Judul: Post-recovery Pine Tapping Productivity at KPH Bogor Regional Division of West Java and Banten Perum Perhutani
Abstrak: Permintaan produksi getah pinus terus meningkat, namun produksi getah pinus menurun. Salah satu penyebabnya yaitu karena tegakan pinus mengalami jenuh sadap (belum saatnya untuk ditebang namun bidang sadap sudah habis). Produktivitas getah pinus pascapemulihan yaitu sadapan pinus yang dilakukan pada bidang sadap yang telah mengalami penutupan luka belum diketahui. Penelitian ini bertujuan untuk mengukur persentase pemulihan bidang sadapan pinus metode quarre dan menganalisis produktivitas sadapan pinus pascapemulihan pada kedua kelas umur pohon. Rancangan percobaan yang digunakan adalah rancangan acak kelompok terdiri dari dua perlakuan yaitu sadapan pascapemulihan dan kontrol sedangkan kelompok yaitu tegakan pinus kelas umur (KU) IV dan IX. Hasil penelitian menunjukkan rata-rata pemulihan bidang sadapan pinus KU IX lebih tinggi dibandingkan KU IV. Rata-rata produktivitas getah pinus (g/pohon/hari) perlakuan pascapemulihan lebih rendah dibandingkan kontrol pada kedua kelas umur yaitu KU IV dan KU IX perlakuan pascapemulihan berturut-turut 8,11 g/pohon/hari dan 9,15 g/pohon/hari sedangkan perlakuan kontrol berturut-turut 11,42 g/pohon/hari dan 10,59 g/pohon/hari. Perlakuan (pascapemulihan dan kontrol) sadapan getah pinus menghasilkan produktivitas yang berbeda sedangkan kelas umur menghasilkan produktivitas yang sama., The demand for pine resin continues to increase along with the declining of pine resin production. One of the reasons is because the pine trees have become saturated with tapping (it is not proper yet to cut down, but the tapping fields have run out). Post-recovery pine resin productivity, namely pine tapping in a tapping area that had undergone closure of the tapping wound not yet known. This study aimed to measure the percentage of pine tapping field recovery using the quarre method and to analyze the productivity of post-recovery pine resin in both age classes of trees. The experimental design used a randomized block design consisting of two treatments, namely post-recovery and control, while the group consisted of pine stands of age class IV and IX. The results showed that the average recovery of the pine tapping field in age class IX was higher than age class IV. The average productivity of pine resin (g/tree/day) in post-recovery treatment was lower than the control in both age classes, namely age class IV and IX in post-recovery treatment, respectively 8.11 g/tree/day and 9.15 g/tree/day while the control treatments were 11.42 g/tree/day and 10.59 g/tree/day, respectively. Treatments (post-recovery and control) on tapped pine resin had a different productivity, while the groups (age class) had the same productivity.
Keyword: post-recovery, pine resin, productivity, tapping field recovery

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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