• 한국재료학회:학술대회논문집
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• 한국재료학회 2010년도 춘계학술발표대회
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• pp.5.1-5.1
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• 2010

One of the most important environmental problems is global warming. Global warming is caused by increase in the amounts of water vapor, methane, carbon dioxide and other gases being released into the atmosphere as a result of the burning of fossil fuels. It has thus become important to reduce fossil fuel use. Environmentally friendly preparation of functional materials has, therefore, attracted much interest for environmental problems. Furthermore, nature mimetic processes are recently been of great interest as environmentally friendly one. There have been many studies on fabrication of various functional nanocrystals. Among various nanocrystal fabrication techniques, flux growth is an environmentally friendly, very convenient process and can produce functional nanocrystals at temperatures below the melting points of the solutes. Furthermore, this technique is suitable for the synthesis of crystals having an enhedral habit. In flux growth, the constituents of the materials to be crystallized are dissolved in a suitable flux (solvent) and crystal growth occurs as the solution becomes critically supersaturated. The supersaturation is attained by cooling the solution, by evaporation of the solvent or by a transport process in which the solute is made to flow from a hotter to a cooler region. Many kinds of oxide nanocrystals have been grown in our laboratory. For example, zero- (e.g., particle), one- (e.g., whisker and tube) and two-dimensional (e.g., sheet) nanocrystals were successfully grown by flux method. Our flux-growth technique has some industrial and ecological merits because the nanocrystal fabrication temperatures are far below their melting points and because the used reagents are less harmless to human being and the environment.

• 자원환경지질
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• 제30권4호
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• pp.327-340
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• 1997

Geochemical characteristics of groundwater, based on chemical analyses of 54 water samples, differ among main rocks of Haman formation, Panyawoel formation, andesite and granite in Daegu area in relation to mineralogical and chemical compositions of the rocks. Concentrations of most solutes are higher in groundwaters of Haman and Panyawoel formations than in those of andesite and granite. High concentrations of $Ca^{2+}$ and $Mg^{2+}$ in groundwaters of the sedimentary rocks result mainly from reaction of $CO_2$-charged water with calcite and weathered feldspars. Average groundwaters in the sedimentary rocks are oversaturated with respect to calcite. Major types of groundwaters are hard $Ca(HCO_3)_2$ and $CaSO_2-CaCl_2$ with hardness of 442 mg/l for Haman formation and 275 mg/l for Panyawoel formation whereas they are soft $Ca(HCO_3)_2$ with hardness 35 mg/I for andesite and 39 mg/I for granite. $Ca(HCO_3)_2$ type results mainly from calcite-dissolution and $CaSO_4-CaCl_2$ from pyrite and partly from domestic pollutants. $CaSO_4-CaCl_2$ type may indicate that groundwaters in the sedimentary rocks are more evolved geochemically than those in the igneous rocks, but it is not obvious because the type might be affected by pyrie dissolution and domestic pollutions. Acid rain is buffered by active calcite in the sedimentary rocks. In the igneous rocks acid rain might react with gibbsite and other forms of $Al(OH)_3$ that might have accumulated as weathering products of primary silicates, and is buffered.

• 한국미생물생명공학회:학술대회논문집
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• 한국미생물생명공학회 2000년도 Proceedings of 2000 KSAM International Symposium and Spring Meeting
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• pp.208-213
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• 2000

