Integrated model predictions on the impact of substrate damage on gas dynamics during ITER burning-plasma operations

2021 ◽  
Author(s):  
Ane Lasa ◽  
Sophie Blondel ◽  
David E Bernholdt ◽  
John M Canik ◽  
M R Cianciosa ◽  
...  
Keyword(s):  
Gas Dynamics ◽  
Integrated Model ◽  
Burning Plasma ◽  
Model Predictions ◽  
The Impact

Impact of random soil properties on stress–strain response

2004 ◽  
Vol 41 (2) ◽  
pp. 351-355 ◽  
Author(s):  
Dieter Stolle ◽  
Peijun Guo ◽  
Gabriel Sedran
Keyword(s):  
Soil Properties ◽  
Constitutive Modelling ◽  
Soil Parameters ◽  
Strain Response ◽  
Constitutive Behaviour ◽  
Stress Strain ◽  
Deterministic Analysis ◽  
Model Predictions ◽  
Random Variability ◽  
The Impact

This paper analyzes the impact of natural random variation of soil properties on the constitutive modelling of geomaterial behaviour. A theoretical framework for accommodating variation in soil properties is presented. The framework is then used to examine the consequence of parameter variability on stress–strain relations. An important observation is that average soil parameters from a series of tests on small specimens, in which density of the specimens varies randomly, do not necessarily reflect the average constitutive behaviour of soil. Model predictions are shown to be consistent with the experimental data.Key words: random variability, deterministic analysis, soil parameters, constitutive model.

The Effect of Explosion in a Tunnel Tube on its Damage

2018 ◽  
Vol 774 ◽  
pp. 265-270
Author(s):  
Petr P. Prochazka ◽  
Martin J. Válek
Keyword(s):  
Gas Dynamics ◽  
Solid Phase ◽  
Fiber Reinforced Concrete ◽  
Reinforced Concrete Structure ◽  
Air Velocity ◽  
Shell Elements ◽  
Final Volume ◽  
Flat Shell ◽  
The Impact ◽  
Geometric Compatibility

The aim of the work is to study the impact of an explosion in a tube on its damage. The theory of Landau-Liftschitz gas dynamics and the damage criterion by the Hoek-Brown in the structure are applied. If the charge is placed centrically in the tube, it is fairly easy to predict both the locations and damage levels. Therefore, the paper is oriented to the case where the charge is placed eccentrically. Air movement is described by the solution of non-linear Euler’s equations by final volume element method, while the response of the fiber reinforced concrete structure of the tube to impact waves is described by the time dependent 20-nodes flat shell elements. In order to ensure the geometric compatibility along the interface between the two media (structure, air), gas dynamics in the air is described by block elements, while the shell is approximated by the finite element. In this way, the problem solved is divided into a description of the air velocity and pressure and the velocity and stress in the solid phase, separately; interaction of the effects caused by the explosion initiated inside of the tube and its impact on the solid phase is concentrated along the interface between these two media. The calculation focuses on the early stages of interaction development when most likely damage is assumed.

scholarly journals Exploring the associations between transcript levels and fluxes in constraint-based models of metabolism

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Neeraj Sinha ◽  
Evert M. van Schothorst ◽  
Guido J. E. J. Hooiveld ◽  
Jaap Keijer ◽  
Vitor A. P. Martins dos Santos ◽  
...  
Keyword(s):  
Metabolic Flux ◽  
Transcript Levels ◽  
Proportionality Constant ◽  
Model Predictions ◽  
Physiological Information ◽  
Highly Expressed Genes ◽  
Transcriptomics Data ◽  
Genome Scale ◽  
The Impact ◽  
Constraint Based Models

