1%Cr-Mo-V 강 회전자축의 크리이프 특성과 수명예측에 관한 연구

이치우,장윤석,정순호,조판근 慶南大學校 附設 工業技術硏究所 1986 硏究論文集 Vol.4 No.-

본 연구는 1%Cr-Mo-V강 회전자축의 보다 개선된 크리이프특성을 위한 최적열 처리 조건의 선정과 크리이프 수명을 예측하기 위하여 행해졌다. 실험결과 970℃∼980℃ 퀜칭/660℃∼680℃ 템퍼링의 조합에서 최적크리이프 특성치가 나타났다. 또한 Larson-Miller법 및 Curvelinear Regression법에 의해 1%Cr-Mo-V강 회전자축의 주파단곡선을 구하였다. 회전자축이 530℃에서 연속 작동되며 순수크리이프 변형만을 고려할 때 회전자축의 최고응력 집중부에서의 예상크리프수명은 21.9×105hrs이었다. This study was carried out to find out optimum heat treatment conditions for improved creep properties and to estimate creep life of 1% Cr-Mo-V-steel rotor shaft. The effect of heat treatment on the creep properties of 1% Cr-Mo-V-steel rotor shaft was investigated under the conditions of various heat treatment temperatures. Experimental result shows that the best combination of quenching and tempering temperatures for good creep properties is 970℃-980℃ quenching 660℃-680℃ tempering sequence. A master curve for 1% Cr-Mo-V-steel rotor shaft was obtained by Larson-Miller parameter and curvelinear regression method. Life prediction at the maximum stress concentration points in the rotor was computed about 21.9×10??hours, if the rotor shaft would be continuously operated at 530℃ and be influenced by the effect of creep strain only.

공동주택 연료전지 열교환기의 안전설계 및 특성 분석

RIGUANG CHI, 송의혁, 최재혁, 이동훈, 이석호 충북대학교 산업과학기술연구소 2019 산업과학기술연구 논문집 Vol.33 No.2

본문참조

고립성 폐결절의 조직학적 진단에 있어서 경기관지폐생검의 진단적 가치

김치훈,김정주,왕준호,연규민,김형수,리원연,용석중,신계철 건국대학교 의과학연구소 2002 건국의과학학술지 Vol.12 No.-

Transbronchial lung biopsy(TBLB) is a relatively simple and convenient diagnostic tool in solitary pulmonary nodule(SPN) on chest radiograph, which is cannot be diagnosed through routine tests. To investigate the diagnostic value and diagnostic rate of TBLB according to the variable factor, we analyzed 69 patients with radiologically SPN lesion on chest radiograph which was confirmed histologically. A histologic diagnosis of TBLB was made in 47 of 69 patients(68.1%), in which 26 of 37(70.3%) with malignancy and 21 of 32(65.6%) with benign lesion. There were no significant differences in diagnostic yield according to age, sex and location of the lesion. The diagnostic rate tended to increase with the more than 5 pieces to acquired by TBLB. When the size of SPN was less than 3 ㎝, it cannot be diagnosed. In conclusion, TBLB is a diagnostic procedure with good yield and safety, but percutaneous needle aspiration, transbronchial needle aspiration, and bronchial washing fluid cytology may be a complementary procedure to overcome the limitation of TBLB and get higher diagnostic yield for SPN.

악하선 암의 치료성적과 예후인자

임치영(Chi Young Lim),남기현(Kee Hyun Nam),이잔디(Jan Dee Lee),장항석(Hang Seok Chang),정웅윤(Woong Youn Chung),차인호(In Ho Cha),이창걸(Chang Geol Lee),최은창(Eun Chan Choi),박정수(Cheong Soo Park) 대한두경부종양학회 2005 대한두경부 종양학회지 Vol.21 No.2

Purpose: Submandibular gland tumor is rare, less than 6% of head and neck tumor. The purpose of this article is to analysis the clinical experience and treatment outcomes of malignant submandibular gland tumor, suggesting a guideline of management. Methods: We retrospectively evaluated 26 patients who underwent operation for malignant submandibular gland tumor at Severence hospital between 1986 and 2004. Statistical analysis was performed by Kaplan-Meier method, log rank test, Chi-square test, Fisher's exact test using SPSS v12.0 for Windows. Results: They consisted of 18 males and 8 females whose median age was 47 years(range: 20-71). 10 cases of adenocystic carcinoma, 8 cases of carcinoma ex pleomorphic adenoma, 4 cases of mucoepidermoid carcinoma, 1 case each for acinic cell carcinoma, undifferentiated carcinoma, adeno carcinoma, epithelioid hemangioendothelioma. Sialoadenectomy only was performed in 10 cases(36.5%) and sialoadenectomy with neck node dissection was performed in 16 cases(63.5%). Adjuvant radiotherapy was done in 22 cases(84.6%). 10 year disease free survival rate for malignant submandibular gland tumor was 63.1 % and 10 year overall survival rate for malignant submandibular gland tumor was 70.1%. In univariate analysis, prognostic factors affecting recurrence of malignant submandibular gland tumor was initially papable lateral neck node in physical examination and metastasis of lateral neck node in pathologic confirmation. The prognostic factors affecting survival of malignant submandibular gland tumor was tumor size, TNM stage, recurrence and type of recurrence. Conclusion: In this study, prognostic factors affecting recurrence of malignant submandibular gland tumor was initially papable lateral neck node in physical examination and metastasis of lateral neck node in pathologic confirmation. The prognostic factors affecting survival of malignant submandibular gland tumor was tumor size, TNM stage, recurrence and type of recurrence. To prevent recurrence and to improve survival, early diagnosis and aggressive surgery must be considered.

