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Electrical mapping of AISI 304 stainless steel subjected to intergranular corrosion performed by means of AFM-LIS in the contact mode
PublicationThe paper presents results of the AFM-based approach to local impedance spectroscopy (LIS) measurements performed in a 20 20 lm grid within an austenite grain–grain boundary region for sensitized AISI 304 stainless steel (SS). Maps of electrical parameters obtained on the basis of localized impedance spectra were demonstrated, presenting their changes and correlation with the sample topography. Performed research revealed significant...
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SZACOWANIE ZAWARTOŚCI BENZO(a)PIRENU W PYLE ZAWIESZONYM PM10 W AGLOMERACJI TRÓJMIEJSKIEJ ZA POMOCĄ WIELOWYMIAROWEJ REGRESJI LINIOWEJ=ESTIMATION OF BENZO(A)PYRENE CONTENT IN SUSPENDED DUST PM10 IN TRI-CITY AGGLOMERATION USING MULTIDIMENSIONAL LINEAR REGRESSION
PublicationW pracy przedstawiono próbę oszacowania przy pomocy wielowymiarowej regresji liniowej modelu empirycznego opisującego czynniki wpływające na zawartość B(a)P w pyle zawieszonym PM10 w Aglomeracji Trójmiejskiej w latach 2008-2011. Na przestrzeni tych lat średnioroczne stężenie B(a)P w PM10 wzrosło ponad dwukrotnie i ponad trzykrotnie przewyższa poziom docelowy. Z przeprowadzonych analiz wynika, że główną przyczyną wzrostu stężenia...
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Visible-light-driven lanthanide-organic-frameworks modified TiO2 photocatalysts utilizing up-conversion effect
PublicationHighly efficient and quite stable composite with core-shell-like architecture reported herein, responds to the challenge of sunlight-driven photocatalysts. The Ln(ndc)/TiO2 photocatalytic system comprises active lanthanide-carboxylate coordination networks (Nd, Er, Ho, and Tm as metal ions, and 2,6-naphthalene dicar-boxylic acid as the organic linker) and inert titanium dioxide and allow to convert incompatible visible radiation...
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High catalytic performance of laccase wired to naphthylated multiwall carbon nanotubes
PublicationThe direct electrical connection of laccase on the electrode surface is a key feature in the design of efficient and stable biocathodes. However, laccases can perform a direct electron transfer only when they are in the preferable orientation toward the electrode. Here we report the investigation of the orientation of Laccase from Amano on multi-walled carbon nanotube surface modified with naphthalene group. Naphthylated multi...
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Polymodal Method of Improving the Quality of Photogrammetric Images and Models
PublicationPhotogrammetry using unmanned aerial vehicles has become very popular and is already commonly used. The most frequent photogrammetry products are an orthoimage, digital terrain model and a 3D object model. When executing measurement flights, it may happen that there are unsuitable lighting conditions, and the flight itself is fast and not very stable. As a result, noise and blur appear on the images, and the images themselves can...
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Maximum Power Point Technique (MPPT) for PV System Based on Improved Pert and Observe (P&O) Method with PI Controller
PublicationPhotovoltaic power generation system has key rule in electricity production. Although, it is clean renewable energy with unlimited resources but it has some drawbacks in efficiency. In order to maximize the efficiency, PV array must drive at maximum power point. For the reason so, several algorithms are used in PV system to track MPP and reduce the...
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Molecular dynamics simulations of the affinity of chitin and chitosan for collagen: the effect of pH and the presence of sodium and calcium cations
PublicationChitosan and chitin are promising biopolymers used in many areas including biomedical applications, such as tissue engineering and viscosupplementation. Chitosan shares similar properties with hyaluronan, a natural component of synovial fluid, making it a good candidate for joint disease treatment. The structural and energetic consequences of intermolecular interactions are crucial for understanding the biolubrication phenomenon...
