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Superconductivity in the niobium-rich compound Nb5Se4
PublikacjaThe niobium rich selenide compound Nb5Se4 was synthesized at ambient pressure by high-temperature solid–state reaction in a sealed Ta tube. Resistivity and heat capacity measurements reveal that this compound is superconducting, with a Tc = 1.85K. The electronic contribution to the specific heat γ and the Debye temperature are found to be 18.1 mJmol−1K−2 and 298 K respectively. The calculated electron-phonon coupling constant λep...
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Implementation of the Boundary Element Method to Two-Dimensional Heat Transfer with Thermal Bridge Effects
PublikacjaThe work presents an application of the boundary element method applied to a two-dimensional conductive heat transfer. The algorithm of the method is explained and its advantages are outlined. Green's function as a fundamental solution for Poisson's equation in two dimensions was used and the direct approach was applied. The presented results concern building construction elements as typical cases of thermal bridges. Some properties...
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Numerical simulation of hardening of concrete plate
PublikacjaThe paper presents a theoretical formulation of concrete curing in order to predict temperature evolution and strength development. The model of heat flow is based on a well-known Fourier equation. The numerical solution is implemented by means of the Finite Difference Method. In order to verify the model, the in situ temperature measurements at the top plate of a road bridge were carried out. A high agreement between numerical...
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Investigations on mixture preparation for two phase adiabatic pressure drop of R134a flowing in 5 mm diameter channel
PublikacjaThe article presents detailed two-phase adiabatic pressure drops data for refrigerant R134a. Study cases have been set for a mass flux varying from 200 to 400 kg/m2 s, at the saturation temperature of 19.4 ◦C. Obtained experimental data was compared with the available correlations from the literature for the frictional pressure drop during adiabatic flow. Influence of mixture preparation on pressure drop was investigated, for...
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Tunable Dielectric Switching of (Quinuclidinium)[MnCl4] Hybrid Compounds
PublikacjaInorganic−organic hybrid QMnCl (Q = quinuclidinium) crystals were synthesized and characterized. The X-ray and variable-temperature IR/Raman analysis demonstrate that the crystals undergo a reversible structural phase transition, which originates from an order−disorder process and is related to the dynamics of the organic Q cation. Dielectric function measurements disclose a switchability between low (“OFF”) and high (“ON”) dielectric...
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Solubility of carbon dioxide in water: Some useful results for hydrate nucleation
PublikacjaIn this paper, the solubility of carbon dioxide (CO2) in water along the isobar of 400 bar is determined by computer simulations using the well-known TIP4P/Ice force field for water and the TraPPE model for CO2. In particular, the solubility of CO2 in water when in contact with the CO2 liquid phase and the solubility of CO2 in water when in contact with the hydrate have been determined. The solubility of CO2 in a liquid–liquid...
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Fermi-liquid behavior of binary intermetallic compounds Y3 M (M = Co, Ni, Rh, Pd, Ir, Pt)
PublikacjaA series of polycrystalline samples of Y3 M (M = Co, Ni, Rh, Pd, Ir, Pt), intermetallic binary compounds were synthesized by the arc-melting method. Powder x-ray diffraction (pXRD) confirmed the orthorhombic cementite-type crystal structure and allowed for the estimation of the lattice parameters. Physical properties were investigated by means of electrical resistivity and heat capacity measurements between 1.9 K and 300 K. All...
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Advanced Turbine Cycles with Organic Media
PublikacjaOrganic Rankine Cycle (ORC) power plants have become very popular and have found their applications in systems with renewable sources of energy. So far their overall efficiencies are not very impressive and only for the upper temperature of about 300 °C do they exceed 20%. A drawback of these cycles is the limitation of the cycle upper temperature due to the heat exchanger technology and the materials used. However, it is possible...
