NC State
  • Researchpp 265269Alma, M. H., Ertaş, M., Nitz, S., and Kollmannsberger, H. (2007). "Chemical composition and content of essential oil from the bud of cultivated Turkish clove (Syzygium aromaticum L.)," BioRes. 2(2), 265-269.AbstractPDF
    In this study, clove bud oil, which was cultivated in the Mediterranean region of Turkey, was provided from a private essential oil company in Turkey. Essential oil from clove (Syzygium aromaticum L.) was obtained from steam-distillation method, and its chemical composition was analyzed by GC and GC-MS. The results showed that the essential oils mainly contained about 87.00% eugenol, 8.01% eugenyl acetate and 3.56% β-Caryophyllene. The chemical composition of the Turkish clove bud oil was comparable to those of trees naturally grown in their native regions.
  • Researchpp 270-283Pérez, J. M., Rodríguez, F., Alonso, M. V., Oliet, M., and Echeverría, J. M. (2007). "Characterization of a novolac resin substituting phenol by ammonium lignosulfonate as filler or extender," BioRes. 2(2), 270-283.AbstractPDF
    In this work two types of lignin-novolac resins have been formulated, partially substituting phenol by softwood ammonium lignosulfonate as filler or extender (methylolated) to study the viability of that substitution when resins will be employed as adhesives in textile felts. A commercial novolac resin was used as reference. Free phenol, free formaldehyde, water content, softening point, and flow distance values were determined in all cases to verify whether the material fulfills specifications. In addition, FTIR and NMR spectroscopic techniques were employed for the characterization of three resins samples tested to discuss their structural differences and similarities. The results obtained have shown that the substitution proposed is feasible from the point of view of the resins synthesis to get the pre-polymer.
  • Researchpp 284-295Altaner, C., Knox, J. P., and Jarvis, M. C. (2007). "In situ detection of cell wall polysaccharides in sitka spruce (Picea sitchensis (Bong.) Carrière) wood tissue," BioRes. 2(2), 284-295.AbstractPDF
    Wood cell wall polysaccharides can be probed with monoclonal antibodies and carbohydrate-binding modules (CBMs). Binding of monoclonal antibodies to β-1-4-xylan, β-1-4-mannan, β-1-3-glucan, and α-1-5-arabinan structures were observed in native Sitka spruce (Picea sitchensis (Bong.) Carrière) wood cell walls. Furthermore CBMs of different families, differing in their affinities for crystalline cellulose (3a) and amorphous cellulose (17 and 28), were shown to bind to the native wood cell walls with varying intensities. Resin channel forming cells exhibited an increased β-1-4-xylan and a decreased β-1-4-mannan content. Focusing on severe compression wood (CW) tracheids, β-1-3-glucan was found towards the cell lumen. In contrast, α-1-5-arabinan structures were present in the intercellular spaces between the round tracheids in severe CW, highlighting the importance of this polymer in cell adhesion.
  • Reviewpp 296-331Hubbe, M. A. (2007). "Flocculation and redispersion of cellulosic fiber suspensions: A review of effects of hydrodynamic shear and polyelectrolytes," BioRes. 2(2), 296-331.AbstractPDF
    Cellulosic fibers in aqueous suspensions are subject to flocculation effects that involve two contrasting scales of dimension. The net effect of flocculation determines how uniformly fibers can become formed into a sheet during the manufacture of paper. At a macroscopic level, the highly elongated shape of typical wood-derived fibers in agitated suspensions can give rise to frequent inter-fiber collisions and the formation of fiber flocs. At a submicroscopic scale, surfaces of suspended materials can become joined by macromolecular bridges. Although such bridges tend to reduce paper’s uniformity, polyelectrolyte flocculants are used in most paper machine systems to achieve relatively high retention efficiencies of fine particles as paper is being formed. By adjusting the papermaking equipment, judiciously selecting points of addition of chemicals, and by managing chemical dosages, papermakers employ a variety of strategies to achieve favorable combinations of retention and uniformity. This review considers scholarly work that has been directed towards a greater understanding of the underlying mechanisms.