Application of barycentric method for determination of free energy of liquid monodisperse system accomplishing diffusion

The barycentric method has been applied to determining the thermodynamic potential (the free energy) of a liquid rarefied monodisperse colloid system in which free unstationary diffusion under constant external conditions has been accomplished. Free energy at an arbitrary moment of time has been obtained as a function of horizontal mass center shift toward the cuvette cavity geometrical center of the liquid disperse system investigated. A very good coincidence between the numerical results from the proposed barycentric method and another classical thermodynamic method has been observed.     

Mixed Ligand Palladium(Ⅱ) Complex with NS-Bidentate S-Allyldithiocarbazate Schiff Base: Synthesis, Spectral Char-acterization, Crystal Structure and Decoding Intermolecular Interactions with Hirshfeld Surface Analysis

A new mixed ligand palladium(II) complex with bidentate NS‐donor chelate, [PdCl(PPh₃)L] (L: S‐allyl β‐N‐(benzylidene)dithiocarbazate), has been prepared and characterized using single crystal X‐ray diffraction and spectroscopic (electronic, IR, ¹H NMR and ¹³C NMR) techniques. The shorter Pd? P bond distance, 2.255(7) Å, than the sum of the single bond radii for palladium and phosphorus (2.41 Å), showed partial double bond character. Visualizing and exploring the crystal structure using Hirshfeld surface analysis showed the presence of π··· π, N··· π, C? H··· π, Cl···H and weak C? H···S interactions as most important intermolecular interactions in the crystal lattice, which are responsible to extension of the supramolecular network of the compound and stabilization of the crystal structure.     

Facile and green methodology for surface‐grafted Al2O3 nanoparticles with biocompatible molecules: preparation of the poly(vinyl alcohol)@poly(vinyl pyrrolidone) nanocomposites

The present work describes preparation of modified alumina with biocompatible, water soluble, and treating agents such as citric acid and ascorbic acid. Also, the influence of the modified nanoparticles (NPs) into the blend of poly(vinyl alcohol)@poly(vinyl pyrrolidone) (50/50) matrix was studied. At first, citric acid and ascorbic acid as environmental friendly agents were grafted on the surface of Al₂O₃ NPs. Then, nanocomposites (NCs) with different amounts of modified Al₂O₃ NPs were prepared via a simple ultrasonic method. The characterizations of the molecular structure of the NCs specified that chemical and physical interactions happened between inorganic and organic counterparts. The mutual effect of modified NPs into the polymer matrix was investigated on the structural, interfacial interaction, thermal stability, and optical properties. The results from morphological characterization confirmed changes in morphology of poly(vinyl alcohol) and poly(vinyl pyrrolidone) after loading NPs. Uniform dispersion of modified spherical Al₂O₃ NPs powders into the matrix of 50/50 polymers was detected by field emission scanning electron microscopy and energy‐dispersive X‐ray. Adding M‐NPs into the polymer matrix expressively improved the thermal stability of NCs. Peaks in ultraviolet–visible spectra were shifted to the higher absorption. Copyright © 2017 John Wiley & Sons, Ltd.     

Systematic Study of Two-Quasi-Particle Structure of Odd–Odd Thulium Nuclei

Physics of Atomic Nuclei - In this study, the nuclear structure properties of $${}^{160{-}166}$$ Tm isotopes with neutron numbers 91, 93, 95, and 97 were investigated using the projected shell...     

Preparation of an efficient catalyst through injection of CuI on modified poly (styrene-co-maleic anhydride) and theoretical investigation of the structural and electronic properties of catalyst

A novel polymer supported [poly (styrene-co-maleic imide) (SMI)]Cu(I) nano-particles was prepared via in situ reaction of 4-amino-5-methyl-4H-1,2,4-triazole-3-thione with [poly (styrene-co-maleic anhydride)] (SMA) along with immobilization of CuI. These nano-particles were fully characterized by using scanning electron microscopy (SEM), energy dispersive spectroscopy analysis, Xray (EDAX), inductively coupled plasma (ICP) analysis, ¹H NMR and FT-IR techniques. Moreover, the structural and electronic features of metal–ligand interactions in the complex model of polymer-supported copper nanocatalyst were assessed using density functional theory calculations. The catalytic activity of these supported Cu(I) nonoparticles was examined in one of the classiest name reaction so–called “click reaction” which is coined K. B Sharpless for the regioselective synthesis of 1,2,3-triazole derivatives using a multicomponent reaction (MCR) involving benzyl halides, sodium azide and terminal alkynes in water as a green solvent. This heterogeneous catalyst showed excellent catalytic activity and was separated by simple filtration and was used at least in five consecutive runs without a significant decrease in its activity.     

