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: '9134a6dc4bdefe0b',cH: 'KaItOcSgO2WYjKcoLYgVdEqHyt9lhdPIBNy3cbKOb2A-1739783505-1.2.1.1-F.NHU4pxmOzW4Br1tMBo5U.aCof0e02ccImTl8d9uKIj_gmJXX5qosU86vhma_i2',cUPMDTk: "\/13147\/apa?__cf_chl_tk=nUNM6i4Ijbm3cFlh8bSW26z9DAqXOEISVWDeuwzRDM4-1739783505-1.0.1.1-VU.7nTFU1_Ek2lIj1JgmcUf_bWNXV1JS5PjcvDnQvHQ",cFPWv: 'b',cITimeS: '1739783505',cTTimeMs: '1000',cMTimeMs: '120000',cTplC: 0,cTplV: 5,cTplB: 'cf',cK: "",fa: "\/13147\/apa?__cf_chl_f_tk=nUNM6i4Ijbm3cFlh8bSW26z9DAqXOEISVWDeuwzRDM4-1739783505-1.0.1.1-VU.7nTFU1_Ek2lIj1JgmcUf_bWNXV1JS5PjcvDnQvHQ",md: "vv9lu.WAn_ugBMLfOEdz_5HAISJ0vZVQG3ahX26SUIc-1739783505-1.2.1.1-zetN.UqHH0f3ZowdSvlqF2nXHNgE_eMg5XFVy1pMA2me3rQ_wyne2PtKXvlNU3.wiEA9_cdN.kp6FmQ_mx7yfGEzYJ4KLX48.iLoldjg0rjxYdBLx1EIfKpffx1lhQVTVYsgBl8XCOVl9EZIbQnEwrMi3xzKNV8TDSLKnQfhiGs1ZN66xxMJhLqhw1vMaICGdN.SePZ5k5vKyptHZFnHuiOvs.IwjegirD1D6YIBiIIBqCy5NTBGvCY7CHUR4igYQ3u1qI.GHUtVsU0o805.HJfFRsYmlbP3oTPiYGiR6v8rWC5T.PAtkqC11N1D0DGYXCJ0Ewp2O1pYguZVeG4h_39AtK3QaXU3_zGK002y6HZc5GY_gfdPWK96lQd_bTkxzYGym.C0dRZoFsEcwAdhu_OXqBHLmJgWUNjaXiYFzAapwPBvVsqAcqD5Ir6fTO7Jb7VOYdEMMoPnKCKRdOQspN_hJOb6fOG6mkMt2SqiMRhwSs.u2BkbWO57LLjyPBtq5xaPMqFv6EuhbCZtbzyVwM8sTN_QcbFIBHBuEpYXIylRswdeghr8FepiR77KoAbIO_QNrfmUKp0y06hOnNY4aIlQz0Rikq40Wkb.Kjnz_qBJKsR14HtkasFrujc9AJiD.0g_3LQ1u41s_Mt6f56qhdPZUOKa0qDygB41sKdhm1PS5KunHzH_B.s.i30cSEoNN2mZ7BPT2i565D_vyV5neDFz7gGqtJ_hYkdlTZ4tdYbdfMgi3lXC2eBIzlkc_S7CeAtQwr41bkhyRLU8s4z8d8ipj2XAdz7IVGvAr5ZuG.3WbZpgmI83sMniNFC9Y0EoWNoL0pgvtw193Uvpyy3WU.iWs2SXtw3_ir88G8cC8tR5MCb1kkbgQHEF40HuuctPWjKTZXUvQwgyj8O9z3GrwgtoTeX5l8SVXBX44SMoVazYYctJr3AESFlokGb2y4i8ACpKaxhVSsTVT1WVGDlv2ErIajo9Wc2mblsCoNeyEtYWJeQNyjVJCivV0YVbAQEIpzyNUwGlnBcMEsGIU.o1tUJ88oJpf1HI0YcfAQgADq5sXpZeikiNM9gDZu6MgEJKxZRd3pJrnkmA5CCHzF4GAjHQquH3zFZ5ZijZA_4H7Or3uzgM_6eRsfI83SNGMJLeyTuNhOVjAjuN0E8yNsSxZre9Lrm8F.MlymFoaSS3oujkp0RHZ0k1QOyI4Y.Y67399SYijlAT9WO1aoM0JkYnFoSKljz5iPPfO9rW0qcrixgO_1It3h93d24veSMK8zf3Tgh4FoT4P_a_RqgZSfMsBow.1uqCXhjma2wgUaVt9q_Ajsu62xm6m0YV2xeeFj3oYmFYjtJo4px0Jm3IR38ANu8XxhYEjZicEtPY88o3aE8UFaOaPDMINCViKcWeE9TRPZVNc4NzqTLvjw_sZmRAkVinJXXJ7009IQ0KxmKYR1PX6RFBd0WePjqt6JNFZWUm94mUa4XaoFS6T1CL5.2P6YkayBoqcLIOOUNCW9G_i8ThWnxX.Nte_euLLDG_mcF2D5tdUdnI8QkispJu1hbevIbZsybftcU9MEub30OXTZlbBZUs07AaPj2I5vurFEthLpZd6CMxCuAxD0GBpj0Pd3Ot_jrI19Q0JtkENG3DcDq2Ygx7Hqd8n8__SytOK0lZMliIiaH_lAhap_MFM4un1ofcrHyu5UJcm1tEsZ07T0jl9rzXUEOOKyFrWVUe5YlKjRmPB5z_yo8h7GXN7nZX45irl5hLH7GdYdr6hEhSdNi3mK7zTw4kkLx2oGZR206EGJkLC0i1NcC0ZDLRQ4nReUDCgRAB07zfUFLjUyGf09hQ2hxTZTg6Q3y4jHTh3rO07lEl8isceNKAE5fBorgn3H3qDLPRG9Tn8eZSG5235xk",mdrd: "4q1WvhcHFoZAhsyXg2Zd7LdESFqBGOFQD3Y21Q9C4WQ-1739783505-1.2.1.1-Y8gc6Z7KKYuwpjrTnrn6RKIRiTUdFKaOas6xTUDhhLNsAD7ja6F4dWOW_Vpx164B4qBx2RZvjCKR3Xe6_l3rPAAj0cMcbOtrH6D83X8pBnR84pw0mcruITXCRsxhfnUSJw3Es00lelcmoc8zrkr9_p6zBBtbRz11q3xbdHx.x4U07kdRV08f4NDe3vYQ1cpQQ39W9wsUJ.HCOx_pVwT80FOr9QEUGll_AwBuWN2tiRcW8ZdpAFQC7dqBUGsXUz4tQsfSXA7AgtDS9I6Akj1e45.tlKnTw2I4ceqgU2uViL.kLAzlOEcSZ46bLKzSCPeabvfdzshBEDHYcT2aBKZJhGPCBdm14mIg7iLCaoo0xDN2zyjw3ii6YjGypvJn1vFV3RldNLgrfy_mtOgyr_1G0WhmmCLtJU0un1kuwG3bnSaWYZlxYg.5mVbilsjxWHOlr2DSX1QwxcoDP5OUV18Vme2epcl2fM_scHAz8epCIISgxD3v_0XTP2Rnt4xixt45jxwe.iHi55T1k9cf3DU0wkml7BcMc316v23VQKy5QD0PEYTfZOX5oqprAeBkbF5ouzADwS.Y7Idi2QA37RCBaDdRrj2W0VtnTiOEHQv8OoN4xrvTd18Xq5cssIN6IxZmZQpDWBdVjBrYI0ezyGNcnzsfGSG8cxFY8ovESaa9__iIPxKDSXSLsCdqeaNPyEPPGVj0Gm8NY1zaVby_GgvxWakKDAV0nEqKHN7mzuSoMPzPL93zMCxhJkICmYFT6zZxh5z1lfcXZ5q3e0zCCqwdUsSAwUNvgdsXc14V9UYFIEjso6l0mWYZBxQ4eOxUKHhNjp8geQ_LxdYPkK1825ieH2WtSVyVkC.BU16MVc3WLScWzmFjkw7NYn0PW3dsIcqmAtwYBehlqtY8.1r8cVMl8QUYIOVEPk6.uiiAaxQHKza51yCiCQJ0wUZR4W0TLfudOc20N1NpTS4RRbg2Yi035L.R5a_RjZfJ45UxC.9IVyFMZCYfV7NseHLVMqXhmzofjzy.e2ybCASnL_luag5rooN3gwgQ8nlL3.Yi0AutoSHDWlnaEKVIysoeTi1ZNwCdIdxS0sJ1COGgVX40a8eHRzJe95KTxPmk3taSwYRHalikGEm8ifXEp1_TJ6Hykh8eInu2Zta3NjCN_zafA3gpQwDPLhAVLI4ivfdcwibpvcdtX57Hf3U1wziziLlG4kD8zjOIKzSpedpJrXHdnv6dl7smNLhc7t8x9rUB2X6wkxYFSrMTpMgv9QqmrD_mYmqQI6nGIN8CsRI7CyiTBbbtsXGjRB_dz.y6XVHRLCzlLTmwg0qVX4_xGI.9GRsD8AKFKQ3H6u3h17pxFDjXaWfs_I0Ai4LDuanDirzUMMMb16XYvMCbrVGJ1V.aU0o0T4h9FdAk6yWc6hCoz.QlqrMvehwnvP7.9ePT6lCD_QEpzGYUHebQs9RVpTahmVCf7.0wlXRwdf3Lsia8.Khb5f383zKuKXzXyUtPzboK4MYYv6O_Z57VcvO1tv4XTCiXIUpnu56vOZFVPNetRKEu7qPltRNq.N3ORAmRIFInsvmOHyMc3MjkO2w6hWzQlRgQyhiYKVpyTQHNfdHv1bUex6B_K9G00Ep5w4g8HvUeEDqAp6HGuIe7lr8KMxLseTiH5RewBxjeGSIoTUofZfFz1EOBoHudhSjA6W4tsuMq1jcvwBt6z4RLrQoBJ_Phnx6vggJbGbCObB9wKkwO8RhBl1Vgm.pB9Q27SoSGFhm9PAWLbfKTMWrEP9V80FG_kq2L96uUouud310GxWPXeEOfRcULWGrcITA.to1A4YCxcPT7vfIOCijw2Ay9Yh8pXq1oH1IRncQ_eFGWYJhx3xpUFopIDZrp3Hpp8Km_84yh1wx.9LuHmRzuMwnsifctTipN.fURd0khHPn4RrZPZsKLrTTaoWgAKfV0UxJBI0AgfJ92IYyeBBATjgphLLTyQt_iNeJI0sqZPahPARjmwhKwTylMIw"};var cpo = document.createElement('script');cpo.src = '/cdn-cgi/challenge-platform/h/b/orchestrate/chl_page/v1?ray=9134a6dc4bdefe0b';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, "\/13147\/apa?__cf_chl_rt_tk=nUNM6i4Ijbm3cFlh8bSW26z9DAqXOEISVWDeuwzRDM4-1739783505-1.0.1.1-VU.7nTFU1_Ek2lIj1JgmcUf_bWNXV1JS5PjcvDnQvHQ" + window._cf_chl_opt.cOgUHash);cpo.onload = function() {history.replaceState(null, null, ogU);}}document.getElementsByTagName('head')[0].appendChild(cpo);}());</script></body></html>