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Experimental Studies of Concrete-Filled Composite Tubes under Axial Short- and Long-Term Loads
PublicationThe paper presents experimental studies on axially compressed columns made of concrete-filled glass fiber reinforced polymer (GFRP) tubes. The infill concrete was C30/37 according to Eurocode 2. The investigated composite pipes were characterized by different angles of fiber winding in relation to the longitudinal axis of the element: 20, 55 and 85 degrees. Columns of two lengths, 0.4 m and 2.0 m, were studied. The internal diameter...
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Poloxamer: A versatile tri-block copolymer for biomedical applications
PublicationPoloxamers, also called Pluronic, belong to a unique class of synthetic tri-block copolymers containing central hydrophobic chains of poly(propylene oxide) sandwiched between two hydrophilic chains of poly(ethylene oxide). Some chemical characteristics of poloxamers such as temperature-dependent self-assembly and thermo-reversible behavior along with biocompatibility and physiochemical properties make poloxamer-based biomaterials...
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Segmented bio-based polyurethane composites containing powdered cellulose obtained from novel bio-based diisocyanate mixtures
PublicationA considerable number of research works focus on the positive influence of cellulose on the properties of polymer-based composites and their wide range of application possibilities. The present work is focused on the synthesis of novel bio-based polyurethane (bio-PU) composites filled with powdered cellulose (microcellulose, MC) in an amount of 5 wt.%. Bio-PU composites were synthesized via a non-solvent prepolymer method. First,...
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Preparation and Characterization of Diamond-like Carbon Coatings for Biomedical Applications—A Review
PublicationDiamond-like carbon (DLC) films are generally used in biomedical applications, mainly because of their tribological and chemical properties that prevent the release of substrate ions, extend the life cycle of the material, and promote cell growth. The unique properties of the coating depend on the ratio of the sp3/sp2 phases, where the sp2 phase provides coatings with a low coefficient of friction and good electrical conductivity,...
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The Characteristic of Surface Layers on Austenitic Stainless SteelAfter Glow-discharge Nitriding Process.
PublicationThis paper presents investigation of surface layers. The diffusion layers were produced by using different parameters of reactive atmosphere (N2:H2). The research of the surface layers was performed using scanning electron microscope (SEM). The results of energy dispersive X-ray (EDX) analysis and X-ray diffraction (XRD) analysis are presented. Research reveals the influence of chemical constitution of reactive atmosphere on the...
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Biomechanical testing of bioactive bone cements – a comparison of the impact of modifiers: antibiotics and nanometals
PublicationApart from its bone filler and fracture stabilizing function, bone cement can be used as a carrier of bioactive substances, and such modified bone cement can protect the implant against microorganisms, treat local infections and combat bacteria introduced during the surgical procedure. In this paper, the effects of modifying antibiotics and nanosilver on the biomechanical properties of bone cement were examined. The following tests...
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Preparation and Characterization of Films Based on Disintegrated Bacterial Cellulose and Montmorillonite
PublicationThe food packaging materials from natural polymers including polysaccharides offer an ecologically important alternative to commonly used synthetic, non-biodegradable counterparts. The purpose of this work was to modify of bacterial cellulose (BC) leading to the improvement of its functional properties in terms of use as a food packaging material. Effects of disintegration of BC and addition of montmorillonite (MMT) on its water...
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Evaluating Gelatin-Based Films with Graphene Nanoparticles for Wound Healing Applications
PublicationIn this study, gelatin-based films containing graphene nanoparticles were obtained. Nanoparticles were taken from four chosen commercial graphene nanoplatelets with different surface areas, such as 150 m2/g, 300 m2/g, 500 m2/g, and 750 m2/g, obtained in different conditions. Their morphology was observed using SEM with STEM mode; porosity, Raman spectra and elemental analysis were checked; and biological properties, such as hemolysis...
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From polymer waste to potential main industrial products: Actual state of recycling and recovering
Publicationlastics have become widely used materials in everyday life due to their special properties such as durability, easy processing, light-weight and low-cost of production. However, because of their stable and non-biodegradable nature, postconsumer plastics become an issue to the environment. The growing amounts of waste are generated, as plastic products are commonly used only once before disposal. The alternatives of practical techniques...
