MgCl₂溶液內에서 STS 304 HP Stainless Steel 熔接部의 破壞擧動에 對한 硏究

金永奭,丁太權,朴昌彦,洪錫柱,梁仁榮,金基玉,朴煥奎,李茂錫,曺圭宰,鄭在康 조선대학교 생산기술연구소 1983 生産技術硏究 Vol.1983 No.-

This paper is based on an experiment analysing the stress corrosion cracking behaviour of welding specimens compared to that of non-welding specimens of STS 304 HP stainless steel in corrosion solution. As a corrosion condition, stainless steel has been known to be the most fragile in a solution of 42% MgCl₂heated to the boiling point, therefore the experiment was carried out in this condition. The experiment was carried out with argon gas TIG welding specimens and non-welding ones made of stainless steel plates, thickness 2mm, by tensile force. At this time, the tensile force was taken to be the value of the yield strength of the tensile test specimens divided by the safety factor of 3.0 to 3.5, 4.0, 4.5, and 5.0. In this paper, the relations between Time of Initial Crack, Time of Failure, Time of Final Fracture and Crack Propagation Length were investigated and then plotted. Furthermore, the relations between Stress Intensity Factor K proposed by Irwin and the Time of Initial Crack, the Time of Failure, the Time of Final Fracture were calculated and plotted. At the last, all the relations plotted were expressed to normal equations by computer, and the equations were used to analyse the data obtained in the experiment. The conclusions obtained in this study are as follows: 1. Welding materials, compared with non-welding ones, as the Time of Initial Crack, the Time of Failure, and the Time of Final Fracture were generally very fast, appeared to be a phenomenon of unstable brittleness fracture. 2. Non-welding materials, compared with welding ones, as the safety factor was larger or the working stress was smaller, appeared to be a phenomenon that the longer had had greater durability. Therefor, welding materials must be considered enough to be used in heate affected and stress corrosion atmosphere. 3. The normal equations of the Time of Initial Crack and the variation rate to the same Stress Intensity Factor K are as follows: (A) Non-welding T =259702.4-5451.2 K+28.386 K² T = -5451.2+28.386 K (B) Welding T= -332.693+28.043 K-0.211 K² T' =28.043-0.211 K here, T; Time of Initial Crack, T'; Variation Rate of Time of Initial Crack to Stress Intensity Factor K, K ; Stress Intensity Factor.

Superconducting MgB2 Wire Drawing Considering Anisotropic Hardening Behavior and Hydrostatic Effect

Young‑Seok Oh,Ho Won Lee,Kook‑Chae Chung,Duck‑Young Hwang,Seong‑Hoon Kang,Jeong Whan Yoon 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.7

Numerical modeling was conducted to investigate the deformation behavior of powder mixture during multi-pass drawingprocesses for multi-filamentary MgB2wire. A modified Drucker-Prager Cap (DPC) model with an elliptical cap surface usingthe new material characterization method was developed to capture the anisotropic hardening behavior and hydrostatic effectof the powder mixture. A number of uniaxial die compaction, cold isostatic pressing, diametrical compression, and uniaxialcompression tests were conducted using different powder densities to characterize the modified DPC model. A commercialfinite element software ABAQUS with a user subroutine was used to simulate the drawing of the MgB2wire. The densityand area fraction of the powder mixture during the wire-drawing process were verified with experimental results. The differencein packing density at the inner and outer filaments of the MgB2wire was successfully captured by simulation. Inaddition, the effect of the initial packing density on the superconducting properties of MgB2wire was numerically studied. It is shown that the increase in the superconducting area, which results from a high initial packing density, should be moreeffective compared to the increase in the grain connectivity in enhancing the critical current properties for the MgB2wirewhen the final packing density is saturated after a number of drawing processes.

Cystic Medullary Thyroid Carcinoma: A Case of Undergoing Endoscopic Thyroid Lobectomy

Dong Hae Chung,Jae Yeon Seok,Yoo Seung Chung1,Eun Mee Oh1,Jung Won Ryu1,Young Don Lee1 대한갑상선-내분비외과학회 2015 The Koreran journal of Endocrine Surgery Vol.15 No.1

On ultrasonography, medullary thyroid carcinoma (MTC) shows hypoechogenicity, an irregular margin, a predominantly solid composition, and microcalcifications, similar to those observed in papillary thyroid carcinoma (PTC). MTC presenting as a cystic lesion is rare, and endoscopic thyroidectomy can be performed for benign thyroid masses and early stage PTC, however it is inappropriate for MTC regardless of cystic change. The authors report a case of cystic MTC found after endoscopic thyroid lobectomy and provide a review of the literature on this topic.

