• Resources Recycling
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• v.22 no.2
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• pp.37-43
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• 2013

Unlike the conventional slurry type wire sawing, the diamond wire sawing method adopts diamond plated wire as sawing media instead of slurry consisted of both silicon carbide and oil. Wafering with diamond plated wire leaves solid element of the sludge mostly made up of silicon, and it is not difficult to recover 95% or more of silicon by a simple separation process of oil from the sludge. In this study, silicon was recovered from the sludge by drying process and organic and metal impurities were removed by sintering process. As result 3N grade silica was obtained successfully by thermal processing utilized the fact that the recovered silicon readily combines with oxygen due to fine particle size.

• The Korean Journal of Mycology
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• v.22 no.2
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• pp.153-159
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• 1994

Effects of some sources on the vegetative growth of Naematoloma sublateritium (Fr.) Karst. were investigated using liquid and solid culture media. Temperature, pH, carbohydrates as carbon sources, amino acids as nitrogen sources, the optimal carbon/nitrogen ratio, mineral element and organic acids were studied for good mycelial growth. We could improve a new semisynthetic medium for mycelial growth in N. sublateritium.

• Journal of the Korean Society of Tobacco Science
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• v.2 no.1
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• pp.17-27
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• 1980

From 143 sources of collected samples, the distribution of nicotinophiles were investigated and the biological characteristics as well as the rate of nicotine degradation were determined for the selected 34 strains which could grow successfully in the nicotine media, and one of the most effective strains was chosen and identified at the species level. Nicotinophils were distributed abundantly in the soils rich with organic materials, tobacco seed and root. The selected 34 strains were classified into 7 genus and identified with 4 strains of Arthrobacter, 11 strains of non-pigmented Pseudomonas, 2 strains of pigmented Pseudomonas, 6 strains of Alkaligenes, 5 strains Chromobacter 2 strains of Listeria and 4 strains of Achromobacter. Pseeudomonas and Alkaligenes were better than other genus in the rate of nicotine degradation and tobacco seed and root were also good sources for the isolation of effective nicotinophiles. Amnog 34 strains, strain NCT 27 which exhibited 97.l% of nicotine degradation rate was the best one for nicotine degradation and was indentified with Pseudomonas putida.

• Clean Technology
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• v.19 no.3
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• pp.243-248
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• 2013

Thermally conductive materials are widely used in various applications where effective heat dissipation is required. Graphene shows high potential for various uses owing to high electrical conductivity, good mechanical strength, and high thermal conductivity. Generally previous works used organic solvents are generally used for the dispersion of graphene in fabrication procedure. In order to achieve clean fabrication it is required to use water media. In this study, we fabricated graphene attached poly(methyl methacrylate) (PMMA) microsphere via microfluidic method. With the aid of surfactant, graphene was well dispersed in water which was used as continuous flow. Thermal conductivity was improved with the small amount of graphene addition and this indicate potential use of this system for thermally conductive composite material.

• Korean Journal of Agricultural Science
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• v.41 no.1
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• pp.59-63
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• 2014

Precision farming aims at reduced environmental impacts with increased productivity. Soils are multi-functional media in which air, water and biota occur together and form an essential part of the landscape with a fundamental role in the environment. The requirement for herbicides and fertilizers can vary within a field in response to spatial differences in soil properties. Near infrared (NIR) spectroscopy is widely used today as a nondestructive analytical technique which is capable of determining a number of physio-chemical parameters. The objectives of this study were to develop optimal models to predict chemical properties of paddy soils by visible and NIR reflectance spectra. Total of 60 soil samples were collected in spring from 20 paddy fields within central regions in Korea. Reflectance spectra, moisture contents, pH, total nitrogen (N), organic matter, available phosphate ($P_2O_5$) of soil samples were measured. The reflectance spectra were measured in wavelength ranges of 400-2,500 nm with 2 nm interval. The method of partial least square (PLS) analysis was used to determine the soil properties. The PLS analyses showed good correlation between predicted and measured chemical properties of paddy soils in the wavelength range of 1,800-2,400 nm. Especially, it showed better performance than the previous results which used the entire wavelength range of the spectrophotometer, without considering the optimal wavelength of each soil properties.

