• 제목/요약/키워드: N-current

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하계 동해에 있어서 대마난류의 북상한계와 변동 (THE NORTHERN BOUNDARY THE TSUSHIMA CURRENT AND ITS FOUCTUATIONS)

  • 홍철훈;조규대
    • 한국해양학회지
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    • 제18권1호
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    • pp.1-9
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    • 1983
  • 1970∼1979년 기간중 하계의 동해에 있어서 대마난류의 북상한계와 연변동을 규명하기 위해서 염분최대를 추적하고, 이값에 대한 deltaT(thermosteric anomaly) 에 관하여 검토했다. 29 N 이북의 동지나해로부터 동해북부해역에 이르기 까지 대마난류의 염분최대치 및 그 층의 낮아지는 경향을 보였으며, 그 층도 얕아졌다. 동해의 대마난류역에서 염분최대가 나타나는 층에 대한 deltaT의 값은 220-260 cl/t 이었다. 240cl/t면상의 34.4 등염선을 지표로하여 조사한 대마난류의 북상한계 는 한국 동해안측에서는 4 N 이남해역으로 한정으며, 동염선은 두가지 형태로 나타났다. 즉 동서방향인한국동해안쪽으로 치우쳐 북상하는 경우와 남남서-북북동 방향인 일본연안쪽으로 북상하는 경우였다.

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Evaluation of Rice Nitrogen Utilization Efficiency under High Temperature and High Carbon Dioxide Conditions

  • Hyeonsoo Jang;Wan-Gyu Sang;Yun-Ho Lee;Hui-woo Lee;Pyeong Shin;Dae-Uk Kim;Jin-Hui Ryu;Jong-Tak Youn
    • 한국작물학회:학술대회논문집
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    • 한국작물학회 2022년도 추계학술대회
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    • pp.168-168
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    • 2022
  • According to the 5th Climate Change Report, global average temperature in 2081~2100 will increase 1.8℃ based on RCP 4.5 and 3.7℃ based on RCP 8.5 from the current climate value (IPCC Working Group I AR5). As temperature is expected to increase due to global warming and the intensity and frequency of rainfall are expected to increase, damage to crops is expected, and countermeasures must be taken. This study intends to evaluate rice growth in terms of nitrogen utilization efficiency according to future climate change conditions. In this experiment, Oryza sativa cv. Shindongjin were planted at the SPAR facility of the NICS in Wanju-gun, Jeollabuk-do on June 10, and were planted and grown according to the standard cultivation method. Cultivation conditions are high temperature, high CO2 (current temperature+4.7℃·CO2 800ppm), high temperature (current temperature+4.7℃·CO2 400ppm), current climate (current tempreture·CO2 400 ppm). Nitrogen was varied as 0, 9, 18 kg/10a. The N content and C/N ratio of all rice leaves, stems, and seeds increased at high temperature, and the N content and C/N ratio decreased under high temperature and high CO2 conditions com pared to high temperature. Compared to the current climate, NUE increases by about 8% under high temperature and high CO2 conditions and by about 2% under high temperature conditions. This seems to be because the increase in temperature and CO2 induced the increase in biomass. ANUE related to yield decreased by about 70% compared to the current climate under high temperature conditions, and decreased by about 45% at high temperature and high CO2, showing a tendency to decrease compared to high temperature. This appears to be due to reduced fertility and poor ripening due to high temperature stress. However, as the nitrogen increased, the number of ears and the number of grains increased, slightly offsetting the production reduction factor.

