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Motor bearing diagnostics performed by means of laser vibrometer
PublikacjaDamage of bearings is the most common cause of failures in squirrel-cage induction motors. That is why the issues connected with diagnostics of bearings are so important. The equipment employed for bearing diagnostics usually makes use of vibrations as the criterion for technical condition of the bearings. This paper presents exemplary results of the research conducted on bearings with artificially introduced damage. A scanning...
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Determination of Changes in Viscosity of Hydrogel Depending on Shear Rates
PublikacjaThe datasets entitled Determination of changes in viscosity of hydrogel depending on shear rate contain the results of viscosity measurements using a Brookfield viscometer, with different kinds of spindles and shear rates. The data allowed the used hydrogel preparations to be characterised and their functional parameters, as substances modifying the rheology of thickeners and determining the effect of shear rate on the viscosity...
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New empirical correlations for the viscosity of selected organic phase change materials
PublikacjaAlthough there are many methods and instruments for measuring viscosity, it is still difficult to determine a reliable value of the dynamic viscosity of complex chemicals such as paraffins and fatty acids. This is due to the complex and heterogeneous structure of these compounds in the case of commercial products. On the other hand, the measuring instrument should be selected very carefully, including its measuring principle and...
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Rheological characteristics of oligomeric semiproducts gained via chemical degradation of polyurethane foam using crude glycerin in the presence of different catalysts
PublikacjaPolyurethane (PU) recycling is a topic of growing interest due to the increasing amount of polyurethane waste. The main purpose of polyurethane chemical recycling is to recover the starting polyol. In this study, a method of polyurethane thermochemical recycling, glycerolysis by means of crude glycerin, is proposed. This work presents a comparative study of commercial catalysts used in order to accelerate the decomposition process,...
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Modyfikacja chemiczna poliuretanów przy użyciu glikolizatów
PublikacjaCelem pracy było zbadanie możliwości wykorzystania gikolizatów o masach cząsteczkowych od 200 do 1000 jako substancji modyfikujących właściwości poliuretanów. Glikolizaty otrzymywano w reakcji odpadowej pianki poliuretanowej z 1,3-propanodiolem przy różnym stosunku masowym reagentów. Otrzymane glikolizaty scharakteryzowano poprzez oznaczenie lepkości (wiskozymetrem Brookfielda), gęstości (piknometrem) oraz liczby hydroksylowej...
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A mathematical model of rheological behavior of novel bio-based isocyanate-terminated polyurethane prepolymers
PublikacjaIn this paper, the results of rheological study on isocyanate-terminated polyurethane prepolymers, containing modified soybean oil residues incorporated into the chemical structure are described. Isocyanate-terminated prepolymers were synthesized from 4,4′-diphenylmethane diisocyanate and the mixture of hydroxylated soybean oil and commercial polyether. The measurements were performed by using rotary rheometer R/S-CPS+ (Brookfield,...
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APPLICATION OF THE THEORY OF SEMI-MARKOV PROCESSES TO DETERMINE A LIMITING DISTRIBUTION OF THE PROCESS OF CHANGES OF ABILITY AND INABILITY STATES OF FUEL SUPPLY SYSTEMS IN HEAVY FUEL DIESEL ENGINES
PublikacjaThe paper presents applicability of the theory of semi-Markov processes to determine a limiting distribution of the process of changes of technical states of fuel systems for marine engines running on heavy fuel oils. The proposed study of this process includes the components of such fuel systems like: 1 - injectors, 2 - high pressure hoses, 3 - injection pumps, 4 - low pressure hoses, 5 – fine filters, 6 - coarse filters, 7 – fuel-feed...
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Application of wavelet transform in analysis of guided wave propagation signals for damage detection in a steel plate
PublikacjaThe paper presents results of experimental investigations on damage detection using guided wave propagation technique. The tested specimen was a steel plate with a defect in the form of a rectangular notch. Lamb waves were excited by a PZT actuator and sensed by a laser vibrometer. Since reflections from damage in registered signals are often masked by measurement noise, for identification of time of reflections from damage, continuous...
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Elastic wave propagation for condition assessment of steel bar embedded in mortar
PublikacjaThis study deals with experimental and numerical investigations of elastic wave propagation in steel bars partially embedded in mortar. The bars with different bonding lengths were tested. Two types of damage were considered: damage of the steel bar and damage of the mortar. Longitudinal waves were excited by a piezoelectric actuator and a vibrometer was used to non-contact measurements of velocity signals. Numerical calculations...
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Modelling of in-plane wave propagation in a plate using spectral element method and Kane-Mindlin theory with application to damage detection
PublikacjaThis paper presents results of experimental and numerical analyses of in-plane waves propagatingin a 5 mm-thick steel plate in the frequency range of 120-300 kHz. For such a thickness/frequency ratio,extensional waves reveal dispersive character. To model in-plane wave propagation taking into account thethickness-stretch effect, a novel 2D spectral element, based on the Kane-Mindlin theory, was formulated. Anapplication of in-plane...
