Analysis of addent interactions with respect to the theory of electrophilicity and nucleophilicity indexes and kinetic studies shows the polar nature of [2+3] cycloaddition of (Z)-C-(m,m,p-trimethoxyphenyl)-N-(p-methylphenyl)-nitrone to (E)-3,3,3-trichloro-1-nitroprop-1-ene. However, PES exploration results do not confirm any zwitterion on the reaction paths. On the other hand, the nature of the solvent effect and the experimentally determined activation parameter values do not exclude a scenario in which one-step and stepwise processes occur simultaneously.
Studies linking high trans-fat diets to coronary heart disease (CHD) have prompted the need to regulate, limit, or completely ban trans-fat from all commercial food products, including fast foods. Many U.S. fast food chains now claim that their food items, particularly French fries, have "no trans-fat". In a previous study, our lab tested the validity of trans-fat claims made by several popular fast food restaurants by experimentally determining the %trans-fat in oil extracted from fast food French fries. In some cases, the trans-fat content was nearly twice as high as the amount reported by the restaurant in their literature. Long John Silver & apos; s, for example, reported a trans-fat content of 25% for their French fries, while our lab actually found over 40% trans-fat. The purpose of this study is to broaden our study of Long John Silver & apos; s trans-fat claims by analyzing a variety of their food items and comparing our findings with the %trans-fat reported by the restaurant literature (nutrition fact tables). Variable Filter Array (VFA) IR spectroscopy was used to assess the trans-fat content of oil extracted from food samples. Our preliminary findings suggest that nearly every food item under study contained considerably more trans-fat than the amount reported in the restaurant’s literature.
In this paper, a rapid and simple approach was developed for the preparation of zinc pentacyanonitrosylferrate nanotubes (ZnPCNF NTs) within the cylindrical pores of anodic aluminum oxide (AAO) template by electrochemical method. The AAO was fabricated in two steps anodizing from aluminum foil. The first anodization of aluminum foil was performed in 0.2 mol L-1 H2C2O4 followed by removal of the formed porous oxide film by a solution of 6 wt% of phosphoric acid. The second anodization step was then performed using the same conditions as the previous step. Scanning electron microscope (SEM) and X-ray diffraction (XRD) method were employed to characterize the resulting highly oriented uniform hollow tube array which its diameter was in the range of 25-75 nm depending on the applied voltage and the length of nanotubes was equal to the thickness of AAO which was about 2 ?m. The growth properties of the ZnPCNF NTs array film can be achieved by controlling the structure of the template and applied potential across the cell.
Regioselective nitration of phenols using Sr(NO3)2 or benzyltriphenylphosphonium nitrate in the presence of H2SO4-silica had been realized under solvent free conditions. The reaction proceeds through the formation of nitronium ion, which attack the phenol ring preferential at ortho position in presence of Sr(NO3)2, forming mono nitrophenol. Para-orientation relative to hydroxyl group and mononitration of phenolic compounds was observed in the case of benzyltriphenylphosphonium nitrate. Some of the major advantages of this method are mild reaction conditions, high efficiency and regioselectivity of nitration and complementarity with other reported methods. In addition, benzyltriphenylphosphonium nitrate as nitrating reagent can be easily recycled.
Copper oxide nanoparticles were successfully synthesized by mechanochemical reaction, which is a green, low cost, solvent free, rapid method and followed by calcining treatment. Copper acetate monohydrate and urea were used as reagents and the resulted precursor was calcined at 500 ?C for 2h in air. The scanning electron microscopy (SEM) revealed the formation of nanoparticles with an average size of about 86 nm. The Fourier transform infrared (FT–IR) spectrum and X-ray powder diffraction (XRD) pattern of the product confirmed all of reflections can be indexed to pure phase of CuO with a monoclinic crystal system. The diffuse reflectance spectrum (DRS) showed a band gap of 1.7 eV.
An efficient one-pot synthesis of pyrano[2,3-c]pyrazoles via four-component reaction of phenyl hydrazine, ethyl acetoacetate, malononitrile and aromatic aldehydes, catalyzed by poly(4-vinylpyridine) is reported. This method provides many advantages such as, atom-economy, easy work up, clean procedure, short reaction times and high yields of products.
