• Journal of the Korean Geotechnical Society
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• v.19 no.2
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• pp.65-74
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• 2003

Most of land reclamation projects are being implemented along the south and west coastal lines of the Korean Peninsula. The earth structures and in-ground LNG tank, and buildings can be constructed using artificial freezing method on the reclaimed land to control the uplift pressure caused by capillary forces. In this study, upon freezing a saturated soil in a closed-system from the top, a considerable frost heaving pressure was developed. Decomposed granite soils, silty soil, and sandy soil were used in the laboratory freeze test which is sometimes subjected to thermal gradients under closed-systems. A major concern has been the ability to predict the frost heaving pressure over the results of relatively short-term laboratory tests. The frost heaving pressure arising within the soil samples and the temperature of the samples inside were monitored with time elapse. The degree of saturation versus heaving pressure curve is presented for each soil sample and the maximum pressure is closely related to this curve. TDR apparatus was used to measure the volumetric water content by the measurement of unfrozen water contents of frozen soils. Unfrozen water increased in soils containing a high percentage of fine-grained particles. In fine-grained soils with strong attractive farces between soil grains and water molecules, additional water is attracted into the pores leading to further volume changes and ice segregation.

• Korean Journal of Clinical Pharmacy
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• v.12 no.1
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• pp.22-28
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• 2002

Aceclofenac, 2-[(2',6'-dichlorphenyl)amino]phenylacetoxiacetic acid, is a new nonsteroidal anti-inflammatory drug that belongs to the family of phenylacetic acids. It shows good tolerance and potent analgesic/antiinflammatory properties, and acts on cartilaginous chondriocytes, stimulating their repair mechanism. The purpose of the present study was to evaluate the bioequivalence of two aceclofenac products, $Airtal^{TM}$ tablet (Daewoong Pharmaceutical Co.) and $Acer^{TM}$ capsule (Kyungdong Pharmaceutical Co.), according to the guideliner of Korea Food and Drug Administration (KFDA). The aceclofenac release from the two aceclofenac products in vitro was tested using KP VII Apparatus II method at pH 7.8 dissolution media. Sixteen normal male volunteers, $23.13\pm2.03$ years in age and $66.33\pm7.08$ kg in body weight, were divided into two groups and a randomized $2\times2$ cross-over study was employed. After one tablet or capsule containing 100 mg of aceclofenac was orally administered, blood was taken at predetermined time intervals and the concentrations of aceclofenac in serum were determined using HPLC with UV detector. The dissolution profiles of the two aceclofenac products were very similar at pH 7.8 dissolution media. The pharmacokinetic parameters such as $AUC_t,\;C_{max}\;and\;T_max$ were calculated and ANOVA test was utilized for the statistical analysis of the parameters. The results showed that the differences in $AUC_t,\;C_{max}\;and\;T_{max}$ between two products were $6.50\%,\;-1.06\%\;and\;11.96\%$ respectively, when calculated against the $Airtal^{TM}$ tablet. The powers $(1-\beta)\;for\;AUC_t,\;C_{max}\;were\;89.82\%\;and\;82.84\%$, respectively. Minimum detectable differences $(\Delta)\;at\;\alpha=0.05\;and\;1-\beta=0.8$ were less than $20\%\;(e.g.,\;17.51\%\;and\;19.30\%\;for\;AUC_t,\;C_{max}$, ). The $90\%$ confidence intervals were within $\pm20\%\;(e.g.,\;-3.73\%\sim16.73\%\;and\;-12.34\%\sim10.22\%\;for\;AUC_t,\;C_{max},\;respectively)$. Two parameters met the criteria of KFDA for bioequivalence, indicating that $Acer^{TM}$ capsule is bioequivalent to $Airtal^{TM}$ tablet.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.6
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• pp.892-898
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• 2005

The effect of gamma irradiation on volatile components of Korean dried ginger (Zingiber officinale Roscoe) was studied and compared with non-irradiated sample. Volatile compounds from non- and irradiated samples were extracted using simultaneous distillation-extraction (SDE) apparatus and analyzed by gas chromatography-mass spectrometer (GC/MS). A total of 83 and 71 compounds were identified and quantified from non-and irradiated dried ginger at dose of 10 kGy. Identified components were hydrocarbons, alcohols, aldehydes, esters, ketones and miscellaneous compounds. The terpenoid compounds in volatile flavor compounds identified from non and irradiatied dried ginger were $98.27\%\;and\;98.12\%$, respectively. $\alpha$ -zingiberene,$\beta$-sesquiphelland reno, geranial, (Z,E) $\alpha$ -farnesene, $\beta$ -phellandene were detected as major volatile compounds of two experimental sample. The amount of volatile components in the samples was changed by irradiation but the profile of volatiles in non- and irradiated dried ginger were the same.

