• Analytical Science and Technology
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• v.23 no.4
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• pp.331-346
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• 2010

Perfluorinated compounds have characteristics of resistance to heat, acidic, basic conditions and also resist water, oil, grease, pollutant. Futhermore they are used by various industrial material, nowadays, they produced in large scale for indutrial and commercial areas. However, they also resist metabolizing and degrading in environmental system (plant, animal, even human body). Moreover, in animal's bodies, PFCs can be accumulated in organ (eg; liver) and lead to liver cell necrosis even oncogenesis. Perfluorinated compounds are newly registered as new persistent organic pollutants (POPs) on Stockholm convention in 2009. Therefore necessity for analytical methodology for determination of PFCs in various environmental samples is even more increased. This study discussed sample preparation and instrumental conditions for the analysis of PFCs in environmental and biota samples.

• Korean Journal of Ecology and Environment
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• v.39 no.4 s.118
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• pp.419-423
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• 2006

In this study, acute toxicity of four pesticides (diazinon, iprodione, fenproparthrin, and myclobutanil) to Chinese bleak, Aphyocypris chinensis, and to study their adverse effects were conducted in static systems. The 96-hr $LC_{50}$ values were determined, as well as 95% confidence limits. The 96-hr $LC_{50}$ values of these chemicals derived for Chinese bleak were rank ordered from the most toxic to the least toxic technicals as follows: Fenproparthrin (0.003 mg $L^{-1}$)>Myclobutanil (9.1 mg $L^{-1}$)>Diazinon (14.1 mg $L^{-1}$)>Iprodione (31.8 mg $L^{-1}$), The data presented in this study indicate the acute toxicity tests carried out on only one fish species may lead to erroneous determination of water quality criteria and classification of test chemicals for environmental management and regulatory purpose. Therefore, more studies comparing the susceptibility of a variety of fish species to various toxicants are needed.

• Atmosphere
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• v.21 no.1
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• pp.109-121
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• 2011

This study revisits the definition of Changma, which is the major rainy season in Korea and corresponds to a regional component of the East Asian summer monsoon system. In spite of several decades of researches on Changma, questions still remain on many aspects of Changma that include its proper definition, determination of its onset and retreat, and relevant large-scale dynamical and thermodynamical features. Therefore, this study clarifies the definition of Changma (which is a starting point for the study of interannual and interdecadal variability) using a basic concept of air mass and front by calculating equivalent potential temperature (${\theta}_e$) that considers air temperature and humidity simultaneously. A negative peak in the meridional gradient of this quantity signifies the approximate location of Changma front. This front has previously been recognized as the boundary between the tropical North Pacific air mass and cold Okhotsk sea air mass. However, this study identifies three more important air masses affecting Changma: the tropical monsoon air mass related to the intertropical convergence zone over Southeast Asia and South China Sea, the tropical continental air mass over North China, and intermittently polar continental air mass. The variations of these five air masses lead to complicated evolution of Changma and modulate intensity, onset and withdrawal dates, and duration of Changma on the interannual time scale. Importantly, use of ${\theta}_e$, 500-hPa geopotential height and 200 hPa zonal wind fields for determining Changma onset and withdrawal dates results in a significant increase (up to~57%) in the hindcast skill compared to a previous study.

• The Korean Journal of Zoology
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• v.31 no.2
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• pp.133-141
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• 1988

These studies have been carried out to examine the stability of enzyme activity of PGM$_1$subtypes in seminal stains and vaginal stains according to the period of storage time by means of polyacryiamide gel(PAG) isoelectric focusing. The results from the experiments were as follows. (1) The stabflity of enzyme activity of PGM$_1$subtypes was detennined from seminal stains and vaginal stains according to the period of storage time. The PGM$_1$ subtypes of seminal stains stored at room temperature could be detennined 86% after 7 days and 15% after 14 days, but almost impossible after 21 days. (2) In the case of vaginal stains stored at room temperature, PGM$_1$ subtypes could be determined 67% after 7 days, but almost impossible after 14 days. On the other hand, when the vaginal fluid was mixed with seminal fluid, PGM$_1$ subtypes of the seminal fluid could be postulated by the determination of PGM$_1$ subtypes from the vaginal fluid.These results lead to the possibility of application in forensic biology.

