• Title/Summary/Keyword: carrier transport

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Effect of Amoxicillin on the Intestinal Membrane Permeability and Absorption Clearance of Benazepril (베나제프릴의 장관막 투과도와 흡수 클리어런스에 미치는 아목시실린의 영향)

  • Joo, Eun-Hee;Kim, Young-Man;Ko, Hyung-Seok;Lee, Yong-Bok;Na, Han-Kwang
    • Journal of Pharmaceutical Investigation
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    • v.28 no.1
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    • pp.25-33
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    • 1998
  • Intestinal absorption of ${\beta}-lactam$ antibiotics and angiotensin converting enzyme(ACE) inhibitors has been shown to use the carrier-mediated transport system. In vitro experiments have established that the efficacy of uptake by enterocytes depends on an inwardly directed proton gradient. It was suggested that benazepril was mediated by tripeptide transport system and that amoxicillin was transported by dipeptide transport carrier. The aim of this study is to assess the influence of amoxicillin on the intestinal absorption of benazepril using in vitro diffusion chamber and in situ single pass perfusion technique in the rat in order to elucidate whether the above transport systems are competitive or not. We obtained the gastrointestinal pemeability coefficient of amoxicillin, benazepril and both of them using in vitro diffusion chamber. And also the gastrointestinal absorption clearance of amoxicillin, benazepril and both of them using in situ single-pass perfusion method at steady state were calculated. Amoxicillin and benazepril were analyzed by HPLC. The results by the use of diffusion chamber in vitro indicated that the apparent intestinal permeability coefficient of benazepril was significantly(p<0.01) decreased by amoxicillin(45.2%) and vice versa significantly(p<0.01) decreased(89.1%). The results by the in situ gastrointestinal single-pass perfusion method indicated that the intestinal absorption clearance of benazepril was significantly(p<0.05) decreased by amoxicillin (40.2%) and vice versa significantly(p<0.05) decreased(54.8%). These results might suggest that they share the same peptide carrier pathway for oral absorption.

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A Study on the Legal Effectiveness of Unknown Wording and on Deck Indication of the Article 26 of UCP 600 (UCP 600 제26조 상의 부지문언과 갑판적재표시의 법률적 효력에 관한 연구)

  • PARK, Sung-Cheul
    • THE INTERNATIONAL COMMERCE & LAW REVIEW
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    • v.69
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    • pp.221-237
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    • 2016
  • This study aims to review the article 26 of UCP 600. The article 26 of UCP 600 deals with 'on deck cargo' and 'unknown wording' in L/C transaction. The article 26 of UCP 600 says that a transport document stating that the goods may be carried on deck is accept able. UCP 600 requires to reject transport documents which evidence that the goods are or will be loaded on deck. So the bank will not accept the B/L containing a clause stating the goods are or will be loaded on deck. But in practice a container cargo is carried on deck actually but we do not describe this fact on the Bill of Lading. The deck stowage is not allowed under the clean B/L. But in case of container cargo, the carrier has the right to carry the container on deck in practice. In spite of this practice the carrier can not describe this fact correctly like this : "The container cargo loaded on deck". If carrier describes on B/L like this, the bank rejects the B/L in L/C transaction. So the carrier describes as "the goods may be carried on deck" on the back of the B/L. But they loaded the container on deck actually. This article suggests some ideas on this matter. In addition, the article 26 of UCP 600 says that a transport document bearing a clause such as "shipper's load count" or "said by shipper to contain" is acceptable. This means that a carrier has no responsibility on the contents of containers. In case of FCL Cargo, it is impossible for a carrier to check the details of container cargo. Therefore it is inevitable to insert the expressions such as "SLC(shipper's load and count)" or "STC(said to contain)". The wording described on the face of B/L should be interpreted as intended and consistently. The intention of the carrier is not the actual quantity or weight. So unknown wording does not represent the actual quantity or weight. But some cases show that the carriers are indemnified by such insertion but others reject the effectiveness of such insertion. So this study emphasizes that unknown wording can not fully indemnify the carriers and that the insertion of such expressions shall be minimized.

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On the Carrier Spacing for Mobile Multimedia Systems

  • Hong Een-Kee;Yun Sang-Hyuck;Kim Jeong-Geun
    • Journal of Communications and Networks
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    • v.8 no.2
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    • pp.182-186
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    • 2006
  • Previous approaches to sizing the carrier spacing for voice-oriented cellular systems have been based on the outage requirement. However, such a design paradigm needs to be changed as the performance of most upcoming cellular systems employing adaptive modulation and coding (AMC) techniques is more sensitive to throughput than outage. In this paper, we propose a novel approach to determining the carrier spacing which is based on a throughput criterion. The proposed method reflects well the characteristics of throughput-sensitive cellular systems that transport multimedia traffic. Numerical results show that our approach requires less carrier spacing, thus leading to more efficient spectrum utilization.

Terahertz Oscillations in p-Type Quantum-Well Oscillators

  • Cao, J.C.;Li, A.Z.
    • Journal of Korean Vacuum Science & Technology
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    • v.6 no.1
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    • pp.43-45
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    • 2002
  • We have theoretically investigated steady-state carrier transport and current self-oscillation in negative-effective-mass (NEM) p$\^$+/pp$\^$+/diodes. The current self-oscillation here is a result of the formation and traveling of electric field domains in the p base having a NEM. The dependence of self-oscillating frequency on the applied dc voltage is obtained by detailed numerical simulations. In the calculations, we have considered the scatterings by carrier-impurity, carrier-acoustic phonon, carrier-polar-phonon, and carrier-nonpolar-phonon-hole interactions . This kind of NEM oscillator allows us to reach a current oscillation with terahertz frequency, thus it may be used as a broadband source of terahertz radiation.

