Effect of Impact Velocity on Interface Characteristics of HT‑9 Steel Joints Fabricated by Magnetic Pulse Welding

Jun‑Woo Song,Jin‑Ju Park,Gyoung‑Ja Lee,Min‑Ku Lee,Kyu‑Hyun Park,Soon‑Jik Hong,Jung Gu Lee 대한금속·재료학회 2020 METALS AND MATERIALS International Vol.26 No.3

The weldability window in magnetic pulse welding (MPW) is proposed for the end-closure joining of HT-9 steel tubularworkpieces. Based on both theoretical and experimental investigations, the impact velocity of the flyer tube at the momentof collision had a dominant effect on the bonding characteristics of the resultant joints and the optimal impact velocity wasestimated to be in the range of 265–290 m/s in this alloy system. Under the optimal process conditions, no leak was detectedduring helium leak testing. Moreover, the integrity of the joint interface was preserved until the tube section ruptured duringinternal pressure burst testing. For HT-9 steel, the ductile δ-ferrite phase produced by the localized interfacial melting duringMPW acted as an effective obstacle to crack propagation, thereby enhancing the fracture resistance of the joint interface. Allof the results demonstrated the high integrity and durability of the HT-9 steel tube assembly fabricated by the MPW process.

슬래그계 카올린모르타르의 에트링가이트 생성과 물성에 미치는 무수석고의 영향

송태웅,김준우 경남대학교 신소재연구소 1999 論文集 Vol.11 No.-

고로슬래그를 주성분으로 하는 카올린모르타르용 결합재에 에트링가이트계 자극제로서 무수석고를 사용할 때 그 첨가량이 에트링가이트의 생성과 모르타르의 초기 물성에 미치는 영향을 관찰하였다. 무수석고의 첨가는 에트링가이트와 생성과 모르타르의 초기강도 발현에 매우 효과적이었으나 적정량 이상 첨가하면 에트링가이트의 성장이 미약하고 미반응 CaSO4가 잔존하여 다시 강도가 하락하였다. The effects of ettringite-forming anhydrite on the early properties of the slag-based kaolin mortars were studied. The addition of anhydrite, within certain amounts, was very effective for the formation of ettringite. hydraulic reactivity and the early strength of the mortars. The strength of the mortar, however, was decreased by the excessive anhydrite which is remaining without reaction and suppressing the growth of the ettringite crystals.

흰쥐에서 음경발기 평가의 척도로서 음경해면체내압측정술 확립

송윤섭,김용준,이광우,김준모,문기혁,박영호,민영기,유형균,김형건 순천향의학연구소 2001 Journal of Soonchunhyang Medical Science Vol.7 No.1

Purpose: Because studies about the control of penile erection at the entral nervous system was dependent on the animal experiments, establishment of measuring penile erection is important to evaluate the effects changes at the central nervous system on the penile erection. Intracavernous pressure measurement in rats has been introduced as a suitable index for the evaluation of penile erection but this method is invasive and technically difficult. So, we established the intracavernous pressure measurement in rats as the experimental index for penile erection. Materials and Methods: 42 male adult Sprague-Dawley rats (250-300gm) were divided to saline or papaverine treated group. Rats were placed on a heating table to maintain their body temparature and anesthetized with 50mg/kg of pentobarbital sodium by intraperitoneal injection. A cannula was inserted to the left carotid artery to measure systemic blood pressure. Saline (0.05, 0.1ml), papaverine(0.05, 0.1, 0.25, 0.5, 1.0, 2.0mg) were injected intracavernously via 26 guage needle filled with saline or papaverine which connected to pressure transducer and polygraph was inserted into the corpus cavernosum on one side to inject the drug and to measure intracavernous presure. Results: Properly executed insertion and intracavernous administration produced a instantaneous but transient rise in intracavernous pressure that substantially stabilized and maintained at 5.4±0.4mmHg. Intracavernous pressure and duration of penile blood flow following intracavernous injection of papaverine are increased comared to those of saline. Conclusions: Monitoring intracavernous pressure in rats represents a suitable index for the evaluation of penile erection in small laboratory animals.

