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Wyniki wyszukiwania dla: particle characteristics
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Possible effects of the 1984 St. Clair River ice jam on bed changes
PublikacjaThis study examines the possible effect of the record ice jam of 1984 in the St. Clair River on river bed changes and conveyance. Numerical simulations were made to examine the flow and bed shear stresses during the jam formation and release periods. Simulation results indicate that the ice jam in the river did not cause a significant increase in bed shear stress compared to pre- and post-jam open water conditions. The insignificant...
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Reconstruction of 3D structure of positive corona streamer by local methods
PublikacjaThe computer algorithms were used for reconstruction of streamer 3D structure. We propose the 3D tree structure model of corona discharge streamer composed with nodes and edges between chosen couples of nodes, which enables easy computation of some important parameters ofstreamers. The 3D model can be derived directly from two projection images by global methods like evolutionary searching or particle simulations. In this paper...
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Designing Particle Kalman Filter for Dynamic Positioning
PublikacjaThe article presents a comparative analysis of two variants of the Particle Kalman Filter designed by using two different ship motion models. The first filter bases only on the kinematic model of the ship and can be used in many types of vehicles, regardless of the vehicle dynamics model. The input value to the filter is the noisy position of the ship. The second filter makes use of the kinematic and dynamic models of the moving...
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Measuring the density of DNA films using ultraviolet-visible interferometry
PublikacjaIn order to determine a proper value for the density of dry DNA films we have used a method based upon the measurement of interference effects in transmission spectra of thin DNA layers. Our results show that the methodology is effective and the density of DNA in this state, 1.407 g/cm3, is much lower than the commonly used 1.7 g/cm3. Obtaining accurate values for the DNA film density will allow the optical constants for DNA to...
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Improved finite element method for flow, heat and solute transport of Prandtl liquid via heated plate
PublikacjaIn the current study, a vertical, 3D-heated plate is used to replicate the generation of heat energy and concentration into Prandtl liquid. We discuss how Dufour and Soret theories relate to the equations for concentration and energy. In order to see how efectively particles, interact with heat and a solvent, hybrid nanoparticles are used. It does away with the phenomena of viscous dissipation and changing magnetic felds. The motivation...
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Offshore surface waters of Antarctica are free of microplastics, as revealed by a circum-Antarctic study
PublikacjaIn 2018, during a circum navigation of Antarctica below 62° S by the sailing boat Katharsis II, the presence of plastics was investigated with surface sampling nets at ten evenly spaced locations (every 36° of longitude). Although fibres that appeared to be plastic (particles up to 2 cm) were found in numbers ranging from 1 particle (0.002 particles per m3) to 171 particles (1.366 particles per m3) per station, a Fourier-transform...
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A general approach to study molecular fragmentation and energy redistribution after an ionizing event
PublikacjaWe propose to combine quantum chemical calculations, statistical mechanical methods, and photoionization and particle collision experiments to unravel the redistribution of internal energy of the furan cation and its dissociation pathways. This approach successfully reproduces the relative intensity of the different fragments as a function of the internal energy of the system in photoelectron–photoion coincidence experiments and...
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The effect of full-cell impregnation of pine wood (Pinus Sylvestris L.) on the fine dust content during sawing on a frame sawing machine
PublikacjaIn this paper the results of the analysis of the effect of the impregnation treatment of pine wood on the granularity of sawdust from the sawing process on the frame sawing machine PRW 15M are presented. Granulometric analyses of chips from impregnated and unimpregnated pine wood implies that the impregnation of pine wood does not affect the size and structure of the sawdust produced. A major ≈ 95% share of the formed chips is...
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Pseudo-superparamagnetic behaviour of bariumhexaferrite particles
PublikacjaThe effect of hexadecyltrimethylammonium bromide (CTAB) addition on the crystal structure, morphology,and magnetic properties of co-precipitated hexagonal barium ferrite was investigated. For afixed amount ofsurfactant, different Fe3+concentrations and Fe3+/Ba2+ratios were used to optimize the formation ofsingle-phase barium ferrite particles. The results indicated that the obtained ferrite particles exhibitedcoercivity changes...
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LCT, PIV and IR Imaging Detection in Selected Technical and Biomedical Applications
PublikacjaThermochromic liquid crystals (TLC), Particle Image Velocimetry (PIV) and Infrared Imaging Themography (IR) have been successfully used in non-intrusive technical, industrial and biomedical studies and applications. These four tools (based on the desktop computers) have come together during the past two decades to produce a powerful advanced experimental technique as a judgment of quality of information that cannot be obtained...
