Judul: Tetrazolium Test Stain Pattern Criteria for Vigor  Detection Cowpea Seed (Vigna unguiculata)
Abstrak: Pengujian viabilitas dan vigor benih dengan uji tetrazolium merupakan salah satu metode uji cepat dengan mengevaluasi pola pewarnaan pada benih. Penelitian ini bertujuan menentukan pola pewarnaan benih kacang tunggak menggunakan uji tetrazolium untuk menentukan kriteria normal kuat, normal lemah, abnormal, dan mati. Penelitian terdiri atas dua percobaan. Percobaan pertama menggunakan rancangan kelompok lengkap teracak dengan faktor pertama adalah lama imbibisi (16 jam, 20 jam, 24 jam) dan faktor kedua adalah perendaman larutan tetrazolium (60 menit, 75 menit, 90 menit). Percobaan kedua menggunakan rancangan kelompok lengkap teracak dengan satu faktor yaitu empat taraf viabilitas. Percobaan pertama menghasilkan waktu imbibisi selama 20 jam dan perendaman tetrazolium selama 75 menit sebagai waktu yang optimal untuk benih kacang tunggak. Percobaan kedua menghasilkan 20 pola pewarnaan yang dikelompokkan menjadi 4 kelompok, yaitu normal kuat 1 pola, normal lemah 4 pola, abnormal 5 pola, dan mati 10 pola. Nilai koefisien korelasi (r) tertinggi pada tolok ukur kecepatan tumbuh dengan normal kuat sebesar r = 0,78. Tolok ukur indeks vigor menunjukkan keeratan nyata dan tolok ukur kecepatan tumbuh menunjukkan keeratan yang sangat nyata dengan normal kuat. Pola pewarnaan yang diperoleh dapat digunakan untuk pendeteksian vigor benih kacang tunggak., Testing the viability and vigor of seeds with the tetrazolium test is one of the rapid test methods for evaluating staining patterns in seeds. This study aims to determine the coloring pattern of cowpea seeds using the tetrazolium test to determine the criteria of high vigor seedling, low vigor seedling, abnormal, and dead seed. The study consisted of two experiments. The first experiment used a randomized complete group design with the first factor being the length of imbibition (16 hours, 20 hours, 24 hours) and the second was soaking the tetrazolium solution (60 minutes, 75 minutes, 90 minutes). The second experiment used a randomized complete group design with one factor of four levels of viability. The first experiment resulted in an imbibition time of 20 hours and a tetrazolium soaking of 75 minutes as the optimal time for cowpea seeds. The second experiment produced 20 coloring patterns grouped into 4 groups, high vigor seedling 1 pattern, low vigor seedling 4 patterns, abnormal 5 patterns, and dead 10 patterns. The highest correlation coefficient (r) in the seed growth speed with high vigor seedlings is r = 0.78. The percentage of index vigor shows real closeness and the percentage of seed growth speed shows very real closeness with high vigor seedlings. The obtained staining pattern can be used for the vigor detection of cowpea seeds.
Keyword: mutu fisiologis, normal kuat, normal lemah, uji cepat

Judul: Staining Pattern on Tetrazolium Test of Sesame Seed (Sesamum indicum L.) for Viability and Vigor Detection
Abstrak: Penelitian pola pewarnaan pada uji tetrazolium benih wijen yang sudah dilakukan terbatas pada kriteria viabel dan non viabel. Uji tetrazolium untuk deteksi vigor benih wijen saat ini belum dilakukan. Penelitian ini bertujuan menentukan pola-pola pewarnaan struktur internal benih wijen pada uji tetrazolium untuk menduga benih akan berkecambah dengan kriteria normal kuat, normal lemah, abnormal, dan mati dalam mendeteksi vigor benih. Penelitian dilaksanakan pada bulan Oktober 2022 hingga Maret 2023 di Laboratorium Ilmu dan Teknologi Benih, Departemen Agronomi dan Hortikultura, Fakultas Pertanian, Institut Pertanian Bogor. Penelitian terdiri atas dua percobaan. Percobaan pertama menggunakan rancangan kelompok lengkap teracak dua faktor yaitu faktor pertama adalah lama imbibisi (15 jam, 17 jam, 19 jam) dan faktor kedua adalah perendaman larutan tetrazolium (5 jam, 6 jam, 7 jam). Percobaan kedua menggunakan rancangan kelompok lengkap teracak dengan satu faktor perlakuan yang terdiri atas lima tingkat viabilitas benih. Waktu yang optimal dalam uji tetrazolium adalah 15 jam imbibisi dengan akuades dan 5 jam perendaman dalam larutan 1% tetrazolium. Pengujian ini menghasilkan 17 pola pewarnaan yang dikelompokkan menjadi empat kelompok yaitu satu pola normal kuat (NK), lima pola normal lemah (NL), empat pola abnormal (Ab) dan tujuh pola mati (M). Nilai koefisien korelasi erat (r=0,843) dan sangat nyata (P-value < 0,01) diperoleh antara daya berkecambah dengan pola pewarnaan normal (NK+NL) pada uji tetrazolium. Nilai R2 antara daya berkecambah dengan pola pewarnaan normal sebesar 0,711. Pola pewarnaan yang dihasilkan dapat digunakan untuk menguji viabilitas benih yaitu daya berkecambah, namun belum dapat digunakan untuk menguji vigor benih wijen., Research on staining patterns in sesame seed tetrazolium tests that have been carried out is limited to viable and non-viable criteria. The tetrazolium test for vigor detection of sesame seeds has not currently been performed. This study aims to determine the staining patterns of the internal structure of sesame seeds in the tetrazolium test to suspect that seeds will germinate with normal strong, normal weak, abnormal, and dead criteria in detecting seed vigor. The research was conducted from October 2022 to March 2023 at the Seed Science and Technology Laboratory, Department of Agronomy and Horticulture, Faculty of Agriculture, Bogor Agricultural University. The study consisted of two experiments. The first trial used a two-factor randomized complete group design: the first factor was the length of imbibition (15 hours, 17 hours, 19 hours) and the second factor was the soaking of tetrazolium solution (5 hours, 6 hours, 7 hours). The second experiment used a randomized complete group design with one treatment factor consisting of five levels of seed viability. The optimal time in the tetrazolium test is 15 hours of imbibition with aqueous and 5 hours of immersion in 1% tetrazolium solution. This test produced 17 coloring patterns grouped into four groups, namely one high vigor pattern (NK), five low vigor patterns (NL), four abnormal patterns (Ab) and seven dead patterns (M). The value of the close correlation coefficient (r = 0.843) and very real (P-value < 0.01) was obtained between germination and normal staining pattern (NK + NL) in the tetrazolium test. The R2 value between germination and the normal staining pattern is 0.711. The
Keyword: germination test, low vigor, staining pattern

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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