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Search results for: CFD, CONVECTION
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Strategies for optimizing the phase correction algorithms in Nuclear Magnetic Resonance spectroscopy
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Deep Data Analysis of a Large Microarray Collection for Leukemia Biomarker Identification
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Collection Efficiency in Narrow Electrostatic Precipitators with a Longitudinal or Transverse Wire Electrode
PublicationRecently narrow electrostatic precipitators (ESPs) have become a subject of interest because of their possible application in diesel engine exhaust systems. In this work, results of particle collection efficiency measurements in narrow electrostatic precipitators for negative and positive dc voltage polarity are presented. The ESP usedin this work was a parallelepiped equipped with wire discharge electrode and two collecting plate-electrodes....
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Energy conversion in small water plants with variable speed PM generator
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Types of convictions concerning coping with pain of the participants of territory defence activities
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Collection efficiency in narrow electrostatic precipitators with a longitudinal or transverse wire electrode
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Model of the hydraulic pump powertrain of refuse collection vehicle compaction mechanism
PublicationW pracy przedstawiono symulację pracy układu napędowego pompy hydraulicznej mechanizmu prasującego śmieciarki oraz wpływ różnych konfiguracji elementów składowych tego urządzenia na zużycie paliwa silnika napędowego w warunkach przyjętego cyklu obciążenia. W tym celu wykorzystano model układu napędowego pompy hydraulicznej mechanizmu prasującego śmieciarki w formie grafów wiązań oraz wyniki pomiarów ciśnienia roboczego w siłownikach...
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Analysis and bioanalysis: an effective tool for data collection of environmental conditions and processes
PublicationReliable information that allows us to estimate the state of the environment and to forecast changes in the ecosystem are constantly required. Increasing environmental consciousness and dynamic development of analytical techniques are the main reasons for determining the wide range of pollutants occurring at very low concentrations in complex matrix samples. The presence and concentration of many of those pollutants in the environment...
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Innovative system for energy collection and management integrated within a photovoltaic module
PublicationThe dynamic development of battery technology and design based on the flow of lithium ions, mainly driven by the needs of the automotive industry, leads to the conclusion that these batteries are becoming a more viable alternative to traditional lead-acid batteries. Their use is driven by the ability to quickly charge and discharge, a higher durability, maintenance-free operation, much smaller dimensions and lighter weight. The...
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Introduction to the RSC Advances themed collection on nano and microscale modifications of biomaterials
PublicationThe dramatically increasing development of novel biomaterials, their manufacturing techniques, and surface modications, as well as their application in in vivo tests and clinical trials, is evident. It is interesting to note in what a relatively short time the well-known long-term implants have become medical standard: titanium dental implants started in 1965, and total hip arthroplasty (not very successful) was rst attempted...
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Multi-Taper-Based Automatic Correction of Non-Anechoic Antenna Measurements
PublicationPrototype measurements belong to the key steps in the development of antenna structures. Although accurate validation of their far-field performance can be realized in dedicated facilities, such as anechoic chambers, the high cost of their construction and maintenance might not be justified if the main goal of measurements is to support teaching or low-budget research. Instead, they can be performed in non-anechoic conditions and...
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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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Vapor correction of FTIR spectra – A simple automatic least squares approach
PublicationFTIR spectroscopy is one of the best techniques to study intermolecular interactions. However, such an application requires high quality spectra with as little noise as possible, which are often difficult to obtain. One of the main sources of unwanted interference is water vapor. Here a robust method is proposed for automatic, fast and reliable vapor correction of FTIR spectra. The presented least squares approach of vapor subtraction...
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Perfect thermal contact of hyperbolic conduction semispaces with an interfacial heat source
PublicationThe problem of thermal contact between two bodies with a heat source at their interface presents great scientific and practical interest. On the time scale of a nanosecond or shorter, heat propagation should be considered in the form of thermal waves of finite speeds. This study investigated the thermal behaviour of hyperbolic conduction semispaces in perfect thermal contact subjected to the action of an interfacial heat source....
