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Search results for: THERMAL PROPERTIES
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Thermal Decomposition of Carbamoyl Meldrum’s Acids: A Starting Point for the Preparation of 1,3-Oxazine Derivatives
PublicationThe ability to undergo [4 + 2] versus [2 + 2] cycloaddition was under investigation for ketenes thermally generated from carbamoyl Meldrum’s acid. Usually, 1,3-oxazino-5-carbamoylo-4,6-diones are formed when carbamoyl Meldrum’s acid reacts with imine. However, in some cases, a reaction takes an unexpected course, leading to the formation of tetraponerines alkaloids derivatives or cyclic iminoethers.
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Thermal Imaging Aided Assessment of a State of Equipment Under Test and its Protecting Elements
PublicationIn the paper the investigation results using thermal imaging methods are presented. The examined is a state of equipment under test and its protecting components. The estimations are done for the chosen protecting elements during surge immunity testing. The results show that the thermal imaging methods are useful for early detection of possible damage of a device being tested
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Study of thermal property changes of biopol/polyamide 11 blends during biodegradation in compost.
PublicationPrzeprowadzone badania dotyczą zmian struktury krystalicznej podczas biodegradacji mieszanin polimerowych z udziałem PHBV, gdzie zależność między strukturą a podatnością na biodegradację związane są nie tylko ze stopniem krystaliczności PHBV ale także z budową faz składników mieszaniny. Wyniki pozwalają stwierdzić, że mieszaniny PA11/PHBV zawierające 60% kopoliestru PHBV(otrzymane przy użyciu wytłaczarki dwuślimakowej) charakteryzują...
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Analysis of transient thermal processes for improved visualization of breast cancer using IR imaging.
PublicationPrzedstawiono analizę możliwości i ograniczeń metod termograficznych w diagnostyce nowotworów piersi. Przeanalizowane termiczne modele numeryczne piersi z nowotworem pokazują, iż zastosowanie nowej metody aktywnej termografii dynamicznej z termicznym wymuszeniem zewnętrznym, może znacząco poprawić skuteczność wykrywania nowotworów piersi we wczesnym stadium ich rozwoju . Pokazano również wyniki badania klinicznego pacjentki...
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Compensation of thermal deformations as a method of improving performance of large tiling pad thrust bearings.
PublicationTermiczne odkształcenia klocków łożyskowych wywierają niekorzystny wpływ na właściwości łozysk o dużych średnicach. W pracy przedstawiono przegląd znanych z techniki sposobów ograniczania odkształceń termicznych.Na podstawie wyników własnych badań szczegółowo omówiono efekty kompensacji odkształceń w dwóch przykładowych rozwiązaniach konstrukcyjnych: łożysku z klockami podpartymi na sprężynach śrubowych i z klockami podpartymi...
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Application of artificial neural networks (ANN) as multiple degradation classifiers in thermal and flow diagnostics
PublicationPrzedyskutowano problem zwiększenia dokładności rozpoznawania wielokrotnych degradacji eksploatacyjnych urządzeń składowych dużych obiektów energetycznych. Zastosowani sieć neuronową (SSN) o skokowych funkcjach przejścia. Sprawdzono możliwości przyspieszenia treningu sieci neuronowych. Zastosowano modułową metodę budowy SSN, polegającą na dedykowaniu pojedynczej sieci do rozpoznawania tylko jednego typu degradacji.
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Indoor Air Quality and Thermal Comfort in Naturally Ventilated Low-Energy Residential Houses
PublicationRozdział omawia jakość powietrza i termiczny komfort w naturalnie wentylowanych energooszczędnych budynkach mieszkalnych. Obliczenia wykonano metoda elementów skończonych dla wentylacji naturalnej. Uwzględniono 2 różne położenia wlotów powietrza oraz system grzewczy kaloryferowy i podłogowy. Wyniki MES porównano z doświadczeniami.
