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The present study provides a comprehensive analysis of the population structure (length–frequency distributions), growth pattern (length–weight relationships [LWRs] and length–length relationships), physiological condition factors (allometric [KA], Fulton's [KF] and relative [KR]), relative weight (WR) and form factor (a3.0) of Chanda nama. A total of 1200 specimens were collected from the Old Brahmaputra River, northeastern Bangladesh, for 12 months by traditional fishing gear, including seine net and cast net. The total length (TL) of several individuals varied from 2.3 to 7.2 cm. The highest percentage contributed to the population's 4.0–4.5‐cm‐sized group. The LWRs indicated a positive allometric growth pattern (b > 3.0). Fulton's condition factor significantly correlated with TL and body weight (p < 0.0001). The calculated WR ranged from 67.38 to 137.64. No significant variations from 100 were found using the Wilcoxon rank test (p = 0.034), suggesting that C. nama might live there in a balanced predator–prey environment. Furthermore, the measured value for the form factor (a3.0) was 0.0105. In addition, fish with a TL of 7–8 cm should be caught since they are in good condition and have enough meat. The study's findings will greatly contribute to the efficient and enduring management of C. nama in the Old Brahmaputra River and its adjacent ecosystems. [ABSTRACT FROM AUTHOR]

Lead-free multiferroic composites of xLi0.1Ni0.2Mn0.6Fe2.1O4 (LNMFO)–(1 − x)BiFeO3 (BFO) were prepared. Multiferroic properties of LNMFO–BFO were analyzed. The compositions are a combination of ferrite and perovskite phases verified by the measurement of X-ray diffraction. FESEM image analyzed the surface morphology of the compositions. The EDX Spectroscopy performed quantitative elemental of the compositions. The μ i ′ increases in the samples with ferrite concentration. Dielectric properties were analyzed with frequency. The change in ε ′ with frequency displays dielectric dispersion in the low frequency zone because of interfacial polarization of Maxwell–Wagner type resulting from the two phase interface. Frequency autonomous behavior of the ε ′ is seen in the higher frequency region as electric dipoles can not follow the rapid change in the alternating electrical field. The ε ′ is reduced with ferrite concentration. Dielectric loss peaks occur when the electrons hopping frequency is almost equal to the applied field frequency. The σ AC of the samples follows the power law of Jonscher and increases with frequency, indicating that there is conduction of small polaron hopping. Impedance spectroscopy studies recommend that the grain and grain boundary perform to the conduction phenomena. Magnetization was measured to study the recompose of the ferrite phase with the magnetic field. Both M s and M r have been increased with ferrite content. The magnetoelectric voltage coefficient is reduced with ferrite concentration. The maximum value of the magnetoelectric voltage coefficient is quite high, up to ~ 98 × 103 Vm−1 T−1 for the composite 0.1LNMFO–0.9BFO. [ABSTRACT FROM AUTHOR]

Zinc-selenide thin film was prepared on a soda-lime glass substrate by thermal vapor deposition technique. The X-ray diffraction data confirmed the cubic zincblende structure with a preferred orientation along (111) plane. Different models such as Debye-Scherrer, Size-Strain plot, Williamson-Hall, uniform stress deformation model and uniform deformation energy density model and the so called approximation model were adopted to analyse the XRD data. Detailed microstructural parameters such as crystallite size, strain, stress, isotropic energy density, dislocation denstiy were reported and discussed in comparison with scanning electron microscopy data. The transmission spectra was obtained by UV-Vis-NIR spectrometer in the range of 250-2500 nm at room temperature. Important optical constantssuch as refractive index and dielectric constant was estimated using Swanepoel's envelope method. The same method was used to check the thin film thickness which was found to be ~374.9 nm and this thickness was further confirmed by Scanning Electron Microscopy (368.3 ± 19.1 nm). The optical band gap was estimated to be 2.64 eV. The dispersion of refractive index was discussed interms of empirical Cauchy dispersion relation and the dispersion was further analysed by Wemple-DiDomenico Single oscillator model which provide physically meaningful parameters such as static refractive index, oscillator energy and dispersion energy. Both the structural and optical data not only complemented each other but also implied that good quality Zinc-selenide thin film could be deposited on ordinary glass substrates. [ABSTRACT FROM AUTHOR]

Improvement in magnetic and electrical properties of multiferroic BiFeO3 in conjunction with their dependence on particle size is crucial due to its potential applications in multifunctional miniaturized devices. In this investigation, we report a study on particle size dependent structural, magnetic and electrical properties of sol-gel derived Bi0.9Ba0.1FeO3 nanoparticles of different sizes ranging from ~ 12 to 49 nm. The substitution of Bi by Ba significantly suppresses oxygen vacancies, reduces leakage current density and Fe2+ state. An improvement in both magnetic and electrica properties is observed for 10% Ba-doped BiFeO3 nanoparticles compared to its undoped counterpart. The saturation magnetization of Bi0.9Ba0.1FeO3 nanoparticles increase with reducing particle size in contrast with a decreasing trend of ferroelectric polarization. Moreover, a first order metamagnetic transition is noticed for ~ 49 nm Bi0.9Ba0.1FeO3 nanoparticles which disappeared with decreasing particle size. The observed strong size dependent multiferroic properties are attributed to the complex interaction between vacancy induced crystallographic defects, multiple valence states of Fe, uncompensated surface spins, crystallographic distortion and suppression of spiral spin cycloid of BiFeO3. [ABSTRACT FROM AUTHOR]