• 대한환경공학회지
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• 제30권10호
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• pp.984-991
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• 2008

본 연구에서는 다공성 포화매질내에서 페놀의 제거를 위해 효소 중합반응의 적용성을 조사하였다. 페놀로 오염된 지하수의 모의실험으로 실험실 규모의 모래 충진 칼럼(ID: 4.1 cm, 충진높이: 12 cm)에 HRP와 과산화수소수를 주입하여 페놀 제거율 및 고분자 생성율에 대한 효소량(0$\sim$2 AU/mL), 이온강도(5$\sim$100 mM), pH(5$\sim$9)의 영향을 평가하였다. 페놀의 제거율은 효소량 2.0 AU/mL, 이온강도 20 mM, pH 7에서 각각 유입농도의 90% 이상을 유지하였다. 유입페놀은 다공성 매질에 축적되는 불용성 고분자와 유출되는 용해성 고분자들로 변환되었다. 최대 약 8%의 공극부피가 고분자화 반응으로부터 생산된 불용성 고분자에 의해 감소되었다.

• 생명과학회지
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• 제12권5호
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• pp.570-576
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• 2002

천일염에서 분리된 고호염성균인 Hainrcular sp. EH-1 으로부터 amylase 생성을 위한 배양조건을 검토하여 최적조건을 설정하였다. 그 결과는 다음과 같다. 아밀라아제 생산을 위한 배양 조건은 4$0^{\circ}C$, pH 7.5이었으며, 최적 생육배지를 soluble starch 1.5%, yeast extract 1.0%, MgSO$_4$7$H_2O$ 2.0%, KCI 0.1%, NaCl 25%로 조성하여 500 $m\ell$ 삼각 플라스크에 100 $m\ell$ 씩 분주하여 110 rpm/min으로 진탕 배양시켰다. 생육과 효소활성은 9일 배양 후 최대치를 나타내어서, 균의 생육정도와 효소생산 사이에서 증식연관형을 나타내었다.

• 한국재료학회지
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• 제12권7호
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• pp.545-549
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• 2002

Potassium-Calcium-Phosphate glasses in range $XCaO\cdot(50-X)K_2O$ \cdot $50P_2$$O^{5}$were investigated. Glass transition temperature(Tg) of prepared glasses were below $520^{\circ}C$, thermal expansion coefficient from $270.3$\times$10^{7}$ to $604.5$\times$10^{7}$/$^{\circ}C$. The structure of XCaO.(50-X)$K_2$O\cdot$50P_2$$O^{5}$ glasses were examined by FT-IR spectroscopy indirectly. As CaO was increased, Ts, Tg, P-O-P bonding strength and chemical durability were increased. Glass surface change was observed with increasing dissolution time using bulk specimen, weight loss and pH change were measured as function of the dissolution time.

• 한국세라믹학회지
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• 제39권11호
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• pp.1017-1022
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• 2002

$(Ba_{1-x}Ca_x)(Ti_{1-y}Zr_y)O_3(BCTZ)$ powders for the Ni-electrode Multilayer Ceramic Capacitor(MLCC) were synthesized via hydrothermal treatment using mixed aqueous solutions of $BaCl_2{\cdot}2H_2O,\Ca(NO_3)2{\cdot}4H_2O,\ ZrOCl_2{\cdot}8H_2O$ and $TiCl_4$. Two component and three component systems were also extensively studied for basic data. BT, CT and BZ powders were crystalline but CZ was determined to be amorphous under the same synthetic condition. In BTZ system, Zr and Ti were completely soluble and Ca would be substituted for Ba up to ∼6 mol% in BCT. The submicron-sized $(Ba_{0.95}Ca_{0.05})(Ti_{0.80}Zr_{0.20})O_3$ powder of the target composition was successfully synthesized at $150{\circ}$ for 12h.

• 한국식품영양과학회지
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• 제29권1호
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• pp.41-48
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• 2000

김치 시료로부터 자동산화되지 않으며 열 및 중성 pH에서 안정한 AA 유도체인 AA-2G를 생산할 수 있는 당전이활성을 가진 CGTase 생산균주를 분리하였고, 분리균주의 형태학적, 배양학적, 생리학적 성질 및 16s-rDNA sequences를 조사한 결과 그람 양서의 간균으로 호기성이며 내생포자를 형성하는 전형적인 중온성 Bacillus sp. JK-43으로 동정되었다. Bacillus sp. JK-43의 CGTase는 AA-2G 뿐만 아니라 AA-6G로 추정되는 물질을 함께 생산하였으며, 효소 최적생산조건은 1.0% soluble starch, 1.0% yeast extract, 1.0% $Na_2CO_3\;0.1%\;K_2HPO_4,\;그리고\;0.02%\;MgSO_4{\cdot}7H_2O$가 함유된 배지에서 pH 7.0, $37^{\circ}C$에서 26시간 동안 진탕배양하였을 때였다. 각종 당공여채에 따른 Bacillus sp. JK-43의 AA-2G 생산성을 조사한 결과 ${\beta}-CD$에서 가장 높은 AA-2G 생산성을 보였으며, 식혜제도페액인 엿기름 및 밥당화액에서도 비교적 높은 AA-2G 생산성을 보였다. 또한 여러 가지 당수용체에 대한 JK-43의 CGTase의 당전이 반응을 검토한 결과 sucrose, mannitol 및 inositol에서 높은 당전이 수율인 70~90%를 나타내었다.

