Judul: Pengaruh Penambahan Sludge pada Konversi Jerami Padi Menjadi Biogas
Abstrak: Penelitian ini bertujuan untuk mengetahui pengaruh penggunaan sludge pada konversi jerami padi menjadi biogas. Activated sludge digunakan sebagai substrat tambahan dengan dua komposisi yaitu 225 g pada jerami:sludge komposisi 5:3 dan 375 g pada jerami:sludge komposisi 3:5. Penelitian dilakukan secara batch selama 30 hari di dalam botol AMDK 600 ml dan dibuat terendam dalam aquarium dengan suhu terkontrol (32 °C). Parameter harian yaitu volume gas, 3 hari sekali (TS-TVS, COD, pH digestat dan lindi), dan berkala (Kadar C, N, dan P di awal dan akhir proses). Rancangan penelitian yang digunakan yaitu RAL dengan satu faktorial (komposisi) serta dua kali ulangan. Berdasarkan hasil penelitian terhadap fermentasi anaerobik jerami dengan starter sludge yang berasal dari instalasi pengolahan limbah cair (IPAL) industri dengan dua komposisi starter yang berbeda terhadap parameter volume, TS-TVS, COD, pH, kadar C, kadar N, dan kadar P didapatkan hasil sebagai berikut: Gas terbesar dihasilkan oleh jerami:sludge komposisi 3:5 yaitu sebesar 3.29714 L/kg Biomassa pada proses 1 dan 1.608 L/kg Biomassa pada proses 2. Adapun gas yang dihasilkan oleh penelitian Prajayana (2011) dengan bahan yang sama yaitu jerami padi menghasilkan gas sebesar 1.60 L/kg biomassa. Pada penelitian ini ternyata menghasilkan gas yang melebihi hasil tersebut. Hal ini bisa jadi disebabkan oleh kondisi sludge yang telah mengalami berbagai proses
Keyword: rice straw, sludge, digestate, leachate

Judul: Pengaruh Penambahan Sludge pada Konversi Jerami Padi Menjadi Biogas
Abstrak: The principal problems which have become the main focus of society are environmental problem and energy scarce. The main cause of the problems is the high consumption of fossil fuels. The purpose of this research is to find out effect of sludge composition on rice straw convertion to biogas. The fermentation were conducted with 1.5 L reactors and fermentation during 30 days. This aims to determine the effect of the use of sludge on the conversion of rice straw into biogas. Activated sludge were use as additional substrate with two composition, 225 g on the composition rice straw:sludge 5:3 and 375 g in composition rice straw:sludge 3:5. The maximum gas production was reached 18.382 L/kg TS in 1st running and 11.602 L/kg TS in 2nd running or 27.67816 L/g VS (1st running) and 18.93871 L/g VS (2nd running) by composition rice straw:sludge 3:5. The highest phosphate levels produced by rice straw:sludge 5:3 was 0.60 %, the carbon highest in rice straw:sludge 3:5 was 38.40 %, and nitrogen in rice straw:sludge 5:3 was 1.80 %.
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Judul: Construction of Strongly Optimal Binary Linear Code with Minimum Distance 9 and 11
Abstrak: A binary linear code of length n over q F is a subspace of n q F . A code has three parameters that attached to it, namely length, dimension, and minimum distance. A code with length n, dimension k and minimum distance d is often called [n, k, d ]-code. Usually, when two parameters are given, then we want to find a code that has the best value for the last parameter. Based on Gilbert- Varshamov bound, if a [n, k, d ]-code exists and can not be expanded, we call it a strongly optimal code. In this paper, we construct strongly optimal code with minimum distance 9 and 11. In constructing the code, we created a theorem and algorithm based on Gilbert-Varshamov bound before we implement the algorithm to MAPLE programming language. Because of computational limitations, the program can only construct up to k = 10 for d = 9 and k = 12 for d = 11.
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