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Wyniki wyszukiwania dla: DISPERSED PHASE
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Effects of subfilter velocity modelling on dispersed phase in LES of heated channel flow
PublikacjaA non-isothermal turbulent flow with the dispersed phase is modelled using the Large Eddy Simulation (LES) approach for fluid, one-way coupled with the equations of point-particle evolution. The channel is heated at both walls and isoflux boundary conditions are applied for fluid. Particle velocity and thermal statistics are computed. Of particular interest are the r.m.s. profiles and the probability density function of particle...
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The influence of type of dispersed phase on rolling contact fatigue of lubricating greases on mineral base oil
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Measurements of Dispersed Phase Velocity in Two-Phase Flows in Pipelines Using Gamma-Absorption Technique and Phase of the Cross-Spectral Density Function
PublikacjaThis paper concerns the application of the gamma radiation absorption method in the measurements of dispersed phase velocity in two-phase flows: liquid–gas flow in a horizontal pipe- line and liquid–solid particles in a vertical pipe. Radiometric sets containing two linear 241Am gamma radiation sources and two NaI(Tl) scintillation detectors were used in the research. Due to the stochastic nature of the signals obtained from the...
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Influence of dispersed phase content on the mechanical properties of electroless nanocomposite Ni-P/Si3N4 and hybrid Ni-P/Si3N4/graphite layers deposited on the AW-7075 alloy.
PublikacjaThe article presents the results of mechanical testing of Ni-P/Si3N4 nanocomposite and hybrid Ni-P/Si3N4/graphite coatings deposited on AW-7075 aluminum alloy using the chemical reduction method. In terms of mechanical testing, microhardness was measured, and surface roughness and adhesion of the coatings to the aluminum substrate were determined using the “scratch test” method. The surface morphology of the deposited layers was...
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Dielectric Properties of BiNbO<sub>4</sub>-Based Ceramic-Polymer Composites with 0-3 Connectivity
PublikacjaIn the present study two-phase BiNbO4//PVDF composites with 0-3 connectivity were studied by impedance spectroscopy within the frequency range Δν=100Hz-1MHz at room temperature. Polyvinylidene fluoride (PVDF) acted as a matrix whereas bismuth niobate (BiNbO4) powder acted as a dispersed phase. The volume fraction of the ceramic phase was cV=2, 4, 6, 8, 10, 16 and 20vol%. Analysis of the impedance data registered for composites...
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Signal Processing in the Investigation of Two-phase Liquid-gas Flow by Gamma-ray Absorption
Publikacjan this paper, the use of the gamma-absorption method applied in the investigation of the two-phase liquid-gas flow in the pipeline is described. An example of its application to the air transported by water in a horizontal pipeline is evaluated. In the measurements, Am-241 radioactive sources and probes with Nal (Tl) scintillation crystals have been used. The signals from the radiometric set were used to determine the velocity...
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The influence of polypropylene-block/graft-polycaprolactone copolymers on melt rheology, morphology, and dielectric properties of polypropylene/polycarbonate blends
PublikacjaThe paper discusses the relationship between rheology and morphology of immiscible polypropylene (matrix))/polycarbonate (dispersed phase) blends compatibilized with novel polypropylene-polycaprolactone block and graft copolymers. Transmission electron microscopy (TEM) experiments revealed uniform droplet morphologies and a reduction of the average size of the dispersed phase upon addition of the compatibilizer. The results suggested...
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Radioisotope measurement of selected parameters of liquid-gas flow using single detector system
PublikacjaTo determine the parameters of two-phase flows using radioisotopes, usually two detectors are used. Knowing the distance between them, the velocity of the dispersed phase is calculated based on time delay estimation. Such a measurement system requires the use of two gamma-ray sealed sources. But in some situations it is also possible to determine velocity of dispersed phase using only one scintillation probe and one gamma-ray source....
