Nanostructured virus crystals for X-ray optics

Certain virus structures can be assembled in the form of a periodic lattice with nanometer-range ordering. Cowpea mosaic virus is crystallized in body-centered-cubic geometry and used as a template for fabrication of metallized thin films with three-dimensional morphology. Calculations predict that these crystals exhibit a normal-incidence reflectivity of 7% for wavelengths around 35 nm, which can be utilized for soft X-ray optical systems.     

Updating a 1950s-generation aluminum smelter

Hindalco’s aluminum electrolysis cells were initially installed in 1962, and the technology was based on 1950s-generation pots. Although Hindalco expanded its aluminums melting capacity from 20,000 tonnes per year to 175,000 tonnes per year, the basic design of the pots remained unchanged. In view of energy price increases, and to keep pace with the latest developments in aluminum smelting technology, Hindalco undertook efforts to modernize its facilities. In spite of numerous constraints, the Hindalco smelter has been able to achieve performance nearly equivalent to that of 1980s-generation pots by retrofitting new technologies. This has resulted in considerable savings in electrical energy consumption and raw materials usage.     

Localized swelling of Fe-Cr-Ni alloy rollers in high-temperature applications

Localized swelling has been observed in 24Cr-24Ni-Nb steel transportation rollers used in the normalizing furnace of a plate mill after prolonged service at high temperature. Due to high localized thermal and mechanical stresses, the chromia layer formed on the roller surface ruptures, exposing the roller substrate to furnace oxygen. Oxidation of second-phase carbides results in the formation of carbon monoxide at very high partial pressure. This leads to formation of voids, leading in turn to localized swelling of the roller material.     

Application of AHP for Ranking of Total Productive Maintenance Pillars

Total Productive Maintenance—TPM is widely being used in industries for manufacturing excellence. TPM is based on its eight pillars. Successful Implementation of TPM from its kick-off to final stage depends on in-depth knowledge of these pillars. The purpose of the paper is to rank eight pillars of TPM according to their importance with respect to four parameters: Productivity, Cost, Quality and Delivery in Time, by using Analytic Hierarchy Process (AHP) a multiple criteria decision-making methodology. A pairwise comparison of TPM pillars is done by use of AHP method, by considering a case of automotive industries in India. Ranking of TPM pillars is proposed to set guidelines to decide the weightage of each pillar in terms of major factors to improve Overall Equipment Efficiency. This in terms will guide management to give proper preference and allocate fund at proper time to proper pillar. The ranking suggested suites for automotive sector and assembly lines. By varying the judgmental rating the new ranking can be obtained from the suggested guidelines on similar basis.     

Abrasive wear of cast aluminium alloy-zircon particle composites

The abrasive wear rates of particulate composites of an Al-11.8Si-4Mg alloy containing up to 0.35 volume fraction of zircon particles (average size, 100 μm) were measured on an 80 grit aloxide cloth sheet as a function of the volume fraction of zircon, the applied load and the number of passes over the abrasive paper. When the volume fraction of zircon is above a critical value of 0.09, the abrasive wear resistance (reciprocal of the wear rate) increases with the volume fraction of zircon according to the rule of mixtures. When the volume fraction is fixed, the abrasive wear resistance increases with the number of passes possibly because of blunting of the alumina particles of the abrasive cloth. No improvement in the abrasive wear resistance of composites over the matrix alloy was observed when the volume fraction of zircon was below 0.09. Scanning electron microscopy studies of the abraded surfaces of composites revealed fractured zircon particles but no evidence of filler particle pull-outs or debonding at the interface was obtained.     

Incoherent transport in NEMO5: realistic and efficient scattering on phonons

In this work, the coherent and incoherent transport simulation capabilities of the multipurpose nanodevice simulation tool NEMO5 are presented and applied on transport in tunneling field-effect transistors. The comparison with experimental resistivity data confirms the validity of NEMO5’s phonon-scattering models. Common pitfalls of numerical implementations and the applicability of common approximations of scattering self-energies are discussed. The impact of phonon-assisted tunneling on the performance of TFETs is exemplified with a concrete Si nanowire device. The communication-efficient implementation of self-energies in NEMO5 is demonstrated with a scaling comparison of self-energies solved with blocking and nonblocking MPI-communication.     

Optimal placement of piezoelectric patches over a smart structure

Control of structural vibrations has significant applications in manufacturing, infrastructure engineering, aerospace engineering and various consumer products. In last two decades, considerable attention has been focused to suppress structural vibrations using active vibration control technique. Various researchers have proposed various optimization criteria for optimal placement of piezoelectric patches over a smart structure to suppress vibrations using various optimization techniques. This paper presents a review of various optimization criteria and techniques that have been used by various researchers in the field of smart structures. Mathematical expressions of objective functions of twelve optimization criteria have been presented and their justifications have been reasoned. Step by step procedures of commonly used optimization techniques have also been presented.     

Double aperture double-gate vertical high-electron-mobility transistor

In this paper, we propose a double aperture double-gate AlGaN/GaN vertical high-electron-mobility transistor (HEMT) to improve the device characteristics, such as the current and the ON resistance (\(\hbox {\textit{R}}_{\mathrm{ON}}\)). The proposed vertical HEMT results are compared to the conventional single aperture single-gate vertical HEMT of equal dimensions, and increased drain current and lower \(\hbox {\textit{R}}_{\mathrm{ON}}\) are shown. A comprehensive simulation study has also been carried out for the proposed device, to analyse the impact of thickness and doping concentration of aperture, drift region, and current blocking layer. In addition, the effect of different materials in current blocking layer on device characteristics is also studied. The obtained results and their effect on device characteristics have been thoroughly analysed and explained accordingly.     

Experiments with fast Fourier transform, linear predictive and cepstral coefficients in dysarthric speech recognition algorithms using hidden Markov Model.

In this study, a hidden Markov Model was constructed and conditions were investigated that would provide improved performance for a dysarthric speech (isolated word) recognition system. The speaker dependant system was intended to act as an assistive/control tool. A small size vocabulary spoken by three cerebral palsy subjects was chosen. Fast Fourier transform, linear predictive, and Mel frequency cepstral coefficients extracted from data provided training input to several whole-word hidden Markov model configurations. The effect of model structure, number of states, and frame rates were also investigated. It was noted that a 10-state ergodic model using 15 msec frames was better than other configurations. Furthermore, it was found that a Mel cepstrum based model outperformed a fast Fourier transform and linear prediction based model. The system offers effective and robust application as a rehabilitation and/or control tool to assist dysarthric motor impaired individuals.     

Enhancing the prediction of type 2 diabetes mellitus using sparse balanced SVM

Multimedia Tools and Applications - The natural population-based prediction of type 2 diabetes is costly since it needs a high number of resources. Even though much research has used machine...