Abstract Background Several computational methods have been developed that integrate transcriptomics data with genome-scale metabolic reconstructions to increase accuracy of inferences of intracellular metabolic flux distributions. Even though existing methods use transcript abundances as a proxy for enzyme activity, each method uses a different hypothesis and assumptions. Most methods implicitly assume a proportionality between transcript levels and flux through the corresponding function, although these proportionality constant(s) are often not explicitly mentioned nor discussed in any of the published methods. E-Flux is one such method and, in this algorithm, flux bounds are related to expression data, so that reactions associated with highly expressed genes are allowed to carry higher flux values. Results Here, we extended E-Flux and systematically evaluated the impact of an assumed proportionality constant on model predictions. We used data from published experiments with Escherichia coli and Saccharomyces cerevisiae and we compared the predictions of the algorithm to measured extracellular and intracellular fluxes. Conclusion We showed that detailed modelling using a proportionality constant can greatly impact the outcome of the analysis. This increases accuracy and allows for extraction of better physiological information.

scholarly journals ENHANCED MASS LOSS RATES IN RED SUPERGIANTS AND THEIR IMPACT ON THE CIRCUMSTELLAR MEDIUM

2019 ◽  
Vol 55 (2) ◽  
pp. 161-175
Author(s):  
L. Hernández-Cervantes ◽  
B. Pérez-Rendón ◽  
A. Santillán ◽  
G. García-Segura ◽  
C. Rodríguez-Ibarra
Keyword(s):  
Mass Loss ◽  
Stellar Evolution ◽  
Gas Dynamics ◽  
Numerical Experiments ◽  
Evolutionary Models ◽  
Solar Composition ◽  
Red Supergiants ◽  
The Impact ◽  
Circumstellar Medium ◽  
Loss Rates

In this work, we present models of massive stars between 15 and 23 M⊙ , with enhanced mass loss rates during the red supergiant phase. Our aim is to explore the impact of extreme red supergiant mass-loss on stellar evolution and on their circumstellar medium. We computed a set of numerical experiments, on the evolution of single stars with initial masses of 15, 18, 20 and, 23 M⊙ , and solar composition (Z = 0.014), using the numerical stellar code BEC. From these evolutionary models, we obtained time-dependent stellar wind parameters, that were used explicitly as inner boundary conditions in the hydrodynamical code ZEUS-3D, which simulates the gas dynamics in the circumstellar medium (CSM), thus coupling the stellar evolution to the dynamics of the CSM. We found that stars with extreme mass loss in the RSG phase behave as a larger mass stars.

scholarly journals The Impact Assessment of Campus Buildings Based on a Life Cycle Assessment–Life Cycle Cost Integrated Model

2019 ◽  
Vol 12 (1) ◽  
pp. 294 ◽  
Author(s):  
Zhuyuan Xue ◽  
Hongbo Liu ◽  
Qinxiao Zhang ◽  
Jingxin Wang ◽  
Jilin Fan ◽  
...  
Keyword(s):  
Life Cycle Assessment ◽  
Life Cycle ◽  
Environmental Impacts ◽  
Life Cycle Cost ◽  
Electric Energy ◽  
Integrated Model ◽  
Economic Costs ◽  
Analytic Hierarchy ◽  
The Sustainable Development ◽  
The Impact

The development of higher education has led to an increasing demand for campus buildings. To promote the sustainable development of campus buildings, this paper combines social willingness-to-pay (WTP) with the analytic hierarchy process (AHP) based on the characteristics of Chinese campus buildings to establish a life cycle assessment–life cycle cost (LCA–LCC) integrated model. Based on this model, this paper analyses the teaching building at a university in North China. The results show that the environmental impacts and economic costs are largest in the operation phase of the life cycle, mainly because of the use of electric energy. The environmental impacts and economic costs during the construction phase mainly come from the building material production process (BMPP); in this process, steel is the main source. Throughout the life cycle, abiotic depletion-fossil fuel potential (ADP fossil) and global warming potential (GWP) are the most prominent indexes. Further analysis shows that these two indexes should be the emphases of similar building assessments in the near future. Finally, this study offers suggestions for the proposed buildings and existing buildings based on the prominent problems found in the case study, with the aim to provide reference for the design, construction, and operation management of similar buildings.

