• Title/Summary/Keyword: A375-S2

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Experimental Study of Steam Reforming Assisted by Catalytic Combustion in Concentric Annular Reactor (촉매연소를 이용한 동심 원관형 반응기 내의 수증기 개질 반응에 관한 실험적 연구)

  • Ghang, Tae-Gyu;Yu, Sang-Seok;Kim, Yong-Mo;Ahn, Kook-Young
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.34 no.4
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    • pp.375-381
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    • 2010
  • In this paper, the heat-transfer characteristics of steam reforming in an annular reactor are presented. Heat is supplied by the catalytic combustion of syn-gas. The thermal behaviors of exothermic and endothermic reactions in a directly coupled concentric-tube packed-bed reactor were investigated experimentally. The gas mixture supplied for catalytic combustion consisted of the off-gas emitted from MCFC anode. Methane in steam at a suitable S/C (steam-to-carbon) ratio was used in the reforming reactions. On the basis of the experimental results, a simple simulation was performed to predict the temperature profile required in the reforming side of the reactor to achieve optimum hydrogen yield. The results of this study may be utilized as reference data in future studies for further development of coupled reactors.

Nursing Students' Self-Leadership, Self-Efficacy, Interpersonal Relation, College Life Satisfaction (간호 대학생의 셀프리더십, 자기효능감, 대인관계, 대학생활 만족)

  • Lee, Yoon Shin;Park, Sung Hee;Kim, Jong Kyung
    • The Journal of the Korea Contents Association
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    • v.14 no.6
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    • pp.229-240
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    • 2014
  • Acquiring professional knowledge and clinical practice of nursing students is a major barrier to campus life and nursing education is needed the programs for considering student's stress and personal characteristics. This study was to understand relation among self-leadership, self-efficacy, interpersonal relationship and college life satisfaction in nursing students. We conducted a survey of 375 students in 4 nursing colleges during the period from March 2nd to 31st. 2014. The study found a positive correlation and significant direct effects between self-leadership, self-efficacy, interpersonal relationship and college life satisfaction and these variables explained 26.8% of college life satisfaction. Therefore, self-leadership of students can improve self-efficacy, interpersonal relationship, furthermore, improve ultimately college life satisfaction. According to this study, to improve college life satisfaction, student's personal characteristics should be considered and education programs for self-leadership, self-efficacy and interpersonal relationship be reflected in curriculum.

Neuroprotective roles of pituitary adenylate cyclase-activating polypeptide in neurodegenerative diseases

  • Lee, Eun Hye;Seo, Su Ryeon
    • BMB Reports
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    • v.47 no.7
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    • pp.369-375
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    • 2014
  • Pituitary adenylate cyclase-activating polypeptide (PACAP) is a pleiotropic bioactive peptide that was first isolated from an ovine hypothalamus in 1989. PACAP belongs to the secretin/glucagon/vasoactive intestinal polypeptide (VIP) superfamily. PACAP is widely distributed in the central and peripheral nervous systems and acts as a neurotransmitter, neuromodulator, and neurotrophic factor via three major receptors (PAC1, VPAC1, and VPAC2). Recent studies have shown a neuroprotective role of PACAP using in vitro and in vivo models. In this review, we briefly summarize the current findings on the neurotrophic and neuroprotective effects of PACAP in different brain injury models, such as cerebral ischemia, Parkinson's disease (PD), and Alzheimer's disease (AD). This review will provide information for the future development of therapeutic strategies in treatment of these neurodegenerative diseases.

The Combined Effects of Power Imbalance and Mutual Dependence on the Relationship between IOS Diffusion and a Firm's Performance Improvement

  • Gee-Woo Bock;Sang Cheol Park;Won Jun Lee;Cheng Zhang;Kyu Min Hwang
    • Asia pacific journal of information systems
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    • v.29 no.2
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    • pp.217-247
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    • 2019
  • This paper draws on the interdependence theory to examine the role of power and mutual dependence on the relationship between internal/external diffusion and performance improvement within a supply chain. The results from a survey of 375 respondents show that two patterns of IOS diffusion - internal diffusion and external diffusion - have different impacts on a firm's performance improvement according to differences in power and mutual dependence between two parties in the supply chain.

