Showing papers on "Calorimeter published in 2015"

Characterization of a 6 kW high-flux solar simulator with an array of xenon arc lamps capable of concentrations of nearly 5000 suns.

Abstract: A systematic methodology for characterizing a novel and newly fabricated high-flux solar simulator is presented. The high-flux solar simulator consists of seven xenon short-arc lamps mounted in truncated ellipsoidal reflectors. Characterization of spatial radiative heat flux distribution was performed using calorimetric measurements of heat flow coupled with CCD camera imaging of a Lambertian target mounted in the focal plane. The calorimetric measurements and images of the Lambertian target were obtained in two separate runs under identical conditions. Detailed modeling in the high-flux solar simulator was accomplished using Monte Carlo ray tracing to capture radiative heat transport. A least-squares regression model was used on the Monte Carlo radiative heat transfer analysis with the experimental data to account for manufacturing defects. The Monte Carlo ray tracing was calibrated by regressing modeled radiative heat flux as a function of specular error and electric power to radiation conversion onto measured radiative heat flux from experimental results. Specular error and electric power to radiation conversion efficiency were 5.92 ± 0.05 mrad and 0.537 ± 0.004, respectively. An average radiative heat flux with 95% errors bounds of 4880 ± 223 kW ⋅ m(-2) was measured over a 40 mm diameter with a cavity-type calorimeter with an apparent absorptivity of 0.994. The Monte Carlo ray-tracing resulted in an average radiative heat flux of 893.3 kW ⋅ m(-2) for a single lamp, comparable to the measured radiative heat fluxes with 95% error bounds of 892.5 ± 105.3 kW ⋅ m(-2) from calorimetry.

Development of a scintillation light detector for a cryogenic rare-event-search experiment

Abstract: We developed a light detector to measure scintillation light from a crystal utilized in heat and light measurements at low temperatures for a rare-event-search experiment. A 2-in. Ge wafer was used as the light absorber, while a metallic magnetic calorimeter was employed to read out the temperature increase of the absorber. The light detector was tested at 25–100 mK using a cryogen-free adiabatic demagnetization refrigerator. The performance in terms of energy resolution, rise time and signal amplitude was measured using radioactive sources with a consideration of the absorption position on the wafer. The light detector was used to measure the scintillation light of a CaMoO4 crystal at mK temperatures. We also discuss for the potential application of this detector in a neutrinoless double-beta decay experiment.

Phase Transitions of Binary Lipid Mixtures: A Combined Study by Adiabatic Scanning Calorimetry and Quartz Crystal Microbalance with Dissipation Monitoring

Abstract: The phase transitions of binary lipid mixtures are studied by a combination of Peltier-element-based adiabatic scanning calorimetry (pASC) and quartz crystal microbalance with dissipation monitoring (QCM-D). pASC, a novel type of calorimeter, provides valuable and unambiguous information on the heat capacity and the enthalpy, whereas QCM-D is proposed as a genuine way of determining phase diagrams by analysing the temperature dependence of the viscosity. Two binary mixtures of phospholipids with the same polar head and differing in the alkyl chain length, DMPC

Air Injection for Enhanced Oil Recovery: In Situ Monitoring the Low-Temperature Oxidation of Oil through Thermogravimetry/Differential Scanning Calorimetry and Pressure Differential Scanning Calorimetry

Abstract: Low-temperature oxidation (LTO) of oil plays an important role in air-injection based oil recovery processes. Systematic investigations on the regularities of LTO reactions, especially those decoupled with the influences of mass transfer, were highly expected to improve field application and even to develop new strategies for heavy oil recovery. In this contribution, both thermogravimetry/differential scanning calorimeter and pressure differential scanning calorimeter were employed as microreactors to in situ monitoring the heat release and mass loss performances of the LTO process under different oxygen partial pressures. The total amount of heat resulted from LTO reactions of oil was observed in a linear relationship with oxygen partial pressure. A one-step reaction model was proposed to simulate the low-temperature mass loss behavior. The kinetic parameters were calculated based on the Arrhenius expression and the assumption of distributed activation energy. These results indicated the feasibility of i...

Upscaling semi-adiabatic measurements for simulating temperature evolution of mass concrete structures

Abstract: Thermal analysis of mass concrete is often carried out through finite element (FE) analysis. The heat release rate in a material point can be determined from a small-scale isothermal calorimeter. Nonetheless, isothermal calorimeter is generally an expensive device and lacks practicality. In that light, this paper proposes a low-cost semi-adiabatic calorimeter setup complemented with a FE analysis. Such a combination provides evolution of hydration heat under isothermal temperature and enables upscaling to the temperature evolution in mass concrete structures. The upscaling process is demonstrated on three mass concrete blocks. Initially, semi-adiabatic measurements start on 14 dm3 concrete cube to identify the heat release rate. Next, the calibrated hydration model is upscaled and validated on a 1.0 m3 concrete cube and two mass concrete foundation blocks with 511 and 1,050 m3. The validation proves successfully the upscaling approach; also, the same temperature-dependent hydration kinetics performs well from small to large scales.

