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Wyniki wyszukiwania dla: SLE phase diagrams
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New achievements in the field of extraction of trace analytes from samples characterized by complex composition of the matrix
PublikacjaWithout any doubt, the monitoring of compounds present in samples at trace or ultra-trace level usually requires a preliminary step of isolation and/or enrichment of analytes due to the fact that majority of analytical techniques are not sensitive enough for direct determination of trace compounds. On the other hand, sample preparation is considered as crucial part of whole analytical procedures, in particular in samples characterized...
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A semi-empirical model for flow boiling heat transfer with account of the reduced pressure effect
PublikacjaIn the present study the attention was focused on the influence of reduced pressure on the predictions of heat transfer during flow boiling at the extensive range of pressures. The results of calculations were to test the sensitivity of the in-house flow boiling model with respect to the selection of the appropriate two-phase flow multiplier, which is one of the distinctive elements of that model. For this purpose a few two-phase...
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Canonical switched capacitor converters. Comments, complements, and refinements
PublikacjaSwitched Capacitor Converters (SCC) form useful blocks in low/medium power applications as they are suitable for integration, both as off-chip and on-chip IC realizations. However, the problem with SCC is that their voltage conversion ratio is topology-dependent. By changing the SC circuit configuration, we can gain control over voltage conversion but the available ratio remains of a discrete nature, i.e. it maps into a countable...
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Electronic and ionic relaxations in strontium-borate glass and glass-ceramics containing bismuth and vanadium oxides
PublikacjaThe topography, microstructure and electrical properties of strontium-borate glass and SBO glass containing bismuth and vanadium oxides, were studied. The structure was measured using X-ray diffraction (XRD), Energy Dispersive X-ray Spectrometer (EDS) and Scanning electron microscope (SEM) methods. The A.C. complex conductivity was investigated as a function of temperature and frequency. The influence of the quantity of bismuth...
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The potential of enhancing denitrification in the activated sludge process with by-products from the alcohol production
PublikacjaIn this study, by-products from the alcohol production were examined in terms of their potential application as external carbon sources for enhancing denitrification in biological nutrient removal systems. Three kinds of experimental assays were used to compare the effects of the by-products with other external carbon sources (ethanol and acetic acid) and the settled wastewater. Based on the results obtained, it appears that one...
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Current Source Inverter Fed Drive
PublikacjaThis book covers three-phase and multiphase (more than three-phase) motor drives including their control and practical problems faced in the field (e.g., adding LC filters in the output of a feeding converter), are considered. The new edition contains links to Matlab®/Simulink models and PowerPoint slides ideal for teaching and understanding the material contained within the book. Readers will also benefit from the inclusion of: A...
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Optimisation of turbine shaft heating process under steam turbine run-up conditions
PublikacjaAn important operational task for thermal turbines during run-up and run-down is to keep the stresses in the structural elements at a right level. This applies not only to their instantaneous values, but also to the impact of them on the engine lifetime. The turbine shaft is a particularly important element. The distribution of stresses depends on geometric characteristics of the shaft and its specific locations. This means a groove manufactured...
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Study of oxygen electrode reactions on symmetrical porous SrTi0.30Fe0.70O3-δ electrodes on Ce0.8Gd0.2O1.9 electrolyte at 800 °C–500 °C
PublikacjaIron doped strontium titanates (SrTi1-xFexO3-δ) are an interesting mixed ionic-electronic conductor model used to study basic oxygen reduction/oxidation reactions. In this work, we performed an impedance spectroscopy study on symmetrical porous SrTi0.30Fe0.70O3-δ (STF70) electrodes on a ceriabased electrolyte. The sample was measured in varying oxygen concentration: from 0.3% to 100% in 800 °C - 500 °C temperature range. Low polarisation...
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MnxCo3-xO4 spinel oxides as efficient oxygen evolution reaction catalysts in alkaline media
PublikacjaThe design of efficient electrocatalysts for oxygen evolution reaction (OER) is an essential task in developing sustainable water splitting technology for the production of hydrogen. In this work, manganese cobalt spinel oxides with a general formula of MnxCo3-xO4 (x=0, 0.5, 1, 1.5, 2) were synthesised via a soft chemistry method. Non-equilibrium mixed powder compositions were produced, resulting in high electrocatalytic activity....
