Operators with normal Aluthge transforms

The main purpose of the Note is to show that if the second Aluthge transform of an invertible operator is normal, so it is its first Aluthge transform. This extends results due to Moslehian and Nabavi Sales [Some conditions implying normality of operators, C. R. Math. Acad. Sci. Paris, Ser. I 349 (2011) 251–254] and Rose and Spitkovsky [On the stabilization of the Aluthge sequence, International Journal of Information and Systems Sciences 4 (1) (2008) 178–189]. Also, the structure of an injective operator with normal Aluthge transform is studied.     

Single-Step Synthesis of SiO<Subscript>2</Subscript>–TiO<Subscript>2</Subscript> Hydrophobic Core–Shell Nanocomposite by Hydrothermal Method

The objective of this work is the synthesis and characterization of an appropriate hydrophobic nanoparticle as a collector for flotation of hematit in Gol-E-Gohar Iron Mine Iran. In this investigation, SiO₂–TiO₂ nanocomposites have been successfully synthesized by hydrothermal process. The morphology, structure, and composition of the as-synthesized nanostructures have been investigated by scanning electron microscopy and transmission electron microscopy. The ability of SiO₂–TiO₂ nanocomposite to facilitate the froth flotation of pyrite was correlated to the hydrophobicity of the nanoparticles. Furthermore, the efficiency of the mineral flotation process was evaluated in terms of final recovery and grade of S in Gol-e Gohar Iron Ore Complex, Sirjan, Iran.     

Conjugation of pectin biopolymer with Au-nanoparticles as a drug delivery system: Experimental and DFT studies

In the present study, pectin-coated gold nanoparticles (GNPs) were used as a candidate for curcumin drug delivery. The effect of the size of synthesized GNPs was examined, as an important factor on the yield of drug delivery. For this purpose, three different sizes of GNPs were first synthesized using a chemical method. The synthesized nanoparticles were then coated with pectin biopolymer. Finally, curcumin drug was loaded in a pectin@GNPs complex. Various methods such as UV–vis spectrophotometry, dynamic light scattering, scanning electron microscopy and Fourier-transform infrared spectroscopy were used to characterize the synthesized GNPs and pectin@GNPs. The encapsulation efficiency and the release percentage of the drug were calculated for two different pH values. Further, an antibacterial study was conducted. The results revealed that 100 nm GNPs had the highest encapsulation efficiency. An investigation of the release rate of curcumin drug at 37°C for 48 h indicated that the amount of drug released was higher in acidic pH than at pH 7.4 with a slow release rate. The electronic structure and the adsorption properties of pectin–GNPs complex were examined using the density functional theory method.     

Upper and lower bounds for the Hilbert–Schmidt norm of a potential operator

Archiv der Mathematik - We give upper and lower bounds for the Hilbert–Schmidt norm of logarithmic potential on a planar domain in terms of its area and inradius.     

CuO nanoparticles supported on three‐dimensional nitrogen‐doped graphene as a promising catalyst for thermal decomposition of ammonium perchlorate

In the present work, CuO nanoparticles grown on three‐dimensional nitrogen‐doped graphene‐based frameworks (CuO@3D‐(N)GFs) were synthesized using a two‐step method. After the synthesis of three‐dimensional nitrogen‐doped graphene, CuO nanoparticles were deposited on it, by adding cupric acetate followed by thermal treatment. Different analysis methods were used to characterize the products. The as‐prepared nanocomposite was used as a promising catalyst for thermal decomposition of ammonium perchlorate (AP) as one of the most common oxidizer in composite propellants. Differential scanning calorimetry (DSC) and thermogravimetry analysis (TGA) techniques were used to investigate the thermal decomposition of ammonium perchlorate. According to the DSC/TGA, high temperature decomposition of AP decreased to 111 °C in the presence of 4% CuO@3D‐(N)GFs and the total heat release (ΔH) from decomposition of AP increased to 1893 J g^?1 which is much more than 590 J g^?1 for pure AP.     

Ni@Pd nanoparticles supported on ionic liquid‐functionalized KCC‐1 as robust and recyclable nanocatalysts for cycloaddition of propargylic amines and CO2

Novel heterogeneous catalyst systems comprised of a fibrous nanosilica‐supported nano‐Ni@Pd‐based ionic liquid (KCC‐1/IL/Ni@Pd) are described for the cyclization of propargylic amines with CO₂ to provide 2‐oxazolidinones. KCC‐1 with high surface area was functionalized with IL acting as a robust anchor so that the nano‐Ni@Pd was well dispersed on the fibres of the KCC‐1 microspheres, without aggregation. Because of the amplification effect of IL, high loading capacities of the nanocatalysts were achieved. The reported synthesis includes several advantages like solvent‐free conditions, operational simplicity, short reaction times, environmentally benign reaction conditions, cost effectiveness, high atom economy and excellent yields, making it a genuinely green protocol.     

Metal organic framework–derived core-shell CuO@NiO nanosphares as hole transport material in perovskite solar cell

Journal of Solid State Electrochemistry - Cu-Ni bimetallic organic frameworks were synthesized by a facile and stepwise solvothermal method, utilizing metal organic framework as precursor....