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: '9136eafacc173fa6',cH: 'hUOVP1MG9ABcKSF2fkf6aL_n7_Y4.fsVl5TCK.0u4Jc-1739807267-1.2.1.1-ER3ihEsc8OPcjr2t0z8qAqDU_pS6ABNkIzoEV854CDtPav8CjsS86FKfbCE0GWkO',cUPMDTk: "\/search?q=categories&__cf_chl_tk=Q1PL9WhSlLHXqNH.voMi1Xl_EGd9stMQXpTs3ewAVxc-1739807267-1.0.1.1-DK0bXP8.jMi8hQxX2b425bttQWqcYOH9bSCZQrF77VQ",cFPWv: 'b',cITimeS: '1739807267',cTTimeMs: '1000',cMTimeMs: '120000',cTplC: 0,cTplV: 5,cTplB: 'cf',cK: "",fa: "\/search?q=categories&__cf_chl_f_tk=Q1PL9WhSlLHXqNH.voMi1Xl_EGd9stMQXpTs3ewAVxc-1739807267-1.0.1.1-DK0bXP8.jMi8hQxX2b425bttQWqcYOH9bSCZQrF77VQ",md: "ycjv8Y0Xn7n6V.GtXe9c4Xq59.mI2IE6Geqqm98KVis-1739807267-1.2.1.1-2ItDM16HYWtCcWs6uXmgQV4Xv4adgfK4P0ZtIOEMPF2nzsIG0n3AsxmAMamW5lnn6UM6IOdNeZ9YD80Qbyat6SKHsJgXehNENm43AmP0hNmjQ94rctkC1Jh_F0cVRYB76shseThnLriOihj33zIns5BWfZ6.WTD8pcOKK4ZB7CHQkpG71SNIbqL1py1OKgSimiWjYTazOMAYxUffOCZwW_MivcfDcSKQzeTvZXR8s_tD.hAT.v17kp24X0Ct6vUyv0JvCbB_AcCgo8uwV.KuJYZu4yUjGEoktO_E.ej.9d4G1kboOyo_m9p6XJt4Zg5m6hCdJPIJukiGC3fpgm37cqXE8TtFmKHoYoD4ue4avgdvj8KMM1DAjTj_ljWhxHuI1qfefsx6gFt62GNseoBPI8QcR03z6kdmMVnfPRPZ8D25wTxxSZc0G8pa2w9b3Yb1GcLW2FW.KqLnVaL_yJvYTh2jwr0aSuC4B8FCzAgicVxVUc43xspvP5A.C0xLp9F0FgzLLooytfBRgKPy33KZ_XJn4TG9OwGhfAIZ1Mez2Vh3P1UxKt1GI9fTC_coATcAdx2u3_vBuRHIvwsbdCiDm4.4iIRK2_zdsUvm_rnLxNG10zQ772IqowiLqUhuadEeXmd8vZ5GFPv5tdO6uBeZVXCZaychn4juXKSfbsab4BQzb3abRQrcD5LdP9nAw0MF.d1gmMbKJalrLxk8LYd43TYgruuDgidNdBTn1azdF0Lt73PIrkNS8PrEU4CQYFmNAWGvvAN6DhnSEaTxCAwTbotWQybXqcSYkG13tyQ6tTFbhlc_E7j6z1BibB2S.CuaG6Q7fhFSqi2LXgyDDN3a1EyS084FHtZZmamvnOEbjRXvP.z9RGuKdMznIzx81tDyII_OjqONmF.uEYv2SfMGrvG86tT9.lcy52mC.Z6k522dI0D2qyMydZlKYY5Oua57a4cKJpoqEZa2SMeKntRtotS1VcaSCSQP_8hdOVJrcSEeKoU2WsHGcX2p99Z05ZNv.l5CgF89H4dOxZFh74g08MAfIlnYTSTtCzTcT21sv9myGthiWis8_WU.jxhyN3RlZ.g2pxFamsFp.oyT9ab8hAG0jz_3zZo2997VwF7g9pl5w8P7Pt4H7FJKKHBmHckg2PsI1EcNTlfFTREygWIHQs9rcnEzg7m4fTGqNDiTnwde6cizTYEJFgdhfsWCEIv7VH6aFCHo3HWpFwpf8RQ4Pyy7I6Fp1Pj4n6U7jsoBmSCGe7MLlsL5DZpRnf89bLy9Kl0aKHmVTBEvUHNg8fSkcbfrc3DavGMqVp.j4iaLW3apx52E7L4ccgwRwoke6pE2GvLK3vprD38D2zACHJWs59RXTgDMFQdRCD_hztbPpTN3Ryhwc6igI.WeQvlCIZbgCxgY.P7aaqEqSg2Ie2rfQGTevvmlW.GbDTYxo9KvhNK0w8QqsI7bX0I..rDzszsLigssyzNKKscuw0TZIQLs44EuqUKgbEY33eus9To2.vfvuvud2h_lYb6TwggcR0_S9jYM9Fmq1SuduVewbJQ7UNO2FX5nRS71e6YsdJDHj.Z2DdhCg.E0oWaJ8zVMST7JZSa1g5cdg2fe0JzAuLpeBpms6TQg7OkzhnxAnKcDWFihhvfNylxO0DQXV_83XXCTtocfg2XL0Bt6O88530tIUWS_lqefkf2ySf4O84P3Bje_ku5LRXawy0Zyfh_5lpzNDN2Jdg800MDXrgO3M24BY.58F95mvSJPQnWyt9pD4HPSSr5qz9r8u.1D2TTMZDf_4Mt0m02N_335r2aKh2ywIsvsqYrs.j3mnIL7MsT2h7FgRghZfEX8xLHZ4dgB_ZyqO.E1U_BssiMcOY2.nzcb7572zT6bSwn6R4ZMvL3zXC2lXKQ5wA9FMrYyX9vAjn7g",mdrd: "eIDiBG4Bjf5HD9vlr9CuPgmf6ax22ONZ4RlHnFg3Qbo-1739807267-1.2.1.1-3wNjyJ23iDt5fZh0Na0CQe4jdzCQV2mr_bcMwsKHVkmgnW1an88fHfJwIyKowU.3iTGqsCeMYUzaJ.Bcw.L8PietiGkZRsvgPDIp5vCatNW4zRAirkQUf8nTV4d3NrNsaoUNk9cZlmuQWSsM3AaCZSf4aZszhB42tPdPI_fjsGr6rBVvPqpCeeKDED0YH5wOTymdFrORVPXGk9ie7ZthuQiHH4SC_q3aNKluF_IwB0GStDxbv.51rKorki8hjA.QZDPHLv5e0f4Qg5l7_fp_FrsLjWJ.6Si4Pbt5.NGJEBHptECw_9Lb542dyut0RlZSaWRvbLOtHsdI.9kGNaX2DutN7UxnHN07e4uXi4nZ32rA0l6tNQ4xVvQ1yqJwrC9.4dal.IHzwHphL2HNMjDLv66rEdhQryI77zogBI1jycCSVSlZgnmNOc0oWB1_ML.FCWSpQv7PRzceOHg7PxlP56sSh_UcnFdJ6zI1UfhsoMHm0a3FiV_L.3s_daQKeQBQCQcVX55M8s_Tp4hxnz6e314tU.lbL3SS2oI0_6zmlm7suTULrZcfGVPMKaozgKt.nQeWnRJFyVX2.6neYXxrlWDp2ztQ6tjwyl7fA636Q705SvjkJEiEucfikAQOGworqXKoWZRE28cO2jrMxmlAtrCueJLL8fbpFysMh9v7.EEf0rtHoO1xz495QQmTq4OlAzrzkjMwhk5NkobwBmC2WzUZbZja7EqXs5ulzIaV05.Cid4wS5pKrV0ox_yTHo8_uAUW.3pgYFiXGxkWwKYWSDU.6lnrqR.i9KNi8tSyriF8edkJ.nf7vLtcckzdZZFlaMxEzTVF0yYIyxWhQNklU2dcSfG0lndBmjxde.Xnjzxo1PZ6yDwcIIxCizTQizfM1u2G.PmhWtVZAVg.MpDD9wdcJaTWQHhIunlobJEhsWKBIH27HeSCl32LR3lHNv3Any9SAefr.qC1yMh6ZITe5xb8XsI85Ijd0a8tYB_3JYf7kWqbqsIIrVbAsJf9BhlhBcvUWCBpbap310rPwuW1rq2SzfHjL7kVIesaql0AvulyInNro0VjA_GVUkVZVFUDGGVc1SJ8r6oAi3SZQQ58X.dV2PFwR0US5LNzvn.D0_m15gJ9B8FvodfWUUV3Dtk61Ma3TrGx.z7Nivow8jzucIoFV8P3l0iFfNw_V6YyE746.35liGD1XXphshtgZF5z.7WWBsoDV4.lQmVKiW.hgk7OblaDRuvMUQY4syaREXyBxQ4eyioz9C4uUZ.M2XmGmGEmdrfGNF_9IGRyWIaj5K.rvLflhuMYkNS.PPswAKWq7EoqYKyDYT4_LMEPvoSR7J9gLbu2aetAnXuVOPndM2..Nqurm.d7OwUxNRDtz8BHiE.t3HHPw8cev5uIKn0VObjZOft1LOwJBz6HMxj5ljHR6V9ZURJcvcZRtB8W11IyT3aY6YpPg2glbL97esIcK3aE7jp5lTIjZCDEv29rBwrTEg6fNvcKe8WC0HMA.1O2pI.z5g7lmDA.QI2riRcFTmQk4is5alJL0eV3t6YYSNh8L5GN.PeB8O56DehB_1eAX_1bl3Ev3_7eQn5wv5MTmQPe4CgbP4URn9SP8hht4caiXHVcl9RAPIQVZ1hlXH25YZbmCpmCKJmxEq1xk7s1wedEoz.YxgYnDBfh8rxLx1jL3KzTmfswWLz5AyIJRZeLSs2vvA7jj_F3_.OFZpi.WTtvTvnA5Y1MUA918fPgvBu9Fp6nWYQa_tGWwNczRnqVn3yiHZeINn7UJ_8a7f55O954OXgNRoBR4o6rw7gTw2kN5TjDTEoq1g7r08ulYfNO9H.AdK936Il21Qfvof_IY7ZpWJp49rCxBk8DmMLGAdbpe2i.p_MLZOF8_ABOsUDDlif.VeaRiJWO53IrTDoleidLKSiE_lcRUlNUZBwh0CnFpYMKqje9jVomzQbqDmfWxkZUGVu_RVYl67xvB4p2mGtlYLT0li.TnifDV8mxZQ"};var cpo = document.createElement('script');cpo.src = '/cdn-cgi/challenge-platform/h/b/orchestrate/chl_page/v1?ray=9136eafacc173fa6';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=categories&__cf_chl_rt_tk=Q1PL9WhSlLHXqNH.voMi1Xl_EGd9stMQXpTs3ewAVxc-1739807267-1.0.1.1-DK0bXP8.jMi8hQxX2b425bttQWqcYOH9bSCZQrF77VQ" + window._cf_chl_opt.cOgUHash);cpo.onload = function() {history.replaceState(null, null, ogU);}}document.getElementsByTagName('head')[0].appendChild(cpo);}());</script></body></html>