Penicillium fellutanum produces a phosphorylated, choline-containing extracellular peptido-polysaccharide, peptidophosphogalactomannan (pPxGM) (8). The $\^$13/C-methyl labeled pPxGM ([methyl-$\^$13/C]pPxGM) was prepared from the cultures supplemented with L-[methyl-$\^$13/C]methionine or [2-$\^$13/C]glycine and was used as a probe to monitor the fate of phosphocholine in this polymer. Addition of purified [methyl-$\^$l3/C]pPxGM to growing cultures in low phosphate medium resulted in the disappearance of [methyl-$\^$13/C]phosphocholine and -N,N'-dimethyl-phosphoethanolamine from the added [methyl-$\^$13/C]pPxGM. Two $\^$l3/C-methyl-enriched cytoplasmic solutes, choline-O-sulfate and glycine betaine, were found in mycelial extracts, suggesting that phosphocholine-containing extracellular pPxGM of P.fellutanum is a precursor of intracellular choline-O-sulfate and glycine betaine and thus of phosphatydilcholine (l0). $\^$13/C-Methyl-labeled cells grown in 3 M NaCl-containing medium showed 2.6- and 22-fold more accumulation of $\^$13/C-methyl labeled choline-O-sulfate and glycine betaine, respectively, originated from the extracellular [$\^$13/C-methyl]pPxGM than those grown without added NaCl. The results suggest that, in addition to glycerol and erythritol, glycine betaine and choline-O-sulfate and thus choline are also osmoprotectants and hence that pPxGM is involved in osmotolerance of this fungus (11). Taken collectively, the $\^$l3/C- and $\^$31/P-NMR analyses of cytosolic solute pools and structural modulation of extracellular pPxGM corresponding to environmental stimuli in P. fellutanum, provided evidence that pPxGM is involved in cellular choline metabolism, osmotolerance, and recycling of metabolites.

• 한국막학회:학술대회논문집
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• 한국막학회 1998년도 춘계 총회 및 학술발표회
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• pp.99-101
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• 1998

1. Introduction : The conventional grafting polymerization technique requires chemically reactive groups on the surface as well as on the polymer chains. For this reason, a series of prefunctionalization steps are necessary for covalent grafting. The surface prefunctionalizational technique for grafting can be used to ionization radiation, UV, plasma, ion beam or chemical initiators. Of these techniques, radiation method is one of the useful methods because of uniform and rapid creation of active radical sites without catalytic contamination in grafted samples. If the diffusion of monomer into polymer is large enough to come to the inside of polymer substrate, a homogeneous and uniform grafting reaction can be carried out throughout the whole polymer substrate. Radiation-induced grafting method may attach specific functional moieties to a polymeric substrate, such as preirradiation and simultaneous irradiation. The former is irradiated at backbone polymer in vacuum or nitrogen gas and air, and then subsequent monomer grafting by trapped or peroxy radicals, while the latter is irradiated at backbone polymer in the presence of the monomer. Therefore, radiation-induced polymerization can be used to modification of the chemical and physical properties of the polymeric materials and has attracted considerable interest because it imparts desirable properties such as blood compatibility. membrane quality, ion excahnge, dyeability, protein adsorption, and immobilization of bioactive materials. Synthesizing biocompatible materials by radiation method such as preirradiation or simultaneous irradiation has often used $\gamma$-rays to graft hydrophilic monomers onto hydrophobic polymer substrates. In this work, in attempt to produce surfaces that show low levels of anti-fouling of bovine serum albumin(BSA) solutions, hydroxyethyl methacrylate(HEMA) was grafted polypropylene membrane surfaces by preirradiation technique. The anti-fouling effect of the polypropylene membrane after grafting was examined by permeation BSA solution.

• KSBB Journal
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• 제9권2호
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• pp.140-146
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• 1994

A. pullulans로부터 polyol 생산 특성을 검토하기 위하여 탄소원, 수분활성의 영향을 검토하였다. 생산된 polyol 중에서 mannitol이 주성분이었고 소량의 glycerol이 함께 생산되었다. 검토된 탄소원 중 sucrose, glucose, fructose, mannose를 단일 탄소원으로 사용하였을 때 mannitol을 생산할 수 있었으며, 20% sucrose 배지에서 polyol 생산량이 최대였고 이때 대당 mannitol의 수율($Yp_{p/s}$)은 0.227이었다 두 종류의 유용한 탄소원인 glucose와 sucrose에 대한 초기기질농도에 대한 $Yp_{p/s}$는 거의 일정한 값을 보여, 일반적인 내삼투성 미생물과는 달리 첨가된 염(NaCl, KCI)의 농도가 증가할수록, 즉 수분활성이 낮은 조건에서는 오히려 mannitol의 생산량이 낮아졌으며, 상대적으로, glycerol의 양은 증가하였다 실험결과를 종합해 볼 때, A. pullulans에 의한 polyol 중, glycer이의 경우는 다른 내삼투성 미생물의 경우와 같이 생산되지만, mannitol의 경우는 sucrose, glucose 등의 유용한 탄소원들의 대사과정 중에 인산화경로(phosphate pathway)과 환원효소작용(enzymatic dehydrogenation)을 통해 생성되는 발효산물 이라는 결론을 얻었다.

