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1
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Polish Journal of Chemistry
EN V2O5/_-Al2O3 catalysts for the dehydrogenation of isobutane to isobutene were prepared by impregnation and characterized by BET,H2-TPR, ESR and XPS. Based on our studies of the effects of the extent of catalyst reduction on catalytic performance, we conclude that the V2O5/_-Al2O3 catalytic activity [...]
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Polish Journal of Chemistry
2002 Vol. 76 / nr 12 1733-1738
EN Undoped and K-doped V2O5/ -Al2O3 catalysts for the dehydrogenation of isobutane to isobutene were prepared by impregnation and characterized by means of BET, H2-TPR, NH3-TPD, XPS and ESR. It is found that potassium addition changes acidic and electric properties of V2O5/ -Al2O3 and results in a bett[...]
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Przegląd Elektrotechniczny
PL W artykule przedstawiono nową metodę sterowania generatorem DFIG, pracującym przy przejściowo niskim napięciu. Proponowany algorytm umożliwia pracę w takich warunkach, poprzez zmianę nastawy tylko jednego parametru. Osiągnięto płynność przejścia między stanem ustalonym a stanem zapadu napięcia. Prze[...]
EN This paper proposes a novel control strategy for doubly fed induction generator (DFIG) low voltage ride through (LVRT) under asymmetrical grid voltage dip. The proposed strategy, named as direct power control based multi-objective control, enables the DFIG operating under asymmetrical grid voltage d[...]
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Przegląd Elektrotechniczny
PL W artykule przedstawiono opracowane sterowanie predykcyjne MPC dla prostownika MSI. Brak separacji między składowymi zgodną i przeciwną napięcia i prądu, pozwala na znaczną redukcję składowej przeciwnej, zwiększenie dynamiki odpowiedzi oraz elastyczności pracy algorytmu. Przedstawione wyniki ekspery[...]
EN In order to improve the DC-side voltage and AC-side current of the pulse width modulation (PWM) rectifier on unbalanced grid voltage conditions, the paper proposed a model predictive control (MPC) strategy of PWM rectifier. With no separation of the positive and negative sequence components of volta[...]
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Journal of Theoretical and Applied Mechanics
2013 Vol. 51 nr 4 1027--1038
EN Abstract MAVs (Micro Air Vehicles) have attracted more and more attention in recent years because of their wide applications, such as investigations of inhospitable environment, nuclear or hazardous material polluted regions and other inaccessible areas. In this paper, both attitude and altitude con[...]
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Acta Chromatographica
EN A simple and precise high-performance liquid chromatographic (HPLC) method has been developed for analysis of flavonoids in Lamiophlomis rotata. HPLC conditions were optimized. Baseline separation was achieved by use of a binary gradient prepared from 100:0.2 (v/v) water-trifluoroacetic acid (compon[...]
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Przegląd Elektrotechniczny
2012 R. 88, nr 9b 145-149
PL Analizowano układ wirnika z dwoma dyskami. Symulowano tarcie między wirnikiem i stojanem a separacja była uwzględniana jako zmiana cylindrycznej szczeliny.
EN In this paper, taking a single span flexible rotor system with two discs as the research object, the finite element model of the rotor-bearing system is established. The stator is simplified as a group of equispaced points along the circumference and the rotor as a point based on the contact dynamic[...]
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Fundamenta Informaticae
2013 Vol. 124, nr 3 271--295
EN A schema algebra comprises operations on database schemata for a given data model. Such algebras are useful in database design as well as in schema integration. In this article we address the necessary theoretical underpinnings by introducing a novel notion of conceptual schema morphism that capture[...]
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Przegląd Elektrotechniczny
PL W artykule opisano zastosowanie wielopoziomowego przekształtnika do sterowania silnikiem z magnesami trwałymi. Osiągnięto bardzo dobra jakość kształtu sygnału napięciowego I małe dV/dt. Dzięki temu uzyskano ultra duża szybkość do zastosowań lotniczych
EN The general concepts of multi-level technology involve utilizing a higher number of semiconductor devices to achieve higher power conversion, eliminate harmonics and reduce the switching loss. This paper is concerned with applying multi-level techniques to a PM motor to achieve ultra high speed feat[...]
