1,880 research outputs found
Do Concentration Cells Store Charge in Water? Comment on Can Water Store Charge?
In a recent article, Ovchinnikova and Pollack (O&P)(1) reported that the persistent pH gradients (>100 min after electrolysis) generated upon charging a simple electrolytic cell (Pt electrodes in dilute aqueous NaCl solutions) imply that “water can store charge”, in apparent violation of the principle of electroneutrality in bulk macroscopic fluid phases
Delaunay Surfaces
We derive parametrizations of the Delaunay constant mean curvature surfaces
of revolution that follow directly from parametrizations of the conics that
generate these surfaces via the corresponding roulette. This uniform treatment
exploits the natural geometry of the conic (parabolic, elliptic or hyperbolic)
and leads to simple expressions for the mean and Gaussian curvatures of the
surfaces as well as the construction of new surfaces.Comment: 16 pages, 11 figure
W-boson production with large transverse momentum at the LHC
We study W-boson production with large transverse momentum, Q_T, in pp
collisions at the LHC. We calculate the complete NLO corrections and the
soft-gluon NNLO corrections to the differential cross section. The NLO
corrections are large but they do not reduce the scale dependence relative to
LO, while the NNLO soft-gluon corrections, although small, significantly reduce
the scale dependence and thus provide a more stable result.Comment: 5 pages, 3 figures, presented at the XIV International Workshop on
Deep Inelastic Scattering (DIS 2006), Tsukuba, Japan, April 20-24, 200
Depth of cohomology support loci for quasi-projective varieties via orbifold pencils
The present paper describes a relation between the quotient of the
fundamental group of a smooth quasi-projective variety by its second commutator
and the existence of maps to orbifold curves. It extends previously studied
cases when the target was a smooth curve. In the case when the quasi-projective
variety is a complement to a plane algebraic curve this provides new relations
between the fundamental group, the equation of the curve, and the existence of
polynomial solutions to certain equations generalizing Pell's equation. These
relations are formulated in terms of the depth which is an invariant of the
characters of the fundamental group discussed in detail here.Comment: 22 page
Nonequilibrium Stefan-Boltzmann law
We study thermal radiation outside equilibrium. The situation considered
consists of two bodies emitting photons at two different temperatures. We show
that the system evolves to a stationary state characterized by an energy
current which satisfies a Stefan-Boltzmann-like law expressing it as the
difference of the temperatures to the fourth power of the emitters . The
results obtained show how the classical laws governing the thermal radiation at
equlibrium can be generalized away from equilibrium situations.Comment: 9 pages, 1 figure. To be published in J. Noneq. Ther
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