• The Korean Journal of Mycology
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• v.32 no.1
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• pp.23-30
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• 2004

Neutral salt-soluble, hot water-soluble and methanol-soluble materials (hereinafter referred to Fr. NaCl, Fr. HW and Fr. MeOH, respectively) were extracted from sclerotium of Grifola umbellata. The Fr. NaCl and Fr. HW did not show any direct cytotoxicity against NIH3T3, Sarcoma 180 and MCF-7, but Fr. MeOH showed cytotoxicity against these cell lines at the concentration of $1,000\;{\mu}g/ml$. Intraperitoneal injection with Fr. NaCl showed antitumor effect with life prolongation of 66.7% and decrease the number of Sarcoma 180 cells of 54.2% in mice inoculated with Sarcoma 180. Fr. NaCl improved the immunopotentiation activity through alternative complement pathway and the alkaline phosphatase activity by $85.05{\sim}88.73%$ and 6 folds, respectively. The number of peritoneal exudate cells and the circulating leucocytes were increased by 1.7 and 3.6 folds in the Fr. NaCl treating group compared with the control group, respectively. The weight of immunoorgans such as liver, spleen and thymus were also gradually increased. The hematological analysis of the Fr. NaCl group was similar with that of the control group. The total polysaccharide and protein contents of Fr. NaCl were 98.25% and 1.44%, respectively. These results indicate that the antitumor activity of Fr. NaCl was exerted through immunopotentiation, but not through cytotoxicity against the tumor cells.

• The Korean Journal of Mycology
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• v.32 no.1
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• pp.39-44
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• 2004

Gastrodia elata has been cultivated using mycorrizal fungi including Armillaria mellea as an energy source (myco-hetrotrophy) because it is aphyllous and achlorophyllous archid. But the yields of G. elata have been recently decreased owing to the degeneration of spawn tuber arised from successive asexual reproduction. Therefore, this study was carried out to solve this degeneration by seed germination, namely sexual reproduction. The seed germination of G. elata was excellent on the fallen leaves medium of oak tree. The fruetification rate of the capsule of G. elata by artificial pollination was 94.1% and better than natural pollination. The living weight of capsules of G. elata suitable for seeds germination was above 31 mg. The middle-matured seeds and matured seeds of capules were largely germinated, while the immatured seeds was small germinated. The storage temperature of the cropped capsules suitable for a favorable seed germination was $0{\sim}5^{\circ}C$ and the storage period of it was one month.

• Journal of the Korea Concrete Institute
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• v.13 no.5
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• pp.438-446
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• 2001

Recently, porous concrete has been used for the purpose of decreasing the load of earth environment. It consists solely of cement, water and uniform-sized coarse aggregate. And its fundamental properties will be considerably affected by the physical properties of aggregate because the aggregate occupies for the most part in its mix proportion. For such a reason, this study was carried out to investigate the influence of the sizes and kinds of aggregate for the fundamental properties of porous concrete. It showed that the fundamental properties of porous concrete were the similar value in all sizes of aggregate except in the case of using the 2.5∼5㎜ aggregate and were varied according to the kinds of aggregate. In particular, compressive strength of porous concrete using 2.5∼5㎜ aggregate was more higher than that using other aggregate, and its void ratio and coefficient of permeability was lower. And the maintenance capacity of permeability of porous concrete was varied by the sizes and the kinds of aggregate. In particular, it was greatly decreased in case of using the 2.5∼5㎜ aggregate. And unlike dynamic modulus of elasticity of ordinary concrete, that of porous concrete was very high value in early ages and was slowly increased after that time.

• Journal of Korean Society of Steel Construction
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• v.29 no.6
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• pp.487-495
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• 2017

Recently rapid-transit railway systems have been constructed in many developing countries due to its advantages in congestions and environmental problems. Railway bridges show many different aspects compared to road bridges and passenger comfort and traffic safety are one of them. In particular, deflection and acceleration due to repeated vibration characteristics have a structural weakness that can cause undesirable response. Especially steel railway bridges have been known to have weaknesses due to its relatively light weights compared to concrete bridges. The purpose of this study is to analyze the dynamic response of steel box girder bridges due to passing trains then propose the appropriate method to mitigate the level of vibration in terms of accelerations. Three steel railway bridges are tested and the numerical model to analyze the dynamic response of the bridge by passing train are developed. For the verification of the model, the natural frequency extracted using the acceleration data measured in the bridge is compared with the natural frequency of the numerical model. To mitigate the acceleration level of the bridge, parametric studies are performed to find the effectiveness of the method. Based on the analysis, the appropriate method is proposed for decreasing the acceleration of the bridge for passenger comfort and traffic safety.

• Journal of the Korean Institute of Gas
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• v.22 no.2
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• pp.46-51
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• 2018

Hydrogen sulfide from landfill and sewage treatment plant is a major odor component and causes many civil petitions. Rapidly developing industries release hydrogen sulfide, an odorous gas, to the atmosphere. This study aims to develop a $10{\mu}mol/mol$ concentration level hydrogen sulfide primary standard gas for odor measurement. The hydrogen sulfide gas was prepared at a nominal concentration of $10{\mu}mol/mol$ in nitrogen using the gravimetric method described in ISO 6142. Replicate standard gases were produced in 4 aluminium cylinders, and their concentrations were verified by GC-AED. The uncertainty of production was less than 0.50 %, and the variation of the 4 replicates was 0.22 %. The wall adsorption of hydrogen sulfide in cylinders was 0.10 % at 1500 psi, and the concentration was estimated to be long-term stable for one year. The relative expanded uncertainty of the preparation consistency, adsorption and long-term stability of this hydrogen sulfide standard gas was less than 1.05 % (95 % of confidence level, k=2).

