• 한국세라믹학회지
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• 제39권3호
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• pp.299-307
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• 2002

본 연구에서는 복잡 형상의 세라믹체를 효율적으로 성형할 수 있어 새로운 성형기법으로 부각되고 있는 직응집성형(Direct Coagulation Casing, DCC)공정기술에 관하여 콜로이드 계면화학을 이용하여 연구하였다. 높은 고형분량을 가지는 안정된 질화규소 슬립을 제조하기 위하여 분산제, 소결조제 그리고 응집제 각각이 다양한 공정변수에 미치는 영향에 대하여 평가하였다. 1.0 wt% Tetraethylammonium Hydroxide(TEAH)를 첨가하여 염기영역에서 소결조제를 포함한 안정된 51vol%의 질화규소 슬립을 제조할 수 있었다. 질화규소 슬립은 첨가된 $Al(CH_3COO)_2OH$의 온도증가에 따른 열분해를 이용하여 직응집성 유도하였다. 염기영역에서 $Al^{3+}$ 이온들이 aluminum hydroxide$(Al(OH)_3)$ 석출되면서 슬립내 $OH^-$ 농도를 감소시켜 질화규소 슬립을 직응집시켰다.

• 대한화학회지
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• 제38권10호
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• pp.763-768
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• 1994

Dolastatin 10의 유사체를 합성하기 위한 연구의 일환으로 여러 형태의 펩티드 화합물의 합성 경로를 연구하였다. 유사체의 합성에 사용된 4-amino-3-hydroxy acid는 에폭시 화합물의 아민에 의한 고리열림에 의하여 합성하였다. 이 비단백질 아미노산응로부터 주로 DCC 축합에 의하여 펩티드 화합물을 합성하였다.

• 한국세라믹학회지
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• 제35권2호
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• pp.180-184
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• 1998

It was examined that the rheological behaviors of fly ash 70wt%-clay 30wt% slip in which nonplastic fly ash was a major component. We have systematically investigated the effects of deflocculant(Tetrasodium pyrophosphate ; Na4P2O7 nH2O Sodium silicate; Na2SiO3) and coagulant(CaSO4) on the rheological behavior of ash-clay slip. Ash-clay slip have been characterized on the basis of the time dependent rheology which was done out by the gel-curve test. Dispersion mechanism of ash-clay slip is the steric stabilization by the Na2SiO3 coating of cenospheres surface. Coagulated slip seems to have the new network structure and shows the gellation behaviors which makes it possible to direct coagulated casting(DCC).

• 대한화학회지
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• 제35권1호
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• pp.78-84
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• 1991

Enkephalin의 작용을 연장하기 위한 연구이 하나로서 수개의 enkephalin aminopeptidase의 저해물을 합성하였다. 이 펩티드성 저해물은 zinc 결합자리로서 3-amino-2-hydroxy amino acid와 기질양상의 곁사슬을 가진다. 펩티드들은 용액 중에서 DCC/HOBt를 축합시약으로 사용하여 C-말단으로부터 사슬 연장법으로 합성하였다. 합성한 펩티드 저해물들은 모두 enkephalin aminopeptidase에 대하여 강한 저해 작용을 나타내었다.

• 한국환경보건학회지
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• 제46권5호
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• pp.495-503
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• 2020

Objective: This study aimed to compare the characteristics of humidifier disinfectant-like products (HD-like products) and humidifier disinfectant products (HD products) and introduce actual cases of the usage of HD-like products in hospitals based on an on-site investigation. Methods: The characteristics, chemical components, and usage of HD-like products (Hichlor or Biospot) and HD products (N-with) containing NaDCC (sodium dichloroisocyanurate) were compared. In the process of conducting the on-site investigation, four hospitals were identified as previously using HD-like products. Each on-site investigation to identify the use of HD-like products was composed of four parts: 1) hospital infection control guidelines, 2) manual for humidifiers in patient's rooms, 3) interviews with nursing staff, infection managers, and purchase managers, 4) searching on the product purchase system. Results: Although HD-like products (Hichlor and Biospot) and HD products (N-with) were sold for different usage purposes, they were all white-colored and coin-shaped foaming tablets with the same chemical component, NaDCC. The manual for using HD-like products and HD products was similar (inserting the tablet in a humidifier container with water). Among the four hospitals, one had used Hichlor in the same manner as HD (N-with) by inserting a tablet in 1L of water in a filled humidifier container and Biospot as a kind of detergent for humidifier container cleaning. Another two hospitals had used Biospot and/or Aniosyme as a kind of detergent for humidifier container cleaning. The other hospital had used unknown product in the same manner as N-with, so we thus assumed it was either an HD products (N-with) or HD-like products (Hichlor, Biospot). Conclusion: This study raises the possibility of the development of adverse health effects similar to exposure to an HD-products when exposed to an HD-like products and the possibility of further use in other medical institutions or multi-use facilities. Therefore, an expansion of the investigation is needed in order to confirm whether there have been similar cases in the past.