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Polish Journal of Chemistry
EN The structural properties and vibrationalmode of the transitionmetal Fe subnitrosyl complexes Fe(NO)n (n = 1–4) have been examined by using HF, B3LYP, B3P86 and B3PW91 methods at 6-311G basis set level. Results indicate that the interaction between Fe and NO should be characterized as a dative bond,[...]
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Optica Applicata
2015 Vol. 45, nr 4 433--445
EN Simultaneous providing services of ultra-wideband and wired signal over single wavelength can greatly decrease the complexity and reduce the costs of a wavelength-division multiplexing passive optical network. However, ultra-wideband signal occupies the spectrum range from 3.1 to 10.6 GHz, and a nar[...]
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Acta Geophysica
2016 Vol. 64, no. 1 101--124
EN This article utilizes Savitzky–Golay (SG) filter to eliminate seismic random noise. This is a novel method for seismic random noise reduction in which SG filter adopts piecewise weighted polynomial via leastsquares estimation. Therefore, effective smoothing is achieved in extracting the original sig[...]
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Polish Journal of Chemical Technology
2013 Vol. 15, nr 2 122–127
EN The production processes included catalytic dehydration of methanol in an adiabatic fixed-bed reactor and two columns product separations. In this study, the technological process for dimethyl ether (DME) synthesis is built on PRO/II platform based on the combined parameters of the reaction dynamic [...]
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Materials Science Poland
2012 Vol. 30, No. 4 355--358
EN In this paper, crack-free bulk thermoelectric material Zn4Sb3 was prepared rapidly by high pressure and high temperature (HPHT) method. Near a single-phase Zn4Sb3 specimen was obtained using nominal stoichiometric powder mixtures, which were indexed by powder X-ray diffraction. The temperature-depen[...]
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Acta Geophysica
2017 Vol. 65, no. 4 683--700
EN Understanding slip behavior of active fault is a fundamental problem in earthquake investigations. Well logs and cores data provide direct information of physical properties of the fault zones at depth. The geological exploration of the Wenchuan earthquake Scientific Fault drilling project (WFSD) ta[...]
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Polish Journal of Chemical Technology
EN PtSn/Al2O3 &enspcatalysts with a given loading of 1 wt% Pt and 1 wt% Sn were prepared by co-impregnation or successive impregnation with aqueous solutions of Pt, Sn precursors and a commercial alumina. The catalysts were characterized by N2 &enspadsorption, H2
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Polish Journal of Chemical Technology
EN B-ZSM-5 catalysts were prepared by various modification methods with boric acid, including ion-exchange, impregnation and direct synthesis. The catalysts were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), NH3-Temperature Programmed Desorption (NH3-TPD), N2 adsorption-[...]
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Polish Journal of Chemical Technology
2015 Vol. 17, nr 1 103--109
EN The present work was a study on global reaction rate of methanol synthesis. We measured experimentally the global reaction rate in the internal recycle gradientless reactor over catalyst SC309. The diffusion-reaction model of methanol synthesis was suggested. For model we chose the hydrogenation of [...]
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Central European Journal of Energetic Materials
2017 Vol. 14, no. 1 251--265
EN In order to solve the aluminum surface ablation issue of Al-Steel bimetallic pipes manufactured by the explosive welding technique, a novel explosive welding system has been designed to weld Al-Steel coaxial pipes. The stand-off distance was chosen according to an empirical formula. A special Explos[...]
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Chemia Analityczna
PL Zbadano oddziaływanie nowego odczynnika fluorescencyjnego: dibromohydroksyfluoron-molibden(VJ) (DBHPF-Mo(VI) z białkiem, W obecności emulgatora OP, przy pH 3,2 mikroemulsja kompleksu DBHPF-Mo(Vl) wiąże szybko białko, tworząc trwale połączenie o długości fali promieniowania wzbudzającego 468 nm i emi[...]
EN In this paper binding interaction between a new fluorescence probe dibromohydroxyphenyi-fluoronc-molybdenum(VI) (DBHPF-Mo(Vl) and a protein has been studied. In the presence of the cmulsifier OP microemulsion of pH 3.2 DBHPF-Mo(VI) complex binds the protein rapidly to form a stable compound of a max[...]
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