Investigation of Aqueous Diethanolamine Performance in Prediction of Hydrogen Sulfide and Carbonyl Sulfide Removal from Liquefied Propane

Journal of Solution Chemistry - Hydrogen sulfide and carbonyl sulfide represent undesirable impurities in a variety of industrial gas streams such as natural gas, liquefied natural gas and...     

Molecular theory of thermal conductivity of the Lennard-Jones fluid

In this paper the thermal conductivity of the Lennard-Jones fluid is calculated by applying the combination of the density-fluctuation theory, the modified free volume theory of diffusion, and the generic van der Waals equation of state. A Monte Carlo simulation method is used to compute the equilibrium pair-correlation function necessary for computing the mean free volume and the coefficient in the potential-energy and virial contributions to the thermal conductivity. The theoretical results are compared with our own molecular dynamics simulation results and with those reported in the literature. They agree in good accuracy over wide ranges of density and temperature examined in molecular dynamics simulations. Thus the combined theory represents a molecular theory of thermal conductivity of the Lennard-Jones fluid and by extension simple fluids, which enables us to compute the nonequilibrium quantity by means of the Monte Carlo simulations for the equilibrium pair-correlation function.     

Evaluation of Failure Behavior of Transversely Loaded Unidirectional Model Composites

A leading reason for the limited use of laminated composite materials in primary structural applications is that the failure initiates in the ply oriented transverse to the direction of the applied load at a much lower strain level than that which would cause the ultimate failure of the laminate. Previous studies indicate that transverse failure is manifested as either cavitation-induced failure of the matrix system or fiber-matrix debonding. The mechanism causing the failure initiation event is not decidedly known and depends on the local stress field of the constrained matrix that is a function of fiber spacing. In the present study a model composite system using a transparent matrix is employed in a cruciform-shaped specimen to evaluate the viability of several transverse failure theories. The cruciform-shaped specimen utilizes a low strain-to-failure 828/D230 RT cured epoxy and stainless steel wires arranged such that a fiber is placed at the intersection of face diagonals of four remaining fibers located at corners of a square. The transverse failure mechanism is observed in-situ via the reflected light method and recorded utilizing high resolution, high magnification microscope cameras. A parametric study is conducted using three dimensional finite element models to analyze the stress state in the cruciform specimen as a function of fiber spacing. The result of the 3-D FE models in conjunction with experimental observations are used to evaluate the transverse failure theories suggested in the literature. In addition this data will be used to develop a comprehensive failure criterion for transversely loaded multi-fiber composites that encompasses the dependence on fiber spacing.     

Synthesis,Characterization and Cytotoxic Activity of S-Benzyldithiocarbazate Schiff Bases Derived from 5-Fluoroisatin, 5-Chloroisatin, 5-Bromoisatin and Their Crystal Structures

Abstract  

Schiff bases were prepared from S-benzyldithiocarbazate with 5-fluro-, 5-chloro- and 5-bromoisatin. All are potential tridentate nitrogen, oxygen, sulfur donors. They were found to be selectively active against MCF-7 cell line (Human non-metastatic mammary gland adenocarcinoma cell line). The bromide and fluoride compounds were the most active with IC₅₀ values of 6.40 μM (2.6 μg/mL) and 9.26 μM (3.2 μg/mL) respectively while the chloride derivative was weakly active with an IC₅₀ value of 38.69 μM (14.0 μg/mL). The cytotoxic activity of the halo substituted isatins against the breast cancer cell lines tested is in the order of Br > F > Cl. Planarity of the isatin ring in the Schiff bases can be arranged in the following order SB5FISA > SB5ClISA > SB5BrISA while the perpendicularity of the benzyl ring towards the dithiocarbazate plane can be ordered as follows, SB5FISA > SB5BrISA > SB5ClISA.     

Equilibrium solubility of carbon dioxide in a 30 wt.% aqueous solution of 2-((2-aminoethyl)amino)ethanol at pressures between atmospheric and 4400 kPa: An experimental and modelling study

New experimental equilibrium data were obtained for the solubility of carbon dioxide in an aqueous solution with 30 wt.% of 2-((2-aminoethyl)amino)ethanol (AEEA) at temperatures ranging from (313.2 to 368.2) K and CO₂ partial pressures ranging from above atmospheric to 4400 kPa. A thermodynamic model based on the Deshmukh–Mather method was applied to correlate and predict the CO₂ solubility in aqueous AEEA solutions. The binary interaction parameters and equilibrium constants for the proposed reactions were determined by data regression. Using the adjusted parameters, equilibrium partial pressures of CO₂ were calculated and compared with the corresponding experimental values at the selected temperatures and pressures. Values of carbon dioxide solubility at other temperatures reported in the literature were also calculated. The average absolute deviation for all of the data points was found to be 8.2%. The enthalpy change of the absorption of CO₂ in the 30 wt.% aqueous solution of AEEA was also estimated with our model.