• Korean Journal of Environmental Agriculture
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• v.15 no.2
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• pp.198-206
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• 1996

Leaching of $^{54}Mn$, $^{60}Co$, $^{85}Sr$ and $^{137}Cs$ in paddy soil was studied using lysimeter cultures in a greenhouse. The radionuclides were applied to the water surfaces shortly before transplanting and five different times between transplanting and harvest. Fertilizer KCl and slaked lime were added simultaneously in the rate of 83kg and 200kg, respectively, per l0a following the first application after transplanting. Percolating water was sampled until two days before harvest. Concentrations of the radionuclides in percolating water decreased in the order of $^{85}Sr$ > $^{54}Mn$ > $^{60}Co$ > $^{137}Cs$ on the whole. Time taken to reach the maximum was the shortest for $^{137}Cs$(< one week) and the longest for $^{54}Mn$ and $^{85}Sr$. Six days' water dropping started 47 days after transplanting reduced the concentrations of $^{54}Mn$, $^{60}Co$, $^{85}Sr$ and $^{137}Cs$ by factors of 30-180, 3-75, 2-4 and 3-6, respectively, depending on the application time. After the significant decrease, $^{54}Mn$ concentration tended to gradually increase but $^{137}Cs$ did to the contrary Percent leaching varied 0.09-6.2% for $^{54}Mn$, 0.009-0.9% for $^{60}Co$, 1.4-14.4% for $^{85}Sr$ and 0.002-0.06% for $^{137}Cs$, with the application time. The highest leaching came from the application at 40 days after transplanting for all the radionuclides. The addition of KCl and lime increased percent leaching of the radionuclides by factors of 9, 85, 4 and 9, respectively.

• Journal of Korea Soil Environment Society
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• v.4 no.1
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• pp.109-118
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• 1999

Recently, transport parameters of conservative solutes such as KCl in a porous medium have been successfully determined using time domain reflectometry (TDR) . This study was initiated to Investigate the applicability of TDR technique to monitoring the fate of a heavy metal ion in a sandy soil and the distribution of its concentration along travel distance with time. A column test was conducted in a laboratory that consists of monitoring both resident and flux concentrations of $ZnCl_2$in a sandy soil under a breakthrough condition. A tracer of $ZnCl_2$(10 g/L) was injected onto the top surface of the sample as pulse type as soon as a steady-state condition was achieved. Time-series measurements of resistance and electrical conductivity were performed at 10 cm and 20 cm of distances from the inlet boundary by horizontal-positioning of parallel TDR metallic rods and using an EC-meter for the effluent exiting the bottom boundary respectively. In addition. Zn ions of the effluent were analyzed by ICP-AES. Since the mode and position of concentration detected by TDR and effluent were different, comparison between ICP analysis and TDR-detected concentration was made by predicting flux concentration using CDE model accommodating a decay constant with the transport parameters obtained from the resident concentrations. The experimental results showed that the resident concentration resulted in earlier and higher peak than the flux concentration obtained by EC-meter, implying the homogeneity of the packed sandy soil. A close agreement was found between the predicted from the transport parameters obtained by TDR and the measured $ZnCl_2$concentration. This indicates that TDR technique can also be applied to monitoring heavy metal concentrations in the soil once that a decay constant is obtained for a given soil.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.1
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• pp.33-42
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• 2000

