Results 201 to 210 of about 8,782 (261)

Research progress and current status of dynamic wave propagation characteristics in rock mass: A review

open access: yesDeep Underground Science and Engineering, EarlyView.
This review elucidates the velocity–dispersion–attenuation coupling mechanisms of wave propagation in rock masses, compares six representative models, and reveals how pressure, temperature, mineral composition, and anisotropy jointly control dynamic responses in complex geological media.
Jiajun Shu   +8 more
wiley   +1 more source

Low‐Temperature in Situ Upgrading of Ultra‐Deep Heavy Oil Using Ni–Ce/MOF–OTf Superacid Catalysts to Enhance Energy Utilization and Sustainability

open access: yesEcoEnergy, EarlyView.
A triflate‐functionalized Ni–Ce/MOF–OTf superacid enables low‐temperature (∼140°C) in situ upgrading of ultra‐deep heavy oil. It reduces viscosity by 92.11% in 12 h, maintains activity over cycles, and delivers 90.25% recovery with a lower carbon footprint by selective bond cleavage. ABSTRACT Ultra‐deep heavy oil is an important unconventional resource,
Li Wang   +5 more
wiley   +1 more source

Novel PTFE/PI Nanofibrous Composite Membranes Enabling High‐Flux Desalination and Durable Anti‐Scaling in Membrane Distillation

open access: yesENERGY &ENVIRONMENTAL MATERIALS, EarlyView.
Schematic illustration comparing the MD performance of pure PTFE NFMs and PTFE/PI NFMs. Polytetrafluoroethylene (PTFE) membranes are widely recognized for their low surface energy and strong resistance to salt accumulation in membrane distillation (MD) processes.
Yuan Liu   +7 more
wiley   +1 more source

Sensitivity of 3D Base‐Isolated Buildings to Individual Isolator Variability

open access: yesEarthquake Engineering &Structural Dynamics, EarlyView.
ABSTRACT Variability in elastomeric isolators arises from differences in rubber formulation and curing, leading to noticeable changes in stiffness and damping among nominally identical bearings. While most previous studies have examined global isolator variability associated with environmental or aging effects, individual isolator variability has ...
Norouz Jahan, Niel C. Van Engelen
wiley   +1 more source

Antibacterial Hydrogel Dressing With Ca2+‐Dependent Hyaluronidase Responsiveness for Accelerating Wound Healing via On‐Demand Release of AIE Photosensitizers

open access: yesExploration, EarlyView.
This study innovates a Ca2+‐responsive hydrogel dressing that releases AIE photosensitizers on‐demand. Low Ca2+ enhances bacterial hyaluronidase (HAase) activity, degrading hyaluronic acid dressing to trigger antibacterial ROS release, while high Ca2+ inhibits HAase, preventing overdosing.
Rongwei Cui   +12 more
wiley   +1 more source

A fractional model of viscoelastic relaxation

Materials Science & Engineering A: Structural Materials: Properties, Microstructure and Processing, 2004
Abstract The fractional model of viscoelastic relaxation was applied for the analysis of the high temperature internal friction background in two materials: a γ-TiAl-based alloy and a tetragonal polycrystalline zirconia ceramic (ZrO2–2.8 mol% Y2O3). In both cases, the fractional model offers a consistent description of the experimental data showing ...
G Haneczok
exaly   +3 more sources

Prevention of Stress Relaxation in Viscoelastic Structures

open access: yesJournal of Structural Engineering, 1992
This paper presents a new problem in linear viscoelastic structural analysis. Homogeneous structures with rigid restraints, where stress relaxation is prevented at a time after loading, are studied. This restriction produces time-dependent increments in the initial displacements.
TARANTINO, Angelo Marcello
openaire   +2 more sources

The Creep and Relaxation of Viscoelastic Polymer

open access: yesAdvanced Materials Research, 2011
Polymers have more complicated properties since they display both elastic and viscous type responses at different strain rates. As the application of polymers increase, a thorough understanding of the mechanical behavior of these materials becomes vital in order to perform innovative and economical designs of various components.
Ga Ping Wang, Yang Bai, Li Chen
openaire   +2 more sources

Viscoelastic Relaxation in Glassy Polymers

open access: yesMRS Proceedings, 1986
AbstractThe nonequilibrium mechanism controlling the viscoelastic response in the glassy state is analyzed in accordance with our multiple hole energy model. The change in the nonequilibrium glassy state defines the Struik physical aging exponent and determines the motion of the relaxation time spectrum, the transition of the global shift factor and ...
T. S. Chow
openaire   +2 more sources

Stress Relaxation Studies of the Viscoelastic Properties of Polymers

open access: yesJournal of Applied Physics, 1956
Extensive studies of the viscoelastic properties of polymers undertaken in the author's laboratory by means of the method of stress relaxation are here reviewed. The discussion is divided into four parts: chemical stress relaxation, stress relaxation in amorphous polymers, stress relaxation in crystalline polymers, and stress relaxation in certain ...
Arthur V. Tobolsky
openaire   +2 more sources

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