CINXE.COM

<!DOCTYPE html><html lang="en-US"><head><title>Just a moment...</title><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"><meta http-equiv="X-UA-Compatible" content="IE=Edge"><meta name="robots" content="noindex,nofollow"><meta name="viewport" content="width=device-width,initial-scale=1"><style>*{box-sizing:border-box;margin:0;padding:0}html{line-height:1.15;-webkit-text-size-adjust:100%;color:#313131;font-family:system-ui,-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Helvetica Neue,Arial,Noto Sans,sans-serif,Apple Color Emoji,Segoe UI Emoji,Segoe UI Symbol,Noto Color Emoji}body{display:flex;flex-direction:column;height:100vh;min-height:100vh}.main-content{margin:8rem auto;max-width:60rem;padding-left:1.5rem}@media (width <= 720px){.main-content{margin-top:4rem}}.h2{font-size:1.5rem;font-weight:500;line-height:2.25rem}@media (width <= 720px){.h2{font-size:1.25rem;line-height:1.5rem}}#challenge-error-text{background-image:url(data:image/svg+xml;base64,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);background-repeat:no-repeat;background-size:contain;padding-left:34px}@media (prefers-color-scheme:dark){body{background-color:#222;color:#d9d9d9}}</style><meta http-equiv="refresh" content="120"></head><body class="no-js"><div class="main-wrapper" role="main"><div class="main-content"><noscript><div class="h2"><span id="challenge-error-text">Enable JavaScript and cookies to continue</span></div></noscript></div></div><script>(function(){window._cf_chl_opt={cvId: '3',cZone: "publications.waset.org",cType: 'non-interactive',cRay: '91349f7a1bf45fc0',cH: 'I5gJqNSl1f59Rn7TLdX3GFYhbPoGvMmzbekQenWFs9I-1739783202-1.2.1.1-aJC2GsgKyUbOamXN2DWVhQU7CxglfCHL6N1nTiDRJxvtFlkYRgBxBEKMG6yNaOtn',cUPMDTk: "\/abstracts\/search?q=oil-free&__cf_chl_tk=nUHZgoo1XlNI34_5BD1_x1qhdnlAdK8Sdg9icXdnBVY-1739783202-1.0.1.1-BHM7_zjsA6Vx1NU1QaUoflBAVgELZJ4sKIuY16B2pJM",cFPWv: 'b',cITimeS: '1739783202',cTTimeMs: '1000',cMTimeMs: '120000',cTplC: 0,cTplV: 5,cTplB: 'cf',cK: "",fa: "\/abstracts\/search?q=oil-free&__cf_chl_f_tk=nUHZgoo1XlNI34_5BD1_x1qhdnlAdK8Sdg9icXdnBVY-1739783202-1.0.1.1-BHM7_zjsA6Vx1NU1QaUoflBAVgELZJ4sKIuY16B2pJM",md: "aTFgUV9ID5NCvv.go8mTMvD8NIlBZZoPs8XvFiq.lQk-1739783202-1.2.1.1-rcTFnEWqHnFZm1UmY9J3YgsZirfwTgDjhY8CHrZAYn8tb1JI7Y6lwTiP7MCYrrJ1Vh0BnbUpjuBdXGV7ci_KxZHw.I31aZKa6bDQya8r8NwmlaUKM.MYnFKmgqOucjWyVJtom7fvjPsYEeHXFWeqHKveBMC3bQN7kGYp0lgS8rftY6ajx.cAFYeD8bfXhd7jasnts28o5PLtsEU._AiXDjvnceWQDet01wp54Mc61QvoPPgE3cuNtKZH2acXgLKsOmcY_c_daaAkLpWQ_ds70UmT57_7eaOe6ft4PqHTLU64R2gypgvJzxICGbAzbAymqZYNw5t1a4Knpwy3FkVXXwctfHWaliMufFMSLTaQpEqxekvUZ.uAp71ZW1NCUtQjpnAf10GwmsFtzOrCwYQK9UiK5sww0MMq9rQl8e75mDAHNbRcebE8q2mtBkShpgQfKqoV8OMZM2Ze1PuhzlEOgj78BT8iBg8201GZmNR6TG9U6RRq6nxLIJBWBjQyw7ogB3w.1FtH3g3ksxViziAp5uiCKtJgdepPLMAqFDEHgw5agDTHA3uwGAdsGKilwMwVXd.KJ74VGse59cmepWCD_ogmU1SW5QctNzSBORPb08PGbmHeKTVT5Z6acPhUiHxEib_EZV9FVOz9wXDiKGAJ9gdYL5rzwt8JiCn9EFI9W69pNtqdFOsuLBvODtIOolrkh28Rfevwh3BTvrBy0YVs_mPGfxE4M2jNvUj5BT5cATzBLOxOvih5Mell7fvElrenACO27RDOzT_dQFaIQzxgZzdWsXCTvk8kTQrUF8r7Zm_DlQT1uz3ZHtIp.lds01C2sIWYHu8dxz2BWQPESPNy7Df_sTcbz4fSgjpt4NGUVtdnGENDUKgGWRJdslr_123Z.gKjudVDtlTFgkpdfJ01fhLG5faLQcvwTlmNMALwQZhU1ftZTPeyHFyUT0fXkwFHkEtQiD9jEtM_ygIPL6jv12ylSpnyfLgio.1SUW7cBSyYWYP1q6Yr_zTY4wN489I1LFI.vwo0BXk3UwNZmgtRcYFwjoUn0sm1n24SCPAuxENOd7w5b6KHslQ0IhderxdCvvq5pFqyA4m.Uy0qHnh.SrpgY85JIrsjrP6qczBaWKVoK4CcDVqOAXtRmZDM_aVTSFkG7LdZczDqKBRjytttZsOchZoLW352M7y9K47M8LcAQ9bL9sDLdqjsNJheKde7gXXfN8lHpzostgFMIESI1LfulCPjNuzXm7ivleJftXrRUqaYdEeAfcFDjhyJjmPTxyV.OelwkU7rMyBUaETmHhCeNufaQaStS.AMaQqrMjdDvUKcNE9VurwnWF2wXRqRyYFV8OGE4mD_IX0W6JqupvGriX1P56pwSZbOG_frLFZhC784h9H87XSMGwXZdBzIrocUTzMl6iuToZ22QWmxbRBrQLPVgiWuG4w2eadTBavT6e1DhlBMU69FershYZmQ0.pXUgQOQYg1EsjtdHUheD9Dfs6uf2BDEqoa1qlq3lV8poRczEgTzu3xmgPa.4S5uMWC.dD8L93fZiLCgU_EmsoQ31HJ4qlNjCnlB8LYlqXNZd72pb0CsVtMfsx.yU27AwypZ.3hYbtwnFoHAX8rQZEWWuDSip64Jc12u7XErsF7hWFhrob1OjWGU_er07CB0uj1rS2RtAziaFrGwKN0Nlh7ZsNRH4sljFqAGdU1X3TSHGOG19E6jb7SjkC3322QvNJmWsPSy_mIDVga2hk2hKFgbyjcprd2PdZHb32uqrrl7ovE8o5exxvHY_uxfAbEO13enkGZ2vl58LXSDJ6GlVL0lbmkMS3HDqK7xHp5AHReD6VxFZMd8gLAGr3fnY7Be3_RTx.u3o9Lw5Z4I5cBwq3o8YAjsm3Z_vo9dlPVxs_AacHM272Yvi6PomM2F6UGYy6Pa3zW6cJC8siw9c57JQ",mdrd: "ObCGn0NItexAWtI_NwejDnG8gGhDUXlNIoo4HF73CrQ-1739783202-1.2.1.1-8r7o1sKDbRpDsHdKFWqCVa0wGvRbHil_8rIUAkUYYwfamXv_Es.prAotvtswdpnb8FkpP74rPbjGZsEkLLatPBuN9Coq44ikuHlCe65PZRXq2ro96rvFeRB9xXZ770hPaRFfAIewB_eRHRdM3rrq6mtR3KKpOELWl6TwZvtXwH4G4AEgArjopOc7nCpcRt1GYATKPofsS.jZNpvgcf.rslMHoO7eAwcI7cdx_g1xiQID7QOv47TBjZeZBMoOQhy_Iyh0f8KRmc0dQ7A9SH0JBKvhPIsMdl2PmOMIyBbnF8HQnVedHtRZhY33KoH6y2vO0lGgZqyM0FE8L19.RkCwRK.rwpUD9oirKwLyPuAu1Teaepz5zPFsPKGBM5z.QiryGbs.sFJt7BFKOiI3LGrcU.t5vPqIYwUZi6Ishs6axXJ.S5DP40AVzvYHwWCRdC_ygQWNUxygtElqkqYw7ynUQgDtPF1BE0UuWESVxyjcmSnVGdofez67ZVxLAZrvO.feUJW13tNA0kgSkPTn7HEiCtEEW_7Jrcppp0PgU5