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101.
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John Boyle Ica Manas‐Zloczower DonaldL. Feke 《Particle & Particle Systems Characterization》2004,21(3):205-212
The dispersion behavior of agglomerates of several grades of fumed silica in poly(dimethyl siloxane) liquids has been studied as a function of particle morphology and applied flow conditions. The effects of primary particle size and aggregate density and structure on cohesivity were probed through tensile and shear strength tests on particle compacts. These cohesivity tests indicated that the shear strength of particle compacts was two orders of magnitude higher than the tensile strength at the same overall packing density. Experiments carried out in both steady and time‐varying simple‐shear flows indicate that dispersion occurs through tensile failure. In the steady‐shear experiments,enhanced dispersion was obtained at higher levels of applied stress and, at comparable levels of applied stress, dispersion was found to proceed faster at higher shear rates. Experiments conducted in time‐varying flows further corroborated the results obtained in tensile cohesivity tests. Experiments in which the mean and maximum stresses in the time‐varying flows were matched to the stresses produced in steady shear flows highlight the influence of flow dynamics on dispersion behavior. 相似文献
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The self-diffusion of benzene, toluene, and ethylbenzene in polystyrene have been analyzed using the Vrentas/Duda free-volume diffusion model. Diffusion coefficient predictions suggest an exponential concentration dependence of the activation energy required to overcome attractive forces, E. Without the use of any diffusion data approximating E as zero over the entire concentration range yields self-diffusion coefficient predictions which are in good agreement with experimental data. © 1992 John Wiley & Sons, Inc. 相似文献
107.
Previous work carried out in our laboratories has focused on the formation and investigation of a dextran and concanavalin A (con A) based gel, which has the ability to alter its conformational structure in the presence and absence of free and terminal glucoses such that a gel–sol phase transition occurs. Here we report the diffusion and rheological investigations in to the effects of the addition of insulin and varyingconcentrations of magnesium chloride hexahydrate (Mg2Cl26H2O) at 20 and 37 °C. Rheological examination of glucose-sensitive (dextran-con A) gels were conducted using a cone and plate viscometer used in continual rotation and oscillatory modes. The results are interpreted in terms of the structure of the gel network and suggest rheological assessment provides an effective method of assessing the properties of gel systems. The subsequent testing of such formulations in in-vitro diffusion experiments revealed a reduction in the rate of diffusivity in the insulin marker, poly R-478 dye. The performance of this self-regulating drug delivery system has been examined and the addition of insulin and magnesium chloride may alter the way in which the gel operates as a drug delivery device and in the delivery of insulin. This may have implications for other ligands. 相似文献
108.
Jürgen Kurths M. Carmen Romano Marco Thiel Grigory V. Osipov Mikhail V. Ivanchenko István Z. Kiss John L. Hudson 《Nonlinear dynamics》2006,44(1-4):135-149
We present two different approaches to detect and quantify phase synchronization in the case of coupled non-phase coherent
oscillators. The first one is based on the general idea of curvature of an arbitrary curve. The second one is based on recurrences
of the trajectory in phase space. We illustrate both methods in the paradigmatic example of the R?ssler system in the funnel
regime. We show that the second method is applicable even in the case of noisy data. Furthermore, we extend the second approach
to the application of chains of coupled systems, which allows us to detect easily clusters of synchronized oscillators. In
order to illustrate the applicability of this approach, we show the results of the algorithm applied to experimental data
from a population of 64 electrochemical oscillators. 相似文献
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Thomas J. Cloonan Gaylord W. Richards Anthony L. Lentine Frederick B. McCormick John R. Erickson 《Optical and Quantum Electronics》1992,24(4):S415-S442
Free-space optical implementations of switching networks have been proposed to circumvent many of the system-level problems that may be encountered in systems that require many high-density, high-bandwidth connections. The details of a new class of switching network (the EGS network), that is well-suited to free-space implementations, is described. The common control injection problem that plagues most free-space photonic networks, i.e. how can control information from an electronic source be injected into the network for applications that require relatively high network reconfiguration rates, is examined. A new technique for control injection, called embedded control, which permits network operation even with relatively high network reconfiguration rates is also proposed. 相似文献