Showing papers on "Calorimeter published in 1990"
TL;DR: In this article, the authors used a non-linear regression fitting of the model of the calorimeter to an extensive set of temperature time measurements to evaluate the rate of enthalpy generation in the electrolysis of light and heavy water.
119 citations
TL;DR: In this article, a phase transition thermometer combined with a SQUID readout was used for low temperature calorimetric particle detectors, achieving an energy resolution of ΔE E = 1.2% for irradiation with 5.8 MeV α -particles.
64 citations
TL;DR: In this article, the isobaric heat capacity of liquid HFC-134a, which is a prospective alternative to CFC-12, has been measured by using a flow calorimeter.
Abstract: The isobaric heat capacity, C p , of liquid HFC-134a, which is a prospective alternative to CFC-12, has been measured by using a flow calorimeter. The C p of saturated liquid, C p ', has been determined on the basis of the data measured in the compressed liquid phase, and a correlation of C p ' has also been developed
45 citations
TL;DR: In this article, the heat contents of the III-V compounds of AlN, GaN, AlP, GaP, InP, AlAs, GaAs, InAs, AlSb, GaSb and InSb were measured over the temperature range 650 to 1550K using a drop calorimeter.
42 citations
01 May 1990-Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment
TL;DR: The OPAL end cap electromagnetic calorimeter as mentioned in this paper consists of leadglass instrumented with vacuum photo triodes and is subject to magnetic fields up to 10 T. The response to hadrons is also discussed.
Abstract: A description is given of the OPAL end cap electromagnetic calorimeters which consist of leadglass instrumented with vacuum photo triodes Test results are presented showing linearity, energy and position resolution measured in an electron beam whilst the calorimeter is subject to magnetic fields up to 10 T The response to hadrons is also discussed Finally, radiation damage and recovery of the leadglass is reported
32 citations
TL;DR: The heat capacity of 2-amino-2-methyl-1,3-propanediol was measured from 280 K to the melting point by means of an automated adiabatic calorimeter.
31 citations
15 Jun 1990-Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment
TL;DR: In this paper, a 1278 element lead-glass calorimeter has been constructed to measure photons in the energy range from 0.2 to 20 GeV for the WA80 fixed-target heavy-ion experiment at the CERN-SPS.
Abstract: For the WA80 fixed-target heavy-ion experiment at the CERN-SPS, a 1278 element lead-glass calorimeter has been constructed to measure photons in the energy range from 0.2 to 20 GeV. We describe the design of the detector, the achieved energy and position resolution, the gain monitoring system and the performance of the high-energy photon trigger. The quality of photon identification and π0 invariant mass reconstruction is discussed.
29 citations
TL;DR: In this article, a monochromatic light beam is split into two parts which are introduced into calorimetric vessels by use of optical light guides, and the two vessels are positioned in separate twin microcalorimeters placed in the same thermostatic bath.
21 citations
15 Apr 1990-Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment
TL;DR: In this article, the energy and spatial resolution of a krypton calorimeter with cathode strips of 10 mm has been measured with positrons, achieving a rms of 5.7% at E = 130 MeV and 1.7 % at E= 1200 MeV, respectively.
Abstract: Effects determining the energy and spatial resolution of a calorimeter based on liquid krypton have been studied. With cathode strips of 10 mm a spatial resolution of 0.4 mm has been obtained in a cosmic rays test. The energy resolution of the calorimeter (0.4 ton of krypton) has been measured with positrons, achieving a rms of 5.7% at E = 130 MeV and 1.7% at E = 1200 MeV. The measurements are compared to Monte Carlo simulations.
18 citations
TL;DR: In this paper, a combination of thin plates of low-Z and high-Z materials used as absorbers enables the reduction of the calorimeter response to the electromagnetic component of the incoming hadronic showers (the local hardening effect).
18 citations
TL;DR: In this article, a glass transition related to the proton configurational mode in the hydrogen-bonded host was observed around 90 K. This glass transition was similar to the one observed previously for the structure II tetrahydrofuran hydrate but showed a wider distribution of relaxation times.
