소화성궤양 환자에 대한 Omeprazole(Losec^(�))의 임상 효과

이종선,이기천,허승식,안정기,윤세진,정현용,이헌영,김영건 최신의학사 1990 最新醫學 Vol.33 No.9

Characterization and Property Evaluation of Ti‑Based Target Materials and Their Nitride Nano‑composites Coating Layers

Jeong‑Han Lee,Hyun‑Kuk Park,장준호,Ik‑Hyun Oh 대한금속·재료학회 2019 METALS AND MATERIALS International Vol.25 No.1

This study formed a hard TiAlSiWN coating layer using Ti, Al, Si and W raw powders that were mechanically alloyed andrefined. The TiAlSi and TiAlSiW coating targets were fabricated using a pulse current activated sintering process in a shorttime with the optimal sintering conditions. The optimized sintering condition was obtained by controlling process parameterssuch as temperature, pressure, heating rate and pulse ratio (on/off). The coating targets were successfully deposited onthe WC substrate to form the TiAlSiN and TiAlSiWN nitride nano-composite structures by an arc ion plating process andalso, their coating layers were compared according to the addition of W element. The microstructures of the nitride nanocompositecoating layer were analyzed, focusing on the distribution of the crystalline phases, amorphous phases (Si3N4),and growth orientation of the columnar crystal depending on the addition of W element. The mechanical properties of thecoating layers were exhibited a hardness of approximately 3000 kg/mm2 and adhesion of about 117.77 N in the TiAlSiN. Inparticular, the TiAlSiWN showed excellent properties with a hardness of more than 4300 kg/mm2 and an adhesion of about181.47 N, respectively.

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.

KAERI 부지 주변의 환경선량 측정을 위한 온라인 감마선량 감시시스템

이정호,박두원,이원윤,이현덕,최용호,김삼랑,홍광희,이창우 대한방사선 방어학회 1994 방사선방어학회지 Vol.19 No.2

환경감마선량 변동을 감시하기 위해 한국원자력연구소 부지 주변에 온라인 감마선량 감시망을 구성하였다. 모니터링 포스트에 설치된 전리함 검출기에 의해 측정된 자료는 무선전송방식으로 중앙통제소에 전송되어 실시간으로 감시된다. 무선전송 방식은 자료의 전송, 처리 및 자자에 신뢰도가 높고 경제적이었다. 감시시스템은 급격한 선량증가시 조기경보체제와 연결할 수 있게 하였다. On-line gamma monitoring system around KSERI-site was set up to monitor the radiation fluctuations in environment. Data on gamma exposure rates measured by the ionication chamber in the monitoring posts are transmitted to a computer of central control station with radio telemetry transmission and reliable on handing and storing of data. This monitroing system can triger an early warning system in the event of abnormal radiation levels.

이행성 협심증 환자에서 운동부하 심전도 검사

이정우,박형서,박용규,노상필,이유선,정승현,김보영,이재환,최시완,정진옥,성인환 충남대학교 의과대학 의학연구소 2003 충남의대잡지 Vol.30 No.1

