• Proceedings of the Korea Air Pollution Research Association Conference
• /
• 2010.04a
• /
• pp.322-326
• /
• 2010

This study shows that atmospheric TPM concentrations and THg concentrations in precipitation measured in China were higher that those measured in Korea. TPM concentrations and THg concentrations in precipitation during the cold periods were generally higher than those during the warm periods in both China and korea. In China, variations of THg concentration in precipitation during the cold and warm periods were influenced by scavenging of both TPM and RGM. Different from China, in Korea, variations of THg concentration in precipitation during the cold period were also influenced by scavenging of both TPM and RGM; however, those during the warm periods were dominantly governed by scavenging of RGM.

• Proceedings of the Korea Concrete Institute Conference
• /
• 1999.04a
• /
• pp.443-448
• /
• 1999

Tests have been carried out on four concrete containing different levels of silica fume to measure their permeability coefficient using water and oxygen, chloride ion. The total cementitious content was 351kg/㎥, and the water/cementitious materials ratio was 0.55. The results show that a dramatic reduction in permeability of concrete containing silica fume occurs due to formation of a discontinuous macro-pore system which inhibits flow. Porosity estimates from mercury-intrusion porosimetry are used to develop an explanations for the water and air permeability reduction. And, results of the rapid permeability test showed that the resistance of concrete to the penetration of chloride ions increases significantly as a contents of silica-fume is increased. The current intensity passing through the concrete containing silica fume is presented from 664C to 2166C.

• Geomechanics and Engineering
• /
• v.23 no.5
• /
• pp.431-439
• /
• 2020

Soil-water retention curve (SWRC) contains key information for the application of unsaturated soil mechanics principles to engineering practice. The SWRC variables are commonly used to describe the hydro-mechanics of soils. Generally, these parameters are determined using the graphical method which can be time consuming. The SWRC is highly dependent on the pore size distribution (PSD). Theoretically, the PSD obtained by mercury intrusion porosimetry test can be used to determine some SWRC variables. Moreover, the relationship between SWRC and shrinkage curve has been investigated. A new method to determine total SWRC variables directly without curve-fitting procedure is proposed. Substituting the variables into linear SWRC equations construct SWRC. A good agreement was obtained between predicted and measured SWRCs, indicating the validity of the proposed method for unimodal SWRC.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.26 no.5
• /
• pp.851-859
• /
• 1997

This study was perfomed to investigate the contamination level of harmful heavy metals and the level of trace elements in 15 kinds of fish collected at the western coast in Korea from July to December in 1996. The levels of total lead, cadmium, mercury, iron, copper and zinc were determined and the results were summarized as follows: The minimum and maximum values(ppm) of fish, mean value bracketed, were ; Pb : 0.02~4.80(2.26), Cd: 0.001~0.54(0.04), Hg: 0.007~1.08(0.52), Fe: 7.76~66.39(25.70), Cu; 0.37~121.6(1.90), Zn:12.01~112.10(54.78). The results show that mean contents of Pb, Cd and Hg in 15 species fish were not yet dangerous levels enough to cause a health problem. But the contents of Pb and Hg tend to increase.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
• /
• 1989.10a
• /
• pp.9-12
• /
• 1989

ABSTRACT -- Recently, a method of magnetically-enhanced discharge columns is considered to increase the luminous efficacy of discharge lamps, which is based upon the face that the diffusion motion of charged particles in the discharge column strongly depends on the applied magnetic fields. This study investigates the effect of applied transverse magnetic fields on the light output of low-pressure Hg-Ar discharge. As a result, it is found that the electric field in the positive column increases according to the applied megnetic field, which causes an increase in the total light output. And this effect is much more pronounced upon the spectral line originating form the higher levels.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.20 no.6
• /
• pp.615-620
• /
• 1991

This study was performed to investigate the contamination level of harmful metals in 4 species of freshwater fishes collected at the three sampling sites of Yeong san river from January to October in 1990. The levels of total mercury, lead, zinc, manganese, copper and cadmium were ditermined and the results were summarized as follows : The overall range(ppm) were Hg, 0.022~0.139 ; Pb, 0.666~0.984 ; Zn, 8.673~15.214 ; Mn, 2.751~5.049 ; Cu, 0.328~1.174 ; Cd, 0.017~0.052. Among the six heavy metals contents, the highest was zinc and the lowest was cadmium. The results showed that all the 4 species of freshwater fishes of Yeong san river studied have not yet dangerous levels enough to pose a health problem.

