Determination of trace impurities in nickel-based alloy using neutron activation analysis

A radiochemical neutron activation analysis procedure has been applied to investigate 40 major, minor, and trace impurities in nickel-based alloy. The extensive use of these alloys in the electronic industry, telecommunications, manufacturing of aircraft engine turbine blades and chemical equipments desires for their precise characterization. The concentration of nickel in the nickel-based alloy was found to be 56.8%, whereas Fe, Cr, Ca, Mg, Ce, Mn, Na and V were the major components of the alloy, which constituted to more than 26%. The rest of the elements was present in minor or trace levels. Most of the rare earth elements except Ce were also present in trace amounts. Neutron activation analysis technique was preferably used because of its good sensitivity and multielement determination capabilities for the characterization of high purity materials. The comparison of RNAA and INAA indicated improvement in the detection limits utilizing radiochemical separation procedures developed in the present work.     

Precision flavour physics and supersymmetry

We review the salient features of a comparative study of the profile of the CKM unitarity triangle, and the resulting CP-violating phases , β and γ in B decays, in the standard model and in several variants of the minimal supersymmetric standard model (MSSM), reported recently by us. These theories are characterized by a single phase in the quark flavour mixing matrix and give rise to well-defined contributions in the flavour-changing-neutral-current transitions in K and B decays. We analyse the supersymmetric contributions to the mass differences in the B_d⁰– and B_s⁰– systems, ΔM_d and ΔM_s, respectively, and to the CP-violating quantity || in K decays. Our analysis shows that the predicted ranges of β in the standard model and in MSSM models are very similar. However, precise measurements at B-factories and hadron machines may be able to distinguish these theories in terms of the other two CP-violating phases and γ.     

CoFe-LDH nanowire arrays on graphite felt: A high-performance oxygen evolution electrocatalyst in alkaline media

Developing non-noble-metal oxygen evolution reaction(OER) electrocatalysts with high performance is critical to electrocatalytic water splitting. In this work, we fabricated Co Fe-layered double hydroxide(LDH) nanowire arrays on graphite felt(Co Fe-LDH/GF) via a hydrothermal method. The Co Fe-LDH/GF, as a robust integrated 3 D OER anode, exhibits excellent catalytic activity with the need of low overpotential of 252 and 285 m V to drive current densities of 10 and 100 m A/cm2 in 1.0 mol/L KOH, r...     

Synthesis of hindered hydrazones and their reaction with thionyl chloride

Hydrazones 12a–c and ketazines 13a–c were prepared by the reaction of ketones 11a–c with hydrazine hydrate depending on the temperature and the reaction time. Some ketone (aryl)hydrazone derivatives 14a,c,e reacted with thionyl chloride to afford the chlorothiadiazoline derivatives 15a–c . Surprisingly, the chlorine atom in the latter compounds was found to undergo smooth nucleophilic substitution, and by boiling these compounds in absolute ethanol gave the corresponding ethoxythiadiazoline derivatives 16a–c . The structure of the ethoxythiadiazoline 16b was confirmed by single crystal X‐ray determination. © 2003 Wiley Periodicals, Inc. Heteroatom Chem 14:223–228, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10125     

Naturally Available Flavonoid Aglycones as Potential Antiviral Drug Candidates against SARS-CoV-2

Flavonoids are important secondary plant metabolites that have been studied for a long time for their therapeutic potential in inflammatory diseases because of their cytokine-modulatory effects. Five flavonoid aglycones were isolated and identified from the hydrolyzed aqueous methanol extracts of Anastatica hierochuntica L., Citrus reticulata Blanco, and Kickxia aegyptiaca (L.) Nabelek. They were identified as taxifolin (1), pectolinarigenin (2), tangeretin (3), gardenin B (4), and hispidulin (5). These structures were elucidated based on chromatographic and spectral analysis. In this study, molecular docking studies were carried out for the isolated and identified compounds against SARS-CoV-2 main protease (Mpro) compared to the co-crystallized inhibitor of SARS-CoV-2 Mpro (α-ketoamide inhibitor (KI), IC₅₀ = 66.72 µg/mL) as a reference standard. Moreover, in vitro screening against SARS-CoV-2 was evaluated. Compounds 2 and 3 showed the highest virus inhibition with IC₅₀ 12.4 and 2.5 µg/mL, respectively. Our findings recommend further advanced in vitro and in vivo studies of the examined isolated flavonoids, especially pectolinarigenin (2), tangeretin (3), and gardenin B (4), either alone or in combination with each other to identify a promising lead to target SARS-CoV-2 effectively. This is the first report of the activity of these compounds against SARS-CoV-2.     

Test of the des Cloiseaux Law by Membrane Osmometry on Pullulan

The des Cloiseaux law Π ∼︁ C^9/4 describing the scaling relation between osmotic pressure and concentration in semi‐dilute solutions of neutral polymers in athermal solvent (good solvent) was tested on pullulan, which is a linear polysaccharide, using membrane osmometry. The experimentally determined exponent is 2.2865 ± 0.026, which agrees well with this power law and disagrees with the theoretical value of 2 based on the mean field approximation.     

Buffalo Yogurt Fortified with Eucalyptus (Eucalyptus camaldulensis) and Myrrh (Commiphora Myrrha) Essential Oils: New Insights into the Functional Properties and Extended Shelf Life

Eucalyptus (Eucalyptus camaldulensis) and Myrrh (Commiphora Myrrha) essential oils (EOs) stand out for their benefits in terms of health and functionality. Buffalo set yogurt enriched with different concentrations of EOs (0.3, 0.6, and 0.9%) were investigated. The effects of addition on sensory, syneresis, antibacterial activity, and bioactive properties (total phenol content and antioxidant activity) of yogurt were studied. The most acceptable organoleptic properties of treated yogurt were those samples treated with Eucalyptus oil. The levels of syneresis were decreased by increasing the concentration of EOs. Moreover, the antioxidant activity, antibacterial activity, and total phenolic content were enhanced by increasing the concentration of EOs. Yogurt with 0.9% Eucalyptus oil showed the highest antioxidant activity and total phenolic content. The same concentration of Eucalyptus oil showed the highest antibacterial activity against S. typhimurium (the inhibition zone was 20.63 mm) then E. coli (the inhibition zone was 19.43 mm). On the other hand, the highest antibacterial effect against L. monocytogene was for Myrrh oil-enriched yogurt by 0.9% and the inhibition zone was 19.21 mm. The obtained results showed that Eucalyptus and Myrrh oils can be applied to yogurt to improve its beneficial properties in terms of physical characteristics and for human health due to their antioxidant activity and phenolic materials.