Towards FAIR: first measurements of metallic magnetic calorimeters for high-resolution x-ray spectroscopy at GSI

Abstract: Metallic magnetic calorimeters are energy dispersive particle detectors that are operated at temperatures below . Applied to x-ray spectroscopy they combine the high energy resolution of crystal spectrometers with the large energy bandwidth of semiconductor detectors. After the absorption of a photon its energy is converted into heat. A paramagnetic alloy converts the temperature change into a change of magnetization that is read out by a sensitive superconducting quantum interference device magnetometer. With such a metallic magnetic calorimeter we performed two successful measurements at the internal gas target of the experimental storage ring at GSI. In the first beamtime lithium-like Au-ions were targeted on a N2 and a Xe gas target, respectively. In the second beamtime we observed a projectile beam of bare Xe ions interacting with a Xe gas target. In both experiments we achieved an energy resolution below from to . We were able to detect K-lines of Xe ions of different charge states, including the Lyman series up to Ly-η and could resolve the Ly-β-doublet in H-like Xe.

Validity Test of a New Open-Circuit Indirect Calorimeter.

Abstract: Background: Indirect calorimetry is an accurate way to measure resting metabolic rate. The Deltatrac Metabolic Monitor is considered a criterion standard but is no longer manufactured. New-generation indirect calorimeters have been introduced, but there are limited published validation data comparing these devices to criterion instruments. Materials and Methods: A prospective, observational, N-of-1 trial was conducted to validate a new-generation indirect calorimeter against a gold standard device. This design was chosen to minimize and define the degree of biological variation, thus focusing on variation due to the devices. Measurements of gas exchange using both indirect calorimeters were conducted daily for 10 consecutive days. Another set of measurement pairs was conducted using just the criterion device for 10 days. Ninety-five percent confidence intervals of differences were used to test for bias. Precision was defined as repeat measures with one device falling within 5% of the other at least 90% of...

On timing properties of LYSO-based calorimeters

Abstract: We present test beam studies and results on the timing performance and characterization of the time resolution of Lutetium–Yttrium Orthosilicate (LYSO)-based calorimeters. We demonstrate that a time resolution of 30 ps is achievable for a particular design. Furthermore, we discuss precision timing calorimetry as a tool for the mitigation of physics object performance degradation effects due to the large number of simultaneous interactions in the high luminosity environment foreseen at the Large Hadron Collider.

A high-resolution thermoelectric module-based calorimeter for measuring the energetics of isolated ventricular trabeculae at body temperature

Abstract: Isolated ventricular trabeculae are the most common experimental preparations used in the study of cardiac energetics. However, the experiments have been conducted at subphysiological temperatures. We have overcome this limitation by designing and constructing a novel calorimeter with sufficiently high thermal resolution for simultaneously measuring the heat output and force production of isolated, contracting, ventricular trabeculae at body temperature. This development was largely motivated by the need to better understand cardiac energetics by performing such measurements at body temperature to relate tissue performance to whole heart behavior in vivo. Our approach uses solid-state thermoelectric modules, tailored for both temperature sensing and temperature control. The thermoelectric modules have high sensitivity and low noise, which, when coupled with a multilevel temperature control system, enable an exceptionally high temperature resolution with a noise-equivalent power an order of magnitude greater than those of other existing muscle calorimeters. Our system allows us to rapidly and easily change the experimental temperature without disturbing the state of the muscle. Our calorimeter is useful in many experiments that explore the energetics of normal physiology as well as pathophysiology of cardiac muscle.

Thermal properties measurement of binary carbonate salt mixtures for concentrating solar power plants

Abstract: Specific heat capacity of an alkali molten salt mixture which is composed of lithium carbonate and potassium carbonate was measured using a differential scanning calorimeter (DSC). The specific heat capacity measurement was performed for 14 different composition ratios of the molten salt mixture to examine the effect of composition ratios on the specific heat capacity. The measured specific heat capacity values were compared with theoretically predicted values by the thermal equilibrium model. Additionally, changes in both melting point and latent heat of fusion were also investigated with change in the composition of two salts. In results, according to the heat flow curves in liquid phase obtained from DSC, the carbonate molten salt mixture could be categorized to three distinct groups: (1) gradually increased specific heat capacity, (2) dramatic decrease in the specific heat capacity, and (3) uniform specific heat capacity. Moreover, the specific heat capacity of the carbonate salt mixtures was strongly dependent upon the mole fraction of lithium carbonate. The specific heat capacity of the salt mixtures was drastically increased up to that of pure lithium carbonate in liquid phase, and decreased down to that of pure potassium carbonate in solid phase. In comparison with theoretical prediction, while the predictions were linearly increased with mole fraction of lithium carbonate, however, the measured data showed no linearity in the change of the specific heat capacity. The effect of the composition was also shown in the melting temperature and latent heat of fusion.

