Structure and microstructure evolution of Al-Mg-Si alloy processed by equal-channel angular pressing

An ultrafine grained Al–Mg–Si alloy was prepared by severe plastic deformation using the equal-channel angular pressing (ECAP) method. Samples were ECAPed through a die with an inner angle of F = 90° and outer arc of curvature of ¿ = 37° from 1 to 12 ECAP passes at room temperature following route Bc. To analyze the evolution of the microstructure at increasing ECAP passes, X-ray diffraction and electron backscatter diffraction analyses were carried out. The results revealed two distinct processing regimes, namely (i) from 1 to 5 passes, the microstructure evolved from elongated grains and sub-grains to a rather equiaxed array of ultrafine grains and (ii) from 5 to 12 passes where no change in the morphology and average grain size was noticed. In the overall behavior, the boundary misorientation angle and the fraction of high-angle boundaries increase rapidly up to 5 passes and at a lower rate from 5 to 12 passes. The crystallite size decreased down to about 45 nm with the increase in deformation. The influence of deformation on precipitate evolution in the Al–Mg–Si alloy was also studied by differential scanning calorimetry. A significant decrease in the peak temperature associated to the 50% of recrystallization was observed at increasing ECAP passes.Peer ReviewedPreprin

Vascular Dysfunction Induced in Offspring by Maternal Dietary Fat Involves Altered Arterial Polyunsaturated Fatty Acid Biosynthesis

Nutrition during development affects risk of future cardiovascular disease. Relatively little is known about whether the amount and type of fat in the maternal diet affect vascular function in the offspring. To investigate this, pregnant and lactating rats were fed either 7%(w/w) or 21%(w/w) fat enriched in either18:2n-6, trans fatty acids, saturated fatty acids, or fish oil. Their offspring were fed 4%(w/w) soybean oil from weaning until day 77. Type and amount of maternal dietary fat altered acetylcholine (ACh)-mediated vaso-relaxation in offspring aortae and mesenteric arteries, contingent on sex. Amount, but not type, of maternal dietary fat altered phenylephrine (Pe)-induced vasoconstriction in these arteries. Maternal 21% fat diet decreased 20:4n-6 concentration in offspring aortae. We investigated the role of Δ6 and Δ5 desaturases, showing that their inhibition in aortae and mesenteric arteries reduced vasoconstriction, but not vaso-relaxation, and the synthesis of specific pro-constriction eicosanoids. Removal of the aortic endothelium did not alter the effect of inhibition of Δ6 and Δ5 desaturases on Pe-mediated vasoconstriction. Thus arterial smooth muscle 20:4n-6 biosynthesis de novo appears to be important for Pe-mediated vasoconstriction. Next we studied genes encoding these desaturases, finding that maternal 21% fat reduced Fads2 mRNA expression and increased Fads1 in offspring aortae, indicating dysregulation of 20:4n-6 biosynthesis. Methylation at CpG −394 bp 5′ to the Fads2 transcription start site predicted its expression. This locus was hypermethylated in offspring of dams fed 21% fat. Pe treatment of aortae for 10 minutes increased Fads2, but not Fads1, mRNA expression (76%; P<0.05). This suggests that Fads2 may be an immediate early gene in the response of aortae to Pe. Thus both amount and type of maternal dietary fat induce altered regulation of vascular tone in offspring though differential effects on vaso-relaxation, and persistent changes in vasoconstriction via epigenetic processes controlling arterial polyunsaturated fatty acid biosynthesis

International Consensus Statement on Rhinology and Allergy: Rhinosinusitis

Background: The 5 years since the publication of the first International Consensus Statement on Allergy and Rhinology: Rhinosinusitis (ICAR‐RS) has witnessed foundational progress in our understanding and treatment of rhinologic disease. These advances are reflected within the more than 40 new topics covered within the ICAR‐RS‐2021 as well as updates to the original 140 topics. This executive summary consolidates the evidence‐based findings of the document. Methods: ICAR‐RS presents over 180 topics in the forms of evidence‐based reviews with recommendations (EBRRs), evidence‐based reviews, and literature reviews. The highest grade structured recommendations of the EBRR sections are summarized in this executive summary. Results: ICAR‐RS‐2021 covers 22 topics regarding the medical management of RS, which are grade A/B and are presented in the executive summary. Additionally, 4 topics regarding the surgical management of RS are grade A/B and are presented in the executive summary. Finally, a comprehensive evidence‐based management algorithm is provided. Conclusion: This ICAR‐RS‐2021 executive summary provides a compilation of the evidence‐based recommendations for medical and surgical treatment of the most common forms of RS

