Judul: The effect of waste on chlorophyll content of leaves and regeneration of mangrove forest at angke kapuk protection forest, north jakarta2
Abstrak: Ekosistem mangrove merupakan peralihan antara daratan dan lautan. Saat ini hutan mangrove di kawasan lindung Angke Kapuk, Jakarta Utara terdegradasi diantaranya karena tumpukan sampah yang masuk ke kawasan hutan tersebut. Sehubungan dengan itu, penelitian ini dilaksanakan dengan tujuan untuk mengkaji sejauh mana pengaruh keberadaan sampah terhadap kandungan klorofil daun pohon mangrove dan regenerasi hutan mangrove di kawasan lindung Angke Kapuk. Hasil penelitian menunjukkan bahwa keberadaan sampah tidak berpengaruh terhadap kandungan klorofil daun pohon mangrove, tetapi berpengaruh terhadap regenerasi hutan mangrove. Hal ini ditunjukkan dengan kerapatan anakan pohon (semai) pada kawasan hutan tidak ada sampah lebih besar dibandingkan kerapatan anakan mangrove di kawasan sedikit sampah dan kawasan banyak sampah., Mangrove ecosystem is a transition ecosystem between land and sea. Currently the mangrove forests at Angke Kapuk Protection Forest, North Jakarta has been degraded by large amount waste. In connection with this situation, the forest research was carried out with the aim to consider the effect of waste existence on the chlorophyll content of tree’s leaf and the regeneration of mangrove forests in Angke Kapuk Protection Forest. The results showed that the existence of the waste has no effect on the chlorophyll content of leaves, but it has significant by effect on the regeneration of mangrove forest. This is shown with a density of mangrove seedlings in the less waste-occupied mangrove area is bigger than that of medium and high waste-occupied mangrove areas.
Keyword: ekosistem mangrove, kandungan klorofil daun, regenerasi hutan, sampah

Judul: Analysis of Mangrove Damage and Rehabilitation Steps in the Angke Kapuk Protected Forest, North Jakarta
Abstrak: Ekosistem mangrove merupakan salah satu habitat alami pada kawasan pesisir yang sangat rentan terhadap ancaman alam baik dari darat maupun laut. Selain disebabkan oleh alam, ancaman terhadap ekosistem mangrove juga dapat disebabkan oleh kegiatan manusia. Penelitian ini bertujuan untuk menganalisis tingkat kerusakan mangrove dan potensi rehabilitasi mangrove di Hutan Lindung Angke Kapuk, Jakarta Utara. Penelitian ini dilaksanakan pada bulan Desember 2021 hingga Januari 2022 dengan lokasi penelitian terdiri dari tiga stasiun yang meliputi tiga tipe yaitu teluk, muara sungai, dan pantai reklamasi. Kerapatan dan penutupan mangrove di Angke Kapuk tergolong dalam kriteria rendah, kecuali stasiun 1 yang memiliki kerapatan sangat tinggi dan penutupan mangrove dalam kriteria rendah. Kondisi ini mengakibatkan nilai indeks kesehatan mangrove menjadi sedang pada stasiun 1, sedangkan stasiun 2 dan 3 tergolong kategori rendah. Indeks kualitas lingkungan pada ketiga stasiun tergolong kedalam kategori tinggi. Berdasarkan nilai kedua indeks tersebut, tingkat kerusakan pertumbuhan mangrove tergolong tinggi dan kerusakan lingkungan mangrove tergolong rendah dan diketahui matriks rehabilitasi mangrove dengan strategi replantasi. Strategi replantasi tersebut mempertimbangkan zonasi dalam penentuan jenis mangrove yang ditanam., Mangrove , one of the natural ecosystems in coastal areas is very vulnerable to n threats both from land and sea. Besides being caused by nature, threats to mangrove ecosystems can also be caused by human activities. This study aims to analyze the level of damage to mangroves and the potential for mangrove rehabilitation in the Angke Kapuk Protection Forest, North Jakarta. This research was carried out from December 2021 to January 2022 with research locations consisted of three stations covering three types, namely bays, river mouths, and reclamation beaches. The density and cover of mangroves in Angke Kapuk are classified as low criteria, except for station 1 which has a very high density and mangrove cover is in the low criteria. This condition causes the mangrove health index value to be moderate at station 1, while stations 2 and 3 are in the low category. The environmental quality index at the three stations belongs to the high category. Based on the values of these two indices, the level of damage to mangrove growth is classified as high and environmental damage to mangroves is classified as low and it is known that the mangrove rehabilitation matrix with a replantation strategy. The replantation strategy considers zoning in determining the type of mangrove to be planted
Keyword: kesehatan mangrove, kualitas lingkungan, mangrove, rehabilitasi, environmental quality, mangrove health, rehabilitation, mangroves

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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