• 제목/요약/키워드: trap density

검색결과 340건 처리시간 0.024초

More Reliable Length Composition And Biomass Of EEL Population In The Lagoons Of Arcachon Bay

  • Lee, Tae-Won
    • 한국해양학회지
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    • 제15권2호
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    • pp.108-111
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    • 1980
  • The sampling was made by a kind of trap nets and an electric fishing apparatus in the lagoons of Arcachon Bay. Length frequency distributions obtained by two gears are combined to propose more reliable length composition of the population. The biomass was estimated by the capture and recapture method in a limited area with electric fishing apparatus, and it was redressed based on the corrected length composition. It showed approximately 638kg/ha in the deeper parts of the lagoons. It suggests that the lagoons of Arcachon Bay contain relatively high density of eels.

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퇴적촉진 구조물 설치에 따른 중형저서동물 군집구조 및 변동 (Community Structure and Spatial Variation of Meiobenthos Associated with an Artificial Structure)

  • 민원기;김동성;이재학
    • 한국수산과학회지
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    • 제39권spc1호
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    • pp.223-230
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    • 2006
  • We investigated the spring and summer community structure of meiobenthos in a tidal-falt near Iwon, Korea, in 2002 and 2003. In total, 12 meiofaunal groups were found in the study area among which nematodes were the most dominant. Benthic foraminiferans, harpacticoid copepods, polychaetes, and crustacean nauplli were also dominant groups at all sites. The total density of meiobenthos at each station was be 246-2,177 ind./$10cm^2$. As the depth of sediment increased, the density of meiobenthos at each station gradually decreased. Changes in the vertical distribution of meiobenthos in the study area occurred mainly near the sediment surface (0-1 cm). Generally, between spring and summer the density of nematodes increased, and the density of other dominant meiofaunal groups (benthic harpacticoids, crustacean nauplii, benthic foraminiferans) decreased near the sediment trap the control site of sediment traps compared to that at the control site. The results of cluster and multidimensional scaling plots indicate that the meiofaunal community changed following construction of a low artificial wood groin structure.

SI GaAs : Cr과 Undoped GaAs의 깊은 준위 (Deep Levels in Semi-Insulating GaAs : Cr and Undoped GaAs)

  • 이진구
    • 대한전자공학회논문지
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    • 제25권11호
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    • pp.1294-1303
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    • 1988
  • 광 유도 전류 천이 (photo-induced current transient)방법으로 측정한 SI GaAs의 전자와 정공 trap이 갖을 수 있는 activation energy({\Delta}E_r)의 범위는 0.16$\pm$ 0.01eV에서 0.98$\pm$ 0.01eV까지 분포되어 있다. SI Undoped GaAs가 SI GaAs : Cr 보다 깊은 준위의 수가 적음을 확인 하였다. Trap의 열적인 capture cross section과 농도를 평가 하였고, 약간의 trap은 SI GaAs 성장시에 발생될 수 있는 결함과 관련되어 있음을 확인하였다. 특히 SI GaAs에서 보상 level로 작용하는 Cr과 “0” level를 좀 더 정확하게 측정하기 위하여 서로 다른 측정방법을 사용하여 측정한 결과를 각기 비교 검토 하였다. 즉, PICT측정, 상온 이상의 온도에서 측정한 Hall data 및 광전류 spectra data 등을 비교 검토 하였으며, 보상 level은 격자 결합이 매우 약함을 확인할 수 있었다. Hall data를 computer로 분석한 결과 중성 불순물 scattering이 측정 온도 범위에서 매우 중요한 역할을 하고 있음을 알 수 있었다.

