Judul: Evaluasi Kerusakan Pohon Jalur Hijau Jalan Yang Disebabkan oleh Tanaman Strangler (Pencekik) di Kota Bogor
Abstrak: Pohon jalur hijau jalan di sejumlah tempat di Kota Bogor ditumbuhi oleh tanaman pencekik. Tanaman pencekik dapat menjadi penyebab tumbangnya pohon jalur hijau dan membahayakan keselamatan. Oleh karena itu, penelitian ini dilakukan untuk melakukan analisis vegetasi tanaman pencekik di Kota Bogor, mengevaluasi kerusakan yang disebabkan oleh tanaman pencekik, dan menyusun rekomendasi pemeliharaan pohon yang terkena tanaman pencekik. Penelitian ini dilakukan dengan metode survei di Jalan Jend. Ahmad Yani, Jalan Ir. H. Juanda, Jalan Pemuda, Jalan Dr. Semeru, dan Jalan Jend. Sudirman. Data yang dikumpulkan mencakup spesies dan jumlah tanaman pencekik beserta pohon inangnya; diameter pohon; tinggi inang dan tanaman pencekik; kelebatan akar dan tajuk pencekik. Hasil penelitian menunjukkan bahwa spesies pencekik yang ditemukan di Kota Bogor, antara lain, adalah Ficus benjamina, Ficus glauca, Ficus elastica, dan Schefflera actinophylla. Spesies yang paling banyak ditemukan adalah F. benjamina dengan indeks nilai penting sebesar 185,9. Di antara kelima lokasi penelitian, jalur hijau yang mengalami kerusakan paling tinggi adalah Jalan Pemuda dengan jumlah pohon yang rusak sebesar 37,9% dari total pohon rusak di seluruh lokasi penelitian. Pemeliharaan pada pohon jalur hijau yang tercekik berbeda bergantung pada tingkat kerusakan yang dialaminya.
Keyword: dominansi, frekuensi, kelimpahan, pemeliharaan pohon, pohon jalur hijau, tanaman pencekik

Judul: Evaluasi Kerusakan Fisik Pohon dalam Upaya Mitigasi Pohon Tumbang pada Jalur Hijau Jalan di Jakarta Pusat
Abstrak: The presence of trees at the roadside greenbelt has the greatest influence among other vegetation types in improving the environmental quality. Therefore, the physical condition of tree became things to note because can result of a broken tree branches or twigs or fall of a tree which can lead to traffic accidents that would endanger the safety of road users. This study aims to analyze trees phsycal force to find the resistance of a broken tree branches or twigs or fall of a tree. In this case, the roads have been surveyed including H. Agus Salim Street, Teuku Umar Street, Diponegoro Street, Imam Bonjol Street, Sutan Syahrir Street, dan Moh. Yamin Street in Central Jakarta. The collected data are species and number of tree, type of damaged, place of damaged, condition of damaged, and incident of fallen tree in location. The data were analyzed with plant physiognomy approach. There are 1.646 trees were observed in six roadside greenbelt and 1.413 of them were damaged. Based on value of index tree damage classification 650 including healthly trees, 847 low damaged trees, 167 medium damaged trees, and 12 high damaged trees. Handling of each trees adjusted base on type and severity of damaged based on eradication and protection principles.
Keyword: Bogor Agricultural University (IPB), roadside greenbelt, physical damages, mitigate, fallen trees

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: