Results 81 to 90 of about 26,015,827 (334)

Study of frequency band in Von Karman excitation of Francis turbine

open access: yesJournal of Fluid Science and Technology
The objective of this study is to reveal the frequency characteristics caused by Von Karman excitation observed at the stationary field of a Francis turbine.
Takero MUKAI   +2 more
doaj   +1 more source

汶川地震的面波震级测定及其多普勒效应

open access: yesDizhen xuebao, 2018
本文介绍了全球主要地震机构对2008年5月12日汶川地震参数的速报和修订情况,分析了美国地质调查局国家地震信息中心测定的面波震级。通过对比198个全球地震台站测定的面波震级和面波周期,得出如下结论:测定面波震级偏大的台站主要分布在震中的东北方向,测定面波震级偏小的台站主要分布在震中的西南和东南方向,面波周期偏小的台站主要分布在震中东北方向。由于此次地震破裂方向是以北东向单侧破裂为主,且地震多普勒效应导致震中东北方向振动加强,因此该方向上的面波震级偏大,地震烈度衰减慢;而震中西南方向的振动减弱 ...
Ruifeng Liu, Liye Zou, Liwen Zhang
doaj   +1 more source

Automated Hand Flexor Tendon–Thickness Measurement in Systemic Sclerosis

open access: yesArthritis Care &Research, EarlyView.
Objective Systemic sclerosis (SSc) can affect flexor tendons, contributing to hand function problems and reduced quality of life. Tendon changes are currently assessed with ultrasonography and measured manually, a time‐consuming process prone to interobserver variability.
Mark Greveling   +4 more
wiley   +1 more source

The fall and rise of the Doppler effect

open access: yesPhysics today, 2020
The phenomenon is so pervasive that we stake our lives on it, but Doppler’s idea faced fierce criticism that took half a century to overcome.
D. Nolte
semanticscholar   +1 more source

Microvascular Damage Is Associated With Carotid Wall Structural Changes in Systemic Sclerosis: A Capillaroscopy and Ultrasound‐Based Observational Study

open access: yesArthritis Care &Research, EarlyView.
Objective Systemic sclerosis (SSc) is characterized by cardiovascular risk excess not fully explained by traditional factors. Whether the severity of microvascular damage correlates with structural subclinical atherosclerosis remains unclear. We investigated the relationship between nailfold videocapillaroscopy (NVC) abnormalities and carotid ...
Eugenio Capparelli   +13 more
wiley   +1 more source

On the Doppler Effect in a Medium

open access: yes, 1963
This research was supported by the U. S. Air Force through the Air Force Office of Scientific Research of the Air Research and Development Command, under Contract No. AF49(638)-1266. Reproduction in whole or in part is permitted for any purpose of the United States Government. The author is grateful to Professor C. H. Papas for his continued guidance
openaire   +2 more sources

Microstructural Evolution and Vacancy Defect Formation in Mn–Mo–Ni RPV Steel Under Low Cycle Fatigue: Insights From EBSD and PALS

open access: yesAdvanced Engineering Materials, EarlyView.
Low‐cycle fatigue damage in Mn–Mo–Ni reactor pressure vessel steel is examined using a combined electron backscatter diffraction and positron annihilation lifetime spectroscopy approach. The study correlates texture evolution, dislocation substructure development, and vacancy‐type defect formation across uniform, necked, and fracture regions, providing
Apu Sarkar   +2 more
wiley   +1 more source

A Novel Approach to Estimate the Transition Temperature via Dynamic Nanoindentation

open access: yesAdvanced Engineering Materials, EarlyView.
A new dynamic nanoindentation‐based method was developed that uses the stiffness ratio as an indicator of the elastic–plastic deformation contributions at different temperatures. The approach successfully identified transition temperatures in ferritic steel and distinguished them from continuously ductile austenitic steel.
Stefan Zeiler   +4 more
wiley   +1 more source

Guidelines for ultrasound examination in ophthalmology. Part III: Color Doppler ultrasonography

open access: yesJournal of Ultrasonography, 2019
The aim of this article was to present the possibilities of use and application of color-coded Doppler ultrasonography in the diagnosis of various diseases of the eyeball and orbit which result from vascular disorders. Color-coded Doppler ultrasonography
Monika Modrzejewska
doaj   +1 more source

Investigation of Resonance Characteristics of More Than 10 000 Metal‐Coated Silicon MEMS Cantilevers Using Machine Learning

open access: yesAdvanced Engineering Materials, EarlyView.
More than 10 000 metal‐coated silicon MEMS cantilevers are fabricated and characterized to build a large‐scale experimental dataset spanning multiple vibrational modes. Machine learning algorithms are benchmarked to predict resonance frequency and quality factor, with ensemble based models achieving accuracy approaching experimental uncertainty.
Sina Zare Pakzad   +8 more
wiley   +1 more source

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