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

Chemistry

We report a facile one-pot synthesis of the multi-shaped anisotropic plasmonic Ag nanostructures (Mx-AgNPs) and demonstrated for the broadband plasmonic enhancement in dye-sensitized solar cells (DSSCs). The UV–Vis spectra obtained during the synthesis of AgNPs revealed the fine-tuning of the surface plasmon resonance (SPR) peak and the occurrence of broadband multiple SPR peak with an increase in reaction time. The TEM images confirm the collective presence of different shapes/sizes of the Ag nanoparticles (including sphere, oval, polygon, triangular, rod and some irregular morphologies). The resultant ultra-broadband LSPR from the Mx-AgNPs were utilized to improve the total light absorption coefficient of N719 dye. We observed that the photoanode film incorporated with of Mx-AgNPs enhances light harvesting of the dye up to 60% over an entire visible region. The effects of Mx-AgNPs in the photoanode film on the efficiency and the spectral response of the DSSCs were further evaluated experimentally. Substantial improvement with the considerable broadening in the spectral response was observed in the ‘incident photon- to current conversion efficiency’ (IPCE) spectra for the plasmonic DSSCs. The ‘power conversion efficiency’ (PCE) for the best performing plasmonic DSSCs found to improve by ~ 30% for the plasmonic DSSCs. The observed improvement in the efficiency was mainly attributed to the significant enhancement of the light harvesting capacity of the DSSCs resulted by ultra-broadband surface plasmon resonance of the Mx-AgNPs. © 2018 Elsevier B.V.

World University root node

School of Advanced Sciences

Chennai Campus

Solar Energy Materials and Solar Cells

Facile one-pot synthesis of multi-shaped silver nanoparticles with tunable ultra-broadband absorption for efficient light harvesting in dye-sensitized solar cells

We present a detailed study on the photovoltaic performance of dye and quantum dot (QD) sensitized solar cells fabricated using nanoporous TiO2 photoanodes prepared by a template approach. Nanoporous TiO2 particles (TNPO) are prepared by sol-gel method using dextran (TNPO-D) and glucose (TNPO-G) as templates. The decomposition of templating agents during calcination introduces nanopores (∼10 nm) in TiO2 nanoparticles as evidenced from the HRTEM studies. Oxygen vacancies are also introduced in TiO2 nanoparticles due to prevailing reducing ambient during decomposition. Oxygen vacancy (VO) related defects are evidenced from EPR spectra from a strong absorption signal observed at g-value of 1.994 related to Ti3+-VO-Ti3+ defect sites. The defect concentration estimated from EPR spectra is found to be ∼5 to 15 times larger for nanoporous TiO2 particles compared to Degussa P25-TiO2. TNPO samples also show enhanced defect level photoluminescence emission. The photovoltaic efficiency (η) and the IPCE of DSSC and QDSSC are strongly influenced by the defect concentration and seen to decrease with increasing VO in TiO2 nanoparticles. Twofold lower η is found in both DSSC (∼6.38% to 3.66%) and QDSSC (∼1.69% to 0.46%) devices made using nanoporous TiO2 compared to P25-TiO2 photoanode solar cells. P25-TiO2 also shows significant decrease in η when oxygen vacancies are introduced by hydrogen annealing process, which reveal detrimental effect of VO on the photovoltaic properties. EIS studies suggest increased interfacial resistance in solar cells made from nanoporous TiO2 photoanodes. © 2017 Elsevier Ltd

Solar Energy

Template assisted nanoporous TiO2 nanoparticles: The effect of oxygen vacancy defects on photovoltaic performance of DSSC and QDSSC

Speech enhancement is used to improve the quality of the speech by reducing and removing the unwanted noise. The ultimate goal of this work is to improve the quality of the speech by increasing the clearness of the voice by reducing the background noise for the purpose of feature extraction. This paper dealing with few existing algorithms and novel proposed approach for noise filtering. Here the noise enhancement is done by two levels, with High Band Pass Filtering and Winner Filtering algorithms. Results are shown feature extraction after two way filtering produces better results than one way filtering approach. © 2017 IEEE.

