The Experts below are selected from a list of 183 Experts worldwide ranked by ideXlab platform

Konstantinos Chrissafis - One of the best experts on this subject based on the ideXlab platform.

  • Kinetics of thermal degradation of polymers
    Journal of Thermal Analysis and Calorimetry, 2008
    Co-Authors: Konstantinos Chrissafis
    Abstract:

    The thermal degradation of polymers has been studied quite extensively using thermogravimetric measurements. For the kinetic description, most of the times single rate Heating Data and model-fitting methods have been used. Since the thermal degradation of the polymers is a very complex reaction, the choice of a reliable model or a combination of kinetic models is very important. The advantages or the disadvantages of using a single Heating rate or multiple Heating rates Data for the determination of the kinetic triplet have been investigated. Also, the activation energy has been calculated with the isoconversional and model-fitting methods. The reaction model was determined with the model-fitting method. The limits of all these procedures were investigated with experimental Data of the thermal degradation of the poly(ethylene adipate) (PEAd).

Brian R. Hollis - One of the best experts on this subject based on the ideXlab platform.

  • Distributed Roughness Effects on Blunt-Body Transition and Turbulent Heating
    52nd Aerospace Sciences Meeting, 2014
    Co-Authors: Brian R. Hollis
    Abstract:

    An experimental program has been conducted to obtain Data on the effects of surface roughness on blunt bodies at laminar, transitional, and turbulent conditions. Wind tunnel models with distributed surface roughness heights from 0.06 mm to 1.75 mm were tested and Heating Data were obtained using global surface thermography. Heating rates of up to 85% higher than predicted, smooth-surface turbulent levels were measured.

  • Experimental Investigation of Project Orion Crew Exploration Vehicle AeroHeating: Larc 20-Inch Mach 6 Air Tunnel Test 6931
    2013
    Co-Authors: Brian R. Hollis
    Abstract:

    An investigation of the aeroHeating environment of the Project Orion Crew Entry Vehicle has been performed in the Langley Research Center 20-Inch Mach 6 Air Tunnel. Data were measured on a approx.3.5% scale model (0.1778-m/7-inch diameter) of the vehicle using coaxial thermocouples at free stream Reynolds numbers of 2.0 10(exp 6)/ft to 7.30 10(exp 6)/ft and computational predictions were generated for all test conditions. The primary goals of this test were to obtain convective Heating Data for use in assessing the accuracy of the computational technique and to validate test methodology and Heating Data from a test of the same wind tunnel model in the Arnold Engineering Development Center Tunnel 9. Secondary goals were to determine the extent of transitional/turbulent Data which could be produced on a CEV model in this facility, either with or without boundary-layer trips, and to demonstrate continuous pitch-sweep operation in this tunnel for heat transfer testing.

  • Experimental Investigation of Project Orion Crew Exploration Vehicle AeroHeating in Aedc Tunnel 9
    2013
    Co-Authors: Brian R. Hollis, Thomas J. Horvath, Karen T. Berger, Randolph P. Lillard, Benjamin S. Kirk, Joseph J. Coblish, Joseph D. Norris
    Abstract:

    An investigation of the aeroHeating environment of the Project Orion Crew Entry Vehicle has been performed in the Arnold Engineering Development Center Tunnel 9. The goals of this test were to measure turbulent Heating augmentation levels on the heat shield and to obtain high-fidelity Heating Data for assessment of computational fluid dynamics methods. Laminar and turbulent predictions were generated for all wind tunnel test conditions and comparisons were performed with the Data for the purpose of helping to define uncertainty margins for the computational method. Data from both the wind tunnel test and the computational study are presented herein.

  • Heating Augmentation in Laminar Flow Due to Heat-Shield Cavities on the Project Orion CEV
    AIAA Atmospheric Flight Mechanics Conference and Exhibit, 2008
    Co-Authors: Brian R. Hollis
    Abstract:

    An experimental study has been conducted to assess the effects of compression pad cavities on the aeroHeating environment of the Project Orion CEV heat-shield at laminar conditions. Testing was conducted in Mach 6 and Mach 10 perfect-gas wind tunnels to obtain Heating measurements on and around the compression pads using global phosphor thermography. Consistent trends in Heating augmentation levels were observed in the Data and correlations of average and maximum Heating at the cavities were formulated in terms of the local boundary-layer parameters and cavity dimensions. Additional Heating Data from prior testing of Genesis and Mars Science Laboratory models were also examined to extend the parametric range of cavity Heating correlations.

R.j.m. Konings - One of the best experts on this subject based on the ideXlab platform.

  • Recent advances in the study of the UO2–PuO2 phase diagram at high temperatures
    Journal of Nuclear Materials, 2014
    Co-Authors: R. Böhler, M.j. Welland, D. Prieur, P. Cakir, T. Vitova, T. Pruessmann, I. Pidchenko, C. Hennig, C. Guéneau, R.j.m. Konings
    Abstract:

