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Search results for: near field measurement
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Effect of Time Varying Measurement Conditions on Antenna Pattern in Near Field Measurement and Its Correction Procedure
PublicationAuthors present the procedure of taking into account the changes of electrical parameters of setup due to the time drift of temperature during the procedure of near field measurement. It is proposed to make additional measurements in determined positions of probe are next used the results to introduce corrections terms in measured data. Such approach was verified practically in experimental near field measurement system.
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MEASUREMENT AND ANALYSIS OF ELECTRIC FIELD INTENSITY NEAR SELECTED TRANSMITTERS OF MOBILE TELEPHONY BASE STATIONS
PublicationWireless connectivity has become increasingly common in recent times. Day by day, there are more radiocommunication devices and new ideas for them. In the near future, when the fifth generation networks will be implemented, whose main feature will be continuous wireless communication, we must approach the issue of electric field measurements more and more carefully.
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Near Field Coupled Wireless Microwave Sensor
PublicationThis paper presents a wireless planar microwave sensor operating at industrial scientific and medical (ISM) frequency for the detection of dielectric materials. The microwave sensor consists of a reader (ground defected microstrip coupled line) and a passive tag where a complementary split-ring resonator (CSRR) is made on the commercially available copper-foil. The CSRR is a peel-off type tag that is excited using the near field...
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Sub-terahertz Near-field Dielectric Sensor in CMOS Technology
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CMOS-integrated near-field sensor for terahertz dielectric spectroscopy
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Quasi-analytical Near-to-Far Field Transformation Based on Field Matching Method for Scattering Problems
PublicationA new quasi-analytical near-to-far field transformation based on field matching method (field expansion in a base of Hankel functions) is presented. This approach uses finite element method to obtain near field, then the field is expressed in a base of Hankel functions. The evaluated coefficients allow to calculate the field outside the numerical domain, also in a far distance. The main advantage of the proposed technique is avoiding of...
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A system for acoustic field measurement employing cartesian robot
PublicationA system setup for measurements of acoustic field, together with the results of 3D visualisations of acoustic energy flow are presented in the paper. Spatial sampling of the field is performed by a Cartesian robot. Automatization of the measurement process is achieved with the use of a specialized control system. The method is based on measuring the sound pressure (scalar) and particle velocity (vector) quantities. The aim of the...
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Extraction of antenna pattern from near field antenna measurements distorted by undesired emission
PublicationIn this paper authors present experimental correction of antenna pattern obtained from near field measurements when they are distorted by determined electromagnetic emission. Such situation may be met e.g. when feeding or supply subsystem interacts with antenna radiation pattern due to self-emission. Presented results of experiments show effectiveness of extraction of antenna pattern utilizing near field antenna measurements.
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Air journal bearing utilizing near-field acoustic levitation: stationary shaft case
PublicationResults of a study to examine a unique idea of self-levitating journal bearing are presented in this paper. the idea represents a radical departure from the current bearing technology. it utilisesacoustic levitation, which relies on the sound energy radiated by an object supporting a load. acoustic levitation has been demonstrated to support loads of up to 10 kg. in order to support a load theacoustic wave emitted by the radiating...
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<title>Measurement and control of field in RF GUN at FLASH</title>
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Considerations about the applicability of the Reynolds equation for analyzing high-speed near field levitation phenomena
Publicationequation for analyzing near field levitation (NFL) phenomena. Two separate approaches were developed, experimentally verified, and applied to meet the research objective. One was based on the Reynolds equation and the other was based on general conservation equations for fluid flow solved using computational fluid dynamic (CFD). Comparing the calculation results revealed that, for certain operating conditions, differences in the...
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Near-Field Wireless Sensing of Plastics and Papers Using Frugal Peel-Off Passive Tag
PublicationThis article presents a novel frugal approach of testing plastics and papers using a near-field microwave sensing technique with a peel-off tag. The proposed sensing technique involves two electrical entities: the sensor, which may be regarded as a reader, and a disposable tag. The reader is a modified design of a gap-coupled microstrip line (GCML) sensor, while the passive tag is a standard double-ring complementary split-ring...
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A General Scheme of a Branch-and-Bound Approach for the Sensor Selection Problem in Near-Field Broadband Beamforming
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A CMOS-integrated terahertz near-field sensor based on an ultra-strongly coupled meta-atom
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Flow field around growing and rising vapour bubble by PIV measurement.
PublicationPrzedstawiono wyniki badania pól prędkości wokół wzrastających i unoszących się pęcherzyków parowych generowanych z pojedynczego centrum nukleacji. W badaniach zastosowano komercyjny układ Particle Image Velocimetry.
