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41.
This is part II of a two part paper dealing with control design in power systems using the normal forms technique. The companion paper (part I) describes the general theory and control procedure. Also, the proposed procedure was applied to the Base Case of the 50-generator IEEE Test System. This paper depicts the case studies to show the validation of the proposed method and to observe the effects of controller setting changes. In addition the results dealing with the design of the controller are given and verification of the controller design using nonlinear time simulation is provided 相似文献
42.
As bipolar junction transistors (BJTs) are scaled down, the current density increases and base pushout may happen. To prevent base widening, the collector doping concentration is increased; therefore, this increases the electric field in the base-collector junction. In the active operation of BJTs, impact ionization happens and impact-ionization-induced photon emission is created in the base-collector (BC) junction and photon absorption happens in the base-emitter (BE) junction. This makes the carrier injection from the BE junction to the BC junction with avalanche different from that without avalanche. Similarly, the avalanche-induced light emission in the BE junction will induce photocarriers in the BC junction diode. In this paper, we report observation of the photovoltage in the BC junction resulting from hot-carrier electroluminence in the BE junction on a conventional low-power n-p-n bipolar transistor. We found a photovoltage of 0.36 V and a collector current reversal in the inverse active operation. 相似文献
43.
L. K. Jang G. G. Geesey S. L. Lopez S. L. Eastman P. L. Wichlacz 《Chemical Engineering Communications》1990,94(1):63-77
The sorption equilibrium of dissolved copper by spherical partially-coagulated gels of calcium alginate was investigated in this work. The gels were formed by dispensing a viscous algin (food grade sodium alginate from kelp) solution with a multi-tip dispenser into 0.05 M CaCl2 solution in a loop fluidized bed reactor. The resultant semi-rigid spherical gels were then transferred to another reactor operated batch wise to absorb dissolved copper at low concentrations (10-40 ppm). When the concentration of the inert neutral salt NaNO3, added to the reactor fluid was 0.01 M, the amount of copper absorbed was found to be substantially higher than that at 0.1 MNaN03. The conventional Langmuir's model based on the concentration of copper in solution yielded different values of conditional stability constant at different ionic strengths in the reactor fluid. However, by defining the copper-binding stability constant on the basis of copper activity in the gel phase with the competition from calcium for metal binding sites taken into account, a unique copper-binding stability constant and a unique calcium-binding stability constant were obtained. The numerical procedure for estimating the activity of copper in the gel fluid was modified from Jang et al. Water Research, 1990, in press). 相似文献
44.
Namchu Kim Dean A. McHenry Sei-Joo Jang Thomas R. Shrout 《Journal of the American Ceramic Society》1990,73(4):923-928
The physical, dielectric, and optical properties of hot isostatically pressed lead magnesium niobate polycrystalline ceramics modified with 1/2 mol% La2 O3 , Pb1–3/2 x La x □ x /2 -(Mg1/3 Nb2/3 )O3 , have been investigated. Methods used to characterize the ceramics included determination of the dielectric permittivity, optical transmittance, and refractive index dispersion. The materials exhibited relaxor ferroelectric type behavior with a peak dielectric constant K > 14000 and average T c ∼−35°C. Various sintering, hot isostatic pressing, and annealing conditions were examined to produce highly dense and optically transparent materials. Through the use of hot isostatic pressing, densities more than 99.5% theoretical and transmittance greater than 50% at 633-nm wavelength were obtained. Hot isostatic pressing technique appears to be a good alternative to hot uniaxial pressing without the associated problem of PbO volatility, reactivity with the pressure vessel, and geometrical constraints. 相似文献
45.
Gyeonghye Yim Seounghun Kang Hyungjun Kim Young‐Jin Kim Yeong‐Gyu Gil Young‐Kwan Kim Dal‐Hee Min Hongje Jang 《Advanced functional materials》2020,30(9)
The synthesis of nanostructures using homogeneous precursors in the solution phase is widely used to achieve uniformity and well‐defined morphological control. However, drawbacks such as the lack of diversity due to the limited reaction rate modulation exist. One‐step, core–shell nanorod formation using simultaneous covering synthesis using solid and ionic heterogeneous precursors is proposed in this study. A Te‐Bi2Te3/TeO2 core–shell structure is successfully synthesized by precisely controlling various influencing factors, including concentration, temperature, and pH, and its physicochemical and photochemical properties are thoroughly investigated. The proposed nanostructure overcomes the oxidation susceptibility of Te and can be applied to multipotent cancer theranostics in vitro and in vivo in combination with computed tomography imaging. 相似文献
46.
A reconfigurable microstrip antenna for switchable polarization 总被引:3,自引:0,他引:3
A novel reconfigurable microstrip antenna with switchable polarization sense is proposed. The proposed antenna has a simple structure, consisting of a corner-truncated square radiating patch, four small triangular conductors, and a microstrip line feed. Using independently biased PIN diodes on the patch, it can produce linear polarization, or left- or right-hand circular polarization according to bias voltages. From the measured results, low cross-polarization levels when operated in the linear state and good axial ratios in the circular state are observed. 相似文献
47.
