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Search results for: LOW TEMPERATURE PROPERTIES
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High-temperature heat pumps – new devices for heat recovery and production of technological steam
PublicationIn the paper, the original high temperature compressor based heat pump with a dry working fluid, i.e. the one in which the slope of saturated vapour line is positive, was presented. The objective of the paper is to investigate the possibility of preparation of technological steam with tempperature 120 C from the waste heat resource at temperature of 50 C. Single comppression cycles as well as cascade systems have been considered...
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Eco-friendly Route for Thermoplastic Polyurethane Elastomers with Bio-based Hard Segments Composed of Bio-glycol and Mixtures of Aromatic–Aliphatic and Aliphatic–Aliphatic Diisocyanate
PublicationApplication of bio-based diisocyanates with low volatility instead petrochemical diisocyanates has positive impact on environment by reduction of hazardous effects on living organisms and lead to bio-based polyurethanes (bio-PUs) with good usage properties. This work was focused on the synthesis and chosen properties examination of partially bio-based thermoplastic polyurethane elastomers (bio-PUs) obtained using diisocyanate mixtures,...
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Influence of PWHT Parameters on the Mechanical Properties and Microstructural Behavior of Multi-Pass GTAW Joints of P92 Steel
PublicationThe 9% Cr steels were developed for ultra-supercritical (USC) power plants to meet the requirements of high operating temperature and pressure. These steels are produced to operate at high temperatures where impact toughness is not a concern; however, it becomes important for the welded joints to have good impact toughness at room temperature for manufacturing. The present work investigates the effect of the post-weld heat treatment...
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Hard carbon derived from rice husk as low cost negative electrodes in Na-ion batteries
PublicationHere, we report the synthesis of hard carbon materials (RH) made from natural rice husk through a single pyrolysis process and their application as an anode in sodium-ion batteries. The studies show that the electrochemical properties of RHs are affected by the treatment temperatures, which determine the materials morphology, in particular, their degree of graphitization and extent of continuous channels (nanovoids). The latter...
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Analytical method for calculation of heat source temperature drop for the Organic Rankine Cycle application
PublicationIn the paper presented are considerations on the cooperation of the limited capacity heat source with the Organic Rankine Cycle unit. Usually the heat source providing thermal energy to the Organic Rankine Cycle (ORC) may have twofold characteristics. It can be in the form of a single phase fluid, i.e. as hot exhaust gas or hot liquid, or in some cases it may be available as a phase changing fluid, as for example, technological...
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Fabrication, Microstructure and High Temperature Corrosion Resistance of Porous Alloys for Solid Oxide Fuel Cells
PublicationPorous alloys find use in modern Solid Oxide Fuel Cells as the supporting structures. As they are exposed to high temperatures (> 500°C) an oxide scale forms on their surface due to high temperature corrosion phenomena. Since the ratio between the surface area and volume is much higher than for planar samples, formation of the oxide can lead to a breakaway oxidation after relatively short times. Therefore corrosion properties of...
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Multimodal analysis of traction forces and the temperature dynamics of living cells with a diamond-embedded substrate
PublicationCells 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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Exchange of radiation in high temperature air combustion furnaces by application of the transfer configuration factors
PublicationW 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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DETERMINING THE TIME CONSTANT USING TWO METHODS AND DEFINING THE THERMOCOUPLE RESPONSE TO SINE EXCITATION OF GAS TEMPERATURE
PublicationThis 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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Mechanism of Reduced Sintering Temperature of Al2O3–ZrO2 Nanocomposites Obtained by Microwave Hydrothermal Synthesis
PublicationA novel method to obtain Al2O3–ZrO2 nanocomposites is presented. It consists of the co-precipitation step of boehmite (AlO(OH)) and ZrO2, followed by microwave hydrothermal treatment at 270 ◦ C and 60 MPa, and by calcination at 600 ◦ C. Using this method, we obtained two nanocomposites: Al2O3–20 wt % ZrO2 and Al2O3–40 wt % ZrO2. Nanocomposites were characterized by Fourier transformed infrared spectroscopy, Raman spectroscopy,...
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High temperature monoclinic-to-tetragonal phase transition in magnesium doped lanthanum ortho-niobate
PublicationMagnesium doped lanthanum ortho-niobate (La0.98Mg0.02NbO4) was prepared by the molten salt synthesis method. X-ray diffraction and dilatometry methods were used to study high temperature behavior of the ceramic material. Special attention was paid to the phase transition between the monoclinic and tetragonal phases. The values of spontaneous strain on the basis of unit cell parameter, obtained by Rietveld refinement, have been...
