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: '9133bb6cc9163f4b',cH: 'lQ8euKSF7SKYYp4mBwapnI1tZ4TtozuLwA1XR6gaK0g-1739773861-1.2.1.1-c8PmF4D.Y.PxfYePE696sZi_qDlgzgam3FAd.MXidasvjL33RIy95immAzv.npDo',cUPMDTk: "\/abstracts\/search?q=barriers&__cf_chl_tk=MJzRiErQ3OKfwZDiKwJ_5mpbhGPEsxZNIxnptOy2xLY-1739773861-1.0.1.1-hfQwhReuo8VQfdh7eq9UHUfV4Q58.8BZKCRPOh8A0vk",cFPWv: 'b',cITimeS: '1739773861',cTTimeMs: '1000',cMTimeMs: '120000',cTplC: 0,cTplV: 5,cTplB: 'cf',cK: "",fa: "\/abstracts\/search?q=barriers&__cf_chl_f_tk=MJzRiErQ3OKfwZDiKwJ_5mpbhGPEsxZNIxnptOy2xLY-1739773861-1.0.1.1-hfQwhReuo8VQfdh7eq9UHUfV4Q58.8BZKCRPOh8A0vk",md: "DHXldPJyon.hjS21KnFkwMjXS67VvYhn97h7EIwQ3Y4-1739773861-1.2.1.1-lP71ZyLKmRvgEdSFRLKdEYG0D.OvdjGxtKccl13gm_uPecFLKukRCdzZPpuosz0lNjf70VRghteDzSMSwieKKupA5Ymp7CSQdUxuG1Gs3t614ruhYwJdv8ZdwMnfTeqNQuqFFR1wW9zXHbJ6jwZh3NBLkNFxCiJx0rd1wr25_Ml6M_cuf7.i7B6dSHS0rWOi49rwyfSs8mCyyhIgbkuglZ.QFDRcs74y0lnaIUD1oyQIqIrg7yiAJlMR0TdB28MnUXvArwr8pOhEb9lTKDiM5QUKqSmlY_EnEOFLgOhlrAEzpIM0AZ4EeVO9EFfpOUmQW63FT.cPHJteJmUUYZoqeqm5tUPz72q5mjXcB4_6fZ_CQzoJLoiAbEVxCwo4VDjImfe5UgjqTb7uX34u_vaHs7k0FLyXOxpxMqdOjAxvm32jpr2zY5zaEK9wldJi5pJRl9Opt_Zp6blOiZ7wu5I96obMgbFZj14xrNx3OO_5jotyiuYUmd0RnxsppaiDAlijniWffgE4bQQz_CZ3XXZriFt76JCBquwzY7K2GnohtNHQDMEb39ysiHtsG_orjvrzkrOUUdnSlQLChK4AeAkQFtKgAth.rrCqdfw0UoMeBhrNCejfLwZwHjvJEEljl_LNGi1BZEszU8aCo4IX3MprKAgADT5qUKHLVCK0bGS8b9S7SIucNDb7hK1m4AN8YIgblGmjLgLTFSxgbHSTpQDFxe8Zb3Oj4snqe_2Cvo_HhiQcV5iV0XaRbZowIr1n6AK25xOWVNweBZlbGViRKZrXZ4hosZ8T136tdtsPHNC_4BmOjOPbqaV8P4FdOCbaaSYuQhl8qJrdYlhF6M0FvAcB5PrVBtHovQbWpgt6NowwIa7G6uRPB1stRnoH9h_s5pq.fFfBtEppA3JTC5lhQt7hxTO4d9xSreZ.19zCikD.r._2pLIoDyrJi3fJXHRzn7yRxauyncSL1HJ9zM3BPwn0leepto2Ae0kQpCg.EDzhNI90geO9FkbvDrpJI0IZ7YdvnxoPgBwprhO1YeZ62