Judul: Pembuatan Biopelet dari Cangkang Kelapa Sawit dengan Penambahan Arang Cangkang Sawit dan Serabut Sawit sebagai Bahan Bakar Alternatif Terbarukan
Abstrak: Biopellet is one of an alternative energy for rural community. The abundance of palm shell and palm fiber is a potential source of biomass that can be converted into biomass pellet (biopellet). Pelletization can improve the quality and burning characteristic of the biomass. The purpose of this Fesearch was to learn the utilization of palm shell and fiber into biopellet production and to know the affectation of addition the palm shell charcoal and palm fiber. The research begun with an analysis of physic-chemical properties contained in the raw material. Then the result continued by analysis of tombustion characteristic. Based on the physic-chemical properties and the combustion Characteristics; biopellet of palm shell that contained 80% of palm shell and 20% of palm shell charcoal has the best quality. It has 0.47% of moisture content; 9.83% of ash content; 55.34% of Polatile matter; 34.84% of fixed carbon content; 5,265.92 kcal/kg of the heating value; 1,260.30 kg/m² f bulk density; and 82.09 kg/cm of strength pressure. The consumption rate of the best formulation biopellet was 1.39 kg/jam and the combustion efficient was 11.59%. The production of palm shell biopellet on a laboratory scale produced yield of 11.54%. Energy input for this process is 101,751.86 cal and energy output is 9,794.61 kcal. Biopellet increased the heating value of palm shell for 25.55% or 7,008.84 kcal/kg.
Keyword: Palm shell, Palm fiber, Biopellet, Charcoal, Carbonization

Judul: Karakteristik Pelet Campuran Tandan Kosong Kelapa Sawit :(Elaeis guineensis jacq.) dan Arang
Abstrak: Oil palm empty fruit bunches (EFB) is very abundant in Indonesia. It has huge potential to be used as renewable energy. This study tries to assess the use of EFB as biopellet to be used as alternative renewable fuel. Pellets are made from mixing oil palm empty fruit bunch powder and oil palm empty fruit bunch char at a ratio of 0, 10, and 20% respectively. Biopellet is molded using pellet mill machine that produces cylindrical shaped pellets with a diameter of 0.4 cm and a length of + 4 cm. The result of the study indicates that adding char could increase the calorific value of pellets. The calorific value of pellets to which 10 and 20% of char has been added will produce pellets that have a calorific value of 17,21 MJ/kg and 17,38 MJ/kg respectively. Meanwhile the calorific value of dry empty palm oil bunch feedstock and its pellets are 16,21 MJ/kg and 17,38 MJ/kg respectively. In addition to calorific value, adding char to pellets made from oil palm empty fruit bunched will reduce the moisture and ash contents and improve the bulk density of pellets. In general, the quality of biopellets that have been mixed with 20% of char is capable of meeting the French standard as regard to diameter size, length size, moisture content, and calorific value parameters, on the other hand as regard to ash content, and bulk density, all biopellet types still hasn’t been able to fulfill the requirements.
Keyword: alternative renewable energy, charcoal, calorific value, biopellet, oil palm empty fruit bunch

Judul: Invers Drazin dari Matriks Toeplitz Singular
Abstrak: Matriks Toeplitz adalah matriks yang setiap unsur pada diagonal utama bernilai sama dan setiap unsur pada subdiagonal yang bersesuaian dengan diagonal utama juga bernilai sama. Matriks singular adalah matriks yang tidak bisa ditentukan inversnya. Akan tetapi, dapat diupayakan untuk ditentukan inversnya menggunakan invers matriks yang diperumum. Invers Drazin merupakan salah satu jenis invers matriks yang diperumum. Pada karya ilmiah ini ditentukan invers Drazin dari matriks Toeplitz singular dengan menggunakan metode Leverrier Faddeev. Kemudian, ditentukan invers Drazin dari matriks Toeplitz singular yang direpresentasikan sebagai penjumlahan segitiga bawah dan segitiga atas matriks Toeplitz berdasar pada teorema Gohberg dan Semencul., Toeplitz matrix is a matrix in with element on the main diagonal has the same value and on the subdiagonal corresponding to the main diagonal also has the same value. Singular matrix is a matrix that has no inverse. However, it can be attempted to determine the inverse using a generalized inverse matrix. Inverse Drazin is a type of generalized matrix inverse. This paper discussed the inverse Drazin for a singular Toeplitz matrix using the Leverrier Faddeev method. Then, the Drazin inverse of the singular Toeplitz matrix which is represented as a sum of products of lower and upper triangular Toeplitz matrix based on Gohberg and Semencul theorem.
Keyword: inverse Drazine, singular Toeplitz matrix