We evaluated lignin profiles and pulping performances of 2-year-old transgenic poplar (Populus tremula x Populus alba) lines severely altered in the expression of caffeic acid/5-hydroxyferulic acid O-methyltransferase (COMT) or cinnamyl alcohol dehydrogenase (CAD). Transgenic poplars with CAD or COMT antisense constructs showed growth similar to control trees. CAD down-regulated poplars display...

Paper furnishes often contain a mixture of a weak pulp with relatively short fibers and a strong pulp with relatively long fibers. Whereas increased proportion of the long-fiber pulp can be expected to impair formation, it has been unclear to what extent a change in formation through the pulp ratio affects the strength efficiency. (Strength efficiency is a measure of how well the strength poten...

Abstract The use of paper dry strength additives is one the methods for producing packaging boards with a lower grammage while maintaining mechanical properties. In present work, papers were formed using dissolving grade kraft fibres, fibres and carboxymethylated cellulose (CMC) modified (C-kraft fibres), either cationic starch (CS), anionic polyacrylamide (APAM) or polyelectrolyte complexes (P...

Worldwide, wild fish living in rivers receiving municipal and industrial discharges may experience endocrine disruption as a result of exposure to anthropogenic pollutants. The purpose of this study was to evaluate the hormonal status of wild fish in a U.S. river receiving unbleached kraft and recycled pulp mill effluent (Pearl River at Bogalusa, LA). We evaluated two alternative hypotheses: th...

Demethylation of softwood kraft lignin from woody biomass to improve the hydroxyl number in modified demethylated lignin and to produce lignin-based polyols was investigated using several biophysical techniques. Lignin is a tremendously under-developed natural polymer co-generated through papermaking and biomass fractionation. Molecular weights of lignins were analyzed by high-performance size-...

This work deals with lignin antioxidant properties in polypropylene. We extracted and characterised 15 lignin samples from various botanical origins (wheat straw and wheat bran) using different processes of extraction and using industrial Kraft lignins fractions (Westaco). These lignins were incorporated in polypropylene (1% weight). We underline the effect of lignin solubility in PP on stabili...

This work aims to develop a new ionic liquid, used as an aprotic green ä solvent, to dissolve kraft lignin from black liquor. The kraft lignin was extracted through precipitation with carbon dioxide at atmospheric pressure. 1,8-Diazabicyclo[5.4.0]undec-7-ene-based ionic liquids were obtained by quaternization of the nitrogen atom with a hydrogen atom or an alkyl chain. The yields of the synthes...

Suggested Citation: Kraft, M.A. (2015). Teacher layoffs, teacher quality and student achievement: Evidence from a discretionary layoff policy. West for their helpful comments on earlier drafts of this manuscript.

Xylanase activity was isolated from crude extracts of Trichoderma harzianum strains C and 4 grown at 28 degree C in a solid medium containing wheat bran as the carbon source. Enzyme activity was demonstrable in the permeate after ultrafiltration of the crude extracts using an Amicon system. The hydrolysis patterns of different xylans and paper pulps by xylanase activity ranged from xylose, xylo...