• 한국지하수토양환경학회지:지하수토양환경
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• 제26권5호
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• pp.9-19
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• 2021

This study evaluated the feasibility of combined use of physical separation and soil washing to remediate heavy metals (Pb and Cu) contaminated soil in a military shooting range. The soils were classified into two types based on the level of heavy metal concentrations: a higher contaminated soil (HCS) with Pb and Cu concentrations of 6,243 mg/kg and 407 mg/kg, respectively, and a lower contaminated soil (LCS) with their concentrations of 1,658 mg/kg and 232 mg/kg. Pb level in both soils exceeded the regulatory limit (700 mg/kg), and its concentration generally increased with decreasing soil particle size. However, in some cases, Pb concentrations increased with increasing soil particle size, presumably due to the presence of residues of bullets in the soil matrix. As a pretreatment step, a shaking table was used for physical separation of soil to remove bullet residues while fractionating the contaminated soils into different sizes. The most effective separation and fractionation were achieved at vibration velocity of 296 rpm/min, the table slope of 7.0°, and the separating water flow rate of 23 L/min. The efficiency of ensuing soil washing process for LCS was maximized by using 0.5% HCl with the soil:washing solution mixing ratio of 1:3 for 1 hr treatment. On the contrary, HCS was most effectively remediated by using 1.0% HCl with the same soil:solution mixing ratio for 3 hr. This work demonstrated that the combined use of physical separation and soil washing could be a viable option to remediate soils highly contaminated with heavy metals.

• 한국의류학회지
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• 제23권1호
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• pp.66-77
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• 1999

For this study It was measured the seam puckering based on the mechanical properties of tencel under the proper condition of needlework and machine sewing analyzed the mechanical properties which re influenced to the seam puckering and estimated the seam puckering based on the mechanical properties. The results of this study are as follows : There are three types of the seam puckering for each step which is caused by repeated washing and press. Concerning the seam puckering with the number of washing the more the number of washing is increased the less the seam puckering is decreased. Concerning the mecanical properties of the sample with the seam puckering. The seam puckering is related to LT positively B, 2HB, T, W negatively Among the mechanical properties LT, B, 2HB, T, W are most influenced to the seam puckering. Judging from the result of estimating seam puckering based on mechanical properties the estimate-formula is satisfied in this study.

• 한국지하수토양환경학회지:지하수토양환경
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• 제10권1호
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• pp.58-64
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• 2005

본 연구는 플럭 형성 비소 오염토양에 대한 토양세척기법 적용시 최적의 운전조건을 도출하고자 하였으며, 대상 시료는 D 폐철광산 토양을 선정하였다. 최적의 cut-off size는 전체 토양 중량에 대하여 약 $94\%$ 정도의 분포를 보이는 0.15 mm ($\#100$체)이었다. 수산화나트륨과 염산 모두 비소 제거에 효과적이었고, 진탕비 (토양[g]:세척용액[mL])는 2가지 세척제에 대하여 1:5가 최적 조건임을 알 수 있었다. 토양세척시 형성되는 플럭에 대하여 비소 농도를 파악한 결과, 여타 pH조건에서보다 pH $5\~6$에서 형성된 플럭의 건조 비소 농도가 $990\~1,086\;mg/kg$ dry solids로 높음을 알 수 있었다. 따라서, 세척효율의 향상 여부를 파악하기 위하여 토양세척시 형성되는 플럭의 제거 유무에 따른 연속 토양세척 실험을 수행하였다. 0.2 M염산을 사용하여 플럭을 제거한 토양을 염산 1 M로 세척한 다음 1 M 수산화나트륨으로 연속 세척한 결과, 비소 농도는 약 1.5 mg/kg dry soil을 보였다. 각 단계마다 발생된 세척유출수기 비소 농도는 약 $2\~3\;mg/L$이었으나, 각각의 세척유출수를 혼합하는 경우 비소 농도가 $50\;{\mu}g/L$ 이하로 감소되었는제 이는 비소가 응집${\cdot}$침전으로 제거되는데 유리한 pH조건으로 변환되기 때문인 것으로 판단된다.

