2,137 research outputs found

    Pulsed Corona Discharge for Oxidation of Gaseous Elemental Mercury

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    Positive pulsed corona discharge has been applied for the oxidation of gaseous elemental mercury (Hg0) from a simulated flue gas. The oxidation of Hg0 to HgO and HgCl2 can significantly enhance the mercury removal from flue gas. At a gas condition of O2 (10%), H2O (3%), and N2 (balance), Hg0 oxidation efficiency of 84% was achieved at an input energy density of 45 J/l. The presence of NO, however, hinders Hg0 oxidation due to the preferential reaction of NO with O and O3. On the contrary, SO2 shows little effect on Hg0 oxidation due to its preferential reaction with OH. It has been also observed that the HCl in gas stream can be dissociated to Cl and Cl2 and can induce additional Hg0 oxidation to HgCl2

    Economic Routing of Electric Vehicles using Dynamic Pricing in Consideration of System Voltage

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    There is a growing market for electric vehicles (EVs) in recent years. Due to this, many studies on electric vehicles are in progress and research on charging operations for EVs are especially active. Recent research trends on electric vehicle routes rely on the stochastic modelling of various factors such as convenience of a user&rsquo s point of view, charging station (CS), location, destination, and so on. In this paper, a charging control scheme for electric vehicles is proposed from the point of view of the system operators rather than the user. From a user&rsquo s point of view, the EV route can be set up directly, but it is difficult for the system operator to directly participate in the route of the EV. In this paper, a method is proposed to indirectly change the route of the EV by changing the charging cost through real-time dynamic pricing, in order to prevent risks in the system operation due to voltage fluctuations in the system. With dynamic pricing, the voltage of the system is kept within a stable range, and the EV user sets the route with an economic benefit. The proposed scheme is verified through Dijkstra&rsquo s algorithm and a control strategy via a simulation model using MATLAB. Document type: Articl

    Enhanced overall efficiency of GaInN-based light-emitting diodes with reduced efficiency droop by Al-composition-graded AlGaN/GaN superlattice electron blocking layer

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    AlxGa1-xN/GaN superlattice electron blocking layers (EBLs) with gradually decreasing Al composition toward the p-type GaN layer are introduced to GaInN-based high-power light-emitting diodes (LEDs). GaInN/GaN multiple quantum well LEDs with 5- and 9-period Al-composition-graded AlxGa1-xN/GaN EBL show comparable operating voltage, higher efficiency as well as less efficiency droop than LEDs having conventional bulk AlGaN EBL, which is attributed to the superlattice doping effect, enhanced hole injection into the active region, and reduced potential drop in the EBL by grading Al compositions. Simulation results reveal a reduction in electron leakage for the superlattice EBL, in agreement with experimental results. (C) 2013 AIP Publishing LLC.open1133sciescopu

    Morphological changes of the lateral meniscus in end-stage lateral compartment osteoarthritis of the knee.

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    OBJECTIVE: The aim of this study was to evaluate the morphological changes of the lateral meniscus in end-stage lateral compartment osteoarthritis (OA) of the knee. METHODS: One hundred fifty-eight knee joints from 133 patients that subsequently underwent total knee joint arthroplasty from January 2008 to December 2009 were enrolled. There were 26 men and 107 women. Their ages ranged from 56 to 81 (mean 67.4 + 6.5 years). All study participants had complete obliteration of the lateral joint space identified by weight-bearing radiography. Meniscal position was assessed by measuring meniscal subluxation and meniscal height. The meniscal morphology was assessed using a modification of the whole-organ magnetic resonance imaging score (WORMS). The frequency of different meniscal morphology and their respective positions was calculated. RESULTS: The predominant type (42.4%, 53.8% and 52.5% in the anterior horn, mid-body and posterior horn, respectively) of abnormal meniscal morphology was a complete maceration/destruction or complete resection. The anterior horn of non-macerated lateral meniscus was more subluxed than that of the non-macerated medial meniscus in patients with lateral OA. CONCLUSION: This study suggests that the lateral meniscus in persons with end-stage lateral OA are mostly macerated or destroyed. Also, unlike isolated end-staged medial compartment OA, the anterior horn of the lateral meniscus in isolated end-stage lateral OA is commonly affected. Copyright 2011 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved
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