• Title/Summary/Keyword: Field trapping

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Evaluation of Pheromone Trap Settings for Managing Brinjal Shoot and Fruit Borer (Leucinodes orbonalis) in Brinjal

  • Rahman, Mizanur;Ali, Razzab;Islam, Mohammad Saiful;Wang, Myeong-Hyeon
    • Korean Journal of Plant Resources
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    • v.22 no.3
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    • pp.220-226
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    • 2009
  • An experiment was conducted to find out among 9 trap settings the most appropriate site for trap placement in the Brinjal field based on Brinjal shoot and fruit borer trapping efficiency, shoot and fruit infestation, healthy and total fruit yield, and BCR. The efficiency of different trap setting positions varied significantly. Trapping efficiency observed the $T_{1}$ ensured the minimum shoot and fruit infestation 10.02% and 20.95%, respectively, minimum infested fruit yield (4.75 ton/ha), maximum healthy and total fruit yield (26.72 and 31.47 ton/ha) and the maximum BCR (1.70), which was followed by $T_{2}$ and $T_{4}$. The minimum trapping efficiency of $T_{9}$ treatment led the maximum shoot and fruit infestation 13.89 and 29.26%, respectively, maximum infested fruit yield (7.59 ton/ha), minimum healthy and total fruit yield (17.74 and 25.32 ton/ha) and the minimum BCR (1.00). A correlation between the number of BSFB adults trapped from the most efficient trap setting and the shoot and fruit infestation recorded and found a linear positive correlation between number of BSFB adults trapped and shoot infestation (r = 0.781) and fruit infestation (r = 0.810). The effect of pheromone trap positions observed in this study may be attributed to the easy accessibility of the lures and traps, when they are placed at the canopy.

Biological Control of Root-Lesion Nematodes(Pratylenchus spp.) by Nematode-Trapping Fungi (선충 포식성 곰팡이를 이용한 뿌리썩이선충(Pratylenchus spp.)의 생물학적 방제)

  • 손흥대;김성렬;최광호;추호렬
    • Journal of Life Science
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    • v.10 no.4
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    • pp.403-407
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    • 2000
  • For the biological control of the root-lesion nematodes, Pratylenchus spp., which damage directly and indirectly to the leaf perilla, the nematical effect of three nematode-trapping fungi, Arthrobotrys oligospora, A. conoides and A. dactyloides was evaluated in the field. Three species of Arthrobotrys were isolated from the culture soil of leaf perilla in 1998 and were observed the capture of the root-lesion nematodes, Pratylenchus spp. by adhesive hyphal networks or constricting rings on agar. At 40 days after treatment, the plant-parasitic nematodes and root-lesion nematode populations were approximately increased 3.5 fold in untreated control plot, while the nematode population in fungi treatment plots was similar to initial population. In the A. dactyloides plot, however, the population of plant-parasitic nematodes and Pratylenchus spp. was approximately reduced 65% and 53%, respectively. Thus, the fungus A. dachyloides should provide as biological agent for the control of Pratylenchus spp.

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Trapping centers due to native defects in the $CdIn_2S_4$ films grown by hot wall epitaxy

  • Hong, Myung-Seuk;Hong, Kwang-Joon
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2007.11a
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    • pp.167-168
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    • 2007
  • $CdIn_2S_4$ (110) films were grown on semi-insulating GaAs (100) by a hot wall epitaxy method. Using photocurrent (PC) measurement, the PC spectra in the temperature range of 30 and 10 K appeared as three peaks in the short wavelength region. It was found that three peaks, A-, B-, and C-excitons, correspond to the intrinsic transition from the valence band states of ${\Gamma}_4(z),\;{\Gamma}_5(x),\;and\;{\Gamma}_5(y)$ to the exciton below the conduction band state of ${\Gamma}_1(s)$, respectively. The 0.122 eV crystal field splitting and the 0.017 eV spin orbit splitting were obtained. Thus, the temperature dependence of the optical band gap obtained from the PC measurement was well described by $E_g$(T)=2.7116eV - $(7.65{\times}10^{-4}\;eV/K)T^2$/(425+T). But, the behavior of the PC was different from that generally observed in other semiconductors. The PC intensities decreased with decreasing temperature. This phenomenon had ever been reported at a PC experiment on the bulk crystals grown by the Bridgman method. From the relation of log $J_{ph}$ vs 1/T, where $J_{ph}$ is the PC density, two dominant levels were observed, one at high temperatures and the other at low temperatures. Consequently, the trapping centers due to native defects in the $CdIn_2S_4$ film were suggested to be the causes of the decrease in the PC signal with decreasing temperature.

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Analysis of Positive Bias Temperature Instability Degradation Mechanism in n+ and p+ poly-Si Gates of High-Voltage SiO2 Dielectric nMOSFETs (고전압 SiO2 절연층 nMOSFET n+ 및 p+ poly Si 게이트에서의 Positive Bias Temperature Instability 열화 메커니즘 분석)

  • Yeohyeok Yun
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.16 no.4
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    • pp.180-186
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    • 2023
  • Positive bias temperature instability (PBTI) degradation of n+ and p+ poly-Si gate high-voltage(HV) SiO2 dielectric nMOSFETs was investigated. Unlike the expectation that degradation of n+/nMOSFET will be greater than p+/nMOSFET owing to the oxide electric field caused by the gate material difference, the magnitude of the PBTI degradation was greater for the p+/nMOSFET than for the n+/nMOSFET. To analyze the cause, the interface state and oxide charge were extracted for each case, respectively. Also, the carrier injection and trapping mechanism were analyzed using the carrier separation method. As a result, it has been verified that hole injection and trapping by the p+ poly-Si gate accelerates the degradation of p+/nMOSFET. The carrier injection and trapping processes of the n+ and p+ poly-Si gate high-voltage nMOSFETs in PBTI are detailed in this paper.