The Student Experience of Video-Enhanced Learning, Assessment, and Feedback

2020 ◽  
pp. 20-40
Author(s):  
James McDowell
Keyword(s):  
Student Experience ◽  
Integrated Model ◽  
Learning Assessment ◽  
Self Awareness ◽  
Structured Interviews ◽  
Methodological Triangulation ◽  
Direct Interpretation ◽  
Interviewing Techniques ◽  
The Impact ◽  
Enhanced Learning

Evaluating the impact on the student experience of the integrated model of video-enhanced learning, assessment, and feedback discussed in the previous chapter, qualitative data collection employed anonymous online questionnaires, semi-structured interviews, and dialogic interviewing techniques, drawing on summative results data to inform methodological triangulation of the findings. Data analysis combined thematic analysis, constant comparison, and direct interpretation within a grounded theory framework. Illustrative cases present the findings as thick descriptions of the influence of video-based interventions on the experience of six purposively and representatively selected participants. The chapter concludes that an integrated model of asynchronous video-enhanced learning, assessment, and feedback can promote increased reflexivity, enhance learner autonomy, and encourage meta-cognitive self-awareness, while affording greater inclusivity for students affected by dyslexia or Asperger's Syndrome.

Removal and fate of Cryptosporidium in dissolved air drinking water treatment plants

2001 ◽  
Vol 43 (8) ◽  
pp. 51-57 ◽  
Author(s):  
J. K. Edzwald ◽  
J. E. Tobiason ◽  
H. Dunn ◽  
G. Kaminski ◽  
P. Galant
Keyword(s):  
Natural Organic Matter ◽  
Drinking Water Treatment ◽  
Spring Water ◽  
Water Production ◽  
Dissolved Air Flotation ◽  
Model Predictions ◽  
Particle Counts ◽  
Recycle Rate ◽  
The Impact ◽  
Dissolved Air

In the first part of the paper, data from pilot plant studies are used to evaluate Cryptosporidium removal by dissolved air flotation (DAF) clarification and dual media filters under challenge conditions. Oocyst removals were investigated for design detention times and hydraulic loadings for winter and spring seasons. Coagulation was optimized for turbidity and removal of natural organic matter. DAF performance was better for spring water temperatures achieving 2.5 ± 0.3 log removal of oocysts compared to 1.7 ± 0.3 log removal in the winter. Cumulative log removal across DAF and filtration exceeded 5.4, and was not affected by water temperature. Low turbidities and particle counts are indicators of good treatment and good removals of Cryptosporidium. The second part of the paper uses a mathematical model to predict the fate of Cryptosporidium through a DAF plant and the impact of filter backwash recycle on oocyst build-up in the plant influent. Model predictions show that the fate of Cryptosporidium and the build-up of oocysts in the plant influent depend on: DAF performance, the percent of filtered water production used for backwashing, and the percent of filter backwash recycle flow. A DAF plant with 2.5% filtered water production for backwashing and that achieves 1.6 log removal or greater of oocysts by DAF clarification will not have a build-up of oocysts in the plant influent regardless of the recycle rate. This is because the oocysts are concentrated in the DAF floated sludge and not within granular filters.

Analysis of Madejski Splat-Quench Solidification Model With Modified Initial Conditions

2004 ◽  
Vol 126 (3) ◽  
pp. 485-489 ◽  
Author(s):  
D. Sivakumar ◽  
H. Nishiyama
Keyword(s):  
Present Model ◽  
Initial Conditions ◽  
Substrate Surface ◽  
Solid Substrate ◽  
Droplet Radius ◽  
Time Interval ◽  
Solidification Model ◽  
Numerical Predictions ◽  
Model Predictions ◽  
The Impact

The initial conditions of Madejski’s splat-quench solidification model for the impact of molten droplets on a solid substrate surface are modified by eliminating the adjustable parameter “ε” used in the estimation of initial spreading droplet radius. In the present model, the initial conditions are estimated after a definite time interval from the start of impact. Numerical predictions obtained from an improved Madejski model with different ε and the corresponding experimental measurements published in the literature are used for the comparison of the present model predictions. The improvements noted from the model predictions are reported.

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