Effects of Rotation, Site, and Clone on the Chemical Composition of Populus Hybrids

Chemical content values were determined for three Populus clones grown on two dissimilar sites by component (wood, bark, and wood/bark specimens), tissue age (1-, 2- and 4-years-old), and rotation. The chemical content values obtained included extractives, holocellulose, alpha-cellulose, and lignin. In general, analysis of the data for the wood, bark, and wood/bark specimens indicated that: 1) wood was high in holocellulose and alpha-cellulose content compared to bark, 2) bark was high in lignin and extractive content values compared to wood, and 3) wood/bark chemical content values were between the values for the wood and bark specimens.The chemical content data were analyzed to identify: 1) significant differences between rotations by component (wood, bark, and wood/bark) for a given age, clone, and site, and 2) significant differences between sites for four-year-old wood, bark and wood/bark specimens of a given rotation, and clone. Statistical analyses indicated that significant differences existed among clones, sites, ages, and rotations. Within the wood, bark and wood/bark specimens, tissue age, rotation, and site influenced the chemical content values more than the parentage. Potential chemical yields derived from the three Populus hybrid clones investigated will depend on component, age, rotation, and site with limited parentage effects

Comparison of Selected Fuel and Chemical Content Values for Seven Populus Hybrid Clones

Fuel and chemical content values were determined for seven Populus clones by component (wood, bark, and wood/bark specimens) and tissue age (1 to 8 years old). The fuel and chemical content values obtained included: gross heat of combustion, extractives, holocellulose, alpha-cellulose, lignin, and ash. In general, analysis of the data for the wood, bark, and wood/bark specimens indicated that: 1) wood was higher in holocellulose and alpha-cellulose content than bark; 2) bark was higher in gross heat of combustion, lignin, extractive, and ash content values than wood; and 3) combined wood/bark fuel and chemical content values were usually between the individual values for the wood and bark.Statistical analyses indicated that significant differences existed within and among clones. Within the wood, bark, and wood/bark specimens, tissue age influenced the chemical content values more than the parentage. Potential chemical yields derived from the seven Populus hybrid clones investigated will depend on component and age with limited parentage effects

TSS-1R Mission Failure Investigation Board

Reasons for the tether separation during the Tethered Satellite System (TSS-1) Mission are investigated. Lessons learned are presented