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Search results for: latarka led
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A structure and simulation-driven design of compact CPW-fed UWB antenna
PublicationIn this letter, a structure of a miniaturized ultra-wideband CPW-fed antenna and its design proce-dure are presented. The antenna is a modified version of the design previously proposed in the literature, with additional degrees of freedom introduced in order to improve the structure flexibility. The small size is achieved by executing a rigorous optimization procedure that consists of two stages: (i) smart random search carried...
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Voltage Control of a Stand-Alone Multiphase Doubly Fed Induction Generator
PublicationThis article presents a multiphase doubly fed induction generator (MDFIG) with a dedicated and unique control algorithm in a stand-alone wind energy conversion system. The algorithm has been developed and elaborated in the case of different emergency modes. Compared with the traditional double-fed induction generator, the MDFIG has increased reliability, reduced current level per phase, and low rotor harmonic currents. The control...
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Feedback Control of Doubly-Fed Generator Connected to Current Source Converter
PublicationDoubly-fed induction generator (DFIG) system supplied by current source converter (CSC) is considered in this article. The DFIG can work in two independent modes: AC grid connection and stand-alone mode. The DFIG is connected to the ac grid directly through its stator and the CSC links the rotor side. In this mode, the active and reactive powers of the DFIG must be controlled. This article proposes two control system structures...
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Macrocyclic derivatives of imidazole as chromoionophores for bismuth(III)/lead(II) pair
Publication18-membered diazomacrocycles with imidazole or 4-methylimidazole residue as a part of macrocycle were used as chromoionophores in bismuth(III) and lead(II) dual selective optodes for the first time. Cellulose triacetate membranes doped with macrocyclic chromoionophores are bismuth(III) and lead(II) selective with color change from orange/red to different shades of blue and violet, respectively. Results obtained for model and real...
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Nonlinear Control of a Doubly Fed Generator Supplied by a Current Source Inverter
PublicationNowadays, wind turbines based on a doubly fed induction generator (DFIG) are a commonly used solution in the wind industry. The standard converter topology used in these systems is the voltage source inverter (VSI). The use of reverse-blocking insulated gate bipolar transistor (RB-IGBT) in the current source inverter topology (CSI), which is an alternative topology, opens new possibilities of control methods. This paper presents...
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Red Algae – An Alternative Source of Carbon Material for Energy Storage Application
PublicationNew electrode material obtained by pyrolysis of aquatic biomass macro (red algae) soaked with glucose solution has been characterized by SEM, EDX and Raman spectroscopy. Graphitized carbon was identified by Raman spectroscopy. Galvanostatic cyclic polarization of the materials in contact with 1M LiPF6 electrolyte in EC:DMC (1:1 v/v) and Li as a counter electrode was performed. Specific capacity of the novel material was enhanced...
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Electrical properties and structure of lead-borate glass containing iron ions.
PublicationThe ac and dc conductivity in iron–lead-borate glass samples was investigated in the frequency range from 1 mHz to 1 MHz and in the temperature range from 153 K to 423 K. The structure was investigated by the means of atomic force microscopy (AFM) and the crystalline phases (if present) were identified by the means of X-ray diffractometry. Two types of ac electrical behaviour were observed. The first group of glass samples which...
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Estimation of the uncertainty of the LEM CV 3-500 transducers processing function
PublicationThe paper presents the methodology for estimating uncertainty of a voltage transducer processing function based on the example of LEM CV 3-500 transducer. The analysis was performed using the method based on the GUM Guide propagation of uncertainty law and the Monte Carlo numerical method. The article also presents a comparative analysis of the results of a voltage measurement evaluation done using the Monte Carlo simulation method,...
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Evidence for solid state electrochemical degradation within a small molecule OLED
PublicationAcridone derivative have been synthesised and used as OLED (Organic Light Emitting Diode) emitters which were found to be electroactive. Electrochemical investigations showed a side reaction takes place inside an active layer which diminished the overall device efficiency. By using a dopant and host active layer architecture, the formation of the by product was removed. The by-product was identified as a σ-dimer formed inside an...
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A Conformal Circularly Polarized Series-Fed Microstrip Antenna Array Design
PublicationA conformal circularly polarized series-fed microstrip array design for broadside radiation is presented. The array aperture under design is conformal to a cylindrical surface of a given radius. The approach we present primarily addresses focusing of the circularly polarized major lobe of the conformal array by proper dimensioning of the aperture spacings. The proposed analytical models yield the values of the element spacings...
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3D PCB package for GaN inverter leg with low EMC feature
PublicationThis paper presents the adaptation of a 3D integration concept previously used with vertical devices to lateral GaN devices. This 3D integration allows to reduce loop inductance, to ensure more symmetrical design with especially limited Common Mode emission, thanks to a low middle point stray capacitance. This reduction has been achieved by both working on the power layout and including a specific shield between the devices and...
