Judul: Karakter Reproduktif Gandum (Triticum aestivum L.) Sensitif Suhu Tinggi pada Aplikasi Putresin di Dataran Sedang dan Tinggi
Abstrak: Wheat (Triticum aestivum L.) is originated from subtropic area. Cultivating wheat in Indonesia faces high temperature stress. Putrescine application may be used to overcome the problem. The objective of this research was to study the effect of putrescine and wheat genotype to the reproductive characters of wheat that were planted in medium (Cisarua) and high (Cipanas) altitudes. The experiment was a factorial experiment with two factors. The first factor was putrescine concentration with 3 levels i.e, 0.0, 1.25, and 2.5 mM. The second factor was three wheat genotypes consisted of Dewata, Munal, and S-03. Putrescine did not affect wheat growth and production. In Cipanas, wheat genotype also affected several reproductive characters, i.e: flowering age, the angle of inflorescence, harvesting time, length of panicle, number of spikelet, number of floret, number of empty floret, and weight of seed per panicle. In Cisarua, wheat genotype affected flowering age, the angle of inflorescence, harvesting time, length of panicle, number of spikelet, number of floret and number of empty floret per panicle. Genotype S-03 is the best genotype to be planted in Cipanas, whereas Dewata is the best genotype to be planted in Cisarua.
Keyword: Triticum aestivum L., sensitive temperature, putrescine, Character reproduktif

Judul: Karakter Reproduktif Gandum (Triticum aestivum L.) Toleran Suhu Tinggi di Dataran Tinggi dan Sedang
Abstrak: Wheat (T. aestivumL.) is a cereal crop and member of the family Gramineae originated from subtropic region. It is suggested that putrescine aplication may improve wheat growth in tropical environment indicating that wheat crop might be resistant to high temperature stress and also able to increase its production. This study aimed to observe the effect of putrescine treatment to the reproductive characters of three cultivated varieties of high temperature-tolerant wheat that were plantedin Cisarua 600 m asl and Cipanas 1100 m asl, West Java. This experiment was designed as a factorial experiment with 2 factors. The first factor was putrescine with three consentrations 0, 1.25, and 2.5 mM. The second factor was wheat varieties, SBR, ASTREB and Nias. Wheat varieties influenced plant height and some reproductive characters including flowering and harvesting age, panicle length, number of spikelet, number of floret, number of empty floret, and seed weight per panicle. Moreover, altitude affected the plant height and number of tillers, but it did not affect the reproductive characters. Reproductive characters did not respond to putrescien application. The three cultivated varieties are high temperature-tolerant, therefore the varieties can be grown in two planting location.
Keyword: Triticum aestivum L., tolerant temperature, wheat reproductive, Putrescine

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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