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Tytuł:
Investigation of signals of the range 10-3 - 10-4 Hz registered by water-tube tiltmeters in the underground geodynamic laboratory in Książ (SW Poland)
Autorzy:
Kaczorowski, Marek
Kasza, Damian
Zdunek, Ryszard
Wronowski, Roman
Powiązania:
https://bibliotekanauki.pl/articles/2174941.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Centrum Badań Kosmicznych PAN
Tematy:
interferometry
time series analysis
tides
planetary waves
acoustic gravity waves
surface waves
free oscillations
ionosphere interactions
atmosphere interactions
Opis:
The Geodynamic Laboratory in Książ includes investigations of various kinds of geodynamic signals. Among others, we registered harmonic signals of the range 10-3 - 10-4 Hz. These signals had been found in the measurement series of the long water-tube (WT) tiltmeters. The discovered signals consist of two classes of harmonics associated with various kinds of phenomena. The first class of these signals belongs to viscoelastic vibrations of the Earth’s solid body, while the second class is produced possibly by the extremely long atmospheric infrasound waves. The signals of the vibrations of the Earth had been well recognized by the characteristic frequencies of the Earth’s free vibrations’ resonance, which occur mainly after strong earthquakes. The atmospheric pressure microvibrations affected the water level in the hydrodynamic systems of the WTs as a result of an inverse barometric effect. We observed that signals from both classes blend in the harmonics of similar frequencies and jointly affect the hydrodynamic systems of the WTs. We found that the amplitude of the secondclass signals strongly depends on the location of water-tube gauges inside the underground, while the amplitudes of the first-class signals are similar for all the gauges. These observations clearly indicate the atmospheric origin of the second class of registered signals.
Źródło:
Artificial Satellites. Journal of Planetary Geodesy; 2022, 57, 4; 210--236
2083-6104
Pojawia się w:
Artificial Satellites. Journal of Planetary Geodesy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
New Surface-Plasmon-Polariton-Like Acoustic Surface Waves at the Interface Between Two Semi-Infinite Media
Autorzy:
Kiełczyński, Piotr
Powiązania:
https://bibliotekanauki.pl/articles/31340115.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
shear horizontal acoustic waves
surface plasmon polaritons
phase velocity
group velocity
Poynting vector
Opis:
This paper presents theory of new shear horizontal (SH) acoustic surface waves that propagate along the interface of two semi-infinite elastic half-spaces, one of which is a conventional elastic medium and a second one an elastic metamaterial with a negative and frequency dependent shear elastic compliance. This new surface waves have only one transverse component of mechanical displacement, which has a maximum at the interface and decays exponentially with distance from the interface. Similar features are also shown by the acoustic shear horizontal Maerfeld-Tournois surface waves propagating at the interface of two semi-infinite elastic media due to the piezoelectric effect that should occur in at least one semi-space. The proposed new shear horizontal acoustic surface waves exhibit also strong formal similarities with the electromagnetic surface waves of the surface plasmon polariton (SPP) type, propagating along a metal-dielectric planar interface. In fact, the new shear horizontal elastic surface waves possess a large number of properties that are inherent for the SPP electromagnetic surface waves, such as strong subwavelength concentration of the wave field in the proximity of the guiding interface, low phase and group velocity etc. As a result, the new shear horizontal acoustic surface waves can find applications in sensors with extremely high sensitivity, employed in measurements of various physical parameters, such as viscosity of liquids, as well as in biosensors, chemosensors, or a near field acoustic microscopy (subwavelength imaging) and miniaturized devices of microwave acoustics.
Źródło:
Archives of Acoustics; 2022, 47, 3; 363-371
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Measurements and numerical modelling of surface waves in front of the port of split
Autorzy:
Leder, N.
Duplančić Leder, T.
Lončar, G.
Powiązania:
https://bibliotekanauki.pl/articles/116487.pdf
Data publikacji:
2020
Wydawca:
Uniwersytet Morski w Gdyni. Wydział Nawigacyjny
Tematy:
activities in port area
numerical modelling
surface waves
port of split
Bracki Kanal Channel
Adriatic Sea
Aladin-CRO Model
sirocco
Opis:
Wind generated surface waves were measured at V2 station (φ=43°29.3’ N; λ=16° 27.9’ E) in the Brački Kanal Channel area of the Middle Adriatic, in front of the port of Split. This was undertaken in the time interval from November 2007 to June 2008, by using Datawell MKIII waverider with all its compo-nents. For the analysis and description of extreme sea states maximum recorded wave height Hmax and sig-nificant wave height H1/3 were presented as well as associated wave spectra. The measurement results show that much larger waves appear in the open Adriatic compared to the Middle Adriatic channel area. Numerical modelling of wave generation in the Brački Kanal Channel area and wider island area of the Middle Adriatic Sea was performed by using Mike 21/SW numerical model. Wind field used for the forcing in numerical simulations relies on the results of the prognostic atmospheric model Aladin-CRO. For verification of model results, results of measurement at a waverider station V2 located in front of the port of Split were used. It was concluded that measured and modelled significant wave heights were very well matched.
