Effect of Mechanical Alloying on the Microstructural Evolution of Al60Cr30Si10 Alloys Processed by Spark Plasma Sintering

Jeong‑Han Lee,Ik‑Hyun Oh,Jun‑Ho Jang,Ju‑Hun Kim,Sung‑Kil Hong,Hyun‑Kuk Park 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.5

In this study, Al, Cr and Si fine powders were alloyed by planetary ball milling to investigate their microstructural evolution,following their mechanical alloying behavior. The formation of Al(Cr) supersaturated solid solution by the Cr grainsembedded in Al-matrix, which contributed substitutional structure is discussed in relation to their structural evolution inaccordance with the distortion of a crystal lattice. The compacts of Al–Cr–Si alloys were prepared by rapid sintering withina short time by dense consolidation above the density of 99.9% as the formation of intermetallics, except in the case of thedistribution of single-phases induced by the Al-melting. The formation behavior of intermetallics was dominated by dependenceon the structures of the milled-powder and subsequent sintering temperature. To estimate the consolidated behaviorsof compacts, various approaches derived from TEM and XRD analysis were taken to obtain microstructural evidences ofthe inter-diffusion, following the presence of thermally stable intermetallics.

반도체 산업에서의 Enterprise Document Management Architecture 구현에 관한 연구

장현성,이영중,송하석,한영준,안정삼 한국경영과학회 2001 한국경영과학회 학술대회논문집 Vol.- No.2

A systematic construction and re-use of technology related to the product development and production has been the most important for the semiconductor industry dependent on process and equipment Therefore, numerous outputs in the form of paper has been produced in the process of information management ranging from the creation to recycling and disposal of technologies. In this research, the technology and documents necessary for the business management in the field of semiconductor manufacturing were classified in an effort to solve problems while the modeling of document management architecture at the enterprise level was performed by properly setting up the security system to prevent the unauthorized disclosure of the product development technology to the third parties. Especially, the product and process specification are designed in such a way as to ensure a real-time response in interface with the production system in order to shorten the development lead-time and improve the productivity. This paper is to discuss the modeling approach, the strategy to construct the system and its results.

Influence of Phase Composition in TiAlSiN Hard Coatings on the Evolution of Structure and Mechanical Properties

Jeong‑Han Lee,Ik‑Hyun Oh,Jun‑Ho Jang,Ju‑Hun Kim,Sung‑Kil Hong,Hyun‑Kuk Park 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.3

The aim of this study is to investigate the structural evolution and mechanical properties of TiAlSiN coatings when processedby the arc ion plating method. To form a hard coating, Ti, Al, and Si powders were mechanically alloyed by planetary ballmilling; the powders were then densely compacted during a rapid sintering process into a ternary system coating, i.e. TiAlSi. The evolution of the structural phase from a powder to a compact material is dominated considerably by phase states suchas a supersaturated solid solution or intermetallic compounds. In the case of coating layers, the factors that determine thestructural evolution are associated with the phase stability of the nano-crystalline structure that in turn is associated withthe Ti/Al composition ratio. Motivated by this, we performed experiments to investigate the distribution of microstructures;the material’s binding energy, quantitative properties, transformation of crystal structure, and distribution of amorphous/crystalline were all recorded. In particular, the relationship between the physical and chemical properties during the coatingprocess is considered to be the dominant factor controlling the orientation and morphology of that zone (1, T, and 2). TheTiAlSiN coating layer was found to have hardness above 45 GPa and an adhesion above 100 N. In other words, understandingthe evolution and structure of TiAlSin helped us to produce a material with excellent properties that can be used as a hardcoating. Specifically, these properties were induced by a grain refinement of the nano-crystalline structure that correspondsto an increase in the silicon nitride contents.

응급실에서 소아환자의 진정제로서 케타민(Ketamine)의 사용

서정필,박준석,황태식,장석준,김승호 대한응급의학회 2000 대한응급의학회지 Vol.11 No.3

Background: Ketamine use in emergency room has been increased. It has rapid onset of action and appropriate duration of action. It does not need endotracheal intubation and produces potent analgesia, sedation, and amnesia. The object of this study is to determine the safety and the degree of physician's satisfaction in relation to ketamine use. Materials and Methods: This is a prospective study using protocol. Pediatric trauma patients who need sedation were given IM ketamine(4 ㎎/㎏) and atropine(0.01 ㎎/㎏) in a same syringe. Monitoring of patients was done by EM residents and complications of ketamine use were recorded. Physician's satisfaction was also recorded after the procedure. Results: Intramuscular ketamine was administered 54 times, mainly for laceration repair. Physicians completed protocol for 51 of treated children. The median time for onset of sedation was 6.5±2.4 min, and duration of action was 32.4±10.8 min. Hypersalivation occurred in 9.8%(n=5); random movement 3.9%(n=2), emesis during procedure(n=1), emesis at home(n=1), and transient oxygen desaturation(n=1). All were quickly identified and treated without specific airway management and sequelae. Of 84% of physicians was satisfied with ketamine use for pediatric sedation. Conclusion: Intramuscular ketamine can be administered safely and satisfactorily in emergency room to facilitate pediatric procedures in conjunction with a defined protocol and appropriate monitoring.

