Wyniki wyszukiwania dla: thickness
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Drilling couples and refined constitutive equations in the resultant geometrically non-linear theory of elastic shells
PublikacjaIt is well known that distribution of displacements through the shell thickness is non-linear, in general. We introduce a modified polar decomposition of shell deformation gradient and a vector of deviation from the linear displacement distribution. When strains are assumed to be small, this allows one to propose an explicit definition of the drilling couples which is proportional to tangential components of the deviation vector....
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Low-Coherence Interferometric Fiber-Optic Sensors with Potential Applications as Biosensors
PublikacjaFiber-optic Fabry-Pérot interferometers (FPI) can be applied as optical sensors, and excellent measurement sensitivity can be obtained by fine-tuning the interferometer design. In this work, we evaluate the ability of selected dielectric thin films to optimize the reflectivity of the Fabry-Pérot cavity. The spectral reflectance and transmittance of dielectric films made of titanium dioxide (TiO2) and aluminum oxide (Al2O3) with...
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Application of shifted Chebyshev polynomial-based Rayleigh–Ritz method and Navier’s technique for vibration analysis of a functionally graded porous beam embedded in Kerr foundation
PublikacjaPresent study is dealt with the applicability of shifted Chebyshev polynomial based Rayleigh-Ritz method and Navier’s technique on free vibration of Functionally Graded (FG) beam with uniformly distributed porosity along the thickness of the beam. The material properties such as Young’s modulus, mass density, and Poisson’s ratio are also considered to vary along the thickness of the FG beam as per the power-law exponent model....
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A Proposed Soft Computing Model for Ultimate Strength Estimation of FRP-Confined Concrete Cylinders
PublikacjaIn this paper, the feed-forward backpropagation neural network (FFBPNN) is used to propose a new formulation for predicting the compressive strength of fiber-reinforced polymer (FRP)-confined concrete cylinders. A set of experimental data has been considered in the analysis. The data include information about the dimensions of the concrete cylinders (diameter, length) and the total thickness of FRP layers, unconfined ultimate concrete...
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Cost-Efficient Surrogate Modeling of High-Frequency Structures Using Nested Kriging with Automated Adjustment of Model Domain Lateral Dimensions
PublikacjaSurrogate models are becoming popular tools of choice in mitigating issues related to the excessive cost of electromagnetic (EM)-driven design of high-frequency structures. Among available techniques, approximation modeling is by far the most popular due to its versatility. In particular, the surrogates are exclusively based on the sampled simulation data with no need to involve engineering insight or problem-specific knowledge....
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FLUID BED COATING OF MINITABLETS AND PELLETS WITH OPTIMIZATION OF THE PROCESS BASED ON TAGUCHI METHOD
PublikacjaSmall particles like pellets are coated in fluid bed systems. This method can be also feasible for minitablets but the selection of optimal process parameters is complicated. The aim of the research was to optimize the coating process for minitablets and to compare the conditions required for pellets. Minimum fluidization velocities (umf) for 2.0 and 2.5 mm minitablets and 0.7-0.8 mm or 1.0-1.25 mm pellets were determined experimentally....
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Low-Coherence Interferometric Fiber-Optic Sensors with Potential Applications as Biosensors
PublikacjaFiber-optic Fabry-Pérot interferometers (FPI) can be applied as optical sensors, and excellent measurement sensitivity can be obtained by fine-tuning the interferometer design. In this work, we evaluate the ability of selected dielectric thin films to optimize the reflectivity of the Fabry-Pérot cavity. The spectral reflectance and transmittance of dielectric films made of titanium dioxide (TiO2) and aluminum oxide (Al2O3) with...
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Autogenous Fiber Laser Welding of 316L Austenitic and 2304 Lean Duplex Stainless Steels
PublikacjaThis study presents results of experimental tests on quality of dissimilar welded joints between 316L austenitic and 2304 lean duplex stainless steels, welded without ceramic backing. Fiber laser welded butt joints at a thickness of 8 mm were subjected to non‐destructive testing (visual and penetrant), destructive testing (static tensile test, bending test, and microhardness measurements) and structure observations (macro‐ and...
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The Effectiveness of Rubber Bumpers in Reducing the Effects of Earthquake-Induced Pounding between Base-Isolated Buildings
PublikacjaTh e methods for preventing earthquake-induced structural pounding between two adjacent buildings include ensuring a sufficient separation distance between them or decreasing their relative displacement during seismic excitation. Some equations or even specific values of such gap sizes between two buildings have been introduced so as to avoid collisions. Increasing the stiffness of buildings, using tuned mass dampers, applying...
