Cold fast setting epoxy adhesive VK-93

A developed epoxy adhesive, which meets the requirements of the operational repair of aeronautical equipment, components, and aggregates, as well as repairs under field conditions, is presented. The adhesive combines rather high pot life (～40 min), which enables surfaces with large areas to be bonded, as well as high hardening velocity at normal temperature upon reaching the initial level of adhesive joints of no less than 7.0 MPa (after 5 h of hardening) and a maximal level of strength of no less than 17.5 MPa (after 24 h of hardening). These characteristics of the adhesive serve to substantially improve the technical and economic efficiency of bonding operations.     

Crystal structure and thermal stability of ammonium adipate (NH4)2C6H8O4

Scientific-Research Institute of Chemical Reagents and Ultrapure Chemical Substances. Translated from Zhurnal Strukturnoi Khimii, Vol. 31, No. 6, pp. 123–127, November–December, 1990     

ON AVOIDANCE ACTIVITIES IN FISHERY ENFORCEMENT MODELS

Compliance and enforcement in fisheries are important issues from an economic point of view since management measures are useless without a certain level of enforcement. These conclusions come from the well‐established theoretical literature on compliance and enforcement problems within fisheries and a common result is that, it is efficient to set fines as high as possible and monitoring as low as possible, when fines are costless and offenders are risk neutral. However, this result is sensitive to the assumption that fishermen cannot engage in avoidance activities, e.g., activities to reduce the likelihood of being detected when noncomplying. The paper presents a model of fisheries that allows the fishermen to engage in avoidance activities. The conclusions from the model are that, under certain circumstances, fines are costly transfers to society since they not only have a direct positive effect on the level of deterrence, but also an indirect negative effect in the form of increased avoidance activities to reduce the probability of detection. The paper contributes to the literature on avoidance activities by introducing the externality from the illegal behavior as an endogenous effect on other offenders. For an externality, that has an exogenous effect on other actors, Malik shows that fines are only costly transfers for conditional deterrence (when one actor is deterred while another actor is not). For fisheries, we show that fines are also costly transfers under no deterrence (when no agents are deterred).     

Conservation laws and exact solutions for nonlinear diffusion in anisotropic media

Conservation laws and exact solutions of nonlinear differential equations describing diffusion phenomena in anisotropic media with external sources are constructed. The construction is based on the method of nonlinear self-adjointness. Numerous exact solutions are obtained by using the recent method of conservation laws. These solutions are different from group invariant solutions and can be useful for investigating diffusion phenomena in complex media, e.g. in oil industry.     

Exact solutions of gasdynamic equations obtained by the method of conservation laws

In the present paper, the recent method of conservation laws for constructing exact solutions for systems of nonlinear partial differential equations is applied to the gasdynamic equations describing one-dimensional and three-dimensional polytropic flows. In the one-dimensional case singular solutions are constructed in closed forms. In the three-dimensional case several conservation laws are used simultaneously. It is shown that the method of conservation laws leads to particular solutions different from group invariant solutions.     

On the formation of low molecular weight hydrocarbons in liquid n-alkanes γ-radiolysis: The yields affected by free radical and electron scavengers

The data on radical and/or electron scavengers' effects on liquid n-alkanes fragmentation by γ-radiation are explained in terms of the decomposition of parent alkyl radicals, resulting at least partly from the process of ion-electron pair neutralization. It is suggested that the decomposition of excited parent radicals in nearly statistical amounts gives rise to practically all olefins with corresponding yields of shorter alkyl radicals (low molecular weight alkanes) and the mechanism of “molecular decomposition” of parent alkane to alkane+olefin does not contribute significantly in n- alkanes fragmentation.

Electron scavengers, like N₂O, decrease the yields of parent radicals decomposition products by about only 45%. A certain amount of short alkyl radicals, resulting from other processes is being scavenged in N₂O containing systems. Oxygen scavenges all the radicals complementary to olefins, both scavengeable and unscavengeable, and also radical fraction of another origin, inhibited in N₂O containing systems.     

Adhesives for aviation equipment

The properties of high-strength and high-elastic film adhesives, high-strength cold- and hot-setting adhesive pastes, adhesives intended for bonding of metals, different nonmetallic and composite materials are overviewed. The properties of self-adhesive materials of different grades used for temporary repair of airframe surfaces are also described.     

Influence of correlations on the trajectories of zeroes of the matrix elements for bound–bound and bound–free transitions in electron scattering

The topology of the trajectories of the zeroes of the electron scattering matrix elements has been obtained in the Born approximation. At small-momentum transfer, K the behaviour of the trajectories depends on the positions and the number of Cooper minima. We demonstrate strong correlation effects in this K area. At the high momentum, the positions of the zeroes depend only slightly on the energy transfer to the atomic electron, and correlation effects are not important.     

Intershell interaction in excited atom and ion photoionization

It is demonstrated, that the photoionization cross section of an excited electron in Cs atom isoelectronic sequence acquire additional structure if the virtual polarization of the core by the incident photon is taken into account.