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Simplified Approach for Broadband RF Testing of Low Loss Magneto-Dielectric Samples
PublikacjaIn this paper, an attractive measurement techniqueis proposed to retrieve the broadband permittivity and permeabil-ity of the magneto-dielectric materials. The proposed techniqueis quite novel which mitigates the major problems associatedwith the conventional broadband RF material characterizationtechniques such as numerical instability and phase uncertaintywhen the length of the sample exceeds...
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Modelling of heat transfer in supercritical pressure recuperators
PublikacjaIn the paper presented is analysis of convective flow heat transfer at supercritical pressure in channels of heat exchanger working in the thermodynamic cycle. The modelling is based on the division of the flow into three regions, namely the heavy fluid, a two phase flow consisting of the heavy and light fluids and finally the light fluid flow. Modelling is concentrated on the region of simultaneous flow of two fluids divided into...
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RF Multi-Functional Input-Reflectionless Dispersive-Delay Structure With Sharp-Rejection Filtering Using Channelization Techniques
PublikacjaA class of RF multi-functional input-reflectionless dispersive-delay structure (DDS) with linear-type in-band groupdelay variation and sharp-rejection bandpass-filtering capability is reported. It exploits a two-branch-channelized/balanced-type circuit with similar low-order reflective DDS units inside its channels, which are connected through input/output 3-dB quadrature wideband couplers. The adopted DDS unit is based on a coupledresonator...
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Spinning Fluids Reactor: A new design of a gas – liquid contactor
PublikacjaCurrent trends in chemical reactor design are based on adapting these to the requirements of a particular chemical process. Processes involving reactions between the gas and liquid phase in particular require precise adjustment of all parameters. The common denominator for most modern design solutions is enhancement of the mass transfer area and the overall volumetric mass transfer coefficient. Gas – liquid contactors evolved from...
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Assessment of Lipophilicity Indices Derived from Retention Behavior of Antioxidant Compounds in RP-HPLC
PublikacjaReverse phase high pressure liquid chromatography was employed in order to evaluate the lipophilicity of antioxidant compounds from different classes, such as phenolic acids, flavanones, flavanols, flavones, anthocyanins, stilbenes, xantonoids, and proanthocyanidins. The retention time of each compound was measured using five different HPLC columns: RP18 (LiChroCART, Purosphere RP-18e), C8 (Zorbax, Eclipse XDBC8), C16-Amide (Discovery...
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STRUKTURA SZKŁO-CERAMIKI ZAWIERAJĄCEJ FERROELEKTRYCZNĄ FAZĘ BiV
PublikacjaLiteratura opiusuje próby wytworzenia nanokompozytów, w których skład wchodzą matryca szkła i rozproszone w niej nanokrystality fazy ferroelektrycznej. Najczęstsza metoda wykorzystywana do otrzymywania takiej szkło - ceramiki polega na wytopie szkła, a następnie jego krystalizacji. W literaturze można znaleźć dużo przykładów wytwarzania tego typu materiałów dwu lub więcej składnikowych. Najwięcej badań dotyczy ferroelektrycznych...
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Przekształtniki tranzystorowe działające w trybie prądu trójkątnego
PublikacjaPrzekształtniki oparte na węgliku krzemu mogą być analizowane jako źródła napięcia lub prądu niezależnie od topologii przy odpowiednich parametrach filtru wyjściowego. Szczególnie interesujące są falowniki napięcia działające w trybie prądu trójkątnego. W referacie przedstawiono sterowanie trójfazowym falownikiem napięcia posiadającym właściwości źródła prądu. Pokazano, jak dobrać parametry filtru wyjściowego falownika. Oceniono...
