Publications by authors named "Unnikrishnan N"

In this work we have studied the fluorescence of natural dyes and generated nearly pure white light with chromaticity intensity (CIE) coordinate (0.35,0.35).

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Objectives: Revision hip arthroplasty is a major surgical challenge and is even more difficult in cases with a deficient proximal femur. Modular uncemented cone body revision femoral stems were introduced as a solution. They have the advantage of optimising joint kinematics by allowing the variable degrees of version, offset and leg length.

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In the present communication, we propose a quantile-based measure for the divergence between two survival functions. This can also be used in a dynamic way where the divergence between survival functions varies with time. Several new properties of the proposed measure are investigated with suitable examples.

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The mushrooming utilization of electronic devices in the current era produces electromagnetic interference (EMI) capable of disabling commercial and military electronic appliances on a level like never before. Due to this, the development of advanced materials for effectively shielding electromagnetic radiation has now become a pressing priority for the scientific world. This paper reviews the current research status of polymer nanocomposite-based EMI shielding materials, with a special focus on those with hybrid fillers and MXenes.

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Eu doped silica-titania-polydimethylsiloxane hybrid ORMOSILs were synthesized a non-hydrolytic sol-gel route. The structural and thermal analyses of the samples confirmed that the matrix structure remains unaffected by doping with different concentrations of Eu ions. Photoluminescence (PL) studies performed at 394 nm on Eu doped ORMOSILs imply that they emit broad blue host emission and the characteristic Eu red emissions simultaneously.

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A thick coating of hierarchically porous double-templated TiO-ZrO-PMMA-PF127 with excellent self-cleaning properties and high transmittance has been developed for the first time on glass substrates using a simple dip-coating technique. Comparative studies of this sample with a thick and transparent coating of single-templated TiO-ZrO-PMMA have been performed to probe the origin of its exceptional properties. The formation of the composites, successful incorporation of the polymer into the matrix, and the porous nature of the films have been studied.

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The structural features leading to the intense quenching free luminescence exhibited by europium oxalate nanocrystals, poly[[hexaaquatri-μ-oxalato-dieuropium] 4.34-hydrate], {[Eu(CO)(HO)]·4.34HO}, is the focal point of this report.

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Nanostructuring followed by incorporation of defect induced non-stoichiometry is an emerging field of prominence due to its capacity to introduce unprecedented properties in materials with potential applications. In this work, crystalline α-MnO nanorods are synthesised using a facile co-precipitation method to exhibit ferroelectric behaviour for the first time. The evolution mechanism of the nanorods is investigated using XRD, HRTEM and FTIR spectra, while their thermal stability is probed using TGA/DTA.

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A three-month-old female infant presented with abdominal distention for 2 months. A large palpable mass in right upper quadrant was noted on physical exam. Abdominal ultrasound revealed a large heterogeneous mass with multiple cystic components.

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Samarium doped sodium bismuth silicate glass was synthesized using the melt quenching method. Detailed optical spectroscopic studies of the glassy material were carried out in the UV-Vis-NIR spectral range. Using the optical absorption spectra Judd-Ofelt (JO) parameters are derived.

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Multicomponent tellurite glasses containing altered concentrations of Er2O3 (ranging from 0 to 1 mol%) were prepared by the standard melt quenching technique. Investigations through energy dispersive X-ray spectroscopy (EDS), Raman scattering spectroscopy, Fourier transform infrared (FTIR) spectroscopy, near-infrared (NIR) emission studies and dielectric measurement techniques were done to probe their compositional, structural, spectroscopic and dielectric characteristics. The broad emission together with the high values of the effective linewidth (~63 nm), stimulated emission cross-section (9.

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Silver nanoparticles were dispersed in the pores of monolithic mesoporous silica prepared by a modified sol-gel method. Structural and microstructural analyses were carried out by Fourier transform infrared spectroscopy and transmission electron microscopy. X-ray photoelectron spectroscopy was employed to determine the chemical states of silver in the silica matrix.

