• Title/Summary/Keyword: carrier transport

Search Result 533, Processing Time 0.035 seconds

Analysis of the Transport System of Cadmium and the Change of Proline Content in Spring Radish Young Plant (봄무우 유식물에서 카드뮴 운반계와 Proline 농도 변화의 분석)

  • Park, Sun Young;Park, Myon-Yong;Cho, Bong-Heuy
    • Analytical Science and Technology
    • /
    • v.9 no.2
    • /
    • pp.134-138
    • /
    • 1996
  • Cadmium was transported through the special carrier system into the cells of cotyledons, hypocotyls, and roots spring radish young plants. The transport of cadmium was inhibited by metabolic inhibitor, like DNP. The $K_m$ values for cadmium were 0.7 ppm for cotyledons, 1.72 ppm for hypocotyls, and 0.3 ppm for roots, and $V_{max}$ for cadmium was $40ppm{\cdot}h^{-1}{\cdot}g{\cdot}fresh\;weight^{-1}$ for cotyledons, $313ppm{\cdot}h^{-1}{\cdot}g{\cdot}fresh\;weight^{-1}$ for hypocotyls, and $606ppm{\cdot}h^{-1}{\cdot}g{\cdot}fresh\;weight^{-1}$ for roots. Cadmium cannot prove to be inducer for proline accumulation. Therefore, proline accumulation cannot be used as a marker to test the level of heavy metal pollution.

  • PDF

Nonstoichiometric Effects in the Leakage Current and Electrical Properties of Bismuth Ferrite Ceramics

  • Woo, Jeong Wook;Baek, SeungBong;Song, Tae Kwon;Lee, Myang Hwan;Rahman, Jamil Ur;Kim, Won-Jeong;Sung, Yeon Soo;Kim, Myong-Ho;Lee, Soonil
    • Journal of the Korean Ceramic Society
    • /
    • v.54 no.4
    • /
    • pp.323-330
    • /
    • 2017
  • To understand the defect chemistry of multiferroic $BiFeO_3-based$ systems, we synthesized nonstoichiometric $Bi_{1+x}FeO_{3{\pm}{\delta}}$ ceramics by conventional solid-state reaction method and studied their structural, dielectric and high-temperature charge transport properties. Incorporation of an excess amount of $Bi_2O_3$ lowered the Bi deficiency in $BiFeO_3$. Polarization versus electric field (P-E) hysteresis loop and dielectric properties were found to be improved by the $Bi_2O_3$ addition. To better understand the defect effects on the multiferroic properties, the high temperature equilibrium electrical conductivity was measured under various oxygen partial pressures ($pO_2{^{\prime}}s$). The charge transport behavior was also examined through thermopower measurement. It was found that the oxygen vacancies contribute to high ionic conduction, showing $pO_2$ independency, and the electronic carrier is electron (n-type) in air and Ar gas atmospheres.

Design and Performance Analysis of CPSK Transmitter for RF-CBTC System in ISM Band (RF-CBTC 시스템을 위한 ISM 대역에서의 CPSK 송신기의 설계 및 성능분석)

  • Kim, Seong-Cheol
    • The Journal of The Korea Institute of Intelligent Transport Systems
    • /
    • v.16 no.5
    • /
    • pp.152-161
    • /
    • 2017
  • The CBTC(Communication based Train Control) system employed on 2.4GHz ISM band adopt the IEEE802.11.x standard. Therefor communication time delay, distortion and data losses will be produced. To overcome these problems, CPSK(Continuous Phase shift keying) modulated DS/SS(Direct Sequence Spread Spectrum) transmitter with 908MHz carrier frequency is proposed. Through the eye diagram and scatter diagram the performance is analysed. And the phase noise characteristic of the local oscillator is measured about 60dBc/Hz, this means that the phase noise performance is very good compared to the signal. Reference frequency suppression of the 2nd local oscillator is 50dB below compared to the signal. Through the polarities of the complementary signal equally probable, the line spectrum of the output spectrum is eliminated. The nonlinear effects which introduce the spectral spreading or spectral regeneration is reduced remarkably.

Design of High Efficiency Switching-Mode Doherty Power Amplifier Using GaN HEMT (GaN HEMT를 이용한 고효율 스위칭 모드 도허티 전력증폭기 설계)

  • Choi, Gil-Wong;Kim, Hyoung-Jong;Choi, Jin-Joo;Kim, Seon-Joo
    • The Journal of The Korea Institute of Intelligent Transport Systems
    • /
    • v.9 no.5
    • /
    • pp.72-79
    • /
    • 2010
  • In this paper, we describe the design and implementation of a high efficiency Doherty power amplifier using gallium nitride (GaN) high-electron mobility transistor (HEMT). The carrier and peaking amplifiers of the proposed Doherty power amplifier consist of the switching-mode Class-E power amplifiers. The test conditions are a duty of 10% and a pulse width of $100\;{\mu}s$ and pulse repetition frequency (PRF) of 1 kHz for a S-band radar application. A RF performance peak PAE of 64% with drain efficiency of 80.6%, at 6 dB output back-off point from saturated output power of 45.5 dBm, was obtained at 2.85 GHz.

