On the Strengthening Effects Affecting Tensile and Low Cycle Fatigue Properties of Low-Alloyed Seismic/Fire-Resistant Structural Steels

Jung‑Ho Sim,Tae‑Yeong Kim,Jun‑Yeon Kim,Chi‑Won Kim,Jun‑Ho Chung,Joonoh Moon,Chang‑Hoon Lee,Hyun‑Uk Hong 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.2

In the present study, low carbon ferritic and bainitic steels with different contents of Mo, Ti, and Nb were designed for bothseismic and fire-resistant applications. The microstructure of steels containing 0.3 wt% Mo–0.02 wt% Nb (‘A’ hereinafter)was mainly composed of bainite. By contrast, the microstructure of steels with 0.2 wt% Mo–0.13 wt% Ti (‘B’ hereinafter)consisted of ferrite with a high density of nano-sized (Ti,Mo)-rich MX precipitates. The results showed that the bainiticmicrostructure (‘A’ steel) was quite favorable to high-temperature strength and thermal stability. The yield strength of ‘A’ steelat both room and 600 °C temperatures increased consistently with increasing thermal exposure time (600 °C/200–1000 h),since the precipitation of NbC particles occurred while maintaining bainitic ferrite platelets with a high density of dislocationsduring exposure. In the ‘B’ steel, the formation of nano-sized (Ti,Mo)-rich MX particles was effective to impededislocation movement, leading to excellent plasticity (lower yield ratio) at room temperature. However, their contributionto precipitation hardening was not so much at 600 °C, as compared to the bainitic strengthening. During low cycle fatiguetests at room temperature, the main different feature between the two steels is that the ‘A’ steel showed cyclic softeningwhile cyclic hardening was evident in the ‘B’ steel. The bainitic microstructure showed a better fatigue life due to increasedductility manifested by cyclic softening, by which dislocation cell was developed.

원발성 후복막 점액낭샘암종 1예

지준호,이화정,박승찬,박정철,최은정,서혜진,이원식,이정림,배병조,손경락,이경희 영남대학교 의과대학 2008 Yeungnam University Journal of Medicine Vol.25 No.2

Primary retroperitoneal mucinous cystadenocarcinoma is a very rare malignancy, and little is known concerning its Pathogenesis, optimal treatment, and prognosis. A 29-year-o1d pregnant woman (21 weeks) Presented with abdominal discomfort CA 19-9, CA 125, and CEA were normal Abdominal CT scanning revealed a 19x15x13 cm retropentoneal tumor Exploratory laparotomy and tumor excision were performed. Mucinous retropentoneal implants were removed as completely as possible Histologically, the tumor showed focal areas of capsular invasion, but free resection margins The uterus and both ovaries were normal in appearance No adjuvant therapy was pursued. Six months later, Peritoneal and bilateral ovarian metastases were discovered. Hence, we report the details of this case of primary retroperitoneal mucinous Cystadeno-carcinoma and present a review of the literature.

췌장 선방세포암 1예

이화정,지준호,박승찬,박정철,최은정,서혜진,이원식,이정림,배병조,손경락,이경희 영남대학교 의과대학 2008 Yeungnam University Journal of Medicine Vol.25 No.2

Acinar cell carcinoma is a rare tumor that represents 1~2% of al1 pancreatic cancers. Clinical and radiologic findings are inconclusive in this disease Acinar cell carcinoma is characterized by rapid progression and early metastasis, which lead to its poor prognosis. A 41-year-o1d man was admitted to our hospital for abdominal pain. Abdominal computed tomography (CT) and positron emission tomography-computed tomography (PET-CT) showed a splenic mass, which was being invaded by a pancreatic tail mass and which had increased ^(18)F-fluorodeoxyglucose (FDG) uptake Primary radical distal pancreatectomy and splenectomy were performed. Pathologic findings revealed an acinar cell carcinoma of the Pancreas The patient underwent a total gastrectomy three months later because of gastric recurrence Four months later, multiple hepatic metastases were discovered, and the patient underwent a left hepatectomy During treatment with capecitabine, there was no evidence of tumor progression for 14 months. We report a case of metastatic pancreatic acinar cell carcinoma, which did not progress for an extended period while the patient was being treated with capecitabme.

