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Search results for: OFFSHORE%20STRUCTURES
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Propagation of elastic waves in shell-like structures
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Damage detection in riveted structures by laser measurements
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Two pseudopolymorphs of licl trimers with semicubane structures
PublicationCząsteczki tytułowych związków w ciele stałym przyjmują strukturę semikubanów - jest to pierwsza tego typu struktura dla solwatowanego chlorku litu. Jej budowę można opisać jako kuban [Li4Cl4(OPEt3)4], w którym jedna z cząsteczek LiCl została usunięta. Brak tej cząsteczki, a dokładniej mostkującego atomu Li, powoduje deformację struktury kubanu. Naroża zdeformowanego kubanu stanowią trzy atomy litu pochodzące z LiCl oraz cztery...
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Molecular structures of two E-azobenzocrown ethers
PublicationRentgenowska analiza strukturalna monokryształów posłużyła do scharakteryzowania struktury izomerów E dwóch azobenzokoron: 13- i 16-członowej. Oba związki krystalizują w układzie jednoskośnym. W komórce elementarnej, w każdym przypadku znajdują się dwie niezależne cząsteczki, różniące się konformacją, szczególnie łańcucha eterowego. Porównując konformacje ''wolnych'' makrocykli z konformacjami ich kompleksów z jonami metali wskazano,...
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Wavelet analysis for damage identification in composite structures
Publicationw pracy zaproponowano metodę analizy sygnalu opartą o transformatę falkową, pozwalajacą na identyfikcaje pęknięcia zmęczeniowego w jednowymiarowych elementach konstrukcyjnych wykonanych z materialow kompozytowych
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Mechanics of Micro- and Nano-Size Materials and Structures
PublicationNanotechnology knowledge is always looking to expand its boundaries to achieve the mostsignificant benefit to human life and meet the growing needs of today. In this case, we can refer tomicro- and nanosensors in micro/nano-electromechanical systems (MEMS/NEMS). These electricaldevices can detect minimal physical stimuli up to one nanometer in size. Today, micro/nano-sensordevices are widely used in the...
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MAINTENANCE OF BASIC DRAINAGE STRUCTURES IN THE STARGARD DISTRICT
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Parameterized diagnostic module implemented in FPGA structures
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Special Issue: “Non-Destructive Testing of Structures”
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Functionality stored in the structures of cyclodextrin–porphyrinoid systems
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Wavelet Analysis for Damage Identification in Composite Structures
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Wave propagation in plate structures for crack detection
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Driverless Mobility: The Impact on Metropolitan Spatial Structures
PublicationDiffusion of emerging technologies is following the need of solving particular problems. Each innovation produce also some undesirable consequences. Many examples from the past have shown that along with the spread of each technology their side effects are accumulating until the level they need to be solved. One of the examples is automobile, which advantages and disadvantages were already described including its spatial consequences....
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Design-Oriented Constrained Modeling of Antenna Structures
PublicationFast surrogate models are crucially important to reduce the cost of design process of antenna structures. Due to curse of dimensionality, standard (data-driven) modeling methods exhibit serious limitations concerning the number of independent geometry parameters that can be handled but also (and even more importantly) their parameter ranges. In this work, a design-oriented modeling framework is proposed in which the surrogate is...
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Multipulse inverter structures with low voltage distortion
PublicationA novel approach to the voltage source inverters (VSI) construction is presented in the paper. The invented inverter structures allow to operate several DC/AC converters in parallel resulting in lower voltage distortions at extremely low switching frequency. The research presented in the paper describes such a parallel operation of the VSI’s which is possible thanks to the use of coupled inductors. The eighteen-pulse three-level...
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Using Container Structures in Architecture and Urban Design
PublicationAbstract. The paper presents the use of shipping containers in architecture and urban design. Even today, houses and apartments are still too expensive. Since 1923 architects have been improving the living conditions of citizens by building very simple, repeatable forms. With prefabrication technology it became possible to build quicker, causing house prices to decrease. Apartments in block of flats became affordable to more and...
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Meander microstrip line with defected ground structures
PublicationW artykule omówiono koncepcję miniaturyzacji sekcji linii mikropaskowej poprzez modyfikację brzegu linii oraz warstwy metalizacji masy. W pracy zaprezentowano projekt oraz wyniki eksperymentu sprzęgacza gałęziowego skonstruowanego w oparciu o linię meandrową z zaburzoną warstwą metalizacji masy. Pomierzone charakterystyki transmisyjne potwierdzają atrakcyjność zastosowanych metod redukcji zajmowanej przez układ powierzchni. Osiągnięto...
