scholarly journals System-level fractionation of carbon from disk and planetesimal processing 

2021 ◽  
Author(s):  
Tim Lichtenberg ◽  
Sebastiaan Krijt
Keyword(s):  
Planetary System ◽  
Numerical Models ◽  
Planetary Systems ◽  
Building Blocks ◽  
Environmental Context ◽  
System Level ◽  
Circumstellar Disk ◽  
Internal Heating ◽  
Compositional Evolution ◽  
Total Budget

<div class="page" title="Page 1"> <div class="section"> <div class="layoutArea"> <div class="column"> <p>Finding and characterizing extrasolar Earth analogs will rely on interpretation of the planetary system’s environmental context. The total budget and fractionation between C–H–O species sensitively affect the climatic and geodynamic state of terrestrial worlds, but their main delivery channels are poorly constrained. We connect numerical models of volatile chemistry and pebble coagulation in the circumstellar disk with the internal compositional evolution of planetesimals during the primary accretion phase. Our simulations demonstrate that disk chemistry and degassing from planetesimals operate on comparable timescales and can fractionate the relative abundances of major water and carbon carriers by orders of magnitude. As a result, individual planetary systems with significant planetesimal processing display increased correlation in the volatile budget of planetary building blocks relative to no internal heating. Planetesimal processing in a subset of systems increases the variance of volatile contents across planetary systems. Our simulations thus suggest that exoplanetary atmospheric compositions may provide constraints on <em>when</em> a specific planet formed.</p> </div> </div> </div> </div>

scholarly journals The Story of Planets: Anchoring Numerics in Reality

2013 ◽  
Vol 8 (S299) ◽  
pp. 123-130
Author(s):  
Zoë M. Leinhardt
Keyword(s):  
Numerical Simulations ◽  
Extrasolar Planets ◽  
Planet Formation ◽  
Planetary System ◽  
Numerical Models ◽  
Building Blocks ◽  
Solar Mass ◽  
Hot Jupiters ◽  
Planetary Cores ◽  
Low Mass

AbstractBuilding a complete coherent model of planet formation has proven difficult. There are gaps in the observational record, difficult physical processes that we have yet to fully understand, such as planetesimal formation, and an extensive list of observationally determined constraints that the model must fulfil. For example, the diversity of extrasolar planets detected to date is staggering – from single hot-Jupiters to multiple planet systems with several tightly packed super-Earths. In addition, the characteristics of the host stars are broad from single solar-mass stars to tight binaries and low mass, low metalicity stars. Even more surprising, perhaps, is the frequency of detection and thus, the implied efficiency of the planet formation process. Any theoretical model must not just be able to explain how planets form but must also explain the frequency and diversity of planetary systems. So why is planet formation so prolific? What parameters determine the type of planetary system that will result? How important are the initial parameters of the protoplanetary disk, such as composition, versus stochastic effects, such as gravitational scattering events, that occur during the evolution of the planetary system?Current observations of extrasolar planets provide snapshots in time of the earliest and latest stages of planet formation but do not show the evolution between the two. It is at this point that we must rely on numerical models to evolve proto-planetary disks into planets. But how can we validate the results of our numerical simulations if the middle stages of planet formation are effectively invisible? Collisions are a core component of planet formation. Planetesimals, the building blocks of planets, collide with one another as they grow and evolve into planets or planetary cores and are viscously stirred by larger protoplanets and fully-formed planets. The range of impact parameters encountered during growth from planetesimals to planets span multiple collision outcome regimes: cratering, merging, disruption, and hit-and-run events. Most of these collisions produce significant debris and dust. If we have a good understanding of the production of collisional debris we can use it as an indirect tracer of on-going planetary evolution even if the planets themselves are not directly detectable.In this paper I will show how numerical simulations of planet formation including realistic collision modelling can be used to predict, and be constrained by, observations.

Capabilities

2018 ◽  
Author(s):  
Paul F. M. J. Verschure
Keyword(s):  
Building Blocks ◽  
Living Systems ◽  
System Level ◽  
Cognitive Architectures ◽  
Multiple Components ◽  
Perception Action

This chapter introduces the “Capabilities” section of the Handbook of Living Machines. Where the previous section considered building blocks, we recognize that components or modules do not automatically make systems. Hence, in the remainder of this handbook, the emphasis is toward the capabilities of living systems and their emulation in artifacts. Capabilities often arise from the integration of multiple components and thus sensitize us to the need to develop a system-level perspective on living machines. Here we summarize and consider the 14 contributions in this section which cover perception, action, cognition, communication, and emotion, and the integration of these through cognitive architectures into systems that can emulate the full gamut of integrated behaviors seen in animals including, potentially, our own capacity for consciousness.

scholarly journals DESTINY: Database for the Effects of STellar encounters on dIsks and plaNetary sYstems

