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: '9134fae14be5fd2e',cH: 'xOnhWrGHdGAgdpzMHmZ1vn3Orkt7A161xabiBsxskVM-1739786946-1.2.1.1-jiJ.DlUIaXETwdOCd6onZlqjtQPOqJqoTSRa4sCaTHYQdHiDdubGw..J0y7YkHlG',cUPMDTk: "\/1898\/apa?__cf_chl_tk=JOPuOam4FLooExFBhWSHUUZtBkkYY32cOTOaHVBjwJk-1739786946-1.0.1.1-WZpopZ4rJ4TvWp9o.77KvhEE5bEVdSXCdu3k4T8NdCQ",cFPWv: 'b',cITimeS: '1739786946',cTTimeMs: '1000',cMTimeMs: '120000',cTplC: 0,cTplV: 5,cTplB: 'cf',cK: "",fa: "\/1898\/apa?__cf_chl_f_tk=JOPuOam4FLooExFBhWSHUUZtBkkYY32cOTOaHVBjwJk-1739786946-1.0.1.1-WZpopZ4rJ4TvWp9o.77KvhEE5bEVdSXCdu3k4T8NdCQ",md: "jMPkUhtaj9XJ3KLaPPor_gA2HF1vQzaLl45KT7wJOEI-1739786946-1.2.1.1-BB.SAqi7ledIfw137kSDaXBNnWCdhuZvTPoJ8KOKKe6VaIyI4WfFubVMTPFVBiwEEWvJeXpmK2MVWpgHT8DZxkqPpJ_Jc_4M.iizQj3p7VxNYypBVW3Scs3E3XhMENIC06PRvhmcPDzlEmb4dHoH1U3S.7jlIOy4TmnXD.gxxXxUseoLEHnOfdvswfmjNS9S1Yb3JfnKtbCzexSuC0K_y5APxmH2JliEfwZkeciJqnsbP9IgkHxt9U28ADZMkQDK2lKUc8_G9sTreR4LT_xjg8IWMvsyv5nmIeZFaufxMn1gGMPow9Qs8BcwFRk_LzuNZ3nF7CAcPEwgdznXWqNf43qDwMeNfH_09v0qWfK_XeRcEQck.oxT.UGTDCAeVVPn23MKFDzSavtvHPLinxAauvD_PV3nHdk4SvCUBL7bq2Lokbzos5eN9BMc0BwwmyFerMxumsadR.55KGuoUxaQRn.1CQ5ViRLNh4DdEIhNbksf_lNWd2KpSzwDsTS2EZgLeHo7Ypv.X2YePWmXkLWBRd48E4v4A_0C.wdPZfA4fabn1Tqwa4TFlc6EYQ6O.TmFW98.sdAWzW1W69.tGRA6TppCK9kbM_7vbwE2mT0neHeEbBrjtmAz2nCa.0QkFTBU84ANdTbPKFrQANhu.TBsuWrvhMTTef8bgIItHqAPOjpQrABI4Sw1kp1rAa8tROm765CVe.eMjMsHiEdV5VKuUUHcCXmJ_PO6DFa6qastXPFA4ck2B4TcWXo6_UDxv5sYPA28GBjysYmW1pZ59LtpZtDkjlwUAT1hdaIuGbqzMVnTUTxNSJFpOgxQiBmVlSHJHhmJy_ahuN2td3X_IfdYKeKI9MNpvwcT5yp9sgbkSPCRVcTVHXSzPVs23aHDeNIT7wKZcxYkjbhlHaslCBuNfzG9x6KaQAyLLWvr13MnKjkYAZdTal4VjmvMiOYXB0DJVXnsyGjdi.YKpsekzYO1f.jytAiMac7KeRAMXm3t1ktw90cKHo3kHdHJURWJJhz8vTYuFsT2ce6wTY4JVhMYg8rTlIGEAxUAySpGa3xDc3BZOTVFO2yf_44.B.mqyKCgZg2zh1IJv2NUjzKEERU0at4Sc_HEkHpGzjWq6PhMb9kPBv9LbNEru0WwKz4Sg9LwBCOkvt33Scp4aDr67fc_Z8P7XfXXiWsZqvieC.OS2fBCuzykR632hfzig_nuFXrLMV5atJ3Rj3Fh1CEWUggQMzfQF5pLr19lH94_53ysHTosd7z_CzB4jmpsNsRZ7ez4j4qalPnVE80sg1XgRJKz3RhuG4l7cJ7MERQ.t2gPdQIK5.OQ2hBTzVvQ4fdbco3scSH0HZdjWv1gBK92IeN6MpuVMgoEZlAi7Pi66NjyOtv0uodODLfFvZb1Ee1H6I.sD.HU30shKZHweuFxjNcKuP_05dVJNzPSACfjz9Oo.JFeVHUpMOnqywG99Ljv5NhtQe_PAelqDl4sE3BezcxOroykA._iwAkkPPgA_2b07CJYcBC7MFS3HNMrSb1KKrtI7j9Uen17DXBVb6XcSof6UnS3Lgfdd3NZGYgpiaC5iWLUdLXgaN9HTLe2RyAA7szgaYqSuX9Iz7_NhbuiqjOZNlPTRWeKfMYEIb.Ks69UdypsjHEpcakMKFtZjyDTyXx_YeABzrYQLAXqA.nt1SJwwfoWGxsxKeYsmPIh8zjgnZZ523t_.vYNQuOox7nNqEs1K4.zoTUzBE1Pfx3.O0a4MOBdGgO.WiBxrRlSkjW85obMsP7tIkQAylkRwSp2wW2dfSh.SSfz7awD08vMlQTpiGcYwdZkgTFiNdzsYNYGhLfO3XKdOaSQy7tKCWc6DiZUFOpCD6lYsNp2ro5HmHLKYg",mdrd: "OoCOfw1xAroCaB62qbgyLYhe5Q2I9ER2MtsoTAmNo7k-1739786946-1.2.1.1-Za.N7glPrN6TOp3r2ZvcAib0wfqh4lqY7f_Gtn0YjFq15lqj9t7.f9iTkOLwFYFdkRMTA8wkvAHxt4k1rLsucvJ8H8OaYUllo8lgNlN8o9wRKfrKcd7uh9YK9CA8gEDOFPFYsQ8jrUfVxFs6ySqXLDOM9hEbD08xt3NZPQ42dVEHY2piWpApgp1HG5pxiEVCj88CWDM7HKNkma7lrjS9jpyhzAAMIkB3Pm0kB1Dof4K1MSN1XbuscUNhqWcLsT0gam1sc2GFbr1zTtb8DOklrKLq9XQWNn7qZ7acO7w3LXvBOm90O3ufiJa0WPmbnGfsMDpwx99ajZ2Cq_J6BdBhdOOSxCvleduMbS_UMM3eCvuYSiqGVXaxllbXnRo8eL8qo7Fbep8Th1Q78WypleoKrtglxwFfaNZ7xv4koFfY_snImireoL7ZJ_PI6WYAeR4Mjmio2KclDg5MUbBFqTUQ.CEi8T_LqmnUv1CSkPblOOMV.MX_kjnn6NPdtYnOgp87Plsv9ZlIXGvXv2UUhgt.LyP2.9Io.lDmQSQKYvpUjBmn2pHbNYgbXLw5.d00kp3jQZnyHztvZ4UczksK0dhHmwEMiVlG4nOTZNo.MpH0Qw8..IOLv1YCcaLvg5_cpD.qVadp17PbfLz_jm9JEcN2ld7zv3fH_2rgKUirS0_aTxzsBpxiFgcGyU6pm7x5Tew55JsCOaRMgSHq6WwCH75MtPlYsRiW0b1A6fQAWcCSXFOydSoy2n5eEDGzOgbG.Nloc.8XzKQDwCURgNYz90tQ_SX7H1HW00FFm58yyBEOFVv1FJVplC_rQrH9s5Q2BtEyPb1uCzNjbJEBKhiWfL_mppbIkezSw4avFTqf1OEYBfRifL_ai2kXtqGg6y6G5fPLI4wbd9MO1xlJtn7HJKmC95Kvg5mVW6X63BOQtPjaPcXnjeC1gDM.saaIEkEhc9POMbqCVGwJBU0SLaCZp6BU6cB886M0DqMDQDBx.XroYpX0_D2sATYhr2_.nUc83Zg8FCz0u2pPfXGNicHZ3rETgaWJfhcWEPCHxDauoLeYrZKfn5vGqHfqSi8R5JVNUGo8JixuWLQCwqrsBMUlAOEXt.K9gc0vCtuf9rGEMoCdVNovBpA3sE.uGvF.ynjOx8IkBsjoPkr7Yyf297ZzyigAPMrKdmfnUNYEznd5WgMa1_eL2cxmBFcyFjAmCXa4tqqoQUWCLhijqNwgBGjdE2WVlaRe1pPvdDIkVl.iRDThay9Bi0h58SvYx2NDes_VhF9sLvEwUFOSGdc_LSHTEnu2OewKPdlQxl6_JhL6.Ao1kudYhLrvKyEfOT.nCQboagW9MNzVXKW34z8Q.ip0xrHI4CGCSNSyeLJPIt8iuIxetYcMTCeLICDNrKILG7QKzMACfgC4do3NK3.WAhqIyW2krk1nnBpaj6UyR7YzUdbfRKZqa2Shp5oGgL8ZrpuzeOSCq1El72uBt3KxPVMtYGWWxRFVhAZSGgJNd2RaRPd3X5fMuDkWW50uyh3FYm5OaC.Ap_H3u5taurk.VQnNEWk4itS5gfGX9F_TtRo.MpG13jSnDWH7qJ6LvuvaFmrZcuxDAqNrqbnBV1.0.zx4ADrULndvEcP_fK.TlKprO2P_o16eZg9W1Tnxtt908EOMVSV547fapW03g4wuyk8IQHnUSYVv8etxsNswJjNw60qP0FBJ.VRxf87UUQmLmVR8R7ShpCx9Rl51tA_HaIwQAVi4P6vnk.UYUbSM7ticmjFkTQaYIbV5w8Nnq3k6yp9e92g7M78k3yILvtTYapEbTnGp3TaoKG4D3h4Ih9Ar.ypWy6FSadb4v8IP0.0NVdxdFzC4E61M6MVWw0o_EtX.x0ZdCNNyxpbb4xLGoB0BpvJcCYbXUh5deJzziofr8gzw4trLVc6MvtyMTucWihCkI.MXAIAzbquQ8Q1YXe2D_VfHT7Ea1_EAL0xcKykINtWwC5Fh"};var cpo = document.createElement('script');cpo.src = '/cdn-cgi/challenge-platform/h/b/orchestrate/chl_page/v1?ray=9134fae14be5fd2e';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, "\/1898\/apa?__cf_chl_rt_tk=JOPuOam4FLooExFBhWSHUUZtBkkYY32cOTOaHVBjwJk-1739786946-1.0.1.1-WZpopZ4rJ4TvWp9o.77KvhEE5bEVdSXCdu3k4T8NdCQ" + window._cf_chl_opt.cOgUHash);cpo.onload = function() {history.replaceState(null, null, ogU);}}document.getElementsByTagName('head')[0].appendChild(cpo);}());</script></body></html>