기저질환이 없는 사람에서 발생한 Campylobacter fetus에 의한 재발성 심내막염 1예

전재범,정진원,김성혜,송문희,오형철,안성기,최상호,김남중,김양수,우준희,류지소 대한감염학회 2004 감염과 화학요법 Vol.36 No.6

C. fetus 심내막염은 드물게 발생하는 질환으로 주로 면역능이 저하된 환자에서 발병하고 대동맥판을 침범하는 경우가 많으며 적절한 치료가 되지 않을 경우 치사율이 높다. 저자들은 기저질환이 없던 69세 남자에서 C. fetus 심내막염을 경험하였기에 문헌고찰과 함께 보고하는 바이다. 환자는 발열로 내원하여 시행한 혈액배양 검사상 C. fetus가 동정되었고 경식도 초음파 검사상 삼첨판에 증식증이 발견되어 심내막염 진단하에 ceftriaxone에 이어 meropenem으로 총 4주간 항생제를 투여받고 호전되었다가 한달 후 다시 재발하였고 판막부전 소견 진행하여 삼첨판 치환술을 시행받고 전신상태 호전되어 퇴원하였다. Campylobacter fetus is a rare cause of endocarditis. To date, only about 30 cases of C. fetus endocarditis have been reported mainly in the elderly with chronic underlying illnesses. Most cases showed tendency to involve aortic valve. This report describes a case of native tricuspid valve infective endocarditis in a 69-year-old man without any underlying disease. Despite adequate antibiotic therapy for 4-weeks, endocarditis recurred and leading to surgical valve replacement.

병식 평가 척도-한국판(SUMD-K)의 신뢰도와 타당도 검증

송지영,김기태,이서경,김용희,노준호,김종우,장환일,반건호,강원섭 大韓神經精神醫學會 2006 신경정신의학 Vol.45 No.4

Objectives : This study was conducted to evaluate the reliability and the validity of the Korean version of the Scale to Assessment Unawareness of Mental Disorder (SUMD-K). Methods : The subjects were 55 schizophrenic patients between ages of 26 and 58 who were recruited from the psychiatric unit of the university hospital and the out-patient clinic. The SUMD-K and insight scale of PANSS were applied to the patients. Results : The range of inter-rater (Spearman's rho) of the general items of SUMD-K were .97-.98 on the current illness and .58-.98 on the past illness. The correlation coefficient between the sum and the general items of the SUMD-K showed high scores. The concurrent validity between SUMD-K and insight item of PANSS was high (scores between .59-.96). However,the reliability and the validity of the attribution items of symptoms showed low scores compared to the current symptoms. Conclusion : The SUMD-K was confirmed in its reliability and validity. It can be a useful clinician-rating scale for evaluating insight in schizophrenic patients as well as patients with other neuropsychiatric conditions.

제주도 토양의 감귤나무(Citrus unshiu Marc.)에서 ^137Cs의 전이

강태우,박원표,송성준,유장걸 제주대학교 방사능이용연구소 2001 연구보고 Vol.15 No.-

본 연구는 제주도 토양 감귤나무에서 ^137Cs의 전이를 조사하기 위하여 유기물 함량이 서로 다른 제주도내 6개 지역의 감귤원에서 채취한 감귤과 토양시료를 감마분광계로 ^137Cs 농도를 측정하였고, 또한 토양화학 특성과의 관계를 조사하였다. 토양 중 ^137Cs 농도는 10.2∼40.0 Bq/kg dry 범위로, 유기물 함량이 높을수록 높은 경향을 보였다. 식물체 중 ^137Cs 농도는 가식부위의 경우는 검출하한치 이하 ∼91.8 mBq/kg·fresh, 잎은 검출하한치 이하 ∼235 mBq/kg·fresh의 범위로 가식부위, 껍질 그리고 잎 순으로 높았다. 토양에서 식물체로의 ^137Cs 전이계수는 잎, 껍질 그리고 가식부위에서 각각 2.15×10^-3∼1.25×10^-2, 7.28×10^-4∼8.13×10^-3 그리고 3.79×10^-4∼3.08×10^-3 범위로 가식부위, 껍질 그리고 잎 순으로 높았다. 토양 pH에 따른 ^137Cs의 전이계수는 서로 상관성이 없었으나, 치환성 K와 토양 유기물 함량이 높을수록 전이계수는 낮아지는 경향이 있었다. 우리 나라 국민 1인당 20 kg의 감귤을 섭취한다고 가정했을 때 이상의 결과로부터 산출된 흡수선량인 0.0048 μSv은 연간 예탁유효 선량 당량 값인 2.48 mSv에 비하여 거의 무시할 수 있는 수준이라고 생각된다. To investigate transfer of ^137Cs in the mandarin trees of Jeju Island, the fruits and leaves as well as the soil samples around each tree were collected from 6 mandarin orchards with different organic matter content. ^137Cs concentration was measured by HPGe γ-ray spectrometry, the relationship between the transfer values and the soil chemical properties was investigated. ^137Cs concentration in soil was in the range of 10.2~40.0 Bq/kg·dry and increased with increasing organic matter content. ^137Cs concentrations in each part of plant were in the range of MDA(minimum detectable activity)~46.8 mBq/kg·fresh(fruit), MDA~91.8 mBq/kg·fresh(peel) and MDA~235 mBq/kg·fresh(leaf), respectively. The distribution of ^137Cs in trees was showed as the following order; fruit<peel<leaf. Transfer factors of ^137Cs from soil to tree were in the range of 2.68×10^-3~1.02×10^-2, 9.07×10^-4~4.03×10^-3 and 4.73×10^-4 ~ 2.04×10^-3 for leaf, peel and fruit, respectively. The transfer factors were as the following order; fruit<peel<leaf. The transfer factors of ^137Cs from soil to tree were not affected by soil pH, but decreased at the high concentration of exchangeable K and organic matter.

