Judul: Respons Karakter Agronomis dan Fisiologis terhadap Cekaman UV-B pada Bawang Merah Varietas Lokananta.
Abstrak: Bawang merah merupakan komoditas yang populer di masyarakat sebagai bahan masakan. Bawang merah memiliki potensi ekonomis karena permintaannya yang tinggi. Budidaya bawang seringkali dihadapkan dengan cekaman biotik ataupun abiotik. Penyinaran UV-B bertujuan untuk menginduksi ketahanan melalui respons morfologis dan fisiologis. Penelitian dilaksanakan di Kebun Percobaan Leuwikopo pada Desember 2023 hingga Maret 2024. Faktor yang digunakan terdiri dari intensitas 1 dan 3 lampu serta durasi penyinaran 30 menit dan 150 menit. Perlakuan 0 menit dan 0 lampu digunakan sebagai control. Penyinaran UV-B tidak memberikan pengaruh yang nyata terhadap karakter tinggi tanaman dan jumlah daun serta komponen hasil (bobot umbi, diameter umbi, bobot basah dan bobot kering brangkasan). Kandungan fruktosa pada 4 Minggu Setelah Pindah (MSP) dan insidensi penyakit minggu ke-8 memberikan pengaruh nyata pada penggunaan 3 lampu. UV-B tidak memberikan pengaruh yang sangat nyata terhadap vegetatif dan komponen hasil bawang merah. Akan tetapi, penyinaran UV-B meningkatkan produktivitas dan menurunkan persentase jumlah tanaman yang terserang daripada kontrol., Shallots are a popular commodity in society as a cooking ingredient. Shallots have economic potential due to their high demand. Shallot cultivation often faces biotic and abiotic stresses. UV-B radiation aims to induce resistance through morphological and physiological responses. The research was conducted at the Leuwikopo Experimental Garden from December 2023 to March 2024. Factors included light intensity of 1 and 3 lamps and exposure durations of 30 minutes and 150 minutes. A treatment of 0 minutes and 0 lamps served as the control. UV-B radiation did not significantly affect plant height, leaf number, or yield components (bulb weight, bulb diameter, fresh weight, and dry weight of shoots). Fructose content at 4 Weeks After Transplanting (WAT) and disease incidence in the 8th week were significantly affected by the use of 3 lamps. UV-B did not show a very significant effect on the vegetative and yield components of shallots. However, UV-B radiation increased productivity and reduced the percentage of affected plants compared to the control.
Keyword: chlorophyll, climate change, fructose, glucose, productivity

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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