고랭지 농업 용수확보를 위한 소규모 빗물 이용시설 적용방안

전계원(Kye Won Jun)(全桂元),장창덕(Chang Deok Jang)(張昌德),정승권(Seung Kwon Jung)(鄭承權),전병희(Byong Hee Jun)(田炳熙) 위기관리 이론과 실천 2013 Crisisonomy Vol.9 No.8

최근 기후변화로 지난 2009년과 2012년에 강원도 태백시에서는 가뭄으로 인하여 엄청난 피해를 경험한 적이 있다. 또한 가뭄과 장마의 예측은 점점 더 어려워져 가는 실정이다. 특히 태백시의 87일간의 가뭄과 제한급수에 따른 피해액은 일상생활 134억원, 산업부문 338억원, 공공부문 47억원, 정신적ㆍ사회적 피해 1, 430억원 등 총 1, 949억원에 달하는 것으로 분석되었다. 태백시에 또 다른 큰 문제점은 가뭄으로 인한 고랭지 농업 피해로 인한 손실이다. 고랭지 배추를 생산하는 태백시는 우리나라 유일의 고산지역의 도시로서, 고랭지 농업이 특히 발달한 지역이다. 특히 태백 고랭지 배추는 태백시 농산품의 95.9%, 총 경지면적의 86.6%를 차지하고 있으므로, 배추의 생산성이 태백시 농산품 생산성을 대변한다고 할 수 있다. 본 연구에서는 태백시의 공공기관과 고랭지 농업 지역을 직접 방문하여 소규모 빗물 이용 시설에 대한 현황조사 및 시설의 상태를 점검하고 가뭄발생시 고랭지 농업지역의 피해를 최소화 할 수 있도록 소규모 빗물 이용 시설의 적용 방안 및 효과를 분석하였다. Recently, drought and rainy season are getting more serious. It is getting hard to forecast about drought because drought frequency is getting shorter than before. In 2009(winter) and 2012(summer), Taebaek-si was suffered from enormous damage due to the drought. Particularly, in 2009, cost of damage due to drought and restriction on water supply for 87days were estimated daily life sector 134 billion won, industry sector 338 billion won, the public sector 47 billion won, mental and social damage 1, 430 billion won. The other big issue of Taebaek is decrease in products of Highland Agricultural caused by the drought. Highland chinese cabbage which is the most important agricultural product in Taebaek-si account for 95.9% of all agricultural production of Taebaek-si and account for 86.6% of all gross area. For this reason, chinese cabbage of Taebaek-si is tropical agricultural product and is in charge of supply cabbage definitely. It is considered that if small scale rainwater harvesting system would be installed in highland agriculture area, it could reduce damage of drought at low cost and damage of cabbage would be decrease by system. For this study, We have researched regarding current status of Small Scale Rainwater Harvesting System of Highland Agriculture area in Taebaek-si and have compared with the amount of damage and installation cost in case of drought for the beneficial effects of Small Scale Rainwater Harvesting System, flexible supply of water and damage minimization of agricultural products.

한국인 직무 스트레스 측정도구의 개발 및 표준화

장세진,고상백,강동묵,김성아,강명근,이철갑,정진주,조정진,손미아,채창호,김정원,김정일,김형수,노상철,박재범,우종민,김수영,김정연,하미나,박정선,이경용,김형렬,공정옥,김인아,김정수,박준호,현숙정,손동국 大韓産業醫學會 2005 대한직업환경의학회지 Vol.17 No.4

Background and Purposes: Over the past three decades, numerous studies performed in Korea have reported that job stress is a determinant risk factor for chronic diseases and work disability. Every society has its own culture and occupational climate particular to their organizations, and hence experiences different occupational stress. An occupational stress measurement tool therefore needs to be developed to estimate it objectively. The purpose of this study is to develop and standardize the Korean Occupational Stress Scale (KOSS) which is considered to be unique and specific occupational stressors in Korean employees. Subjects and Methods: Data were obtained from the National Study for Development and Standardization of Occupational Stress (NSDSOS Project: 2002-2004). A total of 12,631 employees from a nationwide sample proportional to the Korean Standard Industrial Classification and the Korean Standard Occupational Classification were administered. The KOSS was developed for 2 years (2002-2004). In the first year, we collected 255 items from the most popular job stress measurement tools such as JCQ, ERI, NIOSH and OSI, and 44 items derived from the a qualitative study (depth interview). Forty-three items of KOSS, in the second year, were retained for use in the final version of the KOSS by using Delphi and factor analysis. Items were scored using conventional 1-2-3-4 Likert scores for the response categories. Results: We developed eight subscales by using factor analysis and validation process: physical environment (3 items), job demand (8 items), insufficient job control (5 items), interpersonal conflict (4 items), job insecurity (6 items), organizational system (7 items), lack of reward (6 items), and occupational climate (4 items). Together they explained 50.0% of total variance. Internal consistency alpha scores were ranged from 0.51 to 0.82. Twenty-four items of the short form of the KOSS (KOSS-SF) were also developed to estimate job stress in the work setting. Because the levels of the subscales of occupational stress were gender dependent, gender-specific standard norms for both the 43-item full version and the 24-item short form using a quartile for the subscales of KOSS were presented. Conclusion: The results of this study suggest that KOSS might be an appropriate measurement scale to estimate occupational stress of Korean employees. Further and more detailed study needs to be conducted to improve the validity of this scale.

