Hot Deformation Behavior and Recrystallization Mechanism in an As-Cast CoNi-Based Superalloy

Yong Guan,Yongchang Liu,Zongqing Ma,Huijun Li,Hongyao Yu 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.6

The hot deformation behavior of as-cast CoNi-based superalloy was investigated by means of hot compression tests. Thecorresponding microstructure evolution after hot deformation was examined by optical microscope, as well as the TEMtechnique. The constitutive equation and processing map as a function of deformation temperature and strain rate were developed. Results show that the efficiency peak of the processing map is 0.38 at the temperature of 1130 °C and the strain rate of0.01 s−1. The discontinuous dynamic recrystallization (DDRX) related to the strain-induced grain boundary migration (SIBM)is the dominant recrystallization mechanism during hot working. Meanwhile, the DRX also occurs by forming sub-grainsaround MC carbides and shear band. In addition, the existence of fine γ′ precipitates are found to retard the recrystallization.

Metarrhizium anisopliae(Metschn.) Sorok이 생산하는 Biopolymer YU-122의 생산과 그 특성

최용석,옥승호,유주현,배동현 한국산업미생물학회 1997 한국미생물·생명공학회지 Vol.25 No.1

토양으로부터 분리한 Metarrhizium anisopliae (Metschn.) Sorok이 생산하는 biopolymer를 정제하여 분석하고, 그의 생산조건을 검토하였다. 탄소원으로 mannitol, 질소원으로는 polypepton을 사용했을 때 가장 많은 biopolymer를 생산하였고 K_2HPO_4 및 CaCl_2를 첨가함으로서 생산량이 더욱 증가하였다. 또한 이 biopolymer를 정제하여 그 분자량과 구성성분을 검토한 결과 Metarrhizium anisopliae(Metschn.) Sorok이 생산하는 Biopolymer YU-122는 분자량이 1.7×10 exp (6)이고, C, H의 구성비가 1:2이며 미량의 N이 검출되었으나, 주 구성성분은 glucose와 galactose의 환원당으로 이루어져있는 전혀 새로운 biopolymer인 것으로 나타났다. To produce biopolymer, Metarrhizium anisopliae (Metschn.) Sorok was cultured in a medium containing glucose 1.0%, sucrose 2.0%, soluble starch 1.0%, yeast extract 0.5%, polypeptone 0.5%, K_2HPO_4 0.1%, MgSO_4·7H_2O 0.02%. The culture broth was centrifuged and the polymer was harvested by adding methanol to the culture supernatant. When three times of methanol was added, the polymer was coagulated and precipitated. Then it was further purifued through successive SK-1B, SA-20P, HP-20 column chromatographies. This polymer was designated as Biopolymer YU-122. C:H ratio of this Biopolymer YU-122 was 1:2 and small amount of N is detected by CHN analyzer. Glucose and galactose are main components of this polymer. Average molecular weight of this biopolymer was 1.7×10 exp (6) by Sepharose 4B gel permeation chromatography. Optimal condition for biopolymer production was investigated. When 5% of mannitol was used as a carbon source, and polypepton as a N source, highest productivity of biopolymer was achieved. C/N ratio as nutrient was also a major factor in polymer production and its optimal ratio was 3.

항정신병약물 사용 중인 정신분열병 환자에서 올란자판으로의 교체 방법에 관한 연구(II) : Comparison of Safety 안전성 비교

안용민,권용실,권준수,민성호,박두병,양문정,소형석,송종호,신윤식,우행원,유범희,이홍석,정한용,한창환,김용식 大韓神經精神醫學會 2002 신경정신의학 Vol.41 No.5

