Surface adsorption of poisonous Pb(II) ions from water using chitosan functionalised magnetic nanoparticles

In this study, chitosan functionalised magnetic nano‐particles (CMNP) was synthesised and utilised as an effective adsorbent for the removal of Pb(II) ions from aqueous solution. The experimental studies reveal that adsorbent material has finer adsorption capacity for the removal of heavy metal ions. Parameters affecting the adsorption of Pb(II) ions on CMNP, such as initial Pb(II) ion concentration, contact time, solution pH, adsorbent dosage and temperature were studied. The adsorption equilibrium study showed that present adsorption system followed a Freundlich isotherm model. The experimental kinetic studies on the adsorption of Pb(II) ions exhibited that present adsorption process best obeyed with pseudo‐first order kinetics. The maximum monolayer adsorption capacity of CMNP for the removal of Pb(II) ions was found to be 498.6 mg g⁻¹. The characterisation of present adsorbent material was done by FTIR, energy disperse X‐ray analysis and vibrating sample magnetometer studies. Thermodynamic parameters such as Gibbs free energy (ΔG °), enthalpy (ΔH °) and entropy (ΔS °) have declared that the adsorption process was feasible, exothermic and spontaneous in nature. Sticking probability reported that adsorption of Pb(II) ions on CMNP was favourable at lower temperature and sticking capacity of Pb(II) ions was very high.Inspec keywords: adsorption, lead, wastewater treatment, monolayers, Fourier transform infrared spectra, X‐ray chemical analysis, magnetometers, pHOther keywords: poisonous Pb(II) ions surface adsorption, chitosan functionalised magnetic nanoparticle, CMNP, Pb(II) ions removal, aqueous solution, finer adsorption capacity, heavy metal ion removal, contact time, solution pH, adsorbent dosage, adsorption equilibrium, Freundlich isotherm model, pseudofirst order kinetics, monolayer adsorption capacity, FTIR, energy disperse X‐ray analysis, vibrating sample magnetometer study, thermodynamic parameter, sticking probability, Pb(II) ions sticking capacity, initial Pb(II) ion concentration     

Construction of active bio‐nanocomposite by inseminated metal nanoparticles onto activated carbon: probing to antimicrobial activity

The bio‐nanocomposite role in wastewater treatment is a primary concern of this research. The physical, chemical, mechanical stability and antimicrobial activity of these bio‐nanocomposites were investigated. The method is based on the biological reduction of aqueous copper sulphate pentahydrate, lead nitrate, silver nitrate, zinc sulphate heptahydrate salt using seed extract of Eucalyptus globulus as reducing agent at ambient temperature. The synthesised metal nanoparticles (MNPs) were analysed by UV‐visible spectroscopy and Fourier transform infrared spectroscopy analyses. An ex‐situ method involves constructing bio‐nanocomposite by blending MNPs with tea waste activated carbon. Cross‐linking in activated carbon takes place which was confirmed by changes in the mixture of components. The present yield of activated carbon was characterised by scanning electron microscopy and energy dispersive X‐ray measurements. A few micro or nano range, spherical shape of activated carbon was studied by SEM. The main elements found in the activated carbon by EDX are C, O, S, Ag, Cl and Cu. The efficacy of such active bio‐nanocomposite (ABN) tested against human pathogen includes both type of bacteria and fungus. The inhibitory effects of ABN are discernible from the results that reveal biologically inseminated MNPs can be used to clean up the contaminated environment.Inspec keywords: nanocomposites, activated carbon, wastewater treatment, copper compounds, nitrogen compounds, Fourier transform infrared spectra, scanning electron microscopyOther keywords: active bio‐nanocomposite, inseminated metal nanoparticles, activated carbon, antimicrobial activity, wastewater treatment, mechanical stability, biological reduction, aqueous copper sulphate pentahydrate, lead nitrate, silver nitrate, zinc sulphate heptahydrate salt, Eucalyptus globulus, synthesised metal nanoparticle, MNP, UV‐visible spectroscopy, Fourier transform infrared spectroscopy analysis, scanning electron microscopy, energy dispersive X‐ray measurement, SEM     

