• Journal of Environmental Science International
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• v.21 no.1
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• pp.31-39
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• 2012

The objective of this study is to provide pollutant loads delivery ratio for flow duration in Oenam-cheon watershed, which is upstream watershed of Juam Lake. To calculate the delivery ratio by flow duration, rating curves and discharge-loads curves using measured data were established, then Flow Duration Curve(FDC) and pollutant loads delivery ratio curves were constructed. The results show that the delivery ratios for $BOD_5$ for abundant flow($Q_{95}$), ordinary flow($Q_{185}$), low flow($Q_{275}$), and drought flow($Q_{355}$) were 23.9, 12.7, 7.1, and 2.9%, respectively. The delivery ratios of same flow regime for T-N were 58.4, 31.2, 17.2 and 7.1%, respectively. While, the delivery ratios T-P were 17.3, 7.5, 3.4, and 1.1% respectively. In general, delivery ratio of high flow condition showed higher value due to the influence of nonpoint source pollution. Based on the study results, generalized equations were developed for delivery ratio and discharge per unit area, which could be used for ungaged watershed with similar pollution sources.

• The Korean Journal of Mycology
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• v.47 no.4
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• pp.385-392
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• 2019

Currently, plastic bags are being used for sawdust cultivation of shiitake mushroom. However, due to serious environmental problems caused by the use of plastic bags, we studied the efficacy of bottle cultivation method to replace the sawdust bag method. Small detachable plastic bottles (400 g capacity) filled with Quercus spp. sawdust and wheat bran (4:1 w/w) media were incubated for 80 and 120 days. The weight loss (%) of the media was higher for the NIFoS 2464 strain at an approximate light intensity of 300 Lux than light intensity of 500 Lux; the light intensity was associated with the loss of sawdust medium-weight during the cultivation period. The highest yield was observed when the strain was cultivated for 80 days under dark conditions, 40 days under 500 Lux light, and air circulation fan speed of 30 rpm. When incubated for 120 days, mushroom yield in the bottle media was higher at 40 days of light exposure than 20 days of light exposure. In the bottle media incubated for 80 days under dark conditions, the mushrooms fruited due to repetitive water spraying on the top of the media and light stimulation during the fruiting period. The media could be separated from the bottles because the media shrank after the first harvest. These separated plastic bottles could be re-used for mushroom cultivation, thereby reducing the amount of plastic waste.

• The Korean Journal of Pain
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• v.9 no.2
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• pp.399-402
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• 1996

Endoscopic transthoracic sympathectomy (ETS) has recently become estabilished as a successful treatment for severe palmar and axillary hyperhidrosis. Descriptions have been published of neurolytic, operative and alternative endoscopic procedures involving thermocoagulation, laser coagulation, or or nonvideo-assisted ganglionectomy using equipment not widely available, with low morbidity and excellent results. All methods have advantage and disadvantages. A 19-year-old male who suffered from severe hyperhidrosis on face, palms and axillary areas, has been initially treated with stellate ganglion block in other pain clinic. He was transfered to our pain clinic for endoscopic thoracic sympathectomy. The patient was intubated left side 34 Fr. double lumen tube and positioned left semi-lateral position for right sympathectomy. Right side pneumothorax was created by clamping the ipsilateral side of the double lumen tube and aspiration of air. 11-mm trocar was introduced through incision at the third intercostal space in anterior axillary line, and then additional two 11-mm and 5-mm trocar was introduced through second and fifth intercostal space in mid axillary line. The lung was gently retracted and the parietal pleura over the heads of the appropriate ribs excised using 5-mm sharp insulated coagulating microprocesss. The T4, T3, and T2 ganglions, as well as accompanying rami communicantes, and other branchs arising from upper thoracic nerves to the brachial plexus and surrounding tissues were carefully dissected, coagulated. During sympathectomy, skin temperature of middle was continuously monitored. Elevation of palmar skin temperature intraoperatively indicated an adequate sympathectomy with a definite therapeutic effect. A No. 28 Fr. thoracotomy tube was introduced through a troca under video guidance, placed under water seal after the lung was reinflated. the controlateral side was performed same procedure. After bilateral sympathectomy, chest tubes were removed, and then, he was discharged 2 days after operation with great satisfaction. The ETS provides a well-tolerated, cost-effective alternative to thoracic sympathectomy for primary hyperhidrosis and sympathetic mediated neuropathic pain disorder. And T2 ganglion is considered the key ganglion for the treatment of primary hyperhidrosis. The low incidence of compensatory sweating may by explained by the limited extent of the sympathectomy.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.17 no.4
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• pp.299-305
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• 1984

