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Wyniki wyszukiwania dla: LOW TEMPERATURE CRACKING
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Low Cost Method for Location Service in the WCDMA System
PublikacjaA new and low cost method for a location service (LCS) in the Wideband Code Division Multiple Access (WCDMA) system is outlined. This method, which is called TDOA + RTT, enables calculation of the geographical position of a mobile station (MS) without knowledge of relative time differences (RTDs) between base stations (BSs). The TDOA+RTT method is based on the measurement of round trip times (RTTs) between the MS and the serving...
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Low cost electrochemical sensor module for measurement of gas concentration
PublikacjaThis paper describes a low cost electrochemical sensor module for gas concentration measurement. A module is universal and can be used for many types of electrochemical gas sensors. Device is based on AVR ATmega8 microcontroller. As signal processing circuit a specialized integrated circuit LMP9l000 is used. The proposed equipment will be used as a component of electronic nose system employed for classifying and distinguishing...
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Spectroscopic and photophysical properties of ZNTPP in a room temperature ionic liquid
PublikacjaThe steady-state absorption and emission spectra and the time-resolved Soret- and Q-band excited fluorescence profiles of the model metalloporphyrin, ZnTPP, have been measured in a highly purified sample of the common room temperature ionic liquid, [bmim][PF(6)]. S(2)-S(0) emission resulting from Soret-band excitation behaves in a manner completely consistent with that of molecular solvents of the same polarizability. The ionic...
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A new procedure for the determination of distillation temperature distribution of high-boiling petroleum products and fractions
PublikacjaThe distribution of distillation temperatures of liquid and semi-fluid products, including petroleum fractions and products, is an important process and practical parameter. It provides information on properties of crude oil and content of particular fractions, classified on the basis of their boiling points, as well as the optimum conditions of atmospheric or vacuum distillation. At present, the distribution of distillation temperatures...
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Low-frequency tripping characteristics of residual current devices
PublikacjaFast development of various types of converters makes their utilization in industry and in domestic installations very common. Due to converters, an earth fault current waveform in modern circuits can be distorted or its frequency can be different than 50/60 Hz. Frequency of earth fault (residual) current influences tripping of residual current devices which are widely used in low voltage systems. This paper presents the behaviour...
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Low-Level Music Feature Vectors Embedded as Watermarks
PublikacjaIn this paper a method consisting in embedding low-level music feature vectors as watermarks into a musical signal is proposed. First, a review of some recent watermarking techniques and the main goals of development of digital watermarking research are provided. Then, a short overview of parameterization employed in the area of Music Information Retrieval is given. A methodology of non-blind watermarking applied to music-content...
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Rotational Molding of Linear Low-Density Polyethylene Composites Filled with Wheat Bran
PublikacjaApplication of lignocellulosic fillers in the manufacturing of wood polymer composites (WPCs) is a very popular trend of research, however it is still rarely observed in the case of rotational molding. The present study aimed to analyze the impact of wheat bran content (from 2.5 wt.% to 20 wt.%) on the performance of rotationally-molded composites based on a linear low-density polyethylene (LLDPE) matrix. Microscopic structure...
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Vernacular and low-tech technologies in humanitarian architecture on the example of Senegal
PublikacjaHumanitarian architecture belongs to the broader trend of socially engaged architecture, whose main goal is to introduce new values to the quality of life of particular communities. Specifically, humanitarian architecture deals with aid to poverty-stricken communities. The context of economic constraints poses a particular challenge to architects and builders. It is a matter of natural necessity to look for cheap, locally available...
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Effect of temperature change on refractive index of an egg white and yolk: a preliminary study
PublikacjaIn this article, the refractive index of an egg white and yolk depending on temperature in range 30 - 47 °C over 1550 nm was determined. The measurement head was constructed as fiber optic Fabry-Perot interferometer with interference between polished fiber end-face and aluminum weighing dish. The measurement setup has been made of an optical spectrum analyzer, a superluminescent diode with a central wevelength of 1550 nm, 2:1 fiber...
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Moisture content during and after high- and normal-temperature drying processes of wood
PublikacjaThe aim of the article is to present the results of moisture content of wood during and after the high-temperature steam and air–steam mixture drying processes and after an open air-drying process. The knowledge of moisture content changes of wood in the process of its drying is one of the important parameters to economy drying process and to keep the quality of dried wood. Wood samples, namely, spruce (Picea abies K.) and beech...
