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,PHN2ZyB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciIHdpZHRoPSIzMiIgaGVpZ2h0PSIzMiIgZmlsbD0ibm9uZSI+PHBhdGggZmlsbD0iI0IyMEYwMyIgZD0iTTE2IDNhMTMgMTMgMCAxIDAgMTMgMTNBMTMuMDE1IDEzLjAxNSAwIDAgMCAxNiAzbTAgMjRhMTEgMTEgMCAxIDEgMTEtMTEgMTEuMDEgMTEuMDEgMCAwIDEtMTEgMTEiLz48cGF0aCBmaWxsPSIjQjIwRjAzIiBkPSJNMTcuMDM4IDE4LjYxNUgxNC44N0wxNC41NjMgOS41aDIuNzgzem0tMS4wODQgMS40MjdxLjY2IDAgMS4wNTcuMzg4LjQwNy4zODkuNDA3Ljk5NCAwIC41OTYtLjQwNy45ODQtLjM5Ny4zOS0xLjA1Ny4zODktLjY1IDAtMS4wNTYtLjM4OS0uMzk4LS4zODktLjM5OC0uOTg0IDAtLjU5Ny4zOTgtLjk4NS40MDYtLjM5NyAxLjA1Ni0uMzk3Ii8+PC9zdmc+);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: '913690187c3ef938',cH: 'I5JRXhghAask3_Mpl4KT9HGiR69uAO.K6B9GtTHk.No-1739803544-1.2.1.1-sb9WPHKeetptP8LMmotX8cSkxasHHGOANXmdF0pzr.w6Lvn_JnYfKXh9qeyVz0E9',cUPMDTk: "\/search?q=W.%20Astiata&__cf_chl_tk=YXdILdcnFsGb0Pczaxr5vYvINA2cdbBUWVP.5v9b3ro-1739803544-1.0.1.1-ujMHGUrrmQhrS9xPZ1syxGYwNsFl9ArO2tBDtDYVtqg",cFPWv: 'g',cITimeS: '1739803544',cTTimeMs: '1000',cMTimeMs: '120000',cTplC: 0,cTplV: 5,cTplB: 'cf',cK: "",fa: "\/search?q=W.%20Astiata&__cf_chl_f_tk=YXdILdcnFsGb0Pczaxr5vYvINA2cdbBUWVP.5v9b3ro-1739803544-1.0.1.1-ujMHGUrrmQhrS9xPZ1syxGYwNsFl9ArO2tBDtDYVtqg",md: "qzspMsEhdkj1Dvve_HZ6BikTrWbMKY5Uy8bCVMnCn6A-1739803544-1.2.1.1-TKpAps1SpGza.WkcZd3gBvzihLV9kuAxO7nc2ZHT92jBJDRxEWLVJoOoIPxAjkvo30xBMGHhVlD6UYLEEtVFclodghaV4fM1UblVr5A_x_BL5UULHBpkoTPtxo..19puvkYpFFdRX572cW73AC.FPYMrIrkMRGT1CMMaUttkSYHnEkkJgE60Pk2NeiUI_yGvsSVwMGLnrBDN47rnFQKcXYOsYk_Hyc87a5GTsOydQ0u0yAScCbCtRiyC4lZPKWB8uiFbu99ww8sTpugg5_VoTYPlKK9yFNCawl92Z.hImP03kzu8zk5icgPzZXz52YsUC5RElnB2stzfCn_SDJCYkQZCEYro1yR.7zr6O_CXxheqk9F9vAuww3pwDV8zobzamgdMj9tCpw.DKa_kpAwlHFghPt7NvVPeWFNsFL.XLp._TVIZ9pkhrMx9lUIAFiM_9prXtzAUt6mDckJ7FRXpiLqXTqEnMEq0D.h6KCOIk7rzOH7H2DW_LcnmkbpJdkt281s6V7MslhvdhOGWZUl8kQnlno5o8Kdv9YhtOcgJzpnQXH..WeiSfERt9I971iH8fPppYDgufdyzd8iS_1NJhAhag7lWlrxNypjhSiBkkr60x4Vln7Co7lzRka4n0CZdStBvUfe_oOultCy7Zk48pXgRmLkWgD730346cjTvCD5.PIcPBVmFFYoF7T8YTXVMN13eLnsfUCCueOSOD1HxTO1gxdKldu8GdY3McddJfBCFlr5ECCslPkQQvnUVSPNux9Wj_bswH9nahVOLf06YdOjVgNW2AwHVE6bcgVJgJH5r3mL0E5QAuDwig90RTH60_IjYGvr5znuCvowA6x_mq6ClqZBX3u5FvXtq5g.YMuRvIm2JnvP9pzYT_8qnPGE3q_gP2Yfe3KnnTH3lvXbP9EsNGLVBgvqpSbEtt2Z5p60g1lFAVb1h43suKiMK2wQisoOyTAxkghGJ7qrpocX5oiKDN0LYy4NrU4QRjhhiDyFAaG4ju5XKLhVWx.i3g22CPMwcPEOJflM.MSrrFjDpBvod.3T82Y.ol.xRJaCiGonBjGiplWSY0UB2lrcbo4583fuaUXXC8XRKi6ukQCB4Idaha5vRL_F9TVkwsp5u0r83jUXkF9sil.eFqYZTibE13TvGvSUWOYWt3j5lJsWpijn0dAqe1.5t4hvlfSeRn5jpNry00VU2reo_lJov4PymjeMTX27yz6K4M4Y5tQ9Wg3pjJho1orEay7N.Ik0xmq.izRYJkayMbaBimETPYa_rb4N4TmmgYG4qWTQSLAWMhVfnHURErhIYGNsAkYLLucKbFjVvMMZhMtvATziUWocnbW35SYZQ6PgmDZwXjKVUQdNRuGkn676E451t9C_EJwZPKkGXmkh8yMbGHkNgYf_OelkDtaqlUrXNRuvDg4bF3fUqVEei5po7m_ekGi_x9oNk4sk6LEr9Rxo99QmQlhZeD8DwF2AAjnPt8clWqS_WI62lg0dnV.mJFOz2fHCjj2nRzAOmVtIWRh7sI1pZHpg5DDpjrn9qxRKGa7_El27TozrKLN7A2I0QnDHI6aS.kr5ObFmtEfSHGzA6vrHuo3OaCfear.r6wTmy4OXt6cnaQmfHWtWF6fSePsR6XHgi.w2sOH6YZkOEfKO4.Eef.79Y4UCdnUqVCkHPn_ixDAM28De2QlENVYvgIZlPKb_ZToNkvKRLtVli63cVj5L1UbT4n5Xy9tWHBVa0kFCQI3_PyBsd.BFQo.uc6kVp1IDXfaVWW6X3yprya46yDxFGPtgg6WABTqUr17Z5PVP.0AOG386mywFopIjkhao2zm6biOfcCxRV4uD_mwke5bWORX2EyGP8I9I.w4hHojlosodFVLI5dHmq9M4PgL5DeF9KYsEobpRcgGqQJC6a5EbKUyLG",mdrd: "VjWLPxJs.Ap2Vt_YQiNe99WbqR5he7IBZjudq12QkHM-1739803544-1.2.1.1-LlNYO_Ug35lqB3mKM1KYGZZNUARDqrf7CCMHLt2DqorEJhfcmrWPk54xzPNO1cxKmh.5Vnr4ledzc.W9jsuFKomdtn7k4pA8e_eBWCoPk49dLD0p3oB3zk7GYX28remB8LmkTZZXfBVAz5A6D.AycQC8I4jwr.Oy3lNZchhe2bvnGEZu9F5kWkln1vt8yyKNOalJ3iO0E4tznwiy1iJdcf5qPoU4Ua72O1DT68AcovJU70gsiYBHEpMKxw1Fl6ko3D_97VzIpZND090OW0dPM7d0HS5oRFgcegK0_OaMjAaPtbAHWMP0qoFu3FQXQbxIv9o0pYf5Auau.S4mqXDSaoD4jXEZIRXSrBBF_P9q7_2ESa2Mmeqz_4_2A9NKBlP6a_NxfKqRYf6UBtMK4ULcLiSMFw1h.bztShqkCczL9KTcmOsYiQo_o0kG2aLbiqAvrYXhmRUocf9Foq1T4tkzTwOpubLeDQKrB2PRsT9co4WbKemTzv7MnPgmlbNR2wmKP8VfXVBUTFjaeE8t.YbjaCCeIKC.ZY09RimcxCfUheFf._B1ORKHMDoK9QF42SVAPNR7Y0