연구목적: 이 다기관 공동임상연구는 사용 중인 항정신병약물을 ’직접 교체 방법’또는 ’시작-감량 교체 방법’중 한 가지 방법으로 올란자핀으로 교체한 후, 안정성 측면에서 두 교체 방법 간의 비교와 교체후의 변화를 관찰하기 위한 것이다. 방법: 국내 13개 병원의 입원 및 외래에 내원한 환자들 중 ICD-10 지단기준으로 정신분열병에 해당되며, 임상적으로 항정신병약물 교체가 필요한 환자를 대상으로 하였다. 두 가지 교체 방법 중 한 가지를 무작위로 피험자에 적용하였으며, ’직접 교체 방법’에 배정된 경우에는 사용중인 항정신병약물을 일시에 중단하고 10㎎의 올란자핀을 바로 투여하였고, ’시작-감량 교체 방법’에 배정된 경우는 10㎎의 올란자핀 투여하고 2주에 걸쳐서 기존 약물을 감량하여 중단하였다. 올란자핀 사용기간은 총 6주이며, 용량은 5∼20㎎ 범위로 제한하였다. 한정성 평가를 위해서 체중, 생명징후, 자발적인 이상반응 복, 실험실 검사 그리고 Simpson-Angus Scale(SAS), Barnes akathisia rating scale(BARS), Abnormal involuntary movement scale(AIMS). Liverpool University neuroleptic side effect rating scale(LUNSERS)등을 이용하였다. 결과: 총 103명의 정신분열병 환자를 대상으로 하였다. 사용한 올란자핀의 용량, 벤조디아제핀의 병용률, 탈락률과 탈락 사유, 자발적인 이상반응 보고, 생명징후, 실험실 검사 그리고 대부분의 부작용 척도 상에서 임상적으로 의미 있는 차이를 두 교체 방법간에 발견하지 못하였다. 다만 AIMS의 감소는 ’직접 교체 방법’군에서 보다 적었고, 항콜린제의 병용률은 ’시작-감량 교체 방법’군에서 보다 많았다. 기저 상태에서 전체 피험자의 SAS와 BARS 점수는 각각 3.5점과 1.8점이었으며 70% 이상의 피험자가 고프로락틴 혈증을 보였다. 올란자핀으로 교체한 후, SAS, BARS, AIMS 점수의 유의한 감소가 있었으며 고프로락틴 혈증을 보인 피험자 분율도 약 30%이하로 감소하였다. 그러나 교체 방법과 상관없이 올란자핀 교체 후 유의한 체중 증가가 있었다. 결론: 이 연구를 통해 교체 방법에 관계없이 비교적 안전하고 용이하게 올란자핀으로 교체 할 수 있음을 알 수 있었다. 그리고 기존 항정신병약물을 올란자핀으로 교체함으로써 일부 부작용들을 줄일 수 있음을 간접적으로 관찰할 수 있었다. 하지만 이 연구는 여러 제한점과 문제점을 지니고 있기 때문에 보다 체계적인 연구를 통해 검정이 필요하리라 생각된다. Objectives: This multicenter clinical trial involving 13 hospital sites compared the safely of switching to olanzapine between ’direct switching method’ and ’start-tapering switching method’. Method: This study included both inpatients and outpatients who fulfilled the criteria for schizophrenia as defined in the ICD-10, and were in need to be appropriate for switching antipsychotics. Subjects were randomly assigned to one of the two switching methods. For ’direct switching method’group, previous antipsychotics were abruptly discontinued and 10㎎ of olanzapine was administered, and previous antipsychotics was gradually tapered for 2 weeks. Olanzapine was used for 6 weeks and the dose was adjusted within the range of 5-20㎎. The safety of switching to olanzapine was measured with vital sings including body weight, adverse events reported spontaneously, laboratory tests, and various scales such as Simpson-Angus Scale(SAS), Barnes Akathisia Rating Scale(BARS). Abnormal Involuntary Movement Scale(AIMS), and Liverpool University Neuroleptic Side Effect Rating Scale(LUNSERS). Results: 103 patients were switched to olanzapine in this study. The comparison between two switching methods did not show any significant difference in the dosage of olanzapine used, the concomitant use of benzodiazepine, the rate and reasons of drop-out, the adverse events, vital signs, laboratory tests, and most scales for measuring side-effects. However, the decrease in AIMS scores was significantly lower in ’direct switching method’ group, and the concomitant use of anticholinergics was comparatively greater in ’start-tapering switching method’ group. At baseline, SAS and BARS scores were 3.5 and 1.8 points respectively, and more than 70% of the subjects showed hyperprolactinemia. After switching to olanzapine, SAS, BARS, and AIMS scores were significantly decreased and the proportion of the patients with hyperprolactinemia was also decreased to less than 30%. However significant weight gain after the treatment of olanzapine was observed regardless of switching method. Conclusion: This study may suggest that switching to olanzapine can be done with relatively high safety regardless of switching methods and olanzapine can significantly decrease some side-effects induced by other antipsychotics.

자기효능감과 수업동기 및 학교생활적응간의 관계 탐색

김용래,유효현 弘益大學校 人文科學硏究所 2002 人文科學 Vol.10 No.-

The purpose of this examination was to find out the relationship among secondary school learners' self-efficacy, instructional motivation and school life-related coping. And in order to achieve the purpose of this examination sampled middle/high school learners in Seoul and other areas. The instruments used for the data collection were 「Self-efficacy Scale」 (Kim, A-Young, 1997), 「School Learning Motivation」 (Kim, Yong-Rae, 2000) and 「School Adjustment Scale」 (Kim, Yong-Rae, 2000). The collected data analysis were performed using SPSS/WIN(11.0V) program, and analysis Mean score(M), Standard Deviation(SD), Zero Order Correlation(r) and Multi-Regression Analysis All statistic values were tested by t-test and F-test in the significant level of p<05. And as for the major findings of this examination, 'self-efficacy', 'instructional motivation' and 'school life-related coping' were significantly positive correlation. And 'self-efficacy' and 'instructional motivation' were significantly positive influences on Korea secondary school learners' 'school life-related coping' respectively.

