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Search results for: HIGH-TEMPERATURE CREEP
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Numerical simulation of temperature distribution of heat flow on reservoir tanks connected in a series
PublicationThe flow of temperature distribution through a medium in thermodynamic studies plays an important role in understanding physical phenomena in chemical science and petroleum engineering, while temperature distribution indicates the degree of reaction that must be undergone to obtain the final product. Therefore, this paper aims to present and apply the exponential matrix algorithm (EMA), differential transformation algorithm (DTA),...
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Reliability of acicular grindable thermocouples for transient temperature measurements at sliding contacts
PublicationAcicular grindable thermocouples represent an interesting and prospective technique of temperature measurements at sliding contacts. This study aimed at the investigation of their reliability and accuracy as applied to the friction materials of various classes in contact with steel. The tests were conducted on a pin-on-disc tribometer under stationary and transient regimes. The experimental results were validated by comparing the...
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Identification of damages in the inlet air duct of a diesel engine based on exhaust gas temperature measurements
PublicationThe temperature of the exhaust gas of a diesel piston engine, measured in the characteristic control sections of its thermo-flow system, can be a valuable source of diagnostic information about the technical condition of the elements limiting the working spaces thus separated, including the turbocharging system, but also its fuel supply system and replacement of the medium. In standard marine engine measurement systems equipped...
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The effect of the temperature change rate on determination of the criticalpitting temperature of stainless steels
PublicationPrzedstawiono wyniki badań wpływu szybkości zmian temperatury na wyznaczaną krytyczną temperaturę korozji wżerowej. Badania stali 316L przeprowadzono metodą termometrii cyklicznej. Stwierdzono, że zwiększenie szybkości zmian temperatury związane jest ze zwiększeniem wyznaczonej temperatury krytycznej. Zależność krytycznej temperatury korozji wżerowej od szybkości korozji ma charakter liniowy. Wartości krytycznej temperatury korozji...
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Study of Soil Temperature and Moisture Changes in a Physical Model of an Underground Cable Line
PublicationThe ampacity of power cables is highly dependent on the thermal resistivity of the soil in which they are laid. The lower it is, the higher this ampacity. The thermal resistivity of the soil decreases as its moisture increases. Therefore, it is preferable that the soil around the cables has high moisture. Unfortunately, the heat generated in heavily loaded cables causes the migration of moisture from the surrounding soil, which...
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ZnO ALD-Coated Microsphere-Based Sensors for Temperature Measurements
PublicationIn this paper, the application of a microsphere-based fiber-optic sensor with a 200 nm zinc oxide (ZnO) coating, deposited by the Atomic Layer Deposition (ALD) method, for temperature measurements between 100 and 300°C, is presented. The main advantage of integrating a fiber-optic microsphere with a sensing device is the possibility of monitoring the integrity of the sensor head in real-time, which allows for higher accuracy during...
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Maturity curve for estimating the in-place strength of high performance concrete
PublicationThe paper presents the maturity curve for estimating the in-place early-age compressive strength of concrete. The development of appropriate maturity curve is a complex process. It is important to correctly determine the datum temperature and activation energy, which can be obtained in mortar tests. This paper describes an investigation of the accuracy of the maturity method to estimate the strength when different way to rate constant...
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INFLUENCE OF TEMPERATURE ON THE ACTIVITY OF ANAMMOX GRANULAR BIOMASS - SHORT AND LONG-TERM ASPECT
PublicationThe aim of this study was to determine a short-term and long-term effect of temperature on the anammox process rate and determination of temperature coefficients in the Arrhenius and Ratkowski equations. The short-term effects of temperature on the anammox biomass were investigated in batch tests at ten different temperatures in the range of 10-55 ̊C. The maximum rate 1.3 gN (gVSS·d)-1 observed at 40 ̊C. The minimum rate, close...
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The effect of elevated temperature on LCF damage growth in 2024AA – Experiment and modeling
PublicationThis paper presents the results of experimental low-cycle fatigue (LCF) tests conducted on EN-AW 2024 alloy in T3511 temper at 100 ◦C, 200 ◦C and 300 ◦C. The material’s basic fatigue characteristics were determined, such as fatigue life curve and cyclic strain curve. Both the hysteresis loop and nature of fracture surfaces obtained in macro- and microscopic observations (scanning electron microscope, SEM) were accounted for. The...
