scholarly journals Analytic solutions for Asay foil trajectories with implications for ejecta source models and mass measurements

2021 ◽  
Vol 130 (12) ◽  
pp. 124504
Author(s):  
I. L. Tregillis ◽  
Aaron Koskelo ◽  
Alan K. Harrison
Keyword(s):  
Analytic Solutions ◽  
Mass Measurements ◽  
Source Models

scholarly journals Problems of welding in shipbuilding - an analytic-numerical assessment of the thermal cycle in HAZ with three dimensional heat source models in agreement with modelling rules

2010 ◽  
Vol 17 (3) ◽  
pp. 45-52
Author(s):  
Eugeniusz Ranatowski
Keyword(s):  
Temperature Distribution ◽  
Heat Source ◽  
Thermal Cycle ◽  
Computer Calculation ◽  
Three Dimensional ◽  
Analytic Solutions ◽  
Previous Part ◽  
Numerical Assessment ◽  
Source Models

Problems of welding in shipbuilding - an analytic-numerical assessment of the thermal cycle in HAZ with three dimensional heat source models in agreement with modelling rules This part is continuation of PART II. Analytic solutions for the temperature distribution in HAZ - presented in the previous part of this article are transformed for computer calculation with used Mathcad programme. There are established algorithms in moving and stationary systems for thermal cycle calculating. Finally, a few analytical examples with use of C-I-N and D-E models are demonstrated.

scholarly journals Analytic Solutions as a Tool for Verification and Validation of a Multiphysics Model

2019 ◽  
Vol 4 (4) ◽  
Author(s):  
I. L. Tregillis ◽  
Aaron Koskelo
Keyword(s):  
National Laboratory ◽  
Source Model ◽  
Analytic Solutions ◽  
Time Dependent ◽  
Specific Class ◽  
Mass Measurements ◽  
Los Alamos ◽  
Los Alamos National Laboratory ◽  
Fluid Instability ◽  
Experimental Parameters

Abstract Computational physicists are commonly faced with the task of resolving discrepancies between the predictions of a complex, integrated multiphysics numerical simulation, and corresponding experimental datasets. Such efforts commonly require a slow iterative procedure. However, a different approach is available in casesx where the multiphysics system of interest admits closed-form analytic solutions. In this situation, the ambiguity is conveniently broken into separate consideration of theory–simulation comparisons (issues of verification) and theory–data comparisons (issues of validation). We demonstrate this methodology via application to the specific example of a fluid-instability-based ejecta source model under development at Los Alamos National Laboratory and implemented in flag, a Los Alamos continuum mechanics code. The formalism is conducted in the forward sense (i.e., from source to measurement) and enables us to compute, purely analytically, time-dependent piezoelectric ejecta mass measurements for a specific class of explosively driven metal coupon experiments. We incorporate published measurement uncertainties on relevant experimental parameters to estimate a time-dependent uncertainty on these analytic predictions. This motivates the introduction of a “compatibility score” metric, our primary tool for quantitative analysis of the RMI + SSVD model. Finally, we derive a modification to the model, based on boundary condition considerations, that substantially improves its predictions.

Analytic Solutions As a Tool for Verification and Validation of a Multiphysics Model

2019 ◽  
Author(s):  
I. L. Tregillis ◽  
Aaron Koskelo
Keyword(s):  
National Laboratory ◽  
Source Model ◽  
Analytic Solutions ◽  
Specific Class ◽  
Alamos National Laboratory ◽  
Mass Measurements ◽  
Los Alamos ◽  
Los Alamos National Laboratory ◽  
Fluid Instability ◽  
Experimental Parameters

Abstract Computational physicists are commonly faced with the task of resolving discrepancies between the predictions of a complex, integrated multi-physics numerical simulation and corresponding experimental datasets. Such efforts commonly require a slow iterative procedure. However, a different approach is available in cases where the multi-physics system of interest admits closed-form analytic solutions. In this situation, the ambiguity is conveniently broken into separate consideration of theory-simulation comparisons (issues of verification) and theory-data comparisons (issues of validation). We demonstrate this methodology via application to the specific example of a fluid-instability based ejecta source model (“RMI+SSVD”) under development at Los Alamos National Laboratory and implemented in FLAG, a Los Alamos continuum mechanics code. The formalism is conducted in the forward sense (i.e., from source to measurement) and enables us to compute, purely analytically, piezoelectric ejecta mass measurements for a specific class of explosively driven metal coupon experiments. We incorporate published measurement uncertainties on relevant experimental parameters to estimate a time-dependent uncertainty on these analytic predictions. This motivates the introduction of a “compatibility score” metric, our primary tool for quantitative analysis of the RMI+SSVD model.

Radial mass analysis of unstained STEM images of molluscan hemocyanins

1990 ◽  
Vol 48 (3) ◽  
pp. 810-811
Author(s):  
M.G. Hamilton ◽  
T.T. Herskovits ◽  
J.S. Wall
Keyword(s):  
Image Analysis ◽  
Hollow Cylinder ◽  
Electron Micrographs ◽  
Side View ◽  
Mass Analysis ◽  
Mass Measurements ◽  
Electron Microscopic ◽  
Transmission Electron ◽  
Transmission Electron Microscopic ◽  
Microscopic Studies

The hemocyanins of molluscs are aggregates of a cylindrical decameric subparticle that assembles into di-, tri-, tetra-, penta-, and larger multi-decameric particles with masses that are multiples of the 4.4 Md decamer. Electron micrographs of these hemocyanins typically show the particles with two profiles: circular representing the cylinder viewed from the end and rectangular representing the side-view of the hollow cylinder.The model proposed by Mellema and Klug from image analysis of a didecameric hemocyanin with the two decamers facing one another with collar (closed) ends outward fits the appearance of side-views of the negatively-stained cylinders. These authors also suggested that there might be caps at the ends. In one of a series of transmission electron microscopic studies of molluscan hemocyanins, Siezen and Van Bruggen supported the Mellema-Klug model, but stated that they had never observed a cap component. With STEM we have tested the end cap hypothesis by direct mass measurements across the end-views of unstained particles.

The Role of Computer Modeling in Electrocardiography

1990 ◽  
Vol 29 (04) ◽  
pp. 282-288 ◽  
Author(s):  
A. van Oosterom
Keyword(s):  
Electrical Activity ◽  
Computer Modeling ◽  
Body Surface ◽  
Electrical Current ◽  
The Body ◽  
Volume Conductor ◽  
Current Generator ◽  
Cardiac Electrical Activity ◽  
Source Models

AbstractThis paper introduces some levels at which the computer has been incorporated in the research into the basis of electrocardiography. The emphasis lies on the modeling of the heart as an electrical current generator and of the properties of the body as a volume conductor, both playing a major role in the shaping of the electrocardiographic waveforms recorded at the body surface. It is claimed that the Forward-Problem of electrocardiography is no longer a problem. Several source models of cardiac electrical activity are considered, one of which can be directly interpreted in terms of the underlying electrophysiology (the depolarization sequence of the ventricles). The importance of using tailored rather than textbook geometry in inverse procedures is stressed.

Analytic Solutions to the Closed Bomb

1988 ◽  
Author(s):  
Frederick W. Robbins ◽  
Franz R. Lynn
Keyword(s):  
Analytic Solutions
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