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        검색결과 10

        1.
        2021.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Ni–Cr–Al metal-foam-supported catalysts for steam methane reforming (SMR) are manufactured by applying a catalytic Ni/Al2O3 sol–gel coating to powder alloyed metallic foam. The structure, microstructure, mechanical stability, and hydrogen yield efficiency of the obtained catalysts are evaluated. The structural and microstructural characteristics show that the catalyst is well coated on the open-pore Ni–Cr–Al foam without cracks or spallation. The measured compressive yield strengths are 2–3 MPa at room temperature and 1.5–2.2 MPa at 750oC regardless of sample size. The specimens exhibit a weight loss of up to 9–10% at elevated temperature owing to the spallation of the Ni/Al2O3 catalyst. However, the metal-foam-supported catalyst appears to have higher mechanical stability than ceramic pellet catalysts. In SMR simulations tests, a methane conversion ratio of up to 96% is obtained with a high hydrogen yield efficiency of 82%.
        4,000원
        2.
        2020.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Probiotic-derived bacteriocins have attracted considerable attention as an alternative to synthetic preservatives in the food industry, as synthetics are harmful to health. Lactobacillus gasseri G2 isolated from infant feces has been demonstrated to possess probiotic properties such as bile salt and acid tolerance, antibiotic resistance, and broad antimicrobial activity. Bacteriocin was partially purified by acetone precipitation and characterized for several properties. It was found to be highly thermostable and resistant to heating at 120oC for 15 min. Bacteriocin activity remained unaffected with changes in the pH range from 2.0 to 10.0 and by solvents such as acetone, methanol, ethanol, and butanol. The antimicrobial activity was not affected by α-amylase, lysozyme, and lipase, but was reduced after treatment with protease, trypsin, and proteinase K, suggesting that it has a proteinaceous nature. Bacteriocin inhibited a broad range of target bacteria belonging to both Gram-positive and Gram-negative groups: Bacillus cereus, Listeria monocytogenes, Staphylococcus aureus, Clostridium perfringens, Escherichia coli O157:H7, Enterobacter sakasakii, Salmonella Enteritidis, Shigella flexneri, Shigella boydii, Vibrio parahaemolyticus, and Vibrio vulnificus. Bacteriocin appeared as a smear of the protein band with a molecular weight between 2-5 kDa, which showed a clear zone of inhibition after bioassay. The high thermostability and acid/alkali stability of bacteriocin reflect its potential commercial significance.
        4,000원
        3.
        2019.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The diesel engine generate many pollutants such as PM(Particulate matter) and NOx(Nitrogen oxide). So the SCR(Selective catalytic reduction) must be required to meet the emission standard. The SCR catalyst market is growing rapidly, and the automobile markets using alternative energy sources are growing rapidly. This study deals with optimization of the calcination process the manufacturing process of SCR catalyst to be competitive. The calcination process is a bottleneck and it is required to optimize productivity and accept to be safety, But we cannot trade off anything in terms of safety. We applied DOE(Design of experiments) among many research methods performed in various fields. In order to achieve quality and productivity optimization. The dependent variables in the DOE were selected as NO Conversion(%). The independent variables were selected as the calcination temperature, soaking time and fan speed RPM. the CCD(Central composite designs) constructs response surface using the data onto experience and finds optimum levels within the fitted response surfaces. Our tests are our stability guarantee and efficient together with operation.
        4,000원
        4.
        2017.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Fish skin peptide-loaded liposomes were prepared in 100 mL and 1 L solution as lab scales, and 10 L solution as a prototype scale. The particle size and zeta potential were measured to determine the optimal conditions for the production of fish skin peptide-loaded liposome. The liposome was manufactured by the following conditions: (1) primary homogenization at 4,000 rpm, 8,000 rpm, and 12,000 rpm for 3 minutes; (2) secondary homogenization at 40 watt (W), 60 W, and 80 W for 3 minutes. From this experimental design, the optimal conditions of homogenization were selected as 4,000 rpm and 60 W. For the next step, fish peptides were prepared as the concentrations of 3, 6, and 12% at the optimum manufacturing conditions of liposome and stored at 4ºC. Particle size, polydispersion index (pdI), and zeta potential of peptide-loaded liposome were measured for its stability. Particle size increased significantly as manufacture scale and peptide concentration increased, and decreased over storage time. The zeta potential results increased as storage time increased at 10 L scale. In addition, 12% peptide showed the formation of a sediment layer after 3 weeks, and 6% peptide was considered to be the most suitable for industrial application.
