Chemical Review and Letters
Volume:2 Issue: 4, Autumn 2019

 The adsorption of a toxic gas, cyanogen chloride (CNCl) on pristine, Al– and Si–doped BN nanosheet investigated using density functional theory (DFT). The adsorption energies of the most stable complexes of CNCl on pristine, Al– and Si–doped BN nanosheet are –19.96, –95.02 and –176.90 kj/mol, respectively. We found that the CNCl gas has a chemisorption interaction over the Al– and Si–doped BN, with significant change in the structure shape of the CNCl molecule. The value of adsorption interaction energy of Si-boron nitride is very large than that of the Al-boron nitride toward the toxic gas. As a result the Si-boron nitride nanosheet is more reactive to dissociate the gas molecule into safely small fragments. The adsorption of the CNCl molecule can significantly decrease the HOMO–LUMO energy gap of the Al–doped BN by about 14.06%. It is suggested that the Al–doped BN can be considered as a potential nanostructure for sensing the toxic CNCl.

The work entails the viscometric study of a common plant gum found in Nigeria (Acacia Senegal) blended with polyacrylamide (PAM). The gum was purified after collected and mixed in specific ratios of 10:90, 30:70, 50:50, 70:30 and 90:10 with PAM, before they were subjected to rheological study. The intrinsic, relative and specific viscosity for the bends were determined and presented in the research work. The plots of the relative viscosity against concentration of the gums at different temperature vary significantly at higher concentration, while the viscosity for gum Arabic/PAM (90:10) showed the most distinct variation between different temperatures. The result was found to be agreement with some other similar research in the literature. PAM was found to be more viscose than gum Arabic at both temperatures, while the viscosity index such as intrinsic, specific and relative viscosity for the synergistic combination between the polymers were found to decrease as we increased the composition of gum Arabic within the blend.

Heat flux is passed through the tube wall with natural convection in a tube wall of developed laminar flow. Tubes are used to find the best case with the minimum enthalpy and entropy generation. Process of heat flux pass is simulated with natural convection in several cases through the wall. By varying heat flux along the tube kept in touch with natural convection, temperature, entropy generation and enthalpy of each case change. Tubes are studied distribution of temperature, entropy generation and enthalpy along the radius and distribution of entropy generation and enthalpy along the cylinder axis, via different diagrams. Entering heat flux to the tube wall, temperature, entropy generation and enthalpy of the fluid increase significantly along the radius. The contact of heat flux to the tube wall in the direction of fluid movement, entropy generation decreases in the flow direction. Heat flux is applied to the tube wall, in parts of the tube being a heat flux, enthalpy increases in the direction of the tube wall. Enthalpy is reduced in the tube wall in parts that are associated with the natural convection. The novelty of the work is heat flux and natural convection on the pipe in various fluids and air in electric coil on the tube as heat flux and diesel furnace, solar water heaters, refrigerant tube etc. Material is not a special. Material is the fluid with high Prandtl number by number of 13400. Method of the paper is design and simulation by ansys software 15.0.7.

We have perused the absorbency of N2H4, P2H4, O2H2 and S2H2 molecules on the exterior level of pristine and Al- and Ga-embeded B12N12 nanostructures using through density functional theory (DFT) calculations. The consequences indicates that most favorable adsorption configurations are those in which the nitrogen atom of hydrazine (N2H4) is closed to boron, Aluminum and Gallium atoms of pristine and Al- and Ga-embeded B12N12 nanostructures, respectively, with adsorption energies circa -1.801, -2.397, and -2.071 eV. Geometry optimizations, energy calculations and NBO charge transfer were used to evaluate the impression ability of B12N12 for various analytes. The computed density of states (DOS) displaies that a notable orbital hybridization be take place between N2H4 P2H4, O2H2 and S2H2 molecules with pristine and Al- and Ga-embeded B11N12 nanostructures adsorption process. Finally, we concluded that the Al-embeded B11N12 is more desirable than that of the pristine for N2H4 adsorption.

In this review, we will summarize the available literature on the preparation of nitro compounds from the corresponding carboxylic acids through nitrodecarboxylation. The review is divided into three major sub-sections. The first focuses exclusively on nitrodecarboxylation of aliphatic carboxylic acids. The second will discuss decarboxylative nitration of aromatic carboxylic acids. The third section will cover the synthesis of nitroolefins via decarboxylative nitration of α,β-unsaturated carboxylic acids. Particular emphasis is paid to the mechanistic aspect of reactions.

Quantitative structure-activity relationship (QSAR) is the most extensively used computational methodology for analogue-based design. In this research, QSAR model was used to predict antiproliferative properties of 4-(2-fluorophenoxy) quinoline derivatives against A549(human lung adenocarcinoma). For this purpose, we used the multiple linear regressions (MLR) for the construction of a model to predict drug activity and Stepwise (SW) and genetic algorithm (GA) methods used to build the model. The data were selected from 31 molecules with specific pharmacological activity. They were divided into two sets train and test data. The resulting model was tested using statistical methods such as external test set and cross-validation to ensure its authenticity. The results showed that GA-MLR approach had good predictive power and higher data rates compared with SW-MLR (Q2LOO = 0.877, R2Train =0.933). The results obtained in this study can be used to design drugs with higher performance and pharmacological activity to treat lung cancer.