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

Department of Physics

Purpose: The main purpose of this study is to demonstrate the clinical implementation of a comprehensive pencil beam scanning (PBS) daily quality assurance (QA) program involving a number of novel QA devices including the Sphinx/Lynx/parallel-plate (PPC05) ion chamber and HexaCheck/multiple imaging modality isocentricity (MIMI) imaging phantoms. Additionally, the study highlights the importance of testing the connectivity among oncology information system (OIS), beam delivery/imaging systems, and patient position system at a proton center with multi-vendor equipment and software. Methods: For dosimetry, a daily QA plan with spot map of four different energies (106, 145, 172, and 221&nbsp;MeV) is delivered on the delivery system through the OIS. The delivery assesses the dose output, field homogeneity, beam coincidence, beam energy, width, distal-fall-off (DFO), and spot characteristics — for example, position, size, and skewness. As a part of mechanical and imaging QA, a treatment plan with the MIMI phantom serving as the patient is transferred from OIS to imaging system. The HexaCheck/MIMI phantoms are used to assess daily laser accuracy, imaging isocenter accuracy, image registration accuracy, and six-dimensional (6D) positional correction accuracy for the kV imaging system and robotic couch. Results: The daily QA results presented herein are based on 202 daily sets of measurements over a period of 10&nbsp;months. Total time to perform daily QA tasks at our center is under 30&nbsp;min. The relative difference (Δ rel ) of daily measurements with respect to baseline was within&nbsp;±&nbsp;1% for field homogeneity, ±0.5&nbsp;mm for range, width and DFO, ±1&nbsp;mm for spots positions, ±10% for in-air spot sigma, ±0.5 spot skewness, and ±1&nbsp;mm for beam coincidence (except 1 case: Δ rel &nbsp;=&nbsp;1.3&nbsp;mm). The average Δ rel in dose output was −0.2% (range: −1.1% to 1.5%). For 6D IGRT QA, the average absolute difference (Δ abs ) was ≤0.6&nbsp;±&nbsp;0.4&nbsp;mm for translational and ≤0.5° for rotational shifts. Conclusion: The use of novel QA devices such as the Sphinx in conjunction with the Lynx, PPC05 ion chamber, HexaCheck/MIMI phantoms, and myQA software was shown to provide a comprehensive and efficient method for performing daily QA of a number of system parameters for a modern proton PBS-dedicated treatment delivery unit.

VIT Unitversity

World University root node

School of Advanced Sciences

Vellore Campus

Fulltext

Journal of Applied Clinical Medical Physics

Development and long‐term stability of a comprehensive daily QA program for a modern pencil beam scanning ( PBS ) proton therapy delivery system

Nanocrystalline FeMnO 3 was synthesized by sol-gel method using succinic acid as a chelating agent. The structural and morphological characterizations of the synthesized material were carried out by using XRD, FT-IR, and SEM with EDX. The hysteresis loop at room temperature shows the antiferromagnetic behavior of the material. The variation in the frequency and temperature dependent dielectric constant illustrated the Maxwell-Wagner relaxation in the sample. Nyquist plot illustrated the grains resistance at higher frequency whereas at lower frequency it is dominated by the grain boundary resistance. The electrical modulus also confirms the relaxation process. The activation energy calculation of impedance and modulus shows the existence of oxygen vacancy. XPS analysis confirmed the existence of oxygen vacancy and different oxidation states of Fe 3+ /Fe 2+ and Mn 3+ /Mn 4+ in the material. Conductivity studies of the material were analyzed and fitted by using Jonscher Power law. © 2018, Springer-Verlag GmbH Germany, part of Springer Nature.

Ionics

Investigation on structural and electrical properties of FeMnO3 synthesized by sol-gel method

Known as a hard magnetic material, cobalt ferrite belongs to one of the most attractive classes of materials owing to its diverse technical applicability such as in catalysis, sensors, batteries. In this study, we synthesized Li- and Y-substituted cobalt ferrite nanoparticles using a sol–gel combustion method. Their mean crystallite sizes with spinel structures were calculated as 15–19 and 2–5 nm and their lattice constant values were 7.8 ± 0.02 and 8.5 ± 0.3 Å, respectively. The results also revealed that the band gap energy values of the prepared Li- and Y-doped cobalt ferrites decreased after doping compared with that of pure cobalt ferrite, and thus they appear to be promising for energy generation and storage applications. © 2018, Indian Association for the Cultivation of Science.

