Investigations have been performed on various methods of increasing cavitation activity measured by the intensity of sonoluminescence. It is shown that the effect of the combined action of (a) pulsed modulation of an acoustic field, (b) liquid degassing and cooling and (c) increasing the static pressure considerably exceeds the sum of the effects achieved by each of these methods individually. A more than 250-fold increase of the sonoluminescence intensity has been attained compared with continuous irradiation under normal conditions (room temperature, atmospheric pressure, gas-saturated liquid). An interpretation of the results obtained is proposed.
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http://dx.doi.org/10.1016/s1350-4177(99)00023-1 | DOI Listing |
Ultrason Sonochem
December 2024
Third Institute of Physics, Georg-August-University Göttingen, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany. Electronic address:
Light emissions from cavitating liquids serve as a diagnostic tool for chemical activity, bubble collapse conditions, or excited species. Here we demonstrate the influence of mechanical stirring on sonoluminescence (SL) and sonochemiluminescence (SCL) emissions emerging in the presence of dissolved sodium salts and luminol in different sonicated liquids. In the systems investigated, driven in the 20-40 kHz range, stirring can change the spatial distribution of blue/white broadband SL emissions and of the orange sodium D-line emission, as well as their relative intensities.
View Article and Find Full Text PDFUltrason Sonochem
December 2024
Department of Aerospace and Mechanical Engineering, University of Southern California, Los Angeles, CA 90089, United States; Mork Family Department of Chemical Engineering and Material Science, University of Southern California, Los Angeles, CA 90089, United States; Alfred E. Mann Department of Biomedical Engineering, University of Southern California, Los Angeles, CA 90089, United States.
Sonodynamic therapy (SDT) is a minimally invasive targeted cancer therapy that uses focused low-intensity ultrasound (<10 MPa, <10 W/cm) to activate sonosensitizer drugs. Once activated, these chemical compounds generate reactive oxygen species (ROS) to damage and kill cancer cells. A Phase I clinical trial has shown promising results for treating glioblastoma with SDT.
View Article and Find Full Text PDFACS Nano
September 2024
Beckman Institute for Advanced Science and Technology, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, United States.
Photodynamic therapy (PDT) and sonodynamic therapy (SDT), using nonionizing light and ultrasound to generate reactive oxygen species, offer promising localized treatments for cancers. However, the effectiveness of PDT is hampered by inadequate tissue penetration, and SDT largely relies on pyrolysis and sonoluminescence, which may cause tissue injury and imprecise targeting. To address these issues, we have proposed a mechanochemical dynamic therapy (MDT) that uses free radicals generated from mechanophore-embedded polymers under mechanical stress to produce reactive oxygen species for cancer treatment.
View Article and Find Full Text PDFPolymers (Basel)
August 2024
School of Chemical Engineering, Yeungnam University, Gyeongsan 38541, Republic of Korea.
Ultrason Sonochem
December 2023
School of Chemistry and Chemical Engineering, University of Surrey, Guildford, Surrey GU2 7XH, United Kingdom. Electronic address:
The removal of per- and polyfluoroalkyl substance (PFAS) pollution from the environment is a globally pressing issue, due to some PFAS' recalcitrant, bioaccumulative, and carcinogenic nature. Destruction via ultrasonic waves (sonolysis) is a promising contender for industrialisation due to; moderate power consumption, applicability to several PFAS and sample types, and limited by-products. Liquid flow rate through an ultrasonic reactor can affect the size, shape, and spatial distribution of ultrasonic cavities and hence their chemical activity.
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