1,659 research outputs found
Experimental Tests of Particle Flow Calorimetry
Precision physics at future colliders requires highly granular calorimeters
to support the Particle Flow Approach for event reconstruction. This article
presents a review of about 10 - 15 years of R\&D, mainly conducted within the
CALICE collaboration, for this novel type of detector. The performance of large
scale prototypes in beam tests validate the technical concept of particle flow
calorimeters. The comparison of test beam data with simulation, of e.g.\
hadronic showers, supports full detector studies and gives deeper insight into
the structure of hadronic cascades than was possible previously.Comment: 55 pages, 83 figures, to appear in Reviews of Modern physic
On the Stabilizing Action of Protein Denaturants: Acetonitrile Effect on Stability of Lysozyme in Aqueous Solutions
Stability of hen lysozyme in the presence of acetonitrile (MeCN) at different pH values of the medium was studied by scanning microcalorimetry with a special emphasis on determination of reliable values of the denaturational heat capacity change. It was found that the temperature of denaturation decreases on addition of MeCN. However, the free energy extrapolation showed that below room temperature the thermodynamic stability increases at low concentrations of MeCN in spite of the general destabilizing effect at higher concentrations and temperatures. Charge-induced contribution to this stabilization was shown to be negligible (no pH-dependence was found); therefore, the most probable cause for the phenomenon is an increase of hydrophobic interactions at low temperatures in aqueous solutions containing small amounts of the organic additive. The difference in preferential solvation of native and denatured states of lysozyme was calculated from the stabilization free energy data. It was found that the change in preferential solvation strongly depends on the temperature in the water-rich region. At the higher MeCN content this dependence decreases until, at 0.06 mole fractions of MeCN, the difference in the preferential solvation between native and denatured lysozyme becomes independent of the temperature over a range of 60 K. The importance of taking into account non-ideality of a mixed solution, when analyzing preferential solvation phenomena was emphasized
Development of techniques and associated instrumentation for high temperature emissivity measurements Quarterly progress report, 30 Sep. - 31 Dec. 1970
Emittance measurement techniques for space shuttle materials in high temperature environmental simulatio
Battery Efficiency Measurement for Electrical Vehicle and Smart Grid Applications Using Isothermal Calorimeter: Method, Design, Theory and Results
The chapter primarily explores the likelihood of heat measurement by means of the calorimeter in the lithium-ion battery cells for different applications. The presented focus applications are electrical vehicle and smart grid application. The efficiency parameter for battery cell is established using state of the art isothermal calorimeter by taking the consideration of heat related measurement. The calorimeter is principally used for the determination of the heat flux of the battery cell. The main target is to achieve the precision and accuracy of measurement of battery cell thermal performance. In this chapter, the assessment of battery efficiency parameter is proposed. A newly devised efficiency calculation methodology is projected and illustrated. The procedure ensures the precision an accurate measurement of heat flux measurement and turns into more comparable efficiency parameter. In addition, the issue is to investigate thermal sensitivity to factors that influence the energy storage system performance, i.e., current rate and temperature requirements. The results provide insight into the establishment of new key performance indicator (KPI) efficiency specification of the battery system. The usage of the calorimetric experiments is presented to predict the temperature distribution over a battery cell and an array of cells
Study of thermal interfaces aging for power electronics applications
International audienceThis paper presents new investigations on the aging of Thermal Interface Materials (TIM) subjected to thermal cycling conditions. The challenge was to design a specific and original set-up in order to not only undergo avionic temperature mission profile (-50°C/150°C) but also to perform standardized thermal characterization at always same conditions. Thermal conductivity is used as aging indicator. Several TIM materials (change phase, graphite and polymer based) have undergone more than 850 of such cycles. As a result, only the phase change material thermal interface has been affected with a 30% decrease of initial thermal resistance
Critical Review of Theoretical Models for Anomalous Effects (Cold Fusion) in Deuterated Metals
We briefly summarize the reported anomalous effects in deuterated metals at
ambient temperature, commonly known as "Cold Fusion" (CF), with an emphasis on
important experiments as well as the theoretical basis for the opposition to
interpreting them as cold fusion. Then we critically examine more than 25
theoretical models for CF, including unusual nuclear and exotic chemical
hypotheses. We conclude that they do not explain the data.Comment: 51 pages, 4 Figure
Aspects of laminar free convection from a vertical plate
The thesis is comprised of a number of aspects pertaining to the phenomenon of laminar free convection from a vertical plate. A survey of literature is presented which brings out the fact, that the phenomenon although it has been investigated to a large extent, still gives rise to widespread dispute and uncertainties which need careful examination. An analytical approach is presented showing that the hydrodynamic boundary layer is equal to the thermal boundary layer. In the past it was simply assumed to be so, in order to limit the computations, and the assumption was justified by the excellent agreement between calculations and experimental data. An analysis is presented showing the analogy existing between the Grashof and Reynolds numbers, as it is expected in the case of low velocities and considerable temperature differences, i.e. in free convection. An extensive experimental investigation pertaining to average heat transfer rates from a vertical plate at low Grashof numbers is presented and provides the necessary evidence in a much disputed region. It is shown conclusively that as far as average heat transfer rates are concerned, the agreement with the already accepted relationship can be extended to Grashof numbers as low as 10
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