scholarly journals Mechanical Waves

2021 ◽  
Author(s):  
Ivo Čáp ◽  
Klára Čápová ◽  
Milan Smetana ◽  
Štefan Borik
Keyword(s):  
Mechanical Waves

scholarly journals Thermal-stress analysis of a damaged solid sphere using hyperbolic two-temperature generalized thermoelasticity theory

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hamdy M. Youssef ◽  
Alaa A. El-Bary ◽  
Eman A. N. Al-Lehaibi
Keyword(s):  
Mechanical Damage ◽  
Generalized Thermoelasticity ◽  
Solid Sphere ◽  
Thermoelasticity Theory ◽  
Mechanical Waves ◽  
Temperature Parameter ◽  
Thermoelastic Solid ◽  
The One ◽  
Parameter Values ◽  
Two Temperature

AbstractThis work aims to study the influence of the rotation on a thermoelastic solid sphere in the context of the hyperbolic two-temperature generalized thermoelasticity theory based on the mechanical damage consideration. Therefore, a mathematical model of thermoelastic, homogenous, and isotropic solid sphere with a rotation based on the mechanical damage definition has been constructed. The governing equations have been written in the context of hyperbolic two-temperature generalized thermoelasticity theory. The bounding surface of the sphere is thermally shocked and without volumetric deformation. The singularities of the studied functions at the center of the sphere have been deleted using L’Hopital’s rule. The numerical results have been represented graphically with various mechanical damage values, two-temperature parameters, and rotation parameter values. The two-temperature parameter has significant effects on all the studied functions. Damage and rotation have a major impact on deformation, displacement, stress, and stress–strain energy, while their effects on conductive and dynamical temperature rise are minimal. The thermal and mechanical waves propagate with finite speeds on the thermoelastic body in the hyperbolic two-temperature theory and the one-temperature theory (Lord-Shulman model).

Generation of ROS mediated by mechanical waves (ultrasound) and its possible applications

Methods ◽  
2016 ◽  
Vol 109 ◽  
pp. 141-148 ◽  
Author(s):  
Walter Duco ◽  
Viviana Grosso ◽  
Daniel Zaccari ◽  
Arnaldo T. Soltermann
Keyword(s):  
Mechanical Waves

scholarly journals Development of an analytical model to predict oil reservoirs performance using mechanical waves propagation

2021 ◽  
Author(s):  
Hesham A. Abu Zaid ◽  
◽  
Sherif A. Akl ◽  
Mahmoud Abu El Ela ◽  
Ahmed El-Banbi ◽  
...  
Keyword(s):  
Oil Recovery ◽  
Field Measurements ◽  
Field Trials ◽  
Oil Field ◽  
Reservoir Properties ◽  
Actual Performance ◽  
Reservoir Performance ◽  
Mechanical Waves ◽  
Incremental Oil Recovery ◽  
Wave Induced

The mechanical waves have been used as an unconventional enhanced oil recovery technique. It has been tested in many laboratory experiments as well as several field trials. This paper presents a robust forecasting model that can be used as an effective tool to predict the reservoir performance while applying seismic EOR technique. This model is developed by extending the wave induced fluid flow theory to account for the change in the reservoir characteristics as a result of wave application. A MATLAB program was developed based on the modified theory. The wave’s intensity, pressure, and energy dissipation spatial distributions are calculated. The portion of energy converted into thermal energy in the reservoir is assessed. The changes in reservoir properties due to temperature and pressure changes are considered. The incremental oil recovery and reduction in water production as a result of wave application are then calculated. The developed model was validated against actual performance of Liaohe oil field. The model results show that the wave application increases oil production from 33 to 47 ton/day and decreases water-oil ratio from 68 to 48%, which is close to the field measurements. A parametric analysis is performed to identify the important parameters that affect reservoir performance under seismic EOR. In addition, the study determines the optimum ranges of reservoir properties where this technique is most beneficial.

