min; both p Heat storage under condition of ice ingestion with a long rest interval during the pre-exercise period was significantly lower than that observed with a short rest interval (-4.98 ± 2.50 W m-2; p heat, which is suggested to be driven by a reduced rectal temperature and heat storage before the start of exercise.

  16. Effects of caffeine on endurance capacity and psychological state in young females and males exercising in the heat.

    Science.gov (United States)

    Suvi, Silva; Timpmann, Saima; Tamm, Maria; Aedma, Martin; Kreegipuu, Kairi; Ööpik, Vahur

    2017-01-01

    Acute caffeine ingestion is considered effective in improving endurance capacity and psychological state. However, current knowledge is based on the findings of studies that have been conducted on male subjects mainly in temperate environmental conditions, but some physiological and psychological effects of caffeine differ between the sexes. The purpose of this study was to compare the physical performance and psychological effects of caffeine in young women and men exercising in the heat. Thirteen male and 10 female students completed 2 constant-load walks (60% of thermoneutral peak oxygen consumption on a treadmill until volitional exhaustion) in a hot-dry environment (air temperature, 42 °C; relative humidity, 20%) after caffeine (6 mg·kg -1 ) and placebo (wheat flour) ingestion in a double-blind, randomly assigned, crossover manner. Caffeine, compared with placebo, induced greater increases (p Caffeine decreased (p caffeine was associated with a shorter time to exhaustion. In conclusion, acute caffeine ingestion increases HR and blood lactate levels during exercise in the heat, but it has no impact on thermoregulation or endurance capacity in either gender. Under exercise-heat stress, caffeine reduces ratings of perceived exertion and fatigue in males but not in females.

  17. Correlation of total antioxidant capacity with reactive oxygen species (ROS) consumption measured by oxidative conversion.

    Science.gov (United States)

    Çekiç, Sema Demirci; Çetinkaya, Aydan; Avan, Aslı Neslihan; Apak, Reşat

    2013-06-05

    Although both antioxidant capacity and oxidative conversion (hazard) are important in food and bioanalytical chemistry, there is considerable confusion in the literature between the results of these two types of assays. After the generation of ROS in the medium via Fe(III)-H₂O₂ reaction, attenuation of total oxidative conversion (TOC; as measured by thiobarbituric acid-reactive substances (TBARS) and N,N-dimethyl-p-phenylenediamine (DMPD) assays) was tested for possible correlation with the total antioxidant capacity (TAC; as measured by cupric reducing antioxidant capacity (CUPRAC) and trolox equivalent antioxidant capacity (ABTS/TEAC) assays) of the introduced antioxidant sample. The inverse relationship between oxidative conversion and antioxidant capacity was processed to establish a curvilinear relationship between the absolute values of TAC increments and TOC decrements as a function of added antioxidant concentration. This simple relationship may form a bridge between the two diverse disciplines of medical biochemistry and food analytical chemistry mainly using TOC and TAC results, respectively.

  18. A survey on infrared thermography for convective heat transfer measurements

    Energy Technology Data Exchange (ETDEWEB)

    Astarita, T.; Cardone, G.; Carlomagno, G.M.; Meola, C. [Universita degli Studi di Napoli ' ' Federico II' ' (Italy). Dipartimento di Energetica

    2000-11-01

    During the past several years infrared thermography has evolved into a powerful investigative means, of thermo-fluid-dynamic analysis to measure convective heat fluxes as well as to investigate the surface flow field behaviour over complicated body shapes. The basic concepts that govern this innovative measurement technique together with some particular aspects linked to its use are herein reviewed. Different operating methods together with their implementations are also discussed. Finally, the capability of infrared thermography to deal with several simple, or complex, fluid flow configurations is analysed. (author)

  19. The effect of menstrual cycle phase on exercise capacity measured by treadmill exercise test

    OpenAIRE

    YAZAR, Sadan; Yazici, Mehmet

    2015-01-01

    The aim of this study was to explore the impact of the menstrual phases on exercise capacity parameters measured by a treadmill exercise test in sedentary premenaupausal women. Exercise capacity expressed in terms of metabolic equivalents (MET) and exercise duration was measured by performing treadmill exercise tests in 30 women (mean age: 29 ± 5.8 years) with regular menstrual cycles at two points during their menstrual cycles: the late-follicular (LF) phase and the mid-luteal (ML) phase. Th...

  20. Immersive training: breaking the bubble and measuring the heat.

    Science.gov (United States)

    Pluyter, Jon R; Rutkowski, Anne-F; Jakimowicz, Jack J

    2014-05-01

    Minimal access surgery and, lately, single-incision laparoscopic procedures are challenging and demanding with regard to the skills of the surgeon performing the procedures. This article presents the results of an investigation of the performance and attention focus of 21 medical interns and surgical residents training in an immersive context. That is, training 'in situation', representing more realistically the demands imposed on the surgeons during minimal access surgery. Twenty-one medical interns and surgical residents participated in simulation trainings in an integrated operating room for laparoscopic surgery. Various physiological measures of body heat expenditure were gathered as indicators of mental strain and attention focus. The results of the Mann-Whitney test indicated that participants with a poor performance in the two laparoscopic cholecystectomy cases had a significantly (U = 3, p = 0.038) higher heat flux at the start of the procedure (mean 107.08, standard deviation [SD] 24.34) than those who excelled in the two cases (mean 62.64, SD 23.41). Also, the average frontal head temperature of the participants who failed at the task was significantly lower (mean 33.27, SD 0.52) than those who performed well (mean 33.92, SD 0.27). Surgeons cannot operate in a bubble; thus, they should not be trained in one. Combining heat flux and frontal head temperature could be a good measure of deep involvement and attentional focus during performance of simulated surgical tasks.

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

    Energy Technology Data Exchange (ETDEWEB)

    Difs, Kristina; Trygg, Louise [Department of Management and Engineering, Division of Energy Systems, Linkoeping University, SE-581 83 Linkoeping (Sweden); Bennstam, Marcus; Nordenstam, Lena [Tekniska Verken Linkoeping AB, Box 1500, SE-581 15 Linkoeping (Sweden)

    2010-08-15

    The extensive energy use in the European building sector creates opportunities for implementing energy conservation measures (ECMs) in residential buildings. If ECM are implemented in buildings that are connected to a district heating (DH) system, the operation of DH plants may be affected, which in turn may change both revenue and electricity production in cogeneration plants. In this study a local energy system, containing a DH supplier and its customer, has been analysed when implementing three ECMs: heat load control, attic insulation and electricity savings. This study is unique since it analyses economic and CO{sub 2} impacts of the ECMs in both a user and a supplier perspective in combination with a deregulated European electricity market. Results show that for the local energy system electricity savings should be prioritised over a reduction in DH use, both from an economic and a global CO{sub 2} perspective. For the DH supplier attic insulation demonstrates unprofitable results, even though this measure affects the expensive peak load boilers most. Heat load control is however financially beneficial for both the DH supplier and the residences. Furthermore, the relation between the fixed and variable DH costs is highlighted as a key factor for the profitability of the ECMs. (author)

  2. CARS Temperature Measurements in a Combustion-Heated Supersonic Jet

    Science.gov (United States)

    Tedder, S. A.; Danehy, P. M.; Magnotti, G.; Cutler, A. D.

    2009-01-01

    Measurements were made in a combustion-heated supersonic axi-symmetric free jet from a nozzle with a diameter of 6.35 cm using dual-pump Coherent Anti-Stokes Raman Spectroscopy (CARS). The resulting mean and standard deviation temperature maps are presented. The temperature results show that the gas temperature on the centerline remains constant for approximately 5 nozzle diameters. As the heated gas mixes with the ambient air further downstream the mean temperature decreases. The standard deviation map shows evidence of the increase of turbulence in the shear layer as the jet proceeds downstream and mixes with the ambient air. The challenges of collecting data in a harsh environment are discussed along with influences to the data. The yield of the data collected is presented and possible improvements to the yield is presented are discussed.

  3. Measuring the specific caesium sorption capacity of soils, sediments and clay minerals

    Energy Technology Data Exchange (ETDEWEB)

    De Koning, A. [aEnergy Research Centre of the Netherlands (ECN), Westerduinweg 3, P.O. Box 1, 1755 ZG, Petten (Netherlands); Konoplev, A.V. [Institute of Experimental Meteorology, 82 Lenin Avenue, Obninsk, Kaluga Region, 249020 (Russian Federation); Comans, R.N.J. [Wageningen University, Department of Soil Quality, P.O. Box 8005, 6700 EC Wageningen (Netherlands)

    2007-01-15

    Two methods to quantify the specific Cs sorption capacity of soils and sediments, which is generally believed to be associated with the Frayed Edge Sites (FES) of illitic clay minerals, are described in detail and are critically reviewed. The first method is a direct measurement of the FES capacity, while the second quantifies the combined parameter K{sub D}{sup C}s x [K{sup +}] (=K{sub C}(K-->Cs) x [FES]) i.e. the product of the FES capacity and the affinity of these sites for Cs. Both methods use the bulky AgTU-complex to mask non-specific sorption sites for Cs and are applied to a number of different soils and pure minerals. Measurement of the FES capacity of pure illite is straightforward. It is shown that the measured capacity is independent of the saturating ion, but does depend on particle size. This method could not be successfully applied to a peat bog soil with 90% organic matter, because the necessary correction for non-specific Cs sorption by the large pool of organic exchange sites overpasses the capacity of the small FES fraction. Measurement of the combined parameter K{sub D}{sup C}s x [K{sup +}] is shown to be more appropriate in such cases. Application of the FES capacity method to the hydrous aluminosilicate mineral allophane, an important soil constituent of Andisols, shows that the AgTU-complex is unable to block all non-specific sorption sites for Cs on this mineral. The K{sub D}{sup C}s x [K{sup +}] measurements show evidence of a very small number of specific Cs sorption sites on allophane, much smaller than inferred from the FES capacity measurement. The FES capacity of the clay mineral vermiculite is difficult to quantify because the high Cs concentrations that are needed to measure the FES capacity probably cause a collapse of the vermiculite interlayers, thereby creating more high-affinity sites for Cs. The K{sub D}{sup C}s x [K{sup +}] method, in which only trace concentrations of Cs are used, is shown to be more appropriate for soils

  4. Using heat demand prediction to optimise Virtual Power Plant production capacity

    NARCIS (Netherlands)

    Bakker, Vincent; Molderink, Albert; Hurink, Johann L.; Smit, Gerardus Johannes Maria

    2008-01-01

    In the coming decade a strong trend towards distributed electricity generation (microgeneration) is expected. Micro-generators are small appliances that generate electricity (and heat) at the kilowatt level, which allows them to be installed in households. By combining a group of micro-generators, a

  5. Small heat-shock proteins and leaf cooling capacity account for the unusual heat tolerance of the central spike leaves in Agave tequilana var. Weber.

    Science.gov (United States)

    Luján, Rosario; Lledías, Fernando; Martínez, Luz María; Barreto, Rita; Cassab, Gladys I; Nieto-Sotelo, Jorge

    2009-12-01

    Agaves are perennial crassulacean acid metabolism (CAM) plants distributed in tropical and subtropical arid environments, features that are attractive for studying the heat-shock response. In agaves, the stress response can be analysed easily during leaf development, as they form a spirally shaped rosette, having the meristem surrounded by folded leaves in the centre (spike) and the unfolded and more mature leaves in the periphery. Here, we report that the spike of Agave tequilana is the most thermotolerant part of the rosette withstanding shocks of up to 55 degrees C. This finding was inconsistent with the patterns of heat-shock protein (Hsp) gene expression, as maximal accumulation of Hsp transcripts was at 44 degrees C in all sectors (spike, inner, middle and outer). However, levels of small HSP (sHSP)-CI and sHSP-CII proteins were conspicuously higher in spike leaves at all temperatures correlating with their thermotolerance. In addition, spike leaves showed a higher stomatal density and abated more efficiently their temperature several degrees below that of air. We propose that the greater capacity for leaf cooling during the day in response to heat stress, and the elevated levels of sHSPs, constitute part of a set of strategies that protect the SAM and folded leaves of A. tequilana from high temperatures.

  6. Estimations of isoprenoid emission capacity from enclosure studies: measurements, data processing, quality and standardized measurement protocols

    Directory of Open Access Journals (Sweden)

    Ü. Niinemets

    2011-08-01

    Full Text Available The capacity for volatile isoprenoid production under standardized environmental conditions at a certain time (ES, the emission factor is a key characteristic in constructing isoprenoid emission inventories. However, there is large variation in published ES estimates for any given species partly driven by dynamic modifications in ES due to acclimation and stress responses. Here we review additional sources of variation in ES estimates that are due to measurement and analytical techniques and calculation and averaging procedures, and demonstrate that estimations of ES critically depend on applied experimental protocols and on data processing and reporting. A great variety of experimental setups has been used in the past, contributing to study-to-study variations in ES estimates. We suggest that past experimental data should be distributed into broad quality classes depending on whether the data can or cannot be considered quantitative based on rigorous experimental standards. Apart from analytical issues, the accuracy of ES values is strongly driven by extrapolation and integration errors introduced during data processing. Additional sources of error, especially in meta-database construction, can further arise from inconsistent use of units and expression bases of ES. We propose a standardized experimental protocol for BVOC estimations and highlight basic meta-information that we strongly recommend to report with any ES measurement. We conclude that standardization of experimental and calculation protocols and critical examination of past reports is essential for development of accurate emission factor databases.

  7. Development of a water boil-off spent-fuel calorimeter system. [To measure decay heat generation rate

    Energy Technology Data Exchange (ETDEWEB)

    Creer, J.M.; Shupe, J.W. Jr.

    1981-05-01

    A calorimeter system was developed to measure decay heat generation rates of unmodified spent fuel assemblies from commercial nuclear reactors. The system was designed, fabricated, and successfully tested using the following specifications: capacity of one BWR or PWR spent fuel assembly; decay heat generation range 0.1 to 2.5 kW; measurement time of < 12 h; and an accuracy of +-10% or better. The system was acceptance tested using a dc reference heater to simulate spent fuel assembly heat generation rates. Results of these tests indicated that the system could be used to measure heat generation rates between 0.5 and 2.5 kW within +- 5%. Measurements of heat generation rates of approx. 0.1 kW were obtained within +- 15%. The calorimeter system has the potential to permit measurements of heat generation rates of spent fuel assemblies and other devices in the 12- to 14-kW range. Results of calorimetry of a Turkey Point spent fuel assembly indicated that the assembly was generating approx. 1.55 kW.

  8. Developing an Instrument to Measure Autonomous Adaptive Capacity to Climate Change among Urban Households

    Directory of Open Access Journals (Sweden)

    Kathryn R. Selm

    2018-02-01

    Full Text Available The capacity of households in urban environments to adapt and react to climate change can affect the resilience of the whole community, and instruments for systematically measuring that capacity are needed. We used Raleigh, NC as a case study to explore the dimensions of autonomous adaptive capacity of urban households and to create a scale and associated survey instrument to measure them. Our approach was guided by four capitals that support human livelihoods: social, human, physical, and financial. We surveyed 200 households in Raleigh, NC, and used a principal components analysis to test the scale and survey instrument. Results suggest the scale is a useful and concise tool. Three major dimensions were present among the scale items: financial capital, political awareness, and access to resources. Together, these three dimensions can be used to measure adaptive capacity among different households. These findings are supported by similar work illustrating the value of income inequality and political awareness as indicators of adaptive capacity. Our results also demonstrate that complex relationships among the livelihood capitals may confound our ability to measure financial, physical, and human capitals separately. This framework for assessing adaptive capacity of households, with further refinement and testing, may be used in urban areas to evaluate programs designed to impact resilience to climate change.

  9. [Measuring, evaluating and strategic development of community capacity and empowerment: introduction of a qualitative tool].

    Science.gov (United States)

    Laverack, G

    2008-12-01

    This article addresses the questions of why some communities have more ability than others, why some communities are more capable at accessing resources, at influencing decision makers, are better organised and are better able at mobilising themselves towards empowerment. The difference in ability can be attributed to the level of knowledge, skills and competencies or capacity that a community has and which it can draw upon to address its concerns about the lives and health of its members. This article discusses a qualitative tool that has been extensively used in health promotion programmes to build community capacity and empowerment. The article defines the key concepts and unpacks capacity building into nine specific 'domains'. The article goes on to describe how the 'tool' can be implemented by practitioners to build and measure capacity and empowerment. The article provides an actual example from practice on the use of an innovative form of visual representation of the findings of the measurement.

  10. Analysis of the Storage Capacity in an Aggregated Heat Pump Portfolio

    DEFF Research Database (Denmark)

    Nielsen, Kirsten Mølgaard; Andersen, Palle; Pedersen, Tom Søndergård

    2015-01-01

    to suitable time slots and this makes it possible to avoid some grid storage capacity. The energy is bought based on prediction of energy prices, weather forecast and an aggregated house model on the NORD POOL day-ahead market. The bought energy is then distributed to the houses using a model free sorting...... (scheduling) algorithm. The properties of this scheduling are investigated in the paper especially the flexibility and ability to trade on the intra-day regulating market is in focus....

  11. Molecular simulation of caloric properties of fluids modelled by force fields with intramolecular contributions: Application to heat capacities.

    Science.gov (United States)

    Smith, William R; Jirsák, Jan; Nezbeda, Ivo; Qi, Weikai

    2017-07-21

    The calculation of caloric properties such as heat capacity, Joule-Thomson coefficients, and the speed of sound by classical force-field-based molecular simulation methodology has received scant attention in the literature, particularly for systems composed of complex molecules whose force fields (FFs) are characterized by a combination of intramolecular and intermolecular terms. The calculation of a thermodynamic property for a system whose molecules are described by such a FF involves the calculation of the residual property prior to its addition to the corresponding ideal-gas property, the latter of which is separately calculated, either using thermochemical compilations or nowadays accurate quantum mechanical calculations. Although the simulation of a volumetric residual property proceeds by simply replacing the intermolecular FF in the rigid molecule case by the total (intramolecular plus intermolecular) FF, this is not the case for a caloric property. We describe the correct methodology required to perform such calculations and illustrate it in this paper for the case of the internal energy and the enthalpy and their corresponding molar heat capacities. We provide numerical results for c P , one of the most important caloric properties. We also consider approximations to the correct calculation procedure previously used in the literature and illustrate their consequences for the examples of the relatively simple molecule 2-propanol, CH 3 CH(OH)CH 3 , and for the more complex molecule monoethanolamine, HO(CH 2 ) 2 NH 2 , an important fluid used in carbon capture.

  12. Carbohydrate ingestion and pre-cooling improves exercise capacity following soccer-specific intermittent exercise performed in the heat.

    Science.gov (United States)

    Clarke, N D; Maclaren, D P M; Reilly, T; Drust, B

    2011-07-01

    Ingestion of carbohydrate and reducing core body temperature pre-exercise, either separately or combined, may have ergogenic effects during prolonged intermittent exercise in hot conditions. The aim of this investigation was to examine the effect of carbohydrate ingestion and pre-cooling on the physiological responses to soccer-specific intermittent exercise and the impact on subsequent high-intensity exercise performance in the heat. Twelve male soccer players performed a soccer-specific intermittent protocol for 90 min in the heat (30.5°C and 42.2% r.h.) on four occasions. On two occasions, the participants underwent a pre-cooling manoeuvre. During these sessions either a carbohydrate-electrolyte solution (CHOc) or a placebo was consumed at (PLAc). During the remaining sessions either the carbohydrate-electrolyte solution (CHO) or placebo (PLA) was consumed. At 15-min intervals throughout the protocol participants performed a mental concentration test. Following the soccer-specific protocol participants performed a self-chosen pace test and a test of high-intensity exercise capacity. The period of pre-cooling significantly reduced core temperature, muscle temperature and thermal sensation (P carbohydrate during exercise enhances exercise capacity and helps maintain mental performance during intermittent exercise in hot conditions.

  13. Molecular simulation of caloric properties of fluids modelled by force fields with intramolecular contributions: Application to heat capacities

    Science.gov (United States)

    Smith, William R.; Jirsák, Jan; Nezbeda, Ivo; Qi, Weikai

    2017-07-01

    The calculation of caloric properties such as heat capacity, Joule-Thomson coefficients, and the speed of sound by classical force-field-based molecular simulation methodology has received scant attention in the literature, particularly for systems composed of complex molecules whose force fields (FFs) are characterized by a combination of intramolecular and intermolecular terms. The calculation of a thermodynamic property for a system whose molecules are described by such a FF involves the calculation of the residual property prior to its addition to the corresponding ideal-gas property, the latter of which is separately calculated, either using thermochemical compilations or nowadays accurate quantum mechanical calculations. Although the simulation of a volumetric residual property proceeds by simply replacing the intermolecular FF in the rigid molecule case by the total (intramolecular plus intermolecular) FF, this is not the case for a caloric property. We describe the correct methodology required to perform such calculations and illustrate it in this paper for the case of the internal energy and the enthalpy and their corresponding molar heat capacities. We provide numerical results for cP, one of the most important caloric properties. We also consider approximations to the correct calculation procedure previously used in the literature and illustrate their consequences for the examples of the relatively simple molecule 2-propanol, CH3CH(OH)CH3, and for the more complex molecule monoethanolamine, HO(CH2)2NH2, an important fluid used in carbon capture.

  14. Heat capacity peak at the quantum critical point of the transverse Ising magnet CoNb2O6.

    Science.gov (United States)

    Liang, Tian; Koohpayeh, S M; Krizan, J W; McQueen, T M; Cava, R J; Ong, N P

    2015-07-06

    The transverse Ising magnet Hamiltonian describing the Ising chain in a transverse magnetic field is the archetypal example of a system that undergoes a transition at a quantum critical point (QCP). The columbite CoNb2O6 is the closest realization of the transverse Ising magnet found to date. At low temperatures, neutron diffraction has observed a set of discrete collective spin modes near the QCP. Here, we ask if there are low-lying spin excitations distinct from these relatively high-energy modes. Using the heat capacity, we show that a significant band of gapless spin excitations exists. At the QCP, their spin entropy rises to a prominent peak that accounts for 30% of the total spin degrees of freedom. In a narrow field interval below the QCP, the gapless excitations display a fermion-like, temperature-linear heat capacity below 1 K. These novel gapless modes are the main spin excitations participating in, and affected by, the quantum transition.

  15. Calibration of a low temperature calorimeter and application in the determination of isobaric heat capacity of 2-propanol

    Energy Technology Data Exchange (ETDEWEB)

    Casas, L.M., E-mail: lmcasas@uvigo.es [Departamento de Fisica Aplicada, Facultade de Ciencias Experimentais, Universidade de Vigo, Lagoas Marcosende s/n, 36310 Vigo (Spain); Plantier, F. [Laboratoire de Thermodynamique et Energetique des Fluides Complexes - UMR 5150, Universite de Pau et des Pays de l' Adour, BP 1155, 64013 Pau (France); Pineiro, M.M.; Legido, J.L. [Departamento de Fisica Aplicada, Facultade de Ciencias Experimentais, Universidade de Vigo, Lagoas Marcosende s/n, 36310 Vigo (Spain); Bessieres, D. [Laboratoire de Thermodynamique et Energetique des Fluides Complexes - UMR 5150, Universite de Pau et des Pays de l' Adour, BP 1155, 64013 Pau (France)

    2010-08-10

    Nowadays, the experimental thermodynamic characterization of solvents in an extended range of temperatures and pressures is essential for the development of a wide variety of industrial applications (refrigeration, reactors, pumping, etc.). Moreover, accurate experimental data are also the key for the successful development and subsequent benchmarking of thermodynamic theoretical models. In the particular case of isobaric heat capacities, there are quite a lot of reported experimental high temperature data but, on the other hand, low temperature data are practically inexistent for most compounds. Bearing this limitation in mind, the present work is focused on the development of a new calibration methodology for calorimetric determination of isobaric heat capacities in liquid state at low temperatures. For this purpose, a Calvet calorimeter, SETARAM BT 2.15 has been used. By means of the calibration procedure explained below, this calorimeter allows to determine phase transitions and thermodynamic properties in a wide range of temperature (233.15-473.15 K) and pressure (0.1-100 MPa).

  16. Responses to dry heat of men and women with similar aerobic capacities.

    Science.gov (United States)

    Frye, A J; Kamon, E

    1981-01-01

    Four men and four women with similar VO2max (56.33 +/- 4.05 and 54.08 +/- 4.27 ml.kg-1.min-1, respectively) exercised up to 3 h at 30% VO2max during heat stress tests (HST) before and after acclimation to dry heat [dry-bulb temperature (Tdb)/wet-bulb temperature (Twb) = 48/25 degrees C]. Rectal (Tre), tympanic sweat on the chest (msw), and total sweat rate (Msw) were recorded. There were no differences in the responses of the women between phases of the menstrual cycle. Tre, Tty, Tsk, and Tdb at the onset of sweating were similar in both sexes before and after acclimation. The nonacclimated men had significantly higher Msw and slower rise in Tre as compared to the nonacclimated women. Following acclimation these differences were no longer evident. Acclimation produced an increase in Msw in both sexes that was characterized by an increase in sweating sensitivity (delta msw/delta Tre). It was concluded that sex alone does not determine responses to heat stress. Consideration should also be given to the relative cardiovascular strain, state of acclimation, and the ambient conditions.

  17. Direct measuring of heat flows from interior part of the Earth in boreholes

    Energy Technology Data Exchange (ETDEWEB)

    Kutas, R.I.; Bervzyuk, M.I.; Gerashchenko, O.A.; Grishchenko, T.G.

    1977-01-01

    The borehole equipment is described for combined measuring of temperature and heat flow. Temperatures are measured with thermoresistor and heat flow sensor. Results of examinations are presented for several regions of the Ukr.SSR territory.

  18. Temperature measurement methods during direct heat arterial tissue fusion.

    Science.gov (United States)

    Cezo, James D; Kramer, Eric; Taylor, Kenneth D; Ferguson, Virginia; Rentschler, Mark E

    2013-09-01

    Fusion of biological tissues through direct and indirect heating is a growing area of medical research, yet there are still major gaps in understanding this procedure. Several companies have developed devices which fuse blood vessels, but little is known about the tissue's response to the stimuli. The need for accurate measurements of tissue behavior during tissue fusion is essential for the continued development and improvement of energy delivery devices. An experimental study was performed to measure the temperatures experienced during tissue fusion and the resulting burst pressure of the fused arteries. An array of thermocouples was placed in the lumen of a porcine splenic artery segment and sealed using a ConMed Altrus thermal fusion device. The temperatures within the tissue, in the device, and at the tissue-device interface were recorded. These measurements were then analyzed to calculate the temperature profile in the lumen of the artery. The temperature in the artery at the site of tissue fusion was measured to range from 142 to 163 °C using the ConMed Altrus. The corresponding burst pressure for arteries fused at this temperature was measured as 416 ± 79 mmHg. This study represents the first known experimental measurement of temperature at the site of vessel sealing found in the literature.

  19. Stable water isotope and surface heat flux simulation using ISOLSM: Evaluation against in-situ measurements

    KAUST Repository

    Cai, Mick Y.

