The Experts below are selected from a list of 9 Experts worldwide ranked by ideXlab platform
Hyunchae Cynn - One of the best experts on this subject based on the ideXlab platform.
-
equation of state phase transition decomposition of β hmx octahydro 1 3 5 7 tetranitro 1 3 5 7 tetrazocine at high pressures
Journal of Chemical Physics, 1999Co-Authors: Hyunchae CynnAbstract:Pressure-volume relations and vibrational Raman spectra of unreacted HMX (octahydro-1, 3,5,7-tetranitro-1,3,5,7-tetrazocine) have been obtained in both quasiHydrostatic conditions to 45 GPa and nonHydrostatic conditions to 10 GPa by using diamond-anvil cell, angle-resolved synchrotron x-ray diffraction, and micro-Raman spectroscopy. The results show that the high-pressure behavior of HMX strongly depends on the stress conditions. HMX is more compressible in Hydrostatic conditions (B0=12.4 GPa and B′=10.4) than in nonHydrostatic conditions (B0=14.4 GPa, B′=13.3). This discrepancy in HMX compressibility can be explained in terms of chemical reactions occurring in nonHydrostatic conditions. The static isotherm is in good agreement with the shock Hugoniot, suggesting little temperature effect on the pressure–volume relation. The Hydrostatic Data suggest that β(monoclinic)-HMX undergoes two phase transitions: (i) a conformational transition at 12 GPa with no apparent abrupt volume change and (ii) a discontinuo...
B K Godwal - One of the best experts on this subject based on the ideXlab platform.
-
deriving equations of state from non Hydrostatic Data
Journal of Physics: Conference Series, 2012Co-Authors: Raymond Jeanloz, B K GodwalAbstract:Modeling of non-Hydrostatic strains allows extraction of a reliable (quasi-Hydrostatic) equation of state from diamond-cell x-ray measurements at high pressures, as illustrated by new Data on Os collected to 60 GPa at room temperature: axial- and radial-diffraction measurements are in good agreement with Data collected using Ar and He pressure media, as well as with first-principles calculations, in confirming that osmium is the densest but not the most incompressible element. Dynamic-loading methods can generate much higher pressures than static compression, however, shock compression leads to high temperatures there is much interest in compression using ramp waves. This can be accomplished with graded-density mechanical impacts, or with laser-driven pressure waves; other means of maintaining low temperatures include pre-compression and cooling of the sample before it is dynamically compressed by ramp- or multiple-shock waves. Reduced temperatures lead to enhanced strength, which makes it necessary to model both temperature and strength effects in order to extract the equation of state. A unified approach combining analysis of static and dynamic compression measurements offers a means of determining pressure?density equations of state to high compressions.
Raymond Jeanloz - One of the best experts on this subject based on the ideXlab platform.
-
deriving equations of state from non Hydrostatic Data
Journal of Physics: Conference Series, 2012Co-Authors: Raymond Jeanloz, B K GodwalAbstract:Modeling of non-Hydrostatic strains allows extraction of a reliable (quasi-Hydrostatic) equation of state from diamond-cell x-ray measurements at high pressures, as illustrated by new Data on Os collected to 60 GPa at room temperature: axial- and radial-diffraction measurements are in good agreement with Data collected using Ar and He pressure media, as well as with first-principles calculations, in confirming that osmium is the densest but not the most incompressible element. Dynamic-loading methods can generate much higher pressures than static compression, however, shock compression leads to high temperatures there is much interest in compression using ramp waves. This can be accomplished with graded-density mechanical impacts, or with laser-driven pressure waves; other means of maintaining low temperatures include pre-compression and cooling of the sample before it is dynamically compressed by ramp- or multiple-shock waves. Reduced temperatures lead to enhanced strength, which makes it necessary to model both temperature and strength effects in order to extract the equation of state. A unified approach combining analysis of static and dynamic compression measurements offers a means of determining pressure?density equations of state to high compressions.
Gulgi Choi - One of the best experts on this subject based on the ideXlab platform.
-
determination of global ice loads on the ship using the measured full scale motion Data
International Journal of Naval Architecture and Ocean Engineering, 2016Co-Authors: Gulgi ChoiAbstract:Abstract This paper describes the whole procedures to determine ice-induced global loads on the ship using measured full-scale Data in accordance with the method proposed by the Canadian Hydraulics Centre of the National Research Council of Canada. Ship motions of 6 degrees of freedom (dof) are found by processing the commercial sensor signals named Motion Pak II under the assumption of rigid body motion. Linear accelerations as well as angular rates were measured by Motion Pak II Data. To eliminate the noise of the measured Data and the staircase signals due to the resolution of the sensor, a band pass filter that passes frequencies between 0.001 and 0.6 Hz and cubic spline interpolation resampling had been applied. 6 dof motions were computed by the integrating and/or differentiating the filtered signals. Added mass and damping force of the ship had been computed by the 3-dimensional panel method under the assumption of zero frequency. Once the coefficients of hydrodynamic and Hydrostatic Data as well as all the 6 dof motion Data had been obtained, global ice loads can be computed by solving the fully coupled 6 dof equations of motion. Full-scale Data were acquired while the ARAON rammed old ice floes in the high Arctic. Estimated ice impact forces for two representative events showed 7–15 MN when ship operated in heavy ice conditions.
