• Journal of Korean Society of Environmental Engineers
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• v.22 no.1
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• pp.83-89
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• 2000

Bentonite has been considered as a liner material to restrict the release of hazardous heavy metals from the landfill. The adsorption of copper onto a domestic bentonite was studied to provide the adsorption isotherm and the effect of solution chemistry and temperature. The copper adsorption was fitted well to a Freundlich isotherm, in which Freundlich constants and correlation coefficient were calculated to be $K_F=1.18$, n=1.65, and $r^2=0.97$, respectively. The distribution coefficients ($K_d$) for the adsorption of copper decreased with increasing initial copper concentration. The $K_d$ increased with increasing the pH of solution, and drastically increased at pH > 5.3 because of precipitation of most copper species. As the ion strength of $Na^+$ in solution increased the $K_d$ decreased, while it increased with increasing the concentration of $SO_4{^{2-}}$ in solution. An increase in the temperature of experimental solution decreased the $K_d$ values.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.16 no.5
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• pp.217-222
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• 2023

The purpose of this paper was to synthesize a polymer organic hard mask that simplifies the manufacturing process, reduces process time significantly, and thereby lowers manufacturing costs. The results of measuring residual metals through vapor refining showed that 9-Naphthalen-1-ylcarbazole(9-NC) measured 101.75ppb in the 4th zone, 2-Naphthol (2-NA) measured 306.98ppb in the 5th zone, and 9-Fluorenone(9-F) measured between 129.05ppb across the 4th and 5th zones. After passing through a filtration system, the synthesized organic hard mask measured residual metals in the range of 9 to 7ppb. Additionally, the thermal analysis indicated a decrease of 2.78%, a molecular weight of 942, carbon content of 89.74%, and a yield of 72.4%. The etching rate was measured at an average of 18.22Å/s, and the coating thickness deviation was averaged at 1.19. For particle sizes below 0.2㎛ in the organic hard mask, no particles were observed. By varying the coating speed at 1,000, 1,500, and 1,800rpm and measuring the resulting coating thickness, the shrinkage rate ranged from 17.9% to 20.8%. The coating results demonstrated excellent adhesion to SiON, and it was evident that the organic hard mask was uniformly applied.

• The Korean Journal of Mycology
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• v.18 no.3
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• pp.164-177
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• 1990

This study was carried out to obtain some useful data for increasing an effective ginseng production. There was a direct relationship (r=0.2645) between spore germination of Fusarium solani and soil pH, and (r=0.315) between Cylindrocarpon destructans and soil pH. On the other hand, there was a direct relationship (r=0.19) between relative hyphal growth of Rhizoctonia solani and soil pH. There was a direct relationship (r=0.21) between number of total bacteria and F. solani, (r=0.37) between actinomycetes and F. solani and (r=0.20) between celluloytic bacteria and F. solani. However, there was an inverse relationship (r=-0.20) between number of total fungi and F. solani. There was a direct relationship (r=0.24) between number of actinomycetes and R. solani. Each ginseng pathogen-suppressive soil screened was 40 in F. solani, 20 in C. destructans and 9 soil samples in R. solani among 146 soil samples, respectively. The mean contents of K, Ca and Mg were fairly lower in each ginseng pathogen-suppressive soil than conducive soil, whereas Na were somewhat lower. The mean contents of organic matter were over 2 times higher in each ginseng pathogen-suppressive soil than conducive soil. The mean contents of phosphate were fairly lower in F. solani and R. solani-suppressive soil than conducive soil and, on the other hand, were somewhat higher in C. destructans-suppressive soil than conducive soil. The mean soil pH was somewhat lower in each ginseng pathogen-suppressive soil than conducive soil. The mean contents of sand were about 2 times higher in each ginseng pathogen­suppressive soil than conducive soil, whereas silt and clay were somewhat lower. The microbial numbers of total bacteria, total fungi and celluloytic fungi were higher in F. solani-suppressive soil than conducive soil, whereas actinomycetes and celluloytic bacteria were lower. Each microbial number of total bacteria or total fungi indicated a significant difference (p=0.05) between F. solani­suppressive and conducive soil, and the microbial number of actinomycetes was a highly significant difference (p=0.01) between F. solani-suppressive and conducive soil. The microbial numbers of total bacteria, total fungi, actinomycetes and celluloytic fungi were higher in C. destructans-suppressive soil than conducive soil, whereas celluloytic bacteria were about 2 times lower. On the other hand, the microbial numbers of total fungi were higher in R. solani-suppressive soil than conducive soil, whereas total bacteria, actinomycetes, celluloytic bacteria and celluloytic fungi were lower. Fourteen of 16 F. solani-suppressive soils tested were suppressive to ginseng root rot, whereas fifteen of 16 C. destructans-suppressive soils were suppressive. Ginseng root rots of ginseng disease-suppressive soils were in the range of 1.0-17.4% in F. solani-suppressive soil and 0.2-20.4% in C. destructans-suppressive soil, respectively.