    2015-04-01

    The stable isotopes of water are useful tracers of water sources and hydrological processes. Stable water isotope-enabled land surface modeling is a relatively new approach for characterizing the hydrological cycle, providing spatial and temporal variability for a number of hydrological processes. At the land surface, the integration of stable water isotopes with other meteorological measurements can assist in constraining surface heat flux estimates and discriminate between evaporation (E) and transpiration (T). However, research in this area has traditionally been limited by a lack of continuous in-situ isotopic observations. Here, the National Centre for Atmospheric Research stable isotope-enabled Land Surface Model (ISOLSM) is used to simulate the water and energy fluxes and stable water isotope variations. The model was run for a period of one month with meteorological data collected from a coastal sub-tropical site near Sydney, Australia. The modeled energy fluxes (latent heat and sensible heat) agreed reasonably well with eddy covariance observations, indicating that ISOLSM has the capacity to reproduce observed flux behavior. Comparison of modeled isotopic compositions of evapotranspiration (ET) against in-situ Fourier Transform Infrared spectroscopy (FTIR) measured bulk water vapor isotopic data (10. m above the ground), however, showed differences in magnitude and temporal patterns. The disparity is due to a small contribution from local ET fluxes to atmospheric boundary layer water vapor (~1% based on calculations using ideal gas law) relative to that advected from the ocean for this particular site. Using ISOLSM simulation, the ET was partitioned into E and T with 70% being T. We also identified that soil water from different soil layers affected T and E differently based on the simulated soil isotopic patterns, which reflects the internal working of ISOLSM. These results highlighted the capacity of using the isotope-enabled models to discriminate

  20. Dynamic Measurement Modeling: Using Nonlinear Growth Models to Estimate Student Learning Capacity

    Science.gov (United States)

    Dumas, Denis G.; McNeish, Daniel M.

    2017-01-01

    Single-timepoint educational measurement practices are capable of assessing student ability at the time of testing but are not designed to be informative of student capacity for developing in any particular academic domain, despite commonly being used in such a manner. For this reason, such measurement practice systematically underestimates the…

  1. Measuring practice capacity for change: a tool for guiding quality improvement in primary care settings.

    Science.gov (United States)

    Bobiak, Sarah N; Zyzanski, Stephen J; Ruhe, Mary C; Carter, Caroline A; Ragan, Brian; Flocke, Susan A; Litaker, David; Stange, Kurt C

    2009-01-01

    Capacity for change, or the ability and willingness to undertake change, is an organizational characteristic with potential to foster quality management in health care. We report on the development and psychometric properties of a quantitative measure of capacity for change for use in primary care settings. Following review of previous conceptual and empirical studies, we generated 117 items that assessed organizational structure, climate, and culture. Using information from direct observation and key informant interviews, a research team member rated these items for 15 primary care practices engaged in a quality improvement intervention. Distributional statistics, pairwise correlation analysis, Rasch modeling, and item content review guided item reduction and instrument finalization. Reliability and convergent validity were assessed. Ninety-two items were removed because of limited response distributions and redundancy or because of poor Rasch model fit. The final instrument comprising 25 items had excellent reliability (alpha = .94). A Rasch model-derived capacity for change score correlated well with an independently determined, qualitatively derived summary assessment of each practice's capacity for change (rhoS = 0.82), suggesting good convergent validity. We describe a new instrument for quantifying organizational capacity for change in primary care settings. The ability to quantify capacity for change may enable better recognition of practices likely to be successful in their change efforts and those first requiring capacity building prior to change interventions.

  2. The ingestion of combined carbohydrates does not alter metabolic responses or performance capacity during soccer-specific exercise in the heat compared to ingestion of a single carbohydrate.

    Science.gov (United States)

    Clarke, N D; Campbell, I T; Drust, B; Evans, L; Reilly, T; Maclaren, D P M

    2012-01-01

    This study was designed to investigate the effect of ingesting a glucose plus fructose solution on the metabolic responses to soccer-specific exercise in the heat and the impact on subsequent exercise capacity. Eleven male soccer players performed a 90 min soccer-specific protocol on three occasions. Either 3 ml · kg(-1) body mass of a solution containing glucose (1 g · min(-1) glucose) (GLU), or glucose (0.66 g · min(-1)) plus fructose (0.33 g · min(-1)) (MIX) or placebo (PLA) was consumed every 15 minutes. Respiratory measures were undertaken at 15-min intervals, blood samples were drawn at rest, half-time and on completion of the protocol, and muscle glycogen concentration was assessed pre- and post-exercise. Following the soccer-specific protocol the Cunningham and Faulkner test was performed. No significant differences in post-exercise muscle glycogen concentration (PLA, 62.99 ± 8.39 mmol · kg wet weight(-1); GLU 68.62 ± 2.70; mmol · kg wet weight(-1) and MIX 76.63 ± 6.92 mmol · kg wet weight(-1)) or exercise capacity (PLA, 73.62 ± 8.61 s; GLU, 77.11 ± 7.17 s; MIX, 83.04 ± 9.65 s) were observed between treatments (P > 0.05). However, total carbohydrate oxidation was significantly increased during MIX compared with PLA (P carbohydrate does not influence metabolism during soccer-specific intermittent exercise or affect performance capacity after exercise in the heat.

  3. Measuring and analysing terminal capacity in East Africa: The case of the seaport of Dar es Salaam

    OpenAIRE

    Layaa, J.; Dullaert, W.

    2014-01-01

    Measuring capacity and capacity utilisation at seaport terminals is essential to ensure efficient utilisation of the infra- and superstructure of the seaport. Most of the methods that have so far been used to measure capacity utilisation are not easy to comprehend for a common seaport operator. Most of the methods are also data intensive and therefore not suited for developing countries. This article attempts to use well-known standard queuing models to measure capacity utilisation in a seapo...

  4. Towards convective heat transfer enhancement: surface modification, characterization and measurement techniques

    NARCIS (Netherlands)

    Taha, T.J.; Thakur, D.B.; van der Meer, Theodorus H.

    2012-01-01

    In this work, heat transfer surface modification and heat transfer measurement technique is developed. Heat transfer investigation was aimed to study the effect of carbon nano fibers (extremely high thermal conductive material) on the enhancement level in heat transfer. Synthesis of these carbon

  5. Measurement of cation exchange capacity (CEC) on natural zeolite by percolation method

    Science.gov (United States)

    Wiyantoko, Bayu; Rahmah, Nafisa

    2017-12-01

    The cation exchange capacity (CEC)measurement has been carried out in natural zeolite by percolation method. The natural zeolite samples used for cation exchange capacity measurement were activated beforehand with physical activation and chemical activation. The physically activated zeolite was done by calcination process at 600 °C for 4 hours. The natural zeolite was activated chemically by using sodium hydroxide by refluxing process at 60-80 °C for 3 hours. In summary, cation exchange capacity (CEC) determination was performed by percolation, distillation and titration processes. Based on the measurement that has been done, the exchange rate results from physical activated and chemical activated of natural zeolite were 181.90cmol (+)/kg and 901.49cmol (+)/kg respectively.

  6. Capturing Absorptive Capacity: Concepts, Determinants, Measurement Modes and Role in Open Innovation

    Directory of Open Access Journals (Sweden)

    Lewandowska Małgorzata Stefania

    2015-03-01

    Full Text Available Absorptive capacity (ACAP enables firm to adjust to a rapidly changing environment and achieve sustained competitive advantage. This study contributes to the existing body of knowledge on ACAP by providing a comprehensive literature review of the various conceptual attributes of the construct, its determinants, outcomes, and positive and negative consequences of using its input-oriented, output-oriented, and perceptive measurement modes. Proposals for constructing ACAP based on the Community Innovation Survey (CIS empirically illustrate for the conceptual part of the paper. Additionally, combining concepts of absorptive capacity and open innovation (which is still rare in the literature provides a new perspective on the role of absorptive capacity in opening up the innovation process. This advances the understanding of both inter-related proposals. The article also identifies key problems and formulates future research directions to improve the multi-level characteristics of absorptive capacity.

  7. Break in the Heat Capacity Change at 303 K for Complex Binding of Netropsin to AATT Containing Hairpin DNA Constructs

    Science.gov (United States)

    Freyer, Matthew W.; Buscaglia, Robert; Hollingsworth, Amy; Ramos, Joseph; Blynn, Meredith; Pratt, Rachael; Wilson, W. David; Lewis, Edwin A.

    2007-01-01

    Studies performed in our laboratory demonstrated the formation of two thermodynamically distinct complexes on binding of netropsin to a number of hairpin-forming DNA sequences containing AATT-binding regions. These two complexes were proposed to differ only by a bridging water molecule between the drug and the DNA in the lower affinity complex. A temperature-dependent isothermal titration calorimetry (ITC)-binding study was performed using one of these constructs (a 20-mer hairpin of sequence 5′-CGAATTCGTCTCCGAATTCG) and netropsin. This study demonstrated a break in the heat capacity change for the formation of the complex containing the bridging water molecule at ∼303 K. In the plot of the binding enthalpy change versus temperature, the slope (ΔCp) was −0.67 kcal mol−1 K−1 steeper after the break at 303 K. Because of the relatively low melting temperature of the 20-mer hairpin (341 K (68°C)), the enthalpy change for complex formation might have included some energy of refolding of the partially denatured hairpin, giving the suggestion of a larger ΔCp. Studies done on the binding of netropsin to similar constructs, a 24-mer and a 28-mer, with added GC basepairs in the hairpin stem to increase thermal stability, exhibit the same nonlinearity in ΔCp over the temperature range of from 275 to 333 K. The slopes (ΔCp) were −0.69 and −0.64 kcal mol−1 K−1 steeper after 303 K for the 24-mer and 28-mer, respectively. This observation strengthens the argument regarding the presence of a bridging water molecule in the lower affinity netropsin/DNA complex. The ΔCp data seem to infer that because the break in the heat capacity change function for the lower affinity binding occurs at the isoequilibrium temperature for water, water may be included or trapped in the complex. The fact that this break does not occur in the heat capacity change function for formation of the higher affinity complex can similarly be taken as evidence that water is not included in

  8. Measurement of the capacity of a freezer for active demand side management

    OpenAIRE

    Vande Meerssche, Bert; Deconinck, Geert; Van Ham, Geert

    2010-01-01

    This paper discusses the research on the buffer capacity for a domestic freezer in view of using it in an active demand side management strategy. The dynamic characteristic of a freezer has been measured by monitoring temperature and energy consumption in an acclimatised room. The measurements consider a number of parameters like filling degree, ambient temperature, setpoint of the freezer and consumer behaviour. From the measurement results a model of the freezer has been built. As a case st...

  9. Measuring and analysing terminal capacity in East Africa: the case of the port of Dar Es Salaam

    NARCIS (Netherlands)

    Layaa, J.; Dullaert, W.E.H.

    2014-01-01

    Measuring capacity and capacity utilisation at seaport terminals is essential to ensure efficient utilisation of the infra- and superstructure of the seaport. Most of the methods that have so far been used to measure capacity utilisation are not easy to comprehend for a common seaport operator. Most

  10. The Expression of Carnosine and Its Effect on the Antioxidant Capacity of Muscle in Finishing Pigs Exposed to Constant Heat Stress

    Directory of Open Access Journals (Sweden)

    Peige Yang

    2014-12-01

    Full Text Available The objective of this study was to assess the effects of constant high ambient temperatures on meat quality, antioxidant capacity, and carnosine expression in longissimus dorsi muscle of finishing pigs. Castrated 24 male DLY (crossbreeds between Landrace×Yorkshire sows and Duroc boars pigs were allocated to one of three treatments: constant ambient temperature at 22°C and ad libitum feeding (CON, n = 8; constant high ambient temperature at 30°C and ad libitum feeding (H30, n = 8; and constant ambient temperature at 22°C and pair-fed with H30 (PF, n = 8. Meat quality, malondialdehyde (MDA content, antioxidant capacity, carnosine content, and carnosine synthetase (CARNS1 mRNA expression in longissimus dorsi muscle were measured after three weeks. The results revealed that H30 had lower pH24 h, redness at 45 min, and yellowness at 24 h post-mortem (p<0.05, and higher drip loss at 48 h and lightness at 24 h post-mortem (p<0.01. Constant heat stress disrupted the pro-oxidant/antioxidant balance in longissimus dorsi muscle with higher MDA content (p<0.01 and lower antioxidant capacity (p<0.01. Carnosine content and CARNS1 mRNA expression in longissimus dorsi muscle of H30 pigs were significantly decreased (p<0.01 after three weeks at 30°C. In conclusion, constant high ambient temperatures affect meat quality and antioxidant capacity negatively, and the reduction of muscle carnosine content is one of the probable reasons.

  11. Subsampling phase retrieval for rapid thermal measurements of heated microstructures.

    Science.gov (United States)

    Taylor, Lucas N; Talghader, Joseph J

    2016-07-15

    A subsampling technique for real-time phase retrieval of high-speed thermal signals is demonstrated with heated metal lines such as those found in microelectronic interconnects. The thermal signals were produced by applying a current through aluminum resistors deposited on soda-lime-silica glass, and the resulting refractive index changes were measured using a Mach-Zehnder interferometer with a microscope objective and high-speed camera. The temperatures of the resistors were measured both by the phase-retrieval method and by monitoring the resistance of the aluminum lines. The method used to analyze the phase is at least 60× faster than the state of the art but it maintains a small spatial phase noise of 16 nm, remaining comparable to the state of the art. For slowly varying signals, the system is able to perform absolute phase measurements over time, distinguishing temperature changes as small as 2 K. With angular scanning or structured illumination improvements, the system could also perform fast thermal tomography.

  12. Measuring the heat exchange of a quantum process

    Science.gov (United States)

    Goold, John; Poschinger, Ulrich; Modi, Kavan

    2014-08-01

    Very recently, interferometric methods have been proposed to measure the full statistics of work performed on a driven quantum system [Dorner et al., Phys. Rev. Lett. 110, 230601 (2013), 10.1103/PhysRevLett.110.230601 and Mazzola et al., Phys. Rev. Lett. 110, 230602 (2013), 10.1103/PhysRevLett.110.230602]. The advantage of such schemes is that they replace the necessity to make projective measurements by performing phase estimation on an appropriately coupled ancilla qubit. These proposals are one possible route to the tangible experimental exploration of quantum thermodynamics, a subject which is the center of much current attention due to the current control of mesoscopic quantum systems. In this Rapid Communication we demonstrate that a modification of the phase estimation protocols can be used in order to measure the heat distribution of a quantum process. In addition, we demonstrate how our scheme maybe implemented using ion trap technology. Our scheme should pave the way for experimental explorations of the Landauer principle and hence the intricate energy to information conversion in mesoscopic quantum systems.

  13. First principles based group additive values for the gas phase standard entropy and heat capacity of hydrocarbons and hydrocarbon radicals.

    Science.gov (United States)

    Sabbe, Maarten K; De Vleeschouwer, Freija; Reyniers, Marie-Françoise; Waroquier, Michel; Marin, Guy B

    2008-11-27

    In this work a complete and consistent set of 95 Benson group additive values (GAVs) for standard entropies S(o) and heat capacities C(p)(o) of hydrocarbons and hydrocarbon radicals is presented. These GAVs include 46 groups, among which 25 radical groups, which, to the best of our knowledge, have not been reported before. The GAVs have been determined from a set of B3LYP/6-311G(d,p) ideal gas statistical thermodynamics values for 265 species, consistently with previously reported GAVs for standard enthalpies of formation. One-dimensional hindered rotor corrections for all internal rotations are included. The computational methodology has been compared to experimental entropies (298 K) for 39 species, with a mean absolute deviation (MAD) between experiment and calculation of 1.2 J mol(-1) K(-1), and to 46 experimental heat capacities (298 K) with a resulting MAD = 1.8 J mol(-1) K(-1). The constructed database allowed evaluation of corrections on S(o) and C(p)(o) for non-nearest-neighbor effects, which have not been determined previously. The group additive model predicts the S(o) and C(p)(o) within approximately 5 J mol(-1) K(-1) of the ab initio values for 11 of the 14 molecules of the test set, corresponding to an acceptable maximal deviation of a factor of 1.6 on the equilibrium coefficient. The obtained GAVs can be applied for the prediction of S(o) and C(p)(o) for a wide range of hydrocarbons and hydrocarbon radicals. The constructed database also allowed determination of a large set of hydrogen bond increments, which can be useful for the prediction of radical thermochemistry.

  14. Zeolite Y adsorbents with high vapor uptake capacity and robust cycling stability for potential applications in advanced adsorption heat pumps

    Energy Technology Data Exchange (ETDEWEB)

    Li, XS; Narayanan, S; Michaelis, VK; Ong, TC; Keeler, EG; Kim, H; Mckay, IS; Griffin, RG; Wang, EN

    2015-01-01

    Modular and compact adsorption heat pumps (AHPs) promise an energy-efficient alternative to conventional vapor compression based heating, ventilation and air conditioning systems. A key element in the advancement of AHPs is the development of adsorbents with high uptake capacity, fast intracrystalline diffusivity and durable hydrothermal stability. Herein, the ion exchange of NaY zeolites with ingoing Mg2+ ions is systematically studied to maximize the ion exchange degree (IED) for improved sorption performance. It is found that beyond an ion exchange threshold of 64.1%, deeper ion exchange does not benefit water uptake capacity or characteristic adsorption energy, but does enhance the vapor diffusivity. In addition to using water as an adsorbate, the uptake properties of Mg, Na-Y zeolites were investigated using 20 wt.% MeOH aqueous solution as a novel anti-freeze adsorbate, revealing that the MeOH additive has an insignificant influence on the overall sorption performance. We also demonstrated that the lab-scale synthetic scalability is robust, and that the tailored zeolites scarcely suffer from hydrothermal stability even after successive 108-fold adsorption/desorption cycles. The samples were analyzed using N-2 sorption, Al-27/Si-29 MAS NMR spectroscopy, ICP-AES, dynamic vapor sorption, SEM, Fick's 2nd law and D-R equation regressions. Among these, close examination of sorption isotherms for H2O and N-2 adsorbates allows us to decouple and extract some insightful information underlying the complex water uptake phenomena. This work shows the promising performance of our modified zeolites that can be integrated into various AHP designs for buildings, electronics, and transportation applications. (C) 2014 Elsevier Inc. All rights reserved.

  15. Electronic miniband structure, heat capacity and magnetic susceptibility of monolayer and bilayer silicene in TI, VSPM and BI regimes

    Energy Technology Data Exchange (ETDEWEB)

    Yarmohammadi, Mohsen, E-mail: m.yarmohammadi69@gmail.com

    2017-04-11

    In the current work, we theoretically study the electronic band structure (EBS), electronic heat capacity (EHC) and magnetic susceptibility (MS) of three structures including monolayer, AA-stacked and AB-stacked bilayer silicene based on the Kane–Mele Hamiltonian model and Green's function method. The particular attention of this study is paid to the effect of external electric field on the aforementioned physical properties. By variation of the electric field, three phases are found: Topological insulator (TI), valley–spin polarized metal (VSPM) and band insulator (BI). Marvellously, its electronic minibands show that the spin-up contribution of charge carriers with lowest energy bands behaves like relativistic Dirac fermions with linear (parabolic) energy dispersions in monolayer (bilayer) case near the Dirac points. An insightful analysis shows that the maximum and minimum value of EHC peak appear for (AA) AB-stacked bilayer and monolayer silicene in TI (BI) regime while in MS curves appear for (AB) AA-stacked bilayer and monolayer lattices in TI (BI) regime, respectively. Moreover, we have observed a phase transition from antiferromagnetic to ferromagnetic and paramagnetic in the monolayer and bilayer structures in the VSPM regime based on the MS findings, respectively. - Highlights: • Comparison of electronic miniband structure of monolayer and bilayer silicene by using the Kane–Mele model and Green's function technique. • Investigation and comparison the electronic contribution of heat capacity for different configurations of silicene structures. • Observation of phase transition from antiferromagnetic to ferromagnetic and paramagnetic phase in the monolayer and bilayer cases, respectively.

  16. Modified Folin-Ciocalteu antioxidant capacity assay for measuring lipophilic antioxidants.

    Science.gov (United States)

    Berker, Kadriye Isil; Ozdemir Olgun, F Ayca; Ozyurt, Dilek; Demirata, Birsen; Apak, Resat

    2013-05-22

    The Folin-Ciocalteu (FC) method of performing a total phenolics assay, originally developed for protein determination, has recently evolved as a total antioxidant capacity assay but was found to be incapable of measuring lipophilic antioxidants due to the high affinity of the FC chromophore, that is, multivalent-charged phospho-tungsto-molybdate(V), toward water. Thus, the FC method was modified and standardized so as to enable simultaneous measurement of lipophilic and hydrophilic antioxidants in NaOH-added isobutanol-water medium. Optimal conditions were as follows: dilution ratio of aqueous FC reagent with iso-BuOH (1:2, v/v), final NaOH concentration of 3.5 × 10(-2) M, reaction time of 20 min, and maximum absorption wavelength of 665 nm. The modified procedure was successfully applied to the total antioxidant capacity assay of trolox, quercetin, ascorbic acid, gallic acid, catechin, caffeic acid, ferulic acid, rosmarinic acid, glutathione, and cysteine, as well as of lipophilic antioxidants such as α-tocopherol (vitamin E), butylated hydroxyanisole, butylated hydroxytoluene, tertiary butylhydroquinone, lauryl gallate, and β-carotene. The modified FC method reliably quantified ascorbic acid, whereas the conventional method could not. The modified method was reproducible and additive in terms of total antioxidant capacity values of constituents of complex mixtures such as olive oil extract and herbal tea infusion. The trolox equivalent antioxidant capacities of the tested antioxidant compounds correlated well with those found by the Cupric Reducing Antioxidant Capacity reference method.

  17. Combined lock-in thermography and heat flow measurements for analysing heat dissipation during fatigue crack propagation

    Directory of Open Access Journals (Sweden)

    J. Bär

    2015-10-01

    Full Text Available During fatigue crack propagation experiments with constant force as well as constant stress intensity lock in thermography and heat flow measurements with a new developed peltier sensor have been performed. With lock in thermography space resolved measurements are possible and the evaluation allows to distinguish between elastic and dissipated energies. The specimens have to be coated with black paint to enhance the emissivity. The thickness of the coating influences the results and therefore quantitative measurements are problematic. The heat flow measurements are easy to perform and provide quantitative results but only integral in an area given by the used peltier element. To get comparable results the values measured with thermography were summarized in an area equivalent to that of the peltier element. The experiments with constant force show a good agreement between the thermography and the heat flow measurements. In case of the experiments with a constant stress intensity some differences become visible. Whereas the thermography measurements show a linear decrease of the signal with rising crack length, the heat flow measurements show a clearly nonlinear dependency. Obviously the measured energies in thermography and peltier based heat flow measurement are not comparable

  18. Foundation Heat Exchanger Final Report: Demonstration, Measured Performance, and Validated Model and Design Tool

    Energy Technology Data Exchange (ETDEWEB)

    Hughes, Patrick [Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States); Im, Piljae [Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)

    2012-01-01

    (FHX) has been coined to refer exclusively to ground heat exchangers installed in the overcut around the basement walls. The primary technical challenge undertaken by this project was the development and validation of energy performance models and design tools for FHX. In terms of performance modeling and design, ground heat exchangers in other construction excavations (e.g., utility trenches) are no different from conventional HGHX, and models and design tools for HGHX already exist. This project successfully developed and validated energy performance models and design tools so that FHX or hybrid FHX/HGHX systems can be engineered with confidence, enabling this technology to be applied in residential and light commercial buildings. The validated energy performance model also addresses and solves another problem, the longstanding inadequacy in the way ground-building thermal interaction is represented in building energy models, whether or not there is a ground heat exchanger nearby. Two side-by-side, three-level, unoccupied research houses with walkout basements, identical 3,700 ft{sup 2} floor plans, and hybrid FHX/HGHX systems were constructed to provide validation data sets for the energy performance model and design tool. The envelopes of both houses are very energy efficient and airtight, and the HERS ratings of the homes are 44 and 45 respectively. Both houses are mechanically ventilated with energy recovery ventilators, with space conditioning provided by water-to-air heat pumps with 2 ton nominal capacities. Separate water-to-water heat pumps with 1.5 ton nominal capacities were used for water heating. In these unoccupied research houses, human impact on energy use (hot water draw, etc.) is simulated to match the national average. At House 1 the hybrid FHX/HGHX system was installed in 300 linear feet of excavation, and 60% of that was construction excavation (needed to construct the home). At House 2 the hybrid FHX/HGHX system was installed in 360 feet of

  19. Foundation Heat Exchanger Final Report: Demonstration, Measured Performance, and Validated Model and Design Tool

    Energy Technology Data Exchange (ETDEWEB)

    Hughes, Patrick [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Im, Piljae [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2012-04-01

    (FHX) has been coined to refer exclusively to ground heat exchangers installed in the overcut around the basement walls. The primary technical challenge undertaken by this project was the development and validation of energy performance models and design tools for FHX. In terms of performance modeling and design, ground heat exchangers in other construction excavations (e.g., utility trenches) are no different from conventional HGHX, and models and design tools for HGHX already exist. This project successfully developed and validated energy performance models and design tools so that FHX or hybrid FHX/HGHX systems can be engineered with confidence, enabling this technology to be applied in residential and light commercial buildings. The validated energy performance model also addresses and solves another problem, the longstanding inadequacy in the way ground-building thermal interaction is represented in building energy models, whether or not there is a ground heat exchanger nearby. Two side-by-side, three-level, unoccupied research houses with walkout basements, identical 3,700 ft{sup 2} floor plans, and hybrid FHX/HGHX systems were constructed to provide validation data sets for the energy performance model and design tool. The envelopes of both houses are very energy efficient and airtight, and the HERS ratings of the homes are 44 and 45 respectively. Both houses are mechanically ventilated with energy recovery ventilators, with space conditioning provided by water-to-air heat pumps with 2 ton nominal capacities. Separate water-to-water heat pumps with 1.5 ton nominal capacities were used for water heating. In these unoccupied research houses, human impact on energy use (hot water draw, etc.) is simulated to match the national average. At House 1 the hybrid FHX/HGHX system was installed in 300 linear feet of excavation, and 60% of that was construction excavation (needed to construct the home). At House 2 the hybrid FHX/HGHX system was installed in 360 feet of

  20. Measuring the pollutant transport capacity of dissolved organic matter in complex matrixes

    DEFF Research Database (Denmark)

    Persson, L.; Alsberg, T.; Odham, G.

    2003-01-01

    were used and evaluated, head-space solid-phase micro-extraction (HS-SPME), enhanced solubility (ES) and fluorescence quenching (FQ). It was concluded that for samples with complex matrixes it was possible to measure the net effect of the DOM binding capacity and the salting out effect of the matrix...

  1. A Bayesian hierarchical model for the measurement of working memory capacity

    NARCIS (Netherlands)

    Morey, Richard D.

    Working memory is the memory system that allows for conscious storage and manipulation of information. The capacity of working memory is extremely limited. Measurements of this limit, and what affects it, are critical to understanding working memory. Cowan (2001) and Pashler (1988) suggested

  2. Measuring the learning capacity of organisations: development and factor analysis of the Questionnaire for Learning Organizations

    NARCIS (Netherlands)

    Oudejans, S.C.C.; Schippers, G.M.; Schramade, M.H.; Koeter, M.W.J.; van den Brink, W.

    2011-01-01

    Aims: To investigate internal consistency and factor structure of a questionnaire measuring learning capacity based on Senge's theory of the five disciplines of a learning organisation: Personal Mastery, Mental Models, Shared Vision, Team Learning, and Systems Thinking. Design: Cross-sectional

  3. Estimation of Surface Temperature and Heat Flux by Inverse Heat Transfer Methods Using Internal Temperatures Measured While Radiantly Heating a Carbon/Carbon Specimen up to 1920 F

    Science.gov (United States)

    Pizzo, Michelle; Daryabeigi, Kamran; Glass, David

    2015-01-01

    The ability to solve the heat conduction equation is needed when designing materials to be used on vehicles exposed to extremely high temperatures; e.g. vehicles used for atmospheric entry or hypersonic flight. When using test and flight data, computational methods such as finite difference schemes may be used to solve for both the direct heat conduction problem, i.e., solving between internal temperature measurements, and the inverse heat conduction problem, i.e., using the direct solution to march forward in space to the surface of the material to estimate both surface temperature and heat flux. The completed research first discusses the methods used in developing a computational code to solve both the direct and inverse heat transfer problems using one dimensional, centered, implicit finite volume schemes and one dimensional, centered, explicit space marching techniques. The developed code assumed the boundary conditions to be specified time varying temperatures and also considered temperature dependent thermal properties. The completed research then discusses the results of analyzing temperature data measured while radiantly heating a carbon/carbon specimen up to 1920 F. The temperature was measured using thermocouple (TC) plugs (small carbon/carbon material specimens) with four embedded TC plugs inserted into the larger carbon/carbon specimen. The purpose of analyzing the test data was to estimate the surface heat flux and temperature values from the internal temperature measurements using direct and inverse heat transfer methods, thus aiding in the thermal and structural design and analysis of high temperature vehicles.

