Judul: Effect of Composition of Compost, Fly ash, and  Mineral Fertilizer on N Availability of Pineapple (Ananas comosus L. Merr)  Growth
Abstrak: Nitrogen merupakan unsur hara esensial bagi pertumbuhan tanaman. Kehilangan nitrogen dalam tanah disebabkan oleh adanya pencucian, penguapan, dan yang terserap oleh tanaman. Penelitian ini bertujuan mengidentifikasi pengaruh persentase kompos dan fly ash terhadap ketersediaan hara N pada pertumbuhan tanaman nanas, serta mengidentifikasi perbaikan pertumbuhan tanaman nanas dan sistem perakarannya akibat aplikasi SRF dibandingkan dengan pupuk standar baku PT. GGP. Penelitian dilaksanakan di Kebun Reasearch and Development PT Great Giant Pineapple, Kabupaten Lampung Tengah pada bulan Oktober 2021 – Januari 2022. Tanaman yang diamati merupakan tanaman nanas klon GP3. Penelitian ini menggunakan 3 komposisi kompos dan fly ash dalam pupuk mineral yaitu tanpa pemberian kompos dan fly ash, 40% kompos dan 20% fly ash, serta 20% kompos dan 40% fly ash masing-masing 4 ulangan. Hasil penelitian menunjukkan persentase kompos dan fly ash tidak berbeda nyata terhadap ketersediaan N dalam tanah, N tercuci, dan N menguap, serta pertumbuhan daun dan akar., Nitrogen is an essential nutrient for plant growth. Loss of nitrogen in the soil is caused by leaching, evaporation, and being absorbed by plants. This study aims to identify the effect of the percentage of compost and fly ash on the availability of N-nutrients on the growth of pineapple plants, as well as identify the improvement of pineapple plant growth and root system due to SRF application compared to standard standard fertilizers of PT. GGP. The research was carried out at the Research and Development Garden of PT Great Giant Pineapple, Central Lampung Regency in October 2021 – January 2022. The plant to be monitored is a GP3 clone of pineapple. This study uses 3 compositions of compost and fly ash in mineral fertilizers, namely without compost and fly ash, 40% compost and 20% fly ash, as well as 20% compost and 40% fly ash with 4 replications each. The results showed that the percentages of compost and fly ash were not significantly different to the availability of N in the soil, leached N, evaporated N, and root and leaf growth.
Keyword: plant vegetative, slow release fertilizers, waste coal

Judul: Pengaruh Penambahan FABA dan Lignit dalam Kompos terhadap Sifat Kimia dan Pertumbuhan Nanas (Ananas comosus) pada Ultisol
Abstrak: Degradasi pada Ultisol disebabkan oleh kegiatan monokultur secara terus-menerus dicirikan dengan pH, kadar bahan organik, dan unsur hara rendah, serta kadar aluminium yang tinggi. Untuk mengatasi degradasi Ultisol demikian, digunakan amelioran berupa kompos. Namun, penggunaan kompos sebagai amelioran belum mendapatkan hasil yang optimal terhadap peningkatan kualitas Ultisol. Kompos kurang dalam menyediakan unsur hara, sehingga diperlukan penambahan fly ash dan bottom ash (FABA) maupun lignit dalam kompos. Tujuan dari penelitian ini adalah untuk mengetahui pengaruh penambahan FABA dan lignit dalam kompos untuk memperbaiki kualitas Ultisol yang ditanami nanas, serta mengetahui pengaruh penambahan FABA dan lignit dalam kompos terhadap pertumbuhan serta kadar hara dalam daun nanas. Perlakuan dalam penelitian ini disusun menggunakan rancangan petak terbagi dalam rancangan acak kelompok dengan petak utama adalah teknik aplikasi palir (P) dan tebar (T) serta anak petak adalah kompos 100% (K), kompos 75%+FABA 25% (KF), dan kompos 70%+FABA 20%+ lignit 10% (KFL). Perbandingan fly ash dan bottom ash adalah 6:1, serta bottom ash dan lignit telah lolos ayakan 1 cm. Amelioran diberikan dengan dosis 50 ton ha-1. Tanaman uji yang digunakan adalah bibit nanas klon GP3 sucker kelas besar dan dilaksanakan di blok 86-A kebun PT. Great Giant Pineapple. Hasil penelitian ini menunjukkan bahwa penambahan FABA dan lignit dalam kompos meningkatkan pH, karbon organik, kejenuhan basa, kalsium-, magnesium-, natrium-dapat dipertukarkan, dan seng serta menurunkan kadar aluminium dapat dipertukarkan pada Ultisol. Penambahan FABA dan lignit dalam kompos juga meningkatkan kadar kalsium, belerang, dan seng dalam daun. Disamping itu, penambahan FABA dalam kompos meningkatkan D-leaf index tanaman nanas. Pemberian amelioran lebih efektif jika diaplikasikan secara palir dibandingkan dengan tebar. Penggunaan FABA dalam kompos sebagai amelioran diharapkan dapat meningkatkan kualitas Ultisol terdegradasi dan produktivitas tanaman serta mengurangi dosis kompos yang digunakan pada tanaman nanas., Degradation of Ultisol is caused by continuous monoculture activities and is characterized by low pH, organic matter, nutrient content, and high aluminium contents. In response to such Ultisol degradation, ameliorants in the form of compost are used. However, using compost as an ameliorant has yet to obtain optimal results toward improving the Ultisol quality. The lack of ability of compost to supply nutrients is because the nutrients in compost are easily lost due to leaching, so it is necessary to add coal ash consisting of fly ash and bottom ash (FABA) also lignite in compost. This study aimed to determine the effect of compost-enriched with FABA and Lignite to improve the Ultisol's quality planted with pineapple and also on its growth and nutrient levels in the leaves. The treatments in this study were arranged using a split plots design in a randomized block design, with the main plot being the application technique of row (P) and spread (T). The subplots were 100% compost (K), 75% compost + 25% FABA (KF), and 70% compost + 20% FABA + 10% lignite (KFL). The ratio of fly ash and bottom ash was 6:1, and bottom ash and lignite had passed a 1 cm sieve. Ameliorants were applied at a dose of 50 tons ha-1. The test plants used were pineapple seedlings of large class clones GP-3 sucker and were carried
Keyword: Compost, Faba, Lignite, Pineapple, Ultisol

Judul: Hamiltonian formulation for linear waves motion in two layers fluid
Abstrak: The surface wave could be considered as a wave that separates two fluids, namely water and air. Based on this assumption, it is introduced the interfacial wave, a wave between two layers of fluid with different density. The formulation of interfacial waves motion begins with deriving the base equation of irrotational ideal fluid. Furthermore, according to irrotational fluid assumption, the base equation can be stated in velocity potential. In this derivation, the fluids domain is assumed to be restricted by rigid lid boundary conditions, both at the upper and lower limit. Therefore, the interfacial waves motion can be explained in a hamiltonian formulation. In the hamiltonian formulation, total energy is defined as the sum of kinetic and potential energy. The hamiltonian system is obtained from reduction of kinetic energy by using the Dirichlet Neumann Operator. The resulted kinetic energy equation is nonlinear. Therefore, this form is linearized by first part of the Taylor expansion. This linearization gives a dispersion relation of linear wave. Based on this dispersion relation, the phase speed of the linear wave depends on the density ratio of the two layers fluid.
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