Correction to: Effect of trigonometric sine,square and triangular wavetype time-periodic gravity-aligned oscillations on Rayleigh–Bénard convection in Newtonian liquids and Newtonian Nanoliquids

Meccanica - The original article has been updated due to typesetting mistakes made in Section 2.2 Mathematical formulation, Table 1 and in Equation (51).     

Synthesis,structural aspects and nonlinear optical properties of novel phthalimide derivatives: theoretical and experimental approach

Novel phthalimides ( 1 , 2 , 3 ) possessing variability of cyclic amines have been synthesized and characterized by analytical and spectroscopic techniques. Phthalimide 1 and 2 crystallized in a triclinic system with space group Pī; however, an orthorhombic system with a chiral space group of P2₁2₁2₁ was observed for 3 possessing piperidine cyclic amine. The hydrogen atoms attached to the central chiral carbon were oriented anti to each other resulting in minimum steric repulsion. The occurrence of C–H···O hydrogen bonds in 1 , 2 , 3 enabled the building of several supramolecular structures. Hyperpolarizability 197.6096 Debye Ų calculated for 1 was found to be higher than the hyperpolarizabilities, 138.0836 and 165.2521 Debye Ų measured for 2 and 3 , respectively. Subsequently, phthalimides ( 1 , 2 , 3 ) were assessed for second harmonic generation (SHG) response, and a negligible response was recorded for 1 and 2 ; however, 3 showed a significant response of 14.2 mV. In addition to acentric structure, helical structural motifs identified in 3 could be responsible for its enhanced SHG response. Copyright © 2014 John Wiley & Sons, Ltd.     

Synthesis and deposition of nanostructured SnS for semiconductor-sensitized solar cell

Journal of Solid State Electrochemistry - Structural, electrical, and optical properties of SnS nanoparticles and films deposited by ultrasound-assisted chemical bath were studied. The SnS was...     

Polymerization of methyl methacrylate by charge-transfer mechanism with aliphatic primary amines and carbon tetrachloride

Polymerization of methyl methacrylate (MMA) with aliphatic primary amines and carbon tetrachloride has been investigated in th dimethylsulfoxide medium by employing a dilatometric technique at 60°C. The rate of polymerization (R_p) has been evaluated under the conditions, [CCl₄]/[amine] < 1 and > 1. The kinetic data indicate possible participation of the charge transfer complexes formed between the amine + CCl₄ and the amine + MMA in the polymerization of MMA. In the absence of CCl₄ or amine, no polymerization of MMA was observed under the present experimental conditions. The polymerization of MMA was inhibited by hydroquinone, indicating a free radical initiation. The energy of activation varied from 32 to 58 kJ mol^?1.     

Biorecognizable polymers: Structure-properties relationship

The biocompatibility of polymers depends on their chemical composition, as well as physical and physico-chemical structure. However, biocompatibility is not an intrinsic polymer property since it relates to a particular localization of the polymer in the living organism. Any foreign macromolecule may be recognized by the living organism as “non-self”. The degree of recognition can be altered by modification of the structure of macromolecules or biomaterial surfaces. Modification of biomacromolecules (e.g., enzymes¹) or biomaterial surfaces with hydrophilic polymers, e.g., poly(ethylene oxide²) or other semitelechelic hydrophilic macromolecules³ has been shown to minimize biorecognition. On the other hand, to achieve specific recognition by cell receptors and/or antigens, complementary structures have to be incorporated as a part of the polymer structure^{4, 5}. The biorecognition of fluorescently labeled N-(2-hydroxypropyl)-methacrylamide copolymers containing side-chains terminated in acylated galactosamine by Hep G2 cells on the cellular and subcellular levels can be visualized by confocal fluorescence microscopy. The recognition of modified water soluble macromolecules strongly depends on their solution properties⁶. Incorporation of stimuli sensitive moieties into copolymer side-chains permits to control recognition by external stimuli, e.g., irradiation^{7, 8}, resulting in the change of the copolymer conformation. On the other hand, the biorecognition of unsoluble (crosslinked) copolymers depends mainly on their surface structure. The rationale for the structure modification of synthetic copolymers to regulate biorecognition will be reviewed. The principles will be described for the interaction of synthetic polymers with enzymes⁹, cell surface receptors and/or antigens^{10, 11}, lectins of the gastrointestinal tract^{12, 13}, and immobilized lectins¹⁴.     

