Publications by authors named "C Hubbell"

Systematic survey is a crucial component of the archaeological field endeavor. In low visibility areas, systematic subsurface testing is required, most often in the form of shovel test pits or "STPs". Decisions about the interval between STPs, and the size of such units, impact significantly both the effectiveness of survey for site location and the efficiency of such prospection efforts, and yet "cookie-cutter" survey strategies are often employed without a thorough examination of their costs and benefits.

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Two established delignification methods employing sodium chlorite-acetic acid (SC/AA) and peracetic acid (PAA) are often used, and are reportedly highly selective. However, these reports are mostly for highly recalcitrant and unpretreated softwoods and hardwoods species, and information for less recalcitrant lignocellulosic feedstocks and pretreated biomass is scarce. Furthermore, the effects on cellulose structure are not documented.

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In order to obtain accurate information about the ultrastructure of cellulose from native biomass by C cross polarization magic angle spinning (CP/MAS) NMR spectroscopy the cellulose component must be isolated due to overlapping resonances from both lignin and hemicellulose. Typically, cellulose isolation has been achieved via holocellulose pulping to remove lignin followed by an acid hydrolysis procedure to remove the hemicellulose components. Using C CP/MAS NMR and non-linear line-fitting of the cellulose C₄ region, it was observed that the standard acid hydrolysis procedure caused an apparent increase in crystallinity of ~10% or less on the cellulose isolated from Populus holocellulose.

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