분만 후 심한 저혈당이 동반된 림프구성 뇌하수체염 1예의 경과 관찰

손장명,고승현,안유배,주강,이정록,양성은,송기호,손호영,전정수 대한내분비학회 2003 Endocrinology and metabolism Vol.18 No.3

저자들은 출산 후 발생한 심한 저혈당을 주소로 내원한 31세 여자 환자에서 뇌 자기공명영상검사에서 뇌하수체종괴가 관찰되고 복합 뇌하수체 기능검사 결과전반적인 뇌하수체 기능저하증의 소견을 보여 림프구성 뇌하수체염을 진단하고, 호르몬 보충요법만으로 경과를 관찰하여 호전된 예를 경험하였기에 문헌 고찰과 함께 보고하는 바이다. Lymphocytic hypophysitis, an inflammatory disease of the pituitary gland that is often associated with pregnancy, is caused by autoimmune destruction of the pituitary gland evidenced by diffuse inflammatory cell infiltration of the pituitary gland and some kinds of detectable autoantibodies. We report a case of lymphocytic hypophysitis in a 31-year-old woman presenting with severe hypoglycemia and hyponatremia after delivery. Hormonal study revealed panhypopituitarism and magnetic resonance imaging with enhancement showed the bulging contour of the right side pituitary gland with an ill-defined mass-like lesion and nodular thickening of the stalk The patient's symptoms and biochemical data improved greatly with replacement of L-thyroxine and glucocorticoid. Partial recovery of panhypopituitarism was also seen. The follow-up tests revealed dramatic resolution of the pituitary lesion (J Kor SOC Endocrinol 1 8 : 3 25 -33 1, 2003).

개에서 이중 결찰법을 통한 동맥관 개존증의 완치 예

윤헌영,정순욱,박희명,박철,정만복,김준영,한현정,황민,노병국,박상혁,장하영,박정윤 한국임상수의학회 2004 한국임상수의학회지 Vol.21 No.1

A ten months old, female Yorkshire terrier weighing 2.88 kg referred to veterinary teaching hospital of college of veterinary medicine, Konkuk University because of syncope, cough and dyspnea. First hematological and serum chemical test revealed thrombocytopenia, mild anemia, and increase of concentration of ALP (195 U/L). On 57 days later, second hematological and serum chemical test revealed polycythemia, increase of concentration of ALP (211 U/L), and Tchol (387 mg/dl). Right atrium enlargement, main pulmonary artery bulge and cardiomegaly (VHS = 11.5) were observed in radiographic findings. Ultrasonographic images showed both right and left ventricular dilation and turbulent flow between the descending aorta and the main pulmonary artery in color Doppler imaging. ECG showed left ventricular enlargement, SA block, and electrical alternant. Thoracotomy was performed through left fourth intercostal incision under isoflurane anesthesia. Patent ductus arteriosus was double ligated with 1-0 silk. Cough and dyspnea disappeared on 5 days after operation. Turbulent flow was not found in color doppler imaging of ultrasonography on 10 days after operation. Ten months later after the operation, syncope could not exist any more.

직경 1˝ 자성관에서의 원격장와전류 탐상 실험 빛 결함신호 특성

신영길,이창준,이정호,이윤태,장권규,송성철,송성진,정태언 국립7개대학공동논문집간행위원회 2002 공업기술연구 Vol.2 No.-

In this study, a remote field eddy current testing system is built to inspect 1˝ diameter ferromagnetic tubes and resulting experimental signals are investigated. To decide the operating frequency, the emf of sensor coil is monitored while the sensor coil is moved away from the exciter. At proper frequency, sudden change would occur in the signal pattern. This also indicates the location of remote field region, so that the distance between coils can be decided. The defect signal contains two defect indications, each appears as the sensor and exciter coil passes a defect. Experimental results show that defect depth can be estimated by comparing the two indications. Also, linear relationship between defect depth and phase signal strength is observed.