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TIME- AND FREQUENCY-DOMAIN QUASI-2D SMALL-SIGNAL MOSFET MODELS
PublikacjaA novel approach to small-signal MOSFET modeling is presented in this book. As a result, time- and frequency-domain physics-based quasi-2D NQS four-terminal small-signal MOSFET models are proposed. The time-domain model provides the background to a novel DIBL-included quasi‑2D NQS four-terminal frequency-domain small-signal MOSFET model. Parameters and electrical quantities of the frequency-domain model are described by explicit...
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XRD investigations of the lithium titanate thin films
Dane BadawczeNanocrystalline thin films with 800 nm thickness were prepared by sol–gel method. To examine the influence of the annealing temperature on as-prepared films crystallization, the coatings were heated at temperature from 500 °C up to 600 °C for 20h. Structure of manufactured thin films was investigated using X-ray diffraction (XRD). The most visible...
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Vibroflotation Control of Sandy Soils using DMT and CPTU
PublikacjaVibroflotation is a typical improvement method for the cohesionless deposits of high thickness. The compaction method was applied to densify sandy deposits in Gdynia Port. Compaction control was verified with CPTU and DMT tests. Some examples of interpretation of soundings in pre-treated and compacted sands are shown. The classification diagrams are given for pre-treated and compacted sand. The stress history of the deposits is...
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Modelling of in-plane wave propagation in a plate using spectral element method and Kane-Mindlin theory with application to damage detection
PublikacjaThis paper presents results of experimental and numerical analyses of in-plane waves propagatingin a 5 mm-thick steel plate in the frequency range of 120-300 kHz. For such a thickness/frequency ratio,extensional waves reveal dispersive character. To model in-plane wave propagation taking into account thethickness-stretch effect, a novel 2D spectral element, based on the Kane-Mindlin theory, was formulated. Anapplication of in-plane...
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Properties of surface layers of titanium alloy Ti6Al4V after laser melting processes
PublikacjaThe article presents the investigation results of titanium alloy Ti6Al4V surface layer after laser melting process. The process of laser melting was performed using Nd-YAG laser. The evaluation of structure of the alloy as well as hardness and chemical composition was performed. It was shown that laser melting changes the structure and properties of titanium alloy Ti6Al4V and process parameters as scanning speed affects the thickness...
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Electromagnetic Modeling of Microstrip Elements Aided with Artificial Neural Network
PublikacjaThe electromagnetic modeling principle aided withartificial neural network to designing the microwave widebandelements/networks prepared in microstrip technology is proposedin the paper. It is assumed that the complete information is knownfor the prototype design which is prepared on certain substratewith certain thickness and electric permittivity. The longitudinaland transversal dimensions of new design...
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Measurements of guided wave propagation in CFRP/steel adhesive joints obtained by scanning laser vibrometry
Dane BadawczeThe DataSet contains guided wave signals measured in adhesive joints of steel plates (steel of type S355 with a thickness of 11.9 mm ) and carbon fibre reinforced polymer (CarboDur S1012 with a thickness of 1.24 mm). The samples were as follows: #0 – intact; #1 – 10% disbond; #2 – 20% disbond; #3 – 50% disbond; #4 – 80% disbond; #5 – 100% disbond.
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SEM analysis of the TiO2 layers deposited on a FTO substrates
Dane BadawczeTitanium dioxide layers were deposited on a FTO conducting glass by sol-gel method. For sol gel synthesis butoxy titanium and ethanol were used as a reagents. Samples were sintered in a furnace at temperature of 600 deg. SEM measurements were performed by FEI Quanta FEG250 microscope. SEM images of a cross-section of samples exhibit a porous structures...
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SEM inwestigation of the silver nanostructures
Dane BadawczeSilver thin films with a thickness of 1nm, 3nm, 5nm, 7nm and 9nm were deposited by a table-top magnetron sputtering unit in a pure argon plasma from a high-purity silver target. Silicon wafers was used as a substrates. As-deposired films were annealed in Ar atmosphere at 550 Celsius degree for 15 minutes.As a result of annealing, Ag nanostructures formed...
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Ocena stanu technicznego rurociągu przesyłowego zawiesiny popiołów w Elektrowni Ostrołęka B
PublikacjaPrzedmiotem pracy był rurociąg przesyłowy zawiesiny popiołów przesyłanych z Elektrowni Ostrołęka B. Celem pracy było potwierdzenie przynależności próbek yvyciętych z rurociągu do określonego gatunku stali i ocena stanu materiału po eksploatacji. Dla zrealizowania tego celu wykonano: - analizę składu chemicznego materiału pobranego ze stalowych rur, - mikroanalizę warstw wierzchnich na powierzchni wewnętrznej i zewnętrznej, -...
