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Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).
The specimen surfaces tested in lubricated conditions using LAN-46 machine oil (Ra = 0.63 μm, h = 12 mm, w = 14 mm, orientation 90°) at different magnifications: (a) ×970 and (b) ×530.