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Wyniki wyszukiwania dla: finite elements method
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A method to determine the tightening sequence for standing rigging of a mast
PublikacjaThe article proposes an alternative method to determine the sequence of generation of pre-tension forces in standing rigging of a mast. The proposed approach has been verified on both a virtual simulation experiment and laboratory tests. In this method, the desired tension values are obtained using the influence matrix which allows to calculate the effect of tension change in an individual rope on the tension distribution in the...
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Galerkin formulations of isogeometric shell analysis: Alleviating locking with Greville quadratures and higher-order elements
PublikacjaWe propose new quadrature schemes that asymptotically require only four in-plane points for Reissner–Mindlin shell elements and nine in-plane points for Kirchhoff–Love shell elements in B-spline and NURBS-based isogeometric shell analysis, independent of the polynomial degree p of the elements. The quadrature points are Greville abscissae associated with pth-order B-spline basis functions whose continuities depend on the specific...
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Striking elements - A lifebelt or a fad? Searching for an effective way of adapting abandoned churches.
PublikacjaAre avant-garde elements added to historical objects as a temporary fashion to fulfill the aspirations of designers or an attempt to draw attention to themselves? It may be the exact opposite, and this type of controversial project is the best lifebelt for such monuments. This article explores issues related to external avant-garde elements added to adapted churches and their influence on the efficiency of such adaptation projects....
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FINITE GROUND CPW-FED UWB ANTENNA OVER THE METALLIC CYLINDRICAL SURFACES
PublikacjaThe investigation of finite ground coplanar fed ultra-wideband (UWB) antenna and the influence of its curvature and the proximity of circular metallic screen on the reflection coefficients and radiation characteristics is presented. The antenna is composed of two circular coplanar strips which enclose slot aperture of similar shape and is designed on a thin and flexible substrate which allows its bending. The antenna configuration...
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Investigation on the Sources and Impact of Trace Elements in the Annual Snowpack and the Firn in the Hansbreen (Southwest Spitsbergen)
PublikacjaWe present a thorough evaluation of the water soluble fraction of the trace element composition (Ca, Sr, Mg, Na, K, Li, B, Rb, U, Ni, Co, As, Cs, Cd, Mo, Se, Eu, Ba, V, Ge, Ga, Cr, Cr, P, Ti, Mn, Zr, Ce, Zn, Fe, Gd, Y, Pb, Bi, Yb, Al, Nb, Er, Nd, Dy, Sm, Ho, Th, La, Lu, Tm, Pr, Tb, Fe, In, Tl) and their fluxes in the annual snowpack and the firn of the Hansbreen (a tidewater glacier terminating in the Hornsund fjord, southwest...
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Computational algorithm for the analysis of mechatronic systems with distributed parameter elements
PublikacjaThe paper presents a systematic computational package for analysis of complex systems composed of multiple lumped and distributed parameter subsystems. The algorithm is based on the transfer function method (DTFM). With this algorithm, a bond graph technique for the modelling is developed to simplify computations. Analysis of different systems requires only changing the inputs data in the form of the bond graph diagram
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The impact of sediment, fresh and marine water on the concentration of chemical elements in water of the ice-covered lagoon
PublikacjaThe common use of chemical elements by man has been contributing to their extraction for centuries. As a consequence, they have been directly or indirectly introduced into the biogeochemical cycle. In the framework of many conventions, mining and processing of elements are currently subject to many restrictions. However, their large load that has already been deposited in the soil and bottom sediments can be remobilised and...
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The Role of Daylight in Forming the Traditional Space: Classification of Traditional Iranian Daylighting Elements
PublikacjaDaylight character in a space can be defined as the manner in which daylight permeates and is dispersed in that space. The architectural elements related to daylighting under investigation in this study were rooted in Iranian-Isfahani heritage, considered traditional Iranian architecture (from the 16th to early 20th century). The establishment of a classification system for daylighting systems holds significant utility. This...
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Concrete elements cast in febric forms
PublikacjaPrzedstawiono wyniki badań wytrzymałościowych elementów betonowych wylewanych w wiotkich formach wykonanych z materiałów syntetycznych. Badania przeprowadzono dla modelu ściany/słupa. Zbadano mechaniczne i chemiczne własności 10 różnych materiałów syntetycznych. Wybrano materiał o przepuszczalności umożliwiającej wykonanie monolitycznej konstrukcji. Z 12 zbadanych mieszanek betonowych do dalszej analizy wyselekcjonowano trzy. Badania...
