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: '91358be5ff76ab5c',cH: 'b4ZlySFPoOaz3froMm.05jEK0FUR5OsFB6TdX7mUjls-1739792886-1.2.1.1-8tEznR3X9OC__fj5aMADzcxrCuKekd0Xweu7oOPLaxlYo2D3vRmGnw19qnr9oUh3',cUPMDTk: "\/10000932\/mla?__cf_chl_tk=4XBqgfYjSrGDkAlO4nx2ZumiO8VSNo5dtWJDtClni64-1739792886-1.0.1.1-VV9nFs2t4Z3pwlsB5P3323qdwgrHiOdavth0KpMNM8o",cFPWv: 'b',cITimeS: '1739792886',cTTimeMs: '1000',cMTimeMs: '120000',cTplC: 0,cTplV: 5,cTplB: 'cf',cK: "",fa: "\/10000932\/mla?__cf_chl_f_tk=4XBqgfYjSrGDkAlO4nx2ZumiO8VSNo5dtWJDtClni64-1739792886-1.0.1.1-VV9nFs2t4Z3pwlsB5P3323qdwgrHiOdavth0KpMNM8o",md: "p21s4JQRsZYt3regrwxQMfwwWw7BRYHisBSpeOJ.xQM-1739792886-1.2.1.1-wiQRjQtgIGR7CAgPlQ_aawLxns2SQVGT2Z0Em25EX1wXbpGKxSOyNVyul7KyqxSjTD4icVE09lp_9_.42HEhFXqu5MXQz12YiuurweD1pV.CQb5oj7U8W_0oG0TJnNuyu3VaA1a5nH6SPGOTS6.GkmI3yLaDdkM2kMlQ323R8zGamuTy5XEWqX7_PtVdQQyWqgVteGhq8.ma0L4Hn2o5j5jbDmUQ99IHTbVaHh2xcJqe_KLVmcfXegVRRgvgJUyBKnHoWQMPBz8bWpDah08TiHRW3cRq8z4VLhc1AgboT0CM9Ff7B9BMbA87c5N8TMfjsvQBA7o5ZEdhGeYXG8SsYT415K8QEShyAWw.DfBkdf9sxpRfni0OAWvqlqbBBihm6HEwZ_ydGDOcqhrNUvhGVpkjdz8zow06dT7YEGcvBjP2AywHI7rXkPu7VZ2v3839LNEo6Q1vUGGUCGSzHZjgdLYclQJFKhCC_ZFzwoTtsWiRsP8pXCT_QgPoQoX9mCLnNTo_jMMp7ab1aWMW0Y9W.vSEQMLWMTg1pMBZxaNEFOCGyo6KxdAaqyo09CTZdCfA3_tQEBF3vhxKTJ4SaH9sxo5JsLkvPZavexmcydsXL7NuWbeQpU6KX8ROipRstXmvMvYBuggEVk4qY3JhwZ8jGu7zSNOgFyIZxPvBoa0nDXTxnLCqIluRLzc7OG5dG5uHAmGE.yc7wPLdtlQqZb_FgU7iDj_S90c_xsoawnzudldMSD94amjPc8ZSh14Ey.SYwh2os9g4dvNVvoBu7JTZTbNRgEtKYF2UPJtkZCR_XD0_TeeH_DSBKc7WCGBOGbWSRlHj6QuIV0m5idmfh9rvxj1bdmtv4.TIG8hfiLCDnjq1ai7Mf5BOUfFoooZEUZ31tHgdl99BtEpBBjgjIyjpHhReWHw6kb_N1i5WLRcrf4IuI467.XmBNab.8C3rsxpS1ldngID2BvcU1mFXK0ZizJfL6lK2QcgAAp.06blsmbmCZtVdoJKv.lzmbuvcQqH95da2q1Jyf6gxC67RNgTPvl2XkIlj9_Xd9SXNvrF4oEClLg5nnLjpIWFu_bnw6kigHy14VXrkW4e.5AgMkONv22A_MEnMfHdJmGYh4WNkd.W.L8hdAcvYJuTu613tdL2BWWa3Z_6mfy3v7GjxQewMJW4q115gbGfWNooV4YfyLEHTfQETeRGtMhOMI.b1oJCudavzHGOL4pwElLkjgUw72V81ASxWtW6hPt2reiUQclcF4fc0mh1BtyTCqUFbNoHKg766HCdAJiK6ScPlTc7HMutVROCA5ucLnKUbZC5soWFnL_54hcdBjQnhpUUYTZefWuE4rW6Zh1SNKdZDmVHwKmzTdz.k4HHi69jgGIYp4wzZ_PWXMgispe6fBIZTU0xCaIq0r6tYYWYXtZYBOr2A.Jwo.41FlG2fLuCD9cv6parXEeVJ8SA6yr5Q50gVUdS7UBXbQFUyjanVe8UtJumYf4xmPITYmLNahr.O5XWkzgBeCOuZu4I0LD4c19CtThtxm0sAhUv6gJ_.KSoOWydFWAvw5dEwUfbioYJeN9q_rXLTzbwbg6WIDI5l1UcTC2OWN_Z5KgSGMjgb9JMrc_TFFFuz0zwoU1BGHflQlwe6g1KJgCR1x1g4R28NYsgwx2de_HR0xK9wbMPG3W8b3irPKacQXX8U6Tr5XDUPmjPsl5JA_4LZAgTSrcxJo2JdnRarQ8Wm3j5N3QAYLHRh.ZKP52Wi8_0x0aKpp8vQ2Gr__I3ZIzd.spV5jmFYHWEgSwlgOj.IB1DUh.popzFpBChcT6lhSAn9fe.Rj4PEbK8tMb_pPXbztmtczb0AEhD0xBHMOqLgirStoM7zqdIc94NAMROwOoj17edGdKnmQ4xq7xM",mdrd: "JG6mrJ26Ib.bgznMp7IQOivsmZEk4VcaQkthX3dqzQI-1739792886-1.2.1.1-3iYndmfMVL0yevQkFLhxddZ5CsBG3svn0i6_aILYKLnirbRcB0OtuXl2BYsp_aqP7V4_AVTD.jVc_WFn9G0JMC_vQJUUQ2QBdS0jv0PqpboyA_AQtboRFg.goe09H7YhyLJ12WBujd.wSrIZWunkHOUOCSY3g25Msk6hBBkRlvswEhEGPHsUKWSX.a2yGNN.avAmBFYY.rbRgqdNKHX676tNVnCOEg3qkSy53UmpFWhZDxQgLX0H9xqOa258pLKp72qAD5ak6sDhylk_SqxKK.6y9HP2ba_tGRNSv9Yl2q9TIXlxTccjzZxHzoVCbmevi.HMjE.o3ILV2St.gS4QV9Erx2G0N8iNRDky82umz_NGWeAKm3L7tvWi6xU6tr9mDYY9TYqPNkdHn.vDoBSBFmGSzFHfm4r.K51NVY.ai9oPqwg8ruog2rKDKrbpMbD8YrhBuhgJqoICG1ts4WwibEkcap9ARRddvgzrpZa7KhTJ0tEgXP8s3PPmkK2pYiIIH0W_WEsAG6ruyeXbxZEgoUY9adv55U840zQy8KMQMc4iVQrtTa0xtEpr4HWjRxRT04VWlH6on1tlYDzbj4afCF_Y7Ih90QQ6gM_ndEJ1xTFtn_mtUEEINvy.oZhpoIzn0fU0NVNO1i_5zomMeDSubCadltRF0eg1pl22sgN988YJVyGYo04EFCZ2N4zMHQa0e3O2kNKnS0ZdvuIHKJD5ylV5y4gJN5MIllb9jlv4I22odSbZBZaMRCDXdh_GHIoe0E8.mK3ReNRYtNUKZ7pYwLLZ6NdERW1NamNNiEtVYbzq99fZhvTummclYqxo.iXnI4BIEQDjYHmm4mlRkY.w9rQ.j1IR9qembl3pAFqN7cw8ulqKryUJqsIfi50McclgPxnSQX4gst2GvPtQ8bLtyjQXRXQe8MIpnmD._dyUir.VueOatoXuRl2s6BZDz6Qa_eEQ6C2SirJqwSEPAHIhaHV1uCf7P71OVqeRDl5QUtavcbaywG33Q5ZN7tiV3S5jDw4qWJLjplhJOhjKCPABlFr3FyQLwAgaonwGqwVK_GaDLLb6s7aoEhu9kPzGCEzcuPKXPup_HgfHqx3ObkZxvtMZtsMBypxsRBMsPi4ZbYUeoU6SsUnBXvtrR.Y9W9aEMTPdyPEHXLN6BlkSKuB1gx3PlZ1alyCNQOT3fFh6XWWrzP6.IRjszkTyYKUWbxk1bnZHiLh_2WbxgkilgHtcKn6yBwJWRC53ACyX3wQqYlfmFUIfZVwAciwswpFfV4BkKtjJdQZWUwMDwCXY_lnqWj_ngotE20XJsSxfeojDe7CByZ7QpLEYDuRMXE2i0xP69EiTdg3xrIuJ3iktBq08ApXfEMU.8zUq8PJnXXrcQ_7PxPAla4qItaV9.2W8nQ2ES4zz7uj4QypHHF9FsR3OmK0UDBbfzWLg2yR2lyfh0tGdyc74lZUDQ7INNNhM0CaXp1l9ac8eTUWgvdoOip_4qa.BGrQ0Ia1ncGM9kFdESrYcqVB9fTKC8JjnC6cmRTboYF2Xh1agKhQJKzafwaPzGFzgO7ee6aHxKXbUWh9obSLWGG_A2nYMGrHZW2Td.X5Ijn16dcqYQ6Kr8wZK8LMgny2WyUvbLub4MKupCubccJ6CyNnZGOj60pPPV4vZu0Q6396MFHMGfk_1FhHqezVWJRHozFzmPd6vcMVwQQjNm10RypNPzD0l9UPHYDK5PDpMyXnRCwMJhfY.9HJemeJ.53wf.xmMZOJAADmaVBDfLu1ZVTEYfD5thhwpTJatQiZ2JTH4obCGOKZIIwVnAwXJATBfSszuNuiB.hnuyK3b2mNHjSM6yy3xKYAWzwI5caWTynrn3_Tu9iPwJVX1KH6965wduh73ra0Cg09DkA4peyeaxmh2q1rJZRaj4HniUJLcZAOnJ9pm5II0WJo40WIduV0u2BepKTyBHDXnkyYTLLZ01cpY.91qGXc21g6YmHOL"};var cpo = document.createElement('script');cpo.src = '/cdn-cgi/challenge-platform/h/b/orchestrate/chl_page/v1?ray=91358be5ff76ab5c';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, "\/10000932\/mla?__cf_chl_rt_tk=4XBqgfYjSrGDkAlO4nx2ZumiO8VSNo5dtWJDtClni64-1739792886-1.0.1.1-VV9nFs2t4Z3pwlsB5P3323qdwgrHiOdavth0KpMNM8o" + window._cf_chl_opt.cOgUHash);cpo.onload = function() {history.replaceState(null, null, ogU);}}document.getElementsByTagName('head')[0].appendChild(cpo);}());</script></body></html>