  4. Assessment of Potential Capacity Increases at Combined Heat and Power Facilities Based on Available Corn Stover and Forest Logging Residues

    Directory of Open Access Journals (Sweden)

    Donald L. Grebner

    2013-08-01

    Full Text Available Combined Heat and Power (CHP production using renewable energy sources is gaining importance because of its flexibility and high-energy efficiency. Biomass materials, such as corn stover and forestry residues, are potential sources for renewable energy for CHP production. In Mississippi, approximately 4.0 MT dry tons of woody biomass is available annually for energy production. In this study, we collected and analyzed 10 years of corn stover data (2001–2010 and three years of forest logging residue data (1995, 1999, and 2002 in each county in Mississippi to determine the potential of these feed stocks for sustainable CHP energy production. We identified six counties, namely Amite, Copiah, Clarke, Wayne, Wilkinson and Rankin, that have forest logging residue feedstocks to sustain a CHP facility with a range of capacity between 8.0 and 9.8 MW. Using corn stover alone, Yazoo and Washington counties can produce 13.4 MW and 13.5 MW of energy, respectively. Considering both feedstocks and based on a conservative amount of 30% available forest logging residue and 33% corn stover, we found that 20 counties have adequate supply for a CHP facility with a capacity of 8.3 MW to 19.6 MW.

  5. Heat capacities and volumetric changes in the glass transition range: a constitutive approach based on the standard linear solid

    Science.gov (United States)

    Lion, Alexander; Mittermeier, Christoph; Johlitz, Michael

    2017-09-01

    A novel approach to represent the glass transition is proposed. It is based on a physically motivated extension of the linear viscoelastic Poynting-Thomson model. In addition to a temperature-dependent damping element and two linear springs, two thermal strain elements are introduced. In order to take the process dependence of the specific heat into account and to model its characteristic behaviour below and above the glass transition, the Helmholtz free energy contains an additional contribution which depends on the temperature history and on the current temperature. The model describes the process-dependent volumetric and caloric behaviour of glass-forming materials, and defines a functional relationship between pressure, volumetric strain, and temperature. If a model for the isochoric part of the material behaviour is already available, for example a model of finite viscoelasticity, the caloric and volumetric behaviour can be represented with the current approach. The proposed model allows computing the isobaric and isochoric heat capacities in closed form. The difference c_p -c_v is process-dependent and tends towards the classical expression in the glassy and equilibrium ranges. Simulations and theoretical studies demonstrate the physical significance of the model.

  6. Environmentally friendly and highly productive bi-component melt spinning of thermoregulated smart polymer fibres with high latent heat capacity

    Directory of Open Access Journals (Sweden)

    Ch. Cherif

    2018-03-01

    Full Text Available A stable and reproducible bi-component melt spinning process on an industrial scale incorporating Phase Change Material (PCM into textile fibres has been successfully developed and carried out using a melt spinning machine. The key factor for a successful bi-component melt spinning process is that a deep insight into the thermal and rheological behaviour of PCM using Difference Scanning Calorimetry (DSC, Thermogravimetric Analysis (TGA, and an oscillatory rheological investigation. PCM is very sensitive to the temperature and residence time of the melt spinning process. It is found that the optimal process temperature of PCM is 210 °C. The textile-physical properties and the morphology of the melt spun and further drawn bi-component core and sheath fibres (bico fibres were investigated and interpreted. The heat capacities of PCM incorporated in bico fibres were also determined by means of DSC. The melt spun bico fibres integrating PCM provide a high latent heat of up to 22 J/g, which is three times higher than that of state-of-the-art fibres, which were also obtained using the melt spinning process. Therefore, they have the potential to be used as smart polymer fibres for textile and other technical applications.

  7. Development of portable measuring system for testing of electrical vehicle's heat energy recovery system

    Science.gov (United States)

    Sarvajcz, K.; Váradiné Szarka, A.

    2016-11-01

    Nowadays the consumer society applies a huge amount of energy in many fields including transportation sector. Internal combustion vehicles contribute substantially to the air pollution. An alternative solution for reducing energy consumption is replacing the internal combustion vehicles by electrical or hybrid vehicles. Today one of the biggest disadvantages of the electrical vehicles is the finite capacity of batteries. The research topic presented in this paper is the „Energy Harvesting”, and development of energy recovery system for electrical vehicles which largely contributes in increasing the driving range. At the current phase of the research efficiency analysis of the heat energy recovery devices are investigated in real driving circumstances. Computer based mobile and wireless measurement system for the analysis was developed, tested and installed in a real vehicle. Driving tests were performed and analysed in different circumstances.

  8. Force Field Benchmark of Organic Liquids: Density, Enthalpy of Vaporization, Heat Capacities, Surface Tension, Isothermal Compressibility, Volumetric Expansion Coefficient, and Dielectric Constant

    Science.gov (United States)

    2011-01-01

    The chemical composition of small organic molecules is often very similar to amino acid side chains or the bases in nucleic acids, and hence there is no a priori reason why a molecular mechanics force field could not describe both organic liquids and biomolecules with a single parameter set. Here, we devise a benchmark for force fields in order to test the ability of existing force fields to reproduce some key properties of organic liquids, namely, the density, enthalpy of vaporization, the surface tension, the heat capacity at constant volume and pressure, the isothermal compressibility, the volumetric expansion coefficient, and the static dielectric constant. Well over 1200 experimental measurements were used for comparison to the simulations of 146 organic liquids. Novel polynomial interpolations of the dielectric constant (32 molecules), heat capacity at constant pressure (three molecules), and the isothermal compressibility (53 molecules) as a function of the temperature have been made, based on experimental data, in order to be able to compare simulation results to them. To compute the heat capacities, we applied the two phase thermodynamics method (Lin et al. J. Chem. Phys.2003, 119, 11792), which allows one to compute thermodynamic properties on the basis of the density of states as derived from the velocity autocorrelation function. The method is implemented in a new utility within the GROMACS molecular simulation package, named g_dos, and a detailed exposé of the underlying equations is presented. The purpose of this work is to establish the state of the art of two popular force fields, OPLS/AA (all-atom optimized potential for liquid simulation) and GAFF (generalized Amber force field), to find common bottlenecks, i.e., particularly difficult molecules, and to serve as a reference point for future force field development. To make for a fair playing field, all molecules were evaluated with the same parameter settings, such as thermostats and barostats

  9. The heat capacity and density of solutions of barium and tetrabutylammonium iodides in N-methylpyrrolidone at 298.15 K

    Science.gov (United States)

    Novikov, A. N.; Lenina, O. F.; Vasilev, V. A.

    2009-03-01

    The heat capacity and density of solutions of barium and tetrabutylammonium iodides in N-methylpyrrolidone (MP) were studied at 298.15 K by calorimetry and densimetry. The standard partial molar heat capacities and volumes ( overline {C_{p^2 }^ circ } and overline {V_2^ circ } ) of the electrolytes in MP were calculated. The standard heat capacities overline {C_{pi}^ circ } and volumes overline {V_i^ circ } of the Ba2+ and (C4H9)4N+ ions in solution in MP at 298.15 K were determined. With the tetrabutylammonium ion, these values were in agreement with those calculated on the basis of the tetraphenylarsonium-tetraphenyl borate and tetraphenylphosphonium-tetraphenyl borate assumptions. The results are discussed in relation to the special features of solvation in solutions of the salts studied.

  10. MEASURING THE DEVELOPMENT AND THE USE OF NATIONAL ECONOMY’S INNOVATION CAPACITY

    Directory of Open Access Journals (Sweden)

    Elena A. Nazarova

    2013-01-01

    Full Text Available The article is concerned with the problems of measuring the development and the use of national economy’s innovation capacity. It is clear that innovation capacity of the country is the basis for technical and innovative economic development, it is a strategic resource which enables to achieve competitiveness and sustainable economic growth. Effective national policies in the field of innovation-driven development, in turn, are impossible to pursue without an adequate assessment system which will be proposed in this article.

  11. Heat Load Measurements on a Large Superconducting Magnet An Application of a Void Fraction Meter

    CERN Document Server

    Pengo, R; Junker, S; Passardi, Giorgio; ten Kate, H H J

    2004-01-01

    ATLAS is one of the two major experiments of the LHC project at CERN using cryogenics. The superconducting magnet system of ATLAS is composed of the Barrel Toroid (BT), two End Caps Toroids and the Central Solenoid. The BT is formed of 8 race-track superconducting dipoles, each one 25 m long and 5 m wide. A reduced scale prototype (named B0) of one of the 8 dipoles, about one third of the length, has been constructed and tested in a dedicated cryogenic facility at CERN. To simulate the final thermal and hydraulic operating conditions, the B0 was cooled by a forced flow of 4.5 K saturated liquid helium provided by a centrifugal pump of 80 g/s nominal capacity. Both static and dynamic heat loads, generated by the induced currents on the B0 casing during a slow dump or a ramp up, have been measured to verify the expected thermal budget of the entire BT. The instrument used for the heat load measurements was a Void Fraction Meter (VFM) installed on the magnet return line. The instrument constructed at CERN was ca...

  12. Estimation of MIMO channel capacity from phase-noise impaired measurements

    DEFF Research Database (Denmark)

    Pedersen, Troels; Yin, Xuefeng; Fleury, Bernard Henri

    2008-01-01

    that phase noise of the transmitter and receiver local oscillators, when it is assumed to be a white Gaussian random process, can cause large errors of the estimated channel capacity of a low-rank MIMO channel when the standard channel matrix estimator is used. Experimental evidence shows that consecutive...... phase noise samples affecting measurement samples collected with real TDMMIMO channel sounders are correlated. In this contribution a capacity estimator that accounts for the phase noise correlation is proposed. The estimator is based on a linear minimum mean square error estimate of the MIMO channel...... matrix. It is shown by means of Monte Carlo simulations assuming a measurementbased phase noise model, that the MIMO channel capacity can be estimated accurately for signal to noise ratios up to about 35 dB...

  13. Information capacity: a measure of potential image quality of a digital camera

    Science.gov (United States)

    Cao, Frédéric; Guichard, Frédéric; Hornung, Hervé

    2010-01-01

    The aim of the paper is to define an objective measurement for evaluating the performance of a digital camera. The challenge is to mix different flaws involving geometry (as distortion or lateral chromatic aberrations), light (as luminance and color shading), or statistical phenomena (as noise). We introduce the concept of information capacity that accounts for all the main defects than can be observed in digital images, and that can be due either to the optics or to the sensor. The information capacity describes the potential of the camera to produce good images. In particular, digital processing can correct some flaws (like distortion). Our definition of information takes possible correction into account and the fact that processing can neither retrieve lost information nor create some. This paper extends some of our previous work where the information capacity was only defined for RAW sensors. The concept is extended for cameras with optical defects as distortion, lateral and longitudinal chromatic aberration or lens shading.

  14. Measuring ecosystem capacity to provide regulating services: forest removal and recovery at Hubbard Brook (USA).

    Science.gov (United States)

    Beier, Colin M; Caputo, Jesse; Groffman, Peter M

    2015-10-01

    In this study, by coupling long-term ecological data with empirical proxies of societal demand for benefits, we measured the capacity of forest watersheds to provide ecosystem services over variable time periods, to different beneficiaries, and in response to discrete perturbations and drivers of change. We revisited one of the earliest ecosystem experiments in North America: the 1963 de-vegetation of a forested catchment at Hubbard Brook Experimental Forest in New Hampshire, USA. Potential benefits of the regulation of water flow, water quality, greenhouse gases, and forest growth were compared between experimental (WS 2) and reference (WS 6) watersheds over a 30-year period. Both watersheds exhibited similarly high capacity for flow regulation, in part because functional loads remained low (i.e., few major storm events) during the de-vegetation period. Drought mitigation capacity, or the maintenance of flows sufficient to satisfy municipal water consumption, was higher in WS 2 due to reduced evapotranspiration associated with loss of plant cover. We also assessed watershed capacity to regulate flows to satisfy different beneficiaries, including hypothetical flood averse and drought averse types. Capacity to regulate water quality was severely degraded during de-vegetation, as nitrate concentrations exceeded drinking water standards on 40% of measurement days. Once forest regeneration began, WS 2 rapidly recovered the capacity to provide safe drinking water, and subsequently mitigated the eutrophication potential of rainwater at a marginally higher level than WS 6. We estimated this additional pollution removal benefit would have to accrue for approximately 65-70 years to offset the net eutrophication cost incurred during forest removal. Overall, our results affirmed the critical role of forest vegetation in water regulation, but also indicated trade-offs associated with forest removal and recovery that partially depend on larger-scale exogenous changes in climate

  15. Numerical Investigation on the Heat Extraction Capacity of Dual Horizontal Wells in Enhanced Geothermal Systems Based on the 3-D THM Model

    Directory of Open Access Journals (Sweden)

    Zhixue Sun

    2018-01-01

    Full Text Available The Enhanced Geothermal System (EGS constructs an artificial thermal reservoir by hydraulic fracturing to extract heat economically from hot dry rock. As the core element of the EGS heat recovery process, mass and heat transfer of working fluid mainly occurs in fractures. Since the direction of the natural and induced fractures are generally perpendicular to the minimum principal stress in the formation, as an effective stimulation approach, horizontal well production could increase the contact area with the thermal reservoir significantly. In this paper, the thermal reservoir is developed by a dual horizontal well system and treated as a fractured porous medium composed of matrix rock and discrete fracture network. Using the local thermal non-equilibrium theory, a coupled THM mathematical model and an ideal 3D numerical model are established for the EGS heat extraction process. EGS heat extraction capacity is evaluated in the light of thermal recovery lifespan, average outlet temperature, heat production, electricity generation, energy efficiency and thermal recovery rate. The results show that with certain reservoir and production parameters, the heat production, electricity generation and thermal recovery lifespan can achieve the commercial goal of the dual horizontal well system, but the energy efficiency and overall thermal recovery rate are still at low levels. At last, this paper puts forward a series of optimizations to improve the heat extraction capacity, including production conditions and thermal reservoir construction design.

  16. Effect of Al₂O₃ nanoparticle dispersion on the specific heat capacity of a eutectic binary nitrate salt for solar power applications

    OpenAIRE

    Hu, Y.; Y. He; Z.; Zhang; Wen, D

    2017-01-01

    Molten salts can be used as heat transfer fluids or thermal storage materials in a concentrated solar power plant. Improving the thermal properties can influence the utilization efficiency of solar energy. In this study, the effect of doping eutectic binary salt solvent with Al₂O₃ nanoparticles on its specific heat capacity (cp) was investigated. The effects of the mass fraction of nanoparticles on the cp of the composite nanofluid were analyzed, using both differential scanning calorimetry m...

  17. Heat transfer in Rockwool modelling and method of measurement. Modelling radiative heat transfer in fibrous materials

    Energy Technology Data Exchange (ETDEWEB)

    Dyrboel, Susanne

    1998-05-01

    Fibrous materials are some of the most widely used materials for thermal insulation. In this project the focus of interest has been on fibrous materials for building application. Interest in improving the thermal properties of insulation materials is increasing as legislation is being tightened to reduce the overall energy consumption. A knowledge of the individual heat transfer mechanisms - whereby heat is transferred within a particular material is an essential tool to improve continuously the thermal properties of the material. Heat is transferred in fibrous materials by four different transfer mechanisms: conduction through air, conduction through fibres, thermal radiation and convection. In a particular temperature range the conduction through air can be regarded as a constant, and conduction through fibres is an insignificant part of the total heat transfer. Radiation, however, constitutes 25-40% of the total heat transfer in light fibrous materials. In Denmark and a number of other countries convection in fibrous materials is considered as non-existent when calculating heat transmission as well as when designing building structures. Two heat transfer mechanisms have been the focus of the current project: radiation heat transfer and convection. The radiation analysis serves to develop a model that can be used in further work to gain a wider knowledge of the way in which the morphology of the fibrous material, i.e. fibre diameter distribution, fibre orientation distribution etc., influences the radiation heat transfer under different conditions. The convection investigation serves to examine whether considering convection as non-existent is a fair assumption to use in present and future building structures. The assumption applied in practically is that convection makes a notable difference only in very thick insulation, at external temperatures below -20 deg. C, and at very low densities. For lager thickness dimensions the resulting heat transfer through the

  18. Direct electronic measurement of Peltier cooling and heating in graphene

    NARCIS (Netherlands)

    Vera-Marun, I. J.; van den Berg, J. J.; Dejene, F. K.; van Wees, B. J.

    Thermoelectric effects allow the generation of electrical power from waste heat and the electrical control of cooling and heating. Remarkably, these effects are also highly sensitive to the asymmetry in the density of states around the Fermi energy and can therefore be exploited as probes of

  19. MEASUREMENT OF QUENCHING INTENSITY, CALCULATION OF HEAT TRANSFER COEFFICIENT AND GLOBAL DATABASE OF LIQUID QUENCHANTS

    Directory of Open Access Journals (Sweden)

    Božidar Liščić

    2012-02-01

    Full Text Available This paper explains the need for a database of cooling intensities for liquid quenchants, in order to predict the quench hardness, microstructure, stresses and distortion, when real engineering components of complex geometry are quenched. The existing laboratory procedures for cooling intensity evaluation, using small test specimens, and Lumped-Heat-Capacity Method for calculation of heat transfer coefficient, are presented. Temperature Gradient Method for heat transfer calculation in workshop conditions, when using the Liscic/Petrofer probe, has been elaborated. Critical heat flux densities and their relation to the initial heat flux density, is explained. Specific facilities for testing quenching intensity in workshop conditions, are shown. The two phase project of the International Federation for Heat Treatment and Surface Engineering (IFHTSE, as recently approved, is mentioned.

  20. Experimental determination of the high temperature heat capacity of a natural xenotime-(Y) solid solution and synthetic DyPO{sub 4} and ErPO{sub 4} endmembers

    Energy Technology Data Exchange (ETDEWEB)

    Gysi, Alexander P., E-mail: agysi@mines.edu [Department of Geology and Geological Engineering, Colorado School of Mines, 1516 Illinois Street, Golden, CO 80401 (United States); Harlov, Daniel [Geoforschungszentrum Potsdam (GFZ), Telegrafenberg, D-14473 Potsdam (Germany); Filho, Deusavan Costa [Department of Geology and Geological Engineering, Colorado School of Mines, 1516 Illinois Street, Golden, CO 80401 (United States); Williams-Jones, Anthony E. [Department of Earth and Planetary Sciences, McGill University, 3450 University St., Montreal, QC H3A 2A7 (Canada)

    2016-03-20

    Highlights: • A new DSC calibration method for minerals of geological interest is described. • The heat capacity of DyPO{sub 4}, ErPO{sub 4} and xenotime-(Y) were reliably determined using DSC. • The excess heat capacity of xenotime-(Y) indicates a non-ideal solution with other HREE. - Abstract: The heat capacity of natural xenotime-(Y) and synthetic DyPO{sub 4} and ErPO{sub 4} crystals was determined by differential scanning calorimetry (DSC) at temperatures of 298.15 K to 868.15 K and a pressure of 0.1 MPa. The aim of the study was to develop a method to accurately measure the isobaric heat capacity (C{sub P}) of rare earth element (REE) phosphates, compare the results to data from adiabatic calorimetric experiments, and evaluate the deviation from ideality of the C{sub P} of the natural xenotime-(Y) solid solution. The measured C{sub P} data (in J mol{sup −1} K{sup −1}) can be described by the relationships: 185.5 − 751.9T{sup −0.5} − 3.261e + 06 T{sup −2} for DyPO{sub 4}; 207.2 − 1661T{sup −0.5} − 5.289e + 05 T{sup −2} for ErPO{sub 4}; and 208 − 1241T{sup −0.5} − 2.493e + 06 T{sup −2} for xenotime-(Y); where T is the temperature in K. The heat capacity data for natural xenotime-(Y) were used to determine the excess function for the solid solution, which yields an excess heat capacity ranging between 7.9 and 10.7%, well within the range of the DSC method used in this study. The experiments indicate that xenotime-(Y) forms a non-ideal solid solution. Future DSC studies will provide important data for developing a solid solution model for the incorporation of REE in xenotime-(Y).

  1. Towards measuring the semantic capacity of a physical medium demonstrated with elementary cellular automata.

    Science.gov (United States)

    Dittrich, Peter

    2018-02-01

    The organic code concept and its operationalization by molecular codes have been introduced to study the semiotic nature of living systems. This contribution develops further the idea that the semantic capacity of a physical medium can be measured by assessing its ability to implement a code as a contingent mapping. For demonstration and evaluation, the approach is applied to a formal medium: elementary cellular automata (ECA). The semantic capacity is measured by counting the number of ways codes can be implemented. Additionally, a link to information theory is established by taking multivariate mutual information for quantifying contingency. It is shown how ECAs differ in their semantic capacities, how this is related to various ECA classifications, and how this depends on how a meaning is defined. Interestingly, if the meaning should persist for a certain while, the highest semantic capacity is found in CAs with apparently simple behavior, i.e., the fixed-point and two-cycle class. Synergy as a predictor for a CA's ability to implement codes can only be used if context implementing codes are common. For large context spaces with sparse coding contexts synergy is a weak predictor. Concluding, the approach presented here can distinguish CA-like systems with respect to their ability to implement contingent mappings. Applying this to physical systems appears straight forward and might lead to a novel physical property indicating how suitable a physical medium is to implement a semiotic system. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. [Preliminary reports of noninvasive accurate method to measure pulmonary vascular capacity in normal volunteers].

    Science.gov (United States)

    Sun, Xing-guo; Mao, Song-shou; Budoff, M J; Stringer, W W; Cheng, Xian-sheng

    2015-07-01

    Because the traditional loop of breathing control and regulation effect on blood circulation, there was rare study of pulmonary vein capacity. We need a noninvasive and accurate pulmonary vascular capacity measurement and analysis method. Twelve normal volunteers were performed a total lung CT scan, image data analysis processing by computer software, the whole lungs from the apex to the base of lung with 40-50 layers by hand-cut, the connection between adjacent layers automatically by a computer simulation, the full pulmonary vascular (≥ 0.6 mm) were treated by high-accuracy three-dimensional imaging technology after removing the interference, and then calculate the whole lung and pulmonary vascular. The whole lung of the 12 normal volunteers from the apex to the base of lung CT scan image layers was 530 ± 98 (range, 431-841). The total capacity of lung and pulmonary vascular blood was 3705 ± 857 (range, 2398-5383) ml, and the total volume of the pulmonary vascular blood was 125 ± 32 (range, 94-201) ml. The pulmonary vein vascular blood volume was 63 ± 16 (range, 47-100) ml. The method of measuring the three-dimensional imaging of pulmonary vascular capacity by analyzing lung CT scan data is available and accurate.

  3. Profiling Space Heating Behavior in Chilean Social Housing: Towards Personalization of Energy Efficiency Measures

    Directory of Open Access Journals (Sweden)

    Victor Bunster

    2015-06-01

    Full Text Available Global increases in the demand for energy are imposing strong pressures over the environment while compromising the capacity of emerging economies to achieve sustainable development. In this context, implementation of effective strategies to reduce consumption in residential buildings has become a priority concern for policy makers as minor changes at the household scale can result in major energy savings. This study aims to contribute to ongoing research on energy consumer profiling by exploring the forecasting capabilities of discrete socio-economic factors that are accessible through social housing allocation systems. Accordingly, survey data gathered by the Chilean Ministry of Social Development was used identify key characteristics that may predict firewood usage for space heating purposes among potential beneficiaries of the Chilean social housing program. The analyzed data evidences strong correlations between general household characteristics and space heating behavior in certain climatic zones, suggesting that personalized delivery of energy efficiency measures can potentially increase the effectiveness of initiatives aimed towards the reduction of current patterns of consumption.

  4. Automatic online buffer capacity (alkalinity) measurement of wastewater using an electrochemical cell.

    Science.gov (United States)

    Cheng, Liang; Charles, Wipa; Cord-Ruwisch, Ralf

    2016-10-01

    The use of an automatic online electrochemical cell (EC) for measuring the buffer capacity of wastewater is presented. pH titration curves of different solutions (NaHCO3, Na2HPO4, real municipal wastewater, and anaerobic digester liquid) were obtained by conventional chemical titration and compared to the online EC measurements. The results show that the pH titration curves from the EC were comparable to that of the conventional chemical titration. The results show a linear relationship between the response of the online EC detection system and the titrimetric partial alkalinity and total alkalinity of all tested samples. This suggests that an EC can be used as a simple online titration device for monitoring the buffer capacity of different industrial processes including wastewater treatment and anaerobic digestion processes.

  5. Evaluation of Heat Flux Measurement as a New Process Analytical Technology Monitoring Tool in Freeze Drying.

    Science.gov (United States)

    Vollrath, Ilona; Pauli, Victoria; Friess, Wolfgang; Freitag, Angelika; Hawe, Andrea; Winter, Gerhard

    2017-05-01

    This study investigates the suitability of heat flux measurement as a new technique for monitoring product temperature and critical end points during freeze drying. The heat flux sensor is tightly mounted on the shelf and measures non-invasively (no contact with the product) the heat transferred from shelf to vial. Heat flux data were compared to comparative pressure measurement, thermocouple readings, and Karl Fischer titration as current state of the art monitoring techniques. The whole freeze drying process including freezing (both by ramp freezing and controlled nucleation) and primary and secondary drying was considered. We found that direct measurement of the transferred heat enables more insights into thermodynamics of the freezing process. Furthermore, a vial heat transfer coefficient can be calculated from heat flux data, which ultimately provides a non-invasive method to monitor product temperature throughout primary drying. The end point of primary drying determined by heat flux measurements was in accordance with the one defined by thermocouples. During secondary drying, heat flux measurements could not indicate the progress of drying as monitoring the residual moisture content. In conclusion, heat flux measurements are a promising new non-invasive tool for lyophilization process monitoring and development using energy transfer as a control parameter. Copyright © 2017 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

  6. Heat Island Mitigation Measures in Response to Climate Change Impacts

    Science.gov (United States)

    Quattrochi, Dale a.; Estes, Maurice, Jr.; Crosson, William; Al-Hamdan, Mohammad

    2010-01-01

    This slide presentation examines the effect of cities, the accompanying heat island effect, and other impacts that urbanization has had on the environment. Various satellite views of several urban areas are shown.

  7. Installation Effects on Heat Transfer Measurements for a Turbine Vane

    National Research Council Canada - National Science Library

    Polanka, Marc

    2003-01-01

    ...). This turbine vane was instrumented with two types of heat flux gauges. The first was a thin film Upilex gauge design wrapped over the full airfoil surface, while the second consisted of Pyrex insert type gauges...

