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.

&nbsp;

&nbsp;

VIT University

Department of Physics

Diphenylacetylene (DPAC) is a promising organic scintillator material for fast neutron detection. Solubility measurement was carried with two different solvents such as toluene and methanol. Stilbene mixed diphenylacetylene (DPACS) was successfully harvested from toluene with the dimensions of 42 × 12 × 8 mm3. X-ray diffraction confirms the monoclinic crystal structure with the obtained lattice parameters. The vibrational characteristic functional group was identified by FTIR studies. UV–Vis spectral analysis of the grown DPACS crystal reveals good optical transparency in visible and near IR region. The thermal behaviour and melting point of the sample was analysed by TGA-DSC. Chemical etching analysis was carried out on the crystal surface at an ambient temperature to see the dislocations and growth pattern of the crystal. Fluorescence broad emission peak was observed and the prompt and delayed fluorescence lifetimes of the DPACS were calculated. © 2021, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.

World University root node

School of Advanced Sciences

Vellore Campus

Journal of Materials Science: Materials in Electronics

Fluorescence emission, life time, thermal properties of trans-stilbene mixed diphenylacetylene scintillator crystal

Novel tertiary nanocomposite films comprising of poly (vinyl alcohol) (PVA), poly (4-styrenesulfonic acid) (PSSA) and titanium dioxide (TiO2) nanoparticles (NPS) were prepared using simple solvent casting method. The structural, thermal, morphological, thermo-mechanical and electromagnetic interference (EMI) shielding properties of PVA/PSSA/TiO2 nanocomposite films were investigated. The EMI shielding effectiveness (SE) of PVA/PSSA/TiO2 nanocomposite films in the X and Ku band was found to be 12 dB and 13 dB respectively at 25 wt% TiO2 NPs loading. These results demonstrate the possible applications of PVA/PSSA/TiO2 nanocomposite films as low cost, lightweight and flexible material for EMI shielding. © 2019, © 2019 Taylor &amp; Francis.

VIT Unitversity

Polymer-Plastics Technology and Materials

Dynamic mechanical analysis and broadband electromagnetic interference shielding characteristics of poly (vinyl alcohol)-poly (4-styrenesulfonic acid)-titanium dioxide nanoparticles based tertiary nanocomposites

In the present study, a green synthesis approach has been employed to prepare cadmium sulphide nanoparticles (CdS NPs). The prepared CdS NPs were used as nanofiller (0-3 wt%) to produce polyvinyl alcohol (PVA)/CdS nanocomposite films via solution casting technique. The Fourier transform infrared spectroscopy, X-ray diffraction, thermogravimetric analysis, scanning electron microscopy, and atomic force microscopy were employed to investigate various properties of PVA/CdS nanocomposite films. An enhancement in the structural, thermal, and morphological properties of the PVA/CdS nanocomposite films was noticed confirming the successful incorporation of CdS NPs in the PVA matrix and good interaction between the polymer and the nanofiller. Further, an impedance analyzer was employed to evaluate dielectric properties of the PVA/CdS nanocomposite films at various frequencies (50 Hz-1 MHz) and temperatures (40°C-140°C). The dielectric constant (ε) and dielectric loss (tanδ) values of PVA/CdS nanocomposite films loaded with 3 wt% of CdS NPs were found to be 423.71 and 4.18, respectively, at 50 Hz and at 140°C. An improvement in the dielectric properties evidenced the homogeneous distribution of CdS NPs within the PVA matrix making the nanocomposite films useful for electrical charge storage devices. © 2020 Society of Plastics Engineers

Polymer Composites

Green chemistry mediated synthesis of cadmium sulphide/polyvinyl alcohol nanocomposites: Assessment of microstructural, thermal, and dielectric properties

Strontium (Sr) substituted zinc ferrite (ZnFe2-xSrxO4) nanoparticles at x = 0.2, 0.4, 0.6 &amp; 0.8 were prepared using simple and low cost co-precipitation method using polyethylene glycol as surfactant. From the X-ray diffraction (XRD) results, it was found that the prepared ZnFe2-xSrxO4 nanoparticles were crystallized in cubic spinel structure and the crystallite size decreases from 20 nm to 12 nm for x = 0.2 to x = 0.8. From optical studies it was found that the band gap of the ZnFe2-xSrxO4 nanoparticles increased (1.95 eV–2.13 eV) with increase of strontium concentration. The dielectric measurements show that the nanoparticles exhibited high dielectric constant at room temperature (30 °C) and low frequency (102 Hz) and it increased with strontium concentration. The magnetic properties of the zinc ferrite nanoparticles show ferromagnetic nature and the strength of magnetization increased with strontium concentration. © 2020 Elsevier B.V.

