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Abstract Like cities, many large national parks in the United States often include “urban” visitor and residential areas that mostly demand (rather than produce) energy and key urban materials. The U.S. National Park Service has committed to quantifying and reducing scopes 1 and 2 emissions by 35% and scope 3 emissions by 10% by 2020 for all parks. Current inventories however do not provide the specificity or granularity to evaluate solutions that address fundamental inefficiencies in these inventories. By quantifying and comparing the importance of different inventory sectors as well as upstream and downstream emissions in Yosemite National Park (YNP), this carbon footprint provides a case study and potential template for quantifying future emissions reductions, and for evaluating tradeoffs between them. Results indicate that visitor-related emissions comprise the largest fraction of the Yosemite carbon footprint, and that increases in annual visitation (3.43–3.90 million) coincide with and likely drive interannual increases in the magnitude of Yosemite′s extended inventory (126,000–130,000 t CO2e). Given this, it is recommended that “per visitor” efficiency be used as a metric to track progress. In this respect, YNP has annually decreased kilograms of GHG emissions per visitor from 36.58 (2008) to 32.90 (2011). We discuss opportunities for reducing this measure further.

Isolated cobalt atoms with CoN4configuration are decorated into a multichannel carbon matrix for efficient electrocatalytic oxygen reduction reaction.

Bacterial biofilters usually exhibit a high microbial diversity and robustness, while fungal biofilters have been claimed to better withstand low moisture contents and pH values, and to be more efficient coping with hydrophobic volatile organic compounds (VOCs). However, there are only few systematic evaluations of both biofiltration technologies. The present study compared fungal and bacterial biofiltration for the treatment of a VOC mixture (propanal, methyl isobutyl ketone-MIBK, toluene and hexanol) under the same operating conditions. Overall, fungal biofiltration supported lower elimination capacities than its bacterial counterpart (27.7 ± 8.9 vs 40.2 ± 5.4 gCm(-3) reactor h(-1)), which exhibited a final pressure drop 60% higher than that of the bacterial biofilter due to mycelial growth. The VOC mineralization ratio was also higher in the bacterial bed (≈ 63% vs ≈ 43%). However, the substrate biodegradation preference order was similar for both biofilters (propanal>hexanol>MIBK>toluene) with propanal partially inhibiting the consumption of the rest of the VOCs. Both systems supported an excellent robustness versus 24h VOC starvation episodes. The implementation of a fungal/bacterial coupled system did not significantly improve the VOC removal performance compared to the individual biofilter performances.

In membrane bioreactors applied to wastewater treatment, fouling is typically a complex function of sludge characteristics. A pilot-scale tertiary submerged membrane bioreactor (tMBR) was continuously operated for over 200 days to assess the effect of biomass physiological state and environmental stress on process performance. Sludge characteristics were evaluated in terms of suspended solid concentration (MLSS and MLVSS), apparent viscosity, bioflocculation state, filterability, bioactivity, biopolymeric clusters (BPCs) and soluble microbial products. During the initial period of the tMBR start-up, when MLSS was below 3000 mg/L, the biomass was found to be very sensitive to environmental stress by sudden oxygen increase or organic shock loading, resulting in temporary biomass deflocculation and BPC release, and consequently, severe induced membrane fouling. However, at higher MLSS values, low stable biomass growth (0.04 ± 0.002 kg MLVSS/kg COD) was measured, regardless of organic overloading shocks or feeding failures. This period was also characterised by low bioactivity, BPC content and membrane fouling. Statistical analysis showed that BPCs have an important role when compared with other sludge properties as indicators of its fouling potential.

A multichip module component manufacturing process combining multilayer polyimide and multilayer low-temperature cofired ceramic structures, using the latter as the encapsulation support, is described. A first characterization of the results is also reported. The procedures described make it possible to integrate resistances in thin/thick-film technology. >

