Judul: Development of Radicle Emergence Test Method as a Rapid Vigour Test for Rice (Oryza sativa L.) Seed Using Digital Image Processing
Abstrak: Penelitian ini bertujuan mengembangkan metode uji pemunculan radikula sebagai pengujian cepat vigor pada benih padi menggunakan pengolahan citra digital. Pengolahan citra digital dapat memproses gambar dua dimensi pengamatan kecambah benih ke dalam bentuk numerik (panjang) sehingga hasilnya dapat dianalisis dan dikorelasikan dengan parameter pengujian benih baku lainnya. Penelitian ini dilaksanakan pada bulan Desember 2020 hingga April 2021 di Laboratorium Teknologi Benih dan Kebun Percobaan Sawah Baru, Departemen Agronomi dan Hortikultura, Fakultas Pertanian, Institut Pertanian Bogor. Penelitian ini menggunakan 3 varietas padi tipe baru yaitu IPB 3S, IPB 5R, dan IPB 8G. Rancangan percobaan yang digunakan yaitu Rancangan Kelompok Lengkap Teracak (RKLT) satu faktor untuk pengujian di laboratorium maupun di lapangan. Hasil pengujian pemunculan radikula dengan citra digital dapat menduga nilai daya berkecambah, indeks vigor, dan daya tumbuh lapang dari nilai panjang radikula minimal 1 mm pada jam ke-40 dengan persamaan y = 0,8501x + 82,291 (DB), y = 0,5312x + 33,954 (IV), dan y = 0,5607x + 83,164 (DTL) serta nilai panjang radikula minimal 2 mm pada jam ke-40 dengan persamaan y = 0,959x + 82,956 (DB), y = 0,7951x + 33,781 (IV), dan y = 0,7623x + 83,213 (DTL) pada suhu pengecambahan 25±2o C. Pengujian rata-rata panjang radikula dan persentase RE berkorelasi positif sedang hingga kuat dengan beberapa tolok ukur pengujian daya berkecambah, indeks vigor, dan daya tumbuh lapang., This research aims to develop radicle emergence test method as a rapid vigour test for rice seed using digital image processing. Digital image processing can process two-dimensional images of seed germination into numerical form (length) so that the results can be analyzed and correlated with common seed testing parameters. This research was conducted from December 2020 to April 2021 at the Seed Technology Laboratory and Sawah Baru Teaching Farm, Department of Agronomy and Horticulture, Faculty of Agriculture, IPB University. This research used 3 new types of rice varieties: IPB 3S, IPB 5R, and IPB 8G. The experimental design used was a Completely Randomized Group Design (CRGD) with single factor for laboratory and field testing. The results showed radicle emergence test using image processing can estimate the value of germination (DB), vigour index (IV), and field growth capacity (DTL) from the value of the radicle length of at least 1 mm at the 40th hour with the equation y = 0.8501x + 82.291 (DB), y = 0.5312x + 33,954 (IV), and y = 0,5607x + 83,164 (DTL) and a minimum radicle length value of 2 mm at the 40th hour with the equation y = 0,959x + 82,956 (DB), y = 0,7951x + 33,781 (IV ), and y = 0.7623x + 83,213 (DTL) at a germination temperature of 25±2o C. The average radicle length and the percentage of RE have a moderate to strong positive correlation with several benchmarks for testing germination, vigor index, and field growth power.
Keyword: gambar dua dimensi, panjang kecambah, pemunculan radikula, periode pengecambahan (jam), vigor benih

Judul: Development of Radicle Emergence Test on  Soybean Seeds (Glycine max L.) using Digital Image Processing
Abstrak: Pengolahan citra digital merupakan suatu teknik yang dapat digunakan untuk mengidentifikasi mutu benih dalam waktu singkat. Penelitian ini bertujuan mengembangkan metode pengujian cepat vigor pada benih kedelai (Glycine maxL.) menggunakan metode pemunculan radikula atau radicle emergence (RE) dengan pengolahan citra digital. Penelitian ini menggunakan rancangan kelompok lengkap teracak dengan empat ulangan dan dikecambahkan pada suhu 25 ± 2 ºC. Pengambilan citra dilakukan setiap dua jam sekali dalam rentang waktu 36-54 jam setelah benih dikecambahkan. Penelitian ini dilakukan dengan mengamati jumlah benih yang memiliki panjang radikula = 2 mm. Data panjang radikula tersebut kemudian dianalisis korelasi dan regresi terhadap tolok ukur mutu fisiologis benih, antara lain daya berkecambah, indeks vigor, potensi tumbuh maksimum, kecepatan tumbuh, dan mean radicle emergence time (MRET). Penelitian yang dilakukan memperoleh hubungan korelasi kuat antara panjang radikula = 2 mm dengan tolok ukur indeks vigor, kecepatan tumbuh, dan MRET pada benih kontrol serta korelasi kuat pada tolok ukur daya berkecambah dan indeks vigor pada cekaman salinitas NaCl konsentrasi 0,35% dan 0,7%. Korelasi kuat antara panjang radikula = 2 mm dengan tolok ukur vigor benih lainnya pada waktu pengecambahan 44 jam., Digital image processing is a technique that can be used to identify seed quality in a short time. This research aims to develop a rapid vigor testing method for soybean (Glycine max L.) seeds using the radicle emergence (RE) method with digital image processing. This research used a randomized complete group design with one factor with four replications and germinated at 25 ± 2 ºC. Images were taken every two hours within 36-54 hours after the seeds were germinated. This research was conducted by observing the number of seeds that had radicle length = 2 mm. The radicle length data was then analyzed for correlation and regression against the benchmarks of seed physiological quality, including germination, vigor index, maximum growth potential, growth speed, and mean radicle emergence time (MRET). The research conducted obtained a strong correlation on the benchmarks of vigor index, growth speed, and MRET in control seeds and a strong correlation on the benchmarks of germination and vigor index under NaCl salinity stress concentrations of 0.35% and 0.7%. Strong correlation between radicle length = 2 mm and other seed vigor benchmarks at germination time of 44 hours.
Keyword: ImageJ, percentage of radicula growth amount, germination period, seed viability, seed 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.
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