• Korea Trade Review
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• v.43 no.1
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• pp.69-90
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• 2018

Customer demand is rising as services competition becomes more intense among logistics companies. Some large companies provide total logistics services, but most logistics companies provide total logistics services in cooperation with other companies. Therefore, supply chain competition is becoming more important than competition among logistics providers. The purpose of this study is to verify the effects of logistics cooperation and supply chain competence on logistics performance. In this study, we conducted a literature review to identify the key factors that logistics companies consider important, and establish a conceptual research model. A survey was conducted on 286 logistics companies in Korea, and hypotheses were verified based on the structural equation model. The hypotheses test results are as follows. First, logistics cooperation had a significant effect on supply chain competence and logistics performance. Second, logistics performance improves when supply chain competence is strengthened. Third, higher level logistics expertise resulted in greater logistics cooperation effects on logistics performance.

• Applied Chemistry for Engineering
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• v.16 no.6
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• pp.778-784
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• 2005

It has been found that the addition of cosurfactant is necessary in order to expand three phase region containing middle phase microemulsion in ternary systems containing alkyl ethoxylate (AEO) nonionic surfactant, commercial lubricant and water. Phase behavior in the surfactant systems with addition of cosurfactant over a temperature range of 30 to $60^{\circ}C$ showed different trends depending on surfactant, temperature and chain length of alcohol added. For the $C_{12}E_4$ system, addition of n-pentanol and n-hexanol both produced a three phase region over a wide range of temperatures but the middle-phase formed was found to be a $L_3$ or D' phase which would not facilitate solubilization of high molecular weight lubricants. On the other hand, for the $C_{12}E_5$ system, the middle-phase microemulsion was found to be formed with addition of a rather long-chain alcohol such as n-hexanol, n-heptanol, n-octanol, or n-nonanol. The results shown with the addition of cosurfactant was understood in connection with interfacial tension measurements and composition analysis. The inability of the hydrocarbon region of the surfactant films to incorporate the large lubricant molecules and high solubility of a hydrophobic surfactant are thought to be the chief reasons for poor solubilization with D' phase.