Polydextrose and sugar alcohols: their properties and uses in foods (폴리덱스트로스와 당알코올: 그 특성과 식품에의 이용)

  • Han, Jung-Sook;Kim, Go-Eun;Park, Ji-Won;Park, Chong-Jin
    • Food Science and Industry
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    • v.52 no.4
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    • pp.375-386
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    • 2019
  • Carbohydrates play an important role in not only providing the body with calories but also giving taste and texture in foods. Recently, there is a growing interest in low-calorie carbohydrate materials due to obesity and the resulting diseases caused by excessive intake of calories. Polydextrose and sugar alcohols have calories of 2.0 kcal/g and 2.4 kcal/g, respectively. In addition to being a low-calorie material, polydextrose can be widely used as a dietary fiber source, thereby reducing calories and supplementing fiber. Sugar alcohols have sweetness comparable to a table sugar but they are not calculated as a sugar, so it can meet the government's sugar reduction policy. Also, polydextrose and sugar alcohols are not easily decomposed by heat and acid, and thus can be used without being affected by food manufacturing processes.

Development of Interactive 3D Stereoscopic Animated Storybooks (인터렉티브 3D 입체 전자동화 개발)

  • Song, Mi-Young;Lee, Hyeon-Ah;Lee, Ye-Ji;Cho, Hye-Jin;Kim, Da-Jeong;Jo, A-Reum
    • Proceedings of the Korean Society of Computer Information Conference
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    • 2018.07a
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    • pp.373-375
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    • 2018
  • 본 논문은 기존의 2D 전자 동화책과는 달리 유아들에게 보다 창의적이고, 극적표현력을 길러줄 수 있도록 오프라인의 출판 원작동화의 내용과 그림을 안드로이드 기반으로 3D 입체 기술을 접목시킨 인터렉티브 에듀테인먼트로 3D 입체 전자동화를 개발한다. 즉, 동화의 줄거리에 따라 살아 움직이는 장면을 인터렉티브 애니메이션 뿐 만 아니라 좀 더 생생하게 동화를 체험할 수 있는 인터렉티브 3D 입체 전자 동화를 개발한다.

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Effects of Minor Ginsenosides, Ginsenoside Metabolites, and Ginsenoside Epimers on the Growth of Caenorhabditis elegans

  • Lee, Joon-Hee;Ahn, Ji-Yun;Shin, Tae-Joon;Choi, Sun-Hye;Lee, Byung-Hwan;Hwang, Sung-Hee;Kang, Ji-Yeon;Kim, Hyeon-Joong;Park, Chan-Woo;Nah, Seung-Yeol
    • Journal of Ginseng Research
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    • v.35 no.3
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    • pp.375-383
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    • 2011
  • In the previous report, we have demonstrated that ginsenoside Rc, one of major ginsenosides, is a major component for the restoration for normal growth of worms in cholesterol-deprived medium. In the present study, we further investigated the roles of minor ginsenosides, such as ginsenoside $Rh_1$ and $Rh_2$, ginsenoside metabolites such as compound K (CK), protopanaxadiol (PPD), and protopanaxatriol (PPT) and ginsenoside epimers such as 20(R)- and 20(S)-ginsenoside $Rg_3$ in cholesterol-deprived medium. We found that ginsenoside $Rh_1$ almost restored normal growth of worms in cholesterol-deprived medium in F1 generation. However, supplement of ginsenoside $Rh_2$ caused a suppression of worm growths in cholesterol-deprived medium. In addition, CK and PPD also slightly restored normal growth of worms in cholesterol-deprived medium but PPT not. In experiments using ginsenoside epimers, supplement of 20(S)- but not 20(R)-ginsenoside $Rg_3$ in cholesterol-deprived medium also almost restored worm growth. These results indicate that the absence or presence of carbohydrate component at backbone of ginsenoside, the number of carbohydrate attached at carbon-3, and the position of hydroxyl group at carbon-20 of ginsenoside might plays important roles in restoration of worm growth in cholesterol-deprived medium.

