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Search results for: MIECZYSŁAW FELD
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An Analysis of Cylindrical Posts of Arbitrary Convex Cross Sections Located in Waveguide Junctions with the Use of Field Matching Method
PublicationA problem of electromagnetic wave scattering from cylindrical posts of arbitrary cross section located in waveguide junction is presented. The method of analysis is based on the direct field matching technique. Multimode scattering matrices of every section of waveguide junction are calculated and cascading procedure is utilized to investigate the whole structure. The results are verified by comparing them with those obtained from...
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Deterministic versus stochastic modelling of unsaturated flow in a sandy field soil based on dual tracer breakthrough data
PublicationThe 216 km2 Neuenhagen Millcreeck catchment can be characterized as a drought sensitive landscape in NE Germany. It is therefore a fundamental human interest to understand how water that fell as precipitation moves through the unsaturated soils and recharges groundwater. Additionally, a better knowledge of nutrient transport from soil to groundwater is important also, especially in landscapes with light sandy soils. For a better...
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Calculations of notch stress factor of a thin-walled spreader bracket fillet weld with the use of a local stress approach
PublicationPresence of geometric notches in welded joints causes concentration of strains and stresses, therefore reducing fatigue strength of such joints. This article presents an analysis of stress concentrations in a fillet weld of a spreader mounting bracket on a small sailing yacht. The aim of this article is to direct the attention of designers, manufacturers and regulatory bodies to issues of fatigue cracks that form in brackets fastening...
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Field investigation of low-temperature cracking and stiffness moduli on selected roads with conventional and high modulus asphalt concrete
PublicationHigh Modulus Asphalt Concrete (HMAC) was introduced in Poland as a one of the solutions to the problem of rutting, type of deterioration common in the 1990s. After first encouraging trials in 2002 HMAC was widely used for heavily loaded national roads and motorways. However some concerns were raised about low-temperature cracking of HMAC. This was the main reason of the studies presented in this article were started. The article...
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A fast procedure of stress state evaluation in magnetically anisotropic steels with the help of a probe with adjustable magnetizing field direction
PublicationThe paper presents a novel approach to the stress state evaluation issue. It deals with a strongly (magnetically) anisotropic materials for which a direct interpretation of the Barkhausen effect (BE) intensity would lead to erroneous results. In such a case one has to take into account both the measured BE intensity and the orientation of the magnetisation direction relative to the magnetic easy axis. For the in plane stress distribution...
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On the Nonlinea Distortions of Sound and its Coupling with Other Modes in a Gasesous Plasma with Finite Electric Conductivity in a Magnetic Field
PublicationNonlinear phenomena of the planar and quasi-planar magnetoacoustic waves are considered. We focus on deriving of equations which govern nonlinear excitation of the non-wave motions by the intense sound in initially static gaseous plasma. The plasma is treated as an ideal gas with finite electrical conductivity permeated by a magnetic field orthogonal to the trajectories of gas particles. This introduces dispersion of a flow. Magnetoacoustic...
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Initial Field Validation of Poroelastic Pavement Made with Crumb Rubber, Mineral Aggregate and Highly Polymer-Modified Bitumen
PublicationTire/road noise in most driving conditions dominates other sources of traffic noise. One of the most efficient ways of reducing tire/road noise is to use the so-called “low noise pavement”. According to numerous studies, at present, poroelastic road pavement that is composed of rubber and mineral aggregate and polyurethane or bituminous binder gives the best noise reduction up to 12 dB. Unfortunately, there are many problems with...
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Determination of Thermophysical Parameters Involved in The Numerical Model to Predict the Temperature Field of Cast-In-Place Concrete Bridge Deck
PublicationThe paper dealswith a concept of a practical computationmethod to simulate the temperature distribution in an extradosed bridge deck. The main goal of the study is to develop a feasible model of hardening of concrete consistent with in-situ measurement capabilities. The presented investigations include laboratory tests of high performance concrete, measurements of temperature evolution in the bridge deck and above all, numerical...
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An enhanced method in predicting tensile behaviour of corroded thick steel plate specimens by using random field approach
PublicationThe present work investigates the possibility of using random field techniques in modelling the mechanical behaviour of corroded thick steel plate specimens. The nonlinear Finite Element method, employing the explicit dynamic solver, is used to analyse the mechanical properties of typical specimens. A material model considering full nonlinearity is used to evaluate the stress-strain response. The influence of major governing parameters...
