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: Produktivitas Penyadapan dan Pengumpulan Getah Pinus (Pinus merkusii) di RPH Wagir, BKPH Kepanjen, KPH Malang
Abstrak: Salah satu upaya meningkatkan produktivitas getah pinus yaitu dengan melakukan perhitungan untuk mengetahui besaran produktivitas. Faktor-faktor yang memengaruhi produktivitas penyadapan dan pengumpulan juga harus diketahui agar dapat menjadi evaluasi untuk meningkatkan produktivitas. Tujuan dari penelitian ini menganalisis nilai produktivitas dari penyadapan dan pengumpulan getah pinus dan menganalisis pengaruh kemiringan lahan, diameter, dan waktu kerja. Metode penelitian menggunakan time study. Hasil dari penelitian yang dilakukan diperoleh produktivitas penyadapan dan pengumpulan pada KU VI curam sebesar 21,262 pohon jam-1 dan 29,188 kg jam-1. KU VI datar produktivitas penyadapan sebesar 7,736 pohon jam-1 dan pengumpulan sebesar 15,344 kg jam-1. Produktivitas penyadapan dan pengumpulan KU IV curam sebesar 22,607 pohon jam-1 dan 34,371 kg jam-1. Produktivitas penyadapan dan pengumpulan pada KU IV datar sebesar 20,906 pohon jam-1 dan 30,839 kg jam-1. Faktor yang memengaruhi produktivitas pada penyadapan dan pengumpulan yaitu waktu kerja yang memiliki hubungan sangat kuat dan berbanding terbalik. Kemiringan lahan tidak memiliki hubungan terhadap produktivitas penyadapan dan pengumpulan. Diameter tidak memiliki hubungan juga terhadap produktivitas pengumpulan., One of the efforts, to increase the productivity of pine resin, is to do calculations to find out the amount of productivity. Factors that affect tapping and collection productivity should be identified so that they can be used as an evaluation in order to increase productivity. The purpose of this study is analyze the productivity of tapping and collecting pine resin and analyze the effect of the slope, diameter, and work time. This study method is time study. The result of the research conducted obtained tapping and collection productivity at KU VI steep is 21,262 trees hour-1and 29,188 kg hour-1. KU VI flat the productivity that is tapping of 7.736 trees hour-1and collection of 15.344 kg hour-1. The productivity of KU IV steep tapping and collecting is 22,607 trees hour-1 and 34,371 kg hour-1. In addition, the productivity of tapping and collection at KU IV flat is 20,906 trees hour-1 and 30,839 kg hour-1. The factors which affect productivity in tapping and collection are that working time which has a very strong and inversely significant correlation. The slope has no significant correlation to productivity in tapping and collection. The diameter has no significant correlation to productivity in the collection.
Keyword: pine resin, time study, working time, productivity

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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