• Title/Summary/Keyword: $c_v$

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A Study on the Spontaneous Ignition of Gasoline and Additive of Fuel (Gasoline과 연료첨가제(Cenox)의 자연발화에 관한 연구)

  • Choi, Jae-Wook;Mok, Yun-Soo;Choi, Il-Gon;Jeon, Se-Ho;Lim, Woo-Sub;Min, Chul-Woong
    • Fire Science and Engineering
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    • v.20 no.1 s.61
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    • pp.1-5
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    • 2006
  • The spontaneous ignition of a flammable matter is a crucial factor for the prevention of a fire. The minimum ignition temperatures of Gasoline and Cenox in $1000{\mu}l$ of a sample were determined to be $340.5^{\circ}C\;and\;368.5^{\circ}C$ respectively. In addition when the time taken for ignition was 1.0 sec, the instantaneous ignition temperatures were $416^{\circ}C\;and\;427^{\circ}C$ respectively. Moreover, the changes in the minimum ignition temperature were small when less than 60 v/v% of Cenox was added, but the changes were great when 80 v/v% or more was added. Therefore, it is hypothesized that, when used as a fuel in the Gasoline engine, the ratio of the mixture of Cenox and Gasoline will be a very important factor.

Capacitance-Voltage Characterization of Ge-Nanocrystal-Embedded MOS Capacitors (Ge 나노입자가 형성된 MOS 캐패시터의 캐패시턴스와 전압 특성)

  • Park, Byoung-Jun;Choi, Sam-Jong;Cho, Kyoung-Ah;Kim, Sang-Sig
    • Journal of IKEEE
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    • v.10 no.2 s.19
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    • pp.156-160
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    • 2006
  • Capacitance versus voltage (C-V) curves of Ge-nanocrystal (NC)-embedded MOS capacitors with and without a single capping Al2O3 layer are characterized in this work. C-V curves of the Ge-NC-embedded MOS capacitor with the A12O3 layer are counterclockwise in the voltage sweeps, which indicates tile presence of charge storages in the Ge NCs by the tunnelling of charge carriers between the Si substrate and the Ge NCs. In the Ge-NC-embedded MOS capacitor without Al2O3 layer, clockwise hysteresis of the C-V curves and leftward shifts of the flat band voltages are observed for the embedded MOS capacitor without the Al2O3 layer. It is suggested that the characteristics of the C-V curves are due to the charge trapping at oxygen vacancies within a SiO2 layer. In addition, the illumination of the white light enhances the lower capacitance part of the C-V hysteresis. The origin for the enhancement is discussed in this paper.

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A Literatual Study on the effects of Bloodletting on C.V.A. (중풍(中風)에 활용(活用)된 자락요법(刺絡療法)에 대(對)한 문헌적(文獻的) 고찰(考察))

  • Nam, Chang-Gyoo;Lee, Jin-Seop
    • The Journal of Internal Korean Medicine
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    • v.15 no.2
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    • pp.148-162
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    • 1994
  • A Literature study was done for identifying the effects of Bloodletting on C.V.A. The major results of the study were as follows. 1. The frequency of points of Bloodletting on C.V.A. were in order Twelve well point, Ship son, Gold SalivaJade Fluid, Paekoe, Chungchung, Sugu, Sosang, Taechu, Wijung, Kwanchung, etc. 2. The frequency of meridians of Bloodletting on C.V.A. were in order Extra-point, Tongmaek-kyong, Su-gworum-Shimpo-Kyong, Susoyang-Samcho-Kyong, Sutaeum-Pye-Kyong, Choktaeyang-Panggwang-Kyong. ete. 3. The frequency of the site of points of Bloodletting on C.V.A. were in order four extremities, face, neck and head, etc. 4. The effects of Bloodletting on C.V.A. is clear away heat and alleviate pain, therapy for waking up a patient from unconsciousness, dredge the meridian passage, expel wind-evil and promote blood circulation, emergency treatment for collapse, etc, 5. The effects of Bloodletting on the early stage of C.V.A. were wake up the patient from unconsciousness by clearing away the heat and The effects of Bloodletting on sequence of C.V.A. were dredge the meridian passage, 6. The frequency of points and meridians of Bloodletting on Hemiplegia were in order Twelve well point, Kyonjong, Extra-point, Chok soyang-Tam-Kyong, etc. 7. The frequency of points and meridians of Bloodletting on Aphasia were in order Gold Saliva Jade Fluid, Amun, Extra-point, Tongmaek-Kyong, etc. 8. The frequency of points and meridians of Bloodletting on Quadriplegia were in order Ship son, Twelve well point, Koktaek, Wijung, Extra-point, Chok soyang-Tam-Kyong, etc. 9, The frequency of points and meridians of Bloodletting on Vertigo were in order Four Gods Cleverness, Tuyu. Chanjuk, Paekoe, Taeyang, Extra-point, Yang-Kyong, etc. 10. The frequency of points and meridians of Bloodletting on Headache were in order Taeyang, Paekoe, Taechu, Extra-point, Tongmaek-Kyong, Yang-Kyong, etc. 11. The points and meridians of Bloodletting on Bells palsy were Chichang, Hyopko in Yangmyong-Kyong.

