1,036 research outputs found
On the Existence of Positive Solutions of Quasilinear Elliptic Boundary Value Problems
AbstractWe establish the existence of positive solutions to a class of quasilinear anisotropic problems which have either sublinear or superlinear nonlinearity. With a, b nonnegative constants and α, ÎČ positive constants, one example is If bâa<1 (sublinear case), then for each λâ[0,â), (1) has a solution. On the other hand, if bâa>1 (superlinear case), then there exists a λ*>0 such that for 0⩜λ<λ*, (1) has at least one solution, and for λ>λ* no solution exists
Exact Solution for the Critical State in Thin Superconductor Strips with Field Dependent or Anisotropic Pinning
An exact analytical solution is given for the critical state problem in long
thin superconductor strips in a perpendicular magnetic field, when the critical
current density j_c(B) depends on the local induction B according to a simple
three-parameter model. This model describes both isotropic superconductors with
this j_c(B) dependence, but also superconductors with anisotropic pinning
described by a dependence j_c(theta) where theta is the tilt angle of the flux
lines away from the normal to the specimen plane
REMOVED: Optimization of VMD Process as Draw Solution Recovery Unit in FO Process
This article has been removed: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy).This article has been removed at the request of the Executive Publisher.This article has been removed because it was published without the permission of the author(s)
Conductivity sum rule, implication for in-plane dynamics and c-axis response
Recently observed -axis optical sum rule violations indicate non-Fermi
liquid in-plane behavior. For coherent -axis coupling, the observed flat,
nearly frequency independent -axis conductivity implies
a large in-plane scattering rate around and therefore any
pseudogap that might form at low frequency in the normal state will be smeared.
On the other hand incoherent -axis coupling places no restriction on the
value of and gives a more consistent picture of the observed sum rule
violation which, we find in some cases, can be less than half.Comment: 3 figures. To appear in PR
On Non Commutative Calabi-Yau Hypersurfaces
Using the algebraic geometry method of Berenstein et al (hep-th/0005087), we
reconsider the derivation of the non commutative quintic algebra
and derive new representations by choosing different
sets of Calabi-Yau charges . Next we extend these results to
higher complex dimension non commutative Calabi-Yau hypersurface algebras
. We derive and solve the set of constraint eqs
carrying the non commutative structure in terms of Calabi-Yau charges and
discrete torsion. Finally we construct the representations of
preserving manifestly the Calabi-Yau condition and give comments on the non commutative subalgebras.Comment: 16 pages, Latex. One more subsection on fractional branes, one
reference and minor changes are added. To appear in Phy. Let.
Impact of long-range interactions on the disordered vortex lattice
The interaction between the vortex lines in a type-II superconductor is
mediated by currents. In the absence of transverse screening this interaction
is long-ranged, stiffening up the vortex lattice as expressed by the dispersive
elastic moduli. The effect of disorder is strongly reduced, resulting in a
mean-squared displacement correlator =
characterized by a mere logarithmic growth with distance. Finite screening cuts
the interaction on the scale of the London penetration depth \lambda and limits
the above behavior to distances R<\lambda. Using a functional renormalization
group (RG) approach, we derive the flow equation for the disorder correlation
function and calculate the disorder-averaged mean-squared relative displacement
\propto ln^{2\sigma} (R/a_0). The logarithmic growth (2\sigma=1) in
the perturbative regime at small distances [A.I. Larkin and Yu.N. Ovchinnikov,
J. Low Temp. Phys. 34, 409 (1979)] crosses over to a sub-logarithmic growth
with 2\sigma=0.348 at large distances.Comment: 9 pages, no figure
Nano encapsulation of Drug-loaded Lipid by Temperature induced Phase Transition
Pluronic nanoparticles (NPs) were prepared by means of a temperature-induced phase transition in the mixture composed of Pluronic F-68 and liquid Tween 80/soybean oil containing model drugs such as orlistat, caffeine, and ibuprofen sodium salt. Liquid
soybean oil/Tween 80 was used as a solubilizer for model drugs, and Pluronic F-68 was the polymer that stabilizes liquid soybean oil/Tween 80 containing model drugs. Field-emission scanning electron microscopy and particle size analyzer were used
to observe the morphology and size distribution of the prepared NPs. X-ray diffractometer was used to understand relationship between the crystalline state of the model drug and its solubility in the aqueous media. To observe the feasibility of Pluronic NPs as a
drug delivery system, the release pattern of model drugs was observed
NC Calabi-Yau Manifolds in Toric Varieties with NC Torus fibration
Using the algebraic geometry method of Berenstein and Leigh (BL),
hep-th/0009209 and hep-th/0105229), and considering singular toric varieties
with NC irrational torus fibration, we construct NC extensions
of complex d dimension Calabi-Yau (CY) manifolds embedded
in . We give realizations of the NC toric group, derive the constraint eqs for NC Calabi-Yau (NCCY) manifolds
embedded in and work out solutions for
their generators. We study fractional branes at singularities and show
that, due to the complete reducibility property of group
representations, there is an infinite number of non compact fractional branes
at fixed points of the NC toric group.Comment: 12 pages, LaTex, no figur
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