In lignin-first biorefining via reductive processes, lignocellulosic materials are deconstructed by the solvent extraction of lignin in the presence of a hydrogenation catalyst. This approach provides a route to the successful extraction and reductive passivation of lignin fragments to produce low molar mass lignin oils together with high-quality pulps. Herein, we present an investigation into the impact of process severity (i.e., cooking temperature) on the reductive processes taking place on the lignin fragments and uniformity of the product mixture. In addition to improving overall delignification yields (up to 87%) and producing low molar mass fragments, higher process temperatures led to the preferential cleavage of hydroxyl groups in monolignol sidechains via hydrodeoxygenation, yielding oils with lower oxygen content. By comparing products from both lignin-first biorefining and organosolv processes at various temperatures, we elucidate key performance differences and outline routes to increased chemical uniformity in lignin streams. Overall, this study outlines clearly the importance of process temperature in the deconstruction of lignocellulose by lignin-first biorefining when producing highly depolymerized lignin products. This study points out a trade-off in the effect of temperature upon delignification and increase in product mixture complexity, which needs to be carefully optimized for the scale-up of lignin-first technologies.

Abstract: Convergence among treatment, prevention, and developmental psychosocial intervention approaches has led to the recognition of the need for evaluation models and research designs that employ a full range of evaluation information to provide an empirical basis for enhancing the efficiency, efficacy, and effectiveness of prevention and psychosocial positive youth development interventions (PYD). This study reports an investigation of a PYD psychosocial program using an Outcome Mediation Cascade (OMC) evaluation model, which is an integrated model for evaluating the empirical intersection between intervention and developmental processes. The Changing Lives Program (CLP) is a community engaged PYD psychosocial intervention for multi-ethnic, multi-problem at risk youth in urban alternative high schools. Findings indicated that the hypothesized model fit the data, χ2(7) = 6.991, p = .43, RMSEA = .00, CFI = 1.00, WRMR = .459. Findings also provided preliminary evidence consistent with the hypothesis that, in addition to having effects on targeted positive outcomes, PYD interventions are likely to have progressive cascading effects on untargeted problem outcomes (in this case, behavioral outcomes) that operate through effects on positive outcomes.

Resumen: La convergencia entre enfoques de tratamiento, prevención e intervención psicosocial evolutiva ha dado lugar a que se reconozca que se necesitan modelos de evaluación y diseños de investigación que utilicen una gama completa de información sobre evaluación que siente la base empírica para mejorar la eficiencia, la eficacia y la efectividad de la prevención y de las intervenciones psicosociales en el desarrollo positivo de la juventud (DPJ). Este estudio trata de la investigación sobre un programa psicosocial sobre DPJ utilizando el Outcome Mediation Cascade (OMC), modelo integrado para evaluar la intersección empírica entre la intervención y los procesos de desarrollo. El Changing Lives Program (CLP) es una intervención psicosocial de DPJ en la que está implicada la comunidad para jóvenes multiétnicos en riesgo en colegios urbanos de secundaria alternativos. Los resultados indican que el modelo postulado se ajusta a los datos, χ2(7) = 6.991, p = .43, RMSEA = .00, CFI = 1.00, WRMR = .459. Igualmente, los resultados aportan pruebas preliminares consistentes con la hipótesis de que además de tener influencia en los resultados positivos planeados es probable que las intervenciones DPJ tengan efectos progresivos en cascada en los resultados no previstos de los problemas (en este caso, resultados en el comportamiento) que operan a través de sus efectos en los resultados positivos.

The contextualized understanding of concepts in Chemistry by students from other areas is a challenging task. In this experiment, the synthesis of biodiesel is done by base catalyzed transesterification of refined soy oil with methanol at room temperature and common glassware found in any chemistry laboratory. The proposal permits introducing several concepts, such as that of emulsion, viscosity and catalysis to illustrate an activity based on an actual problem. In this didactic approach, some common problems of biodiesel production, such as soap formation and phase separation, are introduced into the procedure in order to raise questions and motivate the students to participate in the experimental work and stimulate reflections about critical aspects of biodiesel production. This experiment was carried out in the first semester of 2006, in experimental general chemistry taken by physics and agricultural, civil and chemical engineering students of UNICAMP.