• Nuclear Engineering and Technology
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• 제26권2호
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• pp.312-323
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• 1994

1986년 12월 미국의 Surry Unit 2 발전소에서 발생한 급수배관의 대형 파손사고가 침식-부식(erosion-corrosion) 현상에 의해 일어난 것으로 밝혀진 이후, 조사 결과 2차계통에 광범위하게 사용되는 탄소강, 저합금강 재질에서 이와 유사한 손상사례가 많이 나타나는 것으로 밝혀졌다. 이러한 침식-부식 손상은 물-증기로 이루어진 계의 단상(water) 또는 2상(water-wet steam) 조건에서 발생된다. 국내의 원자력 발전소 2차계통에서도 이러한 침식-부식 손상이 나타나고 있으며, 현재 손상원인 해석과 이에 대한 대책 수립이 시급히 요청되고 있다. 본 기고문은 국내 원전의 침식-부식 손상조사와 이의 대책수립을 위한 연구에 활용될 수 있는 침식-부식 손상의 개념, 현상학적 양상, 주요인자의 영향 및 해외 원전의 손상경험 사례 등을 종합하여 정리한 것이다.

• 한국수소및신에너지학회논문집
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• 제29권6호
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• pp.620-626
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• 2018

Recently, fuel cell field is receiving much attention as an environmentally friendly energy in the world. Among the various types of fuel cells, in the case of PEMFC, ions move through the membrane in the middle of the unit cell. Therefore, proper moisture is required inside the PEMFC. In the case of membrane type humidifier, flat membrane or hollow fiber membrane is mainly used. Since various parameters can change the performance, the performance investigation has to be carried out with parameters. In this study, water transport of hollow fiber membrane was investigated in terms of principle operating conditions such as temperature and flow rate.

• Korean Chemical Engineering Research
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• 제50권5호
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• pp.837-842
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• 2012

폐기물 고형연료의 순환유동층 연소기술의 시범을 위하여 파일롯트 규모 순환유동층 연소보일러를 설계하고 건설하였다. 보일러의 규모는 출력기준 약 6 MWth에 해당하며 증기질은 $400^{\circ}C$, 38 ata로 설계하였다. 최대 증기출력은 약 8 ton/h에 해당한다. 연료는 RDF로 휘발분을 주성분으로 하며 점화가 빠르고 연소성이 매우 뛰어났으며 보일러의 연소효율은 99.5%를 능가하였다. 순환유동층 RDF 연소의 안정성은 연료중 회분 이외의 이물질의 존재 여부와 신속한 배출 가능성에 크게 의존하였다. 오염물질의 배출농도는 염소를 제외하고는 법적 기준치 이내에 들었다. 또한 60% 정도의 연료중 염소는 비산재에 흡수되는 것으로 나타났다. HCl을 국내 법 규제에 맞추어 제어하기 위해서는 건식 또는 습식 흡수 장치와 같은 별도의 환경설비가 필요하였다.

• 한국자연치유학회지
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• 제10권2호
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• pp.71-76
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• 2021

Background: The understanding of back-pain as one of the commonest clinical presentations, made the path to the present study. More than three-quarters of the world's population experience back-pain at some time in their lives Purpose: The present study has evaluated the selected Naturopathic therapeutic procedures on individuals with low back-pain. Methods: Thirteen patients were selected for the study and randomly divided into two groups, viz., Group A, Naturopathic group and Group B, Control group. One patient discontinued. Naturopathic group was treated with mud pack, aromatherapy massage with Eucalyptus oil, acupressure, steam, wet trunk pack, exercises, relaxation and breathing exercises. Advice for life style and diet was given for patients of both the groups. The effect of the therapy was assessed subjectively and objectively. Particular scores drawn for Naturopathic group and control group were individually analyzed before and after treatment and the values were compared using standard statistical protocols. Results: Naturopathic intervention revealed 100% relief in both subjective and objective parameters (i.e., 6 out of 14 parameters showed statistically highly significant P < 0.01 results, while 8 showed significant results P < 0.05). Conclusion: Statistically highly significant results of this study point out the successful management of the multi factorial low back-pain with a multi focused Naturopathic treatment approach. Such encouraging results may pave the way for a future study on a large sample in a longer duration incorporating clinical investigations.