Abstract: The heat capacity of structure I ethylene oxide clathrate hydrate EO-6.86 H2O was measured in the temperature range 6–300 K with an adiabatic calorimeter. The temperature and enthalpy of congruent melting were determined to be (284.11 ± 0.02) K and 48.26 kJ mol−1, respectively. A glass transition related to the proton configurational mode in the hydrogen-bonded host was observed around 90 K. This glass transition was similar to the one observed previously for the structure II tetrahydrofuran hydrate but showed a wider distribution of relaxation times. The anomalous heat capacity and activation enthalpy associated with the glass transition were almost the same as those for THF-hydrate.
TL;DR: In this paper, a dual sample differential scanning calorimeter with auto sampler and liquid nitrogen cooling accessary-IL was used to measure the heat capacity of selenium, aluminium, quartz, polystyrene, sodium chloride and polyvinyl chloride.
Abstract: A prior study of single-run differential scanning calorimetry that leads directly to heat capacity results is extended to low temperatures (180 K). The instrument considered was the duPont dual sample differential scanning calorimeter with auto sampler and liquid nitrogen cooling accessary-IL. The major error is caused by the low temperature isotherm. After optimizing all parameters, heat capacities of selenium, aluminium, quartz, polystyrene, sodium chloride were measured between 180 to 370 K. The root mean square error of all measurements on comparison with well established adiabatic calorimetry is ±2.9%
01 Mar 1990
TL;DR: In this article, heat capacity measurements have been made on a synthetic sample of langbeinite, K2Mg2(SO4)3, from 13 to 342 K in an adiabatic calorimeter.
Abstract: Heat capacity measurements have been made on a synthetic sample of langbeinite, K2Mg2(SO4)3, from 13 to 342 K in an adiabatic calorimeter Three phase transitions, at 510, 549 and 638 K, have been observed in this material Our study is the first to report the existence of such phase transitions in K2Mg2(S04)3 and disputes predictions that none would take place below 77 K Two models which have been proposed to explain the transition in potassium langbeinites are discussed in light of these results
01 Jan 1990-International Journal of Radiation Applications and Instrumentation. Part C. Radiation Physics and Chemistry
TL;DR: The graphite or metal calorimeters are used to make absolute dosimetric measurements of high-energy electron beams, which are then used to calibrate several types of dosimeters for high-dose applications such as medical-product sterilization, polymer modification, food processing, or electronic-device hardness testing as discussed by the authors.
TL;DR: In this article, the temperature and enthalpy of a pure zinc specimen chosen from NIST SRM 2221a have been measured for the first time simultaneously in a high-precision method of mixtures isothermal phase-change calorimeter.
TL;DR: In this paper, a description of a calorimetric system for adsorption of gases on thin metal films is presented, which operates over pressure intervals from a few nanopascals to about one hundred millipascals and over temperature intervals from 280 to 370 K.
Journal Article•
TL;DR: A transportable, whole body indirect calorimeter, designed for use in the tropics, was built to study energy expenditure of people having chronically or acutely low levels of food intake and it will help to determine energy adaptations made by individuals with restricted food intake.
Abstract: A transportable, whole body indirect calorimeter, designed for use in the tropics, is described. The calorimeter was built to study energy expenditure of people having chronically or acutely low levels of food intake, and it will help to determine energy adaptations made by individuals with restricted food intake. The calorimeter comprises two units: a 27 m3 ventilated chamber connected to an office housing control and monitoring equipment. The system also allows the experimenter to assess the rate of energy expenditure by means of a ventilated hood or a baby respiration chamber. The incoming air flow rate is variable and is typically set at approximately 30 l/min. Carbon dioxide production (VCO2) and oxygen consumption (VO2) are continuously monitored by means of differential gas analysers via a computerized data acquisition unit. Gas production/consumption rates are measured with a delay of 80 s, the complete response to step changes in VCO2 or VO2 consumption being calculated over 15 min using the rate of change terms in the gas exchange equations. The total electrical power required for the whole system is 12 kW. The calorimeter has been functioning for nearly 4 years in a rural village of The Gambia during which ambient temperatures have ranged from 16 to 44 degrees C and dewpoints from -8 to 24 degrees C. The performance and accuracy of the calorimeter were tested using 20 per cent CO2 in N2 infusion and butane burning. Agreement between the theoretical and the measured values was found to be 99 per cent for VO2 and 100 per cent for VCO2 with a precision for both gases of +/- 10 ml/min over a 1-h period.
