1,474 research outputs found
Three-dimensional numerical study of flow characteristic and membrane fouling evolution in an enzymatic membrane reactor
In order to enhance the understanding of membrane fouling mechanism, the
hydrodynamics of granular flow in a stirred enzymatic membrane reactor was
numerically investigated in the present study. A three-dimensional Euler-Euler
model, coupled with k-e mixture turbulence model and drag function for
interphase momentum exchange, was applied to simulate the two-phase
(fluid-solid) turbulent flow. Numerical simulations of single- or two-phase
turbulent flow under various stirring speed were implemented. The numerical
results coincide very well with some published experimental data. Results for
the distributions of velocity, shear stress and turbulent kinetic energy were
provided. Our results show that the increase of stirring speed could not only
enlarge the circulation loops in the reactor, but it can also increase the
shear stress on the membrane surface and accelerate the mixing process of
granular materials. The time evolution of volumetric function of granular
materials on the membrane surface has qualitatively explained the evolution of
membrane fouling.Comment: 10 panges, 8 figure
Checkerboard charge density wave and pseudogap in high- cuprates
We consider the scenario where a 4-lattice constant, rotationally symmetric
charge density wave (CDW) is present in the underdoped cuprates. We prove a
theorem that puts strong constraint on the possible form factor of such a CDW.
We demonstrate, within mean-field theory, that a particular form factor within
the allowed class describes the angle-resolved photoemission and scan tunneling
spectroscopy well. We conjecture that the ``large pseudogap'' in cuprates is
the consequence of this type of charge density wave.Comment: We add a new section II on the symmetry property of the checkerboard
CD
Recent advances and current issues in single-cell sequencing of tumors
AbstractIntratumoral heterogeneity is a recently recognized but important feature of cancer that underlies the various biocharacteristics of cancer tissues. The advent of next-generation sequencing technologies has facilitated large scale capture of genomic data, while the recent development of single-cell sequencing has allowed for more in-depth studies into the complex molecular mechanisms of intratumoral heterogeneity. In this review, the recent advances and current challenges in single-cell sequencing methodologies are discussed, highlighting the potential power of these data to provide insights into oncological processes, from tumorigenesis through progression to metastasis and therapy resistance
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