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Theoretical examination of the fracture behavior of BC3 polycrystalline nanosheets: Effect of crack size and temperature
Publikacja2D carbon graphene nanostructures are elements of advanced materials and systems. This theoretical survey provides explanation to the mechanical and fracture behavior of mono- and polycrystalline BC3 nanosheets (denoted as MC- and PCBC3NS, respectively) as a function of temperature and the type of crack defects. The mechanical performance of PCBC3NS at elevated temperatures was monitored varying the number of grain boundaries (the...
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Improving voltage levels in low-voltage networks with distributed generation – case study
PublikacjaThe use of distributed generation in low-voltage networks may cause the voltage variation in them, within the wide range. In unfavourable circumstances, the voltage may reach unacceptable values. The paper presents the effect of distributed generation on voltage levels in a selected low-voltage rural distribution network in Poland. An analysis of possible methods for improving voltage levels in this network is conducted. The most...
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Low energy elastic scattering of electrons from hexafluoropropene (C3F6)
PublikacjaWe present cross sections from a joint experimental and theoretical study on elastic electron scattering from hexafluoropropene (C3F6) in the gas phase. The experimental results, using low energy electron spectroscopy, were obtained at incident electron energies of 0.5, 1, 1.5, 2, 3, 4, 5, 6, 10, 12, 15 and 20 eV, for scattering angles ranging from 10°to 130°. The theoretical method used in the computation of the integral, momentum...
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Low energy elastic electron scattering from benzonitrile (C6H5CN)
PublikacjaWe present experimental differential elastic scattering cross sections (DCSs) for low energy electron scattering from benzonitrile along with integral and momentum-transfer cross sections that are determined from these DCSs. The measurements of DCSs are obtained using the relative flow method with helium as the standard gas, in a crossed electron-molecular gas beam arrangement. Our measurements are made at incident electron energies...
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High-Temperature Oxidation of Heavy Boron-Doped Diamond Electrodes: Microstructural and Electrochemical Performance Modification
PublikacjaIn this work, we reveal in detail the effects of high-temperature treatment in air at 600 °C on the microstructure as well as the physico-chemical and electrochemical properties of boron-doped diamond (BDD) electrodes. The thermal treatment of freshly grown BDD electrodes was applied, resulting in permanent structural modifications of surface depending on the exposure time. High temperature affects material corrosion, inducing...
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Low speed permanent magnet synchronous generator for vertical axis wind turbine
PublikacjaThe paper presents design process and tests of a prototype low speed permanent magnet synchronous generator (PMSG) dedicated for the innovative vertical-axis wind turbine. The rated data of the designed generator are following: power - 15 kVA, voltage - 400 V (Y), rotation speed - 93.75 rpm. The design assumptions, chosen results of the design process and experimental tests of the prototype PMSG are presented. The considered PMSG...
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Low-fidelity model considerations for simulation-based optimisation of miniaturised wideband antennas
PublikacjaHere, variable-fidelity electromagnetic (EM)-based design optimisation of miniaturised antennas is discussed. The authors focus on an appropriate selection of discretisation density of the low-fidelity EM model, which results in good performance of the optimisation algorithm in terms of its computational complexity and reliability. Trust-region gradient search with low-fidelity model corrected by means of non-linear frequency scaling...
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High Temperature Corrosion Evaluation of Porous Hastelloy X Alloy in Air and Humidified Hydrogen Atmospheres
PublikacjaIn this work a commercially available porous Hastelloy X alloy is characterized in terms of high temperature corrosion resistance. The alloy was oxidized in the temperature range from 500C to 900C in air and humidified hydrogen for 100 hours. Corrosion rates and porosity changes were measured. Microstructural characterization was performed using X-ray diffractometry and scanning electron microscopy. Results show that porous alloys...
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Shear resistance of low height precast concrete lintels
PublikacjaThe scope of the paper is to investigate analytically and determine experimentally the shear resistance of low height reinforced precast concrete lintels. The chosen procedures included in national and international standards applied for the design of structural concrete elements to an estimation of shear behaviour of reinforced concrete elements are described. The characteristic and designed shear strength of precast concrete...