정신분열병에 대한 리스페리돈의 효과 및 안정성

이민수,김용구,김영훈,연병길,오병훈,윤도준,윤진상,이철,정희연,강병조,김광수,김동언,김명정,김상훈,김희철,나철,노승호,민경준,박기창,박두병,백기청,백인호,손봉기,손진욱,양병환,양창국,우행원,이정호,이종범,이홍식,임기영,전태연,정영조,정영철,정인과,정인원,지익성,채정호,한상익,한선호,한진희,서광윤 大韓神經精神醫學會 1998 신경정신의학 Vol.37 No.1

연구목적 : 본 시험의 목적은 임상시험 시작전에 연구자들을 대상으로 PANSS Workshop을 통하여 PANSS, ESRS에 대한 국내에서의 표준화 작업을 구축하고 새로운 정신병 치료제인 리스페리돈의 효과와 안정성을 재확인하여 리스페리돈 사용에 대한 적정화를 이루는데 있다. 연구방법 : 1996년 4월부터 1996년 9월까지 국내 39개 대학병원 정신과에 입원중인 혹은 증상이 악화되어 입원하는 정신분열병 환자 377명을 대상으로 다시설 개방 연구를 시행하였다. 1주일간의 약물 배설기간을 가진후, 리스페리돈을 8주간 투여하였고, 기준점, 1주, 2주, 4주, 그리고 8주후에 평가되었다. 용량은 제1일에는 리스페리돈 1mg씩 1일 2회, 제2일에는 2mg씩 1일 2회, 제3∼7일에는 3mg씩 1일 2회 투여하였다. 이후 환자의 임상상태에 따라 임의로 증량할 수 있으며, 최대 일일 16mg을 초과하지 않도록 하였다. 추체외로 증상을 조절하기 위한 투약을 허용하였다. 임상증상 및 부작용의 평가는 PANSS(Positive and Negative Syndrome Scale), CGI(Clinical Global Impression) 그리고 ESRS(Extrapyramidal Symptom Rating Scale)을 사용하였다. 연구결과 : 377명중 343명(91%)이 8주간의 연구를 완결하였다. 치료 종결시점인 8주후 PANSS 총점수가 20% 이상 호전된 경우를 약물 반응군으로 정의할때, 약물반응군은 81.3%였다. 리스페리돈에 반응하는 예측인자로는 발병연령, 이전의 입원 횟수, 유병기간이 관련 있었다. 리스페리돈은 1주후부터 PANSS양성, 음성, 및 일반정신병리 점수상에 유의한 호전을 보여 효과가 빨랐다. CGI의 경우도 기준점에 비해 1주후부터 유의한 감소를 나타내었다. ESRS의 경우, 파킨슨 평가점수는 기준점과 비교해 투여 1주, 2주, 4주후 유의하게 증가되었다가 8주후 기준점과 차이가 없었다. Dystonia 평가점수는 1주후만 유의한 증가를 보였으며, dyskinesia 평가점수는 유의한 차이가 없었다. 혈압, 맥박수의 생명징후 및 일반 혈액학 검사, 생화학적 검사, 심전도 검사에서 유의한 변화는 없었다. 결 론 : 이상의 다시설 개방 임상 연구를 통해 리스페리돈은 정신분열병 환자에서 양성증상뿐만 아니라 음성증상 및 전반적인 증상에도 효과적인 것으로 사료된다. 보다 명확한 평가를 위해서는 다른 항정신병약물과의 이중맹검 연구가 필요할 것으로 생각되며, 또한 장기적 치료에 대한 평가도 함께 이루어져야 하겠다. Objective : The purpose of this study was to investigate the efficacy and safety of risperidone in the treatment of Korean schizophrenic patients. Method : This multicenter open study included 377 schizophrenic patients drawn from 39 university hospitals. After a wash-out period of 1 week, the schizophrenic patients were treated with risperidone for 8 weeks and evaluated at 5 points ; at baseline, and 1, 2, 4 and 8 weeks of treatment. The dose was increased from 2mg/day(1mg twice daily) to 6mg/day(3mg twice daily) during the first week and adjusted to a maximum of 16mg/day over the next 7 weeks according to the patient's clinical response. Medication to control extrapyramidal symptoms was permitted. The psychiatric and neurological status of the patients was assessed by PANSS, CGI, and ESRS scales. Results : 343(91%) of 377 patients completed the 8-week trial period. Clinical improvement, as defined by a 20% or more reduction in total PANSS score at end point, was shown by 81.3% of patients. The predictors of response to risperidone were associated older age, shorter duration of illness, fewer previous hospitalization. Risperidone had rapid onset of action ; a significant decrease of the total PANSS and three PANSS factor(positive, negative, general), and CGI was already noticed at the end of first week. For the ESRS, parkinsonism rating scores were significantly increased until week 4 comparing with baseline. Dystonia rating scores were significantly increased until week 1, and dyskinesia rating scores were not significantly changed during the study. Laboratory parameters including vital sign, EKG, hematological, and biochemical values showed no significant changes during the trial. Conclusions : This study suggests that risperidone is generally safe and effective against both the positive and negative symptoms in our group of patients.

