Exploring a reversible NOR from a 4 × 4 modified Fredkin gate and its optical mapping using a LiNbO3-based MZI

Journal of Computational Electronics - The extensive search for the implementation of reversible logic using emerging technologies has paved the way for the rise of optical computing. The...     

Conduction nature of conical pores in PET membrane

Summary The preparation of conical pores in polyethylene terepthlate (PET) membrane is described. The conical pores prepared in PET by track etching technique. For this purpose, Cl⁹⁺ ion irradiated film was placed into an electrolytic cell and etched from one side while other side of membrane was protected by a stopping medium. During etching, current was recorded as a function of time, which shows a sudden change, indicating the pores breakthrough. After breakthrough, the etch process is interrupted by replacing the etching solution. After etching, the current voltage characteristics were determined under symmetric bath conditions. The resulting conical pores show non ohmic behavior, similar to that of an electronic diode.     

Microwave permittivity of MWCNT,Ca1 − xBaxBi2Nb2O9 (0 ≤ x ≤ 1) and MWCNT/ Ca1 − xBaxBi2Nb2O9 (0 ≤ x ≤ 1) layered composite thick films using microstrip ring resonator overlay method

Journal of Electroceramics - The microwave dielectric properties of the multiwalled carbon nanotubes (MWCNT) thick film, Ca1???xBaxBi2Nb2O9 (x?=?0, 0.2, 0.4, 0.6, 0.8,...     

Broadening of Photonic Band Gap in a One—Dimensional Superconductor Star Waveguide Structure

The present paper describes the theoretical investigation of enlarged reflection bands (photonic band gaps) in a 1D star waveguide (SWG) structure consists of superconductor and dielectric as its constituent materials. For the present study, we take the different combinations of superconductor and dielectric materials as a backbone and side branches of the SWG structure. In order to obtain the dispersion relation, Interface Response Theory (IRT) has been employed. Photonic band gaps of SWG structure having superconductor?Csuperconductor, superconductor?Cdielectric, and dielectric?Csuperconductor materials are compared with the band gaps of the conventional photonic crystal (PC) structure having superconductor?Csuperconductor and dielectric?Csuperconductor materials. Analysis of the dispersion characteristics shows that there exists no band gaps for conventional PC when both layers are made of the same superconducting materials (as the usual case) while the SWG structure shows forbidden bands of finite width even the backbone and side branches are made of same materials. Also, the SWG structure having superconductor?Cdielectric shows the wider reflection bands in comparison with the structure having dielectric?Csuperconductor as its constituent materials, while for the conventional PC structure it is same in both the cases. Further, the effect of temperature and the effect of variation of number of grafted branches on the photonic bands of SWG structure have been studied.     

Fused Deposition Modeling of Polyolefins: Challenges and Opportunities

Polyolefins are the largest class of commercially available synthetic polymers that are extensively used in a variety of applications from commodities to engineering owing to their low cost of production, good physico-mechanical properties, light weight, good processability, and recyclability. Compared to conventional molding techniques, fused deposition modeling (FDM)-based 3D printing is a smart manufacturing technology for thermoplastics due to its low cost, ease of production of complex geometrical parts, rapid prototyping, and scalable customization. FDM 3D printing can be an ideal manufacturing technology for polyolefins to manufacture various complex parts. However, FDM 3D-printing of polyolefins is challenged bycritical printing problems like high warpage, dimensional inaccuracies, poor bed adhesion, and poor layer-to-layer adhesion. In this review, a fundamental understanding of polyolefins and their FDM 3D-printing process is established, and the recent progress of FDM 3D printing of polyolefins is summarized. Furthermore, strategies to overcome warpage and to improve mechanical strength of the 3D-printed polyolefins are provided. Finally, future prospectives of FDM 3D-printing of polyolefins are critically discussed to inspire prospective research in this field. It is believed that this review article can be tremendously useful for research work related to FDM of polyolefin-based materials.     

Design framework for dimethyl ether (DME) production from coal and biomass-derived syngas via simulation approach

A comprehensive thermodynamic study was conducted to evaluate the comparative efficacy of methanol and dimethyl ether (DME) synthesis using CO₂ rich syngas feed. The first part of our study included assessing the relative performances of the methanol synthesis system, two step DME synthesis system, and one step DME synthesis system in terms of the CO_x conversion and product yield (methanol/DME) based on the Gibbs free energy minimization approach. The wide range of composition of CO₂-enriched syngas feed produced by the coal and biomass gasification was simulated using Aspen Plus and the following evaluation parameters were analyzed for a broad parameter range: reaction temperature (180–280°C), reaction pressure (10–80 bar), stoichiometry number (SN) (0–11), and CO₂/(CO₂ + CO) molar feed ratio (0–1) for isothermal as well as adiabatic conditions. Based on the equilibrium yield, one-step DME synthesis was discovered as the most viable process to utilize the co-gasification derived syngas effectively. In the second part of our study, the overall process efficiency was inspected through the process design of 1 tonnes per day (TPD) DME plant inclusive of heat integration, resulting in significant CO₂ abatement and DME production with high product purity and minimum energy consumption. Consequently, one-step DME production via CO₂-enriched syngas obtained through the coal or biomass gasification process is identified as the leading technology based on energy utilization and CO₂ abatement.     

