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.

폴리아닐린을 이용한 전기변색소자의 제작 및 특성

오응주,이경민,민혜경,노성변,서정선 명지대학교 자연과학연구소 1995 자연과학논문집 Vol.12 No.-

ITO/폴리아닐린/고분자고체전해질/ITO구조의 전기변색소자가 제작되었다.IM p-toluenesulfonic acid 용액내에서 0.7V의 전압하에 potentiostaic method로 아닐린을 전기화학적으로 중합하여 salt form의 폴리아닐린을 ITO glass 위에 deposite시켰다.또한 화학적으로 합성한 base form의 폴리아닐린을 10? torr의 압력하에 진공승화법에 의해 ITO glass 위에 증착시켰다. PEI(polyethyleneimine)과 2-acrylamido-2-methyl-propanesulfonic acid 를 이용하여 고분자 고체전해질을 제조하였다. 제작된 ITO/polyaniline salt/고분자고체전해질/ITO 구조의 전기변색소자는 인가전압 -2.0V~+2.OV의 영역에서 무색에서 푸른색을 나타내었다.Potential pulse를 통하여 측정된 이들 변색소자의 cyvlic number 는 10? 이상으로 나타났고, 응답시간은 50ms로 생기는 전자전이를 통하여 색의 변화를 알 수 있었다. 또한 각각 변색물질로 폴리아닐린 salt 와 base를 사용하여 제작된 변색소자의 경우 I-V곡선은 counter 이온인 SO?-의 발생확률에 따라 다른 곡선을 나타내었다. Electrochromic devices(ECD) with ITO/polyaniline/polymer solid electrolyte /ITO structure were fabricated . In these devices both of poyaniline salt and base forms were deposited onto ITO conducting glass substrate by electrochemical and vacuum sublimation method, respectively, Polymer solid electrolye were prepared by the reaction of polyethyleneimine with 2-acrylamido-2-methyl-propanesulfonic acid . ECDs based on polyaniline salt showed color change from colirless to blue in the range of applied voltage of -2.OV ~+2.0V.Cyclic number and response time of these devices appear to be 10? and 50ms respectively. The color change which is relatd to teh electronic transition by the variation of electron density was observed from the UV/Vis. spectra measurement. I-V curves for ECDs based on polyaniline salt and base repectively shoe different behaviors due to the different degree of contribution of SO?- ion as a counterion for each case.

산 혹은 알칼리 음독시 상부 위장관의 주 손상 부위

장혜영,김성은,정구영,정성애,주미순 대한응급의학회 2001 대한응급의학회지 Vol.12 No.4

Background: It is generally known that while alkali ingestion injures principally the esophagus, acid usually spares the esophagus and damages the stomach mainly. The purpose of this study is to evaluate the most common site of upper gastrointestinal tract injury in acid/alkali ingestion based on endoscopic findings. Methods: We retrospectively evaluated 40 patients who ingested acid/alkali for types and amounts of product ingested, time required to undergo endoscopy, and initial endoscopic findings. Endoscopic lesions were graded according to the criteria suggested by Zagar and were graded at the authors' discretion to compare acid injury and alkali injury. Results: In the acrid ingestion group(n=27), the esophagus injury score was 2.55±1.18, the stomach injury score was 2.62±1.78, and the difference was -0.07±1.13, therefore, no significant difference was present(p=0.939). In the alkali ingestion group(n=10), the esophagus injury score was 1.63 ± 1.50 and the stomach injury score was 2.63 ± 1.20. Stomach injury was significantly more severe than esophageal injury(difference : -1.00± 1.18, p=0.026, Wilcoxon signed ranks test). Conclusion: While no difference exists between injuries of the esophagus and the stomach due to acid ingestion, the stomach was the most common site in alkali injury.

