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Search results for: DEFECTED GROUND STRUCTURES
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Does Nitrogen Fertilization Affect the Secondary Structures of Gliadin Proteins in Hypoallergenic Wheat?
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The Syntheses and Crystal Structures of the First Disiloxane-1,3-dithiol and Its Cadmium Complex.
PublicationThe new silicon–sulfur compound: disiloxane-1,3-dithiol was obtained from silicon disulfide and 2,6-diisopropylphenol in a reaction catalyzed by imidazole or 4-(dimethylamino)pyridine (DMAP). Crystal structure of disiloxane–1,3-dithiol reveals a close-to-linear Si–O–Si angle and a mutual trans position of the two hydrosulfido groups. The compound forms a chelating mononuclear complex with cadmium ions.
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Influence of Spatial Structures of 316L Stainless Steel on Its Cavitation Erosion Resistance
PublicationCavitation erosion performance of modified macroscopic internal structure 316L stainless steel was investigated. The samples processed by means of SLM method were subjected to cavitation erosion test. The scanning electron microscope Philips 30/ESEM was used to examine morphology of eroded surface.
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QSAR Analysis of Selected Antimicrobial Structures Belonging to Nitro-derivatives of Heterocyclic Compounds
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Syntheses, structures and chemical properties of unsaturated oligo(alkylene-ester-ether)diols
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Evaluation of the Mechanical Parameters of Ultrasonically Welded Textile Composite Structures for Protective Footwear
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Guided wave propagation in structures. Modelling, experimental studies and application to damage detection
PublicationCelem niniejszej pracy są eksperymentalne i numeryczne analizy propagacji prowadzonych fal sprężystych w stalowych konstrukcjach prętowych, belkowych, ramowych, tarczowych i płytowych. W szczególności praca poświęcona jest: (a) modelowaniu propagacji fal z uwzględnieniem zjawiska dyspersji; (b) budowie modeli obliczeniowych w formalizmie metody elementów spektralnych; (c) eksperymentalnej weryfikacji zaproponowanych modeli; (d)...
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Recovering Sound Produced by Wind Turbine Structures Employing Video Motion Magnification
PublicationThe recordings were made with a fast video camera and with a microphone. Using fast cameras allowed for observation of the micro vibrations of the object structure. Motion-magnified video recordings of wind turbines on a wind farm were made for the purpose of building a damage prediction system. An idea was to use video to recover sound & vibrations in order to obtain a contactless diagnostic method for wind turbines. The recovered signals...
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Proceedings of the fib Symposium 2019: Concrete - Innovations in Materials, Design and Structures 2019
PublicationDesigning a concrete mix is a process of synthesizing many components, it is not a simple process and requires extensive technical knowledge. The design process itself focuses on obtaining the required strength of concrete. Very often designing a concrete mix takes into account the need to maintain the proper water-demand and frost-resistance features. The parameters that influence the concrete class most significantly are the...
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Spectral Methods for Modelling of Wave Propagation in Structures in Terms of Damage Detection—A Review
PublicationModern methods of detection and identification of structural damage direct the activities of scientific groups towards the improvement of diagnostic methods using for example the phenomenon of mechanical wave propagation. Damage detection methods that use mechanical wave propagation in structural components are extremely effective. Many different numerical approaches are used to model this phenomenon, but, due to their universal...
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Hybrid technique for the analysis of scattering from periodic structures composed of irregular objects
PublicationW pracy zaproponowano nową metodę hybrydową do badania zjawiska rozpraszania fali elektromagnetycznej na strukturach periodycznych złożonych z obiektów rozpraszających o nieregularnym kształcie. Zaprezentowana metoda została wykorzystana do badania własności nowych struktur falowych. Uzyskane wyniki numeryczne zostały zweryfikowane eksperymentalnie.
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Modeling protein structures with the coarse-grained UNRES force field in the CASP14 experiment
PublicationThe UNited RESidue (UNRES) force field was tested in the 14th Community Wide Experiment on the Critical Assessment of Techniques for Protein Structure Prediction (CASP14), in which larger oligomeric and multimeric targets were present compared to previous editions. Three prediction modes were tested (i) ab initio (the UNRES group), (ii) contact-assisted (the UNRES- contact group), and (iii) template-assisted (the UNRES-template...
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Low-strain sensor based on the flexible boron-doped diamond-polymer structures
PublicationA free-standing high boron-doped diamond nanosheet (BDDNS) has been fabricated for the development of a flexible BDDNS strain senor. High boron-doped diamond was initially grown on a tantalum substrate in a microwave plasma-assisted chemical vapor deposition method, and was then transferred to a Kapton polymer substrate to fabricate the flexible BDDNS/Kapton device. Before performing the transfer process, the thin BDDNS’s morphology...
