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Search results for: POLY(BUTYLENE SUCCINATE), PRESSURE-INDUCED FLOW, MECHANICAL PROPERTIES, CRYSTALLIZATION, HEAT RESISTANCE
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Flow structure, heat transfer and scaling analysis in the case of thermo-magnetic convection in a differentially heated cylindrical enclosure
PublicationThe experimental, numerical and scaling analysis in the case of thermo-magnetic convection in a thermosyphon-like enclosure filled with a paramagnetic fluid is presented. Visualization of temperature field together with the numerical simulation gave an information about the flow structure, which indicated “finger-like” structures of hot and cold streams advecting each other. Their number depended on the Rayleigh number and also...
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Static and Dynamic Mechanical Properties of 3D Printed ABS as a Function of Raster Angle
PublicationDue to the rapid growth of 3D printing popularity, including fused deposition modeling (FDM), as one of the most common technologies, the proper understanding of the process and influence of its parameters on resulting products is crucial for its development. One of the most crucial parameters of FDM printing is the raster angle and mutual arrangement of the following filament layers. Presented research work aims to evaluate different...
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Archives of Civil and Mechanical Engineering
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Identification of the mechanical properties of the skin by electromechanical impedance analysis of resonant piezoelectric actuator
PublicationThis paper is devoted to the analysis and verification of developed piezoelectric sensor/actuator for measuring the mechanical properties of soft tissues, especially human skin. The key element of the measurement structure is an electromechanical system that uses both the reverse piezoelectric effect (vibration generation – stimulation of the tissues in the appropriate frequency range) and direct piezoelectric effect (system response...
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Improved finite element method for flow, heat and solute transport of Prandtl liquid via heated plate
PublicationIn the current study, a vertical, 3D-heated plate is used to replicate the generation of heat energy and concentration into Prandtl liquid. We discuss how Dufour and Soret theories relate to the equations for concentration and energy. In order to see how efectively particles, interact with heat and a solvent, hybrid nanoparticles are used. It does away with the phenomena of viscous dissipation and changing magnetic felds. The motivation...
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Window frame integrable air recuperation minichannel/minigap heat exchanger
PublicationThis article describes an evaluation of mini heat exchangers operation as a decentralized mechanical ventilation system with recuperative heat recovery that can be integrated into the window frame. The relatively small yet efficient air recuperation system allows for retrofitting existing buildings by reducing the overall energy consumption and thus the CO2 emissions. The proposed design, unlike existing systems, is easy to scale...
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Pressure in charge. Neglected parameter in hydrothermal synthesis turns out to be crucial for electrochemical properties of ammonium vanadates
PublicationAmmonium vanadates are of great interest as they exhibit unusual electrical and sensory properties.(NH4)2V6O16and (NH4)2V10O25$8H2O with various morphology were obtained in the hydrothermalsynthesis under controlled temperature and pressure. It was shown, that the pure (NH4)2V10O25$8H2Owas obtained under 50 bar of initial pressure, whereas lower pressure lead to the mixture of twocompounds. The influence of the pressure was studied...
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Blood Pressure Estimation Based on Blood Flow, ECG and Respiratory Signals Using Recurrent Neural Networks
PublicationThe estimation of systolic and diastolic blood pressure using artificial neural network is considered in the paper. The blood pressure values are estimated using pulse arrival time, and additionally RR intervals of ECG signal together with respiration signal. A single layer recurrent neural network with hyperbolic tangent activation function was used. The average blood pressure estimation error for the data obtained from 21 subjects...
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Changes in bacterial cells induced by high pressure at subzero temperature
PublicationW publikacji przedstawiono wyniki badań dotyczące zmian jakie zachodzą w komórkach bakterii Escherichia coli po działaniu wysokiego ciśnienia w ujemnej temperaturze. Stwierdzono, że w wyniku działania ciśnienia 193 MPa zachodzącą zmiany w błonie cytoplazmatycznej i ścianie komórkowej bakterii. W tych warunkach następowała prawie całkowita utrata wewnątrzkomórkowego ATP z komórek badanych szczepów znajdujących się w fazie logarytmicznej....
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Wave-induced pore pressure oscillations in sandy seabed sediments
PublicationPracę poświęcono zagadnieniu wywoływania cyklicznych oscylacji ciśnieniacieczy porowej w piaszczystym gruncie dna morskiego w wyniku oddziaływania progresywnego falowania powierzchniowego. Dokonano szerokiego przeglądu i analizy istniejących teorii ciśnień cieczy porowej z punktu widzenia skom- plikowania opisu matematycznego zachowania się ośrodka wodno-gruntowego. Wyprowadzono dwuwymiarowe rozwiązanie analityczne i...
