Thermal analysis in swirling flow of titanium dioxide–aluminum oxide water hybrid nanofluid over a rotating cylinder

Journal of Thermal Analysis and Calorimetry - The purpose of this study is to examine the flow features and heat transfer in the presence of nanoparticles which are used to enhance the...     

Influence of diazonium-induced surface grafting on PES NF membrane fouling reduction in algal-rich water treatment

The algae bloom phenomenon incurs a major challenge to conventional drinking water treatment processes due to the discharges of a large amount of intracellular pollutant and odor compounds in the water sources. Membrane processes have been considered as promising technologies to treatment of algal-rich water due to complete algal cell rejection however, its application has been limited by membrane fouling. In this work, the high-performance loose antifouling PES NF membranes were fabricated using diazonium-induced grafting and applied for treating real algal effluent. The modified membranes exhibited complete algal dye removal and turbidity removal throughout the long-term filtration. Also, the coupling and radically modified membranes can be able to removed COD by up to 90% and 88%, respectively, while a removal efficiency of 24% was observed for bare membrane. It is worth noting that, a relative smooth behavior in permeate flux by loose modified membranes during prolonged algal dye filtration, demonstrating exceptional anti-fouling property of membranes. In addition, the fouled modified membranes were effectively recovered by water flushing. Both loose modified membranes exhibited excellent resistance in the strongly acidic environment. These high performance antifouling NF membranes affords an innovative methodology toward the treatment of algal-rich water.     

Synthesis of propyl aminopyridine modified magnetite nanoparticles for cadmium (II) adsorption in aqueous solutions

In this study, 2‐aminopyridine functionalized magnetite nanoparticles were chemically synthesized and used for removing Cd²⁺ ions from aqueous solutions. The synthesized nanoparticles were characterized by Fourier transform infrared spectroscopy (FT‐IR), X‐ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive analysis of X‐rays (EDX), thermogravimetric analysis (TGA) and vibrating sample magnetometer (VSM). The SEM results showed the synthesized magnetite nanoparticles have particle size around 26 nm. The effects of several variables including solution pH and volume, adsorbent mass, ionic strength and contact time on the Cd²⁺ adsorption were studied in batch experiments and finally the optimum conditions for adsorption were obtained. The kinetic data were investigated by pseudo‐ first‐order, pseudo‐ second‐order, intraparticle diffusion and Elovich kinetic models and data were described reasonably by pseudo‐ second‐order model (R² = 0.9996) with q_e = 2.31 mg g^?1. Adsorption data were analyzed using Langmuir, Freundlich and Temkin isotherm models. The results indicated that the data were well fitted to the Freundlich isotherm model (R² = 0.9907). After study the possible interference effect of foreign ions on Cd²⁺ removal, the applicability of the proposed nanoparticles for adsorption from real samples confirmed the successfully removal of Cd²⁺ ions with removal efficiency higher than 92%. The obtained results showed that the synthesized nanoparticles as a reusable adsorbent can act as a good choice for Cd²⁺ removal with an easy procedure.     

Thermostable Broad Band Polarizing PVA-Film: Theoretical and Experimental Investigations

In the present work, for the first time on the basis of poly(vinyl alcohol)(PVA), 2-(4-dimethylaminostyryl)-1-ethylquinolinium iodide(quinaldine red(QR)) and trisodium(4 E)-5-oxo-1-(4-sulfonatophenyl)-4-[(4-sulfonatophenyl)hydrazono]-3 pyrazolecarboxylate(tartrazine(T)), thermostable polarizing film in a wide range of spectra(λ_(max) = 394～511 nm) with polarization efficiency(PE) = 98% in absorption maximum and stretching degree(Rs) = 3.5 was developed. The basic spectral-polarization parameters(polarization efficiency and transmittance) of oriented colored PVA-films were measured and discussed. During the work it was found that oriented PVA-films are the phenomenon of anisotropy of thermal conductivity(λⅡ/λl). It is a very important parameter for the development of thermostable PVA-polarizing films. For the first time quantum-chemical calculations using density functional theory(DFT) approach for structural analysis and electronic spectrum of the QR were carried out via the B3 LYP/dgdzvp and TDB3 LYP/dgdzvp methods. Interpretation of absorption strips in visible region of spectrum was also reported. The excitation energies, electronic transitions and oscillator strengths for the studied structures have also been calculated(B3 LYP/dgdzvp). The NBO analysis and Mulliken atomic charges of the QR were carried out.     

Computational hemodynamics investigation of the heat transfer of blood flow in different geometries of the patient’s body on different scales

Journal of Thermal Analysis and Calorimetry - Computational hemodynamics (CHD) simulation is regarded as a significant and robust method that is helpful for surgeons and the health recovery of...     

Bottleneck Problems: An Information and Estimation-Theoretic View

Information bottleneck (IB) and privacy funnel (PF) are two closely related optimization problems which have found applications in machine learning, design of privacy algorithms, capacity problems (e.g., Mrs. Gerber’s Lemma), and strong data processing inequalities, among others. In this work, we first investigate the functional properties of IB and PF through a unified theoretical framework. We then connect them to three information-theoretic coding problems, namely hypothesis testing against independence, noisy source coding, and dependence dilution. Leveraging these connections, we prove a new cardinality bound on the auxiliary variable in IB, making its computation more tractable for discrete random variables. In the second part, we introduce a general family of optimization problems, termed “bottleneck problems”, by replacing mutual information in IB and PF with other notions of mutual information, namely f-information and Arimoto’s mutual information. We then argue that, unlike IB and PF, these problems lead to easily interpretable guarantees in a variety of inference tasks with statistical constraints on accuracy and privacy. While the underlying optimization problems are non-convex, we develop a technique to evaluate bottleneck problems in closed form by equivalently expressing them in terms of lower convex or upper concave envelope of certain functions. By applying this technique to a binary case, we derive closed form expressions for several bottleneck problems.     

Fe3O4@MCM-48-SO3H:An efficient magnetically separable nanocatalyst for the synthesis of benzo[f]chromeno[2,3-d]pyrimidinones

Sulfonic acid groups were grafted onto three different types of synthesized magnetic nanoparticles, namely Fe3O4, Fe3O4@SiO2, and Fe3O4@MCM‐48. The sulfonic acid‐functionalized nanoparticles were evalu...     

Molecular modeling investigation of adsorption of Zolinza drug on surfaces of the B12N12 and Al12N12 nanocages

Structural Chemistry - In the current work, the adsorption of Zolinza (ZOL) drug on B12N12 and Al12N12 nanocages was investigated using density functional theory (DFT) and time-dependent DFT...