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New Transparent Flame-Retardant (FR) Coatings Based on Epoxy-Aluminum Hypophosphite Nanocomposites
PublicationThe present study investigated the flame-retardant (FR) effect of transparent epoxy coating containing aluminum hypophosphite (AHP) nanoparticles (NPs) on polylactic acid (PLA) sheets used as a typical model of combustible polymeric material. First, AHP NPs (≤60 nm) were prepared by a specific two-stage wet milling process and deeply analyzed (morphology, thermal/mechanisms of degradation under nitrogen and air). The thermal properties...
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Novel tetrahedral cobalt(II) silanethiolates: structures and magnetism
PublicationThree heteroleptic complexes of Co(II) tri-tert-butoxysilanethiolates have been synthesized with piperidine [Co{SSi(OtBu)3}2(ppd)2] 1, piperazine [Co{SSi(OtBu)3}2(NH3)]2(μ-ppz)·2CH3CN 2, and N-ethylimidazole [Co{SSi(OtBu)3}2(etim)2] 3. The complexes have been characterized by a single-crystal X-ray, revealing their tetrahedral geometry on Co(II) coordinated by two nitrogen and two sulfur atoms. Complexes 1 and 3 are mononuclear,...
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Energy conversion in systems-contained laser irradiated metallic nanoparticles - comparison of results from analytical solutions and numerical methods
PublicationThis work introduces the theoretical method of metallic nanoparticles’ (NPs’) heat and mass transfer where the particles are coated on a surface (base), together with considering the case wherein nanoparticles move freely in a pipe. In order to simulate the heat transfer, energy and radiative transfer equations are adjusted to the considered issue. NPs’ properties are determined following the nanofluidic theories, whereas absorption...
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Numerical analysis of crack propagation in silicone nitride
PublicationThe properties of ceramics, specifically low density, high hardness, high temperature capability and low coefficient of thermal expansion are of most interest to rolling element manufacturers. The influence of ring crack size on rolling contact fatigue failure has been studied using numerical fracture analysis. Such cracks are very often found on ceramic bearing balls and decrease fatigue life rapidly. The numerical calculation...
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Anion binding by p-aminoazobenzene-derived aromatic amides: spectroscopic and electrochemical studies
PublicationThe synthesis and complexing properties of p-aminoazobenzene-derived mono-, bis-, and trisamides were described. Ligands 3 and 4 bind anions, including fluorides, chlorides, bromides, acetates, benzoates, dihydrogen phosphates, hydrogen sulfates, and p-toluenesulfonates, in chloroform forming 1 : 1 complexes. The highest value of stability constant was evaluated for the 4-F− complex (log K = 5.63 ± 0.21). On the basis of 1H NMR,...
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Transition Metal Oxides influence on phosphate and borate glasses structure
PublicationBorate and phosphate glasses possess many potential luminescence and optical applications. With their low melting point, they are one of the most often studied amorphous materials. In recent years these glasses, doped with transition metal oxides (TMO), gained much attention due to their tunable structural and thermal properties. Review of systems containing TMOs was presented. Additionally synthesis of binary MnO-P2O5 and MnO-B2O3...
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The effect of hybridization of fire retarded epoxy/flax-cotton fiber laminates by expanded vermiculite: Structure-property relationship study
PublicationThe study describes the hybridization of epoxy/flax-cotton (EP/FF) composites containing ammonium polyphosphate (APP) with micrometric expanded vermiculite (VMT) (1–10 wt%). The efficiency of hybridization of flame retarded epoxy/flax-cotton composites was assessed by performing static tensile and flexural strength evaluation, supplemented by impact strength measurements of the composites. Moreover, thermal and thermomechanical...
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Segmented bio-based polyurethane composites containing powdered cellulose obtained from novel bio-based diisocyanate mixtures
PublicationA considerable number of research works focus on the positive influence of cellulose on the properties of polymer-based composites and their wide range of application possibilities. The present work is focused on the synthesis of novel bio-based polyurethane (bio-PU) composites filled with powdered cellulose (microcellulose, MC) in an amount of 5 wt.%. Bio-PU composites were synthesized via a non-solvent prepolymer method. First,...
