scholarly journals Constraining the circumbinary disc tilt in the KH 15D system

2021 ◽  
Vol 503 (2) ◽  
pp. 1599-1614
Author(s):  
Michael Poon ◽  
J J Zanazzi ◽  
Wei Zhu
Keyword(s):  
Physical Properties ◽  
Density Profile ◽  
Surface Density ◽  
Outer Edge ◽  
Photometric Data ◽  
Photometric Variability ◽  
The Past ◽  
Consistent Model ◽  
Self Consistent ◽  
The Difference

ABSTRACT KH 15D is a system that consists of a young, eccentric binary, and a circumbinary disc that obscures the binary as the disc precesses. We develop a self-consistent model that provides a reasonable fit to the photometric variability that was observed in the KH 15D system over the past 60 yr. Our model suggests that the circumbinary disc has an inner edge rin ≲ 1 au, an outer edge rout ∼ a few au, and that the disc is misaligned relative to the stellar binary by ∼5–16°, with the inner edge more inclined than the outer edge. The difference between the inclinations (warp) and longitude of ascending nodes (twist) at the inner and outer edges of the disc are of order ∼10 and ∼15°, respectively. We also provide constraints on other properties of the disc, such as the precession period and surface density profile. Our work demonstrates the power of photometric data in constraining the physical properties of planet-forming circumbinary discs.

Transneptunian Space

2021 ◽  
Vol 59 (1) ◽  
pp. 203-246
Author(s):  
Brett Gladman ◽  
Kathryn Volk
Keyword(s):  
Physical Properties ◽  
Kuiper Belt ◽  
Semimajor Axis ◽  
Protoplanetary Disks ◽  
Outer Edge ◽  
Observational Constraints ◽  
The Past ◽  
Current State ◽  
Dynamical Features

We provide a nonspecialist overview of the current state of understanding of the structure and origin of our Solar System's transneptunian region (often called the Kuiper Belt), highlighting perspectives on planetesimal formation, planet migration, and the contextual relationship with protoplanetary disks. We review the dynamical features of the transneptunian populations and their associated differences in physical properties. We describe aspects of our knowledge that have advanced in the past two decades and then move on to current issues of research interest (which thus still have unclear resolution). ▪  The current transneptunian population consists of both implanted and primordial objects. ▪  The primordial (aka cold) population is a largely unaltered remnant of the population that formed in situ. ▪  The reason for the primordial cold population's current outer edge is unexplained. ▪  The large semimajor-axis population now dynamically detached from Neptune is critical for understanding the Solar System's history. ▪  Observational constraints on the number and orbits of distant objects remain poor.

Effect of Residual Stresses on Mechanical Properties of Duplex Stainless Steel Studied by Diffraction and Self-Consistent Modelling

2006 ◽  
Vol 524-525 ◽  
pp. 185-190 ◽  
Author(s):  
Rim Dakhlaoui ◽  
Chedly Braham ◽  
Andrzej Baczmanski ◽  
Sebastian Wroński ◽  
Krzysztof Wierzbanowski ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Residual Stresses ◽  
Duplex Stainless Steel ◽  
Initial Stresses ◽  
Internal Stresses ◽  
Shear Stresses ◽  
Model Calculations ◽  
Consistent Model ◽  
Self Consistent ◽  
The Difference

The aim of this work is to study the influence of residual stresses on the properties of textured duplex stainless steel (DSS). The properties of both phases in DSS were studied using Xray diffraction whilst external load was applied “in situ” to the sample. The interpretation of experimental data is based on the diffraction elastic constants calculated by the self-consistent model taking into account the anisotropy of the studied material. Carrying out measurements in both compression and tension by using neutron diffraction, important differences in the evolution of lattice strains were noticed. An elastoplastic model is used to predict the evolution of the internal stresses during loading and to identify critical resolved shear stresses and strain hardening parameters of the material. The influence of the initial residual stresses on the yield stresses of the phases is considered. The difference between tensile and compressive behaviour of the steel is explained when the initial stresses (measured in the as received non-loaded sample by diffraction methods) are taken into account in model calculations. The yield stresses in each phase of the studied steel have been experimentally determined and successfully compared with the results of the elastoplastic self-consistent model.

THEORY AND SELF-CONSISTENT MODEL OF DUST-DRIVEN WINDS

2002 ◽  
Vol 5 ◽  
pp. 65-65
Author(s):  
S. Liberatore ◽  
J.-P.J. Lafon ◽  
N. Berruyer
Keyword(s):  
Consistent Model ◽  
Self Consistent

Smart Estimation Ver-H.1.0

2018 ◽  
Author(s):  
Sigit Haryadi
Keyword(s):  
Sample Size ◽  
Confidence Level ◽  
Time Span ◽  
Regression Equation ◽  
Weight Factor ◽  
The Past ◽  
Level Of Confidence ◽  
The Future ◽  
Future Value ◽  
The Difference

