• Transactions of the Korean Society of Mechanical Engineers B
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• v.25 no.2
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• pp.225-234
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• 2001

This paper represents the vector fields, three dimensional mean velocities, the turbulent intensities, the turbulent kinetic energy, and the Reynolds shear stresses in the X-Y plane of gas swirl burner with a cone type baffle plate measured by using X-probe from hot-wire anemometer system. This experiment is carried out at flow rates 350 and 450ℓ/min respectively, which are equivalent to the combustion air flow rate necessary for heat release 15,000 kcal/hr in gas furnace, in the test section of subsonic wind tunnel. The vector plot shows that the maximum axial mean velocity component exists in the narrow slits situated radially on the edge of gas swirl burner, for that reason, there is some entrainment phenomena of ambient air in the outer region of burner. Moreover, mean velocities in the initial region are largely distributed near the outer region of burner at Y/R≒0.97, but they diffuse and develop into the center flow region of burner according to the increase of axial distance. The turbulent intensities and the turbulent kinetic energy due to large inclination of mean velocity and swirl effect show that the maximum value in the initial region of burner is formed in the narrow slits situated radially on the edge of gas swirl burner and large values are mainly formed in the entire region of burner after X/R=2.4358, hence, the combustion reaction is anticipated to occur actively near this region. And the Reynolds shear stresses are also largely distributed from slite to vanes of gas swirl burner in the intial region, but their values largely disappear after X/R=3.2052.

• Journal of Energy Engineering
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• v.23 no.2
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• pp.1-6
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• 2014

Upgrading technology has been studied for efficient utilization of low rank coal. Spray coating of heavy oil was applied on the upgrading process in order to stabilize low rank coal against spontaneous combustion. Low rank coal, which contains more than 30wt% of moisture, was upgraded to high calorific coal and stabilized by spray coating of heavy oil. It was identified that spray coating of heavy oil after drying coal is the optimum procedure of upgrading low rank coal. The experimental results show that more than 2wt% of heavy oil should be adsorbed on the coal in order to stabilize sufficiently for spontaneous combustion.

• Korean Journal of Community Nutrition
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• v.17 no.1
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• pp.101-108
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• 2012

The purpose of this survey is to investigate the nutritional status and dietary intake of gastrectomized cancer patients in Asan Medical Center. The subjects were 98 patients, who underwent a gastrectomy due to gastric cancer and were admitted to the General Surgery Department during March 2007 to December 2007. We examined general characteristics (sex, age, clinicopathological stage, type of operation), anthropometric data (height, weight change), biochemical data (red blood cell RBC, hemoglobin HGB, hematocrit HCT, mean corpuscular volume MCV, total lymphocyte count TLC, albumin, total cholesterol), dietary intake and dietary intake related symptoms. Weight loss of gastrectomized patients was $9.0{\pm}4.3$% from preillness weight to visiting out-patient department (OPD) weight. Biochemical data (RBC, HGB, HCT, MCV, TLC, albumin, total cholesterol) significantly deteriorated after gastrectomy. However, outpatient visits were all restored to the normal range. Postoperative energy intake was $785.0{\pm}164.2$ kcal, which corresponds to $41.6{\pm}9.6$% of daily energy requirement. The cause of poor oral intake is mostly fear, abdominal pain and abdominal discomfort. Therefore, to control pre-or post-operative weight change in the future requires, focusing on the body weight to maintain a normal or usual nutrition by interventions and increased caloric intake during hospitalization for the development of nutrient-dense meals. In addition, as the main reason of the lack of intake of meals after the gastrectomy was fear, the patients should be actively encouraged to consider the importance of eating proper meals.

• Korean Journal of Community Nutrition
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• v.17 no.1
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• pp.14-25
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• 2012

The purpose of this study was to estimate the daily intake of vitamin A in Korean female university students. Vitamin A intake was estimated using an inconsecutive 3-day dietary intake survey from 481 young women. Vitamin A intake values were calculated based on the data in USDA database. Average age, height, and weight of the subjects were 20.05 years, 162.13 cm and 54.38 kg, respectively. The subject's average intake of energy was 1645.67 kcal. The mean vitamin A, retinol and ${\beta}$ carotene intakes were $908.35{\pm}863.18$ ug retinol equivalent/day, $199.19{\pm}166.00$ ug/day and $3872.59{\pm}4972.17$ ug/day, respectively. The 21.83% of the subjects consumed less than the Estimated Average Requirement (EAR) for vitamin A. And subjects consumed 141.69% of the Recommended Nutrient Intake (RNI) for vitamin A. Food groups consumed with high vitamin A content in our subjects included vegetables (423.96 ug RE/day), potato and starches (213.64 ug RE/day), cereals (62.60 ug RE/day), eggs (55.17 ug RE/day) and milks (53.45 ug RE/day). The major food sources of vitamin A were sweet potato, carrot, spinach, egg, and cereal, and the top 30 foods provided 89.57% of total vitamin A. Also animal-derived food provided 9.65% of the vitamin A intake from the top 30 foods. In conclusion, judging from RNI, the vitamin A intake of the Korean female university students in this study was generally adequate. The result of our study may be used as a basis for follow-up studies of vitamin A intake like assessment of vitamin A nutritional status or evaluation of carotenoid food sources in Korean young women.

