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Search results for: THERMODYNAMIC WORKING FLUIDS
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Parametric Study on a Performance of a Small Counter-Rotating Wind Turbine
PublicationA small Counter-Rotating Wind Turbine (CRWT) has been proposed and its performancehas been investigated numerically. Results of a parametric study have been presented in this paper.As parameters, the axial distance between rotors and a tip speed ratio of each rotor have been selected.Performance parameters have been compared with reference to a Single Rotor Wind Turbine (SRWT).Simulations were carried out with Computational Fluids...
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Reliability and Validity of Optoelectronic Method for Biophotonical Measurements
PublicationReliability and validity of measurements is of utmost importance when assessing measuring capability of instruments developed for research. In order to perform an experiment which is legitimate, used instruments must be both reliable and valid. Reliability estimates the degree of precision of measurement, the extent to which a measurement is internally consistent. Validity is the usefulness of an instrument to perform accurate...
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A mathematical model of rheological behavior of novel bio-based isocyanate-terminated polyurethane prepolymers
PublicationIn this paper, the results of rheological study on isocyanate-terminated polyurethane prepolymers, containing modified soybean oil residues incorporated into the chemical structure are described. Isocyanate-terminated prepolymers were synthesized from 4,4′-diphenylmethane diisocyanate and the mixture of hydroxylated soybean oil and commercial polyether. The measurements were performed by using rotary rheometer R/S-CPS+ (Brookfield,...
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The new concept of capillary forces aided evaporator for application in domestic organic rankine cycle
PublicationThis paper presents studies on the possibility of applying capillary forces induced in the porous structure to a modern design of evaporator. The potential application of such heat exchanger is for example an evaporator of the domestic micro combined heat and power (CHP) unit. One of the problems in the micro-CHP is excessive demand for pumping power. The proposed design helps in overcoming that issue. In the evaporator outlined...
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Nitrogen dioxide sensing properties of PEDOT polymer films
PublicationThis work presents a simple and fully electrochemical route for the polymerization of poly(3,4-ethylenedioxytiophene) (PEDOT) films for fabricating a NO2 gas sensor prepared by electropolymerization of 3,4-Ethylenedioxythiophene (EDOT) monomer in lithium perchlorate/acetonitrile solution. The main aim of this study is to determine the sensing properties of conductive polymer at elevated temperatures. The effects of the humidity,...
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Scalable Measurement System for Multiple Impedance Gas Sensors
PublicationAuthor proposes scalable architecture of the measurement system for gas sensor with impedance dependance of the gas concentration. The main part of the system is a single-board impedance analyser. The number of analysers working in parallel can be configured according to specific application. The system is controlled by a single computer which organises the measurement cycle and store the acquired measurement data. The system is...
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Test loading of the longest span arch bridge in Poland
PublicationBridge structures undergo thorough examination during test loading before they come into use. The aim of the examination is to check the correctness of the working structure and construction design assumptions. Test loading on the bridge is preceded by examination specification. This paper describes computational model and test loading results carried out during examibation of the bridge over the Vistula within the bypass of Puławy...
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Routing decisions independent of queuing delays in broadband leo networks
PublicationThis paper presents an analysis of queuing and propagation delays of Inter-Satellite Links (ISLs) in broadband Low-Earth Orbit (LEO) satellite networks. It is shown that queuing delays are negligible in all reasonable working conditions of the broadband ISL network. This fact makes it possible to simplify the routing protocols in such networks and permits using already known multi-commodity flow solutions for routing. The performance...
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The impact of air humidity on the operation of proton exchange membrane fuel cells determined using dynamic electrochemical impedance spectroscopy
PublicationThis paper describes the changes in the fuel cell impedance across a range of current loads and humidity changes. The changes of each equivalent circuit parameters representing specific processes occurring in fuel cells, as a function of humidity and current changes, were determined. Within the combined scope of current and humidity, the optimal working conditions of the cells were determined, corresponding to the lowest impedance...
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The system for remote monitoring of a vertical axis wind farm
PublicationThe article presents a system for remote monitoring of working parameters of a wind turbine with a vertical axis. The monitoring system was built using a Raspberry PI 3 microcomputer with the Raspbian operating system and a MicroDAQ E2000 measuring card. The developed system enables monitoring the power output of the generator, torque on the turbine shaft, turbine speed and wind speed. The values of the monitored parameters are...
