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Search results for: VELOCITY OF THE PRESSURE WAVE
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Jumping Wave 2D Profiles
Open Research DataThe file contains 2D profiles obtained from a jumping wave study in front of the tool during burnishing of 1.0562 steel by the toroidal-cone tool. Burnishing speed 30.5 m/min, feed of burnishing 0.2mm/rev Force 550 and 800 N.
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Numerical FDM modelling of wave propagation in concrete structure
PublicationThe article presents application of finite difference method to damage detection and its size evaluation in concrete structure by elastic wave propagation method. The simulations of wave propagation in concrete structure were performed for six different damage scenarios. Damages were modelled as areas with changed material properties. Investigation focused on the influence of damage size on the energy of wave reflection. Presented...
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Treatment of high blood pressure in elderly and octogenarians: European Society of Hypertension statement on blood pressure targets
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Application of gamma densitometry and statistical signal analysis to gas phase velocity measurements in pipeline hydrotransport
PublicationThe work presents selected methods of signal analysis used in the processing of data obtained from radiometric probes. The used data came from an exemplary study of a two-phase liquid-gas flow at the laboratory installation. In such rigs many possible transport types may be observed, i.e. slug, plug and bubble flow, and each of them gives different signal-to-noise ratio of recorded data. Therefore, available radiometric methods...
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Application of gamma densitometry and statistical signal analysis to gas phase velocity measurements in pipeline hydrotransport
PublicationThe work presents selected methods of signal analysis used in the processing of data obtained from radiometric probes. The used data came from an exemplary study of a two-phase liquid-gas flow at the laboratory installation. In such rigs many possible transport types may be observed, i.e. slug, plug and bubble flow, and each of them gives different signal-to-noise ratio of recorded data. Therefore, available radiometric methods...
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Modelling of elastic wave propagation in a bolted joint using a thin layer of shell elements
PublicationThere are many mathematical models describing the propagation of elastic waves through the imperfect boundary of two media. They were successfully applied to modelling of high frequency bulk waves and their interaction with local defects. On the other hand, the existing literature models of bolted connections ignore the aspect of imperfect connection between elements. Therefore, this paper presents the concept of application of...
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Testing the impact of simplifications adopted in models describing wave loads on ship
PublicationThe wave-ship system in naval architecture is generally assumed to be a linear one. This allows for the computation of a transfer function of ship response to waves including wave loads on ship. The transfer function and the wave spectral density function enable the development of the stochastic process of wave loads on ship, corresponding to the irregular wave generating that loads. If the mathematical models of wave load transfer...
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Testing the impact of simplifications adopted in models describing wave loads on ship
PublicationThe wave-ship system in naval architecture is generally assumed to be a linear one. This allows for the computation of a transfer function of ship response to waves including wave loads on ship. The transfer function and the wave spectral density function enable the development of the stochastic process of wave loads on ship, corresponding to the irregular wave generating that loads. If the mathematical models of wave load transfer...
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Pressure Pulsations in Turbine Blade Seal
PublicationThe paper presents the results of experimental investigations into pressure forces generated in a turbine labyrinth seal. The experiments were performed on a single-stage air model turbine of the impulse type. The performed experimental research proved that in a shroud clearance the pressure pulsates and the effects of the nozzle trailing edge thickness as well as the influence of the rotor blades are observed. The exemplary results...
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Experimental and numerical analysis of wave propagation in ground anchors
PublicationThe article focuses on wave propagation phenomenon in ground anchors. The main aim of the investigation is the non-destructive diagnostics and the assessment of the state of ground anchors, using the guided wave propagation method. Laboratory models of anchors with different lengths of the anchor body were tested and voltage signals of propagating waves were registered at several locations. For all tested specimens corresponding...
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Measurements of electron drift velocity in OCS
PublicationWykonano pomiary prędkości dryfu elektronów w funkcji zredukowanego pola elektrycznego E/N. Wyniki tych pomiarów porównano z wynikami pomiarów w CO2 i N2O.
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Discrete measurement of fault-arc velocity
PublicationOpisano metodę dyskretnego pomiaru prędkości jednofazowego łuku awaryjnego poruszającego się w płaskim, poziomym układzie szyn. Badania przeprowadzono za pomocą punktowych czujników optycznych rozmieszczonych równomiernie wzdłuż szyn. Podano opis układu, jego charakterystykę, wpływ obszaru zjonizowanego na uzyskiwane wyniki i zależności między obserwowanymi wielkościami.
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Autonomus hydroacoustics sound velocity profiler.