        4,000원
        5.
        2016.11 구독 인증기관·개인회원 무료
        느타리버섯(Pleurotus ostreatus)은 우리나라에서 재배되고 있는 버섯류 중 가장 큰 비중을 차지하고 있는 버섯 으로 재배방식의 발달과 더불어 품질이 균일하고 수량성이 높은 혼합배지를 개발하고자하는 많은 연구가 수 행되어 왔다. 느타리버섯의 인공재배에 이용되는 배지의 종류 또한 재배양식에 따라 달라지는데 느타리버섯 재배 초기는 원목재배에서 많은 수량을 내기위해 볏짚과 방울솜을 이용한 균상재배가 이루어 졌다. 그런데 느타리버섯생산이 생력화 되고 자동화 되면서 원재료가 바꿔지게 되었는데 사용되는 원재료는 톱밥을 주재 료하고 여기에 부재료로 다양한 영양원이 첨가된 배지로 버섯을 생산하였다. 부 재료로 미강, 밀기울, 비트펄 프, 면실박, 면실피, 건비지 등이 사용되고 있다. 그런데 사회의 구조변화로 도시화와 산업화로 인해 식품소 비패턴의 변화는 농축산물에 대한 안전성 문제가 대두 되었다. 이에 따라 정부에서는 농산물 안전 관리 요구 로 우수농산물(GAP)을 도입 다양한 농산물 안전관리제도를 운용하게 됨에 따라 버섯도 이에 대응한 자실체 를 생산하기 위해 적정기준이 마련되어져야 한다. 따라서 본 연구는 느타리버섯 병재배에 사용되는 주재료 및 부재료 그리고 생산된 자실체에서 유해성 등을 조사하여 안전한 버섯을 생산하는 기준을 설정하고자 하 였다.
        6.
        2015.11 구독 인증기관·개인회원 무료
        산소 분리를 위한 세라믹 중공사막을 상전이 방적기술을 통해 제조하였다. 초기 BSCF 선구물질은 고상반응법을 이용하여 합성한 상용 분말이며, 고분자 용액에 분산시킨 후 이중관형 노즐을 통해 사출하였다. 사출된 분리막은 상전이 과정을 거친 후 건조시켰으며 중공사막의 한쪽 끝을 밀봉하였다. 한쪽 끝이 막힌 중공사막의 표면에 dip coating 방법으로 LSCF를 코팅하였으며 1100 ℃에서 소결하여 치밀성을 갖는 한쪽 끝이 막힌 LSCF coated BSCF 중공사막을 제조하였다. 분리막의 공급측은 대기 중 공기를 사용하였으며 투과측은 진공상태를 유지하였다. 투과된 기체의 유량 및 산소의 농도를 측정하였으며 장기투과 실험과 EDS 분석을 통해 분리막의 안정성 평가를 진행하였다.
        8.
        1985.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        낙동강하류(洛東江下流)의 순(純)갈대초지(草地)에 있어서 현존량(現存量)의 계절적(季節的) 변화(變化), 최대현존량(最大現存量)의 년별변화(年別變化), 물질생산구조(物質生産構造)의 계절변화(季節變化) 및 년순생산성(年純生産性)을 평가(評價)한 결과(結果)는 다음과 같다. 1. 순갈대초지(草地)의 최대현존량(最大現存量)은 9월(月) 중순(中旬)에 나타났으며 평균(平均) 최대일물질생산성(最大日物質生産成)은 6월(月)과 7월(月)사이로 32.7g/m2/d
        4,000원