갈륨액체금속 이온원과 인듐액체금속 이온원의 빔 특성에 대한 연구

현정우,임연찬,정강원,정원희,박철우,이종향,강승언 한국공작기계학회 2005 한국공작기계학회 춘계학술대회논문집 Vol.2005 No.-

본 연구에서는 인듐 액체금속이온원을 제작하여 빔 특성에 대해 연구를 하였으며, 기존에 연구를 하였던 갈륨 액체금속이온원의 빔특성과 비교 분석 하였다. 빔특성 분석을 위해 빔 안정도, 전류-전압특성곡선, 에너지 퍼짐을 측정하였다. 액체금속이온원에 사용되는 액체금속 저장소 및 바늘전극(tip)은 500μm의 직경을 갖는 텅스텐을 사용하였으며, 국내에서 제작된 제품을 사용하였다. 액체금속 저장소의 구조는 이전에 구상하여 연구가 이루어진 6개의 pre-etching된 텅스텐와이어(wire)가 묶여진 형태를 사용하였다.

복합섬유 보강 고인성 시멘트 복합체의 특성

윤현도,양일승,한병찬,福山洋,전에스더,문연준 대한건축학회 2004 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.24 No.1(구조계)

In this paper, workability, fiber dispersion. compressive strength and splitting strength of hybrid fiber reinforced cement composites(HFHCC) have been investigated by means of Korean Standard (KS). Two type of HFRCC were constructed using fiber combinations of Polyethylene(PE) and steel fibers. Polyvinyl alcohol(PVA) and steel fibers. Test results showed that the fibers, when used in a hybrid form. could result in superior composite performance compared to their individual fiber reinforced cement Composites. Synthetic micro fibers. such as PE and PVA. are effective at imparting fiber dispersion and ductility to the steel fiber (five twisted steel fiber) reinforced cement Composite.

복합섬유 보강 고인성 시멘트 복합체의 인장거동

윤현도,양일승,한병찬,福山洋,전에스더,문연준 대한건축학회 2004 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.24 No.1(구조계)

An overview of the response highly ductile hybrid fiber reinforced cementitious composites to bending loading, direct tensile loading, and cyclic loading in both tension and compression is presented. Hybrid fiber reinforced cement composites(HFHCC) contains both of specially processed steel fiber( steel cord) and synthetic fiber. such as. Polyethylene(PE) and Polyvinyl alcohol(PVA). As the result of the bending tests. HFHCC specimen shows multiple cracking in the area subjected to the greatest bending tensile stress. Uniaxial tensile test confirms the range of tensile strain capacity from 0.5 to 1.5% when hybrid fiber is used. The cyclic loading test results identified a unique unloading and reloading response for this ductile composite. Cyclic loading in tension appears not to affect the tensile response of the material if the uniaxial compressive strength during loading is not exceeded.

대구지역 가로수잎의 중금속

이찬형,윤현숙,박연준,권종대,노기철,장성환 한국환경과학회 2002 한국환경과학회지 Vol.11 No.12

This study was conducted to determine the contents of heavy metals in leaves of roadside trees according to different growth stages in Daegu city. The orders of heavy metal contents in leaves of roadside tree and soil were Fe〉Mn〉Zn〉Pb〉Cu〉Cr〉Cd and Fe〉Mn〉Zn〉Cu〉Pb〉Cr〉Cd, respectively. The contents of heavy metals in leaves of roadside trees and soil showed an increasing tendency as the levels of traffic volume increased. The contents of heavy metals in leaves on October were higher than those on May.