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Comprehensive two-dimensional gas chromatography and three-dimensional fluorometry for detection of volatile and bioactive substances in some berries
PublikacjaThe volatilefractionsofCapegooseberryandblueberryweredeterminedbyheadspacesolid-phase microextractioncoupledwithcomprehensivetwo-dimensionalgaschromatographywithtime-of-flight mass spectrometry(HS-SPME/GCGC-TOFMS).Thehighestamountofalcohol(51.8%),ester(32.8%)and carboxylicacid(6.9%)wasinblueberryincomparisonwithgooseberryandoppositelyketones(14.7%), aldehydes(9.9%)andterpenes(8%)werefoundingooseberry.Thebioactivecompoundsandantioxidant capacities...
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Chemiresistive gas sensors based on carbon nanotubes - fabrication and application
PublikacjaMany types of sensors have been invented to identify and quantify chemical contamination in the gas phase. Sensors based on carbon nanotubes are particularly attractive because of their wide range of applicaions and potential use in electronic nose that can be controlled using algorithms of Artificial Intelligence. Sensor functions, fabrication and selected applications are reviewed and discussed with focus on chemiresistors. Drawbacks...
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Asfalteny jako fazy stacjonarne w chromatografii cieczowej w normalnych układach faz
PublikacjaRozprawa doktorska dotyczy zbadania możliwości wykorzystania asfaltenów wydzielonych z: próżniowej pozostałości ropy naftowej, produktów jej utleniania i naturalnego asfaltu jako fazy stacjonarnej na powierzchni sorpcyjnej żelu krzemionkowego do rozdzielania nisko polarnych organicznych związków chemicznych w warunkach chromatografii cieczowej w normalnych układach faz, w odniesieniu do żelu krzemionkowego jako nośnika. Opracowano...
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I love to write and create. Can I earn money doing it? Entrepreneurial process of bloggers
PublikacjaNew technologies and a new way of looking at the life of future generations, open up new perspectives of entrepreneurial activities. One of them is to run a blog. Although the first blogs appeared many years ago and earning money from running them is also known to bloggers, little research is devoted to this form of entrepreneurship. The analysis of this phenomenon was carried out using the netnography method, which is not common...
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Ti3C2 MXenes-based catalysts for the process of α-pinene isomerization
PublikacjaIn this study, the catalytic performance of Ti3C2 MXene materials in the reaction of α-pinene isomerization was demonstrated. The influence of etching agents (HF, HF/H2SO4, and HF/HCl; weight ratios of mixed acids: 1 : 3, 1 : 4, and 1 : 5) on removing Al atoms from MAX phase, creation of an accordion-like structure typical...
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A new procedure for the determination of distillation temperature distribution of high-boiling petroleum products and fractions
PublikacjaThe distribution of distillation temperatures of liquid and semi-fluid products, including petroleum fractions and products, is an important process and practical parameter. It provides information on properties of crude oil and content of particular fractions, classified on the basis of their boiling points, as well as the optimum conditions of atmospheric or vacuum distillation. At present, the distribution of distillation temperatures...
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Removal of VOCs from air and assessment of dominant species in a peat-perlite biotrickling filter
PublikacjaAir pollution has become a major concern because it is inevitably connected with the rapid development of both industrial and residential areas. Volatile organic compounds (VOCs) are emitted from various anthropogenic sources e.g. transportation, factories or landfills as well as recycling factories. It is problematic not only because of the direct impact on humans and environment but also from economy viewpoint as it increases...
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The gaseous messenger carbon monoxide is released from the eye into the ophthalmic venous blood depending on the intensity of sunlight
PublikacjaCircadian and seasonal rhythms in daylight affect many physiological processes. In the eye, energy of intense visible light not only initiates a well-studied neural reaction in the retina that modulates the secretory function of the hypothalamus and pineal gland, but also activates the heme oxygenase (HO) to produce carbon monoxide (CO). This study was designed to determine whether the concentration of carbon monoxide (CO) in the...
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Nowe rozwiązania metodyczne i techniczne w zakresie techniki mikroekstrakcji do fazy stracjonarnej
PublikacjaSample preparation has been recognized as a critical step of the analytical process, being even considered as the bottleneck of the overall process. Enrichment of target compounds, transfer of the analytes into a solvent compatible with the analytical instrumentation, minimization of potential interferences, and efficient sample clean-up, are among the main aims of sample preparation techniques. In this regard, liquid-liquid extraction...
