Search results for: ORBITAL BLOW-OUT FRACTURE
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Reaction of aniline with ammonium persulphate and concentrated hydrochloric acid: Experimental and DFT studies
PublicationIn this paper, the reaction of aniline with ammonium persulphate and concentrated HCl was studied. As a result of our experimental studies, 2,4,6-trichlorophenylamine was identified as the main product. This shows that a high concentration of HCl does not favour oxidative polymerisation of phenylamine, even though the ammonium persulphate/HCl system is widely used in polyaniline synthesis. On the basis of the experimental data...
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Threshold photoelectron studies of isoxazole over the energy range 9.9-30 eV
PublicationThe threshold photoelectron spectrum of the isoxazole molecule, C3H3NO has been measured over the photon energy range 9.9-30 eV with the use of synchrotron radiation. In the 9.9-10.8 eV range, corresponding to photoionization from the highest occupied molecular orbital 3a"(π3), seven well resolved vibrational series have been observed and their modes are tentatively assigned. A strong adiabatic ionization, with an energy of 11.132...
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Meso-mechanical modelling of damage in concrete using discrete element method with porous ITZs of defined width around aggregates.
PublicationArtykuł omawia wyniki obliczeń numerycznych pękania dla betonu stosując metodę elementów dyskretnych. Beton był opisany jako materiał 4-fazowy i był poddany zginaniu. W obliczeniach uwzględniono strefy ITZ o skończonej szerokości dookoła wszystkich ziaren kruszywa. Nacisk położono na przebieg mikropęknięć przy kruszywie. Wyniki porównano bezpośrednio z doświadczeniami. Obliczenia wykonano także dla szorstkich ziaren kruszywa....
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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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Application of the 3D DEM in the modelling of fractures in pre-flawed marble specimens during uniaxial compression
PublicationPrzedstawiono w tym artykule wyniki modelowania pęknięć w cylindrycznych próbkach marmurowych ze wstępnymi nacięciami w czasie jednoosiowego ściskania . Zastosowano metodę elementów dyskretnych (DEM). Zbadano propagację i koalescencję pęknięć w próbkach marmuru z istniejącymi otwartymi nacięciami pod różnymi kątami do poziomu. Wyniki numerycznych symulacji trójwymiarowych (3D) zostały bezpośrednio porównane z badaniami laboratoryjnymi....
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Hydrogen degradation of pre-oxidized zirconium alloys
PublicationThe presence of the oxide layers on Zr alloys may retard or enhance the hydrogen entry and material degradation, depending on the layer features. This research has been aimed to determine the effects of pre-oxidation of the Zircaloy-2 alloy at a different temperature on hydrogen degradation. The specimens were oxidised in laboratory air at 350°C, 700°C, and 900°C. After, some samples were tensed at 10-5 strain rate and simultaneously...
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Excited states of isoxazole molecules studied by electron energy-loss spectroscopy
PublicationElectron energy-loss spectra were measured in isoxazole in the excitation energy range 3.5−10 eV to investigate the valence excited states. Spectra recorded at different scattering conditions enabled the identification of the singlet and triplet states and the determination of their vertical excitation energies. The two lowest energy triplet bands, ππ* 13A' and ππ* 23A' at 4.20 and 5.30 eV, respectively show vibrational progressions....
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Excited state properties of a series of molecular photocatalysts investigated by time dependent density functional theory.
PublicationTime dependent density functional theory calculations are applied on a series of molecular photocatalysts of the type [(tbbpy)2M1(tpphz)M2X2]2+ (M1 = Ru, Os; M2 = Pd, Pt; X = Cl, I) in order to provide information concerning the photochemistry occurring upon excitation of the compounds in the visible region. To this aim, the energies, oscillator strengths and orbital characters of the singlet and triplet excited states are investigated....
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Magnetic field effects in dye-sensitized solar cells controlled by different cell architecture
PublicationThe charge recombination and exciton dissociation are generally recognized as the basic electronic processes limiting the efficiency of photovoltaic devices. In this work, we propose a detailed mechanism of photocurrent generation in dye-sensitized solar cells (DSSCs) examined by magnetic field effect (MFE) technique. Here we demonstrate that the magnitude of the MFE on photocurrent in DSSCs can be controlled by the radius and...
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Determination of flow properties of a parallel connection of two pneumatic elements with (C=6.40, b=0.45) and (C=6.00, b=0.25) from changes in air pressure in a tank being emptied
Open Research DataThe aim of the study was to determine the flow properties of parallel connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for a pressure relief valve and a air blow gun (with nozzle removed) arranged in parallel. Three test configurations were used: (1) being emptied tank -> PRV -> ambient...