• 한국대기환경학회지
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• 제11권3호
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• pp.245-252
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• 1995

Atmospheric aerosols were collected by a High Volume Tape Sampler from March 1992 to December 1993 ar Korean, Cheju, Korea. The water soluble ion concentrations in aerosol were analyzed. The concentrations of cations (N $a^{+}$, $K^{+}$, $Ca^{2+}$, $Mg^{2+}$, N $H_{4}$$^{+}$) were determined by an Inductively Coupled Plazma(ICP) or an Atomic Absorption Spectrometer(AAS), and those of anions (C $l^{[-10]}$ , N $O_{3}$$^{[-10]}$ , S $O_{4}$$^{2-}$) were analayzed by the capillary electrophoresis method. The $Ca^{2+}$, S $O_{4}$$^{2-}$ and N $O_{3}$$^{[-10]}$ concentrations in spring were higher than those in other seasons. The lowest concentrations of these elements were found in summer, largely due to scavenging by frequent rains. Especially the $Ca^{2+}$ concentration on April was three to four times higher than the annual mean concentration. The enrichment factor(E.F.) of each element was calculated. The annual mean E.F. values of the $Ca^{2+}$, $Mg^{2+}$ and C $l^{[-10]}$ in 1992 were the same as those in 1993 except $k^{+}$ and S $O_{4}$$^{2-}$. The correlation formula between all cations and anions for the whole period was Anions = 0.759 * Cations + 0.066.Cations + 0.066.

• 상하수도학회지
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• 제22권6호
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• pp.705-714
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• 2008

Three Mesh Screenning Reactors (MSRs) were operated in three different modes to investigate the effect of the mesh opening size and the filtrate flux on the removal of particulate matters and the production of soluble organic matters. The mesh opening size was $82{\mu}m$ (Mode 1), $61{\mu}m$ (Mode 2) and $38{\mu}m$ (Mode 3), respectively, and each mode has three different filtrate flux; $0.47m^3/m^2/d$, $0.95m^3/m^2/d$ and $1.42m^3/m^2/d$, respectively. TSS removal efficiency of mode 1, 2, and 3 fed with 191 mgTSS/L was 27%, 36%, and 60%, respectively. The SCOD concentration of 91mg/L in influent for the mode 1, 2, and 3 increased to 117 mg/L, 127 mg/L, and 155 mg/L, respectively. For the all MSRs, there was no significant effect of filtrate flux on the removal of particulate matters and the production of soluble organic matters. However, the mesh opening size greatly affected the removal of particulate matters and the production of soluble organic matters in wastewater. Three parallel A2O processes consisting of anaerobic, anoxic and aerobic reactors maintaining mixed liquor suspended solids (MLSS) of 3,000 mg/L were operated to investigate the effectiveness of MSR on the removal efficiencies of the organic matters, nitrogen, and phosphorus; MSR influent was introduced to System 1 (183 mgTSS/L, 324 mgTCOD/L, 87 mgSCOD/L, 45.2 mgTKN/L, and 6.6 mgTP/L) and MSR efluent was introduced to System 2 and 3(72 mgTSS/L, 289 mgTCOD/L, 141 mgSCOD/L, 40.2 mgTKN/L, and 4.2 mgTP/L). HRTs of the anaerobic reactors in systems 1, 2 and 3 were 1 h, 1 h and 0.6 h, respectively and anoxic reactors were 2 h in all systems. HRTs of the aerobic reactors in systems 1, 2 and 3 were 5 h, 3 h and 3 h, respectively. TSS concentration in effluent of both system 2 and 3 is about 8 mg/L and lower than that of system 1 effluent. Despite higher TCOD loading and SCOD loading, both Systems 2 and 3 had a greater TCOD and SCOD removal efficiency at 91% and 92% than System 1 was at 88% and 82%, respectively. The nitrification efficiency for system 2 was greater than observed for System 1 (99% verses 97%). The denitrification efficiency for systems 1, 2 and 3 was 78%, 88% and 87%, respectively. System 2 and 3 showed about 12% higher TN removal efficiency than system 1 (85% verses 73%). The effluent TP concentration for system 2 was less than observed for system 1 and 3.

