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Search results for: inlet air fogging
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The process generation of WWTP models for optimization of activated sludge systems
PublicationThe objective of water and wastewater utilities, which are responsible for optimization of wastewater treatment plant operation, is threefold: environmental protection, saving money, and mitigation of pollutant emissions, both to water and air. The performed study aimed to assess the process generation of WWTP models that improve activated sludge systems operation, by means of new developed Mantis2 model. This model accounts for...
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Spectral reflectance and transmission modeling of multi-cavity Fabry-Pérot interferometer with ZnO thin films
PublicationIn this paper spectral reflectance and transmission of a low-coherence fiber-optic Fabry-Pérot interferometer with thin ZnO layers is analyzed using a multi-cavity approach. In the investigated setup two standard single-mode optical fibers (SMF-28) with thin ZnO films deposited on their end-faces form an extrinsic Fabry-Pérot interferometer with air cavity. Calculations of the spectral response of the interferometer were performed...
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The low coherence Fabry-Pérot interferometer with diamond and ZnO layers
PublicationThe authors present a fiber-optic Fabry-Pérot interferometer built with the application of diamond and zinc oxide (ZnO) thin layers. Thin ZnO films were deposited on the tip of a standard telecommunication single-mode optical fiber (SMF- 28) while the diamond layer was grown on the plate of silicon substrate. Investigated ZnO layers were fabricated by atomic layer deposition (ALD) and the diamond films were deposited using Microwave...
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Signals features extraction in radioisotope liquid-gas flow measurements using wavelet analysis
PublicationKnowledge of the structure of a flow is significant for the proper conduct of a number of industrial processes. In this case, a description of a two-phase flow regimes is possible by use of the time-series analysis in time, frequency and state-space domain. In this article the Discrete Wavelet Transform (DWT) is applied for analysis of signals obtained for water-air flow using gamma ray absorption. The presented method was illustrated...
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Enhancement of fiber-optic low-coherence Fabry-Pérot interferometer with ZnO ALD films
PublicationIn this paper investigation of the enhanced fiber-optic low coherence Fabry-Pérot interferometer with zinc oxide (ZnO) film deposited by atomic layer deposition (ALD) was presented. Model of the interferometer, which was constructed of single-mode optical fiber with applied ZnO ALD films, was built. The interferometer was also examined by means of experiment. Measurements were performed for both reflective and transmission modes,...
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Conversion of Biomass and Municipal Wastes into Syngas and Hydrogen using Highly Preheated Agent (HTAG)
PublicationGasification is considered to be one of the most promising energy recovery technologies for the widespread utilization of biomass and wastes. During this process raw feedstock is converted into a combustible gas, which can then be burnt to produce thermal energy, or to run engines for mechanical or electrical power. The studies of biomass gasification demonstrate it as a friendly alternative to fossil fuels as one of renewable...
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Influence of High Temperature Oxidation on Hydrogen Absorption and Degradation of Zircaloy-2 and Zr 700 Alloys
PublicationThe present research was aimed at determining the effects of the oxide layers on hydrogen absorption, microstructure and mechanical properties of the Zircaloy- 2 and Zr 702 alloys. The oxidation was made at 350 °C, 700 °C and 900 °C for 10 to 30 min in laboratory air, followed by hydrogen cathodic charging for 72 h and annealing at 400 °C for 4 h. The slow strain rate tests were carried out on oxidized, charged and annealed specimens. The...
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Experimental investigation on straight and u-bend double tube heat exchanger with active and passive enhancement methods
PublicationAuthors in this work want to demonstrate the possibility to increase the heat transfer efficiency by using simple wire coil inserts to create turbulent flow in the boundary layer as well as air blowing into the annulus of the pipe. In the study, Wilson plot approach was applied in order to estimate heat transfer coefficients for all heat exchanger (HX) configurations. The study focuses on experimental values of heat transfer coefficient...
