It is shown that for the "standard" accretion disk model of the solar nebula, the efficiency of mixing the products of thermochemical processing from small to large disk radii depends only on the ratio of Djv = k (D = eddy diffusivity, v = eddy viscosity). In the steady state limit, where mixing is most efficient, the fractional contamination at radius R which is due to thermochemical processin...

The ability to tune the atomic-scale structural and chemical ordering in nanoalloy catalysts is essential for achieving the ultimate goal of high activity and stability of catalyst by design. This article demonstrates this ability with a ternary nanoalloy of platinum with vanadium and cobalt for oxygen reduction reaction in fuel cells. The strategy is to enable nanoscale alloying and structural...

In this study, we address the issues associated with predicting usefully accurate heats of formation for moderately-sized molecules such as corannulene and C(60). We obtain a high-level theoretical heat of formation for corannulene through the use of reaction schemes that conserve increasingly larger molecular fragments between the reactants and products. The reaction enthalpies are obtained by...

[1] As high-performance computing facilities and sophisticated modeling software become available, modeling mantle convection in a three-dimensional (3-D) spherical shell geometry with realistic physical parameters and processes becomes increasingly feasible. However, there is still a lack of comprehensive benchmark studies for 3-D spherical mantle convection. Here we present benchmark and test...

We are pleased that Dagan et al. have found an earlier reference (1) than Reiss (2), whom we cited (3), on the production of alternating single impulses in a network of model neurons. The general properties of reciprocally inhibitory neuronal networks are discussed by Sherrington (4), who in turn cites a number of 19th-century examples of similar alternating behaviors, both experimental and the...

To simulate emissions of nitrogen-containing compounds in practical combustion environments, it is necessary to have accurate values for their thermochemical parameters, as well as accurate kinetic values to describe the rates of their formation and decomposition. Significant disparity is observed in the literature for the former, and we therefore present herein high-accuracy ab initio gas-phas...

The gas-phase acidity and proton affinity of thymine, cytosine, and 1-methyl cytosine have been examined using both theoretical (B3LYP/6-31+G*) and experimental (bracketing, Cooks kinetic) methods. This paper represents a comprehensive examination of multiple acidic sites of thymine and cytosine and of the acidity and proton affinity of thymine, cytosine, and 1-methyl cytosine. Thymine exists a...

Chemical-looping water splitting is a novel and promising technology for hydrogen production with CO2 separation. Its efficiency and performance depend critically on the reduction and oxidation (redox) properties of the oxygen carriers (OC). Ceria is recognized as one of the most promising OC candidates, because of its fast chemistry, high ionic diffusivity, and large oxygen storage capacity. T...

This contribution is based on the monograph entitled “Recent Advances in Thermochemical Conversion of Biomass”, covering both general items as well as the primary processes, like fast pyrolysis, gasification, hydrothermal liquefaction, carbonization and secondary processes, like co-processing of bio-oil in fluidized catalytic cracking (FCC), Fischer-Tropsch synthesis and valorization of lignin ...

A thermochemical rather simple experimental technique is applied to determine the enthalpy of formation of Diperoxide of ciclohexanone. The study is complemented with suitable theoretical calculations at the semiempirical and ab initio levels. A particular satisfactory agreement between both ways is found for the ab initio calculation at the 6311G basis This set level. Some possible extensions ...