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Search results for: IR-THERMAL IMAGING
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Hyperbolic heat conduction at a microscopic sliding contact with account of adhesion-deformational heat generation and wear
PublicationDifferent non-Fourier models were proposed to simulate temperatures in materials subjected to extremely fast thermal disturbances, when the speed of heat propagation should be concerned. The present study investigated temperature and heat balance at a microscopic sliding contact during a single frictional interaction based on the Cattaneo-Vernotte hyperbolic heat conduction equation. Two fundamental features of friction, namely,...
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TiO2-C nanocomposite synthesized via facile surfactant-assisted method as a part of less energy-consuming LED-based photocatalytic system for environmental applications
PublicationA novel facile method was used to incorporate carbon into the titania structure. An alternative synthesis method of carbon-doped TiO2 has been proposed by using a widely used and cheap surfactant. During the process, cetyltrimethylammonium bromide plays a dual role, as a morphology modifier and as a carbon source. The presented approach allows obtained TiO2-C nanostructures to be anatase nanocrystals with carbon being deposited...
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Visualizing spatially decomposed intermolecular correlations in the infrared spectra of aprotic liquids
PublicationInfrared (IR) spectroscopy is commonly used to study intermolecular interactions in the liquid phase, including solvation phenomena. On the other hand, ab initio molecular dynamics (AIMD) simulations offer the possibility to obtain IR spectra from first principles. Surpassing the experiment, AIMD simulations can deliver additional information on the spatial intermolecular correlations underlying the IR spectrum of the liquid. Although...
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Obtaining and Characterization of the PLA/Chitosan Foams with Antimicrobial Properties Achieved by the Emulsification Combined with the Dissolution of Chitosan by CO2 Saturation
PublicationA new method of obtaining functional foam material has been proposed. The materials were created by mixing the poly lactic acid (PLA) solution in chloroform, chitosan (CS) dissolved in water saturated with CO2 and polyethylene glycol (PEG), and freeze-dried for removal of the solvents. The composite foams were characterized for their structural (SEM, FT-IR, density, porosity), thermal (DSC), functional (hardness, elasticity, swelling...
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Obtaining and Characterization of the PLA/Chitosan Foams with Antimicrobial Properties Achieved by the Emulsification Combined with the Dissolution of Chitosan by CO2 Saturation
PublicationA new method of obtaining functional foam material has been proposed. The materials were created by mixing the poly lactic acid (PLA) solution in chloroform, chitosan (CS) dissolved in water saturated with CO2 and polyethylene glycol (PEG), and freeze-dried for removal of the solvents. The composite foams were characterized for their structural (SEM, FT-IR, density, porosity), thermal (DSC), functional (hardness, elasticity, swelling...
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Influence of metallic porous microlayer on pressure drop and heat transfer of stainless steel plate heat exchanger
PublicationThe experimental analysis of passive heat transfer intensification in the case of plate heat exchanger has been carried out. The metallic porous layer was created on the heat transfer surface of analyzed unit. The experiment was accomplished in two stages. In the first stage the commercial stainless steel gasketed plate heat exchanger was investigated, while in the second one – the identical heat exchanger but with the modified...
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A Thermographic Measurement Approach to Assess Supercapacitor Electrical Performances
PublicationThis paper describes a proposal for the qualitative assessment of condition of supercapacitors based on the conducted thermographic measurements. The presented measurement stand was accompanied by the concept of methodology of performing tests. Necessary conditions, which were needed to minimize the influence of disturbing factors on the performance of thermal imaging measurements, were also indicated. Mentioned factors resulted...
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Super tough interpenetrating polymeric network of styrene butadiene rubber‐poly (methyl methacrylate) incorporated with general purpose carbon black ( N660 )
PublicationA classic set of polymeric interpenetrating polymeric network (IPN) microcomposites has been fabricated using an elastomer—styrene butadiene rubber [SBR], a thermoplastic poly(methyl methacrylate)-PMMA and with carbon black (CB)-N660 as a filler and reinforcing agent. This synthesized IPN composite can be promisingly employed as a toughened plastic and vibrational damper in a wide service range with excellent thermal stability,...
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Heat transfer characteristics of hybrid microjet – Microchannel cooling module
PublicationThe paper presents experimental investigation of heat transfer intensification in a microjet–microchannel cooling module. Applied technology takes benefits from two very attractive heat removal techniques. When jets are impinging on the surface, they have a very high kinetic energy at the stagnation point, also in microchannels boundary layer is very thin allowing to obtain very high heat fluxes. Main objective of this paper was...
