The velocity and absorption coefficient for the plane sound waves in a classical gas are obtained by solving the Boltzmann kinetic equation, which describes the reaction of the single-particle distribution function to a periodic external field. Within the linear response theory, the nonperturbative dispersion equation valid for all sound frequencies is derived and solved numerically. The results are in agreement with the approximate analytical solutions found for both the frequent- and rare-collision regimes. These results are also in qualitative agreement with the experimental data for ultrasonic waves in dilute gases.
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http://dx.doi.org/10.1103/PhysRevE.96.062142 | DOI Listing |
Bioelectromagnetics
April 2025
Care & Cure Lab of the Electromagnetics Group (EM4Care+Cure), Department of Electrical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands.
Neuromodulation with low-intensity focused ultrasound (LIFUS) holds significant promise for noninvasive treatment of neurological disorders, but its success relies heavily on accurately targeting specific brain regions. Computational model predictions can be used to optimize LIFUS, but uncertain acoustic tissue properties can affect prediction accuracy. The Monte Carlo method is often used to quantify the impact of uncertainties, but many iterations are generally needed for accurate estimates.
View Article and Find Full Text PDFSovrem Tekhnologii Med
March 2025
PhD, Leading Researcher; Institute of Theoretical and Experimental Biophysics of the Russian Academy of Sciences, 3 Institutskaya St., Pushchino, 142290, Russia; Senior Researcher; Institute for Biological Instrumentation of the Russian Academy of Sciences, 7 Institutskaya St., Pushchino, 142290, Russia.
This study investigates the role of porosity in silicon nanoparticles' ability to act as sonosensitizers for sonodynamic therapy of malignant tumors. Structural analysis showed that porous nanoparticles are composed of nanocrystals approximately 4 nm in size and contain 15 nm pores, whereas non-porous nanoparticles have a dense structure with nanocrystals ranging from 10 to 50 nm. Porous nanoparticles exhibit pronounced photoluminescent properties, associated with quantum confinement effects in their small nanocrystals.
View Article and Find Full Text PDFUltrasonics
March 2025
State Key Laboratory for Manufacture Systems Engineering, Xi'an Jiaotong University, Xi'an, China; International Joint Laboratory for Micro/nano Manufacturing and Measurement Technology, Xi'an Jiaotong University, Xi'an, China. Electronic address:
Laser powder bed fusion (LPBF) is widely employed in metal additive manufacturing to fabricate components with outstanding mechanical properties and precise dimensions by melting powder layer-by-layer. As an in-line monitoring technique for additive manufacturing (AM), laser ultrasonic testing (LUT) is expected to be effective. During the LPBF process, ultrasonic signals are affected by thickness variations of specimens.
View Article and Find Full Text PDFUltrasonics
March 2025
Instituto de Ciencias Físicas, Universidad Nacional Autónoma de México, 62210 Cuernavaca, Mexico. Electronic address:
Airborne acoustic levitation has seen great advances in recent years largely due to the development of devices utilizing arrays of compact, low-power, piezoelectric transducers. In particular, standing wave acoustic levitators are acoustic cavities, consisting of either a single piezoelectric boundary opposing a reflector or two opposing piezoelectric boundaries operating simultaneously. The multiple intra-cavity reflections can be significant enough to generate voltages and currents at the electrical port due to the direct piezoelectric effect, providing valuable information about the optimal operating conditions of the cavity.
View Article and Find Full Text PDFInt J Nanomedicine
March 2025
Department of Ultrasound, the Affiliated Hospital of Qingdao University, Qingdao, 266003, People's Republic of China.
Introduction: Triple-negative breast cancer (TNBC) is known for its high malignancy, limited clinical treatment options, and poor chemotherapy outcomes. Although some advancements have been made using nanotechnology-based chemotherapy for TNBC treatment, the controlled and on-demand release of chemotherapeutic drugs at the tumor site remains a challenge.
Methods: We manufactured DOX/BaTiO@cRGD-Lip (DBRL) nanoparticles as an ultrasound (US)-controlled release platform targeting the delivery of Doxorubicin (DOX) for TNBC treatment.
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