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Variations in the near-surface atmospheric electric field at high latitudes and ionospheric potential during geomagnetic perturbations
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Publisher Correction: A CMOS-integrated terahertz near-field sensor based on an ultra-strongly coupled meta-atom
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Discussion of Derivability of Local Residual Stress Level from Magnetic Stray Field Measurement
PublicationThe NDT procedure dubbed ‘metal magnetic memory’ method and the related ISO 24497 standard has found wide industrial acceptance in some countries, mainly in Russia and China. The method has been claimed by some researchers (Roskosz and Bieniek in NDT&E Int 45:55–62, 2012; Wilson et al. in Sens Actuators A 135:381–387, 2007) as having potential for quantitative determination of local residual stress state in engineering structures,...
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MOCS-based optimum design of TMD and FTMD for tall buildings under near-field earthquakes including SSI effects
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Fragility analysis of structural pounding between adjacent structures arranged in series with various alignment configurations under near‑field earthquakes
PublicationA major cause of local to total damages is related to structural pounding in a large number of past earthquakes. In general, these collisions take place as a result of differences in the dynamic characteristics of the colliding structures. To acquire a better perception of the behavior of structures, in this paper, three structures featuring different heights are modeled in series and with various configurations next to each other...
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The measurement of the velocity field around a ship hull mo-del in a tawing tank using PIV method
PublicationRozdział zawiera wyniki badań eksperymentalnych pola prędkości wokół modelukadłubu statku metodą PIV. Wykazano prawidłowość zastosowania metody PIV wtego typu badaniach.
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The influence of a strong external magnetic field from a permanent magnet on a measurement accuracy of an inductive watt-hour meter
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High gain/bandwidth off‑chip antenna loaded with metamaterial unit‑cell impedance matching circuit for sub‑terahertz near‑field electronic systems
PublicationAn innovative off-chip antenna (OCA) is presented that exhibits high gain and efficiency performance at the terahertz (THz) band and has a wide operational bandwidth. The proposed OCA is implemented on stacked silicon layers and consists of an open circuit meandering line. It is shown that by loading the antenna with an array of subwavelength circular dielectric slots and terminating it with a metamaterial unit cell, its impedance...
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System pomiaru pola magnetycznego w procesie demagnetyzacji modeli okrętów =System for magnetic field measurement in degaussing process of ships
PublicationPrzedstawiono wybrane problemy związane z budową stanowiska badawczego oraz badaniami nowych metod demagnetyzacji okrętów prowadzonych na modelach. Przedstawiono zautomatyzowany system pomiarowy do badania pola magnetycznego modelu okrętu. Omówiono strukturę i funkcje układu pomiarowego oraz metodę ograniczania błędów wynikających z przemieszczania czujników pomiarowych względem pola magnetycznego. Podano przykładowe wyniki pomiarów.
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Comparative field test for measurement of PM10 dust in atmospheric air using gravimetric (reference) method and b-absorption method (Eberline FH 62-1)
PublicationThe paper presents the results of a field test carried out in Gdansk region between 01-01-2010 and 31-12-2010 in order to demonstrate equivalence of the Eberline FH 62-1 sampler to the reference gravimetric method of suspended PM10 dust measurement. The differences in PM10 dust concentration provided by both methods have been discussed for different seasons of the year. A method of estimation of the correction factors/correction...
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Instrumental measurement of odour nuisance in city agglomeration using electronic nose
PublicationThe paper describes an operation principle of odour nuisance monitoring network in a city agglomeration. Moreover, it presents the results of investigation on ambient air quality with respect to odour obtained during six-month period. The investigation was carried out using a network comprised of six prototypes of electronic nose and Nasal Ranger field olfactometers employed as a reference method. The monitoring network consisted...
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Integrated controller for ultra high frequency technique laboratory
PublicationDepartment of Microwave and Antenna Engineering decided to modernize the laboratory of Ultra High Frequency Techniques. The main change was to replace measurement of the field distribution inside rectangular waveguides by analysing the fields around striplines. This involved the need to overcome several technical and conceptual problems. Precise positioning of the probe and reading the field distribution near the stripline is important...
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Core–shell excitation of isoxazole at the C, N, and O K-edges – an experimental NEXAFS and theoretical TD-DFT study
PublicationThe near-edge X-ray absorption fine structure (NEXAFS) spectra of the gas-phase isoxazole molecule have been measured by collecting total ion yields at the C, N, and O K-edges. The spectral structures have been interpreted using time-dependent density functional theory (TD-DFT) with the short-range corrected SRC2-BLYP exchange–correlation functional. Experimental and calculated energies of core excitations are generally in good...
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Hydrodynamic Pressure Field of a Ship on Shallow Water
PublicationResults of calculations of the hydrodynamic pressure field around the ship were obtained by application of the boundary element method. Hydrodynamic field was calculated for a Polish Navy’s tugboat and transport ship using a program called SHiPP and compared with measurements of the field taken on river near Swinoujscie for two identical tugs H-4 and H-10. Next, a series of HPF calculations was carried out on planes situated at...
