Epitaxy is the growth of a thin film by attachment to an existing substrate in which the crystalline properties of the film are determined by those of the substrate. In heteroepitaxy, the substrate and film are of different materials, and the resulting mismatch between lattice constants can introduce stress into the system. We have developed an island dynamics model for epitaxial growth that is...

The analysis of the propagation phase plays a fundamental role in the assessment and forecasting of risks related to the occurrence of submerged and coastal landslides. At present there are few numerical models able to simulate the propagation of such a type of events. This paper presents fully 3D models and approaches developed by the authors and suitable for the simulation of both completely ...

Mathematical studies of drug induced geometric visual hallucinations include three components: a model that abstracts the structure of the primary visual cortex V1; a mathematical procedure for finding geometric patterns as solutions to the cortical models; and a method for interpreting these patterns as visual hallucinations. In this note we survey the symmetry based ways in which geometric vi...

the ability of the present semiempirical quantum mechanics methods are surveyed for reproducing the transannular interaction in the bifunctional n-phenyl-5-azocanones. the am1 method is the best with the order of reliability being am1, pm3, mndo and mindo/3. am1 calculations were then carried out for quantification of transannular interaction. the n(o) ionization potential has been used for thi...

The formation constants of the species formed in the systems fr + glycine + dioxovanadium(V) + and H+ + glycine have been determined in aqueous solutions of methanol at 25 °C and constant ionicstrength, using spectrophotometric and potentiometric techniques. It was shown thatdioxovanadium(V) forms two mononuclear 1 : land 1:2 complexes with glycine. The formationconstants in various media were ...

The interactions between an anionic dye, Acid Green 25 AG and the two cationic surfactants tetradecyltrimethylammonium bromide TTAB, and hexadecyltrimethylammonium bromide CTAB in aqueous solutions far below the CMC are studied using the conductometric method at different temperature. The equilibrium constants and other thermodynamic functions for the process of dye-surfactant ion pair formatio...

The super-saturation condition has to be provided to form gas hydrates. Consequently, the prediction of the guest molecule fraction in the aqueous phase is crucial in the study of the gas hydrate kinetics. In the present work, several experiments were carried out in a semi-batch reactor in order to determine the mole fraction of methane and ethane during gas hydrates formation (growth stage...

The interaction of Congo Red CR with a series of Alkyltrimethylamoniumbromide CnTAB, N-hexadecylpyridinium bromide CPB and N-hexadecylpyridinium CPC were investigated using conductometry technique. It was observed that the formation of dye-surfactant ion pairs takes place at surfactant concentration far below the critical micelle concentration of the individual surfactants. Aggregation was refl...

hydrates are crystalline compounds similar to ice, with guest molecules like methane and ethane trapped inside cavities or cages formed by the hydrogen bounded framework of water molecules. these solid compounds give rise to problems in the natural gas oil industry because they can plug pipelines and process equipments. low dosage hydrate inhibitors are a recently developed hydrate control tech...