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Flexible butyl interconnection segments are synthetically incorporated into an electronically conductive poly(pyrene methacrylate) homopolymer and its copolymer. The insertion of butyl segment makes the pyrene polymer more flexible, and can better accommodate deformation. This new class of flexible and conductive polymers can be used as a polymer binder and adhesive to facilitate the electrochemical performance of a silicon/graphene composite anode material for lithium ion battery application. They act like a “spring” to maintain the electrode mechanical and electrical integrity. High mass loading and high areal capacity, which are critical design requirements of high energy batteries, have been achieved in the electrodes composed of the novel binders and silicon/graphene composite material. A remarkable area capacity of over 5 mAh/cm2 and volumetric capacity of over 1700 Ah/L have been reached at a high current rate of 333 mA/g.

The rapid development of advanced metering infrastructure provides a new data source—building electrical load profiles with high temporal resolution. Electric load profile characterization can generate useful information to enhance building energy modeling and provide metrics to represent patterns and variability of load profiles. Such characterizations can be used to identify changes to building electricity demand due to operations or faulty equipment and controls. In this study, we proposed a two-path approach to analyze high temporal resolution building electrical load profiles: (1) time-domain analysis and (2) frequency-domain analysis. The commonly adopted time-domain analysis can extract and quantify the distribution of key parameters characterizing load shape such as peak-base load ratio and morning rise time, while a frequency-domain analysis can identify major periodic fluctuations and quantify load variability. We implemented and evaluated both paths using whole-year 15-minute interval smart meter data of 188 commercial office building in Northern California. The results from these two paths are consistent with each other and complementary to represent full dynamics of load profiles. The time- and frequency-domain analyses can be used to enhance building energy modeling by: (1) providing more realistic assumptions about building operation schedules, and (2) validating the simulated electric load profiles using the developed variability metrics against the real building load data.

Previous studies reveal that the primary distribution of the current density is sharply enhanced at the edge of a disk electrode submerged into a semi-infinite space of conductive solution. The current enhancement will cause the double layer capacitance at the periphery of the electrode to be charged much faster compared to the center, and can also lead to severe corrosion at the edge. While several studies focused on the geometric design of the electrode to reduce this enhancement, we explore the feasibility of achieving similar effect by shaping the edges of the current input. The simulation uses finite element analysis software to solve the system of partial differential equations and results show that the edge enhancement could be greatly reduced without significantly changing the input efficacy of current and/or charge.

Background:  We previously found that activation of the glial cell line‐derived neurotrophic factor (GDNF) pathway in the ventral tegmental area (VTA) reduces ethanol‐drinking behaviors. In this study, we set out to assess the contribution of endogenous GDNF or its receptor GFRα1 to the regulation of ethanol‐related behaviors.Methods:  GDNF and GFRα1 heterozygote mice (HET) and their wild‐type littermate controls (WT) were used for the studies. Ethanol‐induced hyperlocomotion, sensitization, and conditioned place preference (CPP), as well as ethanol consumption before and after a period of abstinence were evaluated. Blood ethanol concentration (BEC) was also measured.Results:  We observed no differences between the GDNF HET and WT mice in the level of locomotor activity or in sensitization to ethanol‐induced hyperlocomotion after systemic injection of a nonhypnotic dose of ethanol and in BEC. However, GDNF and GFRα1 mice exhibited increased place preference to ethanol as compared with their WT littermates. The levels of voluntary ethanol or quinine consumption were similar in the GDNF HET and WT mice, however, a small but significant increase in saccharin intake was observed in the GDNF HET mice. No changes were detected in voluntary ethanol, saccharin or quinine consumption of GFRα1 HET mice as compared with their WT littermates. Interestingly, however, both the GDNF and GFRα1 HET mice consumed much larger quantities of ethanol after a period of abstinence from ethanol as compared with their WT littermates. Furthermore, the increase in ethanol consumption after abstinence was found to be specific for ethanol as similar levels of saccharin intake were measured in the GDNF and GFRα1 HET and WT mice after abstinence.Conclusions:  Our results suggest that endogenous GDNF negatively regulates the rewarding effect of ethanol and ethanol‐drinking behaviors after a period of abstinence.

Atmospheric methane (CH4) is a potent greenhouse gas, and its mole fraction has more than doubled since the preindustrial era. Fossil fuel extraction and use are among the largest anthropogenic sources of CH4 emissions, but the precise magnitude of these contributions is a subject of debate. Carbon-14 in CH4 (14CH4) can be used to distinguish between fossil (14C-free) CH4 emissions and contemporaneous biogenic sources; however, poorly constrained direct 14CH4 emissions from nuclear reactors have complicated this approach since the middle of the 20th century. Moreover, the partitioning of total fossil CH4 emissions (presently 172 to 195 teragrams CH4 per year) between anthropogenic and natural geological sources (such as seeps and mud volcanoes) is under debate; emission inventories suggest that the latter account for about 40 to 60 teragrams CH4 per year. Geological emissions were less than 15.4 teragrams CH4 per year at the end of the Pleistocene, about 11,600 years ago, but that period is an imperfect analogue for present-day emissions owing to the large terrestrial ice sheet cover, lower sea level and extensive permafrost. Here we use preindustrial-era ice core 14CH4 measurements to show that natural geological CH4 emissions to the atmosphere were about 1.6 teragrams CH4 per year, with a maximum of 5.4 teragrams CH4 per year (95 per cent confidence limit)—an order of magnitude lower than the currently used estimates. This result indicates that anthropogenic fossil CH4 emissions are underestimated by about 38 to 58 teragrams CH4 per year, or about 25 to 40 per cent of recent estimates. Our record highlights the human impact on the atmosphere and climate, provides a firm target for inventories of the global CH4 budget, and will help to inform strategies for targeted emission reductions.

Abstract The albedo of a roof determines the fraction of incoming sunlight that is reflected, which affects heat transfer into the building and exchange of energy between the built environment and the atmosphere. While the albedo of individual roofs can be easily measured, roof albedo at the city scale is unknown. In this paper we characterize the albedos of roofs in seven cities in California: Los Angeles, Long Beach, Bakersfield, San Francisco, San Jose, Sacramento, and San Diego. The fraction of urban area covered by roofs ranged by city from 10% to 25%. City-wide average roof albedo ranged from 0.17 ± 0.08 to 0.20 ± 0.11 (mean ± standard deviation) for five of the cities; values were higher in Sacramento (0.24 ± 0.11) and San Diego (0.29 ± 0.15). Buildings with small roofs were found to constitute a large fraction of city roof area and to have low mean albedos. This suggests that efforts to increase urban albedo through the use of reflective roofs should include small roofs, which are presumably mostly residential. Roof albedos derived for Bakersfield were used in a regional climate model (Weather Research and Forecasting Model) to estimate temperature changes attainable by converting the current stock of roofs to “cool” high albedo roofs. It was found that seasonal mean afternoon (15:00 LST) temperatures could be reduced by up to 0.2 °C during both the summer and winter. Changes in precipitation were not significant at the 95% confidence level.

Integrated assessment models show that, without new climate policies, abundant supplies of natural gas will have little impact on greenhouse-gas emissions and climate change. See Letter p.482 The development of hydraulic fracturing technologies has led to rapid growth in the use natural gas as an energy source. Some evidence has suggested that this growing adoption of natural gas might lead to a reduced greenhouse gas burden and consequent mitigation of climate change. This collaboration between five energy–climate modelling teams show that instead — under a scenario of abundant natural gas availability — increased consumption will have little or no impact on climate change. The authors suggest that expanded natural gas production and use is neither a substitute for a climate policy in the decades ahead nor a major new complication to the anthropogenic emissions problem.

Owing to its amorphous structure, a chalcogenide glass exhibits a thermal conductivity k approaching the theoretical minimum of its composition, called the Einstein’s limit. In this work, this limit is beaten in an amorphous solid consisting of glassy particles joined by nanosized contacts. When amorphous particles are sintered below the glass transition temperature under a high pressure, these particles can be mechanically bonded with a minimized interfacial thermal conductance. This reduces the effective k below the Einstein’s limit while providing superior mechanical strength under a high pressure for thermal insulation applications under harsh environments. The lowest room temperature k for the solid counterpart can be as low as 0.10 W/m·K, which is significantly lower than k≈0.2 W/m·K for the bulk glass.