Search results for: natural fibre, eco-friendly cement composites, reinforcement composites, sem
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The innovative approach for using pavement as a fire prevention measure in tunnels
PublicationThe paper consists of two main parts: first presents study regarding the typically used pavement structures in tunnels and the second part: the first fire trials of the poroelastic SEPOR (Safe, Eco-friendly POroelastic Road Surface) mixture which was designed to be used among other uses in tunnels. In the first part of the paper different pavement materials, such as cement concrete, asphalt concrete, stone mastic asphalt and porous...
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Biosurfactants - Biodegradability, toxicity, efficiency in comparison with synthetic surfactants
PublicationBiosurfactants are natural surface active agents produced by variety of bacteria yeast and fungi. A review of their biodegradability, toxicity and efficiency is presented in order to compare their properties with synthetic surfactants. Due to their high efficiency in many applications and environmentally friendly character we tried to apply them in oil refining process. The efficiency of biosurfactants in this application was very...
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A Method and Device for 3D Recognition of Cutting Edge Micro Geometry
PublicationA very useful method was successfully applied in the investigation of tools for machining wood and wood based composites. It allows scanning of the cutting edge micro geometry in three dimensions and reproducing it in a virtual space as a 3D surface. The application of the method opens new possibilities of studying tool wear by scanning, including the calculation of volume loss and other analysis of tool wedge geometry along and...
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Wpływ ukształtowania zbrojenia na zarysowanie i nośność żelbetowego węzła tarczowego ze wspornikiem
PublicationPraca ma charakter eksperymentalno-teoretyczny i dotyczy zagadnień związanych z żelbetowymi tarczami pracującymi w przestrzennym układzie konstrukcji budynków. Celem niniejszej dysertacji było określenie wpływu głównych parametrów jakimi są sposób ukształtowania zbrojenia i smukłość ścinania na zarysowanie i nośność żelbetowego przestrzennego węzła tarczowego ze wspornikiem. Na podstawie aktualnego stanu wiedzy, opracowano program...
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TiO 2 Co x O y composite nanotube arrays via one step electrochemical anodization for visible light–induced photocatalytic reaction
PublicationTiO2CoxOy (x = 1, y = 1 or x = 3, y = 4) composite photocatalysts have been synthesized via one step anodic anodization of TiCo alloys. The effects of the cobalt content in the alloy (5, 10 and 15 wt%), water content (2, 5 and 10%) in the electrolyte solution, and applied voltage (30, 40 and 50 V) during the anodization process on the morphology and surface properties. Additionally, the dependence of cobalt content in the nanotubes...
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Synergistic effect of nanoscale carbon black and ammonium polyphosphate on improving thermal stability and flame retardancy of polypropylene: A reactive network for strengthening carbon layer
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Na3PO4 assistant dispersion of nano-CaCO3 template to enhance electrochemical interface: N/O/P co-doped porous carbon hybrids towards high-performance flexible supercapacitors
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Magnetization enhancement in magnetite nanoparticles capped with alginic acid
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Effects of manufacturing and face /core bonding on impact damage in glass/polyester - PVC foam core sandwich panels
PublicationZbadano podatność na inicjację uszkodzeń pod wpływem spadającego obciążenia w konstrukcjach przekładkowych poliestrowo szklanych z rdzeniem z pianki PVC przy dwóch sposobach łączenia okładek z rdzeniem: przy pomocy 2 klejów proponowanych do tego celu przez ich producentów oraz czystej żywicy. Zastosowano oprzyrządowany młot spadowy , określając rozmiar zniszczeń na powierzchni próbki metodą wizualna i ultradźwiękową. Inicjacja...
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Transient response of oscillated carbon nanotubes with an internal and external damping
PublicationThe present works aims at modeling a viscoelastic nanobeam with simple boundary conditions at the two ends with the introduction of the Kelvin-Voigt viscoelasticity in a nonlocal strain gradient theory. The nanobeam lies on the visco-Pasternak matrix in which three characteristic parameters have a prominent role. A refined Timoshenko beam theory is here applied, which is only based on one unknown variable, in accordance with the...
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Geometrically nonlinear FEM analysis of FGM shells based on neutral physical surface approach in 6-parameter shell theory
PublicationThe paper presents the formulation of the elastic constitutive law for functionally graded materials (FGM) on the grounds of nonlinear 6-parameter shell theory with the 6th parameter being the drilling degree of freedom. The material law is derived by through-the-thickness integration of the Cosserat plane stress equations. The constitutive equations are formulated with respect to the neutral physical surface. The influence of...