• 펄프종이기술
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• 제47권5호
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• pp.98-103
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• 2015

The reduction of the energy consumption in papermaking process become more important issue because of the regulation of green house gas (GHG) emission. Since more than half of energy for papermaking process is consumed during drying process, the increase of the drying efficiency would be very important solution for saving energy and reduction of GHG emission. The improvement of drying efficiency could be very difficult for the liner board mill because the liner board are usually made of recycled paper, OCC (old corrugated container). The short fiber and fines originated the OCC lead to compact sheet structure and delay the water flow out during wet pressing process and drying process. The application of lignocellulose spacer could provide more loose wet sheet structure and result in the higher drainage rate and the improved drying efficiency. In this study, the effects of the application of lignocellulose spacer to the liner board mill were evaluated based on the mill trial. In order to overcome the common disadvantage of the spacer, the loss of strength properties, the spacer was pretreated with amphoteric polyelectrolyte during mill trial. The results showed the application of pretreated spacer improved the drying efficiency by reducing steam consumption. And the loss in the strength properties by the spacer could be supplemented by the pretreatment.

• 한국염색가공학회지
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• 제13권2호
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• pp.120-127
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• 2001

In order to make a microfiber fabric with PET/Co-PET Sea-Island Type microfiber, the optimum condition of extraction and elimination of Co-PET from the mocrofiber was examined. At the same time, the physical property change of the fabric with respect to the change of the relative amount of the Co-PET in the microfiber was also examined to provide a directly applicable data set to the industry. The sample fabric used was warp 75/36(DTY) and weft 0.05d(PET/Co-PET, Sea Island Type Microfiber) twill fabric of 36 separated yarns＋40/24(high shrinking yarn) with 130/48 ITY. The data set was made at various NaOH concentrations and steam temperatures with time as a main variable. The physical properties examined were the tensile properties. The results obtained were the tensile. The results obtained were 1. For a proper extraction of Co-PET (13.5%)from the microfiber with wet curing, it takes more than 5 min. in 8 and 12% of NaOH solutions but it takes only 3 min. in 18% of NaOH solution at 12$0^{\circ}C$. 2. For a proper extraction of Co-PET (13.5%) from the microfiber with wet curing, ti takes 3~5min. in 12 and 14% of NaOH solution and it takes less than 3 min. in 18% of NaOH solution at $130^\circ{C}$. 3. The increasing ratio of WT increased with increasing NaOH concentrations and the equilibrium point reached was 3 min. at $120^\circ{C}$. 4. The WT increasing ratio was greater in 14 and 18% NaOH solutions than in 8 and 12% of NaOH solutions at $130^\circ{C}$5. The RT ratio changes at $120^\circ{C}$ in 8 and 12% of NaOH solutions were indifferent from that at $130^\circ{C}$ in 12% of NaOH solution. However, the RT was apparently decreased with increasing NaOH concentration.

• 한국염색가공학회지
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• 제13권2호
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• pp.34-34
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• 2001

In order to make a microfiber fabric with PET/Co-PET Sea-Island Type microfiber, the optimum condition of extraction and elimination of Co-PET from the microfiber was examined. At the same time, the physical property change of the fabric with respect to the change of the relative amount of the Co-PET in the microfiber was also examined to provide a directly applicable data set to the industry. The sample fabric used was warp 75/36(DTY) and weft 0.05d(PET/Co-PET, Sea Island Type Microfiber) twill fabric of 36 separated yarns＋40/24(high shrinking yarn) with 130/48 ITY. The data set was made at various NaOH concentrations and steam temperatures with time as a main variable. The physical properties examined were the tensile properties. The results obtained were the tensile properties. The results obtained were 1. For a proper extraction of Co-PET (13.5%)from the microfiber with wet curing, it takes more than 5 min. in 8 and 12% of NaOH solutions but it takes only 3 min. in 18% of NaOH solution at 120℃. 2. For a proper extraction of Co-PET (13.5%) from the microfiber with wet curing, it takes 3∼5 min. in 12 and 14% of NaOH solution and it takes less than 3 min. in 18% of NaOH solution at 130℃. 3. The increasing ratio of WT increased with increasing NaOH concentrations and the equilibrium point reached was 3 min. at 120℃. 4. The WT increasing ratio was greater in 14 and 18% NaOH solutions than in 8 and 12% of NaOH solutions at 130℃. 5. The RT ratio changes at 120℃ in 8 and 12% of NaOH solutions were indifferent from that at 130℃ in 12% of NaOH solution. However, the RT was apparently decreased with increasing NaOH concentration.

