Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

English (EN)·Polski (PL)·Yкраїнський (UK)
Przejdź do strony domowej biblioteki Centralna Biblioteka Wojskowa Link otwiera się w nowym oknie Logo biblioteki Prolib Integro - strona głównaCentralna Biblioteka Wojskowa

Wyszukujesz frazę "dispersion equation" wg kryterium: Temat

  Lista filtrów
Wyrównaj
    Wyświetlanie 1-10 z 10
    Tytuł:
    Wave propagation in nonlocal orthotropic micropolar elastic solids
    Autorzy:
    Tung, D. X.
    Powiązania:
    https://bibliotekanauki.pl/articles/38626486.pdf
    Data publikacji:
    2021
    Wydawca:
    Instytut Podstawowych Problemów Techniki PAN
    Tematy:
    dispersion equation
    nonlocal micropolar
    local micropolar
    orthotropic
    Opis:
    The presented paper is concerned with the propagation of Rayleigh waves in an orthotropic nonlocal micropolar elastic half-space. The main aim of the paper is to derive dispersion equations of Rayleigh wave as well as Stroh formalism for the orthotropic nonlocal micropolar medium. Based on the obtained dispersion equation, the effect of material, nonlocality parameter on the Rayleigh wave propagation is considered through some numerical examples.
    Źródło:
    Archives of Mechanics; 2021, 73, 3; 237-251
    0373-2029
    Pojawia się w:
    Archives of Mechanics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    New Theoretical Model for Mass Sensitivity of Love Wave Sensors
    Autorzy:
    Kiełczyński, Piotr
    Szalewski, Marek
    Balcerzak, Andrzej
    Wieja, Krzysztof
    Powiązania:
    https://bibliotekanauki.pl/articles/1953518.pdf
    Data publikacji:
    2021
    Wydawca:
    Polska Akademia Nauk. Czasopisma i Monografie PAN
    Tematy:
    Love wave sensors
    mass sensitivity
    complex dispersion equation
    viscoelastic layers
    Opis:
    In this work we analyse basic characteristics of Love wave sensors implemented in waveguide structures composed of a lossy viscoelastic surface layer deposited on a lossless elastic substrate. It has to be noted that Love wave sensors working at ultrasonic frequencies have the highest mass density sensitivity Sσvp among all known ultrasonic sensors, such as QCM, Lamb wave or Rayleigh wave sensors. In this paper we have established an exact analytical formula for the mass density sensitivity Sσvp of the Love wave sensors in the form of an explicit algebraic expression. Subsequently, using this developed analytical formula, we compared theoretically the mass density sensitivity Sσvp for various Love wave waveguide structures, such as: (1) lossy PMMA surface layer on lossless Quartz substrate and (2) lossy PMMA on lossless Diamond substrate. The performed analysis shows that the mass density sensitivity Sσvp (real and imaginary part) for a sensor with a structure PMMA on Diamond is five times higher than that of a PMMA on Quartz structure. It was found that the mass density sensitivity Sσvp for Love wave sensors increases with the increase of the ratio: bulk shear wave velocity in the substrate to bulk shear wave velocity in the surface layer.
    Źródło:
    Archives of Acoustics; 2021, 46, 1; 17-24
    0137-5075
    Pojawia się w:
    Archives of Acoustics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    The CFD modeling in bioreactor tracer studies
    Autorzy:
    Zima, P.
    Powiązania:
    https://bibliotekanauki.pl/articles/1933153.pdf
    Data publikacji:
    2007
    Wydawca:
    Politechnika Gdańska
    Tematy:
    mathematical modeling
    pollutant migration
    reactor hydraulics
    advection-dispersion equation
    tracer studies
    Opis:
    This paper presents the effects of dispersion on predicting longitudinal tracer concentration profiles in an activated sludge bioreactor located at the Wschód Waste-Water Treatment Plant in Gdansk. The aim of this study has been to use the one-dimensional advection-dispersion equation to simulate a non-active substance flow (based on the measured tracer concentration). The simulation results were compared with those obtained in the traditional tanks-in-series approach, commonly used in designing biological reactors. The dispersion coefficient was calculated from a statistical formula based on differences in the tracer concentration distributions at two sampling points. The study has shown that the numerical simulation using the one-dimensional tracer migration equation yields better results than the tanks-in-series model in predicting longitudinal tracer concentration profiles. This paper is an in-troduction to the study of reactive substances in activated sludge bioreactors.