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Application of additional factors supporting the microextraction process
PublicationDue to the fact that green analytical chemistry is of high importance, the past two decades have witnessed a rapid growth in the sample preparation area with special emphasis on simplification, miniaturization and automation of extraction procedures. In addition, to accelerate the extraction processes and to improve the separation of analytes, several enhanced parameters are applied. These factors include, ultrasounds, microwaves,...
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Równoważność metod pomiarowych ciągłych i odniesienia stosowanych do oznaczania pm10
PublicationW pracy przedstawiono wyniki testu terenowego przeprowadzonego na terenie Gdańska w okresie od 01-01-2010 do 31-12-2010 i od 01-01-2011 do 31-12-2011 w celu wykazania równoważności wskazań analizatora Eberline FH 62-1 w stosunku do wagowej metody odniesienia. Przedyskutowano występowanie różnic wskazań wartości stężeń pyłu PM10 w zależności od pory roku dla obu metod pomiarowych. Przedstawiono sposób określania równoważności tych...
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The effect of 1,4-butanediol on the efficiency of CO2 absorption and inhibition of NH3 escape during the mineral carbonation of gypsum
PublicationThis study explored the optimal concentration of 1,4-butanediol for maximizing CO2 absorption and minimizing ammonia desorption. Mineral carbonation of gypsum slurry was carried out in a bubble reactor with a magnetic stirrer maintaining constant speed for 1 hour. The gas introduced to the reactor was a mixture of CO2 and air. The gas flow was controlled by the mass controllers. Gas sensors were used to determine the concentration...
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Influence of cyclic frozen and defrost on mechanical properties of polytetrafluoroethylene (PTFE)-coated woven fabrics
PublicationThis research aims to determine the influence of the cyclic process of freezing and defrosting on the mechanical properties of the chosen glass fibres and PTFE-coated woven fabrics. The specimens were subjected to freezing at about −20 °C for 4 h and thawing by full immersion into the water at about +20 °C for 4 h. The fabric samples after 25 and 50 frozen cycles were air-dried at room temperature for one week and then subjected...
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Odour Perception Using a Sniffing Team at a Municipal Solid Waste Treatment Plant: A Case Study
PublicationThe monitoring of odour intensity, generated by a landfill area, is a difficult activity since it is a multi-source problem with discontinuous odour emissions. A modified sniffing team method is described here and applied to determine the main odour sources in a landfill located in Pomerania, Poland. Four consecutive test sessions were performed during the following months: August, December, April, and June. It was found that the...
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Temperature Sensors Based on Polymer Fiber Optic Interferometer
PublicationTemperature measurements are of great importance in many fields of human activities, including industry, technology, and science. For example, obtaining a certain temperature value or a sudden change in it can be the primary control marker of a chemical process. Fiber optic sensors have remarkable properties giving a broad range of applications. They enable continuous real-time temperature control in difficult-to-reach areas, in...
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O problemie kolmatacji geowłóknin stosowanych w drenażach
PublicationSystemy drenażowe występujące przy obiektach drogowych są niezwykle istotnym elementem tych budowli. Jednym z materiałów, które obecnie powszechnie stosowane są w systemach drenażowych są geowłókniny. Ich zadaniem jest zabezpieczenie odwadnianego gruntu przed procesem sufozji, jak również ochrona drenażu przed zamuleniem przy jednoczesnym zachowaniu wodoprzepuszczalności. Typową trwałość drenażu, w zależności od rozwiązań, szacować...
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A study of a compact high-efficiency zero-emission power plant with oxy-fuel combustion
PublicationThis paper discusses the application of global trends in gas cycles technology using oxy-fuel combustion. This is followed by a demonstration of a design solution for a new cycle with two enhanced energy-converting devices, namely a wet combustion chamber and a spray-ejector condenser. The proposed gas and steam cycle unit is contained within a single turbine, whose benefits combine those offered by gas turbines (high inlet temperatures)...
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A new construction of shell-and-tube heat exchanger with impinging jets and minichannels technologies for heat recovery from gases – experimental analysis
PublicationA dynamic development of technologies allowing waste heat utilization is observed in a correspondence with a pro-ecological approach of the zero waste idea. Such approach becomes the most demanding in the area of low-temperature was heat sources, especially gaseous media. Till now, they were usually not utilized due to unfavorable thermal conditions and high costs. Therefore, the zero waste approach directs research on techniques...
