Prediction of the McAllister model parameters from pure component properties for liquid binary n-alkane systems

1991 ◽  
Vol 30 (7) ◽  
pp. 1666-1669 ◽  
Author(s):  
Abdul Fattah A. Asfour ◽  
Elizabeth F. Copper ◽  
Jiangning Wu ◽  
Rouchdy R. Zahran
Keyword(s):  
Pure Component ◽  
Model Parameters

scholarly journals LEVENBERG-MARQUARDT METHOD APPLIED TO THE DETERMINATION OF VAPOR-LIQUID EQUILIBRIUM MODEL PARAMETERS

2014 ◽  
Vol 44 (4) ◽  
pp. 319-324
Author(s):  
J.A. F. OLIVEIRA ◽  
M.M. L. DUARTE ◽  
E. L. FOLETTO ◽  
O. CHIAVONE-FILHO
Keyword(s):  
Structural Parameters ◽  
Pure Component ◽  
Estimation Methods ◽  
Model Parameters ◽  
Arbitrary Matrix ◽  
Marquardt Algorithm ◽  
Levenberg Marquardt ◽  
Equilibrium Data ◽  
Parameter Estimation Methods ◽  
Vaporliquid Equilibrium

 In order to correlate and optimize experimental data either from the laboratory or industry, one needs a robust method of data regression. Among the non-linear parameter estimation methods it may be pointed out of Levenberg, which applies the conversion of an arbitrary matrix into a positive definite one. Later, Marquardt applied the same procedure, calculating  parameter in an iterative form. The Levenberg-Marquardt algorithm is described and two routine for correlating vaporliquid equilibrium data for pure component and mixtures, based on this efficient method, have been applied. The routines have been written with an interface very accessible for both users and programmers, using Python language. The flexibility of the developed programs for introducing the desired details is quite interesting for both process simulators and modeling properties. Furthermore, for mixtures with electrolytes, it was obtained a coherent and compatible relation for the structural parameters of the salt species, with the aid of the method and the graphical interface designed.

scholarly journals A Robust High-dimensional Data Reduction Method

2010 ◽  
Vol 9 (1) ◽  
pp. 55-60 ◽  
Author(s):  
Longcun Jin ◽  
Wanggen Wan ◽  
Yongliang Wu ◽  
Bin Cui ◽  
Xiaoqing Yu ◽  
...  
Keyword(s):  
Data Reduction ◽  
Reduction Method ◽  
Hyperspectral Image ◽  
High Dimensional Data ◽  
Cognitive Model ◽  
Pure Component ◽  
High Dimensional ◽  
Model Parameters ◽  
Reduction Algorithm ◽  
Data Reduction Method

In this paper, we propose a robust high-dimensional data reduction method. The model assumes that the pixel reflec-tance results from linear combinations of pure component spectra contaminated by an additive noise. The abundance parameters appearing in this model satisfy positivity and additive constraints. These constraints are naturally expressed in a Bayesian literature by using appropriate abundance prior distributions. The posterior distributions of the unknown model parameters are then derived. The proposed algorithm consists of Bayesian inductive cognition part and hierarchical reduction algorithm model part. The pro-posed reduction algorithm based on Bayesian inductive cognitive model is used to decide which dimensions are advantageous and to output the recommended dimensions of the hyperspectral image. The algorithm can be interpreted as a robust reduction inference method for a Bayesian inductive cognitive model. Experimental results on high-dimensional data demonstrate useful properties of the proposed reduction algorithm.

Factual data banks and their application to the synthesis and design of chemical processes and the development and testing of thermophysical property estimation methods

2009 ◽  
Vol 81 (10) ◽  
pp. 1745-1768 ◽  
Author(s):  
Jürgen Rarey ◽  
Jürgen Gmehling
Keyword(s):  
Thermophysical Property ◽  
Process Simulation ◽  
Data Bank ◽  
Pure Component ◽  
Estimation Methods ◽  
Model Parameters ◽  
Environmental Models ◽  
Property Estimation ◽  
Factual Data ◽  
Data Banks

Factual data banks nowadays play an important role as a source for thermophysical property data for use in chemical process simulation, environmental models, and many other computer-based applications. In this work, the historical developments leading to modern factual data banks, the differences compared to other more bibliographically oriented data banks, and their most important applications and future potential will be discussed by using the example of the Dortmund Data Bank (DDB). As the development of the different predictive models for mixtures is covered in a separate publication, this paper focuses on pure-component property estimation, regression of model parameters, test and verification of model parameters prior to process simulation, and advanced topics in process synthesis such as selection of entrainers and data-mining applications.

Electron Microscopic Analysis of Myonecrosis Induced by a Pure Component Isolated From Rattlesnake Venom

1976 ◽  
Vol 34 ◽  
pp. 292-293
Author(s):  
Charlotte L. Ownby ◽  
David Cameron ◽  
Anthony T. Tu
Keyword(s):  
Gel Filtration ◽  
Microscopic Analysis ◽  
The United States ◽  
Exchange Chromatography ◽  
Pure Component ◽  
Electron Microscopic Level ◽  
Electron Microscopic ◽  
Mouse Muscle ◽  
Major Health Problem ◽  
Rattlesnake Venom

In the United States the major health problem resulting from snakebite poisoning is local tissue damage, i.e. hemorrhage and myonecrosis. Since commercial antivenin does not usually prevent such damage to tissue, a more effective treatment of snakebite-induced myonecrosis is needed. To aid in the development of such a treatment the pathogenesis of myonecrosis induced by a pure component of rattlesnake venom was studied at the electron microscopic level.The pure component, a small (4,300 mol. wt.), basic (isoelectric point of 9.6) protein, was isolated from crude prairie rattlesnake (Crotalus viridis viridis) venom by gel filtration (Sephadex G-50) followed by cation exchange chromatography (Sephadex C-25), and shown to be pure by electrophoresis. Selection of the myotoxic component was based on light microscopic observations of injected mouse muscle.

Fractionation of polymethylene chains: An electron crystallographic investigation

1986 ◽  
Vol 44 ◽  
pp. 794-795
Author(s):  
Douglas L. Dorset
Keyword(s):  
Cross Section ◽  
Binary Systems ◽  
Linear Chain ◽  
Pure Component ◽  
Organic Substrates ◽  
Crystallographic Investigation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Molecular Sizes ◽  
The Stability

A variety of linear chain materials exist as polydisperse systems which are difficultly purified. The stability of continuous binary solid solutions assume that the Gibbs free energy of the solution is lower than that of either crystal component, a condition which includes such factors as relative molecular sizes and shapes and perhaps the symmetry of the pure component crystal structures.Although extensive studies of n-alkane miscibility have been carried out via powder X-ray diffraction of bulk samples we have begun to examine binary systems as single crystals, taking advantage of the well-known enhanced scattering cross section of matter for electrons and also the favorable projection of a paraffin crystal structure posited by epitaxial crystallization of such samples on organic substrates such as benzoic acid.

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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