Źródło:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation; 2020, 14, 1; 191-197
2083-6473
2083-6481
Pojawia się w:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
O możliwości prowadzenia poprzecznej fali powierzchniowej w warstwie sprężystej układów regularnych z periodycznymi niejednorodnościami materiałowymi
On the possibility of surface transversal wave guidance in an elastic subsurface layer of cubic crystal systems with periodic material inhomogeneities
Autorzy:
Kapelewski, Jerzy
Pasternak, Mateusz
Powiązania:
https://bibliotekanauki.pl/articles/1857075.pdf
Data publikacji:
2020
Wydawca:
Wojskowa Akademia Techniczna im. Jarosława Dąbrowskiego
Tematy:
fale powierzchniowe poprzeczne
powierzchnie z periodycznym rozkładem niejednorodności
prowadnice falowe
surface transversal waves
surfaces with periodic inhomogeneities distributions
waveguides
Opis:
W pracy opisano możliwość prowadzenia poprzecznych fal powierzchniowych w warstwie sprężystej z wprowadzonymi sztucznie periodycznymi niejednorodnościami materiałowymi. Fale takie w odróżnieniu od modów prowadzonych w warstwie sprężystej lub utrzymywanych przy powierzchni piezoelektryka za pomocą ciągłego lub periodycznego jej zwarcia elektrycznego mogą charakteryzować się wyższą energią oraz prędkością, czyli parametrami istotnymi dla zastosowań sensorowych. Opisano zarys teorii, wybrane jakościowe aspekty propagacji tego typu fal na powierzchni kryształów regularnych, a także wstępne wyniki prób eksperymentalnych.
In the paper, the possibility of surface transversal waves existence on an elastic surface layer with artificially induced periodic inhomogeneities has been described. Such kind of waves, unlike well-known surface modes sustained close to the surface boundary by an elastic layer as well as constant or periodic electrical short, have potential to transfer higher energy with higher velocity. Such parameters are very important for applications of sensors. In the work, some outline of the theory, chosen qualitative aspects of such wave propagation on regular crystal surfaces as well as the results of preliminary experimental tests were presented.
Źródło:
Biuletyn Wojskowej Akademii Technicznej; 2020, 69, 4; 85-93
1234-5865
Pojawia się w:
Biuletyn Wojskowej Akademii Technicznej
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Surface Acoustic Wave Interaction with a Mixture of Oxygen and Nitrogen
Autorzy:
Pasternak, Mateusz
Jasek, Krzysztof
Grabka, Michał
Borowski, Tomasz
Powiązania:
https://bibliotekanauki.pl/articles/176628.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
surface acoustic wave sensors
oxygen detection
leaky Rayleigh waves
Opis:
Parameters of surface acoustic waves (SAW) are very sensible to change of physical conditions of a propagation medium. In the classical theory formulation, the waves are guided along the boundary of semi-infinity solid state and free space. A real situation is more complex and a medium commonly consists of two physical components: a solid substrate and a gaseous or liquid environment. In the case of stress-free substrate, the strongest impact on SAW properties have surface electrical and mechanical conditions determined by solids or liquids adhering to the boundary. This impact is utilised for constructing sensors for different gases and vapours e.g. (Jakubik et al., 2007; Hejczyk et al., 2011; Jasek et al., 2012). The influence of gaseous environment on the SAW properties is usually very weak and ignored. However, in certain condition it can be significant enough to be applied to sensor construction. In general, it concerns Rayleigh wave devices where energy leakage phenomenon is perceptible, especially when the gas being detected considerably changes the density of environment. The paper presents the results of experiments with oxygen-nitrogen mixture. Their primary aim was focused on finding the dependence of resonant frequency and attenuation in SAW resonator on parameters and concentrations of the gas in the environment.
