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Search results for: PERFECT THERMAL CONTACT
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Jacek Ryl dr hab. inż.
PeopleI have obtained my PhD in chemical technology in 2010. In the same year, I was employed at the Department of Electrochemistry, Corrosion and Materials Engineering at the Faculty of Chemistry. In 2018 I received habilitation at the Faculty of Chemistry GUT in technical sciences in the discipline of chemical technology. From 2021, he was employed at the Institute of Nanotechnology and Materials Science at the Faculty of Technical...
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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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Determination of t8/5 cooling times for underwater local dry welding of steel
PublicationKnowledge of thermal history is the basic condition for studying the structure - properties of welded joints. The determinant of thermal history is the thermal cycle, whose in-situ measurements are still a big challenge. Water as the welding environment complicates this issue even more. The article presents a method to determine an equation for calculating t8/5 cooling times for underwater gas metal arc welding of unalloyed steels...
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"Kanalizacja obszaru Parku Krajobrazowego Puszcza Zielonka i okolic - Kontrakt VI - Zlewnia Centralnej Oczyszczalni Ścieków w Koziegłowach - Zadanie 1 - Gmina SWARZĘDZ"
PublicationAnaliza kinet monolitycznych w technologii PERFECT. Różnice w stosunku do tradycyjnych kinet obcych. Charakterystyczne cechy mnateriałowe betonów
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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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Numerical analysis of crack propagation in silicone nitride
PublicationThe properties of ceramics, specifically low density, high hardness, high temperature capability and low coefficient of thermal expansion are of most interest to rolling element manufacturers. The influence of ring crack size on rolling contact fatigue failure has been studied using numerical fracture analysis. Such cracks are very often found on ceramic bearing balls and decrease fatigue life rapidly. The numerical calculation...
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Exact-match Based Wikipedia-WordNet Integration
PublicationAbility to link between WordNet synsets and Wikipedia articles allows usage of those resources by computers during natural language processing. A lot of work was done in this field, however most of the approaches focus on similarity between Wikipedia articles and WordNet synsets rather than creation of perfect matches. In this paper we proposed a set of methods for automatic perfect matching generation. The proposed methods were...
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Calculation of an ultimate load value of a silo with geometric imperfections in the shape of eigenforms
PublicationThe ultimate load value of a silo with initial geometric imperfections was measured. The structure was loaded with wind. Imperfections were assumed as translations of the shell nodes from perfect geometry taken from eigenforms and their combinations. Two variants of the maximum deflection placement with respect to the direction of wind pressure were proposed. The first consists in applying the maximum wind pressure to the element...
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Application of Stirling Engine Type Alpha Powered by the Recovery Energy on Vessels
PublicationThe Stirling engine is a device, in which thermal energy is transformed into mechanical without a contact between the heat carrier, and the working gas closed in the engine. Mentioned feature makes this type of engine very attractive for the use of the recovery energy, taken from other heat devices. One of the potential applications of Stirling engines is the use of thermal energy generated in the ship's engine room for producing...
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Mateusz Kopec Dr hab. inż.
PeopleHead of the Materials and Structural Testing Laboratory in Institute of Fundamental Technological Research PAS and Academic visitor in Imperial College London. Lecturer and Master/PhD students supervisor in Doctoral School of IPPT PAN and TIB PAN, and Imperial College London. Member of Polish Materials Science Society, Member of the Board of Polish Society of Theoretical and Applied Mechanics, and Council Member of the European...
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Radosław Szmytkowski prof. dr hab.
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Karolina Zielińska-Dąbkowska dr inż. arch.
PeopleKarolina M. Zielinska-Dabkowska, Ph.D., Eng. Arch., M. Arch., is an Assistant Professor at the Faculty of Architecture of Gdańsk University of Technology (GUT). In 2002, she completed her studies of Architecture and Urban Planning at Gdańsk University of Technology (Gdańsk Tech) and in 2004, Architectural Engineering at the University of Applied Sciences and Arts (HAWK) in Hildesheim, Germany. After graduation, she worked for several...
