in an axisymmetric co2-n2-h2o gas dynamic laser, let ? denote the intersection of the vertical plane of symmetry with the upper part of the (supersonic) nozzle. to obtain a maximal small signal gain, some authors have tested several families of curves for ?. to find the most general solution for ?, an application of pontryagin’s principle led to the conjuncture that the optimal ? must consist o...

Let X be an irreducible smooth projective curve defined over complex numbers, S = {p1, p2, . . . , pn} ⊂ X a finite set of closed points and N ≥ 2 a fixed integer. For any pair (r, d) ∈ N × 1 N Z, there exists a parabolic vector bundle Rr,d,∗ on X , with parabolic structure over S and all parabolic weights in 1 N Z, that has the following property: Take any parabolic vector bundle E∗ of rank r ...

Two difference approximations to the solution of a pseudo-parabolic problem are constructed and shown by means of stability analysis to converge in the "discrete" £2 norm. A relation between parabolic and pseudo-parabolic difference schemes is discussed, and the stability of difference approximations to backward time parabolic and pseudo-parabolic problems is also considered.

let $f$ be a locally univalent function on the unit disk $u$. we consider the normalized extensions of $f$ to the euclidean unit ball $b^nsubseteqmathbb{c}^n$ given by$$phi_{n,gamma}(f)(z)=left(f(z_1),(f'(z_1))^gammahat{z}right),$$ where $gammain[0,1/2]$, $z=(z_1,hat{z})in b^n$ and$$psi_{n,beta}(f)(z)=left(f(z_1),(frac{f(z_1)}{z_1})^betahat{z}right),$$in which $betain[0,1]$, $f(z_1)neq 0$ and $...

in the present work the effect of cu-water nanofluid, as heat transfer fluid, on the performance of a parabolic solar collector was studied numerically. the temperature field, thermal efficiency, mean-outlet temperatures have been evaluated and compared for the conventional parabolic collectors and nanofluid based collectors. further, the effect of various parameters such as fluid velocity, vol...

it is well known that the parabolic partial differential equationsin two or more space dimensions with overspecified boundary data,feature in the mathematical modeling of many phenomena. in thisarticle, an inverse problem of determining an unknowntime-dependent source term of a parabolic equation in generaldimensions is considered. employing some transformations, wechange the inverse problem to...

in a previous work, we introduced particular fuzzy numbers anddiscussed some of their properties. in this paper we use the comparison methodintroduced by dorohonceanu and marin[5] to compare between these fuzzynumbers.

‎in this paper a nonlinear backward parabolic problem in one‎ ‎dimensional space is considered‎. ‎using a suitable iterative‎ ‎algorithm‎, ‎the problem is converted to a linear backward parabolic‎ ‎problem‎. ‎for the corresponding problem‎, ‎the backward finite‎ ‎differences method with suitable grid size is applied‎. ‎it is shown‎ ‎that if the coefficients satisfy some special conditions‎, ‎th...

reflection seismic data consist of primary reflections, coherent and incoherent noises. one of the objectives of seismic data processing is to enhance the quality of the real signals by attenuating different kinds of noises. multiples constitute one of the most troublesome forms of coherent noises in exploration seismology. multiple reflections often destructively interfere with the desired pri...

We present optical fields formed by superposing nondiffracting parabolic beams with distinct longitudinal wave-vector components, generating light profiles that display intensity fluxes following parabolic paths in the transverse plane. Their propagation dynamics vary depending on the physical mechanism originating interference, where the possibilities include constructive and destructive inter...