• Title/Summary/Keyword: V/C

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Synthesis of Silicon Carbide Whiskers (I) : Reaction Mechanism and Rate-Controlling Reaction (탄화규소 휘스커의 합성(I) : 반응기구의 율속반응)

  • 최헌진;이준근
    • Journal of the Korean Ceramic Society
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    • v.35 no.12
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    • pp.1336-1336
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    • 1998
  • A twt -step carbothermal reduction scheme has been employed for the synthesis of SiC whiskers in an Ar or a H2 atmosphere via vapor-solid two-stage and vapor-liquid-solid growth mechanism respectively. It has been shown that the whisker growth proceed through the following reaction mechanism in an Ar at-mosphere : SiO2(S)+C(s)-SiO(v)+CO(v) SiO(v)3CO(v)=SiC(s)whisker+2CO2(v) 2C(s)+2CO2(v)=4CO(v) the third reaction appears to be the rate-controlling reaction since the overall reaction rates are dominated by the carbon which is participated in this reaction. The whisker growth proceeded through the following reaction mechaism in a H2 atmosphere : SiO2(s)+C(s)=SiO(v)+CO(v) 2C(s)+4H2(v)=2CH4(v) SiO(v)+2CH4(v)=SiC(s)whisker+CO(v)+4H2(v) The first reaction appears to be the rate-controlling reaction since the overall reaction rates are enhanced byincreasing the SiO vapor generation rate.

Characteristics of C-V for Double gate MOSFET (Double gate MOSFET의 C-V 특성)

  • 나영일;김근호;고석웅;정학기;이재형
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2003.10a
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    • pp.777-779
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    • 2003
  • In this paper, we have investigated Characteristics of C-V for Double gate MOSFET with main gate and side gate. DG MOSFET has the main gate length of 50nm and the side gate length of 70nm. We have investigated characteristics of C-V and main gate voltage is changed from -5V to +5V. Also we have investigated characteristics of C-V for DG MOSFET when the side gate length is changed from 40nm to 90nm. As the side gate length is reduced, the transconductance is increased and the capacitance is reduced. When the side gate voltage is 3V, we know that C-V curves are bending at near the main gate voltage of 1.8V. We have simulated using ISE-TCAD tool for characteristics analysis of device.

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Relationship between V/C and Accident Rate for Freeway Facility Sections (focused on Shingal-Ansan Freeway) (고속도로 시설물 구간의 교통혼잡도와 사고율의 관계 분석 (신갈-안산 고속도로를 중심으로))

  • Oh, Cheol;Chang, Jae-Nam;Chang, Myeong-Sun
    • Journal of Korean Society of Transportation
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    • v.17 no.2
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    • pp.21-27
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    • 1999
  • The objective of this study is to clarify the relationship between accident rate and V/C for freeway facility. The relationship can be used as a basic reference to predict and prevent traffic accident. The traffic volume and the number of accidents from 1992 to 1997 on Shingal-Ansan Freeway were analyzed in this study to clarify the relationship. Hourly accident rate and V/C were calculated for each facility sections : basic freeway section, tunnel section and toll gate section. The accident rate models consisting of an independent variable of V/C were established by repression analysis and compared with each other. The relationship between accident rates and V/C ratios represented U-shaped pattern for all sections. The result of this study indicates that accident rates are highest in the low hourly V/C range, decrease with increasing V/C ratio, and then increase as the V/C ratio increases. The accident rate of toll gate section is in general higher than that of other sections. Although the accident rate of tunnel section is higher than that of basic freeway section when V/C is above 0.67, there is no significant difference of accident rate between basic freeway and tunnel section when V/C is between 0.5 and 0.8. Basic freeway tunnel and toll gate section have the minimum accident rate when V/C is 0.78, 0.75 and 0.57 respectively.

