• Title/Summary/Keyword: internal barrier

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Design Criteria of the Median Barrier Considering Impulse Measurement (충격량을 고려한 중앙분리대 설계기준에 관한 연구)

  • Park, Je-Jin
    • Journal of Korean Society of Transportation
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    • v.26 no.2
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    • pp.167-176
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    • 2008
  • Although a rate of car accident death is on the decrease, internal rate of median encroachment accident is still high. In order to reduce the median encroachment accident, government use median barriers but there are no exact criteria of them. Particularly, current impulse measurement method has adopted the uniformly operating speed and encroachment angle. At reality, however, there are various conditions depends on driver's characters. In that reason, this study calculates reasonable impulse quantity through encroachment angle and operating speed. It will be necessary to prevent overuse treasury and car accidents.

The Effect of Surface Plasmon on Internal Photoemission Measured on Ag/$TiO_2$ Nanodiodes

  • Lee, Hyosun;Lee, Young Keun;Park, Jeong Young
    • Proceedings of the Korean Vacuum Society Conference
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    • 2013.02a
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    • pp.662-662
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    • 2013
  • Over the last several decades, innovative light-harvesting devices have evolved to achieve high efficiency in solar energy transfer. Research on the mechanisms for plasmon resonance is very desirable to overcome the conventional efficiency limits of photovoltaics. The influence of localized surface plasmon resonance on hot electron flow at a metal-semiconductor interface was observed with a Schottky diode composed of a thin silver layer on $TiO_2$. The photocurrent is generated by absorption of photons when electrons have enough energy to travel over the Schottky barrier and into the titanium oxide conduction band. The correlation between the hot electrons and the surface plasmon is confirmed by matching the range of peaks between the incident photons to current conversion efficiency (IPCE, flux of collected electrons per flux of incident photons) and UV-Vis spectra. The photocurrent measured on Ag/$TiO_2$ exhibited surface plasmon peaks; whereas, in contrast to the Au/$TiO_2$, a continuous Au thin film doesn't exhibit surface plasmon peaks. We modified the thickness and morphology of a continuous Ag layer by electron beam evaporation deposition and heating under gas conditions and found that the morphological change and thickness of the Ag film are key factors in controlling the peak position of light absorption.

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The Antecedents Of Brand Love Toward Natural Products: An Approach of S.O.R Theory

  • NGUYEN, Le Thai Hoa;NGUYEN, Hoang Anh
    • Asian Journal of Business Environment
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    • v.12 no.2
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    • pp.13-28
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    • 2022
  • Purpose: Natural products are becoming gradually popular because of their health - related benefits and consumers' environmental awareness. However, research in this field remains limited, the present study attempts to address this research gap by measuring the influencing levels of the antecedents on natural product brand love. Research design, data and methodology: The study employs S-O-R (Stimulus - Organism - Response) framework together with Innovation Resistance Theory and Dual-Factor Theory to propose the research model, in which health and environmental stimuli influence both of facilitators and inhibitors of internal states or organism, and then shape purchase intention and brand love as consumers' responses. The mixed research method is designed with the application of structural equation model (SEM) to analyze 530 consumers collected by convenience sampling. Results: The results revealed that two chosen stimuli, including health awareness and environmental concern were positively related to both facilitators (natural content and regional products) and inhibitors (image barrier and usage barrier) and these four factors were significantly associated to purchase intention and brand love. Furthermore, purchase intention played the mediating role on the relationship between the four organisms and brand love. Conclusions: The originality of this paper is extend S-O-R theory into natural product context with mediating effects in an emerging economy. The findings make theoretical contribution on consumer behavior and managerial implication.

