A Double-Bridge Channel Shape of a Membraneless Microfluidic Fuel Cell

A double-bridge shape is proposed as a novel flow channel cross-sectional shape of a membraneless microfluidic fuel cell, and its electrochemical performance was analyzed with a numerical model. A membraneless microfluidic fuel cell (MMFC) is a micro/nano-scale fuel cell with better economic and commercial viability with the elimination of the polymer electrolyte membrane. The numerical model involves the Navier–Stokes, Butler–Volmer, and mass transport equations. The results from the numerical model were validated with the experimental results for a single-bridge channel. The proposed MMFC with double-bridge flow channel shape performed better in comparison to the single-bridge channel shape. A parametric study for the double-bridge channel was performed using three sub-channel widths with the fixed total channel width and the bridge height. The performance of the MMFC varied most significantly with the variation in the width of the inner channel among the sub-channel widths, and the power density increased with this channel width because of the reduced width of the mixing layer in the inner channel. The bridge height significantly affected the performance, and at a bridge height at 90% of the channel height, a higher peak power density of 171%was achieved compared to the reference channel.

ANALISIS PERFORMANSI TURBIN PROPELLER OPEN FLUME TIPE TC 60 KAPASITAS 100 W TERHADAP PERUBAHAN DEBIT

The TC 60 open flume propeller turbine is an example of a pico-hydro-based fluid engine. The potential of the TC 60 open flume propeller turbine can be maximized by paying attention to the flow rate. This study aims to analyze the performance of the TC 60 open flume propeller turbine performance which is influenced by changes in discharge. The method used is descriptive analysis method. The turbine performance testing was carried out at the CV Cihanjuang Inti Teknik laboratory in Cimahi. Turbine testing begins by making 9 discharge ranges from 1.28 litre/sec until 4.85 litre/sec then testing each of these flows. Power testing is carried out using a lamp load of 10 to 100 watts. The results showed the effect of changes in discharge on the power generated by the turbine. The maximum power produced in this study is 74 watts at a discharge flow of 4.85 litre/sec with a load of 70 watts. The lowest discharge to be able to move the turbine is 1.28 litre/ sec. The results of the technical feasibility analysis on civil buildings in CV Cihanjuang Teknik show that the TC 60 open flume propeller turbine is feasible to use by considering the design of the discharge, head and channel shape of civil buildings. Keywords: discharge, picohydro, propeller turbine, performance

Channel Shape Effects on Device Instability of Amorphous Indium–Gallium–Zinc Oxide Thin Film Transistors

Channel shape dependency on device instability for amorphous indium–gallium–zinc oxide (a-IGZO) thin film transistors (TFTs) is investigated by using various channel shape devices along with systematic electrical characterization including DC I-V characeristics and bias temperature stress tests. a-IGZO TFTs with various channel shapes such as zigzag, circular, and U-type channels are implemented and their vertical and lateral electric field stress (E-field) effects are systematically tested and analyzed by using an experimental and modeling study. Source and drain (S/D) electrode asymmetry and vertical E-field effects on device instability are neglibible, whereas the lateral E-field effects significantly affect device instability, particularly for zigzag channel shape, compared to circular and U-type TFTs. Moreover, charge trapping time (τ) for zigzag-type a-IGZO TFTs is extracted as 3.8 × 104, which is at least three-times smaller than those of other channel-type a-IGZO TFTs, hinting that local E-field enhancement can critically affect the device reliability. The Technology Computer Aided Design (TCAD) simulation results reveal the locally enhanced E-field at both corner region in the channel in a quantitative mode and its correlation with hemisphere radius (ρ) values.