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Technical and Economic Analysis of the Supercritical Combined Gas-Steam Cycle
PublicationCombined cycle power plants are characterized by high efficiency, now exceeding 60%. The record-breaking power plant listed in the Guinness Book of World Records is the Nishi-Nagoya power plant commissioned in March 2018, located in Japan, and reaching the gross efficiency of 63.08%. Research and development centers, energy companies, and scientific institutions are taking various actions to increase this efficiency. Both the gas...
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Experimental investigations on heat transfer enhancement in shell coil heat exchanger with VARIABLE Baffles GEOMETRY
PublicationThe paper presents the possibility of using passive intensification of heat transfer in the form of baffles to increase the energy efficiency of the shell and coil heat exchanger. The experiment was carried out by using a modular coil heat exchanger in the form of an electric heater. Water was used as a working fluid with constant thermal-flow parameters at the inlet of the module. It should be noted that experiments were made...
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Dynamics of fault arc traveling along busbars in high voltage switchboards = Dynamika łuku zwarciowego przemieszczającego się wzdłuż szyn rozdziel-nic wysokiego napięcia
PublicationThe paper presents the results of magnetic induction and electrodynamic force calculations acting on arc column during short-circuit in medium voltage air-insulated bus-bars. The gap between the bars was 120 mm and the prospective short-circuit currents ranged from 4 kA to 8 kA. The paper also shows the measurement results of average velocity fault arc depending on currents arc diameter and arc current was established and described....
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Wpływ emisji Lotnych Związków Organicznych (LZO), na jakość powietrza w pomieszczeniach wnętrz
PublicationNa jakość powietrza w pomieszczeniach wnętrz (ang. Indoor Air Quality, IAQ) mają wpływ zarówno czynniki fizyczne (np. hałas, temperatura, wilgotność powietrza) jak i czynniki chemiczne (m.in. Lotne Związki Organiczne, LZO) oraz biologiczne (np. mikroorganizmy). W przypadku czynników chemicznych, istotną grupę związków stanowią głównie LZO (np. węglowodory aromatyczne, alifatyczne). Ponad połowa emisji tych związków pochodzi z materiałów...
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Sensorless Control of Polyphase Induction Machines
PublicationThe basics of transformations of polyphase systems into orthogonal systems are explained. Vector models of induction machines in orthogonal planes are analysed and multiscalar models for rotor flux and main flux together with stator current are presented. A speed observer based on an extended model of the induction machine for selected variables is applied in the control system for the induction machine. On the basis of the model...
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Properties of Thermally Dewetted Thin Au Films on ITO-Coated Glass for Biosensing Applications
PublicationNoble metal nanostructures are object of great interest due to their unique optical and electronic properties exploited in nanotechnology, medicine, biochemistry, and surface-enhanced spectroscopies. In this work, the Au nanoparticle (NP) structures for application in biosensing obtained by dewetting are investigated in dependence on their preparation conditions. Structures are produced from thin Au films (5–30 nm) sputtered onto...
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Sposoby zagospodarowania ciepła odpadowego z silników napędowych jednostek pływających Cześć 1. Wykorzystanie ciepła do napędu urządzeń chłodniczych
PublicationEnergia chemiczna paliwa jest w wielu przypadkach zaledwie w połowie wykorzystana jako energia napędowa silnika. Pozostała część jako ciepło odpadowe przekazywana jest do otoczenia. Dzięki odpowiednim układom przetwarzania ciepło ze spalin można wykorzystać do wytwarzania chłodu lub jako ciepło użytkowe, w systemach HVAC (ang. heating, ventilation, air conditioning – ogrzewanie, wentylacja, klimatyzacja). Tym samym koszty pracy...
