http://hdl.handle.net/2440/11 2013-06-20T09:22:20Z http://hdl.handle.net/2440/78374 Title: A combined CFD modeling with population balance equation to predict pressure drop in venturi scrubbers Author: Sharifi, Azam; Mohebbi, Ali Abstract: A venturi scrubber is one of the most important devices for air pollution control. Although there are different models for predicting the pressure drop in venturi scrubbers, most of them have some defects and cannot predict the pressure drop correctly. In this study, for the first time, an Eulerian–Eulerian computational fluid dynamics (CFD) model is combined with a population balance equation to predict the pressure drop in venturi scrubbers. This simulation takes into account a multiple size group model for droplet dispersion and droplet size distribution, which is based on a population balance equation. Flow field has been calculated by solving the time averaged continuity and Navier–Stokes equations along with the standard k–ε turbulence model. The equations included drag, turbulent dispersion, and buoyancy forces. The calculated pressure drop with and without considering the population balance equation was compared with the experimental data to evaluate the accuracy of the CFD modeling. The size distribution of droplets in the venturi scrubber was studied at different points for different liquid to gas ratios and throat gas velocities. The results show that the maximum break-up of droplets happens at the liquid injection point. Finally, the effects of nozzle diameter and nozzle arrangement on pressure drop in venturi scrubbers were investigated. 2012-12-31T13:30:00Z http://hdl.handle.net/2440/78363 Title: Noise statistics in a fast digital radio receiver: the Bedlam backend for the Parkes radio telescope Author: Bray, Justin D.; Ekers, Ronald David; Roberts, Paul Abstract: The digital record of the voltage in a radio telescope receiver, after frequency conversion and sampling at a finite rate, is not a perfect representation of the original analog signal. To detect and characterise a transient event with a duration comparable to the inverse bandwidth it is necessary to compensate for these effects, altering the statistical properties of the signal and making it difficult to determine the significance of a potential detection. We present an analysis of these modified statistics and demonstrate them with experimental results from Bedlam, a new digital backend for the Parkes radio telescope. 2012-12-31T13:30:00Z http://hdl.handle.net/2440/78355 Title: Low-lying odd-parity states of the nucleon in lattice QCD Author: Mahbub, Md. Selim; Kamleh, Waseem Rolf; Leinweber, Derek Bruce; Moran, Peter John; Williams, Anthony Gordon Abstract: The odd-parity nucleon spectrum is examined in the light quark-mass regime in 2+1 flavor lattice QCD. Configurations generated by the PACS-CS Collaboration and made available through the International Lattice Data Grid are used, with the lightest pion mass at 156 MeV. A novel method for tracking the individual energy eigenstates as the quark mass changes is introduced. The success of this approach reveals the flow of the states towards the physical masses. Using the correlation-matrix method, the two lowest-energy states revealed are found to be in accord with the physical spectrum of nature 2012-12-31T13:30:00Z http://hdl.handle.net/2440/78323 Title: A comparative study of the structural, optical, and electrochemical properties of squarate-based coordination frameworks Author: Usov, Pavel M.; Keene, Tony Derek; Alessandro, Deanna Abstract: Systematic studies of the thermal expansion, optical, and redox properties of a series of six squarate-based frameworks, [MII(C4O4)(H2O)2] (MII = MnII, FeII, CoII, NiII, ZnII, CdII) have revealed that five members of the series exhibit cubic structures in which the squarate ligands are configured in an ‘eclipsed’ phase, while the CdII analogue exhibits a trigonal structure with a ‘staggered’ orientation of the ligands. The ‘eclipsed’ structures are characterised by a positive coefficient of thermal expansion, while the CdII analogue exhibits zero thermal expansion. Ultraviolet-visible-near infrared (UV-Vis-NIR) spectra and electrochemical measurements indicate that electron delocalisation across the dianionic squarate bridge is absent. 2012-12-31T13:30:00Z