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Search results for: LAMELLAR STRUCTURES
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Resonant Frequencies in the Open Microstrip Structures Placed on Curved Surfaces
PublicationThe paper presents the research on open microstrip structures placed on curved surfaces such as cylindrical, elliptical or spherical. The numerical analysis of investigated structures is based on expansion of electric and magnetic fields into suitable function series. Utilizing the continuity conditions the boundary problem is formulated which is solved with the use of method of moments. The investigated structures find application...
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Numerical analysis of the carpentry joints applied in the traditional wooden structures
PublicationThe paper concerns the numerical analysis of the carpentry joints made from spruce wood. The material parameters of the wood have been calculated on the basis of nine independent material constants (an orthotropic material). The contact zone between the individual elements of the connection has been determined using Contact Tables in the MSC.Marc software. Five types of carpentry joints have been analyzed. The main aim of the research...
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Simulation-driven design of compact ultra-wideband antenna structures
PublicationPurpose–The purpose of this paper is to investigate strategies and algorithms for expedited designoptimization and explicit size reduction of compact ultra-wideband (UWB) antennas.Design/methodology/approach–Formulation of the compact antenna design problem aiming atexplicit size reduction while maintaining acceptable electrical performance is presented. Algorithmicframeworks are described suitable for handling various design situations...
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Reshaping of Coastlines as the Beginning of Urban Structures Changes in North Poland
PublicationThis article discusses the problem of strategies concerning the processes of re-shaping the Baltic Sea southern coastline applied recently in North Poland. The undertaken research is an attempt to identify the relationship between the modifications of coastline forms and the positive changes of urban structures. It can be seen that these modifications are needed because of the problems of existing shoreline erosion. It can be also...
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CFGFRPT Piles with a Circular Cross-Section and their Application in Offshore Structures
PublicationThe possibilities of using concrete piles in a polymer composite reinforced with glass fibres in offshore facilities were shown. Laboratory tests of CFGFRPT type piles compressed axially and in eccentric compression for the analysis of CFGFRPT piles were used. Methods of analysis of dynamic systems for mathematical modelling of the displacement of the hammer in the pile driving process were applied. The possibilities of combining...
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Assembly of 1D Granular Structures from Sulfonated Polystyrene Microparticles
PublicationBeing able to systematically modify the electric properties of nano- and microparticles opens up new possibilities for the bottom-up fabrication of advanced materials such as the fabrication of one-dimensional (1D) colloidal and granular materials. Fabricating 1D structures from individual particles offers plenty of applications ranging from electronic sensors and photovoltaics to artificial flagella for hydrodynamic propulsion....
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From structures to landscapes – towards re-conceptualization of the urban condition
PublicationThis paper presents an original approach towards the phenomena of re-naturalization of cities and indicates its possible consequences for the urban design and planning strategies. It focuses on the ongoing shift “from structures to landscapes” in understanding urban conditions. While modern architecture introduced geomet-ric compositions against the background of nature, early modern theories of architects and sociologists started...
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Modulated crystal structures - periodicity in more than three dimensions
PublicationThe initial definition of a crystal was that it is an object with flat faces. When diffraction studies were developed it turned out that crystal consists of a highly ordered particles and it is possible to isolate a small unique part of their structure - a unit cell - and the definition has been changed to rely on this fact. Nowadays by a crystal we mean any solid having an essentially discrete diffraction diagram. It is because...
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Influence of pitting corrosion on strength of steel ships and offshore structures
PublicationPraca dotyczy wpływu korozji wżerowej na własności mechaniczne stali o zwykłej i podwyższonej wytrzymałości oraz na wytrzymałość stalowych konstrukcji przy obciążeniach statycznych i quasi- statycznych. Artykuł oparty jest głównie na japońskich publikacjach. W próbie rozciągania, korozja wżerowa obniża nieznacznie obciążenie odpowiadające granicy plastyczności Re(nieznacznie) i wytrzymałości na rozciąganie Rm (silniej, redukuje...
