Judul: Efektivitas Bakteri Thiobacillus spp. dalam Mendekomposisi Bahan Organik pada Media Air Laut
Abstrak: Akumulasi bahan organik di dalam perairan tambak budidaya dapat mengakibatkan terjadinya defisit oksigen serta dapat mengakibatkan udang mengalami tekanan secara fisiologis, sehingga menjadi rentan terhadap serangan penyakit. Penelitian ini bertujuan untuk mengetahui efektivitas bakteri Thiobacillus spp. dalam mendekomposisi bahan organik pada media air laut sebagai simulasi air tambak. Penelitian ini menggunakan Rancangan Acak Lengkap (RAL) in time dengan 4 perlakuan yaitu tanpa penambahan probiotik (kontrol), penambahan probiotik dalam media teknis molase sebanyak 5 ppm (P1), penambahan probiotik dalam media teknis molase sebanyak 10 ppm (P2), dan penambahan probiotik dalam media teknis molase sebanyak 15 ppm (P3). Setiap perlakuan dilakukan pengulangan sebanyak tiga kali. Parameter yang diamati yaitu kualitas air dan total bakteri. Penurunan BOD5 paling signifikan mencapai 53,4% terdapat pada P3, yaitu sebesar 86,4 ± 19,2 mg/L sedangkan penurunan TOM paling signifikan terdapat pada P1 yaitu sebesar 33,7 ± 2,9 mg/L. Bakteri Thiobacillus spp. terbukti cukup efektif memberikan pengaruh yang signifikan dalam mendekomposisi bahan organik., The accumulation of organic matter in aquaculture pond can cause the oxygen deficit and can cause the shrimps are under physiological stress, therefore it can be susceptible by germs. This study aims to determine the effectiveness of bacteria Thiobacillus spp. to decompose organic matter in seawater media as a pond water simulation. This study used complete randomized design (CRD) in time with 4 treatments, namely without the addition of probiotic (control), addition of probiotic in the technical media of molasses as much as 5 ppm (P1), addition of probiotic in the technical media of molasses as much as 10 ppm (P2), and addition of probiotic in the technical media of molasses as much as 15 ppm (P3). Each treatment was repeated three times. Parameters that observed such as water quality and total bacteria. The most significant decrease of BOD5 reaching 53,4% was in P3, which was 86.4 ± 19.2 mg/L, while the most significant decrease of TOM was in P1, which was 33.7 ± 2.9 mg/L. Bacteria Thiobacillus spp. has been shown a significant effect to decompose of organic matter effectively.
Keyword: Accumulation, BOD, organic matter, TOM

Judul: The Effects of Thiobacillus sp. Probiotics Application to  Water Quality of Shrimp Pond Wastewater
Abstrak: Senyawa beracun seperti H2S, amonia, nitrit, dan nitrat di tambak dapat berasal dari perombakan bahan organik yang tertimbun di sedimen. Usaha yang dilakukan untuk menciptakan kualitas air yang baik, salah satunya adalah dengan aplikasi bakteri probiotik. Penelitian ini bertujuan untuk menganalisis pengaruh penerapan bakteri probiotik Thiobacillus sp. terhadap kualitas air pada limbah tambak. Penelitian ini menggunakan rancangan RAL in time dengan empat perlakuan. Perlakuan yang diberikan yaitu penambahan konsorsium Thiobacillus sp. dengan dosis 0 ppm (kontrol), 0,1 ppm, 0,2 ppm, dan 0,4 ppm. Parameter yang diamati yaitu suhu, pH, DO, amonia, nitrit, nitrat, H2S, serta penghitungan kelimpahan total bakteri. Hasil menunjukkan bahwa penambahan probiotik yang mengandung Thiobacillus dapat meningkatkan kelimpahan total bakteri pada air limbah. Penambahan probiotik memberi pengaruh terhadap penurunan konsentrasi nitrit dan nitrat pada beberapa perlakuan. Namun, penambahan probiotik tidak berpengaruh pada penurunan konsentrasi H2S dan TAN., Toxic compounds such as H2S, ammonia, nitrite, and nitrate in ponds can come from the breakdown of organic matter in ponds sediments. Good ponds water quality could be created by the application of probiotic bacteria. This study aims to analyze the effect of Thiobacillus sp. probiotic application on water quality of pond wastewater. This study used the RAL design in time with four treatments. The treatment given was the addition of a consortium of Thiobacillus sp. with doses of 0 ppm (control), 0.1 ppm, 0.2 ppm, and 0.4 ppm. The parameters observed were temperature, pH, DO, ammonia, nitrite, nitrate, H2S, and the abundance of total bacteria. The results showed that the addition of probiotics containing Thiobacillus could increase the total bacteria in wastewater. The addition of probiotics had an effect on decreasing of nitrite and nitrate concentration in several treatments. However, the addition of probiotics had no effect on decreasing of H2S and TAN concentration.
Keyword: probiotic, Thiobacillus, wastewater, water quality

Judul: Konstruksi Hukum Grup Kurva Eliptik Atas F3m
Abstrak: Elliptic curves upon F3m can be divided in two cases, i.e. supersingular and nonsupersingular case. Based on group laws on elliptic curves, a new arithmetic upon F3m can be formulated as an addition process of two random points on the curve. This addition process can then be applied to the ElGamal algorithm.
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