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Wpływ glikolu na przebieg glikolizy oraz właściwości, budowę i stabilność termiczną glikolizatów i otrzymanych z ich udziałem poliuretanów
PublikacjaCelem pracy było zbadanie wpływu zastosowanych glikoli na przebieg glikolizy odpadowych pianek poliuretanowych (PUR) w procesach w których stosowano masowy nadmiar odpadu poliuretanowego w stosunku do środka glikolizującego oraz budowy i odporności termicznej poliuretanów z glikolizatów. Glikolizaty otrzymywano w reakcji odpadowej pianki poliuretanowej z glikolami o 3 - 6 atomach węgla w cząsteczce. Proces glikolizy katalizowano...
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Lamb wave propagation in a single lap adhesive joint
PublikacjaThe aim of the paper is the analysis of Lamb wave propagation in adhesive joints. The research was performed on a single lap adhesive joint of two steel plates. Two types of joints, namely an intact and with defect were considered. In experimental investigations the condition assessment of the joint was performed with the use of antisymmetric Lamb waves excited by a plate piezo actuators and measured by a laser vibrometer. Numeri-cal...
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Damage localisation in a stiffened plate structure using a propagating wave
PublikacjaThe paper presents an application of changes in propagating waves for damage detection in a stiffened aluminium plate. The experimental investigation was conducted on an aluminium plate with riveted two L-shape stiffeners. The wave has been excited with a piezoelectric transducer and measured with the Laser Scanning Doppler Vibrometer. Recorded signals were analysed using the special signal processing techniques developed for damage...
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Tereny zdegradowane w UE: skala problemu, przyczyny powstawania i zasady zrównoważonej rewitalizacji = Brownfields in the EU : Scale of the problem, reasons of generation and principles of sustainable revitalization
PublikacjaRosnąca liczba terenów zdegradowanych staje się istotnym problemem w wielu krajach na całym świecie. Celem pracy jest przedstawienie holistycznego podejścia do zarządzania terenami zdegradowanymi rozwijanego w ramach europejskiego projektu HOMBRE (Holistic Management of Brownfield Regeneration). Koncepcja koncentruje się na osiągnięciu najwyższych możliwych korzyści ekonomicznych z uwzględnieniem zasad zrównoważonego rozwoju oraz...
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Piezo 2011, Electroceramics for End-Users VI
PublikacjaThis work extends a power harvesting with using piezoelectric materials. Experimental presents the development of a piezoelectric MEMS generator which has the ability to scavenge mechanical energy of ambient vibrations from their surroundings and transform it into electrical energy that can be used in energy storage applications. Recent literature shows that piezoelectric transduction has received the most attention for vibration-to-electricity...
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Właściwości glikolizatów oraz zsyntezowanych z nich poliuretanów
PublikacjaCelem pracy było otrzymanie glikolizatów, jako półproduktów do syntezy poliuretanów. Glikolizaty otrzymywano w reakcji odpadowej miękkiej pianki poliuretanowej (PU) z glikolem butylenowym (GB) przy stosunkach GB : PU wynoszących 2:1, 1:1, 1:2, 1:5, 1:8 i 1:10. W reakcji stosowano katalizatory metaloorganiczne. Otrzymane związki scharakteryzowano poprzez oznaczenie lepkości (wiskozymetrem Brookfield'a), gęstości (piknometrem)...
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Pomiarowa analiza drgań tarcz łożyskowych silników asynchronicznych laserem skanującym SLDV
PublikacjaArtykuł przedstawia analizę pomiarową tarcz łożyskowych silników asynchronicznych badanych przy wykorzystaniu lasera skanującego SLDV (Scanning Laser Doppler Vibrometer) na przykładzie urządzenia Polytec PSV-400. Przedstawiono istotę problemu drgań wibroakustycznych małych silników asynchronicznych powszechnie spotykanych w przemyśle. Przedstawione zostały teoretyczne wyliczone reluktancyjne składowe naprężeń promieniowych oddziałowujące...
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Reshaping the Gdańsk Shipyard—The Birthplace of the Solidarity Movement. The Complexity of Adaptive Reuse in the Heritage Context
PublikacjaThe Gdańsk Shipyard—the birthplace of the Solidarity movement—is host to a unique example of a multi-layered brownfield redevelopment project, an area that is burdened by a complex history, overlapping heritage, and multiple memories. These circumstances require an integrated yet differentiated approach to the site’s heritage and make the creation of one homogeneous narration of its future impossible. At the same time, the size...
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Wybrane problemy geotechniczne na terenach zurbanizowanych na przykładzie Trójmiasta
PublikacjaWybrane, współczesne problemy geotechniczne na terenach zurbanizowanych, miejskich i poprzemysłowych na przykładzie Trójmiasta. Dwie grupy problemów związane z podłożem oraz z otoczeniem inwestycji. Problemy związane z wodą gruntową i jej przepływem, z zanieczyszczeniami oraz pozostałościami budowlanymi z przeszłości. Sąsiedztwo zabudowy i brak miejsca. Przykłady z zrealizowanych obiektów budowlanych. Europejskie Centrum Solidarności,...
