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...

Bioenergy will be one component of a suite of alternatives to fossil fuels. Effective conversion of biomass to energy will require the careful pairing of advanced conversion technologies with biomass feedstocks optimized for the purpose. Lignocellulosic biomass can be converted to useful energy products via two distinct pathways: enzymatic or thermochemical conversion. The thermochemical pathwa...

Widespread adoption of solar-thermochemical fuel production depends on its economic viability, largely driven by the efficiency of use of the available solar resource. Herein, we analyze the efficiency of two-step cycles for thermochemical hydrogen production, with emphasis on efficiency. Owing to water thermodynamics, isothermal H2 production is shown to be impractical and inefficient, irrespe...

Chloramines, bromamines, and bromochloramines are halogen-containing oxidants that arise from the reaction of hypohalous acids with ammonia in water. Although relevant to both water disinfection chemistry and biochemistry, these molecules are difficult to study in the laboratory, and their thermochemical properties remain poorly established. We developed a benchmark level ab initio calculation ...

The thermochemical properties for selected hydrogenated silicon clusters (Si(x)H(y), x = 3-13, y = 0-18) were calculated using quantum chemical calculations and statistical thermodynamics. Standard enthalpy of formation at 298 K and standard entropy and constant pressure heat capacity at various temperatures, i.e., 298-6000 K, were calculated for 162 hydrogenated silicon clusters using G3//B3LY...

Based on a phenomenological methodology, a three dimensional (3D) thermochemical model was developed to predict the temperature profile, the mass loss and the decomposition front of a carbon-reinforced epoxy composite laminate (T700/M21 composite) exposed to fire conditions. This 3D model takes into account the energy accumulation by the solid material, the anisotropic heat conduction, the ther...

In the present stady, thermochemical treatment in H2/NH3 atmosphere was used as a post-treatment for electroless Ni-P coatings on the AISI 4140 steel substrates. High phosphorus (9%) coatings with thicknesses of 2, 24 and 48 m were applied and the effects of the thermochemical treatment on the morphology, structural changes, roughness, hardness and wear resistance of coatings were studied b...