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Polyurethane/ground tire rubber composite foams based on polyglycerol: processing, mechanical and thermal properties
PublicationDuring the synthesis of rigid polyurethane foams, petrochemical polyol was substituted with polyglycerol, the product of thermo-catalytic polycondensation of waste glycerol, resulting from biodiesel production. Two types of ground tire rubbers, untreated and thermo-mechanically reclaimed, were used to obtain ‘‘green’’ polyurethane-polyglycerol composite foams. Samples were prepared by a single-step method for the ratio of NCO/OH...
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Mechanical properties of Precontraint 1202 S2 based on uniaxial tensile and creep tests
PublicationThe purpose of the paper is the estimation of the polyvinyl chloride – polyester-coated fabric (Precontraint 1202 S2) mechanical properties under uniaxial tensile tests as well as short- and long-time creep tests. The uniaxial tests are the basis of non-linear elastic description while the creep tests are used for the evaluation of the stiffness parameters in time and for the identification of the standard viscoelastic model. The...
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Mechanical testing of technical woven fabrics
PublicationThis article presents a review of technical fabrics testing methods used by the authors on the basis of their experience with research on properties of polytetrefluoroethylene-coated fabrics used for Forest Opera in Sopot (Poland). First, the different types of testing methods used for description of mechanical properties (uniaxial tensile tests, biaxial tensile tests and shear tests) of technical woven fabrics are described. The...
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Influence of thermal effects on mechanical properties of PVDF-coated fabric
PublicationThis paper describes the method of laboratory tests necessary for identification of temperature influence on mechanical properties of polyvinylidene fluoride-coated polyester fabric often used for tensile structures. Two nonlinear model descriptions are investigated. The first one is based on the piece-wise linear relations between stress and strain and the second one on the Murnaghan model of solid behavior. This paper is proposed...
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Mechanical properties of polyvinyl chloride-coated fabric under cyclic tests
PublicationThe aim of the present paper is to propose a method of laboratory tests necessary for the identification of mechanical properties of the coated fabric. The material parameters of the coated fabric AF 9032 are specified on the basis of the uniaxial and biaxial tensile tests. For the identification process, the techniques based on the least squares methods are used. Additionally, the uniaxial and biaxial cyclic tests are performed...
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Manufacture and research of TPS/PE biocomposites properties
PublicationIn this paper the process of native starch preparing for modification by extrusion and manufacture of biocomposites is presented. The first aim of this study was to determine the mixing and granulating condition of native starch to obtain granulated native starch. For mixing and granulation of native starch Intensive Mixer manufactured by Maschinenfabrik Gustav Eirich was used. Mixing and granulation in a single process is a new...
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Morphology and mechanical properties of polyamide/clay nanocomposites toughened with NBR/NBR-g-GMA: A comparative study
PublicationThis work highlights the importance of nanoclay dispersion state in the nanocomposites containing polyamide 6 (PA6), nanoclay and elastomers as well as clay localization at the interface of thermoplastic/elastomer. Morphology and mechanical properties of a series of nanocomposites containing acrylonitrile butadiene rubber (NBR), glycidyl methacrylate-grafted NBR (NBR-g-GMA), and combined NBR/NBR-g-GMA were compared and discussed...
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Elastoplastic nonlinear FEM analysis of FGM shells of Cosserat type
PublicationThe paper is a continuation of [1] where the formulation of the elastic constitutive law for functionally graded materials (FGM) on the grounds of nonlinear 6-parameter shell theory with the 6th parameter (the drilling degree of freedom) was presented. Here the formulation is extended to the elasto-plastic range. The material law is based on Cosserat plasticity and employs the well-known Tamura-Tomota-Ozawa (TTO) [2] mixture...
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A new type of (TiZrNbTaHf)N/MoN nanocomposite coating: Microstructure and properties depending on energy of incident ions
PublicationA novel (TiZrNbTaHf)N/MoN nanocomposite coatings, which consist of the nitride of the high-entropy alloy and the binary nitride, were synthesized by vacuum-arc deposition at various substrate biases. The elemental composition, chemical bonding state, phase structure, microstructure and mechanical properties of the coatings were studied by high-resolution experimental methods: SIMS, GDMS, XPS, XRD, HR-TEM and nano-indentation. It...
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2-D constitutive equations for orthotropic Cosserat type laminated shells in finite element analysis
PublicationWe propose 2-D Cosserat type orthotropic constitutive equations for laminated shells for the purpose of initial failure estimation in a laminate layer. We use nonlinear 6-parameter shell theory with asymmetric membrane strain measures and Cosserat kinematics as the framework. This theory is specially dedicated to the analysis of irregular shells, inter alia, with orthogonal intersections, since it takes into account the drilling...