A new sol-gel derived ceramic-carbon composite electrode was fabricated by the use of CuI as modifier. The electrocatalytic activity of the copper iodide modified sol-gel derived ceramic-carbon composite (CIM-SGD-CCC) electrode was examined for the oxidation of hydrazine. Cyclic voltammetry was employed to study the electrochemical and electrocatalytic properties of the modified electrode. Results showed that the CIM-SGD-CCC electrode has very high catalytic activity for electrooxidation of hydrazine. This proves that the copper iodide bears the main role in electro-catalytic oxidation of hydrazine. This modified electrode shows fast amperometric response with the range from 1 ? mol L-1 to 40 ? mol L-1 and the limit of detection (LOD) of 0.524 ? mol L-1 for hydrazine. The relative standard deviation (R.S.D.) was 0.72 % for 5 successive assays. High stability, good reproducibility, rapid response, easy surface regeneration and fabrication are the important characteristics of the proposed electrode.
In this work, we report on the synthesis of SiO2 hollow spheres using carbon nanospheres as the sacrificial template by hydrothermal method. The synthesized substrates are in a spherical morphology and uniform size distribution. The effects of hydrothermal process, concentration and the reaction temperature were optimized during synthesis of carbon nanospheres. Infrared spectroscopy (IR), and scanning electronic microscopy (SEM) methods were used for identification of the synthesized products. The synthesized SiO2 nanospheres were used as drug carrier to investigate in vitro release behavior of monoterpenic phenol isomers, carvacrol and thymol, in simulated body fluid (SBF). Ultraviolet-visible spectroscopy (UV-vis) method was carried out to determine the amount of the drugs entrapped in the carrier. The results indicated that SiO2 nanospheres have high ability to adsorb the drugs and there is no need for adjusting the pH during the adsorption process. The drug release profile shows a three stages pattern and indicates a delayed release action.
Chemically attachment of Schiff base complexes on multiwalled carbon nanotubes (MWCNTs) surfaces through a convenient and simple method was studied. In the first step of this method, we present a new method for preparation of aminated MWCNTs in order to attachment of (new) chlorinated salen Schiff bases. Amination of multiwalled carbon nanotubes performed under microwave (MW) irradiation through a one pot two step reaction. The chemically attachment of salen Schiff bases on functionalized MWCNTs (salen@MWCNTs) performed under a facile simple nucleophilic substitution reaction and complexation of attached salen Schiff bases (salen complex@MWCNTs) in last step, have been occurred with reaction of transition metal salts and salen@MWCNTs. The obtained products were characterized in detail, using FTIR, XRD, UV-Vis absorption, SEM and EDX methods.
The present paper deals with the characterization of ion exchange resins Dowex 550A LC and Indion-930A based on kinetics of ion-isotopic exchange reactions for which the short lived radioactive isotopes 131I and 82Br were used as a tracers. The study was performed for different concentration of ionic solution varying from 0.001 mol/L to 0.004 mol/L and temperature in the range of 30.0 °C to 45.0 °C. The results indicate that as compared to bromide ion-isotopic exchange reaction, iodide exchange reaction take place at the faster rate. For both the ion-isotopic exchange reactions, under identical experimental conditions, the values of specific reaction rate increases with increase in the ionic concentration and decreases with rise in temperature. It was observed that at 35.00C, 1.000 g of ion exchange resins and 0.002 mol/L labeled iodide ion solution for iodide ion-isotopic exchange reaction, the values of specific reaction rate (min-1), amount of ion exchanged (mmol), initial rate of ion exchange (mmol/min) and log Kd were 0.270, 0.342, 0.092 and 11.8 respectively for Dowex 550A LC resin, which was higher than the respective values of 0.156, 0.241, 0.038 and 7.4 as that obtained for Indion-930A resins. From the results, it appears that Dowex 550A LC resins show superior performance over Indion-930A resins under identical experimental conditions.