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Variable Ratio Sample Rate Conversion Based on Fractional Delay Filter
PublicationIn this paper a sample rate conversion algorithm which allows for continuously changing resampling ratio has been presented. The proposed implementation is based on a variable fractional delay filter which is implemented by means of a Farrow structure. Coefficients of this structure are computed on the basis of fractional delay filters which are designed using the offset window method. The proposed approach allows us to freely...
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Application of smart glasses for fast and automatic color correction in health care
PublicationIn recent years different applications of smart glasses in health care have been proposed. In this paper we present the experiments related to automatic color correction using smart glasses platform developed within the eGlasses project. The color pattern is proposed and tested enabling the automatic detection of the pattern and automatic correction of colors. Additionally, the method for encoding and decoding of patient ID in...
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An analysis of solar energy conversion systems based on photon and thermal processes
PublicationSolar spectral irradiance covers a fairly broad wavelength range. Solar radiation is part of the electromagnetic spectrum which is described by the concept of wave-particle duality. The corpuscular theory of electromagnetic radiation states that energy is transmitted by photons. Photons carry specific amounts of energy which can be used to convert solar energy into other types of energy, in particular electricity. The internal...
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International Competitiveness of Czech Manufacturing: A Sectoral Approach with Error Correction Model
PublicationThe main objective of this paper is to find the determinants of the international competitiveness of the manufacturing sectors of the Czech economy, using the database of 13 manufacturing subsectors in 1995–2011, with the aid of ECM model. The authors research the question of how much foreign and domestic demand, the level of labour costs, the level of sector innovation intensity, the level of sector openness to foreign markets...
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Application of Web-GIS and Cloud Computing to Automatic Satellite Image Correction
PublicationRadiometric calibration of satellite imagery requires coupling of atmospheric and topographic parameters, which constitutes serious computational problems in particular in complex geographical terrain. Successful application of topographic normalization algorithms for calibration purposes requires integration of several types of high-resolution geographic datasets and their processing in a common context. This paper presents the...
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ENERGY EFFICIENT AND ENVIRONMENTALLY FRIENDLY HYBRID CONVERSION OF INLAND PASSENGER VESSEL
PublicationThe development and growing availability of modern technologies, along with more and more severe environment protection standards which frequently take a form of legal regulations, are the reason why attempts are made to find a quiet and economical propulsion system not only for newly built watercraft units, but also for modernised ones. Correct selection of the propulsion and supply system for a given vessel affects significantly...
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Rapid dimension scaling of compact microwave couplers with power split correction
PublicationIn this paper, a technique for rapid re-design ofcompact microwave couplers with respect to operating frequency is discussed. Our methodology involves an inverse surrogate model setup using several reference designs optimized (at the level of equivalent circuit representation of the coupler) for a set of operating frequencies within a range of interest. The surrogate establishes the relationship between the operating frequency...
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Enhanced energy conversion as a result of fluid-solid interaction in micro- and nanoscale
PublicationIt is known that nano- and micromechanics require new approaches to right describing of surface-like phenomena which lead to an enhanced energy conversion. In this work, a general form of surface forces that consist of a contribution from both the friction and mobility components has been extended to collect the effects of bulk and surface motion of a fluid. Quite similar impact can be observed for a solid-fluid mixture, where...
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Empirical Relationship Describing Total Convective and Radiative Heat Loss in Buildings
PublicationOn the basis of theoretical considerations of convective-radiative heat transfer, a relationship was developed enabling the total convective and radiative heat flux QC+R emitted from any object at tw and its surroundings at t∞ to be calculated from known values of the surface temperature of such an object, i.e., the known temperature difference Δt=tw - t∞ and average air temperature Tav. This relationship is applied to thermal...
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Natural convective heat-transfers from an isothermal horizontal hemispherical cavity
PublicationPrzedstawiono rozwiązanie analityczne oraz wyniki badań eksperymentalnych i numerycznych konwekcyjnej wymiany ciepła od poziomej izotermicznej kulistej wklęsłej powierzchni.
