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: '9134a8925d07ce55',cH: 'MvSs7DpTJLAthRQ3Rk.jk0SlJRzSoir11Rl05YHaoro-1739783575-1.2.1.1-RJp6jF3wNmKsqsQb.FwlReeBaoJ0Mq8FaN8hGvm9i5QcARB3_tjoaHUO2170r2bb',cUPMDTk: "\/14227\/apa?__cf_chl_tk=A3KCUTK2dn0EI8z85GxzviO6du7XBIib6Uoc9FIJM1w-1739783575-1.0.1.1-xc0gZaKYrbp8a0KomhBY1KzFk58k7vabRlnsGYyu_II",cFPWv: 'b',cITimeS: '1739783575',cTTimeMs: '1000',cMTimeMs: '120000',cTplC: 0,cTplV: 5,cTplB: 'cf',cK: "",fa: "\/14227\/apa?__cf_chl_f_tk=A3KCUTK2dn0EI8z85GxzviO6du7XBIib6Uoc9FIJM1w-1739783575-1.0.1.1-xc0gZaKYrbp8a0KomhBY1KzFk58k7vabRlnsGYyu_II",md: "8WXTdyT6f9UHxB72xBouS52WeTZXPirsSi_pggHyc_A-1739783575-1.2.1.1-ckHB6YrGXMJ9I2aeLuzZpysGwyjUe0iGETEoPS0V8cc4BDv7Q7pFPNc5406wg18Axqes3JhOFPm6rd6hBAauoUQdrd9GuNKEYLkNYdwffFF9B6dzwgSM2iq4AClbIr9ivYQO13xHeaN6ulbusMqBZqVLeNSR4QYQqp5tP8GP7Yizj3ntmSZovo5rURUPzaqnG0Wwca9vIzYU39vbLgj_6VFQjhT0XDFYy93.ZzDFy5Lb3O7nuk6_ro5XevkcsunYPgdwBiPmwPZUUJQBqCio6Ieq.k1r0eO7mGl02AkQAPDKbRKrZ1RPOpNUbSkycDfTFA1oFWeADNbzx8shAxJ6HA86zwl._JBREiPFz9Anhs8.cHKX0UTge4FjScbofS_jt5QtwbrhbzmROgMWtII6.P4XUPuRmUU8EGr4Uhjs4KtR97M4XtDAh7sABwAFm6q2Y29lWpB513h16RHVG.3U7zmyftWJbTANgonG0ORzfqYDCXr.0nwC1_H2T.7k_YHcvsMEzT8mNjts2uTJUqZPmtRzzaES7bOJWV4Iylh3xelI.XNw1ElSaqC1NbFJJb0VlEcR8Nz7QDBHd0Jo8oRxBwOFhAuzlOAu6LLXNs_ITFVuNKiUrdDBcYmgY4sSPeyFHIRHzTADtzmiiukTInZf7QtWW01YYeZoJuOR1I9DwOQSuXQQm1kPkGch3n9KFyNReQrCl1BqywR8yYjbIOjNLGLtBs46l._NL38GzeGDy_By_6Np399H1s1x5CeWj3Bm1bkXUsU99tAMXFx3mVTk2bP1MKDf55ktzyEd8IVedqiLrfsk4u7F.OKdiU5xo0jVTYzZgMbGEMV4yjmLBapoJY6BC.lE.CVIX84RSJf0UMPcO9oEcfLuzD2nvXvHkrDP3VLJ8qYyZp8q21g0trzEMfzZZd7tkqUZhQAwP3_JbJk9lQcl8.g7t0gkx3ippr82i2oO6G5TNblb.NPyMobBoEw8hUEWyQvqlt6ArN1Od0q_9TGHNhqCvQEu.3iA5wrs.fJ077DQcbxvQKfXlOowUZ.JUtPYfqu8DP1r2C1LjjKLew6j.rH3F1FsVpFVqIuWxZqzCbswgPY.ZlaVBxgo0eIRtWwwS4qqHHB_l0sCJX4L7GMR9MVrlD7o07M6x1YlAzB_r8jbBDVD9kaF7t3RNcaqPc22tmb4Rv8erI6brYX1r18z48ivS20Zq5uGYtwmL.Y6aGWvbAORhmZi_OSpb0VtLAdyAWbATN626w3y5D_TY3SA9MNcKGsoHnwCKGKKXdatHBZDNajzN40ysQV7xU9K9KF2wuaIY9plCG7Gl27WlckU4JOaqVc4pk2NJ89yBaGg_5kSqUWIXMkX1FpxvWxcEVI1c8oODKGZmDMWCrMOZxrvnSuovfCrB8Zog8AO2U6u6JUFqY5WRxudBdsFPETK.9.5JpUe9E3A9Zbfm1Z6Xr1JYeBqb0XHRmdtMtyHllk3Myc114yn.Rqk3pIBmHUjTv2fyC6yDPmiJxVofrBYYSFULBsmV6CVMZcx2N9W_aUF1qGpl3fREeZ38lIHE310JIEvH3CYYLLWUMrYd1CcQsLsO8d_CKa52JooVYhkTGwT7JD1qyJuaP.y8zR6OiezlxcycDq9yj583FWaz2fE.tgkOd2lNLOWEBgbAi6xemQ6FkqAjdkEMmQ4ELNwooaOoLxf_IsGWRzxbKXzUsiq2raP2_1jWWCmbfesSwsDIiCv0X9OEdOTFkY3NCCVvjR0atx4LrZL4YdudtvXRUhDxZhcRTfWFBCQQAuH3SZ31Kq11eN2D6qLETSiqJcVtyFNuNmUNYN.L5MPA6f647FVOTt4FExnUfSrunaZlgt4CtLXcmnnvA1nR7EGXI6y3BFMSl9u.iMfjLRn6TTmKYI",mdrd: "gc8gRBh0xXcGgmKPVbG8kShfVuE37bKD2_fBSkTWGEo-1739783575-1.2.1.1-WOOpEIy8jdQvsESw8Is_KL6LQots3zJaBJvyzLfSkjBVtsSw6HJA4Zmdx64NxJYi7gcoSksU2acIOE8dLwbonrBRHCHw7mektOCyj84LUEuDFnQEqimZRzneLov_rEuXb2TpwQQAkyJptgKzxNeIa.obPuneVpSiC7GPv8QrLKUE392jn0mynQ2kucIUk1ajMlpwHPbkbkY7z8QhE0RGL.i756tbJQJUG8ZWAl_jcd_ulHukSIvk6GRmHrl77cGRe969.uGOvHEQDIG9E1IWv9XVUoSeYIGxdsFj2WxE0c6vWsHl0fmYJM4_g5Jcsxs55bs3yYy3dtp7S4YfW9FmulkCFj7nUSxskQa5HMit6DtCE6LDAx.c_ZiTaPFlW49Q_amngfyXAkSSmh2jft.ryDCe68TjqJJJOU9GGePZOMiT3kJGt7Oxiv1UrovJDOUrzk_uwV_M2tN_bilJN0ztVjpCYwuVKzOfVof1qsEpGRVleHM4MqzEHQuaSHIZf9pB3TMjuffY_iAh2TBKT783EIpz8A5CVYSObNbAvoHdu.sEMnBQF8ZG8_nSULIKeX6wKszJ5RDphkPXAosIX_fnvrzRvg.PBXKsvegXsq75uJMkqSAtjr.9Iy745EfJP83frGFPI6YS8F2uf647E7epuegGgmwXFY2sZ0.Vd3FvZ6NSuz6qf6baDra2phtrrt15PsCCcHkgdPMLC6LWqvKW8.j880QT3QUhqXtwtMAg8q5sYC.UVP3GGEH_k.z5oRkMVbqeO2JONyxv_c2TBk0jLih8mOuMXqWq3nWhU3lIMue9ZI_g_ST44_k3HAc_T8qTXEQkNs1h62o.aNojSmRUILF3OYFazpfsVjVQiY1g7ttmdamDacXw33trEtE0.LsrPPe1AvGxBqHTBpGvXGdd4pD29g9g49x3KMLf3QaehChaeKI_oWzJRhAbZbourBaHp4y9KlMz6a5DaScluJwuWCq5KSkAmk.Pz0VgUN2gHNhHLreUfsf52KqgyMsL1sj.4DPX39KoKWjjtVI79R2sssrzjynmxR6q8gnKmvEmIKNijJg90L6tC1GWr1V7_sI2FTKC7ggiESBFgyp6RqkVuVFNLJNlIIHpNmvnkgE3VKM3zDFLWGp82nef1Ef4g2o0zR4hkmbqJshWHU0hYolF9RCc9_FonAmmWJxMJnNCcPiifiPHn3s_f6uxHQ8F6ZXfZOkRLbSAwtOo6pt1E4ECosb4xt41QCIV_oaZzcvhgQqQgP7jMpbiPQVrM6zhenwjcN2nSfwsqqF4noyvxOU8qRAUHrmAASJdXrV4E1vG0vn6rVAbkoGQgdf4w3j68nizJaEXLgLEWaW6TdQTGYVmzaKK8kAYAmm67tl2rgbmo3jl6Kqu7GR99BBenBYgL0EhlCH1jFThh_g62yzoe6v2uO9gXByjZO4s4XR.6lDPwZRvkjN.cHH0yCXicw3Ob9kejX5VETlhBrVhH9vhGcAIYmfNUB6UitLRvZMUO_FXS82uNi6AZuctydfz3ZAdjBXT.ZOkBwjIQxu2QYFiECFiBNeuJk5KAIPkUyMkz_E4Kw_Ew4S_A3RWjR79U3GmiUW3ZADIx7UsgRqCVfN91.vQQxgV6A.SAb_YUbS4DO.T5wVapNKkDHHo.GEAtKoLW3Pqghd3HlVNR0qciLL7OSxeqXQGhJU4GoMMzpqgRMnf4P1jTkx2zT6_ZQJ9eKNPQkFuaRv_jLKqKoN6LhGegcH.xMspkfxTMNOis05scu0wdz1xrnZ4IN6hCOHi6NG7vbGQ4JK4JNV3Qi9KjJafKmcmQHFK9.380ZASgQy29WBsSEHqG6e6n6OmAp657OFO1ktVDm3fXQH7n_.S8PRnirm4sgszE0uXTbKftYaQvR2F.j3aBMa_ZmBek_mc.GpI.VzNsHGbsYJN2Xd2Yis2PuSRGWFn64qbr6nLyKTGMhAVRbsZfG2TjGUK4q1.GnicEfLg53FUn.dN4hILxV4F0.XC9Q"};var cpo = document.createElement('script');cpo.src = '/cdn-cgi/challenge-platform/h/b/orchestrate/chl_page/v1?ray=9134a8925d07ce55';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, "\/14227\/apa?__cf_chl_rt_tk=A3KCUTK2dn0EI8z85GxzviO6du7XBIib6Uoc9FIJM1w-1739783575-1.0.1.1-xc0gZaKYrbp8a0KomhBY1KzFk58k7vabRlnsGYyu_II" + window._cf_chl_opt.cOgUHash);cpo.onload = function() {history.replaceState(null, null, ogU);}}document.getElementsByTagName('head')[0].appendChild(cpo);}());</script></body></html>