Effect of reinforcement on mechanical characteristics of A356 alloy nanocomposites

© Published under licence by IOP Publishing Ltd. Nanocomposites with aluminum base reinforced with nanoparticles, have wide application in many industries, for example, aerospace, marine, automobile, due to its lightweight, high tensile strength and high wear resistance, etc. The study of the microstructure, mechanical and tribological properties of the nanocomposite is very important in order to reliably and optimally carry out the design of new materials. In this study for the mechanical characterization of the A356 composites with a ceramic particle reinforcements nanoindentation was performed. Nanoindentaion is largely used for the analysis of mechanical properties. The samples of the nanocomposites were developed using 0, 0.2, 0.3 and 0.5 wt.% SiC, with an average size of particles of about 50 nm, produced by a compocasting process with pre-processing mechanical alloying. Nanoindentation was carried out based on Berkovich's test method with the indenter in shape of three sided diamond pyramid. The nanocomposite testing showed that the nanocomposites containing 0.5 wt.% of the reinforcement have slightly higher tensile strength and a lower value of the elastic modulus compared to the aluminum alloy base

Antioxidative responses to seasonal changes and chemiluminescence assay of Astragalus onobrychis leaves extract

The aim of this study was to research the seasonal changes of antioxidant enzyme activity and total antioxidant capacity in leaves of Astragalus onobrychis L. subsp. chlorocarpus (Griseb.) S. Kozuharov et D.K. Pavlova. Leaves of A. onobrychis were collected during the different stages of growth and analyzed for antioxidant enzyme activity: superoxide dismutase, catalase, guaiacol peroxidase, glutathione peroxidase. Quantities of malonyldialdehyde, superoxide radicals, and hydroxyl radicals were measured as well as the content of soluble proteins. Furthermore, total antioxidant capacity was determined by the inhibition of chemiluminescence activity of blood phagocytes by leaf extracts. Stages of vegetation significantly affected the accumulation of superoxide radicals, but there were no significant differences in hydroxyl radical quantity and lipid peroxidation levels during vegetation. Soluble proteins vary greatly between different stages of growth. Seasonal changes were found to have an effect on enzymatic activities. During the spring season, guaiacol peroxidase showed the highest levels. Catalase and glutathione peroxidase increased their activities in summer, while, during the autumn season, superoxide dismutase showed maximum activity. On the basis of chemiluminescence assay, it can be concluded that leaf extract of A. onobrychis possesses a significant antioxidant capacity thus protecting plants during environmental stress

Chemical Diversity and Complexity of Scotch Whisky as Revealed by High-Resolution Mass Spectrometry

Scotch Whisky is an important product, both culturally and economically. Chemically, Scotch Whisky is a complex mixture, which comprises thousands of compounds, the nature of which are largely unknown. Here, we present a thorough overview of the chemistry of Scotch Whisky as observed by Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). Eighty-five whiskies, representing the majority of Scotch Whisky produced and sold, were analyzed by untargeted high-resolution mass spectrometry. Thousands of chemical formulae were assigned for each sample based on parts-per-billion mass accuracy of FT-ICR MS spectra. For the first time, isotopic fine structure analysis was used to confirm the assignment of high molecular weight CHOS species in Scotch Whisky. The assigned spectra were compared using a number of visualization techniques, including van Krevelen diagrams, double bond equivalence (DBE) plots, as well as heteroatomic compound class distributions. Additionally, multivariate analysis, including PCA and OPLS-DA, was used to interpret the data, with key compounds identified for discriminating between types of whisky (blend or malt) or maturation wood type. FT-ICR MS analysis of Scotch Whisky was shown to be of significant potential in further understanding of the complexity of mature spirit drinks and as a tool for investigating the chemistry of the maturation processes. [Figure: see text] ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s13361-016-1513-y) contains supplementary material, which is available to authorized users

