QPROP: A Schroedinger-solver for intense laser-atom interaction

The Qprop package is presented. Qprop has been developed to study laser-atom interaction in the nonperturbative regime where nonlinear phenomena such as above-threshold ionization, high order harmonic generation, and dynamic stabilization are known to occur. In the nonrelativistic regime and within the single active electron approximation, these phenomena can be studied with Qprop in the most rigorous way by solving the time-dependent Schr\"odinger equation in three spatial dimensions. Because Qprop is optimized for the study of quantum systems that are spherically symmetric in their initial, unperturbed configuration, all wavefunctions are expanded in spherical harmonics. Time-propagation of the wavefunctions is performed using a split-operator approach. Photoelectron spectra are calculated employing a window-operator technique. Besides the solution of the time-dependent Schr\"odinger equation in single active electron approximation, Qprop allows to study many-electron systems via the solution of the time-dependent Kohn-Sham equations.Comment: 40 pages, LaTeX; to obtain the QPROP source code visit http://www.qprop.de, accepted for publication in Computer Physics Communication

Relativistic central--field Green's functions for the RATIP package

From perturbation theory, Green's functions are known for providing a simple and convenient access to the (complete) spectrum of atoms and ions. Having these functions available, they may help carry out perturbation expansions to any order beyond the first one. For most realistic potentials, however, the Green's functions need to be calculated numerically since an analytic form is known only for free electrons or for their motion in a pure Coulomb field. Therefore, in order to facilitate the use of Green's functions also for atoms and ions other than the hydrogen--like ions, here we provide an extension to the Ratip program which supports the computation of relativistic (one--electron) Green's functions in an -- arbitrarily given -- central--field potential \rV(r). Different computational modes have been implemented to define these effective potentials and to generate the radial Green's functions for all bound--state energies $E < 0$. In addition, care has been taken to provide a user--friendly component of the Ratip package by utilizing features of the Fortran 90/95 standard such as data structures, allocatable arrays, or a module--oriented design.Comment: 20 pages, 1 figur

Nonsequential Double Recombination in Intense Laser Fields

A second plateau in the harmonic spectra of laser-driven two-electron atoms is observed both in the numerical solution of a low-dimensional model helium atom and using an extended strong field approximation. It is shown that the harmonics well beyond the usual cut-off are due to the simultaneous recombination of the two electrons, which were emitted during different, previous half-cycles. The new cut-off is explained in terms of classical trajectories. Classical predictions and the time-frequency analysis of the ab initio quantum results are in excellent agreement. The mechanism corresponds to the inverse single photon double ionization process in the presence of a (low frequency) laser field.Comment: 4 pages, RevTeX, v2 with an extended strong field approximation treatment of the process; instead, v1 describes an attosecond control scheme to enhance the proces

Analytical study of interior noise control by fuselage design techniques on high-speed, propeller-driven aircraft

The acoustical treatment mass penalties required to achieve an interior noise level of 80 dBA for high speed, fuel efficient propfan-powered aircraft are determined. The prediction method used is based on theory developed for the outer shell dynamics, and a modified approach for add-on noise control element performance. The present synthesis of these methods is supported by experimental data. Three different sized aircraft are studied, including a widebody, a narrowbody and a business sized aircraft. Noise control penalties are calculated for each aircraft for two kinds of noise control designs: add-on designs, where the outer wall structure cannot be changed, and advanced designs where the outer wall stiffness level and the materials usage can be altered. For the add-on designs, the mass penalties range from 1.7 to 2.4 percent of the takeoff gross weight (TOGW) of the various aircraft, similar to preliminary estimates. Results for advanced designs show significant reductions of the mass penalties. For the advanced aluminum designs the penalties are 1.5% of TOGW, and for an all composite aircraft the penalties range from 0.74 to 1.4% of TOGW

Online content impact on consumer behavior studies review: the case of internet booking agencies in Russia

