Judul: Effect of organic compound and mercury on community structure and secondary productivity trichoptera larvae in Ciliwung River
Abstrak: Ciliwung River is one of the big rivers in West Java Province which is polluted by organic compound and mercury. Pollution in Ciliwung River could disturb the ecological balance of Trichoptera larvae. The purpose of this study was to reveal the influence of organic compound and mercury contamination on community structure, ecology feeding, secondary productivity of Trichoptera larvae and establish a local biocriteria using multimetric concept. Research was conducted in six stations on high gradient Ciliwung River segment. Trichoptera larvae were collected using surber net with five replications in each study sites. High of organic pollution, mercury contamination, and habitat degradation could decrease number of genus Trichoptera larvae (7-2), diversity index (2.8-0 bits per individu), while increase secondary productivity of Cheumatopsyche sp. larvae (5.9-81.5 g m-2 year-1). Ecology feeding was dominated by filtering collector while disturbance was increasing. Four biological metrics (total taxa number, scores of Stream Invertebrate Grade Number-Average (SIGNAL), % abundance of three dominant taxa, number of sensitive taxa) was successfully created to be a local biocriteria which was called Trichoptera biotic index (IBT). Range the index values were 26-28 classified as least disturbance, 17-18 low disturbance, 7-16 medium disturbance, and 4-6 severe disturbance. Development and refinement of IBT in the future can be used to monitor and evaluate rivers quality in Indonesia especially for high gradient river.
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Judul: Pengaruh Unsur Hara (N Dan P) Terhadap Biomassa Dan Struktur Komunitas Perifiton Studi Kasus Sungai Ciliwung
Abstrak: Research on the effect of nutrient to the structure of periphyton communities in Ciliwung river has been conducted from December 2010 to May 2011 at four stations; Gn. Mas, Kp. Pensiunan, Kp. Jogjogan, and Cibinong which reflected the of input of anthropogenic pollutant. This study aims to determine the relationship between nutrients (N and P) concentration and the structure changes of periphyton community in order to determine the ecological condition of Ciliwung River. The results of this study are expected to be useful to make a policy in the management of ecological disturbance of Ciliwung River based on pollutants loads and environmental changes due antropogenic activity. Water quality Ciliwung River was evaluated from the condition of habitats, pollution levels and the conditions of periphyton integrity to observed the actual condition of the aquatic environment. The results showed optimal habitat conditions was observed in Gn. Mas while other stations condition were marginal (Kp. Pensiunan, Kp. Jogjogan and Cibinong). Based on pollution level category, Gn. Mas and Kp. Pensiunan was unpolluted, while Kp. Jogjogan and Cibinong was slightly polluted and moderately polluted respectively. The results obtained 83 species of periphyton consisted of Bacillariophyceae (44 species), Chlorophyceae (20 species), Cyanophyceae (14 species), Rhodophyceae (1 species), Xantophyceae (2 species) and Dinophyceae (2 species). Based on the abundance of periphyton, PIBI score obtained was almost the same Gn. Mas (95,97), Kp. Pensiunan (84,65), Kp. Jogjogan (93,57) and Cibinong (83,83). CCA ordination of the results obtained a clear grouping among the research station. While the results from a combination of habitat conditions, the level of pollution and its PIBI value confirm that water conditions are still good.
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Judul: Konstruksi aritmetika kurva eliptik F(2m) supersingular dan non-supersingular untuk skema kunci publik ElGamal
Abstrak: Algoritme ElGamal adalah salah satu algoritme kunci publik dengan aritmetik modular p yang mempunyai struktur grip siklik Z(p). Tingkat keanaman algoritme ini terletak pada pemecahan masalah logaritme diskret dari Z(p). Akan tetapi, tingkat keamanan tadi tahun ke tahun semakin menurun yang disebabkan kemampuan pemecahan algoritme diskret semakin meningkat. Untuk memenuhi tingkat keamanan yang memadai dibutuhkan p yang cukup besar yang menyebabkan proses enkripsi dan dekripsi menjadi lambat.
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