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Different design aspects of an Organic Rankine Cycle turbine for electricity production using a geothermal binary power plant
PublikacjaIn recent years, pressure has been growing to increase the share of renewable energy sources in electricity generation, which may offer opportunities for the development of geothermal energy in regions that have been so far considered unprofitable in this respect. One such country currently undergoing an energy transition is Poland in which low-temperature geothermal resources are currently used for district heating and recreation...
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Analysis of the Heating Process of Hydraulic Motors during Start-Up in Thermal Shock Conditions
PublikacjaConditions that prevail during harsh winters and hot summers pose a serious challenge for machine designers building devices suitable for operation in extreme weather. It is essential for the designers and the users to define the principles and conditions for the safe operation of machines and devices with hydraulic drive in low ambient temperatures. Bearing in mind the above, the author tested the hydraulic motors in thermal shock...
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Steady magnetohydrodynamic flow in a diverging channel with suction or blowing
PublikacjaAn analysis is made of steady two-dimensional divergent flow of an electrically conducting incompressible viscous fluid in a channel formed by two non-parallel walls, the flow being caused by a source of fluid volume at the intersection of the walls. The fluid is permeated by a magnetic field produced by an electric current along the line of intersection of the channel walls. The walls are porous and subjected to either suction...
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Heat Transfer of the Multicolor-Laser-Sources-Irradiated Nanoparticles in Reference to Thermal Processes
PublikacjaUnlike the standard materials, metallic nanoparticles offer enhancing the heat convertion rate which implies the maximum and average temperature boost significantly in the considered system. The work’s purpose is to examine heat transfer in the metallic nanoparticles which have been deposited on a glassy substrate, enabling the nanostructures thermoablation. Furthermore, the functionalized substrate is irradiated with multicolor-laser-sources,...
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Uncertainty of antioxidant profiling in complex mixtures using liquid chromatography involving post-column derivatisation
PublikacjaThe main goal of this paper is to discuss the problems associated with antioxidant profiling in complex samples using a high-throughput HPLC system coupled with post-column derivatisation reactor. Based on the experimental data reported in the literature, we demonstrated that improper optimisation of temperature and/or pH assay conditions performed using an on-line derivatisation reactor may substantially change the antioxidant...
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Fractographical quantitative analysis of EN-AW 2024 aluminum alloy after creep pre-strain and LCF loading
PublikacjaThis paper explores the applicability of a new damage parameter combining both fracture surface topography and loading features to estimate the fatigue lifetime under creep pre-strain and low-cycle fatigue loading. Fractures of EN-AW 2024 aluminum alloy caused by mixed creep and low-cycle fatigue loading are experimentally characterized and quantified via surface topography analysis. The specimens were preliminary damaged in a...
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Applying molecular dynamics simulation to take the fracture fingerprint of polycrystalline SiC nanosheets
PublikacjaGraphene-like nanosheets are the key elements of advanced materials and systems. The mechanical behavior of the structurally perfect 2D nanostructures is well documented, but that of polycrystalline ones is less understood. Herein, we applied molecular dynamics simulation (MDS) to take the fracture fingerprint of polycrystalline SiC nanosheets (PSiCNS), where monocrystalline SiC nanosheets (MSiCNS) was the reference nanosheet....
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SZACOWANIE ZAWARTOŚCI BENZO(a)PIRENU W PYLE ZAWIESZONYM PM10 W AGLOMERACJI TRÓJMIEJSKIEJ ZA POMOCĄ WIELOWYMIAROWEJ REGRESJI LINIOWEJ=ESTIMATION OF BENZO(A)PYRENE CONTENT IN SUSPENDED DUST PM10 IN TRI-CITY AGGLOMERATION USING MULTIDIMENSIONAL LINEAR REGRESSION
PublikacjaW pracy przedstawiono próbę oszacowania przy pomocy wielowymiarowej regresji liniowej modelu empirycznego opisującego czynniki wpływające na zawartość B(a)P w pyle zawieszonym PM10 w Aglomeracji Trójmiejskiej w latach 2008-2011. Na przestrzeni tych lat średnioroczne stężenie B(a)P w PM10 wzrosło ponad dwukrotnie i ponad trzykrotnie przewyższa poziom docelowy. Z przeprowadzonych analiz wynika, że główną przyczyną wzrostu stężenia...