Adsorption onto the surfaces of solid particles is a well known phenomenon that causes the retardation effect of heavy metals in soils. For adequate remediation of soil and groundwater contamination, it is important to investigate the mobility of heavy metals that largely depends on pH conditions in the soil water since adsorption of heavy metals is pH-dependent. In this study, we investigated the transport of Zn ion under various pH conditions in a sandy soil by conducting batch and column tests. The batch test was performed using the standard procedure of equilibrating fine fractions collected from the soil with eleven different initial $ZnCl_2$ concentrations, and analysis of Zn ion in the equilibrated solutions using ICP-AES. The column test consisted of monitoring the concentrations of soil solutions exiting the soil column with time known as a breakthrough curve (BTC). We injected respectively $ZnCl_2$ and KCl solutions with the concentration of 10 g/L as a tracer in a square pulse type under three different pH conditions (7.7, 5.8, 4.1) and monitored the flux concentration at the exit boundary using an EC meter and ICP-AES. The resident concentration was also monitored at the 10cm-depth by Time Domain Reflectometry (TDR). The results of batch test showed that ion exchange process between Zn and other cations (Ca, Mg) was predominant. The retardation coefficients obtained from adsorption isotherms (Linear, Freundlich, Langmuir) resulted in the various values ranging from 1.2 to 614.1. No retardation effect but ion exchange was found for the BTCs under all pH conditions. This can be explained by the absence of other cations to desorb Zn ion from soil exchange sites under the conditions of ETC experiment imposing blank water as leachate in steady-state flow. As pH decreased, the peak concentration of Zn increased due to the competition of Zn with hydrogen ions ($H^+$) and the concentrations of other cations decreased. The peak concentration of Zn was increased by 12.7 times as pH decreased from 7.7 to 4.1.

• Journal of Mushroom
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• v.22 no.2
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• pp.60-66
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• 2024

This study was conducted to selection and investigate appropriate conditions for mass production of antagonistic microbes to control cobweb disease caused by Cladobotryum mycophilum. A grampositive bacterium was isolated from spent substrate of Agaricus bisporus and showed significant antagonistic activity against Cladobotryum mycophilum. The bacterium was identified as Bacillus altitudinis. based on the cultural, biochemical and physiological characteristics, and 16S rRNA sequence. The isolate is saprophytic, but not parasitic nor pathogenic to cultivated mushroom whereas it showed strong inhibitory effects against C. mycophilum cells in vitro. The control efficacy of B. altitudinis HC7 against cobweb disease of C. mycophilum was up to 78.2% on Agaricus bisporus. The suppressive bacterium may be useful for the development of biocontrol system. To define the appropriate conditions for the mass production of the Bacillus altitudinis HC7, we have investigated appropriate culture conditions and effects of various nutrient source on the bacterial growth. The appropriate initial pH and temperature were determined as pH 6.0 and 30℃, respectively. The appropriate concentration of medium elements for the growth of pathogen inhibitor bacterium(Bacillus altitudinis HC7) was determined as follows: 3.0% soluble startch, 10% soytone, 1.0% (NH₄)₂HPO₄, 1.0 mmol KCl, and 0.5% L-asparagine.

• Economic and Environmental Geology
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• v.36 no.2
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• pp.75-87
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• 2003

The Haman-Gunbuk mineralized area is located within the Cretaceous Gyeongsang Basin along the southeastern part of the Korean peninsula. Major ore minerals, magnetite, scheelite, molybdenite and chalcopyrite, together with base-metal sulfides and minor sulfosalts, occur in fissure-filling tourmaline, quartz and carbonates veins contained within Cretaceous sedimentary and volcanic rocks anu/or granodiorite (118{\pm}$3.0 Ma). The ore and gangue mineral paragenesis can be divided into three distinct stages: Stage 1, tourmaline+quartz+Fe-Cu ore mineralization; Stage II, quartz+sulfides+sulfosalts+carbonates; Stage 111, barren calcite. Earliest fluids are recorded in stage I and early por-tions of stage II veins as hypersaline (35~70 equiv. wt.% NaCl+KCl) and vapor-rich inclusions which homogenize from ~30$0^{\circ}C$ to $\geq$50$0^{\circ}C$. The high-salinity fluids are complex chloride brines with significant concentrations of sodium, potassium, iron, copper, and sulfur, though sulfide minerals are not associated with the early mineral assemblage produced by this fluid. Later solutions circulated through newly formed fractures and reopened veins, and are recorded as lower-salinity(less than ~20 equiv. wt.% NaCl) fluid inclusions which homogenize primarily from ~200 to 40$0^{\circ}C$. The oxygen and hydrogen isotopic compositions of fluid in the Haman-Gunbuk hydrothermal system represents a progressive shift from magmatic-hydrothermal dominance during early mineralization stage toward meteoric-hydrothermal dominance during late mineralization stage. The earliest hydrothermal fiuids to circu-late within the granodiorite stock localiring the ore body at Haman-Gunbuk could have exsolved from the crystal-lizing magma and unmixed into hypersaline liquid and $H_2O$-NaCl vapor. As these magmatic fluids moved throughfractures, tourmaline and early Fe, W, Mo, Cu ore mineralization occurred without concomitant deposition of othersulfides and sulfosalts. Later solutions of dominantly meteoric origin progressively formed hypogene copper and base-metal sulfides, and sulfosalt mineralization.

