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A spline-based FE approach to modelling of high frequency dynamics of 1-D structures
PublicationIn this paper a computational methodology leading to the development of a new class of FEs, based on the application of continuous and smooth approximation polynomials, being splines, has been presented. Application of the splines as appropriately defined piecewise elemental shape functions led the authors to the formulation of a new approach for FEM, named as spFEM, where contrary to the well-known NURBS approach, the boundaries...
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Accurate Modeling of Antenna Structures by Means of Domain Confinement and Pyramidal Deep Neural Networks
PublicationThe importance of surrogate modeling techniques has been gradually increasing in the design of antenna structures over the recent years. Perhaps the most important reason is a high cost of full-wave electromagnetic (EM) analysis of antenna systems. Although imperative in ensuring evaluation reliability, it entails considerable computational expenses. These are especially pronounced when carrying out EM-driven design tasks such...
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Optimum number of actuators to minimize the cross-sectional area of prestressable cable and truss structures
PublicationThis paper describes a new computational method for determining the optimum number of actuators to design the optimal and economic cross-sectional area of pin-jointed assemblies based on the conventional force method. The most active members are selected to be prestressed to redistribute stress in the whole structure, resulting in regulating the internal force of bars that face high stress. Reducing stress in critical members allows...
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Machine learning-based seismic fragility and seismic vulnerability assessment of reinforced concrete structures
PublicationMany studies have been performed to put quantifying uncertainties into the seismic risk assessment of reinforced concrete (RC) buildings. This paper provides a risk-assessment support tool for purpose of retrofitting and potential design strategies of RC buildings. Machine Learning (ML) algorithms were developed in Python software by innovative methods of hyperparameter optimization, such as halving search, grid search, random...
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Optimal reshaping and stress controlling of double-layer spherical structures under vertical loadings
PublicationOptimal reshaping and stress controlling of double-layer spherical structures under vertical loadings
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FEM-based wave propagation modelling for SHM: Certain numerical issues in 1D structures
PublicationThe numerical modelling of structural elements is an important aspect of modern diagnostic systems. However, the process of numerical implementation requires advanced levels of consideration of multiple aspects. Important issues of that process are the positive and negative aspects of solution applied methods. Therefore the aim of this article is to familiarise the reader with the most important aspects related to the process of...
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Hybrid Finite Element Method Development for Offshore Structures’ Calculation with the Implementation of Industry Standards
PublicationIn the design process of offshore steel structures, it is typical to employ commercial calculation codes in which simulation and evaluation of results are performed on the basis of the available standards (e.g. API, DNV, Lloyds). The modeling and solution rely on finite element methods and cover the simulation of the structure’s properties along with the influence of the marine environment – sea currents, wave and wind loading,...
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Reduced-Cost Design Optimization of High-Frequency Structures Using Adaptive Jacobian Updates
PublicationElectromagnetic (EM) analysis is the primary tool utilized in the design of high-frequency structures. In vast majority of cases, simpler models (e.g., equivalent networks or analytical ones) are either not available or lack accuracy: they can only be used to yield initial designs that need to be further tuned. Consequently, EM-driven adjustment of geometry and/or material parameters of microwave and antenna components is a necessary...
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A New Adaptive Method for the Extraction of Steel Design Structures from an Integrated Point Cloud
PublicationThe continuous and intensive development of measurement technologies for reality modelling with appropriate data processing algorithms is currently being observed. The most popular methods include remote sensing techniques based on reflected-light digital cameras, and on active methods in which the device emits a beam. This research paper presents the process of data integration from terrestrial laser scanning (TLS) and image data...
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Improved Modeling of Microwave Structures Using Performance-Driven Fully-Connected Regression Surrogate
PublicationFast replacement models (or surrogates) have been widely applied in the recent years to accelerate simulation-driven design procedures in microwave engineering. The fundamental reason is a considerable—and often prohibitive—CPU cost of massive full-wave electromagnetic (EM) analyses related to solving common tasks such as parametric optimization or uncertainty quantification. The most popular class of surrogates are data-driven...
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Expedited Yield-Driven Design of High-Frequency Structures by Kriging Surrogates in Confined Domains
PublicationUncertainty quantification is an important aspect of engineering design, also pertaining to the development and performance evaluation of high-frequency structures systems. Manufacturing tolerances as well as other types of uncertainties, related to material parameters (e.g., substrate permittivity) or operating conditions (e.g., bending) may affect the characteristics of antennas or microwave devices. For example, in the case...
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Magnetic and structural phase transition in Ni50Mn35.5In14.5 ribbon
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Interpretation of Structural Parameters for Models with Spatial Autoregression
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Influence of structural organization of silicas on interfacial phenomena
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Synthesis and structural investigation of N-acyl selenophosphoramides
PublicationN-acylowane amidy kwasu O,O-neopentylidenomonoselenofosforowego, w zależności od podstawnika na atomie azotu, krystalizują jako konformery zawierające selen w pozycji ekwatorialnej bądź aksjalnej. Wyniki tych eksperymentów wyjaśniono działaniem efektu anomerycznego.