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A facile approach to fabricate load-bearing porous polymer scaffolds for bone tissue engineering
PublicationBiodegradable porous scaffolds with oriented interconnected pores and high mechanical are load-bearing biomaterials for bone tissue engineering. Herein, we report a simple, non-toxic, and cost-effective method to fabricate high-strength porous biodegradable scaffolds, composed of a polymer matrix of polycaprolactone (PCL) and water-soluble poly (ethylene oxide) (PEO) as a sacrificial material by integrating annealing treatment,...
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Stabilization of Solid Residues Obtained During Sewage Sludge Thermal Treatment
PublicationCurrently wastewater treatment plants are still dealing with the problem of ecological management of sewage sludge. Nowadays, thermal utilization is considered the most eco-friendly way of processing excess sludge. However, during mentioned process, fractions of ashes and dusts are generated. Such wastes, especially dusts fraction, can be potentially harmful for the environment and wastes should be stabilized before further management....
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CFFT columns in road through railroad crossings
PublicationThere were 12801 road through railroad one-level crossings in Poland in 2018. 215 accidents happened at them in 2018. In order to increase safety in rail and road traffic two-level crossings should be used. They are definitely safer and make the traffic more smooth. In the design and construction of two-level intersections of railway and road or path columns of circular cross-section are often used. They can be successfully replaced...
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Acoustic emission signals in concrete beams under 3-point bending (plain concrete, steel fibre reinforced concrete, steel bar reinforced concrete)
Open Research DataThe DataSet contains the results of the mechanical behaviour of concrete beams with dimensions 40 x 40 x 160 cm3under the 3-point bending. Two concrete mixes, both based on the same design, were produced in the test programme. Mixture #1 was the plain concrete (PC), consisting of cement CEM I 42.5R (380 kg/m3), water (165 kg/m3), aggregate 0/2 mm (648...
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Wpływ mikrosfer-frakcji odpadów paleniskowych na mikrostrukturę i wybrane właściwości uzytkowe
PublicationIn this study, the microspheres samples were collected from national power station „Dolna Odra”. In this study, the following materials were used: Portland cement class 32,5R and aggregates of 2-8 and 8-16 fractions and natural sand with a maximum grain size of 2 mm and water. Concrete mixtures were made with microspheres additions of 15%, 25% and 40%. A constant water to binder ratio (w/b) of 0,52 was used throughout the investigation....
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ASSESSMENT OF VOLATILE ORGANIC COMPOUNDS EMISSIONS FROM RECYCLED LOW-DENSITY POLYETHYLENE STREAMS
PublicationThe recycling of plastics is currently one of the most significant industrial challenges. Due to the enormous amounts of plastic wastes generated by various industry branches, it is essential to look for the potential methods of their utilization. Nevertheless, it should not be forgotten that recycled plastics are not pure materials, and they still may show an unfavorable environmental impact. They may contain different contaminants...
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Sustainable Chemically Modified Mater-Bi/Poly(ε-caprolactone)/Cellulose Biocomposites: Looking at the Bulk through the Surface
PublicationSustainable polymer composites are progressively under development in a technological paradigm shift from "just use more and more" to "convert into value-added products". The bio-based blends based on Mater-Bi bio-plastic (A) and poly(ε-caprolactone) (B), at a weight ratio of 70:30 (A:B) were developed, followed by the addition of UFC100 cellulose (C) filler to yield 70/30 (w/w) (A:B)/C sustainable biocomposites. The effects of...
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Ni-based compounds in multiwalled graphitic shell for electrocatalytic oxygen evolution reactions
Open Research DataThis study investigates Ni-based compounds (Ni, NiO, Ni3C) coated with a graphitic shell as electrocatalysts for the oxygen evolution reaction (OER). Electron paramagnetic resonance (EPR) and X-ray diffraction (XRD) are employed to identify the presence and contribution of Nickel ions (Ni0, Ni2+, Ni3+) and determine the phase composition. Electrochemical...
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The lethal effect of hydrotechnical concrete on freshwater Bivalvia
PublicationMost hydrotechnical buildings under construction demand the concrete mixture to be set directly under water. The main reason for such a procedure is to limit the washing away of the the concrete binding mixture and to increase the efficiency of organisation of work so as to ensure continuity in concreting. The impact on the aquatic environment of recent developments in concrete technology and the use of new components has not yet...
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Water sorption and blistering of GFRP laminates with varying structures
PublicationThe microstructures, water absorption as well as blistering was studied for bi- and tri- axial glass fibre vinyl ester and polyester -matrix laminates coated with gel coat layer and uncoated. The effect of manufacturing technique on water sorption characteristics was considered. It was found that water sorption characteristics of GFRP depend on manufacturing methods. The least water intake was found for specimens having perfect...
