Judul: Pengendalian Gulma Kelapa Sawit (Elaeis guineensis Jacq) di Kebun Seed Garden Buatan, PT Inti Indosawit Subur, Riau.
Abstrak: Gulma di lahan kelapa sawit yang tidak dikendalikan menurunkan hasil panen sehingga perlu pengendalian gulma yang efektif dan efisien. Magang memiliki tujuan umum meningkatkan kemampuan teknis dan manajerial dalam kegiatan budidaya kelapa sawit serta tujuan khusus menambah pemahaman dalam pengendalian gulma di Kebun Seed Garden Buatan, PT Inti Indosawit Subur, Riau. Magang dilaksanakan di KSB, PT Inti Indosawit Subur, Pangkalan Kerinci, Pelalawan, Riau pada bulan Januari sampai Mei 2023. Metode yang digunakan metode langsung (data primer) dan tidak langsung (data sekunder). Pengamatan data primer gulma dengan NJD menunjukkan gulma yang dominan di areal piringan yaitu Eleusine indica menunjukkan SDR tertinggi yaitu 45,28% pada TBM, 30,92% pada TM muda, dan 27,14% pada TM tua. Centotheca lappacea nilai SDR tertinggi pada TM muda 35,42% dan TM dewasa 55,7%. Cyperus kyllingia nilai SDR tertinggi gulma ini pada TBM yaitu 46%, TM muda yaitu 50,05%, dan TM dewasa 27,29%. Asystasia gangetica nilai SDR tertinggi di TM dewasa senilai 17,03%. Pengendalian gulma di KSB dilaksanakan dengan cara manual, kultur teknis, kimiawi, dan mekanis. Penting dilakukan pengawasan mengenai kondisi alat semprot agar penggunaan biaya pengendalian lebih efisien. Persentase tingkat penggunaan APD sebesar 58% dan tergolong rendah., Uncontrolled weeds in oil palm fields reduce yields so effective and efficient weed control is needed. The internship has a general objective to improve technical and managerial skills in oil palm cultivation activities and a specific objective to increase understanding in weed control in the Artificial Seed Garden, PT Inti Indosawit Subur, Riau. The internship was carried out at KSB, PT Inti Indosawit Subur, Pangkalan Kerinci, Pelalawan, Riau from January to May 2023. The methods used were direct (primary data) and indirect (secondary data). Observation of primary weed data with NJD showed that the dominant weed in the disk area, namely Eleusine indica, showed the highest SDR of 45,28% in TBM, 30,92% in young TM, and 27,14% in old TM. Centotheca lappacea had the highest SDR value in young TM at 35,42% and mature TM at 55,7%. Cyperus kyllingia had the highest SDR value in TBM at 46%, young TM at 50,05%, and mature TM at 27,29%. Asystasia gangetica had the highest SDR value in mature TM at 17,03%. Weed control in KSB is carried out by manual, technical culture, chemical, and mechanical means. It is important to monitor the condition of the spray equipment so that the use of control costs is more efficient. The percentage of PPE usage rate is 58% and is classified as low.
Keyword: gulma, teknik pengendalian, biaya, APD, weeds, control techniques, cost, PPE

Judul: Pengendalian Gulma Kelapa Sawit (Elaeis Guineensis Jacq.) Di Kebun Sei Air Hitam, Pt. Perdana Intisawit Perkasa I, Kab. Rokan Hulu, Riau
Abstrak: Magang ini dilakukan di Divisi 3 Kebun Sei Air Hitam (SAH) PT Perdana IntiSawit Perkasa I, First Resources Grup, Kab. Rokan Hulu, Riau mulai dari Februari 2012 sampai Mei 2012. Penulis berstatus sebagai karyawan harian lepas selama satu bulan, sebagai pendamping mandor selama satu bulan, dan sebagai pendamping asisten divisi selama satu bulan. Kegiatan magang ini bertujuan untuk memperluas pengetahuan dan keterampilan penulis tentang aspek teknis dan manajerial di perkebunan kelapa sawit terutama dalam kegiatan pengendalian gulma. Pengamatan yang dilakukan meliputi dominansi gulma: kerapatan, frekuensi, dan berat kering biomassa gulma; jenis dan dosis herbisida yang digunakan; dan kecepatan pertumbuhan kembali setelah aplikasi. Asystasia intrusa (Forssk.) Blume dan Centotheca lappacea (L.) Desv. merupakan gulma dominan di Kebun SAH. Pengendalian gulma dilakukan secara manual (babat dempes) dan kimia (campuran isopropilamina glifosat 0.16 L/ha dan metil metsulfuron dengan dosis 0.008 kg/ha). Secara umum, kegiatan pengendalian gulma di Kebun SAH sudah berjalan dengan baik, namun masih terdapat beberapa kendala di antaranya: kekurangan jumlah dan kualitas tenaga kerja, serta ketersediaan alat dan keterlambatan penyediaan dan penyaluran bahan.
Keyword: Kelapa sawit, gulma, dominansi, pengendalian

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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