In this paper, a DC-DC resonant converter with high voltage gain and small size is studied. To reduce the size and weight of this converter, the operating frequency should be as high as possible. In this research, the frequency changes from 120 to 200 kHz. Due to the high operating frequency, it is necessary to reduce the switching losses using soft switching methods. Resonant converters are su...

here, we propose an add-drop and a channel drop filter based on two-dimensional photonic crystal all circular ring resonators. these structures are made of a square lattice of silicon rods with the refractive index n1=3.464 surrounded by air (with refractive index n2=1). the broadest photonic band gap occurs at the filling ratio of r/a = 0.17. two linear defect w1 waveguides couple to the ring....

this paper focuses on using the recently developed extended finite element model for buckling analysis of edge cracked columns under concentric axial load. the effect of crack depth and its location on the carrying capacity of columns is studied. the effect of different boundary conditions is also investigated. numerical examples are offered to show the efficiency and effectiveness of the propo...

It is demonstrated that velocity selective optical pumping/saturation resonances of reduced absorption in a Rb vapor nanocell with thickness L= λ, 2λ, and 3λ (resonant wavelength λ = 780 nm) allow the complete elimination of crossover (CO) resonances. We observe well pronounced resonances corresponding to the Fg = 3 → Fe = 2, 3, 4 hyperfine transitions of the Rb D2 line with linewidths close to...

We identify two general types of electronic behaviors for transition-metal impurities that introduce excess electrons in oxides. (i) The dopants introduce resonant states inside the host conduction band and produce free electrons; (ii) the dopants introduce a deep gap state that carries a magnetic moment. By combining electronic structure calculations, thermodynamic simulations, and percolation...

in this article, the effect of cells' radius on the behavior of wavelength switching optical filter andthe effect of the radius of the optical filters' key characteristics such as wavelength resonance onan optical filter based on photonic crystals, have been investigated. currently, the most commonapplied mechanism for designing optical filter based on photonic crystals is using twomechanisms s...

In the present work, we experimentally implement, numerically compute with, and theoretically analyze a configuration in the form of a single column woodpile periodic structure. Our main finding is that a Hertzian, locally resonant, woodpile lattice offers a test bed for the formation of genuinely traveling waves composed of a strongly localized solitary wave on top of a small amplitude oscilla...

This paper shows the results of an experimental programme aimed at evaluating the low-strain shear modulus of a stiff clay (Boom clay, Belgium) and its dependency on water content changes (or, alternatively, degree of saturation or suction) and hydraulic history. Resonant column and bender element tests were carried out at different hydraulic states. Drying and wetting paths were followed using...

Optogalvanic effects are changes in the electrical properties of a gas discharge caused by illumination with radiation at a wavelength corresponding to an atomic or molecular transition. The resurgence of interest in optogalvanic effects stems in a large measure from the unique properties of lasers such as: the high powers, the tunability, the narrow bandwidths, and the controllability of pulse...