As one trials to utilize sea mussel and anchovy effectively, powdered instant soups were prepared and then their quality stability were examined during storage. Powdered instant soup was made by adding $3\%$ sugar, $20\%$ table salt, $5\%$ monosodium glutamate, $0.2\%$ black pepper and garlic powder to the pulverized dried sea mussel or anchovy. Powdered instant soup products, powderd products, and dried round state sea mussel or anchovy were packed with air in laminated film bag (cellophane/polyester/aluminium foil/polyester: $20{\mu}m/15{\mu}m/7{\mu}m/20{\mu}m,\;13{\times}14cm$). The contents of amino-nitrogen and volatile basic nitrogen of these products were showed little significant variations and also water activity and color value (L, a, b) of these products were little changed during storage. Thiobarbituric acid value increased up to 30 days of storage and then decreased slightly. Comparing the quality of powdered-seasoned products with that of dried round state products, there were no significant differences in stability during storage. Judging from the experimental results, the quality of powdered instant soup of sea mussel and anchovy were stable for 100 days at room temperature($25{\pm}3^{\circ}C$).

• Journal of Environmental Impact Assessment
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• v.27 no.5
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• pp.417-430
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• 2018

Identification and mangement of ecosystem service hotspots are necessary to set environmental policies that include concepts of ecosystem service. Assessment and mapping of ecosystem service hotspot referring areas with high amount of ecosystem services provide essential information to manage ecosystem services effectively. Assessment of hotspots based on regional environmental stakeholders' perception is an useful approach to identify priority areas where management practices are required. This study estimated weights on regulating ecosystem services from regional environmental stakeholders' surveys in Ansan, and then, identified regulating service hotspots with weights. The result indicated that regulating services are, in order of importance, water quality, air quality, erosion, and climate control. The north-eastern forest of Ansan was mainly revealed as an ecosystem service hotspot. Ecosystem service hotspots were spatially distributed similarly regardless of environmental stakeholders' weights. Identification of ecosystem service hotspot with environmental stakeholders' perception can be applied in decision-support tools for ecosystem service management.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 1996.05a
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• pp.91-115
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• 1996

In the recent years, protected horticultural facilities have been modernized and glasshouses are also propagating in Korea, even most vegetables production are conducted in the traditional plastic houses covered with, for example, PVC film for just temperature keeping. It would limit the productivity and competitivity of the vegetable production industry without automatization and high quality year round production. A plant factory, aimed to produce vegetables in the limited areas, was initiated in Christensen farm, Denmark in 1957, and widely propagated in some developed countries. As it has the automatized system which enables to keep optimized environment conditions, it will be the best facility for high quality products as well as year round planned production. However, we have not even started the plant factory production. Since the plant factory is requiring lots of resources, besides plant cultivation technologies, such as environment control, automatic engineering and robotics, our approach to the development of plant factories should be minded on Practical Plant Factories considering our current farming practices and least capital needs rather than blindly employing the advanced technologies from developed countries. Thus, Korean plant factory development can be initiated with year round leaf vegetables production in NFT or DFT cultivation system instead of the moval bed system, in which aerial environment factors such as light, temperature, humidity and CO$_2$ concentration and root environment ones such as solution concentration, temperature, pH and water soluble oxygen shall be automatically controlled. And the seeding, seedling and transplanting operations shall be accomplished in the house entrance, and the harvesting and grading opreations shall be conducted in the house exit. For practical plant factories, environment control technologies including artificial light source, illumination and air conditioning, automatic management for nutrient solution and automatic production line of moval bed system, transplanting and harvest should be developed along with researches on the cost reduction of factory building construction.

• Journal of the Korea Concrete Institute
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• v.16 no.1 s.79
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• pp.1-9
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• 2004

This paper represents the permeability of chloride ions and the corrosion performance in the concrete blended with granulate blast furnace slag exposed to chloride environment. An ordinary cement (type I ) and sulfate resisting cement(type V) were used for the experiment. The two cements were combined with $0\%$, $25 \%$, $40\%$, and $55\%$ of the granulated blast furnace slag. The accelerated permeability tests of chloride ions were performed in accordance with ASTM C1202, and the accelerated corrosion tests of steel were carried out by using the method of immersion/drying cycles. After water curing 28 days, 56 days and 91 days, these tests were conducted until 30 cycles. In every cycle, test specimens were wetted in $3\%$ NaCl solution for three days and dried again in $60^{\circ}C$ air for four days. As an experimental results, the diffusion coefficient of chloride ions of the ordinary cement Concrete Combined granulated blast furnace slag was much lower than that of non granulated blast furnace slag concrete. Moreover, the diffusion coefficient of chloride ions of sulfate resisting cement concrete was higher than that of ordinary cement concrete. On the basis of the results of accelerated corrosion tests, corrosion resistance of the concrete mixed with granulated blast furnace slag shows good to corrosion resistance, however, the concrete with sulfate resisting cement shows bad to corrosion resistance.