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Determination of flow properties of a parallel connection of two pneumatic elements with (C=3.30, b=0.40) and (C=6.00, b=0.25) from changes in air pressure in a tank being emptied
Open Research DataThe aim of the study was to determine the flow properties of parallel connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for a pressure relief valve and a air blow gun (with nozzle removed) arranged in parallel. Three test configurations were used: (1) being emptied tank -> PRV -> ambient...
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Determination of flow properties of a parallel connection of two pneumatic elements with (C=7.30, b=0.49) and (C=6.00, b=0.25) from changes in air pressure in a tank being emptied
Open Research DataThe aim of the study was to determine the flow properties of parallel connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for a pressure relief valve and a air blow gun (with nozzle removed) arranged in parallel. Three test configurations were used: (1) being emptied tank -> PRV -> ambient...
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Determination of flow properties of a parallel connection of two pneumatic elements with (C=5.50, b=0.37) and (C=6.00, b=0.25) from changes in air pressure in a tank being emptied
Open Research DataThe aim of the study was to determine the flow properties of parallel connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for a directional control valve and a air blow gun (with nozzle removed) arranged in parallel. Three test configurations were used: (1) being emptied tank -> DCV ->...
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Determination of flow properties of a parallel connection of two pneumatic elements with (C=2.40, b=0.26) and (C=6.00, b=0.25) from changes in air pressure in a tank being emptied
Open Research DataThe aim of the study was to determine the flow properties of parallel connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for a directional control valve and a air blow gun (with nozzle removed) arranged in parallel. Three test configurations were used: (1) being emptied tank -> DCV ->...
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Determination of flow properties of a parallel connection of two pneumatic elements with (C=2.80, b=0.25) and (C=6.00, b=0.25) from changes in air pressure in a tank being emptied
Open Research DataThe aim of the study was to determine the flow properties of parallel connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for a directional control valve and a air blow gun (with nozzle removed) arranged in parallel. Three test configurations were used: (1) being emptied tank -> DCV ->...
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Determination of flow properties of a parallel connection of two pneumatic elements with (C=2.00, b=0.11) and (C=6.00, b=0.25) from changes in air pressure in a tank being emptied
Open Research DataThe aim of the study was to determine the flow properties of parallel connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for a directional control valve and a air blow gun (with nozzle removed) arranged in parallel. Three test configurations were used: (1) being emptied tank -> DCV ->...
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Determination of flow properties of a parallel connection of two pneumatic elements with (C=2.10, b=0.14) and (C=6.00, b=0.25) from changes in air pressure in a tank being emptied
Open Research DataThe aim of the study was to determine the flow properties of parallel connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for a directional control valve and a air blow gun (with nozzle removed) arranged in parallel. Three test configurations were used: (1) being emptied tank -> DCV ->...
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Determination of flow properties of a parallel connection of two pneumatic elements with (C=6.20, b=0.38) and (C=6.00, b=0.25) from changes in air pressure in a tank being emptied
Open Research DataThe aim of the study was to determine the flow properties of parallel connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for a pressure relief valve and a air blow gun (with nozzle removed) arranged in parallel. Three test configurations were used: (1) being emptied tank -> PRV -> ambient...
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Determination of flow properties of a parallel connection of two pneumatic elements with (C=5.70, b=0.32) and (C=6.00, b=0.25) from changes in air pressure in a tank being emptied
Open Research DataThe aim of the study was to determine the flow properties of parallel connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for a directional control valve and a air blow gun (with nozzle removed) arranged in parallel. Three test configurations were used: (1) being emptied tank -> DCV ->...
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Determination of flow properties of a parallel connection of two pneumatic elements with (C=5.30, b=0.38) and (C=6.00, b=0.25) from changes in air pressure in a tank being emptied
Open Research DataThe aim of the study was to determine the flow properties of parallel connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for a pressure relief valve and a air blow gun (with nozzle removed) arranged in parallel. Three test configurations were used: (1) being emptied tank -> PRV -> ambient...
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Determination of flow properties of a parallel connection of two pneumatic elements with (C=4.40, b=0.42) and (C=6.00, b=0.25) from changes in air pressure in a tank being emptied
Open Research DataThe aim of the study was to determine the flow properties of parallel connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for a pressure relief valve and a air blow gun (with nozzle removed) arranged in parallel. Three test configurations were used: (1) being emptied tank -> PRV -> ambient...