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A screening of select toxic and essential elements and persistent organic pollutants in the fur of Svalbard reindeer
PublikacjaReindeers play an important role in the polar ecosystem, being long-lived sole vegetarians feeding on local vegetation. They can be used as a valuable bioindicator, helping us to understand contaminants’ impact on the polar terrestrial ecosystem. Still, scarce data exist from research in which polar herbivores (especially those from the European parts of the Arctic) were a major study subject for trace elements and persistent organic...
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Accuracy of the Discrete Green's Function Formulation of the FDTD Method
PublikacjaThis paper reports an evaluation of the accuracy of the discrete Greens function (DGF) formulation of the finite-difference time-domain (FDTD) method. Recently, the closed-form expression for the DGF and its efficient numerical implementation were presented, which facilitates applications of the DGF in FDTD simulations of radiation and scattering problems. So far, the accuracy of the DGF formulation of the FDTD method has been...
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Thermal Imaging Aided Assessment of a State of Equipment Under Test and its Protecting Elements
PublikacjaIn the paper the investigation results using thermal imaging methods are presented. The examined is a state of equipment under test and its protecting components. The estimations are done for the chosen protecting elements during surge immunity testing. The results show that the thermal imaging methods are useful for early detection of possible damage of a device being tested
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A finite element analysis of thermal energy inclination based on ternary hybrid nanoparticles influenced by induced magnetic field
PublikacjaThe 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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Badania eksperymentalne i symulacyjne dynamiki modelowego odcinka sieci trakcyjnej
PublikacjaW pracy przedstawiono główne założenia i strukturę opracowanego modelu matematycznego odcinka kolejowej górnej sieci trakcyjnej, opartego na metodzie energetycznej Lagrange’a. W celu wyznaczenia wybranych parametrów modelu, jak również dla oceny stopnia zgodności odwzorowania przez utworzony program symulacyjny stanów statycznych i dynamicznych sieci zbudowano laboratoryjny model odcinka sieci jezdnej z użyciem rzeczywistych jej...
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Otwarte innowacje w inicjatywach klastrowych
PublikacjaSpecyfika funkcjonowania inicjatyw klastrowych czyni z nich idealne podłoże do wcielania w życie idei open innovation – ułatwiają bowiem nawiązywanie kontaktów z innymi podmiotami, stawiają na otwartość swoich członków i budowę relacji opartych na zaufaniu, stanowią platformę wymiany zasobów (w tym przede wszystkim informacji i wiedzy) oraz wspólnego kreowania rozwiązań innowacyjnych. W artykule podjęto rozważania teoretyczne dotyczące...
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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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M-integral for finite anti-plane shear of a nonlinear elastic matrix with rigid inclusions
PublikacjaThe path-independent M-integral plays an important role in analysis of solids with inhomogeneities. However, the available applications are almost limited to linear-elastic or physically non-linear power law type materials under the assumption of infinitesimal strains. In this paper we formulate the M-integral for a class of hyperelastic solids undergoing finite anti-plane shear deformation. As an application we consider the problem...
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Cost Analysis of Prefabricated Elements of the Ordinary and Lightweight Concrete Walls in Residential Construction
PublikacjaGlobal economic growth causes an increase in natural resources exploitation, particularly in construction branch. The growing use of electricity contributes to climate change. Therefore, it is necessary to search the solutions, which will allow for reducing natural resources exploitation. One of the many opportunities to do that is the application of the recycled materials. The authors of the given article have analyzed three variants...
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Trace elements content of surface peat deposits in the Solovetsky Islands (White Sea)
PublikacjaPeatlands form environmental archives of trace element deposition. In this regard they are particularly valuable for areas such as the Arctic, where regular pollution monitoring is either impossible or extremely costly. The aim of this study was to assess pollution in the Solovetsky Islands (65° 05' N, 35° 53' E) by examining the spatial variability in trace element content of the uppermost layer of peat, immediately below the...
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3-D finite-difference time-domain modelling of ground penetrating radar for identification of rebars in complex reinforced concrete structures
PublikacjaThis paper presents numerical and experimental investigations to identify reinforcing bars using the ground penetrating radar (GPR) method. A novel element of the paper is the inspection of different arrangements of reinforcement bars. Two particular problems, i.e. detection of few adjacent transverse bars and detection of a longitudinal bar located over or under transverse reinforcement, have been raised. An attention was also...
