Lifetime Distribution of Clusters in Binary Mixtures Involving Hydrogen Bonding Liquids

Hydrogen bonded liquids are associated liquids and tend to exhibit local inhomogeneity in the form of clusters and segregated sub-nano domains. It is an open question as to whether Hbonded clusters in pure water have common features with the water segregated pockets observed in various aqueous binary mixtures, such as water-alcohol mixtures, for example. In the present study, we demonstrate through classical molecular dynamics studies of the lifetime distributions of the hydrogen bonds in different types of binary mixtures, that these lifetimes exhibit the same universal features in the case of the pure liquids, independently of the species concentrations. The same types of three distinct lifetimes are observed, all of them in the sub picosecond regime. The primary lifetime concerns that of Hbonded dimers, and strongly depends on Hbonding criteria such as the bonding distance. The two others are independent of bonding criteria. The secondary lifetime concerns Hbonded cluster lifetimes, while the tertiary lifetime concerns the topology of these clusters, such as chains or globules, for example. This surprizing separation in three distinct lifetimes suggests the existence of associated three distinct kinetic mechanisms in the very short sub-picosecond time scales.

The stress-strain state of the tank on soil foundation with local inhomogeneity

This article aims to numerically investigate the stress-strain state of the tank at the appearance a local area of inhomogeneity in the soil foundation. We have established the size of the zone of influence of the inhomogeneity area of the base on the work of the tank wall. Also, we have formulated proposals to adjust the requirements of the Russian regulatory and technical documentation.

Stress-strain state of a soil array with a cylindrical cavity supported by a reinforcing ring

The article deals with the problem of calculating a stress-strain soil massif with a horizontal cylindrical cavity created by an explosion (for example, drilling and blasting method of penetration), in the presence of a reinforcing ring. The calculation takes into account the radial local inhomogeneity of the array near the cavity, due to the explosive effects. The problem is solved in a two-dimensional formulation (flat deformed state). The solution uses a numerical-analytical method that reduces the solution to a system of ordinary differential equations with variable coefficients.

Determination of local inhomogeneity of the medium from the natural frequencies of string oscillations

The paper considers the problem of determining the local inhomogeneity of the medium from the natural frequencies of string oscillation. The inhomogeneity is modeled in three sections: in the first and third sections medium is homogeneous, and on average section the elastic characteristics are modeled by a quadratic function. This model is implemented using the conjugation conditions at boundary between media. It is shown that to identify the center of an inhomogeneity and determine its size, two natural frequencies are enough, and in the case of rigid fixing of both ends of the string, the solution of the problem is dual. The problem is solved by expanding the fundamental system of solutions into a power series in the variables x and λ. The estimates of the error of the method are given.