목적 : 관상동맥의 경련에 의한 이형성 협심증환자에 있어서 운동부하 심전도 검사의 결과는 매우 다양하다. 이에 저자들은 충남대학교병원 순환기내과에서 관상동맥조영술상 이형성 협심증으로 확진된 환자를 대상으로 운동부하 심전도 검사를 시행하여 이에 대한 결과를 연구하였다. 방법 : 1995년 1월부터 2002년 3월까지 흉통을 주소로 충남대학교병원 순환기 내과에 입원하여 관상동맥조영술을 시행하여 관상동맥의 내경이 50% 미만의 협착이 있고, 에르고노빈(ergonovine) 유발검사도 이형성 협심증으로 진단을 받은 233명중 운동부하 심전도 검사를 시행 받은 183명의 환자를 연구 대상으로 하였다. 운동부하 심전도 검사 결과의 판독시 발생할 수 있는 오류를 줄이기 위해서 운동부하 심전도 검사를 시행하기전 심전도상 ST분절의 상승(5예)이나 하강(8예)이 있는 경우 EH한 T파의 역위(19예)가 있는 32명의 환자를 제외한 총 151명의 환자를 대상으로 하였다. 운동부하는 Marquette사의 case 15 답차를 이용하였고, Bruce protocol에 따라 증상이 나타날 때까지 최대로 실시하였으며 각 stage 및 운동후의 혈압을 측정하고 12 유도 심전도를 기록하였다. 결과 : 1) 임상적 특성 - 내원시 임상 상은 안정형 협심증이 39예(25.8%), 불안정형 협심증이 103예(68.2%), 심근경색증이 9예(6.0%)이었다. 운동부하 심전도 검사 결과 양성 군과 음성군간에 있어서 당뇨병, 고혈압, 비만도, 총 혈청콜레스테롤치, 현재의 흡연 여부, 병력상 운동시 흉통의 유무, 내원시 임상적 진단, 협착의 정도, 연축의 수 등을 조사하였는 바 어떠한 인자들도 유의한 차이를 발견할 수 없었다. 2) 운동부하 심전도 검사 - 운동부하 심전도 검사를 시행 받은 151명의 환자중 음성인 경우는 134예(88.8%)이었고, 양성인 경우는 17예(11.2%)이었다. 양성 소견을 보인 환자들중 ST 분절의 상승이 4예(2.6%), ST 분절의 하강이 13예(8.6%)이었다. 3) 관상동맥조영술 - 관상동맥조영술상에서 혈관 경력 위치는 우관상동맥이 70예(46.1%), 좌전하동맥이 44예(28.9%), 좌회선동맥이 17예(11.2%)의 순으로 나타났다. 운동부하 심전도 검사상 ST 분절의 상승이 있었던 예중 Ⅱ, Ⅲ, aVF에서 ST 분절의 상승이 있었던 1예는 관상 동맥조영술상 우관상동맥에서 경련이 발생하였고, V2-V4에서 ST 분절의 상승이 있었던 2예중 관상동맥조영술상에도 좌전하행동맥에서 경련이 나타난 예는 1예이었으며 다른 1예는 좌회선동맥에서 경련이 나타났고, V5-V6에서 ST 분절의 상승이 있었던 1예는 관상동맥조영술상에도 좌회선동맥에서 경련이 나타났다. 운동부하 심전도 검사상 V5 또는 V6에서 ST 분절의 하강이 있엇던 13예중 6예(46.1%)는 관상동맥조영술상 우관상동맥에서 경련이 발생하였고, 3예(23.1%)는 좌전하행동맥에서, 1예(7.7%)는 좌회선동맥에서, 나머지 3예(23.1%)는 2개의 혈관이나 기타 분지에서 경련이 발생하였다. 결론 : 1) 이형성 협심증 환자는 운동부하 심전도 검사에서 11.2%의 양성소견을 보였다. 이중 ST 분절의 상승은 2.6%이었고, ST 분절의 하강은 8.6%이었다. 2) 이형성 환자중 운동부하 심전도 검사를 실시하여 음성을 보이는 경우 다혈관 관상동맥질환이기 보다는 이형성 협심증일 가능성이 더 높다고 예측할 수 있을 것으로 생각된다. 3) 이형성 협심증 환자중 운동부하 심전도 검사를 실시하여 ST 분절의 상승을 보이는 경우 다혈관 관상동맥질환이기 보다는 이형성 협심증일 가능성이 더 높다고 예측할 수 있을 것으로 생각된다. 4) 운동부하 심전도 검사 결과에 대한 당뇨병, 고혈압, 비만도, 총 혈청콜레스테롤치, 현재의 흡연여부, 병력상 운동시 흉통의 유무, 내원시 임상적 진단, 협착의 정도 등 어떠한 인자들도 3그룹(ST 분절의 상승, ST 분절의 하강, 음성)간에 유의한 차이를 발견할 수 없었다. 5) ST 분절의 상승 부위와 관상동맥조영술상 관상동맥의 연축이 일어나는 혈관과의 상관관계는 매우 높았다. No reports in the literature describe the results of exercise testings in a large number of patients with pure variant angina(coronary stenosis <50%) in Korea. In this report, We present the results of treadmil exercise testing in 151 patients with variant angina. 151 patients with angiographically proven coronary artery spasm underwent a treadmil exercise test. The clinical characteristics of variant angina patients classified according to ST-segment response to exercise were analyzed. Of 151 patients underwent a treadmil exercise test, negative result was seen in 134 patients(88.8%) and positive result was in 17 patients(11.2%). Of 17 patients saw positive result, exercise-induced ST segment elevation was present in 4 patients(2.6%) and ST segment depression was seen in 13 patients(8.6%). There was not a significant relationship between the ST segment response to exercise and the clinical variables(diabetes, hypertension, obesity, total cholesterol, current smoking, effort angina, clinical diagnosis, and degree of stenosis) assessed. Of 4 patients with ST segment elevation in treadmil exercise test, 1 patient with ST segment elevation in Ⅰ,Ⅲ,aVF had spasm in right coronary artery(100%) on coronary angiography, of 2 patients in V2-V4 had spasm in left anterior descending coronary artery in 1 patient(50%) and 1 patient in V5-V6 had spasm in left circumflex artery(100%). Positive treadmil exercise test was present in 11.2% of variant angina patient. If we have negative treadmil exercise result in patients with clinical manifestation of unstable angina at admission, we may have a suspicion of variant angina rather than multi-vessel disease. If we have exercise-induced ST segment elevation in patients with clinical manifestation of unstable angina at admission, we have a suspicion of variant angina rather than multi-vessel disease. Our result suggests that the correlation between the site of the ST segment elevation and the artery involved is quite good.

