Modeling the Atmospheric Contribution to the Interior Characterization of sub-Neptunes and its Effect on Habitability

2020 ◽  
Author(s):  
Jasmine MacKenzie ◽  
Philipp Baumeister ◽  
Mareike Godolt ◽  
Nicola Tosi ◽  
Daria Kubyshkina ◽  
...  
Keyword(s):  
Bulk Composition ◽  
Physical Parameters ◽  
Habitable Zone ◽  
Calculated Density ◽  
Atmospheric Escape ◽  
Dense Cores ◽  
Solar Composition ◽  
Primary Composition ◽  
Low Mass

<p>As the number of confirmed exoplanets has increased, so too has the diversity in their physical parameters, namely their mass and radius. A common practice is to place these planets on a Mass-Radius diagram with various calculated density curves corresponding to some bulk composition. However, these lines don’t necessarily correspond to the structure of the planet found using interior models, particularly for low mass planets with masses less than 20 M<sub>⊕</sub> and 4 R<sub>⊕</sub>, which we call “sub-Neptunes.” Planets in this range can have highly degenerate solutions with no solar system analog, from so-called “ocean worlds” to small dense cores with extended primary composition atmospheres. We have created a model that is able to cover the range of solutions possible for sub-Neptunes, with various levels of complexity for both the interior and atmosphere. This includes both an isothermal and semi-grey atmosphere, along with a high-pressure solar composition envelope when atmospheric pressures exceed approximately 1000 bar. We then apply this model to known sub-Neptunes located in the extended habitable zone of their star using a hydrogen-helium dominated atmosphere. An atmospheric escape model is used to investigate the longevity of the atmosphere and its effect on the overall habitability of the planet.</p>

scholarly journals CHEMICAL AND PHYSICAL CHARACTERIZATION OF COLLAPSING LOW-MASS PRESTELLAR DENSE CORES

2016 ◽  
Vol 822 (1) ◽  
pp. 12 ◽  
Author(s):  
U. Hincelin ◽  
B. Commerçon ◽  
V. Wakelam ◽  
F. Hersant ◽  
S. Guilloteau ◽  
...  
Keyword(s):  
Physical Characterization ◽  
Dense Cores ◽  
Low Mass

scholarly journals Stellar Variabilities: Challenges for the Detection and Characterization of Exoplanets

2012 ◽  
Vol 8 (S293) ◽  
pp. 388-392
Author(s):  
I. Boisse ◽  
X. Dumusque ◽  
N. C. Santos ◽  
M. Oshagh ◽  
X. Bonfils ◽  
...  
Keyword(s):  
Near Infrared ◽  
Parameters Estimation ◽  
Habitable Zone ◽  
M Dwarfs ◽  
Stellar Activity ◽  
Stellar Pulsation ◽  
Low Mass ◽  
Magnetic Cycles ◽  
M Dwarf

AbstractThe photometric and RV techniques, although extremely efficient to detect and characterize planets, are, however, indirect techniques (as well as astrometry). Phenomena such as stellar pulsation, inhomogeneous convection, spots or magnetic cycles can prevent us from finding planets or they might degrade the parameters estimation. We will consider the challenges related to the knowledge of stellar activity for the next decade: detect telluric planets in the habitable zone of their stars (from G to M dwarfs), understand the activity in the low-mass end of M dwarf (on which will focus future near-infrared high-resolution spectrograph like SPIRou or CARMENES), limitation to the process of summing several transit observations (in order to characterize the atmospheric components) due to the variability of stellar activity (from the ground or with Spitzer or JWST), as well as the methods proposed and used to overcome this issue.

scholarly journals Acoustic Characterization of Some Steel Industry Waste Materials

2021 ◽  
Vol 11 (13) ◽  
pp. 5924
Author(s):  
Elisa Levi ◽  
Simona Sgarbi ◽  
Edoardo Alessio Piana
Keyword(s):  
Thermal Characteristic ◽  
Environmental Benefits ◽  
Acoustic Properties ◽  
Physical Parameters ◽  
Industry Waste ◽  
Acoustic Characterization ◽  
Minimization Procedure ◽  
The Difference ◽  
By Products