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A prototype of electrochemical sensor for measurement of carbonyl compounds in air
PublicationThe paper presents the results of investigation on a prototype sensor for measurement of benzaldehyde and formaldehyde in air. Sensitivity, limit of quantification and coefficient of selectivity of the sensor have been determined as a function of membrane thickness and electrode type using square wave voltammetry (SWV) technique. The working and counter electrodes were made of platinum and gold. Ionic liquids 1-hexyl, 3-methylimidazolium...
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Method of sacrificial anode transistor-driving in cathodic protection system
PublicationA magnesium anode driving system has been proposed. A PNP driving transistor has been used. Electrochemical testing in 3%NaCl, results and comparison of the driving system and classic direct anode to cathode connection are presented. The driving system reduced the protection current and stabilized the working conditions of the anode. Higher anode efficiency was achieved. Overprotection and hydrogen embrittlement threats were prevented...
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The 5S methodology as a tool for improving organization of production
PublicationThe chapter presents the 5S method as a tool for continuous improving lean management processes, whose task is to create a highly efficient, clean, and ergonomic working environment. The method is presented as a collection of 5 simple rules, and at the same time it is a tool that allows you to control the workplace visually. The history of the 5S tool originates from Japanese philosophy, namely the five basic elements of the system: Seiri...
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Pracujący w czasie rzeczywistym system detekcji gazów wykorzystujący przenośny komputer Raspberry PI oraz matrycę półprzewodnikowych czujników gazu
PublicationThe gas-analyzing systems based on the array of partially selective gas sensors and pattern-recognition techniques are potentially fast and lowcost alternative for other devices, like gas‑analysers. They give the possibility of recognition the type and the concentration of measured volatile compounds in their working environment. In this work we present the implementation of gas recognition system, in which the signals from an...
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Experimental investigations on condensation in flow of HFE-7100 in small diameter channels
PublicationIn the paper the authors present investigations of flow condensation with the use of the HFE-7100 as a working fluid. The original and new approach to removing the heat from the channel was applied. The research was carried out using a wide-range real time observations, e.g. using infrared camera and stroboscope microphotography. This paper presents the details of experiment as well as the influence of heat and flow parameters...
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Hybrid biobateryy based on arylated carbon nanotubes and laccase
PublicationSingle-walled carbon nanotubes (SWCNT) were covalently modified with antracene and antraquinone and used for the construction of cathodes for biocatalytic reduction od dioxygen. The nanotubes with aromatic groups casted onto the electrode increased the working surface of the electrode and enabled efficient direct electron tarnsfer (DET) between the enzyme and the electrode. the aryl groups enter the hydrophobic pocket of the T1...
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Study of prototype multi-pole non-salient field winding for high speed brushless synchronous generator
PublicationIn this paper a non-salient field winding for a brushless synchronous generator working with high speed in an autonomous energy generation system (e.g. airplane power grid) has been presented. A conception of a six-pole cylindrical-rotor with distributed field winding has been proposed. Comparison study of salient and prototype non-salient field winding has been carried out. Chosen simulation and measurement results of the generator...
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Generalized adaptive comb filter with improved accuracy and robustness properties
PublicationGeneralized adaptive comb lters can be used to identify/track parameters of quasi-periodically varying systems.In a special, signal case they reduce down to adaptive comblters, applied to elimination or extraction of nonstationarymulti-harmonic signals buried in noise. We proposea new algorithm which combines, in an adaptive way, resultsyielded by several, simultaneously working generalizedadaptive comb lters. Due to its highly...
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Consolidating logs in varying formats into a structured repository = konsolidacja logów w zmiennych formatach do strukturalnego repozytorium
PublicationDuring multi-agent systems development, testing and re- search, possibly voluminous logs are created at distributed agent loca-tions. These logs describe individual agents behavior and state changes. To get the complete picture of the multi-agent system working, it is necessary to consolidate these logs and to store them in a format appropriate for diverse analyzes. Specic issues arise during consolidation if the log formats are...
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A universal IT system architecture for servicing, collecting, storing, processing and presenting data from wireless devices
PublicationIn the article we present a universal IT system architecture, which allows one to develop, based on mobile and multiplatform JAVA language, applications capable of working with many different wireless systems in an easy and effective way. Modular system architecture supports efficient data processing and enables convenient presentation of chosen parameters. Additionally, proposed IT system architecture provides easy adoption to...
