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Abstract Lignin is considered as a renewable and sustainable resource for producing value-added aromatic chemicals and functional carbon materials. Herein, we develop a one-step catalyst-free depolymerization strategy to convert lignin into aryl monomers and carbon nanospheres simultaneously. Importantly, microwave-assisted depolymerization (MAD) in conjunction with dichloromethane (CH2Cl2) vapors is developed. The total mass yield of guaiacols reached the highest amount of 225.1 mg/g at 600 °C, and the highest yields of phenols (49.0 mg/g) and aromatic hydrocarbons (155.1 mg/g) were obtained at 700 °C. Hydrogen radicals and hydrogen chloride (HCl) are in-situ formed from CH2Cl2, significantly decreasing the activation barrier and reforming pyrolysis vapors to promote the formation of aryl monomers. Interestingly, uniform carbon nanospheres with an average size of 140 nm were produced as co-products at 700 °C. The microwave “hot-spots”, allied with the continuous surface erosion and the decrease in surface energy of lignin-derived carbon precursors by CH2Cl2 vapor, can be considered the driving force for the ultimate formation of carbon nanospheres. The CH2Cl2/MAD system produces aryl monomers (26.8 wt% yield) and carbon nanospheres (36.6 wt% yield) at 700 °C. We provide a facile, intriguing and scalable approach to convert lignin to valuable aryl monomers and sustainable carbon materials that can be applied in the chemistry, energy and environmental fields.

Recent pressures to obtain energy from plant biomass have encouraged new metabolic engineering strategies that focus on accumulating lipids in vegetative tissues at the expense of lignin, cellulose and/or carbohydrates. There are at least three important factors that support this rationale. (i) Lipids are more reduced than carbohydrates and so they have more energy per unit of mass. (ii) Lipids are hydrophobic and thus take up less volume than hydrated carbohydrates on a mass basis for storage in tissues. (iii) Lipids are more easily extracted and converted into useable biofuels than cellulosic-derived fuels, which require extensive fractionation, degradation of lignocellulose and fermentation of plant tissues. However, while vegetative organs such as leaves are the majority of harvestable biomass and would be ideal for accumulation of lipids, they have evolved as "source" tissues that are highly specialized for carbohydrate synthesis and export and do not have a propensity to accumulate lipid. Metabolism in leaves is directed mostly toward the synthesis and export of sucrose, and engineering strategies have been devised to divert the flow of photosynthetic carbon from sucrose, starch, lignocellulose, etc. toward the accumulation of triacylglycerols in non-seed, vegetative tissues for bioenergy applications.

Pregaming, or drinking before going out, is a commonly practiced risky behavior. Drinking motives are well-established predictors of alcohol use and negative alcohol consequences. Given the influence of context on drinking practices, motives specific to pregaming may affect pregaming behaviors and outcomes above and beyond general drinking motives. Thus, we examined how pregaming motives are related to pregaming behaviors and negative alcohol consequences.Using data from two national cross-sectional online studies, the current study included undergraduates who pregamed at least once in the past month (n=10,200, Mage=19.9, women=61%, white=73.6%; 119 U.S. universities). Participants completed assessments of demographics, general drinking motives, pregaming motives, pregaming frequency/consumption, and negative alcohol consequences. Data were analyzed using hierarchical linear models accounting for nesting of participants within sites.When controlling for demographic factors and general drinking motives, interpersonal enhancement motives and intimate pursuit motives were positively associated with pregaming frequency, pregaming consumption, and negative alcohol consequences. Situational control motives were negatively associated with pregaming consumption and negative alcohol consequences. Barriers to consumption motives were negatively associated with pregaming frequency but positively associated with negative alcohol consequences.Students who pregame to make the night more fun or to meet potential dating partners appear to be at particular risk for negative alcohol consequences. Motives may be modifiable, particularly via cognitive/behavioral strategies. Findings suggest that specific motives may be appropriate intervention targets when trying to reduce pregaming behaviors and negative alcohol consequences.

