• 제목/요약/키워드: silica-gel

검색결과 1,512건 처리시간 0.027초

S.M.I 공법의 내구성 및 차수특성에 관한 실험적 연구 (A Empirical Study on Durability and Waterproofing Characteristic of Space Multi-Injection Grouting Method)

  • 신효희;박민철;박경한;서지원;이송
    • 한국지반환경공학회 논문집
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    • 제14권1호
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    • pp.53-60
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    • 2013
  • 본 연구에서는 대표적인 물유리계 공법인 SGR 공법과 SMI 공법을 실내시험으로 공학적 특성을 비교한 것으로, 각 조건별 양생기간과 양생조건에 따라서 내구성, 강도 및 차수특성, 환경 영향성을 비교 분석하였다. 그 결과 내구성의 경우 SGR 공법은 SMI 공법에 비해 최대 23배 정도 체적변형이 발생하였고, 환경에 미치는 영향은 두 시료 모두 안전한 것으로 나타났다. 차수특성의 경우 SMI 공법은 최대 24% 정도 감소하였으나 SGR의 경우 체적변형이 급격하게 발생하여 간극이 커져 투수계수가 커지는 경향을 나타냈으며, 강도특성은 SMI 공법이 SGR 공법 보다 호모겔의 경우 약 11.0배, 샌드겔의 경우 약 3.9배 정도 높게 나타났다. 이러한 주원인은 SMI 공법은 SGR 공법 보다 용출현상으로 인한 체적변형이 적게 나타났기 때문으로 판단된다.

실리카겔을 이용한 흡착식 담수화 시스템의 기초연구 (Development of Adsorption Desalination System Utilizing Silica-gel)

  • 현준호;김영민;정진호;이윤준;천원기
    • 한국태양에너지학회:학술대회논문집
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    • 한국태양에너지학회 2011년도 춘계학술발표대회 논문집
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    • pp.204-209
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    • 2011
  • According to the environment report of UN, korea was classified as potable water shortage countries. Approximately 71% of the Earth's surface is covered by ocean. However, it is difficult to use for industry of residential purpose without a certain processing. The development of solar and waste-heat used absorption desalination technology have been examined as a viable option for supplying clean energy. In this study, the modelling of the main devices for solar and waste-heat used and adsorption desalination system was introduced. The design is divided into three parts. First, the evaporator for the vaporization of the top water is designed, and then the reactor for the adsorption and release of the steam is designed, followed by the condenser for the condensation of the fresh water is designed. In addition, new features based on the energy balance are also included to design absorption desalination system. In this basicresearch, One-bed(reactor) adsorption desalination plant that employ a low-temperature solar and waste energy was proposed and experimentally studied. The specific water yield is measured experimentally with respect to the time controlling parameters such as heat source temperatures, coolant temperatures, system switching and half-cycle operational times.

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Antioxidative and anti-inflammatory activities of Phaseolus aureus

  • Hong, In-Taik;Kim, Beom-Jun;Yu, Duck-Cho;Kim, Jung-Haeng;Kim, Jung-Han;Heo, Moon-Young;Lee, Song-Jin;Kim, Hyun-Pyo
    • 대한화장품학회지
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    • 제22권2호
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    • pp.41-51
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    • 1996
  • Phaseolus aureus (mung bean), Leguminosae, has been used as an antidote from the ancient time. Especially, it has been widely used for cleaning face and skin in oriental countries. Although several constituents such as fatty acids, phytoallexin and phaseol derivatives were reported in P. aureus and related species including seedlings, there has been a few report to describe its biological activity. Therefore, in this investigation, the ethanol extract from P. aureus was obtained and its biological activities including the antioxidative and anti-inflammatory activities were studied. The 70% ethanol extract from P. aureus showed dose-dependent antioxidative activity (52.3% inhibition at 4 mg/ml) against lipid peroxidation assay, while the extract did not show the inhibitory activity of superoxide radical formation. The extract also showed the topical anti-inflammatory activity against croton-oil and arachidonic acid induced mouse ear edema test (18-19% inhibition at 7.5 mg/ear) as well as mild inhibitory activity against picryl chloride induced delayed hypersensitivity in mouse. For investigating active principles, vitexin and isovitexin (apigenin C-glycoside) as flavonoids, and adenosine were isolated from the extract using silica gel chromatography. The actual contents of vitexin and isovitexin were found to be 3.7 and 2.4 mg/g extract, respectively. Vitexin and isovitexin showed the antioxidative activity. They showed the topical anti-inflammatory activity, although the activities were not potent compared to the reference compounds. These results suggested that vitexin and isovitexin may be, at least in part, the compounds contributing the antioxidative activity in vitro and the topical anti-inflammatory activity of P. aureus in vivo. All results of present study might be one of the scientific rationale in using mung bean for skin care from the ancient time.