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Determination of mechanical properties of Ti13Nb13Zr cubes made with STL technology subjected to uniaxial compression
Open Research DataThe aim of the study was to determine the mechanical properties of Ti13Nb13Zr cubes made with STL technology (3D printing). The experiments were carried out on the Hung Ta universal test machine HT-2402. Cubes with the initial dimensions of 10x10x10 mm were subjected to compression by increasing force to over 80 kN. In various experiments, the angle...
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Consideration of the safety of bungee jumping in relation to mechanical properties of the instalation based on a jump accident in Gdynia
PublicationThis paper considers a bungee jumping accident that took place in July 2019 in Gdynia, Poland. The authors conducted an investigation to determine the cause of the bungee rope failure. It was based on mechanical tests concerning the strength of the rope as well as the calculation of the force induced in the rope during the jump. Based on the theoretical and experimental results, the rope safety factor was estimated. It appeared...
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Curing characteristics, mechanical properties and morphology of butyl rubber filled with ground tire rubber (GTR)
PublicationThe results on testing application of ground tire rubber (GTR), as potential filler for butyl rubber, are pre- sented. The GTR content variation, within the range of 10–90 phr, was studied with respect to the vulcanization process, static mechanical properties (tensile strength, elongation-at-break, hardness and resilience), dynamic mechanical properties and the morphology of the obtained vulcanizates. Butyl rubber was characterized...
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Investigation on thermal changes of mechanical properties of textile fabric of National Stadium in Warsaw roof
PublicationSubject of the research is investigation of mechanical properties of technical fabric Précontraint 1202 S2 used for construction of the mobile part of roof of National Stadium in Warsaw. The research has been focused on fabric behavior in low temperature conditions. The main question which had to be answer has been: is it save to open and close the roof or keep the roof in the close position in winter conditions?
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Experimental study on the effect of selected sterilization methods on mechanical properties of polylactide FFF specimens
PublicationPurpose: Biodegradable polymers are widely used in personalized medical devices or scaffolds for tissue engineering. The manufacturing process should be finished with sterilization procedure. However, it is not clear how the different sterilization methods have an impact on the mechanical strength of the three-dimensional (3D)-printed parts, such as bone models or personalized mechanical devices. This paper aims to present the...
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Blowing Kinetics, Pressure Resistance, Thermal Stability, and Relaxation of the Amorphous Phase of the PET Container in the SBM Process with Hot and Cold Mold. Part II: Statistical Analysis and Interpretation of Tests
PublicationThe technology of filling drinks without preservatives (such as fresh juices, iced tea drinks, and vitaminized drinks) is carried out using hot filling. Mainly due to the production costs and lower carbon footprint, polyethylene terephthalate (PET) bottles are increasingly used in this technology. In this paper, the main aim is to describe and interpret the results of statistical analysis of the influence of the temperature of...
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Modelling of two-component turbulent mass and heat transfer in air-fed pressurised suits
PublicationIn this paper the modelling of an important industrial problem is addressed, which involves the two-component turbulent flow with heat transfer that takes place inside protective clothing. The geometry of the flow boundaries is reconstructed in a CAD system from photogrammetry scan data. The overall model is sufficiently realistic to allow, after validation, design improvements to be tested. Those presented here allow the reduction...
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Anna Danuta Dettlaff dr inż.
PeopleShe received her Master of Science degree in engineering with honours in 2013 at the Gdańsk University of Technology at the Department of Analytical Chemistry. In 2013-2017, she was a PhD student in the field of Chemical Technology at Faculty of Chemistry. Her doctoral dissertation was entitled “Nanocomposites based on conducting polymer and carbon materials for supercapacitor application”. In 2015, she was doing a three-month...
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Effect of ground tire rubber on structural, mechanical and thermal properties of flexible polyurethane foams
PublicationFlexible polyurethane foams were modified with two kinds of ground tire rubber, untreated and thermo-mechanically reclaimed. A reclamation process was performed in auto-thermal conditions, which reduced the cost of the process and decreased the environmental impact of devulcanization (e.g., emission of gases). The reclamation process was carried out in a continuous manner using a co-rotating twin screw extruder. The foams were...
