• Magazine of the Korean Society of Agricultural Engineers
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• v.22 no.1
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• pp.53-66
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• 1980

The research work is concerned with the analytical and experimental studies on the heat transfer phenomenon around the underground concrete digester used for biogas production Systems. A mathematical and computational method was developed to estimate heat losses from underground cylindrical concrete digester used for biogas production systems. To test its feasibility and to evaluate thermal parameters of materials related, the method was applied to six physical model digesters. The cylindrical concrete digester was taken as a physical model, to which the model,atical model of heat balance can be applied. The mathematical model was transformed by means of finite element method and used to analyze temperature distribution with respect to several boundary conditions and design parameters. The design parameters of experimental digesters were selected as; three different sizes 40cm by 80cm, 80cm by 160cm and l00cm by 200cm in diameter and height; two different levels of insulation materials-plain concrete and vermiculite mixing in concrete; and two different types of installation-underground and half-exposed. In order to carry out a particular aim of this study, the liquid within the digester was substituted by water, and its temperature was controlled in five levels-35。 C, 30。 C, 25。 C, 20。C and 15。C; and the ambient air temperature and ground temperature were checked out of the system under natural winter climate conditions. The following results were drawn from the study. 1.The analytical method, by which the estimated values of temperature distribution around a cylindrical digester were obtained, was able to be generally accepted from the comparison of the estimated values with the measured. However, the difference between the estimated and measured temperature had a trend to be considerably increased when the ambient temperature was relatively low. This was mainly related variations of input parameters including the thermal conductivity of soil, applied to the numerical analysis. Consequently, the improvement of these input data for the simulated operation of the numerical analysis is expected as an approach to obtain better refined estimation. 2.The difference between estimated and measured heat losses was shown to have the similar trend to that of temperature distribution discussed above. 3.It was found that a map of isothermal lines drawn from the estimated temperature distribution was very useful for a general observation of the direction and rate of heat transfer within the boundary. From this analysis, it was interpreted that most of heat losses is passed through the triangular section bounded within 45 degrees toward the wall at the bottom edge of the digesten Therefore, any effective insulation should be considered within this region. 4.It was verified by experiment that heat loss per unit volume of liquid was reduced as the size of the digester became larger For instance, at the liquid temperature of 35˚ C, the heat loss per unit volume from the 0. 1m$^3$ digester was 1, 050 Kcal/hr m$^3$, while at for 1. 57m$^3$ digester was 150 Kcal/hr m$^3$. 5.In the light of insulation, the vermiculite concrete was consistently shown to be superior to the plain concrete. At the liquid temperature ranging from 15。 C to 350 C, the reduction of heat loss was ranged from 5% to 25% for the half-exposed digester, while from 10% to 28% for the fully underground digester. 6.In the comparison of heat loss between the half-exposed and underground digesters, the heat loss from the former was fr6m 1,6 to 2, 6 times as much as that from the latter. This leads to the evidence that the underground digester takes advantage of heat conservation during winter.

• Applied Biological Chemistry
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• v.51 no.2
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• pp.142-147
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• 2008

Nuruk is the Korean traditional Koji that contains various microorganisms and has been used to make the traditional fermented foods including alcoholic beverages. Rhizopus oryzae KSD-815 was isolated from the alcohol-fermenting Nuruk used for manufacturing traditional alcohol. In this study, the authors reported the isolation and identification of four lipids from the Nuruk (Rhizopus oryzae KSD-815) that inoculated wheat with Rhizopus oryzae KSD-815. The dried and powdered Nuruk (Rhizopus oryzae KSD-815) were extracted three times at room temperature with 80% aqueous MeOH. The extracts were partitioned with EtOAc, n-BuOH, and water, successively. The EtOAc extract was suspended in 80% MeOH and partitioned repeatedly with n-hexane. From the n-hexane fraction, four lipids were isolated through the repeated silica gel and ODS column chromatographies. According to the results of physico-chemical data including NMR, GC and MS, the chemical structures of the compounds were determined as linolenic acid methyl ester (1), palmitic acid methyl ester (2), linoleic acid (3), palmitic acid (4). Cytotoxicity was evaluated in huamn breast cancer cells, MDA-MB-231 and human hepatocarcinoma, SK-HEP-1 cells using MTT assay. Exposure of compounds 1 and 3 led to a dose-dependent inhibition of cell viability in both cancer cell lines. In addition, treatment of RAW264.7 cells with compound 3 caused inhibition of lipopolysaccharide/interferon-${\gamma}$-induced nitric oxide production.

