Effects of Perforation Geometry on Pipe Drainage in Agricultural Lands
Bibliographic record
Abstract
Corrugated high density polyethylene pipes, where groundwater enters through perforations on the pipe wall, are widely used in subsurface drainage systems on agricultural lands. There has been a growing interest in using circular holes in the valleys of corrugated pipes to improve the hydraulic performance of subsurface drains. However, the effects of these circular perforations on the entrance resistance (αe), delivery ratio (Q/Q0), drain spacing, and water table drawdown have not been adequately investigated for corrugated pipes. This study uses a numerical model, calibrated with datasets from sand tank experiments, to simulate the effects of perforation shape, size, and configuration on αe and Q/Q0. The results show that Q/Q0 in corrugated pipes with circular holes is 20% lower than that for plain wall pipes with the same perforation configuration. Perforations shaped as rectangular slots have half the αe of circular holes with the same surface area. It is concluded that the use of rectangular slots is hydraulically more advantageous than circular holes in the valleys of corrugated pipes.
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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 | 0.000 | 0.002 |
| 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 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.001 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 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 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".