Results 51 to 60 of about 91,594 (288)

Full and half-wavelength ultrasonic percussive drills [PDF]

open access: yes, 2018
Ultrasonic-percussive drills are a leading technology for small rock drilling applications where power and weight-on-bit are at a premium. The concept uses ultrasonic vibrations to excite an oscillatory motion in a free-mass, which then delivers ...
Harkness, Patrick   +2 more
core   +1 more source

Surface Tension Measurement of Ti‐6Al‐4V by Falling Droplet Method in Oxygen‐Free Atmosphere

open access: yesAdvanced Engineering Materials, EarlyView.
In this article, the temperature‐dependent surface tension of free falling, oscillating Ti‐6Al‐4V droplets is investigated in both argon and monosilane doped, oxygen‐free atmosphere. Droplet temperature and oscillation are captured with one single high‐speed camera, and the surface tension is calculated with Rayleigh's formula.
Johannes May   +9 more
wiley   +1 more source

Backside delamination detection in composites through local defect resonance induced nonlinear source behavior [PDF]

open access: yes, 2020
A
Hedayatrasa, Saeid   +4 more
core   +2 more sources

In Situ Constructed Magnetic Core‐Shell Hydrogen‐Bonded Organic Framework‐on‐Metal–Organic Framework Structure: an Efficient Catalyst for Peroxymonosulfate Activation

open access: yesAdvanced Functional Materials, EarlyView.
In this work, a magnetic core‐shell catalyst (HOF‐on‐Fe3O4/ZIF‐67) is successfully synthesized, consisting of a metal–organic framework (ZIF‐67) with magnetic Fe3O4 as the core and a porous hydrogen‐bonded organic framework (HOF) as the shell. The catalyst efficiently activated peroxymonosulfate, resulting in rapid and effective removal of water ...
Yingying Du   +4 more
wiley   +1 more source

Enhancement of the Al/Mg Dissimilar Friction Stir Welding Joint Strength with the Assistance of Ultrasonic Vibration

open access: yesMetals, 2021
The assistance of ultrasonic vibration during the friction stir welding (FSW) process has been verified as an effective approach for the improvement of joint strength.
Yinghao Bai, Hao Su, Chuansong Wu
doaj   +1 more source

NanoMOF‐Based Multilevel Anti‐Counterfeiting by a Combination of Visible and Invisible Photoluminescence and Conductivity

open access: yesAdvanced Functional Materials, EarlyView.
This study presents novel anti‐counterfeiting tags with multilevel security features that utilize additional disguise features. They combine luminescent nanosized Ln‐MOFs with conductive polymers to multifunctional mixed‐matrix membranes and powder composites. The materials exhibit visible/NIR emission and matrix‐based conductivity even as black bodies.
Moritz Maxeiner   +9 more
wiley   +1 more source

Enhancing engagement behavior in small-diameter deep drilling through ultrasonic vibration-assisted drilling and quantitative evaluation of hole dimensions

open access: yesJournal of Advanced Mechanical Design, Systems, and Manufacturing
This study investigates the effects of ultrasonic vibration-assisted drilling with a 0.3 mm diameter drill on engagement behavior and hole dimensions.
Naofumi TSUJI   +6 more
doaj   +1 more source

MnI‐Functionalized Covalent Organic Framework as Efficient Electrocatalyst for CO2 Reduction in a Catholyte‐Free Zero‐Gap Electrolyzer

open access: yesAdvanced Functional Materials, EarlyView.
This work demonstrates the successful integration of a phenanthroline‐based 2D COF with MnI catalytic sites into a catholyte‐free membrane‐electrode‐assembly cell for CO2 electroreduction. The crystalline COF actively suppresses Mn⁰–Mn⁰ dimerization, achieving a turnover frequency of 617 h⁻¹ at 2.8 V (full‐cell potential), and enabling stable operation.
Laura Spies   +8 more
wiley   +1 more source

An Ultrasonic Vibration Scratch Tester for Studying the Scratch Characteristics of Materials under Ultrasonic Vibration Contact Status

open access: yesActuators
Ultrasonic vibration-assisted machining is a promising technique for improving the removability of materials, especially for difficult-to-machine materials, but the material removal mechanism under ultrasonic vibration status is still far from clear ...
Yaming Huang   +4 more
doaj   +1 more source

A Novel Ultrasonic Trepanning Method for Nomex Honeycomb Core

open access: yesApplied Sciences, 2020
The vertical surface is a common and typical characteristic structure among Nomex honeycomb core components. However, the conventional high-speed milling and ultrasonic cutting struggle to meet the high-quality machining requirements of a vertical ...
Dingyi Sun   +4 more
doaj   +1 more source

Home - About - Disclaimer - Privacy