PublicationPraca zawiera opis bezpośredniej zasady pomiarowej i struktury wersji autonomicznego miernika pomiarów rozkładów prędkości dźwięku w akwenach przeznaczonych do stosowania na okrętach nawodnych, podwodnych i opuszczanych antenach sonarowych śmigłowców i okrętów nawodnych.
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The integrals of velocity near the tissue in bioreactor.
PublicationWykazano, że siły tarcia występujące w trakcie hodowli decydują o jakości wzostu tkanki i jej planowanych, zamierzanych właściwościach. Siły tarcia wyznaczamy z pola prędkości cieczy biologicznej przepływającej wokół powierzchni tkanki. Dlatego w pracy tej wyznacza się pole prędkości przepływu cieczy biologicznej w cienkiej warstewce przyściennej. Wyznaczone analitycznie pole prędkości charakteryzuje się newtonowskimi właściwościami...
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Influence of velocity description on dispersivity of reactor.
PublicationPrzy projektowaniu reaktorów z reguły stosuje się model przepływu tłokowego - prosty, lecz mało dokładny. W pracy pokazano wpływ dokładności stosowanej metody opisu pola prędkości na poziom projektu reaktora.
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A Finite Element Approach for Wave Propagation in Elastic Solids
PublicationThis book focuses on wave propagation phenomena in elastic solids modelled by the use of the finite element method. Although the latter is a well-established and popular numerical tool used by engineers and researchers all around the word the process of modelling of wave propagation can still be a challenge. The book introduces a reader to the problem by presenting a historical background and offering a broad perspective on the...
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Pressure drop and heat transfer during boiling and condensation at subcritical region
PublicationMost of the data presented in the literature relate to saturation temperatures in the range - 20°C to 40°C due to the application in refrigeration technology. There is necessity to extend databases to higher values of saturation temperature due to new applications such as Organic Rankine Cycle and high temperature heat pumps. Only few papers contain data for high reduced pressure for low boiling point liquids. This paper focus...
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Measuring research on radio wave propagation
PublicationTelecommunication connections are increasingly based on the wireless links, both fixed and mobile, carried out under different radio systems. This kind of solution has many advantages. However, the propagation medium is a factor that causes many difficulties in designing wireless networks, because of large diversity of propagation environments. Transmission loss in each environment is determined by many variables phenomena and...
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Method of reconstructing two-dimensional velocity fields on the basis of temperature field values measured with a thermal imaging camera
PublicationThis paper describes a novel numerical reconstruction procedure (NRP) of the velocity field during natural convective heat transfer from a two-sided, isothermal, heated vertical plate based only on the known temperature field obtained, e.g. with a thermal imaging camera. It has been demonstrated that with a knowledge of temperature distributions, the NRP enables the reconstruction of velocity fields by solving the Navier-Stokes...
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Investigation of continuous wave jamming in an IEEE 802.15.4 network
PublicationThis paper presents how continuous wave jamming affects IEEE 802.15.4 network. To this end, an office-based measurement setup has been proposed. Within the measurement area, 25 nodes have been set up in order to create a IEEE 802.15.4 tree-based test network structure. A dedicated jamming device that generates and transmits a continuous wave signal has been developed. Several tests have been conducted and presented to demonstrate...
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Crossover from charge density wave stabilized antiferromagnetism to superconductivity in Nd1−xLaxNiC2 compounds
PublicationThe path from the charge density wave antiferromagnet NdNiC2 to the noncentrosymmetric superconductor LaNiC2 is studied by gradual replacement of Nd by La ions. The evolution of physical properties is explored by structural, magnetic, transport, magnetoresistance, and specific heat measurements. With the substitution of La for Nd, the Peierls temperature is gradually suppressed, which falls within the BCS mean-field relation for...
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Implementation of 24-hour Blood Pressure Control
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Horizontal velocity field derived from EPN and ASG-EUPOS satellite data on the example of south-western part of Poland
PublicationPresently the determination of the velocity field in the global reference frame is possible by using different space techniques and dense terrestrial networks from global to local and regional scales. However, the reliability of such determinations is strongly limited by the restricted number of unmodeled effects. Some of them are periodic (atmospheric or hydrological effects), some instantaneous (natural or man-made seismicity)...
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Importance of sign conventions on analytical solutions to the wave-induced cyclic response of a poro-elastic seabed
PublicationThis paper discusses the influence of different sign conventions for strains and stresses, i.e. the solid mechanics sign convention and the soil mechanics sign convention, on the form of governing partial differential equations (the static equilibrium equations and the continuity equation) used to describe the wave-induced cyclic response of a poro-elastic seabed due to propagation of a sinusoidal surface water-wave. Some selected...
