Direct numerical simulation of turbulent scalar transport across a flat surface

To elucidate the physical mechanisms that play a role in the interfacial transfer of atmospheric gases into water, a series of direct numerical simulations of mass transfer across the air-water interface driven by isotropic turbulence diffusing from below has been carried out for various turbulent Reynolds numbers ( RT=84,195,507). To allow a direct (unbiased) comparison of the instantaneous effects of scalar diffusivity, in each of the DNS up to six scalar advection-diffusion equations with different Schmidt numbers were solved simultaneously. As far as the authors are aware this is the first simulation that is capable to accurately resolve the realistic Schmidt number, Sc=500, that is typical for the transport of atmospheric gases such as oxygen in water. For the range of turbulent Reynolds numbers and Schmidt numbers considered, the normalized transfer velocity KL was found to scale with RT-1/2 and Sc-1/2, which indicates that the largest eddies present in the isotropic turbulent flow introduced at the bottom of the computational domain tend to determine the mass transfer. The KL results were also found to be in good agreement with the surface divergence model of McCready, Vassiliadou & Hanratty (AIChE J., vol. 32, 1986, pp. 1108-1115) when using a constant of proportionality of 0.525. Although close to the surface large eddies are responsible for the bulk of the gas transfer, it was also observed that for higher $R-T$ the influence of smaller eddies becomes more important. © 2014 Cambridge University Press

The Translation of English Passive Voice Into Indonesian

English and Indonesian have different grammatical patterns and cultural values. That is why, many problems that students studying translation subject have to face. One of them is how to translate English Passive Voice into Indonesian. That is the reason the writer aims to do the research. The research is to describe the translation of English passive voice into Indonesian by analyzing two novels, which are Kristan Higgins' Waiting on You and its translation Nina Andiana's Penantian Terpanjang. This research uses qualitative method. The writer collected, identified, the data concerning with the translation of English passive voice. The results of the research shows that there are two categories of translating English passive voice into Indonesian, namely English passive voice can be translated both into Indonesian passive voice and English passive voice can be translated into Indonesian active voice. English passive voice is translated into Indonesian passive voice by using prefixes di- and ter-, meanwhile English passive voice is translated into Indonesian active voice by using prefixes me-, men-, and ber-. From forty one data which are identified there are 32 data (78.04%) of English passive voices translated into Indonesian passive voices and 9 data (21.96%) of English passive voices translated into Indonesian active voices

Meningkatkan Kemandirian melalui Metode Demonstrasi pada Anak Usia 5-6 Tahun di Tk Aba 010 Cabang Kuok Kabupaten Kampar

Penelitian ini dilatarbelakangi oleh masih rendahnya Kemandirian anak. Berdasarkanpengamatan penulis di kelas TK ABA 010 Cabang Kuok Kabupaten Kampar pada umumnyamempunyai permasalahan 1) Adanya sebagian anak yang selalu ditemani oleh orang tuanyaketika pembelajaran di sekolah 2) Adanya sebagian anak yang kurang percaya diri, hal initerlihat ketika anak mendapatkan tugas atau perintah dari guru, 3) Adanya sebagian anakyang selalu ditemani oleh guru atau orang tua ketika makan atau disuapkan oleh orangtuanya. Metode yang digunakan dalam penelitian ini adalah penelitian tindakan kelas(Classroom Action Research) dengan jumlah sampel anak sebanyak 20 orang anak. Teknikpengumpulan data pengumpulan data dalam penelitian ini adalah observasi dan dokumentasi.Teknik analisis data yang digunakan dalam penelitian ini adalah teknik persentase. Hasilpenelitian dapat diketahu Peningkatan kemandirian anak Usia 5 – 6 Tahun di TK ABA 010Cabang Kuok Kabupaten Kampar pada data awal diperoleh skor 301 dengan persentase37.6%, pada siklus I memperoleh skor 413 atau 51,6% dengan kiteria berkembang sesuaiharapan. Terjadi peningkatan kemandirian anak usia 5-6 tahun pada siklus II dengan skor593 atau 74,1% dengan kiteria berkembang sesuai harapan. Berarti peningkatan dari dataawal ke siklus II adalah sebesar 36,4%

Penerapan Model Pembelajaran Student Facilitator And Explaining (Sfae) untuk Meningkatkan Hasil Belajar Bahasa Inggris Siswa pada Materi Saran dan Tawaran Kelas XI SMA Negeri 2 Kawai XVI