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Eksperymentalna analiza wpływu ruchu posuwisto-zwrotnego i obrotowego oraz miejscowych zmian geometrii na skuteczność wypierania cieczy wiertniczych z przestrzeni pierścieniowej
PublicationRozprawa przedstawia analizę wpływu ruchu kolumny rur stosowanego w wiertnictwie oraz miejscowych zmian geometrii przestrzeni pierścieniowej na skuteczność procesu wypierania się cieczy. Jest to pierwsze badanie w otwartej literaturze omawiające te czynniki, w którym opisano wyniki eksperymentów na dedykowanym stanowisku badawczym. W pracy omówiony został wpływ węglowodorów na współczesną cywilizację, jak również wpływ skuteczności...
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Risking It All or Here Comes the Flood
PublicationThe professional reality is interdisciplinary! When city transformation and evolution starts, what are the tools for successful strategies for urban interventions? How does digital planning for digital fabrication processes look like? How dedicated are the new professionals? And how does this all influence the future of bridge design? More than 60 students representing various disciplines of built environment and working together...
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Smart Virtual Product Development: Manufacturing Capability Analysis and Process Planning Module
PublicationSmart Virtual Product Development (SVPD) system provides effective use of information, knowledge, and experience in industry during the process of product development in Industry 4.0 scenario. This system comprises of three primary modules, each of which has been developed to cater to a need for digital knowledge capture for smart manufacturing in the areas of product design, production planning, and inspection planning. Manufacturing...
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Long-Period Gratings and Microcavity In-Line Mach Zehnder Interferometers as Highly Sensitive Optical Fiber Platforms for Bacteria Sensing
PublicationSelected optical fiber sensors offer extraordinary sensitivity to changes in external refractive (RI), which make them promising for label-free biosensing. In this work the most sensitive ones, namely long-period gratings working at (DTP-LPG) and micro-cavity in-line Mach-Zehnder interferometers (µIMZI) are discussed for application in bacteria sensing. We describe their working principles and RI sensitivity when operating in water...
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Design and investigations of a micro-turbine flow part
Publication-generative micro-power plant with the HFE7100 as a working medium was designed and built for experimental investigations. The heat output of the plant was assumed equal to 20 kW, while the electric output amounted to about 3kW.In the paper a multi-stage micro-turbine with partial admission of all the stages is described in detail and the results of the particular experimental investigations and numerical calculations are shown,...
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Lighting conditions in home office and occupant’s perception: Exploring drivers of satisfaction
PublicationThis paper depicts lighting home office conditions within different countries and continents, emphasizing the user’s satisfaction with the visual environment. The scope of this article is to investigate the drivers of participants’ satisfaction with the lighting conditions at the home office. The study was developed by a team of international experts working together on Subtask A: User perspective and requirements, Task 61 IEA...
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Photoinduced electron transfer in 5-bromouracil labeled DNA. A contrathermodynamic mechanism revisited by electron transfer theories
PublicationThe understanding of the 5-bromouracil (BrU) based photosensitization mechanism of DNA damage is of large interest due to the potential applications in photodynamic therapy. Photoinduced electron transfer (ET) in BrU labeled duplexes comprising the 50 -GBrU or 50 -ABrU sequence showed that a much lower reactivity was found for the 50 -GBrU pattern. Since the ionization potential of G is lower than that of A, this sequence selectivity...
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Pipeline System for Heat Transportation from Nuclear Power Plant – an Optimizing Approach
PublicationOver the last few years heat piping insulation technology and pump systems efficiency have been significantly improved. Reduced thermal losses encourage heat transportation over long distances. It provides an opportunity for increasing thermodynamic efficiency of Nuclear Power Plants (NPPs) that are often located in rural areas because of safety issues. It can be achieved by Combined Heat and Power (CHP) generation, as heat produced...
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Micelle formation of Tween 20 nonionic surfactant in imidazolium ionic liquids
PublicationAggregation behavior of polyoxyethylene (POE)-type nonionic surfactant Tween 20 in imidazolium ionic liquids with varying chain length and different anions, such as tetrafluoroborate, hexafluorophosphate, bis(trifluoromethanesulfonyl)imide, and trifluoromethanesulfonate, was investigated by means of surface tension, conductivity and dynamic light scattering measurements. The role of the chain length, anion size as well as interactions...
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Investigation of ecological parameters of a gas turbine combustion chamber with steam injection for the floating production, storage, and offloading vessel
PublicationThe article is dedicated to the investigation of the possibility of using the contact type gas turbine cycle with steam injection into the combustion chamber for the floating production, storage, and offloading vessel in order to increase the specific power and efficiency and reduce emissions of toxic components. A new approach is proposed, associated with the use of the two-stage injection of superheated steam into a gas turbine...
