Judul: Evaluasi kinerja tarik traktor kubota B6100 dengan bahan bakar cocodiesel
Abstrak: Perkembangan teknologi yang semakin cepat, dan kebutuhan manusia terhadap energi meningkat, maka muncul kekuatiran terhadap krisis energi jika masih menggunakan bahan bakar dari sumberdaya alam yang tidak dapat diperbarui. Bahan bakar yang dipakai pada traktor awalnya berasal dari solar. Belakangan ini kelangkaan bahan bakar fosil memicu melambungnya harga bahan bakar, maka bahan bakar nabati menjadi salah satu solusi untuk penaggulangan masalah ini. Sumber tenaga yang tersedia pada traktor dengan bahan bakar nabati seperti Cocodiesel diharapkan menjadi salah satu pemecahan masalah krisis bahan bakar. Pengertian cocodiesel adalah biodiesel yang dibuat dengan mereaksikan minyak kelapa dengan methanol, yang merupakan reaksi transenterifikasi dan menggunakan katalis pada suhu dan waktu tertentu. Minyak cocodiesel ini memiliki emisi rendah, titik nyalanya tinggi, dan senyawa mono alkil ester dari trigliserida ester cukup baik. Di samping itu, cocodiesel mempunyai sifat mudah terurai, tidak beracun, dan tidak mengeluarkan asap, sehingga aman dipakai serta ramah lingkungan.
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Judul: Kajian Kinerja Tarik Traktor Tangan dengan Menggunakan Bahan Bakar Biodiesel Minyak Sawit
Abstrak: This study discusses the tractive performance of hand tractor (drawbar pull, drawbar power, and cultivated field capacity using mouldboard plough) fueled with biodiesel from palm oil and analysed the economics of biodiesel implementation as fuel. The tests were performed on Huanghai DF-12L. In this study, palm oil biodiesel are tested as diesel fuels in neat (B100) and blended forms with diesel fuels commercial (B20, B40, B60, B80); the performance of hand tractor using biodiesel in neat and blended forms compared with using diesel fuels commercial. In order to determine the traction performance characteristic, hand tractor operated at constant engine speed mode 2000 rpm (the full load condition of the engine). Hand tractor loaded by Yanmar YM330T (four wheel tractor) that operated at five levels engine speed mode that is 1200 – 2000 rpm with 200 rpm increments. The tractive tests were performed on grass track and concrete track, whereas cultivation performed in dry land. The results indicated that drawbar pull and drawbar power of hand tractor on grass track and concrete track were uniformed (especially on grass track); hand tractor fueled with B40 and B100 showed increase trend compared to diesel fuels commercial, whereas other fuels tested showed decreased trend. Otherwise the cultivated field capacity of hand tractor fueled biodiesel from palm oil closely followed those of fueled with diesel fuels commercial. Based on this study, the implementation of biodiesel from palm oil either neat or blended forms are suitable as alternative diesel fuel for hand tractor although more expensive compared to diesel fuels commercial.
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Judul: Light Microscope Study of ConnectiveTissue in The Spleen of Common Rousette Bat (Rousettus amplexicaudatus)
Abstrak: The spleen is the largest lymphoid organ. As a secondary lymphoid organ, in addition to its immune function, the spleen also has functions as blood filtration, storage, and hematopoiesis. The spleen has different morphologies between species that support different physiological functions, one of which is the difference in the structure of the capsule and trabeculae. Capsule and trabeculae of the spleen generally consist of connective tissue and smooth muscle. The thickness of smooth muscle composed together with connective tissue in the capsule and trabecula determines the function of the spleen that is divided spleen into three storage, defense, and intermediate. Bats are the reservoir of various zoonotic diseases. Bats are thought to have unique immune systems compared to other mammals but the characteristics of its immune organs such as the spleen have never been studied before. This study was conducted to examine the characteristics of capsulae and trabecula of the Common Rousette (Rousettus amplexicaudatus).
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