Modeling the Multi-Stage Classification in a Fluidized Bed Jet Mill

The research and modeling the classification effects in a fluidized bed opposed jet mill are presented. Particle distribution is the result of the interaction between two stages of classification in this mill: gravity classification above the bed, and centrifugal classification in a mill classifier. The objective of the study is to develop a model of multi-stage classification and apply in to the process in question. The universal algorithm of constructing the matrix model of arbitrary complex classification circuit is proposed and the example of its application to modeling the classification in the mill is presented. The experimental identification of the model parameters was carried out.     

Melnikov Functions in Quadratic Perturbations of Generalized Lotka–Volterra Systems

Journal of Dynamical and Control Systems - We present a detailed analysis of Melnikov functions which arise in quadratic perturbations of generalized Lotka–Volterra vector fields with the...     

Nonlinear rotation‐free three‐node shell finite element formulation

A new triangular thin‐shell finite element formulation is presented, which employs only translational degrees of freedom. The formulation allows for large deformations, and it is based on the nonlinear Kirchhoff thin‐shell theory. A number of static and dynamic test problems are considered for which analytical or benchmark solutions exist. Comparisons between the predictions of the new model and these solutions show that the new model accurately reproduces complex nonlinear analytical solutions as well as solutions obtained using existing, more complex finite element formulations. Copyright © 2013 John Wiley & Sons, Ltd.     

Vibrating reed study of the flux line dissipation of ceramic and single-crystal (Ba, K)BiO3

Vibrating reed (VR) and dc and ac magnetic susceptibility measurements were performed on a nominal single crystal of composition (Ba_0.64K_0.36)BiO₃ in an applied magnetic fieldH. Field-cooling and field-sweep data revealed multiple peaks in the reed dissipation 1/Q located below the superconducting transition temperatureT _c (29.6 K forH=0). A shoulder or onset (with increasingT) of dissipation appears forT18 K, which may be a signature of a flux lattice melting transition. VR data for dense ceramic samples of composition (Ba_0.625K_0.375)BiO₃ (T _c=28.6K) exhibit a relatively narrow and smooth peak in 1/Q that corresponds well to a broad, intermediate-temperature peak in the crystal data. Resistivity experiments demonstrate that the single ceramic peak occurs well below the temperature at which the electrical resistanceR0, suggesting that the higher-temperature crystalline peaks are positioned close to the upper critical field line and may be strongly dependent upon grain size or surface properties. Both ac and dc susceptibility data show no clear evidence for multiple phases or gross compositional inhomogeneities in the crystalline sample. Our results demonstrate that the VR technique is an extremely sensitive method to probe sample inhomogeneities and their role in flux pinning phenomena.     

Vibrating reed study of the flux line dissipation of ceramic and single-crystal (Ba,K)BiO3

Vibrating reed (VR) and dc and ac magnetic susceptibility measurements were performed on a nominal single crystal of composition (Ba_0.64K_0.36)BiO₃ in an applied magnetic fieldH. Field-cooling and field-sweep data revealed multiple peaks in the reed dissipation 1/Q located below the superconducting transition temperatureT _c (≈29.6 K forH=0). A shoulder or onset (with increasingT) of dissipation appears forT≤18 K, which may be a signature of a flux lattice melting transition. VR data for dense ceramic samples of composition (Ba_0.625K_0.375)BiO₃ (T _c=28.6K) exhibit a relatively narrow and smooth peak in 1/Q that corresponds well to a broad, intermediate-temperature peak in the crystal data. Resistivity experiments demonstrate that the single ceramic peak occurs well below the temperature at which the electrical resistanceR≈0, suggesting that the higher-temperature crystalline peaks are positioned close to the upper critical field line and may be strongly dependent upon grain size or surface properties. Both ac and dc susceptibility data show no clear evidence for multiple phases or gross compositional inhomogeneities in the crystalline sample. Our results demonstrate that the VR technique is an extremely sensitive method to probe sample inhomogeneities and their role in flux pinning phenomena.