• 한국식품영양과학회지
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• 제21권6호
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• pp.693-700
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• 1992

도토리의 천연 항산화제로서의 이용성을 검토하기 위하여 도토리 분말로부터 수종의 유기용매를 가하여 항산화성 획분을 추출 분리한 후 대두유, 팜유, 돈지 및 우지에 첨가하고 $60^{\circ}C$에서 저장하면서 POV의 변화를 측정하였으며, 항산화 성분을 TLC 및 HPLC로 분리 동정하였다. 도토리의 일반성분은 수분 11.8~12.0%, 단백질 7.1~7.4%, 전분 65.5~69.4%, 조지방 2.1~2.6%, 조섬유 2.1~3.6% 및 조회분 2.4~2.6%이었으며 total tannin 함량은 4.6~6.8%이었다. 도토리류 분말로부터 acetone : water 및 ethyl acetate를 차례로 사용하여 항산화성 획분을 추출하여 얻어진 추출물의 수율은 2.8~3.1%이었다. 최종단계의 도토리 추출물 중에는 gallic acid, digallic acid 및 gallotannin이 함유되어 있었다. 도토리 추출물의 항산화성분은 주로 gallic acid이었다. 도토리 추출물은 유탁액상태의 기질에서는 강한 항산화력을 나타내었고, 유지에 직접 첨가하였을 때는 항산화력이 인정되지 않았다. 우지 및 대두유탁액에 대산 도토리 추출물의 항산화 효과는 강하였으나 돈지 및 팜유유탁액에 대해서는 약하였다. 도토리 추출물은 0.02%의 농도에서 실용적인 항산화 효과가 인정되었다.

• 한국농공학회논문집
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• 제49권2호
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• pp.75-86
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• 2007

This process which has a connection of biofilter and sulfur-limestone has been developed to treat organic substances including BOD, COD and SS etc. and to treat sulfur-limestone is for denitrification.. The whole process consists of chemical reaction tank, sedimentation tank, trickling filter, denitrification tank The trickling filter is equipped with a reactor filled with absorptive filter, and the sulfur denitrification tank is filled with sulfur-limestone mixed media. After setting up practical facilities whose capacity is 60 tons a day, we have observed the removal efficiencies of pollutants through 60 experiments during Summer and Winter seasons. The average concentration of polluted water was BOD for 3.6 mg/L, $COD_{Mn}$ for 11.3 mg/L, SS for 2.8 mg/L, T-N for 8.6 mg/L, and T-P for 0.8 mg/L, and the rate of treatment efficiencies 96.5%, 84.7%, 96.5%, 79.2%, and 80.8%, respectively was found through the experiments. The average treatment efficiency for BOD and $COD_{Mn}$ was 85.0% and 55.7%, respectively and the average removal efficiency for NH4+-N was 84.9% in the trickling filter. The removal efficiency in the denitrification tank is as follows; The removal rate of $NO_3^--N$ was as high as 93.2% within the compass of pH 6.3 to 7.3 through $16.8{\sim}37.0mg/L$ flown into $NO_3^--N$ and $0.1{\sim}8.3mg/L$ outflown. It had observed that this process has implemented highly efficient and advanced treatment without external carbon sources and internal recycle during its process. In conclusion, this process is suitable for a sewerage in a small village due to the merits of low power consumption and easy maintenance.

• Korean Chemical Engineering Research
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• 제46권3호
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• pp.506-511
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• 2008

본 연구에서는 이트륨과 유로퓸 질산수용액으로부터 솔-젤 및 연소공정에 의한 적색 형광체를 제조함에 있어, 솔-젤반응의 고찰을 통한 반응메카니즘을 해석하고, 제조된 적색형광체의 특성을 알아보고자 하였다. 무정형 구연산염 솔-젤 반응은 반응 초기에 킬레이트화 반응과 가수분해 반응이 완료되었으며, 가수분해의 진행에 따라 축합중합반응은 유기산 형성 축합중합 보다는 물 형성 축합중합반응이 더 우세하였다. 솔-젤 반응의 진행을 위해서는 이트륨(유로퓸 포함)과 젤화 작용제인 구연산 몰 비는 1 : 2 이상이 필요하였다. 솔-젤과 건조과정을 거쳐 얻은 젤 분말의 열분석 결과 형광체를 얻기 위한 소성온도는 $700^{\circ}C$ 이상이 되어야 하며, 젤 분말의 소성 시 소성온도가 증가함에 따라 생성되는 형광체의 결정도가 향상되었으며, 결정립 크기가 증가하였다. 제조된 형광체의 발광특성 분석 결과, 출발용액 내 금속이온(이트륨 및 유로퓸)의 농도, 그리고 소성온도가 증가할수록 발광세기가 증가하였다.

