By periodically driving the temperature of reservoirs in a quantum heat engine, geometric or Pancharatnam-Berry phase-like (PBp) effects in the thermodynamics can be observed. The PBp can be identified from a generating function (GF) method within an adiabatic quantum Markovian master equation formalism. The GF is shown not to lead to a standard open quantum system's fluctuation theorem in presence of phase-different modulations with an inapplicability in the use of large deviation theory. Effect of quantum coherences in optimizing the flux is nullified due to PBp contributions. The linear coefficient, 1/2, which is universal in the expansion of the efficiency at maximum power in terms of Carnot efficiency no longer holds true in presence of PBp effects.

The green synthesis of metallic nanoparticles has tremendous impacts in various fields as found in recent years due to their low cost, easy and environmentally friendly synthesis. In this article, we report a simple and eco-friendly method for the synthesis of silver nanoparticles (AgNPs) using an aqueous Eupatorium adenophorum ( E. adenophorum ) leaf extract as a bioreductant. Interestingly, Fourier transform infrared (FTIR) spectroscopy analysis established that the E. adenophorum extract not only served as a bioreductant but also acted as a capping agent to stabilize the nanoparticles by functionalizing the surfaces. Various characterization techniques were adopted, such as X-ray powder diffraction (XRD), FTIR, ultraviolet–visible absorption (UV–Vis) spectroscopy, dynamic light scattering, scanning electron microscopy and energy-dispersive X-ray spectroscopy (EDX) to analyze the biosynthesized AgNPs. Biosynthesized nanoparticles were also explored for antioxidant, antibacterial and photocatalytic activities. The AgNPs showed improved free radical scavenging activity (IC 50 48.96 ± 0.84 µg/mL) and bacterial inhibitory effects against both gram-positive ( Staphylococcus aureus ; 64.5 µg/mL) and gram-negative ( Escherichia coli ; 82.5 µg/mL) bacteria. Photocatalytic investigation showed AgNPs were effective at degrading rhodamine dye (78.69% in 90 min) when exposed to sunlight. These findings collectively suggest that E. adenophorum AgNPs were successfully prepared without the involvement of any hazardous chemical and it may be an effective antibacterial, antioxidant and promising agent for the removal of hazardous dye from waste water produced by industrial dyeing processes.

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This Article provides new insights concerning the simulation of plasmon-driven chemical reactions using real-time TDDFT based on the tight-binding electronic structure code DFTB+, with applications to the dissociation of H 2 on octahedral silver and gold nanoparticles with 19−489 atoms. A new component of these calculations involves sampling a 300 K canonical ensemble to determine the distribution of possible outcomes of the calculations, and with this approach we are able to determine the threshold for dissociation as a function of laser intensity, wavelength, and nanocluster size. We show that the threshold intensity varies as an inverse power of nanocluster size, which makes it possible to extrapolate the results to sizes that are more typical of experimental studies. The intensities obtained from this extrapolation are around a factor of 100 above powers used in the pulsed experiments. This is a closer comparison of theory and experiment than has been obtained in previous real-time simulations, and the remaining discrepancy can be understood in terms of electromagnetic hot spots that are associated with cluster formation. We also compare the influence of plasmon excitation versus interband excitation on reaction thresholds, revealing that for silver clusters plasmon excitation leads to lower thresholds, but for gold clusters interband excitation is more effective. Our study also includes an analysis of charge transfer to and from the H 2 molecule, and a determination of orbital populations during and after the pulse, showing the correlation between metal excitations and the location of the antibonding level of H 2 .

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