Process optimization of dye-sensitized solar cells using $$\hbox {TiO}_{2}$$–graphene nanocomposites

\(\hbox {TiO}_{2}\)–graphene (TGR) nanocomposites with varying concentrations of graphene from 0 to 1 wt% were prepared by direct mix method. X-ray diffraction (XRD) spectra confirmed the incorporation of graphene in photoanode material, which was further supported by field emission scanning electron microscopy (FESEM) and energy dispersive X-ray (EDX). The UV–visible spectrum of these nanocomposites shifted towards higher wavelength region as compared to pure \(\hbox {TiO}_{2}\) that indicated a reduced band gap and hence, enhanced absorption bandwidth. Significant reduction in electron–hole recombination was confirmed from photoluminescence spectroscopy. These TGR nanocomposite films after tethering with black dye were employed as photoanodes in dye-sensitized solar cells (DSSCs). The efficiency of solar cells at varying concentrations of graphene (in photoandes) was also investigated. TGR 0.25 wt% nanocomposite showed the highest photocurrent density (\(J_{\mathrm{SC}}\)) of \(18.4\,\hbox {mA}\,\hbox {cm}^{-2}\) and efficiency (\(\eta \)) of 4.69%.     

A technique to match highly similar 3D objects with an application to biomedical security

Multimedia Tools and Applications - Biometric technologies such as the face, fingerprint, and iris recognition have important utility in biomedical and healthcare applications. The use of...     

Room layout estimation in indoor environment: a review

Multimedia Tools and Applications - Scene understanding from the single image of an indoor scene is identified as a challenging task. This involves interpreting the assessment of multiple scene...     

Passive image forensics using universal techniques: a review

Digital tamper detection is a substantial research area of image analysis that identifies the manipulation in the image. This domain has matured with time and incredible accuracy in the last five years using machine learning and deep learning-based approaches. Now, it is time for the evolution of fusion and reinforcement-based learning techniques. Nevertheless, before commencing any experimentation, a researcher needs a comprehensive state of the art in that domain. Various directions, their outcome, and analysis form the basis for successful experiments and ensure better results. Universal image forensics approaches are a significant subset of image forensic techniques and must be explored thoroughly before experimentation. This motivated authors to write a review of these approaches. In contrast to the existing recent surveys that aim at image splicing or copy-move detection, our study aims to explore the universal type-independent techniques required to highlight image tampering. Several universal approaches based on resampling, compression, and inconsistency-based detection are compared and evaluated in the presented work. This review communicates the approach used for review, analysed literature, and lastly, the conclusive remarks. Various resources beneficial for the research community, i.e. journals and datasets, are explored and enumerated. Lastly, a futuristic reinforcement learning-based model is proposed.

     

Direct Writing of Polycaprolactone Polymer for Potential Biomedical Engineering Applications

Topography, which in this paper includes the surface features and the features themselves, is a crucial physical cue for cells, influencing cell adhesion, proliferation and differentiation and should be considered when designing biomedical architectures. A new technique using electrohydrodynamic (EH) print‐patterning is described that generates ordered topographies using proven biomaterials and composites. Coupling this method with solvent evaporation techniques, desirable scaffold properties can be achieved. To demonstrate this, various solutions of polycaprolactone (PCL) and its composites (using nano‐hydroxyapatite (nHA)) have been selected to generate topographic and 3D structures. Electrically driven patterning of the polymer is achievable and can be used to deposit fine (<5 µm) ordered structures, according to a predetermined architecture via a computer with control on porosity and bioactivity. The results from this study indicate that this method to deposit bioactive structures with morphology control will offer great potential in biomedical engineering.     