에어컨 냉각 팬용 브러쉬레스 DC 전동기의 역기전력 분석에 대한 연구

조정현,김지현,정정원,황흥식,이치우 경성대학교 공학기술연구소 2012 공학기술연구지 Vol.18 No.-

Compared to conventional dc motors having the combination of commutators and brushes, a brushless DC (BLDC) motor is one of the highly efficient motors due to its electrical commutation without a brush, and this feature allows the BLDC otor to be more suitable for an application requiring no maintenance due to mechanical wear between a commutator and a brush. Also, the BLDC motor has a few benefits over both a dc motor and an induction motor such as high dynamic response, high efficiency, logn life span, and low noise in wide speed-torque region. This paper investigates the variation of voltage induced in phase windings in a BLDC motor in several cases with respect to stack length, steel grade, and coil material. This study is numerically conducted and it is verified from the theoritical point of view by comparing the result of simulation with that of experimental measurement.

심인성 어지럼증 환자의 정신과적 증상에 관한 연구

이경규,이지영,김현우,이정엽,백기청,김재일,이근호 大韓神經精神醫學會 1999 신경정신의학 Vol.38 No.5

연구목적 : 어지럼증을 호소하는 환자들 중에 심인성 어지럼증 환자가 상당수 있다는 것은 알려져 있고, 이러한 심인성 어지럼증과 동반되는 정신질환으로는 불안장애, 우울장애, 인격장애 등이 있다. 이에 본 연구에서는 심인성 어지럼증 환자들의 빈도와 정신과적 증상을 알아보고자 하였다. 방 법 : 어지럼증 환자들에게 평형검사, 자세운동측정검사, 자세변화검사, caloric testing을 시행하여 심인성, 말초성 및 중추성의 3군으로 분류한 후 각각 14명, 16명, 32명을 대상으로 하였다. 대상환자들에게 한국판 Beck 우울척도검사(K-BDI), Spielberg의 상태-특성 불안검사(STAI). 간이정신진단검사(SCL-90-R)를 이용하여 정신과적 증상을 측정하여 이들 세 군을 비교분석하였다. 결 과 : 1) 심인성 어지럼증을 가진 환자는 어지럼증을 나타내는 환자 총 62명중에서 14명으로 22.6%를 차지하였다. 2) K-BDI에 따른 세 군간의 비교에서는 세 군간에 유의한 차이를 보이지 않았다. 3) STAI에 따른 세 군간의 비교에서 상태불안(STAI-S) 및 특성불안(STAI-T) 모두에서 세 군간에 유의한 차이를 보이지 않았다. 4) SCL-90-R에 따른 세 군간의 비교에서는 9개의 척도 중에서 공포불안척도에서만 중추성 어지럼증군이 47.56±6.90, 말초성 어지럼증 군이 53.50±13.74, 심인성 어지럼증 군이 58.50±16.05로 심인성 어지럼증 환자군이 중추성 어지럼증 환자군에 비하여 유의하게 높은 것으로 나타났다(p<0.01). 5) 통증 증상에 있어서는 세 군간에 유의한 차이를 보이지 않았고, 위장관 증상과 성기능 장애 증상은 중추성과 말초성 어지럼증 군이 심인성 어지럼증 군에 비하여 유의하게 높은 것으로 나타났다(p<0.01). 결 론 : 상기 결과를 토대로 했을 때 어지럼증 환자들에 대한 정신과적 접근을 위하여 각 군을 나누는 것은 별 의미가 없으며 어지럼증 환자들의 어지럼증 자체에 대한 직접적이고 집중적인 치료가 더욱 필요할 것으로 생각된다. Objectives : This study was aimed to investigate psychiatric symptoms in patients with psychogenic dizziness and compare these findings with those of patients with central and peripheral dizziness. Methods : A total of 62 patients with dizziness was the subject of investigation, and patients were classified into 32 with central type, 16 with peripheral type, and 14 with psychogenic type. Korean standardized Beck Depression Inventory(K-BDI), State and Trait Anxiety Inventory(STAI), and Korean standardized edition of Symptom Checklist 90 Revised(SCL-90-R) were used for the assessment. Statistically, Pearson's chi-square test and one-way ANOVA with Scheffe's test were used with SPSS/PC for windows 6.0. Results : The results were as follows : 1) The proportion of psychogenic dizziness was 22.6% of the total subjects. 2) Total scores of K-BDI were not significantly different among the 3 groups. 3) Total scores of state anxiety and trait anxiety were not significantly different among the 3 groups. 4) In SCL-90-R, psychogenic dizziness group showed significantly higher score of phobic anxiety only(p<0.01) than central dizziness group. And others were not significantly different among the 3 groups. 5) In additional somatic symptoms, pain score was not different among the 3 groups, but gastrointestinal and sexual symptoms scores of central and peripheral dizziness group were significantly higher than those of psychogenic dizziness group(p<0.01). Conclusion : These results suggest that psychiatric symptoms in patients with psychogenic dizziness are not different from those of patients with central or peripheral dizziness. Therefore, the more direct and intensive treatment may be necessary regardless of the type of dizziness.

