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Search results for: multi-phase flows
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Global EM-Driven Optimization of Multi-Band Antennas Using Knowledge-Based Inverse Response-Feature Surrogates
PublicationElectromagnetic simulation tools have been playing an increasing role in the design of contemporary antenna structures. The employment of electromagnetic analysis ensures reliability of evaluating antenna characteristics but also incurs considerable computational expenses whenever massive simulations are involved (e.g., parametric optimization, uncertainty quantification). This high cost is the most serious bottleneck of simulation-driven...
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Modeling two phase flow in large scale fractured porous media with an extended multiple interacting continua method
PublicationWe present a two phase flow conceptual model, the corresponding simulator (2pMINC) and a workflow for large-scale fractured reservoirs, based on a continuum fracture approach which uses the multiple interacting continua (MINC) method complemented with an improved upscaling technique. The complex transient behavior of the flow processes in fractured porous media is captured by subgridding the coarse blocks in nested volume elements...
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Simultaneous Determination of Indolic Compounds in Plant Extracts by Solid-Phase Extraction and High-Performance Liquid Chromatography with UV and Fluorescence Detection
PublicationA high-performance liquid chromatographic method with UV and fluorescence detection (HPLC-DAD-FLD) was developed for simultaneous determination of indolic compounds in plant material. Indole-3-carbinol (I3C), indole-3-acetic acid (I3AA), indole-3-acetonitrile (I3ACN), and 3,3′-diindolylmethane (DIM) were used as representative compounds that cover a wide spectrum of indole structures occurring in nature. For concentration and purification...
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A negative effect of carbon phase on specific capacity of electrode material consisted of nanosized bismuth vanadate embedded in carbonaceous matrix
PublicationLithium-ion batteries (LIBs) are widely used all over the world. The LIBs belong to a renewable energy source and energy storage devices. The increase in energy demand causes that new materials of higher energy and higher power densities are still under investigation. Herein, we compare electrochemical properties of bismuth vanadate (BiVO4) embedded and not embedded into carbonaceous matrix as an anode material along with structural...
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Induction of G2/M phase arrest and apoptosis of human pancreatic cancer BxPC-3 cells by potenet antitumor 1-nitroacridine derivative C-1748
PublicationPancreatic ductal adenocarcinoma (PDA) is among the most lethal human cancers, in part because it is insensitive to many chemotherapeutic drugs. Gemcitabine still remains the best chemotherapeutic agent available for the treatment of advanced pancreatic cancer. However, gemcitabine treatment results in only a marginal survival advantage. Thus, there is a strong need for the continuous development of novel therapeutic agents...
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Bandwidth-size design trade-offs for compact spline-parameterised patch couplers by means of electromagnetic-driven multi-objective optimisation
PublicationBroad bandwidth and small size are the key performance figures for contemporary microwave couplers. These requirements are conflicting, i.e. improvement of one generally leads to degradation of the other assuming fixed topology of the circuit at hand. From a designer's perspective, the knowledge about available design trade-offs is indispensable as it permits for tailoring the circuit for particular applications as well as comparing...
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Approximation of Message Inter-Arrival and Inter-Departure Time Distributions in IMS/NGN Architecture Using Phase-Type Distributions
PublicationCurrently it is assumed that requirements of the information society for delivering multimedia services will be satisfied by the Next Generation Network (NGN) architecture, which includes elements of the IP Multimedia Subsystem (IMS) solution. In order to guarantee Quality of Service (QoS), NGN has to be appropriately designed and dimensioned. Therefore, proper traffic models should be proposed and applied. This requires determination...
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Method of earth fault loop impedance measurement without nuisance tripping of RCDs in 3-phase low-voltage circuits
PublicationVerification of electrical safety in low-voltage power systems includes the measurement of earth fault loop impedance. This measurement is performed to verify the effectiveness of protection against indirect contact. The widespread classic methods and meters use a relatively high value of the measuring current (5–20) A, so that they are a source of nuisance tripping of residual current devices (RCDs). The meters dedicated to circuits...