Synthesis of organic ligand passivated zinc selenide nanorods via wet chemical route

Zinc selenide (ZnSe) nanorods have been synthesized by simple and inexpensive wet chemical method using N-Methylaniline as a capping agent. The morphologies and structure of ZnSe nanorods have been characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD). The SEM and TEM reveal the formation of nanorods. XRD shows the cubic structure with the lattice constant of 5.633 Å. Strong “blue shift” absorption is observed from UV-visible spectrophotometry. The enhanced luminescence property is measured from photoluminescence spectrophotometry. The presence of N-Methylaniline in the ZnSe nanorods is confirmed by the Fourier transformed infrared spectrum.     

Green route synthesis of nanoporous copper oxide for efficient supercapacitor and capacitive deionization performances

We demonstrate a simple template-free green method to prepare copper oxide (CuO) nanoporous material using copper acetate as a single precursor with Piper nigrum (Indian black pepper) dried fruit extract as a reducing medium under microwave irradiation. The surface properties and morphology of the obtained CuO material were assessed using powder X-ray diffractometer, X-ray photoelectron spectrometer, field-emission scanning electron microscope with elemental mapping analysis, focused ion beam high-resolution transmission electron microscope, and N₂ adsorption-isotherm techniques. The characterization results reveal that the prepared CuO is a single monoclinic crystalline phase, and nanoporous in morphology with a specific surface area of 81.23 m² g⁻¹ and containing pore sizes between 3–8 nm. Nanoporous CuO showed excellent electrochemical energy storage performance with the specific capacitance of 238 Fg⁻¹ at 5 mVs⁻¹ when compared with commercially available CuO (75 Fg⁻¹). Also, nanoporous CuO showed efficient desalting performance in the capacitive deionization system. This eco-friendly synthesis derived nanoporous CuO can be applied as high-performance supercapacitor material for high-energy storage devices and desalination processes.     

Fully automatic brain tumor extraction and tissue segmentation from multimodal MRI brain images

Segmentation of Brain tumor from the magnetic resonance imaging (MRI) of head scans is an essential requirement for clinical diagnosis since manual segmentation is a fatigue and time‐consuming process. Recent computer‐aided diagnosis systems depend on the development of fully automatic methods to overcome these problems. In the present work, a fully automated algorithm is proposed to extract and segment tumor regions from multimodal magnetic resonance imaging (MMMRI) sequences. The algorithm has three phases: (a) tumor portion extraction, (b) tumor substructure segmentation, and (c) 3D postprocessing. First, the algorithm extracts tumor portion using a set of image processing operations from T2, fluid‐attenuated inversion recovery (FLAIR), and T1C images. Here, the proposed modified fuzzy c means clustering algorithm is used for enhancing the tumor portion extraction process. Then, the substructures of tumor such as edema, enhancing tumor, and necrotic regions are segmented from MMMRI sequences, T2, FLAIR, and T1C using region‐wise set operations in Phase II. Finally, 3D visualization of the segmented tumor and volume estimation is performed as postprocessing in Phase III. The proposed work was experimented on BraTS 2013 dataset. The quantitative analysis is performed using William's Index, Dice, sensitivity, specificity, and accuracy and is compared with 19 state‐of‐the‐art methods. The proposed method yields comparable results as 77%, 53%, and 59% of Dice for complete, core, and enhancing tumor regions, respectively.     

Runtime and language support for compiling adaptive irregular programs on distributed-memory machines

