Experimental validation of computational fluid dynamics modeling for narrow tillage tool draft

Energy requirement of a tillage tool, mostly represented by tool draft, is a function of different soil–tool interaction components like soil parameters, tool parameters and system parameters. Soil–tool interaction modeling was conducted using computational fluid dynamics (CFD) approach considering soil as a Bingham material. Soil bin tests were conducted to validate tool draft predictions obtained from this numerical modeling. Numerical predictions and soil bin experiments for the tool draft were observed with 40 mm wide vertical tool operating at four different depths of 40, 80, 120, and 160 mm. The tool was operated at four different operating speeds of 1, 8, 16 and 24 km h⁻¹ in clay loam soil with two moisture contents of 14% and 20%. Thus, the experimental design consisted in a (2 × 4 × 4) complete randomized factorial with two replications for each test. Simulation results over-predicted tool draft in comparison to the experimental values. The difference between the predicted and measured draft were not consistent and ranged from 1% to 42%, with an average of 24% and 22% for moisture contents of 14% and 20%, respectively. The agreement of simulation data with experimental values was higher at shallow depth of operation and lower tool operating speed. The correlation coefficient between the simulation and experimental draft were found to vary from 0.9275 to 0.9914.     

Nanohybrid Comprising Gold Nanoparticles – MoS2 Nanosheets for Electrochemical Sensing of Folic Acid in Serum Samples

Folic acid (FA) deficiency is associated with several clinical conditions such as megaloblastic anemia, neuropsychiatric, and pregnancy-related syndromes, this makes FA an important metabolite to be monitored. We have fabricated an electrochemical biosensor based on gold nanoparticles decorated molybdenum disulfide nanosheets (AuNPs−MoS₂NSs) nanocomposite as a transducer matrix for specific and rapid electrochemical detection of FA. Differential pulse voltammetry (DPV) studies displayed a rapid analytical response of the fabricated AuNPs−MoS₂NSs/GCE sensor probe towards FA in a wide concentration range of 0.001–100 μM with a very low detection limit of 0.72±0.03 nM. The selectivity of the fabricated sensor probe has been examined in the presence of interferents such as dopamine, uric acid, ascorbic acid, glucose, and urea. The clinical potential of the fabricated biosensor was established by monitoring FA in human serum samples. The developed AuNPs−MoS₂NSs/GCE sensor probe showed high reproducibility and stability, indicating its promise for FA detection in clinical settings.     

g-B3C2N3: A Potential Two Dimensional Metal-free Photocatalyst for Overall Water Splitting**

Based on hybrid density functional theory (DFT) calculations, we propose a new two-dimensional (2D) B-C-N material, graphitic- (g- ), with the promising prospect of metal-free photocatalysis. We find it to be a near ultraviolet (UV) absorbing direct band gap (3.69 eV) semiconductor with robust dynamical and mechanical stability. Estimating the band positions with respect to water oxidation and hydrogen reduction potential levels along with a detailed analysis of reaction mechanism of hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), we observe that g- monolayer can be efficiently used for hydrogen fuel generation over entire pH range as well as for spontaneous water splitting at basic pH range. Upon biaxial strain application, band positions get realigned along with the free energy change that is involved in HER and OER. Consequently, operational range of pH for OER gets broadened and the proposed material exhibits the ability to perform spontaneous and simultaneous oxidation and reduction even in neutral pH. The combination of pH variation and applied strain can be used as a key to control the reducing and/or oxidizing abilities precisely for diverse photocatalytic reactions to attain environmental sustainability.     

UV-to-NIR Harvesting Conjugated Porous Polymer Nanocomposite: Upconversion and Plasmon Expedited Thioether Photooxidation

Photocatalysts capable of harvesting a broad range of the solar spectrum are essential for sustainable chemical transformations and environmental remediation. Herein, we have integrated NIR-absorbing upconversion nanoparticles (UCNP) with UV-Vis absorbing conjugated porous organic polymer (POP) through the in situ multicomponent C−C coupling to fabricate a UC−POP nanocomposite. The light-harvesting ability of UC−POP is further augmented by loading plasmonic gold nanoparticles (AuNP) into UC−POP. A three-times enhancement in the upconversion luminescence is observed upon the incorporation of AuNP in UC−POP, subsequently boosting the photocatalytic activity of UC−POP−Au. The spectroscopic and photoelectrochemical investigations infer the enhanced photocatalytic oxidation of thioethers, including mustard gas simulant by UC−POP−Au compared to POP and UC−POP due to the facile electron-hole pair generation, suppressed exciton recombination, and efficient charge carrier migration. Thus, the unique design strategy of combining plasmonic and upconversion nanoparticles with a conjugated porous organic polymer opens up new vistas towards artificial light harvesting.