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: '912dcbe1689dfdbe',cH: 'hjgjMp.diIYJ_Qem7WbgwSAFnDFJDTW9skXHlg8aODA-1739711621-1.2.1.1-HXc5WcL7Bua_vVLmIi_RpSIbHAHwFz._BFfzAJK_oYIYZEdz4BpmyQiRkt4N6eyt',cUPMDTk: "\/10012950\/apa?__cf_chl_tk=DP2ESAXDtwpRPErLw0vwbgQJSEl2oeEu3nWCzz6iVBQ-1739711621-1.0.1.1-TUc4rdPl4BfIO7JykwBzJLt9yN7iG191HNhnW7fKXi4",cFPWv: 'b',cITimeS: '1739711621',cTTimeMs: '1000',cMTimeMs: '120000',cTplC: 0,cTplV: 5,cTplB: 'cf',cK: "",fa: "\/10012950\/apa?__cf_chl_f_tk=DP2ESAXDtwpRPErLw0vwbgQJSEl2oeEu3nWCzz6iVBQ-1739711621-1.0.1.1-TUc4rdPl4BfIO7JykwBzJLt9yN7iG191HNhnW7fKXi4",md: "k2Hvybz93CdV7kC1a1aRAKSdJ.Oox3Yr2cSE.MeMOtA-1739711621-1.2.1.1-oDV7wf2EBK9BIy9xapG_knTxH_RmmMEtvFVBpCKTwzcff5AuGomT8pco8gVJ5mZpWcRU.pcatiNRIYikD.yVUXWwc2IiWsKHX6ltC0R3qncyfPCwrjL92hdI8_VpzZ2fRGBFHQkjU.0ZNtjBiE5MmdSXnnrUxMvCO0yZulmNHmhdNUDWAEmZ129jwWt9qKnxj1LSWC6lPh0COYz7I6SrIfWEQkbHjK0_h0EcUEtfEfFblpr66BtXeQgpgtLkIO.Knxy_vLx44r_csQj17k40o2V1XEIp4Gs_4it69tWyotJR8EMxWIK09giXzL8S8fmtuJff7LDWUlyFSYNfILKhZ6SoTdNN5VCfQfhzINi8J42i_LhrNGPTMjsnNkPrdyJ6X0Csl0b48QTC..Y_ABhkp8jDhBdU4kS.d7V1AX833R_IIMl3aqY8nAUaBeToLl4UrdfnucZOVTL3aLSI_CHqDpCr7pKgpuftCFJJN56f.e4tfjF4P9r40_2Rm7qWCC8R_M2bKj4wyTJMowlDaDhKphW4jDKGlzWvbRyrB955.SDSGWGQI2HpGSWvPxk9gSJ.fTggu_D3Qkw7Jk8yhEfGNLkiYvULC9IDNUKcyXYkyzS2myWqyMvEiwr.tkR7IbumkvXQeA3q4ZtGmwEEQ4ozbglQKYF60uPBq4BT25p2IFCEeN62EDo184wgRwxImMOJwSNvxzlwH_5tA5YlHmIKFc7Mf4l5edDQOYeUugclggM8rEr0TCpZ1JLgog6MzC9ucdGNjYMVlEspxF8TREShthJq52jgruIn00ouLdYKVS69DaurkfGV9PYQZb98rjRZuTqGGOWtvGa8prtrv2s6DCpEmb_qBYikmGGZEqUIoBWBnsVuvNWgoXbvPkEY7Fl9Hcgp8nd2FkhlYpRvclYR1ENIEogI8RijuHq21I2aPpdkl5c43Ze7eYoTFxPJaa4alYQ8xqmjvtRuOR6b6FxXKkXYO8tc4jWcWK.N7CFLcmqsBV4o7o3ft_.96PU07UnG9ltzLaRE.XB4tTd0bovdu8qqzZ68WKa7x7HKmD2vcUIovqvrR69zgdIITF_UpxNTy0v76Kb1ccVsCDHmzmBx7mlu74eolr48QFV.M9yzQcvhgHkBwd3OhtWVf9QUMTI9lNwY1d4GoC6zoOd77Z797HDk6VZtOGRxKoVs0zNvBuv7abb.JDjUa4il2bx1jrKjjqrG.595Yi9quu4LSaHW5pzECNBfsAGKI6XV.gctLqlaYeDu2Z6il_.Z0CaPQ7FSR5gfSJoUDlUCTjbMCo2wF9QLOBzlOFNT9R8gidQEHDcSASoFQSj23Vnvnt4CfJZb.3MC0OjwGCMOWrmxk..XNKy_dPSRLpxHT0EJgpYNCgmPdH9TiWqvshmkLQaI6l9DGctPY4feIzUInzqyaOxANqTFaUOS4.KhkW9YHgqKKeD6j2wdKUuNQYdEutcWsDICyyTLgOefGrio5IwQODEnc2jKlk2t4KWMy.QdPmys_5J5sbCBKTatIMUX62uOKHYbvzsMpr4wHNu8B2M_y1kkXWwoWgFObBN8MHM9K16CflJNvdMpAIKITCgKRnwCrPjiynnSjiy92l03WSACl7jb9QDyrsKgtr9EH3RdJFqbuAZNppIeXh.PgMTNSUumpyBSHNCa9o.IdDhmylSEqfuOMgLVRJzbCNyxfm.dVD0n1kc1WXxjAlyir4YtQwKi3H3vL4tCZ1NS9QLBeraYwfOwYPcSF6e.vPgZ9WMMkZfOglz06hLQZhVyjpctu66dNyJHuKlEUn2M6xLbLwFlLzq78SKv1wivewkdau1UaC7OL7.MTBQ.OhcyDsOWuAxicagoTYfrzO93bwrzlbC70EYYC949u8WV9rIQfxjDSSJfIUE",mdrd: "uUYvWyWn6.VlTSIHS_wqyRk0vyEvMY.VyR_1iHtXpYE-1739711621-1.2.1.1-1BOFNoANDngzz9tCOjWlRpIM3mTbZNkAj1FGa0p0RRvPoIb_CyiGVNL49PVI6vnr9iePqonAku32gPeu9gxLh43icAZhXbgLGgoA4yhFbU.u6yMXvRlatqByhp8Qm1Xbl2hGrbNsm3dw7VvmOhkON.0J_RMJE_P4HyBl7fqBNd_wKywSMwutDankhZNeuR6oJkNM0tyRWbIgpl55578penkUz0jrcoScyIvVJ5DrkryJ__85_PFVtsJGS1qwPCjJb5WTU27eGd5WKOYlltbdBK03qBqvp7IjhGtGdYWscF19F6OmSVxiTDvjbq3kVY4MvkXG80v7Ra1o.T5os1.J6NcbLbHWO9_ESjVq4kli29LmkQ6EBcZ19OdWuFCmguIxn_W1VcPN2KiST9SwfsGEHFqzs.UI7z71RW3uueFINWSIaiEqXuUwM.o2jArY2ZdFwMB23jicbtXyNYKTpaLoPWTbhbggoS0QBDgh1qeQF0SWarlx3OQWB2AiFolZjsIrlRvX9JJNvk9hA4mAOc6gw.9F8n5Wf6uSNIzo86FehE64K._mxMuNpwXJjEDRBFqEp4HCr9PGlESQdI1B17w47h_2t3uRYtcEdpF7Cv_iC8hVhasng.pOl9D51oJGPwfVjk3GJQUMr9CeOUQP2F8I58f0.ouCOBgI6x1M5SZTbDw2JVBFcB4GOQ3Y1wyxy9CQdd5xT7Dl5XzZ262j3ducPGJhyMfS0J7G6EHzUhSTxJ0AQVyDzMOJ7jKeyQo8m3KMHWYvLwKBTAG.ua3Ha0jIq5BQfQ_xi9Cxb2p7.AKBPi47Z7SERpCUbOMmiBfjJEG6UxFfk5fqmVQmDrQ29G2ZPEYoIm6SgkM3uChFHJ0JeO.aZPIINfOVTauBbjTInvevFSG2xsPuJfOHtexWAZgKRzQd23pzLhkMYvZqGjnkDGqFtMOUToKmviY3tA.6WIyxTcHnNZ5C.MQdP9sTw8DucvmG5YruE2ANkMbrw3AS6rvu1LNmZhNC6tkJ1O9iXDZNtRVzwSUL9MZGaqFSrgAEq7TSeR0AL5xvxcGtRUc6ZYoAReubxxOykDV9d_tt3haVB.703nDl0MBfmIvMo.9RAEJ1FYV5LCvdVtVydNcIIfSiaHCuP_j147EWNDQ3ep7RoRymHDcC.qgADPwlEdoQqr2QIXsBF4yo3lLZ1GKUDQalANoxxYU5OTOZHGLssLsxqdnW_NpwWj_nnM0dSsg3d8JPXeVr.IWOKGNowG3s9o1q_GmYVSWtd18FqQ8O0kFwsPck.a7V9wdBEtSyqneM1GBw0Z7Wbfh8zTvCxeeAer9RkvKV3_qgV4f.oQeKIeBEyyf0By4p97OG5PT_QpW9ou3oOyUr0rraMcRFZ.YLn3fb06DrUtZCoyIVb9cdGQKfI2tan5sVUlVMD6Bej1GEe5Dls84xTnkymhOgBX18SivJjlh.JJiBvBHVBhf9S3jdNWAH_4cUfFerU0QAM34v8saE7cDUjH6PCiSGLwDbhd2WpPM7Tj6.RAoNAlMpEf_y9cR3rxYjo26uOKZaDHQ1LMZMMa6eub0aZ6BQWCjsVxyQjdZ1.dN4h_av.oemqCsqMdjAxXlN8yR26z4r78NULxT_4JvrJsYMxO4dsjBvnJEbQptWQB1d0B63zIpIiIEd_QRBw2YQEe29bA5meCPRbmIvkh3Tf.viszV3qA3CbfnnuD5af75gtHqZTjyoWJ05RYYbdvT7PtXd_l1Ra_vqTEY3FGQfRGE1_uRwvfHh_l_BkH5eyCg6FFFZguhhsbI9CMcFSxpRvysI6P2blbO1ce0BSr_V_NEISytEWr1qEckfsg65LbJB2suKcD3u4qh6FedCnkjUJeSkw_LfscPf1BmFCN3R2_KxM_b7nXw9_v.3_BEdFQgY344VU_hGO02_ZIyjeVgsNP13irscJKRP_VqJty1ybbdD_MD9GQhzn8cSQDrKI6iItg9PlBcdMe1862GyTmZ0s7dgtu65zydpLg"};var cpo = document.createElement('script');cpo.src = '/cdn-cgi/challenge-platform/h/b/orchestrate/chl_page/v1?ray=912dcbe1689dfdbe';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, "\/10012950\/apa?__cf_chl_rt_tk=DP2ESAXDtwpRPErLw0vwbgQJSEl2oeEu3nWCzz6iVBQ-1739711621-1.0.1.1-TUc4rdPl4BfIO7JykwBzJLt9yN7iG191HNhnW7fKXi4" + window._cf_chl_opt.cOgUHash);cpo.onload = function() {history.replaceState(null, null, ogU);}}document.getElementsByTagName('head')[0].appendChild(cpo);}());</script></body></html>