Rayleigh-wave Phase Velocities and Spectral Amplitudes Affected by Insertion of an Anomalous Velocity Layer in the Overburden (천부 속도이상층이 레일리파 위상속도 및 수직변위 스펙트럼 진폭에 미치는 영향)

  • Kim, Ki Young;Jung, Jinhoon
    • Geophysics and Geophysical Exploration
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    • v.15 no.4
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    • pp.155-162
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    • 2012
  • The Thomsen-Haskell method was used to determine sensitivities of the Rayleigh-wave phase velocities and spectral amplitude of vertical ground motion to insertion of a single velocity-anomaly layer into overburden underlain by a basement. The reference model comprised a 9-m thick overburden with shear-wave velocity (${\nu}_s$ of 300 m/s above a half-space with ${\nu}_s$ = 1000 m/s. The inserted layer, with a velocity of 150, 225, 375, or 450 m/s and a thickness of 1, 2, or 3 m, was placed at depths increasing from the surface in increments of 1 m. Phase velocities were computed for frequencies of 4 to 30 Hz. For inserted layer models, we placed an anomalous layer with thickness of 1 ~ 3 m, shear-wave velocity of 150 ~ 450 m/s, and at depths of 0 ~ 8 m in the overburden. The frequency range of 8 ~ 20 Hz were the most sensitive to the difference of $C_R$ between the inserted and reference models (${\Delta}C_R$) for h = 1 m and the frequency range got wide as h increased. For all of the models, the spectral amplitudes of the fundamental mode exceeded those of the $1^{st}$-higher mode except at frequencies just above the low-frequency cutoff of the $1^{st}$-higher mode.

Development of Battery-free SAW Integrated Microsensor for Real Time Simultaneous Measurement of Humidity and $CO_2$ component (습도와 $CO_2$ 농도의 실시간 동시감지를 위한 무전원 SAW 기반 집적 센서 개발)

  • Lim, Chun-Bae;Lee, Kee-Keun;Wang, Wen;Yang, Sang-Sik
    • Journal of the Microelectronics and Packaging Society
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    • v.16 no.1
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    • pp.13-19
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    • 2009
  • A 440MHz wireless and passive surface acoustic wave (SAW) based chemical sensor was developed on a $41^{\circ}YX\;LiNbO_3$ piezoelectric substrate for simultaneous measurement of $CO_2$ gas and relative humidity (RH) using a reflective delay line pattern as the sensor element. The reflective delay line is composed of an interdigital transducer (IDT) and several shorted grating reflectors. A Teflon AF 2400 and a hydrophilic $SiO_2$ layer were used as $CO_2$ and water vapor sensitive films. The coupling of mode (COM) modeling was conducted to determine optimal device parameters prior to fabrication. According to simulation results, the device was fabricated and then wirelessly measured using the network analyzer. The measured reflective coefficient $S_{11}$ in the time domain showed high signal/noise (S/N) ratio, small signal attenuation, and few spurious peaks. In the $CO_2$ and humidity testing, high sensitivity ($2^{\circ}/ppm$ for $CO_2$ detection and $7.45^{\circ}/%$RH for humidity sensing), good linearity and repeatability were observed in the $CO_2$ concentration ranges of $75{\sim}375ppm$ and humidity levels of $20{\sim}80%$RH. Temperature and humidity compensations were also investigated during the sensitivity evaluation process.

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Foreign Exchange Rate Uncertainty in Korea

  • Lee, Seojin
    • East Asian Economic Review
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    • v.24 no.2
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    • pp.165-184
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    • 2020
  • Applying Ismailov and Rossi (2018), I newly construct the Korea FX uncertainty based on the density distribution of historical forecast errors. This uncertainty index properly captures the rare but significant events in the Korean currency market and provides information distinct from other uncertainty measures in recent studies. I show that 1) FX uncertainty arising from unexpected depreciation has a stronger impact on Korea-U.S. exchange rates and that 2) macro variables, such as capital flows or interest rate differentials, have predictive ability regarding Korea FX uncertainty for short horizons. These findings enable us to predict the events of sudden currency crashes and understand the Korea-U.S. exchange rate dynamics.