GmNAC5, a NAC Transcription Factor, Is a Transient Response Regulator Induced by Abiotic Stress in Soybean

GmNAC5 is a member of NAM subfamily belonging to NAC transcription factors in soybean (Glycine max (L.) Merr.). Studies on NAC transcription factors have shown that this family functioned in the regulation of shoot apical meristem (SAM), hormone signalling, and stress responses. In this study, we examined the expression levels of GmNAC5. GmNAC5 was highly expressed in the roots and immature seeds, especially strongly in immature seeds of 40 days after flowering. In addition, we found that GmNAC5 was induced by mechanical wounding, high salinity, and cold treatments but was not induced by abscisic acid (ABA). The subcellular localization assay suggested that GmNAC5 was targeted at nucleus. Together, it was suggested that GmNAC5 might be involved in seed development and abiotic stress responses in soybean

Numerical simulation of discharge plasma generation and nitriding the metals and alloys

This research provides the numerical simulation of the plasma generation in a hollow cathode as well as the diffusion of nitrogen atoms into the metal in the low-pressure glow discharge plasma. The characteristics of the gas discharge were obtained and the relation of the basic technological parameters and the structural and phase state of the nitrided material were defined. Authors provided the comparison of calculations with the experimental results of titanium nitriding by low-pressure glow discharge plasma in a hollow cathode

Flow noise prediction based on wavenumber-frequency spectrum of turbulent fluctuating pressure

[Objectives] According to the Lighthill acoustic analogy equation and its development theory, it is feasible to analyze the wavenumber-frequency spectrum of turbulent wall pressure fluctuations, then make it an acoustic source in order to predict flow noise. Moreover, the study of the wavenumber-frequency spectrum is useful for understanding the temporal and spatial characteristics of turbulent structures.[Methods] Taking the NACA 0012 airfoil, which was studied by Brooks, as an example, we employ the Large Eddy Simulation (LES)method to calculate the flow field and obtain a numerical solution of the wavenumber-frequency spectrum via the Fourier transform. On this basis, we take the wavenumber-frequency spectrum as an input condition for predicting the radiated noise using the acoustic analogue equation of the Goldstein version. At the same time, acoustic software is used to calculate the flow noise. Comparing these two sets of results with Brooks' empirical formula, the sound pressure level is found to be within the same order of magnitude.[Results] The results show that the spectrum on an airfoil surface with a small curvature change is comparable with the Corcos spectrum model on a flat plate, and their general characteristics are similar. Finally, we conclude that the forecast results of the method in this paper accord better with Brooks' experimental results at low and medium frequencies.[Conclusions] This shows that it is necessary to carry out the study of wavenumber-frequency spectra, and it is reasonable to make it the main sound source in order to predict flow noise produced at subsonic speed

Dissolution and precipitation of TiC particles and their distribution in a laser clad 30vol.-%TiC_p/Ni-alloy composite coating

A 30vol%TiCp/Ni-alloy composite material was clad on steel 1045 using a 2 kW laser. The clad layer of the coating presents TiC particles, primary γ-Ni dendrites and the eutectics of γ-Ni +(Cr, Fe)23C6 in the interdendritic regions. Depending mainly on their sizes. TiC particles can not only be trapped by the advancing solid/liquid interface and thus distribute within the γ-Ni dendrites, but also be pushed away by the interface into the interdendritic regions together with the eutectics. The morphology of TiC particles are closely related to their dissolution and precipitation behavior during laser cladding. The growing mechanism of TiC particles are as follows: (1) radiated or stepped lateral growth at the edges of original particles; (2) bridging growth of the particles in cluster; (3) faceted growth of newly independently nucleated TiC particles in the liquid phase and (4) precipitation of TiC in γ-Ni extended solid solution