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: '913397109f391ff3',cH: 'zU8KWzkjyPG1lfzvwzpgueoonsf3re0l.d4Em1ZQDY4-1739772372-1.2.1.1-Ou_tYpsiKnS_6ySfq4b926dJdP4RweHMbKpv.rUe6C2bX5Q93X38Sro2RNDcYwO6',cUPMDTk: "\/10010116\/apa?__cf_chl_tk=LL_USra4pEELVBc1lLtHlogV0nZg3GyMd5b3j8GopOE-1739772372-1.0.1.1-SguVga2uDQr3QlrShiATdsxkhE9_krKUE9HzbXti1cA",cFPWv: 'b',cITimeS: '1739772372',cTTimeMs: '1000',cMTimeMs: '120000',cTplC: 0,cTplV: 5,cTplB: 'cf',cK: "",fa: "\/10010116\/apa?__cf_chl_f_tk=LL_USra4pEELVBc1lLtHlogV0nZg3GyMd5b3j8GopOE-1739772372-1.0.1.1-SguVga2uDQr3QlrShiATdsxkhE9_krKUE9HzbXti1cA",md: "x59fVvoajcJ_cJCByBx_XyUAj3ENlEH7RKSHsYbrM6U-1739772372-1.2.1.1-b.IhshAx79k2qUhenuXsz1CgaXMlU0ayCBSYN.I_38u4cegORePdYdPmSfCPWN5CtrokYh5DmSQ3mBPYKUa5w.8VnV28zd3r_zgtWT0KQNWk7.fm7xBMM.IdxIgg6.VVcSKcB9n5oC6uOy_VKPlQuHT7l0ztKfF_ONKrpL6ztx0SyMDoGSCD6nrLY6dDdqshm4VYAMI_wo.pxW8f8bXBE2OMCahuShQniU17UWSNU5a.TuegTMu4BltQTdqg6mZnfqUv1DeNcuCOKj_XK7gCZE3JnwOUGA6yTxyB9LJRMgavJ.NElg76uQhsmDyuZ9UMXvAf3UkARw1wJzAaDD3v0fhK2H8JRJyqQxkRPL0tX6tBOXoQ0TYx5KvEG2q_NFmdCjIQeKVq9KKiRCy2xhwcM0S7cKHIVpyfBOB5qGj6f_EZDGyEXS6LEprr5eNpmm3AAocJ9zyN1byAQYW700K8opJXTuy6X2iBFbrZnFsEelSiou1fd0udpJXfujhvnGv7Y6f3R42eVxM3JQlyYOe4XJQxWZP3.Lm5vDkcUabQVIXa2h1H79YQRLJXBkVBqlmpjiYU.aA8jM4_RNJ4E78sYggZAMM8xz3GSVQDLIZgbcWJPMcniFzc5WPW69M4EaGuNvNgLrgbO7A7ID_NWBFRgoaQNBF9MZo_CwRkg2wtQT2peMwl.4Yo1XxRnd37wLmDLnheakMYIX5g5fNUTGi4x4Fess8.pCuDtt8sJL_h2bk4fMvlHrc8RAmM0_fGteFqzb9EYxIkJ8kgxhOoadhNUIbSHThARc_LheoRnwjtWUSi10uCnrmp4H8ci.5uR0IqyeLLKbG5ppThLKSDI82WEXpiApCOtDaBttsP1tQ.LmXb89ukiZxv0D.eV6qapDrZBI2CYBLuulWe.IXnYqXtyJXzfdlKJyBbIW.4WzdH0g14QvS3ewdzGLV.jlpkkQ0iuc278iA8WT5EmgolOMpQux9J8Ki64i3R5KSBdEw4euaHz6cZ5m9MBWM04wtF69TlCQNFYG5a1ALmx2eH6t22k5lmUs.49c23oVj8N4gqHQSrALV7bKqcMWQMNMqlAvH7CBvV8bHVpMt15YEgaVCd10xjZJV4HqPbgPbfsXw.F5mRmPnjMjEVFJXB82SeF4udc9V9sXEBVxcfi4l.Pyr2Q14mfyZSFxxUV64PIAW5nZWq5Ny8kp0dC2.TMwCe4eMNhvtgSlcOWXgOIrUINjwo6giCnBO.xPhnfNtZ2wqroE0ltfQvmqTPgls_lHgad.6rtsULfg2xBv9pXZHYc.ut.vhCHavCP3SrMjNqS4RBRX7u9zK4mPes5tXRSXZEQV8J3VVCUz5Yrj4Os0NYTxWbUH0bI8mueuMpZG8TI.GSczRF7j0f2UqmVDcqPBanHuSA4P9UJPZYlzOpyVultZdtB5cVot8DMuboANAqvSXx0U1HmQiawJlpa1zYjT7F5k5mVUiy25MjL_G8AByyPEaMDuaxftSIdbxVg2qmAWRQNz5fZFGOuQZ.zK866Ft_1Qgk4OsISXVIvod_DRIS6KgxUXtsRuhDwKcehgOW_SrqE8zTOHmXSqZYF2INpD1EIRsoFeTtRH7tLGIb9g8IOukDFxtu4dDk_CvHx5ix7MXmYCGiT9EsSqs3NTnh7cc1pRM7jUHZLkpRuVCvmLKjIH4mJ062ER4aEsm9ojAA1C6ejn7ilo5QSIEEi0fXODWS3N6Xany949ldyKKjU8W54lyTlHGSaZeZShN.TurxvC7EiMvQA_8pLktkfAGjjQatMW633r.g6lXSUtkBnl9RDYSuUk8Q8qrgB6thWCoL1J0fWnggF75c57DSeOF6L_zKZlyBS5XeDIzikELNL3R46kylPxvHYBoYpRo.fnTvnRTlrJM",mdrd: "SBE_H7Svc3jSetz4DCBIFNU15y0W_5KNtq3i1hBTY2I-1739772372-1.2.1.1-QT.YYZxgqMsY8gfmSzRsv1h9PeRslFuU5XOp2kGGZCG_DyBX7We04ozwvZjT.IvEQ8SkuNA5MUWOihrOR4j0op2EMWZIJQHe8q4Wste7im.FTdyIBvvOXcQdAR9UYbkoJauhxCXIvjCOsdERV14IQ_jjwF568kWkx_ZpJm0AFXUbsFzVk9VWYVaKOektpEoHcOLBhSU8aFORfCvQuRmuvcXGEgCkKgo4HqOSesgfLyELvmXQT_z_FTPyqvQbRx7aseZUw7shh269rRG15od.ncwTrbRlfR8lheoj8ZQu6PhuDBZRM5gnSKKxYiGb96UKm0CKATsKxYkgxkDLXP.Evp0msxG_PXmtHb2BbodJ5xjQbNUFN74VSqzoDVgsCqTXotbbL4Q6q6f8qbiyCIDg2gsPmILaszWILijbO8LSw88F7qULyB94HeXGean9uz4szwnPkc78LPxtcZG1N48ubwViXl0YijQQ2UZKu.6aQrscwjnN7MKGlK01alXaMiwxDXWvAoWqkyE8k4fzEVGq_KyXvSFG8I._98BAtg0QjG.znq3WaLCRln31cKhbaN5OkbLv1YZrulOP_qiytQYZO1wIjeNObTTnuDuxebC3e.BkXURShd6757uSRSxrV4C4J_4SJjQ6p7txXp0RsqRxTL7t9t26UDnNaxp83JnTfjZhKZw14m21lQ9U5FI2NsN.IAVuTj2eXFxGIDpgCzkN.UUUazWfAmelH8and7lT.z.Kc9hSgsx1Ub0If5MX0cdncfMFxqnNmDadM6HVpuj685HsUHl0.CPBcLVOp.YmXHGVwEQMRNFlTepu68cGdP3GslC6tonQOCDxq5l22WWCi.GbDdDW_eg7CmHntgmjEy2ltFx4OmBsWba5sl.5p037MwL8C7XeLeFJS9xie8SpXbVSo8L7v8E2KcsYfgyoEfntYdz_NJXg7J9laXkuCA0e3DTwQrIWf5RiGK8IuAZFXJh6HJrtoTvACTW_xTYj7aB29jLDgZPma12jx8wvi_Hz.BvwxY__qSnKinO.nIZpAlDKAiJlnu_jVw2I1MY44zT0YVU2Vp69QW0z5eRIo_GXKlKJXsfti4Vz_dT6E3a.OjyPz.xjWn0p7pouqvCkbyxLs04XgMVP_b.tCbrQYnp9kk3E9ac08YYwZA9slMtPNcrZfFleuhpo4XW4LYayd.IVsXqsJga9DljPpM0DbvTF299NCKEIFmf4cr5BD0L_SWXzgz.O9I_Ky5BN9ScmOdojEIOLRPG4iSuwOONGbfuHEQ9cRVDPSfBHpyIfsBX6lpTyyzrAhAV4jldRcXvM8ABPrmUf3jtrhCOGRKbTkoZC1nNE8YQQu0Q7xfeZ7MbNGTA6w98284ro1Q8FDv0ZiLN5W4ZjS61erQ32N6o85Vtr7dwmTP._yVDn8R5Ct8xPRWX61xGaoLCYPNByQUS6iJE1CrGZz9Sl.R0WWe7jfwn9igWMirnrGo6apyoQHrKfVSIZVomTwyHbayCb6_UUAzYGHYVkot7sgXDKov1DDQ6FWSWRrXfVJc2CcWMBTFffWVgn6ixwm07SaKZYk6B1CtzVX.GwAhTO16uLz3Y2igyjfy1Sq6P8S_ltquJw2_Dth9G8NMd_rzGL9oR3Jk247U.9GvUDgcfZRstzLK7BOgFb0uTrK9FM7zD7ZRzcaR5SL2gLw3ca_hz9MNkRdeEIEr_9Re3SWGtQNATFYBmUGQn3BBVorXE23J4e8VmrPtdF_3Z4zNTQYp74hXPuVrE9FfdtfCJvkkGYpHqXSAqpoRF9Tl6jhFFRwYy7PFAz2rqAkP_QQtB8N2sEqBtqk1qfH9N40dTPRLRFQW6Kb0273V_LEXizES4ClGuh_txMN96RlDecHDeZMMVUVHauCERCXdrsd4o1Sy2ExdpRNq_gpjPd2XZP9FYvaYEoQcvIT_9Uxabvl5CJKSlJmH_ngxn2xS.w4teyZ4b7Qd.jIcXQ7FBN"};var cpo = document.createElement('script');cpo.src = '/cdn-cgi/challenge-platform/h/b/orchestrate/chl_page/v1?ray=913397109f391ff3';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, "\/10010116\/apa?__cf_chl_rt_tk=LL_USra4pEELVBc1lLtHlogV0nZg3GyMd5b3j8GopOE-1739772372-1.0.1.1-SguVga2uDQr3QlrShiATdsxkhE9_krKUE9HzbXti1cA" + window._cf_chl_opt.cOgUHash);cpo.onload = function() {history.replaceState(null, null, ogU);}}document.getElementsByTagName('head')[0].appendChild(cpo);}());</script></body></html>