• Restorative Dentistry and Endodontics
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• 제24권4호
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• pp.628-632
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• 1999

Currently electronic apex locators have been widely used to determine working length in endodontic treatment. According to Manufacture's recommendation, it is beneficial to find the working length before instrumenting the canal. However, in crown-down pressureless technique, working length of tooth is established following coronal instrumentation 3mm short of radiographic apex. In narrow canals, mechanically formed constriction might be established by coronal instrumentation in some distance from anatomical constriction. The purpose of this study was to evaluate the accuracy of Root-ZX in the canal with mechanical constriction following considerable coronal enlargement with ProFile .06 series. The 40 root canals in 30 extracted mandibular molars were accessed, and their actual length (AL) established by passing a size 10 file just through the minor apical foramen. The teeth were then embedded in an acrylic container with normal saline. The initial canal length(IL) was measured with Root-ZX by negotiating a size 10 file to the apical constriction. The canal was sequentially enlarged to size 40 with ProFile .06 file 3mm short of actual length. The enlarged final canal lengths (FL) were obtained with a size 15 file. The average values of IL, FL were calculated and compared using Repeated measures Analysis of Variance followed Turkey's Studentized Range test. The results were obtained as follows: 1. The initial canal length was 0.12mm shorter than actual canal length(P>0.05). 2. The differences between initial canal length and final canal length were not significant(P>0.05). 3. As a result of this study, regardless of mechanically formed constriction. Root-ZX differentiated between mechanical and anatomic constriction.

• 한국식품영양과학회지
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• 제32권8호
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• pp.1200-1205
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• 2003

연속식 반응기에서 sn-1,3위치 특이성을 가지는 Rhizomucor miehei lipase(Lipozyme RM IM)를 사용하여 CLA를 함유한 재구성지질을 합성하였다. 옥수수유에 CLA를 transesterification 하기 위한 반응 조건은 연동 펌프의 유속, 반응온도 및 기질의 몰 비율이었다. 연동 펌프의 유속을 변수로 한 실험에서는 유속 1 mL/min, 반응온도 55$^{\circ}C$ 및 1:3 기질몰 비율일 때 재구성지질 중 최대 CLA함량이 10.26 ㏖%을 보였으며, 반응온도를 변수로 한 반응에서는 반응온도가 $65^{\circ}C$일 때 최대 CLA함량 17.33 ㏖%을 나타냈다. 또한 반응 기질의 몰 비율을 변수로 한 재구성지질 합성에서는 1:5몰 비율에서 최대 CLA 함량 17.50 ㏖%을 보였다. Pancreatic lipase analysis 통하여 재구성 지질의 sn-1,3과 sn-2 위치 지방산 조성을 분석하였고 재구성지질의 불포화도를 측정하기 위하여 요오드 값을 측정한 결과 유속 1 mL/min, 반응 온도 55$^{\circ}C$, 몰 비율 1:5 조건에서 120의 실험 조건 내에서 가장 큰 요오드 값을 나타내었다. 한편 각각의 재구성지질 HPLC 분석 결과 99%의 TAG와 1% 이내의 DAG와 MAG가 분석되었다.

• 한국시뮬레이션학회논문지
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• 제24권4호
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• pp.59-68
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• 2015

본 논문에서는 전투 시스템 중 대표적인 지상 공격 수단인 전차를 대상으로 모델링 및 시뮬레이션 기법을 적용한 취약성 분석 방법에 관한 내용을 다룬다. SES/MB(System Entity Structure/ Model Base) 프레임워크는 복잡한 시스템의 구조를 계층적으로 표현할 수 있으며, 다양한 부품으로 구성된 전차를 모델링하기에 용이하다. 전차의 취약성은 전차가 위협탄에 의해 피격되었을 때, 장갑 및 부품이 파손되거나 관통된 것을 기준으로 분석할 수 있으며 관통 여부는 관통 해석식을 통해 위협탄의 관통 성능과 장갑 및 부품의 방호 성능을 비교한 결과에 따라 결정된다. 방호 성능은 일반 부품과 장갑으로 분류한 전차의 부품 종류 및 정의한 속성에 따라 결정되고, 모든 부품은 중요도를 산정하기 위한 가중치를 가진다. 전차의 취약성을 분석하기 위해 개발한 시뮬레이션 프로그램에서는 위협탄에 의해 관통된 부품 및 피해를 입은 부품의 중요도를 기반으로 하여 전체 취약성을 분석하고, 개별 부품이 전차에서 담당하는 기능을 정의하여 기능별 피해 기준에 따라 취약성을 분석한다.