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A theoretical consideration of a free convective boundary layer on an isothermal horizontal conic.
PublicationPrzedstawiono rozwiązanie analityczne naturalnej konwekcji swobodnej od izotermicznego, poziomego stożka o kącie przy podstawie alfa. Rozwiązanie przeprowadzono w oparciu o typowe dla konwekcji swobodnej założenia upraszczające. Rozwiązania dla przypadków granicznych (poziomy walec i pionowa płyta kołowa) wykazują dobrą zgodność z danymi literaturowymi.
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Some aspects of vibration control. Part I: Active and passive correction.
PublicationPrzedstawiono ogólne podejście do modyfikacji układu mechanicznego w ruchu harmonicznym przy użyciu aktywnych i pasywnych metod. Zaproponowano metodę wyznaczania elementów macierzy układu lub struktury i nastaw regulatora, zapewniającą najefektywniejsze oddziaływanie na dynamikę ruchu.
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Experimental research on over-laminated steel sandwich panel connection to determine the form of fatigue failure
PublicationThe novel means of transport need to meet rising both the economic and ecologic requirements. In recent years the International Maritime Organization (IMO) introduced new measure of ship energy efficiency (the EEDI index), as well as new regulations regarding higher quality of fuel (so called Tier limits). It resulted in much higher interest of the technological development of ships. One of the solution having great potential is...
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Results from tests on bolted connection components for evaluation of friction coefficient in various contact conditions
PublicationThe main purpose of the work was the analysis and evaluation of the self-locking quality of a bolted joint covered with Xylan 1070 coating, with comparison to the classic bolts lubricated with Molykote compound during assembly. The second part of the work was the verification of the compliance of the bolts and nuts used in the installation with the ASME B1.1 norm.
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A Model of Thermal Energy Storage According to the Convention of Bond Graphs (BG) and State Equations (SE)
PublicationThe main advantage of the use of the Bond Graphs method and State Equations for modeling energy systems with a complex structure (marine power plants, hybrid vehicles, etc.) is the ability to model the system components of different physical nature using identical theoretical basis. The paper presents a method of modeling thermal energy storage, which is in line with basic BG theory. Critical comments have been put forward concerning...
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A Novel Coupling Matrix Synthesis Technique for Generalized Chebyshev Filters With Resonant Source–Load Connection
PublicationThis paper reports a novel synthesis method for microwave bandpass filters with resonant source–load connection. In effect, a network realizing N+1 transmission zeros (where N is the number of reflection zeros) is obtained. The method is based on a prototype transversal coupling matrix (N+2, N+2) with source and load connected by a resonant circuit formed by a capacitor in parallel with a frequency-invariant susceptance. To complement...
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THE MANAGEMENT OF DESIGNING PROCESSES IN THE CREATION OF THE KNOWLEDGE BASE SYSTEM : Proceedings of International Computer Science Convention
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Cattaneo–Christov heat flow model for copper–water nanofluid heat transfer under Marangoni convection and slip conditions
PublicationThis report is devoted to the study of the flow of MHD nanofluids through a vertical porous plate with a temperature-dependent surface tension using the Cattaneo–Christov heat flow model. The energy equation was formulated using the Cattaneo–Christov heat flux model instead of Fourier’s law of heat conduction. The Tiwari–Das model was used to take into account the concentration of nanoparticles when constructing the momentum equation....
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On the modelling of anisotropy and destructuration of soft clays within the multi-laminate framework.
PublicationZaproponowano nowy model konstytutywny dla słabonośnych gruntów drobnoziarnistych, w którym anizotropię cech wytrzymałościowych połączono ze zmianami struktury szkieletu gruntowego. Model ten został sformułowany w ramach tzw. modeli wielopłaszczyznowych (multi-laminate) bazujących na teorii sprężysto-plastyczności. Przedstawiono praktyczne zastosowanie modelu do obliczeń nasypu drogowego na podłożu słabonośnym metodą elementów...
