攪伴機에 依한 土狀黑鉛의 球狀凝集

金燦國,姜大雨,金裕鎭 동아대학교 공과대학 부설 한국자원개발연구소 1984 硏究報告 Vol.8 No.2

This study has been carried out to determine the effects of bridging liquid concentrations, agitation time, agitation speed, pulp density, and viscosities of the bridging liquid on growth of the agglomerates by agitating the suspension with bridging liquid which preferentially wets the carbon particles. The results of this experiment are as follows : 1) As larger amounts of bridging liquid are used, the size of agglomerates are increased until the end of the capillary region of pore filling after which there is an excess of bridging liquid. 2) At the initial stage of the agitation, the size of agglomerates are increased while after a certain agitation period, the size of agglomerates are decreased because destructive force is increased by frequency of collisions between the agglomerates themselves and their adhesion to the walls of the vessel. 3) The diameter of the final agglomerates are determined by a balance between destructive and cohesive forces acting on agglomerates.

심한 척추후측만증 환자의 대퇴골절 복원술을 위한 부위마취 : 증례보고 A case report

김지은,박대용,유시현,강규식,권진형,김천숙,안기량 순천향의학연구소 2004 Journal of Soonchunhyang Medical Science Vol.10 No.2

Kyphoscoliosis is a disease manifested as lateral curvature of spine and accompanying rotation of the vertebrae, resulting in distortion of rib cage. Restrictive lung disease and pulmonary hypertension progressing to cor pulmonale are the major cause of mortality in patients with kyphoscoliosis. We had experienced a successful spinal and caudal epidural anesthesia for the open reduction and internal fixation with plate of fractured femur shaft in two patients with severe kyphosoliosis. We had chosen regional anesthesia as an anesthetic method because of there poor pulmonary function and severe deformities of thoracolumbar spine. We could achieve the adequate anesthetic sensory dermatome level, T_(5) and T_(8), for operation without any significant deterioration of blood pressure and respiration. We recommended that regional anesthesia is a useful anesthetic method for a patients with severe kyphoscoliosis when the operation on hip or lower extremity is required.

Lidocaine 이 흰쥐 해마박편에서 CA 1 추체세포의 활성에 미치는 영향

김형룡,민승기,김대업,오상천,유형근,김은철,고건일,원진숙 원광대학교 생명공학연구소 1995 생명공학연구소보 Vol.3 No.1

LSF의 우선순위 역전을 해결한 실시간 스케쥴링 전략

유한양,김상욱,김대용,김진호 강원대학교 정보통신연구소 1998 정보통신논문지 Vol.2 No.-

LSF scheduling policy involves the Priority Reversal which reverses the scheduling order of real-time tasks. The slack time of the task currently running isn't decreased under LSF. If the task is preempted by a task newly arrived, therefore, its slack time can become longer than those of other tasks with lower priority. This Priority Reversal can make the task with higher priority miss its deadline. In this paper, we propose a new real-time scheduling policy, Consistent_LSF guarantees consistently the scheduling order of current real-time tasks without regard to any new task. The preempted tasks are maintained in a separate stack and are scheduled earlier than the tasks with lower priority. We evaluate the performance of Consistent_LSF through experiments. The results reveal that Consistent_LSF misses deadline less than LSF across all ranges of system load.

1-Arylpyrrole로부터 9-Arylcarbazole의 합성

朴유미,金寅植,李龍均,成大東,金東賢,金倫瑛,鄭大一 東亞大學校附設基礎科學硏究所 1997 基礎科學硏究論文集 Vol.14 No.1

Carbazoles were discovered in anthracene oil of coal tar, and are the parent structure of a number of heterocyclic compounds. Much attention has been paid to carbazole derivatives recently as the materials for semiconductors and photoconductive compounds. Many conventional methods for synthesis of carbazoles were known such as Grabe-Ullmann methods and the Tauber methods. In the course of the investigation for the synthesis of pyrrole derivatives 3. We have found the formation of 9-arylcarbazoles 4 under refluxing glacial acetic acid. Thus we report the results here.