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Theoretical and experimental analysis of guided wave propagation in plate-like structures with sinusoidal thickness variations
PublicationGuided waves have attracted significant attention for non-destructive testing (NDT) and structural health monitoring (SHM) due to their ability to travel relatively long distances without significant energy loss combined with their sensitivity to even small defects. Therefore, they are commonly used in damage detection and localization applications. The main idea of incorporating guided waves in NDT and SHM is based on processing...
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Machine learning-based seismic response and performance assessment of reinforced concrete buildings
PublicationComplexity and unpredictability nature of earthquakes makes them unique external loads that there is no unique formula used for the prediction of seismic responses. Hence, this research aims to implement the most well-known Machine Learning (ML) methods in Python software to propose a prediction model for seismic response and performance assessment of Reinforced Concrete Moment-Resisting Frames (RC MRFs). To prepare 92,400 data...
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Prediction of maximum tensile stress in plain-weave composite laminates with interacting holes via stacked machine learning algorithms: A comparative study
PublicationPlain weave composite is a long-lasting type of fabric composite that is stable enough when being handled. Open-hole composites have been widely used in industry, though they have weak structural performance and complex design processes. An extensive number of material/geometry parameters have been utilized for designing these composites, thereby an efficient computational tool is essential for that purpose. Different Machine Learning...
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Effect of austempering temperature on microstructure and cyclic deformation behaviour of multiphase low-carbon steel
PublicationThis paper examined the cyclic deformation behaviour of multiphase low-carbon steel that was subjected to austempering heat treatments at four temperatures (190 °C, 230 °C, 275 °C, and 315 °C) below the martensite start temperature (Ms = 353 °C). The tests were conducted at room temperature, under fully reversed strain-controlled conditions, with strain amplitudes in the range 0.5–1.0%. The microstructure was observed by transmission...
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Developing Methodology for Model Tests of Floating Platforms in Low -Depth Towing Tank
PublicationThe paper presents two different methods of physical modeling of semi-submersible platform mooring system for research in low depth towing tank. The tested model was made in the scale of 1:100 resembling the "Thunder Horse" platform moored in the Gulf of Mexico at a depth of 1,920 m. Its mooring system consisted of 16 semi-taut mooring lines (chain-wire-chain) spaced starshape and attached at the bottom to suction piles. The tests...
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Optimal control of 2-wheeled mobile robot at energy performance index
PublicationThe paper presents the application of the optimal control method at the energy perfor- mance index towards motion control of the 2-wheeled mobile robot. With the use of the proposed method of control the 2-wheeled mobile robot can realise effectively the desired trajectory. The problem of motion control of mobile robots is usually neglected and thus performance of the realisation of the high level control tasks is limited.
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Experimental bases for the rail track surface damage detection system
PublicationA diagnosis of rail surface is generally based on the classical method of direct assessment and track geometry measurements. Identification and qualification of inequality and damage on the surface rails is depend on the skills and experience person who conducting inspection. In times of increasing exploitation of railways, infrastructure managers decide to use systems supporting the assessment of technical condition of the railways....
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Predicting the seismic collapse capacity of adjacent SMRFs retrofitted with fluid viscous dampers in pounding condition
PublicationSevere damages of adjacent structures due to structural pounding during earthquakes have emphasized the need to use some seismic retrofit strategy to enhance the structural performance. The purpose of this paper is to study the influence of using linear and nonlinear Fluid Viscous Dampers (FVDs) on the seismic collapse capacities of adjacent structures prone to pounding and proposing modification factors to modify the median...
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Development of fragility curves in adjacent steel moment-resisting frames considering pounding effects through improved wavelet-based refined damage-sensitive feature
PublicationFragility curves present useful information related to earthquake-induced probability assessment of steel moment-resisting frames (MRFs) and determine the probability of the damage exceedance at different floor levels of MRFs. The review of the literature shows that most of the previous studies dealing with the fragility curves were based on conventional measures, such as spectral acceleration at the first mode period, peak...