• Korean Chemical Engineering Research
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• v.44 no.6
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• pp.669-675
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• 2006

Toluene of aromatic compounds, MEK of ketones and IPA of alcohols were extremely used as VOCs (Volatile Organic Compounds) on the getting into step with industrial process. The adsorption characteristics of three component solvent vapors (Toluene-MEK-IPA) on the activated carbonaceous adsorbents such as AC, ACF and AC+ACF were investigated in a stainless steel fixed bed adsorption experimental apparatus in order to identify those carbons for eliminating and recovering solvent vapors from industrial emission sources. The used activated carbonaceous adsorbents were pelletized commercial activated carbon and activated carbon fiber. The breakthrough curves and adsorption capacity have been obtained at atmospheric pressure in a adsorption fixed bed. It has been found that non-polar and larger molecules have been adsorbed better than polar and smaller molecules. Especially, alcohols and ketones were poorly adsorbed due to competitive adsorbability in ternary mixture system. However, it could be overcome by employment of activated carbonaceous adsorbent which have different porosity distribution appropriately.

• Journal of Environmental Health Sciences
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• v.6 no.1
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• pp.47-52
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• 1979

Up to the present there were the blood transfusion and the use of apparatus not to sterilize at surgical operation and medical treatments in well known infectious ways of hepatitis B virus. But all its ways were still not surely known. As the other ways of hepatitis B virus infection, it was suggested that contagion such as kissing, sexual contact, homosexuality, and varieties discharged out human body urine, stool, tear, salivary, menstrual blood, Vaginal discharge etc, and low economic status, unsanitary environmental life, alcohol and smoking related to hepatitis B virus infection. From 800 waitress who frequently contact with a lot of drinker with low economic status and unclear environmental life, this study were investigated HBs Ag (Hepatitis B surface antigen) known marker for hepatitis B virus infection in their serum, and a few conditions of their private life in order to known dangerous rate b~ing exposed to the source of hepatitis B virus infection as comparison with control group. The results were summarlized as following 1. The positive rate of HBs Ag (4.3%) was significantly higher in waitress than in control group(1.1%). 2. In waitress old, 20-24 ages group was the most as 59.5%, and positive rate of HBs Ag was trend of higher in twenties than thirties. 3. Among the waitress, one that it was less than a year were the most (62.4%) in the period to work at restaurant business, and positive rate of HBs Ag was trend of higher in propotion to period to work at there. 4. Among the waitress, one who entertained to beer hall was the most (46%), and they were trend of higher in positive rate of HBs Ag (6.3%) than other waitress. 5. Among the waitress, one to drink with smoking, and only to drink, and only to smoke, and not to drink and smoke 66.1%, 21.5%, 4.6% and 7.8%. Espically in one to drink with smoking, ther was trend of indicating the high positve rate of HBs Ag, and it was made suspicion of the relationship of alcohol smoking, contact with a lot of drinker, unclear environment to hepatitis B virus infection. In the above results, it was found that dangerous rate being exposed in hepatitis B virus infection was high in the waitress. Therefore there are required for active preventions against hepatitis B virus infection them. Also as it is possible to be infectious source in public health that waitress infected to viral hepatitis, it is thought that appropriate rules about them.

• Journal of Environmental Health Sciences
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• v.3 no.1
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• pp.27-44
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• 1976

This study was carried out to evaluate the harmful factors in working environments and to investigate the labor productivity after improvement of environments, surveying 93 industrial establishments of 10 industries located in Youngdeungpo industrial area in Seoul. The results obtained were as follows: 1) The highest noise level of 125dB(A) was indicated at the rolling process of transport equipment manufacturing industry. 2) The best illumination level was shown in precise machinery industry and the worst was indicated in rubber products, metallic products and transport equipment manufacturing industries. 3) Thermal conditions were above threshold limit value (TLV) at more than two processes of all industries except printing industry. 4) The highest dust concentration was determined in textile and wearing manufacturing industry. 5) Organic solvents were detected at 52 processes in 93 industrial establishments and 33 processes of them showed higher than TLV. The results about harmful chemicals were as follows: a) sulfur dioxide ($SO_2$)was determined higher than TLV on welding process of metallic product manufacturing industry and heat treatment process of transport equipment manufacturing industry. b) Carbon monoxide (CO) concentration was 700ppm at heat treatment process of transport equipment manufacturing industry, indicating 14 times of TLV. c) vinylchloride concentration in the air of PVC raw material mixing process and PVC preparation process of chemical product manufacturing industry was determined higher than TLV. d) Hydrochloride (HCl) concentration in the air of wire expanding process of transport equipment manufacturing industry was determined higher than TLV. 7) Higher values of lead concentration than TLV were determined at lead welding metallic product manufacturing industry and type planting process of process of printing industry, $1.8mg/m^3$ and $0.3mg/m^3$ respectively. 9) 22, 968 of 52, 855 workers (i.e. 43.5%) in 93 industries were exposed to various harmful agents. 10) It was found that the improvement of illumination in electric apparatus manufacturing industry (from 20~40 lux to 420 lux) resulted in an increase in productivity of 6.5% per capita and a decrease in faulty products of 19%. 11) Improvement of environments using local exhaust ventilation system resulted in a decrease of harmful substances lower than TLV and an increase in productivity of 11.4%. 12) Improvement of shovelling tools based on ergonomics resulted in a reduction in energy expenditure of 25.3% and an increase in productivity of 32.2% per capita.