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Photoinduced K+ Intercalation into MoO3/FTO Photoanode—the Impact on the Photoelectrochemical Performance
PublicationIn this work, thin layers of MoO3 were tested as potential photoanodes for water splitting. The influence of photointercalation of alkali metal cation (K+) into the MoO3 structure on the photoelectrochemical properties of the molybdenum trioxide films was investigated for the first time. MoO3 thin films were synthesized via thermal annealing of thin, metallic Mo films deposited onto the FTO substrate using a magnetron sputtering...
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Softwood-lignin/natural rubber composites containing novel plasticizing agent: Preparation and characterization
PublicationComposite materials based on natural rubber were obtained by using glycerolysate (decomposition prod- uct of polyurethane) as a novel plasticizer. In order to determine the effect of various lignin content, four different filler amounts were used, namely, 5 phr (parts per 100 parts of natural rubber) of lignin (WLI5G), 10 phr (WLI10G), 20 phr (WLI20G), and 40 phr (WLI40G). The reference specimen without lignin (WLI0G) was also...
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Non-Isocyanate-Based Waterborne Polyurethanes
PublicationNon-isocyanate polyurethanes (NIPUs) are a greener alternative for the conventional polyurethanes synthesized using toxic and moisture-sensitive di- or polyisocyanates. The most often described method of NIPU synthesis involves the reaction of five-membered cyclic carbonates with amines, and resulting polymers containing primary and secondary hydroxyl groups (so they are also known as polyhydroxyurethanes), which can be further...
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Impact of the anion and chalcogen on the crystal structure and properties of 4,6-dimethyl-2-pyrimido(thio)nium halides
PublicationBy the reaction of urea or thiourea, acetylacetone and hydrogen halide (HF, HBr or HI), we have obtained seven new 4,6-dimethyl-2-pyrimido(thio)nium salts, which were characterized by single-crystal X-ray diffraction, namely, 4,6-dimethyl-2-oxo-2,3-dihydropyrimidin-1-ium bifluoride, C₆H₉N₂O⁺·HF₂⁻ or (dmpH)F₂H, 4,6-dimethyl-2-oxo-2,3-dihydropyrimidin-1-ium bromide, C₆H₉N₂O⁺·Br⁻ or (dmpH)Br, 4,6-dimethyl-2-oxo-2,3-dihydropyrimidin-1-ium...
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RESEARCH OF HYDRAULIC PISTON PUMPS’ START-UP IN LOW AMBIENT TEMPERATURES
PublicationStarting hydraulic pumps in low ambient temperatures may cause: decreased hydraulic-mechanical efficiency, larger vibration of hydraulic installation, faster wear and more frequent damage to the elements of pumps, change of material properties of elements, increase of pressure drop. As a result of increase of resistance of cold oil flow in the suction pipe, large underpressure may be experienced, causing incomplete filling of pump...
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Manufacture and research of TPS/PE biocomposites properties
PublicationIn this paper the process of native starch preparing for modification by extrusion and manufacture of biocomposites is presented. The first aim of this study was to determine the mixing and granulating condition of native starch to obtain granulated native starch. For mixing and granulation of native starch Intensive Mixer manufactured by Maschinenfabrik Gustav Eirich was used. Mixing and granulation in a single process is a new...
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Utilization of ionic liquids for the enrichment of biogas
PublicationThis article discusses the dependence of biogas composition on organic feed material. High amounts of CO2 decrease the calorific value of biogas. Several technologies are reviewed which can be used to increase the calorific value. Special emphasis is laid on ionic liquids as a new absorbing material. ILs have a number of advantages due to their unique properties such as: low melting point, high thermal conductivity, no flammability,...
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Thermal visualization of Ostwald-de Waele liquid in wavy trapezoidal cavity: Effect of undulation and amplitude
PublicationThe present study is concerned with the numerical simulations of Ostwald-de Waele fluid flow in a wavy trapezoidal cavity in the presence of a heated cylinder situated at the center of the cavity. The work consists in characterizing the mixed convection as a function of the intensity of heat flow. The flow behaviour and temperature distribution in a cavity are the main focus of this study. The lower wall of the cavity is fixed...
