126 research outputs found

    Association between quantum paradoxes based on weak values and a realistic interpretation of quantum measurements

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    Many quantum paradoxes based on a realistic view of weak values were discussed in the last decades. They lead to astonishing conclusions such as the measurement of a spin component of a spin-1/2 particle resulting in 100ℏ100\hbar, the separation of a photon from its polarization, and the possibility of having 3 particles in 2 boxes without any 2 particles being in the same box, among others. Here we show that the realistic view of the weak values present in these (and other) works is equivalent to a realistic (and highly controversial) view of quantum measurements, where a measurement reveals the underlying reality of the measured quantity. We discuss that all quantum paradoxes based on weak values simply disappear if we deny these realistic views of quantum measurements and weak values. Our work thus aims to demonstrate the strong assumptions and the corresponding problems present in the interpretation of these quantum paradoxes.Comment: 7 pages, 3 figures. To appear in Physical Review

    Study of a simplified model for DFIG-based wind turbines

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    In the study of the dynamical behavior of doublyfed induction generators (DFIG), for wind power applications, the use of reduced order models is useful in order to design specific control strategies for wind power plants as well as to obtain lightweight computing simulations. Within this field this paper presents a new dynamic model for wind turbines, based on DFIG, able of representing accurately its behavior during both the steady state and the transient of the grid voltage. As it will be proven this model permits to perform an accurate analysis of the system when there is a voltage dip in the grid. In the following a theoretical study of this model will be carried out and the accuracy of its performance will be tested under different conditions, by means of PSCAD/EMTDC simulations, in order to show its reliability. Finally the reliability of the simplified model will be tested in a scaled experimental setup.Peer ReviewedPostprint (published version

    Design and implementation of a modified fourier analysis harmonic current computation technique for power active filters using DSPs

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    The design and implementation of a harmonic current computation technique based on a modified Fourier analysis, suitable for active power filters incorporating DSPs is presented. The proposed technique is suitable for the monitoring and control of load current harmonics for real-time applications. The derivation of the basic equations based on the proposed technique and the system implementation using the Analogue Devices SHARC processor are presented. The steady state and dynamic performance of the system are evaluated for a range of loading conditions

    Compensation algorithms based on the p-q and CPC theories for switching compensators in micro-grids

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    The main objective of this paper is to com-pare the applicability and p erformance of a switching compensator when it is controlled by algorithms derived from the pq–Theory and from the Current’s Physical Components Power Theory (CPC-Theory) considering a micro-grid application. Compensation characteristics derived from each one of these set of power definitions are highlighted, and simulation results of test cases are shown. Special attention is put on the oscillating instan-taneous real power, as it may produce torque oscillations or frequency variations in weak systems (micro-grids) generators. The oscillating instantaneous real power, as defined in the pq-Theory, gives the amount of energy oscillating between the source and the load, and its com-pensation using a switching compensator must have an energy storage element to exchan ge it with the load. The energy storage element can be ea sily calculated with the pq-Theory

    Instantaneous p-q power theory for control of compensators in micro-grids

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    The main objective of this tutorial is to present the basic concepts on the instantaneous p-q Theory and them show its applicability for controlling switching converters connected in a micro-grid. These converters can be used for connecting renewable energy sources (solar, wind, and others) to the micro-grids or for harmonic, reactive power or unbalance compensation, and even for voltage regulation. The emphasis is given on the compensation characteristics derived from the p-q Theory, and simulation results of test cases are shown. Special attention is put on the oscillating component of the instantaneous real power, as it may produce torque oscillations or frequency variations in weak systems (micro-grids) generators. This oscillating component, as defined in the p-q Theory, gives the amount of oscillating energy between the source and the load, and its compensation through a switching compensator must have an energy storage element to exchange it with the load. With the p-q Theory the energy storage element can be easily calculated as a function of the average component of the instantaneous real power, which depends on the observation period.The authors acknowledge the support from FAPERJ partially for the development of this study and especially for the financial support for the participation in the conference

    Actividad antibiofilm de un extracto antibacteriano de schinus fasciculatus y sus componentes

