• Journal of The Korean Society of Grassland and Forage Science
• /
• v.6 no.2
• /
• pp.71-77
• /
• 1986

The field experiment was conducted to evaluate the effect of herbicide treatment (Banvel: 100, 200, U-46: 150, 300, Hedonal: 150, 300, Simazin: 100, 200g/10 a) on change in the botanical composition and dry matter productivity of ladino clover (Trifolium repens L.) dominated pasture mixtures. The experiment was laid down as a randomized block design with 4 replications at experimental field of Livestock Experiment Station in Suweon from 1983 to 1985. The results obtained are summarized as follows: 1. Against ladino clover in mixie grass-clover swards Banvel, U-46 and Hedonal gave good control. The percentage of ladino clover under herbicide tratment decreased to about 1-2%(Banvel), 11-18%(U-46) and 22-31%(Hedonal), respectively, while it increased to 71% in untreated pastures. However, in the second year this trend stated to reverse and occurred clover dominance again in U-46 and Hedonal application, while those remained approximately constant until end of the years under Banvel treatment. Simazin is to be not recommended. 2. The best time for herbicide treatment was found to be late summer before autumn sown 20-25 days. When it applied in early summer weed infestigation by Digitaria spp., Echinochloa spp. and other species was a severe problem. 3. Emergence and early development of introduced pastures were less satisfactory, if it oversown immediatley after herbicide treatments due to its phytotoxical damage. Residual chemicals remained about 7-10 days in topsoils. Perennial ryegrass and orchardgrass were slightly less tolerant than the other species. 4. In dry matter, taken as average of three year results, Banvel applied pastures produced the remarkably high yield of 1023 kg/10 a, which is as much as 44% higher than that of untreated plot. Dry matter yields under U-46 and Hedonal treatment were 842 and 811 kg/10 a, respectively. 5. Weender components and net energy concentration were affected by change in the botanical composition. Crude protein and NEL value were slightly higher in clover dominance than those in herbicide treatments. Total yields of net energy lactation, however, were the highest in Banvel application with 5401 MJ and the lowest in untreatment with 3889 MJ-NEL/10 a DM.

• Economic and Environmental Geology
• /
• v.38 no.2 s.171
• /
• pp.101-111
• /
• 2005

The objectives of this study we to assess the extent and degree of environmental contamination and to draw general conclusions on the fate of toxic elements derived from mining activities in Korea. 인t abandoned mines with four base-metal mines and four Au-Ag mines were selected and the results of environmental surveys in those areas were discussed. In the base-metal mining areas, the Sambo Pb-Zn-barite, the Shinyemi Pb-Zn-Fe, the Geodo Cu-Fe and the Shiheung Cu-Pb-Zn mine, significant levels of Cd, Cu, Pb and Zn were found in mine dump soils developed over mine waste materials, tailings and slag. Furthermore, agricultural soils, stream sediments and stream water near the mines were severely contaminated by the metals mainly due to the continuing dispersion downstream and downslope from the sites, which was controlled by the feature of geography, prevailing wind directions and the distance from the mine. In e Au-Ag mining areas, the Kubong, the Samkwang, the Keumwang and the Kilkok mines, elevated levels of As, Cd, Cu, Pb and Zn were found in tailings and mine dump soils. These levels may have caused increased concentrations of those elements in stream sediments and waters due to direct dis-charge downstream from tailings and mine dumps. In the Au-Ag mines, As would be the most characteristic contaminant in the nearby environment. Arsenic and heavy metals were found to be mainly associated with sulfide gangue minerals, and mobility of these metals would be enhanced by the effect of oxidation. According to sequential extraction of metals in soils, most heavy metals were identified as non-residual chemical forms, and those are very susceptible to the change of ambient conditions of a nearby environment. As application of pollution index (PI), giving data on multi-element contamination in soils, over 1.0 value of the PI was found in soils sampled at and around the mining areas.

• Korean Journal of Soil Science and Fertilizer
• /
• v.16 no.2
• /
• pp.131-155
• /
• 1983

