• 제목/요약/키워드: Carrier injection

검색결과 244건 처리시간 0.035초

Pulsed Amperometric Detection of Metal Ions Complexing with EDTA in a Flow Injection System

  • 이준우;여인형;편종홍
    • Bulletin of the Korean Chemical Society
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    • 제18권3호
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    • pp.316-318
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    • 1997
  • A general and universal detection method, which can be used in high performance liquid chromatography (HPLC) and flow injection analysis (FIA) system for the determination of any metal ions complexing with ethylenediaminetetraacetic acid (EDTA), is demonstrated. Pulsed amperometric detection scheme is applied in a flow-through thin layer electrochemical cell at an Au working electrode. Fluctuation of peak current level at the same flow rate of carrier solution is minimized at this solid working electrode, whereas not at a dropping mercury electrode. Removal of dissolved oxygen can be omitted with this detection method, which is a required step for cathodic detection methods. Also, a group of metal ions can be determined selectively and indirectly with this detection scheme.

금속-고분자 계면에서 캐리어의 거동 (Carriers Behavior in Metal-Polymer Interface)

  • 이승훈;최용성;이경섭
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2008년도 제39회 하계학술대회
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    • pp.2313-2314
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    • 2008
  • In this paper, the behaviour of charge carriers near the metal/polymer interface and its effects on conduction and breakdown phenomena are discussed. The metal/polymer interface strongly affects carrier injection, space charge formation and breakdown phenomena. Based on their experimental results, the physical backgrounds of the interfacial phenomena are explained.

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P-채널 poly-Si TFT's의 Alternate Bias 스트레스 효과 (Effect of Alternate Bias Stress on p-channel poly-Si TFT's)

  • 이제혁;변문기;임동규;정주용;이진민
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 1999년도 춘계학술대회 논문집
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    • pp.489-492
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    • 1999
  • The effects of alternate bias stress on p-channel poly-Si TPT's has been systematically investigated. It has been shown that the application of alternate bias stress affects device degradation for the negative bias stress as well as device improvement for the positive bias stress. This effects have been related to the hot carrier injection into the gate oxide rather than the generation of defect states within the poly-Si/SiO$_2$ under bias stress.

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커패시터 전압 자기 밸런싱 기능이 있는 새로운 6-레벨 인버터 토폴로지 (A Novel Six-Level Inverter Topology with Capacitor Voltage Self-Balancing)

  • 프리바디조나단;이동춘
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 2020년도 전력전자학술대회
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    • pp.316-317
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    • 2020
  • In this paper, a novel six-level inverter is proposed. Voltage regulation is applied at DC-link and flying capacitors through the implementation of phase-shifted carrier-based modulation with zero-sequence voltage injection. The performance of the proposed structure has been verified under various modulation indices, where low voltage ripple is achieved at each capacitor and total harmonic distortions (THD) of line voltage at unity modulation index is about 15.95%.

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열적으로 강인한 Molybdenium 게이트-PMOS Capacitor의 분석 (Analysis of PMOS Capacitor with Thermally Robust Molybdenium Gate)

  • 이정민;서현상;홍신남
    • 한국전기전자재료학회논문지
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    • 제18권7호
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    • pp.594-599
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    • 2005
  • In this paper, we report the properties of Mo metal employed as PMOS gate electrode. Mo on $SiO_2$ was observed to be stable up to $900^{\circ}C$ by analyzing the Interface with XRD. C-V measurement was performed on the fabricated MOS capacitor with Mo Bate on $SiO_2$. The stability of EOT and work-function was verified by comparing the C-V curves measured before and after annealing at 600, 700, 800, and $900^{\circ}C$. C-V hysteresis curve was performed to identify the effect of fired charge. Gate-injection and substrate-injection of carrier were performed to study the characteristics of $Mo-SiO_2$ and $SiO_2-Si$ interface. Sheet resistance of Mo metal gate obtained from 4-point probe was less than $10\;\Omega\Box$ that was much lower than that of polysilicon.

