The interaction of a 3x10;{19} W/cm;{2} laser pulse with a metallic wire has been investigated using proton radiography. The pulse is observed to drive the propagation of a highly transient field along the wire at the speed of light. Within a temporal window of 20 ps, the current driven by this field rises to its peak magnitude approximately 10;{4} A before decaying to below measurable levels. Supported by particle-in-cell simulation results and simple theoretical reasoning, the transient field measured is interpreted as a charge-neutralizing disturbance propagated away from the interaction region as a result of the permanent loss of a small fraction of the laser-accelerated hot electron population to vacuum.
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http://dx.doi.org/10.1103/PhysRevLett.102.194801 | DOI Listing |
Mol Biol Evol
January 2025
Professor Emeritus, School of Biological Sciences, Integrated Cancer Research Center, Georgia Institute of Technology, Atlanta, GA, USA.
The molecular basis of adaptive evolution and cancer progression are both complex processes that share many striking similarities. The potential adaptive significance of environmentally-induced epigenetic changes is currently an area of great interest in both evolutionary and cancer biology. In the field of cancer biology intense effort has been focused on the contribution of stress-induced non-coding RNAs (ncRNAs) in the activation of epigenetic changes associated with elevated mutation rates and the acquisition of environmentally adaptive traits.
View Article and Find Full Text PDFCardiol Rev
December 2024
Departments of Cardiology and Medicine, Westchester Medical Center, New York Medical College, Valhalla, NY.
J Acoust Soc Am
January 2025
Escola Politécnica, University of São Paulo, São Paulo, 05508-030, Brazil.
Ultrasonic sensors based on backscattering principles have been developed for various applications involving arbitrary or random scatterer distributions. Although the theory of multiple scattering of waves is well-established, it has not been thoroughly explored in these applications. This work presents a feasible and simplified three-dimensional scattering model to predict the transient response generated by a set of rods positioned in the near field of a 1 MHz water-coupled ultrasonic transducer.
View Article and Find Full Text PDFACS Omega
December 2024
Department of Chemical and Petroleum Engineering, Sharif University of Technology, Tehran 1458889694, Iran.
We present a novel approach for enhancing photocatalytic efficiency by developing polyaniline (PANI) and polyindole (PIN)-coated TiO nanotubes (TNT) through a combination of chemical oxidation and hydrothermal processes. The PANI-PIN coating was systematically applied to both the internal and external surfaces of the nanotubes to enhance the photocatalytic active sites and optimize pollutant adsorption. The dual-coated structure enhances the interaction with pollutants, facilitating a more efficient degradation of 4-nitrophenol (4-NP) when exposed to visible light.
View Article and Find Full Text PDFPhys Rev Lett
December 2024
Department of Physics and Astronomy, University of Nebraska, Lincoln, Nebraska 68588, USA.
Negative capacitance (NC) effects in ferroelectrics can potentially break fundamental limits of power dissipation known as "Boltzmann tyranny." However, the origin of transient NC of ferroelectrics, which is attributed to two different mechanisms involving free-energy landscape and nucleation, is under intense debate. Here, we report the coexistence of transient NC and an S-shaped anomaly during the switching of ferroelectric hexagonal ferrites capacitor in an RC circuit.
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