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

1,1,4,4-Tetraphenyl-1,3-Butadiene (TPB) organic scintillation single crystal was grown by solution growth technique. The grown crystal is found to crystallize in monoclinic structure with P21 space group which is ascertained from the single crystal XRD studies. FTIR spectroscopic analysis elucidates the presence of expected vibrational modes of aromatic groups present in TPB material. Results from TG/DSC studies illustrate that the thermal stability of TPB crystal exist up to 232.9&nbsp;°C. The refractive index of the title crystal is revealed to be 1.615. UV–Vis spectral analysis is used to understand the linear excitation property of the crystal. The broad intense peak at 439&nbsp;nm in photoluminescence spectrum of TPB single crystal exhibits its high purity and the emission wavelength. Fluorescence lifetime determined by TCSPC method for TPB crystal shows a short decay time (τ). Etching analysis revealed the regular pattern of etch pits and triangular in shape.

World University root node

School of Advanced Sciences

Vellore Campus

Journal of Materials Science: Materials in Electronics

Growth and characterization of 1,1,4,4-tetraphenyl-1,3-butadiene organic scintillation crystal

Rare-earth ion (Er 3+ ) substituted ZnFe 2−x Er x O 4 nanoparticles at different Er concentrations (x = 0, 0.2, 0.4, 0.6, and 0.8) were synthesized by surfactant (polyethylene glycol) assisted co-precipitation method and studied for structural and magnetic properties of the synthesized nanoparticles. All the ZnFe 2−x Er x O 4 ferrite nanoparticles exhibited an average size of around 25 nm. It was observed that substituent Er 3+ predominantly occupy octahedral sublattice in spinel structure. The crystal lattice unit cell volume and magnetic disorder increased with increase of Er 3+ concentration. The magnetic parameters such as spin-glass or superparamagnetic blocking temperature (T B ), maximum magnetization (M max ), remnant magnetization (M r ) and coercive field (H c ) of the ZnFe 2−x Er x O 4 ferrite nanoparticles decreased with decreasing temperature (3–300 K). High and low magnetizations were observed for the nanoparticles at 3 K and 300 K, respectively. The observed magnetic properties were explained clearly by considering the substitution of Er 3+ ion in to the octahedral sub-lattice and diminishing the magnetic exchange interactions between Fe 3+ ions with [Ar] 3d 5 and Er 3+ ions with [Xe] 4f 11 5d 10 electronic configurations. The present studies confirm that Er 3+ substitution does not enhance magnetic properties of ZnFe 2 O 4 nanoferrites. © 2019, Springer-Verlag GmbH Germany, part of Springer Nature.

Applied Physics A: Materials Science and Processing

Effect of Er 3+ substitution on structural and magnetic properties of narrow size distributed ZnFe 2−x Er x O 4 nanoparticles

Many efforts have been made to understand the effects of hydrogen on titanium alloys, resulting in an abundance of theoretical models and papers. Titanium alloys are crucial advanced materials that provide an excellent combination of a high strength-to-weight ratio and good corrosion behaviour even though they are reasonable to corrosion attack. Titanium alloys are susceptible to hydrogen embrittlement when comes into contact with hydrogen, and galvanic pair with an active metal current, or the pH is greater than 12 or less than 3 or an impressed current. In view of the fact that hydrogen behaves differently with α and β phases, hydrogen degradation may vary markedly in titanium alloys. Hydrogen diminishes the corrosion and erosion resistance and fatigue life of in-service titanium components. A laser peening or laser shock peening is a novel technique for making the metal surfaces and sub-layers densify. It evokes that laser shock peening adoption results in yielding and plastic deformation, thereby creating high compressive residual stresses extending below the surface of the material which is desirable for hydrogen embrittlement resistance and reduction of crack initiation and growth of the component. This article is a review of information relating hydrogen embrittlement of titanium alloys and surface modification technique which influence the strength potential of titanium alloys. © IMechE 2019.

