radiation enhanced diffusion at the surface of metals has been observed and studied for low-energy nitrogen ions at the surface of copper. the displacement of the target atoms during irradiation creates vacancies and other defects near the surface, thus enhancing the diffusion of implanted materials toward the surface and also into the solid. the mechanism has been studied here by a special met...

Steven D. Allison Department of Ecology and Evolutionary Biology, University of California, Irvine, CA 92697, USA Correspondence: E-mail: [email protected] Abstract Extracellular enzymes allow microbes to acquire carbon and nutrients from complex molecules and catalyse the rate-limiting step in nutrient mineralization. Because the factors regulating enzyme production are poorly understood, I use...

BACKGROUND Nitrous oxide diffuses easily from blood into air filled spaces. Xenon is also a relatively insoluble gas, like nitrous oxide. Therefore, the authors measured xenon diffusion into obstructed bowel segments during xenon anesthesia and compared this with nitrous oxide and nitrogen diffusion. METHODS Twenty-one pentobarbital-anesthetized pigs were randomly assigned to three groups to ...

The accurate knowledge of transport properties of pure and mixture fluids is essential for the design of various chemical and mechanical systems that include fluxes of mass, momentum, and energy. In this study we determine the mutual diffusion coefficients of mixtures composed of heptane isomers and nitrogen using molecular dynamics (MD) simulations with fully atomistic intermolecular potential...

Whales are unique in that the supply of blood to the brain is not by the internal carotid arteries, but by way of thoracic and intra-vertebral arterial retia. We found in the harbor porpoise (Phocoena phocoena) that these retia split up into smaller anastomosing vessels and thin-walled sinusoid structures that are embedded in fat. The solubility of nitrogen is at least six times larger in fat t...