연구발표논문초록 ( 전달현상 (Ⅰ) ) : 평형판 내를 흐르는 현탁액에 미치는 자장효과에 관한 수치모사 연구

남재도,이기준 (정) ( Jae Do Nam,Ki Jun Lee ) 한국화학공학회 1986 춘계학술발표회 Vol.- No.-

Si₃N₄ 세라믹스의 균열 치유와 굽힘 강도 특성

남기우(Ki Woo Nam),박승원(Seung Won Park),도재윤(Jae Youn Do),안석환(Seok Hwan Ahn) 대한기계학회 2008 大韓機械學會論文集A Vol.32 No.11

Crack-healing behavior of Si₃N₄ composite ceramics has been studied as functions of heat-treatment temperature and amount of additive SiO₂ colloidal. Results showed that optimum amount of additive SiO₂ colloidal and coating of SiO₂ colloidal on crack could significantly increase the bending strength. The heat-treatment temperature has a profound influence on the extent of crack healing and the degree of strength recovery. The optimum heat-treatment temperature depends on the amount of additive SiO₂ colloidal. Crack healing strength was far the better cracked specimen with SiO₂ colloidal coating on crack surface. After heat treatment at the temperature 1,273 K in air, the crack morphology almost entirely disappeared by scanning prob microscope. At optimum healing temperature 1,273 K, the bending strength with additive SiO₂ colloidal 0.0 wt.% without SiO₂ colloidal coating recovered to the value of the smooth specimens at room temperature for the investigated crack sizes 100 ㎛. But that with SiO₂ colloidal coating increase up to 140 %. The amount of optimum additive SiO₂ colloidal was 1.3 wt.% and crack healed bending strength with SiO₂ colloidal coating increase up to 160 % to smooth specimen of additive SiO₂ colloidal 0.0 wt.%. Crack closure and rebonding of the crack due to oxidation of cracked surfaces were suggested as a dominant healing mechanism operating in Si₃N₄ composite ceramics.

조현병 환자에서 장애에 대한 자기인식과 병식의 연관성

남상훈(Sang-Hun Nam),정도운(Do-Un Jung),김성진(Sung-Jin Kim),문정준(Jung-Joon Moon),전동욱(Dong-Wook Jeon),김연수(Yeon-Sue Kim),신동진(Dong Jin Shin),최현석(Hyeon-Seok Choi),정재훈(Jae-Hoon Jeong) 대한생물치료정신의학회 2020 생물치료정신의학 Vol.26 No.3

Objectives:We aimed to evaluate the relationship between disability self-awareness and insight in patients with schizophrenia. Methods:We enrolled 58 clinically stable patients with schizophrenia. The World Health Organization Disability Assessment Schedule (WHODAS) self-report was used to identify self-awareness of functional ability. The Positive and Negative Syndrome Scale (PANSS), Clinical Global Impression-Schizophrenia Scale (CGI-SCH), and Personal and Social Performance Scale (PSP) were utilized to evaluate clinical symptoms and global function. Whereas Insight Scale for Psychosis (ISP) was applied for insight. Statistical analyses were performed using correlation and linear regression. Results:The WHODAS had a significant correlation with the general psychopathology subscale and total score of PANSS, CGI-SCH, and PSP. Moreover, ISP had a strong correlation with the overall WHODAS score and all domains. In the linear regression analysis, ISP had significant effects on the overall WHODAS score after adjusting for additional variables. Conclusion:Disability self-awareness was significantly correlated with the level of insight in patients with schizophrenia. Clinicians need to consider patients’ insight during the discussion of functional ability.

고성능 열경화성 복합재료

남재도(Jae Do Nam),안규종 한국고분자학회 1995 고분자 과학과 기술 Vol.6 No.5

아크릴계 이온교환섬유를 이용한 수중 크롬(VI) 제거

남아름(Aram Nam),박정안(Jeong-Ann Park),도태구(Taegu Do),최재우(Jae-Woo Choi),최웅수(Ungsu Choi),김경남(Kyung Nam Kim),윤성택(Seong-Taek Yun),이상협(Sanghyup Lee) 大韓環境工學會 2017 대한환경공학회지 Vol.39 No.3

