Judul: Viabilitas dan Daya Simpan Benih Lobak (Raphanus sativus L.) Lokal dan Impor Setelah Disimpan pada Ruang Simpan Berbeda
Abstrak: The objective of this research was to study the viability local and imported radish seed after storage period and different room storage condition. This research was conducted at IPB Seed Science and Technology Laboratory for five months. This research used completely randomized design with two factors. The first factor is storage period consisting of 0, 2, 4, 6, 8, 10 and 12 weeks, and the second factor is the room storage condition, such as the room (27-30.7 oC) and the AC (18.7-27.9 oC) with four replicates, used local and imported radish seed. The results showed that local and imported radish seed still have a high viability after 12 weeks storage period, and the both of seeds could be stored in room or AC condition depend on the available of own room to maintain the viability still high during storage period. First and final count of the germination test should be performed on days 3 and 5.
Keyword: storage period, seed viability test, local seed, imported seeds

Judul: Determining Seed Storability of Mung Bean Seeds (Vigna radiata) Based on Seed Viability Before Storage
Abstrak: Kacang hijau (Vigna radiata) merupakan salah satu komoditas penting di Indonesia. Mutu benih kacang hijau yang sampai ke tangan petani, sangat menentukan keberhasilan produksi. Benih yang disimpan pada ruang terbuka akan mengalami penurunan viabilitas benih dengan cepat sehingga daya simpan benih perlu diketahui untuk memastikan ketersediaan benih yang bermutu. Penelitian ini bertujuan untuk menetapkan daya simpan benih kacang hijau dengan menggunakan suatu peubah viabilitas atau vigor. Penelitian dilaksanakan mulai dari Januari 2023 hingga Agustus 2023 di Laboratorium Penyimpanan dan Pengujian Mutu Benih, Laboratorium Biologi dan Biofisika Benih, serta Laboratorium Uji Mutu Fisiologis, Departemen Agronomi dan Hortikultura, Fakultas Pertanian, Institut Pertanian Bogor. Penelitian dilaksanakan selama 6 bulan periode simpan dengan menggunakan rancangan acak lengkap (RAL) faktor tunggal yang terdiri dari 10 lot berupa varietas yaitu Vima 1 (a), Vima 2, Vima 3 (a), Vima 4, Vima 5, Vimil 1, Vimil 2, Kutilang, Vima 1 (b) dan Vima 3 (b). Pengamatan sebelum simpan meliputi pengamatan uji daya hantar listrik (DHL), uji pemunculan radikula (RE), uji pengusangan cepat (AAT), indeks vigor (IV), dan kecepatan tumbuh (KCT). Pengamatan saat benih disimpan meliputi pengamatan pada kadar air (KA) dan daya berkecambah (DB) yang diuji setiap bulan. Hasil penelitian menunjukkan adanya penurunan viabilitas benih kacang hijau yang disimpan pada ruang simpan terbuka (suhu 27,329,5 oC dan RH 6173%) dan disimpan dalam kemasan plastik polypropylene 0,8 mm dengan kadar air awal 7,1510,01%. Penetapan daya simpan benih dapat dilakukan dengan menguji daya berkecambah benih kacang hijau sebelum benih disimpan (x) dengan persamaan y = 0,1950x - 13,05, untuk y = daya simpan (bulan). Metode ini dapat digunakan pada penyimpanan jangka pendek untuk tujuan komersial., Mung beans (Vigna radiata) are one of the important commodities in Indonesia. The quality of the mung bean seeds that reach the hands of farmers is crucial to the success of the harvest. Seeds stored in open spaces will experience rapid decrease in seed viability, so the storage capacity of seeds needs to be known to ensure the availability of quality seeds. This research aims to determine the storability of mung bean seeds using a viability or vigor variable. The research was carried out from January 2023 to August 2023 at the Seed Storage and Quality Testing Laboratory, Biology and Biophysics Seed Laboratory, and Physiological Quality Testing Laboratory, Department of Agronomy and Horticulture, IPB University. The research was carried out for 6 month storage period using a single factor Completely Randomized Design (CRD) consisting of 10 lots of the variety, namely Vima 1 (a), Vima 2, Vima 3 (a), Vima 4, Vima 5, Vimil 1, Vimil 2, Kutilang, Vima 1 (b), dan Vima 3 (b). Observations before storage included observations the electrical conductivity test, radicle emergence test (RE), accelerated aging test (AAT), vigor index, and growth rate. Observations when seeds were stored included observations on moisture content and germination capacity which were tested every month. The results showed a decrease in the viability of mung bean seeds stored in open storage (temperature 27.329.5 oC and RH 6173%) and stored in 0.8 mm polypropylene plastic packaging with an initial moisture content of 7.1510.01%. Determining seed storability can
Keyword: mung bean, seed storage period, viability, vigor

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.
Keyword: