The three-dimensional stress-strain state of cross-ply reinforced shells of revolution when heated

The mechanical behaviour of cross-ply reinforced shells of revolution when they are non-axisymmetrically heated is considered in a three-dimensional formulation, and all the components of the stress-strain state are obtained in full. The method of finite elements is used for a numerical solution of the problem. The effects of anisotropy in a double-layer boroepoxide cylindrical shell under conditions of variable heating in a circumferential direction are investigated.     

An optical study of high-pressure water-jet dynamics

This paper considers the results of an optical study of high-speed fluid jets ejected from a nozzle at 400 MPa. The objective was to study two-phase flows under extreme conditions and to analyze the possibility of the optimization of the device design. The process of a high-speed water jet as it exits the focusing tube of the Flow WaterJet Mach3 abrasive cutting machine, along with its development, and the state of the stationary flow are considered. The shadow method was used to investigate the initial stage of high-speed water-jet formation, as well as the jet-head dynamics during the first 200–400 µs after ejection at 400 MPa. A Photron FASTCAM SA5 high-speed camera with a frame rate of one million shots per second and an exposure time of 1 [mu]s and a FLIR SC7000 infrared thermal camera with a frame rate of 400 shot/s and an exposure time of 1 ms were employed in order to study the jet-formation process. The spatiotemporal characteristics of the jet-development process were analyzed. The jet velocity and the starting jet head acceleration were measured by post-processing of digital images.     

Light scattering by molecular-organized films on the surface of polycrystalline gold

Specific features of the structure of self-assembled layers of dodecanthiol on the surface of polycrystalline films of gold are investigated with the aim of revealing the effect of the substrate relief on the lateral distribution and the predominant orientation of thiol molecules within the limits of the layer. The analysis of the angular dependence of quasi-elastically scattered light that takes into account the contributions of the geometric roughness of the surface and the inhomogeneity of the dielectric constant to scattering allowed us to establish the correlation in antiphase between the distribution of the thickness of the thiol coating and the height of the relief of the gold surface. The formation of a thiol layer on the surface of polycrystalline gold is a complex process including adsorption, local self-assembly, and a surface-induced distortion of the ordered structure in the regions of minima of the surface relief. The approach proposed here and based on the nondestructive analysis of thin organized coatings can be efficiently applied for the study of specific features of the topography and the prediction of chemical functionality of self-assembled molecular ensembles.     

The properties of the (H2O)6 water cluster that depend on its density during temperature transitions

Water clusters (H₂O)₆ are simulated by the Monte Carlo method with the Metropolis function at various temperatures (T ₁ = 273 K, T ₂ = 298 K, and T′₁= 373 K) and densities (ρ₁ = 0.9998 g/cm³, ρ₂ = 0.9167 g/cm³, and ρ₃ = 0.00059 g/cm³) of the system. It is established that the number of retained most probable configuration types at ρ₁ = 0.9998 g/cm³ during temperature transitions from T ₁ = 273 K to T ₂ = 298 K and from T′₁ = 373 K to T ₂ = 298 K is smaller than at ρ₃ = 0.00059 g/cm³. This result was acquired on the background of the following invariable parameters of the system with the same temperature transitions for each of three values of density: (i) the average number of retained most probable configuration types, (ii) the average fraction of weight coefficients of the most probable configuration types, and (iii) the average potential energy. The configuration type that was retained among the most probable configuration types of the system for all values of density (ρ₁ = 0.9998 g/cm², ρ₂ = 0.9167 g/cm³, and ρ₃ = 0.00059 g/cm³) of the system for temperature transitions from T ₁ = 273 K to T ₂ = 298 K and from T′₁ = 373 K to T ₂ = 298 K was also revealed.     

Synthesis and properties of pyrimidinylalkylsulfonamides 4. Reaction of the Na salt of p-toluenesulfonamide with mono-N-(ω-haloalkyl)uracils

Conclusions The direction of reaction and the composition and yields of products obtained by reaction of the Na salt of p-toluenesulfonamide with N-(-bromoalkyl)uracils depend primarily on the length of the alkyl chain in the latter: When the Na salt of p-toluenesulfonamide reacts with N-(-bromopropyl)-6-methyluracil, the latter undergoes intramolecular cyclization, whereas the Na salt of p-toluenesulfonamide undergoes intermolecular alkylation at the sulfonamide group on reaction with N-(-bromopentyl)-6-methyluracil. In analogous reactions, N-(-bromobutyl)uracils undergo both intramolecular cyclization, followed by opening of the oxazepine ring by nucleophilic reagents, and intermolecular alkylation.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 9, pp. 2079–2084, September, 1978.     

An investigation of the infrared spectra of melt water at room temperature

It was shown experimentally that the infrared spectra of melted and never-frozen distilled water differed at frequencies of 1640 and 2130 cm^?1. This is explained by the long relaxation of water molecules structures to an equilibrium state in melt water. It was suggested that near the frequency 2130 cm^?1 there was a bigger influence of dissolved gas relaxation on the value of the transmitted intensity of infrared radiation than near the 1640 cm^?1 line.