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A series of Pb doped CeO2 nanocubes with seven different Pb loadings (2–12 mol%) were synthesized via modified hydrothermal technique. The prepared samples were characterized by XRD, XPS, FT-IR, TGA, SEM, HR-TEM, EDS and UV–Vis DRS analysis. According to XRD analysis, the crystalline structure of synthesized pure CeO2 and Pb-doped CeO2 samples are cubic structure. The ceria nanocubes showed an increase in amount of oxygen vacancies with increasing the dopant concentrations. When the doping level of Pb is 6 mol%, the optical band gap of Pb-CeO2 is smaller than that of pure CeO2 nanocubes. The HR-TEM results confirms the cubic structure of 6% Pb-CeO2 with average crystallite size of about 15 nm. The photocatalytic ability of Pb-CeO2 catalysts were studied by degrading several anionic and cationic organic pollutants like methylene blue (MB), methylene orange (MO), methylene red (MR), rhodamine B (RhB), reactive blue 160 (RB160), salicylic acid (SA), coumarin and phenol. The 6% Pb-CeO2 nanocubes shows better photocatalytic performance against anionic dyes especially for MB. To find the optimum condition for better photocatalytic performance of 6% Pb-CeO2 nanocubes, the photocatalytic process was conducted in different initial reaction conditions like reaction temperature, catalytic dosage, dye concentration and pH of the reaction solution. The stability and recyclability of 6% Pb-CeO2 photocatalyst was studied by XRD, FT-IR and EDS analysis after 5 cycles of MB degradation. The hydroxyl radical estimation and trapping experiments were conducted to observe the photocatalytic mechanism process in 6% Pb-CeO2 nanocubes. The perfect doping concentration for better organic pollutant degradation by Pb-CeO2 is found to be 6 mol% of Pb. Keywords: Cerium oxide, Oxygen vacancies, Anionic and cationic organic pollutant, Active species, Hydrothermal

Individual self-efficacy varies from person to person, especially by gender; previous research has shown that male students outperform female students in economics, science, computer, and math. There were inconsistencies between gender-affected self-efficacy, discipline, and motivation. Furthermore, a dearth of research was carried out in the Sri Lankan context. This study, therefore, examines the academic self-efficacy on the intrinsic motivation of first-year undergraduate management students at the Trincomalee Campus, Eastern University. The objectives of the research are to find out the influence of academic self-efficacy on intrinsic motivation and gender moderates the relationship between academic self-efficacy and intrinsic motivation of undergraduates. This is quantitative research. The conceptual variables are performance accomplishment, vicarious experience, verbal persuasion, physiological & emotional state, gender, and intrinsic motivation. Selected a hundred samples from the 2019/2020 academic year on the equal basis of sex and used the analytical methods are bivariate, independent sample T-test, and multivariate analysis. According to the study’s findings, gender plays a moderator between academic self-efficacy and intrinsic motivation. Furthermore, the independent T-test revealed that female students had a relatively greater influence than males on performance accomplishment, vicarious experience as well as physiological & emotional state. In the practical implication, previous research has examined the different disciplines of students' self-efficacy in different countries. This study particularly in the Sri Lankan context, and the contribution of undergraduate management students is novel.

