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: '9134f98268f3135a',cH: '8I1bOa85BkLbKyd4kG0i3AupLVx1P6Iz3XNHbIU1T_o-1739786890-1.2.1.1-pFQCsR1q536bTsk4RsgNbYuwLnY3ibbrPBx9Bgr4Hv6N6X.L9Pr_bGaK__SxO.Z0',cUPMDTk: "\/7104\/iso690?__cf_chl_tk=pNOinZa.Nj6xL4t4wah.nJkfvhfihcblArD0PEEax7w-1739786890-1.0.1.1-_UJSywZmxBvDcVtgALnbpNFA_ygtye2PfGjqK40WnNg",cFPWv: 'b',cITimeS: '1739786890',cTTimeMs: '1000',cMTimeMs: '120000',cTplC: 0,cTplV: 5,cTplB: 'cf',cK: "",fa: "\/7104\/iso690?__cf_chl_f_tk=pNOinZa.Nj6xL4t4wah.nJkfvhfihcblArD0PEEax7w-1739786890-1.0.1.1-_UJSywZmxBvDcVtgALnbpNFA_ygtye2PfGjqK40WnNg",md: "dayh76vSzy6lj9vYSrM9M2vMxR6aLzvYirqXKGpDfjE-1739786890-1.2.1.1-jrvj53ElTJVuOm8Bdkeo1tSuza_jF9O_P9RNc4318Q6n9sFNtndOKev0ud56wcWZvNA.daPxUZ02NzVgIU9q1jJEcDTaCt8U7prpDxcdIOkb0L4yEy6piIUo.n7sI8szZ2Ik8mUqAx0Gc1I2DTHbLIZC2g_k2lsMekq9MH9GbynKHb8wEUNJhVriGwfOwvtxrH_ATvbdmArEK819oFsUVMiYdEaLO.gZTXdImDZeqvFHs.qqMzxa3SxByycecly_mgH4QYdtIP.26V2FxVnjCii7h8hjlkkxPZeGBuuspwAmckBxSul0qIa_tmsUzYWB.RsVWrvANVzpe9EwiFBzER03XXNmp0y3z4nk.eM7Hmt0Yede2h0D939STiTTioarO9y_i1emYjQKpwI_FnlvdebF433STBuNt7Em4I95H8QVda5brHbitaiE7lv8jAeb.asC1dVpYkCLNdlPbBIyWnex0sP06IA58YnlHkT3eDm7e4c15fz5QJwY.fAMfcu6w.3_O3iXE_pQtT.qOEpZnZv8xDm67V9k0tnGZ95RdCWGoC5Kc9TssAqE9mQxMEIGTyiGC0y5WQ1gmDeLcFvhqL1uF.IWS8TNSAhhi32uZ6rMScgAi_tfWEerv3JWGxKEPKGw0kiaWpFKl8xp75ebj.OrlzDYNhQuoSN.RjU0tixdGdMptk5b0LBl57MLi89mIjJyYk96X8rXUj3R_2.CuJ9mkPWe.a9oy99JkD4oxqW7cq6IC4wIw.PePFOaOAWe2izrNk3ja2xYj7aEQfifjIRptYIdNFODxNfO13hZWcnHHeyVbVeYQk0i6Y2eCdDuglfqy38XvKggCba6PxhKhMBdsEx7wazP5KZG1jWvoKZU0rdAlHA7bD82QLJxsKLyQ5k5mrqxdbBaIyXDZ_rkAlSnmAjE1Q9HNomP4DpTilU062xU1hMtp419W2d4yFQ.WK9TN5maDK3p6DKO.84irZ71QIXjwrCncsMm8lnY.y05WYlZz_kRyljJdLI2yHaY4j_wh5LF3pGWLjie9KNVUyk1BEaCXB.WRo5Kn2M80Gne3P5m1PKLMjyMV03ry7QeN1ZkBBvN9MzJdhMhKtIao3JgHf0cC7_9SGcJGeDcIiZhsibJFqHZY6LMxTC5r_ljK7KWNcZ_gtzDsWrqVTFxkXI0QI29K2rHu7_IjtrB4G_FayRkyJnsgaAPZczZv4r.e.536alp9oSFqkFyAY_4pSydgHhciPES8suAsgfglsL1Yk5drATLyYCQDawwF49xxsL3okpEzaVZ0uGSByjok6dkiw959BjV8t8BXCZeRjfVjDMVP7YY9O33TX6k7mbdX1TsOOk9HHlQN18pXPvTiQCHPxFTDf.1PBIOdPDHRII_hlAPEJrfpyv2EI3PYQuDHKvtlyARmh0EITFezImZks9edF9p5gtVfidSD1QUF.z1wlx5CoT.bAFLVtGvv.vnmJJ5Gb7zp2csbPLfFvdMqjd0.OzhWajX.FobTcohKctG38t9i8xg1Bkyb46AZnCplkrRe0eJeSNGXHE67IquRyEBeZ62JExsIfWQTagO7iJSKHChsxWlbUJGnQsoxy3hW5BfJnhea7kpkJTLVQr5s_9v0KsqtIObGwSccr438hjhswWd1Xgd9D5biAXr88DItL1DMOEzR1FvR7XZf3ouIW31ZbyvtJANx1VwQ7jEaV5dq5EayueEj_1kZgxqGu4bcyVj53G_FSTZ_LR4B.DkV4BLAD6bhxMSpKIg5D92B95SYgHT.jKnKPtC0TeW6lniobAE0MDXDIdmu_oeXoV1Za8WJuPL7Gb4I3URK62QENr9.1ErnChAbyf7NkVWOzjZ7fonNW3prXbF29aQhThi.19i9hD5l2N6dUYUDBSN6v0",mdrd: "bjXpu5h9YALvNGa41tewIaOnsRdNxX0cQRCwhF8kLI0-1739786890-1.2.1.1-n_B1.74Nq4XuMcP30C.c5tPIriR6u2GZ3g2fG4_ki0YasWVamU90CZ6OqbEFPogXTlKC2pUfgO6YAv1p3CPA5mQUF1fqi.y40rcyj9lkvE3LfVNnGWfewoMb4.jPflTuiEBPbyWAHh8t4Awe1pUsNRdHK04_lObhDIAiQuEyVVGaYL3CeZ8CjvROFt.3J5_Ta_2z8MSmnmyO9OzQTds2hrlJ73PTEQe6B_g7eUGIc.xGstbg67ZYfNzFwP.Q_sm16jk07vzOAh1uH_JXLf9WAliK0b0ChyaaZenCfvzSE0AjTszdG0jRihqU.aJoqt1oA7z0QgxjK1g5HF5sKcwfLb_PxpUCItZrpYGFZ.tNQERv60gkLTiUE3ncyBcq7c2P45kgAOc.wsYO2SjL6FuJkIsALplCgYLuDLWUf22Fb.LkxMwqC2u7rGfNoeYS.qhJAnwK0pdnslzIzjjDdAf_XBInHloNy5CJ3O3F7sOH5NeE7dKbLVbauymV71rH4_KWnrSNH6R9vqHxE8q7q4o7Mu4BTicsY3PS3W825vJqi.DYN9QjhlQzlJammzOOC65G1UIsjJVZeVBH8Y8.DIhBLBXCUIUeu32c0kpRG0snzcXHWLnktFShIru74n_18Tdehgy4EAftapRxvDj9Aq98abkSZd8NTSglCoM.rI3JVTx_y1X9P2KRNggEFG1xPAt3IOlH.xej8g8McTZwOzCkNvAU99t55q8qLHOiZM1W.skF6GCUF8VXl9j3j1tVKo.1E2kYnMTYTHiWWAVd4EHhpdptmQIjdki3DvZcRCXhHydF6jB9D0PlQggea1_vytMV_reB_5IaCMDF_y0nFf1lEmOCZ2j7KANe91V06nvFPNIuM_eEdXnco4Jeh1rt.An31SY1dT4R9UkuprRGEXIPgpfu9EYPzMc9bW_HwpDlHV9yUkkLjdz3MZxf5TUydG7ywQCzU5S42VM7TMhJp5Msz6Cr0KiWxfcvw9frBywKsQpXDxJ.oCTZCmak0nUVemHHPV_waAUHzwFhmVB05ON90qDZ08eDlg2U2ImdgALNrC37ZfhdRlsI3rMlE9.jvAz5ji.QTtYbtNrIANz3ALt2RR0xwLL3WkaAaOk6wsK.csoZ4VAnwcBG4IRelpchcobQ3o96TzXGmjVCTUsg3.nj4L_0I5ZWZm2AKG_Pcvl1qpBWIb2Q76CmXGOae5A99WU5x6hzf.6zYCcuKkYw2_VPRNQtLtkhrtOHCTSztjsKtfZi1OhzXbYDHsNjyDexci8vhIRFZukKZ_xOxTqrftYq68dJxP3e9VO6QfwjSlkW13rwMwIIbMMZXoihTOO0JWrgtImne7dBMFGL6YaiwnXJgylmgBU3n_5ugZ4oof1hRNG9RRKUmOMFk4Y_nfaY5xbaFiolprOfwpqLx0AX5z6QrwTldII0DR7gCTE3uClWJKCNFZdH7x1BiDwKD4H.0_mcP2VlG_bAFuUfyTkvwiRC_qSnR6Yp.etRtOCWBCEc9NdmNWOUnBlpsHCLlGn3ITeKqU510PzBGB5PWD0RTdAWueUfpYM27hxn3HypWOa762LNI.OxS6ghHZHdBEWeakgMPLNU7ZGXmqZTdowYZw_vQgBYrgUDjFeg8mn8Uv38rMl8i9lqr0DZJdUNoTaZAs5WU.t6q3cigShL4zLrq2kXYTvOoSHF38IDRB5fvd2jS53b3O4kyeHF0ShYRTgFIkpyHeT8.5uJf7D6_FAGCYo9rV8fpDJd4n3S0PFiiJVqZgB24ooZxvZRxWZy1Q2Y2R8T5e2gay9oF5MMh2kOueoVTkZZSWH825frix_2y4pq3uRqt6uWQusKGVCkvAXNvau0dHvISFFrjY0wzEVSVLFocRrEkS9_FBGZlVQ4_NUkNR_4ehLhdHh8DEuI9T1QcM28xLX2VOtQ2eJLIjyCZYINN6WczGS2Wb4M0O_L5jAN5IWdH4UKVnfFZFkOEJ1euOFZJU7RQ7ui1dGike3nb2O6WA"};var cpo = document.createElement('script');cpo.src = '/cdn-cgi/challenge-platform/h/b/orchestrate/chl_page/v1?ray=9134f98268f3135a';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, "\/7104\/iso690?__cf_chl_rt_tk=pNOinZa.Nj6xL4t4wah.nJkfvhfihcblArD0PEEax7w-1739786890-1.0.1.1-_UJSywZmxBvDcVtgALnbpNFA_ygtye2PfGjqK40WnNg" + window._cf_chl_opt.cOgUHash);cpo.onload = function() {history.replaceState(null, null, ogU);}}document.getElementsByTagName('head')[0].appendChild(cpo);}());</script></body></html>