翻訳と辞書 Words near each other ・ Laplace equation for irrotational flow ・ Laplace expansion ・ Laplace expansion (potential) ・ Laplace formula ・ Laplace functional ・ Laplace invariant ・ Laplace Island ・ Laplace Island (Antarctica) ・ Laplace Island (Western Australia) ・ Laplace limit ・ Laplace no Ma ・ Laplace number ・ Laplace operator ・ Laplace operators in differential geometry ・ Laplace plane ・ Laplace pressure ・ Laplace principle (large deviations theory) ・ Laplace transform ・ Laplace transform applied to differential equations ・ Laplace's demon ・ Laplace's equation ・ Laplace's law ・ Laplace's method ・ LaPlace, Louisiana ・ Laplace-P ・ LaplacesDemon ・ Laplace–Beltrami operator ・ Laplace–Carson transform ・ Laplace–Runge–Lenz vector ・ Laplace–Stieltjes transform Dictionary Lists mini英和辞書 mini和英辞書 Webster 1913 Latin-English FOLDOC Wikipedia English ウィキペディア

翻訳と辞書　辞書検索 [ 開発暫定版 ] スポンサード リンク Laplace pressure ： ウィキペディア英語版 Laplace pressure The Laplace pressure is the pressure difference between the inside and the outside of a curved surface. The pressure difference is caused by the surface tension of the interface between liquid and gas. The Laplace pressure is determined from the Young–Laplace equation given as : $\backslash Delta\; P\; \backslash equiv\; P\_\backslash text\; -\; P\_\backslash text\; =\; \backslash gamma\backslash left(\backslash frac+\backslash frac\backslash right),$ where $R\_1$ and $R\_2$ are the radii of curvature and $\backslash gamma$ (also denoted as $\backslash sigma$) is the surface tension. Although signs for these values vary, sign convention usually dictates positive curvature when convex and negative when concave. The Laplace pressure is commonly used to determine the pressure difference in spherical shapes such as bubbles or droplets. If the outer radius differs from the inner radius by a small distance, $R\_2=R\_1+d$, we find : $\backslash Delta\; P\; =\; \backslash gamma\backslash left(\backslash frac+\backslash frac\backslash right)\; =\; \backslash frac\backslash left(1-\backslash frac\backslash frac\backslash right)\; \backslash approx\; \backslash frac\; +\; \backslash mathcal(d).$ == Examples == A common example of use is finding the pressure inside an air bubble in pure water, where $\backslash gamma$ = 72 mN/m when at 25 °C (298 K). The extra pressure inside the bubble is given here for three bubble sizes: A 1 mm bubble has negligible extra pressure. Yet when the diameter is ~3 µm, the bubble has an extra atmosphere inside than outside. When the bubble is only several hundred nanometers, the pressure inside can be several atmospheres. One should bear in mind that the surface tension in the numerator can be much smaller in the presence of surfactants or contaminants. The same calculation can be done for small oil droplets in water, where even in the presence of surfactants and a fairly low interfacial tension $\backslash gamma$ = 5–10 mN/m, the pressure inside 100 nm diameter droplets can reach several atmospheres. Such nanoemulsions can be antibacterial because the large pressure inside the oil droplets can cause them to attach to bacteria, and simply merge with them, swell them, and "pop" them.〔http://nano.med.umich.edu/Platforms/Antimicrobial-Nanoemulsion.html〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Laplace pressure」の詳細全文を読む スポンサード リンク 翻訳と辞書 : 翻訳のためのインターネットリソース Copyright(C) kotoba.ne.jp 1997-2016. All Rights Reserved.