• Korean Journal of Plant Resources
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• v.26 no.1
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• pp.9-18
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• 2013

The aim of this study is to provide the basic data for yacon [Samallanthus sonchifolius (Poepp. & Endl.) H. Robinson] in dietary food. The nutritional compositons, such as protein, ash, carbohydrate, dietary fiber, vitamin and fructooligosaccharide, were analyzed for 4 yacon germplasm lines. Yacon has low calories with only 46~56 kcal/100 g. The contents of water, fat, ash, protein, carbohydrate and dietary fiber were ranged 85.9~86.8%, 0.1~0.2%, 0.2~0.3%, 0.5~0.7%, 12.2~13.1% and 1.05~1.14%, respectively. The iodine-starch test did not show any color or precipitation reaction, which indicates that yacon has no starch content. However, in the absence of starch, yacon is rich in fluctooligosaccharide, which is between 9.6~11.1%. Maltose is present in the larger amount, followed by sucrose, glucose, and fructose in terms of free sugars. The analysis of minerals revealed that yacon contains potassium in the larger amount of 141~176 mg/100 g F.W., followed by magnesium at 8.2~10.6 mg, calcium, and sodium representing the least present mineral. Yacon proved to have a total of 17 types of amino acids, which are between 404.0~581.8 mg per 100 g of yacon. Glutamic acid, the main sweetening component, is present in the large amount of 94.0~182.2 mg/100 g F.W., followed by aspartic acid, arginine, and alanine. The proportion of the essential amino acid was 24.8~33.6%. Results of analysis also showed that yacon contains 0.001~0.024 mg, 0.03~0.11 mg, 0.02~0.3 mg, 0.3~0.4 mg and 14.1~20.6 mg of ${\beta}$-carotene, thiamin, riboflavin, niacin, and ascorbic acid, respectively. It is also likely to be highly used as functional food material in the future because it is abundant in both fluctooligosaccharide and antioxidants which are important functional components.

• Journal of the Korean Society of Groundwater Environment
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• v.1 no.1
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• pp.23-32
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• 1994

To determine the apparent equilibrium constants, K$_{ad,app}$, for the adsorption reactions of trace metals on amorphous iron oxyhydroxide (AIO) in the Taebag coal mine area, time-adsorption and pH-adsorption experiments were performed for a selected bottom sediment mainly comprised of AIO from the study area. The results from the adsorption experiments indicate that most of the trace metals, except Pb, achieve equilibrium states with AIO and thus, the calculated K$_{ad,app}$ may represent the true apparent equilibrium constants. K$_{ad,app}$ and the stoichiometric coefficients of proton, x, of the adsorption reactions between the trace metals and AIO were respectively calculated from the intercepts and slopes of the regression lines of log($\Gamma$/ ［M］$_{aq}$)against pH provided by pH-adsorption experiments. The calculated K$_{ad,app}$ this study has the values of the range from 10$^{－4.5}$ to 10$^{2.75}$ , which is much different from the reported values by other investigators for simple experimental systems. K$_{ad,app}$ of this study is more or less close but not exactly pertinent to the estimated values for the other natural systems. It indicates that K$_{ad,app}$ for the adsorption reactions in the aquatic system in the study area is unique and thus should be determined befor the adsorption modelling. The calculated x of this study has the values of the range from -0.3 to 0.7, which is also much different from what most geochemists generally accept. The discrepancy in x may be due to the competition among different kinds of ionic species on the adsorption site or simulataneous occurrence of different kinds of adsorption reactions. The results from this study should help construct an appropriate adsorption model for the aquatic systems polluted by the coal mine drainage in the Taebag area. With the constructed model, one can describe the concentration variations of trace metals due to the adsorption in the system, which is an essential part of the investigation on the water quality affected by coal mine drainage in the Taebag coal field.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.1
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• pp.25-31
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• 2009

This study was carried out to investigate the mutagenic, antimutagenic, cytotoxicity and antitumor effects of Adenophora triphylla (AT). AT was extracted with 70% ethanol and then further fractionated to hexane, chloroform, ethyl acetate, butanol and water. Antimutagenic, cytotoxicity and antitumor effects of AT extracts were measured by using Ames test, SRB method, and the tumor growth inhibition test. AT extracts did not show any mutagenicity in the Ames test; however, 70% ethanol extracts and its fractions had strong antimutagenic effects against mutation induced by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) and 4-nitroquinoline-1-oxide (4NQO). The ethyl acetate fraction of AT (200 ${\mu}g$/plate) showed approximately 66.5% inhibitory effect on the mutagenesis induced by 4NQO against TA98 strain, whereas 83.3% and 75.1% inhibitions were observed on the mutagenesis induced by MNNG and 4NQO against TA100 strain. In anticancer effects, the cytotoxicity of AT extract and its fractions against cancer cell lines including human cervical adenocarcinoma (HeLa), human hepatocellular carcinoma (Hep3B), human breast adenocarcinoma (MCF-7), human gastric carcinoma (AGS), human lung carcinoma (A549) and transformed primary human embryo kidney (293) were investigated. The treatment of 1 mg/mL AT ethyl acetate faction had the highest cytotoxicity of 79.9%, 74.9%, 66.0%, 71.0% and 74.3% against HeLa, Hep3B, MCF-7, AGS and A549 cells, respectively. In contrast, the extract and its fractions showed only $3{\sim}36%$ cytotoxicity for a normal human kidney cell line (293). In vivo anti-cancer effect of Adenophora triphylla extract was tested using Balb/c mice transplanted sarcoma-180 cells. Adenophora triphylla ethyl acetate fraction showed the highest inhibition rate of 37.2% at the 50 mg/kg concentration.

