Effect of SO<Subscript>4</Subscript> <Superscript>2-</Superscript>, Cl<Superscript>–</Superscript> and NO<Subscript>3</Subscript> <Superscript>-</Superscript> anions on the formation of iron oxide nanoparticles via microwave synthesis

In the present work iron oxide nanoparticles have been prepared by microwave assisted synthesis with the influence of different precursor salts and synthesis of magnetite, hematite, Iron oxide hydroxide and maghemite nanoparticles. Synthesized iron oxide nanoparticles were characterized with Infrared Spectroscopy (FTIR), Field Emission Scanning Electron Microscopy (FESEM), and Energy-dispersive X-ray Spectroscopy (EDX). XRD measurements show that the peaks of diffractogram are in agreement with the theoretical data of magnetite, hematite, FeO(OH) (Iron oxide hydroxide) and maghemite. Crystallite size of the particles was found to be 33, 45, 36 and 43.5 nm for Fe₃O₄, α-Fe₂O₃, FeO(OH) and γ-Fe₂O₃. FESEM studies indicated that size of the particles is observed in the range of about 19.4 to 46.7 nm (Fig. 2a, average 32 nm), 29.1 to 67.6 nm (Fig. 2b average 45 nm), 29.1 to 40.8 (Fig. 2c average 36.6 nm), 29.1 to 80 nm (Fig. 2d average 43.5) for Fe₃O₄, α-Fe₂O₃, FeO(OH) and γ-Fe₂O₃ respectively. EDX spectral analysis reveals the presence of carbon, oxygen, iron in the synthesized nanoparticles. The FTIR graphs indicated absorption bands due to O–H stretching, C–O bending, C–H stretching and Fe–O stretching vibrations.     

Tuning the optical properties of poly(o-phenylenediamine-co-pyrrole) via template mediated copolymerization

Tailoring of conjugated monomers via copolymerization is a facile method to obtain tunable spectral, morphological and optical properties. To investigate the effect of copolymerization of pyrrole with o-phenylenediamine on the optoelectronic properties of the synthesized copolymers, the present work reports the synthesis of copolymers of o-phenylenediamine with pyrrole with varying mol ratios via chemical polymerization in methylene blue (MB) medium. Copolymerization was confirmed by Fourier transform infrared spectroscopy and ultraviolet-visible studies. Ultraviolet-visible spectroscopy revealed variation in the optical properties with the change in the monomer ratio. Fluorescence studies showed that the copolymer containing 80% poly(o-phenylenediamine) revealed highest quantum yield among all the copolymers. The emission color could therefore be tuned by careful selection of narrow band co-monomers, which could help in designing tunable fluorescence emitting materials for potential application in OLED devices.     

Optimization of process parameters for ultrasonic drilling of advanced engineering ceramics using the Taguchi approach

The effect of process parameters on the cutting ratio (ratio of material removal rate to tool wear rate) for ultrasonic drilling of alumina-based ceramics using silicon carbide abrasive was studied. The parameters considered were workpiece material, tool material, grit size of the abrasive, power rating, and slurry concentration. Taguchi’s optimization approach was used to obtain the optimal parameters. The significant parameters were identified and their effects on cutting ratio were studied. The results obtained were validated by conducting confirmation experiments.     

Taguchi’s optimization of process parameters for production accuracy in ultrasonic drilling of engineering ceramics

This paper presents a study of the effect of process parameters on production accuracy obtained through ultrasonic drilling of holes in alumina based ceramics using silicon carbide abrasive. Production accuracy in ultrasonic drilling involves both dimensional accuracy (hole oversize) and form accuracy (out-of-roundness and conicity). The parameters considered are workpiece material, tool material, grit size of the abrasive, power rating and slurry concentration. Taguchi’s optimization approach is used to obtain the optimal parameters. The significant parameters are also identified and their effect on oversize, out-of-roundness and conicity are studied. The results obtained are validated by conducting the confirmation experiments.     

A review on the chemical and electrochemical copolymerization of conducting monomers: recent advancements and future prospects

ABSTRACT

Synthesis of conducting polymers via copolymerization has attracted considerable attention because of their outstanding synergistic properties that can be tailored as per the requirement to produce a wide variety of functional polymers. The objective of this review is to provide insight about the unique characteristics of copolymers of conducting polymers that have been developed over the past few decades and have found potential application in solar cells, anticorrosive coatings, LEDs etc.     

