• 멤브레인
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• 제25권3호
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• pp.287-294
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• 2015

태양전지는 태양복사에너지를 반도체의 광전효과를 통해 전기에너지로 변환시키는 친환경 에너지변환장치를 의미한다. 수분을 포함하는 다양한 화학물질들에 대한 높은 차단성을 갖는 다층형 필름인 백시트는 태양전지의 중요한 요소이다. 대표적인 백시트는 polyvinyl fluoride (PVF)와 poly(ethylene terephthalate) (PET)의 다층필름으로 구성된다. PVF는 높은 내후성을 가지는 반면, 가격이 상대적으로 비싼 단점을 보인다. 따라서, 백시트의 제조가격을 낮출 수 있으면서, 동시에 실제 태양전지모듈에 적용할만한 수명특성을 만족시킬 수 있는 대체소재의 개발이 필수적이다. 본 연구에서는 일정수준의 결정성을 갖는 PET 필름을 PVF 필름 대신 사용하였다. 그러나, PET 소재는 다양한 pH 조건에서 trans-esterification 및 가수분해에 의해 분해될 수 있기 때문에, 태양전지의 구동조건에서 PET의 분해거동을 이해할 필요가 있다. 단시간 내 화학적 분해거동을 평가하기 위해서, 가속화된 PET 분해실험 프로토콜이 개발되었다. 마지막으로, 제안 개념의 효용성은 태양전지모듈의 장기운전성능 평가를 통해 확인하였다.

• Food Science and Biotechnology
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• 제15권1호
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• pp.5-12
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• 2006

Degradation performance of environmentally friendly plastics that can be disintegrated by combination of sunlight, microbes in soil, and heat produced in landfills was evaluated for use in industries. Two multi-degradable master batches (MCC-101 and MCC-102 were manufactured, separately mixed with polyethylene using film molding machine to produce 0.025 mm thick films, and exposed to sunlight, microbes, and heat. Low- and high-density polyethylene (LDPE and HDPE) films containing MCC-101 and MCC-102 became unfunctional by increasing severe cleavage at the surface and showed high reduction in elongation after 40 days of exposure to ultraviolet light. LDPE and HDPE films showed significant physical degradation after 100 and 120 days, respectively, of incubation at $68{\pm}2^{\circ}C$. SEM images of films cultured in mixed mold spore suspension at $30^{\circ}C$ and 85% humidity for 30 days revealed accelerated biodegradation on film surfaces by the action of microbes. LDPE films containing MCC-l01 showed absorption of carbonyls, photo-sensitive sites, at $1710\;cm${-1}$ when exposed to light for 40 days, whereas those not exposed to ultraviolet light showed no absorption at the same frequency. MCC-101-based LDPE films showed much lower $M_w$ distribution after exposure to UV than its counterpart, due to agents accelerating photo-degradation contained in MCC-101.

• Transactions on Electrical and Electronic Materials
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• 제10권6호
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• pp.222-226
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• 2009

The objective of this study is to share multimedia contents included in existing digital devices and to solve the problems of an increase in installation fees and non-environmentally friendly interiors. This study designed a new digital signal transmitter and receiver using power line transmission and HDMI in order to solve the problems in the existing systems. The transmitter and receiver designed in this study used an AD9867BCPZ PLC chip in which the transmission came from digital signals originating in a PC, and the system architecture was configured so that the outputs signals were connected to a TV from the receiver. The experiment was implemented by adding a Video Test Generator, a USBPre external sound card, and Smaart Live 6 for analyzing the characteristics of the configured system. In the video test results, it was verified that communication was actively implemented, and the image quality showed a constant level from the measurement of the captured video. In the case of the sound, it was verified that more than 90% of the sound signals were normally transmitted and received from the examination of their phases and magnitudes. Thus, the performance of the system designed in this study was verified, which leads to the resolution of some of the problems found in current digital devices.