• The Korean Journal of Pharmacology
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• v.30 no.1
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• pp.87-100
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• 1994

It has been known for some time that dopamine-containing cells are existed in sympathetic ganglia, i.e., small, intensely fluorescent cells. However, its role and mechanism of action as a peripheral neurotransmitter are poorly understood so far. In the present study, an attempt was made to examine the effect of apomorphine, which is known to be a selective agonist of dopaminergic $D_2$. receptor on secretion of catecholamines (CA) from the isolated perfused rat adrenal gland. The perfusion of a low concentration of 10uM apomorphine into an adrenal vein for 20 min produced significant reduction in CA secretion induced by 5.32 mM ACh, 56 mM KCl, 100 uM DMPP and 100 uM McN-A-343. Increasing apomorphine concentration to 30 uM led to more markedly decreased CA secretion as compared to the case of 10 uM apomorphine and also did inhibit clearly CA release by $10^{-5}M$ Bay-K-8644. Furthermore, in adrenal glands preloaded with a higher dose of 100 uM apomorphine, CA releases evoked by ACh, excess $K^+$, DMPP and McN-A-343 were almost abolished by the drug. The perfusion of $3.3{\pm}10^{-5}M$ metoclopramide, which is well-known as a selective dopaminergic $D_2$ antagonist, produced significantly inhibitory effect of CA release by ACh, DMPP and McN-A-343 but did not affect that by excess $K^+$. However, preloading of 30uM apomorphine in the presence of metoclopramide did not modify the CA secretory effect of excess $K+$ and DMPP. These experimental results demonstrate that apomorphine causes dose-dependent inhibition of CA secretion by cholinergic receptor stimulation and also by membrane depolarization from the isolated perfused rat adrenal gland, suggesting that these effects appear to be exerted by inhibiting influx of extracellular calcium into the rat adrenal medullary chromaffin cells through activation of inhibitory dopaminergic receptors.

• Journal of the Korean Applied Science and Technology
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• v.33 no.3
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• pp.411-420
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• 2016

The objective of this study was to determine the effect of drinking water containing trimethyl glycine or ascorbic acid on growth performance and blood parameter profiles of duck exposed to scorching heat stress. A total of 480 ducks were randomly assigned to the following eight experiment groups for 42 days : control group C with general water, treatment group 1 (T1) with drinking water containing 100 ppm ascorbic acid, treatment group 2 (T2) with drinking water containing 200 ppm ascorbic acid, treatment group 3 (T3) with drinking water containing 300 ppm ascorbic acid, treatment group 4 (T4) with drinking water containing 400 ppm trimethyl glycine, treatment group 5 (T5) with drinking water containing 800 ppm trimethyl glycine, treatment group 6 (T6) with drinking water containing 1,200 ppm trimethyl glycine, treatment group 7 (T7) with electrolytes of KCl (0.5%) + $NaHCO_3$ (1.0%)+NaCl (0.5%). Our results revealed that the body weights and feed intakes of treatment groups, especially T3 and T6, were increased compared to the control group, where as the feed conversion ratios of treatment groups were decreased (p<0.05). Blood levels of total cholesterol, triglyceride, LDL-C, glucose, AST, ALT and pH in treatment groups were lower compared to those in the control group (p<0.05). Blood levels of red blood cell, platelets profiles, electrolyte and gas in treatment groups were higher compared to those of the control group (p<0.05).

