• Fashion & Textile Research Journal
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• v.16 no.2
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• pp.333-338
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• 2014

This study identifies the effects of sodium sulfate and surfactants in the papain treatment of wool fabrics using L-cysteine and EDTA as activators. The research method involves the use of 2% L-cysteine and 7% EDTA as activators at optimal conditions, papain treatment of wool fabrics with the joint use of sodium sulfates and surfactants, and measurements of the weight loss rate, tensile strength, and whiteness. Results showed that for both 2% L-cysteine and 7% EDTA, the maximum papain activity appeared at 0.5% sodium sulfate concentration. In both cases, the papain activity was enhanced at sodium sulfate concentrations lower than 0.5%. In contrast, the papain activity declined at sodium sulfate concentrations higher than 0.5%. The joint use of EDTA with 0.5% sodium sulfate was proven to be very effective in improving the papain activity. The joint use of 2% L-cysteine with 0.5% sodium sulfate appeared slightly effective in improving the activity but resulted in excessive decrease in the tensile strength and whiteness, compared to improvement in the activity. The joint use of surfactants, in the case of L-cysteine, interrupted the papain activity and decreased the tensile strength regardless of the surfactant type and concentration. In the case of EDTA, however, the joint use with 0.1-5% non-ionic surfactants, 0.1-0.5% anionic surfactants, and 0.1% cationic surfactant appeared to improve the papain activity. The maximum papain activity was observed when 0.1% of surfactant was used, regardless of the surfactant type. The nonionic surfactant was the most effective in improving the papain activity.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2000.11a
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• pp.209-212
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• 2000

As a bench-scale study, transformation of nitrate to nitrogen gas under anoxic condition was determined by using autotrophic denitrifiers containing Thiobacillus denitrificans and elemental sulfur as an electron donor. The research objective is to measure the basic kinetic parameters of autotrophic denitrification reaction on the removal efficiency of nitrate. The results showed that nitrate was almost completely transformed to nitrite in the first 4 days of column operation. After 2 days of accumulation of nitrite, its concentration slowly decreased and the compound was detected less than 0.5 mg/L in 14 days. In the experiment, sulfate concentration in the effluent was the 70~90 mg-S/L and the pH was maintained around pH 7.5. When nitrate concentration of bank filtrate in the real field is considered, this sulfate concentration seems to be acceptable. At 17 cm from the bottom of the column, the effluent showed the highest nitrite concentration, and nitrate concentration decreased rapidly to the Point of 33 cm from the bottom. The results suggest that an appropriate thickness of permeable reactive barriers is about 30 cm.

• Journal of Periodontal and Implant Science
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• v.27 no.4
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• pp.751-765
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• 1997

Periodontal disease is a bacterially causal by disease, To remove plaque and bacteria, it has been necessary to prescribe chemical drug to patient to subjugate therapeutic unvalue by mechanical scaling. As a patient on a high dosage of the antibiotics to maintain the effective concentration may produce unfavorable side effects, this decase demands the Slow-release local drug delivery system. The object of the experiment is to study on the slow-release local drug delivery effects of calcium sulfate compounded with tetracycline that mainly used in periodontal disease. Experimental groups were divided into four classes as follow: Group 1 10% tetracycline compounded modified calcium sulfate paste. Group 2 : compounded and hardened 10% tetracycline and calcium sulfate. Group 3 : compounded 10% tetracycline and calcium sulfate, used Just before hardened. Group 4 : tetracycline-ethylene vinyl acetate fiber. In the four groups, release concentration, it's durability and the period of absorption by times are observed and concluded as follow: 1. An effective concentration($4{\mu}g/ml$) remained until 5 weeks in group 1, 9 days in group 2, 7 days in group 3, 15 days in group 4. 2. It was fully fused at 11.8 days average in group 2 and 14.8 days average in group 3. . There were no statistically significant results in tetracycline concentration until a week in group 2 and 3(p<0.05) These results suggest that tetracycline loaded calcium sulfate release sufficient tetracycline and fused in $11{\sim}14$ days, so calcium sulfate is useful carrier as slow release local drug delivery system.

