• Korean Journal of Ecology and Environment
• /
• v.45 no.3
• /
• pp.271-277
• /
• 2012

The present study was conducted to assess the suitability of domestic natural waters as a Daphnia magna culture medium. In order to assess survival rate and reproductive output, young female daphnids (parent animals), aged less than 24 hours at the start of the test and produced in the Elendt M4 medium, were exposed to Elendt M4 medium, de-chlorinated tap water, and natural mineral water for 21 days. D. magna cultured in Elendt M4 medium (reference medium) and natural mineral water met the criteria of OECD No. 211, Daphnia magna Reproduction Test Guidelines in terms of percent adult survival, first day of reproduction, and average young production. However, the mortalities of adult daphnids observed in de-chlorinated tap water were more than 20% in two reproduction tests for 21 days. Mortality was observed on exposure days 13, 15, and 18 in de-chlorinated water. The use of D. magna is recommended in water of hardness >80 mg $CaCO_3\;L^{-1}$. However, the hardness of de-chlorinated tap water used in the present study was 50~53 mg $CaCO_3\;L^{-1}$. Therefore, it is judged that the delayed mortalities observed in de-chlorinated tap water were caused by a rapid decreased in hardness when the medium was changed from Elendt M4 to de-chlorinated tap water. When D. magna is cultured using domestic natural waters (underground water, surface water, and de-chlorinated water), the quality-control (QC) data should be maintained through a standardization for health assessment method, toxicity test method using reference chemical, test intervals of reference toxicant toxicity test, and data treatment and interpretation. In the long term, national research programs are needed for the development of test species which are representative of domestic aquatic environmental conditions among indigenous daphnids.

• Journal of Korean Society of Environmental Engineers
• /
• v.30 no.4
• /
• pp.393-400
• /
• 2008

1,4-Dioxane($C_4H_8O_2$), which is used as a solvent stabilizer, could make harmful effects on ecosystem because of its higher solubility, toxicity and carcinogenic by US EPA. From 2011, its discharge limit to waterbody will be regulated at 5 mg/L by Ministry of Environment Republic of Korea. It was thus to investigate that the currently operating activated sludge in polyester manufacturing processes in Gumi can properly treat it to meet with the regulation standard. For that purpose, the removal rate of 1,4-dioxane and its microbial properties were assessed for a few companies(i.e. K, H and T). Its removal efficiency was the most highly recorded in H as 98% and then 77% for K, which met with the regulation standard. However, concentration of 1,4-dioxane of T was 23 mg/L in the effluent, which is more than the regulation standard. Aside from, microbial degradation test was done for 100 ppm of 1,4-dioxane in BSM (Basal salt medium) inoculated with each of activated sludge. After 7 days, 1,4-dioxane was completely removed in the test bottle inoculated with H sludge, 67% in T and 52% in K, which could confirm that the given activated sludge might have different biodegradability against the amount of 1,4-dioxane. Therefore, microbial diversity in each company was investigated by 16s rDNA cloning methods where a species, e.g. Methylibium petroleiphilum PM1, was the greatest observed from H and in lesser from K, but it was not detected from T. Methylibium petroleiphilum PM1 is known to efficiently degrade ether like methyl tertiary-butyl ether(MTBE). It is concluded that the activated sludge in H can be most effectively adopted for a biodegradation of 1,4-dioxane in the concern of industrial sector.

• Journal of Soil and Groundwater Environment
• /
• v.7 no.2
• /
• pp.63-71
• /
• 2002