Źródło:
Archives of Acoustics; 2020, 45, 3; 483-486
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Surface acoustic waves application for gas leakage detection
Zastosowanie akustycznych fal powierzchniowych do detekcji wycieku gazów
Autorzy:
Pasternak, Mateusz
Jasek, Krzysztof
Grabka, Michał
Powiązania:
https://bibliotekanauki.pl/articles/327742.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Polskie Towarzystwo Diagnostyki Technicznej PAN
Tematy:
surface acoustic waves
gas detection
diagnostic of sealing
akustyczne fale powierzchniowe
detekcja gazów
diagnostyka uszczelnień
Opis:
Surface Acoustic Waves (SAW) are by their nature very sensitive to changes in physical propagation conditions. This statement relates primarily to the properties of the substrate, i.e. the surface on which these waves propagate, but under certain conditions it also refers to the parameters of the gaseous environment directly in contact with the substrate. The influence of this environment on SAW parameters can be used to detect specific gases that are present in this environment and change its density. The basic research problem was to determine the dependence of the resonant frequency and attenuation of waves in a resonator with SAW on the parameters and concentrations of specific gases in the gaseous environment in which the resonator works. The secondary objective was to determine whether this dependence is strong enough to be used for the construction of sensors and whether it is possible to identify gases present in the environment based on such measurements. Two-port resonators from SAW and measuring stand of our own design were used for the research. The analyses conducted and laboratory measurements confirmed the existence of the abovedescribed dependence. It was found that it increases with the increase of the difference between the molar mass of the gas being tested and the average molecular mass of the gaseous environment. This fact makes the proposed method suitable for detection of gases of relatively low or high molar masses. In air it is possible to detect hydrogen, helium, krypton, xenon and vapour of volatile compounds with sufficiently high molar masses.
Akustyczne fale powierzchniowe (AFP) są ze swej natury bardzo czułe na zmiany fizycznych warunków propagacji. Stwierdzenie to dotyczy przede wszystkim własności ich podłoża tj. powierzchni, po której te fale się propagują, jednak w pewnych warunkach odnosi się ono także do parametrów otoczenia gazowego bezpośrednio stykającego się z tym podłożem. Wpływ tego otoczenia na parametry AFP można wykorzystać do detekcji specyficznych gazów znajdujących się w tymże otoczeniu i zmieniających jego gęstość. Podstawowym problemem badawczym było określenie zależności częstotliwości rezonansowej i tłumienia fal w rezonatorze z AFP od parametrów i stężeń określonych gazów znajdujących się w otoczeniu gazowym, w którym tenże rezonator pracuje. Ustalono też czy zależność ta jest dostatecznie silna aby dało ją się wykorzystać do budowy czujników oraz czy możliwa jest na podstawie takich pomiarów identyfikacja gazów obecnych w otoczeniu. Do badań wykorzystano dwuportowe rezonatory z AFP oraz własnej konstrukcji stanowisko pomiarowe. Stwierdzono, że wymieniona zależność rośnie w miarę wzrostu różnicy masy molowej oznaczanego gazu od przeciętnej masy cząsteczkowej otoczenia gazowego. Fakt ten powoduje, że proponowana metoda nadaje się w do detekcji gazów o stosunkowo niskich lub wysokich masach molowych. W powietrzu można w ten sposób wykrywać wodór, hel, krypton, ksenon oraz pary lotnych związków o odpowiednio wysokiej masie molowej.
Źródło:
Diagnostyka; 2020, 21, 1; 35-39
1641-6414
2449-5220
Pojawia się w:
Diagnostyka
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wave propagation in 2D between two elastic media in contact in theory of generalized two temperature thermoelasticity with gravity effect
Autorzy:
Lotfy, Khaled
Gabr, Mahmoud
El-Bary, Alaa Abd
Powiązania:
https://bibliotekanauki.pl/articles/240130.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
generalized thermoelasticity
surface waves
two temperatures
Lord-Shulman theory
influence of gravity
Opis:
The theory of generalized two-temperature thermoelasticity is used to solve the boundary value problems between two elastic media with two different types of temprature under the influence of gravity.The classical dynamical coupled theory and Lord-Şhulman theory are used to obtain the general solution of the governing equations and investigate the effect of surface waves in an isotropic elastic medium subjected to gravity field. The harmonic vibrations method is used to obtain the displacement components, stress tensor and temperature distribution in the considerd physical domain with comparison with the two theories. The obtained analytic solution of the problem is applied for special cases for which the effect of two temperatures is studied. The conductive and dynamical temperatures as well as stress and strain components are shown graphically for a suitable material. Some comparisons are also introduced in the absence and in the presence of gravity, and two-temperature parameter. The differences in the obtained results between the two theories are considered.
