In this paper, the vibration suppression problem of an axially moving power transmission belt is investigated. The equations of motion of the moving belt is first derived by using Hamilton’s principle for systems with changing mass. The total mechanical energy of the belt system is considered as a Lyapunov function candidate. Using the Lyapunov second method, a nonlinear boundary control law th...

This paper presents a numerical parametric study on design parameters of multispan viscoelastic shear deformable beams subjected to a moving mass via generalized moving least squares method (GMLSM). For utilizing Lagrange’s equations, the unknown parameters of the problem are stated in terms of GMLSM shape functions and the generalized Newmarkscheme is applied for solving the discrete equations...

A new type of wide-field fluorescence microscopy is described, which produces 100-nm-scale spatial resolution in all three dimensions, by using structured illumination in a microscope that has two opposing objective lenses. Illumination light is split by a grating and a beam splitter into six mutually coherent beams, three of which enter the specimen through each objective lens. The resulting i...

High-quality, ordered nanopores in semiconductors are attractive for numerous biological, electrical, and optical applications. Here, GaN nanorods with continuous pores running axially through their centers were grown by organometallic vapor phase epitaxy. The porous nanorods nucleate on an underlying (0001)-oriented GaN film through openings in a SiN(x) template that are milled by a focused io...

In this paper, we present a new algorithmic paradigm for cone-beam image reconstruction. The new class of algorithms, referred to as cone-beam reconstruction by moving frames, enables numerical implementation of exact cone-beam inversion using its intrinsic geometry. In particular, our algorithm allows a 3-D discrete approach to the differentiation-backprojection operator on the curved manifold...

In this paper, the investigational results for a robust adaptive vibration control of a translating tensioned beam with a varying traveling speed are presented. The dynamics of the moving beam are modeled as an Euler-Bernoulli beam, in which the tension applied to the beam is given as a nonlinear spatiotemporally varying function. The moving beam span is divided into two parts, i.e., a controll...

Active vibration control is investigated for axially moving strings with a tersioner. The tensioner is used as an actuator. The active control law is proposed from the view of the traveling wave propagation. Transverse response of both the uncontrolled and the controlled systems is derived in the frequency domain. The designed controller is numerically tested for the string under impulse and ha...

We present a theoretical study of various definitions of laser beam width in a given cross section. Quality of the beam is characterized by dimensionless beam propagation products (BPPs) Δx·Δθ(x)/λ, which are different for the 21 definitions presented, but are close to 1. Six particular beams are studied in detail. In the process, we had to review the properties for the Fourier transform of var...