Search results for: MECHANICAL DESIGN
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Flame-Retardant Polymer Materials Developed by Reactive Extrusion: Present Status and Future Perspectives
PublicationThe development of flame retardant polymer materials has two roots, one in materials design, and the other in materials processing. Over recent decades, different types and classes of flame retardant polymer materials have been commercialized to meet safety requirements in the construction, automotive, and coatings industries. In the vast majority of cases, the design and fabrication of new materials presenting low fire hazards...
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EVALUATION OF EFFECTIVENESS OF WATERJET PROPULSOR FOR A SMALL UNDERWATER VEHICLE
PublicationT he goal of the project described is to replace the existing propulsion system of a small underwater vehicle with a solution less prone to mechanical damage and ensuring a lower risk of the entanglement of fibrous objects suspended in the body of water. Four typical marine screws are utilised in the current design of the vehicle. One possible solution of the problem is the application of waterjet propulsors located...
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The basics of design and experimental tests of the commutation unit of a hydraulic satellite motor
Publicationhe article presents an analytical method to design the commutation unit in a hydraulic satellite motor. It is shown that the size of the holes feeding the working chambers and their location on the plates closing those chambers depends on the geometrical dimensions of the working mechanism. The overlap in the commutation unit depends on the rotational speed range. It is demonstrated that the geometrical dimensions of the commutation...
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Fish gelatin-nanoclay films. Part I: Effect of a kind of nanoclays and glycerol concentration on mechanical and water barrier properties of nanocomposites
PublicationThe aim of work was the improvement of the mechanical and water barrier properties of nanocomposites prepared from fish gelatin and nanoclays (5–15%), plasticized with glycerol at different concentrations. The effect of hydrophilic Cloisite Na1 and Nanomer®PGV was compared with that exerted by organically modified more hydrophobic Nanofil®2 and NanoBent ZR-1. Antimicrobial activity of nanocomposites containing hydrophobic nanoclays...
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Fate and significance of phthalates and bisphenol A in liquid by-products generated during municipal solid waste mechanical-biological pre-treatment and disposal
PublicationSamples of liquid by-products generated by municipal solid waste plants (MSWPs) were tested for the presence of phthalates (PAEs) and bisphenol A (BPA). The results indicated that the wastewater generated during mechanical (sorting unit - SU) and biological (composting unit - CU) pre-treatment (MBT) of residual (mixed) solid waste is a significant source of these compounds. The concentrations of PAEs (up to 32222 lg/L) and BPA...
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The Influence of Calcium Glycerophosphate (GPCa) Modifier on Physicochemical, Mechanical, and Biological Performance of Polyurethanes Applicable as Biomaterials for Bone Tissue Scaffolds Fabrication
PublicationIn this paper we describe the synthesis of poly(ester ether urethane)s (PEEURs) by using selected raw materials to reach a biocompatible polyurethane (PU) for biomedical applications. PEEURs were synthesized by using aliphatic 1,6-hexamethylene diisocyanate (HDI), poly(ethylene glycol) (PEG), α,ω-dihydroxy(ethylene-butylene adipate) (Polios), 1,4-butanediol (BDO) as a chain extender and calcium glycerolphosphate salt (GPCa) as...
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Dynamic mechanical properties and thermal degradation process of the compositions obtained from unsaturated poly(ester urethanes) cross-linked with styrene
PublicationW pracy przedstawiono właściwości dynamiczno-mechaniczne oraz stabilność termiczną poli(estro uretanów) sieciowanych styrenem. Badane poli(estro uretany) syntetyzowano z nienasyconych oligomeroli opartych na cis-2-buten-1,4-diolu oraz 4,4`-diizocyjanianie difenylometanu. Wyniki badań dynamicznych właściwości mechanicznych otrzymanych poliuretanów potwierdziły separację fazową uzyskanych kompozycji. W pracy przedstawiono również...
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Microstructure and Mechanical Properties of Combined GTAW and SMAW Dissimilar Welded Joints between Inconel 718 and 304L Austenitic Stainless Steel
PublicationA dissimilar welded joint of Inconel 718 and 304L austenitic stainless steel was prepared using a combined procedure with the gas tungsten arc welding and shielded metal arc welding processes by employing the Ni-based fillers: ERNiCr-3 and ENiCrFe-3. The welded joints were investigated for metallographic testing and mechanical properties, and a relationship was established between the microstructure and the resultant mechanical...
