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Wyniki wyszukiwania dla: thermal analysis
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Performance properties of rigid polyurethane-polyisocyanurate/brewers’ spent grain foamed composites as function of isocyanate index
PublikacjaIn the presented work, rigid polyurethane-polyisocyanurate (PUR-PIR) foams filled with brewers’ spent grain (BSG) were prepared. The influence of the isocyanate index (II) on its performance was investigated. Foams obtained with higher isocyanate index required a higher amount of hydrofluorocarbon physical blowing agent to provide the same apparent density of material. An increase of isocyanate index resulted in a slight decrease...
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Multi-region fuzzy logic controller with local PID controllers for U-tube steam generator in nuclear power plant
PublikacjaIn the paper, analysis of multi-region fuzzy logic controller with local PID controllers for steam generator of pressurized water reactor (PWR) working in wide range of thermal power changes is presented. The U-tube steam generator has a nonlinear dynamics depending on thermal power transferred from coolant of the primary loop of the PWR plant. Control of water level in the steam generator conducted by a traditional PID controller...
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Experimental Investigations on the Influence of Coil Arrangement on Melting/Solidification Processes
PublikacjaThe latent heat thermal energy storage units are very popular because of their high energy density and almost close to constant temperature during the charging/discharging. In the present study has been proposed new shell-and-coil geometry with a shifted coil position to enhance the performance of phase change thermal magazine. The experimental investigations have been performed both for the melting and solidification process of...
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Photoresponsive Amide-Based Derivatives of Azobenzene-4,4′-Dicarboxylic Acid—Experimental and Theoretical Studies
PublikacjaAzobenzene derivatives are one of the most important molecular switches for biological and material science applications. Although these systems represent a well-known group of compounds, there remains a need to identify the factors influencing their photochemical properties in order to design azobenzene-based technologies in a rational way. In this contribution, we describe the synthesis and characterization of two novel amides...
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Preparation and characterization of bis‐phosphonated polycarbohydrates
PublikacjaA simple, cost-effective, one-pot method was proposed to introduce bis-phosphonic groups onto alginic acid and carboxymethyl cellulose (CMC). New derivatives were characterized by means of nuclear magnetic resonance, X-ray photoelectron, and attenuated total reflectance Fourier transform infrared spectroscopy. These analyses confirmed the successful transformation of carboxylic groups present in alginic acid and CMC into bis-phosphonic...
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Gas boiler as a heat source for the domestic micro-CHP
PublikacjaThis analysis considers a commercially available domestic gas boiler as a heat source for a domestic organic Rankine cycle system. An experimental study was made into the applicability of the gas boiler (De Dietrich with thermal power 25 kW) coupled with the laboratory prototype micro ORC setup. The main aim of the study is to determine the working fluid temperature, attainable heat rates and effciencies of the whole system. Preliminary...
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Gas boiler as a heat source for the domestic micro-CHP
PublikacjaIn the presented analysis a commercially available domestic gas boiler as a heat source for domestic ORC is considered. The applicability of the gas boiler (De Dietrich with thermal power 25 kW) coupled with the laboratory prototype micro ORC setup has experimentally studied. The main aim of the study is to determine the working fluid temperature, attainable heat rates and efficiencies of the whole system. Preliminary investigations...
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Kinetics of cross-linking processes of fast-curing polyurethane system
PublikacjaThis work focuses on the application of thermal analysis and kinetics investigations to analyze chemical processes during cross-linking of the complex fast-curing polyurethane system. Non-isothermal Differential Scanning Calorimetry (DSC) measurements were performed for both stoichiometric mixtures of polyol and isocyanate component and for mixture with large isocyanate excess. Isoconversional methods were used to calculate initial...
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Valorization of Bioplastic Waste: A Review on Effective Recycling Routes for the Most Widely Used Biopolymers
PublikacjaPlastics-based materials have a high carbon footprint, and their disposal is a considerable problem for the environment. Biodegradable bioplastics represent an alternative on which most countries have focused their attention to replace of conventional plastics in various sectors, among which food packaging is the most significant one. The evaluation of the optimal end-of-life process for bioplastic waste is of great importance...
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Cattaneo–Christov heat flow model for copper–water nanofluid heat transfer under Marangoni convection and slip conditions
PublikacjaThis report is devoted to the study of the flow of MHD nanofluids through a vertical porous plate with a temperature-dependent surface tension using the Cattaneo–Christov heat flow model. The energy equation was formulated using the Cattaneo–Christov heat flux model instead of Fourier’s law of heat conduction. The Tiwari–Das model was used to take into account the concentration of nanoparticles when constructing the momentum equation....
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AN ORIGINAL APPROACH IN THE FIELD OF PREPARATION REFERENCE MATERIALS OF VOLATILE ANALYTES
PublikacjaStandard gas mixtures (SGM) are indispensable reference materials for ensuring the reliability of analytical work. Reference materials are an excellent tool for the quality control and assurance of analytical results. Standard gas mixtures are unique among reference materials. The rapid progress of SGM production is connected with the instability of gaseous analytes which make them difficult to obtain. The use of standards with...