Hasil belajar siswa di sekolah masih banyak yang mengalami masalah, terutama hasil belajar yang masih rendah. Hal ini disebabkan oleh berbagai sebab, diantaranya masih ada guru yang menerapkan pembelajaran menggunakan metode secara benar. Kesalahan dalm mengunakan metode dalam belajar akan menghambat perkembangan dan hasil setelah proses pembelajran tidak sesuai dengan yang diinginkan. Penelitian ini dilaksanakan selama 3 bulan dari bulan September sampai dengan Nopember 2017 di SMA Negeri 2 Kawai XVI yang bertujuan untuk mengetahui peningkatan hasil belajar siswa kelas XI pada materi Saran dan Tawaran pelajaran bahasa Inggris dengan menggunakan model SFAE pada SMA Negeri 2 Kawai XVI. Penelitian ini dilaksanakan di kelas XI Negeri 2 Kawai XVI yang jumlah siswanya 30 orang siswa sebagai subjek penelitian, untuk memperoleh data penulis menggunakan  teknik pengumpulan data tes dan non tes. Setelah data terkumpul dengan baik diolah dan dianalis dengan cara membandingkan antara siklus I dan siklus II. Hasil penelitian menunjukkan bahwa adanya peningkatan hasil belajar siswa kelas XI Negeri 2 Kawai XVI pada materi Saran dan Tawaran dengan menggunakan model SFAE. Hal ini terbukti pada siklus I dari 30 orang siswa hanya 20 (66,66%) yang yang tuntas secara klasikal, sedangkan setelah siklus II meningkat menjadi 27 orang siswa  atau (90,00%)  yang tuntas secara klasikal

Pengaruh Pendekatan Aptitude Treatment Interaction (Ati) terhadap Pemahaman Konsep Matematika Siswa Kelas VIII SMP Negeri 25 Pekanbaru

This research intent to see how big influence of approaching aptitude treatment interaction (ATI) to mathematics concept grasp student brazes VIII SMP Country 25 Pekanbaru. This research constitute my research experiment attention. Subjec in observational it is student braze VIII4 as agglomerate as experiment by totals student 40 person and VIII3\u27S classes as agglomerate as controls by totals students 40. Base analisis data to pretes\u27s score to know student startup ability on agglomerate experiment and control group. On student experiment group that will study by ATI\u27S approaching has average early learned result mathematics (pretes) as big as 17,15. Meanwhile on group controls student who will study by ordinary learning (conventional) have average early learned result mathematics (pretes) as big as 13,85. Analisis is data to postes\u27s score on agglomerate learned student experiment with ATI\u27S approaching has average final learned result mathematics (postes) as big as 74,63. Meanwhile on group controls learned student with ordinary learning (conventional) have average final learned result mathematics (postes) as big as 62,93. Of quiz result distinctive both of average usufruct to study mathematics finals (postes) that points out that there is difference which signifikan among both of experiment class with control class

Direct numerical simulation of gas transfer across the air-water interface driven by buoyant convection

A series of direct numerical simulations of mass transfer across the air-water interface driven by buoyancy-induced convection has been carried out to elucidate the physical mechanisms that play a role in the transfer of heat and atmospheric gases. The buoyant instability is caused by the presence of a thin layer of cold water situated on top of a body of warm water. In time, heat and atmospheric gases diff use into the uppermost part of the thermal boundary layer and are subsequently transported down into the bulk by falling sheets and plumes of cold water. Using a specifically-designed numerical code for the discretization of scalar convection and diffusion, it was possible to accurately resolve this buoyant instability induced transport of atmospheric gases into the bulk at a realistic Prandtl number (Pr = 6) and Schmidt numbers ranging from Sc = 20 to Sc = 500. The simulations presented here provided a detailed insight into instantaneous gas transfer processes. The falling plumes with highly gas-saturated fluid in their core were found to penetrate deep inside the bulk. With an initial temperature difference between the water surface and the bulk of slightly above 2 K peaks in the instantaneous heat flux in excess of 1600 W/m² were observed, proving the potential effectiveness of buoyant convective heat and gas transfer. Furthermore, the validity of the scaling law for the ratio of gas and heat transfer velocities K_L / H_L ∼ (Pr/Sc)^0:5 for the entire range of Schmidt numbers considered was confirmed. A good time-accurate approximation of K_L was found using surface information such as velocity fluctuations and convection cell size or surface divergence. A reasonable time-accuracy for the K_L estimation was obtained using the horizontal integral length scale and the root-mean-square of the horizontal velocity fluctuations in the upper part of the bulk.The German Research Foundation (DFG grant UH242/6-1). Additional funding by the Helmholtz Water Network