• Geomechanics and Engineering
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• v.36 no.1
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• pp.9-18
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• 2024

With the rapid development of highways and railways, series of traffic safety issues emerged because of mudstone disintegration. To research on the mechanism and further guarantee the stability and safety of transportation infrastructure built on or near mudstone formations, the mudstone disintegration test of mudstone was carried out based on mudstone and sandy mudstone. The element types, cementation characteristics and pore characteristics of the tested specimens were studied by means of Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD) and Image Pro Plus (IPP). The disintegration index of mudstone was approximately 1%, and even some specimens were difficult to be calculated, while the disintegration index of sandy mudstone is approximately 8.7%. According to the results, the two mudstones belong to grade II and III disintegration respectively, of which the sandy stone presents more extensive disintegration than mudstone. This phenomenon was distinguished that, the clay minerals of mudstone are approximately 25% more abundant than those of sandy mudstone, and the unit pore area is 20 ㎛² larger, which result in different microstructure and water absorption capacities. In the liquid phase, the ions in the mudstone specimens were exchanged and combined with water molecules in the environment during the whole disintegration process. This results in continuous spalling and fragmentation of clay minerals, the emergence of secondary fractures, and the deepening of primary fractures.

• Journal of environmental and Sanitary engineering
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• v.13 no.3
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• pp.141-147
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• 1998

Under high temperature and high pressure, cyanogen disinter gration distruction mechanism brought followings results through continuous plug flow reactor system. 1. The temperature was a important reacting factor in cyanogen disintegration. Over $612.8^{\cird}K$ high disintegration rate or 99.99% was shown even under $2000{\;}mg/{\ell}$ cyanogen density. 2. The conditions of cyanogen disintegration was gained through experimenting the supercrietical condition of water in basic. To gain 99.99% disintegration rate under $1000{\;}mg/{\ell}$ early cyanogen density, the pressure showed 52.8 seconds at $523^{\cird}K$ and 84.2 atm and gained $0.56{\;}mg/{\ell}$ operating density. 3. Here is the reaction velocity formula of cyanogen disintegration by hydrolysis: This formula indicates the high possibility of cyanogen disintegration within a short time. And it also implys the potential possibility on treating NBDICOD and the technology in developing the environment cleaning progress as small size automatic controlling equipment.

• Journal of the korean Society of Automotive Engineers
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• v.14 no.6
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• pp.81-90
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• 1992

This paper deals with an experimental study on the initial condition of liquid film surface waves disintegration and investigation on the behavior of liquid film surface waves formed by the high speed air flow on the solid plane surface. The authors conducted the qualitative and quantitative study to in vestigate the liquid film flow phenomena, the liquid film disintegration mechanism, and droplet formation process with breaking the liquid film surface wave. The newly devised transparent rectangular test section which has semi-two-dimensional flow at the center of the bottom was introduced to perform the experimental study, and it can generate the uniform thickness liquid film at the bottom. The strobo streak camera was used to obtain the instantaneously transformed photographs. The electronic measuring device was also used to measure the liquid film thickness variation in order to perform the easy and effective analysis of complex flow phenomena in the air-water cocurrent flow.

• Journal of the Korea Institute of Military Science and Technology
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• v.12 no.2
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• pp.206-212
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• 2009

The pressurized spray system with nitrogen gas was designed to fabricate the spherical AN(ammonium nitrate) particles. When AN melt was sprayed from a nozzle with equivalent diameter of 0.28mm into an ambient dry air, the ligament breakup mechanism of the molten AN was found to be responsible for the droplet formation(or disintegration) of AN melt. In the experimental range of spray temperature with $170{\sim}200^{\circ}C$ and atomization pressure with $0.1{\sim}0.4MPa$, the spherical AN particles with mean diameter of $130{\sim}250{\mu}m$ were obtained.

• International Journal of Highway Engineering
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• v.15 no.4
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• pp.53-63
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• 2013

PURPOSES: The purpose of this study was to investigate the disintegration mechanism of concrete due to the infiltration of the moisture to the milling overlay pavement and to come up with a method to minimize the disintegration as well as verifying the effectiveness of the edge sealing and Fogseal method. METHODS : This study investigated the distress mechanism due to the infiltrated moisture remaining in the milling overlay pavement through chloride freezing test and verified the effectiveness of the sealing of the milling edge and fog seal methods, which have been devised to minimize the moisture infiltration, through laboratory water permeability test. Additionally, long-term pavement performance was compared for the effectiveness of the proposed method through under loading test, and field water permeability test was carried out to verify the field applicability of the proposed method. RESULTS: The result of the research confirmed that chloride deteriorates the concrete surface through disintegration and lowers its strength and that the laboratory moisture infiltration test verified the effectiveness of the milling edge sealing and fog seal methods in the deterrence of moisture infiltration to the overlay pavement with excellent long-term performance of the pavement treated with the proposed method. Although the field water permeability test revealed some deterrence of moisture infiltration of the milling edge sealing and fog seal methods to a certain extent, the difference was a little. CONCLUSIONS: The milling edge sealing and fog seal methods are limited in their effectiveness for the cases of improvident compaction management or mixture with large void, and it is believed that installation of subsurface drainage is more effective in these cases.