An Analysis on the Efficiency of Low-Cost Air Lines in Korea (국내 저가항공사 노선 효율성 평가)

  • Choi, Ki-Seoun;Kim, Woo-Jae
    • Journal of the Korean Society for Aeronautical & Space Sciences
    • /
    • v.46 no.5
    • /
    • pp.436-444
    • /
    • 2018
  • The purpose of this research is to assess the efficiency of the airline's route. The revenue source of low cost airline carriers is not various unlike regular airline carriers, because they are operating only domestic and international flights for a country of close proximity. In particular, domestic low-cost airlines in Korea can't provide cargo transport services but rely on passengers and additional services to generate profits. Therefore, it is absolutely important to maintain a low cost and effective passenger transport line. This study will suggest the way to improve efficiency of route operated by low-cost airlines. Analysis method is DEA. The input parameters and output results were selected by existing research. Based on the results of this study, it will be able to assist establishing routes and selling strategies of the low-cost airlines.

UV Photo Response Driven by Pd Nano Particles on LaAlO3/SrTiO3 Using Ambient Control Kelvin Probe Force Microscopy

  • Kim, Haeri;Chan, Ngai Yui;Dai, Jiyan;Kim, Dong-Wook
    • Proceedings of the Korean Vacuum Society Conference
    • /
    • 2014.02a
    • /
    • pp.207.1-207.1
    • /
    • 2014
  • High-mobility and two dimensional conduction at the interface between two band insulators, LaAlO3 (LAO) and SrTiO3 (STO), have attracted considerable research interest for both applications and fundamental understanding. Several groups have reported the photoconductivity of LAO/STO, which give us lots of potential development of optoelectronic applications using the oxide interface. Recently, a giant photo response of Pd nano particles/LAO/STO is observed in UV illumination compared with LAO/STO sample. These phenomena have been suggested that the correlation between the interface and the surface states significantly affect local charge modification and resulting electrical transport. Water and gas adsorption/desorption can alter the band alignment and surface workfunction. Therefore, characterizing and manipulating the electric charges in these materials (electrons and ions) are crucial for investigating the physics of metal oxide. Proposed mechanism do not well explain the experimental data in various ambient and there has been no quantitative work to confirm these mechanism. Here, we have investigated UV photo response in various ambient by performing transport and Kelvin probe force microscopy measurements simultaneously. We found that Pd nano particles on LAO can form Schottky contact, it cause interface carrier density and characteristics of persistence photo conductance depending on gas environment. Our studies will help to improve our understanding on the intriguing physical properties providing an important role in many enhanced light sensing and gas sensing applications as a catalytic material in different kinds of metal oxide systems.

  • PDF

Transposition of Intravascular Lipid in Experimentally Induced Fat Embolism: A Preliminary Study

  • Hwang, So-Min;Lee, Jong-Seo;Kim, Hong-Il;Jung, Yong-Hui;Kim, Hyung-Do
    • Archives of Plastic Surgery
    • /
    • v.41 no.4
    • /
    • pp.325-329
    • /
    • 2014
  • Background Liposuction is a procedure to reduce the volume of subcutaneous fat by physical force. Intracellular storage fat is composed of triglyceride, whereas circulating fat particles exist as cholesterol or triglycerol bound to carrier proteins. It is unavoidable that the storage form of fat particles enters the circulation system after these particles are physiologically destroyed. To date, however, no studies have clarified the fatal characteristics of fat embolism that occurs after the subclinical phase of free fat particles. Methods A mixture of human lipoaspirate and normal saline (1:100, 0.2 mL) was injected into the external jugular vein of rats, weighing 200 g on average. Biopsy specimens of the lung and kidney were examined at 12-hour intervals until postoperative 72 hours. The deposit location and transport of the injected free fat particles were confirmed histologically by an Oil Red O stain. Results Inconsistent with previous reports, free fat particles were transported from the intravascular space to the parenchyma. At 24 hours after infusion, free fat particles deposited in the vascular lumen were confirmed on the Oil Red O stain. At 72 hours after infusion, free fat particles were accumulated compactly within the parenchymal space near the perivascular area. Conclusions Many surgeons are aware of the fatal results and undiscovered pathophysiologic mechanisms of free fat particles. Our results indicate that free fat particles, the storage form of fat that has been degraded through a physiological process, might be removed through a direct transport mechanism and phagocytotic uptake.

