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Development of additives for DME as a renewable energy
장은정(Jang, Eunjung),박천규(Park, Cheonkyu),임의순(Yim, Eui-Soon),정충섭(Jung, Choong-Sub),이봉희(Lee, Bonghee) 한국신재생에너지학회 2011 한국신재생에너지학회 학술대회논문집 Vol.2011 No.05
DME is generally expected to be used as a promising clean alternative fuel to diesel fuel. DME is not natural product but a synthetic product that is produced either through the dehydration of methanol or a direct synthetic from syngas. As DME has no carbon-carbon bond in its molecular structure and is an oxygenate fuel, it's combustion essentially generates no soot. DME has such cetane number of 55~60 that it can be used as a diesel engine fuel. However, DME has low lubricity but a proven method to solve the poor lubricity is by adding lubricity improver. Therefore, the aim of this study is to develop lubricity improver of DME as a transport fuel in Korea. In this study, we investigated a possibility of fatty acid ester compounds as a candidate to improve DME lubricity as compared with current lubricity improver of diesel. We also evaluated quality characteristics, storage stability of DME with lubricity additives.
글로벌 충격에 대응하는 과학기술 다자협력 전략: 유엔시스템을 중심으로
신은정(Eunjung Shin),박환일(Hwanil Park),박병원(Byeongwon Park),성경모(Kyung-Mo Sung),박동운(Dongun Park),장용석(Yongsuk Jang),장진규(Jin Gyu Jang),권소현(So Hyun Kwon),김지은(Ji Eun Kim),최동주(Dong Ju Choi),김진하(Jinha Kim),오채운(Ch 과학기술정책연구원 2021 정책연구 Vol.- No.-
This study was designed to develop multilateral STI (Science, Technology and Innovation) cooperation strategies in response to the global shocks that we are currently experiencing and that may arise in the future. To this end, this paper first investigated the development of multilateral STI cooperation centered on the United Nations system (UN system), and then surveyed UN system’s response to global shocks such as COVID-19. The key findings of this study are summarized as follows. First, STI cooperation in the UN system has been continuously promoted as a means of achieving international security and development since the establishment of the UN. Security-related STI cooperation has been mainly discussed at the Security Council and the UN General Assembly, and the Related Agencies, such as IAEA, CTBTO, and OPCW, have been also playing a key role. Moreover, STI cooperation for development has been heavily discussed at the Economic and Social Council including CSTD and ESCAP, and Specialized Agencies such as ITU, UPU, IMO, WMO, UNESCO, WIPO, and WHO have also played a significant role for STI cooperation. Furthermore, policy agendas related to innovation, sustainable development, and digital technology have been increasingly emphasized for STI cooperation within the UN system these days. Recently developed organizations, such as the Technology Facilitation Mechanism (TFM) for Sustainable Development, and UNFCCC, are dealing with these emerging needs for STI cooperation. Second, the United Nations system has evolved to respond to global shocks. It has broadened the scope of cooperation in response not only to global security risk but also to economic and financial crises. It has further developed multi-lateral cooperation schemes to cope with various environmental emergencies as well as health emergencies. In particular, the UN system has devised and delivered immediate and comprehensive emergency responses in the amid of the recent COVID-19 pandemic. From the beginning of the outbreak, it defined COVID-19 as a complex crises that combine not only health issues but also socio-economic and humanitarian threats and strived to take comprehensive measures. In this process, the following needs for STI cooperation were identified and met: 1) joint research and R&D collaboration for scientific solutions to COVID-19 (treatment, diagnosis, vaccine, and prevention measures), 2) research data and resource sharing for accelerating R&D, 3) digital technology-based assistance to overcome crises, and 4) global consultation and communication based on reliable scientific information and knowledge. The occurrence of global shocks has led to new development of science-policy interfaces in the UN system. In order to fully utilize the newly created STI cooperation opportunities in emergencies, this study proposes to (1) support more STI experts to get engaged in UN cooperation process, (2) increase Korea’s contribution to global joint research and technology cooperation that directly tackle global crises, (3) actively participate in the UN’s system coordination activities and digital cooperation initiatives, and (4) to propose and lead a future STI cooperation agenda, such as crisis response based on future foresight. Furthermore, it is recommended to continuously strengthen Korea’s existing activities for STI cooperation in the UN system. Lastly, although not fully addressed in this study, STI cooperation beyond the UN system is so important that requires further research.