  8. Assessing variability in audiovisual speech integration skills using capacity and accuracy measures.

    Science.gov (United States)

    Altieri, Nicholas; Hudock, Daniel

    2014-10-01

    While most normal-hearing listeners rely on the auditory modality to obtain speech information, research has demonstrated the importance that non-auditory modalities have on language recognition during face-to-face communication. The efficient utilization of the visual modality becomes increasingly important in difficult listening conditions, and especially for older and hearing-impaired listeners with sensory or cognitive decline. First, this report will quantify audiovisual integration skills using a recently developed capacity measure that incorporates speed and accuracy. Second, to investigate sensory factors contributing to integration ability, high and low-frequency hearing thresholds will be correlated with capacity, as well as gain measures from sentence recognition. Integration scores were obtained from a within-subjects design using an open-set sentence speech recognition experiment and a closed set speeded-word classification experiment, designed to examine integration (i.e. capacity). A sample of 44 adult listeners without a self-reported history of hearing-loss was recruited. RESULTS demonstrated a significant relationship between measures of audiovisual integration and hearing thresholds. Our data indicated that a listener's ability to integrate auditory and visual speech information in the domains of speed and accuracy is associated with auditory sensory capabilities and possibly other sensory and cognitive factors.

  9. Measurement-induced operation of two-ion quantum heat machines

    Science.gov (United States)

    Chand, Suman; Biswas, Asoka

    2017-03-01

    We show how one can implement a quantum heat machine by using two interacting trapped ions, in presence of a thermal bath. The electronic states of the ions act like a working substance, while the vibrational mode is modelled as the cold bath. The heat exchange with the cold bath is mimicked by the projective measurement of the electronic states. We show how such measurement in a suitable basis can lead to either a quantum heat engine or a refrigerator, which undergoes a quantum Otto cycle. The local magnetic field is adiabatically changed during the heat cycle. The performance of the heat machine depends upon the interaction strength between the ions, the magnetic fields, and the measurement cost. In our model, the coupling to the hot and the cold baths is never switched off in an alternative fashion during the heat cycle, unlike other existing proposals of quantum heat engines. This makes our proposal experimentally realizable using current tapped-ion technology.

  10. Introduction of Differential Scanning Calorimetry in a General Chemistry Laboratory Course: Determination of Heat Capacity of Metals and Demonstration of Law of Dulong and Petit

    Science.gov (United States)

    D'Amelia, Ronald P.; Stracuzzi, Vincent; Nirode, William F.

    2008-01-01

    Today's general chemistry students are introduced to many of the principles and concepts of thermodynamics. In first-year general chemistry undergraduate courses, thermodynamic properties such as heat capacity are frequently discussed. Classical calorimetric methods of analysis and thermal equilibrium experiments are used to determine heat…

  11. The Effect of Moisture Content and Temperature on the Specific Heat Capacity of Nut and Kernel of Two Iranian Pistachio Varieties

    Directory of Open Access Journals (Sweden)

    A.R Salari Kia

    2014-04-01

    Full Text Available Pistachio has a special ranking among Iranian agricultural products. Iran is known as the largest producer and exporter of pistachio in the world. Agricultural products are imposed under different thermal treatments during storage and processing. Designing all these processes requires thermal parameters of the products such as specific heat capacity. Regarding the importance of pistachio processing as an exportable product, in this study the specific heat capacity of nut and kernel of two varieties of Iranian pistachio (Kalle-Ghochi and Badami were investigated at four levels of moisture content (initial moisture content (5%, 15%, 25% and 40% w.b. and three levels of temperature (40, 50 and 60°C. In both varieties, the differences between the data were significant at the 1% of probability; however, the effect of moisture content was greater than that of temperature. The results indicated that the specific heat capacity of both nuts and kernels increase logarithmically with increase of moisture content and also increase linearly with increase of temperature. This parameter has altered for nut and kernel of Kalle-Ghochi and Badami varieties within the range of 1.039-2.936 kJ kg-1 K-1, 1.236-3.320 kJ kg-1 K-1, 0.887-2.773 kJ kg-1 K-1 and 0.811-2.914 kJ kg-1 K-1, respectively. Moreover, for any given level of temperature, the specific heat capacity of kernels was higher than that of nuts. Finally, regression models with high R2 values were developed to predict the specific heat capacity of pistachio varieties as a function of moisture content and temperature

  12. Patient-reported measures of quality of life and functional capacity in adhesive capsulitis

    Directory of Open Access Journals (Sweden)

    Marcos Rassi Fernandes

    Full Text Available Summary Objective: To evaluate patient-reported measures of quality of life and functional capacity in adhesive capsulitis before and after suprascapular nerve block treatment; to analyze the influence of clinical and sociodemographic variables on both the outcome and correlation between the respective instruments. Method: A prospective clinical study was performed with adhesive capsulitis patients. Inclusion criteria were clinical diagnosis of adhesive capsulitis and a shoulder imaging test. The WHOQOL-BREF and DASH instruments were administered before and after treatment. A Constant test score of 55 points was used as a cutoff point for discontinuation of treatment. Mean values were compared using paired t-test and Wilcoxon. The Pearson or Spearman coefficients were used for correlation analysis. Multiple linear regression analysis was carried out using variables with p<0.20 as predictors in univariate analysis and WHOQOL domains and DASH as outcomes. The significance level was 5%. Results: Forty-three patients were evaluated. The comparison between WHOQOL-BREF and DASH mean values before and after the blocks, p<0.05. DASH correlated negatively with the physical, psychological and environmental WHOQOL-BREF domains. Older patients and those with higher levels of education influenced the improvement in patients' quality of life and functional capacity. Conclusion: The improvement of adhesive capsulitis with treatment involves an improvement in quality of life and functional capacity. The greater functional capacity of the shoulder matches a better quality of life for patients. Age and education level are the variables that most influence improvement in quality of life and functional capacity.

  13. Energy Renovation of Buildings Utilizing the U-value Meter, a New Heat Loss Measuring Device

    Directory of Open Access Journals (Sweden)

    Lars Schiøtt Sørensen

    2010-01-01

    Full Text Available A new device with the ability to measure heat loss from building facades is proposed. Yet to be commercially developed, the U-value Meter can be used as stand-alone apparatus, or in combination with thermographic-equipment. The U-value meter complements thermographs, which only reproduce surface temperature and not the heat loss distribution. There is need for a device that measures the heat loss in a quantitative manner. Convective as well as radiative heat losses are captured and measured with a five-layer thermal system. Heat losses are measured in the SI-unit W/m2K. The aim is to achieve more cost-effective building renovation, and provide a means to check the fulfillment of Building Regulation requirements with respect to stated U-values (heat transmission coefficients. In this way it should be possible to greatly reduce energy consumption of buildings.

  14. Analysis of bit-stuffing codes and lower bounds on capacity for 2-D constrained arrays using quasistationary measures

    DEFF Research Database (Denmark)

    Forchhammer, Søren

    2004-01-01

    A method for designing quasistationary probability measures for two-dimensional (2-D) constraints is presented. This measure is derived from a modified bit-stuff coding scheme and it gives the capacity of the coding scheme. This provides a constructive lower bound on the capacity of the 2-D...

  15. Effects of exercise mode and participant sex on measures of anaerobic capacity.

    Science.gov (United States)

    Hill, D W; Vingren, J L

    2014-06-01

    The purpose of this study was to compare values of maximal accumulated oxygen deficit (MAOD; a measure of anaerobic capacity) and peak post-exercise blood lactate concentration ([lactate]; a reflection of glycolytic contribution) in running and cycling, in women and men. One hundred and nineteen women and 104 men performed an exhaustive treadmill test of ~5 min duration; 106 women and 110 men performed an exhaustive cycle ergometer test of ~5 min duration. Oxygen demands for the exhaustive exercise tests were estimated by extrapolation from steady state VO2 values. For running, an upwardly curvilinear relationship between demand and speed (i.e., with demand a function of speed1.05) was used. For cycling, a linear relationship between demand and work rate was used. The MAOD was 22% higher (Panaerobic capacity in running, and explains the relatively small difference in blood [lactate] in running compared to cycling.

  16. Letter and Colour Matching Tasks: Parametric Measures of Developmental Working Memory Capacity

    Directory of Open Access Journals (Sweden)

    Tamara L. Powell

    2014-01-01

    Full Text Available We investigated the mediating role of interference in developmental assessments of working memory (WM capacity across childhood, adolescence, and young adulthood. One hundred and forty-two participants completed two versions of visuospatial (colour matching task, CMT and verbal (letter matching task, LMT WM tasks, which systematically varied cognitive load in a high and low interference condition. Results showed similar developmental trajectories across high interference contexts (CMT- and LMT-Complex and divergent developmental growth patterns across low interference contexts (CMT- and LMT-Simple. Performance on tasks requiring greater cognitive control was in closer agreement with developmental predictions relative to simple recall guided tasks that rely solely on the storage components of WM. These findings suggest that developmental WM capacity, as measured by the CMT and LMT paradigms, can be better quantified using high interference contexts, in both content domains, and demonstrate steady increases in WM through to mid-adolescence.

  17. Testing a measure of organizational learning capacity and readiness for transformational change in human services.

    Science.gov (United States)

    Bess, Kimberly D; Perkins, Douglas D; McCown, Diana L

    2011-01-01

    Transformative organizational change requires organizational learning capacity, which we define in terms of (1) internal and (2) external organizational systems alignment, and promoting a culture of learning, including (3) an emphasis on exploration and information, (4) open communication, (5) staff empowerment, and (6) support for professional development. We shortened and adapted Watkins and Marsick's Dimensions of Learning Organizations Questionnaire into a new 16-item Organizational Learning Capacity Scale (OLCS) geared more toward nonprofit organizations. The OLCS and its subscales measuring each of the above 6 dimensions are unusually reliable for their brevity. ANOVAs for the OLCS and subscales clearly and consistently confirmed extensive participant observations and other qualitative data from four nonprofit human service organizations and one local human service funding organization.

  18. Energy Renovation of Buildings Utilizing the U-value Meter, a New Heat Loss Measuring Device

    OpenAIRE

    Lars Schiøtt Sørensen

    2010-01-01

    A new device with the ability to measure heat loss from building facades is proposed. Yet to be commercially developed, the U-value Meter can be used as stand-alone apparatus, or in combination with thermographic-equipment. The U-value meter complements thermographs, which only reproduce surface temperature and not the heat loss distribution. There is need for a device that measures the heat loss in a quantitative manner. Convective as well as radiative heat losses are captured and measured w...

  19. Description of heat flux measurement methods used in hydrocarbon and propellant fuel fires at Sandia.

    Energy Technology Data Exchange (ETDEWEB)

    Nakos, James Thomas

    2010-12-01

    The purpose of this report is to describe the methods commonly used to measure heat flux in fire applications at Sandia National Laboratories in both hydrocarbon (JP-8 jet fuel, diesel fuel, etc.) and propellant fires. Because these environments are very severe, many commercially available heat flux gauges do not survive the test, so alternative methods had to be developed. Specially built sensors include 'calorimeters' that use a temperature measurement to infer heat flux by use of a model (heat balance on the sensing surface) or by using an inverse heat conduction method. These specialty-built sensors are made rugged so they will survive the environment, so are not optimally designed for ease of use or accuracy. Other methods include radiometers, co-axial thermocouples, directional flame thermometers (DFTs), Sandia 'heat flux gauges', transpiration radiometers, and transverse Seebeck coefficient heat flux gauges. Typical applications are described and pros and cons of each method are listed.

  20. Description, calibration, and preliminary testing of the coal liquefaction heat transfer coefficient measurement test unit

    Energy Technology Data Exchange (ETDEWEB)

    Mulcahey, T.P.; Lo, R.N.K.; Bump, T.R.; Mulcahey, M.E.; Fischer, J.; Cannon, T.F.; Brock, R.E.; Wilson, W.I.; Bowyer, D.

    1979-06-01

    The efficiency of energy utilization within coal-liquefaction process is of major significance to the commercialization of the process. Heat exchange equipment is also one of the major economic investments in new plants. Consequently, reliable heat transfer data are required for the economical design of heat exchange equipment. Since accurate heat transfer coefficients of coal slurries, especially with a gas phase present, cannot be accurately calculated from known physical data for the operational conditions found in the coal-liquefaction process, experimentally determined heat transfer coefficients under actual process conditions are needed. A liquefaction heat-transfer-coefficient measurement test unit for a nominal one-half-ton-per-day coal slurry was constructed, calibrated, and operated at ANL. This test unit was built to determine heat transfer coefficients needed for design of feed-heat and effluent-heat exchangers used in coal-liquefaction processes. The heat-transfer test module was substituted for the preheater and reactor used in the normal coal-liquefaction process. The heat transfer coefficient can be evaluated for the heat transfer between the three-phase feed and effluent fluids in turbulent flow and a heated or cooled stainless steel surface. A description is presented of the unit and its capabilities, calibration procedures and results, and preliminary operation and data analysis. Recommendations are made that should improve accuracy and ease of operation and data analysis of the test unit.

  1. Hemispherical total emissivity and specific heat capacity of deeply undercooled Zr41.2Ti13.8Cu12.5Ni10.0Be22.5 melts

    Science.gov (United States)

    Busch, R.; Kim, Y. J.; Johnson, W. L.; Rulison, A. J.; Rhim, W. K.; Isheim, D.

    1995-06-01

    High-temperature high-vacuum electrostatic levitation (HTHVESL) and differential scanning calorimetry (DSC) were combined to determine the hemispherical total emissivity ɛT, and the specific heat capacity cp, of the undercooled liquid and throughout the glass transition of the Zr41.2Ti13.8Cu12.5Ni10.0Be22.5 bulk metallic glass forming alloy. The ratio of cp/ɛT as a function of undercooling was determining from radiative cooling curves measured in the HTHVESL. Using specific heat capacity data obtained by DSC investigations close to the glass transition and above the melting point, ɛT and cp were separated and the specific heat capacity of the whole undercooled liquid region was determined. Furthermore, the hemispherical total emissivity of the liquid was found to be about 0.22 at 980 K. On undercooling the liquid, the emissivity decreases to approximately 0.18 at about 670 K, where the undercooled liquid starts to freeze to a glass. No significant changes of the emissivity are observed as the alloy undergoes the glass transition.

  2. Interlaboratory study of the heat capacity of LiNi{sub 1/3}Mn{sub 1/3}Co{sub 1/3}O{sub 2} (NMC111) with layered structure

    Energy Technology Data Exchange (ETDEWEB)

    Cupid, Damian M.; Gotcu, Petronela [Karlsruhe Institute of Technology (KIT), Eggenstein-Leopoldshafen (Germany). Inst. for Applied Materials - Applied Materials Physics (IAM-AWP); Beutl, Alexander [Vienna Univ. (Austria). Inst. of Inorganic Chemistry - Functional Materials; and others

    2017-11-15

    An interlaboratory study was performed to determine the heat capacity of an active material for lithium-ion batteries with layered structure and nominal composition LiNi{sub 1/3} . Mn{sub 1/3}Co{sub 1/3}O{sub 2} (NMC111). The commercial sample, which was characterized using powder X-ray diffraction and inductively coupled plasma-optical emission spectroscopy, is single phase (α-NaFeO{sub 2} crystal structure) with a composition of Li{sub 1.02}Ni{sub 0.32}Mn{sub 0.31}Co{sub 0.30}O{sub 2}. Heat capacity measurements of the homogeneous sample were performed at five laboratories using different operators, methods, devices, temperature ranges, gas atmospheres and crucible materials. The experimental procedures from each laboratory are presented and the results of the individual laboratories are analyzed. Based on a comprehensive evaluation of the data from each laboratory, the heat capacity of the NMC111 sample from 315 K to 1 020 K is obtained with an expanded reproducibility uncertainty of less than 1.22 %.

  3. Long-duration heat load measurement approach by novel apparatus design and highly efficient algorithm

    Science.gov (United States)

    Zhu, Yanwei; Yi, Fajun; Meng, Songhe; Zhuo, Lijun; Pan, Weizhen

    2017-11-01

    Improving the surface heat load measurement technique for vehicles in aerodynamic heating environments is imperative, regarding aspects of both the apparatus design and identification efficiency. A simple novel apparatus is designed for heat load identification, taking into account the lessons learned from several aerodynamic heating measurement devices. An inverse finite difference scheme (invFDM) for the apparatus is studied to identify its surface heat flux from the interior temperature measurements with high efficiency. A weighted piecewise regression filter is also proposed for temperature measurement prefiltering. Preliminary verification of the invFDM scheme and the filter is accomplished via numerical simulation experiments. Three specific pieces of apparatus have been concretely designed and fabricated using different sensing materials. The aerodynamic heating process is simulated by an inductively coupled plasma wind tunnel facility. The identification of surface temperature and heat flux from the temperature measurements is performed by invFDM. The results validate the high efficiency, reliability and feasibility of heat load measurements with different heat flux levels utilizing the designed apparatus and proposed method.

  4. The shuttle walk test: a new approach to functional walking capacity measurements for patients after stroke?

    Science.gov (United States)

    van Bloemendaal, Maijke; Kokkeler, Astrid M; van de Port, Ingrid G

    2012-01-01

    To determine the construct validity, test-retest reliability, and measurement error of the shuttle walk test (SWT) for patients after stroke. Clinimetric study. Three rehabilitation centers in the Netherlands. A sample of patients after stroke (N=75; mean age ± SD, 58.8±9.8y) who are capable of walking without physical assistance. Patients were excluded if they had sustained a subarachnoid hemorrhage or a stroke in the cerebellum or brainstem, or had any other conditions that limited their walking capacity more than the current stroke, or had sensory aphasia. Not applicable. Construct validity (6-minute walk test [6MWT]) and test-retest reliability of the SWT were assessed. Measurement error was determined with the standard error of measurement (SEM), limits of agreement, and smallest detectable differences (SDDs). Construct validity was confirmed by high significant correlations (r(p)≥.65, Pwalking distance in favor of the 6MWT. Test-retest reliability was good (intraclass correlation coefficient model 2,1 [ICC(2,1)]=.961 [.936-.977]). SEM was 6.0%, and the SDDs for individual and group were 302.0m (37%) and 38.7m (5%), respectively. The SWT is a valid and reliable measure and therefore a feasible instrument to determine functional walking capacity of patients after stroke, especially in high-speed walkers. Copyright © 2012 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  5. Gradient heat flux measurement as monitoring method for the diesel engine

    Science.gov (United States)

    Sapozhnikov, S. Z.; Mityakov, V. Yu; Mityakov, A. V.; Vintsarevich, A. V.; Pavlov, A. V.; Nalyotov, I. D.

    2017-11-01

    The usage of gradient heat flux measurement for monitoring of heat flux on combustion chamber surface and optimization of diesel work process is proposed. Heterogeneous gradient heat flux sensors can be used at various regimes for an appreciable length of time. Fuel injection timing is set by the position of the maximum point on the angular heat flux diagram however, the value itself of the heat flux may not be considered. The development of such an approach can be productive for remote monitoring of work process in the cylinders of high-power marine engines.

  6. Simultaneous measurement of aerodynamic and heat transfer data ...

    Indian Academy of Sciences (India)

    namic and the heat transfer data presented here are very valuable for the validation of CFD codes used ... Hypersonic research activities around the globe has been in major focus in recent times because of the ... dynamics (CFD) tools are increasingly being used in most aerodynamic designs even in the hypersonic flight ...

  7. A reduced core to skin temperature gradient, not a critical core temperature, affects aerobic capacity in the heat.

    Science.gov (United States)

    Cuddy, John S; Hailes, Walter S; Ruby, Brent C

    2014-07-01

    The purpose of this study was to determine the impact of the core to skin temperature gradient during incremental running to volitional fatigue across varying environmental conditions. A secondary aim was to determine if a "critical" core temperature would dictate volitional fatigue during running in the heat. 60 participants (n=49 male, n=11 female; 24±5 yrs, 177±11 cm, 75±13 kg) completed the study. Participants were uniformly stratified into a specific exercise temperature group (18 °C, 26 °C, 34 °C, or 42 °C) based on a 3-mile run performance. Participants were equipped with core and chest skin temperature sensors and a heart rate monitor, entered an environmental chamber (18 °C, 26 °C, 34 °C, or 42 °C), and rested in the seated position for 10 min before performing a walk/run to volitional exhaustion. Initial treadmill speed was 3.2 km h(-1) with a 0% grade. Every 3 min, starting with speed, speed and grade increased in an alternating pattern (speed increased by 0.805 km h(-1), grade increased by 0.5%). Time to volitional fatigue was longer for the 18 °C and 26 °C group compared to the 42 °C group, (58.1±9.3 and 62.6±6.5 min vs. 51.3±8.3 min, respectively, pskin gradient for the 18 °C and 26 °C groups was larger compared to 42 °C group (halfway: 2.6±0.7 and 2.0±0.6 vs. 1.3±0.5 for the 18 °C, 26 °C and 42 °C groups, respectively; finish: 3.3±0.7 and 3.5±1.1 vs. 2.1±0.9 for the 26 °C, 34 °C, and 42 °C groups, respectively, ptemperature and heart rate response during the exercise trials. The current data demonstrate a 13% and 22% longer run time to exhaustion for the 18 °C and 26 °C group, respectively, compared to the 42 °C group despite no differences in beginning and ending core temperatures or baseline 3-mile run time. This capacity difference appears to result from a magnified core to skin gradient via an environmental temperature advantageous to convective heat loss, and in part from an increased sweat rate. Copyright

  8. The buffer capacity and buffer systems of human whole saliva measured without loss of CO2.

    Science.gov (United States)

    Bardow, A; Moe, D; Nyvad, B; Nauntofte, B

    2000-01-01

    The buffer capacity of unstimulated (UWS) and stimulated (SWS) whole-mouth saliva involves three major buffer systems. The aim was to determine the buffer capacity of UWS and SWS at specific pH in the interval from pH 7.5 down to pH 3.0. The contribution of each of the buffer systems was also determined under conditions resembling those in the mouth. UWS and SWS were collected from 20 healthy volunteers; the saliva was collected under paraffin oil in order to avoid loss of CO2. The buffer capacity of UWS and SWS in samples with and without bicarbonate (HCO3-) and CO2 were measured at various pH by acid titration in a closed system at 36 C. The mean concentrations of the buffer systems in UWS (mean flow rate 0.55 ml/min) were 4.4 mmol/l HCO3-, 4.5 mmol/l phosphate (of which 1.3 mmol/l was present in the form of HPO4(2-)), 1876 microg/ml protein; the saliva pH was 6.8 and the P(CO2) 29.3 mmHg. The corresponding mean concentrations in SWS (mean flow rate 1.66 ml/min) were 9.7 mmol/l HCO3-, 3.8 mmol/l phosphate (of which 1.9 mmol/l was present in the form of HPO4(2-)), 1955 microg/ml protein; pH 7.2 and P(CO2) 25.7 mmHg, The highest buffer capacity of UWS and SWS was 6.0 and 8.5 mmol H+ /(1 saliva*pH unit) at pH 6.25, respectively. At saliva pH in the range from pH 7 down to pH 5, the following had significant impact on buffer capacity: the HCO3- concentration (p buffer capacity (p < 0.01).

  9. Solar Heating System with Building-Integrated Heat Storage

    DEFF Research Database (Denmark)

    Heller, Alfred

    1996-01-01

    Traditional solar heating systems cover between 5 and 10% of the heat demand fordomestic hot water and comfort heating. By applying storage capacity this share can beincreased much. The Danish producer of solar heating systems, Aidt-Miljø, markets such a system including storage of dry sand heated...... by PP-pipe heat exchanger. Heat demand is reduced due to direct solar heating, and due to storage. Heat demand is reduced due to direct solar heating, due to storage and due to lower heat losses through the ground. In theory, by running the system flow backwards through the sand storage, active heating...... can be achieved.The objective of the report is to present results from measured system evaluation andcalculations and to give guidelines for the design of such solar heating systems with building integrated sand storage. The report is aimed to non-technicians. In another report R-006 the main results...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2005-07-01

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

  11. Measurement and evaluation of percolation drainage systems capacity in real conditions

    Science.gov (United States)

    Markovic, G.; Zelenakova, M.

    2017-10-01

    The drainage system must ensure a safe disposal of the surface water without endangering the buildings and safety of people. Despite the common use of rainwater infiltration facilities, there is still only limited data available evaluating the long-term capacity of such systems especially for underground infiltration facilities. This study presents experimental measurements and evaluation of long-term infiltration efficiency in real conditions and emphasizes the importance of hydrogeological survey. The measurements of infiltration efficiency were applied to an existing percolation drainage system – infiltration shafts. Infiltration shafts were made in year 2007 so that its drainage operation takes more than 8 years. This study was started in 2011 and still continues and presents 5 years measurements of infiltration efficiency for this infiltration facility.

  12. Procedures for measuring the properties of heat-pipe wick materials

    Energy Technology Data Exchange (ETDEWEB)

    Adkins, D.R.; Dykhuizen, R.C.

    1993-07-01

    Accurate measurements of wick properties must be available to design high-performance beat pipes and to properly interpret results from heat pipe tests. In a program that is aimed at developing heat-pipe receivers for solar-Stirling electric systems, we have recently explored procedures to measure the effective pore radius and permeability of wick materials in their final ``as fabricated`` condition. Measurement techniques are compared in this paper and problems that are frequently encountered in measuring wick properties are discussed.

  13. The heat budgets of magmatic arcs: Discrepancies between heat flow measurements, volatile fluxes, and interpretations of the geologic record

    Science.gov (United States)

    Van Buer, N. J.

    2015-12-01

    Arc magmatic processes, from differentiation to emplacement, depend crucially on the rate at which heat and magma are supplied to the arc crust. In active arcs, the total heat flow can be estimated relatively directly by measuring and quantifying the amounts of heat lost via conduction, hydrothermal circulation, and eruption. This total heat flow can be used to calculate the implied magmatic flux at depth. Alternatively, magmatic flux in active arcs can be estimated from measured rates of volatile emissions, usually SO2. Unfortunately, heat flow and volatile flux data sufficiently detailed to make these calculations exist for only a handful of active arcs. In the geologic record, rates of arc magmatic flux have most frequently been estimated by measuring the preserved volumes of intrusive and extrusive products and dividing by the geochronologically determined duration of arc activity. This can be converted to heat flow by assuming a certain amount of heat carried per volume of magma. The ranges of magmatic flux estimated via either heat flow or SO2 are similar for modern arcs, but, on average, estimates from the geologic record are lower by about a factor of three (Fig. 1). This discrepancy may indicate that the assumption that preserved igneous rock volumes represent the total advective flux is a poor choice when interpreting the geologic record. Recycling of early solidified magma and loss of cumulates to the mantle may be important, i.e., the time-integrated advective flux might significantly exceed the net preserved intrusive volume. This is also supported by other lines of evidence, including geochemical mass-balance arguments, thermal models of basalt flux needed to allow substantial assimilation and/or crystal fractionation in the lower crust, high-temperature thermochronology in arcs, and thermal models of the conditions necessary to cause large, explosive eruptions from upper crustal magma chambers. Substantial recycling or convection within the arc crust

  14. Field Measurements of Heating Efficiency of Electric Forced-Air Furnaces in Six Manufactured Homes.

    Energy Technology Data Exchange (ETDEWEB)

    Davis, Bob; Palmiter, Larry S.; Siegel, Jeff

    1994-07-26

    This report presents the results of field measurements of heating efficiency for six manufactured homes in the Pacific Northwest heated with electric forced-air systems. This is the first in a series of regional and national efforts to measure in detail the heating efficiency of manufactured homes. Only six homes were included in this study because of budgetary constraints; therefore this is not a representative sample. These investigations do provide some useful information on the heating efficiency of these homes. Useful comparisons can be drawn between these study homes and site-built heating efficiencies measured with a similar protocol. The protocol used to test these homes is very similar to another Ecotope protocol used in the study conducted in 1992 and 1993 for the Bonneville Power Administration to test the heating efficiency of 24 homes. This protocol combined real-time power measurements of furnace energy usage with energy usage during co-heat periods. Accessory data such as house and duct tightness measurements and tracer gas measurements were used to describe these homes and their heating system efficiency. Ensuring that manufactured housing is constructed in an energy and resource efficient manner is of increasing concern to manufactured home builders and consumers. No comparable work has been done to measure the heating system efficiency of MCS manufactured homes, although some co-heat tests have been performed on manufactured homes heated with natural gas to validate HUD thermal standards. It is expected that later in 1994 more research of this kind will be conducted, and perhaps a less costly and less time-consuming method for testing efficiencies will be develops.

