Sequoia wood

Redwood and Sequoia Sequoia Wood Lumber, insect repellant... 

Besides these papers and the investigations of Wiedemann on 2000 year old sequoia wood [48] or ancient paper and its plant origin [104] (see below) no further publications were found in the literature. The present authors are sure that an interesting and stimulating field of research is waiting here for DSC and... 

In Quercus alba the rays represent 28% of the wood volume and in other oak species 19-32% in most other hardwoods the rays occupy about 15% but only 8% of the wood volume in the conifer Sequoia sempervirens (13). The large rays of the oak are so spaced and numerous that a molecule of water diffusing through the side of a barrel must cross five or more large rays if it exits on a straight path or follow a much extended path if it is to go around the rays interposed. These large rays no doubt contribute to the strength and bendability of oak as well as to its dimensional stability and relative impermeability. 

Figure 33 Structures of (a) 0s04 NC6H13 and (b) (0s04)2,N4C6H12 (reproduced with permission from W. P, Griffith, A. C. Skapski, K. A. Woode and M, J. Wright, Inorg. Chim. Acta, 31, L413, copyright 1978 Elsevier Sequoia SA)631...

Perhaps the most extensive area of research in simple pretreatment systems to enhance the weathering properties of wood has involved application of inorganic salt solutions. Much of the early work in this field was undertaken at the U.S. Forest Products Laboratory in Madison, Wisconsin and was aimed at improving the performance of transparent finishes. Black [25] described an experimental chromate-based wood finish and Black and Mraz [26] discovered that both acid and ammoniacal-copper chromate treatments significantly improved the performance of clear finishes on western red cedar, redwood (Sequoia sempervirens), and Douglas fir plywood. Later research [27] demon-... 

As the relative proportions of the woody components vary only within narrow ranges for common commercial species, the EMCs at a given relative humidity and temperature are closely similar for these woods. However, at high relative humidities deviations from mean values can appear. Shubin s data (1990) show, for instance, that at 95% relative humidity the EMC at 42.4°C ranges from 22% for a pine to 33% for an oak. Hoadley (1980) notes that in species with a high extractives content, such as redwood (Sequoia sempervirens) and mahogany (Swietenia mahogani), the fibers remain saturated at 22%-24% moisture content, whereas birch (Betula spp.) may have a moisture content up to 35% at fiber saturation. 

Durability (eventually for several thousand years) wood (sequoia gigantua) skin and hair (mammoth), bones (dino -saurs) and large shells. 

Wood Species. The following types of conunercial lumber were obtained from Riverside Lumber Company in New Orleans, LA spruce, Picea sp, yellow birch, Betula alleghaniensis Britton, northern red oak, Quercus rubra L. redwood. Sequoia sempervirens (D. Don) mid Alaska yellow cedar, Chamaecyparis nootkatensis (D. Don). 

D-Pinitol (lD-3-O-methyl-cA/ro-inositol) is the most widely distributed inositol ether. It has been found in six gymnosperm families and 13 angiosperm families (137). In gymnosperms, it is a component of the resin of Pinus lamber-tiana (see 137) the bark of Picea abies, Pinus nigra (71), Pinus halepensis, and Schinus molle (72) (where its content has been determined as a function of season) the cambial sap of Pinus silvestris, Picea abies, and Abies alba (114) and the wood of Pinus spp. (see 6, 137) and Sequoia sempervirens (153). It also occurs in various plant parts, including latex and wood Acacia mollissima), of angio-sperms (see 137). 

Wiedemann [130] used samples of redwood Sequoia sempervirens), balsa Ochroma pyramidale/lagopus), quebracho bianco Aspidosperma quebracho-bianco) and beech wood (Fagus spec.) to determine the mechanical properties of wood by means of TMA and DSC. Flexure measurements as depicted in Figure 23 show different, highly reproducible onset temperatures for breakdown in the chosen samples from the very light balsa wood to the very hard South American quebracho bianco and - for comparison - bamboo. TMA together with DSC results indicates that such breakdowns take place only after the complete decomposition of cellulose. 

---