Judul: Cempedak Seed Seedball Trial enriched with Trichoderma spp. in West Kalimantan Bauxite Post-mining Land
Abstrak: Kegiatan pertambangan memiliki dampak gangguan lingkungan antara lain hilangnya vegetasi hutan, flora dan fauna serta lapisan tanah pucuk. Perbaikan lahan bekas tambang dapat dilakukan dengan kegiatan revegetasi salah satunya dengan penanaman jenis pohon cempedak (Artocarpus integer). Penggunaan media seedball yang diperkaya Trichoderma spp. diharapkan dapat meningkatkan daya kecambah serta pertumbuhan bibit cempedak. Tujuan penelitian ini yaitu untuk Menganalisis pengaruh seedball yang diperkaya dengan Trichoderma spp. terhadap persen kecambah dan persen hidup benih cempedak dan pertumbuhan bibit cempedak di lahan bekas tambang bauksit. Penelitian ini menggunakan rancangan acak lengkap (RAL) dengan dua belas perlakuan dan lima ulangan. Perlakuan terdiri dari pasangan perlakuan metode penanaman (media seedball dan penanaman secara langsung) dengan berbagai dosis Trichoderma spp. 0 g, 5 g, 10 g, 15 g, 20 g, dan 25 g. Benih cempedak yang ditanam memiliki persen kecambah dan persen hidup sebesar 100% untuk semua perlakuan. Perlakuan K (Trichoderma 25 g dengan seedball) memberikan hasil terbaik pada parameter laju perkecambahan, nilai kecambah, diameter, dan jumlah daun semai cempedak. Perlakuan I (Trichoderma 20 g dengan seedball) menunjukkan respon terbaik pada parameter tinggi semai cempedak.
Keyword: diameter, forest, Trichoderma spp., vegetation

Judul: The Seedball Usage on (Samanea saman) Plantation on Ex-Bauxite Mining Land
Abstrak: Kegiatan reklamasi lahan pascatambang bertujuan memulihkan kembali fungsi lingkungan di areal bekas tambang dan sekitarnya. Salah satu jenis tanaman pionir yang mampu beradaptasi di lahan pascatambang adalah trembesi (Samanea saman). Seedball diaplikasikan pada benih dengan melapisi benih dengan media yang mendukung benih untuk berkecambah. Penelitian ini bertujuan untuk menganalisis pengaruh pengunaan seedball terhadap perkecambahan benih dan pertumbuhan trembesi di lahan bekas tambang serta menganalisis pengaruh metode tanam terhadap perkecambahan dan pertumbuhan seedball trembesi. Penelitian ini menggunakan rancangan acak lengkap (RAL) faktorial dengan dua faktor yaitu penggunaan media seedball dan metode tanam. Hasil penelitian menunjukkan bahwa perlakuan seedball tidak berpengaruh nyata pada diameter, tinggi, dan jumlah daun trembesi. Perlakuan P2Q2 memberikan hasil tertinggi pada persen kecambah (78%), persen hidup (100%), dan nilai kecambah (7,12%/hari), sedangkan perlakuan P1Q1 memberikan hasil terendah pada persen kecambah (8%), persen hidup (30%), dan nilai kecambah (0,08%/hari). Faktor penggunaan media seedball menunjukkan hasil tertinggi pada persen kecambah yaitu antara 65% (P2Q1) hingga 78% (P2Q2), serta nilai kecambah antara 2,86%/hari (P2Q1) hingga 7,12%/hari (P2Q2)., Post-mining land reclamation activities aim to restore environmental functions in the ex-mining area and its surroundings. One type of pioneer plant that is able to adapt to post-mining land is trembesi (Samanea saman). Seedballs are applied to seeds by coating the seeds with a medium that supports the seeds to germinate. This study aims to analyze the effect of the use of seedball on seed germination and growth of trembesi on ex-mining land and analyze the effect of planting method on germination and growth of trembesi seedball. This study used a factorial completely randomized design (CRD) with two factors, namely the use of seedball media and planting methods. The results showed that the seedball treatment had no significant effect on the parameters of diameter, height, and number of trembesi leaves. The P2Q2 treatment gave the highest yield at percent sprouts (78%), percent live (100%), and sprout value (7.12%/day), while the P1Q1 treatment gave the lowest yield at percent sprouts (8%), percent live (30 %), and germination value (0.08%/day). The factor of using seedball media showed the highest yield on the percentage of sprouts, which was between 65% (P2Q1) to 78% (P2Q2), and the sprout value was between 2.86%/day (P2Q1) to 7.12%/day (P2Q2).
Keyword: seedball, Samanea saman, bekas tambang, metode tanam

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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