A study on magnetoelastic properties of Tb3 (Fe28−xCox) V1.0 (x=0, 3, 6) compounds

In this work, The magnetoelastic properties of polycrystalline samples of Tb₃ (Fe_28−xCo_x) V_1.0 (x=0, 3, 6) intermetallic compounds are investigated by means of linear thermal expansion and magnetostriction measurements in the temperature range of 77–515 K under applied magnetic fields up to 1.5 T. The linear thermal expansion increases with the Co content. The well-defined anomalies observed in the linear thermal expansion coefficients for Tb₃ (Fe_28−xCo_x) V_1.0 (x=0, 3, 6) compounds are associated with the magnetic ordering temperature for x=0 and spin reorientation temperatures for x=3, 6. Below transition temperatures, the value of the longitudinal magnetostriction (λ_Pa) at 1.6 T increases with Co content.     

Nano silica extracted from horsetail plant as a natural silica support for the synthesis of H3PW12O40 immobilized on aminated magnetic nanoparticles (Fe3O4@SiO2-EP-NH-HPA): a novel and efficient heterogeneous nanocatalyst for the green one-pot synthesis of pyrano[2,3-c]pyrazole derivatives

Research on Chemical Intermediates - In this work, nanomesoporous silica has been prepared from horsetail (Equisetum arvense), which is a medicinal plant, with high surface area. This natural...     

Immobilization of lactate as an electroactive indicator on pencil graphite electrode for the development of a new electrochemical biosensor for the detection of lactate dehydrogenase

A biosensor was developed for the detection of lactate dehydrogenase (LDH) enzyme using a lactate modified pencil graphite electrode (PGE). The sensor relies on the immobilization of the lactate on PGE, and LDH detection is based on the decrease of lactate peak current following oxidation to pyruvate in the presence of LDH. Square wave voltammetric technique was used for the assay of signals in the range of ?0.6 to 0.8 V and a frequency of 25 Hz for the determination of LDH. The dependence of the response was investigated in terms of reaction time, washing time and LDH and NAD⁺ amounts. Also, the electrochemical behavior of LDH treatment on the lactate modified PGE was studied. The electrode showed good selectivity, repeatability and an operational stability of about 90% of its original response for two weeks. Moreover, the sensor displayed a linear response range from 0.36?C2.13 U ??l^?1 for LDH with a detection limit of 0.16 U ??l^?1. The response time of the LDH-treated lactate modified PGE was found to be 2 s. The relative standard deviation (RSD) obtained was 3.5% (for LDH 0.71 U ??l^?1 and n = 3).     

Polar/nonpolar gas transfer through PEO-based copolymers membranes

Two PEG-based copolymers containing two different chain extenders, as hard segments, were synthesized by 4,4′-methylenediphenyl diisocyanate (MDI). The chain extenders were 1,4-butane diol (BDO) and 1,2-ethane diamine (EDA). The application of the polyurethane (PU) and poly(urethane-urea)s (PUU)s synthesized polymers, which were characterized by Fourier transform infrared spectrometer (FTIR), differential scanning calorimetry (DSC) and atomic Force Microscopy (AFM), in the gas permeability was investigated. The obtained results indicated that by replacing the urea linkage in the polymers, the microphase separation of hard and soft segments increased. The synthesized PEG-based copolymers were semi-crystalline at room temperature. According to the DSC results, the crystallinity of the synthesized polyurethanes decreased as temperature increased. In addition, a reduction in mean surface roughness could be seen based AMF information. The gas (carbon dioxide and methane) separation properties of the polymers revealed that by replacing the urea linkage, the diffusivity, permeability and selectivity of the gases increased slightly.

The solubility and diffusivity of gases indicated he solubility domination of gas transport in these membranes. However, the sorption coefficient (S) of a particular gas was surprisingly constant for the two synthesized polymers. The CO₂ permeability increased with increasing feed pressure, while CH₄ permeability remained almost constant at both temperatures of 25°C and 35°C. The increase in temperature led to an increase in the permeability of the gases and a decrease in the gas selectivity for the both synthesized polyurethanes.     

Molecular dynamics simulations of the structure and transport properties of tetra-butylphosphonium amino acid ionic liquids

Systematic molecular dynamics simulations are used to study the structure, dynamics and transport properties of the ionic liquids composed of the tetra-butylphosphonium ([TBP](+), or [P(C(4)H(9))(4)](+)) cation with six amino acid ([AA](-)) anions. The structural features of these ionic liquids were characterized by calculating the partial site-site radial distribution functions, g(r), and computing the dihedral angle distribution of n-butyl side chains in the [TBP](+) cations. The dynamics of the ionic liquids are described by studying the velocity autocorrelation function (VACF) and the mean-square displacement (MSD) for the centers of mass of the ions at different temperatures. The ionic diffusion coefficients and the electrical conductivities were evaluated from both the Einstein and Green-Kubo methods. The cross-correlation terms in the electric-current autocorrelation functions, which are an indication of the ion pair correlations, are investigated. The cationic transference numbers were also estimated to study the contributions of the anions and cations to the transport of charge in these ionic liquids. We determined the role of the amino acid anion structures on the dynamical behavior and the transport coefficients of this family of ionic liquids. In general, the MSD and self-diffusion coefficients of the relatively heavier non-planar [TBP](+) cations are smaller than those of the lighter amino acid anions. Introducing polar functional groups (acid or amide) in the side chain of [AA](-) decreases the diffusion coefficient and electrical conductivity of AAILs. The major factors for determining the magnitude of the transport coefficients are the chemical functionality and the length of the alkyl side chain of the [AA](-) anion of these [TBP][AA] ionic liquids.     

Effect of “Magnetized Water” on Size of Nickel Oxide Nanoparticles and their Catalytic Properties in Co2 Reforming of Methane

Theoretical and Experimental Chemistry - It was shown that the particle size of NiO nanoparticles has been controlled through the homogeneous precipitation process by using “magnetized...     

Starlikeness and subordination properties of a linear operator

In this paper, we introduce a new class of p-valent analytic functions defined by using a linear operator L_k^α. For functions in this class H_k^α(p,λh) we estimate the coefficients. Furthermore, some subordination properties related to the operator L_k^α are also derived.     

IMMEDIATE AND HIGH YIELDING SOLVENT-FREE OXIDATION OF SILYL AND PYRANYL ETHERS TO THEIR CORRESPOUNDING CARBONYL COMPOUNDS WITH ZINC DICHROMATE TRIHYDRATE (ZnCr2O7·3H2O)

Zinc dichromate trihydrate (ZnCr₂O₇·3H₂O) is an efficient reagent for the immediate deprotection of aromatic and aliphatic silyl and pyranyl ethers into their corresponding carbonyl compounds in high yields at room temperature under solvent-free conditions.     

One‐pot Solvent Free Synthesis of Some Tert‐indolylmethane Amine Derivatives by Fe(HSO4)3 as a Recyclable Catalyst

Solvent‐free synthesis of 3‐substituted indole derivatives by a one‐pot three‐component coupling reaction between aldehyde, N‐alkyl aniline and indole by Fe(HSO₄)₃ catalyzed is described. The noticeable features of this protocol are the simplicity of the procedure, easy synthesized, recyclable and inexpensive catalyst, no organic solvent and high yields in relatively short reaction times.