Highly turbulent Taylor-Couette flow

The research issues addressed in this mostly experimental thesis concern highly\ud turbulent Taylor-Couette (TC) flow (Re>105, implying Ta>1011). We study it on\ud a fundamental level to aid our understanding of (TC) turbulence and to make predictions towards astrophysical disks, and at a practical level as applications can be found in bubble-induced skin-friction drag reduction on ships. In PART I we introduce the new TC facility of our Physics of Fluids group, called the Twente turbulent Taylor-Couette (T3C) facility. It features two independently rotating cylinders of variable radius ratio with accurate rotation rate and temperature control, torque sensing, bubble injection and it is equipped with several local sensors. It is able to reach Reynolds numbers up to 3:4�106. In PART II we focus on highly turbulent single-phase TC flow. We measure the global torque as a function of the driving parameters and we provide local angular velocity measurements. The results are interpreted as the transport of angular velocity, based on the model proposed by Eckhardt, Grossmann & Lohse (2007). Furthermore, we study the turbulence transport in quasi-Keplerian profiles, mimicking astrophysical disks. In PART III we study the effect of bubbles on highly turbulent TC flow, focusing not only on\ud global drag reduction, but also on the local bubble distribution and angular velocity profiles. We find that drag reduction is a boundary layer effect and that the deformability of bubbles is crucial for strong drag reduction in bubbly turbulent TC flow

PENGARUH UMPAN ALAMI DAN UMPAN BUATAN TERHADAP HASIL TANGKAPAN MENGGUNAKAN PANCING LAYANG-LAYANG DI PERAIRAN KABUPATEN MALAKA

Abstrak - Salah satu sumberdaya perikanan ekonomis penting yang dihasilkan oleh perairan Rainawe adalah ikan cendro (Tylosurus sp) yang dikenal dengan nama lokal sebagai ikan Manuk. Alat tangkap yang umum digunakan untuk menangkap ikan cendro ialah jaring insang permukaan, jaring insang hanyut dan pancing tonda; tetapi pancing layang-layang lebih mudah dioperasikan dan menjadi populer di Kabupaten Malaka. Keberhasilan menangkap ikan dengan pancing layang-layang sangat bergantung pada ketersediaan umpan alami dan umpan buatan. Umpan alami dan umpan buatan hanya digunakan pada bagan saat   musim tertentu, hal ini berarti bahwa pancing layang-layang tidak dapat dioperasikan sepanjang waktu setiap bulan.Penelitian ini menggunakan umpan alami dan umpan buatan untuk mengetahui pengaruh terhadap hasil tangkapan pancing layang-layang.Penelitian ini telah dilakukan di perairan Kabupaten Malaka, dengan menggunakan metode eksperimental. Dua jenis umpan yang digunakan, yaitu umpan alami ikan tembang (Sardinella sp) dan umpan buatan yang berupa ikan berbahan karet. Analisis data menggunakan uji t. Hasil tangkapan  selama  penelitian  berjumlah  28  individu  ikan  Cendro  yang  terdiri  dari  21  individu  hasil tertangkap dengan umpan alami dan 7 individu hasil tertangkap dengan umpan buatan. Hasil analisis menunjukkan bahwa penggunaan umpan alami tidak berbeda nyata dengan umpan buatan pada pancing layang-layang untuk menangkap ikan cendro di perairan Kabupaten Malaka. Kata Kunci : Pancing Layang-Layang, Umpan Alami, Umpan Buatan, Kabupaten Malaka   Abstract - One of the important economical fisheries resources produced by Rainawe waters is cendro fish (Tylosurus sp), known locally as Manuk fish. Common fishing tools used to catch Cendro fish are surface gill nets, drift gill nets and trolling fishing rods; but kite fishing is easier to operate and has become popular in the district of Malacca.The success of catching fish with kite fishing is very dependent on the availability of natural and artificial baits. Natural bait and artificial bait are only used on charts during certain seasons, which means that kite fishing cannot be operated all the time every month. This study uses natural bait and artificial bait to find out the effect on the catches of kite fishing.This research has been carried out in the waters of Malacca regency, using experimental methods. Two types of bait are used, namely natural bait Tembang fish (Sardinella sp) and artificial bait in the form of fish made from rubber. Data analysis using t test. Catches during the study were 28 Cendro fish consisting of 21 caught by natural bait and 7 caught by artificial bait. The results of the analysis showed that the use of natural bait was not significantly different from the artificial bait on kite fishing to catch cendro fish in the waters of Malacca regency. Keywords : Kite Fishing, Natural Bait, Artificial Bait, Malaka Regenc

PENDAPATAN DAN TITIK IMPAS PADA USAHATANI PADI DI DESA PUKDALE KECAMATAN KUPANG TIMUR KABUPATEN KUPANG

This research aims to find out the amount of income, the break-even point of production, the break-even point of price and the break-even point of rice farming in Pukdale Village, East Kupang District, Kupang Regency. The data collection method used in this study is a method of surveying and interviewing directly to farmers. Determination of the location of research is done deliberately (purposive sampling). Respondents were assigned as many as 50 people who had been selected in simple random sampling. The type of data collected is primary data obtained from live interviews with respondent farmers who are guided on the question list, while secondary data is obtained from related agencies and literature studies. To find out the first purpose of the data is analyzed quantitatively, to answer the second goal the data is analyzed using the Break Event Point analysis. The results of the study are 1) the amount of rice farming income in Pukdale Village, East Kupang District, Kupang Regency is Rp19,024,600, 2) break-even : BEP production of 67,257 kg, smaller than ril production of 162,380 kg, BEP price of Rp4,141.9 is smaller than the ril price of Rp10,000/kg and BEP Receipts amounted to Rp278,571,763, smaller than the total revenue of Rp1,623,800,000