Źródło:
Archives of Thermodynamics; 2020, 41, 1; 219-243
1231-0956
2083-6023
Pojawia się w:
Archives of Thermodynamics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Dynamics of the FKT system with different mooring lines
Autorzy:
Wu, Jo-Ti
Chen, Jiahn-Horng
Hsin, Ching-Yeh
Chiu, Forng-Chen
Powiązania:
https://bibliotekanauki.pl/articles/258986.pdf
Data publikacji:
2019
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
ocean current energy
floating turbine system
mooring line
system dynamics
surface waves
Opis:
To harness the endless hydrokinetic energy of the Kuroshio current, the joint research team of the National Taiwan University and the National Taiwan Ocean University has developed a floating Kuroshio turbine (FKT) system in Taiwan. In normal operation, the system floats at a certain small depth from the ocean surface to reduce the wave effects and take advantage of faster current speeds. In the present study, the effect of the mooring line on the system dynamics is investigated computationally. Two different auxiliary mooring line designs and, for each design, three different common mooring lines (polyester ropes of neutral buoyancy, iron chains, and 6×19 wires ropes with wire core) are examined. The study makes use of several commercial and in-house packages, integrated to find various coefficients. It is found that the mooring line, the auxiliary mooring line design, and the gravity centre can have a significant effect on system fluctuations in normal operation if the combination of these factors is not properly matched.
Źródło:
Polish Maritime Research; 2019, 1; 20-29
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Flow-induced Vibrations of a Horizontal Elastic Band Plate Submerged in Fluid of Finite Depth
Autorzy:
Szmidt, Kazimierz
Hedzielski, Benedykt
Powiązania:
https://bibliotekanauki.pl/articles/241049.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Instytut Budownictwa Wodnego PAN
Tematy:
elastic plate vibrations
surface waves
initial value problem
coupled problem
Opis:
The paper deals with forced vibrations of a horizontal thin elastic plate submerged in a semi-infinite layer of fluid of constant depth. The pressure load on this plate is induced by water waves arriving at the plate. This load is accompanied by pressure resulting from the motion of the plate. The plate and fluid motions depend on boundary conditions, and, in particular, the pressure load depends on the width of the gap between the plate and the bottom. In theoretical description of the phenomenon, we deal with a coupled problem of hydrodynamics in which the plate and fluid motions are coupled through boundary conditions at the plate surfaces. The main attention is focused on transient solutions of the problem, which correspond to fluid (and plate) motion starting from rest. In formulation of this problem, a linear theory of small deflections of the plate is employed. In order to calculate the fluid pressure, a solution of Laplace’s equation is constructed in a doubly connected fluid domain. With respect to the initial value problem considered, we confine our attention to a finite fluid domain. For a finite elapse of time, measured from the starting point, the solution in the finite fluid area mimics a solution within an infinite domain, inherent for wave propagation problems. Because of the complicated structure of boundary conditions of the coupled problem considered, the fluid domain is divided into sub-domains of simple geometry, and the solutions of the problem equations are constructed separately in each of these domains. Numerical experiments have been conducted to illustrate the formulation developed in this paper.
Źródło:
Archives of Hydro-Engineering and Environmental Mechanics; 2019, 66, 3-4; 101-130
1231-3726
Pojawia się w:
Archives of Hydro-Engineering and Environmental Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Linear and nonlinear ΤM polarized surface waves in anisotropic metamaterials
Autorzy:
Ali, Munazza Zulfiqar
Powiązania:
https://bibliotekanauki.pl/articles/173995.pdf
Data publikacji:
2019
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
anisotropic metamaterials
surface plasmons
nonlinear waves
Opis:
The metamaterial with an effective permeability and/or permittivity tensor having elements of different magnitudes and signs is termed as the anisotropic metamaterial. The hyperbolic metamaterial may be considered as a subclass of the anisotropic metamaterial. The dispersion relation for the transverse magnetic surface waves at the interface between a nonlinear dielectric material and an anisotropic metamaterial is derived using the parallel uniaxial approximation of the permittivity tensor. This dispersion relations can be linearized by taking the nonlinear coefficient to be zero. Dispersion curves are plotted for both the linear and the nonlinear cases and are analyzed and compared in different frequency regions.
Źródło:
Optica Applicata; 2019, 49, 3; 473-486
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On propagation of Rayleigh type surface wave in five different theories of thermoelasticity
Autorzy:
Singh, B.