Though it has been widely known the nitrogen effects are influenced by soils, varieties, and mineral nutrients in the rice culture, few analyses in relation to the factors increasing nitrogen effect have been studied in Korea. The effects of potassium and silica on the factors increasing nitrogen effects in paddy soils were investigated in accordance with soil improvement practices and nitrogen application methods for the cultivated varieties. The results obtained are as follows. 1. For 413 paddy fields, the yield from soils without nitrogen application ranged from 200 to 850kg/10a and that from nitrogen application did 350 to 1,051kg/10a. The yield increament by nitrogen application varied 50 to 650kg/10a depending on soils. 2. Soil chemical characteristics for high yield were different between with nitrogen and without nitrogen application. In the without nitrogen application, however, contents of organic matter, phosphorous, potassium and calcium of high yield soils were lower than those of low yield, while the available silica content was higher in the former. 3. The yield increased with nitrogen application up to 22.4kg/10a and thereafter it decreased. These phenomena were supposed to be not be decrease of nitrogen uptake but by lowered silica uptake. 4. Clay soil incorporation, deep plough, and inorganic constituents control such as Ca, Mg, and $Sio_2$ were effective as soil improvement praitices. It was appeared that increases of silica content and Ca/Mg ratio were important to increase nitrogen effects. 5. For the correlation between yield and yield components, it was high between yield and panicle in low nitrogen level and so was it between grain yield and ripening rate in high nitrogen. 6. In the urea and super granule urea application plot, recovery rate of nitrogen by plant and soil was high and yield was remarkable high. 7. Regardless of fertilizer types such as ammonium sulfate and urea, the residual nitrogen was about 4kg/10a in both plots of 5.8 and 11.6kg/10a. N applied. 8. The potassium application to soil enhanced the nitrogen efficiency. It was more effective in low potassium soil. 9. Optimum pH value for gel formation in the 4% sodium silicate solution was approximately 6.6. 10. It was suggested that silica could affect to rice plant growth as the inorganic and organic chemical components.

• Korean Journal of Soil Science and Fertilizer
• /
• v.24 no.3
• /
• pp.219-224
• /
• 1991

An acid tolerant R. meliloti "YA03" which was characterized through both acidified tube and pot soil experiment, was examined on its inoculation effect to alfalfa[Medicago sativa (L.)]cv. Vernal on hilly acid soil. It was conducted for 2 years to evaluate inoculation residual effect and there were two-fertilizer factors of nitrogen(0.8kg/10a) and lime(0,162kg/10a)as urea and $Ca(OH)_2$, respectively. The results obtained were summarized as follows : 1. In the 1st-year experiment, YA03 inoculated without nitrogen and lime application showed higher symbiotic effectiveness than check strains, YA026 and Rm2011 in nodule mass, $N_2$-fixing activity, and dry matter yield, but with N 8kg/10a application lower effectiveness than Rm2011. 2. In the 2nd-year experiment, Alfalfa dry matter yield by YA03 inoculation with N application(without lime) was 74% higher than that(276 kg/10a) in the 1st year, and the value showed 166%, 20%, and 21% increments as compared with noninoculated control(180kg/10a). YA026(399kg/10a), and Rm2011(397kg/10a), respectively. 3. In the 2nd-year experiment of N applicated plote(without lime), especially, YA03 showed higher shoot nitrogen(7.7kg N/10a/Yr.) fixed and soil rhizobial population($1{\times}10^4\;cells/g.\;soil$) than check strains. 4. On the basis of lime application, application effect of three major fertilizers with YA03 inoculation on alfalfa yield and soil rhizobial population was in the order of $N+P_2O_5+K_2O>P_2O_5+K_2O>P_2O_5+K_2O$. 5. On the whole, alfalfa yield by acid tolerant R. meliloti YA03 inoculation on hilly acid soil was enhanced with nitrogen application, and besides it appeared 44% higher with lime than without lime.

• Korean Journal of Food Science and Technology
• /
• v.30 no.2
• /
• pp.288-292
• /
• 1998

Thermooxidative stabilities of soybean oil, beef tallow and palm oil were studied during frying of steamed noodles. Steamed noodles were fried in $150^{\circ}C$ oils for 70 sec at the interval of 30 min. The frying oil was taken every 8 hrs for the analysis of peroxide value (PV) and free fatty acid (FFA) content, fatty acid composition, and tocopherol and tocotrienol content. A little change was shown in PV and FFA content in soybean oil during frying; on the other hand, rapid increase in beef tallow and palm oil was observed. Unsaturated fatty acid content was the highest in soybean oil, followed by palm oil and beef tallow. While fatty acid composition in soybean oil was not changed during frying, unsaturated fatty acid content decreased and saturated fatty acid increased in beef tallow and palm oil, which showed susceptibility to the oxidation. The ratio of linoleic acid to palmitic acid did not show difference with frying time in soybean oil: however, it decreased in other oils with a high correlation with frying time and higher decreasing rate in palm oil was observed. These suggested that soybean oil was the most stable to thermooxidation and the stability was followed by beef tallow and palm oil. Tocopherol was disappeared during frying and 87.5, 81.1, and 73.1% were remained in soybean oil after 8, 16 and 24 hour frying, respectively. Also the rate decreased in the order of ${\gamma}-,\;{\beta}-\;and\;{\alpha}-tocopherol$. However, 34.2 and 169.0 ppm tocopherol and tocotrienol which were present in control samples of beef tallow and palm oil were completely disappeared by 8 hr frying. Therefore, high thermooxidative stability of soybean oil resulted from higher residual amount of tocopherol during frying, and lower stability of palm oil than beef tallow was partly due to high degree of unsaturation.