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Increasing the conductivity of V2O5-TeO2 glass by crystallization: structure and charge transfer studies
PublicationIn the present paper, V 2 O 5 -TeO 2 glass was prepared by the melt-quenching technique. Crystallization of glass with a vanadium content higher than 35%mol results in an increase in electrical conductivity by a few orders of magnitude and a decrease in activation energy from ~0.40 to ~0.12 eV. In this work, a critical review of existing charge transfer models was presented on the example of V 2 O 5 -TeO 2 glass and glass–ceramics....
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Mechanical Properties of Twisted Carbon Nanotube Bundles with Carbon Linkers from Molecular Dynamics Simulations
PublicationThe manufacturing of high-modulus, high-strength fibers is of paramount importance for real-world, high-end applications. In this respect, carbon nanotubes represent the ideal candidates for realizing such fibers. However, their remarkable mechanical performance is difficult to bring up to the macroscale, due to the low load transfer within the fiber. A strategy to increase such load transfer is the introduction of chemical linkers...
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Effect of slag coal ash and foamed glass on the mechanical properties of two-stage concrete
PublicationTwo-stage concrete (TSC) is known by various names such as colcrete, Polcrete, preplaced aggregate concrete and prepacked concrete. It is different from traditional concrete in two fundamental ways, namely method of construction and mix proportion. Two-stage concrete (TSC) is defined as firstly, coarse aggregates are placed into the formwork and grout is applied to fill in the between coarse aggregate particles voids. Secondly,...
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Experimental investigation on straight and u-bend double tube heat exchanger with active and passive enhancement methods
PublicationAuthors in this work want to demonstrate the possibility to increase the heat transfer efficiency by using simple wire coil inserts to create turbulent flow in the boundary layer as well as air blowing into the annulus of the pipe. In the study, Wilson plot approach was applied in order to estimate heat transfer coefficients for all heat exchanger (HX) configurations. The study focuses on experimental values of heat transfer coefficient...
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Mechanical properties of two-stage concrete modified by silica fume
PublicationAbstract. Two-stage concretes, despite the fact that they have proven themselves in various types of construction, have not been studied to the same extent as traditional heavy concretes. Therefore, the article developed the composition of frame concrete with various additives in the composition of the cement-sand mortar. A comparison of the mechanical characteristics of the developed compositions with the addition of silica fume...
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Thermal properties of poly(vinyl chloride)/polyurethane blends
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Synthesis and properties of UV-curable poly(imideurethane) acrylates.
PublicationOtrzymano światłoczułe poli(imidouretano) akrylany (PIUA) które użyte zostały do wytwarzania światłoczułych kompozycji z dodatkiem reaktywnych rozcieńczalników i różnych fotoinicjatorów. Uzyskane z nich cienkie warstwy polimerowe ulegały usieciowaniu pod działaniem światłaUV w ciągu 10-30 sek. W badaniach fotolitograficznych uzyskano z ich użyciem ścieżki izolacyjne o rozdzielczości 10 mikrometrów. Usieciowane PIUA scharakteryzowano...
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Microstructure, mechanical properties, and flame retardancy of nanoclay-incorporated polyurethane flexible foam composites
PublicationThe present work seeks to investigate microstructure, mechanical properties, and flame retardancy of polyurethane/nanoclay flexible foam composites. In this regard, we prepared various nanocomposites with and without nanoclay and observed the resulting morphologies to correlate them with the other corresponding characteristics. The results provided support for the fact that tensile strength and compression set will increase with...
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The Effect of Welding Conditions on Mechanical Properties of Superduplex Stainless Steel Welded Joints
PublicationThe tests results of superduplex stainless steel welded joints made with a different heat input, using automatic submerged arc welding (SAW) and semi-automatic flux-cored arc welding (FCAW) have been presented. Metallographic examinations, the measurements of the ferrite content, the width of the heat affected zone (HAZ) and the hardness of the welds in characteristic areas have been performed. Significant differences in the amount of...
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The mechanical properties and bactericidal degradation effectiveness of tannic acid-based thin films for wound care
PublicationThe surface area is the most important aspect when considering the interactions between a material and the surrounding environment. Chitosan (CTS) and tannic acid (TA) were previously successfully tested by us to obtain thin films to serve as wound dressings or food packaging materials. However, surface properties as well as the antimicrobial activity of the material were not considered. They are important if the material is likely...
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The resistance of S235JR steel to cavitation erosion
PublicationThe erosion resistance of S235JR steel to flow cavitation was investigated. In order to understand an influence of steel properties and cavitation intensities on the degradation mechanisms, low-carbon S235JR steel was tested in the as-received state and after thermal treatment (annealing) under four different flow velocities. Annealing decreased steel hardness, which made S235JR steel less resistant to cavitation erosion. The performed...