• Bulletin of the Korean Chemical Society
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• 제32권3호
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• pp.857-862
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• 2011

Kinetic studies of the reactions of N-methyl-Y-${\alpha}$-bromoacetanilides with substituted X-benzylamines have been carried out in dimethyl sulfoxide at $25.0^{\circ}C$. The Hammett plots for substituent X variations in the nucleophiles (log $k_N$ vs ${\sigma}_X$) are slightly biphasic concave upwards/downwards, while the Bronsted plots (log $k_N$ vs $pK_a$) are biphasic concave downwards with breakpoints at X = H. The Hammett plots for substituent Y variations in the substrates (log $k_N$ vs ${\sigma}_Y$) are biphasic concave upwards/downwards with breakpoints at Y = H. The cross-interaction constant $\rho_{XY}$ values are all negative: $\rho_{XY}$ = -0.32 for X = Y = electron-donating; -0.22 for X = electron-withdrawing and Y = electron-donating; -1.80 for X = electron-donating and Y = electronwithdrawing; -1.43 for X = Y = electron-withdrawing substituents. Deuterated kinetic isotope effects are primary normal ($k_H/k_D$ > 1) for Y = electron-donating, while secondary inverse ($k_H/k_D$ < 1) for Y = electronwithdrawing substituent. The proposed mechanisms of the benzylaminolyses of N-methyl-Y-${\alpha}$-bromoacetanilides are a concerted mechanism with a five membered ring TS involving hydrogen bonding between hydrogen (deuterium) atom in N-H(D) and oxygen atom in C = O for Y = electron-donating, while a concerted mechanism with an enolate-like TS in which the nucleophile attacks the ${\alpha}$-carbon for Y = electronwithdrawing substituents.

• 한국식품조리과학회지
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• 제32권2호
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• pp.147-156
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• 2016

Purpose: The purpose of this study was to investigate antioxidant activities and quality characteristics of the steamed roll added Ligularia fischeri (Ledeb.)Turcz. powder. Methods: Steamed roll were prepared with different amounts (0%, 0.5%, 1%, 1.5%, 2% to the flour quantity) of Ligularia fischeri powder. Results: As a result of measuring the normal component and the sugar content of the steamed roll added with Ligularia fischeri powder showed a tendency to increase as the added amount more significant increase (p<0.001). The pH of steamed roll significantly decreased with fermentation time (p<0.001) after again appeared a tendency to increased (p<0.001). The moisture of steamed roll were measured by significantly decreased as Ligularia fischeri powder content increased (p<0.001).The results of color value, L(lightness)and a(redness)values decreased with b (yellowness) increasing concentration of Ligularia fischeri powder (p<0.001). In texture analysis, gumminess, adhesiveness, cohesiveness, springiness decreased while chewiness and hardness increased as the amount of increasing concentration of Ligularia fischeri powder (p<0.001). According to the sensory evaluation, appearance, texture, moisture of 0.5% group received the highest score, color, flavor and overall acceptability were showed good results in 1% group (p<0.001). Concolusion: In summary, this study was considered that it can be manufactured as natural functional food that can sensory preference in 1%steamed roll added with Ligularia fischeri powder.

• 대한지역사회영양학회지
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• 제8권6호
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• pp.977-985
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• 2003

This study was done to evaluate the health and nutritional status of female college students in Seoul. The subjects were 63 healthy college students aged 20 to 29 years. Their body composition, dietary intakes, clinical blood indices were investigated. Their body composition was determined by means of a multifreqency bioelectrical impedance analysis. Their dietary intake was determined using 3-day record method and their nutrient intake was analyzed by Computer Aided Nutritional analysis program for professional (CAN-pro). Their hemoglobin, hematocrit, red blood cell (RBC), white blood cell (WBC) and mean corpuscular volume (MCV) were determined by semi-automated microcell counter (F-520). Their plasma total cholesterol, TG, and HDL-cholesterol levels were measured using test kits. All data were statistically analyzed by SAS PC package program. Their average consumption of calcium, iron vitamin A, vitamin B2 and niacin were 63.3%, 65.0%, 85.2%, 89.2% and 95.2% of RDA, respectively. The overall mean values of the hematological indices in the female college students were within the normal range. However anemic subjects with hemoglobin (< 12 g/dl) and hematocrit (<36%) accounted for about 20% of the subjects. The mean levels of total cholesterol, HDL-cholesterol and TG were 188.4mg/dl, 69.9mg/dl and 67.4mg/dl, respectively. The percentages of the subjects with plasma total cholesterol level (> 200mg/dl) and LDL-cholesterol (＞130mg/dl) were about 41% and 30.4%, respectively. The data showed a significantly positive correlation between either body fat (%) or BMI and TG. However. there was a significantly negative correlation between either body fat (%) or BMI and HDL-cholesterol. These overall results suggest that it is necessary for college women to be educated regarding consuming more iron and vitamin C and less fat, in order to prevent iron deficiency anemia and/or cardiovascular diseases in later life.

