1,432 research outputs found
Laser-based three-dimensional manufacturing technologies for rechargeable batteries.
Laser three-dimensional (3D) manufacturing technologies have gained substantial attention to fabricate 3D structured electrochemical rechargeable batteries. Laser 3D manufacturing techniques offer excellent 3D microstructure controllability, good design flexibility, process simplicity, and high energy and cost efficiencies, which are beneficial for rechargeable battery cell manufacturing. In this review, notable progress in development of the rechargeable battery cells via laser 3D manufacturing techniques is introduced and discussed. The basic concepts and remarkable achievements of four representative laser 3D manufacturing techniques such as selective laser sintering (or melting) techniques, direct laser writing for graphene-based electrodes, laser-induced forward transfer technique and laser ablation subtractive manufacturing are highlighted. Finally, major challenges and prospects of the laser 3D manufacturing technologies for battery cell manufacturing will be provided
Derivation of continuum stochastic equations for discrete growth models
We present a formalism to derive the stochastic differential equations (SDEs)
for several solid-on-solid growth models. Our formalism begins with a mapping
of the microscopic dynamics of growth models onto the particle systems with
reactions and diffusion. We then write the master equations for these
corresponding particle systems and find the SDEs for the particle densities.
Finally, by connecting the particle densities with the growth heights, we
derive the SDEs for the height variables. Applying this formalism to discrete
growth models, we find the Edwards-Wilkinson equation for the symmetric
body-centered solid-on-solid (BCSOS) model, the Kardar-Parisi-Zhang equation
for the asymmetric BCSOS model and the generalized restricted solid-on-solid
(RSOS) model, and the Villain--Lai--Das Sarma equation for the conserved RSOS
model. In addition to the consistent forms of equations for growth models, we
also obtain the coefficients associated with the SDEs.Comment: 5 pages, no figur
Disorder-Induced Depinning Transition
The competition in the pinning of a directed polymer by a columnar pin and a
background of random point impurities is investigated systematically using the
renormalization group method. With the aid of the mapping to the noisy-Burgers'
equation and the use of the mode-coupling method, the directed polymer is shown
to be marginally localized to an arbitrary weak columnar pin in 1+1 dimensions.
This weak localization effect is attributed to the existence of large scale,
nearly degenerate optimal paths of the randomly pinned directed polymer. The
critical behavior of the depinning transition above 1+1 dimensions is obtained
via an -expansion.Comment: 47 pages in revtex; postscript files of 6 figures include
Tracer Dispersion in a Self-Organized Critical System
We have studied experimentally transport properties in a slowly driven
granular system which recently was shown to display self-organized criticality
[Frette {\em et al., Nature} {\bf 379}, 49 (1996)]. Tracer particles were added
to a pile and their transit times measured. The distribution of transit times
is a constant with a crossover to a decaying power law. The average transport
velocity decreases with system size. This is due to an increase in the active
zone depth with system size. The relaxation processes generate coherently
moving regions of grains mixed with convection. This picture is supported by
considering transport in a cellular automaton modeling the experiment.Comment: 4 pages, RevTex, 1 Encapsulated PostScript and 4 PostScript available
upon request, Submitted to Phys. Rev. Let
Anomalous Fluctuations of Directed Polymers in Random Media
A systematic analysis of large scale fluctuations in the low temperature
pinned phase of a directed polymer in a random potential is described. These
fluctuations come from rare regions with nearly degenerate ``ground states''.
The probability distribution of their sizes is found to have a power law tail.
The rare regions in the tail dominate much of the physics. The analysis
presented here takes advantage of the mapping to the noisy-Burgers' equation.
It complements a phenomenological description of glassy phases based on a
scaling picture of droplet excitations and a recent variational approach with
``broken replica symmetry''. It is argued that the power law distribution of
large thermally active excitations is a consequence of the continuous
statistical ``tilt'' symmetry of the directed polymer, the breaking of which
gives rise to the large active excitations in a manner analogous to the
appearance of Goldstone modes in pure systems with a broken continuous
symmetry.Comment: 59 pages including 8 figures ( REVTEX 3.0 )E-mail:
[email protected]
On Growth, Disorder, and Field Theory
This article reviews recent developments in statistical field theory far from
equilibrium. It focuses on the Kardar-Parisi-Zhang equation of stochastic
surface growth and its mathematical relatives, namely the stochastic Burgers
equation in fluid mechanics and directed polymers in a medium with quenched
disorder. At strong stochastic driving -- or at strong disorder, respectively
-- these systems develop nonperturbative scale-invariance. Presumably exact
values of the scaling exponents follow from a self-consistent asymptotic
theory. This theory is based on the concept of an operator product expansion
formed by the local scaling fields. The key difference to standard Lagrangian
field theory is the appearance of a dangerous irrelevant coupling constant
generating dynamical anomalies in the continuum limit.Comment: review article, 50 pages (latex), 10 figures (eps), minor
modification of original versio
Static and Dynamic Properties of Inhomogeneous Elastic Media on Disordered Substrate
The pinning of an inhomogeneous elastic medium by a disordered substrate is
studied analytically and numerically. The static and dynamic properties of a
-dimensional system are shown to be equivalent to those of the well known
problem of a -dimensional random manifold embedded in -dimensions.
The analogy is found to be very robust, applicable to a wide range of elastic
media, including those which are amorphous or nearly-periodic, with local or
nonlocal elasticity. Also demonstrated explicitly is the equivalence between
the dynamic depinning transition obtained at a constant driving force, and the
self-organized, near-critical behavior obtained by a (small) constant velocity
drive.Comment: 20 pages, RevTeX. Related (p)reprints also available at
http://matisse.ucsd.edu/~hwa/pub.htm
PECTINASE-MODIFIED RED GINSENG (GS-E3D) INHIBIT NF-ΚB TRANSLOCATION AND NITRIC OXIDE PRODUCTION IN LIPOPOLYSACCHARIDE-STIMULATED RAW 264.7 CELLS
Objective: Red ginseng has been used as traditional medicines and functional foods in the world, because of its health benefits. The aim of this study was to elucidate the anti-inflammatory effect and mechanism of pectinase-modified red ginseng (GS-E3D) with a cellular model of lipopolysaccharide (LPS)-stimulated RAW264.7 cells.Methods: To study the anti-inflammatory effect of GS-E3D, the key inflammation mediators such as nitric oxide (NO),prostaglandin E2 (PGE2), inducible nitric oxide synthase (iNOS), Cyclooxygenase-2 (COX-2), tumor necrosis factor (TNF-α), and interleukin (IL)-6 production as well as on nuclear factor kappa B (NF-κB) and mitogen-activated protein kinases (MAPKs) activation, were measured by using the enzyme linked immunosorbent assay (ELISA)and Western blotting.Results: GS-E3D potently inhibited TNF-α and IL-6 and also diminished NO over-production, which was accompanied by the down-regulation of iNOS expression. GS-E3D effectively suppressed LPS-induced NF-κB activation through inhibiting the hyper-phosphorylation and degradation of IκB-α and phosphorylation of p38, ERK1/2 and JNK in MAPK signaling pathway.Conclusion: GS-E3D has a potential to be as an anti-inflammatory agent for functional food or cosmetic materials targeting on the NF-κB p65 and MAPKs signaling pathways.Â
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