Metarrhizium anisopliae (Metschn.) Sorok이 생산하는 Biopolymer YU-122의 물리, 화학적 특성

최용석(Yong-Suk, Choi),옥승호(Seung-Ho Ohk),유주현(Ju-Hyun Yu),배동훈(Dong-Hoon Bai) 한국식품과학회 1997 한국식품과학회지 Vol.29 No.1

尿中 鉛 및 蛋白質 排泄量의 補正方法에 關한 實驗的 硏究

兪炳龍,廉容泰,李恩一 고려대학교 의과대학 1994 고려대 의대 잡지 Vol.31 No.1

One of the most important issue in occupational health is to estimate the exposure status or health effects of workers by hazardous chemicals through biological monitoring. The one of the most commonly used tests in biological monitoring to assess the internal doseof a chemical is the measurement of a metabolite or sometimes of the chemical itself in urine. Results from a 24-hour specimen is most representative of average body burden, but it is more difficult to obtain, so it is impractical and more likely to be contaminated. Therefore the analyses are commonly performed on "spot" specimens, and it is necessary to correct the results for the dilution of the urine in order to obtain a reliable estimation by adjustment methods. The most commonly used methods are the specific gravity method and the creatinine method. But these adjustment methods are not reliable satisfactorily, and some other adjustment methods have been suggested by some researchers. This study had been done to develop more reliable adjustment methods of protein and lead measurement in spot urine, and to seek the factors which affect the variability of spot urine. The subjects were 10 workers who had been exposed to lead above TLV. The results were as follows : 1. The coefficients of variation of lead in urine were greater than those of protein both in 21 hour urine specimen and in spot urine specimen. And in the results in spot urine specimens, the coefficients of variation of adjusted concentrations were less than that of unadjusted concentrations of both the protein and lead. 2. The correlation coefficients of urinary lead(adjusted concentration and unadjusted concentration) between in spot urine specimen and in 24-hour urine specimen were 0.6-0.8, and those of creatinine adjusted value between in spot urine specimen and in 24-hour urine specimen were lower in workers who had high level of blood lead(<40㎍/dl) than in workers who had low level of blood lead(>40㎍/dl). 3. The correlation coefficients of urinary protein(adjusted concentrations and unadjusted concentration) between in spot 'urine specimen and in 24-hour urine specimen were 0.6-0.8, and those of creatinine adjusted value between in spot urine specimen and in 24-hour urine specimen were lower in workers who had high level of blood lead(>40㎍/dl) than in workers who had low level of blood lead(<40㎍/dl). 4. The spot urine concentrations adjusted by log-creatinine both of protein and lead were correlated highest to 24 hour urine concentrations in all three adjustment methods such as creatinine adjustment, log-creatinine adjustment and specific gravity adjustment method. 5. The important factors which affect the variation of spot urine were specific gravity in urinary lead, and specific gravity and urinary volume or blood lead and specific gravity in urinary protein. 6. Urinary lead concentrations was not affected seriously by urinary creatinine and urinary volume, but urinary protein concentration was affected largely by urinary creatinine, specific gravity and urinary volume. The urinary protein adjusted by specific gravity was less affected than other adjustment methods. 7. The recommended adjustment method for urinary lead and protein in worker exposed to lead above TLV is log-creatinine method and specific gravity method.

회전익 항공기용 외활형식 착륙장치의 정ㆍ동적 분석에 관한 연구

유용석,이동명,채경덕,오택열 경희대학교 산학협력기술연구원 1996 산학협력기술연구논문집 Vol.2 No.-

It is important to make sure of design's reasonability concerning of structural vibration problems and safety with fulfilling the research and with analyzing the body structures that include the landing gear which has dynamic significant characteristics in helicopter, and to make systematical procedure which obtains engineering data to guarantee the quality of the helicopter that was developed by testing of parts, subsystems and body. In this study, Analysis of landing gear under FAR regulations was attempted, and systematical procedure for static and dynamic characteristics of the landing gear in many subsystems of the helicopter was classified.