  15. Effect of pH Changes on Antioxidant Capacity and the Content of Betalain Pigments During the Heating of a Solution of Red Beet Betalains

    Directory of Open Access Journals (Sweden)

    Mikołajczyk-Bator Katarzyna

    2017-06-01

    Full Text Available Red beets and their products are mainly consumed after processing. In this study, the effect of pH on changes in antioxidant capacity (AC and the content of betalain pigments were analysed during the heating of a betalain preparation solution. With pH ranging from 4 to 9 during the heat-treatment, the content of red pigments decreased depending on the pH level of the sample. The losses of red pigments in the investigated betalain preparation solution increased along with rising pH levels of the heated solution. The greatest losses were recorded at pH of 9.0. An opposite correlation was observed for yellow pigments. The content of yellow pigments in the heated betalain preparation solution was increasing along with increasing pH. The most pronounced increase in the content of yellow pigments was found at pH of 6.5 and 7.0. At the same time, the heated betalain preparation solution was shown to exhibit a higher antioxidant capacity at pH of 6.0 (14.9 μmol Trolox/mL than at pH of 4.0 (12.6 μmol Trolox/mL. It was observed that the increase in the antioxidant capacity in heated betalain preparation solutions with pH in the 6.0–6.5 range occurred as a result of increased concentrations of neobetanin, assessed by HPLC, within the pH range from 5.0 to 6.5.

  16. Quantitative method for measuring heat flux emitted from a cryogenic object

    Science.gov (United States)

    Duncan, R.V.

    1993-03-16

    The present invention is a quantitative method for measuring the total heat flux, and of deriving the total power dissipation, of a heat-fluxing object which includes the steps of placing an electrical noise-emitting heat-fluxing object in a liquid helium bath and measuring the superfluid transition temperature of the bath. The temperature of the liquid helium bath is thereafter reduced until some measurable parameter, such as the electrical noise, exhibited by the heat-fluxing object or a temperature-dependent resistive thin film in intimate contact with the heat-fluxing object, becomes greatly reduced. The temperature of the liquid helum bath is measured at this point. The difference between the superfluid transition temperature of the liquid helium bath surrounding the heat-fluxing object, and the temperature of the liquid helium bath when the electrical noise emitted by the heat-fluxing object becomes greatly reduced, is determined. The total heat flux from the heat-fluxing object is determined as a function of this difference between these temperatures. In certain applications, the technique can be used to optimize thermal design parameters of cryogenic electronics, for example, Josephson junction and infrared sensing devices.

  17. Comprehensive assessment of geographic variation in heat tolerance and hardening capacity in populations of Drosophila melanogaster from eastern Australia

    DEFF Research Database (Denmark)

    Sgro, Carla M.; Overgaard, Johannes; Kristensen, Torsten Nygård

    2010-01-01

    We examined latitudinal variation in adult and larval heat tolerance in Drosophila melanogaster from eastern Australia. Adults were assessed using static and ramping assays. Basal and hardened static heat knockdown time showed significant linear clines; heat tolerance increased towards the tropics......, particularly for hardened flies, suggesting that tropical populations have a greater hardening response. A similar pattern was evident for ramping heat knockdown time at 0.06 degrees C min-1 increase. There was no cline for ramping heat knockdown temperature (CTmax) at 0.1 degrees C min-1 increase. Acute...

  18. Determining the Optimal Capacities of Renewable-Energy-Based Energy Conversion Systems for Meeting the Demands of Low-Energy District Heating, Electricity, and District Cooling

    DEFF Research Database (Denmark)

    Tol, Hakan; Svendsen, Svend; Dincer, Ibrahim

    2015-01-01

    This chapter presents a method for determining the optimal capacity of a renewable-energy-based energy conversion system for meeting the energy requirements of a given district as considered on a monthly basis, with use of a low-energy district heating system operating at a low temperature, as low......, and the other for the Greater Toronto Area. Various climate conditions of the case areas in question caused different observations of nominal capacities for the energy conversion systems considered with single-production and multi-production based on different renewable energy sources....

  19. Effect of variable thermal conductivity and specific heat capacity on the calculation of the critical metal hydride thickness for Ti1.1CrMn

    DEFF Research Database (Denmark)

    Mazzucco, Andrea; Rokni, Masoud

    2014-01-01

    model is applied to the metal hydride system, with Ti 1.1 CrMn as the absorbing alloy, to predict the weight fraction of absorbed hydrogen and solid bed temperat ure . Dependencies of thermal conductivity and specific heat capacity upon pressure and hydrogen content respectively , are accounted for...... with activated powder and embedded heat exchanger makes difficult to set up experimental facilities. Trustable simulation models that can address the system ́s performances to a particular design are then a funda mental step to be taken prior any experimental setup. This study considers a detailed 1D fueling...

  20. Developing SyrinOX total antioxidant capacity assay for measuring antioxidants in humans.

    Science.gov (United States)

    Prasetyo, Endry N; Knes, Otto; Nyanhongo, Gibson S; Guebitz, Georg M

    2013-02-01

    Accurate monitoring of the antioxidant status or of oxidative stress in patients is still a big challenge in clinical laboratories. This study investigates the possibility of applying a newly developed total antioxidant capacity assay method based on laccase or peroxidase oxidized syringaldazine [Tetramethoxy azobismethylene quinone (TMAMQ)] which is referred to here as SyrinOX, as a diagnostic tool for monitoring both oxidative stress and antioxidant status in patients. Attempts to adapt the Randox total antioxidant procedure [simultaneous incubation of the radical generating system (metmyoglobin and H(2) O(2) ) and antioxidant sample] for SyrinOX were abandoned after it was discovered that the H(2) O(2) reacted with enzymatically generated TMAMQ and ABTS radicals at a rate of 6.4 × 10(-2) /μM/s and 5.7 × 10(-3) /μM/s respectively. Thus this study for the first time demonstrates the negative effects of H(2) O(2) in the Randox system. This leads to erroneous results because the total antioxidant values obtained are the sum of radicals reduced by antioxidants plus those reacting with the radical generating system. Therefore they should be avoided not only for this particular method but also when using other similar methods. Consequently, SyrinOX is best applied using a three-step approach involving, production of TMAMQ, recovery and purification (free from enzyme and other impurities) and then using TMAMQ for measuring the total antioxidant capacity of samples. Using this approach, the reaction conditions for application of SyrinOX when measuring the total antioxidant capacity of plasma sample were determined to be 50% (v/v) ethanol/50 mM sodium succinate buffer pH 5.5, between 20 and 25 °C for at least 1 h. © 2012 The Authors. International Journal of Experimental Pathology © 2012 International Journal of Experimental Pathology.

  1. Development and Validation of a Kit to Measure Drink Antioxidant Capacity Using a Novel Colorimeter

    Directory of Open Access Journals (Sweden)

    Alexandros Priftis

    2016-08-01

    Full Text Available Measuring the antioxidant capacity of foods is essential, as a means of quality control to ensure that the final product reaching the consumer will be of high standards. Despite the already existing assays with which the antioxidant activity is estimated, new, faster and low cost methods are always sought. Therefore, we have developed a novel colorimeter and combined it with a slightly modified DPPH assay, thus creating a kit that can assess the antioxidant capacity of liquids (e.g., different types of coffee, beer, wine, juices in a quite fast and low cost manner. The accuracy of the colorimeter was ensured by comparing it to a fully validated Hitachi U-1900 spectrophotometer, and a coefficient was calculated to eliminate the observed differences. In addition, a new, user friendly software was developed, in order to render the procedure as easy as possible, while allowing a central monitoring of the obtained results. Overall, a novel kit was developed, with which the antioxidant activity of liquids can be measured, firstly to ensure their quality and secondly to assess the amount of antioxidants consumed with the respective food.

  2. Evaluating Moisture Control of Variable-Capacity Heat Pumps in Mechanically Ventilated, Low-Load Homes in Climate Zone 2A

    Energy Technology Data Exchange (ETDEWEB)

    Martin, Eric [University of Central Florida, Florida Solar Energy Center; Withers, Chuck [University of Central Florida, Florida Solar Energy Center; McIlvaine, Janet [University of Central Florida, Florida Solar Energy Center; Chasar, Dave [University of Central Florida, Florida Solar Energy Center; Beal, David [University of Central Florida, Florida Solar Energy Center

    2018-02-07

    The well-sealed, highly insulated building enclosures constructed by today's home building industry coupled with efficient lighting and appliances are achieving significantly reduced heating and cooling loads. These low-load homes can present a challenge when selecting appropriate space-conditioning equipment. Conventional, fixed-capacity heating and cooling equipment is often oversized for small homes, causing increased first costs and operating costs. Even if fixed-capacity equipment can be properly specified for peak loads, it remains oversized for use during much of the year. During these part-load cooling hours, oversized equipment meets the target dry-bulb temperatures very quickly, often without sufficient opportunity for moisture control. The problem becomes more acute for high-performance houses in humid climates when meeting ASHRAE Standard 62.2 recommendations for wholehouse mechanical ventilation.

  3. Effect of nanoparticles on heat capacity of nanofluids based on molten salts as PCM for thermal energy storage

    Science.gov (United States)

    Chieruzzi, Manila; Cerritelli, Gian F.; Miliozzi, Adio; Kenny, José M.

    2013-10-01

    In this study, different nanofluids with phase change behavior were developed by mixing a molten salt base fluid (selected as phase change material) with nanoparticles using the direct-synthesis method. The thermal properties of the nanofluids obtained were investigated. These nanofluids can be used in concentrating solar plants with a reduction of storage material if an improvement in the specific heat is achieved. The base salt mixture was a NaNO3-KNO3 (60:40 ratio) binary salt. The nanoparticles used were silica (SiO2), alumina (Al2O3), titania (TiO2), and a mix of silica-alumina (SiO2-Al2O3). Three weight fractions were evaluated: 0.5, 1.0, and 1.5 wt.%. Each nanofluid was prepared in water solution, sonicated, and evaporated. Measurements on thermophysical properties were performed by differential scanning calorimetry analysis and the dispersion of the nanoparticles was analyzed by scanning electron microscopy (SEM). The results obtained show that the addition of 1.0 wt.% of nanoparticles to the base salt increases the specific heat of 15% to 57% in the solid phase and of 1% to 22% in the liquid phase. In particular, this research shows that the addition of silica-alumina nanoparticles has a significant potential for enhancing the thermal storage characteristics of the NaNO3-KNO3 binary salt. These results deviated from the predictions of the theoretical model used. SEM suggests a greater interaction between these nanoparticles and the salt.

  4. Local temperature measurement in the vicinity of electromagnetically heated magnetite and gold nanoparticles

    Science.gov (United States)

    Gupta, Amit; Kane, Ravi S.; Borca-Tasciuc, Diana-Andra

    2010-09-01

    This paper describes a new technique employing fluorescent quantum dots as temperature probes for measuring the temperature rise in the proximity of nanoparticles heated by a radio frequency (rf) electromagnetic field. The remote heating of nanoparticles by an rf field is a promising approach to control biological transformations at the molecular level. In principle, the heat dissipated by each nanoparticle might produce a temperature increase in its proximity, facilitating a change in the molecules directly attached to it but not in the others. Although this method has been demonstrated to provide control over biological transformations, the proposed mechanism involves producing and maintaining large temperature differences across small distances, in the range of several degrees Celsius across tens of nanometers. Existing theories for heat generation and transfer in rf heated nanoparticle systems cannot account for these gradients. To better understand the limitations of local heating, the temperature in the vicinity of rf heated nanoparticles was measured. Dilute aqueous suspensions of gold and magnetite nanoparticles were remotely heated by an rf field between 600-800 kHz. Two systems were investigated: a control sample consisting of quantum dots mixed with nanoparticles and a solution of quantum dots covalently linked to nanoparticles. The temperature of the fluorescent probes represents the average temperature in the former and the local temperature in the later. For the experimental conditions employed in this study, the measured temperature rise in the vicinity of rf heated nanoparticles were similar to the average or "bulk" temperature, in agreement with theoretical predictions.

  5. Comparison of heat flux measurement techniques during the DIII-D metal ring campaign

    Science.gov (United States)

    Barton, J. L.; Nygren, R. E.; Unterberg, E. A.; Watkins, J. G.; Makowski, M. A.; Moser, A.; Rudakov, D. L.; Buchenauer, D.

    2017-12-01

    The heat fluxes expected in the ITER divertor raise concerns about the damage tolerances of tungsten, especially due to thermal transients caused by edge localized modes (ELMs) as well as frequent temperature cycling from high to low extremes. Therefore we are motivated to understand the heat flux conditions that can cause not only enhanced erosion but also bulk thermo-mechanical damage to a tungsten divertor. For the metal ring campaign in DIII-D, tungsten-coated TZM tile inserts were installed making two toroidal arrays of metal tile inserts in the lower divertor. This study examines the deposited heat flux on these rings with embedded thermocouples (TCs) sampling at 10 kHz and compares them to Langmuir probe (LP) and infrared thermography (IRTV) heat flux measurements. We see agreement of the TC, LP, and IRTV data within 20% of the heat flux averaged over the entire discharge, and that all three diagnostics suggest parallel heat flux at the OSP location increases linearly with input heating power. The TC and LP heat flux time traces during the discharge trend together during large changes to the average heat flux. By subtracting the LP measured inter-ELM heat flux from TC data, using a rectangular ELM energy pulse shape, and taking the relative size and duration of each ELM from {{D}}α measurements, we extract the ELM heat fluxes from TC data. This over-estimates the IRTV measured ELM heat fluxes by a factor of 1.9, and could be due to the simplicity of the TC heat flux model and the assumed ELM energy pulse shape. ELM heat fluxes deposited on the inserts are used to model tungsten erosion in this campaign. These TC ELM heat flux estimates are used in addition to IRTV, especially in cases where the IRTV view to the metal ring is obstructed. We observe that some metal inserts were deformed due to exposed leading edges. The thermal conditions on these inserts are investigated with the thermal modeling code ABAQUS using our heat flux measurements when these edges

  6. Ion association in N-methylpyrrolidone and the N-methylpyrrolidone-water mixed solvent from data on heat capacity and density of solutions

    Science.gov (United States)

    Solov'ev, S. N.; Novikov, A. N.

    2012-06-01

    Association constants for solutions of electrolytes in N-methylpyrrolidone (MP) and the MP-water mixed solvent at 298.15 K are calculated. It is shown that, over a wide range of concentrations, concentration dependences of apparent molar heat capacities and apparent molar volumes of the electrolytes in MP and MP-water mixtures are described adequately in terms of equilibria between ions and ion pairs of a single type in the solution.

  7. Surface Catalysis and Oxidation on Stagnation Point Heat Flux Measurements in High Enthalpy Arc Jets

    Science.gov (United States)

    Nawaz, Anuscheh; Driver, David M.; Terrazas-Salinas

    2013-01-01

    Heat flux sensors are routinely used in arc jet facilities to determine heat transfer rates from plasma plume. The goal of this study is to assess the impact of surface composition changes on these heat flux sensors. Surface compositions can change due to oxidation and material deposition from the arc jet. Systematic surface analyses of the sensors were conducted before and after exposure to plasma. Currently copper is commonly used as surface material. Other surface materials were studied including nickel, constantan gold, platinum and silicon dioxide. The surfaces were exposed to plasma between 0.3 seconds and 3 seconds. Surface changes due to oxidation as well as copper deposition from the arc jets were observed. Results from changes in measured heat flux as a function of surface catalycity is given, along with a first assessment of enthalpy for these measurements. The use of cupric oxide is recommended for future heat flux measurements, due to its consistent surface composition arc jets.

  8. Measures of the ovaries and uterus during development of gilts selected for differences in uterine capacity.

    Science.gov (United States)

    Lents, C A; Cushman, R A; Freking, B A

    2014-06-01

    Direct selection for uterine capacity (UC) increased the number of live pigs born. A method to indirectly estimate UC in developing gilts is needed for this trait to be incorporated into commercial selection strategies. We tested the hypothesis that selection for UC alters phenotypic characteristics of the reproductive tract of prepubertal gilts and that these changes could be estimated in live animals using transrectal ultrasound (TRU). Gilts from lines selected for UC and a randomly selected control (CO) line were submitted for TRU at 130, 150, or 170 d of age and harvested 24 h later (n = 10 gilts/line per age). Diameter of the uterine horn was measured (2 to 4 measurements per animal) at TRU. At harvest, measurements of the ovary (height, width, length, weight, and number of visible follicles >1 mm) and uterine horn (weight, length, diameter, and endometrial diameter) were taken. There was no line × age interaction for any of the traits. All ovarian traits increased (P gilts, but the number of visible follicles did not differ. The UC gilts had increased (P gilts. Diameter of the uterine horn and the endometrium were greater (P gilts than for CO gilts. Uterine horn diameter measured with TRU was not affected by age or line and was not highly correlated with any of the measured traits. Selection for increased UC results in larger ovaries and uterine horns, but TRU was not useful for estimating these traits in gilts of the age studied.

  9. Decay heat measurement on fusion reactor materials and validation of calculation code system

    Energy Technology Data Exchange (ETDEWEB)

    Maekawa, Fujio; Ikeda, Yujiro; Wada, Masayuki [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1998-03-01

    Decay heat rates for 32 fusion reactor relevant materials irradiated with 14-MeV neutrons were measured for the cooling time period between 1 minute and 400 days. With using the experimental data base, validity of decay heat calculation systems for fusion reactors were investigated. (author)

  10. Results of measurements at a laboratory condensation heat exchanger with a corrugated minichanel tube

    Directory of Open Access Journals (Sweden)

    Jan Hrubý

    2012-04-01

    Full Text Available This article present a short selection of results obtained from measurements done at a laboratory condensation heat-exchanger with a corrugated mini-channel tube. It also touches a little the metering method and design of the heat-exchanger.

  11. Ultrasound Measurements of Skeletal Muscle Architecture Are Associated with Strength and Functional Capacity in Older Adults.

    Science.gov (United States)

    Selva Raj, Isaac; Bird, Stephen R; Shield, Anthony J

    2017-03-01

    The goal of this study was to determine whether ultrasound measures of muscle architecture can be used to infer strength and functional capacity in older adults. Thirty-six healthy older adults (aged 68.2 ± 5.3 y) undertook isokinetic dynamometry for isometric and isokinetic concentric knee extensor strength, the 6-m fast walk, timed up and go, stair climb and descent and vertical jump tests. Longitudinal brightness-mode ultrasound scans (probe frequency, 10 MHz) of the vastus lateralis, vastus intermedius, rectus femoris and gastrocnemius medialis were obtained, and muscle architecture measures (thickness, fascicle pennation angle and fascicle length) were correlated with the aforementioned strength and functional measures. Quadriceps thickness was a significant (p < 0.05) independent predictor of isometric and isokinetic knee extensor strength (R 2  ≥ 0.630). Gastrocnemius medialis thickness was a significant independent predictor of 6-m fast walk test (R 2  = 0.216, p < 0.05), timed up and go test (R 2  = 0.455, p < 0.01), stair climb power (R 2  = 0.591, p < 0.01), stair descent power (R 2  = 0.608, p < 0.01) and vertical jump height (R 2  = 0.579, p < 0.01). Ultrasound is a safe, non-invasive and efficient tool for inferring the strength and functional capacity of older adults. Copyright © 2016 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

  12. Heat

    CERN Document Server

    Lawrence, Ellen

    2016-01-01

    Is it possible to make heat by rubbing your hands together? Why does an ice cube melt when you hold it? In this title, students will conduct experiments to help them understand what heat is. Kids will also investigate concepts such as which materials are good at conducting heat and which are the best insulators. Using everyday items that can easily be found around the house, students will transform into scientists as they carry out step-by-step experiments to answer interesting questions. Along the way, children will pick up important scientific skills. Heat includes seven experiments with detailed, age-appropriate instructions, surprising facts and background information, a "conclusions" section to pull all the concepts in the book together, and a glossary of science words. Colorful, dynamic designs and images truly put the FUN into FUN-damental Experiments.

  13. Tipping a SPRUCE tree over - how extreme heat and desiccation may push southern boreal species beyond their capacity

    Science.gov (United States)

    Warren, J.; Childs, J.; Ward, E. J.; Wullschleger, S.; Hanson, P. J.

    2016-12-01

    Since August 2015, the Spruce and Peatland Responses under Climatic and Environmental Change (SPRUCE) climate change experiment (http://mnspruce.ornl.gov/) in Northern Minnesota, USA, has exposed 13 m diameter plots of an ombrotrophic Picea mariana - Ericaceous shrub - Sphagnum bog ecosystem to long-term temperature (T) (0 to +9 °C) and since June 2016, elevated CO2 treatments (ambient or + 500 ppm). In addition to their direct impacts, the T and CO2 treatments have dramatically impacted soil water availability, vapor pressure deficit and # days dew point is reached. We examined plant water relations of Picea mariana (black spruce), Larix laricina (tamarack), and several Ericaceous shrubs including seasonal patterns of water potential (ψ), in addition to sap flow in the in trees. Granier-style thermal dissipation sensors were calibrated in situ (outside plots) by cutting instrumented trees and measuring their actual water uptake. Maximum summer T in N Minnesota reaches 35 °C, and optimal photosynthetic activity for P. mariana at the site peaks between 35-38°C. Treatments have resulted in air T reaching 45°C in the warmest plots resulting in substantial physiological stress. Pretreatment sap flow typically began by late May and was fairly constant over the season until declining in mid-September and ceasing as temperatures dropped below zero. Once the T treatments began, sap flow began earlier in the spring and continued later in the fall indicating an expanded physiological season that can result in plant vulnerability to extreme cold events. Indeed, foliar damage was evident in warmer plots following a spring freeze event in 2016. In addition, the drying heat has resulted in additional foliar damage, indicated by large reductions in predawn water potentials (even in the spring), quicker drying following rain events, and water stress reached earlier in the day. Midday mean summer ψ was -1.5 MPa for P. mariana foliage, higher than the co-occurring L. laricina

  14. Measuring the learning capacity of organisations: development and factor analysis of the Questionnaire for Learning Organizations.

    Science.gov (United States)

    Oudejans, S C C; Schippers, G M; Schramade, M H; Koeter, M W J; van den Brink, W

    2011-04-01

    To investigate internal consistency and factor structure of a questionnaire measuring learning capacity based on Senge's theory of the five disciplines of a learning organisation: Personal Mastery, Mental Models, Shared Vision, Team Learning, and Systems Thinking. Cross-sectional study. Substance-abuse treatment centres (SATCs) in The Netherlands. A total of 293 SATC employees from outpatient and inpatient treatment departments, financial and human resources departments. Psychometric properties of the Questionnaire for Learning Organizations (QLO), including factor structure, internal consistency, and interscale correlations. A five-factor model representing the five disciplines of Senge showed good fit. The scales for Personal Mastery, Shared Vision and Team Learning had good internal consistency, but the scales for Systems Thinking and Mental Models had low internal consistency. The proposed five-factor structure was confirmed in the QLO, which makes it a promising instrument to assess learning capacity in teams. The Systems Thinking and the Mental Models scales have to be revised. Future research should be aimed at testing criterion and discriminatory validity.

  15. Can two dots form a Gestalt? Measuring emergent features with the capacity coefficient.

    Science.gov (United States)

    Hawkins, Robert X D; Houpt, Joseph W; Eidels, Ami; Townsend, James T

    2016-09-01

    While there is widespread agreement among vision researchers on the importance of some local aspects of visual stimuli, such as hue and intensity, there is no general consensus on a full set of basic sources of information used in perceptual tasks or how they are processed. Gestalt theories place particular value on emergent features, which are based on the higher-order relationships among elements of a stimulus rather than local properties. Thus, arbitrating between different accounts of features is an important step in arbitrating between local and Gestalt theories of perception in general. In this paper, we present the capacity coefficient from Systems Factorial Technology (SFT) as a quantitative approach for formalizing and rigorously testing predictions made by local and Gestalt theories of features. As a simple, easily controlled domain for testing this approach, we focus on the local feature of location and the emergent features of Orientation and Proximity in a pair of dots. We introduce a redundant-target change detection task to compare our capacity measure on (1) trials where the configuration of the dots changed along with their location against (2) trials where the amount of local location change was exactly the same, but there was no change in the configuration. Our results, in conjunction with our modeling tools, favor the Gestalt account of emergent features. We conclude by suggesting several candidate information-processing models that incorporate emergent features, which follow from our approach. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. A survey tool for measuring evidence-based decision making capacity in public health agencies

    Directory of Open Access Journals (Sweden)

    Jacobs Julie A

    2012-03-01

    Full Text Available Abstract Background While increasing attention is placed on using evidence-based decision making (EBDM to improve public health, there is little research assessing the current EBDM capacity of the public health workforce. Public health agencies serve a wide range of populations with varying levels of resources. Our survey tool allows an individual agency to collect data that reflects its unique workforce. Methods Health department leaders and academic researchers collaboratively developed and conducted cross-sectional surveys in Kansas and Mississippi (USA to assess EBDM capacity. Surveys were delivered to state- and local-level practitioners and community partners working in chronic disease control and prevention. The core component of the surveys was adopted from a previously tested instrument and measured gaps (importance versus availability in competencies for EBDM in chronic disease. Other survey questions addressed expectations and incentives for using EBDM, self-efficacy in three EBDM skills, and estimates of EBDM within the agency. Results In both states, participants identified communication with policymakers, use of economic evaluation, and translation of research to practice as top competency gaps. Self-efficacy in developing evidence-based chronic disease control programs was lower than in finding or using data. Public health practitioners estimated that approximately two-thirds of programs in their agency were evidence-based. Mississippi participants indicated that health department leaders' expectations for the use of EBDM was approximately twice that of co-workers' expectations and that the use of EBDM could be increased with training and leadership prioritization. Conclusions The assessment of EBDM capacity in Kansas and Mississippi built upon previous nationwide findings to identify top gaps in core competencies for EBDM in chronic disease and to estimate a percentage of programs in U.S. health departments that are evidence

  17. A survey tool for measuring evidence-based decision making capacity in public health agencies.

    Science.gov (United States)

    Jacobs, Julie A; Clayton, Paula F; Dove, Cassandra; Funchess, Tanya; Jones, Ellen; Perveen, Ghazala; Skidmore, Brandon; Sutton, Victor; Worthington, Sarah; Baker, Elizabeth A; Deshpande, Anjali D; Brownson, Ross C

    2012-03-09

    While increasing attention is placed on using evidence-based decision making (EBDM) to improve public health, there is little research assessing the current EBDM capacity of the public health workforce. Public health agencies serve a wide range of populations with varying levels of resources. Our survey tool allows an individual agency to collect data that reflects its unique workforce. Health department leaders and academic researchers collaboratively developed and conducted cross-sectional surveys in Kansas and Mississippi (USA) to assess EBDM capacity. Surveys were delivered to state- and local-level practitioners and community partners working in chronic disease control and prevention. The core component of the surveys was adopted from a previously tested instrument and measured gaps (importance versus availability) in competencies for EBDM in chronic disease. Other survey questions addressed expectations and incentives for using EBDM, self-efficacy in three EBDM skills, and estimates of EBDM within the agency. In both states, participants identified communication with policymakers, use of economic evaluation, and translation of research to practice as top competency gaps. Self-efficacy in developing evidence-based chronic disease control programs was lower than in finding or using data. Public health practitioners estimated that approximately two-thirds of programs in their agency were evidence-based. Mississippi participants indicated that health department leaders' expectations for the use of EBDM was approximately twice that of co-workers' expectations and that the use of EBDM could be increased with training and leadership prioritization. The assessment of EBDM capacity in Kansas and Mississippi built upon previous nationwide findings to identify top gaps in core competencies for EBDM in chronic disease and to estimate a percentage of programs in U.S. health departments that are evidence-based. The survey can serve as a valuable tool for other health

  18. Systematic heat flow measurements across the Wagner Basin, northern Gulf of California

    Science.gov (United States)

    Neumann, Florian; Negrete-Aranda, Raquel; Harris, Robert N.; Contreras, Juan; Sclater, John G.; González-Fernández, Antonio

    2017-12-01

    A primary control on the geodynamics of rifting is the thermal regime. To better understand the geodynamics of rifting in the northern Gulf of California we systematically measured heat-flow across the Wagner Basin, a tectonically active basin that lies near the southern terminus of the Cerro Prieto fault. The heat flow profile is 40 km long, has a nominal measurement spacing of ∼1 km, and is collocated with a seismic reflection profile. Heat flow measurements were made with a 6.5-m violin-bow probe. Although heat flow data were collected in shallow water, where there are significant temporal variations in bottom water temperature, we use CTD data collected over many years to correct our measurements to yield accurate values of heat flow. After correction for bottom water temperature, the mean and standard deviation of heat flow across the western, central, and eastern parts of the basin are 220 ± 60, 99 ± 14, 889 ± 419 mW m-2, respectively. Corrections for sedimentation would increase measured heat flow across the central part of basin by 40 to 60%. We interpret the relatively high heat flow and large variability on the western and eastern flanks in terms of upward fluid flow at depth below the seafloor, whereas the lower and more consistent values across the central part of the basin are suggestive of conductive heat transfer. Moreover, heat flow across the central basin is consistent with gabbroic underplating at a depth of 15 km and suggests that continental rupture here has not gone to completion.