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A review of design approaches for the implementation of low-frequency noise measurement systems
PublikacjaElectronic noise has its roots in the fundamental physical interactions between matter and charged particles, carrying information about the phenomena that occur at the microscopic level. Therefore, Low-Frequency Noise Measurements (LFNM) are a well-established technique for the characterization of electron devices and materials and, compared to other techniques, they offer the advantage of being non-destructive and of providing...
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Molecular Strategy for Survival at a Critical High Temperature in Eschierichia coli
PublikacjaThe molecular mechanism supporting survival at a critical high temperature (CHT) in Escherichia coli was investigated. Genome-wide screening with a single-gene knockout library provided a list of genes indispensable for growth at 47°C, called thermotolerant genes. Genes for which expression was affected by exposure to CHT were identified by DNA chip analysis. Unexpectedly, the former contents did not overlap with the latter except...
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Low harmonic multipulse voltage converters using coupled reactors
PublikacjaThis paper presents a novel approach to the multi pulse voltage converters (VC), especially voltage source inverters (VSI) and matrix converters (MC) based on several typical identical modules connected in parallel using coupled reactors. Such arrangements resulting in lower voltage distortions at extremely low switching frequency. The proposed arrangement was validated by simulation. Laboratory models of 18- and 24pulse 3-level...
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High Temperature Air/Steam Conversion of Biomass and Wastes Into Fuel Gas for Heat and Electricity Production
PublikacjaPaper present principle of high temperature air/staem gasification as well as some results of research using this technology for conversion of biomass and wastes into fuel gas.
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DETERMINING THE TIME CONSTANT USING TWO METHODS AND DEFINING THE THERMOCOUPLE RESPONSE TO SINE EXCITATION OF GAS TEMPERATURE
PublikacjaThis paper describes the two methods of determining the time constant of type K thermocouple, for two construction solutions: the exposed weld and the mantle fillet weld. This is an important parameter indicating the response time of the thermocouple on the recorded signal. The first method consists of determining the value of τ in the way of numerical simulation of heat exchange between the thermocouple and the current of gas...
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Impact of surface skin temperature change on blood flow characteristics in palm
PublikacjaHeating a human palm during 3 minutes period causes changes in superficial skin temperature and leads to thermoregulation system response. The response time and level of flow characteristics change depend on the subject hand size and health of his vascular tree. A solution of Pennes bioheat propagation model was analyzed in order to see how much heat has to be transferred into the tissue to extort the observable reaction. The reflective...
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On thermal stability of piezo-flexomagnetic microbeams considering different temperature distributions
PublikacjaBy relying on the Euler–Bernoulli beam model and energy variational formula, we indicate critical temperature causes in the buckling of piezo-flexomagnetic microscale beams. The corresponding size-dependent approach is underlying as a second strain gradient theory. Small deformations of elastic solids are assessed, and the mathematical discussion is linear. Regardless of the pyromagnetic effects, the thermal loading of the thermal...
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Long-term Hindcast Simulation of Currents, Sea Level, Water Temperature and Salinity in the Baltic Sea
PublikacjaThis dataset contains the results of numerical modelling of currents, sea level, water temperature and salinity over a period of 50 years (1958–2007) in the Baltic Sea. A long-term hindcast simulation was performed using a three-dimensional hydrodynamic model (PM3D) based on the Princeton Ocean Model (POM). The spatial resolution was 3 nautical miles, i.e. about 5.5 km. Currents, water temperature, and salinity were recorded...
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The analysis of temperature changes of the saliva traces left on the fur during laboratory rats social contacts
PublikacjaAutomatic analysis of complex rodent social be- havior, especially aggressive ones, is of important scientific interest. In this paper we analyze the properties of the data created as a result of aggressive rodent social behavior. Detec- tion of specific aggressive behaviors is based on the event of leaving traces of saliva on the fur of the attacked individual, which are clearly visible in the thermal imaging. The traces change...
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Simplified Numerical Model for Transient Flow of Slurries at Low Concentration
PublikacjaRapid transients are particularly dangerous in industrial hydro-transport systems, where solid-liquid mixtures are transported via long pressure pipelines. A mathematical description of such flow is difficult due to the complexity of phenomena and difficulties in determining parameters. The main aim of the study was to examine the influence of the simplified mixture density and wave celerity description on satisfactory reproduction...
