An Energy Efficient OFDM–MIMO Systems for Multimedia Data Transmission Based on Hybrid Fuzzy Approach

Wireless Personal Communications - At present the low cost, low power and collaborative feature of Wireless Sensor Network (WSN) is becoming a popular communication technology in smart grid...     

Prevention of Scum Formation and Entrapment in High Carbon Steel Billets

Gradual build-up of scum over the liquid steel surface in the mould gives rise to entrapped exogenous inclusions and slag patch in the cast billets. The problem is more commonly observed during the open stream casting of continuous casting of high carbon (C > 0.6 mass%) steel billets. This problem has been quite commonly observed at Tata Steel during its billet casting. Present work aimed at eliminating the problem of scum formation during open stream billet casting of high carbon steel billets. This work involved experiments in the laboratory as well as in the plant. In addition, based on liquid steel composition thermodynamic calculations were carried out for predicting the possible oxide inclusions in Mn-Si deoxidised steels. Water model experiments were carried out in a full-scale billet caster physical model for investigating the influence of tundish outlet nozzle alignment on the entrapment of scum as slag patch over the billet surface. Based on these, cause of scum formation and its exact mechanism of entrapment in cast billets were established. Finally, countermeasures were recommended to the plant. Adequacy of the proposed countermeasures was established through a series of trials in the plant before implementation. Improvement obtained from the implementation over a period of time has been reported in the paper.

     

Study of mechanism of enhanced antibacterial activity by green synthesis of silver nanoparticles

The extensive use of silver nanoparticles needs a synthesis process that is greener without compromising their properties. The present study describes a novel green synthesis of silver nanoparticles using Guava (Psidium guajava) leaf extract. In order to compare with the conventionally synthesized ones, we also prepared Ag-NPs by chemical reduction. Their optical and morphological characteristics were thoroughly investigated and tested for their antibacterial properties on Escherichia coli. The green synthesized silver nanoparticles showed better antibacterial properties than their chemical counterparts even though there was not much difference between their morphologies. Fourier transform infrared (FTIR) spectroscopic analysis of the used extract and as-synthesized silver nanoparticles suggests the possible reduction of Ag(+) by the water-soluble ingredients of the guava leaf like tannins, eugenol and flavonoids. The possible reaction mechanism for the reduction of Ag(+) has been proposed and discussed. The time-dependent electron micrographs and the simulation studies indicated that a physical interaction between the silver nanoparticles and the bacterial cell membrane may be responsible for this effect. Based on the findings, it seems very reasonable to believe that this greener way of synthesizing silver nanoparticles is not just an environmentally viable technique but it also opens up scope to improve their antibacterial properties.     

Phase equilibria in the system Sm–Rh–O and thermodynamic and thermal studies on SmRhO3

Using isothermal equilibration, phase relations are established in the system Sm–Rh–O at 1273 K. SmRhO₃ with GdFeO₃-type perovskite structure is found to be the only ternary phase. Solid-state electrochemical cells, containing calcia-stabilized zirconia as an electrolyte, are used to measure the thermodynamic properties of SmRhO₃ formed from their binary component oxides Rh₂O₃ (ortho) and Sm₂O₃ (C-type and B-type) in two different temperature ranges. Results suggest that C-type Sm₂O₃ with cubic structure transforms to B-type Sm₂O₃ with monoclinic structure at 1110 K. The standard Gibbs energy of transformation is $ \Delta_{\text{tr}} G^{\text{o}} ( \pm 87)/{\text{J}}\,{\text{mol}}^{ - 1} = 3763 - 3.39\,(T/{\text{K}}) $ . Standard Gibbs energy of formation of SmRhO₃ from binary component oxides Rh₂O₃ and Sm₂O₃ with B-type rare earth oxide structure can be expressed as $ \Delta_{\text{f(ox)}} G^{\text{o}} ( \pm 75)/{\text{J}}\,{\text{mol}}^{ - 1} = - 64230 + 6.97(T/{\text{K}}) $ . The decomposition temperature of SmRhO₃ estimated from the extrapolation of electrochemical data is 1665 (±2) K in air and 1773 (±3) K in pure oxygen. Temperature-composition diagrams at constant oxygen pressures are constructed for the system Sm–Rh–O. Employing the thermodynamic data for SmRhO₃ from emf measurement and auxiliary data for other phases from the literature, oxygen potential-composition phase diagram and 3-D chemical potential diagram for the system Sm–Rh–O at 1273 K are developed.     