원형 파일의 파압분포특성에 관한 실험적 연구

함계운,박준일,장대정 경상대학교 생산기술연구소 2003 工學硏究院論文集 Vol.19 No.-

The computation of the water wave forces on offshore structures is one of the primary tasks in the design of the structures. It is also one of the most difficult tasks since it involves the complexity of the interaction of waves with the structures. The Morison equation assumes the wave force to be composed of inertia and drag forces linearly added together. The purpose of this paper is to investigate the wave forces acting on the cylinderical piles. Author set up a cylinderical piles model into 2 dimensional regular wave tank with vaned wave height, water depth, and wave period, and observed wave forced. In practice the wave forces depending on wave height, water depth, and wave period were predicted through the experimental model test. It is presented a good tool to predict qualitatively the wave forces acting on the cyinderical piles.

Risperidone 조기 중단군 및 장기 유지군의 임상적 특성 비교

김광수,박원명,전태연,배치운,김대진,백인호,이철,김정수,한상익,최보문,장계호,고효진 大韓神經精神醫學會 2001 신경정신의학 Vol.40 No.3

연구목적 : Risperidone 투여후 조기 중단한 환자들과 장기적으로 계속 risperidone을 복용하고 있는 환자의 임상적 특성을 평가하고 나아가 risperidone장기 유지와 조기 중단의 요인을 분석하고 정신병리가 약물 투여에 미치는 영향을 조사하고자 하였다. 방 법 : 연구 대상자는 1996년 1월부터 1996년 12월까지 가톨릭대학교 의과대학 부속 8개 병원 정신과에서 risperidone을 투여 시작한 환자 580명중 DSM-IV기준에 의해 정신분열병으로 진단받고 투여 기간이 6개월 미만(조기 중단군)이거나 2년 이상(장기 유지군)을 경과하였으며 의무기록의 누락이 없는 210명을 선정하였다. 두 군간 임상적 특성을 조사하기 위하여 인구학적 변인, 정신병리학적 변인, 약물 투여기록 및 부작용 등을 과거 의무기록을 근거로 평가하였다. 결 과 : 대상환자 210명 중 조기 중단군이 67명(31.9%)이었고 장기 유지군은 143명(68.1%)이었으며 두 군간 인구학적 변인과 정신병리학적 변인에 따른 특징에는 두 군간 차이가 없었다. 두 군간 risperidone의 시작 용량과 변인과 정신병리학적 변인에 따른 특징에는 두 군간 차이가 없었다. 두 군간 risperidone의 시작 용량과 최대 용량은 유의한 차이가 없었으나 유지용량은 조기 중단군에서 4.49(±1.44)mg,장기 유지군에서 3.67(±1.50)mg으로 유의한 차이가 있었다(t=3.698, p<0.05). 또한, 이전 항정신병약물의 사용 기왕력 변인에서 조기 중단군은 기왕력이 없는 환자가 39명(58.2%), 고역가 항정신병약물을 사용한 기왕력이 있는 환자는 27명(40.3%), 저역가 항정신병약물을 사용한 기왕력이 있는 환자는 1명(1.5%)이었고, 장기 유지군은 기왕력이 없는 환자가 58명(40.6%), 고역가 항정신병약물을 사용한 기왕력이 있는 환자는 77명(53.8%), 저역가 항정신병약물을 사용한 기왕력이 있는 환자는 8명(5.6%)으로 유의한 차이가 있었다.(x²=6.559, df-=2, p<0.05). 결 론 : 본 연구결과에 의하면 가급적 환자 상태에 따라 낮은 최적 치료 용량을 투여하는 것이 장기잔의 투여를 바람직한 것으로 생각된다. 본 연구와 같은 대규모의 후향적 자연적 연구는 일반 실제 진료에서 risperidone의 효과 및 기타 다른 측면에서의 유용한 정보를 얻을 것으로 기대된다. Objective : This retrospective naturalistic study was designed to compare the clinical characteristics including psychopathology of two groups of patients, long-term maintenance group and short-term drop-out group, who were taking risperidone. Method : Datas were collected for 210 schizophrenic patients with complete medical records among 580 patients who were enrolled with risperidone administration from January 1996 to December 1996 in 8 affiliated hospital of the Catholic University. The short-term drop-out patients group were assigned to whom treatment period was less than 6 month, and the long-term maintained patients group, treatment period was more than 2 years. We assessed demographics, psychopathology, and other variables related with medication based on past medical records. Results : Among subjects of 210, short-term drop-out patients group were 67(31.9%) and long-term maintained patients group were 143(68.1%). Demographics and psychopathology were not significantly different between two groups. The stating and maximal dosage of risperidone was not significantly different between two groups but the maintenance dosage of risperidone was lower in long-term medicated patients group than short-term drop-out patients group(t=3.698, p<0.05). Additionally, the result of this study showed differences in experiences of past antipsychotic use as following. The number of no previous use of antipsychotic was 39(58.2%), the number of high potency amtipsychotic use was 27(40.3%), and the number of no previous use of antipsychotic was 58(40.6%), the number of high potency ntipsychotic use was 77(53.8%), the number of low potency antipsychotic use was8(5.6%) in long-term maintained group.(x²=6.559, df-=2, p<0.05). Conclusions : According to these results, administration of low therapeutic dosage should be recommended for long-term maintenance as if possible. Multi-center based retrospective naturalistic study like this would be useful for getting informations about efficacy and some other aspects of antipsychotic administration in practial field.

