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Evolution of Physical Properties of RE 3 Ni 5 Al 19 Family (RE = Y, Nd, Sm, Gd, Tb, Dy, Ho, and Er)
PublikacjaSingle crystals of RE3Ni5Al19 series (RE = Y, Nd, Sm, Gd, Tb, Dy, Ho, and Er) are grown using the Al self-flux method. The crystal structure is examined by both single crystal and powder X-ray diffraction. Physical properties are studied for the first time for RE3Ni5Al19 (RE = Y, Nd, Gd, Tb, Dy, Ho, and Er) by means of magnetic susceptibility, electrical resistivity, and heat capacity measurements. Complex magnetic behaviors, with...
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Probabilistic estimation of diverse soil condition impact on vertical axis tank deformation
PublikacjaThe calculations of fuel tanks should take into account the geometric imperfections of the structure as well as the variability of the material parameters of the foundation. The deformation of the tank shell can have a significant impact on the limit state of the structure and its operating conditions. The paper presents a probabilistic analysis of a vertical-axis, floating-roof cylindrical shell of a tank with a capacity of 50000...
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Ocena stanu technicznego konstrukcji zgarniaczy będących na wyposażeniu osadników wstępnych Grupowej Oczyszczalni Ścieków „DĘBOGÓRZE
PublikacjaOsadniki wstępne typu DORRA – 4 szt., o pojemności 1830 m3, wyposażone są w elementy mechaniczne do kierunkowego przemieszczania się osadu w kierunku leja centralnego. Celem pracy jest ocena stany technicznego części mechanicznej, a w szczególności: - konstrukcji zespołu zgarniania części pływających oraz osadu. - zespołu napędu i sterowania, - zespołu napędu i jazdy. Pierwsze dwa zespoły będą oceniane również z punktu widzenia...
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Korozja i zniszczenia kształtowników stalowych o przekrojach zamkniętych
PublikacjaW artykule przedstawiono spotykany na obiektach budowlanych problem rozwoju korozji na wewnętrznych powierzchniach kształtowników zamkniętych eksploatowanych w środowisku zewnętrznym. Zachodzące wewnętrzne procesy korozyjne oraz towarzyszące im siły niszczące w związku z zamarzającą wewnątrz profili wodą, powodują utratę nośności i obniżenie bezpieczeństwa eksploatacji, przez co przyczyniają się do powstawania stanów awaryjnych....
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Diagnosis of bearing damage in induction motors by instantaneous power analysis
PublikacjaResearch of the machine with simulated bearing damages has been carried out, where variable load torque, simulating bearing damage, was introduced. The results show that components which can be used for bearings diagnosis appear in the spectrum of the product of current and supply voltage instantaneous values. These components are easier to identify than the components of current spectrum, which have been used so far in diagnostic...
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Polyurethanes as a carrier of drugs for gentamicin
PublikacjaGentamicin is one of the most popular drug and is widely used due to its antibiotic properties. 3% of world production of polyurethanes (PU) is dedicated to biomedical applications, where they can serve are parts of orthopedic prosthesis or artificial organs, disposable medical devices, wound and burn dressing, contact lenses among others. In the study, to obtain drug carriers, a combination of these two materials were prepared...
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Stability of roof trusses stiffened by trapezoidal sheeting and purlins
PublikacjaIn the article linear buckling analysis of a set of steel trusses braced by purlins and trapezoidal sheeting are conducted. The buckling load factor due to the height of a corrugated sheeting profile is investigated in parametric studies. The minimal height of trapezoidal sheeting required for preventing the sheeting and chords of the trusses against the buckling is obtained. Two groups of models are considered: “axial” model as...
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FEM Calculations in Analysis of Steel Subsea Water Injection Flowlines Designing Process
PublikacjaPaper describes the result of theoretical research aimed at assessing the loads and operating conditions of a Coiled Tubing pipeline injecting water, suspended to the mining platform of Lotos Petrobaltic. For this purpose, appropriate calculation models have been developed using the Finite Element Method (FEM), taking into account the nature of the analyzed object and its loads. The analyzes were carried out for two pipes (previously...
