Investigations on the structural and optical properties of the swift heavy ion irradiated 6HSiC

Single crystal 6HSiC wafers have been irradiated with 150 MeV Ag¹²⁺ ions with fluences ranging from 1 × 10¹¹ to 1 × 10¹³ ions/cm² at 300 K. The defect accumulation as a function of fluence was studied to determine changes in structural and optical properties. The variation in the fundamental Raman modes of the crystalline 6HSiC due to irradiation has been correlated with the disorder accumulation. The creation of defect states due to irradiation in the bandgap affects the blue-green photoluminescence emission in the irradiated samples. The UV-Visible absorption studies support the existence of defect states in the bandgap which is observed by the shift in the absorption edge towards the lower energy side with increasing fluence. Time Correlated Single Photon Counting photoluminescence decay results suggest that the existing defect states are radiative, exhibiting three lifetimes when irradiated with a fluence 5 × 10¹¹ ions/cm². The total number of lifetime components was reduced for a fluence 1 × 10¹³ ions/cm² as the defect states produced increase the non-radiative defect centres. These results suggest that the accumulation of defects due to irradiation at fluences 5 × 10¹¹ and 1 × 10¹³ ions/cm² are degenerate configurations which exhibit multiple lifetimes in photoluminescence studies. It is inferred that the optically active defect states influence the transition rate of charge carriers in this device material.     

Synthesis,defect characterization and photocatalytic degradation efficiency of Tb doped CuO nanoparticles

Monoclinic undoped and Tb doped CuO are prepared by solution combustion method and annealed at different temperatures. The effect of annealing and doping on their structural and optical properties of CuO are examined using XRD, FTIR and DRS. The surface and lattice defects in CuO and Tb doped CuO is analyzed qualitatively and quantitatively using positron lifetime and Doppler broadening spectroscopy. The average positron lifetime and electron momentum (energy) S parameter increases owing to the number of vacancies in the CuO lattice upon doping and decreases with increasing temperature. The migration of vacancies from grain to grain boundary region is observed at 600 °C annealed samples. At 800 °C, the overall behavior of lifetime value denotes that the vacancy type defect is recovered, cluster vacancy and microvoids exists with reducing size. The photocatalytic performance of undoped and Tb doped CuO on degradation of methylene blue (MB) and methyl orange (MO) is investigated under visible light for two different lamp power and dye concentration. The influence of annealing temperature and dopant ion on the efficiency is also elaborated. Enhanced photocatalytic efficiency in Tb doped CuO is observed upon annealing. X-ray photoelectron spectroscopy (XPS) result indicates that the valence states of Cu, O and Tb ions exist at the surface of the particles. Brunauer–Emmett–Teller N₂ adsorption–desorption analyses were employed to characterize specific surface area and porosity of Tb doped CuO. The doped CuO with pore size of about ～34 nm have a surface area of 16–28 m²/g. The surface area effect plays an important role in the enhanced catalytic performance on Tb doped catalysts.     

Simplification of English and Bengali Sentences for Improving Quality of Machine Translation

Neural Processing Letters - Training translation systems with complex and compound sentences are generally considered computationally tough and such systems fail to process, the large syntactical...     

Multimodal mood classification of Hindi and Western songs

Music mood classification is one of the most interesting research areas in music information retrieval, and it has many real-world applications. Many experiments have been performed in mood classification or emotion recognition of Western music; however, research on mood classification of Indian music is still at initial stage due to scarcity of digitalized resources. In the present work, a mood taxonomy is proposed for Hindi and Western songs; both audio and lyrics were annotated using the proposed mood taxonomy. Differences in mood were observed during the annotation of the audio and lyrics for Hindi songs only. The detailed studies on mood classification of Hindi and Western music are presented for the requirement of the recommendation system. LibSVM and Feed-forward neural networks have been used to develop mood classification systems based on audio, lyrics, and a combination of them. The multimodal mood classification systems using Feed-forward neural networks for Hindi and Western songs obtained the maximum F-measures of 0.751 and 0.835, respectively.     

Low resource language specific pre-processing and features for sentiment analysis task

Language Resources and Evaluation - Sentiment analysis is a classification task where polarity of textual data is identified, i.e. to analyze whether a sentence or document expresses a negative,...     

Topology-based denoising of chaos

In this article, we propose a denoising algorithm to denoise a time series y _i = x _i + e _i , where {x _i } is a time series obtained from a time-T map of a uniformly hyperbolic or Anosov flow, and {e _i } a uniformly bounded sequence of independent and identically distributed (i.i.d.) random variables. Making use of observations up to time n, we create an estimate of x _i for i < n. We show under typical limiting behaviours of the orbit and the recurrence properties of x _i , the estimation error converges to zero as n tends to infinity with probability 1.     

A critical review on diagnosis of diabetic retinopathy using machine learning and deep learning

Multimedia Tools and Applications - Diabetic Retinopathy (DR) is a health condition caused due to Diabetes Mellitus (DM). It causes vision problems and blindness due to disfigurement of human...