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Topographic AFM imaging of the leaf surface with magnification of details of its morphological structure
Open Research DataTopographic imaging of the leaf surface with magnification of details of its morphological structure. Measurements in semi-contact mode. NTEGRA Prima (NT-MDT) device. NSG 01 probe.
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O MNIEJ LUB BARDZIEJ SŁODKIM CUKRZE, CZYLI KILKA UWAG O ODPOWIEDZIALNOŚCI SPOŁECZNEJ FIRM RODZINNYCH I PRZEDSIĘBIORSTW SPOŁECZNYCH
PublicationW artykule, przyjmując za punkt wyjścia teorię interesariuszy Freemana, autorki podjęły się refleksji na temat specyfiki odpowiedzialności społecznej firm rodzinnych i przedsiębiorstw społecznych. Przedsiębiorstwa społeczne, uznawane są powszechnie za ucieleśnienie pełnej, wręcz doskonałej formy odpowiedzialności społecznej. Z kolei przedsiębiorstwa rodzinne, charakteryzują się szczególną paletą interesariuszy oraz specyficznymi...
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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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Selected aspects of two-phase flow studies using different visualization techniques in minichannels
PublicationThe subject of the study is to present the possibility of the use of visualization techniques in the researches on two-phase flows, carried out by the authors for many years. These works included as follows: heat transfer during the flow boiling, boiling crises and condensation in flow. The issue of the heat transfer intensification during the flow boiling through the channels of small diameters was analyzed. All this work focused...
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Properties of the triset metric for phylogenetic trees
Publicationthe following paper presents a new polynomial time metric for unrootedphylogenetic trees (based on weighted bipartite graphs and the method ofdetermining a minimum perfect matching) and its properties. also many its properties are presented.
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Justyna Kucińska-Lipka dr hab. inż.
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Susceptibility to Degradation in Soil of Branched Polyesterurethane Blends with Polylactide and Starch
PublicationA very important method of reducing the amount of polymer waste in the environment is the introduction to the market of polymers susceptible to degradation under the influence of environmental factors. This paper presents the results of testing the susceptibility to degradation in soil of branched polyesterurethane (PUR) based on poly([R,S]-3-hydroxybutyrate) (R,S-PHB), modified with poly([D,L]-lactide) (PLA) and starch (St). Weight...
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On possible applications of media described by fractional-order models in electromagnetic cloaking
PublicationThe purpose of this paper is to open a scientific discussion on possible applications of media described by fractional-order (FO) models (FOMs) in electromagnetic cloaking. A 2-D cloak based on active sources and the surface equivalence theorem is simulated. It employs a medium described by FOM in communication with sources cancelling the scattered field. A perfect electromagnetic active cloak is thereby demonstrated with the use...
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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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Atomic force microscopy images of copper electrical contacts wear under the influence of friction
Open Research DataMeasurement of wear of copper electrical contacts under the influence of friction. Imaging in contact mode in the variant of scanning spreading resistance microscopy. Additionally, there are spectroscopic current-voltage curves showing local changes in electrical conductivity. NTEGRA Prima (NT-MDT) device. Probe NSG 01Pt.
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Rozmyty system wnioskowania do oszacowania maksymalnego naprężenia kontaktowego na powierzchni panewki endoprotezy stawu biodrowego w zależności od kąta Wiberga i masy ciała pacjenta = Fuzzy reasoning system for maximal contact stress estimation on acetabular surface in hip endoprosthesis based on Wiberg angle and weight of patient
PublicationPrzedstawiono możliwość wykorzystania systemu rozmytego, który wykorzystując rozumowanie przybliżone określa maksymalne naprężenie kontaktowe na powierzchni przenoszenia obciążeń panewki endoprotezy stawu biodrowego, biorąc pod uwagę kąt Wiberga oraz masę ciała pacjenta.
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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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Paweł Wierzba dr hab. inż.