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Effects of biotransport and hydro-meteorological conditions on transport of trace elements in the Scott River (Bellsund, Spitsbergen)
PublikacjaThe shaping of surface water chemistry in the Svalbard Archipelago is strongly dependent on the geology of the catchment and the process of long-range transport of atmospheric pollutants (LRATP). It was found that the dissolved trace elements in the Scott River, which catchment is characterized by a decreasing degree of glaciation, were of the natural origin (i.a. weathering and dissolution of local geological substratum). The...
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Parametrized Local Reduced-Order Models With Compressed Projection Basis for Fast Parameter-Dependent Finite-Element Analysis
PublikacjaThis paper proposes an automated parametric local model-order reduction scheme for the expedited design of microwave devices using the full-wave finite-element method (FEM). The approach proposed here results in parameterized reduced-order models (ROMs) that account for the geometry and material variation in the selected subregion of the structure. In each subregion, a parameter-dependent projection basis is generated by concatenating...
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THE POSSIBILITIES OF ESTIMATING THE RELIABILITY OF SHIP PIPELINES’ ELEMENTS INCLUDING DESTRUCTIVE PHENOMENA ACTING ON THEM
PublikacjaIn the article an approach to the problem of estimating reliability data based on physical models is proposed. The possibility of reliability assessment for selected elements of ship pipelines, based on the recognition of the destructive physical phenomena taking place in them, is discussed. To do this, an overview of these phenomena has been made. In addition, a preliminary review of existing measures of destruction of materials...
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Enviromental factors az the elements determingthe development of floating homes
PublikacjaThe popularity of Floating Homes in Western Europe and North America is noticeable. The interest in thesefacilities in Poland is also constantly growing. The popularity of Floating Homes is due to climate change, risingland prices and population density in city centers. However, environmental factors play a significant role in theirdevelopment. The publication presents the results of research on the impact of environmental factors...
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OpenGL accelerated method of the material matrix generation for FDTD simulations
PublikacjaThis paper presents the accelerated technique of the material matrix generation from CAD models utilized by the finite-difference time-domain (FDTD) simulators. To achieve high performance of these computations, the parallel-processing power of a graphics processing unit was employed with the use of the OpenGL library. The method was integrated with the developed FDTD solver, providing approximately five-fold speedup of the material...
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Finite-difference analysis of a loaded hemispherical resonator
PublikacjaPrzedstawiono analizę osiowo symetrycznej struktury otwartego rezonatora he-misferycznego zawierającego warstwowe ośrodki dielektryczne. W analizie wy-korzystano metodę różnic skończonych w dziedzinie częstotliwości (FDFD). Wcelu osiągnięcia wysokiej dokładności obliczeń zastosowano zaawansowane me-tody modelowania warunków brzegowych i granicznych.
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Finite automata for compact representation of tuple dictionaries.
PublikacjaOpisane zostaje uogólnienie struktury danych - słownika, zwane słownikiem n-tek. Słownik n-tek przedstawia odwzorowanie n-tek łańcuchów znaków na pewne wartości. Motywacją dla powstania tej struktury danych są praktyczne zastosowania w przetwarzaniu języka i mowy, w których obszerne słowniki n-tek używane są do przedstawiania modeli języka. Przedstawiona zostaje technika oszczędnej reprezentacji słowników n-tek. Ta technika...
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Dynamic Perfect hashing with finite-state automata
PublikacjaMinimalna doskonała funkcja mieszająca dostarcza odwzorowania zbioru n niepowtarzalnych słów w zwarty zakres n liczb całkowitych. Gdy jest realizowane za pomocą automatów skończonych, odwzorowanie wynika z porządku słów (zwykle alfabetycznego) w zbiorze. Dodanie nowych słów zmieniłoby porządek słów rozpoznawanych przez automat, zmieniając całe odwzorowanie i czyniąc je bezużytecznym w wielu dziedzinach. Dlatego nazywamy je statycznym....
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Natural language dictionaries implemented as finite automata
PublikacjaRozdział przedstawia wykorzystanie automatów skończonych jako słowników języka naturalnego. Podane są podstawy teoretyczne. Omówione są zastosowania: realizacja doskonałej funkcji mieszającej, analizy i syntezy morfologicznej, poprawiania pisowni i dopisywania znaków diakrytycznych, wydobywanie informacji. Podano algorytmy tworzenia automatów oraz omówiono sposoby reprezentacji automatów z uwzględnieniem kompresji.
