• Journal of the Korea Organic Resources Recycling Association
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• v.23 no.4
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• pp.21-31
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• 2015

The aim of this study is to determine the removal efficiency of total nitrogen and phosphorus from treated swine wastewater by Phragmites australis and Miscanthus sacchariflorus var Geode Uksae-1, and to determine its biomass total energy value and biomethane potential. Plants were grown with a bedding mixture either soil and sand or soil, sand, and bioceramic. Treeated swine wastewater with Total nitrogen (TN) and Total phosphorus (TP) of 222.78 mg/L and 66.11 mg/L, respectively, was utilized. The TN and TP removal is higher in the bio-ceramic-soil-sand bedding media treatment. The highest TN removal of 96.14% was performed by Miscanthus sacchariflorus var Geode Uksae-1, but the elemental analysis shows that Phragmites australis contains more nitrogen than Miscanthus sacchariflorus var Geode Uksae-1, indicating higher nitrogen uptake. The highest TP removal of 98.12% was performed by Phragmites australis. The cellulose content of the plant grown with the bioceramic-soil-sand bedding was approximately 3-6% higher than that of the plant grown in the soil-sand bedding. Different growing substrates may have an effect on the fiber content of plants. The biomethane potential of the produced biomass of the plants was between 57.01 and $99.25L-CH_4/kg$ VS. The lignin content is believed to inhibit the breakdown of plant biomass, resulting in the lowest methane production in the Phragmites australis grown in the soil-sand bedding media.

• Applied Biological Chemistry
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• v.36 no.4
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• pp.277-283
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• 1993

In order to brew foxtail millet wine, a folk wine of Cheju, properties of raw materials, optimum brewing conditions were inveatigated. Carbohydrate and crude fat content of glutinuous foxtail millet are 71.27% and 3.47%, respectively. Since the ratio of water to steamed millet and ethanol concentration of wine showed negative correlation, less than 250% water had to added to steamed millet to maintain ethanol concentration in wine above 13%, Sugar consumption and ethanol production increased rapidly for the first 2 days, and main fermentation was done in 4 days. Ethanol concentrations were $13.0{\sim}13.4%$ when foxtail millet was used, and they were $14.0{\sim}14.3%$ for the mixture substrates of 90% millet and 10% rice or barley. Organic acids in millet wine were lactic acid, malic acid and succinic acid. The residual carbohydrates after fermentation were mainly xylose and oligosaccharides. A trace of methanol was detected in millet wine. The content of fusel oil was low, while the concnetration of organic acids was high. Optimum conditions for millet wine-making were as follows. Glutinuous foxtail millet with 10% rice as fermentation source need to be soaked in water and steamed for enough time. Water was added to steamed millet with the ratio of 2 : 1. The resulting mixture was stmnultaneously saccharified and fermented by Aspergillus orzae and Saccharomyces cerevisiae IAM 4274 at $20^{\circ}C$ for a week. Millet wine was prepared after filtering fermented broth while pressing for a week.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.3
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• pp.587-595
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• 2000

The most problems of domestic sewage for BNR(Biological Nutrients Removal) process are deficiency of carbon source and low C/N ratio. Primary sludge fermentation is seemed to be one of the best solutions producing biodegradable organic substrates. Soluble organic materials from sludge fermentation are mainly SCFAs(Short-Chain Fatty Acids) with 2~5 carbon atoms. In this research, it was attempted to apply $A_2/O$ process with the side-stream acid fermenter to improve the nutrients removal efficiency. The result showed that proper SCFAs production is about 3.000mg/L with SRT of 4~5 days. SCFAs yield of approximately 0.10~0.16 mg SCFAs(as COD) per mg of primary sludge(as COD) were achieved. The ratio of acetic. propionic. butyric and valerie acid were 1, 0.7, 0.5 and 0.6. Significant improvements of nutrients removal over 70% in BNR process were observed. thus will reduce the demand for chemical dosing to increase nutrients removal efficiency. When the fermentate was entered $A_2/O$ process, the ratio of phosphate release to substrate uptake amounts to $0.34gPO_4-Pg^{-1}COD$.