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Silicon carbide application issues
PublikacjaThe main goals of Task 3 and Task 4 of the ordered project ''New technologies based on silicon carbide and their application in HF, high power and high temperature electronics'' are presented
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Predicting the viscosity and electrical conductivity of ionic liquids on the basis of theoretically calculated ionic volumes
PublikacjaSelected physical properties of the ionic liquids might be quantitatively predicted based on the volumes of the ions these systems are composed of. It is demonstrated that the ionic volumes calculated using relatively simple theoretical quantum chemistry methods can be utilised to estimate the viscosities and electrical conductivities of various commonly used ionic liquids. The fitting formulas of the exponential form are offered...
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Implementation of TVDI calculation for coastal zone
PublikacjaPaper will show an implementation of TVDI (Temperature-Vegetation-Dryness Index) algorithm on GPU (Graphics Processing Unit). Calculation of this index is based on LST (Land Surface Temperature) and NDVI (Normalized Difference Vegetation Index). Discussed results are based on multi-spectral imagery retrieved from AVHRR3 sensors for area of Poland, especially from region of Gdańsk coastal zone. All phases of TVDI implementation...
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A measurement system for children endurance tests
PublikacjaThere are a lot of ethical problems concerning the use of invasive methods for the measurement of a child's body response to physical exercise and physical training. The alternative is are non-invasive methods like ergospirometry or NIRS. The article presents a measurement system dedicated for children endurance tests, composed of a few non-invasive measurement modules, including a temperature measurement module. Temperature is...
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Structure and thermal expansion of liquid bismuth
PublikacjaExperimental structural data for liquid Bi were used for estimation of the main structure parameters as well as the thermal expansion coefficient both in supercooled and superheated temperature ranges. It was shown that the equilibrium melt had a positive thermal expansion coefficient within a temperature range upon melting and a negative one at higher temperatures. The former was related to structure changes upon melting, whereas...
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Development and application of asphalt binder relaxation test in different dynamic shear rheometers
PublikacjaIn this study, a novel relaxation test is proposed to evaluate asphalt binder low temperature properties using a Dynamic Shear Rheometer (DSR) with parallel plates of 4 mm in diameter. Three rheometers from three different manufacturers are used to analyze seven asphalt binders. Different material parameters are derived which are useful to evaluate and discriminate different asphalt binders. Test results of all three instruments...
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The electronic characterization of the cubic Laves-phase superconductor CaRh2
PublikacjaWe present the synthesis and experimental characterization of the electronic properties of the cubic Laves phase superconductor CaRh2. Its crystal structure was confirmed by powder X-ray diffraction and its ambient temperature lattice parameter (a = 7.5326(6) Å) is in good agreement with the literature. Magnetization, resistivity and heat-capacity measurements indicate that CaRh2 is a moderate-coupling type-II superconductor (λe-p = 0.89)...
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Cleaner energy for sustainable future using hybrid photovoltaics-thermoelectric generators system under non-static conditions using machine learning based control technique
PublikacjaIn addition to the load demand, the temperature difference between the hot and cold sides of the thermoelectric generator (TEG) module determines the output power for thermoelectric generator systems. Maximum power point tracking (MPPT) control is needed to track the optimal global power point as operating conditions change. The growing use of electricity and the decline in the use of fossil fuels have sparked interest in photovoltaic-TEG...
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Energy consumption optimization in wastewater treatment plants: Machine learning for monitoring incineration of sewage sludge
PublikacjaBiomass management in terms of energy consumption optimization has become a recent challenge for developed countries. Nevertheless, the multiplicity of materials and operating parameters controlling energy consumption in wastewater treatment plants necessitates the need for sophisticated well-organized disciplines in order to minimize energy consumption and dissipation. Sewage sludge (SS) disposal management is the key stage of...
