Experimental and numerical fitting of model parameters versus the gas pressure using six phase radiative Lee model in AECS PF-1, 2 and INTI PF for nitrogen, argon, and neon gases

2020 ◽  
Vol 60 (7) ◽  
pp. e201900119
Author(s):  
Sh. Al-Hawat ◽  
M. Akel ◽  
S. H. Saw ◽  
S. Lee
Keyword(s):  
Gas Pressure ◽  
Model Parameters ◽  
Lee Model ◽  
Numerical Fitting

Application of Mathematical Methods to Determine the Field Parameters Related to Diffusion of Methane Gas in a Bulli Seam

1986 ◽  
Vol 10 (4) ◽  
pp. 185-190 ◽  
Author(s):  
A. Basu ◽  
R. D. Lama
Keyword(s):  
Gas Flow ◽  
Darcy’S Law ◽  
Darcy's Law ◽  
Gas Pressure ◽  
Model Parameters ◽  
Fick’S Law ◽  
Mathematical Methods ◽  
Fick's Law ◽  
Diffusion Parameters ◽  
Field Diffusion

The paper describes the application of a mathematical model to describe gas drainage in coal seams. The mechanism of gas flow from coal is not very clear at present. It can either follow Darcy’s law or Fick’s law of diffusion. In the opinion of the authors, a the earlier stages where the gas pressure is high, Darcy’s law applies [8]. At later stages when gas pressure is stabilised, Fick’s law of diffusion is applicable. In this study, therefore, Fick’s law has been applied. Experimental techniques for measuring the system model parameters such as in situ gas pressure and Langmuir’s constants are described. The solutions have been applied in a field experiment to determine field diffusion parameters.

scholarly journals Application of Lee Model Curve on Fitting of Discharge Current Curve of Plasma Focus Device

2021 ◽  
Vol 1 (1) ◽  
pp. 47-56
Author(s):  
Prakash Gautam
Keyword(s):  
Plasma Focus ◽  
Numerical Experiments ◽  
Electrical Circuit ◽  
Model Parameters ◽  
Lee Model Code ◽  
Lee Model ◽  
Model Code ◽  
Current Curve ◽  
Computer Based ◽  
Current Trace

A dense plasma focus is a table top machine producing a short-lived extremely popular plasma and cause fusion. Lee Model Code is a computer-based visual basic simulation package, which was successfully utilized in the plasma focus devices. The dynamics of plasma focus discharge is quite complicated, so to review and simplify the complication Lee Model couples electrical circuit with the plasma focus dynamics, radiation and therefore the thermodynamics. This enables us to simulate all of the gross focus properties. In this paper the numerical experiments are carried out to compute the current trace as a function of time for plasma focus (PF) device NX2. Results obtained by the numerical experiments are compared with the published laboratory measured data. This current fitting is completed to get the model parameters.

What happened with the comet 71P/Clark?

1999 ◽  
Vol 173 ◽  
pp. 259-264
Author(s):  
S. Szutowicz
Keyword(s):  
Active Regions ◽  
Discrete Source ◽  
Spin Axis ◽  
Model Parameters ◽  
The Sun ◽  
Surface Distribution ◽  
Axis Orientation ◽  
Numerical Fitting ◽  
Nongravitational Effects

AbstractDiscovered in 1973, 71P/Clark had made only five revolutions around the Sun. The motion of the comet has been subjected to a constant small deceleration between 1973 and 1989 and then a dramatic jump in the nongravitational perturbations occured. To explain the discontinuity in the comet's nongravitational effects a change in the surface distribution of active areas and a nucleus orientation was considered. The model of discrete source of out gassing was employed in the orbital calculations. From numerical fitting of the model parameters to positional observations the spin-axis orientation, localizations and outgassing areas of two active regions have been derived and the orbit successfully improved. The nucleus radius was estimated as equal to 0.76 km.