마이크로 팩토리 물류이송용 평면모터

이창우,송준엽,하태호,정영상 한국공작기계학회 2007 한국공작기계학회 추계학술대회논문집 Vol.2007 No.-

The micro factory of size is so small that consuming power is reduced and also manufacturing line could be easily reconfigurable. The micro factory is required automation to satisfy high productivity. It is one of the big problems to convey goods, In case of automated reconfigurable micro factory. Planar motor that can perform linear motion in XY direction is one of solution that solves this problem. But conventional planar motor using a magnetic force has a disadvantage that planar motor base is permanent magnet. In this paper we consider new type of a planar motor based on principle of ultrasonic waves using PZT.

다발성 대장암 간전이 환자의 간절제를 위한 새로운 시도

주종우,김형철,임철완,신응진,조규석,유기원,송옥평,홍대식,박성진,조준희,이혜경,김희경,권계원,고은석 순천향의학연구소;Soonchunhyang Medical Research Institute 2004 Journal of Soonchunhyang Medical Science Vol.10 No.2

Multiple bilobar liver matastases (MBLM) are the main cause of low resectability in the colon cancer liver metastases. The authors experienced one case of initially non-resectable colon cancer liver metastases. He was curatively and safely treated with a two-stage hepatectomy using the new method of future remnant liver volume growing. A 54-year-old man was referred to our department with the sigmoid colon cancer combined with MBLM, which were checked in two small metastatic lesions in the left lobe and five large sized lesions in the right lobe in the computed tomogram (CT). A laparoscopic assisted anterior resection was primarily performed. We performed the 1^(st) stage hepatectomy 3 weeks after the colon resection. Intra-operative Ultrasonogram (US) found 9 small superficial metastatic lesions in the left lobe. All that lesions were completely removed by non-anatomical wedge resection. An occlusion ballon catheter was placed in the right portal vein through a small branch of the inferior mesenteric vein at that time. The future remnant liver volume was sufficiently increased 3 weeks after the 1^(st) hepatectomy. A right hepatectomy was safely performed 22 days after the 1^(st) hepatectomy. The patient received a regional chemotherapy (interleukin2 based immuno-chemotherapy through hepatic artery) for 4 months, then received 9 cycles of systemic chemotherapy (biweekly Oxaliplation, leucovorin, plus 5-fluorouracil) without any recurrence evidence.

구순 구개열 환자의 성장후 측모형태에 관한 두부계측방사선학적 연구

장익준,손우일,송재철,진병로 영남대학교 기초/임상의학연구소 2001 Yeungnam University Journal of Medicine Vol.18 No.1

Background: Cleft lip and palate deformity have unknown patterns of maxillofacial growth and development. The maxillofacial growth can be affected either by congenital or environmental factors such as infection and trauma. Surgical repair of cleft lip and palate may interfere the subsequent growth and development of maxillofacial region. The purpose of this study is to evaluate the characteristics of maxillofacial growth patterns in adult cleft lip and palate patients. Materials and Methods: The material for this study consisted of 17 adult male patients with cleft lip and palate. Cephalometric tracing and measurements were done by one investigator. The relationship between 17 cleft lip and palate patients and Korean norms were evaluated statistically Results: There were statistically differences in Na. perpendicular to point A, SNA angle, effective maxillary length, maxillofacial differencial, Wit's appraisal and upper incisor to point A(p<0.01). Pogonion to Na. perpendicular also statistically differed(p<0.05). Other measurements didn't statistically differ. Conclusion: It was evident that in adult cleft lip and palate patients, maxilla was retruded and short. Careful cleft lip and palate repair and treatment are recommended for facilitating normal growth of maxilla.

TCP 트래픽의 성능 측정

최우철,송화선,정영준 강원대학교 정보통신연구소 2003 정보통신논문지 Vol.7 No.-

The performance evaluation of Internet traffics has been performed by factors such as RTT and packet loss. This individual evaluation method has some difficulties in determining service quality due to interoperations between those factors. This paper presents a hybrid performance evaluation formula for TCP traffics, which uses both RTT and packet loss. The formula has been defined by an interpretation model, which is derived from a TCP throughtput rate in congestion environment and a packet retransmission mechanism. The proposed formula has been applied to a data set collected from the KREN performance measure, and then has been shown to easily determine TCP performance variations. Thus, the proposed scheme can be used for a SLA monitoring system.