• 한국항해항만학회지
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• 제35권6호
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• pp.515-522
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• 2011

이 연구는 플로팅 호텔의 건축계획에 대한 것으로, 관련 문헌과 인터넷 검색을 통하여, 플로팅 호텔의 개념을 살펴보고, 사례를 분석하여, 앞으로 플로팅 호텔 계획을 위한 참고자료를 제시하고자 한다. 플로팅 호텔은 수상 부유시스템을 갖는 건축물로서, 인간의 거주/휴양/업무/오락 등의 목적으로 사용되며, 자유로운 항해는 불가능하다. 연구대상 건축물들은 콰이강 뗏목 리조트가 1976년, Four Seasons Hotel은 1988년, Salt & Sill은 2008년 등의 순서로 건립되었다. 플로팅 호텔의 규모는 층과 실의 개수 등의 측면에서 다양하고, 부대시설로는 다양한 기본시설, 문화시설, 운동시설, 해양관련 시설 등이 있다. 플로팅 호텔의 건축적 특징으로는, 설비 자립화, 친환경 건축계획, 재생에너지의 활용, 복합재료 도입, 호텔을 회전을 통한 모든 객실에 동등한 경관 제공 등을 들 수 있다.

• Advances in concrete construction
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• 제8권3호
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• pp.225-237
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• 2019

Although applying self-consolidating concrete (SCC) in many modern structures is an inevitable fact, the high consumption of cement in its mixing designs has led to increased production costs and adverse environmental effects. In order to find economically viable sources with environmentally friendly features, natural pozzolan pumice and blast furnace slag in 10-50% of replacement binary designs have been investigated for experiments on the properties of fresh concrete, mechanical properties, and durability. As a natural pozzolan, pumice does not require advanced equipment to prepare for consumption and only needs to be powdered. Pumice has been the main focus of this research because of simple preparation. Also to validate the results, in addition to the control specimens of each design, fly ash as a known powder has been evaluated. Moreover, ternary mixes of pumice and silica fume were investigated to enhance the obtained results of binary mixes. It was concluded that pumice and slag powders indicated favorable performance in the high percentage of replacement.

• Journal of Microbiology and Biotechnology
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• 제31권9호
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• pp.1311-1322
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• 2021

Microbially induced calcium carbonate precipitation (MICP) has recently become an intelligent and environmentally friendly method for repairing cracks in concrete. To improve on this ability of microbial materials concrete repair, we applied random mutagenesis and optimization of mineralization conditions to improve the quantity and crystal form of microbially precipitated calcium carbonate. Sporosarcina pasteurii ATCC 11859 was used as the starting strain to obtain the mutant with high urease activity by atmospheric and room temperature plasma (ARTP) mutagenesis. Next, we investigated the optimal biomineralization conditions and precipitation crystal form using Plackett-Burman experimental design and response surface methodology (RSM). Biomineralization with 0.73 mol/l calcium chloride, 45 g/l urea, reaction temperature of 45℃, and reaction time of 22 h, significantly increased the amount of precipitated calcium carbonate, which was deposited in the form of calcite crystals. Finally, the repair of concrete using the optimized biomineralization process was evaluated. A comparison of water absorption and adhesion of concrete specimens before and after repairs showed that concrete cracks and surface defects could be efficiently repaired. This study provides a new method to engineer biocementing material for concrete repair.

• 한국농공학회논문집
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• 제63권3호
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• pp.97-105
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• 2021

Most of the rural development projects for the welfare of residents are mainly new construction and remodeling projects for community buildings such as village halls and senior citizens. However, in the case of the construction industry, it has been studied that 23% of the total carbon dioxide emissions generated in Korea are generated in the building-related sector. (GGIC, 2015) In order to reduce the emission of environmental pollutants resulting from construction of rural community buildings, there is a need to establish a system for rural buildings by predicting the environmental impact. As a result of this study, the emissions of air pollutants from buildings in rural communities were analyzed by dividing into seven stages: material production, construction, operation, maintenance, demolition, recycling, and transportation activities related to disposal. As a result, 12 kg of carbon dioxide (CO), 0.06 kg of carbon monoxide (CO), 0.02 kg of methane (CH), 0.04 kg of nitrogen oxides (NO), 0.02 kg of sulfurous acid gas (SO), and non-methane volatile organics per 1m of buildings in rural communities It was analyzed that 0.02 kg of compound (NMVOC) and 0.00011 kg of nitrous oxide (NO) were released. This study proved that environmentally friendly design is possible with a quantitative methodology for the comparison of operating energy and air pollutant emissions through the design specification change based on the statement of the rural community building. It is considered that it can function as basic data for further research by collecting major structural changes and materials of rural community buildings.