2019 ◽  
Vol 6 (1) ◽  
Author(s):  
Asmita Bhandare ◽  
Susanne Pfalzner
Keyword(s):  
Planetary System ◽  
Planetary Systems ◽  
Gravitational Effect ◽  
Parameter Study ◽  
Orbital Inclination ◽  
Particle Properties ◽  
Disk Size ◽  
Stellar Group ◽  
Cluster Environment ◽  
Parabolic Orbits

Abstract Most stars form as part of a stellar group. These young stars are mostly surrounded by a disk from which potentially a planetary system might form. Both, the disk and later on the planetary system, may be affected by the cluster environment due to close fly-bys. The here presented database can be used to determine the gravitational effect of such fly-bys on non-viscous disks and planetary systems. The database contains data for fly-by scenarios spanning mass ratios between the perturber and host star from 0.3 to 50.0, periastron distances from 30 au to 1000 au, orbital inclination from 0∘ to 180∘ and angle of periastron of 0∘, 45∘ and 90∘. Thus covering a wide parameter space relevant for fly-bys in stellar clusters. The data can either be downloaded to perform one’s own diagnostics like for e.g. determining disk size, disk mass, etc. after specific encounters, obtain parameter dependencies or the different particle properties can be visualized interactively. Currently the database is restricted to fly-bys on parabolic orbits, but it will be extended to hyperbolic orbits in the future. All of the data from this extensive parameter study is now publicly available as DESTINY.

scholarly journals Seismic Constraint on the Plausible Explanations of the Metal Rich Feature of Planetary System Stars

2002 ◽  
Vol 185 ◽  
pp. 486-489
Author(s):  
H. Shibahashi ◽  
S. Watanabe
Keyword(s):  
Planetary System ◽  
Planetary Systems ◽  
Solar Interior ◽  
Abundance Distribution ◽  
Spectroscopic Observations ◽  
Metal Abundance ◽  
The Rich

AbstractFrom Spectroscopic observations showing that the parent stars of planetary systems are metal rich, it is suspected that this feature results from the accompanying planetary system. With the rich helioseismic data so far obtained, we determine the metal abundance distribution in the solar interior with respect to the distance from the center. This result gives constraints on the possible explanations about the metal rich feature of the stars accompanied by a planetary system.

scholarly journals Turning solar systems into extrasolar planetary systems in stellar clusters

2010 ◽  
Vol 6 (S276) ◽  
pp. 304-307
Author(s):  
Melvyn B. Davies
Keyword(s):  
Solar System ◽  
Planetary System ◽  
Large Fraction ◽  
Planetary Systems ◽  
Single Star ◽  
Solar Systems ◽  
Close Encounters ◽  
Eccentric Orbits ◽  
The Galaxy ◽  
Hostile Environments

AbstractMany stars are formed in some form of cluster or association. These environments can have a much higher number density of stars than the field of the galaxy. Such crowded places are hostile environments: a large fraction of initially single stars will undergo close encounters with other stars or exchange into binaries. We describe how such close encounters and exchange encounters will affect the properties of a planetary system around a single star. We define singletons as single stars which have never suffered close encounters with other stars or spent time within a binary system. It may be that planetary systems similar to our own solar system can only survive around singletons. Close encounters or the presence of a stellar companion will perturb the planetary system, leading to strong planet-planet interactions, often leaving planets on tighter and more eccentric orbits. Thus, planetary systems which initially resembled our own solar system may later more closely resemble the observed extrasolar planetary systems.

scholarly journals A social network of collaborating industrial assets

2018 ◽  
Vol 232 (4) ◽  
pp. 389-400 ◽  
Author(s):  
Hao Li ◽  
Adrià Salvador Palau ◽  
Ajith Kumar Parlikad
Keyword(s):  
Social Networks ◽  
Social Network ◽  
Industrial Revolution ◽  
Building Blocks ◽  
System Level ◽  
Industrial Systems ◽  
Traffic Routing ◽  
Status Data ◽  
General Architecture ◽  
Level Performance

The IoT (Internet of Things) concept is being widely regarded as the fundamental tool of the next industrial revolution – Industry 4.0. As the value of data generated in social networks has been increasingly recognised, social media and the IoT have been integrated in areas such as product-design, traffic routing, etc. However, the potential of this integration in improving system-level performance in industrial environments has rarely been explored. This paper discusses the feasibility of improving system-level performance in industrial systems by integrating social networks into the IoT concept. We propose the concept of a social internet of industrial assets (SIoIA) which enables the collaboration between assets by sharing status data. We also identify the building blocks of SIoIA and characteristics of one of its important components – social assets. A sketch of the general architecture needed to enable a social network of collaborating industrial assets is proposed and two illustrative application examples are given.