• 전기전자학회논문지
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• 제23권3호
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• pp.1077-1081
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• 2019

태양전지의 표면으로 입사되는 빛은 태양전지의 내부로 모두 흡수되지 못하고 그 일부가 기판 표면에서 반사되어 손실이 발생한다. 때문에 기판 표면의 반사손실을 줄이거나 태양전지 내부의 생성 전하를 증기시키기 위한 연구가 많이 진행 중이다. 본 논문에서는 유리 기판의 표면을 습식 에칭하여 표면을 거칠게 형성하는 표면 처리를 진행하였으며, 거칠어진 표면의 구조적 특성을 분석하였다. 그리고 빛이 입사되는 유리 기판의 각도를 변화하면서 그에 따른 분광특성 또한 분석하였다. 입사되는 빛이 에칭된 표면으로 조사될 때 다중반사에 의해서 유리 기판 내부에 빛을 재흡수할 확률이 증가함을 확인하였다. 또 유리 기판의 각도를 변화하면서 빛을 입사할 때 빛의 투과 및 반사 성능은 변화하지 않음을 확인하였다.

• Korean Chemical Engineering Research
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• 제53권3호
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• pp.372-381
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• 2015

본 연구에서는 $Ni/Al_2O_3$ 촉매를 사용한 에틸렌글리콜의 수증기 개질반응에서 제조 방법에 따른 영향을 알아보았다. 촉매들은 건식 함침법, 습식 함침법 그리고 공침법을 사용하여 제조하였다. 공침법을 사용하여 촉매 제조시 침전제를 KOH, $K_2CO_3$, $NH_4OH$를 각각 사용하여 침전제에 따른 영향 또한 알아보았다. 제조한 촉매들은 질소 물리흡착, 유도결합 플라즈마 질량분석법(ICP-AES), X선 회절법(XRD), 수소 승온 환원법(TPR), 수소 화학흡착, 승온 산화법(TPO), 주사전자현미경(SEM), 열분석법(TGA)을 사용하여 촉매의 물리화학적인 특성을 분석하였다. 773 K에서 환원한 촉매의 경우 KOH 혹은 $K_2CO_3$를 침전제로 사용하여 공침법으로 제조한 촉매가 가장 높은 활성을 보였다. 촉매 제조 방법은 Ni의 입자크기, Ni 산화물의 환원도, 반응에서의 활성과 안정성, 반응 중 탄소 침적의 형태 등에 영향을 끼치는 것을 확인할 수 있었다. KOH를 침전제로 사용하여 공침법으로 제조한 촉매의 경우 환원온도를 773~1173 K까지 증가시켰을 때, Ni 입자크기의 증가에도 불구하고 Ni 산화물의 환원도가 증가하므로 반응활성이 증가하는 것으로 나타났다.

• 대한영양사협회학술지
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• 제16권4호
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• pp.318-331
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• 2010

The objectives of this study were to investigate the status of accidents and to assess hazards in institutional foodservices in the Changwon and Masan areas. A survey was conducted from February 1 to March 31, 2009 using questionnaires, and 142 dietitians participated. The dietitians' perception of accident risks in workplace averaged 3.11 points. Forty-five percent of the respondents responded that accidents had occurred more than once between 2006 and 2008. In addition, 28.2% of the respondents experienced employee absences or turnover due to accidents during Year 2008. 'Musculoskelectal injuries or disorders (65.5%)', 'slips or falls (64.8%)', 'burns (57.7%)', and 'cuts and punctures (48.6%)' were the predominant accidents in foodservice. 'Knives (76 points)', 'steam kettles (41 points)', 'vegetable cutters (34 points)' and 'turn kettles (26 points)' were the equipment with severe accidents, such as burns or cut injuries. Among foodservice processes, 'carpal tunnel syndrome while washing (2.83 points)', 'burned by frying oil (2.64 points)', 'cut by sharp tools (2.55 points)', 'musculoskelectal injury by moving heavy weight food materials (2.41 points)', and 'injury by slipping on wet workplace floors and trenches (2.19 points)' were the most frequently occurring accidents at foodservice sites. To prevent safety accidents, dietitians' perceptions of safety supervision should be improved, and therefore, it is necessary they receive safety education.