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ECOLOGY OR ECONOMICS? THE ASPECT DETERMINING THE USE OF DISPLACEMENT PILES FOR THE FOUNDATIONS OF BRIDGE STRUCTURES
PublicationW ostatnich latach rzadko wykonuje się pale wiercone o bardzo dużych średnicach ze względu na: wymagany sprzęt, transport wydobytego urobku gruntowego, duże ilości stali zbrojeniowej. Konstrukcje inżynierskie na autostradzie A-1, na drodze ekspresowej S-7 i Obwodnicy Południowej Gdańska posadowiono na palach prefabrykowanych. Fundamenty największych mostów na autostradzie A-1 zbudowano na palach Vibro i Franki. W artykule zwrócono...
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Baseline-free debonding detection in reinforced concrete structures by elastic wave propagation
PublicationThe article presents the results of the numerical and experimental analysis concerning wave propagation in reinforced concrete (RC) beams with various extent of debonding between the steel rod and concrete cover. The main aim of the paper was to consider the unsolved research gaps, which considerably limit the application of wave-based methods in practice. The propagation of the flexural wave modes excited and registered on the...
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A review of stability problems of thin-walled structures developed at Gdańsk University of Technology
PublicationW pracy podano przegląd problemów stateczności konstrukcji cienkościennych, które były przedmiotem badań na Politechnice Gdańskiej. Przedstawiono bibliografię obejmującą 75 prace podzielone na trzy grupy tematyczne: stateczność prętów i łuków, pokrytyczne zachowanie się elemntów oraz optymalne projektowanie i analizę wrażliwości.
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Some remarks about numerical stability in nonlinear dynamics on the basic of truss structures.
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Eficient multimode mixed time-frequency domain analysis and optimization of waveguide structures.
PublicationW pracy przedstawiona jest pełnofalowa analiza i optymalizacja struktur falowodowych o zadanej topologii. Nieciągłości falowodowe analizowane są z wykorzystaniem metody FDTD-IBC oraz scharakteryzowane uogólnioną macierzą rozproszenia. Efektywność metody zilustrowana jest na przykładzie filtru falowodowego siódmego rzędu.
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Production structures and strategies supporting lean parts manufacturing: an industrial case study.
PublicationPrzedstawiono model sformalizowanego opisu wzorców możliwości wytwarzania zróżnicowanego spektrum przedmiotów oraz analizy podobieństwa ich procesów technologicznych, dla kształtowania struktur przestrzennych systemów typu gniazdowego, z uwzględnieniem paradygmatu oszczędnej produkcji. Zaproponowano algorytm grupowania przedmiotów wg określonych, w postaci ciągów znakowych, sekwencji operacji procesu technologicznego oraz kryterium...
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Eficient multimode mixed time-frequency domain analysis and optimization of waveguide structures.
PublicationW pracy przedstawiona jest pełnofalowa analiza i optymalizacja struktur falowodowych o zadanej topologii. Nieciągłości falowodowe analizowane są z wykorzystaniem metody FDTD-IBC oraz scharakteryzowane uogólnioną macierzą rozproszenia. Efektywność metody zilustrowana jest na przykładzie filtru falowodowego siódmego rzędu.
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Investigations of vortex structures in granular materials under earth pressure conditions by DEM
PublicationW artykule pokazano rozwój wirów na poziomie ziarna materiału granulowanego podczas parcia pasywnego piasku na sztywną ściankę przemieszczającą się poziomo. Obliczenia wykonano stosując metodę DEM. Przyjęto 3 różne sposoby wyznaczenia wirów i ich czestotliwości.
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Accelerated Gradient-Based Optimization of Antenna Structures Using Multi-Fidelity Simulations and Convergence-Based Model Management Scheme
PublicationThe importance of numerical optimization has been steadily growing in the design of contemporary antenna structures. The primary reason is the increasing complexity of antenna topologies, [ a typically large number of adjustable parameters that have to be simultaneously tuned. Design closure is no longer possible using traditional methods, including theoretical models or supervised parameter sweeping. To ensure reliability, optimization...
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The role of electrolysis and enzymatic hydrolysis treatment in the enhancement of the electrochemical properties of 3D-printed carbon black/poly(lactic acid) structures
PublicationAdditive manufacturing, also known as 3D printing, is beginning to play an unprecedented role in developing many applications for industrial or personalized products. The conductive composite structures require additional treatment to achieve an electroactive surface useful for electrochemical devices. In this paper, the surfaces of carbon black/poly(lactic acid) CB-PLA printouts were activated by electrolysis or enzymatic digestion...
