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: '9134fafa3be8fdea',cH: 'Sz9wnjlDEoajqgDEwjvBCWv1E80CWdA_ePE03OySutg-1739786950-1.2.1.1-KhE9eESNBtmOgWct13ZmFmqZ7gVATVaDofPd83riQi7MaNbQNsxpCciZfyXcHSjY',cUPMDTk: "\/6878\/iso690?__cf_chl_tk=0k3VNB2Q2wnaFPlSOL4stQJJsQIsVjKnBbu2kZi1l3k-1739786950-1.0.1.1-So8yiaCyej7Q4HGGiqdJZAnCG8MhSRfKCtm555yGsTw",cFPWv: 'b',cITimeS: '1739786950',cTTimeMs: '1000',cMTimeMs: '120000',cTplC: 0,cTplV: 5,cTplB: 'cf',cK: "",fa: "\/6878\/iso690?__cf_chl_f_tk=0k3VNB2Q2wnaFPlSOL4stQJJsQIsVjKnBbu2kZi1l3k-1739786950-1.0.1.1-So8yiaCyej7Q4HGGiqdJZAnCG8MhSRfKCtm555yGsTw",md: "ifgCC7qwIue.ydCD5T22UW8njFCwxpRmXA_mHBpHUVg-1739786950-1.2.1.1-bz.mWym2SpL3Blnq2vkrmaNOu8ZQpZ_QyqFqULGt5nt2EOc3KbHjY.JE7pTFURCwVs2wuG7aaqOMigENXjm7ssTYV5GqfvDQPAEf.OFslHbiGRGBhdapD7UOwRzDo7gU.fFdDAtW9_H6UaCmDsfyMGHsPZTwaCW9IOlFbZOnX8QMGFSw67ceIoAvdLS4gPxGwEtsRtv_FsSvqwdGxaHGGkD6ZQnrSYIutgtTEcGM6VfPKKDPPiqskWCNOrhXYqQ83HRe.SZRiJg.Y8GOBTwyPwKegZPPKiURsWGYf2Sx8sLHvK7.bxr1DIQFPJ1_SNbmGtufMScb2.u7.w79RjM0levARC7K1ncq2jOkFPN19CaZMPGOrwz34nWu7HMPVll3YMhYYLQ56Pg1YhNsNjzfGZWlL0fSCvBxItISQnD3s1bVLcR3xu7gRQMb9aJHE4IxFy7kCyuiFv8.F1ZytU19xqonjQSWtT91FUO9r7uOaN7l5hF_qcBwjG2e3_tWGFyF2aDPKP8QDjXaN.s7N1vXR_CgNStjnISU39U9yHPMGXP7NcCw4QcNzVMHV2KDJ.MbTyRlqDS6XEb8FMVDddNOtQu3MIpqTYT.5OhInFgG9Ix1VAqx837us2GV9ToLYOlINeLMqNc8WpPzyyU1Ti_GD4loAOcXh3CEa_d2RrQVGrH1nm22JySDdOnwk8XXv3I8YarffOy3PMZu0gi0nykvYHkPe2p5NNpSShWBnmkMCFKzhIBc6S_5uzCdUK1xxy7VfmQ.ierOu5LapyJDAf7.pp_QLl1Sloul7dpzu4OJn6JW9h08ILso_wwBlnBzlGACTdfJQIqP39MZ2Ws4hA6LWyqwl3RWicawOtE5BERZ3tKLTNwyiXSrq_B6ZqDtOywGWdXa9KnRX0AGx_MAUXzg6GgCHc9b._yA2u_HOWma20TkC8JdWQnhSYb8_7GB1K0tSg2sfkZKGK8LUe67WVp7LzWFa450TLIZHOeODPlJAG08bLimO.y0_2oUxDrKIKaA5gKjgcTTxtUstmNwF4djxxwtYQpBi57yG6PtLytgggnE5989Ljjfd0FjOIedZ2Tiq0hfXA08HcNhdLbcdcL0Z2SbX6Ou78n2N16GEc8mhJcxlawJ.RyuqPYT3zYivzPdeDecw5Ia56AIniMJKn4QYK1yFpoTiXGKIPE.GvLHq5yJtByDC2lI28PaRE2ipX423kgrRw_KFsW_zj1d3ZYPUp0PfjtAHHVOapL3rFjoESCWUcK.2Zcz2hRIFkCjEBEfIafiKBXi3CfYavKWi_9VXCgAlfUuxmRfQXqAhGw_X2iLeIKZdPA1Gd3LKNWEBe4mYMlMWGrfOTwZj_DV48y6rIgf5Ijd0yT6i4MKJmuTB_.smxSKRuNMvTU4YgtIMJR9lLWAPldSqw6CrcWfKxzYbazyoOLu2KW8ET5V1KXjNUgLZnCtUodP8ZwJ1b9AMC4R.w2r51bKZiE5t3NcFQHhkE6tnAaCXiyCO4NYIpX3qi.mvrUzKZWpQEGJIivgyT.xF0qDCwk6CePi6i5QqH7A30HGsvnkFFsIMuwWUTICWQwVvEkSk9NXTBafDdCkGmKMq8v.EsoBV_B.YuSSCG2.LodxP4hQvYgTrGK64ZNMJ9qmurxYyntuScbnPSUOfHhxoJWXopk5c.jIiS.hSyKKSyH00qdav7odHvH9kRe1kDjEq6zGMIPN3zcM.haFFsDrfTzOgrrEjZO5HAM4xo5LcdHmaNRKzqVckqLXwluuEZ8.PIih1Clj.ZWEsarEZHM.o4XhQbCeaVK6Y_3OXZ9WQxwYN3qqaUbt1Epj6T1ilTy.m3kOHXJ9Wk7FhzNSOrG9VqP0kQy5HoqIVb9nAkfFDp9RzFMP4a.h..ys6KE.cPQ",mdrd: "zb.s8R6mWxYBdT9Sm.Awcb8bAdfQOsgLRIwSNolxPqI-1739786950-1.2.1.1-IMVg61wjB8beUxJpxZL2xwocM24cuEMI8hUmadRbHp8EB3dJ3f0e_b0BpNn4fdNj37KbIQem2xE3vWhLq_pIg7r9spP5pVozE_r7gY.sm9iitalHsvmFN0_8BrAKvuy07gWL2G6clYtIYhnkIf.YP3YeuuJ_Qs2kIPvBFsuFhbLCkbgkljozScJMF2VL6dMZUqmA6El.Ut0bB4ZdIVcgzof9e57uJbrzF3pe9NOpijEfmwxTLiNf7NYw0ju.T5mqlkRuHH_jNmXfvadLoeSBU7f23SU_4n4e8XzGsiLApEpjC251RfP9OzbfvuzI4NGtGR5MBDTLJq.A1ZISJ54ULaiuVrdnb_QD3Kk0spQEp6A_JpSxIAOw4kdJLPJxu1Mr7XBEnPj_6SeMSRnnCYh4LUtmXyeksjRczVyobMPNDf6xceQYS6YTvpdn_ppe2j_vxkuqjt_X00OVFddOrzOZPq6HiaywW98Hg71AdJnkMT51dXXQLTtnT21HItWWl4QzHX.O.G027fkegGNYXDAfHpG3BFUBuCa8STKVDkbD3RRuoJ3FPcNGmNNuoAkXxQtTxXb1QWhnHZaUd3WecJq5CkZRPQwfAHHU7OzPEDXJjBY2MID0sR.fYFno0Md4d4_ygDWDS_7vuXPMP6J240OVsw9bJbfv0FQsooAq6MSzSokvsK.tNBlBDm1v5ntAeOGPz9MmJANcDy_5Q3U9rEGDry0o_ZbFoF8ASX0buRI14cGGSKz5tmzJgAFgxTW6ivXMeLuitwYD1wpnKwfBArbN6v7koi4Z05tYKnSFo76IiPIZJQyvDYl6dVYj7Bt1bLuHhaSe0XMoA6HJ08Y5Vf1nzE3.k0e4MShNX5ZslXuiOC0PbmJ7VCweJzQwkWojCq91LKek5MoDlXy4FLA8_eBtKQlI31iwmyhZ_sow8x71aO3CEgT4WNXdZVyzkrQaBJaeUXaUnJ_CSCp8Tf6zZnAl6RD7lO2pj_9ThZ9Lcq_jSSblDoMInbprLRyMpIeRmnZQuiypBiYaS4C4iklvAEPuK418PWzBHlCNKCiBro6HxmXKSqV4zF4N0xJqFun6AQF2d2Sift6QhDKgOVR6IVN8vCxzPp5Ox3VWLe4IflHuiUccK0cC.W712pClRE1Nhkwa.JTefaKch.f3K6SxgqOL9CoBPxspSbLt1j2kG0j4ftF4H4MkLEyeu6MhW_dwNNmJ0MOFass5BvAq3RdW.sAxanZILYgbfM5Jbu.Wyp9fp0HgQMvWkdFe_2YhZHXFXD0NKi_XQpHHK3PKeg9HeY38ul6VfNfK6bUzwItMitxCj1tg.na8iOanUomJlbN3qclK_31S.FrGk4AgMGpqgXGYWz.Fo628YDorBDJ9pFrLmrqfzXtd1V2N5g4yVFTV32Ul4VUSudWgb._56v.3RRow5Qjw5aO4oLuw8hyN4hTz3yDF25gNoaJO4YAS5Z6dw2CFf_W1RQB4C3FOSRETVrWXaHDIMmHWjEb44hc15Ytmaf.6lSnrsijV_nFNdGHr2XePoRYeDV1GkCWhzGwit6Jv3sOLLiSsAQGV_eeQGixWfMk.2KZlLf_ndEwsvJK28n1lwP1IEsYDcSg5e17immGdohq6A.jJLpEMSaSnASarBJ5CRPB3Mr9S3cWjguYKR8XrIE2D_OG164qstgdjj9G1OYZ_9pmKwaDqnVAGJSQ9dCXbPREzydSyLVJo12J6UZfGFSQ8S1f6443ETjMXv13EVWX.qOpL6zAhZsU54gc.QSgZ8NrMFtZ3Z2LrwevMJswd2.gSxuy6eDMF3Af2R2ogdJGuzks5EjHDucm8B5pvhSDAk__xgaUmbZSyfshrjmLGEjWaUMXSdEY_4mN7_BLU355a5lwqwYwfVPYiyDcAWFQAwu5uc_7wVA_rSMTHMn4WNDYXFudR8K4PQp8KdwzdO2nesZf1HvWAbQxsff4qCIQ19bdGFzLBO9f3wbAKLzGr"};var cpo = document.createElement('script');cpo.src = '/cdn-cgi/challenge-platform/h/b/orchestrate/chl_page/v1?ray=9134fafa3be8fdea';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, "\/6878\/iso690?__cf_chl_rt_tk=0k3VNB2Q2wnaFPlSOL4stQJJsQIsVjKnBbu2kZi1l3k-1739786950-1.0.1.1-So8yiaCyej7Q4HGGiqdJZAnCG8MhSRfKCtm555yGsTw" + window._cf_chl_opt.cOgUHash);cpo.onload = function() {history.replaceState(null, null, ogU);}}document.getElementsByTagName('head')[0].appendChild(cpo);}());</script></body></html>