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Integrating teaching and research can benefit both instructors and students by providing an enriching, stimulating experience that combines the instructors' interests with topics that are relevant and motivating to students. In keeping with National Science Foundation review criteria, the integrated course captures both intellectual merit, that is the technological and scientific innovation of the research, and broader impacts, that is the potential benefits to society. This article describes a bioenergy course that included several well-known learning activities, including lab tours, lab activities, guest lectures, and group discussions, to integrate intellectual merit and broader impacts into undergraduate education. Each of these techniques fills a specific role in delivering content that helps break down barriers between research and education. Overall student response has been positive, with course evaluations providing qualitative evidence of greater student motivation and deeper learning.

As part of the third NASA Aircraft Particle Emissions Experiment (APEX-3, November 2005), whole air samples were collected to determine the emission rates of volatile organic compounds (VOCs) from aircraft equipped with three different gas-turbine engines (an Allison Engine 3007-A1E, a Pratt-Whitney 4158, and a Rolls-Royce RB211-535E4B). Samples were collected 1 m behind the engine exhaust plane of the engines while they were operated at powers ranging from idle up to 30% of maximum rated thrust.Exhaust emission indices (mass emitted per kilogram of fuel used) for CO and non-methane hydrocarbons (NMHCs) were calculated based on enhancements over background relative to CO 2. Emissions of all NMHCs were greatest at low power with values decreasing by an order of magnitude with increasing power. Previous studies have shown that scaling idle hydrocarbon emissions to formaldehyde or ethene (which are typically emitted at a ratio of 1-to-1 at idle) reduces variability amongst engine types. NMHC emissions were found to scale at low power, with alkenes contributing over 50% of measured NMHCs. However, as the power increases hydrocarbon emissions no longer scale to ethene, as the aromatics become the dominant species emitted. This may be due in part to a shift in combustion processes from thermal cracking (producing predominantly alkenes) to production of new molecules (producing proportionally more aromatics) as power increases. The formation of these aromatics is an intermediate step in the production of soot, which also increases with increasing power. The increase in aromatics relative to alkenes additionally results in a decrease in the hydroxyl radical reactivity and ozone formation potential of aircraft exhaust.Samples collected 30 m downwind of the engine were also analyzed for NMHCs and carbonyl compounds (acetone, 2-butanone and C 1-C 9 aldehydes). Formaldehyde was the predominant carbonyl emitted; however, the ratio of ethene-to-formaldehyde varied between the aircraft, possibly due to the sampling of transient emissions such as engine start-up and power changes. A large portion of the measured emissions (27-42% by mass) in the plume samples was made up of hazardous air pollutants (HAPs) with oxygenated compounds being most significant. © 2012.

We report evidence that carbon impregnated conductive silicone tubing used in aerosol sampling systems can introduce two types of experimental artifacts: 1) silicon tubing dynamically absorbs carbon dioxide gas, requiring greater than 5 minutes to reach equilibrium and 2) silicone tubing emits organic contaminants containing siloxane that adsorb onto particles traveling through it and onto downstream quartz fiber filters. The consequence can be substantial for engine exhaust measurements as both artifacts directly impact calculations of particulate mass-based emission indices. The emission of contaminants from the silicone tubing can result in overestimation of organic particle mass concentrations based on real-time aerosol mass spectrometry and the off-line thermal analysis of quartz filters. The adsorption of siloxane contaminants can affect the surface properties of aerosol particles; we observed a marked reduction in the water-affinity of soot particles passed through conductive silicone tubing. These combined observations suggest that the silicone tubing artifacts may have wide consequence for the aerosol community and should, therefore, be used with caution. Gentle heating, physical and chemical properties of the particle carriers, exposure to solvents, and tubing age may influence siloxane uptake. The amount of contamination is expected to increase as the tubing surface area increases and as the particle surface area increases. The effect is observed at ambient temperature and enhanced by mild heating (

During the process of subcritical water hydrolysis of lignocellulosic compounds, such as brewers' spent grains, some toxic compounds can be formed due to the breakdown of the cellulose structure. These compounds are known as furanic aldehydes, and they are inhibitors of microorganisms that are used in different processes, such as fermentation and anaerobic digestion, among others. The detoxification and conditioning of these hydrolysates are required before their use in other processes that require low concentrations of toxins. One of the mechanisms that can be used to diminish those compounds is the adsorption process. For this reason, this study evaluated at‐line and in‐line purification strategies using different adsorbents in fixed‐bed columns to remove furanic aldehydes from a model feed simulating hydrolysate from subcritical water hydrolysis. The model feed consisted of simple sugars and furanic aldehydes at appropriate concentrations. The selected adsorbents were silica‐C18, hydrocarbons, and activated carbon. The results indicate that, among the adsorbents that were studied, activated carbon was the most efficient for the removal of both 5‐hydroxymethylfurfural and furfural. The activated carbon removed >99% of furanic aldehydes in the experiments conducted in the at‐line system. Sequential subcritical water hydrolysis followed by either at‐line or in‐line purification is promising for integrated inexpensive and efficient hydrolysate purification. [ABSTRACT FROM AUTHOR]

Low- and middle-income countries have tremendous potential for renewable energy production, including production of renewable carbon from locally prolific crops. In this work, bamboo endemic to West Africa (Bambusa vulgaris) was studied as a feedstock for the production of renewable sugars as the gateway to the local production of biofuels and bio-based chemical products. The effectiveness of delignification and amorphization pretreatments was evaluated, with the observation that quantitative (97 ± 4%) sugar yields could be obtained with a rapid initial hydrolysis rate (82 ± 4 mg g−1 h−1) but only when amorphization was performed following delignification. Experimental measurements and further characterization using 13C solid state nuclear magnetic resonance (NMR) helped establish the importance of amorphization and delignification and explained why the order of these treatments determined their effectiveness. The economics of the bamboo-based process were compared with those projected for corn stover, selected as a well-studied benchmark crop. Because of the higher bamboo growth rate compared with corn stover and the effectiveness of the pretreatment, the projected net present value (NPV) of the bamboo biorefinery was positive ($190 MM, U.S.), whereas the corn biorefinery projected to negative NPV (−$430 MM, U.S.). A socially sustainable framework for deployment of a bamboo biorefinery in a low- or middle-income economy was then proposed, guided by the principle of local ownership and stakeholder buy-in. The findings presented here motivate further investment in development of bamboo cultivation and conversion to sugars as a rapid route to decarbonization of low- and middle-income economies. [ABSTRACT FROM AUTHOR]