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 Biopelet Dari Campuran Serbuk Kayu Sengon Dengan Arang Sekam Padi Sebagai Bahan Bakar Alternatif Terbarukan
Abstrak: Biopellet is one of the alternative fuels which could substitute fossil fuel. The production of biopellet could be made from natural resources based lignocelluloses materials such as albisia sawdust and rice husk charcoal. The objective of this research was to analyze the characteristics of biopellet obtained of the mixture albisia sawdust and rice husk. The compositions of a mixture in this research are as follows 20% : 80%, 40% : 60%, 60% : 40%, 80% : 20%, as well as 100% of albisia sawdust. The test of biopellet included moisture content, density, volatile matters, ash substances, fixed carbon, calorie value and firmness which was based on commercial standard. The result of this research showed that the addition of rice husk charcoal into biopellet derived from albisia sawdust could not only decrease moisture content, but also that addition could increase ash percentages and calorie value. Although there was increasing calorie value, the addition of rice husk charcoal generated the inappropriateness of quality standard for ash percentages. The best quality of biopellet was composed with 100 % albisia sawdust which moisture content, density and calorie value were in accordance with French quality standard (ITEBE).
Keyword: quality standard, rice husk, albisia sawdust, Biopellet

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