  19. Experimental Method for Determination of Self-Heating at the Point of Measurement

    Science.gov (United States)

    Sestan, D.; Zvizdic, D.; Grgec-Bermanec, L.

    2017-09-01

    This paper presents a new experimental method and algorithm for the determination of self-heating of platinum resistance thermometer (PRT) when the temperature instability of medium of interest would prevent an accurate self-heating determination using standard methods. In temperature measurements performed by PRT, self-heating is one of the most common sources of error and arises from the increase in sensor temperature caused by the dissipation of electrical heat when measurement current is applied to the temperature sensing element. This increase depends mainly on the applied current and the thermal resistances between thermometer sensing element and the environment surrounding the thermometer. The method is used for determination of self-heating of a 100 Ω industrial PRT which is intended for measurement of air temperature inside the saturation chamber of the primary dew/frost point generator at the Laboratory for Process Measurement (HMI/FSB-LPM). Self-heating is first determined for conditions present during the comparison calibration of the thermometer, using the calibration bath. The measurements were then repeated with thermometer being placed in an air stream inside the saturation chamber. The experiment covers the temperature range between -65°C and 10°C. Self-heating is determined for two different air velocities and two different vertical positions of PRT in relation to the chamber bottom.

  20. An Extended Framework for Measuring the Information Capacity of the Human Motor System

    CERN Document Server

    Roos, Teemu

    2011-01-01

    Fitts' law is a fundamental tool in understanding the capacity of the human motor system. It measures information throughput in terms of the tradeoff between the speed and accuracy of motor responses. Although immensely popular, the paradigm in which Fitts' law is the principal keystone is confined to relatively simple responses in strictly prescribed stimulus-response conditions. Our goal is to generalize the framework into completely unconstrained movement. The proposed new metric is based on a subject's ability to accurately reproduce a learned movement pattern. It can accommodate recorded movement of any duration and composition, and involving contributions of any part of the body. We demonstrate the proposed method by analyzing publicly available motion capture data. Possible applications include human-computer interaction, sports science, and clinical diagnosis.

  1. ELECTRIC FIELD MEASUREMENT IN ROD-DISCONTINUED PLANE AIR GAPS USING DISTRIBUTED CAPACITY PROBE

    Directory of Open Access Journals (Sweden)

    A. Khechekhouche

    2015-07-01

    Full Text Available The present experimental carried out investigations aimed at elucidating the effect of earth discontinuity on the breakdown voltage of short rod-plane air gap (80 to160 mm under negative lightning impulses (-1.2/50ms.We also carried out investigations on electric field measurement on the surface of a discontinuous plane of a rod-plane air gap arrangement. For this purpose, we used a probe with distributed capacity, under negative lightning applied impulse voltage. The probe is incorporated on the same level of plane surface.The interface locally reinforces the electric field. The electric field increases at the interface may lead to a discharge between the high voltage rode and the interface. In the vicinity of the interface, we observe a kind of discontinuity in the evolution of the electric field intensity. This one becomes greater than the value obtained in the case of gaps with homogeneous plane earth.

  2. ELECTRIC FIELD MEASUREMENT IN ROD-DISCONTINUED PLANE AIR GAPS USING DISTRIBUTED CAPACITY PROBE

    Directory of Open Access Journals (Sweden)

    A. Khechekhouche

    2014-06-01

    Full Text Available The present experimental carried out investigations aimed at elucidating the effect of earth discontinuity on the breakdown voltage of short rod-plane air gap (80 to 160 mm under negative lightning impulses (-1.2/50s. We also carried out investigations on electric field measurement on the surface of a discontinuous plane of a rod-plane air gap arrangement. For this purpose, we used a probe with distributed capacity, under negative lightning applied impulse voltage. The probe is incorporated on the same level of plane surface. The interface locally reinforces the electric field. The electric field increases at the interface may lead to a discharge between the high voltage rode and the interface. In the vicinity of the interface, we observe a kind of discontinuity in the evolution of the electric field intensity. This one becomes greater than the value obtained in the case of gaps with homogeneous plane earth.

  3. Axial offset as measure of stability of light water nuclear reactor during capacity maneuvering

    Directory of Open Access Journals (Sweden)

    Mark V. Nikolsky

    2015-03-01

    Full Text Available High reliability and security of power unit are required during operation of power unit while maneuvering. They depend on the stability of reactor when transition from one power level to another. The axial offset is a quantitative measure of the reactor stability. It is shown that change of the active core inlet coolant temperature yields an uncontrollable disturbance affecting the axial offset and therefore the reactor stability. To insure the reactor stability the compromise-combined power control method is proposed. Analysis of the influence of temperature of coolant at the magnitude of the axial offset for different regulatory programs is carried out. The change in the depth of immersion of regulators in the active zone for different regulatory programs when the reactor plant daily capacity maneuver is studied.

  4. Multiple Sclerosis Functional Composite as a Measure of the Effects of Heat in Multiple Sclerosis

    Directory of Open Access Journals (Sweden)

    Ryosa

    2016-06-01

    Full Text Available Background Heat sensitivity is a common feature of multiple sclerosis (MS, and heat has been found to impair MS patients’ physical and cognitive functioning. There is, however, no simple and specific measurement tool to evaluate the possible effects of heat on these functions. Objectives The aim of this study was to evaluate the compatibility of the multiple sclerosis functional composite (MSFC to demonstrate the effects of heat on functioning in patients with MS. Patients and Methods A total of 22 heat-sensitive MS patients and 19 healthy controls (HCs were considered for the analysis. Moderate heat exposure took place in a Finnish sauna. Functioning was measured with the MSFC, which consists of two physical (the Nine Hole Peg test and the 25-foot timed walk test and one cognitive (the PASAT-3 measure, before, during and one hour after the heat exposure. Results In the MS group the average MSFC scores were -0.48 (SD 0.79 at baseline, -0.99 (SD 1.97 during heat exposure and -0.68 (SD 1.58 after a one-hour delay. The average MSFC scores of the HC group were 0.58 (SD 0.42 at baseline, 0.66 (SD 0.43 during heat exposure and 0.68 (SD 0.41 after a one-hour delay. The MS group had significantly lower MSFC scores than the HC group (P = 0.01. The MS patients’ score deteriorated during the heat exposure, whereas that of the controls did not (P = 0.00. Conclusions The results suggest that the MSFC could be used as a simple tool to detect the negative effects of heat in patients with MS.

  5. Anharmonic phonon quasiparticle theory of zero-point and thermal shifts in insulators: Heat capacity, bulk modulus, and thermal expansion

    Science.gov (United States)

    Allen, Philip B.

    2015-08-01

    The quasiharmonic (QH) approximation uses harmonic vibrational frequencies ωQ ,H(V ) computed at volumes V near V0 where the Born-Oppenheimer (BO) energy Eel(V ) is minimum. When this is used in the harmonic free energy, QH approximation gives a good zeroth order theory of thermal expansion and first-order theory of bulk modulus, where nth-order means smaller than the leading term by ɛn, where ɛ =ℏ ωvib/Eel or kBT /Eel , and Eel is an electronic energy scale, typically 2 to 10 eV. Experiment often shows evidence for next-order corrections. When such corrections are needed, anharmonic interactions must be included. The most accessible measure of anharmonicity is the quasiparticle (QP) energy ωQ(V ,T ) seen experimentally by vibrational spectroscopy. However, this cannot just be inserted into the harmonic free energy FH. In this paper, a free energy is found that corrects the double-counting of anharmonic interactions that is made when F is approximated by FH( ωQ(V ,T ) ) . The term "QP thermodynamics" is used for this way of treating anharmonicity. It enables (n +1 ) -order corrections if QH theory is accurate to order n . This procedure is used to give corrections to the specific heat and volume thermal expansion. The QH formulas for isothermal (BT) and adiabatic (BS) bulk moduli are clarified, and the route to higher-order corrections is indicated.

  6. An apparatus for the specific heat measurement of undercooled liquids

    Science.gov (United States)

    Ohsaka, K.; Gatewood, J. R.; Trinh, E. H.

    1991-01-01

    This paper describes a drop calorimeter with an electromagnetic levitator that was specifically built for enthalpy measurements of undercooled liquids, including high-melting-point metals. Design diagrams of this device and of a furnace for making a suspended drop are presented together with results of measurements on an aluminum sample.

  7. Measurements of carbon dioxide and heat fluxes during monsoon ...

    Indian Academy of Sciences (India)

    An increase in carbon dioxide (CO2) concentrations in the atmosphere due to anthropogenic activities is responsible for global warming and hence in recent years, CO2 measurement network has expanded globally. In the monsoon season (July–September) of year 2011, we carried out measurements of CO2 and water ...

  8. Preventive measures and lifestyle habits against exertional heat illness in radiation decontamination workers.

    Science.gov (United States)

    Endo, Shota; Kakamu, Takeyasu; Sato, Sei; Hidaka, Tomoo; Kumagai, Tomohiro; Nakano, Shinichi; Koyama, Kikuo; Fukushima, Tetsuhito

    2017-09-28

    The aim of this study was to reveal the current state of preventive measures and lifestyle habits against heat illness in radiation decontamination workers and to examine whether young radiation decontamination workers take less preventive measures and have worse lifestyle habits than the elder workers. This was a cross-sectional study. Self-administered questionnaires were sent to 1,505 radiation decontamination workers in Fukushima, Japan. Five hundred fifty-eight men who replied and answered all questions were included in the statistical analysis. The questionnaire included age, duration of decontamination work, previous occupation, lifestyle habit, and preventive measures for heat illness. We classified age of the respondents into five groups: decontamination workers are more likely to have worse lifestyle habits and take insufficient preventive measures for heat illness. This may be the cause of higher incidence of heat illness among young workers.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2001-12-31

    A comprehensive description of the accomplishments of the DOE grant titled, ''Local Measurement of Fuel Energy Deposition and Heat Transfer Environment During Fuel Lifetime using Controlled Calorimetry''.

  10. Comprehensive assessments of measures mitigating heat island phenomena in urban areas; Heat shinku wo riyoshita daikibo reibo system no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    Mizuno, T.; Yamamoto, S.; Yoshikado, H.; Kondo, H.; Kaneho, N.; Saegusa, N.; Inaba, A. [National Institute for Resources and Environment, Tsukuba (Japan); Inoue, M. [New Energy and Industrial Technology Development Organization, Tokyo, (Japan)

    1997-02-01

    This paper describes the assessment method of measures mitigating heat island phenomena in urban areas. The heat island phenomena were classified into meso-scale with 100 km-scale, block-scale with several km-scale, and building-scale with 100 m-scale. Urban thermal environment simulation model was developed in response to each scale. For the development, regional data using aircraft and artificial satellite observations, surface observation and thermal environment observation at Shinjuku new central city of Tokyo, and artificial waste heat actual survey data in the southern Kanto district were utilized. Results of the urban thermal environment simulation were introduced as an application of this model. Temperature distributions of the heat island in the Kanto district were simulated with considering urban conditions near Tokyo and without considering it. Daily changes of wall surfaces of high buildings and road surface were calculated. Increase in the air temperature in the back stream of building roofs with increased temperature was determined. 4 figs.

  11. Development of whole energy absorption spectrometer for decay heat measurement on fusion reactor materials

    Energy Technology Data Exchange (ETDEWEB)

    Maekawa, Fujio; Ikeda, Yujiro [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1997-03-01

    To measure decay heat on fusion reactor materials irradiated by D-T neutrons, a Whole Energy Absorption Spectrometer (WEAS) consisting of a pair of large BGO (bismuth-germanate) scintillators was developed. Feasibility of decay heat measurement with WEAS for various materials and for a wide range of half-lives (seconds - years) was demonstrated by experiments at FNS. Features of WEAS, such as high sensitivity, radioactivity identification, and reasonably low experimental uncertainty of {approx} 10 %, were found. (author)

  12. Measurement of diffusion coefficient of liquid metals by using Gradient Heating Furnace in ISS

    OpenAIRE

    Masaki, Tadahiko; Itami, Toshio; Watanabe, Yuki; 正木 匡彦; 伊丹 俊夫; 渡辺 勇基

    2007-01-01

    The experimental techniques for the measurements of diffusion coefficient have been studied in JAXA toward the utilization of microgravity environment in ISS (International Space Station). The experimental cartridge for the gradient heating furnace, GHF (Gradient Heating Furnace), was developed for the application of shear cell which is the advanced technique of diffusion experiments. The temperature profiles of GHF were measured for the diffusion experiments and the isothermal condition can ...

  13. Heat transfer measurements in swept shock wave/turbulent boundary-layer interactions

    Science.gov (United States)

    Lee, Yeol

    An experimental research program providing basic knowledge and establishing a database on the heat transfer in three-dimensional shock wave/boundary-layer interaction is described. High thermal loading in such interactions constitutes a fundamental problem of critical concern to future supersonic and hypersonic flight vehicles. A turbulent boundary-layer on a flat plate is subjected to interactions with swept planar shock waves generated by a sharp fin. Fin angles from 10 deg to 20 deg at freestream Mach numbers 3.0 and 4.0 produce a variety of interaction strengths from weak to very strong. A foil heater generates a uniform heat flux over the surface of interest and thin-film resistance thermometers mounted on it are used to measure the local surface temperature. The heat convection equation is then used to calculate the local heat transfer coefficients. The present heat transfer technique is applied to measure heat transfer distributions for 5 different interaction cases. The experimental data are compared with numerical Navier-Stokes solutions. The estimation of total uncertainty of the present measurements is about plus or minus 10 percent, which makes them suitable for CFD code validation purposes. The measured peak heat transfer data are correlated with the normal Mach number based on the concept of the quasi-conical nature of such interactions, and the results show good agreement with other experimental data.

  14. An analysis of boundary-effects in obtaining the frequency dependent specific heat by effusivity measurements

    DEFF Research Database (Denmark)

    Christensen, Tage Emil; Behrens, Claus

    The frequency dependent specific heat is a significant response function characterizing the glass transition. Contrary to the dielectric response it is not easily measured over many decades. The introduction of the 3-omega method, where the temperature oscillations at a planar oscillatoric heat...... generator is measured, made this possible. The method relied on a 1-d solution to the heat diffusion equation. There have been attempts to invoke the boundary effects to first order. However we present the fully 3-d solution to the problem including these effects. The frequency range can hereby...

  15. Remote Heat Flux Measurement Using a Self Calibration Multiwavelength Pyrometer and a Transparent Material

    Science.gov (United States)

    Ng, Daniel

    1998-01-01

    A self calibrating multiwavelength pyrometer was used to conduct remote heat flux measurements using a transparent sapphire disk by determining the sapphire disk's front and back surface temperatures. Front surface temperature (Tfs) was obtained from detection of surface emitted radiation at long wavelengths (lambda > 6 micrometers). Back surface temperature (Tbs) was obtained from short wavelength (1 to 5 micrometers) radiation transmitted through the sapphire disk. The thermal conductivity k of the sapphire disk and the heat transfer coefficients h(sub 1) and h(sub 2) of its surfaces are determined experimentally. An analysis of the heat flux measurement is presented.

  16. Evaluation of an Absorption Heat Pump to Mitigate Plant Capacity Reduction Due to Ambient Temperature Rise for an Air-Cooled Ammonia and Water Cycle: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Bharathan, D.; Nix, G.

    2001-08-06

    Air-cooled geothermal plants suffer substantial decreases in generating capacity at increased ambient temperatures. As the ambient temperature rises by 50 F above a design value of 50 F, at low brine-resource temperatures, the decrease in generating capacity can be more than 50%. This decrease is caused primarily by increased condenser pressure. Using mixed-working fluids has recently drawn considerable attention for use in power cycles. Such cycles are more readily amenable to use of absorption ''heat pumps.'' For a system that uses ammonia and water as the mixed-working fluid, this paper evaluates using an absorption heat pump to reduce condenser backpressure. At high ambient temperatures, part of the turbine exhaust vapor is absorbed into a circulating mixed stream in an absorber in series with the main condenser. This steam is pumped up to a higher pressure and heated to strip the excess vapor, which is recondensed using an additional air-cooled condenser. The operating conditions are chosen to reconstitute this condensate back to the same concentration as drawn from the original system. We analyzed two power plants of nominal 1-megawatt capacity. The design resource temperatures were 250 F and 300 F. Ambient temperature was allowed to rise from a design value of 50 F to 100 F. The analyses indicate that using an absorption heat pump is feasible. For the 300 F resource, an increased brine flow of 30% resulted in a net power increase of 21%. For the 250 F resource, the increase was smaller. However, these results are highly plant- and equipment-specific because evaluations must be carried out at off-design conditions for the condenser. Such studies should be carried out for specific power plants that suffer most from increased ambient temperatures.

  17. Measurement of Heat Transfer Coefficients in an Agitated Vessel with Tube Baffles

    Directory of Open Access Journals (Sweden)

    M. Dostál

    2010-01-01

    Full Text Available Cooling or heating an agitated liquid is a very common operation in many industrial processes. A classic approach is to transfer the necessary heat through the vessel jacket. Another option, frequently used in the chemical and biochemical industries is to use the heat transfer area of vertical tube baffles. In large equipment, e.g. fermentor, the jacket surface is often not sufficient for large heat transfer requirements and tube baffles can help in such cases. It is then important to know the values of the heat transfer coefficients between the baffles and the agitated liquid. This paper presents the results of heat transfer measurements using the transient method when the agitated liquid is periodically heated and cooled by hot and cold water running through tube baffles. Solving the unsteady enthalpy balance, it is possible to determine the heat transfer coefficient. Our results are summarized by the Nusselt number correlations, which describe the dependency on the Reynolds number, and they are compared with other measurements obtained by a steady-state method.

  18. Spatially averaged heat flux and convergence measurements at the ARM regional flux experiment

    Energy Technology Data Exchange (ETDEWEB)

    Porch, W.; Barnes, F.; Buchwald, M.; Clements, W.; Cooper, D.; Hoard, D. (Los Alamos National Lab., NM (United States)); Doran, C.; Hubbe, J.; Shaw, W. (Pacific Northwest Lab., Richland, WA (United States)); Coulter, R.; Martin, T. (Argonne National Lab., IL (United States)); Kunkel, K. (Illinois State Water Survey, Champaign, IL (United States))

    1991-01-01

    Cloud formation and its relation to climate change is the greatest weakness in current numerical climate models. Surface heat flux in some cases causes clouds to form and in other to dissipate and the differences between these cases are subtle enough to make parameterization difficult in a numerical model. One of the goals of the DOE Atmospheric Radiation Measurement program is to make long term measurements at representative sites to improve radiation and cloud formation parameterization. This paper compares spatially averaged optical measurements of heat flux and convergence with a goal of determining how point measurements of heat fluxes scale up to the larger scale used for climate modeling. It was found that the various optical techniques used in this paper compared well with each other and with independent measurements. These results add confidence that spatially averaging optical techniques can be applied to transform point measurements to the larger scales needed for mesoscale and climate modeling. 10 refs., 6 figs. (MHB)

  19. Measurement of Ion Motional Heating Rates over a Range of Trap Frequencies and Temperatures

    CERN Document Server

    Bruzewicz, C D; Chiaverini, J

    2014-01-01

    We present measurements of the motional heating rate of a trapped ion at different trap frequencies and temperatures between $\\sim$0.6 and 1.5 MHz and $\\sim$4 and 295 K. Additionally, we examine the possible effect of adsorbed surface contaminants with boiling points below $\\sim$105$^{\\circ}$C by measuring the ion heating rate before and after locally baking our ion trap chip under ultrahigh vacuum conditions. We compare the heating rates presented here to those calculated from available electric-field noise models. We can tightly constrain a subset of these models based on their expected frequency and temperature scaling interdependence. Discrepancies between the measured results and predicted values point to the need for refinement of theoretical noise models in order to more fully understand the mechanisms behind motional trapped-ion heating.

  20. Ir Thermographic Measurements of Temperatures and Heat Fluxes in Hypersonic Plasma Flow

    Science.gov (United States)

    Cardone, G.; Tortora, G.; del Vecchio, A.

    2005-02-01

    The technological development achieved in instruments and methodology concerning both flights and ground hypersonic experiment (employed in space plane planning) goes towards an updating and a standardization of the heat flux technical measurements. In fact, the possibility to simulate high enthalpy flow relative to reentry condition by hypersonic arc-jet facility needs devoted methods to measure heat fluxes. Aim of this work is to develop an experimental numerical technique for the evaluation of heat fluxes over Thermal Protection System (TPS) by means of InfraRed (IR) thermographic temperature measurements and a new heat flux sensor (IR-HFS). We tackle the numerical validation of IR-HFS, apply the same one to the Hyflex nose cap model and compare the obtained results with others ones obtained by others methodology.

  1. A new method for simultaneous measurement of convective and radiative heat flux in car underhood applications

    Science.gov (United States)

    Khaled, M.; Garnier, B.; Harambat, F.; Peerhossaini, H.

    2010-02-01

    A new experimental technique is presented that allows simultaneous measurement of convective and radiative heat flux in the underhood. The goal is to devise an easily implemented and accurate experimental method for application in the vehicle underhood compartment. The new method is based on a technique for heat-flux measurement developed by the authors (Heat flow (flux) sensors for measurement of convection, conduction and radiation heat flow 27036-2, © Rhopoint Components Ltd, Hurst Green, Oxted, RH8 9AX, UK) that uses several thermocouples in the thickness of a thermal resistive layer (foil heat-flux sensor). The method proposed here uses a pair of these thermocouples with different radiative properties. Measurements validating this novel technique are carried out on a flat plate with a prescribed constant temperature in both natural- and forced-convection flow regimes. The test flat plate is instrumented by this new technique, and also with a different technique that is intrusive but very accurate, used as reference here (Bardon J P and Jarny Y 1994 Procédé et dispositif de mesure transitoire de température et flux surfacique Brevet n°94.011996, 22 February). Discrepancies between the measurements by the two techniques are less than 10% for both convective and radiative heat flux. Error identification and sensitivity analysis of the new method are also presented.

  2. Isothermal calorimeter for measurements of time-dependent heat generation rate in individual supercapacitor electrodes

    Science.gov (United States)

    Munteshari, Obaidallah; Lau, Jonathan; Krishnan, Atindra; Dunn, Bruce; Pilon, Laurent

    2018-01-01

    Heat generation in electric double layer capacitors (EDLCs) may lead to temperature rise and reduce their lifetime and performance. This study aims to measure the time-dependent heat generation rate in individual carbon electrode of EDLCs under various charging conditions. First, the design, fabrication, and validation of an isothermal calorimeter are presented. The calorimeter consisted of two thermoelectric heat flux sensors connected to a data acquisition system, two identical and cold plates fed with a circulating coolant, and an electrochemical test section connected to a potentiostat/galvanostat system. The EDLC cells consisted of two identical activated carbon electrodes and a separator immersed in an electrolyte. Measurements were performed on three cells with different electrolytes under galvanostatic cycling for different current density and polarity. The measured time-averaged irreversible heat generation rate was in excellent agreement with predictions for Joule heating. The reversible heat generation rate in the positive electrode was exothermic during charging and endothermic during discharging. By contrast, the negative electrode featured both exothermic and endothermic heat generation during both charging and discharging. The results of this study can be used to validate existing thermal models, to develop thermal management strategies, and to gain insight into physicochemical phenomena taking place during operation.

  3. An Optical-Based Aggregate Approach to Measuring Condensation Heat Transfer

    Science.gov (United States)

    Stevens, Kimberly A.; Crockett, Julie; Maynes, Daniel R.; Iverson, Brian D.

    2017-11-01

    Condensation heat transfer is significant in a variety of industries including desalination, energy conversion, atmospheric water harvesting, and electronics cooling. Recently, superhydrophobic surfaces have gained attention as a possible condensing surface due to their potential for high droplet mobility and coalescence-induced, out-of-plane jumping of the condensate droplets, both of which contribute to higher rates of condensate removal and thus higher thermal transport rates. Several studies involving condensation on superhydrophobic surfaces have quantified metrics which indirectly indicate the relative rate of heat transfer on a surface, such as maximum droplet diameter, drop size distribution, and individual droplet growth rates. In this study, an optical-based method is used to monitor growth and departure of individual condensate drops for the entire viewing area to obtain full-field, aggregate heat transfer measurements. This approach offers several advantages relative to traditional heat transfer measurement methods such as heat flux sensors and thermocouples, including the ability to provide a link between macroscopic heat transfer rates and the more indirect measures of heat transfer traditionally reported in the literature.

  4. Ex vivo measures of muscle mitochondrial capacity reveal quantitative limits of oxygen delivery by the circulation during exercise

    DEFF Research Database (Denmark)

    Boushel, Robert; Saltin, Bengt

    2013-01-01

    Muscle mitochondrial respiratory capacity measured ex vivo provides a physiological reference to assess cellular oxidative capacity as a component in the oxygen cascade in vivo. In this article, the magnitude of muscle blood flow and oxygen uptake during exercise involving a small-to-large fracti...... capacity measured ex vivo underestimates the maximal in vivo oxygen uptake of muscle by up to ∼2-fold. This article is part of a Directed Issue entitled: Bioenergetic dysfunction, adaptation and therapy.......Muscle mitochondrial respiratory capacity measured ex vivo provides a physiological reference to assess cellular oxidative capacity as a component in the oxygen cascade in vivo. In this article, the magnitude of muscle blood flow and oxygen uptake during exercise involving a small-to-large fraction...... of the body mass will be discussed in relation to mitochondrial capacity measured ex vivo. These analyses reveal that as the mass of muscle engaged in exercise increases from one-leg knee extension, to 2-arm cranking, to 2-leg cycling and x-country skiing, the magnitude of blood flow and oxygen delivery...

