Vellore Institute of Technology (VIT) is a private university located in&nbsp;Tamil Nadu, India. Founded in 1984, as Vellore Engineering College, the institution offers 20 undergraduate, 34 postgraduate, four integrated and four research programs. It has campuses in Vellore, Amravati, Bhopal and Chennai.

VIT is one of the top ranked private universities in India according to NIRF, THE and QS Rankings.&nbsp;Govt. of India has recognized&nbsp;VIT, Vellore as an&nbsp;Institution of Eminence. This has allowed VIT to take independent quality initiatives and move up in world ranking.

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VIT University

Centre for Nanotechnology Research

Copper sulfide–reduced graphene oxide nanocomposites were synthesized hydrothermally from copper nitrate and thiourea as precursor materials.

VIT Unitversity

Vellore Campus

RSC Advances

A template-free facile approach for the synthesis of CuS–rGO nanocomposites towards enhanced photocatalytic reduction of organic contaminants and textile effluents

The design of a free-standing (substrate-less) metallic hole array is proposed for Terahertz frequencies. The bandpass filtering effect through free standing perforted Aluminium (Al) films is demonstrated using a square array of circular holes on Al films having thickness of ∼ 11 μm. The effect of variation of periodicity and hole diameter on the transmittance due to excitation of surface plasmons and coupling between resonant and non-resonant modes is studied. © 2015 IEEE.

World University root node

IRMMW-THz 2015 - 40th International Conference on Infrared, Millimeter, and Terahertz Waves

THz bandpass filter based on sub-wavelength holes in free-standing metal thin-films

Abstract: The luminescent lanthanide-doped nanoparticles have gathered considerable attention in many fields especially in biomedicine. In this work, the lanthanum fluoride-doped terbium nanoparticles (LaF3:Tb3+ NPs) via simple chemical precipitation method has been synthesized and functionalized with polyethylene glycol. The size and the shape of the nanoparticles are confirmed using X-ray diffraction and transmission electron microscopy. The conjugation of 5-Fluorouracil (5-FU) and thus synthesized nanoparticles (NPs) were confirmed using various spectroscopic methods such as UV–Visible spectroscopy, fluorescence steady state, and excited state spectroscopy studies. The enhancement in fluorescence emission (λ = 543 nm) of drug-conjugated nanoparticles confirms the Vander Waals force of attraction due to F–F bonding between the drug and the nanoparticles. Further, the effects of 5FU-NPs in carrier protein were investigated using bovine serum albumin as a protein model. The 5FU–LaF3:Tb3+ nanoparticles binding is illustrated with binding constant and number of binding sites. The structural change of bovine serum albumin has been studied using circular dichroism and Fourier transform infrared spectroscopy analysis. Graphical Abstract: [Figure not available: see fulltext.] © 2015, Springer Science+Business Media Dordrecht.

Journal of Nanoparticle Research

Synthesis of 5-Fluorouracil conjugated LaF3:Tb3+/PEG-COOH nanoparticles and its studies on the interaction with bovine serum albumin: spectroscopic approach

Hydrothermally synthesized MnFe2O4/rGO composite with sodium alginate binder shows a highly stable capacity of 258 mA h g−1versus Na/Na+at 0.1C rate.

Chemistry

School of Advanced Sciences

Chennai Campus

A high capacity MnFe2O4/rGO nanocomposite for Li and Na-ion battery applications

Slag is one of the main waste materials of the iron and steel manufacturing. Every year about 20a 106 tons of slag are generated in the U.S. and 43.5a 106 tons in Europe. The valorization of this by-product as heat storage material in thermal energy storage (TES) systems has numerous advantages which include the possibility to extend the working temperature range up to 1000 °C, the reduction of the system cost, and at the same time, the decrease of the quantity of waste in the iron and steel industry. In this paper, two different electric arc furnace (EAF) slags from two companies located in the Basque Country (Spain) are studied. Their thermal stability and compatibility in direct contact with the most common heat transfer fluids (HTFs) used in the concentrated solar power (CSP) plants are analyzed. The experiments have been designed in order to cover a wide range of temperature up to the maximum operation temperature of 1000 °C corresponding to the future generation of CSP plants. In particular, three different fluids have been studied: synthetic oil (Syltherm 800®) at 400 °C, molten salt (Solar Salt) at 500 °C, and air at 1000 °C. In addition, a complete characterization of the studied slags and fluids used in the experiments is presented showing the behavior of these materials after 500 hr laboratory-tests. ©2015 by ASME.

Journal of Solar Energy Engineering, Transactions of the ASME

New thermal energy storage materials from industrial wastes: Compatibility of steel slag with the most common heat transfer fluids

The behavior of a magnesium and zinc eutectic metal alloy used as thermal energy storage (TES) material is tested in a laboratory scale TES unit. The TES unit consists of two concentric tubes with the central tube surrounded by 67 kg of the metal alloy and two caps at both ends of the tube through which the heat transfer fluid (HTF) flows. Charging (melting) and discharging (solidification) processes of the eutectic metal alloy are performed using synthetic oil as the HTF. The experimental results are used to test the validity of the model via simulations performed with a computational fluid dynamics tool. The results corroborate that phase change materials with high thermal conductivity, such as eutectic metal alloys, are ideal for the evaporation process of water in direct steam generation applications due to the quasi-constant melting and solidification temperatures and to its high heat transfer capacity. © 2015 The Authors. Published by Elsevier Ltd.