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Syntheses and structures of the first terminal phosphanylphosphido complexes of molybdenum(IV)
PublicationThe reactions of R2P-P(SiMe3)Li (R = tBu, iPr2N) with [Cp2MoCl2] yield terminal phosphanylphosphido complexes formally via the insertion of the phosphinidene P-atom into the C - H bond of a cyclopentadienyl ring and the migration of the hydrogen atom or SiMe3 moiety to the molybdenum centre. Solid state structures of [Cp(C5H4P-PtBu2)MoH], [Cp(C5H4P-PtBu2)Mo(SiMe3)] and [Cp{C5H4P-P(NiPr2)2}Mo(SiMe3)] were established by single crystal...
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Tolerance Optimization of Antenna Structures by Means of Response Feature Surrogates
PublicationFabrication tolerances and other types of uncertainties, e.g., the lack of precise knowledge of material parameters, have detrimental effects on electrical and field performance of antenna systems. In the case of input characteristics these are particularly noticeable for narrow- and multi-band antennas where deviations of geometry parameters from their nominal values lead to frequency shifts of the operating frequency bands. Improving...
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Crystal structures of the DsbG disulfide isomerase reveal an unstable disulfide
PublicationDsb proteins control the formation and rearrangement of disulfide bonds during the folding of secreted and membrane proteins in bacteria. DsbG, a member of this family, has disulfide bond isomerase and chaperone activity. Here, we present two crystal structures of DsbG at 1.7- and 2.0-Angstrom resolution that are meant to represent the reduced and oxidized forms, respectively. The oxidized structure, however, reveals a mixture...
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Three-dimensional Weyl topology in one-dimensional photonic structures
PublicationTopological features, in particular distinct band intersections known as nodal rings, usually requiring three-dimensional structures, have now been demonstrated experimentally in an elegantly simple one-dimensional photonic crystal.
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Shape and force control of cable structures with minimal actuators and actuation
PublicationShape adjustment and stress control can be considered as one of the effective parameters in prestressed cable structures since such structures are widely constructed nowadays due to their characteristics. The assembly errors and applied loads hugely affect the cables’ nodal positions and stress due to their delicacy. The former could disturb the shape, which affects the appearance and the function of the structure. In contrast,...
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Synthesis and Characterization of Poly(zwitterionic) Structures for Energy Conversion and Storage
PublicationZwitterions are unique class of molecules that possess two functional groups bearing electric charges, one positive and second negative. This setup results in peculiar properties such as high water retention and anti-fouling capability. Therefore, zwitterionic coatings and gels are commonly applied in e.g. biosensing and bioelectronic devices. Despite those applications, there are other perspectives for zwitterionic materials....
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On geometry parameterization for simulation-driven design closure of antenna structures
PublicationFull-wave electromagnetic (EM) simulation tools have become ubiquitous in antenna design, especially final tuning of geometry parameters. From the reliability standpoint, the recommended realization of EM-driven design is through rigorous numerical optimization. It is a challenging endeavor with the major issues related to the high computational cost of the process, but also the necessity of handling several objectives and constraints...
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Predicting the seismic collapse capacity of adjacent structures prone to pounding
PublicationIn crowded cities, many structures are often constructed in a very close vicinity; therefore, during severe earthquakes, pounding phenomenon occurs due to out-of-phase vibrations of adjacent structures. In this study, pounding of adjacent structures is investigated up to the occurrence of total collapse. The novelty of this study is performing incremental dynamic analyses to compute the seismic collapse capacities of both pounding...
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On the non-linear dynamics of torus-shaped and cylindrical shell structures
PublicationIn this study, the non-linear dynamic analysis of torus-shaped and cylindrical shell-like structures has been studied. The applied material is assumed as the functionally graded material (FGM). The structures are considered to be used for important machines such as wind turbines. The effects of some environmental factors on the analysis like temperature and humidity have been considered. The strain field has been calculated in...
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The Impact of Contemporary Technology on Shell Structures: Material and Light Solutions
PublicationWith the development of technology and the materials used, shell structures have developed into more complex forms. This article is a comparison between contemporary and historical shell structures. The change is an effect of the evolution in the design process that is the result of parametric design thinking. The study aims to investigate the impact of new technologies on the architectural form of shell structures. Was there any...
