Judul: Kajian Pengelolaan Hutan Rakyat Sengon (Paraserianthes falcataria (L) Nielsen): Kasus Desa Kesenet, Kecamatan Banjarmangu Kabupaten Banjarnegara
Abstrak: This research aims to study the management and cultivation of sengon community forest, to presume its potential, and also to calculate the contribution of sengon and other agroforestry plants toward the farmer’s total income in Kesenet Village, Banjarmagu District, Banjarnegara Residence of Central Java. The methods of the data collection used were quantitative and qualitative method. The quantitative method was used to measure the dimension of sengon and other agroforestry plants with sixty sampling plots in 0,1 hectare of circle shape which were determined by using purposive sampling with 3,10% sampling intensity. The qualitative method was used to analyze the forest management by interviewing through questionnaires to the sixty chosen farmers who own sampling plots and by studying literature. In general, the forest management in Kesenet Village applied the land preparation and management, seeding, planting, cultivation, harvesting and marketing. The stages of the management activities have not been completely achieved because of the traditional hereditary system which was still used. The potency of sengon per hectare in Kesenet Village was estimated on the average of 79,27 m3/ha or between 50,99 m3/ha to 107,55 m3/ha. The total area of sengon in Kesenet village was 193,86 ha and then the total wood of sengon was achieved 15.368,24 m3 or between 9.863,66 m3 to 20.872,83 m3. The income contribution of sengon 4,37% and 84,68 % of salak pondoh of total income forest farmer was illustrated that the sengon cultivation still becomes a secondary business for Kesenet villagers. The efforts that should be done to develop the management of sengon community forest are both by intensifying counseling and training the sengon management technique gradually. Besides that, the market information in warranting the stability of a certain cost can make the farmers easier in bargaining position. The countermeasure of the insects, pests, and karat puru disease which have been attacking 80% sengon plants up until now needs to get a serious attention, especially to warrant the developmental continuation of society business in community forest of sengon.
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Judul: Sistem pengelolaan hutan rakyat jenis sengon [Paraserianthes falcataria (L) Nielsen] di Desa Burat, Kecamatan Kepil, Kabupaten Wonosobo, Provinsi Jawa Tengah
Abstrak: Hutan merupakan sumberdaya alam yang dalam penggunaannya dapat dipulihkan kembali (renewable). Pemanfaatan dan pengelolaan hutan bertujuan untuk meningkatkan kesejahteraan masyarakat tanpa mengabaikan aspek kelestariannya. Dalam prakteknya di lapangan masih didapatkan beberapa hal yang dirasa kurang maksimal dalam pengelolaan hutan, khususnya hutan rakyat. Karena pengelolaannya masih sederhana dan sangat bervariasi berdasarkan letak geografis dan perlakuan dari pemilik lahan. Dengan adanya beberapa cara pengembangan hutan rakyat dan dengan lebih intensifnya pengelolaan dengan cara yang lebih sustainable dengan daya dukung potensi sumberdaya hutan rakyat, kinerja pengusahaan, dinamika lingkungan dan faktor-faktor lainnya diharapkan hutan rakyat dapat menjadi suatu unit bisnis startegis yang mampu mempertahankan keberlangsungan produksi dan pengusahaanya dengan tetap memprioritaskan kelestarian hutannya. Tujuan utama dari penelitian ini, adalah untuk mempelajari sistem pengelolaan hutan rakyat dan menyusun rencana pengaturan kelestarian produksi hutan rakyat sengon di Desa Burat, Kecamatan Kepil, Kabupaten Wonosobo, Propinsi Jawa Tengah. Sumber data yang digunakan adalah data primer dan data sekunder. Data primer diperoleh dari wawancara kepada responden yang menangani produsen, pedagang, pengrajin industri dan industri pengolahan kayu. Data sekunder diperoleh dari Dinas Kehutanan Kabupaten Wonosobo, Kantor Kecamatan Kepil, Kantor Desa Burat dan browsing internet. Metode analisis yang digunakan adalah analisis kualitatif untuk data sekunder melalui hasil wawancara berdasarkan hasil kuisioner dan analisis kuantitatif untuk data primer yang berupa data potensi jenis sengon melalui pendugaan berdasarkan teknik sampling sederhana. Sistem pengelolaan hutan rakyat di Desa Burat sifatnya masih sederhana, dalam hal ini dapat dibuktikan dari tahapan kegiatan pengelolaannya seperti penanaman, pemeliharaan, pemanenan serta pemasaran masih belum mengikuti pola yang sama. Hal ini disebabkan karena sistem informasi manajemen belum efektif untuk dapat diterima oleh masyarakat petani hutan Desa Burat. Faktor-faktor penunjang dalam pengelolaan hutan rakyat seperti sarana dan prasarana masih belum merata. Sistem kelembagaan serta kebijakan yang ada belum mendukung sepenuhnya kegiatan usaha pengembangan di bidang hutan rakyat sengon di Desa Burat.
Keyword: Forest, Forest people, The concept of sustainability, Peoples forest management system, Sustainable

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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