• Journal of Korean Society of Water and Wastewater
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• v.13 no.2
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• pp.47-54
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• 1999

SRB(Sulfate Reducing Bacteria) converts sulfate into sulfide using an organic carbon source as the electron donor. The sulfide formed precipitates the various metals present in the AMD (Acid Mine Drainage). This study is the fundamental research on heavy metal removal from AMD using SRB. Two completely mixed anaerobic reactors were operated for cultivation of SRB at the temperature of $30^{\circ}C$ and anaerobic batch reactors were used to evaluate the effects of carbon source, COD/sulfate($SO_4^=$) ratio and alkalinity on sulfate reduction rate and heavy metal removal efficiency. AMD used in this study was characterized by low pH 3.0 and 1000mg/l of sulfate and dissolved high concentration of heavy metals such as iron, cadmium, copper, zinc and lead. It was found that glucose was an organic carbon source better than acetate as the electron donor of SRB for sulfate reduction in AMD. Amount of sulfate reduction maximized at the COD(glucose)/sulfate ratio of 0.5 in the influent and then removal efficiencies of heavy metals were 97.5% of Cu, 100% of Pb, 100% of Cr, 49% of Mn, 98% of Zn, 100% Cd and 92.4% of Fe. Although sulfate reduction results in an increase in the alkalinity of the reactor, alkalinity of 1000mg/1 (as $CaCo_3$) should be should be added continuously to the anaerobic reactor in order to remove heavy metals from AMD.

• Journal of Korean Society for Atmospheric Environment
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• v.20 no.6
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• pp.803-810
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• 2004

Water contents in fine particles at Seoul and Gosan are estimated by using a gas/particle equilibrium model, SCAPE (Simulating Composition of Atmospheric Particles at Equilibrium). Also, sensitivity of particulate inorganic ionic concentrations on the total ionic species is estimated. Water content at Gosan is more sensitive to ambient relative humidity (RH) than Seoul. At both sites water content is most sensitive to sulfate concentration among sulfate, nitrate, and ammonium. Solid salts levels and compositions are also studied.

• Clinical and Experimental Pediatrics
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• v.56 no.4
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• pp.159-164
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• 2013

Purpose: Indoxyl sulfate and p-cresyl sulfate are important protein-bound uremic retention solutes whose levels can be partially reduced by renal replacement therapy. These solutes originate from intestinal bacterial protein fermentation and are associated with cardiovascular outcomes and chronic kidney disease progression. The aims of this study were to investigate the levels of indoxyl sulfate and p-cresyl sulfate as well as the effect of probiotics on reducing the levels of uremic toxins in pediatric patients on dialysis. Methods: We enrolled 20 pediatric patients undergoing chronic dialysis; 16 patients completed the study. The patients underwent a 12-week regimen of VSL#3, a high-concentration probiotic preparation, and the serum levels of indoxyl sulfate and p-cresyl sulfate were measured before treatment and at 4, 8, and 12 weeks after the regimen by using fluorescence liquid chromatography. To assess the normal range of indoxyl sulfate and p-cresyl sulfate we enrolled the 16 children with normal glomerular filtration rate who had visited an outpatient clinic for asymptomatic microscopic hematuria that had been detected by a school screening in August 2011. Results: The baseline serum levels of indoxyl sulfate and p-cresyl sulfate in the patients on chronic dialysis were significantly higher than those in the children with microscopic hematuria. The baseline serum levels of p-cresyl sulfate in the peritoneal dialysis group were significantly higher than those in the hemodialysis group. There were no significant changes in the levels of these uremic solutes after 12-week VSL#3 treatment in the patients on chronic dialysis. Conclusion: The levels of the uremic toxins p-cresyl sulfate and indoxyl sulfate are highly elevated in pediatric patients on dialysis, but there was no significant effect by probiotics on the reduction of uremic toxins in pediatric dialysis patients. Therefore, studies for other medical intervention to reduce uremic toxins are also necessary in pediatric patients on dialysis.