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Comparative analysis of numerical models of arch-shaped steel sheet sections
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Estimation of the parameters of the discrete model of a steel–concrete composite beam
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Optimal retrofit strategy using viscous dampers between adjacent RC and SMRFs prone to earthquake‑induced pounding
PublicationNowadays, retrofitting-damaged buildings is an important challenge for engineers. Finding the optimal placement of Viscous Dampers (VDs) between adjacent structures prone to earthquake-induced pounding can help designers to implement VDs with optimizing the cost of construction and achieving higher performance levels for both structures. In this research, the optimal placement of linear and nonlinear VDs between the 3-story, 5-story,...
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An adaptive-noise Augmented Kalman Filter approach for input-state estimation in structural dynamics
PublicationThe establishment of a Digital Twin of an operating engineered system can increase the potency of Structural Health Monitoring (SHM) tools, which are then bestowed with enhanced predictive capabilities. This is particularly relevant for wind energy infrastructures, where the definition of remaining useful life is a main driver for assessing the efficacy of these systems. In order to ensure a proper representation of the physical...
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Stability analysis of cylindrical composite shells in MSC/Nastran
PublicationW pracy badane jest zastosowanie systemu MSC/NASTRAN for Windows do analizy stateczności kompozytowych powłok cylindrycznych. Przeprowadzono obliczenia dla dwóch wybranych przykładów paneli cylindrycznych poddanych równomiernemu ściskaniu w kierunku tworzącej dokonując analizy zarówno w zakresie stateczności początkowej jak i problemu geometrycznie nieliniowego w procesie przyrostowym. Otrzymane wyniki w pełni potwierdziły bogate...
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Thermal energy storage using stearic acid as PCM material
PublicationThis work presents an experimental study of thermal energy storage by use of PCM. The aim of the study was to establish the influence of different inlet temperature of heat transfer fluid (HTF) and different Reynolds number of HTF on intensity of charging process. The PCM used in this study was stearic acid and water was used as HTF. A copper helical coil mounted in cylindrical container served as a heat transfer surface.
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Predicting the seismic collapse capacity of adjacent SMRFs retrofitted with fluid viscous dampers in pounding condition
PublicationSevere damages of adjacent structures due to structural pounding during earthquakes have emphasized the need to use some seismic retrofit strategy to enhance the structural performance. The purpose of this paper is to study the influence of using linear and nonlinear Fluid Viscous Dampers (FVDs) on the seismic collapse capacities of adjacent structures prone to pounding and proposing modification factors to modify the median...
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Modelling and parameter identification of steel–concrete composite beams in 3D rigid finite element method
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Fatigue damage development in 10CrMo9-10 steel for power plant pipes in as-received state and after 280,000 h of exploitation
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Saint-Venant torsion based on strain gradient theory
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Damage identification by wavelet analysis
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Mutual hydrodynamic interaction between the operating propeller and the rudder
PublicationPraca przedstawia opis algorytmu i programu do analizy oddziaływania hydrodynamicznego pomiędzy pracującą śrubą a sterem. Algorytm jest oparty na jednoczesnym rozwiązaniu zadania brzegowego dla śruby i steru. Wyniki obliczeń obejmują rozkłady ciśnienia i zmienne siły hydrodynamiczne na śrubie i sterze oraz niestacjonarne zjawiska kawitacyne na obu obiektach. Wyniki obliczeń porównano z rezultatami badań eksperymentalnych.
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3D Form analysis of rope deformation with long towed underwater hydroacoustic antenna
PublicationArtykuł opisuje rozwiązanie zagadnienia brzegowego dla zestawu długiej liny holującej i podwodnej anteny hydroakustycznej o gęstości, tej ostatniej, nieznacznie większej od gęstości wody i małej sztywności. Znane jest tylko położenie punktu zamocowania liny do okrętu (p-kt początkowy holowanego zestawu) oraz głębokość, na której znajduje się koniec anteny. Przedstawiono analizę sił działających na holowany zestaw, ich równania...
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Damage identification by wavelet analysis
PublicationW pracy omówiono metodę identyfikacji rodzaju nieciagłości w 1 wymiarowych elementach konstrukcji wykorzystującą pomiar propagacji fali sprężystej i jej analizę metodą transformacji falkowej.