• Maxillofacial Plastic and Reconstructive Surgery
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• v.11 no.1
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• pp.203-220
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• 1989

Ever since the expression of new tumor-specific antigens was reported during malignant transformation, studies on separation, purification and characterization of these proteins have been so activated recently. Following experiment was performed to observe tumor-specific antigens by implanting DMBA pellet into submaxillary gland of rat for inducing salivary gland tumor. After dividing 280 rats into 2 groups, in control group, sham operation was performed on right submaxillary gland and, in experimental group, DMBA pellet (5mg) was implanted into right submaxillary gland. Then proteins from excised submaxillary gland by killing 10 rats every two weeks for 28 weeks were extracted with 3M KCl, and SDS-PAGE and PAS-staining were carried out for biochemical examination. The obtained results were summarized as follows; 1) At 12th week since implantation of DMBA pellet, tumor mass formation was inspected. And dysplasia at 6th week and invasive epidermoid carcinoma at 10th week were observed by microscope. 2) In control group, the weight ratio of both submaxillary glands had no any change, however, in experimental group, the ratio was increased remarkably. And at 28th week after DMBA implantation, there was more than 15 times of differences in weight between control and experimental group. 3) There was no DMBA remnant after 22nd experimental week. 4) In the SDS-PAGE, high molecular protein bands (more than 100 kd) were appeared much, and new prominent protein bands (66, 48, 41.5, 39, 37, 37.5 kd) were appeared after 4th week since DMBA implantation. However, 38, 27, 22kd protein bands were disappeared. 5) In PAS-staining, high molecular proteins were proteins were all glycoproteins and 37.5kd protein was proved as to be glycoprotein. And 38kd glycoprotein was disappeared after 4th week since DMBA implantation.

• The Korean Journal of Mycology
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• v.27 no.6 s.93
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• pp.399-405
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• 1999

Intergeneric hybrids between Saccharomyccopsis fiburigera KCTC 7393 and Saccharomyces cerevisiae KCTC 7049 (tyr-, ura-) were obtained by nuclear transfer technique. Nuclei isolated from the wild type S. fiburigera strain were transfered into auxotrophic S. cerevisiae mutants and new strains showing an increased starch degrading capability were selected. Maximum production of protoplasts was obtained from the treatment with 0.1 % Novozym 234 at $30^{\circ}C$ for 90 min, and most effective osmotic stabilizer for the isolation of protoplasts was 0.6 M KCl at pH 5.8. The frequency of protoplast regeneration was 14.64% under the conditions. Genectic stability, conidial size, DNA content, and nuclear stain suggested that the fusants were aneuploidy. The specific activity of ${\alpha}-amylase$ was observed to increase about $1.2{\sim}1.9$ folds.

• Environmental Analysis Health and Toxicology
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• v.25 no.1
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• pp.11-18
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• 2010

Toxicity assessment of ocean dumping wastes (dye waste, urban sewage, food waste) were examined in the fertilization and embryo development rates of the Sea Urchin, Hemicentrotus pulcherrimus. Spawning was induced by injecting 1 mL of 0.5 M KCl into coelomic cavity. Males released white or cream-colored sperms and females released yellow or orange-colored eggs. Experiments were began within 30 min the collection of both gametes. The fertilization and embryo development rates test were performed for 10 min and 64 h after fertilization, respectively. The fertilization and embryo development rates in the control condition (not including ocean dumping wastes sludge elutriate) were greater than 90%, but suddenly decreased with increasing of ocean dumping waste sludge elutriate concentrations. The fertilization and normal embryogenesis rates were significantly inhibited in all waste sludge elutriate from dye waste ($EC_{50}$=4.37; $EC_{50}$=1.76), urban sewage ($EC_{50}$=5.79; $EC_{50}$=2.00) and food waste ($EC_{50}$=7.68; $EC_{50}$=2.16), respectively. The NOEC (<3.13) and LOEC (3.13) of fertiliztion and normal embryogenesis rates very similar in all waste sludge elutriate. These results suggest that biological assay using the fertilization and embryo development rates of H. pulcherrimus are very useful test method for the ecological toxicity assessment of ocean dumping wastes.