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.

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.

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.

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.

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.

성인 중증장애인 직업능력개발의 요소와 과정

육주혜 국립특수교육원 2003 특수교육연구 Vol.10 No.2

직업능력을 개발하는 일은 중증장애인의 삶을 향상하고 의미 있는 사회참여의 기회를 확대하는데 중요한 역할을 한다. 이러한 중증장애인 직업능력개발의 체계적인 정립을 위해 장기간에 걸친 질적연구와 사례조사를 통해 우리나라 장애인 전용 직업훈련기관의 현황, 직업훈련의 구체적 구성요소, 진행과정을 파악하였다. 직업훈련의 구성요소로는 직업훈련의 목적, 기능수준에 따른 직업훈련, 팀구성 전문가, 훈련과정 훈련환경이 포함되는 것으로 나타났다. 이러한 요소들을 기반으로 한 직업훈련의 과정으로는 직업훈련에서 특정 직업분야 동향 파악, 평가를 통한 직업훈련 대상 결정, 개별훈련생의 능력을 고려한 직업훈련, 훈련결과 분석 및 feedback, 수료 후 지도 및 feedback과 함께 직업재활 서비스의 적극적인 지원을 필요로 하는 것으로 조사되었다. 이러한 결과들에 더한 향후 중증장애인 직업능력개발의 방향이 논의되었다. Vocational competency development is essential for individuals with severe disabilities to improve their quality of life and to expand opportunity of meaningful participation in the society. This study examined vocational training institutes for people with disabilities and specific components and process of the vocational training system, through longitudinal qualitative research and case study. The result presents essential components and systematic process of the vocational training for people with severe disabilities. That is, components of vocational training for people with disabilities consist of a purpose of the vocational training, vocational training by individual abilities, team members. training process, and training environment. Process of vocational training includes identifying trends in specific occupation, reviewing vocational evaluation data and interviewing individuals with disabilities to place in specific vocational training programs, providing individualized vocational training. analyzing the results of the training and using the feedback for next training, and performing follow-up service and getting feedback. Throughout this process, vocational rehabilitation services also should be provided. Finally, practical issues for addressing systematic vocational training for people with severe disabilities are discussed.

방사선 치료를 받는 암 환자들의 사회적 지지와 삶의 질과의 관계

정주희,류소연,윤혜은,남택근,오윤경,안현옥,박계남,이영선 朝鮮大學校 附設 醫學硏究所 2002 The Medical Journal of Chosun University Vol.27 No.2

Objective : This study was performed to investigate the relationship between social support and quality of life among cancer patients receiving radiation therapy. Matehals and Methods : The data were collected from 98 patients, who were receiving radiation therapy at two university hospitals located in GwangUJu, used by structured questionnaire. For statistical analyses of the association between quality of life and various characteristics, data were analyzed using t-test, ANOVA, Pearson 's correlation, and multiple regression analysis. Results: 1. There were 56(57.1%) males and 42(42.9%) females. Age ranged from 21 to 82 years. The primary sites of cancer were gastrointestinal tract (24.5%), lung (23.5%), breast (21.4%), and head and neck (11.2%) in order. 2. The mean scores of social, family, and medical support were 4.30 0.58, 4.49 0.78, 4.11 0.65, respectively. The score of quality of life was 5.83 1.63 (range: 1.95 ~ 9.05). 3. An analysis of the association between several factors of patients and quality of life showed that the statistically significant factors were age, the presence of distant metastasis, family support, medical support and social support. 4. As a result of the multiple regression analysis, only social support was significant (β=0.932, P=0.02) with quality of life, but age and presence of distant metastasis were not significant. Conclusion : This suggests that quality of life in cancer patients could be improved by strengthening the social support which consists of family and medical support. Further study would be necessary to evaluate separately several aspects of quality of life among cancer patients.

PPV 공중합체의 합성 및 발광특성

민혜경,이경민,한동제,박성진,오응주 명지대학교 자연과학연구소 1997 자연과학논문집 Vol.16 No.-

Blue light emitting PPV [poly (p-phenylene vinylene)] copolymers soluble in common organic solvents are synthesized and their structural and light emitting properties are studied. Copolymers show π-π* transition in UV-Vis. spectra and their λmax shift to shorter wavelength compare to that of monomers. The PL and absorption spectrum shows the symmetric vibration modes with muror images which means that copolymers are highly, aligned. The band gap energy of these copolymers are ~3.0 eV. By introducing aliphatic hydrocarbon group into polymer main chain, the stability of copolymers is increased and no significant effects of substituents are observed.

