• International Journal of Safety
• /
• v.9 no.1
• /
• pp.43-46
• /
• 2010

In the recycle process of organic solvent, the atmospheric oxygen can cause autoxidation and product peroxide. The time-saving method to evaluate the hazards has been required. In this study, oxygen pressure monitoring experiment was proposed as a new method to evaluate autoxidative resistances of solvents. Some of organic solvents were pressurized by oxygen and kept under isothermal condition. At the same time, the pressure in the vessel tracked. Iodometrical titration, thermal analysis and spectroscopic analysis were performed to measure peroxide concentration, the heat of reaction and chemical bonding change. From the results that THF has larger oxygen consumption rate than CPME, it is considered that autoxidative resistance of THF is lower than that of CPME. This method enables to obtain results in shorter time than other methods. These experimental results were consistent with the previous research with longer test durations [1-2].

• Analytical Science and Technology
• /
• v.28 no.3
• /
• pp.212-220
• /
• 2015

This study aims to identify the characteristics of phthalates (DMP, DEP, DBP, DEHA, BBP, DEHP, and DNOP) and heavy metals such as lead (Pb), cadmium (Cd), and mercury (Hg) in cosmetics and their containers. Phthalates and heavy metals may be endocrine distruptors. Sixty-five cosmetics were purchased from online and offline stores in Busan. This study developed a simultaneous method for the analysis of phthalates by GC-FID. The results showed that among the 65 cosmetics, DBP, DEHP, and DEP were detected at 20.0%, 7.7%, 1.5%, respectively. The amounts of DBP and DEHP detected in 18 samples were less than 100 μg/g, which satisfies the Regulations of Cosmetic Safety Standards in Korea. In order to detect phthalates in cosmetic containers, a dissolution test was conducted by extracting solutions, such as water, n-heptane, 20% ethanol, 50% ethanol and 4% acetic acid, which were prepared with different levels of pH, alcohol content, and fat content following the Korea Standards and Specifications for Utensils, Containers, and Packaging. The results showed that DMP, DBP, DEHA, BBP, DEHP, and DNOP were not detected, DEP was detected in plastics such as PE, PP, and others, when a 50% alcohol solvent was used. Phthalates may not be detected in cosmetic containers if they are not packaged with the above 20% alcohol constituent. We also analyzed the concentration of heavy metals, such as Pb, Cd, and Hg, by using ICP-OES and a mercury analyzer. The ranges of concentration were ND~2.71 μg/g for Pb, ND~0.31 μg/g for Cd, and ND~0.01 μg/g for Hg, which are below the regulated level.

• Journal of Life Science
• /
• v.20 no.3
• /
• pp.365-373
• /
• 2010

To monitor newly emerged influenza virus variants and to investigate the prevalence pattern, our laboratory performed isolation of the viruses from surveillance sentinel hospitals. In the present study, we analysed influenza A/H1N1, A/H3N2, B viruses isolated in Busan during the 2006/07 and 2007/08 seasons by sequence analysis of the hemagglutinin (HA1 subunit) and neuraminidase (NA) genes. The isolates studied here were selected by the stratified random sample method from a total of 277 isolates, in which 15 were A/H1N1, 16 were A/H3N2 and 29 were B. Based on the phylogenetic tree, the HA1 gene showed that A/H1N1 isolates had a 96.7% to 97.7% homology with the A/Brisbane/59/2007, A/H3N2 isolates had a 98.4% to 99.7% homology with the A/Brisbane/10/2007, and B isolates had a 96.5% to 99.7% homology with the B/Florida/4/2006(Yamagata lineage), which are all the vaccine strains for the Northern Hemisphere in 2008~2009 season. In the case of the NA gene, A/H1N1 isolates had 97.8% to 98.5% homologies, A/H3N2 isolates had 98.9% to 99.4% homologies, and B isolates had 98.9% to 100% homologies with each vaccine strain in the 2008~2009 season, respectively. Characterization of the hemagglutinin gene revealed that amino acids at the receptor-binding site and N-linked glycosylation site were highly conserved. These results provide useful information for the control of influenza viruses in Busan and for a better understanding of vaccine strain selection.

• Journal of the Korean Home Economics Association
• /
• v.47 no.9
• /
• pp.27-36
• /
• 2009

The purpose of this study to gather information on demographic statistics, children’s attachment to their mothers, and daily stress variants in order to assess their effects on child’s self-concept and depression within multi-ethnic familiy settings. A questionnaire survey was used to targeted 3rd, 4th, 5th and 6th graders in elementary schools in Jeonnam. A total of 158 children were surveyed. SPSS for Windows 12.0 was used to carry out descriptive, and comparative statistical analysis such as Cronbach's $\alpha$, correlations analysis, and a hierarchical regression analysis. Result showed that the most significant variant affecting self-concept among children from multi-ethnic families was attachment to their mothers. Other related individual variants were in order of importance, communication skills, feelings of alienation, and mothers’ nationalities. The variant most responsible for having an affect on depression among children from multi-entnic families was the attachment to their mothers. Other related individual variants were in order of importance, feelings of alienation, stress from peer relationships, mothers’ nationalities, and stress from economic and physical environments.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2001.11b
• /
• pp.622-627
• /
• 2001

The paper presents the possibilities of a wide practical application of the modal analysis methods in dynamic testing of vertical pump. A pneumatic impact of testing vertical pumps submerged under deep water was developed and successfully applied. The problem with the enviroment is the it causes significants changes in modal parameters, compared with those in the airenviroment.

