Results 81 to 90 of about 153,319 (185)

Damage and fractal evolution trends of sandstones under constant-amplitude and tiered cyclic loading and unloading based on acoustic emission

open access: yesInternational Journal of Distributed Sensor Networks, 2019
It is of significance to study the damage and destruction of rock under cyclic loading in geotechnical engineering. We determined the trends in damage evolution of sandstone under constant-amplitude and tiered cyclic loading and unloading under uniaxial ...
Dongxu Liang   +4 more
doaj   +1 more source

Influence of blade aerodynamic model on prediction of helicopter rotor aeroacoustic signatures [PDF]

open access: yes, 2011
Brown’s vorticity transport model has been used to investigate how the local blade aerodynamic model influences the quality of the prediction of the high-frequency airloads associated with blade–vortex interactions, and thus the accuracy with which the ...
Boyd D. D.   +14 more
core   +1 more source

Highly Sensitive Electrochemical Biosensor Based on Hairy Particles with Controllable High Enzyme Loading and Activity

open access: yesAdvanced Functional Materials, EarlyView.
For the first time, a highly sensitive electrochemical biosensor based on SiO2‐based hairy particles with a grafted PDMAEMA polymer brush containing a quantifiable and large amount of immobilized Laccase is reported. The fabricated biosensor exhibits a sensitivity of 0.14 A·m⁻¹, a limit of detection (LOD) of 0.1 µm, and a detection range of 0.3–750 µm,
Pavel Milkin   +7 more
wiley   +1 more source

Vibration Fatigue Damage Accumulation of Ti–6Al–4V under Constant and Sequenced Variable Loading Conditions

open access: yesMetals, 2018
This study aims to investigate the effect of loading factors on damage accumulation under variable amplitude vibration (VAV). Vibration fatigue experiments are conducted under both constant amplitude vibration (CAV) and VAV loading cases.
Jiewei Lin   +3 more
doaj   +1 more source

Design of power-transmitting shifts [PDF]

open access: yes
Power transmission shafting which is a vital element of all rotating machinery is discussed. Design methods, based on strength considerations for sizing shafts and axles to withstand both steady and fluctuating loads are summarized.
Loewenthal, S. H.
core   +1 more source

CO2 Reduction on Copper‐Nitrogen‐Doped Carbon Catalysts Tuned by Pulsed Potential Electrolysis: Effect of Pulse Potential

open access: yesAdvanced Functional Materials, EarlyView.
This study demonstrates that pulsed potential electrolysis significantly improves CO2 reduction performance on copper‐nitrogen doped carbon electrodes. The formation of cationic copper sites and metallic clusters as a function of applied intermittent potential leads to notable selectivity changes compared to potentiostatic reduction.
Dorottya Hursán   +13 more
wiley   +1 more source

The Strain energy density to estimate lifetime of notched components subjected to variable amplitude fatigue loading

open access: yesFracture and Structural Integrity, 2018
In the present paper, the approach based on the strain energy density (SED) averaged over a structural volume is reformulated to estimate the lifetime of notched components subjected to variable amplitude (VA) uniaxial fatigue loading.
Luca Susmel, Filippo Berto, Zheng Hu
doaj  

Three-dimensional elastic-plastic finite-element analysis of fatigue crack propagation [PDF]

open access: yes
Fatigue cracks are a major problem in designing structures subjected to cyclic loading. Cracks frequently occur in structures such as aircraft and spacecraft.
Chermahini, R. G., Goglia, G. L.
core   +1 more source

Positive‐Tone Nanolithography of Antimony Trisulfide with Femtosecond Laser Wet‐Etching

open access: yesAdvanced Functional Materials, EarlyView.
A butyldithiocarbamic acid (BDCA) etchant is used to fabricate various micro‐ and nanoscale structures on amorphous antimony trisulfide (a‐Sb2S3) thin film via femtosecond laser etching. Numerical analysis and experimental results elucidate the patterning mechanism on gold (reflective) and quartz (transmissive) substrates.
Abhrodeep Dey   +12 more
wiley   +1 more source

Fast‐Responding O2 Gas Sensor Based on Luminescent Europium Metal‐Organic Frameworks (MOF‐76)

open access: yesAdvanced Functional Materials, EarlyView.
Luminescent MOF‐76 materials based on Eu(III) and mixed Eu(III)/Y(III) show rapid and reversible changes in emission intensity in response to O2 with very short response times. The effect is based on triplet quenching of the linker ligands that act as photosensitizers. Average emission lifetimes of a few milliseconds turn out to be mostly unaffected by
Zhenyu Zhao   +5 more
wiley   +1 more source

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