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MULTI-CRITERIA INVESTMENT DECISION SUPPORT MODEL USING FUZZY ANALYTIC HIERARCHY PROCESS (F-AHP) METHOD FOR POWER INDUSTRY
PublicationIn this paper, the comparative analysis of two wind farm construction projects was presented. This particular type of analysis is commonly applied before purchasing investment project being in a planning phase by a company interested in its development. Conduction of this type of analysis is prompted by the necessity to take into consideration the requirements of Polish legislation. Comparison of wind farm construction projects...
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Solid Phase Micro-Extraction, a Versatile and Handy Tool in Environmental Trace Organic Analysis, Gets a New Class of Coatings, Polymeric Ionic Liquids
PublicationSolid phase microextraction (SPME) fundamentals, characteristics and application are described. The special stress is put on characteristics of sorbents used as SPME fiber coatings. Description of commercially available fibers and the present-day trends in development of new sorbents for SPME are given. Discussion is focused on possibility of application of ionic liquids (IL) and polymeric ionic liquids (PIL) as SPME fiber coatings....
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Determination of antifreeze substances in the airport runoff waters by solid-phase microextraction and gas chromatography–mass spectrometry method
PublicationA new method has been developed for the determination of antifreeze agents such as ethylene glycol (EG), propylene glycol (PG), and diethylene glycol (DEG) in the samples of airport runoff water. The method is based on headspace solid–phase microextraction (HS–SPME) of target analytes, which is coupled with gas chromatography–mass spectrometry (GC–MS). Until now, there was a lack of appropriate methodology for collecting reliable...
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Tuning the extraction properties of ionogel-coated Solid-phase microextraction fibers based on the solvation properties of the ionic liquids
PublicationA silica-based network was used to immobilize ionic liquid-based ionogels and applied as a fiber coating forsolid-phase microextraction (SPME). The ionogels were prepared by a sol–gel process, using two ionic liquids,triethylsulfonium bis(trifluoromethylsulfonyl)imide ([Set3][TFSI]) and 1-butyl-1-methylpiperidinium bis(tri-fluoromethylsulfonyl)imide ([C4C1Pip][TFSI]), as well as their equimolar mixture. Methyltrimethoxysilane wasused...
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A Comparative Quantitative Structure-Retention Relationships Study for Lipophilicity Determination of Compounds with a Phenanthrene Skeleton on Cyano-, Reversed Phase-, and Normal Phase-Thin Layer Chromatography Stationary Phases
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Application of response surface methodology to optimize solid-phase microextraction procedure for chromatographic determination of aroma-active monoterpenes in berries
PublicationMost of scientific papers concern the qualitative or semi-quantitative analysis of aroma-active terpenes in liquid food matrices. Therefore, the procedure based on solid-phase microextraction and comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry for determination of monoterpenes in fresh berries was developed. The optimal extraction conditions using divinylbenzene-carboxen-polydimethylsiloxane fiber...
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NUMERICAL ANALYSIS OF SPECIES DIFFUSION AND METHANOL DECOMPOSITION IN THERMOCATALYTIC REACTOR BASED ON THE INTERMETALLIC PHASE OF Ni3Al FOR LOW REYNOLDS NUMBERS
PublicationNumerical modelling of hydrogen production by means of methanol decomposition in a thermocatalytic reactor using corrugated foil made of the Ni3Al intermetallic phase is shown in the paper. Experimental results of the flow analysis of mixtures containing helium and methanol in a thermocatalytic reactor with microchannels were used for the initial calibration of the CFD calculations (calculations based on the Computational Fluid...
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Jacek Tejchman prof. dr hab. inż.