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Microwave Ring Resonator Based Pressure Sensor
PublicationThis paper demonstrates a microwave pressure sensor, which is based on microstrip line-fed ring resonators. The first ring resonator is loaded with the concentric cylindrical shafts, while the same number of the hollow shanks as the shafts are mounted on the second ring resonator. The arrangement of the cylindrical shaft and hollow shank allows for mechanical movement between two substrates while maintaining electrical contact....
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Application of guided wave propagation in diagnostics of steel bridge components
PublicationEarly detection of potential defects and identification of their location are necessary to ensure safe, reliable and long-term use of engineering structures. Non-destructive diagnostic tests based on guided wave propagation are becoming more popular because of the possibility to inspect large areas during a single measurement with a small number of sensors. The aim of this study is the application of guided wave propagation in...
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Density, sound velocity, viscosity, and refractive index of new morpholinium ionic liquids with amino acid-based anions: Effect of temperature, alkyl chain length, and anion
PublicationIn this work, room temperature synthesis of twenty new ionic liquids (ILs) based on the N-alkyl-N-methylmorpholinium ([Mor1,R], R = 2, 3, 4, 6, 8) cation and N-acetyl-L-amino acid anions (L-alaninate, L-valinate, L-leucinate, L-isoleucinate) was described. The synthesized ILs were characterized by various spectroscopic techniques and high-resolution mass spectrometry. Furthermore, density (ρ), sound velocity (v), viscosity (η)...
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Waves Along Fractal Coastlines: From Fractal Arithmetic to Wave Equations
PublicationBeginning with addition and multiplication intrinsic to a Koch-type curve, we formulate and solve wave equation describing wave propagation along a fractal coastline. As opposed to examples known from the literature, we do not replace the fractal by the continuum in which it is embedded. This seems to be the first example of a truly intrinsic description of wave propagation along a fractal curve. The theory is relativistically...
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An Efficient PEEC-Based Method for Full-Wave Analysis of Microstrip Structures
PublicationThis article introduces an efficient method for the equivalent circuit characterization and full-wave analysis of microstrip structures, leveraging the full-wave partial element equivalent circuit (PEEC). In particular, the multilayered Green's function is evaluated using the discrete complex-image method (DCIM) and employed to establish the mixed potential integral equations. The proposed strategy considers time delays for the...
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The use of thermal imaging camera to estimate velocity profiles based on temperature distribution in a free convection boundary layer
PublicationThis work describes an attempt to assess whether the temperature field from a thermal imaging camera can be converted into a velocity field with an accuracy sufficient for qualitative conducting or describing the phenomenon, i.e. when the Navier-Stokes, Fourier-Kirchhoff and continuity equations are mutually coupled. The consequence of this link between temperature fields and velocity is the possibility to formulate the hypothesis...
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Numerical Study of Concrete Mesostructure Effect on Lamb Wave Propagation
PublicationThe article presents the results of the numerical investigation of Lamb wave propagation in concrete plates while taking into account the complex concrete mesostructure. Several concrete models with randomly distributed aggregates were generated with the use of the Monte Carlo method. The influence of aggregate ratio and particle size on dispersion curves representing Lamb wave modes was analyzed. The results obtained for heterogeneous...
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A Regional ITRF Densification by Blending Permanent and Campaign Data — The CEGRN campaigns and the Central European Velocity Field
PublicationThe CERGOP Project of the Central European Countries initiated six GPS observation campaigns from 1994 to 2001. By the high standards set within this project for site selection, observation and analysis a consistent set of epoch solutions with a precision in the 3–5 mm range was created. The network contains about 19 permanent and 38 epoch stations. In this paper a first combination solution over the seven years with a velocity...
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Selection Pressure in the Evolutionary Path Planning Problem
PublicationThis article compares an impact of using various post-selection methods on the selection pressure and the quality of the solution for the problem of planning the path for a moving object using the evolutionary method. The concept of selection pressure and different methods of post-selection are presented. Article analyses behaviour of post-selection for four options of evolutionary algorithms. Based on the results achieved, waveform...
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Simulation of Wave Propagation in Media Described by Fractional-Order Models
PublicationIn this paper, algorithms for simulation of the wave propagation in electromagnetic media described by fractional-order (FO) models (FOMs) are presented. Initially, fractional calculus and FO Maxwell's equations are introduced. The problem of the wave propagation is formulated for media described by FOMs. Then, algorithms for simulation of the non-monochromatic wave propagation are presented which employ computations in the time...