Department of Manufacturing Engineering

School of Mechanical Engineering

Proceedings of the Institution of Mechanical Engineers, Part B: Journal of Engineering Manufacture

A critical appraisal of laser peening and its impact on hydrogen embrittlement of titanium alloys

Aim: Philips recently integrated PlanIQ with Autoplan® in Pinnacle3 TPS (V16.2). The objective of the present work is to quantitatively demonstrate how this integration improves the plan quality. Background: Pinnacle3 Autoplan® is the tool that generates the treatment plans with clinically acceptable plan quality with less manual intervention. In the recent past, a new tool called PlanIQ (Sun Nuclear Corp.) was introduced for a priori estimation of the best possible sparing of an organ at risk (OAR) for a given patient anatomy. Philips has recently integrated PlanIQ tool with Autoplan® for a seamless and efficient planning workflow. Materials and methods: We have performed this evaluation in Pinnacle3 TPS (V.16.2) for the VMAT treatment technique. All plans were created using Varian True beam machine with the dual arc technique. Basically, we created two sets of VMAT plans using 6 MV photons. In the first set of VMAT plans (AP_RTOG), we used OAR goals from either RTOG guidelines to perform optimization using Autoplan®. Subsequently, we exported the same dataset to the PlanIQ system to perform feasibility analysis on the OAR goals. These newly obtained OAR goals from PlanIQ were used to generate the other set of plans (AP_PlanIQ plans). We compared the dosimetric results from these two sets of plans in five cases, such as brain, head &amp; neck, lung, abdomen and prostate. Results: We compared the dosimetric results for AP_RTOG and AP_PlanIQ plans. We used RTOG guidelines to evaluate the plans and observed that while both sets of plans were meeting the RTOG guidelines in terms of OAR sparing, the AP_PlanIQ plans were significantly better in terms of OAR sparing as compared to AP_RTOG plans without any compromise in the target coverage. Conclusion: The results indicate that, although Autoplan helps achieve the user-defined goals without much manual intervention, the plan quality (OAR sparing) can be significantly improved without taking many iterative steps when PlanIQ suggested clinical goals are used in the Autoplan-based optimization. Advances in knowledge: At present, there are no published material available about the efficacy of the integration of PlanIQ with Autoplanning®. In the present work, our objective is to evaluate the improvements in plan quality resulting from this integration. © 2019 Greater Poland Cancer Centre

Fulltext

Reports of Practical Oncology and Radiotherapy

Evaluation of plan quality improvements in PlanIQ-guided Autoplanning

Terahertz time-domain spectroscopy (THz-TDS) is a non-invasive, non-contact and label-free technique for biological and chemical sensing as THz-spectra are less energetic and lie in the characteristic vibration frequency regime of proteins and DNA molecules. However, THz-TDS is less sensitive for the detection of micro-organisms of size equal to or less than λ/100 (where, λ is the wavelength of the incident THz wave), and molecules in extremely low concentration solutions (like, a few femtomolar). After successful high-throughput fabrication of nanostructures, nanoantennas were found to be indispensable in enhancing the sensitivity of conventional THz-TDS. These nanostructures lead to strong THz field enhancement when in resonance with the absorption spectrum of absorptive molecules, causing significant changes in the magnitude of the transmission spectrum, therefore, enhancing the sensitivity and allowing the detection of molecules and biomaterials in extremely low concentration solutions. Herein, we review the recent developments in ultra-sensitive and selective nanogap biosensors. We have also provided an in-depth review of various high-throughput nanofabrication techniques. We also discussed the physics behind the field enhancements in the sub-skin depth as well as sub-nanometer sized nanogaps. We introduce finite-difference time-domain (FDTD) and molecular dynamics (MD) simulation tools to study THz biomolecular interactions. Finally, we provide a comprehensive account of nanoantenna enhanced sensing of viruses (like, H1N1) and biomolecules such as artificial sweeteners which are addictive and carcinogenic. © 2019 The Royal Society of Chemistry.

Analyst

Nanoantenna enhanced terahertz interaction of biomolecules

The survey focuses on the most significant contributions in the field of fiber optic plasmonic sensors (FOPS) in recent years. FOPSs are plasmonic sensor-based fiber optic probes that use an optical field to measure the biological agents. Owing to their high sensitivity, high resolution, and low cost, FOPS turn out to be potential alternatives to conventional biological fiber optic sensors. FOPS use optical transduction mechanisms to enhance sensitivity and resolution. The optical transduction mechanisms of FOPS with different geometrical structures and the photonic properties of the geometries are discussed in detail. The studies of optical properties with a combination of suitable materials for testing the biosamples allow for diagnosing diseases in the medical field.

