Plastic η factor considering strength mismatch and crack location in narrow gap weldments

Koo, J.M.,Huh, Y.,Seok, C.S. North-Holland Pub. Co 2012 Nuclear engineering and design Vol.247 No.-

The fracture toughness for LBB analysis of piping is generally determined in terms of the J-integral according to ASTM E1820. The J-integral consists in the elastic component J<SUB>el</SUB> and the plastic part J<SUB>pl</SUB>. Experimental evaluation of J<SUB>pl</SUB> requires the plastic η factor. The J-integral evaluation by ASTM method was developed, however, essentially for homogeneous material. The fracture toughness of a strength mismatch weld evaluated as per ASTM method can, thus, differ from its actual value. In this study, the plastic η factors of similar as well as dissimilar metal narrow gap weld are suggested considering the influence of weld strength mismatch, weld width, and crack location. The proposed plastic η factors are compared with detailed finite element results. Few fracture tests were performed to quantify the influence of weld strength mismatch on fracture toughness of low alloy steels using C(T) specimens.

컴퓨터제어에 의한 자동초음파 탐상장치에 관한 연구

허형,박치승,홍순신,박종현 韓國非破壞檢査學會 1989 한국비파괴검사학회지 Vol.9 No.1

Since the nuclear power plants in Korea have been operated in 1979, the nondestructive testing(NDT) of pressure vessels and/or piping welds plays an important role for maintaining the safety and integrity of the plants. Ultrasonic method is superior to the other NDT method in the viewpoint of the detectability of small flaw and accuracy to determine the locations, sizes, orientations, and shapes. As the service time of the nuclear power plants is increased, the radiation level from the components is getting higher. In order to get more quantitative and reliable results and secure the inspector from the exposure to high radiation level, automation of the ultrasonic equipments has been one of the important research and development(R & D) subject. In this research, it was attempted to visualize the shape of flaws presented inside the specimen using a Modified C-Scan technique. In order to develope Modified C-Scan technique, an automatic ultrasonic scanner and a module to control the scanner were designed and fabricated. IBM-PC/XT was interfaced to the module to control the scanner. Analog signals from the SONIC MARK II were digitized by Analog-Digital Converter(ADC 0800) for Modified C-Scan display. A computer program has been developed and has capability of automatic data acquisition and processing from the digital data, which consist of maximum amplitudes in each gate range and location. The data from Modified C-Scan results was compared with shape from artificial defects using the developed system. Focal length of focused transducer was measured. The automatic ultrasonic equipment developed through this study is essential for more accurate, reliable, and repeatable ultrasonic experiments. If the scanner are modified to meet to appropriate purpose, it can be applied to automation of ultrasonic examination of nuclear power plants and helpful to the research on ultrasonic characterization of the materials.

Practical Application of Ethanedinitrile(C₂N₂) to Control Pine Wilt Nematode and Its Vector

J. K. Son,W. Huh,C. G. Park,S. Y. Kim,C. S. Cho,B. H. Lee 한국농약과학회 2007 한국농약과학회 학술발표대회 논문집 Vol.- No.-

Flexible transparent electrodes made of core-shell-structured carbon/metal hybrid nanofiber mesh films fabricated via electrospinning and electroplating

Huh, J.W.,Jeon, H.J.,Ahn, C.W. ELSEVIER 2017 CURRENT APPLIED PHYSICS Vol.17 No.11

<P>The development of practical flexible transparent electrodes is one of the major core technology fields for future nanoscale optoelectronics. Despite the many efforts to replace the indium tin oxide (ITO) electrode, preparing practical alternatives that satisfy the essential requirements of flexible transparent electrodes remains a challenge. In this work, core-shell-structured carbon/metal hybrid mesh (CS-CMHM) films, comprised of a metal layer coated onto conductive carbon nanofiber network structures, were fabricated using electrospinning and electroplating and demonstrated potential for use as flexible transparent electrodes. In contrast to previously described techniques that use conventional polymer fibers as sacrificial structures, the conductive carbon nanofibers used in the current technique that we developed provided bi-functionality: they formed conductive core channels and artificial supports of the metal structures. The CS-CMHM films displayed superior optoelectrical, mechanical, and thermal properties: they transmitted similar to 91% of visible light, showed a low sheet resistance of similar to 2.7 Omega/sq, and displayed excellent mechanical stability even after 10000 cycles of bending the films to a radius of 5 mm; also, applying a voltage of only 3 V to a transparent heater based on CS-CMHM films resulted in the temperature of the film surface increasing very rapidly in the first 20 s, and soon thereafter reaching similar to 280 degrees C. Based on these results, we believe that the use of CS-CMHM films and the process we developed to fabricate them open up great opportunities for high-performance flexible transparent electronics. (C) 2017 Elsevier B.V. All rights reserved.</P>

