• 제목/요약/키워드: $V_{th}$

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고체 고분자 전해질을 사용한 $V_{6}O_{13}$ Composite/Li Cell의 충방전 특성 (Charge/discharge Properties of $V_{6}O_{13}$ Composite/Li Cell with Solid Polymer Electrolyte)

  • 김종욱;유영한;정인성;박복기;구할본;문성인
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1996년도 하계학술대회 논문집 C
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    • pp.1414-1417
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    • 1996
  • The purpose of this study Is to research and develop $V_{6}O_{13}$ composite cathode for lithium thin film battery. $V_{6}O_{13}$ represents a class of cathode active material used in Li rechargeable batteries. In this study, we investigated cyclic voltammetry and charge/discharge characteristics of $V_6O_{13}$/SPE/Li cells. Cyclic voltammogram of $V_{6}O_{13}$/SPE/Li cell at scan rate 1mV/sec showed reduction peaks of 2.25V and 2.4V and oxidation peaks of 2.4V and 2.2V. The discharge curve of $V_{6}O_{13}$/SPE/Li cell showed 4 potential plateaus. The discharge capacity was decreased in the beginning of charge/discharge cycling. After 8th cycling, the discharge capacity was stable. The discharge capacity of 1st cycle and 15th cycle was 290mAh/g and 147mAh/g at $25^{\circ}C$, respectively.

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뇌졸중(腦卒中)에 관(關)한 임상통계적(臨床統計的) 연구(硏究) (Clinical Observation on C.V.A.)

  • 윤진구;조기호;김영석;이경섭
    • 대한한방내과학회지
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    • 제10권1호
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    • pp.25-38
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    • 1989
  • Clinical observation was done on 1092 cases of cerebrovascular disease which were confirmed by Brain CT scan in Oriental Medical Hospital in Kyung Hee Univ. from May 1987 to May 1988. Specially, clinical prognosis of 250 patients who had been hospitalized for over 4 weeks, were obserbed. The results were obtained as follows; 1. In this study, Occlusive CVD was 77.9%, Cerebral hemorrhage was 18.8%, Subarachnoid hemonhage was 0.8%. 2. The ratio of male to female was 1.4:1. In the age distribution, 60th decade, 50th decade, 40th decade, 30th's, 20th's were in order of frequency and specially 60th decade was 35.53% over 70th decade was 17.1% in ratio. 3. The most common preceding disease of CVD was hypertension (54.21%) and diabetes mellitus (19.96%) was second. 4. Almost, the duration of hospitalization was 2-4 weeks in 34.8%, within 4 weeks in 78.02%. 5. Primary attack was 75.7%, 2nd attack was 17.9%, over 3rd attack was 3.1% in ratio of recurrence. 6. The level of consciousness was Grade I in 96.4%, Grade II in 3.2%, Grade III in 1% at attack. 7. A few complications of C.V.A. were observed in the studies: pneumonia was noted frequently in 3.2%, bed sore, urinary tract infection, gastro intestinal bleeding in order of frequency. 8. The ratio of neurologic deficiency in occlusive CVD decreased from 51.9% to 29.3% in upper limb, 52.6% to 24.4% in lower limb, and that in cerebral hemorrhage decreased from 69.5% to 25% in upper limb, 50% to 20% in lower limb. 9. The ratio of left side hemiplegia to right was 1.04:1 in male, 1:1.18 in female. 10. The herb medications for C.V.A. were various Chungg-Paesagantang, Sunghanggeonggisan were used most frequently to Chungyeold, Geopung, Soongi, Haldam and Chungsimtang, the drugs for Bogiheol were used as discharge. In these oriental medical therapy of C.V.A. objective diagnosis and more various therapeutic method must be obtained through east-west medical co-operation.

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Daily Life of the People of Kashgaria at the End of the 19th Century: Evidence of Russian Traveler M.V. Pevtsov

  • MUSTAFAYEV, Shahin
    • Acta Via Serica
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    • 제7권1호
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    • pp.1-28
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    • 2022
  • The province of the People's Republic of China, the Xinjiang Uygur Autonomous Region has historically been known under various names - Eastern Turkestan, Chinese Turkestan, Kashgaria, etc. In the early 19th century this region was one of the least explored in Western scholarship and for the influence over which the so-called 'Great Game', geopolitical rivalry between Great Britain and the Russian Empire, gradually unfolded. This rivalry was one of the significant factors stimulating increased interest in an in-depth and comprehensive study of the geography, nature, and population of Kashgaria. Accordingly, in the second half of the 19th to early 20th centuries, several expeditions were organized that pursued serious academic goals alongside military, diplomatic, and commercial purposes. One of these expeditions, organized by the Imperial Russian Geographical Society, was the so-called 'Tibetan expedition' led by a talented scientist and military figure M.V. Pevtsov in 1889-90. The expedition followed the routes of Eastern Turkestan, the northern outskirts of the Tibetan Plateau, and Dzungaria studying this vast region's geography, topography, nature, climate, and population. The results of this investigation were presented by M.V. Pevtsov in a detailed and comprehensive report published in St. Petersburg in 1895. An important part of this narrative is the so-called "Ethnographic Essay of Kashgaria," which reflects the author's observations and thoughts on this region's ethnic composition, religious beliefs, language, customs, and rituals. This article offers insights and analysis of the content of Pevtsov's report, which provides valuable information about the daily life of the population of Kashgaria at the end of the 19th century to an English-speaking audience.