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Few Layered Oxidized h-BN as Nanofiller of Cellulose-Based Paper with Superior Antibacterial Response and Enhanced Mechanical/Thermal Performance
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Właściwości i spawalność dwufazowych stali odpornych na korozję typu duplex = Mechanical properties and weldability of duplex stainless steels
PublicationW artykule scharakteryzowano nowoczesne stale odporne na korozję o strukturze ferrytyczno- austenitycznej typu duplex podając ich skład chemiczny, strukturę, właściwości mechaniczne i odporność korozyjną. Przedstawiono podstawowe problemy, które mogą wystąpić podczas spawania tego typu stali. Omówiono przemiany fazowe w strukturze stali zachodzące pod wpływem obróbki cieplnej i cieplnych cykli spawania oraz ich wpływ na właściwości...
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Mechanical Properties, Microstructure and Surface Quality of Polypropylene Green Composites as a Function of Sunflower Husk Waste Filler Particle Size and Content
PublicationAgricultural waste is a still untapped source of materials that can, in case of proper utilization, significantly improve the sustainability of polymers and their composites. In this work, polymer composites based on isotactic polypropylene were produced incorporating ground sunflower husk in the amount of 10 wt% and 20 wt%. The work’s main objective is to evaluate how preliminary fractioning of this agricultural waste filler affects...
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Comparative X-ray diffraction and Mössbauer spectroscopy studies of BiFeO3 ceramics prepared by conventional solid-state reaction and mechanical activation
PublicationThe aim of this work was to prepare BiFeO3 by modified solid-state sintering and mechanical activation processes and to investigate the structure and hyperfine interactions of the material. X-ray diffraction and Mössbauer spectroscopy were applied as complementary methods. In the case of sintering, BiFeO3 phase was obtained from the mixture of precursors with 3 and 5 % excess of Bi2O3 during heating at 1023 K. Small amounts of...
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Mechanical and Microstructural Characterization of TIG Welded Dissimilar Joints between 304L Austenitic Stainless Steel and Incoloy 800HT Nickel Alloy
PublicationIn this article, the mechanical properties and microstructure of 304L austenitic stainless steel/Incoloy 800HT nickel alloy dissimilar welded joints are investigated. The joints were made of 21.3 mm × 7.47 mm tubes using the TIG process with the use of S Ni 6082 nickel filler metal. No welding imperfections were found and high strength properties of joints were obtained, meeting the assumed acceptance criteria of the product’s...
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Improving Output Performance of the Ultrasonic Multicell Piezoelectric Motor by Development the Multi-Rotor Structure
PublicationIn recent years, many researches have been carried out on piezoelectric multi-rotor structures. This paper describes the analysis, development and experimental process of an ultrasonic multi-cell piezoelectric motor using a multi-rotor structure. In this design, three independent cells have been integrated into a mechatronic system. Analytical model and finite element method are used for modal and dynamic analysis of the proposed...
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Fluid–Structure Interaction methods for the progressive anatomical and artificial aortic valve stenosis
PublicationCardiovascular system diseases, as aortic valve stenosis, are the main cause of mortality and morbidity among patients. There is still a room for enhancement of the diagnostic and therapeutic procedures, which will lead to improvement of the treatment. One of the remedies are the computer tools to support the medical diagnoses and prostheses design. The development of a procedure for modeling the aortic valves: anatomical tricuspid...
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Stress Monitoring System for Individuals with Autism Spectrum Disorders
PublicationIn this article, a stress monitoring system tailored for individuals with Autism Spectrum Disorders (ASD) and developed for the educational institution is presented. People with ASD face problems with effective stress management due to their high self-perceived levels of stress, poor ability to cope with it, and dificulties with the accurate detection of the source of stress. Consistently, being able to measure stress appears to...
