Judul: Penanganan Panen dan Pascapanen Teh Hitam CTC (Camellia sinensis (L.) O.Kuntze) di Kebun Rancabali PTPN VIII Bandung, Jawa Barat
Abstrak: Kegiatan magang dilaksanakan di Kebun Rancabali, PTPN VIII Bandung pada bulan Januari hingga Mei 2021. Kegiatan magang bertujuan untuk meningkatkan wawasan, keterampilan, pengalaman dan memahami proses kerja secara teknis di lapangan dan manajerial pada perkebunan teh, khususnya penanganan panen dan penanganan pascapanen untuk memperoleh mutu yang baik dan produktivitas yang tinggi. Metode yang digunakan pada kegiatan magang yaitu menggunakan metode langsung dan tidak langsung. Hasil magang menunjukkan bahwa isian dan penumpukan waring berpengaruh nyata terhadap penambahan kerusakan pucuk teh. Semakin jauh jarak tempuh truk maka semakin lama waktu yang ditempuh truk. Semakin banyak muatan truk maka semakin banyak juga waring yang dibawa. Kapasitas pemetik mesin, gunting, dan delay life mencapai 149,4 kg HOK¯1, 61 kg HOK¯1, dan 71,72 kg HOK¯1 serta tidak dipengaruhi oleh usia, lama pengalaman kerja, dan jenis kelamin. Tenaga petik gunting, mesin, dan delay life sebanyak 136, 128, dan 30 orang. Rata-rata analisis pucuk memenuhi syarat olah (MS) pada pemetikan mesin dan pemetikan gunting yaitu 51,2% dan 47,9%. Cara pemetikan berpengaruh nyata terhadap persentase MS pucuk. Selisih timbangan kebun dan pabrik yaitu 0,63%. Semakin tinggi analisis pucuk maka semakin sesuai nilai densitas dengan standar. Rata-rata nilai rendemen teh yaitu 23,46%., Internship activity was conducted at Rancabali Estate, PTPN VIII Bandung in January to May 2021. The purpose of internship are increase insight, skills, experience and understand technical and managerial work processes in tea plantations, especially harvest handling and post-harvest handling to obtain quality good and high productivity. The method used in the internship is using direct and indirect methods. The results of the internship showed that the filling and stacking of warings had a significant effect on the increase in damage of tea shoots. The farther the truck travels, the longer the truck travels. The more the truck load, the more waring it carries. Machine picking capacity, scissors, and delay life reached 149.4 kg HOK¯1, 61 kg HOK¯1, and 71.72 kg HOK¯1 and were not influenced by age, length of work experience, and gender. Scissors, machine, and delay life force were 136, 128, and 30 person. The average shoot analysis met the processing requirements (MS) for machine picking and scissor picking, is 51.2% and 47.9%, respectively. The way of picking has a significant effect on the percentage of shoot (MS). The difference between estate and factory scales is 0.63%. The higher the shoot analysis, the more appropriate the density value with the standard. The average value of tea yield is 23.46%
Keyword: harvesting facilities, processing, shoot damage, shoot transportation, shoot quality

Judul: Management of Plucking Tea Plants (Camellia sinensis (L.) O. Kuntze) Rancabali Plantation, PTPN VIII, Bandung, West Java
Abstrak: Pemetikan merupakan kegiatan pemanenan pucuk tanaman teh yang dilakukan secara manual maupun mekanis dan dapat mempengaruhi kualitas serta kuantitas pucuk. Kegiatan magang dilaksanakan pada bulan Januari-Mei 2021 di Kebun Rancabali, PT Perkebunan Nusantara VIII, Bandung, Jawa Barat. Kegiatan magang bertujuan mempelajari budidaya teh secara teknis dan manajemen, khususnya mengenai pengelolaan pemetikan teh untuk mendapatkan pucuk teh dengan mutu yang baik dan produksi yang tinggi. Metode yang dilaksanakan selama magang, yaitu bekerja secara langsung di lapangan pada berbagai level pekerja dengan aspek khusus pemetikan pucuk dan mengumpulkan data sekunder dari arsip kantor induk, kantor afdeling, dan studi pustaka. Hasil pengamatan tinggi bidang petik, diameter bidang petik, tebal daun pemeliharaan, dan potensi hasil pucuk menunjukkan semakin tua umur pangkas maka bidang petik akan semakin tinggi, bidang petik semakin lebar, tebal daun pemeliharaan semakin tipis, dan persentase pucuk peko menurun. Tinggi bidang petik dipengaruhi oleh kemiringan lahan, semakin curam maka tinggi bidang petik semakin pendek. Laju perkembangan pucuk semakin lambat seiring bertambahnya umur pangkas. Hanca petik mesin lebih tinggi dibandingkan gunting petik, dan pemetikan delay leaf. Gilir petik gunting dan delay leaf lebih cepat dibandingkan mesin. Tenaga pemetik di lapangan masih kurang jika dilihat dari hasil perhitungan untuk semua metode pemetikan. Pemetikan mesin menghasilkan mutu yang lebih baik dibandingkan gunting petik. Hasil analisis pucuk masih dibawah standart (38,94% dari standar 60%) memerlukan peningkatan mutu pucuk dengan memperhatikan teknis pemetikan. Kata Kunci: gilir petik, Plucking is an activity of harvesting tea plant shoots that is carried out manually or mechanically and can affect the quality and quantity of shoots. Internship activities carried out in January-May 2021 at Rancabali Plantation, PT Perkebunan Nusantara VIII, Bandung, West Java. The internship activity aims to learn tea cultivation technically and management, especially regarding the management of tea picking to get tea shoots with good quality and high production. The method implemented during the internship is working directly in the field on various worker level with special aspects on tea plucking and collecting secondary data from the archives of the main office, division office, and references. The results showed that the height of the plucking area, diameter of the plucking area, thickness of maintenance leaves, and shoot yield potential showed that the older of the pruning age having the higher of plant height, the wider of plucking field, the thinner of maintenance leaf, and the decrease in the percentage of active bud shoots. The height of the plucking field is influenced by the slope of the land, the steeper it is, the shorter the height of the plucking field. The rate of shoot development slows down as the plant ages. Plucking mechine output is higher than plucking scissors, and plucking leaf delay. Scissor plucking rotation and delay leaf are faster than that by machines. The plucking worker in the field is still less number than the calculation for all the plucking methods. Plucking by machine produces better quality than plucking scissors. The results of the shoot quality analysis still below the standard (38,94% of standard 60%) indicate require an increase in shoot quality by taking care the plucking management.
Keyword: plucking method, plucking rotation, shoot quality

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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