• 한국자기학회:학술대회 개요집
• /
• 한국자기학회 2013년도 임시총회 및 하계학술연구발표회
• /
• pp.28-28
• /
• 2013

• Bulletin of the Korean Chemical Society
• /
• 제28권4호
• /
• pp.695-697
• /
• 2007

• Bulletin of the Korean Chemical Society
• /
• 제28권5호
• /
• pp.863-866
• /
• 2007

• Maxillofacial Plastic and Reconstructive Surgery
• /
• 제40권
• /
• pp.28.1-28.2
• /
• 2018

• 대한지역사회영양학회지
• /
• 제28권6호
• /
• pp.447-448
• /
• 2023

• Environmental Analysis Health and Toxicology
• /
• 제31권
• /
• pp.2.1-2.4
• /
• 2016

Objectives In this study, we investigated the biodegradation features of 4 perfluorooctanesulfonate (PFOS) alternatives developed at Changwon National University compared to those of PFOS. Methods Biodegradation testing was performed with microorganisms cultured in the good laboratory practice laboratory of the Korea Environment Corporation for 28 days following the Organization for Economic Cooperation and Development guidelines for the testing of chemicals (Test No. 301 C). Results While $C_8F_{17}SO_3Na$, PFOS sodium salt was not degraded after 28 days, the 4 alternatives were biodegraded at the rates of 20.9% for $C_{15}F_9H_{21}S_2O_8Na_2$, 8.4% for $C_{17}F_9H_{25}S_2O_8Na_2$, 22.6% for $C_{23}F_{18}H_{28}S_2O_8Na_2$, and 23.6% for $C_{25}F_{17}H_{32}O_{13}S_3Na_3$. Conclusions $C_{25}F_{17}H_{32}S_3O_{13}Na_3$, $C_{23}F_{18}H_{28}S_2O_8Na_2$, and $C_{15}F_9H_{21}S_2O_8Na_2$ were superior to PFOS in terms of biodegradation rates and surface tension, and thus they were considered highly applicable as PFOS alternatives. Environmental toxicity, human toxicity, and economic feasibility of these compounds should be investigated prior to their commercialization.

• 한국항공운항학회지
• /
• 제28권2호
• /
• pp.18-28
• /
• 2020

This paper has studied the effect of airline staff's perception on both aviation safety and aviation security to their organizational effectiveness. Airline staff's perception on aviation safety is different from that on aviation security due to organizational difference in an airline. Through an empirical analysis, it was analyzed the effect of such perceptional difference on airline's organizational effectiveness. According to the analysis, it was found the perception of aviation safety has a significant positive effect on organizational effectiveness. Airline staff believed the safety is a core value of an airline and emphasizing the safety never impeded the airline's operation including service quality. Secondly, it was proven the perception on abiding by aviation security rules had a significant negative effect on organizational effectiveness. However, emphasizing aviation security had a very significant positive contribution on airline's philosophy of aviation safety. Following the research results, it was suggested an airline look for improving the process and regulations to deal with aviation security in the organization.

• 대한가정학회지
• /
• 제18권1호
• /
• pp.83-95
• /
• 1980

The purpose of this study is to investigate the reasons of Object Attachment Occurrence in infant and the meanings of it in his early development. For this purpose, the following hypotheses were supposed. 1. Infant's object Attachment will be a substitutional for mother attachment when he has opportunities to his mother during his first years. 2. Infant's Object Attachment will not impede the infant's normal development. In order to test this hypotheses 28 mothers whose infants show or have shown this phenomenon and 28 mothers whose infants show or have shown this phenomenon and 28 mothers whose infants do not show this one were interviewed about their child rearing practice and attitude. They were selected by the random sampling method from 310 household wives living at a delux Apt. in Seoul. The results obtained in this study are as follow ; 1. The less opportunities infant has for 1) his mother's breast feeding 2) having physical contact with his mother 3) spending time with his mother 4) receiving prompt response from his mother to his crying, the more he is apt to show this phenomenon. And infant whose first main attachment figure is not his mother also shows the same apt. 2. There was no difference between two groups in intelligence and personality. So it can be concluded that infant's Object Attachment is a substitutional phenomenon for mother attachment in the mother during his first years, and it does not impede infant's normal development.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 1991년도 추계학술대회 논문집
• /
• pp.56-59
• /
• 1991

The polyervstalline $Cu_{0.28}Ag_{0.72}InSe_{4.4}S_{0.6}$ thin films are prepared by vacuum heat treatment of laver, which is deposited by direct resisting vacuum evaporation. From optical absorption spetra, the optical hand gap energy is determined to be 1.5[eV] at room temerature. From electrical method. hole concentration, resistivity and mobility are 9.3*$10^{18}$[$cm^{-3}$], 6*$10^{-2}$[$\Omega$$.$cm], 11.2[$\textrm{cm}^2$/V$.$sec] respectively at room temperature.

• Parasites, Hosts and Diseases
• /
• 제42권2호
• /
• pp.71-75
• /
• 2004

To determine the molecular phylogenie location of Plagiorchis muris, 28S D1 ribosomal DNA (rDNA) and mitochondrial cytochrome C oxidase subunit I (mtCOI) were sequenced and compared with other trematodes in the family Plagiorchiidae. The 28S D1 tree of P. muris was found to be closely related to those of P. elegans and other Plagiorchis species. And, the mtCOI tree also showed that P. muris is in a separate clade with genus Glypthelmins. These results support a phylogenie relationship between members of the Plagiorchiidae, as suggested by morphologic features.