• Korean Journal of Agricultural Science
• /
• v.25 no.1
• /
• pp.131-137
• /
• 1998

The cellulase components were partially purified from the culture filtrate of the alkalophilic bacterium Pseudomonas sp. AC-711 and its enzymatic properties were characterized. The specific activity of the purified major enzyme component was 3.5 units/mg protein as carboxymethyl cellulase and the yield was 23% of the total activity of the culture broth. The molecular weight of the component was 46,000 and the Km and Vmax on CMC were determined as $15.4mg\;mL^{-1}$ and $4.17{\mu}moles\;mL^{-1}\;min^{-1}$, respectively. The enzyme was stable at the temperatures below $60^{\circ}C$ and at the pH range of 4.0~11.0, and the optimal temperature and pH were $60^{\circ}C$ and pH 8.0, respectively. The enzyme activity was not significantly affected by the common surfactants (concentration: 0.05%) such as ${\alpha}$-olefin sulfonate, linear alkylbenzene sulfonate, sodium dodecyl sulfonate, hexadecyltrimethylammonium bromide and Tween 80. The enzyme was activated by the metal ions such as $Ca^{2+}$, $Cu^{2+}$, $Co^{2+}$, whereas inhibited by $Hg^{2+}$ and $Zn^{2+}$. The enzyme exhibited relatively high activity toward amorphous CMC as compared with crystalline substrates such as filter paper and avicel.

• Journal of Life Science
• /
• v.8 no.5
• /
• pp.614-621
• /
• 1998

An extracellular inulinase from Penicillium sp. which isolated from soil sample was purified to a single protein th-rough ammonium sulfate fractionation, DEAE-Sephacel ion exchange chromatography and Toyopearl HW 65 F gel filtration. The temperature and pH for the enzyme reaction were around 6$0^{\circ}C$ and 4.0, respectively. The enzyme was stable at 3$0^{\circ}C$-5$0^{\circ}C$ and in the pH range of 4 to 5. $CuCl_2$, $HgCl_2$ and EDTA inhibited the enzyme activity strongly. By contrast, $MnCl_2$ and $CaCl_2$ activated the enzyme activity. The molecular weight of the purified enzyme was esti-mated to be 77,000 dalton by SDS-polyacrylamide gel electrophoresis. The Km values of the enzyme for inulin were calculated to be $2.2\times10^{-3}$M. TLC analysis suggested that purified enzyme is exo-type inulinase. The NH2-terminal amino acid sequences of the purified enzyme was determined to be $NH_2$-X-Glu-Ser-Tyr-Thr-Glu-Lys/Leu-Tyr-Arg-Pro.

• Journal of the Korean GEO-environmental Society
• /
• v.18 no.8
• /
• pp.23-32
• /
• 2017

For exposed slopes, the weathering degree over time has a major effect on the engineering properties of rocks and the slope stability. Rocks are gradually changed by weathering into soil over time, and the resulting physical, chemical and mechanical changes of rocks affect the engineering stability of the slope. However, there are not many ways to objectively evaluate the weathering degree of a slope. In this study, therefore, to investigate the weathering characteristics of rocks, granite, gneiss and shale distributed in the Chungbuk region were sampled by weathering stage and changes in their component minerals and tissues were investigated. Furthermore, artificial weathering was induced using the freezing and thawing test and quantitatively investigated through porosity and absorption rate. In addition, the changes of microcracks due to artificial weathering were evaluated through box fractal dimension ($D_B$). Through mineralogical study the phase change of constituting minerals, the growth of secondary minerals, the development of micro-cracks and the fabric changes due to weathering were observed. The mineralogical, chemical and engineering evaluations of the weathering degree through the experimental results in this study are expected to be useful for analyzing the weathering characteristics and causes by rock type and for proposing a methodology to evaluate the degradation of physical properties comparatively and quantitatively.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.14 no.4
• /
• pp.132-140
• /
• 2006

This investigation into unfermented soybeans, which were left from the soybeans used to make cheongguk-jang, was conducted to find out its availability of the application to the environmental-friendly fertilizers. The test of cultivating lettuce, using 1/5000a Wagner pot, was carried out inside the affiliated farm glasshouse, belonged to University of Chung-Nam National. The results showed that in the category of leaf length, the control and cheongguk-jang soybeans treatment plot had similar outcomes and in the category of the extract of the cheongguk-jang soybeans, it increased by about 26~33%. And in the categories of width and number of leaves it showed that the extract treatment increased by about 9~20%, in compared to the control. Finally, in the category of fresh weight, the results showed that cheongguk-jang soybean and the extract of the cheongguk-jang soybean effectively increased by about 9~27%, and that pig manure compost treatment plot with the extract of the cheongguk-jang soybean also significantly increased by about 26%, compared to the control. Accordingly, the unfermented soybean left in the production of cheongguk-jang and the extract of the cheongguk-jang soybean are considerably appeared to be valuable environmental-friendly fertilizers.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.15 no.4
• /
• pp.32-39
• /
• 1986