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Band engineering of BiOBr based materials for photocatalytic wastewater treatment via advanced oxidation processes (AOPs) – A review
PublicationSemiconductor based photocatalysts have been an efficient technology for water and wastewater remediation, addressing the concepts of green chemistry and sustainable development. Owing to narrow and suitable band structure, BiOBr is a promising candidate for efficient wastewater treatment via photocatalysis. Enhancement of photocatalytic properties can be obtained by various techniques like doping, element rich strategy, facet...
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Working in harmony with nature. Green office buildings in a present-day city
PublicationMetropolis - as main point of people's migration, mostly because of work, have to face sustainable development as a strategy for the near future. This article describes possible ways leading to the best office building concepts in the design process. Searching for a workspace in harmony with nature is one of the aspects of a balanced development. The challenge is to create functional, compact, environmentally friendly and healthy...
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Nowe czynniki chłodnicze i zmiany w instalacjach chłodniczych. Cz.2
PublicationW drugiej części artykułu kontynuowany jest temat związany z ograniczeniami stosowania syntetycznych czynników chłodniczych. W części pierwszej przedstawiono tendencje do zastępowania wycofywanych substancji czynnikami naturalnymi. Niniejszy artykuł traktuje natomiast o możliwości wykorzystywania nowych, syntetycznych czynników z grupy HFO, będących substancjami bezpiecznymi dla środowiska naturalnego, w kontekście ich wpływu na...
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A Generalized Framework Towards Structural Mechanics of Three-layered Composite Structures
PublicationThree-layered composite structures find a broad application. Increasingly, composites are being used whose layer thicknesses and material properties diverge strongly. In the perspective of structural mechanics, classical approaches to analysis fail at such extraordinary composites. Therefore, emphasis of the present approach is on arbitrary transverse shear rigidities and structural thicknesses of the individual layers. Therewith...
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Recent Advances in Polymer Nanocomposites: Unveiling the Frontier of Shape Memory and Self-Healing Properties—A Comprehensive Review
PublicationShape memory and self-healing polymer nanocomposites have attracted considerable attention due to their modifiable properties and promising applications. The incorporation of nanomaterials (polypyrrole, carboxyl methyl cellulose, carbon nanotubes, titania nanotubes, graphene, graphene oxide, mesoporous silica) into these polymers has significantly enhanced their performance, opening up new avenues for diverse applications. The...
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Effect of Chitosan Solution on Low-Cohesive Soil’s Shear Modulus G Determined through Resonant Column and Torsional Shearing Tests
PublicationIn this study the effect of using a biopolymer soil stabilizer on soil stiffness characteristics was investigated. Chitosan is a bio-waste material that is obtained by chemical treatment of chitin (a chemical component of fungi or crustaceans’ shells). Using chitosan solution as a soil stabilizer is based on the assumption that the biopolymer forms temporary bonds with soil particles. What is important is that these bonds are biodegradable,...
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Evaluation of Green Sample Preparation Techniques for Organic Compounds
PublicationNowadays, Green Analytical Chemistry (GAC) idea is of high importance, with impact on the rapid growth in the sample preparation area with special emphasis on sample preparation simplification, miniaturization and automation. Due to the fact that GAC is of high importance today, this study is focused on the evaluation of green sample preparation techniques for organic compounds. It is well known that sample preparation is considered...
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The Effect of Cryogenic Treatment on Microstructure and Mechanical Response of AISI D3 Tool Steel Punches
PublicationRecently, deep cryogenic treatment is performed to improve the mechanical responses (wear, hardness, fatigue, and thermal conductivity) of various steel components. Researchers have tried to evaluate the eco-friendly and nontoxic process to optimize the parameters. Cold-shearing punches used to manufacture various holes that undergo severe impact loading and wear in the metal forming process. This study concerns the effect of soaking...
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Linear viscoelastic transversely isotropic model based on the spectral decomposition of elasticity tensors
PublicationThe linear viscoelasticity is still a useful model in the engineering for studying the behavior of materials loaded with different loading rates (frequencies). Certain types of materials reveal also an anisotropic behavior: fiber reinforced composites, asphalt concrete mixtures, or wood, to name a few. In general, researchers try to identify experimentally the dependence of engineering constants like: directional Young’s moduli...
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Assessment of the Environmental Impact of a Car Tire throughout Its Lifecycle Using the LCA Method
PublicationThere are numerous threats to the natural environment that pose a significant risk both to the environment and to human health, including car tires. Thus, there is a need to determine the impact of the life cycle of car tires on the environment, starting with the processes of raw materials acquisition, production, and ending with end-of-life management. Therefore, the authors of this study chose to do research on passenger car...