High temperature thermal expansion characteristics of Ni3Al alloys

The thermal expansion of Ni₃Al alloys with and without ternary additions have been investigated with the aid of a dilatometer. The Ni₃Al alloys were studied over the temperature range 25–1000 °C. The coefficient of thermal expansion of all the aluminides studied in this investigation varies linearly with the temperature. The coefficient of thermal expansion of Ni₃Al is found to show an increase with the decrease in Al content from stoichiometric composition. B and Zr additions decrease the value of Ni₃Al alloys at room temperature while Hf and Ti additions do not alter it significantly.     

Behaviour of cold formed lipped angles in transmission line towers

The importance and use of equivalent radius of gyration method is discussed and necessary expressions are derived in this paper. The limiting values of slenderness ratio for the equivalent radius of gyration with the least radius of gyration are discussed to establish the buckling behaviour of lipped angles. Finite Element Analysis on the buckling behaviour of the mathematical models of individual lipped angle members and a full scale X-panel was carried out to compare the values predicted by equivalent radius of gyration. A series of compression tests were carried out on lipped angle sections and their behaviour is studied in the elastic and in the inelastic ranges of loading. These tests were broadly classified under two categories; concentrically loaded members and eccentrically loaded members. Experimental investigations on full scale tower panels with conventional patterns of leg and diagonals were also carried out. The results of the experiments were compared with analytical predictions using torsional flexural buckling equations, Finite Element Analysis and the equivalent radius of gyration approach.     

Sustainable transport and the modernisation of urban transport in Delhi and Stockholm

This article addresses issues of the development of transport systems taking its examples from Delhi and Stockholm. The introduction of the first bus rapid transport corridor in Delhi and the congestion tax in Stockholm is presented and discussed in terms of modernisation and sustainable transport. This paper explores the perceptions of politicians and examines some transport plans in the search for the driving forces for transport policies. The continuing presence of a high proportion of non-motorised modes of transport and use of public transport in Delhi over the past 50 years gives it a greater political opportunity for creating a more inclusive city than Stockholm. Whereas, in Stockholm, awareness of the influence of emissions on climate change makes the inhabitants more inclined to accept fees for the use of city streets where sustainable transport and modernisation of transport systems are seen as key activities, but are perceived and operationalised differently in Delhi and Stockholm. Despite all the differences, some similarities in the development of their urban transport projects have been found. This paper inquires into the planning and operationalisation of transport modernisation and the politics of sustainable transport.     

Using iron precipitants to remove arsenic from water: Is it safe?

Arsenic-associated health complications are reported worldwide. Arsenic is a documented toxic element in drinking water. Removing arsenic from drinking water is widely dependent on iron-based techniques. Although inorganic arsenic has long been known to be toxic to humans, little is known about the toxic effect of the interaction between arsenic and iron. We investigated the effect of arsenic plus iron on the liver of rats. We gave rats sodium arsenite, iron, or sodium arsenite plus iron. Neither the arsenic-alone nor the iron-alone treatments altered their serum aspartate or alanine transaminase levels. However, a combination of non-toxic doses of arsenite and iron synergistically increased serum aspartate and alanine transaminase levels and lipid peroxidation in liver tissue. Therefore, we hypothesize that arsenic plus iron synergistically induces hepatic damage mediated through oxidative stress in rats. Our study indicates an important public health issue: using iron precipitants to remove arsenic from water may cause oxidative hepatic damage in humans.     

Plastic deformation analysis in machining of Inconel-718 nickel-base superalloy using both experimental and numerical methods

Surface region plastic deformation of Inconel-718 nickel-base superalloy workpieces was evaluated when machined under orthogonal cutting conditions at various cutting speeds. Plastic deformation analysis was accomplished by determining the residual stress and plastic strain distributions in the surface region. The residual stresses were tensile and maximum near the surface and decreased in magnitude with an increase in depth beneath the machined surface. Similarly, the plastic strains were maximum near the surface and decreased with an increase in depth beneath the machined surface. In addition, a finite element simulation of orthogonal machining was carried out for predicting the residual stress and plastic strain distribution. In general, the trend of the curves predicted by the finite element model was similar to those found experimentally.