G8OBrkZzqfl1fBcVasw1fNQVv8lHj3DzQ7FDzlDhb5_an0i8DTRIKFYFWy5CRlErAhEK9HwLvx0f3e.uNKoLMvJk7Ng2xPwA3XajTI1FSHXro1pqaJ2BS8KO3ts6HFpBkIbZ.wXroOwU.WcnSX9m9X7iLjkDs_wZAmNEjEdzzUMTk7s63kQT6CFI_mbblJBILvHdCxa5MgSSiF4AZz6UZ8KiA8aciqBAPdcf5G2NKpw0rdAB9pO0TsSv8PbEzGIAyoXi0XBkK4uEDk_Q3Q8mLl1e8_bTcjE9_432sdflfRfjbqVByMpv47cnbEJPiDBItQ.JjXq26Zzmt26GTAs6_ibfA9pS7MhlLhAdbtKhG3ArBz5GNP5kGkm5d6L9agfOCkSe5VwWz5j.gCp6z3wzb3.CI4gKQS.5PFQ.HkYBBY7pM5kKRNTnaa1gJLM3ryv2A6qOa0U21bWiMWWzKl0Ftb8QSjvqNvzN.4JOpeMxH8_buB57Qblq3HvQJ4FcgprcgETYNL0coJ9aNWMxdqOt1OuJwu.oAL9TU_ESnSfRmNV6lDDsokF0zoncHJZxUnETcnxxZzSFPb4K5p2lED_7jUBuUW2.jOz2iSFBD1mplhNE2XhKfzKIalgeqaNEeIvmTPPCGUsvei7BWGyVArUEBAqZUKdKQ1iqk4HvVQjy6OPO07ZUWmSOYP9Q8TKjPpna69XAiflIbngg4Mwhns8XLz6pS9Q2QIkRCYBhkR0TbkVr3.xXCtULrURiM6qnozUQMQlt3LAGPcwdd.NNSCoEtvA3Cq3B1xiG9zhCQMShO.hE27hzY2YVOed7E4i1lOr_rpW_Oj904NZ8OcT3AaHQju7AY1z0n60Iy8p7Kzt1MOxifJClvC9q3XaS97pd58qaAMyYA",mdrd: "hYyoAabUW78s07QTT09w0W0gwpg8TfgrUQm3wKKjo9E-1739773861-1.2.1.1-yrXFp7xaoj22zB2WwFlB4N4rsrFA5oR5.uFsOKK9tU17lKyJkzJT8TefYqz5TwM5rW8H_BvMigWLuTvDyaZhhJeFQCXA_.NE9DMdpuOYHlX1nAlqvJBVSJfJs5_4xK3mOT2kTtjsTY6sdqMSPjouMQtBQwZR6hhGzF.HF5BdA1xHawH27i1LkmXe9PHMzgStFVXxDJ6iS2d5ltJQves4iAK6pK5o9FL0fEV0pADLm4VmlTbgXGc3Kkb4AYuDSSf7W0LjguAJ50QSf7smDw6psKOhT.dQsdhuMWBIHzkbl86qF7Db7BHosQ5UQ8c2.pKxkSisYQoB6G1N0oHEv31GY0qBt2kkWG.c6F0UOv2pyGvqd9soG6kJSp80lwb_saIGOG3OnitI9sW1NE3Oo.8LnjzEo2oT_xREPIrGpHVIi7wjV9Rl0BJiRaVXTVXYT4YBme00VrJIkdxXOCvV4jSavOI7tSwSaDd0pzjWpeBG693ihV8RPEhGMfPj4K3H3mL9XZM60yxQU231WERjT0cGgiZvDbifFIaBfxrEkCyHjs4bw1oBCxvd6yc98GUx_eXuR7WFpi5.EK8QGJqjQKjzkXgVgX1pkAj_DHeSgfbgUqqpI7aoK9pXG99bH2Lv1EO6hCapeO.5beApGKm74_LyZVOxanJKKMKXf52cvpvBRsTGcK2VEu52Khy_uzTWrDJ6f2kUmITDpW209wUBqE4.uVu0pXZl6jPHOEYdNLGYqqgsT1umQeGbVk5bM6fW_NMUBbKM.FbV.7S4ghVj4_8bhMlo0gLZpY.dljfaaGg.t6.v4X3Bd33RwDMAYxNc8O7Py1bZVbmHD1lV.9UOt_UwgBWP1Tl6BR24kwf18sCA57OUBMesCuSK7LEgtyQGrlHYcXQHXkmWf25THpPR5ZwKBQ7MRutjNpba03qhfKCfkKcermEpheLmGef4wFXn8LeddrFCcKJHw0cRhW9rtV.Hq4HFq4gG5u3uMrDndut5JjgntLv6F9hU_JepfA5Oi63RjzkKQyZPkVmqCasebb94ew9N2z0iiBf9nnpOlqoPAeX5SWjdQDAG9xy9_u_iQUXUGFPLRNs4QKX5mBC1heYGd5420zT7GEXt8KGSx8auqUnCXh4S3mFKuXk7yq8a7J7_DhK1nZwMlTvIsIP2KT8.LlCKH37SrCc6INABFoyokodyxFmK6fOpTW.1rpLh9jQhHvkM7eSbCmvqv15.uI4astRcBK7i_atR7uJKsYKXVr1lFtaEfjT.SYizbLrcKWLWl0SN2G0HPHW2jBxueJJWgh3qE2RKfVxZx5kgNaMfzK2LZsTUexbNvSEE0Rha_8RKIsKAXjw2IBY3DwyR23D9bMr0v_otsSc1lscs4YDG.fNgHDe3147zbVf67zwmbWr.QB7vzGsBUv.SIrlYyLsMG8vx8745vS6zPhRwZs47TyyXONPYMP5A_UMV831LsZqV5BWiYu4ErhuH98dj5MtF1Gg5_0BEKlMyuukVE0qRd1uyvaF1FD08SecR0gnZ5L_0ubHUitd5xr443vNwjE82EpRJUTW6ZW.fhpjoxxJgJ0tNedOTmetb._OwYlRg_8z5.alr3ThlyrZtJYNFyRZsCW8waNsWiOcVjunPoGMciD8H4y5u4_U2m9.m1N6sASSpbeOgK2gSvsqAt17e1pqPqn5BUPp4Nf_5HoM_2p8ZATjoAtGsCGxXfw1AOkbYm9jMiSu3SHvsH50hfMGtGRgmh_BQXj_bKumECqpX9NyiKbzOL1Q6mc9qywtCQv0iAFkFMjYTVzgYbAknfsetyYcZQL__LqGTBuUaCNW1dZPcM6YgWvK968OwMkzhBDuvjCpvhmkmOnnVelRzknNSHIrUjRM8COZty6MUfzkrlz0f5Zvy_SpReN.c6PIU6qu5uMYaLV1yDOqBtV6dSH3pOarxIgxZMO8gEMEfH1IWB6V8qjAqtRpcpcmeoXaUP98y5z9Prj5ImyWxoJdpZj3.xFqoog"};var cpo = document.createElement('script');cpo.src = '/cdn-cgi/challenge-platform/h/b/orchestrate/chl_page/v1?ray=9133bb6cc9163f4b';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=barriers&__cf_chl_rt_tk=MJzRiErQ3OKfwZDiKwJ_5mpbhGPEsxZNIxnptOy2xLY-1739773861-1.0.1.1-hfQwhReuo8VQfdh7eq9UHUfV4Q58.8BZKCRPOh8A0vk" + window._cf_chl_opt.cOgUHash);cpo.onload = function() {history.replaceState(null, null, ogU);}}document.getElementsByTagName('head')[0].appendChild(cpo);}());</script></body></html>