• Journal of the korean academy of Pediatric Dentistry
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• v.30 no.1
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• pp.41-46
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• 2003

In order to evaluate the sufficient etching time for successful bonding and also minimizing unnecessary mineral loss, the enamel surface roughness analysis was performed using confocal laser scanning microscopy. Sixty extracted sound human molar teeth were imbedded in the center of acrylic cylinder using self-curing clear resin exposing buccal surface, and then polished with series of SiC paper(220, 500, 800, 1000, 2000, 4000 grit). Each specimen was randomly assigned to six groups(N=10). 37% phosphoric acid was applied to the polished tooth surface for 10, 20, 30, 40, 50, 60 seconds respectively and washed with copious water. After the surface roughness analysis, five roughness parameters(Sa, Sq, Sz, Sdr, Ra) were statistically analysed by ANOVA and Duncan post hoc test. We found that the all five parameters had higher roughness value in 30 seconds etching time, especially parameter Sz showed the lowest value in 10 seconds etching time and the highest value in 30 seconds etching time compared with the other etching times(p<0.05).

• Environmental Mutagens and Carcinogens
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• v.15 no.2
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• pp.115-121
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• 1995

Bacterial mutagenicity of shellfish or canned products of red-muscle fish affected by hot-airdry processings and/or during storages was investigated by Ames preincubation method. Mussel (Mytilus edulis) and surf clam (Tapes japonica) dried under either 40$\circ$C, 50$\circ$C or 60$\circ$C until remained about 25 % water content was stored at 4$\circ$C or 25$\circ$C for 6 months. Commercially available canned product of pacific saury (Cololabis saira) and mackerel saury (Scotnberjaponicus), whose producer or date of manufacture was identical each other, was stored at 25$\circ$C for 6 months. Mutagenic substances from sample (25 g dry weight) were extracted and purified for mutagenicity assay against S. typhitnurium TA98 by the simultaneous distillation extraction (SDE) method (Lee et al. 1955). Mutagenicity of sample was expressed number of revertant per 25 g dry sample. Number of revertant from unheated mussel sample was appeared to be 135, relative to 22 from unheated surf clam sample. Mutagenicity of both shellfish was strongly affected by heat treatment, but a lesser extent by storage conditions, even at 25$\circ$C for 6 months. Revertants of the mussel sample dried at 40$\circ$C, 50$\circ$C, or 60$\circ$C was found to be 227, 779, and 883, respectively. Similar, but lower, mutagenicity was observed from the sample of surf clam dried at 40$\circ$C, 50$\circ$C, or 60$\circ$C than mussel. Mutagenicity of canned pacific saury and mackerel samples was not influenced by storage conditions. Number of revertant from pacific saury was 175 which was relatively higher than 5 from mackerel. Mutagenicity of fresh pacific saury and mackerel samples was significantly higher than that of their counterparts from canned products. These results indicate that mutagenicity of the shellfish was affected by heat treatment (40$\circ$C, 50$\circ$C, or 60$\circ$C) used for drying process, but not much by storage for 6 months at 4$\circ$C or 25$\circ$C and the mutagenicity of canned products of red-muscle fish was not influenced by storage, even at 25$\circ$C for 6 months.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.7 no.3
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• pp.229-240
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• 1987

Carbonation of concrete is one type of a chemical process. The reaction mechanism is very complex for the case when low-calcium fly ash and blast furnace slag is added. When fly ash and blast furnace slag is used as an admixture in concrete, they improve compressive strength in the long term, permeability and chemical resistance of concrete by a pozzolanic reaction and latent hydraulic property. On the other hand, the pozzolanic reaction of fly ash and latent hydraulic property of the blast furance slag leads to a reduction of the alkalinity of the concrete. It has been pointed out that this will accelerate the carbonation of the concrete and the corrosion of reinforcement steel embedded in the concrete. In order to clarify the effect of fly ash and blast furance slag on the carbonation of concrete, an accelerated carbonation testing of concrete was carried out by varying the conditions of concrete and the initial curing period in water. The test results of accelerated carbonation were compared to the carbonation test results of concrete stored for 15 years in open air, but protected from rain. As a result, the equation for the rate of carbonation based on compressive strength of concrete was proposed.