    Źródło:
    TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 2007, 11, 4; 439-447
    1428-6394
    Pojawia się w:
    TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    The effect of viscosity and heterogeneity on propagation of G-type waves
    Autorzy:
    Gupta, Shishir
    Smita, Smita
    Powiązania:
    https://bibliotekanauki.pl/articles/907648.pdf
    Data publikacji:
    2017
    Wydawca:
    Uniwersytet Zielonogórski. Oficyna Wydawnicza
    Tematy:
    G-type wave
    dispersion equation
    heterogeneity
    fala typu G
    równanie dyspersji
    niejednorodność
    Opis:
    Earthquakes yield motions of massive rock layers accompanied by vibrations which travel in waves. This paper analyses the possibility of G-type wave propagation along the plane surface at the interface of two different media which is assumed to be heterogeneous and viscoelastic. The upper layer is considered to be viscoelastic and the lower half space is considered to be an initially stressed heterogeneous half space. The dispersion equation, as well as the phase and group velocities, is obtained in closed form. The dispersion equation agrees with the classical Love type wave. The effects of the nonhomogeneity of the parameters and the initial stress on the phase and group velocities are expressed by means of a graph.
    Źródło:
    International Journal of Applied Mathematics and Computer Science; 2017, 27, 2; 253-260
    1641-876X
    2083-8492
    Pojawia się w:
    International Journal of Applied Mathematics and Computer Science
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Effects of warmness and spatial nonuniformity of plasma waveguide on periodic absolute parametric instability
    Autorzy:
    Zaki, N. G.
    Bekheit, A. H.
    Powiązania:
    https://bibliotekanauki.pl/articles/147605.pdf
    Data publikacji:
    2011
    Wydawca:
    Instytut Chemii i Techniki Jądrowej
    Tematy:
    periodic absolute parametric instability (API)
    low frequency waves
    warm plasma
    growth rate
    dispersion equation
    Opis:
    The periodic absolute parametric instability (API) of the low-frequency oscillations excited by a monochromatic pumping field of an arbitrary amplitude in a warm 1-D (one-dimensional) nonuniform magnetoactive plasma is investigated. The separation method can be used for solving the two-fluid plasma equations describing the system. By applying this method we were able to determine the frequencies and growth rates of unstable modes and the self-consistent electric field. Plasma electrons are considered to have a thermal velocity. Different solutions for the spatial equation can be obtained the following cases: A) API in a uniform plasma, B) API in a nonuniform plasma. The latter has been studied here for two cases: B.1) the exact harmonic oscillator and B.2) the bounded harmonic oscillator (a bounded plasma). An increment has been found in the build-up of the oscillations, and it has been shown that the spatial nonuniformity of the plasma exerts the stabilizing effect on the parametric instability. A reduced growth rate of API in the warm plasma, in comparison to the cold plasma, is reported. It has also been found that the warmness of the plasma has no effect on the solution of the space part of the problem (only through the separation constant).
