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: '9134e3a34b41ce55',cH: 'F8KH8ffPusVH_8bEQTr_RrFTxfgrmQddPFQLB7BcVYI-1739785994-1.2.1.1-4G9zlbQbeFC8aQlhJVND1ic97qQo2FMPZugTAFsqhhahJtjL0VMgmPzHAGLphZqS',cUPMDTk: "\/abstracts\/search?q=contrast%20media&__cf_chl_tk=L3ywRN82lslJVeOzC0kCAKgqz9N8uRY4mKrjspzXYpk-1739785994-1.0.1.1-vEYZHL6Z_uIojfbDrmmNhX.yh.NIGkYHMmZ_kQ6Dt1s",cFPWv: 'b',cITimeS: '1739785994',cTTimeMs: '1000',cMTimeMs: '120000',cTplC: 0,cTplV: 5,cTplB: 'cf',cK: "",fa: "\/abstracts\/search?q=contrast%20media&__cf_chl_f_tk=L3ywRN82lslJVeOzC0kCAKgqz9N8uRY4mKrjspzXYpk-1739785994-1.0.1.1-vEYZHL6Z_uIojfbDrmmNhX.yh.NIGkYHMmZ_kQ6Dt1s",md: "U1HLIee9Hq5o3KjvnbWDTWgECUqedqq.jdif3TK2cwk-1739785994-1.2.1.1-e5lDf3J1hw0pLZ0hNC0n49TL2rG4pdWEe9FeuIQxTONYTdUdbAR4H_BfvAgpovodZuXEdBT03IzOs5xoi1SzdUDoZlgtAHzDL_Ty8p685ohXTpANMBjOuVc9ojoeOn8zuYiOMR1bxdnBZtPwAG8NWKmzPZZr2LoStEwtIgX5RTV9bLqgEgfp_b0y6symmR9ZChnHZfSkGIQg6HSiYvxshqVXMbvrWym440ilzFVuiTALi9joglSA073v6pK448fH7T77bCzN.oSjMA3mEWyw.iPcGvMhfWUmqcky0dY1AejEBNUTFDLY6UT7EMIX.FfnJn24xu1I7LjJdBs8.97QrldDA1Ymw2P70ymar2Q6amkaMHZ37OAOmtzdPkjCB8rjS8zH7Sv4A3V.m3jd0lhgYe5ffgDEMsmqhOG9h58DH8o.fVv69HYkOfY8em9QFfHzawTB94jB5aF58beDDtNDGwOTwN08bgvKWoAIHylaSBVorTLAVHNMzgQvT2liuEkZEPHvK4Qam.7tfo8g0G9icr1yMxBIlW_GaAc7A878xN5Hw1raB2GIZbhIXwWiK7MiO.hJEia0PMODUpb4kPWAvUVzXcd_XOJLGs6._PYVfnOnd2zuhe_NK7npCjFC3i1qLCu4dD7zDXEXihhi4v2ntuUkJaFwsn3VjOqT27qkFE5Gys2n_hgPTNFtxp5oZW0CO8bgZDfBuyx19kJSwZqCz6u2T5FNWdhRyjHvW00VX8oxxbNKYwZBBMroAzar9QtIGqCJtA2jJjWJnSod4HTqWmcY_x7iLdK1n3Ys6FjbLdjoEQJiFfVgyIVl6_iOZ8lfuj2fR0eoUmjqOZU9TUvaNHX9LW9Bt0QbAcrHLJT2pmVlNBHw_a.JzDSJDQ6oYjMM2v3d6_sE1kog4UKsyKw8rif3Xd3Gc8IKgJajxBsqI0n9Jui_6mS03RJLncTuXkL5gkVqwYRYpDTlTymtP.iRRtl9j3GlA2.vmJJmR9fj6bIUALw7F8cswoyp0a2qCS_dPe95kZq69bandgM3ZLn7DGN