Involvement in emergency supply chain for disaster management: a cognitive dissonance perspective

An integrated process, interlinked operation and interoperable communication network amongst operating agencies are critical for developing an effective disaster management supply chain. The traditional managerial problems observed across disaster management operations are: non-cooperation among members, disrupted chain of commands, misuse of relief items, lack of information sharing, mistrust and lack of coordination. This study aims to understand the issues affiliated with negative attitude towards disaster management operations using theory of cognitive dissonance. A qualitative investigation was undertaken across 64 districts in Bangladesh. Five constructs were examined for their influences on attitude and behavioural intention of members participating in government emergency supply chain for disaster management. The results indicate that administrative conflict, political biasness and professional growth have significant effects on attitude. Impact of insecurity is non-significant on attitude. This research offers substantial theoretical contribution to the cognitive dissonance theory in the context of disaster management supply chain.     

Strategical parametric investigation on manufacturing of Al–Mg–Zn–Cu alloy surface composites using FSP

Friction stir processing (FSP) is a unique approach being presently researched for composite fabrication. In the present investigation, Al-B₄C surface composite was fabricated through FSP by incorporating B₄C powder particles into Al–Mg–Zn–Cu alloy (AA 7075) matrix. The influence of varying powder particle reinforcement strategies on the microstructure, powder distribution, microhardness, and wear resistance of the surface composite is reported. In addition, AA 6061/B₄C composites were prepared using the same parameter set and the powder distribution in the composite was compared to that in the AA 7075/B₄C composite. More homogeneous dispersion of B₄C powder was observed in AA 6061 as compared to AA 7075 substrate. Among the prepared AA 7075/B₄C composites, the best B₄C powder distribution was detected in samples processed using fine powder and incorporating the change in stirring direction between passes. The hardness and wear resistance of the prepared composites were almost doubled attributing to several strengthening mechanisms and B₄C powder distribution in the AA 7075 matrix.     

Dual role of activated carbon as fuel and template for solution combustion synthesis of porous zinc oxide powders

In this work, nanosized zinc oxide (ZnO) powders were fabricated by urea–nitrate solution combustion synthesis using activated carbon as a structure-directing template and secondary fuel at different fuel–oxidant ratios. The as-synthesized powders were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), N₂ adsorption–desorption measurements, UV–Vis diffuse reflectance spectroscopy, and photoluminescence. The effect of fuel amount on photocatalytic activity of ZnO powders was evaluated by the degradation of an azo dye Orange G. It was observed that combustion synthesis with activated carbon as a secondary fuel had a profound effect on reducing crystallite size and enhancement of specific surface area. The crystallite size of the as-synthesized powders varied from 46 to 26 nm. The ZnO powder prepared at a fuel–oxidant ratio of 1.8 possessed the small crystallite size and high specific surface area of 69 m²/g. It correspondingly resulted in the highest dye removal percentage of 99% with a rate constant of 0.027 min⁻¹. The improvement in dye degradation can be due to the synergistic interaction and interplay of enhanced surface area and catalytic ability of the photocatalyst. This study provides a simple single-step synthesis methodology to produce metal oxide nanopowders with tunable surface properties for high potential applications in catalysis, optoelectronics, and gas sensors.     

Chondrogenic stimulation in mesenchymal stem cells using scaffold-based sustained release of platelet-rich plasma

Developing minimal invasive strategies via injectable hydrogels for effective repairing of cartilage defects is highly desired. Injectable hydrogels, which can simultaneously embed cell and growth factors (GFs), serve as in situ formed scaffolds and could support an accelerated tissue regeneration process. The purpose of this study is to fabricate a composite injectable hydrogel, based on alginate (Alg)/polyvinyl alcohol (PVA) incorporating platelet rich plasma (PRP)-encapsulated Alg sulfate (AlgS) microbeads, as a localized sustained release system of GFs, for the articular cartilage regeneration. The results show that synthesized AlgS microbeads support the sustained release of PRP GFs during 14 days, where preserve the bioactivity of them more than the free PRP. Rabbit adipose-derived mesenchymal stem cells in contact with PRP-loaded AlgS beads show more proliferation (2.7 folds) and have obviously higher deposition of collagen type ΙΙ and GAGs than free PRP treated ones. In addition, cells encapsulated into the hydrogel including PRP sustained release system show upregulated expression of collagen type ΙΙ (61 folds), Aggrecan (294 folds) and SOX9 (71.5 folds), as cartilage-critical genes, compared to the direct treatment by PRP. To summarize, the developed hybrid Alg/PVA hydrogel embedding with PRP-encapsulated AlgS microbeads is suggested as a potential in situ formed scaffold for cartilage regeneration.     