Concept Design of Very Large Floating Structures and Laboratory-Scale Physical Modelling

2019 ◽  
Author(s):  
Lorenzo Cappietti ◽  
Irene Simonetti ◽  
Ilaria Crema
Keyword(s):  
Numerical Models ◽  
Physical Modelling ◽  
Building Blocks ◽  
Small Scale ◽  
World Population ◽  
Concept Design ◽  
Wave Loads ◽  
Experimental Database ◽  
Floating Structures ◽  
Very Large Floating Structures

Abstract The use of Very Large Floating Structures, VLFS, may represent a strategic approach in order to cope with some of the future societal challenges arising from the impressive growth of the world population. In this article, the motivations of this perspective are briefly discussed, the main issues for the development of VLFS are summarized and a concept structural design based on building-blocks technology is proposed. A small-scale physical model was manufactured and tested in the wave-current flume of the Laboratory of Maritime Engineering, LABIMA, of the Florence University, Italy. The aim of this study is the assessment of the structural feasibility and the effectiveness of the proposed VLFS concept, in terms of resistance to wave loads and control of floating behavior. The experimental measurements provide a first contribution to the necessary knowledge, about load magnitudes and floating behavior, for sizing some of the key structural components. The results appear to support the feasibility of the system in terms of usage of structural materials, technical components and building technologies, available at present, that can withstand the measured loads. Moreover, the acquired experimental database is fundamental in order to validate numerical models, in the perspective of using also such tools as complementary methodology for further improvement of the knowledge of design issues.

scholarly journals New HST data and modeling reveal a massive planetesimal collision around Fomalhaut

2020 ◽  
Vol 117 (18) ◽  
pp. 9712-9722 ◽  
Author(s):  
András Gáspár ◽  
George H. Rieke
Keyword(s):  
Planetary System ◽  
Hubble Space Telescope ◽  
Dust Cloud ◽  
Planetary Systems ◽  
Orbital Evolution ◽  
Published Data ◽  
Space Telescope ◽  
Gravitational Perturbations ◽  
Extrasolar Planetary System

The apparent detection of an exoplanet orbiting Fomalhaut was announced in 2008. However, subsequent observations of Fomalhaut b raised questions about its status: Unlike other exoplanets, it is bright in the optical and nondetected in the infrared, and its orbit appears to cross the debris ring around the star without the expected gravitational perturbations. We revisit previously published data and analyze additional Hubble Space Telescope (HST) data, finding that the source is likely on a radial trajectory and has faded and become extended. Dynamical and collisional modeling of a recently produced dust cloud yields results consistent with the observations. Fomalhaut b appears to be a directly imaged catastrophic collision between two large planetesimals in an extrasolar planetary system. Similar events should be very rare in quiescent planetary systems of the age of Fomalhaut, suggesting that we are possibly witnessing the effects of gravitational stirring due to the orbital evolution of hypothetical planet(s) around the star.

scholarly journals The planet companion around β Pictoris

2010 ◽  
Vol 6 (S276) ◽  
pp. 60-63
Author(s):  
Anne-Marie Lagrange ◽  
Mickaël Bonnefoy ◽  
Gael Chauvin ◽  
Daniel Apai ◽  
David Ehrenreich ◽  
...  
Keyword(s):  
Planetary System ◽  
Giant Planet ◽  
Planetary Systems ◽  
System Formation

AbstractThe β Pic disk of dust and gas has been regarded as the prototype of young planetary systems since the 1980s and has revealed over the years an impressive amount of indirect signs pointing toward the presence of at least one giant planet. We present here the recently detected first giant planet around this star. We show how this planet could explain some very peculiar features of the star environment (disk, spectroscopic variability), and how it constrains the scenarios of planetary system formation (timescales, mechanisms).

Slip System Interaction Matrix and its Influence on the Macroscopic Response of Al Alloys

2014 ◽  
Vol 794-796 ◽  
pp. 566-571 ◽  
Author(s):  
Mikhail Khadyko ◽  
Stéphane Dumoulin ◽  
Odd Sture Hopperstad
Keyword(s):  
Dislocation Density ◽  
Slip System ◽  
Numerical Models ◽  
Internal Variable ◽  
Relative Strength ◽  
Al Alloys ◽  
System Level ◽  
Interaction Matrix ◽  
Slip Systems ◽  
Crystal Plasticity Theory

In numerical models based on the crystal plasticity theory, various rules are implemented to describe hardening on the slip system level. The rules used are often variations of the Mecking-Kocks law, where the statistically stored dislocation density is the single internal variable. The dislocation density evolution equation consists of two terms representing accumulation and annihilation of dislocations. The accumulation term depends on a scalar parameter and an interaction matrix, which describes the contribution of all slip systems to the accumulation of the dislocations on a given slip system. Physically this matrix represents the relative strength of various dislocation locks which form when dislocations from different slip systems interact. The numerical values of the elements of the interaction matrix are rather hard to establish, but this has been done experimentally for different alloys and also based on numerical simulations. The obtained values, found in literature, are very different from each other. We use some new experimental data in an attempt to establish the influence of the numerical values of the elements of the interaction matrix on the hardening of a polycrystal.

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