Computer Science

School of Computer Science and Engineering

2017 International Conference on Energy, Communication, Data Analytics and Soft Computing (ICECDS)

Two level filtering using high band pass and Winner algorithms for speech enhancement

Condition monitoring and predictive maintenance play a key role in the maintenance of an electrical machine. In this study, to monitor the condition of the induction machine, torque is predicted from the acquired acoustic signals. The acoustic signals collected from different locations of an induction motor are analysed using dyadic wavelet transform for various load conditions. The predicted torque is computed using multiple regression method by extracting the root mean square and mean statistical features of the processed acoustic signal. The percentage error is approximately 5-10% at different location validating the feasibility of using acoustic signals for condition monitoring of machines. In addition, the harmonics induced in the healthy machine due to various acoustic sources is verified using acoustic spectrum. Also, using Pseudo spectrum MUltiple SIgnal Classification algorithm, the pattern and peak decibel for the acquired acoustic signal at different locations are analysed. For any number of samples, the patterns are unique for each location at different speeds. The results obtained validate that pattern analysis method can also be used for condition monitoring and predictive maintenance in electric machines. © 2017, The Institution of Engineering and Technology.

Electrical

School of Electrical Engineering

IET Signal Processing

Dyadic wavelet transform-based acoustic signal analysis for torque prediction of a three-phase induction motor

A series of four new copper(II) heteroleptic complexes, [Cu(2‴-pytpy) (L)] (NO3)2·2H2O (1-4), where 2‴-pytpy=4'-(2'''-Pyridyl)-2, 2':6', 2''-terpyridine, L=bipyridyl (bpy), 1, 10 phenanthroline(phen), dipyridoquinoxaline(dpq) and dipyridophenazine (dppz) were synthesized and characterized by spectroscopic techniques. Further, the molecular structure of the complex (2) was confirmed by single crystal X-ray diffraction technique and the data revealed a penta coordinated, distorted square-pyramidal geometry with triclinic system. The interactions of four complexes with calf thymus DNA and bovine serum albumin (BSA) were investigated by electronic absorption, fluorescence and circular dichroism spectroscopy techniques. Spectral studies substantiated an intercalative binding mode of metal complexes with ct-DNA. Significant binding interactions of the complexes with protein have been further revealed from fluorescence studies. Furthermore, all the four complexes show potential cytotoxicity towards the human liver carcinoma cell line (HepG-2).

VIT Unitversity

Department of Chemistry

Vellore Campus

International Journal of Biological Macromolecules

Evaluation of DNA/Protein interactions and cytotoxic studies of copper(II) complexes incorporated with N, N donor ligands and terpyridine ligand

A series of amidinate-based N,O-chelated magnesium complexes [(L1)2(THF)2Mg] (1), [(L2)2(THF)2Mg] (2), [(L3)2(THF)2Mg] (3), and [(L4)2Mg] (4) were prepared by treating N-benzoyl-N′-arylbenzamidines (L1-4H) with 0.5 equiv of di-n-butylmagnesium in THF. Analogous CH3CN-coordinated complexes [(L1)2(CH3CN)2Mg] (5) and [(L3)2(CH3CN)2Mg] (6) were prepared in a similar way using CH3CN as solvent. All of the compounds were characterized by 1H/13C NMR spectroscopy, and the molecular structures of 1, 2, and 4-6 were further confirmed by single-crystal X-ray diffraction studies. Complexes 1, 2, 5, and 6 displayed good catalytic activity toward the ring-opening polymerization (ROP) of ϵ-caprolactone. In addition, 1, 5, and 6 were also found to be excellent catalysts for making cyclic carbonates from CO2 and epoxides in the presence of a cocatalyst, n-Bu4NBr. © 2017 American Chemical Society.

Organometallics

N-Benzoylbenzamidinate Complexes of Magnesium: Catalysts for the Ring-Opening Polymerization of ϵ-Caprolactone and CO2/Epoxide Coupling