  5. Measurements of carbon dioxide and heat fluxes during monsoon ...

    Indian Academy of Sciences (India)

    2011-08-04

    sonic anemometer for wind and temperature, and the open path H2O/CO2 infrared gas analyzer for CO2 .... at 8 m height upto August 4, 2011 and later, the system was shifted to 6 m height to make provision for other measurements at 8 m. The precipitation. Table 1. .... nounced because of the absence of solar radiation.

  6. Measuring the Specific Heat of Metals by Cooling

    Science.gov (United States)

    Dittrich, William; Minkin, Leonid; Shapovalov, Alexander S.

    2010-01-01

    Three in one? Yes, three standard undergraduate thermodynamics experiments in one, not an oval can of lubricating oil. Previously it has been shown that the PASCO scientific apparatus for measuring coefficients of thermal expansion of metals can also be used to illustrate Newton's law of cooling in the same experiment. Now it will be shown that by…

  7. Method and apparatus for real-time measurement of fuel gas compositions and heating values

    Science.gov (United States)

    Zelepouga, Serguei; Pratapas, John M.; Saveliev, Alexei V.; Jangale, Vilas V.

    2016-03-22

    An exemplary embodiment can be an apparatus for real-time, in situ measurement of gas compositions and heating values. The apparatus includes a near infrared sensor for measuring concentrations of hydrocarbons and carbon dioxide, a mid infrared sensor for measuring concentrations of carbon monoxide and a semiconductor based sensor for measuring concentrations of hydrogen gas. A data processor having a computer program for reducing the effects of cross-sensitivities of the sensors to components other than target components of the sensors is also included. Also provided are corresponding or associated methods for real-time, in situ determination of a composition and heating value of a fuel gas.

  8. Experimental measurements of heat transfer from an iced surface during artificial and natural cloud icing conditions

    Science.gov (United States)

    Kirby, M. S.; Hansman, R. J., Jr.

    1986-01-01

    The heat transfer behavior of accreting ice surfaces in natural (flight test) and simulated (wind tunnel) cloud icing conditions have been studied. Observations of wet and dry ice growth regimes as measured by ultrasonic pulse-echo techniques were made. Observed wet and dry ice growth regimes at the stagnation point of a cylinder were compared with those predicted using a quasi steady-state heat balance model. A series of heat transfer coefficients were employed by the model to infer the local heat transfer behavior of the actual ice surfaces. The heat transfer in the stagnation region was generally inferred to be higher in wind tunnel icing tests than in natural, flight, icing conditions.

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

    DEFF Research Database (Denmark)

    Sørensen, Lars Schiøtt

    2012-01-01

    for heating up, and cooling down our houses. There is a huge energy saving potential on this area reducing both the World climate problems and economy challenges as well. Heating of buildings in Denmark counts for approximately 40% of the entire national energy consume. Of this reason a reduction of heat...... losses from building envelopes are of great impor­tance in order to reach the Bologna CO2-emission reduction goals. Energy renovation of buildings is a topic of huge focus around the world these years. Not only expenses for heating in the tempered and arctic regions are of importance, but also expenses...... to ACMV in the "warm countries" contribute to an enormous energy consumption and corresponding CO2 emission. In order to establish the best basis for energy renovation, it is important to have measures of the heat losses on a building façade, for optimizing the energy renovation. This paper will present...

  10. Spatially Resolved Measurements of Ion Heating during Impulsive Reconnection in the Madison Symmetric Torus

    Science.gov (United States)

    Gangadhara, S.; Craig, D.; Ennis, D. A.; Hartog, D. J. Den; Fiksel, G.; Prager, S. C.

    2007-02-01

    The impurity ion temperature evolution has been measured during three types of impulsive reconnection events in the Madison Symmetric Torus reversed field pinch. During an edge reconnection event, the drop in stored magnetic energy is small and ion heating is observed to be limited to the outer half of the plasma. Conversely, during a global reconnection event the drop in stored magnetic energy is large, and significant heating is observed at all radii. For both kinds of events, the drop in magnetic energy is sufficient to explain the increase in ion thermal energy. However, not all types of reconnection lead to ion heating. During a core reconnection event, both the stored magnetic energy and impurity ion temperature remain constant. The results suggest that a drop in magnetic energy is required for ions to be heated during reconnection, and that when this occurs heating is localized near the reconnection layer.

  11. Analysis of electrical energy consumers operation in the heating plant with proposal of energy savings measures

    Directory of Open Access Journals (Sweden)

    Nikolić Aleksandar

    2016-01-01

    Full Text Available The results of power quality measurements, obtained during an energy audit in the heating plant Vreoci in the Electric Power System of Serbia, are presented in the paper. Two steam boilers, rated at 120MW each, are installed in this heating plant, using coal as a fuel. The energy audit encompassed the measurements of the complete set of parameters needed to determine the thermal efficacy of boilers and the entire heating plant. Based on the measurement results, several technical measures for improving energy efficiency of the plant are proposed. The measures evaluated in the paper should contribute to the reduction of fossil fuel usage and CO2 emissions, thereby resulting in a significant impact in both financial and ecological areas.

  12. Uncertainty analysis of steady state incident heat flux measurements in hydrocarbon fuel fires.

    Energy Technology Data Exchange (ETDEWEB)

    Nakos, James Thomas

    2005-12-01

    The objective of this report is to develop uncertainty estimates for three heat flux measurement techniques used for the measurement of incident heat flux in a combined radiative and convective environment. This is related to the measurement of heat flux to objects placed inside hydrocarbon fuel (diesel, JP-8 jet fuel) fires, which is very difficult to make accurately (e.g., less than 10%). Three methods will be discussed: a Schmidt-Boelter heat flux gage; a calorimeter and inverse heat conduction method; and a thin plate and energy balance method. Steady state uncertainties were estimated for two types of fires (i.e., calm wind and high winds) at three times (early in the fire, late in the fire, and at an intermediate time). Results showed a large uncertainty for all three methods. Typical uncertainties for a Schmidt-Boelter gage ranged from {+-}23% for high wind fires to {+-}39% for low wind fires. For the calorimeter/inverse method the uncertainties were {+-}25% to {+-}40%. The thin plate/energy balance method the uncertainties ranged from {+-}21% to {+-}42%. The 23-39% uncertainties for the Schmidt-Boelter gage are much larger than the quoted uncertainty for a radiative only environment (i.e ., {+-}3%). This large difference is due to the convective contribution and because the gage sensitivities to radiative and convective environments are not equal. All these values are larger than desired, which suggests the need for improvements in heat flux measurements in fires.

  13. Heat-Flux Measurements in Laser-Produced Plasmas Using Thomson Scattering from Electron Plasma Waves

    Science.gov (United States)

    Henchen, R. J.; Goncharov, V. N.; Cao, D.; Katz, J.; Froula, D. H.; Rozmus, W.

    2017-10-01

    An experiment was designed to measure heat flux in coronal plasmas using collective Thomson scattering. Adjustments to the electron distribution function resulting from heat flux affect the shape of the collective Thomson scattering features through wave-particle resonance. The amplitude of the Spitzer-Härm electron distribution function correction term (f1) was varied to match the data and determines the value of the heat flux. Independent measurements of temperature and density obtained from Thomson scattering were used to infer the classical heat flux (q = - κ∇Te) . Time-resolved Thomson-scattering data were obtained at five locations in the corona along the target normal in a blowoff plasma formed from a planar Al target with 1.5 kJ of 351-nm laser light in a 2-ns square pulse. The flux measured through the Thomson-scattering spectra is a factor of 5 less than the κ∇Te measurements. The lack of collisions of heat-carrying electrons suggests a nonlocal model is needed to accurately describe the heat flux. This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Number DE-NA0001944.

  14. Evaluating parameterizations of aerodynamic resistance to heat transfer using field measurements

    Directory of Open Access Journals (Sweden)

    Shaomin Liu

    2007-01-01

    Full Text Available Parameterizations of aerodynamic resistance to heat and water transfer have a significant impact on the accuracy of models of land – atmosphere interactions and of estimated surface fluxes using spectro-radiometric data collected from aircrafts and satellites. We have used measurements from an eddy correlation system to derive the aerodynamic resistance to heat transfer over a bare soil surface as well as over a maize canopy. Diurnal variations of aerodynamic resistance have been analyzed. The results showed that the diurnal variation of aerodynamic resistance during daytime (07:00 h–18:00 h was significant for both the bare soil surface and the maize canopy although the range of variation was limited. Based on the measurements made by the eddy correlation system, a comprehensive evaluation of eight popularly used parameterization schemes of aerodynamic resistance was carried out. The roughness length for heat transfer is a crucial parameter in the estimation of aerodynamic resistance to heat transfer and can neither be taken as a constant nor be neglected. Comparing with the measurements, the parameterizations by Choudhury et al. (1986, Viney (1991, Yang et al. (2001 and the modified forms of Verma et al. (1976 and Mahrt and Ek (1984 by inclusion of roughness length for heat transfer gave good agreements with the measurements, while the parameterizations by Hatfield et al. (1983 and Xie (1988 showed larger errors even though the roughness length for heat transfer has been taken into account.

  15. Cavity assisted measurements of heat and work in optical lattices

    Directory of Open Access Journals (Sweden)

    Louis Villa

    2018-01-01

    Full Text Available We propose a method to experimentally measure the internal energy of a system of ultracold atoms trapped in optical lattices by coupling them to the fields of two optical cavities. We show that the tunnelling and self-interaction terms of the one-dimensional Bose-Hubbard Hamiltonian can be mapped to the field and photon number of each cavity, respectively. We compare the energy estimated using this method with numerical results obtained using the density matrix renormalisation group algorithm. Our method can be employed for the assessment of power and efficiency of thermal machines whose working substance is a strongly correlated many-body system.

  16. A comparative measurement technique of nanoparticle heating for magnetic hyperthermia applications

    Science.gov (United States)

    Drayton, A.; Zehner, J.; Timmis, J.; Patel, V.; Vallejo-Fernandez, G.; O’Grady, K.

    2017-12-01

    We describe a method for the determination of the heating power of magnetic nanoparticle colloids which have potential for application in the remedial treatment of malignant and non-malignant tumours. The method is based upon a comparison between the heating power observed when the colloid is exposed to a radio frequency magnetic field and that which is observed using a resistive electrical heater. A new design of the measurement cell has been made which has the advantages of reducing or eliminating the effects of convection, ensuring the measurement is made in a magnetic field of known uniformity and that the heat losses in the system are constant and minimized under both magnetic and Joule heating.

  17. Simultaneous Temperature and Velocity Measurements in a Large-Scale, Supersonic, Heated Jet

    Science.gov (United States)

    Danehy, P. M.; Magnotti, G.; Bivolaru, D.; Tedder, S.; Cutler, A. D.

    2008-01-01

    Two laser-based measurement techniques have been used to characterize an axisymmetric, combustion-heated supersonic jet issuing into static room air. The dual-pump coherent anti-Stokes Raman spectroscopy (CARS) measurement technique measured temperature and concentration while the interferometric Rayleigh scattering (IRS) method simultaneously measured two components of velocity. This paper reports a preliminary analysis of CARS-IRS temperature and velocity measurements from selected measurement locations. The temperature measurements show that the temperature along the jet axis remains constant while dropping off radially. The velocity measurements show that the nozzle exit velocity fluctuations are about 3% of the maximum velocity in the flow.

  18. Heated, perspiring manikin headform for the measurement of headgear ventilation characteristics

    Science.gov (United States)

    Brühwiler, P. A.

    2003-02-01

    Details of a heated manikin headform with computer-controlled perspiration are presented. The heat exchange properties of the headform with and without perspiration are compared to those of human beings and other manikins, showing quite good agreement, and are then applied to measure the ventilation characteristics of motorcycle and bicycle helmets. Subtle differences between two helmets are observed in each case, illustrating the sensitivity of the headform.

  19. Noninvasive measurement of arterial oxyhemoglobin saturation with a heated and a non-heated skin reflectance pulse oximeter sensor.

    Science.gov (United States)

    Mendelson, Y; Yocum, B L

    1991-01-01

    The feasibility of measuring arterial oxyhemoglobin saturation (SaO2) noninvasively using a skin reflectance pulse oximeter sensor attached to the scalp, neck, and thigh regions of anesthetized swine was investigated. The optical reflectance sensor used consisted of a pair of red and infrared light-emitting diodes and a concentric array of six identical photodiodes. Two prototype sensor assemblies were evaluated: one assembly housed only the optical sensor, whereas the other also included a miniature heater. Measurements made from the scalp and neck regions were obtained with the non-heated skin reflectance sensor, and measurements from the thigh were made with the heated prototype. Each sensor was interfaced to a commercial transmittance pulse oximeter adapted to perform as a reflectance pulse oximeter. SaO2 values obtained by the reflectance pulse oximeters (SpO2(r) were compared simultaneously with SaO2 values obtained from arterial blood samples and analyzed in vitro with a CO-oximeter. The equations for the best-fitted linear regression lines describing the relationships between SpO2(r) and SaO2 values in the range between 30 and 100% were: SpO2(r) = 10.7 + 0.90 (SaO2), n = 321, r = 0.97; SpO2(r) = 16.72 + 0.82 (SaO2), n = 217, r = 0.95; and SpO2(r) = 20.21 + 0.77 (SaO2), n = 37, r = 0.97 for the neck, thigh, and scalp measurements, respectively. The regression analysis revealed significant correlation and a relatively small standard error of estimate (SEE = 4.05% for the neck, 4.79% for the thigh, and 3.50% for the scalp measurements). This study demonstrated the feasibility of measuring SaO2 noninvasively over a wide range of values utilizing the principle of reflectance pulse oximetry.

  20. Change in heat capacity upon the solvation of alkali metal ions in N-methylpyrrolidone and mixed N-methylpyrrolidone-water solvent

    Science.gov (United States)

    Novikov, A. N.; Solov'ev, S. N.

    2012-09-01

    The change in heat capacity upon ion solvation Δsolv C {/p,i o} in N-methylpyrrolidone (MP) and in mixed MP-water solvent is presented as the sum of three contributions: electrostatic, cavity formation, and changes in the structure of the solvent. The values for the electrostatic and cavity formation contributions are calculated using model concepts. The values of the structural contribution are determined. The obtained data was analyzed in dependence on the solvent's composition and the electrostatic ion parameters.

  1. ESTIMATIONS OF HEAT CAPACITIES FOR ACTINIDE DIOXIDE: UO2, NpO2, ThO2, AND PuO2

    Directory of Open Access Journals (Sweden)

    E. ESER

    2014-12-01

    Full Text Available The evaluation of thermal properties of actinide oxide fuels is a problem of high importance for the development of new generation reactors. In the present study, an expression obtained for n-dimensional Debye functions is used to derive a simple analytical expression for the specific heat capacity of nuclear fuels. To test the validity and reliability of this expression, the analytical expression is applied to UO2, NpO2, ThO2, and PuO2. It is seen that the formula was in agreement with the experimental and theoretical results reported in the literature.

  2. Direct experimental evidence for a negative heat capacity in the liquid-to-gas like phase transition in hydrogen cluster ions backbending of the caloric curve

    CERN Document Server

    Gobet, F; Carré, M; Farizon, B; Farizon, M; Gaillard, M J; Maerk, T D; Scheier, P

    2002-01-01

    By (i) selecting specific decay reactions in high energy collisions (60 keV/amu) of hydrogen cluster ions with a helium target (utilizing event-by-event data of a recently developed multi-coincidence experiment) and by (ii) deriving corresponding temperatures for these microcanonical cluster ensembles (analyzing the respective fragment distributions) we are able to construct caloric curves for ii sub 3 sup + (ii sub 2) sub m cluster ions (6 <= m <= 14). All individual curves and the mean of these curves show a backbending in the plateau region thus constituting direct evidence for a negative microcanonical heat capacity in the liquid-to-gas like transition of these finite systems.

  3. Measuring working memory capacity in children using adaptive tasks: Example validation of an adaptive complex span.

    Science.gov (United States)

    Gonthier, Corentin; Aubry, Alexandre; Bourdin, Béatrice

    2017-06-22

    Working memory tasks designed for children usually present trials in order of ascending difficulty, with testing discontinued when the child fails a particular level. Unfortunately, this procedure comes with a number of issues, such as decreased engagement from high-ability children, vulnerability of the scores to temporary mind-wandering, and large between-subjects variations in number of trials, testing time, and proactive interference. To circumvent these problems, the goal of the present study was to demonstrate the feasibility of assessing working memory using an adaptive testing procedure. The principle of adaptive testing is to dynamically adjust the level of difficulty as the task progresses to match the participant's ability. We used this method to develop an adaptive complex span task (the ACCES) comprising verbal and visuo-spatial subtests. The task presents a fixed number of trials to all participants, allows for partial credit scoring, and can be used with children regardless of ability level. The ACCES demonstrated satisfying psychometric properties in a sample of 268 children aged 8-13 years, confirming the feasibility of using adaptive tasks to measure working memory capacity in children. A free-to-use implementation of the ACCES is provided.

  4. Measurements of the acid-binding capacity of ingredients used in pig diets

    Directory of Open Access Journals (Sweden)

    Lawlor Peadar G

    2005-08-01

    Full Text Available Some feed ingredients bind more acid in the stomach than others and for this reason may be best omitted from pig starter foods if gastric acidity is to be promoted. The objective of this study was to measure the acid-binding capacity (ABC of ingredients commonly used in pig starter foods. Ingredients were categorised as follows: (i milk products (n = 6, (ii cereals (n = 10, (iii root and pulp products (n = 5, (iv vegetable proteins (n = 11, (v meat and fish meal (n = 2, (vi medication (n = 3, (vii amino acids (n = 4, (viii minerals (n = 16, (ix acid salts (n = 4, (x acids (n = 10. A 0.5 g sample of food was suspended in 50 ml distilled de-ionised water with continuous stirring. This suspension was titrated with 0.1 mol/L HCl or 0.1 mol/L NaOH so that approximately 10 additions of titrant was required to reach pH 3.0. The pH readings after each addition were recorded following equilibration for three minutes. ABC was calculated as the amount of acid in milliequivalents (meq required to lower the pH of 1 kg food to (a pH 4.0 (ABC-4 and (b pH 3.0 (ABC-3. Categories of food had significantly different (P

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

    Science.gov (United States)

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

    2015-01-01

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

  6. Standard Test Method for Measuring Heat Transfer Rate Using a Thin-Skin Calorimeter

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2005-01-01

    1.1 This test method covers the design and use of a thin metallic calorimeter for measuring heat transfer rate (also called heat flux). Thermocouples are attached to the unexposed surface of the calorimeter. A one-dimensional heat flow analysis is used for calculating the heat transfer rate from the temperature measurements. Applications include aerodynamic heating, laser and radiation power measurements, and fire safety testing. 1.2 Advantages 1.2.1 Simplicity of ConstructionThe calorimeter may be constructed from a number of materials. The size and shape can often be made to match the actual application. Thermocouples may be attached to the metal by spot, electron beam, or laser welding. 1.2.2 Heat transfer rate distributions may be obtained if metals with low thermal conductivity, such as some stainless steels, are used. 1.2.3 The calorimeters can be fabricated with smooth surfaces, without insulators or plugs and the attendant temperature discontinuities, to provide more realistic flow conditions for ...

  7. Standard Test Method for Measuring Heat Flux Using Surface-Mounted One-Dimensional Flat Gages

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2009-01-01

    1.1 This test method describes the measurement of the net heat flux normal to a surface using flat gages mounted onto the surface. Conduction heat flux is not the focus of this standard. Conduction applications related to insulation materials are covered by Test Method C 518 and Practices C 1041 and C 1046. The sensors covered by this test method all use a measurement of the temperature difference between two parallel planes normal to the surface to determine the heat that is exchanged to or from the surface in keeping with Fourier’s Law. The gages operate by the same principles for heat transfer in either direction. 1.2 This test method is quite broad in its field of application, size and construction. Different sensor types are described in detail in later sections as examples of the general method for measuring heat flux from the temperature gradient normal to a surface (1). Applications include both radiation and convection heat transfer. The gages have broad application from aerospace to biomedical en...

  8. Measurement Approach of Mean Heat Transfer Coefficient for Packed Bed of Vegetables

    Directory of Open Access Journals (Sweden)

    Łapiński Adam

    2017-03-01

    Full Text Available The non-invasive measurement approach of the mean heat transfer coefficient for the packed bed of vegetables may be thought as still open issue. There is a clear need for the assessment of heat transfer conditions for various types of fruits and vegetables in order to accurately predict the thermal load that is necessary to select refrigeration equipment for cold storage chamber. Additionally, there is significant development in numerical modelling of heat and mass transfer processes in cold storage chambers for fruits and vegetables which requires precise heat transfer prediction. The theoretical basis for the indirect measurement approach of mean heat transfer coefficient for the packed bed of vegetables that is based on single blow technique is presented and discussed in the paper. The approach based on the modified model of Liang and Yang was presented and discussed. The testing stand consisted of a dedicated experimental tunnel along with auxiliary equipment and measurement system are presented. The geometry of the tested vegetables bed were presented. Selected experimental results of heat transfer are presented and discussed for the packed bed of carrots. These results were presented as dimensionless relationship. The obtained results were compared with the existing dimensionless relationships developed for the packed bed consisting of elements of various regular shapes.

  9. High geothermal heat flux measured below the West Antarctic Ice Sheet.

    Science.gov (United States)

    Fisher, Andrew T; Mankoff, Kenneth D; Tulaczyk, Slawek M; Tyler, Scott W; Foley, Neil

    2015-07-01

    The geothermal heat flux is a critical thermal boundary condition that influences the melting, flow, and mass balance of ice sheets, but measurements of this parameter are difficult to make in ice-covered regions. We report the first direct measurement of geothermal heat flux into the base of the West Antarctic Ice Sheet (WAIS), below Subglacial Lake Whillans, determined from the thermal gradient and the thermal conductivity of sediment under the lake. The heat flux at this site is 285 ± 80 mW/m(2), significantly higher than the continental and regional averages estimated for this site using regional geophysical and glaciological models. Independent temperature measurements in the ice indicate an upward heat flux through the WAIS of 105 ± 13 mW/m(2). The difference between these heat flux values could contribute to basal melting and/or be advected from Subglacial Lake Whillans by flowing water. The high geothermal heat flux may help to explain why ice streams and subglacial lakes are so abundant and dynamic in this region.

  10. [Measuring water ecological carrying capacity with the ecosystem-service-based ecological footprint (ESEF) method: Theory, models and application].

    Science.gov (United States)

    Jiao, Wen-jun; Min, Qing-wen; Li, Wen-hua; Fuller, Anthony M

    2015-04-01

    Integrated watershed management based on aquatic ecosystems has been increasingly acknowledged. Such a change in the philosophy of water environment management requires recognizing the carrying capacity of aquatic ecosystems for human society from a more general perspective. The concept of the water ecological carrying capacity is therefore put forward, which considers both water resources and water environment, connects socio-economic development to aquatic ecosystems and provides strong support for integrated watershed management. In this paper, the authors proposed an ESEF-based measure of water ecological carrying capacity and constructed ESEF-based models of water ecological footprint and capacity, aiming to evaluate water ecological carrying capacity with footprint methods. A regional model of Taihu Lake Basin was constructed and applied to evaluate the water ecological carrying capacity in Changzhou City which located in the upper reaches of the basin. Results showed that human demand for water ecosystem services in this city had exceeded the supply capacity of local aquatic ecosystems and the significant gap between demand and supply had jeopardized the sustainability of local aquatic ecosystems. Considering aqua-product provision, water supply and pollutant absorption in an integrated way, the scale of population and economy aquatic ecosystems in Changzhou could bear only 54% of the current status.

  11. Test-re-test reproducibility of activity capacity measures for children with an acquired brain injury.

    Science.gov (United States)

    Baque, Emmah; Barber, Lee; Sakzewski, Leanne; Boyd, Roslyn N

    2016-01-01

    To determine test-re-test reproducibility of the Timed Up & Go (TUG) test, 30-second repetition maximum (repmax) of functional exercises, 6-Minute Walk Test (6MWT) and High-level Mobility Assessment Tool (HiMAT) in children with Acquired Brain Injury (ABI). Secondarily, to assess the accuracy between hand-timed and video-timed scores for the TUG test and HiMAT. Thirty children at least 1 year post-ABI (mean age at assessment = 11 years 11 months, SD = 2 years 4 months; 14 males; Gross Motor Function Classification Scale I = 17, II = 13) were assessed twice. Intra-class correlation coefficients (ICC), standard error of measurement and minimum detectable change (MDC) were determined. The Bland-Altman method and 95% limits of agreement (LOA) were used to assess the agreement between hand and video-timed TUG test and HiMAT scores. Test-re-test reproducibility was acceptable for the TUG test (ICC = 0.92; MDC = 1.2s); repmax of functional exercises (ICC = 0.84-0.98; MDC = 4-8 reps); 6MWT (ICC = 0.90; MDC = 69.38 m) and HiMAT (ICC = 0.98; MDC = 6). Comparison of hand and video scores for the TUG test and HiMAT demonstrated a mean difference of 0.23 (LOA = -0.3-0.7) and -0.07 (LOA = -1.99-1.85), respectively. Conclusions Test-re-test reproducibility of lower limb activity capacity measures in children with ABI are acceptable. The MDC scores provide a useful reference to interpret treatment effectiveness. Video timing was more accurate than hand-timing for the TUG test.

  12. Titration and Spectroscopic Measurements of Poultry Litter pH Buffering Capacity.

    Science.gov (United States)

    Cassity-Duffey, Kate; Cabrera, Miguel; Mowrer, Jake; Kissel, David

    2015-07-01

    The pH value of poultry litter is affected by nitrification, mineralization, and the addition of acidifying chemicals, all acting on the poultry litter pH buffering capacity (pHBC). Increased understanding of poultry litter pHBC will aid in modeling NH volatilization from surface-applied poultry litter as well as estimating rates of alum applications. Our objectives were to (i) determine the pHBC of a wide range of poultry litters; (ii) assess the accuracy of near-infrared reflectance spectroscopy (NIRS) for determining poultry litter pHBC; and (iii) demonstrate the use of poultry litter pHBC to increase the accuracy of alum additions. Litter pHBC was determined by titration and calculated from linear and sigmoidal curves. For the 37 litters measured, linear pHBC ranged from 187 to 537 mmol (pH unit) kg dry litter. The linear and sigmoidal curves provided accurate predictions of pHBC, with most > 0.90. Results from NIRS analysis showed that the linear pHBC expressed on an "as is" water content basis had a NIRS coefficient of calibration (developed using a modified partial least squares procedure) of 0.90 for the 37 poultry litters measured. Using the litter pHBC, an empirical model was derived to determine the amount of alum needed to create a target pH. The model performed well in the range of pH 6.5 to 7.5 (RMSE = 0.07) but underpredicted the amount of alum needed to reach pH poultry litter, which prevented its hydrolysis. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  13. Measuring heat balance residual at lake surface using distributed temperature sensing

    NARCIS (Netherlands)

    Van Emmerik, T.H.M.; Rimmer, A.; Lechinsky, Y.; Wenker, K.J.R.; Nussboim, S.; Van de Giesen, N.C.

    2013-01-01

    This research presents a new method to verify the measurements of surface fluxes and the heat balance at a lake surface, by means of Distributed Temperature Sensing (DTS) measurements from 0.5 m above to 1.5 m below the surface. Using a polyvinyl chloride hyperboloid construction, a floating

  14. The Measurement of the Specific Latent Heat of Fusion of Ice: Two Improved Methods.

    Science.gov (United States)

    Mak, S. Y.; Chun, C. K. W.

