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Articles 1 - 5 of 5
Full-Text Articles in Physical Sciences and Mathematics
Frequency Dynamics During High Ccgt And Wind Penetrations, Lasantha Meegahapola, Damian Flynn
Frequency Dynamics During High Ccgt And Wind Penetrations, Lasantha Meegahapola, Damian Flynn
Dr Lasantha G Meegahapola
Frequency stability is the paramount concern for secure and reliable operation of a power system. High wind penetration levels are reported in power systems with high thermal generation, and hence its likely to result high wind and combined-cycle gas turbine (CCGT) penetrations during system operation since CCGTs are the most preferable choice for the thermal generation. The doubly-fed induction generators (DFIGs) do not provide any inertial response while the CCGTs have unique frequency response during the system frequency disturbances. Therefore, CCGT turbine response characteristics and the zero inertial response may influence on frequency dynamics of a power network. The main …
Impact Of Counterbalance Mass On Torsional Vibrations Of Crankshaft, Asllan Hajderi, Drakuli Lumi
Impact Of Counterbalance Mass On Torsional Vibrations Of Crankshaft, Asllan Hajderi, Drakuli Lumi
UBT International Conference
In the present study is shown how to change the main indicators of vibrations of crankshaft, in case of changing its masses. In the study it was taken the crankshaft of diesel engine with 4 cylinders in line with 5 main journals. To study the torsional vibration of the crankshaft system, the first it is carried the construction of equivalent reduced scheme with five discs connected to four flexible shafts. Results show that the reduced inertia moments of disks for the case with counterbalances grow to 24%. Free frequency and vibration forms, is calculated by using Holxer-Tole method. Results show …
Characterization Of Iso -Cf2 I2 In Frequency And Ultrafast Time Domains, Alexander N. Tarnovsky, Patrick Z. El-Khoury, Lisa George, Aimable Kalume, Scott A. Reid, Bruce S. Ault
Characterization Of Iso -Cf2 I2 In Frequency And Ultrafast Time Domains, Alexander N. Tarnovsky, Patrick Z. El-Khoury, Lisa George, Aimable Kalume, Scott A. Reid, Bruce S. Ault
Alexander Tarnovsky
The photolysis of diiododifluoromethane (CF2 I2) in condensed phases was studied by a combination of matrix isolation and ultrafast time-resolved spectroscopy, in concert with ab initio calculations. Photolysis at wavelengths of 355 or 266 nm of CF2 I2:Ar samples (1:5000) held at ∼8 K yielded iso -CF2 I2 (F2 C-I-I), a metastable isomer of CF2 I2, characterized here for the first time. The infrared (IR) spectra of this isomer were recorded in matrix experiments, and the derived positions of the C-F stretching modes are in very good agreement with the predictions of high level ab initio calculations, which show that …
Dynamical Downscaling Projections Of Twenty-First-Century Atlantic Hurricane Activity: Cmip3 And Cmip5 Model-Based Scenarios, Thomas R. Knutson, Joseph J. Sirutis, Gabriel A. Vecchi, Stephen Garner, Ming Zhao, Hyeong-Seog Kim, Morris Bender, Robert E. Tuleya, Isaac M. Held, Gabriele Villarini
Dynamical Downscaling Projections Of Twenty-First-Century Atlantic Hurricane Activity: Cmip3 And Cmip5 Model-Based Scenarios, Thomas R. Knutson, Joseph J. Sirutis, Gabriel A. Vecchi, Stephen Garner, Ming Zhao, Hyeong-Seog Kim, Morris Bender, Robert E. Tuleya, Isaac M. Held, Gabriele Villarini
CCPO Publications
Twenty-first-century projections of Atlantic climate change are downscaled to explore the robustness of potential changes in hurricane activity. Multimodel ensembles using the phase 3 of the Coupled Model Intercomparison Project (CMIP3)/Special Report on Emissions Scenarios A1B (SRES A1B; late-twenty-first century) and phase 5 of the Coupled Model Intercomparison Project (CMIP5)/representative concentration pathway 4.5 (RCP4.5; early- and late-twenty-first century) scenarios are examined. Ten individual CMIP3 models are downscaled to assess the spread of results among the CMIP3 (but not the CMIP5) models. Downscaling simulations are compared for 18-km grid regional and 50-km grid global models. Storm cases from the regional model …
Compressed Sensing-Based Frequency Selection For Classification Of Ground Penetrating Radar Signals, Wenbin Shao, Abdesselam Bouzerdoum, Son Lam Phung
Compressed Sensing-Based Frequency Selection For Classification Of Ground Penetrating Radar Signals, Wenbin Shao, Abdesselam Bouzerdoum, Son Lam Phung
Professor Salim Bouzerdoum
In this paper we present an automatic classification system for ground penetrating radar (GPR) signals. The system extracts the magnitude spectra at resonant frequencies and classifies them using support vector machines. To locate the resonant frequencies, we propose an approach based on compressed sensing and orthogonal matching pursuit. The performance of the system is evaluated by classifying GPR traces from different ballast fouling conditions. The experimental results show that the proposed approach, compared to the approach of using frequencies at local maxima, represents the GPR signal more efficiently using a small number of coefficients, and obtains higher classification accuracy. 2012 …