Judul: Respon Kerang Hijau (Perna viridis) Terhadap Mikroplastik dan Mikro Partikel Alami
Abstrak: Penelitian mengenai dampak mikroplastik bagi hewan laut sudah banyak dilaporkan, namun hampir semua penelitian tersebut tidak membandingkan dampak yang diberikan mikroplastik dengan mikro partikel alami yang ada di alam yang juga dapat menjadi stressor bagi hewan laut. Hal ini dapat menyebabkan kesalahan interpretasi atas dampak yang diberikan mikroplastik kepada hewan. Maka kami melakukan penelitian ini untuk melihat apakah dampak yang diberikan mikroplastik dan mikro partikel alami benar-benar berbeda terhadap kerang hijau. Penelitian ini dilakukan di laboratorium selama 21 hari. Kerang hijau diberi paparan mikroplastik PVC dan mikro partikel alami red clay dengan tingkat konsentrasi yang berbeda (1.5 mg / l, 15 mg / l and 150 mg / l). Variabel yang diamati yaitu survival rates, clearance rates, and BCI index. Hasilnya untuk clearance rates dan survival rates secara statistik tidak berbeda nyata, sementara hasil BCI memperlihatkan dampak dari paparan PVC dan red clay pada tiap konstentarsi kurang dari 10%. Hal ini menunjukkan bahwa dampak dari paparan PVC dan red clay masih serupa. Sehingga sangat penting bagi penelitian mikroplastik selanjutnya untuk memasukkan pembanding mikro partikel alami sebagai indikator tingkat stress bagi hewan yang diamati., The impact of microplastics on marine animals has been widely reported, but almost all of them do not compare the effect of microplastics with natural micro particles, which can also be a stressor for the animals. This can lead us to look overestimated effect of microplastics on marine animals. Here we conducted a study to see whether the effect of microplastics was the same as the effect of natural micro particles on green mussels (Perna viridis). This research was conducted experimentally in the laboratory for 21 days. Green mussels were exposed to PVC as microplastics and red clay as natural micro particles with three different concentrations (1.5 mg/l, 15 mg/l, and 150 mg/l). We observed survival rates, clearance rates, and BCI index. Clearance rates and survival rates were not statistically significant, while the BCI results showed that the effects of PVC and red clay at each concentration were less than 10%. This suggests that the effect of microplastics and natural micro particles is similar, and it is necessary to include natural micro particles as a comparison in research related to microplastics.
Keyword: microplastics, natural micro particles, green mussel, survival rates, clearance rates, body condition index

Judul: Identifikasi Kelimpahan Mikroplastik pada Kerang Hijau (Perna viridis) dan Hubungannya dengan Panjang Kerang
Abstrak: Mikroplastik merupakan bahan plastik atau fragment yang berukuran lebih kecil dari 5 mm. Ukuran mikroplastik yang sangat kecil memungkinkan partikel ini masuk kedalam tubuh biota laut seperti ikan dan bivalvia, akibatnya polutan ini dapat masuk ke sistem rantai makanan (aquatic food chain). Tujuan penelitian ini adalah mengetahui kelimpahan dan bentuk-bentuk mikroplastik yang terdapat pada kerang hijau (Perna viridis) serta mengetahui hubungan panjang kerang dengan jumlah mikroplastik yang ada pada kerang. Daging P. viridis yang telah dipisahkan dari cangkangnya dilarutkan dalam larutan H2O2 30% dan dilakukan pengapungan dengan menggunakan larutan garam. Hasil fitrasi sampel kemudian di observasi menggunakan mikroskop stereo. Jenis mikroplastik yang ditemukan yaitu fiber, fragmentt dan film. Berdasarkan warnanya, mikroplastik diidentifikasi menjadi warna biru, merah, hijau dan transpasran. Kelimpahan mikroplastik tertinggi berdasarkan berat basahnya terdapat pada kerang dengan ukuran < 3 cm., Microplastics are plastic material or fragments smaller than 5 mm in size. The very small size of microplastics allows these particles to enter the bodies of marine life such as fish and bivalves, as a result, these pollutants can enter the aquatic food chain system. The purpose of this study was to determine the abundance and forms of microplastics found in green mussel (Perna viridis) and determine the relation between the length of the mussel and the number of microplastics on green mussel (P. viridis). The meat that has been separated from the shell is dissolved in 30% H2O2 solution and flotation is carried out using a salt solution. The results of the sample fitration were then observed using a stereo microscope. The types of microplastics found are fiber, fragment and film. Based on their color, microplastics are identified as a blue, red, green and transparent. The highest abundance of microplastics based on wet weight was found in mussel with size smaller than 3 cm.
Keyword: shape, abundance, green mussel, microplastics, colour

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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