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Modification of Schottky Barrier Properties of Ti/p-type InP Schottky Diode by Polyaniline (PANI) Organic Interlayer

  • Reddy, P.R. Sekhar;Janardhanam, V.;Jyothi, I.;Yuk, Shim-Hoon;Reddy, V. Rajagopal;Jeong, Jae-Chan;Lee, Sung-Nam;Choi, Chel-Jong
    • JSTS:Journal of Semiconductor Technology and Science
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    • 제16권5호
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    • pp.664-674
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    • 2016
  • The electrical properties of Ti/p-type InP Schottky diodes with and without polyaniline (PANI) interlayer was investigated using current-voltage (I-V) and capacitance-voltage (C-V) measurements. The barrier height of Ti/p-type InP Schottky diode with PANI interlayer was higher than that of the conventional Ti/p-type InP Schottky diode, implying that the organic interlayer influenced the space-charge region of the Ti/p-type InP Schottky junction. At higher voltages, the current transport was dominated by the trap free space-charge-limited current and trap-filled space-charge-limited current in Ti/p-type InP Schottky diode without and with PANI interlayer, respectively. The domination of trap filled space-charge-limited current in Ti/p-type InP Schottky diode with PANI interlayer could be associated with the traps originated from structural defects prevailing in organic PANI interlayer.

울산 해안의 습지 주위에 서식하는 주요 모기의 발생 소장 (Prevalence and Seasonal Abundance of the Dominant Mosquito Species in a Large Marsh near Coast of Ulsan)

  • 정영석;이동규
    • 한국응용곤충학회지
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    • 제42권2호
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    • pp.125-132
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    • 2003
  • 울산시 울주군 청량면 인근 해안가 주변의 저습지를 보유한 용암리에 서식하는 모기의 계절적 발생소장을 조사하였다. 성충 채집은 Nozawa 유문등을 이용하여 3년(1999-2001) 동안 3월부터 9월까지 두 곳의 우사에서 격주에 한번씩 암컷을 대상으로 실시하였다. 채집된 암컷 성충은 1999년에 트랩당 평균 4,416.1마리, 2000년에 5,505.9마리, 그리고 2001년에 6,863.8마리였다. 채집된 모기의 종류는 5속 10종이었으며, 가장 높은 채집수를 보인 종은 중국얼룩날개모기로 종비는 53.4%였으며 다음으로 작은빨간집모기(43.0%), 이나도미집모기(1.6%), 등줄숲모기(1.3%), 빨간집모기(0.5%) 순이었다. 말라리아 매개모기인 중국얼룩날개모기와 일본뇌염 매개모기인 작은빨간집모기의 주요발생 시기인 6월부터 9월까지의 트랩당 평균 채집수는 각각 3,663.3마리와 3,142.5마리였다. 1997년 조사에서 우점종으로 나타난 이나도미집모기의 채집수는 연중 7월 초순에 가장 높게 나타났다.

4H-SiC PiN 다이오드의 깊은 준위 결함에 따른 전기적 특성 분석 (Analysis of Electrical Characteristics due to Deep Level Defects in 4H-SiC PiN Diodes)

  • 이태희;박세림;김예진;박승현;김일룡;김민규;임병철;구상모
    • 한국재료학회지
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    • 제34권2호
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    • pp.111-115
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    • 2024
  • Silicon carbide (SiC) has emerged as a promising material for next-generation power semiconductor materials, due to its high thermal conductivity and high critical electric field (~3 MV/cm) with a wide bandgap of 3.3 eV. This permits SiC devices to operate at lower on-resistance and higher breakdown voltage. However, to improve device performance, advanced research is still needed to reduce point defects in the SiC epitaxial layer. This work investigated the electrical characteristics and defect properties using DLTS analysis. Four deep level defects generated by the implantation process and during epitaxial layer growth were detected. Trap parameters such as energy level, capture-cross section, trap density were obtained from an Arrhenius plot. To investigate the impact of defects on the device, a 2D TCAD simulation was conducted using the same device structure, and the extracted defect parameters were added to confirm electrical characteristics. The degradation of device performance such as an increase in on-resistance by adding trap parameters was confirmed.

