Judul: Laju Pertumbuhan Biomassa dan Uji Kadar Karbohidrat Gelidium latifolium pada Kultivasi Menggunakan Sistem Injeksi Co2.
Abstrak: Macro algae is a potential feedstock for bioethanol energy development. The species of macro algae are very diverse in nature so that need to explore and research about biological characteristic, such as biomass growth rate. This research analyzed the levels of carbohydrate yield and measure the biomass growth rate of Gelidium latifolium on carbon dioxide (CO2) injection as source of photosynthesis The research was conducted at Laboratory of Microbiology, Surfactant and Bioenergy Research Center (SBRC) of Bogor Agricultural University, Baranangsiang, on February until July 2012. Macro algae Gelidium latifolium is taken from Ujung Kulon, Banten. Experimental design used is Randomized Block Design (RBD) and Duncan Test with some treatments, namely control, P1 injection of 2.000 cc (200 cc x 10 minutes per 3 days) and aeration, P2 injection of 3.000 cc (200 cc x 15 minutes per 3 days) and aeration, P3 injection of 2.000 cc (200 cc x 10 minutes per 3 days) without aeration, and P4 injection of 3.000 cc (200 cc x 15 minutes per 3 days) without aeration. Initial weight of the Gelidium latifolium cultivation samples are similar, 3 grams and time of cultivation is 42 days. The results showed that the highest average wet weight at the end of cultivation is P2 (4.16 ± 0.14 gram), P1 (4.03 ± 0.12 gram), P3 (0.23 ± 3.66 gram), control (3.54 ± 0.06 gram), and P4 (40.23 ± 3.26 gram). The daily growth rate value of Gelidium latifolium during study ranged from 0.02 to 1.06%. The highest daily growth rate of all treatments occurred in P2 is 1.06 ± 0.14% at 4th week, while the lowest daily growth rate of all treatments occurred in P4 is 0.02 ± 0.85% in the 2nd week . The weight of P4 treatment macro algae decreased drastically in the 2nd week caused by fungi that grow around the thallus. The different treatments make significant effect on the growth rate of Gelidium latifolium, so need a test to determine effect of treatments to growth rate at 95% confidence interval. Carbohydrate yield before cultivation is 18.23%, while after cultivation for control carbohydrate yield is 19.40%, P1 is 20.40%, P2 is 19.40%, P3 is 16.87%, and P4 is 16.40% .
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Judul: Produksi lipid dan karbohidrat ganggang mikro asal sawah dan perairan tawar yang dikultivasi pada skala lapang
Abstrak: Production of bioenergy as an alternative for oil fuel requires biomass as raw material. With an extremely rapid growth rate, microalgae is potential to be developed as a source of bioenergy by extracting lipids and carbohydrates from its biomass. This research was initiated by a laboratory-scale cultivation of 4 isolates of microalgae (ICBB 9111, ICBB 9112, ICBB 9113, and ICBB 9114) in 50 ml medium with 5 different concentrations, i.e. 0.75 times the standard media M4 composition (0.75 M4), M4, 1.25 M4, 1.50 M4, and 1.75 M4. The composition of M4 standard media (g/L): 1.5 NaNO3, 0.049 K2HPO4, 0.0366 MgSO4, 0.0271 CaCl2, 0.006 citric acid, 0.006 Fe-ammonium citrate, 0.001 EDTA, 0.02 Na2CO3 and 1 ml micro nutrient with composition (g/L): 2.86 H3BO3, 0.1485 MnCl2, 0.1245 ZnSO4, 0.0506 Na2MoO4.2H2O, 0.0506 CuSO4, and 0.043 CoCl2.6H2O. The laboratory scale growth-rates of microalgae at different compositions of standard media were varied. Based on the results of analysis of variance, Duncan's Multiple Range Test, and growth chart, the optimum medium for the field-scale cultivation were 0.75 M4 for microalgae ICBB 9112 and ICBB 9114, and M4 for microalgae ICBB 9111 and ICBB 9113. The growth rate of microalgae at field scale was faster than those at laboratory one. The average biomass productivity of microalgae ICBB 9111, ICBB 9112, ICBB 9113, and ICBB 9114 after cultivated for 2 days at field scale were, respectively, 0.28, 0.21, 0.26, and 12.32 g/L. The highest lipid production was produced by isolate ICBB 9114 (32% w/w) at 0.75 M4 medium, and the highest carbohydrate production was obtained from isolate ICBB 9113 (44% w/w) at M4 media. This result indicates that when the microalgae lipid production is high, the corresponding carbohydrate production is lower and vice versa.
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Judul: Grup dan Homomorfisma Grup pada Rubik Revenge
Abstrak: Rubik cube is a kind of puzzle game. A player must arrange rubik sides, which have been disordered, back to the position where every side has the same colour. This paper does not focus on the settlement solution, but instead on proving the existence of a group homomorphism between rubik movement group and S96 symmetric permutation group in rubik revenge. Firstly, it has been proved that rubik movement set is a group. Then, it also has been proved that the M set, which contains numeric labels of 1 until 96 in cubinos sides, is S96 symmetric permutation group.
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