Results 21 to 30 of about 14,611,742 (406)

Structured beams invariant to coherent diffusion [PDF]

open access: yesOptics Express, 2020
Bessel beams are renowned members of a wide family of non-diffracting (propagation-invariant) fields. We report on experiments showing that non-diffracting fields are also immune to diffusion. We map the phase and magnitude of structured laser fields onto the spatial coherence between two internal states of warm atoms undergoing diffusion.
Slava Smartsev   +4 more
openaire   +4 more sources

Evaluation of an EPID in vivo monitoring system using local and external independent audit measurements

open access: yesJournal of Applied Clinical Medical Physics, Volume 23, Issue 12, December 2022., 2022
Abstract Purpose The aim of this work was to evaluate the SunCHECK PerFRACTION, the software for in vivo monitoring using EPID images. Materials/Methods First, the PerFRACTION ability to detect errors was investigated simulating two situations: (1) variation of LINAC output and (2) variation of the phantom thickness.
Samuel Ramalho Avelino   +3 more
wiley   +1 more source

A nonlinear beam model of photomotile structures [PDF]

open access: yesProceedings of the National Academy of Sciences, 2020
Significance Actuation and propulsion are significant challenges in soft robotics. Supply of power typically requires a cumbersome tether or heavy onboard power source. Further, one typically needs to reset the system. Using theory and numerical simulations, we show, in this work, that this challenge can be overcome by the use of ...
Kevin Korner   +4 more
openaire   +5 more sources

Digital radiography image quality evaluation using various phantoms and software

open access: yesJournal of Applied Clinical Medical Physics, Volume 23, Issue 12, December 2022., 2022
Abstract Purpose To investigate the effect of the exposure parameters on image quality (IQ) metrics of phantom images, obtained automatically using software or from visual evaluation. Methods Three commercial phantoms and a homemade phantom constructed according to the instructions given in the IAEA Human Health Series No.
Ioannis A. Tsalafoutas   +4 more
wiley   +1 more source

Characterizing ultra-low emittance electron beams using structured light fields [PDF]

open access: yesPhys. Rev. Accel. Beams 24 (2021) 012803, 2020
Novel schemes for generating ultra-low emittance electron beams have been developed in the last years and promise compact particle sources with excellent beam quality suitable for future high-energy physics experiments and free-electron lasers. Current methods for the characterization of low emittance electron beams such as pepperpot measurements or ...
arxiv   +1 more source

Structural Damping with Friction Beams [PDF]

open access: yesShock and Vibration, 2007
In the last several years, there has been increasing interest in the use of friction joints for enhancing damping in structures. The joints themselves are responsible for the major part of the energy dissipation in assembled structures. The dissipated work in a joint depends on both the applied normal force and the excitation force.
L. Gaul, Jens Becker, J. Roseira
openaire   +3 more sources

Buckling of Planar Micro-Structured Beams [PDF]

open access: yesApplied Sciences, 2020
In this paper, a Timoshenko beam model is formulated for buckling analysis of periodic micro-structured beams, uniformly compressed. These are planar grid beams, whose micro-structure consists of a square lattice of equal fibers, modeled as Timoshenko micro-beams.
Ferretti M., D'Annibale F.
openaire   +3 more sources

A Novel Damage Indicator Based on the Electromechanical Impedance Principle for Structural Damage Identification

open access: yesSensors, 2018
This paper presents a novel structural damage detection indicator, i.e., fourth-order voltage statistical moment (FVSM) based on the electromechanical impedance (EMI) principle, and then proposes a two-step damage detection method based on the novel ...
Pin Zhou, Dansheng Wang, Hongping Zhu
doaj   +1 more source

Analysis on the Difference of Impact Response between Single Coal-Rock Particle and the Box Structure-Based Tail Beam

open access: yesShock and Vibration, 2021
In the process of coal caving, the basis of identifying coal and rock by the vibration signal is the difference of the tail beam response when coal-rock impacts the tail beam, and the tail beam in the hydraulic support is a complex box structure with ...
Li-rong Wan, Zhe Li, Yang Yang, Ran Li
doaj   +1 more source

SEISMIC MITIGATION EFFICIENCY STUDY OF THE COUPLING BEAM DAMPER IN THE SHEAR WALL STRUCTURE

open access: yesCivil Engineering Journal, 2021
Coupling beam damper can be easily repaired in the post-earthquake, which can dissipate the seismic energy of the structure in the earthquake action. In this paper, the seismic mitigation efficiency of the coupling beam damper in the shear wall structure
Xin Huang
doaj   +1 more source

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