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Cointegration and how it works for structural health monitoring
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Lattice Dynamics and Structural Phase Transitions in Eu2O3
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Analysis and synthesis of structural system dimensional deviations
PublicationBłedne zasady określania dopuszczalnych odchyłek wymiarowych stalowych elementów konstrukcyjnych lub wręcz ich brak często powodują trudności w czasie montażu konstrukcji. W każdym układzie konstrukcyjnym można wyróżnić tzw. Koordynacyjne Wymiary Montażowe (KWM). Odchyłki wymiarowe (tolerancje) KWM decydują o zachowaniu poprawnej geometrii ustroju budowlanego po jego zamontowaniu na placu budowy. KWM tworzą zamknięte ciągi wymiarowe,...
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Synthesen, Strukturen und Reaktionsverhalten von Metallalkoxiden
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New achievements in nanotechnologies: structural materials and biomaterials
PublicationThe examples of nanomaterials, specific technologies for their fabrication, and the application of nanomaterials in technology and medicine are described.
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Structural and electronic properties of diamond-composed heterostructures
PublicationDiamond is a promising material for 21st century electronics due to its high thermal and electronic conductivity, biocompatibility, chemical stability, high wear resistance, and possibility of doping. However, the semiconductor properties of diamond, especially free-standing films, have not been fully explored. Nor have their integration with polymers and fragile materials and their applications as electronic components. In this...
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Structural optimization of microjet array cooling system
PublicationThe single phase heat transfer from an upward facing, horizontal copper surface to arrays of impinging water jets was experimentally investigated. Experimental configuration allows for a free-surface unconfined jets flow. Square nozzles 50 × 100 μm arranged in four different geometries were used. Additionally, for the set of two jets array geometry was varied by adjusting the nozzle to nozzle distance. The area averaged heat transfer...
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Polynomial Chaos Expansion in Bio- and Structural Mechanics
PublicationThis thesis presents a probabilistic approach to modelling the mechanics of materials and structures where the modelled performance is influenced by uncertainty in the input parameters. The work is interdisciplinary and the methods described are applied to medical and civil engineering problems. The motivation for this work was the necessity of mechanics-based approaches in the modelling and simulation of implants used in the repair...
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Structural Health Monitoring System for Suspension Footbridge
PublicationThe article presents the structural health monitoring (SHM) system installed in a footbridge in Radom. The main reason for the need for fitting of such a system was failed acceptance tests of the bridge. While under a dynamic load consisting of a group of 12 pedestrians jumping on the bridge, the bridge developed vibration during which acceleration of the deck of up to 4.5 m/s2 was recorded. Such behavior of the footbridge causes...
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Electrical and structural properties of Nb-doped SrTiO3
PublicationNiobium-doped strontium titanate synthesized via conventional solid-state reaction has been studied. Influence of niobium content on the lattice parameters and electrical conductivity has been reported. Various reduction conditions have been investigated. For samples reduced in hydrogen at 1400°C, a transition from thermally activated to metallic behavior has been observed. Maximum electrical conductivity (ca. 55 Scm−1 at 650°C)...
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On structural physical approximations and entanglement breaking maps
PublicationVery recently, a conjecture saying that the so-called structural physical approximations (SPAs) to optimal positive maps (optimal entanglement witnesses) give entanglement breaking (EB) maps (separable states) has been posed (Korbicz et al 2008 Phys. Rev. A 78 062105). The main purpose of this contribution is to explore this subject. First, we extend the set of entanglement witnesses supporting the conjecture. Then, we ask whether...
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Polynomial Chaos Expansion in Bio-and Structural Mechanics
PublicationThis monograph presents a probabilistic approach to modelling the mechanics of materials and structures where the modelled performance is influenced by uncertainty in the input parameters. The work is interdisciplinary and the methods described are applied to medical and civil engineering problems. The motivation for this work was the necessity of mechanics-based approaches in the modelling and simulation of implants used in the...
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Engineering Structures and Technologies
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STEEL AND COMPOSITE STRUCTURES
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ACTA CRYSTALLOGRAPHICA SECTION E-STRUCTURE REPORTS ONLINE
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ACTA CRYSTALLOGRAPHICA SECTION C-CRYSTAL STRUCTURE COMMUNICATIONS
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BIOCHIMICA ET BIOPHYSICA ACTA-GENE STRUCTURE AND EXPRESSION
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Gold nanocubic structures agglomeration when put on conductive surfaces
Open Research DataThis dataset contains Dynamic EIS results obtained for the gold electrodes with non-functionalized gold nanocubes (AuNC) deposited at its surface. The deposition was the following: 2 uL of the solvent containing CTAB as the surfactant was put on the electrode and dried, the same procedure was applied 5 times. Afterward, the electrode was immersed in...