    Źródło:
    Nukleonika; 2011, 56, 4; 305-309
    0029-5922
    1508-5791
    Pojawia się w:
    Nukleonika
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Rayleigh wave propagation in isotropic sandy layer sliding over isotropic sandy semi-infinite medium with sliding contact
    Autorzy:
    Madan, Dinesh Kumar
    Kumar, Naveen
    Rani, Annu
    Powiązania:
    https://bibliotekanauki.pl/articles/45424000.pdf
    Data publikacji:
    2023
    Wydawca:
    Uniwersytet Zielonogórski. Oficyna Wydawnicza
    Tematy:
    fala Rayleigha
    równanie dyspersji
    prędkość fazowa
    Rayleigh wave
    sandy layer
    imperfect interface
    dispersion equation
    phase velocity
    Opis:
    The present study aims to investigate Rayleigh wave propagation in an isotropic sandy layer overlying an isotropic sandy semi-infinite medium, with interface considered to be imperfect (slide contact and dislocation like model). Expressions for displacement components are obtained using the variable separation method. The dispersion frequency equation for the Rayleigh wave propagating in sandy media is derived using suitable boundary conditions. Particular cases, such as when the interface is in smooth contact and when sandy media are replaced by elastic media, are also discussed. Using MATLAB software, the effects of the imperfectness parameter (slide contact and dislocation like model) and sandy parameter on the Rayleigh waves’ phase velocity are investigated and compared with the already obtained results of the dislocation like model. The present study may find useful applications in geophysics, civil engineering and soil mechanics.
    Źródło:
    International Journal of Applied Mechanics and Engineering; 2023, 28, 1; 58-70
    1734-4492
    2353-9003
    Pojawia się w:
    International Journal of Applied Mechanics and Engineering
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Derivation of the kinetic equation for dispersed particles in turbulent flows
    Wprowadzenie równania kinetycznego dla cząstek w turbulentnym przepływie dwufazowym
    Autorzy:
    Pozorski, J.
    Powiązania:
    https://bibliotekanauki.pl/articles/280061.pdf
    Data publikacji:
    1998
    Wydawca:
    Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
    Tematy:
    turbulence
    particle dispersion
    kinetic equation
    Opis:
    An alternative way to obtain the kinetic equation for dispersed particles in turbulent flows is presented. The method uses some tools developed within the theory of the stochastic differential equations. They are presented first in an outline, including the cumulant expansion of linear stochastic equations as well as the approach to non-linear equations. Then, the general method is applied to the equation of motion of small particles in turbulent flows. The governing kinetic equation for particles is derived; it involves the correlations of the fluctuating fluid velocity along the particle trajectories.
    W pracy przedstawiono alternatywny sposób wyprowadzenia równania kinetycznego dla cząstek w turbulentnym przepływie dwufazowym. Wykorzystano metody rozwinięte w ramach teorii stochastycznych równań różniczkowych. Przedstawiono je w zarysie, łącznie z rozwinięciem liniowych i nieliniowych równań stochastycznych w szereg półniezmienników (kumulantów). Następnie, to ogólne podejście zastosowano do równania ruchu małych cząstek w przepływie turbulentnym i wyprowadzono odpowiadające mu równanie kinetyczne. Zawiera ono korelacje fluktuacji prędkości płynu wzdłuż trajektorii cząstek.
    Źródło:
    Journal of Theoretical and Applied Mechanics; 1998, 1; 31-46
    1429-2955
    Pojawia się w:
    Journal of Theoretical and Applied Mechanics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Two-dimensional model of fluid flow and distribution of nutrient concentration in a microfluidic device
    Autorzy:
    Wroniszewski, P.
    Powiązania:
    https://bibliotekanauki.pl/articles/1934016.pdf
    Data publikacji:
    2011
    Wydawca:
    Politechnika Gdańska
    Tematy:
    microfluidic device
    lab-on-a-chip
    advection-diffusion equation
    Taylor dispersion
    Opis:
    During the past few years, the process of miniaturisation in the field of biochemical laboratory equipment led to the introduction of the so-called "lab-on-a-chip" microdevices, which combine separate functional units into a complex, multifunctional apparatus. Fluid dynamics plays an essential role in the development of such equipment, since frequently the major part of chemical analysis is based on soluble analytes. In this work, we consider a device for the analysis of cell growth under different conditions. In this device, dozens of cell spots absorb the nutrient (analyte) from the liquid medium. The concentration of the analyte must be strictly controlled to maintain a specific microenvironment. A two-dimensional model for the flow field and the distribution of concentration of the analyte is developed taking into account the geometrical shape of the spot with a simplified absorption model. The dependence of the results on the controlling parameters is investigated in order to determine the influence of the presence of the cell spot on the distribution of the analyte.
