Judul: Productivity of Earthworms (Pheretima sp.) with the Addition of Green Shell Flour as Maintenance Media
Abstrak: Cacing tanah memiliki banyak kemampuan, antara lain: mendekomposisi material organik, dan mengaduk material organik dan anorganik. Faktor lingkungan yang mempengaruhi kehidupan cacing tanah antara lain suhu, pH, kelembaban, tekstur, dan kandungan nutrien. Peningkatan jumlah timbunan dan masih minimnya pemanfaatan limbah cangkang kerang. Penelitian ini bertujuan untuk menganalisis produktivitas cacing tanah Pheretima sp. dengan memanfaatkan limbah cangkang kerang hijau. Penelitian ini menggunakan metode eksperimen dengan Rancangan Acak Lengkap (RAL) dengan 4 (empat) perlakuan dan 3 (tiga) ulangan dan analisis uji lanjut Tukey. Hasil penelitian menunjukkan adanya pengaruh nyata (P<0,05) pada penggunaan feses sapi sebanyak 90% dengan penambahan tepung cangkang kerang hijau 10% lebih baik dari perlakuan lain karena terbukti dapat meningkatkan bobot cacing tanah (Pheretima sp.) sebanyak 33,3 gram dan meningkatkan jumlah konsumsi media sebanyak 262,67 gram. Penambahan tepung cangkang kerang hijau dapat meningkatkan produktivitas cacing tanah pada taraf penggunaan kurang dari atau sama dengan 10%., Earthworms have many abilities, including: decomposing organic matter, and mixing organic and inorganic materials. Environmental factors that affect the life of earthworms include temperature, pH, humidity, texture, and nutrient content. Increasing the number of piles and still minimal utilization of shell waste. This study aims to analyze the productivity of the earthworm Pheretima sp. by utilizing waste green mussel shells. This study used an experimental method with a completely randomized design (CRD) with 4 (four) treatments and 3 (three) replications and Tukey's follow-up test analysis. The results showed that there was a significant effect (P<0.05) on the use of cow feces as much as 90% with the addition of 10% green mussel shell flour which was better than other treatments because it was proven to increase the weight of earthworms (Pheretima sp.) by 33.3 grams and increased the amount of media consumption by 262.67 grams. The addition of green mussel shell flour can increase the productivity of earthworms at a usage level of less than or equal to 10%.
Keyword: green mussel, Pheretima sp., productivity, shell waste

Judul: Productivity Performance of Earthworm (Lumbricus rubellus) on Cow Manure Media with the Addition of Cricket Manure
Abstrak: Cacing tanah sebagai salah satu fauna yang digunakan dalam indikator untuk mengukur kualitas dan kesuburan suatu tanah. Dalam pemeliharaan cacing tanah terdapat beberapa faktor yang mempengaruhi kehidupan cacing yaitu suhu, pH, kelembapan, kandungan nutrien dan tekstur media. Tujuan penelitian ini menganalisis produktivitas cacing tanah (Lumbricus rubellus) dalam media campuran kotoran sapi dan kotoran jangkrik. Penelitian ini menggunakan metode Rancangan Acak Lengkap (RAL) dengan 6 perlakuan dan 3 ulangan dengan uji lanjut tukey. Hasil penelitian menunjukkan penggunaan kotoran sapi sebanyak 90% dengan penambahan kotoran jangkrik 10% dengan pertambahan bobot rata-rata sebesar 17 gram, jumlah kokon rata-rata 94 butir, dan penyusutan media rata-rata 260,50 gram. Penggunaan kotoran sapi dengan penambahan kotoran jangkrik melebihi 10% dapat menurunkan produktivitas cacing tanah., Earthworms are among the fauna used as indicators of the quality and fertility of soil. In the maintenance of earthworms, there are several factors that influence their life, namely temperature, pH, humidity, nutrient content, and media texture. The study aims to analyze the productivity of earthworms (Lumbricus rubellus) in a mixture of cow dung and cricket dung. This study used a Completely Randomized Design (CRD) method with 6 treatments and 3 replications with Tukey's advanced test. The results showed that the use of cow dung was 90% with the addition of 10% cricket dung with an average weight increase of 17 grams, an average number of cocoons of 94, and an average media shrinkage of 260.50 grams. Using cow manure with the addition of cricket manure exceeding 10% can reduce earthworm productivity. The use of cow dung with the addition of cricket dung exceeding 10% can decrease the productivity of earthworms.
Keyword: cricket manure, cattle manure, Lumbricus rubellus, produktivity

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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