• Journal of the Korean Home Economics Association
• /
• v.45 no.6
• /
• pp.89-100
• /
• 2007

The objective of this study was to analyze children's maladjustment behavior as related to sex, temperament, and the mother's maternal attitudes, and to characterize the relative influence of these variables on the maladjustment behavior of 3-5 year old children in early child education centers. The subjects were recruited from Gwangju City, and included 217 mothers, and the teachers of their children. Statistical analyses were conducted using SPSSWIN(12.0) for Cronbach's alpha, t-test, one-way ANOVA, Pearson's correlation, and multiple regression analysis. The major findings are as follows; 1. Statistically significant differences existed in the maternal overprotective attitude group with regard to anxiety and withdrawal behaviors. 2. Boys evidenced more aggression, inattention, impulse, and anxiety behaviors than did girls. 3. The activity and adaptation factors of temperaments were significantly different. Increasing activity was associated with increasing aggressive behavior. Increasing adaptation was associated with higher levels of distraction. 4. In terms of maladjustment behaviors in the aggregate, the sex of the children appeared to be the most salient influencing factor, and the activity factor of children's temperament also exerted a significant influence, explaining 13% of maladjustment behavior.

• Journal of Soil and Groundwater Environment
• /
• v.16 no.6
• /
• pp.95-105
• /
• 2011

Total extraction method and environmental standards for heavy metals in soils were revised in regulation recently. In case of Area 3, as the law amended, the soil pollution level has gone up to 4 to 13 times higher depending on the type of heavy metal. In this study, it compares the properties of heavy metals of soil by sequential extraction and total extraction methods depending on the analysis method, using the soil around mine. In case of arsenic, the soil pollution level has gone up to 4 times higher, but 6 to 10 times in the sample soil. Also, according to the results of portability evaluation depending on the type of existence form of heavy metal it exists as residual form in mine waste rock, which is less likely to move, while it exists as migrated form in tailing. Therefore, it should be considered to evaluate the soil pollution and decide the contaminated bounds depending on the existence form of heavy metals on soil to restore the polluted soil.

• Journal of Industrial Technology
• /
• v.12
• /
• pp.37-49
• /
• 1992

We proposed an integrated simulator scheme for communication networks. The network modeling and Analysis methologies are firstly discussed along the design procedure of a network simulator, and then, the structure, kernel, and user interfaces are defined for the simulator. Finally, for the verification of our approach, simulations are performed for a simple queueing network and a pure ALOHA system using Ptolemy, a multi-paradigm simulation enviroment.

• Journal of the Korean earth science society
• /
• v.22 no.6
• /
• pp.480-490
• /
• 2001

The soil-air exchange processes of Hg were investigated from the Hari area of Kang Hwa Island during the late March 2001. In the course of our study, we determined the concentration gradients of Hg and combined these gradient data with micrometeorological components to derive its fluxes. Results of our study indicate that the concentration levels of Hg in the study area are notably lower than those typically found in urbanized areas of Korea. However, the computed fluxes were seen to be significantly larger for relatively remote areas, reaching over 200 ng/m$^2$/hr. Comparison of environmental conditions shows that the concentrations of most pollutant species including NO$_X$ and PM were significantly higher during emission, while meteorological conditions were characterized by high temperature and low humidity. Results of correlation analysis also indicate that such pollutants as hydrocarbons, nitrogen oxides, and PM generally exhibit strong positive correlations with Hg-related parameters during emission events, while such relationships were reversed during dry deposition events. The results of our present study suggest the possibility that the concentrations and fluxes of total gaseous Hg observed during deposition events can be influenced by the processes that are also important for the fine, rather than coarse, size fraction of particles.

• Korean Journal of Microbiology
• /
• v.41 no.1
• /
• pp.53-59
• /
• 2005

Influenza is an important public health problem which occurs almost every winter in temperate climates and is often associated with increased rates of hospitalization and death. In 1999, our influenza surveillance was initiated with 4 voluntary sentinel physicians and the Public Health Center. During the 2003-2004 influenza season, 124 influenza viruses were isolated from 401 clinical specimens, which were collected from patients with Influenza-like illness(ILI) in Seoul. The case definition of ILI is a case with fever more than $38^{\circ}C$ and systemic symptoms; cough, or sore throat. ILI was the highest at the 20-49 age $group(23\%)$ and the rate of virus isolation was the highest at the 7-19 age $group(50\%)$. Among 124 influenza viruses, isolates 83 were identified as A/H3N2 type and others were subtyped as influenza B viruses in 2003-2004 season. Influenza viruses were collected $39.1\%$ at Nowon-Gu, $13.5\%$ Gangnam-Gu and Seocho-Gu etc. and the isolate rate of virus had the area difference; Yongsan-Gu $66.7\%$, Gangnam-gu $50.0\%$, Nowon-Gu $39.9\%$, Kangbuk-Gu $36.8\%$, Seocho-Gu $27.8\%$, Dongjak-Gu $21.2\%$. Out of 401 individuals, 160 was vaccinated $(40\%)$ and the vaccination rate was the highest at the 20-49 age $group(32\%)$. These findings may contribute to the recommondation of the influenza vaccine formulation and the development of influenza control measure.