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: '91340fb6bfaa5f82',cH: 'ANDTyokdwM.1yYqtT3e1Ngz5GS7Jd4WgL7EFs_VpsWg-1739777314-1.2.1.1-mZwuHNBeWEeQ6iadXs54yyXPZ_LvHVolafAk331P.61l6eQUUjNndKLsfQduSbYF',cUPMDTk: "\/search?q=electric%20charge%20density.&__cf_chl_tk=JdkblnxtE5wKzpO5B411tFqieH1_BLpHUMKbBjMEKas-1739777314-1.0.1.1-yUiRTJIciqkIcZMrsxjjnoT.NaLR7oSXcOn5qmZHAVk",cFPWv: 'b',cITimeS: '1739777314',cTTimeMs: '1000',cMTimeMs: '120000',cTplC: 0,cTplV: 5,cTplB: 'cf',cK: "",fa: "\/search?q=electric%20charge%20density.&__cf_chl_f_tk=JdkblnxtE5wKzpO5B411tFqieH1_BLpHUMKbBjMEKas-1739777314-1.0.1.1-yUiRTJIciqkIcZMrsxjjnoT.NaLR7oSXcOn5qmZHAVk",md: "2bBkxUVQhXk4T6Hq5knPcSFQMfS06PL5.M4o3iGjAsk-1739777314-1.2.1.1-N4MjLl23O_e2QcTM7XNuuRUcGOP4lQ.ZwI2va625pCcOBT5OHJ515QGERgRWCP0LpRPVVGpIezCVhhLhCJAooKnNMMw69AALJ5x890m1c1O4eytvaghSB1naDp_BPd9kAlNDSFiALQF9XIwvF9.PnJWiyMm8WIohQLeNgT_NmnRy3etApBj.5c9kPAVle4JYhMoen.URH_euJEP1.0naC3JytlGHETrZeKLEnlqswme1mbjJlBY5kOysT6IzFloYx5nju.HytGW5smRX8IjebdgV8ptFJcZvpHW29J0PmJbMjoZoNJl1JEY_PB_J_GqCTXUP95RBUCahoLpss.wGYDGRB.sppexaYv5F614EoZnwR4ay2kaIWJ84JDVzAWWb_JtruKnZSw2tyVqDsLrAmCt31niwlS0MHVIWYGSr0WgQ7s3zpkt7mWF3EpeOzKkVFn1zYNB3eZSg0UgX7lfZ.z_if6Z1mt9E6d8q_ZUzCmfqka0gKY3oCyGW466K35IClIVwRnz9.Vu5GtvLmUDglBKxUeelpwx54.3MHb_inTBNEqf6Jk3M0lUTOgu6V2ETN4c_JnWtsxrRutrs8V286pEwdgN7Xrek6M0xkOkGCUbFpAo_6mrTN17rqik7vyVYQYtzztxGpLjVRH9pL3cXyyY2o4vjohPw0OCOyJWyYGGQ3YySfQhq5qbkyMqyMhLn.oPlBVc8x4PjgfsYnX9xKro8fwZFFTN9kMX7e8frI9CZkyrCpLCinRg6raKUIeGmreGGybXCihSZ6HcpPuAcGpG_NGYW05Gal7GsaelPhOknD3wqzxjvpJBC1eD1BWoyG8ea7MGBZKvTNMOWopDeCISs.giDPnoCDdNLXQvWrXxxmKaDR7Jk9PUlpmLMEQNVsC0Ea492V5j5Rj7SxDx13c5u4iZ7Jp4yL6hHd_20cpP3cKihhSeE_kB2sS0WDehbNnsShgTQwp5cD_rSAHULMDBZC5o2.XoBCh1ZfICGP9jJR0kozyTWZ.ukLk00ZimkdJRWSAOiVWSZ7tqpxRTiolh9CUNwlhu93UbblKhmg1eRvZ1tWZtwq3vqfHyHOT0.NXdffc4iSbMu2JGZRZp2I9MXeWdtplhwTkNLHE7Ja9IlHlsh1FONlEwrb3q8HLO9swQsMl4D64ab.b4rhNUo42l8SfulQhx5luZEudPKrVQ18sB5BD91fvkKkfWmqF6iKd2KoMHCPK8qZYIELib9RBQtgnbaNsIUT3vaBgQ3n.bp9A4jXQpsiuxaU3rWomSyLWHPyLNFz2VbDalEKadIf4toWYk2qNc9OmBsalwpQtkNygzs7Dss3QcUXl5fjQEq1xakMBGo6x.bYo3VmQIQVzXIGY96_r_SNFptRyH6x_HvqC6iV7To4kYQFLj8XbN_Dk31ivQMU7OBQz7dKupSpMooWcWkalUFTupFCz8L6R6Lw2Qrr4Qt82N8prrsxUx7_MXLKnVtay9NErNnBkK0mkX.OfuLjW8bNUBaB8a313JmcpTy_Wp8bOio3I6qNcCjQZeJJPmh3iy4jOhuduD6_L1xCeuxfDGpw4h6Rg_Z9hWp5RbMb3knABwo73rENc5OFB07_BVvtxoMb8Tpro7GFkI6jA1spFtiq06ZA6dCMcqEux_y.X65WxIHcaFd6AEgu.oiytZPiLZGr3kw547pd7CHojHtNPm7Uf1nNFXo2Cn.XbTOx3QLt.J51rudE_KUXm_GC.t07wprmIb1ifAVcm1MYxOtDTRlpfPT.LD_eyBqBSmqHFsqRguVG5ba0CQJ.Bks47XaqBEEWrW1ox3y0A9w7szVmLikOx.3FJdz0qm2Ovq789yNZvmhjF2GXVGfu6XUD2C7xXj.BgZpzVmX6bCoDTEhGT29ceNq7O1DQGnI61UGZmZBXoYhedSAV9AV0bm1I8ein3hU5ggKAAehJEY7jGTjpFuXJfdtQ79MBOs",mdrd: "hGwlQOYYnrNVao33sjJbBUCZa3X.UzztYDGn.hKws6s-1739777314-1.2.1.1-Q8hFO3v8v5llGE8XN6y9q0tTLZey83UzYeP0abNS5lLDU96mkzJ_coY.nMfZvOjACg6IuczxCNPbt3QxfySjkzGA8BWqg7L4WW1GzgBqc5Sjs8qy3viSi.Xje6e9bd33wDCVjn0_KFX0qiWoNyWPnunUqSqXfRLSkg780MkYiqqBdaa697ZxDWdhSK0KPgL4L7EyQE28xd9_MGPgj7OaHuhH4PK4j4E4j78ooXxKNDdjfKTu4P7onC9J2IE8sRaC3bBVho7oCw.6SCgjUTVIEEMblgSiF1gkpBdPUvb9a4VjoKEnxl_.0CR.jn6cha__1m75Uum65gVp_XjpAO09jSi8IIbHrKYPBJSCPHhCTf1hV_aBcgT7UKh4Hg6cUMEeWK3PwRjg05fsQUbyl.C7naam1eKLqRYOs5LLFj8tvjF3nrptky1WWpY3R8KFTx3GDHh3H8f1oP2ByUNlBtTmmL_sMQxrJntx.YMbmnYXDDGKOrhQI0ftXr7XE.mSygqQNWwYV0UMWIhwqHyzBcetzJZAX0ME5YcNjtkzT8wRqvOc2hPh7.SP1XDF6Fwy2cUB1pi0XPL5f8GEbH6h7r3.PdpZtmgolvbAUzJYUWh01lGzqAsmQ9YlSFbsiyhGNjSkZhymbaqYUP1EabDTHl7BUmbQabP3c9whMvTMCa1ILO0odhscP1etOrMXXoRjj1QVIp75QfmJoC3MhjCUmp8GS5IBX098wTgYPwUHALDSd07EF9iDGxwqftA5cuR06ZHscPS33cD.s0DbmqkW7IeOTQ3JGZaga1WTR7Zxe3F1ksTUu6G5PF7FfxY2Uhizzw2HvnVcHviHJNWiKqXsjsmsY3JLcGjW8ekb7ZqtG4YH_MX16Jjc6tp3BvPa6ZOmUnX83Pc2nkBsOACetPeChv8xqFE4gPcEpuVTzYvfRMJSKTGGeDQO1LmjHyW4hBo0sCUVeHEsaBDSAdb6xMGqfAtngajGD1DoP7TzUeJGkCwvQVdtPXe7NsRvgTBfXPVQXhmBQkuyqIRJzLnVyBsgVAtr25w4wJz8Oqfetcg0bkhKTCgO821v45jgbOzqY26Qk_w7Fup8P390eya24c8vpAWP2GrfzIC7C6U1J8NNcqmSBhVIFon8gnsLqAHDzQ3W7zpRqtljHijEeNSL899wuQOgiWZKcSRYeUH5LQI.AB8faTr93oAfNK34VpipTWaKuf2aApjQfBcsaxaPGoypb_7K7lOeklJPtRIS0t79RAXu0vLIs3AsUxEKbtJ8nA6I1BuTqrCcDFDT_4_ycOsqhr31.sbGZSjUbj0OaTUKV7bfw48VravTHNM5Y6BfmVb6vwih.YhTCtd2GLqJ8q3zNBvlUqYwpjkZ7S73ok321Rd_4AepW6Ke4B7xnulDJO9UUYtHLupu_JhTu4ebb0qTRb3llmVgnRpDnzvR9Yud8NDMR9uNx8Ggq0uo4.3zSzDd7vyNozdbVAyUU13phI7pp.BMW7yx_xrjD_ibFx5p2Xs4I3xWFOnXMi1D_WVSwbzeP1yHJ28U7vapaAbzu8h8rxa6xE49jO4iX0Jdf.qjLFuzkQGwBD_ilIICk8TRfL7qMbYgRoVnKJLtopilsuKPUl5mwlSyMSIgzRtD1o_csD3p0lNGcnjWFU6O8qL6ecnNV9jrKHIFjniTswXrRndNAcUr3x3vt9wYgMT9LbZA2yCQ1HRSCV1gekLFdtOZ4FtvG6AFFx5edasG2yEzCBWj9hr0k1_6DSl7jOGR74vNwARybZDsA82Wo.zLYnaXBQ.guq1VC3IcZ3QNFMs4P3rROYudxK12N5sXM0h4Bqn4DCfmja2LA5cSeQdpifzLFDELTB23Y1AjJiifE44v_v2OOynulpCDTj2VHMGEPYOBkU1Uqn3whlEuqjcPTsabPF92W_lfaHSJI9pnNl5LFg_TzpzBoOvC9XA7XWet7wFhkabBd38hfHv9afJS5CyIymzjijCCb.ZHTfZO40GKi8ge8j3DTg"};var cpo = document.createElement('script');cpo.src = '/cdn-cgi/challenge-platform/h/b/orchestrate/chl_page/v1?ray=91340fb6bfaa5f82';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=electric%20charge%20density.&__cf_chl_rt_tk=JdkblnxtE5wKzpO5B411tFqieH1_BLpHUMKbBjMEKas-1739777314-1.0.1.1-yUiRTJIciqkIcZMrsxjjnoT.NaLR7oSXcOn5qmZHAVk" + window._cf_chl_opt.cOgUHash);cpo.onload = function() {history.replaceState(null, null, ogU);}}document.getElementsByTagName('head')[0].appendChild(cpo);}());</script></body></html>