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Particle Separation (particle + separation)
Selected AbstractsCover Picture: Electrophoresis 8'2010ELECTROPHORESIS, Issue 8 2010Article first published online: 20 APR 2010 Issue no. 8 is a regular issue comprising19 manuscripts distributed over four distinct parts. Part I is on proteins and proteomics and has 5 articles; Part II is on nucleic acids with 5 articles on DNA purification, sequencing, genotyping and differential gene expression; Part III has 4 articles on droplet dispensing and particle separation; Part IV is on various methodologies and applications assembling 5 articles on improved sample preparation method for glycan analysis by CE, measurement of intracellular accumulation chemotherapeutic drugs in cancerous cells, metabolic monitoring in microfluidic cell arrays, microchip electrophoresis for continuous monitoring of microdialysis samples, and determination of glyphosate and its metabolites in plant materials by CE. Featured articles include: Delta2D and Proteomweaver: Performance evaluation of two different approaches for two-dimensional electrophoresis analysis. ((10.1002/elps.200900766)) A Multidimensional Electrophoretic System of Separation for the Analysis of Gene Expression (MESSAGE). ((10.1002/elps.200900624)) Particle trapping using dielectrophoretically patterned carbon nanotubes. ((10.1002/elps.200900717)) [source] Acoustic microfluidic chip technology to facilitate automation of phage display selectionFEBS JOURNAL, Issue 22 2008Jonas Persson Modern tools in proteomics require access to large arrays of specific binders for use in multiplex array formats, such as microarrays, to decipher complex biological processes. Combinatorial protein libraries offer a solution to the generation of collections of specific binders, but unit operations in the process to isolate binders from such libraries must be automatable to ensure an efficient procedure. In the present study, we show how a microfluidic concept that utilizes particle separation in an acoustic force field can be used to efficiently separate antigen-bound from unbound members of such libraries in a continuous flow format. Such a technology has the hallmarks for incorporation in a fully automated selection system for the isolation of specific binders. [source] Computational investigation of the mechanisms of particle separation and "fish-hook" phenomenon in hydrocyclonesAICHE JOURNAL, Issue 7 2010B. Wang Abstract The motion of solid particles and the "fish-hook" phenomenon in an industrial classifying hydrocyclone of body diameter 355 mm is studied by a computational fluid dynamics model. In the model, the turbulent flow of gas and liquid is modeled using the Reynolds Stress Model, and the interface between the liquid and air core is modeled using the volume of fluid multiphase model. The outcomes are then applied in the simulation of particle flow described by the stochastic Lagrangian model. The results are analyzed in terms of velocity and force field in the cyclone. It is shown that the pressure gradient force plays an important role in particle separation, and it balances the centrifugal force on particles in the radial direction in hydrocyclones. As particle size decreases, the effect of drag force whose direction varies increases sharply. As a result, particles have an apparent fluctuating velocity. Some particles pass the locus of zero vertical velocity (LZVV) and join the upward flow and have a certain moving orbit. The moving orbit of particles in the upward flow becomes wider as their size decreases. When the size is below a critical value, the moving orbit is even beyond the LZVV. Some fine particles would recircuit between the downward and upward flows, resulting in a relatively high separation efficiency and the "fish-hook" effect. Numerical experiments were also extended to study the effects of cyclone size and liquid viscosity. The results suggest that the mechanisms identified are valid, although they are quantitatively different. © 2009 American Institute of Chemical Engineers AIChE J, 2010 [source] Convergence in the macroscopic anatomy of the reticulum in wild ruminant species of different feeding types and a new resulting hypothesis on reticular functionJOURNAL OF ZOOLOGY, Issue 1 2010M. Clauss Abstract The reticulum is the second part of the ruminant forestomach, located between the rumen and the omasum and characterized by honeycomb-like internal mucosa. With its fluid contents, it plays a decisive role in particle separation. Differences among species have been linked to their feeding style. We investigated whether reticulum size (absolute and in relation to rumen size) and size of the crests that form the mucosal honeycomb pattern differ among over 60 ruminant species of various body sizes and feeding type, controlling for phylogeny. Linear dimensions generally scaled allometrically, that is to body mass0.33. With or without controlling for phylogeny, species that ingest a higher proportion of grass in their natural diet had both significantly larger (higher) rumens and higher reticular mucosa crests, but neither reticulum height nor reticulum width varied with feeding type. The height of the reticular mucosa crests represents a dietary adaptation in ruminants. We suggest that the reticular honeycomb structures do not separate particles by acting as traps (neither for small nor for large particles), but that the structures reduce the lumen of the reticulum during contractions , at varying degrees of completeness in the different feeding types. In browsing species with rumen contents that may be less fluid and more viscous than those of the reticulum, incomplete closure of the lumen may allow the reticulum to retain the fluid necessary for particle separation. In grazing species, whose rumen contents are more stratified with a larger distinct fluid pool, a more complete closure of the reticular lumen due to higher crests may be beneficial as the reticulum can quickly re-fill with fluid rumen contents that contain pre-sorted particles. [source] Effect of Nano-Aluminum and Fumed Silica Particles on Deflagration and Detonation of NitromethanePROPELLANTS, EXPLOSIVES, PYROTECHNICS, Issue 5 2009Justin Abstract The heterogeneous interaction between nitromethane (NM), particles of nanoscale aluminum (38 and 80,nm diameter), and fumed silica is examined in terms of the deflagration and detonation characteristics. Burning rates are quantified as functions of pressure using an optical pressure vessel up to 14.2,MPa, while detonation structure is characterized in terms of failure diameter. Nitromethane is gelled using fumed silica (CAB-O-SIL®), as well as by the nanoaluminum particles themselves. Use of nanoaluminum particles with fumed silica slightly increases burning rates compared to the use of larger diameter Al particles; however distinct increases in burning rates are found when CAB-O-SIL is removed and replaced with more energetic aluminum nanoparticles, whose high surface area allows them to also act as the gellant. Mixtures including fumed silica yield a reduced burning rate pressure exponent compared to neat NM, while mixtures of aluminum particles alone show a significant increase. Failure diameters of mixture detonations are found to vary significantly as a function of 38,nm aluminum particle loading, reducing more than 50% from that of neat nitromethane with 12.5% (by mass) aluminum loading. Failure diameter results indicate a relative minimum with respect to particle separation (% loading) which is not observed in other heterogeneous mixtures. [source] Multiphase CFD Simulation of a Solid Bowl CentrifugeCHEMICAL ENGINEERING & TECHNOLOGY (CET), Issue 5 2009X. Romaní Fernández Abstract This study presents some results from the numerical simulation of the flow in an industrial solid bowl centrifuge used for particle separation in industrial fluid processing. The computational fluid dynamics (CFD) software Fluent was used to simulate this multiphase flow. Simplified two-dimensional and three-dimensional geometries were built and meshed from the real centrifuge geometry. The CFD results show a boundary layer of axially fast moving fluid at the gas-liquid interface. Below this layer there is a thin recirculation. The obtained tangential velocity values are lower than the ones for the rigid-body motion. Also, the trajectories of the solid particles are evaluated. [source] Spreadsheet for cyclone and hydrocyclone design considering nonspherical particle geometryCOMPUTER APPLICATIONS IN ENGINEERING EDUCATION, Issue 2 2007Marcelo K. Lenzi Abstract Cyclones and hydrocyclones are widely used for gas,solid and liquid,solid particle separations, respectively. The key feature is the presence of a centrifugal field. Equilibrium zone concept is one of the most used approaches for equipment design. This work revisits the design equations for nonspherical particles and compares design results considering nonspherical geometry to results considering spherical geometry and correcting the values to the non-spherical particle geometry. A didactic spreadsheet was prepared for analysis and instruction, and depending on the particle shape and on the particle orientation, errors up to 38% may be obtained in the cut diameter and 10% in the global collection efficiency. © 2007 Wiley Periodicals, Inc. Comput Appl Eng Educ. 15: 134,142, 2007; Published online in Wiley InterScience (www.interscience.wiley.com); DOI 10.1002/cae.20102 [source] | |||||||||||||