英語와 國語의 隱喩比較

劉龍熙 서울産業大學校 1984 논문집 Vol.20 No.1

Languages differ in their structure and expressions and the superiority of a language can be judged by how many different ways of expression it has each concept. The variety of expression comes from the difference of concepts and the style of thinking. Our concepts structure what we perceive, how we get around in the world, and how we relate to other people. And our ordinary conceptual system, in terms of which we both think and act, is fundamentally metaphorical in nature. We can't get along well without metaphor. Metaphor is pervasive in everyday life, not justin language but in thought and action. Here the conceptional differences through metaphorical expressions between Korean and English are dealt in two parts: a) Though images are similar, expressions are different. b)Both concepts and expressions are different. Metaphor is not just a matter of language, that is, of mere words. Human thought processes are largely metaphorical. Therefore how to deal with metaphor as linguistic object is the big problem we face now.

^27Al(p,α pn)핵반응에 의한 무담체 ^22Na 제법 연구

유국현,서용섭,양승대 東國大學校 1998 東國論叢 Vol.37 No.-

A method for the production of no-carrier added(NCA) ^22Na was developed via ^27Al(p, ㄷαpn) nuclear reaction with 50.5MeV protons. the half life of ^22Na is 2.6 years and main γ-energy is 1274.5keV and it is used standard source and sodium catabolism study. The cross-section and thick target yield for the reaction was measured in detail in the energy range of 50.5→20.2MeV in order to determine the optimum conditions for the production of ^22Na. the maximum cross-section for the production of ^22Na was 40.8 mbarn at 43.85MeV. the calculated production yield of ^22Na by 50.5MeV protons on aluminium was 60.9μCi/μAh. The seperation of ^22Na was carried out by ion exchange, precipitation and diffusion. It was found that ion exchange column operation using AG50W-X4 resin was the most efficient method among them.

n-Octane의 개질 반응에서 FAU와 MFI촉매의 탈 알루니늄의 의한 Si/Al비의 영향

유용호,정우진,이철우,오민,박성하,이원묵 한밭대학교 에너지청정기술연구소 2003 에너지청정기술논문집 Vol.3 No.1

제올라이트에서 Si/Al의 조성비는 산도에 큰 영향을 주므로 촉매의 활성 및 선택도도 큰 영향을 받는다. 본 연구에서는 상용화된 FAU 및 MFI 제올라이트를 탈 알루미늄 하여 산도를 변화시킨 후 노르말 옥탄의 개질 반응에서의 촉매특성을 살펴보았다. FAU와 MFI 제올라이트의 탈 알루미늄은 각각 열처리, 수증기 처리, 그리고 질산 처리 등 세 가지 서로 다른 방법으로 수행하였고, 처리된 제올라이트의 물성은 BET, XRD, SEM-EDS, TPD, FT-IR 등을 사용하여 측정하였다. 변형된 제올라이트 촉매들은 본 제조 조건에서 결정성을 그대로 유지하였으며, Si/Al 비는 3에서 30까지 증가하였고 산도는 크게 감소하였다. N-Octane의 개질 반응에서 촉매의 활성은 MFI계 촉매가 FAU계 촉매보다 더 우수하였고, 열처리한 경우가 수증기 처리한 경우보다 활성이 더 크게 나타났다. 수증기 처리한 경우는 열처리한 경우보다 촉매의 활성은 낮았지만 BTX 생성 억제 효과는 더 우수하였고, 산도가 높은 FAU 촉매는 분해반응에서 우수한 활성을 나타내었다. 개질 반응에서 일어나는 분해반응, 탈 수소반응, 그리고 이상화반응 등을 종합적으로 고려하면 열처리에 의하여 변형된 MFI계 촉매가 가장 우수하였다. The catalytic activity and selectivity of zeolites are significantly influenced by the Si/Al ratio, because it has strong effects on the acidity of zeolites. In this research, the catalytic characteristics were investigated by using dealuminated FAU and MFI zeolites as catalysts in the reforming of n-octane. Dealumination of zeolites was carried out in three different processes, i.e., thermal, steam, and nitric acid treatment, and their properties were measured by BET, XRD, SEM-EDS, TPD and FT-IR. The crystalline structure of zeolites were maintained after dealumination. Si/Al ratio was increased from 3 to 30 and the acidity was decreased drastically as Si/Al ratio increases. The catalytic activity of dealuminated MFI zeolite were superior to than that of FAU zeolite. Steam treated catalyst showed higher activity than thermally treated one, but that showed better performance than this in the inhibition of BTX generation. FAU zeolite with high acidity showed good selectivity to the decomposition reaction. In conclusion, thermally treated MFI zeolite show the highest activity in the n-octane reforming, considering all reactions (decomposition, dehydrogenation and isomerization).