We cannot be sure exactly what will happen, we can only estimate by using a particular method, where each method must have the formula to create a regression equation and a formula to calculate the confidence level of the estimated value. This paper conveys a method of estimating the future values, in which the formula for creating a regression equation is based on the assumption that the future value will depend on the difference of the past values divided by a weight factor which corresponding to the time span to the present, and the formula for calculating the level of confidence is to use "the Haryadi Index". The advantage of this method is to remain accurate regardless of the sample size and may ignore the past value that is considered irrelevant.

scholarly journals Stellar Flares: Observations and Theory

1989 ◽  
Vol 104 (2) ◽  
pp. 49-52
Author(s):  
Suzanne L. Hawley
Keyword(s):  
Scaling Law ◽  
Dynamic Scaling ◽  
X Ray ◽  
Temperature Distributions ◽  
Photometric And Spectroscopic Observations ◽  
Stellar Flares ◽  
Consistent Model ◽  
Self Consistent ◽  
Flare Model ◽  
Large Flare

AbstractPhotometric and spectroscopic observations of a very large flare on AD Leo are presented. A self consistent model of a flare corona, transition region and chromosphere is developed; in particular the chromospheric temperature distributions resulting from X-ray and EUV irradiation by coronae of various temperatures are determined. The predicted line fluxes in Hγ are compared to the observed line fluxes to find the coronal temperature as a function of time during the flare. This run of temperature with time is then compared with the predictions of an independent theoretical flare model based on a dynamic scaling law (see paper by Fisher and Hawley, these proceedings).

scholarly journals A Self‐Consistent Model for Sorption and Transport in Polyimide‐Derived Carbon Molecular Sieve Gas Separation Membranes

2020 ◽  
Vol 132 (46) ◽  
pp. 20523-20527
Author(s):  
Oishi Sanyal ◽  
Samuel S. Hays ◽  
Nicholas E. León ◽  
Yoseph A. Guta ◽  
Arun K. Itta ◽  
...  
Keyword(s):  
Gas Separation ◽  
Molecular Sieve ◽  
Carbon Molecular Sieve ◽  
Separation Membranes ◽  
Gas Separation Membranes ◽  
Consistent Model ◽  
Self Consistent

scholarly journals The Rules for the Lattice Rotation Accompanying Slip as Derived From a Self-Consistent Model

1999 ◽  
Vol 31 (4) ◽  
pp. 217-230 ◽  
Author(s):  
R. A. Lebensohn ◽  
T. Leffers
Keyword(s):  
Solid Mechanics ◽  
Grain Shape ◽  
Rolling Plane ◽  
Lattice Rotation ◽  
Consistent Model ◽  
Plane Strain Deformation ◽  
Self Consistent ◽  
The One ◽  
Equiaxed Grains ◽  
Very High

The rules for the lattice rotation during rolling (plane strain) deformation of fcc polycrystals are studied with a viscoplastic self-consistent model. Very high values of the ratesensitivity exponent are used in order to establish Sachs-type conditions with large local deviations from the macroscopic strain. The lattice rotation depends on the grain shape. For equiaxed grains the lattice rotation follows the MA rule, which is the one normally used in solid mechanics. For elongated and flat grains the lattice rotation follows a different rule, the PSA rule. In the standard version the model performs a transition from MA to PSA with increasing strain. There is avery clear difference between the textures resulting from the two different rules. MA leads to a copper-type texture, and PSA leads to a brass-type texture.

scholarly journals Self-consistent model for ambipolar tunnelling in quantum-well systems

1995 ◽  
Vol 10 (5) ◽  
pp. 577-585 ◽  
Author(s):  
C Presilla ◽  
V Emiliani ◽  
A Frova
Keyword(s):  
Quantum Well ◽  
Consistent Model ◽  
Self Consistent

scholarly journals The Burden of the Nondiversifiable Risk of Entrepreneurship

2010 ◽  
Vol 100 (3) ◽  
pp. 1163-1194 ◽  
Author(s):  
Robert E Hall ◽  
Susan E Woodward
Keyword(s):  
Relative Risk ◽  
Risk Aversion ◽  
Venture Capital ◽  
Dynamic Program ◽  
Certainty Equivalent ◽  
Important Class ◽  
Relative Risk Aversion ◽  
The Past ◽  
Equity Value ◽  
The Difference

Entrepreneurship is risky. We study the risk facing a well-documented and important class of entrepreneurs, those backed by venture capital. Using a dynamic program, we calculate the certainty-equivalent of the difference between the cash rewards that entrepreneurs actually received over the past 20 years and the cash that entrepreneurs would have received from a risk-free salaried job. The payoff to a venture-backed entrepreneur comprises a below-market salary and a share of the equity value of the company when it goes public or is acquired. We find that the typical venture-backed entrepreneur received an average of $5.8 million in exit cash. Almost three-quarters of entrepreneurs receive nothing at exit and a few receive over a billion dollars. Because of the extreme dispersion of payoffs, an entrepreneur with a coefficient of relative risk aversion of two places a certainty equivalent value only slightly greater than zero on the distribution of outcomes she faces at the time of her company's launch. (JEL G24, G32, L26, M13)

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