Application of the novel (<Emphasis Type="Italic">G</Emphasis>′/<Emphasis Type="Italic">G</Emphasis>)-expansion method to construct traveling wave solutions to the positive Gardner-KP equation

The novel (G′/G)-expansion method is one of the powerful methods accredited at the present time for establishing exact traveling wave solutions to nonlinear evolution equations (NLEEs). In this article, the method has been implemented to find the traveling wave solutions to the positive Gardner-KP equation. The efficiency of this method for finding exact and traveling wave solutions has been demonstrated. The obtained solutions have been compared with the solution obtained by other methods. The solutions have also been demonstrated by figures. It has been shown that the method is straightforward and an effective tool for solving NLEES that occur in applied mathematics, mathematical physics, and engineering.     

Synthesis and characterization of N‐substituted polyaniline with mesogen molecules

The N‐substituted polyaniline (PANi) was synthesized by incorporation of bromine‐terminated mesogens onto the emeraldine form of polyaniline. Firsty three liquid crystalline molecules containing biphenyl units were synthesized. These mesogenic molecules are named as: 6‐bromo‐ (4‐hexyloxy‐biphenyl‐4′‐oxy) hexane (C₆? C₆Br), 5‐bromo‐(4‐hexyloxy‐biphenyl‐4′‐oxy) pentane (C₆? C₅Br), 6‐bromo‐(4‐octyloxy‐biphenyl‐4′‐oxy) hexane (C₈? C₆Br). Differential scanning calorimetry (DSC) in combination with polarizing optical microscopy (POM) were used to investigate the thermal properties of them. Optical microscopy showed focal conic texture characteristic of the Smectic A phase for (C₆? C₅Br) and (C₈? C₆Br). For (C₆? C₆? Br) smectic phase was determined. DSC experiments were also found in accord with mesophase formation. For the synthesis of N‐substituted polyaniline with these mesogen molecules, the emeraldine base polyaniline was reacted with BuLi to produce the N‐anionic polyaniline and then deprotonated polyaniline was reacted with bromine‐end mesogen to prepare mesogen‐substituted polyaniline through N‐substitution reaction. The degree of N‐substitution can be controlled by adjusting the molar feed ratio of mesogen to the number of repeat units of PANi. The microstructure and compositions of obtained polymers were characterized by FT‐IR, elemental analysis, DSC, and scanning electron microscopy (SEM). The cyclicvoltammetry show that the electroactivity of N‐substituted polyaniline is strongly dependent on the degree of N‐grafting. The solubility of mesogen‐substituted polyaniline in common organic solvents such as THF and chloroform was improved by increasing the degree of N‐substitution and also the samples are partially soluble in xylene. Liquid crystalline behavior of mesogen‐substituted polyanilines was investigated via POM, but no mesophase was observed. Copyright © 2008 John Wiley & Sons, Ltd.     

Catalyst-free synthesis of dihydropyridine from barbituric acid in water

An operationally simple, atom-economical, and green procedure has been developed for the synthesis of dihydropyridine derivatives by a simple condensation of barbituric acid, aldehyde, and ammonium acetate in water under catalyst-free conditions. Excellent yields and purity were obtained with only filtration and washing with hot water and ethanol.     

Well‐aligned Nano‐fiberous Membranes Based on Three‐pole Electrospinning with Channel Electrode

Three‐pole electrospinning devices integrated with a blade‐cage collector were developed to fabricate well‐aligned nano‐fiberous membranes. The proposed three‐pole configuration with a channel electrode can be a powerful tool in aligning nano‐fibers with regular diameter because the generated electric field can be accurately controlled without severe fluctuation in comparison with other methods. The three‐pole electrospinning method is also valid for industrial mass production and accurate diameter control of the aligned nano‐fibers.

     

Liquid–liquid extraction of scandium with nalidixic acid in dichloromethane

The extraction behavior of nalidixic acid (HNA) in CH₂Cl₂ has been studied for various di- and trivalent metal ions such as Cu(II), Fe(II), Ni(II), Mn(II), Sb(II), Co(II), Sc(III), Y(III), Nd(III) and Eu(III) from aqueous buffer solutions of pH 1–7 with 0.1 mol dm⁻³ nalidixic acid in dichloromethane. Separation factors of Sc(III) from these metals has shown that its clean separation is possible at pH 3.4–4. The parameters affecting the extraction of Sc(III) were optimized. The composition of the extracted adduct was determined by slope analysis method that came out to be Sc(NA)₃. Extraction of Sc(III) was studied in the presence of various cations and anions. Among the anions studied only fluoride, citrate and oxalate have significant interference whereas, Fe(III) has reduced the extraction to 53% that can be removed by using ascorbic acid as reducing agent. The proposed extraction system proved good stability up to six extraction-stripping stages for the extraction of Sc(III).     