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GTR/Thermoplastics Blends: How Do Interfacial Interactions Govern Processing and Physico-Mechanical Properties?
PublikacjaIn this work, GTR/thermoplastics blends (in ratio 50/50 and 75/25 wt.%) were prepared by melt-compounding in an internal mixer. During research, trans-polyoctenamer rubber (TOR), ethylene-vinyl acetate copolymer (EVA), ethylene-octene copolymer (EOC), and linear low-density polyethylene (LLDPE), were used in their thermoplastic phase. Microstructure and processing-performance property interrelationships of the studied materials...
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Damage Imaging in Lamb Wave-Based Inspection of Adhesive Joints
PublikacjaAdhesive bonding has become increasingly important in many industries. Non-destructive inspection of adhesive joints is essential for the condition assessment and maintenance of a structure containing such joints. The aim of this paper was the experimental investigation of the damage identification of a single lap adhesive joint of metal plate-like structures. Nine joints with different defects in the form of partial debonding...
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Diagnostics of induction motor bearings - possibility of measurements
PublikacjaIn induction motors damage in the elements of electromagnetic system, for example in the wiring of stator, rotor or in the magnetic circuit can appear as well as damage of mechanical parts (bearings, rotor, shaft). Bearing diagnostics is so important in supervision of motor condition, because extensive research shows that the bearings arethe elements most susceptible to damage. This paper presents the research which the author...
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Zrównoważona rewitalizacja „modelowego” terenu zdegradowanego z wykorzystaniem rozwiązań projektu Unii Europejskiej Hombre
PublikacjaRosnąca liczba terenów zdegradowanych stanowi rosnący problem wielu krajów w Europie i na świecie. Celem pracy jest przedstawienie koncepcji zrównowazonej rewitalizacji modelowego terenu zdegradowanego w oparciu o narzędzia opracowane w ramach projektu HOMBRE (VII EU PR). Koncepcja koncentruje się na osiągnięciu najwyższych możliwych zysków ekonomicznych uwzgledniając zasady zrównowazonego rozwoju i potrzeby lokalnej społeczności....
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A study on diagnosing both isotropic and orthotropic, intentionally damaged laminates
PublikacjaBeing the most detrimental mode in laminated structures, delamination initially degrades local structural strength, and lastly causes global structural failure, thus necessitating delamination identification at its incipient stages. For identification purposes, a comprehensive numerical and experimental study on delamination within both the laminated isotropic acrylic-glass and orthotropic epoxyglass plates is presented. As the...
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Damage Detection in the Wind Turbine Blade Using Root Mean Square and Experimental Modal Parameters
PublikacjaThe paper presents results of an experimental study related to a non-destructive diagnostic technique used for preliminary determination the location and size of delamination in composite coatings of wind turbine blades. The proposed method of damage detection is based on the analysis of the ten first mode shapes of bending vibrations, which correspond to displacements of rotor blades perpendicular to the rotor plane. Modal parameters...
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RMS-based damage identification in adhesive joint between concrete beam and steel plate using ultrasonic guided waves
PublikacjaAdhesive joints have numerous applications in many branches of industry, such as civil engineering, automotive, aerospace and shipbuilding. As with most structural elements, adhesive joints can experience any damage mechanism, which induces the need for diagnostic testing. Ultrasonic waves are widely used for non-destructive inspection of many structures and their elements, including adhesive joints. Guided wave propagation method...
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Impact of Large-scale urban interventions on contemporary city centers. Gdansk case study. Wpływ przedsiewzięć urbanistycznych dużej skali na centra miast. Studium przypadku Gdańska
PublikacjaLarge scale urban interventions have become a common development practice in cotemporary cities, allowing achieving rapid changes in their urban structure. They can be analyzed taking into account various perspectives. Some of them include planning and development models, transformation of brownfields and other types of distressed urban areas, as well as consequences and results of their implementation in existing urban structures....
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Hyperelastic Microcantilever AFM: Efficient Detection Mechanism Based on Principal Parametric Resonance
PublikacjaThe impetus of writing this paper is to propose an efficient detection mechanism to scan the surface profile of a micro-sample using cantilever-based atomic force microscopy (AFM), operating in non-contact mode. In order to implement this scheme, the principal parametric resonance characteristics of the resonator are employed, benefiting from the bifurcation-based sensing mechanism. It is assumed that the microcantilever is made...
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Fabrication and characterization of boron-doped nanocrystalline diamond-coated MEMS probes
PublikacjaFabrication processes of thin boron-doped nanocrystalline diamond (B-NCD) films on silicon-based micro- and nano-electromechanical structures have been investigated. Nanocrystalline boron doped -diamond (B-NCD) films were deposited using Microwave Plasma Assisted Chemical Vapour Deposition (MW PA CVD) method. The variation of B-NCD morphology, structure and optical parameters were particularly investigated. The use of truncated...
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Incidence of severe critical events in paediatric anaesthesia (APRICOT): a prospective multicentre observational study in 261 hospitals in Europe
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