• Transactions of the Korean Society of Mechanical Engineers
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• v.12 no.6
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• pp.1390-1398
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• 1988

The purpose of this study was experimentally to investigate the disintegration process and disintegration mechanism when co-axial air flows vertically for the longest smooth liquid jet. These were affected by liquid velocity, air velocity, air-to-liquid diameter ratio, nozzle shape, and air-liquid contacting position. That is, this process of disintegration of the liquid jet was similar to that occurred when liquid pressure was increased. At Reynolds number of 10, 000 and below, the changes in the breakup length represent different tendency according to liquid flow rate. The influence of air flow on the disintegration of liquid jet was different according to air-to-liquid diameter ratio, air orifice diameter, nozzle shape and contacting position of liquid and air. In particular, when the tip of liquid nozzle was inside the air orifice, the effect of air flow was the larger than outside the air orifice. The effect of liquid mass flow rate on the change rate of the breakup length was also different.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2002.04a
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• pp.18-23
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• 2002

Liquid phase mixing of impinging injector is a resultant byproduct from the momentum exchange between a pair of impinging jets and penetration of opponent jet. Principal aim of the present study is revealing the liquid phase mixing mechanism of split triplet impinging injection sprays, and thus extending our understanding on this particular injection element. Overall mixing extent is estimated from patternation tests by the use of purified tap water and kerosene to simulate the real propellant components, respectively, and with the liquid jet momentum ratio, a controlling mixing parameter, in the range of 0.5 to 6.0. Emphasis is placed on the effect of liquid sheet superposition and disintegration, and the results with detailed spray visualization revealed the fact that superposed liquid sheet disintegration is the main pathway of liquid phase mixing of split triplet impinging injector to yield enhanced mixing qualities.

• Journal of the Korean Society of Propulsion Engineers
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• v.20 no.2
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• pp.39-45
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• 2016

In a coaxial porous injector, a gas propellant is injected through the porous cylinder surface to the liquid jet which is encircled by a porous cylinder. In this study, to observe the differences in disintegration mechanisms between a shear coaxial injector and a coaxial porous injector, cold-flow tests and 2-D axisymmetric numerical analysis have been carried out. The shadowgraph images and Sauter mean diameters were compared in similar experimental conditions, and the effects of velocity distributions at the inner injector region on the disintegration of liquid jet were investigated through the numerical calculations. As a result, in high air mass flow rate condition, the disintegration performance of coaxial porous injector is better than shear coaxial injector, in spite of a lower velocity at the inner injector region.

• Journal of Powder Materials
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• v.15 no.5
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• pp.411-421
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• 2008

Principles and historical background of high pressure liquid jet (HPLJ) technology is presented in the paper. This technology can be applied, among others, for production of nano particles. This target can be achieved in various type of disintegration systems developed and designed on the base of this technology. The paper describes principles of two examples of such systems: HPLJ-reactor, called also a linear comminuting system, HPLJ- centrifugal comminuting system, which prototypes have been manufactured. A linear mill, being high energy liquid jet reactor, has been developed and tested for micronization of various types of materials. The results achieved so far, and presented in the paper, show its potential for further improvement toward nano-size particle production. Flexibility of adjustment of the reactors and the mechanism of the process allows for the creation of particles with unprecedented rheology. The reactor can be especially suitable to micronize, mix and densify materials with a wide range of mechanical properties for various industrial needs. Presented prototypes of comminution systems generate interesting potentials toward production of nano particles. Their performance, based on up today research, confirms expected high efficiency of materials disintegration, which opens a new challenge for industrial applications. The paper points out benefits and area of possible applications of presented technology.

• 보존과학연구
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• s.33
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• pp.57-67
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• 2012

The Uiseong Tapriri Five-Storied stone pagoda has occurred exfoliation, granular disintegration and discoloration by physical and chemical weathering factors with the major deterioration occurring due to efflorescence by salt. According to the results of SEM-EDS and X-ray diffraction analysis, salts consists of gypsum, taranakite. Artificial salt weathering tests were carried out using the same type of rocks as those in the stone pagoda. The test results showed that efflorescence occurred on the surface of the rock, and that exfoliation and granular disintegration occurred inside the rock due to salt crystallization.