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Diagnostic tolerances' evaluation method of the start-up exhaust temperature of a naval gas turbine
PublicationThe conducted investigations aimed to elaborate the method of marking diagnostic tolerances of the exhaust temperature of a gas turbine observed during engine's start-up process. The diagnostic tolerances were determined by means of statistical inference by creating the hypothesis about a normal distribution of the start-up exhaust temperature's dispersion in the initial operation moment, which was subsequently verified applying...
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The hydration of selected biologically relevant molecules – the temperature effect on apparent molar volume and compression
PublicationThe densities and sound velocities at T = (288.15, 293.15, 298.15, 303.15 and 308.15) K were measured for aqueous solutions of glycine, trimethylamine-N-oxide, taurine and N-methylacetamide. From these data, the apparent molar volumes, V the apparent molar isentropic compressions, KS,, and the Passynski hydration numbers of solutes were determined. The concentration dependencies of the calculated quantities, their limiting values...
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Measurement of temperature-dependent viscosity and thermal conductivity of alumina and titania thermal oil nanofluids
PublicationThe results of simultaneous measurements of dynamic viscosity, thermal conductivity, electrical conductivity and pH of two nanofluids, i.e. thermal oil/Al2O3 and thermal oil/TiO2 are presented. Thermal oil was selected as a base liquid because of possible application in ORC systems as an intermediate heating agent. Nanoparticles were tested at the concentration of 0.1%, 1% and 5% by weight within temperature range from 20°C to...
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MEASUREMENT OF TEMPERATURE-DEPENDENT VISCOSITY AND THERMAL CONDUCTIVITY OF ALUMINA AND TITANIA THERMAL OIL NANOFLUIDS
PublicationIn this study results of simultaneous measurements of dynamic viscosity, thermal conductivity, electrical conductivity and pH of two nanofluids, i.e. thermal oil/Al2O3 and thermal oil/TiO2 are presented. Thermal oil is selected as a base liquid because of possible application in ORC systems as an intermediate heating agent. Nanoparticles were tested at the concentration of 0.1%, 1% and 5% by weight within temperature range from...
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Crack propoagation in MgO-PSZ ceramic materials
PublicationThe properties of ceramic materials such as elevated hardness, high temperature capability, low coefficient of thermal expansion are of interest for rolling element materials. Widely used ceramic materials in engineering applications are silicon nitride, zirconia and alumina. The paper presents an experimental study of the fatigue life of MgO-PSZ ceramic material in lubricated contact with defined types of cracks. A ceramic angular...
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Charge density wave, enhanced mobility, and large nonsaturating magnetoresistance across the magnetic states of HoNiC2 and ErNiC2
PublicationWe report on magnetotransport and thermoelectric properties of two ternary carbides HoNiC2 and ErNiC2 hosting both charge density wave and long-range magnetic order. In the charge density wave state, both compounds show relatively large magnetoresistance MR ≈ 150% in HoNiC2 and ≈ 70%in ErNiC2 at a magnetic field of 9 T and temperature as low as 2 K. This positive field-linear magnetoresistance shows no signatures of saturation....
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Assessing Acute Toxicity of Selected Packages Internal Layers Extracts using Microtox®
PublicationIn the scientific literature related to the widely understood issue of packaging materials designed to have contact with food (food contact materials), there is much information on raw materials used for their production, as well as their physiochemical properties, types and parameters. Unfortunately, not much attention is given to the issues concerning migration of toxic substances from packaging and its actual influence on the...
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Influence of high temperature air-steam mixture application on time wood drying process
PublicationThe results of influence gas-steam mixture drying process on time wood drying process are presented. Wood species, namely oak (Quercus L.), beech (Fagus L.), pine (Pinus L.) and spruce (Picea K.) from the northern part of Pomerania region in Poland, were subject of air-steam mixture drying process. Main focus of those tests was to shorten the time of drying process and afterward to check properties of wood.
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Room temperature depinning of the charge-density waves in quasi-two-dimensional 1T-TaS2 devices
PublicationWe report on the depinning of nearly commensurate charge-density waves in 1T-TaS2 thin films at room temperature. A combination of the differential current–voltage measurements with the low-frequency noise spectroscopy provides unambiguous means for detecting the depinning threshold field in quasi-2D materials. The depinning process in 1T-TaS2 is not accompanied by an observable abrupt increase in electric current—in striking contrast...