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Recent steel structures in Poland - the selected projects
PublicationThe paper presents selected examples of recently completed steel structures in Poland. These are roofs over sport stadiums, construction of public buildings and bridges. Described examples do not exhaust the acquis in the field of steel constructions in Poland. The authors, however, may hope that the presented con-structions represents current achievements in Poland in the field of steel structures.
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The Factors Affecting Group Identity of Cluster Structures
PublicationThe paper provides a new approach to cluster analysis, basing on a sociologically rooted concept of identity. The authors state that identity in cluster structures is formed by two main groups of factors – uncontrollable or slightly controllable factors (identity mix) and factors that can be fully controlled by a cluster initiative (corporate identity mix). It means that the cluster coordinator is able to consciously build the...
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Shaping the spatial structures of post-socialist cities
PublicationThis paper deals with issues and problems associated with transformation of spatial structures of post-socialist cities. The special attention is paid to the cases of Polish cities and towns and the analysis of their evolution – from the “post-communist structures” to the “cities in the age of globalization”. In the light of this the factors influencing the spatial transformation of these are analyzed. The paper is concluded with...
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Digital structures for high-speed signal processing
PublicationThe work covers several issues of realization of digital structures for pipelined processing of real and complex signals with the use of binary arithmetic and residue arithmetic. Basic rules of performing operations in residue arithmetic are presented along with selected residue number systems for processing of complex signals and computation of convolution. Subsequently, methods of conversion of numbers from weighted systems to...
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Potentials of Water Usage in urban Neighbourhood Structures
PublicationThis paper will treat about water influence and possibility of its usage in the urban neighborhood structures (e.g. districts, real estate properties, town parts) in the context of actual regional environmental problems and according to directories determined by European targets. It is not rare yet in the basic stage of urban design that water is treated as a threat, not a chance. In result planned structures are often built,...
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Utopian Kinetic Structures and Their Impact on the Contemporary Architecture
PublicationThis paper delves into relationships between twentieth century utopian concepts of movable structures and the kinematic solutions implemented in contemporary architectural projects. The reason for conducting this study is to determine the impact of early architectural conceptions on today's solutions. This paper points out close links that stem from the imagination of artists and architects working in 1960s and 70s and the solutions...
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Factors that strengthen and weaken the identity of the cluster structures
PublicationThe main aim of this paper is the application of "identity" to the issues related to "clustering process" and particularly - to the cooperation in the clusters and the cluster initiatives. The authors distinguish these factors that have the greatest influence on the formation and maintenance of identity in mentioned networks of cooperation.
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Experimental and Numerical Study on Pounding of Structures in Series
PublicationPounding between structures in series during earthquakes may cause serious damage in the structural elements. The aim of this paper is to show the results of an experimental and numerical study that is focused on pounding between more than two structures which may be described as “structures in series”. In this study, the shaking table experiments, as well as the numerical analyses, were performed using three tower models including...
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Car-sharing: The Impact on Metropolitan Spatial Structures
PublicationMany examples from the past show that new technologies designed to solve particular problems can also create side effects generating new problems. Some unforeseen or unwanted results may influence space use and spatial structures. Car-sharing is an invention to compete with car ownership. It drastically rise efficiency of car use, reducing the number of vehicles per users. Diffusion of car-sharing is going to accelerate in the...
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Minimal surfaces and conservation laws for bidimensional structures
PublicationWe discuss conservation laws for thin structures which could be modeled as a material minimal surface, i.e., a surface with zero mean curvatures. The models of an elastic membrane and micropolar (six-parameter) shell undergoing finite deformations are considered. We show that for a minimal surface, it is possible to formulate a conservation law similar to three-dimensional non-linear elasticity. It brings us a path-independent...
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Hybrid Method Analysis of Unshielded Guiding Structures
PublicationA combination of mode matching, finite element methods and generalized impedance matrix is presented in a context of propagation problems for open guiding structures. The computational domain is divided into two regions: the first one is a circular cylinder containing whole guiding structure and the second one surrounds this artificial cylinder. The impedance matrix is calculated with the use of finite element method in the first...