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Enhanced photoelectrochemical performance of inorganic-organic hybrid consisting of BiVO4 and PEDOT:PSS
PublicationThe PEDOT:PSS (poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)) was electrodeposited on a thin layer of bismuth vanadate (BiVO 4 ) prepared using the pulsed laser deposition technique onto FTO. The inorganic-organic junction was characterized by Raman spectroscopy, UV-Vis spectroscopy and sc anning electron microscopy. Chronoamperometry curves, recorded under simulated solar light illumination,...
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Configurations of H 3 + (H2)n clusters and their energies
PublicationThe H-3(+) ion plays an important role in low temperature astrophysical and laboratory plasmas. It is considered as the initiator of many ion-molecule chemistries. Also its clusters with H-2 are quite interesting. We study configurations of the H-3(+)(H-2)(n) clusters for n = 1 up to n = 12 as a simple test system. Total energies for these structures, with zero point vibration corrections have been calculated. Stabilization energies...
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Synthesis of 5-Substituted 1H-Tetrazoles from Nitriles in the Presence of Heterogeneous Catalyst
PublicationTetrazoles are five-membered heterocyclic compounds containing in their rings four nitrogen atoms. They have wide applications as corrosion inhibitors, analytical reagents, high-energy materials and gas generating compositions. Tetrazoles also play important role in coordination chemistry as ligands and in medicinal chemistry as metabolically stable surrogates for carboxylic acids. In recent years, investigation of new method of...
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Energetics of formation and stability in high pressure steam of barium lanthanide cobaltite double perovskites
PublicationThis study concerns energetics of formation and the stability in high water partial pressure of BaLnCo2O6−δ, (Ln = La, Pr, Nd, and Gd) (BLnC) and BaGd1−xLaxCo2O6−δ, where x = 0.2, 0.5, and 0.7 (BGLC) double perovskite cobaltites. Those materials are extensively studied due to their potential applications as a positrode in electrochemical devices. Therefore, their stability under such conditions is a key issue. All investigated...
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Sea spray as a secondary source of chlorinated persistent organic pollutants? - Conclusions from a comparison of seven fresh snowfall events in 2019 and 2021
PublicationSecondary sources of persistent organic pollutants (POPs) gain in importance worldwide as primary sources decline. In this work, we aim to determine whether sea spray may be a secondary source of chlorinated POPs to the terrestrial Arctic, since a similar mechanism was proposed there only for the more water-soluble POPs. To this end, we have determined polychlorinated biphenyls and organochlorine pesticides concentrations in fresh...
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Mechanical Properties of 3D Printed Parts and Their Injection Molded Alternatives Subjected to Environmental Aging
PublicationAdditive manufacturing is the technology used in medical, industrial, or lifestyle applications. The scientific literature include works reporting various manufacturing parameters’ influence on changes in additive manufacturing components’ mechanical behavior, especially with fused filament fabrication (FFF). The changes in mechanical strength and toughness of FFF compared to injection molding parts were studied. In the study,...
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Development and validation of an eco-compatible UV–Vis spectrophotometric method for the determination of Cu2+ in aqueous matrices
PublicationCu 2+ are ubiquitous ions in the ecosystem and are responsible of serious environmental pollution. Indeed, the development of sensitive methods for Cu 2+ detection is an urgent demand. In this work, we proposed a new spectrophotometric method for Cu 2+ determination in different water matrices (distilled water, drinking water, wastewater, and river water). The method employs a bio-based organic ligand namely tetrasodium iminodisuccinate...
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Applying molecular dynamics simulation to take the fracture fingerprint of polycrystalline SiC nanosheets
PublicationGraphene-like nanosheets are the key elements of advanced materials and systems. The mechanical behavior of the structurally perfect 2D nanostructures is well documented, but that of polycrystalline ones is less understood. Herein, we applied molecular dynamics simulation (MDS) to take the fracture fingerprint of polycrystalline SiC nanosheets (PSiCNS), where monocrystalline SiC nanosheets (MSiCNS) was the reference nanosheet....
