Judul: Feeder kelinci ternak otomatis menggunkan prinsip aktuator solenoid
Abstrak: Feeder kelinci ternak otomatis merupakan prototipe yang diciptakan dengan pengaturan distribusi pakan berbentuk pellet pada konveyor sekrup termodifikasi dengan tambahan pintu akses teraktivasi oleh aktuator solenoid. Mikrokontroler Arduino Uno R3 pada prototipe ini digunakan untuk proses perhitungan jarak pintu akses, waktu tempuh pakan, dan kecepatan distribusi pakan. Prototipe ini bermanfaat untuk para pembudidaya/peternak kelinci sebagai inovasi teknologi dalam kegiatan pemeliharaan kelinci secara moderen. Pakan kelinci diatur melalui rotasi motor stepper pada penakar pakan sehingga dapat mengukur porsi pakan secara akurat. Penggunaan motor DC dilengkapi gearbox bertujuan mengendalikan konveyor sekrup agar berputar dengan konstan sehingga menghasilkan gaya dorong pada pakan yang akan didistribusikan. Hasil perhitungan kecepatan distribusi pakan menentukan waktu aktivasi aktuator solenoid yang akan membuka pintu akses pakan untuk keluar dari konveyor sekrup.
Keyword: Aktuator solenoid, feeder, penakar pakan, konveyor sekrup

Judul: Design and Performance of Automatic Layer  Chicken Feeding Machine in Cage-type Poultry House
Abstrak: Dalam bisnis peternakan ayam petelur dibutuhkan sistem operasional yang efektif dalam hal waktu pemberian pakan dan efisien pada bobot dan keseragaman pemberian pakan. Tujuan dari penelitian ini yaitu untuk mendesain mesin pemberi pakan ayam petelur pada kandang tipe cage dengan sistem penakar keluaran bobot pakan dan mendapat data kinerja dari prototipe mesin tersebut. Penelitian ini menggunakan pendekatan rancangan fungsional dan struktural dengan beberapa tahapan, antara lain: Identifikasi masalah, kebutuhan, dan kriteria desain, pengembangan dan pemilihan konsep desain, analisis desain dan pembuatan gambar teknik, pembuatan prototipe alat, pengujian fungsional dan kinerja. Mesin akan melaju di atas rel sepanjang kandang dengan penggerak alternating current motor (motor AC) dan keluaran pakan akan dikontrol oleh metering device yang diputar oleh direct current motor (motor DC). Hasil yang diperoleh setelah pengujian adalah kecepatan maju mesin yang mampu melaju dengan kecepatan rata-rata sebesar 0,267 m/s dan tingkat slip rata-rata sebesar 10,46 %. Rata-rata bobot keluaran pakan menggunakan mesin dan manual masing-masing sebesar 129,13 g/30 cm dan 134,03 g/30 cm pada target sebaran pakan sebesar 120 g/30 cm.
Keyword: laying hens, laying hen feeder machine

Judul: Thermal Characteristics and Dynamics of Tropical Cyclone over Western North Pacific Ocean: A Case Study of Typhoon Songda (Chedeng) 2011
Abstrak: The frequent occasion of Tropical Cyclone (TC) over Western North Pacific (WNP) Ocean lies from 10˚N to 26˚N and 121˚E to 170˚E. Sources of TC development come from warm ocean temperature where latent heat is released during condensation processes and subsequently concentrated in the boundary layer. Relative humidity at 850-700 hPa is responsible to produce the most intense storm. Meanwhile, weak vertical wind shear between 850-200 hPa is one of the dynamical factors that lead to the development of TC. Pressure level of 850-200 hPa is chosen to minimize the thermodynamic effect in the lower troposphere. Typhoon Songda (Chedeng in the Philippines) or TSC lasted from May 18th to 30th, 2011 and strengthened into powerful Super Typhoon stage between May 24th and 27th. Long curving track and the exhibition of all sequences of TC life cycle, TSC is then considered as an ideal case of TC. The objective of the study with case of TSC is to investigate the role of thermal characteristics and dynamics on TC intensity. The research is carried out by using Advanced Research of Weather Research and Forecasting model (WRF ARW model) version 3.3. Two domains are employed in the model. The first domain situate from 02˚N to 40˚N and 118˚E to 149˚E and cover spatial resolution () of 33.1 km. The second domain situate from 09˚N to 27˚N and 119˚E to 132˚E with of 11 km. Timestep of the model () is 120 seconds. The model is supported by the following physical parameterization, i.e., Yonsei University Scheme (YSU) in the boundary layer, Kain-Fritsch scheme (KF) in the cumulus, and WRF Single-Moment 3-class scheme in the microphysics. Initial meteorological condition prior to the formation of the cyclone is generated using WRF ARW standard-release model. Sensitivity of the model output is obtained from a selected single-parameter change scenarios, namely, 10 % to 20 % decrease and increase of wind shear initial data at 850-200 hPa, and by 10 % to 20 % decrease of relative humidity initial data at 850-700 hPa. The result showed that the negative correlations between wind shear and intensity are found in wind shear scenarios. Wind shears of 10 ms-1 which lead to strengthening of the wind intensity in the early period of Typhoon development are found in wind shear scenarios. The effect of wind shear changes on wind intensity is statistically significant in the 20 % wind shear scenarios. During mature stage, weak wind intensity occurred when wind shear increase as given in the WRF standard-release and the 20 % decreasing scenario. Different situation is found in the 20 % increasing scenario where wind shear tend to weak and lead to strong wind intensity at this stage. Meanwhile, the reduction of moisture supply at 850-700 hPa resulting from 20 % decreasing relative humidity play a major role in the weakening of wind intensity and reduces mechanical energy of the cycle process as much as 300 J kg-1.
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