• 접착 및 계면
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• 제7권4호
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• pp.32-38
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• 2006

A series of organic-inorganic hybrids, PCL/EP/$SiO_2$, involving epoxy resin and triethoxysilane-terminated polycaprolactone elastomer (PCL-TESi) were prepared via polymerization of diglycidyl ether of bisphenol A (DGEBA) with amine curing agent KB-2 and sol-gel process of PCL-TESi. The curing reactions were started from the initially homogeneous mixture of DGEBA, KB-2 and the PCL-TESi. The organicinorganic hybrids containing up to 4.95% (wt) of $SiO_2$ were obtained and characterized by FT-IR, transmission electron microscopy (TEM), differential scanning calorimetry (DSC) and thermogravimetry analysis (TGA). It was experimentally shown that the swelling property in toluene, morphologies and thermal properties of the resulting hybrids were quite dependent on the contents of $SiO_2$. The crosslink network density decreases with increasing of the PCL-TESi. And in TEM, the phase separated morphology of these hybrids was found, which resulted from the coagulation of Si-O-Si networks resulting from $-Si(OC_2H_5)_3$ of PCL-TESi self-curing by hydrolytic silanol condensation, with the advancement of the curing reaction in the modified epoxy resin systems. Meanwhile, the change of the $SiO_2$ content made the morphologies changed from aggregated particles of Si-O-Si in the hybrid to nanocluster of interconnected Si-O-Si particles, then to aggregated Si-O-Si dispersing in the continuous cured epoxy phase again, and last to co-continuous interpenetrating network. The glass transition behavior of the hybrid material was cooperative motion of large chain segments, which were hindered by the inorganic Si-O-Si network. And in TG analysis, the characteristic temperature at 5% of weight loss was evidently increased from $120.5^{\circ}C$ of pure cured epoxy to $277.6^{\circ}C$ of 3.84% (wt) of $SiO_2$ modified epoxy due to the existence of Si-O-Si when PCL-TESi was added in the hybrid.

• 한국콘텐츠학회논문지
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• 제15권6호
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• pp.606-615
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• 2015

본 연구는 기존의 서양 중심 세계사를 바탕으로 한 암기식 교육의 문제를 개선 하고자 거대사 관점의 새로운 역사 교육 콘텐츠 개발 방향을 제시하는 것이 목적이다. 연구의 범위는 인류문화가 시작된 농업혁명부터 산업혁명까지의 역사적 사건으로 설정하였다. 전문가들을 대상으로 한 델파이 기법을 통해 총 56개의 주요 역사적 콘텐츠를 도출하였고, 이를 사회연결망 분석의 데이터로 활용하였다. 사회연결망 분석을 통한 개별 콘텐츠의 영향력 분석 결과, 총 56개의 역사적 핵심사건 가운데 가장 영향력이 큰 사건의 키워드는 문명의 발생으로 나타났다. 또한 역사적 사건 키워드 네트워크를 구축하여 시각적으로 응집 분석한 결과 7개의 그룹으로 키워드가 분류되는 것으로 나타났다. 이러한 결과는 현행 교과과정의 시대별 분류기준과는 다른 새로운 분류기준으로 본 연구에서 제안한 역사 교육 콘텐츠 개발 체계는 거대사 관점에서 역사교육 콘텐츠 네트워크를 구성한 새로운 역사 해석 방법이 될 것으로 기대한다.

• Childhood Kidney Diseases
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• 제22권2호
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• pp.52-57
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• 2018

Purpose: Rhabdomyolysis is a metabolic disorder in which the content of damaged muscle cells is released into plasma. Its manifestations include asymptomatic, myalgia, gross hematuria, and complications of acute kidney injury. Because of limited data on rhabdomyolysis in children, we performed this study to determine clinical characteristics of rhabdomyolysis in children. Methods: We retrospectively reviewed the records of patients with rhabdomyolysis who were treated at the Pusan National University Children's hospital from January 2011 to July 2016. The diagnostic criteria were serum myoglobin level of ${\geq}80ng/mL$, exclusive of acute myocardial injury, cardiac arrest, and brain damage. Results: Forty-five patients were enrolled; mean age, $116{\pm}68$ months. Of these, 35 were boys and 10 were girls. Twenty-six patients experienced myalgia and 12 patients showed gross hematuria. Among these, seven patients initially had both myalgia and gross hematuria. The most common causes of rhabdomyolysis were infection, physical exertion, prolonged seizures, metabolic abnormalities, and drug addiction. Acute kidney injury (AKI) was the most common complication, followed by disseminated intravascular coagulation. Thirty-seven patients improved with sufficient fluid supply but two patients underwent hemodialysis due to deterioration of kidney function. Gross hematuria, positive occult blood test, and positive urine protein were more common in patients with AKI than in those without AKI. Conclusions: In children, infection was the most common cause of rhabdomyolysis. Most patients recovered by sufficient fluid therapy. However, in severe cases, especially in patients with underlying kidney disease, hemodialysis may be necessary in the present study.