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Special Issue: “Non-Destructive Testing of Structures”
PublicationThe Special Issue “Non-Destructive Testing of Structures” has been proposed to present recent developments in the field of diagnostics of structural materials and components in civil and mechanical engineering. The papers highlighted in this editorial concern various aspects of non-invasive diagnostics, including such topics as condition assessments of civil and mechanical structures and connections of structural elements, the...
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On a 3D material modelling of smart nanocomposite structures
PublicationSmart composites (SCs) are utilized in electro-mechanical systems such as actuators and energy harvesters. Typically, thin-walled components such as beams, plates, and shells are employed as structural elements to achieve the mechanical behavior desired in these composites. SCs exhibit various advanced properties, ranging from lower order phenomena like piezoelectricity and piezomagneticity, to higher order effects including flexoelectricity...
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Modal FEM Analysis of Ferrite Resonant Structures
PublicationThe finite-element method (FEM) is applied for modal analysis of ferrite-loaded spherical resonators. To improve the efficiency of the numerical calculations, the body-of-revolution (BOR) technique is utilized. Due to the frequency-dependent ferrite permeability, FEM leads to a nonlinear eigenvalue problem that is challenging to solve. To this end, Beyn’s method is proposed. The effectiveness of the proposed approach is confirmed...
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Impedance measurements of coating properties on bridge structures
PublicationPomiary impedancyjne pozwalają na prostą ocenę właściwości ochronnych powłok ochronnych i wykładzin. Pomiary stosuje się w celu porównania powłok, monitorowania ich właściwości i oceny mechanizmu działania. Metodyka jest z powodzeniem stosowana w pomiarach laboratoryjnych. Pomiary terenowe są bardziej skomplikowane ponieważ wymagają w pełni kontrolowanych komputerowo przyrządów, kontroli warunków pogodowych oraz wielu innych parametrów...
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Wave propagation in plate structures for crack detection.
PublicationW pracy przedstawiono analizę propagacji fali poprzecznej w płycie z pęknięciem. Do modelowania zagadnienia zastosowano metodę elementów spektralnych.
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Manufacturing of resistant joints by rolling for light tubular structures
PublicationKoncepcja łączenia aluminiowych elementów rurowych z zastosowaniem nagniatania plastycznego jest alternatywą do istniejących metod łączenia przez spawanie i skręcanie. W artykule prezentowane są oryginalne wyniki badań wpływu parametrów nagniatania wewnętrznego i zewnętrznego oraz różnych postaci powierzchni łączonych na wytrzymałość złącza (aluminium-aluminium) pod wpływem rozciągających sił osiowych.Badania przeprowadzono na...
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The influence of dimensional accuracy on steel structures cost calculation
PublicationW referacie przedstawiono zależność pomiędzy wartością tolerancji a kosztami wytwarzania budowlanych konstrukcji stalowych. Opisano zasady klasyfikacji tolerancji prętowych konstrukcji stalowych z uwagi na porawny montaż konstrukcji wyrażony równaiem pętli montażowej. Przedstawiono podstawy analizy i syntezy tolerancji oraz zaproponowano nową formułę optymalizacji kosztów wytwarzania. Wskazano metody rozwiązania zadania optymalizacyjnego.
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Towards automated full-wave design of microwave structures
PublicationArtykuł przedstawia problematykę automatycznego projektowania układów mikrofalowych i jego znaczenie. przedstawia stan rynku narzędzi projektowania, pojawiąjące się rozwiązania i przyszłe trendy.
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Modeling for Detection of Degraded Zones in Metallic and Composite Structures
PublicationW pracy przedstawiono przegląd metod modelowania uszkodzeń w postaci pęknięć i delaminacji wystepujących w elementach konstrukcyjnych
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Application of superelements in static analysis of thin‐walled structures
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Numerical analysis of elastic wave propagation in unbounded structures
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Remote sensing and photogrammetry techniques in diagnostics of concrete structures
PublicationRecently laser scanning technologies become widely used in many areas of the modern economy. In the following paper authors show a potential spectrum of use Terrestrial Laser Scanning (TLS) in diagnostics of reinforced concrete elements. Based on modes of failure analysis of reinforcement concrete beam authors describe downsides and advantages of adaptation of terrestrial laser scanning to this purpose, moreover reveal under which...
