The paper considers the Bayesian balance model, within which the weak convergence of the normalized integral balance index to the digamma distribution is proved. As an auxiliary result, a ...generalization of Renyi’s theorem for structural distributions with a scale parameter is proved.
The influence of microstructure evolution on the low-temperature superplasticity of ultrafine Ti--6Al--4V was established. For this purpose, the static and dynamic coarsening response and ...plastic-flow behavior of the alloy with a mean size of alpha (sub)grains and beta particles of 0.1-0.4 mu m were determined via a series of tension tests at temperatures between 450 and 700 degree C. Both static and dynamic coarsening exhibited diffusion-controlled (r 3-vs-time) kinetics. However, dynamic coarsening was approximately two orders of magnitude faster than the corresponding static behaviors due to enhanced diffusion through the deformed beta matrix. A total elongation of 1000% and strain-rate-sensitivity exponent m = 0.48 were obtained at 550 degree C and 2 10-4 s-1. Very limited cavitation was observed in the specimens after superplastic deformation under optimal conditions.
The Richtmyer-Meshkov instability developing on the interface between helium and argon gases hit by a propagating shock wave is simulated numerically. In contrast with conventional approach based on ...the Navier-Stokes equations, the simulation in the current paper is performed on the molecular level using the Direct Simulation Monte Carlo method. The data averaging over short time periods is employed to decrease statistical scattering. The instability development is successfully reproduced with relatively moderate computer resources used. The time evolution of the transmitted shock wave and contact surface velocities are retrieved from numerical data as well as the instability growth rates.
The paper discusses the de-noising method in a model with an additive Gaussian noise, based on the wavelet-vaguelette decomposition and thresholding of the vaguelette coefficients. For soft and hard ...thresholding procedures, we derive the values of the thresholds and estimate asymptotically optimal orders of the loss function based on the probabilities of errors in calculating decomposition coefficients.
The internal structure of two highly dissolved cuboid diamonds from placers of the Krasnovishersk region (the Urals) has been studied. This internal structure has been visualized both from the ...crystal surface and on the plane-parallel polished plate. Sectorial inhomogeneities have been revealed: areas as three rays emanating from one point in the general space of the growth pyramid of {100} faces. These areas belong to growth pyramids of {110} faces. Thus, growth layers of {110}, {100}, and {111} faces can coexist in one natural crystal.
The article presents the implementation of CFD/FEM approach for real oil tank of the gas turbine engine for the purposes of prediction of the component behavior under the local impact of a burner ...jet. The model takes into account heat and mass transfer problems as well as strength problems that are solved using a one way coupled fluid-structure interaction method. Results of the blind test simulation are compared and show good agreement with available experimental data.
Self-heating effect caused by internal friction is a meaningful problem in design and operation of cyclically loaded structural elements made of fiber-reinforced plastics. Vibrations of aerospace ...structures with large amplitudes and high frequencies, as well as accelerated mechanical testing can lead to an increase of the composite temperature, degradation of the mechanical properties and premature failure. This research aimed to study the kinetics of GFRP self-heating under reversed bending. A low-parameter analytical model was developed to describe the kinetics of composite self-heating under normal convective heat transfer. The original wedgeshaped specimen and the experimental setup were developed to verify the simulation results. Cyclic bending tests were carried out at the frequencies from 10 to 20 Hz and displacement amplitudes from 4 to 7 mm. The model proposed enables to predict the dependence of the maximum composite temperature on time, frequency, and amplitude with reasonable accuracy.
Apple clonal rootstocks are the basis of modern intensive horticulture, providing a rapid increase in yield and convenience of fruit trees cultivation. Production of clonal rootstocks under high ...humidity often causes powdery mildew infection caused by the pathogenic fungus Podosphaera leucotricha Salm., which significantly reduces the productivity of stoolbed. Growing powdery mildew resistant genotypes is the most appropriate way to combat this disease and allows reducing the use of fungicides. To accelerate the search for resistant forms, molecular markers associated with resistance genes have been developed. However, these markers have not been used to study clonal rootstocks. The aims of the work were the field assessment of powdery mildew resistance of apple clonal rootstocks from the collection of the Michurinsk State Agrarian University and the screening of the collection for Pl-1, Pl-2, Pl-w and Pl-d resistance genes. The results of a three-year field evaluation of powdery mildew resistance of 80 rootstocks allowed us to distinguish five main groups ranging from very low to highly resistant. A group of 57 accessions was classified as powdery mildew resistant. The search for resistance genes was performed using the AT20 SCAR (Pl-1 gene), OPU02 SCAR (Pl- 2 gene), EM DM01 (Pl-d gene), and EM M02 (Pl-w gene) markers. The Pl-d and Pl-1 genes identified in 33 (41.25 %) and 31 (38.75 %) accessions, respectively, were the most common in the collection. The Pl-w gene was detected only in two accessions. Identification of the Pl-2 gene with the OPU02 SCAR marker did not reveal a fragment of the expected size. Thirty accessions with different powdery mildew resistance scores had two genes, Pl-1 and Pl-d, and highly resistant forms G16 and 14-1 had a combination of the Pl-d and Pl-w genes. These accessions can be used as donors of powdery mildew resistance for breeding new apple clonal rootstocks.
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