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Betaine and L-carnitine ester bromides: Synthesis and comparative study of their thermal behaviour and surface activity
PublicationSix esters of both betaine and L-carnitine bromides, featuring alkyl groups ranging from C8 to C18 in length, have been synthesized. The thermal behaviour of these twelve bio-based salts has been analyzed and compared by thermal gravimetric analysis and differential scanning calorimetry. The L-carnitine alkyl ester bromides melted below 100 C and can hence be considered ionic liquids (ILs) with full rights. Conversely, the betaine...
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Thermal Images Analysis Methods using Deep Learning Techniques for the Needs of Remote Medical Diagnostics
PublicationRemote medical diagnostic solutions have recently gained more importance due to global demographic shifts and play a key role in evaluation of health status during epidemic. Contactless estimation of vital signs with image processing techniques is especially important since it allows for obtaining health status without the use of additional sensors. Thermography enables us to reveal additional details, imperceptible in images acquired...
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Nonlocal elasticity analysis of moderately thick porous functionally graded plates in a hygro-thermal environment
PublicationThis work performs a novel quasi three-dimensional (3D) bending analysis for a moderately thick functionally graded material (FGM) made of nanoceramics and metal powders, in presence of porosities due to some incorrect manufacturing processes. Such porosities can appear within the plate in two forms, namely, even and uneven distributions. The modeled system assumes a polymer matrix where both shear and transverse factors coexist....
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The Impact of Thermal Stresses on Volume Resistivity: Performance Comparison between TR-XLPE and XLPE Cables
PublicationMost failures in electric power cables are attributed to the development of water trees inside the insulating materials. Thus, the development and utilization of Tree Retardant Cross-Linked Polyethylene (TR-XLPE) based cables have recently been given great attention to overcome the treeing issues. TR-XLPE cables use low-density polyethylene compounds suppressing the formation of water trees while retaining excellent electrical,...
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Effect of Metal and Carbon Nanotube Additives on the Thermal Diffusivity of a Silica Gel-Based Adsorption Bed
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Enhancement of Thermal Stability, Conductivity and Smoke Suppression of Polyethylene Composites with Exfoliated MoS2 Functionalized with Magnetite
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Luminescence enhancement in nanocrystalline Eu2O3 nanorods – Microwave hydrothermal crystallization and thermal degradation of cubic phase
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Hybrid Processing: the Impact of Mechanical and Surface Thermal Treatment Integration onto the Machine Parts Quality
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Elucidation of the effect of some cholinium amino acid ionic liquids on the thermal and the conformational stability of insulin
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Thermal processing of pasta enriched with black locust flowers affect quality, phenolics, and antioxidant activity
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Aluminide Thermal Barrier Coating for High Temperature Performance of MAR 247 Nickel Based Superalloy
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Thermal Aging of Heterophasic Propylene−Ethylene Copolymers: Morphological Aspects Based on ESR, FTIR, and DSC
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Effect of pyrolysis temperature on the microstructure and thermal conductivity of polymer-derived monolithic and porous SiC ceramics
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Effect of nanosized carbon black on thermal stability and flame retardancy of polypropylene/carbon nanotubes nanocomposites
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Diamond surface modification following thermal etching of Si supported hydrogenated diamond films by DBr
PublicationZbadano, wykorzystując spektroskopię oscylacyjną (HREELS - High Resolution Electron Energy Loss Spectroscopy) modyfikacje chemiczne powierzchni wodorowanego diamentu, umieszczonego na podkładzie krzemowym i wystawionego na działanie DBr a następnie podgrzanego do temp. powyżej 600 st.K. Przedstawiona procedura powoduje tworzenie się węglika krzemu SiC na powierzchni warstwy diamentowej, co jest widoczne na widmie HREEL jako dwa...
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CdS thin films obtained by thermal treatment of cadmium(II) complexprecursor deposited by MAPLE technique
PublicationCienkie warstwy kompleksu [Cd{SSi(O-But)3}(S2CNEt2)]2 zostały osadzone na podłożach Si przy użyciu techniki MAPLE (ablacja laserowa z zamrożoną matrycą). Otrzymanie warstw CdS było możliwe dzięki zastosowaniu obróbki termicznej podłoży z naniesionym prekursorem. Powierzchnia filmów była analizowana pod kątem morfologii przy użyciu mikroskopii sił atomowych (AFM) oraz pomiarów elipsometrycznych (SE).