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3D polypyrrole structures as a sensing material for glucose detection
PublicationIn this work, 3D polypyrrole (PPy) structures as material for glucose detection is proposed. Polypyrrole was electrochemically polymerized on platinum screen-printed electrode from an aqueous solution of lithium perchlorate and pyrrole. The growth mechanism of such PPy structures was studied by ex-situ scanning electron microscopy. Preliminary studies show that studied here PPy film is a good candidate as a sensing material for...
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Probabilistic Methods in Reliability Assessment of Engineering Lightweight Structures
PublicationThe paper considers the probability-based analysis of structural safety measures. Two different numerical examples of representative lightweight structures are considered – a submerged truss tower supporting an offshore platform, and an overhead power line support truss tower. On the basis of these examples, the importance of a motivated selection of analysis method and a proper choice of the number of important variables is shown....
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Performance-Driven Surrogate Modeling of High-Frequency Structures
PublicationThe development of modern high-frequency structures, including microwave and antenna components, heavily relies on full-wave electromagnetic (EM) simulation models. Notwithstanding, EM-driven design entails considerable computational expenses. This is especially troublesome when solving tasks that require massive EM analyzes, parametric optimization and uncertainty quantification be-ing representative examples. The employment of...
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Wave transmission across surface interfaces in lattice structures
PublicationWithin the lattice dynamics formulation, we present an exact solution for anti-plane surface waves in a square lattice strip with a surface row of material particles of two types separated by a linear interface. The considered problem is a discrete analog of an elastic half-space with surface stresses modelled through the simplified Gurtin–Murdoch model, where we have an interfacial line separating areas with different surface...
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Chemical structures and physical properties of cured segmental polyurethanes
PublicationPrzedmiotem badań były poliuretany (PUR) segmentowe otrzymywane w dwuetapowej syntezie oligomerycznego α,ω-dihydroksy(adypinianu etylenowo-butylenowego) oraz dwóch różnych aromatycznych diizocyjanianów: 4,4'-diizocyjanianu difenylenometanu (MDI) albo MDI modyfikowanego diizocyjanianem karbodiimidu. Na etapie przedłużania łańcucha, oprócz typowo używanego do tego celu 1,4-butanodiolu, stosowano triol - 1,3-dihydroksy-2-(hydroksymetyleno)propan...
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The impact of material degradation on the resistance and reliability of truss structures
PublicationThe paper analyses limit load-carrying capacity and buckling load of truss towers used to support high voltage power lines. The analysed typical structure was subjected to characteristic loads and their combinations. The results were applied to assess structural resistance with regard to steel corrosion in the long-term operation. The extent of structural deterioration was assessed due to Young's modulus decrement in the course...
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Bacterial Community Structures in Freshwater Polar Environments of Svalbard
PublicationTwo thirds of Svalbard archipelago islands in the High Arctic are permanently covered with glacial ice and snow. Polar bacterial communities in the southern part of Svalbard were characterized using an amplicon sequencing approach. A total of 52,928 pyrosequencing reads were analyzed in order to reveal bacterial community structures in stream and lake surface water samples from the Fuglebekken and Revvatnet...
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Application of gpr method in diagnostics of reinforced concrete structures
PublicationThis paper presents an application of the ground penetration method (GPR) for diagnostics of reinforced concrete structures. In situ measurements were conducted for three civil engineering structures: the ground floor structure, the abutment of the railway viaduct and the concrete well. The dual polarized ground penetrating radar with the antenna operating at a center frequency of 2 GHz was used for GPR surveys. Three different...
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FIReWORK: FIR Filters Hardware Structures Auto-Generator
PublicationThe paper presents application called FIReWORK, that allows for automatic creation of the VHDL hardware structures of FIR filters. Automat- ically generated specialized hardware solutions dedicated to the FPGA and ASIC are commonly known as Intellectual Property Cores. The essential fu- ture of the application is easy initialization of FIR filter parameters in GUI, and then automatically design, calculate and generate the IP Core...
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Preparation and X-ray structures of selected aminium thiosulfates
PublicationVarious types of aminium thiosulfates (1–6), including hydrates and mixed salts, have been obtained by the reaction of ammonium thiosulfate with amines. Tertbutylamine, cyclo-hexylamine and 1,6-diaminohexane gave crystals of (t-BuNH3)2S2O3·H2O (1), (c-C6H11NH3)2S2O3 (3) and {(NH4)2(H3NC6H12NH3)(S2O3)2} (6), respectively, which were investigated by X-ray structural analysis. Extensive hydrogen bonding of the N-H…O and N-H…S type...