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Search results for: THERMAL AND NON-THERMAL METHODS
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Thermal degradation of polylactic acid (PLA)/polyhydroxybutyrate (PHB) blends: A systematic review
PublicationPolylactic acid (PLA) and polyhydroxybutyrate (PHB) are two biopolyesters obtained from renewable resources like corn or sugar under bacterial fermentation. PLA is the most widely used biopolymer in diverse applications. Addition of PHB to PLA can improves the crystallinity of PLA, and thereby its mechanical strength. However, both PLA and PHB suffer from poor thermal stability, which limits their potential industrial application....
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New synthesis route of highly porous InxCo4Sb12 with strongly reduced thermal conductivity
PublicationHighly porous, In-filled CoSb3 skutterudite materials with an attractive thermoelectric figure of merit (ZT * 1) and corresponding dense samples were fabricated through the cost-effective method of reduction in oxides in dry hydrogen and the pulsed electric current sintering (PECS) method, respectively. The reduction process was described in detail using in situ thermogravimetric analysis of Co2O3, Sb2O3 and In(NO3)35H2O separately...
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An analysis of solar energy conversion systems based on photon and thermal processes
PublicationSolar spectral irradiance covers a fairly broad wavelength range. Solar radiation is part of the electromagnetic spectrum which is described by the concept of wave-particle duality. The corpuscular theory of electromagnetic radiation states that energy is transmitted by photons. Photons carry specific amounts of energy which can be used to convert solar energy into other types of energy, in particular electricity. The internal...
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Detection of moving objects in images combined from video and thermal cameras
PublicationAn algorithm for detection of moving objects in video streams from the monitoring cameras is presented. A system composed of a standard video camera and a thermal camera, mounted in close proximity to each other, is used for object detection. First, a background subtraction is performed in both video streams separately, using the popular Gaussian Mixture Models method. For the next processing stage, the authors propose an algorithm...
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Investigation of the thermal effects in water-lubricated journal bearings with axial grooves
PublicationWater-lubricated hydrodynamic journal bearings are frequently applied as stern tube bearings due to their advantages over other bearing types. They are environmentally friendly, can operate without sealings and in conditions of low friction losses. The most popular are bearings with open axial grooves, which require, for proper operation, forced axial flow of the lubricating water. Correctly designed and operated stern tube bearings...
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Thermal and hydraulic phenomena in boundary layer of minijets impingement on curved surfaces
PublicationPresented work considers flow and thermal phenomena occurring during the single minijet impingement on curved surfaces, heated with a constant heat flux, as well as the array of minijets. Numerical analyses, based on the mass, momentum and energy conservation laws, were conducted, regarding single phase and two-phase simulations. Focus was placed on the proper model construction, in which turbulence and boundary layer modeling...
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Numerical and experimental investigation of thermal convection near electric devices with vertical channels
PublicationThis paper presents the results of numerical and experimental investigation of thermal convection near heat emitting surfaces of an electric device. For the intensification of thermal convection, special vertical channels were formed near the heat emitting surfaces of the device. An experimental test has proved that there is an optimal length of the channels – thermal convection is the most intensive then. Air velocity vectors...
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Effect of double thermal and electrochemical oxidation on titanium alloys for medical applications
PublicationThe research focuses on the development and characterization of innovative thin hybrid oxide coatings obtained in subsequent processes of thermal (TO) and electrochemical (EO) oxidation. Four different surface modifications were investigated and the microstructure was determined, the mechanical, chemical and biological properties of the Ti-13Nb-13Zr alloy were assessed using scanning electron microscopy, X-ray dispersion analysis,...
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Optimization of thermal backfill configurations for desired high-voltage power cables ampacity
PublicationThe ampacity of high-voltage power cables depends, among others, on their core cross-sectional area as well as thermal resistivity of the thermal backfill surrounding the cables. The cross-sectional area of the power cables’ core is selected according to the expected power to be transferred via the cable system. Usually, the higher the power transfer required, the higher the cross-sectional area of the core. However, the cost of...
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Design analysis of ORC micro-turbines making use of thermal energy of oceans
PublicationThe article presents the results of the analysis of energy conversion cycles making use of thermal energy of oceans. The objects of analysis were two cases of closed Organic Rankine Cycle (ORC) power plants, which were: the cycle in which the vapour of the working medium was produced by warm oceanic water in the circum-equatorial zone, and the so-called “arctic” cycle in which this vapour was produced by non-frozen water in the circumpolar...
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Setups for measurement of thermal time constant of bolometers and resistive layers
PublicationPrzedstawiono dwa układy do pomiaru termicznej stałej czasowejbolometrów i warstw rezystywnych, umożliwiające pomiar wartości tego parametru w zakresie od pojedynczych milisekund do kilku sekund. Przedstawiono wyniki pomiarów termicznej stałej czasowej wybranych warstw rezystywnych wykonanych w technologii LTCC z niestechiometrycznych tlenków lantanowo-strontowo-żelazowych oraz bolometru cienkowarstwowego wykonanego w tej samej...
