1,121 research outputs found
Comment on "Critique and correction of the currently accepted solution of the infinite spherical well in quantum mechanics" by Huang Young-Sea and Thomann Hans-Rudolph
We comment on the paper "Critique and correction of the currently accepted
solution of the infinite spherical well in quantum mechanics" by Huang
Young-Sea and Thomann Hans-Rudolph, EPL 115, 60001 (2016) .Comment: 2 pages; Submitted to the Comments Section of EP
Understanding the dependence on the pulling speed of the unfolding pathway of proteins
The dependence of the unfolding pathway of proteins on the pulling speed is
investigated. This is done by introducing a simple one-dimensional chain
comprising units, with different characteristic bistable free energies.
These units represent either each of the modules in a modular protein or each
of the intermediate "unfoldons" in a protein domain, which can be either folded
or unfolded. The system is pulled by applying a force to the last unit of the
chain, and the units unravel following a preferred sequence. We show that the
unfolding sequence strongly depends on the pulling velocity . In the
simplest situation, there appears a critical pulling speed : for pulling
speeds
it is the pulled unit that unfolds first. By means of a perturbative expansion,
we find quite an accurate expression for this critical velocity.Comment: accepted for publication in JSTA
Lattice models for granular-like velocity fields: Finite-size effects
Long-range spatial correlations in the velocity and energy fields of a
granular fluid are discussed in the framework of a 1d lattice model. The
dynamics of the velocity field occurs through nearest-neighbour inelastic
collisions that conserve momentum but dissipate energy. A set of equations for
the fluctuating hydrodynamics of the velocity and energy mesoscopic fields give
a first approximation for (i) the velocity structure factor and (ii) the
finite-size correction to the Haff law, both in the homogeneous cooling regime.
At a more refined level, we have derived the equations for the two-site
velocity correlations and the total energy fluctuations. First, we seek a
perturbative solution thereof, in powers of the inverse of system size. On the
one hand, when scaled with the granular temperature, the velocity correlations
tend to a stationary value in the long time limit. On the other hand, the
scaled standard deviation of the total energy diverges, that is, the system
shows multiscaling. Second, we find an exact solution for the velocity
correlations in terms of the spectrum of eigenvalues of a certain matrix. The
results of numerical simulations of the microscopic model confirm our
theoretical results, including the above described multiscaling phenomenon
Finite-time adiabatic processes: derivation and speed limit
Obtaining adiabatic processes that connect equilibrium states in a given time
represents a challenge for mesoscopic systems. In this paper, we explicitly
show how to build these finite-time adiabatic processes for an overdamped
Brownian particle in an arbitrary potential, a system that is relevant both at
the conceptual and the practical level. This is achieved by jointly engineering
the time evolutions of the binding potential and the fluid temperature.
Moreover, we prove that the second principle imposes a speed limit for such
adiabatic transformations: there appears a minimum time to connect the initial
and final states. This minimum time can be explicitly calculated for a general
compression/decompression situation.Comment: Main text: 5 pages; 18 pages with appendices and references; major
revision with results for a general non-linear potential and study of
fluctuations added; Physical Review E in pres
Non-equilibrium memory effects: granular fluids and beyond
In this perspective paper, we look into memory effects in out-of-equilibrium
systems. To be concrete, we exemplify memory effects with the paradigmatic case
of granular fluids, although extensions to other contexts such as molecular
fluids with non-linear drag are also considered. The focus is put on two
archetypal memory effects: the Kovacs and Mpemba effects. In brief, the first
is related to imperfectly reaching a steady state -- either equilibrium or
non-equilibrium, whereas the second is related to reaching a steady state
faster despite starting further. Connections to optimal control theory thus
naturally emerge and are briefly discussed.Comment: Perspective paper for EPL, 7 pages, 6 figure
Photoproduction total cross section and shower development
The total photoproduction cross section at ultra-high energies is obtained
using a model based on QCD minijets and soft-gluon resummation and the ansatz
that infrared gluons limit the rise of total cross sections. This cross section
is introduced into the Monte Carlo system AIRES to simulate extended
air-showers initiated by cosmic ray photons. The impact of the new
photoproduction cross section on common shower observables, especially those
related to muon production, is compared with previous results
Conspiracy beliefs, regulatory self-efficacy and compliance with COVID-19 health-related behaviors: The mediating role of moral disengagement
Although recent studies on the 2019 coronavirus disease (COVID-19) have highlighted the negative effects of moral disengagement on intentions to comply with COVID-19 containment measures, little is known about the mediating role of moral disengagement in the relationship between regulatory self-efficacy in complying with the containment measures, beliefs in conspiracy theories and compliance with COVID-19 health-related behaviors. Data were collected from 1164 young adults (women, N = 796; 68.4%; mean age 25.60 ± 4.40 years) who completed an online survey from 15th May to 22nd June 2021. Results of the multi-group path analyses indicated that higher beliefs in conspiracy theories were associated with lower compliance with COVID-19 health-related behaviors, whereas higher self-efficacy beliefs in complying with the containment measures were associated with higher compliance with COVID-19 health-related behaviors. Moral disengagement significantly mediated the associations between beliefs in conspiracy theories, regulatory self-efficacy, and compliance with COVID-19 health-related behaviors. Finally, the tested model was gender-invariant. Findings suggest that public health authorities and social care professionals should promote interventions aimed at improving regulatory self-efficacy, emphasizing the moral significance of respecting or ignoring the recommended COVID-19 measures (e.g., physical distance in public), and enhancing people's concern for the potential harms of their immoral actions
Carbon nanodots as nanocarrier for Squaraines: an in vitro evaluation of their Photodynamic activity
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