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Decentralized control of a different rated parallel UPS systems
PublikacjaThe paper presents the single phase uninterruptible power supply (UPS) system with galvanic separated DC-AC-DC-AC converters operating in parallel. The CAN physical layer based system of communication between converters has been developed and applied, which allow to utilize a decentralized master-slave control providing high availability factor of the whole UPS system. The control system of particular converters has been developed...
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Application of guided waves in the evaluation of steel-concrete adhesive connection
PublikacjaThe aim of the paper is the application of guided waves in the evaluation of a condition state of adhesive connection between steel and concrete. The study concerns a push-out specimen consisting of two steel plates glued to opposite faces of a concrete cube with the use of structural adhesive. Wave propagation in the specimen without external load is investigated both experimentally and numerically. The second stage of the investigation...
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Power electronic transformer based on cascaded H-bridge converter
PublikacjaIn this paper the control strategy of power electronic transformer (PET) is proposed. The analyzed structure of PET uses two seven-level cascaded H-bridge (CHB) rectifiers. The electrical power of PET is transferred between DC-links of CHB converters using dual-active-bridges (DABs) and low voltage high frequency transformers. The roposed solution allows for controlling the active and reactive power with a low level of harmonic...
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Five-phase squirrel-cage motor. Construction and drive properties
PublikacjaThis paper presents the simulation and experimental results of a five-phase squirrel-cage induction motor. The new machine has been designed to operate in a drive system with third harmonic rotor flux injection in order to improve the motor torque utilization. The motor structure, the mathematical model as well as the laboratory prototype have been described. The motor speed-torque characteristics and transients are elaborated...
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Evaluation of Wear Resistance of Ti alloys used for elements friction of knee endoprosthesis
PublikacjaThe paper presents research results of resistance to abrasive wear of titanium alloys: Ti6Al4V (commonly used) and Til3Nb13Zr (alloy of new generation) in association with polyethylene (UHMW-PE) predisposed for elements on pair of the knee endoprosthesis. The results were analysed from the point of possibility of an use of new generation titanium alloys as components of such implants. The tests of resistance to abrasive wear of...
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Mechanical characterization of a gravel column in a calibration chamber operating as a triaxial cell
PublikacjaA series of tests considering the behavior of gravel columns was performed. A segment of column with a height of 1 m and a diameter of 0.53 m was modelled in a calibration chamber used as a triaxial cell at three different lateral stress applied. The vertical load transferred on the column head was simulated with steady increase of water pressures in the upper and lower membranes. During the loading the volumetric changes in the...
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On the durability of the hydraulic satellite motor working mechanism in overload condition
PublikacjaThe paper presents the newest construction of the hydraulic satellite pump/motor. In this study, the fracture of the hydraulic satellite motor working mechanism is investigated. Factors influencing the durability of satellite working mechanism have been described. The durability of the hydraulic satellite motor working mechanism at a load, corresponding to a pressure of 15 MPa supplied with refined rapeseed oil is very low. Analyses...
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THE PHASE SHIFTERS INFLUENCE ON THE POWER SYSTEM STABILITY
PublikacjaThe paper presents the effect of phase shifters as FACTS devices on the possibility of improving the angle stability. Presented results obtained by the dynamic simulation performed on the mathematical model of the three machine system cooperating with the 400 kV network. The generative blocks models include turbine models with their controllers and models of synchronous generators with their excitation systems and voltage regulation....
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Stability of an imperfect truss loaded by wind
PublikacjaThe present paper is devoted to the numerical research of stability of a truss loaded by wind and stiffened by elastic supports located at the top chord. The lateral braces or lateral and torsional braces were taken into account. In this paper, the linear buckling analysis re- sults for the beam and shell model were presented. Two different shapes of initial geometric imperfections were considered in the non-linear static analysis...
