Polypyrrole thin film fiber optic chemical sensor for detection of VOCs

A fiber optic reflectance sensor (FORS) using Polypyrrole (PPy) conducting polymer to detect volatile organic compounds (VOCs) is demonstrated. The conventional interfacial polymerization method is used to synthesize a sensitive polypyrrole membrane, which shows relatively low roughness and high reflectivity. In general the changes in electrical properties of conductive polymers are explored in sensing applications, however their optical properties have been less explored. In the present study, we evaluate the optical properties of PPy and transfer on the end face of polymer optical fiber (POF) for the detection of VOCs. The change in the reflected optical signal from PPy upon interaction with the VOCs is systematically evaluated. The fabricated PPy FORS shows the excellent sensitivity to the VOCs under test with the detection limit up to 1 ppm.     

Adoption of ICT in a government organization in a developing country: An empirical study

eGovernment initiatives all over the world endeavor to integrate Information and Communication Technologies (ICT) to transform delivery of government services to their stakeholders by improving quality of services, accountability and efficiency. In this study we explore adoption of ICT to enhance government-to-employee interactions in a government organization in a developing country. We examine this adoption behavior by utilizing the Unified Theory of Acceptance and Use of Technology (UTAUT) that provides an integrative view of user acceptance. We found that performance and effort expectancy, social influence and facilitating conditions all positively impact the use of the ICT. We did not find a significant moderating effect of gender on these relationships.     

First observation of reversible mechanochromism and chromaticity study on calcium–copper–titanate

First ever intriguing reversible mechanochromism espied in and chromaticity study on polycrystalline CaCu₃Ti₄O₁₂ composition milled up to 16 hours are reported. The composition changes its color from blackish-brown (un-milled sample)-reddish-brown (1 hours milled sample)- heina-green (6 hours milled sample)-spinach-green (16 hours milled sample) mainly due to the phase separation and corresponding change in band-gap energy on milling. The UV-Vis spectra show three observable absorption edges correspond to , , and _, d_yz transitions. A marked mechanochromic effect with crystallite size reduction is explained in the light of the difference in the site group symmetry of CuO₄ and ligand-metal charge transfer coupled with Cu²⁺ d-d transitions. The observed mechanochromism is reflected and well supported by photoluminescence spectral analysis. CIE chromaticity coordinates are located in the light blue region for an un-milled sample and violet color region for 6 hours milled sample. The profound correlation between the structural and optical properties has been revealed.     

Uniform dispersion of Ni nano particles in a carbon based catalyst for increasing catalytic activity for CH4 and H2 production by hydrothermal gasification

A carbon based nickel (Ni) catalyst was prepared by ion exchange method in which a large amount of Ni is dispersed as almost uniform nano particles. The method ion exchanges the ion exchangeable sites in an ion exchange resin with Ni followed by carbonization at 500 °C. Two different catalysts were prepared by ion exchanging Ni from an aqueous solution containing same amount of Ni ion concentration but at different pH of the solution. The amount of Ni ion exchanged in both cases was about 15%. The metal load after carbonization was about 47% and 46% in the two catalysts, respectively. The XRD pattern and TEM images of the catalysts showed that Ni particles in NiWB500 (pH = 8.8) were bigger in size in comparison to the Ni particles in NiLG500 (pH = 9.4). The BET surface area was 178 and 183 m²/g, respectively. The catalytic hydrothermal gasification (CHTG) experiments at 350 °C, 20 MPa, and 50 h⁻¹ LHSV for 50 h with organic water containing 0.2% and 2% TOC concentration showed that conversion was almost 100% with NiLG500 (pH = 9.4) catalyst and 100% and 96% with NiWB500 (pH = 8.8) catalyst, respectively. The XRD and TEM patterns of the two catalysts after 50 h gasification run showed higher sintering in NiLG500 (pH = 9.4) in which Ni particles were smaller in size.     

A simple method to design dielectric resonator‐based filters and diplexers using implicit space mapping technique

We present the design of a six pole Chebyshev filter and a cascaded quadruple dielectric resonator (DR) filter using space mapping technique. Implicit space mapping technique is used throughout and the design emerges within few iterations in both the cases. Finite element method based HFSS is used in constructing the fine model and Agilent ADS is used in constructing the coarse model. Fine details such as tuning screws are included in the fine model. The same technique is also applied to a DR‐based diplexer and is explained. In all the cases, the results obtained with the hardware match well with the analyzed results. The same procedure can be applied in designing much more complex structures such as multiplexers. © 2013 Wiley Periodicals, Inc. Int J RF and Microwave CAE 24:204–216, 2014.     