Indian Journal of Physics

The effects of lithium and yttrium substitution on the optical and structural properties of cobalt ferrites

Surfaces and Interfaces

Laser shock peening modified surface texturing, microstructure and mechanical properties of graphene dispersion strengthened aluminium nanocomposites

Department of Software Systems

School of Computer Science and Engineering

2019 International Conference on Vision Towards Emerging Trends in Communication and Networking (ViTECoN)

Crop Shop – An application to maximize profit for farmers

Iron (Fe)-doped indium tin oxide thin films (In 0.95 − x Fe x Sn 0.05 ) 2 O 3 at x = 0.00, 0.05, 0.10, and 0.15 were deposited onto glass substrates using an electron beam evaporation technique. The coated thin films were characterized by X-ray diffractometer (XRD), UV-VIS-NIR spectrophotometer, photoluminescence spectrophotometer, scanning electron microscope, and vibrating sample magnetometer to study their structural, optical, morphological, and magnetic properties, respectively. The crystallite size of the films increased from 18 to 30 nm with Fe concentration (x). The morphology showed the formation of nanorods. The bandgap of the films decreased from 3.94 to 3.81 eV. The X-ray photoelectron spectroscopy (XPS) studies confirm the presence of Fe ions in two different oxidation states (Fe 2+ , Fe 3+ ). The magnetic studies revealed the paramagnetic behavior of the films at room temperature and at low temperature (5 K). The effective magnetic moment (μ eff ) of Fe-doped indium tin oxide thin films was calculated using Langevin theory of paramagnetism extending to Curie’s law. The effective magnetic moment (μ eff ) was increased on increasing the dopant concentration. © 2018, Springer Science+Business Media, LLC, part of Springer Nature.

Journal of Superconductivity and Novel Magnetism

No Signature of Room Temperature Ferromagnetism in Fe-Doped ITO Thin Films

Circular patch antenna for frequency reconfigurable and polarization switching in the antenna using feed configuration is presented. On varying capacitance of the varactor diode from 2.67pF to 0.99pF the antenna tuned from 1.85 to 2.55 GHz impedance bandwidth (32%). The cascaded branch line coupler (BLC) with switching feed configuration is used to achieve polarization reconfiguration (i.e.) vertical linear (VL)/horizontal linear (HL) polarization, RHCP, LHCP in the antenna. The proposed feed network is used to control tunable over a wideband from 1.5 to 3 GHz. The impedance bandwidth of patch antenna is matched with the impedance bandwidth of cascaded BLC feed network to achieve all the performance. © 2019 IEEE.

Department of Communication Engineering

School of Electronics Engineering

Circular Patch Frequency Tunable Antenna with Switching Polarization Feed Configuration

Computer Science

Chennai Campus

Materials Research Innovations

Synthesis, growth and broadband dielectric characterization of nonlinear optical single crystal: 4-methylpyridinium5-sulfosalicylate

Single crystals of potassium pentaborate dihydrate KB5H4O10. 2H2O (KBH) of dimension (10 × 5 × 2 mm3) were successfully grown through the solution growth technique under slow evaporation condition. The crystal structure of potassium pentaborate dihydrate was determined by single crystal X-ray diffraction and the material was crystallized in the orthorhombic system with space group Aba2 with lattice parameters a = 11.13 (Å), b = 11.23 (Å), c = 9.10 (Å), α = β = γ = 90°, volume = 1137 (Å)3. The presence of BO3, BO4 and water molecules were confirmed using Fourier transform infrared (FT-IR) vibrational spectroscopy. The ultraviolet (UV) - visible spectrum reveal the optical and electronic transition properties of the grown crystal. The optical absorption edge of the grown crystal is 210 nm with energy gap of 4.96 eV. The thermogravimetric (TG) and differential scanning calorimetry (DSC) studies showed that the material was stable up to 106 °C, which indicated that the grown crystal could be effectively used for various device applications below the temperature. Vickers microhardness is performed on the grown crystal in the load range from 10 to 50 g. The variation of hardness number with load represents the normal indentation size effect. Mechanical parameters such as yield strength, elastic stiffness constant, fracture toughness, brittleness index and crack propagation of single crystal are discussed in detail. The dielectric behaviour of the single crystal over an extensive range of frequencies and temperature is described. The second harmonic generation (SHG) signal from the KBH crystal is found to be 1.23 mV. © 2018

Materials Chemistry and Physics

Investigation on the growth, optical, mechanical and dielectric properties of an inorganic potassium pentaborate dihydrate (KB5H4O10.2H2O) single crystal

In this present study, we have discussed about the synthesis of spinel type ZnCo2O4 by sol-gel combustion method using glycine as a chelating agent. Structural and morphological verifications are carried out using XRD, SEM and the functional group confirmation by using FT-IR. The temperature dependent dielectric relaxation and conduction mechanism have been analyzed by using dielectric measurements, impedance spectroscopy and electric modulus studies in the frequency range of 50 Hz to 5 MHz between the temperatures 303 K and 593 K. Influence of oxygen vacancy on the behaviour of dielectric relaxation is due to the hopping mechanism between Co2+ and Co3+ sites due to the structural defect in the material. XPS measurement confirms the different oxidation state in Co-site and the existence of oxygen vacancy in the material. The conductivity of the material is studied with Jonscher Power law. © 2018 Elsevier B.V.

Journal of Non-Crystalline Solids

Structural and electrical properties of ZnCo2O4 spinel synthesized by sol-gel combustion method