Physica B: Condensed Matter

Structural, dielectric and magnetic properties of ZnFe2-xSrxO4 nanoparticles prepared by co-precipitation method

Dielectric relaxation properties of aqueous solutions of Malonamide (MAL) with different compositions are studied using Time Domain Reflectometry (TDR). The Molecular interactions and dipole properties are described using excess dielectric parameters and effective Kirkwood factors. Thermal properties show dissociation effects with an increase in solute concentration within the mixture. The positive values of molar enthalpy suggest heat energy is being absorbed during the dipole reorientation process. Luzar model has been used to determine theoretical values of static dielectric constant and adequately it determines Kirkwood correlation values. The theoretical vibrational spectroscopy of MAL-Water complexes was performed which shows the carbonyl group (C=[dbnd]O) of MAL acts as a hydrogen bonding site. The Mulliken charge plot of MAL in its gaseous and solution phase shows that the compound is more electronegative in its solution phase. The hydrogen-bonding interactions between the solute-solvent molecules are verified by FTIR spectroscopy. The experimental and theoretical IR frequencies were found to be consistent. © 2020 Elsevier B.V.

Journal of Molecular Liquids

Hydrogen bond dynamics in aqueous Malonamide system: An experimental and theoretical approach

The synthesis of a nano-dimensional cluster of PrFeO3 orthoferrite with interesting tunable characteristics is the principal objective of this work. We document a very simple and improved co-precipitation method to synthesize nanoparticles of the desired dimension of rare earth substituted orthoferrite PrFeO3. The structural distortion is analyzed with Powder X-ray diffraction, which explores a distorted perovskite crystallized ferrite with space group Pbnm (62). The electrical behaviour of the prepared sample is investigated in a frequency range of 50 Hz to 5 MHz at different temperatures. A shift in the dielectric behaviour is noticed at about 250 °C. The morphological structure of the sample explored with High Resolution Transmission Electron Microscope (HRTEM), portraits a nano clustered structure. The magnetic properties of PrFeO3 are observed with Vibrating Sample Magnetometer (VSM) at 20 K and 300 K. A Very interesting change in magnetization is noticed at about 172 K–200 K. The effect of temperature on magnetic properties of PrFeO3 is reportedly due to the spin reorientation transition from Γ2 →Γ4 at TSR ≈ 172 K–200 K temperature range. The electronic band structure of nanoscale PrFeO3 with spin up and spin down states of antiferromagnetic nature is reported. PrFeO3 also exhibit multiferroic properties. © 2019 Elsevier B.V.

Mathematics

Chennai Campus

Journal of Alloys and Compounds

Spin reorientation transition in nanoscale multiferroic PrFeO3 and its band structure calculation

Microwave sintered magnesium ferrite (MF) nanoparticles are synthesised by hydrothermal technique. X-ray diffraction revealed pure spinel phase but low crystallinity. Synthesised MF is observed to be in nanoscale under scanning electron and transmission electron microscopes. MF is characterised further by Fourier transform infrared and UV-visible spectrometers for vibrational bands and optical band gap information. Electric and magnetic characterizations revealed low conductivity, dielectric loss, magnetic loss and fairly good initial permeability. High coercivity and M-H loop area of MF indicate the hard magnetic nature. © 2019, Springer Science+Business Media, LLC, part of Springer Nature.