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Influence of sludge treatment processes on heavy metal speciation
PublikacjaSludge composition is depending on sewage quality and also affected by processing methods such as thickening, stabilization and dewatering. During those processes some of sludge's undesirable properties might be reduced or enhanced.The objective of the study is the assessment of the influence of sludge processing on selected heavy metals partitioning between phases (aqueous and particle) and sludge. Sludge from the WWTP in Gdansk...
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Influence of nitrogen and organic matter fractions on wastewater treatment in treatment wetland
PublikacjaMunicipal wastewater contains both biodegradable and non-degradable pollutants. Moreover, they are present in dissolved, colloidal and particulate forms. These fractions are characterised by various decomposition rates, hence their bioavailability during microbial respiration. It was confirm that biological degradation rate in terms of COD reduction is influenced by particle size speciation. Therefore, the objective of the study...
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Particle Shape Effect on Macroscopic Behaviour of Underground Structures: Numerical and Experimental Study
PublikacjaAbstract: The mechanical performance of underground flexible structures such as buried pipes or culverts made of plastics depend not only on the properties of the structure, but also on the material surrounding it. Flexible drains can deflect by 30% with the joints staying tight, or even invert. Large deformations of the structure are difficult to model in the framework of Finite Element Method, but straightforward in Discrete...
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Pumping effect measured by PIV method in a multilayer spike electrode EHD device for air cleaning
PublikacjaDust particles can be harmful for human health when inhaled. Particularly dangerous are submicrometer dust particles, which can contain traces of toxic elements and can easily penetrate into the human respiratory system. Thus, efficient devices for the air cleaning from submicrometer dust particles are needed. Recently, Katatani and Mizuno have proposed an electrohydrody- namic (EHD) device for air cleaning for submicrometer particles....
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COMPARISON OF TWO MODELS OF CONDENSATION
PublikacjaIn the low-pressure part of steam turbine, the state path usually crosses the saturation line in penultimate stages. At least last two stages of this part of turbines operate in two –phase region. The liquid phase in this region in mainly created in the process of homogeneous and heterogeneous condensation. Several observations confirm however, that condensation often occurs earlier than it is predicted by theory i.e. before the...
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Spectral measurement of birefringence using particle swarm optimization analysis
PublikacjaThe measurement of birefringence is useful for the examination of both technical and biological objects. One of the main problems is that the polarization state of light in birefringent media changes periodically. Without the knowledge of the period number, the birefringence of a given medium cannot be determined reliably. We propose to analyse the spectrum of light in order to determine the birefringence. We use a Particle Swarm...
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The Progress in Electron Microscopy Studies of Particulate Matters to Be Used as a Standard Monitoring Method for Air Dust Pollution
PublikacjaThe present article reviews studies on air solid particles carried out with the use of electron microscopy. Particle analysis combining scanning and transmission electron microscopy (SEM and TEM) can be used to derive size-resolved information of the composition, mixing state, morphology, and complex refractive index of atmospheric aerosol particles. It seems that electron microscopy is more widely used in atmospheric particulate...
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A system for acoustic field measurement employing cartesian robot
PublikacjaA 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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Particle Shape Effect on Macroscopic Behaviour of Underground Structures: Numerical and Experimental Study
PublikacjaThe mechanical performance of underground flexible structures such as buried pipes or culverts made of plastics depend not only on the properties of the structure, but also the material surrounding it. Flexible drains can deflect by 30% with the joints staying tight, or even invert. Large deformations of the structure are difficult to model in the framework of Finite Element Method, but straightforward in Discrete Element Methods....
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SPECTRAL-BASED MODAL PARAMETERS IDENTIFICATION WITH MULTIPLE PARTICLE SWARMS OPTIMIZATION
PublikacjaThe paper presents usage of a Particle Swarm Optimization [1] based algorithm for spectral-based modal parameters identification. The main algorithm consists of two groups of swarms, namely, scouts and helpers. For the first group additional penalizing process is provided to force separation of scouting swarms in frequency space. The swarms have an ability to communicate with each other. At first stage, each swarm focuses on a...
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Liquid Crystals, PIV and IR-Photography in Selected Technical and Biomedical Applications
PublikacjaThermochromic liquid crystals (TLC), Particle Image Velocimetry (PIV), Infrared Imaging Themography (IR) and True-Colour Digital Image Processing (TDIP) have been successfully used in non-intrusive technical, industrial and biomedical studies and applications. These four tools (based on the desktop computers) have come together during the past two decades to produce a powerful advanced...