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A Theoretical and Experimental Study of Moderate Temperature Alfa Type Stirling Engines
PublicationThe Stirling engine is a device that allows conversion of thermal energy into mechanical energy with relatively high efficiency. Existing commercial designs are mainly based on the usage of high temperature heat sources, whose availability from renewable or waste heat sources is significantly lower than that of moderate temperature sources. The paper presents the results of experimental research on a prototype alpha type Stirling...
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Design and simulation of a new prototype of piezoelectric cantilever sensor/actuator for analysis of the soft tissues properties
PublicationThis paper is devoted to a new prototype of piezoelectric cantilever transducer dedicated for the characterization of the mechanical properties of soft tissues. General description of the actuator’s structure is presented including the basic principles of the measurement. The chosen geometry of the prototype is discussed and compared with the existing one. Constitutive equations are presented for the active and passive layer of...
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Mohammad Hossein Ghaemi dr inż.
PeopleMohammad Hossein Ghaemi Mohammad Hossein Ghaemi (1967), is an Assistant Professor at the Faculty of Mechanical Engineering and Ship Technology - WIMiO (till 2020: Faculty of Ocean Engineering and Ship Technology), Department of Automatics and Marine Energy Engineering. He studied first at Tehran University, where was graduated in the field of Mechanical Engineering (Solid Mechanics). Then he received his MSc degree in the area...
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Piotr Lorens prof. dr hab. inż. arch.
PeopleProf. Piotr Lorens - PhD, DSc., urban planner. Lecturer in urban design and development and - since 2007 - Head of the Department of Urban Design and Regional Planning at the Faculty of Architecture, Gdansk University of Technology. His university activities also include coordination of the research and EU Social Fund projects. Based on these projects he was responsible for organization and coordination of the post-graduate studies...
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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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Simulation of fluid structure interaction in a novel design of high pressure axial piston pump
PublicationA novel type of an axial, piston-driven high pressure hydraulic pump with variable capacity marks a significant improvement in the area of the hydraulic machinery design. Total discharge from hydrostatic forces eliminates a need for a servomechanism, thus simplifying operation, reducing weight and introducing the possibility of the pump displacement control by computer. PWK-type pumps, invented in the Gdansk University of Technology,...
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Characterization of volatile compounds, structural, thermal and physico-mechanical properties of cross-linked polyethylene foams degraded thermo-mechanically at variable times
PublicationWaste cross-linked polyethylene foam (wXLPE) was thermo-mechanically degraded at variable time using internal batch mixer. The progress of wXLPE degradation has been investigated by using a simultaneous thermogravimetric/differential scanning calorimetry analyzer coupled with Fourier transform infrared spectroscopy, swelling measurements, tensile tests and scanning electron microscopy. Volatile organic compounds generated during...
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Chemical-Assisted Mechanical Lapping of Thin Boron-Doped Diamond Films: A Fast Route Toward High Electrochemical Performance for Sensing Devices
PublicationThere is an urgent need for an effective and economically viable increase in electrochemical performance of boron-doped diamond (BDD) electrodes that are used in sensing and electrocatalytic applications. Specifically, one must take into consideration the electrode heterogeneity due to nonhomogenous boron-dopant distribution and the removal of sp2 carbon impurities saturating the electrode, without interference in material integrity....
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Polyvalent Mechanical Bacterial Lysate Administration Improves the Clinical Course of Grass Pollen–Induced Allergic Rhinitis in Children: A Randomized Controlled Trial
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Validation of odor concentration from mechanical-biological treatment piles using static chamber and wind tunnel with different wind speed values
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Late subclinical hemolysis and long-term outcomes after aortic valve replacement with On-X mechanical prostheses – a preliminary single-center report
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The Effect of Mechanical Vibration during Transport under Model Conditions on the Shelf-Life, Quality and Physico-Chemical Parameters of Four Apple Cultivars
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The Effect of Zirconium Dioxide (ZrO2) Nanoparticles Addition on the Mechanical Parameters of Polymethyl Methacrylate (PMMA): A Systematic Review and Meta-Analysis of Experimental Studies
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Recycling of Industrial Waste as Soil Binding Additives—Effects on Soil Mechanical and Hydraulic Properties during Its Stabilisation before Road Construction
PublicationTo improve the in situ soil stabilization, different chemical additives are used (ion exchange compounds, additives based on H2SO4 or vinyl polymers, and organic additives using lignosul- fonates). One interesting alternative is the production of additives from various waste materials. The extensive testing of waste-based blends with soil was performed; the mechanical (unconfined compressive strength (UCS)) and hydraulic (capillary...