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Single-phase power electronics transformer with active functions for smart grid
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Strategies for optimizing the phase correction algorithms in Nuclear Magnetic Resonance spectroscopy
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The role of intermolecular interactions in stabilizing the structure of the nematic twist-bend phase
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Thermotropic Biaxial Nematic Phase in Liquid Crystalline Organo-Siloxane Tetrapodes
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Dissociative electron attachment to gas phase thiothymine: experimental and theoretical approaches
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Stability of liquid film formed due to impingement of a two-phase jet
PublicationPrzedstawiono analizę teoretyczną i badania eksperymentalne zjawiska rozrywania się warstwy cieczy powstałej na powierzchni ciała stałego z uderzającej strugi.
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Composite Bioelectrodes Based on Lipidic Cubic Phase with Carbon Nanotube Network
PublicationElektrody z węgla szklistego modyfikowane fazą kubiczną z siecią nanorurek zastosowano do enzymatycznej redukcji tlenu katalizowanej przez lakazę. Zastosowanie nanorurek obniżyło nadpotencjał redukcji tlenu o 0,5 V. W celu zwiększenia gęstości prądu redukcji tlenu zastosowano znany mediator przeniesienia elektronów - ABTS. Mediator adsorbowano na nanorurkach lub wiązano kowalencyjnie z końcami nanorurek. Kowalencyjne związanie...
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Mechanism of a Four-Phase Liquid Membrane Oscillator Containing Hexadecyltrimethylammonium Bromide
PublicationBadano zachowanie nitrometanowego oscylatora z membraną ciekłą zawierającego kationowy surfaktant. Początkowo układ składał się z trzech faz: wodnej donorowej zawierającej surfaktant i etanol, membrany ciekłej (kwas pikrynowy w nitrometanie) oraz fazy wodnej akceptorowej zawierającej sacharozę. Podczas procesu oscylacyjnego wytwarzała się nowa fazą X między membraną ciekłą, a fazą akceptorową. Stwierdzono oscylacje różnicy potencjału...
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Simulation and Experiment of a Compact Wideband 90^{circ} Differential Phase Shifter
PublicationArtykuł przedstawia projekt i analizę kompaktowego różnicowego przesuwnika fazy, który jest rozwinięciem konfiguracji zaproponowanej Abbosha poprzez modyfikację obciążenia wrót. Zaproponowana konfiguracja zawiera 3dB sprzęgacz kierunkowy z wrotami transmisyjnymi i sprzężonymi zakończonymi obciążeniami reaktancyjnymi. W artykule przedstawiono model teoretyczny prezentujący zasadę działania układu i jego projekt. Uzyskane wyniki...
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Solid phase extraction of explosives on Ni-doped carbosils prepared by mechanochemistry
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Losses Model of the WPT System with Single-Phase T-Type Inverter
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Riboflavin binding protein—Chiral stationary phase: Investigation of retention mechanism
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Pressure-induced phase transition in LiLuF4:Pr3+investigated by an optical technique
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Optical processes in YVO4:Eu3+across zircon-to-scheelite phase transition
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Recognition of two-phase flow patterns with the use of dynamic image analysis
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Two-phase flow structure assessment based on dynamic image analysis
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Ag/Pt-modified TiO2 nanoparticles for toluene photooxidation in the gas phase
PublicationAg/Pt-modified TiO2nanocomposites were synthesized using the sol–gel method. The effect of metal typeand amount as well as synthesis route on the photocatalytic activity in reaction of toluene removal, usedas a model volatile organic compound, was investigated. Toluene, at the concentration of about 200 ppm,was irradiated over modified TiO2using light-emitting diodes (LEDs, max= 415 nm). The results showedthat toluene could be...
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A review of theoretical and practical aspects of solid-phase microextraction in food analysis.
PublicationSPME (mikroekstrakcja do fazy stacjonarnej) to szybka, nowoczesna technika przygotowania próbki do analizy. W niniejszej pracy dokonano przeglądu zastosowania techniki SPME do badania zanieczyszczeń żywności i analizy jej naturalnych składników. Praca zawiera również krótki teoretyczny opis zasad działania techniki SPME.
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Phase compensation scheme for feedforward linearised CMOS operational transconductance amplifier.
