ultrasound speed
Recently Published Documents


TOTAL DOCUMENTS

59
(FIVE YEARS 10)

H-INDEX

12
(FIVE YEARS 0)

2021 ◽  
Vol 2094 (2) ◽  
pp. 022018
Author(s):  
Stepan A Yurchenko

Abstract The paper presents a theoretical analysis of the experimental data on the ultrasound speed change in iron during heating and elastic deformation. The mathematical models proposed for assessing the change in the ultrasound speed based on the “adiabatic approximation” method do not explain, using one model, the change in the ultrasound speed in iron during heating and elastic deformation. During theoretical analysis, a new model of ultrasound wave transmission has been proposed, in which the wave energy propagates in the volume of the interatomic bond, namely in the loop, which is formed by the “collectivization” of valence electrons located in the outer orbit of atoms. The new model explains why with an increase in the interatomic distance a, the crystal lattice parameter, and an increase in the natural vibration frequency of atoms Vat during heating and elastic deformation, in one case (heating), the speed of the sound wave decreases, but in the other case (elastic deformation), the speed of the wave increases with a general decrease in the temperature of the rod.


BMJ Open ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. e038684
Author(s):  
Amélie Delabaere ◽  
Benoit Chauveau ◽  
Didier Lémery ◽  
Amandine Ollier ◽  
Candy Guiguet-Auclair ◽  
...  

IntroductionDuring pregnancy, maternal obesity increases the risk of fetal abnormalities. Despite advances in ultrasound imaging, the assessment of fetal anatomy is less thorough among these women. Currently, the construction of ultrasound images uses a conventional ultrasound propagation velocity (1540 m/s), which does not correspond to the slower speed of propagation in fat tissue.The main objective of this randomised study is to compare the completeness of fetal ultrasonography according to whether the operator could choose the ultrasound velocity (1420, 1480 or 1540 m/s) or was required to apply the 1540 m/s velocity.Methods and analysisThis randomised trial is an impact study to compare a diagnostic innovation with the reference technique. The trial inclusion criteria require that a pregnant woman with obesity be undergoing a fetal morphology examination by ultrasound from 20+0 to 25+0 gestational weeks.Randomisation will allocate women into two groups. The first will be the ‘modulable speed’ group, in which operators can choose the speed of ultrasound propagation to be considered for the morphological analysis: 1420, 1480 or 1540 m/s. In the second ‘conventional speed’ group, operators will perform the morphological examination with the ultrasound speed fixed at 1540 m/s. The adjudication committee, two independent experts, will validate the completeness of each examination and the quality of the images.Ethics and disseminationThis research protocol does not change the standard management. The only possible impact is an improvement of the ultrasound examination by improving the quality of the image and the completeness of morphological examination. The Agence du Médicament et produits de santé approved this study (2018-A03478-47). The anonymised data will be available on request from the principal investigator. Results will be reported in peer-reviewed journals and at scientific meetings.Trial registration numberClinicalTrials.gov (http://www.clinicaltrials.gov) Registry (NCT04212234).


Medicine ◽  
2021 ◽  
Vol 100 (21) ◽  
pp. e25947
Author(s):  
Lisa Ruby ◽  
Sergio J. Sanabria ◽  
Natalia Saltybaeva ◽  
Thomas Frauenfelder ◽  
Hatem Alkadhi ◽  
...  

2020 ◽  
Vol 20 (21) ◽  
pp. 12903-12913
Author(s):  
Hector Lise de Moura ◽  
Vitor de Oliveira Silva ◽  
Giovanni Alfredo Guarneri ◽  
Marco Tulio Lopes Guerreiro ◽  
Thiago Alberto Rigo Passarin ◽  
...  

2020 ◽  
Vol 150 ◽  
pp. 106226
Author(s):  
Luís C.S. Nobre ◽  
Ana F. Cristino ◽  
Ângela F.S. Santos ◽  
Carlos A. Nieto de Castro ◽  
Isabel M.S. Lampreia

2020 ◽  
pp. 255-269
Author(s):  
L. Castillo ◽  
M. Del Rio ◽  
J. Carranza ◽  
C. Mateos ◽  
J. J. Tejado ◽  
...  

Deer antlers can be used as an index of individual performance both in ecological and productive contexts. Their quality is often measured only by their biometrical features, such as size, asymmetry or weight. Mechanic characteristics cannot normally be measured without destroying the antler and hence losing the commercial value of the trophies. Here, we studied ultrasonic velocities, density, and tensile strength across various sections of cast antlers of Iberian red deer (Cervus elaphus hispanicus). We found that the speed value depended on the section of the antler and the propagation direction. For antler sections, velocities were lowest for mid–beam and highest for brow tine. Results were similar for density and indirect tensile strength, probably related to differences in functionality among antler sections. Density explained most of the variability of ultrasound–speed. The time elapsed from antler shed affected density more than ultrasound speed. The indirect tensile strength showed a non–linear, decelerating relationship with ultrasound speed. We discuss the applications of ultrasound speed as a non–invasive tool to measure density and physical properties of antlers and antler sections, and their potential use as an index of quality.


Sign in / Sign up

Export Citation Format

Share Document