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The role of low-energy electrons in the charging process of LISA test masses
PublikacjaThe estimate of the total electron yield is fundamental for our understanding of the test-mass charging associated with cosmic rays in the Laser Interferometer Space Antenna (LISA) Pathfinder mission and in the forthcoming gravitational wave observatory LISA. To unveil the role of low energy electrons in this process owing to galactic and solar energetic particle events, in this work we study the interaction of keV and sub-keV...
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Exfoliated graphite with spinel oxide as an effective hybrid electrocatalyst for water splitting
PublikacjaThe aim of the conducted research was to develop hybrid nanostructures formed from MnCo2O4 and exfoliated graphite. Carbon added during the synthesis allowed for obtaining a well-distributed MnCo2O4 particle size with exposed active sites contributing to the increased electric conductivity. The influence of the weight ratios of carbon to a catalyst for hydrogen and oxygen evolution reactions was investigated. The new bifunctional...
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The use of liquid crystal thermography TLC and particle image velocimetry PIV in selected technical applications
PublikacjaNowadays, the energy cost is very high and this problem is carried out to seek techniques for improvement of the aerothermal and thermal (heat flow) systems performances in different technical applications. The transient and steady-state techniques with liquid crystals for the surface temperature and heat transfer coefficient or Nusselt number distribution measurements have been developed. The flow pattern produced by transverse...
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Program komputerowy do odtwarzania kształtu osi toru kolejowego
PublikacjaW pracy przedstawiono metodę odtwarzania kształtu osi toru kolejowego w płaszczyźnie poziomej na podstawie ciągłych pomiarów satelitarnych. W metodzie tej został wykorzystany algorytm projektowania odcinków trasy kolejowej położonych w łuku, w którym zastosowano analityczną formę opisu za pomocą odpowiednich formuł matematycznych. Procedura projektowania ma charakter uniwersalny − stwarza możliwość zróżnicowania rodzaju i długości...
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Energy deposition on the inner surface of a Hall Effect thruster for satellite
PublikacjaHET - Hall Effect Thruster, to silnik powszechnie wykorzystywany w kosmonautyce do pozycjonowania satelitów. Medium dostarczającym ciąg silnikowi jest zjonizowany gaz. Praca przedstawia wyniki trzech symulacji komputerowych: 1. Modelowanie sondy Langmuira zanurzonej w plazmie ksenonowej o warunkach zbliżonych do tych panujących w silniku HET. Symulacje wykonano metodą metodą Particle-in-Cell Monte Carlo. Celem była analiza oddziaływania...
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An analysis of solar energy conversion systems based on photon and thermal processes
PublikacjaSolar spectral irradiance covers a fairly broad wavelength range. Solar radiation is part of the electromagnetic spectrum which is described by the concept of wave-particle duality. The corpuscular theory of electromagnetic radiation states that energy is transmitted by photons. Photons carry specific amounts of energy which can be used to convert solar energy into other types of energy, in particular electricity. The internal...
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Technique for reducing erosion in large-scale circulating fluidized bed units
PublikacjaThis paper presents a methodology, implemented for a real industrial-scale circulating fluidized bed boiler, to mitigate the risk of heating surfaces exposed to an intensive particle erosion process. For this purpose, a machine learning algorithm was developed to support the boiler reliability management process. Having a tool that can help mitigate the risk of uncontrolled power unit failure without expensive and technically complex...
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Two-dimensional simulations of concrete fracture at aggregate level with cohesive elements based on X-ray lCT images
PublikacjaThe paper presents results of two-dimensional meso-scale simulations of fracture in notched concrete beams subjected to three-point bending test. Concrete was assumed as a 4-phase material composed of aggregate grains placed in the cement matrix, interfacial transitional zones (ITZs) and macro-voids. The particle distribution was taken from real concrete beams on the basis of X-ray lCT images. Comprehensive numerical analyses were carried...
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Evolution of electrohydrodynamic flow of sduspended particles in a needle-to-plate negative DC corona discharge in air
PublikacjaCorona discharges are used for collecting dust in electrostatic precipitators (ESPs). The dust collection is mainlyrealized by the electric forces which move the ionized dust particles to the collecting electrodes. However, the presence of coronadischarge in the space between the charging and collecting electrodes in ESPs causes also the so-called ionic wind which set the gasmolecules and dust...
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Highly crystalline colloidal nickel oxide hole transport layer for low-temperature processable perovskite solar cell
PublikacjaHighly crystalline NiOX usually requires high annealing temperature (>300 °C) which is incompatible with flexible substrate and might consume high amount of energy. Herein, we demonstrate a facile emulsion process to synthesize highly crystalline, low temperature deposition (<150 °C) and solution processable NiOx nanoparticles (NPs) as a hole transport layer for the perovskite solar cells (PVSCs)....