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Simultaneous voltammetric determination of Cd2+, Pb2+, and Cu2+ ions captured by Fe3O4@SiO2 core-shell nanostructures of various outer amino chain length
PublikacjaIn the present study, we examined a novel functionalised magnetic nanoparticles Fe3O4@SiO2-Nn as a nano adsorbent for binding of Cd2+, Pb2+, Cu2+ ions in an aqueous solution. First, we obtained the nanoparticles functionalised with various carbon chains containing different number of amino groups: (3-amino)propyltriethoxysilane (Fe3O4@SiO2-N1), N-(2-aminoethyl)-3-aminopropyltrimethoxysilane (Fe3O4@SiO2-N2) and N1-(3-trimethoxysilylpropyl)diethylenetriamine...
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Porous carbon derived from rice husks as sustainable bioresources: insights into the role of micro-/mesoporous hierarchy in hosting active species for lithium–sulphur batteries
PublikacjaThe exploration of natural resources as sustainable precursors affords a family of green materials. Exploring highly abundant and available biowaste precursors remaining from food processing throughout a scalable and cost-effective material synthesis path is highly important especially for new materials discovery in emerging energy storage technologies such as lithium–sulphur (Li–S) batteries. Herein, we have produced a series...
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Machine learning-based seismic response and performance assessment of reinforced concrete buildings
PublikacjaComplexity and unpredictability nature of earthquakes makes them unique external loads that there is no unique formula used for the prediction of seismic responses. Hence, this research aims to implement the most well-known Machine Learning (ML) methods in Python software to propose a prediction model for seismic response and performance assessment of Reinforced Concrete Moment-Resisting Frames (RC MRFs). To prepare 92,400 data...
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Superhydrophobic and superoleophilic melamine sponges impregnated with deep eutectic solvents for oil spill cleanup
PublikacjaThe extensive extraction of oil from the bottom of seas and oceans and its transportation by tankers increase the risk of potential environmental disasters associated with hydrocarbon fractions entering water reservoirs. Therefore, this paper presents the preparation of a simple impregnation of a melamine sponge with deep eutectic solvents (DES), which can be obtained from natural sources, including coconut oil, palm kernel oil,...
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Biomechanical causes for failure of the Physiomesh/Securestrap system
PublikacjaThis study investigates the mechanical behavior of the Physiomesh/Securestrap system, a hernia repair system used for IPOM procedures associated with high failure rates. The study involved conducting mechanical experiments and numerical simulations to investigate the mechanical behavior of the Physiomesh/Securestrap system under pressure load. Uniaxial tension tests were conducted to determine the elasticity modulus of the Physiomesh...
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Proximal fibular osteotomy as a treatment for degenerative meniscal extrusion
PublikacjaMeniscal extrusion treatment is a key focus area for research and clinical study of degenerative knee pathology. The contact forces between the meniscus and the bones cause external displacements of the meniscus that are resisted by the circumferential fibres. The main risk factors for the excessive deformation of the meniscus are meniscal root tears, disruption of the circumferential fibres, knee malalignment and high body mass...
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Switching Regulation in the Control of 5-Phase Permanent Magnet Synchronous Motor Fed by 3×5 Direct Matrix Converter
PublikacjaMatrix converter is an AC-AC direct power converter comprising of an array of bi- directional switches. It does not require an intermediate DC-link and allows sinusoidal output waveforms with varying amplitudes and frequencies. The configuration of these bi- directional switches decides the number of inputs and outputs...
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Nuclear Power Plant Steam Turbine - Modeling for Model Based Control Purposes
PublikacjaThe nature of the processes taking place in a nuclear power plant (NPP) steam turbine is the reason why their modeling is very difficult, especially when the model is intended to be used for on-line optimal model based process control over a wide range of operating conditions, caused by changing electrical power demand e.g. when combined heat and power mode of work is utilized. The paper presents three nonlinear models of NPP steam...