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High-temperature properties of titanium-substituted yttrium niobate
Publicationhe defect fluorite titanium-doped yttrium niobate samples Y3Nb1−xTixO7−δ have been synthesized and investigated by the means of high-temperature X-ray diffraction, dilatometry, and thermogravimetry. Thermal expansion coefficients (TECs) as well as chemical expansion coefficients for material with 5, 10, and 15 mol% of titanium were determined. All investigated samples exhibit chemical contraction caused by Ti doping. The values...
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Nanoindentation tests titanium alloy Ti-6Al-4V after interference laser treatment
PublicationThe study aimed was to assess selected mechanical properties of surface layers obtained after interference laser treatment – DLIL of titanium alloy Ti-6Al-4V used for implants. The samples were melted in still air at room temperature, for this purpose Nd:YAG laser was used, the number of laser shots was variable. Next, nanoindentation tests were performed, based on which Young’s modulus and nanohardness in the obtained surface...
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Influence of Gd deposition on the oxidation behavior and electrical properties of a layered system consisting of Crofer 22 APU and MnCo2O4 spinel
PublicationIn the study, the surface of the Crofer 22APU ferritic steel was modified with gadolinium oxide nanoparticles and a protective-conducting layer consisting of the MnCo2O4 spinel. This system was studied in the context of application in IT-SOFC interconnects. Four types of samples were studied: unmodified steel, steel coated with a manganese-cobalt spinel layer, steel modified with gadolinium oxide nanoparticles, and a system consisting...
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Influence of Holes Manufacture Technology on Perforated Plate Aerodynamics
PublicationTranspiration flow is a very important and still open subject in many technical applications. Perforated walls are useful for the purpose of “flow control”, as well as for the cooling of walls and blades (effusive cooling) in gas turbines. We are still not able to include large numbers of holes in the numerical calculations and therefore we need physical models. Problems are related also to the quality of the holes in perforated...
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A state of the art review on the use of fungi in biofiltration to remove volatile hydrophobic pollutants
PublicationThe physical/chemical abatement of gas pollutants creates many technical problems, is costly and entails significant environmental impacts. Biological purification of off-gases is a cheap and ecologically safe way of neutralization of gas pollutants. Despite the recent advances, the main technological challenge nowadays is the purification of volatile organic compounds (VOCs) of hydrophobic character due to their low solubility...
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A Comparative Study on Methods of Distinction Between Near- and Far-Side Defects as Techniques Used Alongside with the Magnetic Flux Leakage Testing
PublicationResults of the finite element analysis show that a far-side defect in a steel plate, with the depth greater by 10% of the plate thickness than a near-side defect, can produce a very similar magnetic flux leakage (MFL) signal. Due to the fact that a measurement of MFL itself can lead to misclassification of a far-side defect as a near-side one, and thus to underestimation of its depth, a comparative study of three complementary...
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Hydraulic resistance analyses of selected elements of the prototype Stirling engine
PublicationThe paper presents the results of simulation tests of hydraulic resistance and temperature distribution of the prototype Stirling alpha engine supplied with waste heat. The following elements were analyzed: heater, regenerator and cooler. The engine uses compressed air as a working gas. Analyses were carried out for three working pressure values and different engine speeds. The work was carried out in order to optimize the configuration...
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Numerical investigations of discrete crack propagation in Montevideo splitting test using cohesive elements and real concrete micro-structure
PublicationThe paper is aimed at accurately predicting the discrete fracture process in concrete specimens under complex stress states in two dimensional (2D) simulations. Plain concrete specimens subjected to Montevideo splitting test (MVD) were used for consideration due to non-negligible shear stresses impact in this type of test. In order to reflect the heterogeneous nature of the concrete, the meso-structure of the samples was included...
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Microfluidic SIW-Based Tunable Self-Diplexing Antenna for Sub-6 GHz Band Applications
PublicationThis work introduces a novel frequency tunable self-diplexing antenna (SDA) design based on substrate integrated waveguide (SIW) technology. A modified A-shaped slot is employed on the cavity’s top plane, which is excited by two independent 50 Ω microstrip feed lines to operate at each resonant frequency. The frequency flexibility of the proposed antenna allows for fine-tuning at each resonance frequency. The frequency flexibility...
