• Title/Summary/Keyword: fast-release

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Effects of $\alpha$-Adrenoceptor Antagonists on Phenylephrine-induced Contraction in the Endothelium-denuded Rat Aorta (내피세포를 제거한 흰쥐 대동맥에서 Phenylephrine이 일으킨 수축반응에 대한 $\alpha$-수용체 길항제의 영향)

  • 홍승철;강맹희;박상일;박미선;최수경;정준기;서석수
    • YAKHAK HOEJI
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    • v.35 no.5
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    • pp.416-426
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    • 1991
  • The effects of an irreversible or a reversible $\alpha_1$-adrenoceptor antagonist (dibenamine or prazosin) on $\alpha_1$-adrenoceptor-mediated vasoconstrictions were studied in the endothelium-denuded rat aorta. In these experiments, the mobilization of intracelluier calcium and translocation of extracellular calcium were also studied. To exclude the modulation of endothelium releasing EDRF and EDCF, the endothelium was removed in all rat aortas. Contraction induced by phenylephrine (a full $\alpha_1$-adrenoceptor agonist) was separated into a fast phasic component of the response due to the release of intracellular calcium and a slow tonic one due to the influx of extracellular calcium. Pretreatments with increasing doses of reversible $\alpha_1$-adrenoceptor antagonist prazosin, as well as irreversible $\alpha_1$-adrenoceptor antagonist dibenamine, inhibited the phasic component of phenylephrine-induced contraction more effectively than the tonic one. Pretreatment of dibenamine (0.2 $\mu{M}$) or prazosin (10 nM) to the rat aorta abolished phasic response but remained tonic one about 41% and 51%, respectively. These results suggest that as the efficiency of phenylephrine was progressively reduced by pretreatments with increasing doses of an irreversible or a reversible $\alpha_1$-adrenoceptor antagonist (dibenamine or prazosin), the contraction induced by phenylephrine became progressively more dependent on the influx of extracellular calcium.

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AN UPDATE ON THE MOPRA SOUTHERN GALACTIC PLANE CO SURVEY

  • BRAIDING, CATHERINE;BURTON, MICHAEL G.
    • Publications of The Korean Astronomical Society
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    • v.30 no.2
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    • pp.103-105
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    • 2015
  • The 22 m diameter Mopra telescope in Australia is being used to undertake an improved survey of the CO J = 1-0 line at 3mm along the 4th quadrant of the Galaxy, achieving an order of magnitude better spatial and spectral resolution (i.e. 0.6 and 0.1 km/s) than the Dame et al. (2001) survey that is publically available for the Southern Galactic plane. Furthermore, the Mopra CO survey includes the four principal isotopologues of the CO molecule (i.e. $^{12}CO$, $^{13}CO$, $C^{18}O$ and $C^{17}O$). The survey makes use of an 8 GHz-wide spectrometer and a fast mode of on-the-fly mapping developed for the Mopra telescope, where the cycle time has been reduced to just 1/4 of a second. 38 square degrees of the Galaxy, from $l=306-344^{\circ}$, $b=0{\pm}5^{\circ}$ have currently been surveyed, together with additional 9 sq. deg. regions around the Carina complex and the Central Molecular Zone. We present new results from the survey (see also Burton et al., 2013, 2014). The Mopra CO data are being made publically available as they are published; for the latest release see the project website at www.phys.unsw.edu.au/mopraco.

A Study for Reduction of Ignition Peak Pressure of Gas Generator (가스발생기의 점화 초기압력 저감화 연구)

  • Cha, Hong-Seok;Oh, Seok-Jin;Lee, Yeung-Jo
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2010.05a
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    • pp.138-141
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    • 2010
  • A study to reduce the ignition peak pressure of gas generator for the missile launching system was accomplished. The igniter, as the energy release device for igniting the propellant, is aimed at simultaneous ignition of bundled 3-layered propellant grain without unstable burning. In case of our gas generator which must use the double-base propellant with low ignition property, the fast ignition of propellant and reduction of initial peak pressure should be required for the satisfaction of ejection velocity and acceleration condition. By applying MTV ignition charge for the igniter of gas generator, we accomplished all system performance requirements.