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Thermal and Strength Properties of Lightweight Concretes with Variable Porosity Structures
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Thermal and strength properties of lightweight concretes with the addition of aerogel particles
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Measurements and numerical simulations of laser hardening and remelting thermal cycles
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Facile and continuous synthesis of graphene nanoflakes in RF thermal plasma
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Secondary Thermal Deformation Characteristics of Stiffened Plate Exposed to Fire
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Thermal and Electrical Characterization of the Carbon Nanofibers Based Cement Composites
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Photochemical and thermal reaction of intermediates in the phenylnitrene rearangment inside a hemicarcerand
PublicationBroadband irradiation (λ > 320 nm) of hemicarceplex H1 between −74 °C and −84 °C, produces encapsulated didehydroazepine (2), triplet phenylnitrene (3PN), 2-azabicyclo[3.2.0]hepta-1,3,6-triene (6), and 4-azaspiro[2.4]hepta-1,4,6-triene (7). The highly strained anti-Bredt imine 6 is formed from 2 via a photochemical four-electron electrocyclization. Under the irradiation conditions, 6 rearranges further to azaspirene 7. In addition,...
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Thermal Barrier as a technique of indirect heating and cooling for residential buildings
PublicationW artykule zaprezentowano koncept pośredniego ogrzewania i chłodzenia budynków mieszkalnych promieniowaniem słonecznym zwany barierą termiczną. System składa się z polipropylenowych rurek umieszczonych w ścianach zewnętrznych, w których znajduje się płyn. Koncept jest zastosowany do stabilizacji i redukcji przepływu ciepła w kierunku prostopadłym do ścian. Wykonano obszerne obliczenia MES z zastosowaniem nowego systemu kontroli,...
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Induction heating laboratory stand for estimating thermal properties of a charge
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Thermal decomposition of surface compounds for the generation of small quantities of acetaldehyde
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Generation of standard gaseous mixtures by thermal decomposition of surface compounds
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Characteristics of Specialised Firefighter Clothing Used in Poland – the Thermal Parameters
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LSCO films for bolometer applications manufactureted without thermal processing.
PublicationPrzedstawiono proces produkcji warstw LSCO przeznaczonych na bolometry IR wykonane technologią nie wymagającą obróbki termicznej.
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Thermal Fatigue Influence of Laser Treated Tool Steel Surface
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Lanthanide metal–organic frameworks: Structural, thermal and sorption properties
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Thermal properties of dense polymer-derived SiCN(O) glasses
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Effect of thermal modifications of potato starch on its selected properties
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Thermal Transitions in P3HT:PC60BM Films Based on Electrical Resistance Measurements
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Thermal and optical properties of PMMA films reinforced with Nb2O5 nanoparticles
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The Investigation of Thermal and Optical Properties of Semiconducting Nanostructural Hybrid Films
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Harmful biological agents in municipal waste thermal treatment plants
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Design and evaluation of a flow-to-frequency converter circuit with thermal feedback
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Photoelectrochemical and thermal characterization of aromatic hydrocarbons substituted with a dicyanovinyl unit
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Thermal, Mechanical, and Morphological Properties of DPU/Titanate Nanotubes Nanocomposites
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Thermal performance of Si and GaAs based solar cells and modules.
PublicationPraca przedstawia aktualny stan wiedzy na temat wpływu temperatury na parametry pracy ogniw i modułów fotowoltaicznych z amorficznego krzemu i GaAs. Przedstawiono ogólna analizę rezultatów zastosowania modułów fotowoltaicznych w budownictwie ze szczególnym uwzględnieniem systemów hybrydowych, przekształcających energie słoneczną w prąd elektryczny i ciepło.
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Thermal Energy Storage with PCMs in Shell-and-Tube Units: A Review
PublicationThe paper presents a survey of the experimental and numerical studies of shell-and-tube systems in which phase change material (PCM) is used. Due to the multitude of design solutions for shell-and-tube systems, the emphasis is placed on double-tube (DT), triplex-tube (TT), and multitube (MT) units. Additionally, only single-pass systems are considered. Particular attention is paid to the method of heat transfer intensification....
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THERMAL ANALYSIS AND DESIGN OF HYBRID MICROCHANNEL-MICROJET TEST PROBE
PublicationThe paper presents the numerical investigation of a microjet- microchannel cooling module. In which microjets of water are impinging into the microchannels and forming a liquid film on the impingement surface. Applied technology takes benefits from two very attractive heat removal techniques. When lminar jets are impinging on the surface have a very high kinetic energy at the stagnation point, also in microchannels boundary layer...
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THERMAL ANALYSIS AND DESIGN OF HYBRID MICROCHANNEL -MICROJET TEST PROBE
PublicationAccurate control of cooling parameters is required in ever wider range of technical applications. It is known that reducing the flow hydraulic diameter to an increase in the economy of cooling and improves its quality (Mikielewicz and Muszyński 2009). Present study describes research results related to the design and construction of the test stand for hybrid microjet- microchannel cooling modules study, which may be applied in...