• Journal of Digital Convergence
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• v.10 no.11
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• pp.137-144
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• 2012

Seventeen domestic banks, Hongkong & Shanghai Banking Corporation Ltd. and Korea Post provide their subscribers with banking services such as statement service, funds transfer, and application for loans through Internet banking sites, which have become ever-increasing banking services for individual and corporation and government subscribers. First, this study aimed at presenting a process of determining factors to measure customers' perception while using Internet banking for doing transactions. Secondly, this paper attempted to unveil a list of major factors that Internet banking customers perceive while accessing the web sites to do their business with their banks. This study also suggested the features of those factors, which would help improve our understanding of Web usage for Internet banking. This result of the paper will lead further understanding of factors associated with Internet uses in other economic activities, which enable practitioners such as web designers and security specialists to provide Internet banking subscribers with better services in a safe and convenient web pages.

• Journal of the Korean Applied Science and Technology
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• v.33 no.1
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• pp.195-203
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• 2016

Heavy metals have been analyzed on the non-woven from the 24 kinds of wet wipes and 8 kinds of mask packs. The following materials used in the non-woven according to each product are: rayon+polyester for the 12 wet wipe products, rayon+PET for the 5 wet wipe products, and rayon, cotton, rayon+polyester+cotton, pulp+polypropylene for the rest of the wet wipe products. No further information on the materials was found on the 3 wet wipes and 8 mask packs. However, polyester may be applied for the non-woven in wet wipes, because PET is part of the polyester group. The heavy metals analysis in the 24 kinds of wet wipes and 8 kinds of mask packs revealed the following: arsenic was found from $47.14{\pm}1.13$ to $71.75{\pm}1.64{\mu}g/L$ on the 3 products, the amount of nickel in the 2 products were $261.26{\pm}5.14$ and $1,242.63{\pm}43.71{\mu}g/L$, $53.69{\pm}1.45$ and $103.52{\pm}2.02mg/L$ on the 2 mask packs. It was also revealed that lead was detected from $7.23{\pm}0.32$ to $55.67{\pm}1.46{\mu}g/L$ on the 6 wet wipes, antimony was ranged from $187.86{\pm}5.24$ to $19,558.35{\pm}3,537.30{\mu}g/L$ on the 12 wet wipes, and $5.25{\pm}0.25$ and $8,936{\pm}55.22{\mu}g/L$ on the 2 mask packs. No cadmium, mercury, or thallium were detected from all the products. A high concentration of antimony might come from antimony trioxide, which was used as a catalyst when manufacturing the polyester. Therefore, it is strongly recommended that a non-woven used for cosmetic purposes should not use heavy metals as a catalyst when manufacturing, and it's important to clarify which materials are used in non-woven.

• Journal of Oral Medicine and Pain
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• v.19 no.1
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• pp.57-72
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• 1994

This study was undertaken to obtain the data age determination following the eruption of individual cusps of the first molars in the point of forensic odontology. 532 children (294 male and 238 female, born between April, 1989 and March, 1986) from a kindergarten and a primary school in a reesidential district in Seoul were studied. The eruption state of the first molar was divides into 6 stages according to the degree of exposure of individual cusps, and correlation between the stage and age was stastically analysed. The results of the study lead to following conclusions : 1. The most frequently seen eruption sequence of cusps for the upper first molar was mesibuccal cusp, mesiopalatal cusp, distobuccal cusp, mesiodistal cusp, distopalatal cusp. As for the lower first molar : mesiobuccal cusp, mcsiolingual cusp, distobuccal cusp, distolingual cusp. 2. The time of eruption was earlier in the female ethan in the male, but it was stastically remarkable only in upper and lower parts of the right and the left teeth of subjects age between 6.0 and 6.5 and upper part of the right and the left teeth of subjects age over 7.5 3. The eruption of the lower first molar was comparatively earlier than that of the upper first molar and there was no significant stastical difference between the right and the left first molars in the time of eruption. 4. There was no noticeable difference in the eruption sequence of cusps, irrespective of sex and side. 5. The eruption of the upper first molar is started at the age of about 6.4 and complete the age of about 7.1 and as for the lower first molar, it is from 6.3 to 7.0

