• Korean Journal of Soil Science and Fertilizer
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• v.14 no.1
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• pp.17-23
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• 1981

The effects of potassium chloride and potassium sulphate on the volatilization of ammonia from acidic clayloam and tidal sandy clay loam soils applied with urea under flooded conditions were studied in a laboratory experiment. Results obtained were as follows; 1. The application of potassium to the acidic soil promoted the volatilization of ammonia through increasing soil pH. 2. The application of potassium to urea treated on the tidal soil which lead pH over 8.0 under flooded reduced conditions decreased the wet soil pH and reduced the volatilization of ammonia from the soil. These effects of potassium were more pronounced in the potassium sulphate treatment than in the potassium chloride. 3. More ammonia was volatilized from the acidic soil applied with potassium sulphate, however, the effects of potassium fertilizers applied to the high pH tidal soil seemed to be masked by high salt content of the soil. 4. Urea brought up soil pH significantly. Potassium sulphate was more effective than potassium chloride in raising pH of the acidic soil, though the reverse could be true in the tidal soil with high pH. The reduction of sulphate might be a major cause for the pH change.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.6
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• pp.762-771
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• 2010

Two experiments were conducted to determine i) the fermentation characteristics of catfish by-product (C) ensiled with rice bran (RB) or sugarcane molasses (M) in different ratios, and ii) the digestibility of the silages in growing pigs. In the ensiling experiment, there were three ratios of C, ensiled with RB or M, of 8:2, 7:3 and 6:4 (wet basis for C and air-dry basis for RB and M). The six treatments were CRB8:2, CRB7:3, CRB6:4, CM8:2, CM7:3 and CM6:4, with 3 replications per treatment and seven sampling times. The pH of CRB7:3 and CRB6:4 decreased (p<0.05) from the first week and stayed stable until 8 weeks of ensiling, but the pH did not decrease in CRB8:2. The pH of CM8:2, CM7:3 and CM6:4 decreased rapidly from the first week until week 8. Dry matter (DM) and crude protein (CP) contents were slightly lower when catfish by-product was ensiled with RB than with M. Ammonia content in all treatments increased (p<0.05) during ensiling. Lactic acid content in silages with molasses increased from the first week, with the highest value at week 4. However, the lactic acid content in CRB8:2 did not increase with time and had the lowest value of all treatments. Acetic acid proportions of total volatile fatty acids were low at day 0, with the highest value at day 7, decreasing slowly until 8 weeks. The butyric acid proportion was highest at day 0 and decreased up to week 8. The proportion of propionic acid increased during ensiling. The digestibility experiment had a 4${\times}$4 Latin-square design and included 4 castrated crossbreed (Yorkshire${\times}$Landrace) male pigs fed four diets. The basal diet (BD) included rice bran, broken rice and maize meal, and the other three diets included fish meal (FMD) or catfish by-product ensiled with rice bran (CRBD) or sugarcane molasses (CMD). The silages chosen were those which gave the best results in the ensiling experiment for each additive. The coefficient of total tract apparent digestibility (CTTAD) of DM and organic matter (OM) was not significantly different among treatments. The CTTAD of CP was not different among the silage diets, but was lower in BD (p<0.01). The CTTAD of ether extract (EE) was higher in the catfish by-product silage diets than in FMD and BD. There was no significant difference in the digestibility of DM, OM, CP and EE between the fish meal and the by-product silages. In conclusion, catfish by-product can be successfully preserved by ensiling. Moreover, the total tract apparent digestibility of OM, CP and EE in ensiled catfish by-product was comparable with that of fish meal.

• Journal of the Korean Applied Science and Technology
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• v.31 no.4
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• pp.694-702
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• 2014

The micron-sized ITO(indium tin oxide) particles were prepared by spray pyrolysis from aqueous precursor solutions for indium, and tin and organic additives solution. Organic additives solution with citric acid(CA) and ethylene glycol(EG) were added to aqueous precursor solution for Indium and Tin. The obtained ITO particles prepared by spray pyrolysis from the aqueous solution without organic additives solution had spherical and filled morphologies whereas the obtained ITO particles with organic additives solution had more hollow and porous morphologies with increasing mole of organic additives. The micron-sized ITO particle with organic additives was changed fully to nano-sized ITO particle whereas the micron-sized ITO particle without organic additives was not changed fully to nano-sized ITO particle after post-treatment at $700^{\circ}C$ for 2 hours and wet-ball milling for 24 hours. The size of primary ITO particle by Debye-Scherrer formula and surface resistance of ITO pellet were measured.