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Failure analysis of a high-speed induction machine driven by a SiC-inverter and operating on a common shaft with a high-speed generator
PublicationDue to ongoing research work, a prototype test rig for testing high-speed motors/generators has been developed. Its design is quite unique as the two high- speed machines share a single shaft with no support bearings between them. A very high maximum operating speed, up to 80,000 rpm, was required. Because of the need to minimise vibration during operation at very high rotational speeds, rolling bearings were used. To eliminate...
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Resilience of 5G Mobile Communication Systems to Massive Disruptions
PublicationThis chapter discusses vital techniques to enhance the resilience of 5G systems. It starts with dependability assessment of 5G networks. Next, it describes (a) the frequency fallback technique to improve availability and survivability of 5G services, (b) segment interleaving scheme to enhance communications resilience between base stations and the remaining part of the network and (c) multi-operator protection to address the resilience...
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Participatory approach to urban regeneration processes in polish cities and regions
PublicationThe paper presents the impact of EU Cohesion Policy 2014-2020 on regeneration processes which are implemented in Polish towns, cities and metropolis when emphasizing general formal and legal framework including examination of the possible distribution of EU funds for regeneration projects within the regional operational programmes. The paper focuses on different approaches to the implementation of Cohesion Policy in Polish regions....
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THE EFFECT OF WOOD DRYING METHOD ON THE GRANULARITY OF SAWDUST OBTAINED DURING THE SAWING PROCESS USING THE FRAME SAWING MACHINE
PublicationThe experimental results of the study focused on the effect of drying processes of warm air drying at the temperature of 6580°C and warm air-steam mixture drying at the temperature of 105°C of pine and beech wood to the size of sawdust grains created by cutting using RPW 15M frame saw is presented in the paper. Particle size analysis of dry sawdust was performed using two methods - screening method and optical method based on...
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Dynamic mechanical properties and flexing fatigue resistance of tire sidewall rubber as function of waste tire rubber reclaiming degree
PublicationA stepwise downsizing method of gel particles in reclaimed rubber to a micro-nano scale and its excellent dynamic performance in tire sidewall were introduced by this work. The results showed that the size of gel particles decreased from several micrometers to micro-nanometers with the increase of reclaiming degree, accompanied by reduced molecular weight and widened molecular weight distribution of sol fraction. The addition of...
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A comparative performance assessment of a hydrodynamic journal bearing lubricated with oil and magnetorheological fluid
PublicationThis work presents the investigation results of a journal bearing lubricated with magnetorheological fluid that is activated by a local constant magnetic field to vary both the local flow resistance and pressure. The bearing performance is assessed via Finite Element Modelling (FEM) and results are corroborated by experiments. The FEM model uses the Bingham model to describe the fluid film. A dedicated test rig is used to assess...
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The Use of Cluster Analysis to Evaluate the Impact of COVID-19 Pandemic on Daily Water Demand Patterns
PublicationProper determination of unitary water demand and diurnal distribution of water consumption (water consumption histogram) provides the basis for designing, dimensioning, and all analyses of water supply networks. It is important in the case of mathematical modelling of flows in the water supply network, particularly during the determination of nodal water demands in the context of Extended Period Simulation (EPS). Considering the...
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Synergistic effect of multi walled carbon nanotubes and reduced graphene oxides in natural rubber for sensing application
PublicationUtilizing the electrical properties of polymer nanocomposites is an important strategy to develop high performance solvent sensors. Here we report the synergistic effect of multi walled carbon nanotubes (MWCNTs) and reduced graphene oxide (RGO) in regulating the sensitivity of the naturally occurring elastomer, natural rubber (NR). Composites were fabricated by dispersing CNTs alone and together with exfoliated RGO sheets (thermally...
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Effect of microstructure on mechanical properties of BA1055 bronze castings
PublicationThe article presents research results performed on aluminum bronze CuAl10Fe5Ni5 (BA1032) castings used for marine propellers. Metallographic studies were made on light microscope and a scanning electron microscope to assess quantitatively and qualitatively the alloy microstructure. It has been shown that the shape, size and distribution of the iron-rich phase precipitates in bronze microstructure significantly affect its mechanical...