• Korean Journal of Community Nutrition
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• v.17 no.1
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• pp.69-80
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• 2012

This study was conducted to examine the nutritional status, quality of diet and quality of life in postmenopausal women with mild climacteric symptoms based on their food group intake patterns. The data for nutritional status were obtained using 3-day records. Quality of diet was assessed by INQ, NAR, MAR, DDS, DVS, DQI-I. Climacteric symptoms were analyzed by the questionnaire of Kupperman's index and MENoL. The subjects were classified into the five groups, GMVDF, GMVdF, GMVDf, GMVdf, GmVDF according to their food group intake patterns. Analysis of nutrient intakes showed that the GMVDF group took significantly higher levels of kcal, carbohydrate, protein, fat, vitamin A, thiamin, riboflavin, folate, vitamin C, vitamin E, calcium, phosphorous, sodium, iron, zinc and fiber than GMVdf group did (p < 0.05). INQ of Ca and Fe appeared to be higher in GMVDF than in GMVdf groups (p < 0.05). Analysis of NARs showed that missing milk groups took lower riboflavin, Ca and P than other groups did as the same result with MAR (p < 0.05). Analysis of DDS and DQI showed that GMVdf group had the lowest quality of diet (p < 0.05); however, no difference was found on DVS. The GMVdf group showed the worst climacteric symptoms compared with those of the other groups (p < 0.05). However, we couldn't observe any differences in menopause-specific quality of life among the groups. In conclusion, it would be beneficial to meet all five food groups to increase the quality of diet and to reduce the climacteric symptoms in postmenopausal women.

• Textile Coloration and Finishing
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• v.8 no.3
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• pp.36-51
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• 1996

In order to investigate the degradation behavior of PET fabrics, sodium diethylene glycolate (SDEG)-diethylene glycol (DEG) solutions were prepared and PET fabrics were treated in the solution. The dissolution rate constant and apparent activation energy of the PET fabrics were calculated by Eyring's and Arrhenius's equation respectively and measured dyeing properties, moisture and antistatic properties. Then compared SDEG-treated fabrics with NaOH-treated. The results were as follows; 1. PET fabrics decreased their weight in SDEG-DEG solution, and the decreasing rate showed a linear relationship to the treating time at constant temperature and concentration of SDEG-DEG solution. 2. The dissolution rate constant showed a linear relationship to the concentration of SDEGDEG solution and an exponential relationship to treating temperature. 3. Apparent activation energy of dissolution was 23.45 kcal/mol. 4. The K/S values and the ΔL values of fabrics treated with SDEG-DEG solution are higher and lower respectively than fabrics treated with NaOH. 5. SDEG-DEG solution treatment improved fabric's moisture regain and it reached almost maximum at about 40% weight loss. 6. In the both reagent the light, wet and sublimation fastness of fabrics are similar. 7. SDEG-DEG solution gave more electrical discharge effect to the fabrics than that of NaOH. 8. NaOH treated PET microfiber have crater-like surface, while SDEG-DEG solution give bathochromic effect to the PET microfiber because which has wrinkles on the surface.

• Journal of Microbiology and Biotechnology
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• v.26 no.6
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• pp.1067-1076
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• 2016

The gene encoding lipase (Lip98) from Aeromicrobium sp. SCSIO 25071 was cloned and functionally expressed in Escherichia coli. Lip98 amino acid sequence shares the highest (49%) identity to Rhodococcus jostii RHA1 lipase and contains a novel motif (GHSEG), which is different from other clusters in the lipase superfamily. The recombinant lipase was purified to homogeneity with Ni-NTA affinity chromatography. Lip98 showed an apparent molecular mass of 30 kDa on SDS gel. The optimal temperature and pH value for enzymatic activity were recorded at 30℃ and 7.5, respectively. Lip98 exhibited high activity at low temperatures with 35% maximum activity at 0℃ and good stability at temperatures below 35℃. Its calculated activation energy was 4.12 kcal/mol at the low temperature range of 15-30℃. Its activity was slightly affected by some metal ions such as K⁺, Ca²⁺, and Na⁺. The activity of Lip98 was increased by various organic solvents such as DMSO, ethanol, acetone, and hexane with the concentration of 30% (v/v) and retained more than 30% residual activity in neat organic solvent. The unique characteristics of Lip98 imply that it is a promising candidate for industrial application as a nonaqueous biocatalyst and food additive.