• Journal of Korean Society of Environmental Engineers
• /
• v.32 no.12
• /
• pp.1087-1093
• /
• 2010

Autotrophic denitrification is known as an effective and economical alternative for heterotrophic denitrification using external carbon sources such as methanol. In this study, we evaluated design and operation parameters for a sulfur denitrification reactor (SDR) treating high strength nitrogen wastewater. The SDR was filled with spherical sulfur media in connected to a pilot-scale nutrient removal process (daily flow rate, $Q=18\;m^3/d$) using moving spongy media. Total nitrogen (TN) concentration of the final effluent was below the 7.0 mg TN/L because nitrate was additionally removed through autotrophic denitrificationin without adding alkalinity (initial alkalinity was $169.4{\pm}20.8\;mg$ $CaCO_3$/L). During the test period, 60~80% of nitrogen in the influent was removed even in low temperature (below $15^{\circ}C$). The alkalinity consumption for nitrate removal in SDR was $4.09{\pm}1.29$ g $CaCO_3/g$ ${NO_3}^-$-N, and the residual alkalinity of influent of SDR was higher than that of theoretical requirements for full conversion of nitrate. The consumption of sulfur was 943.8 g S/d and it was 2.4 times higher than theoretical value (400.1 g S/d) due to abrasion and loss of sulfur media in backwash, etc.

• Tuberculosis and Respiratory Diseases
• /
• v.40 no.3
• /
• pp.250-258
• /
• 1993

Background: After general anesthesia, decrease of functional residual capacity and lung compliance, ventilation/perfusion imbalance, and transpulmonary shunting can provoke hypoxemia during postoperative periods. Diaphragmatic dysfunction may be the main cause of these physiological abnormalities. Thus, we evaluated the change of pulmonary function after general anesthesia according to the operative sites, which could suggest clinical course and critical period of respiratory care of postoperative patients. Method: Preoperative portable spirometric evaluation and arterial blood gas analysis were performed at sitting or most-sitting position just previous day of surgery. Pulmonary function tests were also as same condition from postoperative day 1 to day 5. Results: 1) For thoracic surgery, FEV1 and FVC were not recovered at day 5, but FEV1/FVC was not decreased. $PaCO_2$ was slightly elevated at postoperative one day. 2) After upper abdominal surgery, postoperative day 5 did not show the recovery of FEV1 and FVC, but mild hypoxemia was developed at postoperative day 1. 3) Pulmonary function was recovered as preoperative value at postoperative day 5 in lower abdominal operation, but mild hypoxemia was also noted at postoperative day 1. 4) Surgery of peripheral areas did not show significant pulmonary function change and hypoxemia and hypercapnia from postoperative day 1. Conclusion: Surgery involving diaphragm provoke significant postoperative pulmonary function change after day 5. For the operation of peripheral sites adequate respiratory care during operation and postoperative period within 24 hours could prevent patients from respiratory complication.

• Journal of Chest Surgery
• /
• v.35 no.5
• /
• pp.350-355
• /
• 2002

Background: Most of pulmonary regurgitation with or without stenosis appears to be well tolerated early after the repair of pulmonary outflow tract. However, it may result in symptomatic right ventricular dilatation, dysfunction and arrhythmias over a long period of time. We studied the early outcome of pulmonary valve replacement with tissue valves for patients with the above clinical features. Material and Method: Sixteen consecutive patients who underwent pulmonary valve replacement from September 1999 to February 2002 were reviewed(9 males and 7 females). The initial diagnoses included tetralogy of Fallot(n=11), and other congenital heart anomalies with pulmonary outflow obstruction(n=5). Carpentier-Edwards PERIMOUNT Pericardial Bioprostheses and Hancock porcine valves were used. The posterior two thirds of the bioprosthetic rim was placed on the native pulmonary valve annulus and the anterior one third was covered with a bovine pericardial patch. Preoperative pulmonary regurgitation was greater than moderate degree in 13 patients. Three patients had severe pulmonary stenosis. Tricuspid regurgitation was present in 12 patients. Result: Follow-up was complete with a mean duration of 15.8 $\pm$ 8.5months. There was no operative mortality. Cardiothoracic ratio was decreased from 66.0 $\pm$ 6.5% to 57.6 $\pm$ 4.5%(n=16, p=0.001). All patients remained in NYHA class I at the most recent follow-up (n=16, p=0.016). Pulmonary regurgitation was mild or absent in all patients. Tricuspid regurgitation was less than trivial in all patients. Conclusion: In this study we demonstrated that early pulmonary valve replacement for the residual pulmonary regurgitation with or without right ventricular dysfunction was a reasonal option. This technique led to reduce the heart size, decrease pulmonary regurgitation and tricuspid regurgitation as well as to improve the patients'functional status. However, a long term outcome should be cautiously investigated.

