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        검색결과 227

        61.
        2020.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The difficulty of securing freshwater sources is increasing with global climate change. On the other hand, seawater is less affected by climate change and regarded as a stable water source. For utilizing seawater as freshwater, seawater desalination technologies should be employed to reduce the concentration of salts. However, current desalination technologies might accelerate climate change and create problems for the ecosystem. The desalination technologies consume higher energy than conventional water treatment technologies, increase carbon footprint with high electricity use, and discharge high salinity of concentrate to the ocean. Thus, it is critical to developing green desalination technologies for sustainable desalination in the era of climate change. The energy consumption of desalination can be lowered by minimizing pump irreversibility, reducing feed salinity, and harvesting osmotic energy. Also, the carbon footprint can be reduced by employing renewable energy sources to the desalination system. Furthermore, the volume of concentrate discharge can be minimized by recovering valuable minerals from high-salinity concentrate. The future green seawater desalination can be achieved by the advancement of desalination technologies, the employment of renewable energy, and the utilization of concentrate.
        4,000원
        66.
        2020.11 구독 인증기관 무료, 개인회원 유료
        The current study uses risk theory to explore factors mitigating consumers’ intention to use SSTs. The findings of an empricial study reveal that the perceived time, security and addiction risk indirectly reduce consumers’ intention to use SSTs through the per-ceived psychological risk. Most importantly, this study’s findings show that an increas-ing autonomy of SSTs strengthens the effects of perceived addiction risk.
        4,000원
        68.
        2020.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The removal of organic carbon and nutrients (i.e. N and P) from wastewater is essential for the protection of the water environment. Especially, nitrogen compounds cause eutrophication in the water environment, resulting in bad water quality. Conventional nitrogen removal systems require high aeration costs and additional organic carbon. Microbial electrochemical system (MES) is a sustainable environmental system that treats wastewater and produces energy or valuable chemicals by using microbial electrochemical reaction. Innovative and cost-effective nitrogen removal is feasible by using MESs and increasing attention has been given to the MES development. In this review, recent trends of MESs for nitrogen removal and their mechanism were conclusively reviewed and future research outlooks were also introduced.
        4,300원
        69.
        2020.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Metal additive manufacturing (AM) technologies are classified into two groups according to the consolidation mechanisms and densification degrees of the as-built parts. Densified parts are obtained via a single-step process such as powder bed fusion, directed energy deposition, and sheet lamination AM technologies. Conversely, green bodies are consolidated with the aid of binder phases in multi-step processes such as binder jetting and material extrusion AM. Green-body part shapes are sustained by binder phases, which are removed for the debinding process. Chemical and/or thermal debinding processes are usually devised to enhance debinding kinetics. The pathways to final densification of the green parts are sintering and/or molten metal infiltration. With respect to innovation types, the multistep metal AM process allows conventional powder metallurgy manufacturing to be innovated continuously. Eliminating cost/time-consuming molds, enlarged 3D design freedom, and wide material selectivity create opportunities for the industrial adoption of multi-step AM technologies. In addition, knowledge of powders and powder metallurgy fuel advances of multi-step AM technologies. In the present study, multi-step AM technologies are briefly introduced from the viewpoint of the entire manufacturing lifecycle.
        4,300원
        70.
        2020.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        전 세계 화석 연료 사용이 지속적으로 증가함에 따라 공기 중 이산화탄소(CO2) 농도가 수 세기에 걸쳐 증가하고 있다. 대기로의 CO2 배출을 줄이기 위한 방법으로, 주요 배출원인 발전소와 공장에 적용할 수 있는 이산화탄소 포집 및 저장 (carbon capture and sequestration, CCS) 기술이 개발되고 있다. 기후 변화 완화 정책에 따라 negative emission 기술로 언급 되는 공기 중 CO2 직접 포집 기술(direct air capture, DAC)은 CO2 농도가 0.04%로 매우 낮기 때문에 기존의 CCS 기술에 적 용된 기술과 달리 흡착제를 이용한 저농도 CO2 포집 연구에 집중되어 있다. DAC 분야는 주로 CO2의 흡착을 이용한 습식 흡 착제, 건식 흡착제, 아민 기능화된 소재, 이온교환 수지 등이 연구되었다. 흡착제 기반 기술은 흡착제 재생에 따른 고온 열처 리 공정이 필요하기 때문에 추가적인 에너지 소모가 없는 분리막 기반의 공기 중 CO2 포집 기술의 잠재력이 크다. 분리막은 특히 실내 공기 CO2 저감 환기 시스템 및 실내용 스마트팜(smart farm) 시스템의 연속적인 CO2 공급에 사용될 수 있을 것으 로 기대된다. CO2 처리 기술은 기후 변화를 완화하기 위한 수단으로 개발이 지속되어야 하며 효율적인 공정 설계와 소재 성 능 향상을 통해 공기 중 CO2 포집의 효율을 높일 수 있을 것이다.
        4,000원
        71.
        2020.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The research model of panel data analysis in this study was used as the dependent variables and the business characteristics of the welding industry were reflected in the research model for systematic analysis of the effect of welding technology on the welding industry. As a result of the existing research, the domestic welding technology is seriously encroaching on the domestic welding industry between the United States, Japan and China. There is no quantitative statistical analysis on this aspect. In this study, the panel data analysis is used to indicate differences in explanatory power by numerical values of POLS model, fixed effect and random effect. And the prior studies on the current status of welding industry related to arc welding, special welding, multiple welding, welding and bonding technology are applied by the panel data analysis. Therefore, the problems of existing research are diagnosed while presenting the future research directions.
        4,000원
        72.
        2019.12 구독 인증기관 무료, 개인회원 유료
        Probiotics have been shown to benefit human health through their role in improving the health of our body, especially gastrointestinal tracts. Probiotic bacteria are commonly incorporated into a variety of functional foods or drug formulations. Despite the extensive commercial exploitation of probiotic bacteria, there are still major knowledge gaps regarding the precise molecular composition and labeling of products. Several studies have reported issues concerning the accuracy of labeling of commercial probiotic products, including inaccurate taxonomy and cell counting. The study of microbiology and genomics has been accelerated by the invention of new technologies such as next generation sequencing (NGS) and flow cytometry (FACS). Recent many studies showed that NGS and FACS technology can be also applied for quality control of commercial probiotics. Here, we review advantages and limitations of current technologies for quality control of commercial probiotics. Principles and applications of new technologies are also introduced as alternative tools for the same purposes.
        4,000원
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