Results 51 to 60 of about 14,466 (239)

Electrical Conductivities of Conductors, Semiconductors, and Their Mixtures at Elevated Temperatures

open access: yesAdvanced Engineering Materials, EarlyView.
This article presents a comprehensive review of temperature‐dependent electrical conductivity data for multiple material classes at elevated temperatures, highlighting a persistent conductivity gap between metals and semiconductors in the range of 102$\left(10\right)^{2}$– 107$\left(10\right)^{7}$ S/m. Metal–ceramic irregular metamaterials are proposed
Valentina Torres Nieto, Marcia A. Cooper
wiley   +1 more source

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

open access: yesAdvanced 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   +2 more
wiley   +1 more source

Al–Cu Composite Casting of Laser‐Deoxidized Copper: Bonding, Interfacial Chemistry, and Thermal Conductivity

open access: yesAdvanced Engineering Materials, EarlyView.
This study investigates laser‐based oxide removal of Cu inserts in oxygen‐free conditions and examines long‐term oxidation kinetics and surface chemistry under different atmospheres via X‐ray photoelectron spectroscopy. Al–Cu compound casting with differently oxidized surfaces is performed, and intermetallic phase formation, morphology, and thermal ...
Timon Steinhoff   +9 more
wiley   +1 more source

Determination of the vector velocity of artificial ionospheric irregularities based on Doppler measurements by the bi-static scatter method of HF radio signals propagating over long radio paths

open access: yesSolar-Terrestrial Physics
During experiments on the modification of the high-latitude ionosphere by high-power HF radio waves of ordinary or extraordinary polarization of the EISCAT/Heating facility (Tromsø, Norway) in 2013, 2016, and 2019, Doppler measurements of diagnostic HF ...
Borisova T. D.   +3 more
doaj   +1 more source

ELF wave generation in the ionosphere using pulse modulated HF heating: initial tests of a technique for increasing ELF wave generation efficiency [PDF]

open access: yesAnnales Geophysicae, 1999
This paper describes the results of a preliminary study to determine the effective heating and cooling time constants of ionospheric currents in a simulated modulated HF heating, `beam painting' configuration.
R. Barr, P. Stubbe, M. T. Rietveld
doaj   +1 more source

Radio frequency (RF) heated supersonic flow laboratory [PDF]

open access: yes26th Joint Propulsion Conference, 1990
A unique supersonic flow apparatus which employs an inductively-coupled, radio frequency (RF) torch to supply high enthalpy source gas to the nozzle inlet is described. The main features of this system are the plasma tube, a cooled nozzle assembly, and a combustion/expansion chamber with a heat exchanger.
Wantuck, P., Watanabe, H.
openaire   +1 more source

Exploring Dipolar Dynamics and Ionic Transport in Metal‐Organic Frameworks: Experimental and Theoretical Insights

open access: yesAdvanced Functional Materials, EarlyView.
In this study, the interplay of dipolar dynamics and ionic charge transport in MOF compounds is investigated. Synthesizing the novel structure CFA‐25 with integrated freely rotating dipolar groups, local and macroscopic effects, including interactions with Cs cations are explored.
Ralph Freund   +6 more
wiley   +1 more source

Effects of Different Treatments on Storage Stability and Flavor Characteristics of Wheat Germ

open access: yesShipin gongye ke-ji
In order to study the effects of different treatments on the storage stability and flavor characteristics of wheat germ, wheat germ after hot air treatment and radio frequency treatment was vacuum packed and stored at a temperature of 40 ℃ and a humidity
Zihan SHAO   +10 more
doaj   +1 more source

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

open access: yesAdvanced 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   +10 more
wiley   +1 more source

Understanding and Optimizing Li Substitution in P2‐Type Sodium Layered Oxides for Sodium‐Ion Batteries

open access: yesAdvanced Functional Materials, EarlyView.
This work explores Li‐substituted P2 layered oxides for Na‐ion batteries by crystallographic and electrochemical studies. The effect of lithium on superstructure orderings, on phase transitions during synthesis and electrochemical cycling and on the interplay of O‐ versus TM‐redox is revealed via various advanced techniques, including semi‐simultaneous 
Mingfeng Xu   +5 more
wiley   +1 more source

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