• 한국조경학회지
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• 제30권5호
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• pp.107-115
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• 2002

This study was carried out to compare artificial soil formulated by blending calcined clay and coconut peat with perlite, then to evaluate this soil as a perlite substitute for use as an artificial planting medium. To achieve this, a determination of the physico-chemical properties and it's effect on plant growth were conducted by comparing those with large perlite grains and small grains. The results are summarized as follows: 1) The bulk density was 0.41g/㎤. This density was lower than that of field soil, but higher than that of large perlite grain(0.23g/㎤) and small grain(0.25g/㎤). The porosity, field capacity, and saturated hydraulic conductivity were 71.3%, 49.2%, and 3.8$\times$10-2cm/s, respectively. The air-permeability, water holding capacity, and drainage were better than or equal to that both large and small perlite grain. 2) It was near-neutral in reaction(pH=6.6). It had a high organic carbon content(65.8g/kg) and a low available phosphoric acid content(84.7mg/kg). It was similar to crop soil in cation exchange capacity(11.4cmol/kg). It had a low exchangeable calcium content(0.71cmol/kg), a low exchangeable magnesium content(0.68cmol/kg), a high exchangeable potassium content(2.54cmol/kg), and a high exchangeable sodium content(1.12cmol/kg). Except for the exchangeable potassium and sodium content, the chemical properties were better than or equal to both large and small grain perlite. The excessive exchangeable potassium or sodium content will inhibit plant growth. 3) In Experiment 1, the plant growth tended to be higher compared to that of large and small perlite gains. But in Experiment 2, it tended to be lower. This might be linked to the excessive exchangeable potassium or sodium content. 4) It could be considered as a renewable perlite substitute for greening of artificial soil. But, it would be necessary to leach the excessive exchangeable potassium or sodium to avoid the risk of inhibiting plant growth.

• 보존과학회지
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• 제27권4호
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• pp.415-420
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• 2011

금속 유물의 부식 방지를 위하여 우레탄 코팅제를 제조하였다. 제조된 우레탄 코팅제를 이용하여 그 동안 금속유물 코팅제로 주로 사용된 아크릴계 코팅제의 광택성과 코팅 후에 나타나는 변색 등의 문제점을 해결하고자 하였다. 이를 위하여 합성된 우레탄 코팅제는 아크릴계의 코팅제보다 광택이 낮고 색상 변화가 적도록 제조하였다. 이 코팅제는 기존의 코팅제에 비하여 얇은 코팅 층을 형성하면서도 우수한 접착력을 나타내었으며, 다양한 주위 환경에 의해 나타나는 금속 유물의 표면 산화에 대한 저항력과 표면에서의 발수력이 우수하였다. 또한, 아세톤, 톨루엔, 자일렌 등의 유기용매에 쉽게 용해되는 가역성이 우수한 결과를 나타내고 있어 기존의 아크릴계 금속 유물 코팅 재료를 대체할 수 있는 안정적인 코팅제로 사용할 수 있을 것으로 판단된다.

• 대한환경공학회지
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• 제22권11호
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• pp.2097-2104
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• 2000

자연계에서 발생하는 이취미 문제는 주로 조류나 박테리아와 같은 미생물의 신진대사에 기인한다. 이취미와 관련한 원인물질은 주로 MIB와 Geosmin으로서 이는 9ng/L와 4 ng/L의 아주 저농도에서도 흙과 곰팡이 냄새를 일으킨다. 정수처리공정에서는 분말활성탄을 이용한 이취미 유발물질 제어기술이 잘 알려져 있다. 본 연구에서는 단일성분과 이성분계에 있어서의 흡착등온실험을 통하여 최적의 PAC 투여량과 반응시간에 대하여 고찰하였으며 또한 원수를 이용하여 수중에 포함된 자연유기물질의 영향을 고찰하였다. 연구결과 자연유기물질의 유무에 관계없이 Geosmin의 흡착능이 우수하였으며, 자연유기물질이 존재할 경우 MIB와 Geosmin 모두 4배 정도의 흡착능 저하를 보였다. 초기농도 100ng/L 정도의 원수의 경우 99%의 제거율을 얻기 위해서는 PAC 투여량 20mg/L, 4시간 이상의 반응시간을 필요로 하였다.