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Effect of alkyl sulfate on the phase behavior of microemulsions stabilized with monoacylglycerols
PublikacjaIn this study the effect of an anionic surfactant (sodium dodecyl sulfate SDS) and oils (hydrocarbons: C12-C16) on the formation and phase behavior of the systems of oil/monoacylglycerols (MAG):SDS/propylene glycol/water has been investigated. The effects of the surfactant mixture on the phase behavior and the concentrationof water or oil in the systems were studied at three temperatures (50, 55, 60 C). Electrical conductivity...
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The Influence of Nanometals, Dispersed in the Electrophoretic Nanohydroxyapatite Coatings on the Ti13Zr13Nb Alloy, on Their Morphology and Mechanical Properties
PublikacjaIn this work, nanohydroxyapatite coatings with nanosilver and nanocopper have been fabricated and studied. The presented results concern coatings with a chemical composition that has never been proposed before. The present research aims to characterize the effects of nanosilver and nanocopper, dispersed in nanohydroxyapatite coatings and deposited on a new, non-toxic Ti13Zr13Nb alloy, on the physical and mechanical properties of...
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Time Delay Estimation in Two-Phase Flow Investigation Using the γ-Ray Attenuation Technique.
PublikacjaTime delay estimation is an important research question having many applications in a range of technologies. Measurement of a two-phase flow in a pipeline or an open channel using radioisotopes is an example of such application. For instance, the determination of velocity of dispersed phase in that case is based on estimation of the time delay between two stochastic signals provided by scintillation probes. The proper analysis...
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Comparison of noise reduction methods in radiometric correlation measurements of two-phase liquid-gas flows
PublikacjaTwo-phase liquid-gas flows occur frequently in the mining, energy, chemical, and petrochemical industries. One of non-contact methods used to analyse these flows is the gamma ray absorption method. However, the signals received from radiation detectors contain a significant stochastic noise, which makes them difficult to analyse. The article describes four methods of noise reduction in cross-correlation measurements of water-air...
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Development of nanoscale morphology and role of viscoelastic phase separation on the properties of epoxy/recycled polyurethane blends
PublikacjaA novel and cost-effective approach towards the modification of epoxy matrix has been developed using recycled polyurethane for the first time without sacrificing any of the intrinsic properties of the resin. Polyurethane, recycled from waste foam by glycolysis process (RPU), was found to be very effective in improving the properties of the thermosetting resin based on Diglycidyl ether of bisphenol-A (DGEBA). The effect of the...
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A New Microwave Ceramic – Polymer Composite with 0-3 Connectivity
PublikacjaGoal of the present research was to fabricate and study two-phase BiNbO4//PVDF composites with 0-3 connectivity. Such composite consists of there-dimensionally connected polymer matrix loaded with dielectric ceramic particles. In the present case BiNbO4 powder acted as an active phase (dispersed phase) whereas polyvinylidene fluoride (PVDF) acted as a non-active (passive) phase (matrix). BiNbO4//PVDF composites with the volume...
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Investigation of Liquid–Gas Flow in a Horizontal Pipeline Using Gamma-Ray Technique and Modified Cross-Correlation
PublikacjaThis article presents the application of the radioisotope absorption method in the study of two-phase water–air flow in a horizontal pipe. The measurement principle and the test stand are briefly described. The main part of the article presents the signal analysis methods applied to data obtained from scintillation detectors. Because these signals are mostly stochastic waveforms, they were analyzed statistically using the cross-correlation...
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Experimental investigations and simulations of the microturbine unit with permanent magnet generator
PublikacjaIn dispersed power generation, low power devices are used for local combined generating of heat end electric power. There are developing concepts of micropower plants with electric generators driven by steam or gas microturbines. The paper presents the results of an experimental investigations of the microturbine set consists of the turbine with partial admission, permanent magnet generator and three phase AC-to-DC rectifier. The...