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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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Effect of temperature and gaseous medium on the structure and microhardness of the cobalt base clad layers
PublicationBadano wpływ temperatury utleniania na mikrostrukturę i mikrotwardość napawanych warstw ze stopu kobaltu. Warstwy wytwarzano za pomocą napawania plazmowego (pta) na przylgniach zaworów wylotowych wykonanych ze stali x40CrSiMo10-2. Stop kobaltu był poddany utlenianiu w powietrzu w temperaturach od 750 °C to 1100 °C i w gazach wylotowych w temperaturze 750 °C. W wyniku utleniania zaobserwowano zmanę w mikrotwardości warstw. W zewnętrznej...
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The influence of the substrate temperature on the preparation of DNA films for studies under vacuum conditions
PublicationPrzeanalizowano wpływ temperatury na formowanie warstw DNA. Sprawdzono wpływ stabilizatorów na jakość otrzymanych próbek. Stwierdzono, że optymalnymi warunkami przygotowywania filmów do badań w warunkach próżniowych jest - 10 st. C przy minimalnej zawartości NaOH.
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Effect of pH and high pressure at sub-zero temperature on the viability of some bacteria
PublicationCelem badań było określenie przeżywalności Escherichia coli i Staphylococcus aureus zawieszonych w soku jabłkowym (pH 3,8) po działaniu ciśnienia 193MPa w temperaturze -20°C. Stwierdzono, że bezpośrednio po działaniu ciśnienia przeżywalność badanych szczepów bakterii nie zmieniała się znacząco. Jednakże liczba komórek zmniejszała się z czasem przechowywania ciśnieniowanych prób. Żywe komórki mikroorganizmów nie były wykrywane w...
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Effect of extracting time and temperature on yeild of gelatin from different fish offal
PublicationCelem pracy było określenie optymalnych warunków otrzymywania żelatyny z różnych rodzajów odpadów powstających podczas obróki wstępnej lub przetwarzania surowców rybnych. Wydajność ekstrakcji żelatyny w 45°C z surowych skór łososia i kręgosłupów wynosiła 71-75% oraz 86% ze skór łososia wędzonego. W przypadku skór z marynowanego i solonego śledzia przemianie do żelatyny ulegało w tych warunkach około 100% kolagenu. Optymalny czas...
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Chapter 1. Modelling of temperature field of cylindrical pool boiling heating section
PublicationPoddano analizie fundamentalny problem określania temperatury powierzchni, na której zachodzi wrzenie. Rozpatrzono dwa przypadki ogrzewania sekcji: z zastosowaniem grzejnika patronowego oraz użyciem sekcji jako elementu oporowego. Sformułowano i rozwiązano zagadnienia brzegowe 1D, 2D ORAZ 3D. Przedstawiono wyniki obliczeń numerycznych z zastosowaniem MES.
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High temperature oxidation of porous alloys for solid oxide fuel cell applications
PublicationW pracy proszki PI600, 317L i 430L stali użyto do przygotowania porowatych metalowych podłoży dla tlenkowych ogniw paliwowych. Po spiekaniu w różnych temperaturach oceniana była ich porowatość i wysokotemperaturową odporność na korozję. Cykliczna analiza termograwimetryczna, dyfraktometria rentgenowska i obrazów SEM były używane do opisu właściwości tych porowatych stopów. Właściwości elektryczne badano dla wybranych próbek. Wpływ...
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Spatial and interannual variations of seasonal sea surface temperature patterns in the Baltic Sea
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Modelling of temperature field of flat boiling section with active single nucleation site
PublicationZaprezentowano główne założenia wybranych modeli wrzenia dla pojedynczego centrum nukleacji. Przedstawiony model numeryczny dotyczy zagadnienia dwuwymiarowego, osiowo-symetrycznego, nieizotropowego przewodzenia ciepła dla warunków brzegowych pierwszego, drugiego i trzeciego rodzaju. Warunek brzegowy drugiego rodzaju reprezentuje gęstość strumienia ciepła połączoną z generacją pęcherzy z pojedynczego centrum nukleacji.