A strain of Aspergillus niger CAD 1 which produces considerable amount of beta-galactosidase was selected from extracellular beta-galctaosidase producing fungi isolated from soil. Optimal conditions for the enzyme from Aspergillus niger CAD 1 were the growth in wheat bran supplemented with 0.5% skim milk powder at $30^{\circ}C$ for 72 hrs. The crude enzyme was purified 1,387 fold through DEAE-cellulosc and Sephadex G-100 chromatographr and its recovery was 6.2%, The optimal pH and temperature for the purified enzyme were pH 4.5 ana $45^{\circ}C$, respectively. The Km and Vmax on ONPG were $3.57{\times}10^3M$ and 33.0 unit/mg protein, whereas those on lacose were $83.3{\times}10^3M$and 15.33 unit/mg protein, respectively, The activation energy for the enzyme was 9,900 cal/mol and the enzyme had no metal ion requirement for its activity and stability. The hydrolysis of lactose in skim milk, 4.8% lactose solution and acidic whey were 65%, 70% and 78% after 10 hrs incubation at $45^{\circ}C$, when 182 units of the enzyme were used 50ml of the substrate solutions.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.56 no.2
• /
• pp.113-118
• /
• 2011

This study was aimed to develop blend films by rice by-product (rice-hull and rice-bran) and bio-degradable materials. The rice by-product was firstly prepared from the pulverizing for making fine powder. Bio-degradable materials could be prepared by melting at high temperature. The mixture of the fine powder of rice by-product and melted bio-degradable materials was then blended and cast into films. The obtained films were investigated on their morphology, secondary structures and properties by using SEM, ICP and ASTM, respectively. Mechanical properties and degradability of these films were measured and compared to those of the PE films. Mechanical strength of bio-films was higher than that of PE films, however elongation ratio showed lower percent than that of PE film. In addition, bio-film could be degraded into fragments within 3 months under the field condition of normal upland crop cultivation. Bio-degradable mulching film indicated great potential for agronomic use as a new source of bio-degradable material.

• Economic and Environmental Geology
• /
• v.37 no.2
• /
• pp.185-193
• /
• 2004

A physical model experiment was conducted using a sand and gravel-filled tank model, to investigate the influence on the GPR response of LNAPL vapor phase effects in the unsaturated zone and of residual phase of LNAPL trapped in the saturated zone. Background measurements of GPR were made with only water in the tank using a fluctuating water table model. Gasoline was, then, injected into the bottom of the model tank to simulate a subsurface discharge from a leaking pipe or tank at depth, obtaining GPR data with rising and lowering of water table. Results from the experiment show the GPR sensitivity to the changes in the moisture content in the vadose zone and its effectiveness for monitoring minor fluctuation of the water table. The results also demonstrate a potential of GPR for monitoring possible vapor phase effects of volatile hydrocarbons in the vadose zone as a function of time, and for detecting the effects of residual phase of hydrocarbons in the water saturated system. In addition, the results provide the basis for a strategy that has the potential to successfully detect and delineate residual LNAPL contamination in the water-saturated system at field sites where the conditions are similar to those simulated in the physcial models described herein.

• Korean Journal of Environmental Agriculture
• /
• v.12 no.3
• /
• pp.219-229
• /
• 1993

Effects of paper mill sludge-fertilizers were investigated on the growth performances of tree seedlings under field conditions. Two types of sludge-fertilizers applied were an organic sludge compost and a processed sludge-pellet fertilizer strengthened with several components of organic and inorganic nutrients. Three species of tree seedlings studied were ibota privet(Ligustrum obtusifolium) and yellow poplar(Liriodendron tulipifera) of 1-0 year seedlings and also eastern white pine(Pinus strobus) of 2-2 year seedlings. Nitrogen and phosphorus contents of plot soil treated with sludge compost+sludge-pellet fertilizer+sludge-pellet fertilizer plot were increased to 8 times and 2.6 times as those of control plot, respectively. The growth performances of root collar diameter and seedling height were repeatedly measured up to five times through the growing season and the results were analyzed statistically by analysis of variance of randomized block design and Duncan's multiple range test. The growth performances of dry weight were measured after last fifth measurements.

• Journal of the Korean Chemical Society
• /
• v.38 no.8
• /
• pp.585-589
• /
• 1994

The complexation of cadmium(II) with a well characterized local soil fulvic acid was investigated at different solution pH and fulvic acid concentration using ion selective electrode. The stability constants were determined using a continuous distribution model based on Scatchard Plot; this model takes into consideration the diversitv of cation binding sites on a naturally occurring organic macromolecules even if the nature of the binding sites may not be known. The mean value of $logKi(\mu)$ was found to increase at higher pH(pH 4.0: ${\mu}=3.79{\pm}0.74$ l\;mol^{-1}; pH 6.0: ${\mu}=4.51{\pm}0.78$ l\;mol^{-1}$), and in more dilute fulvic acid concentration([FA] = 50 mgl$^{-1}: {\mu}=4.16{\pm}0.60$ l\;mol^{-1}; [FA]=151 mgl$^{-1}:{\mu}=3.75{\pm}0.5\;l\;mol^{-1}$). The intrinsic constant(logKint) for binding at the strongest site was measured to be around $4.72\;l\;mol^{-1}$ at both pH4.0 and 5.0, but was found to be increased to $6.03\;l\;mol^{-1}$ when pH was 6.0.