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Performance Analysis of the "Intelligent" Kirchhoff- Law - Johnson-Noise Secure Key Exchange
PublicationThe Kirchhoff-law - Johnson-noise (KLJN) secure key distribution system provides a way of exchanging theoretically secure keys by measuring random voltage and current through the wire connecting two different resistors at Alice’s and Bob’s ends. Recently new advanced protocols for the KLJN method have been proposed with enhanced performance. In this paper, we analyze the KLJN system and compare with the „intelligent” KLJN (iKLJN)...
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Representation of magnetic hysteresis in single-phase transformer for circuit simulations
PublicationThe paper presents a mathematical model for the hysteresis phenomenon in a multi-winding single-phase core type transformer. In the circuit transformer model, it is assumed that there is a flux common Φ to all windings as nonlinear and hysteretic function of the total currents Θ (Ampere turns) of all windings. To simulate magnetic behaviour of the iron core the feedback scalar Preisach model of hysteresis is developed. The Preisach...
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Treatment Wetland for Overflow Stormwater Treatment: The Impact of Pollutant Particles Size
PublicationThe problem of stormwater treatment in urban areas has become increas- ingly crucial. It has been widely recognized that both mechanical and biological treatment of stormwater is necessary to protect surface water against pollution. Moreover, technology must be applied to ensure effective treatment in changing hydraulic conditions and to serve, to the extent possible, as a retention volume. Treatment wetland (TW) could be...
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Nonlinear viscoelasticity in Three Dimensional filler reinforced rubber composites and nanocomposites
PublicationThis chapter describes the influence of three-dimensional nanofillers used in elastomers on the nonlinear viscoelastic properties. In particular, this part focuses and investigates the most important three-dimensional nanoparticles, which are used to produce rubber nanocomposites. The rheological and the dynamic mechanical properties of elastomeric polymers, reinforced with spherical nanoparticles, like POSS, titanium dioxide and...
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Winding function approach based design of novel five-phase brushless doubly fed induction generator
PublicationThe paper presents the concept of the new design of the five-phase brushless doubly fed induction generator. The generator is dedicated to the modern wind turbine. The innovative design approach uses a five-phase power supply from the stator control winding side of the generator with a stator three-phase classic power winding. The research results presented indicate that the electromagnetic coupling between the control and power...
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Diagnosing marine turbine engines through energy characteristics of their flow section
PublicationThe aim of the performed research was to develop of diagnostic method of the flow section of a marine turbine combustion engine based on the level of delamination of its energy characteristics. The here adopted diagnostic model provides for a formulation of the evaluation of the technical conditions based on the measurements of the parameters of the thermodynamic medium in the characteristic control cross-sections of the engine...
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Rotor-Flux Vector based Observer of Interior Permanent Synchronous Machine
PublicationThe sensorless control system of the interior permanent magnet machine is considered in this paper. The control system is based on classical linear controllers. In the machine, there occurs non-sinusoidal distribution of rotor flux together with the slot harmonics, which are treated as the control system disturbances. In this case, the classical observer structure in the (d-q) is unstable for the low range of rotor speed resulting...
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A pin-on-disc study of airborne wear particle emissions from studded tyre on concrete road contacts
PublicationStudded tyres wear surfaces of winter roads, generating inhalable airborne particles. In this study, four concrete road materials and two stud geometries were investigated in terms of wear, road material hardness and airborne particle concentration. The sliding contact between studded tyres and road materials was studied using a pin-on-disc machine in a clean chamber. The results show that the normal load and the stud size have...
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Notch fatigue analysis and life assessment using an energy field intensity approach in 7050-T6 aluminium alloy under bending-torsion loading
PublicationThis paper studies the fatigue crack initiation and fatigue crack propagation of notched cylindrical bars made of 7050-T6 aluminium alloy subjected to multiaxial bending-torsion loading. The sites of crack initiation and the angles of crack initiation were successfully predicted from the distribution of the first principal stress at the notch surface. Fatigue crack initiation lives were computed through the new concept of energy...
