Southern pine (Pinus sp.) wood cubes were treated with ACQ solutions with wax modification and post-treated at 70 °C for 10 h with hot air circulation. The effects of wax concentrations in ACQ-treated southern pine on its dimensional stability and copper leaching performance were investigated. The ACQ/wax-treated wood exhibited improved water resistance during the water soak process. The testing of swelling and shrinkage performance of the treated wood showed that samples with a higher percentage of wax had higher resistance to water swelling and shrinkage. The samples with a lower percentage of wax addition had only a slight effect on the moisture swelling and shrinkage resistance. As a result, copper leaching from ACQ/wax-treated wood with a 2% wax concentration was reduced to a lower level compared to ACQ-treated wood. When the proportion of wax in ACQ preservative was less than 1%, a higher percentage of copper was leached from treated wood.

Emotion recognition can be helpful in many fields such as elderly healthcare. Existing emotion recognition approaches are usually based on wearable sensors or computer vision analysis, which are intrusive or inconvenient to use. In recent years, radio frequency identification (RFID) has been exploited to monitor physiological signs (e.g., respiration and heartbeat) of users in a contactless and convenient way. Motivated by such progresses, we conduct an experimental study on recognizing the emotion of users with commercial RFID devices. We propose Free-EQ, an emotion recognition framework which first extracts respiration-based features and heartbeat-based features from RFID signals and then uses these features to train a classifier to recognize different emotions of a target user. Experiments on commercial RFID hardware show that Free-EQ can distinguish different emotions with relatively high accuracy.

In order to improve the leaching resistance of active ingredient-copper in ammoniacal copper quat-type D (ACQ-D) treated Chinese fir (Cunninghamia lanceolata Hook.), microwave post-treatments were carried out. The percentages of leached copper from ACQ-D treated Chinese fir with different microwave post-treatments were obtained after leaching tests by analyzing the copper retention in treated wood. The fixation mechanism of copper in the treated wood was determined with the help of SEM and FTIR spectra, while the valence conversion of copper after microwave post-treatments was studied by UV spectroscopy. Our experimental results show that the percentage of leached copper was reduced significantly after microwave post-treatment over time. This development was reinforced by allowing even more time for the treatment as well as with an increase in the power of microwave post-treatment. The leaching resistance of copper in wrapped samples was better than that in unwrapped samples, which is attributed to the combined effects of temperature and moisture content. Compared with air-dried samples, the valence conversion in the samples with microwave post-treatments changed slightly, which demonstrates that microwave post-treatments cannot impair the natural decay resistance of ACQ-D treated wood. SEM and FTIR spectra showed the presence of crystal particles formed by chemical reactions between copper and wood ingredients in wood cell walls and wood pits. Only a small amount of copper reacted with cellulose, while lignin and hemicellulose were the major bonding sites for copper in wood. Given the experimental results of mechanical properties, microwave post-treatments had a slight effect on the compression strength parallel to the grain and on the crystallinity of ACQ-D treated Chinese fir.

Southern yellow pine (Pinus sp.) wood cubes were vacuum-pressure treated with nano-SiO2 solution and different concentrations of amine copper quaternary (ACQ)/wax (0.5%, 2.5%, and 5.0% wax)-modified solutions. The effects of wax concentration and nano-SiO2 addition on water absorption, air drying shrinkage, and moisture swelling stabilities were investigated. The results showed that during the whole process of water absorption and air drying shrinkage, better stability of nano-SiO2 modified ACQ-treated wood could only be obtained with the ratio of wax addition equal to 2.5%. However, the best moisture swelling resistance was found in the samples modified with the highest wax addition (5.0%). Both wax and nano-SiO2 could be useful for keeping the dimensional stability of the treated wood.

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