Impact of vertical gas accretion on the carbon-to-oxygen ratio of gas giant atmospheres

Recent theoretical, numerical, and observational works have suggested that when a growing planet opens a gap in its disk the flow of gas into the gap is dominated by gas falling vertically from a height of at least one gas scale height. Our primary objective is to include, for the first time, the chemical impact that accreting gas above the midplane will have on the resulting carbon-to-oxygen ratio (C/O). We compute the accretion of gas onto planetary cores beginning at different disk radii and track the chemical composition of the gas and small icy grains to predict the resulting C/O in their atmospheres. In our model, all of the planets which began their evolution inward of 60 AU open a gap in the gas disk, and hence are chemically affected by the vertically accreting gas. Two important conclusions follow from this vertical flow: (1) more oxygen-rich icy dust grains become available for accretion onto the planetary atmosphere; (2) the chemical composition of the gas dominates the final C/O of planets in the inner (<20 AU) part of the disk. This implies that with the launch of the James Webb Space Telescope we can trace the disk material that sets the chemical composition of exoplanetary atmospheres.

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Connecting planet formation and astrochemistry

Astronomy and Astrophysics ◽

10.1051/0004-6361/201936105 ◽

2019 ◽

Vol 632 ◽

pp. A63 ◽

Cited By ~ 12

Author(s):

Alex J. Cridland ◽

Ewine F. van Dishoeck ◽

Matthew Alessi ◽

Ralph E. Pudritz

Keyword(s):

Solar System ◽

Planet Formation ◽

Water Ice ◽

Hot Jupiters ◽

Formation History ◽

General Mass ◽

Exoplanetary Atmospheres ◽

Molecular Abundances ◽

Gas Accretion ◽

Oxygen Ratio

To understand the role that planet formation history has on the observable atmospheric carbon-to-oxygen ratio (C/O) we have produced a population of astrochemically evolving protoplanetary disks. Based on the parameters used in a pre-computed population of growing planets, their combination allows us to trace the molecular abundances of the gas that is being collected into planetary atmospheres. We include atmospheric pollution of incoming (icy) planetesimals as well as the effect of refractory carbon erosion noted to exist in our own solar system. We find that the carbon and oxygen content of Neptune-mass planets are determined primarily through solid accretion and result in more oxygen-rich (by roughly two orders of magnitude) atmospheres than hot Jupiters, whose C/O are primarily determined by gas accretion. Generally we find a “main sequence” between the fraction of planetary mass accreted through solid accretion and the resulting atmospheric C/O; planets of higher solid accretion fraction have lower C/O. Hot Jupiters whose atmospheres have been chemically characterized agree well with our population of planets, and our results suggest that hot-Jupiter formation typically begins near the water ice line. Lower mass hot Neptunes are observed to be much more carbon rich (with 0.33 ≲ C/O ≲ 1) than is found in our models (C/O ~ 10−2), and suggest that some form of chemical processing may affect their observed C/O over the few billion years between formation and observation. Our population reproduces the general mass-metallicity trend of the solar system and qualitatively reproduces the C/O metallicity anti-correlation that has been inferred for the population of characterized exoplanetary atmospheres.

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Chemical Composition of Volatile Oil from Cinnamomum zeylanicum Buds

Zeitschrift für Naturforschung C ◽

10.1515/znc-2002-11-1206 ◽

2002 ◽

Vol 57 (11-12) ◽

pp. 990-993 ◽

Cited By ~ 35

Author(s):

Guddadarangavvanahally K. Jayaprakasha ◽

Lingamallu Jaganmohan Rao ◽

Kunnumpurath K. Sakariah

Keyword(s):

Chemical Composition ◽

Volatile Oil ◽

Cinnamomum Zeylanicum ◽

First Time

The hydro-distilled volatile oil of the Cinnamomum zeylanicum (C. zeylanicum) buds was analyzed using GC and GC-MS for the first time. Thirty-four compounds representing ≈ 98% of the oil was characterized. It consists of terpene hydrocarbons (78%) and oxygenated terpenoids (9%). α-Bergamotene (27.38%) and α-copaene (23.05%) are found to be the major compounds. A comparison of the chemical composition of the oil was made with that of flowers and fruits.

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Towards a better understanding of the origins, chemical composition and aging of oxygenated organic aerosols: case study of a Mediterranean industrialized environment, Marseille

Atmospheric Chemistry and Physics ◽

10.5194/acp-13-7875-2013 ◽

2013 ◽

Vol 13 (15) ◽

pp. 7875-7894 ◽

Cited By ~ 54

Author(s):

I. El Haddad ◽

B. D'Anna ◽

B. Temime-Roussel ◽

M. Nicolas ◽

A. Boreave ◽

...

