Now showing items 1-10 of 23
Multidimensional Kolmogorov-Petrovsky test for the boundary regularity and irregularity of solutions to the heat equation
This paper establishes necessary and sufficient condition for the regularity of a characteristic top boundary point of an arbitrary open subset of ( ) for the diffusion (or heat) equation. The result implies asymptotic ...
Multiple positive solutions of singular discrete p-Laplacian problems via variational methods
We obtain multiple positive solutions of singular discrete p-Laplacian problems using variational methods.
X-ray bursts produced by laboratory sparks in air
X-ray observations were made during fourteen 1.5 to 2.0 m high-voltage discharges in air produced by a 1.5 MV Marx circuit. All 14 discharges generated x-rays in the ∼30 to 150 keV range. The x-rays, which arrived in ...
The initiation of lightning by runaway air breakdown
A mechanism for lightning initiation by the sustained runaway breakdown of air is presented. Unlike earlior models that rely upon large cosmic-ray air showers, this mechanism uses the runaway electrons produced by the ...
A positive solution for singular discrete boundary value problems with sign-changing nonlinearities
This paper presents new existence results for the singular discrete boundary value problem - Δ²u(k - 1) = g(k, u(k)) + λh(k,u(k)), k ∈ [1,T], u(0) = 0 = u(T + 1). In particular, our nonlinearity may be singular in its ...
DQ herculis in profile: Whole earth telescope observations and smoothed particle hydrodynamics simulations of an edge-on cataclysmic variable system
The old nova DQ Herculis was the Whole Earth Telescope Northern Hemisphere target for the 1997 July campaign and was observed on four nights with the SARA 0.9 m telescope during 2003 June. We present updated ephemerides ...
Galactic cosmic-ray modulation using a solar minimum MHD heliosphere: A stochastic particle approach
An example of Galactic cosmic-ray modulation in a fully three-dimensional heliosphere is presented here. We use a stochastic particle method to solve for modulation without requiring symmetric boundaries or fields. We ...
Set differential equations with causal operators
We obtain some basic results on existence, uniqueness, and continuous dependence of solutions with respect to initial values for set differential equations with causal operators.
X-ray bursts associated with leader steps in cloud-to-ground lightning
X-ray and electric field measurements were made during five nearby negative natural lightning strikes in north central Florida during the summer of 2004. The observed X-ray emission typically was detected ∼1 ms before the ...
A comparison between Monte Carlo simulations of runaway breakdown and terrestrial gamma-ray flash observations
Monte Carlo simulations of the runaway breakdown of air are used to calculate the spectra of terrestrial gamma-ray flashes (TGFs), which are then compared with RHESSI and CGRO/BATSE observations. It is found that the recent ...