Direct additive fabrication of biomedical dental devices is an effective and cost-efficient alternative process to the conventional manufacturing process. Still, due to the disorganized mesh topology and poor scan quality conditions, the geometric fidelity and slicing consistency of CAD models obtained through 3D scanning is frequently impaired. This study is strategic in its approach to enhance the accuracy of CAD analysis through the assessment of the effects of environmental as well as operator-specific scanning parameters. Design of Experiments (DoE) framework Response Surface Methodology (RSM) is used to give the best combinations of the parameters and hence do away with tedious manual experiments. The reconstructed CAD geometries are compared to reference models in order to measure the deviations. A hybrid predictive model of RSM and Artificial Neural Networks (ANN) is adopted that are then optimized to finesse with machine learning based on prescribed constraints. Comparative appraisals identify the best modelling method amongst the alternatives that are tested. Even though the scanning processes are manually performed, close control will reduce the variability introduced by the operator, which is considered a limitation of the study. Also, mesh refinement of optimized CAD results is performed to eliminate duplicate vertices and analyse structural regularity and fabrication precision. The analysis demonstrates the high interdependence between scan conditions and model accuracy that provides useful insights to optimize scanning processes under limited working conditions like human–robot collaborative environment.
Nanoparticles (NPs) are small-sized particles that have various applications; however, these metallic particles are found to be toxic against aquatic organisms. Therefore, the current study observed the toxicity of silver nanoparticles (AgNPs) and iron oxide nanoparticles (IONPs) using Ctenopharyngodon idella by swimming behavior, bioaccumulation, histopathological alterations, and oxidative stress. Fish were exposed to AgNPs and IONPs (5.16 mg/L) for 10 days to assess their possible effects on behavioral and physiological changes. Results showed that both NPs significantly decreased the critical swimming speed (Ucrit), and found a significant correlation between body size and swimming speed. The NPs were significantly accumulated in the intestine, followed by muscles, gills, liver, and brain (p < 0.05), which resulted in histological alterations, i.e., necrosis in gill lamella and grey matter disruption in brain. In addition, the NPs resulted in oxidative stress, i.e., the superoxide dismutase enzyme in the gill was significantly increased (291.66 ± 4.04) in the IONPs group. The possible mechanisms include NP-induced gill damage and altered gill morphology, which may impair respiratory efficiency, ROS, and osmoregulation, leading to reduced swimming performance.
Lignocellulosic biomass (LCB) is an abundant, low-cost feedstock, but its conversion is limited by structural recalcitrance and cost-intensive unit operations, especially downstream processing. This review examines rhamnolipids as both products of LCB valorization and process additives that improve LCB deconstruction. It highlights the native microbial production of rhamnolipids from diverse LCB-derived streams and the associated titer, rate and yield limits. Special emphasis is placed on different metabolic engineering strategies to increase the complete utilization of lignocellulosic derived carbon and highlights its dual role in pretreatment/saccharification and fermentation, including enzyme protection from non-specific lignin binding, inhibitor mitigation, and gains in sugar and ethanol yields. Further, the techno-economic constraints related to feedstock quality and cost, fermentation productivity, and other the dominant factors that can lower the overall cost and enhance productivity. The review marks rhamnolipid amongst the top ranked biosurfactant and underscores the factors that can prove to be game changer for upcoming biorefineries.
Aluminum-boron carbide (Al-B4C) composites have shown promise as lightweight, wear-resistant materials; however, weak particle-matrix bonding, melt-stage clustering, and unstable friction have limited reliability. Addressing these linked defects is essential for high-strength components. Prior work did not vary the interface design, dispersion, and solid lubrication simultaneously within a single process history, leaving the synergy untested. This study aimed to determine whether engineered interphases produced by ultrasonic dispersion and trace 2D lubricants increased the tensile strength and stabilised sliding wear. A balanced factorial crossed interphase route (electroless Ni-P, sol-gel TiO2 -> TiC, in situ Ti/B), ultrasonication on/off, and graphene or hBN at 0-1.0 wt. %; XRD/EDS, interphase-thickness and dispersion statistics, and quantitative masks for pull-out and tribofilms supported the analysis. Tensile and pin-on-disk tests yielded wear, friction, and UTS. Graphene-bearing hybrids with Ni-P or in-situ Ti/B maintained UTS >= 330 MPa and reduced wear to <= 0.2 mm3 & centerdot;m-1 with steady friction near 0.20; transfer films reached 65-80% coverage and 95-105 nm median thickness. Ultrasonics sharpened the TiC interfacial coherence and reduced particle pull-out. The results indicated that metallurgical or ceramic interphases paired with graphene produced a low-wear, high energy efficiency on the strength-wear map and surpassed states.
An efficient protocol has been developed for the synthesis of highly functionalized pyrano [2,3-c]pyrazole derivatives using ethyl acetoacetate, hydrazine hydrate, malononitrile, and various arylaldehydes, in the presence of a catalytic amount of DBN in ethanol-water, affording 85%-95% yields. The developed cascade method offers several advantages, including high yield, the use of metal-free catalysts, mild reaction conditions, and a simple work-up process, all of which are consistent with the principles of green chemistry. The synthesized compounds were further evaluated for their antioxidant activity.
