A self-consistent estimation method for the thermochemical properties of polycyclic aromatic hydrocarbons (PAH) is presented. This method is based on enthalpies of formation (DeltaHf(degrees), entropies (S(degrees)298, and heat capacities (C(degrees)p obtained from B3LYP/6-31G(d) calculations of the total energies and frequencies for 139 PAHs, including C(60) and C(70) fullerenes. The enthalpie...

The product and process parameters that determine successful freeze-drying are described and their interrelationships are explored. It is shown that the thermochemical and thermomechanical properties of water-soluble, amorphous materials form the basis of effective formulation design and that coordinated approaches to formulation and process development achieve optimum results with a minimum of...

W3C standardized Web Services are becoming an increasingly popular middleware technology used to facilitate the open exchange of chemical data. While several projects in existence use Web Services to wrap existing commercial and open-source tools that mine chemical structure data, no Web Service infrastructure has yet been developed to compute thermochemical properties of substances. This work ...

In this article, we present a new database of thermodynamic properties for polycyclic aromatic hydrocarbons (PAH). These large aromatic species are formed in very rich premixed flames and in diffusion flames as part of the gas-phase chemistry. PAH are commonly assumed to be the intermediates leading to soot formation. Therefore, accurate prediction of their thermodynamic properties is required ...

Cerium dioxide, CeO2-δ, remains one of the most attractive materials under consideration for solar-driven thermochemical production of chemical fuels. Understanding the rate-limiting factors in fuel production is essential for maximizing the efficacy of the thermochemical process. The rate of response is measured here via electrical conductance relaxation methods using porous ceria structures w...

Process intensification (PI) technologies represent all approaches leading to size reduction and efficiency improvement of process equipment. Thermal energy storage (TES) systems are key elements in renewable and recovery thermal energy deployments, and their performance can benefit from PI principles. This study covers a brief analysis and state of the art of several PI technologies applied to...

The typical result of gas phase chemical investigations on a one-atom-at-a-time level are standard adsorption enthalpies (∆Hads) of chemical species on stationary chromatographic surfaces. The standard adsorption enthalpies are deduced from experimental results using either the model of linear gas chromatography assuming mobile adsorption [1] or Monte-Carlo based models [2]. The obtained enthal...

Hydration reactions of sodiated and potassiated nucleic acid bases (uracil, thymine, cytosine, and adenine) produced by electrospray have been studied in a gas phase using the pulsed ion-beam high-pressure mass spectrometer. The thermochemical properties, ΔH(o)(n), ΔS(o)(n), and ΔG(o)(n), for the hydrated systems were obtained from hydration equilibrium measurement. The structural aspects of th...

in the present study, the interactions of three different lithium species li+, li3+ and ch3li with several different sites of the most stable tautomers of dna nucleo-bases are presented. this investigation is based on the results of thermochemical properties, quantum theory of atoms in molecules (qtaim) and natural bond orbital (nbo) analysis, obtained at b3lyp/6-311++g(d,p) level of theory. th...

The thermochemical properties ΔH(o)(n), ΔS(o)(n), and ΔG(o)(n) for the hydration of sodiated and potassiated monosaccharides (Ara = arabinose, Xyl = xylose, Rib = ribose, Glc = glucose, and Gal = galactose) have been experimentally studied in the gas phase at 10 mbar by equilibria measurements using an electrospray high-pressure mass spectrometer equipped with a pulsed ion beam reaction chamber...