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Feiyan Cai
Department of Physics and Astronomy
University of Mississippi
Shaping Sound Waves for Advanced Acoustic Tweezers: From Fundamentals to Biomedical Applications
Optical tweezers, recognized with the 2018 Nobel Prize in Physics,
have showcased exceptional capabilities in manipulating micro-
and nanoparticles. In comparison, acoustic tweezers provide
stronger radiation forces, greater penetration depth, and reduced
thermaldamage, making them particularly suitable for biological
applications, especially in vivo. Nonetheless, traditional
acoustic tweezers face several challenges such as long
wavelengths, diffraction limits, and rigid designs, limiting
their precision and broaderapplication in biomedicine. In this
presentation, I will share our advancements in shaping sound
waves for advanced acoustic tweezers and address these
challenges. First, we designed localized gradient acoustic field
to create a precise platform for high-throughputcellular
manipulation. Second, we developed 3D acoustic tweezers to enable
multidimensional manipulation in complex environments. Third, we
innovated structured resonant fields to facilitate controllable
trapping and releasing, laying the groundwork for targeteddrug
delivery near vascular stents. Finally, I will outline my vision
for ultrasound-assisted drug delivery, both in vivo and in vitro,
and explore the future development of on-demand acoustic tweezer
technologies tailored for practical medical applications.
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Ashoka Karunarathne
Department of Chemical Engineering
New Jersey Institute of Technology
Coupled Ultrasonic-adsorption Studies of Porous Materials
Nanoporous materials are widely used as adsorbents due to their
high surface area and tunable structural properties. Fluid
confinement in nanopores significantly affects the overall
properties of fluid-saturated porous media, as well as the
properties of theconfined fluids themselves. These properties
include the elasticity of both porous media and the confined
fluid. As a result, there has been growing interest to understand
the mechanisms of fluid confinement, the properties of confined
fluids, and their relationwith the overall properties of the
fluid-filled porous media. In this presentation, I will discuss
the utilization of a novel experimental setup that couples
ultrasonic diagnostic with adsorption isotherm measurement to
study the elastic properties of water-sorbingporous materials.
Our recent studies of nanoporous glass, carbon xerogel, and
mycelium-based polymer composites have demonstrated the use of
ultrasonic wave propagation characteristics through water-sorbing
porous media to evaluate elastic moduli of porousmaterials, the
spatial distribution of water saturation, and the elasticity of
water confined in nanopores. Lastly, I will discuss the
development of an advanced ultrasonic-adsorption system that
enables volumetric adsorption measurements with a broad rangeof
fluids, not limited to water but also including organic compounds
such as hydrocarbons and alcohols.
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Mourad Oudich
Department of Physics
University of Lorraine, France
Tailoring Acoustic Wave Propagation Using Phononic Crystals and Metamaterials;
Phononic crystals and Acoustic/elastic metamaterials are
artificial materials designed to manipulate sound and vibration
for a myriad of applications. These structured materials are
generally constructed by alternating materials with different
mechanical propertiesand/or geometrical features, or by
incorporating resonators, to either display acoustic bandgaps or
enable other exotic acoustic functionalities that are not
attainable with natural materials. In this seminar, I will
present some of the research projects Ihave conducted recently,
in which I delineate the physical background and applications of
elastic metamaterials. I will first share our investigations on
acoustic wave propagation in media with time-varying mechanical
properties, and how we can realize suchmedia with active devices.
Secondly, I will present a real application of metamaterials to
achieve wireless ultrasound energy and data transfer through
metallic barriers without direct contact. I will conclude the
talk with my current exploratory projectson phononic crystals at
the gigahertz regime and metamaterials used for sensing
applications.
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Tousif Islam
Kavli Institute for Theoretical Physics
University of California — Santa Barbara
Taming Eccentricity in Binary Black Hole Mergers
Efficient detection and characterization of gravitational wave
(GW) signals from binary black hole (BBH) mergers require
computationally efficient yet accurate models for radiation
(waveforms) and remnant properties. While highly accurate
data-driven models exist for quasi-circular “binaries”
enabling key discoveries, such as large remnant kick velocities
in “GW200129” modeling eccentric binaries still
remains a challenge. In this talk, I will discuss recent advances
in eccentric BBH modeling. Using high-precision numerical
relativity and perturbative simulations, I will identify a
universal effect of eccentricity on radiation-related quantities,
providing a basis for defining eccentricity and developing
efficient models. I will also demonstrate how eccentricity
introduces additional radiation modes (which were predicted using
Newtonian calculations decades ago) and describe their extraction
using data-driven and signal processing techniques. Finally, I
will present the first data-driven model for these eccentric
harmonics (as well as the full radiation content).
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Madusanka Madiligama
Department of Physics and Astronomy
University of Mississippi
Rapid 3D Mapping of Underwater Sound Speed Using Sea Surface Data-based Machine Learning Model
Accurate underwater sound speed data is crucial for acoustic
propagation modeling and applications such as sonar systems.
However, due to limited data availability and computational
constraints, conventional methods face challenges in providing
real-time, high-resolution mapping of three-dimensional (3D)
sound speed fields. This study presents a machine learning model
that leverages readily available sea surface temperature and
salinity data from satellite observations to rapidly and
accurately estimate 3D underwater sound speed. The model is
trained to capture the relationships between surface data and
subsurface sound speed, integrating spatial and temporal
variables. Validation against in-situ profiling and Argo float
measurements demonstrates the model’s ability to deliver
efficient, high-resolution 3D sound speed maps with reasonable
accuracy. This approach offers a significant advancement in
real-time underwater sound speed prediction, overcoming the
limitations of traditional methods. The results of acoustic
propagation modeling further suggest the model’s applicability for
various underwater operations involving low- to mid-frequency
acoustic sources, including detection, communication, and noise
propagation.
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Purnima Narayan
Department of Physics and Astronomy
University of Mississippi
Investigating the Impact of Strong Gravitational Lensing on Tests of General Relativity using Gravitational Waves
The detection of gravitational waves (GWs) from binary black hole
(BBH) coalescences has emerged as a powerful and unique tool for
probing the strong-field dynamics of general relativity (GR).
This study delves into the potential biases introduced by strong
gravitational lensing on tests of GR with GW signals, since this
effect is not accounted for in the current implementation of
these tests. We assess the response of four standard
LIGO-Virgo-KAGRA tests of GR to simulated strong gravitationally
lensed BBH signals. Our findings highlight the need to rule out
mimicking biases due to strong lensing before claiming a GR
deviation.
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Debasish Borah
Department of Physics
University of Pittsburg
Why do We Live in a Universe Filled with Matter and no Antimatter?
The visible part of the present Universe is composed of matter
only with negligible trace of antimatter. However, matter and
antimatter are two sides of the same coin, and the Big Bang
should not have had a preference for creating one type over
another. Therefore, the observed dominance of matter over
antimatter in the present Universe has led to a longstanding
puzzle in particle physics and cosmology. This talk will discuss
some solutions to this puzzle within beyond standard model
frameworks and the possibility of probing them at particle
physics as well as gravitational wave-based experiments.
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