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Investigation of the 0.4C-35Cr-45Ni-Nb Alloy after Service in High-Temperature Steam and Hydrocarbons Environment
PublikacjaThe paper presents the results of investigation of the 0.4C-35Cr-45Ni-Nb alloy, which operated in the cracked hydrocarbon feeds and dilution steam at 1125 C. The material originated from the pyrolytic furnace coil tubes, of which internal walls were in contact with the aforementioned medium, whereas the external walls were in contact with the flue gases. The examination included metallographic and mechanical tests on the material...
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Method of reconstructing two-dimensional velocity fields on the basis of temperature field values measured with a thermal imaging camera
PublikacjaThis paper describes a novel numerical reconstruction procedure (NRP) of the velocity field during natural convective heat transfer from a two-sided, isothermal, heated vertical plate based only on the known temperature field obtained, e.g. with a thermal imaging camera. It has been demonstrated that with a knowledge of temperature distributions, the NRP enables the reconstruction of velocity fields by solving the Navier-Stokes...
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Soft-decision schemes for radar estimation of elevation at low grazing angles
PublikacjaIn modern radars, the problem of estimating elevation angle at low grazing angles is typically solved using superresolution techniques. These techniques often require one to provide an estimate of the number of waveforms impinging the array, which one can accomplish using model selection techniques. In this paper, we investigate the performance of an alternative approach, based on the Bayesian-like model averaging. The Bayesian...
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Accurate Lightweight Calibration Methods for Mobile Low-Cost Particulate Matter Sensors
PublikacjaMonitoring air pollution is a critical step towards improving public health, particularly when it comes to identifying the primary air pollutants that can have an impact on human health. Among these pollutants, particulate matter (PM) with a diameter of up to 2.5 μ m (or PM2.5) is of particular concern, making it important to continuously and accurately monitor pollution related to PM. The emergence of mobile low-cost PM sensors...
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Polyurethane glycolysate from industrial waste recycling to develop low dielectric constant, thermally stable materials suitable for the electronics
PublikacjaWe are utilizing a new method to improve the dielectric properties of a conventional polymer using a recycled polymer product. The polyurethane foams are recycled by glycolysis process and the derived material was applied to improve the dielectric properties of the brittle DGEBA epoxy resin. Two main parameters that determine the applicability of the material as a dielectric (the dielectric constant and dielectric loss), were studied...
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Comparative electrochemical analysis of the passive layer cracking process on aluminum alloys performed by means of DC and AC techniques
PublikacjaZbadano proces pękania warstwy pasywnej na stopach aluminium AA1050, AA5052, AA5056, oraz AA7005 w warunkach zmiennych naprężeń rozciągających i polaryzacji anodowej z wykorzystaniem techniki stałoprądowej, DEIS oraz emisji akustycznej (AE), jako metody porównawczej. Przeprowadzone badania pokazały przewagę techniki DEIS oraz emisji akustycznej nad klasyczną techniką stałoprądową. Wyznaczono dokładny moment pęknięcia warstwy pasywnej...
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Stress corrosion cracking of Al-Zn-Mg weldments.Korozja naprężeniowa złączy spawanych stopów Al-Zn-Mg.
PublikacjaPraca zawiera wyniki badań odporności korozyjnej złączy spawanych Al-Zn-Mg. Zbadano wpływ składu chemicznego stopu oraz spoiwa na odporność na korozje naprężeniową w warunkach statycznych naprężeń rozciągających.
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Influence of retrogression and reaging on microstructure, mechanical properties and susceptibility to stress corrosion cracking of an Al-Zn-Mg alloy.
PublikacjaPrzedmiotem badań był stop AlZn5Mg1 poddany nawrotowi i starzeniu w różnej temperaturze i przez różny czas. Badano podatność na korozję naprężeniową przy stałej prędkości rozciągania 10-6 s-1. Obróbka cieplna, która polepsała własności, pogarszała odporność na korozję naprężeniową. Efekty te przypisano zmianiom wielkości i rozkładu wydzieleń.
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Korozja naprężeniowa stali 14hnmbcu w środowisku wody morskiej.Stress corrosion cracking of 14hnmbcu steel in sea-water.
PublikacjaW pracy przedstawiono zagadnienia niszczenia środowiskowego stali o wysokiej wytrzymałości na konstrukcje morskie. Podatność stali 14HNMBCu i jej złącza spawanego na naprężeniowe pękanie korozyjne badano w oparciu o próbę powolnego rozciągania. Próby wykonano w środowisku powietrza oraz wody morskiej przy polaryzacji katodowej.
