Judul: Condition of Waters in Pejarakan Mangrove Ecosystem, Buleleng, Bali Based on Water Quality Status
Abstrak: Kawasan ekosistem mangrove Pejarakan, Bali merupakan salah satu perairan yang memiliki hutan mangrove terluas di Kabupaten Buleleng dan dikelola untuk konservasi serta edukasi. Masukkan limbah antropogenik ataupun pertambakkan dari sekitar wilayah tersebut dapat mempengaruhi perubahan kualitas air. Penelitian ini bertujuan untuk mengevaluasi kondisi perairan yang mencakup beberapa parameter fisika dan kimia sebagai dasar penentuan status kualitas air di wilayah tersebut. Penelitian dilakukan di kawasan mangrove Pejarakan, Bali pada 6 titik stasiun sejak September 2022, Januari 2023, September 2023, dan Januari 2024. Metode analisis yang digunakan meliputi indeks pencemaran (IP), CCME-WQI, dan STORET. Berdasarkan hasil pengamatan, suhu (28,7-37,4°C), pH (7,47-8,49), DO (3-7,6 mg/L), kekeruhan (0,17-18,75 mg/L), TSS (2,8-38,6 mg/L), nitrat (0,02-0,05 mg/L), amonia (0,05-0,5 mg/L), total fosfat (0,01-0,75 mg/L) yang diperoleh umumnya perairan berstatus tercemar ringan untuk metode indeks pencemaran (IP) dan STORET, serta kondisi cukup baik untuk metode CCME-WQI., Pejarakan mangrove ecosystem area, Bali is one of the largest mangrove forests in Buleleng Regency and is managed for conservation and education. The input of anthropogenic waste or aquaculture from around the area can affect changes in water quality. This study aims to evaluate water conditions that include several physical and chemical parameters as a basis for determining the status of water quality in the region. The research was conducted in Pejarakan mangrove area, Bali at 6 station points since September 2022, January 2023, September 2023, and January 2024. The analysis methods used include pollution index (IP), CCME-WQI, and STORET. Based on the observation results, temperature (28.7-37.4°C), pH (7.47-8.49), DO (3-7.6 mg/L), turbidity (0.17-18.75 mg/L), TSS (2.8-38.6 mg/L), nitrate (0.02-0.05 mg/L), ammonia (0.05-0.5 mg/L), total phosphate (0.01-0.75 mg/L) obtained generally waters are mildly polluted for the pollution index (IP) and STORET methods, and fair condition for the CCME-WQI method.
Keyword: CCME-WQI, Pejarakan, Pollution Index, STORET, Water Quality.

Judul: Water Pollution Index in Banten Bay Waters Based on Several Water Physical Parameters
Abstrak: Aktivitas antropogenik di sekitar kawasan perairan Teluk Banten dapat membawa limbah tercemar ke dalam perairan. Sehingga dapat memengaruhi kualitas perairan. Penelitian status mutu suatu perairan penting dilakukan untuk menduga kondisi pencemaran suatu perairan. Penelitian ini bertujuan menentukan tingkat pencemaran perairan Teluk Banten melalui pendekatan beberapa parameter fisika perairan. Data yang digunakan ialah data primer dan sekunder tahun 2019- 2022 dari enam lokasi penelitian. Parameter yang dianalisis antara lain suhu, kecerahan, kekeruhan, dan padatan tersuspensi (TSS). Hasil analisis yang diperoleh dibandingkan dengan baku mutu berdasarkan PP No 22 Tahun 2021. Berdasarkan hasil pengamatan suhu (25.1-39ᵒC), kecerahan (0.05-10 m), kekeruhan (0.24-380 NTU), TSS (0.4-742 mg/l), menunjukan bahwa sebagian parameter masih tergolong dibawah baku mutu beberapa parameter kurang sesuai dengan baku mutu perairan (antara lain suhu, kecerahan, kekeruhan, TSS). Berdasarkan hasil perhitungan indeks pencemaran perairan Teluk Banten memiliki indeks pencemaran kategori tercemar ringan (1.315-4.490)., Anthropogenic activities around the waters of Banten Bay can bring polluted waste into the waters. So that it can affect water quality. Research on the quality status of a waters is important to do to predict the pollution conditions of a waters. This study aims to determine the pollution level of Banten Bay waters through the approach of several water physics parameters. The data used are primary and secondary data for 2019-2022 from six research locations. Parameters analyzed included temperature, brightness, turbidity, and suspended solids (TSS). The results of the analysis obtained were compared with the quality standards based on PP No. 22 of 2021. Based on the results of observations of temperature (25.1-39ᵒC), brightness (0.05-10 m), turbidity (0.24-380 NTU), TSS (0.4-742 mg/l) , shows that some of the parameters are still below the quality standards, some parameters are not in accordance with the water quality standards (among others temperature, brightness, turbidity, TSS). Based on the results of the calculation of the water pollution index, Banten Bay has a pollution index of the lightly polluted category (1.315-4.490).
Keyword: baku mutu, indeks pencemaran, kualitas air, parameter fisika, teluk banten

Judul: Construction of Strongly Optimal Binary Linear Code with Minimum Distance 9 and 11
Abstrak: A binary linear code of length n over q F is a subspace of n q F . A code has three parameters that attached to it, namely length, dimension, and minimum distance. A code with length n, dimension k and minimum distance d is often called [n, k, d ]-code. Usually, when two parameters are given, then we want to find a code that has the best value for the last parameter. Based on Gilbert- Varshamov bound, if a [n, k, d ]-code exists and can not be expanded, we call it a strongly optimal code. In this paper, we construct strongly optimal code with minimum distance 9 and 11. In constructing the code, we created a theorem and algorithm based on Gilbert-Varshamov bound before we implement the algorithm to MAPLE programming language. Because of computational limitations, the program can only construct up to k = 10 for d = 9 and k = 12 for d = 11.
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