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Polycyclic aromatic hydrocarbons as test probes to investigate the retention behavior of 1,3-alternate calix[4]arene silica-bonded stationary phases
PublicationA series of polycyclic aromatic hydrocarbons (PAHs) of different size and shape has been used to characterize the chromatographic behavior of five calix[4]arene stationary phases in 1,3-alternate conformation synthesized in our laboratory. The selection of linear, fourring nonlinear, and five-ring PAHs gave data on selectivity changes across range of the calix[4]arene columns. Retention of the 12 aromatic solutes has been evaluated...
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Superconductivity in CaBi2
PublicationSuperconductivity is observed with critical temperature Tc = 2.0 K in self-flux-grown single crystals of CaBi2. This material adopts the ZrSi2 structure type with lattice parameters a = 4.696(1) Å, b = 17.081(2) Å and c = 4.611(1) Å. The crystals of CaBi2 were studied by means of magnetic susceptibility, specific heat and electrical resistivity measurements. The heat capacity jump at Tc is DC/gTc = 1.41, confirming bulk superconductivity;...
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Why Are Left-Handed G-Quadruplexes Scarce?
PublicationG-quadruplexes (G4s) are nucleic acid structures crucial for the regulation of gene expression and genome maintenance. While they hold promise as nanodevice components, achieving desired G4 folds requires understanding the interplay between stability and structural properties, like helicity. Although right-handed G4 structures dominate the experimental data, the molecular basis for this preference over left-handed helicity is unclear....
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Informal employment in Poland: an empirical spatial analysis
PublicationThe main goal of our article is to bridge the gap in the regional analysis of informal employment in Poland and in particular to indicate the propensity for informal work in the working-age population, to test if informal activities are typical for marginalized people (less educated, unemployed, older) and to identify the regional and spatial heterogeneity in the propensity. We use data from the ‘Human Capital Balance 2010–2014’...
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Detection of person presence and its activity in the bathtub
PublicationA practical application of a bioimpedance technique for a detection of a bathing person is presented in the paper. It addresses the possibility of supervising people in the bathtub without voiding of their intimacy. The measurement system installed in a fiber-glass or a plastic bathtub is able to detect a presence of the bathing person, to estimate its activity and thus to detect potentially dangerous events. In the paper a principle...
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3D PCB package for GaN inverter leg with low EMC feature
PublicationThis paper presents the adaptation of a 3D integration concept previously used with vertical devices to lateral GaN devices. This 3D integration allows to reduce loop inductance, to ensure more symmetrical design with especially limited Common Mode emission, thanks to a low middle point stray capacitance. This reduction has been achieved by both working on the power layout and including a specific shield between the devices and...
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3D Model Preparing Patterns for Interactive Urban Visualization - Guidelines for Graphic Designers Preparing 3D Models for Virtual Reality Applications
PublicationWhile working on architectural visualizations, the software developer often has to work with graphic designers who create models in a different environment what can cause many complications. For this reason, it is very important to have some guidelines which can protect both the developer and the designer from commixing mistakes. The paper presents a list of such guidelines based on the authors’ experience. The reader can treat...
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ANALYSIS OF THE PROJECT OF INNOVATIVE FLOATING TURBINE
PublicationThe design of a floating, innovative device for river water aeration and conversion of mechanical energy to electrical energy required the analysis of a number of geometrical and dynamic features. Such an analysis may be carried out on the basis of existing methods of numerical fluid mechanics. Models of pressures, forces and torques characteristic for the conversion of watercourse energy were developed for two basic concepts of...
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Fluctuation of nitrogen fraction during wastewater treatment in a multistage treatment wetland
PublicationFactors influencing COD and removal and transformation of N fractions have been investigatedin the conditions of horizontal (SSHF) and vertical (SSVF) flow reed beds. Multistage treatment wetlandin Wiklino ensured a stable and very effective removal of all the analysed pollutants. Based onthe resultsof investigation, it could be assumed that the working conditions of SSHF beds play an importantrole in the transformation of particulate...
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Local atomic order in low Pt-content nanocatalysts investigated in situ by XAS
PublicationThe unique features of X-ray absorption spectroscopy allow investigations of nanosized catalysts for fuel cells under working conditions. We present the results of an experiment carried out on a low Pt content electrocatalyst supported by a mesoporous heteropolyacid salt and used at the cathode of a proton exchange membrane fuel cell (PEMFC). The analysis of the EXAFS signal at the Pt L3-edge indicates that upon operating the fuel...