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Device Characteristics of AlGaN/GaN MIS-HFET using $Al_2O_3$ Based High-k Dielectric

  • Park, Ki-Yeol;Cho, Hyun-Ick;Lee, Eun-Jin;Hahm, Sung-Ho;Lee, Jung-Hee
    • JSTS:Journal of Semiconductor Technology and Science
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    • 제5권2호
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    • pp.107-112
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    • 2005
  • We present an AlGaN/GaN metal-insulator-semiconductor-heterostructure field effect transistor (MIS-HFET) with an $Al_2O_3-HfO_2$ laminated high-k dielectric, deposited by plasma enhanced atomic layer deposition (PEALD). Based on capacitance-voltage measurements, the dielectric constant of the deposited $Al_2O_3-HfO_2$ laminated layer was estimated to be as high as 15. The fabricated MIS-HFET with a gate length of 102 m exhibited a maximum drain current of 500 mA/mm and maximum tr-ansconductance of 125 mS/mm. The gate leakage current was at least 4 orders of magnitude lower than that of the reference HFET. The pulsed current-voltage curve revealed that the $Al_2O_3-HfO_2$ laminated dielectric effectively passivated the surface of the device.

Residual magnetic field profiles and their current density profiles of coated conductors for fast and slow cut-off current operations

  • Sun, J.;Tallouli, M.;Shyshkin, O.;Hamabe, M.;Watanabe, H.;Chikumoto, N.;Yamaguchi, S.
    • 한국초전도ㆍ저온공학회논문지
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    • 제17권1호
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    • pp.17-20
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    • 2015
  • Coated conductor is an important candidate for power cable applications due to its high current density. Even for DC power cable transmission, we must study the transport properties of HTS tapes after slow and fast discharge. In order to evaluate relation of the magnetic field with applied current we developed a scanning magnetic field measurements system by employing a Hall probe. This work presents the measurements of the magnetic fields above a coated conductor by varying applied current pattern. In the work, a transport current of 100 A, less than the critical current, is applied to YBCO coated conductor. We measured the residual magnetic field distributions after cut off the transport current with slow and fast operations. The results show differences of the magnetic field profiles and the corresponding current profiles by an inverse solution from the magnetic field measurement between these two operations because of the hysteresis of coated conductor excited by the transport current.

GaN E-HEMT for the next era of power conversion

  • Bailley, Charles
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 2017년도 전력전자학술대회
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    • pp.564-576
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    • 2017
  • ${\cdot}$ GaN E-HEMT provides superior performance vs. Si MOSFET or IGBT, and also superior performance vs. SiC, below ~1200V ${\cdot}$ GaN E-HEMT is replacing Si MOSFET and IGBT in major application segments, and Industry Adoption will accelerate ${\cdot}$ Technology advances in GaN E-HEMT have made high-current true Normally-Off devices available in current ranges from 7A to 250A ${\cdot}$ While GaN has improved Properties vs. SiC or Si, different types of GaN devices offer different levels of performance or robustness ${\cdot}$ JEDEC Industrial-Grade Qualification of GaN E-HEMTs has been achieved, and Automotive Qualification is in progress.

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$N_2$ 플라즈마를 이용한 TFT-FRAM용 $SiN_x$ 버퍼층의 특성 개선 (Improved SiNx buffer layer by Using the $N_2$ Plasma Treatment for TFT-FRAM applications)

  • 임동건;양계준;이준신
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2003년도 추계학술대회 논문집 Vol.16
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    • pp.360-363
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    • 2003
  • In this paper, we investigated SiNx film as a buffer layer of TFT-FRAM. Buffer layers were prepared by two step process of a $N_2$ plasma treatment and subsequent $SiN_x$ deposition. By employing $N_2$ plasma treatment, interface traps such as mobile charges and injected charges were removed, hysteresis of current-voltage curve disappeared. After $N_2$ plasma treatment, a leakage current was decreased about 2 orders. From these results, it is possible to perform the plasma treating process to make a good quality buffer layer of MFIS-FET or capacitor as an application of non-volatile memory.