PAN 기반 아크릴계 섬유와 DETA 및 AlCl3・6H2O를 반응시켜 아민기(-NH2)를 가진 이온교환섬유 PADD를 합성하였다. 개발된 섬유상 소재는 FT-IR과 SEM을 이용하여 그 특성을 확인해 보았다. 회분식 실험으로 수행된 PADD를 이용한 크롬제거 실험 결과는 Langmuir 등온흡착모델에 잘 적용되었으며, 이때 계산된 이론적 최대흡착능 (Qmax)은 6.93 mmol/g으로 나타났다. 한편 동적흡착실험은 Lagergren 유사이차속도모델에 잘 부합되었다. PADD의 크롬 흡착능은 pH 2에서 가장 높은 값인 4.11 mmol/g을 나타내었고 pH 변화에 많은 영향을 받는 것으로 확인되었다. 또한, 인산과 비소(V)에 대한 공존이온 실험을 통해 PADD가 크롬에 대한 높은 선택성을 갖고 있음을 확인할 수 있었다. 산-염기 역적정으로 구한 PADD의 총이온교환능 (4.70 mmol/g)을 통해 소재의 선택적 제거 가능성을 검증하였다. Ion exchange fiber, PADD was synthesized by the reaction between PAN based acrylic fiber and DETA with AlCl3・6H2O, and was analyzed by FT-IR and SEM to investigate its characteristics. The experimental results of Cr(VI) removal by PADD were better fitted with Langmuir adsorption isotherm, and the maximum uptake value (Qmax) was calculated to be 6.93 mmol/g. The kinetic data can be well described by Lagergen pseudo-second order rate model. The Cr(VI) adsorption capacity of PADD was 4.11 mmol/g at pH 2, which shows the effect of pH changes on the removal of Cr(VI). The adsorption selectivity of Cr(VI) was higher than phosphate and As(V). Total ion exchange capacity of PADD was 4.70 mmol/g, which was measured by acid-base back titration.

Si₃N₄ 세라믹스의 균열 치유와 굽힘 강도 특성

남기우,박승원,도재윤,안석환,Nam, Ki-Woo,Park, Seung-Won,Do, Jae-Youn,Ahn, Seok-Hwan 대한기계학회 2008 大韓機械學會論文集A Vol.32 No.11

Crack-healing behavior of $Si_3N_4$ composite ceramics has been studied as functions of heat-treatment temperature and amount of additive $SiO_2$ colloidal. Results showed that optimum amount of additive $SiO_2$ colloidal and coating of $SiO_2$ colloidal on crack could significantly increase the bending strength. The heat-treatment temperature has a profound influence on the extent of crack healing and the degree of strength recovery. The optimum heat-treatment temperature depends on the amount of additive $SiO_2$ colloidal. Crack healing strength was far the better cracked specimen with $SiO_2$ colloidal coating on crack surface. After heat treatment at the temperature 1,273 K in air, the crack morphology almost entirely disappeared by scanning prob microscope. At optimum healing temperature 1,273 K, the bending strength with additive $SiO_2$ colloidal 0.0 wt.% without $SiO_2$ colloidal coating recovered to the value of the smooth specimens at room temperature for the investigated crack sizes $100\;{\mu}m$. But that with $SiO_2$ colloidal coating increase up to 140 %. The amount of optimum additive $SiO_2$ colloidal was 1.3 wt.% and crack healed bending strength with $SiO_2$ colloidal coating increase up to 160 % to smooth specimen of additive $SiO_2$ colloidal 0.0 wt.%. Crack closure and rebonding of the crack due to oxidation of cracked surfaces were suggested as a dominant healing mechanism operating in $Si_3N_4$ composite ceramics.

플랜트 승압펌프 재순환 배관 용접부의 용접비드에 의해 발생한 감육결함 분석 및 건전성 평가

남기우(Ki-Woo Nam),안석환(Seok-Hwan Ahn),도재윤(Jae-Yoon Do) 한국해양공학회 2010 韓國海洋工學會誌 Vol.24 No.4

The wall thinning phenomenon of pipes was simulated as metal loss due to erosion and corrosion. Such wall thinning defects in the pipes of power plants are a very important safety consideration, In this study, we analyzed wall thinning dejects thar occurred by weld bead of weld zone of boost pump recirculation. pipe. From the results of the analysis of pipe failures, numerical analysis was performed by Fluent v6.3.26 using the standard k-ε model of the weld bead shape, such as an elliptical or a spherical shape, on the inner wall of the pipe. Using the results obtained, we showed the overlap effect by cavitations corrosion and erosion-corrosion at the bottom of the wall-thinning defect.