• The Journal of the Korean dental association
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• v.55 no.2
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• pp.156-164
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• 2017

Purpose: The aim of this in vitro study was to assess changes in remineralization by stimulated human saliva over a short period of 48 hours with quantitative light-induced fluorescence (QLF) technology. Materials and Methods: Bovine incisor surfaces were demineralized for 10 days. Two types of stimulated saliva were collected from 7 healthy persons. 24 hours after tooth brushing (Stimulated saliva group) and immediately after tooth brushing with 1,000 ppm NaF dentifrice (Dentifrice saliva group). The specimens were immersed in saliva and fluorescence images were obtained by QLF-digital (QLF-D $biluminator^{TM}$,) at 2, 4, 6, 12, 24, and 48 hours fluorescence loss (${\Delta}F%$) of the lesions. A paired t-test was performed to assess fluorescence differences between before (${\Delta}F_{baseline}$) and after (${\Delta}F_{treatment\;time}$) the remineralization process. Results: Before the remineralization, the mean ${\Delta}F_{baseline}$ of the initial demineralized specimens was $-18.42{\pm}0.15$ (%). In both groups, the ${\Delta}F$ values obtained at baseline and after 2 hours were statistically significant (P < 0.001), indicating recovery of the lesions by approximately 40% after 2 hours. After 48 hours, remineralization rates were slightly higher (49%) for the stimulated saliva group than for the dentifrice saliva group (41%), but the difference was not statistically significant. Conclusions: With QLF minute degrees of remineralization by saliva can be measured in periods as short as 2 hours. Additionally no significantly higher effects of remineralization were observed in the dentifrice saliva group when compared to the stimulated saliva group.

• The Journal of Korean Medicine
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• v.18 no.1
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• pp.430-445
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• 1997

In order to know the effects of Calculus $Bovis{\cdot}F디$ Ursi aqua-acupuncture ($C{\cdot}F$ aqua-acupuncture) to the liver damage, we carried out the treatment of $C{\cdot}F$ aqua-acupuncture and injection of Kam-Du-Tang on the liver damaged rat which is induced by aconitine, and then ultrastructural study has been to the liver tissue. The results were as follows: 1. In the hepatic cell of normal group, the nuclear envelope is round and electro-density of nucleoplasm is relatively low, and have one or two large nucleolus. Cell organelle is developed rough endoplasmic reticulum(RER) and many mitochondria, glycogen granules, smooth endoplasmic reticulum(SER) and Golgi apparatus. 2. In 24 hours control group, nuclear envelope is very irregular, RER and most of cell organell is shown that destroyed by aconitine. This is similar to the 48 hours control group. In 72 hours control group, RER is recovered somewhat but cristae of mitochondria is not seen the shape 3.In 24 hours $C{\cdot}F$ aqua-acupuncture group, nuclear envelope is very irregular and cristernae is very dilatable and many mitochondria is dilationed and the cristae is not definite like the control group. In 48 hours $C{\cdot}F$ aqua-acupuncture group, nuclear envelope is relatively round and chromatin is regular. Cristernae of RER and ribosme is somewhat imperfect but is similar the normal group, and the cristae of mitchondria is shown definitely like the normal group. In 72 hours $C{\cdot}F$ aqua-acupuncture group, nuclear envelope is round and cell organell is similar to normal group. 4. In 24 hours Kam-Du-Tang group, nuclear envlope is very irregular and cell organelles are destroyed by the effects of aconitine. In 48 hours Kam-Du-Tang group, nuclear envelope is somewhat irregular but chromatin is relatively regular. RER is seperated regularly through the cytoplasm, but cannot make the structure of lamina, and cistennae is very dilationed. many of glycogen granules is seperated regularly. In 72 hours Kam-Du-Tang group, RER makes the lamina. Mitochondria is a little but inner space is dilationed so the shape of is not definite and a lot of glycogen granules are accumulated in several places. It see the above result, hepatic cell that is damaged by aconitine is effected chiefly by the $C{\cdot}F$ acupuncture and effect of acupuncture is similar to the detoxicated effect of Kam-Du-Tang.