• Magazine of the Korean Society of Agricultural Engineers
• /
• v.39 no.1
• /
• pp.75-82
• /
• 1997

건설기술과 산업의 발전에 따라 구조물은 대형화되어 가고, 건설공사의 급격한 팽창으로 골재 수용량이 급증함에 따라 천연골재자원은 점차 부족현상을 면치 못할 처지에 있다. 또한, 무리한 천연골재의 채취는 자연환경을 훼손시킬 뿐만 아니라 자연보호 측면에서도 심각한 공해문제로 대두되고 있어 공급량 부족현상은 날로 심화되고 있다. 이에 세계 몇몇 나라에세는 산업부산물을 이용한 골재 생산으로 공해예방과 폐기물 활용방법을 연구하고 있다. 산업부산물중 플라이 애쉬 생산량은 전 세계적으로 매년 약 2억여톤에 달하고 있으나 이중 일부만 활용되고 있는 실정이다. 이와같은 부산물을 활용하기 위한 일환으로 산업부산물인 PFA(Pulverized Fuel Ash)로 만든 인공경량골재의 년생산량이 영국은 600,000$m^3$, 미국은 300,000$m^3$이며, 매년 증가주세에 있다. 고성능 경량골재 콘크리트는 단위중량의 증가없이 내구성과 강도를 향상시켜 실용화 측면에서 경제적인 효과가 있으며, 플라이 애쉬로 만든 경량골재는 시멘트와의 친화력이나 접착면에서 우수한 것으로 알려져 있다. 본 시험에 사용한 골재는 플라이 애쉬로 만든 인공경량 조골재와 강모래이고, 결합제로서 프틀랜드 시멘트를 사용하였다. 부수적인 결합재로서는 플라이 애쉬, 슬래그, 실리카 흄을 사용하였으며, 고성능 경량골재 콘크리트를 개발코자 재령 28일과 180일의 압축강도가 각각 50MPa와 60MPa가 되도록 배합설계를 하였다. 본 연구에서는 플라이 애쉬, 슬래그, 시리카 흄과 같은 산업부산물을 혼입했을때 경량골재 콘크리트의 압축강도, 휨강도, 동탄성계수, 공극체적, 공극률, 단위중량, 공극 크기별 분포등의 변화를 실험적으로 구명하여 재반 구조용 콘크리트에 활용하기 위한 기초자료를 마련코저 한다.있어 특정한 발육단계의 난포 사망기전을 연구하기 어렵다. 또한 난포는 생체 내에서 다양한 호르몬을 동시에 분비하기 때문에 특정한 난소국부호르몬이 사망기전에 미치는 영향을 조사하기 힘든 점이 있다. 최근 들어 난포체외배양이 다양하게 개발되면서, 이러한 어려운 점을 극복할 수 있게 되었다. 본 논문은 각 발육단계의 난포를 절단해 체외배양하면서, apoptosis DNA 절단 현상을 이용하여 각종 난소국부 호르몬들이 난포발육단계별로 사망기전에 미치는 영향을 요약해 보였다. 난포는 발육하면서 점차 복잡한 호르몬 경로를 생존을 위해 필요로 한다. Prevulatory난포생존에 필요한 난소국부호르몬들은 early antral 단계의 난포에서는 그 미치는 영향이 감소되다가 preantral단계의 난포에서는 영향을 전혀 미치지 못했다. 단지 예외는 cGMP처리로써, 세포내 cGMP수준을 일정하게 유지시켜주는 것이 난포발육단계에 무관하게 생존에 중요한 인자로, 장래 연구는 난포 세포내의 cGMP수준을 조절하는 기작을 규명하는데 있을 것이다.인정되지 않았다. 7. 농지보전 처리구인 배수구와 초생수로구는 비처리구에 비해 낮은 침두 유출량과 낮은 토양유실량을 나타내었다.구보다 14% 절감되는 것으로 나타났다.작용하는 것으로 사료된다.된다.정량 분석한 결과이다. 시편의 조성은 33.6 at% U, 66.4 at% O의 결과를 얻었다. 산화물 핵연료의 표면 관찰 및 정량 분석 시험시 시편 표면을 전도성 물질로 증착시키지 않고, Silver Paint 에 시편을 접착하는 방법으로도 만족한 시험 결과를 얻을 수 있었다.째, 회복기 중에 일어나는 입자들의 유입은 자기폭풍의 지속시간을 연장시키는 경향을 보이며 큰 자기폭풍일수록 현저했다. 주상에서 관측된 이러한 특성은 서브스톰 확장기 활동이 자기폭풍의 발달과 밀접한 관계가