Fulltext

Energy Procedia

Experiments on a Lab Scale TES Unit using Eutectic Metal Alloy as PCM

Three-dimensional (3D) highly interconnected graphitized macroporous carbon foam with uniform mesopore walls has been successfully fabricated by a simple and efficient hydrothermal approach using resorcinol and formaldehyde as carbon precursors. The commercially available cheap polyurethane (PU) foam and Pluronic F127 were used as a sacrificial polymer and mesoporous structure-directing templates, respectively. The graphitic structure of carbon foam was obtained by catalytic graphitization method using iron as catalyst. Three different carbon foams such as graphitized macro-mesoporous carbon (GMMC) foam, amorphous macro-mesoporous carbon (AMMC) foam and graphitized macroporous carbon (GMC) foam were fabricated and their physicochemical and mechanical properties were systematically measured and compared. It was found that GMMC possess well interconnected macroporous structure with uniform mesopores located in the macroporous skeletal walls of continuous framework. Besides, GMMC foam possesses a well-defined graphitic framework with high surface area (445 m2/g), high pore volume (0.35 cm3/g), uniform mesopores (3.87 nm), high open porosity (90%), low density (0.30 g/cm3) with good mechanical strength (1.25 MPa) and high electrical conductivity (11 S/cm) which makes it a promising material for many potential applications. © 2015 Elsevier Ltd. All rights reserved.

Carbon

A simple approach for fabrication of interconnected graphitized macroporous carbon foam with uniform mesopore walls by using hydrothermal method

Thermal conductivity of polymer composites containing silver nanoparticles is investigated. Nano silver particles of an average size of 70 nm is synthesized by wet chemical method. Composite with different volume percentages of silver nanoparticles is made along with SU8 a well known epo\v based negative photoresist. To predict the thermal conductivity various theoretical models were studied. Experimental determination of thermal conductivity is done by Hot Wire technique. The relationship between the concentration of the nanoparticles and thermal conductivity is investigated. Jefferson, Witzell and Sibbitt theoretical model is found to be in good agreement with the experimental results. © 2015 Scientific Publishers. All Rights Reserved.

Journal of the Indian Chemical Society

Thermal property analysis of epoxy based silver nanocomposites

Graphene manganese ferrite (MnFe 2 O 4 -G) composite was prepared by a solvothermal process. The as-prepared graphene manganese ferrite composite was tested for the adsorption of lead (Pb(II)) and cadmium (Cd(II)) ions by analytical methods under diverse experimental parameters. With respect to contact time measurements, the adsorption of Pb and Cd ions increased and reached equilibrium within 120 and 180 min at 37°C with a maximum adsorption at pH 5 and 7 respectively. The Langmuir model correlates to the experimental data showing an adsorption capacity of 100 for Pb(II) and 76.90 mg g -1 for Cd(II) ions. Thermodynamic studies revealed that the adsorption of Pb and Cd ions onto MnFe 2 O 4 -G was spontaneous, exothermic and feasible in the range of 27-47°C. Cytotoxicity behavior of graphene against bacterial cell membrane is well known. To better understand its antimicrobial mechanism, the antibacterial activity of graphene and MnFe 2 O 4 -G nanocomposite was compared. Under similar concentration and incubation conditions, nanocomposite MnFe 2 O 4 -G dispersion showed the highest antibacterial activity of 82%, as compared to graphene showing 37% cell loss. Results showed that the prepared composite possess good adsorption efficiency and thus could be considered as an excellent material for removal of toxic heavy metal ions as explained by adsorption isotherm. Hence MnFe 2 O 4 -G can be used as an adsorbent as well as an antimicrobial agent. © 2014 Elsevier B.V. All rights reserved.

Mathematics

Applied Surface Science

Solvothermal synthesis of MnFe 2 O 4 -graphene composite-Investigation of its adsorption and antimicrobial properties

This article presents a broad review of long persistence (LP) materials that are a special kind of photon energy storage and conversion materials. They are also known as long afterglow phosphors or long decay phosphors (LDP). These phosphors can be readily excited by any ordinary household lamp, sunlight and/or ambient room lights and glow continuously in the dark for hours together without involving any radioactive elements. It is the modifications that are made to crystalline host lattice that exhibit these unusual properties related to persistence due to effective doping of some transition or rare-earth ions. A slight variation in the processing parameters such as type of reducing atmosphere, stoichiometric excess of one or more constituents, the nature of fluxes, and the intentional addition of carbon or rare-earth halides can drastically shift the emission colors and persistence times of the LP phosphors in the visible spectrum. Historically, Cu-doped ZnS phosphor had been a traditional LP material with its afterglow time less than an hour. The emission color of these LP phosphors was confined between green and yellow-green region only. However, synthesis of blue and red-emitting phosphors with long persistence times had been always a challenging task. This review article covers the recent advances in the blue, green and red-emitting LP phosphors/nanophosphors, persistence mechanism involved and the basic problems associated with their luminescence efficiency and persistence times. Modifications to existing nano-synthesis protocols to formulate a nontoxic Green Chemistry Route are also presented.

Defect and Diffusion Forum (Volume 361)

<a href="https://scholar.google.com/citations?view_op=view_citation&amp;hl=en&amp;user=HViuQlEAAAAJ&amp;sortby=pubdate&amp;citation_for_view=HViuQlEAAAAJ:roLk4NBRz8UC">Persistence Mechanisms and Applications of Long Afterglow Phosphors</a>