L255Xzld97joWRsHNjMpowZCrJnCx3ac4g5XH_JFpG78x0m6XW0q6q8NmAZWuK8i_i9BmlZHuapCm75NiYKJ1Un5bz748u34fMjT.qJoYh3xj1SHH9bPKdY3A3es9TLg791KnYSwH8QnR_cgLd8R1c3ZpjpgNiYg53uTdmMBZUB06z0PQ1K2esKaLKbEP4LYcIcgNHwc_ci3jC7sqO_HSYU3Atx0LWDeivsG42BCXEdhF.DVVupjSqGZOqvBgEhieo_N49.EMGlIQIbcimwKHGSRcphLX7WdukMfrdhNQw0UKLsJSFQer36mv6IVq9w1Uk2nQCiFwsJtLQ.T.wAaPdeVy0z6xJnsRcAHjP2pc3sy3ChiKJYqHjlh6BCe.XseicgA5M2eByC_rhkJgKLkoeJC_mqkhy0unfn5fykwj39ij5m8P._uNj2xgCJy0qmTs87vX5Q3R8H9AoURzsD2vKHniuPbJWB24ihsnGS6XzjCh9UbMSLysRFaJPIOc.G0_lqle7E2_CbBqxGdUOOEgnCeimUgU26PRBMf_MRygdT2bFv3K5tvLou8nXTyioen52Xu5rcw7Nkq2Jo1ztODlPesFrgLv8O9CduVJpx4FEwwX0Ip4egco4jpyQlcWRZI7EJO1XWgehxl7OKUrnRtBvZFQUEmhrhRdu0izj_h4uM0JBNWvLOYWZ8YQghLSN6wz_H4_ytsL9pOI700A7dKQ805zNck65SvWrj06aswI.6Y5Q85Ak7oMRQ_P3NS7ZXyTbdRopW2wOcQW3jz2O7jQDP0ECWdyo4cBQL1A2lgxw8G8xBN5WEi7KpYpw26u2RtHdtBFoQDdI8MCjz4K1Gt.DKPK3usbFFMjvkv4mLqgFb00vM8aDnc74tL525iv1ji9X8eC6u4dBMInIFfX5ii7uax2phxtfjIsvpascU1MJJ00d1FNGs62roA9RHrNV7c35D557LIBODRccsZSO8uWx8BUw0nvlUCm1dXj2NIvsiXTClWqDbKCKKnHqfFHXLzk5tCnJoCGVSkkuOhGBZpY5WNFmrF1_4wrvGAKVcobe4vAjd_WYkR6vZgAF0jq34sDJnYCm8jQN6_Bjt8ALpXieV_gNGHtK43decKurKo6RjGCxJsPTcxP5e.2KggeU32A2ZWXe8oFzwXLwYFXtZC2h4E9T_u3eOtE_hDw_GN5vr6P3pggeD6g5T5ER9WjGKGe57pii6AX430lOPLJJ8Am.oKH00HpNXoBWSf.qIv2CQihRtpBFIEEH_8bMP7vkBGDJkaB0k8_hoM3JkkIRtuAXmw_NZ44koAoUNsxo6j0Hvt0kccAmoa4biliCzVm..gMNMPhbS0Rih.lg1uwy5bPVBBgwn.M0.2LquQg_odn2FbLOjEeWMbwS7l8zvYb8_Q.h7Fqs4sxsuDBhdA"};var cpo = document.createElement('script');cpo.src = '/cdn-cgi/challenge-platform/h/g/orchestrate/chl_page/v1?ray=913690187c3ef938';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, "\/search?q=W.%20Astiata&__cf_chl_rt_tk=YXdILdcnFsGb0Pczaxr5vYvINA2cdbBUWVP.5v9b3ro-1739803544-1.0.1.1-ujMHGUrrmQhrS9xPZ1syxGYwNsFl9ArO2tBDtDYVtqg" + window._cf_chl_opt.cOgUHash);cpo.onload = function() {history.replaceState(null, null, ogU);}}document.getElementsByTagName('head')[0].appendChild(cpo);}());</script></body></html>