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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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Evaluation of pounding effects between reinforced concrete frames subjected to far-field earthquakes in terms of damage index
PublicationIn this paper, three different damage indexes were used to detect nonlinear damages in two adjacent Reinforced Concrete (RC) structures considering pounding effects. 2-, 4- and 8-story benchmark RC Moment Resisting Frames (MRFs) were selected for this purpose with 60%, 75%, and 100% of minimum separation distance and also without any in-between separation gap. These structures were analyzed using the incremental dynamic analysis...
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Development of cluster analysis methodology for identification of model rainfall hyetographs and its application at an urban precipitation field scale
PublicationDespite growing access to precipitation time series records at a high temporal scale, in hydrology, and particularly urban hydrology, engineers still design and model drainage systems using scenarios of rainfall temporal distributions predefined by means of model hyetographs. This creates the need for the availability of credible statistical methods for the development and verification of already locally applied model hyetographs....
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A finite element analysis of thermal energy inclination based on ternary hybrid nanoparticles influenced by induced magnetic field
PublicationThe use of hybrid nanoparticles to improve thermal processes is a key method that has implications for a variety of interventions utilized in many sectors. This paper aimed to look into the impacts of ternary nanoparticles on hyperbolic tangent materials to establish their thermal characteristics. Flow describing equations have been explored in the presence of heat production, non-Fourier heat flux, and an induced magnetic field....
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Factors affecting low-temperature cracking of asphalt pavements: analysis of field observations using the ordered logistic model
PublicationAccurate identification of factors that primarily affect the number of low-temperature cracks is crucial for selection of road materials and planning of pavement maintenance. Field investigations of lowtemperature cracks were performed in the years 2014 and 2020 on the same 68 road sections being in service in typical traffic conditions. The collected data were statistically analysed using the ordered logistic regression model....
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On the Application of Magnetoacoustic Emission for a Nondestructive Assessment of the Post Welding Heat Treatment of High Chromium Steel Weld Seams
PublicationThe paper analyses the possibility of post weld heat treatment (PWHT) quality assessment with the help of magnetoacoustic emission (MAE) signal measurements. Two welded superheater tubes, made of high chromium VM12 steel, were analysed—as welded and heat treated one. The analysed sample in the as welded state exhibited significantly higher hardness, accompanied by a big difference in the MAE signal intensity (of order of about...
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Full-field in vivo experimental study of the strains of a breathing human abdominal wall with intra-abdominal pressure variation
PublicationThe presented study aims to assess the mechanical behaviour of the anterior abdominal wall based on an in vivo experiment on humans. Full-field measurement of abdominal wall displacement during changes of intra-abdominal pressure is performed using a digital image correlation (DIC) system. Continuous measurement in time enables the observation of changes in the strain field during breathing. The understanding of the mechanical...
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Activated Tungsten Inert Gas Weld Characteristics of P91 Joint for Advanced Ultra Supercritical Power Plant Applications
PublicationActivated Tungsten Inert Gas (A-TIG) welding, a variant of tungsten inert gas (TIG) welding, was used for welding P91. In Generation IV power plants, P91 welds are prone to premature failure due to the presence and formation of brittle phases and creep at high temperatures. When performing A-TIG welding, the flux composition plays a role in the reversal of the Marangoni flow in the weld pool, which ultimately determines the level...
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Cascaded doubly fed induction generator for mini and micro power plants connected to grid
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Shaping the SPL Spectra of the Acoustic Noise Emitted by Inverter-Fed Indu- ction Motors
PublicationW artykule przedstawiono nowe podejście do zmniejszania wpływu właściwości mechanicznych maszyny na emitowany przez nią hałas akustyczny. Dokonano identyfikacji mechanicznych rezonansów maszyny wykorzystując modulację RPWM z losowym wyborem częstotliwości nośnej oraz modulację sigma delta, dla której otrzymano relatywnie płaskie widmo prądu. Skonstruowano na tej podstawie funkcję gęstości prawdopodobieństwa wyboru częstotliwości...
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Modelling of two-component turbulent mass and heat transfer in air-fed pressurised suits
PublicationIn this paper the modelling of an important industrial problem is addressed, which involves the two-component turbulent flow with heat transfer that takes place inside protective clothing. The geometry of the flow boundaries is reconstructed in a CAD system from photogrammetry scan data. The overall model is sufficiently realistic to allow, after validation, design improvements to be tested. Those presented here allow the reduction...