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Assessment of under power ed propulsion machinery in electrically driven small inland waterway passenger ships from classification society point of view
PublicationPaper presents short operat ional a nd engineering analysis of underpowered propulsion in small electrically propelled small inland passenger ships. There is evidence that in certain weather conditions the phenomena of added aerodynamic resistance of small water crafts may have seriou s influence on their speed and manoeuvrability. Existing regulations like class societies rules for ship classification and construction or EU Directive 2006/87/EC do...
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Study of Cloud Water Samples Collected over Northern Poland
PublicationThe paper gives the results of the first studies on the chemistry of cloud water collected during 3 mo (Aug.–Oct. 2010) in the free atmosphere over the area to the south of the Tri-City (Gdansk-Sopot-Gdynia) conurbation on the Gulf of Gdansk, Poland. Taken from cumulus, stratus, and stratocumulus clouds by means of an aircraft-mounted collector, the water samples were analyzed for the following contaminants: anions (chlorides,...
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ASSESSMENT OF UNDERPOWER ED PROPULSION MACHINERY IN ELECTRICALLY DRIVEN SMALL INLAND WATERWAY PASSENGER SHIPS FROM CLASSIFICATION SOCIETY POINT OF View
PublicationPaper presents short operat ional a nd engineering analysis of underpowered propulsion in small electrically propelled small inland passenger ships. There is evidence that in certain weather conditions the phenomena of added aerodynamic resistance of small water crafts may have serious influence on their speed and manoeuvrability. Existing regulations like class societies rules for ship classification and construction or EU Directive 2006/87/EC do...
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Methodology for determination of the selected mechanical properties of wood based on cutting tests
PublicationFrom kiln-dried spruce wood (with steam) as well as in natural conditions were randomly selected 8 samples. After determining the average dimensions, moisture content and density of the samples they have been cut on the frame sawing machine PRW15M for measurement of cutting power. Based on those results from a linear rela-tionship of cutting power versus feed per toot mechanical properties of wood such as facture toughness and...
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Investigation of Narrow Electrostatic Precipitator with Wire Multi-Electrode
PublicationDiesel engines emit fine particles, which are harmful to human and animal health. There are several methods for decrease particulate emission from a diesel engines, but up to now, these methods are notenough effective or very expensive. An electrostatic precipitation was proposed as an alternative method for control of a diesel particulate emission. Therefore, narrow electrostatic precipitators (ESPs) have become a subject of interest...
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Electrochemical Activity and Electrical Properties of Optimized Polypyrrole Coatings on Iron
PublicationIn this work, electrochemical activity and electrical properties of polypyrrole (PPy) coated iron electrodes have been investigated. PPy film was electrochemically polymerized from sodium salicylate aqueous solution under conditions, which provided an increase of iron corrosion resistance. It was noticed that the pH of the solution and the applied electrode potential range during the study of the polymer properties had an influence...
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EFFICIENCY OF GAS MIXTURES DETECTION BY RESISTIVE GAS SENSORS
PublicationResistive gas sensors are very popular and are commonly used to detect various gases and their mixtures. Their main disadvantage is very limited selectivity. Practical use of gas sensors in environmental applications (e.g., in sewage systems to protect workers, in air conditioning systems to monitor atmosphere quality) requires determination of concentration of a few mixed gases at the same time. We would like to present recent...
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Coplanar Waveguide-Fed Broadband Microwave Devices with (or without) a Thin Dielectric Substrate for Use in Flexible Electronic Systems
PublicationTwo examples of microwave devices, fed by a coplanar waveguide and realized on a thin substrate (or without such a substrate), are employed to investigate the influence of devices’ curvatures and the proximity of different materials on their parameters. To perform the tests, a broadband antenna and a low-pass filter are chosen. A feeding coplanar waveguide is realized on a dielectric material brick attached to an SMA connector...