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Signal filtering method of the fast-varying diesel exhaust gas temperature
PublicationThe paper presents the problem of the impact of external distortions originating on laboratory test stands on the results of measurements of fast-varying diesel exhaust gas temperature. It has been stressed how significant the aspect of the test stand adaptation is during an experiment to ensure the smallest possible impact. This paper, however, focuses on the methods of mathematical processing of a signal recorded during experimental...
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Study of pH and temperature effect on lipophilicity of catechol-containing antioxidants by reversed phase liquid chromatography
PublicationLipophilicity of selected antioxidant phytochemicals, including flavonoids, phenolic acids and xanthonoids, was determined by reversed phase high performance liquid chromatography with UV detection (RP-HPLC-UV). The analyses run at different temperature and pH conditions in isocratic mode suggested that lipophilicity as distribution coefficient (logD) between aqueous and organic phase decreases with increasing temperature. For...
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Low temperature rotary Stirling engine: conceptual design and theoretical analysis
PublicationThe use of low-temperature energy sources for electricity generation demands a dual focus: a substantial enhancement in the efficiency of energy conversion devices and a reduction in system production costs. Particularly in scenarios where low-temperature energy sources are scarce, this factor can be pivotal in facilitating widespread adoption of such technologies. The Stirling engine emerges as a promising solution capable of...
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Sea surface temperature distribution during upwelling along the Polish Baltic coast
PublicationAmong over 150 maps of sea surface temperature in the Polish Baltic coastal region derived from satellite data during the warm period of the year (April-October) in 2000-2002, 41 cases were noted where its distribution showed characteristic features indicating the occurrence of coastal upwelling. The fundamental parameters of range, probability of occurrence and temperature modification caused by water from deeper sea layers...
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Effect of Temperature and Nanoparticle Concentration on Free Convective Heat Transfer of Nanofluids
PublicationA theoretical analysis of the influence of temperature and nanoparticle concentration on free convection heat transfer from a horizontal tube immersed in an unbounded nanofluid was presented. The Nusselt (Nu) number and heat transfer coefficient were parameters of the intensity of the convective heat transfer. For free convection, the Nu number was a function of the Rayleigh (Ra) number and Prandtl (Pr) number. The Rayleigh (Ra)...
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Analysis of unsteady flow forces on the thermowell of steam temperature sensor
PublicationIn this paper, 3D numerical analysis of unsteady flow forces acting on the measuring sheath of steam temperature is presented. According to that purpose, the CFD (Computation Fluid Dynamic [1]) approach has been used. The nonstationary of fluid acting on the measuring sheath such as: Strouhal frequency, amplitude of pressure, structure of vortex, peak of pressure, field of pressure, field of velocity etc. are studied analytically...
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The Effect of Calcination Temperature on Structure and Photocatalytic Properties of WO3/TiO2 Nanocomposites
PublicationSeries ofWO3/TiO2 nanocompositeswere obtained by hydrothermal method followed by calcination in the temperature range from 400∘C to 900∘C. The characteristics of photocatalysts by X-ray diffractometry (XRD), scanning electron microscope (SEM), and diffuse reflectance spectroscopy (DRS) showed that increasing the calcination temperature from 400 to 900∘C resulted in change of photocatalytic activity under UV-Vis light.Moreover,...
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Proton Conducting Ceramic Powder Synthesis by a Low Temperature Method
PublicationMolten salt synthesis (MSS) is a simple method for the preparation of ceramic powders with specific morphology. The main role of the molten salts is to increase the reaction rate and lower the reaction temperature. It occurs because of much higher mobility of reactants in the liquid medium than in the solid state. In this work the molten salt synthesis was applied to produce ceramic powders of La0995Ca0005NbO4 and BaCe09−xZrxY01O3....
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Carburization Behavior of High-Grade Pellets After Direct Reduction in Pure Hydrogen
PublicationCarburization is a critical aspect in the iron and steel industry as it significantly affects the mechanical and chemical properties of the final product. This study provides a comprehensive analysis of the carburization potential of high-grade quality iron ore pellets after direct reduction in pure hydrogen. The results show that the porosity of the pellets has a significant impact on the efficiency and success of the direct reduction...
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The effect of the temperature change rate on determination of the critical pitting temperature of stainless steels
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The influence of the substrate temperature on the preparation of DNA films for studies under vacuum conditions
PublicationExperiments were carried out to determine the dependence of the physical form of supercoiled DNA films on the initial temperature of the substrate. Such films are often used in irradiation experiments involving low energy particles, like electrons or photons. In order to obtain absolute values for cross sections for such experiments, the spatial distribution of the sample in the film has to be well estimated. These investigations...
