{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,31]],"date-time":"2026-03-31T18:39:47Z","timestamp":1774982387113,"version":"3.50.1"},"reference-count":32,"publisher":"MDPI AG","issue":"1","license":[{"start":{"date-parts":[[2019,2,16]],"date-time":"2019-02-16T00:00:00Z","timestamp":1550275200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Actuators"],"abstract":"<jats:p>This paper presents a case study and a model to predict maintenance interventions based on condition monitoring of diesel engine oil in urban buses by accompanying the evolution of its degradation. Many times, under normal functioning conditions, the properties of the lubricants, based on the intervals that manufacturers recommend for its change, are within normal and safety conditions. Then, if the lubricants\u2019 oil condition is adequately accompanied, until reaching the degradation limits, the intervals of oil replacement can be enlarged, meaning that the buses\u2019 availability increases, as well as their corresponding production time. Based on this assumption, a mathematical model to follow and to manage the oil condition is presented, in order to predict the next intervention with the maximum time between them, which means the maximum availability.<\/jats:p>","DOI":"10.3390\/act8010014","type":"journal-article","created":{"date-parts":[[2019,2,17]],"date-time":"2019-02-17T22:11:50Z","timestamp":1550441510000},"page":"14","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":55,"title":["Condition Monitoring with Prediction Based on Diesel Engine Oil Analysis: A Case Study for Urban Buses"],"prefix":"10.3390","volume":"8","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-1682-5950","authenticated-orcid":false,"given":"Hugo","family":"Raposo","sequence":"first","affiliation":[{"name":"Centre for Mechanical Engineering, Materials and Processes (CEMMPRE), University of Coimbra, 3030-788 Coimbra, Portugal"},{"name":"Instituto Superior de Engenharia de Coimbra, Polytechnic of Coimbra, 3030-199 Coimbra, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9694-8079","authenticated-orcid":false,"given":"Jos\u00e9 Torres","family":"Farinha","sequence":"additional","affiliation":[{"name":"Centre for Mechanical Engineering, Materials and Processes (CEMMPRE), University of Coimbra, 3030-788 Coimbra, Portugal"},{"name":"Instituto Superior de Engenharia de Coimbra, Polytechnic of Coimbra, 3030-199 Coimbra, Portugal"}]},{"given":"In\u00e1cio","family":"Fonseca","sequence":"additional","affiliation":[{"name":"Centre for Mechanical Engineering, Materials and Processes (CEMMPRE), University of Coimbra, 3030-788 Coimbra, Portugal"},{"name":"Instituto Superior de Engenharia de Coimbra, Polytechnic of Coimbra, 3030-199 Coimbra, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4667-8864","authenticated-orcid":false,"given":"L. Andrade","family":"Ferreira","sequence":"additional","affiliation":[{"name":"Faculty of Engineering, University of Porto, 4200-465 Porto, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2019,2,16]]},"reference":[{"key":"ref_1","unstructured":"Cabral, J.S. (2006). Organiza\u00e7\u00e3o e Gest\u00e3o da Manuten\u00e7\u00e3o, Lidel\u2014Edi\u00e7\u00f5es T\u00e9cnicas Lda. [6th ed.]."},{"key":"ref_2","unstructured":"Assis, R. (1997). Manuten\u00e7\u00e3o Centrada na Fiabilidade, Lidel\u2014Edi\u00e7\u00f5es T\u00e9cnicas Lda."},{"key":"ref_3","unstructured":"Pinto, C.V. (2002). Organiza\u00e7\u00e3o e Gest\u00e3o da Manuten\u00e7\u00e3o, Monitor\u2014Projecto e Edi\u00e7\u00f5es, Lda. [2nd ed.]."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"1425","DOI":"10.1080\/002075400188933","article-title":"A Model to Determine the Optimal Critical Leveland the Monitoring in Condition Based Maintenance","volume":"38","author":"Wang","year":"2000","journal-title":"Int. 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