Applied Sciences

Recent Advances in Plasmonic Sensor-Based Fiber Optic Probes for Biological Applications

Purpose: To find an optimal arc design for hybrid volumetric modulated arc therapy (H-VMAT), a combination of conventional 3DCRT and VMAT plans for left-sided whole breast radiation therapy. Methods and materials: A total of 26 left-sided early-stage breast cancer patients were selected for this study. To find the superior plan, H-VMAT with three different arc designs including, two partial arcs (2A), four partial arcs (4A) and four tangential arcs (TA) were created for each study case by combining 3DCRT and VMAT with 75% 3DCRT/25% VMAT dose proportion of prescription dose. Results: All H-VMAT plans achieved the expected target coverage. A higher conformity index and homogeneity index were achieved for 2A and 4A H-VMAT plans and significantly differ from TA H-VMAT (p &lt; 0.003). The heart and ipsilateral lung dose parameters were comparable among all plans except heart V40Gy which was significantly less in 4A H-VMAT plan (p &lt; 0.05). The contralateral lung, contralateral breast, spinal cord, normal tissue doses and MU were significantly less in TA H-VMAT (p &lt; 0.03). The beam-on time was significantly less in 2A H-VMAT (p &lt; 0.0001). Conclusion: 2A and 4A H-VMAT techniques are effective in improving the PTV dosimetric parameters as well as reducing the OAR doses. Further, 2A H-VMAT delivers less MU and beam-on time compared to 4A H-VMAT. © 2019, Italian Society of Medical Radiology.

Radiologia Medica

Hybrid volumetric modulated arc therapy for whole breast irradiation: a dosimetric comparison of different arc designs

Hydroxyapatite (HAp) is a bioceramic known for bone applications due to its physical and chemical properties similar to the human bone. In this present study, HAp nanopowder was synthesised using chemical precipitation method in the presence of polymers Joncryl61 (acrylic resin) and gelatin (biopolymer). The crystalline nature of synthesised pure and polymer-added hydroxyapatite was confirmed by powder X-ray diffraction pattern and the FTIR pattern peaks present at 604–624 cm −1 revealing the presence of phosphate phase. Morphological studies using SEM revealed the presence of rod-shaped, agglomerated rod-shaped and rod shape with small sphere dumbbell structure in pure HAp, HAp with Joncryl61 and HAp with gelatin respectively. The dielectric properties of pure and polymer-doped HAp were also examined at room temperature with frequency from 50 to 5,000,000 Hz. The dielectric constant and loss were found to be maximum when the frequency was low. © 2018, Australian Ceramic Society.

Journal of the Australian Ceramic Society

Effect of Joncryl61 and gelatin in the formation of hydroxyapatite nanocomposite

We propose a simple geometric, highly responsive and miniaturized surface plasmon polariton microbiosensor using a photonic quasicrystal fiber. Here, we consider gold as plasmonic material as the external coating for exciting the surface plasmon to detect the refractive index of the external analyte sensing to facilitate the practical realization. Further, we carry out detailed characteristics evaluations such as wavelength and amplitude sensitivities, resolution, full-width at half maximum, the figure of merit, signal to noise ratio and detection limit for both 6-fold and 8-fold plasmonic sensors. The proposed 6 and 8-fold sensors show a maximum sensitivity of 28,000 nm/RIU for an analyte range of 1.41–1.42 and 27,000 nm/RIU for an analyte range of 1.4–1.41, respectively. While the figure-of-merit of the 6-fold sensor is 491, for the 8-fold sensor, it is 231. Besides, the structural parameters and the arrangements of the air-holes in cladding region add to the sensing performance. The proposed sensing systems operate for a wide range of wavelengths from 600 to 1300 nm. Thus, the proposed sensors might turn out to be promising candidates for the refractive index-based biological and chemical detections. © 2019 The Authors