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O2 분위기에서 p-GaN 층의 Mg 활성화가 GaN계 녹색 발광소자에 미치는 전류-전압특성 (The Influence of the Mg-doped p-GaN Layer Activated in the O2 Ambient on the Current-Voltage Characteristics of the GaN-Based Green LEDs)

  • 윤창주;배성준
    • 한국전기전자재료학회논문지
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    • 제15권5호
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    • pp.441-448
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    • 2002
  • The electrical properties of the GaN-based green light emitting diodes(LEDs) with the Mg-doped p-GaN layer activated in $N_2$ or $O_2$ ambient have been compared. For the $N_2$ -ambient activation the current-voltage behavior of LEDs has been found to be improved when the Mg dopants activation was performed in the higher temperature. However, for the $O_2$-ambient activation the current-voltage characteristic has been observed to be enhanced when the Mg dopants activation was carried out in the lower temperature. The minimum forward voltage at 20mA was obtained to be 4.8 V for LEDs with the p-GaN layer activated at $900^{\circ}C$ in the $N_2$ ambient and 4.5V for LEDs with the p-GaN layer treated at $700^{\circ}C$ in the $O_2$ambient, repectively. The forward voltage reduction of the LEDs treated in the $O_2$-ambient may be related to the oxygen co-doping of the p-GaN layer during the activation process. The $O_2$ -ambient activation process is useful for the enhancement of the LED performance as well as the fabrication process since this process can activate the Mg dopants in the low temperature.

정상성인에서 러시안 전류와 저주파 전류 자극에 의한 근력 증가의 비교 (A Comparison of Muscle Strength by Russian Current and Low Frequency Current Stimulation in Normal Adult)

  • 김종열
    • 대한물리의학회지
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    • 제6권3호
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    • pp.353-360
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    • 2011
  • Purpose : The purpose of this study was to compare the effect of muscle strength by stimulation of russian current and low frequency. Methods : The subjects were thirty young healthy volunteers who were divided into two groups including russian current group(n=15) and low frequency group(n=15). The intervention was applied totally 12 times (1 time, 10 minute) for 4weeks in each group. The peak torque and average power were measured and analysed using Biodex system 4 before the treatment, after 2 weeks, 4 weeks. Results : As a result, russians currents and low frequency stimulation increased significantly average power and peak torque with the lapse of time. However, there were not significant differences of the average power and peak torque between the groups in all periods. Conclusion : In conclusion, russians currents and low frequency stimulation had no differences in the increase of muscle strength.

DCM Frequency Control Algorithm for Multi-Phase DC-DC Boost Converters for Input Current Ripple Reduction

  • Joo, Dong-Myoung;Kim, Dong-Hee;Lee, Byoung-Kuk
    • Journal of Electrical Engineering and Technology
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    • 제10권6호
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    • pp.2307-2314
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    • 2015
  • In this paper, a discontinuous conduction mode (DCM) frequency control algorithm is proposed to reduce the input current ripple of a multi-phase interleaved boost converter. Unlike conventional variable duty and constant frequency control, the proposed algorithm controls the switching frequency to regulate the output voltage. By fixing the duty ratio at 1/N in the N-phase interleaved boost converter, the input current ripple can be minimized by ripple cancellation. Furthermore, the negative effects of the diode reverse recovery current are eliminated because of the DCM characteristic. A frequency controller is designed to employ the proposed algorithm considering the magnetic permeability change. The proposed algorithm is analyzed in the frequency domain and verified by a 600 W three-phase boost converter prototype that achieved 57% ripple current reduction.

PNP 게이트를 가지는 폴리 실리콘 박막 트랜지스터의 전기적 특성 (Electrical characteristics of polysilicon thin film transistors with PNP gate)

  • 민병혁;박철민;한민구
    • 전자공학회논문지A
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    • 제33A권3호
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    • pp.96-106
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    • 1996
  • One of the major problems for poly-Si TFTs is the large off state leakage current. LDD (lightly doped drain) and offset gated structures have been employed in order to reduce the leakage current. However, these structures also redcue the oN current significantly due to the extra series resistance caussed by the LDD or offset region. It is desirable to have a device which would have the properties of the offset gated structure in the OFF state, while behaving like a fully gated device in the oN state. Therefore, we propose a new thin film transistor with pnp junction gate which reduce the leakage curretn during the OFF state without sacrificing the ON current during the ON state.

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