Narrow Results

Based on the principle of exergy-economy, the equation for the annual total cost of the low-temperature pipeline is derived by analyzing the process of the transport, which can be used to discuss the effects of the pipe diameter and insulation thickness on the annual total cost. An approach of the synchro-design method for the low-temperature pipeline and its insulation is proposed. From the point of reducing the annual total cost, the calculating formulas of the low-temperature pipeline and insulation thickness are obtained.

Polyvinyl chloride (PVC) is widely used as insulator in electrical engineering especially as cable insulation sheaths. In order to improve the dielectric properties, polymers are mixed with ceramics. In this paper, PVC composites with different weight percentages 2 wt.%, 5 wt.%, 8 wt.% and 10 wt.% were prepared and investigated. Loss index (${𝜀}^{″}$) and dielectric constant (${𝜀}^{\prime }$) have been measured using an impedance analyzer RLC. Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) equipped with energy dispersive X-ray (EDX) have been used as characterization techniques. The incorporation of BaTiO₃ does not modify the crystallinity and the morphology of the PVC but reduces the space charges, therefore the dielectric losses. The frequency response analysis has been followed in the frequency ranges (20–140 Hz and 115–1 MHz). Relaxation frequencies have been evaluated in each frequency range. Experimental measurements have been validated using Cole–Cole’s model. Experimental results show well that BaTiO₃ as a filler improves the dielectric properties of PVC.

With the miniaturization and integration of electronic devices, a liquid zoom lens that has the characteristics of low cost, small size and good adjustability has wide applicability in the fields of cameras, mobile phones, projection, and medical equipment. In this paper, we first describe the principle of electrowetting and electrowetting based liquid lenses. Then we present an electrowetting lens prototype utilizing a single hydrophobic insulating layer Cytop was used as the hydrophobic insulation layer in our new device. When the applied voltage is 40V, the contact angle changes reversibly from 133° to 99°; the associated focal length change is from 5cm to infinity. Our design delivers low driving voltage and power consumption via a simple production process. Due to it's compact size it be readily incorporated in small portable optical products.