Short-term H{\alpha} line variations in Classical Be stars: 59 Cyg and OT Gem

We present the optical spectroscopic study of two Classical Be stars, 59 Cyg and OT Gem obtained over a period of few months in 2009. We detected a rare triple-peak H$\alpha$ emission phase in 59 Cyg and a rapid decrease in the emission strength of H$\alpha$ in OT Gem, which are used to understand their circumstellar disks. We find that 59 Cyg is likely to be rapid rotator, rotating at a fractional critical rotation of $\sim$ 0.80. The radius of the H$\alpha$ emission region for 59 Cyg is estimated to be $R_d/R_*$ $\sim$ 10.0, assuming a Keplerian disk, suggesting that it has a large disk. We classify stars which have shown triple-peaks into two groups and find that the triple-peak emission in 59 Cyg is similar to $\zeta$ Tau. OT Gem is found to have a fractional critical rotation of $\sim$ 0.30, suggesting that it is either a slow rotator or viewed in low inclination. In OT Gem, we observed a large reduction in the radius of the H$\alpha$ emission region from $\sim$ 6.9 to $\sim$ 1.7 in a period of three months, along with the reduction in the emission strength. Our observations suggest that the disk is lost from outside to inside during this disk loss phase in OT Gem.Comment: 12 pages, 3 figures, Accepted for publication in Journal of Astrophysics and Astronomy. arXiv admin note: text overlap with arXiv:1602.0293

Design of permanent magnets to chaoize PM synchronous motors for industrial mixers

In this paper, the permanent magnet synchronous motor (PMSM) is used as the agitator because of its inherent advantages of high power density, high efficiency and maintenance-free operation. The effect of PM sizing on the performance of the chaotic motion of PMSM is discussed. Simulation as well as experimental results of the proposed mixer is presented to verify the effectiveness.published_or_final_versio

Destabilization control of a chaotic motor for industrial mixers

Industrial mixers are among the most expensive and ineffective equipment in food, drug, chemical and semiconductor industries. Chaotic mixing has been proposed to improve the energy efficiency and the degree of homogeneity using either mechanical or electrical means. This paper presents the destabilization control of the DC motor (the agitator) for industrial mixing processes through the pole placement technique which is more analytically accessible compared with time-delay control proposed before. Theoretical derivation and computer simulation are provided to illustrate the controllable chaotic motion. Moreover, the mixing effectiveness is experimentally verified by an acid-base neutralization reaction. © 2005 IEEE.published_or_final_versio

Chaoization of DC motors for industrial mixing

Conventional industrial mixing is ineffective, which consumes a lot of energy. In this paper, an effective mixing approach is proposed and implemented by using an electrical chaoization. Namely, a permanent-magnet dc motor, which acts as the agitator, is electrically chaoized by time-delay feedback control. It is identified that there are three adjustable control parameters: the torque parameter which induces chaotic motion, the speed parameter which adjusts the motion boundary, and the time-delay parameter which tunes the refreshing rate. Both computer simulation and experimental results are given to verify the proposed chaoization. Finally, realistic mixing of an acid-base solution is used to verify the effectiveness of the proposed chaotic mixing. © 2007 IEEE.published_or_final_versio

A novel chaotic-speed single-phase induction motor drive for cooling fans

This paper presents a novel chaotic-speed control of single-phase shaded-pole induction motor drives, especially for application to cooling fans. It is the firstly proposed and implemented chaotic-speed fan. Based on the d-q axis model of the shaded-pole induction motor drive, Poincaré mapping and hence bifurcation analysis are conducted to reveal the periodic and chaotic operations under different system parameters. Consequently, a chaotic-speed fan can be achieved by properly choosing either the motor's own parameters or the operation condition such as the frequency and amplitude of the applied voltage. Theoretical analysis, computer simulation and experimental results are given to testify the proposed chaotic-speed fan. © 2005 IEEE.published_or_final_versio

Comparison of the absolute and relative efficiencies of electroporation-based transfection protocols for Plasmodium falciparum.

BACKGROUND: Several electroporation protocols exist to transfect exogenous DNA into Plasmodium falciparum. To date, however, only a subjective analysis of their relative efficiencies has been reported. METHODS: A time-course of luciferase reporter expression is used to provide an objective quantitative analysis of the absolute efficiency of three electroporation techniques; direct electroporation of ring stage infected erythrocytes, preloading of erythrocytes and a novel "double-tap" protocol that combines both approaches. RESULTS: Preloading of erythrocytes shows a mean efficiency of 9.59 x 10(-6), some 5-180 fold more efficient than matched experiments utilizing the "double-tap" and direct electroporation of ring stage infected erythrocytes alone, respectively. CONCLUSION: Evidence presented here provides the first quantitative assessment of both the absolute and relative efficiencies of a key molecular tool used to study the biology and pathogenesis of this important human pathogen

Multilayer framework for vehicle-to-grid operation

In recent years, electric vehicles (EVs) have been widely accepted by general publics due to their low emissions. Particularly, those EVs which are able to be connected to power grid have earned lots of attention. In this paper, a multilayer framework is newly proposed for vehicle-to-grid operation. In this framework those gridable EVs can serve as resources to provide their capacity and energy service or as loads to be charged directly. The corresponding aggregator works as a smart controller for the framework, which is responsible for forming aggregations of gridable EVs and determining which vehicle to be a resource or a load. Cost-emission analysis is carried out based on this framework. Hence, operation cost and emissions can be reduced by using these gridable EVs. © Copyright 2011 IEEE - All Rights Reserved.published_or_final_versionThe 2010 IEEE Vehicle Power and Propulsion Conference (VPPC), Lille, France, 1-3 September 2010. In Proceedings of VPPC, 2010, p. 1-

A permanent-magnet double-stator integratedstarter-generator for hybrid electric vehicles

This paper presents a new permanent magnet double-stator integrated-starter-generator (ISG) for hybrid electric vehicles (HEVs). Compared with conventional PM electric machines, it has the advantage that currents of both the inner and outer stators produce electromagnetic torque and two air-gaps can deliver the output torque, thus improving the torque density and providing a high starting torque for cold cranking. Because of the nature of doublestator windings, the machine can flexibly change their connections, hence providing a constant output voltage over a wide speed range for battery charging. By using time-stepping finite element method (TS-FEM), the steady-state and dynamic performance of the machine is analyzed. Hence, due to the high starting torque and good controllability, this proposed ISG is desirable for HEVs application. A three-phase 22-pole 2 kW prototype is designed and built for experimentation verification. © 2008 IEEE.published_or_final_versio

Analysis of eddy-current loss in a double-stator cup-rotor PM machine

In this paper, a new double-stator cup-rotor permanent-magnet brushless DC (PMBDC) machine is proposed and analyzed. Since the machine structure is so unique while its operating principle is so distinct, a numerical field approach, namely the circuit-field-torque grid-model time-stepping finite-element method (CFT-GM-TS-FEM), is newly developed to analyze the steady-state and dynamic characteristics of the machine. Particularly, the analysis of eddy-current loss in both the PMs and iron core of the machine is conducted. Experimental results are given for verification. © 2008 IEEE.published_or_final_versio