Judul: Pine Oleoresin Tapping with Post-recovery Drill Method
Abstrak: Metode bor merupakan metode penyadapan dengan jangka waktu pemulihan relatif cepat sekitar 2-3 tahun. Salah satu lokasi yang mempunyai petak sadapan yang telah pulih adalah Hutan Pendidikan Gunung Walat. Lubang sadap bor yang telah pulih tertutup oleoresin dan telah mengeras hingga membentuk kulit dan kayu yang baru. Lubang sadap ini dapat terbuka kembali apabila dilakukan pengeboran ulang. Penelitian ini menggunakan ukuran mata bor 5/8 inci, 6/8 inci dan 7/8 inci sebagai perlakuan pascapemulihan. Selain itu dilakukan pengeboran bidang sadap baru pada pohon yang sama sebagai kontrol dengan ukuran mata bor yang sama. Hasil penelitian menunjukkan produktivitas oleoresin pinus pascapemulihan lebih rendah dibandingkan bidang sadap baru. Ukuran mata bor berpengaruh nyata terhadap produktivitas oleoresin pinus pascapemulihan. Ukuran mata bor 7/8 inci menghasilkan produktivitas paling tinggi, sehingga ukuran mata bor 7/8 inci dapat dijadikan solusi dalam penyadapan oleoresin pinus pascapemulihan. Kata kunci : oleoresin, pascapemulihan, produktivitas, ukuran mata bor, The drill method is a tapping method with a relatively fast recovery period, which is around 2-3 years. One of the locations that has recovered intercepts is the Gunung Walat Educational Forest. The recovered drill tapping holes are covered with oleoresin and have hardened so that it forms new bark and wood. This tapping hole can be re-opened if it is re-drilled. This study used drill bit sizes of 5/8 inch, 6/8 inch and 7/8 inch as post-recovery treatment. Beside that a new tapping area was drilled on the same tree as a control variable using the same drill bit size. The results showed that post-recovery pine oleoresin productivity was lower than the new tapping field. The size of the drill bit has a significant effect on the productivity of post-recovery pine oleoresin. The 7/8 inch drill bit provides the highest productivity, so that the 7/8 inch drill bit can be used as a solution in post-recovery pine oleoresin tapping. Keywords: drill bit size, oleoresin, post-recovery, productivity
Keyword: oleoresin, pascapemulihan, produktivitas, ukuran mata bor

Judul: The effect of pipe perforation on the productivity  of pine oleoresin using the drill method
Abstrak: Metode bor merupakan metode tertutup sehingga udara yang berada di dalam wadah penampung tidak terhubung dengan udara luar. Ketika oleoresin keluar dari saluran getah maka akan menekan udara yang ada di dalam wadah penampung dan terjadi tekanan udara balik yang menghambat keluarnya getah. Penelitian ini menggunakan 5 perlakuan berbeda yaitu perlakuan A dengan metode bor dan penampung getah berupa mangkok plastik tertutup, perlakuan B dengan metode bor menggunakan pipa yang tidak dilubangi, perlakuan C berupa metode bor tanpa pipa, perlakuan D berupa metode bor menggunakan pipa yang telah dibuat 1 lubang, dan perlakuan E berupa metode bor menggunakan pipa yang telah dibuat 2 lubang. Hasil penelitian menunjukkan metode bor dengan pipa yang telah dibuat 2 lubang memberikan hasil yang paling tinggi. Sehingga penggunaan pipa yang dibuat 2 lubang dapat dijadikan solusi dalam penyadapan oleoresin pinus agar menghasilkan getah yang lebih banyak dibandingkan metode bor dengan pipa yang tidak dilubangi., The drill method is a method of closing the air that is in the container not connected to the outside air. When oleoresin comes out of the sap channel, it will press on the container and air pressure will occur which inhibits the release of sap. This study used 5 different treatments, namely treatment A with a drill method and a sap reservoir in the form of a closed plastic bowl, B with a drill method using a pipe that is not perforated, treatment C in the form of a drill method without a pipe, treatment D in the form of a drill method using a pipe that has been made 1 hole, and treatment E in the form of a drill method using a pipe that has been made 2 holes. The results showed that the drill method with a pipe that had 2 holes made gave the highest results. So that the use of pipes made of 2 holes can be used as a solution in tapping pine oleoresin to produce more sap compared to the drill method with pipes that are not perforated.
Keyword: air, drill method, pipe perforation, presussure, productivity

Judul: Metrik Einstein (Anti-) Self-Dual Berdimensi Empat dengan Metode Cartan
Abstrak: Gravitational field equation can be formulated in differential forms (differential geometry), which describes gravity as a manifestation of the curvature of space-time. Curvature of space-time is characterized by a metric that satisfies the gravitational field equation. With differential forms it can be formulated the (anti-) self-dual Einstein equation, which is a modification of the Cartan structure in (anti-) self-dual basis. Calculation of (anti-) self-dual metric with (anti-) self-dual Einstein equation is simpler than the calculation using Christoffel symbols.
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