고로의 연소효율을 높이기 위한 미분탄 공급 시스템 개발 (Pulverized coal injection system development to raise combustion efficiencies of a blast furnace)

  • 안영진;강법성;곽남수;최경민;이민철
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2008년도 추계학술대회B
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    • pp.3163-3168
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    • 2008
  • Pulverized coal (PC) has become an important auxiliary fuel in the iron and steel industry since the technique of pulverized coal injection (PCI) system was developed for iron making. Combustion efficiencies of pulverized coal in blowpipes and tuyeres under various operational are numerically predicted to recognize the performance with the locations of nozzles in a blast furnace. A variety of parameters including the pulverized coal quantities, oxygen amounts, inlet temperature of the tuyeres and mass flow rate of coal carrier gas are taken into consideration. Also In order to develop more efficient than existing coal injection system, this study applies a flame measurement system using a charge couple device (CCD) camera and frame grabber. And it has used algorithms of auto sampling from flame shape information and composed the device for location control of PCI. This study find to further improve the blast furnace performance by the control of PCI locations.

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Active Immunization against Adrenocorticotropic Hormone in Growing-Finishing Barrows: An Initial Trial and Evaluation

  • Lee, C.Y.;Baik, K.H.;Jeong, J.H.;Lee, S.D.;Park, J.K.;Song, Y.M.;Kim, Y.S.;Sohn, S.H.
    • Asian-Australasian Journal of Animal Sciences
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    • 제15권3호
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    • pp.410-415
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    • 2002
  • Adrenal glucocorticoids, secreted by the stimulus of adrenocorticotropic hormone (ACTH), are catabolic hormones in the pig. The present study was conducted to find whether active immunization against ACTH would suppress cortisol secretion accompanied by an increased growth rate in growing-finishing barrows. ACTH was conjugated to keyhole limpet hemocyanin or human histone using glutaraldehyde or 3-maleimidobenzoic acid N-hydroxysuccinimide, under a 2 (ACTH vs no hapten)${\times}$2 (carrier)${\times}$2 (crosslinker) factorial arrangement of treatments. Cross-bred barrows weighing approximately 25 kg were injected with an ACTHcarrier or carrier only conjugate every 4th wk and slaughtered at approximately 110 kg body weight. Antibodies against ACTH were detected in serum, as determined by $[^{125}I]$ACTH-binding activity, in most animals immunized against the ACTH conjugate, but not in carrier only-injected animals, except for the animals which had received the hapten conjugated to histone via glutaraldehyde. The $[^{125}I]$ACTH-binding activity of serum increased after the second booster injection, but overall ACTH antibody titer was very low. Main effect was not detected not only for the carrier and crosslinker but for the hapten in serum cortisol concentration, ADG, loin muscle area, backfat thickness and longissimus muscle composition including fat and protein. In addition, bound $[^{125}I]$ACTH percentage had no relation to cortisol concentration or to any of the above growth-related variables. Results suggest that ACTH or its conjugates used in the present study were not immunogenically potent enough to affect the glucocorticoid secretion and thus the growth of the immunized pigs.

High Performance GaN-Based Light-Emitting Diodes by Increased Hole Concentration Via Graphene Oxide Sheets

  • Jeong, Hyun;Jeong, Seung Yol;Jeong, Hyun Joon;Park, Doo Jae;Kim, Yong Hwan;Kim, HyoJung;Lee, Geon-Woong;Jeong, Mun Seok
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2013년도 제45회 하계 정기학술대회 초록집
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    • pp.244.1-244.1
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    • 2013
  • The p-type GaN which act as a hole injection layer in GaN-based LEDs has fundamental problems. The first one arises from the difficulty in growing a highly doped p-GaN (with a carrier concentration exceeding ~1018 $cm^{-3}$). And the second one is the absence of appropriate metals or conducting oxides having a work function that is larger than that of p-type GaN (7.5 eV). Moreover, the LED efficiency is decreases gradually as the injection current increases (the so-called 'efficiency droop' phenomenon). The efficiency droop phenomenon in InGaN quantum wells (QWs) has been a large obstacle that has hindered high-efficiency operation at high current density. In this study, we introduce the new approaches to improve the light-output power of LEDs by using graphene oxide sheets. Graphene oxide has many functional groups such as the oxygen epoxide, the hydroxyl, and the carboxyl groups. Due to nature of such functional groups, graphene oxide possess a lot of hole carriers. If graphene oxide combine with LED top surface, graphene oxide may supply hole carriers to p-type GaN layer which has relatively low free carrier concentration less than electron concentration in n-type GaN layer. To prove the enhancement factor of graphene oxide coated LEDs, we have investigated electrical and optical properties by using ultra-violet photo-excited spectroscopy, confocal scanning electroluminescence microscopy.