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The crucial contemporary problems of the computational methods for ship propulsor hydrodynamics
PublicationPraca przedstawia krytyczny przegląd współczesnych metod obliczeniowych stosowanych do projektowania i analizy pracy pędników okretowych. Omówiono modele linii nośnej i powierzchni nośnej, a także metody elementów brzegowych i metody RANSE oraz LES. Przedstawiono przykładowe wyniki obliczeń oraz oceniono i porównano dokładność opisywanych metod.
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A computer system for the complete design of ship propellers
PublicationPraca zawiera opis metody obliczeniowej pozwalającej na zaprojektowanie okrętowej śruby napędowej dla również obliczeniowo wyznaczonego niejednorodnego pola prędkości za kadłubem statku o znanej geometrii i parametrach ruchu. Metoda pozwala na właściwe ujęcie efektu skali i konsekwencji obecności płetwy sterowej za projektowaną śrubą.
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Assessment of ship squat in shallow water using CFD
PublicationArtykuł zawiera wstęp do problemu modelowania efektów wody ograniczonej przy użyciu komercyjnego programu Fluent opartego na metodzie elementów skończonych.
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Linear analysis of laminated multilayered plates with the application of zig-zag function
PublicationW pracy analizowany jest dwuwymiarowy model MES płyty warstwowej bazujący na teorii ścinania pierwszego rzędu, w którego sformułowaniu uwzględnione są dodatkowo efekt zig-zag oraz warunki równowagi międzywarstwowej. Zygzakowa deformacja przekroju modelowana jest poprzez wzbogacenie liniowego rozkładu przemieszczeń teorii ścinania pierwszego rzędu kawałkami ciągłą funkcją Murakami'ego. Pole przemieszczeń w prezentowanym sformułowaniu...
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Suitability of DIC and ESPI optical methods for monitoring fatigue damage development in X10CrMoVNb9-1 power engineering steel
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Effect of plasma nitriding process on the fatigue and high temperature corrosion resistance of Inconel 740H nickel alloy
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Lamb wave based structural damage detection using cointegration and fractal signal processing
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Deep learning based segmentation using full wavefield processing for delamination identification: A comparative study
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Deep learning super-resolution for the reconstruction of full wavefield of Lamb waves
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Towards homoscedastic nonlinear cointegration for structural health monitoring
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Zirconium alloyed tungsten borides synthesized by spark plasma sintering
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Research and applications of active bearings: A state-of-the-art review
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Full wavefield processing by using FCN for delamination detection
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Scale effect in shaft friction from direct shear tests
PublicationPrzeanalizowano wartości maksymalne tarcia uzyskane w aparacie bezpośredniego ścinania w kontakcie konstrukcja-grunt dla piasków kwarcowych i węglanowych oraz gładkiego i szorstkiego kontaktu. Badania przeprowadzono przy regulowanej sztywności normalnej kontaktu, przy różnej składowej normalnej naprężenia w kontakcie i różnym zagęszczeniu gruntu. Określono efekt skali jako stosunek wartości tarcia mobilizowanego na modelu do tarcia...
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Use of calibration chamber as a large triaxial apparatus
PublicationModelowanie wycinka kolumny żwirowej o wysokości 1 m w komorze kalibracyjnej. Badania przeprowadzono przy różnym naprężeniu bocznym w komorze. Kolumnę poddano obciążeniu pionowemu przy odkształceniu pionowym do 2%. Określono jej parametry wytrzymałościowe oraz moduły odkształcenia przy obciążeniu oraz w cyklach odciążenie-powtórne obciążenie.
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Statistical data of hull main parameters useful for preliminary design of SWATH ships
PublicationW artykule przedstawiono rezultaty badań dotyczących statystycznych relacji głównych parametrów projektowych kadłuba statków typu SWATH, wykonanych w oparciu o zebrane w literaturze przedmiotu dane o ponad osiemdziesięciu statkach. Zależności statystyczne przedstawiono w postaci histogramów: długości statku L, histogramów wartości stosunków długości do szerokości L/B, długości do wysokości bocznej L/H, długości pływaków do ich...
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Investigation on the edge forces in ball end milling of inclined surfaces
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Modeling of cutter displacements during ball end milling of inclined surfaces
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