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Hydrogen Damage in Superaustenitic 904L Stainless Steels
Publicationresults on the influence of hydrogen on corrosion resistance and of hydrogen embrittlement of 904L superaustenitic stainless steel were investigated. The cracking behavior was studied by performing a slow strain rate test in synthetic seawater under varying cathodic polarization conditions. The results showed that the steel’s plasticity varied with the applied cathodic current density. Significant reductions in ductility were found,...
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Fatigue Bending of V-Notched Cold-Sprayed FeCoCrNiMn Coatings
PublicationCold-spray coatings were produced by FeCoCrNiMn high-entropy alloy powders deposited on carbon steel substrate. The coatings were realized at intermediate temperature and high pressure (at 1100 °C and 7 MPa). The coating microstructure was characterized by scanning electron microscopy and X-ray diffraction, revealing a very dense deposition and high flattening ratio of the splatted particles. This had a large influence on the...
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Simulations of hydro-fracking in rock mass at meso-scale using fully coupled DEM/CFD approach
PublicationThe paper deals with two-dimensional (2D) numerical modelling of hydro-fracking (hydraulic fracturing) in rocks at the meso-scale. A numerical model was developed to characterize the properties of fluid-driven fractures in rocks by combining the discrete element method (DEM) with computational fluid dynamics (CFD). The mechanical behaviour of the rock matrix was simulated with DEM and the behaviour of the fracturing fluid flow...
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RuAl6—An Endohedral Aluminide Superconductor
PublicationSuperconductivity is reported in an endohedral aluminide compound, RuAl6, with Tc = 1.21 K. The normalized heat capacity jump at Tc, ΔC/γTc = 1.58, confirms bulk superconductivity. The Ginzburg–Landau parameter of κ = 9.5 shows that RuAl6 is a type-II superconductor. Electronic structure calculations for RuAl6 are explored in comparison to its structural analogue ReAl6 (Tc = 0.74 K). The stability of the phases is discussed in...
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Positron collisions with molecular hydrogen: cross sections and annihilation parameters calculated using theR-matrix with pseudo-states method
PublicationThe molecular R-matrix with pseudo-states (MRMPS) method is employed to study positron collisions with H2. The calculations employ pseudo-continuum orbital sets containing up to h (l = 5) functions. Use of these high l functions is found to give converged eigenphase sums. Below the positronium formation threshold, the calculated cross sections agree with other high-accuracy theories and generally with the measurements. Calculation...
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Hydrogen induced degradation of structural steel exposed to the technical liquid hydrocarbons
PublicationSusceptibility of the differently heat treated 26H2MF steel to stress corrosion cracking has been evaluated in the constant strain rate tension tests done at the strain rate 10-6s-1 and in the constant load tests done at the 0,98 of fracture load. The boiler fuel and the aged mineral oil at 135C and 80C respectively, have been used as the aggressive environments.
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EH36 steel for shipbuilding - Charpy impact test reslut in vary tempetatures
Open Research DataThe basic method of ductility designation of structural steels is the Charpy impact test. The test consists of a single strike of the specimen using a Charpy pendulum. Its result is the value of work necessary to break a specimen at a test temperature. Despite its many advantages, such as its short implementation time and low costs, it has its disadvantages,...
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EXPERIMENTAL AND NUMERICAL INVESTIGATION ON SPECIMEN GEOMETRY EFFECT ON THE CTOD VALUE FOR VL-E36 SHIPBUILDING STEEL
PublicationThere are special cases in the marine industry, where additional material tests, such as the fracture toughness test, must be performed. Additional fracture toughness tests, such as CTOD (Crack Tip Opening Displacement), are typically performed on three-point bend specimens. The dimension that defines all the specimen dimensions is the thickness of the material to be tested. It is recommended by classification societies (e.g. DNVGL)...
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Impact Behaviour of Glass Fribre /Epoxy Composites with Nano-Enhanced Resin after Water Exposure
PublicationImpact behaviour of glass fibre /epoxy composites with nano- SiO2 modified resin was studied in terms of low velocity impact after water exposure. Nanocomposites with 1%, 2%, 3% 5% 7% nano-SiO2 (Nanopox- Evonic) were investigated. Peak impact load and impact damage area as a function of nanoparticle contents were compared for dry specimens and for samples exposed to water (0.7 %wt. 1.7% water absorbed) at 1J, 2J 3J impact energies....