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Comparison of heat transfer characteristics in surface cooling with boiling microjets of water, ethanol and HFE7100
PublicationThe basis of microjet technology is to produce jets which impinge the surface at the stagnation point with a very high kinetic energy. Main objective of this paper was to investigate the physical phenomena occurring on solid surfaces upon impingement of the single microjet in case of three fluids, namely water, ethanol and HFE7100. Intense heat transfer in the impact zone of microjet has been examined and described with precise...
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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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New procedure of silica gel surface modification-preparation of gaseous standard mixtures of methyl chloride using the technique of thermal decomposition of the surface compound for calibration of a TD-GC-FID system.
PublicationPrzedstawiono nową procedurę modyfikacji powierzchni żelu krzemionkowego w celu wytworzenia związku powierzchniowego będącego źródłem chlorku metylu. Minimalna temperatura rozkładu (150 st. C) zapewnia trwałość chemicznie modyfikowanego złoża w temp. pokojowej. Badania prowadzono w temperaturze optymalnej (280 st.C). Stwierdzono, że powierzchnia żelu jest obsadzona jednorodnie przez związek powierzchniowy i gazowa mieszanina wzorcowa...
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Towards sugar-derived polyamides as environmentally friendly materials
PublicationAs part of our ongoing study investigating isohexide-based polyamides, we have synthesized isosorbide(bis(propan-1-amine)) (DAPIS) and studied its reactivity in the polymerization towards fully biobased polyamides. Polycondensation of nylon salts with various contributions of DAPIS afforded a family of homo- and copolyamides, which were characterized using complementary spectroscopic techniques. The chemical structure of the materials...
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Empirical Relationship Describing Total Convective and Radiative Heat Loss in Buildings
PublicationOn the basis of theoretical considerations of convective-radiative heat transfer, a relationship was developed enabling the total convective and radiative heat flux QC+R emitted from any object at tw and its surroundings at t∞ to be calculated from known values of the surface temperature of such an object, i.e., the known temperature difference Δt=tw - t∞ and average air temperature Tav. This relationship is applied to thermal...
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Use of optical skin phantoms for preclinical evaluation of laser efficiency for skin lesion therapy
PublicationSkin lesions are commonly treated using laser heating. However, the introduction of new devices into clinical practice requires evaluation of their performance. This study presents the application of optical phantoms for assessment of a newly developed 975-nm pulsed diode laser system for dermatological purposes. Such phantoms closely mimic the absorption and scattering of real human skin (although not precisely in relation to...
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The influence of intermolecular correlations on the infrared spectrum of liquid dimethyl sulfoxide
PublicationDimethyl sulfoxide (DMSO) is routinely applied as an excellent, water-miscible solvent and chemical reagent. Some of the most important data concerning its liquid structure were obtained using infrared (IR) spectroscopy. However, the actual extent of intermolecular correlations that connect the isolated monomer spectrum to the IR response of the bulk liquid is poorly studied thus far. Using ab initio molecular dynamics (AIMD) simulations,...
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Measurement system for nonlinear surface spectroscopy by atomic force microscopy for corrosion processes monitoring
PublicationIn addition to traditional imaging the surface, atomic force microscopy (AFM) enables wide variety of additional measurements. One of them is higher harmonic imaging. In tapping mode the nonlinear contact between tip and specimen results in higher frequency vibrations. More information available from the higher harmonics analysis proves to be helpful for more detailed imaging. Such visualization is especially useful for heterogeneous...
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Imidazolium silanethiolates relevant to the active site of cysteineproteases. A cooperative effect in a chain of NH(+)...S(-) hydrogenbonds
PublicationThree imidazolium silanethiolates relevant to the active site of cysteine proteases have been synthesized and investigated by X-ray diffraction, IR spectroscopy and computational methods. As indicated by crystallographic and FT-IR data in the solid state, the transfer of proton from thiol to imidazole takes place and a thiolato-imidazolium ion pair is formed. The FT-IR spectra of crystalline imidazolium silanethiolates exhibit...
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A measurement system for nonlinear surface spectroscopy with an atomic force microscope during corrosion process monitoring
PublicationIn addition to traditional imaging the surface, atomic force microscopy (AFM) enables wide variety of additional measurements. One of them is higher harmonic imaging. In tapping mode the nonlinear contact between tip and specimen results in higher frequency vibrations. More information available from the higher harmonics analysis proves to be helpful for more detailed imaging. Such visualization is espe-cially useful for heterogeneous...