Keyword(s):

Chemical Composition ◽

Organic Aerosols ◽

Industrial Emissions ◽

Aerosol Mass Spectrometer ◽

Statistical Confidence ◽

Aerosol Mass ◽

Novel Approach ◽

Organic Markers ◽

The Impact ◽

First Time

Abstract. As part of the FORMES summer 2008 experiment, an Aerodyne compact time-of-flight aerosol mass spectrometer (cToF-AMS) was deployed at an urban background site in Marseille to investigate the sources and aging of organic aerosols (OA). France's second largest city and the largest port in the Mediterranean, Marseille, provides a locale that is influenced by significant urban industrialized emissions and an active photochemistry with very high ozone concentrations. Particle mass spectra were analyzed by positive matrix factorization (PMF2) and the results were in very good agreement with previous apportionments obtained using a chemical mass balance (CMB) approach coupled to organic markers and metals (El Haddad et al., 2011a). AMS/PMF2 was able to identify for the first time, to the best of our knowledge, the organic aerosol emitted by industrial processes. Even with significant industries in the region, industrial OA was estimated to contribute only ~ 5% of the total OA mass. Both source apportionment techniques suggest that oxygenated OA (OOA) constitutes the major fraction, contributing ~ 80% of OA mass. A novel approach combining AMS/PMF2 data with 14C measurements was applied to identify and quantify the fossil and non-fossil precursors of this fraction and to explicitly assess the related uncertainties. Results show with high statistical confidence that, despite extensive urban and industrial emissions, OOA is overwhelmingly non-fossil, formed via the oxidation of biogenic precursors, including monoterpenes. AMS/PMF2 results strongly suggest that the variability observed in the OOA chemical composition is mainly driven in our case by the aerosol photochemical age. This paper presents the impact of photochemistry on the increase of OOA oxygenation levels, formation of humic-like substances (HULIS) and the evolution of α-pinene SOA (secondary OA) components.

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Soil and Leaf Nutrients Drivers on the Chemical Composition of the Essential Oil of Siparuna muricata (Ruiz & Pav.) A. DC. from Ecuador

Molecules ◽

10.3390/molecules26102949 ◽

2021 ◽

Vol 26 (10) ◽

pp. 2949

Author(s):

Juan I. Burneo ◽

Ángel Benítez ◽

James Calva ◽

Pablo Velastegui ◽

Vladimir Morocho

Keyword(s):

Gas Chromatography ◽

Chemical Composition ◽

Secondary Metabolites ◽

Essential Oil ◽

Chemical Elements ◽

Climatic Conditions ◽

Gas Chromatography Mass Spectrometry ◽

Chemical Compositions ◽

Leaf Nutrients ◽

First Time

Chemical compositions of plants are affected by the initial nutrient contents in the soil and climatic conditions; thus, we analyzed for the first time the effects of soil and leaf nutrients on the compositions of the essential oils (EOs) of Siparuna muricata in four different localities in Ecuador. EOs were obtained by hydrodistillation and analyzed by gas chromatography/mass spectrometry (GC/MS) and a gas chromatography/flame ionization detector (GC/FID). Enantiomeric distribution by GC/MS was determined, modifying the enantiomeric separation of β-pinene, limonene, δ-elemene, β-bourbonene, cis-cadina-1 (6), 4-diene and atractylone. A total of 44 compounds were identified. The most representative for L1 were guaiol, atractylone and 4-diene; for L2, cis-cadina-1(6),4-diene and myrcene; for L3, atractylone, myrcene and germacrene B; and finally, L4 germacrene B, myrcene and cis-cadina-1(6),4-diene. Correlations between soil- leaf chemical elements such as Al, Ca, Fe, Mg, Mn, N and Si in the different localities were significant with chemical composition of the essential oil of Siparuna muricata; however, correlations between soil and leaf K, P, and Na were not significant. Cluster and NMDS analysis showed high dissimilarity values of secondary metabolites between four localities related with changes in soil- leaf nutrients. Thus, the SIMPER routine revealed that not all secondary metabolites contribute equally to establishing the differences in the four localities, and the largest contributions are due to differences in guaiol, cis-cadina-1(6),4-diene, atractylone and germacrene. Our investigation showed for the first time the influences of altitude and soil- leaf chemical elements in the chemical composition of the EOs of S. muricata.

