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: '91353e673de381aa',cH: 'wAqjB7IKEZv.dG2HnUJw1gN0ios_yE8EgWurUVXMj9w-1739789712-1.2.1.1-bXa1s_670mMHc5eXTG6ydNlEgxHVOmGPj52ejpupbYwx1jUNePe7QyCyNMWe2raA',cUPMDTk: "\/9996814\/apa?__cf_chl_tk=lF.STcJxNn5wljoRe685d6IWt.IWzRb5kuGx0jOR8Mc-1739789712-1.0.1.1-UuZz3HY0dzrrC3W8XpEcm4_nxh0.7r6c6UKIO_GWCeM",cFPWv: 'b',cITimeS: '1739789712',cTTimeMs: '1000',cMTimeMs: '120000',cTplC: 0,cTplV: 5,cTplB: 'cf',cK: "",fa: "\/9996814\/apa?__cf_chl_f_tk=lF.STcJxNn5wljoRe685d6IWt.IWzRb5kuGx0jOR8Mc-1739789712-1.0.1.1-UuZz3HY0dzrrC3W8XpEcm4_nxh0.7r6c6UKIO_GWCeM",md: "JWdrjxyIzICb3NtcpZTTTcVEaQBNTlYI9ngZQxRJWX4-1739789712-1.2.1.1-KFt6rABkP3jbanxff9j7xhOWKEnAAMB4yO60LdPyuoUaw5Hrbl2cBpEF1_QxXNgTQ0agT.gccX0b5MNQHjs.d1MatXbItkQjYbxzfw_yFtvcTkTBvxAu4LZX_H2s7laBfcslNHWCDztxgP2KQKfi.Xly0B5X7I3TZ37sw.suDoyhTr3GQeIJezEjXnZCRXuRrEl3SWlAraDn29_LQh4iZenIyrKqybOdCFokQl5gN1vQVd.nn8PNtgf0iSRhdyWuTtvWmhNZsCktKBvwZd47o.OPNCMJP22VCmrcJ4JnTmchxUP_vPPQFFRuXz_RegjFtmK8wcyh9uEfu.i77NMyknAq3on3NGwK959dz9vIA4i3NDO.1nTkVOK0STRPFyUTE9QAAYL7tRJEehBkChCvFasjoy9g8PEh6hdGDKm5jgvuqUKzqDI0vHfXR94RLBdJiLi1ScIheMKukfEi7TL2nE4yfzeuvJ5Z4pyjYYq5CJTvbOj4HO7l5yWXWzr6MaIrCFTUFmCwl9_MCRQslkT0r6JS28frZ0syICRBHoRV8hVX5gB8D1zxS6V_S87skLhK5bgFi7r671_cFTDTLsF3XdjnhvH4srurAnFS0B.f0XHswfrJdj_ol1n3AFB4cmKTHfaQNmZNOHekD8MHthjnExsJFUa_rH.pGPu1LdPjB9pN6S6ff8cQFRYtHrO3nobMHwIfEQvesBG_Jb5XuEx07xDlyMPy30IoTx1i7WY0DqWiFPUHjLJJQ2frGFzF3Nyi84OcyOJ5mz7k3s7hmxWmbEJyl7ehgYXEuk4farHSxoTbKBOR2FjdAeC6N.m8h5K5GtME9w3TRBnD_UFW11AzgVX83KnUcNnCSeoQWDAFiaea3LMP7JvLJkakiv_fYBxywnNYCVB.3EkGvkLFUVAI1V0YCGdTkPgSnaQjHQFd1xVNv6bhWy3UbfIrnOk9L.oKqoSrncqms.KIjTzZk9KM1Aj9mJlktd2xfB1NtAZMClH7knH0pfgjA8dlkOixUSnr1O1iRGwayXz087anuPH4WdSiN0FesIt.WFAsGyo7NyKufGN1lbpiJpVSKCTxGqI.2tSvLWCnTS7jDNiv..JtxA2NHfQ.AgEWjs5djtXxXJjUxxGC0PO20VfWeEAAUQsv8Nbd9JflZr2ifHgAI7dBXK9SIFbgS_WjY5M1Slf89g95Esx5qN9VUl7HQ7.tcd7pRzqFocxmtWLBNHtR4u7dOV7sKT4fdPxqHqPUf.HuZ46eNI52MI145v2JVPaWD_0zp1ovP__tixWQDBd1DUXzyn_Y6zz7utzpg8_G90MtyyLh4abN4H_wYBawcyf2xeKhy9whnPUfkLtTv7GYtwU9d3l4gDEZgSuN_cucmfX7PzaZhKXEwtGsDTrTowRom09NWlf4YykFe6hbRZ6DaiWdBMVYRDTv6B4yT4OQ81Eamz3sDGlKIwQ4c426Ttuns5a.2erFYQTN9QuU4PXq4AMLnCLnRNeaKpLiFOymES3RdCARUofTl15lTOGaBw8N_5urQIpemplrSYXAk58YPrBbJXO169AM8mDcZcvEkB4cjpv6VwCrYSwI_0L1tjKKmhRyXRpUjvbFB6vgWzBwtc3DL14RjTdlwgxcDCUkkfxtKWEBx_KYiOci9dXMlyqTM5YQGmZZaMylbXaQLiYpllQQK0yWjvFN99qBLowCULHxJygUvV6wEDVfysQJBrGcJSEOgcQx.ISeKUGQFFmybWbVReAjQCmPN68_EgEObi7s5hc20gKowdXvxa37LBE9QbYu734iwYHul6_NoRJnuqiGQUEcBh1rcKN.D5ENaxB67M.vgYw0.vZKYMbJ1Z0IEY0lcuzJsjg4wyD8W555VVw5qWoWAhDeS63Sc4M4tZosX78",mdrd: "jx4gVAEWgqn3HnBr0JVvQbRZenBRHf_RTd_XfTkcS8I-1739789712-1.2.1.1-hv3kD1EkVp9RTA9.sUw3n6K7eHmO8sXhLZ.Wd2igBZOVVQ_OeFCrqdlgLCqz3ZpvdC.KjbWubMW7S9iqWO7if6Ljb7WigTbgv55F7ozLcn8.J2pNJv7JvIjuFMdquPRHtJW69dKLuIFqm3LbEa9uNF8OPTHB2AzuJWXaSaEblYqD3EUpkV6sVq7SYEfjKboi_op7f2IuKrDGEFk2YJkm4Bt8Zg1m8RNxH9ZucPJshuLsxdRtdzs2f5D3wi5LJHZ4O3tjtHISeQ60rgUOOIr3NioJViBAfSMhJe_gG2fZXQKtyODJyOymCiRoczib5.cl.9ifgOBVlWsYVFh6xoXQb8P2.9c_Ve7echqo7CD.8BX0fMAbCfl1aqbilToetfS9sEjjUk_YzrTOgiQAQ3FBcXatO1lTTe6NEDTEKSUgbKDvFxxQXCe7_Eolhx8PQ5xZ24_snDm2OQ_C7uOsQ5XA8a26YjFPMkyG_KhyMwB_HxbfKXYCzWkjHxZpSmu0z04sVWvTeJWZ7a8L.rQRy.nC_ZVGVDtaSVrGAcfK8WYX7zIUzIq2kPYBRVZ3xWerEc8iDUhb_cve49gWvO2vLjMQTKKGFNHK3wOSVvgWLRzjUnnJ0iU2ybtEX.LGggKCAD9OYg9_UOgs7uNPcW7zEtvrpocvOuCOxFMVLgF28FEUeyi2xuzs5l.nqMBJGU7wBdVcQK8ZeglEUa12tmHTQY50sfCMjp4XxfuMXo962kYsjO8wd_Wc5qjIWnMu6UUwkZaivprErp9vysi6ptzMU7xAA8Ajbqdvony1vOCHMO57QM81Pp4Lv9HUIIJtRQ7zQ82jxs7Lus5jF1cLBxJ7IIX9BkvjYTDSR2Gd5lLghbU0so8o_WBNLXl_4pxYY9AaaGTwbetBTFQC.AOLy1CI.qZa25bPgsyfDkZdST8MAmb0ZFGfkXIyesfS1MVbw5jAsZngYLVEKQlElWzFu0LP1ehW3aAPSZpoLplWHrxiO9ALSaP46IcPO.l4l6DF1ZSfStipyxIp.mNNMt8zRKrRLPT9a8bmKbJ8EX5DXTsaWyjHbNknMljp0x2BWVsNqSnBiInwnFbEm26pOkMFU_36FlVlL1akBS6GYAEtp__.KDf3pasPTEQ16I9vjbJ8UeHQuaPkCLN8GkdxTUqLNAjlK.vITTm7XYVwvaqMCenvAabtkuvvt60Iz3u98xa.8CZ3amS8h6wrVrnbWdx4XTt73jJMGZ1wBOIpq7zfthPes6Cy.CdxePbZowt4ElL6Dv8iq84uowjeq1kna5L2k0MfAQ0dGa7LSGHiM7WIzNEIjHqgEv3WDjJdG_BfIlki5SI33S3NN.loafPRmY.oeZA0tuh3EyyKFWX1jf2JMrAVFuSAXVDzmvkNJ4SlXS29WTjPXfHV54GbMsXsgA6cTTYlNtOqSIsybvd1t5gve7mvk.bMbuRNR2cCAaOg0zf26dtO7BgtjzqlYntIEQJvY5IbH10fqLYZo1_j33cylVlVA5cxXUW4bmnh1HvIDIhrLcdYy5eRmIzrPVaIhXk5XPgi2dUrsqqJaQZe26ZQt0PnPBUE17_7eNf9Gmgn9NIpeC59JLM4HmQpqVDVZuS9CqOuQKJdw3EnbMtEZd.5ac48EfyhbJYy4J5aqvdoL0qDRTPpumFUdzq5G.9SXtSDPkpLgUzlsZdsfxQzt.1UQ8NiKKENIcGhZj6_QXWLRFyWk2ingxA9ruY.yhMlCJaycERQ_URLJyMz63gOG6Xr1fL4NJ5Iek8UHUTtPc5MyndA4cL2LJnih6TyhX96klU8ElZMSznW6MZiIJFhTKgUCSJWatrrPY2IjnJpkwFOZ9HVn5qVlc4.wjR4QwgQO0lDcIBApvbCL7sW9hL1UPIuQx4IIm0wxH0KsfbyLW7o.PVOpdakGzUapFjKyki5XdI78iSN9pCQ_6PhDHAzvETVqCNxum_4YRbmMPpCTdTPRRHhOEmDi24_"};var cpo = document.createElement('script');cpo.src = '/cdn-cgi/challenge-platform/h/b/orchestrate/chl_page/v1?ray=91353e673de381aa';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, "\/9996814\/apa?__cf_chl_rt_tk=lF.STcJxNn5wljoRe685d6IWt.IWzRb5kuGx0jOR8Mc-1739789712-1.0.1.1-UuZz3HY0dzrrC3W8XpEcm4_nxh0.7r6c6UKIO_GWCeM" + window._cf_chl_opt.cOgUHash);cpo.onload = function() {history.replaceState(null, null, ogU);}}document.getElementsByTagName('head')[0].appendChild(cpo);}());</script></body></html>