Effect of Al and Mg Contents on Wettability and Reactivity of Molten Zn–Al–Mg Alloys on Steel Sheets Covered with MnO and SiO2 Layers

Joo‑Youl Huh,Min‑Je Hwang,Seung‑Woo Shim,Tae‑Chul Kim,Jong‑Sang Kim 대한금속·재료학회 2018 METALS AND MATERIALS International Vol.24 No.6

The reactive wetting behaviors of molten Zn–Al–Mg alloys on MnO- and amorphous (a-) SiO2-covered steel sheets wereinvestigated by the sessile drop method, as a function of the Al and Mg contents in the alloys. The sessile drop tests werecarried out at 460 °C and the variation in the contact angles (θc) of alloys containing 0.2–2.5 wt% Al and 0–3.0 wt% Mg wasmonitored for 20 s. For all the alloys, the MnO-covered steel substrate exhibited reactive wetting whereas the a-SiO2-coveredsteel exhibited nonreactive, nonwetting (θc > 90°) behavior. The MnO layer was rapidly removed by Al and Mg contained inthe alloys. The wetting of the MnO-covered steel sheet significantly improved upon increasing the Mg content but decreasedupon increasing the Al content, indicating that the surface tension of the alloy droplet is the main factor controlling its wettability. Although the reactions of Al and Mg in molten alloys with the a-SiO2 layer were found to be sluggish, the wettabilityof Zn–Al–Mg alloys on the a-SiO2 layer improved upon increasing the Al and Mg contents. These results suggest that thewetting of advanced high-strength steel sheets, the surface oxide layer of which consists of a mixture of MnO and SiO2,withZn–Al–Mg alloys could be most effectively improved by increasing the Mg content of the alloys.

Investigating the Empirical Aspects of Communication Strategies

Uhm, Chul Joo 대한언어학회 2000 언어학 Vol.8 No.1

Uhm, Chul Joo. 2000. Investigating the Empirical Aspects of Communication Strategies. Linguistics 8-1, 353-377. This critical review on communication strategies (CS) characterizing the second language learners' communication problems will be concerned with some important empirical research that we should find useful when investigating the mechanism for processing that will explain how learners produce the utterances, and why they choose the solutions they do. Included are the summary of various typologies on which these empirical studies are based and the categorized review of the studies from reduction CS, compensatory CS and process approach perspectives. (Chonnam National University)

Problems of Assessing L2 Communicative Performance

Uhm, Chul Joo 대한언어학회 1996 언어학 Vol.4 No.-

Uhm, Chul Joo. 1996. Problems of Assessing L2 Communicative Performance. Linguistics 4, 95-108. Evaluation is an especially problematic aspect of proficiency-oriented language pedagogy. Here, therefore, I briefly review a few important problems at thee levels that seem to cause difficulties in the design, development and use of communicative tests such as: i) lack of theory of communication and of a description of language in use, ii) the loose definition of 'communicative proficiency" and the unclear idea of what to test, and iii) the search of a new way for achieving reliability. In this review we find out that the shift of focus in language teaching from language form to use is an exciting and promising development; however, we need to make endless efforts to develop the possibility of alternative assessment as valid and reliable procedures for this change. (Kwangju University)

한국과 영국의 학교장자격 연수과정 비교

주철안,김혜진 부산대학교 과학교육연구소 2012 교사교육연구 Vol.51 No.3

이 연구는 우리나라의 현행 교장자격연수 실상을 분석하기 위해 공식적인 교장양성프로그램이 가장 발달되어 있는 영국의 사례와 비교ㆍ분석하였다. 구체적으로 양국의 교장자격연수 배경, 자격요건 및 선발, 연수프로그램의 구성 및 내용, 연수평가 및 결과활용, 연수기관 평가 등의 제 영역에서 공통점과 차이점을 분석하였으며, 이를 통해 우리나라의 교장자격연수제도의 개선을 위한 시사점을 도출하였다. 주요 연구결과는 다음과 같다. 첫째, 한국은 개방형 공모교장의 경우를 제외하고 경력 등에 근거한 평정점수, 영국에서는 지원서 및 추천서 평가에 따라 자격자를 선발하여 연수 대상자를 선정하였다. 둘째, 연수과정의 구성에 있어서 우리나라의 자격연수는 정책연수, 시도연수와 본연수의 총 192시간으로 이루어지는데 비해서, 영국의 NPQH는 총 4가지 단계로 구성되어 교육기간만 4~12개월 정도가 걸린다. 셋째, 연수과정의 내용은 양국이 모두 다양한 과정을 제공하지만, 영국의 경우 개별화 맞춤프로그램이 가능해서 연수자의 필요에 부응하여 이루어지고 있다. 마지막으로 평가 및 결과 활용을 보면, 우리나라의 경우 자격연수를 이수하면 자격증이 주어지고 교장 임용시 순위를 정하는 척도로 활용되지만, 영국은 엄격한 질적 평가를 통해서 자격증 수여 여부를 평가자가 결정할 수 있다. 연구결과를 통해 도출한 주요 시사점은 다음과 같다. 교장자격 연수의 목표로서 성공적인 학교경영을 위해 필수적인 학교장의 역량이 명확하게 제시되어야 하며, 연수과정 또한 이와 유기적으로 연계하여 설계되어야 한다. 교육과정은 개인의 개발 요구를 고려한 맞춤형 프로그램이 되어야 한다. 마지막으로 연수 평가는 연수자의 전문성 개발에 관해 양적ㆍ질적으로 평가할 수 있는 방식으로 수행되어야 하며, 연수기관의 효과성 향상과 지속적인 개선을 위해서 연수기관평가체제가 구축되어야 한다. This study analyzes the current status of the principal qualification system in Korea, and compares it with the system in England. Different aspects of the systems in the two countries are analyzed, including the overview, requirements and the candidate selection process, as well as curriculum, assessment, and the certification process. The results are as follows. First, the pre-service education system in Korea works out to a total of 192 hours, comprising pre-training and main training sessions. On the other hand, NPQH in England has four different levels lasting about 4 - 12 months. Both systems provide various curricula, but NPQH can be customized according to the trainee’s needs. Upon completion of the curriculum, candidates in Korea are assessed quantitatively before being certified and assigned to individual schools, while the ones in England are assessed rigorously and qualitatively in order to be certified. The findings of this study suggest the followings. First, the required competencies of school principals should be clearly stated as the goal of the pre-service education system of school principals. Second, curricula should be customized according to the individual’s needs. Third, the assessment should be done in both quantitative and qualitative ways for a proper perspective of the candidate’s development.

