Microstructures and Mechanical Properties of Multiphase‑Reinforced In Situ Aluminum Matrix Composites

Ju‑Hye Kim,Jae‑Gil Jung,Eun‑Ji Baek,최윤석,Kwangjun Euh 대한금속·재료학회 2019 METALS AND MATERIALS International Vol.25 No.2

We investigated the microstructures and mechanical properties of multiphase-reinforced in situ aluminum matrix composites(AMCs) prepared with various combinations and contents of Li, Mg, Si, Cu, Zn, Sn, and Ni. The area fractions of thesecondary phases in the as-cast AMCs ranged from 26% to 58%, and the types of secondary phases depended on the alloychemical compositions. The type and amount of secondary phases were more important than matrix strengthening in determiningthe alloy mechanical properties. Composite hardness and compressive stress increased while fracture strain decreasedwith increasing total area fraction of the secondary phases up to 40%. The formation of coarse primary and soft/heavySn-containing phases significantly deteriorated the alloy mechanical properties. Annealing also influenced the mechanicalproperties of the AMCs by changing the microstructures of the secondary phases and Al matrices.

Determination of the optimum porosity for 2‑CEES adsorption by activated carbon fiber from various precursors

Hye‑Min Lee,Byeong‑Hoon Lee,Ju‑Hwan Kim,Kay‑Hyeok An,Soo‑Jin Park,Byung‑Joo Kim 한국탄소학회 2019 Carbon Letters Vol.29 No.6

In this study, we prepared ACFs with a high specific surface area from various precursors (rayon, pitch, and oxidized polyacrylonitrile-based fibers) by a steam-activation technique and investigated the effects of the micropore and mesopore fraction on 2-CEES adsorption behaviors. The activation time was precisely controlled so that the activation yield was in the range of 35–40% to ensure the mechanical properties of the ACFs. The N2 adsorption isotherm characteristics at 77K were confirmed by Brunauer–Emmett–Teller, Barrett–Joyner–Halenda and non-local density functional theory equations. The adsorption capacities of the ACF were measured by breakthrough experiments in the gas phase (750 μg/mL of 2-CEES in N2 flow). The removal efficiency of the ACFs was evaluated and compared with that of AC. From the results, specific surface areas and total pore volume of the ACF were determined to be 1380–1670 m2/g and 0.61–0.82 cm3/g, respectively. It was also observed that various pore characteristics of ACF were found to be dependent on crystallite structure of each precursor. The break through time (C/C0 = 0.10) was in the order of Oxi-Pan-H-9-2 < Saratoga AC < Rayon-H-9-3 < Pitch-H-9-4. This indicates that 2-CEES adsorption capacity could be a function not only of specific surface area or total pore volume, but also of sub-mesopore volume fraction in the range of 1.5–2.5 nm of adsorbents.

Electropulsing Treatment on Enhancement of Electrical Conductivity of Screen-Printed Ag Wire

Ju‑Won Park,Howook Choi,Hwangsun Kim,Simoon Sung,Hye‑Jin Jeong,Il Kim,Jaeseok Gong,Sung‑Tae Hong,Heung Nam Han 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.5

The effect of high electric current density on the sintering of Ag wires manufactured by screen printing is evaluated throughelectrical resistivity analysis and microstructure observation. Different forms (continuous and pulsed) of electric currentwith different current densities are applied to the specimens. Conventional heat treatment is also performed as a controlgroup to examine the athermal effect of electropulsing treatment. Compared to the conventional heat treatment, the resistivityis reduced more under the electropulsing treatment with continuous current for the same temperature and treatment time.Also, the process time of electropulsing treatment can be reduced by applying a pulse form of high density current insteadof continuous current without losing the benefit of enhanced reduction of resistivity. The microstructural observationsobtained from high angle annular dark field scanning transmission electron microscope and a digital precession instrumentclearly show that necking connecting the crystals is formed more firmly under electric current. In addition, the temperaturechange of Ag wire and substrate is calculated according to the change of the resistivity when the electric current is appliedto confirm the reliability.