• 한국환경과학회지
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• 제19권8호
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• pp.951-960
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• 2010

Sediment works as a resource for electric cells. This paper was designed in order to verify how sediment cells work with anodic material such as metal and carbon fiber. As known quite well, sediment under sea, rivers or streams provides a furbished environment for generating electrons via some electron transfer mechanism within specific microbial population or corrosive oxidation on the metal surfaces in the presence of oxygen or water molecules. We experimented with one type of sediment cell using different anodic material so as to attain prolonged, maximum electric power. Iron, Zinc, aluminum, copper, zinc/copper, and graphite felt were tested for anodes. Also, combined type of anodes-metal embedded in the graphite fiber matrix-was experimented for better performances. The results show that the combined type of anodes exhibited sustainable electricity production for ca. 600 h with max. $0.57\;W/m^2$ Al/Graphite. Meanwhile, graphite-only electrodes produced max. $0.11\;W/m^2$ along with quite stationary electric output, and for a zinc electrode, in which the electricity generated was not stable with time, therefore resulting in relatively sharp drop in that after 100 h or so, the maximum power density was $0.64\;W/m^2$. It was observed that the corrosive reaction rates in the metal electrodes might be varied, so that strength and stability in the electric performances(voltage and current density) could be affected by them. In addition to that, COD(chemical oxygen demand) of the sediment of the cell system was reduced by 17.5~36.7% in 600 h, which implied that the organic matter in the sediment would be partially converted into non-COD substances, that is, would suggest a way for decontamination of the aged, anaerobic sediment as well. The pH reduction for all electrodes could be a sign of organic acid production due to complicated chemical changes in the sediment.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2003년도 생물공학의 동향(XIII)
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• pp.422-427
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• 2003

Rhodopseudomonas palustris P4 can produce $H_2$ either from CO by water-gas shift reaction or from various sugars by anaerobic fermentation. Fermentative $H_2$ production by P4 is fast, but its yield is relatively low due to the formation of various organic acids. In order to increase $H_2$ production yield from glucose, P4 was investigated for the photo-fermentation of acetate which is a major by-product of fermentative $H_2$ production. Experiments were performed in batch modes using both light-grown and dark-grown cells. When the dark-grown P4 was challenged with light and acetate, $H_2$ was produced with the consumption of acetate after a lag period of 25 h. $H_2$ production was inhibited when a nitrogen source, especially ammonium, is present. When the dark-fermentation broth containing acetate was adopted for photo-fermentation with light-grown cells, $H_2$ production and concomitant acetate consumption occurred without a lag period. The $H_2$ yield was estimated as 2.4 - 2.8 mol $H_2/mol$ acetate and the specific $H_2$ production rate was as 9.8 ml $H_2/g$ cell${\cdot}$h, The fact that a single strain can perform both dark- and light-fermentation gives a great advantage in process development Compared to a one-step dark-fermentation, the combined dark- and light-fermentation can increase the $H_2$ production yield on glucose by two-fold.

• 한국응용과학기술학회지
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• 제21권3호
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• pp.231-237
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• 2004

Ga-MFI was synthesized by a hydrothermal process at atmospheric pressure. The effect of mole ratios of reactants on crystallization was also investigated thoroughly. The characteristics of synthesized Ga-MFI was compared with ZSM-5. The synthesis of Ga-MFI was carried out with five different mole-compositions of $\underline{a}SiO_2-\underline{b}Ga_2O_3-\underline{c}Na_2O-\underline{d}TPA_2o-\underline{e}H_2O$. The synthesized Ga-MFI and ZSM-5 were characterized by XRD and FT-IR. The inorganic cation ($Na^+$) and water played an important role in crystallinity and the organic cation ($TPA^+$) as a template played a great influence on yields. With the increase in the amount of $Ga^{3+}$, crystallization time was increased. With a fixed $SiO_2/Ga_2O_3$ ratio of 400, the optimum reaction condition was obtained at $H_2O/SiO_2$=30${\sim}$35, $Na_2O/SiO_2$=0.5${\sim}$0.6, and $TPA_2O/Na_2O$=1${\sim}$1.25. In these cases, the crystallinity and yield were more than 95% and 90%, respectively. By comparing IR spectrum of Ga-MFI with those of ZSM-5 and silicalite, it was found that Ga-MFI showed a unique peak at 970 $cm^{-1}$, which may be used to identify Ga-MFI from ZSM-5 and silicalite.

• 한국수소및신에너지학회논문집
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• 제26권3호
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• pp.212-220
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• 2015

The engineering plastic of sulfonated polyether ether ketone (SPEEK) as a polymer matrix has been developed in this lab to replace Nafion, solid polymer electrolytes of perfluorosulfonic acid membrane which has several flaws such as high cost, and limited operational temperature above $80^{\circ}C$. The SPEEK was prepared in the sulfonation reaction of polyether ether ketone (PEEK). The organic-inorganic blended composite membranes were prepared by sol-gel casting method with loading the highly dispersed ceria and cesium-substituted tungstosilicic acid (Cs-TSiA) with cross-linking agent contents of 0.01 mL. In conclusion, CL-SPEEK/Cs-TSiA/ceria 1% membrane showed the optimum results such as 0.1882 S/cm of proton conductivity at $80^{\circ}C$, and 99.61 MPa of tensile strength which were better than Nafion 117 membrane.