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TIME-AND-SPACE STRUCTURE OF FORCE-DRIVEN RIGID SPHEREWAVEFIELD
PublikacjaThis paper introduces a time-domain, causality-inspired description of a vector-source acoustic wavefield of arbitrary time evolution, where a sphere is a practical realisation of quasi-point contact surface without which a point force would not be able to exert an impact onto non-viscous fluid. At every space location, the resulting acoustic field is described by a pair of physical variables characterising the time evolution of...
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Functionalization of indium-tin-oxide electrodes by laser-nanostructured gold thin films for biosensing applications
Publikacjaof a relatively large area formed by pulsed laser nanostructuring of thin gold films arereported and discussed. The SEM inspection of modified electrodes reveals the presence of the nearlyspherical and disc-shaped particles of dimensions in the range of 40–120 nm. The NP-array geometry canbe controlled by selection of the laser processing conditions. It is shown that particle size and packingdensity of the array are important factors...
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Investigation of Narrow Electrostatic Precipitator with Wire Multi-Electrode
PublikacjaDiesel engines emit fine particles, which are harmful to human and animal health. There are several methods for decrease particulate emission from a diesel engines, but up to now, these methods are notenough effective or very expensive. An electrostatic precipitation was proposed as an alternative method for control of a diesel particulate emission. Therefore, narrow electrostatic precipitators (ESPs) have become a subject of interest...
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Theoretical investigation of the structural insights of the interactions of γ-Fe2O3 nanoparticle with (EMIM TFSI) ionic liquid
PublikacjaOne of the possible applications of ionic liquids is to produce electricity from heat. The iron oxide nanoparticle is a potent electrical particle, which is expected to improve the heat’s efficiency to electricity conversion, however, it is prone to aggregation and sedimentation, which hamper its application. One of the methods to enhance the nanoparticle’s solubility and electrical properties is the use of a stabilizing component...
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Tribological Properties of Ni-P/Si3N4 Nanocomposite Layers Deposited by Chemical Reduction Method on Aluminum Alloy AW-7075
PublikacjaThe article presents the results of tribological tests of Ni-P/Si3N4 nanocomposite and Ni-P nickel layers deposited on the AW-7075 aluminum alloy by chemical reduction method, and the AW-7075 alloy without coating. Nanocomposite layers were produced using Si3N4 siliconnitride in the form of a polydisperse powder whose particle sizes ranged from 20 to 25 nm. The influence of the content of the dispersion phase layer material on...
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Manufacturing of Lightweight Aggregates as an Auspicious Method of Sewage Sludge Utilization
Publikacja: Sewage sludge is a high-volume and low-cost waste commonly generated worldwide, so its utilization is a vital issue. The application of this waste in the manufacturing of lightweight aggregates was investigated. The process was performed using intensive mixers with volumes of 5 and 30 L, as well as the industrial 500 L mixer. Then, granulates were sintered in a tube furnace. The influence of composition and mixer size on the...
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Optical flow method for measuring deformation of soil specimen subjected to torsional shearing
PublikacjaIn this study optical flow method was used for soil small deformation measurement in laboratory tests. The main objective was to observe how the deformation distributes along the whole height of cylindrical soil specimen subjected to torsional shearing (TS test). The experiments were conducted on dry non-cohesive soil specimens under two values of isotropic pressure. Specimens were loaded with low-amplitude cyclic torque to analyze...
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Comment on "Measurements without probabilities in the final state proposal"
PublikacjaThe final state proposal [G.T. Horowitz and J.M. Maldacena, J. High Energy Phys.2004(2),8 (2004)] is an attempt to relax the apparent tension betweenstring theory and semiclassicalarguments regarding the unitarity of black hole evaporation. The authors of [R. Bousso and D.Stanford, Phys. Rev. D89, 044038 (2014)] analyze thought experiments where an infalling observerfirst verifies the entanglement between early and late Hawking...
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Application of the Optimization Methods to the Search of Marine Propulsion Shafting Global Equilibrium in Running Condition
PublikacjaFull film hydrodynamic lubrication of marine propulsion shafting journal bearings in running condition is discussed. Considerable computational difficulties in non-linear determining the quasi-static equilibrium of the shafting are highlighted. The approach using two optimization methods (the particle swarm method and the interior point method) in combination with the specially developed relaxation technique is proposed to overcome...
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Morphology, surface properties and photocatalytic activity of the bismuth oxyhalides semiconductors prepared by ionic liquid assisted solvothermal method
PublikacjaThis is the first report of the effect of the ILs cation type (imidazolium, pyridinium and pyrrolidinium) on the morphology, surface properties and photoactivity of BiOX semiconductors type obtained by solvothermal method in glycerol. The various ionic liquids (IL) cation type as a halogen source and templating agent for the synthesis of the bismuth oxyhalides nanoparticles has been systematically investigated. The role of ILs...