ONO ($SiO_2/Si_3N_4/SiO_2$), NON($Si_3N_4/SiO_2/Si_3N_4$)의 터널베리어를 갖는 비휘발성 메모리의 신뢰성 비교

  • 박군호;이영희;정홍배;조원주
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2009년도 추계학술대회 논문집
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    • pp.53-53
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    • 2009
  • Charge trap flash memory devices with modified tunneling barriers were fabricated using the tunneling barrier engineering technique. Variable oxide thickness (VARIOT) barrier and CRESTED barrier consisting of thin $SiO_2$ and $Si_3N_4$ dielectric layers were used as engineered tunneling barriers. The VARIOT type tunneling barrier composed of oxide-nitride-oxide (ONO) layers revealed reliable electrical characteristics; long retention time and superior endurance. On the other hand, the CRESTED tunneling barrier composed of nitride-oxide-nitride (NON) layers showed degraded retention and endurance characteristics. It is found that the degradation of NON barrier is associated with the increase of interface state density at tunneling barrier/silicon channel by programming and erasing (P/E) stress.

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Laboratory Astrophysics using Intense X-ray from Free Electron Lasers

  • Chung, Moses
    • 천문학회보
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    • 제42권2호
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    • pp.65.4-65.4
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    • 2017
  • The laboratory astrophysics is a new emerging field of basic sciences, and has tremendous discovery potentials. The laboratory astrophysics investigates the basic physical phenomena in the astrophysical objects in controlled and reproducible manners, which has become possible only recently due to the newly-established intense photon and ion beam facilities worldwide. In this presentation, we will introduce several promising ideas for laboratory astrophysics programs that might be readily incorporated in the Pohang Accelerator Laboratory X-ray Free Electron Laser (PAL-XFEL). For example, precise spectroscopic measurements using Electron Beam Ion Trap (EBIT) and intense X-ray photons from the PAL-XFEL can be performed to explore the fundamental processes in high energy X-ray phenomena in the visible universe. Besides, in many violent astrophysical events, the energy density of matter becomes so high that the traditional plasma physics description becomes inapplicable. Generation of such high-energy density states can be also be achieved by using the intense photon beams available from the PAL-XFEL.

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다결정 실리콘 박막 트랜지스터 제조공정 기술 (Polycrystalline Silicon Thin Film Transistor Fabrication Technology)

  • 이현우;전하응;우상호;김종철;박현섭;오계환
    • 한국진공학회지
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    • 제1권1호
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    • pp.212-222
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    • 1992
  • To use polycrystalline Si Thin Film Transistor (poly-Si TFT) in high density SRAM instead of High Load Resistor (HLR), TFT is needed to show good electrical characteristics such as large carrier mobility, low leakage current, high driver current and low subthreshold swing. To satisfy these electrical characteristics, the trap state density must be reduced in the channel poly. Technological issues pertinent to the channel poly fabrication process are investigated and discussed. They are solid phase growth (SPG), Si-ion implantation, laser annealing and hydrogenation. The electrical properties of several CVD oxides used as the gate oxide of TFT are compared. The dependence of the electrical characteristics of TFT on source-drain ion-implantation dose, drain offset length and dopant lateral diffusion are also described.

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Polyethylene의 전기적,구조적 성질에 미치는 연신효 (Effect of Elongation on Electrical and Structral Properties of Polyethylene)

  • 박대희;김동욱;임기성;임기조;이동영;한민구
    • 대한전기학회논문지
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    • 제43권4호
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    • pp.601-606
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    • 1994
  • This paper describes the effect of elongation on electrical properties and molecular structrue of high density polyethylene. Thin polyethylene films films obtained dy roll elongation after extruded at 220$^{\circ}C$ and elongated to draw rations of 16. Crystallinity of polyethylene films was measured by X-Ray diffraction and electrical properties were estimated by conductivity and TSC(Thermal Simulated Current). It was foung that the crystallinity increases and the electrical conductivity decreases as the elongation increases. The elongation dependence of electrical conductivity may be explained by the trap density. Thus, the control of polymer structure and crystallinity makes its properties better and can be applicated in order to get more active properties.