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Electrochemical capacitor temperature fluctuations during charging/discharging processes
PublicationThepaperpresentsaproposalofusingadditionalstatisticalparameterssuchas:standarddeviation,variance, maximum and minimum increases of the observed value that were determined during measurements of temperature fields created on the surface of the tested electrochemical capacitor. The measurements were carriedoutusingthermographicmethodsinordertosupportassessmentoftheconditionofelectrochemical capacitorunderclassicdurabilitytestsbasedonmethodsofdeterminationofcapacityandequivalentseries...
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Fe3–xInSnxO6 (x = 0, 0.25, or 0.5): A Family of Corundum Derivatives with Sn-Induced Polarization and Above Room Temperature Antiferromagnetic Ordering
PublicationThree new double corundum derivative compounds, Fe3−xInSnxO6 (x = 0. 0.25, or 0.5), were synthesized at high pressure and temperature (6 GPa and 1400− 1450 °C). All of the compounds order antiferromagnetically well above room temperature (TN = 608, 532, and 432 K for x = 0, 0.25, and 0.5, respectively). The x = 0 phase crystallizes as centrosymmetric R3̅c, but the inclusion of closed-shell d10 Sn4+ induces x = 0.25 and 0.5 to crystallize...
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Temperature influence on tyre/road noise on poroelastic road surface based on laboratory measurements
PublicationThe temperature effect on measured tyre/road noise is very important phenomena as it may lead to significant errors in measurement results due to substantial influence of this parameter on the obtained values. It depends mainly on the particular tyre-road combination. It is different for dense and porous as well as for bituminous and cement concrete pavements. It differs also depending on tested tyre. The correction procedure for...
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A new viscoelastic method of calculation of low-temperature thermal stresses in asphalt layers of pavements
PublicationThe paper presents a new method of calculation of thermal stresses in asphalt layers of pavements induced by cooling or heating. The method, developed by the author, is based on the analytical solution for the linear viscoelastic Burgers model extended numerically for the case of asphalt layers whose rheological parameters are strongly dependent on temperature. The coefficient of thermal expansion and Poisson’s ratio may optionally...
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Low temperature broad band dielectric spectroscopy of multiferroic Bi6Fe2Ti3O18 ceramics
PublicationIn the present research the tool of broadband dielectric spectroscopy was utilized to characterize dielectric behavior of Bi6Fe2Ti3O18 (BFTO) Aurivillius-type multiferroic ceramics. Dielectric response of BFTO ceramics was studied in the frequency domain (Δν=0.1Hz – 10MHz) within the temperature range ΔT=-100°C – 200°C. The Kramers-Kronig data validation test was employed to validate the impedance data measurements and it was found...
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TEMPERATURE INFLUENCE ON TIRE ROLLING RESISTANCE MEASUREMENTS QUALITY
PublicationGlobal warming makes it necessary to reduce energy consumption, which in the case of motor vehicles, is connected, among other things, with reduction of resistive forces acting on a vehicle during its motion. One of the most important components of those forces is rolling resistance, which is very difficult to measure, especially in road conditions. The article deals with issues related to the influence of the thermal state of...
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Double-stage ORC system based on various temperature waste heat sources of the negative CO2 power plant
PublicationAnalysed is the modification of the thermodynamic cycle with the negative CO2 power plant concept by its combination with the organic Rankine cycle. The analysed power plant operates on a gas produced from the gasification of sewage sludge. The negative emission term comes from the aggregated CO2 balance resulting from the capture of the CO2, while the sewage sludge is one of the inevitable environmental sources of CO2 to be avoided....
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Failure analysis of a high-speed induction machine driven by a SiC-inverter and operating on a common shaft with a high-speed generator
PublicationDue to ongoing research work, a prototype test rig for testing high-speed motors/generators has been developed. Its design is quite unique as the two high- speed machines share a single shaft with no support bearings between them. A very high maximum operating speed, up to 80,000 rpm, was required. Because of the need to minimise vibration during operation at very high rotational speeds, rolling bearings were used. To eliminate...
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Performance of the PEM fuel cell module. Part 2. Effect of excess ratio and stack temperature
PublicationThe paper describes a fuel cell based system performance under different thermal conditions. The system could be fed with bottled hydrogen or with very high purity hydrogen obtained from reforming of methanol. The system is based on two fuel cell units (1.2 kW each, produced by Ballard Power Systems Inc. and called Nexa), DC/DC converter, DC/AC inverter, microprocessor control unit, load unit, bottled hydrogen supply system and...