• Journal of fish pathology
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• v.5 no.2
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• pp.153-158
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• 1992

From several sites of petroleum storage basement in South Coasts in Korea, various petroleum degrading bacteria have been isolated and characterized as Pseudomonas fluorescens, Acinetobacter baumanii, Pseudomonas maltophila and Pseudomonas aeruginosa, respectively. They show the ability of petroleum degradation on minimal media which contains petroleum as sole carbon source and loose the ability at high concentration of NaCl as increasing the concentration of NaCl from 0.5% to 6%. It has been confirmed that such bacteria have utilized the simple saturate hydrocarbon; n-decane, n-hexane, n-octane and n-decane because petroleum consists of various kinds of organic compounds. It has been also identified that petroleum degrading bacteria habor the plasmid and show the antibiotic resistance against ampicillin, tetracycline and chloramphenicol. These results strongly suggest that the petroleum degrading gene and antibiotic resistance gene might be located on the high molecular weight plasmid.

• Journal of Environmental Health Sciences
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• v.40 no.2
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• pp.127-136
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• 2014

Objectives: This study was conducted to investigate the removal of high odor concentration from swine wastewater treatment facility by full scale biofilter using liquid with deodorant mixed with earthworm cast and distillery sludge. Methods: The supply of the culture liquid to the microorganism on the media in the biofilter increases the activity and growth of biomass. The experimental equipment was biofilter tower with treatment capacity of 90 m 3/min. The experimental conditions included gas flow of $60m^3/min$, retention time of 20 sec, and gas/liquid ratio of 67. Results: With changing season from winter to summer, the inlet odor concentration of ammonia increased from 2.5 ppm to 29 ppm, and of hydrogen sulfide from 21 ppm to 91 ppm, respectively. The odor treatment system with biofilter using the culture liquid was stable when the high loading rate increased and showed excellent removal grade with an average of 96.7% for ammonia, and an average of 93.7% for hydrogen sulfide. The pH and SCOD in the recirculating culture liquid near the bottom of the biofilter tower decreased with operation time, but its influence on the odor removal rate was negligible, because the organic matter (SCOD) was replaced by some culture liquid supplied 2-4 times per day. Conclusions: The biofilter using culture liquid could successfully remove high odor concentration which was generated from swine wastewater treatment facility.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.15 no.1
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• pp.8-18
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• 2005

Adsorption capacity for the charcoal were tasted in this study to verify the performance of them for the use of the sampling media in industrial hygiene field. Two set of experiments were conducted. The first experiment was to test performance of the tested charcoal tube that were assembled in the laboratory with the use of the GR grade charcoal. The other tests were investigate the adsorption capacity of the charcoal tested in this study and charcoals embedded in the commercial charcoal tubes. Known air concentration samples for benzene, toluene, and o-xylene were prepared by the dynamic chamber. 1. At low air concentration levels (0.1${\times}$TLV), there was no significant differences between the tested charcoal tubes and the SKC charcoal tubes. This implies that there is no defect with the adsorption capacity of the charcoal. 2. At high concentration with 60 minutes sampling, the breakthrough were found only in the tested charcoal while no breakthrough were shown in the SKC charcoal. 3. From the breakthrough tests for the charcoal, the micropore volume(Wo) were calculated by the curve fitting with the use of Dubinin/Radushkevich(D/R) adsorption isotherm equation. The calculated values were 0.687cc/g for SKC, 0.504cc/g for Sensidyne, and 0.419cc/g for the tested charcoal(Aldrich). 4. Adsorption capacities were obtained from the isotherm curves shown adsorption capacities at several levels of the challenge concentration. All range of the air concentration concerned in industrial hygiene, the SKC charcoal showed approximately two times of adsorption capacity compared to the tested charcoal.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.7 no.3
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• pp.45-53
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• 1987

The purpose of this research was to study the kinetics of a packed bed aerobic biofilm process. Experiments were carried out by feeding an aerated packed bed reactor with a synthetic wastewater. The reactor packed with glass beads as media had a nominal hydraulic detention time of 5 hours. The flow pattern in the reactor was determined by a tracer test using a NaCl solution to be a completely-mixed type. The results of the research showed that the F/M ratio in the reactor was almost constant since the the biomass increased due to the growth of biofilm as the volumetric organic loading increased. It was also proved theoretically and experimentally that packed bed aerobic biofilm process could be analyzed by the kinetics of completely-mixed activated sludge process with sludge recycle.

• Journal of the Korean Chemical Society
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• v.30 no.2
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• pp.145-151
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• 1986

Using a new conductometric method, dissociation constants of 3-cyano, 4-cyano, 3-amino and 4-aminopyridine were measured in the temperature range 15 ∼ 40${\circ}C$ and pressure up to 2500bar in aqueous media. This method is convenient to apply to the low dissociative acid and base but have to do tedious extrapolating procedure for the ionic conductance in elaborated temperatures and pressures and have to know any reference dissociation constant. The measured dissociation constants were increased as the temperature increase but decreased as the pressure increase. From the constants, various thermodynamic properties were evaluated and discussed for the dissociation reactions.