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: '9135199acde6ce6a',cH: 'mfakQfqo9GVrlY8f9XOBHrr4K9m5i_nB6REtzP3Zl80-1739788205-1.2.1.1-7wn84i5EgYVjc7eMFzjNq.l.ZJZFMTSr8hs_JrmL97MlvpvneOqigLqjxqIyMkUF',cUPMDTk: "\/7070\/mla?__cf_chl_tk=1kFOCMdiW_sLTsA8qJ676GbrA5KeBEm6JaIXux18wac-1739788205-1.0.1.1-QWwYeI0vRm_4hqQmKD5rFJr35EAiJ.U7jJJ08RRTKpk",cFPWv: 'b',cITimeS: '1739788205',cTTimeMs: '1000',cMTimeMs: '120000',cTplC: 0,cTplV: 5,cTplB: 'cf',cK: "",fa: "\/7070\/mla?__cf_chl_f_tk=1kFOCMdiW_sLTsA8qJ676GbrA5KeBEm6JaIXux18wac-1739788205-1.0.1.1-QWwYeI0vRm_4hqQmKD5rFJr35EAiJ.U7jJJ08RRTKpk",md: "qBDq8_G6bFMy3LacUC.tvCfdbiOQEzYc9D_MiCC7dTM-1739788205-1.2.1.1-P1T3jz4r9dnmY83CWqJHXA9O9O_N4eV1E4xH_navCd7Pmd3fcVQsTlxT7xvgTzNGv8brVE3KxrxCS1Sf4pujwVsNxc_sdQV.00azjRk24Tm7rl21N3vhH0b0jmTob1hT6peDy0rENrpSnCUmP09QEtbi_50AOKPEW6hLM5BRKbPnPh6WYyi_cLCdl2Ya9R888qm8NXA86uQffBq78zO1nNLV5CBike6Fzi.qLP9kwsLJKVAzZb3g3Ni7kclKj23oTpydEm6v0lVzJFv2GY.fvQU9Bg1NJnVeZ8rFVSKCx9q4vIxugmmL3m9g_MUnaa59GRam_HwSZuAmsIjNZcDR7XFTJpwFSYXsoTBsaJJM9D4YCNKz_RQLqWL9vGbc2sTRszTgv0fGkSMtkaHvbPX9bSZnU8ZbOOYmniHbpFCCVOGMoGTX.v8b.EqpuwRrFV2B1p7IuQPvPB_T6zcfLvFOhw9g7cmN_9xJi1gb1_lZ_0KS_7NAVz5PV_AewcD86Yfw9iG6ZiVdiAXoatqb.0vJ3GGKKvJ6hJ1.fFZxA48YrDxRpewT1wiK0BJ2gVL3PiSrL3fsdBtV81VtsfPiRWcdRAMx3NL.aBAkcaL7v1EfSNRHOOL.x.Z4Ab2mdHQkCxAXxwL5SKkQxU8YGRGuE.TAvxOlOJHnpnLcmX.HgCwKLYRc5vNYPt6wc1eB2uh3uJDcL3J3_.ALRJth24zhXwPAQsJ5MkwV5Bb2nJBkZuLt638ezEcK6wQRnHnw_J3douBle0TKlPM2R9X9hh9saZpsAV9psbVwQGVyqS1KuvbySRZUAy.DZrMUQ3KCyIkwA_iD28GVb0qaM6ci79OovT06gHHH26cTqxZE1iZPjNX6PFHo0L9ej35dcQdLbHdRkj8sEO0QYOFWioLlqvRoKhkAwiTy729Q3y9EqAmleK4wScfNpyUkT8GuSQy.2qfN5FWzuP1dtTitYgODvr1MIH8h0LFFTlvyOrsfNE.t0KmJ0rjiiPOaYXIqWnFtyhW0I376qt.tVbkWeRZlqSkfaYpjgUOS7OTO06pim20lNE8ta_A7blHrl17xAnA9prK25h64ZHAQSDbLj_yq5lVTK_.ZOgsGLEMnFBAivtGdB5qOgSGPZLvdwvPvCb7IjeLhVfUTMsobpueDDU0RcHZb5rRG3nf5_jGiKZs4u5itx6QFC8KvWkhKIS4h4rONV_oKZ4yw1qjBvh9j1w_UfpKAPZO297S5dfLeusouEPy_omN6gsAWFplQazgh35im.mtbaS0hMT0DzecghsJfOnOu1330hgm.GllTwt4IiNeT3L9mLBIyedddpLN0zw9tm271amBxz3QCj7ppGMWlRJF2iwlVqcM5bOymN8kQ1LajSWtXriTt4r.scmTqC8CU1fzT0bNHCeMhBf_a4iZlYo43JmDD4bfgcSESHVNirigzCDMHrKbFv8wHy1yt8wMLHALbqsbX8.Em1Xaidg8hqksvgml7gM9ZyfJixvx7J60bSXq0x8ZntjYo8PvPkrlw92iyJLUdzAWN1bGYESgKkUDU_64z53Fo4FOoyXwvryMURByrej0AwLoNQgqWej1p1CjguULhqWgigfUiWXBnnQobMYoMeguGFsAGB.ZKVpK8yss1jI4oLUtxsoXb6eIUWPLIKUuvhWMp48HCTYdrHOv8WQw01iCk.4bAhyN_jkMJUh3Uhhh4TMXXTdJpgzB8Un3oOqLgAreRF3_7J5YXs0W3RExnChuATGE5mW7MZnwCpa_aubIow_nSEa8l2AcxgJpcuzZ6F1j2eMp0v4xJs8UulAGpaXqTLDHcx9oHSEmwi.EgeGetCp.coj6h1sI_t4Nh8fZPlrJjFNJxurI.BrCCLZAPVg",mdrd: "sLHTMgQEF7Hi0UuKvg0t1y6xhd00z6BXMHgqCCQdH5M-1739788205-1.2.1.1-X9o0m.9KKhYu7yeDiSwkNMJcXKtPwnmETCuucvniI4MwQmqggPYmBqc84Uk5.UG7Mti.KaK9YQO2Eccbt1qqfiGO2okfvcYGmXfhfdzVsKizoPwbI_dAjof.5eGXoT8Z_ukpLKmWmK__b_Vj5tUA8Zzy4M2wPC4opFa5RJEpRelvALSVvpf0g6eJbv6ZDPygHU8hHLuN6Bi87nmGdeNV9vObyIVnof6ngXjiqi5uwytPrdvawW_2nInDgIZENNNFbVzDvwxBruioW6D9x1z2dcHDqu6f0VmMsHFRFYHqbkolgONKSENtHzsy.igzOdMEXPWAUkad2C4vi1A.jAjEsEAcN3x_jegD9tYb7BHYUt5gRIJdsMjEFSIVSUDjHr_1iKINi2WLbL0cm4x.FrcihpoiRIzxUKSWePokwtdU0NaxupiMYHRZ6gHMx_65aafyfHaSij0GCYtQKs1Zgztpm3OLOsXKp675c1cBbPqZHDOdTUcOaGqk.NdF6N5FkNAlLmHH6nVR1PpCw4MgZ3Eub.9i0BhByeIE9fQI.rXEHkVKWibB6.E.IRcrCvw.lwR3tBAHUK8zskQqP_bmXlEHdHbIda7Y0YfTt26lWI14ABLf.Wqb.rKJmkRtEOFuJ7a.wVVR1BIO4ozN_PJlgcbOwgrZuhXhBxljXQK.K2ubqCFhCxr31TS.1jqOXbaPOwsJwBLfulIcnV_YCNOnuDm8zcx5ps1E7cYWJJvEYCX3xfrBAE0AMa_ddipf99qfImAv_o8wAPliXwFuU6b6xjFgOB7fvFbyclHw1XYDDvpFdqeuSFphQd0xEexwn20QAv9KURQCwdmViHLiqcI_K6wdbAnZZDQLbBemwqFZ9adWLx4CEU7iLtsWykYxLHUU649jV6ACPov.iqfhHpTua8WSbcF3S8XIwtwwjwxZHnJcMumbXKCy.Ni3VWyp8UydkUtuggC3Yjio7lC3eTXk0YwYn_LYzYTJ7fFxzhKnBQMMl9kE6.zjQWzFe3oXYe27GPcEsglipdgyn.iUdslXAJmef0kUdsd.FQmRHTYW.zC2c6J6XmQ8m9N_53FYLTURDLfsQ4J_4ZjI_SAqhptv7fQG1AT0kV8kYLHvoMMPvXIbWijwabZNn4a1Nq7CtFwJRWrNoXzC93L4Xw_tVw94Ugzyt9nUvfE3bFA_1QVxPMBkrIOBgLrUjbwyVgwWBMd0qiEEobdod71SNLt9.H5GjNz2DCLWRjjNEfaiG4Jbr1WnYpm1Jp1b3CGg5xnnFM5qBzVbK53ikcv_E8Y60oMKXJscSpdaPGUKVujkPhhXTa.Weyghwu7fMs3ZV6UkC7pjUSTZRuBxLCwU7NRe63P7DGqzK2Iwj5tJfbDt6tpNfz0OzPRHMMM_clNkOoqj_P1EoDB6EhZja_ZLcUbw4_yr6v0RSugh_W55MJ9ySG_D.CJIO3z189DkPCOEdEkyZDjS3xmAgsFw_PJ0Voy5Lzra5n1fCc9Tjwpi63IaQxXsFFdLjPw5.wL7ngcFB9X74qphkUr5UvkxxmLWDYSlGtSF8eZXihvxKFcYnCs6tvV_3UFE162bPWPVXeYiaGD3CVKYAaxdtwN2RR2piK83xOeI9TBCo_fQRL9b1Y_l.XJZdmXOEnA5p1ys3_QYLPJZgQqp_HL8qHi0tx1GkNpM9M2AEFvPKDpmEzXOov7h.iHqZea6zdnkPfdlxNHgxDBfkHYW1o30hm9bAqVzhw4mbE2QrO13YM5jrQmErQoWWdts3aoA3RLrR8Bwm3U8kUXfmPXvCi63_P42XC3KsKQo0dqT38ERXI6X6NuM4h9BHItrSYNU83X9oBJttrO6fWcO5A5iW6RPnVAhdbe7ZIaJqR2Iegb24hvtspcgqjehimxFUojSJfxJ.gbtBajGvOZCc4Xvg4yVMcuBkslIzrEr6.50cdn4vq57HEhdnWAa0kkiocGvHHnVlUMJki7Kw3vAXrXmF54A"};var cpo = document.createElement('script');cpo.src = '/cdn-cgi/challenge-platform/h/b/orchestrate/chl_page/v1?ray=9135199acde6ce6a';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, "\/7070\/mla?__cf_chl_rt_tk=1kFOCMdiW_sLTsA8qJ676GbrA5KeBEm6JaIXux18wac-1739788205-1.0.1.1-QWwYeI0vRm_4hqQmKD5rFJr35EAiJ.U7jJJ08RRTKpk" + window._cf_chl_opt.cOgUHash);cpo.onload = function() {history.replaceState(null, null, ogU);}}document.getElementsByTagName('head')[0].appendChild(cpo);}());</script></body></html>