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Study on Combustion Characteristics of Single-Cylinder Diesel Engine by Double Injection (이중 분사 적용에 따른 단기통 디젤엔진의 연소특성에 관한 연구)

  • Lee, Jong-Tae;Shin, Dalho;Kim, Hyung Jun;Yun, Chang-Wan;Kim, Jeong-Soo;Park, Suhan
    • Journal of the Korean Society of Combustion
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    • v.22 no.1
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    • pp.1-7
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    • 2017
  • This paper presents an experimental study on the effect of double injection strategies on combustion characteristics in a single-cylinder diesel engine. These studies are applied to the double injection strategies, such as $2^{nd}$ injection timing variations with fixed injection interval (8 degree) and variations of injection pressures with fixed injection timing and intervals. The injection quantity was 7 + 7 mg for double injections, and 14 mg for single injection. When the injection pressure was increased, the ignition delay was shortened, and the ISFC (indicated specific fuel consumption) was increased due to the fast termination of combustion by the shortened energizing duration. In addition, the retardation of injection timings toward TDC (top dead center) caused the reduction of ignition delay and the decrease of ISFC with the decrease of FMEP (friction mean effective pressure).

Studies on Inhibitory Effect of Immediate-Type Allergic Reaction of Mahwang-Shin-Gung-San (麻黃辛芎散의 卽時型 알레르기 反應 抑制 效果에 關한 硏究)

  • Choe, Jeong-Hyeon;Hwang, Chung-Yeon;Kim, Nam-Gwon;Park, Min-Cheol;Kim, Jin-Man;Mun, Sang-Don
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.14 no.2
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    • pp.231-241
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    • 2001
  • Mahwang-Shin-Gung-San has been found inhibiting the mast cell-mediated anaphylactic reaction. This report describes an inhibitory effect of Mahwang-Shin-Gung-San (MSGS) on the immediate-type cutaneous allergic reactions. MSGS has concentration -dependently inhibited the ear swelling response induced by compound 48/80 in mouse by intradermal injection. The mast cells in mouse ear tissue undergone ear-swelling response by compound 48/80 were stained by alcian blue/nuclear fast red. MSGS significantly inhibited the compound 48/80-induced degranulation from mast cells in ear tissue. MSGS concentration-dependently inhibited the histamine release from the rat peritoneal mast cells (RPMC) by compound 48/80. We also studied the effect of MSGS on mast cell-dependent passive cutaneous anaphylaxis (PCA) activated by dinitrophenyl IgE antibody. MSGS showed potent inhibition of PCA by oral administration. These results indicate that MSGS inhibits immediate-type allergic reactions by inhibition of mast cell degranulation in vivo and in vitro.

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Antiallergic and Anti-inflammatory Effects of the Viticis Fructus (만형자의 항알레르기 및 항염증효과)

  • You, Jin-Su;Chae, Byeong Suk;Kim, Dae Keun;Cui, Xun;Park, Jeong-Suk;Lee, Jae Hyeok;Kim, Sang-Hyun;Shin, Tae-Yong
    • Korean Journal of Pharmacognosy
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    • v.44 no.3
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    • pp.286-290
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    • 2013
  • This study was carried out to the determine the effects of the water extract of Viticis Fructus (Verbenaceae, WEVF) on experimental allergic reactions and inflammation. WEVF was anally administered to mice for high and fast absorption. WEVF inhibited compound 48/80-induced systemic anaphylaxis and immunoglobulin E (IgE)-mediated local allergic reaction. Histamine releasing from mast cells was reduced by WEVF, which was mediated by modulation of intracellular calcium. In addition, WEVF decreased the gene expression of pro-inflammatory cytokines in phorbol 12-myristate 13-acetate plus calcium ionophore A23187 (PMACI)-stimulated HMC-1 cells. These findings demonstrate that the WEVF possesses antiallergic and anti-inflammatory activities, which may be mediated by reducing the release of mediators such as histamine from mast cells and weakening the inflammatory action of these mediators.

Numerical Analysis of Chemical Characteristics of Homogeneous CO/H2/NO in Pressurized Oxy-Fuel Combustion (가압순산소 연소 조건에서 균일 CO/H2/NO의 화학적 특성에 관한 해석 연구)

  • KIM, DONGHEE;AHN, HYUNGJUN;HUH, KANG Y.;LEE, YOUNGJAE
    • Journal of Hydrogen and New Energy
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    • v.30 no.4
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    • pp.320-329
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    • 2019
  • This study was performed by the numerical approach to investigate chemical behaviors of homogeneous syngas ($CO/H_2$) with nitric monoxide (NO) in pressurized oxy-fuel conditions. Hydrogen had a dominant effect to the ignition delay time of syngas due to the fast chemistry of its oxidation. Combustion was promoted by NO at the low temperature region. It was by the additional heat release through NO oxidation and production and consumption of major radicals related to the ignition. Two stage ignition behavior was shown in the pressurized condition by the accumulation of $H_2O_2$ produced from $HO_2$ radical. Additional NO oxidation was induced by the pressurized oxy-fuel condition to produce $NO_2$.