Measurement of isobaric heat capacity of pure water up to supercritical conditions

Abstract: A flow calorimeter was developed to measure the isobaric heat capacities of pure water at high pressure and high temperature up to supercritical region. Experimental isobaric heat capacities of pure water from 395 K to 665 K and pressure up to 26 MPa are presented. The total measurement uncertainties of temperature and pressure were ±0.02 K and ±3.88 kPa, respectively. The relative uncertainty of the isobaric heat capacity was estimated to be ±0.98%. The aim of this study is to provide new experimental data to complete the non-experimental data region and to check the accuracy of the IAPWS-95 formulation. The IAPWS-95 formulation shows great accuracy at temperatures under 623 K and at pressures under 22 MPa region. However, in the near-critical and supercritical region, its accuracy needs more experimental data for verification and to extend theories.

Measurements of the isobaric heat capacity of pressurized liquid trans-1,3,3,3-tetrafluoropropene [R1234ze(E)] by scanning calorimetry

Abstract: Isobaric heat capacity of pressurized liquid trans-1,3,3,3-tetrafluoropropene [R1234ze(E)] was measured by scanning calorimetry. The experimental system basically consists of a Calvet calorimeter (Setaram C80) and a pressure balance unit. A total of 95 data points were obtained at temperatures from 310.15 to 365.15 K and pressures up to 5.5 MPa. An empirical equation was used to correlate the experimental data with an average absolute percentage deviation of 0.18 %. Besides, a comparison was carried out between present data and literature data and three latest fundamental equations of state. Finally, saturated liquid heat capacity of R1234ze(E) was also investigated in this paper.

Measuring the mechanical efficiency of a working cardiac muscle sample at body temperature using a flow-through calorimeter

Abstract: We have developed a new ‘work-loop calorimeter’ that is capable of measuring, simultaneously, the work-done and heat production of isolated cardiac muscle samples at body temperature. Through the innovative use of thermoelectric modules as temperature sensors, the development of a low-noise fluid-flow system, and implementation of precise temperature control, the heat resolution of this device is 10 nW, an improvement by a factor of ten over previous designs. These advances have allowed us to conduct the first flow-through measurements of work output and heat dissipation from cardiac tissue at body temperature. The mechanical efficiency is found to vary with peak stress, and reaches a peak value of approximately 15 %, a figure similar to that observed in cardiac muscle at lower temperatures.

Performance of fully instrumented detector planes of the forward calorimeter of a Linear Collider detector

Abstract: Detector-plane prototypes of the very forward calorimetry of a future detector at an e+e− collider have been built and their performance was measured in an electron beam. The detector plane comprises silicon or GaAs pad sensors, dedicated front-end and ADC ASICs, and an FPGA for data concentration. Measurements of the signal-to-noise ratio and the response as a function of the position of the sensor are presented. A deconvolution method is successfully applied, and a comparison of the measured shower shape as a function of the absorber depth with a Monte-Carlo simulation is given.

Room-temperature calorimeter for x-ray free-electron lasers

Abstract: We have developed a room-temperature calorimeter for absolute radiant power measurements of x-ray free-electron lasers. This room-temperature calorimeter is an electrical substitution device based on the equivalence of electrical and radiant heating. Consequently, the measured radiant powers are traceable to electrical standards, i.e., the International System Units (SI). We demonstrated the performance of the room-temperature calorimeter by electrical power measurements (offline tests). In the offline tests, the room-temperature calorimeter was proven to be able to measure external powers up to at least 6.9 mW, which exceeds the upper limit (∼4 mW) of a cryogenic radiometer (the primary standard detector in Japan). In addition, measurement uncertainties of the room-temperature calorimeter were evaluated to be less than 1.0%, which is adequate for the radiant power measurements of x-ray free-electron lasers. An indirect comparison with the cryogenic radiometer was performed using a synchrotron radiation source to confirm the validity of the absolute radiant powers measured with the room-temperature calorimeter. The absolute radiant powers measured by the calorimeter agreed with those measured by the cryogenic radiometer within 0.6%, which is less than the relative standard uncertainty of the comparison (1.0%).

Pion and proton showers in the CALICE scintillator-steel analogue hadron calorimeter

Abstract: Showers produced by positive hadrons in the highly granular CALICE scintillator-steel analogue hadronic calorimeter were studied. The experimental data were collected at CERN and FNAL for single particles with initial momenta from 10 to 80 GeV/c. The calorimeter response and resolution and spatial characteristics of shower development for proton- and pion-induced showers for test beam data and simulations using Geant4 version 9.6 are compared.