Stacking-fault-free and planar defect (twinning plane)-free In-catalyzed Si nanowires (NWs) are essential for carrier transport and nanoscale device applications. In this article, In-catalyzed, vertically aligned, and cone-shaped Si NWs on Si(111) were grown successfully, in the vapor–liquid–solid (VLS) mode. In particular, the influences of substrate temperature (T S) and cooling rate (ΔT S/Δt) on the formation of planar defects, twinning planes along the [112] direction, and stacking faults in Si NWs were investigated. When T S was decreased from 600 °C to room temperature at a rate of 100 °C/240 s after Si NW growth, twinning plane defects perpendicular to the substrate and along different segments of (111)-oriented Si NWs were observed. Finally, one simple model was proposed to explain the stacking fault formation as well as Si NW length limitation due to the In-nanoparticle (In-NP) migration, and root causes of the twinning plane defects in the Si-NWs.

Decreasing the contact angle between In NDs and the Si substrate helps to grow vertically aligned Si NWs with a diameter of 18 nm.

The most effective way of preventing motor vehicle accidents caused by drowsy driving is through a better understanding of drowsiness itself. Prior research on the detection of symptoms of drowsy driving has offered insights on providing drivers with advance warning of an elevated risk of crash. The present study measured back and sitting pressures during a simulated driving task under both high and low arousal conditions. Fluctuation of time series of center of pressure (COP) movement of back and sitting pressure was observed to possess a fractal property. The fractal dimensions were calculated to compare the high and low arousal conditions. The results showed that under low arousal (the drowsiness state) the fractal dimension was significantly lower than what was calculated with high arousal. Accumulated drowsiness thus contributed to the loss of self-similarity and unpredictability of time series of back and sitting pressure measurement. Drowsiness further reduces the complexity of the posture control system as viewed from back and sitting pressure. Thus, fractal dimension is a necessary and sufficient condition of a decreased arousal level. It further is a necessary condition for detecting the interval or point in time with high risk of crash.