Search for gravitational waves associated with gamma-ray bursts detected by Fermi and Swift during the LIGO–Virgo run O3b

We search for gravitational-wave signals associated with gamma-ray bursts (GRBs) detected by the Fermi and Swift satellites during the second half of the third observing run of Advanced LIGO and Advanced Virgo (2019 November 1 15:00 UTC–2020 March 27 17:00 UTC). We conduct two independent searches: a generic gravitational-wave transients search to analyze 86 GRBs and an analysis to target binary mergers with at least one neutron star as short GRB progenitors for 17 events. We find no significant evidence for gravitational-wave signals associated with any of these GRBs. A weighted binomial test of the combined results finds no evidence for subthreshold gravitational-wave signals associated with this GRB ensemble either. We use several source types and signal morphologies during the searches, resulting in lower bounds on the estimated distance to each GRB. Finally, we constrain the population of low-luminosity short GRBs using results from the first to the third observing runs of Advanced LIGO and Advanced Virgo. The resulting population is in accordance with the local binary neutron star merger rate

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Not AvailableThis study was carried out to investigate the effect of supplementation of three selected tanniniferous tropical tree leaves of Ficus benghalensis, Artocarpus heterophyllus and Azadirachta indica on enteric methane emission, rumen fermentation characteristics and protozoal population in 20 native Indian adult male sheep (Mandya). The experiment was conducted in randomized block design with four treatments of five animals each. The sheep in control group (CON) were fed on complete feed block (CFB) comprising finger millet straw and concentrate in the ratio of 60:40 (DM basis) without any inclusion of tropical tree leaves. Sheep in three test groups i.e. FIC, ART and AZA were also fed complete feed block prepared from finger millet straw and concentrate in the same ratio (60:40) as control, but wheat bran in concentrate mixture of test groups was partially replaced (10 parts w/w) with selected tanniniferous tropical tree leaves of Ficus benghalensis, Artocarpus heterophyllus and Azadirachta indica, respectively. The condensed tannin intake in sheep between 7.15 and 10.8 g/kg dry matter intake via selected tanniniferous tropical tree leaves did not influence dry matter and digestibility. About 20–26% reduction (p<0.05) in enteric methane emission is achievable simply through the supplementation of selected tree leaves in straw based diet. The reduction in protozoal numbers (p<0.05) due to selected tropical leaves supplementation appeared as primary cause for the reduction in enteric methane emission. The study confirmed that entodinimorphs protozoa are more vulnerable to the condensed tannin supplementation. The study established that significant reduction in methane emission is feasible without affecting feed fermentation characteristics. However, studies in large productive (growing, lactating) ruminants are warranted in order to explore the persistency of ameliorative effect in long term and improvement in productive performance thereof.Not Availabl

Study of Nickel Silicide Formation and Associated Fill-Factor Loss Analysis for Silicon Solar Cells With Plated Ni-Cu Based Metallization

In this study, the impact of impurities incorporated into plated nickel seed layer on silicide formation and the influence of annealing temperature on the fill-factor (FF) loss of solar cells with Ni-Cu contacts is investigated. The silicide growth of electro-less plated nickel seed layer is significantly retarded compared with literature data on physical-vapor-deposition (PVD)-based nickel annealed at 550 degrees C. X-ray photoelectron spectroscopy and X-ray diffraction reveal the presence of SiO2 at the Ni-Si interface and the formation of nickel phosphides in addition to nickel silicide. The retardation in silicide growth is attributed to the presence of (111) planes after the texturing process and contaminants in the seed layer. Varying the annealing temperature of fabricated cells from 350 degrees C to 425 degrees C led to a decrease in the average FF from 79.3% to 77.5%. The loss analysis is based on Suns-V-oc measurements, illuminated current-voltage parameters, and dark current-voltage curve fitting based on a three-diode model. It reveals that the FF loss is dominated by increased junction recombination, whereas losses due to third-diode component become significant for annealing at 400 degrees C and higher temperatures. The results highlight the need to carefully tune the seed layer annealing parameters to the interface conditions and junction depth of solar cells