Judul: Pengembangan proses pembuatan biodiesel jarak pagar (Jatropha curcas L.) melalui transesterifikasi In Situ, katalis heterogen dan detoksifikasi, Process development of biodiesel production from jatropha curcas L. via in situ transesterification, heterogeneous catalysis and detoxification
Abstrak: Semenjak dikeluarkannya kebijakan pemerintah mengenai energi terbarukan berdasarkan Peraturan Pemerintah omor 5 tahun 2006 dan Instruksi Presiden omor 1 tahun 2006, program nasional pengembangan tanaman jarak pagar sebagai sumber minyak nabati untuk pembuatan biodiesel digerakkan secara besar-besaran. Namun demikian, program pengembangan tanaman jarak pagar tidak berjalan sesuai dengan yang diharapkan karena petani dan investor merasa bahwa investasi pada komoditas ini tidak layak secara ekonomis. Salah satu masalah yang dihadapi oleh petani adalah rendahnya nilai jual biji jarak pagar yang mereka hasilkan. Masalah rendahnya nilai jual ini dapat diatasi apabila biji jarak dilihat tidak saja sebagai penghasil minyak, namun juga dilihar potensinya sebagai sumber pakan kaya protein. Dengan perubahan cara pandang itu, maka harga biji jarak pagar per kilogram diharapkan dapat dinaikkan sehingga komoditas ini menjadi menarik untuk diusahakan sebagai sumber minyak nabati untuk dikonversi menjadi biodiesel melalui proses transestrifikasi., Jatropha curcas is one source of vegetable oils to be developed as a prospective raw material of biodiesel production. Beside oil, its seed cakes, by-product of oil extraction, contains high protein which is potential for feed source, if the toxic compounds can be removed. Based on free fatty acid (FFA) content of the oil, jatropha can be distinguished into two types: jatropha that has oil with low FFA content (1.03 ± 0,10%) and one that has high content of FFA (± 6.99 %).
Keyword: Jatropha curcas, Calcium oxide, Techno-economic, Life cycle assassment, Biodiesel production, Heterogeneous catalysis

Judul: Study of biodiesel production by in situ transesterification of jatropha seed (jatropha curcas l.) on pilot scale
Abstrak: At present, energy demands have been steadily increasing along with growth of human population and industrialization. Common sources of energy are fossil-based fuels. This growing consumption of energy has rapidly depleted non-renewable sources of energy. The increasing cost and depletion of fossil fuels have motivated researchers to find an alternative source of renewable energy. Moreover, there are many disadvantages of fossil-based fuels, such as atmospheric pollution and environmental issues. Biodiesel (fatty acids methyl esters, FAME) is a promising alternative fuel to replace petroleum-based diesel that is obtained from renewable sources as vegetable oil, animal fat, and waste cooking oil. Vegetable oil are more suitable source for biodiesel production compared to animal fat and waste cooking since they are renewable in nature. Jatropha curcas L. (JCL) is an acceptable choice for biodiesel production because it is non-edible and can be easily grown. Conventional production of biodiesel from Jatropha seeds involve two main processing steps : oil extraction and transesterification to FAME. In this study, feasibility in situ transesterification of Jatropha seeds was investigated on pilot plant. It was found that methanol/hexane/seed ratio effected the yield significantly. With the following reaction conditions: reaction periode 6 hours, 600 rpm stiring speed, 400C reaction temperature, methanol/hexane/seed ratio 3:3:1, and 7 wt% of KOH, the biodiesel yield can reached 89.19%. This single step of in situ alkaline transesterification process therefore can be a potential route for biodiesel production that reduces processing steps and cost.
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Judul: Grup dan Homomorfisma Grup pada Rubik Revenge
Abstrak: Rubik cube is a kind of puzzle game. A player must arrange rubik sides, which have been disordered, back to the position where every side has the same colour. This paper does not focus on the settlement solution, but instead on proving the existence of a group homomorphism between rubik movement group and S96 symmetric permutation group in rubik revenge. Firstly, it has been proved that rubik movement set is a group. Then, it also has been proved that the M set, which contains numeric labels of 1 until 96 in cubinos sides, is S96 symmetric permutation group.
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