A single-arm rectangular spiral antenna is analyzed using the finite-difference time-domain method. The spiral is printed on a finite-size dielectric substrate backed by a finite-size conducting plane. Both the substrate and conducting planes are square with a side length of less than 0.6 0 ( 0: wavelength in free space). The radiation pattern is dependent on the outermost arm peripheral length...

The fundamental parameters approach to line profile fitting uses physically based models to generate the line profile shapes. Fundamental parameters profile fitting (FPPF) has been used to synthesize and fit data from both parallel beam and divergent beam diffractometers. The refined parameters are determined by the diffractometer configuration. In a divergent beam diffractometer these include ...

Under the influence of axial forces and uniform temperature variations, thermal buckling postbuckling composite beams reinforced functionally graded multilayer graphene platelets (GPLs) resting on nonlinear elastic foundations are examined. The Halpin-Tsai model is used to calculate modulus each layer GPL-reinforced (GPLRC). According virtual work principle, governing equations for beam obtaine...

Polarized Raman spectra were obtained on well oriented Ðlms of a-helical poly(L-alanine) (a-PLA) and its Ndeuterated analogue in order to obtain deÐnitive assignments of the modes. Such assignments were aided E 2 -species by an analysis of factors that can lead to “cross-talkÏ between A, and spectra, viz. reÑection of the incident E 1 E 2 beam and non-perfect lateral and axial chain orientation...

This paper focuses on investigating the structural behavior of members and connections that are part moment frames under combined effect bending thermally induced axial force during a compartment-fire event. The finite-element analysis method was employed to conduct this study using models benchmarked against experimental data from several past studies while utilizing temperature-dependent mate...

Vibrating micro- and nanomechanical mass sensors are capable of quantitatively determining attached mass from only the first three (two) measured cantilever (suspended) resonant frequencies. However, in aqueous solutions that are relevant to most biological systems, the mass determination is challenging because the quality factor (Q-factor) due to fluid damping decreases and, as a result, usual...

We demonstrate experimentally the generation of an optical beam having an axial focusing that is narrower than the Fourier limit. The beam is constructed from a superposition of Bessel beams with different longitudinal wave vectors, realizing a super-oscillatory axial intensity distribution. Such beams can be useful for microscopy and for optical particle manipulation.

This article investigates the collapse characteristics of thin-walled tubes with octagonal cross sections during axial crushing. The tubes’ axial crushing resistance (the relationship between crushing force and axial deformation) is described with a series of mathematical equations, which are derived applying global energy equilibrium theory. The derived axial crushing resistance is then used f...

Abstract T‐stubs and L‐stubs loaded in tension are generally assumed contact with a rigid foundation. The prying force stiffness of these components depend on this hypothesis. For double web angle riveted connections, the rests deformable beam/column web. objective present paper is to take into account effects deformability development area, rivet forces tensile stiffness. An enhanced theory be...