{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,12]],"date-time":"2025-10-12T02:36:05Z","timestamp":1760236565192,"version":"build-2065373602"},"reference-count":35,"publisher":"MDPI AG","issue":"23","license":[{"start":{"date-parts":[[2021,11,30]],"date-time":"2021-11-30T00:00:00Z","timestamp":1638230400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100000923","name":"Australian research council","doi-asserted-by":"publisher","award":["(ARC) LP170100108"],"award-info":[{"award-number":["(ARC) LP170100108"]}],"id":[{"id":"10.13039\/501100000923","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>Large sheets of high-density polyethene geomembrane are used as floating covers on some of the wastewater treatment lagoons at the Melbourne Water Corporation\u2019s Western Treatment Plant. These covers provide an airtight seal for the anaerobic digestion of sewage and allow for harvesting the methane-rich biogas, which is then used to generate electricity. There is a potential for scum to develop under the covers during the anaerobic digestion of the raw sewage by microorganisms. Due to the nature of the operating environment of the lagoons and the vast size (450 m \u00d7 170 m) of these covers, a safe non-contact method to monitor the development and movement of the scum is preferred. This paper explores the potential of using a new thermographic approach to identify and monitor the scum under the covers. The approach exploits naturally occurring variations in solar intensity as a trigger for generating a transient thermal response that is then fitted to an exponential decay law to determine a cooling constant. This approach is investigated experimentally using a laboratory-scale test rig. A finite element (FE) model is constructed and shown to reliably predict the experimentally observed thermal transients and cooling constants. This FE model is then set up to simulate progressive scum accumulation with time, using a specified scumberg geometry and a stepwise change in thermal properties. The results indicate a detectable change in the cooling constant at different locations on the cover, thereby providing a quantitative basis for characterising the scum accumulation beneath the cover. The practical application and limitations of these results are briefly discussed.<\/jats:p>","DOI":"10.3390\/rs13234857","type":"journal-article","created":{"date-parts":[[2021,12,1]],"date-time":"2021-12-01T01:45:02Z","timestamp":1638323102000},"page":"4857","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":3,"title":["Thermographic Monitoring of Scum Accumulation beneath Floating Covers"],"prefix":"10.3390","volume":"13","author":[{"given":"Yue","family":"Ma","sequence":"first","affiliation":[{"name":"Department of Mechanical & Aerospace Engineering, Monash University, Clayton, VIC 3800, Australia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Francis","family":"Rose","sequence":"additional","affiliation":[{"name":"Defence Science and Technology Group, 506 Lorimer St., Port Melbourne, VIC 3207, Australia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3227-7648","authenticated-orcid":false,"given":"Leslie","family":"Wong","sequence":"additional","affiliation":[{"name":"Department of Mechanical & Aerospace Engineering, Monash University, Clayton, VIC 3800, Australia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0991-4293","authenticated-orcid":false,"given":"Benjamin Steven","family":"Vien","sequence":"additional","affiliation":[{"name":"Department of Mechanical & Aerospace Engineering, Monash University, Clayton, VIC 3800, Australia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4775-2165","authenticated-orcid":false,"given":"Thomas","family":"Kuen","sequence":"additional","affiliation":[{"name":"Melbourne Water Corporation, 990 La Trobe Street, Docklands, VIC 3008, Australia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Nik","family":"Rajic","sequence":"additional","affiliation":[{"name":"Defence Science and Technology Group, 506 Lorimer St., Port Melbourne, VIC 3207, Australia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jayantha","family":"Kodikara","sequence":"additional","affiliation":[{"name":"Department of Civil Engineering, Monash University, Clayton, VIC 3168, Australia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4359-2814","authenticated-orcid":false,"given":"Wing Kong","family":"Chiu","sequence":"additional","affiliation":[{"name":"Department of Mechanical & Aerospace Engineering, Monash University, Clayton, VIC 3800, Australia"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2021,11,30]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"930","DOI":"10.1061\/(ASCE)GT.1943-5606.0000302","article-title":"Antioxidant Depletion from a High Density Polyethylene Geomembrane under Simulated Landfill Conditions","volume":"136","author":"Rowe","year":"2010","journal-title":"J. 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