First-principles prediction of half metallic-ferromagnetism in La0.25Sr0.75Sn0.4In0.25Ru0.35O3 and enhanced experimental electrical and magnetic behaviours.

A successful mechanochemical synthesis of a new nanoscale semi-conductive perovskite, La0.25Sr0.75Sn0.4In0.25Ru0.35O3 (LSSIRuO) was achieved through co-doping of SrSnO3. XRD and IR analyses confirmed that the sample crystallized in a pure perovskite GdFeO3 type structure (Pnma space group). Diffuse reflectance measurements revealed a direct band gap of 1.3 eV, which was significantly narrowed compared to that of SrSnO3 (4.1 eV). The investigation of DFT calculations into the sextenary systems La0.25Sr0.75[Sn0.4Ru0.35]In0.25O3 and La0.25Sr0.75[Sn0.5Ru0.25]In0.25O3 has revealed semiconductor behavior, very close to a semiconductor-semi metal transition. Importantly, Arrhenius-type charge transport was confirmed through a temperature-dependent conductivity study of the sample, showing good electrical conductivity of 3.6 S m-1 at 513 K with an activation energy of Ea = 0.19 eV. Furthermore, the compound exhibited ferromagnetic ordering at temperatures lower than 155 K, contrasting the diamagnetic behavior of SrSnO3. The narrower band gap value (1.3 eV) and improved electrical properties of LSSIRuO, in addition to its ferromagnetic characteristics, distinguish it as a promising candidate for applications in optoelectronics, as well as in memory and spintronic devices.

Insights into the Anticorrosion Performance of Solanum lyratum Leaf Extract for Copper in Sulfuric Acid Medium.

In this paper, Solanum lyratum leaves were prepared into a corrosion inhibitor by a pure water extraction method. As a natural plant, S. lyratum leaf extract as a corrosion inhibitor has green features. S. lyratum leaf extract (SLLE) can effectively inhibit the corrosion of Cu in H2SO4 solution. The protective effect on copper in 0.5 mol/L H2SO4 solution was studied by electrochemical measurement, Fourier transform infrared spectrometry (FTIR), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), atomic force microscopy (AFM), and theoretical calculation. These results showed that the maximum corrosion inhibition efficiency (η) of SLLE for copper obtained in the electrochemical measurement at different temperatures is more than 90%. The adsorption of SLLE on copper surfaces conforms to the Langmuir isotherm adsorption model. FTIR and XPS showed the bonding information. SEM and AFM proved that the SLLE can protect the copper from corrosion media. The interaction and inhibition mechanism between the SLLE and copper surface was further revealed at the molecular level by theoretical calculation.

Simultaneous synthesis of H2, O2, and N2 via an innovatory energy system in Coronavirus pandemic time: Design, techno-economic assessment, and optimization approaches.

In this work, an innovative integrated system that is incorporated from solid oxide electrolysis cells and an oxygen separator membrane is assessed and optimized from the techno-economic aspects to respond to oxygen, hydrogen, and nitrogen demands for hospitals and other health care applications. Besides, a parametric comparison is conducted to apprehend the weights of parameters changes on the performance of criteria. Relying on the assessments, from the hydrogen production of 1 kg/s, 23.19 kg/s of oxygen, and 50.22 kg/s of nitrogen are produced. The parametric study shows that by raising the working temperature of the electrolyzer, the cell voltage variation has descending trend and the power consumption of the system is decreased by 19%. Finally, the results of multi-criteria optimization on the Pareto front reveal that in the optimal case, the system payback period is attained at about 5.32 years and the exergy efficiency of 92.47%, which are improved 16.6% and 16.2% compared to the base case, sequentially. Consequently, this system is proposed to consider as a cost-effective and reliable option towards its vital and valuable productions, in the pandemic period and after's.

3-[1-(2-Hy-droxy-anilino)ethyl-idene]-3H-chromen-2,4-dione.

The title compound is a new amino-coumarin derivative, C17H13NO4, and was synthesized by the condensation of 2-amino-phenol and 3-acetyl-4-hy-droxy-coumarin. An intra-molecular N-H⋯O hydrogen bond generates an S(6) ring motif. In the crystal, the molecules are linked into chains extending in the [010] direction by O-H⋯O hydrogen bonds. There is also a π-π stacking inter-action between the bicyclic coumarin fragment and the phenol ring [centroid-centroid distance = 3.7510 (14) Å], and these ring systems form between them a dihedral angle of 53.3 (2)°. Intermolecular hydrogen bond C-H⋯O hydrogen bonding is also observed in the interconnection of the crystal packing.

Effects of waste glass and waste marble on mechanical and durability performance of concrete.

Industrial waste has been rapidly increased day by day because of the fast-growing population which results environmental pollutions. It has been recommended that the disposal of industrial waste would be greatly reduced if it could be incorporated in concrete production. In cement concrete technology, there are many possibilities to use waste materials either as cement replacement or aggregate in concrete production. Two major industrials waste are glass and marble waste. The basic objective of this investigation is to examine the characteristics of concrete waste glass (WG) as binding material in proportions 10%, 20% and 30% by weight of cement. Furthermore, to obtain high strength concrete, waste marble in proportion of 40%, 50% and 60% by weight cement as fine aggregate were used as a filler material to fill the voids between concrete ingredients. Fresh properties were evaluated through slump cone test while mechanical performance was evaluated through compressive strength and split tensile strength which were performed after 7 days, 28 days and 56 days curing. Results show that, workability of concrete decreased with incorporation of waste glass and marble waste. Furthermore, mechanical performance improved considerably up 20% and 50% substitution of waste glass and waste marble respectively. Statistical approach of Response Surface Methodology (RSM) was used optimize both waste materials in concrete. Results indicate better agreement between statistical and experimental results.