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Nitrogen removal in vertical flow constructed wetlands: influence of bed depth and high nitrogen loadings
PublikacjaThe aim of the study was to evaluate the nitrogen removal and its effects on the plant’s growth and leaves morphology. using two subsurface vertical flow (VF bed), with different depths (0.24 m2 × 0.70 m; 0.24 m2 × 0.35 m) and nitrogen load increments. The VF bed were planted with Vetiveria zizanioides, filled with light expanded clay aggregates (Leca®NR 10/20) and fed in parallel mode with synthetic wastewater. High ammonium nitrogen...
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Inverse Nonlinear Eigenvalue Problem Framework for the Synthesis of Coupled-Resonator Filters With Nonresonant Nodes and Arbitrary Frequency-Variant Reactive Couplings
PublikacjaA novel, general circuit-level description of coupledresonator microwave filters is introduced in this article. Unlike well-established coupling-matrix models based on frequency-invariant couplings or linear frequency-variant couplings (LFVCs), a model with arbitrary reactive frequencyvariant coupling (AFVC) networks is proposed. The engineered formulation is more general than prior-art ones—with the only restriction that the coupling...
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Study on Dry Sliding Wear and Friction Behaviour of Al7068/Si3N4/BN Hybrid Composites
PublikacjaHybrid aluminium metal matrix composites have the potential to replace single reinforced aluminium metal matrix composites due to improved properties. Moreover, tribological performance is critical for these composites, as they have extensive application areas, such as the automotive, aerospace, marine and defence industries. The present work aims to establish the tribological characteristics of Al7068/Si3N4/BN hybrid metal matrix...
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Comprehensive thermodynamic analysis of steam storage in a steam cycle in a different regime of work: A zero-dimensional and three-dimensional approach
PublikacjaDue to the current trends aiming to reduce carbon dioxide emissions by increasing the use of renewable energy sources, changes are required in the operation of coal-fired steam units. The unstable nature of renewable energy sources, depending on weather conditions, means that the amount of energy produced varies and is not always in line with peak demand. To ensure the security and stability of energy supplies in the energy system,...
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Zastosowanie redundancji w siłowniach okrętowych statków oceanotechnicznych
PublikacjaSystemy wytwarzania energii i napędu statków oceanotechnicznych muszą mieć bardzo wysoki poziom niezawodności. Utrata zdolności do wykonywania funkcji przez ich elementy strukturalne z reguły powoduje bardzo wysokie straty ekonomiczne. Straty te mogą być zwiększone przez niemożność wykorzystania tzw. okna pogodowego, skutkującego odłożeniem w czasie zaplanowanych operacji oceanotechnicznych. W celu zapewnienia niezawodnej realizacji...
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Sztuka jako wartość w procesie rewitalizacji przestrzeni miejskiej na przykładzie wybranych elewacji Drogi Królewskiej w Gdańsku
PublikacjaCelem niniejszej publikacji jest zwrócenie uwagi na rewitalizację przestrzeni miejskiej za pomocą elementów artystycznych, występujących w elewacjach architektonicznych Głównego Miasta w Gdańsku. Sztuka, która zaistniała w elewacjach odbudowywanego w latach pięćdziesiątych Głównego Miasta, dzięki gdańskim artystom, zaowocowała nowymi relacjami twórczymi pomiędzy architekturą a sztuką. Ze względu na ograniczone ramy artykułu, przedstawiamy...
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Stan awaryjny wiaduktu kolejowego w Bydgoszczy
PublikacjaW pracy przedstawiono opis stanu awaryjnego wiaduktu kolejowego. Omówiono wyniki badań in situ oraz teoretycznych analiz statyczno-wytrzymałościowych ponad 100-letniego obiektu. Przedstawiono wnioski i zalecenia dotyczące doraźnego zabezpieczenia obiektu oraz warunki jego dalszej eksploatacji.
