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: '913615ae1a1081aa',cH: 'PH.YA9yuygfao7ZOa4.QpIz37esNtIXcfv8qzZirNqo-1739798530-1.2.1.1-KgnX1oKxmF3pGv35F3qQQRR9NOHCbr1CI1MVWDfoY9MCeZ.MA8qs71hnZg1Te61Z',cUPMDTk: "\/4174\/iso690?__cf_chl_tk=NgPyRVkQqVogOugN81D2LHWV0vKV.ubC8tNNlaKia5E-1739798530-1.0.1.1-ilHOPYZQg6PnY6HExJ_P7fpKooSG6AADc4VdbbYr5oc",cFPWv: 'b',cITimeS: '1739798530',cTTimeMs: '1000',cMTimeMs: '120000',cTplC: 0,cTplV: 5,cTplB: 'cf',cK: "",fa: "\/4174\/iso690?__cf_chl_f_tk=NgPyRVkQqVogOugN81D2LHWV0vKV.ubC8tNNlaKia5E-1739798530-1.0.1.1-ilHOPYZQg6PnY6HExJ_P7fpKooSG6AADc4VdbbYr5oc",md: "n3rF1Z8w9Drrq0.9hKZz8phMQNbTTHA2y9wte4Vtf6k-1739798530-1.2.1.1-hFoa1jRf4QC1FeVAToWGphAHNVQKHCGqROFAC78zMdvb_8JK7IHSknUpa2C6eaK1j4VSsyRPbY.jh.4c.vLtJnOYRdhx3kZ88_ZlPEcfzku3B7_KQEL8sbyjUfckwB2hE6t1TbSSGReOT_CfW33HhoC3nGFfjequc2owasV_xLWndvxN7mXW_y14rYYAbghCn9LOCBMmozSqZ6NpAlfAQdN0EL4LZSCLYIdZcQM.ZuHMfXzew057S0ce0ifkiCqkf3jm3YjmIJkQljfSIc03Pq3n6Hz5CT84JXelG3EN_FDH0mIjhsDYpKJuVYdNmn3zhS_ZD4bTf0uNitf72VPjl68O4n.ppXn.34W.1STBgtvsKsoEZ5srl_.pWB88nndFCBPQhxftG.osdSDALIETdOPQoZchg_RqS7twi.UAVTIev_eekuEtgZzMPH5DLKQ2MqgjV.p93b8nWgI2ZqWo2ZeZAGNiFavCx7pKu_xKWCEH5aInbY5cmmDEc_POycchaT95pykFNn9E3pPAnEUHGt2WFM34fG8LqZ0Mf95S6FLW8WZFtaRsE.ScHaEGJ4Mp41B9iA5fSPwSMg70iOJcmHVTMANgfC.C0oPuxoLZk2Tpu1PW.QyoP55GBNQneqJQzOHLf936Qs9Kva.tpJQX2HApkcrW1EDD2yQLytpVe3lsYDPs4gVSxSPyGfObArMha0Q.M0HxU4s0nzZllIWTPgHasMAkqffdw_k6sLE5GSOvhMSjlqK8KirJaQu5k2tUeDmQu8Nknh4Tyy039RaHCvTiF_jS3Bx5njHF2_uBH132guOqvrSu1XvQDWFXPZWwtChg66NUnBiRyE7AKSXcaicLwXyKrjpMpmSvnYvvhTbJaJZPvmvdFb8PsO1q8aWx0ODJ5YChdNNxpsuAjlyYfQd00Hh7G4QbHml3.0Xq1K6PfgFenyZ3FPhPhRb9DLX7uAm.tUapW9J78XZJfVy_Q._.NjOZfFojMiBNgTOs1Uwr8qWGAIjVCuImV9aOk5yNb0p6pS3oHM1L_MeYvaEgJYpzn2MNECxR5t.aImQ08k3evnnnoajERAL4fSXGmBpGnLKitTDdUKDdlm8XNIG.eebP_Kee0iiH4eXlRKxRBKOko.hZk9LlpFEF012B3c2rZk5VKnbJwCQe_K7HRq0vsQzdz0UgmFa12U9FkzJUb7TpPzZ6sOM1qqnH._2YDHkFOp58PI6grnbYKtNNS9rBhj4kNDZ_qKGx8eid1d037JjVo_EaSBDFTtjcP_XPVnZ0XllEOssxgstiKr.zkwJjwlK8rvh7pdDE_l1MDg7DdWoAYFKs0tCOzbsV.RLjp_F1eSiuVcE4b.DBZhW1Ui5d4XTqz5jWw.OibMFlIWFe34w_ADfrtzHLYz_MA65B.lqWo4Je5lv4dgCLvzA0FZUO8JcCtskyA0AeAJE6cqBY0slC4x2BZefYwL3nimgzVDak4596HQ_eWMviq803PeB4XsDaPdavStF1xL1ca.aER8VPDcfNaaN.IjB4RfrKd3J5dR.nSXUSG1K9g2ueEjfVF1nj.tKfgcbAfVMdf60uC1ZUjR1A.E6fBGU6TUV4si.MnP3N2rjThzlARCD4atozzkTIyGJz2VzP.IAf78Vjv2ytxuGw3cwEVwdiWvTRoNWxKbxyIxnFNp6UkQ.IzyUQl2k..rloA8EDkTVN7zaCMdvyALbcmiK2G9.cAa0PgdM6dyJ1rZg6oMOYkRNrfXjEM_mg5fdGazrz_h5TuNgip4W7gowfXSileX6cbFSWfD5L2Fn4gO53jLD8Rg3XuQVyUxCCqNZYQ5Yq8Yl7VUH3zIxNq4T.4zb.ohq84je.NuOKe0aJVxIv1nS4B_y3s3AHJ9it_KORIpcJ2YeQ2mec1kU",mdrd: "uhmPGDr8WYmwFFQRPpGuIUuGpXPWLPyfp7GTX_n6JwA-1739798530-1.2.1.1-rgt.BkYb94Db2fe2vvYnx480.xeWJDPHOnj5mI.rBdSmzfbf1kDPGnGAhNTx6ZPkjb6WWxcd62p9NEmk3pwc0pxtWLM9EPSKf3Qj1WkyR8qJjwEsPdB7BSYgBKBX1muUPzrhT4oF0k6YujuYlvOdlm9o079w5RNpIBIZMthe_AgJSc0FUPH286hmtNzc7fj7Ab14nUNblC5.fnylYu7tYYmIpuOS.29LhtFmqtd8dr0dVtfuAWL6ZKFonQQBLrmCL6V3CwuQ6oSsySnV2N1LpGHWgsnDX60cOm9i3AWOgX2NzNhGSqvx_7TpRMhc0HAY2vnDoLR5WDejs7TZFHC2f0dpY04RpWweE4RVlrBwEAiqO7afvnC84Lkb3tpjde8D4zLKLTAybXAGRNPIpmj6x2mronVZT7c9tsRVIu.tlBeg_TJ_k2L.XM79fhqdzJC5.TfFrA3q5ZyVYPmR3tn28Hmy4odY_PGsFM9ooCpWkMICjwa7b24tzUbliRMgVpyb3gI9WR1FHbdMCqZraTVXX45xL.xATduJfTPpXKrzpUC42YCHuvqM40sbswLj4iU0XR6JKe8ijumGb2o9M1ja2kK623OM9fMV1xpe8znmn0JJPKMQA6W0MIKbDSJUPjxZT73cj86.Wqo_tQHCMUl_hXY8X.ri0LVeNTr19lqIYgE7FC618D8KePkME59XIINxwFqk9fVl6I_l6Jyktv2yCn0ubPZtPdzZr_QrbYMBF1XT8LjSNxLDBYMcgBYPfKMmZ1_4Y2yMb7h0rhvOqMuRN1TMWIJvIhytzHtTe6qAV88HeUPvlYD2OcgjVjtLPjbroveLuMF9CR1nqlYrzlKPrpYgU2skT0H.aJyQIsA_ndLZzibImRdslQ2z9bX3Q3o9Sh95v.Md8d8t23EpWgVjGEPRIj_PxHCeo26ZdUVecpO3O_vXGWBfAev9TAARhquCUA4nr0nc2iqK4FSSpr3FyBym.XmZZXWPoPRIRwrPpEX.SDKcJzzX01Ip_63t5SUOGMGK6Rw1ghZB1iZA7i8zyonJXChGW5.X2Qmz62m6uQMtMzKJ_lWMVwY_6hoMLNkkxZCfd7NcyPhSlAIJdZ8JpKnzzQwANrI5vKAqrhrR6jPwUfJ3pG8xGPr2.n6OTBx5ZDwnWDLMpCBT0fFLvKi1qbPbl46tuAC_XRXgfF.7vTqMJ7lLefoEVN8QXMRAkmm.gBpEkIGjufkUJCutg5MdOKK0a.qiTfeb.ayoEcEhpzLpX2Vpm1jT6sj7.05y4xmi.8a7PFbyRyXSV7cYm7ycGyzMI2CJTlpKJJIzVJbeQzAweXnrJJFZ1knZhI2Q82JX4WS..H5vO2iRv.XdYPRClGodTMIAjB0O_KHxG_yq5qwim2WqNeykR0OZym1axAEOcalYNBJrtCeXpOuGyyKkRXHJN3.Nox0m3XV5tjfZZIuRpEeVObMsuFF_.YUaSmiZSkcRTas63MzVoTFCiKpdpxqlNihl.lgUUQYFKmZ5E0Ln.3Wo4ZSHCaeLkz3xjrgR.IWBNv1H.rarOelS.XOTJwzmsXXcv.xQajuFj00H9rbcCtyX3k3vynMKf5sTasQtxdgusX6CrJNkFfjC9yabWRpHFZxch0Sah.W0wpiqZrrhdB7yIt0Ekcxo04Ctv1gM0_GXaVEtkyrJsxn4FBrBPD76UqcgXB1APDkiNjbxpOIX7sG4tQp3U_J1YstLO2GDLhCiRnGwJCYNKr_zfv1eUGX2WL9Hif2ydOIrnY1VuF8Am8qsrEyLRYDblbqhA.Qv8kGdd9YFpvxrNGw24dqYDawWmMOGe8lAPRHTN1_PaZ5dpg3T0ndm6gIBATjPuyDgCU2QYFmZo5Xy6DSKRR_dXBW0DL0D_jep6ZXFoQhjiJECP5WCXjA_.VuvWYaSI8pPNAxPZsnBR81aAFwnwum4W7kP32jsrHK.6m8s5xjxRdGf2ECdKrc4KeJ1MlMMS10E"};var cpo = document.createElement('script');cpo.src = '/cdn-cgi/challenge-platform/h/b/orchestrate/chl_page/v1?ray=913615ae1a1081aa';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, "\/4174\/iso690?__cf_chl_rt_tk=NgPyRVkQqVogOugN81D2LHWV0vKV.ubC8tNNlaKia5E-1739798530-1.0.1.1-ilHOPYZQg6PnY6HExJ_P7fpKooSG6AADc4VdbbYr5oc" + window._cf_chl_opt.cOgUHash);cpo.onload = function() {history.replaceState(null, null, ogU);}}document.getElementsByTagName('head')[0].appendChild(cpo);}());</script></body></html>