Verma, S.
Powiązania:
https://bibliotekanauki.pl/articles/265155.pdf
Data publikacji:
2019
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
termoelastyczność
fala powierzchniowa
fala Rayleigha
równanie częstotliwości
generalized thermoelasticity
surface waves
Rayleigh wave
frequency equation
Opis:
The governing equations for a homogeneous and isotropic thermoelastic medium are formulated in the context of coupled thermoelasticity, Lord and Shulman theory of generalized thermoelasticity with one relaxation time, Green and Lindsay theory of generalized thermoelasticity with two relaxation times, Green and Nagdhi theory of thermoelasticity without energy dissipation and Chandrasekharaiah and Tzou theory of thermoelasticity. These governing equations are solved to obtain general surface wave solutions. The particular solutions in a halfspace are obtained with the help of appropriate radiation conditions. The two types of boundaries at athe surface of a half-space are considered namely, the stress free thermally insulated boundary and stress free isothermal boundary. The particular solutions obtained in a half-space satisfy the relevant boundary conditions at the free surface of the half-space and a frequency equation for the Rayleigh wave speed is obtained for both thermally insulated and isothermal cases. The non-dimensional Rayleigh wave speed is computed for aluminium metal to observe the effects of frequency, thermal relaxation time and different theories of thermoelasticity.
Źródło:
International Journal of Applied Mechanics and Engineering; 2019, 24, 3; 661-673
1734-4492
2353-9003
Pojawia się w:
International Journal of Applied Mechanics and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wave characteristics and wave energy assessment in the Barents Sea
Autorzy:
Duan, Chenglin
Wang, Zhifeng
Dong, Sheng
Powiązania:
https://bibliotekanauki.pl/articles/2042139.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Arctic
Barents Sea
ERA-Interim
sea ice
surface waves
spatio-temporal variation
Źródło:
Polish Polar Research; 2018, 39, 1; 145-164
0138-0338
2081-8262
Pojawia się w:
Polish Polar Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Geological and seismic investigation of former lignite mining area in Zielona Góra – two case studies
Badania geologiczno–inżynierskie oraz sejsmiczne na obszarach dawnego górnictwa węgla brunatnego – dwa przypadki z terenu Zielonej Góry
Autorzy:
Gontaszewska-Piekarz, A.
Kłosiński, J.
Powiązania:
https://bibliotekanauki.pl/articles/105324.pdf
Data publikacji:
2017
Wydawca:
Politechnika Rzeszowska im. Ignacego Łukasiewicza. Oficyna Wydawnicza
Tematy:
lignite mining
Zielona Góra
seismic investigation
multichannel analysis
surface waves
MASW
seismic estimation SPT
górnictwo węgla brunatnego
badania sejsmiczne
wielokanałowa analiza fal powierzchniowych
estymacja sejsmiczna SPT
Opis:
The article presents two case studies of investigation carried out on plots of land, intended for multi-family residential development, lying on a former lignite mining area in Zielona Gora. It was underground mining, operating in the years 1840- 1948. Lignite deposits were extracted with the room and pillar method, i.e. with an overlayer collapse, causing deformations on the surface of the ground. In the first case study, there was no detailed mining data. In order to identify the geological structure under the planned seven-floor multi-family building, seismic surveys were performed with the technique of multichannel analysis of surface waves (MASW). Three seismic profiles were performed. They revealed the presence of several zones where S-waves had smaller velocity values. In order to verify whether the zones with the smaller values of velocity correspond to e.g. lower soil density resulting from collapsed exploitation room, some drillings were undertaken to the depth indicated in geophysical investigation. Additionally, the CPT and dynamic probing were also performed. The data obtained allowed to determine the soil parameters necessary for the safe design and foundation of the building. In the second case study, a historical mining map with the marked location of the shaft and the main galleries was used. Formerly, geological and engineering documentation for construction works had been prepared, based on 30-meter drillings and soundings with a heavy probe. The mining maps and the contemporary maps were mapped one on another carefully and accurately, calibrated with historic buildings. Thus, the accuracy of 5 m was obtained. Additionally, investigation with the MASW technique was performed. Ten seismic profiles were performed, and then verified by drillings. Also, dynamic probing in the vicinity of the expected location of the shaft was performed. Neither the MASW investigation nor the dynamic probing did not reveal any alterations in the soil condition, which would suggest the presence of the properly liquidated shaft. Thus, based exclusively on the cartographic material, the area comprising the liquidated and backfilled shaft was established. The area was excluded from the plans for the intended building erection.
