Radiation Aging of Cross-Linked Poly(Methyl Methacrylates)

Radiation aging of poly(methyl methacrylate) and copolymers of methyl methacrylate with trans-1,2-di(methacryloxy)cyclohexane, 3,4-di(methacryloxy)sulfolane, and 9,10-di(methacryloxymethyl)anthracene was studied.     

On sharp bounds for marginal densities of product measures

We develop a new approach for counting integral solutions of the system of equations associated to rational lines on cubic hypersurface. As a consequence, we deduce the density result for rational lines on the cubic hypersurface defined by c1z₁³ + ··· + c_sz_s³ = 0 as soon as s≥21.     

Polarization effects of the τ → <Emphasis Type="Italic">K</Emphasis>–π<Superscript>0</Superscript>ν<Subscript>τ</Subscript> process in the Nambu–Jona-Lasinio model

The polarization effects of the τ → K–π⁰ν_τ process are described in the framework of the Nambu–Jona-Lasinio model. The intermediate vector meson K*(892) is taken into account. The contribution of these effects to the differential decay width is obtained.     

On determinants and the volume of random polytopes in isotropic convex bodies

In this paper we consider random polytopes generated by sampling points in multiple convex bodies. We prove related estimates for random determinants and give applications to several geometric inequalities.     

Photoacoustic and laser-induced evaporation effects in liquids

It is shown experimentally that the photoacoustic pressure response in absorbing condensed matter to laser pulses with high frequency modulation of intensity can be used to monitor displacement of the irradiated surface. Some aspects of the processes under investigation are also discussed, including acoustic diffraction effects, features of acoustic reflection from liquid–air and liquid–solid boundaries, explosive boiling, and interference between thermoacoustic and vaporization pressure signals.     

S-Band Klystron Development

Physics of Particles and Nuclei Letters - An S-band klystron of 50 MW power is being developed at the Budker Institute of Nuclear Physics. At the moment, all the necessary calculations have been...     

Spectral dependences of conical emission in gases: Minimization of scattering for ultra-short pulsed laser ablation

Parameters of conical emission (CE), at focusing of femtosecond and short picosecond pulses in ambient gases, are characterized in a wide range of experimental conditions. Scattered and absorbed energy, the beam profiles and spectra are compared for different duration and wavelengths of laser radiation (harmonics of Ti:Sa and Yb:YAG laser). Shorter wavelengths were found to be most beneficial for elimination of CE. Nearly no scattering of short picosecond pulses was observed at 515 nm in the energy density range up to 300 J/cm². The results are analyzed in terms of the contributing ultra-fast phenomena effecting refraction index of gases (the Kerr effect, different mechanisms of ionization). Advantages of the visible pulses are illustrated in deep drilling experiments.     

A probabilistic take on isoperimetric-type inequalities

We extend a theorem of Groemer on the expected volume of a random polytope in a convex body. The extension involves various ways of generating random convex sets. We also treat the case of absolutely continuous probability measures rather than convex bodies. As an application, we obtain a new proof of a recent result due to Lutwak, Yang and Zhang on the volume of Orlicz-centroid bodies.