In many scientific applications, arrays containing data are indirectly indexed through indirection arrays. Such scientific applications are called irregular programs and are a distinct class of applications that require special techniques for parallelization. This paper presents a library called CHAOS, which helps users implement irregular programs on distributed-memory message-passing machines, such as the Paragon, Delta, CM-5 and SP-1. The CHAOS library provides efficient runtime primitives for distributing data and computation over processors; it supports efficient index translation mechanisms and provides users high-level mechanisms for optimizing communication. CHAOS subsumes the previous PARTI library and supports a larger class of applications. In particular, it provides efficient support for parallelization of adaptive irregular programs where indirection arrays are modified during the course of computation. To demonstrate the efficacy of CHAOS, two challenging real-life adaptive applications were parallelized using CHAOS primitives: a molecular dynamics code, CHARMM, and a particle-in-cell code, DSMC. Besides providing runtime support to users, CHAOS can also be used by compilers to automatically parallelize irregular applications. This paper demonstrates how CHAOS can be effectively used in such a framework. By embedding CHAOS primitives in the Syracuse Fortran 90D/HPF compiler, kernels taken from the CHARMM and DSMC codes have been automatically parallelized.     

Recent advancements in Dragline control systems

This paper discusses about the robust machine “Dragline”, from century old techniques employed for power transmission, control and operation to the recent trends. Dragline is mostly used in mining sector for removal of overburden as it is highly economical in comparison to the usage of shovel–dumper combination of the same, however the deployment of dragline is subjected to the geographical conditions of the mine. Dragline in general mostly comprises Drag, Hoist and Swing mechanism. For the Drag, Hoist and Swing operations earlier DC machines are used with Ward–Leonard control mechanism, but recently due to advancements in power electronic devices AC motors found their application for the same due to their less maintenance costs and also reducing the number of machines resulting in increasing the overall efficiency. Also, gear less power transmission techniques are in place. In parallel, the control techniques are also getting evolved and automation is taking place starting with Swing mechanism extending to the whole operation.     

Removal of methylene blue dye from aqueous solution by activated carbon prepared from cashew nut shell as a new low-cost adsorbent

Methylene blue dye was adsorbed on an adsorbent prepared from cashew nut shell. A batch adsorption study was carried out with variable adsorbent amount, initial dye concentration, contact time and pH. Studies showed that the pH of aqueous solutions affected dye removal as a result of removal efficiency increased with increasing solution pH. The experimental data were analyzed by the Langmuir, Freundlich, Redlich-Peterson, Koble-Corrigan, Toth, Temkin, Sips and Dubinin-Radushkevich models of adsorption using MATLAB 7.1. The experimental data yielded excellent fits within the following isotherm order: Redlich-Peterson>Toth>Sips>Koble-Corrigan>Langmuir>Temkin>Dubinin-Radushkevich>Freundlich, based on its correlation coefficient values. Three simplified kinetic models including a pseudofirst-order, pseudo-second-order and intraparticle diffusion equations were selected to follow the adsorption process. It was shown that the adsorption of methylene blue could be described by the pseudo-second-order equation. The results indicate that cashew nut shell activated carbon could be employed as a low cost alternative to commercial activated carbon in the removal of dyes from wastewater.     

Structural elucidation and iron oxidation states in situ formed β‐Ca3(PO4)2/α‐Fe2O3 composites

A detailed structural analysis on the in situ synthesized β‐Ca₃(PO₄)₂/α‐Fe₂O₃ composites is demonstrated. Compositional ratios, the influence and occupancy of iron at the β‐Ca₃(PO₄)₂ lattice, oxidation state of iron in the composites are derived from analytical techniques involving XRD, FT‐IR, Raman, refinement of the powder X‐ray diffraction and X‐ray photoelectron spectroscopy. Iron exists in the Fe³⁺ state throughout the investigated systems and favors its occupancy at the Ca²⁺(5) site of β‐Ca₃(PO₄)₂ until critical limit, and thereafter crystallizes as α‐Fe₂O₃ at ambient conditions. Fe³⁺ occupancy at the β‐Ca₃(PO₄)₂ lattice yields a Ca₉Fe(PO₄)₇ structure that is isostructural with its counterpart. A strong rise in the soft ferromagnetic behavior of β‐Ca₃(PO₄)₂/α‐Fe₂O₃ composites is obvious that depends on the content of α‐Fe₂O₃ in the composites. Overall, the diverse level of iron inclusions at the calcium phosphate system with a Ca/P ratio of 1.5 yields a structurally stable β‐Ca₃(PO₄)₂/α‐Fe₂O₃ composites with assorted compositional ratios.