PublicationW pracy opisano technikę kompensacji charakterystyk fazowych linearyzowanego metodą feedforward operacyjnego wzmacniacza transkonduktancyjnego CMOS. Wykazano, że proponowana koncepcja układowa prowadzi do znacznej poprawy liniowości charakterystyki przejściowej wzmacniacza oraz do rozszerzenia zakresu liniowości prądu wyjściowego. Ponadto w pracy przeprowadzono analizę charakterystyk częstotliwościowych, w wyniku której otrzymano...
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Experimental and comparative study on the two-phase pressure drop of air-water mixture in U-bend and straight pipe annuli
PublicationIn this paper, the experimental and theoretical analysis of pressure drop in singlephase and two phase-flow were presented for straight and U-bend smooth tube annulus and tube annulus with wire coil insert. Experiments for various boundary conditions were performed. In case of U-tube and straight tube with and without turbulator, tests were made for the water-water and air-water systems. The study covered a wide measuring range,...
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Monolithic capsule phase microextraction prior to gas chromatography-mass spectrometry for the determination of organochlorine pesticides in environmental water samples
PublicationIn this study, a capsule phase microextraction (CPME) protocol followed by gas chromatography-mass spectrometry is proposed for the accurate and sensitive monitoring of organochlorine pesticides (OCPs) in environmental water samples. Different monolithic sol–gel encapsulated sorbents were compared and monolithic sol–gel poly(ethylene glycol)-based sorbent incorporated into porous microextraction capsules resulted in the highest...
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CDKN2A common variant and multi-organ cancer risk—a population-based study
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A European Multi Lake Survey dataset of environmental variables, phytoplankton pigments and cyanotoxins
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Multi-Label Classification for AIS Data Anomaly Detection Using Wavelet Transform
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Dynamic Analysis of an Enhanced Multi-Frequency Inertial Exciter for Industrial Vibrating Machines
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A Multi Rig Screening Test for Thin Ceramic Coatings in Bio - Tribological Applications
PublicationA method is presented for the comparative testing of wear resistance of ceramic coatings made from materials potentially feasible in tribo - medical applications, mainly orthopaedic implants made from ceramics coated metals for low cost, long life and low wear particle emission into the body. The method was devised as the main tool for use in research and is comprised of flat on flat and ball on flat surface (sliding) tests. Seven...
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Makespan minimization of multi-slot just-in-time scheduling on single and parallel machines
PublicationArtykuł podejmuje problem szeregowania zadań przy założeniu podziału czasu na sloty jednakowej długości, gdzie każde z zadań ma ustaloną długość oraz czas jego zakończenia, który jest relatywny do końca slotu. Problem znalezienia uszeregowania polega na dokonaniu przydziału zadań do poszczególnych slotów, przy czym w ogólności długość zadania może wymuszać sytuację, w której zadańie jest realizowane nie tylko w slocie, w którym...
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Coordination of generator transformer controller and multi-parameter generator controller regulation algotrithms
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WiMA: Towards a Multi-Criterion Association in Software Defined Wi-Fi Networks
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Conditional Value-at-Risk Vs. Value-at-Risk to Multi-Objective Portfolio Optimization
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Lexicographic and weighting approach to multi-criteria portfolio optimization by mixed integer programming
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How should we teach cardiopulmonary resuscitation? Randomized multi-center study
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Integration of multi-interface conversion channel using FPGA for modular photonic network
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Elastic and inelastic multi-storey buildings under earthquake excitation with the effect of pounding
PublicationW artykule przeprowadzono analizę różnic w liniowym i nieliniowym zachowaniu się budynków wielokondygnacyjnych podczas trzęsień ziemi z uwzględnieniem efektu zderzeń pomiędzy nimi. Analizę numeryczną przeprowadzono dla różnych wartości ekstremalnych przyspieszeń gruntu. Wyniki pokazują, iż zaimplementowanie nieliniowego modelu zachowania się budowli jest bardzo istotne w celu uzyskania dokładnej odpowiedzi konstrukcji.