Temperature-Dependent Instabilities of DC characteristics in AlGaN/GaN-on-Si Heterojunction Field Effect Transistors

  • Keum, Dong-Min;Choi, Shinhyuk;Kang, Youngjin;Lee, Jae-Gil;Cha, Ho-Young;Kim, Hyungtak
    • JSTS:Journal of Semiconductor Technology and Science
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    • 제14권5호
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    • pp.682-687
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    • 2014
  • We have performed reverse gate bias stress tests on AlGaN/GaN-on-Si Heterostructure FETs (HFETs). The shift of threshold voltage ($V_{th}$) and the reduction of on-current were observed from the stressed devices. These changes of the device parameters were not permanent. We investigated the temporary behavior of the stressed devices by analyzing the temperature dependence of the instabilities and TCAD simulation. As the baseline temperature of the electrical stress tests increased, the changes of the $V_{th}$ and the on-current were decreased. The on-current reduction was caused by the positive shift of the $V_{th}$ and the increased resistance of the gate-to-source and the gate-to-drain access region. Our experimental results suggest that electron-trapping effect into the shallow traps in devices is the main cause of observed instabilities.

A Light-induced Threshold Voltage Instability Based on a Negative-U Center in a-IGZO TFTs with Different Oxygen Flow Rates

  • Kim, Jin-Seob;Kim, Yu-Mi;Jeong, Kwang-Seok;Yun, Ho-Jin;Yang, Seung-Dong;Kim, Seong-Hyeon;An, Jin-Un;Ko, Young-Uk;Lee, Ga-Won
    • Transactions on Electrical and Electronic Materials
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    • 제15권6호
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    • pp.315-319
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    • 2014
  • In this paper, we investigate visible light stress instability in radio frequency (RF) sputtered a-IGZO thin film transistors (TFTs). The oxygen flow rate differs during deposition to control the concentration of oxygen vacancies, which is confirmed via RT PL. A negative shift is observed in the threshold voltage ($V_{TH}$) under illumination with/without the gate bias, and the amount of shift in $V_{TH}$ is proportional to the concentration of oxygen vacancies. This can be explained to be consistent with the ionization oxygen vacancy model where the instability in $V_{TH}$ under illumination is caused by the increase in the channel conductivity by electrons that are photo-generated from oxygen vacancies, and it is maintained after the illumination is removed due to the negative-U center properties.

Monte Carlo Simulation Study: the effects of double-patterning versus single-patterning on the line-edge-roughness (LER) in FDSOI Tri-gate MOSFETs

  • Park, In Jun;Shin, Changhwan
    • JSTS:Journal of Semiconductor Technology and Science
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    • 제13권5호
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    • pp.511-515
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    • 2013
  • A Monte Carlo (MC) simulation study has been done in order to investigate the effects of line-edge-roughness (LER) induced by either 1P1E (single-patterning and single-etching) or 2P2E (double-patterning and double-etching) on fully-depleted silicon-on-insulator (FDSOI) tri-gate metal-oxide-semiconductor field-effect transistors (MOSFETs). Three parameters for characterizing the LER profile [i.e., root-mean square deviation (${\sigma}$), correlation length (${\zeta}$), and fractal dimension (D)] are extracted from the image-processed scanning electron microscopy (SEM) image for each photolithography method. It is experimentally verified that two parameters (i.e., ${\sigma}$ and D) are almost the same in each case, but the correlation length in the 2P2E case is longer than that in the 1P1E case. The 2P2E-LER-induced $V_TH$ variation in FDSOI tri-gate MOSFETs is smaller than the 1P1E-LER-induced $V_TH$ variation. The total random variation in $V_TH$, however, is very dependent on the other major random variation sources, such as random dopant fluctuation (RDF) and work-function variation (WFV).