0XrLIW34HIIakh7KGZbZHkDWN8Sqr81cIZ1hreOqv8rYk1HlpFDuRSzwFeq4Y7krHwF_oleCmm4zxPqf5ZMmqwodJo5nhlkynOqSKpJqUgSYCR2CKujN_.OsYuxMEomJsHrtZiMWHNSklt.tuMaUYQmFesyC.Z8F2Q.ioM1niiIAlZTAFwBF5tUwYnqXwSubgREAEzJD3NCYJQu35MbR_n5eIQr0c7bwZWkhv8X1Qly0JZ_bYCD52JSXhZ9YbGzExErwjGz8A3sBTW27uo2u7lPOTzEnBNcLSJ_WxIHGVTuNF1Bpok39pEiAeAwLopJo1IarWPUO_uB_R6FlLgkaMrOcbwkJ9JgVsHZ9INcq2fik3_6DA0LPp5XW3VU91OKaOSyaJnfrBUy07QnNkqCKaSOolFOoCoC9GTJZ1WpJqtSA7.RSvtp20BMfDMarUC.8IkgoqzZxxqbyyjNPZJdBSU5WLekZb3jEmej6Sc_rZTCVqbnj.go_kPGwFx1.NHwFj6doe86_x.kHrv_uMZwjXUFONQZ.Mx9HAFUBErk3l.Tk5oSZkHo1QdzB1ql2cDAqrIRoIAGYpJ6yE0C89G7DuBZOSVAIa5rU1r4NpuTNlzERsR3lyRDNJ51kGM.oYvhTXwM4XnI_HVcOVwDM79fHudthUIWYIr7nm8wwqY7joruGXm3kXp1yvlF9MDb_Ml.t414Ur3fFgASOl1c5_Iw0lbqTnY_KxidAlKWn1UcLizM5cBZ8QQuQMpYP.JkP7kk5FRzVWOWcUtJzruYyCOCtBoImcjmYkNHHyu1YbjcZfU9ejbwyZukNw3z0Srrw38oie7yefQE9O.8_ENPN6vYK2Ej37hUk6dNrKzGH0kV3fFQYyyFSX9oayPgevT5x5Bbgvh.MuZu_ECMDepb.bkj0",mdrd: "Avl2IhQl2KwgfIzJN0ie0G93Iv1mZNwbmBOKqXRHO.0-1739785994-1.2.1.1-DLuqWqiIpEH2S8P6_JZ.gJdz63Mb9bVFYisU.AkKF.UWjQSqBwSovpDmPee.QhbA3UGvd.uFyG8vE.n6MDcGDSOw8AzQfgc8FefUscfj83h8GA7SFRWRaK1tYKM0DBPkeUoLvhm74gtqUq_FSWZJpwTlsTrc18HlRqRVMaMiw_fCDXWIy.sYWHmovG.XFYKWpBI1Hhb78EKe1xgnGWOHhhC1LQ9dv_PZscCQG6sGKEBVyXgYjaxbuBwiZswAX56FvW3Ylc09g9PH6AmNJBLHBLTcjbQg1frtgTdu8Mi0ez7oMPiVvESeXWbQ8xfNTmoKaqVn6SG9A.KVMxR.N6x5B2YxhCH.N7chipkBbXMC0aTkltJVYbu40ldoXqNulteKXRtO6ReJE3C96Rle7eA1P2jRf70DVA2dsWFmyjB8oF7Xs1q1.awHGkqjqP8RKgHwRmWyHtaaAUVyn.yq6uySvCkSMMG_P0LYr0bqYFmLGYNNo1cLYzKY_UKHzB1Llg05hWQ836.NwWVQV7Wu1fTBei1RIrt_zPfojAnwqcmp1qhnX1xaHwaN8CPNxxXUVd2OQSHqyuXKXp47etYG5hJ.YUCSvKd0GA6T67_6Ww69EV_0mcHpLE9mm2_RZpxiOqYLjSwnKNkVi1K3UYk8JqCXIPxCl9FlwjGQWmlwQNjTa.vWgUKvot6L3uypQ5ufIrxFsRT02H0tSRITw.DZQC9qMazZwcmdYfWKw68gGOW5._ZBc.K58aXGHJ7mMqsvy6mM8RehPHxBsHy8iipJFg_ABP63ydXIyB2NlPIJYiuF6txNVakoYOt9IQZRQPTcgQZDSbU5YcNLYt.BNiX2fwz5MtA0oti4ihKuQXXC3e8_clvVSxjIaLUnlZTcTLm55BUonVZXCkZUb_RQU4lQCiZbJf6jGSpVpMRJ.MqnbmjI0G2d2Q6b74uzzFR1uMHyE72wx91tAAZibdXebUnWkrkGOg5MuJFLIEWDgGLaWEWyh9kceXr3Pqfutjyh08Lwy3Qw7mot8SGr4ZV.a_7KUzKKIBPVAuAKBkv_vnYF0MVEQSqZoKTNE6tP0LKlVcHXFnQyqVQzRKf67i1PfmZ65btdKj4pJpT2asjbFzY5.1ELzc6NyrKlLjCV_Xg8sDsrym0Ai2o9FiY93lBfWa3fe.3Hnn4uRaoQCQk.NuQc3_2g5TvJTPgLwGQsCMqKDvBN70RO7MxTdcNY39I7lLbT2WTZLH7.mjx5GRgZUpWLNG9IwSaY2Uow5WnaJvu3QbZtLz8y.CSe0hMXdkQkqEfPVHwW54Ja0JOysRuGAkekzW2UCanoFosq9V0IoflF.9k1OYEB5z3RYYIuPlLEnmFElWqqvC4cPcdui7M71nAZl6rCRWSBwUNwzW11.JDqvqDQft4V1q.oJ55bl2C8AcKXJ4QtaGUH4FA_1AkNoTd7tuSNk80locpNK1c_z.pT7IUVDONqZ11WX6SA.i4nB55SoJQafM7NubdlMTVbUelBYDyL48RRL63dJwMwQH7iliWbwh2HT4Ja7Y..L5GHiL.EHYxgqoxfResscZLTyOd0iXrxoO4qK3OxoX7q35tHLJWzrPL.DVMqPjsnGN2Jk2WG39gxmgir2M19jEOSWsLgcd6ctPNhuT4ItThp9aOE8ngmmfTqLyXWqqv4f3namEBy1BGiPSbmyiuqwA2u2bOqoNiq4TCIpCcRkV_8RjNHeZEKL1Z.E.KC9O1G6hO5eEUvE01eJpdbB7JOGdW.4IGpL56Asa.wzkVQkWKJs2Izle6LTK8oPxBz1uU2AoxG8Wvt_C3cKH3Ri7pQP1TDd4YB2ebroR54eQDrADPvzTaTnoashqRZTN6DptTsD.tPBqaF7RONyfR5z.n3UyG0VCHMttUBtRZaDV0Hu79vMsRT126_5JCbu0eitYjUdYnNPMiiieycD_bIq4yhCsoYQ91dZXNn2pTmM.9sbnI87R_Ml8E_0MNkbqgIiLe6sbFMY4mLRwm_Pw"};var cpo = document.createElement('script');cpo.src = '/cdn-cgi/challenge-platform/h/b/orchestrate/chl_page/v1?ray=9134e3a34b41ce55';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, "\/abstracts\/search?q=contrast%20media&__cf_chl_rt_tk=L3ywRN82lslJVeOzC0kCAKgqz9N8uRY4mKrjspzXYpk-1739785994-1.0.1.1-vEYZHL6Z_uIojfbDrmmNhX.yh.NIGkYHMmZ_kQ6Dt1s" + window._cf_chl_opt.cOgUHash);cpo.onload = function() {history.replaceState(null, null, ogU);}}document.getElementsByTagName('head')[0].appendChild(cpo);}());</script></body></html>