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: '913418ea9c5a81aa',cH: 'nnZbnSxVHAMLFO1Q0Pwdp_Gp.pkrRjT__T7fyMnSY8s-1739777691-1.2.1.1-Q6MMQiS_ioQZEvy3nYLz4wZoz4oon6pUYAfiUywlp0GCFG_YzUNEK.cxuuYDBWIx',cUPMDTk: "\/9998498\/mla?__cf_chl_tk=cAuKLX5d0X1GnMCdPlhmx_1DndFU59l44RRAllz0g6U-1739777691-1.0.1.1-.k7ZqY0ueYGtrGs_jWY6vpvXg3VxTZFr9jjvCXBvjCo",cFPWv: 'b',cITimeS: '1739777691',cTTimeMs: '1000',cMTimeMs: '120000',cTplC: 0,cTplV: 5,cTplB: 'cf',cK: "",fa: "\/9998498\/mla?__cf_chl_f_tk=cAuKLX5d0X1GnMCdPlhmx_1DndFU59l44RRAllz0g6U-1739777691-1.0.1.1-.k7ZqY0ueYGtrGs_jWY6vpvXg3VxTZFr9jjvCXBvjCo",md: "cis2ekybn.QSm740e6.Td6YNl1mxpy27gdBxnWPGgQY-1739777691-1.2.1.1-L_a4KrEmvocSU6P6np1v2z_.251SupkBusJBKMeY_A5dRnfwBypbE8UZk0Pnes8I5eLIYrQ5cODmqfM7eIL3I9jdPfm_AUDP39z1p8lYv6ye_3YF9XaJHeJ0o9Ha4_PWc3eoVpmOuAmdAPp8E3dPo_8Dr9YWZkS4pSi.Co0c6KojX_CN9zAN0RnNB8zXVnihWsdAMkm1EKmguzDZz2BbOqxd_cZE9qiKm9Fgm3vlqD8e8p6o9N41A7Q3E_6gERnVspMVFH9SNbjbuF0B9OOZlnKhkPeSeJbVPh_Gnq95xbU9FjtJ0bFVVnbPH1zplk4tUjF8NGvDyc7DGemKdNLQlgtQUSfrUW90rMoMePPwtoKrsqsXb8BJmlnUEpANhkqoF62swyk6X.37xJnBA.Zjfgt1zTJdHAsrjkWt52QdLdSfnrzhLtMuQRqgiE4.qRBWvB.Iwy2HHk3Sm0KNYc4FeMWUjhrOj39.A7kPDp8KUPPxuk9SM0Nmk5gKRolHc3RvC4XmsnM8HHDvXZrVaaX9mYLYFN5fvv7sGYN_dwEvnJcnmk6aXBsMRCY300LXt_6Z9TUl89lGjujOl_wJWU2osQLEKX6ji9bDIxUfUufz_mxiTYO0nnQ.rl1b3_j2bg.g3RhkwQ4Py1O2P0oE0gzABFi0KfsqdtqTJzQvpn5GcKY8A6t4hKgbZk6uqVaqAjk6PFNQ_oCqfAW1KA1T3cCokBMj4OB5guwvbRghnIvTodrdlOhBIx.0odYbeCQeQAyyUsAlBvJFFKNA0TSOXEGwFK2EmFQx2yEZXcel_C7VoaghfoEZ9C73V0lJ9Og4.MnRLaRORlz_2T1q0mKbvhtZ.Fga1tz5GsBiDou_qCn40yT1Yeg5__stG7sgNF9Kh21iHgSgcAsaF6amfwxrRauYKmMw8deqez5ysGDpIxNTX1R0eqcU9.u.2f8uxRdg6Ytl96GgiXxfnlWnPK5EaUt55eU21nm09lbg8taeSSRPFhcryM5SktTKa1O4DJolWDNzJydyzAFGA7VvBGnKuDofrdvE4EoXwaX_sLzmN7musXM.JNTdGK9r0FnEdXFk2YBNXj4D5E3W6o5aOkAURblBSvM1dj00owirjDx8S4MPiRWecuaRxkEPEFqS97_13yIe3jwbcmzdd0oVEhv9tisZUIedoeWDIXCug6Gtst0qD1k0oXvj6A9NFS0mSJHdJLA8ehoTlZrKne_6RkXGk0JhIjtmjM_m7MrfcPYlAAyQVO0Ufn8ZR_rd63QcowyJtg1eiMLZ.5G4JAe7aMssNVGHtfVtYw6shthEDmatb0ro3G4D40vRibF1cuhcLXFW8WRLDuvGWpjFsSe2Z5Ce.91arMOonJt7xhd4o_P7EV7_6TP7rrINsy4ivYYEXXKB_.YaV.cD07TgvBbHZaVaIgbd2jUfuNwzePL5d7BU5gH5d3YDQvsBZtyYwtfK7RbK2OahE.NIvKxHnl7gj6WEV3R9yM96CQcWTEfadB8qUFnYzHoDY1wcY09l0wya3UR2VZ7DLLuzu6IQ.rpTiuNmpdwTBESW1zRnaFENaoBxyleLObxq4slIpp6pPar10IGtaIAXwZZGH13XCKw.1Y3gGdOt3rYFR3uRbOmS2YaWkrWcpfxHgJfTazOmeuutAYPjPZF9apjqFSXfWBO5dgAuhpi5vON9KwowwiFXgO8us1l_a2fQ7s.I09lQg.hcfiIlKUEkkCP9vlCWieard9yoFeqziWDfn3OUiIkHeflOlO19dq549IMoc6lwjoCwCWShIKgRQoiDD4D1MJnNt2CxaCeJRdiYLpjzh_jFaXAAR8E9ydjjL7O0hBGEy3AZ1_CV4L1g11Muz1q2qJeqg122ptcby3KUqj7rz.Xto4PgAqPNLJU",mdrd: "XC0QnkuD0PM86paNAmqh8anfUbgvA_JOlb34n6_z2xw-1739777691-1.2.1.1-Uhm.FURUX5BdZgWOCEPd0bNym4zA7W.LWRRC1AYJpv08q.nKW0Zn.sMkt_zYgEYPZ5HdPlv8cnOf7ZIl3UPfpjfy4cxVeNyBanXr9z7ZaW2jLnW3wr6CkFKTMyWEAk4yKk1LT3CQxr8HJOsSW.RX_TS7xHoEpvqduo6W11wSvNTyJU1E_CUvvRQ.vSVpjeLfF_EePJQJ9NnpVGoE_.6RShLR8rmhnU9WFTk69JPHw73WnXkOFdzkp4r9sVZnlPONlzy3vO7ULvtQnETWa.L.dEtRrPW2Z70QrCJRyMtmPbfEnH7UDPJ3Da4R9TOIW.gnhg6Ka2Dcqzm2xkpljmYuDacyEOhUXquZIIe1udLJAXddPmhh9p6qtaaArKM.TkIXZt3eXqK6YMeQSFOr9B8MkouzF3kT6bFcOU6KPHk4OlwJ8jd6Ryx2Tv13RY3PTectCKn2Yacdt69I_Wa1oPCMYeYKNtAiVfdr8iu1DexYql1O0TaMoFqRvWyUhAS439iRG_mCeTPohMblOBKO3qu.dSrJl2v1QqWAZPnoCj.uQb7V4NoTVN.fNRvVIOkc3qbVPrVXNNH3g9mxyKntg0q863RIDVO4ZhLCoYAh8tH.tYkLodJniMBcC0Sooxrm0A0o840VgGkCVCldoXBcV.FwxbOSer5jjoltq0TdOIw24bAhw_F_EHdKc9ocsTCMNDZNf87OZxioaFP3ZuNXUIeQ0DQxy4Q1lH.paun72UAjV.DNn45nOyYod1d_ADzr5FLUdSmuHkANhWchtvpVVicls.KZ..18w5egLXDszmQ6kOUFx3Pag4He3aH.fBBwITENkQlpCsvMzsipNshSB6He4LTsUG7pbQMzmntXb4nPRm7D2OTzBYb2aBUhTTO6O7sz5Caoypb0Ljt.IfxgiltfmYNWTwxUyU3IQ2URCRWK_MdPdqFjrtc.7o1Vhxa4ODTiymUop9xK7gGBXf6xdehXYx4nyHdqGuSytsBjP6K_Hhvgc66K.21YKYA.DrQbjO2SXRhuJrsyxWdJUz9o8iXjIyHfR24A964Iln27_z2Z8wOJA8xLfnzQsqdoq5VOnUmUBtBG9TckIY3QWIJUvmlyjVQ.1bDi20M8yROmaivbNtkUjA5z_LHK8TE7V4qqbQZ3Vtddg9E57RWBMJhOecOkHGCswvLPGeCYU7gIln_2poxA9Y2xZFReqUcNDmm_ZM7P.x430g8rlTFFmT3yrpv60YVOUq7fvTrEk1lFB.oYSx.mh99bvgb3S02RgcvETB0263mWzWK6fUceNsjkbSAIwoZfn2.xpmRtYhryopLPLpwesj899Yt.UAjqxTGXPYqIzwlIEd_8W.fkDNOIjIRb6TS6gcBz.Hp06tkIS8mzQiiMU_W8_5pa7lGxq.7B2GKoUFfGtnUrUMLcqu6BKeE8sKvCfbbrKFjOqSasaxkbctKpZJEkYWt49DSxBodwGNsWDEzBYOGXJuVNjBbs53NsP2cYV2ln84k1RvN1jdUAWomQxmYewjhxSzpRlPo2chCqEEWJzKGBgjBQ4vX5x2wqmJ_qztH9DKFixL1jjNlsoqSiN5l6vZ6_YgWOLS7AyzUmREov8EJr1DW5mG4DTQges0LuZkMob6tW2dqMbzHv_exRg_YA0jn6VlSJcUk8CgFEYmZnnAj5bLHC3TB7r0ZReuh6r7BhalDgix_8etwnX__FfwGE8zRgcbkMK56kwhlE_m6NrdXr0A.QkSRv5OICPeq7Md07eBc6EWPuvFYbZoZVzCkuZ37PyHPw88QEukwetKCsvuyeumiauHGPilEbdfHYFZ1mwiP0WrUWU7mojmqh5IUfPZNoM92o4RDWAZxgKz4ePG088JLTXTquuFMGi1niHVbCnZSc6bmsAJ24yKRWy76AjlAHF8IG8KFhXGnRypa3fCxcN_.cgj_8wp2P0Dwr9PKEdJPM.Q0bGiHKl5uo4U4sSOdAfllr5N3octxZ"};var cpo = document.createElement('script');cpo.src = '/cdn-cgi/challenge-platform/h/b/orchestrate/chl_page/v1?ray=913418ea9c5a81aa';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, "\/9998498\/mla?__cf_chl_rt_tk=cAuKLX5d0X1GnMCdPlhmx_1DndFU59l44RRAllz0g6U-1739777691-1.0.1.1-.k7ZqY0ueYGtrGs_jWY6vpvXg3VxTZFr9jjvCXBvjCo" + window._cf_chl_opt.cOgUHash);cpo.onload = function() {history.replaceState(null, null, ogU);}}document.getElementsByTagName('head')[0].appendChild(cpo);}());</script></body></html>