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An Analysis of Probe-Fed Rectangular Patch Antennas With Multilayer and Multipatch Configurations on Cylindrical Surfaces
PublicationA multi-patch configuration of probe-fed rectangular microstrip antennas mounted on a cylindrical body, with electrically small radius, with an arbitrary number of substrate and superstrate layers is investigated in this paper. A full-wave analysis and a moment-method calculation are employed. A unified procedure for creating proper matrices for the investigated geometry of the structure is outlined here. Numerical results for...
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Selected problems of earth fault loop impedance testing in circuits fed from UPS
PublicationIn the paper a principle of earth fault loop impedance testing in low voltage systems has been presented. Selected factors, influencing accuracy of the testing, are indicated. A structure of UPS of VFI-type and the problem of impedance testing in circuits with such type of UPS are discussed.
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Sensorless Rotor Position Estimation of Doubly-Fed Induction Generator Based on Backstepping Technique
PublicationThis paper proposes a speed observer algorithm for the sensorless control of a doubly-fed induction generator based on classical adaptive backstepping technique. The sensorless control is shown using classic stator field oriented control which is used to active and reactive power control. Performance of the proposed algorithm of a speed observer is validated by simulation and experimental results obtained using a small-rating generator...
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A Series-Inclined-Slot-Fed Circularly Polarized Antenna for 5G 28-GHz Applications
PublicationThis letter presents the design of a single-point-fed, geometrically simple circularly polarized (CP) antenna for 28 GHz Ka-band applications. The proposed antenna is based on a straight microstrip line printed on one side and coupled with the nearly square patches through a 45-degree inclined V-shape slot aperture on the other side. In order to generate circular polarization, the fundamental radiating mode is degenerated at a...
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THE EFFECTIVENESS OF PEER TUTORING IN THE FIELD OF TEACHING BASIC ASTRONOMICAL CONCEPTS AMONG OLDER PRESCHOOLERS AND YOUNGER PUPILS. A QUANTITATIVE ANALYSIS
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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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Field Cultivation and in vitro Cultures, Root-Forming Callus Cultures and Adventitious Root Cultures, of Panax quinquefolium as a Source of Ginsenosides
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Diasporic Identity in the Face of Trauma — Diasporic Identity and the Second World War Trauma in Kerri Sakamoto’s “The Electrical Field” (1998)
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Temperature-Caused Changes in Raman Pattern and Protein Profiles of Winter Triticale (x Triticosecale, Wittm.) Field-Grown Seedlings
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Three-step stacking by field-enhanced sample injection, sweeping, and micelle to solvent stacking in capillary electrophoresis: Anionic analytes
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Three-step stacking of cationic analytes by field-enhanced sample injection, sweeping, and micelle to solvent stacking in capillary electrophoresis
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Exciton quenching in emitter blends for organic light emitting devices probed by electric field-dependent time-resolved luminescence
PublicationW pracy badano mechanizm wygaszania ekscytonów w układzie dwuamina TPD:organiczny kompleks Eu:matryca TPD przez pomiar zaniku fotoluminescencji w zewnętrznym polu elektrycznym.
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Application of passive sampling technique for monitoring of BTEX concentration in urban air: Field comparison of different types of passive samplers
PublicationW efekcie przeprowadzonych badań potwierdzono przydatności techniki dozymetrii pasywnej wykorzystywanej na etapie izolacji i wzbogacania analitów do uzyskania informacji o poziomie stężeń zanieczyszczeń z grupy BTEX w powietrzu atmosferycznym na terenie aglomeracji Trójmiejskiej. Dodatkowo, porównano wyniki oznaczeń uzyskanych z wykorzystaniem dwóch typów dozymetrów pasywnych.
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The type of blood used to feed Aedes aegypti females affects their cuticular and internal free fatty acid (FFA) profiles
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Use of the UNRES force field in template-assisted prediction of protein structures and the refinement of server models: Test with CASP12 targets
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Prediction of protein structure using a knowledge-based off-lattice united-residue force field and global optimization methods
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Improved conformational space annealing method to treat β-structure with the UNRES force-field and to enhance scalability of parallel implementation
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Project management for the construction sector in the field of foundation of designed residential building located in this area with the expected impact of mining operation
PublicationAutorzy: Gwóźdź-Lasoń Monika, Berski Łukasz.
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Evaluation and comparison of random amplification of polymorphic DNA, pulsed field gel electrophoresis and ADSRRS-fingerprinting for typing Serratiamarcescens outbreaks.