Thermal characterization of diglycidyl ether of bisphenol‐A/phosphorus containing amines

In order to improve the thermal resistance of diglycidyl ether of bisphenol‐A (DGEBA), phosphorus‐containing di‐ and tri‐amines, i.e., bis (3‐aminophenyl) methyl phosphine oxide (B) and tris (3‐aminophenyl) phosphine oxide (T), were used as curing agents. The effect of phosphorus content on the curing characteristics and char residue of cured resins in nitrogen atmosphere was evaluated by using different molar ratios of conventional curing agent, i.e. 4, 4′‐diaminodiphenyl sulfone (D) and amine B or T. Activation energy of curing, as evaluated by using the multiple heating rate method, was lowest when triamine T (61.0 kJmol^?1) was used as hardener and was highest when D (68.7 kJmol^?1) was used. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 390–395, 2001     

Recent advances in extending the shelf life of fresh Agaricus mushrooms: a review

Postharvest browning of Agaricus mushrooms is a severe problem that reduces the shelf life of harvested mushrooms because of their continued respiration and biochemical activity. There are no simple answers and no single treatment is known to limit overall quality deterioration. However, there are several strategies that are being implemented in order to reduce the rate of respiration for mushrooms. Packaging technology is the common denominator that allows us to implement these strategies and thus is key to quality preservation. In this review, first, the major factors involved in postharvest quality deterioration are discussed and then technological advances/methods used to counteract these hurdles are presented. Copyright © 2010 Society of Chemical Industry     

Assessment of otolith function using cervical and ocular vestibular evoked myogenic potentials in individuals with motion sickness

The involvement of otolith organs in motion sickness has long been debated; however, equivocal findings exist in literature. The present study thus aimed at evaluating the otolith functioning in individuals with motion sickness. Cervical and ocular vestibular evoked myogenic potentials were recorded from 30 individuals with motion sickness, 30 professional drivers and 30 healthy individuals. The results revealed no significant difference in latencies and amplitudes between the groups (p>0.05). Nonetheless, thresholds were significantly elevated and inter-aural asymmetry ratio significantly higher in motion sickness susceptible group (p < 0.001) for both the potentials. All the individuals in the motion sickness group had high asymmetry ratio at least on one of the two potentials. Thus, reduced response and/or asymmetric otolithic function seem the likely reasons behind motion sickness susceptibility.     

Knowledge building through optimized classification rule set generation using genetic based elitist multi objective approach

Knowledge building is an important activity taken up by various organizations. The paper exemplifies the creation of a knowledge-centric environment for a non-profit sector such as a higher education. Building knowledge and thereafter using it are important aspects of knowledge-centric environment; this further helps the organization to gain competitive advantage. With the increase in popularity of genetic algorithm (GA), the technique has been used in building efficient classifiers for creating effective rule sets. The paper makes use of multi-objective genetic algorithm for building GA-based efficient classifier because classification rule mining is itself, a multi-objective problem. Knowledge expressed through classification rules help in establishing relationships between attributes that are not visible openly. The study assumes importance as curriculum planning is an important aspect of any academic institution, the knowledge derived in the form of rules residing in the knowledge base help to substantiate proper curriculum development, making a sizeable contribution toward professional growth and advancement of the students. On implementation of the findings, educational organizations will be able to institute themselves as knowledge centric.

     

The thermal gravimetric studies for polymer samples of polyvinyl chloride (PVC) and polyvinyl alcohol (PVA) obtained by treatment with ionic liquid [bmim]Br

The development related to the effective degradation or recycling of polymeric material are of high priority in research because of solid waste removal problems in the environment and to establish sustainable conditions. Ionic liquids having low vapour pressure and other useful properties are finding increasing applications in the field of polymer science. In the present report, we describe the studies related to the plasticizing effect of simple 1-butyl-3-methyl-imidazolium bromide (an ionic liquid) on polyvinyl chloride. The admixtures of PVC and IL were subjected to heating (353–453 K) as a function of time (1–7 h). The resulting product stability was studied by TGA. Similar studies were carried out with PVA via glycolysis, i.e. in presence of ethylene glycol and products obtained were studied by TGA. Our results indicate that the addition of ionic liquid stabilizes the polyvinyl chloride and prevents liberation of HCl, while the polyvinyl alcohol gets degraded rapidly. These findings support the hypothesis of solubilization and degradation depending upon structural characteristics of polymeric molecules. The implications of these findings are discussed in terms of electrostatic, ion dipole and H-bonding interactions within polymer molecules influenced by thermal energy effects.