Derived thermodynamic properties of [o-xylene or p-xylene + (acetic acid or tetrahydro-furan)] at different temperatures and pressures

Thermal expansion coefficients α, their excess values , isothermal coefficient of pressure excess molar enthalpy , partial molar volumes and excess partial molar volumes , were calculated from experimental densities. The isothermal coefficients of pressure excess molar enthalpy for binary mixtures {o-xylene or p-xylene + acetic acid} at temperatures 313.15-473.15 K and pressure 0.2-2 MPa are negative and for binary mixtures {o-xylene or p-xylene + tetrahydrofuran (THF)} at temperatures 278. 15 K to 318.15 K and pressure 81.5 kPa are negative and with increasing temperature become more negative. The excess thermal expansions coefficient , for binary mixtures {o-xylene or p-xylene + acetic acid} at temperatures 313.15-473.15 K and pressure 0.2 MPa and 2 MPa are positive. The excess thermal expansions coefficient for binary mixtures {o-xylene or p-xylene + tetrahydrofuran (THF)} at temperatures 278.15-318.15 K and pressure 81.5 kPa are positive and with increasing temperature become more positive. The excess molar volumes were correlated with a Redlich–Kister type equation.KEY WORDS: Thermal expansion coefficients, Isothermal coefficient, Excess partial molar volumes Bull. Chem. Soc. Ethiop. 2011, 25(2), 273-286.

Multi-Module G2P Converter for Persian Focusing on Relations between Words

In this paper, we investigate the application of end-to-end and multi-module frameworks for G2P conversion for the Persian language. The results demonstrate that our proposed multi-module G2P system outperforms our end-to-end systems in terms of accuracy and speed. The system consists of a pronunciation dictionary as our look-up table, along with separate models to handle homographs, OOVs and ezafe in Persian created using GRU and Transformer architectures. The system is sequence-level rather than word-level, which allows it to effectively capture the unwritten relations between words (cross-word information) necessary for homograph disambiguation and ezafe recognition without the need for any pre-processing. After evaluation, our system achieved a 94.48% word-level accuracy, outperforming the previous G2P systems for Persian.Comment: 10 pages, 4 figure

Theoretical studies of 31P NMR spectral properties of phosphanes and related compounds in solution

Selected theoretical methods, basis sets and solvation models have been tested in their ability to predict 31P NMR chemical shifts of large phosphorous-containing molecular systems in solution. The most efficient strategy was found to involve NMR shift calculations at the GIAO-MPW1K/6-311++G(2d,2p)//MPW1K/6-31G(d) level in combination with a dual solvation model including the explicit consideration of single solvent molecules and a continuum (PCM) solvation model. For larger systems it has also been established that reliable 31P shift predictions require Boltzmann averaging over all accessible conformations in solution

Effects of influence of carbon ring-doping on NMR parameters of boron phosphide nanotubes: A DFT study

AbstractThe electronic structure of boron phosphide nanotubes (BPNTs) and influence of carbon ring doping (C-doping) in the horizontal region (model A) and vertical region (model B) of BPNTs is studied by density functional theory (DFT). At first, each form was optimized at B3LYP level of theory using 6-31G∗ bases set. After, the computed chemical shielding (CS) tensors at the sites of 11B and 31P nuclei were converted to isotropic chemical shielding (CSI) and anisotropic chemical shielding (CSA). The calculated results reveal that the CS parameters of B and P nuclei in C-ring doped on vertical region (model B) undergo more significant changes than horizontal region (model A)

A computational assessment of the interaction of 5Fluorouracil (5FU) drug connected to B 12 P 12 and ScB 11 P 12 nanocages with adenine nucleobase: DFT, AIM, TD-DFT study

Abstract Intelligent transfer of drugs to target cells is one of the important challenges in pharmaceuticals and disease treatment. Based on this, various investigations have been done on the interaction of drugs with different materials and compounds, among which nanomaterials have received more attention due to their wide active surface. In this context, the interaction of 5Fluorouracil (5FU) drug connected B12P12 and ScB11P12 nanocages with the adenine nucleobase is investigated. The results of this study could provide a new idea about the effect of nanocages on drug binding to nucleobase. The computational studied base on the density functional theory at the ωB97XD/6-31G (d, p) level of theory is fulfilled in presence of a static electric field (SEF) in the z-direction (z + 0.01, z + 0.02, z + 0.03, and z + 0.04 au). The outcomes of this study confirm that the interaction of 5FU&amp;B12P12 and 5FU&amp;ScB11P12 complexes with adenine is exothermic and favorable. The electrical localized field (ELF) plots, quantum theory of atom in molecule (QTAIM) outputs, and reduced density gradient (RDG) scatter plots have been computed and results are analyzed. The output results demonstrated that the nature of bonding between 5FU&amp;B12P12, and 5FU&amp;ScB11P12 complexes with adenine is electrostatic type. The results of this study recommended that the doping Sc atom and electrical field application increase the interaction of 5FU-drug&amp;B12P12 nanocage with adenine and it is an efficient system for 5FU drug delivery toward target cells.</jats:p