• Environmental Analysis Health and Toxicology
• /
• v.5 no.3_4
• /
• pp.19-28
• /
• 1990

Nitroarenes are ubiquitous environmental pollutants displaying potent mutagenicity in bacteria and carcinogenicity in mammal. In this study, the concentration of nitroarenes in coarse and fine particles and mutagenicity of POC$\_$N/ fraction was investigated in suspended particulates at the Shinchon and Bulkwang area of Seoul. The suspended particulates were collected bimonthly by a high volume cascade impactor air sampler from July 1987 to May 1988. Extractable organic matter was obtained by ultrasonic extraction on diethly ether/cyclohexane (8/2, v/v). Neutral fraction was obtained by liquid-liquid extraction. Polar neutral organic compounds (POC$\_$N/) was fractionated by thin-layer chromatography. Finally, the concentrations of nitroarenes in POC$\_$N/ fraction were measured and determined by capillary gas chromatography. Direct and indirect mutagenicity of POC$\_$N/ fraction were measured using Salmonella typhimurium TA 98. The result were as follows: 1) Major nitroarenes at the Shinchon area was 1-nitropyrene and at the Bulkwang area it was 2,7-dinitro-9-fluorenone during the year. 2) Average concentration of total nitroarenes measured was 67.26 ng/m$^3$in fine particles which was 1,3 folds higher that in coarse particle (52.30 ng/m$^3$). 3) Annual pattern of nitroarenes concentrations revealed that concentration during heating season (Feb., Jan., Mar.) was 2.2 folds higher than that in non heating season (May, Jul., Sep.). Concentration of each season has 157.68 ng/m$^3$and 80.39 ng/m$^3$. 4) The mutagenic activity of POC$\_$N/ fraction from fine particles was higher compared to that of coarse particles and was increased when metabolically activated, with 59 mixture. Mutagenicities, Metabolically activated, were significantly different between Shinchon and Bulkwang area, 322.8 rev/250 $\mu\textrm{g}$/plate and 286.8 rev/250 $\mu\textrm{g}$/plate, respectively. 5) Annual pattern of mutagenicity of POC$\_$N/ fraction revealed that mutagenicity during the heating season was 1.7 folds higher at Shinchon area and 1.2 folds higher at Bulkwang than during the non heating season. The variable contents and levels of nitroarenes in suspended particulates may affect human health significantly. Further studies such as risk assessment should be conducted on the basis of these kind of studies.

• Analytical Science and Technology
• /
• v.24 no.3
• /
• pp.200-211
• /
• 2011

In this study, 13 compounds including four volatile fatty acids (VFA) and nine volatile organic compounds (VOC) were analyzed by cryogenic trapping-thermal desorption technique. In order to evaluate the analytical method for VFA, calibration experiments were performed using five different sorbent materials. When the calibration results are compared between different sorbents, sampling tube filled with Carbopack X showed the highest response factor (RF) for both VFA and VOC. To validate this new analytical method for VFA using cryogenic trapping-thermal desorption technique, this method was compared with alkali absorption method recommended by the odor prevention law of the Korea Ministry of Environment (KMOE). For this purpose, unknown samples were analyzed by two different methods, i.e., cryogenic trapping-thermal desorption (TD) and alkali absorption with solid phase microextraction (SPME). When the results of two different methods were compared, ratios of concentrations determined by the two analytical methods (TD/SPME) was found as 0.46 (valeric acid) ~ 0.71 (isovaleric acid). Therefore, additional study is required to properly establish and find stable analytical conditions for VFA analysis. Furthermore, comparison between two different methods should be made with more reliable calibration approaches.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.10 no.11
• /
• pp.3458-3464
• /
• 2009

This study was conducted to investigate the relationship between maximum oxygen uptake and its related factors including body measurement and vascular compliance. The subjects of our study were 43 males and 53 females aged 40 to 59 who were visited in military health center. The main results were that 1.the degree of obesity had significantly negative correlation to vascular compliance in male, and waist-hip ratio in female. 2. The degree of obesity, body mass index, waist-hip ratio and body fat percent had significantly negative correlation to maximum oxygen uptake in male, and waist-hip ratio & body fat percent in female. 3. Maximum heart rate had significantly positive correlation to maximum oxygen uptake in male, and vascular compliance & maximum heart rate in female. 4. In multiple regression analysis which maximum oxygen uptake was as dependent variable, body fat percent, vascular compliance and maximum heart rate were significant variables for both male and female. In conclusion, Maximum oxygen uptake of some rural people age 40 to 59 were affected by various factors such as body fat percent, vascular compliance, and maximum heart rate.

