Judul: Uji Kualitas Fisik Pellet Berbasis Jerami Jagung Sebagai Pakan Sumber Serat untuk Ternak Ruminansia
Abstrak: Pemanfaatan produk samping (by product) tanaman jagung seperti jerami jagung yang tersedia secara melimpah dapat menjadi alternatif bahan baku pakan pengganti hijauan yang ketersediaannya saat ini sudah semakin terbatas. Namun, jerami jagung memiliki keterbatasan yaitu, kandungan zat makanan yang rendah, kecernaan yang rendah serta bersifat bulky (voluminous) sehingga tidak efisien jika diangkut ke daerah lain. Untuk meningkatkan nilai zat makanan jerami jagung tersebut dapat dicampur dengan bahan pakan lain sebagai sumber protein dan energi seperti leguminosa dan jagung. Salah satu leguminosa yang memiliki kandungan protein yang tinggi dan memiliki produksi tinggi adalah legum Indigofera sp. selain lebih efisien, pellet lebih mudah dalam penanganan (handling) dan transportasi. Untuk menghasilkan pakan bentuk pellet, maka kajian tentang sifat-sifat fisik bahan sangat diperlukan seperti kerapatan tumpukan, kerapatan pemadatan tumpukan, berat jenis, sudut tumpukan, dan laju alir. Sementara itu, untuk mengevaluasi kualitas fisik pellet dapat diukur dari pellet durability index (PDI). Penelitian ini bertujuan untuk mengetahui sifat fisik bahan baku pellet dan mengetahui pengaruh komposisi bahan baku pellet dan ukuran die terhadap kualitas fisik pellet. Penelitian ini menggunakan rancangan acak lengkap faktorial dengan model 4 x 2 dengan 3 ulangan. Faktor A merupakan komposisi bahan pellet dengan perlakuan A1 (100% jerami jagung), A2 ( 75% jerami jagung + 20% Indigofera Sp. + 5 % jagung giling), A3 ( 75% jerami jagung + 15% Indigofera Sp. + 10 % jagung giling), A4 ( 75% jerami jagung + 10% Indigofera Sp. + 15 % jagung giling), dan faktor B adalah ukuran die yaitu 5 dan 8 mm. Peubah yang diamati adalah kerapatan tumpukan, kerapatan pemadatan tumpukan, berat jenis, sudut tumpukan, laju alir, dan pellet durability index (PDI). Data analisa menggunakan ANOVA, apabila terdapat perbedaan yang nyata akan dilanjutkan menggunakan uji Duncan (Steel dan Torrie, 1993).
Keyword: corn plant by product, lignoselulose by product, processing technology, Completely Randomized Design with factorial, bulk density, specific density, specific density, specific density, pellet durability index

Judul: Uji Kualitas Sifat Fisik dan Daya Simpan Pellet yang Mengandung Klobot Jagung dan Limbah Tanaman Ubi Jalar sebagai Substitusi Daun Rumput Gajah.
Abstrak: This study aims measured the quality of the physical properties and storage period of pellet. Food resources in the form of pellet with corn husk and sweet potato by-product as a substitute for the Pennisetum purpureum leaves. Model experiments used a Completely Randomized Design with (4x4) factorial and 4 replicates. The first factor was the rate of substitution consist of R0 (18% Pennisetum purpureum leaves + 82% concentrate), R1 (12% Pennisetum purpureum leaves + 3% corn husk + 3% sweet potato by-product + 82% concentrate), R2 (6% Pennisetum purpureum leaves + 6% corn husk + 6% sweet potato by-product + 82% concentrate), R3 (9% corn husk + 9% sweet potato by-product + 82% concentrate). The second factor was the storage period consist of Q1 (0 weeks), Q2 (2 weeks), Q3 (4 weeks) and Q4 (6 weeks) with four replications. The variables observed were water content (%), density (gr/cm3), loose bulk density (gr/cm3), compacted bulk density (gr/cm3), single of repose (), water activity, particle size (mm) and pellet durability index (%). Data were analyzed by analysis of variance and significant results with orthogonal contrast test. The results showed that corn husk and sweet potato by-product as a substitute for the Pennisetum purpureum leaves and storage period of significant effect (P<0.01). Differences of each level of substitution affecting for water content, water activity, particle size, angle of repose and loose bulk density. Interaction of two factors were significant effect (P< 0.01). According to change of pellet water activity, the best results from first factor were R1. While the second factor as good as the rations not stored more than 2 weeks.
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Judul: Tinjauan Matematis pada Model Makroskopik dan Mikroskopik Arus Lalu-lintas
Abstrak: Traffic flow phenomenon can be described through mathematical model such as continuous dynamic model with an ordinary differential equation so that it can be solved with integral factors. In this paper three simple models of traffic flow are discussed, i.e, two macroscopic and one microscopic models. Macroscopic model formulates dynamics of the traffic flow that occurs on a large number of vehicles on a road. While the microscopic model explains drivers’ behavior in their interaction with other vehicles ahead, i.e, car-following model. This paper shows the existence of ordinary differential equation found in the traffic flow model and indicates some different representations in the context of the same model. It also reviews a simple model of traffic flow along a single link, which leads to some unexpected results, i.e, it can express the solution model in term of link outflows as well as trip time. In the microscopic model, simulation is done to illustrate the behavior of the drivers with a sensitivity coefficient as a benchmark parameter.
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