Assessing the Potential of Small Modular Reactors (SMRs) in Spent Nuclear Fuel Management: A Review of the Generation IV Reactor Progress

  • Hong June Park;Sun Young Chang;Kyung Su Kim;Pascal Claude Leverd;Joo Hyun Moon;Jong-Il Yun
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.21 no.4
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    • pp.571-576
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    • 2023
  • The initial development plans for the six reactor designs, soon after the release of Generation IV International Forum (GIF) TRM in 2002, were characterized by high ambition [1]. Specifically, the sodium-cooled fast reactor (SFR) and very-high temperature reactor (VHTR) gained significant attention and were expected to reach the validation stage by the 2020s, with commercial viability projected for the 2030s. However, these projections have been unrealized because of various factors. The development of reactor designs by the GIF was supposed to be influenced by events such as the 2008 global financial crisis, 2011 Fukushima accident [2, 3], discovery of extensive shale oil reserves in the United States, and overly ambitious technological targets. Consequently, the momentum for VHTR development reduced significantly. In this context, the aims of this study were to compare and analyze the development progress of the six Gen IV reactor designs over the past 20 years, based on the GIF roadmaps published in 2002 and 2014. The primary focus was to examine the prospects for the reactor designs in relation to spent nuclear fuel burning in conjunction with small modular reactor (SMR), including molten salt reactor (MSR), which is expected to have spent nuclear fuel management potential.

Technology Trends in CXL Memory and Utilization Software (CXL 메모리 및 활용 소프트웨어 기술 동향 )

  • H.Y. Ahn;S.Y. Kim;Y.M. Park;W.J. Han
    • Electronics and Telecommunications Trends
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    • v.39 no.1
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    • pp.62-73
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    • 2024
  • Artificial intelligence relies on data-driven analysis, and the data processing performance strongly depends on factors such as memory capacity, bandwidth, and latency. Fast and large-capacity memory can be achieved by composing numerous high-performance memory units connected via high-performance interconnects, such as Compute Express Link (CXL). CXL is designed to enable efficient communication between central processing units, memory, accelerators, storage, and other computing resources. By adopting CXL, a composable computing architecture can be implemented, enabling flexible server resource configuration using a pool of computing resources. Thus, manufacturers are actively developing hardware and software solutions to support CXL. We present a survey of the latest software for CXL memory utilization and the most recent CXL memory emulation software. The former supports efficient use of CXL memory, and the latter offers a development environment that allows developers to optimize their software for the hardware architecture before commercial release of CXL memory devices. Furthermore, we review key technologies for improving the performance of both the CXL memory pool and CXL-based composable computing architecture along with various use cases.

Quality Changes of Fresh-Cut Tumeric by Packaging Methods during Storage (포장방법에 따른 세절 생울금의 저장 중 품질 변화)

  • Kim, Dong-Hoo;Han, Jin-Soo;Woo, In-Bong;Jung, Jun-Jae;Park, Si-Woo;Heo, Kyung-Chel;Ha, Ju-hyeung;Yoon, Chan-Suk
    • KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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    • v.23 no.3
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    • pp.151-162
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    • 2017
  • The purpose of this study was to investigate the quality change of fresh-cut tumeric (Curcuma Longa Linne) according to packaging method during storage time. The fresh-cut tumeric were packaged in three different methods : degassing valve packaging (DVP), $CO_2$ gas absorber packaging (CAP) and micro-perforated packaging (MPP). After the samples were packaged, they were stored for 15 days at 4 and $23^{\circ}C$ respectively. The following parameters were observed to indicate the quality changes of the samples: weight loss, CIE $L^*a^*b^*$ colour difference, variation of gas composition inside the package, curcumin contents and changes in hardness of fresh-cut tumeric. DVP did not effectively release $CO_2$ gas to the outside. MPP was suitable to release $CO_2$ gas. However, MPP showed very fast browning and erosion, because a large amount of oxygen was introduced through the perforated hole on the film. CAP was most effective packaging method to inhibit browning, to prevent expansion of the packaging by $CO_2$ gas and to minimize weight loss of fresh-cut tumeric.