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Mechanism of Binding of Antifungal Antibiotic Amphotericin B to Lipid Membranes: An Insight from Combined Single-Membrane Imaging, Microspectroscopy, and Molecular Dynamics
PublikacjaAmphotericin B is a lifesaving polyene antibiotic used in the treatment of systemic mycoses. Unfortunately, the pharmacological applicability of this drug is limited because of its severe toxic side effects. At the same time, the lack of a well-defined mechanism of selectivity hampers the efforts to rationally design safer derivatives. As the drug primarily targets the biomembranes of both fungi and humans, new insights into the...
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Application of the J-matrix method to multichannel scattering
PublikacjaIn this contribution we describe the multichannel extension to the nonrelativistic J-matrix method, and present differential cross sections for scattering of slow electrons from Argon atoms. Nonrelativistic phase shifts, then the S-matrix and the cross sections have been calculated using newly developed Fortran code, JMATRIX-MULTI.We applied the model Hartree-Fock potential as the scattering potential, which was truncated in the...
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Antitumor 1-nitroacridine derivative C-1748 induces significant apoptosis in pancreatic cancer cells.
PublikacjaPancreatic cancer is the fifth leading cause of cancer death and has the lowest survival rate of any solid cancer in the industrial countries. The poor prognosis of pancreatic cancer results from its tendency for late presentation, aggressive invasion, early metastasis, and resistance to chemotherapy. Gemcitabine still remains the best chemotherapeutic agent available for the treatment of advanced pancreatic cancer. However, gemcitabine...
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Unraveling the role of boron dimers in the electrical anisotropy and superconductivity in boron-doped diamond
PublikacjaWe use quantum mechanics (QM) to determine the states formed by B dopants in diamond. We find that isolated B sites prefer to form BB dimers and that the dimers pair up to form tetramers (BBCBB) that prefer to aggregate parallel to the (111) surface in the <110> direction, one double layer below the H-terminated surface double layer. These tetramers lead to metallic character (Mott metal Insulator Transition) with holes in the...
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An Attempt to Develop a Model Selection Algorithm of Computer Simulation during the Design Process of Mechanical Response of Any Mechanical Body
PublikacjaIn the literature, there are algorithms associated with the design of simulations of technological processes, in which the material model has always been defined previously. However, in none of the studies of computer simulation modelling of technological processes known to the authors of this article, is there a detailed description of how the algorithm, or the selection of plastic model used, is subject to this process. This...
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Preparation and Characterization of Diamond-like Carbon Coatings for Biomedical Applications—A Review
PublikacjaDiamond-like carbon (DLC) films are generally used in biomedical applications, mainly because of their tribological and chemical properties that prevent the release of substrate ions, extend the life cycle of the material, and promote cell growth. The unique properties of the coating depend on the ratio of the sp3/sp2 phases, where the sp2 phase provides coatings with a low coefficient of friction and good electrical conductivity,...
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Next generation automatic IP configuration deployment issues
PublikacjaAlthough Dynamic Host Configuration Protocol for IPv6 (DHCPv6) protocol was defined in 2003, it was designed as a framework rather than a complete solution to the automatic configuration in IPv6 networks. There are still some unsolved problems and new options yet to be defined. One example of such case is Fully Qualified Domain Name (FQDN) option, which final version has been published in late 2007. It describes DHCPv6 client...
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Au-RE-TiO2 nanocomposites: Surface characteristics and photoactivity
PublikacjaThe photocatalysts based on TiO2 co-doped with rare earth metal (RE) and gold nanoparticles have been prepared using a sol-gel method and followed by gold reduction. Specific surface areas of the modified photocatalysts were calculated by the Brunauer-Emmett-Teller method (BET). Diffuse reflectance spectra of the obtained photocatalysts were recorded in a UV-Vis spectrophotometer (DRS UV-Vis). The influence of the type of rare...