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Wpływ zbrojenia polimerowymi włóknami rozproszonymi na wybrane właściwości mieszanek mineralno-asfaltowych
PublicationW artykule przedstawiono wybrane wyniki badań mieszanek mineralno-asfaltowych zbrojonych polimerowymi włóknami rozproszonymi. Ocenie poddano mieszankę włókien zbrojących aramidowo-poliolifenowych pod kątem wpływu ich zastosowania na właściwości niskotemperaturowe i odporności na deformacje trwałe mieszanek mineralno-asfaltowych. Właściwości niskotemperaturowe oceniano na podstawie testu zginania próbek belkowych oraz na podstawie...
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EH36 steel for shipbuilding (plate thicnkness 40 mm) - CMOD - force record, a0/W = 0.5
Open Research DataThe basic method of ductility designation of structural steels is the Charpy impact test. The test consists of a single strike of the specimen using a Charpy pendulum. Its result is the value of work necessary to break a specimen at a test temperature. Despite its many advantages, such as its short implementation time and low costs, it has its disadvantages,...
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EH36 steel for shipbuilding (plate thicnkness 40 mm) - CMOD - force record, a0/W = 0.6
Open Research DataThe basic method of ductility designation of structural steels is the Charpy impact test. The test consists of a single strike of the specimen using a Charpy pendulum. Its result is the value of work necessary to break a specimen at a test temperature. Despite its many advantages, such as its short implementation time and low costs, it has its disadvantages,...
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EH36 steel for shipbuilding (plate thicnkness 30 mm) - CMOD - force record, a0/W = 0.6
Open Research DataThe basic method of ductility designation of structural steels is the Charpy impact test. The test consists of a single strike of the specimen using a Charpy pendulum. Its result is the value of work necessary to break a specimen at a test temperature. Despite its many advantages, such as its short implementation time and low costs, it has its disadvantages,...
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EH36 steel for shipbuilding (plate thicnkness 60 mm) - CMOD - force record, a0/W = 0.6
Open Research DataThe basic method of ductility designation of structural steels is the Charpy impact test. The test consists of a single strike of the specimen using a Charpy pendulum. Its result is the value of work necessary to break a specimen at a test temperature. Despite its many advantages, such as its short implementation time and low costs, it has its disadvantages,...
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EH36 steel for shipbuilding (plate thicnkness 50 mm) - CMOD - force record, a0/W = 0.5
Open Research DataThe basic method of ductility designation of structural steels is the Charpy impact test. The test consists of a single strike of the specimen using a Charpy pendulum. Its result is the value of work necessary to break a specimen at a test temperature. Despite its many advantages, such as its short implementation time and low costs, it has its disadvantages,...
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EH36 steel for shipbuilding (plate thicnkness 50mm) - CMOD - force record, a0/W = 0.6
Open Research DataThe basic method of ductility designation of structural steels is the Charpy impact test. The test consists of a single strike of the specimen using a Charpy pendulum. Its result is the value of work necessary to break a specimen at a test temperature. Despite its many advantages, such as its short implementation time and low costs, it has its disadvantages,...
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EH36 steel for shipbuilding (plate thicnkness 30 mm) - CMOD - force record, a0/W = 0.5
Open Research DataThe basic method of ductility designation of structural steels is the Charpy impact test. The test consists of a single strike of the specimen using a Charpy pendulum. Its result is the value of work necessary to break a specimen at a test temperature. Despite its many advantages, such as its short implementation time and low costs, it has its disadvantages,...
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A new open-source software developed for numerical simulations usingdiscrete modeling methods
PublicationThe purpose of this work is to present the development of an open-source software based on a discrete description of matter applied to study the behavior of geomaterials. This software uses Object Oriented Programming techniques, and its methodology design uses three different methods, which are the Discrete Element Method (DEM) [F. Donzé, S.A. Magnier, Formulation of a three-dimensional numerical model of brittle behavior, Geophys....
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Electron-impact ionization of fluoromethanes – Review of experiments and binary-encounter models
PublicationExperiments and recommended data on electron-impact ionization of methane and fluoromethanes (CH3F, CH2F2, CHF3, CF4) are reviewed and compared with binary-encounter models (Gryzinski’s, ´ Deutsch and Märk’s, and Kim and Rudd’s). A good agreement between recent experiments and the two latter classical-like models is shown. Kim and Rudd’s model (calculated presently in the restricted HartreeFock 6-31**G orbital basis) predicts well...
