PRECISE MEASUREMENTS OF PARTICLE ENTRAINMENT IN A STANDING-WAVE ACOUSTIC FIELD BETWEEN 20 AND 3500 Hz

An experimental study is presented to investigate entrainment coefficients of aerosol particles in a sonic wave. The experimental results are contrasted with a well-established analytical expressions for the entrainment coefficient derived from the Brandt–Freund–Hiedemann (BFH) equation. The measurements are carried out in a standing-wave field with an extremely homogeneous and well-determined acoustic velocity field. A CCD-camera with a microscope lens attachment is used to visualize the displacement amplitude of 7.9 μm glass beads in the frequency range from 20 Hz to 3.5 kHz. The particle entrainment coefficients obtained with this visualization method are in good agreement with the theoretical predictions of the BFH equation and with earlier experimental data by Gucker and Doyle. While this prior study revealed some apparent experimental limitations, the present data is derived with an accurate and repeatable measurement technique. The large number of measurements in the current study helps to draw a detailed representation of the acoustic entrainment coefficient.     

Tabu search algorithm for network synthesis

Large scale combinatorial problems such as the network expansion problem present an amazingly high number of alternative configurations with practically the same investment, but with substantially different structures (configurations obtained with different sets of circuit/transformer additions). The proposed parallel tabu search algorithm has shown to be effective in exploring this type of optimization landscape. The algorithm is a third generation tabu search procedure with several advanced features. This is the most comprehensive combinatorial optimization technique available for treating difficult problems such as the transmission expansion planning. The method includes features of a variety of other approaches such as heuristic search, simulated annealing and genetic algorithms. In all test cases studied there are new generation, load sites which can be connected to an existing main network: such connections may require more than one line, transformer addition, which makes the problem harder in the sense that more combinations have to be considered     

The sentiment of a virtual rock concert

Virtual Reality - We created a virtual reality version of a 1983 performance by Dire Straits, this being a highly complex scenario consisting of both the virtual band performance and the appearance...