Aerosol discharge velocity and particle size characteristics of a low powered e-cigarette by phase Doppler anemometer
Bibliographic record
Abstract
Electronic cigarettes, also known as e-cigarettes, may have become a tool to improve smoking cessation due to their ability to provide nicotine at a selected rate. However, caution still needs to be taken when using e-cigarettes due to the presence of addictive nicotine and harmful substances, produced from the heating process of aerosolization. The aerosol particle size distribution (PSD) and associated velocities generated by e-cigarettes have significant influence on aerosol deposition in different regions of human respiratory tracts. Due to the importance regarding inhalation risk reduction, deeper understanding of particle velocity and size characteristics of e-cigarettes demands thorough investigation. However, comprehensive study on PSD and velocity of e-cigarettes with a standard testing condition at relatively low heating powers (e.g., power < 10 W), which are beneficial considering a reduced emission of toxic chemicals, is still lacking. On another note, while different dilution methods can mislead the comparison and assessment of device performances, data about particle size and velocity of undiluted e-cigarette aerosols are scarce. The present study aims to measure particle number count and size distribution of undiluted aerosols of a latest fourth-generation e-cigarette at a low power of 2.5 W. Temporal and spatial growth of particle velocity and size distribution of an aerosol flow are examined using a phase Doppler anemometry (PDA) technique. To the authors’ best knowledge, application of PDA in e-cigarette aerosol measurement is rarely reported. Velocity measurement revealed a time duration of optimum heating operation for the atomizer. The centerline mean velocity decay of the aerosol discharge suggested a limited mixing and entrainment characteristic compared to a typical air/water jet due to the presence of aerosol particles in the flow region. The particle interactions and collisions in the aerosol flow field possibly increased the centerline turbulence intensity level compared to a canonical free laminar jet. The particle size measurement depicted a continuous increase in particle diameters during a puff period due to potential volatility of e-liquid, and vigorous aerosolization and particle coagulation processes. Spatial evolution of arithmetic mean diameter, count median diameter, and geometric standard deviation of aerosol discharge along the flow centerline and transverse direction are reported. Based on these results, moisture absorption of hygroscopic aerosols, particle evaporation, and particle size re-distribution phenomena are explained as the flow propagated downstream. This present study makes an important contribution to the advancement and optimization of aerosol-generating devices. Also, this study has potential implications in PSD simulation and validation of aerosol dosimetry models.
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.
How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot 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.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
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.
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 teacher head, 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".