We solve the coupled mode equations governing the chalcogenide nonlinear fiber Bragg gratings (FBGs) numerically, and obtain the bistability characteristics. The characteristics of the chalcogenide nonlinear FBGs such as: switching threshold intensity, bistability interval and on-off switching ratio are studied. The effects of FBG length and its third order nonlinear refractive index on FBG cha...

Non-axisymmetric simulations verify and extend the results from a previous linear Floquet stability analysis of the wakes of rings. The wakes corresponding to the saturated state of each predicted non-axisymmetric instability mode over the entire aspect ratio range are successfully computed, and isosurface plots are presented elucidating the vortical wake structures. The existence of three non-...

A shortcut procedure as quick, easy-to use method for design and simulation of multicomponent batch distillation is used to predict the operating condition of recovering xylene from solvent in an existing batch distillation column in benzol refinery. The procedure can be used to investigate the effect of the operating parameters on the operation of column for three possible modes of batch d...

Pb(In1/2Nb1/2)O3–Pb(Mg1/3Nb2/3)O3–PbTiO3 (PIN–PMN–PT) piezoelectric single-crystal rectangular beams with the PIN:PMN:PT ratio of 0.33:0.35:0.32 are prepared, and their mode-coupling effect is investigated both theoretically and experimentally for ultrasonic array transducer applications. The PIN–PMN–PT rectangular beams become a tall-narrow beam and a short-wide plate, and so exhibiting an unc...

We present an on-chip optical mode exchange between two multiplexed modes by using tapered directional couplers on silicon-on-insulator platform. The device consisting of mode multiplexing and mode exchange is compact with relatively large fabrication error tolerance. The simulation results show efficient higher order mode excitation and mode exchange. A low excess loss less than 0.5 dB and hig...

We develop a quantitative theory of the ratio R of radiative to non-radiative de-excitation based on the Dexter-Klick-Russell criterion for the occurrence of luminescence. The model invokes three essential elements: a promoting mode, an accepting mode, and a set of lattice modes which ultimately absorb the vibrational energy. The ratio R is determined by the relative population of the relaxed e...

Four noise-assisted empirical mode decomposition (EMD) algorithms, i.e., ensemble EMD (EEMD), complementary (CEEMD), complete with adaptive noise (CEEMDAN), and improved (ICEEMDAN), are noticeable improvements to EMD, aimed at alleviating mixing. However, the sampling frequency ratio (SFR), between maximum signal frequency, may significantly impact their mixing alleviation performance. Aimed th...

The fluid-structure interaction problems of two side-by-side flexible plates with a finite aspect ratio in a three-dimensional (3D) uniform flow are numerically studied. The plates’ motions are entirely passive under the force of surrounding fluid. By changing the aspect ratio and transverse distance, the coupling motions, drag force and energy capture performance are analyzed. The mechanisms u...