Judul: Production of spirulina for decreasing pollution level of palm oil mill effluent in continous photobioreactor
Abstrak: Spirulina platensis could be grown on Palm Oil Mill Effluent (POME) to produce algal biomass and to reduce pollution level of the effluent. The objective of this research was to determine the growth rate of S. platensis and the reduction rate of pollution level of POME on semi-continuous photobioreactor. Preliminary research was conducted by growing S. platensis on POME media with various concentration, namely 25%, 50%, 75%, and 90% POME by batch system. Results of the preliminary research could be used to obtain the optimum growth period as a reference for the main research. The main research on the growth of S. platensis was conducted on photobioreactor that adjusted with their feeding rate of media containing a mixtime of POME and synthetic media at optimum concentration. Feeding rate was set up at 1 drop/ 5 sec. (dilution rate of 0.03 hr -1), 1 drop/ 10 sec. (dilution rate of 0.015 hr -1), and 1 drop/ 15 sec. (dilution rate of 0.01 hr -1). The main research was conducted with 1.2 liter-capacity photobioreactor with POME media at optimum concentration after optimum growth. For optimum dilution rate, the experiment was scaled up eight times using 10-liter-capacity photobioreactor. The parameter observed was Total Dissolved Solid (TDS), Fixed Dissolved Solid (FDS), Volatile Dissolved Solid as approximate value of Total Carbon (TC), Optical Density (OD) at λ 480 nm (OD 480 nm), Dissolved Oxygen (DO), Biological Oxygen Demand (BOD), and Chemical Oxygen Demand (COD).
Keyword: 

Judul: Potensi Pemanfaatan Limbah Palm Oil Mill Effluent (POME) sebagai Media Kultivasi Mikroalga Chlorococcum dan Dictyosphaerium
Abstrak: Limbah Plam Oil Mill Effluent (POME) memiliki kandungan nutrisi cukup besar yang dapat menunjang pertumbuhan mikroalga. Penelitian ini bertujuan untuk membandingkan pengaruh limbah POME sebagai media kultivasi terhadap pertumbuhan Chlorococcum dan Dictyosphaerium. Ada 2 mikroalga dan ada 3 media yaitu kontrol, POME 20% dan 50% selama periode kultivasi 11 hari. Analisis yang dilakukan adalah perhitungan kepadatan sel, kadar protein, karbohidrat. Hasil menunjukkan bahwa kepadatan sel Chlorococcum dan Dictyosphaerium tertinggi pada POME konsentrasi 50%. Kadar protein tertinggi Chlorococcum dan Dictyosphaerium raw POME berturut – turut sebesar 62943 ± 0.03 ppm dan 59276 ± 0.01 ppm. Kadar protein tertinggi pada Chlorococcum dan Dictyosphaerium treated POME berturut – turut sebesar 37310 ± 0.33 ppm dan 40010 ± 0.06 ppm. Kadar karbohidrat tertinggi pada Chlorococcum dan Dictyosphaerium raw POME berturut – turut sebesar 2143 ± 0.03 ppm dan 1996 ± 0.09 ppm. Kadar karbohidrat tertinggi pada Chlorococcum dan Dictyosphaerium treated POME berturut – turut 1343 ± 0.01 ppm dan 1046 ± 0.03 ppm. Perlakuan POME 50% memiliki pengaruh yang berbeda nyata terhadap kontrol.
Keyword: Chlorococcum, Dictyosphaerium, Kultivasi, POME

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.
Keyword: