TDDFT Studie des Energie- und Ladungstransfers bei der Wechselwirkung von Ionen mit Festkörperoberflächen

The investigation of processes at the interface between a plasma and a solid surface is of high interest to many different research areas with a vast variety of technical applications. These extend from electronics, surface chemistry and fusion research, to medicine, pharmacy and many more. However, an accurate understanding of the fundamental processes at the plasma-solid interface is often missing. One approach towards a more detailed understanding is to isolate the interaction of atoms, ions, or molecules with the surface and perform scattering experiments. Of special interest are low energy and hyperthermal projectiles with kinetic energies starting in the order of chemical binding energies (in the order of 1 eV) where projectiles are too slow to destroy or sputter the surface but contribute themselves enough energy to cause notable excitations within the electronic system. In this work, time-dependent density-functional theory (TDDFT) simulations have been employed together with Ehrenfest molecular dynamics (MD) as implemented in the Octopus code to investigate the charge and energy transfer between hyperthermal ions and metal surfaces. The focus of this work lies on the resonant neutralization of protons (H+) interacting with an Al(111) surface. The surface is modeled by a cluster geometry. Of major importance to TDDFT-MD simulations is the the quality of the approximation applied to the exchange-correlation potential which is investigated and discussed in detail. Also, difficulties connected with the spin-polarization within the calculations are analyzed. Furthermore, the neutralization process is studied, neutralization distances are determined and the energy transfer into electronic, kinetic and phononic degrees of freedom is analyzed. It has been found that the difference in initial kinetic energy between H+ and H0 projectiles ..

Implications of the Global Surface Fault Distribution and of Lithospheric Cooling

This contribution presents a model that links the observed distribution of surface faults to the spatial distribution of marsquakes. The annual seismic moment budget is computed based on the as-sumption that global cooling and subsequent shrink-ing of Mars is the main source of strain today [1]. A truncated Gutenberg-Richter distribution is used to re-late the seismic moment budget to marsquake frequen-cies. We have derived a theoretical relation for the limitation of quake size by the lengths of the individual faults. This relation is used for the simulation of epi-center catalogs that may serve as input data for the development of seismological experiments

The Kinesin‐3 motor, KLP‐4, mediates axonal organization and cholinergic signaling in Caenorhabditis elegans

Microtubule plus‐end directed trafficking is dominated by kinesin motors, yet kinesins differ in terms of cargo identity, movement rate, and distance travelled. Functional diversity of kinesins is especially apparent in polarized neurons, where long distance trafficking is required for efficient signal transduction‐behavioral response paradigms. The Kinesin‐3 superfamily are expressed in neurons and are hypothesized to have significant roles in neuronal signal transduction due to their high processivity. Although much is known about Kinesin‐3 motors mechanistically in vitro, there is little known about their mechanisms in vivo. Here, we analyzed KLP‐4, the Caenorhabditis elegans homologue of human KIF13A and KIF13B. Like other Kinesin‐3 superfamily motors, klp‐4 is highly expressed in the ventral nerve cord command interneurons of the animal, suggesting it might have a role in controlling movement of the animal. We characterized an allele of klp‐4 that contains are large indel in the cargo binding domain of the motor, however, the gene still appears to be expressed. Behavioral analysis demonstrated that klp‐4 mutants have defects in locomotive signaling, but not the strikingly uncoordinated movements such as those found in unc‐104/KIF1A mutants. Animals with this large deletion are hypersensitive to the acetylcholinesterase inhibitor aldicarb but are unaffected by exogenous serotonin. Interestingly, this large klp‐4 indel does not affect gross neuronal development but does lead to aggregation and disorganization of RAB‐3 at synapses. Taken together, these data suggest a role for KLP‐4 in modulation of cholinergic signaling in vivo and shed light on possible in vivo mechanisms of Kinesin‐3 motor regulation

Dealings between Cataract and Retinal Reattachment Surgery in PVR

Introduction. To evaluate the impact of the eye lens status and oil side effects on the outcome of vitreoretinal surgery in retinal detachment with proliferative vitreoretinopathy (PVR) and a temporary silicone oil tamponade (SOT). Methods. 101 eyes were analyzed retrospectively and 103 eyes prospectively in regard to their retinal reattachment success rate and key factors for the outcome. Subgroup analysis of 27 eyes with Scheimpflug lens photography (SLP) before and after retinal reattachment service with SOT was performed. For SLP (65% phakic eyes) a Pentacam densitometry reference body with 3 mm diameter was chosen and 3 segments (anterior/mid/posterior) were evaluated separately after a quality check. Results. The retinal reattachment rate was highest in the prospective pseudophakic group (p=0.039). Lens transparency loss occurred earlier in middle aged patients than in younger patients. Besides the nucleus, layers posterior and anterior to it showed specific transparency changes. The emulsification rate was higher when eyes had been operated on in the anterior chamber before retinal reattachment service. Conclusions. Retinal reattachment surgery seems to benefit from preoperative cataract removal. We found significant lens changes in the nucleus as well as in the layers anterior and posterior to it. This corresponds to the histology of the lens epithelium published before

Transverse tests of I-beams and other structural shapes

Thesis (B.S.)--University of Illinois, 1910.Ms.Includes bibliographical references (leaf 12)

Konrad Witz, la Savoie et l'Italie. Nouvelles hypothèses à propos du retable de Genève

Deuchler Florens. Konrad Witz, la Savoie et l'Italie. Nouvelles hypothèses à propos du retable de Genève. In: Revue de l'Art, 1986, n°71. pp. 7-16