• Korean Journal of Applied Biomechanics
• /
• v.19 no.2
• /
• pp.347-357
• /
• 2009

The purpose of this study was to compare EMG and GRF during a free throw. Seven pairs of surface electrodes were attached to the right-hand side of the body to monitor the flexor carpi radialis (FC), extensor carpi radialis longus (EC), biceps brachii (BB), triceps brachii (TB), rectus femoris (RF), tibialis anterior (TA) and medial gastrocnemius (GM). GRF data from two force platform were collected during a free throw. The results showed that the muscle activities in the unskilled group must be highly activated prior to the moment of release. This means that a skilled participant can shoot a free throw more efficiently while producing less muscle activeness than an unskilled participant. The DCP of unskilled group in the medio-lateral direction were greater than the corresponding values in skilled group. This showed that the unskilled group were not able to shoot the free throws stably. Thus, when a teacher or instructor teaches students how to shoot free throw, it is considered that the teacher show the learner how to use not only the upper limbs but also lower limbs on the basis of the efficent connecting movement and the flexibility in a stable procedure.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2008.06a
• /
• pp.477-477
• /
• 2008

For more than three decades, the gate dielectrics in CMOS devices are $SiO_2$ because of its blocking properties of current in insulated gate FET channels. As the dimensions of feature size have been scaled down (width and the thickness is reduced down to 50 urn and 2 urn or less), gate leakage current is increased and reliability of $SiO_2$ is reduced. Many metal oxides such as $TiO_2$, $Ta_2O_4$, $SrTiO_3$, $Al_2O_3$, $HfO_2$ and $ZrO_2$ have been challenged for memory devices. These materials posses relatively high dielectric constant, but $HfO_2$ and $Al_2O_3$ did not provide sufficient advantages over $SiO_2$ or $Si_3N_4$ because of reaction with Si substrate. Recently, $HfO_2$ have been attracted attention because Hf forms the most stable oxide with the highest heat of formation. In addition, Hf can reduce the native oxide layer by creating $HfO_2$. However, new gate oxide candidates must satisfy a standard CMOS process. In order to fabricate high density memories with small feature size, the plasma etch process should be developed by well understanding and optimizing plasma behaviors. Therefore, it is necessary that the etch behavior of $HfO_2$ and plasma parameters are systematically investigated as functions of process parameters including gas mixing ratio, rf power, pressure and temperature to determine the mechanism of plasma induced damage. However, there is few studies on the the etch mechanism and the surface reactions in $BCl_3$ based plasma to etch $HfO_2$ thin films. In this work, the samples of $HfO_2$ were prepared on Si wafer with using atomic layer deposition. In our previous work, the maximum etch rate of $BCl_3$/Ar were obtained 20% $BCl_3$/ 80% Ar. Over 20% $BCl_3$ addition, the etch rate of $HfO_2$ decreased. The etching rate of $HfO_2$ and selectivity of $HfO_2$ to Si were investigated with using in inductively coupled plasma etching system (ICP) and $BCl_3/Cl_2$/Ar plasma. The change of volume densities of radical and atoms were monitored with using optical emission spectroscopy analysis (OES). The variations of components of etched surfaces for $HfO_2$ was investigated with using x-ray photo electron spectroscopy (XPS). In order to investigate the accumulation of etch by products during etch process, the exposed surface of $HfO_2$ in $BCl_3/Cl_2$/Ar plasma was compared with surface of as-doped $HfO_2$ and all the surfaces of samples were examined with field emission scanning electron microscopy and atomic force microscope (AFM).

• Economic and Environmental Geology
• /
• v.50 no.3
• /
• pp.181-193
• /
• 2017

Mn-Fe phosphate mineral complexes included within the pegmatite are observed at Jurassic Cheolwon two-mica granite in Gyeonggi Massif, South Korea. The genetic evolution between the Cheolwon two-mica granite and pegmatite, and various trend of Mn-Fe phosphate minerals is made by later magmatic, hydrothermal, and weathering process based on mineralogical, geochemical analysis. The Cheolwon two-mica granite is identified as S-type granite, considering its chemical composition (metaluminous ~ peraluminous), post-collisional environment, low magnetic susceptibility, and existence of biotite and muscovite. The K-Ar age (ca. 153 Ma) of pegmatite is well coincident with age of the Cheolwon two-mica granite ($151{\pm}4Ma$). It indicates that these two rocks are originated from the same magma. Pegmatite indicates the LCT geochemical signature, and was classified as muscovite-rare element class / Li subclass / beryl type / beryl-columbite-phosphate subtype pegmatite. The triplite $\{(Fe^{2+}{_{0.4}},Mn_{1.6})(PO_4)(F_{0.9})\}$ is dominant phosphates in later magmatic stage which partly altered to leucophosphite $\{KFe^{3+}{_2}(PO_4)_2OH{\cdot}2H_2O\}$ and jahnsite $\{(Fe^{3+}{_{0.7}},Mn_{2.3})(PO_4)_2OH{\cdot}4H_2O\}$ by hydrothermal alteration. In particular, near fractures, the triplite has been separatelty replaced by the phosphosiderite ($Fe^{3+}PO_4{\cdot}2H_2O$) and Mn-oxide minerals during weathering stage.