정보기술분야 장애인 직업훈련 및 취업 실태와 과제

육주혜 한국장애인고용촉진공단 고용개발원 2003 장애와 고용 Vol.13 No.1

The growth of Information TechnoIogy(IT) industry has been decreased since the latter half of 2000. However, researchers predict that IT industry will gradually grow in the future. Moreover. IT jobs are spreading to almost all industry areas. The Purposes of the study were (a) to investigate current status of vocational training and employment of people with disabilities in IT and (b) to address future tasks from the data examined. The participants of the study were (a) trainees with disabilities who finished in 2001 from IT programs of about 100 vocational education and training institutes supported by the Korea Employment Promotion Agency for the DisabIed(KEPAD) and (b) trainees with disabilities who completed in 2001 from IT programs of three vocational training institutes affiliated with KEPAD, Data were presented in frequency and percentage. Problems found were lack of basic data from vocational training institutes supported by KEPAD, gaps between job qualification in IT and status of trainees with disabilities, limitation of disability types in the IT training programs, and lack of data on basic academic skills of trainees with disabilities in theinstitutes affiliated with KEPAD. Finally, long-term plans and tasks of the above issues were suggested. 정보기술 산업은 2000년 후반기 이후 급성장을 멈춘고 마이너스 성장을 하고 있으나 향후 지속적인 발전을 할 것으로 전망되고 있다. 또한 이러한 정보기술의 직업은 전 산업에 침투하여 그 직업영역은 더욱 확장될 것으로 예측된다. 본 연구의 목적은 이와 같은 정보기술기술분야에 장애인의 직업훈련과 취업현황을 파악하고 보다 많은 장애인을 안정적이고 수익이 높은 직업으로의 취업연계를 위한 직업훈련에 시사점을 도줄하기 위한 것이다. 연구방법은 한국장애인고용촉진공단 지원 정보기술분야 장애인 직업훈련기관과 공단 산하 직업훈련기관의 수료생을 대상으로 하여 빈도수와 백분율을 조사하였다. 문제점으로 체계적인 기초자료 축적의 부족, 정보기술분야에서의 요구인력 특성과 장애인 훈련생 특성과의 차이, 특정장애유형 집중화, 기초학습능력에 대한 기초자료 미흡이 나타났다. 이들에 대한 장기적 대책방안이 마지막으로 논의되었다.

국내 독감백신 투여현황과 투여 결정에 영향을 주는 요인에 관한 연구

정주연,정선영,곽혜선 이화여자대학교 약학연구소 2005 藥學硏究論文集 Vol.- No.15

This study was aimed to determine influenza vaccination coverage in 2004 in Korean and investigate the factors associated with vaccination. Documentation of vaccination status and baseline data was conducted by a survey using questionnaire sheets. Baseline data and vaccination status were documented on 1465 people out of whom 60.1% received the influenza vaccine. Forth-seven percent of the responders were male; 4% were aged 1-12, 32% were aged 13-39, 32% were aged 40-64 and 32% were aged 65 or older. Twenty-three percent reported a chronic illness, increasing their risk for complications from influenza. Predictors of influenza vaccination were: older age (OR=11.7, 95% CI 5.1-26.8), the presence of chronic illness (OR=2.3, 95% CI 1.1-4.7), previous vaccination(OR=1.8, 95% CI 1.1-2.8), belief that influenza vaccine is effective in preventing influenza (OR=2.5, 95% CI 1.1-5.7) and education level (OR=1.7, 95% CI 1.0-2.7). Immunization rates were much higher in those who will take immunization again (OR=10.4 95% CI 5.5-19.6). Factors affecting the decision on immunization were self-determination (43.6%), public relations (24.1%), recommendation from family members or friends (22.4%) and consulting with health professionals (5.8%). The main reason not to take influenza vaccine was the thought that they are healthy (50.1%). Overall, influenza vaccine coverage was high in those aged 65 or older. Immunization against influenza was influenced more by existing medical problem and belief about th vaccine's effectiveness, rather than sex or residence.

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.