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Structure and superconductivity of VN-SiO2 films obtained by thermal nitridation of sol-gel derived coatings
PublicationPraca prezentuje wyniki badań strukturalnych oraz właściwości nadprzewodzących cienkich warstw xVN-(100-x)SiO2, gdzie x = 90, 80, 70, 60 mol%. Warstwy zostały wykonane metodą termicznego azotowania z użyciem amoniaku cienkich warstw tlenkowych otrzymanych metodą zol-żel. Badania struktury przeprowadzono metodami XRD oraz XPS, natomiast właściwości nadprzewodzące badano metodą MMMA. Właściwości nadprzewodzące warstw zależą zarówno...
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The influence of local temperature and air velocity changes on the thermal sensations of users' working in surgical clothing
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A novel hybrid composites based on biopolyamide 10.10 with basalt/aramid fibers: Mechanical and thermal investigation
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Thermal visualization of Ostwald-de Waele liquid in wavy trapezoidal cavity: Effect of undulation and amplitude
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Recycled polyethylene and crumb rubber composites modified asphalt with improved aging resistance and thermal stability
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A Model of Thermal Energy Storage According to the Convention of Bond Graphs (BG) and State Equations (SE)
PublicationThe main advantage of the use of the Bond Graphs method and State Equations for modeling energy systems with a complex structure (marine power plants, hybrid vehicles, etc.) is the ability to model the system components of different physical nature using identical theoretical basis. The paper presents a method of modeling thermal energy storage, which is in line with basic BG theory. Critical comments have been put forward concerning...
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Recycled Polyurethane as a Second Phase in Thermoset Blends and Its Effect on Thermal Degradation Kinetics Studies
PublicationA new approach is introduced in the modification of thermosetting polymer by using different amount of polyurethane of waste origin. The post consumer polyurethane foam coatings are degraded using glycolysis process and the recycled product is further converted into new polyurethane. The blending of recycled polyurethane with epoxy exhibits transparency and produces nanostructures. The effective interaction between two polymers...
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ATTEMPTS OF THERMAL IMAGING CAMERA USAGE IN ESTIMATIONS OF THE CONVECTIVE HEAT LOSS FROM A VERTICAL PLATE
PublicationIn this paper a new method for determining heat transfer coefficients using a gradient method has been developed. To verify accuracy of the proposed method vertical isothermal heating plate with natural convection mechanism has been examined. This configuration was deliberately chosen, because of the fact that such case is historically the earliest and most thoroughly studied and its rich scientific documentation - the most reliable....
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CAUSALITY IN MODELS OF THERMAL PROCESSES IN SHIP ENGINE ROOMS WITH THE USE OF BOND GRAPH (BG) METHOD
PublicationWith a single approach to modeling elements of different physical nature, the method of Bond Graph (BG) is particularly well suited for modeling energy systems consisting of mechanical, thermal, electrical and hydraulic elements that operate in the power system engine room. The paper refers to the earlier presented new concept of thermal process modeling using the BG method. The authors own suggestions for determining causality...
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Quantitative study of free convective heat losses from thermodynamic partitions using Thermal Imaging
PublicationThe following paper presents a simple method of determining the presence, distribution and values of heat losses from external building walls as thermodynamic partitions using a Thermal Imaging Camera (TIC). According to Fourier's equation, the value of heat loss is proportional to the temperature gradient ∂t/∂y|y=0 in air in the y direction perpendicular to the heated surface. Unfortunately, air temperature cannot be measured...
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Improving Accuracy of Contactless Respiratory Rate Estimation by Enhancing Thermal Sequences with Deep Neural Networks
PublicationEstimation of vital signs using image processing techniques have already been proved to have a potential for supporting remote medical diagnostics and replacing traditional measurements that usually require special hardware and electrodes placed on a body. In this paper, we further extend studies on contactless Respiratory Rate (RR) estimation from extremely low resolution thermal imagery by enhancing acquired sequences using Deep...