한국어 판 구조화 임상면담도구 개발 : 신뢰도 연구

한오수,안준호,송선희,조맹제,김장규,배재남,조성진,정범수,서동우,함봉진,이동우,박종익,홍진표 대한신경정신의학회 2000 신경정신의학 Vol.39 No.2

연구목적: 정신장애의 정확한 진단과 평가는 임상에서뿐만 아니라 신뢰성 있는 연구를 위해서도 매우 중요하다. Structured Clinical Interview for DSM-IV(SCID)는 임상전문가들이 사용하는 진단도구로서, 비교적 짧은 시간에 정확한 진단을 내릴 수 있다. 본 연구는 한국어판SCID를 개발하고 그 신뢰도를 평가하기 위해 수행되었다. 방법: 국문학자가 포함된 번역위원회를 통하여 연구용판 SCID를 번역한 후, 정신과 의사 2인과 임상심리학자 1인에게 한국어판SCID 실시방법을 교육시킨 뒤 한국어판SCID를 이용한 면담의 평가자간 신뢰도 (interrater reliability)를 검증하였다. 면담 대상은 1999년 2월에서 3월까지 2개 병원 정신과에 치료중인 환자 90명(남:41명, 여:29명)이었다. 결과: 현재 장애(current disorder) 평가에서 주요 우울장애, 기분부전장애, 정신분열병, 알코올 남용 및 의존, 기타 물질 남용 또는 의존, 여러 불안장애들 및 섭식장애 등과 같은 대부분 장애의 kappa값은 .70이상으로 매우 높았다. 그 이외의 양극성 장애, 망상장애, 광장공포증, 감별 불능 신체화 장애 및 건강염려증의 kappa값도 .69에서 .40사이로 수용할 수 있는 정도였다. 평생 장애(lifetime disorder)에서는 양극성 장애(k=.69)와 감별 불능 신체화장애(k=.59)를 제외한 다른 모든 장애의 kappa값이 .70이상이었다. K-SCID 면담시 Ⅰ축 질환에 대하여 흔하게 다중 진단이 내려졌으며, 평균 진단 수는 1.5∼1.7개로 나타났다. 결론: 한국어판 SCID는 신뢰도가 높은 진단도구로 생각되며, 향후 정신질환의 정확한 진단과 임상연구에 유용하게 사용될 수 있다. Objectives: Accurate diagnosis and assessment for psychiatric disorders is crucial for research, as well as for clinical practice. Structured Clinical Interview for DSM-Ⅳ(SCID-RV) is a less time-consumimg and more accurate structured diagnostic interview form. It can be used by clinical professions and is known for a reliable diagnostic tool. Present study was conducted to develop Korean version of SCID-RV and to test the inter-rater reliability. Methods: The authors have translated original SCID-RV into Korean, and revised in parallel with sociocultural background of Korea. Ninety patients from two psychiatric hospitals, both outpatient and inpatient, were interviewed and rated independently by three raters. Results: The kappa coefficients for most of illnesses, such as major depressive disorder, dysthymia, schizophrenia, alcohol abuse and dependency, anxiety disorder and eating disorder were excellent(>0.70) in the evaluation of current disorders. And the kappa coefficients for bipolar disorder, delusional disorder, agoraphobia, undifferentiated somatoform disorder, and hypochondriasis were acceptable(>0.40) in the evaluation of current disorders. In the evalua-tion of lifetime disorders, the concordant rates of all the diagnoses except bipolar disorder and undifferentiated somatoform disorder were excellent. Lack of hierarchy in DSM-Ⅳ allows for multiple Axis I diagnoses. Mean numbers of Axis I diagnoses per subject assigned by the three raters were 1.5-1.7. Conclusions: Our findings confirm that SCID-RV yields highly reliable diagnoses. SCID-RV is recommended for accurate diagnosis in clinical practice and research on psychiatric disorders.