The driving effects of common atmospheric molecules for formation of prenucleation clusters: the case of sulfuric acid, formic acid, nitric acid, ammonia, and dimethyl amine.

How secondary aerosols form is critical as aerosols' impact on Earth's climate is one of the main sources of uncertainty for understanding global warming. The beginning stages for formation of prenucleation complexes, that lead to larger aerosols, are difficult to decipher experimentally. We present a computational chemistry study of the interactions between three different acid molecules and two different bases.

Probing the Free Energy of Small Water Clusters: Revisiting Classical Nucleation Theory.

By addressing the defects in classical nucleation theory (CNT), we develop an approach for extracting the free energy of small water clusters from nucleation rate experiments without any assumptions about the form of the cluster free energy. For temperatures higher than ∼250 K, the extracted free energies from experimental data points indicate that their ratio to the free energies predicted by CNT exhibits nonmonotonic behavior as the cluster size changes. We show that this ratio increases from almost zero for monomers and passes through (at least) one maximum before approaching one for large clusters.

Hydrogen-Bond Topology Is More Important Than Acid/Base Strength in Atmospheric Prenucleation Clusters.

We explored the hypothesis that on the nanoscale level, acids and bases might exhibit different behavior than in bulk solution. Our study system consisted of sulfuric acid, formic acid, ammonia, and water. We calculated highly accurate Domain-based Local pair-Natural Orbital- Coupled-Cluster/Complete Basis Set (DLPNO-CCSD(T)/CBS) energies on DFT geometries and used the resulting Gibbs free energies for cluster formation to compute the overall equilibrium constants for every possible cluster.

Physical characteristics of pig fat and their relation to fatty acid composition.

One hundred and five samples of pig backfat were assessed for appearance (colour and translucency) and hardness. The fatty acid profile of a selected subset of 50 samples was determined. Increased yellow colour was associated with increased linoleic and α-linolenic acid percentages.

Behaviour of 3-week weaned pigs in Straw-Flow(R), deep straw and flatdeck housing systems.

The behaviour of 3-week weaned pigs in different housing systems was examined as part of an assessment of the suitability of the Straw-Flow(R) system for pigs of this age. Three replicate pens of 20 pigs were weaned at 6.4 kg liveweight into each of: (a) deep-straw; (b) Straw-Flow(R); (c) large flatdeck; (d) small flatdeck.

Assessment of fermentation in growing pigs given unmolassed sugar-beet pulp: a stoichiometric approach.

In four experiments growing pigs were given a cereal-based diet alone or supplemented with unmolassed sugar-beet pulp (SBP), used as a model substrate for fermentation. The rates of production of methane and gaseous hydrogen were measured and, together with the molar proportions of volatile fatty acids (VFA) in the digesta, used in stoichiometric calculations of fermentation. The resulting estimates were only one-sixth of the observed extent of digestion of SBP.

A rearing system for colostrum-deprived neonatal piglets.

A system for the artificial rearing of colostrum-deprived neonatal piglets is described. A total of 443 piglets in 6 batches was reared. Each piglet, immediately after birth was placed in a separate incubator which was ventilated with heated filtered air.

Cylindroma and eccrine spiradenoma coexistent in the same lesion.

Two patients complained of having a tender nodule. One patient had the nodule on the scalp and the other on the face. Each nodule contained a cylindroma and an adjacent eccrine spiradenoma.