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Hydraulic fracturing process in rocks – small-scale simulations with a novel fully coupled DEM/CFD-based thermo-hydro-mechanical approach
PublicationW artykule przedstawiono dwuwymiarową (2D) symulację numeryczną szczelinowania hydraulicznego w małej skali przeprowadzoną w próbkach skał posiadających pojedynczą szczelinę wtryskową. Wykorzystano unikalny model termo-hydro-mechaniczny (THM) w skali porów oparty na DEM/CFD do symulacji dwufazowego laminarnego przepływu płynu (wody i gazu) z przenoszeniem ciepła w nienasyconych materiałach porowatych o niskiej porowatości. Korzystając...
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Modelling of Hydraulic Fracturing in Rocks in Non-isothermal Conditions Using Coupled DEM/CFD Approach with Two-Phase Fluid Flow Model
PublicationSkała łupkowa jest materiałem silnie niejednorodnym, nieciągłym i porowatym. W warunkach nieizotermicznych ruch płynu w układzie porów i kapilar jest silnie sprzężony z przenoszeniem ciepła. Przebieg szczeliny hydraulicznej silnie zależy od stopnia nasycenia skały. Opracowano innowacyjny model termo-hydro-mechaniczny oparty na modelu DEM w celu szczegółowego śledzenia frakcji ciecz/gaz w porach i pęknięciach pod kątem ich różnej...
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Modelling hydraulic and capillary-driven two-phase fluid flow in unsaturated concretes at the meso-scale with a unique coupled DEM-CFD technique
PublicationThe goal of the research was to demonstrate the impact of thin porous interfacial transition zones (ITZs) between aggregates and cement matrix on fluid flow in unsaturated concrete caused by hydraulic/capillary pressure. To demonstrate this impact, a novel coupled approach to simulate the two-phase (water and moist air) flow of hydraulically and capillary-driven fluid in unsaturated concrete was developed. By merging the discrete...
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Development of Microstructured Carbon Coatings by Substrate-Catalytic CVD
PublicationCarbon nanostructured films were synthesized by chemical vapor deposition (CVD) on H18 stainless steel (AISI 440C) sheets with an H2/CH4/N2 gas mixture at various substrate temperatures. During the synthesis, the iron and chromium oxide layer was formed between the steel and carbonaceous layer. The carbon films exhibited wall-like and spherical morphologies and structures, as characterized by scanning electron microscopy and Raman...
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Experimental investigation of joint with positive eccentricity in CFS truss
PublicationDue to technological restrictions, in the case of trusses made of CFS open cross-sections, positive eccentricities in the truss joints have become very frequent. Therefore studies concerning the load-bearing capacity of truss joints with positive eccentricity were undertaken. It was assumed that the resistance of cold-formed steel (CFS) open cross-section truss joints located on compression chords and with positive eccentricity...
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Surrogate models and automated cad of passive microwave components
PublicationW pracy pokazane zostały techniki modelowania złożonych układów elektronicznych wysokiej częstotliwości. Modele zastępcze mają postać sparametryzowanych modeli matematycznych tworzonych za pomocą schematów interpolacyjnych lub skupionych, pasywnych układów zastępczych dedykowanych analizie w dziedzinie czasu. Do konstrukcji modeli wykorzystywane są wyniki symulacji elektromagnetycznych, co pozwala na osiągnięcie lepszej dokładności...
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System optoelektroniczny do kontroli procesów μPA CVD
PublicationPrzedstawiono prototyp optoelektronicznego systemu do monitorowania in-situ procesu CVD, wspomaganych plazmą mikrofalową. System składa się z układu optycznej spektroskopii emisyjnej OES oraz specjalizowanego spektroskopu ramanowskiego RS. Umożliwia on równoczesne monitorowanie składu plazmy oraz określanie dynamiki wzrostu i zawartości defektów warstwy. Przedstawiono wyniki badań przebiegu procesu wytwarzania warstw diamentopodobnych...
