• 제목/요약/키워드: rate of release

검색결과 2,203건 처리시간 0.027초

산소 소모법에 의한 액체 연료의 열발생율 평가 (Estimation of heat release rate of liquid fuels by Oxygen consumption technique)

  • 한용식;김명배;최준석
    • 한국화재소방학회논문지
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    • 제12권3호
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    • pp.31-37
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    • 1998
  • 액체연료들의 열발생율이 산소 소모법에 의해 측정되었다. 산소 소모법은 화재 시에 경험되어지 는 대부분의 연료에 대해서 소모된 산소단위 질량당 발생된 열량이 근사적으로 같다는 원리에 기 초하고 있다. 산소농도의 측정에는 상자성 방식의 가스 분석기가 사용되었고, C02 및 CO가스 농 도 측정은 적외선 방식의 분석기에 의해 이루어졌다. 가스 분석기들의 시간지연은 고려하지 않았 다. 배기가스 측정방법에 따른 결과들을 비교 검토하였다.

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에너지 방출률에 의한 접착이음의 계면균열에 대한 파괴인성의 평가 (Evaluation of Fracture Toughness by Energy Release Rate for Interface Crack in Adhesively Bonded Joints)

  • 정남용;이명대;강삼근
    • 대한기계학회논문집A
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    • 제24권9호
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    • pp.2174-2183
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    • 2000
  • In this paper, the evaluation method of interfacial fracture toughness to apply the fracture toughness was investigated in adhesively bonded joints of AI/Ced./A1. Four types of adhesively bonded double-cantilever beam(DCB) joints with the interface crack were prepared for the test of interfacial fracture toughness. The experiments to measure the interfacial fracture toughness were performed under the various mixed-mode conditions. The critical energy release rate, Gc, was obtained by the experimental measurement of compliances. From the experimental results, the interfacial fracture toughness for the mixed-mode specimens is well characterized by the energy release rate, and the method of strength evaluation by the interfacial fracture toughness was discussed in adhesively bonded joints.

화재에서의 열발생율 측정 (Measurement of Heat Release Rate in Fires)

  • 한용식;김명배;최준석
    • 연구논문집
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    • 통권29호
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    • pp.49-55
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    • 1999
  • Heat release rate used to characterize the fire is an important factor for determining the fire size, the fire growth and the time for suppression and evacuation. The purpose of present work is to review theoretical backgrounds and to introduce equations for estimation of heat release rate with oxygen consumption method in fires. Our work also shows the experimental results of applications for liquid fuels. The oxygen concentration is measured by the analyzer of paramagnetic type. The analyzers of Infra-Red type are used to measure the concentrations of $CO_2$ and CO gas. Time delays of analyzers are ignored.

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흑연/에폭시 복합재료의 혼합모우드 층간분리 해석 (Analysis of Mixed Mode Delamination in Graphite/Epoxy Composite)

  • 염영진;유희
    • 한국자동차공학회논문집
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    • 제4권4호
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    • pp.171-178
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    • 1996
  • DCB(pure mode I) and CLS(mixed mode) tests were performed to investigate the effect of fracture mode on the interlaminar fracture of composite laminate. Mode I critical strain energy release rate was found to be $133J/m^2$ from the DCB test and total strain energy release rate decreased from $1, 270J/m^2$ as thickness ratio(tl/t) varied from 0.333 to 0.667 from the crease from the CLS test. Crack length had no effect on the total strain energy release rate and load was almost constant during the crack growth of the specimen which had the specific thickness ratio. Crack initiated when the stress of the strap ply reached constant stress $42kgf/mm^2$ which was found to be independent of the thickness ratio.

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균열을 내재한 회전체의 에너지방출률 (The Energy Release Rate for Cracks in a Rotating Continuum)

  • 이태원
    • 대한기계학회논문집
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    • 제19권2호
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    • pp.330-337
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    • 1995
  • For a rotating body with cracks, the new energy release rate equation is presented. The derived equation is different from the other researcher's results. It is a path-independent integral which excluded the derivatives of displacements near the crack tip, thereby improving the numerical accuracy of the energy release rate computation. Moreover, as the equation was derived on basis of the energy principle and non-linear elasticity without assumptions, it can applied to the cracked body with arbitrary shape under elastic-plastic deformation. Several examples are treated to demonstrate the efficiency and accuracy of the proposed method compared to existing methods.