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Multiple access in ad-hoc wireless LANs with noncooperative stations
PublicationA class of contention-type MAC protocols (e.g., CSMA/CA) relies on random deferment of packet transmission, and subsumes a deferment selection strategy and a scheduling policy that determines the winner of each contention cycle. This paper examines contention-type protocols in a noncooperative an ad-hoc wireless LAN setting, where a number of stations self-optimise their strategies to obtain a more-than-fair bandwidth share. Two...
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FE analysis of a coupled energetic-statistical size effect in plain concrete beams with varying material properties.
PublicationThe numerical FE investigations of a coupled energetic-statistical size effect in unnotched concrete beams of similar geometry under quasi-static three point bending were performed within elasto-plasticity with non-local softening. The stochastic FE analyses were carried out with three different beam sizes. Deterministic calculations were performed with the uniform distribution of a uniaxial tensile strength. In statistical calculations...
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SYNTHESIS AND STRUCTURAL CHARACTERIZATION OF NIOBIUM-DOPED HYDROXYAPATITE CERAMICS
PublicationHydroxyapatite (HAp) ceramic materials are considered as one of the most promising implant materials in bone surgery and in dentistry. They exhibit unique biocompatibility, bioactivity, and osteoconductivity, which are the most desirable biomaterial features. However, HAp itself is brittle, has low strength, high degree of crystallinity and low solubility at physiological pH. Doping synthetic HAp with metal ions plays an important...
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Spatio-Temporal Validation of GNSS-Derived Global Ionosphere Maps Using 16 Years of Jason Satellites Observations
PublicationExisting ionospheric models perform very well in mapping the calm state of the ionosphere. However, the problem is accurately determining the total electron content (TEC) for disturbed days. Knowledge of the exact electron density is essential for single−frequency receivers, which cannot eliminate the ionospheric delay. This study aims to investigate temporal and spatial variability in the distribution of TEC based on differences...
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Effects of FSW Tool Plunge Depth on Properties of an Al-Mg-Si Alloy T-Joint: Thermomechanical Modeling and Experimental Evaluation
PublicationOne of the main challenging issues in friction stir welding (FSW) of stiffened structures is maximizing skin and flange mixing. Among the various parameters in FSW that can affect the quality of mixing between skin and flange is tool plunge depth (TPD). In this research, the effects of TPD during FSW of an Al-Mg-Si alloy T-joint are investigated. The computational fluid dynamics (CFD) method can help understand TPD effects on FSW...
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Rozdział mocy w układzie napędowym robota podwodnego - porównanie algorytmów alokacji naporów
PublicationPraca dotyczy syntezy systemu automatycznego sterowania robotem podwodnym w zakresie problemu rozdziału mocy w wielopędnikowym układzie napędowym. Do alokacji naporów zastosowano metody optymalizacji z ograniczeniami, pozwalające na wyznaczanie wektora naporów na podstawie wektora sił uogólnionych. Rozważono i porównano dwie metody rozdziału mocy dla robota realizującego ruch poziomy płaski o trzech stopniach swobody, rozpatrując...
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Influence of drying mode and feed per tooth rate on the fine dust creation in pine and beech sawing on a mini sash gang saw
PublicationThe experimental results of the study focused on the effect of drying processes of modified air drying and warm air steam mixture drying of pine and beech wood on the size of sawdust particles created in cutting using PRW-15M sash gang saw, are presented in the paper. Particle size analysis of dry sawdust was performed using two methods—sieving method and laser diffraction analysis. The results showed that the drying process did...
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A material model of asphalt mixtures based on Monte Carlo simulations
PublicationThe paper aims to numerically reflect mineral-asphalt mixture structure by a standard FEM software. Laboratory test results are presented due to bending tests of circular notched elements. The result scatter is relatively high. An attempt was made to form a random aggregate distribution in order to obtain various results corresponding to laboratory tests. The material structure calibration, its homogenization and finite element...