균 spheroplast 및 large unilamellar vesicle의 식물 protoplast로의 도입

주충노,강철호,이희봉 연세대학교 자연과학연구소 1987 學術論文集 Vol.19 No.-

A. tumefaciens의 식물 protoplast로의 도입을 확인하는 방법으로 방사성 인산(Na_2H^32PO_4)을 함유한 0.8% nutrient broth에서 증식한 Agrobacterium tumefaciens C58를 사용하여 방사성 spheroplast와 방사성 Ti plasmid encapsulated liposome을 만들어 Danus carota protoplast로의 도입을 시도한 결과 다음과 같은 실험 성적을 얻었다. 1. A. tumefaciens에서 추출한 Ti plasmid를 Reverse Phase Evaporation 법으로 phosphatidyl-choline, stearylamine과 함께 Ti plasmid encapsulated liposome을 제조한 결과 17%의 Ti plasmid가 liposome안으로 편입되었다. 2. 방사성 Ti plasmid encapsulated liposome과 Dacus carota root protoplast를 polyethyleneglycol-Ca^2+법으로 처리한 결과 introduction frequency는 38%이었다. 3. A. tumefaciens C58의 spheroplast와 Dacus carota root protoplast를 polyethyleneglycol Ca^2+ 법으로 처리한 결과 introduction frequency가 47.6%였다. 4. 본 연구에서 얻은 실험결과로 부터 liposome법, spheroplast법 모두 Ti plasmid의 식물 protoplast로의 도입은 용이하게 일어나는 것으로 생각된다. It was attempted in the present study to prepare radioactive Ti plasmid to identify the introduction frequency of Ti plasmid encapsulated liposome into Dacus carota root protoplast. Agrobcterium tumefaciens C58 was cultured in 0.8% nutrient broth containing radioactive phosphoric acid(H_3^32PO_4) and the radioactive Ti plasmid wad isolated. Radioactive Ti plasmid was encapsulated into phosphatidyl choline-stearylamine liposomes by reverse phase evaporation technique and the encapsulation frequency was found to be about 17%. Radioactive Ti plasmid encapsulated liposome and Dacus carota root protoplast was treated by polyethyleneglycol Ca^2+ procedure. The introduction frequency was 38%. The spheroplast of A. tumefaciens C38 was prepared from the bacteria cultured in 0.8% nutrient broth containing radioactive phosphoric acid using lysozyme. As much as 47% of the spheroplast were found to be introduced into Dacus carota protoplast.