Formation and Current-voltage Characteristics of Molecularly-ordered 4,4',4''-tris(N-(1-naphthyl)-N-phenylamino)-triphenylamine film (분자배열된 4,4',4''-tris(N-(1-naphthyl)-N-phenylamino)-triphenylamine 박막 제조와 전기적 특성)

  • Kang, Do Soon;Choe, Youngson
    • Applied Chemistry for Engineering
    • /
    • v.18 no.5
    • /
    • pp.506-510
    • /
    • 2007
  • Vacuum deposited 4,4',4''-tris(N-(1-naphthyl)-N-phenylamino)-triphenylamine (1-TNATA), a widely-used semiconductor material, is placed as a thin interlayer between indium tin oxide (ITO) electrode and a hole transporting layer (HTL) in OLEDs and a well-stacked 1-TNATA layer leads to stable and high efficiency devices by reducing the carrier injection barrier at the interface between the ITO anode and hole transport layers. According to Raman spectra, thermal annealing after deposition as well as electromagnetic field treatment during deposition lead to closer stacking of 1-TNATA molecules and resulted in molecular ordering. By thermal annealing at about $110^{\circ}C$, an increase in current flow through the film by over 25% was observed. Molecularly-ordered 1-TNATA films played an important role in achieving higher luminance efficiency as well as higher power efficiency of the multi-layered organic EL devices in the present work. Electromagnetic field treatment during deposition was less effective compared to thermal annealing

Revisiting Apoplastic Auxin Signaling Mediated by AUXIN BINDING PROTEIN 1

  • Feng, Mingxiao;Kim, Jae-Yean
    • Molecules and Cells
    • /
    • v.38 no.10
    • /
    • pp.829-835
    • /
    • 2015
  • It has been suggested that AUXIN BINDING PROTEIN 1 (ABP1) functions as an apoplastic auxin receptor, and is known to be involved in the post-transcriptional process, and largely independent of the already well-known SKP-cullin-F-box-transport inhibitor response (TIR1) /auxin signaling F-box (AFB) ($SCF^{TIR1/AFB}$) pathway. In the past 10 years, several key components downstream of ABP1 have been reported. After perceiving the auxin signal, ABP1 interacts, directly or indirectly, with plasma membrane (PM)-localized transmembrane proteins, transmembrane kinase (TMK) or SPIKE1 (SPK1), or other unidentified proteins, which transfer the signal into the cell to the Rho of plants (ROP). ROPs interact with their effectors, such as the ROP interactive CRIB motif-containing protein (RIC), to regulate the endocytosis/exocytosis of the auxin efflux carrier PIN-FORMED (PIN) proteins to mediate polar auxin transport across the PM. Additionally, ABP1 is a negative regulator of the traditional $SCF^{TIR1/AFB}$ auxin signaling pathway. However, Gao et al. (2015) very recently reported that ABP1 is not a key component in auxin signaling, and the famous abp1-1 and abp1-5 mutant Arabidopsis lines are being called into question because of possible additional mutantion sites, making it necessary to reevaluate ABP1. In this review, we will provide a brief overview of the history of ABP1 research.

Non-contact Transportation of Flat Panel Substrate by Combined Ultrasonic Acoustic Viscous and Aerostatic Forces

  • Isobe, Hiromi;Fushimi, Masaaki;Ootsuka, Masami;Kyusojin, Akira
    • International Journal of Precision Engineering and Manufacturing
    • /
    • v.8 no.2
    • /
    • pp.44-48
    • /
    • 2007
  • In recent years, the size of plane substrates and semiconductor wafers has increased. As conventional contact transportation systems composed of, for example, carrier rollers, belt conveyers, and robot hands carry these longer and wider substrates, the increased weight results in increased potential for fracture. A noncontact transportation system is required to solve this problem. We propose a new noncontact transportation system combining acoustic viscous and aerostatic forces to provide damage-free transport. In this system, substrates are supported by aerostatic force and transported by acoustic viscous streaming induced by traveling wave deformation of a disk-type stator. A ring-type piezoelectric transducer bonded on the stator excites vibration. A stator with a high Q piezoelectric transducer can generate traveling vibrations with amplitude of $3.2{\mu}m$. Prior to constructing a carrying road for substrates, we clarified the basic properties of this technique and stator vibration characteristics experimentally. We constructed the experimental equipment using a rotational disk with a 95-mm diameter. Electric power was 70 W at an input voltage of 200 Vpp. A rotational torque of $8.5\times10^{-5}Nm$ was obtained when clearance between the stator and disk was $120{\mu}m$. Finally, we constructed a noncontact transport apparatus for polycrystalline silicon wafers $(150(W)\times150(L)\times0.3(t))$, producing a carrying speed of 59.2 mm/s at a clearance of 0.3 mm between the stator and wafer. The carrying force when four stators acted on the wafer was $2\times10^{-3}N$. Thus, the new noncontact transportation system was demonstrated to be effective.