{
  "abstract": "We present antasena, an open-source Python library for calculations that underlie diving with nitrox, oxygen-nitrogen mixtures richer in oxygen than air. It computes depth limits, equivalent depths, inert-gas uptake, no-decompression limits, staged decompression schedules, central-nervous-system and pulmonary oxygen exposure, real-gas cylinder contents, and partial-pressure blending, and its command-line and desktop interfaces display the derivation of every result with the user’s inputs substituted. Each working equation is derived from the three-dimensional momentum balance of a fluid at rest, the advection-diffusion equation for a dissolved gas in perfused tissue, and the Helmholtz free energy of a gas mixture, with every reducing assumption stated. Because a dive plan is a sequence of segments of fixed gas and linearly varying depth, tissue tensions, oxygen doses, and gas consumption admit closed forms without time stepping. An independent re-implementation reproduces the closed-form tensions to within relative differences of 5 × 10^{−13} against fourth-order Runge-Kutta integration and 9 × 10^{−16} against 60-digit arithmetic, whereas the textbook form loses digits to cancellation on short segments. The analysis indicates that the classical equivalent air depth is shallower than its alveolar-consistent counterpart by 6 to 15 cm, that the textbook blending formula yields fills about 0.3 percentage points richer than intended for a 32% mixture at 200 bar, and that ideal-gas planning overstates the usable gas of an air cylinder filled to 232 bar by about 5%. All 79 independent checks pass. The library serves teaching and planning and does not predict individual physiological risk.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": null,
  "author_total": 7,
  "authors": [
    {
      "name": "Sandy Hardian Susanto Herho"
    },
    {
      "name": "Faruq Khadami"
    },
    {
      "name": "Faizal Ade Rahmahuddin Abdullah"
    },
    {
      "name": "Iwan Pramesti Anwar"
    },
    {
      "name": "Karina Aprilia Sujatmiko"
    },
    {
      "name": "Alfita Puspa Handayani"
    },
    {
      "name": "Dasapta Erwin Irawan"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/8p6zqhyy8tdna.bib",
  "cited_by": 0,
  "doi": "10.31223/x5822b",
  "fulltext_url": null,
  "id": "8p6zqhyy8tdna",
  "issns": [],
  "landing_url": "https://eartharxiv.org/repository/view/15743/",
  "language": null,
  "licence": "CC-BY-4.0",
  "licence_label": "CC BY 4.0",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/legalcode",
  "metadata_licence": null,
  "native_subjects": [
    [
      "bepress",
      "Bühlmann ZHL-16C model"
    ],
    [
      "bepress",
      "Dynamic Systems"
    ],
    [
      "bepress",
      "Fluid Dynamics"
    ],
    [
      "bepress",
      "Numerical Analysis and Computation"
    ],
    [
      "bepress",
      "Oceanography"
    ],
    [
      "bepress",
      "Schreiner equation"
    ],
    [
      "bepress",
      "enriched air nitrox"
    ],
    [
      "bepress",
      "multiparameter equation of state"
    ],
    [
      "bepress",
      "perfusion-limited gas exchange"
    ],
    [
      "openalex",
      "2740|Cardiovascular and Diving-Related Complications"
    ]
  ],
  "openalex": "W7223455092",
  "pdf_url": "https://eartharxiv.org/repository/object/15743/download/27270/",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-24",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/8p6zqhyy8tdna.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:17:52Z",
      "native_id": "15743",
      "source": "eartharxiv",
      "url": "https://eartharxiv.org/repository/view/15743/"
    }
  ],
  "subjects": [
    {
      "field": "earth",
      "origin": "bepress:Oceanography",
      "subfield": "oceanography"
    },
    {
      "field": "mathematics",
      "origin": "bepress:Numerical Analysis and Computation",
      "subfield": "numerical-analysis"
    },
    {
      "field": "physics",
      "origin": "bepress:Fluid Dynamics",
      "subfield": "fluid-dynamics"
    }
  ],
  "title": "antasena: A Python Library for Nitrox Diving Calculations",
  "title_text": "antasena: A Python Library for Nitrox Diving Calculations",
  "type": "preprint",
  "updated_at": "2026-10-30T12:17:52Z",
  "url": "https://research.draconitic.com/paper/8p6zqhyy8tdna",
  "venue": "EarthArXiv",
  "versions": []
}