• 제목/요약/키워드: Part Release

검색결과 355건 처리시간 0.028초

건축물 외벽화재시 Flame Trajectory 추정을 위한 실험적 연구 (Experimental Study on Flame Trajectory in Building External Walls Fire)

  • 신이철;박계원;정재군
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2016년도 춘계 학술논문 발표대회
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    • pp.79-80
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    • 2016
  • In the event of a fire on the outer walls of an architectural structure, through real scale experiments with the purpose of estimating the Flame Trajectory, the behavior and risks of expanded combustion to an upper architectural compartment of the Fire Plume Ejected from an Opening according to changes in the aspect ratio of the opening were examined. The results showed that the more the heat release rate of the fire source increased, the heat capacity of the Fire Plume Ejected from the Opening also increased, and for the case of heptane when compared with methanol or ethanol, the results showed a trend for a significant amount of unburned gas to remain. The results also showed that the larger the aspect ratio was, the more likely it was for the Flame Trajectory to approach the outer walls and rise up. In each of the experiment conditions, as the flame rose from the lower part of the wall to the upper part of the wall, a steady decrease was shown for the temperature distribution. Also by quantitatively analyzing the amount of unburned gas that remained, a method to estimate the temperature of the Fire Plume Ejected from an Opening for a traverse opening was implemented.

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Preparation and Reconstitution of Core-shell Type Nanoparticles of Poly(ε -caprolactone)/Poly(ethyleneglycol)/Poly(ε -caprolactone) Triblock Copolymers

  • Jeong, Young-Il;Ryu, Jae-Gon;Kim, Young-Hoon;Kim, Sung-Ho
    • Bulletin of the Korean Chemical Society
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    • 제23권6호
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    • pp.872-879
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    • 2002
  • One of the improtant characteristics of core-shell type nanoparticles is the long-term storage and reuse as an aqueous injection solution when required. For this reason, reconstruction of lyophilized core-shell type nanoparticles is considered to be essential . BAB type triblock copolymers differ from AB type diblock copolymers, which contain the A block as a hydrophilic part and the B block as a hydrophobic part. by not being easily redistributed into phosphate-buffered saline (PBS, pH 7.4, 0.1 M). Therefore, lyophilized core-shell type nanoparticles of CEC triblock copolymer were reconstituted using a somication process with a bar-type sonicator in combination with a freezing-thawing process. Soncation for 30s only resuspended CEC nanoparticles in PBS; their particle size distribution showed a monomodal pattern with narrow size distribution. The bimodal size distribution pattern and the aggregates were reduced by further sonication for 120 s but these nanoparticles showed a wide size distribution. The initial burst of drug release was increased by reconstitution process. The reconstitution of CEC core-shell type nanoparticles by freezing-thawing resulted in trimodal distribution pattern and formed aggregates, although freezing-thawing process was easier than sonication . Drug release form CEC nanoparticles prepared by freezing-thawing was slower than from the original dialysis solution. Although core-shell typenanoparticles of CEC triblock copolymers were not easily performed. Cytotoxicity testing of core-shell type nanoparticles of CEC-2 triblock copolymers containing clonazepam (CNZ) was performed using L929 cells. Cytotoxicity of CNZ was decreased by incorporation into nanoparticles.

Norfloxacin Release from Polymeric Micelle of Poly($\gamma$-benzyl L-glutamate)/Poly(ethylene oxide)/Poly($\gamma$-benzyl L-glutamate)/ Block Copolymer

  • 나재운;정영일;조종수
    • Bulletin of the Korean Chemical Society
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    • 제19권9호
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    • pp.962-967
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    • 1998
  • Block copolymers consisting of poly(rbenzyl L-glutamate) (PBLG) as the hydrophobic part and poly(ethylene oxide) (PEO) as the hydrophilic part were synthesized and characterized. Polymeric micelles of the block copolymers (abbreviated GEG) were prepared by a dialysis method. The GEG block copolymers were associated in water to form polymeric micelles, and the critical micelle concentration (CMC) values of the block copolymers decreased with increasing PBLG chain length in the block copolymers. Transmission electron microscopy (TEM) observations revealed polymeric micelles of spherical shapes. From dynamic light scattering (DLS) study, sizes of polymeric micelles of GEG-1, GEG-2, and GEG-3 copolymer were 106.5±59.2 nm, 79.4±46.0 nm, and 37.9±13.3 nm, respectively. The drug loading contents of GEG-1, GEG-2 and GEG-3 polymeric micelles were 12.6, 11.9, and 11.0 wt %, respectively. These results indicated that the drugloading contents were dependent on PBLG chain length in the copolymer; the longer the PBLG chain length, the more the drug-loading contents. Release of norfloxacin (NFX) from the nanoparticles was slower in higher loading contents of NFX than in lower loading contents due to the hydrophobic interaction between PBLG core and NFX.