The article is devoted to the analytical review of the scientific literature on studies of the influence of online content on consumer behavior. The author examines consumer behavior within the hospitality industry and tourism. As an outcome of the study made a number of hypotheses for the further confirmation by empirical analysis.Статья посвящена аналитическому обзору научной литературы, касающейся исследований влияния онлайн-контента на поведение потребителей. Рассматривается потребительское поведение в рамках индустрии гостеприимства и туризма. В качестве итога исследования сформулирован ряд гипотез для дальнейшего подтверждения эмпирическим анализом

Enhancement of Josephson phase diffusion by microwaves

We report an experimental and theoretical study of the phase diffusion in small Josephson junctions under microwave irradiation. A peculiar enhancement of the phase diffusion by microwaves is observed. The enhancement manifests itself by a pronounced current peak in the current-voltage characteristics. The voltage position $V_{\rm top}$ of the peak increases with the power $P$ of microwave radiation as $V_{\rm top}\propto\sqrt P$, while its current amplitude weakly decreases with $P$. As the microwave frequency increases, the peak feature evolves into Shapiro steps with finite slope. Our theoretical analysis taking into account the enhancement of incoherent superconducting current by multi-photon absorption is in good agreement with experimental data.Comment: 5 pages, 4 figure

LAPW frozen-phonon calculation, shell model lattice dynamics and specific-heat measurement of SnO

An ab-initio Linear Augmented Plane-Wave (LAPW) calculation of the zone-centered phonon frequencies of SnO has been performed. E$_g$ symmetry has been ascribed to the mode observed at 113 cm$^{-1}$ in Raman measurements, discarding a previous B$_{1g}$ assignement. The other phonon modes measured by Raman spectroscopy are also well reproduced. A new shell-model has also been developed, that gives good agreement of the zone-centered frequencies compared to the measured data and the LAPW results. Specific heat measurements have been performed between 5 K and 110 K. Computation of the specific heat and the M\"{o}ssbauer recoilless fraction with the improved shell-model shows a good agreement with the experimental data as a function of temperature.Comment: 11 pages, 1 figure. to appear in Phys. Rev. B (November 1999

LASER POLARIZATION-VARIABLE AUTOFLUORESCENCE OF THE NETWORK OF OPTICALLY ANISOTROPIC BIOLOGICAL TISSUES: DIAGNOSTICS AND DIFFERENTIATION OF EARLY STAGES OF CANCER OF CERVIX UTERI

This research presents the results of investigation of laser polarization fluorescence of biological layers (histological sections, cytological smears) in the task of diagnostics and differentiation of early stages of cancer: Dysplasia — cervical microinvasive carcinoma of cervix uteri. The analytical conditions of polarization-optimal probing of biological layers were determined basing on the model of linear birefringence and dichroism of birefringent (fibrillar, porphyrin) networks. The technique of polarization-variable laser autofluorescence was developed and experimentally tested. The objective criteria (statistical moments) of differentiation of histological sections autofluorescent images of endometrium biopsy and cytological smears of it mucous coat were defined. The operational characteristics (sensitivity, specificity, accuracy) of this technique were determined concerning the positions of probative medicine, and clinical efficiency

Construction waste recycling in the circular economy model

Publisher Copyright: © 2023 Institute of Physics Publishing. All rights reserved.The disposal of construction waste, the amount of which is constantly growing due to hostilities in Ukraine and outdated housing stock that has lost its consumer properties is an acute problem. The study proposes adopting the circular economy and the principles of improving the security and environmental situation in Ukraine to restore the country's potential. The article analyzes the main stages and processes of construction waste disposal, taking into account their fractional recycling and reuse in the reconstruction of settlements, which is based on the rational use of resources and innovations and will reduce the cost of restoring destroyed settlement areas. Efficient construction is possible only if environmental and economic indicators are improved, the level of safety and manufacturability are improved. A methodology for assessing the effectiveness of future construction has been developed and recommendations for its improvement have been given.publishersversionPeer reviewe