A Study on the Electrical Conduction in Insulation Material with High Voltage Treatment (고전계인가 고분자 절연재료의 전도현상에 관한 연구)

  • 임헌찬;정재희;이덕출
    • Journal of the Korean Society of Safety
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    • v.9 no.1
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    • pp.56-60
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    • 1994
  • In this study, Cuttent vs. Temperature characteristics of polyethylene with high-voltage treatment and crystallinity have been studied. The current curve( $I_{th}$) shows two peaks at 85 ($^{\circ}C$) and 50($^{\circ}C$), respectively. Trapping of carriers Proceeds during the high-field treatment, and it Is clear that 1th arises from the drift of carriers under the external voltage( $V_{b}$). From the results of TSC of BDPE and LDPE. It is realized that the traps are relation to the crystallinity.y.y.

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Electrical Characteristics of Thin Film Transistor According to the Schottky Contacts (쇼키컨텍에 의한 박막형 트랜지스터의 전기적 특성)

  • Oh, Teresa
    • Korean Journal of Materials Research
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    • v.24 no.3
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    • pp.135-139
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    • 2014
  • To obtain the transistor with ambipolar transfer characteristics, IGZO/SiOC thin film transistor was prepared on SiOC with various polarities as a gate insulator. The interface between a channel and insulator showed the Ohmic and Schottky contacts in the bias field of -5V ~ +5V. These contact characteristics depended on the polarities of SiOC gate insulators. The transfer characteristics of TFTs were observed the Ohmic contact on SiOC with polarity, but Schottky contact on SiOC with low polarity. The IGZO/SiOC thin film transistor with a Schottky contact in a short range bias electric field exhibited ambipolar transfer characteristics, but that with Ohmic contact in a short range electric field showed unipolar characteristics by the trapping phenomenon due to the trapped ionized defect formation.

Electromagnetic Properties of BiPbSrCaCuO Superconductor (BiPbSrCaCuO 초전도체의 전자기특성)

  • 이상헌
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.17 no.7
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    • pp.788-792
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    • 2004
  • The Electromagnetic properties in BiPbSrCaCuO superconductor was studied. In the measurement of current-voltage characteristics, a voltage across the superconducting sample was observed on applying an external magnetic field. The voltage continues to appear the removal of the magnetic field. The appearance of the voltage is ascribed to the trapping of magnetic flux. Depanding on the direction of appied magnetic flux less than $2.5\times{10}^-5$ T, the voltage in the magnetized sample increases or decreases. It is considered that mechanism of voltage occurrence can be explained by applying filament model.

Orientation of Liquid Crystal and Electro-Optic Characteristic Effect of dispersed Carbon nanotubes in In Plane Switching Cell (탄소 나노 튜브가 분산된 수평전기장을 이용한 액정 셀의 액정 방향성과 전기 광학특성 연구)

  • Jeon, Sang-Youn;Baik, In-Su;Lee, Seung-Hee
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2005.07a
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    • pp.520-521
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    • 2005
  • To observe the orientation of carbon nanotubes (CNTs) dispersed in nematic liquid crystal (NLC), CNT-doped homogeneously-aligned NLC cells driven by in-plane field was fabricated. The CNTs were aligned with a LC director in the initial state, whereas the CNTs disturbed the LC director above critical ac field. We observed motional textures in the form of vertical stripes in the local area between electrodes, which were associated with a deformation of the LC director orientation. This suggests that CNTs start to vibrate three dimensionally with translational motion. The hysteresis studies of voltage-dependent transmittance under dc electric field show that the amount of residual dc is greatly reduced due to ion trapping by CNT.

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Dynamic Motion of Polyelectrolyte in a Composite Membrane: II. Molecular Study (막에서 전하고분자의 동적 현상 II. 미시적 연구)

  • Park, Young;Lim, Hwa A.
    • Membrane Journal
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    • v.4 no.2
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    • pp.96-105
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    • 1994
  • Theoretical model for membrane transport of large polye!ectroiyte is presented. When the electric field is applied, the molecular conformation quickly orients in the field direction showing overshooting orientation. the predicted dependence of overshoot time and orientation upon field intensity and molecular size aids to understand the dynamic motion of molecules in membrane transport. The dynamics of the overshoot is associated with self-trapping conformations of molecule. The understanding of these effects supports evidences for the electrophoretic filtration of polydectrolyte in the polymeric membrane. This paper shows one example for molecular study in the theoretical review paper of membrane transport.

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4H-SiC Planar MESFET for Microwave Power Device Applications

  • Na, Hoon-Joo;Jung, Sang-Yong;Moon, Jeong-Hyun;Yim, Jeong-Hyuk;Song, Ho-Keun;Lee, Jae-Bin;Kim, Hyeong-Joon
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.5 no.2
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    • pp.113-119
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    • 2005
  • 4H-SiC planar MESFETs were fabricated using ion-implantation on semi-insulating substrate without recess gate etching. A modified RCA method was used to clean the substrate before each procedure. A thin, thermal oxide layer was grown to passivate the surface and then a thick field oxide was deposited by CVD. The fabricated MESFET showed good contact properties and DC/RF performances. The maximum oscillation frequency of 34 GHz and the cut-off frequency of 9.3 GHz were obtained. The power gain was 10.1 dB and the output power of 1.4 W was obtained for 1 mm-gate length device at 2 GHz. The fabricated MESFETs showed the charge trapping-free characteristics and were characterized by the extracted small-signal equivalent circuit parameters.