• Advances in environmental research
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• 제3권4호
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• pp.307-319
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• 2014

Four chickpea cultivars viz. kabuli (Pusa 1088 and Pusa 1053) and desi (Pusa 1103 and Pusa 547) differing in sensitivity to high temperature conditions were analyzed in earthern pot (30 cm) at different stages of growth and development in the year of 2010 and 2011. Pusa-1053 (kabuli type) showed maximum photosynthetic rate and least by Pusa-547 (desi type), whereas maximum cell membrane thermostability were recorded in Pusa-1103 and minimum in Pusa-1088. Among the treatments, the plants grown under elevated temperature conditions had produced 13.01% more significant data in comparison to plants grown under continuous natural conditions. Stomatal conductance were reduced 44.25% under elevated temperature conditions than natural conditions, whereas 35.56%, when plants grown under initially natural conditions upto 30DAS, then 30-60DAS elevated temperature and finally shifted to natural conditions till harvest. In case of Pusa-1103, stomatal conductance was maximum as compared to rest of 2.7% from Pusa-1053, 8.9% from Pusa-1088, and 10.3% in Pusa-547 throughout the study. Plants grown under continuous elevated temperature conditions had produced 15.30% and 15.32% more significant membrane thermostability index in comparison to continuous natural conditions at vegetative stage and 19.40% and 18.44% at flowering stage, while the better response was recorded at pod formation stage. Pusa-1053 had given 2.8% more membrane thermostability index than Pusa-1088 and Pusa-1103 had given 1.6% more membrane thermostability index than Pusa-547 in the present study. The membrane disruption caused by high temperature may alter water ion and inorganic solutes movement, photosynthesis and respiration. Thus, thermostability of the cell membrane depends on the degree of the electrolyte leakage.

• 한국지하수토양환경학회지:지하수토양환경
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• 제8권1호
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• pp.57-67
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• 2003

지하수 의존도가 큰 농촌지역에서 주로 사용하는 천부지하수는 오염에 민감하므로, 인간활동에 의한 질산성 질소 오염이 생활용수 공급에 큰 문제가 되고 있다. 농경활동과 함께 다양한 규모의 축사가 운영되고 있는 경기도 일죽지역 천부지하수에 대한 질산염 연구결과, 인위적 오염물질 유입이 예상되는 지점이 77%, 먹는물 수질기준을 초과하는 지점이 32～42%로 나타났다. 질소동위원소 분석 결과, 인위적 오염물질 유입이 예상되는 지점은 모두 $\delta^{15}$N-$NO_3$가 5$\textperthousand$ 이상으로 나타났으며, 59%지점이 동물분뇨에서 유래된 질소의 영향을 강하게 받고 있는 것으로 나타났다. 연구지역 천부지하수의 질산성 질소 주 오염 원인은 밀집된 축사로 밝혀졌으며, 운영이 종료된 축사라도 오랫동안 지하수질에 영향을 미치는 것으로 보인다. 축종에 따라 오염원의 화학적 특성이 다른데, 지표수게는 그 영향이 나타나지만, 지하로 유입되는 동안 반응에 의하여 일부 용질이 제거되므로 지하수에서는 오염원 차이에 의한 영향이 나타나지 않았다.