• Journal of the Korean Chemical Society
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• v.47 no.1
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• pp.38-42
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• 2003

For the purpose of developing new agrochemical fungicides, compound 2 possessing 1,3-thiazole scaffold as well as urea moiety in the structure was designed through molecular modification of lead compound, 2-imino-1,3-thiazoline based on isosterism. The reaction of N-methylthiouea 5 and bromoacetonitrile in ethanol gave 2,4-diimino-1,3-thiazole 4 regioselectively, which was treated with phenyl isocyanates to give the corresponding 7 which is tautomer of 2. The structural assignment of 7 was confirmed by various spectra($^1H$ NMR, $^{13}C$ NMR, FT-IR, HRMS), and X-ray crystallographic data. Compound 8 which is a structural isomer of 7 was formed through thermodynamically unstable intermediate 2,4-diimino-1,3-thiazole 6.

• The KSFM Journal of Fluid Machinery
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• v.16 no.4
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• pp.35-43
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• 2013

Most of the nuclear power plants(NPPs) adopts pressure difference type flow meters such as venturi and orifice meters for the measurement of feedwater flow rates to calculate reactor thermal power. However, corrosion products in the feedwater deposits on the flow meter by fouling as operating time goes. These effects lead to severe errors in the flow indication and then determination of reactor thermal power. The averaging BDFT, which has developed by Yun et al., has a potentiality to minimize this problem thanks to its inherent measurement principle. Therefore, it is expected that the averaging BDFT can replace the venturi meter for the feedwater pipe of steam generator of NPPs. The present work compares the amplification factor, K, based on CFD calculation against the K obtained from experiments in order to confirm whether a commercial CFD code can be applicable to the evaluation of characteristic for the averaging BDFT. In addition to this, the simulations to take into account of fouling effect are also carried out by rough wall option. The results show that the averaging BDFT is a promising flow meter for the accurate measurement of flow rates in the fouling condition of the NPPs.

• Journal of Oriental Neuropsychiatry
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• v.3 no.2
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• pp.1-33
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• 1992

In order to observe clinical effect of Gamikeguntang(加味柱芎湯) and Gamikuyibitang(加味歸脾湯), I reached following conclusion through the clinical pathology and physicohemical investigation, The following results were obtained. 1) The amplirude on AVL lead which is observed in ECG was increased significantly both in medication group of Gamikegungtang (加味柱芎湯) and of Gamikegungtang(加味歸脾湯). 2) In Hematology, the values of RBC, Hb and Hct are totally increased in the medication group of Gamikuyibitang(加味歸脾湯). 3) In serum Lipid, Total cholesterol and Tryglyceride are significantly decreased and HDL-cholesteral is significantly increased both in medication group of Gamikegungtang(加味柱芎湯) and Gamikuyibitang(加味歸脾湯). Especiay, HDL-cholesterol is remarkably increased in the medication group of Gamikegungtang(加味柱芎湯). 4) The serum Bile acid is remarkably decreased in the medication group of Gamikegungtang(加味柱芎湯), but is not in the medication group of Gamikuyibitang(加味歸脾湯). 5) The value of Cardiac enzyme is remarkably decreased both in the medication group of Gamikegungtang(加味柱芎湯) and Gamikuyibitnag(加味歸脾湯). especially, in the group of Gamikuybitang(加味歸脾湯). 6) In determination of LDH isoenzyme, $LD_4$ is remarkably decreased in the medication group of Gamikegungtang(加味柱芎湯) and $LD_1\;LD_2$ are remarkably decreased in the medication group of Gamikuyibitang(加味歸脾湯). In view of the result so far achieved, I knew that Gamikegungtang(加味柱芎湯) had an indirect effect on Palpitation which is called mental disorder by means of treatment of liver and gall bladder disease, and that Gamiluyibitang(加味歸脾湯) make increase activation of heart whose blood is deficient( 心血不足). In conclusion, I think that we need comparative studies between the main prescription of Kegungtang(柱芎湯). Kuyibitnag(歸脾湯) and the additional prescription of them from now on.