sFjrsDgOTG2cGwVGB4YeBDN9mu2BNJTNSn0L3tx_Wov5C.qElVemMW5Ksbtneboh2gMxT2BctycaWKMRZHqhbnM9W_upaqaHyo35O.CzJCwWc8TrIDxDShcOK7LBNu16CNWrlfEwPUF1DyBC.LR0wOqayJ2infmggSg25RguTS1MrhS.JdYmP8S7H12_FhJG9YFPTLqqeQWmIMOU_p5LPi8kYyCTyVOZsrpEzN0HkiZ9voXRCquwCtRVj6a3sWPzrFPmRS.WitFr6tVftWh0RueoeaOu1k__2EQoxgc16QW3NlzBK3TxS..iB.gscrH58jIs_VvNi2f8Yr3CNnAdwjTdJ926KrQLW9ktjGDlnZmEbnJQ50blhhkcwpjQAaGLF3KjBvjT6k5EkM8lRHfc2mk8Q_5VssI9UGoQeWcaE65IP_cajFf7R0fRhzRE1VX0b70mc5SxVtkXahKybxjGkekZhxigd0IRbW1S_Q18nFpNzxmEd5KGcnunxzQcqTFY09Q3pns434YujPrmg.EzDsoOxnReTckJE4l2Q40IqP5SOcCE5EQ25QULMirh4UqqbbeZE5jR_Zm_Jy3uDqWdfIngtUfyUt1inH9B4G5W824TlRX8QhGQO3R8x1wiSiYszvXOEz1qAKipQSZjNmJcwT6lGNwMRpJM93o2okNUK7vMxadqTIHAupUuT2i1MhJGsiXun0BvpmdCAluIIKvm1MItHyj3ZEmxxcNN7Bg0TDo0sVHA35T7ufIhe3meLX8Crs32fKjAkGDNWHCiRs_uoeSrDX.4HGfKViz53raPnsuEI6J57xioF3cgZwB7ByZcKIBFxkdNz_nBOd8rkFDWF6rNGhuuCsvwz4fK42ye3y9JXxZRKsliaSOjm89NCGnagULuZfgDbZUFy9Qg9or7q_Vk_WSTXw9H9asY9awEv.pSzxcdqCKaDGAQcyBkzIxwwZAF9Uo_.d.H_nQJnUGomglgwrvS78TztyCA6qGEJ.z38uj7lgX0Qn7CDj5qU4aqsuQKgOBjjiv3jofyczqlSaDzqjd3fXFu_0Ye_HskQrGiY0DyqSRken609YHv.g3aFge8RS1aPx.aP.bO4YDki5aW4v1cGZbSbacpHGPQ3JEDPt5jhBLk6Sb6YUTWmw7OG_2HmokiTZekr6KvEug7riBkxURgSHtA34HKg2oXs4EalmlRV9g1TG44wYXGn3QL0XP6U6VuVSfTtfNVmtKwwVYX9hpLwhB3h5Kyr2JgknAegNkM0tBB4YOw_RKPN7rkowp_z7AE55dtaGp9EZ0DGWQIoXk7zEj.ddAmq7Z76t08rbszlEl51mYIAxRwCV1EPeqitypr6RryEaeTAzLjXm4w0JrwvCqWUGupnBo9cRQzz0ri4i0xsC0YwmTfsLXJUEFGvOpqd_YjRHbgvBpYWtFzu9jYQxtrXP62vyzfrN1swpwA"};var cpo = document.createElement('script');cpo.src = '/cdn-cgi/challenge-platform/h/b/orchestrate/chl_page/v1?ray=91349f7a1bf45fc0';window._cf_chl_opt.cOgUHash = location.hash === '' && location.href.indexOf('#') !== -1 ? '#' : location.hash;window._cf_chl_opt.cOgUQuery = location.search === '' && location.href.slice(0, location.href.length - window._cf_chl_opt.cOgUHash.length).indexOf('?') !== -1 ? '?' : location.search;if (window.history && window.history.replaceState) {var ogU = location.pathname + window._cf_chl_opt.cOgUQuery + window._cf_chl_opt.cOgUHash;history.replaceState(null, null, "\/abstracts\/search?q=oil-free&__cf_chl_rt_tk=nUHZgoo1XlNI34_5BD1_x1qhdnlAdK8Sdg9icXdnBVY-1739783202-1.0.1.1-BHM7_zjsA6Vx1NU1QaUoflBAVgELZJ4sKIuY16B2pJM" + window._cf_chl_opt.cOgUHash);cpo.onload = function() {history.replaceState(null, null, ogU);}}document.getElementsByTagName('head')[0].appendChild(cpo);}());</script></body></html>