Department of Computational Intelligence

School of Computer Science and Engineering

Journal of Superconductivity and Novel Magnetism

Effect of Microwave Heat Treatment on Hydrothermal Synthesis of Nano-MgFe2O4

Multi-tenancy is an essential feature in cloud computing and is a major component to achieve scalability and energy-efficient solution to gain high level of economic benefits. As the cloud, computing is gaining more audiences and high user base, the problem of scheduling the computational workflow for multi-tenant cloud scheduling is becoming a difficult task to achieve. In this study, we present a learning-based scheduler for catering heterogeneous software and hardware resources in the context of multi-tenant cloud computing. The experimentation has been carried out with the help of green cloud simulator and the results are compared with the state of the art techniques like minimum completion time, first come first serve and backfilling. The experimental results exhibit that the presented algorithm provides an effective means of utilizing cloud resources in addition with drastic reduction in cost of operation.

Computer Science

The International Journal of Electrical Engineering & Education

Reinforcement learning-based controller for adaptive workflow scheduling in multi-tenant cloud computing

The aqueous solutions of Nicotinamide (NIA, vitamin B3), with various concentrations, are investigated at different temperatures applying Time Domain Reflectometry (TDR) technique. The complex dielectric spectra of NIA-water solutions are fitted with the Debye relaxation model and the dielectric relaxation parameters like static dielectric constant, relaxation time have been determined by non-linear least square fit method. The Excess dielectric parameters and Kirkwood correlation factors show a significant change in dipole orientation also indicates the formation of cluster structures within the mixture. The thermodynamic parameters, Arrhenius characteristics and viscosity effects are reported. The FTIR spectroscopy confirms the heteromolecular hydrogen bond formation, through functional group interaction in the mixture systems; moreover, the NIA-Water clusters are optimized and the hydrogen bond interactions are discussed. The resulting theoretical vibrational frequency of C = O and C-N bond of NIA is found to be consistent with experimental frequencies. © 2020 Informa UK Limited, trading as Taylor &amp; Francis Group.

Physics and Chemistry of Liquids

Microwave dielectric relaxation dynamics of aqueous Nicotinamide (vitamin B3): a dielectric and thermodynamic approach using time domain technique

There is no ideal detector-phantom combination to perform patient specific quality assurance (PSQA) for Total Marrow (TMI) and Lymphoid (TMLI) Irradiation plan. In this study, 3D dose reconstruction using mega voltage computed tomography detectors measured Leaf Open Time Sinogram (LOTS) was investigated for PSQA of TMI/TMLI patients in helical tomotherapy. The feasibility of this method was first validated for ten non-TMI/TMLI patients, by comparing reconstructed dose with (a) ion-chamber (IC) and helical detector array (ArcCheck) measurement and (b) planned dose distribution using 3Dγ analysis for 3%@3mm and dose to 98% (D98%) and 2% (D2%) of PTVs. Same comparison was extended for ten treatment plans from five TMI/TMLI patients. In all non-TMI/TMLI patients, reconstructed absolute dose was within ± 1.80% of planned and IC measurement. The planned dose distribution agreed with reconstructed and ArcCheck measured dose with mean (SD) 3Dγ of 98.70% (1.57%) and 2Dγ of 99.48% (0.81%). The deviation in D98% and D2% were within 1.71% and 4.10% respectively. In all 25 measurement locations from TMI/TMLI patients, planned and IC measured absolute dose agreed within ± 1.20%. Although sectorial fluence verification using ArcCHECK measurement for PTVs chest from the five upper body TMI/TMLI plans showed mean ± SD 2Dγ of 97.82% ± 1.27%, the reconstruction method resulted poor mean (SD) 3Dγ of 92.00% (± 5.83%), 64.80% (± 28.28%), 69.20% (± 30.46%), 60.80% (± 19.37%) and 73.2% (± 20.36%) for PTVs brain, chest, torso, limb and upper body respectively. The corresponding deviation in median D98% and D2% of all PTVs were &lt; 3.80% and 9.50%. Re-optimization of all upper body TMI/TMLI plans with new pitch and modulation factor of 0.3 and 3 leads significant improvement with 3Dγ of 100% for all PTVs and median D98% and D2% &lt; 1.6%. LOTS based PSQA for TMI/TMLI is accurate, robust and efficient. A field width, pitch and modulation factor of 5 cm, 0.3 and 3 for upper body TMI/TMLI plan is suggested for better dosimetric outcome and PSQA results. © 2020, The Author(s).