http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Lee, M.,Hwang, Y.K.,Chang, J.S.,Chae, H.J.,Hwang, D.W. Elsevier 2016 CATALYSIS COMMUNICATIONS - Vol.84 No.-
A Ni-Cu-SiO<SUB>2</SUB> nanocomposite was studied as a catalyst for vapor-phase glycerol hydrogenation to produce 1,2-propanediol (1,2-PDO). Substitution of a small amount (3wt%) of Ni for Cu is beneficial for decreasing the Cu particle size, which would be advantageous for attaining higher 1,2-PDO selectivity and higher glycerol conversion. 92% 1,2-PDO selectivity and 100% glycerol conversion were obtained at 220<SUP>o</SUP>C, 30bar, and a weight hourly space velocity of 0.5h<SUP>-1</SUP> over Ni(3)-Cu(77)-SiO<SUB>2,</SUB> which were nearly identical to those obtained with the conventional copper chromite (CuO-Cr<SUB>2</SUB>O<SUB>3</SUB>) catalyst. Therefore, the present Ni(3)-Cu(77)-SiO<SUB>2</SUB> nanocomposite is regarded as a green and efficient catalyst for glycerol conversion into more valuable 1,2-PDO.
Lee, M.,Park, H.S.,Park, J.H.,Moriyama, K.,Kim, M.H. Elsevier 2019 International journal of multiphase flow Vol.118 No.-
<P><B>Abstract</B></P> <P>The effect of interfacial friction at a high void fraction on the estimation of the dryout heat flux (DHF) of particle beds under co-current two-phase flow conditions is investigated. The objective is to reduce uncertainties in the assessment of debris bed coolability during a severe accident in a light water reactor (LWR).</P> <P>A review of porous media air/water pressure drop experiments and friction models in the literature revealed that the existing models cannot adequately predict the interfacial friction at high void fraction. In this study, interfacial friction at high void fraction is suggested and corresponding modifications to the flow pattern map and other friction terms are presented. The proposed model shows an acceptable agreement with the experimental data of both the air/water two-phase pressure drop and DHF experimental results within the particle size range of 2–4 mm, similar to the average diameter of debris particles (2.5–3.5 mm, Hong and An, 2018) obtained from fuel coolant interaction tests.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Improvement of two-phase friction model for high void fraction range in porous media. </LI> <LI> Modified flow pattern map for channel and annular flow in porous media. </LI> <LI> Model validation with air-water two-phase pressure drop and dryout experimental data in porous media. </LI> </UL> </P>
A function-based user authority delegation model
Lee, M.,Cho, N.D.,Gatton, T.M. North-Holland [etc ; Elsevier Science Ltd 2010 Information sciences Vol.180 No.5
User authority delegation is granting or withdrawing access to computer-based information by entities that own and/or control that information. These entities must consider who should be granted access to specific information in the organization and determine reasonable authority delegation. Role Based Access Control (RBAC) delegation management, where user access authority is granted for the minimum resources necessary for users to perform their tasks, is not suitable for the actual working environment of an organization. Currently, RBAC implementations cannot correctly model inheritance and rules for different delegations are in conflict. Further, these systems require that user roles, positions, and information access be continuously and accurately updated, resulting in a manual, error-prone access delegation system. This paper presents a proposal for a new authority delegation model, which allows users to identify their own function-based delegation requirements as the initial input to the RBAC process. The conditions for delegations are identified and functions to implement these delegations are defined. The criteria for basic authority delegation, authentication and constraints are quantified and formulated for evaluation. An analysis of the proposed model is presented showing that this approach both minimizes errors in delegating authority and is more suitable for authority delegation administration in real organizational applications.
Gene delivery to pancreatic islets for effective transplantation in diabetic animal
Lee, M.,Kim, M.J.,Oh, J.,Piao, C.,Park, Y.W.,Lee, D.Y. THE KOREAN SOCIETY OF INDUSTRIAL AND ENGINEERING 2017 JOURNAL OF INDUSTRIAL AND ENGINEERING CHEMISTRY -S Vol.56 No.-
<P>Pancreas islet transplantation is a promising approach to cure diabetes mellitus. However, transplanted islets are easily damaged by hypoxic microenvironment and immunosuppressive agents. Cytoprotective gene delivery into islets could overcome those challenges by expressing the transferred therapeutic genes. In this circumstance, several factors need to be considered for genetic modification of pancreas islets. First, safe and efficient gene delivery tools should be developed. Second, effective therapeutic genes with few side-effects should be developed. Furthermore, strong gene regulation and expression systems are required. Therefore, we here review various gene-carriers and therapeutic genes for genetic engineering of pancreatic islets ex vivo. (C) 2017 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.</P>