Judul: Pengaruh perlakuan iradiasi sinar gamma terhadap beberapa patogen terbawa umbi bawang merah
Abstrak: Indonesia is known as shallot-producing countries, but also imported shallot in a large numbers. The high rate of import may increase the risk of entry and spread of quarantine pests from the country of origin into the territory of Indonesia. Some of those quarantine pests are Cercospora duddiae, Pseudomonas syringae pv. syringae and Erwinia carotovora subsp. atroseptica. Gamma irradiation (cobalt-60) is a developing technique of quarantine treatment for eliminating the quarantine pests. The aims of this study are to see the effectiveness of gamma irradiation for eliminating quarantine pests and its effect on tuber’s germination as well as marketable tubers, to determine the feasibility of gamma irradiation as one of quarantine treatment techniques. In this experiment, the quarantine pests were replaced with non quarantine pathogen as a model, which are C. personata, E. carotovora, and fluorescence Pseudomonads. Dose of 50 Gy shows its effectiveness in inhibiting the germination percentage of shallot up to 10.3% and increasing the percentage of marketable tubers during storage up to 8.7%. The effective doses to eliminate fluorescence Pseudomonads, C. personata, and E. carotovora were 1500 Gy, 2000 Gy, and more than 5000 Gy, respectively. But those doses, caused more than 80% un-marketable. Based on those data, gamma irradiation could not be recommended as a quarantine treatment for imported shallot.
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Judul: Effect of UV-B Induction on  Agronomic and Physiological Character Performance of Shallot Sanren F1  Variety
Abstrak: Bawang merah (Allium cepa L. var. aggregatum) merupakan salah satu komoditas pertanian populer yang memiliki nilai ekonomis tinggi. Dalam era perubahan iklim global, pemahaman potensi UV-B untuk pertanian menjadi semakin penting. Penelitian ini bertujuan mempelajari pengaruh induksi UV-B terhadap performa karakter agronomis dan fisiologis bawang merah varietas Sanren F1. Penelitian ini dilaksanakan Kebun Percobaan Leuwikopo dan Laboratorium Terpadu Seed Center Departemen Agronomi dan Hortikultura, Kampus IPB, Kabupaten Bogor. Waktu pelaksanaan penelitian dimulai dari bulan Desember 2023 sampai Maret 2024. Percobaan disusun menggunakan rancangan kelompok lengkap teracak (RKLT) faktorial dengan dua faktor. Faktor pertama adalah intensitas lampu UV-B dengan tiga taraf yaitu nol, satu, dan tiga lampu. Faktor kedua yaitu durasi penyinaran, terdiri atas tiga taraf yakni 0, 30, dan 150 menit. Hasil penelitian menunjukkan bahwa induksi UV-B berpengaruh nyata pada insidensi penyakit, diameter umbi, kadar glukosa, kadar klorofil a dan b. Induksi UV-B belum menunjukkan adanya pengaruh yang nyata terhadap tinggi tanaman, jumlah daun, bobot basah umbi, bobot basah dan kering hijauan, dan kadar fruktosa., Shallot (Allium cepa L. var. aggregatum) is a popular agricultural commodity with high economic value. In the era of global climate change, understanding the potential of UV-B for agriculture is becoming increasingly important. This research aims to study the effect of UV-B induction on the performance of agronomic and physiological characters responses of shallots variety Sanren F1. This research was conducted in Leuwikopo Experimental Garden and Seed Center Integrated Laboratory of the Department of Agronomy and Horticulture, IPB Campus, Bogor Regency. The research was conducted from December 2023 to March 2024. The experiment was arranged using a randomized block design (RBD) with two factors. The first factor was the intensity of UV-B lamps with three levels: zero, one, and three lamps. The second factor is the duration of irradiation, consisting of three levels, namely 0, 30, and 150 minutes. The results showed that UV-B induction only significantly affected disease incidence, tuber diameter, glucose content, chlorophyll a and b content. UV-B induction had no effect on plant height, number of leaves, tuber wet weight, stalk wet and dry weights, and fructose content.
Keyword: UV-B induction, production, physiology, shallot, Induksi UV-B, Produksi, Fisiologi, Bawang merah

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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