脂肪胺水溶液吸收CO2的热力学参数的密度泛函理论研究

采用密度泛函理论研究CO2在脂肪胺水溶液热力学参数．研究的脂肪胺包括烷基胺、链烷醇胺、二胺以及氨基酰胺．在B3LYP/6-311＋ G（d,p）水平计算脂肪胺在CO2气相中的振动频率．通过连续介质模型在HF/6-31G（d）水平计算了溶剂几何优化的标准自由能,评价了CO2吸收到脂肪胺水溶液过程有关的两个重要参数：酸解离常数和标准焓变二者之间大致呈线性关系．随着胺碱度的提高,CO2吸收过程释放的热量增加,则胺再生所需的能量增加．     

Experimental studying of the effect of active area on the performance of passive direct methanol fuel cell

This work experimentally studies the effect of the size and shape of active area on the performance of passive direct methanol fuel cell. The obtained results show that the cell performance strongly depends on the size and shape of active area. Experimental results of this study also demonstrate that the cell performance improves with an increase in the size of active area. Increasing the size of active area also leads to a lower internal resistance, lower OCV, and higher operating temperature. Furthermore, it was found that the smallest active area (4 cm²) produced the longest stable discharging voltage (about 16.5 h). This study also reveals that the square active area has the best performance and the highest power density compared to the rectangular and circular active areas. Finally, the results prove that the place of applying the clamping force is an important parameter that should be considered in the cell design.     

Invariant G2V algorithm for computing SAGBI-Gröbner bases

Faugère and Rahmany have presented the invariant F5 algorithm to compute SAGBI-Grbner bases of ideals of invariant rings. This algorithm has an incremental structure, and it is based on the matrix version of F5 algorithm to use F5 criterion to remove a part of useless reductions. Although this algorithm is more efficient than the Buchberger-like algorithm, however it does not use all the existing criteria (for an incremental structure) to detect superfluous reductions. In this paper, we consider a new algorithm, namely, invariant G2V algorithm, to compute SAGBI-Grbner bases of ideals of invariant rings using more criteria. This algorithm has a new structure and it is based on the G2V algorithm; a variant of the F5 algorithm to compute Grbner bases. We have implemented our new algorithm in Maple , and we give experimental comparison, via some examples, of performance of this algorithm with the invariant F5 algorithm.     

Numerical study of melting in an enclosure with discrete protruding heat sources

In order to explore the capability of a solid–liquid phase change material (PCM) for cooling electronic or heat storage applications, melting of a PCM in a vertical rectangular enclosure was studied. Three protruding generating heat sources are attached on one of the vertical walls of the enclosure, and generating heat at a constant and uniform volumetric rate. The horizontal walls are adiabatic. The power generated in heat sources is dissipated in PCM (n-eicosane with the melting temperature, T_m = 36 °C) that filled the rectangular enclosure. The advantage of using PCM is that it is able to absorb high amount of heat generated by heat sources due to its relatively high energy density. To investigate the thermal behaviour and thermal performance of the proposed system, a mathematical model based on the mass, momentum and energy conservation equations was developed. The governing equations are next discretised using a control volume approach in a staggered mesh and a pressure correction equation method is employed for the pressure–velocity coupling. The PCM energy equation is solved using the enthalpy method. The solid regions (wall and heat sources) are treated as fluid regions with infinite viscosity and the thermal coupling between solid and fluid regions is taken into account using the harmonic mean of the thermal conductivity method. The dimensionless independent parameters that govern the thermal behaviour of the system were next identified. After validating the proposed mathematical model against experimental data, a numerical investigation was next conducted in order to examine the thermal behaviour of the system by analyzing the flow structure and the heat transfer during the melting process, for a given values of governing parameters.     

Highly porous WO3/CNTs-graphite film as a novel and low-cost positive electrode for vanadium redox flow battery

Journal of Solid State Electrochemistry - In this study, novel and low-cost tungsten oxide/carbon nanotubes-graphite-polyvinyl chloride (WO3/CNTs-graphite-PVC) film with porous 3D network structure...     

The anticancer impacts of N,S donor pyrazole based ligand and its Co(III) and Cu(II) complexes on breast cancer cells

Transition Metal Chemistry - The development of suitable compounds for the effective treatment of cancer is highly demanded. Inorganic complexes based on cobalt and copper centers have revealed a...     

Application of the Fe3O4@1,10‐phenanthroline‐5,6‐diol@Mn nano‐catalyst for the green synthesis of tetrazoles and its biological performance

The Fe₃O₄ magnetic particles were modified with 1,10‐phenanthroline‐5,6‐diol (Phen) and the related Mn complex (Fe₃O₄@Phen@Mn) synthesized as a heterogeneous catalyst to be used for the one‐pot three‐component synthesis of various tetrazoles. The catalysts were characterized by several methods, such as the elemental analysis, FT‐IR, X‐ray powder diffraction, dispersive X‐ray spectroscopy, scanning electron microscopy, transmission electron microscopy, dynamic light scattering, thermogravimetric‐differential thermal analysis, vibrating sample magnetometer and X‐ray photoelectron spectroscopy. In addition, the antioxidant and antibacterial activities of the catalyst and its Phen ligand were in vitro screened with 2,2‐diphenyl‐1‐picrylhydrazyl by free radical scavenging methods. Results showed that the synthesized compounds possess strong antioxidant activity (IC50; 0.172  ±  0.005 mg ml^?1) as well as a good antibacterial potential in comparison to standards.