서방형제제 분할처방에 대한 건강보험심사제도의 효과와 장애요인 (Impact and Barriers of the Health Insurance Review on Splitting Extended-Release Formulation Drugs)

  • 장혜민;이의경
    • 한국임상약학회지
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    • 제21권4호
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    • pp.347-352
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    • 2011
  • Health insurance review & Assessment service (HIRA) has enforced cutting the drug costs when physicians prescribe split extended release drugs, starting from December, 2010. The objective of this study is to analyze extended release and enteric coated drugs on pharmaceutical reimbursement list in Korea, and to investigate the impact and barriers of the health insurance review on splitting extended-release formulation drugs. By using the ingredient code, extended release and enteric coated formulations make up 7.8% of all drugs in April, 2011. The most frequently used drugs are agent affecting circulatory and digestive system. From the extended release and enteric coated formulations (n=112), 34.8% (n=39) were not available in other dosage forms. According to questionnaire survey for 169 pharmacists (response rate: 73.8%), the rate of splitting and crushing of extended release and enteric coated drugs decreased. When pharmacists correct physician's prescription errors, the biggest problem was lack of other dosage forms. So it is necessary to develop variety of other dosage forms, and computerized checking system for splitting extended-release drugs. It is also important to inform physicians and patients in regard to the problems of split prescription of extended release and enteric coated drugs.

유사등방성 이종재 접합계면 균열의 에너지해방률에 대한 연구 (A Study on Energy Release Rate for Interface Cracks in Pseudo-isotropic Dissimilar Materials)

  • 이원욱;김진광;조상봉
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 1997년도 추계학술대회 논문집
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    • pp.752-754
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    • 1997
  • The stress intensity factor for an interface crack in dissimilar materials has been obtained by many researchers. But research of the energy release rate for an interface crack in pseudo-isotropic dissimilar materials is insufficient yet. In this paper, the energy release rate for cracks in pseudo-isotropic dissimilar materials was obtained using eigenfunction expansion method and also analyzed numerically using the reciprocal work contour integral method. The results were verified by comparing with other worker's results.

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흰쥐 해마에서 Norepinephrine 유리에 미치는 Protein Kinase C 의 영향 (Effect of Protein Kinase C on Norepinephrine Release in the Rat Hippocampus)

  • 김도경;이영수;최봉규
    • 대한약리학회지
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    • 제31권2호
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    • pp.145-152
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    • 1995
  • The effects and interactions of $4{\beta}-phorbol$ 12,13-dibutyrate(PDB) and polymyxin B(PMB) with adenosine on the electrically-evoked norepinephrine (NE) release were studied in the rat hippocampus. Slices from the rat hippocampus were equilibrated with $^3H-noradrenaline$ and the release of the labelled product, $^3H-NE$, which evoked by electrical stimulation$(3\;Hz,\;2\;ms,\;5\;VCm^{-1},\;rectangular\;pulses)$ was measured. PDB$(0.3{\sim}10\;{\mu}M)$, a selective protein kinase C(PKC) activator, increased the evoked NE release in a dose related fashion while increasing the basal rate of release. And the effects of $1\;{\mu}M$ PDB were significantly inhibited by $0.3\;{\mu}M$ tetrodotoxin(TTX) pretreatment or $Ca^{++}-free$ medium. $PMB(0.03{\sim}1\;mg)$, a specific PKC inhibitor, decreased the NE release in a dose dependent manner while increasing the basal rate of release. Adenosine $(1{\sim}10\;{\mu}M)$ decreased the NE release without changing the basal rate of release, and this effect was significantly inhibited by 8-cyclopentyl-1,3-dipropylxanthine$(2\;{\mu}M)$, a selective $A_1-receptor$ antagonist, treatment. Also, adenosine effects were significantly inhibited by PDB-and PMB-pretreatment. These results suggest that the PKC plays a role in the NE release in the rat hippocampus and might be participated in a post-receptor mechanism of the $A_1-adenosine$ receptor.

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Preparation of Substained-Release Microspheres of Phenylpropanolamine HCI and Their Release Characteristics

  • Kim, Chong-Kook;Lee, Kyung-Mi;Hwang, Sung-Joo;Yoon, Yong-Sang
    • Archives of Pharmacal Research
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    • 제13권4호
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    • pp.293-297
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    • 1990
  • Sustained release microspheres containing phenylpropanolamine HCI (PPA) were prepared with acrylic polymer (Eudragit RL/RS) sand hydroxypropylmethylcellulose phthalate (HPMCP) using a emulsion-solvent evaporation method. Magnesium strate was used a smoothing agent for preparation of microspheres. The microspheres obtained were very spherical and free-flowing particles. Scanning electron microscopy showed that microspheres have a smooth surface and a sponage-like internal structure. The dissolution rate of PPA from the microspheres was dependent on the pH of dissolution media. PPA showed faster relase in hP 1. 2 solution than in pH 7.4 solution due to the solubility of PPA. Therefore we prepared new microspheres containing 5% (w/v) HPMCP in order to control the release of PPA. The release rate of PPA from these new microspheres was similar in pH 1.2 and pH 7.4 solution.

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