Multi-area Environmental Economic Dispatch with Reserve Constraints Using Enhanced Particle Swarm Optimization

In this paper, the multi-area environmental economic dispatch (MAEED) problem with reserve constraints is solved by proposing an enhanced particle swarm optimization (EPSO) method. The objective of MAEED problem is to determine the optimal generating schedule of thermal units and inter-area power transactions in such a way that total fuel cost and emission are simultaneously optimized while satisfying tie-line, reserve, and other operational constraints. The spinning reserve requirements for reserve-sharing provisions are investigated by considering contingency and pooling spinning reserves. The control equation of the particle swarm optimization (PSO) is modified by improving the cognitive component of the particle's velocity using a new concept of a preceding experience. In addition, the operators of PSO are dynamically controlled to maintain a better balance between cognitive and social behavior of the swarm. The effectiveness of the proposed EPSO has been investigated on four areas, 16 generators and four areas, 40 generators test systems. The application results show that EPSO is very promising to solve the MAEED problem.     

Protein F1 is required for efficient entry of Streptococcus pyogenes into epithelial cells

1. Repeated pinching at the scruff produces, in experimental test/retest sessions, prolonged cataleptic-like immobility in mice that may mimic immobilities seen in some natural situations. 2. In the first experiment, on male mice, imipramine and amitriptiline (20 and 30 mg/kg i.p.) augmented the number of pinches necessary to reach the criterion of induced catalepsy and reduced the total time of catalepsy. 3. In the second experiment, on female mice, compounds that modulate the central 5-HT transmission, like fluvoxamine, fluoxetine (20 mg/kg i.p.) and ondansetron (0.1 and 1 mg/kg i.p.), retarded the occurrence and shortened the duration of pinch induced catalepsy at doses that did not modify the open field performances. Maprotiline (a selective inhibitor of the NA reuptake) did not modify the mice's performances in respect to controls. 4. Female mice presented a more rapid occurrence and a prolonged duration of pinch-induced catalepsy in respect to male controls. The present behavioral test may become a simple experimental model to detect new antidepressant or anxiolytic compounds and the significant sex difference could make the test a more useful tool in investigating anxiety behaviour in rodents.     

Silver ferrite and cobalt ferrite dispersed castor oil polyurethane nanocomposites: Quenching studies of bovine serum albumin

The use of renewable resource is a strategic opportunity to meet growing demands of eco-friendly materials. The present study reports the synthesis of castor-oil-based polyurethane (COPU), and its nanocomposites with CoFe₂O₄ and AgFeO₂ via sonication technique. Formation of the nanocomposite was confirmed by IR analysis while UV–visible studies revealed encapsulation of the ferrite particles by COPU. The interaction between COPU, AgFeO₂, CoFe₂O₄, and their nanocomposites with bovine serum albumin (BSA) was also investigated by fluorescence spectroscopy which revealed static quenching of BSA through complex formation. The quenching rate for COPU was determined to be 1.98?×?10⁴?LM^?1 while for pure CoFe₂O₄ and AgFeO₂, it was found to be 3?×?10⁴?LM^?1 and 3.2?×?10⁴?LM^?1, respectively. The interaction of BSA particularly with silver and cobalt ferrite nanoparticles within COPU matrix was found to be promising. It was found that by controlling the loading of ferrite in COPU matrix, desired binding could be achieved.     

Extended Release of Theophylline Through Sodium Alginate Hydrogel Beads: Effect of Glycerol on Entrapment Efficiency,Drug Release

Theophylline is the most useful bronchodilators for the treatment of severe reversible bronchospasm. The fluctuations of serum theophylline level in clinical practice and associated central nervous system side effects necessitate the development of an extended release formulation. In the present study, theophylline-loaded beads were prepared by extruding the dispersion of theophylline, sodium alginate, and glycerol into the cationic crosslinking solution of calcium chloride. The effect of the addition of glycerol was determined by entrapment efficiency, drug release, and morphology of beads. Absence of chemical interaction between drug, polymer, and counterions after production of beads was confirmed by Fourier transform infrared spectroscopy. Theophylline entrapment of up to 72% was achieved in beads with almost spherical shape and size ranging from 0.67 to 1.12 mm. Percentage entrapment of theophylline found to be more and release was extended up to the eleventh hour from the glycerol containing sodium alginate beads. Hence, sodium alginate glycerol beads could represent a promising oral drug delivery system to extend the release of theophylline.