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Management of low-temperature heat source by ORC aided by additional heat source
PublicationThe presented work is aimed at utilisation of waste heat in the manner to produce electricity in ORC installation. Therefore the precondition of the study was to use the waste heat available in the form of a stream of hot water at 90°C. Such low enthalpy heat source is rather insufficient to produce a good quality vapour to feed the ORC turbine. That was the incentive to search for the ways of increasing the temperature of the...
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Experimental investigation of heat transfer enhancement in straight and U-bend double-pipe heat exchanger with wire insert
PublicationIn this paper, the possibility of heat transfer enhancement in the U-bend exchanger was presented. Experimental research has been carried out for four individual heat exchanger constructions i.e. plain tube in tube, turbulized tube in tube, plain U-bend and U-bend with turbulator. Also, heat transfer experiments for various boundary conditions were performed to obtain reference values. In case of U-bend exchanger with and without...
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Influence of rhamnolipids and ionic cross-linking conditions on the mechanical properties of alginate hydrogels as a model bacterial biofilm
PublicationThe literature indicates the existence of a relationship between rhamnolipids and bacterial biofilm, as well as the ability of selected bacteria to produce rhamnolipids and alginate. However, the influence of biosurfactant molecules on the mechanical properties of biofilms are still not fully understood. The aim of this research is to determine the effect of rhamnolipids concentration, CaCl2 concentration, and ionic cross-linking...
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Analysis of Turbulent Flow Measurements in a Flume with Induced Upward Seepage
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The contribution of blood-flow-induced conductivity changes to measured impedance
PublicationW pracy rozwazane sa zmiany przewodnosci zachodzace w anizotropowym osrodku i ich wplyw na mierzona rezystancje. Uzyskano to za pomoca rozszerzenia wzoru Geselowizta na przypadki anizotropowe. Wykazano, ze tylko te skladowe zmian przewodnosci wplywaja na mierzona rezystancje, dla ktorych odpowiadajacy im skladnik pola eklektrycznego byl niezerowy.Wyniki te zastosowanu do zmian rezystywnosci wywolanych zmiananmi przewodnosci plynacej...
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Mechanical properties of polyester reinforced PVC coated fabric subjected to biaxial loading of creep type
PublicationThe goal of the current study is to analyze the basic mechanical properties of the architec-tural fabric VALMEX, which is a composite material built of reinforcing polyester thread families and both sides PVC coated. The material was firstly subjected to biaxial loading of creep type for about 48 hours. The stress levels of the creep loading in two main or-thogonal directions of the fabric (commonly called the warp and fill directions)...
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Investigation of Mechanical and Microstructural Properties of Welded Specimens of AA6061-T6 Alloy with Friction Stir Welding and Parallel Friction Stir Welding Methods
PublicationThe present study investigates the effect of two parameters of process type and tool offset on tensile, microhardness, and microstructure properties of AA6061-T6 aluminum alloy joints. Three methods of Friction Stir Welding (FSW), Advancing Parallel-Friction Stir Welding (AP-FSW), and Retreating Parallel-Friction Stir Welding (RP-FSW) were used. In addition, four modes of 0.5, 1, 1.5, and 2 mm of tool offset were used in two welding...
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Ship model resistance - KCS
Open Research DataShip model instantaneous resistance, velocity, pitch and heave measured data for a KCS built and tested in the towing tank of the Faculty of Mechanical Engineering and Ship Technology of Gdansk University of Technology under regular head waves.
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A novel approach for processing CaAlSiON glass-ceramics by spark plasma sintering: Mechanical and electrical properties
PublicationLithium containing glassy materials can be used as solid electrolytes or electrode materials for lithium-ion batteries due to their high energy density. Conventional melt-quenched Ca11Al14Si16O49N10 glass powder containing 24 e/o N, doped with Li-ions (1, 3, and 6 wt. %) and sintered by spark plasma sintering technique (SPS) was studied. The benefits of using SPS to produce glass-ceramics are rapid heating rates compared to conventional...
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NUMERICAL SIMULATIONS OF GAP FLOW ABOVE ROTATING DISK
PublicationA rotating disk can be considered a basic configuration for the investigati ons of the impact of various conditions on the flow through the clearance between the s hrouded turbine blade and the casing. Numerical calculations using Fine/Turbo Numeca were conducted to examine the influence of the rotational velocity and the pressure differ ence across the disk on the flow conditions, especially the mass flow through the clearance....
