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Record W2053099186 · doi:10.1002/mame.200400392

Mathematical Model and Parameter Estimation for Gas‐Phase Ethylene/Hexene Copolymerization With Metallocene Catalyst

2005· article· en· W2053099186 on OpenAlex

Why this work is in the frame

A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.

affAt least one author lists a Canadian institution in the pinned OpenAlex snapshot.

Bibliographic record

VenueMacromolecular Materials and Engineering · 2005
Typearticle
Languageen
FieldChemical Engineering
TopicCatalysis and Oxidation Reactions
Canadian institutionsDuPont (Canada)Queen's University
Fundersnot available
KeywordsMaterials scienceHexeneEthyleneCopolymerBranching (polymer chemistry)1-HexeneExperimental dataThermodynamicsEstimation theoryPhase (matter)CatalysisAlgorithmStatisticsMathematicsChemistryOrganic chemistryPhysicsComposite material

Abstract

fetched live from OpenAlex

Abstract Summary: Models were developed to simulate gas‐phase ethylene/hexene copolymerization using a silica‐supported (BuCp) 2 ZrCl 2 catalyst in a semi‐batch laboratory reactor. The models are able to predict ethylene consumption rate, gas composition drift during the experimental runs, as well as number‐and weight‐average molecular weight, and short‐chain branching levels, and triad sequence distributions of copolymer removed from the reactor at the end of each run. A single‐site model was first developed, but it failed to accurately predict the molecular weight data and its distribution. Sequentially, a two‐site model was built to improve model predictions. Parameter estimability analysis was performed to guide model simplification and to ensure that the parameter estimation problem would be well conditioned. After model simplification, which reduced the number of unknown parameters from 55 to 37, the parameters were estimated and good fitting of most experimental data was obtained. The simplified two‐site model was validated using the data from four extra experimental runs, which were not employed in the parameter estimation process. Most of the model predictions fall within the 95% confidence intervals of the experimental data. Model validation of hexene concentration. (The lines are model predictions and the solid diamonds with error bars are experimental data.) magnified image Model validation of hexene concentration. (The lines are model predictions and the solid diamonds with error bars are experimental data.)

Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.

Full frame distilled prediction

Teacher imitation

Not calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.

metaresearch head score (Codex)0.000
metaresearch head score (Gemma)0.000
Version: codex-gemma-dda1882f352aValidation status: machine_predicted_unvalidated
Candidate categoriesnone
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Bench or experimental · Consensus signal: none
GenreCandidate signal: Empirical · Consensus signal: Empirical
Teacher disagreement score0.448
Threshold uncertainty score0.647

Codex and Gemma teacher scores by category

CategoryCodexGemma
Metaresearch0.0000.000
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0000.000
Bibliometrics0.0000.000
Science and technology studies0.0000.000
Scholarly communication0.0000.000
Open science0.0000.000
Research integrity0.0000.000
Insufficient payload (model declined to judge)0.0000.000

Machine scores (provisional)

The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.

Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.

Opus teacher head0.008
GPT teacher head0.230
Teacher spread0.222 · how far apart the two teachers sit on this one work
Validation statusscore_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it