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    Las bacterias fitopatĂłgenas poseen la capacidad de adherirse y colonizar los tejidos vegetales mediante biofilms. La formaciĂłn de estas pelĂ­culas bacterianas puede verse afectadas por la presencia de bactericidas en concentraciones sub-letales, algo que sucede comĂșnmente cuando la aplicaciĂłn de estos compuestos no es homogĂ©nea sobre la superficie de la planta. En este contexto, la actividad antibiofilm de un compuesto antibacteriano podrĂ­a contribuir al control de enfermedades vegetales que producen grandes pĂ©rdidas en los cultivos. En este trabajo se evaluĂł la capacidad de inhibiciĂłn de biofilm de un extracto con actividad antimicrobiana de Schinus fasciculatus y sus componentes en concentraciones sub-letales. El extracto foliar fAcet de Schinus fasciculatus y sus componentes, los flavonoides agatisflavona, quercetina, kaempferol se ensayaron en Concentraciones sub-letales previamente establecidas (125-1,9 ÎŒg/mL) para determinar su capacidad de inhibir la formaciĂłn de biofilm de 5 cepas fitopatĂłgenas, Pseudomonas syringae pv tomato Pseudomonas corrugata, Xanthomonas campestris pv vesicatoria, Erwinia carotovora var carotovora y Agrobacterium tumefaciens, mediante el ensayo de cristal violeta en microplaca descripto por O?Toole. Los resultados fueron analizados estadĂ­sticamente utilizando los test de Shapiro-Wilk, ANOVA y Kruskal-Wallis del software STATISTICA, version 7. La inhibiciĂłn de biofilm fue dependiente de la cepa bacteriana, y en menor medida del compuesto ensayado, siendo E. carotovora var. carotovora y A. tumefaciens las mĂĄs susceptibles, con inhibiciones de entre un 40-80%, mientras que P. corrugata y X. campestres pv vesicatoria fueron las menos susceptibles con una inhibiciĂłn mĂĄxima de un 39%. El extracto y los flavonoides inhibieron en un 40 a 80% la formaciĂłn de biofilm de las especies bacterianas ensayadas, por lo que en concentraciones sub-letales estos compuestos serĂ­an capaces de atenuar la patogenicidad de las bacterias fitopatĂłgenas investigadas.Fil: TerĂĄn Baptista, Zareath Pamela. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - TucumĂĄn; Argentina. Universidad Nacional de TucumĂĄn. Facultad de BioquĂ­mica, QuĂ­mica y Farmacia; ArgentinaFil: Aredes FernĂĄndez, Pedro AdriĂĄn. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - TucumĂĄn; Argentina. Universidad Nacional de TucumĂĄn. Facultad de BioquĂ­mica, QuĂ­mica y Farmacia; ArgentinaFil: Mandova, T.. Universidad Paris Descartes; FranciaFil: Kritsanida, M.. Universidad Paris Descartes; FranciaFil: Grougnet, R.. Universidad Paris Descartes; FranciaFil: Sampietro, Diego Alejandro. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - TucumĂĄn; Argentina. Universidad Nacional de TucumĂĄn. Facultad de BioquĂ­mica, QuĂ­mica y Farmacia; ArgentinaIV ReuniĂłn Conjunta de Sociedades de BiologĂ­a de la RepĂșblica Argentina: nuevas evidencias y cambios de paradigmas en Ciencias BiolĂłgicasMendozaArgentinaSociedad de BiologĂ­a de CĂłrdobaSociedad de BiologĂ­a de CuyoAsociaciĂłn de BiologĂ­a de TucumĂĄ

    Control algorithms based on the active and non-active currents for a UPQC without series transformers

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    This study presents control algorithms for a new unified power quality conditioner (UPQC) without the series transformers that are frequently used to make the insertion of the series converter of the UPQC between the power supply and the load. The behaviour of the proposed UPQC is evaluated in presence of voltage imbalances, as well as under non-sinusoidal voltage-and current conditions. The presented algorithms derive from the concepts involving the active and non-active currents, together with a phase-locked-loop circuit. Based on these real-time algorithms, and considering the proposed hardware topology, the UPQC is able to compensate the harmonic components of the voltages and currents, correct the power factor, and keep the load voltages regulated, all of this in a dynamic way, responding instantaneously to changes in the loads or in the electrical power system. The control algorithms were distributed in a two-DSP digital control architecture, without any communication between them. Consequently, can be increased the sampling frequency of the acquired voltages and currents and improve the UPQC performance. Furthermore, some constraints of the proposed UPQC are evidenced, particularly when the main voltages are imbalanced. Simulation and experimental results are presented to verify the UPQC performance under transient and steady state conditions.info:eu-repo/semantics/publishedVersio
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