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Recent Advances in Accelerated Multi-Objective Design of High-Frequency Structures using Knowledge-Based Constrained Modeling Approach
PublicationDesign automation, including reliable optimization of engineering systems, is of paramount importance for both academia and industry. This includes the design of high-frequency structures (antennas, microwave circuits, integrated photonic components), where the appropriate adjustment of geometry and material parameters is crucial to meet stringent performance requirements dictated by practical applications. Realistic design has...
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Aquaponics Based Artificial Biosphere Included in Architecture: From Mitigation of Negative Impacts to Positive Added Values of Urban Spatial Structures on Local, Regional and Global Scale
PublicationTechnologies may appear faster than spatial planning can afford it. Alt hough applying new technologies solve particular problems, it may also create new ones. Many negative consequences of implementing new technologies are visible a fter years or decades – they accumulate until the need of solving them. According to The Hannover Principles (McDonough & Braungart 2013) one should, by example not think about...
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Acid–base properties of 3-[2-(pyridyl)benzoxazol-5-yl]alanine derivatives in the ground and excited state. Experimental and theoretical studies
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The influence of feed rate and shear forces on the devulcanization process of ground tire rubber (GTR) conducted in a co-rotating twin screw extruder
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Low-Cost and Highly-Accurate Behavioral Modeling of Antenna Structures by Means of Knowledge-Based Domain-Constrained Deep Learning Surrogates
PublicationThe awareness and practical benefits of behavioral modeling methods have been steadily growing in the antenna engineering community over the last decade or so. Undoubtedly, the most important advantage thereof is a possibility of a dramatic reduction of computational expenses associated with computer-aided design procedures, especially those relying on full-wave electromagnetic (EM) simulations. In particular, the employment of...
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Cable-stayed cantilever structures as an expat of unique application in the construction of a building located in seismic area – an author’s project of multifunctional building in Lisbon, Portugal
PublicationThe article presents numerical simulations for the modelling of seismic impact on the structure of unique cantilever cablestayed structure with application of two methods. The Response Spectrum method, in which a spectrum of the structure's responses to an earthquake's impact is generated and the Accelerogram method, in which we generate dynamic load in the form of a diagram of the connection between acceleration and time for...
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Machine learning-based prediction of seismic limit-state capacity of steel moment-resisting frames considering soil-structure interaction
PublicationRegarding the unpredictable and complex nature of seismic excitations, there is a need for vulnerability assessment of newly constructed or existing structures. Predicting the seismic limit-state capacity of steel Moment-Resisting Frames (MRFs) can help designers to have a preliminary estimation and improve their views about the seismic performance of the designed structure. This study improved data-driven decision techniques in...
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A New Approach for Investigating the Impact of Pesticides and Nutrient Flux from Agricultural Holdings and Land-Use Structures on Baltic Sea Coastal Waters
PublicationKnowledge related to land-use management impacts on the Baltic Sea ecosystem is limited. The constant release of pollutants into water bodies has resulted in water quality degradation. Therefore, only the innovative approaches integrated with research will provide accurate solutions and methods for proper environment management and will enable understanding and prediction of the impacts of land-use in the Baltic Sea region. Modelling...
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Neuro-wavelet damage detection technique in beam, plate and shell structures with experimental validation
PublicationNiniejsza praca poświęcona jest technice diagnostyki konstrukcji bazującej na transfor-macie falkowej oraz sztucznych sieciach neuronowych (tzw. system neuro-wavelet). Zastosowanie analizy falkowej pozwala na lokalizację uszkodzeń wymagającą mini-malnej ilości danych wejściowych. W tym celu niezbędna jest tylko odpowiedź kon-strukcji pomierzona w wielu punktach. Poprawę efektywności lokalizacji zniszczeń uzyskano poprzez użycie...
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The analysis of the mechanical properties of welding joints of high-strength steels for offshore and ships structures
PublicationW artykule przedstawiono równania korelacyjne właściwości mechanicznych złaczy spawanych stali wysokiej wytrzymałości, które umożliwiają ocenę wpływu technologii spawania tych stali.W pracy zaproponowana dwa równania. Pierwsze umożliwa wstępną ocenę spawalności obecnie produkowanych stali wysokiej wytrzymałości, natomiast równania korelacyjne pozwalają obliczyć maksymalną twardość strefy wpływu ciepła materiału.