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Quadratic programming approach to coupled resonator filter cad
PublicationArtykuł prezentuje technikę komputerowego wspomagania procesu projektowania filtrów zbliżeniowych. Polega ona na sformułowaniu macierzy sprzężeń jako problemu programowania kwadratowego (QP). Dzięki zdefiniowaniu procedury optymalizacyjnej jako problemu QP, przy założeniu liniowej zależności współczynników sprzężeń od wymiarów geometrycznych struktury, uzyskano znaczącą redukcję liczby pełnofalowych symulacji prowadzących do uzyskania...
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CVD generated mesoporous hollow carbon spheres as supercapacitors
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Development of low noise CCD readout front-end
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Development of low noise CCD readout front-end
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Projektowanie filtru DFT-VFD metodą Hooke-Jeevesa
PublicationZaletą filtrów ułamkowo opóźniających typu DFT-VFD określanych przez współczynniki ich dyskretnej charakterystyki częstotliwościowej z pasma przejściowego jest ich powiązanie z metodą okien przesuwanych. Czyni je to szczególnie przydatnymi w zastosowaniach do zmiany szybkości próbkowania. Problem stanowi jednak projektowanie tych filtrów. Dotychczas dostępna metoda POCS co prawda gwarantuje zbieżność, ale jest ona bardzo powolna....
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Thin CVD diamond films - synthesis, properties, applications
PublicationThe basic model of diamond films growth, in the low pressure synthesis, deposition from the CVD gas phase, is the mixture of hydrocarbon gas in presence with activated hydrogen and its nucleation on the substrate as a result of pyrolysis reaction. It allows to cross the great energetic barrier between graphite and diamond. High pressure and temperature are replaced by change of electronic structure of atoms into gas precursors...
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TECHNIKI CAD W INŻYNIERII ELEKTRYCZNEJ - WYBRANE ZAGADNIENIA
PublicationW pracy przedstawiono różne techniki CAD (ang. Computer Aided Design) wykorzystywane w inżynierii elektrycznej dla potrzeb komputerowego modelowania 3D przetworników elektromechanicznych. Wirtualne modele 3D różnych urządzeń są użyteczne nie tylko przy opracowywaniu dokumentacji technicznej ale są także wykorzystywane w obliczeniach inżynierskich:...
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Diagnostics of cvd process by means of optical emission spectroscopy.
PublicationZastosowano optyczną spektroskopię emisyjną do badania w trybie in-situ dysocjacji cząsteczek oraz wzbudzenia i jonizacji atomów wodoru podczas procesu syntezy cienkich warstw diamentowych metodą chemicznego osadzania z par gazowych wspomaganego plazmą mikrofalową (mPACVD). Zbudowano tor światłodowy, umożliwiający sprzężenie komory CVD z systemem spektroskopowym i wykonywanie pomiarów bezinwazyjnych. Wykonano pomiary spektralne...
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Internet as a new platform for delivery of microwave CAD services.
PublicationZaprezentowano aplikację przeznaczoną do syntezy filtrów rezonatorowych, która jest realizacją nowego sposobu myślenia związanego z rewolucją usług internetowych, które charakteryzują się niskim kosztem tworzenia oraz szybką i bezpieczną dystrybucją. Opisano stworzoną wielowarstwową aplikację, która gwarantuje łatwy, bezpieczny oraz ograniczony dostęp do aplikacji dla szerokiego kręgu osób. Zawarto w niej algorytm szybkiej syntezy...
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Characteristics of the Radunia river and its catchment in view of WFD
PublicationCelem Ramowej Dyrektywy Wodnej (RDW), między innymi problemami jest ochrona śródlądowych wód powierzchniowych, zabezpieczenie przed dalszym pogorszenien ich stanu i poprawa stanu ekosystemów wodnych. Badania Rzeki Raduni i jej zlewni zostały wykonane przez Instytut Budownictwa Wodnego i Politechnikę Gdańską. Dotyczyły one wód śródlądowych (rzeki, jeziora, zbiorniki), ich hydrologii, hydrauliki i jakości wody. Rzeka jest istotna...