• 국제지역연구
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• 제21권4호
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• pp.223-245
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• 2017

본 연구의 목적은 다변량 GARCH(DCC)모형을 이용하여 탄소시장과 주식시장간 상호 영향력을 분석하는 데 있다. 탄소시장은 유럽 배출권거래제(EU ETS)의 탄소가격을, 주식시장은 에너지 소비와 탄소 배출이 상대적으로 많은 유럽의 철강 및 시멘트부문의 주식가격을 대상으로 하였다. 또한, 상관계수 분석을 통하여 시장간 상관관계 변화를 분석하였다. 이를 통해, 새로운 상품인 탄소시장의 시장성 확대(또는 배출저감 확대) 여부를 확인해 보았다. 기존 연구와 달리, (1) 배출권거래제 시작부터 2단계가 완료된 시점인 2012년까지의 자료를 모두 활용하며 (2) 전력부문에 집중된 기존연구와 달리 두 번째로 에너지 다소비 탄소 다배출부문인 철강과 시멘트부문을 대상으로 하며 (3) 수익률의 영향뿐만 아니라 변동성의 파급효과를 추가하며 (4) 시장의 동시적 상관성을 고려하여 다변량 변동성 모형인 DCC(Dynamic Conditional Correlation) 모형을 활용하였다. 분석결과, 가격 전이효과가 미미하고, 변동성 전이효과도 금융위기라는 외부충격에 의해 2단계에서 소멸하여 양 시장간에는 약한 상관관계를 유지하는 것으로 나타났다. 탄소시장과 주식시장간 상관관계는 약간 상승하는 추이를 보이지만 뚜렷한 변화를 발견하지 못하였다. 따라서, 탄소배출권은 하나의 상품으로서 금융시장으로의 시장성 확대가 미진한 것으로, 또는 배출저감이라는 본연의 역할을 수행하지 못하고 있는 것으로 해석할 수 있겠다.

• 농약과학회지
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• 제17권2호
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• pp.140-143
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• 2013

톱다리개미허리노린재의 페로몬 성분인 (E)-2-hexenyl (E)-2-hexenoate (1) 과 (E)-2-hexenyl (Z)-3-hexenoate (2)의 합성에 있어 Steglich 에스테르화 반응의 최적 조건을 검토하였다. (E)-2-헥센산 또는 (Z)-3-헥센산에 대하여 1-1.5 당량의 디사이클로카보다이이미드 (DCC), 1.5-2.0 당량의 (E)-2-헥센놀과 0.1 당량의 4-디메틸아미노피리딘(DMAP)과 반응하였을 때, 각각 76-78% 와 87-91%의 수율로 1과 2를 얻었다.

• 한국입자에어로졸학회지
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• 제13권2호
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• pp.65-77
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• 2017

In recent large-scale semiconductor manufacturing cleanrooms, the energy consumption in outdoor air conditioning (OAC) systems to heat, humidify, cool and dehumidify outdoor air(OA) represents about 40~50 % of the total cleanroom power consumption required to maintain cleanroom environment. Therefore, the assessment of energy consumption in outdoor air conditioning systems is essential for reducing the outdoor air conditioning load for a cleanroom. In the present study, an experiment with an outdoor air flow rate of $1,000m^3/h$ was conducted to compare the energy consumption in steam humidification, simple air washer, exhaust air heat recovery type air washer and dry cooling coil(DCC) return water heat recovery type air washer OAC systems. Besides, a numerical analysis was carried out to evaluate the annual energy consumption of the aforementioned four OAC systems. It was shown that the simple air washer, exhaust air heat recovery type air washer and DCC return water heat recovery type air washer OAC systems using water spray humidification were more energy-efficient than the steam humidification OAC system. Furthermore the DCC return water heat recovery type air washer OAC system was the most energy-efficient.

• 설비공학논문집
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• 제24권4호
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• pp.297-305
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• 2012

In recent large-scale semiconductor manufacturing clean rooms, the energy consumption of outdoor air conditioning systems to heat, humidify, cool and dehumidify incoming outdoor air represents about 45% of the total air conditioning load required to maintain a clean room environment. Therefore, the energy performance evaluation and analysis of outdoor air conditioning systems is useful for reducing the outdoor air conditioning load for a clean room. In the present study, an experiment was conducted to compare the energy consumption of outdoor air conditioning systems with a simple air washer, an exhaust air heat recovery type air washer and a DCC return water heat recovery type air washer. It was shown from the present lab-scale experiment with an outdoor air flow of 1,000 $m^3/h$ that the exhaust air heat recovery type and DCC return water heat recovery type air washer outdoor air conditioning systems were more energy-efficient for the summer and winter operations than the simple air washer outdoor air conditioning system and furthermore, the DCC return water heat recovery type one was the most energy-efficient in the winter operation.

• 한국간담췌외과학회지
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• 제26권2호
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• pp.168-177
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• 2022

Backgrounds/Aims: The goal of the present study was to evaluate the prognostic value of lymph node ratio (LNR) in distal cholangiocarcinoma (DCC) after curative intended surgery. Methods: Clinicopathological data of 162 DCC patients who underwent radical intended surgery between 2012 and 2020 were analyzed retrospectively. Prognostic factors related to overall survival (OS) and disease-free survival (DFS) were evaluated. Results: Median OS time and DFS time were 41 and 29 months, and 5-year OS rate and DFS rate were 44.7% and 38.1%, respectively. In the univariate analysis, significant prognostic factors for OS were histologic differentiation, American Joint Committee on Cancer (AJCC) stage, positive lymph node count, LNR, R1 resection, and perineural invasion. Preoperative carcinoembryonic antigen, carbohydrate antigen 19-9, infiltrative type, histologic differentiation, AJCC stage, positive lymph node count, LNR, R1 resection, perineural invasion, and lymph-vascular invasion were significant prognostic factors for DFS in the univariate analysis. In the multivariate analysis, histologic differentiation, R1 resection, and LNR were the independent prognostic factors for both OS and DFS. The LNR ≥ 0.2 group had a significantly poor prognosis in terms of OS (hazard ratio, 3.915; p = 0.002) and DFS (hazard ratio, 5.840; p < 0.001). Conclusions: LNR has significant value as a prognostic factor of DCC related to OS and DFS. LNR has the potential to be used as a modified staging system with furthermore studies.