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Degradation of the Concrete Railway Track Bed Located in the Vicinity of the Loading Wharf
PublicationThe following article describes the damages of the concrete railway track bed at the place of unloading petroleum products located in the immediate vicinity of the cargo berth. The concrete of the track bed has been a subject to degradation as a result of many years of exploitation resulting, inter alia, in its cyclical flooding of petroleum products during the unloading and loading of rail tankers. Repairs carried out in the previous...
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Non-Adaptive Speed and Position Observer of Doubly-Fed Induction Generator
PublicationThe non-adaptive speed and position estimation of a doubly-fed induction generator (DFIG) is presented in this paper. The speed observer is based on the mathematical model of DFIG and to stabilize the structure the Lyapunov method is used. The classic stator field-oriented control to active and reactive power control is used in the sensorless control system. The performance of the proposed algorithm of a speed observer is validated...
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Pyrrole bearing diazocrowns: Selective chromoionophores for lead(II) optical sensing
PublicationDiazocrowns of 18-, 21- and 23-membered rings with pyrrole residue as a part of macrocycle were for the first time used as chromoionophores in lead(II) selective optodes. Sensing properties of optodes depend on the type of macrocycle, namely its size and the type of linker: oligoether or hydrocarbon chain. The best results were obtained for optode bearing 18-membered crown with oligoether linker showing linear response range of...
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EMI mitigation of GaN power inverter leg by local shielding techniques
PublicationThis paper presents local shielding techniques applied to a half-bridge inverter leg with the aim to reduce the common mode (CM) current noise at converter’s DC input. The research study is conducted for 650V Enhancement mode Gallium Nitride (GaN) power transistor switches. Main contributors of parasitic capacitances referred to the inverter-leg middle point node are identified. Then, shielding solutions are proposed to reduce...
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Development and performance analysis of a novel multiphase doubly-fed induction generator
PublicationThis paper presents the research into the design and performance analysis of a novel five-phase doubly-fed induction generator (DFIG). The designed DFIG is developed based on standard induction motor components and equipped with a five-phase rotor winding supplied from the five-phase inverter. This approach allows the machine to be both efficient and reliable due to the ability of the five-phase rotor winding to operate during...
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Nitrogen mass balance and mathematical model of a Structured- Bed Reactor (SBRRIA)
PublicationAn up-flow structured-bed reactor subjected to recirculation and intermittent aeration (SBRRIA) was operated under varying influent conditions. The influent COD/N ratio was adjusted by maintaining a stable organic loading rate (average of 1.07 kgCOD m-3 d-1) and changing the nitrogen loading rate from 0.1 to 0.4 kg N m-3. Therefore, three different COD/N ratios were tested: 9.7±1 (Scenario 1); 7.6±1 (Scenario 2) and 2.9±1 (Scenario...
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Technique for reducing erosion in large-scale circulating fluidized bed units
PublicationThis paper presents a methodology, implemented for a real industrial-scale circulating fluidized bed boiler, to mitigate the risk of heating surfaces exposed to an intensive particle erosion process. For this purpose, a machine learning algorithm was developed to support the boiler reliability management process. Having a tool that can help mitigate the risk of uncontrolled power unit failure without expensive and technically complex...
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Biodiversity assessment of ascomycetes inhabiting Lobariella lichens in Andean cloud forests led to one new family, three new genera and 13 new species of lichenicolous fungi
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Authors’ Response to the Letter by Lamarca et al. Entitled “Temozolomide-Capecitabine Chemotherapy for Neuroendocrine Neoplasms: The Dilemma of Treatment Duration” Regarding “Activity and Safety of Standard and Prolonged Capecitabine/Temozolomide Administration in Patients with Advanced Neuroendocrine Neoplasms”
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Cahiers d'histoire de l'art (Les)
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Mots: Les langages du politique
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Iranian Red Crescent Medical Journal
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RED-Revista de Educacion a Distancia
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Gastroenterology and Hepatology from Bed to Bench
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RED-Revista Electronica de Direito
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ACS Bio and Med Chem Au
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Iranian Red Crescent Medical Journal
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The Role of miRNA in Papillary Thyroid Cancer in the Context of miRNA Let-7 Family
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Implementation of an example of Hierarchical Petri Net (HPN) in LAD language in TIA Portal
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Evaluation of Analytes Characterized with Potential Protective Action after Rat Exposure to Lead
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Cavity-QED tests of representations of canonical commutation relations employed in field quantization
PublicationDane eksperymentalne dotyczące oscylacji Rabiego porównano z opisem teoretycznym w ramach alternatywnych sformułowań elektrodynamiki kwantowej. Okazało się, iż eksperyment nie jest w stanie rozróżnić opisu standardowego od nowego sformułowania opartego o redukowalne reprezentacje CCR. Zaproponowano nowy eksperyment, którego wynik mógłby być rozstrzygający.