재생굵은골재를 사용한 콘크리트의 동결융해 특성

성찬용,윤준노,김영익,임상혁,정덕현 충남대학교 농업과학연구소 2003 농업과학연구 Vol.30 No.2

이 연구는 플라이 애시를 결합재 중량의 20%, 재생굵은골재를 천연쇄석굵은 골재의 0%, 25%, 50%, 75%, 100%를 치환하여 압축강도와 동결융해 특성을 구명하였으며, 이 연구를 통해 얻어진 결과를 요약하면 다음과 같다. 1. 재령 28일의 압축강도는 모든 배합비와 W/B 35%에서 400㎏f/㎠이상으로 나타나 고강도콘크리트에 이용될 수 있을 것으로 생각된다. 2. 중량감소율은 동결융해 300사이클에서 1%미만으로 나타났고, 표면박리와 같은 현상은 나타나지 않았으며, 재생골재의 대체율이 증가할수록 감소율은 증가하였다. 3. 초음파진동속도는 동결융해 300사이클에서 19~24%정도의 감소율을 나타내었으며, 재생골재의 대체율이 증가할수록 감소율은 증가하는 경향을 나타내었다. 4. 상대동탄성계슈는 재생골재의 대체율에 따라 60~72%의 범위로 나타내었으며, 재생골재 대체율이 증가할수록 감소하는 경향을 나타내었다. 5. 내구성지수는 모든 배합에서 60이상을 나타내었으나, 재생골재 대체율이 100%일때는 급격히 떨어지는 경향을 나타내었다. 6. 재생굵은골재를 사용한 콘크리트의 압축강도, 중량감소율, 초음파진동속도, 상대동탄성계수, 내구성지수 시험결과를 볼 때, 시험에 사용한 재생굵은 골재는 고강도콘크리트에 사용이 가능할 것으로 판단된다. This study was performed to examine the freezing and thawing properties of the high strength concrete using recycled coarse aggregate. The recycled coarse aggregate was replaced by 0%, 25%, 50%, 75% and 100% of natural crushed aggregate. The compressive strength of the concrete used recycled coarse aggregate was shown in more than 400kgf/㎤ at the curing age 28 days. The weight loss ratio by freezing and thawing was shown in less than 1% at all mix type. The pulse velocity and relative dynamic modulus were decreased with increasing the freezing and thawing cycles. Also, durability factor for the freezing and thawing were decreased with increasing the content of recycled coarse aggregate. But, recycled concrete replaced with recycled coarse aggregate 100% was shown in more than 60 by durability factor in freezing and thawing of 300cycles Accordingly, these recycled coarse aggregate can be used for high strength concrete.

실험적 뇌경색의 형태학적 관찰에서 Neutral Red와 Tetrazolium Salt 교차 염색의 의의

서정호,박윤관,김명현,정용구,정흥섭,서중근,이훈갑,주정화,이기찬 대한신경외과학회 1992 Journal of Korean neurosurgical society Vol.21 No.8

Serial changes in the size of infarcted area induced by MCA occlusion(MCAO) were compared with Neutral Red(NR) and 2,3,5-Triphenyl tetrazolium chloride(TTC) stains. The differences in size of the infarcted area as shown by the 2 stains and its significance were also evaluated. The experimental animals were divided into 7 groups, with each group consisting of rats; these groups were stained at 2,4,6,8,12,24 and 48 hours after MCAO. After MCAO, NR was infused into the femoral vein, after which the brain was removed, the frontal pole of the brain cut into 1.5㎜ sections, and each section photographed. Then, the NR-stained sections were immersed in TTC solution for 45 minutes and photographed. Results showed that the infarcted area progressively increased according to time duration after MCAO(one-way ANOVA, p<0.01). Between 4 and 6 hour groups, the difference of the infarcted area was greater than at any other timed groups, this being statisfically significant(unpaired t-test, p<0.05). After 6 hours, the infarcted area with NR stain became relatively stable. In contrast, however, the infracted area with TTC stain did not stabilize, but continued to increase up to 24 hours. Overall, the infarcted area with NR stain was greater than with TTC stain in all the timed groups(paired t-test, p<0.05). As time progressed, the differences tended to decrease 48 hours post occlusion. In our study, serial changes of the ischemic penumbra area were evaluated by staining the ischemic area simultaneously with Neutral red and TTC stain. The results suggest that the ischemic penumbra area may still persist even after 48 hours post-MCAO.

高靭性 纖維補强 시멘트 複合體를 使用한 耐震要素의 履歷特性

양일승,윤현도,김선우,박완신,한병찬,문연준 대한건축학회 2005 大韓建築學會論文集 : 構造系 Vol.21 No.1

Concrete is one of the principal materials for the structures and It is widely used all over the world While advanced technologies of concrete have been recently focused especially on developing high performance concrete In which possess high compressive strength and durability, such concrete shows extremely brittle failure under shear and tension To Improve such a poor properties, high performance fiber reinforced cement composites(HPFRCC) has been developed For forming multicrack, a large number of fiber and/or the high specific area with thinner fibers are required However, It causes difficulties for the extrusion because of the poor workability So, this theses was suggested adequate mixing method and mix proportion for cach fibers and experimentally observed Structural performance of the seismic devices made by steel bar and HPFRCC These dampers will be applied for reducing damage as weil as seismic response The advantages of the HPFRCC damper is selective structural performance, strength, stiffness, and ductility by changing configuration, bar arrangements and type of materials used The experimental results indicate that elemental ductility is much increased with decreasing damage when the HPFRCC are applied to the damper It means cementitious seismic damper for structure control is available, which has much merit in performance and cost