• The Korean Journal of Mycology
• /
• v.38 no.1
• /
• pp.34-39
• /
• 2010

We have attempted to verify 30 strains of Hypsizigus marmoreus from various mushroom stocks in Korea using random amplified polymorphic DNA (RAPD) methodology. Chromosomal DNAs of them were extracted and subjected to PCR analyses with 3 random primers. Each PCR produced approximately 30 distinct PCR bands with the size from 200 bp to 3000 bp. A dendrogram was acquired using the unweighted pair-group method with arithmetic average (UPGMA) clustering methodology on the basis of the DNA band pattern. The analysis revealed that 30 strains of H. marmoreus were clustered into two distinct clusters. Cluster 1 contained 3 subgroups while the cluster 2 consisted of rather diverse strains. Interestingly, Hm3-10, a wild strain collected from Deog-Yu mountain, was not included in either clusters, indicative of uniqueness of this strain. We nextly attempted to develop strain-specific DNA markers to verify a specific strain. A unique band in the RAPD gel lane of Hm0-4 was extracted and its sequence was determined. PCR with a primer set from the determined sequence revealed that the primer set gave a 250 bp DNA band only for Hm0-4, indicating that this approach works well for the strain-specific identification of H. marmoreus.

• Journal of Distribution Science
• /
• v.4 no.2
• /
• pp.21-40
• /
• 2006

Small and middle sized Franchise system channels experience conflicts because of constant interaction between franchiser and franchisee. However, it is rarely that attempt has been made to identify causes of conflicts in distribution of franchise industry. The purpose of this study was to explore cause of conflicts from the franchisee. For the study, data were collected from the owner or the shop-manager with a contractor in franchise systems. By means of in-depth interviews with multiple informants, their statement was analyzed qualitatively. From analysis of the resulting data, the causes of conflicts were associated with two broad sets, attitudinal and structural differences between franchisers and franchisees. First, attitudinal sources of conflict were identified as perception of subordinated relationships between channel members, delayed announcement on order changes, difficulties in communication by doing irresponsible behavior, different expectations between channel members in market territory and lack of consistent-supporting. Second, structural sources of conflict involved unilateral decision on interior, payment method, unreasonable delivery issue, treat franchisee with discrimination by the sales, in controlling against free management. There are limitations on generalization due to the results based on interview, but this study will be a useful exploratory step before designing a large scale survey.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.30 no.5
• /
• pp.900-905
• /
• 2001

In this study, the levels of insoluble dietary fiber(IDF) and soluble dietary fiber (SDF) in Perilla frutescens seed were quantified and antimutageinc effects of perilla seeds extracts (method extract, hexane extract, methanol soluble fraction and dietary fiber)was carried out IDF and SDF values of perilla seeds were 16.1% and 1.1% , respectively, with 17.2 of total fiber content. Among the solvent extracts of perilla seeds, methanol extract and methanol soluble fraction (MSF) effectively inhibited the mutagenicity induced by aflatoxin B$_{1}$(AFB$_{1}$)in Salmonella typhimurium TA100, Methanol extract of perilla seeds showed 91% inhibition against AFB$_{1}$ mutagen under the 2.5 mg/assay concentration, and MSF inhibited the mutagenicity of 87% by adding 1.25,g/assay. However, perilla seed extracts showed low inhibition rate on the mutagenicity induced by N-methyl-N-nitro-N-nitosoguanidine(MNNG). And also, SDF and hexane extracts from perilla seeds did not show the antimutagenic effects against AFB$_{1}$ and MNNG. On the hand, IDF extracted from perilla seeds inhibited 21% of mutagenicity induced Trp-P-2 due to the carcinogen binding effect.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.36 no.1
• /
• pp.1-7
• /
• 2007

Antimutagenic and in vitro anticancer effects of doenjangs added with green tea extract and/or using bamboo salt were studied by Ames test using Salmonella enterica serovar Typhimurium (Salmonella Typhimurium) TA100 and 3-(4,5-dimethylthiazol) -2,5-diphenyltetrazolium bromide (MTT) assay on PC-3 and DU145 human prostate cancer cells, respectively. At the 1.25 mg/plate concentration, 1% green tea extract (GTE) added doenjang exhibited 85% antimutagenicity against aflatoxin $B_1$ ($AFB_1$), while the control doenjang revealed 63% antimutagenicity, showing increased antimutagenic effect by the addition of green tea extract during doenjang fermentation. GTE added doenjang also increased antimutagenic effect against MNNG. The inhibition rate of the control doenjang showed 34% at 0.625 mg/plate, while 1% and 2% GTE added doenjangs inhibited by 56% and 73% at the 0.625 and 1.25 mg/plate, respectively (p<0.05). In MTT assay, GTE added doenjangs caused 70% $\sim$ 77% inhibition on the proliferation of PC-3 human prostate cancer cells at 0.5 mg/mL while the control doenjang exhibited 46% inhibition. However, 2% GTE added doenjang showed 91% inhibition at 1.0 mg/mL. The trend of the inhibition rate was similar in DU14S human prostate adenocarcinoma cells. When bamboo salt was used instead of natural sea salt, the antimutagenicity against MNNG and in vitro anticancer effect on the prostate cancer cells greatly increased. From these results, it can be concluded that green tea extract addition to doenjang and the use of bamboo salt during doengjang preparation increased the antimutagenic and in vitro anticancer activities of the doenjang and showed a synergistic effect.