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: '91338fc80f973fb0',cH: '14eLYd9xrzW.7cbBiwqfD7r2goQgRf2Za.KFq3u2M6A-1739772074-1.2.1.1-1XS4IrfVjaAFJ3GB_AmyFA0j_aKOkbCoDYAMtrIY2coBCz6VXhDZO7dqJc.qRv1N',cUPMDTk: "\/10011994\/apa?__cf_chl_tk=TfUwWFwM9aUKbvuEKNHYZopg4DyV0jP33U9_SeSJPkw-1739772074-1.0.1.1-cr.3oM_G8uT6yVSFjrePyU5UdwDzFImXapyUlYcZMQ0",cFPWv: 'b',cITimeS: '1739772074',cTTimeMs: '1000',cMTimeMs: '120000',cTplC: 0,cTplV: 5,cTplB: 'cf',cK: "",fa: "\/10011994\/apa?__cf_chl_f_tk=TfUwWFwM9aUKbvuEKNHYZopg4DyV0jP33U9_SeSJPkw-1739772074-1.0.1.1-cr.3oM_G8uT6yVSFjrePyU5UdwDzFImXapyUlYcZMQ0",md: "pl6RwSwRHEtE.VX6LJzDHyvPZhtM3Z4JhWJ3A0uT_zQ-1739772074-1.2.1.1-5orXyxg9LiRCJV2dcls_bJr91mQMRpuVILs7R6FrrRxdtRLLbOX9XAnydZ8bygBjHqoHn2TpwovovCMFkmCQqLUccVzSEqtPfZE6Yz70e1WNt9dmSA7gUSRfjS8Soxh6UcmyhbJ2dSg5epFuAkliogE51K_o47IY5G.1XWLm6MSN4ihZhBcPYfyEJrZbZ51OIjJzK4IDqmDF5x4cH9BX7Vvmp3f1LCpyPE2KpZpvRYIK_.PYGReOK2JiTOwfbAdli5S6LZbeAZb4t1mtp7KWuQp0Jz8BEl9X.vMEzfxzbxMotX2pNAcklqKwuVaxI8ifeBC9TjLFJUgEdPvVegSbno4ZeKFygF0K2aOmfxpemipGXN6CbP.kcav6ElZ7rdEhksjj7TPpDytCsGFOjWs1.d6n2D2gF1MWGMLenF_WOle1bPlfhyST_ToJn40qtJbVHLWuy7Vasl1yvHLadsmrBdycIPPpW1aKWWn5Iw.0UnozR.ilsLAya9wKHcFlUmv2pcHbEJghEaiU5BPGz98AeRWqC.Vg8BdXSOL9oEnVUTOg4QNI4mXOjygjLKz.MzKJgQFZvhyc2yR0OAWqI8E7w7lq4jZN5s7tObWu4efNWT17KSGpXPaprhhZdizNAAwBwdEdsV8Di.iTXirJpzDfPyDDOFdJFXT8beToJT3K8dndkaGTj54Mq3m.geR7X9TOWyh3aTqufyYjsUdsH6WKNskEQXZvM._vFc_koV8NC0zeUEt7ezUaHmTRq_L_W2APe8QsM3_WaBaxgYeZSHaanqRh.KQW.TY_BJWGJ0UDobAM5srr4mbhGz6A_VACwbggego6PUqSgOcSrAXHMkjkAuJCkRRYuPNTUUDZocoA5X223Llt8ymn4JVUBcYL45OeAcamnv1y3frHXwRs2WAVDVn9QsuHECNvNLtRDTbvtSMRTMQuu9WXWbRR33Q2uHx8WPMdaTjzbKKEBClDRNhXCUt7Y7Vq8gZ6.PqChViej2o3H_zpAFDhRrbmvM01GOUQz8HvnBHRYXpjlpv0owiE5Qd_P3FJ3u77Kbx5Jmg2M1MK1grAnMGllCWOX8w59nnUs7Nk6NNDlxXxwulEL77yuD20eMBDpDyBSZzzADm555d2pOLgjyKaEW5Mr2mPpyIPixDx_XJw50E8DrDLScziryqqKuqWb.la4UCQJpcXPn3pPLSce6TRfhH4RiLTZrnlD6sjkiGezBxiPBYzSUqRSjR3LNdWA1KfF7dwml2bXW5PShHvE07gtLBgFrf7uHgzObs2JzmJRNhpj6ipVAVigtbZSvgBYuV8TwzLUqAaLDO1FbUJM1cdn_9SeX4lZZKScfCXobEWtrLlHSTGTk198zHsFpkTUzNI98o0PNnEnHOXK6tkvxq3_JwHLVqGEIZs7CXD43KDFV4YW2F104yzj1JW6CFM1h_DUsNZDfOKN9d11tTPvz6q.yHHMrZH6O5YDdtwwP6I2HvYM0.5xV5euTIuh0ZGCoPM5sTupLt1fhTbbVxDFaYLNdQr1B0lKNOe8LtdxhnrNayPKpE1QlAz8cd8qeqe5Rj_9bDwQJaddbd3TJo0cjrDygFxdcRHoSD6zsGGapUGffNp2ySd6BXeTxylsaQXBXGntvDPUDzYU.C3C0ZRQ1.YW3A8oHqxazsZRhwCT2_QpspPLzV0LzE9m7Rkkf5NBPUOjMH..69kwhYcqY6.InSIkAQkjp3LPSXO4zUakEvcUXPk82bTgwWzd4JVdE7KECqzLS41NAOw_1M3wXd8qFo4b3WxD4V6rw7zdNezToQNXVLGALKagHivEwWRvLiJhxla4QyYmin7TEAP5HcRuVhRbqjOuMhDs9cJwm7j6J57UNAkgEoMC.aUVlWeZowGhon0_tsnGMAXeBk",mdrd: "KO7idvFHbkDX80eP7xHdPeQDFvS5wH8Qocb7hkfie48-1739772074-1.2.1.1-iKgF3ZHJfGYvgioda0_pO1uqhHhuanCSyW1IHoiNGn2Hxu7HUqxXVv.tDGOFr2gsgEJNQ3Du91fX2o8B3klSXdA2iUp.CJzj7rq_OyK2kBKzaQvWgwUcR4g28NmD4PGJC7tB81bAkpvANP5Em0c64SOa2hg0AcFTRzw6csSdAvG4KgOf4cjp5Zhh.MaA3cavJqUWx8a3pVYG2iLy77rFUMCn9280X2FimBiJH9KmOvM31LgE1QBrgVHOPIKz2VqT3HE9uzt8M0_F5vFdw0FKQIzQyPqVgSUkV8jYrJlV9QRjzH3H45fzSxgDgHBT.bxBSEe1V28FxqSIuO9n3lO1wUyvLshlPY56.fR1wLqb4LogecRsRRYY6cYHRxBdCAofBP9VvXIJzW.SIpO1rd4Wtgu9.oaUbvDwkuKlfktdd7_aBze12PnEM_ZU6QPm5ad_GJtLoqXr_vIdMuI4qscaTktlMnEjDxhFDlU9FN0X1gd5.CyAP_E9Ld8sKgUqxR6dsA7Ok0z9hxaLTQydqMD2e5Gl85fXvQ381SVEnoN0RyCDi5GDN_EOHQMu8iSbZ22DEj8_eEMVOeSVMSY1vqB8gyh0mdrfE8.UCgRqNyV.Ocg4890tQT3HcT3vrjD6oZErkc.yscn1BTCJrWj9_D3a7qD6SbtQU7Y1KRpw5Kj_V_tVr7WNqkxA.KXIs15z.9FEkp.da7eNTCqgy5wtaLkun3Sp90T4Of4OkjGo6xVDRQKCR7wnyi_CT21JClZj.5Eg5GTrS41MyTJDdovUFYzMCZLnZhaM5m4zXDj3SVSOmYPW1Ey9QXG9ZSPHvaJFulLPxrGdKoBmrIPUCr3QYGEw41J9Xy0GIQ24G10oXGe7SMPXdZu0gEN89kcW_fwft9nglpe5hdbYHNnsgTZdp2B5it7S7Y1_mmhVAisg1yhiKp_1wuqo6JYaGp7ayGVi7m3JodjoMdvVnO5Zl17K8_3s3qwU5FjSre9QDC_dhCax8wts1zzyCDW5zTuiTY5Le.cWrSXiYAzuFBCWvYVPT9HqJdMZ9JKQcAMSbpMiCIjL.7RBqW.4xsV323.Viq_C0iN7xLQiZ4DPDqbGn7oAcAFnTyq__uYlYAcTi9eqoLbnQx46TQcsbZc5r7svKkkMRIqsikWMKWu0AdE9KZa3gFUhg7EAbA8__XlCvT4sL3DJC9HtbJ7j.b6eXp0_vWSTnj4_VIzmUJ0qVwAZYqhl1xuXJH0zHw1LfKOXSH.5TXvbfThDRk_tGafQB_FdbH9aBcCXMXtrJv7mrvSLisCg6QJCekoIC8cW_ur539U6lMZRzDRPgTWSCcl_vFtxZszRAKHHLUdN1.iRfz2aDLiOq2GBQOtLQx4klRWzCMfadOlGW63fjwcfT5jrtCV7QIUzF8vMTOSeiNQiRCVK5ftLEueaexHmx8RdZgy0EG5YX6ItxU9IXeb4_DbEH590gX3W6rg14V4Blyvv.VPVUUWv_b5NRTKVwRQV5s_0fv1gjNGym29MbLMhPOgDtjS1KanCJz62Z8Dp8ZrIjQ98.lSJPzkOdgnQwH7E__qGvo7ImDFzW2uCsTdsOyEM7rNs0kUNVfnlxKRzQ_TiSBO5Ag83kOhLoMwVhMtUmUzxmiMu_qGe7pYKfOEqtiTqBD846U9s5aT87CvnHdSri1nzrfhNHkRcoHhsTo9FNmx8ykCFt.Nhz2o7xVjW.i7ZE_n5DUTVfmGKRFadRQ9uqwxcZyR5488YUubWeiGeqqrt6_3D1EYc1p4vFsHyXEoDFAeP1nAaYfZrzuL2WnGOpTLX5IDxyup2ViTBRr4DD3Oja2PnUD.k8sLACgjttIq5ZE1ghxPWTjskchalYc1TnDBpwL3hjI.ynHRDABXMuvv3xoWxc5JG.T3b1gEWu0tuofy1mC6tjxO3uGMHups3oHS8Tlbk9XzA4CScV7K0VJzF1JX5fO2DchlyoOtTBvJK05rCL8S2ttVS"};var cpo = document.createElement('script');cpo.src = '/cdn-cgi/challenge-platform/h/b/orchestrate/chl_page/v1?ray=91338fc80f973fb0';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, "\/10011994\/apa?__cf_chl_rt_tk=TfUwWFwM9aUKbvuEKNHYZopg4DyV0jP33U9_SeSJPkw-1739772074-1.0.1.1-cr.3oM_G8uT6yVSFjrePyU5UdwDzFImXapyUlYcZMQ0" + window._cf_chl_opt.cOgUHash);cpo.onload = function() {history.replaceState(null, null, ogU);}}document.getElementsByTagName('head')[0].appendChild(cpo);}());</script></body></html>