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Novel fast non-linear electrochemical impedance method for corrosion investigations
PublicationThe paper presents a novel approach to corrosion rate monitoring using non-linear electrochemical impedance spectroscopy. The authors propose a new variant of non-linear impedance measurement using amplitude-modulated multi-frequency ac perturbation signal. It allows shortening of measurement duration so it is possible to monitor corrosion rate of the systems experiencing rapid changes. In this way a limitation resulting from lack...
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Use of pyridinium and pyrrolidinium ionic liquids for removal of toluene from gas streams
PublicationSeparation of toluene from a toluene/N2 gas mixture using supported liquid membranes based on a series of pyridinium (1-butylpyridinium- bis(trifluoromethylsulfonyl)imide - [C4Py][Tf2N], 1-hexylpyridinium trifluoromethanesulfone [C6Py][Tf2N]) and pyrrolidinium (1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide - [C4Pyrr][Tf2N], 1-hexyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide - [C6Pyrr][Tf2N], 1-butyl-1-methylpyrrolidinium...
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Recent advances in electrochemically surface treated titanium and its alloys for biomedical applications: A review of anodic and plasma electrolytic oxidation methods
PublicationNowadays, titanium and its alloys are widely used materials in implantology. Nevertheless, the greatest challenge is still its appropriate surface treatment in order to induce optimal properties, which facilitates formation of a permanent bond between the implant and human tissue. The use of electrochemical treatment such as anodic oxidation or plasma electrolytic oxidation allows for the production of porous coating that mimics...
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Properties of Composite Oxide Layers on The Ti13Nb13Zr Alloy
PublicationThe development of composite oxide layers on the Ti13Nb13Zr alloy, their structure and properties have been demonstrated. Two subsequent methods were applied to prepare the composite layers. During the first stage gas oxidation produced a solid oxide layer, and subsequently oxide nanotubes were produced by using an electrochemical method. Scanning electron microscopy (SEM), chemical analysis, energy dispersive X-ray spectroscopy...
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Point cloud based surface analysis of prestressed concrete element in exceeded state of serviceability
PublicationBy definition, serviceability state is characterized by the fact that despite meeting the requirements associated with carrying capacity, the object is not suitable for use. Serviceability limit state refers to factors, such as durability, overall stability, fire resistance, cracking, excessive vibration. Perfect examples of exceeded serviceability state are the improper vibration of a skyscraper, which inhabitants may suffer from...
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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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Mechanical Behavior of Bi-Layer and Dispersion Coatings Composed of Several Nanostructures on Ti Substrate
PublicationThree coatings suitable for biomedical applications, including the dispersion coating composed of multi-wall carbon nanotubes (MWCNTs), MWCNTs/TiO2 bi-layer coating, and MWCNTs-Cu dispersion coating, were fabricated by electrophoretic deposition (EPD) on Ti Grade II substrate. Optical microscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and nanoindentation were applied to study topography, chemical, and...
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Navier number and transition to turbulence
PublicationThe motivation behind this article is to explain a role of the Navier number (Na -dimensionless slip-length) in prediction of closures for laminar to turbulent transition undergoing via eddies detachment from the slip layer in nano-cannals. Additionally the role of the Navier number Na in universal modeling of phenomenon of enhanced mass flow rate reported in micro- and nano-channels has been explained. The Na number should be...
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High temperature oxidation behavior of SUS430 SOFC interconnects with Mn-Co spinel coating in air
PublicationIn this study, SUS430 alloy is evaluated for its high temperature corrosion properties as a possible material for interconnects of solid oxide fuel cells (SOFCs). Samples are coated with Mn-Co by commercial physical vapor deposition (PVD) process and oxidized in air for 1250 h at 800 °C. A dense cubic Mn-Co-Fe spinel layer is formed on the surface, showing great effect on corrosion reduction compared with the samples without coating....
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Numerical analysis of the container vessel's self-propulsion at different rudder deflection angles
PublicationNowadays, CFD becomes one of the most commonly used research method in ship hydrodynamics, limited to the analyses of hull resistance in calm water. With continuously improving computing power and increasingly more accurate numerical methods it is possible to simulate more complex cases. State of the art CFD tools also enable development of new ways of assessing ship maneuvering performance. This paper presents an attempt on using...
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Verification of safety in low-voltage power systems without nuisance tripping of residual current devices
PublicationLow-voltage power systems require initial and periodical verification to check the effectiveness of protection against electric shock. As a protection in case of fault, automatic disconnection of supply is most often used. To verify such a protection measure, the earth fault loop impedance or resistance is measured. This measurement is easy to perform in circuits without residual current devices. When residual current devices are...