忠南黑石溪谷 住民의 肺, 肝디스토마 感染率 및 그 中間宿主 調査

金鍾煥,鄭奉晳,金玉千 醫藥係社 1955 綜合 醫學 Vol.12 No.12

Gilbert 증후군에서 열량 제한 시험과 Phenobarbital 자극 시험의 의의(14예)

이헌영,채경훈,정재훈,강윤세,김연수,문희석,박기오,이엄석,김선문,김석현,성재규,이병석,이강욱 충남대학교 의학연구소 2003 충남의대잡지 Vol.30 No.2

Gilbert 증후군은 인구의 7%에서까지 나타날 수 있는 매우 흔한 증후군으로서 비진행성인 양성의 만성적 경과를 치하며, 간질환의 증상과 징후가 없는 경한 비포합형 고빌리루빈혈증이 특징인 일종의 체질적인 증상으로서 혈장 빌리루빈 농도에 대한 사춘기의 영향 때문에 10대와 20대에 자주 진단이 된다. 따라서 임상적인 중요성은 미약하지만 높은 빈도가 예상되는 점에 그 중요성이 부여되어야 할 것이다. 따라서 적정한 임상적 진단법으로 기왕에 소개된 열량제한 시험과 phenobarbital 유도 시험을 시행하고 이들의 진단적 가치를 알아보기 위하여 본 연구를 시행하였다. 1990년 7월부터 1999년 4월까지 충남대학교병원에 내원하여 HBsAg, IgG anti-HBc 및 anti-HCV가 음성이고, 간 초음파 스캔에서 이상이 없으며, 혈청 AST, ALT 및 AP가 정상인 비음주자에서 경한 비포합형 고빌리루빈혈증이 있는 14예의 환자들을 대상으로 ^(99m)Tc-DISID 스캔을 시행하였으며, 기저 치 총빌리루빈 및 포합형 빌리루빈 치를 측정한 다음에 하루에 400Kcal로 48시간동안 제한한 열량 제한 시험을 시행하였고, phenobarbital을 하루 60mg씩 5일간 투여한 후에도 각각 총빌리루빈과 포합형 빌리루빈 치를 검사하여 비포합형을 구하였다. 대상 환자들은 모두 14예로서 남자가 11예(78.6%)였고 여자가 3예(21.4%)여서 3.7:1로 남자에서 많았으며, 20대가 6예(42.9%), 30대가 역시 6예(42.9%) 및 40대가 2예(14.2%)로서 2,30대가 대부분(85.8%)이었다. 열량 제한 시험 후의 총빌리루빈 치, 비포합형 및 포합형 빌리루빈 치들은 평균 각각 5.5±2.7, 4.2±2.3 및 1.3±10mg/dL 로서, 시험 전 치들인 3.0±0.8, 2.2±0.8 및 0.7±0.4mg/dL 보다 유의하게(p=0.001, p=0.001, p=0.023) 상승하였다. 포합형 빌리루빈 치도 유의하게 상승하였으나 비포합형의 상승보다는 훨씬 낮아서 주로 비포합형이 증가하였다. phenobarbital 투여 중 설사가 발생하여 중단한 1예를 제외한 13예에서 열량 제한 시험 후에 상승하였던 총, 비포합형 및 포합형 빌리루빈 치가 phenobarbital 유도 시험후에는 2.0±1.1, 1.5±0.8 및 0.5±0.4mg/dL로서 열량 제한 시험 결과보다 유의하게 낮아졌고(p=0.00, p=0.000, p=0.001), 열량 제한 시험 전의 기초치들인 3.0±0.8, 2.2±0.8 및 0.7±0.4mg.dL 보다도 더욱 낮아졌으며 유의한 차이(p=0.001, p=0.02, p=0.005)를 나타내었다. 14예에서 시행한 ^(99m)-Tc DISIDA 스캔에서 9예(64.3%)가 정상이었고, 5예(35.7%)에서는 심장 및 신장으로의 간외 섭취가 3예였고, 60분까지 소장 배출이 없는 배설 지연 예와 담낭 수축 불량 예가 각각 1예 씩 발견되었다. Phenobarbital 투여시험에서 민감도가 열량제한시험에 비해 더 높았다(92.3%와 50.0%). Gilbert 증후군에서 1일 400 Kcal로 48시간의 열량제한 시험과 1일 60mg의 phenobarbital을 5일간 투여하는 유도 시험은 편리하고 유용한 임상적인 진단법으로 이용할 수 있다고 생각된다. 그러나 열량 제한 시험에서는 증가 기준의 통일이 필요하다고 유추되며 phenobarbital 유도 시험이 민감도가 더 높은 것으로 생각된다. Gilbert's syndrome is very frequent and benign chronic process characterized by mild, intermittent, unconjugated hyperbilirubinemia without any symptom and sign of liver disease. Previously intoduced caloric restriction test and phenobarbital stimulation test as two appropriate clinical tests had been examined and their diagnostic values were reevaluated. Fourteen patients with mild, persistent, unconjugated hyperbilirubinemia were included. Subsequently caloric restriction has been applicated by 400 Kcal/day for 48 hours and phenobarbital has been prescribed by 60 mg/day for 5 days. Therafter serum levels of total and direct bilirubin were measured. Most of the patients were third and fourth decade(85.8%) and male predominant. Each basal serum levels of total, indirect and direct bilirubin were 3.0±0.8, 2.2±0.8 and 0.7±0.4 mg/dL. After caloric restriction test, each levels were increased significantly to 5.5±2.7, 4.2±2.3 and 1.3±1.0 mg/dL(p=0.001, p=0.001, p=0.023). After phenobarbital stimulation test for 13 patients had been practiced, increased levels of each bilirubin after caloric restriction test were decreased significantly to 2.0±1.0, 1.5±0.8 and 0.5±0.4 mg/dL(p=0.000, p=0.000, p=0.001) and these levels were significantly lower than basal levels(p=0.001, p=0.02, p=0.005). The sensitivities of caloric restriction test were 85.7%, 50.0%, and 71.4%, 35.7%(1.0, 1.5 mg increase of total bilirubin and 1.0, 1.5 mg/dL increase of indirect bilirubin). The sensitivities of phenobarbital stimulation test were 93.2% and 92.3% at criteria of 1.5 mg/dL increase of total bilirubin and indirect bilirubin. On the diagnosis of Gilbert syndrome, caloric restriction test and phenobarbital stimulation test are convenient and useful diagnostic tools in clinical face. And also phenobarbital stimulation test has higher sensitivity than caloric restriction test. Furthermore, standardization of bilirubin increment would be necessary in caloric restriction test.

