https://oak.chosun.ac.kr/handle/2020.oak/19139 Wed, 20 Aug 2025 08:43:45 GMT 2025-08-20T08:43:45Z https://oak.chosun.ac.kr/handle/2020.oak/19297 Title: 개민들레 추출물의 총 페놀 함량, 자유 라디칼 소거능 및 항균활성 Author(s): 김주성; 김경철 Abstract: This study was carried out to investigate the total phenolic content, in vitro radical scavenging ability and antimicrobial activity of Hypochoeris radicata, which were distributed widely in the Jeju Island and limiting the diversity of native plants and disturbing natural ecosystems. Total phenolics content of H. radicata methanolic extracts decreased in the following order: leaf (65.5 mg/g) > flower (60.3 mg/g) > root (44.2 mg/g) > stem (36.8 mg/g). Total flavonoid and flavonol contents were the most abundant in leaf extracts, followed by flower, stem and root. Benzoic acid showed the highest content among the phenolic acid compounds. The reducing power, DPPH radical scavenging activity and ABTS radical scavenging activity were highest in leaf extracts, while total antioxidant activity was highest in flower extracts. This is probably due to the high total phenolic contents in leaf extracts. In addition, the best antimicrobial activity was shown in flower extracts against Gram-positive bacteria (Bacillus cereus, Staphylococcus epidermidis, and Staphylococcus aureus subsp. aureus) and negative bacteria (Escherichia coli, Pseudomonas aeruginosa, and Klebsiella pneumoniae subsp. pneumoniae). This study provides basic information on the composition of phenolic acid, antioxidant and antimicrobial activities in different parts of H. radicata. Sun, 31 Dec 2017 15:00:00 GMT https://oak.chosun.ac.kr/handle/2020.oak/19297 2017-12-31T15:00:00Z https://oak.chosun.ac.kr/handle/2020.oak/19294 Title: 주행거리연장형 전기자동차를 위한 발전기 가동시점 알고리즘 개발 Author(s): 황명환; 이계성; 김동현; 차현록 Abstract: This paper describes how to determine the optimal generator operating point for Re-EV(Range-extended Electric Vehicle). Re-EV is being developed as one of the solutions to the short driving range and charge problem of electric vehicles. It can solve the problem of battery full discharge with fuel remaining in existing algorithms. The proposed algorithm through actual driving tests can be used in nonlinear power consumption patterns. And it is applicable to other range-extended electric vehicles. Simulation and experiment result validate the effectiveness of the proposed algorithm. Sun, 31 Dec 2017 15:00:00 GMT https://oak.chosun.ac.kr/handle/2020.oak/19294 2017-12-31T15:00:00Z https://oak.chosun.ac.kr/handle/2020.oak/19291 Title: 고 흡수성 수지 첨가가 증류수의 과냉각 및 열적 특성에 미치는 영향 Author(s): 이석준; 장정익; 김진혁; 이명규; 박설현 Abstract: This paper investigated the thermal properties of phase change materials (PCMs) prepared by adding a super absorbent polymer (SAP) to distilled water. The thermal properties of PCMs were investigated using differential scanning calorimeter (DSC) and T-history methods. It was found that 0.1 g SAP addition to distilled water resulted in the best PCM in terms of its thermal properties. The experimental results obtained from the DSC analysis showed that the addition of SAP to distilled water lowered the latent heat from 11.2 J/g to 17.2 J/g. However, the phase separation characteristics which are typically observed for water-based PCMs were found to be improved by adding the SAP. Similar behaviors were observed in results determined from the T-history method. Additionally, the T-history method clearly demonstrated that adding the SAP to distilled water improved the supercooling temperature, shortening the liquid retention time. Despite reductions in the latent heat of PCM with the SAP addition, it is expected that the operating cost of the cooling system can be further reduced due to its improved phase change characteristics such as phase separation and supercooling temperature when the PCM with the 0.1 g SAP added is applied. Sun, 31 Dec 2017 15:00:00 GMT https://oak.chosun.ac.kr/handle/2020.oak/19291 2017-12-31T15:00:00Z https://oak.chosun.ac.kr/handle/2020.oak/19296 Title: 청국장으로부터 단백질 분해효소 생산을 위한 Bacillus 균주 분리 및 효소 생산조건 최적화 Author(s): 김승기; 조재민; 감다혜; 김송이; 김진우 Abstract: This study was performed to investigate the optimum condition of protease production from submerged culture using Bacillus subtilis SM4 isolated from Korean bean paste. The medium adding bean sprouts powder to YP medium (YPS) resulted in 8.82 unit/mL protease activity which showed an increase 33.2% compared to YP medium. Among several carbon sources, fructose (2.25%, w/v) yielded 95.4 unit/mL of maximum protease activity. Comparison of different nitrogen sources indicated that 2.25% (w/v) casein showed the highest protease activity of 385.4 unit/mL. In the temperature optimization experiment, it was confirmed that the production of protease using B. subtilis SM4 occurred in the fermentation temperature of 25℃. The optimum temperature for the production of protease was 25℃ indicating B. subtilis SM4 protease would be suitable for the hydrolysis of protein and the production of functional peptide from agro-industrial byproducts at low temperature. The maximum enzyme production of 568.5 unit/mL was obtained from the optimization of medium compositions and incubation conditions, which showed that B. subtilis SM4 protease could be replaced commercial enzymes for the hydrolysis of proteins from agro-industrial byproducts. Sun, 31 Dec 2017 15:00:00 GMT https://oak.chosun.ac.kr/handle/2020.oak/19296 2017-12-31T15:00:00Z