액상 반응에 의해 합성한 리튬코발트산화물을 이용한 Lithium ion 2차전지의 충방전 특성 (Charge-discharge Behaviour of Lithium Ion Secondary Battery Using LiCo$O_2$ Synthesized by a Solution Phase Reaction)

  • 김상필;조정수;박정후;윤문수;심윤보
    • 한국전기전자재료학회논문지
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    • 제11권11호
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    • pp.1049-1054
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    • 1998
  • The LiCo$O_2$ powder was synthesized by a solution phase reaction. This shows a high (003) peak intensity and low (104) or (101) peak intensities in X-ray diffraction spectra. The LiCo$O_2$/Li cell shows an initial discharge capacity of 102.9mAh/g and an average discharge potential or 3.877V at a current density of 50mA/g between 3.0~4.2V. The peaks of dQ/dV plot are associated with Li ion intercalation/deintercalation reaction. To evaluate the cycleability of an actual battery system, cylindrical lithium ion cell was manufactured using graphitized MPCF anode and LiCoO$_2$ cathode. After 100th cycle, this cel maintains 80% capacity of 10th cycle value. The LiCoO$_2$/MPCF cell has a high discharge voltage of 3.6~3.7V and a good cycle life performance on cycling between 4.2~2.7V.

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P형 짧은 채널(L=1.5 um) 다결정 실리콘 박막 트랜지스터의 오프 상태 스트레스 하에서의 신뢰성 분석 (Positive Shift of Threshold Voltage in short channel (L=$1.5{\mu}m$) P-type poly-Si TFT under Off-State Bias Stress)

  • 이정수;최성환;박상근;한민구
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2009년도 제40회 하계학술대회
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    • pp.1225_1226
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    • 2009
  • 유리 기판 상에 이중 게이트 절연막을 가지는 우수한 특성의 P형 엑시머 레이저 어닐링 (ELA) 다결정 실리콘 박막 트랜지스터를 제작하였다. 그리고 P형 짧은 채널 ELA 다결정 실리콘 박막 트랜지스터의 오프 상태 스트레스 하에서의 전기적 특성을 분석하였다. 스트레스하에서 긴 채널에서의 문턱 전압은 양의 방향으로 거의 이동하지 않는 (${\Delta}V_{TH}$ = 0.116V) 반면, 짧은 채널 박막 트랜지스터의 문턱 전압은 양의 방향으로 상당히 이동 (${\Delta}V_{TH}$ = 2.718V)하는 것을 확인할 수 있었다. 이런 짧은 채널 박막 트랜지스터에서 문턱 전압의 양의 이동은 다결정 실리콘 막과 게이트 산화막 사이의 계면에서의 전자 트랩핑 때문이다. 또한, 박막 트랜지스터의 누설 전류는 오프 상태 스트레스 하에서의 채널 영역의 홀 전하로 인하여 온 전류 수준을 감소시키지 않고 억제될 수 있었다. C-V 측정 결과는 계면의 전자 트랩핑이 드레인 접합 영역부근에서 발생한다는 것을 나타낸다.

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Electrical properties and thermal stability of oxygen incorporated GeSbTe films

  • 장문형;박승종;임동혁;박성진;조만호;조윤호;이종흔
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2009년도 제38회 동계학술대회 초록집
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    • pp.155-155
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    • 2010
  • Oxygen incorporated $Ge_2Sb_2Te_5$ (GST) films were prepared by an ion beam sputtering deposition (IBSD) method. From the I-V curves, the $V_{th}$ value varies with the oxygen content. Ge-deficient hexagonal phases are responsible for the observed unstability and decrease in $V_h$ values. In the case of a GST film with an elevated oxygen content of 30.8 %, the GST layer melted at 9.02 V due to the instability conferred by the high oxygen content. The formation of Ge-deficient hexagonal phases such as $GeSb_2Te_4$ and $Sb_2Te_3$ appear to be responsible for the $V_{th}$ variation. Impedance analyses indicated that the resistance in GST films with oxygen contentsof 16.7 % and 21.7 % had different origins. Thermal desorption spectroscopy (TDS)data indicate that moisture and hydrocarbons were more readily desorbed at higher oxygen content because the oxygen incorporated GST films are more hydrophilic than undoped GST films.

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"한진인천"호 침몰종의 원인에 관한 이론적인 연구 (A Theoretical Study on the Causes of the Sinking Disaster of M/V Hanjin-Inchon)

  • 윤점동;권종호;주재훈;허용범;윤순동
    • 한국항해학회지
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    • 제11권2호
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    • pp.33-52
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    • 1987
  • The disasters of wet bound vessels have been more frequent than those of east bound ones on the sea routes of the North Pacific Ocean in winter season. M/V Hanjin-Inchon was also west bound in her missing voyage. The container vessel of 17, 676 gross tons, M/V Hanjin-Inchon owned by Hanjin Shipping Co.Ltd in Seoul Korea left seattle in west coast of U.S.A for Pusan , Korea on the 5th Feb., 1987 and sailed along the exact courses recommended by Ocean Routes until she reported her position and speed as 49-30N, 158-00E and 8 knots to her head office in Seoul by this ship's time 2200 hours on the 13th Feb., 1987. The above message turned out to be last message from her because she had been missing since then leaving no message but only two life boats of her name, three containers cases, large scale of oil slicks and the corpse of her 3rd mate drifting on the sea near the position reported by her last message.

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