Experimental study on air pressure variation in a horizontal pipe of single-stack drainage system
Bibliographic record
Abstract
Abstract The water trap seal under the sanitary appliances is the primary defense against the ingress of foul gases and odors. However, research on air pressure variation in a horizontal pipe of a single-stack drainage system is very limited. Thus a physical model study was conducted to investigate the air pressure variation in a horizontal pipe. Four parameters were studied that affect the pressure variation; that is, water flow rate, inlet height, ventilation condition and outlet condition. When the top of the vertical drainage stack and the outlet were fully open to the atmosphere, the flow in the horizontal pipe changed from free surface flow to slug flow at certain times. The mean values and magnitudes of pressure fluctuation at measuring points on the horizontal pipe increased with Qw but decreased along the horizontal pipe. The inlet height had relatively small influence on the pressure variation. Three ventilation conditions; that is, top fully open, half open and sealed, were tested, and a choking flow was formed in the vertical drainage stack and the pressure in the horizontal pipe decreased under the top sealed condition. Three outlet conditions; that is, outlet fully open, half submerged and fully submerged, were tested. The pressure in the horizontal pipe increased significantly under the outlet fully-submerged condition, which should be avoided in the actual operation by careful designing.
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 | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| 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".