• Journal of the Korea Organic Resources Recycling Association
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• v.11 no.4
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• pp.97-104
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• 2003

Hydrogen fermentation of food waste and sewage sludge was performed in serum bottles under various volatile solids(VS) concentrations(0.5~5.0%) and mixing ratios of two substrates(0:100-100:0, VS basis). Full quadratic equations, optimal conditions, and 90% acceptable conditions for hydrogen production potential and rate were obtained using cumulative methane production data and response surface methodology. The specific hydrogen production potential of food waste was higher than that of sewage sludge. However, hydrogen production potential increased as sewage sludge composition increased up to 13~19% at all the VS concentrations. The maximum specific hydrogen production potential of 122.9 mL/g $carbohydrate_{added}-COD$ was found at the waste composition of 87:13(food waste:sewage sludge) and the VS concentration of 3.0%. The relationship between carbohydrate concentration, protein concentration, and hydrogen production potential indicated that enriched protein by adding sewage sludge might enhance hydrogen production potential. The maximum specific hydrogen production rate was 111.2 mL $H_2/g$ VSS/h. Food waste and sewage sludge were, therefore, considered as a suitable main substrate and a useful auxiliary substrate, respectively, for hydrogen production.

• Journal of the Korean Vacuum Society
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• v.15 no.3
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• pp.294-300
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• 2006

We fabricated the distributed feedback (DFB) InP/InGaAs/InP grating structures on InP (100) substrates by metal-organic chemical vapor deposition, and their structural properties were investigated by atomic force microscopy and scanning electron microscopy. Self-assembled InAs/InAlGaAs quantum dots (QDs) were grown on the InP/InGaAs/InP grating structures by molecular beam epitaxy, and their optical properties were compared with InAs/InAlGaAs QDs without grating structure. The duty of the grating structures was about 30%. The PL peak position of InAs/InAlGaAs QDs grown on the grating structure was 1605 nm, which was red-shifted by 18 nm from that of the InAs/InAlGaAs QDs without grating structure. This indicates that the formation of InAs/InAlGaAs QDs was affected by the existence of the DFB grating structures.

• Journal of the Korea Organic Resources Recycling Association
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• v.10 no.1
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• pp.96-101
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• 2002

This research was conducted to find the optimal condition in codigestion of food waste and sewage sludge with various mixing ratios. The analysis of degradation characteristics were based on the variations of methane production as well as methane production rate (MPR). BMP values were getting higher as the addition of foodwaste increased. But the lag-phase were prolonged when the foodwaste was over 40%, Nonlinear regression was conducted with the cumulative methane production data. Not only thermophilic but mesophilic condition, 40% of foodwaste addition showed maximum MPR. Higher mixing ratio which is over 50% were unprofitable in gaining higher MPR values. The most important factor in thermophilic co-digestion was substrate concentration. But in mesophilic co-digestion, both substrate concentration the mixing ratio had major effects on MPR. The most probable reasons of the synergetic effects in co-digestion of foodwaste and sewage sludge were the balanced nutrient expressed as C/N ratio and increased kinetic constants of hydrolysis by the mixed co-substrates.

• Korean Journal of Environmental Biology
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• v.26 no.3
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• pp.233-239
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• 2008

In order to access the water quality using epilithic diatom assemblage index to organic water pollution (DAIpo) in the lower part of the Han River, the diatom samples were collected biweekly at 2 stations by means of artificial substrates of ceramic tiles from February, 2004 to February, 2005. A total of 60 taxa, representing 18 genera 51 species, 7 varieties and 2 forms, of diatoms were identified in the present study. Dominant percentages of Aulacoseria granulata and Melosira varians (Indifferent taxa) were 22.76$\sim$30.30% and 17.44$\sim$34.78%, respectively, and Nitzschia palea (Saprophilous taxa) were 15.00$\sim$31.76% at St. 1. In St. 2, the percentages of dominant species, N. palea, were 19.86$\sim$58.20%. Average DAIpo index was 40.6 in St. 1 and 32.1 in St. 2, and the saprobic level was shown $\beta$-mesosaprobic in the lower part of the Han River. It is suggested that epilithic diatoms as bioindicators and a DAIpo index indicate useful for analy-zing assessment of the water quality.

