Results 141 to 150 of about 5,629,785 (335)

Water Permeates and Plasticizes Amorphous Carbon Dots: Unraveling the Inner Accessibility of the Nanoparticles by Glass Transition Studies

open access: yesAdvanced Materials, EarlyView.
The water permeability of amorphous carbon dots (CDs) is demonstrated by investigating their plasticization. Novel polyamide‐based and amorphous nanoparticles are synthesized by controlling their inner packing density. Water plasticization is evidenced by the decrease of the CDs glass transition temperature with increasing the hydration degree.
Elisa Sturabotti   +8 more
wiley   +1 more source

Forward acoustic performance of a shock-swallowing high-tip-speed fan (QF-13) [PDF]

open access: yes
Forward noise and overall aerodynamic performance data are presented for a high-tip-speed fan having rotor blade airfoils designed to alter the conventional leading-edge bow shocks to weak, oblique shocks which are swallowed within the interblade ...
Lucas, J. G.   +2 more
core   +1 more source

Avco Lycoming quiet clean general aviation turbofan engine [PDF]

open access: yes, 1980
A fan module was developed using an existing turboshaft engine. The fan was designed using the latest in large engine noise control technology. A mixer was added to reduce the already low exhaust gas velocity.
Wilson, C. A.
core   +1 more source

Radiation‐Resistant Aluminum Alloy for Space Missions in the Extreme Environment of the Solar System

open access: yesAdvanced Materials, EarlyView.
A novel ultrafine‐grained aluminum crossover alloy exhibits unprecedented radiation resistance and mechanical stability under extreme irradiation doses up to 100 dpa. The exceptional resilience arises from thermodynamically stable T‐phase precipitates, enabling lightweight structural materials for next‐generation spacecraft and extraterrestrial ...
Patrick D. Willenshofer   +9 more
wiley   +1 more source

Active Learning‐Guided Accelerated Discovery of Ultra‐Efficient High‐Entropy Thermoelectrics

open access: yesAdvanced Materials, EarlyView.
An active learning framework is introduced for the accelerated discovery of high‐entropy chalcogenides with superior thermoelectric performance. Only 80 targeted syntheses, selected from 16206 possible combinations, led to three high‐performance compositions, demonstrating the remarkable efficiency of data‐driven guidance in experimental materials ...
Hanhwi Jang   +8 more
wiley   +1 more source

Analysis of aerodynamic and aeroacoustic performances of axial flow fans with variable winglet curvature in chordwise direction

open access: yesResults in Engineering
This study introduces a novel concept for axial-flow fans with winglets featuring gradually decreasing curvature along the chordwise direction. The objective is to mitigate the formation of leakage vortices in the gap flow region between the fan blade ...
Seo-Yoon Ryu   +3 more
doaj   +1 more source

Noise and wake structure measurements in a subsonic tip speed fan [PDF]

open access: yes
The results of an experimental program are reported which show the effect of blade angle, tip speed, fan pressure ratio, and thrust on noise of a model fan of 0.457m (18 inches) diameter operating at subsonic tip speeds at pressure ratios between 1.06 ...
Hanson, D. B.   +3 more
core   +1 more source

Moth‐Wing‐Inspired Multifunctional Metamaterials

open access: yesAdvanced Materials, EarlyView.
This study develops a moth‐wing‐inspired heterogeneous metamaterial that achieves synergistic broadband sound absorption, mechanical energy dissipation, and thermal insulation within a lightweight architected framework. Combining bioinspired gradient design, genetic‐algorithm optimization, and additive manufacturing, the bionic heterogeneous acoustic ...
Haoran Pei   +12 more
wiley   +1 more source

A review of aerodynamic noise from propellers, rotors, and lift fans [PDF]

open access: yes
Hand calculation procedures for predicting aerodynamic noise from propellers, rotors, and lift ...
Kurtz, D. W., Marte, J. E.
core   +1 more source

Ultralow‐Frequency Epsilon‐Near‐Zero States in 3D‐Printed High‐Entropy Alloy Metacomposites for Ultra‐Thin Perfect RF Absorption

open access: yesAdvanced Materials, EarlyView.
Rozanov causality limit—a compulsive proportional thickness‐wavelength relationship (nd ∝ λ)—makes it challenging to develop perfect absorption with both thin thickness and low frequency. Herein, a cocktail effect in high‐entropy alloys (HEA) is crucially utilized for lowering plasma frequency to achieve epsilon‐near‐zero states, which finally enables ...
Peitao Xie   +7 more
wiley   +1 more source

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