• Korean Journal of Food Science and Technology
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• v.35 no.1
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• pp.125-131
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• 2003

Physiological activities of hot water extracts of 10 commercial instant curry powders and 6 spices, were investigated. All spice extracts except ginger showed significant antioxidant activities on the autoxidation of linoleic curry acid (p＜0.01). Antioxidant activities of clove and fennel were significantly higher than ${\alpha}-tocopherol$, instant curry powders, and other spices, Red pepper $(52.8{\pm}2.13%)$, clove, and coriander showed significant inhibitory activities against angiotensin-I-converting enzyme (p＜0.001). Cytotoxic effects of instant curry powder and spices against human cancer cell lines were examined through MTT assay. Black pepper $(29.31{\pm}2.21%\;cytotoxic\;rate)$ and cardamon $(19.41{\pm}3.92%)$ were effective against MCF-7 (p＜0.01), Clove $(42.92{\pm}5.57%)$ against HeLa (p＜0.01). Ginger $(34.21{\pm}1.11%)$, cardamon, and black pepper against A172 (p＜0.001), garlic $(82.88{\pm}0.53%)$ against SN12C (p＜0.001), garlic $(71.63{\pm}0.38%)$, red pepper, ginger, fenugreek, SPC, cumin, and MPC against SNU-638 (p＜0.001), and cassia $(82.84{\pm}16.92%)$ against A549 (p＜0.001).

• Korean Journal of Fisheries and Aquatic Sciences
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• v.24 no.4
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• pp.215-228
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• 1991

In the East Sea of Korea the vertical structure functions of the temperature field were evaluated and the characteristic thermal zone was classified by the use of the empirical orthogonal function(EOF) method. The East Sea of Korea within the hydrographic lines of 10-107 of the Fisheries Research and Development Agency of Korea(FRDA) can be divided into three thermal regions by the characteristics of the vertical temperature variability. They are the North Korean Cold Current(NKCC) region near the coast which extends parallel to the north-south direction, the Warm-Core(WC) region which dominates almost all the hydrographic stations of the Line 104 of the FRDA and occupies a few stations of the Line-103 and -105 with its axis at the Line 104, and the East Korea Warm Current(EKWC) region which is bisected into the northern and the southern part by the WC region, respectively. Considering the two most important modes, $85.20-98.20\%$ of the total variance of temperature variation are explained in the NKCC region, $85.20-92.90\%$ in the EKWC region, and$85.50-91.70\%$ in the WC region. The first mode has its peak value at the surface with the annual cycle of variation. The spatial pattern of the first mode portrays a coherent vertical variation in the EKWC region and a clear anti-correlation both in the NKCC region and in the WC region where the zero-crossing depths are loom and 200m, respectively. The second mode of the NKCC region is particularly noticeable, haying its peak at loom with coherent vertical variation. To study the time dependency of the vertical structure functions, the extended EOF(EEOF) method was used. The persistence of the first mode is less than 4 months in the study area. The annual variation of the first mode in the NKCC region is different from those in the WC region and in the EKWC region.

• The Journal of Engineering Geology
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• v.14 no.1
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• pp.29-46
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• 2004