• Journal of the Microelectronics and Packaging Society
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• v.21 no.3
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• pp.67-71
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• 2014

An attempt to grow high quality GaN on silicon substrate using metal organic chemical vapor deposition (MOCVD), herein GaN epitaxial layers were grown on various Si(111) substrates. Thin Platinum layer was deposited on Si(111) substrate using sputtering, followed by thermal annealing to form Pt nano-clusters which act as masking layer during dry-etched with inductively coupled plasma-reactive ion etching to generate nano-patterned Si(111) substrate. In addition, micro-patterned Si(111) substrate with circle shape was also fabricated by using conventional photo-lithography technique. GaN epitaxial layers were subsequently grown on micro-, nano-patterned and conventional Si (111) substrate under identical growth conditions for comparison. The GaN layer grown on nano-patterned Si (111) substrate shows the lowest crack density with mirror-like surface morphology. The FWHM values of XRD rocking curve measured from symmetry (002) and asymmetry (102) planes are 576 arcsec and 828 arcsec, respectively. To corroborate an enhancement of the growth quality, the FWHM value achieved from the photoluminescence spectra also shows the lowest value (46.5 meV) as compare to other grown samples.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.6 no.2
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• pp.35-44
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• 1986

This paper is a basic study of the experimental results for the treatment of ammonia-nitrogen in the septic tank effluent. The substrates in this experiment are actual septic tank effluent and synthetic waste-water which is similar to septic tank effluent containing a considerable amount of nitrogenous component. Experiments were conducted for organic removal and nitrification using various recycle ratio and hydraulic retention time at each stage. The results obtained show that organic removal rate was above 80% in the 1st and 2nd stage, but as nitrification process was proceeded, above 90% of ammonia-nitrogen was removed in the 3rd and 4th stage. In these cases, the recycle ratio and HRT were found 30 and 7 hrs respectively. In the relation of $NH_4{^+}-N$ removal to $NO_3{^-}-N$ formation in the synthetic waste-water and septic tank effluent, when $1mg/{\ell}$ of $NH_4{^+}-N$ was removed, $NO_3{^-}-N$ formations were $0.95mg/{\ell}$ and $0.82mg/{\ell}$ respectively. And kinetics of nitrification using Biological Fluidized Bed was discussed also.

• Journal of Mushroom
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• v.18 no.3
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• pp.268-273
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• 2020

This study aimed to assess the feasibility of composting spent mushroom substrate (SMS) materials of Lentinula edodes (Le), Hericium erinaceus (He), and Pleurotus ostreatus (Po). The different SMSs were composted for 7 to 10 days at high temperatures over 50℃; the composting procedure was completed in 30 days. A maturity test was conducted using the radish seed germination index and CoMMe-100. The composted SMS (CSMS) from Le and He showed gemination indices of 130% and 81%, respectively, that satisfied the criteria of maturity standard (gemination index over 70%) and the CoMMe-100 analysis. The physicochemical changes of CSMSs included an increase in the pH range from 4-5 to 6-7, slight reduction in the EC to 1-1.4 dS/m, and an organic content of 36.9% in LeCSMS. In LeCSMS, the contents of N, P, and K were 1.2%, 2.3%, and 0.77%, respectively, and heavy metals were detected below the standard value in all CSMSs; the Ca and Mg contents in the CSMSs were increased from 30% to 60% when compared to those in the SMSs. The C/N ratio (from 26-33) in LeSMS and HeSMS decreased to 15.3-15.9 in CSMSs. The growth effect of LeCSMS treatment on pepper seedlings was 60% higher than that in the control groups, one of which was treated with commercial organic compost; the former showed a superior growth effect on the leaf width, leaf length, and leaf number compared to other control groups. In conclusion, LeCSMS and HeCSMS could be utilized as compost resources capable of efficient soil amendment and plant growth promotion.