Papers by Keyword: Environment Effects

Abstract: In this short review paper, the physical and mechanical properties of acacia wood, poly lactic acid (PLA) and polyhydroxyalkanoates (PHA) were analyzed. Existing factors that affect the mechanical properties of natural fiber composites were investigated and identified. By knowing these factors, a possibility and potentiality in implementing the natural acacia wood reinforced material with hybrid polymer were discussed. It was found that the acacia wood had the potential to re-condition soil and have the potential to become reinforced materials in hybrid polymer composites. In addition, using fully biodegradable polymer such as PLA and PHA made it sustainable and environmentally friendly.

Abstract: Based on the long-term monitoring data of Donghai Bridge, span length changes of the main channel of the bridge was analyzed from the expansion joint displacement data monitored，and the correlation between the span changes and the environmental factors, which are temperature and wind load, was analyzed. Results show that temperature is the main factor influencing the span change, while the correlation between span changes and wind load is weak so can be ignored. The linear regression model established between span changes and the structure effective temperature can be used to estimate the interval of bridge span changes and examine the correctness of the expansion joint data monitored. Moreover, the regressive model of accumulated expansion joints displacement and time history can provide valuable information for design, maintenance and replacement of the expansion joints.

Abstract: Micro/nano handling is an important enabling technology for future manufacturing. In the micro scale, adhesion is a severe problem for efficient and accurate handling tasks. The cause of the adhesion is largely from the microforces, namely van der Waals, electrostatic and capillary forces. Those forces, however, are functions of ambient environmental conditions. This paper exams two important ambient environment parameters in normal micro/nano handling environment: temperature and humidity, in both theoretical analysis and experimental studies. A short guideline for microhandling with temperature and humidity consideration is suggested based on the studies.