CINXE.COM
Just a moment...
<!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: '913666afcbaf3dad',cH: 'm.BiTfMtvrhxMIWPgcelnmFPZE2FQc9wBUlWaVx0qlU-1739801848-1.2.1.1-exZbix_t60o9CXZ1o3QB2bUFbMzAoamt5SZfrSAidZNI49md03j8L85xFeAiS5e9',cUPMDTk: "\/abstracts\/search?q=working%20units&__cf_chl_tk=NRgK3kuZ0ic9jPVnz97.HGnDIPJBcV.1s9PDEgzfL6M-1739801848-1.0.1.1-Pwyv4S0nSUVulT2LQ3FtJiDlvwdbSRlvdI3h5vGDP00",cFPWv: 'b',cITimeS: '1739801848',cTTimeMs: '1000',cMTimeMs: '120000',cTplC: 0,cTplV: 5,cTplB: 'cf',cK: "",fa: "\/abstracts\/search?q=working%20units&__cf_chl_f_tk=NRgK3kuZ0ic9jPVnz97.HGnDIPJBcV.1s9PDEgzfL6M-1739801848-1.0.1.1-Pwyv4S0nSUVulT2LQ3FtJiDlvwdbSRlvdI3h5vGDP00",md: "lE2C7R69FK02qxikRlSqFFKT_ESxIl3LxJqxwXhVcRs-1739801848-1.2.1.1-S8wz.XiOpdE0IxM65pz2mm_kK9_9TwTnPXxAZTdStV93wm6g5pkQf44U04xpsPCF_K9pjT1JGZ8MNS8UwnOCBHwpey40kxJKaW_tPiULyxKKztk76LNfLndUHdaNDbjMhRdhESGWd5mF8.cWtsF7f0w03sWNMRYTJaGau0ulQtjlRTmPtl7l4Qms_0Z5EixiAySL.RMeXHySDODezzj6LaKc7A1QjwsB2K57j4_YE_bb0MEj3SfEiDOJVvR6rXNOfbQ1MN2lXC5VNygXQVwhEidvXm8BYOnGrZnu5J0FUTeidBpXdF2pikNvSGGNG.j5zQZDt25w8EmjKKZC_adjT7MlcJ4ScbaZlUwzWXrjM3IDcXNdDd585p1O92P6Vi.FPfurHbaA.jU2n00sGw32q7Jreg9xW_PI18YteutGDTcHZJbl2JzflUo8okdtcCyMBFBHEzoUlL04m0.IXsMRo.KahkTDB6lP6sTVMfK91qJwti4TTlXz4gryw1EZdImOgwYdhIZv8IkeJMkA98.ANbicBqgaOENVe7XJyf44PpG1hxo21agC9AQm2p4eqr5cABFYV_ATe2gVFrcSeLwd4iciOmPqcceF4lusDAcm9VDMyavyarL5DnnviFb2vxGSruGedfSiDARyXP1c4yYk02jUb7ODl1OWVUXZK86ch.U4FG9mIIhYstN1eE1SlVINVpXiphNeDV15r.HIWEi9wfaybxDQbZ4x7W3N77zf6qqDu4F2.Ib3WsAVc2_tw8ZoMx.4jflbWoU7F6V7OXBXGnhpM225RJuljnGffp5ujJQGYj4lxVHCPJ77dhVQu1W_qctf8_Ovwdkb9BsOlgUkBx94Lve5w62PNc1qTUYw..GVDj_tyXTGoJZbzuYsvWGTFQG4u_biO.9WiodXRbBfx9Lx4sLgD12cBofaplPCi.qxNLp6SeWQAsWSqHNGl6pwJQMR943yZ3N1rlRkTpmApxy7oIZohG05vGqXpqnzErZhxWJHJct2AFUZfZ08zkJdlQkkK2w0TIRCE34tD635xkuFRhK50ihZ_jbLhPeCAkpuU334rQt7YPC2B1_JjK3x7ZioIX2BrMq_rXeFi_byaaz2SwMHlBHMCpV3A89iTA233SE6LOa6juJGt7vxuFXqMD8HIOcHj8csl1m3byNHcOizfIkdLVSREZfaMQa4McXARjLYcHBVnDy4375zvephag2N8IaYPsgLLN9TuMszkzvNAAQxEiuYP.hdDK5GNPfJoZkiY9V6WUOUP1CkR2IbL_rW0Om5me6_cOSn3jq63Ip1Y9_VS41LnE9VfilKTwWxtlxq.G53FLiBIuvaiKcEmZUCrqmSuy_IFTOIl5Nh3S8_UGm9JgCUHEi3dbrBEKnvQUSBY9qTjHWT_pAalnxcDVXTED1nL2_7xOZ9Z7sRbcXPQycySicYl3PhfDDUIpbf7B9zlFMTCIW_SuhsrfAPDL0gxhS2E_q2Q2UM1kv8PPc1msum4R4uUhKCFtIJMeComsa_d0ZMA4uTONiZNi.JKddCw4JurNpjCiuffdYkM6J1AZArbV.rw3IEp_Xjn2lvlHuOK3ODFsaYItSdw_Jsu.W1Y_UTOCwsp9Bw4nloT26b5XjoK7I4BMakxGQe3r.6hmjuqDk0yPDjK_XBUL9Ia1D7ixEWkQzffbR5fJ3zUmLT6ArCQi7U3G8M8qF7V1a0B8WCkefpGfaXrSWaO4OcxuySKUOIsdmZLtL.ft7EDhAq3ICgEOBylS_TjPvgXY2rucKA6OtjuJTWKvVBfXGL8obJcTSh4ib8ETymvDw5JOtqfA5WU3Oi6O_o6NTGSDOejmcnzKn6Vv7QcLadzGLOiLYiH4ILEuHVxsMM7wgq1.yvgCbqxvLIPdHSbJ7be1MAeDMIgdYrekQHSi2x77uZep0L_5g8TBmK5xVONsi_87O4fVIxu4N1LVI_854Ysag",mdrd: "fb46eQG1.4XX6qeEUD7fnbnDiiMnwVBuYVWJnrV2o0A-1739801848-1.2.1.1-pDLrxlseAIMV.NL9ugZ2Q4DxXmfb.OS7Z2RLnfCd7.ZM_2S103_4zIJMV4x2iLY41EuhXlEjaepXojpWSgXvNea48wT4eoQjk__4q4sA5iXhaXTIZrWukyFf4m_WGQt29oG5v30Pgz0wXbdY0Y0wwDtIOjo5tXkMb6saaT2VM5BNWJ9OvM5d68E4gtY1.ly6ZUFSchHJSRK7VpfP8X5qygUVwpIIPEP.SUbfdQvg4ri9T2uPlgcpXWmEDBGZdyukMvKrUZl3Bu38e3uo6tTtxADPyQGsJVcXvljvhJn88QQ_SWdLeHopPZiQK4MeKPLLK.gBkG50KUSlIgzZKw7d92cfo0n9x_2k02jPX1iMJUdX5HPp1kOJv2ZrmtsRmDDwHjA8qvpfY7PPZETew1fcIamoPJ9PSq6lYd54wEDgQe76h05oh8IiZ03q07myI_UYcDL4qgnR4vYnpFMm5M3dISk5eWrPIVeJru.LzFlKHveQ7wue8gNrWx4NDe9X.u.YV9KJxJQ01SephtSBCX8a6.i3aldXLiRqztadt_xpLDLqB0xlitxdFS2cXL4ks4snQoJsGbnvdzFI1SLPD7exZKo7l41F.UCfm_xjU9Bykj3tGyJ35Rs6wneC_N_lHop6dnn5_KVwVviMqK_oemHML6E12KnSJEuJKmM1w5NRb.5BAhl4P1i8VAUwe5G3Kxh92chSw7jNZjgs1gijvp1ZPl7E.QIe7DoSeJaJmv.kkMyPCk5fRLSkSLM86H0v_cmvdz53IRzWEG9Dg7Xz4BIcZJeEWTKLnAfqje2jPD8A5n2_ibW4vquyYp83YG5GfER30vhFjxnTc6L7Zc2HzfqNVJzFGiW2lojkyrMvKY8wF4DBergWLhMuoAeT1PcV9xOaUoO0dbYzjCxN6W0bMLKl5Uqq_hi7L2sTyJOjhgK6DUB79XlXfE69X5AlXKgQKoRoxr8dQajwkr5Zpy4Plbb9UypW69N4U9MtCMxQHCokHpWYS2clmya5gv_ynNIHGZCIHuR1xJII6p0TDTdP7jTlMuUQHkh7JYQ8PozK1HeVP2eEpwbiZ4gkmccV.nJKzNzjc3HecigMQipWI0BHSo3eFKtiO.EUnVQX_2X9fLQZ89lgPI9QxLYvWag223_8vpyk0Z6o_lZupV7eBZhr.I442reqW_GkgeqxTNh4g7DBk5xOT2T21oEGPvHqaCWh6Jqr2.i.55S6VCmroABPC6PtgzKerjw_uRZNRedNWGCt1Nji75E_Fa9sy4.B4v4MLVbh8tRTVfpczx3SX.wP90wuTJPlbDkJE1nKjlbpc14G7VsFu2gmbrgN05NW3L9RXn2ZnRfslEJnktNTi9xUIqL4X4TlAgCpObqIyhQqIBsz2QX_Xcn4L32qN2ay4nm_vzYlHuJujLOVWrPDFXFltfNGYFHN0pZSnaLnyRaK3ONZGOGVBcOMwbAjW5.uPbg_UTc2qGYDP5Tn7yt1lKXtyEXM.r6P3VIL0eoywNiWafj6o3KCM1xkuQJdunsYQvKOclI8d7cuVkaQPIO.tavX4HpGnnunorTFN08OdbjLnzt2mx5z2ccHuEx7XEFpxIDPISd67QQZf3SBjCop7fUygCWbDRXjh9gtaUcL8TzWfgZAo7vObKSf867M8S2.DiSenu15h2cmmMR1Ni5_rBhQKskcMQYlNJw_gjb.a.LipJhmBqnYkYDt1Ipnu.nXJ5nmCshsfwlyoNIn7sESwKkEWCzjL1nH9idxdXfZemDVDyP12oXbG6VAgkhc0Ze2SmyDVof5TM8hjUxyEy9Pk.B0P_EjnVQTm4xNj3ZgrHXJ._oG76xJgWoS.ydMsaJJli5LbXAT4nPwbfECg5hEEyQyMtVj61KrXd.U3d21MRNjdab4F1d7qwrNc5ACDw30rDsDz0.fyGjy.BNK9ceE82.Bt16LMytdFYCLinfWd73DXHmvrJ.WCJPSZiYuZSX3.ihnuBig"};var cpo = document.createElement('script');cpo.src = '/cdn-cgi/challenge-platform/h/b/orchestrate/chl_page/v1?ray=913666afcbaf3dad';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=working%20units&__cf_chl_rt_tk=NRgK3kuZ0ic9jPVnz97.HGnDIPJBcV.1s9PDEgzfL6M-1739801848-1.0.1.1-Pwyv4S0nSUVulT2LQ3FtJiDlvwdbSRlvdI3h5vGDP00" + window._cf_chl_opt.cOgUHash);cpo.onload = function() {history.replaceState(null, null, ogU);}}document.getElementsByTagName('head')[0].appendChild(cpo);}());</script></body></html>