Oxidative addition of oxamide ligands (H2L = N,N′-diphenyloxamide, and N,N′-dibenzyloxamide) to rhenium carbonyl (Re2(CO)10) in the presence of flexible ditopic pyridyl ligands having polyether spacer (L′ = 4-pyridinecarboxylic acid diethylene glycol diester and 4-pyridinecarboxylic acid tetraethylene glycol diester) afforded dirhenium(I) metallacrown ethers of general formula [(CO)3Re(μ-L)(μ-L′)Re(CO)3] (1–3). The fac-Re(CO)3core based dinuclear metallacycles were obtained in one-pot reaction via four-component heteroligand self-assembly under solvothermal conditions. Compounds 1–3 were characterized using elemental analyses, IR, UV–Vis and NMR spectroscopic techniques. Formation of 1 was ascertained by ESI mass analysis, while structural elucidation of 2 and 3 was carried out using single-crystal X-ray diffraction methods. Structural studies revealed a dinuclear framework in which two fac-Re(CO)3units are connected together by a bridging oxamide ligand via ON∩NO bis-chelation and a pyridyl ditopic tecton tethered with flexible polyether spacer by Re[sbnd]N coordination in an orthogonal fashion. © 2016 Elsevier B.V.

Journal of Organometallic Chemistry

Oxamidato pillared heteroligated dirhenium(I) metallacrown ethers: Synthesis, spectroscopic and structural characterization

Purpose: To evaluate the comparative oral bioavailability of Itraconazole capsule 100mg upon administering single dose to adult, healthy, human subjects in fed state by different bioequivalence approaches like average bioequivalence, population bioequivalence and individual bioequivalence and to monitor the safety of subjects upon administration of test and reference formulations. Methods: An open label, balanced, randomized, two-treatment, two-sequence, four-period (fully replicated), crossover, single dose comparative oral bioavailability study was conducted in 16 healthy, adult, human subjects in fed state. Test product, Itraconazole capsule 100mg and reference product, SPORANOX® (Itraconazole) capsule 100mg were administered in fed state. Findings: The test product, Itraconazole capsule 100mg showed bioequivalence against reference product, SPORANOX® (Itraconazole) capsule 100mg in healthy subjects under fed state. Also, the test product exhibited similar safety and tolerability profile compared to reference product. There were no reports of serious adverse events and deaths in the course of study conduct. Conclusions: The test product was found to be bioequivalent to reference product in healthy human subjects under fed state by evaluating different bioequivalence approaches like average bioequivalence, population bioequivalence and individual bioequivalence. © 2017 Pharmainfo Publications. All rights reserved.

Journal of Pharmaceutical Sciences and Research

Assessment of comparative bioavailability of Itraconazole capsule 100mg in healthy subjects under fed conditions by using multiple bioequivalence approaches

Optically active single crystals of L-phenylalanine D-methionine (LPDM) were grown by slow evaporation technique by co-crystallization of amino acids L-phenylalanine and D-methionine in water. The unit cell dimensions have been identified from single crystal X-ray diffraction technique. The existences of various hydrocarbyls were examined by FTIR and FT-Raman spectroscopy. The carbon and hydrogen environment of the grown crystals were analyzed by FT NMR spectrum. The optical absorption studies show that the crystal is transparent in the visible region with a lower cut-off wavelength of 259 nm and there by optical band gap energy Eg is calculated to be 5.35 eV. The Urbach energy, extinction coefficient, reflectance were calculated from UV-absorption data. Further, the thermal stability and accurate melting point has been investigated by TG/DSC techniques. The Kurtz powder SHG was confirmed using Nd:YAG laser with fundamental wavelength of 1064 nm. The dielectric behavior of the specimen has been determined for various temperatures (313 K, 333 K, 353 K, 373 K) at different frequencies. Fluorescence study and the time resolved decay calculation was also performed for the LPDM crystal. Optical nonlinear susceptibility was measured in LPDM and the real and imaginary part of χ3 was evaluated by Z-scan technique using open and closed apertures. © 2017 Elsevier B.V.

Department of Digital Communications

School of Information Technology and Engineering

Physics

Physica B: Condensed Matter

Growth and characterization of an efficient new NLO single crystal L -phenylalanine D -methionine for frequency conversion and optoelectronic applications

Different organic compounds are evaluated to form back contact for CdTe photovoltaics (PV) and to study the effect of band alignment. CdTe devices with CdS n-type window layer were fabricated using closed space sublimation (CSS) and organic back contact layers were deposited using dip coating. In order to prepare photovoltaic devices, the appropriate deposition parameters and thicknesses of organic compounds were selected experimentally. The best results were obtained with dip coated PEDOT-PSS aqueous dispersion with high electrical conductivity. The performance of devices with organic back contacts are compared to those with baseline CdTe devices with reduced copper doping. © 2017 IEEE.