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Electrochemical analysis of the passive layer cracking process on A95052 aluminium alloy performed by means of DC and AC techniques
PublikacjaPraca dotyczy porównania zastosowania technik stało- i zmiennoprądowych do badania pękania warstwy pasywnej na różnych stopach aluminum podczas testów rozciągania mechanicznego w warunkach polaryzacji anodowej.
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Multimodal analysis of traction forces and the temperature dynamics of living cells with a diamond-embedded substrate
PublikacjaCells and tissues are constantly exposed to chemical and physical signals that regulate physiological and pathological processes. This study explores the integration of two biophysical methods: traction force microscopy (TFM) and optically detected magnetic resonance (ODMR) to concurrently assess cellular traction forces and the local relative temperature. We present a novel elastic substrate with embedded nitrogen-vacancy microdiamonds...
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Low-Cost EM-Simulation-Driven Multi-Objective Optimization of Antennas
PublikacjaA surrogate-based method for efficient multi-objective antenna optimization is presented. Our technique exploits response surface approximation (RSA) model constructed from sampled low-fidelity antenna model (here, obtained through coarse-discretization EM simulation). The RSA model enables fast determination of the best available trade-offs between conflicting design goals. A low-cost RSA model construction is possible through...
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Low-energy positron scattering from gas-phase uracil
PublikacjaQuantum scattering calculations are presented for the interaction of low energy positrons with the uracil molecule, an important component of biological systems. The rotational elastic and inelastic cross sections and vibrational inelastic cross sections are reported and compared with existing experiments, indicating a general trend of the cross sections different from the experimental findings and in line with what should be expected...
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Impact of high temperature drying process on beech wood containing tension wood
PublikacjaThe technology of high temperature drying has a great inuence on dimensional and selected physical changes in tension wood. Article is focused on the measurement properties such as moisture content, color changes and longitudinal warping. The quality of beech wood is determined based on structure and properties of wood, frequency of defects in wood material. The tension wood is considered as an important wood defect causing negative...
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Distribution of Temperature in Multicomponent Multilayered Composites
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Temperature-dependent photoluminescence of polyazomethine films
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Optimal boiling temperature for ORC installation
PublikacjaW pracy przedstawiono oryinalne kryterium wyznaczania optymalnej temperatury odparowania czynnika w obiegu ORC w postaci równań analitycznych. Pokazano przykład obliczeniowy na bazie R134a, wody i etanolu.
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Low-Power WSN System for Honey Bee Monitoring
PublikacjaThe paper presents a universal low-power system for biosensory data acquisition in scope of bees monitoring. We describe the architecture of the system, energy-saving components as well as we discuss the selection of used sensors. The work focuses on energy optimization in a scope of wireless communication. A custom protocol was implemented, which is the basis for presented energy-efficient devices. Data exchange process during...
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The effect of high pressure and subzero temperature on gelation of washed cod and salmon meat
PublikacjaThe objective of the present work is to examine the infl uence of pressure up to 193 MPa at subzero temperature (without freezing of water) on myofi brillar proteins of salmon and cod meat and on the properties of gels obtained from washed mince of these fi sh. The solubility of proteins from myofi brils of cod and salmon meat suspended in 100 mM KCl solution increased aft er treating the samples with pressure above 60 MPa. The...
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Exchange of radiation in high temperature air combustion furnaces by application of the transfer configuration factors
PublikacjaW artykule przedstawiono metodę obliczeń pasmowej radiacyjnej wymiany ciepła w układzie otwartym z gazem iztermicznym za pomocą uogólnionych współczynników konfiguracji. Metoda może być użyta do obliczeń wymiany ciepła w piecach z technologią High Temperature Air Combustion gdzie występuje prawie jednorodna temperatura. Podano przykład obliczeniowy.
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Determination of Thermophysical Parameters Involved in The Numerical Model to Predict the Temperature Field of Cast-In-Place Concrete Bridge Deck
PublikacjaThe paper dealswith a concept of a practical computationmethod to simulate the temperature distribution in an extradosed bridge deck. The main goal of the study is to develop a feasible model of hardening of concrete consistent with in-situ measurement capabilities. The presented investigations include laboratory tests of high performance concrete, measurements of temperature evolution in the bridge deck and above all, numerical...