Sputtering of Mo and Ag with xenon ions from a radio-frequency ion thruster.

The goal of this work is to set up an electric propulsion (EP) sputtering test section as a feasibility study for ground-based sputter testing of spacecraft materials with a radio-frequency ion thruster. Such experiments deliver valuable data, which are scarce but highly desired to model EP-based space missions, for example, with the Spacecraft Plasma Interaction System in order to predict the performance and lifetime of spacecraft components. This study assessed if sufficient testing conditions can be met to produce reliable experimental material data in the future.

Organ growth without cell division: somatic polyploidy in a moth, Ephestia kuehniella.

Organ growth depends on cell division and (or) cell growth. Here, we present a study on two organs whose growth depends entirely on cell growth, once they are formed in the embryo: Malpighian tubules and silk glands of the flour moth, Ephestia kuehniella . Between first and last larval instar, the volume of Malpighian tubule cells increases by a factor of ∼1800 and that of silk gland cells by a factor of ∼3100.