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Superconductivity–Electron Count Relationship in Heusler Phases─the Case of LiPd2Si
PublicationWe report superconductivity in the full Heusler compound LiPd2Si (space group Fm3̅m, No. 225) at a critical temperature of Tc = 1.3 K and a normalized heat capacity jump at Tc, ΔC/γTc = 1.1. The low-temperature isothermal magnetization curves imply type-I superconductivity, as previously observed in LiPd2Ge. We show, based on density functional theory calculations and using the molecular orbital theory approach, that while LiPd2Si...
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Electronic structure and magnetism of samarium and neodymium adatoms on free-standing graphene
PublicationThe electronic structure of selected rare-earth atoms adsorbed on a free-standing graphene was investigated using methods beyond the conventional density functional theory (DFT+U, DFT +HIA, and DFT+ED). The influence of the electron correlations and the spin-orbit coupling on the magnetic properties has been examined. The DFT+U method predicts both atoms to carry local magnetic moments (spin and orbital) contrary to a nonmagnetic...
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An innovative approach to the forecasting of energetic effects while wood sawing
PublicationIn the classical approach, energetic effects (cutting forces and cutting power) of wood sawing process are generally calculated on the basis of the specific cutting resistance, which is in the case of wood cutting the function of more or less important factors. On the other hand, the cutting forces (power) problem may be tackled with an innovative, up-to-date fundamental analysis of the mechanics of sawing based on modern fracture...
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An Innovative Approach to the Forecasting of Energetic Effects While Wood Sawing
PublicationIn the classical approach, energetic effects (cutting forces and cutting power) of wood sawing process are generally calculated on the basis of the specifi c cutting resistance, which is in the case of wood cutting the function of more or less important factors. On the other hand, the cutting forces (power) problem may be tackled with an innovative, up-to-date fundamental analysis of the mechanics of sawing based on modern fracture mechanics....
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Adhesive Monitoring with Instrumented Wedge Test
PublicationThe wedge test (sometimes called the Boeing wedge test) is amongst the most readily exploitable techniques for assessment of the rate-dependent fracture energy of adhesive materials when used to bond relatively rigid substrates. With its siblings: the double cantilever beam (DCB), and the tapered double cantilever beam (TDCB), a force is applied, essentially in cleavage, to provoke substrate separation perpendicularly to the bondline...
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Quantitative assessment of the influence of tensile softening of concrete in beams under bending by numerical simulations with XFEM and cohesive cracks
PublicationResults of the numerical simulations of the size effect phenomenon for concrete in comparison with experimental data are presented. In-plane geometrically similar notched and unnotched beams under three-point bending are analyzed. EXtended Finite Element Method (XFEM) with a cohesive softening law is used. Comprehensive parametric study with the respect to the tensile strength and the initial fracture energy is performed. Sensitivity...
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Microstructure and Mechanical Properties of Carboxylated Nitrile Butadiene Rubber/Epoxy/XNBR-grafted Halloysite Nanotubes Nanocomposites
PublicationThe effect of various amounts of carboxylated nitrile butadiene rubber (XNBR) functionalized halloysite nanotubes (XHNTs) on the cure characteristics, mechanical and swelling behavior of XNBR/epoxy compounds was experimentally and theoretically investigated. The morphology of the prepared XNBR/epoxy/XHNTs nanocomposites was imaged using scanning electron microscopy (SEM). The effects of various XNBR-grafted nanotubes on the damping...
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Influence of e-beam irradiation on poly(aliphatic/aromatic-ester) multiblock copolymers used as biomaterials
PublicationThe use of polymers became more relevant in medical applications for the versatility in processing and enhanced material properties of polymers. In order to be suitable as a biomaterial, it is of medical importance that these polymers are biocompatible and do not elicit negative responses from the body after implantation. Furthermore during the course of usage under load-bearing conditions, these biomaterials must sustain dynamical...
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Hertzian Crack Propagation in Ceramic Rolling Elements
PublicationThe properties of ceramics are of most interest to rolling element manufacturers. The influence of ring crack size on rolling contact fatigue failure has been studied using numerical fracture analysis. Such crack are very often found on ceramic bearing balls and decrease fatigue life rapidly. The numerical calculations are based on a three dimensional model for the ring crack propagation. The stress intensity factors along crack...
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The Analysis of Working Parameters Decrease in Photovoltaic Modules as a Result of Dust Deposition
PublicationThe aspect of dust accumulation on the surface of photovoltaic (PV) modules should be thoroughly understood in order to minimize possible obstacles affecting energy generation. Several elements affect the amount of pollutant gathered on the surface of a solar device, mainly its localization, which is irreversibly linked to factors such as annual rainfall, occasional snow coverage, or, in a dry climate, increased blow of dust during...