• Journal of the Korea Organic Resources Recycling Association
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• v.9 no.4
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• pp.81-88
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• 2001

This experiment was carried out to evaluate the effect of residual food compost application on plant growth and physicochemical properties of soil when residual food compost made from the composting process as part of organic waste recycling was applied in soil as variable rate. The treatments were composed non-fertilizer treatment, control treatment applied with pig compost $20Mg(D.W.)ha^{-1}$, and residual food compost treatments each of applied with 20, 40, 60, $80Mg(D.W.)ha^{-1}$ and were randomized complete block design with three replication. Soil pH after experiment was more increased as more increase application of residual food compost. Other chemical properties of soil including EC were also showed the similar results. The plant growth in treatments applied much of residual food compost at the early growth stage was very damaged and these results were proved at the first growth measurement. Production of the red pepper especially reduced in treatments taken growth demage at the early stage and that of $20Mgha^{-1}$ treatment almost same as control treatment. Bulk density was reduced but porosity was increased according to increase of residual food compost application. Considering the reduction of red pepper production and the demage of growth at the early stage by plenty of salt and water soluble application volume of residual food compost was not permitted over of $30Mgha^{-1}$. Additively, to settle the application volume of residual food compost and to evaluate the plant growth and changes of physicochemical properties of soil, the results taken from continual applying is concluded more important than single application.

• Food Science and Preservation
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• v.19 no.1
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• pp.67-73
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• 2012

This study was carried out to investigate the packaging status of the $Agaricus$ $bisporus$ mushrooms and the benefits of storing them after precooling to improve their distribution system using small packages. The packaging status of the $Agaricus$ $bisporus$ mushrooms was surveyed at a farm, a department store, a wholesale market, and a supermarket from May to September 2011. The packaging materials that were used were PS, carton, PP, LDPE, PLA, and PVC. The harvested $Agaricus$ $bisporus$ mushrooms were precooled at $4^{\circ}C$ for three hours and were then stored at $20^{\circ}C$ for three days. The weight loss rate of the precooled sample was slightly lower than that of the unprecooled sample; conversely, the L value of the precooled sample was higher than that of the unprecooled sample. The ${\Delta}E$ value was lowest in the precooled sample after packaging. The precooling process effectively prolonged the shelf life and enhanced the quality of the$Agaricus$ $bisporus$ mushrooms.

• Journal of the Korea Organic Resources Recycling Association
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• v.9 no.2
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• pp.101-107
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• 2001

The experiment was conducted to investigate the agricultural utility of macro-porous calcium-silicate rnineral(CellCaSi) as topsoil mixture, as well as to estimate as a soil conditioner. The bulk density of CellCaSi which is consisted of various particle sizes ranging from 1mm to 3.35mm was about $0.42g/cm^3$, and its maximum porosity was approximately 81.4%. We also investigate gerrnination rates for Cabbage and Lettuce to obtain the suitable mixing ratios of CellCaSi with topsoil. Among 4 different mixing ratios, the germination rates of ropsoil mixed with 10% of CellCaSi were 94.1% and 64.6% for Cabbage and Lettuce, respectively resulted in the mosr suitable for germination. The growth rates for Cabbage and Lettuce showed thar 10% and 20% of CellCaSi treatments signification influenced the fresh weight. To observe the adsorption capacity of CellCaSi, CellCaSi was treated with a chemical fertlizer(N:P:K=18:18:18). lncreasing the contents of N, P and K, the amounts of adsorption by CellCaSi for these element also increased. The most suitable types nutrient resources for growth condition of Cabbage, and Lettuce were Fer-1 and Fer-0.5.

• Journal of the Korean GEO-environmental Society
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• v.15 no.11
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• pp.53-59
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• 2014

It has been generally recognized that the conventional rockfall protection nets have several problems to actual field application in the aspect of shock absorption, lack of pullout bearing capacities, and net damages. Because of the recognition, authors have tried to develop a new rockfall protection system consisted of shock absorption parts and hexagonal net configuration. In the previous research by the authors, the performance of the newly developed rockfall protection system has been investigated through the laboratory tests and the full-scale testing. In this study, subsequently, numerical analysis program is organized to make a confirmation of the structural stability and performance. For the correct design procedure of the hexagonal net system, it is essential to understand the various mechanical behavior of the entire system. It is also important to be reproduced the systematic characteristics of the system acquired by laboratory and full-scale testing by numerical analysis in order to carry out the numerical experiment to understand various mechanical behavior of the system. As a conclusion, the hexagonal net has better performance in mechanical and physical behavior compared with that of the rectangular net. Furthermore, due to the hexagonal net shows a good performance in aspect of the load distribution, it gives a good alternative in long-term management of the rockfall protection net.

• KSBB Journal
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• v.21 no.6 s.101
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• pp.433-438
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• 2006

A fibrinolytic enzyme gene (BCF-1) was subcloned to the pEB vector which is high expression vector in the Bacillus host. The enzyme was purified by using FPLC after ammonium sulfate precipitation. The enzyme was oral-administrated to the rat and checked the bleeding time, blood clotting time and fibrinolytic effect of the serum. In the bleeding time retardation test, it was longer about 1.7 fold in the feeding rat than without feeding. The serum of rat feeded with the enzyme had the fibrinolytic activity from 1 hour to 3 hours after oral-administration. After 3 hours from feeding, the fibrinolytic activity was decreased gradually. Also blood clotting time after bleeding was longer than that of control rat. The enzyme could be detected at band of 30,000 Da in the blood by western blotting. The enzyme was not harmful to the all internal organs of the rats. Taken together, the enzyme originated from B. subtilis BB-1 can be a candidate to develop the drug for thrombosis, arteriosclerosis and myocardial infarction.