사례기반학습을 통한 유아교사의 놀이 개입유형 변화경험 탐색
장은정(Jang EunJung),유영의(Yoo YungEui) 학습자중심교과교육학회 2020 학습자중심교과교육연구 Vol.20 No.5
본 연구는 사례기반학습을 통한 유아교사의 놀이 개입유형의 변화를 알아보는 것이다. 이를 위하여 B어린이집 만 4세반 담임교사 2명을 연구 참여자로 선정하였으며, 2018년 11월부터 2019년 11월까지 사례기반학습 설계, 예비연구, 연구 참여교사 선정 및 현장 방문, 사례기반학습 실행의 4단계로 연구를 진행하였다. 연구 참여교사의 놀이 개입유형의 변화를 알아보고자 교사들이 담당하고 있는 하늘 1, 2반의 자유놀이시간을 연구자가 비참여 관찰하였고, 참여관찰, 면담, 토의노트 및 저널, 사례기반학습 토의과정을 토대로 자료를 수집하여 분석하였다. 그 결과 사례기반학습을 통한 유아교사의 놀이 개입유형 변화는 놀이를 민감하게 관찰하고 반응하는 방관자 개입유형으로 변화하기, 놀이 환경을 풍부하게 제공해주는 무대관리자 개입유형으로 변화하기, 유아의 의견을 수용하며 놀이를 공동구성하는 공동놀이자 개입유형으로 변화하기, 유아주도의 놀이가 지속될 수 있도록 놀이를 안내하는 놀이지도자 개입유형으로 변화하기, 지시보다는 효율적으로 놀이를 제안하는 감독 및 방향전환자 개입유형으로 변화하기가 나타났다. The aim of this study was to investigate early childhood teachers’ changes in play intervention type through case-based learning. To this end, two homeroom teachers of 4-year-old class at B child care center were selected as the research participants. From November 2018 to November 2019, the research was conducted in four stages: case-based learning design, preliminary research, selection of participating teachers and field visits, and implementation of case-based learning. In order to investigate the participating teachers’ changes in play involvement type, the researcher conducted a non-participatory observation. Data were collected from and analyzed based on observation notes, interviews, discussion notes and journals, and case-based learning discussion process. As a result, it was found that early childhood teachers show the following changes in play intervention type: changes to a bystander who observes and responses sensitively to play, a stage manager who provides rich play environment, a co-player who accepts the opinions of young children jointly and organizes play, a play leader who guides play so that child-initiated play is sustained, and a director and redirector who efficiently suggests play rather than giving instructions
Color Change of Esthetic Restorative Materials for Different Staining and Whitening Dentifrices
( Eunjung Choi ),( Hyeonsoo Jang ),( Yelim Seo ),( Youngju Kim ),( Gayoung Lee ),( Youlim Kim ),( Soo-jeong Hwang ) 한국치위생과학회 2021 치위생과학회지 Vol.21 No.3
Background: As the importance of the esthetic function of teeth increases, the use of esthetic restoration materials and whitening treatment are increasing. The purpose of this study was to investigate the color change of esthetic restoration materials upon using staining and whitening toothpaste. Methods: Light curing (LC) packable composite resin, LC flowable resin, LC glass ionomer (GI), and self-curing GI specimens were colored in coffee or curry for three hours a day for seven days. After that, regular toothpaste, whitening toothpaste containing hydrogen peroxide, and whitening toothpaste containing activated charcoal were applied for three minutes three times a day for two weeks. Luminosity (L), chromaticity a (a), and chromaticity b (b) were measured using a spectrophotometer once a week. Results: In the coffee-colored group, the change in L<sup>2</sup>*a<sup>2</sup>*b<sup>2</sup> (E<sup>2</sup>) with time was significant (p=0.004), there was no difference for different toothpaste types (p=0.646), and there was significant difference (p<0.001) for different esthetic restorative materials. The change of E<sup>2</sup> in the curry-colored group was significant only for different esthetic restorative materials (p<0.001). In the coffee-colored group, the L, a, and b values of the light-curing GI showed greater change than other materials after staining and one week after whitening, turning dark, red, and yellow. In the curry-colored group, L did not differ for different materials and times, and a and b showed the greatest difference in light-curing GI after staining and one and two weeks after whitening. Conclusion: The use of whitening toothpaste for two weeks was not different from the use of general toothpaste in the removal of staining or whitening. Since light-curing GI is the most vulnerable to coloration, it is recommended that coloring by food chromogen should be explained in advance, before using light-curing GI for teeth restoration.
Restoration of Traditional Korean Nuruk and Analysis of the Brewing Characteristics
( Jang-eun Lee ),( Ae Ran Lee ),( Hyeryun Kim ),( Eunjung Lee ),( Tae Wan Kim ),( Woo Chang Shin ),( Jae Ho Kim ) 한국미생물 · 생명공학회 2017 Journal of microbiology and biotechnology Vol.27 No.5
In this study, a total of 58 different kinds of nuruk (a traditional Korean fermentation starter) were prepared, including 46 kinds of restored nuruk from ancient documents. Each nuruk was evaluated by analysis of its saccharification power, and the enzyme activities of glucoamylase, α-amylase, β-amylase, protease, and β-glucanase. The range of saccharification power (sp) of the restored nuruk ranged between 85 and 565 sp. The diastatic enzymes, α-amylase, β-amylase, and glucoamylase, were significantly correlated to the saccharification power value; conversely, β-glucanase and protease did not have a correlative relationship with saccarification power. In addition, their brewing properties on chemical and organoleptic aspects of traditional alcoholic beverage production were compared. Each raw and supplementary material contained in nuruk showed its own unique characteristics on Korean alcoholic beverage brewing. For the first time, in this study, the traditional Korean nuruk types mentioned in ancient documents were restored using modernized production methods, and also characterized based on their brewing properties. Our results could be utilized as a basis for further study of traditional alcoholic beverages and their valuable microorganisms.