한국 성인에서 비알콜성 지방간의 중증도에 따른 대사이상의 특징

김형진,김대중,김수경,김세화,이유미,안철우,차봉수,송영득,임승길,김경래,이현철,허갑범 대한내분비학회 2002 Endocrinology and metabolism Vol.17 No.4

연구배경: 30세 이상의 성인 한국인에서 지방간의 중증도와 대사증후군의 여러 요소들 (특히 인슐린저항성 및 중심성비만)과의 관련성을 분석하고자 하였다. 방법: 대상자는 2001년 4월부터 6월까지 건강검진센터를 방문한 사람들 중 만성 바이러스성 간염이나 일주일에 2회 이상 음주력이 있는 사람들을 제외한 1074명 (남자 502, 여자 572)에서 문진, 신체검사, 채혈 그리고 복부초음파를 시행하였다. 결과: 1074명중 522명에서 지방간이 양성이어서 양성율은 49%였으며 남성은 여성에 비해 높은 유병률을 보였다. (57 vs 42%, p<0.05). 당뇨병, 비만 그리고 이상지질증을 가지지 않은 사람들에서 비알콜성 지방간의 유병률은 20%였다. 지방간이 양성인 522명중 218명은 경도, 273명은 중등도, 31명은 중증의 지방간 소견을 보였다. 체질량지수, 허리둘레, 체지방률, 수축기혈압, aspartate aminotransferase, alanine aminotransferase, 총콜레스테롤, 중성지방, 그리고 총콜레스테롤/고밀도지단백 비는 지방간의 중증도에 따라 의미있게 증가하는 양상을 보였다(p<0.05). 다중회귀분석을 시행하였을 때 지방간의 중증도를 잘 반영하는 인자로는 허리둘레, alanine aminotransferase, HONA_IR, 총콜레스테롤/고밀도지단백비, aspartate aminotransferase, 그리고 수축기혈압의 순서로 나타났다. 공복혈당장애, 고혈압 및 인슐린저항성은 지방간을 가진 군에서 대조군보다 의미있게 높은 빈도를 보였을 뿐만 아니라 지방간의 중증도에 따라 차이를 보였다(p<0.05). 인슐린저항성은 심한 지방간에 비교위험도가 14.7(CI; 6.8∼32.0), 중등도의 지방간에서 6.9(CI; 4.6∼10.3), 경도의 지방간에서 5.7(CI; 3.6∼8.8)이었으며 HOMA_IR의 상위 1/4을 인슐린저항성이 있는 군으로 정의하였을 때 각군에 인슐리저항성을 가진 비율은 7.6, 32.0, 36.0, 그리고 55%였다(p<0.05). 지방간의 중증도에 따른 비알콜성 지방간염의 고위험군 비율은 각각 5.0, 21.6, 27.8, 그리고 58.1%였다(p<0.05). 결론: 우리나라의 비알콜성 지방간의 빈도는 서구인에 비해 높은 것으로 나타났다. 또한 비알콜성 지방간이 있을 경우 대사증후군과 관련된 여러인자들(특히 인슐린저항성과 중심성비만)과 비알콜성 지방간염의 위험이 현저히 증가하며 초음파의 중증도 분류에 따라 비례하였다. Background: We evaluated the frequency of non-alcoholic fatty liver disease, and the associations between the metabolic abnormalities and severity of non-alcoholic fatty liver disease in Korean adults using ultrasonography. Methods: We examined 1074 Korean adults above the age of 30 years, comprising of 502 men and 572 women, participating in medical check-ups at the Health Promotion Center. Hepatitis B and C serologies were negative, and the average weekly alcohol intake was ≤ 2 standard drinks. A standard interview, physical exam and biochemical study, were conducted, and an experienced operator carried out ultrasound liver studies. Results: 522 of the subjects had non-alcoholic fatty liver disease, and the remaining 552 did not. The frequency in the men was higher than that in the women (57 vs 42%, p<0.05). The frequency of non-alcoholic fatty liver disease in the subjects without diabetes, obesity or dyslipidemia was 20%. We classified subjects into 4 groups: the controls (n=552) and those with mild (n=218), moderate (n=273) or severe fatty liver disease (n=31), according to their ultrasonographic findings. BMI, waist circumference, body fat, systolic blood pressure, aspartate aminotransferase, alanine aminotransferase, total cholesterol, triglyceride, the total-to HDL-cholesterol ratio, impaired fasting glucose, hypertension and insulin resistance, were all significantly increase with the increased severity of non-alcoholic fatty liver disease (p<0.05). Following the multiple regression analyses, waist, alanine, aminotransferase, HOMAIR, the total- to HDL-cholesterol ratio, aspartate aminotransferase and systolic blood pressure, were all associated with the severity of non-alcoholic fatty liver disease. Odd ratios of insulin resistance in the mild, moderate and severe non-alcoholic fatty liver disease were 14.7 (CI: 6.8∼32.0), 6.9 (CI: 4.6∼10.3) and 5.7 (CI 3.6∼8.8), respectively. The percentages of subjects with insulin resistance in each group were 7.6, 32.0, 36.0 and 55.0% (p<0.05), respectively. The percentages of subjects with risk of non-alcoholic steatohepatits in each groups were 5.0, 21.6, 27.8 and 581% (p<0.05) respectively. Conclusion: The frequency of non-alcoholic fatty liver disease was relatively high in Korean adults. Proportional differences in metabolic abnormalities, relation to the severity of non-alcoholic fatty liver disease, were found by ultrasonography (J Kor Soc Endocrinol 17:514∼525, 2002).