PublicationADSRRS-fingerprinting, nowa metoda genotypowania oparta na supresji reakcji PCR została zastosowana do badań epidemiologicznych izolatów S. marcescens,pochodzących z trzech różnych epidemii Szpitala Publicznego w Gdańsku. Wyniki uzyskane metodą ADSRRS-fingerprinting porównano z wynikami uzyskanymi technikami RAPD-fingerprinting i PFGE.
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First detection of spectral resonance structures of the ionospheric Alfvén resonance in ULF/ELF magnetic field recorded at Suwałki, Poland
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Organic Vapor Sensing Mechanisms by Large-Area Graphene Back-Gated Field-Effect Transistors under UV Irradiation
PublicationThe gas sensing properties of graphene back-gated field-effect transistor (GFET) sensors toward acetonitrile, tetrahydrofuran, and chloroform vapors were investigated with the focus on unfolding possible gas detection mechanisms. The FET configuration of the sensor device enabled gate voltage tuning for enhanced measurements of changes in DC electrical characteristics. Electrical measurements were combined with a fluctuation-enhanced...
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Future opportunities for products derived from black soldier fly (BSF) treatment as animal feed and fertilizer - A systematic review
PublicationThe pursuit of novel food products with good nutritional value for both direct and indirect human consumption is crucial. Given the nutritional benefits of insects and the sustainability of this sort of farming, using them as food for farmed animals is a promising alternative. In this regard, the black soldier fly (Hermetia illucens) is most capable of efficiently converting a wide variety of organic materials, from food waste...
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Influence of feed rate on the granularity and homogenity of oak sawdust obtained during the sawing process on the frame sawing machine PRW15M
PublicationOpisano wpływ prędkości posuwu na skład granulometryczny i jednorodność trocin dębowych otrzymanych podczas procesu przecinania na pilarce ramowej PRW15M. Wykazano, że otrzymane trociny mogą być wykorzystane w produkcji produktów drewnopochodnych w ilości 75% dla posuwu 0.36 m/min i 82% przy posuwie 1.67 m/min. Pozostałe trociny stanowią odpad.
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Modeling the impact of discretizing rotor angular position on computation of field-oriented current components in high speed electric drives
PublicationModern drives consist of alternating current electric motors, and the field-oriented control (FOC) of such motors enables fast, precise, and robust regulation of a drive's mechanical variables such as torque, speed, and position. The control algorithm, implemented in a microprocessor, requires feedback from motor currents, and the quality of this feedback is essential to a drive's control properties. Motor phase currents are sampled...
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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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Full scale measurements of pressure field induced on the quay wall by bow thrusters – indirect method for seabed velocities monitoring
PublicationThe paper presents the results of full-scale experimental investigation of loads generated on the quay wall by bow thrusters during unberthing of a self-manoeuvring vessel. The presented research allowed for the comparison of the measurements results with generally accepted empirical prediction methods and confirmed the utility of the developed measuring setup for the on-line monitoring of jet induced loads. The conclusions from the...
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Blockchain based Secure Data Exchange between Cloud Networks and Smart Hand-held Devices for use in Smart Cities
PublicationIn relation to smart city planning and management, processing huge amounts of generated data and execution of non-lightweight cryptographic algorithms on resource constraint devices at disposal, is the primary focus of researchers today. To enable secure exchange of data between cloud networks and mobile devices, in particular smart hand held devices, this paper presents Blockchain based approach that disperses a public/free key...
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INVESTIGATIONS OF QUASI-STATIC VORTEX-STRUCTURES IN 3D SAND SPECIMENS BASED ON DEM AND HELMHOLTZ-HODGE VECTOR FIELD DECOMPOSITION.
PublicationArtykuł omawia wyniki numeryczne dotyczące struktur wirowych w materiałach granulowanych w warunkach 3D. Obliczenia wykonano dla ściskania dwuosiowego. W symulacjach wykorzystano metodę elementów dyskretnych i dekompozycję pola wektorowego wg Helmholtza-Hodge’a Struktury wirowe okazały się znakomitym prekursorem lokalizacji odkształceń stycznych w materiałach granulowanych podczas obciążenia.
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Institute of electronic systems in CARE and EuCARD projects accelerator and FEL research, development and applications in Europe
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Institute of electronic systems in CARE and EuCARD projects accelerator and FEL research, development and applications in Europe
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