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Release of selected chemical elements from shale drill cuttings to aqueous solutions of different pH
PublikacjaThe effect of pH changes on leachability of light and heavy metals from shale drill cuttings generated from unconventional shale gas production was investigated. Cuttings, being the primary byproduct generated from drilling operations, belong to the potentially hazardous type of wastes due to presence of heavy and radioactive elements and remains of drilling fluid. In this regard, assessment of potentially dangerous components...
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Exposure of a small Arctic seabird, the little auk (Alle alle) breeding in Svalbard, to selected elements throughout the course of a year
PublikacjaThe Arctic marine ecosystem can be altered by processes of natural and anthropogenic origin. Spatio-temporal variation in species exposure to contamination is still poorly understood. Here, we studied elemental concentrations in the non-lethally collected samples from the most numerous seabird in European Arctic, the little auk (Alle alle) nesting in one breeding colony in Svalbard. This seabird spent the breeding season in the...
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The finite difference methods of computation of X-rays propagation through a system of many lenses
PublikacjaThe propagation of X-ray waves through an optical system consisting of many beryllium X-ray refrac- tive lenses is considered. In order to calculate the propagation of electromagnetic in the optical sys- tem, two differential equations are considered. First equation for an electric field of a monochromatic wave and the second equation derived for complex phase of the same electric The propagation of X-ray waves through an optical system...
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Numerical study on seismic response of a base-isolated building modelled with shell elements
PublikacjaSeismic isolation is counted among the most popular and effective means of protecting structures against earthquake forces. Base isolators, like Lead-Rubber Bearings (LRB), High-Damping Rubber Bearings (HDB) or Friction Pendulum Systems (FPS) are extensively used in practice in many earthquake-prone regions of the world. The present paper reports the results obtained from the numerical study on seismic response of a base-isolated...
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Visual method for detecting critical damage in railway contact strips
PublikacjaEnsuring an uninterrupted supply of power in the electric traction is vital for the safety of this important transport system. For this purpose, monitoring and diagnostics of the technical condition of the vehicle's power supply elements are becoming increasingly common. This paper presents a new visual method for detecting contact strip damage, based on measurement and analysis of the movement of the overhead contact line (OCL)...
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Parallel implementation of the DGF-FDTD method on GPU Using the CUDA technology
PublikacjaThe discrete Green's function (DGF) formulation of the finite-difference time-domain method (FDTD) is accelerated on a graphics processing unit (GPU) by means of the Compute Unified Device Architecture (CUDA) technology. In the developed implementation of the DGF-FDTD method, a new analytic expression for dyadic DGF derived based on scalar DGF is employed in computations. The DGF-FDTD method on GPU returns solutions that are compatible...
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Phytoavailability of potentially toxic elements from industrially contaminated soils to wild grass
PublikacjaTopsoil and grass samples from 14 sites located in different distances from three copper mining factories and a copper smelter were collected in Srednogorie, Bulgaria. The paper discusses results of studies on the mobility of potentially toxic elements (As, Cd, Cr, Cu, Mn, Ni, Pb, Zn) from contaminated soils to wild grass Cynodon dactylon in terms of transfer (TF: soil to plant) and phytoavailability (PF: EDTA (ethylenediaminetetraacetic...
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Evaluation of the use of reindeer droppings for monitoring essential and non-essential elements in the polar terrestrial environment
PublikacjaExcess or toxic metals, non-metals and metalloids can be eliminated from the organism by deposition in inert tissue (e.g. fur) or excretion with body secretions, urine and faeces. Droppings are one of the main routes for the elimination of multiple elements and they can be collected without direct contact with the animal. Contaminant concentration has been examined in non-lethally collected tissues of several species (especially...
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Structural properties of foil bearings: a closed-form solution validated with finite element analysis
PublikacjaFluid film thickness in a compliant foil bearing is greatly influenced by the deflection of the bearing structure. Therefore, in order to properly model performance of a foil bearing, it is mandatory that the deflection of the compliant bearing structure due to the generated hydrodynamic pressure is determined accurately. This article proposes an easy-to-use two-dimensional model, which takes into account detailed geometry of the...
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Design Elements of Affect Aware Video Games
PublikacjaIn this paper issues of design and development process of affect-aware video games are presented. Several important design aspects of such games are pointed out. A concept of a middleware framework is proposed that separates the development of affect-aware video games from emotion recognition algorithms and support from input sensors. Finally, two prototype affect-aware video games are presented that conform to the presented architecture...