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Two-Level Multivariable Control System of Dissolved Oxygen Tracking and Aeration System for Activated Sludge Processes
PublicationThe problem of tracking dissolved oxygen is one of the most complex and fundamental issues related to biological processes. The dissolved oxygen level in aerobic tanks has significant influence on behaviour and activity of microorganism inhabiting the plant. Aerated tanks are supplied with air from an aeration system (blowers, pipes, throttling valves, diffusers). It is a complex dynamic system governed by nonlinear hybrid dynamics....
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Effect of underwater wet welding conditions on the diffusible hydrogen content in deposited metal
PublicationIn the study mercury displacement method was used for determination of diffusible hydrogen amount in deposited metal obtained during underwater wet welding with covered electrodes in laboratory conditions according to a two-level full factorial design for three factors. The factors and their levels were chosen among conditions and parameters of welding in accordance with the results of own preliminary studies. A statistical analysis...
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Supervisory Control System for Adaptive Phase and Work Cycle Management of Sequencing Wastewater Treatment Plant
PublicationThe paper presents the design of the integrated control system applied to Sequencing Batch Reactor (SBR) in a biological Wastewater Treatment Plant (WWTP) in Swarzewo, which operates under activated sludge technology. Based on the real data records, ASM2d biological processes model and aeration system model, hierarchical control system for dissolved oxygen tracking and cycle management is designed. Internal Model Controller (IMC)...
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Application of Thin ZnO ALD Layers in Fiber-Optic Fabry-Pérot Sensing Interferometers
PublicationIn this paper we investigated the response of a fiber-optic Fabry-Pérot sensing interferometer with thin ZnO layers deposited on the end faces of the optical fibers forming the cavity. Standard telecommunication single-mode optical fiber (SMF-28) segments were used with the thin ZnO layers deposited by Atomic Layer Deposition (ALD). Measurements were performed with the interferometer illuminated by two broadband sources operating...
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Sensorless control of five-phase induction machine supplied by the VSI with output filter
PublicationIn this paper, a novel sensorless control structure based on multi-scalar variables is proposed. The tatic feedback control law is obtained by using the multi-scalar variables transformation, where the multi-scalar variables approach allows a full linearization of the nonlinear system. The control system could be described as “optimized” because of the minimized number of controllers. Furthermore, control system is divided into...
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The influence of the welding environment on the properties of Tekken joints made from S355J2C+N steel
PublicationThere are three main methods of underwater welding: dry, wet and intermediate between them, by using the local dry chamber. Due to low costs, the most common method is the wet welding with the use of covered electrodes. Water as a welding environment carries out a lot of problems. The first is limited visibility and instability of the welding arc. The biggest problem during underwater welding is high susceptibility to cold cracking,...
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Performance of microbial fuel cells operated under anoxic conditions
PublicationNowadays, microbial fuel cells (MFC) stand up as a promising renewable energy source. Due to the ability of the MFC to oxidize a wide spectrum of substrates, wastewater seems to be one of the most interesting fuels. Unfortunately, wastewater could contain electron acceptors such as nitrate, which could interfere with the electrical performance of the MFC. In this work, the influence of oxidised nitrogen forms on the electricity...
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UAV Design and Construction for Real Time Photogrammetry and Visual Navigation
PublicationA unmanned aerial vehicles applications in photogrammetry have increased rapidly last years. A fast data gathering and processing in real time in some cases become crucial and desired in some application. In the paper, a real time solution is proposed. A real time photogrammetry from UAV is proposed, where image data are gathered and processed on board UAV and finally reconstructed 3D model and measurements are delivered. The paper...
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Evaluation of Three Peptide Immobilization Techniques on a QCM Surface Related to Acetaldehyde Responses in the Gas Phase
PublicationThe quartz-crystal microbalance is a sensitive and universal tool for measuring concentrations of various gases in the air. Biochemical functionalization of the QCM electrode allows a label-free detection of specific molecular interactions with high sensitivity and specificity. In addition, it enables a real-time determination of its kinetic rates and affinity constants. This makes QCM a versatile bioanalytical screening tool for...