• Journal of the Korean earth science society
• /
• v.21 no.4
• /
• pp.437-448
• /
• 2000

The Middle Carboniferous Gabsan Formation is distributed in the Cheongrim area of southern Yeongwol and the Mt. Gachang area of Chungbuk Province. This study was carried out to investigate the lithological characters and geochemical composition of the limestones and to find out controlling structures of the limestones of the formation. The limestones of the Gabsan Formation are characterized by the light gray to light brown in color and fine and dense textures. The limestone grains are composed of crinoid fragments, small foraminfers, fusulinids, gastropods, ostracods, etc. Due to the recrystallization, some limestones consist of fine crystalline calcites. The chemical analysis of limestones of the formation was conducted to find out the contents of CaO, MgO, Al$_2$O$_3$, Fe$_2$O$_3$ and SiO$_2$. The content of CaO ranges from 49.78-60.63% and the content of MgO ranges from 0.74 to 4.63% The contents of Al$_2$O$_3$ and Fe$_2$O$_3$ are 0.02-0.55% and 0.02${\sim}$0.84% , respectively. The content of SiO$_2$ varies from 1.55 to 4.80%, but some samples contain more than 6.0%. The limestones of the formation can be grouped into two according to the CaO content: One is a group of which CaO content ranges from 49.78 to 56.26% and the other is a group of which CaO content varies from 59.36 to 60.38%. In the first group, the contents of Al$_2$O$_3$, Fe$_2$O$_3$ and SiO$_2$ range very irregularly according to the CaO content. In the second group, the values of MgO, Al$_2$O$_3$, Fe$_2$O$_3$ and SiO$_2$ are nearly same. Detailed structural analysis of mesoscopic structures and microstructures indicates the five phase of deformation in the study area. The first phase of deformation(D$_1$) is characterized by regional scale isoclinal folds, and bedding parallel S$_1$ axial plane foliation which is locally developed in the mudstone and sandstone. Based on the observations of microstructures, S$_1$ foliations appear to be developed by grain preferred orientation accompanying pressure-solution. During second phase of deformation, outcrop scale E-W trending folds with associated foliations and lineations are developed. Microstructural observations indicate that crenulation foliations were formed by pressure-solution, grain boundary sliding and grain rotation. NNW and SSE trending outcrop scale folds, axial plane foliations, crenulation foliations, crenulation lineations, intersection lineations are developed during the third phase of deformation. On the microscale F$_3$ fold, axial plane foliations which are formed by pressure solution are well developed. Fourth phase of deformation is characterized by map scale NNW trending folds. The pre-existing planar and linear structures are reoriented by F$_4$ folds. Fifth phase of deformation developed joints and faults. The distribution pattern of the limestones is mostly controlled by F$_1$ and F$_4$ folds.

• Journal of Mushroom
• /
• v.11 no.4
• /
• pp.219-225
• /
• 2013

This study was carried out to investigated optimum mixing ratio of Korean natural Juglans mandshurica using as functional plants. Total nitrogen and carbon source of J. mandshurica was 0.21% and 46.0%, respectively and C/N ratio was 219. Total nitrogen source and pH of substrate mixed with J. mandshurica was 2.3~2.9 and 5.0, respectively. The contents of CaO, MgO and $Na_2O$ at J. mandshurica media were higher at harvest media than inoculation media. Mycelial growth was the fastest at J. mandshurica 20%, and slower by increase of J. mandshurica substrate. Yields of fruiting body show the highest to 163 g/850 mL of medium which are addition 10% of J. mandshurica sawdust, and diameter and thick of pileus were the highest, too. The L value of pileus and stipes were increased by increase of J. mandshurica substrate, but there was no significant difference in the a-value and the b-value. The contents of $P_2O_5$ and $K_2O$ of fruiting body were increased at J. mandshurica substrate, but there was no significant difference in contents of CaO, MgO and $Na_2O$. The contents of Cu of fruiting body was decreased by increase of J. mandshurica substrate, but Fe, Mn and Zn were increased.

• Korean Journal of Soil Science and Fertilizer
• /
• v.30 no.1
• /
• pp.89-93
• /
• 1997

To determine the optimum levels of soil phosphorus and potassium for the carrot growth and to investigate the relationship between the quality of carrot root and, P and K contents in soil, carrot was planted in $1m^2$ bottomless pot with five levels of P and K. Maximum root weight was harvested in the plots with 425mg/kg of available P as $P_2O_5$ and $0.72cmol^+/kg$ of exchangeable potassium as K in soil at carrot shoot elongation stage. The concentrations of P and K in harvested carrot root were high in the plots with 359-396 mg/kg of available $P_2O_5$ and $0.79-0.87cmol^+/kg$ of exchangeable K. Sugar content in carrot root increased to available $P_2O_5$ 284 mg/kg in soil and it decreased as soil potassium increased.