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Polymer biodegradable coatings as active substance release systems for urological applications
PublicationCatheter-associated urinary tract infections are the result of catheterization of the bladder. The risk of infection is directly proportional to the length of the bladder catheterization. Bacteria cells have the ability to adhere and create the biofilm on the surface of catheter materials. Bacteria’s biofilm is an extremely beneficial environment of existence for microorganisms. Microorganisms that are an integral part of the biofilm...
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Stability of thin film diamond mirror for applications in interferometers under the short-time exposure on selected aggressive chemicals
PublicationIn presented study a thin boron-doped diamond film was proposed for application in the interferometry as a highly durable optical mirror. The unique properties of the diamond films, like high chemical stability and hardness, allow them to be used even in the chemically aggressive environment, where the commonly used silver mirrors can be susceptible to damage. The investigated nanodiamond layer was fabricated by uPE CVD method...
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Stability and load bearing capacity of a braced truss under upward wind loading
PublicationThe paper is focused on the numerical and experimental investigation of stability of a steel truss under upward wind loading. The structure was stiffened by elastic braces situated at the top and bottom chord. Usually the lateral (translational) brace stiffness is considered. However, the rotational stiffness of braces caused by interaction between torsional stiffness of the truss top chord and bending stiffness of the roof elements...
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Stability and load bearing capacity of a braced truss under upward wind loading
PublicationThe paper is focused on the numerical and experimental investigation of stability of a steel truss under upward wind loading. The structure was stiffened by elastic braces situated at the top and bottom chord. Usually the lateral (translational) brace stiffness is considered. However, the rotational stiffness of braces caused by interaction between torsional stiffness of the truss top chord and bending stiffness of the roof elements...
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Application of electrochemical impedance spectroscopy to monitoring discharging process of nickel/metal hydride battery.
PublicationThis paper presents the possibility of applying impedance analysis to cell diagnostics. In order to obtain characteristic curves of both electrodes of a NiMH battery simultaneously, a reference electrode was added into the circuit. The authors analysed the cell under three cases, i.e. when its properties are determined only by the state of the positive electrode, only by the state of the negative electrode, or when both electrodes...
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Biofilm formation and its regulation in Staphylococcus aureus
PublicationInfections caused by the major human and animal pathogen, Staphylococcus aureus are becoming an important problem due to its emerging resistance mechanisms and variety of virulence factors. Biofilm formation is considered to be one of the most important factor attributed to high pathogenicity of S. aureus. Described in the literature methods used in identification of biofilm forming abilities of bacteria consist of phenotypic and...
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Application of fracture mechanics for energetic effects predictions 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, cutting forces (power) could be considered from a point of view of modern fracture mechanics. Cutting forces may be employed to determine not only toughness...
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Influence of friction stir welding technological parameters on the properties of the joints of selected aluminum alloys
PublicationThe purpose of this dissertation was to determine the effect of friction stir welding technological parameters on the properties of selected aluminum alloy joints, with consideration of the residual stresses and dislocation density in the joints. The goal of the present work was also to produce defect-free joints with high mechanical and electrochemical properties. In the dissertation, similar welds of AA6082 alloy and dissimilar...
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Pressure drop of HFE7000 and HFE7100 during flow condensation in minichannels
PublicationAttention is focused on the issues of flow resistance and pressure drop of perspective refrigeration fluids during condensation in the two-phase flow in minichannels. The case of the flow through a cylindrical single channel of 2.3 mm inner diameter was carefully analyzed. Pressure drop tests have been performed in diabatic flow conditions. The effect of heat flux, mass flux, vapour quality and saturation temperature on the two-phase...
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Highly stable organic–inorganic junction composed of hydrogenated titania nanotubes infiltrated by a conducting polymer
PublicationA poly(3,4-ethylenedioxythiophene) conducting polymer doped with poly(2-styrene sulfonate) (pEDOT:PSS) was efficiently electrodeposited on a layer composed of ordered titania nanotubes. TiO2 nanotubes were formed during an anodization process and, after calcinations, a layer was subjected to hydrogen plasma. Hydrogenation leads to Ti(III) formation, a decrease in resistance, and a huge increase of donor density when compared with...