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Effect of Active Mining Impact On Properties with Engineering Structures – Forecast and Final Result Discrepancies
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Ab initio and experimental studies of polarization and polarization related fields in nitrides and nitride structures
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The K x-ray line structures of the 3d-transition metals in warm dense plasma
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Comparison of protein precipitation methods for various rat brain structures prior to proteomic analysis
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Analysis of Reliability Structures for Fire Signaling Systems in the Field of Fire Safety and Hardware Requirements
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The analysis of the mechanical properties of welding joints of high-strength steels for offshore and ships structures
PublicationW artykule przedstawiono równania korelacyjne właściwości mechanicznych złaczy spawanych stali wysokiej wytrzymałości, które umożliwiają ocenę wpływu technologii spawania tych stali. W pracy zaproponowana dwa równania. Pierwsze umożliwa wstępną ocenę spawalności obecnie produkowanych stali wysokiej wytrzymałości, natomiast równania korelacyjne pozwalają obliczyć maksymalną twardość strefy wpływu ciepła materiału.
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Local-Global Space Mapping for Rapid EM-Driven Design of Compact RF Structures
PublicationIn this work, we introduce a robust and efficient technique for rapid design of compact RF circuits. Our approach exploits two-level space mapping (SM) correction of an equivalent circuit model of the structure under design. The first SM layer (local correction) is utilized to ensure good matching between the equivalent circuit and the electromagnetic model at the component level. On the other hand, the global correction allows...
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Problems of Determination of Welding Angular Distortions of T-fillet Joints in Ship Hull Structures
PublicationShip hull structure elements are in majority joined by welding. Welding distortions can cause a lot of problems during the manufacturing process. In the literature it is proposed wide spectrum of suggestions for a correct estimation of welding deformation in particular angular deformation in the fillet welded T joint. In the work verification of selected methods is proposed basing upon of the results of the laboratory measurements....
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Creation of structures by 4, 5 and 6-year-old children, considering the conditions for the structure
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The Antibacterial and Antifungal Textile Properties Functionalized by Bimetallic Nanoparticles of Ag/Cu with Different Structures
PublicationWe reported a preparation and characterization of five kinds of impregnation solutions, containing Ag/Cu in the formof bimetallic nanoparticles (alloy and core-shell) as well as ionic species. The cotton-polyester textiles were successfully impregnated during the washing and ironing process by as-prepared solutions to have antibacterial and antifungal properties against to Escherichia coli, Staphylococcus aureus, and Candida albicans....
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Skilled-Unskilled Wage Gap Versus Evolving Trade And Labour Market Structures in the EU
PublicationThis paper proposes an alternative approach to the empirical study of wage gap between workers with different educational levels in the enlarged EU. The analysis is based on sectoral database, linking labor market statistics and trade data at the level of 12 manufacturing sectors in a group of 20 European countries: selected New Member States (NMS-5) and former EU-15 economies, in the period 1995-2005. The results of the empirical...
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Reliable EM-driven size reduction of antenna structures by means of adaptive penalty factors
PublicationMiniaturization has become of paramount importance in the design of modern antenna systems. In particular, compact size is essential for emerging application areas such as internet of things, wearable and implantable devices, 5G technology, or medical imaging. On the other hand, reduction of physical dimensions generally has a detrimental effect on antenna performance. From the perspective of numerical optimization, miniaturization...
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An Improved Method of Minimizing Tool Vibration during Boring Holes in Large-Size Structures
PublicationThe paper presents a thoroughly modified method of solving the problem of vibration suppression when boring large-diameter holes in large-size workpieces. A new approach of adjusting the rotational speed of a boring tool is proposed which concerns the selection of the spindle speed in accordance with the results of the simulation of the cutting process. This streamlined method focuses on phenomenological aspects and involves the...
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Revealing the Frank–Evans “Iceberg” Structures within the Solvation Layer around Hydrophobic Solutes
PublicationUsing computer simulations, the structural properties of solvation water of three model hydrophobic molecules, methane and two fullerenes (C60 and C80), were studied. Systems were simulated at temperatures in the range of 250−298 K. By analyzing both the local ordering of the molecules of water in the solvation layers and the structure of hydrogen bond network, it is shown that in the solvation layer of hydrophobic molecules, ordered...
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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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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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Quality increase for single-welded joints of thin-walled structures by means of simulation modelling
PublicationThe Simulation calculation module and the SolidWorks software package have helped to define the optimal shape and dimensions of single-welded joints which may serve the basis for calculating the process parameters of welding. Having compared the models with different weld cross-sections the authors have defined that the weld height and width do not significantly affect the stress concentration, and the stress concentration and...