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키토산 올리고당의 보습성과 생리활성에 관한 연구 (Moisturizing Property and Physiological Activity of Chitosan Oligosaccharide)

  • 하병조;이옥섭
    • 대한화장품학회지
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    • 제25권1호
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    • pp.6-22
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    • 1999
  • 천연고분자인 키틴으로부터 저분자 키토산을 얻은 후 이를 아질산을 이용한 분해반응에 의해 세포증식효과 및 상처치유효과 등의 생리적인 효과가 있는 키토산 올리고당을 합성하였다 이를 위해 아질산을 이용하여 deamination한 후, sodium borohydride로 환원시켜 reducing-end residue들을 alditol unit로 치환하였으며 MBTH시약을 사용하여 반응이 진행하였음을 확인하였다. 얻어진 키토산 올리고 당의 분자량 분포를 HPLC로 확인한 결과 중합도가 2∼6 인 올리고당이 얻어졌음 을 알 수 있었다. 상대습도 43%와 81%에서 측정한 흡습력 실험결과, 글리세린 에 대해 각각 63%, 57%의 흡습력을 보였으며, 상대습도 43%와 실리카겔 분위기 하의 보습력 측정결과, 각각 98%, 91%의 수분잔존률을 나타내었다 키토산 올리고당은 0,000032∼0.01% 농도 범위에서 세포증식효과를 보였으며, 2%와 20%로 처리한 경우 상처치유효과를 나타내었다.

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Ergosterol Peroxide from Flowers of Erigeron annuus L.as an Anti-Atherosclerosis Agent

  • Kim, Dong-Hyun;Jung, Sung-Je;Chung, In-Sik;Lee, Youn-Hyung;Kim, Dae-Keun;Kim, Sung-Hoon;Kwon, Byoung-Mog;Jeong, Tae-Sook;Park, Mi-Hyun;Seoung, Nak-Sul;Baek, Nam-In
    • Archives of Pharmacal Research
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    • 제28권5호
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    • pp.541-545
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    • 2005
  • Flowers of Erigeron annuus L. were extracted with 80% aqueous MeOH, and the concentrated extract was partitioned with EtOAc, n-BuOH, and H$_2$O. Repeated silica gel and OD S column chromatography of the EtOAc fraction led to the isolation of a sterol, through activityguided fractionation, using ACAT inhibitory activity measurements. From the physico-chemical data, including NMR, MS, and IR, the chemical structure of the compound was determined to be an ergosterol peroxide (1), which has been isolated for the first time from this plant. This compound exhibited hACAT-1 and Lp-PLA$_2$ inhibitory effects, with inhibitory values of 51.6 ${\pm}$ 0.9 and 51 .7 ${\pm}$ 1.2%, at a treatment concentration of 0.23 mM.

