Results 121 to 130 of about 252,524 (293)

A Study on Parametric Amplification in a Piezoelectric MEMS Device

Micromachines, 2018
In various applications, damping from the surrounding fluid severely degrades the performance of micro-electro-mechanical systems (MEMS). In this paper, mechanical amplification through parametric resonance was investigated in a piezoelectrically ...
Miguel Gonzalez, Yoonseok Lee
doaj   +1 more source

Bistable Mechanisms 3D Printing for Mechanically Programmable Vibration Control

Advanced Engineering Materials, EarlyView.
This work introduces a 3D‐printed bistable mechanism integrated into tuned mass dampers (TMDs) for mechanically adaptive passive vibration suppression. Through optimized geometry, the bistable design provides adaptable vibration reduction across a broad range of scenarios, achieving effective vibration mitigation without complex controls or external ...
Ali Zolfagharian, Frédéric Demoly, Mohammad Lakhi, Bernard Rolfe, Mahdi Bodaghi   +4 more
wiley   +1 more source

Parametric instability of a magnetic junction under modulated spin-polarized current

, 2011
The stability is analyzed of the magnetic junction collinear configurations against small fluctuations under amplitude-modulated current with CPP mode. High spin injection is assumed.
Epshtein, E. M., Zilberman, P. E.
core   +1 more source

COSMOLOGICAL MAGNETIC FIELDS BY PARAMETRIC RESONANCE? [PDF]

COSMO-99, 2000
We investigate the possibility that electromagnetic fluctuations are amplified in expanding universe by parametric resonance, during the oscillatory regime of a scalar field to which they are coupled. We consider scalar electrodynamics and we find that electromagnetic fluctuations undergo exponential instabilities.
openaire   +2 more sources

Evaluation of the Potential of Laser Shock Peening Compared with Cold Expansion for Improving Fatigue Resistance of Riveted Lap Joints of Aerospace Grade 7175 Al Alloy

Advanced Engineering Materials, EarlyView.
This study investigates laser shock peening for enhancing fatigue performance of riveted aerospace aluminum joints. A comparative approach with cold expansion combines fatigue testing and synchrotron X‐ray methods. Integrating mechanical testing with residual stress and strain characterization provides insights into how different treatments affect the ...
Ogün Baris Tapar, David Osman Busse, Maximilian Sprengel, Domenico Furfari, Marc‐André Nielsen, Guilherme Abreu Faria, Jérémy Epp   +6 more
wiley   +1 more source

Elinvar Materials: Recent Progress and Challenges

Advanced Engineering Materials, EarlyView.
Elinvar materials, exhibiting temperature‐invariant elastic modulus, are critical for precision instruments and emerging technologies. This article reviews recent progress in the field, with a focus on the anomalous thermoelastic behavior observed in key material systems.
Wenjie Li, Yang Ren
wiley   +1 more source

Multimodal Mechanical Testing of Additively Manufactured Ti6Al4V Lattice Structures: Compression, Bending, and Fatigue

Advanced Engineering Materials, EarlyView.
In this experimental study, the mechanical properties of additively manufactured Ti‐6Al‐4V lattice structures of different geometries are characterized using compression, four point bending and fatigue testing. While TPMS designs show superior fatigue resistance, SplitP and Honeycomb lattice structures combine high stiffness and strength. The resulting
Klaus Burkart, Jonas Schmidt, Anastasiya Toenjes, Johanna Eisenträger   +3 more
wiley   +1 more source

Air‐Pressure–Actuated Vibroacoustic Metamaterial With Tunable Bandgap: Design, Modeling, and Characterization

Advanced Engineering Materials, EarlyView.
This article presents the design, modeling, and characterization of air‐pressure–actuated programmable vibroacoustic metamaterials (PVAMM). The study focuses on leveraging air pressure to dynamically tune resonance frequencies for effective noise attenuation.
William Kaal, Michael M. Becker, Sarah C. L. Fischer   +2 more
wiley   +1 more source

Ideal Molecular Sieving with a Dense MOF for Helium Upgrading with Highly Diffusion Selective Mixed Matrix Membranes

Advanced Functional Materials, EarlyView.
The separation of Helium gas from natural gas is challenging but highly important. MIL‐116(Ga), a “non‐porous” metal–organic framework is used as a molecular sieve to separate He from CH4. Druse‐like MIL‐116(Ga) particles are integrated into polysulfone mixed matrix membranes.
Ayisha Komal, Laura Calderón‐Rodríguez, Oksana Smirnova, Eren Grossmann, Aparna Binu Varghese, Karen Marlenne Garcia Alvarez, Andreas Schneemann, Thomas Hoyer, Ralf Wyrwa, Felix Helmut Schacher, Alexander Knebel   +10 more
wiley   +1 more source

Intermolecular Interactions as Driving Force of Increasing Multiphoton Absorption in a Perylene Diimide‐Based Coordination Polymer

Advanced Functional Materials, EarlyView.
This study uncovers the unexplored role of intermolecular interactions in multiphoton absorption in coordination polymers. By analyzing [Zn2tpda(DMA)2(DMF)0.3], it shows how the electronic coupling of the chromophores and confinement in the MOF enhance two‐and three‐photon absorption.
Simon Nicolas Deger, Anna Mauri, Yang Cui, Sebastian Josef Weishäupl, Ali Deniz Özdemir, Hamad Syed, Aleksandr Ovsianikov, Wolfgang Wenzel, Alexander Pöthig, Jürgen Hauer, Mariana Kozlowska, Roland Augustinus Fischer   +11 more
wiley   +1 more source