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Hyperbolic heat conduction at a microscopic sliding contact with account of adhesion-deformational heat generation and wear
PublikacjaDifferent non-Fourier models were proposed to simulate temperatures in materials subjected to extremely fast thermal disturbances, when the speed of heat propagation should be concerned. The present study investigated temperature and heat balance at a microscopic sliding contact during a single frictional interaction based on the Cattaneo-Vernotte hyperbolic heat conduction equation. Two fundamental features of friction, namely,...
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Giant Reed (Arundo donax L.) Fiber Extraction and Characterization for Its Use in Polymer Composites
PublikacjaThis work describes an extraction method for giant reed fibers from stems and leaves based on chemical soaking and crushing through a rolling mill. Obtained fibers, together with the shredded plant (stems + leaves), are characterized in terms of chemical composition, thermal stability, morphology, and crystallinity. Mechanical properties of fibers have also been assessed (single fiber tensile tests). The results show that the proposed...
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Effect of Coating Material Properties on Tilting-pad Thrust Bearing Performance
PublikacjaPolymer lined tilting-pad bearings demonstrate many advantages over traditional bearing systems. Bearings with a polymer layer in comparison with a babbitted layer show, for example: lower value of friction coefficient (important during start/stops), higher fatigue strength of the coating, better distribution of the load on individual pads due to lower elasticity of the polymers, wider range of operational temperatures or the ability...
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Determination of the thermal conductivity of material dividing the metallic core elements of the bi-calorimeter using modified theory
PublikacjaW pracy przedstawiono zmodyfikowaną teorię bikalorymetru z dzielonym metalowym rdzeniem. Pomiędzy dwiema częściami rdzenia umieszczano próbki badanego ciała stałego lub gazu. Ogrzewano jedną stronę rdzenia. Mierzono temperaturę obu części rdzenia w funkcji czasu. Uzyskane wyniki umożliwiły wyznaczenie różnicy temperatur i strumienia ciepła, przepływającego przez próbkę. Z zastosowaniem prawa Fouriera obliczano współczynnik przewodności...
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Simultaneously improving the thermal stability, flame retardancy and mechanical properties of polyethylene by the combination of graphene with carbon black
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Comprehensive studies on the properties of apple juice treated by non-thermal atmospheric plasma in a flow-through system
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Effect of Thermal Treatment at Inert Atmosphere on Structural and Magnetic Properties of Non-stoichiometric Zinc Ferrite Nanoparticles
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Thermal quenching of Ce3+luminescence in the cuspidine-type oxide nitride compounds Y4Si2−xAlxO7+xN2−x
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Ice Regime of the Kozłowa Góra Reservoir (Southern Poland) as an Indicator of Changes of the Thermal Conditions of Ambient Air
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Laser Thermal Oxidation by Ytterbium-Doped Fibre Laser of the Hot and Cold-Rolled Stainless Steel Surface
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Thermal Barrier Stability and Wear Behavior of CVD Deposited Aluminide Coatings for MAR 247 Nickel Superalloy
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Numerical Verification of Tests on the Influence of the Imposed Thermal Cycles on the Structure and Properties of the S700MC Heat-Affected Zone
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Thermal Design of Double Pipe Heat Exchanger Used as an Oil Cooler in Ships: A Comparative Case Study
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Superconductivity in PrBa 2Cu 3O 7− δ single crystals after high-temperature thermal treatment
PublikacjaThe influence of post-growth treatment, consisting of high-temperature reduction, quench and oxidation, on the structural, electrical and magnetic properties of PrBa2Cu3O7−δ single crystals, obtained in Al2O3 and ZrO2 crucibles by the self-flux method, was examined. We report on the observation of inhomogeneous superconductivity in several Al-doped crystals from the ac magnetic susceptibility and resistivity measurements. Superconducting...