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Ionic thermoelectric effect in Cu2-δSe during phase transition
PublikacjaThe ionic Seebeck coefficient was studied in copper selenide with Cu1.99Se, Cu1.95Se and Cu1.8Se stoichiometry which was synthesized with a melt crystallization method. To measure the ionic Seebeck coefficient of copper ions, 0.15C6H12N4CH3I + 0.85CuI solid-state electrolyte was prepared. Electrolyte layers were pressed with copper selenide powder into a sandwich-like structure. At the temperature of 410 K, the materials have ionic...
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Electro-thermal buckling of elastically supported double-layered piezoelectric nanoplates affected by an external electric voltage
PublikacjaPurpose Thermal buckling of double-layered piezoelectric nanoplates has been analyzed by applying an external electric voltage on the nanoplates. The paper aims to discuss this issue. Design/methodology/approach Double-layered nanoplates are connected to each other by considering linear van der Waals forces. Nanoplates are placed on a polymer matrix. A comprehensive thermal stress function is used for investigating thermal buckling....
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The Characteristic of Surface Layers on Austenitic Stainless SteelAfter Glow-discharge Nitriding Process.
PublikacjaThis paper presents investigation of surface layers. The diffusion layers were produced by using different parameters of reactive atmosphere (N2:H2). The research of the surface layers was performed using scanning electron microscope (SEM). The results of energy dispersive X-ray (EDX) analysis and X-ray diffraction (XRD) analysis are presented. Research reveals the influence of chemical constitution of reactive atmosphere on the...
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Impact of Climate Change on Groundwater Resources in a Young Glacial Multi-Aquifer System
PublikacjaThe aim of this study was to evaluate the trends of climate change on the Kashubian Lake District and to determine the impact of expected trends on groundwater resources. The analysis of trends in temperature and precipitation was conducted for the six-decade history of meteorological measurements at the weather station in Koscierzyna. The analysis shows the trend of temperature increase of +0.0182ºC/year. The highest increase...
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Electrochemical performance of Co3O4/CeO2 electrodes in H2S/H2O atmospheres in a proton-conducting ceramic symmetrical cell with BaZr0.7Ce0.2Y0.1O3 solid electrolyte
PublikacjaThe electrochemical performance of Co3O4/CeO2 mixed oxide materials as electrodes, when exposed to H2S/H2O atmospheres, was examined employing a proton conducting symmetrical cell, with BaZr0.7Ce0.2Y0.1O3 (BZCY72) as the solid electrolyte. The impact of temperature (700–850 °C) and H2S concentration (0–1 v/v%) in steam-rich atmospheres (90 v/v% H2O) on the overall cell performance was thoroughly assessed by means of electrochemical...
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Experimental study and comparison with predictive methods for flow boiling heat transfer coefficient of HFE7000
PublikacjaThis article describes an experimental study of flow boiling of HFE7000 inside a smooth vertical channel. The investigation has been carried out in a circular stainless-steel tube with an inner diameter of 2.3 mm. The data have been collected for the applied heat fluxes q ranging from 61 to 205 kW/m2, the mass flux G ranging from 214 to 1006 kg/(m2 s), the saturation temperature Tsat ranging from 30 to 54 °C and the full range...
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Deep learning based thermal image segmentation for laboratory animals tracking
PublikacjaAutomated systems for behaviour classification of laboratory animals are an attractive alternative to manual scoring. However, the proper animals separation and tracking, especially when they are in close contact, is the bottleneck of the behaviour analysis systems. In this paper, we propose a method for the segmentation of thermal images of laboratory rats that are in close contact during social behaviour tests. For this, we are...
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The Proposition of an Automated Honing Cell with Advanced Monitoring
PublikacjaHoning of holes allows for small shape deviation and a low value of a roughness profile parameter, e.g., Ra parameter. The honing process heats the workpiece and raises its temperature. The increase in temperature causes thermal deformations of the honed holes. The article proposes the construction of a honing cell, containing in addition to CNC honing machine: thermographic camera, sound intensity meter, and software for collecting...