Analysis of particulate pollution on foodstuff and other items by environmental scanning electron microscopy

Combustion processes commonly create fine and ultrafine particles whose effects are often harmful to human health. The present study is aimed at providing more data in this field by testing the capability of environmental electron scanning microscopy of detecting and analyzing such particles. For this purpose, we examined a range of samples taken from everyday food items collected in Tuscany. The results showed that, within the examined samples, inorganic particles can be observed in the nano- and micrometer range. These particles are attributable mostly to natural processes and, in part, to food processing. Little evidence is found for particles whose origin could be attributed to industrial combustion processes, such as waste incineration.     

Ultrasensitive Nanosensor for Detection of Malic Acid in Tomato as Fruit Ripening Indicator

Malic acid is an important fruit ripening indicator. Fruit industry losses every year due to non-availability of rapid technology for early detection of ripening of fruits. Therefore, nanosensor was developed for detection of malic acid concentrations in tomato at early stage of ripening before transport to the market. The enzyme NADP-malate dehydrogenase (Malic enzyme) was covalently immobilized on to screen printed carboxylated-multiwall carbon nanotubes working electrode using EDC-NHS chemistry. The enzyme electrode was characterized using scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectroscopy. The immobilized enzyme/c-MWCNT electrode was used for amperometric determination of different concentrations of malic acid in tomato using differential pulse voltammogram (DPV) at scan rate of 100 mv/s. The limit of detection of malic acid was 0.01 mM. The nanosensor showed low K_m (0.12 mM), less response time (2 min), high sensitivity (0.01 mM) and better storage stability 180 days at 4 °C compared to earlier reported malate biosensor. The nanosensor was also validated at different stages of ripening of tomato using enzymatic method.

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Graphical Abstract Nanosensor for detection of malic acid in tomato

     

A new method for higher-order linear phase FIR digital filter using shifted Chebyshev polynomials

In this work, a new method for the design of linear phase finite impulse response (FIR) filters using shifted Chebyshev polynomial is proposed. In this method, magnitude response of FIR filter is approximated with the help of shifted Chebyshev polynomials. The number of polynomials used for approximation depends upon the order of filter. Design problem of filter is constructed as minimization of integral mean-square error between the ideal response and actual response through differentiating it with respect to its coefficients, which leads to a system of linear equations. The simulation results included in this paper show the efficiency of proposed method. It is also evident from the results that the proposed method is suitable for higher filter taps.     

Imprinting of Local Metallic States into VO2 with Ultraviolet Light

Materials exhibiting electronic phase transitions have attracted widespread attention. By switching between metallic and insulating states under external stimuli, the accompanying changes in the electrical and optical properties can be harnessed in novel electronic and optical applications. In this work, a laterally confined conductive pattern is inscribed into an otherwise insulating VO₂ thin film using ultraviolet light, inducing an almost four orders of magnitude decrease in electrical resistivity of the exposed area. The metallic imprint remains in VO₂ after ultraviolet light exposure and can be completely erased by a short low temperature anneal. The ability to optically pattern confined metallic structures provides new opportunities for reconfigurable photonic and plasmonic structures, as well as re‐writable electric circuitry.     

Design and structural optimization of junctionless FinFET with Gaussian-doped channel

A junctionless (JL) fin field-effect transistor (FinFET) structure with a Gaussian doping distribution, named the Gaussian-channel junctionless FinFET, is presented. The structure has a nonuniform doping distribution across the device layer and is designed with the aim of improving the mobility degradation caused by random dopant fluctuations in JL FinFET devices. The proposed structure shows better performance in terms of ON-current (\(I_{\mathrm{ON}}\)), OFF-current (\(I_{\mathrm{OFF}}\)), ON-to-OFF current ratio (\(I_{\mathrm{ON}}{/}I_{\mathrm{OFF}}\)), subthreshold swing, and drain-induced barrier lowering. In addition, we optimized the structure of the proposed design in terms of doping profile, spacer width, gate dielectric material, and spacer dielectric material.     

Successful simulation of solution gas drive in heavy oils using conventional modeling

Detailed investigations into the production behavior of heavy oil reservoirs under foamy solution gas drive have been conducted extensively in the past. Historically, two approaches have been used to explain and model the solution gas drive in heavy oil reservoirs. The first approach is the base of foamy oil models in which solution gas drive is governed by parameters such as compressibility, viscosity, nonequilibrium phenomena, and the supersaturation. In the second approach, conventional modeling, which we show to be suitable for the history matching and prediction of the production data and macroscopic modeling of a series of depletion experiments (using a live combination of heavy oil and methane gas in a three-dimensional rectangular laboratory model), the foamy oil flow mechanism, dispersed flow of gas and the supersaturation are nonexistent. The conventional modeling uses parameters such as critical gas saturation, very low gas relative permeability, and the assumption of no supersaturation in the reservoir.