The authors selected the modified soil method, and then performed the geotechnical and environmental laboratory test, and evaluated whether the modified soil liner could be accepted as a barrier layer in landfill. Unlike the results of the natural soil(CL), those of the hydraulic conductivity test of stabilized soil met the standard value. According to these results, the optimal mixing ratio of a mixture(cement : bentonite : stabilizing agent) was 90 : 60 : 1 with mass ratio(kg) for 1㎥ with soil, and it was possible to use poor quality bentonite. B\circled2 because of a little difference from results with high quality bentonite. B\circled1. The Cation Exchange Capacity(CEC) of the modified soil was increased about 1.5 times compared with the natural soil; however. the change of CEC with a sort of additives was not detected. In order to observe the change of the chemical components and crystal structures, the natural and the modified soils with the sorts of additives were measured by the XRF(X-Ray Flourescence Spectrometer) and SEM, but there was no significant change. The artificial leachate with the heavy meals ($Pb^{2+}$ , $Cu^{2+}$, $Cd^{2+}$ Zn$^{2+}$ 100mg/L) was passed through the natural soil and modified soils in columns. In the natural soil, Cd$^{2+}$ and $Zn^{2+}$ were identified, simultaneously the pH of outflow was lower, and then came to the breakthrough point. The removal efficiency of the natural soil was showed in order of following : $Pb^{2+}$ ≒$Cu^{2+}$ > $Zn^{2+}$ > $Cd^{2+}$ On the other hand, modified soils were not showed the breakthrough condition like the result of the natural soil. The modified soil with the lower quality bentonite, B\circled2(column3) was more stable with respect to chemical attack than that with the higher bentonite, B\circled1(column2) because the change range of outflow pH in columns was less than that of outflow pH in column2. In addition, the case of adding the stabilizing agent(column4) was markedly showed the phenomena.ena.

• Journal of the Korean Wood Science and Technology
• /
• v.48 no.3
• /
• pp.271-282
• /
• 2020

Sewage treatment plants are social infrastructure of cities. The sewage distribution rate in Korea is reaching 94% based on the sewage statistics based in the year of 2017. In Korean sewage treatment plants, use of PAC (Poly Aluminum Chloride) accounts for 58%. It contains a large amount of impurities (heavy metal) according to the quality standards, however, there have been insufficient efforts to reinforce the standards or technically improve the quality, which resulted in secondary pollution problems from injecting excessive coagulant. Also, the increase in the use of chemicals is leading to the increases in the annual amount of sewage sludge generated in 2017 and the need to reuse sludge. As such, this study aims to verify the possibility of reusing sludge by evaluating the stability of heavy metals based on the injection of coagulant mixture during water treatment which uses the torrefield wood powder and natural materials, and evaluating the sedimentation and heating value of sewage sludge. As a result of analyzing heavy metals (Cr, Fe, Zn, Cu, Cd, As, Pb, and Ni) from the coagulant mixture and PAC (10%), Cr, Cd, Pb, Ni, and Hg were not detected. As for Zn, while its concentration notified in the quality standards for drinking water is 3 mg/L, only a small amount of 0.007 mg/L was detected in the coagulant mixture. Maximum amounts of over double amounts of Fe, Cu, and As were found with PAC (10%) compared to the coagulant mixture. Also, an analysis of sludge sedimentation found that the coagulant mixture showed a better performance of up to double the speed of the conventional coagulant, PAC (10%). The dry-basis lower heating value of sewage sludge produced by injecting the coagulant mixture was 3,378 kcal/kg, while that of sewage sludge generated due to PAC (10%) was 3,171 kcal/kg; although both coagulants met the requirements to be used as auxiliary fuel at thermal power plants, the coagulant mixture developed in this study could secure heating values 200 kal/kg higher than the counterpart. Therefore, utilization of the coagulant mixture for water treatment rather than PAC (10%) is expected to be more environmentally stable and effective, as it helps generating sludge with better stability against heavy metals, having a faster sludge sedimentation, and higher heating value.

• Tuberculosis and Respiratory Diseases
• /
• v.63 no.6
• /
• pp.480-485
• /
• 2007