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Flexomagneticity in buckled shear deformable hard-magnetic soft structures
PublicationThis research work performs the first time exploring and addressing the flexomagnetic property in a shear deformable piezomagnetic structure. The strain gradient reveals flexomagneticity in a magnetization phenomenon of structures regardless of their atomic lattice is symmetrical or asymmetrical. It is assumed that a synchronous converse magnetization couples both piezomagnetic and flexomagnetic features into the material structure....
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Concrete-filled FRP tubular members in marine and bridge structures
PublicationConcrete core of the concrete-filled tubes (CFTs) with circular cross-section is in the case of an axial compression subjected to a spatial state of compressive stresses. This state leads to enhancement in the concrete strength. The enhancement is utilized in Eurocode 4 design procedures for CFSTs (i.e. CFTs with tube made of steel). The structural design of CFFTs (i.e. CFTs with tube made of Fibre Reinforced Polymer - FRP) is...
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Increasing the lifetime of engineering structures through the use of composite laggings
PublicationThe use of composite laggings prevents concrete (chemical and biological) corrosion. Columns coated with composite or reinforced composite are more resistant to negative environmental impact on concrete or steel. The mechanical properties of the reinforced casing also cause that these types of columns are more resistant to lateral forces. The applied casing limits carbonization of concrete and cyclical freezing and thawing with...
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Frequency-Based Regularization for Improved Reliability Optimization of Antenna Structures
PublicationThe paper proposes a modified formulation of antenna parameter tuning problem. The main ingredient of the presented approach is a frequency-based regularization. It allows for smoothening the functional landscape of the assumed cost function, defined to encode the prescribed design specifications. The regularization is implemented as a special penalty term complementing the primary objective and enforcing the alignment of the antenna...
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Cryptography and Communications-Discrete-Structures Boolean Functions and Sequences
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Gradevnski Materijiali I Konstrukcije-Building Materials and Structures
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Age-structured population model of cell survival
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Method of lines for physiologically structured models with diffusion
PublicationWe deal with a size-structured model with diffusion. Partial differential equations are approximated by a large system of ordinary differential equations. Due to a maximum principle for this approximation method its solutions preserve positivity and boundedness. We formulate theorems on stability of the method of lines and provide suitable numerical experiments.
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Rothe’s method for physiologically structured models with diffusion
PublicationWe consider structured population models with diffusion and dynamic boundary conditions. The respective approximation, called Rothe’s method, produces positive and exponentially bounded solutions. Its solutions converge to the exact solution of the original PDE.
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Algorithms and Data Structures Symposium (was Workshop on Algorithms and Data Structures)
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Marcin Kujawa dr hab. inż.
PeopleI have graduated from the Faculty of Civil Engineering, Gdańsk University of Technology (https://pg.edu.pl/en) in 1999. I received my M.Sc. degree in civil engineering structures with specialization in bridge structures. Next, in 2007, I received my doctoral degree in technical sciences under the supervision of professor Czesław Szymczak (Scopus Author ID: 6603993146) at the Faculty of Civil Engineering, Gdańsk University of Technology....
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Pore structure of carbons coated on ceramic particles
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Local structure in Zn1−xMnxS: EXAFS study
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Editorial: Advances in geochemistry and macromolecular structure of coal
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Study of the atomic structure and morphology of the Pt3Co nanocatalyst
PublicationThe local structure and chemical disorder of a commercially available Pt3Co nanocatalyst supported on high surface area carbon were investigated. High-quality XAFS spectra were collected at the ELETTRA synchrotron XAFS 11.1 beamline. XAFS spectra analysis have been performed accounting for the reduction of the coordination number and degeneracy of three-body configurations, resulting from transmission electron microscopy (TEM)...
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Visible light photoactivity and structure of doped TiO2
PublicationOmówiono strukturą i właściwości TiO2 domieszkowanego siarką, węglem oraz borem. Aktywność fotokatalityczna zbadano w reakcji degradacji fenolu pod wpływem światła z zakresu widzialnego (l > 400 nm). Aktywność fotokatalizatorów odniesiono do ich właściwości takich jak powierzchnia właściwa, struktura krystaliczna oraz charakter chemiczny domieszki. Stwierdzono, że fotokatalizatory o najwyższej aktywności mają strukturę anatazu...
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On the electronic structure of methyl butyrate and methyl valerate
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Module structure in Conley theory with some applications
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Insight into the oligomeric structure of PORA from A. thaliana
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Synthesis and structure analysis of ferrocene‐containing pseudopeptides
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1.21 Computation of Structure, Dynamics, and Thermodynamics of Proteins
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Advanced Macromodel Matrix Structure Cloning for FDTD
PublicationWe propose an improved macromodel-based techniquefor efficient analysis of the structures based on PhotonicCrystals (PhC). The technique involves a new structure of thecoupling matrix and advanced cloning of not only the macromodel matrices, but also the coupling matrices SE and SH.The method allows one to shorten considerably the preprocessingtime, the RAM usage and also the iterating speed of performingFDTD. With this...
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Electronic structure of multiwall boron nitride nanotubes
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Laser Scanning of a Soil-Shell Bridge Structure
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Characteristics and structure of starch isolated from triticale
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The structure of liquid lead: EXAFS and MD studies
PublicationPraca poświecona jest analizie widm XAFS zmierzonych na krawędzi L3dla ciekłego ołowiu. W analizie strukturalnej EXAFS zastosowano podejście GNXAS. Przetestowano kilka modeli strukturalnych, zarówno numerycznych (MD-DLE, MD-TB), jak i tych otrzymanych doświadczalnie (ND, XRD) i ostatecznie zrekonstruowano pierwszy pik w parowej funkcji rozkładu, g(r). Zweryfikowano wcześniejsze doniesienia o obserwownym za pomocą metody XAFS gwałtownym...
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Structure and properties of polyamides-epoxidized elastomers blends
PublicationBadano mieszaniny poliamidów alifatycznych (PA6, PA 66, PA 12) zawierające do 15% wag. epoksydowanego elastomeru (statystycznego kopolimeru butadien - styren lub liniowego kopolimeru blokowego styren - butadien - styren). Stwierdzono, że właściwości mechaniczne badanych układów znacząco zależą od czasu mieszania. Oddziaływania w mieszaninach badano poprzez zmiany temepratury zeszklenia. Najbardziej korzystne, ze względu na polepszenie...
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The lifecycle of a digital historical document: structure and content.
PublicationZaproponowno model cyklu wytwarzania dokumentu cyfrowego z papierowych oryginałów pisanych na maszynie i przedstawiono opracowany przez autorów i wdrożony w środowisku Państwowego Muzeum Stutthof w Sztutowie zestaw narzędziowy DOW do automatycznej ekstrakcji treści dokumentu. Istotę nowej metodologii, opracowanej w ramach projektu 5PR UE IST-33441 MEMORIAL, jest wykorzystanie informacji semantycznej w procesach segmentacji tła,...
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Numerical modeling of wave-seabed-structure interaction.
PublicationPraca doktorska przedstawia propozycję nowoczesnego rozwiązania obciążeń hydraulicznych przy uwzględnieniu nieliniowych oddziaływań pomiędzy falą wodną, przepuszczalnym dnem i porowatą konstrukcją morską. Nabrzeże pionowe, falochron podwodny i falochron kompozytowy były obiektem eksperymentów numerycznych, których wyniki były weryfikowane przy użyciu wyników laboratoryjnych (niszczących i nieniszczących). Krótki przegląd bieżącej...
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A 3-dB coupler with UC-PBG structure
PublicationPrzedstawiono nową konstrukcję sprzęgacza z liniami paskowymi sprzężonymi szerokim bokiem oraz zmodyfikowaną warstwą metalizacji masy. Modyfikacja metalizacji polega na periodycznym wytrawieniu dwuwymiarowej struktury szczelin, nazywanej strukturą uniplanarnej zwartej przerwy fotonicznej (UC-PBG: Uniplanar Compact Photonic BandGap). Potwierdzono przewidywane wcześniej zjawisko spowolnienia fali oraz powiększenia wielkości sprzężenia...
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A complete example of experience konowledge structure on XML
PublicationPrzedstawiono kompletny przykład reprezentacji struktury wiedzy w języku XML. Omówiono cztery podstawowe składniki tej reprezentacji: dane, funkcje, ograniczenia i zasady.