Judul: Identifikasi Minyak Nabati Potensial sebagai Bahan Penyamak Kulit Samoa di Indonesia.
Abstrak: Minyak nabati memiliki potensi untuk dijadikan sebagai bahan penyamak kulit samoa menggantikan minyak ikan karena kelebihannya yang tidak berbau amis. Tujuan penelitian ini adalah untuk mengetahui minyak nabati yang paling berpotensi menjadi bahan penyamak kulit samoa di Indonesia. Minyak nabati yang diteliti adalah minyak jagung, minyak jarak kepyar, minyak jarak pagar, minyak kedelai, minyak kemiri, dan minyak biji karet. Pengujian sifat kimia minyak nabati dan analisis terhadap data total produksi di Indonesia menunjukkan bahwa minyak biji karet memiliki potensi terbesar di antara minyak-minyak tersebut. Minyak biji karet memiliki bilangan iod 146 g iod/g minyak. Jumlah produksi minyak biji karet di Indonesia diperkirakan dapat mencapai 572 360 ton per tahun. Minyak lain yang memiliki potensi besar adalah minyak kemiri.
Keyword: bilangan iod, kulit samoa, minyak nabati, penyamakan, produksi

Judul: Kajian Proses Pemurnian Minyak Nyamplung Sebagai Bahan Bakar Nabati.
Abstrak: Global energy crisis that occurred in the last decade gave the impact that was significant to increasing the fuel prices. Therefore, was required alternative energy development by using of renewable energy resources. One of the forest plants that have potential as raw materials for biofuels (BBN) is calophyllum. Calophyllum is potential to develop as non-food crops and land for growth does not compete with food crops. The use of the oil as a biofuel to form biodiesel, but the use of biodiesel from calophyllum still can not be applied operationally because the price is still higher than the price of diesel fuel. Therefore, the use of pure oil directly as biofuel becomes a more potent alternative to operationally. Technically crude calophyllum can be used as a biofuel substitute for diesel fuel, but the viscosity and free fatty acid levels still high and the presence of impurities compound remains a problem. This is necessary to study the purification and characterization of oils for this meet the required criteria and standards applicable. Oil refinery experienced two stages, namely the process of degumming and neutralization. Degumming is the sap or slime separation process that consists of phospolipid, proteins, carbohydrates, and water, while the neutralization was used to separate free fatty acids. Treatment of primary research consisted of two factors, namely phosphoric acid dose consisting of two levels: 0.2% and 0.3% (v/w) and concentration of NaOH solution which consists of three levels: 14°Be, 16°Be, and 18°Be.. The addition of caustic soda solution concentration had a significant impact on yield, acid number and content of free fatty acids, saponification numbers, peroxide number, ash content, and viscosity. While dosage phosphoric acid tends to decrease the value of ash content and viscosity, but did not affect any other parameters (yield, acid number and levels of free fatty acids, saponification numbers, and peroxide numbers).
Keyword: 

Judul: Analysis of M/G/1 Queue Model with Two Phases of Service and Bernoulli Feedback System
Abstrak: Model antrean M/G/1 dengan sistem feedback Bernoulli adalah model antrean dengan proses kedatangan mengikuti proses Poisson. Pada karya ilmiah ini dibahas sistem antrean M/G/1 dengan dua fase layanan. Setelah layanan pertama selesai, pelanggan dapat memilih untuk meninggalkan sistem dengan peluang ... dst, The M/G/1 queueing model with the Bernoulli feedback system is a queueing model with the arrival process following the Poisson process. In this manuscript M/G/1 queueing system with two phases of service is discussed. After the first service is completed, the customer can choose to leave the system with probability ... dst
Keyword: queue, Bernoulli, probability generating function, expected value