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New species, records, and immature stages of Chimarra Stephens (Trichoptera: Philopotamidae) from Campos Amazônicos National Park, northern Brazil

Zootaxa ◽

10.11646/zootaxa.4500.2.6 ◽

2018 ◽

Vol 4500 (2) ◽

pp. 258

Author(s):

GLEISON ROBSON DESIDÉRIO ◽

PATRIK BARCELOS-SILVA ◽

NEUSA HAMADA

Keyword(s):

New Species ◽

Aquatic Insects ◽

National Park ◽

Primary Objective ◽

Immature Stages ◽

Male Adult ◽

Northern Brazil ◽

Amazonas State ◽

First Time ◽

A New Species

Campos Amazônicos National Park is a federal conservation unit that contains part of the largest Cerrado refuge in the southern part of Brazilian Amazonia. Recently, during a survey of aquatic insects in the park, specimens of the caddisfly genus Chimarra were collected. The primary objective of this paper, as a result of this effort, is to describe and illustrate the male adult of a new species in Chimarra (Chimarrita), Chimarra singularis sp. nov., and the immature stages of Chimarra usitatissima Flint 1971. Additionally, the distributions of C.(Chimarrita) akantha Blahnik 1997 and C. (Curgia) jugescens Flint 1998 are extended to the southern part of Amazonas state, and C. (Chimarrita) heppneri Blahnik 1997 is recorded for the first time in northern Brazil.

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Microscopic Fungi in Big Cities: Biodiversity, Source, and Relation to Pollution by Potentially Toxic Metals

Atmosphere ◽

10.3390/atmos12111471 ◽

2021 ◽

Vol 12 (11) ◽

pp. 1471

Author(s):

Maria V. Korneykova ◽

Anastasia S. Soshina ◽

Andrey I. Novikov ◽

Kristina V. Ivashchenko ◽

Olesya I. Sazonova ◽

...

Keyword(s):

Chemical Composition ◽

Toxic Metals ◽

Road Dust ◽

Airborne Fungi ◽

Potentially Toxic Metals ◽

Opportunistic Fungi ◽

Air Quality Assessment ◽

Relationship Of ◽

First Time ◽

The Relationship

For the first time, a mycological analysis of outdoor urban environment (air, leaves, sealed surfaces) was carried in the cities of subarctic (Murmansk) and temperate (Moscow) climatic zones. The chemical composition of dust deposited on leaves of dominant tree species was taken as an indicator of the air quality. Assessment of the complex impact of factors (climate zone, type of substrate, anthropogenic load) on the quantitative and qualitative parameters of mycobiome was performed. Compared to Moscow, Murmansk was characterized by an increased number and concentrations of pollutants in the deposited dust. The number of culturable airborne fungi in Murmansk was substantially lower than in Moscow. Half of the species belonged to the opportunistic in both cities. Most dangerous opportunistic fungi were absent in the air of recreational zones but present on leaves surface and in road dust in all assessed zones of the cities. Dust chemical composition affected the diversity of fungi species. While the relationship of biological parameters with concentration of potentially toxic metals was generally negative, Cd increased the fraction of opportunistic fungi in road dust. The study revealed an importance of substrate in determining the sensitivity of outdoor mycobiome to pollution and highlighted its biological characteristics sensitive to climate.

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Properties of nickel-based superalloys of equiaxial crystallization

Innovative Materials and Technologies in Metallurgy and Mechanical Engineering ◽

10.15588/1607-6885-2021-2-3 ◽

2021 ◽

pp. 19-23

Author(s):

O. Glotka ◽

V. Olshanetskii

Keyword(s):