한국인에서의 비전형적 당뇨병

이은직(Eun J . Lee),김도영(Doe Y . Kim),허갑범(Kap B . Huh),김현만(Hyeon M . Kim),임승길(Sung K . Lim),김경래(Kyung R . Kim),이현철(Hyun C . Lee),김덕회(Duk H . Kim) 대한내과학회 1987 대한내과학회지 Vol.33 No.6

N/A Of 501 Korean diabetics admitted to Severance Hospital, Yonsei University College of Medicine, non-obese non-insulin-dependent diabetes mellitus (NIDDM) comprised 319 cases (63.7%), obese NIDDM 100 cases (19.9%) and insulin-dependent diabetes mellitus (IDDM) 82 cases (16.4%). And in the IDDM group thus collected, juvenile-onset diabetes (JOD) comprised 17 cases (3.4%), youth-onset underweight diabetes (YOUD) 25 cases (5.0%) and maturity-onset underweight diabetes (MOUD) 40 eases (8.0%). The caloire intakes just before the onset of diabetes in YOUD and MOUD patients were found to be 63.1% and 60.9% and the intakes of protein 55.9% and 79.8% of the recommended dietary allowance, respectively. Among JOD, YOUD and MOUD, there were no significant differences in body weight, and fasting blood glucose and HbA1c levels at the time of admission. The basal and peak serum C-peptide levels in YOUD (1.03±0.61ng/ml, 1.59±1.23ng/ml) were slightly higher than those in JOD (0.64±0.30ng/ml, 1.05±0.54ng/ml), but significantly lower than those in MOUD (1.61±0.73ng/ml, 2.65±1.30ng/ml). Between JOD and YOUD, there was no significant difference in family histories (23.5%, 24.0%) or clinical features. However, MOUD turned out to have significantly lower family history (2.5%), no history of diabetic ketoacidosis and more pulmonary tuberculosis than the former 2 groups. Of 29 young diabetics (JOD and YOUD) who were followed-up at OPD, 14 cases (5 JOD and 9 YOUD) were ketosis-resistant. These data suggest that, in Korea which is located in temperate zone, malnutrition-related diabetes mellitus (MRDM) can be mainly classified into 2 groups: The youth-onset one had the characteristics of IDDM with the history of undernutrition and ketosis-resistance, and the maturity-onset one may belong to NIDDM with the higher susceptibility to pulmonary tuberculosis.

Sensitive ''capillary ELISA'' via vapor-phase surface modification

Kim, W.J.,Hyun, S.H.,Cho, H.Y.,Byun, S.,Kim, B.K.,Huh, C.,Chung, K.H.,Kim, Y.J. Elsevier Sequoia 2016 Sensors and actuators. B Chemical Vol.233 No.-

Sensitive ELISA for C-reactive protein (CRP) was performed in a capillary tube based on simple vapor-phase surface chemistry. Amine surfaces were produced in capillary tubes in two different methods using 3-aminopropyltriethoxysilane (APTES) in liquid and vapor phases. Those amine surfaces were tethered with gold nanoparticles (AuNPs) to be characterized by field emission scanning electron microscopy (FE-SEM) resulting in more dense and dispersed AuNP populations from the vapor-phase surface. Feasibility of a miniaturized home-made optical detector for ''capillary ELISA'' was performed by infusing into capillary tubes the colored solutions that had just gone through ELISA on a 96-well plate. The compatibility of the two results obtained from ELISAs on a well-plate and in capillary tubes, confirmed dependability of the miniaturized detector. Finally ''capillary ELISA'' was performed on the home-made detector using anti-CRP immobilized capillary tubes that had been prepared via vapor-phase surface treatment, resulting in detectability of 1.0ng/mL of CRP, which turned out to be around 10 times higher in sensitivity than that of the well-plate ELISA.