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Mechanical and microstructural properties of cement pastes containing carbon nanotubes and carbon nanotube-silica core-shell structures, exposed to elevated temperature
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The impact of filler thermomechanical modifications on static and dynamic mechanical performance of flexible foamed polyurethane/ground tire rubber/zinc borate composites
PublicationThe rapid development of the automotive industry is very beneficial to many aspects of human life, but it is also a very significant environmental burden. The most straightforward impact is related to the generation of exhaust, but the management of post-consumer car parts is also a major challenge. Among them, waste tires are very burdensome due to their enormous numbers. Therefore, it is essential to develop novel, environmentally...
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Ground Tire Rubber Modified by Elastomers via Low-Temperature Extrusion Process: Physico-Mechanical Properties and Volatile Organic Emission Assessment
PublicationIn this paper, low-temperature extrusion of ground tire rubber was performed as a proecological waste tires recycling method. During this process, ground tire rubber was modified with constant content of dicumyl peroxide and a variable amount of elastomer (in the range: 2.5–15 phr). During the studies, three types of elastomers were used: styrene-butadiene rubber, styreneethylene/butylene-styrene grafted with maleic anhydride and...
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Image-based numerical modeling of the tensile deformation behavior and mechanical properties of additive manufactured Ti–6Al–4V diamond lattice structures
PublicationThis work concerns the numerical modeling of the deformation process and mechanical properties of structures obtained by the additive method laser power bed fusion (LPBF). The investigation uses diamond structures of Ti–6Al–4V titanium implantation alloy with various relative densities. To model the process of tensile deformation of the materials, geometric models were used, mapping the realistic shape of the examined structures....
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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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Focused ion beam-based microfabrication of boron-doped diamond single-crystal tip cantilevers for electrical and mechanical scanning probe microscopy
PublicationIn this paper, the fabrication process and electromechanical properties of novel atomic force microscopy probes utilising single-crystal boron-doped diamond are presented. The developed probes integrate scanning tips made of chemical vapour deposition-grown, freestanding diamond foil. The fabrication procedure was performed using nanomanipulation techniques combined with scanning electron microscopy and focused ion beam technologies....
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Hydraulic fracturing process in rocks – small-scale simulations with a novel fully coupled DEM/CFD-based thermo-hydro-mechanical approach
PublicationW artykule przedstawiono dwuwymiarową (2D) symulację numeryczną szczelinowania hydraulicznego w małej skali przeprowadzoną w próbkach skał posiadających pojedynczą szczelinę wtryskową. Wykorzystano unikalny model termo-hydro-mechaniczny (THM) w skali porów oparty na DEM/CFD do symulacji dwufazowego laminarnego przepływu płynu (wody i gazu) z przenoszeniem ciepła w nienasyconych materiałach porowatych o niskiej porowatości. Korzystając...
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Volumetric and torque efficiency of pumps during start-up in low ambient temperatures
PublicationThe volumetric, torque and total efficiency of hydraulic pumps change during start-up in low ambient temperatures, as well as in thermal shock conditions, un-til they reach the set conditions. The time to reach steady-state conditions de-pends on many parameters: ambient temperature, flow rate, fluid temperature, design of hydraulic units. The author carried out tests of hydraulic pumps in the Hydraulics Laboratory of the Faculty...
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Potential of Functionalized Polyolefins in a Sustainable Polymer Economy: Synthetic Strategies and Applications
PublicationPolymers play a crucial role in our modern life as no other material exists that is so versatile, moldable, and lightweight. Consequently, the demand for polymers will continue to grow with the human population, modernization, and technological developments. However, depleted fossil resources, increasing plastic waste production, ocean pollution, and related growing emission of greenhouse gases has led to a change in the way we...
