• 제목/요약/키워드: forming agent

검색결과 259건 처리시간 0.026초

Autoignition of Urethane Foam to be Used as the Insulator of the Household Refrigerator

  • Choi, Jae Wook;Mok, Yun Soo
    • International Journal of Safety
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    • 제1권1호
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    • pp.47-51
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    • 2002
  • This study was performed by measuring the minimum ignition temperature of polyurethane form recovered from the recycling process of the end-of-life home appliances. The critical ignition temperature of polyurethane form was lower as the size of the sample vessel was increased, and that of polyurethane form using cyclopentane as the forming agent was relatively lower than the polyurethane form using CFC and the combustion of cyclopentane-polyurethane form occurred fiercely. It is considered that the recycling process of end-of-life home appliances using cyclopentane-polyurethane form as the insulator would require a special fire and dust explosion prevention measures since there exists a high potential hazard of fire and dust explosion during crushing and storage processes.

Growth Inhibition of Microcystis aeruginosa by a Glycolipid-Type Compound from Bacillus subtilis C1

  • Kim, Hee-Sik;Ahn, Chi-Yong;Joung, Seung-Hyun;Ahn, Jong-Seog;Oh, Hee-Mock
    • Journal of Microbiology and Biotechnology
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    • 제20권8호
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    • pp.1240-1242
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    • 2010
  • We attempted to identify the compound responsible for the growth inhibition of Microcystis aeruginosa occurring when a culture broth of Bacillus subtilis C1 was added to the medium. The active compound was purified from B. subtilis C1 culture broth by adsorption chromatography and HPLC, and was identified as a type of glycolipid based on $^1H$ NMR and MS analyses. The purified active compound completely inhibited the growth of M. aeruginosa at a concentration of 10 ${\mu}g/ml$. This is the first report of a glycolipid produced by a Bacillus strain that has potential as an agent for the selective control of bloom-forming M. aeruginosa.

니켈/철 축전지의 철전극에 관한 연구(II) (A Study on Iron Electrode of Ni/Fe Battery(II))

  • 김운석;박성용;조원일;조병원;윤경석
    • 에너지공학
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    • 제2권3호
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    • pp.300-307
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    • 1993
  • 고성능 니켈-철 축전지를 개발하기 위하여 철전극에 대한 충방전 반응 특성을 전위주사법, SEM, XRD분석으로 조사하였으며, 또한 전극용량을 정전류 충방전 시험법으로 조사하였다. 전해질 온도 및 농도가 전극용량에 크게 영향을 미쳤으며, 특히 온도가 상승함에 따라 1차 방전용량이 증가하였다. 증공제는 전극용량에 거의 영향을 미치지 못하였다. 전극용량은 방전율 0.25C에서 350㎃h/g (이용율 36%) 이상으로 나타났고, 전극의 안정성도 양호하게 나타났으나 활성화가 느리게 일어났다.

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A Novel Drug Delivery System Design for Meloxicam

  • Kim, Hyun-Jo;Lee, Il-Kyu
    • Journal of Pharmaceutical Investigation
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    • 제35권3호
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    • pp.151-155
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    • 2005
  • A drug delivery system(DDS) for practically insoluble meloxicam was developed and evaluated by dissolution study. A novel DDS is two layered system, where the first layer is consisted of gas-forming agent for an immediate release and the second layer is composed of metolose SR(HPMC) for sustained release. This bilayered tablets were manufactured by using manual single punch machine. The results of dissolution study showed an initial burst release followed by sustained release for the experimental period time. From a pharmaceutical point of view, the designed DDS for meloxicam would be informative system in terms of poorly soluble analgesic medicines.

$^{32}P$-Postlabelling 방법을 이용한 미토마이신 C에 의하여 형성된 DNA adduct의 검출 (Detection of DNA Adduct Formed by Mitomycin C by $^{32}P$-Postlabelling)

  • 정혜윤;김재현;박창원;이동권
    • 약학회지
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    • 제40권4호
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    • pp.442-448
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    • 1996
  • Mitomycin C(MMC) has been used as an anticancer drug and behaves as an alkylating agent forming covalent cross-link between complementary strands of double strand DNA. The purpose of this research was to determine number of DNA adducts, formed in vivo by Mitomycin C, in mouse organs. DNAs from liver, lung, brain and pancreas were isolated and used for $^{32}P$-postlabelling. The labeled nucleotides were separated by 2D-TLC and subjected to autoradiography. Numbers of MMC-DNA adducts were 9,9,5,4 in liver, pancreas, lung and brain, respectively.