일개 대학병원에 내원한 원발성 폐암 환자의 인구학적 및 병리학적 특성

주혜원,강경필,김민근,박민석,임현민,이현경,이성순,이영민,김주인,염호기,최수전,이혁표 인제대학교 2006 仁濟醫學 Vol.27 No.-

Background : Recently, the lung cancer mortality rank first in Korea. The prognosis of lung cancer is not good enough with current treatments and multimodality treatments are required. So we are interested in the characteristics of lung cancer patients for better treatment. Methods : We searched lung cancer patients since 1994. Then we collected the data of primary lung cancer patients about the demographic features, histologic types and diagnotic methods. We divided the total period into 2 haves and specific analysis was tried. Results : 1) Total 850 patients were included. 633 (74.5%) were male and 217 (25.5%) were female. 2) The mean age was 65 ± 11 years old. and the peak age was 7th decades. 3) Squamous cell carcinoma(334/850, 39.3%) was slightly more prevalent than adenocarcinoma(302/850, 35.5%). Conclusion : From these results, we expected that older persons will be diagnosed to have lung cancer and adenocarcinoma will be more dominant histologic type with time.

온라인 아동 성착취 근절을 위한 법률개정 방안 : 국제규범과 국내 법령의 비교를 중심으로

정주은,남장현,서지혜 이화여자대학교 법학전문대학원 2020 Ewha Law Review Vol.10 No.-

온라인을 기반으로 한 아동ㆍ청소년에 대한 성착취는 아동ㆍ청소년이 쉽게 유혹되고 어른들에 의하여 발견되는 것이 어렵기 때문에 심각한 피해를 야기한다. 본 연구는 온라인 아동 성착취의 심각성을 인지하고 관련 법령의 개정 방안을 제시하고자 하였다. 우선 우리나라의 아동ㆍ청소년의 성보호에 관한 법률 및 형법 등의 법제 및 현황과 문제점을 살펴보았다. 이를 기반으로 UN아동권리협약 및 제2, 제3선택의정서와 UN아동권리위원회의 권고사항 및 특별보고관의 권고, 팔레르모의정서, 란사로테협약 등 국제규범의 내용을 살펴보고, 해당 국제규범과 해외의 입법례 등과 비교하여 현행 국내 법령의 개선방안을 모색하였다. 연구를 통해 현행 국내 법령의 부적절한 용어 개선이 필요하고, 아동 최선의 이익 원칙에 의한 법 해석 및 적용을 해야 하며, 현행 형법을 활용함과 동시에 그루밍 등 새로운 개념에 대하여 법률에 규정해야 함을 발견하였다. 이와 더불어 성착취물 등에 대한 처벌을 확대하고 형량과 양형기준을 개선하여야 할 필요성도 절감하였다. 현재 국회에 계류 중인 법률개정안을 검토하여 해당 법률안에서 주목할 점과 보완할 점에 대하여 설시하였다. 보론으로는 함정수사의 도입과 제3선택의정서 비준의 필요성을 주장하였다. 이에 비추어 볼 때, 최근 일련의 사건 이후 아동ㆍ청소년의 성보호에 관한 법률이 많은 부분에서 긍정적인 방향으로 개정되었지만 보호의 대상인 아동ㆍ청소년에 대한 범죄이므로 더욱 엄중히 처벌해야할 필요필요가 있는바, 국제규범에 따라 아동ㆍ청소년의 성보호를 위한 개정이 더욱 필요함을 시사한다. Online child sexual exploitation leads to serious damage because children and juveniles are easily tempted but it is hard for adults to find the breeding ground for crime. This study was intended to recognize the seriousness of online sexual exploitation for children and juveniles and to propose the law amendment. First of all, we explored the current status and problems of the legislation, such as the Act on the Protection of Sex in children and juveniles and the Criminal Law in the Republic of Korea. We reviewed the contents of international rules such as the U.N. Convention on the Rights of the Child, the Second and Third Choice Protocol, the recommendations of the U.N. Commission on the Rights of the Child, the recommendations from the CRC and special rapporteur, the Palermo Protocol, the Lanzarote Convention. In accordance with those international rules, we sought the amendment of current domestic law. According to the study, we concluded that the inappropriate terms in the current domestic law should be modified, and the law should be interpreted and applied in accordance with the principle of the best interests of children. Also, new concepts such as ‘grooming’ should be stipulated in the law while utilizing the existing Criminal law. In addition, we were faced with the necessity of expanding punishment for sexual exploitation and improving sentencing guidelines. We reviewed the proposition which was pending in the National Assembly and suggested pros and cons. And then, we complementally argued for the institution of entrapment and the ratification of the Third Choice Protocol.

