Effect of Opening Size on Wind-Driven Cross Ventilation

The opening size on indoor airflow is important to the ventilation of building because various size openings change the ventilation performance for building. Therefore, the objective of this study is to investigate the effect of opening size on indoor airflow characteristics of naturally ventilated building model. The numerical simulation with steady RANS equations was used. A total of six different opening ratios, namely 4:1, 2:1, 1:1, 1:2, 4:9 and 1:4 were considered in this study. The results of mesh independence study and model validation were also in good agreement with previous study. The simulation results show that velocity and pressure of the indoor air, ventilation rate, and pressure coefficient are highly dependent on the opening ratio. The velocity and pressure contour indicate that the lower the opening ratio, the higher the velocity and subsequently lower pressure inside the building. In addition, the pressure coefficient and ventilation rate are also increased as the opening ratio decreases. Besides, the results indicate that percentage increase in ventilation rate of opening ratio 4:1 and 2:1, 2:1 and 1:1, and 1:1 and 1:2 is higher than those of opening ratio for 1:2 and 4:9, 4:9 and 1:4. The study concluded that pairing a large outlet and small inlet leads to increase in better ventilation rate for building

Process Integration and Interconnection Design of Passive-Matrix LED Micro-Displays With 256 Pixel-Per-Inch Resolution

A 0.28-inch InGaN-based blue micro-LED display with 256 pixel-per-inch resolution and a pitch of 100 μm was successfully fabricated in this study. A thick Ti/Al/Ti/Au interconnection metal was deposited on the n-type gallium nitride (n-GaN) region to reduce the interconnection resistance. The micro-LED array with interconnection metal exhibits better electrical property consistency as compared with that of the traditional one. The output power, forward voltage, and external quantum efficiency of micro-LED, which measured under 1-mA current injection with the full lighting mode, are 0.8 mW, 3.0 V, and 10%, respectively. This technique has the potential to integrate InGaN-based LEDs with quantum dots for full-color applications

Tunability of p- and n-channel TiOx thin film transistors

To acquire device-quality TiOx films usually needs high-temperature growth or additional post-thermal treatment. However, both processes make it very difficult to form the p-type TiOx even under oxygen-poor growth condition. With the aid of high energy generated by high power impulse magnetron sputtering (HIPIMS), a highly stable p-type TiOx film with good quality can be achieved. In this research, by varying the oxygen flow rate, p-type γ-TiO and n-type TiO2 films were both prepared by HIPIMS. Furthermore, p- and n-type thin film transistors employing γ-TiO and TiO2 as channel layers possess the field-effect carrier mobilities of 0.2 and 0.7 cm2/Vs, while their on/off current ratios are 1.7 × 104 and 2.5 × 105, respectively. The first presented p-type γ-TiO TFT is a major breakthrough for fabricating the TiOx-based p-n combinational devices. Additionally, our work also confirms HIPIMS offers the possibility of growing both p- and n-type conductive oxides, significantly expanding the practical usage of this technique