Judul: Cultivation of Two Edible Mushrooms on Wood and Branches of Sengon (Paraserianthes falcatraria), Moringa (Moringa oleifera), and Kicopong (Cecropia peltata) Branches., Cultivation of Two Edible Mushrooms on Wood and Branches of Sengon (Paraserianthes falcatraria), Moringa (Moringa oleifera), and Kicopong (Cecropia peltata) Branches.
Abstrak: Jamur tiram (Pleurotus ostreatus) dan jamur kuping (Auricularia auricula) termasuk jenis jamur pangan yang banyak dibudidayakan. Saat ini, dibandingkan jenis kayu sengon (Paraserianthes falcataria), kayu kelor (Moringa oleifera), dan kayu kicopong (Cecropia peltata) merupakan jenis kayu yang penggunaannya masih cukup rendah. Penelitian ini bertujuan menganalisis potensi kayu sengon, kelor, dan kicopong (batang dan ranting) untuk kultivasi jamur tiram dan jamur kuping. Penelitian menggunakan rancangan acak lengkap (RAL) dengan dua faktor yaitu jenis media dan jenis jamur. Jenis media adalah log dan ranting serta baglog sebagai pembanding. Hasil penelitian menunjukkan bahwa jamur yang dikultivasi pada media baglog memiliki hasil yang tertinggi dibanding log dan ranting. Jika dilihat dari media batang dan ranting, ketiga jenis kayu memiliki potensi yang baik sebagai media kultivasi jamur, dengan kicopong sebagai media terbaik. Hama dan penyakit yang cenderung mengganggu pertumbuhan kultivasi jamur adalah jenis Stemonitis sp. dan Corpinus sp., Oyster mushrooms (Pleurotus ostreatus) and ear mushrooms (Auricularia auricula) are among the most widely cultivated types of food mushrooms. At present, compared to sengon wood (Paraserianthes falcataria), kelor (Moringa oleifera), and kicopong (Cecropia peltata) wood are types of wood whose usage is still quite low. This study aims to analyze the potential of sengon, moringa, and kicopong (logs and twigs) wood for the cultivation of oyster mushrooms and ear mushrooms. The study used a completely randomized design (CRD) with two factors, namely the type of media and the type of fungus. Types of media are logs and branches and baglogs for comparison. The results showed that fungi cultivated on baglog media had the highest yield compared to fungi that were cultivated on logs and twigs. When viewed from the stem and twig media, the three types of wood have good potential as a medium for mushroom cultivation, with kicopong as the best medium. Pests and diseases that tend to interfere with the growth of fungal cultivation are Stemonitis sp. and Corpinus sp.
Keyword: Auricularia auricula, Cecropia peltata, Moringa oleifera, Paraserianthes falcataria, Pleurotus ostreatus

Judul: Growth and Production Of Oyster Mushroom (Pleurotus spp.) on Media Containing Sengon Wood, Coffee Skin, and Straw
Abstrak: Jamur tiram merupakan salah satu kelompok jamur kayu yang dapat dimakan (edible). Pemanfaatan limbah hasil kehutanan dan pertanian seperti serbuk gergaji kayu sengon, kulit kopi, dan jerami menjadi salah satu yang dapat dimanfaatkan sebagai media tanam dalam kultivasi jamur tiram guna memaksimalkan limbah yang ramah lingkungan. Penelitian bertujuan untuk menganalisis pengaruh media yang mengandung kayu sengon, kulit kopi, dan jerami terhadap pertumbuhan dan produksi jamur tiram. Penelitian menggunakan Rancangan Acak Lengkap (RAL) faktor tunggal dengan 3 perlakuan media yaitu formula 1 (kayu sengon dan kulit kopi), formula 2 (kayu sengon dan jerami), dan kontrol (kayu sengon). Hasil penelitian menunjukkan bahwa fase vegetatif jamur paling singkat diperoleh pada media formula 2 (15-18 hari). Fase generatif jamur yang membutuhkan waktu paling cepat masa panen diperoleh pada media kontrol (9-11 hari). Total bobot basah jamur terbesar dan nilai efisiensi biologis tertinggi diperoleh pada media kontrol (229,10 g) dengan nilai efisiensi biologis 79,0% pada jamur tiram putih (Pleurotus ostreatus) dan (331,70 g) pada jamur tiram cokelat (Pleurotus cystidiosus) dengan nilai efisiensi biologis 114,4%., Oyster mushroom is a group of edible wood mushrooms. Utilization of forestry and agricultural waste such as sawdust from sengon wood, coffee husks, and straw is one that can be used as a planting medium in oyster mushroom cultivation in order to maximize environmentally friendly waste. This study aims to analyze the effect of media containing sengon wood, coffee skin, and straw on the growth and production of oyster mushrooms. The study used a single factor completely randomized design (CRD) with 3 media treatments, namely formula 1 (sengon wood and coffee husk), formula 2 (sengon wood and straw), and control (sengon wood). The results showed that the shortest fungal vegetative phase was obtained in formula 2 media (15-18 days). The fungal generative phase wich required the fastest time to harvest was obtained in control media (9-11 days). The highest total wet weight of mushrooms and the highest biological efficiency value obtained on control media (229,10 g) with a biological efficiency value of 79,0% on white oyster mushroom (Pleurotus ostreatus) and (331,70 g) on brown oyster mushroom (Pleurotus cystidiosus) with a biological efficiency value of 114,4%.
Keyword: brown oyster mushroom, coffee husk, sengon wood, straw, white oyster mushroom.

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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