말초신경 손상이 실험적으로 유발된 흰쥐의 척수신경절 및 척수등쪽뿔내 신경세포의형태학적 변화에 관한 연구

이원택,손민균,정경승,이홍석,박경아 대한해부학회 1997 Anatomy & Cell Biology Vol.30 No.5

文化的 側面에서 본 古代中國의 天道思想

鄭錫元 漢陽大學校 人文科學大學 1998 人文論叢 Vol.28 No.-

For a long time mankind has faced the challenge of survival and one way to meet it was to understand the nature and adapt to it. The first historical evidence of Chinese view of nature appears in Eun-sang(殷商) Dynasty. Therefore, understanding the view of nature of people in Eun-sang(殷商) Dynasty is important in understanding the Chinese 'view of nature'(自然觀) in the Old Chinese period. The more important 'view of nature'(自然觀), however, is that of Chu(周) Dynasty which follows Eun-sang(殷商) Dynasty. The 'view of nature'(自然觀) in Chu(周) Dynasty deeply influences philosophy, literature, arts, life, science as well as Chinese national characters of the modern period. Therefore, this study investigates into the Chinese view of nature in Eun-sang(殷商) Dynasty and Chu(周) Dynasty in order to understand how "Chondokwan" (the view of the way of Heaven.天道觀) has affected the 'Chinese national characters in the modern period.

