• Proceedings of the Korean Geotechical Society Conference
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• 2002.03a
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• pp.253-260
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• 2002

Chemical weathering processes related with mineralogical characters and ground water condition are very essential engineering problems in soluble rock masses. Detailed geological mapping were performed and 8 samples were collected from the 2 formations including various rock faces to deduce the possibility of the limestone cavity formation and their mechanism. Petrological descriptions and various petro-mineralogical experiments such as XRD analysis, clay mineral analysis, absorptivity test, impurity analysis were conducted to evaluate the cavity making processes. Laboratory solubility test for rock specimen were also carried out under the strong acid (pH=1) condition. From the experimental data and geological mapping data, it is found that the formation of limestone cavities in limestones are strongly related with geological structures such as beddings, cleavages and the contents of impurities rather than CaCO$_3$contents. In case of dolomites, rock textures, grain size, amounts and types of clay minerals as well as geological structures are major controlling factors of cavity forming processes

• Journal of the Korean Ceramic Society
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• v.20 no.1
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• pp.13-18
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• 1983

The investigations have been carried out to study the characteristics of limestone using in Korean cement industry with prime interests in the dissociation and thermal phase changes of limestone between 90$0^{\circ}C$ and 140$0^{\circ}C$ The range of decomposition temperature of limestone was 840-87$0^{\circ}C$ and it was considered that the temperature was lowered by impurities in the limestone. The more the impurities and the finer the grain size of quartz in limestone the lower temperature was applied in forming $C_2S$ mineral the temperature of about 100$0^{\circ}C$. The major clinker minerals such as $C_3S$, $C_2S$, $C_3A$ and $C_4AF$ were formed in most of limestone when the firing temperature was up to 130$0^{\circ}C$.

• Journal of Animal Environmental Science
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• v.7 no.2
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• pp.83-102
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• 2001

Phytic acid (myo-inositol hexaphosphate or IP6) is the major storage form of phosphorus in cereals and legumes, representing 18 to 88% of the total phosphorus. Phytate form of phosphorus is not readily utilized by monogastric animals and this result causes pollution problem by phosporus released in areas of intensive livestock production. The interaction between phytic acid and essential dietary minerals, protein, or vitamins is considered to be one of the primary factors limiting the nutritional values of cereals and legunes in monogastric animals. Attempts have been made to hydrolyze dietary phytic acid by phytases to improve the feed quality and to decrease the amount of phosphorus excreted by animals. Phytase(myo-inositol hexakisphosphate phosphohydrolase) hydrolyzes phytic acid to myo-inositol and phosphoric acid. Two types of phytases are known: 3-phytase (EC 3.1.3.8) and 6-phytase (EC 3.1.3.26), indicating the intial attack to the susceptable phosphoester bond. Because of its great industrial importance, there is ongoing interest in isolating new bacterial strains producing novel and efficient phytases.

• Food Science and Industry
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• v.49 no.2
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• pp.18-24
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• 2016

Sodium chloride (NaCl) is a very important as one of major food ingredients in food industries. Recently, as the potential risk of adult diseases such as hypertension by overingestion of sodium, health authorities of many countries are executing policies for the reduction of sodium to suppress the overingestion of sodium by intake of NaCl. As general ways, the replacement of NaCl with either alternative salts, such as solar salts and minerals, for examples calcium, magnesium, potassium, lactic acid, and so on, and the addition of flavor enhancers were used to reduce the contents of sodium in foods. Recently, controls of particle size of sodium chloride or release point are emerging as new salt-manufacturing technologies for the sodium reduction. Upon reducing NaCl in foods it is important to develop practically adaptable technologies on the basis of the consideration of the unique functions of NaCl in foods, in particular effects on rheological characters, function as a humectant, shorten shelf life time, and so on.

• Journal of Marine Bioscience and Biotechnology
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• v.15 no.2
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• pp.90-95
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• 2023

This study aimed to develop low-salt seasoned Gim (김) with new functionality to meet the diversification of the export market and consumer demand for Gim, which is one of the four major seafood products in Chungcheongnam-do province. Spirulina, a microalgae containing essential amino acids, vitamins, and minerals, is known to have antioxidant components such as phycocyanin. Therefore, to determine the suitability of spirulina as a seasoning material, we conducted seaweed. It can be used as a substitute for seasoning salt in the development of low-salt seasoned laver with enhanced functionality.

• Economic and Environmental Geology
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• v.28 no.6
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• pp.571-577
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• 1995

Several acid-sulfate clay deposits associated with silicic magmas occur in the Haenam area of the southwestern part of Korea. Geology of the studied area consists of tuffs, granitic rocks, quartz porphyry, rhyolite, andesite and sedimentary rocks. The granitic rocks and quartz porphyry intruded tuffs and sedimentary rocks. The rhyolite and tuffs around the mines have undergone hydrothermally weak or strong alteration. Gold contents with major and trace elements have been determined for a total of sixty-seven specimens of fresh igneous rocks, wall rocks and minerals such as dickite and alunite by graphite furnace atomic absorption spectrometer and inductively coupled plasma. Gold is enriched in the alunite vein and the silicified zone, but is depleted in dickites and hydrothermally altered rocks with dickite of the Seongsan deposit. Gold is especially concentrated near the faults or conjunction area of two faults. High content of gold is shown in the mineral assemblages of alunitequartz- pyrite in the alunite vein and silicic zone of the Seongsan deposit compared with that of minerals and rocks from another deposits distributed in the studied area. Gold content in tuffs and dickites with pyrite is generally low. Gold content in silicified tuff tends to show positive correlations with content of As, Hg and Sb. Variation trends of Cd, Hg and Sb are similar to those of gold content. From the result of gold content variations, gold may be transported and concentrated by mineralizing solutions ascending along the cracks like fault. Therefore, it is important to survey alunite vein and silicified zone at the conjunction of faults, and to analyze pathfinder elements such as As, Hg and Sb for geological and geochemical exploration of gold in the studied deposits.