In Hwan Park Yoon Hyun Kim Jae Sang Cha Yeong Min Jang Jin Young Kim 《Wireless Personal Communications》2011,60(3):533-545
In this paper, effects of reader-to-reader interference are investigated for LED identification (LED-ID) system in a multi-reader
environment. The LED-ID readers typically use different channels to avoid collision between readers. However, in-channel collision
usually happens in terms of interrogation range. A reader-to-reader interference scenario is proposed, and nominal interrogation
range of a desired reader is derived from this model. In order to evaluate the LED-ID reader-to-reader interference quantitatively,
an efficient detection scheme is proposed and simulated by employing spreading sequence. The spreading sequence is inserted
between each user’s frame formats. In the receiver, the desired signal is detected by using correlation among inserted spreading
sequences. From simulation results, it is confirmed that the proposed scheme is very effective to enhance reliability of LED-ID
communication systems. 相似文献
48.
Jaeyoung Jang Sooji Nam Kyuhyun Im Jaehyun Hur Seung Nam Cha Jineun Kim Hyung Bin Son Hwansoo Suh Marsha A. Loth John E. Anthony Jong‐Jin Park Chan Eon Park Jong Min Kim Kinam Kim 《Advanced functional materials》2012,22(5):1005-1014
The preparation of uniform large‐area highly crystalline organic semiconductor thin films that show outstanding carrier mobilities remains a challenge in the field of organic electronics, including organic field‐effect transistors. Quantitative control over the drying speed during dip‐coating permits optimization of the organic semiconductor film formation, although the kinetics of crystallization at the air–solution–substrate contact line are still not well understood. Here, we report the facile one‐step growth of self‐aligning, highly crystalline soluble acene crystal arrays that exhibit excellent field‐effect mobilities (up to 1.5 cm V?1 s?1) via an optimized dip‐coating process. We discover that optimized acene crystals grew at a particular substrate lifting‐rate in the presence of low boiling point solvents, such as dichloromethane (b.p. of 40.0 °C) or chloroform (b.p. of 60.4 °C). Variable‐temperature dip‐coating experiments using various solvents and lift rates are performed to elucidate the crystallization behavior. This bottom‐up study of soluble acene crystal growth during dip‐coating provides conditions under which one may obtain uniform organic semiconductor crystal arrays with high crystallinity and mobilities over large substrate areas, regardless of the substrate geometry (wafer substrates or cylinder‐shaped substrates). 相似文献
49.
Hun Soo Jang Seonggwang Yoo Seong Hyeon Kang Jongjun Park Gi‐Gwan Kim Heung Cho Ko 《Advanced functional materials》2020,30(5)
This work demonstrates a means of automatic transformation from planar electronic devices to desirable 3D forms. The method uses a spatially designed thermoplastic framework created via extrusion shear printing of acrylonitrile–butadiene–styrene (ABS) on a stress‐free ABS film, which can be laminated to a membrane‐type electronic device layer. Thermal annealing above the glass transition temperature allows stress relaxation in the printed polymer chains, resulting in an overall shape transformation of the framework. In addition, the significant reduction in the Young's modulus and the ability of the polymer chains to reflow in the rubbery state release the stress concentration in the electronic device layer, which can be positioned outside the neutral mechanical plane. Electrical analyses and mechanical simulations of a membrane‐type Au electrode and indium gallium zinc oxide transistor arrays before and after transformation confirm the versatility of this method for developing 3D electronic devices based on planar forms. 相似文献
50.
Juang Miin-Horng Chang Chia-Wei Shye Der-Chih Hwang Chuan-Chou Wang Jih-Liang Jang Sheng-Liang 《半导体学报》2010,31(6):064003-064003-5
A process simplification scheme for fabricating CMOS poly-Si thin-film transistors (TFTs) has been pro-posed, which employs large-angle-tilt-implantation of dopant through a gate sidewall spacer (LATITS). By this LATITS scheme, a lightly doped drain region under the oxide spacer is formed by low-dose tilt implantation of phosphorus (orboron) dopant through the spacer, and then the n+-source/drain (n+-S/D) (or p+-S/D) region is formed via using the same photo-mask layer during CMOS integration. For both n-TFT and p-TFT devices, as compared to the sample with conventional single n+-S/D (or p+-S/D) structure, the LATITS scheme can cause an obviously smaller leakage current, due to more gradual dopant distribution and thus smaller electric field. In addition, the resultant on-state currents only show slight degradation for the LATITS scheme, As a result, by the LATITS scheme, CMOS poly-Si TFT devices with an on/off current ratio well above 8 orders may be achieved without needing extra photo-mask layers during CMOS integration. 相似文献