다공질규소 microcavity의 페브리-페로 필터 특성

이춘우,박대규,홍사용,김영유,전종현 公州大學校 基礎科學硏究所 1999 自然科學硏究 Vol.8 No.-

p형 단결정규소 웨이퍼를 15% HF-에탄올 용액에서 양극 산화시켜 다공질규소를 얻는 과정에서 전류밀도에 따라 굴절률이 변하는 다층의 다공질규소층(porous silicon multilayer)을 구현하였다. 그리고 다층의 다공질규소층(I), 다공질규소 발광층, 또 다른 다층의 다공질규소층(II)의 순으로 구성된 porous silicon microcavity(PSM)를 제작하고 그 물성을 조사하였다. PSM 상하에 위치한 다층의 다공질규소층의 단면을 AFM(Atomic Force Microscope)으로 조사한 결과 고굴절률과 저굴절률이 주기적으로 교차하는 층이 균일하게 형성되었으며, 중앙의 다공질규소 발광층도 균일하게 나타났다. 다층의 다공질규소층 및 다공질규소 발광층의 두께를 각각 실효파장의 1/4배 및 2배가 되도록 하였을 때 특정파장의 필터로 쓰일 수 있는 페브리-페로 간섭 필터(Fabry-Perot interference filter)의 특성이 나타났다. 또한 PSM의 발광 스펙트럼은 그 반치폭이 현저히 감소하고 발광의 세기가 크게 증가되는 경향을 보였다. 또한 발광파장을 600 nm로 조절하여 PSM을 구현하고 발광 특성을 관찰한 결과 600 nm 부근에서도 같은 현상이 일어나 발광의 최대 봉우리 파장값을 이동시킬 수 있는 필터로서의 역할이 가능함을 보였다. In the process of obtaining porous silicon by anodizing p-type doped crystalline silicon wafer in 15 % HF-ethanol solution, we obtained porous silicon multilayers which had periodically varying refractive index by the current density. We fabricated the porous silicon microcavity(PSM) which consist of porous silicon multilayers(I), active layer of porous silicon and porous silicon multilayers(II) and investigated its physical properties. The AFM(Atomic Force Microscope) measurement from the cross section of multilayers I and II) shows uniformity of high refractive index and low index layers as well as the active layer. We observed the characteristics of Fabry-Perot interference filter when the thickness of layers was 1/4 and the thickness of active layer was twice of the effective wavelength, which can be used as a filter for specific wavelength. We found the emission characteristic from the PSM, which FWHM(Full Width Half Maximum) was considerably decreased and emission intensity was increased. And as a result of fabricating PSM which consisted of 600 nm in the light emission wavelength and observing the light emission properties, We found out that there was the same phenomenon in 600 nm wavelength and PSM could act as a filter which could shift the maximum of the emitted light.

고속회전 하는 정밀부품을 위한 연질/경질 코팅의 트라이볼로지적 특성에 관한 연구

오진규,정구현,김대은,유제환,김형재 한국공작기계학회 2003 한국공작기계학회 춘계학술대회논문집 Vol.2003 No.-

Recently, rotating elements which use mechanical and electrical systems have been utilized for high speed and accuracy to increase the performance. The most important thing to get a more reliable system is to understand the friction, wear and characteristics which has an effect on various coated surfaces. In this study, the tribological characteristics of various soft/hard materials were investigated by using a custom-built pin-on-reciprocator tester. From the experimental results, it was found that the friction coefficients of the soft material coated surfaces were lower under various normal loads due to thier self-lubricating ability and material transfer to the counter surface.