Structural, spectroscopic and first-principles studies of new aminocoumarin derivatives.

The new aminocoumarin derivatives 3-[1-(3-hydroxyanilino)ethylidene]-3H-chromene-2,4-dione, (1), 3-[1-(4-hydroxyanilino)ethylidene]-3H-chromene-2,4-dione, (2), and 3-[1-(2-hydroxyanilino)ethylidene]-3H-chromene-2,4-dione, (3), all C17H13NO4, were synthesized by reacting an equimolar amount of 3-acetyl-4-hydroxycoumarin and the corresponding aminophenol in absolute ethanol. Structural and spectroscopic analysis of these phases revealed that derivatives (1) and (2) are isomers of previously reported (3) [Brahmia et al. (2013). Acta Cryst. E69, o1296]. The crystal structures of meta derivative (1) and para derivative (2) were ab initio determined from powder X-ray diffraction data using the direct-space approach. Both (1) and (2) adopt the orthorhombic space group P212121. These isomers show hydrogen bonds and rich π-π stacking, together with π...H interactions, which are built by conjugated systems of coumarin and phenol rings. In the crystalline lattice, the packing of (1) and (3) are mainly stabilized through O-H...O hydrogen bonding between neighbouring coumarin molecules, while hydrogen bonds between coumarin and water molecules build the stable crystal structure of derivative (2). A big similarity in the skeletons of the IR spectra of these isomers was noticed. Derivative (2) exhibits two weak bands which were not present in the spectra of the other two derivatives, at 2370 and 2948 cm-1, which can be assigned to the O-H vibrations of the solvent (H2O) trapped in the structure of (2). These aminocoumarin derivatives display absorption maxima in the visible region, attributed to π-π delocalization involving the whole electronic system of the compounds with a considerable charge-transfer character originating from the aminophenyl ring and pointing towards the coumarin system which is characterized by a high electron-accepting character. Additionally, the isolated molecular ground-state geometries were optimized at the PBE0/TZP level and the electronic properties, molecular electrostatic potential and Hirshfeld charges were determined.

Mercerization effect on structure and electrical properties of cellulose: Development of a novel fast Na-ionic conductor.

Mercerized cellulose (alkali cellulose C6H10O5* NaOH) was obtained by treatment of cotton linters (cellulose) with aqueous sodium hydroxide. Cellulose and alkali-cellulose samples with relative density of 78% and 79% were obtained after sintering the material in air at optimal sintering temperatures of 423 K and 473 K, respectively. The electrical properties of the samples were studied by impedance spectroscopy in the frequency range from 13 MHz to 50 Hz at temperatures between 393 K and 493 K. The influence of cellulose mercerization on electrical properties of cotton linters was observed. The cellulose behaves like an electrical insulator. Contrariwise, the alkali-cellulose is a fast-ionic conductor with a conductivity value of σ473 K = 3.22 × 10-6 S cm-1 having activation energies of 0.49 eV and 0.68 eV at temperature range of 393 K-458 K and 459 K-500 K, respectively. The change of activation energy value has been discussed in relation to thermal stability.

Polymorphism in 3-acetyl-4-hydroxy-2H-chromen-2-one.

A new polymorph (denoted polymorph II) of 3-acetyl-4-hydroxy-2H-chromen-2-one, C11H8O4, was obtained unexpectedly during an attempt to recrystallize the compound from salt-melted ice, and the structure is compared with that of the original polymorph (denoted polymorph I) [Lyssenko & Antipin (2001). Russ. Chem. Bull. 50, 418-431]. Strong intramolecular O-H...O hydrogen bonds are observed equally in the two polymorphs [O...O = 2.4263 (13) Šin polymorph II and 2.442 (1) Šin polymorph I], with a slight delocalization of the hydroxy H atom towards the ketonic O atom in polymorph II [H...O = 1.32 (2) Šin polymorph II and 1.45 (3) Šin polymorph I]. In both crystal structures, the packing of the molecules is dominated and stabilized by weak intermolecular C-H...O hydrogen bonds. Additional π-π stacking interactions between the keto-enol hydrogen-bonded rings stabilize polymorph I [the centres are separated by 3.28 (1) Å], while polymorph II is stabilized by interactions between α-pyrone rings, which are parallel to one another and separated by 3.670 (5) Å.

Crystal structure of 3-(2,2-di-bromo-acet-yl)-4-hy-droxy-2H-chromen-2-one.

The title compound, C11H6Br2O4, is a new coumarin derivative obtained from the reaction of 3-acetyl-4-hy-droxy-2H-chromen-2-one with bromine in acetic acid. The hy-droxyl group in involved in an intra-molecular O-H⋯O hydrogen bond. In the crystal, π-π inter-actions between the rings of the bicycle [inter-centroid distances = 3.498 (2) and 3.539 (2) Å] pack mol-ecules into stacks along the b axis, and weak inter-molecular C-H⋯O hydrogen bonds further link these stacks into layers parallel to the ab plane.