High-accuracy effective density measurements of sodium methanesulfonate and aminium chloride nanoparticles using a particulate calibration standard
Bibliographic record
Abstract
Methanesulfonate and aminium salts are commonly found in ambient nanoparticles and are often used as calibration standards. However, the effective densities of the particles generated from these standards are required if they are to be used to calibrate aerosol mass spectrometers or to estimate hygroscopic growth factors from electrodynamic balance experiments. A centrifugal particle mass analyzer and scanning mobility particle sizer were used in tandem (CPMA-SMPS) to measure the effective density of five salts. The effective densities were determined to be: sodium methanesulfonate, 1474 ± 13 kg m−3; methylammonium chloride, 1236 ± 29 kg m−3, monoethanolamine hydrochloride, 1136 ± 26 kg m−3; 1,4-diaminobutane dihydrochloride, 1135 ± 33 kg m−3; and NaCl was found to have a size-dependent effective density due to its non-spherical shape. It is also shown how Santovac® vacuum pump oil can be used to accurately calibrate the CPMA-SMPS system for particles less than 100 nm in diameter, which is a size range that has been problematic for calibration techniques relying on polystyrene latex spheres.Copyright © 2023 American Association for Aerosol Research
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.003 | 0.003 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.002 | 0.001 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.002 | 0.001 |
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.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".