• 한국건설순환자원학회논문집
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• 제9권4호
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• pp.460-468
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• 2021

이산화탄소 및 온실가스의 배출, 과도한 에너지 소비 및 천연자원의 고갈을 막기 위해 콘크리트의 대체재를 찾는 것은 건설업의 해결과제이다. 이러한 문제를 해결하기 위해, 콘크리트보다 환경친화적인 지오폴리머가 주목을 받고 있으며, 실제 시공을 목적으로 강도 및 내구성에 대한 연구가 진행되고 있다. 일반적으로, 지오폴리머의 강도 및 내구성은 알칼리 용액의 종류 및 농도, 전구물질, 양생 온도 및 시간 등 여러 요인에 따라 달라지며, 이는 지오폴리머의 강도와 내구성에 영향을 미치는 화학조성 및 미세구조에 큰 영향을 미친다. 기존의 연구에서 최적의 알칼리 용액의 종류 및 농도, 전구물질, 양생 온도 및 시간을 통하여 지오폴리머의 압축강도 및 내구성이 향상되는 것을 확인하였으며, 본 연구에서는 과거의 연구 결과를 검토하고 이러한 요인이 지오폴리머의 압축강도 및 내구성에 미치는 영향을 체계적으로 종합하였다.

• 인간식물환경학회지
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• 제21권6호
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• pp.501-514
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• 2018

This study aimed to develop a program that can be linked to gardening education activities in elementary students' curriculums and creative experience learning courses, and to apply the developed program to 6th graders in an elementary school located in Seoul. Research was conducted in a large category called biophilia, which named the instinct of human nature and nature throughout the research. The curriculum revised in 2015 was selected for the purpose of the garden education program based on the objectives and contents of the unit, and for the purpose of the class. In the process of developing and implementing the program, experience properties and elements were divided into direct and indirect experience of nature, including shapes and forms found in nature, air, water, plants, weather, animals, and natural materials. The results showed that the biophilic horticultural education program was effective in promoting students' multi senses. In the case of the experimental group, all the multi-sensory areas showed statistically significant differences, especially in the area of environmental literacy, environmental effect and emotional balance including plant cultivation knowledge. There was a relatively smaller difference in the dietary effect area than other areas because of no directional dietary program was included in the developed program. As a result, first, it is expected that the data can be utilized on site as a program or place of activity for students in upper grades. Second, it will be necessary to develop a more diverse program using other biophilic elements that were not covered in this study in order to maximize the effects of biophilic education.

• 패션비즈니스
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• 제23권4호
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• pp.127-139
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• 2019

Up-cycling has evolved from its original form of the simple recycling of waste, into an industry of its own that has been gaining momentum. In many developed industries, up-cycling is increasingly seen as an 'environmentally-friendly way of production and ethical way of consumption'. However, an examination of the designs of branded up-cycled products suggests that there is a need for product development fueled by further research on materials. The purpose of this study is to introduce various production methods that can overcome the shortcomings of using waste material and Korean motifs for use in product development, which ultimately contribute to enhancing the potential variety and character of up-cycled products. In order to do so, the up-cycling industry was examined to define key concepts, domestic and overseas markets were surveyed, and case analyses were conducted on domestic and foreign up-cycling brands. In addition, after tracking how leather is discarded and accumulated as waste and then collecting the discarded leather, the properties of the material were analyzed. A study of Korean motifs was followed by the concept summary, and upcycling design expressions that exemplify Korean images were identified. The following two novel methods were used to create six up-cycled bags using collected discarded leather. First, lucky bags and moon pots were selected from various Korean motifs in order to use motifs with identifiable features. Secondly, different variations of cutting and attachment methods were used, including iron mold production methods and presses.