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This paper presents experimental results of the impact of CO(2) co-feed on a gasification/pyrolysis process for various feedstocks (biomass, coal, and municipal solid waste (MSW)). Various feedstocks were thermo-gravimetrically characterized under various atmospheric conditions and heating rates. A substantial amount of char burn out was identified in the presence of CO(2) via a series of thermo-gravimetric analysis tests, which enabled high conversion of final mass (approximately 99%) to be achieved. The impact of CO(2) co-feed on the volatilization regime during the pyrolysis/gasification process was not apparent at a heating rate of 10-40 degrees C min(-1). However, the impact of CO(2) on the volatilization regime at a fast heating rate (950 degrees C min(-1)) was substantial. For example, significant enhancement in the generation of CO, by a factor of approximately 2, was observed in the presence of CO(2). The generation of major chemical species, such as CH(4) and C(2)H(4), were enhanced, but this was not as apparent as in the case with CO. In addition, introducing CO(2) to the pyrolysis/gasification process enabled the amount of condensable liquid hydrocarbons, such as tar (approximately 30-40%) to be significantly reduced in the presence of CO(2), in that injecting CO(2) into the pyrolysis/gasification process expedites cracking the volatilized chemical species. Experimental work confirmed that biomass and MSW could be feasible and desirable feedstocks for the pyrolysis/gasification process as these feedstocks can be easily treated compared to coal. To extend this understanding to a more practical level, various feedstocks were tested in a tubular reactor and drop tube reactor under various experimental conditions.

Abstract Bed expansion of fine powders was investigated in two high aspect ratio fluid beds, an expanded top bed and a circulating system. The range of gas velocities (0.07 – 8 m/s) spanned the bubbling/slugging, turbulent, fast, and dense conveying fluidization regimes. The two-phase theory was shown generally not to apply in the slugging and the higher velocity fluidization regimes. A modified Richardson-Zaki approach, using an ‘effective’ cluster terminal velocity, was shown to adequately describe bed expansion. Changes in slope of the expansion curve were associated with regime changes, and can prove useful for the analysis of large diameter fluid beds. The effect of particle size distribution was shown to be considerable.

Abstract A mathematical model of galvanostatic pulse and pulsed reverse electroplating of gold on a rotating disk electrode is presented. Using experimental polarization curves, dc current efficiencies, and literature-reported diffusion coefficients, model parameters are estimated. An accurate prediction of current efficiency by the on–off pulse-plating model was confirmed by experimental measurement. The current efficiency of pulse-reverse plating at relatively low waveform frequency is also successfully predicted, with less agreement at higher frequencies, presumably due to the simplified approach that the model employs to treat the complex set of reactions that occur during the anodic portion of the wave. When the reduction of adsorbed gold species produced during the oxidation portion of the pulse is included, improved agreement between experiment and theory is obtained.

Abstract As the size of buildings and demands on large centralized heating and cooling systems increases concurrent with rapid worldwide urbanization, the energy impact of hydronic distribution systems will become increasingly important in reducing greenhouse gas emissions. Further, in the U.S., the growth in multi-family buildings and the share of residential units in large multifamily buildings is far outpacing single-family construction. This paper describes a study of the pumping energy requirements of an urban 23-story mixed-use, primarily multifamily residential building before and after a suite of energy conservation measures. The retrofit focused on waterside technologies: Variable frequency drives (VFDs), constant and variable speed pumps, and pressure-independent control valves. In the original building, the central pumping equipment was found to be responsible for 55% of total annual owner-metered electricity usage and 29% of all annual owner-paid utility bills. Using extensive in-situ monitoring and analytical models developed for this effort, the full retrofit was computed to achieve a 41% reduction in annual central pumping electricity, representing an annual savings of 12% of all owner-paid energy bills. The most significant energy impact is attributable to the VFDs, and it can be inferred that additional savings could be achieved by installing VFDs on constant speed pumps.

Cobalt hexacyanoferrate (CoHCF) materials were used for TRECs; when complexed with HCNTs they show higher heat-to-electricity conversion efficiency.

Abstract Two types of waste derived chars were prepared by pyrolyzing at 600 °C biomass derived fuel (BDF) produced from rice straw and refuse derived fuel (RDF) composed of municipal solid waste and sewage sludge. Thermogravimetric analysis and differential scanning calorimetry (TGA-DSC) were used to investigate the non-isothermal combustion and gasification of the two chars. Kinetic study and reaction heat analysis were carried out and the results were compared. The chemical composition, internal structure, surface condition and carbon structure were also characterized to help understand the basic properties of waste derived chars and its relationship with the reactivity. The results showed that the BDF char samples were more porous and active than the RDF char samples. The total surface area of the BDF char samples was 209.7 m 2 /g and the percent of micropore was over 90%. But the surface area and percent of micropore for the RDF char samples were significantly lower. The relative content of graphitic carbon was 54.4% for the RDF char and 72.5% for the BDF char samples, indicating a more ordered carbon structure of the BDF char. The activation energies under combustion and gasification conditions were 50.1 kJ mol −1 and 137.9 kJ mol −1 for the RDF char, and 36.6 kJ mol −1 and 119.5 kJ mol −1 for the BDF char, respectively, as calculated by Ozawa–Flynn–Wall method. The ash of the BDF char samples showed improved catalytic activity compared to the RDF char samples. However, the catalytic activity was weaker for the gasification process due to the evaporation of AAEM (alkali and alkaline earth metals) species at high temperatures, especially potassium.

The endocochlear potential in a guinea pig's ear is captured and used to run a low-power radio.

In rat liver microsomes, all-trans-[11,12-3H]retinoic acid was found to be metabolized to polar products in the presence of NADPH. One of the metabolites was coeluted with 4-hydroxyretinoic acid on reverse-phase high-pressure liquid chromatography (HPLC). This reaction required oxygen and was inhibited by carbon monoxide as well as aminopyrine, aniline, and ethanol, suggesting the involvement of cytochrome P-450. Isolated rat hepatocytes also metabolized all-trans[3H]retinoic acid to polar compounds, with an elution pattern on HPLC similar to that in microsomal preparations. Microsomal activity was compared in rats pair-fed with diets containing either ethanol or isocaloric carbohydrate for 4–6 weeks. Ethanol-fed rats showed enhanced microsomal retinoic acid metabolism (50%, P < 0.01) accompanied by increased microsomal cytochrome P-450 content (34%, P < 0.005). On the other hand, microsomal β-glucuronidation of retinoic acid in the presence of uridine diphosphoglucuronic acid (UDPGA) was not affected by chronic ethanol feeding. The increased hepatic microsomal cytochrome P-450-dependent metabolism of retinoic acid after chronic ethanol consumption may contribute to the accelerated catabolism of retinoic acid in vivo.

Abstract States, regions, and municipalities have a growing importance in innovating policies to promote renewable sources of energy. This article examines the contribution of three state governments in developing and deploying wind and solar energy technologies in Brazil. The Brazilian electricity sector represents an interesting case of a middle-income country that is distinguished by strong federal involvement in energy governance and a reliance on hydroelectric power, followed by natural gas and coal. Using interviews conducted with policymakers and energy professionals, we find that regional energy transitions emerge as part of a process where state-level actors frame renewable energy choices primarily in terms of economic development opportunities and improving energy security. The engagement of regional institutions and organizations with energy priorities further influences the development of renewable technologies. The main policy implication is that state governments can have a strong role in the learning and niche formation of renewable alternatives that have been given less priority at the national level. This paper concludes that future policies should investigate how to scale up state renewable energy programs and initiatives.