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Design and experimental investigations of a cylindrical microjet heat exchanger for waste heat recovery systems
PublicationCompact heat exchangers have more and more applications in many areas, including the HVAC, food and petrochemical industry. This paper describes the development of heat exchanger technology for waste heat recovery (WHR) from a range of processes. Case-study testing shows that the proposed heat exchanger can successfully enhance heat transfer and recover waste heat in a range of applications making them economically, environmentally and...
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Unusual Influence of Fluorinated Anions on the Stretching Vibrations of Liquid Water
PublicationInfrared (IR) spectroscopy is a commonly used and invaluable tool in the studies of solvation phenomena in aqueous solutions. Concurrently, ab initio molecular dynamics (AIMD) simulations deliver the solvation shell picture at a molecular detail level and allow for a consistent decomposition of the theoretical IR spectrum into underlying spatial correlations. Here, we demonstrate how the novel spectral decomposition techniques...
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Triplet energy exchange between fluorescent and phosphorescent organic molecules in a solid state matrix.
PublicationW pracy przedstawiono model wymiany energii trypletów na podstawie mechanizmu Dextera i zweryfikowano go w układzie dwuamina TPD : organiczny komleks Ir(ppy)3: matryca poliwęglanowa, mierząc czasy życia emisji Ir(ppy)3 przy różnych koncentracjach molekuł TPD.
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Communication: Inside the water wheel: Intrinsic differences between hydrated tetraphenylphosphonium and tetraphenylborate ions
PublicationTetraphenylphosphonium tetraphenylborate (TPTB) is a common reference electrolyte in physical chemistry of solutions allowing for a convenient partitioning of thermodynamic properties into single-ion contributions. Here, we compute on the basis of ab initio molecular dynamics simulations the infrared (IR) spectra for hydrated constituent ions of the TPTB assumption. Using spectral decomposition techniques, we extract important...
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Slowly-closing valve behaviour during steam machine accelerated start-up
PublicationThe paper discusses the state of stress in a slowly-closing valve during accelerated start-up of a steam turbine. The valve is one of the first components affected by high temperature gradients and is a key element on which the power, efficiency and safety of the steam system depend. The authors calibrated the valve model based on experimental data and then performed extended Thermal-FSI analyses relative to experiment. The issue...
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The influence of microjet array area ratio on heat transfer in the compact heat exchanger
PublicationThe paper describes the comprehensive study on the effect of microjet array geometrical parameters on the heat transfer enhancement in the modular heat exchanger. The conducted experimental study provides an experimental database on single phase submerged microjet heat transfer. The Wilson plot method was applied to determine the heat transfer coefficients in the laminar and transition flow regimes of a liquid-to-liquid heat exchanger....
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Development of a solventless stir bar sorptive extraction/thermal desorption large volume injection capillary gas chromatographic-mass spectrometric method for ultra-trace determination of pyrethroids pesticides in river and tap water samples
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Wwpływ temperatury suszenia osadów ściekowych na specjację metali ciężkich (Zn, Cu, Cd, Pb) = Influence of thermal drying temperature on heavy metal (Zn, Cu, Cd, Pb) speciation in sewage sludge
PublicationPrzedstawiono wpływ temperatury suszenia osadów ściekowych na zmiany specjacji metali ciężkich oraz określono stopień mobilności metali ciężkich w aspekcie ich późniejszego zagospodarowania. Ekstrakcja sekwencyjna metali ciężkich została wykonana wg schematu Tessier'a.
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The effect of dehydration/rehydration of bacterial nanocellulose on its tensile strength and physicochemical properties
PublicationBacterial nanocellulose (BNC) is a natural biomaterial with a wide range of biomedical applications. BNC contains 99 % of water which makes it too thick to be used as a bioimplant material. The aim of the work was to determine the effect of the BNC dehydration followed by rehydration on its mechanical and physicochemical properties, in the context of the use of BNC as bio-prostheses in the cardiovascular system. Dehydration involved the...
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Purification and biochemical characteristic of a cold-active recombinant esterase from Pseudoalteromonas sp. 643A under denaturing conditions.
PublicationIn this paper production of a cold-active esterase EstA from the Antarctic bacterium Pseudoalteromonas sp. 643A in E. coli expression system was described. The purification and biochemical characteristic of EstA were performed in the presence of urea and then compared with results obtained for the esterase with no addition of urea and isolated from the native source. In both cases the cold-active enzyme displayed similar properties....