scholarly journals Chemo-mechanical Diffusion Waves Orchestrate Collective Dynamics of Immune Cell Podosomes

2021 ◽  
Author(s):  
Ze Gong ◽  
Koen van den Dries ◽  
Alessandra Cambi ◽  
Vivek Shenoy
Keyword(s):  
Actin Polymerization ◽  
Immune Cell ◽  
Wave Dynamics ◽  
Diffusion Waves ◽  
Mechanical Diffusion ◽  
Mechanical Waves ◽  
The Individual ◽  
The Impact ◽  
Cell Mechanosensing

Immune cells, such as macrophages and dendritic cells, can utilize podosomes, actin-rich protrusions, to generate forces, migrate, and patrol for foreign antigens. In these cells, individual podosomes exhibit periodic protrusion and retraction cycles (vertical oscillations) to probe their microenvironment, while multiple podosomes arranged in clusters demonstrate coordinated wave-like spatiotemporal dynamics. However, the mechanisms governing both the individual vertical oscillations and the coordinated oscillation waves in clusters remain unclear. By integrating actin polymerization, myosin contractility, actin diffusion, and mechanosensitive signaling, we develop a chemo-mechanical model for both the oscillatory growth of individual podosomes and wave-like dynamics in clusters. Our model reveals that podosomes show oscillatory growth when the actin polymerization-associated protrusion and the signaling-associated myosin contraction occur at similar rates, while the diffusion of actin monomers within the cluster drives mesoscale coordination of individual podosome oscillations in an apparent wave-like fashion. Our model predicts the influence of different pharmacological treatments targeting myosin activity, actin polymerization, and mechanosensitive pathways, as well as the impact of the microenvironment stiffness on the wavelengths, frequencies, and speeds of the chemo-mechanical waves. Overall, our integrated theoretical and experimental approach reveals how collective wave dynamics arise due to the coupling between chemo-mechanical signaling and actin diffusion, shedding light on the role of podosomes in immune cell mechanosensing within the context of wound healing and cancer immunotherapy.

NMR Characterization of Mechanical Waves

2004 ◽  
pp. 203-244 ◽  
Author(s):  
GUILLAUME MADELIN ◽  
NATHALIE BARIL ◽  
JACQUES DONALD DE CERTAINES ◽  
JEAN-MICHEL FRANCONI ◽  
ERIC THIAUDIÈRE
Keyword(s):  
Mechanical Waves ◽  
Nmr Characterization

Monitoring of Physiological Sounds with Wearable Device based on Piezoelectric MEMS Acoustic Sensor

2021 ◽  
Author(s):  
Mengjiao Qu ◽  
Xuying Chen ◽  
Dengfei Yang ◽  
Dongsheng Li ◽  
Ke Zhu ◽  
...  
Keyword(s):  
Microelectromechanical Systems ◽  
Myocardial Contraction ◽  
Low Noise ◽  
The Body ◽  
Wearable Device ◽  
Acoustic Sensor ◽  
Human Machine Interaction ◽  
Vocal Fold Vibration ◽  
Mechanical Waves ◽  
Silicone Polymers

Abstract Physiological mechano-acoustic signals play a pivotal role in medical diagnosis and fitness monitoring. Mechanical waves generated by natural physiological activities such as myocardial contraction, and vocal fold vibration, propagate through the tissues and fluids of the body and reveal characteristic signals of these events. Conventional methods such as stethoscope and electrocardiography (ECG) are not suitable for wearable mode and continuous monitoring. In this paper, we propose a wearable physiological sounds sensing device to monitor heart sound and detect speech and voice with high accuracy. The device consists of a MEMS (microelectromechanical systems) acoustic sensor and a low-noise amplification circuit, and both of them are packaged by silicone polymers with an air cavity to achieve conformal contact with human skin. The proposed device has advantages of light weight, sweatproof capability, resistant to noise and good stability. The wearable device has great potential in clinical diagnosis, healthcare, human-machine interaction and many other applications.

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