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The spectroscopic properties of trivalent samarium doped Sr0.5Ca0.5TiO3 perovskite phosphor material (Sr0.

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The spectroscopic and photoluminescence characteristics of trivalent dysprosium (Dy(3+))-doped Sr0.5Ca0.5TiO3 phosphor materials synthesized via solid-state reaction method were studied.

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Terbium molybdate nanophosphors were synthesized through a facile sol-gel route. The structure of the phosphors was characterized by X-ray diffraction, Raman spectra and Fourier transform infrared spectroscopy analysis. The X-ray diffraction studies revealed that the structure of the nanophosphor gradually changes from monoclinic to orthorhombic phase as heated from 700 to 900 °C.

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Er(3+)-doped Li-Zn fluoroborate glass was synthesized via melt quenching technique. Optical properties of the glass were investigated by UV-Vis-NIR absorption and emission spectra. To evaluate the nature of Er(3+)-ligand bond in the glass network, nephelauxetic ratios and bonding parameter were calculated.

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An implant-supported crown or conventionally fixed partial denture is the most common treatment modality to replace a missing anterior tooth but a more conservative approach, with a fiber reinforced composite resin FPD, can be used to replace a missing anterior tooth in young patients or when the patient does not agree for an implant, or conventional FPD or RPD therapy. It is an esthetic, conservative single sitting chairside procedure which can be used as a definitive treatment alternative in certain clinical situations for esthetic and functional replacement of a missing anterior tooth. To achieve desirable results, putty matrix was used for proper positioning of the pontic during direct fabrication of FRCFPD.

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Luminescence properties of Pr(3+) activated Sr1.5Ca0.5SiO4 phosphors synthesized by solid state reaction method are reported in this work.

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Nanostructured samarium oxalate crystals were prepared via microwave assisted co-precipitation method. The crystal structure and morphology of the sample were analyzed using X-ray powder diffraction, Scanning electron microscopy and Transmission electron microscopy. The presence of functional groups is ascertained by Fourier transform infrared spectroscopy.

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ZnO thin films are grown on quartz substrates at various substrate temperatures (ranging from 573 to 973 K) under an oxygen ambience of 0.02 mbar by using pulsed laser ablation. Influence of substrate temperature on the structural, morphological, optical and electrical properties of the ZnO thin films are investigated.

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Extensive bilateral midfacial defects involving the upper jaw, palate, and sinus present a formidable reconstructive challenge. A combination of total and subtotal maxillectomy is, in general, a rare surgical procedure that affects the cosmetic, functional, and psychological aspects of a patient's life. Prosthetic restoration has become the preferred method for the rehabilitation of such conditions.

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Atomic Force Microscopy complemented by Photoluminescence and Reflection High Energy Electron Diffraction has been used to study self-assembly of silver nanoparticles and multiwall carbon nanotubes on thermally decomposed GaAs (100) surfaces. It has been shown that the decomposition leads to the formation of arsenic plate-like structures. Multiwall carbon nanotubes spin coated on the decomposed surfaces were mostly found to occupy the depressions between the plates and formed boundaries.

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xDNA is a modified DNA, which contains natural as well as expanded bases. Expanded bases are generated by the addition of a benzene spacer to the natural bases. A set of AMBER force-field parameters were derived for the expanded bases and the structural dynamics of the xDNA decamer (xT5' G xT A xC xG C xA xG T3').

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The title compound, C(15)H(12)N(2)OS(2), is an example of a push-pull butadiene in which the electron-releasing methyl-sulfanyl groups and electron-withdrawing nitrile groups on either end of the butadiene chain enhance the conjugation in the system. Short intra-molecular C-H⋯S inter-actions are observed. In the crystal structure, an O⋯C short contact of 2.

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Cadmium sulfide semiconductor nanoparticles along with terbium ions were incorporated in silica xerogels through sol-gel route. The optical absorption and emission spectra confirmed the formation of CdS nanoparticles along with terbium ions in the silica gel. The optical bandgap and size of the CdS nanoparticle were calculated from the absorption spectrum.

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