• Journal of Plant Biotechnology
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• 제37권4호
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• pp.425-441
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• 2010

Forages are the backbone of sustainable agriculture. They includes a wide variety of plant species ranging from grasses, such as tall fescue and bermudagrass, to herbaceous legumes, such as alfalfa and white clover. Abiotic stresses, especially salinity, drought, temperature extremes, high photon irradiance, and levels of inorganic solutes, are the limiting factors in the growth and productivity of major cultivated forage crops. Given the great complexity of forage species and the associated difficulties encountered in traditional breeding methods, the potential from molecular breeding in improving forage crops has been recognized. Plant engineering strategies for abiotic stress tolerance largely rely on the gene expression for enzymes involved in pathways leading to the synthesis of functional and structural metabolites, proteins that confer stress tolerance, or proteins in signaling and regulatory pathways. Genetic engineering allows researchers to control timing, tissue-specificity, and expression level for optimal function of the introduced genes. Thus, the use of either a constitutive or stress-inducible promoter may be useful in certain cases. In this review, we summarize the recent progress made towards the development of transgenic forage plants with improved tolerance to abiotic stresses.

• 원예과학기술지
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• 제33권5호
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• pp.625-632
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• 2015

Drought is a severe abiotic stress that affects global crop production. A drought model was created for 'Toyonoka' Fragaria ${\times}$ ananassa, and the effects of drought stress on contents of proline, sugars, and antioxidant enzyme activities were investigated. Strawberry transplants with identical growth were chosen for the experiments and the randomized design included four replications (10 plants per block). The experimental sets differed in the moisture level of the culture medium relative to the range of moisture content as follows: control, 70-85%; mild drought stress, 50-60%; moderate drought stress, 40-50%; and severe drought stress, 30-40%. Drought stress was imposed by limiting irrigation. Plants were sampled and physiological parameters w ere measured on 0, 2, 4, 6, 8, and 10 days after the commencement of droughts tress. The water potential of strawberry leaves decreased in the plants under mild, moderate, and severe stress during the course of the water stress treatment and exhibited a significant difference from the control. Strawberry leaves subjected to drought stress had higher accumulation of proline, sugars, and malondialdehyde, and higher activities of superoxide dismutase, peroxidase, and catalase than leaves of control plants. Malondialdehyde levels increased in parallel with the severity and duration of drought stress. By contrast, antioxidant enzyme activity displayed dynamic responses to drought stress, first increasing and subsequently decreasing as the severity and duration of drought stress increased. These results suggest that strawberry plants respond to drought stress by altering the activities of antioxidant enzymes and the levels of osmotically active metabolites. These biochemical response changes may confer adaptation to drought stress and improve the capacity of plants to withstand water-deficit conditions.

• Journal of the Optical Society of Korea
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• 제19권3호
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• pp.228-236
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• 2015

Fluorescence recovery after photobleaching (FRAP) is a well-established method commonly used to measure the diffusion of fluorescent solutes and biomolecules in living cells or tissues. Here a fiber-optic-based FRAP (f-FRAP) system was developed, and validated using macromolecules in water and agarose gels of different concentrations. We applied f-FRAP to measure the site-specific diffusion of fluorescein (NaFluo) in peritoneal membranes (PMs) on the liver, cecum, and kidney of a living rat during peritoneal dialysis. Diffusion of fluorescein in PM varied in a time-dependent manner according to the type of organ ($D_{PM\;on\;Liver}/D_{NaFluo}=0.199{\pm}0.085$, $D_{PM\;on\;Cecum}/D_{NaFluo}=0.292{\pm}0.151$, $D_{PM\;on\;Kidney}/D_{NaFluo}=0.218{\pm}0.110$). The proposed method allows direct quantitative measurement of the three-dimensional diffusion in local PM in vivo, which was previously inaccessible by peritoneal function test methods such as peritoneal equilibration test (PET) and standardized PM assessment (SPA). f-FRAP is promising for local and dynamic assessments of peritoneal pathophysiology and the mass transport properties of PMs, presumed to be affected by variation of tissue structures over different organs and functional changes of the PM with years of peritoneal dialysis.