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Integral C-V Converter for a Fully Differential Capacitive Pressure Sensor (완전차동용량형 압력센서를 위한 적분형 C-V 변환기)

  • Lee, Dae-Sung;Kim, Kyu-Chull;Park, Hyo-Derk
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.39 no.9
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    • pp.62-71
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    • 2002
  • An intergral C-V converter is proposed to solve the nonlinearity problem of capacitive pressure sensors. The integral C-V converter consists of a switched-capacitor integrator and a switched-capacitor differential amplifier. It converts the sensor capacitance change which is inversely proportional to an applied pressure into a linear voltage output. Various PSPICE simulations prove that the convertor has excellent characteristics, such as low nonlinearity less than 0.01%/FS and low sensitivity to parallel offset capacitance and parasitic capacitance for the displacement range of sensor diaphragm set to 0 ${\sim}$ 90% of the initial distance between the electrodes in the simulation. We also show that the offset compensation and the gain trimming are easily achieved with the integral C-V converter.

Roof Greening applied a Sallow Green Roof Module System Out of Management - Focused on the Effects on the Growth of Plants by Difference of Soil Mixture Ratio - (식생모듈박스를 이용한 저토심 무관리형 옥상녹화 - 토양 배합비가 식물생육에 미치는 영향을 중심으로 -)

  • Kang, Tai-Ho;Zhao, Hong-Xia;Li, Hong;Kang, Sung-Hoon
    • Journal of the Korean Institute of Landscape Architecture
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    • v.40 no.3
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    • pp.91-98
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    • 2012
  • The objective of this study was to analyze the effects on the growth of Sedum species by different soil in shallow green roof module system, and to find the best soil mixture. The experiment used a module system, 7cm soil depth, five types of soil mixture ratio, and it was carried out on 7th Hoar rooftop in December of 2010. The growth status of the plant showed the most superior of the P5C7P2V1, next P10C1P2V1 and P1P1V1, P1 and C1 showed very poor growth. This result showed that the soil mixture ratio (P5C7P2V1) in green roof module system with minimum management can contribute to the proliferation of rooftop greening in urban settings.

High Performance Control of SRM Drive System for Automobiles by C-dump Converter (C-dump Converter에 의한 차량용 SRM 구동 시스템의 고성능제어)

  • 김도군;윤용호;이태원;원충연;김영렬
    • The Transactions of the Korean Institute of Power Electronics
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    • v.8 no.6
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    • pp.534-542
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    • 2003
  • Small electric motors in an automobile perform various tasks such as engine cooling, pumping, HVAC etc. At present, most of them are DC motors supplied by 12V or 24V batteries. However, DC motors suffer from low efficiency, life cycles and reliability. Therefore, there is a growing interest in substituting DC motors for advanced at motors including switched reluctance motors(SRM). Although there are several other forms SRM convertors, they are either unsatisfactory to the control performance or unsuitable for the 12V battery source. Especially, a conventional asymmetric converter of SRM provides the best flexible and effective control to the current waveform of SRM, but it has the most switches and produces conducting voltage drops across two power switches during SRM operation. For automotive applications with a 12V battery source, this circuit is inadequate. For considering the requirement for effective operation and simple structure of converter in the limited internal circumstance of automobiles, the author inclines toward selecting Modified C-dump converter and Energy efficient c-dump converter.