• Korean Journal of Veterinary Service
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• v.42 no.2
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• pp.93-112
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• 2019

Calf diarrhea is a common disease in young claves and is still a major cause of productivity and economic loss in livestock farms. Fecal samples from Korean native cattle (n=100) with diarrhea from 64 farms in Gwangju area, Korea from september 2017 to December 2018 were examined for shedding of important protozoan parasitic, viral and bacterial pathogens using culture, rapid test kit and PCR methods. Of 57 (89.1%) of the 64 Korean native cattle farms examined had samples infected with at least one of the investigated pathogens. Among 100 fecal samples, 88 samples were positive for at least one the twelve pathogens and 51 samples were simultaneously positive for two or more pathogens by culture and PCR assay. Bovine group A rotavirus (BRV) was the most common pathogen, found in 43/100 (43.0%) samples on 32/64 (50.0%) farms. Subsequently, kobuvirus (30.0%), pathogenic E. coli (29.0%), bovine parvovirus (17.0%), Giardia spp. (13.0%), Eimeria spp. (10.0%), Clostridium perfringens type A (8.0%), bovine torovirus (8.0%), bovine viral diarrhea virus (6.0%), bovine coronavirus (5.0%), bovine norovirus (2.0%) and Cryptosporidium spp. (2.0%) were detected. Nebovirus, kırklareli virus, bovine adenovirus, Salmonella spp. and intestinal parasites were not detected. Of the 72 calves sampled in this age group, 64 (88.9%) samples were positive for at least one enteropathogen. BRV was identified in 34/72 (47.2%) samples from 27/48 (56.3%) farms. Subsequently, pathogenic E. coli (30.6%), kobuvirus (29.2%), BPaV (22.2%), Giardia spp. (15.3%), Eimeria spp. (9.7%), BVDV (6.9%), Cl. perfringens type A (6.9%), BCoV (4.6%) and Cryptosporidium spp. (2.8%) were detected in fecal samples. A total of ninety-six strains of E. coli were isolated from one hundred fecal samples collected from Korean native cattle with diarrhea. The presence of stx1, stx2, eaeA, LT, STa, STb, ehxA, saa, F4, F5(K99), F6, F17, F18 and F41 genes in the isolates was investigated by PCR. Out of ninety-six E. coli isolates screened for specific genes, 30 strains E. coli were identified to harbor shiga toxin-producing E. coli (STEC) 7 (7.3%), enterohemorrhagic E. coli (EHEC) 8 (8.3%), enteropathogenic E. coli (EPEC) 6 (6.3%), enterotoxigenic E. coli (ETEC) 2 (2.1%) and STEC/ETEC hybrid 7 (7.3%). This study provides epidemiological estimates of the prevalence of Korean native cattle's enteropathogens in Gwangju area, Korea, which would be used for cattle farmers and veterinarians to select appropriate therapeutic method.

• Journal of Animal Environmental Science
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• v.11 no.3
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• pp.207-214
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• 2005

To reduce phosphorus and nitrogen from the swine wastewater, magnesium chloride $(MgCl_2)$ was used as a reaction material for both soluble phosphorus (SP) and ammonia-nitrogen (AN). The initial value of SP content were $471mg/\ell$ far aeration test and $515 mg/\ell$ for NaOH addition test, but treatment of $MgCl_2$ reduced SP value to $5mg/\ell$ and $4mg/\ell$. The removal efficiency of $MgCl_2$ for SP showed $99\%$ in both treatment, and the removal efficiency of $MgCl_2$ for AN showed $15\%$ with treatment of aeration and $18\%$ with NaOH. All the experiments were done in a low temperature of 6 to $8^{\circ}C$, suggesting that this methods are possibly able to apply to a cold weather conditions. Moreover, the struvite crystal structure was identified by electronic microscope, implying that $MgCl_2$ is an effective material for removal of SP from swine wastewater In addition to the increased removal rate of the AN in wastewater, both $MgCl_2$ and $KH_2PO_4$ were added. The SP value was reduced by $99\%$ with 2g addition of the phosphate. The SP removal rate by 4g addition of the phosphate was increased only as $15-19\%$, but the quantity of removed SP was higher than that of 2g addition test. The value of AN was not reduced as expected by adding $KH_2PO_4$. The AN removal rate were low as $18\%$ and $15\%$ like as the level of the former test with $MgCl_2$ alone. Therefore, it is needed to examine closely the reaction mechanism f3r reducing both SP and AN simultaneously.