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Dissolution Behaviors of Sericin in Cocoon Shell on the Fluorescence Colors (누에고치층의 형광색에 따른 Sericin의 용해성)

  • 손승종;남중희
    • Journal of Sericultural and Entomological Science
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    • v.30 no.1
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    • pp.33-39
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    • 1988
  • In the case of white cocoon, the fluorescence colors are classified as a yellowish fluorescence cocoon(Y.F.C.) and a violet fluorescence cocoon(V.F.C.) by exposing to ultra-violet ray. Accordingly, experiments were carried out to investigate the difference of sericin behaviors between Y.F.C. and V.F.C. by measuring the sericin solubility, surface tension and viscosity of the sericin solution. Also, the reelability of two different type of cocoons was investigated in the silk reeling process. The results were summarized as follows; 1. The sericin solubility of Y.F.C. shell is higher than that of V.F.C. shell with the dissolution temperature and time. It is shown that the sericin solubility curves of Y.F.c. and V.F.C. are similar in shape, but the difference of sericin solubility between Y.F.C. and V.F.C. is more significant at higher bath temperature. 2. The initial sericin dissolution curves of Y.F.C. and V.F.C. cocoon shell can be divided by four parts within the range of dissolving time from 5 minutes to 60 minutes. The initial dissolution velocity of Y.F.C. shell is faster than that of V.F.C. but the velocity difference is negligible after 30 minutes of dissolving time. 3. The gelation of V.F.C. sericin solution is faster than that of Y.F.C. at early stage(in the range of 15 minutes to 60 minutes). 4. In the silk reeling process, the reelability of Y.F.C. is better than that of V.F.C. with about 11%. This is mainly due to the higher sericin solubility in Y.F.C. followed by the fast dissolution velocity.

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The electrical properties of a Ti/SiC(4H) sehottky diode (Ti/SiC(4H) 쇼트키 장벽 다이오드의 전기적 특성)

  • 박국상;김정윤;이기암;장성주
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.7 no.3
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    • pp.487-493
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    • 1997
  • Ti/sic(4H) Schottky barrier diodes were fabricated. The donor concentration and the built-in potential obtained by capacitance-voltage(C-V) measurement was about $2.0{\times}10^{15}{\textrm}{cm}^{-3}$ and 0.65 V, respectively. The ideality factor of 1.07 was obtained from the slope of current-voltage(I-V) characteristics at low current density. The breakdown field under the reverse bias voltage was about $1.7{\times}10^3V/{\textrm}{cm}$ and was very high. The barrier height of Ti for SiC(4H) was 0.91 V, which was determined by the analysis of the saturation current-temperature and the C-V characteristics.

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INTRINSIC THEORY OF Cv-REDUCIBILITY IN FINSLER GEOMETRY

  • Salah Gomaa Elgendi;Amr Soleiman
    • Communications of the Korean Mathematical Society
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    • v.39 no.1
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    • pp.187-199
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    • 2024
  • In the present paper, following the pullback approach to Finsler geometry, we study intrinsically the Cv-reducible and generalized Cv-reducible Finsler spaces. Precisely, we introduce a coordinate-free formulation of these manifolds. Then, we prove that a Finsler manifold is Cv-reducible if and only if it is C-reducible and satisfies the 𝕋-condition. We study the generalized Cv-reducible Finsler manifold with a scalar π-form 𝔸. We show that a Finsler manifold (M, L) is generalized Cv-reducible with 𝔸 if and only if it is C-reducible and 𝕋 = 𝔸. Moreover, we prove that a Landsberg generalized Cv-reducible Finsler manifold with a scalar π-form 𝔸 is Berwaldian. Finally, we consider a special Cv-reducible Finsler manifold and conclude that a Finsler manifold is a special Cv-reducible if and only if it is special semi-C-reducible with vanishing 𝕋-tensor.

Potential barrier height of Metal/SiC(4H) Schottky diode (Metal/SiC(4H) 쇼트키 다이오드의 포텐셜 장벽 높이)

