Judul: Etnobotani aren (Arenga pinnata (Wurmb) Merr.) di Masyarakat Kasepuhan Ciptagelar, Resort Gunung Koneng, Taman Nasional Gunung Halimun Salak
Abstrak: Aren (Arenga pinnata (Wurmb) Merr.) merupakan sumberdaya hutan yang banyak dimanfaatkan masyarakat Desa Sirnarasa dan menjadi salah satu komoditas yang diunggulkan di kawasan TNGHS. Pemanfaatan aren yang dilakukan masyarakat Desa Sirnarasa semakin berkurang dan didominasi oleh orangtua. Hal tersebut dikhawatirkan dapat menyebabkan tidak adanya keberlanjutan dalam pemanfaatan aren dan berujung pada hilangnya pengetahuan lokal. Penelitian ini bertujuan untuk mengidentifikasi pengetahuan lokal masyarakat terhadap pemanfaatan aren, mengidentifikasi proses pengolahan aren menjadi produk, serta mengidentifikasi regenerasi petani aren di Desa Sirnarasa. Metode yang digunakan adalah wawancara dengan sistem semi terstruktur menggunakan teknik purposive sampling terhadap 30 KK, observasi lapang, dan studi pustaka. Pembuatan gula aren dan kolang-kaling merupakan bentuk pemanfaatan yang dilakukan masyarakat Sirnarasa. Pengolahan aren masih dilakukan secara tradisional. Diperlukan kerjasama antara berbagai pihak dalam pemanfaatan aren agar dapat meningkatkan kesejahteraan petani aren serta meningkatkan ketertarikan kaum muda untuk ikut memanfaatkan aren. Kata kunci: aren, desa Sirnarasa, pengetahuan lokal, Sugar palm (Arenga pinnata (Wurmb) Merr.) is a forest resource that is widely used by the people of Sirnarasa village and is one of the leading commodities in the GHSNP area. The use of sugar palm in Sirnarasa village is decreasing and now is dominated by the elderly. It is feared this could lead to the absence of sustainability in the use of sugar palm and lead to the loss of local knowledge. This study aims to identify local knowledge of the community on the use of sugar palm, identify the process of processing sugar palm into products, and identify the regeneration of sugar palm farmers in Sirnarasa village. The method used is an interview with a semi-structured system using a purposive sampling technique of 30 families, field observations, and literature study. Making palm sugar and palm fruit is a community use in Sirnarasa. Cooperation between various parties is needed in the use of sugar palm in order to improve the welfare of sugar palm farmers and increase the interest of young people to participate in the use of sugar palm. Keywords: palm sugar, Sirnarasa village, local knowledge
Keyword: aren, etnobotani, Desa Sirnarasa

Judul: Palm Ethnobotany in Beruas Village Community, Simpang Katis District, Central Bangka Regency
Abstrak: Aren (Arenga pinnata Merr.) merupakan spesies palma multiguna yang tersebar hampir di seluruh kawasan Indonesia, salah satunya di Desa Beruas. Penelitian ini bertujuan untuk mengidentifikasi profil masyarakat, bentuk pemanfaatan, kearifan lokal, dan tumbuhan berguna yang berada di sekitar tegakan aren. Pengambilan data dilakukan menggunakan metode wawancara secara mendalam, observasi partisipatif, dan dokumentasi. Hasil penelitian menunjukan bahwa seluruh petani aren di Desa Beruas berjenis kelamin laki-laki dengan dominan usia 36-45 tahun (dewasa akhir, KU III). Masyarakat memanfaatkan aren sebagai bahan pangan seperti gula aren dan kolang-kaling serta sebagai kerajinan tangan seperti sapu ijuk. Masyarakat memiliki kearifan lokal dalam menentukan aren yang menghasilkan banyak air melalui morfologi aren. Petani aren juga menggunakan pengawet alami seperti akar ube-ube kuning dan daun karamuang untuk memperpanjang masa simpan air nira. Spesies tumbuhan berguna yang pada umumnya ditemukan pada kelekak yaitu durian, nangka, manggis, cempedak, karet, dan kelapa., Sugar palm (Arenga pinnata Merr.) is a multipurpose palm species that is spread almost throughout Indonesia, one of which is in Beruas Village and Teru Village. This research aims to identify community profiles, forms of use, local wisdom, and useful plants located around sugar palm stands. Data collection was carried out using in-depth interview methods, participant observation, and documentation. The research results show that all sugar palm farmers in Beruas Village and Teru Village are male with a dominant age of 36-45 years (late adulthood, KU III). People use sugar palm as a food ingredient such as palm sugar and palm fruit and as a handicraft such as palm fiber brooms. The community has local wisdom in determining palm trees that produce a lot of water through palm morphology. Sugar palm farmers also use natural preservatives such as yellow ube- ube roots and Karamuang leaves to extend the shelf life of palm juice. Useful plant species that are generally found in kelekak are durian, jackfruit, mangosteen, cempedak, rubber, and coconut.
Keyword: aren, Kearifan lokal, kelekak, pemanfaatan aren

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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