Browsing by Author "Chou, Yen-I"

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A lighting mechanism for flat electron emission lamp
(2009-03-02)
Li, Jung-Yu
;
Chen, Shih-Pu
;
Li, Chia-Hung
;
Lin, Yi-Ping
;
Chou, Yen-I
We propose a lighting mechanism for generating uniform planar light. The device integrates electron beams induced by gas discharge with cathodoluminescence at the anode, where the spectra of the emitted light depend entirely on the phosphor materials coated on the anode. Consequently, ultraviolet is not required and the usage of mercury can be avoided. In addition, the features of double-side lighting, transparency, and gray-scale images indicate that the flat electron emission lamp might become potential candidate for the next generation green lighting source.
Discharge and photo-luminance properties of a parallel plates electron emission lighting device
(2011-01-03)
Li, Chia-Hung
;
Liu, Ming-Chung
;
Chiang, Chang-Lin
;
Li, Jung-Yu
;
Chen, Shih-Pu
The gas discharge and photo-luminance properties of a planar lighting source featuring highly uniform light emission and mercury-free design were studied. The current density-voltage characteristics and the associated gas discharge of the devices operating with the values of the ratio of electric field to gas pressure (E/p) between 4.3 kV/Torr-cm and 35.7 kV/Torr-cm indicate that the width of the cathode fall extends over the entire gap between the two electrodes and the device is mostly in the obstructed discharge regime. The optical emission analysis confirmed the electron collision-induced gas emissions and strong effect of gas pressure on the phosphor emission when operated at constant current density, both are indicative of the primary roles played by the electron energy. (C)2011 Optical Society of America
Surface modification of nano-porous anodic alumina membranes and its use in electroosmotic flow
(2010-03-04)
Chen, Yu-Feng
;
Hu, Yi-Hsin
;
Chou, Yen-I
;
Lai, Shih-Ming
;
Wang, Chi-Chuan
This study examines the surface-modification effects of porous anodic alumina membranes (PAAMs) on the performance of electroosmotic (EO) pumping. The modifications include using H(2)O(2)-pretreated, and followed by 3-aminopropyltriethoxysilane (APS) or 3-mercaptopropyl trimethoxysilane (MPTS) sol-gel solutions to functionalize the surface of PAAM for achieving higher surface charge density. The surface-modified membranes are analyzed by average pore size, contact angle, and FTIR measurements. The results show that APS and MPTS are successfully coated on the surface of PAAMs. The characteristics (e.g., total current, maximum pressure, and normalized flow rate) of the EO pumps with these surfacemodified PAAMs are investigated. The comparison results of total current at zero time confirmed that the surface charge density of the surface-modified PAAM has been increased. Consequently, the maximum normalized flow rate of EO pump with the APS- and MPTS-coated PAAM are higher than that with the bare PAAM in DI water but without buffer control methods. The convection current of EO flow is also investigated, and the results show that its contribution to total current is around 11% and thus cannot be ignored for EO flow with nano-size channels. (C) 2009 Elsevier B.V. All rights reserved.
Water permeation analysis on gas diffusion layers of proton exchange membrane fuel cells for Teflon-coating annotation
(2010-01-15)
Chou, Yen-I
;
Siao, Zih-Yuan
;
Chen, Yu-Feng
;
Sung, Lung-Yu
;
Yang, Wen-Mei
This study presents an analysis of water permeation of a polytetrafluoroethylene (PTFE)-coated gas diffusion layer (GDL) to determine the influence of hydrophobic treatment on the GDL for diagnosis of water flooding. It is found that the behaviour of water drainage is controlled by the pore configuration instead of the hydrophobicity in GDL. Better water drainage is achieved by the action of the Teflon coating in modulating the GDL pore configuration to give both a larger average pore size and a wider distribution of pore size. The results show that water penetration through the GDL must overcome a threshold surface tension defined by the largest pore range. A 30 wt.% PTFE coating of a GDL is shown to generate a satisfactory pore configuration, explaining the improved cell polarization performance with a lower driven pressure (similar to 1.91 kPa) and a higher rate of water drainage. (C) 2009 Elsevier B. V. All rights reserved.