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Stan awaryjny wiaduktu kolejowego w Bydgoszczy
PublikacjaW pracy przedstawiono opis stanu awaryjnego wiaduktu kolejowego. Omówiono wyniki badań in situ oraz teoretycznych analiz statyczno-wytrzymałościowych ponad 100-letniego obiektu. Przedstawiono wnioski i zalecenia dotyczące doraźnego zabezpieczenia obiektu oraz warunki jego dalszej eksploatacji.
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Education of Logisticians in Poland: Problems and Prospects in Students’ Opinion
PublikacjaLogistics is one of the key sectors of the Polish economy. Its value reflects not only its own capacity, but also the role it plays in ensuring the proper functioning of the entire economy. The rapid development of the industry and the highest demands on logistics solutions bring to the fore the problem of preparing a new generation of specialists in logistics. That is why the question of compliance to learning expectations of...
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Simulation of parallel similarity measure computations for large data sets
PublikacjaThe paper presents our approach to implementation of similarity measure for big data analysis in a parallel environment. We describe the algorithm for parallelisation of the computations. We provide results from a real MPI application for computations of similarity measures as well as results achieved with our simulation software. The simulation environment allows us to model parallel systems of various sizes with various components...
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Pylon foundation of a cable stayed bridge at the motorway ring road of Wrocław
PublikacjaThe largest bridge of the motorway ring road of Wroclaw is a cable stayed bridge over the Odra river near Rędzin. Due to hydrogeological conditions of the ground it was not convenient to use standard bored piles of high length. Instead shorter piles were applied with additional improvement by cement injections at the pile toes. This decision was possible by extending ground investigation program and application of numerical modeling...
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Analysis of Denoising Autoencoder Properties Through Misspelling Correction Task
PublikacjaThe paper analyzes some properties of denoising autoencoders using the problem of misspellings correction as an exemplary task. We evaluate the capacity of the network in its classical feed-forward form. We also propose a modification to the output layer of the net, which we called multi-softmax. Experiments show that the model trained with this output layer outperforms traditional network both in learning time and accuracy. We...
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Tin oxide nanoparticles from laser ablation encapsulated in a carbonaceous matrix – a negative electrode in lithium-ion battery applications
PublikacjaThis report concerns carbonaceous electrodes doped with tin(II) oxide nanoparticles. Tin nanoparticles are obtained by pulsed laser ablation in water. Crystalline nanoparticles have been encapsulated in a carbonaceous matrix formed after pyrolysis of a mixture consisting of tin/tin(IV) oxide nanoparticles and gelatine. The obtained material is characterized by means of X-ray diffraction, selected area diffraction, scanning electron...
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Mechanical, durability, depolluting and electrical properties of multifunctional mortars prepared with commercial or waste carbon-based fillers
PublikacjaCarbon-based fillers from industrial wastes and commercial ones were compared to improve the properties of lime-based mixes. As commercial fillers, graphene nanoplatelets and activated carbon were used, whereas as industrial wastes a char obtained by the gasification of biomasses and a used foundry sand were chosen. Carbon-based wastes were found to be a good cost-effective alternative to commercial carbon based fillers to increase...
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Structural Health Monitoring of Composite Shell Footbridge for Its Design Validation
PublikacjaThe paper presents the structural health monitoring system of the composite bridge for pedestrians and cyclists. The footbridge was designed and manufactured within the FOBRIDGE project. It is the first bridge in the world, which is classified as a consistent single element structural girder, made of sandwich shells, entirely produced in a single cycle. The developed structural health monitoring system, supported design process,...
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Crystal structure and low-energy Einstein mode in ErV2Al20 intermetallic cage compound
PublikacjaSingle crystals of a new ternary aluminide ErV2Al20 were grown using a self-flux method. The crystal structure was determined by powder X-ray diffraction measurements and Rietveld refinement, and physical properties were studied by means of electrical resistivity, magnetic susceptibility and specific heat measurements. These measurements reveal that ErV2Al20 is a Curie-Weiss paramagnet down to 1.95 K with an effective magnetic...