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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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Application of Stirling Engine Type Alpha Powered by the Recovery Energy on Vessels
PublicationThe Stirling engine is a device, in which thermal energy is transformed into mechanical without a contact between the heat carrier, and the working gas closed in the engine. Mentioned feature makes this type of engine very attractive for the use of the recovery energy, taken from other heat devices. One of the potential applications of Stirling engines is the use of thermal energy generated in the ship's engine room for producing...
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30 years of treatment wetland application in poland- progress and reserch
PublicationThe experiences with design and operation of constructed wetlands in the Pommerania region during last 30 years followed by carried out investigations of treatment processes lead to the following conclusions:First applications of constructed wetlands for biological sewage treatment were made in 1984-92. The later implementations of multi-stage constructed wetlands in the individual household and local scale enable wastewater treatment...
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Simulation of fluid structure interaction in a novel design of high pressure axial piston hydraulic pump
PublicationA novel type of an axial, piston-driven high pressure hydraulic pump with variable capacity marks a significant improvement in the area of the hydraulic machinery design. Total discharge from hydrostatic forces eliminates a need for a servomechanism, thus simplifying operation, reducing weight and introducing the possibility of the pump displacement control by computer. PWK-type pumps, invented in the Gdansk University of Technology,...
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Mechatronic design o strongly nonlinear systems on a basis of three wheeled mobile platform
PublicationRemarkable grow in demand both of mobile platform operability performance and reduction of project leading time development encourage to apply modern algorithms and reliable engineering tools for the design process. The paper discusses the mechatronic design applied for the surveillance system based on the energy performance index algorithm. The exploited mechatronic techniques i.e. virtual prototyping, Hardware-In-the-Loop Simulation...
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Forced vibrations in a dynamic system that is damped by a mechanism that trans-pass through its singular position
PublicationIn the paper, vibrations of a hybrid multibody-continuous system are investigated. For all the mechanical devices, effective damping methods are crucial in the design process. To obtain it, installation of viscous dampers or elasto-viscous elements is dominant. In the paper, an alternative method is investigated. It is based on modal disparity. To describe the method briefly, when structural damping is present in continuous systems,...
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Constructing multifunctional nanofiller with reactive interface in PLA/CB-g-DOPO composites for simultaneously improving flame retardancy, electrical conductivity and mechanical properties
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Enhanced Mechanical and Electromechanical Properties of Compositionally Complex Zirconia Zr1–x(Gd1/5Pr1/5Nd1/5Sm1/5Y1/5)xO2−δ Ceramics
PublicationCompositionally complex oxides (CCOs) or high-entropy oxides (HEOs) are new multi-element oxides with unexplored physical and functional properties. In this work, we report fluorite structure derived compositionally complex zirconia with composition Zr1- x(Gd1/5Pr1/5Nd1/5Sm1/5Y1/5)xO2-δ (x = 0.1 and 0.2) synthesized in solid-state reaction route and sintered via hot pressing at 1350 °C. We explore the evolution of these oxides'...
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Ground Tire Rubber Modified by Ethylene-Vinyl Acetate Copolymer: Processing, Physico-Mechanical Properties, Volatile Organic Compounds Emission and Recycling Possibility
PublicationGround tire rubber (GTR) was reclaimed and modified with 10 phr of ethylene-vinyl acetate copolymer via low-temperature extrusion process. Processing, physico-mechanical properties, volatile organic compounds emission, and recycling possibility were investigated. In order to better understand the impact of used modifiers, their efficiency was compared with transpolyoctenamer, which is an additive that is commercially dedicated...
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Polyhydric SiO2 coating assistant to graft organophosphorus onto glass fabric for simultaneously improving flame retardancy and mechanical properties of epoxy resin composites
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Mechanical and radiation shielding properties of concrete reinforced with boron--basalt fibers using Digital Image Correlation and X--ray micro--computed tomography
PublicationThe paper presents experimental investigations of the radiation shielding, mechanical and fracture properties of concrete reinforced with 5 kg/m3 of novel basalt fibers infused with boron oxide (BBF). However, further studies concerning other dosages i.e. 1 kg/m3, 10 kg/m3, 15 kg/m3 and 20 kg/m3 are currently carried out. Experiments with neutron source revealed that addition of BBF as a dispersed concrete reinforcement could improve...