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우르솔릭산의 혈관형성 억제활성 (Anti-angiogenic Activity of Ursolic Acid)

  • 손경희;이옥희;이열남;정해영;이정준;김규원
    • 약학회지
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    • 제37권5호
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    • pp.532-537
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    • 1993
  • Angiogenesis refers to the formation of new capillary blood vessels, or neovascularization occurring under various physical conditions, such as development of the embryo, formation of corpus luteum, wound healing and pathological conditions including tumor growth and metastases, hemangiomas, diabetic retinopathy, rheumatoid arthritis. There are many evidences that angiogenesis is important for the progressive growth of solid tumors and also permits the shedding of metastatic tumors from the primary site. Thus, treatment of angiogenesis inhibitors might be a novel strategy for tumor growth inhibition. Normal vascular endothelial cells are in a state of differentiation and angiogenic endothelial cells migrate and proliferate, and they subsequently differentiate into vessel-forming quiescent phenotype cells, Therfore, it was speculated that a modifier of cell differentiation could also affect angiogenesis. In order to identify new antiangiogenic factors, the research was conducted to estimate the inhibitory activities of cell differentiation agents by means of chick embryo chorioallantoic membrane(CAM) assay. Hence, we have established the CAM assay for the screening of antiangiogenic agents. Using the CAM assay, we found that ursolic acid, a tumor cell differentiation-inducing agent, showed a markedly inhibitory effect on chick embryonic angiogenesis.

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Sulfonated Polyetherimide Membrane의 특성 (Characterization of Phase Inversion Membrane of Sulfonated Polyetherimide)

  • 김완주;최남석;최중구;김인철;김종호;탁태문
    • 멤브레인
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    • 제9권1호
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    • pp.1-9
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    • 1999
  • Sulfonated Polyetherimide 막은 pore 형성을 위한 polyvinylpyrrolidone 과 저비점 용매 dichloromethane을 첨가하여 투과성능을 최적할 수 있었다. SPEL 막의 친수성은 단백질등의 투과시 모든 pH 범위에서 막 오염을 효과적으로 억제할 수 있으며, 도입된 sulfonic acid group의 음이온성으로 인하여 동일한 전하의 용질을 쉽게 분리할 수 있었다.

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Fabrication of Cordierite Honeycomb from Fly Ash

  • Kim, Sung-Jin;Park, Sung-Jin;Bang, Hee-Gon;Park, Sang-Yeup
    • 한국분말야금학회:학술대회논문집
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    • 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part2
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    • pp.1009-1010
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    • 2006
  • In this study, we attempt to synthesize the cordierite from the reaction of fly-ash, alumina, silicon dioxide, and magnesia powders. For the purpose of air purification, the honeycomb filter with porous cordierite was fabricated from the combination of synthetic cordierite and pore forming agent. Fabricated porous cordierite honeycomb was prepared with high porosity (58%), and good compressive strength (69MPa).

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경량골재와 팽창펄라이트를 활용한 경량 시멘트복합체의 특성 (Quality Characteristics of Lightweight Cement Composite using Lightweight Aggregates and Expanded Perlite)

  • 김득모;문경주;소양섭
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2004년도 추계 학술발표회 제16권2호
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    • pp.533-536
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    • 2004
  • This study aims to manufacture and to evaluate lightweight cement composite using lightweight aggregate and expanded perlite. The expanded perlite and lightweight aggregates were mixed with cement, water, SP(superplasticizer), forming-agent and poly-propylene fiber. The specimens were cured at $20^{\circ}C$ for 24h and then at steam curing of $60^{\circ}C$, RH $100\%$ for 12h. As a result, We could make lightweight cement composite of satisfaction about ALC properties. However it is need to improve the properties of density and water absorption.

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반응표면분석법에 따른 저온소성 경량골재의 킬른공정변수 최적화 (Optimization of Kiln Process Parameters of Low-Temperature Sintering Lightweight Aggregate by Response Surface Analysis)

  • 이한백;서치호
    • 한국세라믹학회지
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    • 제47권5호
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    • pp.365-372
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    • 2010
  • This paper was to evaluate the influence of kiln process parameter(kiln angle, kiln rotating speed) of lightweight aggregate using waste glass and bottom ash with industrial by-products on thermal conductivity, density, water absorption, fracture load and porosity by response surface analysis. In the results of surface plot and contour plot, it has verified that kiln residence time of lightweight aggregate increase as kiln angle and rotating speed decreases. For this reason, pore size and quantity tend to increase by active reaction of forming agent. It seems to be that increase in pore size and quantity have caused decreasing density, fracture load and thermal conductivity, and increasing water absorption. In conclusion, optimization of kiln process parameter on thermal conductivity, density, water absorption, fracture load and porosity by response surface analysis are kiln angle 2.4646%, kiln rotating speed 40.7089 rpm.