PeopleDr Paweł Wierzba, E.E. M.Sc. E.E. received from WETI PG 1994 PhD in optoelectronics (with honours) from WETI PG 2001 Research Stays at VTT Technical Research Centre of Finland from 1997 to 2000 Finnish Academy Scholarship at VTT Technical Research Centre of Finland (12 months) 2002-3 Research interest area covers optical and optical fiber meaurement methods, technology of selected ceramic and liquid crystalline materials relevant...
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Polymer based thick films - material quality and interface resistance evaluation
PublicationThe properties of polymer based thick film layers mede using different resistive pastes and dipping silvers have been studied. The composite of carbon and graphite (C/Gr) conducting particles suspended in different polymer vehicles were used for preparation resistive layers. Interface resistance Rc created between dipping silver (DiAg) contact layer and resistive layer was determined from the surface potential distribution measurements...
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Krzysztof Jan Kaliński prof. dr hab. inż.
PeopleKrzysztof J. Kaliński completed his MSc study at Gdańsk University of Technology (GUT) Faculty of Production Engineering (1980, result – get a first). He obtained PhD at GUT Faculty of Machine Building (1988, result – get a first), DSc at GUT Faculty of Mechanical Engineering (ME) (2002, result – get a first), and professor’s title – w 2013 r. In 2015 r. he became full professor.His research area includes: theoretical and applied...
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The Influence of Articular Cartilage Thickness Reduction on Meniscus Biomechanics
PublicationObjective Evaluation of the biomechanical interaction between meniscus and cartilage in medial compartment knee osteoarthritis. Methods The finite element method was used to simulate knee joint contact mechanics. Three knee models were created on the basis of knee geometry from the Open Knee project. We reduced the thickness of medial cartilages in the intact knee model by approximately 50% to obtain a medial knee osteoarthritis...
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The Influence of Thin Gold Electrodes on the High-Temperature Impedance of Oxide Glasses
PublicationThe influence of thin gold electrodes on the electrical measurements of glasses at high temperatures was studied using impedance spectroscopy. The impedance was measured several times over a wide frequency range from 10 mHz to 1 MHz and the temperature ranged from 213 to 673 K under air and nitrogen atmospheres. The results showed a drop in the conductivity of more than an order of magnitude at a temperature around 603 K during...
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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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Optimization of the distance between the vertical plates in the convective air heat exchanger
PublicationThis paper examines the influence of the distance between vertical plates on the intensity of free convective heat transfer along with the optimization of this distance. Experimental tests were carried out for one model channel of such an heat exchanger with widths , 0.085 and 0.18 m. This channel, open at the top and sides, was formed by two isothermal symmetrically heated parallel vertical plates of dimensions m and m. The influence...
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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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Numerical analysis of the carpentry joints applied in the traditional wooden structures
PublicationThe paper concerns the numerical analysis of the carpentry joints made from spruce wood. The material parameters of the wood have been calculated on the basis of nine independent material constants (an orthotropic material). The contact zone between the individual elements of the connection has been determined using Contact Tables in the MSC.Marc software. Five types of carpentry joints have been analyzed. The main aim of the research...
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PROBLEMS OF THE STARTING AND OPERATING OF HYDRAULIC COMPONENTS AND SYSTEMS IN LOW AMBIENT TEMPERATURE (PART IV) MODELLING THE HEATING PROCESS AND DETERMINING THE SERVICEABILITY OF HYDRAULIC COMPONENTS DURING THE STARTING-UP IN LOW AMBIENT TEMPERATURE
PublicationDesigners of hydraulically driven machines and devices are obliged to ensure during design process their high service life with taking into account their operational conditions. Some of the machines may be started in low ambient temperature and even in thermal shock conditions (due to delivering hot working medium to cold components). In order to put such devices into operation appropriate investigations, including experimental...
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Influence of Surface-Modified Montmorillonite Clays on the Properties of Elastomeric Thin Layer Nanocomposites
PublicationIn recent years, polyurethane nanocomposites have attracted more attention due to the massive demand for materials with increasingly exceptional mechanical, optical, electrical, and thermal properties. As nanofillers have a high surface area, the interaction between the nanofiller and the polymer matrix is an essential issue for these materials. The main aim of this study is to validate the impact of the montmorillonite nanofiller...
