The Water-Gas Shift Reaction Over Au-Based, Bimetallic Catalysts. The Au-M (M=Ag, Bi, Co, Cu, Mn, Ni, Pb, Ru, Sn, Tl) on Iron(III) Oxide System

The bimetallic Au-M/Fe₂O₃ catalysts were prepared by deposition coprecipitation method with Au/M atomic ratio of 1. All the catalysts were measured for WGS reaction and characterized by TPR/TPO studies. Ruthenium- and nickel-modified catalysts showed higher WGS activities compared to the other systems including unmodified Au/Fe₂O₃ at low temperature (100 °C). At higher temperature (240 °C), ruthenium-, nickel-, bismuth-, lead-, copper-, silver-, thallium- and tin-modified catalysts were more active than unmodified Au/Fe₂O₃. Manganese- and cobalt-modified catalysts were less active than unmodified Au/Fe₂O₃. TPR analyses indicated a shift in reduction temperature in the bimetallic catalysts, suggesting a degree of interaction between gold and the second metal.     

Electrical transport properties of Nd0.67−x Eu x Sr0.33MnO3 (0 ≤ x ≤ 0.67) manganites

A systematic investigation of electrical transport properties viz., electrical conductivity and thermopower of Eu-doped Neodymium-based colossal magnetoresistive manganites with compositional formula, Nd_0.67−x Eu _x Sr_0.33MnO₃ (x = 0–0.67) has been undertaken. These materials were prepared by citrate gel route and characterized by X-ray diffraction, scanning electron microscopy, AC susceptibility, and electrical resistivity measurements. With a view to understand the complex conduction mechanism of these materials, electrical resistivity and thermoelectric power (TEP) data have been analyzed using various theoretical models. It has been concluded that the ferromagnetic metallic part of the conduction mechanism is explained by grain/domain boundary, electron–electron, and magnon scattering mechanisms, while that of high temperature paramagnetic insulating region might be due to small polaron hopping mechanism. The sign change of charge carriers observed in TEP measurements is attributed to the oxygen deficiency of the samples.     

Formability Limit in Containerless (Open Die) Extrusion of Commercial Purity Titanium Rods and Tubes

Containerless extrusion requires far less forces compared to conventional direct extrusion of rods and tubes due to the elimination of container wall-billet friction. But the strains that can be imparted are less in the former due to the unsupported billet which gets upset first if the axial stress exceeds yield stress of the billet material. If this stress is equal to yield stress, it corresponds to the limit of the process of pure containerless extrusion. It is found that this limit strain as predicted by theory is far less compared to what is observed experimentally. This discrepancy is explained on the basis of heating that takes place in the deformation zone due to ideal, frictional, and shear work done in carrying out the extrusion process.     

Characterization of robust performance using response surfaces

Design of robust controllers in the face of process model uncertainty is an important problem. The new design methodologies in the frequency domain have sought to address some of the issues involved in robust control. Never-theless, the characterization and measurement of uncertainty remains a somewhat difficult and abstract task. In order to easily compare and characterize robust performance of alternate stable control structures, it would be useful to have an intuitive, easily applicable measure of robust performance. In this paper we propose a new time domain based measure of robust performance using geometric concepts borrowed from Response Surface Methodology. The measure is used to characterize robust performance of single-input-single-output systems. Simulations results are provided to illustrate the use and intuitive appeal of the new measure.     

Electrospun polyurethane and soy protein nanofibres for wound dressing applications

