Judul: Daya Tampung Beban Nitrogen di Waduk Jatigede, Jawa Barat
Abstrak: Waduk Jatigede terletak dekat dengan daerah pemukiman dan kegiatan pertanian, sehingga berpotensi menerima buangan limbah. Limbah tersebut dapat mengandung bahan pencemar seperti nitrogen. Peningkatan kadar nitrogen yang tidak terkontrol dalam perairan dapat memberikan dampak buruk, seperti menurunnya kualitas air dan memicu terjadinya eutrofikasi. Penelitian ini bertujuan menganalisis daya tampung beban nitrogen di Waduk Jatigede, Jawa Barat. Pengambilan contoh air dilakukan pada bulan Februari hingga April 2021 di perairan Waduk Jatigede pada enam stasiun pengamatan dan dua sungai utama inlet Waduk Jatigede. Analisis data yang digunakan meliputi penentuan beban nitrogen dari sungai (inlet), pendugaan beban nitrogen dalam waduk, sedimentasi nitrogen, daya tampung beban nitrogen, dan uji perbedaan konsentrasi nitrogen total pada lapisan epilimnion dan hipolimnion. Beban nitrogen di Waduk Jatigede selama pengamatan adalah 24.374 ton. Hal ini menunjukkan bahwa beban nitrogen tersebut telah melebihi batas maksimum menurut baku mutu perairan sebesar 1.739 ton. Kesimpulan dari penelitian ini adalah Waduk Jatigede sudah tidak mampu lagi menampung beban nitrogen yang masuk ke dalam waduk. Namun, daya tampung beban nitrogen masih dapat diestimasi berdasarkan nilai baku mutu perairan. Daya tampung beban nitrogen maksimal sesuai dengan baku mutu perairan di Waduk Jatigede adalah 595 ton/tahun., Jatigede Reservoir is situated close to residential areas and agricultural activities, making Jatigede Reservoir has the potential to receive waste disposal. The waste may contain pollutants, one of which is nitrogen. Uncontrolled increases in nitrogen levels can cause negative impacts, such as water quality deterioration which may lead to eutrophication. The purpose of this study is to analyze the nitrogen load capacity in Jatigede Reservoir, West Java. Water samples were taken from February to April 2021 at six sampling points in the reservoir and two locations in the main inlet rivers. Data analysis consisted of nitrogen load from the river (inlet), nitrogen load in the reservoir, nitrogen sedimentation, nitrogen load capacity, and the test of difference in total nitrogen concentration at the epilimnion and hypolimnion layers. The nitrogen load in Jatigede Reservoir during the observation was 24,374 tons. It shows that the nitrogen load has exceeded the maximum limit according to the water quality standard, which is 1,739 tons. In conclusion, Jatigede Reservoir is no longer able to accommodate the nitrogen load to enter the reservoir. However, the nitrogen load capacity can still be estimated based on water quality standards. Based on water quality standards, the maximum nitrogen load capacity of Jatigede Reservoir was 595 tons N per year.
Keyword: nitrogen load, nitrogen load capacity, Jatigede Reservoir

Judul: Daya Tampung Beban Fosfor di Perairan Waduk Jatigede, Kabupaten Sumedang, Jawa Barat
Abstrak: Kegiatan pertanian dan pemukiman yang berada di sekitar waduk dapat menjadi sumber masukan fosfor, sehingga akan memengaruhi kualitas air waduk. Penelitian ini bertujuan menghitung daya tampung beban nutrien fosfor (P) berdasarkan lapisan kedalaman di perairan Waduk Jatigede. Pengambilan contoh air dilakukan setiap bulan dari bulan Februari hingga April 2021 pada inlet Waduk Jatigede dan perairan Waduk Jatigede. Seluruh stasiun pengamatan di perairan waduk terbagi menjadi lapisan epilimnion dan hipolimnion. Konsentrasi fosfor (total dan terlarut) tertinggi pada zona riverin di lapisan epilimnion. Terdapat 11 sungai yang masuk ke Waduk Jatigede, namun masukan beban fosfor yang utama adalah dari Sungai Cimanuk dan Sungai Cinambo. Daya tampung beban fosfor berdasarkan lapisan kedalaman di perairan Waduk Jatigede adalah 3285 kg tahun-1 untuk lapisan epilimnion dan 1593 kg tahun-1 untuk lapisan hipolimnion. Daya tampung beban fosfor untuk seluruh volume waduk adalah 4878 kg tahun-1., Agricultural and residential activities around the reservoir can be a source of phosphorus input, which will affect the water quality of the reservoir. This study aims to calculate the load capacity of phosphorus (P) based on the stratification of water in Jatigede Reservoir. Water samples were taken every month from February to April 2021 at rivers inlet and Jatigede Reservoir. All observation stations in the reservoir are divided into epilimnion and hypolimnion layers. The concentration of phosphorus (total and dissolved) were highest in the riverine zone at the epilimnion layer. There are 11 rivers that enter the Jatigede Reservoir, but the main phosphorus load input is from the Cimanuk River and Cinambo River. The load capacity of phosphorus in the Jatigede Reservoir are about 3285 kg year-1 for epilimnion layer and 1593 kg year-1 for hypolimnion layer. The load capacity of phosphorus for the entire volume of the reservoir is about 4878 kg year-1.
Keyword: Beban Fosfor, Lapisan Perairan, Waduk Jatigede

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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