A proposed unsteady bioconvection model for transient thin film flow of rate-type nanoparticles configured by rotating disk

Journal of Thermal Analysis and Calorimetry - The revolution in nanotechnology has made new developments toward enhancement of energy resources which play a substantial role in the growth of...     

Thermodynamic potential of a high-concentration hybrid photovoltaic/thermal plant for co-production of steam and electricity

Journal of Thermal Analysis and Calorimetry - A thermodynamic model was developed to assess the energetic performance of a dual receiver concentrated photovoltaic/thermal plant for the...     

Merging Visible-Light Catalysis for the Direct Late-Stage Group-16–Trifluoromethyl Bond Formation

The use of visible light activation/photoredox chemistry for the generation of radical-centered chalcogen–CF₃ has gained widespread interest in the last past three years. Its subsequent reactivity for the synthesis of new chalcogen–CF₃-containing building blocks gained much attention. To date several methodologies have been developed addressing several challenges in modern organofluorine chemistry and enabled substantial progress in substrates scope and reaction conditions. This review describes these advancements with a particular focus on the reaction mechanisms.     

Physical properties of suspension ZnO nanoparticles prepared by wet chemical method: Comparison study

In this work a suspension of Nano-crystalline of ZnO particle is prepared by wet chemical at different temperature and concentration. From FTIR spectral exhibit present of Zn–O bond which indicate to formation ZnO particles. While all suspension and nano films exhibit a high transmittance in visible region about 90% which falls sharply in the UV region. The particle size is measured by using effective mass approximation (EMA), which was approximation (1.7–1.96 nm), and the band gap changes from 3.95 to 4.52eV for nanoparticles in suspension, and change from 3.76 to 3.94 eV for nanoparticles in ZnO film, which is change as function of concentration, temperature and aging time. Hall Effect measurements for ZnO films exhibit n-type conductivity for films deposited with activation energy 0.742eV at high temperature and 0.178eV at low temperature which is different as prepared sample conditions. Also the nanoparticle suspension and nanoparticle film could be implemented as a filter with variable cut off (8.9 × 10¹⁴–1.28 × 10¹⁵) H_Z.     

Influence of clay suspensions on the precipitation of CaCO3 in seawater

The effect of montmorillonite and kaolinite, most common clay in marine water, on nucleation and growth of calcium carbonate in standard sea water was studied. Crystallization was induced by the degasification of the dissolved carbonic gas. It was shown by XRD and SEM analysis that CaCO₃ crystallize under its aragonite polymorph some either the clay concentration or type. It was also found that tested clays inhibited significantly the crystallization of calcium carbonate, especially for concentrations higher than 25 mgL^–1. From the fine analyses of the formed solid, it was suggested that the tested clays have an indirect effect on nucleation and growth of aragonite by increasing the Mg ions concentration, strong inhibitor of CaCO₃ formation, in the neighbourhood of clay particles where supersaturation is the higher and than crystallization can occur. In addition to its indirect role, kaolinite can interact with aragonite by adsorbing on their faces and blocking growth sites (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Effect of discrete macroion charge distributions in solutions of like-charged macroions

The effect of replacing the conventional uniform macroion surface charge density with discrete macroion charge distributions on structural properties of aqueous solutions of like-charged macroions has been investigated by Monte Carlo simulations. Two discrete charge distributions have been considered: point charges localized on the macroion surface and finite-sized charges protruding into the solution. Both discrete charge distributions have been examined with fixed and mobile macroion charges. Different boundary conditions have been applied to examine various properties. With point charges localized on the macroion surface, counterions become stronger accumulated to the macroion and the effect increases with counterion valence. As a consequence, with mono- and divalent counterions the potential of mean force between two macroions becomes less repulsive and with trivalent counterions more attractive. With protruding charges, the excluded volume effect dominates over the increased correlation ability; hence the counterions are less accumulated near the macroions and the potential of mean force between two macroions becomes more repulsive/less attractive.     

Impact of melting heat transfer in the time-dependent squeezing nanofluid flow containing carbon nanotubes in a Darcy-Forchheimer porous media with Cattaneo-Christov heat flux

This study aims to investigate the time-dependent squeezing of nanofluid flow, comprising carbon nanotubes of dual nature, e.g. single-walled carbon nanotubes, and multi-walled carbon nanotubes,between two parallel disks. Numerical simulations of the proposed novel model are conducted,accompanied by Cattaneo-Christov heat flux in a Darcy-Forchheimer permeable media. Additional impacts of homogeneous–heterogeneous reactions are also noted, including melting heat. A relevant transformation procedure is implemented for the transition of partial differential equations to the ordinary variety. A computer software-based MATLAB function, bvp4c, is implemented to handle the envisioned mathematical model. Sketches portraying impacts on radial velocity, temperature, and concentration of the included parameters are given, and deliberated upon. Skin friction coefficient and local Nusselt number are evaluated via graphical illustrations. It is observed that the local inertia coefficient has an opposite impact on radial velocity and temperature field. It is further perceived that melting and radiation parameters demonstrate a retarding effect on temperature profile.     

Formulating Middle Phase Microemulsions Using Extended Anionic Surfactant Combined with Cationic Hydrotrope

The phase behavior of systems containing sodium alkyl polypropylene oxide sulfate with equimolar ratio of polypropylene oxide ammonium chloride was determined as a function of salt concentration and alkane carbon number at ambient temperature. Visual inspection as well as cross polarizers were used to detect anisotropy. Solubilization ratios for oil and brine in the middle phases were measured and used to calculate the interfacial tension (IFT) between the microemulsion and oil or brine. The fish diagram is presented showing a minimum amount of 0.20 wt% surfactant needed to form the middle phase. Swelling increases with decreasing the alkane carbon number of the oil. Ultra low IFT values were predicted for the systems investigated.