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Influence of reduction process on the structural and mechanical properties of (Pb,Bi)-(Si,Ge)-O oxide glasses
PublikacjaThe effect of the reduction process in H2 at 380 °C on the microstructure and elemental composition of a glass Bi0.4Pb0.2Si0.4Ox has been investigated. It has been shown that after reduction a clearly separated top layer with a thickness of approx. 50 µm was formed on the surface of the sample. This layer is depleted of oxygen and has higher electrical conductivity than the interior of the glass. It has also been found that some...
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Al-DIAMOND SCHOTTKY TUNNEL DIODES WITH BARRIER HEIGHT CONTROL
PublikacjaFew-nanometer-thick very highly boron-doped p-type layers were fabricated at metal-semiconductor interfaces of Schottky barrier diodes formed with aluminum on polycrystalline diamond. Preliminary results show that hermionically-assisted tunneling mechanism results in lower voltage drops at forward biasing of these diodes than expected for the Al-diamond metal-semiconductor potential barrier B. The effective barrier height Bpeff...
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Geometrically Nonlinear Analysis of Functionally Graded Shells Based on 2-D Cosserat Constitutive Model
PublikacjaIn this paper geometrically nonlinear analysis of functionally graded shells in 6-parameter shell theory is presented. It is assumed that the shell consists of two constituents: ceramic and metal. The mechanical properties are graded through the thickness and are described by power law distribution. Formulation based on 2-D Cosserat constitutive model is used to derive constitutive relation for functionally graded shells. Numerical...
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Bearing capacity of the working platform with kinematic method
PublikacjaBearing capacity of the working platform for heavy tracks was analysed using Distinct Layout Optimization (DLO) method. The platform layer constructed from cohesionless soils is resting on weak cohesive subgrade. Different thickness of the platform, its effective angle of internal friction and undrained shear strength of the soft soil were taken into consideration. Kinematic method permits different failure mechanisms to be analyzed....
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Application of gpr method in diagnostics of reinforced concrete structures
PublikacjaThis paper presents an application of the ground penetration method (GPR) for diagnostics of reinforced concrete structures. In situ measurements were conducted for three civil engineering structures: the ground floor structure, the abutment of the railway viaduct and the concrete well. The dual polarized ground penetrating radar with the antenna operating at a center frequency of 2 GHz was used for GPR surveys. Three different...
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Effect of underwater local cavity welding method conditions on diffusible hydrogen content in deposited metal
PublikacjaOne of the methods with great potential for applications in underwater repairs is local cavity welding. In local cavity method, cooling conditions and diffusible hydrogen amount in weld metal are nearly the same as those existed during welding in the air. This paper presents the results of literature survey and preliminary tests of the effect of local cavity welding conditions on diffusible hydrogen amount in a deposited metal....
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In-situ optical diagnostics of boron-doped diamond films growth
PublikacjaInterferometry is a desirable method for in-situ measurement of thin, dielectric film growth, as it don't modify conditions of film deposition. Here we present interferometrical measurements of thickness of doped diamond films during Chemical Vapor Deposition (CVD) process. For this purpose we used a semiconductor laser with a 405nm wavelength. Additional ex-situ measurement using spectral interferometry and ellipsometry...
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Elastoplastic nonlinear FEM analysis of FGM shells of Cosserat type
PublikacjaThe 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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Wpływ procesu redukcji na właściwości strukturalne i mechaniczne szkieł tlenkowych z grupy (Pb,Bi)-(Si,Ge)-O = Influence of reduction process on the structural and mechanical properties of (Pb,Bi)-(Si,Ge)-O oxide glasses
PublikacjaThe effect of the reduction process in H2 at 380 °C on the microstructure and elemental composition of a glass Bi0.4Pb0.2Si0.4Ox has been investigated. It has been shown that after reduction a clearly separated top layer with a thickness of approx. 50 µm was formed on the surface of the sample. This layer is depleted of oxygen and has higher electrical conductivity than the interior of the glass. It has also been found that some...
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Nonlinear resultant theory of shells accounting for thermodiffusion
PublikacjaThe complete nonlinear resultant 2D model of shell thermodiffusion is developed. All 2D balance laws and the entropy imbalance are formulated by direct through-the-thickness integration of respective 3D laws of continuum thermodiffusion. This leads to a more rich thermodynamic structure of our 2D model with several additional 2D fields not present in the 3D parent model. Constitutive equations of elastic thermodiffusive shells...
