The effect of flotation cell shape on deinking behaviour

Studies were undertaken to investigate the deinking behaviour of different shaped deinking cells of the same volume. For comparative purposes, most oprational variables were kept constant, and the same injector was used throughout the study. The position of the injector, however, was varied in some cases to go along with the particular cell shape being studied. Three types of cell shapes were studied, (1) cylindrical with tangential air injection, (2) rectanular with vertical injection, and (3) rectangular with horizontal injection. Eucalyptus/toner slurries and news/mag wastepaper slurries were deinked. Flow patterns in the cells and the corresponding deinking efficiencies were measured. It was found that strong and excessive re-circulatory flows within the cells could under certain conditions be a major factor in reducing brightness lift. Vertical injection into a rectangular cell gave stable flow patterns, non-wavy froth removal and sustained brightness lift for a wide range of feed and airflow rates. Horizontal injection into a similar rectangular shaped cell exhibited quite different characteristics. High brightness lift was possible for certain conditions and not for others. Wavy froth and excessive recirculation flow patterns varied with feed and airflow. The cylindrical cell with tangential injection gave stable circulatory flow and stable froth removal at low flow rates but was unable to deink at high flows

Understanding State Government Appropriations For the Arts: 1976-1999

Using panel data analysis, we examine the relative importance of citizen and government characteristics on a highly discretionary and volatile budget item: state appropriations to arts agencies. Despite the unimportance of arts spending to most citizens, changes in arts spending appear to reflect citizen desires. Spending rises with per capita income, state revenues, and citizen political and social liberalism, but characteristics of state legislatures do not significantly affect spending.Department of Economics and W.T. Beebe Institute of Personnel and Employment Relations Working Paper 07-0

Apparatus ad method for quiescent containerless processing of high temperature metals and alloys in low gravity

The electron bombardment furnace consists of two confinement grid sections which may be moved and separated from each other. Inside the bombardment furnace, a tungsten element is enclosed. The material specimen is located within the tungsten element and grounded by means of grounded support wires connected to the respective sections of the furnace. The material specimen is supported on the ground wires and heated by electron bombardment until melt occurs. The furnace sections are separated in opposite directions causing the ground wires to pull from the surfaces of the specimen, leaving the specimen freely suspended in the process chamber without the action of external forces. The specimen remains in its melt condition in the processing chamber where it can be undercooled without external forces acting on the specimen, which would cause dynamic nucleation

Towards human control of robot swarms

In this paper we investigate principles of swarm control that enable a human operator to exert influence on and control large swarms of robots. We present two principles, coined selection and beacon control, that differ with respect to their temporal and spatial persistence. The former requires active selection of groups of robots while the latter exerts a passive influence on nearby robots. Both principles are implemented in a testbed in which operators exert influence on a robot swarm by switching between a set of behaviors ranging from trivial behaviors up to distributed autonomous algorithms. Performance is tested in a series of complex foraging tasks in environments with different obstacles ranging from open to cluttered and structured. The robotic swarm has only local communication and sensing capabilities with the number of robots ranging from 50 to 200. Experiments with human operators utilizing either selection or beacon control are compared with each other and to a simple autonomous swarm with regard to performance, adaptation to complex environments, and scalability to larger swarms. Our results show superior performance of autonomous swarms in open environments, of selection control in complex environments, and indicate a potential for scaling beacon control to larger swarms

Heavy-light meson spectrum with and without NRQCD

Results for the spectrum of S and P-wave charmed mesons are obtained in the quenched approximation from a tadpole-improved anisotropic gauge field action and a D234 quark action. This is compared to the spectrum obtained from an NRQCD charm quark and a D234 light antiquark. NRQCD results for bottom mesons are also discussed.Comment: 4 pages, 5 figures. Lattice 2000 (Heavy Quark Physics

Equivariant Universal Coefficient and Kunneth Spectral Sequences

We construct hyper-homology spectral sequences of Z-graded and ROG-graded Mackey functors for Ext and Tor over G-equivariant S-algebras (A-infty ring spectra) for finite groups G. These specialize to universal coefficient and Kunneth spectral sequences