It is important to identify geometries of fracture that act as a conduit of fluid flow for characterization of ground water flow in fractured rock. Fracture geometries control hydraulic conductivity and stream lines in a rock mass. However, we have difficulties to acquire whole geometric data of fractures in a field scale because of discontinuous distribution of outcrops and impossibility of continuous collecting of subsurface data. Therefore, it is needed to develop a method to describe whole feature of a target fracture geometry. This study suggests a new approach to develop a method to characterize on the whole feature of a target fracture geometry based on the Fourier transform. After sampling of specimens along a target fracture from borehole cores, effective frequencies among roughness components were selected by the Fourier transform on each specimen. Then, the selected effective frequencies were averaged on each frequency. Because the averaged spectrum includes all the frequency profiles of each specimen, it shows the representative components of the fracture roughness of the target fracture. The inverse Fourier transform is conducted to reconstruct an averaged whole roughness feature after low pass filtering. The reconstructed roughness feature also shows the representative roughness of the target subsurface fracture including the geometrical characteristics of each specimen. It also means that overall roughness feature by scaling up of a fracture. In order to identify the characteristics of permeability coefficients along the target fracture, fracture models were constructed based on the reconstructed roughness feature. The computation of permeability coefficient was performed by the homogenization analysis that can calculate accurate permeability coefficients with full consideration of fracture geometry. The results show a range between $10^{-4}{\;}and{\;}10^{-3}{\;}cm/sec$, indicating reasonable values of permeability coefficient along a large fracture. This approach will be effectively applied to the analysis of permeability characteristics along a large fracture as well as identification of the whole feature of a fracture in a field scale.

• Journal of Practical Agriculture & Fisheries Research
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• v.16 no.1
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• pp.193-206
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• 2014

The objectives of the project are to increase farmers' income through GAP and to reduce the loss of agricultural produce, for which the Korean partner takes a role of transferring needed technologies to the project site. To accomplish the project plan, it is set to implement the project with six components: construction of buildings, installation of agricultural facilities, establishment of demonstration farms, dispatching experts, conducting training program in Korea and provision of equipments. The Project Management Committee and the Project Implementation Team are consisted of Korean experts and senior officials from Department of Agriculture, Myanmar that managed the project systematically to ensure the success of the project. The process of the project are; the ceremony of laying the foundation and commencing the construction of training center in April, 2012. The Ribbon Cutting Ceremony for the completion of GAP Training Center was successfully held under PMC (MOAI, GAPI/ARDC) arrangement in SAl, Naypyitaw on June 17, 2012. The Chairman of GAPI, Dr. Sang Mu Lee, Director General U Kyaw Win of DOA, officials and staff members from Korea and Myanmar, teachers and students from SAl attended the ceremony. The team carried out an inspection and fixing donors' plates on donated project machineries, agro-equipments, vehicles, computers and printer, furniture, tools and so forth. Demonstration farm for paddy rice, fruits and vegetables was laid out in April, 2012. Twenty nine Korean rice varieties and many Korean vegetable varieties were introduced into GAP Project farm to check the suitability of the varieties under Myanmar growing conditions. Paddy was cultivated three times in DAR and twice in SAl. In June 2012, vinyl houses were started to be constructed for raising seedlings and finished in December 2012. Fruit orchard for mango, longan and dragon fruit was established in June, 2012. Vegetables were grown until successful harvest and the harvested produce was used for panel testing and distribution in January 2013. Machineries for postharvest handling systems were imported in November 2012. Setting the washing line for vegetables were finished and the system as run for testing in June 2013. New water tanks, pine lines, pump house and electricity were set up in October 2013.

• Analytical Science and Technology
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• v.19 no.6
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• pp.535-543
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• 2006

Being used widely in semiconductor and display manufacturing, $NF_3$ is internationally considered as one of the regulated compounds in emission. Numerous companies have been continuously trying to reduce the emissions of $NF_3$ to comply with the global environmental regulation. This work is made to report the destruction and removal efficiency (DRE) of electrically heated scrubbers and the use rate in process chambers installed in three main LCD manufacturing companies in Korea. As the measurement techniques for $NF_3$ emission, mass flow controlled helium gas was continuously supplied into the equipment by which scrubber efficiency is being measured. The partial pressures of $NF_3$ and helium were accurately measured for each sample using a mass spectrometer, as it is emitted from inlet and outlet of the scrubber system. The results show that the DRE value for electrically heated scrubbers installed before 2004 is less than 52 %, while that for the new scrubbers modified based on measurement by scrubber manufacturer has been sigificentely improved upto more than 95 %. In additon, we have confirmed the efficiency depends on such variables as the inlet gas flow rate, water content, heater temperature, and preventative management period. The use rates of $NF_3$ in process chambers were also affected by the process type. The use rate of radio frequency source chambers, built in the $1^{st}$ and $2^{nd}$ generation process lines, was determined to be less than 75 %. In addition, that of remote plasma source chambers for the $3^{rd}$ generation was measured to be aboove 95 %. Therefore, the combined application of improved scrubber and the RPSC process chamber to the semiconductor and display process can reduce $NF_3$ emmision by 99.95 %. It is optimistic that the mission for the reduction of greenhouse gas emission can be realized in these LCD manufacturing companies in Korea.