    Abstract Recently, novel container-less laser Heating experimental Data have been published on the melting behaviour of pure PuO2 and PuO2-rich compositions in the uranium dioxide–plutonium dioxide system. Such Data showed that previous Data obtained by more traditional furnace Heating techniques were affected by extensive interaction between the sample and its containment. It is therefore paramount to check whether Data so far used by nuclear engineers for the uranium-rich side of the pseudo-binary dioxide system can be confirmed or not. In the present work, new Data are presented both in the UO2-rich part of the phase diagram, most interesting for the uranium–plutonium dioxide based nuclear fuel safety, and in the PuO2 side. The new results confirm earlier furnace Heating Data in the uranium-dioxide rich part of the phase diagram, and more recent laser-Heating Data in the plutonium-dioxide side of the system. As a consequence, it is also confirmed that a minimum melting point must exist in the UO2–PuO2 system, at a composition between x(PuO2) = 0.4 and x(PuO2) = 0.7 and 2900 K ⩽ T ⩽ 3000 K. Taking into account that, especially at high temperature, oxygen chemistry has an effect on the reported phase boundary uncertainties, the current results should be projected in the ternary U–Pu–O system. This aspect has been extensively studied here by X-ray diffraction and X-ray absorption spectroscopy. The current results suggest that uncertainty bands related to oxygen behaviour in the equilibria between condensed phases and gas should not significantly affect the qualitative trend of the current solid–liquid phase boundaries.

  • Recent advances in the study of the UO2–PuO2 phase diagram at high temperatures
    Journal of Nuclear Materials, 2014
    Co-Authors: R. Böhler, M.j. Welland, D. Prieur, P. Cakir, T. Vitova, T. Pruessmann, I. Pidchenko, C. Hennig, C. Guéneau, R.j.m. Konings
    Abstract:

    Recently, novel container-less laser Heating experimental Data have been published on the melting behaviour of pure PuO2 and PuO2-rich compositions in the uranium dioxide-plutonium dioxide system. Such Data showed that previous Data obtained by more traditional furnace Heating techniques were affected by extensive interaction between the sample and its containment. It is therefore paramount to check whether Data so far used by nuclear engineers for the uranium-rich side of the pseudo-binary dioxide system can be confirmed or not. In the present work, new Data are presented both in the UO2-rich part of the phase diagram, most interesting for the uranium-plutonium oxide based nuclear fuel safety, and in the PuO2 side. The new results confirm earlier furnace Heating Data in the uranium-dioxide rich part of the phase diagram, and more recent laser-Heating Data in the plutonium-dioxide side of the system. As a consequence, it is also confirmed that a minimum melting point must exist in the UO2 – PuO2 system, at a composition between x(PuO2) = 0.4 and x(PuO2) = 0.7 and 2900 K ≤ T ≤ 3000 K.JRC.E.3-Materials researc

Rong Liu - One of the best experts on this subject based on the ideXlab platform.

  • Study on Video Transmission System of Central Heating Based on 3G Wireless Network
    Applied Mechanics and Materials, 2014
    Co-Authors: Tie Qiang Sun, Zhao Hui Nie, Rong Liu
    Abstract:

    This paper briefly introduces the composition of central Heating Data transmission system which bases on 3G wireless networks and the realization of communication. The dates of temperature, flow and pressure, etc, are collected in remote heat-exchange station and are transmitted to dispatch center through 3G wireless network. Due to this, the remote monitoring for the whole Heating system is implemented in the dispatch center, which solves the problems of being difficult to collect thermal parameters for the whole system and the unevenness of heat distribution. The result of operation indicates that the system is stable, and offers high regulation accuracy and is easily operated, which meets the requirements of long-term stable operation of remote monitoring.

  • Study on Data Transmission System of Central Heating Based on 3G Wireless Network
    Applied Mechanics and Materials, 2011
    Co-Authors: Tie Qiang Sun, Zhao Hui Nie, Rong Liu
    Abstract:

    This paper briefly introduces the composition of central Heating Data transmission system which bases on 3G wireless networks and the realization of communication. The dates of temperature, flow and pressure, etc, are collected in remote heat-exchange station and are transmitted to dispatch center through 3G wireless network. Due to this, the remote monitoring for the whole Heating system is implemented in the dispatch center, which solves the problems of being difficult to collect thermal parameters for the whole system and the unevenness of heat distribution. The result of operation indicates that the system is stable, and offers high regulation accuracy and is easily operated, which meets the requirements of long-term stable operation of remote monitoring.

Nagio Hirota - One of the best experts on this subject based on the ideXlab platform.

  • Shallow and Deep Latent Heating Modes over Tropical Oceans Observed with TRMM PR Spectral Latent Heating Data
    Journal of Climate, 2010
    Co-Authors: Yukari N. Takayabu, Shoichi Shige, Wei-kuo Tao, Nagio Hirota
    Abstract:

    Abstract Three-dimensional distributions of the apparent heat source (Q1) − radiative Heating (QR) estimated from Tropical Rainfall Measuring Mission (TRMM) Precipitation Radar (PR) utilizing the spectral latent Heating (SLH) algorithm are analyzed. Mass-weighted and vertically integrated Q1 − QR averaged over the tropical oceans is estimated as ∼72.6 J s−1 (∼2.51 mm day−1) and that over tropical land is ∼73.7 J s−1 (∼2.55 mm day−1) for 30°N–30°S. It is shown that nondrizzle precipitation over tropical and subtropical oceans consists of two dominant modes of rainfall systems: deep systems and congestus. A rough estimate of the shallow-Heating contribution against the total Heating is about 46.7% for the average tropical oceans, which is substantially larger than the 23.7% over tropical land. Although cumulus congestus Heating linearly correlates with SST, deep-mode Heating is dynamically bounded by large-scale subsidence. It is notable that a substantial amount of rain, as large as 2.38 mm day−1 on averag...