Judul: Penggunaan Bio Soil Booster untuk Perbaikan Kualitas Tanah pada Lahan Bekas Tambang Batubara
Abstrak: Revegetation activities at the former mines often experience many obstacles such as the low soil pH, soil compaction, low nutrient content, and contain toxic materials on the ground. Improvement of soil quality needs to be done to support the success of reclamation. Improvement of soil quality can be done by adding bio soil booster on the ground soil. This research aims to know the influence of bio soil booster on granting the land ex coal mining with sorgum (Sorghum bicolor Linn.) as an indicator of soil quality. Bio soil booster used consisting of four concentration levels, namely concentration of 0%, concentration of 0.4%, concentration of 0.2%, concentration of 0.1%. Planting media consisting of six soil types, the land top soil and five a type of soil land a former coal mines derived from different location in PT. Jorong Barutama Greston tbk. Responses observed are growth was high, the long roots, the performances of roots and leaves. The use of bio soil booster in a planting media can increased an average of a height and length „s root S. bicolor and to increase its performance root and leaves, this indicates an increase in the quality of the soil in a planting media. The use of bio soil booster effective the first concentration 0.4% and a 0.2%.
Keyword: Bogor Agricultural University (IPB), soil quality, S. bicolor, bio soil booster

Judul: Seedball and Bioenzyme Application for Land Reclamation Post Limestone Mining, Gunung Putri, Bogor.
Abstrak: Mining causes a decrease in land carrying capacity and soil fertility, so it is necessary to reclaim ex-mining land. To accelerate and reduce the cost of ex-mining land reclamation activities, it is necessary to make technological breakthroughs. Forest rehabilitation using seedball has been widely reported, but has not yet been tested on ex-mining land. Seedball is a technique of seed wrapping to protect seeds from predators and extreme environmental conditions, and provide initial nutrition to seeds after germination. Bioenzymes and manure are needed to support seedling growth in ex-mining lands, which are generally nutrient-poor. The purpose of this study was to find the right composition of seedball ingredients for planting durian (Durio zibethinus), jackfruit (Artocarpus heterophyllus), bisbul (Diospyros blancoi), merbau (Intsia bijuga) and gmelina (Gmelina arborea) seeds on lime ex- mining land, analyzed the effect of seedball and bioenzyme application on plant growth used and analyzed mycorrhizal colonization on plant roots used in limestone ex-mining land. The seedball formulation test used three formulations, namely Formula A (clay and compost), Formula B (clay, compost, and insecticide), and Formula C (clay, sawdust, vermicompost, and bone meal). The design used was a factorial Completely Randomized Design (CRD) with 2 factors. The first factor is the seedball formula, and the second factor is the type of plant where each treatment combination was repeated 3 times. After the best formula was obtained, a planting test was carried out on PT SBI's ex-mining land using the best formula. At the age of 12 weeks after planting (MST) the seeds were given bioenzymes and manure with a Split Plot design. Furthermore, the parameters of germination, germination rate, seedling height, stem diameter, number of leaves, and mycorrhizal colonization on seedling roots were observed by staining method. The result of this research is the best seedball’s formulations is formula C. The results of the planting test on the ex-mining land of PT SBI were the seeds that grow well are jackfruit and merbau. The best fertilization treatment is a combination of bioenzymes and manure. The roots of all plant species in the study area were also colonized by mycorrhizae, and the highest colonization was found in gmelina with a colonization percentage 80.95%. Based on the description above, it can be concluded that the best compositions for making seedballs are clay, sawdust, vermicompost, and bone meal (8:8:2:1), and the seedball technique, application of bioenzymes and manure using jackfruit and merbau types can be used to accelerate the reclamation and rehabilitation of ex-limestone mining land., Pertambangan menyebabkan penurunan daya dukung lahan dan kesuburan tanah, sehingga perlu dilakukan reklamasi lahan bekas tambang. Upaya untuk mempercepat dan menekan biaya kegiatan reklamasi lahan bekas tambang diperlukan terobosan teknologi. Rehabilitasi lahan menggunakan seedball telah banyak dilaporkan, tetapi belum diujicobakan di lahan bekas tambang. Seedball merupakan teknik pembungkusan benih untuk melindungi benih dari predator dan kondisi lingkungan yang ekstrim, serta untuk memberikan nutrisi awal pada benih setelah berkecambah. Bioenzim dan pupuk kandang diperlukan untuk mendukung pertumbuhan bibit di lahan bekas tambang yang miskin hara. Tujuan dari penelitian ini adalah menemukan komposisi bahan pembuat seedball yang tepat untuk menanam
Keyword: seedball, bioenzymes, rehabilitation, degraded land, plant growth

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.
Keyword: