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.

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.

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

돼지의 離乳後 形質에 미치는 品種性 및 環境要因의 效果

鄭興又,朴英一,徐康錫 서울대학교농과대학농업개발연구소 1989 서울대농학연구지 Vol.14 No.1

This study was conducted to investigate the effect of breed, sex, year of birth, month of birth, litter size and parity of sow on certain postweaning traits in swine. The data for this study were obtained from 5,386 heads of Duroc, Landrace and Yorkshire boars and gilts tested at a swine breeding farm in Icheon, Kyunggi-Do from August, 1982 to August, 1987. The results obtained in this study are as follow: 1. The least-squares overall means of the traits studied were 0.777±0.002㎏ for average daily gain, 158.7±0.28 days for age at 90㎏, 1.833±0.008㎝ for backfat thickness, 112.2±0.13㎝ for body length and 63.7±0.05㎝ for wither's height, respectively. 2. Among the three breeds compared, the Duroc had the highest average daily gain and reached 90㎏ at an earliest age. The Landrace had the thinnest backfat and longest body length. In wither's height the Duroc was the highest. 3. Males had higher average daily gain, reached 90㎏ at an earlier, age, had thinner backfat, longer body length and higher wither's height than females. 4. Year of birth and month of birth had significant effects on all of the postweaning traits studied. The pigs born in June, July and August had comparatively higher average daily gain and earlier age at 90㎏ than those born in other months. The pigs born in October had the thinnest backfat. 5. the effect of litter size was significant for age at 90㎏ and backfat thickness, but was not significant for average daily gain, body length and wither's hight. The pigs in litter sizes of 5 to 7 reached 90㎏ at an earliest age, and those in litter size of 12 or more reached 90㎏ at a latest age. Backfat was thinnest in the litter size of 4 or less and was thickest in the litter size of 12 or more. 6. The pigs in 2nd 3rd parities had the highest average daily gain and reached 90㎏ at an earliest age, and those in 5th parity was the most inferior in the two traits. Backfat was thinnest in the 1st parity and was thickest in the 5th parity.

외이도 손상을 동반한 외상성 악관절증의 치험례

정 훈,고석호 대한 두개하악장애학회 1994 대한두개하악장애학회지 Vol.6 No.1

Sometimes, traumatic temporomandibular joint arthrosis resulted from trauma on the temporomandibular joint area cause hearing impairment, tinnitus and foreign body sensation as well as frequent symptoms of temporomandibular joint arthrosis-mouth opening limitation, pain and click. In the case of temporomandibular joint arthrosis, we think that we must evaluate the form and positional abnormality of mandibular condyle, articular eminence and mandibular fossa in relation to articular disc and the injury of the mandibular fossa and external auditory meatus caused by force moving postero-superiorly through mandibular condyle at the same time of a blow to the chin. Therefore, we are presenting the result and a review of literatures since we have experienced the case of traumatic temporomandibular joint arthrosis accompaing with external auditory meatus injury.

한우산업의 발전을 위한 사육농가에 관한 조사 연구

정재록,이인호,김석은 公州大學校 産業開發硏究所 1998 産業開發硏究 Vol.6 No.-

This survey was carried out to investigate and analyse the current status of feeding for development of Hanwoo industry. 50 total of farm households were surveyed in Chungnam province including Kyonggi, Chonbuk, Chungbuk and Kangwon province. The results obtained were as follows; 1. Of 50 farm households, the households below 10 years at feeding carrier were 56.0 percentage928 households), those over 21 years-carrier were 8.0 percentage(4 house-holds). 2. In patterns of agricultural management, 23 households were additional farming(46.0%), 11 households were special and professional occupation(22.0%), and 8 households were others and complex farming patterns(16.0%). 3. At beginning first farming, most managers started at the management pattern of calves, heifers and mature cattle, 24 households had been started at the small scale of the farming below 10 calves(48.0%), and then also others started at pattern below 10 heifers and 10 mature cattle. 4. Roughages at feeding Hanwoo were mainly rice straws at most farms, the average daily gain was under 1kg in 29 households(58.0%), marketing weight was 560kg in 29 households (58.0%), and were over 601kg in 7 households(14.0%). 5. The number of managers composed of husband and wife were 44.0 percentage(22 households), and then only one person was 38.0 percentage(19 households). 6. 22 households purchased cattle for rearing through the selection of body type, body weight, and body length(44.0%), 4 households purchased without consideration of appearance and body weight, 21 and 16 households purchased these cattle at market(42.0%) and at different farm area(32.0%), respectively. On the other hand, 9 households were raising through production at their farms. 7. The affairs and results of management had been recorded in 28 households only on important concerns and contents(56.0%). On sides of getting management information, 18 households depended on mass media(36.0%), 24 households depended on professional magazines concerned(48.0%), and no household was in case of getting information through specially concerned books and educational computers.

퍼지 PID제어기를 이용한 전력계통의 안정화장치에 관한 연구

정형환,주석민,김상효 동아대학교 공과대학부설 생산기술연구소 1996 生産技術硏究所硏究論文集 Vol.1 No.2

This paper presents a design techique of the fuzzy PID controller for power system stabilization. PID parameters of the fuzzy PID controller were self-tuned by the fuzzy inference algorithm. The proposed controller compare with conventional power system stabilizer(PSS) under various of initial vlue of rotor angle deviation and load condition. The eslated simulation results show that the proposed controller was more excellent control characteristics than conventional PSS in transient-state and steady-state response.