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: '9136685ac83c3ff0',cH: 'VufOoWYHnN4VBZ18Ik44paRZeFImrn9odMwjIToBMjM-1739801916-1.2.1.1-EiTOZwAx_sgUI.cu8RQtLIXkwxriqjDrJQ9Onyprqz_d7RDldPmWCPeqqIfgSGan',cUPMDTk: "\/11008\/apa?__cf_chl_tk=B.AlSU6lnySDnlXUQQ76Duz1nICiuA8B34HsTDSKU0k-1739801916-1.0.1.1-YugxKF3kUKps1GMgkJX3FmeIe.1ktd.kf0UNFGTSoSY",cFPWv: 'g',cITimeS: '1739801916',cTTimeMs: '1000',cMTimeMs: '120000',cTplC: 0,cTplV: 5,cTplB: 'cf',cK: "",fa: "\/11008\/apa?__cf_chl_f_tk=B.AlSU6lnySDnlXUQQ76Duz1nICiuA8B34HsTDSKU0k-1739801916-1.0.1.1-YugxKF3kUKps1GMgkJX3FmeIe.1ktd.kf0UNFGTSoSY",md: "PokemcNzHsWQBIrgontxNIdqpjOw5y9zfPnYt7pFzes-1739801916-1.2.1.1-15Qms3yIECbR.lahOMzarZiZAexhTMBhDE_XgwR5IfjytVON.nEAMrFFeBluNfvhai2Ywrsq_YFAMb94dIeNK_u5D2SzNHKIrHrNfUjvQzunjuC07e39.wQ8CibmI4MFSvVILVc20W2sWlamXNlb2UnYpfGI.cKn7jzJvovI3A3wppwDhsZ15CxY9AE.jxtvI7TkTmMur0Fb3LX1XtY6lN6vCZLBDHUysJieScYeE8EW8ihAbJEYCGLZ9udumAqMvC3fhk4cHRU0fJ31_mN1Gw7e7_.OnLL9R9DzAUi8qmtO1izbyCggBr5bEKWsxP7maBXnHFY.gJpx9HT26j06haOVolDb1YbrkX5bawU9mnp7KjQ5PT0ioYA3NKVZiIfZx8EG.WCmKI2XRNuVMPlip0sQ_l3mXzdwNOk2nXyl6faxlC31prQEH4DnstDzjyDkXLkDlYVJsP_rWO48s.Hsj.UqvSfNnaKYXBBOEKe59.VLW8yPVZBqymn3vKbsCniCXfIRYW5._tErBrzJTwLSBawZNUUj8EzcDsQdryFqwdxHpBl9KZhh9YyOeu3KP1unAkgYbVffrzwnCK.93CTp2Mpn.UN4Uf4vFuKe8KhQdrfBVtqxV.HAVTS1.QAWcqKjLZspiZjKmdLqmqPDKzUTHbymNK9KAEWud91mbWjH7v6.eZPyEoXS1UPF9kWO.wHDnY7VT3UpxgTICIzpvFfRoKNzzf_qyEZmPKbCCS0Mfu2FopNgYuV204yub3f83IWFNwez_qFyb1WdtbsCQZfOI6z6MXP0ejWtNuzKbHsIglLNVU.Y3LTlVtiGnqAXiVbRdtQmw.x9QUpg83AKNoBnZ998DQPM5W0_9DWuLDp5l94tu27AYo.8gK7KopVQYRKPQxWFkeLsvQifZzgQSSL3DdbSzJ8eNPZ_4xjjVcUKTn78WkVuRdgJi4vt5ZPszDzy9apDckFLA_lXm2KEBd5OJPZsUtn6OCFvwS.rJXrQpTqcQd1W2asphkPZOtDLeMnu.EyJM9IIXlwNt15b0Klv76u8fw1Wk9NfuKiiOVRVSfbr1PoLAzzE1rjxnz1QczJbHoDf4T.NC2fw0LrvZ0Eehv5mNgDQcLwjLJSV4V7awIkuQOhiB.bua8p2tnj5HXgDnmTS_GjEVtSX3h8Q8_D74XrB7iw8zoG6PEvw_aRlyNeM_soT5DgkbdrVGFgWXVhAbSPyAXCtvghQt7eyosnBj9DADTW1a7X_tTTXNINK4sHVzJxSaMGUSNIpFE9p2FCuHFlynPQYK24MN2bVQO_egnY7Xd2YBKiS4HOiT9dZtetj5r22Bami6nDfvrNz_soozeRdh3HO9sJH3Wyjn47KR5Z11x2.vWQv1nAEznkOe8Kh43S.i8opytz_v.5VruQOiOTE_ZzzL6PoXxY.vfUOt3UFqxo51b1Xv72hRuGiMt2cIjqaV36qk.JJk8rBYJnIuXz_YDu1dwt2VQBTA_wi.p3NKIPSuOzy5C7Pog2WqaEEkdST_cgwZgPSbWEzHL89IXZiSYNpyBMVQeMvedG2SMnhAns5V0w3CCFKnY6NIY0CLAcBjwMy14c0m4PgFgmv._ibMIKR1vijCccIfKvtQjkbk_ryHSrAOEymfdTeNhdk0.xO9p0avvExYS_Q43kdja74vK5Eq9JG.AjSPmjl6voXf71vGtl3r26hucMYW9Lm5pLRZcLAaKZpfJhdu5xZl4c2fkcHbptbGNOpGj9vQy4miBKMeOeNulrPmJ8pbgsGvMuebOZsbUuXTMdNty7Jc287LC7wXgX6N_L0lylrUzFsYhl0PnSZumniDpbIYp931A5LTWHxZSaai7ua7tubktJxwipTW_8.AqY.TRcxyWpmcz0IG8WLnNqzSJ3rQa4",mdrd: "fM6E2gw.hG3IQIVjNZNIcIaD17qyyIrYgL7.BOSQ_TE-1739801916-1.2.1.1-DMs2fdgeNayPqHahSQ7YM_SDjPLTB6Xd.osuR5yB0WeAbiP370R5Pt5qChqKfjipPTe.ZCc.GM1KXDTvbJBhRVk2rSGM3kAAzVhI87SFHF9rbRMGXM1oa.bdZxECjMeRpi6MJebuGOTephKYd1fsZ6bHfgt1LCpUhcf5XeyrVx5zRWgLdVwZhZ5UJLzi20vATwtOx_VqpYMjeaUR6Hr1kDBLRz9ipV7Ptci4ujavhumRyQaMZ5w9qL8JfN_.8WFS8CGmaxqWXWKHqsSSrqwfdmBT7zIOY2bwj.UDSYM.8xfY.lkwRASzUoY0PSAJPutB6GekiuMUu47KeMpPmCNQ8Fi9o4lerGZupz98.a6oQSVdhgMeMCJhh9Yi5AMnyI25YodmsEPSAPDneAJoDvBsguz3VK71LWiZfenSsxq38u3xe3UYBvjz0J4q0uCT_4xmfuvIw03d5c5Cn.iqJ8rl.dqte9zLFGTfzdW1iFhGZTYCNpjfcNXm3u92wh7jhw0FGkfy_YLl5wvgz5kEXQULlUiNiPsyE4Y2TjtQApgaiaTA96x_ImC9Gvyw9NE5igI6CthB0FqWk498Xcix5yzLowEizoDNercgzRzOHp9SQadZfbWk2gEIcExInfJ0poj.VgjBSAnuWLrT4jVlSDXYg56f5SB9h2hEm6TymPMKak86OlZGdvJlpIdsCUI0W4lvuo7Gdvk8Zh9vt0c4Jqvu2G2VjVYUhnEgBU5FbN3n2E5S7KzsKj8MXU1X715COioNfCO8E_3J3D_I5GRSxR23W1IBXf19Op37_vOpQ9he2xvpxtWuAv5TqZ6p1j36OR3QYaC5UxAoFZjX5b91oj4e86FxjR1L6NmLCwxxWQgaCVqpdcvG0efkiwBXLdrfaTMswQtfIUitiG5X0ITPFCr6Q67pCWimkH3KQHa_R_pmvL3k0CdR7Qsz6qyoeBrjqCpfLfWzb4Rnal9SuSnPGkB1bHGGNXER.nc4XWLGRaEDwi9KsCQNgN248Lg.bo127QdY2IOrYxhg04dhRwAhPswPknopkGFZ049UdpZjVZgfCCungb63zqN6Khu5dXtGHCv0IKiEfsdjQXld_xtXMBAJA_O5T9T6gHLnFMRavYHGNkKaG_QhGYOw774KX_aP61KbGTeXS05Tw0Ahcafbu7i9rruA216K2TG1K6GwdspNfovT6di8yqXpcbbUleoXxwfGgfWkdGp5P9Znelt1hMeaVxjNguVGI8ZEorf3Ujpc2YpqfqpXMFRBOD0ziDeW7GOo7gqsTXBU.YIHvPJGTzzpE9mzk27gWB9PvkgO06rlS5mvg5cCWoj_5aqq9EUnQqx2JfiMWyjuIFphWHObNW6oZHODGBtQuzI.5vdOieYuthHzV1dh7TYeAbM8QFbQvUOzKZHIl.ro_7lkLlGe5vdGdafM0rUalnDu8eGfKr6AcXrZWaEZ0_FUW5.rrvGFwB_p762wqyBFlVWYdV8U8unWLmvV84bZ6iPjpCTAZ699iVggtPyVFoq9PKWjHewHjI7_dmOZFj0OTK_IUl0Nf8TuVR8BRwN.F728ppQW2T9kak9aornl2yEmZp45C_65A4R.93EeANwkzlDX0qoZt5av7Yt3H5f4Crx_ovfHv3KEwnMn14R.Un11ksX8ikmdwCyeYAvREwnE0fhGocbfO5jWGk4HNydeINxQd92O8V8t0eFKDrLDDH5ISUW3AJ3PvJ0.Go1pAa0E45MkFAAFbpIeFvQ_nryLqxI7sFoJQbeSiUzSNr42mbvh255hn48BXD_ood6mymFfRzGsHjuJMYHHIgARdFX..9_5W9gHNzWnByCXD3lYgeRytY5WKdDdCVtJDXbsfOYII9dCCbFxy6cPeKVYjNIglqYFRN8YmnKJ_VwXKgJhSZ_xQoyy1UBd3mDWumIBSzVG.o7B.cRzb4sT1IfniZI2Abq7sFqVyhTApcXoCEEStZPWa3t4DkyQt4UGflv0DOJQfir4CSiXsiU.vQ"};var cpo = document.createElement('script');cpo.src = '/cdn-cgi/challenge-platform/h/g/orchestrate/chl_page/v1?ray=9136685ac83c3ff0';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, "\/11008\/apa?__cf_chl_rt_tk=B.AlSU6lnySDnlXUQQ76Duz1nICiuA8B34HsTDSKU0k-1739801916-1.0.1.1-YugxKF3kUKps1GMgkJX3FmeIe.1ktd.kf0UNFGTSoSY" + window._cf_chl_opt.cOgUHash);cpo.onload = function() {history.replaceState(null, null, ogU);}}document.getElementsByTagName('head')[0].appendChild(cpo);}());</script></body></html>