直腸癌의 手術後 放射線治療 成績

허승재(S.J.Huh),하성환(S.W.Ha),박찬일(C.I.Pack),최국진(K.J.Choi),김진복(J.P.Kim) 대한방사선종양학회 1984 Radiation Oncology Journal Vol.2 No.2

Surgery remains the mainstay in the management of carcinoma of the rectum. However, local recurrence and systemic metastasis remain the challenge. It appears that post operative radiotherapy has a very definite role in the reduction of local recurrence. Ninty two patients of carcinoma of the rectum after curative surgery received post operative radiotherapy 5,000 rad/5~6weeks to whole pelvis at the Department of Therapeutic Radiology, Seoul National University Hospital between March 1979 and December 1982. Fifty three percent of patients show modified Astler-Coller stage C₂. Actuarial disease free survival rate of rectal cancer was : stage B1,2 75% stage C1 81% stage C₂ 39%, and stage C₃ 20%. Twelve percent shows local recurrence and distant metastasis occurred in 28%. Prognostic sighificance of nodal metastasis is also analysed. Incidence of small bewel obstruction, requiring surgery, is 8%. occurring between 5th month to 12th month after operation. It is suggested that post operative radiotherapy of the rectal cancer following curative surgery has a signifinat role in the reduction of local recurrence.

새로 국내에서 밝혀진 균주(R19)와 전통적 균주를 이용하여 혈청학적으로 진단된 쯔쯔가무시병의 임상상 및 항체반응 양상

이수기,이은경,허충,임병욱,김용림,강재승,이진관,조준탁,박동철,박경현 대한감염학회 1991 감염 Vol.23 No.1

From September to December 1989, eighteen cases of tsutsugamushi disease were diagnosed by indirect immunofluorescent antibody test in Ulsan-Ulchu area. Their clinical features and patterns of antibody response to R. tsutsugamuschi were analyzed. It was most prevailing in female over 30 years old. Most of patients (16 patients) were rural inhabitants. Two patients in urban area had reaped the rice in the rice field at several days before onset of the disease. It occurred between September and November with a peak in October. Chief complaints of patients were febrile sensation with or without chills or headache. All patients had fever and chills. Headache and myalgia were common. In one patient, delirium with visual hallucination was seen. The major physical findings were skin rash (83%), eschr (78%), lymphadenopathy (11%). The skin rash appeared on whole body or on the trunk. The eschar appeared on the chest or abdomen or in the genial region. The antobody titer to R 19 that had been newly isolated strain in Korea was universally high. There often were anemia (31%), leukocytosis (23%). Microscopic hematuria and pyuria were also seen in routine urinalysis. Liver function tests showed eleveted aminotransferases and LDH. There were erythrophagocytic histiocytes in the bone marrows of six patients among the ten patients whose bone marrow had been aspirated. Chloramphenicol had been used in all patients. The mean time to alleviation of fever was 2.5 days. All patients were cured.

Wound healing potential of antibacterial microneedles loaded with green tea extracts

Park, S.Y.,Lee, H.U.,Lee, Y.C.,Kim, G.H.,Park, E.C.,Han, S.H.,Lee, J.G.,Choi, S.,Heo, N.S.,Kim, D.L.,Huh, Y.S.,Lee, J. Elsevier 2014 Materials Science and Engineering C Vol.42 No.-

This study evaluates the utility of an antibacterial microneedle composed of green tea (GT) extract and hyaluronic acid (HA), for the efficient delivery of GT. These microneedles have the potential to be a patient-friendly method for the conventional sustained release of drugs. In this study, a fabrication method using a mold-based technique to produce GT/HA microneedles with a maximum area of ~50mm<SUP>2</SUP> with antibacterial properties was used to manufacture transdermal drug delivery systems. Fourier transform infrared (FTIR) spectrometry was carried out to observe the potential modifications in the microneedles, when incorporated with GT. The degradation rate of GT in GT/HA microneedles was controlled simply by adjusting the HA composition. The effects of different ratios of GT in the HA microneedles were determined by measuring the release properties. In HA microneedles loaded with 70% GT (GT70), a continuous higher release rate was sustained for 72h. The in vitro cytotoxicity assays demonstrated that GT/HA microneedles were not generally cytotoxic to Chinese hamster ovary cells (CHO-K1), human embryonic kidney cells (293T), and mouse muscle cells (C2C12), which were treated for 12 and 24h. Antimicrobial activity of the GT/HA microneedles was demonstrated by ~95% growth reduction of gram negative [Escherichia coli (E. coli), Pseudomonas putida (P. putida), and Salmonella typhimurium (S. typhimurium)] and gram positive bacteria [Staphylococcus aureus (S. Aureus) and Bacillus subtilis (B. subtilis)], with GT70. Furthermore, GT/HA microneedles reduced bacterial growth of infected wound sites in the skin and improved wound healing process of skin in rat model.