CINXE.COM

Just a moment...

<!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,PHN2ZyB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciIHdpZHRoPSIzMiIgaGVpZ2h0PSIzMiIgZmlsbD0ibm9uZSI+PHBhdGggZmlsbD0iI0IyMEYwMyIgZD0iTTE2IDNhMTMgMTMgMCAxIDAgMTMgMTNBMTMuMDE1IDEzLjAxNSAwIDAgMCAxNiAzbTAgMjRhMTEgMTEgMCAxIDEgMTEtMTEgMTEuMDEgMTEuMDEgMCAwIDEtMTEgMTEiLz48cGF0aCBmaWxsPSIjQjIwRjAzIiBkPSJNMTcuMDM4IDE4LjYxNUgxNC44N0wxNC41NjMgOS41aDIuNzgzem0tMS4wODQgMS40MjdxLjY2IDAgMS4wNTcuMzg4LjQwNy4zODkuNDA3Ljk5NCAwIC41OTYtLjQwNy45ODQtLjM5Ny4zOS0xLjA1Ny4zODktLjY1IDAtMS4wNTYtLjM4OS0uMzk4LS4zODktLjM5OC0uOTg0IDAtLjU5Ny4zOTgtLjk4NS40MDYtLjM5NyAxLjA1Ni0uMzk3Ii8+PC9zdmc+);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="390"></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: 'managed',cRay: '92768efd6a89a036',cH: 'ohcDZMBAxr37pjIqy1TSHHsrkcRBITXahi_IVxKQRl4-1743158942-1.2.1.1-GXHhQHh2.n.nq9Ex8fh.K.r5fsEYtf1TJmSxdeSagF_EA12743RPKy8hGgmCmbmo',cUPMDTk: "\/5738\/harvard?__cf_chl_tk=RV9xDyiN_3qd0zd4c6zUI2l1Rcc8roXUw9YyySI_BXc-1743158942-1.0.1.1-IR5Mnwt.W1PnvGSJGUFNZROgg5M9UmGXEDIoN7D48bA",cFPWv: 'b',cITimeS: '1743158942',cTTimeMs: '1000',cMTimeMs: '390000',cTplC: 0,cTplV: 5,cTplB: 'cf',cK: "",fa: "\/5738\/harvard?__cf_chl_f_tk=RV9xDyiN_3qd0zd4c6zUI2l1Rcc8roXUw9YyySI_BXc-1743158942-1.0.1.1-IR5Mnwt.W1PnvGSJGUFNZROgg5M9UmGXEDIoN7D48bA",md: "JZiACt0KBnHOkb3TcCtu7B5DGI4eC2Ns_wHwWTeFNNc-1743158942-1.2.1.1-DdDOx2B6OC4iJre4vkjRzceVxPSJGjKtPGCL9R9oucYX5SAQN4LhJq0p3odp7RTJzn1bT6T2wLcuUgnyA0yIhDqL1VhrwFAOENibVju59vyI0YAC4bVMssyAGkYPgEKYP0yBZoQ8WjictPx52.IhHk5DhbDylaqLvH8P5ukgwCTann25OpB.8Hujo1Wzmv4SZqH7k5_eNl7fluDxJW3DoWuYjZs0mBd0ieBRuM8O78bSmJ7ONTa5PAQgg4wfGDSavK0oUuDqZuiChUURE0ipQVU5QTuUpm0SziX2HeX3_WGasIdGu.yHJKhRbpNU1BKt3KdCdrCjilg3_exWeXiXRzAOoEOsJl_pufwhdu74CDcOWc8qE7OKbwBjJhG5MQSKAuvu0ZiE1JXACyfUTs8Irqd6IFfk.dNpjWHcZyniNscqTxL5hXv3i4a.uTRSIosCi81ZC7oBoqaJJYTwJZzPrT_pW2Kxpq4Zuf2FM7PuGKkE8HatFe1_M2u.0KXushE84UfmrD4f9S3HRDMnoVRrGiscaRg0vsJRtX1BPOBYtqe7nA0.qt0UF31FKSQaiMN0FqsvY0ZU4YWErXVlYh55mLxeMSmrUIz_Rz.W2V5FQMwN.CDMm3NYwC_JjVqeDwpvf_CVB9jmZWkMm9N5mLTrrUoX532Uas8GOLAgu2zQ0BlQ1NU484JOJ8OrzvPQ7M_4GcZdV71L2E_R3UNGujDTRYkMl4hMjtTb5vAOCp_DO9Gm4BctzV85PqUzNcan0uvoRc91XGazacgMimXAXWhDdjN4jWaJgCeW9wbfuEbOAV.mKSe8gvX27MZli.bm82paGV8Bjjvm0vXh91r6e_LkbXTcot9MYvAxsqQsvnUwLIUCcT0Mt9f9ZTd01GEfQ7NB3qAZvqUcR.tVsgMrrUw51H1XiEriDRVaPagUJZfHHY.uBOwBPle1cCDVXRU15AFoVFNJdo_woBPBVnsNBtQ4ywpwLbD_bzRwPXKht4ii.EqtmASQRf0rt56.83cRL1grFtg3Ih8Vj.hmQUd4pkgRL2qsoNyn45Mz0kGoNZqhtCcnHwumyNccZnO3w__kvKLDHRjfjUm8sBAKcF.6NPpiHP3krI_L17vRa_8Ox_edzsVKxhSa8Xv2eb.aCgsUTqC7CAVYrtSU8ttMgCPTVR0Z4Mz.JA5A6sCjD2KD7IvzvhTdZkT9uBWHUhfIungqELEqIliqwjRDQYU1w0GwXYOa7Q",mdrd: "K3IRcWeYfX01yU2Dy9zszteslBJgnvBK.zmzCcvreAY-1743158942-1.2.1.1-S2woU4q2d_hr.Hf0heBlTF9fyFjX3AgN5L..1zkIgeNqpco2dVmxYszdAAcqK1ggUBwJm2kRYYc1ECb1uQHGLtqMDAWh55dYHev0Ac28QaLdo7OVbowvruMVjhH868q_77Xts83kVUbh3gO8FrLS4Mt.bUr1WC3akwywyfEaqsFgYF_cvpKr.FsbN2SPopCN20FVPvzP85jEYWTbmiqTokiCNYgcaaOUkPSsLUSeS.yy22ciKtwgURUebpv8kR86cOMd_qXsCMKs6nE97vA_gFxBqZUuY54OjUOHAYGxtGjaTtj3nPtWWsSIYt0_fRBgSnV2Bb27xEO6QoH5iWbpT6mKJzcEQa39ohlL_gCZ7zI4YQx8HmvDZeiWKA5i.m1gdSemJLKz52ux0DOpN_PhLAT58gZpuJqPPZXnnA4r8.ZPrUck2l9CxLF8Vybu6GUaoF8sVrx_SaAcEBlIbmFkuPpk3NJ3d73XePBDuFHoyPbUgO8C8K43pNf57wCMQc5zJvsfd3rSVxlKu3U2XQUwO8c3Jn1Owjtk6mXdXCTGo1U0U_d6wM3iksgJYu_TnDpfHksV5NQealV7b5M0Wu7DWC6x2o6ypTMwQQFLZnM9Acwh5pXiOB7sgCbP3mdqhK0UjnM.IZBrBXwAntuQzWrcM4c1YpRqR1LtjZz10sbTn7XJLvAy0dIMejE9YJLAM26w1Qltoz0vzUrPFmy_D2U2Z_5XF8mG9UFnERZcRPz13e7wh1mlOSzlFD9j.TV6_M__soodrKLzDKcAGZiI33a1gSmFMnQI20v5Ivq5HQ7Rvx6MS8fRa4inimwwF0HXTljdtpN8RrpcTMEfoIE851ttwXWHr_VexyYREIWnTaWh9XmkiA280EPnWOkoQLI_QrB0FgPlBo2KslmyrzNwV0ynOFNLZ2RB0CfuoaQhpYO89D2JSQeIg2RlJhwkQMVQCsQ.WvprzTkGckqBuCHksgH7y.m3w9rthEE2xFZp2igwW6BAZcevUmaCOaDxIoSNS7DxBNrzRbtCZkFJ8NX9GBOo7QKsKQtnXcZHVSLWJLlVQBIMmARoyLRMUtSVa8vPV26Ao3AfvgB4mWb6dzXpHmDb2fq0zRJlWOjxpGylqtVza0LnCVVn61bRdh2caof102No0qbkRpGXcvDMMNbgtMxAq79mcZ.gaterww8uRXwngOWGT6Q_JzOSdDkB.jQcBk60O7P8ASZIK.xlclP5mznNlqdaYzXGh1HbSEw2eIbz3yu3AKLZZP3d1kD0BcoTDVUhyAzJFIUhBNkOA8yDLQ8RL9Iwj418RxpPnceKthjyPMDZcSoflW2LlPEitE.WgIraq4lwFTSG91q.lOIpJb7.R7qij9sz_hGy3Kk_PCASwZxc2LqCl7woKCBfbz_uPWsvC6c3ueRnar.lDId5eqH9kU.Qaod8pbvXdy0i4WSuL4qjeer9wkvtkfVK2O5iPjFwDwLskWXnTU1iQbo6_SWBMSB6lbRFum7q.HqfAf_ymDolbXwBwRPdmDDuHNt_1jdwPfqG6IKFyNZPX47KR7XIMn11NWVeZNaxv6FAikVK1ZlPGfB5v2AkZwGRNThXnJQLl_df2Fz0QIZOkgiKYLsgFR1FB4c9Rzm2WXioD3Nj6F4DZ89vIDoOeihNaeYyz1RaqJdZajBunPJgq3a0iy7XiLBnikXy8rDsrD0hLLGMyE4iaEdLogK4MYPiggLhSl2ssU_jGghF7WRHo4hcresgxBPJzyq4BQm_1bq6fTMu24vHDjJeU_vgmdslm_DDdo487l3qb7erM5eyd3mmKgnom5To6i3BcviVxZm00Rp891eVIREI18dvkII05L0ZwR.0W3eKModob3Vi9pD2fm2wJxPAP9_J8fPzXtJzjsxSa.Znr2UB6W8TY5TlW1ftiTL4utxXie8pJ1w.sJxl4hUonkpq0BD7uBoxqG2wIskLiQ.2TbWKGxJS5OlKPyZfC9E3B7eGbbl9P3WMw_j443Gwen36os7OEFH5yy48gVOafBCUpkFnyJMYqwHTSafbUpEevBqYtn2_CIPK80wl6xZlNBWi1m1VCqAit5d3y4tZvE8"};var cpo = document.createElement('script');cpo.src = '/cdn-cgi/challenge-platform/h/b/orchestrate/chl_page/v1?ray=92768efd6a89a036';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, "\/5738\/harvard?__cf_chl_rt_tk=RV9xDyiN_3qd0zd4c6zUI2l1Rcc8roXUw9YyySI_BXc-1743158942-1.0.1.1-IR5Mnwt.W1PnvGSJGUFNZROgg5M9UmGXEDIoN7D48bA" + window._cf_chl_opt.cOgUHash);cpo.onload = function() {history.replaceState(null, null, ogU);}}document.getElementsByTagName('head')[0].appendChild(cpo);}());</script></body></html>