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Structural analysis and physico-chemical characterization of mononuclear manganese(II) and polynuclear copper(II) complexes with pyridine-based alcohol
PublicationTwo novel manganese(II) and copper(II) complexes, mononuclear [Mn(H2O)2(2-(CH2)2OHpy)2](NO3)2 (1) and polynuclear [Cu(SO4)(2-(CH2)2OHpy)2]n (2), based on 2-(hydroxyethyl)pyridine (2-(CH2)2OHpy) were synthesised and fully characterised using X-ray structure analysis as well as spectroscopic, magnetic and thermal methods. Both central metal ions Mn(1) and Cu(1) are coordinated by two N,O-donor 2-(CH2)2OHpy ligands and possess an...
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Electrochemical Activity of Electrode Material Consisting of Porous Copper and Silica Aerogel
PublicationElectrochemically obtained copper was combined with silica aerogel (SiO2ag). Obtained composite (SiO2@Cu/CuxOy) was tested as an electrode in contact with LiPF6 in EC/DMC electrolyte. The electrochemical measurements showed the presence of complex redox couple activities of SiO2@Cu/CuxOy. This experiment was employed to help in understanding the carbon role used as an electric contact for silica in Li-Ion batteries and clarify...
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Topological extraordinary optical transmission
PublicationΤhe incumbent technology for bringing light to the nanoscale, the near-field scanning optical microscope, has notoriously small throughput efficiencies of the order of 10^4-10^5 or less. We report on a broadband, topological, unidirectionally guiding structure, not requiring adiabatic tapering and, in principle, enabling near-perfect (∼100%) optical transmission through an unstructured single arbitrarily subdiffraction slit at...
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Comparison of buckling resistance of columns modelled by beam and shell elements using non-linear analysis
PublicationThe aim of the paper is to investigate the stability process in the axially compressed columns modelled by beam and shell elements using static and dynamic finite element analysis by taking both the geometric and material non-linearity into account. The perfect columns and columns with geometric imperfections were analysed. The differences between the results of static and dynamic analyses in shell and beam models were discussed.
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Visual measurement system for chosen parameters of current collectors
PublicationA current collector is an element in a traction vehicle, used for movable, contact con-nection between the main circuit of this vehicle and the contact line. Bad technical condi-tion of these important elements in the main circuit of the vehicle result in its incorrect cooperation with contact line. Periodic control of technical condition of current collectors ensures infallible current collection. The pantograph diagnostics consists...
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Team project I (2020/21)
e-Learning CoursesWithin this team project, students will be designing a space mission. Each student will choose a subsystem: mission analysis, propulsion, communication, structure, mechanisms, power, thermal, onboard data handling. Together, by means of concurrent engineering a primary system definition will be completed.
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Marcin Sikorski prof. dr hab. inż.
PeopleMarcin Sikorski is a professor at the Department of Informatics in Management at the Faculty of Management and Economics of the Gdańsk University of Technology. Earlier he had numerous fellowships in academic institutions, among others in Germany (Universities in Bonn and in Heidelberg), Switzerland (ETH Zurich), the Netherlands (TU Eindhoven) and the USA (Harvard University). Professor Sikorski is a representative of Poland in...
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Wettability of Horizontal Stainless Steel Tube by Nanofluid Droplets
PublicationThe goal of the present work was the experimental determination of the contact angle of three nanofluids, i.e. water-Al2O3, water-Cu and water-TiO2 on horizontal stainless steel tube of 1.6 mm OD. Of particular interest was the effect of nanoparticle concentration (0.01%, 0.1%, and 1% by weight) on droplet contact angle.
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Wettability of Horizontal Stainless Steel Tube by Nanofluid Droplets
PublicationThe goal of the present work was the experimental determination of the contact angle of three nanofluids, i.e. water-Al2O3, water-Cu and water-TiO2 on horizontal stainless steel tube of 1.6 mm OD. Of particular interest was the effect of nanoparticle concentration (0.01%, 0.1%, and 1% by weight) on droplet contact angle.