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Mono- and polynuclear Co(II) silanethiolates with aliphatic diamines
PublicationFour Co(II) complexes, [Co{SSi(OtBu)3}2(dmpda)] 1, [Co{SSi(OtBu)3}2(bda)2]n2 [Co{SSi(OtBu)3}2(pda)2]n3 and [Co{SSi(OtBu)3}2(hda)2]n4 [dmpda = 3-(dimethylamino)-1-propylamine; bda = 1.4-butanediamine; pda = 1.5-pentanediamine; had = 1.6-hexanediamine] have been synthesized and characterized using X-ray diffraction. Complex 1 is mononuclear and contains Co(II) coordinated by dmpda molecule in chelating mode, whereas compounds 3 and...
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Biosilica from sea water diatoms algae—electrochemical impedance spectroscopy study
PublicationHere, we report on an electrochemical impedance study of silica of organic origin as an active electrode material. The electrode material obtained from carbonized marine biomass containing nanoporous diatoms has been characterised by means of XRD, IR, SEM and EIS. Dif- ferent kinds of crystallographic phases of silica as a result of thermal treatment have been found. The electrode is electrochemically stable during subsequent cyclic...
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Molecularly targeted nanoparticles: an emerging tool for evaluation of expression of the receptor for advanced glycation end products in a murine model of peripheral artery disease
PublicationAbstract Background: Molecular imaging with molecularly targeted probes is a powerful tool for studying the spatio-temporal interactions between complex biological processes. The pivotal role of the receptor for advanced glycation end products (RAGE) in numerous pathological processes, aroused the demand for RAGE targeted imaging in various diseases. In the study, we evaluated the use of a diagnostic imaging agent for RAGE quantification...
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Use of optical skin phantoms for calibration of dermatological lasers
PublicationA wide range of dermatological diseases can be efficiently treated using laser heating. Nevertheless, before the new laser is introduced into clinical practice, its parameters and ability to interact with human skin have to be carefully examined. In order to do that optical skin phantoms can be used. Such phantoms closely imitate the scattering and absorption properties of real human skin tissue along with its thermal properties,...
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Synthesis, structure and properties of poly(ether-urethane)s synthesized using a tri-functional oxypropylated glycerol as a polyol
PublicationThe main aim of this work was to obtain poly(ether-urethane)s using tri-functional polyoxyalkylene polyol (Rokopol G1000), which introducing the chemical cross-links into the structure of polyurethanes. Poly(ether-urethane)s were prepared using two-step method, called prepolymer method, which involves in the first step the reaction of 4,4'-diphenylmethane diisocyanate (MDI) and tri-functional polypropylene glycol glycerol triether...
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Heat exchange enhancement of jet impingement cooling with the novel humped-cone heat sink
PublicationJet impingement cooling technology is applicable to control temperature of devices, where very high heat flux is generated within a small area. This paper is about the improvement of the jet impingement cooling efficiency by the heat sink geometry modification. Two reference cases were sourced from the literature – flat heat sink and modified one with cone in the jet stagnation region. Such a change improves cooling capability...
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Synthesis and structural properties of (Y, Sr)(Ti, Fe, Nb)O3−δ perovskite nanoparticles fabricated by modified polymer precursor method
PublicationThe yttrium, iron and niobium doped-SrTiO3 powders have been successfully fabricated by a modified low–temperature synthesis method from a polymer complex. The usage of strontium hydroxide precursor instead of conventional strontium nitrate or strontium carbonate provides to the possibility of significant decrease of annealing temperature. It allows to prepare a material with sphere-shape grains of nanometric size (15–70 nm). The...
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DMSO and TMAO—Differences in Interactions in Aqueous Solutions of the K-Peptide
PublicationInteractions between a solvent and their co-solute molecules in solutions of peptides are crucial for their stability and structure. The K-peptide is a synthetic fragment of a larger hen egg white lysozyme protein that is believed to be able to aggregate into amyloid structures. In this study, a complex experimental and theoretical approach is applied to study systems comprising the peptide, water, and two co-solutes: trimethylamide...
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Experimental investigations on adiabatic frictional pressure drops of R134a during flow in 5mm diameter channel
PublicationThe article presents detailed two-phase adiabatic pressure drops data for refrigerant R134a at a saturation pressure of 5.5 bar corresponding to the saturation temperature of 19.4 °C. Study cases have been set for a mass flux varying from 100 to 500 kg/m2 s. The frictional pressure drop was characterized for the refrigerant R134a, for vapor qualities ranging from 0 to 1. Long-time thermal stability of test facility allowed to gather...