Thirteenth National Passive Solar Conference Proceedings : Solar '88: 20 June 1988, Cambridge, MA, USA

Abstract As a type of solid waste, the used cigarette filters (UCF) were utilized to produce ester-rich bio-oil via a cleaner production process, namely, microwave-assisted pyrolysis (MAP). The pyrolysis efficiency was significantly enhanced owing to the high heating rate under MAP conditions with assistance of microwave absorber silicon carbide (SiC) in reactor and adding methanol into N2 carrier gas. Compared with the traditional tubular muffle furnace heating method yielding 0% of bio-oil, the MAP heating method obtained 29.17% of bio-oil from UCF. The bio-oil yield from UCF increased from 29.17% to 46.71% due to the introduction of methanol. Results of the gas chromatography/mass spectrometry showed that esters were the main components in the bio-oils (over 40%), especially of methyl acetate (over 12%). The aromatic compounds of phenols and polycyclic aromatic hydrocarbons (PAHs) were also produced from the MAP of UCF. The bio-char from MAP of UCF exhibited the mesoporous property (e.g., over 500 m2/g of specific surface area). It is expected to produce over 350000 metric tons ester-rich bio-oil if the proposed technology can be scaled up globally. It will be a preeminent contribution for the conversion of UCF to the cleaner production and our environments.

Abstract: Three pathways for resource acquisition exist in the emergent aquatic plant, Lythrum salicaria (L.); a subterranean root system, a free‐floating adventitious root system, and arbuscular mycorrhiza (AM) fungal hyphae colonizing subterranean roots. This study examined the relationship(s) among these pathways and their contribution to plant performance. If the free‐floating adventitious root system and/or AM fungi contribute to plant growth in wetland habitats, we predicted that their absence would result in a significant reduction in plant performance. Furthermore, if a reduction in resource uptake, effected by an absence of free‐floating adventitious roots and/or AM fungi, is compensated for by increased allocation to remaining pathway(s) for resource uptake, we predicted altered patterns of resource allocation among shoots and the remaining pathway(s) for resource uptake. Contrary to our predications, plants experiencing adventitious root removal and/or grown in the absence of AM fungi generally had greater biomass and total shoot height than controls. Similarly, while levels of AM colonization and subterranean root biomass displayed a treatment effect, the observed responses did not correspond with our predictions. This was also true for shoot: subterranean root dry weight ratios. Our results indicate that there is interaction among the 3 pathways for resource acquisition in L. salicaria and an effect on plant performance. The adaptive significance of these characteristics is unclear, highlighting the potential difficulties in extrapolating from terrestrial to aquatic plant species and among aquatic plant species with potentially different life history strategies.

Abstract Airflow and heat transfer simulation was conducted for a DSF system equipped with a venetian blind, using computational fluid dynamics (CFD) with RNG turbulence model, for a three-level combination of slat tilt angle and blind position. The CFD prediction was validated using experimental data collected for a mechanically ventilated DSF equipped with venetian blinds. The predicted trends in glass and blind surface temperatures of the CFD model are compared well with the experimental measurements. The present study indicates that the presence of venetian blinds influences the surface heat transfer coefficients (SHTCs), the temperature and the air distribution in the DSF system. For the cases considered, the changes in the position of the blinds (outer, middle, and inner) have more effect on the distribution of temperature, velocity, and SHTCs compared to the changes in the slat angles ( θ = 0°, 45°, 90°).

Western spruce budworm (Choristoneura freemani Razowski, 2008) is the most widely distributed insect herbivore in western North American coniferous forests. By partially or completely defoliating tree crowns, budworms influence fluxes of water, nutrients, and organic carbon from forest canopies to soils and, in turn, soil chemistry. To quantify these effects, throughfall water, inorganic nitrogen (N), phosphorus (P), and dissolved organic carbon (DOC) concentrations, as well as fluxes and soil N and P concentrations, were measured in coniferous forest sites with high and background levels of budworm herbivory. Throughfall N and P concentrations and fluxes increased at sites with high budworm levels during and (or) immediately after larval-stage budworm feeding, indicating reduced uptake and (or) greater leaching from canopies as a result of budworm activity. Annual throughfall N fluxes (<67–71 g N·ha−1·year−1) and soil N concentrations were low regardless of herbivory level. In contrast, throughfall P was considerably greater at sites with high herbivory levels (2174 g P·ha−1·year−1) compared with those with background levels (1357 g P·ha−1·year−1), and this was reflected in nearly threefold higher soil P concentrations at sites with high budworm levels. Our findings suggest that by altering throughfall chemistry and soil N:P, budworms could influence elemental export from watersheds.