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Numerical Modelling of Forced Convection of Nanofluids in Smooth, Round Tubes: A Review
PublicationA comprehensive review of published works dealing with numerical modelling of forced convection heat transfer and hydrodynamics of nanofluids is presented. Due to the extensive literature, the review is limited to straight, smooth, circular tubes, as this is the basic geometry in shell-and-tube exchangers. Works on numerical modelling of forced convection in tubes are presented chronologically in the first part of the article....
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Transformational Leadership and Acceptance of Mistakes as a Source of Learning: Poland-USA Cross-Country Study
PublicationThis study explores the influence of transformational leadership on internal innovativeness mediated by mistakes acceptance, including country and industry as factors to be considered and gender and risk-taking attitude as moderators. General findings, primarily based on the US samples (healthcare, construction, and IT industry), confirmed that transformational leadership and internal innovativeness are mediated by mistakes acceptance...
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A 0.5 V Nanowatt Biquadratic Low-Pass Filter with Tunable Quality Factor for Electronic Cochlea Applications
PublicationA novel implementation of an analogue low-power, second-order, low-pass filter with tunable quality factor (Q) is presented and discussed. The filter feature is a relatively simple, buffer-based, circuit network consisting of eleven transistors operating in a subthreshold region. Q tuning is accomplished by injecting direct current into a network node, which changes the output resistance of the transistors and, as a result, modifies...
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Multiscalar Control Based Airgap Flux Optimization of Induction Motor for Loss Minimization
PublicationBased on the induction motor model, considering the core loss resistance that accounts for magnetic characteristic saturation, a speed control approach is devised with an adaptive full-order (AFO) speed observer. The induction motor model analysis is done sincerely in a stationary reference frame. The control approach incorporates a flux reference generator designed to meet optimal operational circumstances and a nonlinear speed...
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Analysis of ring cracks in ceramic rolling elements using the boundary element method
PublicationCeramic materials have been increasingly used in bearing technology for over a dozen years. This is due to the characteristic properties of ceramic materials such as: high hardness, corrosion resistance, the possibility of use in aggressive chemical environments, as well as due to the lower specific weight compared to steel materials. However, the use of ceramic materials is connected with many limitations. The main disadvantages...
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Dynamiczna aplikacja Internetowa ASP.NET silnika indukcyjnego jako elementu wirtualnego laboratorium maszyn elektrycznych
PublicationTematem referatu jest dynamiczna aplikacja internetowa, która umożliwia symulację obwodową silnika indukcyjnego trójfazowego Sg 100 L2 z wykorzystaniem interfejsu przeglądarki WWW. Model matematyczny silnika jest zdefiniowany w tzw. osiach naturalnych i sformułowany na podstawie metody energetycznej Lagrange’a. Do implementacji modelu maszyny w aplikacji internetowej wybrano projekt typu Web Forms, który jest składnikiem środowiska...
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Wyznaczanie współczynnika przejmowania ciepła podczas wrzenia w przepływie dwutlenku węgla (Prediction of flow boling heat transfer coefficient for carbon dioxide in minichannels)
PublicationW pracy przedstawiono wyniki obliczeń uzyskane za pomocą własnego modelu półemirycznego dla wybranych danych eksperymentalnych dla wrzenia w przepływie dwutlenku węgla. Metoda obliczeniowa została zweryfikowana z danymi eksperymentalnymi Docoulombiera i innych (2011) oraz Mastrullo i innych (2009). Badania eksperymentalne dotyczą pełnego zakresu zmienności stopnia suchości oraz zakresu prędkości masowej G=200-1200 kg/m2s. rozwijany...
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Poroelastic Road Surfaces - State of The Art
PublicationPoroelastic Road Surfaces (PERS) constitute a specific group of pavements containing a great amount of crumbled rubber. In most cases rubber aggregate constitutes about 20% of the mixture (by weight) and a polyurethane resin is used as a binder. As a result, PERS is characterized by a much higher elasticity than asphalt and a high porosity typical for drainage pavements. Due to this, tire/road noise is greatly reduced and on top...
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Visualizing Carotid Bodies With Doppler Ultrasound Versus CT Angiography: Preliminary Study
PublicationOBJECTIVE. The purpose of this article is to evaluate the utility of ultrasound in identifying carotid bodies (CBs) in patients with drug-resistant arterial hypertension. SUBJECTS AND METHODS. We enrolled 13 patients with drug-resistant hypertension into a trial for surgical CB excision. CT angiography (CTA) and Doppler ultrasound (DUS) of the cervical arteries were performed before surgery. CBs were identified in a blind manner...
