Judul: Respons Pertumbuhan Mahoni terhadap Pemberian Arang Sekam, Kompos, dan NPK di Taman Hutan Kampus IPB
Abstrak: Lahan Kelompok Tani Hutan Kemang Sawargi yang terletak di Taman Hutan Kampus IPB memiliki kondisi tanah dengan kesuburan yang rendah. Kesuksesan penanaman dipengaruhi oleh kesuburan tanah yang baik serta pemilihan jenis yang tepat. Mahoni dipilih karena adaptif dan mampu hidup pada berbagai kondisi. Kemampuan pertumbuhan mahoni di lapangan dapat ditingkatkan dengan memberikan arang sekam, kompos, dan NPK. Penelitian ini bertujuan mengetahui respons pertumbuhan terhadap pemberian arang sekam, kompos, NPK, dan kombinasinya di lapangan. Interaksi perlakuan arang sekam, kompos, dan NPK memberikan pengaruh nyata terhadap pertambahan tinggi, jumlah akar, dan panjang akar mahoni. Faktor tunggal kompos memberikan pengaruh yang sangat nyata terhadap pertambahan tinggi, jumlah akar dan panjang akar mahoni. Pemberian kompos tanpa arang sekam dan NPK memberikan hasil terbaik bagi pertumbuhan parameter mahoni berupa tinggi, jumlah akar dan panjang akar., The land of Kelompok Tani Hutan Kemang Sawargi located in Taman Hutan Kampus IPB has soil conditions with low fertility. The success of planting is influenced by good soil fertility and the selection of the right type. Mahogany was chosen because it is adaptive and able to withstand various conditions. Mahogany growth ability in the field can be increased by providing husk charcoal, compost, and NPK. This study aims to determine the growth response to the provision of husk charcoal, compost, NPK, and their combination in the field. The interaction of husk charcoal, compost, and NPK treatments had a significant effect on the increase in height, number of roots, and root length of mahogany. The single factor of compost had a very significant effect on the increase in height, number of roots, and root length of mahogany. Provision of compost without husk charcoal and NPK gave the best results for the growth of mahogany parameters in the form of height, number of roots, and root length.
Keyword: compost, growth, husk charcoal, mahogany, NPK

Judul: Pertumbuhan Bibit Mahoni (Swietenia macrophylla King.) pada Media Tanam dan Intensitas Naungan yang Berbeda
Abstrak: Swietenia macrophylla King. berpotensi di bidang ekonomi, kesehatan dan lingkungan, sehingga pohon ini salah satu spesies yang digunakan untuk rehabilitasi hutan. Pertumbuhan S. macrophylla dipengaruhi oleh faktor lingkungan, di antaranya kualitas media tumbuh serta intensitas naungan. Penelitian ini bertujuan untuk mendapatkan media tanam dan naungan yang tepat untuk pertumbuhan benih S. macrophylla. Penelitian ini dilaksanakan dengan menggunakan rancangan petak terbagi dengan acak kelompok. Petak utama adalah naungan menggunakan paranet yang terdiri atas 2 taraf, sedangkan anak petak adalah media tanam yang terdiri atas 5 taraf. Hasil penelitian menunjukkan adanya interaksi perlakuan media tanah mineral tanpa naungan menghasilkan tinggi tanaman dan bobot basah total tertinggi pada bibit mahoni. Perlakuan media tanah mineral dan arang sekam menghasilkan pertumbuhan terbaik pada diameter batang, jumlah dan luas daun, jumlah akar, bobot kering total dan indeks mutu bibit mahoni. Perlakuan tanpa naungan menghasilkan pertumbuhan terbaik pada diameter batang, jumlah dan luas daun, jumlah dan panjang akar, bobot kering total dan indeks mutu bibit mahoni pada umur 9 minggu setelah tanam, Swietenia macrophylla has potential in the economic, health and environmental sectors; so this tree is one of the species used for forest rehabilitation. The growth of S. macrophylla is influenced by environmental factors, including the quality of the growing media and shade intensity. This study aimed to obtain the right planting medium and shade for the growth of S. macrophylla seedlings. This research was conducted using a split-plot design with randomized groups. The main plot was shade using paranet which consists of 2 levels, while the subplot was the planting medium which consists of 5 levels. The results showed that the interaction of mineral soil media treatment without shade resulted in the highest plant height and total wet weight in mahogany seedlings. Treatment of mineral soil media and husk charcoal produced the best growth in stem diameter, number and area of leaves, number of roots, total dry weight and quality index of mahogany seedlings. Treatment without shade produced the best growth in stem diameter, number and area of leaves, number and length of roots, total dry weight and quality index of mahogany seedlings at the age of 9 weeks after planting
Keyword: intensitas naungan, media tanam, Swietenia macrophylla King.

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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