A cloned qutrit and its utility in information processing tasks

We analyze the efficacy of an output as a resource from a universal quantum cloning machine in information processing tasks such as teleportation and dense coding. For this, we have considered the $3 \otimes 3$ dimensional systems. The output states are found to be NPT states for a certain range of machine parameters. Using the output state as an entangled resource, we also study the optimal fidelities of teleportation and capacities of dense coding protocols with respect to the machine parameters and make some interesting observations. Our work is motivated from the fact that the cloning output can be used as a resource in quantum information processing and adds a valuable dimension to the applications of cloning machines.     

Structural and optical properties of inorganic–organic hybrid material of acetanilide tetrachloromercurate(II)

The crystal growth of acetanilide tetrachloromercurate(II), an inorganic–organic hybrid derivative has been achieved by solution growth through slow cooling method. The X-ray diffraction structural analysis of the hybrid material results that the compound exist in orthorhombic space group P2₁2₁2₁ with lattice parameters; a?=?13.111(2) ?, b?=?11.311(2) ?, c?=?8.355(6) ?, α?=?β?=?γ?=?90° and unit cell volume?=?1436.24 ?³. The fourier transform infrared spectroscopy profile shows that the C–C and C–N stretching modes of acetanilide ring and the observed spectra falls in mid-infrared range υ(526–2850) cm^?1. The field emission scanning electron microscope image confirms that the hybrid material has a prismatic shape with an average granular size of ~25 nm. The energy dispersive X-ray spectroscopy analyzes the elemental proportions of the hybrid materials. Transmission electron microscopy image shows the narrow distribution of nano-spatial agglomeration of secondary interactions in inorganic–organic particles. The optical band gap (Eg?=?3.75 eV) as calculated by linear fit profile of Tauc plot for allowed transition predicts that the hybrid material has potential applications in solar cells, electronic and opto-electronic devices.     

Optimization of weld bead geometry of MS plate (<Emphasis Type="Italic">Grade: IS 2062</Emphasis>) in the context of welding: a comparative analysis of GRA and PCA–Taguchi approaches

In the last few decades, researchers proceeded their foot for analyzing the weld characteristic index of materials since the development of novel materials began tremendously. Presently, evaluation of the optimum synchronization among considered input factors for materials are even now surviving into ill-defined mode; soliciting novel mathematical models as well as robustly designed decision support systems that could effectively handle nonpartial information (experimental data). In the present reporting, multiobjective optimization dilemmas have been answered in metal inert gas (MIG) welding process using MS plate (Grade: IS 2062) specimen. The considered specimen was checked to harmonize the optimum setting between input factors, for example, welding current, open circuit voltage, and thickness of plate, with respect to obtaining prosperous weld strength as well as bead geometry quality characteristics, for example, tensile strength, bead width, reinforcement, penetration, and dilution. In the present research work, the Taguchi’s L₉ orthogonal array (OA) design was preferred to conduct the experiments on MS plate (Grade: IS 2062) specimens in the domain of MIG welding process. Thereafter, the evaluated multiple objectives transformed into a single response via exploration of grey relation analysis (GRA) and principal component analysis (PCA) approaches to determine the optimum setting between input factors. Next, the outset of signal-to-noise ratio (S/N ratio) along with Analysis of variance (ANOVA) productively was utilized to determine the priority weights against the defined input factors (significant factor). The significant contribution of the present report was to propose a robustly designed decision support system that could assist the readers/researchers to resolve the discussed problems.     

Interpretation of Association Behavior and Molecular Interactions in Binary Mixtures from Thermoacoustics and Molecular Compression Data

Density and acoustic velocity were measured for binary liquid mixtures of formamide, N-methylacetamide (NMA), dimethylformamide (DMF), and dimethylacetamide (DMA) with acetonitrile at atmospheric pressure and 293.15 K, 298.15 K, 303.15 K, 308.15 K, or 313.15 K over the concentration range 0.12 to 0.97. Models assuming association and nonassociation of the components of the mixtures were used to predict the behavior of the studied liquids, which would typically show weak interactions. The measured properties were fitted to the Redlich–Kister polynomial to estimate the binary coefficients and standard errors. The data were used to study the molecular interactions in the binary mixtures. Furthermore, the McAllister multibody interaction model was used to correlate the properties of the binary liquid mixtures. Testing of the nonassociation and association models for the different systems showed that, compared with the nonassociation model theoretical results, the association model theoretical results were more consistent with the experimental results.