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Low temperature growth of diamond films on optical fibers using Linear Antenna CVD system
PublicationIt is not trivial to achieve a good quality diamond-coated fibre interface due to a large difference in the properties and composition of the diamond films (or use coating even) and the optical fibre material, i.e. fused silica. One of the biggest problems is the high temperature during the deposition which influences the optical fibre or optical fibre sensor structure (e.g. long-period gratings (LPG)). The greatest advantage of...
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EXHAUST TEMPERATURE MEASUREMENTS OF THE MARINE TURBOCHARGED DIESEL ENGINES IN OPERATION
PublicationThe article presents the selected metrology issues concerning the exhaust temperature of the turbocharged marine engines during operation. The special concern has been paid on existing disturbances as well as thermodynamical interpretation of the recorded measurement signal. A diagnostic informativeness of the standard exhaust temperature’s measurements has worked out while the engine runs in steady states has been also considered...
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Determination of chlorine concentration using single temperature modulated semiconductor gas sensor
PublicationA periodic temperature modulation using sinusoidal heater voltage was applied to a commercial SnO2 semiconductor gas sensor. Resulting resistance response of the sensor was analyzed using a feature extraction method based on Fast Fourier Transformation (FFT). The amplitudes of the higher harmonics of the FFT from the dynamic nonlinear responses of measured gas were further utilized as an input for Artificial Neural...
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Influence of electropolymerization temperature on corrosion, morphological and electrical properties of PPy doped with salicylate on iron
PublicationIn this work, the influence of the electropolymerization temperature on corrosion, morphological and electrical properties of polypyrrole (PPy) film is studied. Polypyrrole is electrochemically synthesized on iron in the presence of sodium salicylate. The X-ray diffraction and scanning electron microscopy are performed in order to study the structure and morphology of electrodeposited PPy. The electroactive surface area, corrosion...
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Challenges in operating and testing loop heat pipes in 500–700 K temperature ranges
PublicationThe potential applications of loop heat pipes (LHPs) are the nuclear power space systems, fuel cell thermal management systems, waste heat recovery systems, medium temperature electronic systems, medium temperature military systems, among others. Such applications usually operate in temperature ranges between 500–700 K, hence it is necessary to develop an LHP system that will meet this requirement. Such a thermal management device...
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Influence of Operation Conditions on Temperature Hazard of Lithium-Iron-Phosphate (LiFePO4) Cells
PublicationThe article presents and discusses the results of research on hazard, especially temperature, for selected lithium-ion-phosphate cells operated in accordance with the manufacturer’s recommendations but used under onerous mining conditions. This applies to the performance of cells in battery sets without the application of any management system (BMS). On the basis of the obtained test results, first of all, the influence of the...
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Wavelet Transform Analysis of Temperature Modulated Gas Sensor Response
PublicationThe aim of the study was to evaluate whether it is possible to extract the information about the gas concentration despite the influence of humidity. Commercial semiconductor sensor response was examined under the application of a periodic temperature change. The data was collected using measurement protocol for different concentrations of ammonia at specified levels of relative humidity. In this work we focused on the evaluation...
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Temperature influences on shear stability of a nanosize plate with piezoelectricity effect
PublicationPurpose The purpose of this paper is to predict the mechanical behavior of a piezoelectric nanoplate under shear stability by taking electric voltage into account in thermal environment. Design/methodology/approach Simplified first-order shear deformation theory has been used as a displacement field. Modified couple stress theory has been applied for considering small-size effects. An analytical solution has been taken into account...
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GPU based implementation of Temperature-Vegetation Dryness Index for AVHRR3 Satellite Data
PublicationPaper presents an implementation of TVDI (Temperature-Vegetation-Dryness Index) algorithm on GPU (Graphics Processing Unit). Calculation of this index is based on LST (Land Surface Temperature) and NDVI (Normalized Difference Vegetation Index). Discussed results are based on multi-spectral imagery retrieved from AVHRR3 sensors for area of Poland. All phases of TVDI implementation on GPU are modified in respect to CUDA platform....