Fabrications and Properties of MFIS Structures using high Dielectric AIN Insulating Layers for Nonvolatile Ferroelectric Memory (고유전율 AIN 절연층을 사용한 비휘발성 강유전체 메모리용 MFIS 구조의 제작 및 특성)

  • Jeong, Sun-Won;Kim, Gwang-Hui;Gu, Gyeong-Wan
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.38 no.11
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    • pp.765-770
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    • 2001
  • Metal-ferroelectric-insulator- semiconductor(MFTS) devices by using rapid thermal annealed (RTA) LiNbO$_3$/AIN/Si(100) structures were successfully fabricated and demonstrated nonvolatile memory operations. Metal-insulator-semiconductor(MIS) C-V properties with high dielectric AIN thin films showed no hysteresis and good interface properties. The dielectric constant of the AIN film calculated from the capacitance at the accumulation region in the capacitance-voltage(C-V) characteristics was about 8. The C-V characteristics of MFIS capacitor showed a hysteresis loop due to the ferroelectric nature of the LiNbO$_3$ thin films. Typical dielectric constant value of LiNbO$_3$ film of MFIS device was about 23. The memory window width was about 1.2 V at the gate voltage of $\pm$5 V ranges. Typical gate leakage current density of the MFIS structure was the order of 10$^{-9}$ A/$\textrm{cm}^2$ at the range of within $\pm$500 kV/cm. The ferroelectric capacitors showed no polarization degradation up to about 10$^{11}$ switching cycles when subjected to symmetric bipolar voltage pulse(peak-to-peak 8 V, 50 % duty cycle) in the 500 kHz.

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Ferromagnetism of thin films deposited from paramagnetic stainless steel targets by Facing Targets Sputtering

  • Matsushita, N.;Ono, N.;Naoe, M.
    • Proceedings of the Korean Magnestics Society Conference
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    • 1991.05a
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    • pp.73-74
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    • 1991
  • The films with ferromagnetic fine particles dispersed in nonmagnetic matrix, such as $Fe-Al_2O_3$ and Fe-Cu have been studied for use of magnetic recording medium, optically device and sensor. Their magnetic properties depend strongly on structural parameter such as size and volume fraction of ferromagnetic particles. Fe-Cr-Ni alloy sputtered films also have microstructure with ferromagnetic -- b.c.c phase and nonmagnetic f.c.c phase grains. Magnetic properties of these films depend strongly on such a unique structure. These are depend on the ratio in volume of ferromagnetic particles to nonmagnetic ones $V_F/V_N$, the saturation magnetization Ms increased with increase of $V_F/V_N$. The coercivity Hc of the as-deposited films took maximum value of about 200 Oe at adequate $V_F/V_N$ and then Ms and Squareness S were 500 emu/cc and 0.5, respectively.(omitted)

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BTS 측정 분석을 통한 MLCC 소자의 결함 여부 판단

  • Choe, Pyeong-Ho;Kim, Sang-Seop;Choe, Byeong-Deok
    • Proceedings of the Korean Vacuum Society Conference
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    • 2012.08a
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    • pp.298-298
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    • 2012
  • 본 연구에서는 Bias Temperature Stress (BTS) 측정을 통한 다층세라믹커패시터(Multi-Layer Ceramic Capacitor, MLCC) 소자 분석에 대한 연구를 진행하였다. BTS 분석은 소자 내부에 존재하는 Na+, K+ 등의 mobile charge 검출을 위한 방법으로 positive bias와 negative bias stress에 따른 C-V 특성 곡선으로부터 mobile charge의 정량적 해석이 가능하다. 실험 결과 positive bias stress 후의 C-V 특성 곡선이 stress 전 C-V 특성 곡선과 비교해 negative bias 영역으로 0.0376 V 만큼 shift 하였다. 또한 수식(QM = $Cox{\cdot}{\triangle}V$)으로부터 $1.7{\times}1,011$개의 mobile charge가 존재함을 확인하였다. 본 연구는 MLCC 소자 내의 금속 오염물 존재 여부에 따른 소자의 전기적 특성 변화 분석을 위해 진행되었으며, BTS 분석은 반도체 소자 뿐 아니라 본 연구에서와 같이 커패시터 소자의 결함 여부 판단에도 이용 가능함을 확인하였다.

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Capacitance-Voltage (C-V) Characteristics of Cu/n-type InP Schottky Diodes

  • Kim, Hogyoung
    • Transactions on Electrical and Electronic Materials
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    • v.17 no.5
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    • pp.293-296
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    • 2016
  • Using capacitance-voltage (C-V) and conductance-voltage (G/ω-V) measurements, the electrical properties of Cu/n-InP Schottky diodes were investigated. The values of C and G/ω were found to decrease with increasing frequency. The presence of interface states might cause excess capacitance, leading to frequency dispersion. The negative capacitance was observed under a forward bias voltage, which may be due to contact injection, interface states or minority-carrier injection. The barrier heights from C-V measurements were found to depend on the frequency. In particular, the barrier height at 200 kHz was found to be 0.65 eV, which was similar to the flat band barrier height of 0.66 eV.