Results 101 to 110 of about 294,420 (308)

The JPL Phase B interferometer testbed [PDF]

open access: yes
Future NASA missions with large optical systems will require alignment stability at the nanometer level. However, design studies indicate that vibration resulting from on-board disturbances can cause jitter at levels three to four orders of magnitude ...
Eldred, Daniel B., Oneal, Mike
core   +1 more source

Tuning the Electronic Structure and Spin State of Fe─N─C Catalysts Using an Axial Oxygen Ligand and Fe Clusters for High‐Efficiency Rechargeable Zinc–Air Batteries

open access: yesAdvanced Functional Materials, EarlyView.
A FeN4─O/Clu@NC‐0.1Ac catalyst containing atomically‐dispersed FeN4─O sites (medium‐spin Fe2+) and Fe clusters delivered a half‐wave potential of 0.89 V for ORR and an overpotential of 330 mV at 10 mA cm−2 for OER in 0.1 m KOH. When the catalyst was used in a rechargeable Zn–air battery, a power density of 284.5 mW cm−2 was achieved with excellent ...
Yongfang Zhou   +8 more
wiley   +1 more source

Piezoelectric pushers for active vibration control of rotating machinery [PDF]

open access: yes
The active control of rotordynamic vibrations and stability by magnetic bearings and electromagnetic shakers have been discussed extensively in the literature. These devices, though effective, are usually large in volume and add significant weight to the
Kascak, Albert F., Palazzolo, Alan B.
core   +1 more source

Suppression of flutter [PDF]

open access: yes, 1973
An active aerodynamic control system to control flutter over a large range of oscillatory frequencies is described. The system is not affected by mass, stiffness, elastic axis, or center of gravity location of the system, mode of vibration, or Mach ...
Nissim, E.
core   +1 more source

Spectrally Tunable 2D Material‐Based Infrared Photodetectors for Intelligent Optoelectronics

open access: yesAdvanced Functional Materials, EarlyView.
Intelligent optoelectronics through spectral engineering of 2D material‐based infrared photodetectors. Abstract The evolution of intelligent optoelectronic systems is driven by artificial intelligence (AI). However, their practical realization hinges on the ability to dynamically capture and process optical signals across a broad infrared (IR) spectrum.
Junheon Ha   +18 more
wiley   +1 more source

Vibration control of single floor seismically excited structure using active mass damper [PDF]

open access: yes, 2012
The purpose of this paper is to dampen the vibrations using active mass damper (AMD) flexible structure has been tested using Shake Table by linear cart. The active and passive mass properties has been discussed.
Bhatti, A. Q., Varum, H.
core   +1 more source

Raman Microscopy at the Organic–Inorganic Interfaces in Human Calcified Aortic Valves Shows the Co‐Existence of Whitlockite Crystals and Carbonated Hydroxyapatite‐Mineralized Collagen Fibrils

open access: yesAdvanced Functional Materials, EarlyView.
This study advances our understanding of aortic valve stenosis by capturing spatially resolved chemical and structural changes at the nanoscale. The findings highlight the potential of combined Raman and electron microscopy for understanding calcification mechanisms across diverse tissue types.
Robin H. M. Van der Meijden   +11 more
wiley   +1 more source

Endothelial Cells Angiogenesis in Sulfated Glycosaminoglycan (GAG) Hydrogels Enhanced by Bioactive Glass‐Released Ions

open access: yesAdvanced Functional Materials, EarlyView.
A mechanically tunable hydrogel composed of gelatin, chondroitin sulfate and laminin promotes angiogenesis in vitro without the supplement of growth factors. Endothelial cells morphogenesis was further enhanced by medium conditioned with bioactive glass 58S‐released ions (Ca and Si), thus offering a promising strategy to vascularize 3D tissue ...
Marco Piazzoni   +13 more
wiley   +1 more source

Hybrid Vibration Control under Broadband Excitation and Variable Temperature Using Viscoelastic Neutralizer and Adaptive Feedforward Approach

open access: yesShock and Vibration, 2016
Vibratory phenomena have always surrounded human life. The need for more knowledge and domain of such phenomena increases more and more, especially in the modern society where the human-machine integration becomes closer day after day.
João C. O. Marra   +3 more
doaj   +1 more source

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