A Study on the Application of Barrier Free in Library Architecture - Focused on the Case of the Gwangju, Metropolitan City University Library - (도서관 건축에 있어서 베리어프리 적용 현황에 관한 연구 - 광주광역시 대학 도서관 사례를 중심으로 -)

  • Kim, Chae Yi;Kim, Hong Bae
    • Journal of the Korean Institute of Rural Architecture
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    • v.26 no.2
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    • pp.17-25
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    • 2024
  • This study is to use B.F. certification standards to identify the application and differences of B.F. facilities according to various approaches, and to use the analysis results as basic data for the expansion and renovation of new facilities, the National University (Jeonnam University Library), which underwent remodeling before the implementation of the certification system, and the two newly established private universities (Joseon University Library) that were subject to legal application before the implementation of the certification system. First, Chosun University met more B.F. certification standards than Chonnam National University, and mainly intermediary facilities belonged to the best to the best. Second, Chosun University and Chonnam National University's internal facilities met many B.F. certification standards, and Chonnam National University had many areas to improve and found areas to remodel. Third, information facilities at Chonnam National University and Chosun University only had facilities for the hearing impaired, and there were no information facilities for the visually impaired. Facilities for the visually impaired had to be installed, and compared to Chosun University, Chonnam National University fell short of the B.F. certification standard, so there were many areas that needed to be remodeled.

The Simple in Vivo Evaluation Method for Blood-Brain Barrier Permeability of Drugs in Mice (생쥐에 있어서 약물의 혈액-뇌 관문 투과성 평가를 위한 간편한 in vivo 방법)

  • Kang, Young-Sook;Kim, You-Jung
    • Journal of Pharmaceutical Investigation
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    • v.30 no.2
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    • pp.99-105
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    • 2000
  • This study compared the permeability of $[^3H]taurine,\;[^3H]phenylalanine,\;and\;[^3H]oxytocin$ through the blood-brain barrier (BBB) in mice and rats with common carotid artery perfusion (CCAP) method that modified internal carotid artery perfusion (ICAP) method. External carotid artery (ECA) was cannulated with coagulating pterygopalatine artery (PPA) in ICAP method, while CCA was cannulated without coagulating PPA in CCAP method. Also, for evaluation of BBB permeability of drugs in mice and rats, we used intravenous injection technique. The results of CCAP method in mice at a perfusion flow-rate of 2 ml/min, the brian volume of distribution $(V_D)$ of $[^{14}C]sucrose,\;[^3H]taurine,\;[^3H]phenylalanine,\;and\;[^3H]oxytocin$ were similar to the result of ICAP method in rats at perfusion flow rate of 4 ml/min. The area under the plasma concentration-time curve and brain uptake of $[^3H]taurine$ by intravenous injection technique, were $65.5{\pm}9.7%ID^*min/ml\;and\;0.515{\pm}0.093%ID/g$, respectively, in mice, and the corresponding values were $8.00{\pm}0.03%ID^*min/ml\;and\;0.052{\pm}0.003%ID/g$ in rats. But the BBB permeability surface-area product of $[^3H]taurine$ was similar between mice and rats. In conclusion, the CCAP method in mice was simple, fast and comparable to ICAP method in rats for drug permeability through the BBB.

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Evaluation of the Degradation of a 1300℃-class Gas Turbine Blade by a Coating Analysis (1300℃급 가스터빈 1단 블레이드의 코팅분석을 이용한 열화평가)

  • Song, Tae Hoon;Chang, Sung Yong;Kim, Beom Soo;Chang, Jung Chel
    • Korean Journal of Metals and Materials
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    • v.48 no.10
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    • pp.901-906
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    • 2010
  • The first stage blade of a gas turbine was operated under a severe environment which included both $1300^{\circ}C$ hot gas and thermal stress. To obtain high efficiency, a thermal barrier coating (TBC) and an internal cooling system were used to increase the firing temperature. The TBC consists of multi-layer coatings of a ceramic outer layer (top coating) and a metallic inner layer (bond coat) between the ceramic and the substrate. The top and bond coating layer respectively act as a thermal barrier against hot gas and a buffer against the thermal stress caused by the difference in the thermal expansion coefficient between the ceramic and the substrate. Particularly, the bondcoating layer improves the resistance against oxidation and corrosion. An inter-diffusion layer is generated between the bond coat and the substrate due to the exposure at a high temperature and the diffusion phenomenon. A thickness measurement result showed that the bond coat of the suction side was thicker than that of the pressure side. The thickest inter-diffusion zone was noted at SS1 (Suction Side point 1). A chemical composition analysis of the bond coat showed aluminum depletion around the inter-diffusion layer. In this study, we evaluated the properties of the bond coat and the degradation of the coating layer used on a $1300^{\circ}C$-class gas turbine blade. Moreover, the operation temperature of the blade was estimated using the Arrhenius equation and this was compared with the result of a thermal analysis.