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Heating of fuse - elements in transient and steady - state
PublikacjaPrzedstawiono wyniki obliczeń numerycznych nagrzewania topików bezpieczników w stanach nieustalonych i ustalonych i wykonanych w pakiecie FLUX 2D. W obliczeniach uwzględniono nagrzewania całej wkładki bezpiecznikowej. Do analizy wybrano temperaturę w przewężeniu topika. W wyniku przeprowadzonych badań stwierdzono, że przy obliczaniu parametrów przedłukowych należy uwzględniać przewodzenie ciepła w topiku oraz brać pod uwagę zmienną...
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Rare-earth elements in human colostrum milk
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Hertzian Crack Propagation in Ceramic Rolling Elements
PublikacjaThe properties of ceramics are of most interest to rolling element manufacturers. The influence of ring crack size on rolling contact fatigue failure has been studied using numerical fracture analysis. Such crack are very often found on ceramic bearing balls and decrease fatigue life rapidly. The numerical calculations are based on a three dimensional model for the ring crack propagation. The stress intensity factors along crack...
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A coupled continuous-discontinuous approach to concrete elements.
PublikacjaArtykuł omawia zastosowanie metody elementów skończonych do opisu procesu pękania elementów betonowych z równoczesnym uwzględnieniem lokalizacji odkształceń i rys. Obliczenia wykonano dla elementów poddanych zginaniu. Wyniki porównano z doświadczeniami.
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Continuous and discontinuous modeling of cracks in concrete elements
PublikacjaW artykule przedstawiono różne sposoby modelowania rys w elementach betonowych w warunkach mieszanego sposobu obciążenia przy zastosowaniu modeli ciągłych i nieciągłych. Symulacje wykonano przy zastosowaniu 3 różnych modeli ciągłych: modelu sprężysto-plastycznego, modelu w ramach mechaniki zniszczeniowej i modelu rys rozmytych z rysami obracającymi się oraz 1 modelu nieciągłego przy zastosowaniu stref kontaktu..
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Portico Farmhouses of the Vistula Delta: Architecture, Current State and Finite Element Modelling of Timber Roof Truss under Material and Cross-section Uncertainty
PublikacjaThe article focuses on the oldest surviving I-type portico houses located in the Vistula Delta, which were built in the 17th and 18th centuries. The study describes the houses’ origins, structure, details of roof structures and technical condition, and it also includes numerical modelling of a roof truss and its mechanical analysis. Numerical models of the roof trusses are defined and analysed by means of the finite element method....
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Experimental investigation and process parameter optimization of sheet metal bending by line heating method
PublikacjaThe present study is concerned with the experimental investigation of sheet metal deforming by line heating method that incorporates the combined effect of traverse speed of the torch, thickness of the sheet metal, and the number of passes of the torch. For the numerical analysis of metal bending by line heating, the
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Assessment of technical condition and repair of steel structure elements on the example of fire damage in a warehouse building
PublikacjaThe paper analyses a case study on the structural assessment of warehouse building partially damaged by fire caused by external source (fire of lorries close to the building). The authors focus on the site investigations and laboratory test results prior to assessing actual condition of the structural elements. Both strengthening concept and repair procedure of a steel column are addressed here. A short literature survey in the...
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Phytoextraction and recovery of rare earth elements using willow (Salix spp.)
PublikacjaSoil and water contaminations are caused by rare earth elements (REEs) due to mining and industrial activities, that threaten the ecosystem and human health. Therefore, phytoremediation methods need to be developed to overcome this problem. To date, little research has been conducted concerning the phytoremediation potential of Salix for REEs. In this study, two Salix species (Salix myrsinifolia and Salix schwerinii) and two Salix...
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AN OVERVIEW OF HEAT TRANSFER ENHANCEMENT BASED UPON NANOPARTICLES INFLUENCED BY INDUCED MAGNETIC FIELD WITH SLIP CONDITION VIA FINITE ELEMENT STRATEGY
PublikacjaThe mathematical model of heat generation and dissipation during thermal energy transmission employing nanoparticles in a Newtonian medium is investigated. Dimensionless boundary layer equations with correlations for titanium dioxide, copper oxide, and aluminium oxide are solved by the finite element method. Parameters are varied to analyze their impact on the flow fields. Various numerical experiments are performed consecutively...
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Research of electric drive systems with real time software configurable control
PublikacjaПредмет исследования. Представлен учебно-лабораторный стенд для исследования систем управления элек- троприводами. Стенд используется для обучения студентов системам управления электроприводами и предна- значен для повышения эффективности усвоения материала. Метод. В основу предлагаемого решения положен метод взаимного нагружения электрических машин, питаемых от силовых преобразователей с общим звеном постоянного тока. Это позволяет...