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A novel in vivo approach to assess strains of the human abdominal wall under known intraabdominal pressure
PublicationThe study concerns mechanical behaviour of a living human abdominal wall. A better mechanical understanding of a human abdominal wall and recognition of its material properties is required to find mechanically compatible surgical meshes to significantly improve the treatment of ventral hernias. A non-invasive methodology, based on in vivo optical measurements is proposed to determine strains of abdominal wall corresponding to...
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Hydraulic resistance analyses of selected elements of the prototype Stirling engine
PublicationThe paper presents the results of simulation tests of hydraulic resistance and temperature distribution of the prototype Stirling alpha engine supplied with waste heat. The following elements were analyzed: heater, regenerator and cooler. The engine uses compressed air as a working gas. Analyses were carried out for three working pressure values and different engine speeds. The work was carried out in order to optimize the configuration...
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Investigation of Wood Flour Size, Aspect Ratios, and Injection Molding Temperature on Mechanical Properties of Wood Flour/Polyethylene Composites
PublicationIn the present research, wood flour reinforced polyethylene polymer composites with a coupling agent were prepared by injection molding. The effects of wood flour size, aspect ratios, and mold injection temperature on the composites’ mechanical properties were investigated. For the preparation of the polymer composites, five different formulations were created. The mechanical properties including tensile strength and the modulus,...
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Mechanical Properties of Aluminium Bracket Strengthening
PublicationThe aim of the research is laboratory investigation of aluminium brackets employed to fasten lightweight curtain walls to building facilities. Tensile loads perpendicular to end plates (vertical) were applied here. The author focused on the solutions intended to increase the load-carrying capacity of aluminium brackets applying the plain washer form A (DIN 125; ISO 7089), plain washer with an outer diameter about 3d (DIN 9021;...
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Mechanical Properties of Human Abdominal Fascia
PublicationW pracy przedstawiono wyniki identyfikacji modułu sprężystosci i współczynnika Poissona próbek powięzi ściany brzucha człowieka, którą przeprowadzono na podstawie testów jednoosiowego rozciągania.
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Experimental investigations on heat transfer enhancement in shell coil heat exchanger with VARIABLE Baffles GEOMETRY
PublicationThe paper presents the possibility of using passive intensification of heat transfer in the form of baffles to increase the energy efficiency of the shell and coil heat exchanger. The experiment was carried out by using a modular coil heat exchanger in the form of an electric heater. Water was used as a working fluid with constant thermal-flow parameters at the inlet of the module. It should be noted that experiments were made...
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High-density Polyethylene - Expanded Perlite Composites: Structural Oriented Analysis of Mechanical and Thermomechanical Properties
PublicationAs part of this work, research was carried out on the effect of the addition of expanded perlite (PR) on the mechanical and thermomechanical properties of high-density polyethylene (PE) composites. Composites containing from 1 to 10 wt% of the inorganic filler were produced. Polyethylene-based composites manufactured by twin-screw extrusion and formed in the compression molding process were subjected to mechanical, thermomechanical,...
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Full scale measurements of pressure field induced on the quay wall by bow thrusters – indirect method for seabed velocities monitoring
PublicationThe paper presents the results of full-scale experimental investigation of loads generated on the quay wall by bow thrusters during unberthing of a self-manoeuvring vessel. The presented research allowed for the comparison of the measurements results with generally accepted empirical prediction methods and confirmed the utility of the developed measuring setup for the on-line monitoring of jet induced loads. The conclusions from the...
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Cross-Linking, Morphology, and Physico-Mechanical Properties of GTR/SBS Blends: Dicumyl Peroxide vs. Sulfur System
PublicationIn this work, ground tire rubber and styrene–butadiene block copolymer (GTR/SBS) blends at the ratio of 50/50 wt%, with the application of four different SBS copolymer grades (linear and radial) and two types of cross-linking agent (a sulfur-based system and dicumyl peroxide), were prepared by melt compounding. The rheological and cross-linking behavior, physico-mechanical parameters (i.e., tensile properties, abrasion resistance,...
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Study on Microstructure and Mechanical Properties of Laser Welded Dissimilar Joint of P91 Steel and INCOLOY 800HT Nickel Alloy
PublicationThis investigation attempts to explore the weld characteristics of a laser welded dissimilar joint of ferritic/martensitic 9Cr-1Mo-V-Nb (P91) steel and Incoloy 800HT austenitic nickel alloy. This dissimilar joint is essential in power generating nuclear and thermal plants operating at 600–650 °C. In such critical operating conditions, it is essential for a dissimilar joint to preserve its characteristics and be free from any kind...