Judul: Penggunaan Stimulansia ETRAT pada Penyadapan Getah Pinus merkusii, Pinus oocarpa dan Pinus insularis di Hutan Pendidikan Gunung Walat
Abstrak: Indonesia has the level of biodiversity that is high enough. One of them is pine tree. Pine trees can be used as a timber, but it also produce resin that can be processed into Gumrosin and turpentine. In Gunung Walat University Forest has 3 species kind of pine are P. merkusii, P. oocarpa, and P. insularis. Pine tapping productivity can methode by increase tapping technique and optimally at using stimulant. In Gunung Walat University Forest only pine tapping productivity from P. merkusii had be knowing. Therefore, it is necessary to research about productivity Pine resin the use of stimulant ETRAT especially P. oocarpa and P. insularis. The research uses 40 trees for each species of pine, 20 trees are used as control (without the stimulant) and 20 other trees using stimulant. The periode treatments resin collecting once 3 days with total observation as many 15 times. The observation weighed use scales digital. Based on this research, the highest average productivity is P. merkusii the use of stimulant ETRAT treatment that is 19,93 grams/quarre/day, followed by P. oocarpa and P. insularis with respective 19,29 grams/quarre/day and 14,95 grams/quarre/day. The percentage of increase in the resin after using stimulant ETRAT on P. merkusii that is equal 117,81%, 62,85% for P. oocarpa and 76,19% for P. insularis. The use of stimulant ETRAT value-added productivity of the pine resin tapping amound Rp 76,85/quarre/day for P. merkusii, Rp 51,73/quarre/day for P. oocarpa, and Rp 48,8/quarre/day for P. insularis. The use of stimulant ETRAT influence productivity of pine tapping all three species of pine. Based on Duncan test, the treatment of stimulant ETRAT on P. oocarpa is no diffrent to P. merkusii and P. insularis. The use of stimulant ETRAT influence research showed productivity the tapping P. merkusii with P. insularis.
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Judul: Advanced Tapping Productivity of Pine at Various Heights in Gunung Gede Pangrango National Park
Abstrak: Perubahan fungsi Kawasan hutan dari Perum Perhutani ke Taman Nasional berdampak pada perubahan pengelolaan sumberdaya alam dan dilema dalam penentuan kebijakan. Penyadapan pohon pinus pada Kawasan konservasi perlu memperhatikan metode penyadapan yang sesuai agar kesehatan dan kelestarian tegakan terus terjaga. Penelitian ini bertujuan menghitung produktivitas sadapan lanjut getah pinus di TNGGP dan mengetahui pengaruh stimulansia pada berbagai lokasi ketinggian tempat terhadap produktivitas sadapan getah pinus. Rancangan percobaan yang digunakan adalah rancangan acak kelompok terdiri dari tiga perlakuan yaitu penggunaan stimulansia kontrol, H2SO4, dan ETRAT, sedangkan kelompok yaitu ketinggian 400-600 meter di atas permukaan laut (mdpl), 600-800 mdpl, dan >800 mdpl. Hasil penelitian menunjukkan kondisi pohon pinus terhadap standar penyadapan getah pinus pada berbagai ketinggian tidak memenuhi persyaratan yang ditentukan. Rata-rata produksi getah pinus 13,88 g/pohon/hari. Produksi getah pinus pada penggunaan stimulansia H2SO4 lebih tinggi dibanding stimulansia kontrol dan ETRAT berturut-turut 16,99 g/pohon/hari, 8,63 g/pohon/hari, dan 16,00 g/pohon/hari. Pemberian stimulansia optimal pada lokasi sadapan dengan ketinggian 600-800 mdpl. Penggunaan stimulansia ETRAT meningkatkan produktivitas getah pinus melalui fungsi ethylen yang meningkatkan proses metabolisme sekunder dalam tanaman. Penggunaan stimulansia (kontrol, H2SO4, dan ETRAT) sadapan getah pinus dan perbedaan ketinggian tempat menghasilkan produktivitas yang berbeda., The change in the function of the forest area from Perum Perhutani to a National Park has implications for the management of natural resources and poses policy dilemmas. Tapping pine trees in the conservation area needs to adhere to appropriate tapping standards to ensure the health and sustainability of the stands are continuously maintained. This research aims to calculate the productivity of extended pine resin tapping in TNGGP and understand the impact of stimulants at various elevations on pine resin tapping productivity. The experimental design used is a randomized complete block design consisting of three treatments: the use of control stimulants, H2SO4, dan ETRAT, while the groups are at elevations of 400-600 meters above sea level (masl), 600-800 masl, and >800 masl. The research result indicates that the condition of pine trees regarding pine resin tapping standards at various elevations does not meet the specified requirements. The average production of pine resin was 13,88 g/tree/day. Pine resin production with the use of H2SO4 stimulant is higher compared to the control and ETRAT stimulants, with values of 16,99 g/tree/day, 8,63 g/tree/day, and 16,00 g/tree/day, respectively. Optimal stimulant application was observed at tapping locations with elevations of 600-800 masl. The use of ETRAT stimulan increases pine resin productivity through ethylene function, which enhances secondary metabolic processes in plants. The use of stimulants (control, H2SO4, and ETRAT) in pine resin tapping and differences in elevation result in different productivity levels.
Keyword: getah pinus, produktivitas sadap lanjut, standar penyadapan, stimulansia, extended tapping productivity, pine resin, stimulants, tapping standards

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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