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Gold nanocubic structures agglomeration when put on conductive surfaces
Open Research DataThis dataset contains SEM images of gold nanocubes (AuNC), which were deposited at the conductive Si wafer surface and dried. The deposition method, the solvent used and AuNC concentration have a significant influence on the homogeneous distribution and their agglomeration at the surface, further influencing the electrochemical characteristics of the...
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Gold nanocubic structures agglomeration when put on conductive surfaces
Open Research DataThis dataset contains SEM images of gold nanocubes (AuNC), which were deposited at the conductive Si wafer surface and dried. The deposition method, the solvent used and AuNC concentration have a significant influence on the homogeneous distribution and their agglomeration at the surface, further influencing the electrochemical characteristics of the...
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Gold nanocubic structures agglomeration when put on conductive surfaces
Open Research DataThis dataset contains SEM images of gold nanocubes (AuNC), which were deposited at the conductive Si wafer surface and dried. The deposition method, the solvent used and AuNC concentration have a significant influence on the homogeneous distribution and their agglomeration at the surface, further influencing the electrochemical characteristics of the...
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Gold nanocubic structures agglomeration when put on conductive surfaces
Open Research DataThis dataset contains Dynamic EIS results obtained for the gold electrodes with non-functionalized gold nanocubes (AuNC) deposited at its surface. The deposition was the following: 2 uL of the solvent containing CTAB as the surfactant was put on the electrode and dried, the same procedure was applied 5 times. Afterward, the electrode was immersed in...
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Global dynamics in a stage-structured discrete-time population model with harvesting
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Local ordering of nano-structured Pt probed by multiple-scattering XAFS
PublicationW pracy przedstawiono wyniki analizy MS EXAFS krystalicznej platyny i nanostruktur platyny (klastry o rozmiarach od 1nm do 7nm). Rezultaty analizy masowej platyny (uwzględniające rozkłady dwu i trój-ciałowe) są zgodne z wcześniejszymi danymi strukturalnymi i wibracyjnymi i stały się podstawą do realistycznej analizy EXAFS nanocząstek Pt realizownej w połączeniu z wynikami pomiarów TEM, SEM i XRD. Badaniom poddano nanocząstki Pt...
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Capturing semantics of semi-structured data using partial-order trees
PublicationW artykule zaprezentowano nowe podejście do problemu klasyfikacji danych semistrukturalnych. Kryteria klasyfikacji bazują na strukturze danych (zwanej typem danych) oraz na ich usytuowaniu w grafir danych (zwanym rolą danych). Zastosowano model OEM (Object Exchange Model) do reprezentacji nazy danych semistrukturalnych. Bazując na tej reprezentacji, definiuje się typy i role obiektów semistrukturalnych i organizuje się je w struktury...
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Electrochemical behavior of a composite material containing 3D-structured diatom biosilica
Publication3D-structured diatom biosilica mixed with conducting carbon black was investigated as an active electrode material for lithium-ion batteries. Diatom biosilica was obtained by cultivation of the selected diatom species under laboratory conditions. Several instrumental techniques (XRD, FTIR, Raman, SEM-EDX, TGA) were used to characterize the physicochemical properties of applied biosilica. It was evidenced that the prepared new composite...
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Nitrogen mass balance and mathematical model of a Structured- Bed Reactor (SBRRIA)
PublicationAn up-flow structured-bed reactor subjected to recirculation and intermittent aeration (SBRRIA) was operated under varying influent conditions. The influent COD/N ratio was adjusted by maintaining a stable organic loading rate (average of 1.07 kgCOD m-3 d-1) and changing the nitrogen loading rate from 0.1 to 0.4 kg N m-3. Therefore, three different COD/N ratios were tested: 9.7±1 (Scenario 1); 7.6±1 (Scenario 2) and 2.9±1 (Scenario...
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X-RAY DIFFRACTION STUDY OF BISMUTH LAYER-STRUCTURED MULTIFERROIC CERAMICS
PublicationGoal of the present research was to apply a solid state reaction route to fabricate bismuth layer-structured multiferroic ceramics described with the formula Bi5FeTi3O15 and reveal the influence of processing conditions on its crystal structure and phase composition. Simple oxide powders Bi2O3, TiO2 and Fe2O3 were used to fabricate Aurivillius-type bismuth layer-structured ferroelectrics. Pressureless sintering in ambient air was...
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Maciej Niedostatkiewicz dr hab. inż.
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Acta Crystallographica Section D-Biological Crystallography
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International Journal for Computational Civil and Structural Engineering
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Acta Crystallographica Section C-Structural Chemistry
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Acta Crystallographica Section D-Structural Biology
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International Journal for Computational Civil and Structural Engineering
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International Journal of Structural and Civil Engineering Research
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