요골 원위부 골절에 합병된 장무지 굴곡건 파열 -증례 보고-

김도영 ( Do Young Kim ),서은민 ( Eun Min Seo ),남우동 ( Woo Dong Nam ),박승재 ( Seung Jae Park ),이상수 ( Sang Soo Lee ) 대한골절학회 2011 대한골절학회지 Vol.24 No.2

요골 원위부 골절에 합병된 장무지 신전건 파열은 종종 보고되었으나, 장무지 굴곡건 파열은 보고된 예가 극히 드물다. 저자들은 개방성 창상이 없이 원위부 요골 골절에 합병된 장무지 굴곡건 파열을 1예 치험하였기에 문헌 고찰과 함께 보고하는 바이다. 24세 남자 환자로 전위가 심한 요골 원위부 골절에 대해 도수 정복술을 시행받고, 3일째 무지 지관절 굴곡 운동제한과 전완부의 통증을 호소하였다. 이학적 검진상 장무지 굴곡건 파열이 의심되어 탐색술을 시행하였다. 수술 소견상 요골 골절부위에서 장무지 굴곡건의 파열을 확인할 수 있었고, 건봉합술과 골절부위에 대해 수장부 금속판 고정술을 시행하였다. 요골 원위부 골절 시 신전건뿐만 아니라 굴곡건의 파열도 합병될 가능성을 고려하여, 면밀한 이하적 검진을 시행하여야 하겠고, 특히 도수 정복술을 시행하였을 경우 더욱 세심한 관찰이 필요하다. There are few reported cases of flexor pollicis longus tendon (FPL) rupture complicating a closed distal radius fracture. We report a case of FPL tendon rupture complicating a closed distal radius fracture. A 24-year-old male presented with a severe right wrist pain. He had a closed distal radius fracture that was treated by closed manual reduction. Three days later, he complained forearm pain and limitation of thumb motion. The physical examination revealed loss of active interphalangeal joint flexion of thumb. He was taken to the operating room. Intraoperatively, the FPL was found to be discontinuous at the level of the radius fracture site. The FPL was repaired by a modified Kessler technique, and the fracture was repaired with a volar plate. Clinicians must be cautious in possibility of tendon injury complicating a closed distal radius fracture and assessing patients with distal radius fracture following closed reduction.

슈퍼이상스테인리스강 용접열영향부의 피로균열전파거동 및 음향방출 특성

도재윤(Jae Yoon Do),김진환(Jin Hwan Kim),안석환(Seok Hwan Ahn),박인덕(In Duck Park),강창용(Chang Yong Kang),남기우(Ki Woo Nam) 대한금속재료학회 ( 구 대한금속학회 ) 2002 대한금속·재료학회지 Vol.40 No.9

Because duplex stainless steel shows the good strength and corrosion resistance properties, the necessity of duplex stainless steel, which has long life in severe environments, has been increased with industrial development. The fatigue crack propagation behavior of heat affected zone(HAZ) has been inrestigated in super duplex stainless steel. The fatigue crack propagation rate of HAZ of super duplex stainless steel was faster than that of base metal of super duplex stainless steel. We also analysed acoustic emission signals during the fatigue test with time-frequency analysis method. According to the results of time-frequency analysis, the frequency ranges of 200-400 kHz were obtained by striation and the frequency range of 500 kHz was obtained due to dimple and separate of inclusion.

속폐쇄근에 발생한 화농성 근염 -증례 보고

김도영 ( Do Young Kim ),박승재 ( Seung Jae Park ),장준동 ( Jun Dong Chang ),남주석 ( Ju Suk Nam ),이상수 ( Sang Soo Lee ) 대한고관절학회 2010 Hip and Pelvis Vol.22 No.4

골격근의 세균 감염으로 인한 화농성 근염은 범세계적으로 증가 추세 이며 특히 소아 및 젊은 성인 층에서 많이 보고되고 있다. 저자들은 29세 남성에게서 발견된 속폐쇄근의 화농성 근염 1예를 보고하고자 한다. 화농성 근염이 주로 하지의 근육에서 발생하기는 하지만 속폐쇄근에 국한되어 발생된 화농성 근염의 경우 진단에 많은 어려움이 있다. 조영 증강 전산화 단층 촬영 검사를 통하여 진단할 수 있었으며 수술적 치료 없이 항생제를 이용하여 치료하였다. 무엇보다도 화농성 고관절염과의 감별진단을 통한 빠른 진단이 중요하며, 화농성 근염의 임상 증상 및 치료를 문헌 고찰과 함께 보고하는 바이다. Pyomyositis is a primary bacterial infection of skeletal muscle and this is on the increase worldwide among children as well as young adults. We report herein on a case of a 29-year-old male with pyomyositis of the obturator internus. The fact that pyomyositis predominantly affects the muscles of the lower limb and it is confined to the obturator internus muscle has been poorly recognized. CT with an enhancement was an accurate imaging modality to image the obturator internus muscle and to ascertain the diagnosis for this case. The patient was managed with antibiotics and surgical intervention was not necessary. Pyomyositis of the obturator internus muscle needs to be differentiated from septic arthritis of the hip. The present study reports the clinical signs and treatments of pyomyostis and we review the relevant literature.