• 생약학회지
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• 제26권2호
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• pp.154-158
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• 1995

Twentyfive plant crude drugs with traditional reputation were selected for the antithrombotic screening. MeOH (80%) extract of each plant was given (500 mg/Kg, p.o.) to mice 1 hr prior to the thrombotic challenge (1.8 mg collagen plus 180 ug epinephrine/Kg, i.v.). Seven extracts (1, 2, 8, 10, 18, 22 and 23) showed either comparable or better recovery than aspirin (50 mg/Kg, p.o.) from paralysis caused by the pulmonary thrombosis. 1, 2, 8, 10, 18, 22 and 23 were fractionated to $CH_2Cl_2$ soluble (fr I) and $H_2O$ soluble (fr II) fractions and each fraction (100 mg/Kg, p.o.) was also tested. Mice treated with fr I of 2 (Angelica koreana), 10 (Corydalis spp.) or 23 (Schizonepeta tenuifolia) showed higher recovery and lower mortality rates than aspirin (50 mg/Kg, p.o.) treated mice.

• Preventive Nutrition and Food Science
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• 제5권1호
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• pp.32-36
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• 2000

Prickly pear juice(PPJ) extracted from prickly pear fruit (Opuntia ficus-indica)was used as raw material for the production of alcoholic beverages. Prickly pear juice (PPJ) had 0.88 oBrix of soluble solid, pH 3.96 and 0.14% of total acidity. Alcohol fermentation of 25% PPJ including 22 oBrix of sugar and 1$\times$106 of inoculum was suitable for alcohol fermentation indicating the rapid decrease of sugar content. The 22 oBrix of sugar in PPJ (25%)GJ (50%) mixture was changed to 6.5 oBrix after fermentation at 3$0^{\circ}C$ for 7 days. The alcohol content was 9.2% (w/v). PPJ (70%)/GJ (30%) mixture produced alcoholic beverage with 6.9% alcohol content resulting in the gradual decrease of soluble for 7 days. On the other hand, PPJ (50%)/GJ(50%) mixture carried out completely the alcohol fermentation at 22$^{\circ}C$ for 6 days and enhanced the red color of alcoholic beverages.

• Korean Chemical Engineering Research
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• 제43권1호
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• pp.153-160
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• 2005

본 실험은 TNT 오염토양의 효율적 제거를 위한 화학적 처리기술 개발을 목적으로 다양한 Fenton reaction 적용성에 관해 고찰하였다. 기존 Fenton reaction은 낮은 pH 요구성을 가지는 단점이 있고 천연토양은 pH에 대한 buffering capacity를 가지고 있으므로 그 적용성이 미약하였다. 이에 중성 pH에서도 효율적으로 Fenton reaction을 유도할 수 있는 modified Fenton reaction을 본 실험에 적용하였다. 또한, 천연 토양 내 다양한 철광석을 철이온 대신 사용함으로써 철슬러지의 발생의 최소화를 위한 Fenton-like reaction의 적용 가능성에 대하여 검토하여 보았다. 실험결과는 오염토양의 기존 Fenton reaction 제거효율은 약 20시간 후 pH 3에서 93%이며 반면 pH 7에서는 21%임을 보였다. 한편, TNT 오염 수용액 처리에 철이온과 5종의 chelating agent를 투입한 실험에서는 24시간 반응 후 pH 7에서 NTA-Fe의 경우가 87%로 그 효율이 가장 우수하였고 citrate-Fe 46%, EDTA-Fe 71%, oxalate-Fe 64%, acetate-Fe 37%의 각각의 제거효율을 나타내었다. 또한, TNT 오염 수용액 처리에 3종의 철광석으로 Fenton-like reaction을 적용한 경우, pH 3에서 24시간 후 goethite 33%, hematite 40%, magnetite 40%의 처리효율을 보였고, pH 7인 경우 goethite 28%, hematite 34%, magnetite에서는 36%의 처리효율을 보였다. 게다가, 성능이 우수한 chelating agent 3종과 2종의 철광석을 이용한 복합처리 실험에서는 magenetite 경우 pH 7에서 NTA 79%, oxalate 59%, EDTA 14%의 제거효율이 측정되었고, hematite 경우 NTA 73%, oxalate 25% 그리고 EDTA 19%의 처리효율을 얻었다. 결론적으로 철광석과 modified fenton reaction의 복합처리의 경우 처리 기간 등의 운영인자를 확보할 경우 효율적으로 TNT 오염토양에 적용될 수 있을 것으로 기대된다.