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Pressure pulsations in turbine blade seal clearance
PublicationThe paper presents the results of numerical and experimental investigations into pressure forces generated in a turbine labyrinth seal. The experiments were performed on a single-stage air model turbine of the impulse type, while the numerical results were obtained by means of CFD Fluent Code. The performed experimental research and numerical calculations prove that in a shroud clearance the pressure pulsates and the effects of...
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COMPARISON OF BLOOD PRESSURE PREDICTION METHODS
PublicationIn the paper dierent approaches of predicting blood pressure values are presented. Basically, two methods and theirs modifications are considered. In total, seven algorithms have been examined. Tests have been conducted using both synthetic and clinical data. From our study it follows that none of the examined methods is superior to other.
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IEEE Microwave and Guided Wave Letters
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Impact of the Confinement Plate on the Velocity of Synthetic Jet
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Identification in a Laboratory Tunnel to Control Fluid Velocity
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Acoustic radar employing particle velocity sensors
PublicationA concept, practical realization and applications of a passive acoustic radar to automatic localization, tracking of sound sources were presented in the paper. The device consist of the new kind of multichannel miniature sound intensity sensors and a group of digital signal processing algorithms. Contrary to active radars, it does not emit the scanning beam but after receiving surroundings sounds it provide information about the...
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Universal velocity and temperature profiles in bubbly flows.
PublicationW pracy przedstawiono model przepływu pęcherzykowego oparty na sumowaniu energii dysypacji pochodzącej od przepływu ścinającego bez pęcherzyków oraz dysypacji pochodzącej od obecności pęcherzyków. Rozwiązania równań różniczkowych opisujących model dają w wyniku uniwersalne profile prędkości i temperatur, które są bardzo przydatne w praktyce inżynierskiej.
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The Influence of Water and Mineral Oil on Pressure Losses in Hydraulic Motor
PublicationIn this paper, pressure losses in hydraulic motor supplied with water and mineral oil (two liquids that have significantly different viscosity and lubricating properties) are described and compared. The experimental tests were conducted using a hydraulic satellite motor that is dedicated to working with different liquids, including water. The methodology of measuring the pressure drop in internal channels of this motor is also...
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Damage localisation in a stiffened plate structure using a propagating wave
PublicationThe paper presents an application of changes in propagating waves for damage detection in a stiffened aluminium plate. The experimental investigation was conducted on an aluminium plate with riveted two L-shape stiffeners. The wave has been excited with a piezoelectric transducer and measured with the Laser Scanning Doppler Vibrometer. Recorded signals were analysed using the special signal processing techniques developed for damage...
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Simulations of wave propagation and attenuation in fields of colliding ice floes
Open Research DataThis dataset contains results of numerical smulations of sea ice-wave interactions, corresponding to laboratory experiments conducted at the Large Ice Model Basin (LIMB) at the Hamburg Ship Model Basin (HSVA) as part of the LS-WICE ("Loads on Structure and Waves in Ice"; https://zenodo.org/record/1067170#.XrLt_dhpxhE) project. THe simulations were conducted...
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Pressure losses and power balance in the unloaded satellite pump
PublicationThis paper presents the results of laboratory research the pressure drop in the internal channels of unloaded satellite pump pumping tap water. Also shows the characteristics of the increase of pressure in the working chamber of the pump. It has been shown that after reaching cavitation, increase pump speed will increase in torque. This is the moment of inertia caused by the increase of the operating mechanism and the liquid contained...
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PRESSURE LOSSES AND POWER BALANCE IN THE UNLOADED SATELLITE PUMP
PublicationThis paper presents the results of laboratory research the pressure drop in the internal channels of unloaded satellite pump pumping tap water. Also shows the characteristics of the increase of pressure in the working chamber of the pump. It has been shown that after reaching cavitation, increase pump speed will increase in torque. This is the moment of inertia caused by the increase of the operating mechanism and the liquid contained...
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The Global Burden of Disease Study 2015 and Blood Pressure
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General practitioners ignore high normal blood pressure
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Non-destructive inspection of ground anchors using guided wave propagation
PublicationThis paper deals with numerical and experimental investigations of specific problems of guided wave propagation in ground anchors. The research focuses on recognizing the phenomenon of the energy transfer between anchor components. Particular attention is paid to characteristic features of guided waves propagating in free and embedded parts of the tendon, at the interface between the tendon and the surrounding anchor body as well...
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Fast Full-Wave Multilevel Zero-Pole Optimization of Microwave Filters
PublicationA new concept is proposed for the full-wave computer-aided design of microwave filters. The method consists of two stages and operates on the zeros and poles of the transfer function and their derivatives. These quantities are evaluated from the response computed by a full-wave electromagnetic solver with two levels of accuracy. The two stages make use of different models that are optimized using a low-accuracy electromagnetic...