775 research outputs found
Crystal effects in the Neutralization of He+ ions in the low energy ion scattering regime
4 pages.-- PACS nrs.: 34.35.+a, 68.47.De, 68.49.Sf, 79.20.Rf.Investigating possible crystal effects in ion scattering from elemental surfaces, measurements of the positive ion fraction P+ are reported for He+ ions scattered from single and polycrystalline Cu surfaces. In the Auger neutralization regime, the ion yield is determined by scattering from the outermost atomic layer. For Cu(110) P+ exceeds that for polycrystalline Cu by up to a factor of 2.5, thus exhibiting a strong crystal effect. It is much less pronounced at higher energies, i.e., in the reionization regime. However, there a completely different angular dependence of the ion yield is observed for poly- and single crystals, due to massive subsurface contributions in nonchanneling directions.This work was partially supported by the Austrian
Science Fund FWF, project number P16469.Peer reviewe
Crystal effects in the Neutralization of He+ ions in the low energy ion scattering regime
4 pages.-- PACS nrs.: 34.35.+a, 68.47.De, 68.49.Sf, 79.20.Rf.Investigating possible crystal effects in ion scattering from elemental surfaces, measurements of the positive ion fraction P+ are reported for He+ ions scattered from single and polycrystalline Cu surfaces. In the Auger neutralization regime, the ion yield is determined by scattering from the outermost atomic layer. For Cu(110) P+ exceeds that for polycrystalline Cu by up to a factor of 2.5, thus exhibiting a strong crystal effect. It is much less pronounced at higher energies, i.e., in the reionization regime. However, there a completely different angular dependence of the ion yield is observed for poly- and single crystals, due to massive subsurface contributions in nonchanneling directions.This work was partially supported by the Austrian
Science Fund FWF, project number P16469.Peer reviewe
Curvature-Induced Defect Unbinding in Toroidal Geometries
Toroidal templates such as vesicles with hexatic bond orientational order are
discussed. The total energy including disclination charges is explicitly
computed for hexatic order embedded in a toroidal geometry. Related results
apply for tilt or nematic order on the torus in the one Frank constant
approximation. Although there is no topological necessity for defects in the
ground state, we find that excess disclination defects are nevertheless
energetically favored for fat torii or moderate vesicle sizes. Some
experimental consequences are discussed.Comment: 12 pages, 15 eps figure
Field theoretic calculation of the surface tension for a model electrolyte system
We carry out the calculation of the surface tension for a model electrolyte
to first order in a cumulant expansion about a free field theory equivalent to
the Debye-H\"uckel approximation. In contrast with previous calculations, the
surface tension is calculated directly without recourse to integrating
thermodynamic relations. The system considered is a monovalent electrolyte with
a region at the interface, of width h, from which the ionic species are
excluded. In the case where the external dielectric constant epsilon_0 is
smaller than the electrolyte solution's dielectric constant epsilon we show
that the calculation at this order can be fully regularized. In the case where
h is taken to be zero the Onsager-Samaras limiting law for the excess surface
tension of dilute electrolyte solutions is recovered, with corrections coming
from a non-zero value of epsilon_0/epsilon.Comment: LaTeX, 14 pages, 3 figures, 1 tabl
An intimate collaboration between peroxisomes and lipid bodies
Although peroxisomes oxidize lipids, the metabolism of lipid bodies and peroxisomes is thought to be largely uncoupled from one another. In this study, using oleic acid–cultured Saccharomyces cerevisiae as a model system, we provide evidence that lipid bodies and peroxisomes have a close physiological relationship. Peroxisomes adhere stably to lipid bodies, and they can even extend processes into lipid body cores. Biochemical experiments and proteomic analysis of the purified lipid bodies suggest that these processes are limited to enzymes of fatty acid β oxidation. Peroxisomes that are unable to oxidize fatty acids promote novel structures within lipid bodies (“gnarls”), which may be organized arrays of accumulated free fatty acids. However, gnarls are suppressed, and fatty acids are not accumulated in the absence of peroxisomal membranes. Our results suggest that the extensive physical contact between peroxisomes and lipid bodies promotes the coupling of lipolysis within lipid bodies with peroxisomal fatty acid oxidation
Internet of Things vs Internet of Behavior: Trends in the Digital World
В данной статье рассматривается взаимосвязь понятий интернет вещей и интернет поведения, его использование в целях цифрового маркетинга. Проанализированы примеры успешности внедрения интернета поведения в жизнь людей.This article examines the relationship between the concepts of the Internet of Things and Internet behavior, its use for digital marketing purposes. The examples of the success of the introduction of the Internet of behavior into people's lives are analyzed
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