• Journal of Korean Society of Environmental Engineers
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• v.33 no.2
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• pp.103-112
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• 2011

The main objective of this research was to estimate Nitrogen budget of South Korea in 2008. Input-output budgets for nitrogen fluxes were categorized into three sections: cities, agricultural area, and forest. Chemical and biological fixation, dry and wet deposition, imported food and feed were used as the nitrogen input. Crop uptake, volatilization, denitrification, leaching, runoff, and forest consumption were used as the nitrogen outputs. Annual total nitrogen input was 1,294,155 ton/yr, and output was 632,228 ton/yr. Comparison with a previous research in 2005 indicates that nitrogen input was decreased by 1.9% due to the decrease in nitrogen fertilizer while nitrogen output was decreased by 6.3%. Non-point source (NPS) pollution was also estimated by mass balance approach, which increased by 22% than the previous research in 2005. The emission of nitrous oxide ($N_2O$) caused by denitrification was newly examined in this research. About 8,289 ton/yr of $N_2O$ was released from agriculture area and domestic wastewater treatment plant.

• Environmental Analysis Health and Toxicology
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• v.20 no.3 s.50
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• pp.195-203
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• 2005

Cytochrome P45O 17$\alpha$-hydroxylase (CYPI 7) and cytorhrome P45O aromata.ie (CYPI 9) are key steroidogenic enzymes in androgen and estrogen synthesis. ThiL study evaluated the effects of nonylphenol (NP) on CYP17 and CYP19 expression in the ovary of Sprague-Dawley rats. All female rats were administered orally with the vehicle (control, corn oil), diethylstilbestrol (DES, 5.0 $\mu$g/kg) and NP (50, 100, or 200 mg/kg/day), which was startinB when they were weaned at 21 days of age for 20 days. Twenty four hours after final dose, the animals were anelthetized with ether. Significant decreases in the uterus (wet weight) were observed with 5.0 $\mu$g/kg/day DES (78$\%$, of control) and 200 mg/kg/day NP (62$\%$ of control), respectively Additionally, ovarian weight was significantly decreased with 5.0 $\mu$g/kg/day DES (63$\%$ of control) and 200 mg/kg/day NP (72$\%$ of control). The serum estradiol levels were sligHtly lower in DES and high dose NP treatment groups, but the 74 levels were not affected by DES and NP. The expression of the ovarian CYP19 gene increased with low doses (50 and 100 mg/kg/day) of NP. while DES and high dose oi NP (200 mg/kg/day) did not affect on the CYP19 mRNA levels. In contrast to the CYP19 gene, the CYP17 gene expreLsion level was significantly down-regulated by the DES and 200 mg/ks/day NP. This result suggestE that NP inhibits ovarian estrogen synthelis by supprelsing CYP17 mRNA efprelsion, And different mechanisml might exist for the expression of Lteroidogenic CYP17 and CYP19 genes in the ovary of Sprague-Dawley rats in response to NP.

• Journal of environmental and Sanitary engineering
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• v.13 no.3
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• pp.148-157
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• 1998

Leachate is a result of the percolation of precipitation, uncontrolled runoff, and irrigation water into the landfill and can also include water initially contained in the waste as well as infiltrating groundwater. Behaviour of leachate by rainfall was studied to evaluate the variation of leachate generation and contaminants by rainfall in Sudokwon Landfill from January 1998 to October 1998. The quantity of leachate generated was measured with a flow meter, and the concentrations $BOD_5$, CODcr, T-N, $NE_3-N$, SS of leachate were also measured. Principal outcome obtained in this study are as follows : the quantity of leachate generated was the highest on August, the highest leachate generation volume in this period was 11,913㎥ and the lowest was $6,261m^3$. Although the similar amount of precipitation of 80mm applied to the two samples, there were difference in leachate generation due to precipitation duration, precipitation frequency, wet condition of solid wastes. As the result of regression analysis, the correlation coefficients(r) between the quantity of leachate generated and precipitation were 0.823, 0.976 between $BOD_5$ and CODcr, 0.992 between T-N and $NE_3-N$. As the quantity of leachate generated increased 48%, the concentration of $BOD_5$ and CODcr decreased 51% and 50% respectively. Therefore it was showed that the pollutant concentrations in leachate were diluted by precipitation. The concentrations of $BOD_5$ and COBcr in the rainy season were 2000~4000mg/1, 4000~6000mg/1 respectively, and 1000~3000 mg/1, 3000~5000 mg/l in the dry season. The loading of SS, $BOD_5$, CODcr(kg/month) on July was increased by 2.9 times, 2.8 times, 2.2 times with a basis on March. Therefore countermeasure of treatment facilities according to increase of loading by rainfall in summer is necessary.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.7 no.3
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• pp.175-182
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• 2009