• Economic and Environmental Geology
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• v.34 no.5
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• pp.471-483
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• 2001

The pH values of the mine and surface water from the Tohyun mine creek were higher compared with those of groundwater, and 2nd round samples in same sites were even alkaline. The stream and mine waters belong to the characteristics of (Ca+Mg)-(SO$_4$) and (Ca+Mg)-(HCO$_3$) types, and groundwaters have to the (Ca+Mg+Na+K)-(HCO$_3$+SO$_4$) type. As the 2nd samples. concentrations of mostly anions are increasing compared with the forder samples. However, the mostly cation concentrations are decreasing. The hydrogeochemistry indicate that water quality is different chemical characteristics and evolution trends. The range of $\delta$D and $\delta$$^{18}$ valutes (relative to SMOW) in the waters are shown in -62.2 to -70.1$\textperthousand$, and -8.1 to -9.4$\textperthousand$. The values are plowed parallel to $\delta$D=8$\delta$$^{18}$ O+ (6$\pm$4). The d values of groundwater show 2.4, which is lower than the surface (5.2) and mine (7.6) waters. Strontium concentra titans range from 0.025 to 11.844 mg/$\ell$ in all kinds of water samples, but the groundwater has the highest contents The $^{87}$ Sr/$^{86}$ Sr ratios (0.7115 to 0.7129) show more lightened to the groundwater. The $\delta$$^{18}$ O value, Ca and Sr contents are decreased with $^{87}$ Sr/$^{86}$ Sr increasing, because it is support to the altitude effects of the sampling sites rather than a water-rock interaction of environmental isotope. Using computer code of WATEQ4F, saturation indices of albite, Quartz, gibssite and gypsum are calculated to be soluble. The calcite and dolomite show super saturation state, however, clay mineral species are plotted boundary between undersaturation and supersaturation. In the Tohyun mine creek, reaction materials with ore wastes arid precipitation have influence upon increasing EC and TDS of the waters independent of pH. The SO$_4$ concentrations in the mine water is 181.845 mg/$\ell$. This is abruptly increase in surface water and then detected 249.727 mg/$\ell$ in the groundwater. As a results of the calculated sulfate mineral solubilities, the sulfate ions became saturation states an above 150 mg/$\ell$ concentrations.

• Research in Plant Disease
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• v.18 no.4
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• pp.304-309
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• 2012

Fusarium wilt, caused by three races of Fusarium oxysporum f. sp. lycopersici, is one of the most important disease of tomato (Solanum lycopersicum) worldwide. A total of 1,906 tomato accessions were screened for the resistance to Fusarium wilt using I-3 SNP marker and high resolution melting analysis. Results showed that 97 accessions were homozygous resistant, 8 accessions were heterozygous resistant and 1,801 were homozygous susceptible. Accessions containing resistance were identified in 65 accessions of S. lycopersicum var. lycopersicum, 13 accessions of S. lycopericum var. cerasiform, 8 accessions of S. pimpinellifolium, 3 accessions of S. habrochaites, 3 accessions of S. corneliomulleri, 1 accession of S. galapagense, 3 accessions of S. peruvianum, 1 accession of S. chilense. For accurate evaluation of the Fusarium wilt resistance, however, screening to race 1 and race 2 and bio-assay still remain to be evaluated.

• Economic and Environmental Geology
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• v.28 no.6
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• pp.541-551
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• 1995

The Yeongdeog gold-silver deposits at Jipum, Gyeongsangbugdo, is of a middle Paleogene $(45.52{\pm}1.02Ma)$ vein type, and is hosted in shale and sandstone of Cretaceous age. Based on mineral paragenesis, vein structure and mineral assemblages, the ore mineralization can be divided into two distinct depositional stages. The early stage is associated with base-metals such as pyrite, arsenopyrite (27.99~30.99 at%), hematite, rutile, pyrrhotite, sphalerite (10.53~18.42 FeS mole%), chalcopyrite and galena with wallrock alteration such as chlorite, sericite and pyrite. The late stage is characterized by the Au-Ag mineralization such as electrum, Ag-bearing tetrahedrite, freibergite, pyrargyrite, unidentified mineral, pyrite, sphalerite (1.08~5.57 FeS mole%), chalcopyrite and galena. Fluid inclusion data indicate that fluid temperatures and salinities range from 343 to $227^{\circ}C$ and from 8.3 to 5.7 wt% eq. NaCl in early stage, respectively. Temperatures and salinities of NaCl eq. wt% range from 299 to $225^{\circ}C$ and from 12.9 to 4.3 in late stage, respectively. They suggest that complex cooling histories were occured by the mixing of the fluids. Sulfur fugacity $(-logfs_2)$ deduced by mineral assemblages and composition ranges from 8.3 to 14.7 atm. in early stage, and from 8.8 to 14.5 atm. in late stage. It suggests that the mineralization was related to decrease of temperature in early stage and fluctuations of $fS_2$ with decrease of temperature in late stage. Sulfur and oxygen isotope compositions are 4.48~5.60‰ and 9.25~10.8% in early stage, and late stage is 4.84~7.00‰ and 5.7‰, respectively. It indicated that hydrothermal fluids may be magmatic origin with some degree of mixing of another water during paragenetic time.