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Simulation of Submicron MOSFET Using Hydrodynamic Model (Hydrodynamic model을 이용한 Submicron MOSFET의 Simulation)

  • 김충원;한백형;김경석
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.30A no.11
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    • pp.122-131
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    • 1993
  • In this paper, we have developed a submicron Si MOSFET simulator, which is physically based on the hydrodynamic energy transport mode. The simulator was used to investigate the nonstationary transport effects and the transient phenomena in submicron Si MOSFET's. It is found that the velocity overshoot and the carrier heating are dominant transport mechanism near the drain end of the channel and the transient phenomena is more retained in a long channel MOSFET.

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Studies on the Macrocycle-mediated Transport of Divalent Metal Ions in a Supported Liquid Membrane System

  • 조문환;신상철
    • Bulletin of the Korean Chemical Society
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    • v.16 no.1
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    • pp.33-36
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    • 1995
  • Macrocyclic ligands have been studied as cation carriers in a supported liquid membrane system. Cd2+ has been transported using nitrogen substituted macrocycles as carriers and several divalent metal ions (M2+=Zn, Co, Ni, Cu, Pb, Mg, Ca, and Sr) have been transported using DBN3O2, DBN2O2and PolyNtnoen as carriers in a supported liquid membrane system. Competitive Cd2+-M2+ transport studies have also been carried out with the same system. Ligand structure, stability constant, membrane solvent and carrier concentration are also important parameters in the transport of metal ions.

Numerical Analysis on Heat Transfer Characteristics in Silicon Boated by Picosecond-to-Femtosecond Ultra-Short Pulse Laser (펨토초급 극초단 펄스레이저에 의해 가열된 실리콘 내의 열전달 특성에 관한 수치해석)

  • 이성혁;이준식;박승호;최영기
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.26 no.10
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    • pp.1427-1435
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    • 2002
  • The main aim of the present article is numerically to investigate the micro-scale heat transfer phenomena in a silicon microstructure irradiated by picosecond-to-femtosecond ultra-short laser pulses. Carrier-lattice non-equilibrium phenomena are simulated with a self-consistent numerical model based on Boltzmann transport theory to obtain the spatial and temporal evolutions of the lattice temperature, the carrier number density and its temperature. Especially, an equilibration time, after which carrier and lattice are in equilibrium, is newly introduced to quantify the time duration of non-equilibrium state. Significant increase in carrier temperature is observed for a few picosecond pulse laser, while the lattice temperature rise is relatively small with decreasing laser pulse width. It is also found that the laser fluence significantly affects the N 3 decaying rate of Auger recombination, the carrier temperature exhibits two peaks as a function of time due to Auger heating as well as direct laser heating of the carriers, and finally both laser fluence and pulse width play an important role in controlling the duration time of non-equilibrium between carrier and lattice.

Research on the PAPR Reduction Method using Selection of Extra Code Set in PB/MC-CDMA System (PB/MC-CDMA 시스템에서 여분의 코드집합을 이용한 PAPR 감쇄기법에 관한 연구)

  • Lee, Kyu-Jin;Lee, Dong-Joon;Lee, Kye-San;Kim, Jin-Young
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.8 no.1
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    • pp.110-118
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    • 2009
  • The PB/MC-CDMA(Partial Block Multi Carrier Code Division Multilple Access) system can improve the performance by reducing the ICI(Inter-Code Interference) between users. Also, this system can achieve the frequency diversity gain by avoiding ISI(Inter Symbol Interference). Therefore, the performance of PB/MC-CDMA system is better than that of conventional MC-CDMA(Multi Carrier Code Division Multiple Access) system. However, similarly to other multi-carrier systems, it still has a PAPR(Peak to Average Power Ratio) issue. In this paper, we propose a peak power reduction technique involving optimized spreading code selection without side information for the PB/MC-CDMA. The PB/MC-CDMA system in each block of units reuses the code so the extra code will be remained. This extra code is divided into several groups to calculate the PAPR and solving the PAPR problem by transferring the selected code which has minimum peak power.

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Tansport Rate of Chromium ion from Waste Water through the Liquid Surfactant Membrane Containing Carrier (운반체 함침 유화액막에 의한 폐수중 크롬(VI)의 이동속도)

  • Woo, In-Sung;Kim, Kyoung-Ho;Lee, Sang-Jin;Kang, An-Soo;Choi, Sei-Young
    • Elastomers and Composites
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    • v.23 no.1
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    • pp.11-17
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    • 1988
  • The transport of chromium(VI) ion from waste water through the liquid surfactant membrane containing tri-n-octylamine as a carrier, was analyzed by a slab model and was investigated through experiments. For the experiment of membrane stability, concentrations of surfactant and liquid paraffin oil were analyzed. Extraction experiments were carried out to observe the effect of system variables, such as concentrations of carrier, and initial chromium(VI) ion in external aqueous phase at $25^{\circ}C$. It is concluded that the most stable formation of liquid membrane emulsion was obtained when surfactant concentration is above 3 wt.% and liquid paraffin oil concentration is 50 vol.%. The theoretical equation on the transport of chromium(VI) ion agreed well with the experimental results.

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