입원 정신질환자들의 수면의 질과 관련요인에 관한 연구

김명주,윤혜은,박연주,류소연 朝鮮大學校 附設 醫學硏究所 2009 The Medical Journal of Chosun University Vol.33 No.S

본 연구는 입원 정신질환자들의 생활습관과 수면의 질과의 관련요인을 알아보고자 시도되었다. 전남 나주시 국립나주병원 개방병동에 입원한 정신질환자 154명을 대상으로 2008년 7월 17일부터 7월 25일까지 인구사회학적 특성, 임상적 특성, 입원 생활습관, 입원병력특성 등을 설문지 및 병록지로 조사하였으며, Leeds Sleep Evaluation Questionnaire(LSEQ) 변형도구를 이용하여 수면의 질을 측정하였다. 입원 정신질환자들의 수면의 질 점수는 17.53±5.03점이었으며, 단순분석상에서 수면의 질은 인구사회학적 특성 등과는 관련이 없었다. 그러나 다중회귀분석 결과 과체중군에서, 입원횟수가 많을수록, 통증 정도가 심할수록 수면의 질은 나빴다. 반면, 수면제를 복용한 사람이 복용하지 않은 사람에 비해 수면의 질이 좋았다. 생활습관과 수면의 질과 유의한 차이가 없었던 것은 입원이라는 동일 환경의 한계 때문이라고 생각된다. 이상의 결과로 볼 때 입원 정신질환자들의 수면의 질을 높이기 위해서는 수면제 복용의 약물치료와 함께 체중조절을 고려하고, 통증에 대한 적극적인 대처가 이루어져야 할 것으로 생각된다. Objectives : This study was performed to identify the relations between daily habits and quality of sleep of the psychiatric inpatients. Methods: We interviewed 154 the psychiatric inpatients of open ward in Naju national hospital, Chonnam Naju, from July 17, 2008 to July 25 of the same year. Data was collected using disease records and a questionnaire about socio- demographic characteristics, clinical characteristics, habits in hospital, and characteristics in history of hospitalization. And we measured the quality of sleep using the subjective sleep questionnaire modified from Leeds Sleep Evaluation Questionnaire (LSEQ). Results: The scores of quality of sleep of inpatients were 17.53±5.03. Quality of sleep had no statistically significant relationship with various characteristics in the simple analysis. However, as a result of the multiple regression analysis, the sleep quality of the overweight group was low, and the higher frequency of hospitalization and more pain they had, the worse sleep quality was. However, the sleep quality of those who took hypnotics was higher than that of those who did not. Conclusions: This study suggests that there was no significant difference between daily habits in the hospital and the sleep quality because of limits to the same environment of being in hospital. Based on the results above, in order to enhance the sleep quality of the psychiatric inpatients, we should consider both medication which takes hypnotics and weight control and actively deal with the pain.

Immunoblotting을 이용한 Herpes Simplex Virus Type 1과 Type 2에 대한 특이 혈청 항체의 감별

박혜경,서주영 이화여자대학교 생명과학연구소 1994 생명과학연구논문집 Vol.5 No.-

There are two serotypes of herpes simplex virus, type 1 and type 2. HSV type 1 usually causes oropharyngeal infection while type 2 usually genitourinary infection. However, the clinical discrimination between two serotypes in eliciting disease entities is becoming uncertain. Furthermore, clinical discrimination is sometimes regarded of no importance due to lack of difference in treatment. However, serotyping is required for explicit diagnosis or epidemiologic survey. The conventional serological assay such as ELISA can not discriminate between HSV type 1 and type 2. Thus we tried to discriminate serum antibodies against HSV type 1 and type 2 by immunoblot analysis and compared it with the results of dot blot assay. Sera were separated from pheripheral blood of 10 patients who visited the department of dermatology or gynecology, Mok-Dong Hospital, Ewha Womans University from Jun. to Oct. 1994 for symptoms suspicious of genital herpes, 31 normal adult women, 20 pregnant women and 48 infants or children. Immunoblot analysis of HSV type 1 and type 2 revealed various patterns according to sera, not showing typical specific patterns. However, the two types could be differentiated in that type 1 frequently showed 134, 120, 106, 76, 71, 58, 50, 47kDa immunoblot bands, while type 2 showed 182, 126, 115, 109, 102, 95, 85, 81, 67kDa bands, frequently. Serum antibody positive rates against HSV type 1 and type 2 assayed by dot blot and immunoblot were contradictory in some cases. And it was false positive cases in dot blot for anti-HSV type 2 antibody which was most frequent, showing crossreaction dut to common antigenicity in whole virion antigen.