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A Comparative Study on Methods of Distinction Between Near- and Far-Side Defects as Techniques Used Alongside with the Magnetic Flux Leakage Testing
PublicationResults of the finite element analysis show that a far-side defect in a steel plate, with the depth greater by 10% of the plate thickness than a near-side defect, can produce a very similar magnetic flux leakage (MFL) signal. Due to the fact that a measurement of MFL itself can lead to misclassification of a far-side defect as a near-side one, and thus to underestimation of its depth, a comparative study of three complementary...
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Environmental Role of Rime Chemistry at Selected Mountain Sites in Poland
PublicationThe results of field experiments on fog pollutantdeposition enhanced by local mountain climate, completed by thedendrochronological analysis of the forest response, are presentedin this paper. In spite of their low absolute altitude (1,000-1,600 ma.s.l), the Sudetes and the Silesian Beskid form a noticeable orographicbarrier for the airflow of the humid Atlantic air masses.This results in the increase of cloudiness and fog frequency...
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Stratification of nano-pigments in anti-corrosive coatings by means of magnetic field
PublicationThe concept of self-stratification of coatings, although attractive, causes difficulties in its practical use, especially when pigments are added to the resins. An alternative way of obtaining a multilayer structure in a single step was presented. Using the inhomogeneous magnetic field and magnetically active components of the coating, the possibility of vertically graded differentiation of the one layer properties has been verified....
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3-D Printable Metal-Dielectric Metasurface for Risley Prism-Based Beam-Steering Antennas
PublicationA 3-D printable, planar, metal-dielectric metasurface-based, 2-D beam-steering system for aperture-type antennas is presented in this paper. This beam steering system, also known as the near-field meta-steering system, comprises two fully passive phase-gradient metasurfaces placed in the antenna’s nearfield region to steer the radiation beam. To address the non-uniform electric field phase of the aperture antenna, phase correction...
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Assessing unsignalised pedestrian crossings
PublicationThe lack of pedestrian safety on crossings is a complex problem and one that is influenced by a number of factors such as the law, road traffic culture, the road and traffic. This paper will focus on the last two by presenting a method for assessing pedestrian crossings for their geometry and roadside using data from 930 pedestrian crossings in Warsaw. The authors of this paper have attempted to systematise the process of assessment...
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Static electric multipole susceptibilities of the relativistic hydrogenlike atom in the ground state: Application of the Sturmian expansion of the generalized Dirac-Coulomb Green function
PublicationThe ground state of the Dirac one-electron atom, placed in a weak, static electric field of definite $2^{L}$ polarity, is studied within the framework of the first-order perturbation theory. The Sturmian expansion of the generalized Dirac-Coulomb Green function [R. Szmytkowski, J. Phys. B: At. Mol. Opt. Phys. 30, 825 (1997); erratum R. Szmytkowski, J. Phys. B: At. Mol. Opt. Phys. 30, 2747 (1997)] is used to derive closed-form analytical...
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Eye tracking within near-to-eye display
PublicationIn this paper we investigate the effectiveness of the gaze interaction within near-to-eye display. The practical aspect of the paper is about combining an eye tracker with smart glasses. Presented research is related with the eGlasses project, which is focused on the development of an open platform in the form of multisensory electronic glasses and related interaction methods. One of the implemented interaction methods is the one...
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Influence of pulse waves on the transmission of near-infrared radiation in outer-head tissue layers.
PublicationIn this study, we investigate the effect of pulse waves on the transmission of near-infrared radiation in the outer tissue layers of the human head. This effect is important in using optical radiation to monitor brain conditions based on measuring the transmission changes in the near-infrared radiation between the source and the detector, placed on the surface of the scalp. This is because the signal related to the changes in the...
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Theory and application of Near-infrared spectroscopy
PublicationIn recent years one can observe a significant increase in the requirements on quality control in all industrial sectors. The growing number of involved analyses makes the traditional, time consuming, requiring use of large quantities of reagents, thus expansive methods inconvenient especially for industrial applications. Fortunately, there is a very fast, cheap and not invasive analytical method that is increasingly used in qualitative...
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The adaptive backstepping control of PMSM supplied by current source inverter for the field weakening region
PublicationThe sensorless control system of permanent magnet synchronous motor PMSM supplied by current source inverter for field weakening operation is presented in this paper. The adaptive backstepping control system and the backstepping speed observer are presented. The control system is based on multi-scalar variables. The control variables are: dc-link voltage and the output current vector pulsation. The control system was named voltage...
