Judul: Analisis Kultivasi Jamur Kuping (Auricularia sp.) pada Log Kayu dan Ranting Sengon, Jabon dan Jati
Abstrak: One of the alternative media for ear mushroom (Auricularia sp.) cultivation is by using cutting wastes of log and twigs. The objective of this research is to analyze the potency of ear mushroom cultivation by using log and twigs from three species e.g sengon (F. moluccana), jabon (A. cadamba) and jati (T. grandis). This research is completely randomized design with 8 treatments of logs and twigs from the trees species, baglog from sengon sawdust nutrition given (BIO) and sengon sawdust only (CS). Fresh weight of ear mushroom from jabon stem (171.4 g) was higher than other treatments, except BIO treatment (248.4 g). Biology efficiency (EB) of jabon twigs (39.8%) is significantly higher than the other treatments, except for BIO treatment (67.6 %). The average of harvesting time of teak log (36 days) and teak twigs (34 days) were significantly higher than the other treatments. The results clearly showed that log and twigs from that three species could be used for ear mushroom cultivation media to substitute the use of sawdust.
Keyword: T. grandis. Cultivation media, F. moluccana, Auricularia sp., A. cadamba

Judul: Identification Wild Ear Mushroom and Its Cultivation Trial with the Addition Crystal Guava Leaf Litter
Abstrak: Keragaman jamur liar edible (JLE) dan kultivasinya belum banyak diketahui dan dimanfaatkan dengan baik di Indonesia. Salah satu JLE dengan informasi yang minim adalah jamur kuping liar Auricularia spp., padahal JLE tersebut berpotensi dikembangkan sebagai bahan konsumsi bergizi. Disisi lain, produksi jamur kuping komersial (JKK) di Indonesia tiap tahunnya meningkat, sehingga menyebabkan peningkatan permintaan bibit jamur dan serbuk kayu. Penelitian ini bertujuan untuk mengidentifikasi spesies jamur kuping liar dan membudidayakannya dengan substrat tambahan serasah daun jambu kristal. Pengambilan sampel dilakukan dengan metode oportunistik. Sampel diisolasi dan dianalisis secara morfologi serta molekuler untuk diketahui posisi taksonominya. Hasil identifikasi mengkonfirmasi beberapa spesies jamur kuping liar diantaranya Auricularia cf. auricula-judae, Auricularia cornea, Auricularia cf. fuscosuccinea, dan Auricularia cf. nigricans. Jamur kuping liar yang berhasil diisolasi dan dibuat bibit adalah A. cornea, namun belum mampu tumbuh pada baglog, sehingga serasah diujikan pada budidaya JKK. Penambahan substrat serasah daun jambu kristal pada konsentrasi 0, 5, 10 dan 100%. Keberhasilan budidaya jamur dilihat dari nilai efisiensi biologis setiap perlakuannya. Substrat dengan penambahan daun jambu kristal 10% memiliki efisiensi biologis tertinggi. Hasil budidaya JKK menunjukkan adanya potensi dari serasah daun jambu kristal sebagai campuran substrat baglog., The diversity and cultivation of edible wild mushroom in Indonesia hasn't been widely known in Indonesia. One of them is Auricularia spp. Edible wild mushrooms are potentially used as nutritious food. The production of mushroom in Indonesia developed each year causing increase in demand of mushroom seeds and wood powder. This research was carried out to identify and cultivate the wild mushroom with crystal guava leaf litter as substrate additive. The sampling was done by opportunistic method. The samples were isolated and analyzed morphologically and also at molecular level for their taxonomy identification. The identification resulted in four different species: Auricularia cf. auricula-judae, Auricularia cornea, Auricularia cf. fuscosuccinea, Auricularia cf. nigricans. Wild mushroom that successfully isolated and seeded was A. cornea, but it failed to grow in baglog. Based on that reason, crystal guava leaf litter was tested to cultivate commercial mushroom. The concentrations of crystal guava leaf litter used were 5, 10, and 10%. The success indicator of mushroom cultivation is their biological efficiency in every treatment. Substrate with 10% addition of crystal guava leaf litter demonstrated the highest biological efficiency rate. The cultivation result of mushroom indicated that crystal guava leaf litter is potential as a substrate mixture in baglog.
Keyword: Auricularia, commercial, substrate, wild 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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