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1.
Single-phase voltage source power converters (VSCs) under consideration are AC-DC current-controlled boost-type power converters with bidirectional power-handling capability. Equivalence between two series-connected two-level power converters and a single three-level power converter is considered here. Further considered is the series operation of three-level power converters. Simulation results and experimental verification for both are provided. Economical configurations of three-level power converters leading to multilevel waveforms are presented thereafter 相似文献
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3.
R Viswanathan S N Yedave S T Bendre S M Kanetkar S M Chaudhari S B Ogale 《Bulletin of Materials Science》1991,14(2):435-441
Ion beam and thermally-induced interface reactions between highT
c superconducting thin film of Y1Ba2Cu3O7−x
and metal overlayer of Ag are studied with a view to control the interfacial property of contact resistance. The interface
reaction is induced by 100 keV Ar+ ion beam with different ion dose values ranging from 5 × 1013 to 3×1014 ions/cm2. The YBaCuO film-metal interface is characterized by using the small angle XRD to study the structural properties of the
interfacial phases. The electrical property of the interface, specifically contact resistance, has been investigated for different
dose values and thermal treatments. Three-probe vs four-probe configuration has been adopted to measure the contact resistance. 相似文献
4.
Three-phase switch mode rectifier with hysteresis current control 总被引:10,自引:0,他引:10
A three-phase configuration of a switch mode rectifier (SMR) that makes use of continuous conduction waveform of the input supply current is suggested. Continuous conduction is achieved by the hysteresis current control (HCC) technique. This three-phase SMR operates at close to unity power factor and has reduced current stresses on the switching devices because of the continuous nature of input current. The conduction period considered for the rectifier diodes is 180°. Digitally simulated performance results are provided. Selected experimental results demonstrating the SMR operation are also presented 相似文献
5.
S C Patil G Swaminathan Manoj Kumar P V Sastry S B Ogale S M Kanetkar A Pramanik 《Bulletin of Materials Science》1991,14(5):1249-1255
Non-contact processing technique involving the use of CW and pulsed CO2 laser irradiation has been used for reducing the core loss of cold-rolled grain-oriented silicon steel. Laser scribing perpendicular
to the rolling direction resulted in a refinement of domain wall spacing which subsequently reduced the loss of silicon steel.
It was found that laser irradiation was more effective in a specimen with higher magnetic induction (Hi-B) and the loss was
reduced by more than 10% under optimum conditions of the laser irradiation and the scribing speed. Since laser processing
is a non-contact technique, it can be easily applied to the production line of the silicon steel. 相似文献
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The wetting characteristics and surface tension of some ni-based alloys on yttria,hafnia, alumina,and zirconia substrates 总被引:1,自引:0,他引:1
C. S. Kanetkar A. S. Kacar D. M. Stefanescu 《Metallurgical and Materials Transactions A》1988,19(7):1833-1839
Sessile drop experiments were carried out in order to measure surface tensions and to investigate wetting characteristics
of some Ni-based alloys on various ceramic substrates. The liquid-vapor surface tension (γLV) was found to be 1.764 N/m for pure Ni, 1.45 ± 0.11 N/m for Ni-20 pct Cr, 1.29 ± 0.06 N/m for Ni-20 pct Cr-1 pct Al, and
1.31 ± 0.09 N/m for Ni-20 pct Cr-4 pct Al. The commercial alloys UD520, UD718, UD720, and WASPALOY* showed non-wetting behavior
on zirconia but wetting tendency on alumina substrates. Ni-20 pct Cr-1 pct Al showed non-wetting behavior on alumina, hafnia,
and yttria substrates whereas Ni-20 pct Cr and Ni-20 pct Cr-4 pct Al were observed to be non-wetting on hafnia but wetting
on yttria and alumina substrates. All the systems that exhibited wetting behavior were found to be non-wetting in the beginning;
however, wet-ting improved with time. The wetting characteristics were apparently related to impurification of droplets during
measurements, which is reflected in the solidification structure, rather than to the presence of oxides on the surface. 相似文献
8.
V.K. Jain G.K. Lal Y. Kanetkar 《The International Journal of Advanced Manufacturing Technology》2005,26(5-6):527-536
Electrochemical drilling (ECD) is a complex phenomenon involving two phase fluid dynamics, unsteady state heat transfer, mass transfer, electrochemistry etc. between moving boundaries. Anode (work) shape prediction models, therefore, are complicated and incomplete. These models are incomplete because they ignore the analysis of the stray current attack zone and stagnation zone.A modified anode shape prediction model has been proposed. It predicts the work (anode) profile in all the five zones, i.e, stagnation, front, transition, side, and stray current attack. Comparison of computed and experimental anode profiles reveals a satisfactory agreement between the two. 相似文献
9.
Amit R. JagtapVijay S. Satam Rajkumar N. RajuleVinod R. Kanetkar 《Dyes and Pigments》2011,91(1):20-25
A series of novel coumarin based chalcones were synthesized by the classical crossed aldol condensation reaction of 8-acetyl-1,4-diethyl-1,2,3,4-tetrahydro-7H-pyrano[2,3-g]quinoxalin-7-one and various substituted benzaldehydes. These novel ketocoumarin derivatives having a 1,4-diethyl-1,2,3,4-tetrahydroquinoxaline framework exhibited brilliant fluorescence. The novel chalcones absorbed in the range of 458-523 nm in various solvents. The wavelength of maximum absorption of these chalcones was found to be significantly longer than their simple acyl derivative known in the literature. The dyes displayed longer wavelength of absorption in the high polarity solvents compared to non-polar solvents. Thermogravimetric analysis of the chalcones revealed that the chalcones possess good thermal stability. 相似文献
10.
Savakis A.E. Stoughton J.W. Kanetkar S.V. 《IEEE transactions on instrumentation and measurement》1989,38(4):892-897
A spline function approximation approach for measuring the Doppler spectral peak frequency in a laser Doppler velocimeter system is presented. The processor is designed for signal bursts with mean Doppler shift frequencies up to 100 MHz, input turbulence up to 20%, and photon counts as low as 300. The frequency-domain processor uses a bank of digital bandpass filters for the capture of the energy spectrum of each signal burst. The average values of the filter output energies, as a function of normalized frequency, are modeled as deterministic spline functions which are linearly weighted to evaluate the spectral peak location associated with the Doppler shift. The weighting coefficients are chosen to minimize the mean square error. Performance evaluation by simulation yields average errors in estimating mean Doppler frequencies within 0.5% for poor signal-to-noise conditions associated with a low photon count of 300 photons/burst 相似文献