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Thermal, structural and spectroscopic properties of heavy metal oxide glass and glass-ceramics doped with Er3+ions
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Utilization of thermal decomposition of immobilized compounds for the generation of gaseous standard mixtures used in the calibration of gas analysers
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Study of a method for the preparation of standard gas mixtures based on thermal decomposition of surface compounds. Application to isothiocyanates
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Influence of different types of the internal system of the ballistic helmet shell on the thermal insulation measured by a manikin headform
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AN IMPACT OF THE EFFICIENT FUNCTIONING OF THE VENTILATION AND AIR-CONDITIONING SYSTEM ON THERMAL COMFORT OF THE MEDICAL STAFF IN THE OPERATING ROOM
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Thermal and mechanical properties of (W,Zr)B2-z coatings deposited by RF magnetron sputtering method
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The effect of CeO2 on the thermal stability, structure and thermoluminescence and optically stimulated luminescence properties of barium borate glass
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Sulfonated poly(benzoyl paraphenylene) as a membrane for PEMFC: Ex situ and in situ experiments of thermal and chemical stability
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Comparison of How Graphite and Shungite Affect Thermal, Mechanical, and Dielectric Properties of Dielectric Elastomer-Based Composites
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Synthesis and Thermal, Photophysical, Electrochemical Properties of 3,3-di[3-Arylcarbazol-9-ylmethyl]oxetane Derivatives
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Possibility of thermal imaging use in studies of natural convection heat transfer on the example of an isothermal vertical plate
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Investigating the Effect of Aluminum Diethylphosphinate on Thermal Stability, Flame Retardancy, and Mechanical Properties of Poly(butylene succinate)
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DOPO-Functionalized Molybdenum Disulfide and its Impact on the Thermal Properties of Polyethylene and Poly(Lactic Acid) Composites
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Tribological and thermal behavior with wear identification in contact interaction of the Ti6Al4V-sintered carbide with AlTiN coatings pair
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Operation of a ground thermal energy storage supplied by different sources in a low-temperature district heating network
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Practice in the Field of Thermal Retrofitting in Historic Buildings and Preservation of the Authentic Tissue of Façades of Historic Buildings in Poland
PublikacjaThe pursuit to reduce emissions of harmful substances to the atmosphere resulting from the combustion of fuels for heating purposes makes a building more ecological and environmentally friendly. All operations aimed to limit emissions of pollutants into the atmosphere are motivated by the growing environmental awareness of developed societies and alarming reports on the global warming and its effects. In Poland, legal regulations...
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Experimental investigation of PCM thermal energy storage charge and discharge process with aperiodic (ramp) temperature inputs
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Cooling System with PCM Storage for an Office Building: Experimental Investigation Aided by a Model of the Office Thermal Dynamics
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Examining the Influence of Re–Used Nanofiller—Pyrolyzed Montmorillonite, on the Thermal Properties of Polypropylene–Based Engineering Nanocomposites
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High level synthesis with adaptive evolutionary algorithm for solving reliability and thermal problems in reconfigurable microelectronic systems.
PublikacjaPraca dotyczy badań efektywności adaptacyjnego algorytmu ewolucyjnego (AEA)zastosowanego do syntezy wysokiego poziomu układów cyfrowych CMOS w celu zredukowania rozpraszanej przez nie mocy. W wyniku obniżenia poziomu mocy pobieranej przez układ mikroelektroniczny uzyskuje się zmniejszenie szczytowej i średniej temperatury układu scalonego co z kolei prowadzi do wzrostu niezawodności całego systemu. Podczas przeprowadzonych...
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Possibility of thermal imaging use in studies of natural convection heat transfer on the example of an isothermal vertical plate.
PublikacjaA new method of infrared (IR) camera use in convective heat transfer studies has been presented. Until now, IR cameras were utilized for temperature field visualizations of flat heated surfaces of solid objects only. Because liquids and gasses do not emit radiation in the infrared range of wave lengths, detection of temperature field in the air was conducted with the use of plastic mesh, which, after heating by hot air, emits infrared...
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Thermal and Electrodynamic Risk of Residual Current Devices in the Case of Back-Up Protection by Overcurrent Circuit Breakers
PublikacjaResidual current operated circuit breakers without integral overcurrent protection should be back-up protected. As back-up protection devices, overcurrent circuit breakers are used. The maximum let-through energy and let-through current of the overcurrent devices were evaluated under laboratory conditions. The thermal and electrodynamic risk of residual current devices was analyzed.
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The effect of nitrogen on the structure and thermal properties of beryllium-containing Na-(Li)-Si-O-N glasses
PublikacjaTwo oxynitride glass series with the composition of 35Na2O-5BeO-(60-x)SiO2-xSi3N4 and 9Li2O- 27Na2O-5BeO-(59-x)SiO2-xSi3N4, were prepared. The glasses' topography and structure were studied by Scanning Electron Microscopy and Raman spectroscopy. The composition was analyzed by Inductively Coupled Plasma Optical Emission Spectrometer, SEM-EDS and nitrogen and oxygen elemental analyzer. Na-(Li)-Be-silicate glasses were found to contain...
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Improving Thermal Insulation Properties for Prefabricated Wall Components Made of Lightweight Aggregate Concrete with Open Structure
PublikacjaPorous concrete is commonly used in civil engineering due to its good thermal insulation properties in comparison with normal concrete and high compression strength in comparison with other building materials. An extremely porous concrete, called ‘lightweight aggregate concrete with open structure’ (LAC), is used in some German plants to produce prefabricated wall components. They are used mainly in hall buildings, e.g. supermarkets....
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Effect of osmolytes on the thermal stability of proteins: replica exchange simulations of Trp-cage in urea and betaine solutions
PublikacjaAlthough osmolytes are known to modulate the folding equilibrium, the molecular mechanism of their effect on thermal denaturation of proteins is still poorly understood. Here, we simulated the thermal denaturation of a small model protein (Trp-cage) in the presence of denaturing (urea) and stabilizing (betaine) osmolytes, using the all-atom replica exchange molecular dynamics simulations. We found that urea destabilizes Trp-cage...