좌금환(左金丸)의 혈관이완과 $K^+$ channel (Role of $K^+$ Channels in the Vasodilation of Jagumhuan)

  • 손창우;이헌재;유가량;신흥묵
    • 동의생리병리학회지
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    • 제19권3호
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    • pp.743-748
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    • 2005
  • This study was performed for the investigation of vasodilatory efficacy and its underlying mechanisms of Jagumhuan(JGH), a herbal remedy. JGH produced completely endothelium-dependent relaxation and relaxed phenylephrine(PE)-precontracted aorta in a concentration dependent manner. The magnitude of relaxation was greater in PE induced contraction than that of KCl, suggesting involvement of $K^+$ channel in the relaxant effect. Both glibenclamide$(10^{-5}M)$, a $K_{ATP}$ channel inhibitor and indometacin, a cyclooxygenase inhibitor, completely prevented this relaxation. The relaxation effects of JGH, involve in part the release of nitric oxide from the endothelium as pretreatment with L-NAME, an NOS inhibitor, and methylene blue, a cGMP inhibitor, attenuated the responses by 62% and 58%, respectively. In addition, nitrite was produced by JGH in human aortic smooth muscle cells and human umbilical vein endothelial cells. The relaxant effect of JGH was also inhibited by 55.41% by tetraethylammonium(TEA; 5mM), a $K_{Ca}$ channel inhibitor. In the absence of extracellular $Ca^{2+}$, pre-incubation of the aortic rings with JGH significantly reduced the contraction by PE, suggesting that the relaxant action of the JGH includes inhibition of $Ca^{2+}$ release from intracellular stores. These results indicate that in rat thoracic aorta, JGH may induce vasodilation through ATP sensitive $K^+$ channel activation by prostacyclin production. However, the relaxant effect of JGH may also mediated in part by NO pathways and $Ca^{2+}$ activated $K^+$ channel.

Surgical anatomy of transversus abdominis muscle for transversus abdominis release

  • Pauline Shanthi;Femina Sam;Jenny Jacob;Beulah Roopavathana S;Suganthy Rabi
    • Anatomy and Cell Biology
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    • 제57권3호
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    • pp.363-369
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    • 2024
  • Transversus abdominis release (TAR) is a myofascial release technique which helps in surgical repair of large ventral abdominal wall defects. In this procedure, the medial margin of muscular part of transversus abdominis (TA) is of great importance. Hence, the authors sought to describe the extent of medial margin of TA muscle. The surgical steps of TAR were performed in 10 formalin-fixed cadavers and distance between medial margin of TA muscle, lateral margin of rectus abdominis, to linea alba at five anatomical levels were documented respectively. The distance between the inferior epigastric vessels and the medial border of TA muscle was also noted. The TA muscle was within the posterior rectus sheath in all cadavers, at the xiphisternum (R, 61.6 mm; L, 58.9 mm), and at midway between xiphisternum and umbilicus (R, 25.4 mm; L, 27.1 mm). The TA muscle exited the posterior rectus sheath between this point and the umbilicus. The mean incongruity at the next three levels were -24.6 mm, -24.9 mm, and -22.9 mm respectively on the right and -21.4 mm, -19.9 mm, and -18.9 mm respectively on the left. The mean distance between the medial border of TA and inferior epigastric vessels was 18.9 mm on the right and 17.2 mm on the left. The muscular part of TA was incorporated within the posterior rectus sheath above the umbilicus, and it completely exited the rectus sheath at the umbilicus. This is contrary to the traditional understanding of posterior rectus sheath formation.

소성 Dolomite를 이용한 화학열펌프내의 축·방열특성 (Characteristic of heat storage/release in chemical heat pump using the calcined dolomite)

  • 홍민혁;이영세;최현국;박영해;김종식
    • 한국산업융합학회 논문집
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    • 제8권4호
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    • pp.191-196
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    • 2005
  • This study was carried out to investigate the heat storage/release characteristics of the thermochemical reaction of the calcined dolomite with the packed bed shape experimental apparatus for development of chemical heat pump system. In the present study, it was found that MgO of the calcined dolomite was not hydrated during the hydration process under the experimental conditions. Therefore, the MgO of the calcined dolomite can be regard as an inert material. As a result, it was found that all of CaO packed kept the reaction temperature of about $510^{\circ}C$ through the entire part of the bed. The dehydration reaction was incurred first at the wall side area as the supplied heat was transferred through the wall side into the packed bed. As a result of the temperature and concentration spread, the reaction was completed at the wall side progressed into the center.

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COSMOS : A Computer Code for the Analysis of LWR $UO_2$ and MOX Fuel Rod

  • Koo, Yang-Hyun;Lee, Byung-Ho;Sohn, Dong-Seong
    • Nuclear Engineering and Technology
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    • 제30권6호
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    • pp.541-554
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    • 1998
  • A computer code COSMOS has been developed based on the CARO-D5 for the thermal analysis of LWR UO$_2$ and MOX fuel rod under steady-state and transient operating conditions. The main purpose of the COSMOS, which considers high turnup characteristics such as thermal conductivity degradation with turnup and rim formation at the outer part of fuel pellet, is to calculate temperature profile across fuel pellet and fission gas release up to high burnup. A new mechanistic fission gas release model developed based on physical processes has been incorporated into the code. In addition, the features of MOX fuel such as change in themo-mechanical properties and the effect of microscopic heterogeneity on fission gas release have been also taken into account so that it can be applied to MOX fuel. Another important feature of the COSMOS is that it can analyze fuel segment refabricated from base irradiated fuel rods in commercial reactors. This feature makes it possible to analyze database obtained from international projects such as the MALDEN and RISO, many of which were collected from refabricated fuel segments. The capacity of the COSMOS has been tested with some number of experimental results obtained from the HALDEN, RISO and FIGARO programs. Comparison with the measured data indicates that, although the COSMOS gives reasonable agreement, the current models need to be improved. This work is being performed using database available from the OECD/NEA.