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Effects of Na+, K+ and B3+ Substitutions on the Electrical Properties of La10Si6O27 Ceramics
PublikacjaDoping of Na and K at La sites and of B at Si site in La10Si6O27 with oxyapatite structure and fabrication of their ceramics were made by the solid-state reaction method. It was found that partial substitution of Na+ and K+ on La sites decreased the sinterability of the La10Si6O27 based ceramics, whereas partial substitution of B3+ on the Si site improved the sinterability. Na+ and K+ substitutions in La10−xNaxSi6O27−x and La10−xKxSi6O27−x...
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An attempt to develop a model selection algorithm of computer simulation during the design process of mechanical response of any mechanical body
Publikacjan the literature, there are algorithms associated with the design of simulations of technological processes, in which the material model has always been defined previously. However, in none of the studies of computer simulation modelling of technological processes known to the authors of this article, is there a detailed description of how the algorithm, or the selection of plastic model used, is subject to this process. This article...
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Analytical procedures for the determination of surfactants in environmental samples
PublikacjaBecause of their specific physical and chemical properties (amphiphilicity, solubility in polar and nonpolar liquids, ability to form micelles, adsorption at phase boundaries, low toxicity) surfactants (surface-active compounds) are widely applied in industry and in the household. As their applications are on a very large scale, it has become necessary to acquire a more detailed understanding of their environmental fate.In the...
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Synthesis, molecular structure, and metabolic stability of new series of N' -(2-alkylthio-4-chloro-5-methylbenzenesulfonyl)-1-(5-phenyl-1 H -pyrazol-1-yl)amidine as potential anti-cancer agents
PublikacjaA series of new N'-(2-alkylthio-4-chloro-5-methylbenzenesulfonyl)-1-(5-phenyl-1H-pyrazol-1-yl)amidine derivatives have been synthesized and evaluated in vitro by MTT assays for their antiproliferative activity against cell lines of colon cancer HCT-116, cervical cancer HeLa and breast cancer MCF-7. The studied compounds display selective activity mainly against HCT-116 and HeLa cells. Thus, five compounds show selective cytotoxic...
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Effect of Semiconductor Element Substitution on the Electric Properties of Barium Titanate Ceramics
PublikacjaThe investigated ceramics were prepared by a solid-state reaction from simple oxides and carbonates with the use of a mixed oxide method (MOM). The morphology of BaTi0.96Si0.04O3 (BTSi04) ceramics was characterised by means of a scanning electron microscopy (SEM). It was found that Si+4 ion substitution supported the grain growth process in BT-based ceramics. The EDS results confirmed the high purity and expected quantitative composition...
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INFLUENCE OF CERAMIC COATING ON MECHANICAL PROPERTIES OF STAINLESS STEEL
PublikacjaCrystal structure and phase composition of stainless steel substrates (AISI 304 type) was studied and it was found that they adopted the cubic symmetry. The calculated elementary cell parameter for the mayor Fe-Ni phase (weight fraction 99%) was a = 3.593 Å, whereas the mean grain size was = 2932 Å. Morphology of the stainless steel substrate surface was studied with profilometry. Mechanical properties of the stainless steel...
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Design and evaluation of a base module of active power electronic transformer
PublikacjaThis paper presents an active power electronic transformer (APET) based on modular structure. The proposed three phase APET consists of at least three base modules (BM). The input/output stage of the BM is based on half-bridge sub modules. The isolation stage includes a medium frequency transformer and is realized as a dual half-bridge. The paper describes construction process and explains the control strategy. The theoretical...
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An advanced thermal-FSI approach of an evaporation of air heat pump
PublikacjaThe paper presents selected problems of numerical modeling of an advanced thermal-FSI approach of evaporator of air heat pomp. The example of a fin-tube evaporator has been studied, focusing on obtaining of heat exchanger characteristics applying two-phase flow model for the in-tube refrigerant flow. Special attention is given to heat transfer between separated medium for different air velocity and changed refrigerant mass flow...