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Comparison of commercial thermoluminescent readers regarding high-dose high-temperature measurements
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TEMPERATURE AND RELATIVE HUMIDITY CONTROL IN MASS AND DECAY PREVENTION IN POSTHARVEST HANDLING OF PEACHES
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Cointegration approach for temperature effect compensation in Lamb-wave-based damage detection
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The effect of nanomaterials on thermal resistance of cement-based composites exposed to elevated temperature
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Long-term air temperature variation in the Karkonosze mountains according to atmospheric circulation
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Room‐Temperature Multiferroicity and Magnetization Dynamics in Fe/BTO/LSMO Tunnel Junction
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Luminescence quenching in KYb(WO4)2-Tb3+: An example of temperature-pressure equivalence
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Temperature effect on the emission spectra of narrow band Mn4+phosphors for application in LEDs
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P3HT:PCBM blend films phase diagram on the base of variable-temperature spectroscopic ellipsometry
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Phase diagram of P3HT:PC70BM thin films based on variable-temperature spectroscopic ellipsometry
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Processing of polymer‐derived, aerogel‐filled, SiC foams for high‐temperature insulation
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<title>Modeling of noncontact temperature measurement system using multiwavelength pyrometry</title>
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Optimization of white light interferometric temperature sensor. Workshop on Atomic and Molecular Physics.
PublicationW artykule przedstawiono metodę optymalizacji parametrów niskokoherencyjnego interferometrycznego czujnika temperatury wykorzystującego miniaturowy interferometr Farby Perota, pracujący w modzie odbiciowym.
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The effect of temperature during soybean oil hydrogenation on nickel catalyst poisoning by phospholipids.
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In plane and out of plane temperature dependencies of the resistivity insingle crystals and films of Nd2CuO4.
PublicationW pracy przedstawiono temperaturową zależność oporu elektrycznego kryształów i cienkich warstw związku Nd2CuO4. Dyskutowany jest wpływ temperatury i atmosfery dodatkowej obróbki termicznej na własności transportowe.
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The measurement and calculation of gas temperature inside a switchgear during fault arc period.
PublicationW artykule przedstawiono metodę obliczania temperatury gazu wewnątrz rozdzielnicy szczelnej z izolacją powietrzną podczas zwarć łukowych w oparciu o równanie przewodnictwa cieplnego. Przedstawiono wyniki badań eksperymentalnych temperatury gazów podczas zwarć z łukiem wędrującym. Opisano model do badań, układ probierczy i warunki badań. Wyniki obliczeń porównano z wynikami badań eksperymentalnych.
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Effect of high pressure and sub-zero temperature on some gram-negative bacteria.
PublicationCelem pracy było określenie przeżywalności wybranych gramujemnych bakterii na działanie wysokiego ciśnienia i ujemnej temperatury. Traktowanie komórek bakterii ciśnieniem 193 MPa w temperaturze -20C przez 24 godziny, powodowało całkowitą inaktywację bakterii E. coli, P. fluorescens i T. thermophilus. Po działaniu ciśnienia przez krótszy czas występowały różnice we wrażliwości między badanymi szczepami. Najmniej odporny na działanie...
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Temperature effect on the current-voltage characteristic fill factor for the silicon solar cells
PublicationW pracy przedstawiono badania wpływu temperatury pracy krzemowych ogniw fotowoltaicznych na wartość współczynnika wypełnienia charakterystyki prądowo- napięciowej (FF). Efekty dyfuzyjne w obszarze złącza oraz rekombinacja nośników ładunku ograniczają wartość współczynnika wypełnienia charakterystyki. Spadek tej wartości wynika głównie ze wzrostu wartości rezystancji szeregowej rs. Na rezystancję szeregową składają się: opór emitera...
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Comparison of different advanced oxidation processes for the degradation of room temperature ionic liquids
PublicationZbadano możliwość zastosowania wybranych zaawansowanych technologii utleniania (UV, UV/H2O2, UV/TiO2) do degradacji cieczy jonowych. Do degradacji wytypowano pięć związków: HHiM, BMiM, MiM, OMiM oraz EEiM.
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Novel temperature operated electrooptical materials based on K2ZnCl4: PVA polymer nanocomposites
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Pre-oxidation of porous ferritic Fe22Cr alloys for lifespan extension at high-temperature
PublicationPre-oxidation of porous ferritic Fe22Cr alloys was extensively studied in this paper. Weight gain measurements and SEM analysis revealed that pre-oxidation performed at 900◦C for 40 min increased the lifespan of the alloy. A Cr evaporation study did not disclose any significant influence of the pre-oxidation process on the Cr content in the alloy. For a more detailed assessment, TEM imaging and X-ray tomography measurements of...