Model Parameters Versus Gas Pressure in Two Different Plasma Focus Devices Operated in Argon and Neon

2011 ◽  
Vol 31 (1) ◽  
pp. 13-20 ◽  
Author(s):  
Sh. Al-Hawat ◽  
M. Akel ◽  
S. Lee ◽  
S. H. Saw
Keyword(s):  
Plasma Focus ◽  
Gas Pressure ◽  
Model Parameters

Instrumental and Ideological Union Commitment: Longitudinal Assessment of Construct Validity

2001 ◽  
Vol 17 (2) ◽  
pp. 98-111 ◽  
Author(s):  
Anders Sjöberg ◽  
Magnus Sverke
Keyword(s):  
Construct Validity ◽  
Temporal Stability ◽  
Strong Support ◽  
Internal Consistency Reliability ◽  
Measurement Model ◽  
Two Dimensions ◽  
Model Parameters ◽  
Longitudinal Assessment ◽  
Union Commitment ◽  
Union Participation

Summary: Previous research has identified instrumentality and ideology as important aspects of member attachment to labor unions. The present study evaluated the construct validity of a scale designed to reflect the two dimensions of instrumental and ideological union commitment using a sample of 1170 Swedish blue-collar union members. Longitudinal data were used to test seven propositions referring to the dimensionality, internal consistency reliability, and temporal stability of the scale as well as postulated group differences in union participation to which the scale should be sensitive. Support for the hypothesized factor structure of the scale and for adequate reliabilities of the dimensions was obtained and was also replicated 18 months later. Tests for equality of measurement model parameters and test-retest correlations indicated support for the temporal stability of the scale. In addition, the results were consistent with most of the predicted differences between groups characterized by different patterns of change/stability in union participation status. The study provides strong support for the construct validity of the scale and indicates that it can be used in future theory testing on instrumental and ideological union commitment.

Representation of bolted joints in a structure using finite element modelling and model updating

2020 ◽  
Vol 14 (3) ◽  
pp. 7141-7151 ◽  
Author(s):  
R. Omar ◽  
M. N. Abdul Rani ◽  
M. A. Yunus
Keyword(s):  
Finite Element ◽  
Dynamic Behaviour ◽  
Model Updating ◽  
Complex Structure ◽  
Bolted Joints ◽  
Model Parameters ◽  
Fe Model ◽  
Bolted Joint ◽  
Fe Modelling ◽  
Joint Structure

Efficient and accurate finite element (FE) modelling of bolted joints is essential for increasing confidence in the investigation of structural vibrations. However, modelling of bolted joints for the investigation is often found to be very challenging. This paper proposes an appropriate FE representation of bolted joints for the prediction of the dynamic behaviour of a bolted joint structure. Two different FE models of the bolted joint structure with two different FE element connectors, which are CBEAM and CBUSH, representing the bolted joints are developed. Modal updating is used to correlate the two FE models with the experimental model. The dynamic behaviour of the two FE models is compared with experimental modal analysis to evaluate and determine the most appropriate FE model of the bolted joint structure. The comparison reveals that the CBUSH element connectors based FE model has a greater capability in representing the bolted joints with 86 percent accuracy and greater efficiency in updating the model parameters. The proposed modelling technique will be useful in the modelling of a complex structure with a large number of bolted joints.

A Note on Confidence Intervals and Model Specification

Marketing ZFP ◽  
2019 ◽  
Vol 41 (4) ◽  
pp. 33-42
Author(s):  
Thomas Otter
Keyword(s):  
Confidence Intervals ◽  
Generalized Linear Model ◽  
Statistical Information ◽  
Regression Coefficients ◽  
Model Specification ◽  
Model Parameters ◽  
Exploratory Research ◽  
Empirical Calibration ◽  
Credible Intervals ◽  
Model Structures

Empirical research in marketing often is, at least in parts, exploratory. The goal of exploratory research, by definition, extends beyond the empirical calibration of parameters in well established models and includes the empirical assessment of different model specifications. In this context researchers often rely on the statistical information about parameters in a given model to learn about likely model structures. An example is the search for the 'true' set of covariates in a regression model based on confidence intervals of regression coefficients. The purpose of this paper is to illustrate and compare different measures of statistical information about model parameters in the context of a generalized linear model: classical confidence intervals, bootstrapped confidence intervals, and Bayesian posterior credible intervals from a model that adapts its dimensionality as a function of the information in the data. I find that inference from the adaptive Bayesian model dominates that based on classical and bootstrapped intervals in a given model.

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