학과 중심 행정체제 수립을 위한 행정인력 배치에 관한 연구

주철안 釜山大學校 敎育硏究所 1995 敎育硏究 Vol.5 No.1

This study is to analyze job content and work load of administrative staff of Pusan National University in order to raise the efficiency of the university administration. The research adopted the daily job description method. For the daily job analysis, offices at three levels, university, college, and department, were selected. Administrative staff from those offices reported their work load for a month. Contained in the reports were the description and time length of the job. In addition, a survey method was adopted to examine subjects' view of the job. There were 332(52.78%) respondents out of 629 employees. 1. The major findings from survey questionnaires to Pusan University administrative staff are as follows. 1) Average daily work load is about 472 minutes which includes 300 minutes for dealing with formal letters, 102 minutes for meetings and field sites. 2) Average number of official trips out of city is 4.4 times per year. The average length of official trips is 3.88 days. Average number of official trips within the city is 3.023 times per month. The average length of official trips is 5.162 hours. 3) 55% of respondents worked at night or at home because of work load. The overwork averaged 4 days per month. 4) 70% of respondents pointed out that work load changed over the months. While work loads were high in December, January, February, and March, work loads were low in May, June, July, August, and April. University work was centered around the end as well as the beginning of the year because of university entrance examinations and preparation of the new semester. 5) 60% of respondents noted that the deadline of dealing with official letters is short. The three steps of the official letter procedure could be reduced for time saving. 6) Administrative staff favored the ideas of a management information system using computer, manpower rearragement based upon job anaysis, providing educational opportunity for job performance, and change of work procedures (from three steps to two steps, university office and department office) for administrative efficiency. 7) For efficiency of administration 48% of respondents favored strengthening of department offices instead of the reorganization of the university administration offices. For the support of department offices respondents favored a computer management system(52%) and assignment of administrative staff to department offices (36%). 2. The findings from job analyses using daily work load descriptions are as follows. I) the university wide office At H office the number of administrative manpower has been reduced from 15 in 1992 to 10 in 1995. It was found that there were still extra manpower of 0.28 person at H office. Work load at middle and upper level of difficulty had increased. This fact should be noted when considering manpower rearrangement. 2) the college office At S office there were 1.37 extra manpower which were distributed evenly among the levels of work difficulty. 3) department offices It was found that there were 0.813(G department), 0.479(0 department), 0.516(K department) in extra manpower. Compared with other offices, there were more extra manpower in department offices than in H university wide office, but fewer than in S college administrative office. 3. The research results suggest that the assignment of support staff to deparment offices as well as computer based management system is very important because of rapid increasing work load in department offices. The results also suggest that the rearrangement of support staff from college administrative office to department office would be desirable. Finally, at the university wide offices the support staff should be rearranged considering the work load of each office.

현훈 환자 Neuron Specific Enolase의 임상적 의의

김원주,김선곤,유철형,김원찬,김용덕,최영철,이명식 대한신경과학회 1998 대한신경과학회지 Vol.16 No.4

만성폐색성 폐질환과 위식도 역류질환과의 관계

김영철,오재희,변주남 朝鮮大學校 附設 醫學硏究所 1992 The Medical Journal of Chosun University Vol.17 No.1

In order to investigate the factors influencing the chronic obstructive pulmonary disease (COPD), especially for the relationship between gastroesophageal reflux disease(GERD) and COPD, a case-control study was conducted in chonnam area. Data were obtained from hospital records and interview survey from Jan. to Dec. 1991. Final 64 cases with COPD(case group) were compared with 83 cases of normal lung(control group 1) and 45 cases of non-COPD lung disease (control group 2) The results were as follows. 1. Smoking status, history of adulthood pulmonary infection and frequent history of URI, socioeconomic status and GERD were significantly different between COPD group and control group 1. 2. Drinking status, physical height of the subjects and GERD were significantly different between COPD group and control group 2. 3. If control group 1 was used, odds ratio of GERD and COPD was 5.68(95% confidence interval, 95% CI: 2.59-12.45) and 4.81(95% CI: 1.89-10.53) when adjusted by age and smoking status. 4. If contol group 2 was used, odds ratio of GERD and COPD was 4.22(95% CI: 1.69-10.56) and 4.59(95% CI: 1.64-12.86) when adjusted by alcohol and adulthood respiratory infection status. 5. This results suggested that GERD might play a causative role in the development of COPD.

어머니의 성격유형과 유아의 언어능력과의 관계

김옥출,박주성 조선대학교 학생지도연구소 2001 生活指導硏究 Vol.21 No.1

韓ㆍ日學生間의 身體構成 變化 패턴에 관한 比較硏究

梁株哲,李鐵煥 경남대학교 교육문제연구소 1997 敎育理論과 實踐 Vol.7 No.2

The subjects of this study were 2,369 primary, middle and high school boys and girls of Korea(1,002) and Japan(1,367). 6 to 17 years old. The purpose of this study was to compare age-related changing pattern of body structure and body composition of Korean youth with those of Japanese, and to analyze the differences Korean and Japanese youth. The results are as follows : 1. Body height of Japanese boys was significantly higher than that of Korean boys the case of 12 fears old and older, and for the case of girls, 11 years old and older. 2. Body weight of Japanese youth was higher than that of Korean in the case of 11 years old and older. 3. Triceps skinfold thickness of Korean and Japanese couth was the highest among four regions, Calf followed it and suprailiac was the lowest in the case of boys. However, in the case of girls, subscapular was the lowest. 4. Total skinfold thickness of Japanese youth was higher than that of Korean in all age groups except girls of high school period. 5. Body density of Korean youth was higher than that of Japanese in all age groups except in the case of girls of high school period. 6. % Fat of Japanese couth was higher then that of Korean in all age groups, but LBM was the opposite case of % Fat. 7. Ponderal Index of Korean youth was higher than that of Japanese from 6 to 11 fears old. However, Starting from 12 years and older, Ponderal Index of Japanese was higher than Korean. As they grew older, differences in values of Ponderal Index gradually expanded for the case of girls.