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Thunderstorms are natural disasters that impact people, animals, and the economy. Thunderstorms' detrimental repercussions can be avoided by identifying their occurrence in advance. The current work, in this respect, uses soft computing techniques such as K-Nearest Neighbour (KNN), Decision Tree (DT), Logistic Regression (LR), and Support Vector Machine (SVM) with various kernel functions to categorize the occurrence of thunderstorms over Ranchi, India. These techniques were trained and tested using two data sets: daily average and hourly meteorological datasets. The primary purpose of this study is to find which dataset-classifier combination is optimal for categorizing thunderstorm occurrence in Ranchi. No classifier was found to adequately classify either the Day Average Dataset or the Modified Day Average Dataset. On the other hand, the Hourly Dataset was found to be more balanced in terms of the number of thunderstorms that occurred than the Day Average and Modified Average datasets. The F-Score value of the incidence of thunderstorm incidents after using different classifiers was used to compare the outcomes of these datasets. The results reveal that using SVM with radial basis function. The Hourly Dataset is the best for thunderstorm day classification. For the overall and only incidence of thunderstorms classes, SVM-RBF gets 0.81 and 0.74 F-Scores, respectively. Other approaches, like grid search and Bagging, have been used to increase SVM-RBF performance. Grid search and Bagging are used on SVM-RBF to produce a hybrid Grid-Bag-SVM-RBF classifier with 82.04% accuracy and F-scores of 0.83 and 0.78 for overall and just thunderstorm occurrence, respectively. [ABSTRACT FROM AUTHOR]

The present study depicts, synthesis and physicochemical investigations of zinc oxide nanoflowers (ZnO NFs). X-ray diffraction (XRD) profile of ZnO NFs revealed that ZnO NFs exhibit hexagonal wurtzite-type structure of crystallinity with P63mc space group. Microstructural analysis displays a uniform flower-like shape of ZnO NFs with petals ranging from 1 to 2 μm and an overall size of 12 µm. The absorption spectrum of ZnO NFs showed characteristic peak at 365.7 nm with an optical energy band gap of 3.40 eV. The photocatalytic activity of the ZnO NFs was evaluated by exposing crystal violet (CV) dye to UV light in the presence of the ZnO NFs. The UV–Vis spectra showed a significant decrease in the intensity of the absorbance peak at ~ 590 nm, corresponding to the degradation of the dye. The degradation followed a first-order rate equation with a rate constant of 0.0404 min−1 and excellent fit to the experimental data (R2 = 0.987). Furthermore, the ZnO NFs displayed excellent reusability, with more than 90% removal efficiency after 5 cycles. These findings demonstrate the potential of ZnO NFs as an effective photocatalyst for removing toxicity from aqueous solutions. Hall effect measurements revealed the n-type character of ZnO NFs and their resistivity, carrier concentration and Hall mobility were found to be 29 Ω cm, 7.53 × 106 cm−3, and 2.48 cm2/V s, respectively. [ABSTRACT FROM AUTHOR]

The room temperature and magnetic field-dependent dielectric, impedance and magnetoelectric (ME) coupling effect of polycrystalline AFe2O4/(Pb0.80Sr0.20)TiO3 (A = Mn, Ni and Co) bi-layered composite films have been investigated. The structural and microstructural analyses using the X-ray diffraction (XRD), atomic force microscopy (AFM) and scanning electron microscopy (SEM) reveal the presence of homogenous growth of both tetragonal and spinel phases without any extra phase and diffusion in the AFO/PST20 bi-layered composite films. Our results show that all composite films exhibit ferroelectric as well as considerable magnetic, indicating magnetoelectric coupling effect. Our results show that the dielectric and impedance properties of AFO/PST20 bi-layered composite films can be manipulated by the magnetic field at room temperature, also indicating the existence of magnetoelectric coupling. The impedance (Z′ and Z″) Nyquist plots show distinct electrical responses with the magnetic field. The maximum magnetoelectric coefficient (α) is found to be αME∼ 239 and ∼ 195 mV/cm/Oe for the MFO/PST20 and CFO/PST20 bi-layered composite films, respectively. The above results show that the AFO/PST20 bi-layered composite films are room-temperature multiferroic material that can be potentially used in magnetoelectric devices. [ABSTRACT FROM AUTHOR]

We prepared NiFeO/(Pb, Sr)TiO (NFO/PST) bilayer films by the chemical solution method and investigated their multiferroic, magnetoelectric and magneto-impedance properties. Multiferroic properties have been observed at room temperature. The bilayer films exhibit saturation polarization P ̴ 26.6 μC/cm and saturation magnetization M ̴ 134 emu/cm. With increasing Sr content, M and P values of the NFO/PST bilayer films decrease. The variation may be ascribed to the influence of interfacial strain and decrease in tetragonality. High magnetoelectric coupling effect has been observed in the NFO/PST bilayer films with maximum value of α = 6.35 Vcm Oe measured at H ~ 1 kOe and f ~ 10 kHz for Sr ~ 10% (NFO/PST10). The magneto-impedance measurements establish a strong dependence on magnetic field, further confirming magnetoelectric response in NFO/PST bilayer films. An alternative approach for impedance analysis of NFO/PST10 bilayer film provides direct evidence of strain mediated magnetoelectric coupling at room temperature. The results indicate that NFO/PST bilayer films can be considered as a potential multiferroic magnetoelectric material. [ABSTRACT FROM AUTHOR]