TL;DR: In this paper, a calorimeter is described to measure the increase in enthalpy of metallic materials from room temperature (T0=300 K) to at least the melting temperature Tm, with Tm up to 2500 K.
Abstract: A calorimeter is described to measure the increase in enthalpy, ΔH(T)=H(T)−H(T0), of metallic materials from room temperature (T0=300 K) to at least the melting temperature Tm, with Tm up to 2500 K. Heating rates are φ=dT/dt between about 105 and 107 K/s; accuracies are better than 2% in ΔH, and better than 5% in T.
TL;DR: In this paper, the authors presented an outline for the data analysis of single-run heat capacity measurments by dual sample DSCs with the following features: 1. Heat flow correction by subtracting the contribution due to the sample pan, including correction for mismatched pan masses.
Abstract: An outline for the data analysis of single-run heat capacity measurments by dual sample DSC is presented with the following features: 1. Heat flow correction by subtracting the contribution due to the sample pan, including correction for mismatched pan masses. 2. Heat flow and temperature correction with a nonlinear temperature calibration, temperature lag correction, and heating rate correction. 3. Calculation of the cell constants for both cell positions and evaluation of the asymmetry factor between cell positions A and B. 4. Heat capacity calibration and calculation with slope and asymmetry correction. 5. Calculation of heat capacity for multiple runs. 6. Data curve fitting for heat capacity.
TL;DR: A new design of flow calorimeter has been constructed and used to measure both the heat capacity and the Joule-Thomson coefficient of ethanol vapour as discussed by the authors, which was used to evaluate the performance of the flow calors.
TL;DR: In this article, the formation of palladium hydride and deuteride by electrolysis has been studied with high precision calorimetry using sealed cells within-situ recombination of gaseous products as well as open cells.
Abstract: The formation of palladium hydride and deuteride by electrolysis has been studied with high precision calorimetry using sealed cells within-situ recombination of gaseous products as well as open cells. Palladium electrodes prepared by different methods were studied. With sealed cells of our design in the heat flow isothermal calorimeter, the uncertainies associated with the gas evolution, evaporation, entrainment, and side reactions were effectively eliminated. No unexpected excess heat was observed within energy balance error of about 2%.
TL;DR: A flow calorimeter for measuring enthalpy increments of fluids from 200 to 500 K and at pressures to 20 MPa has been constructed in this article, which was tested with measurements on water, p-xylene, and n-heptane.
TL;DR: The enthalpy increments of metallic silver have been measured from 560 to 900 K in a diphenyl ether calorimeter as mentioned in this paper, and the results can be represented within 0.5% by the equation {HXXX(T − HXXX (298.15 K)} (J mol−1) = 23.2625T + 3.3164 × 10−3T2 − 7230.5
TL;DR: In this paper, an experimental evidence has been found for a filtering effect on the soft electron component in electromagnetic showers when combinations of low-Z and high-Z materials are used as absorbers, making it possible to achieve the compensation condition in a Si/Fe+Pb calorimeter with an effective interaction length almost equal to that of Fe.
Abstract: Experimental evidence has been found for a filtering effect on the soft electron component in electromagnetic showers when combinations of low-Z and high-Z materials are used as absorbers. The filtering effect can be fully exploited to reduce the electromagnetic calorimeter response, making it possible to achieve the compensation condition in a Si/Fe+Pb calorimeter with an effective interaction length almost equal to that of Fe. The action of Fe on Pb, by modifying the critical energy during the electromagnetic shower development, leads to a yield of soft electrons (and very few photons) that are stopped in subsequent absorber layers and/or absorbed by the G10 plates. Recent measurements performed with an enlarged Si/Fe+Pb calorimeter support the idea; the authors have shown that an electromagnetic energy smaller than the hadronic energy is possible once particular FePb configurations are used. >
15 Sep 1990-Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment
TL;DR: In this paper, the energy and spatial resolution of a 40 l liquid-xenon calorimeter was measured and the details of construction and running of such a device were discussed.
