Energy flux fluctuations in a finite volume of turbulent flow

The flux of turbulent kinetic energy from large to small spatial scales is measured in a small domain B of varying size R. The probability distribution function of the flux is obtained using a time-local version of Kolmogorov's four-fifths law. The measurements, made at a moderate Reynolds number, show frequent events where the flux is backscattered from small to large scales, their frequency increasing as R is decreased. The observations are corroborated by a numerical simulation based on the motion of many particles and on an explicit form of the eddy damping.Comment: 10 Pages, 5 figures, 1 tabl

Atom microtraps based on near-field Fresnel diffraction

We propose and present a quantitative analysis of neutral atom microtraps based on optical near fields produced by the diffraction of a laser wave on small apertures in a thin screen. We show that near-field atom microtraps are capable of storing atoms in micron-sized regions, with estimated trap lifetimes of about 1 s, when using a moderate laser intensity of about 10 W∕cm2. The depth of the proposed Fresnel atom microtraps is about 0.1 mK. An array of such atom microtraps could have applications to site-selective manipulation of cold atoms

Pembuatan Program Perhitungan Perataan Jaring Sipat Datar

Sipat datar bertujuan menentukan beda tinggi antara titik-titik di atas permukaan teliti.Di dalam geodesi, tinggi suatu titik didefinisikan sebagai jarak terhadap suatu bidang referensi. Bidang referensi yang dipakai adalah bidang equipotensial gaya berat (bidang nivo) yang berimpit dengan muka air laut rata-rata yang tidak terganggu. Bidang tersebut dinamakan geoid.Dalam pengukuran jaringan Sipat Datar, untuk mendapatkan titik tinggi yang akurat terlebih dahulu dilakukan pengolahan beda tinggi kemudian dilakukan perataan jaringan (Network Adjustment).Perataan jaringan menggunakan metode kuadrat terkecil. Kuadrat terkecildimaksudkan untuk mencari suatu nilai akhir sehingga jumlah kuadrat dari residu adalah minimum. Sehingga tidak mungkin ada nilai hasil hitungan yang lain yang jumlah kuadrat residunya lebih kecil.Seiring dengan kemajuan di bidang komputer dan pemrograman, maka perhitungan perataan jaring Sipat Datar menjadi lebih praktis dalam pengolahannya. Aplikasi GLN 1.0 menggunakan bahasa pemrograman berbasis windows yaitu Visual Basic 2008. Aplikasi GLN 1.0 dapat meratakan jaring Sipat Datar dengan dua metode yaitu parameter dan Bersyarat. Hasil perataan pengamatan jaring Sipat Datar dari aplikasi GLN 1.0 dibandingkan dengan hasil perataan dari Adjust dan Microsoft Office Excel menunjukan hasil yang relatif sama. Berdasarkan hal tersebut, maka disimpulkan bahwa aplikasi yang dibuat dapat digunakan untuk keperluan perataan jaring Sipat Datar

DISCRETION PROTECTIVE OPEN CHECKING FOR REDEVELOPING CIPHER CREATED HAZE

Several techniques that cope with the sturdiness of outsourced data missing of local copy were suggested in lots of models thus far. Fliers and business card printing of remote trying to find regenerating-coded information provide private auditing, necessitates data keepers to constantly stay web mange auditing. We introduce an empty auditing approach to regeneration-code-basis cloud storage. For solving regeneration impracticality of ineffective authenticators in insufficient data proprietors, we initiate a proxy, which regenerate authenticators, into established public auditing system representation. As opposed to direct improvement in fliers and business card printing of public auditing towards multi-server setting, we advise novel authenticator, that's appropriate for regenerating codes that's created by way of several keys and they are regenerated by way of partial keys hence our method can totally make data owner’s burden free