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: '9133871f88b34cd1',cH: 'R4o464miWuzdnusj5Z15cvDEyKrr2fhDQjBP5SS9f_8-1739771719-1.2.1.1-.LVvThQKueFANemay11NslqyfmWk6Fx0yNfgCZJay1HnI3mTBsso6xQv9a4.RqbX',cUPMDTk: "\/16399\/apa?__cf_chl_tk=8kVkue4fGf3z4Q9X3HDXDP5FRiQaSIlACffylPaX_Pw-1739771719-1.0.1.1-mm6XcIMbAzVK57XxC.s9xYUmKRxg_J5PMAFprasu4zM",cFPWv: 'b',cITimeS: '1739771719',cTTimeMs: '1000',cMTimeMs: '120000',cTplC: 0,cTplV: 5,cTplB: 'cf',cK: "",fa: "\/16399\/apa?__cf_chl_f_tk=8kVkue4fGf3z4Q9X3HDXDP5FRiQaSIlACffylPaX_Pw-1739771719-1.0.1.1-mm6XcIMbAzVK57XxC.s9xYUmKRxg_J5PMAFprasu4zM",md: "t0YmFbKnkwqHJiaVFeTayjfsHD8aIv5Mduc7.cpNUUc-1739771719-1.2.1.1-rgcHUMJKjXMKDH5.DpOv9Y3WK2TqdC.cse3q67cBTaZSY2wZEGfHAsaOASSnfnmM3DCMTJdFctvKP5brVG4duP.k2DescGraMQdbIhDh_XMwclBc6IVFVbeR7tmgQLXpiQqsPlwQRvNPB8wvt66w4s_hMpDwxiu.wn4RH7on2gDQh37QGpNZPH8wN0AlhLQ9lu7boMjP85ZJlx.fLAGI1LnW9fnHGF26LZ.UgJfIhzHCdLaJLBXdFyOoGeRZub97N381wQM1lkQUpOIOY0ygQuRrFg1JhTvrlmsfXayrwSYH6KzBCLNWoi2dSARkkFMoWFh5uaSr6f7sP5xKcOC4MGkULIZiPFvrlvrY3msfAODHfpwyAMKpVxJrUqr.Kl2LBceuQj.TqWjG6RmjfCU18fHx3Tpd.jx.BAjAZQylOe7jJIXY3KcVhcBpes1WbODCoJIDNuBy6wjcByUvxSW8KjJgfKc9xNrlHUchCKDp7jv2hsSsdpQS4yrTpw5wCVdmFpI4_iF.cnGIh9mxzKTd29esU1q2VUrbW3vKQKrJnmzvr_Ox.qk0KWC5bZh3lcuVxTC.zYMZzRYGdzue0b2ELbc6bmOfnvRqK87rhix6u3DkIIgis1oiKDAo6o8mvBqz_tMGZjtzCOYfP.nY2Pb_VlXKJJ.5wNrJZQCujJHU7VcQNkm7XmfWGRZC1P6E.4w6YpaCfApIuTxTa_RGr6s3rNCt.biIVZtmNcFWLKAQtdAXsF5A_0mcxeHrxCdETCh0oRxi0XhCnmCAL1d9SOR6zIq.xcO303tzBBeIV5DpLQkQIIX9FHuW3qxVC3lgMNhgZYR0BSX87Kw5iwKf2P8wjOuExLAElBRxjWYfKn9.XiD6grIdv_pBwYJTNj0iBABdDWsOx6ZuLed1vVdD5Dwx92xsHZd9vqcKni552tQuoLe45YdRvzmwEsiAAg74juA.UELEwXaUJ2zZsTeD2E0WNJjVMjSO_A3aki1vfMmrVtmQa3aMwOFd0OFrPs9nc7eSX.2DeKhQM_O7nb0LjHumgLNZVwS..lsosexSVR2WS8rPBU3X.oG25JiwCDw1P915qguA2FGjCU9MNvaNm9Vx5faXb5qdHBSs5VmC4.ftWKZts1tD3FdJR_LMcZygE4zkxisAZU_JmxehYXkT81luuHJPVLjnII2H6sLOUW6ByCYPS0l0gIvF5xhsc1QrCmfK3vLVi1JVdWb7W81YJio_Sj33zpCBM0s7K.TGrGD766l_qabu1K..qjSSNZvQ.s_3kfvAr3EAFwm_OhQ.6mWX4hYrc84KH4ywYjQ1cI2J9fvM.WsZSJQrUslVycW_MJ420XCrB1RBmKVMBAg41XCPIvOJ3Ast8nk3YalHMAZOTJLLntIHe87bOgv7XbVZLAyPc7saMMOy3cYZ95T_aZvXitxnRSnjQDJa_eX3GqnG66WcVPRY254iedhT74YExanDkXmAwbrWjKZhFRfFOi0Y.Ef1dmUohWNtjUf7C8XO5RtBIenMrODcXYQUb7faBFIhrO2ZD.FgIIc5Bjw3Yz9CC5uPpGfF0N_rJm1ZZG_QJrWqXwG1I.sYWgXbXU69Q2GBznwEmvRdqT8l0RyE39bEeVgDCBtkUUsL1ZYSDdVwMIPlLpm7QDLWFF3mF4.uyZ.aq3FS53RrcK7VawjpS9GshBGEHQKs5OZHOo64LxczZKUEUj8heA2mS2wi2pf.X.raStQIOxM7FjhIrll.eX8ufmA5E1ECZFaufXj.UVSQkbPXHaWshYORJneerbTQXNg_2vLLMebpOmz86uuphCU2w9h9MqQNqQum6Odd31wy9yh5AVmCt1_fBtMbe5.gdiy62.Yu3dM9yGKmth1Wee2DRHeC5bv.q0M5KYbwJJUCcc0",mdrd: "yRnW5bY14s7Ow4sxfaf9kuxtZT0uBdw7Tn9.qUd3fOI-1739771719-1.2.1.1-LTzXg4a9WXVvgcgM2AUUXX_ji2JbaSm8ZVshHJQswXk4QFof_DmvBS1l93toPaO0uBvhg_ywwryNqelbVAEYZtnCru.Wv3JewEhP6SHUbXMjV7OKNKpDaALvU1f3tqFZL21wz078ylG18y5VMx5AZ_DuD7J.NFoj9jU10FonwxHbjBhUr6Mc2h1sr.3wTZ354b3s7GRMCRuGAyw.Y_aD6Gcxfu.RyIUczY.qZ0guILOI2Td.eSACMJ9B1BCn9Ca5OWZfoGk3OSOi_8hdKXo0U6gkYc5pRKc34WUGf3e7bwLl.oMcm.4VDzfozT8TKzjas4Q.ojrGomULQrTO_MR8YpNXC4IT7K3l9OE52DZ7MPrnpq5jbjECQs_trkytUFS77U4CRWFM3Lqlna0NVX7I.iVQDDtJpKg5snCgjMvfRN4o0wp6X9lLde5SIveO5WExg5pyHgSoo90cDRSVfP.moAwUAFvkLMbZLBv1.3nhtWeOynot3WKNVDXPlcyjhRxfKWRu4w.5G4C68Acs37Lr_2FuTK34sh5vsBY2AEgnCQTDzPq93i1c1ZSLoHWGUGMqt1uH3l35Th7TcX4omFD2eW0dTZAs8RCFOz9KVlym3re7e.7b3SB1J0Pgd1KlO.UWgmnVk0qO_HlyMZbIDccnU18Ntywp8eP8_SCMou3LKJjX3zqwXPdDutI9rBef.KoT.mZdOVIqAIBaOWPdOPG7e9gqeqxMaCJin8kPk2ABnA0b3sdiumtcfLI0fzLOTuKhXkSGyBMj5C9CGIZWtT4zlw0Vphf5CcNT_JX6fjMMHQrLoNoJp5I8SUDAJDrbAc4VkGaRfjPyyKRxUCKdJyxvhHj__DFC9b7MfQJBRPtqIrJro6qV56ZzpvWYpcKUex.uwtrJ2zyLovV_ZF86aEhyczfHBPMmZfg8M8ET7a6kqmWKgCGT8ZmIvM3i5jwYYQul6N4bgJHVBSb2hS2dMPOCASzciPsneGjzxj77KeOrB4Ty_xLPyEdVNmCGBo.wXc_ADwwj3Z8W0N9pDX7nryNPX6RFZTp.cu3MRtfk8XbzzYZcHO__dGq5peM5p5itF_y3.9wXV01LqLrXok.nnDgcEv9C1TOhEOz0djCxpXEmVpt7SXh7OHz4Ud3WZcocSlhDwPCvVHuwqTfvHVQUHX7vFO628x87iRDKlOkyjM5kaZzJ2ZvRNrPyPWclbsmD64kCi1zIG.lQHDndqARAWGB5D3H7nS.rDUlECszXXWSIoT_MHf2ZgdYDfsc7E2RvvvuBIeBi4k5lJB4kMhlbQ3jkyto7PZ995KCnEKiRKmj0K_b.8CIi59wdK.t.VGqDXdoPGGPKB4N7Qz0mgn7PEfUnDo.W8qKI1FzIk_a_AuhVe50J5Sf23H6xjAzKTMQhWZoHUGLUhmeffHqEV.1JLp24Kw_1X9R7ZoakFoh0alQYaN.gNyVnXSoBXQCSb3KBxmmsh5GAdbSnp66fvjuONooOeJBirZ5iZ4fC5KUVwqDn3LEBdhxg3S_6Z7NW3DDTN6JKbOFqGN03EwwuXZf8m1lou7Hw.AXV7Zllrfiwj982h5jNGzkN7Zk2ysvTl_yVdzx1hlGG6UYEJJkWVcIpFWefGoNis10YNNjMlQd4SL.fnAETWoNJfasjFYUs5D4_M1KPz_25cx.UPtMD5mIZDc0IoaoBIQRX5HFWX3vv7orOfyEfQzgJcATUgv1aH7DS4uCS7WGNavNrnFfP8AdT7apSqH3kXBGaD5L5SEMuQiWgaUBATIt3YsnFlWzAi5k0dqn7IgI28RxV0shkwKHN9ax4inL.Nt8XxaXcEbtC_xt7dMW2bfLvWN8aDcSs4oOV0miLBQ5sG_F.nXEbArn95ivDdu0XsP9iEMyuBtazGwsl2_UA3b15ILIwPaEsGXjyno2wONXOTbrqFTBFtK.MnzNCuGGnhtV.xze2e_QGiPbR8kaUHgOdZDNUMataQTz_Y7dP"};var cpo = document.createElement('script');cpo.src = '/cdn-cgi/challenge-platform/h/b/orchestrate/chl_page/v1?ray=9133871f88b34cd1';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, "\/16399\/apa?__cf_chl_rt_tk=8kVkue4fGf3z4Q9X3HDXDP5FRiQaSIlACffylPaX_Pw-1739771719-1.0.1.1-mm6XcIMbAzVK57XxC.s9xYUmKRxg_J5PMAFprasu4zM" + window._cf_chl_opt.cOgUHash);cpo.onload = function() {history.replaceState(null, null, ogU);}}document.getElementsByTagName('head')[0].appendChild(cpo);}());</script></body></html>