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The effect of thermal modification on the quality of the milled surface of beech and pine wood
PublikacjaThe article deals with the effect of thermal modification on the quality of the created surface during milling on CNC milling cutters. The quality of the created surface is evaluated based on surface roughness, specifically its roughness parameter Ra. The observed surface is created by a shank cutter with a diameter of 20 mm and three cutting edges in a spiral at a standard speed of 18,000. min-1. The article compares thermally...
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FEM simulations applied to the failure analysis of RC structure under the influence of municipal sewage pressure
PublikacjaThe paper discusses a failure mechanism of reinforced concrete (RC) structure with steel cover that failed under the influence of municipal sewage pressure. To explain the reasons of failure, in-situ measurements, laboratory experiments and comprehensive Finite Element Method (FEM) computations were performed. Non-destructive in-situ scanning tests were carried out to determine quantity and cover thickness of embedded reinforcement...
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Microporous Polyurethane Thin Layer as a Promising Scaffold for Tissue Engineering
PublikacjaThe literature describes that the most efficient cell penetration takes place at 200–500 µm depth of the scaffold. Many different scaffold fabrication techniques were described to reach these guidelines. One such technique is solvent casting particulate leaching (SC/PL). The main advantage of this technique is its simplicity and cost efficiency, while its main disadvantage is the scaffold thickness, which is usually not less than...
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Deposition of phosphate coatings on titanium within scaffold structure
PublikacjaPurpose: Existing knowledge about the appearance, thickness, and chemical composition of phosphate coatings on titanium inside porous structures is insufficient. Such knowledge is important for the design and fabrication of porous implants. Methods: Metallic scaffolds were fabricated by selective laser melting of 316L stainless steel powder. Phosphate coatings were deposited on Ti sensors placed either outside the scaffolds or...
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Implementation of Hermite-Ritz method and Navier’s Technique for Vibration of Functionally Graded Porous Nanobeam Embedded in Winkler-Pasternak Elastic Foundation Using bi-Helmholtz type of nonlocal elasticity
PublikacjaPresent study is devoted to investigating the vibration characteristics of Functionally Graded (FG) porous nanobeam embedded in an elastic substrate of Winkler-Pasternak type. Classical beam theory (CBT) or Euler-Bernoulli beam theory (EBT) has been incorporated to address the displacement of the FG nanobeam. Bi-Helmholtz type of nonlocal elasticity is being used to capture the small scale effect of the FG nanobeam. Further, the...
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The AFM micrographs of gold nanoparticles on silicon substrate
Dane BadawczeThe dataset contains the first approach towards AFM topographic imaging of gold nanoparticles synthesized and immobilized on the silicon surface. Measurements were made in the semi-contact mode on the NTEGRA Prima device, manufactured by NT-MDT. Scans were performed with amplitude detection at an operating value of 60% of the free oscillation amplitude....
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SkinDepth - synthetic 3D skin lesion database
Dane BadawczeSkinDepth is the first synthetic 3D skin lesion database. The release of SkinDepth dataset intends to contribute to the development of algorithms for:
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Environmentally acceptable lubricants (EAL) compared with a reference mineral oil as marine stern tube bearing lubricant – Experimental and theoretical investigations
PublikacjaThe purpose of this research is to indicate the potential differences in bearing characteristics resulting from the application of different lubricant types with the same viscosity grade. The effect of different environmentally acceptable lubricants (EALs) on hydrodynamic journal bearing properties is studied experimentally and compared to the properties obtained after lubrication with a reference mineral oil. The results of the...
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A Quasi-2D MOSFET Model — 2D-to-Quasi-2D Transformation
PublikacjaA quasi-two-dimensional (quasi-2D) representation of the MOSFET channel is proposed in this work. The representation lays the foundations for a quasi 2D MOSFET model. The quasi 2D model is a result of a 2D into quasi 2D transformation. The basis for the transformation are an analysis of a current density vector field and such phenomena as Gradual Channel Detachment Effect (GCDE), Channel Thickness Modulation Effect (CTME), and...
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Sensitivity analysis of a composite footbridge
PublikacjaThis work include an example of sensitivity analysis for the design of a composite footbridge. A sandwich structure is used, consisting two high-strength skins separated by a core material. The analysis was conducted for two numerical models. The first one is a simple, single-span beam of a composite cross-section (laminate and foam), with different Young’s modulus for each material. Calculations were made by means of a MATLAB-based...
