Perforation of steel and polycarbonate plates by tumbling projectiles

An experimental investigation to assess the effect of tumbling by hard-steel, blunt-faced cylindrical projectiles on the impact response of thin 4130 steel and polycarbonate target plates was performed. Deformation and failure phenomena were observed and discussed; comparisons of the results with analytical models and numerical stimulation, described in a previous paper, were also performed for the steel targets. The final velocity of the projectile and the crater length in the target were correlated with the striker impact angle (or yaw angle with a zero oblique angle); reasonable agreement was attained among the experimental, analytical and numerical results. It was found that an increase of the impact angle can increase the velocity drop and the crater length markedly. The increase tends to be stabilized after the impact angle exceeds 50° and the consequences in such a case are almost the same as in side-on impact.     

Proof of the Mixing Theorem for Statistical Systems in Classical Physics

In a general measure-theoretic context, it is proved that the action of a stochastic map on a pair of probability distributions can be characterized by the criterion of decreasing mixing distance.     

Fluorescence correlation spectroscopic studies of diffusion within the ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate

Fluorescence correlation spectroscopy (FCS) measurements have been performed in order to determine the translational diffusion coefficients of three differently charged fluorescent probes (cationic: rhodamine 6G, neutral: 4-dicyanomethylene-2-methyl-6-p-dimethylaminostyryl-4-H-pyran, DCM, and anionic: fluorescein) dissolved within the common room temperature ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate, [bmim][PF6]. These experiments demonstrate that FCS is a rapid, sensitive, precise (typical RSD from 4-8%), and low-consumption screening tool for the determination of analyte mobility within microliter ionic liquid samples.     

Scalar-type spectral operators andC(Ω)-operational calculi

It is shown that a continuous linear operatorT in a locally convex spaceX is a scalar-type spectral operator if and only if it admits aC((T))-operational calculus of a certain kind. This is a genuine extension of previous results of this type since we allow for the case when (T){} is an unbounded set in the complex planeC, a phenomenon which occurs often for continuous operatorsT defined in non- normable spacesX.     

Resonance phenomena for a class of partial differential equations of higher order in cylindrical waveguides

We consider a domain Ω in ?ⁿ of the form Ω = ?^l × Ω′ with bounded Ω′ ? ?^n?l. In Ω we study the Dirichlet initial and boundary value problem for the equation ? u + [(? ? ?… ? ?)^m + (? ? ?… ? ?)^m]u = fe^?iωt. We show that resonances can occur if 2m ≥ l. In particular, the amplitude of u may increase like t^α (α rational, 0<α<1) or like in t as t∞∞. Furthermore, we prove that the limiting amplitude principle holds in the remaining cases.