CINXE.COM

Just a moment...

<!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: '913688ca1bad3fd6',cH: 'd7M2G0B81KU3OqEorqRLJFmU0UE6NSvTGoJZYCOjEhE-1739803245-1.2.1.1-T.uWpujzLaYJnPOSTJK7P5zTRZJDrKn82469xDPKcuIOPSITYmdFnJBFCmA.GutO',cUPMDTk: "\/16937\/advances-on-lugre-friction-model?__cf_chl_tk=gEoZqJ8uoL2qvG4Jq8BSfnF4BwHs4SH70NaX15TYUMk-1739803245-1.0.1.1-_Ys2H1ucOuVxZAwHjtEoTRQa97A57hFja472ArHL5Ag",cFPWv: 'g',cITimeS: '1739803245',cTTimeMs: '1000',cMTimeMs: '120000',cTplC: 0,cTplV: 5,cTplB: 'cf',cK: "",fa: "\/16937\/advances-on-lugre-friction-model?__cf_chl_f_tk=gEoZqJ8uoL2qvG4Jq8BSfnF4BwHs4SH70NaX15TYUMk-1739803245-1.0.1.1-_Ys2H1ucOuVxZAwHjtEoTRQa97A57hFja472ArHL5Ag",md: "OuOkU4Xdd.5fxP0XkixY89u7F3YW_81_ajGoJIOosAo-1739803245-1.2.1.1-fpq2.gKdJcPoqWN8EyRTEl.KTHV3A4f.zoFHsQA7pzNxd1KxrG.7wRJcWYRHQNt7FMkDV4_r2Ae83.piKD9D3eQCNTGFL1FEdGUJaLB6QxZgwMUH.52TfjC7s1wG26M9IkMyz7Lz5np2itA3sQlWUHYImwCRXZffkU4K27rNj_2zaLmVOBD2GyODPAdjMNpT2tZDoL_Qybj4OfD1p1UHpYmaMoq1mknsxALkxXASM7Z481IiVlSHQRB8uhGhzgAhvx127zgKW.cNd.s.NsGu5dVOHRX.EdHqHBJYub9SevV7Dt.OD_J13Z61hbFBMEryI4g6c1.Lapslyno7FRD.uFRaieUAAWi2Al1lFNDpaB1eQ4s9JubiK..c6_H2Vsa0IQWLRlbTZ4Q1fny_PYtN98SPM5NJRQ8CeMQ91nES95P7MBwwNf8e1v1RGX8D2q1eoia50wGultKjMEV0YgwrOivSpu8_L8sPLMF2GuVKHwc2SGnoQ0oOYGkF7L6C3feeUzbHBMJ5EcXF.jzkPHt65..5jsopT.tPvc.OdEF77oU4t4yc7Tj0G.jC10ialHLj89oaZfi775PCFE.gVOTZtIKKwARk0FLNBSf25TBRT5amWifj6sht4pUANN8J03kTIXtElK.V87L4P8tLp8KeE76QdVat6Ov8Eq4kFoLZJRBQ_DACILVya5lFjTut0Bvu6HBSbk0_0Qj.O_7W1gG2H50i64wez8I9inMj5lTHjK3BGRTuxsz90ri7vwVl_gvlqPt4II9IP5gD.q2OAa8PiwqkmIqsn8PLmx5tKZOtI0wEnmBohLQC68pyL0aKBg7ADvkVL3imjKYtW34ahlTgf2X4q9DQfVpgUROvi8lC.3wZm9Y106ukesvmrcaGUcQLx7FHGBya3AF0fy_hGEtk_JpaHQ8ifyKF5NZG0pIyCsPxKqa0L9ZcQKAux_Ubc7MuR5lFYPA9GO_nZDHh6NPUae1vAGothW6WDjsvVZpLC6NFYZw6w1ovK9ApLdo89r2bzCdQ5TYnzKDNPmbaHD42uBj0oniVSUVKkwbGzhMnsSBKmcdMNAMdtgaco.9aoJQTapsCWEJE36Y3GtN6iPOLQyluRsLUNkpAWVhIO8GP4e.Cx0u6AMok3ms3gUllss7T9E1akLTDMW6cRMmo0oRU3UdA2bv2WzXy2aHzZ6bx1yW0gnEfeR.FmXrVFmUg_sCIJfZ5MgRDaTwYA2Bj7i7FBx3YAPuJBmmSGoW6BSj1jrddKWpkBDbJgBimF6vLQ0yBQkUCpDCSsBL03qz2aDXqpVNLBoN5m._nIpTrZ1oCSnzzQs1UG3QTqDFz03a3zvewZ2Kevwd0nwgegZzN5UxuiSkCVrylPSw4jRRBkmrI6WSyfTf4Ja1ddgu10VFFtZPgHmbkZrKUyWlQuuSzcBCnyxaTfoQ45Tp1MPFwAdPQqBiTX6BhF.9lg9ZhRucCTLsqgvrtPTyGl5Wag35OKIrSaOaSvetl80M1TJ2CkO2VF7OJvQ9SuSd93GTTWFt9GKxTydb17n7ejPfrI86yi2Hknz88uCenaY7txE.DsqYaR_J.lKYrVtDwpYAl5qfG9BKOOyWGDg2kVLTUDW6jwaLe86RU3I_Qsq04_9qa5EfECBukKXX0iPnGq05aJHb6rQNqTHrVqkr8vM1x4Tv3p30pOF7PMjbbpCd4ofNYB4_Llxba5kYkUHt0I75_toQQJ36TyWZRmOLlaGxYoq8tbw3lXdRZKcXpakbMzHMtYIO8BM9vE.BIGkdM4je6IH1uFX3xGOwlt2lo2crgkwSXODJiDW77aQ.llbK18lTXnKzNOKjvsNfT0dZ8xe9oWA4r2.xN2Jmgz5TL5GoBfEnUvIY1T74QpTtjhlix2muVM53f3IYMICZMBq8B5itUy1SSfg1OeA42tpyNdiGNGX.cNBdvkfEGVOQ0FL3d2uXo35dqeUw",mdrd: "KXHexOBIo57f7Kw5DxnwPjnJRaWibw9L9O0SJ3fVYlQ-1739803245-1.2.1.1-Ga0I_ZT2XLB4IbTnb8JIsWrmBcel11jsi0g7m3URxcPotL1O3wLrZiSyY8K8OV21DjrNYQNjC4CaX0kDJZWoEYgt.agP995lndixJm0Kfi3e7s80NM0_mkXALbMP_gVySTKllwR4A9SHPdYMPqeYeE_4kYPHFY1lDT0245EAdhbYxBMQH0mxA5G3eo2DbnhVkmQylUJqzXwug0md4sMPtHMGmNBHW9R7LVS68ha2HmKygMrNH8N2mD7e.zMJqeVl1kodEu5fsO2EhlPQK8ymXezRSCZEpSo2yTuh1igWs5_t0hxs56gMOQSsM_sN294LW2fwc74ZSIN6FR1LXyOL1qEVT7EYzidpDd2ZMWuywmZ0bVoWfWp.KgE5tt4NByu8VvBALZutveengs2KMRlBSIOyAPr2lJT8n1YQqhzgx9f6XrZsfIkb6_0cyOhWL3.iY3XR0GN0SI90mWKINq8pAsxYpGkOZ1tgaNDe57_j7H2UvZDuJgGUmwwgvUWjv.tlDFjJZyqBDRJNzwXdEiuo8GMyWHoqeHX7NzEdvma7hhZn66w_zOHWUv.zBtLIhkfZDTQPDMJr8zkTsNNtJSkOhEaBL23jB6ye5gk5i4U6_Emon6k52rYbdwjcSS8t.bWP6kukFFDdpRw.Amf89SlybApTI3DfYAR4TSNRkzE3h96nDe.dcDkETNLq2Si4kZwiRgCTIj7w.THFxrzI9dNwuMyUfNobiY72ksnvWCkmx_qpYvq5aJ4ihs0BBDAsK42