English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Context. Particles in protoplanetary disks go through a number of phases thatare dominated by collisions. In each of these events, grains exchangeelectrical charge via triboelectric effects. This enhances the stability ofparticle aggregates. Aim. Dielectric grains are easily charged by collisions.Here, we investigate whether a charge is capable of inducing an aggregation ofparticles and we consider how collision properties, such as ticking velocitiesand collisional cross-sections, are altered. Methods. We explored aggregationin microgravity experiments based on the observation of the motion ofsubmillimeter (submm) grains following many collisions. In the process, grainsattract each other, collide, stick, and ultimately form small aggregates.Results. We observed a bottom-up formation of irregular aggregates from submmgrains. While some of the observed trajectories during the approach of grainsreflect the presence of a pure Coulomb potential, the motion is not always inagreement with pure Kepler motion. Higher-order potentials of multipole chargedistributions stand as a plausible explanation for this behavior. An immediateconsequence of charging is that the particles continue to stick to each otherat velocities of $\sim 10 \, \rm cm/s,$ while surface forces of neutral grainsare only expected to allow sticking below $\sim 1 \, \rm mm/s$. No bouncingcollision was observed among hundreds of collisions in the given parameterrange. Applied to early phases of planet formation, the forming aggregates aretherefore the first steps in a new growth phase beyond the traditional bouncingbarrier in planet formation.

Observation of bottom-up formation for charged grain aggregates related to pre-planetary evolution beyond the bouncing barrier