70 research outputs found

    Back diffusion of electrons in argon subjected to uniform time invariant orthogonal electric and magnetic fields

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    In this study, the processes of back diffusion in Ar subjected to crossed fields are analyzed by using the Monte Carlo simulation method in the E/N range of 50 to 500 Td (1 Td = 1 × 10–17 V cm2) for 0 \u3c B/N \u3c 25 × 10−19 T cm3. At a given constant E/N, escape factors decrease with an increasing crossed, reduced magnetic field B/N. This reduction in the escape factor is more pronounced in the lower E/N range. Furthermore, the mean number of collisions of back scattered electrons is quite large, and at a given E/N, the mean number of collisions decreases as the crossed B/N increases

    Coordinate Transformation-Free Observer-Based Adaptive Estimation of Distorted Single-Phase Grid Voltage Signal

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    © 2013 IEEE. This paper studies the phase and frequency estimation problem of single-phase grid voltage signal in the presence of DC offset and harmonics. For this purpose, a novel parameterized linear model of the grid voltage signal is considered where the unknown frequency of the grid is considered as the parameter. Based on the developed model, a linear observer (Luenberger type) is proposed. Then using Lyapunov stability theory, an estimator of the unknown grid frequency is developed. In order to deal with the grid harmonics, multiple parallel observers are then proposed. The proposed technique is inspired by other Luenberger observers already proposed in the literature. Those techniques use coordinate transformation that requires real-time matrix inverse calculation. The proposed technique avoids real-time matrix inversion by using a novel state-space model of the grid voltage signal. In comparison to similar other techniques available in the literature, no coordinate transformation is required. This significantly reduces the computational complexity w.r.t. similar other techniques. Comparative experimental results are provided with respect to two other recently proposed nonlinear techniques to show the dynamic performance improvement. Experimental results demonstrate the suitability of the proposed technique

    A second‐order sliding mode control with active disturbance rejection for dynamic voltage restorers

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    This paper proposes an extended state observer (ESO)-based second-order sliding mode control (SMC) for dynamic voltage restorers (DVRs). Unlike the conventional first-order SMC and some second-order SMC (SOSMC) methods that suffer from chattering, the proposed control method can alleviate chattering and achieve finite-time convergence. Chattering suppression (i.e. eliminating discontinuities) is achieved via continuous control input which is also used to generate the pulse width modulation signals. However, while removing the discontinuities in the control input, the performance of the control method is degraded when it is subjected to disturbances. Therefore, an active disturbance rejection (ADR) based on an ESO is proposed to enhance the performance. In addition, an advanced single-phase phase-locked loop (PLL) using linear observer and quasi-type-1 PLL is also proposed. The effectiveness of the proposed method is verified through simulation and experimental results which are compared with the results of the existing SMC methods applied to DVR

    Seismic resistance of traditional timber-frame hımış

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    Hımış structures have hardly ever found as extensive a role as other traditional timber housing, such as those originating from Japan or Central Europe, within the wide discourse on the seismic performance of timber-frame architecture that has gained significant momentum in the last few decades owing to advancing testing technologies. While the hımış construction technique was perhaps not born as a result of a conscious search for a seismically resistant building form, it was soon widely appreciated for its structural features advantageous under seismic loading - especially from the sixteenth century when it has become a well-established construction technique in part of the Balkans and in today’s Turkey. Despite widely available anecdotal information based on post-disaster studies regarding its performance under earthquakes, robust quantitative data on the seismic behaviour of these structures were practically non-existent until quite recently, and are still somewhat limited. However, we are now able to confirm that hımış constructions do have intrinsic qualities that are very beneficial under seismic action. This paper aims to make a brief review of the current state of our knowledge on structural performance of hımış buildings under earthquake loading, with specific emphasis on infill/cladding techniques, connection details and energy dissipation characteristics

    Effects of surface sizing with starch on physical strength properties of paper

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    The main role of the surface sizing is to increase the strength of the paper surface and to bind particles such as fiber and pigments to paper surface. For this purpose, starch, animal glue, methyl cellulose, carboxymethyl cellulose, polyvinyl alcohol and wax emulsions can be used and many resins polymers can be used for some special purposes. Among these, the starch is the most frequently used one. This study was performed to determine the changes on strength and printing properties of sulfite base paper and vegetable parchment base paper with sizing by starch having a solid content of 10 % on the K-Coater laboratory type. According to the results of paper strengths and printing tests, it has been found that surface sizing with starch improves positively paper physical strength properties and printability

    Oral Papillomatosis in a Dog and its Therapy with Taurolidine

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    The efficacy of taurolidine on the treatment of oral papillomatosis in a 1-year-old Turkish Kangal dog was evaluated. Diagnosis of the papillomatosis was based on clinical signs, histopathological and immunohistochemical examinations. The dog received 45 mg/kg taurolidine intravenously every 3 days. Regression of papillomas started to be observed after the beginning of treatment, and complete resolution occurred after the fifth application
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