고식적 검사로 간외 전이를 진단하지 못한 원발성 간암 환자에서 간이식 전에 시행한 전신 FDG-PET의 역할

이원우,류진숙,양유정,김재승,여정석,문대혁,이승규 대한핵의학회 2002 핵의학 분자영상 Vol.36 No.6

목적: 원발성 간암의 치료를 위해 간이식이 시행되고 있으나, 8-54%의 환자에서는 이식 후 원격 전이로 인한 재발이 보고 되고 있다. 이 연구는 간이식 예정인 원발성 간암 환자들에서 고식적인 검사로 진단하지 못한 간의 전이 진단에 있어서 FDG-PET의 유용성을 평가하고자 시행되었다. 대상 및 방법: 2001년 8월 이후 본원에서 간이식을 계획하고 전신 FDG-PET을 시행한 환자 중, FDG-PET 검사 이전에 복부 초음파와 CT, 흉부 x선 검사와 CT, 골스캔 등의 고식적인 검사를 시행하여 전이의 증거가 없거나(n=22), 애매한 이상 소견이 있었던(n=4) 원발성 간암 환자 26명(남:여=23:3), 평균 나이 55.7세)을 조사하였다. FDG-PET에서 양성을 보인 결과는 조직 검사나 임상적인 추적 검사로 전이 여부를 확인하였다. 결과: 고식적 검사에서 애매한 이상 소견이 있었던 환자 4명 중 3명의 6개 병변이 FDG-PET에서 국소 대사 항진을 보였고, 전이로 확인되어 간이식을 시행하지 않았다. 이 중 5 병변들은 의심되지 않았던 부위에서 새로 발견된 것이었다. 다른 1명은 PET에서 음성 소견으로 간이식을 시행하였다. 고식적인 검사에서 전이를 의심할 만한 소견이 없었던 22명 중에서는 5명의 환자에서 7개의 간의 국소 대사항진 병변들이 FDG-PET에서 발견되었는데, 이들 줄 1명은 2 개의 전이 병변이 확인되어 간이식을 시행하지 않았다. 다른 4명의 환자들에서 보인 5개의 국소 대사항진 병변들은 양성병변으로 확인되었고 이 중 3명은 간이식을 시행하였다. 요약하면, FDG-PET으로 4명의 환자에서 고식적인 검사로 찾지 못하던 전이 병변을 찾아 불필요한 간이식을 피할 수 있었다. 모두 17명에서 간이식이 시행되었다. 간의 조직 검사 소견과 비교하였을 때 생존 원발성 간암을 진단하는 FDG-PET의 민감도는 55.6% (5/9)이었고, 특이도는 87.5% (7/8)이었다. 결론: FDG-PET 전신 스캔은 간이식 예정인 원발성 간암 환자들에서 이전에 시행한 고식적인 검사들로 진단하지 못한 전이 병소들을 추가로 진단하여 불필요한 간이식 수술을 줄이는데 기여할 수 있었다. Purpose: Liver transplantation (LT), one of the therapeutic options of primary liver cancer has been suffering from recurrence caused by metastasis in 8-54% of patients. This study was performed to investigate whether FDG-PET is useful for detecting hidden metastasis in LT candidates. Materials and Methods: Twenty-six patients (male:female=23:3, mean age 55.7 year) underwent FDG-PET. Their previous conventional diagnostic studies (CDS) like a abdomen US and CT, chest x-ray and CT, and bone scan were negative (n=22) or equivocal (n=4) for metastasis. Positive FDG-PET findings were confirmed by biopsy or clinical follow-up. Results: Among 4 patients with equivocal metastatic lesions on CDS, 3 had 6 hypermetabolic lesions on FDG-PET, which were confirmed as metastasis and subsequently LTs were cancelled. Of these, 5 lesions were initially negative on CDS. Remained 1 patient underwent LT with a negative FDG-PET result. Among 22 patients without metastasis on CDS, 5 had 7 hypermetabolic lesions on FDG-PET. One of these patients proved to have 2 metastatic lesions, and LT was cancelled. The other 4patients had 5 hypermetabolic lesions on FDG-PET, which were confirmed as benign lesions, and 3 patients of them underwent LT. In summary, FDG-PET was useful in avoiding 4 unwarranted LT by detecting unsuspected metastatic lesions on CDS. A total of 17 patients underwent LT. In comparison with pathology, the sensitivity and specificity of FDG-PET for detecting viable primary liver cancer were 55.6% (5/9) and 87.5% (7/8), respectively. Conclusion: FDG-PET can detect additional hidden metastasis and contribute to reducing unwarranted LT in the patients with primary liver cancer. (Korean J Nucl Med 2002;36;368-80)

관동맥 재개통 후 QTc간격분산의 감소 : 정량적으로 측정한 심근 허혈의 호전 정도와의 연관성 Relationships with the Quantitative Degree of Improvement in Myocardial Ischemia

박상선,최기준,남기병,이철환,홍멸기,박성욱,박승정,신중우,문대혁,김유호 대한순환기학회 2000 Korean Circulation Journal Vol.30 No.8

Local tumor invasiveness is more predictive of survival than International Prognostic Index in stage IE/IIE extranodal NK/T-cell lymphoma, nasal type

Kim, Tae Min,Park, Yeon Hee,Lee, Sang-Yoon,Kim, Ji-Hoon,Kim, Dong-Wan,Im, Seock-Ah,Kim, Tae-You,Kim, Chul Woo,Heo, Dae Seog,Bang, Yung-Jue,Chang, Kee-Hyun,Kim, Noe Kyeong American Society of Hematology 2005 Blood Vol.106 No.12

<P>This study was launched to determine the prognostic significance of local tumor invasiveness (LTI) in 114 patients diagnosed with stage IE/IIE extranodal natural killer (NK)/T-cell lymphoma, nasal type (NTCL). LTI was defined as bony invasion or destruction or tumor invasion of the skin. Complete remission (CR), overall survival (OS), and disease-free survival (DFS) were compared between each group according to LTI, Ann Arbor stage, and International Prognostic Index (IPI). LTI was observed in 23 patients. Using multivariate analysis, factors associated with low probability of CR were the presence of LTI (P < .001), the presence of B symptoms (P = .003), and single-modality chemotherapy (P = .045). The presence of LTI (relative risk [RR] = 8.4, 95% confidence interval [CI] 3.9-17.9; P < .001) and high IPI score (RR = 2.8, 95% CI 1.2-6.8; P = .019) were also predictive of OS. The presence of LTI (RR = 7.3, 95% CI 3.2-16.5; P < .001) was an independently significant factor for reduced DFS. Ann Arbor staging system did not predict CR, OS, or DFS but IPI did have predictive power with regard to survival outcome. LTI is the most important prognostic factor in predicting low probability of CR and reduced OS and DFS in nasal stage IE/IIE NTCL.</P>