Islamiah College

Industrial robotics cells in battery manufacturing must sustain high throughput without compromising safety under distribution shift and rare failures, yet most digital twins remain data-only, deliver uncalibrated Remaining Useful Life (RUL), or lack runtime safety mechanisms for action. To address these important limitations, we develop a Physics-Informed Bayesian Digital Twin (PI-BDT) that operationalizes a robotics-integrated prognostics-to-control pipeline. Physics-informed networks encode wear/thermal dynamics for robot-impacted stations (e.g., winding cell and calendering/oven interactions) and produce survival-based RUL with decomposed aleatoric/epistemic uncertainty via Bayesian ensembles. A shift-aware calibration loop (drift detection, uncertainty inflation, conformal quantiles) preserves nominal coverage. These distributions drive a conservative-quantile safety layer that enforces an operational risk budget (chance-constraint check) and issues explainable continue/derate/abort commands through an MPC-guided Soft Actor-Critic policy, deployable at the edge with millisecond-level latency and standard shop-floor integration (PLC/MES/ROS). On 200 pilot run-to-failure trajectories plus 500 simulated edge cases, PI-BDT achieves RUL RMSE 9.9 h, MAE 8.0 h, PICP 0.93 (95% intervals) and improves unplanned downtime by 35.2%, OEE by 22.2%, and maintenance cost by 27.4% versus a threshold baseline. The novelty is an auditable, robotics-integrated twin that maps calibrated, physics-consistent RUL to safety-constrained actions robust to shift and rare events, advancing trustworthy, computer-integrated maintenance for robotized production lines.

A series of new Donor-Acceptor-based compounds was designed and synthesized with triphenylamine as the electron-donating unit, and 2-phenylbenzothiazole functionalized with 4-nitrophenyl, 4-cyanophenyl, 4-formylphenyl, and 4-trifluoromethylphenyl as acceptors. The photophysical studies reveal efficient intramolecular charge transfer, and the electrochemical analysis indicated irreversible oxidation with relatively lower optical band gaps ranging from 3.09 to 3.15 eV, supporting the compound's potential for effective charge transport. Thin-film morphology studies showed uniform surface coverage and high crystallinity, suggesting well-ordered molecular packing conducive to enhanced charge transport. All synthesized compounds were integrated into memory device architectures, exhibiting non-volatile binary Write-Once-Read-Many (WORM) behavior. The devices demonstrated excellent performance, with data retention stability exceeding 103 s and an endurance capability of up to 100 programming cycles. Among the synthesized compounds, the compound containing the 4formylphenyl group displayed the lowest switching threshold voltage and an ON/OFF current ratio of 103, while the nitro-substituted compound showed the highest ON/OFF ratio of 104, attributed to the strong electronwithdrawing nature of the nitro group. Computational studies supported the experimental findings, indicating that the memory-switching mechanism arises from a synergistic interaction of charge transfer and charge trapping processes.

The donor-acceptor system is vital, with benzimidazole emerging as a notable acceptor for memory devices. In this work, a new benzimidazole-linked benzothiophene was synthesized via Pd-catalyzed Suzuki cross-coupling, featuring D-A-D and D-A-A compounds. UV-vis analysis indicated strong intramolecular interactions and a band gap of 3.12-3.25 eV, suggesting advantageous charge transport properties for memory applications. SEM and thin-film XRD confirmed improved molecular ordering, substrate coverage, and high crystallinity in the thin films. Non-volatile binary WORM memory behavior was exhibited by the synthesized compounds. The methoxy-substituted compound showed effective memory performance with a low threshold voltage (-1.08 V) and an ON/OFF ratio of 103, while the dibenzofuran-substituted compound exhibited a higher ON/OFF ratio of 104 and a threshold voltage of -2.62 V. D-A-based compounds with varying substituents demonstrated favorable retention time (103 s) and endurance up to 100 cycles. The observed resistive switching mechanism results from both charge trapping and charge transfer effects. This study underscores the significant impact of substituent alterations in D-A molecules on molecular arrangement, electron trap depth, and thin film morphology, and all of which significantly influence memory performance in organic devices.