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Geometrically nonlinear FEM analysis of FGM shells based on neutral physical surface approach in 6-parameter shell theory
PublikacjaThe 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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Transformation of bimetallic Ag–Cu thin films into plasmonically active composite nanostructures
PublikacjaFormation of plasmonically active silver, copper and composite silver-copper nanostructures were studied in this paper. Metallic nanostructures were fabricated by thermal disintegration, so called dewetting, of the thin films in an argon atmosphere. The formation process of the nanostructures was in-situ observed by a novel method, based on resistance measurements. The influence of the material and thickness of the initial thin...
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Elastoplastic law of Cosserat type in shell theory with drilling rotation
PublikacjaWithin the framework of six-parameter non-linear shell theory, with strain measures of the Cosserat type, we develop small-strain J2-type elastoplastic constitutive relations. The relations are obtained from the Cosserat plane stress relations assumed in each shell layer, by through-the-thickness integration employing the first-order shear theory. The formulation allows for unlimited translations and rotations. The constitutive...
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Influence of titanium layer on counter electrode on electrical parameters of DSSC
PublikacjaIn this paper the influence of the Ti layer thickness at counter-electrode on electrical parameters of DSSCs was examined. The transparent conductive oxide – less (TCO-less) counter electrodes (CE) with titanium layers and platinum as catalyst on Bk7 glass were prepared. Thin metallic films were deposited by means of magnetron sputtering (titanium) and Pulsed Laser Deposition (platinum). The counter electrode with Pt layer on Fluorine...
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Low temperature deposition of dense MnCo 2 O 4 protective coatings for steel interconnects of solid oxide cells
PublikacjaIn this work manganese cobalt spinel (MnCo2O4) coatings were deposited on steel substrates by spray pyrolysis at 390 °C. This is at much lower temperatures than previously reported (typically in excess of 900 °C). It was possible to produce coatings with well controlled thickness (2-5-10 μm). The as-deposited coatings were evaluated for their microstructural changes and electrical conductivity up to 800 °C. Results confirm the...
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Annealing of indium tin oxide (ITO) coated optical fibers for optical and electrochemical sensing purposes
PublikacjaGlass and fiber structures with Indium Tin Oxide (ITO) coating were subjected to annealing in order to identify impact of the thermal treatment on their optical and electrochemical properties. It is shown that the annealing process significantly modifies optical properties and thickness of the films, which are crucial for performance of optical fiber sensors. Moreover, it visibly improves electrochemical activity of ITO on glass...
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A comprehensive study on nonlinear hygro-thermo-mechanical analysis of thick functionally graded porous rotating disk based on two quasi three-dimensional theories
PublikacjaIn this paper, a highly efficient quasi three-dimensional theory has been used to study the nonlinear hygro-thermo-mechanical bending analysis of very thick functionally graded material (FGM) rotating disk in hygro-thermal environment considering the porosity as a structural defect. Two applied quasi three-dimensional displacement fields are assumed in which the strain along the thickness is not zero unlike most of the other plate...
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The Impact Of The Selected Parameters Of Fdm Manufacturing Technology On Tribological Performance Of Abs–Steel Pair Under Dry Friction
PublikacjaThe paper presents the result of tribological test of ABS and steel samples sliding under dry friction. Polymeric samples were manufactured of ABS material using FDM technology. Testing was carried out in unidirectional sliding in a ring-on-flat contact in a PT-3 tribometer. The scope of tested parameters included volumetric and mass wear, the friction coefficient, and polymeric specimen temperature. Polymeric specimens used in...
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Measurement of temperature at sliding polymer surface by grindable thermocouples
PublikacjaThis paper is devoted to experimental study of capabilities and limitations of grindable thermocouples as applied to polymer materials sliding on metal. Chromel–alumel and chromel–copel grindable thermocouples have been developed and tested for wide ranges of contact pressure and sliding velocity. The background temperature of the sliding surface can be determined as the lower envelope of the signal from the grindable thermocouple....
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Determination of the refractive index and wavelength‐dependent optical properties of few‐layer CrCl3 within the Fresnel formalism
PublikacjaBased on previous reports on the optical microscopy contrast of mechanically exfoliated few layer CrCl3 transferred on 285 nmand 270 nmSiO2 on Si(100), we focus on the experimental determination of an effective mean complex refractive index via a fitting analysis based on the Fresnel equations formalism. Accordingly, the layer and wavelength-dependent absorbance and reflectance are calculated. Layer and wavelength-dependent optical...
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Flexomagneticity in Functionally Graded Nanostructures
PublikacjaFunctionally graded structures have shown the perspective of materials in a higher efficient and consistent manner. This study reports a short investigation by concentrating on the flexomagnetic response of a functionally graded piezomagnetic nano-actuator, keeping in mind that the converse magnetic effect is only taken into evaluation. The rule of mixture assuming exponential composition of properties along with the thickness...