• Journal of Korean Society of Environmental Engineers
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• v.34 no.9
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• pp.583-589
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• 2012

The various promotion countermeasures such as solidification, carbonization, and the creation of cement materials have been considered to existing treatment methods such as incineration and the creation of composts, since direct landfill was prohibited for encouraging the recycling based on the sludge treatment on land. The Main objective of this study is to investigate the feasibility of co-incineration for MSW (Municipal Solid Waste) and SS (Sewage Sludge) through the change of heat and atmospheric pollutants. In this study, LHV (Low Heating Value) is 100~300 kcal/kg because the MC (Moisture Content) of de-hydrated sewage sludge is approximately 80%. From the results, we knew the feasibility of co-incineration for MSW (80%) and SS (20%). As the co-incineration rate of SS up to 20% became higher, the loading of heat and atmospheric pollutants was not influenced.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2002.02a
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• pp.151-157
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• 2002

화석에너지에 대한 경제적 부담과 환경오염문제를 줄이기 위하여 열펌프의 성능계수향상을 위하여 냉온 공기열교환기(HEEVA)를 고안하였고, 이 열교환기의 열특성과 성능계수향상에 미치는 영향을 분석하기 위하여 냉.난방 실험을 수행하였다. HEEVA에 의한 찬 공기와 더운 공기의 온도변화, 전열량 및 냉온 공기열교환기 효율, 총열전달계수등을 측정분석하였고, 냉난방시 외기온에 따른 열펌프의 성능계수, 소비전력, 응축기.증발기 출구 공기토출 온도 변화를 측정 분석함으로서 다음과 같은 결과를 얻을 수 있었다. 1. 외기온이 -4~11$^{\circ}C$로 변할 때 열펌프의 난방과정에서 HEEVA 찬공기 입출구 온도차는 4.5$^{\circ}C$에서 9.$0^{\circ}C$로 증가하였으며, HEEVA에 의한 영향으로 2~6$^{\circ}C$상승된 공기가 증발기 입구로 유입되어 냉매증발을 촉진하였다. 2. 실온이 4~22$^{\circ}C$일 때 HEEVA 더운공기 입출구 온도차는 3$^{\circ}C$에서 7$^{\circ}C$로 증가하였으며, 응축기에 유입되는 공기온도를 3~8$^{\circ}C$낮게 함으로서 압축기 소모전력을 감소시켜 COP 상승 효과를 나타냈다. 3. 외기온과 실온변화에 따라 풍량 346m$^3$/hr의 찬 공기가 받은 열량과 풍량 747m$^3$/hr의 더운 공기가 준 열량간의 차는 50~150kcal/hr로 나타났으며, 더운 공기가 준열량과 찬 공기가 받은 열량의 비가 83~98% 이었으므로 HEEVA의 열 교환율은 91% 을 보였다. 4. 총합열전달계수는 이론값이 실험 값보다 1~3W/m$^2$K 크게 나타났으며, 이 결과는 두 값 사이에 10% 내.외의 편차로서 Nusselt수를 구하기 위한 Petukhov상관식의 자체오차 15%에 비해 크지 않은 오차범주에 속하며, 이론상의 총합열전달계수 유도식의 타당성을 입증한 것이라 하겠다. 5. HEEVA를 작동함으로서 난방시 COP가 HEEVA를 작동하지 않았을 경우보다 0.3~0.5 향상된 것으로 나타났다. 이것은 HEEVA가 겨울철 난방에 효율을 높일수 있는 것으로 판단된다.

• Transactions of the Korean Society of Automotive Engineers
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• v.15 no.1
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• pp.23-28
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• 2007

This study aims to find out cooling characteristics of TMA(Tri-Methyl-Amine, $(CH_3)_3N$) 25wt%-water clathrate compound with ethanol($CH_3CH_2OH$) such as supercooling, phase change temperature and specific heat. For this purpose, ethanol is added as per weight concentration and cooling experiment is performed at $-6{\sim}-8^{\circ}C$, cooling heat source temperature, and it leads the following result. (1) Phase change temperature is decreased due to freezing point depression phenomenon. Especially, it is minimized as $3.8^{\circ}C$ according to cooling source temperature in case that 0.5wt% of ethanol is added. (2) If 0.5wt% of ethanol is added, average supercooling degree is $0.9^{\circ}C$ and minimum supercooling is 0.8, $0.7^{\circ}C$ according to cooling heat source temperature. The restraint effect of supercooling is shown. (3) Specific heat shows tendency to decrease if ethanol is added. It is $3.013{\sim}3.048\;kcal/kg^{\circ}C$ according to cooling heat source temperature if 0.5wt% of ethanol is added. Phase change temperature higher than that of water and inhibitory effect against supercooling can be confirmed through experimental study on cooling characteristics of TMA 25wt%-water clathrate compound by adding additive, ethanol. This can lead to shorten refrigerator operation time of low temperature latent heat storage system and improve COP of refrigerator and efficiency of overall system. Therefore energy can be saved and efficiency can be improved much more.