Results 41 to 50 of about 1,516 (173)

M-Bonacci Zone Plates for Ultrasound Focusing

Sensors, 2019
In this work, we present a thorough analysis on M-bonacci zone plates for ultrasound focusing applications. These planar lenses are capable of providing bifocal focusing profiles with equal intensity in both foci and become very appealing for a wide ...
Sergio Pérez-López, José Miguel Fuster, Pilar Candelas   +2 more
doaj   +1 more source

Mixing‐Driven Defects and Composition Evolution in Multi‐Material Metal Additive Manufacturing

Advanced Science, EarlyView.
Operando synchrotron X‐ray imaging coupled with high‐fidelity multiphysics modeling uncovers how inter‐material mixing reshapes keyhole dynamics and drives distinct pore‐formation pathways in multi‐material laser powder bed fusion (LPBF). Composition‐dependent instabilities trigger defects, whereas rescanning suppresses porosity and homogenizes Cu ...
Zhilang Zhang, Steve Gaudez, Mario Togni, Steven Van Petegem, Markus Bambach, Mamzi Afrasiabi   +5 more
wiley   +1 more source

Revealing the Nanoscale Morphology Changes of Polymer Electrolyte Membrane Fuel Cell Catalyst Layers due to Conditioning

Advanced Science, EarlyView.
We apply ex situ and in situ scanning transmission X‐ray microscopy to reveal the structural degradation of polymer electrolyte membrane fuel cell catalyst layers due to conditioning and thermal heating of the catalyst coated membrane. We observe a redistribution of the ionomer and carbon‐black in the catalyst layer, as well as nanoscale membrane ...
Spencer Lytle, Harsharaj B. Parmar, Jian Wang, Shohei Yamashita, Aimy Bazylak   +4 more
wiley   +1 more source

Terahertz Channel Modeling, Estimation and Localization in RIS‐Assisted Systems

Advanced Electronic Materials, EarlyView.
Reconfigurable intelligent surfaces have become a recent intensive research focus. Based on practical applications, channel strategies for RIS‐assisted terahertz wireless communication systems are categorized into three different types: channel modeling, channel estimation, and channel localization.
Hongjing Wang, Weipeng Wang, Xuan Cong, Shiyu Wang, Gao Li, Sen Gong, Lin Huang, Hongxin Zeng, Yaxin Zhang, Ziqiang Yang   +9 more
wiley   +1 more source

Design of Binary-Sequence Zone Plates in High Wavelength Domains

Sensors, 2018
The design of zone plates is an important topic in many areas of physics, such as optics, X-rays, microwaves or ultrasonics. In this paper, a zone plate design method, which provides high flexibility in the shaping of the focusing profile, is analyzed ...
José Miguel Fuster, Sergio Pérez-López, Pilar Candelas, Constanza Rubio   +3 more
doaj   +1 more source

Autonomous X‐Ray Fluorescence Mapping for Nanoscale Chemical Speciation of Fine Particulate Matter

Advanced Intelligent Discovery, EarlyView.
We present X‐AutoMap, an autonomous X‐ray fluorescence mapping framework that integrates real‐time analysis with rule‐based computer vision to selectively target chemically relevant regions. By avoiding background‐dominated areas, the method reduces acquisition time by fourfold while enabling accurate particle‐level speciation.
Carlos Deleon, Dmitri Gavrilov, Peggy O’Day, Ajith Pattammattel   +3 more
wiley   +1 more source

The ORCA‐TWIN qCMOS Experiment I. Science Case and Commissioning at Calar Alto Observatory

Astronomische Nachrichten, EarlyView.
ABSTRACT We describe a pilot study to explore a new generation of fast and low noise CMOS image sensors for time domain astronomy, using two remote telescopes with a baseline of 1635 km. The experiment involves direct imaging with novel qCMOS image sensor technology that combines fast readout with sub‐electron readout noise.
Martin M. Roth, Paško Roje, Stella Vješnica, Stefan Cikota, Alex J. Brown, Mike Kretlow, Marco Azzaro, Santiago Reinhart, Jesús Aceituno, Harry Dawson, Carsten Denker, Torsten Enßlin, Stephan Geier, Thomas Granzer, Thomas Kupfer, Gianluca Li Causi, Samaya Nissanke, José Luis Ortiz, Fernando Pedichini, Katja Poppenhäger, Axel Schwope   +20 more
wiley   +1 more source

Design and implementation of a terahertz lens-antenna for a photonic integrated circuits based THz systems

Scientific Reports, 2022
A new integrated lens-antenna is designed and implemented for a nanocontact based terahertz (THz) photomixer. The new design replaces the standard conventional bulky silicon lens, which normally no THz photomixer can avoid. The Fresnel Zone Plate is used
Shihab Al-Daffaie, Alaa Jabbar Jumaah, Verónica Laín Rubio, Thomas Kusserow   +3 more
doaj   +1 more source

Pancharatnam–Berry Phase Driven by Electrical Restructuring of Liquid Crystal Polarization Grating Period

Laser &Photonics Reviews, EarlyView.
Electrically controlled liquid‐crystal twist diffraction element based on the Pancharatnam–Berry phase enables switchable structural periodicity and simultaneous generation of orthogonal circularly polarized coherent waves for multifunctional planar photonic devices.
Elena Melnikova, Katsiaryna Pantsialeyeva, Alexei Tolstik, Veranika Stanevich, Daminika Dashkevich, Anatoli Murauski, Alexander Muravsky, Alina Karabchevsky   +7 more
wiley   +1 more source

Ultra Short Pulse Laser Welding of Glass to Metal in the Low Fluence Regime

Laser &Photonics Reviews, EarlyView.
Ultrashortpulse laser welding enables precise joining of glass and metal with minimal thermal damage. We introduce the TwoThresholds Criteria to identify suitable laser parameters by combining the nonlinearabsorption threshold in glass with the metalmodification fluence threshold.
Lukas Günther, Anne Friedrich, Jens Ulrich Thomas, Andreas Koglbauer, Dominique de Ligny   +4 more
wiley   +1 more source