    2000-01-01

    Suggests two methods for measuring the specific latent heat of ice fusion for high school physics laboratories. The first method is an ice calorimeter which is made from simple materials. The second method improves the thermal contact and allows for a more accurate measurement. Lists instructions for both methods. (Author/YDS)

  15. Specifications for temperature measurement in the district heating sector; Anforderungen an die Temperaturmessung in der Fernwaerme

    Energy Technology Data Exchange (ETDEWEB)

    Mathies, Nicolaus [Krohne Messtechnik GmbH, Duisburg (Germany); Schupp, Reiner [MID-Cert GmbH, Essen (Germany)

    2010-04-15

    Wrong design of thermometers often causes faulty billing. Correct design depends on the requirements of the market segment and of the heating systems concerned. Additionally, aspects resulting from the measurement process and the environmental conditions must be taken into account as well as equipment-specific criteria. The authors outline the requirements to a correct temperature measurement. (orig./GL)

  16. Soil-water evaporation dynamics determined with measurement of sensible heat transfer

    Science.gov (United States)

    Soil-water evaporation is important in both the hydrologic cycle and the surface energy balance. Yet, routine measurements are unable to capture rapidly shifting near-surface soil heat and water processes involved in evaporation. Recent improvements for fine-scale measurement of soil thermal propert...

  17. Dynamic Heat Storage and Cooling Capacity of a Concrete Deck with PCM and Thermally Activated Building System

    DEFF Research Database (Denmark)

    Pomianowski, Michal Zbigniew; Heiselberg, Per; Jensen, Rasmus Lund

    2012-01-01

    with and without microencapsulated PCM are presented. The new concrete deck with microencapsulated PCM is the standard deck on which an additional layer of the PCM concrete was added and, at the same time, the latent heat storage was introduced to the construction. The challenge of numerically simulating...

  18. Effects of Chlorination and Heat Treatment on Flour and Gluten Functionality Explored by Solvent Retention Capacity (SRC) and Mixograph

    Science.gov (United States)

    The effects of chlorination and heat treatment on flour and gluten functionality were explored by SRC and mixograph for the soft wheat cultivar, Croplan 594W. Regardless of milling yield, SRC results for chlorinated flour samples showed a decrease in lactic acid SRC values with increasing extent of...

  19. Antioxidant activity of the giant jellyfish Nemopilema nomurai measured by the oxygen radical absorbance capacity and hydroxyl radical averting capacity methods.

    Science.gov (United States)

    Harada, Kazuki; Maeda, Toshimichi; Hasegawa, Yoshiro; Tokunaga, Takushi; Ogawa, Shinya; Fukuda, Kyoko; Nagatsuka, Norie; Nagao, Keiko; Ueno, Shunshiro

    2011-01-01

    The giant jellyfish Nemopilema nomurai (reaching sizes of up to 2 m diameter and 150 kg), which forms dense blooms, has caused extensive damage to fisheries by overloading trawl nets, while its toxic nematocysts cause dermatological symptoms. Giant jellyfish are currently discarded on the grounds of pest control. However, the giant jellyfish is considered to be edible and is part of Chinese cuisine. Therefore, we investigated whether any benefits for human health may be derived from consumption of the jellyfish in order to formulate medicated diets. Antioxidant activity of Nemopilema nomurai was measured using the oxygen radical absorbance capacity (ORAC) and hydroxyl radical averting capacity (HORAC) methods. Based on the results, the ORAC value of the giant jellyfish freeze-dried sample was 541 µmol trolox equivalent (TE)/100 g and the HORAC value was 3,687 µmol gallic acid equivalent (GAE)/100 g. On the other hand, the IC50 value of hydroxyl radical scavenging activity measured by using the electron spin resonance method was 3.3%. In conclusion, the results suggest that the freeze-dried powder of the giant jellyfish Nemopilema nomurai is a potentially beneficial food for humans.

  20. Dielectric and magnetic properties of NiFe{sub 2}O{sub 4} at 2.45 GHz and heating capacity for potential uses under microwaves

    Energy Technology Data Exchange (ETDEWEB)

    Polaert, Isabelle, E-mail: isabelle.polaert@insa-rouen.fr [LSPC (Laboratoire de Sécurité des Procédés Chimiques). Institut National des Sciences Appliquées INSA Rouen (France); Bastien, Samuel [Département de génie chimique et de génie biotechnologique, Université de Sherbrooke, Sherbrooke, Québec, Canada J1K 2R1 (Canada); Legras, Benoit [LSPC (Laboratoire de Sécurité des Procédés Chimiques). Institut National des Sciences Appliquées INSA Rouen (France); Département de génie chimique et de génie biotechnologique, Université de Sherbrooke, Sherbrooke, Québec, Canada J1K 2R1 (Canada); Estel, Lionel [LSPC (Laboratoire de Sécurité des Procédés Chimiques). Institut National des Sciences Appliquées INSA Rouen (France); Braidy, Nadi [Département de génie chimique et de génie biotechnologique, Université de Sherbrooke, Sherbrooke, Québec, Canada J1K 2R1 (Canada)

    2015-01-15

    This paper presents the dielectric and magnetic properties, measured at 2.45 GHz, of a new nickel ferrite, NiFe{sub 2}O{sub 4}, synthetized by plasma technology. These properties were measured by the small perturbation method in a resonant cavity, from 293 to 513 K. Using these values, the adiabatic heating of nanoparticles of NiFe{sub 2}O{sub 4} under microwave irradiation was also modeled. The wave propagation equation (Maxwell's equation) coupled to the heat transfer in the solid was numerically solved. The influence of parameters such as the bed volume, its porosity, the microwave incident power or the microwave system geometry is discussed. This study demonstrates that NiFe{sub 2}O{sub 4} nanoparticles can be rapidly heated up to at least 513 K under microwaves and can probably achieve higher temperatures according to the thermal insulation. The magnetic contribution to heating overcomes the dielectric one in the explored temperature range. Very efficient energy yield (>90%) can then be achieved when the magnetic field position is centered over the bed. - Highlights: • A new nickel ferrite, NiFe{sub 2}O{sub 4}, was synthetized by plasma technology. • Its dielectric and magnetic properties were measured at 2.45 GHz. • The adiabatic heating of nanoparticles of NiFe{sub 2}O{sub 4} under microwave was modeled. • NiFe{sub 2}O{sub 4} nanoparticles can be rapidly heated up to at least 513 K. • The magnetic contribution to heating overcomes the dielectric one from 293 K to 513 K.

  1. Gradient heat flux measurement while researching of saturated water steam condensation

    Science.gov (United States)

    Mityakov, V. Y.; Sapozhnikov, S. Z.; Zainullina, E. R.; Babich, A. Y.; Milto, O. A.; Kalmykov, K. S.

    2017-11-01

    The heat flux measurement is used for research of heat transfer during condensation of saturated water steam at the surface of the tube made of stainless steel. A number of produced experimental setups allowed us to set different directions of movement of steam and cooling water, to change the space orientation of the tube, and also rotate the tube around its axis. In addition, the places of installation of the gradient heat flux sensors at internal and external surfaces of the tube were ranged. In the experiments we determined the local heat transfer coefficients, and their change along the length of the tube and for different values of the azimuthal angle. The obtained data allow to study in detail the formation of the film of condensate on the inside and outside surfaces of the tube and the heat transfer. The experimental results is in accordance with the classical ideas. The graphs show the pulsations of heat flux, which enable us to investigate non-stationary parameters of heat transfer during condensation. Experimental results differ from those calculated according to the Nusselt’s formula for 15% with standard uncertainty lower than 10%.

  2. Influence of heat and moisture exchanger use on measurements performed with manovacuometer and respirometer in healthy adults.

    Science.gov (United States)

    Lucato, Jeanette Janaina Jaber; Nogueira da Cunha, Thiago Marraccini; Rocha, Sara Solange Oliveira Costa; Palmieri de Carvalho, Fernanda Maria; Botega, Daniele Cristina; Torquato, Jamili Anbar; Gimenes, Ana Cristina; Righetti, Renato Fraga

    2015-01-01

    The use of evaluation tools such as the manovacuometer and respirometer is frequent and disinfection is usually limited to the external surfaces, which is insufficient and raises concerns because of the potential spread of infectious diseases. Hydrophobic heat and moisture exchangers (HME) are used in mechanical ventilation and have microbiological filters, which can possibly reduce contamination, increasing the safety of related procedures. It is unknown, however, if the addition of an exchanger affects the measurements obtained. Aim of this study was to verify if the use of an HME interferes in maximal inspiratory and expiratory pressures assessed using the manovacuometer and vital capacity evaluated using the respirometer in healthy adults. A controlled transversal trial was carried out. Twenty healthy young adults were included in the study. Vital capacity by respirometer and, maximal inspiratory pressure (MIP) and maximal expiratory pressure (MEP) were assessed with and without the use of HME. No significant difference was found between the values pre and post HME use in vital capacity measurements: (3878.8 ± 202.2 mL vs. 3925.5 ± 206.0 mL, p = 0.116) and the respiratory muscle strength measurements: MIP (-99.0 ± 8.9 vs -95.5 ± 9.0 cm H2O, p = 0.149) and MEP (92.5 ± 7.5 vs 92.5 ± 7.7 cm H2O, p = 1.0) respectively. We conclude that the use of HME does not modify the lung volumes or respiratory muscle strength, and can be used in order to reduce the occurrence of pulmonary infection.

  3. Calorimetry Minisensor for the Localised Measurement of Surface Heat Dissipated from the Human Body.

    Science.gov (United States)

    Socorro, Fabiola; Rodríguez de Rivera, Pedro Jesús; Rodríguez de Rivera, Manuel

    2016-11-06

    We have developed a calorimetry sensor that can perform a local measurement of the surface heat dissipated from the human body. The operating principle is based on the law of conductive heat transfer: heat dissipated by the human body passes across a thermopile located between the individual and a thermostat. Body heat power is calculated from the signals measured by the thermopile and the amount of power dissipated across the thermostat in order to maintain a constant temperature. The first prototype we built had a detection area measuring 6 × 6 cm², while the second prototype, which is described herein, had a 2 × 2 cm² detection area. This new design offers three advantages over the initial one: (1) greater resolution and three times greater thermal sensitivity; (2) a twice as fast response; and (3) it can take measurements from smaller areas of the body. The sensor has a 5 mW resolution, but the uncertainty is greater, up to 15 mW, due to the measurement and calculation procedure. The order of magnitude of measurements made in healthy subjects ranged from 60 to 300 mW at a thermostat temperature of 28 °C and an ambient room temperature of 21 °C. The values measured by the sensor depend on the ambient temperature and the thermostat's temperature, while the power dissipated depends on the individual's metabolism and any physical and/or emotional activity.

  4. Bayesian inferences of the thermal properties of a wall using temperature and heat flux measurements

    KAUST Repository

    Iglesias, Marco

    2017-09-20

    The assessment of the thermal properties of walls is essential for accurate building energy simulations that are needed to make effective energy-saving policies. These properties are usually investigated through in situ measurements of temperature and heat flux over extended time periods. The one-dimensional heat equation with unknown Dirichlet boundary conditions is used to model the heat transfer process through the wall. In Ruggeri et al. (2017), it was assessed the uncertainty about the thermal diffusivity parameter using different synthetic data sets. In this work, we adapt this methodology to an experimental study conducted in an environmental chamber, with measurements recorded every minute from temperature probes and heat flux sensors placed on both sides of a solid brick wall over a five-day period. The observed time series are locally averaged, according to a smoothing procedure determined by the solution of a criterion function optimization problem, to fit the required set of noise model assumptions. Therefore, after preprocessing, we can reasonably assume that the temperature and the heat flux measurements have stationary Gaussian noise and we can avoid working with full covariance matrices. The results show that our technique reduces the bias error of the estimated parameters when compared to other approaches. Finally, we compute the information gain under two experimental setups to recommend how the user can efficiently determine the duration of the measurement campaign and the range of the external temperature oscillation.

  5. Spectroscopic measurements of ion temperature in ATC Tokamak with RF and neutral beam heating

    Energy Technology Data Exchange (ETDEWEB)

    Suckewer, S.; Hinnov, E.

    1977-03-01

    Measurements of ion temperatures in the ATC Tokamak by means of Doppler broadening of various ion lines are described, and typical results presented for the various auxiliary heating experiments: compression, neutral beam, lower hybrid and ion cyclotron frequency heating. Radial resolution of the temperature measurements is achieved by utilizing spectrum lines of ions of different ionization potentials: OVII lambda 1623A, CV lambda 2271A and CIV lambda 1548A, which are emitted from regions of different electron temperature. Measurement at a given radial location is performed as a function of time by repeated scanning of the line contour in times 1.5 to 3.0 msec. The results indicate variations of heating efficiency with location and with power input level.

  6. Identifying and defining the dimensions of community capacity to provide a basis for measurement.

    Science.gov (United States)

    Goodman, R M; Speers, M A; McLeroy, K; Fawcett, S; Kegler, M; Parker, E; Smith, S R; Sterling, T D; Wallerstein, N

    1998-06-01

    Although community capacity is a central concern of community development experts, the concept requires clarification. Because of the potential importance of community capacity to health promotion, the Division of Chronic Disease Control and Community Intervention, Centers for Disease Control and Prevention (CDC), convened a symposium in December 1995 with the hope that a consensus might emerge regarding the dimensions that are integral to community capacity. This article describes the dimensions that the symposium participants suggested as central to the construct, including participation and leadership, skills, resources, social and interorganizational networks, sense of community, understanding of community history, community power, community values, and critical reflection. The dimensions are not exhaustive but may serve as a point of departure to extend and refine the construct and to operationalize ways to assess capacity in communities.

  7. Measurements of ion energies during plasma heating of the Proto-MPEX High Intensity Plasma Source

    Science.gov (United States)

    Caughman, J. B. O.; Goulding, R. H.; Biewer, T. M.; Bigelow, T. S.; Caneses, J.; Diem, S. J.; Green, D. L.; Isler, R. C.; Rapp, J.; Piotrowicz, P.; Beers, C. J.; Kafle, N.; Showers, M. A.

    2017-10-01

    The Prototype Materials Plasma Exposure eXperiment (Proto-MPEX) is a linear high-intensity RF plasma source that combines a high-density helicon plasma generator with ion and electron heating sections. It is being used to study the physics of heating over-dense plasmas in a linear configuration with the goal of delivering a plasma heat flux of 10 MW/m2 at a target. The helicon plasma is produced by coupling 13.56 MHz RF power at levels >100 kW. Additional heating is provided by ion cyclotron heating (ICH) ( 25 kW) and electron Bernstein wave (EBW) heating ( 25 kW) at 28 GHz. Measurements of the ion energy distribution with a retarding field energy analyzer (RFEA) show an increase in ion energies in the edge of the plasma when ICH is applied, which is consistent with COMSOL modeling of the power deposition from the antenna. Views of the target plate with an infrared camera show an increase in the surface temperature at large radii during ICH, and these areas map back to magnetic field lines near the antenna. The change in the power deposition at the target during ICH is compared with Thomson Scattering and RFEA measurements near the target. ORNL is managed by UT-Battelle, LLC, for the U.S. DOE under contract DE-AC-05-00OR22725.

  8. Thermal substitution and aerobic efficiency: measuring and predicting effects of heat balance on endotherm diving energetics.

    Science.gov (United States)

    Lovvorn, J R

    2007-11-29

    For diving endotherms, modelling costs of locomotion as a function of prey dispersion requires estimates of the costs of diving to different depths. One approach is to estimate the physical costs of locomotion (Pmech) with biomechanical models and to convert those estimates to chemical energy needs by an aerobic efficiency (eta=Pmech/Vo2) based on oxygen consumption (Vo2) in captive animals. Variations in eta with temperature depend partly on thermal substitution, whereby heat from the inefficiency of exercising muscles or the heat increment of feeding (HIF) can substitute for thermogenesis. However, measurements of substitution have ranged from lack of detection to nearly complete use of exercise heat or HIF. This inconsistency may reflect (i) problems in methods of calculating substitution, (ii) confounding mechanisms of thermoregulatory control, or (iii) varying conditions that affect heat balance and allow substitution to be expressed. At present, understanding of how heat generation is regulated, and how heat is transported among tissues during exercise, digestion, thermal challenge and breath holding, is inadequate for predicting substitution and aerobic efficiencies without direct measurements for conditions of interest. Confirming that work rates during exercise are generally conserved, and identifying temperatures at those work rates below which shivering begins, may allow better prediction of aerobic efficiencies for ecological models.

  9. Measuring convective heat transfer coefficients of nanofluids over a circular fine wire maintaining a constant temperature

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Shinpyo [Kyonggi Univ., Suwon (Korea, Republic of)

    2012-01-15

    This paper describes a measuring apparatus that can be used to appraise the effectiveness of nanofluids as new heat transfer enhancing fluids. A couple of apparatuses using fine hot wires as sensors have been proposed for this purpose; however, they have a technical weakness related to the uncertain working conditions of the sensor. The present method used the convective heat transfer coefficient from a hot wire as an indication of the heat transfer effectiveness of the nanofluid, where the temperature of the wire remains constant during the experiment. The operating principle and experimental procedure are explained in detail, and the validity of the system is tested with pure base fluids. The effects of particle concentration, velocity, and temperature on the heat transfer coefficients of the nanofluids are discussed comprehensively using the experimental data for graphite nanolubrication oil.

  10. X-ray reflectivity measurement of interdiffusion in metallic multilayers during rapid heating

    Science.gov (United States)

    Liu, J. P.; Kirchhoff, J.; Zhou, L.; Zhao, M.; Grapes, M. D.; Dale, D. S.; Tate, M. D.; Philipp, H. T.; Gruner, S. M.; Weihs, T. P.; Hufnagel, T. C.

    2017-01-01

    A technique for measuring interdiffusion in multilayer materials during rapid heating using X-ray reflectivity is described. In this technique the sample is bent to achieve a range of incident angles simultaneously, and the scattered intensity is recorded on a fast high-dynamic-range mixed-mode pixel array detector. Heating of the multilayer is achieved by electrical resistive heating of the silicon substrate, monitored by an infrared pyrometer. As an example, reflectivity data from Al/Ni heated at rates up to 200 K s−1 are presented. At short times the interdiffusion coefficient can be determined from the rate of decay of the reflectivity peaks, and it is shown that the activation energy for interdiffusion is consistent with a grain boundary diffusion mechanism. At longer times the simple analysis no longer applies because the evolution of the reflectivity pattern is complicated by other processes, such as nucleation and growth of intermetallic phases. PMID:28664887

  11. X-ray reflectivity measurement of interdiffusion in metallic multilayers during rapid heating.

    Science.gov (United States)

    Liu, J P; Kirchhoff, J; Zhou, L; Zhao, M; Grapes, M D; Dale, D S; Tate, M D; Philipp, H T; Gruner, S M; Weihs, T P; Hufnagel, T C

    2017-07-01

    A technique for measuring interdiffusion in multilayer materials during rapid heating using X-ray reflectivity is described. In this technique the sample is bent to achieve a range of incident angles simultaneously, and the scattered intensity is recorded on a fast high-dynamic-range mixed-mode pixel array detector. Heating of the multilayer is achieved by electrical resistive heating of the silicon substrate, monitored by an infrared pyrometer. As an example, reflectivity data from Al/Ni heated at rates up to 200 K s-1 are presented. At short times the interdiffusion coefficient can be determined from the rate of decay of the reflectivity peaks, and it is shown that the activation energy for interdiffusion is consistent with a grain boundary diffusion mechanism. At longer times the simple analysis no longer applies because the evolution of the reflectivity pattern is complicated by other processes, such as nucleation and growth of intermetallic phases.

  12. Quench Limit Model and Measurements for Steady State Heat Deposits in LHC Magnets

    CERN Document Server

    Bocian, D; Siemko, A

    2009-01-01

    A quench, transition of a conductor from the superconducting to the normal conducting state, occurs irreversibly in accelerator magnets if one of the three parameters: temperature, magnetic field or current density, exceeds its critical value. The protons lost from the beam and impacting on the vacuum chamber, create a secondary particle shower that deposes its energy in the magnet coil. Energy deposited in the superconductor by these particles can provoke quenches that can be detrimental for the accelerator operation. A network model is developed to study the thermodynamic behavior of the LHC magnets. The results of the heat flow simulation in the main dipole and quadrupole LHC magnets calculated by means of the network model were validated with measurements performed at superfluid helium temperatures in the CERN magnet test facility. A steady state heat flow was introduced in the magnet coil by using a dedicated internal heating apparatus (IHA) installed inside the magnet cold bore. The value of the heat so...

  13. Thermolysis, nonisothermal decomposition kinetics, specific heat capacity and adiabatic time-to-explosion of [Cu(NH3)4](DNANT)2 (DNANT= dinitroacetonitrile).

    Science.gov (United States)

    Zhang, Yu; Wu, Hao; Xu, Kangzhen; Zhang, Wantao; Ren, Zhaoyu; Song, Jirong; Zhao, Fengqi

    2014-02-20

    A new energetic copper complex of dinitroacetonitrile (DNANT), [Cu(NH3)4](DNANT)2, was first synthesized through an unexpected reaction. The thermal decomposition of [Cu(NH3)4](DNANT)2 was studied with DSC and TG/DTG methods. The gas products were analyzed through a TG-FTIR-MS method. The nonisothermal kinetic equation of the exothermic process is dα/dT = 10(10.92)/β4(1 - α)[-ln(1 - α)](3/4) exp(-1.298 × 10(5)/RT). The self-accelerating decomposition temperature and critical temperature of thermal explosion are 217.9 and 221.0 °C. The specific heat capacity of [Cu(NH3)4](DNANT)2 was determined with a micro-DSC method, and the molar heat capacity is 512.6 J mol(-1) K(-1) at 25 °C. Adiabatic time-to-explosion of Cu(NH3)4(DNANT)2 was also calculated to be about 137 s.

  14. [Anthropometric measures of central abdominal fat and discriminant capacity for metabolic syndrome in a Spanish population].

    Science.gov (United States)

    Bellido, Diego; López de la Torre, Martín; Carreira, José; de Luis, Daniel; Bellido, Virginia; Soto, Alfonso; Luengo, Luis M; Hernández, Antonio; Vidal, Josep; Becerra, Antonio; Ballesteros, María

    2013-01-01

    The metabolic syndrome (MS) carries an increased risk of cardiovascular disease and diabetes mellitus. Insulin resistance is probably the mechanism underlying the changes detected in lipid and carbohydrate metabolism in these patients, who have, as a common anthropometric feature, a predominantly increased abdominal fat distribution. A total of 3316 patients were studied, of whom 63.40% were female and 36.60 male, with a mean age of 42.36±14.63 years, and a body mass index (BMI) of 32.76±6.81kg/m(2). Weight, height and waist circumference (CC) were measured using standard techniques. The waist/height (ICA) was calculated using two indicators, expressed as waist in cm divided by height in m(2), and as waist divided by height, both in cm. The prevalence of metabolic syndrome in the sample was 33.70%. In order to assess the predictive ability of BMI, ICA and CC to detect the existence of MS, receiver operating curves (ROC) were constructed and the areas under the curve (AUC) calculated for each anthropometric parameter. An AUC of 0.724 (95%CI: 0.706 to 0.742), P<.001, was obtained for CC, 0.709 (95%CI: 0.691 to 0.728), P<.001 for ICA with height in m(2), and 0.729 (95%CI: 0.711 to 0.747), P<.001 for ICA with height in cm, and for the BMI it was 0.680 (95%CI 0.661-0.699), P<.001. Anthropometric indices that assess abdominal fat distribution have a better predictive capacity for detecting MS, compared to total adiposity indicators such as BMI. Copyright © 2013 Elsevier España, S.L. y SEA. All rights reserved.

  15. Comparison of Conventional and Microwave Assisted Heating on Carbohydrate Content, Antioxidant Capacity and Postprandial Glycemic Response in Oat Meals

    Directory of Open Access Journals (Sweden)

    Joanna Harasym

    2018-02-01

    Full Text Available Minimally processed cereal breakfast products from whole grain entered the market due to consumer demand of more nutritional food with more controlled sugar release. However, the subsequent processing of such products with different cooking methods in the consumer’s kitchen may lead to significant differentiation of their nutritional value. Therefore, the evaluation of the impact of frequently used cooking methods on a final quality of breakfast cereals meal is needed. The present study investigates how the two different methods of heating, conventional and microwave (MW assisted, affect the carbohydrate content, profile and resulting glycemic index of so prepared food as well as the antioxidant activity of meals. Two products available on the market—oat bran and flakes—were used. The highest starch content in fluid phase of oatmeal was detected in samples heated for 3 min with microwaves, regardless the type. The lowest starch content was obtained for 5 min MW heated flakes sample. The total content of glucose was about 1.5 times lower in bran vs. flakes oatmeal. The highest β-glucan content in fluid fraction was also observed for bran meal but its release was independent of applied conditions.

  16. When evidence of heat-related vulnerability depends on the contrast measure

    Science.gov (United States)

    Benmarhnia, Tarik; Kaufman, Jay S.

    2017-02-01

    Many studies assessing which population subgroups are more vulnerable to heat-related mortality and morbidity have been conducted in recent years. However, given the non-linear (U or J shaped) relationship of temperature with mortality and morbidity, they generally consider only a single contrast measure to report evidence of heat-related vulnerability, despite the possibility that vulnerability depends on the selected contrast measure. In this manuscript, we highlight the importance of considering such issue in further studies by providing evidence for and against heat-related vulnerability using two different temperature contrast measures. We conducted time series analyses to characterize the association between mortality and mean daily temperature in Montreal, Canada (1990-2010). We used age (≥65 vs. 0-64 years) as the effect modifier in stratified analyses. We assessed the presence of effect modification using Cochran Q tests. As contrast measures, we used (1) the percentage change in the outcome above 25 °C, obtained through spline functions showing a linear relationship after this threshold and (2) a comparison of two percentiles (26 vs. 20 °C) of the temperature. We found that evidence of effect modification depended on the contrast measure used. We encourage researchers aiming to identify populations more vulnerable to heat to perform sensitivity analyses using different contrast measures.

  17. High speed infrared camera diagnostic for heat flux measurement in NSTX.

    Science.gov (United States)

    Ahn, J-W; Maingi, R; Mastrovito, D; Roquemore, A L

    2010-02-01

    A new high speed infrared camera has been successfully implemented and produced first set of heat flux measurements on the lower divertor tiles in the NSTX tokamak. High spatial and temporal resolutions, 6.4 mm and 1.6-6.3 kHz, respectively, enable us to investigate detailed structure of heat flux deposition pattern caused by transient events such as edge localized modes. A comparison of the data with a slow infrared camera viewing the same region of interest shows good agreement between the two independent measurements. Data analysis for various plasma conditions is in progress.

  18. Review of Nuclear Heating Measurement by Calorimetry in France and USA

    Science.gov (United States)

    Reynard-Carette, C.; Kohse, G.; Brun, J.; Carette, M.; Volte, A.; Lyoussi, A.

    2018-01-01

    This paper gives a short review of sensors dedicated to measuring nuclear heating rate inside fission reactors in France and USA and especially inside Material Testing Reactors. These sensors correspond to heat flow calorimeters composed of a single calorimetric cell or of two calorimetric cells at least with a reference cell to obtain a differential calorimeter. The aim of this paper is to present the common running principle of these sensors and their own special characteristics through their design, calibration methods, and in-pile measurement techniques, and to describe multi-sensor probes including calorimeters.

  19. Accuracy of soil heat flux plate measurements in coarse substrates - Field measurements versus a laboratory test

    NARCIS (Netherlands)

    Weber, S.; Graf, A.; Heusinkveld, B.G.

    2007-01-01

    The in-situ performance of heat flux plates within coarse porous substrates might be limited due to poor contact between plate and substrate. We tested this behaviour with a simple laboratory set-up. Two test substrates were placed above a reference material of known thermal conductivity between a

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

    Directory of Open Access Journals (Sweden)

    Gueton O.

    2013-03-01

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