• Journal of Korean Society of Water and Wastewater
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• v.28 no.2
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• pp.249-255
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• 2014

So many drinking water treatment plants are under various difficulties by new reinforced effluent standards. Since the target turbidity, much higher than annual average, for designing sludge thickener have to be set to confront high turbidity season, the sludge at thickener should be put up for a long time during usual days. So the soluble manganese and chloroform may be formed under the anaerobic environment in the sludge thickener when the sludge retention time is longer with low turbidity. This phenomenon results in difficulties to keep regulatory level of the discharged effluent. For an effort to overcome the problems, a sludge aeration was successfully implemented into the thickening process. As a result, the final effluent quality and sludge volume were much improved; 41 % of manganese, 62 % of chloroform and 35 % of sludge volume. Additionally, effluent quality was improved ; 61 % of Manganese on aeration with pH control and we could make sure of stability effluent quality despite a long sludge retention time. We recommended the standard of installation sludge aeration equipment to nationally supply water treatment plant under effluent water quality problem ; Manganese, Chloroform, etc.

• Journal of Sericultural and Entomological Science
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• v.47 no.1
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• pp.36-40
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• 2005

This studies were carried out to develop the new silk degumming method by elelectrolyzed alkaline water on the silk degumming process. Using to this method, it could be collect pure sericin from the degumming water, because the degumming water by elelectrolyzed alkaline water was not contaminated by chemicals including soap. The range of elelectrolyzed alkaline water was pH 11.5 to 11.7 and maintained the first value for 8 days under the cool and closed conditions. The degumming ratio of silk was higher in elelectrolyzed alkaline water(pH 11.5~11.7)than that of soap and alkaline bath. When the pH value of elelectrolyzed alkaline water was adjusted at pH 11.0, the degumming ratio of silk was similar to that of soap and alkaline degumming. After degumming the pH value of degumming water decreased largely in the elelectrolyzed alkaline water compared to that of soap and alkaline bath. The tenacity and elongation of degummed silk by elelectrolyzed alkaline water was almost same those of soap and alkaline degumming for 90 min.

• Korean Journal of Food Science and Technology
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• v.36 no.2
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• pp.355-360
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• 2004

Residual contamination levels of natural microflora in strawberries were evaluated. Approximate counts of total aerobic mesophilic bacteria, total coliforms, and lactic acid bacteria were 8, 2, and 3 log CFU/g, respectively, whereas those of Escherichia coli and yeasts/molds were under the detection limit (<10 cells/g). Growth inhibition degrees of total aerobic mesophilic bacteria, total coliforms, and lactic acid bacteria were also evaluated based on three hurdles of preservative, storage temperature, and pH of strawberry paste prepared as model system. Strawberry paste was stored at low ($4^{\circ}C$), room ($20^{\circ}C$), and high ($37^{\circ}C$) temperatures. Potassium sorbate was added as a preservative up to 0.1%. Acidity of strawberry paste was adjusted to pH 4 or 7. During 7-day storage, inhibitory effects of the hurdles against bacterial groups were: storage temperature > pH of strawberry paste > addition of potassium sorbate. Combination of three hurdles most effectively inhibited growth of residual microflora.

• Korean Journal of Organic Agriculture
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• v.24 no.3
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• pp.497-510
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• 2016

This study was carried out to get basic resources for the industrial use of Lactobacillus bulgaricus SP5. The antibacterial activity of the supernatant obtained from Lactobacillus bulgaricus SP5 was tested against the pathogenic bacteria such as Escherichia coli KCCM 11234, Salmonella enteritidis KCCM 3313, Salmonella enteritidis KCCM 12021, and Salmonella typhimurium KCCM 40253. The supernatant of L. bulgaricus SP5 showed antibacterial activity against tested pathogenic bacteria. The antibacterial activity was examined after adjusting pH and heat treatment of supernatant. Heat treatment of supernatant had antibacterial activity against pathogenic bacteria at all temperature. However, pH changes showed no antibacterial activity. Antibacterial activity of the supernatant was confirmed to be due to organic acids (lactic, acetic, phosphoric, succinic, pyroglutamic, citric, malic, and formic acid).

• Journal of Korean Society of Environmental Engineers
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• v.27 no.9
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• pp.965-969
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• 2005

Current density is an important operating parameter in the ion-exchange membrane process. We observed the effects of fouling of a Neosepta AMX anion-exchange membrane(Tokuyama Soda, Japan) in 0.02 M NaCl solution containing 100 mg/L sodium humate. Membrane fouling was analyzed by measuring the change in the electrical resistance in the under- and over-limiting current density regions. The experimental results found that membrane fouling was negligible at under-limiting current densities, but was increased significantly when an over-limiting current was supplied. After the fouling experiments, the current-voltage curves for the fouled membranes were measured. From the curves, we observed increased electric resistance and reduced limiting current density(LCD), caused by the accumulation of humic acid on the membrane surface. Furthermore, membrane fouling increased as the acidity of the electrolyte solution containing humic acid increased. This occurred because the fouling of an anion-exchange membrane is affected more by the physicochemical properties of the humic substance than by the surface charge of the humate.