Targeted plant improvement through genome editing: from laboratory to field

This review illustrates how far we have come since the emergence of GE technologies and how they could be applied to obtain superior and sustainable crop production. The main challenges of today's agriculture are maintaining and raising productivity, reducing its negative impact on the environment, and adapting to climate change. Efficient plant breeding can generate elite varieties that will rapidly replace obsolete ones and address ongoing challenges in an efficient and sustainable manner. Site-specific genome editing in plants is a rapidly evolving field with tangible results. The technology is equipped with a powerful toolbox of molecular scissors to cut DNA at a pre-determined site with different efficiencies for designing an approach that best suits the objectives of each plant breeding strategy. Genome editing (GE) not only revolutionizes plant biology, but provides the means to solve challenges related to plant architecture, food security, nutrient content, adaptation to the environment, resistance to diseases and production of plant-based materials. This review illustrates how far we have come since the emergence of these technologies and how these technologies could be applied to obtain superior, safe and sustainable crop production. Synergies of genome editing with other technological platforms that are gaining significance in plants lead to an exciting new, post-genomic era for plant research and production. In previous months, we have seen what global changes might arise from one new virus, reminding us of what drastic effects such events could have on food production. This demonstrates how important science, technology, and tools are to meet the current time and the future. Plant GE can make a real difference to future sustainable food production to the benefit of both mankind and our environment.European Cooperation in Science and Technology (COST) CA18111info:eu-repo/semantics/publishedVersio

BacHBerry: BACterial Hosts for production of Bioactive phenolics from bERRY fruits

BACterial Hosts for production of Bioactive phenolics from bERRY fruits (BacHBerry) was a 3-year project funded by the Seventh Framework Programme (FP7) of the European Union that ran between November 2013 and October 2016. The overall aim of the project was to establish a sustainable and economically-feasible strategy for the production of novel high-value phenolic compounds isolated from berry fruits using bacterial platforms. The project aimed at covering all stages of the discovery and pre-commercialization process, including berry collection, screening and characterization of their bioactive components, identification and functional characterization of the corresponding biosynthetic pathways, and construction of Gram-positive bacterial cell factories producing phenolic compounds. Further activities included optimization of polyphenol extraction methods from bacterial cultures, scale-up of production by fermentation up to pilot scale, as well as societal and economic analyses of the processes. This review article summarizes some of the key findings obtained throughout the duration of the project

Circularly Polarized Laser Fields, with Different Z, Including Non-Zero Initial Momentum

In this paper, by estimating the influence of different atom charge Z to the transition rate in tunnel ionization of atoms in strong laser fields we are devoloping further the observations from our earlier work. That is in the process of tunnel ionization including non-zero momentum into calculation of the transition rate gives result in lower transition rates for ejecting electrons from atoms by low-frequency laser fields, indicating that much of the photons are engaged in transferring energy to the free electron and thus unable to contribute to the effect of ionization. This is a conclusion that needs further experimental testing, which would clarify the mechanisms of tunnel ionization

Influence of angles of fiber orientation on improving the characteristics of composite cardan shaft using factorial experiment

© 2018 Institute of Physics Publishing. All rights reserved. Composite shafts in compare with steel ones are characterized by lower weight, lower values of stress and deformation, extremely harmonic vibration damping and higher values of natural frequencies. The analysis of the optimal design of composite cardan shafts has shown that the load capacity of shaft is greatly influenced by type of material and the angle of orientation of the fibers. In this study the influence of the fiber orientation in layers of the composite laminar cardan shaft of truck on the angle of twist using a factorial experiment was analyzed. Analyzed shaft is composed of nine layers wherein the first layer is of aluminum, and the rest of carbon/epoxy composites with different angles of fiber orientation (-45°, 0°, 45° and 90°). By using the factorial experiment the optimal variant angles of fiber orientation is obtained and the effect of each layer on the angle of twist of drive shaft. The results obtained show that the factorial experiment could be applied on optimization of composite cardan shaft which influences on the improvement of the characteristics of the screw shaft