Separation of oil/water emulsions using nano MgO anchored hybrid ultrafiltration membranes for environmental abatement

This work focuses on utilizing the dual role of sulfonated polyphenyl sulfone (SPPSU) as both an anchoring agent and an interlayer modifying agent in the preparation of nano MgO/SPPSU/PPSU membranes for oil removal from water. These asymmetric membranes were prepared using the phase inversion technique. The dispersed nano MgO was observed in the membrane matrix as seen by scanning electron microscope and energy dispersive X‐ray analysis. The reduction in contact angle value establishes the increases in hydrophilicity. An increase in SPPSU (wt %) loosens the nano MgO/SPPSU/PPSU membrane packing as exhibited by the increase of d‐spacing by X‐ray diffraction analysis. The antifouling properties were tested using humic acid, as a model foulant. Further, in castor oil/water emulsion separation, it was found that the membrane with 25 wt % anchored moiety SPPSU/nano MgO produced a greater flux recovery ratio of 94.9% (±0.3) without compromising the oil rejection of 99% (±0.4) and better oleophobic surfaces for oil. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 132, 42848.     

Computational fluid dynamics study of kaolin–water flow in a T-junction using a novel shear-thinning fluid model

A recently proposed shear-thinning fluid model that mimics the response of seemingly viscoplastic materials is evaluated in computational fluid dynamics simulations by studying the steady flow of a kaolin–water suspension in a 2D T-junction. The velocity profiles for the kaolin–water suspension are reported at the mid-length of the main channel and the root of the bifurcation (where recirculation is expected to appear). The velocity profiles of the proposed model are compared with those from conventional viscoplastic models (Bingham plastic model and the Herschel–Bulkley model) at low (=100) and high Reynolds number (=2000). The new model predicts a recirculation zone (at the inner edge of the bifurcation arm) that conventional models do not. The effect of the variation in the model parameters (α₁ and α₂) on velocity profiles at low (=100) and high Reynolds numbers (=2000) is also documented. These indicate the disappearance of the recirculation zone at low Reynolds number as α₁ (equivalently, viscosity) increases, whereas the recirculation zone persists even for higher values of α₁ at high Reynolds number. Further, at low Reynolds number, the skewing of maximum velocity towards the outer edge of the bifurcation arm disappears as α₂ increases, whereas the skewing persists even at the highest value of α₂ used at the high Reynolds number.     

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.     

Microstructural Evolution Under Low Shear Rates During Rheo Processing of LM25 Alloy

Microstructural features of LM25 alloy processed by two different routes: (1) conventional casting, and (2) shear casting based on inclined heated surface are studied. The microstructures of the primary phase for the shear-cast samples show rosette or ellipsoidal morphologies. Heat transfer of contacting melt with the inclined tube surface and shear stress exerted on the layers of the melt as result of gravitational force are crucial parameters for the microstructural evolution. Compared to those produced by conventional casting, shear-cast samples have a much improved tensile strength and ductility due to globular microstructure.     

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.