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Rigid finite elements and multibody modeling in analyses of a robot shaped elastic/plastic deformations of a beam
PublicationDynamics analysis of a system composed of a parallel manipulator and of an elastic beam is presented in the paper. Classic 3RRR parallel manipulator is considered and used to deform the beam. Elasto-plastic deformations are investigated. Rigid-finite-elements technique is employed to deal with dynamics of the beam. A multibody structure is associated with the introduced hybrid system in order to model its dynamics. Idea of the...
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The Chemical and Biological Properties of Nanohydroxyapatite Coatings with Antibacterial Nanometals, Obtained in the Electrophoretic Process on the Ti13Zr13Nb Alloy
PublicationThe risk of an early inflammation after implantation surgery of titanium implants has caused the development of different antimicrobial measures. The present research is aimed at characterizing the effects of nanosilver and nanocopper dispersed in the nanohydroxyapatite coatings, deposited on the Ti13Zr13Nb alloy, and on the chemical and biological properties of the coatings.The one-stage deposition process was performed by the...
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Reduction of road traffic noise by source measures — present and future strategies
PublicationThe current trend worldwide is less focused on reducing road traffic noise. This is in strong contrast to the severe impact of traffic noise to the general health and quality of life. A more holistic and combined strategy is needed. Current international rules and regulations regarding vehicles and tyres are not sufficient to reduce traffic noise levels in an effective way. Calculations show that these regulations will only yield...
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Electrodeposited Biocoatings, Their Properties and Fabrication Technologies: A Review
PublicationCoatings deposited under an electric field are applied for the surface modification of biomaterials. This review is aimed to characterize the state-of-art in this area with an emphasis on the advantages and disadvantages of used methods, process determinants, and properties of coatings. Over 170 articles, published mainly during the last ten years, were chosen, and reviewed as the most representative. The most recent developments...
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The buckling analysis of a cold-formed steel C-sectional column resting on an elastic foundation
PublicationThe paper is focused on stability analysis of different models of steel cold-formed C-section column. The analysed element may be applied as a primary load-bearing member in steel trusses or silo columns. The column can be used as a support for a wall of roof plates made of corrugated sheets. The wall sheeting that restrains the column against buckling may be considered as an elastic foundation. Due to the design solutions the...
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Thermal decomposition kinetics of dynamically vulcanized polyamide 6-acrylonitrile butadiene rubber-halloysite nanotube nanocomposites
PublicationThermally stable thermoplastic elastomer nanocomposites based on polyamide 6 (PA6), acrylonitrile butadiene rubber (NBR), and halloysite nanotubes (HNTs) were dynamically vulcanized, and their nonisothermal decomposition kinetics were examined. The Friedman, Kissinger–Akahira–Sunose (KAS), Ozawa–Wall–Flynn (FWO), and modified Coats–Redfern (m‐CR) isoconversional models were used to obtain information about the kinetics of the thermal...
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A Simplified Method of Trend Removal to Determine Noise Observed During a Supercapacitor’s Discharging
PublicationIn this paper, new method of trend removal is proposed. This is a simplified method based on Empirical Mode Decomposition (EMD). The method was applied for voltage time series observed during supercapacitor discharging process. It assured the determination of an additive noise component after subtracting the identified trend component. We analyzed voltage time series observed between the terminals of the supercapacitor when discharged...
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Light intensity analysis of photovoltaic parameters for perovskite solar cells
PublicationThe number of publications on perovskite solar cells (PSC) continues to grow exponentially. Although the efficiency of PSC is exceeded 25.5%, not every research laboratory can reproduce this result or even pass the border of 20%. Unfortunately, it is not always clear which dominating mechanism is responsible for the performance drop. Here, we develop a simple method of light intensity analysis of JV parameters allowing the understanding...
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Designate of CTOD for WM and HAZ, report no: WOiO/II/122/2014
PublicationTypical (normative) testing of materials and/or welded joints do not answer on all questions about material or welded joint properties. In ship building and off-shore sectors, many strucures requires materials and joint with higher than typical fatigue resistance. Imact tests, which are carried out during welding technology qualification, gives answer about ductility, CTOD tests results about material or welded joint ability to...