  • 박국상;김정윤;이기암;남기석
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.8 no.4
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    • pp.640-644
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    • 1998
  • We have fabricated Sb/SiC(4H) Schottky barrier diode (SBD) of which characteristics compared with that of Ti/SiC(4H) SBD. The donor concentration of the n-type SiC(4H) obtained by capacitance-voltage (C-V) measurement was about $2.5{\times}10 ^{17}{\textrm}cm^{-3}$. The ideality factors of 1.31 was obtained from the slope of forward current-voltage (I-V) characteristics of Sb/SiC(4H) SBD at low current density. The breakdown field of Sb/SiC(4H) SBD under the reverse bias voltage was about $4.4{\times}10^2V$/cm. The built-in potential and the Schottky barrier height (SBH) of Sb/SiC(4H) SBD were 1.70V and 1.82V, respectively, which were determined by the analysis of C-V characteristics. The Sb/SiC(4H) SBH of 1.82V was higher than Ti/SiC(4H) SBH of 0.91V. However, the current density and reverse breakdown field of Sb/SiC(4H) were low as compared with those of Ti/SiC(4H). The Sb/SiC(4H), as well as the Ti/SiC(4H), can be utilized as the Shottky barrier contact for the high-power electronic device.

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Side gate length dependent C-V Characteristic for Double gate MOSFET (Side gate 길이에 따른 Double gate MOSFET의 C-V 특성)

  • 김영동;고석웅;정학기;이종인
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2004.05b
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    • pp.661-663
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    • 2004
  • In this paper, we have investigated characteristics of C-V for double gate MOSFET with main gate and side gate by the variation of side sate length and side gate voltage. Main gate voltage is changed from -5V to +5V. We know that characteristics of C-V is good under the condition of LSG=70nm, VSG=3V, VD=2V. We have analyze characteristics of device by ISE-TCAD.

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Triglyceride Composition of Hazel Nut by HPLC (HPLC에 의한 개암종실중(種實中)의 트리글리세리드 조성(組成)에 관(關)한 연구(硏究))

  • Kim, Mi-Ran;Ko, Young-Su;Chung, Bo-Sup
    • Korean Journal of Food Science and Technology
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    • v.14 no.2
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    • pp.122-124
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    • 1982
  • The triglyceride composition of Korean hazel nut (Corylus heterophylla Fisch. var. Japonica koidz) was determined by high performance liquid chromatography (HPLC) using a $C_{18}$ micro Bondapack column with acetonitril-chloroform-tetrahydrofuran(75 : 15 : 10, v/v/v) and acetonitril-tetrahydrofuran (70 : 30, v/v) solvent mixtures as mobile phase. The triglyceride consisted of 4.14% $C_{38}$, 5.23% $C_{40}$, 10.03% $C_{42}$, 24.02% $C_{44}$, 48.73% $C_{46}$ and 7.85% $C_{48}$ with acetonitril-chloroform-tetrahydrofuran (75 : 15 : 10, v/v/v) mobile phase and 4.51% $C_{38}$, 5.98% $C_{40}$, 11.45% $C_{42}$, 25.14% $C_{44}$ and 52.92% $C_{46}$ with acetonitril-tetrahydrofuran (70 : 30, v/v) mobile phase.

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The Design and implementation of LVC Integrated Architecture Technology building division-level L-V-C Interoperability Training System (사단급 L-V-C연동훈련체계 구축을 위한 LVC통합아키텍쳐기술 설계 및 구현)

  • Won, Kyoungchan;Koo, JaHwan;Lee, Hojun;Kim, Yong-Pil
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.22 no.5
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    • pp.334-342
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    • 2021
  • In Korea, the training is performed through independent environments without interoperability among L-V-C systems. In the L system, training for large units is limited due to civil complaints at the training grounds and road restrictions. The V system is insufficient in training related to tactical training, and the C system lacks practicality due to a lack of combat friction elements. To achieve synchronicity and integration training between upper and lower units, it is necessary to establish a system to ensure integrated training for each unit by interoperating the currently operating L, V, and C systems. The interoperability between the C-C system supports Korea-US Combined Exercise. On the other hand, the actual development of the training system through the interoperability of L, V, and C has not been made. Although efforts are being made to establish the L, V, and C system centering on the Army, the joint composite battlefield and LVC integrated architecture technology are not yet secured. Therefore, this paper proposes a new plan for the future training system by designing and implementing the LVC integrated architecture technology, which is the core technology that can build the L-V-C interoperability training system. In conclusion, a division-level L-V-C interoperability training system can be established in the future by securing the LVC integrated architecture technology.