• Korean Journal of Soil Science and Fertilizer
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• v.38 no.6
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• pp.334-339
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• 2005

Although phosphogypsum can have profound effects on both the physical and chemical properties of certain soils with supplying the essential elements, no widespread use of by-product phosphogypsum will be made unless such uses pose no threat to the public health and soil contaminations. This study was conducted to evaluate the effects of phosphogypsum on the growth of oriental melon and soil properties in plastic film house. Phosphogypsum was treated at the rate of $70kg\;CaO\;10a^{-1}$ and the effects were compared with the treatment of Ca-Mg carbonate. In the treatment of phosphogypsum, early growth of oriental melon was significantly increased comparing to the growth in the Ca-Mg carbonate treatment. Total fruit yield was not different between the treatments of phosphogypsum and Ca-Mg carbonate, but marketable fruit yield was higher in the phosphogypsum treatment. Although Ca and S contents in oriental melon were increased in the phosphogypsum treatment, contents of toxic heavy metals including As, Cd, Cr, Cu, and Pb were not different between the two treatments. Also, soil pH and contents of extractable toxic metals in the soil were not significantly different between the two treatments after the experiment. These results suggest that phosphogypsum can be a valuable substitute for lime materials in high pH soils of plastic film house.

• Microbiology and Biotechnology Letters
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• v.13 no.3
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• pp.173-178
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• 1985

Extracellular amylase from tile filtrate of the submerged culture of Ganoderma lucidum was partially purified by ammonium sulfate precipitation and its properties were studied. The optimum pH and temperature of the enzyme activity were 5.5 and 5$0^{\circ}C$. respectively. This enzyme was most stable at pH 5.0 and stable up to 3$0^{\circ}C$, but it lost completely the activity when it was treated at 6$0^{\circ}C$ for 10 min. The enzyme was activated by the addition of M $n^{++}$, $C^{++}$ and C $u^{++}$, but inhibited by H $g^{++}$, A $g^{++}$ And various enzyme inhibitors and chemical reagents did not affect the enzyme activity. The enzyme hydrolyzed the boiled amylaceous polysaccharides, but it hydrolyzed raw starches very slowly. The activation energy of the enzyme for soluble starch was calculated and found to be 7.06 Kcal per mole. The Km values of the enzyme for soluble starch, amylose, amylopectin and glycogen were 0.16, 0.37, 0.19, and 0.16mg/$m\ell$, respectively. Maltose was found to inhibit the enzyme activity and kinetic analysis revealed a competitive type of inhibition.n.n.n.n.n.

• Asian Journal of Turfgrass Science
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• v.16 no.1
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• pp.11-18
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• 2002

This research was designed to know optimize soil sampling time, soil sampling depth and fertilizers according to season and soil condition in the golf course. One of the results was revealed that sampling point and depth have to be consistent for much fluctuation by sampling. Especially, Soil pH is decreased by soil depth remarkably. Top soil (0-5 cm depth) pH is higher than the sub soils (5-10 cm, 10-15 cm depth). It was confirmed that soil pH would increase when the state of soil is appropriate to H$^{+}$ ion concentration. Therefore, Soil pH modification is always not determined by lime content rather than soil conditions, i.e., Organic matter content, moisture content, and soil air content. More effective fertilizing time according to soil pH correction is the middle of october, and it's quantity is 100 g/$m^2$ silicate and 200 g/$m^2$ lime (Pel-Lime Mini) in this experiment. Recommended soil sampling method for acidity measurement is dividing by soil depth into each 5 cm respectively, rather than mixing 15 cm total soil.

• Resources Recycling
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• v.2 no.4
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• pp.27-32
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• 1993

A process has been studied to recover gallium from steelmaking dust which had several hundreds ppm of gallium. Aqueous solution containing 38 mg/l gallium was obtained by leaching of dust with 2.25 mol/l sulfuric acid. The leach liquor contained iron and zinc about 1,000 times greater than gallium. Gallium was then concentrated by ion exchanger of chelating resin with functional group of amino carboxylic acid after reduction of ferric ion to ferrous ion and pH adjustment. Gallium was concentrated to be 13 g/l in the resulting eluate by double ion exchanges. The liquor was further treated to remove impurities by solvent extraction technique empolying TOMAC as extractant. The galluim with 99% purity was finally obtainable.

• The Journal of Korean Academy of Prosthodontics
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• v.17 no.1
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• pp.79-82
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• 1979

교정경험, 보철물장착 경험, 교합조정, 상하악골절, 및 전신적 질환이 없는 Angle class I 교합을 갖는 100명(名)의 환자에 있어 1000개의 치아를 임상적으로 평가하여, 그 disclusion pattern과 periodontal disease index와의 상호관계를 조사해 본 결과, 14%가canine protection을 하고, 16%가 progressive disclusion을 하며, 46%가 group function을 하고 나머지 24%가 각각 바른 disclusion pattern을 띤다는 것을 알았다. 여기서 C.P.하는 mouth의 치아가 다른 3group보다도 더 낮은 periodontal disease index를 갖는다는 사실이 유의성 있는 통계자료로써 나타났다.