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Investigation of thin perovskite layers between cathode and doped ceria used as buffer layer in solid oxide fuel cells
PublicationIn this paper, thin perovskite layers between cathode material of solid oxide fuel cells and gadolinia-doped ceria buffer layer are investigated. Thin layers made of LaNi0.6Fe0.4O3-δ (LNF), La0.6Sr0.4Co0.2Fe0.8O3-δ (LSCF), or SrTi0.65Fe0.35O3-δ (STF) were symmetrically deposited by spin coating method from metallo-organic polymer precursors on a Ce0.8Gd0.2O2-δ (CGO) substrate. Porous and about 40-μm-thick LNF cathodes were deposited...
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The effect of tire aging on acoustic performance of CPX reference tires
PublicationReduction of tire/road noise is one of the biggest environmental challenges of road traffic. To reduce that noise it is necessary to perform acoustic measurements on the base of wellproven standard procedures. One method of measurements that is in common use, namely the Close Proximity Method (CPX), is described in standard ISO-DIS 11819-2. As this method is used to classify road surfaces regarding their influence on vehicle noise,...
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Application of Fracture Mechanics for Energetic Effects Predictions 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, cutting forces (or power - more interesting from energetic point of view) could be considered from a point of view of modern fracture mechanics. Cutting...
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HOW EFFICIENT IS NOISE LABELING OF TIRES?
PublicationSince 2012 all new tires in Europe must be labeled. The label contains general information about tire performance concerning rolling resistance (that corresponds to fuel economy), noise emission and wet grip (only for passenger car tires). Measurements of noise performance of tires must be performed according to the Annex 3 of the Regulation No 117 of the Economic Commission for Europe of the United Nations. The regulation specifies...
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Designate CTOD of Weld Metal of butt weld, No WOiO/II/108/2013
PublicationTypical (normative) testing of materials and/or welded joints do not answer on all questions about material or welded joint properties. In ship building and off-shore sectors, many strucures requires materials and joint with higher than typical fatigue resistance. Imact tests, which are carried out during welding technology qualification, gives answer about ductility, CTOD tests results about material or welded joint ability...
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Designate CTOD Heat Affected Zone of butt weld, Report No: WOiO/II/76/2013
PublicationTypical (normative) testing of materials and/or welded joints do not answer on all questions about material or welded joint properties. In ship building and off-shore sectors, many strucures requires materials and joint with higher than typical fatigue resistance. Imact tests, which are carried out during welding technology qualification, gives answer about ductility, CTOD tests results about material or welded joint ability...
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Evaluation of Thermal Stresses in Asphalt Layers in Comparison with TSRST Test Results
PublicationThe paper presents the results of calculations and laboratory determination of thermal stresses at low temperatures. The modified Hills and Brien's method was used to calculate the thermal stresses in asphalt layers of pavements and the results were compared against the values obtained at a laboratory with the Thermal Stress Restrained Specimen Test (TSRST) method. The laboratory investigations were conducted using plain grade...
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Auxetic foams
PublicationThis paper presents a method of producing auxetic polyurethane foams (PUFs) and their unique properties. The experience was based on a synthesis of traditional flexible polyurethane foam and thermal conversion to auxetic foam. The foam specimens were transformed from conventional Poisson's ratio to auxetic (negative Poisson's ratio) [1]. Basic research was performed to determine the mechanical properties and cell structure. Auxetic...
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Distribution of relaxation times as a method of separation and identification of complex processes measured by impedance spectroscopy
PublicationImpedance spectroscopy is one of the most commonly performed measurements to characterize electronic and electrochemical systems. Impedance spectra have limited resolution and many different processes may overlap what could be the reason of obstructions in its proper later analysis. Up to date, there are three approaches to solve this problem: examining impedance spectra itself, fitting spectra with equivalent circuits, and calculating...
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EXPERIMENTAL RESEARCH ON INFLUENCE OF THE FUEL NOZZLE GEOMETRY ON THE FUEL CONSUMPTION OF THE MARINE 4-STROKE DIESEL ENGINE
PublicationThe article presents experimental research that has been carried out on a marine, 4-stroke, 3-cylinder, turbocharged engine. During testing, the engine operated at a constant rotational speed of 750 rpm and a load from 0 kW to 280 kW. The engine was fuelled by diesel oil of known specification and loaded by electric generator with water resistance. The fuel consumption was measured during the engine operation with fuel nozzles...
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CPTU/DMT control of heavy tamping compaction of sands
PublicationHeavy tamping compaction method in cohesionless alluvial soil was evaluated with CPTU and DMT tests. Some examples of interpretation of soundings in pre-treated and compacted sands are given. The compaction work was performed in two stages. Compaction control was performed after each stage of tamping. Additional tests were performed two weeks after the compaction works completion to study the set-up effect. While typical increase...