Dual complex of amylose with iodine and magnetite nano‐crystallites: Enhanced superparamagnetic and catalytic performance for synthesis of spiro‐oxindoles

Mass magnetization of magnetite nanoparticles was enhanced by disassembling and encapsulating their building nano‐crystallites with water‐soluble starch. Incorporation of iodine into the as‐prepared nano‐conglomerate led to formation of a ternary nano‐complex and further enhancement of its superparamagnetic susceptibility. As an additional evidence for the anomalously heightened superparamagnetic property, the ternary nano‐complex showed lower magnetic remanence and coercivity than the pristine magnetite it was made from. These findings were ascribed to significant changes in, at least, size of the magnetite nano‐crystallites during formation of the nano‐composite. A significant enhancement was also observed in the catalytic efficiency of the nano‐composite, as was successfully exemplified in the synthesis of some novel spiro[oxindole‐dihydropyridine]s via a three‐component reaction between isatins, furan‐2,4(3H,5H)‐dione and aminouracils ‘on water’.     

Finding susceptible areas for a 50 MW solar thermal power plant using 4E analysis and multiobjective optimization

Journal of Thermal Analysis and Calorimetry - In the present study, a power plant design was first carried out using thermo flow software. Energy, exergy, economic, environmental, and economic (4E)...     

A new quality appearance evaluation technique for automotive bodies including effect of flexible parts tolerances

Part tolerances have a crucial effect on the quality of products. In vehicle design, tolerance analysis is of central importance in quality appearance evaluation of automotive bodies and significantly taken into consideration by manufacturers in recent decades. This paper evaluates the surface quality of a car’s roof as one of the key quality characteristics in vehicle design. Compared to previous research in the area of quality appearance evaluation of automotive bodies, which are based on the assumption of part rigidity, the current research proposes to include part flexibilities in the analysis. The results of this study shows that input tolerances have a considerable effect on the surface quality of the final assembled product.     

Adsorption of nitrous oxide on the(6,0) magnesium oxide nanotube

Nitrous oxide adsorption on the pristine（6,0） magnesium oxide nanotube was studied by using density functional theory calculations.We present the nature of the N₂O interaction in selected sites of the nanotube.Adsorption energies corresponding to adsorption of the N₂O on the nanotube were calculated to be in the range -11.67 to -22.21 kJ mol^-1.Our results indicate that the N₂O molecule has a weak physical adsorption on the pristine models due to weak Van der Waals interaction between the nanotubes and N₂O molecule.The important results can be useful in production of the N₂O sensors.     

Simultaneous study of cure kinetics and rheology of montmorillonite/vinyl ester resin nanocomposites

In this work, the effect of quaternary ammonium salt containing nanoclay content (1–5 wt%) on phase morphology, rheology, cure kinetics, and mechanical properties of the vinyl ester resin (VER)‐based nanocomposites was studied. The morphological characterization including d‐spacing measurement, microscopy observation and phase‐height image processing were performed on the prepared nanocomposites using small angel X‐ray scattering (SAXS), transmission electron microscopy (TEM) and atomic force microscopy (AFM). According to the results obtained from these techniques, it was concluded that an intercalated morphology existed for all the nanocomposites. The kinetic analyses of the isothermal curing followed by storage modulus obtained from the rheometry experiments are shown to be an affective rheological characteristic to investigate the cure behavior of VER/clay nanocomposites. In addition, the most important finding regarding the effect of nanoclay on the cross‐linking behavior of VER systems lays on the chemisorption and physisorption of the reacting monomers and initiator molecules on the nanoclay platelets surface which is found to be responsible for the retardation of the cure reaction caused by organoclay. Eventually, the mechanical characterizations were performed through the tensile, flexural and impact analysis tests. In this case, a considerable improvement of the bulk mechanical responses such as tensile and flexural strengths and also the corresponding moduli were observed for the nanocomposites. Copyright © 2011 John Wiley & Sons, Ltd.     

A Unique Reversible Gate in Quantum-dot Cellular Automata for Implementation of Four Flip-flops Without Garbage Outputs

In this paper, a unique gate is presented for the design of reversible flip-flops in quantum-dot cellular automata technology. The proposed gate is implemented with multiplexer, three-input Majority gate and XOR gate. The proposed gate has four input lines and four output lines. This gate is designed without garbage outputs. In other words, each output determines the function of each of flip-flops. The proposed structure is evaluated by the QCADesigner. The result of the simulation represents that the operations of the proposed structure is as expected and all functions are correct. Also, the evaluation results show that the proposed structure has significant improvement in area, cell numbers and delay compared to the previous structures. QCAPro tool is used to estimate energy consumption of the proposed structure.     

Fischer–Tropsch synthesis over CNT-supported cobalt catalyst: effect of magnetic field

In the present work, the cobalt catalysts supported on carbon nanotubes (CNTs) were prepared by impregnation method in the presence and absence of magnetic field. The prepared catalysts were employed to yield higher hydrocarbons via Fischer–Tropsch synthesis. It is explored that using magnetized water can effectively change the catalyst geometry in impregnation catalyst preparation method. For the preparation of different sizes of cobalt particles on the CNTs support, the physical properties of solvent (water) in impregnation process were changed using the magnetizing process. The results showed that the average particle sizes of impregnated cobalt nanoparticles were decreased by using magnetized water in impregnation step. In addition, in the magnetized treated cobalt catalyst, the cobalt particles mostly dispersed outside the tubes because the capillary forces decreased by reducing water surface tension. Furthermore, the experimental results showed that the probability of chain growth (α) and selectivity to heavier hydrocarbons increased in magnetized water treatment catalysts.     

Pore formation in phospholipid bilayers by amphiphilic cavitands

Five new cavitands were prepared that have four pendant n-undecyl chains and "headgroups" connected by 2-carbon spacers. The headgroups were ~OCH(2)CONH-Ala-OCH(3), 1; ~OCH(2)CONH-Phe-OCH(3), 2; ~OCH(2)CONH-Ala-OH, 3; ~OCH(2)CONH-Phe-OH, 4; and ~OCH(2)CONHCH(2)CH(2)-thyminyl, 5. Pore formation by each cavitand was studied by use of the planar bilayer conductance experiment. All five compounds were found to form pores in asolectin bialyer membranes. Compounds 1-3 behaved in a generally similar fashion and exhibited open-close dynamics. Compounds 4 and 5 formed pores more rapidly, were more dynamic, and led more quickly to membrane rupture. Differences in the ion transport activity are rationalized in terms of structure and aggregate cavitand assemblies.