Triterpenoids from the Flower of Campsis grandiflora K. Schum. As Human Acyl-CoA: Cholesterol Acyltransferase Inhibitors

  • Kim, Dong-Hyun;Han, Kyung-Min;Chung, In-Sik;Kim, Dae-Keun;Kim, Sung-Hoon;Kwon, Byoung-Mog;Jeong, Tae-Sook;Park, Mi-Hyun;Ahn, Eun-Mi;Baek, Nam-In
    • Archives of Pharmacal Research
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    • 제28권5호
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    • pp.550-556
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    • 2005
  • The flower of Campsis grandiflora K. Schum. Was extracted with 80% aqueous MeOH, and the concentrated extract was partitioned with EtOAc, n-BuOH and H$_2$O. From the EtO Ac fraction, seven triterpenoids were isolated through the repeated silica gel, ODS column chromatographies and preparative HPLC. From the result of physico- chemical data including NMR, MS and IR, the chemical structures of the compounds were determined as 3${\beta}$-hydroxyolean-12-en-28-oic acid (oleanolic acid, 1), 3${\beta}$-hydroxyurs-12-en-28-oic acid (ursolic acid, 2), 3${\beta}$-hydroxyurs-12-en-28-al (ursolic aldehyde, 3), 2${\alpha}$,3${\beta}$-dihydroxyolean-12-en-28-oic acid (maslinic acid, 4), 2${\alpha}$,3${\beta}$-dihydroxyurs-12-en-28-oic acid (corosolic acid, 5), 3${\beta}$,23-dihydroxyurs-12- en-28-oic acid (23-hydroxyursolic acid ,6) and 2${\alpha}$,3${\beta}$,23-trihydroxyolean-12-en-28- oic acid (arjunolic acid, 7). These teriterpenoids were isolated for the first time from this plant. Also, compounds 4, 5, 6, and 7 revealed relatively high hACAT-1 inhibitory activity with the value of 46.2${\pm}$1.1, 46.7${\pm}$0.9, 41.5${\pm}$1.3 and 60.8${\pm}$1.1% at the concentration of 100${\mu}$g/mL, respectively.

칡뿌리의 항산화 성분 (Anitoxidative components of pueraria root)

  • 오만진;이가순;손화영;김성렬
    • 농업과학연구
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    • 제17권1호
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    • pp.52-64
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    • 1990
  • 식물체로부터 유용한 천연항산화제를 검색코저 갈근 중의 항산화성분을 추출하여 silica gel column chromagography, TLC, HPLC로 분리동정한 후 가장 항산화능이 강한 성분을 IR 및 GC-MS로 확인하고 항산화성분을 수종의 유지에 첨가하여 그 항산화 효과를 검토하였다. 갈근 분말로부터 4단계의 용매 추출에 의하여 얻어진 추출물의 수율은 2.54%이였고 linoleic acid기질에 대하여 0.1% 첨가하였을 때 ${\delta}$-tocopherol 100 ppm 첨가구와 비슷한 항산화효과를 나타내었으며 갈근 중에 가장 강한 항산화성분은 puerarin으로 확인 동정되었다. 돈지에 대하여 puerarin의 항산화효과는 ${\delta}$-tocopherol 보다 강하였고 ${\delta}$-tocopherol 보다 약하였다. 또한 식용유지에 puerarin을 100 ppm 농도로 첨가하여 $145^{\circ}C$에서 가열처리 하였을 때 산가의 측정에 의한 항산화효과는 대두유에서 가장 낮았고 돈지에서 가장 높았으며 Co.value TBA value, anisidine value의 측정에 의한 항산화효과는 팝유에서 가장 높았으며 대두유, 면실유에서는 거의 인정되지 않았다.

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가시오가피(Acanthopanax senticosus)의 석유에테르 추출물 중 polyacetylene계 물질의 동정 (Identification of the Polyacetylenes extracted from Acanthopanax Senticosus by Petroleum Ether)