Background: Chronic obstructive pulmonary disease (COPD) is characterized by airflow limitation that is not fully reversible. COPD has systemic effects, such as skeletal muscle dysfunction and abnormal weight loss. It also has been suggested that COPD is related to other chronic disease, such as cardiovascular disease, osteoporosis, and anemia. The aim of this study was to evaluate a symptom questionnaire and laboratory findings in subjects with air flow limitation. Methods: We evaluated a symptom questionnaire and laboratory findings in subjects with airflow limitation detected by spirometry in conjunction with the Second Korean National Health and Nutrition Examination Survey. A total of 9,243 adults over the age of 18 were recruited. Among the adults, we finally analyzed 2,217 subjects who met the acceptability and repeatability criteria of spirometry, showed normal findings on chest radiography, and were older than 40 years of age. Results: There were 288 subjects with airflow limitation as determined by spirometry. The frequency of respiratory symptoms such as cough, sputum and wheezing were significantly higher in subjects with airflow limitation (p <0.01). Hemoglobin and hematocrit levels were higher in subjects with airflow limitation (hemoglobin level 13.98 mg/dL vs. 13.62 mg/dL, hematocrit 42.10% vs. 40.89%; p<0.01). The HDL cholesterol level was lower in subjects with airflow limitation (44.95 mg/dL vs. 45.60 mg/dL; p<0.01). There was no significant difference in the total cholesterol, triglyceride, blood urea nitrogen, creatinine, and fasting glucose levels. Conclusion: In subjects with airflow limitation, prevalence of respiratory symptoms was higher than in normal spirometry subjects and the levels of hemoglobin and the hematocrit were higher. The HDL cholesterol level was lower in subjects with airflow limitation.

• Journal of Sericultural and Entomological Science
• /
• v.46 no.2
• /
• pp.47-53
• /
• 2004

To reveal the possibility as a source of functional food and to increase the usability of mulberry fruits, amino acid analysis with mulberry fruits was carried out with L-8800 Amino acid auto analyzer. We analyzed 16 amino acid components including 6 essential amino acids. According to the results, the mean content of total amino acid was 4,640.8 mg/100 g DW. 'Sabangso(II)' showed the highest total amino acid content (6,919.3 mg/100 g DW) among the fifty accessions tested, whereas 'Gukkwang' showed the lowest content (3,389.1 mg/100 g DW). The distribution rate of amino acid components decreased in the order of Glu ($20.1\%$) > Gly ($12.7\%$) > Asp ($12.5\%$) > Thr ($8.2\%$) > Ala ($7.9\%$) > Arg ($7.5\%$) > Pro ($6.1\%$) > Ser ($6.1\%$) > Val ($5.7\%$) > Leu ($5.3\%$) > Ile ($2.7\%$) > His ($2.5\%$) > Met ($0.9\%$) > Tyr ($0.8\%$) > Lys ($0.7\%$) > Cys ($0.3\%$). 'Sabangso(II)' showed the highest content in 11 amino acid components, which were Glu (1,293.2 mg/100 g), Ser (390.2 mg/100 g), Thr (564.4 mg/100 g), His (175.3 mg/100 g), Arg (590.4 mg/100 g), Lys (53.5 mg/100 g), Gly (589.4 mg/100 g), Ala (499.3 mg/100 g), Leu (481.9 mg/100 g), Ile (240.9 mg/100 g), and Val (407.6 mg/100 g). Tyr and Cys were the highest in 'Jangsosang' (70.8 mg/100 g, 19.3 mg/100 g, respectively), and Asp, Pro, and Met were the highest in 'Jasan(I)', 'Hwansipchosaeng' and 'Palcheongsipyung(I)' (1,098.8 mg/100 g, 364.4 mg/100 g, 68.8 mg/100 g, respectively).

• Clinical and Experimental Pediatrics
• /
• v.45 no.6
• /
• pp.773-782
• /
• 2002

Purpose : To identify the necessity of more reasonable diagnostic criteria and the possibility of early prediction of coronary involvement in the higher risk group, we investigated and compared clinical and laboratory findings in the acute phase and coronary involvements in those younger (n=17) and older(n=53) than one year of age in Kawasaki disease(KD). Methods : Retrospective chart reviews were performed on 70 patients with KD who were admitted to the Chung-Ang University Hospital from April 1997 to May 2001. Results : Male were significantly higher in the younger age group(M : F ratio 3.3 : 1 vs. 1.0 : 1, P=0.004). Fever durations before intravenous immunoglobulin(IVIG) and echocardiography were significantly shorter in the younger group($4.6{\pm}1.3$ vs. $6.2{\pm}2.5$, P=0.004 vs. 0.01, respectively). Cases meeting typical diagnostic criteria were significantly less in the younger group(P=0.006). In the laboratory findings, serum albumin, BUN and $K^+$ levels in the acute febrile phase were significantly higher in the younger group(P=0.002, 0.006, <0.001, respectively) and incidences of coronary artery dilatation in the acute phase were significantly higher in the younger group(P=0.01). Conclusion : Although less met the typical diagnostic criteria of KD, infants younger than one year of age are more susceptible to coronary artery change in the acute febrile phase. Therefore, KD should be entertained as a diagnostic possibility in young infants with prolonged fever without distinct fever focus, and echocardiography should be considered as part of the evaluation of these patients, and then early diagnosis and prompt IVIG should be conducted.