Involvement of a Novel Organic Cation Transporter in Paeonol Transport Across the Blood-Brain Barrier

  • Gyawali, Asmita;Krol, Sokhoeurn;Kang, Young-Sook
    • Biomolecules & Therapeutics
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    • v.27 no.3
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    • pp.290-301
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    • 2019
  • Paeonol has neuroprotective function, which could be useful for improving central nervous system disorder. The purpose of this study was to characterize the functional mechanism involved in brain transport of paeonol through blood-brain barrier (BBB). Brain transport of paeonol was characterized by internal carotid artery perfusion (ICAP), carotid artery single injection technique (brain uptake index, BUI) and intravenous (IV) injection technique in vivo. The transport mechanism of paeonol was examined using conditionally immortalized rat brain capillary endothelial cell line (TR-BBB) as an in vitro model of BBB. Brain volume of distribution (VD) of [$^3H$]paeonol in rat brain was about 6-fold higher than that of [$^{14}C$]sucrose, the vascular space marker of BBB. The uptake of [$^3H$]paeonol was concentration-dependent. Brain volume of distribution of paeonol and BUI as in vivo and inhibition of analog as in vitro studies presented significant reduction effect in the presence of unlabeled lipophilic compounds such as paeonol, imperatorin, diphenhydramine, pyrilamine, tramadol and ALC during the uptake of [$^3H$]paeonol. In addition, the uptake significantly decreased and increased at the acidic and alkaline pH in both extracellular and intracellular study, respectively. In the presence of metabolic inhibitor, the uptake reduced significantly but not affected by sodium free or membrane potential disruption. Similarly, paeonol uptake was not affected on OCTN2 or rPMAT siRNA transfection BBB cells. Interestingly. Paeonol is actively transported from the blood to brain across the BBB by a carrier mediated transporter system.

InAs/GaAs 양자점 태양전지에서 AlGaAs Potential Barrier 두께에 따른 Photoreflectance 특성 및 내부 전기장 변화

  • Son, Chang-Won;Ha, Jae-Du;Han, Im-Sik;Kim, Jong-Su;Lee, Sang-Jo;Smith, Ryan;Kim, Yeong-Ho;Kim, Seong-Jun;Lee, Sang-Jun;No, Sam-Gyu;Park, Dong-U;Kim, Jin-Su;Im, Jae-Yeong
    • Proceedings of the Korean Vacuum Society Conference
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    • 2011.08a
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    • pp.306-307
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    • 2011
  • Franz Keldysh Oscillation (FKO)은 p-n 접합 구조의 공핍층(depletion zone)에서 전기장(electric field)에 의해 발생되며, Photoreflectance (PR) spectroscopy를 통하여 관측된다. InAs/GaAs 양자점 태양전지(Quantum Dot Solar Cells, QDSCs)에서 PR 신호에 대한 Fast Fourier Transform (FFT)을 통하여 FKO 주파수들을 관측할 수 있고, 각각의 FKO 주파수들은 태양전지 구조에 대응하는 표면 및 내부전기장(internal electric field) 들로 분류할 수 있다. InAs/GaAs 양자점 태양전지에서 AlGaAs potential barrier의 두께에 따른 내부전기장의 변화를 조사하기 위해, GaAs-matrix에 8주기의 InAs 양자점 층이 삽입된 태양전지를 molecular beam epitaxy (MBE) 방법으로 성장하였다. 양자점의 크기는 2.0 monolayer (ML)이며, 각 양자점 층은 1.6 nm에서 6.0 nm의 AlGaAs potential barrier들로 분리되어 있다. 또한 양자점 층의 위치에 따라 내부전기장 변화를 조사하기 위해, p-i-n 구조에서 양자점 층이 공핍층 내에 위치한 경우와 p+-n-n+ 구조에서 양자점 층이 공핍 층으로부터 멀리 떨어진 n-base 영역에 삽입하여 실험결과를 비교분석하였다. PR 실험결과로부터, p-i-n 구조에서 InAs 양자점 태양전지의 내부전기장 변화는 potential barrier 두께에 따라 다소 복잡한 변화를 보였으며, 이는 양자점 층이 공핍층 내에 위치함으로써 격자 불일치(lattice mismatch)로 발생된 응력(strain)의 영향으로 설명할 수 있다. 이러한 결과들을 각각의 태양전지 구조에서 표면 및 내부전기장에 대해 계산된 값들에 근거하여, p+-n-n+ 구조에서 양자점 층이 공핍 층으로부터 멀리 떨어진 영역에 삽입된 경우의 결과와 비교해 보면 내부전기장의 변화는 더욱 분명해진다. 즉, 양자점 층의 potential barrier의 두께를 조절하거나, 양자점 층의 위치를 변화시킴으로써 양자점 태양전지의 내부전기장을 조작할 수 있으며, 이는 PR 실험을 통해 FKO를 관측함으로써 확인할 수 있다.

