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        검색결과 3

        1.
        2022.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Heavy bitumen scattered in the underground sedimentary layer is a kind of unconventional energy source, and by extracting it, a production well is excavated in the sedimentary layer and high-temperature and high-pressure steam is injected to reduce the viscosity of bitumen and recover it to the ground steam assisted method is applied. As a recovery method that uses the steam effect of the dilution effect of solvent injection, it is a recovery method that can increase thermal efficiency. In this study, the process system of the central processing facility(CPF) of the hybrid steam-solvent recovery method that injects solvent into the existing steam assisted method was analyzed, and the core facilities for each process were identified, and hybrid steam-solvent recovery compared to the existing steam assisted method. In the case of the method, it was evaluated that the amount of steam supply and all utility costs decreased according to the solvent injection.
        4,000원
        2.
        2012.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was conducted to assess the levels of microbiological hazards of preprocessed Namuls, which were served at the school foodservice. 19 preprocessed ground or root vegetables were collected from 21 schools in May to June of 2011. Heavy contamination of aerobic plate counts (from 3.39 to 8.42 logCFU/g) and total coliform groups (from 3.16 to 7.84 logCFU/g), enterobacteriaceaes (from 2.53 to 7.55 logCFU/g) were detected in preprocessed Namuls. In addition, the detection rates of Escherichia coli, Staphylococcus aureus and Bacillus cereus (emetic form) were 4.3%, 11.7% and 2.1%, respectively. In addition, sanitary indicative bacterium at preprocessing steps of root vegetables (lotus root, burdock root, bellflower root) and blanched Namuls (bracken, sweet potato vine, chinamul) were analyzed. Aerobic plate counts, coliform groups, and enterobacteriaceaes were not effectively removed during preprocessing including washing and soaking steps. In the case of blanched Namuls (bracken, sweet potato vine, chinamul), contamination levels increased more after drying process and no significant reduction effect on the levels of microbial contamination was observed during preprocessing steps. Thus, effect of preprocessing steps on the microbiological hazards in Namuls must be reevaluated to improve the microbiological quality of preprocessed Namuls at the school foodservice and retail markets.
        4,000원
        3.
        2009.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, we examined the composition of catechins, theaflavins and alkaloids in leaves during processing to fermented black tea, which is produced by withering, roll breaking, and fermentation of Korean Yabukida tea plant. In addition, we determined the optimal conditions for the production of fermented black tea. The average moisture content in fresh leaves was 70.85%, which dropped to 3.07% in fermented black tea at the last stage of production. When the leaves were analyzed by HPLC, seven types of catechins, four types of theaflavins and three types of alkaloids were identified. The levels of catechins, theaflavins, and alkaloids were then evaluated after being processed into fermented tea. From these experiments, we found that the level of theaflavins, which determines the property of the tea, increased during fermentation. This effect resulted from the change in EGCG, ECG, EGC, EC during the process of fermentation. We also found that the maximal amount of theaflavins was created after 1-2 hours of fermentation. Thus, our results imply that the best condition for producing fermented black tea would be to ferment for 1-2 hours.
        4,000원