AbstractThis paper presents a method for estimating recombination parameters in the volume and surface of solar cell precursors throughout the manufacturing process, taking into account several effects that are generally neglected. The technique is based on the comprehensive reconstruction of the effective lifetime assuming a set of fundamental parameters and its comparison to the experimental data obtained from the photoconductance measured under uniform generation in quasi‐steady state conditions. The analysis starts from the semianalytical solution of the minority carrier profiles in the structures under test. This analysis overcomes the usual flat profile approximation and presents important advantages. It allows the asymmetry presented by the solar cell precursors to be taken into account and deals with a wide range of surface conditions: emitters, bare silicon or dielectric passivations. The model also accounts for the effect of the electric field in the volume, and implements several phenomena that are sometimes neglected but are relevant when measuring industrial solar cells precursors: the injection dependence of mobilities and recombination lifetimes, the presence of non‐recombinant traps and the Depletion Region Modulation effect. The estimation technique requires uniform generation, which greatly facilitates the calculation of the carrier profiles and allows for a simple method for the auto calibration of the light absorption. Copyright © 2006 John Wiley & Sons, Ltd.

Dietary change presents an opportunity to meet the dual challenges of non-communicable diseases and the effects of climate change in China. Based on a food survey and reviewed data sets, we linked nutrient composition and carbon footprint data by aggregating 1950 types of foods into 28 groups. Nine dietary scenarios for both men and women were modeled based on the current diet and latest National Program for Food and Nutrition. Linear uncertainty optimization was used to produce diets meeting the Chinese Dietary Reference Intakes for adults aged 18-50years while minimizing carbon footprints. The theoretical optimal diet reduced daily footprints by 46%, but this diet was unrealistic due to limited food diversity. Constrained by acceptability, the optimal diet reduced the daily carbon footprints by 7-28%, from 3495 to 2517-3252g CO2e, for men and by 5-26%, from 3075 to 2280-2917g CO2e, for women. Dietary changes for adults are capable of benefiting China in terms of the considerable footprint reduction of 53-222Mt.CO2eyear-1, when magnified based on the Chinese population, which is the largest worldwide. Seven of eight scenarios showed that reductions in meat consumption resulted in greater reductions in greenhouse gas emissions. However, dramatic reductions in meat consumption may produce smaller reductions in emissions, as the consumption of other ingredients increases to compensate for the nutrients in meat. A trade-off between poultry and other meats (beef, pork, and lamb) is usually observed, and rice, which is a popular food in China, was the largest contributor to carbon footprint reductions. Our findings suggest that changing diets for climate change mitigation and human health is possible in China, though the per capital mitigation potential is slight lower than that in developed economies of France, Spain, Sweden, and New Zealand.

With the aim of increasing knowledge of community structure, dynamics and production of ectomycorrhizal fungi, edible sporocarp yields were monitored between 1995 and 2004 in a Pinus sylvestris stand in the northeast zone of the Iberian Peninsula. A random sampling design was performed by stand age class according to the forest management plan: 0-15, 16-30, 31-50, 51-70 and over 71-years-old. Eighteen 150 m plots were established and sampled weekly every year from September to December. One hundred and nineteen taxa belonging to 51 genera were collected, 40 of which were edible and represented 74% of the total biomass. Boletus edulis, Lactarius deliciosus, Cantharellus cibarius and Tricholoma portentosum sporocarps, which are considered to be of high commercial value, represented 34% of the total production. B. edulis and L. deliciosus were the most remarkable and abundant species, and both were collected in more than 60% of the samplings. B. edulis fructified every year of the experiment; its mean production was 40 kg/ha and year and its maximum productivity was more than 94 kg/ha in 1998. The age class with the largest production of this taxa was the fourth (51-70 years), with 70 kg/ha. L. deliciosus only failed to fructify one autumn (2000); its mean production was almost 10 kg/ha and its maximum productivity close to 30 kg/ha in 1997. The maximum productivity of this species was found in the second (16-30 years) and fifth (71-90 years) stand age classes, with 18 and 16 kg/ha, respectively. Advances in this field can certainly offer new insights into factors affecting sporocarp production.

Abstract Anaerobic treatment of palm oil mill effluent (POME) was studied using a 16-litre laboratory scale up-flow anaerobic sludge blanket reactor (UASB) run over a range of influent concentrations from 5.1 to 42.5 g Chemical Oxygen Demand (COD) per litre at a constant hydraulic retention time of four days. Methane production, volatile fatty acid conversion, net sludge growth and Chemical Oxygen Demand reduction were monitored. Over 96% Chemical Oxygen Demand was removed at loadings up to 10.6 g COD l −1 day −1 . At the highest influent concentration reactor instability was observed. Up to this point the results indicated that the UASB could treat POME more effectively than other systems reviewed.