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Effect of the Water Extract of Persicae Semen on Promotion of Axon Regeneration (도인(桃仁)이 중추신경 재생 촉진에 미치는 영향)

  • Shin, Jin-Bong;Moon, Goo;Lee, Jong-Deuk;Won, Jin-Hee;Lee, Jae-Won
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.21 no.1
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    • pp.145-152
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    • 2007
  • Following CNS injury, inhibitory influences at the site of axonal damage occur. Glial cells become reactive and form a glial scar, gliosis. Astrocyte-rich gliosis relates with up-regulation of GFAP and CD81, and eventually becomes physical and mechanical barrier to axonal regeneration. It is postulated that the astrocytic reaction is absent, regeneration of axons can occur. And it was reported that treatment with anti CD81 antibodies enhanced functional recovery in the rat with spinal cord injury. So in this current study, the author investigated the effect of the water extract of Persicae Semen on the regulation of GFAP and CD81 that increase when gliosis occurs. Persicae Semen decreased the expression of GFAP and CD81 in astrocyte cell by ELISA method. Persicae Semen decreased the RNA expression of CD81 and GFAP. The proteins that separate in whole cell were analaysed by western blot, and the expression of GFAP and CD81 was decreased. In vivo, rats brains were peformed cortical stab wound, the water extracts of Persicae Semen were injected for 7 days, 30 days. As a result, GFAP and CD81 expression were decreased in immunohistochemistry. These findings demonstrate that Persicae Semen decreases GFAP and CD81 expression. Accordingly, Persicae Semen could be a candidate for promotion of axon regeneration after CNS injury.

Internal Energy Distributions of OH Products in the Reaction of O(3PJ) with HSiCl3

  • Kwak, Hyon-Tae;Ha, Seung-Chul;Jang, Sung-Woo;Kim, Hong-Lae;Park, Chan-Ryang
    • Bulletin of the Korean Chemical Society
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    • v.30 no.2
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    • pp.429-434
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    • 2009
  • The OH($X^2{\Pi},\;{\nu}$"=0, 1) internal state distributions from the reaction of electronically ground state oxygen atoms with HSi$Cl_3$ were measured using laser-induced fluorescence. The ground-state O$(^3P_J)$ atoms with kinetic energies above the reaction barrier were produced by photolysis of N$O_2$ at 355 nm. The OH product revealed strong vibrational population inversion, P(${\nu}$"=1)/P(${\nu}$"=0) = 4.0 ${\pm}$ 0.6, and rotational distributions in both vibrational states exhibit substantial rotational excitations to the limit of total available energy. However, no preferential populations in either of the two $\Lambda$ doublet states were observed from the micropopulations, which supports a mechanism involving a direct abstraction of hydrogen by the atomic oxygen. It was also found that the collision energy between O and HSi$Cl_3$ is effectively coupled into the excitation of the internal degrees of freedom of the OH product ($$ = 0.62, and $<\;f_{rot}>$ = 0.20). The dynamics appear consistent with expectations for the kinematically constrained reaction which supports the reaction type, heavy + light-heavy $\rightarrow$ heavy-light + heavy (H + LH′ $\rightarrow$ HL + H′). The dynamics of oxygen atom collision with HSi$Cl_3$ are discussed in comparison to those with Si$H_4$.