• Korean Journal of Health Education and Promotion
• /
• v.21 no.3
• /
• pp.117-131
• /
• 2004

Purpose: This study was conducted to evaluate the health behaviors and to find out risk factors of blood pressure of adult women in a rural area. Method: The convenient sample consisted of 159 adult women who lived in G-gun. The data was collected using a self-report questionnaire for health behaviors and mercury type sphygmomanometer for BP, between Jun I and August 15, 2003. Health behaviors measured smoking, alcohol, salt, lipid, stress, exercise, coffee, BMI and medication. To accomplish the goal of study, descriptive statistics, t-test, $x^2$-test, ANOVA and multiple regression analysis were. performed with SPSS 10.0. Results: The average age of subjects was 49.2(SD7.34)years old. The average SBP and DBP of subjects were 126.22mmHg(SDl6.73) and 8 1.25mmHg(SDl 0.31). There were significant differences in smoking(p=.000), cigarette consumption(p=.001), smoking duration(p=.000), BMI(p=.033), medication (p=.001), family history(p=.000) between normotensive and hypertensive. The main risk factors on SBP were medication, age, BMI, family history and smoking duration by 35.7% of the total variance these variables explained SBP. The main risk factors on DBP were BMI, education and medication by 17.60% of the total variance these variables explained DBP. Conclusion: These results suggest that health professional have to emphasize prevention of obesity, lasting medication and no smoking for prevention and management of hypertension in community health promotion program.

• Fisheries and Aquatic Sciences
• /
• v.17 no.2
• /
• pp.197-201
• /
• 2014

This study was performed to identify and assess food hazards during dry laver processing. Samples including raw materials, intermediates, and finished products during dried-laver processing were collected from seven dried-laver processing facilities, and microbial analyses were conducted. Microbial levels such as total coliforms and total viable cell count (TVC) increased as the processing steps progressed. TVC and total coliforms ranged from <30 to $9.1{\times}10^7$ CFU/g and <18 to 27,600 MPN/100 g for intermediates and finished products obtained during dried-laver processing, respectively. However, no fecal coliform was detected in the samples. Additionally, food-borne bacteria including Bacillus cereus, Listeria monocytogenes, Salmonella sp., Staphylococcus aureus, and Vibrio parahaemolyticus were not identified in finished products. For heavy metal content, arsenic ranged from 30.18 to 39.05 mg/kg, mercury from 0.005 to 0.009 mg/kg, and cadmium from 0.076 to 0.318 mg/kg dry mass in all finished products. However, lead was not detected in samples tested in this study. In conclusion, dried-laver products were safe based on the levels of food-borne bacteria and heavy metal contents. However, it is important to reduce total viable cell counts and total coliforms during dried-laver processing.

• Journal of Food Hygiene and Safety
• /
• v.33 no.3
• /
• pp.168-175
• /
• 2018

The use of microwave-assisted extraction and an acid-base clean-up process to determine the amount of methylmercury (MeHg) in marine products was suggested in order to improve the complicated sample preparation process. The optimal conditions for microwave-assisted extraction was developed by using a 10% NaCl solution as an extraction solution, setting the extraction temperature at $50^{\circ}C$, and holding for 15 minutes to extract the MeHg in marine products. A NaOH solution was selected as a clean-up substitute instead of L-cysteine solution. Overall, 670 samples of marine products were analyzed for total mercury (Hg). Detection levels were in the range of $0.0006{\sim}0.3801{\mu}g/kg$. MeHg was analyzed and compared using the current food code and the proposed method for 49 samples which contained above 0.1 mg/kg of Hg. Detection ranges of methylmercury followed by the Korea Food Code and the proposed method were $75.25(ND{\sim}516.93){\mu}g/kg$ and $142.07(100.14{\sim}244.55){\mu}g/kg$, respectively. The total analytical time of proposed method was reduced by more than 25% compared with the current food code method.

• Journal of Food Hygiene and Safety
• /
• v.27 no.4
• /
• pp.349-355
• /
• 2012

In this study, we configured a system which ranks hazardous chemicals to determine their management priorities based on experts' opinions and the existing CRS (chemical ranking and scoring). Aggregate exposure of food, health functional food, oriental/herbal medicine and cosmetics have been taken into account to determine management priority. In this study, 25 hazardous chemicals were selected, such as cadmium, lead, mercury, and arsenic, etc. These 25 materials were ranked according to their 1) risk (exposure or hazard) indexes, 2) exposure source-based weight, and 3) public interests, which were also formed based on the existing priority ranking system. Cadmium was scored the highest (178.5) and bisphenol A the lowest (56.8). Ten materials -- cadmium, lead, mercury, arsenic, tar, acrylamide, benzopyrene, aluminium, benzene, and PAHs -- scored higher than 100. Eight materials -- aflatoxin, manganese, phthalate, chromium, nitrate/nitrite, ethylcarbamate, formaldehyde, and copper -- recorded scores in the range from 70 to 100. Also evaluated as potential risks were 7 materials; sulfur dioxide, ochratoxin, dioxins, PCBs, fumonisin, methyl mercury, and bisphenol A, and these materials were scored above 50. Then we compared risk index and correlation coefficient of total scores to confirm the validity of the total scores; we analyzed correlation coefficient of parameter and indicator. We discovered that the total score and weight, which has incorporated public interests, were high and statistically significant. In conclusion, the result of this study contributes to strengthening risk assessment and risk management of hazardous chemicals.