Effect of pre‐treatments on the biosorption of Chromium (VI) ions by the dead biomass of Rhizopus arrhizus

BACKGROUND: This work fulfils the need to develop an eco‐friendly biosorbent, elucidating the mechanism of biosorption. Removal of Cr(VI) by Rhizopus arrhizus was investigated in batch mode. Enhancement in the performance of the biosorbent was attempted by pre‐treating the biomass with inorganic and organic acids, chelating agent, cross‐linker and an organic solvent followed by autoclaving. The surface characterization of the biomass was carried out by potentiometric titration, surface area analysis, infrared spectroscopy, chemical modification of the biomass and scanning electron microscopy. RESULTS: All the physico‐chemical treatments of the biosorbent improved Cr(VI) uptake compared with the native biomass (21.72 mg g^?1). The highest biosorption capacity (31.52 mg g^?1) was achieved after pre‐treating the biomass with 0.5 mol L^?1 HNO₃ followed by autoclaving. Surface characterization of the biomass using pH_zpc, potentiometry and Fourier transform infrared (FTIR) analysis revealed the role of amino and carboxyl groups in Cr(VI) removal by electrostatic attraction. Chemical modification of amino and carboxyl groups significantly decreased Cr(VI) uptake capacity confirming their role in biosorption. SEM analysis showed adsorption of Cr(VI) on the biosorbent surface. CONCLUSION: Rhizopus arrhizus biomass proved to be an effective and low cost alternative biosorbent for removal of Cr(VI) from aqueous solutions. Copyright © 2011 Society of Chemical Industry     

Investigation of water vapor permeability and antimicrobial property of zinc oxide nanoparticles‐loaded chitosan‐based edible film

This study is focused on the investigation of moisture uptake properties of chitosan films. The GAB isotherm model is found to fit well to the experimental moisture uptake data obtained at 10, 25, and 37°C. The water vapor permeability is found to increase with temperature. The use of plasticizer enhances the water vapor permeability. Finally, the films have been loaded with ZnO nanoparticles and characterized by X‐ray diffraction, differential scanning calorimetry, surface plasma resonance, and scanning electron microscopic analyses. The crystal size as determined using Scherrer's equation is found to be around 15 nm. The films have shown excellent antibacterial action against the model bacterium Escherichia coli. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Corrosion inhibition of mild steel in acidic medium by poly (aniline-co-<Emphasis Type="Italic">o</Emphasis>-toluidine) doped with <Emphasis Type="Italic">p</Emphasis>-toluene sulphonic acid

The corrosion behaviour of mild steel in 0.5 M H₂SO₄ solution containing various concentrations of a p-toluene sulphonic acid doped copolymer formed between aniline and o-toluidine was investigated using weight loss, polarization and electrochemical impedance techniques. The copolymer acted as an effective corrosion inhibitor for mild steel in sulphuric acid medium. The inhibition efficiency has been found to increase with increase in inhibitor concentration, solution temperature and immersion time. Various parameters like E _a for corrosion of mild steel in presence of different concentrations of inhibitor and ΔG _ads, ΔH ⁰, ΔS ⁰ for adsorption of the inhibitor, revealed a strong interaction between inhibitor and mild steel surface. The adsorption of this inhibitor on the mild steel surface obeyed the Langmuir adsorption equation.     

Structural,morphological, and magnetic properties of ZnxCo1-xFe2O4 (0 ≤ x ≤ 1) prepared using a chemical co-precipitation method

In the present study, the chemical co-precipitation technique was adopted to synthesize Zn_xCo_1-xFe₂O₄ (ZCF) (0?≤ x?≤?1) ferrites. The thermogravimetric-differential thermal analysis results revealed that above 405?°C, the precursor had decomposed and ferrite formation had occurred. The structure and morphology of the prepared ferrite nanoparticles were investigated using X-ray diffraction, Fourier transform infrared spectroscopy, and field emission scanning electron microscopy (FE-SEM). The synthesized polycrystalline nanoparticles had a cubic spinel structure and the crystallite size was in the range of 6.09–12.98?nm. The prepared ferrites appeared as nearly spherical nanoparticles with a particle size in between 0.13 and 0.23?µm, as confirmed using FE-SEM. The elemental composition was determined using the energy-dispersive X-ray spectroscopy technique. The influence of the Zn-substituted cobalt ferrites (ZCF) on the structural, morphological, and magnetic properties were studied. The magnetic properties of the ZCF samples such as saturation magnetization, remanence magnetization, and coercivity measured at room temperature were 0.387–2.065?emu/g, 0.057–1.282?emu/g, and 60–1834?Oe, respectively. It was confirmed from the nature of the hysteresis loops that the given ZCF samples can be considered as a soft magnetic material.