전정기능검사에서 정상소견을 보이는 어지러운 환자들의 임상적 특징

정원호,방은국,홍성화,이치규,이현석 대한평형의학회 2002 Research in Vestibular Science Vol.1 No.2

공정변수의 변동을 고려한 호감도 함수를 통한 다중반응표면 최적화

권준범,이종석,이상호,전치혁,김광재 한국경영과학회 2005 한국경영과학회지 Vol.30 No.1

A desirability function approach to a multiresponse problem is proposed considering process parameter fluctuation which may amplify the variance of response. It is called POE(propagation of error), which is defined as the standard deviation of the transmitted variability in the response as a function of process parameters. In order to obtain more robust process parameter setting, a new desirability function is proposed by considering POE as well as distance-to-target of response and variance. The proposed method is illustrated using a rubber product case in Ribeiro et al. (2000).

로타바이러스 원내 감염과 지역사회 획득 감염의 비교 연구

유재성,진현주,강호석,오지은 고신대학교 의과대학 2010 고신대학교 의과대학 학술지 Vol.25 No.2

Purpose: This study was performed to investigate the epidemiologic and clinical characteristics of rotaviral infection, the most common nosocomial gastroenteritis. Method: We retrospectively reviewed the records of 983 patients who were diagnosed as rotavirus gastroenteritis from January 2006 to March 2010. We divided them into two groups: group A for community-acquired rotavirus infection (N=810), group B for nosocomial infection (N=173). We investigated the characteristics of both groups. Results: The percentage of nosocomial infection among rotavirus gastroenteritis was 18% in our study. Rotaviral infection in both groups was more common in winter. The average age (±SD) of group A and B was 25.8±23.3 and 17.8±15.7 months old, respectively. The average hospital days (±SD) were 4.3±2.0 days for group A and 9.0±3.5 days for group B. Nosocomial infection symptoms of group B started at 4.6±1.7 hospital days on average. Fever, vomiting, abdominal pain, convulsion, elevation of serum CRP (C-reactive protein) or AST (Aspartate aminotransferase) were observed more common in group A than B. Conclusion: The nosocomial rotavirus infection rate did not decrease as we expected in spite of our effort of strict hygiene control. Nosocomial infection showed more favorable prognosis than community-acquired infection but demanded longer days of hospitalization and more cost.

두 가족의 가족성 모야모야병 환자 4례

구자성,노재규,박성호,이한보,이용석,윤창호,송치성,송재우 대한신경과학회 1998 대한신경과학회지 Vol.16 No.4

페놀분해 효모 Candida tropicalis PW-51의 분리 및 분해특성

김성빈,김치경,김희식,이창호,신기선,권시석,윤병대,오희목 한국미생물생명공학회 ( 구 한국산업미생물학회 ) 1996 한국미생물·생명공학회지 Vol.24 No.6