전시물 기반학습을 통한 미술관 교육프로그램 개발 및 적용 : 한미사진미술관 사례연구

홍혜주 한국문화교육학회 2012 문화예술교육연구 Vol.7 No.2

미술관에서 가장 큰 교육적 자산은 바로 전시물이며, 이를 통해 학습자는 단순히 체험이 아닌, 깊이있게 사고하고 탐구하는 활동이 가능하다. 또한 다양한 시각매체 중 사진은 우리 생활과 밀접한 연관성을 지니고 있다. 이에 본 사례연구에서는 미술관만이 지닌 가장 본질적 특징인 전시물을 중심으로 이뤄지는 학습인 전시물 기반학습과 그 중에서도 사진을 활용한 교육프로그램 사례에 대해 살펴보았다. 프로그램을 통해 학습자들은 이미지를 시각적으로 읽고 이해하는 능력, 자기주도적 학습능력, 협력적 학습능력 등의 학습효과에 대해 긍정적으로 반응하였음을 확인할 수 있었다. 궁극적으로 학습자 중심환경에서 스스로 학습을 구성해나가는 전시물 기반학습에 대한 심도있는 이해를 토대로 다양한 프로그램에 대한 개발과 연구가 필요할 것이다. 아울러 시각문화를 주도하는 중심적 매체인 사진교육 또한 활성화되어 교육적 가치를 새롭게 하길 기대해본다. In museum the largest educational asset is exhibits and learners can experience deeply thinking and searching activities through them. In addition photography among various kinds of visual media is closely related to our lives. This article explores the case study of educational program with photography among other programs based on the use of exhibits in museums. Learners learning effect such as reading and understanding of visual images, self-directed learning and cooperative learning has positively shown through the program. I would like to argue that we need to develop and research educational programs based on understanding that learners are able to make up their programs by themselves in learners friendly environment. Last but not least, I expect photography education which is one of leading visual media has educational value in the future.

췌장의 점액성 낭선암 1예

송현주,김도영,정혜경,남승현,문일환,구혜수 梨花女子大學校 醫科大學 醫科學硏究所 2002 EMJ (Ewha medical journal) Vol.25 No.2

Nowadays increasing use of abdominal ultrasound in routine check-up may increase the detection rate asymtomatic cystic lesions of pancreas. Even through the majority of the cystic lesions of pancreas is pseudocyst, about 10-15% of those lesions are caused by pancreatic cystic tumor. In the pancreatic cystic tumor, especially, mucinous cystic tumor should be exicised due to its malignant potential, while the pancreatic pseudocyst or serous cystic tumon can be observed for a period or treated medically. Several clinical, radiological, biochemical and pathologic guidelines have been developed in order to distinguish among them. Among pancreatic cystic tumors, mucinous cystic adenocarcinoma is very rare and accounts for only 1% of all pancreatic neoplasms. Unlike extremely poor prognosis of pancreatic adenocarcinoma, mucinous cystic adenocarcinoma has an indolent course and shows a good prognosis after its curative resection. Recently we experienced a 69-year-old woman who had a mucinous cystic adenocarcinoma of the pancreas. We report this case with a review of literature.

