{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,5]],"date-time":"2026-03-05T03:50:06Z","timestamp":1772682606578,"version":"3.50.1"},"reference-count":31,"publisher":"MDPI AG","issue":"12","license":[{"start":{"date-parts":[[2020,6,20]],"date-time":"2020-06-20T00:00:00Z","timestamp":1592611200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>In solar thermal plants, the use of molten salt as a heat transfer fluid is an advantageous alternative, although it has some disadvantages such as the formation of salt plugs in the pipes due to possible stratification of the salt or its solidification. The aim of this study was to implement an electromagnetic acoustic transducer (EMAT) not only capable of identifying the position of the plug, but also of determining whether the plug blocks the entire conductive surface or, on the contrary, is partial, allowing the fluid to pass through a smaller section. The proposed transducer is intended to be minimally invasive, allowing it to be used in the same way as a temperature probe. To do so, it creates torsional waves in the pipe, which are then used for a combination of measurements: pulse-echo and attenuation of the acoustic waves. Two materials with different densities (silicone and cement) were used in the tests carried out, which made it possible to check that for a given size of blockage, it is possible to identify the type of material from which it is formed.<\/jats:p>","DOI":"10.3390\/s20123490","type":"journal-article","created":{"date-parts":[[2020,6,23]],"date-time":"2020-06-23T09:05:33Z","timestamp":1592903133000},"page":"3490","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":5,"title":["Estimation of Blockage Position, Geometry, and Solidity in Molten Salt Pipelines"],"prefix":"10.3390","volume":"20","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-6510-1422","authenticated-orcid":false,"given":"Alberto M.","family":"Pern\u00eda","sequence":"first","affiliation":[{"name":"Department of Electrical Engineering, University of Oviedo, 33204 Gij\u00f3n, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3250-1371","authenticated-orcid":false,"given":"H\u00e9ctor Andr\u00e9s","family":"Mayor","sequence":"additional","affiliation":[{"name":"Department of Electrical Engineering, University of Oviedo, 33204 Gij\u00f3n, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9059-5519","authenticated-orcid":false,"given":"Miguel J.","family":"Prieto","sequence":"additional","affiliation":[{"name":"Department of Electrical Engineering, University of Oviedo, 33204 Gij\u00f3n, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6073-2826","authenticated-orcid":false,"given":"Pedro J.","family":"Villegas","sequence":"additional","affiliation":[{"name":"Department of Electrical Engineering, University of Oviedo, 33204 Gij\u00f3n, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Juan \u00c1.","family":"Mart\u00ednez","sequence":"additional","affiliation":[{"name":"Department of Electrical Engineering, University of Oviedo, 33204 Gij\u00f3n, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Juan A.","family":"Mart\u00edn-Ramos","sequence":"additional","affiliation":[{"name":"Department of Electrical Engineering, University of Oviedo, 33204 Gij\u00f3n, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2020,6,20]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"608","DOI":"10.1016\/j.rser.2018.04.102","article-title":"Solar thermal power plants\u2014A review of configurations and performance comparison","volume":"92","author":"Behar","year":"2018","journal-title":"Renew. 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