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: '9134b7e0fdcd8965',cH: 'AxkoOWoqpuhhmB16h_8VVEYw95eE8wJWlubCaL0I80E-1739784202-1.2.1.1-KEhzobH5k6wZlQTQqIhMpJ52hEpqjGidgIeujvkg13TpDGt6ChHjkKfsbZWKTPnv',cUPMDTk: "\/8154\/json?__cf_chl_tk=1mQp_5PlXModlwANqMm40_ImBq487LYQ3ad39tzkox4-1739784202-1.0.1.1-XxoGEMAcMjt9cZdr796x.5CYB4a0a9x1Fo4zv9FKx8M",cFPWv: 'b',cITimeS: '1739784202',cTTimeMs: '1000',cMTimeMs: '120000',cTplC: 0,cTplV: 5,cTplB: 'cf',cK: "",fa: "\/8154\/json?__cf_chl_f_tk=1mQp_5PlXModlwANqMm40_ImBq487LYQ3ad39tzkox4-1739784202-1.0.1.1-XxoGEMAcMjt9cZdr796x.5CYB4a0a9x1Fo4zv9FKx8M",md: "xzMzMzNX1G0DTye6gwD57TE3eVCMe7dhiN5zsjuFsl4-1739784202-1.2.1.1-TPIWeNNo4E9ObctTO.TLSVE5xZ9gXf5TQFtFEKPRgEZlYqFGoAh.kL3gIqWRvFxBA0H3Ig.Me_vFg4_PXHWaFRpFQhq27FCs1SU.gS.S3X.1JA2Bu7M5iQg_J96Msuy_VTT.QIZqiq5PaFz1q64oBHlG6aeXGWTxkczcBmhQGfDU3Aw0O5D4W_HqeculmzSYeUclMAfoAae24nEEpkOkRHH9oDkpCNLsiBmtzkae03h6qJJDR8HdW3w9qGQB4nCTPU32h1aqvOJ8jvwT3c2qidyrO6MnuvNguvfCqPsunw9QxLDwUUJJNx2OD5t9YTsnQraD2TQ6EtBmIP6Zxo1APUDO5V5nCFYXmYHx0ievHCz7ITk1vb7bPljQs6Zru2KDnpBt56U4ANNbV2_5qTkKMZmu_Yx9VXvpuOXfqs2XYZT_np2TAxb2rEO0yXHr8qz1oeFuDNNGmXEaDlpyjJ2XIzsQ5v4k65ZeAXHqqnz23dbN4mPlMOSFucNVoxwYzvpKtm58FDT16S8M7.1ETmmO2kApDZ3eVRL54JrlT.75VaOwUGnH2.Ojinon7VrjwEzYDG1uheftGdqQuOft4Y62HMEK6R.p62ZgP27D5ubkE7nxRqe8rvUND_Vm9eyeXF6MvAyfHBPMMYElkUuqYrYjXbfRnAVvYr10iZy4W03A4dpiMBVin77YhHHjrKG6RkPOHyx19avO7YIeRbQbWMAZpIHF52GY5HLEg0BQhAVLEbFAhB4hNTfvrem3jGWnz1yXO6HLzCPZ0T26cr9E1VVWcxjP0OIrSkWZh49amHqeRfLAha5FB2lzh3OPtnou2ozEoIpcCnuSOf7i7xxRL6xUuaxo9hFlKZxsPX258cMZ1eyhCgGLHP8yIwtynjOCFmDYxBt3Cam8s8igxR.gQMCyrafehpwTWUxLKC.YHUJapvfZ1sJ4hI1wRqaX4R5Ykx9vMCx0M01nC5Pg79Dh3h8QnoUGRRFVQ29T6H8jzXf3jjUVx.uNPKfWExuhDUvKVTyNE.3optdh_HdXqSaS8.SSNeB3i0Py7BOb6tKfmFjhTQGL6QDo9_Nz6tBHfE39Zd4osfoVB1KmXlaCQYbTLPcmQ6bj2Dej19iyzqVulCI9rDjU_AfVdEBwjhMsCL64tby9CtwzTna8mUB3rjHGxplyi3zCmZgiEji7GAW.aBD9WxaCB3ci7q_t48IRDR3ctZst2c33ut6MseBiROKZZtKOecjjfaDdoMoiuBS923nraGFPJ1s_un1V2oIQAweHpQWh5cmBTae0VB9rg9.UNZQo3ANWpGDn8RukcQVFRsdCcK0dw2D1JX4RNHvrCdnu9YJSHwdU5fdqSzb8HWc_yRcJsvKwwEvSVlUTPAwnG5Os45QGortD0Vvi9sAL_n92jKYmofuD41VYxA.BBG_QlYgD1Ldev60p5NhR11RCuJ0JBZNVIJJmsz8pQArkmeSf8x2WtfU7983CIawLsEZaooVqWDE0JnenYJXZf3CNCqVp2iW5BvJkCK_xzfwIhpVrfb7zh6sAxobiWLKsCDlRD2x_5Ci0oCqAQL_C7pRSmmqceHw0_rTo4eePvJXv.FXQtQU1M69lNy.PuSCFWjQPrEp6JJTLkxcCOqKtlLnMy.0EKFTDFZB9Tq.49Yl1EpC57gMFomyJkyYP5adrKRynd.HJy8sUDMdb0UWxEBFQDG6R7sB7mblUMueUNs7Vu7QNfG14H8abqRi9lZIuCVyTLHiacIVdMRLORiId6emfFMnxy1WbFcEA2MLczDpmwjW_ZxxOWdmi7Eq0dBiuF3ATvHETRB5ybQAEd.kDz5PJflu1fuhTXji1I_AEgjp7kToYuiK7TZdKWyOoCewLoSoycSck1DRi13sBccQ.KdJdbhEaPhE",mdrd: "HFp_jm9ZfW7qKVR1zjqU.X3cw1NeelOwhllEHtN1Zlk-1739784202-1.2.1.1-IAEQoSXwBFnq.ZXwrfYyQWVoHjHlvlguDMTzpju2GNpqlNXZSokfTUA41P8ovQgOXw0zgNgU8pEn9z7dRQ7OtsCyPfHCVQ..HksX9nNWOmKVd2YVhc_iyo84uNxEBO0Sr2wsHRA5e16SQ21Y7Xqec5irFlCHD_XRna8wCn3crYdO6u4tuCtYWhxQfZVa2KzMQeWJUt8XXrGS0xxvEmerIsH1VWwFrj1H_qZJm44J4Qcwgu3BMHeI32w8NGZKvjSvoNlSnnDYK8P1KNEhThRqlRvAMIPCwzuBzG2N8jsfLQ5wdfKlfMTFgwlEP2TpTYlGRsRmytIHtdVZ1B9aZeC26sVC502EddangV7rS4xUvLWFx5JRBZqIN2_afokZlR9Mx5K2UZNjsjrh96r_x1FnKJhgf7J0Jx6Y0sE5pQy3rVQesOouXLLjz6LCewkFsXV9Vhgq8yb9z4ljbfynYCaaGQUsBL3kQONkxJnYkUJ7sBgbkaldT1OTI6ZuaL0TUoTdlxkfoDJHF74AmmTUpyNTE3cX7oxgVSzCsi7z6FE0WF1P8_NfzPUFksBDPAJzKKhwzRBeABseXG9LvBCZ0a90Jjh.tnuidRpkA710HAO0FW0mUQ5oEVwvfnAK9PHLx8mQClnKuQlSzIcjcHHCnf_tRvTros_XnqsfJlLJKblGv8sWIKIjSbCwOxLYwjcJQ4AAgCWXcU74lKn.Nb3cy4VmbLTnKxvs5HzmUD.AhkbZhGcTwmgV5CIcGONXoJFak3BIxzJABEATZMbMlg0HZVk3hrdN.bT1tEvbMVnsv10zNu3oxgwB6HQ9c3jX5V9aFpCpKlXdEEDntl8r2HYec_Nkvy0d4fZWtVU6iKGi3q3AMtVgCQTg1EZotc45bnsLvT5E7mA5O1xpu4LtUUyFfQN7Zy426vUP0gvLf3ACE2XdZ2rpJcLy8mVPCcNJnQijyu644mK6Q5nAsLJFXMKqRST0IwDXLz7ZuHGmUw1qoLZ_rM91j0vqqsZzVxJ33A3YB5jldOkfNxDzmNna8P1389o5vNS6FT_4.RFgEp4tk7cy_1kSbQRIjx_qVhPSaOPuaFNCSoCaUa0B9Qp7sApzXtEXWvdJfSwUgZNBH67MCqdO0X9LXdfzKjMWnXp.eoFQ4IrP0fAohqf_WhQbpthDC1O3y8BzF6CcM9aaJGkh3NZqAiHS4W5ZEOewmO.yFLKbJqtuMeW3.44ScYz1vhVj.HPtwM18G.Fs5TcahAW5Hn9SSXmjTjZpbFpS6KxzByDBd45GNfpAtci4jcgb_ho1zGx1C4MGqzs4ZXlFbERgkM3K0xS9OJY0YtlLvovKfTeTaUDoSqi6MN6GoK_9W_gi4FBjpLLeY3XBeU16kgvwM0d5w4iq7ZGNxflvxJQdtoQgQ5q4tc.35uG_BK8_7GeJ0guV6vkuUQ7cq49c7mKp11ChVPHRXvRV5aAukT5cBwGGHpb8MWJHiv8v7EitutQ_UWP1mxTyzYW04N9AgKj74b0yZjXWGwxCp5s83EZoDgA5NZItGp2CPJJ22aE9pYtqMMV2Vj.ih4BxRbW7OGgSYTuYezmU8JQMLr5XP6N5tWtKrJ5RubY1SnswI0dT0nJ9Igkm6l5qcP.npUmj3kh_Lm4pEJM_Q_ZqnJME7jfddwpBPVTGytFMs5Kts7hEeY.JaP8HtglrN9oQ2aa49vuSobLfVYnU.iixZai6Ih8b0wDWfC3lfTD0xl2BKsRBolS3Xq7pfvnq57UvHQMg.weZtrDZ8ZqmIPOAdZ5DmixOjV98w4IDY05Uhq1VVJclkd4L4CWjelNd2o6HY1IpZUZithkMsvsZsCRU5UY8pYPmoY4oBa3Ux5nPAv1k3pj_6nH1SpL2aHjI.bMk0YzCQg2ho0qV12jwgPNDOldjLSe6guiTod35pC_3FyqWsKseNvV89yD5.y8ux2n9O7R1Bh7ueMnEOFi2ptyN8gAD.z16Z9fbQS7T"};var cpo = document.createElement('script');cpo.src = '/cdn-cgi/challenge-platform/h/b/orchestrate/chl_page/v1?ray=9134b7e0fdcd8965';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, "\/8154\/json?__cf_chl_rt_tk=1mQp_5PlXModlwANqMm40_ImBq487LYQ3ad39tzkox4-1739784202-1.0.1.1-XxoGEMAcMjt9cZdr796x.5CYB4a0a9x1Fo4zv9FKx8M" + window._cf_chl_opt.cOgUHash);cpo.onload = function() {history.replaceState(null, null, ogU);}}document.getElementsByTagName('head')[0].appendChild(cpo);}());</script></body></html>