• Title/Summary/Keyword: forming agent

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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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    • v.1 no.1
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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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    • v.20 no.8
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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.

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

  • 김운석;박성용;조원일;조병원;윤경석
    • Journal of Energy Engineering
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    • v.2 no.3
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    • pp.300-307
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    • 1993
  • To develop high performance nickel-iron secondary battery, the characteristics of charge-discharge reaction of iron electrode were examined by cyclic voltammetry technique, SEM and XRD analysis. The capacity of the test electrodes was determined by the constant current charge-discharge method. It was found that the temperature and concentration of electrolyte were the major determinant factors of electrode capacity, and especially the 1st discharge capacity was increased with the increase of temperature. The effect of fore forming agent on the electrode capacity was negligible. The electrode capacity was above 350 ㎃h/g(36% utility) at 0.25C discharge rate. The stability of electrode was very good, but the activation occurred slowly.

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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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    • v.35 no.3
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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.

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

  • Jeong, Hye-Yun;Kim, Jae-Hyeon;Park, Chang-Won;Lee, Dong-Gwon
    • YAKHAK HOEJI
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    • v.40 no.4
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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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Anti-angiogenic Activity of Ursolic Acid (우르솔릭산의 혈관형성 억제활성)

  • 손경희;이옥희;이열남;정해영;이정준;김규원
    • YAKHAK HOEJI
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    • v.37 no.5
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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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Characterization of Phase Inversion Membrane of Sulfonated Polyetherimide (Sulfonated Polyetherimide Membrane의 특성)

  • 김완주;최남석;최중구;김인철;김종호;탁태문
    • Membrane Journal
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    • v.9 no.1
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    • pp.1-9
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    • 1999
  • Sulfonated polyetherimide having anionic charge and better hydrophilicity than polyetherimide was prepared by reacting polyetherimide with chlorosulfonic acid. To prepare casting solution, from which the membrane having good performance can produce. Polyvinylpyrrolidone as a pore forming agent and volatile weak solvent such as dichloromethane to foml the dense skin layer were added to the sulfonated polyetherimide / N -methyl-2-pyrrolidone solution. Membrane fabricated sulfonated PEl showed better fouling resistance to the protein than those fabricated PEL because of its hydrophilicity. Solute having negative charge was removed effectively with membrane fabricated from the sulfonated PEl because of its the same electron charge.

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Fabrication of Cordierite Honeycomb from Fly Ash

  • Kim, Sung-Jin;Park, Sung-Jin;Bang, Hee-Gon;Park, Sang-Yeup
    • Proceedings of the Korean Powder Metallurgy Institute Conference
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    • 2006.09b
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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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Quality Characteristics of Lightweight Cement Composite using Lightweight Aggregates and Expanded Perlite (경량골재와 팽창펄라이트를 활용한 경량 시멘트복합체의 특성)

  • Kim Duck-Mo;Mun Kyoung-Ju;Soh Yang-Seob
    • Proceedings of the Korea Concrete Institute Conference
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    • 2004.11a
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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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Optimization of Kiln Process Parameters of Low-Temperature Sintering Lightweight Aggregate by Response Surface Analysis (반응표면분석법에 따른 저온소성 경량골재의 킬른공정변수 최적화)

  • Lee, Han-Baek;Seo, Chee-Ho
    • Journal of the Korean Ceramic Society
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    • v.47 no.5
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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.