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Water Solubilization Using Nonionic Surfactants from Renewable Sources in Microemulsion Systems
PublikacjaIn this study the effect of temperature, NaCl andoils (hydrocarbons: C8-C16) on the formation and solubilizationcapacity of the systems of oil/monoacylglycerols(MAG):ethoxylated fatty alcohols (CEO20)/propylene glycol(PG)/water was investigated. The effects of the surfactantmixture on the phase behavior and the concentration ofwater or oil in the systems were studied at three temperatures(50, 55, 60 C) and with varied NaCl solutions...
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Transparent thin films of Cu-TiO2 with visible light photocatalytic acitivity
PublikacjaThin films of Cu–TiO2 with a high level of transparency were prepared by a dip-coating procedure on the glass surface. CuCl2 was used as a copper precursor added during sol – gel synthesis of TiO2. The extension of optical absorption into the visible region of as-prepared thin films was indicated by UV/Vis spectroscopy. Only the anatase phase was detected by X-ray di ffraction analysis (XRD). The presence of copper in the structure...
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Synthesis of isotactic polypropylene- block -polystyrene block copolymers as compatibilizers for isotactic polypropylene/polyphenylene oxide blends
PublikacjaPoly(2,6-dimethyl-1,4-phenylene oxide) (PPO) and isotactic polypropylene (iPP) are highly incompatible and consequently their uncompatibilized blends are quite brittle regardless of the molecular weights and ductility of the individual components. Isotactic polypropylene-polystyrene block copolymers, to be applied as compatibilizers for a broad range of PPO/iPP blend compositions, were prepared by mechanism transformation from...
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CO2 capture using steam ejector condenser under electro hydrodynamic actuator with non-condensable gas and cyclone separator: A numerical study
PublikacjaThe concept for condensation of steam and CO2 separation in a negative CO2 emission gas power plant involves the utilization of a steam ejector condenser (SEC) for direct-contact condensation of vapor with inert gas (CO2) on a spray of subcooled liquid, integrated with a separator to produce pure CO2. Due to the increasing diffusion resistance and reduced convective heat transfer between the steam and subcooled water phases...
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Characterization of PVDF/Graphene Nanocomposite Membranes for Water Desalination with Enhanced Antifungal Activity
PublikacjaSeawater desalination is a worldwide concern for the sustainable production of drinking water. In this regard, membrane distillation (MD) has shown the potential for effective brine treatment. However, the lack of appropriate MD membranes limits its industrial expansion since they experience fouling and wetting issues. Therefore, hydrophobic membranes are promising candidates to successfully deal with such phenomena that are typical...
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CO2 capture through direct-contact condensation in a spray ejector condenser and T- junction separator
PublikacjaThe design principle underlying the steam condensation and CO2 purification in a gas power plant with a focus on reducing CO2 emissions encompasses the deployment of a spray ejector condenser (SEC) and separator. This innovative system facilitates direct-contact condensation of steam with non-condensable gas (CO2) by inter acting with a spray of subcooled water, seamlessly integrated with a T-junction separator mechanism aimed...
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Effect of gelation and storage conditions on the oxidative stability of microemulsion and nanoemulsion delivery systems
PublikacjaIncreased interest in the use of microemulsion and nanoemulsion delivery systems for medical, cosmetic and food purposes, promotes the development of research on their physical and chemical stability, and the safety of use. Here, we have for the first time evaluated the oxidative stability of linseed oil dispersed in the microemulsion, nanoemulsion, and their gelled systems, stored under different conditions, and compared to the...
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Structure of Microemulsion Formulated with Monoacylglycerols in the Presence of Polyols and Ethanol
PublikacjaThe influence of polyols as cosurfactants (propylene glycol PG; glycerol G) and short chain alcohol as a cosolvent (ethanol EtOH) on the formation and solubilization capacity of the systems: hexadecane/monoacylglycerols (MAG)/polyol/water:EtOH, at 60C, was investigated. Electrical conductivity measurement, and the DSC method were applied to determine the structure and type of microemulsions formed. The dimension of the droplets...