고호모시스테인증과 동반된 소뇌출혈 1예

홍석찬,안재영,조수진,정진상,이광호,홍승철,변홍식 대한신경과학회 1999 대한신경과학회지 Vol.17 No.3

산업장 근로자의 표준체중치

정종학,강복수,김석범,사공준,이정길,한구웅 大韓産業醫學會 1989 대한직업환경의학회지 Vol.1 No.1

산업장 근로자의 건강증진과 노동력보존에 기여할 목적으로 경상북도 구미시에 소재하는 구미공단내의 20-29세 산업장 근로자 10,407명(남자 6,201명. 여자 4,206명)을 대상으로 1985년의 정기 신체 검사 자료로 부터 성별. 연령별 평균신장, 평균체중 및 신장과 체중간의 상관관계와 회귀방정식을 구하고 이들을 이용하여 신장별 표준체중과 이상체중의 범위를 구했으며 신장과 체중으로 BMI를 산출하였다. 20대 근로자의 평균신장은 남자가 168.2±5.61cm였고 여자는 155.9±5.26cm였고 평균체중은 남자가 61.4±6.56kg, 여자는 52.4±6.00kg이었다. 신장과 체중간의 상관계수는 남자의 경우 +0.541이었고 회귀방정식은 Y(체중)=0.637Ⅹ(신장)-44.975였으며 여자는 상관계수가 +0.559였고 회귀방정식은 Y(체중)=0.637 Ⅹ(신장)-46.898 이었다. 신장별 표준체중은 신장이 155cm일때에 남녀 각각 53.0kg, 51.8kg 이었으며 165 cm 일때는 59.3kg, 58.2kg이었고 175cm일때에 65.6kg, 64.6kg이었고, 정상체중의 범위는 신장이 155cm일때에 남자는 47.5-58.5kg, 여자는 46.9-56.8kg, 165cm일때는 남자는 53.8-64.8kg, 여자는 53.2-63.2kg, 175cm일때에 남자는 60.1-72.1kg, 여자는 59.6-69.6kg으로 평가되었으며, 비만은 신장이 155cm 일때에 남자는 64.1kg이상, 여자는 61.8kg이상, 165cm일때는 남자는 70.3kg이상, 여자는 68.2kg이상, 175cm일때에 남자는 76.7kg이상, 여자는 74.5kg 이상으로 평가되었다. 성별. 연령별 BMI는 남자가 21.7±1.95였고 여자는 21.6±2.05였고 Garrow의 BMI 분류방식에 따른 desirable range에 속하는 근로자는 남자가 75.9%였고, 여자는 71.3%였다. To contribute to promotion of health and preservation of labor power of Korean laborers, the body height and body weight were measured for 10,407 workers(6,201 male, 4,206 female) in the age group of 20-29, engaged in manufactures in the Gumi industrial complex, Gumi city, Kyungpook province. The above data were extracted from the 1985 periodic examination chart for calculation of the mean body weight, mean body height, correlation coefficient and regression equation between weight and height, standard body weight, body mass index(BMI) and distribution of laborers within Garrow's classification of BMI by age and sex group. Mean body height of 20-29 age group was 168.2±5.61 cm for male and 155.9±5.26 cm for female. Mean body weight of 20-29 age group was 61.4±6.56 kg for male and 52.4±6.00 kg for female. Correlation coefficient and regression equation of 20-29 age group were +0.541 and Y(Wt)=0.632X(Ht)-44.975 for male and +0.559 and Y(Wt)=0.637X(Ht)-46.898 for female. Standard body weight of 20-29 age group was 53.0 kg at 155 cm, 59.3 kg at 165 cm, 65.6 kg at 175 cm for male and 51.8 kg at 155 cm, 58.2 kg at 165 cm at 64.6 kg at 175 cm for female. Range of normal body weight of 20-29 age group was 47.5-58.5 kg at 155 cm, 53.8-64.8 kg at 165 cm, 60.1-72.1 kg at 175 cm for male and 46.9-56.8 kg at 155cm, 53.2-63.2 kg at 165 cm, 59.6-69.6 kg at 175 cm for female. Range of obesity of 20-29 age group was 64.1 kg and over at 155 cm, 70.3 kg and over at 165 cm, 76.7 kg and over at 175 cm for male and 61.8 kg and over at 155 cm, 68.2 kg and over at 165 cm, 74.5 kg and over at 175 cm for female. Body mass index(kg/m²) of 20-29 age group was 21.7±1.95 for male and 21.6±2.05 for female, 75.9% of male laborers and 71.3% of famale counterparts fall in the desirable range of BMI by Garrow's classification.

고속응답, 저소비전력형 마이크로 유량센서의 제작과 그 특성

정귀상,홍석우 東西大學校 2000 동서논문집 Vol.6 No.-

This paper describes on the fabrication and characteristics of hot-film type micro-flowsensors integrated with Pt-RTD's and micro-heaters on the Si substrate, in which MgO thin-films were used as medium lager in order to improve adhesion of Pt thin-films to SiO2 layer. The MgO layer improved adhesion of Pt thin-films to SiO2 layer without any chemical reactions to Pt thin-films under high annealing temperatures. In investigating output characteristics of the fabricated micro-flowsensors, the output voltages increased as gas flow rate and its conductivity increased due to increase of heat-loss from sensor to external. Output voltage was 82 mV at N2 flow rate of 2000 sccm/min, heating power of 1.2W.