• Clinical and Experimental Pediatrics
• /
• v.52 no.11
• /
• pp.1267-1272
• /
• 2009

Purpose:We examined the ability of preschool aged children to meet the American Thoracic Society (ATS) and European Resiratory Society (ERS) goals for spirometry quality and tried to find out the major factor for improving the rate of success of spiromety test in this age group. Methods:Spirometry was performed in 2-6 aged 155 children with chronic cough or suspicious asthma with the recording of maneuver quality measures of forced expiratory time, end-of-test volume, back-extrapolated volume (Vbe), and forced vital capacity (FVC), as well as flow-volume curve. The subjects were tested several times and the two best results in each subject were selected. All criteria for quality control were suggested by ATS/ERS guidelines. The criteria for starting of the test was Vbe <80 mL and Vbe/FVC <12.5%. The criteria for repeatability of the test was that second highest FVC and FEV1 are within 100 ml or 10% of the highest value, whichever is greater. For the criteria for termination of the test for preschool aged children, we evaluated the flow-volume curve Results:As getting older, the success rate of spirometry increased and rapidly increased after 3 years old. Total success rate of the test was 59.4% (2 years old - 14.3%, 3 years old - 53.7%, 4 years old - 65.1%, 5 years old - 69.7%, 6 years old- 70.8%). The percentage of failure to meet the criteria for starting the test was 6.5%, repeatability of the test was 12.3% and end of the test was 31%. There was a significant difference only in age between success group and failure group. Evaluating the quality control criteria of previous studies, the success rate increased with age. Conclusion:About 60% of preschool aged children met ATS/ERS goals for spirometry test performance and the success rate was highly correlated with age. It is clearly needed that developing more feasible and suitable criteria for quality control of spirometry test in preschool aged children.

• Korean Journal of Food Science and Technology
• /
• v.37 no.6
• /
• pp.898-904
• /
• 2005

Although Euonymus alatus (EA) has been used as traditional medicine for cancer treatment, exact substances involved in curing of the disease are not yet known. Free radical scavenging and reactive oxygen species (ROS) removal activities of aqueous extract components isolated from winged stem of EA in animal cell line were investigated. Aqueous extract of EA (AEEA) was fractionated by ultrafiltration. All fractions mainly consisted of polysaccharide (44.8%), protein (2.1%), small amounts of phenol compounds and organic acids. Antioxidant activity of AEEA increased depending on concentration fractions, as determined by 1,1-diphenyl-2-picrylhydrazyl method. ROS removal activity was visualized in Chinese hamster ovary cell line using laser scanning confocal microscope, and AEEA activity increased in order of F IV>F III>F I>F II. These results suggest AETA has bioactive carbohydrates with potentials as functional foods and antioxidants.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.59 no.4
• /
• pp.457-462
• /
• 2014

This study was conducted to evaluate basic seed characteristics such as morphological characteristics and various seed vigor using 4 sorghum varieties, Nampungchal, Donganme, Hwanggeumchal and Whinchal. No difference was shown in morphological characteristics of the varieties except that the width. Whinchal has bulb-shaped seed, while the other varieties have oval-shaped seeds. The seed coat color of Whinchal is obviously different from those of the other varieties; especially, Nampungchal and Hwanggeumchal are not glossy. Germination rate were Hwanggeumchal > Nampungchal > Donganme > Whinchal in the order of higher rate in standard germination tests and cold germination test. In the ageing test, Donganme showed the lowest 15% decrease in comparison with the standard cultivar. Electric conductivity (EC) has negative correlation with standard germination tests, cold germination test and accelerated ageing test. In the percentage of emergence (PE), Hwanggeumchal was the highest 85.7% which was more than 40% to the lowest Whinchal. Mean emergence time (MET) showed significant difference between the varieties; Whinchal showed the slowest 6.0 days.