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Estimation of structural stiffness with the use of Particle Swarm Optimization
PublikacjaThe paper presents the theoretical background and four applications examples of the new method for the estimation of support stiffness coefficients of complex structures modelled discretely (e.g. with the use of the Finite Element Model (FEM) method based on the modified Particle Swarm Optimization (PSO) algorithm. In real-life cases, exact values of the supports’ stiffness coefficients may change for various reasons...
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Effect of sintering temperature on electrochemical performance of porous SrTi1-xFexO3-δ (x = 0.35, 0.5, 0.7) oxygen electrodes for solid oxide cells
PublikacjaThis work evaluates the effects of the sintering temperature (800 °C, 900 °C, 1000 °C) of SrTi1-xFexO3-δ (x = 0.35, 0.5, 0.7) porous electrodes on their electrochemical performance as potential oxygen electrode materials of solid oxide cells. The materials were prepared by a solid-state reaction method and revealed the expected cubic perovskite structure. After milling, the powders were characterised by a sub-micrometre particle...
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Optimal Placement of Phasor Measurement Unit in Power System using Meta-Heuristic Algorithms
PublikacjaThe phasor measurement units (PMUs) play an important and vital role in power system monitoring and controlling, since they provide the power system phasors stamped with a common real time reference through a global positioning system (GPS). Indeed, from economical point of view it is not possible to set PMUs in all system buses due to the high cost and the requirement of more complex communication...
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Analysis of abrasive particle trajectories during single-sided lapping process with driven conditioning ring
PublikacjaIn this paper new kinematics systems were studied for a single lapping process. In order to ensure the constant profile wear of the tool a standard kinematic system can be changed. Lapping is carried out by applying loose abrasive grains between two surfaces and causes a relative motion between them. The result is a finish of multi-directional lay. During process, the mechanism of surface formation are decisively affected by a...
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ANALIZA NIELINIOWEGO OBSERWATORA I FILTRU CZĄSTECZKOWEGO JAKO ESTYMATORÓW POZYCJI STATKU.
PublikacjaW artykule została przedstawiona analiza porównawcza dokonana pomiędzy dwoma estymatorami pozycji. Analiza ta została przedstawiona na podstawie różnicy pomiędzy wartością estymowaną a rzeczywistą. Badania estymatorów zostały przeprowadzone na podstawie równania kinematyki i dynamiki statku dynamicznie pozycjonowanego. Wartościami wykorzystywanymi w symulacji są pomiary z symulowanego odbiornika GPS i siły wytworzone przez napędy...
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Computer-aided reconstruction of the railway track axis geometrical shape
PublikacjaIn the paper a method of the railway track axis geometrical shape identification in a horizontal plane, directly from the continuous satellite measurements, is presented. In this method, an algorithm for the design of railway track sections located in the horizontal arc is used. The algorithm uses an analytical description of the layout by means of suitable mathematical formulas. The design procedure has a universal character and...
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Turbulence model evaluation for numerical modelling of turbulent flow and heat transfer of nanofluids
PublikacjaIn this work, Nusselt number and friction factor are calculated numerically for turbulent pipe flow (Reynolds number between 6000 and 12000) with constant heat flux boundary condition using nanofluids. The nanofluid is modelled with the single-phase approach and the simulation results are compared with experimental data. Ethylene glycol and water, 60:40 EG/W mass ratio, as base fluid and SiO2 nanoparticles are used as nanofluid...
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Porosity and swelling properties of novel polyurethane–ascorbic acid scaffolds prepared by different procedures for potential use in bone tissue engineering
PublikacjaIn this work, a novel polyurethane (PU) system based on poly(ethylene-butylene) adipate diol, 1,6-hexamethylene diisocyanate, 1,4-butanediol, and ascorbic acid was used to prepare scaffolds with potential applications in bone tissue engineering. Two fabrication methods to obtain porous materials were chosen: phase separation (PS)/salt particle leaching (PL) and solvent casting (SC)/salt PL. The calculated porosity demonstrated...
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Swarm-Assisted Investment Planning of a Bioethanol Plant
PublikacjaBioethanol is a liquid fuel for which a significant increase in the share of energy sources has been observed in the economies of many countries. The most significant factor in popularizing bioethanol is the profitability of investments in construction of facilities producing this energy source, as well as the profitability of its supply chain. With the market filled with a large amount of equipment used in the bioethanol production...