Materials Engineering of Violin Soundboards by Stradivari and Guarneri.

We investigated the material properties of Cremonese soundboards using a wide range of spectroscopic, microscopic, and chemical techniques. We found similar types of spruce in Cremonese soundboards as in modern instruments, but Cremonese spruces exhibit unnatural elemental compositions and oxidation patterns that suggest artificial manipulation. Combining analytical data and historical information, we may deduce the minerals being added and their potential functions-borax and metal sulfates for fungal suppression, table salt for moisture control, alum for molecular crosslinking, and potash or quicklime for alkaline treatment. The overall purpose may have been wood preservation or acoustic tuning. Hemicellulose fragmentation and altered cellulose nanostructures are observed in heavily treated Stradivari specimens, which show diminished second-harmonic generation signals. Guarneri's practice of crosslinking wood fibers via aluminum coordination may also affect mechanical and acoustic properties. Our data suggest that old masters undertook materials engineering experiments to produce soundboards with unique properties.

Chemical composition and anti-inflammatory activity of Chamaecyparis obtusa f.formosana wood essential oil from Taiwan.

Chamaecyparis obtusa Siebold & Zucc. f.formosana Hayata (Cupressaceae) is one of the treasured conifers in Taiwan. In this study, the wood essential oil of the species was extracted and its anti-inflammatory bioactivities analyzed. The composition analysis of the essential oil yielded a total of 57 compounds with alpha-terpineol (19.4%), tau-muurolol (16.9%), borneol (16%), and alpha-cadinol (10.9%) predominating. The anti-inflammatory assays of the essential oil suggest that C obtusa f. formnosana wood oil has no cytotoxicity, and was capable of inhibiting the expressions of tumor necrosis factor (TNF-alpha), IL-6, IL-1, pro IL-1beta, NO, iNOS, and NLRP3 in murine macrophage cells. It was unable, however, to inhibit the expression of COX-2. Further investigation of the effect of the essential oil on the cellular signal transduction indicated that it was capable of inhibiting ERKI/2, JNKI/2 and p38; it also showed excellent inhibition against ROS. Thus, the overall results indicated that C. obtusa f.formnosana wood oil had very good anti-inflammatory efficacies.

Effects of manufacturing conditions on the adsorption capacity of heavy metal ions by Makino bamboo charcoal.

The objective of this study was to investigate the effects of manufacturing conditions on the adsorption capacity of heavy metal ions by Makino bamboo charcoal. Results show that the specific surface area and iodine number of bamboo charcoal activated at 900 degrees C were larger than those of bamboo charcoal activated at 800 degrees C. The specific surface area of bamboo charcoal activated at 800 degrees C by carbon dioxide was larger than that of charcoal activated by steam. However, a contrary result was observed when the activation temperature was 900 degrees C. The total volume and proportion of micropores in bamboo charcoal activated by carbon dioxide were greater than those in the other sample groups. However, the total volume and bulk volume of meso- and macropores, and average pore diameter for bamboo charcoal activated by steam were greater than those in the other sample groups. Using 5g bamboo charcoal (10-30 mesh) with a soaking time of 24h, a better adsorption effect on Pb2+ (100%), Cu2+ (100%), and Cr3+ (88-98%) was found. However, medium frequencies were observed for the adsorption of Cd2+ (40-80%) and Ni2+ (20-60%). Very limited adsorption of As5+ was detected in this study. For the same charcoal grain sizes, the adsorption capacity of 0.5g of charcoal was better than that of 0.1g. The improved adsorption effect of the sample group activated by steam was compared with the sample group activated by carbon dioxide.