7,289 research outputs found
Stochastic interest rates in the aggregate life cycle of permanent income cum rational expectations model
An estimation of a life cycle cum rational expectations model that allows for uncertain future interest rates. The results show that the model is strongly rejected using post World War II U.S. data.Rational expectations (Economic theory) ; Consumption (Economics) ; Income
A test of two views of the regulatory mechanism: Averch-Johnson and Joskow
A test of the Averech-Johnson and the Joskov models of the electric utility regulatory process.Electric utilities ; Industrial policy
Ultrafast dynamics in the vicinity of quantum light-induced conical intersections
Nonadiabatic effects appear due to avoided crossings or conical intersections
that are either intrinsic properties in field-free space or induced by a
classical laser field in a molecule. It was demonstrated that avoided crossings
in diatomics can also be created in an optical cavity. Here, the quantized
radiation field mixes the nuclear and electronic degrees of freedom creating
hybrid field-matter states called polaritons. In the present theoretical study
we go further and create conical intersections in diatomics by means of a
radiation field in the framework of cavity quantum electrodynamics (QED). By
treating all degrees of freedom, that is the rotational, vibrational,
electronic and photonic degrees of freedom on an equal footing we can control
the nonadiabatic quantum light-induced dynamics by means of conical
intersections. First, the pronounced difference between the the quantum
light-induced avoided crossing and the conical intersection with respect to the
nonadiabatic dynamics of the molecule is demonstrated. Second, we discuss the
similarities and differences between the classical and the quantum field
description of the light for the studied scenario
Quantum Control with Quantum Light of Molecular Nonadiabaticity
Coherent control experiments in molecules are often done with shaped laser
fields. The electric field is described classically and control over the time
evolution of the system is achieved by shaping the laser pulses in the time or
frequency domain. Moving on from a classical to a quantum description of the
light field allows to engineer the quantum state of light to steer chemical
processes. The quantum field description of the photon mode allows to
manipulate the light-matter interaction directly in phase-space. In this paper
we will demonstrate the basic principle of coherent control with quantum light
on the avoided crossing in lithium fluoride. Using a quantum description of
light together with the nonadiabatic couplings and vibronic degrees of freedoms
opens up new perspective on quantum control. We show the deviations from
control with purely classical light field and how back-action of the light
field becomes important in a few photon regime
Non-adiabatic dynamics of molecules in optical cavities
Strong coupling of molecules to the vacuum field of micro cavities can modify
the potential energy surfaces opening new photophysical and photochemical
reaction pathways. While the influence of laser fields is usually described in
terms of classical field, coupling to the vacuum state of a cavity has to be
described in terms of dressed photon-matter states (polaritons) which require
quantized fields. We present a derivation of the non-adiabatic couplings for
single molecules in the strong coupling regime suitable for the calculation of
the dressed state dynamics. The formalism allows to use quantities readily
accessible from quantum chemistry codes like the adiabatic potential energy
surfaces and dipole moments to carry out wave packet simulations in the dressed
basis. The implications for photochemistry are demonstrated for a set of model
systems representing typical situations found in molecules
Directional Degradation of Spectralon Diffuser Under Ionizing Radiation for Calibration of Space-Based Sensors
Assessment of the effect of Vacuum Ultra Violet (VUV) irradiation on the Bidirectional Reflectance Distribution Function (BRDF) of Spectralon is presented in this paper. The sample was a 99% white Spectralon calibration standard irradiated with VUV source positioned at 60o off the irradiation direction for a total of 20 hours. The BRDF before and after VUV irradiation was measured and compared at number of wavelengths in the UV, VIS and IR. Non-isotropic directional degradation of Spectralon diffuser under ionizing radiation was detected at different BRDF measurement geometries primarily at UV spectral range. The 8o directional/hemispherical reflectance of the same sample was also measured and compared from 200nm to 2500nm. Index Terms BRDF, Reflectance, Multiangular, Spectralon, Remote Sensin
Observaciones sobre el problema de la calibración de emulsiones fotográficas
Fil: Kowalewski, Valdemar J.. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina
Dried Protein Structure Revealed at the Residue Level by Liquid-Observed Vapor Exchange NMR
Water is key to protein structure and stability, yet the relationship between protein-water interactions and structure is poorly understood, in part because there are few techniques that permit the study of dehydrated protein structure at high resolution. Here, we describe liquid-observed vapor exchange (LOVE) NMR, a solution NMR-based method that provides residue-level information about the structure of dehydrated proteins. Using the model protein GB1, we show that LOVE NMR measurements reflect the fraction of the dried protein population trapped in a conformation where a given residue is protected from exchange with D2O vapor. Comparisons to solution hydrogen-deuterium exchange data affirm that the dried protein structure is strongly influenced by local solution stability and that the mechanism of dehydration protection exerted by the widely used protectant trehalose differs from its mechanism of stabilization in solution. Our results highlight the need for refined models of cosolute-mediated dehydration protection and demonstrate the ability of LOVE NMR to inform such models
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