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흐름주입분석법에 의한 환경시료 중$N(NO_2^-),\;N(NO_3^-)$$N(NH_4^+)$의 정량분석에 관한 연구 (A Study on the Determination of$N(NO_2^-),\;N(NO_3^-)$and$N(NH_4^+)$in Environmental Samples by Flow Injection Analysis)

  • 이재성;김영상;정윤희;이희정
    • 대한화학회지
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    • 제41권5호
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    • pp.256-265
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    • 1997
  • 토양과 수질시료 중에서 nitrite, nitrate 그리고 ammonia성 질소를 빠르고 연속적으로 정량할 수 있는 방법에 관하여 연구하였다. 실제시료를 측정하기전에 각 성분의 표준시료를 사용하여 FIA의 구조적 인자(주입 양, 반응코일 길이 그리고 흐름속도)를 결정하였다. Nitrite는 Griess reaction에 의해 sulfanilamide와 반응 후 N-(1-naphthylenediamine dihydrochloride)과 결합하여 azo 색소를 형성시킨 후 540 nm에서 측정하였고, nitrate는 hydrazine을 사용하여 nitride로 환원시킨 후 측정하였다. Ammonia는 Nessler법을 사용하여 440 nm에서 측정하였다. 최적 조건에서 $N(NO_2^-),\;N(NO_3^-)와\;N(NH_4^+)$의 검출한계(S/N=3)는 0.1 ㎍/ML, 0.4 ㎍/mL 그리고 0.3 ㎍/ML이었다. 실제시료를 비색법, ion chromatography 및 FIA로 측정하여 비교한 결과 상호 일치성이 80~125%로 나타내어 만족스러웠다. 시료의 주입횟수는 30회/시간 이상으로 조절할 수 있었다.

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Evaluation of thermally cross-linked superparamagnetic iron oxide nanoparticles for the changes of concentration and toxicity on tissues of Sprague-Dawley rats

  • Hue, Jin Joo;Lee, Hu-Jang;Jon, Sangyong;Nam, Sang Yoon;Yun, Young Won;Kim, Jong-Soo;Lee, Beom Jun
    • 대한수의학회지
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    • 제54권4호
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    • pp.245-252
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    • 2014
  • This study was investigated the change of concentration and toxicity of thermally cross-linked superparamagnetic iron oxide nanoparticles (TCL-SPION) on tissues of Sprague-Dawley rats. TCL-SPION at the dose of 15 mg/kg body weight was intravenously injected into the tail vein of the male Sprague-Dawley rats. The fate of TCL-SPION in serum, urine and tissues was observed during 28 days. Serum iron level was maximal at 0.25 h post-injection and gradually declined thereafter. In addition, the sinusoids of liver and the red pulp area of spleen were mainly accumulated iron from 0.5 h to 28-day post-injection. In kidney, iron deposition was detected in the tubular area until 0.5 h after injection. Malondialdehyde concentration in the liver slightly increased with time and was not different with that at zero time. In the liver and spleen, TNF-${\alpha}$ and IL-6 levels of TS treated with TCL-SPION were not different with those of the control during the experimental period. From the results, TCL-SPION could stay fairly long-time in certain tissues after intravenous injection without toxicity. The results indicated that TCL-SPION might be useful and safe as a contrast for the diagnosis of cancer or a carrier of therapeutic reagents to treat diseases.