• Computers and Concrete
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• v.4 no.2
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• pp.157-166
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• 2007

The paper considers a theoretical model to study sulfate ion diffusion in saturated porous media - cement based mineral composites, accounting for simultaneous effects, such as filling micro-capillaries (pores) with ions and chemical products and liquid push out of them. Pore volume change and its effect on the distribution of ion concentration within the specimen are investigated. Relations for the distribution of the capillary relative radius and volume within the composite under consideration are found. The numerical algorithm used is further completed to consider capillary size change and the effects accompanying sulfate ion diffusion. Ion distribution within the cross section and volume of specimens fabricated from mineral composites is numerically studied, accounting for the change of material capillary size and volume. Characteristic cases of 2D and 3D diffusion are analyzed. The results found can be used to both assess the sulfate corrosion in saturated systems and predict changes occurring in the pore structure of the composite as a result of sulfate ion diffusion.

• Korean Membrane Journal
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• v.7 no.1
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• pp.28-33
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• 2005

The feasibility of producing sulfuric acid and ammonia water from ammonium sulfate was investigated by an integrated process including ammonia stripping (AS) and electrodialysis with bipolar membrane (EDBM). It was suggested that the production of sulfuric acid using ammonia stripping-electrodialysis with bipolar membrane (ASEDBM) was effective in obtaining high concentration of sulfuric acid compared with EDBM alone. AS was carried out over pH 11 and within the range of temperatures, $20^{\circ}C{\~}60^{\circ}C$. Sodium sulfate obtained using AS was used as the feed solution of EDBM. The recovery of ammonia increased from $40\%$ to $80\%$ at $60^{\circ}C$ due to the increased mobility of ammonium ion. A pilot-scale EDBM system, which is composed of two compartments and 10 cell pairs with an effective membrane area of $200 cm^2$ per cell, was used for the recovery of sulfuric acid. The performance was examined in the range of 0.1 M${\~}$1.0 M concentration of concentrate compartment and of $25 mA/cm^2{\~}62.5 mA/cm^2$ of current density. The maximum current efficiency of $64.9\%$ was obtained at 0.1 M sulfuric acid because the diffusion rate at the anion exchange membrane decreased as the sulfuric acid of the concentrate compartment decreased. It was possible to obtain the 2.5 M of sulfuric acid in the $62.5 mA/cm^2$ with a power consumption of 13.0 kWh/ton, while the concentration of sulfuric acid was proportional to the current density below the limiting current density (LCD). Thus, the integrating process of AS-EDBM enables to recover sulfuric acid from the wastewaters containing ammonium sulfate.

• Journal of Microbiology
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• v.34 no.2
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• pp.131-136
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• 1996

In order to known the extend of contribution to the degradation of organic materials and nutrient recycling by sulfate-reducing bacteria (SRB) and methane-producing bacteria (MPB) in sediment, the distribution and activity of these two groups of microorganisms were studied montly in 1994 at two sites, one littoral (Sanggulri) and the other profunndal (DAM), in Lake Soyang. In the seasonal distribution of two microorganisms, SRB were 1.07 $\times$ 10$^{3}$-2.42 $\times$ 10$^{5}$ cells/g-dry weight at Sanggulri, 2.40 $\times$ 10$^{5}$ -1.29 $\times$ 10$^{6}$ at Dam and MPB were 0.52 $\times$ 10$^{3}$ cells/g-dry weight at Sangguri and 1.44 $\times$ 10$^{3}$-6.89 $\times$ 10$^{3}$ at Dam. In these results, the density of SRB in Lake Soyang is much higher than other lakes. These high values might be due to higher sulfate concentration, 0.69-4.05 mM, than normal freshwater, 0.01-1.2 mM. And a good correlation of SRB and chlorophyll a concentration implied that the important environmental factor on distribution of SRB might be the concentration of available organic matter. In a comparison of sulfate-reducing rate and methane producing rate in 1995, the activity of SRB for the degradation of organic matter was higher than MPB by factor of 359. Conclusively SRB superior to MPB in the distribution and activity are more important annearobic bacteria in Lake Soyang sediments.

• Journal of the Korean Ceramic Society
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• v.30 no.6
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• pp.478-484
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• 1993

The influence of reaction conditions on the MnZn ferrite coprecipitation process were investigated using mixed metla sulfate solution and ammonium oxalate. In order to minimize the metallic ion losses and to control the particle size, the optimum reaction conditions were as follows; reaction temperature $25^{\circ}C$, metal sulfate concentration 0.3M, molar ratio of ammonium oxalate/mixed metal sulfate 1.1:1. The production yield was as high as 97.6% of theoretical yield at optimum reaction condition.