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: '913411aba82bfd83',cH: 'AESneaRMDvwHpcOFT9rUWTPUaeSi6AYPPpKwYqt6OPE-1739777394-1.2.1.1-WyhS8ZGKG7tfQdaRRNkbMWkn5x4qXbGmNko4ZttKSyEPUCSB5cn3IpZ.RBU10WO5',cUPMDTk: "\/10004008\/iso690?__cf_chl_tk=yXKxHAejF5eNH4GMr8F3.9GP5BsQ8eynoxdCoWwDODs-1739777394-1.0.1.1-LXinTFzeXKyhqA1lG9rcdmFBsLsJ0WFS4UhXb1xeqmQ",cFPWv: 'b',cITimeS: '1739777394',cTTimeMs: '1000',cMTimeMs: '120000',cTplC: 0,cTplV: 5,cTplB: 'cf',cK: "",fa: "\/10004008\/iso690?__cf_chl_f_tk=yXKxHAejF5eNH4GMr8F3.9GP5BsQ8eynoxdCoWwDODs-1739777394-1.0.1.1-LXinTFzeXKyhqA1lG9rcdmFBsLsJ0WFS4UhXb1xeqmQ",md: "ABzRqiVsha2cgvKMnZSQrZ1XVapqBPy2zxDCaMV6_wo-1739777394-1.2.1.1-Aze6qTMbZriZuttNaIgTwquUVOERKJcW7XNw_XEivTsV6pyjPLPID2Tv5hAvVu9LHh5TTR0hKu1ATkHyJuJ65TdUHdfRzCyAt_qJXKHb3g6drt7vIIoTmgoX3vVIktYCu1EX0qDm3pTYw.gpNqlA9E3_TgBc.NORTUp6tcmCjA8u68u_4.RIyUNYTGVfQI3eF_J.9n7bujX13pKRB6zitklTvulXE.pxbEYQK_fbdqtzzPhrp23LMk4QcuaZ5kyetBGdqyKlo35ckq_0fj97Qg2xjOSdzsGX0x6LmdrIjobRcq8laV4RrBRf_8xUyeflf6J.f3J0BWw4cw4myklgbpPu5QVtZ93y8aeVRVfWYsj.R3F29hK3N2GOkUOs7Qu1ZqiM4okNm2sDbz4p46GRHbmEVOYkPhVztxLbx4GyNc3cd4XmjLNdlL6qhgGlNsG9rQnxof3XCKYvMCZZ2DP8JcjPVlnrhnWIf0J51_i8cqjqqA3JFwGRhlVJCguGqG68Io2AIpyUh6dRiVphfjKLsuk_yzYCLyLYJnJ1QLyTSMAEl21FIFw1KDKBRWqhQxrAnT8U.BsIvfTq1W..yOE5mEoCFaO7or.strAhVYONUMF.7.Y2amMYDEECoykEvZtRZ_M1MzEyYd1ND2pVCjenx7VSMtycMEtJKkwb_FmBHmph7pDEmTOGMsGenVTvvXmUFz3nQhY6HIlZzW0yiD035JnKYsxJSFQDwKhNwY2YqYPlYIRo78pq.fGkTBI__6y_ggXeBeHpEaus5w8Da8BafUdlt34oYNBzSo_sz8TByu2jCB021CzxMxkIGLVBR0cj4gyStUjxMrqB9n6V8em3x9KWDtrPRGErLBg4.DqgWfBIF_BZwUhbyUvGcM6J2x5YgEfaoDhMjsVCxeoElDJv7EbWPPodAxj4fwz9REE8DU.1jhM5wWlLSdqbpfUB.m88VtFTkJUF9iMpPXzCURza7M4TCoKJXTZwo3LEVYlPr8yZauzWXolFGBy6Cnjvef8TOIPtyfZAejXocP2oasK05gtu8tFx8ci9QUcdKtVPh9krREN0DNKyhcDkM2QgCuX5ZSk56h_XQLfm2lp24rLAj3..P5MAFsfSV4o3dDfJ9XDg5.NDs3UwUt273ncDRnd5LFaaEKfV5NYvelDZ7CloKN.Bmao_rj29gKvnE.V9NX0zmTeGVTJFEW70gv3rkENiR18STUR2uuMNN3xEZGhNX6L.Urip.kiFtz7T192DtgmlxohbplWm3wlXFPgjZmA16hQS_.iWTxKHAbYlkTotpsfKYWdzlIX7WUQfgw2ZYawePM1sSihsxWi61WoLImrnm_hEl_EADrJ0K6PKeWcKRpLCUPi26WZx30eWgp95X5eCZZT9XwlTNH6_xTE_O09RYWNMWE_KTaFz8gZYMAFq.mWZEoTCzrRaOg3wMFd6thhakBxz.2aswhDarAu9FjsCqc.pVS.pYE1VbKCAdZsmrBN7zjsMEs1FPi.ezZUmbpzVYBSgJHFZNtn34t1qVo2KXm0D.VwSpSYpDmFVoX0fdHPUKm7KxU_iRMO6xD7sK0f2WogrGTORz5tHi0gW1ym84WRSzNIlITGoNnP.hmulLBzGu2Drq6wFs7uY8NqKvoN5Gm2VqUpGmHQYDCw8ven0jyVaB8_SxJV9yNPwpP8KT71r8M95KE5u3IskS6G9BL8KKJJL6gdQi4dIftBTOuJhsk64jd8Fjm_bKxD9lrYSb5RREEHFbcgNrw86ubq7uZvYlwgKRAXAw8FzPCNUWyPKWnNlB.kEnbGGeIkGt3QKgvnKY6cVtLyfkCvX7UaGo7INou8vjcepK5QGJaRniLjyPyGA5mRUTxhcKiu6GLnXrmNOn5yTpf_8Ji1AfuP2kzE",mdrd: "ZIb6bCOozZ7YloFeUaPH4_UDvqpkV8cpk4SetQj0eHM-1739777394-1.2.1.1-8obqvxHD5MrEl6toGBoX3_WRjhovREiS4jT29kgLrKeGr4ajQxqpJ9XCtqz0jNQJs2e7dQdL7_2OKHvpoi_Q5JvY1jIir7WznJPfUAW.ofkgsEfiZ5ZCMJMVkeEDZwKAY6IPdOLL00aBlb2lg4LyH9KvZCKfy.HrCEcsDoE3mBw6XK1ir4jqotwM31xE0VE3L7XYBiKDny.TPGNZRFmSftDWyVmn74Es9VW2tsZwesznhBfofMvS.raEABEMLzD8r_sPXAkxC_Zr1Vk4DkoOtbjVKJvfgd4o6voy2L1deoo9BpLHpuT2W9gdLDQMp6qnMdCtPqzsKYGkelQwogD05spCZ7GCUMzPa4W7nHRrKQsBxQGtj8vKOpFrDlMVefBPUx.i92Er_LIyyeVKD83Ha.FOl_sLN6rNlA9_xIu2b5l9ZU_KkFSSbXScAuc1KRaBngcwCiY2aRG6Uc1szOuUD2c6b2UDgBLkafERnHM31nah9aJHhzKfpgaZyq09dgC4Rea1wN_dyQHLslht6_8tuB_pBWQJ7XXq4NiN4WC.8Xdb0fEhoQWpjtxd1SeHGmOBbFnBotnD4CzuMbYI7s1NTZoCdbpN5BxrPJiPf9cZKTuCe9Vxu4hfSXrM3JFoh9PlwyViNJf1jNQArsBXn8LZFXwIKRzgPqRnjV6ltd9wUBaGiyIb0F7gLJssNS_.GoqQ175vpOHNlhLHUonD_xTMRBJuE0Kg5s9r879uS0B824Ut4x0OgwjUg494aZ.YkhygTPAJXy5fecy5BL4STyz4VaZxNW_Qjt6ZafrLZo4Lv2nsHNMtHXOiPr9GRk9pd3iQn9.xuDW_boe1Glqhwxf11a7T4eH04hJTKOCzsFDao0T.nWV1awJrPKtLMVgBS4vJUpePJeFxhcabZW_Z9Zwj0gDLl8WtKjBZfPuJMMmfuaSkPe_8gmHsUz0X90E0AqO0neCXl3xtTwMnNTEfgIpQ73UVMnX_w_cf9yLdTc110gekb5NREMrBswUopEZzYYFnfUFbPLlpeAyzT6Lx4EOapZG_E3HD7Yf9nNnMb.Kjb.39ydykJ1YyMKPzYNwVRO4YHiuCVUcPh0Y6IqPKUfebCcW9Hd6xkJor.KcsVPKvpRLT_g7neEg_T1fXYeRN9f0w9N3r.se1RN5uxJVUtatfNPtoeSTGQy0_7RE.HQts3XCTQoOLKXToLcN34eBP0_46oE7rR4nCI729PCJkW4zQBATSVv8KDGWnk.q6Kqu4NKWjaPxGK3aKMW2Huetvj3dXvC87D4O89bqxbe69cxLTt6JBvd1u.8.BofzNNM0eeJcUZLbBeyeUQe47pPdZ4BwPlicJozcqJ_ukd3H7mpLdJNvARrWnWlgRPnwAY5Z2EEU7hiHcOXNCS_6g7JYhP7bb9KtYb20H8kLrrEDbPX8GzzdZRGA8dyu5pN96xXwFlYjliqbFlaLC3ntBLHOubjilnqNeOo.c6D6_InNGJ3Q5jNl0GOph_fwayZMqlF7m_Sd5I442yppaI08fqzv8kDa2J8yQ_d7qOfHMRj7FXn12jLB3dF2IJt8gBmm0tvBOEkq5x5EB7PVjmWS4gaHCcOub4nZWWXw_tauqOGVT.7Rksqb.WBA0bQ6AEidLxAnPm8QOHAf_gv3KomW_PIBI78PALaiQn1H8fD2LkBd0.0zPwHXk6zhvjx1T8Mu7BxXrfC.c0x4kRCbJFzCOmsS7yXbIbc4873wF0K_BKi6SMl034xrMkzSijnJEEcjV1p3.2eg7YcYjbMtM2n7HcmotS6tv5PRuJxKen8e6k7fH2qmVK7N40CSkptI7ZZp3VK81z_tv7xIcwPszwY57UaRrtUn1IWoP04RJl69gJ.i5e9_M0PEe8yqeeherbZZeshDyxdDUG8oDQi2nVjsKNE3vSh6lvEsjGWgS3fZ.gmz.LfHb6i0Y8TXJil_VzOnppZ4IF.e2oe.3Ftf0I3iWa5ctHhy0"};var cpo = document.createElement('script');cpo.src = '/cdn-cgi/challenge-platform/h/b/orchestrate/chl_page/v1?ray=913411aba82bfd83';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, "\/10004008\/iso690?__cf_chl_rt_tk=yXKxHAejF5eNH4GMr8F3.9GP5BsQ8eynoxdCoWwDODs-1739777394-1.0.1.1-LXinTFzeXKyhqA1lG9rcdmFBsLsJ0WFS4UhXb1xeqmQ" + window._cf_chl_opt.cOgUHash);cpo.onload = function() {history.replaceState(null, null, ogU);}}document.getElementsByTagName('head')[0].appendChild(cpo);}());</script></body></html>