• 콘크리트학회논문집
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• 제23권1호
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• pp.23-30
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• 2011

이 연구는 콘크리트의 내구성 저하요인인 해수침식 및 동결융해 반복작용을 받은 콘크리트의 성능저하 정도를 실험적으로 고찰하기 위하여 포틀랜드 및 혼합시멘트를 사용하여 콘크리트 공시체를 제조한 후 상대동탄성계수, 압축강도 변화 및 기기분석을 통하여 성능저하 원인을 구명하였다. 동결융해 520싸이클까지의 결과 보통포틀랜드 및 저열포틀랜드시멘트는 75% 이상의 상대동탄성계수와 압축강도가 내황산염포틀랜드시멘트 약 44%의 값을 나타내어 상대적으로 낮은 저항성을 나타내었으며, 고로슬래그미분말을 50% 대체하여 사용한 콘크리트가 혼합시멘트계 콘크리트 중 가장 우수한 동결융해 저항성을 나타내었다. 혼합시멘트계 콘크리트의 해수침식 유 무에 따라 비교한 결과, 고로슬래그미분말 콘크리트의 잠재수경성 촉진으로 동결융해 저항성이 우수하였으나, 실리카퓸을 혼합한 콘크리트는 해수침식에 의한 성능저하가 발생하여 동결융해 저항성이 낮아지는 경향을 나타내었고, 해수침식 및 동결융해 작용을 받은 보통포틀랜드 콘크리트는 동결융해 작용에 의한 쏘마싸이트 피크와 해수침식에 의한 석고 및 프리델 염분 피크가 주로 검출되고, 고로슬래그미분말을 혼합한 콘크리트는 해수침식의 유 무에 상관없이 좋은 결과를 나타내었다.

• Journal of Radiation Protection and Research
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• 제42권3호
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• pp.146-153
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• 2017

Background: Acute radiation syndrome (ARS) primarily refers to damage to the hematopoietic system, myeloid system, and gastrointestinal (GI) system caused by radiation exposure. Such damage progresses to become life-threatening. In particular, as the syndrome develops very rapidly-within several hours from radiation exposure-prompt and accurate diagnosis and treatment are needed, as is further research into appropriate diagnostic and treatment modalities. Materials and Methods: Minipigs, which display human-like properties, underwent whole-body irradiation at 2 or 4 Gy (doses causing hematopoietic ARS) or at higher doses of 7 or 12 Gy. Changes in the blood cells and clinical symptoms were analyzed and we performed a necropsy when the animals succumbed to ARS. Results and Discussion: The minipig irradiated with 2 Gy showed a decrease in white blood cells, including neutrophils, lymphocytes, and platelets in the early stages. However, the blood cell counts gradually increased and returned to normal values. The minipig irradiated with 4 Gy succumbed due to hematopoietic ARS. In contrast, the minipigs irradiated with 7 or 12 Gy exhibited clinical symptoms of combined GI damage and hematopoietic syndrome. Moreover, a characteristic pattern of platelet changes was observed in the 7 and 12 Gy irradiated minipigs. Conclusion: The changes in the platelet count caused by radiation exposure observed in minipigs, which are hematologically and pathohistologically similar to humans, suggest that they can be used as a novel diagnostic criterion.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2008년도 춘계 학술발표회 제20권1호
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• pp.129-132
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• 2008

병렬 전단벽구조의 이상적인 거동을 만족시키기 위한 대안의 하나로 철근콘크리트커 플링보에 전단 성능이 우수한 철골 플레이트를 매립하는 방안이 제시되었다. Lam의 연구에 의하면 플레이트를 보강한 시험체가 기존의 철근 콘크리트 커플링보에 비하여 내진성능이 매우 우수한 것을 제시하고 있다. 철골 플레이트 커플링보는 철골 부재와 철근콘크리트 부재로 구성된 합성구조이다. 따라서 철골 부재는 강구조 설계 기준에 의해 설계하고, 철근콘크리트 부재는 철근콘크리트 설계기 준에 의해 설계하여 중첩시키는 방법으로 설계한다. 그러나 아직까지 합성구조에 대한 설계 기준이 마련되어 있지 않은 이유로 본연구에서는 실무에서 쓰이는 기준식의 평가를 통하여 철골 커플링보의 안전성을 검토하고자 한다. 기존 연구의 데이터를 통계학적 분석방법을 이용하여, ACI 기준식과 BS 기준식을 각각 검증하였다. 분석 결과 철근콘크리트의 전단력과 철골 플레이트의 전단력을 중첩하여 계산하는 철골 플레이트 커플링보에 대한 현재의 실무에서의 설계방법은 기존의 실험결과와 비교하면 적절한 설계방법으로 판단된다.

• International Journal of Concrete Structures and Materials
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• 제11권2호
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• pp.215-228
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• 2017

A new approach for measuring the specific fracture energy of concrete denoted modified disk-shaped compact tension (MDCT) test is presented. The procedure is based on previous ideas regarding the use of compact tension specimens for studying the fracture behavior of concrete but implies significant modifications of the specimen morphology in order to avoid premature failures (such as the breakage of concrete around the pulling load holes). The manufacturing and test performance is improved and simplified, enhancing the reliability of the material characterization. MDCT specimens are particularly suitable when fracture properties of already casted concrete structures are required. To evaluate the applicability of the MDCT test to estimate the size-independent specific fracture energy of concrete ($G_F$),the interaction between the fracture process zone of concrete andthe boundary of theMDCTspecimens at the end of the test is properly analyzed. Further, the experimental results of $G_F$ obtained by MDCT tests for normal- and high-strength self-compacting concrete mixes are compared with those obtained using the well-established three-point bending test. The procedure proposed furnishes promising results, and the $G_F$ values obtained are reliable enough for the specimen size range studied in this work.