Results 61 to 70 of about 8,503,197 (295)

Characterization of contact condition in a flange connection by longitudinal waves

open access: yesMechanical Engineering Journal, 2018
The integrity of flange joints is critical in all pipe systems. To test this integrity, an ultrasonic method characterizing the condition of the flange joint would be a vital tool. In this study, we analyzed the contact conditions on a metal/gasket/metal
Hideo CHO   +3 more
doaj   +1 more source

Thermodynamic Pathways of Nonequilibrium Solidification in Wire‐Arc Additive Manufacturing Fe‐Based Multicomponent Alloy Structures

open access: yesAdvanced Engineering Materials, EarlyView.
Geometry‐driven thermal behavior in wire‐arc additive manufacturing (WAAM) influences microstructural evolution during nonequilibrium solidification of a chemically complex Fe–Cr–Nb–W–Mo–C nanocomposite system. By comparing different deposits configurations, distinct entropy–cooling rate correlations, segregation, and carbide evolution are revealed ...
Blanca Palacios   +5 more
wiley   +1 more source

Estimation de la fréquence instantanée des signaux FM par opérateur d'énergie Psi_B [PDF]

open access: yes, 2011
Psi_B energy operator is an extension of the cross Teager-Kaiser energy operator which is an non-linear energy tracking operator to deal with complex signals and its usefulness for non-stationary signals analysis has been demonstrated. In this letter two
BOUDRAA, Abdel-Ouahab
core  

Adaptive instantaneous frequency estimation of multicomponent FM signals using quadratic time-frequency distributions

open access: yes, 2002
An adaptive approach to the estimation of the instantaneous frequency (IF) of nonstationary mono- and multicomponent FM signals with additive Gaussian noise is presented. The IF estimation is based on the fact that quadratic time-frequency distributions (
Boashash, Boualem   +3 more
core   +1 more source

Mobile unit velocity estimation based on the instantaneous frequency of the received signal [PDF]

open access: yes, 2004
This paper presents a new mobile station velocity estimator based on the first moment of the instantaneous frequency (IF) of the received signal. The effects of shadowing, additive noise, and scattering distribution on the proposed velocity estimator are
Azemi, G.   +5 more
core   +1 more source

Influence of Scan Strategies in Electron Beam Powder Bed Fusion on Solidification, Microstructure, and High‐Temperature Compressive Properties of γ′‐Strengthened Inconel 738LC

open access: yesAdvanced Engineering Materials, EarlyView.
Experiments and thermophysical simulations were conducted to investigate the electron beam powder bed fusion electron beam (PBF‐EB/M) process for the γ′‐strengthened nickel‐based superalloy Inconel 738LC. The results demonstrate the impact of process‐induced microstructural variations on high‐temperature mechanical behavior, providing a basis for ...
Jan Niklas Petenati   +11 more
wiley   +1 more source

Adaptive instantaneous frequency estimation: Techniques and algorithms [PDF]

open access: yes, 2002
This thesis deals with the problem of the instantaneous frequency (IF) estimation of sinusoidal signals. This topic plays significant role in signal processing and communications.\ud \ud Depending on the type of the signal, two major approaches are ...
Hussain, Zahir M
core  

Semantic Modeling in Materials Science and Engineering With Platform MaterialDigital Core Ontology 3.0

open access: yesAdvanced Engineering Materials, EarlyView.
The community‐driven Platform MaterialDigital Core Ontology (PMDco) 3.0 is introduced as a Basic Formal Ontology‐aligned semantic backbone for the processing–structure–properties paradigm in Materials Science and Engineering. Modular engineering, automated releases, and validation workflows are highlighted and key semantic patterns for materials ...
Markus Schilling   +15 more
wiley   +1 more source

An Adaptive Chirp Mode Decomposition-Based Method for Modal Identification of Time-Varying Structures

open access: yesMathematics
Modal parameters are inherent characteristics of civil structures. Due to the effect of environmental factors and ambient loads, the physical and modal characteristics of a structure tend to change over time.
Xiao-Jun Yao   +4 more
doaj   +1 more source

Uniform Amorphization of Crystalline Silicon Surfaces Enabled by Deep Ultraviolet Femtosecond Laser Pulses

open access: yesAdvanced Engineering Materials, EarlyView.
Deep‐UV (258 nm) femtosecond pulses enable uniform amorphous silicon writing on Si(100)/(111) with a six‐fold larger fluence amorphization window than NIR methods. Optimized fluence and overlap yield 20–45 nm uniform and continuous amorphous layers. Microscopy shows sharp interfaces, and real‐time reflectivity reveals nanosecond melt–resolidification ...
Wissal Benali   +5 more
wiley   +1 more source

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