The spent cationic exchange resins and anionic exchange resins were separated from mixed spent exchange resins by a fluidized bed gravimetric separator. The separated resins were identified by an elemental analysis and thermogravimetric analysis. The each test sample was prepared by diluting the slurry made by wet ball milling the cationic exchange resins and the anionic exchange resins separated as a spherical granular form for 24 hours. The resulting test samples showed a slurry form of less than $75{\mu}m$ of particle size and 25,000ppm of $COD_{cr}$. The decomposition conditions of each test samples from a thermal power plant were obtained with a lab-scale(reactor volume : 220mL) supercritical water oxidation(SCWO) facility. Then pilot plant(reactor volume : 24 L) tests were performed with the test samples from a thermal power plant and a nuclear power plant successively. Based on the optimal decomposition conditions and the operation experiences by lab-scale facility and the pilot plant, a commercial plant(capacity : 150kg/h) can be installed in a nuclear power plant was designed.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.19 no.4
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• pp.345-354
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• 2007

A sedimentation analysis has been attempted to figure out sedimentation environment due to construction of coastal jetties, such as fish harbor dike, flow guided dike and jetty in shallow Kusipo area, in which tidal range marks up to 6.6 meters in spring tide. As an initial approach of understanding field measurement were done on several stations along reference lines with total station and photo analysis taken by remote controlled small air craft far one and half years. Also numerical tests were done by 2-D ADCIRC model considering dry-wet treatment to evaluate flow and bottom shear stress variations. According to direct measurement, deposition seems to be dominant on Kusipo beach. Model results show bottom shear stress lessens to $0.10{\sim}0.15\;N/m^2$ on most shadow zone of jetties and the inner zone is suffering sedimentation as a result of dike construction. However this is the first approach with limited analysis, thus it should be dealt further considering physical characteristics of bottom sediments in a complete sediment model on upcoming study.

• Applied Biological Chemistry
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• v.34 no.4
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• pp.373-378
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• 1991

The skin and fleshy substance on the net fiber of sponge-gourd fruit pressed mechanically was removed with 0.2% NaOH solution in $3{\sim}5$ hours. The treatment of 0.2% NaOH with 0.02% Monopol(non-ionogenic polyoxethylen derivative) as surfactnat and with 0.1% $Ca(OCl)_2$ as bleaching agent enhanced the effect to remove the fleshy substance and improve the quality of net fiber. Also, the wet hardness and tensile strength of net fiber were controlled by the crosslinkage of the fiber with glu tardialdehyde, glyoxal, and formalin, respectively. The net fiber was stable on the acid and alkaline solutions. Also the range of temperature to degradate the fiber was $338{\sim}385^{\circ}C$. These values indicated a fair stability. The improved net fiber can be used for raw material of bath, dish washing, oil and gas filter, and many kinds of decorations.

• Journal of Dental Rehabilitation and Applied Science
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• v.25 no.2
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• pp.157-169
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• 2009

The aim of this study was to evaluate effect of implant abutment screw coating treatment on joint stability, investigating mechanical properties of these. For this study used $ExFeel^{(R)}$ external hexed implant system and $15mm{\times}1mm$ discs. Experimental group was $1{\mu}m$ TiN, TiCN, TiC coated abutment screws and discs. To know mechanical property, i evaluated adhesion strength, surface hardness, using disc, corrosion test using screw. The results were as follows : rotation angle of coated screws increased than that of non-coated screw because of lower friction coefficient, especially TiC coated screw group had the largest value, but removal torque decreased in all coated screws (p<0.05). Torque loss before and after fatigue test was the smallest in TiC-coated screws, and the largest in non-coated screws (p<0.05), and there was no statistically significant difference between dry condition and wet condition of screws because of higher surface hardness and lower friction coefficient. From the above results, TiN, TiCN, TiC coating group had high abrasion resistance, especially TiC coated group which had low torque-consuming, high rotation angle as low friction coefficient will be considered to influence on implant abutment screw joint stability positively.