Introduction: Fungal infections are associated with morbidity and mortality globally and immense economic burden. With the emergence of multidrug resistant fungal strains, it is essential to develop new antifungal drugs. Aim: To synthesize and evaluate the antifungal activity of N-(3- (4-(1,3-dioxolan-2-yl) phenyl)-1,2,4-thiadiazol-5-yl) benzamides against Candida albicans, Cryptococcus neoformans and Aspergillus niger. Materials and Methods: An in-vitro study was conducted in the Department of Chemistry, Islamiah College, Vaniyambadi, Tamil Nadu, India from August 2022 to February 2024. Novel N-(3-(4-(1,3-dioxolan-2-yl) phenyl)-1,2,4-thiadiazol-5-yl) benzamides were synthesized by a simple procedure. Pyridine was added to 3-(4-(1,3-dioxolan-2yl) phenyl)-1,2,4-thiadiazol-5- amine and dichloromethane was added dropwise. The resulting mixture was washed with water, saturated brine solution, dried over anhydrous sodium sulfate and concentrated under reduced pressure. The purification of crude residue was done by column chromatography. Their characteristics were confirmed by 1H and 13C Nuclear Magnetic Resonance (NMR) and Liquid Chromatography- Mass Spectrometry (LC-MS). They were screened for activity against Candida albicans, Cryptococcus neoformans and Aspergillus niger by disc diffusion method. A loopful of cells from fungal stock cultures was added to Sabouraud Dextrose Broth (SDB) containing test tubes and incubated at 25°C for 24 hours. The experiments were conducted with the test compounds and control experiment was done with Fluconazole. The growth inhibition zones around the disks were measured in mm at 28°C after 2-3 days. Results: Twelve N-(3-(4-(1,3-dioxolan-2-yl) phenyl)-1,2,4- thiadiazol-5-yl) benzamides (7a-7l) were synthesized with good yield. Compounds 7c and 7g had good activity against Candida albicans. Compounds 7f and 7g had moderate activity against Aspergillus niger, whereas Compounds 7d, 7f and 7h had moderate activity against Cryptococcus neoformans. Conclusion: A series of N-(3-(4-(1,3-dioxolan-2-yl) phenyl)- 1,2,4-thiadiazol-5-yl) benzamides (7a-7l) were synthesized. These compounds have moderate to good antifungal activity against Candida albicans, and moderate activity against Aspergillus niger and Cryptococcus neoformans.

A series of novel donor-bridge-acceptor (D-π-A) organic small molecules featuring pyridine-functionalized cores was designed, synthesized, and systematically investigated for application in nonvolatile resistive switching memory devices. The molecular framework was tailored via Pd-catalyzed Suzuki cross-coupling and Wittig-Horner condensation to integrate diverse electron-donating and electron-withdrawing functionalities. The molecular architecture integrated electron-rich units, such as tert-butylphenyl, methoxyphenyl, and dibenzofuran, with strong acceptors, such as cyano and nitroaryl groups, enable fine-tuning of electronic properties through structural asymmetry. Photophysical studies confirmed strong intramolecular charge transfer (ICT), and electrochemical analysis revealed narrow optical bandgaps of 3.10-3.20 eV. All materials exhibited stable binary memory behavior, with ON/OFF current ratios and retention times exceeding 103 s. Notably, the dibenzofuran-nitrophenyl derivative exhibited superior performance, with a low threshold voltage of -1.11 V and an ON/OFF ratio of 105. Density functional theory (DFT) and electrostatic potential analyses supported a charge transfer-assisted, charge trapping-enabled resistive-switching mechanism. Thin-film morphology and GI-XRD studies further indicated uniform film coverage and crystalline ordering. The tunable donor-acceptor substitution strategy provides valuable insights into molecular design principles for solution-processable, high-performance organic memory devices.