본 연구는 페놀과 포름알데히드를 포함하는 페놀계수지 산업폐수의 생물학적 처리에 이용할 목적으로 포름알데히드의 존재하에서 페놀분해능이 우수한 효모를 sludge로부터 분리하여, 형태적 및 생리 생화학적 특징을 조사하여 Candida tropicalis PW-51로 동정하였다. 회분식 배양에서 C. tropicalis PW-51의 페놀 분해한계는 2,000 mg/ℓ이며, 58시간내에 완전히 분해하였다. C. tropicalis PW-51은 초기접종량이 9×10 exp (6) cells/㎖, 배양온도는 30℃, pH는 7.0에서 페놀 분해효율이 높았으며, 500~2,000 mg/ℓ의 페놀농도에서 조사된 페놀에 대한 평균 분해율은 페놀 1,000 mg/ℓ에서 45.5 mg/ℓ/h 가장 높았다. C. tropicalis PW-51의 페놀분해시 catechol 1,2-dioxygenase의 활성이 크게증가하므로 ortho-path-way에 의해 페놀을 분해하는 것으로 판단되었다. 따라서, C. tropicalis PW-51는 페놀계 수지 산업폐수의 생물학적 처리에 효과적으로 이용될 수 있는 균주로 사료된다. For the biological treatment of phenolic resin wastewater containing phenol and formaldehyde, a phenol-degrading yeast was isolated from the papermill sludge, and then identified as Candida tropicalis PW-51 according to morphological, physiological and biochemical properties. The strain was able to degrade high phenol concentrations up to 2,000 mg/ℓ within 58 hours in batch cultures. Phenol-degrading efficiency by the strain was maximum at the culture conditions of a final concentration of 9×10 exp (6) cells/㎖ 30℃ and pH 7.0. The mean degradation rate of phenol was highest at 45.5 mg/ℓ/h in 1,000 mg/ℓ phenol from 500 mg/ℓ to 2,000 mg/ℓ phenol. Because the enzyme activity of catechol 1,2-dioxygenase increased in the course of degradation of phenol, it seems that this strain degrades phenol via the ortho-cleavage of benzene ring. The isolate C. tropicalis PW-51 could be effectively used for the biological treatment of phenolic resin wastewater.

위암 환자의 예후인자로서 림프관 정맥 및 신경 침범의 의의

김치호,장석원,강수환,김상운,송선교,Kim Chi-Ho,Jang Seok-Won,Kang Su-Hwan,Kim Sang-Woon,Song Sun-Kyo 대한위암학회 2005 대한위암학회지 Vol.5 No.2

목적: 표준화된 술식으로 위절제술을 시행한 위암 환자를 대상으로 임상병리학적 특성, 특히 암세포의 림프관, 정맥 및 신경 침범 유무가 환자의 예후에 미치는 영향을 확인 하고자 하였다. 대상 및 방법: 1995년 1월부터 1999년 12월까진 만 5년간 영남대학교 의과대학 부속병원 외과에서 위암으로 진단되어 위절제를 시행받은 1,018명의 의무기록을 토대로 후향적 연구를 시행하였다. 통계는 chi-dquare test를 이용하고 예후 인자들은 Cox proportional hazards regression model을 사용한 다변량 분석을 통해 분석하였다. 생존율은 Kaplan-Meier 방법으로 5년 생존율을 구하고 log-rank test로 검정하였다. 유의 수준은 P < 0.05를 기준으로 하였다. 통계처리는 SPSS for Windows (Version 10.0, SPSS lnc, USA) 프로그램을 이용하였다. 결과: 각 임상병리학적 특성에 대한 단변량 분석 결과, 환자의 연령, 종양의 크기 및 위치, Borrmann형, 조직 분화도, 위절제술의 범위, 암의 위벽 침윤도, 림프절 전이 정도, 병기, 원격 전이 유무, 수술의 근치도 등이 유의하였으며, 이상의 유의한 인다들을 다변량 분석한 결과 암의 위벽 침윤도, 림프절 전이, 림프관 침범, 신경 침범 및 수술의 근치도가 독립적 예후 인자로서 유의하였다. 결론: 기존의 TNM 병기 분류법이 병의 진행 상태를 객관적으로 표현할 수 있고 기본적인 예후 인자로서 역할을 하지만, 병리조직학적 검사 소견에서 림프관 및 신경 침범 유무를 확인하는 것은 위암의 예후 판정에 추가적인 정보를 제공할 수 있을 것으로 기대한다. Purpose: Some controversies exist over the prognostic values of lymphatic, venous, and neural invasion in patients with gastric cancer. This study was conducted to confirm the prognostic values of these histopathologic factors in gastric cancer patients who received a gastrectomy. Materials and Methods: Data for clinicopathologic factors and clinical outcomes were collected retrospectively from the medical records of 1,018 gastric cancer patients who received a gastrectomy at Yeungnam University Medical Center between January 1995 and December 1999. A statistical analysis was done using the SPSS program for Windows (Version 10.0, SPSS Inc., USA). The Kaplan-Meier method was used for the survival analysis. Prognostic factors were analyzed by using a multivariate analysis with Cox proportional hazard regression model. Results: Ages ranged from 21 to 79 (median age, 56). A univariate analysis revealed that age, tumor size, location, gross type, depth of invasion, extent of gastrectomy or lymph node dissection, lymph node metastasis, distant metastasis, lymphatic invasion, venous invasion, neural invasion, pathologic stage, histologic type, and curability of surgery had statistical significance. Among these factors, lymph node metastasis, curability of surgery, neural invasion, lymphatic invasion, and depth of invasion were found to be independent prognostic factors by using a multivariate analysis. Venous invasion showed no prognostic value in the multivariate analysis. Conclusion: Neural invasion and lymphatic invasion are useful parameters in determining a prognosis for gastric cancer patients.