Mixed metal MgO–ZrO2 nanoparticle‐catalyzed O‐tert‐Boc protection of alcohols and phenols under solvent‐free conditions

An environmentally benign method for O‐tert‐Boc protection of alcohols and phenols catalyzed by MgO–ZrO₂ nanoparticles under solvent‐free conditions is described. A variety of phenols, alcohols (aliphatic and aromatic) were converted to corresponding O‐tert‐Boc products in good to excellent yield (50–95%). The present protocol is expedient, simple, and efficient under solvent‐free conditions. The MgO–ZrO₂ Nps are easily prepared from inexpensive precursors, and are reusable, recyclable and chemoselective. Copyright © 2012 John Wiley & Sons, Ltd.     

An efficient synthesis of anti-microbial 1,2,4-triazole-3-thiones promoted by acidic ionic liquid

Acidic ionic liquid, [(Py)₂SO][HSO₄]₂ has been used as an efficient catalyst for the reaction of ketone with thiosemicarbazide in ethanol at room temperature for the eco-friendly synthesis of spiro-1,2,4-triazolidine-3-thiones. Smooth reactions, ambient temperature, use of alcohol as a solvent, high yields, easy work-up procedure and excellent recyclability of ionic liquid and high atom economy are the auxiliary advantages of the present protocol, which makes it ecofriendly. All the synthesized 1,2,4-trioazoles were screened for antimicrobial activity. Most of compounds displayed moderate to good biological activity.     

Linear and non-linear analyses of convection in a micropolar fluid occupying a porous medium

Linear and weakly non-linear analyses of convection in a micropolar fluid occupying a high-porosity medium are performed. The Brinkman–Eringen momentum equation is considered. The linear and non-linear analyses are, respectively, based on the normal mode technique and truncated representation of Fourier series. The linear theory for a two-phase system reiterates that the preferred mode of convection is stationary as in the case of a single-phase system. An autonomous system of differential equations representing cellular convection arising in the study is considered to analyse the critical points. The Nusselt number is obtained as a function of micropolar and porous medium parameters.     

Synthesis, growth, and characterization of iminodiacetic acid monohydrochloride

The title compound of iminodiacetic acid hydrochloride (IDAAMHCL) has been successfully synthesized by adopting conventional chemical reaction and the single crystals have been grown by solvent evaporation method at room temperature and studied its various properties and reported for the first time. The lattice dimension and the crystal structure were identified from the powder X-ray diffraction analysis. The crystalline perfection assessed by high resolution X-ray diffraction technique shows that the specimen is free from structural grain boundaries. The presence of functional groups and the protons in IDAAMHCl was confirmed by Fourier transform infra-red and NMR (¹H and ¹³C) spectroscopic techniques. The presence of carbon, hydrogen, and nitrogen was confirmed by elemental analysis. The optical behavior of IDAAMHCl was assessed by UV-visible spectroscopy and it is found that there is no absorption in the entire visible region of the spectrum. The Z scan measurements at 532 nm with 5 ns laser pulses show that IDAAMHCL is a very good candidate for optical limiting applications.     

Regulation of heat transfer in Rayleigh–Bénard convection in Newtonian liquids and Newtonian nanoliquids using gravity,boundary temperature and rotational modulations

Journal of Thermal Analysis and Calorimetry - The individual effect of time-periodic gravity modulation, in-phase and out-of-phase temperature modulations and rotational modulation on...