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pH-dependent composite coatings for controlled drug delivery system - Review
PublikacjaNowadays in case of long-term implants, the most common postoperative complications are bacterial infections, which in consequence may provoke loos- ening of the implants in the primary phase of stabilization. Bacterial infections are currently the most frequent cause of revision surgery of the implants such as hip joint endoprosthesis, knee joint endoprosthesis and dental implants. In order to provide the local and long-term antibacterial...
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A study on fibre-reinforced concrete elements properties based on the case of habitat modules in the underwater sills
PublikacjaHydrotechnical constructions are mostly objects functioning in extreme conditions and requiring a custom-made construction project. In the case of using prefabricated elements, it is required to develop production, transport, assembly, conservation and repair technology. Concerning the problem of concrete cracks, modern repair systems allow positive effects to be achieved in many cases of concrete elements repair. In this work...
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Hyperbranched polyethylenimine functionalized silica/polysulfone nanocomposite membranes for water purification
PublikacjaHyperbranched polyethyleneimine functionalized silica (PEI-SiO2) nanoparticles with considerable hydrophilicity were synthesized and incorporated into a polysulfone (PSF)/dimethylacetamide (DMA)/polyvinylpyrrolidone (PVP) membrane casting solution in five different ratios to fabricate PEI-SiO2/PSF nanocomposite membranes using nonsolvent-induced phase separation. The hydrophilic PEI-SiO2 nanoparticles were characterized by TEM,...
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Micro-cracking pattern recognition of hybrid CNTs/GNPs cement pastes under three-point bending loading using acoustic emission technique
PublikacjaThe generation of microcracks has an important influence on the behaviour of concrete structures. In this study, the acoustic emission (AE) technique was used to investigate the fracture phenomena and micro-cracking behavior of hybrid carbon nanotubes (CNTs, the 1-D allotrope of carbon atoms) and graphene nanoplatelets (GNPs, 2D monolayer of sp2-hybridized carbon atoms), cement composites under three-point bending loading. In...
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Recycled rubber wastes-based polymer composites with flame retardancy and electrical conductivity: Rational design, modeling and optimization
PublikacjaPolymer recycling techniques experience a maturity period of design and application. Rubbers comprise a high proportion of polymer wastes, highly flammable and impossible to re-melt. Polymer composites based on ground tire rubber (GTR) and ethylene-vinyl acetate copolymer (EVA) containing carbon black (CB) (1–50 phr), with variable EVA/GTR weight composition (10/90, 25/75, 50/50, 75/25 and 90/10), and processing temperature (Low:...
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The Creation of an Antimicrobial Coating on Contact Lenses by The Use of Nanocopper
PublikacjaThe aim of the research was to creation an antimicrobial coating on contact lens and examine the ability of copper nanoparticles to decrease microbial adhesion and prevent the growth of bacteria. The creation was based on the immersion method in solution with dispersed nanoparticles of copper at concentration 200 pm. There were evaluated follows factors: time of immersion and base to dispersed nanoparticles. Three solutions: ethyl...
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Specificity of automatic control of micro-turbines (steam or gas -driven and expanders) in dispersed generation system of heat and electric power
PublikacjaThis paper presents specific problems of automatic control of steam micro-turbines and expanders intended for the dispersed, combined generating of heat and electric power. The investigations concern ensurance of certainty of energy supply and its required quality.
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Blast Charge Technique as a Method of Soil Improving to Locate the New Supporting Runways
PublikacjaA quick and effective method of reinforcing the ground base designed for the construction of engineering structures used for performing various types of air operations was presented. It allows to use wastelands, wetlands, swamps, etc. for these purposes, thus creating a dispersed network of landing sites, increasing the access of large social groups to air transport and increasing their mobility.
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A concept of measurement system based on the Z-Wave standard
PublikacjaIn the paper a new concept of measurement system based on the Z-Wave standard is presented. This standard is dedicated to use mainly in home automation systems, but its properties enable to use it in dispersed measurement systems and support wireless communication between measurement nodes in a mesh-type network. In the paper basic metrological aspects of the Z-Wave standard and an example of impedance measurement system are discussed.