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탄성 블리스터 액츄에이터를 이용한 일회용 미세유체 주입펌프 (Disposable Microfluidic Infusion Pump using Elastomeric Blister Actuator)

  • 장웅기;김형진;김병희;서영호
    • 한국생산제조학회지
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    • 제22권2호
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    • pp.235-240
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    • 2013
  • This paper presents a disposable microfluidic infusion pump using the restoring force of elastomeric membrane of Polydimethylsiloxane. Microfluidic infusion pump consists of hydraulic resistance control part, elastomeric blister actuator part, drug inlet and outlet. Expanded elastomeric blister actuator continuously pushes liquid in the chamber to outlet. At same time, microchannel diameter near the outlet was controlled by thin elastomeric membrane in hydraulic resistance control part. Eventually flow rate of infused liquid is controlled by air pressure. In experimental study, the amount of the filled liquid in the blister is precisely controlled by the height of the blister. Flow rate of infused liquid could be controlled, that is, controlled release of the drug over time was possible by adjusting hydraulic resistance and restoring pressure with the blister actuator.

긴 게이지길이 광섬유 FBG센서를 이용한 교각상부 거동 혹정 (Displace Measurement of the Top of Bridge Pier Using Long gauge Fiber Optic Sensor)

  • 김기수
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 2006년도 정기 학술대회 논문집
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    • pp.71-76
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    • 2006
  • In this paper, a long gauge Fiber Bragg Grating (FBG) sensor system is described and long gauge FBGs are well, suited for measuring the upper parts of the bridge piers under the extremely severe movement conditions. In the experiments, we used more than 30m long FBG sensors to measure the movement of top part of the bridge piers which are separated from the main bridge by cutting the decks. With the actuator, the deck and girders were pushed and released. We checked the movement of the top of the pier while releasing the pressure of the actuator with the long gauge fiber sensor. In order to measure the movement of the upper part of the pier, the reference point must be outside of the pier. Using the optical fiber sensors, one end of the sensor is attached to the top of the pier and the other end is attached to the bottom of the next pier. The fiber sensors showed good response to the release loading and we could calculate the movement of the top part of the pear.

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호염구세포주와 복강 비만세포에서 유색미 겨 추출물의 알레르기 염증 억제활성 (Inhibitory Activity of Pigmented Rice Bran Extract to the Allergic Inflammation in Basophilic Cell Line and Peritoneal Mast Cells)

  • 최선필;강미영;남석현
    • Applied Biological Chemistry
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    • 제48권4호
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    • pp.315-321
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    • 2005
  • 유색미 겨 추출물이 염증반응에 미치는 효과를 호중구 세포주 및 비만세포가 분비하는 염증매개물질인 histamine과 ${\beta}-hexosaminidase$의 분비 및 염증 cytokine 생성에 대한 억제활성을 측정하여 평가하였다. 호중구 세포주인 RBL-2H3 세포와 rat에서 분리 추출한 복강 비만세포(RPMC, peritoneal mast cell)를 이용하여 histamine과 ${\beta}-hexosaminidase$ 분비에 대한 억제활성을 조사한 결과, 일반미 겨 추출물은 RBL-2H3 세포에서 염증매개물질들의 분비량을 증가시킨 반면, 유색미 겨 추출물은 이들의 분비를 억제하였다(histamine 10.19% 억제, ${\beta}-hexosaminidase$ 110.03% 억제). RPMC에서는 유색미가 histamine과 ${\beta}-hexosaminidase$의 분비를 일반미보다 각각 8배와 3배나 높게 억제하는 것으로 나타났다. 염증관련 cytokine으로서 $IL-1{\beta},\;TNF-{\alpha}$ 및 IL-6의 발현을 RT-PCR로 측정한 결과, 유색미가 일반미 보다 $TNF-{\alpha},\;IL-1{\beta}$ 및 IL-6의 발현을 억제하는 효과가 우수하였다. ELISA를 이용하여 cytokine의 분비량을 측정한 실험에서도 유색미가 일반미보다 $TNF-{\alpha},\;IL-1{\beta}$ 및 IL-6의 분비를 효과적으로 억제하였다. 이상의 결과는 유색미가 염증반응의 원인 물질인 histamine과 ${\beta}-hexosaminidase$의 분비에 대한 억제효과 뿐 아니라, 염증 cytokine의 발현을 저해하는 효과도 일반미보다 우수하다는 사실을 보여주었다.