Rapid Consolidation of WC‑ZrSiO4 Hard Materials by Spark Plasma Sintering: Microstructure, Densification, and Mechanical Properties

Jeong‑Han Lee,Ik‑Hyun Oh,Ju‑Hun Kim,Sung‑Kil Hong,Hyun‑Kuk Park 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.9

Densely consolidated WC-based hard materials with 5–20 vol% ZrSiO4was fabricated by spark plasma sintering at 1400 ℃ ata constant heating rate of 70 ℃/min−1. To achieve mechanical alloying of WC-ZrSiO4, planetary ball milling was carried outfor 12 h, during which the brittle-brittle components (WC-ZrSiO4) became fragmented and their particles became refined. Itwas observed that certain, specific, non-isothermal sintering kinetics, such as apparent activation energy, sintering exponents,and densification strain, affected the densification behavior. The evolution of phase structure from powder to compact wasfound to be related the lattice distortion and micro-strain in the basal planes of WC. By examining the mechanical propertiesof the samples, it was that the added zircon content leads to enhanced fracture toughness (12.9 MPa m1/2) owing to thepresence of WC-ZrSiO4 in the cemented carbide. In fact, the microcrack propagation of the fracture passed through zirconfrom a transgranular to a ductile component (fcc) where the crack tips could be absorbed.

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.

완전 방실차단을 동반한 급성 심근염

이유선,정진옥,박용규,박형서,노상필,정승현,김정희,이재환,최시완,성인환 충남대학교 의학연구소 2003 충남의대잡지 Vol.30 No.2

급성 심근염환자에서 발행한 완전 방실차단을 영구 심장박동 조율기로 치료한 1예를 경험하였기에 문헌고찰과 함께 보고하는 바이다. Myocarditis, an inflammatory process involving the myocardal wall, may be caused by most infectious agents. Irrespective of its etiology, it presents commonly with evidence of heart failure, hypotension, and various electrocardiographic abnormalities. Patient with myocarditis may be asymptomatic or may have a rapidly progressive fatal disease. Medical management of patients with myocarditis includes specific therapy for underlying infection and control of the complication of myocarditis such as congestive heart failure and arrhythmia. Recently we had experienced myocarditis with complete atrioventricular block in 37-year-old man. Although he had shown complete recovery of heart failure, he had shown complete atrioventricular block, so we inserted permanent pacemaker. We report it with review of the literature.