• 한국지반신소재학회논문집
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• 제12권3호
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• pp.87-94
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• 2013

최근 국내의 준설퇴적오니 오염문제가 부각되고 있으며, 이에 따라 퇴적오니 오염의 정화를 위한 기술의 필요성이 증대되고 있다. 국내에서는 준설퇴적물에 응집제를 투입하여 응집 침전 후 탈수하여 매립하고 있으나, 과도한 슬러지 발생과 운송비 부담 등으로 경제성이 떨어져 새로운 처리방법의 필요성이 대두되고 있다. 이에 본 연구에서는 준설퇴적물 내 오염물질은 큰 입자에 비하여 작은 입자에 강하게 흡착되어 있어 입자별로 분리하면 처분량 및 처분비용을 감소시킬 수 있고, 후속처리 공정에 효율적인 하이드로사이클론을 통한 전처리기술을 이용하여 준설퇴적물 처리의 적합성을 파악하였다. 즉, 준설퇴적물의 입자분리를 위하여 하이드로사이클론을 운전한 결과 고형물함량과 유입압력이 분리효율에 큰 영향을 미쳤다.

• 한방비만학회지
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• 제14권1호
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• pp.1-12
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• 2014

Objectives: The purpose of this study is to analyse research trends about medical leech in the last 10 years. Methods: We searched the papers with key words of 'medical leech', '水蛭' in China Knowledge Resource Integrated Database (CNKI), Korean traditional knowledge portal, DBPIA, KISS. We classified the papers by year and content. Results: 1. Result of the classification on the basis of the research methods, 50 studies are clinical case reports, 301 studies are experimental paper, 599 studies are clinical trial study, 219 studies are literature review. 2. Result of the classification on the basis of the research topics, 454 studies are the effect of anticoagulant research, 84 studies are diabetes and renal disease research, 194 studies are pharmacological properties research, and 43 studies are effect of allergic and anti-inflammatory research. 3. The proportion of the coagulation effect study tends to decrease every year since 2006. 4. Leech research tends to decrease in last 3 years. 5. Recently, there are many research in psychiatry, orthopedic diseases and beauty. 6. There are 10 studies related to leech in Korean. Conclusions: The researches of medical leech are actively done. The diversity of subjects is getting wider and richer.

• 한국식품영양과학회지
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• 제20권6호
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• pp.551-558
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• 1991

국내산 Brassica napus, var. Youngsan종 유채단백질의 추출용매 및 공정차이에 따른 이화학적 성질 및 기능성에 대하여 조사하였다. 각 공정별로 얻어진 유채단백질은 정제가 잘 될수록 황색도와 표면소수성이 개선되었다. SDS-PAGE 분석결과 9개의 band가 나타났으며 상당부분이 $1.96~1.59{\times}10^4$ dalton 분자량으로 구성되었고, EDTA 혼합용매로 추출한 경우 저분자량 band가 거의 나타나지 않았다. 아미노산 함량은 정제에 따라 약간씩 높았으나 EDTA 혼합용매로 추출한 단백질에서는 전체적으로 상당히 낮았다. EDTA 혼합용매로 추출한 단백질에서의 용해도가 1% SHMP로 추출한 단백질과 매우 다르게 나타났으며, 동점도는 정제가 잘 될수록 낮은 값이었다. 수분 흡수력과 거품성은 큰 차이가 없었으며, 유흡수력과 에멀젼 활성도는 대조구 보다 약간씩 증가하였으며 대조구에 비하여 다른 모든 처리구의 칼슘에 대한 반응성이 민감하였다. 열응고성은 EDTA 처리구만 높았고 나머지 모든 처리구에서는 상당히 낮은 값으로서 열안정성이 높게 나타났다.

• 한국건축시공학회지
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• 제10권2호
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• pp.59-66
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• 2010

본 연구에서는 흡착 및 내열, 내화성이 우수한 카본블랙을 이용하여, 콘크리트의 제반성능을 파악하여, 콘크리트용 혼화재료로써 활용가능성 여부를 판단하고자 함이 본 연구의 목적이다. 실험결과 굳지 않은 콘크리트에서는 흡수율 및 미립분의 카본블랙의 충전효과로 인하여 슬럼프증가 및 공기량 감소를 나타내었으며, 블리딩, 관입저항에 의한 응결시간은 양호한 결과로 나타났다. 또한 경화콘크리트의 강도 특성에는 Plain보다 높은 강도를 나타내었으며, 포졸란 반응에 의해 장기강도로 갈수록 강도발현이 높게 나타났다. 또한 약 $850^{\circ}C$내외의 가열 후의 압축강도에서 치환율이 증가할수록 내화, 내열성이 높게 나타났으며, 건조수축 역시 양호하게 나타났고, CO, $CO_2$, 포름알데히드의 환경성 평가도 Plain보다 양호한 결과로 나타났다. 이상 결과를 종합하면, 고강도의 배합설계를 고려한 적절한 AE감수제를 사용할 경우 카본블랙이 콘크리트용 혼화재로써 사용이 가능할 것으로 판단된다.

