• Geophysics and Geophysical Exploration
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• v.11 no.3
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• pp.177-183
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• 2008

The sub-salt imaging technique becomes more crucial to detect the hydro-carbonates in petroleum exploration as the target reservoirs get deeper. However, the weak reflections from the sub-salt structures prevent us from obtaining high fidelity sub-salt image. As an effort to overcome this difficulty, we applied the waveform inversion by implementing multi-grid technique to the sub-salt imaging. Through the comparison between the conventional waveform inversion using fixed grid and the multi-grid technique, we confirmed that the waveform inversion using multi-grid technique has advantages over the conventional fixed grid waveform inversion. We showed that the multi-grid technique can complement he velocity estimation result of the waveform inversion for imaging the sub-salt structures, of which velocity model cannot be obtained correctly by the conventional fixed grid waveform inversion.

• Journal of the Korean Institute of Gas
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• v.28 no.2
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• pp.7-16
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• 2024

This study presents investigation on the technical characteristics and field cases of the salt cavern storage method for large-scale hydrogen storage. The salt cavern storage method enables effective hydrogen storage compared to other methods due to the low porosity and permeability of the rock salt that constitutes the cavern, which is not likely to leak and requires a small amount of cushion gas for operation. In addition, there is no chemical reaction between rock salt and hydrogen, and multiple injection/withdrawl cycles can be performed making it effective for peak shaving and short-term storage. The salt cavern is formed in three stages: leaching, debrining, and filling, and leakage tests are conducted to ensure stable operation. Field applications are currently performing to meet industrial demand in the surrounding area of four sites in the UK and Texas, USA, and salt cavern operation is being prepared for energy storage in European countries such as Germany and France. The investigated results in this study can be utilized as a basic guideline for the design of future hydrogen storage projects.

• Journal of the East Asian Society of Dietary Life
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• v.9 no.2
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• pp.247-256
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• 1999

매년 1억 8천여만톤의 소금이 전 세계에서 생산되어 식용과 공업용으로 소비되고 있는데, 이 소금 자원은 암염, 천연함수, 해수의 세 가지로 분류할 수 있다. 자원별 생산비율은 암염 41%, 천연함수 29%, 바닷물 26%, 기타 약 4%로 되어있다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.8
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• pp.149-155
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• 2019

This study aims to provide basic data for investigating the phenotypic traits and growth characteristics of Korean native black goats. The Jangsu and Tongyoung strains were shown to have black hair, while the Dangjin strain was shown to have black or dark brown long hair. Only the Tongyeong strain was found to have no wattle and one goat each from the females and males of the Dangjin strain was found to have no horns. The lengths of the ears and tails were similar for the female and male goats, while the lengths of horns and beards were longer in the male goats. The birth weight was 2 kg on average, with that of male goats tending to be slightly heavier than that of the females. Weights at the weaning period were found to be slightly heavier for the males. Also, at 12 months, the weights of the male goats by strain were shown to be heavier than that of the females. The body length and depth by strain were found to be higher for the male goats, while no differences in the chest width and girth between the strains or gender were found. These findings are expected to be used as a basis for differentiating between native and crossbred Korean black goat strains and for improving Korean native black goats.

• Computational Structural Engineering
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• v.8 no.4
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• pp.107-115
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• 1995

The long term behavior of the Waste Isolation Pilot Plant(WIPP), a nuclear waste repository currently under construction near Carlsbad at New Mexico, depends upon the fracture and deformation behavior of bedded rock salt. Although many numerical analyses of the WIPP have been conducted, to our knowledge none have included the ability to simultaneously predict the effects of fracture and nonlinear deformation of the salt continuum. We are in the process of developing a finite element program to simulate the effects of nonlinear fracture mechanics and nonlinear continuum behavior of rock salt simultaneously.

• Journal of Food Hygiene and Safety
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• v.14 no.3
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• pp.277-281
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• 1999

Chemical composition of imported table salts from China (sun dried), Thailand (sun dried) and Australia (rock salt) were compared the mineral content and heavv metal contamination with Korean sun dried salt. Kimchies prepared by those salts were analyzed the quality by pH, acidity and sensory evaluation. Chemical compositions were as follows : moisturefrom 1.7% (Australia) to 8.7% (Korea), sodium chloride-from 86.7% (China, summer) to 97% (Australia), insoluble matter in water-from 0.02% (Australia) to 0.18 (China), and sulfate ionfrom 0.03% (Australia) to 1.65% (China, summer). Judging by Korean Standard(KS) of salt, salt from Australia and Thailand belong to 1st grade, Korean and Chinese (winter) to 2nd grade, and China (summer) were out of 3rd grade. Ca and Mg content of the salts tested were 0.022% (Australia) to 0.246 (China, winter), 0.036% (Australia) to 0.841% (China, summer) respectively and Pb was 1.23 ppm(China, summer)~0.61ppm(Korea) which is within the Korean regulation. The other heavy metals, Pb, Cd, As and Hg were not detected in all salts tested. The quality of Kimchi prepared by those salts were significantly no difference with Korean sun dried salt.

• Mineral and Industry
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• v.18 no.2
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• pp.66-67
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• 2005

• Geotechnical Engineering
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• v.11 no.3
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• pp.139-162
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• 1995

The possibility of the development of gas driven hydrofractures at the Waste Isolation Pilot Plant(WIPP) is investigated through analytical and numerical calculations and through laboratory experiments. First, an investigation of the chemical reactions involved shows that a large volume of gas could potentially be generated through the oxidation of iron in the waste. Simple ground water'flow calculations then show that unless regions of high permeability has been created, this gas volume will build up the pressure high enough to cause tensile damage in the horizontal planes of weakness or in the halite itself. The analytical calculations were performed using the concepts of linear elastic fracture mechanics and the numerical calculations were done using the finite element method. Also, laboratory tests were conducted to illustrate possible failure mechanisms. It is possible that after growing horizontal crack in the weaker anhydride layer, the crack could break out of this layer and propagate upward into the halite and toward the ground surface at an inclined argle of around 53$^{\circ}$ above horizontal. To prevent this latter phenomenon the anhydrite must have a fracture toughness less than 0.5590 times than that of the halite. Through the tests, three types of crack(radial vertical cracks, horizontal circular cracks and cone -shaped cracks) were observed.

• Geophysics and Geophysical Exploration
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• v.15 no.2
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• pp.66-74
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• 2012

This paper presents development of a three-dimensional marine controlled-source electromagnetic (mCSEM) modeling algorithm and its application to a salt and reservoir model to examine detectability of mCSEM for a reservoir under complex subsurface structures. The algorithm is based on the finite difference method, and employs the secondary field formulation for an accurate and fast calculation of modeling responses. The algorithm is verified for a two-layer model by comparing solutions not only with analytic solutions but also with those from other 3D modeling algorithm. We calculate and analyze electric and magnetic fields and their normalized responses for a salt and reservoir model due to three sources located at boundaries between a salt, a reservoir, and background. Numbers and positions of resistive anomalies are informed by normalized responses for three sources, and types of resistive anomalies can be informed when there is a priori information about a salt by seismic exploration.

• Proceedings of the Korean Magnestics Society Conference
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• 2012.11a
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• pp.122-123
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• 2012