Search results for "wave"
showing 10 items of 6009 documents
Tanatologičeskaâ problematika v povesti "Zlaâ večnostʹ" Georgiâ Peskova
2018
Pod pseudonimem Gieorgij Pieskow ukrywała się Elena Dejsza, przedstawicielka „młodszego pokolenia” pisarzy pierwszej fali emigracji rosyjskiej, autorka opowieści Zła wieczność (1932). W utworze istotne miejsce zajmuje problematyka tanatologiczna. Rozpatrywana jest ona w różnych aspektach: poruszany jest tu problem samobójstwa, odbieranego jako zwycięstwo nad śmiercią; sporo miejsca poświęca się immortologii — bibliotekarz ma obsesję na punkcie nieśmiertelności; zwraca się także uwagę na starzenie się jako zjawisko towarzyszące umieraniu; dokonuje się też zabójstwa. W sferze ideowo-tematycznej poruszany jest problem zagłady cywilizacji europejskiej. Na tanatologię artystyczną Gieorgija Piesk…
Density-Functional Tight-Binding Simulations of Curvature-Controlled Layer Decoupling and Band-Gap Tuning in Bilayer MoS2
2014
Monolayer transition-metal dichalcogenides (TMDCs) display valley-selective circular dichroism due to the presence of time-reversal symmetry and the absence of inversion symmetry, making them promising candidates for valleytronics. In contrast, in bilayer TMDCs both symmetries are present and these desirable valley-selective properties are lost. Here, by using density-functional tight-binding electronic structure simulations and revised periodic boundary conditions, we show that bending of bilayer MoS2 sheets breaks band degeneracies and localizes states on separate layers due to bendinginduced strain gradients across the sheets. We propose a strategy for employing bending deformations in b…
EXTRACORPOREAL SHOCK WAVE THERAPY (ESWT) IN CHRONIC LOW BACK PAIN: A SYSTEMATIC REVIEW OF RANDOMIZED CLINICAL TRIALS
2020
Background: Extracorporeal Shock Wave Therapy (ESWT) has become a popular tool to treat musculoskeletal disorders and chronic low back pain. Aim of the study: To review the current scientific literature and assess the utility of ESWT in treating chronic low back pain. Methods: This systematic review was conducted from November 2019 to January 2020. Its purpose was to determine what the effectiveness is of the various forms of ESWT for the treatment of chronic low back pain. The critical review of the literature on the use of ESWT in chronic low back was made using the scientifically recognized medical databases PubMed, MEDLINE, Physiotherapy Evidence Database (PEDro) and Web of Science Core…
The Aqua-Planet Experiment (APE): CONTROL SST Simulation
2013
Climate simulations by 16 atmospheric general circulation models (AGCMs) are compared on an aqua-planet, a water-covered Earth with prescribed sea surface temperature varying only in latitude. The idealised configuration is designed to expose differences in the circulation simulated by different models. Basic features of the aqua-planet climate are characterised by comparison with Earth. The models display a wide range of behaviour. The balanced component of the tropospheric mean flow, and mid-latitude eddy covariances subject to budget constraints, vary relatively little among the models. In contrast, differences in damping in the dynamical core strongly influence transient eddy amplitudes…
High-Sensitivity Whispering Gallery Mode Humidity Sensor Based on Glycerol Microdroplet Volumetric Expansion
2021
We demonstrate a highly sensitive whispering gallery mode (WGM) relative humidity (RH) sensor based on a glycerol microdroplet. WGMs were excited using a 760 nm tunable semiconductor laser. We used free space coupling, which is effective when using a liquid resonator. A detailed analysis of different parameters influencing the sensor’s characteristics (sensitivity, hysteresis, resolution, stability, and temperature) is presented. The sensitivity of the sensor is one of the highest reported (2.85 nm/% RH in the range 50–70% RH with the resolution 1 × 10−4% RH). This type of humidity sensor has several advantages, such as high sensitivity, extended lifetime, good repeatability, and low cost, …
Effect of the submerged vegetation distribution on flow characteristics and lateral dispersion: Experimental analysis at the apex section of a meande…
2020
Understanding of how the vegetation distribution influences flow patterns and turbulence structure is extremely important to analyse environmental processes as the sediment transport and the mixing of transported quantities. In the present paper attention is focused on the effect of flexible vegetation on flow characteristics and dispersion processes at the apex section of a large-amplitude meandering bend. The analysis is conducted with the aid of data collected in a laboratory meandering flume both in the absence of vegetation on the bed and in the presence of real and flexible vegetation on the bed. Results show that the presence of vegetation affects both the lateral dispersion coeffici…
Strictly correlated electrons approach to excitation energies of dissociating molecules
2019
In this work we consider a numerically solvable model of a two-electron diatomic molecule to study a recently proposed approximation based on the density functional theory of so-called strictly correlated electrons (SCE). We map out the full two-particle wave function for a wide range of bond distances and interaction strengths and obtain analytic results for the two-particle states and eigenenergies in various limits of strong and weak interactions, and in the limit of large bond distance. We then study the so-called Hartree-exchange-correlation (Hxc) kernel of time-dependent density functional theory which is a key ingredient in calculating excitation energies. We study an approximation b…
ULTRASONIC WAVES IN HETEROGENEOUS MATERIALS - MECHANICAL CHARACTERIZATION OF HETEROGENEOUS MATERIALS BY MEANS OF ULTRASONIC TESTS AND NUMERICAL MODEL…
2014
This Ph.D thesis treats the propagation of ultrasonic waves in heterogeneous materials. It is widely known how waves propagate in homogeneous materials like metallic ones. But very few aspects are known about the propagation in the heterogeneous materials because of the complex behavior regarding these materials. The heterogeneity can be related with the intrinsic properties, elastic and chemical, of each phase of the material, or with the periodic or random arrangement of inclusions of constant or different shapes. Concrete is a common case. In this work the first chapter gives a description of the main characteristics of heterogeneous materials.. In the second one, the methods of inspecti…
Compensation of Nonlinearity of Voltage and Current Instrument Transformers
2019
This paper aims at characterizing and improving the metrological performances of current and voltage instrument transformers (CTs and VTs) in harmonic measurements in the power system. A theoretical analysis is carried out to demonstrate that, due to the iron core nonlinearity, CT and VT output signal is distorted even when the input signal is a pure sine wave. Starting from this analysis, a new method for CT and VT characterization and compensation is proposed. In a first step, they are characterized in sinusoidal conditions and the harmonic phasors of the distorted output are measured; in the second step, these phasors are used to compensate the harmonic phasors measured in normal operati…
Associations of Sex Hormones and Hormonal Status With Arterial Stiffness in a Female Sample From Reproductive Years to Menopause
2021
ObjectiveLoss of sex hormones has been suggested to underlie menopause-associated increment in cardiovascular risk. We investigated associations of sex hormones with arterial stiffness in 19–58-years-old women. We also studied associations of specific hormonal stages, including natural menstrual cycle, cycle with combined oral contraceptives (COC) and menopausal status with or without hormone therapy (HT), with arterial stiffness.MethodsThis study includes repeated measurements of 65 healthy women representing reproductive (n=16 natural, n=10 COC-users) and menopause (n=5 perimenopausal, n=26 postmenopausal, n=8 HT-users) stages. Arterial stiffness outcomes were aortic pulse wave velocity (…