Mechanical Properties ◽

Chemical Composition ◽

Regression Models ◽

Computational Prediction ◽

Integrated Approach ◽

Experimental Data Processing ◽

Predictive Regression ◽

Heat Resistant ◽

First Time ◽

Thermodynamic Processes

Purpose. The aim of the work is to obtain predictive regression models, with the help of which, it is possible to adequately calculate the mechanical properties of nickel-based superalloys of equiaxial crystallization, without carrying out preliminary experiments. Research methods. To find regularities and calculate the latest CALPHAD method was chosen, and modeling of thermodynamic processes of phase crystallization was performed. Results. As a result of experimental data processing, the ratio of alloying elements Kg¢ was proposed for the first time, which can be used to assess the mechanical properties, taking into account the complex effect of the main alloy components. The regularities of the influence of the composition on the properties of heat-resistant nickel alloys of equiaxial crystallization are established. The analysis of the received dependences in comparison with practical results is carried out. The relations well correlated with heat resistance, mismatch and strength of alloys are obtained. Scientific novelty. It is shown that for multicomponent nickel systems it is possible with a high probability to predict a mismatch, which significantly affects the strength characteristics of alloys of this class. The regularities of the influence of the chemical composition on the structure and properties of alloys are established. A promising and effective direction in solving the problem of predicting the main characteristics of heat-resistant materials based on nickel is shown Practical value. On the basis of an integrated approach for multicomponent heat-resistant nickel-based alloys, new regression models have been obtained that make it possible to adequately predict the properties of the chemical composition of the alloy, which made it possible to solve the problem of computational prediction of properties from the chemical composition of the alloy. This allows not only to design new nickel-based alloys, but also to optimize the composition of existing brands.

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Rapid Formation of Gas-giant Planets via Collisional Coagulation from Dust Grains to Planetary Cores

The Astrophysical Journal ◽

10.3847/1538-4357/ac289c ◽

2021 ◽

Vol 922 (1) ◽

pp. 16

Author(s):

Hiroshi Kobayashi ◽

Hidekazu Tanaka

Keyword(s):

Protoplanetary Disks ◽

Central Star ◽

Giant Planets ◽

Solar Systems ◽

Evolution Path ◽

Planetary Cores ◽

Rapid Formation ◽

Gas Giant ◽

Planetary Migration ◽

Gas Accretion

Abstract Gas-giant planets, such as Jupiter, Saturn, and massive exoplanets, were formed via the gas accretion onto the solid cores, each with a mass of roughly 10 Earth masses. However, rapid radial migration due to disk–planet interaction prevents the formation of such massive cores via planetesimal accretion. Comparably rapid core growth via pebble accretion requires very massive protoplanetary disks because most pebbles fall into the central star. Although planetesimal formation, planetary migration, and gas-giant core formation have been studied with a lot of effort, the full evolution path from dust to planets is still uncertain. Here we report the result of full simulations for collisional evolution from dust to planets in a whole disk. Dust growth with realistic porosity allows the formation of icy planetesimals in the inner disk (≲10 au), while pebbles formed in the outer disk drift to the inner disk and there grow to planetesimals. The growth of those pebbles to planetesimals suppresses their radial drift and supplies small planetesimals sustainably in the vicinity of cores. This enables rapid formation of sufficiently massive planetary cores within 0.2–0.4 million years, prior to the planetary migration. Our models shows the first gas giants form at 2–7 au in rather common protoplanetary disks, in agreement with the exoplanet and solar systems.

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Ag2S2O8 meets AgSO4: the second example of metal–ligand redox isomerism among inorganic systems

Dalton Transactions ◽

10.1039/c6dt03283d ◽

2016 ◽

Vol 45 (45) ◽

pp. 18202-18207 ◽

Cited By ~ 2

Author(s):

Tomasz E. Gilewski ◽

Piotr J. Leszczyński ◽

Armand Budzianowski ◽

Zoran Mazej ◽

Adam Grzelak ◽

...

Keyword(s):

Chemical Composition ◽

Physicochemical Properties ◽

Inorganic Systems ◽

Redox Isomerism ◽

First Time ◽

Identical Chemical Composition ◽

Metal Ligand

Ag(i)2S2O8 – prepared here for the first time – constitutes a redox isomer of the already known Ag(ii)SO4. These “electromers” have identical chemical composition but they differ in all important physicochemical properties.

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Chemical composition and antifungal activity of essential oils from four Asteraceae plants grown in Egypt

Zeitschrift für Naturforschung C ◽

10.1515/znc-2017-0219 ◽

2018 ◽

Vol 73 (7-8) ◽

pp. 313-318 ◽

Cited By ~ 4

Author(s):

Rose Vanessa Bandeira Reidel ◽

Simona Nardoni ◽

Francesca Mancianti ◽

Claudia Anedda ◽

Abd El-Nasser G. El Gendy ◽

...

Keyword(s):

Chemical Composition ◽

Antifungal Activity ◽

Essential Oil ◽

Essential Oils ◽

Inhibitory Activity ◽

First Time

Abstract The objective of the present paper was the assessment of the chemical composition of the essential oils from four Asteraceae species with a considerable food, medicinal, and agricultural value, collected in Egypt, together with their in vitro inhibitory activity against molds and yeasts. The essential oil of Launaea cornuta flowers was also evaluated for the first time, but because of its very low yield (<0.01%), no antifungal test was performed.

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