Abstract: The energy and spatial resolution of a 40 l liquid-xenon calorimeter was measured. For electrons in the energy region 1–6 GeV the resolutions are σE/E = 3.4/√E (%), σx = 4.6/√E (mm). The details of construction and running of such a device are discussed.
TL;DR: In this paper, an analysis of the performance of an ideal ac calorimeter limited only by thermodynamic noise is presented, which is designed for studies of the heat capacity of monolayers and multilayers of atoms and molecules adsorbed on a variety of surfaces.
Abstract: An analysis is presented of the performance of an ideal ac calorimeter limited only by thermodynamic noise. A calorimeter based on this analysis is described which is designed for studies of the heat capacity of monolayers and multilayers of atoms and molecules adsorbed on a variety of surfaces. The calorimeter consists of Ge:Ga thermometers and NiCr heaters mounted on one side of a sapphire substrate, with an evaporated film deposited on the other side. The calorimeter is mounted on a 4He cold finger in a UHV system allowing heat capacity measurements down to 1.6 K. In order to verify the performance of the calorimeter, measurements have been made of the heat capacity of 25‐μg samples of indium, and of submonolayer coverages of 4He on sapphire. The measured sensitivity corresponds to <10−2 monolayers of 4He adsorbed on the surface of the calorimeter in the gas phase.
TL;DR: In this paper, a twin-cell heat conduction calorimeter was used, rather than the quasi-adiabatic instrumentation of the original investigation, to verify the caloric claims by Fleischmann and Pons.
Abstract: This paper reports on calorimetric experiments conducted to verify the caloric claims by Fleischmann and Pons. A twin-cell heat conduction calorimeter was used, rather than the quasi-adiabatic instrumentation of the original investigation. Under similar electrochemical conditions, the output of heat powers from experimental cells of Pd in 0.1M LiOD/D{sub 2}O and that from control cells of Pd in 0.1M LiOH/H{sub 2}O and Pt in 0.1M LiOD/D{sub 2}O were all in close agreement with input heat powers using simple theory. These results show no anomalous excess heat as claimed.
TL;DR: A set of calorimeters using silicon diode sampling has been constructed to provide the small angle electromagnetic calorimetry for SLD (Stanford Linear Collider Large Detector) at SLAC as discussed by the authors.
Abstract: A set of calorimeters using silicon diode sampling has been constructed to provide the small angle electromagnetic calorimetry for SLD (Stanford Linear Collider Large Detector) at SLAC (Stanford Linear Accelerator Center). The luminosity monitor and small angle tagger (LMSAT) and the medium angle silicon calorimeter (MASC) measure the direction and energy of electrons and photons in the region of 23-190 mrd from the SLD beam axis. The calorimeter uses nearly two square meters of silicon diodes segmented into cells approximately one square centimeter in area. One LMSAT module has been tested with electrons at the Brookhaven National Laboratory. The stack consists of 23 layers of silicon diodes separated by about one-radiation-length (3.5-mm) layers of tungsten alloy. The results of this beam test, including energy and spatial resolution, are presented. >
15 Apr 1990-Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment
TL;DR: In this article, the authors describe details of the DO calorimeter modules and the data acquisition system and present results about the resolution of "electromagnetic" and "hadronic" modules, as obtained from exposure to 10-150 GeV electrons and pions in a test beam at Fermilab.
Abstract: We describe details of the DO calorimeter modules and the data acquisition system. We present results about the resolution of “electromagnetic” and “hadronic” modules, as obtained from exposure to 10–150 GeV electrons and pions in a test beam at Fermilab. Results on the position resolution for electromagnetic showers are also given.
TL;DR: In this article, the enthalpies of combustion and vaporization of 1,3 and 1,4-dichlorobutanes were measured in a tantalum-lined rotation bomb calorimeter and an LKB vaporization calorometer and from these values the gaseous enthalps of formation of the compounds were calculated as 194.98 ± 1.78 and 183.40± 1.94 kJ mol−1, respectively.