From a circular economy perspective, the acoustic characterization of steelwork by-products is a topic worth investigating, especially because little or no literature can be found on this subject. The possibility to reuse and add value to a large amount of this kind of waste material can lead to significant economic and environmental benefits. Once properly analyzed and optimized, these by-products can become a valuable alternative to conventional materials for noise control applications. The main acoustic properties of these materials can be investigated by means of a four-microphone impedance tube. Through an inverse technique, it is then possible to derive some non-acoustic properties of interest, useful to physically characterize the structure of the materials. The inverse method adopted in this paper is founded on the Johnson–Champoux–Allard model and uses a standard minimization procedure based on the difference between the sound absorption coefficients obtained experimentally and predicted by the Johnson–Champoux–Allard model. The results obtained are consistent with other literature data for similar materials. The knowledge of the physical parameters retrieved applying this technique (porosity, airflow resistivity, tortuosity, viscous and thermal characteristic length) is fundamental for the acoustic optimization of the porous materials in the case of future applications.

scholarly journals Multiwavelength Modeling the SED of Strongly Interacting Binaries

2011 ◽  
Vol 7 (S282) ◽  
pp. 65-66
Author(s):  
Augustin Skopal
Keyword(s):  
Physical Parameters ◽  
X Rays ◽  
Physical Processes ◽  
Short Contribution ◽  
Composite Spectrum ◽  
X Ray ◽  
Strongly Interacting ◽  
Low Mass ◽  
X Ray Binaries

AbstractThe spectrum of strongly interacting binaries, as for example, high and low mass X-ray binaries, symbiotic (X-ray) binaries and/or classical and recurrent novae, consists of more components of radiation contributing from hard X-rays to radio wavelengths. To understand the basic physical processes responsible for the observed spectrum we have to disentangle the composite spectrum into its individual components, i.e. to determine their physical parameters. In this short contribution I demonstrate the method of modeling the multiwavelength SED on the example of the extragalactic super-soft X-ray source RX J0059.1-7505 (LIN 358).

The habitable zone of Earth-mass planets around 47 UMa: results for land and water worlds

2003 ◽  
Vol 2 (1) ◽  
pp. 35-39 ◽  
Author(s):  
S. Franck ◽  
M. Cuntz ◽  
W. von Bloh ◽  
C. Bounama
Keyword(s):  
Surface Water ◽  
System Approach ◽  
Distinct Type ◽  
Integrated System ◽  
Habitable Zone ◽  
Stable Orbit ◽  
The Earth ◽  
Earth Like Planets ◽  
Very High

In a previous paper, we showed that Earth-type habitable planets around 47 UMa are in principle possible if a distinct set of conditions is warranted. These conditions include that the Earth-type planets have successfully formed and are orbitally stable and, in addition, that the 47 UMa star–planet system is relatively young ([lsim ]6 Gyr). We now extend this study by considering Earth-like planets with different land/ocean coverages. This study is again based on the so-called integrated system approach, which describes the photosynthetic biomass production taking into account a variety of climatological, biogeochemical and geodynamical processes. This approach implies a special characterization of the habitable zone defined for a distinct type of planet. We show that the likelihood of finding a habitable Earth-like planet on a stable orbit around 47 UMa critically depends on the percentage of the planetary land/ocean coverage. The likelihood is significantly increased for planets with a very high percentage of ocean surface (‘water worlds’).

scholarly journals A microvariability study of nearby M dwarfs from the Western Italian Alps: Status update

2010 ◽  
Vol 6 (S276) ◽  
pp. 525-526
Author(s):  
Mario Damasso ◽  
Andrea Bernagozzi ◽  
Enzo Bertolini ◽  
Paolo Calcidese ◽  
Paolo Giacobbe ◽  
...  
Keyword(s):  
Italian Alps ◽  
M Dwarfs ◽  
Red Dwarfs ◽  
Typical Period ◽  
Low Mass ◽  
M Stars ◽  
Rocky Planets ◽  
Long Term Survey