• 대한영양사협회학술지
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• 제12권2호
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• pp.157-171
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• 2006

This study was intended to suggest HACCP-based standard recipe for bellflower roots, classified as no thermal cooking process, served in a university foodservice operation. The time-temperature and microbial contamination level in each cooking step were analyzed. The temperatures of bellflower root, peeled garlic and green onion at receiving were at 13.8$\pm$2.8, 12.6$\pm$2.9 and 13.7$\pm$$0.8^\circC$ respectively, which were above the temperature limit. The time consumed for pre-preparation was up to 90 min at room temperature having high microbial growth potential. The levels of total plate counts (TPC) of bellflower root and garlic were over the limit of $10^6$ CFU/g as were the numbers of coliforms in bellflower roots. There were no microbial reductions in pre-preparation and cooking, which resulted in over $10^5$- $10^6$ CFU/g of TPC at service step. Two CCPs identified were washing/sanitation at pre-preparation and service steps. The control measures were washing/sanitation and temperature control. It was verified that CCPs for no cooking process developed in preceding studies were applicable for the microbiological food safety of this menu item. The HACCP-based standard recipe was developed to produce a quantity for 100 servings by observing the critical limits established for CCPs. These results suggest that the selection of proper provider is imperative to control the microbial contamination of raw materials at purchasing step. Also, the sanitary education program should be developed for the employees to understand and comply the HACCP plan and standard recipe.

• The Korean Journal of Ceramics
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• 제1권1호
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• pp.35-39
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• 1995

Yttrium aluminum garnet(YAG) powders were synthesized by spray-drying of the hydroxides coprecipitated from a mixture of aqueous solutions of $Al(NO_3)_3.9H_2O \;and\; Y(NO_3)_3.6H_2O$ Phase formation in the powders during heat treatments and their sintering charactristics were investigated. In the powder obtained by washing the hydroxides before spray-drying, a metastable yttrium aluminum hexagonal (YAH) phase was first crystallized and then transformed into YAG as temperature was increased. The formation of YAH was attributed to a deviation in compositions of the particles from the starting composition of YAG. However, the powder prepared without washing step contained a stable yttrium aluminum monoclinic(YAM) phase in addition to YAG due to a large deviation from the starting composition. A powder compact of a single phase YAG was pressureless-sintered for 4 hrs at $1700^{\circ}C$ and the density was 93% of the theoretical density.

• 한국의류학회지
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• 제26권10호
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• pp.1401-1411
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• 2002

To Save energy and cost one bath/one step dyeing and finishing on cotton/polyester blends is carried out with disperse dyes in the presence of crosslinking agent. Cotton 100 %, cotton/polyester 70/30, 50/50, 35/65, polyester 100 % fabrics were used. wrinkle recovery angle, tensile strength retention and tearing strength retention were determined in according to the dyebath composition, and also determined while the concentration of DMDHEU, molecular weight and concentration of PEG were varied. Colorfastness to abrasion, washing and light were tested. For cotton and cotton/polyester blends dyed in the presence of DMDHEU/PEG, wrinkle recovery was improved. Tensile strength retention and tearing strength retention were decreased, in compared with dyed fabrics without DMDHEU. Colorfastness to abrasion was good but colorfastness to washing and to light were poor for the fabrics dyed in the presence of DMDHEU/PEG.

• 한국산학기술학회논문지
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• 제3권4호
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• pp.295-302
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• 2002

본 연구는 천연계 계면활성제의 하나인 사이클로덱스트린을 이용한 화학적 토양세정을 다룬다. 두가지 polycyclic aromatic hydrocarbon인 phenanthrene과 naphthalene을 오염물질로 선정하고 토양종류 및 세정강도를 주변수로 하여 수직칼럼 상에서의 오염물질 제거효과를 분석, 고찰하였다. 실험실 규모의 연구결과, 오염원 제거효율은 세정액의 유량, 농도, 온도 및 토양칼럼의 공극률에 비례하는 것으로 나타났으며, 형광광도 분석과 methylene blue와 같은 염료 라벨링 분석을 통하여 초기 세정은 토양과 계면활성제의 흡착에 의존하고 세정이 거듭될수록 유체흐름에 의한 전단력이 주요변수임을 확인할 수 있었다. 본 데이터는 향후 pilot 규모의 현장세정시 기초자료로 활용가능하며, 세정전략 (회분식, 연속식)수립에 유용할 것으로 사료된다.

