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Influences of the vortex finder diameter and length on the performance of a 50 mm diameter hydrocyclone for particle separation were investigated comprehensively, and the grade efficiencies of particles as well as the cut-size were analyzed detailedly. The results indicated that the separation efficiency could be promoted by employing a vortex finder with a small diameter and appropriate length, and the optimum length highly depends on the vortex finder diameter. It is observed that the optimum length of the vortex finder increases first and then decreases with the increase of its diameter. Additionally, the grade efficiencies demonstrate that large particles (>25 μm) can be almost entirely separated when the vortex finder diameter is lower than 20 mm, and large particles will escape from the vortex finder if the vortex finder diameter is too large (i.e., 25 mm). Besides, the impacts of the vortex finder diameter and its length on the cut-size are negligible when a small diameter vortex finder (less than 20 mm) is employed, while the cut-size increases significantly when a large vortex finder is used. Finally, empirical correlations have been established to quantitatively predict the optimum vortex finder length, separation efficiency, and Euler number. [ABSTRACT FROM AUTHOR]

Background Adenocarcinoma, the most common form of lung cancer, is one of main human malignant tumors. In this paper, we focus on the effect of antitumor activity of cytokine-induced killer ( CIK) cells on human lung adenocarcinoma cell line A549. Methods CIK cells were obtained by inducing peripheral blood mononuclear cells with recombinant human (rh) interferon-gamma, monoclonal anti- CD3 antibody, rh interleukin (IL)-1alpha, and rhIL-2, which were added into the culture. A549 cell viability of CIK cells was determined using MTS assay. Flow cytometry ( FCM) experiments were performed to detect cell cycle changes. The expression of P27 in A549 cells treated by CIK cells was evaluated by Western blot. Result The percentage of CD3+ CD16+ CD56+ T cells in a representative peripheral blood mononucleated cell sample was 33.7 ± 1.3%. CIK cells, in dose and time dependent manners, inhibited the proliferation of A549. FCM demonstrated that A549 cells were accumulated in G2/M and G0/G1 phases when treated with CIK cells. FCM was used to analyze whether A549 cells treated with CIK cells induced apotosis or necrosis at 10:1 or 20:1. Compared to the control group, P27 was prominently upregulated in the CIK treated group. Conclusion We propose that the pharmacological mechanisms of A549 cells inhibited by CIK cells can be estimated to possibly elicit different biological significance, which, in part, can be ascribed to a different mass transport rate in vitro. [ABSTRACT FROM AUTHOR]

In this work the influences of solid viscosity and the way to scale-down traditional drag models on the predicted hydrodynamics of Geldart A particles in a lab-scale gas-solid bubbling fluidized bed are investigated. To evaluate the effects of drag models, the modified Gibilaro et al. drag model (constant correction factor) and the EMMS drag model (non-constant correction factor) are tested. And the influences of solid viscosity are assessed by considering the empirical model proposed by Gidaspow et al. (1997, Turbulence, Viscosity and Numerical Simulation of FCC Particles in CFB. Fluidization and Fluid-particle Systems, AIChE Annual Meeting, Los Angeles, 58–62) and the models based on kinetic theory of granular flow (KTGF) with or without frictional stress. The resulting hydrodynamics by incorporating the different combinations of the drag model and solid viscosity model into two-fluid model (TFM) simulations are compared with the experimental data of Zhu et al. (2008, Detailed Measurements of Flow Structure inside a Dense Gas-Solids Fluidized Bed.” Powder Technological 180:339–349). The simulation results show that the predicted hydrodynamics closely depends on the setting of solid viscosity. When solid viscosity is calculated from the empirical model of Gidaspow et al., both drag models can reasonably predict the radial solid concentration profiles and particle velocity profiles. When the KTGF viscosity model without frictional stress is adopted, the EMMS drag model significantly over-estimates the bed expansion, whereas the modified Gibilaro et al. drag model can still give acceptable radial solid concentration profiles but over-estimate particle upwards and downwards velocity. When KTGF viscosity model with frictional stress is chosen, both drag models predict the occurrence of slugging. At this time, the particle velocity profiles predicted by EMMS drag model are still in well agreement with the experimental data, but the bed expansion is under-estimated. [ABSTRACT FROM AUTHOR]