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E-textbook technologies for academics in medical education
PublicationPublic universities in Poland receive fairly limited financial support for creating e-textbooks and lack the appropriate ICT competences among teaching staff, especially in the case of non-technical universities. The authors propose a pedagogical and technological paradigm for e-textbooks in medical education using open source software with minimal IT skills required. Technologies used to develop e-textbooks are connected with:...
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NUMERICAL MODELLING AND EXPERIMENTATION OF HISTORICAL CARPENTRY CORNER LOG JOINTS
PublicationThe main purpose of this research is to determine the stress distributions on the contact surfaces between the logs of the historical carpentry corner joints. The additional purpose is to compare the stress distribution for four different boundary conditions in the case of dry and wet pine wood. The paper presents the results of numerical analysis of the shortcorner dovetail connection and the saddle notch corner joint, which are...
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Rain Water: Atmospheric Deposition
PublicationWater is transferred from the atmosphere to the land surface mainly via various forms of atmospheric precipitation; however, the contribution of surface condensation/deposition (e.g., dew, hoar frost, occult precipitation) should not be neglected. Rainwater and liquid deposits (dew, hoar frost, rime) are components of the physical and geographical environment that are easily assimilated and transported. Thus, they are generally...
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Calculations of labyrinth seals with and without diagnostic extraction in fluid-flow machines
PublicationLabyrinth seals are essential components of steam turbine unit constructions. Two types of labyrinth seals can be named, the first of which is the seal without diagnostic steam extraction, and the second – with extraction. The distribution of flow parameters along the packing is affected remarkably by the average seal clearance. The presence of diagnostic extraction leads to the equation system which is determinable and can be...
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An influence of the ship's block coefficient implementation on the evaluation of it's hull girder bending
PublicationAn influence of the three different ways of implementation ship's block coefficient δ (three geometrical models) on the stresses due to wave bending moment have been investigated. Two models have been applied and compared: beam one (description of the shape usingparameters) and FEM shell model (direct representation of the shape). The outcomes have been compared to Polish Register of Shipping (PRS) rules. The results show that...
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The use of Markov chains in the social convergence analysis
PublicationThe main goal of this article is to analyze the social convergence process using Markov chains. In this research, term social convergence refers to the reduction of dispersion in the standard of living among countries. The use of Markov chains in the social convergence analysis allowed describing movements of observational units within the distribution and providing more details about the mechanism of the convergence process. A...
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Sound Field Intensity Measurements and Visualization around the Human Head Model . Rozkłąd natężenia pola akustycznego w komorze bezechowej obecności sztucznej głowy i w przypadku braku jej obecności
PublicationThe main goal of this research study was to measure and visualize sound field intensity distribution in and without presence of the human head model. Measurements were performed in the anechoic chamber with the 5 cm grid. Experimental setup consisted of a multitone generator, two loudspeakers, human head model, intensimetric probe, the Cartesian robot applied for precise positioning of the acoustic sensor, and an analyzer. Based...
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On the correlation between magnetoacoustic emission and magnetostriction dependence on the applied magnetic field
PublicationThe correlation between magnetoacoustic emission signal envelopes and magnetostriction curves is investigated. Two sets of samples are being considered: tempered martensitic steel and plastically deformed ferritic steel. It is shown that even though some general relations may be observed, as was demonstrated in the literature, the correlation is not always present. One may not expect to change both quantities in the same way if...
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Shell model of multiple-row moment I-section end-plate joint
PublicationThe paper deals with a problem of application of shell elements in the models of multiple-row moment end-plate connections. The extended connection of I-section with a cross-section W760x265x220 made of steel S355 was analyzed. Comparison analysis of FEM, complex volume and shell models has been done. Three cases with different end-plate thickness: 14, 18 and 36 mm were analyzed and compared with the reference results. Comparison...