• 농업과학연구
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• 제39권4호
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• pp.569-575
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• 2012

This study was performed to investigate the effect of a sequencial washing of organic acid and distilled water on meat quality and the population of Escherichia coli of pork loin during cold storage. E. coli ATCC25922 was inoculated on the surface of sliced pork loin and 50 mL of 1% or 2% of organic acid and the same amount of distilled water was sprayed on the surface of pork loin. Then, physicochemical and microbial properties of pork loin were analyzed during cold storage. During storage period, lightness, yellowness and lipid oxidation (thiobarbituric acid reactive substances value) was higher than those of not treated control. However, the population of E. coli was decreased significantly in formic acid and distilled water sprayed pork loin samples. From these results, it can be considered that application of combination of washing of formic acid and water in the washing step of pig slaughter may be helpful to control the proliferation of E. coli.

• 한국환경교육학회지:환경교육
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• 제8권1호
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• pp.66-80
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• 1995

The purpose of this study was to investigate the housewives's recognition and practice on prevention of environmental pollution. The subjects of this study were 250 housewives, school students' mothers, living in Cheong-ju. Major findings were as follows: 1. In washing their faces and brushing their teeth, they saved the water very well, but in taking bath, washing the dished, using the water of the lavatory they did not save the water so well. 2. The kinds of the cleansers differed in taking a bath, washing the hair, and doing the laundry respectively : what they use most was hard soaps in taking bath, liquid cleansers mixed with shampoo and linse in washing the hair, and synthetic powder detergent in laundrying. They used more synthetic detergent than natural soaps, which is known to be a cause of water pollution. Especially, when they cleansed, they did not use a measuring cup. It resulted in the waste of detergent and accelerating of water pollution. Therefore, the environmental education for them was very urgently needed. 3. In handling domestic waste, the separate collection rate of empty bottles and old newspapers was very high, but that of used phone-call cards and used batteries was extremely low. It was truly nessesary to educate and step up publicic activities on the separate collection of phone-call cards and batteries caused environmental pollution. 4. The housewives had much knowledge about environmental pollution, but they did not practice it so well in their home. 5. The housewives made more effort than their children in preventing environmental pollution and saving resources. In conclusion, what is most important for solving environmental problem was for each citizen to make an effort to prevent environmental pollution, and the government's support and producing the atmosphere of the society for this was really needed.

• 한국식품영양과학회지
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• 제39권4호
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• pp.637-642
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• 2010

생식 원재료 전처리공정은 1차 세척-침지-2차 세척-절단공정으로 구성되며, 본 연구에서는 hypochlorous acid를 침지공정에 적용하여 미생물을 제어하고자 하였다. 전처리 단계에서 1차 세척 후에는 감자, 당근, 케일 및 신선초의 총균수는 4.7, 5.3, 5.6, 5.7 log CFU/g이 검출되었으며, 이를 물에 5분간 침지한 경우에는 각각 0.2, 0.2, 0.4, 1.1 log CFU/g를 감소시켰다. 반면 1차 세척 후 100 ppm hypochlorous acid 용액에 5분간 침지한 시료들은 0.5, 0.5, 1.3, 2.8 log CFU/g를 감소시켜 살균효과가 더 좋았으며, 구근류(감자, 당근)보다는 엽채류(케일, 신선초)에 효과적이었다. 하지만 흐르는 물로 세척이 끝난 채소류는 절단공정을 거친 후 다시 0.1~2.7 log CFU/g만큼 미생물수가 증가하였다. 따라서 감자, 당근, 케일, 신선초에 대해 절단공정을 먼저하고 나서 침지하는 공정을 한 경우, 물을 사용하였을 때는 각각 0.9, 0.6, 0.6, 0.4 log CFU/g, hypochlorous acid 용액에 침지한 후에는 각각 3.2, 2.3, 2.5, 2.6 log CFU/g를 감소시켰다. 결론적으로 1차 세척-절단-침지-2차 세척으로 공정을 개선하고 침지단계에서 hypochlorous acid 용액을 처리하는 것이 일반미생물과 유해미생물을 효과적으로 제어할 수 있는 방법으로 나타났다.