• Economic and Environmental Geology
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• v.47 no.5
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• pp.507-515
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• 2014

Asbestos is designated as carcinogen minerals. Detoxification of asbestos is being conducted by physical and chemical treatments that lead the formation of non-fibrous mineral particles or phase transitions. Major researches have been performed on mineralogical properties of asbestos and possibilities of detoxification in Korea. More specific studies are needed to prove the form and crystal structure changes during the detoxification of asbestos via heat treatment. Therefore, we studied thermal effects on mineralogical characteristics of chrysotile and asbestiform tremolite using electron microscopy investigation. Electron microscopy investigation showed chrysotile fibers were fully transformed into rod-shaped forsterite at $850^{\circ}C$ in 2 hours, and asbestiform tremolite fibers were converted into non-fibrous diopside at $1050^{\circ}C$ in 2 hours. Fibrous asbestos were converted into rod-shaped minerals, which are non-asbestiform. However, compositions of both minerals were not changed before and after heat treatment. These results indicate that thermal treatment of asbestos completely broke down asbestos structure due to dehydroxylation and recrystallization. Thus, electron microscopy investigation can provide the useful information of shapes, crystal structure, and chemistries of the asbestos for the detoxification.

• Journal of the Korean Society of Food Science and Nutrition
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• v.25 no.4
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• pp.649-653
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• 1996

This study was carried out to quantitate the proximate composition of free sugars, amino acids, fatty acids, and minerals contents in Jehotang. The analysis of overall chemical components of Jehotang indicates that it contains 22.40% of moisture, 1.31% of crude protein, 1.24% of crude fat, 0.80% of ash and 74.25% of carbohyderate. The pH of the Jehotang was 3.2. The sugar content was relatively high. Among the identified extractable free sugars were 15.3% of fructose, 13.6% of glucose, 0.42% of sucrose, 1.18% of maltose, and a trace of isomaltose. No raffinose, maltotriose and molezitose were detected. In amino acid composition of the Jehotang, leucine was the highest with the content of 9.6mg, followed by arginine, valine, and phenylalanine. The ratio of essential/total amino acid was 40.4%. Fatty acid content, which occupies 1.24%, can be classified into 4 kinds. Major ones, in order of quantity, are oleic acid(52.7%), linoleic acid(28.5%), palmitic acid(14.6%) and stearic acid(4.2%). Among the minerals, the amount of K was the highest with the level of 2430.5ppm, followed by Ca, Na, P, Mg, Fe, Mn, Zn and Cu.

• The Journal of Engineering Geology
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• v.14 no.3 s.40
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• pp.259-272
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• 2004

The purpose of this study is to investigate the effect of hydrochemical variation of groundwater on the gas tigtness in an unlined oil storage cavern. The groundwater chemistry is greatly influenced by the seawater mixing, the water curtain and the dissolution of grounting cements. The chemical composition of groundwater greatly varies ac-cording to both the location of monitoring wells and the sampling period. Most of groundwater shows alkaline pH and high electrical conductivity. The chemical types of groundwater show the dominant order as follows : Na-Cl type > Ca-Cl type > $Ca-HCO_3(CO_3)$ type. Thermodynamic equilibrium state between chemical composition of groundwater and major minerals indicates that carbonate minerals except clay minerals can be precipitated as a secondary mineral. It means that the secondary precipitates can not greatly exerts the clogging effect into fracture aperture in rock mass around oil storage cavern. The content of total organic carbon (TOC) shows a slightly increasing trend from initial stage to late stage. The $EpCO_2$ was computed so as to assess the gas contribution on the $CO_2$ in groundwater. The $EpCO_2$ of 0$\~$41.3 indicates that the contribution of oil gas on $CO_2$ pressure in groundwater system can be neglected.

• The Journal of Engineering Geology
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• v.8 no.2
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• pp.175-188
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• 1998

This paper describes the internal structures and K-Ar ages of fault gouges collected from the Dongnae fault zone. This fault zone is internally zoned and occurs in the multiple fault cores. A fault core consists of thin gouge and narrow cataclastic zones that are bounded by a much thicker damage zone. Intensity of deformation and alteration increases from damage zone through cataclastic zone to gouge zone. It is thought that cataclasis of brittle deformation was the dominant strain-accomodation mechanism in the early stage of deformation to form the gouge zone and that crushed materials in the regions of maximum localization of fault slip subsequently moved by cataclastic flow. Deformation mechanism drastically changed from brittle processes to fluid-assisted flow along the gouge zone as the high porosity and permeability of pulverzied materials during faulting facilitated the influx of the hydrothermal fluids. Subsequently, the fluids reacted with gouge materials to form clay minerals. Fracturing and alteration could have repeatedly taken place in the gouge zone by elevated fluid pressures generated from the reduction of pore volume due to the formation of clay minerals and precipitation of other materials. XRD analysis revealed that the most common clay minerals of the gouge zones are illite and smectite with minor zeolite and kaolinite. Most of illites are composed of 1Md polytype, indicating the products of hydrothermal alteration. The major activities of the Dongnae fault can be divided into two periods based upon K-Ar age data of the fault gouges : 51.4∼57.5Ma and 40.3∼43.6Ma. Judging from the enviromental condition of clay mineral formation, it is inferred that the hydrothermal alteration of older period occured at higher temperature than that of younger period.