수영참가 주부회원의 운동지속수행에 영향을 미치는 요인(Ⅱ)

염혜수,박주한 서울여자대학교 자연과학연구소 1997 자연과학연구논문집 Vol.9 No.-

The purpose of the present study was to investigate the factors influencing the adherence. This investigation was based on the social learning theory that the individual characteristics, significant others, and social situation determine the participant's exercise adherence. For this purpose five hundred women were randomly selected from four swimming centers in Seoul. The subjects participated three times a week more than three months. In order to collect the data the items of the questionnaires were selected based on the previous studies(Im, 1987; Yamaguchi, 1987, 1988; Jung, 1991)and were reconstructed through the test of the validity and reliability. The data were analyzed through the one-way ANOVA. The analysis of results provided the following conclusions : The economic level, the degree of the participant's satisfaction for the exercise program, facilities and instructors, participant level of the other swimmers and previous exercise experience made significant influences on the exercise adherence. The other factors did not influence the participant's exercise adherence.

과학적 관찰과 규칙성 발견 활동에서 나타나는 감성단어 유형과 과학 지식 생성력과의 관계

권용주,신동훈,한혜영,박윤복 한국과학교육학회 2004 한국과학교육학회지 Vol.24 No.6

본 연구의 목적은 첫째, 학생들이 과학적 관찰 및 규칙 발견 활동을 수행할 때 나타나는 과학적 감성 단어의 유형과 빈도, 강도를 분석하고, 둘째, 과학 지식 생성력과 과학적 감성지수(ISE)와의 상관관계를 밝히는 것이다. 이를 위해 연구에서는 먼저 선행 연구를 고찰하여 과학적 감성을 정의하고, 효과적인 지식 생성 활동을 위해 겨울눈과 화석 관찰, 씨앗과 암석 분류의 4개의 과제를 개발 하였다. 연구대상은 교원양성대학교 4학년 학생 161명으로 하였다. 피험자들은 각 과제를 수행하면서 인지적 사고과정과 느낀 과학적 감성을 기록하고 형용사 이모티콘 척도 용지에 자신의 감성 강도를 나타내었다. 연구 결과, 관찰 활동에서는 '흥미-수용-사랑-거부'의 순으로 감성유형이 나타났고, 규칙성 발견 활동에서는 '흥미-거부-수용-기대'의 순으로 감성유형이 나타났다. 각각의 감성 단어 빈도는 감성 강도와 통계적으로 상관관계가 있었다. 과학적 감성 빈도(FSE)와 과학적 감성 강도(SSE)를 곱한 과학적 감성지수(ISE)는 과학적 감성능력을 나타내는 하나의 지표로서 과학 지식 생성력과 높은 정적인 상관관계를 가진다. 개별적인 과학적 감성 지수에서는 '수용-사랑-슬픔-흥미'순으로 과학 지식 생성력과 정적인 상관관계를 나타낸다. The purposes of this study were to analyze types of scientific emotion word and to investigate the relationship between the ISE(Index of Scientific Emotion) and the ability of science-knowledge generation in subjects' scientific observation and rule-discovery. The subjects were asked to perform four scientific tasks. The tasks were developed that are suitable for scientific observation and rule-discovery. In performing tasks, the subjects were asked to describe their generated science-knowledge and scientific emotion through self-report questionnaire, performing each task. The strength of their scientific emotion was also measured using adjective emoticon check lists. In subjects' scientific observing, they showed 33.3% of interest emotion which was the biggest, 15.0% of acceptance emotion, and 11.3% of love emotion, respectively. In scientific rule-discovering, types of emotion were shown as 23.8% of interest, 21.5% of disgust, and 10.8% of acceptance, respectively. In addition, ability of science-knowledge generation was significantly correlated to ISE.

아동학대의 발생 현황과 관련변인에 대한 연구

서은주,박혜인 啓明大學校 生活科學硏究所 1994 科學論集 Vol.20 No.-

This study was attempt to survey the recent trends of child abuse and to explore the related variables. The subjects were 436 children in the fifth and sixth grade of the elementary school in Taegu and 436 their parents by coupling-data. The main results of this study are as follows: 1. Significant variables related to the child were child's sex and friendship. And significant variables related to the parents were parental unemployment, child rearing attitudes, violence experience, life satisfaction. Then significant variables related to the home environment were family type, residential style, harmony of the home and martal violence. 2. The most significant variable in all type of child abuse was the variable related to the parents. Additionally marital violence was the most influential variable in all types of child abuse.