A robust and reliable gas sensing device is considered as a convenient and practical solution for gas concentration monitoring that has become a mandatory requirement in different field of applications. For in situ hazardous gases detection, a mixed-potential type gas sensor has been regarded as a promising solid-state gas sensor. For the past three decades, there has been a significant progress in achieving high performance in mixed-potential type sensors. Therefore, this review is focused on reporting the development of mixedpotential type gas sensors with combined yttria-stabilized zirconia (YSZ) as the base solid electrolyte material and various classes of electrode materials for their potential utilization as a high-performance sensing electrode. The underlying sensing mechanism of a mixed-potential type YSZ-based sensor is elaborated here in detail. Transformation in design and configuration of this type of sensor is also covered in this report. In addition, recent progresses on mixed-potential type gas sensors development for detection of several target gases, such as carbon monoxide, hydrocarbons, nitrogen oxides, hydrogen, and ammonia, are reviewed. Strategies to improve the sensing characteristic, particularly gas sensitivity and selectivity, are also reported. Based on the understanding of the fundamental sensing mechanism and the requirements for high-performance gas sensors, challenges and future trends for this type of gas sensor development are discussed.

Using infrared irradiation to heat an industrial brass (Cu–Zn alloy) disk in moderate vacuum, ZnO nanobelts were directly prepared on a Si substrate. The nanobelts had a single-crystal hexagonal structure and grew along the [0001] direction. The nanobelts had two distinct widths along their entire length. Photoluminescence measurement showed that the nanobelts had an intensive near-band ultraviolet emission at 379 nm. Large-area growth and high quality indicate that the prepared ZnO nanobelts have potential application in optoelectronic devices.

Adjustable sit-stand workstations, which are designed to allow workers to sit and stand autonomously while working, were examined to identify the effects on workers' musculoskeletal discomfort, alertness and performance. Twenty-four healthy subjects participated in the study. The subjects were required to do an English transcription task for 150 min under the following conditions: 1) sitting at standard workstations (Standard), 2) sitting on a chair with the work surface elevated to standing position (High-chair) and 3) a combination of 10-min sitting and 5-min standing with the same setting as that in the high-chair condition (Sit-stand). The subjective musculoskeletal discomfort scores indicated that High-chair and Sit-stand resulted in relatively higher discomfort levels than the Standard condition. Although the ratio between low-frequency (0.04-0.15 Hz) and high-frequency (0.15-0.4 Hz) components of heart rate variability (LF/HF ratio) in Sit-stand was higher than that in other conditions, there were no significant differences in subjective sleepiness among the three conditions. As for work performance, there was a tendency to be steadily high under the Sit-stand condition compared with other conditions, but not a significant difference. This study revealed that although the use of sit-stand workstations can contribute to keeping workers' arousal level steady, it has an adverse effect in light of musculoskeletal discomfort.

We examined the influence exerted, through disuse of the hindlimb, on the collagen fibres of the achilles tendon in rats. With disuse the body mass decreased by 28%, and the mass of soleus muscle decreased by 20%. A decrease in the surface area and diameter was observed in the experimental group when compared to the control group. A histogram of the collagen fibres showed a decrease of the thick fibres in the experimental group. The maximum surface area of collagen fibres in the experimental group was seen to be only 43% of that of the control group. These results showed a decrease in the thickness of the collagen fibres of the achilles tendon through disuse. This seemed to suggest that resistance to tension is decreased by disuse.