Artykuł przedstawia badania, jakie przeprowadzono na dwóch przykładowych działkach przeznaczonych dla zabudowy wielorodzinnej leżących na terenie dawnego górnictwa węgla brunatnego w Zielonej Górze. Było to górnictwo podziemne, działające w latach 1840-1948. Węgiel 326 A. Gontaszewska-Piekarz, J. Kłosiński brunatny eksploatowany był metodą filarowo – komorową, na zawał, powodując powstawania na powierzchni deformacji terenu. Dla niektórych fragmentów miasta zachowały się mapy górnicze. W pierwszym przypadku brak było szczegółowych danych górniczych. W celu rozpoznania budowy geologicznej pod projektowany budynek wielorodzinny, 7-kondygnacyjny wykonano geofizyczne badania sejsmiczne techniką wielokanałowej analizy fal powierzchniowych MASW. Wykonano 3 profile sejsmiczne. Wykazały one kilka niewielkich stref cechujących się niższymi wartościami prędkości fal sejsmicznych poprzecznych S. W celu weryfikacji, czy strefy obniżeń prędkości związane są np. z obniżonym zagęszczeniem gruntu wskutek zawału stropu nad komorami eksploatacyjnymi wykonano odwierty do głębokości wskazanej badaniami geofizycznymi. Wykonano także sondowania sondą CPTu oraz sondowania dynamiczne. Uzyskane dane pozwoliły na określenie parametrów podłoża koniecznych do bezpiecznego zaprojektowania posadowienia budynku. W drugim przypadku dostępna była mapa górnicza z lokalizacją szybu oraz głównych chodników.
Źródło:
Czasopismo Inżynierii Lądowej, Środowiska i Architektury; 2017, 64, 2/I; 311-326
2300-5130
2300-8903
Pojawia się w:
Czasopismo Inżynierii Lądowej, Środowiska i Architektury
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mathematical modeling of torsional surface wave propagation in a non-homogeneous transverse isotropic elastic solid semi-infinite medium under a layer
Autorzy:
Sethi, M.
Sharma, A.
Vasishth, A.
Powiązania:
https://bibliotekanauki.pl/articles/265089.pdf
Data publikacji:
2017
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
non-homogeneous media
torsional surface waves
rigidity
fala powierzchniowa
propagacja fal
modelowanie matematyczne
Opis:
The present paper deals with the mathematical modeling of the propagation of torsional surface waves in a non-homogeneous transverse isotropic elastic half-space under a rigid layer. Both rigidities and density of the half-space are assumed to vary inversely linearly with depth. Separation of variable method has been used to get the analytical solutions for the dispersion equation of the torsional surface waves. Also, the effects of nonhomogeneities on the phase velocity of torsional surface waves have been shown graphically. Also, dispersion equations have been derived for some particular cases, which are in complete agreement with some classical results.
Źródło:
International Journal of Applied Mechanics and Engineering; 2017, 22, 2; 415-426
1734-4492
2353-9003
Pojawia się w:
International Journal of Applied Mechanics and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Diffraction of sound pulses on a spherical target in an oceanic waveguide covered with ice
Autorzy:
Grigorieva, N.
Kupriyanov, M.
Ostrovskiy, D.
Stepanova, D.
Powiązania:
https://bibliotekanauki.pl/articles/332177.pdf
Data publikacji:
2016
Wydawca:
Polskie Towarzystwo Akustyczne
Tematy:
diffraction of acoustic waves
ice-covered homogeneous waveguide
normal modes of the waveguide
pulse with a Gaussian envelope
surface waves
Franz type
Whispering Gallery type
Opis:
This paper is devoted to modeling of the pulse scattering by a spherical target immersed in a homogeneous waveguide covered with ice. For calculating the echo signal in the frequency domain we have followed Hackman and Sammelmann’s general approach. The arising scattering coefficients of a sphere were evaluated with the use of the normal mode method. The amount of normal modes forming the backscattered field is determined by the given directivity of the source. The emitted signal is a pulse with a Gaussian envelope. Computational results are obtained in a wide frequency range 8 - 12 kHz for water depths equal to several hundreds of m, and distances between the source/receiver and a target from 1 km up to 10 km. The target is assumed to be acoustically rigid or fluid. In particular, the properties of the ice cover and a scatterer may coincide.
Źródło:
Hydroacoustics; 2016, 19; 139-144
1642-1817
Pojawia się w:
Hydroacoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
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