Judul: Uji kinerja alat pemerah susu sapi semi otomatis tipe engkol
Abstrak: Secara kimia, susu adalah emulsi lemak dalam air yang mengandung gula, garam-garam mineral dan protein dalam bentuk suspensi koloid. Komponen utama susu adalah air, lemak protein (kasein dan albumin), laktosa (gula susu) dan abu. Komponen susu selain air merupakan Total Solid (TS). Total solid tanpa lemak disebut Solid non fat (SNF). Beberapa istilah lain yang biasa digunakan sehubungan dengan komponen utama susu ini ialah plasma susu atau susu skim, yaitu bagian susu yang mengandung semua komponen kecuali lemak, dan serum susu yaitu bagian susu yang mengandung semua komponen susu kecuali lemak dan kasein (Rahman, 1992). Susu sapi adalah salah satu hasil dari produksi sapi perah yang sangat dibutuhkan oleh masyarakat Indonesia dalam usaha meningkatkan kebutuhan gizi. Cara pemerahan susu sapi di Indonesia masih banyak menggunakan cara manual yaitu langsung dengan tangan, walaupun sebenarnya sudah ada mesin pemerah susu otomatis. Faktor penyebabnya karena harga mesin otomatis sangat mahal, yang jika dibandingkan dengan keuntungan yang diperoleh peternak sapi perah tidak akan mencukupi untuk membeli mesin tersebut. Untuk mengatasi hal tersebut telah dilakukan kerjasama penelitian antara Departemen Teknik Pertanian ( TEP ) IPB dengan CENTRAS ( Center For Tropical Animal Studies) LPPM IPB dalam rancangan alat pemerah susu sapi semi otomatis tipe engkol. Dengan adanya kerjasama ini diharapkan akan dihasilkan alat pemerah susu sapi yang sesuai dengan kebutuhan para peternak sapi perah di Indonesia. Dalam penelitian ini akan dilakukan uji kinerja dan uji pengoperasian alat pemerah susu semi otomatis tipe engkol dengan tujuan untuk menentukan efektifitas fungsional dan produktivitas prototipe alat pemerah susu sapi semi otomatis tipe engkol dan menentukan beban kerja kualitatif operator pengguna alat pemerah susu sapi semi otomatis tipe engkol. Kegiatan penelitian ini dilaksanakan mulai bulan Mei 2007 sampai dengan Agustus 2007 di Bengkel Departemen Teknik Pertanian dan di Ecofarm, Fakultas Peternakan, Institut Pertanian Bogor. Persiapan peralatan uji dan pemeriksaan kondisi alat sebelum pengujian dilakukan di Bengkel Teknik Pertanian dan Pengujian kinerja di Ecofarm, Fakultas Peternakan, Kampus IPB Dramaga.
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Judul: Rancang Bangun Alat Pemerah Susu Sapi Otomatis dengan Pulsator Tipe Pegas
Abstrak: Milk is an important commodity for improving people nutrition. The main source of milk production is dairy cow. In Indonesia, milk production is dominated by local dairy herdsmen who are still applying milking manually by hand. Actually local dairy herdsmen can use milking machine which is built simple and appropriate with common components. This study aims at design and build automatic milking machine with spring type pulsator. This milking machine can be used by smallscale dairy herdsmen because it is easy to use and maintaince. By using this milking machine, milk is also expexted to be more hygienic. The main components to make up this milking machine are teat cups, spring type pulsator, DC Motor, AC-DC regulator, vacuum pump, milkcan, and frame. The specific distinction of this milking machine with the modern milking machine is no need a claw to connect 4 milk tubes on teat cups with 4 pulse tubes on pulsator. Claw’s function is not replaced by any component, but the milkcan itself is made as direct vacuum reservoir. Power source to run this milking machine is entirely using electricity. Vacuum pump requires 250 watt power to produce vacuum pressure up to 50 kPa at milkcan as vacuum reservoir. And DC motor requires DC voltage at 3-12 V with current 5A to drive the pulsator. Spring type pulsator can produce pulsation rate 60 cycle per minute with pulse ratio 2.5:1, which means the resting phase on teat cups is 2.5 times longer than massage phase. Testing result revealed that the performance of the machine has not produced milk as expexted. Vacuum flow rate which is produced by pump is less efficient if it works at very short time interval. While the resting phase, the pulsation chamber has just begun to connect with vacuum and the interval 5/7 second is too short to produce enough vacuum in order to open the teat cup liners. It is because the vacuum flow rate is nullified at a moment before, while the massage phase running.
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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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