Judul: Keragaan dan Keragaman Mutan Tanaman Ubi Kayu (Manihot esculenta Crantz.) Hasil Iradiasi Sinar Gamma Serta Pendugaan Heritabilitas
Abstrak: Cassava is a potential crop for food, industry (food and feed), and bioenergy if developed suit with their characteristics. This research intended to identify the second generation (M1V2) cassava mutants from gamma ray irradiation. The irradiated cassava varieties are Ratim, UJ-5, and Malang-4. The result show that mutant variability appears on mutants plant performance (plant height, plant branching, tubers weight, number of tubers and economic tubers, cortex thickness and tuber qualitative characters). Variability in each genotype also appears on the tuber performance in this generation. Broad sense heritability estimation on number of tubers, number of economic tubers and cortex thickness were classified as high score and can used as third generation mutant selection criteria. The shelf life of cassava tubers depends on postharvest physiology deterioration (PPD) and marked by changes in water content and tuber discoloration, PPD occurs in almost all mutant genotype samples stored up to 21 days.
Keyword: Bogor Agricultural University (IPB), storage root, mutant, characterization, M1V2 generation

Judul: Karakterisasi Morfologi dan Pertumbuhan Beberapa Genotipe Ubi Kayu (Manihot esculenta Crantz) Hasil Induksi Mutasi Menggunakan Iradiasi Sinar Gamma
Abstrak: This reseach aims to study the growth and variability of several cassava genotypes through mutation induction irradiation. Stem cutting of cassava were irradiated in PATIR-BATAN and planted in Cikabayan Experimental Field, IPB from May 2012 to April 2013. This research was arranged in randomized completely block design with two factor that was gamma ray irradiation rate. Gamma irradiation rate consisted of five levels i.e. 0, 15, 30, 45, and 60 gray (Gy), second faktor that diferent genotypes consisted of five genotypes i.e. Jame-jame, Ratim, UJ5, Malang 4, and Adira 4. Results showed irradiation resulted in 146 plant death when plant are 2 months after planting. Irradiation treatment resulted in reduced number of stomata and number of tubers several genotype. 15 gray irradiation dose treatment produces larger tubers and plant height than control treatment and 30 gray of radiation dose. Characterization result showed that irradiation treatment resulted in changes in several morphological characters cassava.
Keyword: mutations, morphology, genotypes, characterization, cassava

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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