Abstract:
Disclosed is a method for analyzing internal density of material by using X-ray computed tomography, comprising the steps of installing a cylinder-shaped jig between an x-ray generator and an x-ray detector, inserting a material to be analyzed and a plurality of standard specimens whose densities are known into the inside of the cylinder-shaped jig, performing X-ray computed tomography while rotating the cylinder-shaped jig through 360°, and calculating the internal density of distribution of the material to be analyzed by using the X-ray intensities shown in the x-ray tomography image. By using the method of the present invention, X-ray tomography image is converted to the image showing the internal density distribution of the material, improving the qualitative decision by naked eye by providing quantitative decision method.
Abstract:
PROBLEM TO BE SOLVED: To provide a new insensitive solid propellant composition which is insensitive to impact and thermal reaction and used for a solid rocket propulsion engine.SOLUTION: The insensitive solid propellant composition includes: 5-10 wt.% of one or more selected from hydroxyl group-terminated polyethers and hydroxyl group-terminated polycaprolactone ethers as a binder; 5-15 wt.% of N-butyl-N-(2-nitrateethyl)nitramine as a plasticizer; 10-70 wt.% of ammonium perchlorate as a main oxidant: 10-30 wt.% of ammonium nitrate as an auxiliary oxidant; and 1-30 wt.% of one or more selected from the group comprising Al-compounds, Zr-compounds, B-compounds and Fe-compounds.
Abstract:
PROBLEM TO BE SOLVED: To provide a cooling device for fluid, capable of minimizing influences by external environments.SOLUTION: The cooling device includes: a heat exchanger configured such that fluid is introduced therein to be heat-exchanged with a refrigerant, and configured to vaporize the refrigerant by the heat exchange such that the fluid is discharged at temperature close to vaporization temperature of the refrigerant; a compressor connected to the heat exchanger and configured to compress the fluid discharged out of the heat exchanger; a turbine connected to the compressor and configured to expand the fluid compressed in the compressor to lower temperature of the compressed fluid; and a phase change heat exchanger connected to the turbine, storing a phase change material, and configured to cause heat exchange between the phase change material and the fluid discharged out of the turbine so as to control temperature of the discharged fluid.
Abstract:
PROBLEM TO BE SOLVED: To provide a method for producing pitch for impregnating a carbon-carbon composite material having low viscosity and an improved carbonation yield. SOLUTION: The method for producing pitch for impregnating a carbon-carbon composite material comprises the following steps: (i) a step for crushing coal-based pitch, (ii) a step for crushing and dissolving the crushed coal-based pitch with an alcoholic solvent and a cross-linking agent, (iii) a step for drying the crushed and dissolved mixture to remove the alcoholic solvent and (iv) a step for cooling and subsequently pulverizing the mixture from which the alcoholic solvent has been removed. COPYRIGHT: (C)2011,JPO&INPIT