  • 양효진;김은미;장규섭
    • 농업과학연구
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    • 제35권1호
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    • pp.11-17
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    • 2008
  • 가시오가피를 실온에서 petroleum ether로 추출한 polyacetylene의 동정하기 위하여 TLC, HPLC, UV spectrum, IR, NMR로 수행하였다. TLC에 전개시킨 결과, polyacetylene 표준품과 동일한 band가 fraction 5에서 확인되었으며, HPLC에서 fraction 5를 분리시킨 결과 retention time이 4.40, 5.36, 6.40분이었다. 이를 UV spectrum에서 확인한 결과, 6.40분의 peak(compound 3)에서 polyacetylenes의 파장인 231.0nm, 239.0nm, 257.0nm을 나타내었다. IR spetrum에서 triple bond $2256cm^{-1}$과 double bond $1654cm^{-1}$의 전형적인 peak를 나타내었으며, $^{13}C$-NMR(400MHz, $CDCl_3$)에서 polyacetylenes 전형적인 64.0, 71.2, 74.2, 80.2ppm은 2개의 triple bond에 의한 peak와 121.89, 133.0ppm에서 internal double bond로 결합된 2개의 peak를 확인 할 수 있었다.

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SiO2 나노 입자로 코팅된 형광체 분말을 이용한 Gd2O3 : (Li, Eu) 필름 제조 (Synthesis of Gd2O3 : (Li, Eu) Films using Phosphor Powders Coated with SiO2 Nano Particles)

  • 박중철
    • 대한화학회지
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    • 제47권6호
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    • pp.619-624
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    • 2003
  • 졸겔법을 사용하여 $Gd_{1.9-x}Li_{0.1}Eu_xO_3$(x=0.02, 0.05, 0.08, 0.12) 형광체 분말을 합성하였다. 형광체 입자의 표면을 나노 크기의 $SiO_2$(입자크기${\thickapprox}30 nm$)로 코팅한 후 스핀-코팅법으로 유리 기판에 형광체 막을 제작하였다. 유리의 연화온도인 $700^{\circ}C$ 부근에서 융착 되는 $SiO_2$ 나노 입자들에 의해 $Gd_{1.9-x}Li_{0.1}Eu_xO_3$ 입자들은 유리 기판 표면 위에 강하게 융착 되었다(>9H, 연필 경도계). 본 연구에서 채택한, 형광체 막을 제조하는 간단하고 비용이 저렴한 이 방법은 디스플레이장치의 응용 분야에 적용될 수 있을 것으로 생각한다.

인공(人工) 위액(胃液)에 의한 Sterigmatocystin의 실활물(失活物)에 관한 위생화학적(衛生化學的) 연구(硏究) (Hygienic Studies on Inactive Substances of Sterigmatocystin by Artificial Gastric Juice)

  • 김수연;오유진;여신구;장성재
    • 한국균학회지
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    • 제14권1호
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    • pp.61-70
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    • 1986
  • Sterigmatocystin bears a close structural relationship to aflatoxin $B_1$ and is a carcinogenic compound that has been shown to affect various species of experimental animals. Reaction and toxicity of sterigmatocystin in the artificial gastric juice were investigated. Sterigmatocystin was degraded in artificial gastric juice and extracted by the method of A.O.A.C. After cleaned up by silica gel column chromatography, this substance was detected and characterized by thin layer chromatography, UV, IR and mass spectra. It showed $R{\mathcal{f}}$ 0.4 and brick-red color by TLC. Especially, in the mass spectrum of it, fragment peak at m/e 327 was due to the loss of the $-CH_3$ and $-H_2O$, fragment peak at m/e 341 was due to the loss of the $H_2O$ and $-H^+$, and fragment peak at m/e 239 was due to the loss of the 2-chloro-tetrahydrofuran and methyl group from the parent molecule. Therefore, a degraded substance of sterigmatocystin reacted in artificial gastric juice (Sub. K) was estimated with additional formation of hydrochloric acid. In four-day-old chicken embryos, the mean lethal dose $(LD_{50})$ was $140\;{\mu}g/egg$, and 90 to 100% of the embryos were killed with 1 mg/egg. This $LD_{50}$ $140\;{\mu}g/egg$ compared with an $LD_{50}$ $14.69\;{\mu}g/egg$ for sterigmatocystin (acute toxicity) showed the substance to be much less toxic than sterigmatocystin.

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