• The Korean Journal of Nuclear Medicine
• /
• v.3 no.1
• /
• pp.51-58
• /
• 1969

To clarify the hematologic effects of the radioiodine ($^{131}I$) in therapeutic doses ($5{\sim}10$ mCi) on the various thyroid patients, authors studied the peripheral blood pictures of 396 goitrous patients before and after radioiodine ($^{131}I$) administrations in the Isotope Clinic of Seoul National University Hospital. Among these 396 cases of goiters, we gave 5 to 10 mCi of radioiodine ($^{131}I$) with single or fractionated administrations. The blood pictures of peripheral blood were repeated after 3 months in 40 cases of 65 cases who had been treated with $^{131}I$. The blood pictures of non-treated thyroid patients were compared with that of normal Korean values to clarify any difference between normal and goiter. The blood pictures of hyperthyroid patients treated with $^{131}I$ therapy were compared with the blood pictures of non-treated thyroid patients. The results were as following: 1) The incidence according to type: Toxic diffuse goiter: 35.4% Nontoxic nodular goiter: 29.7% Euthyroid: 13.8% Nontoxic diffuse goiter: 12.6% Hypothyroidism: 4.3% Thyroiditis($\bar{s}$ subacute form): 1.8% Toxic nodular goiter: 1.4% Malignancy: 1.0% 2) Age incidence: The range of distribution was 11 to 71 years. The peak incidence was found in the 4th decade of life. $80.6{\sim}82.6%$ of those 396 cases were found among the 3rd, 4th and the 5th decades of life. 3) Sex incidence: Sex ratio of male:female was 1:7.8. 4) The most outstanding findings in peripheral blood before treatment were decreased erythrocyte count and hemoglobin value in all types of thyroid diseases, especially in. the cases of hypothyroidism and thyroiditis. Hook worm-infested patients showed no significant difference in erythrocytes and hemoglobin values from those of other hook worm free patients. 5) Total leukocytes count was within normal range. Differential count of W.B.C. showed increased percentile of lymphocyte in diffuse toxic goiter and thyroiditis. 6) 39 cases of diffuse goiter treated with $^{131}I$ toxic showed amelioration in the anemia and restoration to normal range of lymphocyte count in association with increased percentile of neutrophiles 3 months after administration, except a case of toxic nodular goiter. One can observe anemia in slight degree, and increased lymphocytes count in hypothyroidism. Therapeutic dose of radioiodine ($^{131}I$) does not result any residual effect on the hematopoietic function. Radioiodine ($^{131}I$) therapy resulted in improvement of thyroid function in association of amelioration of pevious abnormal blood pictures. 7) Authors did not observe any myxedema resulted from radioiodine therapy during the 3 months period in this study.

• Journal of the Korean Society of Radiology
• /
• v.10 no.8
• /
• pp.619-627
• /
• 2016

The purpose of this study is to investigate the effect of CT contrast agent and MRI contrast agent on the area dose in the body when using automatic exposure control system in general radiography. After making rectangular holes in the center of the abdominal thickness paraffin phantom, CT contrast agent and MRI contrast agent were respectively diluted with physiological saline solution for contrast medium dilution ratio of 10:0, 9:1, 8:2, 7:3, 6:4, 5:5, 4:6, 3:7, 2:8, 1:9, 0:10%. Each experiment was set to 78 kVp, 320 mA, which is the proper condition for KUB photography, and thereafter a total of 30 inspections were made for each dilution ratio using an automatic exposure control device, and the area dose corresponding to the dilution ratio of each contrast agent, Average comparison and correlation analysis were performed on the exposure index. As a result, the CT contrast agent and the MRI contrast agent appeared different in area dose according to the dilution ratio(p<0.05), and as the dilution ratio increased, the area dose increased for CT contrast agent and MRI contrast agent(P<0.05). In each test, the exposure index showed the manufacturer's recommendation of 200-800 EI value, and the exposure index and area dose increased as the area dose increased(p<0.05). In conclusion, CT contrast agent and MRI contrast agent confirmed to increase the area dose by general imaging test using all automatic exposure control device. Therefore, it is considered that it is necessary to perform it after the contrast medium has been excreted sufficiently when using usual imaging test after using the contrast agent in CT and MRI examination.