minqi9gZxDxiuUqKoTtZTifGoC40MQ_cTNs2D_FpGU4kYd2TqGL2xLVKF9RCMaRQRCadycggSCLlx7_0isVzOSbFSTDqlvUKBmb6n7gQJtzUX0O2uFZJ6FiCLbLtDmU67jLLZBnQQqV2fejKMj3v5DMveKVcBm.3iNGCOjtfGY1DzTgDmcqfDqXpK4kalhOKA1LAgmhuFMY5lLI1Sf761SL7mP2.FH9FFi1j8OspBiRsld0hkLD4Adw6BEZUvT.Ii6YDdNWMRpfMGiutdqGMTAyJcXSeI7s7JEBBvYbbLxYRGKsP00InoAvVTlPWb9opzr.Y7ysRak9Z_SrAgCQmugw0RKkinPTsV3gbTu8rmiWvdvxEeHWu7Nop.4F7ZSGHtsxpGLvt4sgG9XSdsvy9VXk7vZHq0osIr8Vcs.HxwFoeu078J5K5E4SYmD5e3RxT89TYfjJTSzivn3nYetbjHuHExPZ6HReKDh6hM0q6wXCBb4.88MLJCpfmOLRcsxV0ktLDBTGJezArFPWMx6xZZ13oIAIGN8HH0HEkgKhwX1TmhjgUnYu__V47MaBemc3qWWMHECTVCWga8kLeWkgK0TFOMSOwf.IlQrLGvdey9wBQaDeaV1hw4nMnl4ozAUNe9w2r2Mr0TtsZO1TBPYDglY61r7sxmhhiBACLm9H2RsHD1rPZqCMIXf01UhkwtRsOOmoUlgNAXBBXemyXjTQTF7GoZG57jF_4ctLVDOrOV1GJVLilg8xEYfvfPaY43ETXLc6Tqa36kCGK.FMz1BCk5BhzuHwpgxODo0wNGKtkFQcVVvp3jPnpPhu86EXNntBraxLHXe1W6mEjDHXmUu5aiIxy1YPP7xNcjctAOEjMlUog6K.MOIiDJ9l6F9GTfIuwzuev2Adq6OUITi4rEE4nnZr0P1PXmK6f6HOq1_rpWNImFiA8IqIOzX1IwDKEWkq9BkY_L5BF6_ednioSjNnfbwe8s8V0j4VdFWwrsa2C7uvScb.04B1PVoJx2jNv0aX9ySxsGIe6avLQewjxjGIfcXPzMkDCW.N5naWnJDwFwokElcuRgKujsBl7GVSn0681nKOdQ38Y9kQS_s7ofUpVDNrka7ZVa9_03P2TUejbmJ7Cg4ehtnzwdqZS89tL9RbGkuTNQv5f0F90_blwXb4krYzsSSy_jpr1hZbn8RU5bbbgR4q8U.R1doDG9M342RwJ.Z7GpEjp_Bgl3J2U8Xbk3Zw"};var cpo = document.createElement('script');cpo.src = '/cdn-cgi/challenge-platform/h/g/orchestrate/chl_page/v1?ray=913688ca1bad3fd6';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, "\/16937\/advances-on-lugre-friction-model?__cf_chl_rt_tk=gEoZqJ8uoL2qvG4Jq8BSfnF4BwHs4SH70NaX15TYUMk-1739803245-1.0.1.1-_Ys2H1ucOuVxZAwHjtEoTRQa97A57hFja472ArHL5Ag" + window._cf_chl_opt.cOgUHash);cpo.onload = function() {history.replaceState(null, null, ogU);}}document.getElementsByTagName('head')[0].appendChild(cpo);}());</script></body></html>