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Koncepcja i symulacja polowa generatora o zmiennej częstotliwości. Zastosowanie w autonomicznych systemach elektroenergetycznych = Conception and field simulations of a variable frequency generator. Application for autonomous power generation system
PublicationStreszczenie angielskie: This paper covers a conception and simulation results for a brushless synchronous generator working with variable speed in an autonomous energy generation system (e.g. airplane power grid, hybrid vehicle, micro-CHP). The papers has two parts: presentation of the generator conception used in modern autonomous energy generation systems, and simulation results using filed model elaborated in Flux2D software....
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EXHAUST TEMPERATURE MEASUREMENTS OF THE MARINE TURBOCHARGED DIESEL ENGINES IN OPERATION
PublicationThe article presents the selected metrology issues concerning the exhaust temperature of the turbocharged marine engines during operation. The special concern has been paid on existing disturbances as well as thermodynamical interpretation of the recorded measurement signal. A diagnostic informativeness of the standard exhaust temperature’s measurements has worked out while the engine runs in steady states has been also considered...
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Hydrogen sulphide electrocatalytic gas sensor
PublicationIn this article measurement results of the electrocatalytic gas sensor in different concentrations of hydrogen sulphide are presented. Working principle of such sensor is based on electric current acquisition, while voltage ramp is applied to the sensor. During voltage sweep oxidation and reduction reactions occurs on the sensor electrodes. Obtained current-voltage plot has unique shape connected...
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Study of Direct Methanol Fuel Cell Process Dynamics Using Dynamic Electrochemical Impedance Spectroscopy
PublicationA new technique, which was developed to characterize the direct methanol fuel cell under work conditions, has been presented in this paper. The impedance measurements were made using dynamic electrochemical impedance spectroscopy research technique in the galvanostatic mode, using multiple sinusoidal excitation. Obtained results show, that together with an increase of the temperature and working load, the global impedance...
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Electrochemical sensor for measurement of volatile organic compounds employing square wave perturbation voltage
PublicationThe paper presents the results of investigation on a prototype sensor for measurement of benzaldehyde in air. Sensitivity and limit of quantification of the sensor were determined for different internal electrolyte using the square wave voltammetry (SWV) as a detection technique. The working and counter electrodes were made of platinum. Ionic liquids 1-hexyl, 3-methylimidazolium chloride,1-hexyl, 3-methylimidazolium bis (trifluoromethanesulfonyl)...
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Galerkin Finite Element Process for Entropy Production and Thermal Evaluation of Third-Grade Fluid Flow: A Thermal Case Study
Publication: A fluid’s moving class improves its heat transmission capability, as well as its rigidity, owing to multivariate molecule suspension. In this way, nanofluids are superior to common fluids. In this study, we evaluated the features of ease and heat transfer. Furthermore, we investigated permeable media, heat source, variable heat conductivity, and warm irradiation results. A mathematical technique known as the Galerkin finite element...
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Antibacterial properties of laser-encapsulated titanium oxide nanotubes decorated with nanosilver and covered with chitosan/Eudragit polymers
PublicationTo provide antibacterial properties, the titanium samples were subjected to electrochemical oxidation in the fluoride-containing diethylene glycol-based electrolyte to create a titanium oxide nanotubular surface. Afterward, the surface was covered by sputtering with silver 5 nm film, and the tops of the nanotubes were capped using laser treatment, resulting in an appearance of silver nanoparticles (AgNPs) of around 30 nm in diameter...
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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 laminar jets which when impinging the surface have a very high kinetic energy at the stagnation point. Boundary layer is not formed in those conditions, while the area of film cooling has a very high turbulence resulting from a very high heat transfer coefficient. Applied technology of jet production can result with the size of jets ranging from 20 to 500μm in breadth and 20 to 100μm...
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Metodyka badań rozwojowych nowego typu silników i pomp satelitowych
PublicationResearch and development of new type satellite motors and satellite pumps SM with small geometrical displacement, from 5 to 73 cm3/rev, has been conducted in cooperation with Stosowanie Maszyn company from Katowice (manufacturer of motors and pump SM). The improvement of construction of those machines, especially construction of axial compensation and construction of fluid distribution channels have been the main problem of research...
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Smart Virtual Product Development (SVPD) System to Support Product Inspection Planning in Industry 4.0
PublicationThis paper presents the idea of supporting product inspection planning process during the early stages of product life cycle for the experts working on product development. Aim of this research is to assist a collaborative product development process by using Smart Virtual Product Development (SVPD) system, which is based on Set of Experience Knowledge Structure (SOEKS) and Decisional DNA (DDNA). The proposed system is developed...