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Polyurethanes modified with natural polymers for medical application. I. Polyurethanes/ Chitosan and polyurethane/collagen.
PublicationFor over three decades polyurethanes (PUR or PU) have been reported for application in a variety of medical devices. These polymers consist of hard and soft segments, which allow for more subtle control of their structure and properties. By varying the composition of the different segments, properties of PURcan be tuned up for use in many areas of medicine. Recently there is a great interest in modification of biomedical PUR with...
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MODELLING OF CONCRETE FRACTURE AT AGGREGATE LEVEL USING DEM BASED ON X-RAY mu CT IMAGES OF INTERNAL STRUCTURE
PublicationThe paper describes two-dimensional meso-scale numerical results of fracture in notched concrete beams under quasi-static three-point bending. Concrete was modelled as a random heterogeneous 4-phase material composed of aggregate particles, cement matrix, interfacial transitional zones (ITZs) and air voids. As a numerical approach, the discrete element method (DEM) was used. The concrete micro-structure in calculations was directly...
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Development of polyurethanes for bone repair
PublicationThe purpose of this paper is to review recent developments on polyurethanes aimed at the design, synthesis, modifications, and biological properties in the field of bone tissue engineering. Different polyurethane systems are presented and discussed in terms of biodegradation, biocompatibility and bioactivity. A comprehensive discussion is provided of the influence of hard to soft segments ratio, catalysts, stiffness and hydrophilicity...
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Interrelated shape memory and Payne effect in polyurethane/graphene oxide nanocomposites
PublicationWe report the fabrication of graphene oxide (GO) based polyurethane (PU) nanocomposites by a simple method of mixing and their shape memory properties at different temperatures. Both the polymer and the filler were synthesized in the laboratory by simple and easy methods – PU by pre-polymer method and GO by improved graphene oxide synthesis method. High molecular level dispersion of GO platelets within the PU matrix and thus good...
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Fe local structure in Pt-free nitrogen-modified carbon based electrocatalysts: XAFS study
PublicationThe paper presents a new results on the bonding environment (coordination number and geometry) and on oxidation states of Fe in nitrogen-modified Fe/C composites used as Pt-free catalysts for oxygen reduction in Direct Hydrogen Fuel Cells. Starting from glucose or fructose, two catalysts displaying different electrochemical performance were prepared and studied in the form of pristine powder and thin catalytic layer of electrode...
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Novel Low-Loss Substrates for 5G Applications
PublicationThis paper presents a feasibility study of a new type of microwave low-loss dielectric substrates for 5G network applications. The new substrate materials are composites of polypropylene and high-dielectric-constant micro-ceramics. This combination is expected to form a very low-loss dielectric material at low fabrication cost. Two substrate samples with different dielectric properties are fabricated and their characteristics at...
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Effect of Particle Size of Fly Ash Microspheres (FAMs) on the Selected Properties of Concrete
PublicationThis paper presents the investigations of selected properties of concrete containing two fractions of fly ash microspheres (FAMs) with grain size up to 200 μm and up to 500 μm. Concrete mixtures with ordinary Portland cement and three substitution rates of cement by FAMs, 1.3%, 2.0%, and 2.6%, were investigated. For all concrete mixes, the constant water–binder ratio (w/b) equal to 0.50 was used. The research program included the...
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Studies on Silver Ions Releasing Processes and Mechanical Properties of Surface-Modified Titanium Alloy Implants
PublicationDispersed silver nanoparticles (AgNPs) on the surface of titanium alloy (Ti6Al4V) and titanium alloy modified by titania nanotube layer (Ti6Al4V/TNT) substrates were produced by the chemical vapor deposition method (CVD) using a novel precursor of the formula [Ag5(O2CC2F5)5(H2O)3]. The structure and volatile properties of this compound were determined using single crystal X-ray diffractometry, variable temperature IR spectrophotometry...
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Enhanced photocatalytic activity of accordion-like layered Ti3C2 (MXene) coupled with Fe-modified decahedral anatase particles exposing {1 0 1} and {0 0 1} facets
PublicationNew composites consisting of decahedral anatase particles exposing {001} and {101} facets coupled with accordion-like layered Ti3C2 with boosted photocatalytic activity towards phenol and carbamazepine degradation were investigated. The photocatalysts were characterized with X-ray diffraction (XRD), diffuse reflectance spectroscopy (DR/UV–Vis), Brunauer-Emmett-Teller (BET) specific surface area, Raman spectroscopy, scanning electron...