흡착 우라늄 이온의 전기 탈착거동

정종헌,원휘준,최왕규,김계남,이성호,오원진 한국공업화학회 2003 응용화학 Vol.7 No.1

Liquid wastes containing uranium ions in high concentration of chemical salts havebeen treated by electrosorption on a activated carbon fibers(ACFs) electrode. Effectiveuranium (VI) removal is accomplished when the potential is -0.5V(vs. Ag/AgCl) ormore negative. For a feed concentration of 100mg/1, the concentration of U(VI) in thecell effluent is reduced to less than 1mg/1, and electrosorption capacity over 500mg/uranium/gACF is reached. The adsorbed uranium can be desorbed up to 99%for 20h by passing a 1.9N NaCl solution at pH 3 through the cell and applying a potential of +1.2V. The amount of desorbed uranium increased as the solution pHwas lowered and the applied potential increased.

복막투석복막염 환자에서 발생한 창자벽공기증 1예

정선영,나지훈,최윤정,고성애,조규향,박종원,도준영,윤경우 영남대학교 의과대학 2009 Yeungnam University Journal of Medicine Vol.26 No.1

Peritonitis is a serious problem in patients undergoing peritoneal dialysis. Rarely pneumatosis intestinalis can occur as a complication of this infectious process. Pneumatosis intestinalis is a potential life threatening condition with a challenging management. The mortality of peritoneal dialysis patients with pneumatosis intestinalis secondary to mesenteric ischemia is almost 100%. We describe a rare case of pneumatosis intestinalis in a peritoneal dialysis patient who developed Staphylococcus aureus peritonitis which was initially treated with appropriate antibiotics. Since initial response to therapy was not achieved, an abdominal computerized tomography was done which revealed a pneumatosis intestinalis. A laparotomy was performed and small bowel necrosis was seen. A segmented resection with ileostomy, jejunostomy was done. Though surgical treatment was performed, the patient died in 2 weeks after admission. Pneumocystitis intestinalis in peritoneal dialysis peritonitis is a uncommon complication which requires prompt evaluation to rule out mesenteric ischemia as it carries a high mortality and its management will be surgical.

반하(Pinellia ternata)가 랫드의 수컷 생식기계에서 3β-HSD,SGP-2 및 AR 유전자 발현에 미치는 영향

연정민, 백인정, 김윤배, 노재섭, 황방연, 김순선, 조대현, 이범준, 윤영원, 남상윤 충북대학교 동물의학연구소 2005 Journal of Biomedical and Translational Research Vol.6 No.2

본문참조

Self-injection locking 방식을 이용한 2.4GHz ISM대역 수신기의 국부 발진기용 VCO 설계 및 제작

정원재,전계석 경희대학교 레이저공학연구소 2004 레이저공학 Vol.15 No.-

This paper suggests that the jitter of the VCO is reduced to improve the phase noise using a microstrip meander line structure. Also the phase noise is improved by using a self-injection locking method which the output signal of the VCO is feedback. A phase noise is an important factor to decide a sensitivity and selectivity of an entire system. The phase noise of the VCO using a self-injection locking method is -85.19dBc/Hz at the l0kHz offset from 1.08GHz carrier with 2V tuning voltage and -98.62dBc/Hz at the l0kHz offset from 1.18GHz carrier with 8V tuning voltage.