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Ocena zgodności regulatorów automatyki z wymaganiami dyrektyw LVD i EMC
PublicationArtykuł przedstawia wstępną analizę wymagań normy PN - EN 60730-1 dotyczącej automatycznych regulatorów elektrycznych do użytku domowego. Podana norma ma status normy zharmonizo-wanej i w związku z tym spełnienie jej wymagań umożliwia producentowi wykazanie zgodności wprowadzonego na rynek wyrobu z wymaganiami dyrektyw - niskonapięciowej (LVD) i kompatybilności elektromagnetycznej (EMC). W artykule szerzej opisano wymagania mające...
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Temperature effect on the emission spectra of narrow band Mn4+phosphors for application in LEDs
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KUHLMAN U. (red.): Stahlbau Kalender 2009 (Kalendarz budownictwa stalowego 2009)
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Electronic and nuclear properties from the analysis of the isotope shifts in the spectral lines of lead
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Steady State Analysis of Twin Stator Cascaded Doubly Fed Induction Generator
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Influence of modification by superdispersed powder of aluminum oxide on lead-tin bronze structure
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Independent Mechanisms Lead to Genomic Instability in Hodgkin Lymphoma: Microsatellite or Chromosomal Instability
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Simplified saturation modelling in three-leg power transformer for the system stability analisys
PublicationThe paper presents a simplified method for modelling non-linearity of the magnetic circuit of the power transformer. The saturation effect is implemented by describing the self and mutual inductances as a function of the magnetic flux. The most important element of this function is the saturation coefficient which is calculated based on transient state during the unloaded transformer switch on. The transformer model is described...
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Size-Reduction-Oriented Design of Compact CPW-Fed UWB Monopole Antenna
PublicationA structure and design optimization of compact CPW-fed UWB monopole antenna is presented. Explicit size reduction through constrained numerical optimization of all relevant geometry parameters of the structure leads to a very small footprint of only 321 mm2. At the same time, a very wide antenna bandwidth is achieved from 3.1 GHz to 17 GHz.
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Effects of subfilter velocity modelling on dispersed phase in LES of heated channel flow
PublicationA 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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Numerical and experimental investigation of rotational stiffness of zed-purlins connection with sandwich panels
PublicationA rotational resistant stiffness of the zed-purlins connection with sandwich panels is investigated. A simple finite element method model of the connection is proposed. The numerical analysis of the model performed by ABAQUS software, in physically linear and geometrically nonlinear ranges, leads to the rotational resistant stiffness sought. The numerical solution obtained is verified experimentally. Two variants of distribution...
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Experimental Investigation of an Intensified Heat Transfer Adsorption Bed (IHTAB) Reactor Prototype
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Performance Evaluation of a Single-Stage Two-Bed Adsorption Chiller With Desalination Function
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Application of stereology for two-phase flow structure validation in fluidized bed reactors
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Drgania mechaniczne. Rozwiązywanie zagadnień z MATHCAD-em. Red. E. Kiliś.
PublicationAutor niniejszej książki proponuje inny, nowoczesny sposób studiowania drgań mechanicznych, który charakteryzuje się poznawaniem teorii wraz z jednoczesnym wdrażaniem jej do analizy własności dynamicznych układów mechanicznych. Stosuje do tego celu wspomaganie komputerowe za pomocą bardzo rozpowszechnionego i łatwego w użyciu programu MATHCAD. Wyjaśnia naturę zjawiska drgań mechanicznych i jego znaczenie w technice oraz wpływ na...
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Calculation of lead settlement curve based on CPT test results and Auger Piles.
PublicationPrzedstawiono wykorzystanie wyników statycznego sondowania CPT do określenia pełnej krzywej osiadania, aż do obciążenia granicznego. Wykorzystano wyniki badań statycznych dla 23 wierconych pali wielkośrednicowych. Przedstawiono zależności korelacyjne bazujące na analizie statystycznej.
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Mechanika ogólna. Rozwiązywanie zagadnień z MATHCAD-em. Red. E. Kiliś.
PublicationPrzedstawiono rozwiązywanie zadań z mechaniki ogólnej za pomocą programu MATHCAD. Zaprezentowano wykorzystanie możliwości tego programu zarówno w zakresie przekształceń symbolicznych i obliczeń numerycznych, jak i wizualizacji graficznych. W części pierwszej opisano program MATHCAD, kładąc akcent na te jego funkcje, które mogą być przydatne w rozwiązywaniu zadań z mechaniki ogólnej. Część druga zawiera przykłady zadań...
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Effects of artificial lighting on bioactivity of sweet red pepper (Capsicum annuum L.)
PublicationRecent studies have shown that artificial light effectively promotes the growth and development of red peppers when light spectra, intensities and duration are controlled. Cited reports deal mostly with studies involving with the growth stages of pepper. Changes in the biochemical status of plants were not studied. Therefore, this study focuses on the changes in the content of some bioactive compounds (polyphenols, flavonoids,...