• Korean Chemical Engineering Research
• /
• v.57 no.6
• /
• pp.812-825
• /
• 2019

Two dolomite samples mined from the different mines were calcined using a batch-type microwave kiln ($950/60min^{\circ}C$) to produce $CaO{\cdot}MgO$. The hydration of the $CaO{\cdot}MgO$ samples shows different reactivity. MgO was separated by reacting with a strong acid cation exchange resin using the reactivity of the hydration properties of light dolomite ($CaO{\cdot}MgO$). Calcium ($Ca-(R-SO_3)_2$) was separated from the prepared $CaO{\cdot}MgO$ by the cation exchange resin ($CaO{\cdot}MgO:R-SO_3H=1:12mass%$). High purity MgO (higher than 94 mass %) with unburned $CaCO_3$ (1~2 mass %) was obtained by the separation process. The separated MgO was heated at $950^{\circ}C$ for 60 minutes to afford high purity MgO with MgO content higher than 96%. And High-grade $CaCO_3$ was prepared from the reaction with calcium adsorbed resin ($Ca-(R-SO_3)_2$) and NaOH, $CO_2$ gas.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
• /
• v.13 no.2
• /
• pp.51-58
• /
• 2007

This research investigated the effect of different onggi containers (Korean earthenware) on the ripening of kochujang (Korean hot pepper paste). The physical characteristics of 'onggi', were evaluated as function of manufacturing variables such as raw material soils (onggi-specific soil, red brown soil, and fine powdered soil) and galzing treatments. The physical properties were then related to the compositional quality changes of the kochujang fermented at $30^{\circ}C$ for 4 months. The porosity of the onggi containers seems to be increased by the content of finer raw soil rather than the chemical component of soil (amount of CaO, MgO, $K_2O$ and $Na_2O$, acting as melting aid in the firing). Natural glaze was measured to contain higher contents of CaO, MgO, $K_2O$ and $Na_2O$ than the other soils, which is desirable property for the fired onggi. The glazed surface showed higher far-infrared radiation emissivity than the non-glazed part. The kochujang fermented in P0-BG (the glazed onggi from 100 % onggi soil) attained higher concentration of reducing sugar, amino nitrogen and nucleotides compared to those in the other onggis. All of these changes of kochujang in P0-BG resulted in significantly better sensory quality than the other treatments.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.15 no.1
• /
• pp.9-14
• /
• 1986

Fuji and Jonathan apples were stored at cold room and at CA storage conditions of $3%O_2-2%CO_2$ for Jonathan and $4%O_2-3%CO_2$ for Fuji for 8 months, and then tranferred to air at $20^{\circ}C$, 70%RH to compare the some factors related to texture of the apples stored at different storage conditions during exposure at $20^{\circ}C$. Total pectin content and firmness of the apples reduced, considerably with concomitant increases of water-soluble pectin content and polygalacturonase activity during exposure at $20^{\circ}C$ after storage. And the changes were much more serious in the first 5 days than any other period and in the apples stored at cold room, especially in Jonathan than the apples stored at CA storage conditions. From the sensory test the apples stored at cold room maintained acceptable quality for 5days after removal from storage condition. The acceptability from the test was lenghtened for more than 5 days in Jonathan and more than 10 days for Fuji stored at CA storage conditions. when compared with those of the apples stored at cold room.

• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.30 no.2
• /
• pp.66-72
• /
• 2020

The difference of plasma resistance between the CAS glass bulk and coating films were compared. Plasma resistance was confirmed by analyzing the etch rate and the microstructure of the surface when the CAS glass bulk and the glass coating film were etched with CF₄/O₂/Ar plasma gas. CAS glass coating film was etched up to 25 times faster than the glass bulk. A statistically high correlation between the surface roughness and the etching rate of the coating film was derived, and thus, the high surface roughness of the coating film was determined to cause rapid etching. In addition, cristobalite crystals that has a low Ca content and a high Si content, was foamed on the glass coating film. Therefore, the CAS glass coating film is considered to have low plasma resistance compared to the glass bulk.