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Weldability of high strength steel in underwater environment
PublicationThe article describes the problems with weldability of high-strength steels in the aquatic environment. The tendency of steel S355J2G3 and S500M to form cold cracks when welded in wet welding conditions has been experimentally evaluated. It was found that the tested steels have a high propensity to cracking. An experiment has been proposed and tested to evaluate the usefulness of the tempering bead technique as a method of improving...
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The Microclimate in Protective Fire Fighter Footwear: Foot Temperature and Air Temperature and Relative Humidity
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Fatigue life improvement using low transformation temperature weld material with measurement of residual stress
PublicationWelding processes often produce high levels of tensile residual stress. Low transformation temperature (LTT) welding wires utilise phase transformation strains to overcome the thermal contraction of a cooling weld. In this paper, the residual stress within each weld was quantified using the milling/strain gauge method, being the strain change measured as the weldment was milled away. The fatigue tests were conducted under uniaxial...
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Impact of Temperature and Nanoparticle Concentration on Turbulent Forced Convective Heat Transfer of Nanofluids
PublicationTheoretical analysis of the influence of nanoparticles and temperature on the average Nusselt (Nu) number and the average heat transfer coefficient (HTC) during the turbulent flow of nanofluid in a horizontal, round tube was carried out. The Nu number is a function of the Reynolds (Re) number and the Prandtl (Pr) number, which in turn are functions of the thermophysical properties of the liquid and the flow conditions. On the other...
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Highly crystalline colloidal nickel oxide hole transport layer for low-temperature processable perovskite solar cell
PublicationHighly crystalline NiOX usually requires high annealing temperature (>300 °C) which is incompatible with flexible substrate and might consume high amount of energy. Herein, we demonstrate a facile emulsion process to synthesize highly crystalline, low temperature deposition (<150 °C) and solution processable NiOx nanoparticles (NPs) as a hole transport layer for the perovskite solar cells (PVSCs). A novel surfactant of tetramethylammonium...
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High-throughput Evaluation of Lipophilicity and Acidity by New Gradient HPLC Methods
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Inverse determination of sliding surface temperature based on measurements by thermocouples with account of their thermal inertia
PublicationThis study developed an inverse heat conduction algorithm to determine temperature at a sliding surface taking account of thermocouple thermal inertia. The direct heat conduction problem was solved analytically based on the Laplace integral transform approach. The inverse algorithm was applied to the problem of friction of a brake material against a steel. The experiments were conducted on a pin-on-disc tribometer for three short-time...
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X-Ray Computer Tomography Study of Degradation of the Zircaloy-2 Tubes Oxidized at High Temperatures
PublicationThe investigations of high-temperature oxidation of zirconium alloys, applied for fuel pellets in nuclear power plants, are usually limited to oxidation kinetics, phase transformations and microstructural characterization. The purpose of this research was to characterize the degradation phenomena occurring within oxide layer and at the interface oxide/metal, on internal and external Zircaloy-2 tube...
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Impact of temperature on optical sensing in biology based on investigation of SARS‐CoV ‐2
PublicationIn this paper, we present an investigation of the influence of the temperature on the sensing of biological samples. We used biofunctionalized microsphere-based fiber-optic sensor to detect immunoglobulin G attached to the sensor head at temperatures relevant in biological research: 5°C, 25°C, and 55°C. The construction of the sensor allowed us to perform measurements in the small amount of solution. The results of our experiment...
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Measurement of the Temporal and Spatial Temperature Distribution on the Surface of PVCP Tissue Phantom Illuminated by Laser Dataset
PublicationThe dataset entitled Measurement of the temporal and spatial temperature distribution on the surface of PVCP tissue phantom illuminated by laser was obtained with a laboratory set-up for characterisation of the thermal properties of optical tissue phantoms during laser irradiation. The dataset contains a single image file representing the spatial temperature distribution on the surface of a PVCP tissue phantom. This thermal image...
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Influence of e-beam irradiation on the dynamic creep and fatigue properties of poly(aliphatic/aromatic-ester) copolymers for biomedical applications
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Influence of cooling rate and additives on low-temperature properties of asphalt mixtures in the TSRST
PublicationThe paper presents the results and analysis of low-temperature properties of asphalt mixtures according to Thermal Stress Restrained Specimen Test (TSRST) and Indirect Tensile Test methods. Different groups of bitumen were investigated: neat, SBS-modified and highly SBS-modified. Influence of cooling rates (1 C/h, 3 C/h, 5 C/h and 10 C/h) and additives (aramid fibres and crumb rubber) was identified as well. Moreover, for each...