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High-efficiency mini and micro heat exchangers for dispersed power generation
PublikacjaTaking into account the dispersed systems technologies and their development, the ORC systems seem to be promising technology amongst various micro-CHP domestic units (electrical power production below 10 kWe), however practical realization of the ORC cycle in a micro-scale is technically challenging. The system consists in devices such as the vapour generation unit (boiler), expansion device and heat exchangers. Each of them should...
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O 1s excitation and ionization processes in the CO2 molecule studied via detection of low-energy fluorescence emission
PublikacjaOxygen 1s excitation and ionization processes in the CO2 molecule have been studied with dispersed and non-dispersed fluorescence spectroscopy as well as with the vacuum ultraviolet (VUV) photon-photoion coincidence technique. The intensity of the neutral O emission line at 845 nm shows particular sensitivity to core-to-Rydberg excitations and core-valence double excitations, while shape resonances are suppressed. In contrast,...
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Methods of deep modification of low-bearing soil for the foundation of new and spare air runways
PublikacjaAfter analyzing the impact of aircraft on the airport pavement (parking spaces, runways, startways), it was considered advisable to consider the problem of deep improvement or strengthening of its subsoil. This is especially true for low-bearing soil. The paper presents a quick and effective method of strengthening the subsoil intended for the construction of engineering structures used for civil...
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Superconducting properties of vn-sio 2 sol-gel derived thin films
Publikacjain this work studies of structure and superconducting properties of vnsio2 films are reported. the films were obtained through thermal nitridation (ammonolysis) of solgel derived v2o3sio2 coatings (in a proper v2o3/sio2 ratio) at 1200 ◦c. this process leads to the formation of disordered structure with vn metallic grains dispersed in the insulating sio2 matrix. the structural transformations occurring in the lms as a result...
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Experimental analysis of wear resistance of compacts of fine-dispersed iron powder and tungsten monocarbide nanopowder produced by impulse pressing
PublikacjaThe paper presents the results of studying the structure and wear resistance of compacts produced from fine dispersed reduced iron powder (average particle size 3–mu m) with the addition of tungsten carbide (WC) nanopowder with the average particle size of 25–30 nm. The mass fraction of tungsten carbide (wolfram carbide) in the powder composition was 5% and 10% of the total mass. Impulse pressing was conducted using the modified...
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Interrelated shape memory and Payne effect in polyurethane/graphene oxide nanocomposites
PublikacjaWe report the fabrication of graphene oxide (GO) based polyurethane (PU) nanocomposites by a simple method of mixing and their shape memory properties at different temperatures. Both the polymer and the filler were synthesized in the laboratory by simple and easy methods – PU by pre-polymer method and GO by improved graphene oxide synthesis method. High molecular level dispersion of GO platelets within the PU matrix and thus good...
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Gaze tracking in multi-display environment
PublikacjaThis paper presents the basic ideas of eye and gaze tracking in multiple-display environment. The algorithm for display detection and identification is described as well as the rules for gaze interaction in multi display environment. The core of the method is to use special LED markers and eye and scene tracking glasses. Scene tracking camera registers markers position which is then represented as a cloud of points. Analyzing the...
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Structure and thermoelectric properties of bismuth telluride—Carbon composites
PublikacjaCarbon nanotubes and amorphous carbon have been introduced into a bismuth telluride matrix (0.15 and 0.30 wt.% ratio) to investigate the influence of the carbon on the composite’s thermoelectric properties. Composites with well-dispersed additives have been obtained by sonication and ball-milling methodology. Carbon nanotubes and an amorphous carbon addition led to a decrease in electric conductivity from 1120 S/cm to 77 S/cm....
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Mechanical and radiation shielding properties of concrete reinforced with boron--basalt fibers using Digital Image Correlation and X--ray micro--computed tomography
PublikacjaThe paper presents experimental investigations of the radiation shielding, mechanical and fracture properties of concrete reinforced with 5 kg/m3 of novel basalt fibers infused with boron oxide (BBF). However, further studies concerning other dosages i.e. 1 kg/m3, 10 kg/m3, 15 kg/m3 and 20 kg/m3 are currently carried out. Experiments with neutron source revealed that addition of BBF as a dispersed concrete reinforcement could improve...
