Morphological characterization of natural orchids Dendrobium spp.

Dendrobium is characterized by long pseudobulbs or canes with soft leaves over the entire length, or in some species short or swollen pseudobulbs with two leathery leaves. The inflorescence is composed from dozens of flowers of different sizes and colors. This study aimed to identify the quantitative morphological character of five species of Dendrobium spp. namely D. mirbelianum, D. lamellatum from Java, D. anosmum from South Kalimantan, D. bracteosum from Papua, and D. purpureum from North Sumatera. The resulted dendrogram based on the similarity matrix were divided into two clusters, among the five species the value of similarity coefficient is 1.50. The first cluster is only composed from D. mirbelianum, the second cluster is D. lamellatum, D. purpureum, D. bracteosum, and D. anosmum which have more distant relationship with the other three orchids. Moreover, D. lamellatum and D. purpureum have the closest similarity coefficient with 0.81 value, which have bigger chance to use as the parents for hybridization. There are many Dendrobiums spp. distribution which based on the relationship area. In addition to quantitative properties, it also needs to be expanded to qualitative, anatomy, cytology, and also molecular characteristic to have more comprehensive data.

Molecular dynamic simulation of the molecular characteristic and mechanical property of methane hydrate/ water/ ice mixture

The microscopic molecular characteristic will impact on the mechanical property of hydrate. Thus, molecular dynamics simulation is employed to investigate the molecular characteristic and mechanical property of methane hydrate/ water/ ice mixture system. The brittle fracture occurred during the tensile deformation of the system. Besides, the maximum stress of the hydrate/ water/ ice mixture system is lower than that of intact hydrate system. The fracture strain of studied system is smaller than that of pure hydrate system. The order parameters F3 and F4 can be used for determining the fracture position of mixture system and the changing of micro configuration on the mixture interface.