• Journal of Environmental Health Sciences
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• v.39 no.1
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• pp.83-89
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• 2013

Objectives: The purpose of this experiment was to illuminate the relationship between the phosphorus removal rate of unit operation and the phosphorus removal rate of phosphorus volume loading in the Ferrous Nutrient Removal process, which consists of an anoxic basin, oxic basin, and iron precipitation apparatus. Methods: This study was conducted in order to improve the effect of nitrogen and phosphorus removal in domestic wastewater using the FNR (Ferrous Nutrient Removal) process which features an iron precipitation reactor in anoxic and oxic basins. The average concentration of TN and TP was analyzed in a pilot plant ($50m^3/day$). Results: The removal rate of T-N and T-P were 66.5% and 92.8%, respectively. The $NH_3-N$ concentration of effluent was 2.62 mg/l with nitrification in the oxic basin even though the influent was 17.7 mg/l. The $NO_3$-N concentration of effluent was 5.83 mg/l through nitrification in oxic basin even though the influent and anoxic basin were 0.82 mg/l and 1.00 mg/l, respectively. The specific nitrification of the oxic basin ($mg.NH_3$-Nremoved/gMLVSSd) was 16.5 and specific de-nitrification ($mg.NO_3$-Nremoved/gMLVSSd) was 90.8. The T-P removal rate was higher in the oxic basin as T-P of influent was consumed at a rate of 56.3% in the anoxic basin but at 90.3% in the oxic basin. The TP removal rate (mg.TP/g.MLSS.d) ranged from 2.01 to 4.67 (3.06) as the volume loading of T-P was increased, Conclusions: The test results showed that the electrolysis of iron is an effective method of phosphorus removal. Regardless of the temperature and organic matter content of the influent, the quality of phosphorus in the treated water was both relatively stable and high due to the high removal efficiency. Nitrogen removal efficiency was 66.5% because organic matter from the influent serves as a carbon source in the anoxic basin.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.41 no.8
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• pp.511-519
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• 2017

In this study, we have performed tests to improve the productivity of hybrid solar stills, which can be operated by solar thermal energy and/or waste heat of exhaust gas from electrical generators. The experimental apparatus is a hybrid solar still with a $1m{\times}2m$ collecting area, which consists of a conventional simple solar still and a vertical multi-effect diffusion(MED) section. The experiments were conducted under various operating conditions, with two identical hybrid solar stills, using solar radiation as the energy source. The results of the tests showed that the yield of the hybrid solar still depends on the various operating conditions. Insulation at the side glasses and a lower basin seawater level increased the productivity of the hybrid solar still. Reflecting fins with less than 47% reflectivity unexpectedly decreased the total productivity. However, the various feeding flow rate of the seawater into MED part did not show clear effects on productivity in the tested range.

• Korean Journal of Food Science and Technology
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• v.29 no.6
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• pp.1222-1227
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• 1997

Effects of the physical properties of solvent system such as pH and polarity change by salt addition in solvent system were investigated by using high speed countercurrent chromatography apparatus (Model CCC-1000, Pharm-Tech Research Corp. USA). The changes of pH and interfacial tension in solvent system of high speed countercurrent chromatography did not significantly affect on retention of stationary phase, but induced remarkable changes in the partition coefficient of ginkgo flavonoids, kaempferol, quercetin and isorhamnetin. The partition coefficients of ginkgo flavonoid standard increase with an increased pH of solvent system and quercetin sharply increased at pH 10.0. Retention of stationary phase decreases with an increased concentration of KCl in butanol of solvent system. Interfacial tension between two phase in solvent system of hexane increases with an increased concentration of KCl. The polarity of solvent system significantly changes the partition coefficients of ginkgo flavonoid.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2005.10a
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• pp.189-194
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• 2005

The interest of people is rising on water leisure and the population of water sports is increasing with expanded nationwide roads and 5-day work system for income elevation. However, there are many discussions about the way to prevent the accident related to water leisure activities. Water Leisure Safety Regulation was enacted in 1999 as a part of the way and revised in 2005. Therefore it needs to grasp the present state of water leisure activities and analyze the actual condition of consciousness. For the analysis. the question survey was conducted on water leisurers in the focus with regulation of the revised so that the degree of relevance and correlation between mutual variables were analyzed by Frequency and Crosstabs. From this study we found that more than $60\%$ of water leisurers thought registration, safety instruction, insurance, and safety inspection necessary and there was a characteristic common inclination to all for necessity to impose legal controls on water leisure activities as the level of dissatisfaction for water leisure apparatus and cognition for necessity of insurance was high.