background: physical wedges are still widely used as beam modifiers in external beam radiotherapy. however the presence of them in the beam trace may cause beam hardening which may not be considered in many treatment planning systems. the aim of this study is to investigate the beam hardening effect generated by physical wedges via different beam quality indexes as photon spectrum, half value l...

INTRODUCTION : The most informative neutron scattering investigations of the atomic-scale dynamical properties of crystalline solids nearly always require single crystal samples and – to date have mostly been carried out on crystal spectrometers at high-flux, reactor-based, steady-state neutron sources. Because such measurements tend to be made with small samples and are invariably flux-limited...

The melting process during laser powder bed fusion (LPBF) is accompanied by complex physical phenomena, which can be rarely scaled with acceptable effort to utilize the in component design obtain tailored mechanical properties adequate machine productivity. A constitutive law relating melt pool geometry parameters thereby plays an essential role practically fostering productivity and quality LP...

Abstract Metamaterials are a class of non-natural materials with special properties, the microstructure which does not exist in nature. By artificially designing structure such materials, they can acquire electromagnetic properties that conventional nature do have. Electromagnetically induced transparency refers to process quantum interference effect between atomic energy levels microscopic sys...

This article describes the challenges in focusing nanoparticles (<30 nm) into tightly collimated beams, and provide guidelines for designing aerodynamic lens systems for nanoparticles. The major difficulties of focusing nanoparticles arise from their low inertia and high diffusivity. Because of their low inertia, nanoparticles tend to closely follow gas streamlines; their high diffusivities lea...

A 1/20 scale model of a Y-shaped irregular bridge was designed, and shaking-table tests were performed to simulate its failure mechanism performance characteristics when subjected multidirectional strong earthquake. The results showed that the structure could accelerate in horizontal direction vertical excitation. For both unidirectional excitation, acceleration response pier top more significa...

This paper aims to explore the working mechanism of sandwich-like meta-plates by periodically attaching nonlinear mass-beam-spring resonators for low-frequency wave attenuation. The MBS resonator consists a mass, cantilever beam, and spring provide negative stiffness in transverse vibration resonator; this is tunable changing parameters spring. Considering resonator, energy method applied obtai...

A General Retrospective Olaf Zimmermann: How did your book come to be? How did you get together, and how did you nd your contributors and reviewers? Bobby Woolf: Martin Fowler was the matchmaker. When he wrote Patterns of Enterprise Application Architecture,2 Kyle Brown pointed out that his pattern language was not addressing asynchronous messaging. Martin felt that he already had plenty of pat...

We have developed a three-dimensional Gaussian-beam ray-tracing program to aid in the design of infrared, far-infrared, and millimeter wave interferometer and polarimeter diagnostic systems for magnetic confinement fusion relevant plasma physics experiments. An overview of the program is presented along with a description of the ray-tracing algorithm. A model is developed for the case of diffra...