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Intercultural Challenges in Virtual Teams
Publikacja: Virtual teams are usually geographically dispersed and consist of members from different countries and cultures. They influences internal communication processes and can cause personal conflicts, misunderstandings or lack of trust. Intercultural diversity is also significant for goal setting and team effectiveness. The aim of this article is to check if virtual team members appreciate the cultural diversity or rather suffer from lack...
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Materiał węglowy ptrzymany na bazie karbonizowanego chitozanu domieszkowanego platyną = CARBON MATERIAL RECEIVED THROUGH CARBONIZATION OF CHITOSAN DOPED WITH PLATINUM
PublikacjaThe aim of this work was to investigate the impact of porous carbons with high nitrogen content onthe platinum catalyst performance properties. The system may be applied as well as cathodic catalyst for oxygenreduction in microbial fuel cells.We report a simple route for preparation of dispersed Platinum on the carbon support. Chitosan powder wasprotonated using aqueous solution of organic acid. The water from the pores was removed...
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Experimental research on water lubricated marine stern tube bearings in conditions of improper lubrication and cooling causing rapid bush wear
PublikacjaWater lubricated bearings are popular in sliding bearings of marine propeller shafts, turbines and pump shafts. Such popularity is partly due to their simple construction which also means a relatively affordable price. In practical experience one may also observe cases of rapid wear or even malfunctions of this bearings, some of which may be caused by insufficient flow of lubricant leading to overheating. The conducted...
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Developing Prognostic Models of Organization Evolution
PublikacjaThe work focuses on the problem of measuring evolution of IT organizations. Changes in business influence functioning of the IT organization. IT departments or companies must ensure that the needs of their parent company/customers will be met. Therefore they must constantly evolve. Following question can be raised: is it possible to support process of changes the IT organization to run it smoother, faster, easier but with reduced...
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AN OVERVIEW OF HEAT TRANSFER ENHANCEMENT BASED UPON NANOPARTICLES INFLUENCED BY INDUCED MAGNETIC FIELD WITH SLIP CONDITION VIA FINITE ELEMENT STRATEGY
PublikacjaThe mathematical model of heat generation and dissipation during thermal energy transmission employing nanoparticles in a Newtonian medium is investigated. Dimensionless boundary layer equations with correlations for titanium dioxide, copper oxide, and aluminium oxide are solved by the finite element method. Parameters are varied to analyze their impact on the flow fields. Various numerical experiments are performed consecutively...
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Chemical structure, thermal and mechanical characterization of bio-based polyurethane composites filled with microcrystalline cellulose
PublikacjaOver the past several decades, the interest in replacing the synthetic components used in the production of polymers and composites with their natural counteparts has been growing. Biocomposites belong to the group of materials produced with the use of renewable raw materials. There has been a recent surge of interest in the industrial applications of composites containing natural fibres reinforced with biopolymers. Biopolymers...
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A Quantitative Investigation of Dislocation Density in an Al Matrix Composite Produced by a Combination of Micro-/Macro-Rolling
PublikacjaAn aluminum matrix composite with dispersed carbon nanotubes (CNTs) was produced via flake powder metallurgy using a micro-rolling process and vacuum hot pressing (VHP), followed by conventional rolling using a macro-rolling process. The microstructure and mechanical properties of the produced composites were studied. In addition, a new quantitative model was introduced to study the dislocation density based on the microstructural...
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Delivery of Ancillary Services in Distribution Power Systems
PublikacjaOne of the technical and organizational challenges the power system faces in deregulated market conditions is to organize an ancillary services market. The growing share of distributed generation of variable (intermittent) energy sources and a change in the market position of consumers, causes the demand for distributed delivery of ancillary services. For this purpose, it is sought to use the ability of the regulatory measures:...