This study aimed to synthesize silver nanoparticles (VJ@AgNPs) using Valeriana jatamansi root extract and assess their antibacterial, antioxidant, and antibiofilm properties against Escherichia coli, Staphylococcus aureus, and Streptococcus mutans. Various chemical and physical characterization methods were employed to analyze the synthesized VJ@AgNPs. UV-Visible spectroscopy confirmed the presence of VJ@AgNPs with a peak absorption at 426 nm, while FT-IR results indicated the involvement of phyto-compounds from V. jatamansi in the reduction and stabilization of these nanoparticles. High-resolution transmission electron microscopy revealed well-dispersed spherical nature with an average size of 29.1 ± 2.06 nm, and X-ray diffraction confirmed their crystalline structure. The biosynthesized VJ@AgNPs exhibited significant antibacterial activity against all tested pathogens, with substantial inhibition zones at 50 and 100 μg/mL concentrations. Additionally, VJ@AgNPs displayed potent antibiofilm activity and antioxidant capacity in scavenging assays. Furthermore, these VJ@AgNPs showed promise in photocatalytic degradation, effectively removing 95% of RhB dye within 75 minutes under solar light irradiation, following pseudo-first-order kinetics. This suggests their potential application in wastewater treatment for organic dye removal. The biocompatible and environmentally friendly nature of VJ@AgNPs underscores their potential as therapeutic agents against bacterial infections and oxidative stress-related diseases.

The structural flexibility of fluorophores and their ability to display different conformations provides an opportunity to develop fluorescent polymorphs that exhibit tunable solid-state fluorescence. In this study, a conformationally flexible organic fluorophore (4-(diphenylamino)benzaldehyde (TPA-CHO)) was crystallized from polar to non-polar solvents, and the solid-state fluorescence and structural assembly were explored. TPA-CHO, a typical donor–acceptor fluorophore, showed solvent polarity-dependent locally excited (LE) state blue fluorescence in toluene and charge transfer (CT) state greenish-yellow fluorescence in polar DMF. In contrast, crystals obtained from polar DMF exhibited strong blue fluorescence (LE state, λmax = 453 nm, φf = 2.54%), whereas crystals grown from hexane displayed greenish-yellow fluorescence (CT state) at 532 nm (φf = 7.68%) along with a weak emission at shorter wavelengths. Depending upon the solvent polarity, the crystals displayed dual fluorescence with varied LE and CT state fluorescence intensity between greenish-yellow (longer) and blue (shorter) wavelength emission. CIE chromaticity displayed fluorescence tuning from blue–greenish-yellow. Single-crystal structural analysis did not show any drastic change in the conformation or packing (polymorphism), and the same molecular packing was exhibited. However, a closer examination of the structure revealed subtle conformational differences dependent upon the solvent polarity. Although highest occupied molecular orbital (HOMO)–lowest unoccupied molecular orbital (LUMO) calculations showed a similar intramolecular charge transfer (ICT) from the diphenylamine donor to the benzaldehyde acceptor in all crystals, the optical band gap comparison revealed a clear difference between the crystals and supported subtle conformation-controlled tunable fluorescence. Thus, the present work provides insight into the solvent–solute interactions of conformationally flexible molecules for designing tunable fluorescent functional materials. [ABSTRACT FROM AUTHOR]

Online harassment is a serious problem that can have significant negative impacts on the mental health and well-being of its victims. To address this issue, an Android app has been developed that is accessible to a wide range of users worldwide. The app is built on a script backend process, providing a stable and efficient environment for data management and request processing. The app's API is integrated into the script backend process, ensuring seamless and efficient operation.During the installation process, the app requires users to go through a verification process that includes providing their Google Account, mobile number, and an OTP. This ensures that only legitimate users have access to the app's features and functions. The app also requires users to create a strong master password, which is directly connected to the Google bot, enhancing its security. Biometrics are recommended to protect the master password, ensuring that only authorized users can access their data.The app's security measures are crucial in ensuring the privacy and protection of user data. The use of biometrics and direct connection to the Google bot enhances security, and the app's API provides access to relevant information and enhances the user experience. Users can change their password securely, ensuring that only authorized users can access their data.Overall, the app is a reliable and efficient solution for managing and protecting user data. Its compatibility with a wide range of devices and seamless integration of API make it accessible to a large percentage of Android users worldwide. The app's verification process, use of biometrics, and direct connection to the Google bot enhance its security, ensuring that only authorized users have access to the app's functionalities. The development of this app is a critical step in addressing the issue of online harassment and protecting the privacy and well-being of its users.