• 폴리머
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• 제37권6호
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• pp.677-684
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• 2013

Alginate를 농도 별로 용액상태로 제조한 후 필름 메이커를 이용하여 필름 형태로 만든 후 3 wt%의 $ZnCl_2$ 수용액에 필름을 고화시킨 후 수세하여 $60^{\circ}C$의 건조기에서 약 20분 동안 건조시켜 zinc alginate 필름을 제조하였다. 필름의 특성을 조사하기 위하여 항균성 및 점도와 FTIR, TGA, SEM, EDS 및 접촉각, 인장측정, 용해도분석 등을 측정하였다. 항균성 시험 결과, zinc alginate 필름에서는 두 균주(포도상구균, 폐렴간균) 모두 우수한 항균력이 나타나는 것을 확인하였다. 9 wt%의 sodium alginate로 제조한 zinc alginate 필름의 표면은 다른 농도별 필름보다 균일한 형태를 나타내었으며, $ZnCl_2$ 응고액에 잘 고화될 때 단단하고 거친 느낌의 단면 형태를 확인하였다. Zinc alginate 필름의 인장강도는 가교결합에 의해 sodium alginate 용액의 농도가 증가함에 따라 증가하였으며, 초기 열 분해 온도가 점차적으로 높아지고 있는 형태를 보였다.

• 한국펄프종이공학회:학술대회논문집
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• 한국펄프종이공학회 2000년도 제26회 펄프종이기술 국제세미나
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• pp.1-10
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• 2000

The development of paper machines, increasing machine speeds with new, mostly low basis weight and/or high ash content paper grades, as well as the fact that several trends regarding process items have increased the sensitivity of papermaking. At the same time, papermakers are looking for flexibility in the production line. We can say that with all PMs the biggest benefits with the lowest capital spending can be achieved by focusing on improved wet end management. In order to manage wet end chemistry on a paper machine, our goal is to control sub-process through which we can influence the operation of the entire wet end with maximum effect. Key measurements and controls are-white water consistency control which is the most effective way to control retention - charge demand measurement and control which takes care of concentration of the anionic material entering to PM -ash measurements and controls which are deeply related to retention and paper quality This paper presents and concentrates to two of these key controls ; retention and charge. The purpose of charge control is to give the process control the tools to react to changes caused by amount of dissolved and colloida material incoming to wet end system. It is called coagulation or fixing control. Retention control is then taking care of retention aid flow to the process by responding any changes seen in white water consistency. It is called flocculation control. Each of these solutions separately , and even more effectively all together, stabilize the wet end operations and so greatly improve the produced paper quality and machine runnability. Practical results will be presented and they are referring to the latest mill cases. We have developed the first wet end measuring system in the late 1980s and control solutions based on this modern measuring technology were completely updated in 1990s. This paper introduces the principle, operation , and results of our unique wet end analyzers (retention and charge ) which are at the level of automation solutions as a part of paper machine quality control Especially our newest member of the platform , on-line charge analyzer has reached and set new standards to the on-line charge monitoring.

• 펄프종이기술
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• 제32권5호
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• pp.44-53
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• 2000

The development of paper machines, increasing machine speeds with new, mostly low basis weight and/or high ash content paper grades, as well as the fact that several trends regarding process items have increased the sensitivity of papermaking. At the same time, papermakers are looking for flexibility in the production line. We can say that with all PMs, the biggest benefits with the lowest capital spending can be achieved by focusing on improved wet end management. In order to manage wet end chemistry on a paper machine, our goal is to control subprocesses through which we can influence the operation of the entire wet end with maximum effect. Key measurements and controls are - white water consistency control which is the most effective way to control retention. - charge demand measurement and control which takes care of concentration of the anionic material entering to PM. - ash measurements and controls which are deeply related to retention and paper quality. This paper presents and concentrates to two of these key controls: retention and charge. The purpose of charge control is to give the process control the tools to react to changes caused by amount of dissolved and colloidal material incoming to wet end system. It is called coagulation or fixing control. Retention control is then taking care of retention aid flow to the process by responding any changes seen in white water consistency. It is called flocculation control. Each of these solutions separately, and even more effectively all together, stabilize the wet end operations and so greatly improve the produced paper quality and machine runnability. Practical results will be presented and they are referring to the latest mill cases. We have developed the first wet end measuring system in the late 1980s and control solutions based on this modern measuring technology were completely updated in 1990s. This paper introduces the principle, operation, and results of our unique wet end analyzers (retention and charge) which are at the level of automation solutions as a part of paper machine quality control. Especially our newest member of the platform, on-line charge analyzer has reached and set new standards to the on-line charge monitoring.