Judul: Floating Treatment Wetlands (FTW) System that is  Effective in Reducing Catfish (Clarias sp.) Aquaculture Wastewater Pollutants
Abstrak: Air limbah kegiatan kolam pemeliharaan ikan lele secara konvensional dengan pelet sebagai pakan utama akan menghasilkan karakteristik air limbah yang tinggi akan konsentrasi nitrogen, fosfor dan bahan organik. Masuknya limbah kolam pemeliharaan ikan lele secara langsung ke perairan akan mengakibatkan pencemaran perairan. Penerapan Floating Treatment Wetlands (FTW) sebagai teknologi pengolahan limbah pada sistem budidaya resirkulasi diketahui efektif dalam menyisihkan beban pencemar nitrogen, fosfor dan bahan organik. Vetiveria sp. merupakan tanaman yang efektif menyisihkan bahan pencemar dan memiliki toleransi tinggi terhadap kondisi ekstrem. Pada FTW, akar Vetiveria sp. menyerap nutrien yang berasal dari proses dekomposisi bahan organik pakan ikan lele. Penyerapan nutrien ini mendukung pertumbuhan Vetiveria sp. Penelitian ini bertujuan untuk menurunkan konsentrasi beban pencemar dan mendapatkan rasio efektif antara volume sistem pengolahan limbah FTW dan volume total air sistem resirkulasi kolam lele dengan memanfaatkan Vetiveria sp. Beberapa rasio volume FTW digunakan untuk menentukan sistem FTW yang efektif dalam menurunkan kandungan pencemar yang dihasilkan dari kolam produksi ikan lele. Penelitian dilakukan secara eksperimental pada rumah kaca dengan menggunakan kolam fiber yang terdiri atas kolam ikan lele, tandon inlet, kolam FTW1 (rasio 0,181), kolam FTW2 (rasio 0,362), kolam FTW3 (rasio 0,543), kolam FTW4 (rasio 0,725). Hasil penelitian menunjukkan bahwa sebagian besar konsentrasi beban pencemar mengalami penurunan berturut-turut pada kolam ikan lele, kolam FTW1 (rasio 0,181), kolam FTW2 (rasio 0,362), kolam FTW3 (rasio 0,543), dan kolam FTW4 (rasio 0,725). Waktu pemeliharaan yang berbeda akan memengaruhi TAN; COD; DO dan pH secara signifikan (P<0,05). Perbedaan perlakuan rasio FTW memengaruhi TAN; COD; TSS; TP; nitrat dan ortofosfat secara signifikan (P<0,05). Interaksi rasio FTW dengan waktu pemeliharaan akan memengaruhi TAN; TSS; TP secara signifikan (P<0,05). Persentase penyisihan TAN; COD; TSS; TP; nitrat; fosfat; TN terbesar berada pada kolam FTW4 (rasio 0,725) yaitu sebesar 88,54%; 49,35%; 85,68%; 91,30%; 83,85%; 61,46%; 44,68%. FTW dengan rasio 0,543 pada waktu pemeliharaan 4-8 minggu ditetapkan sebagai perlakuan yang lebih baik dalam menyisihkan beban pencemar limbah cair kolam pemeliharaan ikan lele dibandingkan perlakuan lainya., Conventional catfish rearing activities in ponds that utilize fish pellets as the main feed usually generate wastewater characteristics with high concentrations of nitrogen, phosphorus, and organic matter. The waste effluent of catfish rearing pond directly discharged into the waters results in water pollution. The application of Floating Treatment Wetlands (FTW) as a waste processing technology in recirculating cultivation systems is considered effective in eliminating the pollutant content of nitrogen, phosphorus, and organic matter. Vetiveria sp. is a perennial grass-like plant that effectively removes pollutants and has a high tolerance for extreme conditions. In FTW, the roots of Vetiveria sp. absorb nutrients from the decomposition process of organic material in catfish feed. The absorption of these nutrients supports the growth of Vetiveria sp. This research aims to reduce the concentration of pollutant content and obtain an effective ratio between the volume of the FTW waste processing system and the total water volume of the catfish pond recirculation system by utilizing Vetiveria sp. The research was carried out experimentally in a greenhouse using fiber ponds consisting of catfish ponds, inlet reservoirs, pond of FTW1 (ratio 0.181), FTW2 (ratio 0.362), FTW3 (ratio 0.543),
Keyword: Floating treatment wetlands, Pollutants load, Catfish waste, Vetiveria sp.

Judul: Pemanfaatan Rumput Vetiver (Vetiveria zizanioides) sebagai Fitoremediator dalam Pengolahan Limbah Budidaya Lele Sangkuriang (Clarias gariepinus).
Abstrak: Aquaponic is a combination of aquaculture and plant using recirculation system. Sangkuriang catfish (Clarias gariepinus) and vetiver (Vetiveria zizanioides) were used as experimental media of phytoremediation. This research aims to treat and utilize organic wastewater of sangkuriang catfish use vetiver grass. Measure the growth of sangkuriang catfish and vetiver in the recirculation system. Analysis of the data used was In Time Completely Randomized Design to determine the effect of treatment of vetiver grass on water quality parameters temperature, pH, dissolved oxygen, ammonia, nitrate, and orthophosphate. Biological parameters measured include SR, SGR, length and weight of fish growth, and growth of vetiver grass length. The result showed that the use of vetiver could reduce levels of ammonia up to 88,44%, nitrate 75,34%, and orthophosphate 96%. Spearman Rank Correlation test of aquarium treatment shows positive correlation between pH with nitrate and orthophosphate, and between nitrate and orthophospahate.
Keyword: Aquaponics, phytoremediation, sangkuriang catfish, vetiver, water quality

Judul: Metrik Einstein (Anti-) Self-Dual Berdimensi Empat dengan Metode Cartan
Abstrak: Gravitational field equation can be formulated in differential forms (differential geometry), which describes gravity as a manifestation of the curvature of space-time. Curvature of space-time is characterized by a metric that satisfies the gravitational field equation. With differential forms it can be formulated the (anti-) self-dual Einstein equation, which is a modification of the Cartan structure in (anti-) self-dual basis. Calculation of (anti-) self-dual metric with (anti-) self-dual Einstein equation is simpler than the calculation using Christoffel symbols.
Keyword: