The harmony search algorithm is applied to the optimum designs of functionally graded (FG)-carbon nanotubes (CNTs)-reinforced pipes conveying fluid which are subjected to a moving load. The structure is modeled by the Reddy cylindrical shell theory, and the motion equations are derived by Hamilton's principle. The dynamic displacement of the system is derived based on the differential quadratur...

We examine the radiation emitted by high energy positrons channeled into silicon crystal samples. The are modeled as semiclassical vector currents coupled to an Unruh-DeWitt detector incorporate any local change in of positron. In subsequent accelerated QED analysis, we discover a Larmor formula and power spectrum that both thermalized acceleration. Thus, these systems explicitly exhibit therma...

The acceleration of energetic charged particles at relativistic and nonrelativistic shock waves plays an important role in powering esztablished and potential cosmic TeV-gamma-ray sources as supernova remnants, jets of active galactic nuclei and gamma-ray bursts. We therefore review some recent results on non-relativistic shock acceleretion and describe the current standing of the theory for re...

Context: Radio-loud AGNs are thought to possess various sites of particle acceleration, which gives rise the observed non-thermal spectra. Stochastic turbulent acceleration (STA) and diffusive shock (DSA) commonly cited as potential sources high-energy particles in weakly magnetized environments. Together, these processes radiative losses determine emission characteristics extra-galactic radio ...

Recent experimental progress in laser acceleration of charged particles (electrons) and its associated processes has shown that intense electromagnetic pulses can promptly accelerate charged particles to high energies and that their energy spectrum is quite hard. On the other hand some of the high energy astrophysical phenomena such as extremely high energy cosmic rays and energetic components ...

Technical advances in the past 30 years in digital signal processing, analog to digital converters, computers, and software have resulted in significant gains in the field of experimental modal analysis. Advances in transducer technology (force and acceleration transducers) have also contributed to these gains. The present work first describes the development of the early electromechanical tran...

We extend the covariant, parametrized post-Friedmann (PPF) treatment of cosmic acceleration from modified gravity to an arbitrary admixture of matter, radiation, relativistic components and spatial curvature. This generalization facilitates the adaptation of Einstein-Boltzmann codes for solving CMB and matter perturbations in the linear regime. We use such a code to study the effect of metric e...

We have examined cutoffs and pile-ups due to various processes in the spectra of particles produced by shock acceleration, and found that, even in the absence of energy losses, the shape of the spectrum of accelerated particles at energies well below the nominal maximum energy depends strongly on the energy dependence of the diffusion coefficient. This has implications in many areas, for exampl...

%'e present a study of the high-order harmonic-generation (HG) spectra of atomic hydrogen at 248 nm based on the Fourier transform of the expectation values of the induced dipole moment and acceleration. The calculations were performed by extending a fast-Fourier-transformation split-operator technique (in spherical coordinates) to the solution of the time-dependent wave functions in intense la...

For a self-adjoint linear operator with discrete spectrum or a Hermitian matrix the “extreme” eigenvalues define the boundaries of clusters in the spectrum of real eigenvalues. The outer extreme ones are the largest and the smallest eigenvalues. If there are extended intervals in the spectrum in which no eigenvalues are present, the eigenvalues bounding these gaps are the inner extreme eigenval...