In a recent article in Nature [1], titled Gain-assisted superluminal light propagation, experimentalists reported observing a laser pulse propagating faster than the speed of light through a gas cell which served as a amplifying medium. They state that the "peak of the pulse appears to leave the cell before entering it". This article generated a great deal of press attention around the world. F...

‎let $i$ be an ideal in a regular local ring $(r,n)$‎, ‎we will find‎ ‎bounds on the first and the last betti numbers of‎ ‎$(a,m)=(r/i,n/i)$‎. ‎if $a$ is an artinian ring of the embedding‎ ‎codimension $h$‎, ‎$i$ has the initial degree $t$ and $mu(m^t)=1$‎, ‎we call $a$ a {it $t-$extended stretched local ring}‎. ‎this class of‎ ‎local rings is a natural generalization of the class of stretched ...

We give a new interpretation of the shifted Littlewood-Richardson coefficients $f_{\lambda\mu}^\nu$ ($\lambda,\mu,\nu$ are strict partitions). The $g_{\lambda\mu}$ which appear in decomposition Schur $Q$-function $Q_\lambda$ into sum functions $Q_\lambda = 2^{l(\lambda)}\sum_{\mu}g_{\lambda\mu}s_\mu$ can be considered as special case (here $\lambda$ is partition length $l(\lambda)$). also anoth...

Background and Objectives: : Vitamin D3 measurement in food and fortified food matrixes is usually interrupted by several variables. This study aimed to elaborate a specific vitamin D3 quantification method for fortified Taftoon bread considering different influential variables in each step of measurement. Materials and Methods: Dough was fortified with (4μg/100g) and the sta...

The stability of delivery of low monitor unit (MU) setting is important especially for step-andshoot intensity-modulated radiotherapy (IMRT), because the nature of the technique is inherent to repeat beam on/off according to the number of the segments. This study evaluates the dose linearity and profile flatness/symmetry under low MU settings for Vero4DRT, a new linear-accelerator based irradia...

A complete and critical survey is presented of all half-life, decay-energy and branching-ratio measurements related to 20 superallowed 0 + → 0 + decays; no measurements are ignored, though some are rejected for cause and others updated. A new calculation of the statistical rate function f is described and experimental f t values determined. The associated theoretical corrections needed to conve...