AbstractSmall ground-based telescopes can effectively be used to look for transiting rocky planets around nearby low-mass M stars, as recently demonstrated for example by the MEarth project. Since December 2009 at the Astronomical Observatory of the Autonomous Region of Aosta Valley (OAVdA) we are monitoring photometrically a sample of red dwarfs with accurate parallax measurements. The primary goal of this ‘pilot study’ is the characterization of the photometric microvariability of each target over a typical period of approximately 2 months. This is the preparatory step to long-term survey with an array of identical small telescopes, with kick-off in early 2011. Here we discuss the present status of the study, describing the stellar sample, and presenting the most interesting results obtained so far, including the aggressive data analysis devoted to the characterization of the variability properties of the sample and the search for transit-like signals.

scholarly journals A New Statistical Biomechanics Modeling of Physical and Biochemical Bone Strength Parameters

2000 ◽  
Author(s):  
Alfred B. O. Soboyejo ◽  
Karl E. Nestor
Keyword(s):  
Bone Strength ◽  
Biochemical Parameters ◽  
Broiler Chickens ◽  
Management Practices ◽  
Physical Parameters ◽  
Structural Failure ◽  
Practical Applications ◽  
Good Management ◽  
Biomechanical Parameters

Abstract New multiparameter biomechanics models are developed in this work for the characterization of bone strengths in broiler chickens and turkeys, as functions of the major physical and biochemical parameters, which can contribute to mechanical properties of bone strengths in these birds, under good management practices. Theoretical and experimental methods have been developed in this study to model bone strength as functions of (a) the physical parameters only and (b) the biochemical parameters only, which can affect bone strength. The choice of any particular methodology will depend on the availability of either the physical or biochemical parameters, which can be obtained from experimental data. Possible useful practical applications of the statistical biomechanics principles developed in this technical paper, particularly in the field of bone strength enhancement in turkeys and broiler chickens will be discussed. In view of the problems described, the major objectives of the present study are as follows: (1) To develop new multiparameter biomechanics models for the characterization of bone strengths in turkeys and broiler chickens as functions of the major physical only, or biomechanical parameters only, which can contribute to bone strength in these birds, under conditions of good management of these birds. This study will consider only the compressive buckling as the mode of structural failure in the cellular material of the bone. (2) To highlight briefly the possible practical applications of the statistical biomechanics principles, which will be developed in this study to the genetic improvement of bone strengths in broiler chickens and turkeys.

scholarly journals The cyclone separator application on physicochemical characterization of coconut shell-liquid smoke grade C

2020 ◽  
Vol 3 (2) ◽  
pp. 68-74
Author(s):  
Angky Wahyu Putranto ◽  
Firda Puspaningarum ◽  
Sukardi Sukardi
Keyword(s):  
Total Yield ◽  
Physicochemical Characterization ◽  
Common Method ◽  
Coconut Shell ◽  
Physical Parameters ◽  
Cyclone Separator ◽  
Liquid Smoke ◽  
Direct Condensation

The further processing of coconut shell pyrolysis into liquid smoke has been developed in recent years. However, the common technology by directly condensing the smoke has many impurity compounds which decreases the yield of liquid smoke produced. Hence, in this study the cyclone separator was applied to increase the quality of physicochemical content in coconut shell-liquid smoke (CS-LS) grade C. The physical parameters analyzed were yield, pH, density and color. The chemical parameters was analyzed by GC-MS. The result showed that CS-LS processing with cyclone separator was able to increase the total yield into 3.33%, with better color, pH and density compared to the CS-LS produced using common method (direct condensation). The application of cyclone separator was also able to increase the phenolic compounds (97%), alcoholic compounds (92%), cycloalkene compounds (91%) and also decreased the benzoic acid, carbonyl and ester up to 100% compared with common method for CS-LS grade C production.

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