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Computer-aided analysis of thermal convection near electric devices
PublicationObciążalność długotrwała urządzeń elektrycznych zależy od intensywności oddawania ciepła przez te urządzenia do otoczenia. Dla zwiększenia obciążalności długotrwałej urządzeń stosuje się konwekcję wymuszoną np. z wykorzystaniem wentylatorów. Wszechstronne obserwacje i analiza procesów konwekcji naturalnej wskazują, że jej intensyfikację można uzyskać dzięki umieszczaniu w pobliżu urządzenia oddającego ciepło elementów tworzących...
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Digital Imaging and Communication in Medicine Standard for Breast Thermal Imaging
PublicationOmówiono znaczenie normy DICOM w obrazowaniu medycznym. Zaproponowano metodę opisu danych w diagnostyce terminczej piersi dla potrzeb normy DICOM. Zaprojektowano i wykonano algorytmy automatycznej konwersji danych oraz tworzenia struktur danych w hierarchiczno-obiektowym modelu danych.
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The influence of different time duration of thermal processing on berries quality
PublicationOznaczano zawartość związków bioaktywnych (polifenole, flawonoidy, taniny, antocyjany i kwas askorbinowy) oraz poziom aktywności przeciwutleniającej próbek ekstraktów (wodnych, heksanowych i acetonowych) uzyskanych z różnych gatunków owoców jagodowych. Do pomiaru poziomu aktywności przeciwutleniającej wykorzystano takie testy jak ABTS, DPPH, FRAP i CUPRAC. Zbadano wpływ czasu trwania procesu obróbki termicznej na zawartość bioaktywnych...
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Thermal imaging of skin burns. 9th European Congress of Thermology.
PublicationArtykuł przedstawia wyniki badań in-vivo diagnostyki oparzeń skóry z użyciem metod termograficznych. Wykazano iż na podstawie obrazu termograficznego możliwa jest klasyfikacja głębokości oparzenia.
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Thermal failure of a second rotor stage in heavy duty gas turbine
PublicationThe impulse mode of operation and the supply of various types of fuels causes frequent failures even in the heavy duty gas turbines. The paper presents the ravages of second rotor stage failure in a gas turbine. The excessive thermal elongation rise caused by fuel change was indicated as the main cause. We applied nonlinear numerical analysis, preceded by thermodynamic calculations of the turbine and visual inspection of the effects...
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Polyurethane/Silane-Functionalized ZrO2 Nanocomposite Powder Coatings: Thermal Degradation Kinetics
PublicationA polyurethane (PU)-based powder coating reinforced with vinyltrimethoxysilane (VTMS)-functionalized ZrO2 nanoparticles (V-ZrO2) for thermal stability was developed. Chemical structure, microstructure and thermal degradation kinetics of the prepared coatings were investigated. The peak of aliphatic C–H vibrating bond in the Fourier transform infrared (FTIR) spectrum of V-ZrO2 was a signature of VTMS attachment. Scanning electron...
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Thermal and technological aspects of double face grinding of Al2O3 ceramic materials
PublicationDouble face grinding with planetary kinematics is a process to manufacture workpieces with plan parallel functional surfaces, such as bearing rings or sealing shims. In order to increase the economic efficiency of this process, it has to be advanced permanently. The temperature in the contact zone of most grinding processes has a huge influence on the process efficiency and the workpiece qualities. In contrast to most grinding...
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Super-resolved Thermal Imagery for High-accuracy Facial Areas Detection and Analysis
PublicationIn this study, we evaluate various Convolutional Neural Networks based Super-Resolution (SR) models to improve facial areas detection in thermal images. In particular, we analyze the influence of selected spatiotemporal properties of thermal image sequences on detection accuracy. For this purpose, a thermal face database was acquired for 40 volunteers. Contrary to most of existing thermal databases of faces, we publish our dataset...
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Evaluating Accuracy of Respiratory Rate Estimation from Super Resolved Thermal Imagery
PublicationNon-contact estimation of Respiratory Rate (RR) has revolutionized the process of establishing the measurement by surpassing some issues related to attaching sensors to a body, e.g. epidermal stripping, skin disruption and pain. In this study, we perform further experiments with image processing-based RR estimation by using various image enhancement algorithms. Specifically, we employ Super Resolution (SR) Deep Learning (DL) network...
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Artificial Thermal Ageing of Polyester Reinforced and Polyvinyl Chloride Coated Technical Fabric
PublicationArchitectural fabric AF9032 has been subjected to artificial thermal ageing to determine changes of the material parameters of the fabric. The proposed method is based on the accelerated ageing approach proposed by Arrhenius. 300 mm x 50 mm samples were cut in the warp and fill directions and placed in a thermal chamber at 80 °C for up to 12 weeks or at 90 °C for up to 6 weeks. Then after one week of conditioning at ambient temperature,...
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Processing, mechanical and thermal behavior assessments of polycaprolactone/agricultural wastes biocomposites
PublicationIn this paper, brewer’s spent grain (BSG) was applied as potential lignocellulose biofiller in biocompos-ites based on polycaprolactone (PCL). The PCL/BSG biocomposites filled with varying content of biofillerswere prepared via low-temperature melt-compounding. These conditions allow limiting thermal degra-dation of used biofillers during processing. The influence of biofiller content (ranging from 25 to 200parts by weight on 100...