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Unprecedented Adhesive Performance of Propylene-Based Hydroxyl Functionalized Terpolymers
PublikacjaThe synthesis of hydroxyl functionalized propylene-based terpolymers and their performance as hot melt adhesives were investigated. The products comprise uniformly distributed butyl and 4-hydroxyl-butyl branches along the polypropylene backbone. Despite the low hydroxyl-functionality level of ≤ 0.5 mol%, hydroxyl functionalized terpolymers show formidable adhesion to aluminum and steel providing an adhesive strength exceeding 16...
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Detection and Model of Thermal Traces Left after Aggressive Behavior of Laboratory Rodents
PublikacjaAutomation of complex social behavior analysis of experimental animals would allow for faster, more accurate and reliable research results in many biological, pharmacological, and medical fields. However, there are behaviors that are not only difficult to detect for the computer, but also for the human observer. Here, we present an analysis of the method for identifying aggressive behavior in thermal images by detecting traces...
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WSPÓŁPRACA BLOKU GAZOWO-PAROWEGO Z OBIEGIEM ORC = Combinded power plant in cooperation with ORC
PublikacjaIn the paper presented is the idea of a combined gas and steam power plant cooperation with a low temperature organic Rankine cycle ORC unit. Considerations presented in the paper are accomplished for the Gorzów CHP. The intention of present analysis is heat recovery of low temperature energy and its further use in ORC cycle in order to produce electricity, without increase in fuel consumption. Waste energy is recovered from the...
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Properties of Nasicon-based CO2 sensors with Bi8Nb2O17 reference electrode
PublikacjaPotentiometric CO2 sensors based on Nasicon (Na+ conductor, Na3Zr2Si2PO12) electrolyte, Bi8Nb2O17/Pt reference electrode and different sensing electrodes have been prepared. Besides the sensing electrode material, sensors differ from each other in the reference electrode preparation technique. The main aim of this study is to investigate sensor construction and electrode fabrication process influence on sensor properties. The optimal...
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The domination of ionic conductivity in tetragonal phase of the organometal halide perovskite CH3NH3PbI3-xClx
PublikacjaOrganometal trihalide perovskites have recently gained extreme attention due to their high solar energy conversion in photovoltaic cells. Here, we investigate the contribution of iodide ions to a total conductivity of the mixed lead halide perovskite CH3NH3PbI3−xClx with a use of the modified DC Hebb–Wagner polarization method. It has been identified that an ionic conductivity dominates in tetragonal phase which is associated with room...
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Evaluation of apparent Young׳s modulus of the composite polymer layers used as sliding surfaces in hydrodynamic thrust bearings
PublikacjaHydrodynamic bearings with a polymer sliding layer are able to operate in severe conditions, mainly due to favorable properties of the polymers. The goal of this research was to evaluate apparent Young׳s modulus of two types of the polymer composite layers used for sliding surfaces in hydrodynamic bearings, as a function of temperature. The Young׳s modulus was evaluated on the basis of compression tests carried out on samples obtained...
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THE EFFECT OF WOOD DRYING METHOD ON THE GRANULARITY OF SAWDUST OBTAINED DURING THE SAWING PROCESS USING THE FRAME SAWING MACHINE
PublikacjaThe experimental results of the study focused on the effect of drying processes of warm air drying at the temperature of 6580°C and warm air-steam mixture drying at the temperature of 105°C of pine and beech wood to the size of sawdust grains created by cutting using RPW 15M frame saw is presented in the paper. Particle size analysis of dry sawdust was performed using two methods - screening method and optical method based on...
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Electrical conductivity of nanostructured acceptor-doped ceria fabricated by spark plasma sintering (SPS)
PublikacjaHigh purity nanoscale powders (~10–15 nm size) of two different compositions of ceria, doped with Gd3+ and Ca2+, have been consolidated by spark plasma sintering (SPS) at different temperatures. Fully-dense samples were observed only at a sintering temperature of 980 °C. The as-sintered samples showed rather fast grain growth with an average grain size below 300 nm. The electrical properties of the samples were evaluated by impedance...