심장으로 전이된 악성 흑색종의 고식적 절제 1예

이경수,이현희,연태진,남기병,김동운,조명찬 대한순환기학회 2000 Korean Circulation Journal Vol.30 No.9

폐 내 병변으로 인한 소아 급성 호흡부전의 원인 질환과 예후

이혜영,박지숙,최희라,서지현,김점수,임재영,최명범,박찬후,우향옥,윤희상 대한소아과학회 2004 小兒科 Vol.47 No.5

항암화학요법 중 호중구감소증이 발생한 저위험군 발열 환자들을 대상으로 한 경구 항균제 요법의 임상적 유용성 및 안정성에 대한 연구

김연숙,이혁,기현균,김춘관,김신우,김성민,백경란,김원석,윤성수,이홍기,강원기,박찬형,박근칠,송재훈 대한화학요법학회 2000 대한화학요법학회지 Vol.18 No.1

목적 : 항암화학요법 중 호중구감소증을 동반한 발열이 발생하는 암환자들을 치료하기 위한 다양한 항균제와 여러 가지 방법들이 시도되고 있는 가운데, 합병증과 사망률의 발생가능성이 적은 저위험군 환자들을 대상으로 초기 72시간동안 정주 항균제를 투여한 이후 경구 항균제로 전환하는 요법의 유용성과 안정성을 평가해보고자 본 연구를 시행하였다. 방법 : 1998년 2월부터 1999년 9월까지 본원에서 항암화학요법 중 호중구감소증과 발열이 발생한 환자들 가운데 기저 암질환이 고형암이거나 림프종이고, 입원당시 패혈증의 증후가 없으며 입원 72시간이내에 해열되고 백혈구수치가 증가 추세인 환자들을 대상으로 하여 72시간 동안 정주 항균제를 투여한 이후 경우 ciprofloxacin 750㎎을 하루 2회씩 투여하여 총 4일간 투여하였다. 모든 환자들은 열이 떨어지고 호중구감소증이 회복될 때까지 입원하도록 하였다. 결과 : 총 38명 환자의 40예가 등록이 되었고, 환자들의 기저암 질환은 고형함이 72.5%, 림프종이 27.5%였다. 입원당시 평균 호중구치수는 156/㎕였고, 호중구수치가 100/㎕미만인 경우는 65%였으며, 호중구감소증이 지속된 기간의 평균은 2.4일이었다. 40예 중 39예가 항균제의 변형이나 추가 없이 호중구감소증과 발열로부터 회복이 되어 97.5%의 성공율(95% 신뢰구간: 86.8-99.9%)을 보였다. 부작용으로 피부발진이 있었던 경우가 한 예 있었는데, 증상이 경하여 경구 항균제를 지속할 수 있었다. 심와부의 동통으로 복용을 지속할 수 없어서 대상에서 제외된 예가 또 한 예 있었다. 결론 : 항암요법 중 호중구감소증과 발열을 동반한 환자들 가운데 저위험군 환자들에서 항균제 72시간정주 이후 경구 항균제로의 전환요법은 효과적이고도 안전한 치료방법이라고 할 수 있다. Background : Oral antibiotic therapy following empirical intravenous antibiotics may be effective and safe for febrile neutropenic patients with lowrisk for complications. Methods : We conducted a prospective clinical trial of oral antibiotic therapy in the patients with neutropenia and fever during chemotherapy for cancer. Underlying malignancies were solid tumor or lymphoma with short duration of neurtropenia and the patients had no evidence of clinically or microbiologically documented infections. Oral ciprofloxacin was given to the patients who lacked signs of sepsis on admission, had a rising tendency of neutrophil count (ANC >100 /㎕ ) at 72 hours, and were afebrile at 72 hours. All patients were hospitalized until neutropenia and fever resolved. Results : A total of 40 episodes of 38 patients were enrolled from February 1998 to September 1999. The mean neutrophil counts on admission were 156/㎕ and the mean duration of neutropenia was 2.4 days. The episodes which had neutrophil count below 100 /㎕ were 26 (65%). Treatment was successful in 39 of 40 episodes (97.5% : 95 % confidence interval, 86.8% to 99.9%). Adverse reactions of oral ciprofloxacin were skin rash and epigastric soreness in two cases, respectively. There were no deaths during the study. Conclusions : For low-risk febrile patients with neutropenia during cancer chemotherapy, switch therapy to oral ciprofloxacin at 72 hours following intravenous broad-spectrum antibiotics is effective and safe,