In this report, a novel wound dressing material has been woven by electrospinning technique and tested for its various properties. For the nanofibre mat, a mixture of polyurethane (PU) and soy protein isolate (SPI) was electrospun in conjugation with zinc oxide nanoparticles (ZnO Nps) and ciprofloxacin hydrochloride (CipHCl) to produce fibrous mats viz. PU/SPI/ZnO and PU/SPI/CipHCl. An optimum ratio (1 : 1) of PU/SPI was used as suitable polymeric ratio in order to produce homogenous nanofibres without beads having an average diameter in the range of 300–350 nm. The electrospun nanofibre‐based mats were characterised using X‐ray diffraction, Fourier transform infrared spectroscopy, ultraviolet‐visible spectroscopy, thermogravimetric analysis and scanning electron microscope. The mechanical properties of the nanofibrous mats were tested using universal testing machine. The wettability analysis was done using the contact angle measurement based on the sessile drop test. This study revealed that the electrospun PU/SPI‐based nanofibres are non‐sensitizing, non‐allergic and non‐toxic and that it can be used as a peculiar wound healing material.Inspec keywords: polymer fibres, nanofibres, nanomedicine, biomedical materials, wounds, electrospinning, zinc compounds, II‐VI semiconductors, wide band gap semiconductors, nanoparticles, nanofabrication, X‐ray diffraction, Fourier transform spectra, infrared spectra, ultraviolet spectra, visible spectra, thermal analysis, scanning electron microscopy, wetting, contact angle, toxicologyOther keywords: electrospun polyurethane nanofibres, soy protein nanofibres, wound dressing applications, electrospinning, nanofibre mat, soy protein isolate, zinc oxide nanoparticles, ciprofloxacin hydrochloride, X‐ray diffraction, Fourier transform infrared spectroscopy, ultraviolet‐visible spectroscopy, thermogravimetric analysis, scanning electron microscope, mechanical properties, universal testing machine, wettability, contact angle measurement, sessile drop test, nonsensitizing nanofibres, nonallergic nanofibres, nontoxic nanofibres, wound healing material, wavelength 300 nm to 350 nm, ZnO     

Intelligent explanation generation system for phishing webpages by employing an inference system

Phishing is a fraudulent scheme to steal a user’s personal and confidential information by masking as a trustworthy entity in the electronic commerce. Phishers lure online users to visit their fake webpages and capture the user’s sensitive financial information. The current anti-phishing technique focuses on determining the legitimacy of the webpages that the user visits, and it alerts users with a phishing label when a webpage is found to have suspicious activity. Most of the times, however, these warnings are ignored by the users as there is no significant information present in the alerts except for the phishing label. The method proposed in this paper addresses the aforementioned lacunae by generating a coherent and complete explanation in the natural language text for the anti-phishing system’s decision. The explanation includes the phishing label along with information to establish why such a decision has been taken. This would, in turn, contribute to the user’s enhanced understanding of the threat and also strengthens the user’s trust in the system. It is quite evident from the pilot evaluation, which involved 50 users, that the proposed methodology significantly improves the user’s understanding of the phishing label and strengthens their trust in the system.     

Artificial neural network modeling to evaluate and predict the deformation behavior of stainless steel type AISI 304L during hot torsion

The deformation behavior of type 304L stainless steel during hot torsion is investigated using artificial neural network (ANN). Torsion tests in the temperature range of 600–1200 °C and in the (maximum surface) strain rate range of 0.1–100 s^?1 were carried out. These experiments provided the required data for training the neural network and for subsequent testing. The input parameters of the model are strain, log strain rate and temperature while torsional flow stress is the output. A three layer feed-forward network was trained with standard back propagation (BP) and Resilient propagation (Rprop) algorithm. The paper makes a robust comparison of the performances of the above two algorithms. The network trained with Rprop algorithm is found to perform better and also needs less number of iterations for convergence. The developed ANN model employing this algorithm could efficiently track the work hardening, dynamic softening and flow localization regions of the deforming material. Sensitivity analysis showed that temperature and strain rate are the most significant parameters while strain affects the flow stress only moderately. The ANN model, described in this paper, is an efficient quantitative tool to evaluate and predict the deformation behavior of type 304L stainless steel during hot torsion.     

Assessing the quality of lubricants using a reduction capacity test

Lubricants play a vital role in the success of metal working operations. Economy can be improved by using the optimum lubricant to give the maximum possible single stage reduction without an appreciable increase in deformation force. The quality of different lubricants for a given application must be assessed, using a test method which stimulates the operating conditions. Most metal forming operations employ compressive stresses for deformation. In this article the authors describe a tool design to evaluate lubricants under such conditions. Using these tools, tests were conducted on aluminium sheet in a 100t hydraulic press. The experimental results are presented.     

Flame‐assisted flash sintering: A noncontact method to flash sinter coatings on conductive substrates

We present a novel and effective method for sintering ceramic coatings onto metallic substrates. This new technique, called Flame‐assisted flash sintering (FAFS), utilizes a flame as both a heating source and a conformal, current‐carrying top electrode to facilitate flash sintering. Using this method, Yttria‐stabilized Zirconia (8 mol% Y, 8YSZ) coatings are sintered onto stainless steel substrates to controlled degrees of porosity in rapid fashion. Flame‐assisted flash sintering utilizes a dynamic soft electrode for flash sintering and has commercial potential to sinter ceramic coatings on complex‐shaped substrates for a variety of applications including tribological or thermal protection coatings.