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Performance evaluation and model-based optimization of the mainstream deammonification in an integrated fixed-film activated sludge reactor
PublikacjaThis study aimed to model and optimize mainstream deammonification in an integrated fixed-film activated sludge (IFAS) pilot plant under natural seasonal temperature variations. The effect of gradually decreasing temperature on the performance was evaluated during a winter season and a transition period to summer conditions, and the correlation of the performance parameters was investigated using principal component analysis (PCA)....
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Influence of dopants on structure of polycrystalline bismuth niobate
PublikacjaBismuth niobate (BiNbO4) has attracted attention as a low-fired ceramics with promising microwave application potential. BiNbO4 ceramics was fabricated by mixed oxide method and sintered at temperature T<1000˚C. As the sintering aids a small amount of CuO oxide was used. The crystalline structure of the ceramic samples was examined by X-ray diffraction method at room temperature. The Rietveld refinement method was used for analysis...
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An inclination in Thermal Energy Using Nanoparticles with Casson Liquid Past an Expanding Porous Surface
PublikacjaPhysical aspects of inclined MHD nanofluid towards a stretching sheet embedded in a porous medium are visualized. Two types of nanoparticles are used named as copper and alumna dioxide with water as base fluid. Similarity transformations are used to convert the partial differential equations into the set of ordinary differential equation. Closed solutions are found to examine the velocity and the temperature profiles. It is examined...
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Increase of the effective energy from the radiant tube equipped with regenerative system in comparison with conventional recuperative system
PublikacjaPrzedstawiono wyniki badań eksperymentalnych spalania HiTAC (High Temperature Air Combustion) z użyciem rury promieniującej w celu porównania systemu palników regeneracyjnych z konwencjonalnym systemem rekuperacyjnym.
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Protection System Design of Induction Motor for Industries
PublikacjaThe fundamental and durable structures of induction motor, as well as their low manufacturing cost, make them popular components in a wide range of current applications. Providing a safety net for employees is a must-have for businesses. This project’s motivation for improvement is to provide industrial motors, lift motors, pumps, and so on with safety. An induction motor’s primary goal is to protect it from problems, such as...
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Protection System Design of Induction Motor for Industries
PublikacjaThe fundamental and durable structures of induction motor, as well as their low manufacturing cost, make them popular components in a wide range of current applications. Providing a safety net for employees is a must-have for businesses. This project’s motivation for improvement is to provide industrial motors, lift motors, pumps, and so on with safety. An induction motor’s primary goal is to protect it from problems, such as...
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Analysis of features of stainless steels in dissimilar welded joints in chloride inducted corrosion
PublikacjaStainless steels of femtic-austenitic microstructure that means the duplex Cr-Ni-Mo steels, in comparison with austenitic steel includes less expensive nickel and has much better mechanical properties with good formability and corrosion resistance, even in environments containing chloride ions. Similar share of high chromium ferrite and austenite, which is characterized by high ductility, determines that the duplex steels have...
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Towards Designing an Innovative Industrial Fan: Developing Regression and Neural Models Based on Remote Mass Measurements
PublikacjaThis article presents the process of the construction and testing a remote, fully autonomous system for measuring the operational parameters of fans. The measurement results obtained made it possible to create and verify mathematical models using linear regression and neural networks. The process was implemented as part of the first stage of an innovative project. The article presents detailed steps of constructing a system to...
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Crystal structure and low-energy Einstein mode in ErV2Al20 intermetallic cage compound
PublikacjaSingle crystals of a new ternary aluminide ErV2Al20 were grown using a self-flux method. The crystal structure was determined by powder X-ray diffraction measurements and Rietveld refinement, and physical properties were studied by means of electrical resistivity, magnetic susceptibility and specific heat measurements. These measurements reveal that ErV2Al20 is a Curie-Weiss paramagnet down to 1.95 K with an effective magnetic...