Superparamagnetic magnesium ferrite nanoparticles: a magnetically reusable and clean heterogeneous catalyst

A highly efficient magnetically recoverable nano-catalyst was fabricated. The material synthesized has been fully characterized by vibrating sample magnetometry (VSM), X-ray powder diffraction, scanning and transmission electron microscopy, FT-IR, and the Brunauer-Emmett–Teller (BET) isotherm method. An investigation of its catalytic activity showed it to be a unique heterogeneous Lewis acid catalyst for the synthesis of α-hydroxy and α-aminophosphonates, giving a total turnover number ?450 for five consecutive runs. The catalyst is superparamagnetic having a ‘magnetization (left behind after an external magnetic field is removed)’ to ‘magnetic saturation’ ratio of about 0.0008, and thus could be easily separated by the use of an external magnetic field and was not agglomerated by exposure to magnetic fields.     

Proteomics and bioinformatics strategies to design countermeasures against infectious threat agents

The potential devastation resulting from an intentional outbreak caused by biological warfare agents such as Brucella abortus and Bacillus anthracis underscores the need for next generation vaccines. Proteomics, genomics, and systems biology approaches coupled with the bacterial ghost (BG) vaccine delivery strategy offer an ideal approach for developing safer, cost-effective, and efficacious vaccines for human use in a relatively rapid time frame. Critical to any subunit vaccine development strategy is the identification of a pathogen's proteins with the greatest potential of eliciting a protective immune response. These proteins are collectively referred to as the pathogen's immunome. Proteomics provides high-resolution identification of these immunogenic proteins using standard proteomic technologies, Western blots probed with antisera from infected patients, and the pathogen's sequenced and annotated genome. Selected immunoreactive proteins can be then cloned and expressed in nonpathogenic Gram-negative bacteria. Subsequently, a temperature shift or chemical induction process is initiated to induce expression of the PhiX174 E-lysis gene, whose protein product forms an E tunnel between the inner and outer membrane of the bacteria, expelling all intracellular contents. The BG vaccine system is a proven strategy developed for many different pathogens and tested in a complete array of animal models. The BG vaccine system also has great potential for producing multiagent vaccines for protection to multiple species in a single formulation.     

Synthesis and characterization of nanostructured-segmented block copolyetheramide based on nylon6 and poly(ethylene oxide)

<正>Segmented block copolymer based on nylon6(N6) and polyethylene oxide(PEO) with stochiometric ratio was synthesized via a two-step process.The first step represents end capping of N6 in the presence of adipic acid leading to carboxy terminated N6,and the second one is polycondensation of the latter product with PEO in the presence of catalyst and thermostabilizer to form a high molecular weight multi-block copolymer.Several methods were applied to characterize the synthesized copolymer such as Fourier transform infrared spectroscopy,proton nuclear magnetic resonance spectroscopy,differential thermal analysis,differential scanning calorimetry,X-ray diffraction and atomic force microscopy. The obtained results confirmed the multi-block structure for copolymer with a very high degree of micro-phase separation. Atomic force microscopy micrographs indicated that the morphology was the dispersion of high stiffness nanostructured polyamide(PA) domains in the amorphous region of PEO matrix,which can be very important in their performance for membrane processes.     

Synthesis,characterization and crystal structures of dinuclear macrocyclic Schiff base copper(I) complexes bearing different bridges

Utilizing a new 20-membered macrocyclic Schiff base ligand with two coordination sites formed from the [2+2] condensation of 1,3-diaminopropane and benzene-1,3-dicarboxaldehyde in the presence of CuX (X = Cl⁻, Br⁻, I⁻) salts, air-stable dicopper(I) complexes were synthesized in acetonitrile, intramolecularly linked via two halide groups, and characterized by different physico-chemical techniques. The single crystal X-ray diffraction technique indicates these complexes consist of two N₂X₂ donor sets that have distorted tetrahedral coordination environments around the copper(I) ions. In these halogen-bridged binuclear Cu₂LX₂ systems the Cu?Cu separation can be controlled, as this distance is reduced on increasing the halide size and hence the X?X repulsion, with the rigidity of the macrocycle playing a significant role.     

Fixed points of fuzzy contractive and fuzzy locally contractive maps

We establish some fixed point theorems for fuzzy contractive and fuzzy locally contractive mappings on a compact metric space with the d_∞-metric for fuzzy sets. Our results generalized well-known classical results of Edelstein.