    Źródło:
    TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 2011, 15, 2; 135-155
    1428-6394
    Pojawia się w:
    TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Extended elliptic mild slope equation incorporating the nonlinear shoaling effect
    Autorzy:
    Xiao, Q. L.
    Li, Ch. H.
    Fu, X. Y.
    Wang, M. J.
    Powiązania:
    https://bibliotekanauki.pl/articles/258718.pdf
    Data publikacji:
    2016
    Wydawca:
    Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
    Tematy:
    nonlinear dispersion relation
    nonlinear shoaling coefficient
    extended elliptic mild slope equation
    surf zone
    wave transformation
    Opis:
    The transformation during wave propagation is significantly important for the calculations of hydraulic and coastal engineering, as well as the sediment transport. The exact wave height deformation calculation on the coasts is essential to near-shore hydrodynamics research and the structure design of coastal engineering. According to the wave shoaling results gained from the elliptical cosine wave theory, the nonlinear wave dispersion relation is adopted to develop the expression of the corresponding nonlinear wave shoaling coefficient. Based on the extended elliptic mild slope equation, an efficient wave numerical model is presented in this paper for predicting wave deformation across the complex topography and the surf zone, incorporating the nonlinear wave dispersion relation, the nonlinear wave shoaling coefficient and other energy dissipation factors. Especially, the phenomenon of wave recovery and second breaking could be shown by the present model. The classical Berkhoff single elliptic topography wave tests, the sinusoidal varying topography experiment, and complex composite slopes wave flume experiments are applied to verify the accuracy of the calculation of wave heights. Compared with experimental data, good agreements are found upon single elliptical topography and one-dimensional beach profiles, including uniform slope and step-type profiles. The results indicate that the newly-developed nonlinear wave shoaling coefficient improves the calculated accuracy of wave transformation in the surf zone efficiently, and the wave breaking is the key factor affecting the wave characteristics and need to be considered in the nearshore wave simulations.
    Źródło:
    Polish Maritime Research; 2016, S 1; 44-51
    1233-2585
    Pojawia się w:
    Polish Maritime Research
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Statistical analysis of gaz-3110 vehicles noise
    Autorzy:
    Pobedin, A.
    Kosov, O.
    Dolotov, A.
    Domolazov, F.
    Powiązania:
    https://bibliotekanauki.pl/articles/246122.pdf
    Data publikacji:
    2009
    Wydawca:
    Instytut Techniczny Wojsk Lotniczych
    Tematy:
    vehicle
    statistics
    noise sources
    dimension
    mean-root square dispersion
    noise level
    regression equation
    engine rpm speed
    useful life
    Opis:
    This work presents the results of the statistical analysis of noise in several points of GAZ-3110 vehicles. There are also the dependences between the loudness of noise and speed of an engine or useful life of a car. It is difficult to confuse the noise of jet engine with reciprocating internal-combustion engine. Random factors also influence much the power level. Mechanism adjustment has its limits and so it can have different influence on its vibration and noise. Finally during the process of operation sliding surfaces do wear, screwed connections do loosen, other things happen and these lead to the changes in spectrum and level of noise. In this work we tried to evaluate the dispersion of GAZ-3110 vehicles noise levels according to the results of a coustic measurements in the immediate field of rondom acoustically active constructive assemblies. The range of noise loudness for the specific car model is defined at the level 20-25 dBA. The GAZ-3110 vehicles are characterized by the significant dispersion of noise level. The differences of noise level of individual cars are exceeding 20-25 dBA. vehicles noise considerably increases with the augmentation of useful life and rpm speed. The noisiest element of GAZ-3110 vehicles is internal combustion engine, then main gear even when first gear is operated.
    Źródło:
    Journal of KONES; 2009, 16, 1; 407-410
    1231-4005
    2354-0133
    Pojawia się w:
    Journal of KONES
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
      Wyświetlanie 1-10 z 10

      Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies