Activity

The Ch-FeO/TiO2 showed a higher adsorption capacity of 33.1 mg/g compared to 29.8 mg/g of the unmodified chitosan (un-Ch) beads. This is due to the higher functional surface area of 27.13 m2/g, compared to that of 0.708 m2/g for un-Ch. We found a rapid adsorption rate of 240 min and the maximum adsorption capacity of 149.3 mg/g for Ch-FeO/TiO2. A large number of actives sites allows for increasing the naphthalene molecules interaction. Adsorption in seawater samples from Cartagena Bay (Colombia) exhibits an outstanding efficiency of up to 90%. These results suggest a promising, cheap, and environmentally friendly composite for remediation of water sources contaminated with complex compounds.In this research, the performance and emissions of a four-stroke spark ignition engine fuelled with varying proportion of propanol-camphor and gasoline blends were investigated. The physicochemical properties such as specific gravity, viscosity, fire point, flash point, and iodine value (I.V.) of the blends were determined, and the values obtained conform to the ASTM standard. Sample P0B (100% of pure gasoline and 5 g of camphor) had the best physicochemical property values higher than those of the least sample of P15B by the following percentages specific gravity (0.5%), viscosity (30.8%), fire point (5.08%), flash point (21.8%), and I.V. sample (0.5%). Linsitinib Also, the engine performance parameters such as brake power, brake thermal efficiency, brake mean effective pressure (BMEP), and specific fuel consumption were generated from the engine-measured parameters. Sample P0B has the best specific fuel consumption for the torque of 3 N m with a value of 22.77 kg/kW h, and sample P0A (100% of pure gasoline) has the best fuel consumption for a torque of 6 N m with a value of 12.52 kg/kW h. For brake thermal efficiency, sample P0B gives the best brake thermal efficiency at the two constant torques with a value of 0.36 for torque 3 N m and 0.67 for torque 6 N m. Sample P15C (85% of gasoline, 15% of propanol, and 5 g of camphor) gives the best BMEP at torque 3 N m with a value of 1.92 bar, and sample P5C (95% of gasoline, 5% of propanol, and 10 g of camphor) gives the best BMEP at 6 N m with a value of 3.85 bar. Exhaust emissions were analyzed for unburned hydrocarbon (HC), carbon monoxide (CO), carbon dioxide (CO2), and nitrogen oxide (NOx). The results showed that increasing the blending percentage reduces the emitted concentration of CO, HC, and NOx. Carbon monoxide emission was found to be lowest at sample P10A (90% of gasoline and 10% of propanol) for torque 3 N m with a value of 0.16, and at torque 6 N m, the sample with the lowest percentage was P15C with a percentage of 0.21.Field experience shows that extending shut-in periods are conducive to increasing tight oil production after fracturing operations. Understanding the regularity of pressure decay is helpful to establish an appropriate shut-in time. However, the characteristics and influencing factors of pressure decay are unclear. This paper studies the porosity, permeability, mineral composition, and pore structure of samples in six different blocks. The pressure decay regularity is tested according to an independently designed indoor shut-in experimental device, and the oil distribution of experimental samples is monitored using nuclear magnetic resonance technology. The results show that the fracturing fluid enters the matrix pores under the action of percolation to slowly drive out the oil, causing the well pressure to decay over time. There are three types of pressure decay characteristics concave type, fluctuation type, and quadratic type. Compared with conventional sandstone, the pressure decay rate of tight reservoirs is slower, and the pressure decay characteristics are more complicated. Clay mineral-rich reservoirs will swell when exposed to water. As a result, the strength of the framework will be weakened and collapsed. What’s more, it will cause blockage of the throat, blocking the flow of oil and the decay of pressure. In addition, the rate of pressure decay is also related to the volume of fracturing fluid, initial borehole pressure, and formation closure stress. At a certain proppant thickness (fracture width), the larger the fracturing fluid volume, the larger the fracture surface area and the faster the pressure decay rate; Moreover, the greater the initial shut-in pressure, the greater the pressure difference and the faster the decay rate; the formation closure stress causes the core porosity and the permeability to decrease, resulting in a decrease in the decay rate. The experimental results are of great significance for establishing a proper shut-in time and enhancing the oil recovery of tight reservoirs.The complex formation of actinium (Ac3+) and californium (Cf3+) ions with macropa (a promising ligand for medical applications, e.g., in targeted α therapy) has been studied by means of density functional theory (DFT) calculations. This work is focused on the structural and bonding properties, the latter on the basis of charge transfer data and topological properties of the electron density distribution. The effect of water solvent on the energetics has been investigated using the SMD model. A comparative analysis with the related properties of two representative lanthanide (La, Lu) complexes has been performed.Melt blending of homopolymers is an effective way to achieve an attractive combination of polymer properties. Dynamic vulcanization of fatty-acid-based polyester polyol with glycerol and poly(l-lactic acid) (PLLA) in the presence of hexamethylene diisocyanate (HDI) was performed with the aim of toughening PLLA. The dynamic vulcanization in an internal mixer led to the formation of a PLLA/PU biobased blend. Melt torque, Fourier transform infrared (FTIR), and gel fraction analysis demonstrated the successful formation of cross-linked polyurethane (PU) inside the PLLA matrix. Scanning electron microscopy (SEM) analysis showed that the PLLA/PU blends exhibit a sea-island morphology. Gel fraction analysis revealed that a rubbery phase was formed inside the PLLA matrix, which was insoluble in chloroform. FTIR analysis of the insoluble part shows the appearance of an absorption band centered at 1758 cm-1, related to the crystalline carbonyl vibration of the PLLA component, thus suggesting the partial involvement of PLLA chains in the cross-linking reaction.