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Numerical and experimental investigation of thermal convection near electric devices with vertical channels
PublicationThis paper presents the results of numerical and experimental investigation of thermal convection near heat emitting surfaces of an electric device. For the intensification of thermal convection, special vertical channels were formed near the heat emitting surfaces of the device. An experimental test has proved that there is an optimal length of the channels – thermal convection is the most intensive then. Air velocity vectors...
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Intensification of thermal convection near electric devices using flat screens – computer modelling
PublicationIntensification of natural thermal convection near electric devices is possible by application of additional elements as screens creating convection canals close to the device. In the earlier authors paper the results of the analysis of thermal convection with the use of only one additional screen close to the electric device were presented. This paper presents computer modelling of thermal convection when two screens near the...
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MONTE CARLO MODELING OF OPTICAL SENSOR FOR POST-OPERATIVE FREE FLAP MONITORING
PublicationAfter a preliminary study of the currently employed methods in vitality monitoring of the tissue flaps (TRAM, DIEP, SIEA), a usefulness of optical techniques is discussed. It seems that one of the most promising in monitoring tissue flaps blood flow is a near infrared spectrometry (NIRS). However, a special design of a measurement sensor has to be developed. First, basing on the literature study an optical “window” is characterized....
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Vibration testing in buildings and safety of their operation
PublicationThe paper presents the issue of vibrations in residential buildings located near roads. It describes the measurement methodology and criteria for assessing the impact of vibrations generated by passing trucks. The article specifies a method to establish the impact on the operation of the examined facilities and it promotes the idea of employing a Bayesian network to determine probabilistically the level of risk to single-family...
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Numerical modeling of sound intensity distributions around acoustic transducer
PublicationThe aim of this research study is to measure, simulate and compare sound intensity distribution generated by the acoustic transducers of the loudspeaker. The comparison of the gathered data allows for validating the numerical model of the acoustic radiation. An accurate model of a sound source is necessary in mathematical modeling of the sound field distribution near the scattering obstacles. An example of such obstacle is a human...
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Static magnetic multipole susceptibilities of the relativistic hydrogenlike atom in the ground state: Application of the Sturmian expansion of the generalized Dirac-Coulomb Green function
PublicationWe study far- and near-field magnetic and electric multipole moments induced in the ground state of the Dirac one-electron atom placed in a weak 2L-pole magnetostatic field. The analysis is carried out within the framework of the first-order Rayleigh-Schrödinger perturbation theory, with the use of the Sturmian expansion of the generalized Dirac-Coulomb Green function [Szmytkowski, J. Phys. B 30, 825 (1997);J. Phys. B 30, 2747(E)...
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Failure probability of tall buildings with TMD in the presence of structural, seismic, and soil uncertainties
PublicationThe seismic performance of the tall building equipped with a tuned mass damper (TMD) considering soil-structure interaction (SSI) effects is well studied in the literature. However, these studies are performed on the nominal model of the seismic-excited structural system with SSI. Hence, the outcomes of the studies may not valid for the actual structural system. To address the study gap, the reliability theory as a useful and...
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Privacy-Preserving, Scalable Blockchain-Based Solution for Monitoring Industrial Infrastructure in the Near Real-Time
PublicationThis paper proposes an improved monitoring and measuring system dedicated to industrial infrastructure. Our model achieves security of data by incorporating cryptographical methods and near real-time access by the use of virtual tree structure over records. The currently available blockchain networks are not very well adapted to tasks related to the continuous monitoring of the parameters of industrial installations. In the database...
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Topological extraordinary optical transmission
PublicationΤhe incumbent technology for bringing light to the nanoscale, the near-field scanning optical microscope, has notoriously small throughput efficiencies of the order of 10^4-10^5 or less. We report on a broadband, topological, unidirectionally guiding structure, not requiring adiabatic tapering and, in principle, enabling near-perfect (∼100%) optical transmission through an unstructured single arbitrarily subdiffraction slit at...
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Concentration and sources of polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) in surface soil near a municipal solid waste (MSW) landfill
PublicationDue to a continuous demand of land for infrastructural and residential development there is a public concern about the condition of surface soil near municipal solid waste landfills. A total of 12 surface (0–20 cm) soil samples from a territory near a landfill were collected and the concentration of 16 PAHs and 7 PCB congeners were investigated in these samples. Limits of detection were in the range of 0.038–1.2 μg/kg for PAHs...
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Observations of presumable groundwater seepage occurrence in Puck Bay (the Baltic Sea)
PublicationWe report the results of recent field measurements of seawater thermohaline structure and transparency carried out in early summer 2014 in Puck Bay. Near-bottom, less saline waters occurred almost in the entire study area. Their occurrence in the shallow part of Puck Bay was accompanied by an increase in the seawater transparency. The most likely explanation of these observations is a submarine fresh groundwater discharge.