{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2015:ZTK7ILLGFQVJ2GSFTLZQI5URB2","merge_version":"pith-open-graph-merge-v1","event_count":2,"valid_event_count":2,"invalid_event_count":0,"equivocation_count":0,"current":{"canonical_record":{"metadata":{"abstract_canon_sha256":"b32cc6aa2c97b4cd0118392e84bfd08f204c7a0e41e8737dfd8f68f558226815","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"physics.flu-dyn","submitted_at":"2015-06-29T22:28:25Z","title_canon_sha256":"3a7281a8893a6eedb056f79656136f9fe2a479c2f655112973821eec6d30afb4"},"schema_version":"1.0","source":{"id":"1506.08889","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1506.08889","created_at":"2026-05-18T01:27:23Z"},{"alias_kind":"arxiv_version","alias_value":"1506.08889v1","created_at":"2026-05-18T01:27:23Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1506.08889","created_at":"2026-05-18T01:27:23Z"},{"alias_kind":"pith_short_12","alias_value":"ZTK7ILLGFQVJ","created_at":"2026-05-18T12:29:52Z"},{"alias_kind":"pith_short_16","alias_value":"ZTK7ILLGFQVJ2GSF","created_at":"2026-05-18T12:29:52Z"},{"alias_kind":"pith_short_8","alias_value":"ZTK7ILLG","created_at":"2026-05-18T12:29:52Z"}],"graph_snapshots":[{"event_id":"sha256:5de373bc7fb409ea306d54ec79005a2356faafb83fe5372169a64ea9dd165467","target":"graph","created_at":"2026-05-18T01:27:23Z","signer":{"key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signer_id":"pith.science","signer_type":"pith_registry"},"payload":{"graph_snapshot":{"author_claims":{"count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","strong_count":0},"builder_version":"pith-number-builder-2026-05-17-v1","claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"paper":{"abstract_excerpt":"Non-intrusive quantitative fluid density measurements methods are essential in stratified flow experiments. Digital imaging leads to synthetic Schlieren methods in which the variations of the index of refraction are reconstructed computationally. In this study, an important extension to one of these methods, called Background Oriented Schlieren (BOS), is proposed. The extension enables an accurate reconstruction of the density field in stratified liquid experiments. Typically, the experiments are performed by the light source, background pattern, and the camera positioned on the opposite sides","authors_text":"Alex Liberzon, Lilly Verso","cross_cats":[],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"physics.flu-dyn","submitted_at":"2015-06-29T22:28:25Z","title":"Background Oriented Schlieren in a Density Stratified Fluid"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1506.08889","kind":"arxiv","version":1},"verdict":{"created_at":null,"id":null,"model_set":{},"one_line_summary":"","pipeline_version":null,"pith_extraction_headline":"","strongest_claim":"","weakest_assumption":""}},"verdict_id":null}}],"author_attestations":[],"timestamp_anchors":[],"storage_attestations":[],"citation_signatures":[],"replication_records":[],"corrections":[],"mirror_hints":[],"record_created":{"event_id":"sha256:ec978c0a52bcee8d827a164e14d5e5dd234876a3bde9e9ef4c93ca301eb6155a","target":"record","created_at":"2026-05-18T01:27:23Z","signer":{"key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signer_id":"pith.science","signer_type":"pith_registry"},"payload":{"attestation_state":"computed","canonical_record":{"metadata":{"abstract_canon_sha256":"b32cc6aa2c97b4cd0118392e84bfd08f204c7a0e41e8737dfd8f68f558226815","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"physics.flu-dyn","submitted_at":"2015-06-29T22:28:25Z","title_canon_sha256":"3a7281a8893a6eedb056f79656136f9fe2a479c2f655112973821eec6d30afb4"},"schema_version":"1.0","source":{"id":"1506.08889","kind":"arxiv","version":1}},"canonical_sha256":"ccd5f42d662c2a9d1a459af30476910e897e4f9b01baaf1a47f5c968ab13e44e","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"ccd5f42d662c2a9d1a459af30476910e897e4f9b01baaf1a47f5c968ab13e44e","first_computed_at":"2026-05-18T01:27:23.315784Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T01:27:23.315784Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"pGWpAerIJ8eTKfBMmibgB6RKzcoisKtH6Bwcz3+8axwqv0VqwzzuGmXrCTOmKrkaLDJ3w8InMhagcQ2lm8YNBg==","signature_status":"signed_v1","signed_at":"2026-05-18T01:27:23.316218Z","signed_message":"canonical_sha256_bytes"},"source_id":"1506.08889","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:ec978c0a52bcee8d827a164e14d5e5dd234876a3bde9e9ef4c93ca301eb6155a","sha256:5de373bc7fb409ea306d54ec79005a2356faafb83fe5372169a64ea9dd165467"],"state_sha256":"1ac24db9a455237074421e89e26fa23d308b7ed66c3e9fdd0f61932338fd8f48"}