Judul: Productivity of Earthworms Type Lumbricus rubellus with Mustard Green Waste and Papaya Waste
Abstrak: Budidaya cacing dapat mengatasi masalah pencemaran lingkungan melalui pemanfaatan limbah pasar sebagai pakan cacing tanah. Sampah pasar yang banyak dijumpai adalah sampah sayur dan sampah buah. Pakan dari limbah pasar dapat menekan biaya produksi dalam budidaya cacing tanah. Penelitian ini bertujuan untuk mengkaji pengaruh pemberian pakan dari limbah sayur sawi dan buah pepaya terhadap produktivitas cacing tanah Lumbricus rubellus, produksi vermikompos, serta nilai ekonomi budidaya. Penelitian ini mengunakan eksperimen dengan rancangan acak lengkap, empat perlakuan dan tiga ulangan. Hasil penelitian menunjukkan bahwa perlakuan berpengaruh nyata (P<0,05) terhadap bobot badan cacing, panjang badan cacing, dan produksi vermikompos. Bobot badan cacing tanah tertinggi pada perlakuan pakan dengan limbah pepaya (P400) sebesar 1,108 ± 0,128 g, panjang badan cacing tertinggi pada perlakuan P400 (9,367 ± 0,446 cm), dan produksi vermikompos yang menghasilkan degradasi limbah tertinggi pada perlakuan P400 (45,62%). Pemanfaatan limbah pepaya memberikan hasil yang terbaik terhadap pertambahan bobot badan dan panjang badan L. rubellus. Budidaya cacing tanah dapat memberikan nilai ekonomis dengan menghasilkan cacing tanah dan vermikompos., Worm cultivation can overcome environmental pollution problems through the use of market waste as feed for earthworms. Market waste that is often found is vegetable waste and fruit waste. Feed from market waste can reduce production costs in earthworm cultivation. This research was an experiment with completely randomized design, four treatments and three replications. The research aims to investigative the effect of feed with mustard green waste and papaya waste on the productivity of L. rubellus earthworms, vermicompost production, and economic value of cultivation. The results showed that the treatment had a significant (P<0,05) effect on body weight, body length, and vermicompost production. The highest body weight of the earthworm was in treatment with papaya waste (P400) of 1,108 ± 0,128 g, the highest body length of earthworm was in treatment P400 (9,367 ± 0,446 cm), and vermicompost production which resulted in highest waste degradation in treatment P400 (45,62%). The use of papaya waste gives the best result on body weight gain and body length of L. rubellus. Earthworm cultivation can provide economic value by producing earthworms and vermicompost.
Keyword: cow dung, Lumbricus rubellus, mustard green waste, papaya waste

Judul: Productivity of Earthworms (Lumbricus rubellus) in Mixed Media of Cow Manure and Chicken Manure with Different Levels
Abstrak: Cacing tanah atau jenis Lumbricus rubellus tergolong dalam kelompok avertebrata atau tidak bertulang belakang yang memiliki potensi dan banyak manfaat serta mudah dibudidayaka dengan menggunakan media kotoran ternak. Tujuan penelitian ini menganalisis produktivitas cacing tanah (Lumbricus rubellus) dalam media campuran kotoran sapi dan kotoran ayam dengan taraf yang berbeda. Penelitian ini menggunakan Rancangan Acak Lengkap (RAL) dengan 6 perlakuan dan 3 ulangan dengan uji lanjut Duncan. Media yang digunakan kotoran sapi dengan penambahan kotoran ayam IPB-D1 dengan taraf berbeda. Hasil penelitian menunjukkan penggunaan kotoran sapi dengan penambahan kotoran ayam IPB-D1 berpengaruh nyata (P<0,05) terhadap produktivitas cacing tanah. Penggunaan kotoran sapi sebanyak 95% dengan penambahan kotoran ayam sebanyak 5% berpengaruh nyata dan dapat meningkatkan jumlah populasi cacing tanah (Lumbricus rubellus) sebanyak 285,67 g dan penyusutan media sebesar 164,17 g. Penggunaan kotoran sapi sebanyak 85% dengan penambahan kotoran ayam sebanyak 15% dapat meningkatkan bobot cacing tanah sebesar 17,09 g dan produksi kokon sebanyak 155,58 butir. Pencampuran kotoran ayam pada kotoran sapi sebanyak ≤15% baik untuk produktivitas cacing Lumbricus rubellus, sebaliknya >15% menurunkan produktivitas cacing tanah., Earthworms or type Lumbricus rubellus belong to the group of invertebrates or not vertebrates that have the potential and many benefits and are easily cultivated using livestock manure media. The purpose of this study was to analyze the productivity of earthworms (Lumbricus rubellus) in mixed media of cow manure and chicken manure with different levels. This study used a complete randomized design (RAL) with 6 treatments and 3 replications with Duncan's further test. Media used cow manure with the addition of chicken manure IPB-D1 with different levels. The results showed the use of cow dung with chicken manure addition IPB-D1 significant effect (P<0.05) on productivity of earthworms. The use of cow manure as much as 95% with the addition of chicken manure as much as 5% effect and could increase population of earthworms (Lumbricus rubellus) as much as 285.67 g and shrinkage of the media by 164.17 g. The use of 85% cow manure with the addition of 15% chicken manure could increase the weight of earthworms by 17.09 g and cocoon production by 155.58 grains. The use of cow manure with the addition of chicken manure exceeds 15% could actually reduce the productivity of earthworms Lumbricus rubellus.
Keyword: cattle manure, chicken manure, Lumbricus rubellus, productivity

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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