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Nowoczesne rozwiązania stosowane w kontekście ograniczenia strat energetycznych w budynkach oraz poprawy komfortu cieplnego
PublikacjaW artykule zaprezentowano nowoczesne rozwiązania pozwalające na zmniejszenie energochłonności budynków oraz ograniczenie wpływu warunków atmosferycznych na komfort cieplny. Omówiono metodologię optymalizacji kształtu oraz rodzaju materiałów wykorzystywanych w procesie powstawania budynków użytkowych. Zaprezentowano tu metody oparte o najnowsze zdobycze techniki takie jak materiały budowlane z domieszką PCM (ang. Phase change materials)
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Three-Level Z-Source Neutral-Point-Clamped Inverter
PublikacjaThe paper describes construction and the principles of activity, attributes and potential of 3-phase Z-type inverters. The paper focuses on the basic system and suggested 3-level system of a NPC type Z-inverter, which was elaborated by authors. Simplified theoretical analysis of both systems has been verified by detailed simulation research. In the last section of the article, the possibility to build multilevel Z- inverters based...
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Numerical modeling of the combustion in a lab-scale pulverized-coal fired combustion chamber
PublikacjaThis work presents results of numerical modeling of the combustion process inside a lab-scale drop-tube chamber, designed to investigate the slagging properties of the flue ashes, created through the solid fuel firing. Interaction between turbulence and chemistry is accounted by use of probability density function (PDF). FLUENT inputs for non-premixed combustion chemistry modeling are defined. A discrete second phase of the coal...
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Free convection of water-Al2O3 nanofluid from horizontal porous coated tube
PublikacjaNanofluids are expected to enhance heat transfer in many thermal systems. Present efforts are concentrated on boiling heat transfer of nanofluids, although single phase convection is of key importance in various appliances such as car radiators or heating systems. This paper presents experimental results of heat transfer during free convection of water-Al3O3 nanofluid from horizontal tube covered with metallic porous coating. Contrary...
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A novel method of local chirp-rate estimation of LFM chirp signals in the time-frequency domain
PublikacjaIn the paper, novel dynamic representations of a complex signal in the time-frequency domain are introduced. The proposed approach is based on using the gradient of the short-time Fourier transform complex phase. A channelized instantaneous complex frequency (CICF) and a complex local group delay (CLGD) are included in the presented signal representations. An application of the newly-introduced distributions is demonstrated by...
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Numerical modeling of the combustion in a lab-scale pulverized-coal fired combustion chamber
PublikacjaThis work presents results of numerical modeling of the combustion process inside a lab-scale drop-tube chamber, designed to investigate the slagging properties of the flue ashes, created through the solid fuel firing. Interaction between turbulence and chemistry is accounted by use of probability density function (PDF). FLUENT inputs for non-premixed combustion chemistry modeling are defined. A discrete second phase of the coal...
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Conjugated control of triple active bridge converter with common HFT
PublikacjaPaper presents synthetic analyses of single input, dual output DC/AC/DC converter with common high frequency transformer. Rise the problem of cross-coupling power flows between secondary terminals, under asymmetrical control operating condition. It also proposes a new approach to converter control, based on conjugated phase shift modulation and defines its limitations. Finally, the developed control technique was verified by simulation...
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A study of the photoelectron spectra of α-tetrahydrofurfuryl alcohol over the outer valence energy region (9–25 eV)
PublikacjaPhotoelectron spectra of α-tetrahydrofurfuryl alcohol (THFA) molecules, the threshold spectrum and spectra for constant photoelectron energies, have been measured over the photon energy range 9–25 eV. Analysis of the photoelectron spectra has allowed overlapping photoionization bands to be separated, tentatively assigned and their vertical photoionization energies to be determined. These energies are compared with existing theoretical...
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Wzbudzone siły wewnętrzne : skutki upr0szczonego modelowania zakrzywionej estakady sprężonej
Publikacjathe paper presents problems, which were encountered during the construction of a southern road bypass of city gdansk. after prestressing and removing formwork, the contractor spotted, that some of outer bearings are detached. performed analysis showed that, this situation was caused by the usage of a simplified, straight beam model during design phase. the paper shows the influence of a curved in plane prestressed system on internal...