• Economic and Environmental Geology
• /
• v.40 no.6
• /
• pp.727-738
• /
• 2007

The present study investigation the geochemical characteristics of the stream sediments in the Unbong area was conducted to enable a understanding the natural background and a prediction the prospects of geochemical disaster as a result of that bed rocks(mylonitic granites, Kim et al., 1992). We systematically collected seventy three stream sediments samples by wet sieving along the primary channels. Major, trace and rare earth element(REE) concentrations, combined with mineralogical characteristics, were determined by XRD, XRF, ICP-AES and NAA analysis methods. Major element concentrations for the stream sediments in the Unbong area were $SiO_2\;36.94{\sim}65.39wt.%,\;Al_2O_3\;10.15{\sim}21.77wt.%,\;Fe_2O_3\;3.17{\sim}10.90wt.%,\;CaO\;0.55{\sim}5.27wt.%,\;MgO\;0.52{\sim}4.94wt.%,\;K_2O\;1.38{\sim}4.54wt.%,\;Na_2O\;0.49{\sim}3.36wt.%,\;TiO_2\;0.39{\sim}1.27wt.%,\;MnO\;0.04{\sim}0.22wt.%,\;P_2O_5\;0.08{\sim}0.54wt.%$. Trace and REE concentrations for the stream sediments were $Cu\;4.8{\sim}134ppm,\;Pb\;24.2{\sim}82.5ppm,\;Sr\;95.9{\sim}739ppm,\;V\;19.9{\sim}124ppm,\;Zr\;52.9{\sim}145ppm,\;Li\;25.2{\sim}3.3ppm,\;Co\;3.87{\sim}50.0ppm,\;Cr\;17.4{\sim}234ppm,\;Hf\;3.93{\sim}25.2ppm,\;Sc\;4.60{\sim}20.6ppm,\;Th\;3.82{\sim}36.9ppm,\;Ce\;45.7{\sim}243ppm,\;Eu\;0.89{\sim}2.69ppm,\;Yb\;1.42{\sim}5.18ppm$. According to the comparison of average major element concentrations, CaO, $Na_2O\;and\;K_2O$ contents are higher in stream sediments than in bed rocks(mylonitic granites, Kim et al., 1992) $Al_2O_3\;and\;SiO_2$ contents show good correlation both stream sediments and bed rocks(mylonitic granites, Kim et al., 1992). Yb and Eu in the stream sediments show a positive correlation with $SiO_2$. In contrast, the stream sediments display a negative correlation.

• Food Science and Preservation
• /
• v.8 no.1
• /
• pp.16-22
• /
• 2001

The study was performed to investigate the effects of delayed gamma-irradiation and CA storage on the keeping quality of chestnuts. Chestnuts peviously stored for 3 months at 0$^{\circ}C$ were irradiated at 0 to 0.25 kGy of Co$\^$60/ gamma rays and then stored for 6 months under CA conditions of 3% O$_2$ and 5% CO$_2$ or air at 0$^{\circ}C$. Delayed gamma-irradiation completely inhibited the sprouting of chestnuts, and tore reduced the rotting rate by the combination with CA storage. The weight loss was reduced by delayed gamma-irradiation and CA storage. Hunter L and b values of flesh surface of the chestnuts stored under CA were higher than those of samples stored under air regardless of gamma irradiation. Vitamin C, total sugar and reducing sugar contents decreased immediately after irradiation Vitamin C and reducing sugar contents after 6 months of storage were lower in the samples kept under CA than in those under air. Results indicated that delayed gamma-irradiation after harvest and subsequent CA storage showed inhibitory effects against the development of saluting and rotting and the loss of weights and surface flesh color changes in chestnuts.

• Korean Journal of Food Science and Technology
• /
• v.35 no.5
• /
• pp.865-870
• /
• 2003

The effects of storage atmosphere on the physicochemical and organoleptic properties of Asian pears (Pyrus pyrifolia Nakai cv. Niitaka) were investigated. The pears were stored at $0^{\circ}C$ for up to 8 months under CA conditions (3 kPa $O_2$＋1 kPa $CO_2$, 1 kPa $O_2$+5 kPa $CO_2$, 1 kPa $O_2$+1 kPa $CO_2$) controlled by a static system or air (21 kPa $O_2$+0 kPa $CO_2$). CA conditions retarded the loss of weight, flesh firmness, organoleptic properties (appearance, aroma, sweetness, texture), and the development of injuries in the fruits during storage. Low $O_2$ plus high $CO_2$ conditions maintained the highest flesh firmness. In addition, low $O_2$ reduced injuries more than the other conditions. Skin color (lightness, chroma, hue), soluble solids, titratable acidity, pH and vitamin C were unaffected by storage atmosphere.