• 방사성폐기물학회지
• /
• 제7권3호
• /
• pp.175-182
• /
• 2009

유동층 비중차 분리기를 이용하여 혼합 폐 이온교환수지에서 폐 양이온수지와 폐 음이온수지로 분리하였으며, 원소분석과 열분석으로 분리가 잘 되었음을 확인하였다. 비중차 분리를 통해 얻은 수백 미크론의 구형 알갱이 형태의 폐 양이온수지와 폐 음이온수지 각각을 볼밀로써 24시간 습식 분쇄하여 적정 입도 이하의 입자가 균일하게 분산된 고농도 슬러리를 얻은 다음, 희석하여 $COD_{cr}$, 농도 25,000ppm의 시료를 준비하였다. 실험실 규모의 소형 초임계수산화(Super Critical Water Oxidation, SCWO) 장치(반응기 용량 : 220 mL)로써 화력발전소에서 발생한 폐 양이온수지와 폐 음이온수지에 대해 최적의 분해조건을 확립한 다음, 파일럿플랜트(반응기 용량 : 24 L)로 scale-up 실험을 수행하였다. 우선 화력발전소의 폐수지로서 파일럿테스트를 실시한 다음, 원자력발전소의 폐수지로써 파일럿테스트를 수행하여 최적의 분해조건을 설정하였다. 실험실 규모의 소형 SCWO 장치와 파일럿플랜트의 설계 및 운전에서 얻은 경험을 바탕으로 원자력발전소 내에 설치 가능한 규모로 상용설비(처리용량 : 150kg/h)를 설계 중에 있다.

• Advanced Composite Materials
• /
• 제16권4호
• /
• pp.269-282
• /
• 2007

Fully biodegradable high strength composites or 'advanced green composites' were fabricated using yearly renewable soy protein based resins and high strength liquid crystalline cellulose fibers. For comparison, E-glass and aramid ($Kevlar^{(R)}$) fiber reinforced composites were also prepared using the same modified soy protein resins. The modification of soy protein included forming an interpenetrating network-like (IPN-like) resin with mechanical properties comparable to commonly used epoxy resins. The IPN-like soy protein based resin was further reinforced using nano-clay and microfibrillated cellulose. Fiber/resin interfacial shear strength was characterized using microbond method. Tensile and flexural properties of the composites were characterized as per ASTM standards. A comparison of the tensile and flexural properties of the high strength composites made using the three fibers is presented. The results suggest that these green composites have excellent mechanical properties and can be considered for use in primary structural applications. Although significant additional research is needed in this area, it is clear that advanced green composites will some day replace today's advanced composites made using petroleum based fibers and resins. At the end of their life, the fully sustainable 'advanced green composites' can be easily disposed of or composted without harming the environment, in fact, helping it.

• Advances in Traditional Medicine
• /
• 제9권1호
• /
• pp.1-13
• /
• 2009

Medicinal herbs are significant source of synthetic and herbal drugs. In the commercial market, medicinal herbs are used as raw drugs, extracts or tinctures. Isolated active constituents are used for applied research. For the last few decades, phytochemistry (study of plants) has been making rapid progress and herbal products are becoming popular. According to Ayurveda, the ancient healing system of India, the classical texts of Ayurveda, Charaka Samhita and Sushruta Samhita were written around 1000 B.C. The Ayurvedic Materia Medica includes 600 medicinal plants along with therapeutics. Herbs like turmeric, fenugreek, ginger, garlic and holy basil are integral part of Ayurvedic formulations. The formulations incorporate single herb or more than two herbs (poly-herbal formulations). Medicinal herb contains multitude of chemical compounds like alkaloids, glycosides, saponins, resins, oleoresins, sesquiterpene, lactones and oils (essential and fixed). Today there is growing interest in chemical composition of plant based medicines. Several bioactive constituents have been isolated and studied for pharmacological activity. R. cordifolia is an important medicinal plant commonly used in the traditional and Ayurvedic system of medicine for treatment of different ailments. This review illustrates its major constituents, pharmacological actions substantiating the claims made about this plant in the traditional system of medicine and its clinical applications.

• 한국식물병리학회지
• /
• 제14권3호
• /
• pp.191-202
• /
• 1998

About 300 actinomycetes were isolated from two forest and one sea-shore soil and tested for inhibitory effects on mycelial growth of six plant pathogenic fungi Magnaporthe grisea, Alternaria mali, Colletotrichum gloeosporioides, Phytophthora capsici, Fusarium oxysporum f. sp. cucumerinum, and Rhizoctonia solani. Among 300 actinomycetes tested, only 16 actinomycetes showed the antifungal activity against the test fungi. Isolate NH 50 was selected for production and purification of antifungal antibiotic substances. Actinomycete isolate NH 50 displayed the broad antifungal spectra against 11 plant pathogenic fungi. To identify actinomycete isolate NH 50, cultural characteristics on various agar media, diaminopimelic acid type, and morphological characteristics by scanning electron microscopy were examined. As a result, actinomycete isolate NH 50 was classified as a rare actinomycete that had LL-DAP type and did not produce spores. After incubation of isolate NH 50 in yeast extract-malt extract-dextrose broth, antifungal compound NH-B1 that inhibited mycelial growth of some plant pathogenic fungi was purified from the methanol eluates of XAD-16 resins by a series of purification procedures, i.e., silica gel flash chromatography, C18 flash chromatography, Sephadex LH-20 column chromatography, silica gel medium pressure liquid chromatography (MPLC), C18 MPLC, and high pressure liquid chromatography (HPLC). UV spectrum and 1HNMR spectrum of antifungal compound NH-B1 dissolved in methanol were examined. The antibiotic NH-B1 showed the major peaks at 230 and 271.2nm. Based on the data of 1H-NMR spectrum, NH-B1 was confirmed to be an extremely complex polymer of sugars called polysaccharides. The antibiotic NH-B1 showed strong antifungal activity against Alternaria solani and Cercospora kikuchi, but weak activity against M. grisea.

• Elastomers and Composites
• /
• 제47권1호
• /
• pp.2-8
• /
• 2012

본 연구에서는 식물성 오일로부터 여러 가지 기능기를 가진 soybean resin(AESO, MAESO)을 제조하였으며, nanoclay를 사용하여 새로운 고기능성 바이오-나노 복합 재료를 개발하였다. 또한 제조된 soybean resin을 바인더로 이용하여 $TiO_2$ 광전극을 제조하고 친환경 염료감응형 태양전지를 개발하다. 제조된 나노복합재료의 형태는 고분자의 삽입에 의해 층간 간격이 증가된 형태와 박리된 형태를 조절하였으며 나노 클레이 함량이 증가됨에 따라 물리적 성질이 증가하였다. 또한 COOH기가 첨가된 MAESO에서 분산도가 향상되었고 초음파 처리에 의해 분산도가 더욱 향상되어 물리적 특성이 현저히 향상되었다. 또한 $TiO_2$를 질산처리 한 후 soybean resin을 바인더로 이용하여 나노 다공성 $TiO_2$ 광전극을 제조하였으며 염료를 흡착시킨 후 염료감응형 태양전지를 제조하였다. AESO와 MAESO를 바인더로 제조한 $TiO_2$ 광전극에서는 향상된 분산성과 표면적 증가로 인해 염료 흡착량이 증가하였다. 이로 인해 높은 전류밀도를 나타내었으며, 첨가된 기능기의 영향으로 $TiO_2$ 계면의 저항이 낮아져 매우 좋은 광전기화학적 특성과 높은 효율을 나타내었다.