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A new technique with high reproducibility to estimate renal oxygenation using BOLD-MRI in chronic kidney disease
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NMR relaxation enhancement in gels polymerized and cross-linked by ionizing radiation: A new approach to 3D dosimetry by MRI
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Improving depth maps of plants by using a set of five cameras
PublicationObtaining high-quality depth maps and disparity maps with the use of a stereo camera is a challenging task for some kinds of objects. The quality of these maps can be improved by taking advantage of a larger number of cameras. The research on the usage of a set of five cameras to obtain disparity maps is presented. The set consists of a central camera and four side cameras. An algorithm for making disparity maps called multiple...
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Optimization of the System for Determining the Volume of Tissue Needed for Breast Reconstruction
PublicationThis article presents techniques for reconstructing surfaces and volume calculations using a point cloud generated from 3D imaging. The main objective of this article was to optimize the voxel size for the most accurate representation of the surface of the female breast. We experimented with different methods for determining volume using images from the Intel D435i camera. In addition, we designed application and measurement station...
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3D-Breast System for Determining the Volume of Tissue Needed for Breast Reconstruction
Publication3D imaging systems can be used to effectively determine breast volumes for surgical applications. This article presents methods for surface reconstruction and volume determination based on the point cloud created by 3D imaging. Such a system would be used to accurately estimate breast volume in patients classified for breast reconstruction surgery at plastic surgery centers. To develop such a system, various methods of determining...
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Computational analysis of power-law fluids for convective heat transfer in permeable enclosures using Darcy effects
PublicationNatural convection is a complex environmental phenomenon that typically occurs in engineering settings in porous structures. Shear thinning or shear thickening fuids are characteristics of power-law fuids, which are non-Newtonian in nature and fnd wide-ranging uses in various industrial processes. Non-Newtonian fuid fow in porous media is a difcult problem with important consequences for energy systems and heat transfer. In this...
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Digital measurement of frequency with linear interpolation in dynamic states
PublicationPrzedstawiono metody rejestracji częstotliwości sygnałów impulsowych. Zastosowanie interpolacji pozwala na uzyskanie wyniku dla dowolnej chwili. Opisano pracę w trybie on-line i off-line.
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Protection Against Electric Shock Using Residual Current Devices in Circuits with Electronic Equipment
PublicationW artykule przedstawiono problematykę stosowania wyłączników różnicowoprądowych w obwodach z urządzeniami elektronicznymi, które powodują, że prąd różnicowy ma zmienną częstotliwość lub jest odkształcony. Wyniki badań wskazują, że częstotliwość obiegająca od znamionowej oraz zawartość wyższych harmonicznych w prądzie różnicowym niekorzystnie wpływa na skuteczność ochrony przeciwporażeniowej przy zastosowaniu wyłączników różnicowoprądowych....
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Comparison of residual current devices tripping characteristics for selected residual current waveforms
PublicationZgodnie z normami międzynarodowymi, w instalacjach o zwiększonym ryzyku porażenia prądem elektrycznym należy stosować wyłączniki różnicowoprądowe wysokoczułe. Dla zapewnienia skutecznej ochrony przeciwporażeniowej zainstalowany wyłącznik różnicowoprądowy powinien prawidłowo wykrywać określony kształt prądu różnicowego. W artykule przedstawiono charakterystyki działania wyłączników różnicowoprądowych przy wybranych przebiegach odkształconego...
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Indirect Measurement of Motor Current Derivatives in PMSM Sensorless Drives
PublicationMotor current derivatives contain useful information for control algorithms, especially in sensorless electric drives. The measurement of motor current derivatives in electric motors supplied by voltage source inverter can be performed using di/dt transducers. However, in such a solution additional sensors have to be installed, e.g. Rogowski coils. Another approach is to measure current derivatives indirectly – by oversampling...
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Subjective and Objective Quality Evaluation Study of BPL -PLC Wired Medium
PublicationThis paper presents results of research on the effectiveness of bi-directional voice transmission in a 6 kV mine cable network using BPL-PLC (Broadband over Power Line - Power Line Communication) technology. It concerns both emergency cable state (supply outage with cable shorted at both ends) and loaded with distorted current waveforms. The narrowband (0.5 MHz–15 MHz) and broadband (two different modes, frequency range of 3 MHz–7.5...
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Automatic sound source localization in disturbing conditions using acoustic vector sensors
PublicationA concept, practical realization and applications of a passive acoustic radar to automatic localization and tracking of sound sources in disturbing conditions were presented in the paper. The device consists of the new kind of multichannel miniature sound intensity sensors and a group of digital signal processing algorithms. The sensitivity of the realized acoustic radar was examined in free sound field. Several kinds of sound...