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Superconductivity of Ta-Hf and Ta-Zr alloys: Potential alloys for use in superconducting devices
PublikacjaThe electronic properties relevant to superconductivity are reported for bulk Ta-Hf and Ta-Zr body centered cubic alloys, in a large part to determine whether their properties are suitable for potential use in superconducting qbits. The body centered cubic unit cell sizes increase with increasing alloying. The results of magnetic susceptibility, electrical resistivity, and heat capacity characterization are reported. While elemental...
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Review and Indication of Key Activities for Energy Management Improvement in DC Microgrids
PublikacjaDC MicroGrids (MG) must have Energy Management Systems (EMS) to guarantee efficient, dependable, and environmentally friendly electricity. The application of Model Predictive Control (MPC), proved to be helpful due to its adaptability and capacity to use non-linear models. This paper, based on an extensive literature review, identifies and discusses the three key activities to improve the characteristics of DC microgrids, i.e.:...
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Determination of p-y curves for offshore piles based on in-situ soil investigations
PublikacjaOffshore piles are subjected to complex loads with considerable lateral component. The pile-soil response to lateral loads can be described with the p-y method. For a given depth the load–deflection relationship is built to simulate the surrounding soil stiffness. This state-of-art paper presents a brief discussion of determination methods for the p-y curves using a standard approach based on the soil parameters derived from laboratory...
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Dynamic variables limitation for backstepping control of induction machine and voltage source converter
PublikacjaDynamic variables limitation for backstepping control of induction machine and voltage source converter The paper presents the method of control of an induction squirrel-cage machine supplied by a voltage source converter. The presented idea is based on an innovative method of the voltage source converter control, consisting in direct joining of the motor control system with the voltage source rectifier control system. The combined...
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Safety of erection and repair of steel tanks with geometric imperfections using heavylift jack-up system
PublikacjaSafety analysis is performed of cylindrical vertical steel tanks during erection using heavylift jack up system. During an assembly or repair process a set of hydraulic supports is used. It allows to use the in-place lifting of heavy steel constructions on the required height. Wind can strongly influence stability of the lifted tank. Any geometric imperfections can reduce the critical or limit load. In the work failures of the...
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Evaluation Of Single Pole Auto-Reclosing Effectiveness With Nonlinear Secondary Arc Model
PublikacjaThe paper discusses two evaluation methods of single pole auto-reclosing process effectiveness in HV transmission lines. Secondary arc current and recovery voltage results obtained by load flow calculation are compared to the results obtained by the time domain simulations. Moreover, a non-linear secondary arc implementation is presented. The authors indicate, that precise representation of secondary electric arc leads to more...
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Te use of acoustic emission for assessment of the oil lubricity in a four-ball tester
Publikacjain view of the increased dynamic and temperature load in the compression-ignition engine tribological systems, particular attention is drawn to the problem of such lubrication of the friction nodes that after breaking the boundary layer it could be restored without any wear occurring. therefore, an idea has been devised of introducing to friction nodes, with the lubrication oils, of new substances (operational preparations) modifying...
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Mechanical properties of PVDF-coated fabric under tensile tests
PublikacjaThis article describes the laboratory tests necessary to identify the mechanical properties of the polyvinylidene fluoride (PVDF)-coated fabrics named Precontraint 1202S and Precontraint 1302S. First, a short survey of the literature concerning the description of coated woven fabrics is presented. Second, the material parameters for PVDF-coated fabrics are specified on the basis of biaxial tensile tests. A comparison of the 1:1...
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Numerical Modeling of Water and Ice Dynamics for Analysis of Flow Around the Kiezmark Bridge Piers
PublikacjaThis paper presents the results of a numerical model study on the effect of ice on the proposed bridge piers in the Vistula River outlet and its effect on flow conditions in the river. The model DynaRICE is used in this study, which is a two-dimensional hydro-ice dynamic numerical model developed for dynamic ice transport and jamming in rivers. To simulate river hydrodynamics in the vicinity of the bridge piers, 2-dimensional numerical...