A novel construction of substitution box using a combination of chaotic maps with improved chaotic range

The influential application of substitution boxes in secure communication and multimedia security attracted researchers to construct more robust substitution boxes. The advantage of using chaos in the secure communication is to get additional unpredictability and randomness in data. In this paper, substitution boxes are constructed with the help of chaotic system and linear fractional transformation. The 256 distinct values of each substitution box are then checked with the help of different available algebraic and statistical analyses. These tests evaluate the strength and application of substitution boxes in different encryption techniques. The results indicate the strength of anticipated technique.

     

KCC-1 aminopropyl-functionalized supported on iron oxide magnetic nanoparticles as a novel magnetic nanocatalyst for the green and efficient synthesis of sulfonamide derivatives

A new magnetic nanocatalyst (Fe₃O₄@KCC-1-npr-NH₂) was synthesized directly through the reaction of Fe₃O₄@KCC-1 with (3-aminopropyl) triethoxysilane (APTES) using a hydrothermal protocol. Prepared nanocomposite was used as a magnetically reusable nanocatalyst for an efficient synthesis of a broad range of sulfonamide derivatives in water as a green solvent at room temperature and the products are collected by filtration with excellent yields (85–97%). The nanocatalyst could be remarkably recovered and reused after ten times without any significant decrease in activity. This mild and simple synthesis method offers some advantages including short reaction time, high yield and simple work-up procedure.     

Iron oxide magnetic nanoparticles supported on amino propyl-functionalized KCC-1 as robust recyclable catalyst for one pot and green synthesis of tetrahydrodipyrazolopyridines and cytotoxicity evaluation

In this study, paramagnetic dendritic fibrous nano-silica functionalized by aminopropyltriethoxysilan (Fe₃O₄@KCC-1-nPr-NH₂) was synthesized using a novel hydrothermal protocol and used as a highly efficient, recyclable and heterogeneous nanocatalyst for the synthesis of a wide range of tetrahydrodipyrazolopyridines derivatives ( 5a-5 m ). The influence of different reaction parameters, such as the effects of solvent, temperature, time and concentration of catalyst for the synthesis of tetrahydrodipyrazolopyridine (2a) were studied. This catalyst could be reused for ten consecutive recycles without any considerable loss in its catalytic activity. This novel synthesis method offers some advantages including short reaction time, high yield and simple work-up procedure. Finally, the newly synthesized tetrahydrodipyrazolopyridines derivatives ( 5a-5f ) were characterized by ¹H and ¹³C NMR, IR and CHN.     

Experimental study of the subcooled flow boiling heat transfer of magnetic nanofluid in a vertical tube under magnetic field

Journal of Thermal Analysis and Calorimetry - In this study, the subcooled boiling heat transfer of a Fe3O4/water magnetic nanofluid flowing through a vertical tube has been investigated...     

Nonlinear dynamical responses of forced carbon nanotube-based mass sensors under the influence of thermal loadings

Nonlinear Dynamics - This study presents an analytical solution for the nonlinear forced vibration response of bridged carbon nanotube (CNT)-based mass sensors subjected to different types of...     

Synthesis,characterization and catalytic properties of a copper-containing polyoxovanadate nanocluster in azide–alkyne cycloaddition

A copper-containing polyoxovanadate nanocluster, [(C₂H₅)₄N]₄[V₈Cu₂O₂₄]?2H₂O (1), was synthesized through reaction between the Cu(NO₃)₂?3H₂O and [(C₂H₅)₄N]₄VO₃ in the molar ratio 1?:?4. Nanocluster 1 was characterized by IR, elemental analysis, XRD, SEM, TEM, and X-ray crystallography. The catalytic activity of 1 for the azide–alkyne cycloaddition of different terminal alkynes and organic azides generated in situ from sodium azide and different organic halides was tested. The protocol could afford the corresponding products in good to excellent yield at very low catalyst loadings (3.4 Mol%) under the optimized reaction conditions.     

Effect of acidification rate,acidification temperature,final pH,and stabilizer content on colloidal stability of whey-based pomegranate beverage

The effect of acidification rate (during 0, 30, and 60 minutes), acidification temperature (25, 50, and 75°C), final pH (3.4, 3.6, and 3.8), and pectin content (0.2, 0.4, and 0.6%) on the stabilization of whey-based pomegranate beverage was studied. Serum separation, particle size distribution, viscosity, zeta potential, pH, and acidity of beverage samples were observed during storage. Results revealed that acidification rate, acidification temperature, and pectin content had a significant effect; however, final pH (of the studied range) had no significant effect on the phase separation. The amount of phase separation decreased and the stability increased with increasing acidification rate, acidification temperature, and stabilizer content. In addition, the results of particle size, zeta potential, and viscosity confirmed the results of phase separation and also the most stable beverage had a pH near 3.8.     

Thermogravimetric analyses revealed the bioenergy potential of <Emphasis Type="Italic">Eulaliopsis binata</Emphasis>

The present study was focused on the thermal degradation of Eulaliopsis binata biomass produced on a salt-affected soil without any fertilizer or pesticide applications. The plant biomass was subjected to thermal degradation experiments at three heating rates, 10, 30 and 50 K min^?1. The kinetic analyses were performed through isoconversional models of Kissinger–Akahira–Sunose and Flynn–Wall–Ozawa, followed by the calculation of thermodynamic parameters of activation. The high heating value was calculated as 15.10 MJ mol^?1. The activation energy values of the grass were shown to be ranging from 118 through 240 kJ mol^?1. Energy difference of enthalpies of activation between the reagent and the activated complex was in accordance with activation energies. Pre-exponential factors indicated the reaction to follow first-order kinetics. Gibbs free energy for the grass was measured to be ranging from 171 to 174 kJ mol^?1. Our data have shown that E. binata biomass offers remarkable potential as a low-cost biomass for bioenergy.     

Application of nitrogen-rich porous organic polymer for the solid-phase synthesis of 2-amino-4H-benzo[b]pyran scaffolds using ball milling process

Molecular Diversity - This paper presents the efficient synthesis of 2-amino-4H-benzo[b]pyrans using mesoporous poly-melamine-formaldehyde as a polymeric heterogeneous catalyst. According to the...