The results showed that okra’s size is between 150–900 μm. The core flooding was challenged by the low porosity and permeability of the core. A rheology study was conducted under different shear rates for three plausible concentrations: 1 wt.%, 2 wt.% and 5 wt.%. SEM and FTIR were used to characterize morphology and chemical composition. The evaluation targets the heavy oil trapped in carbonate reservoirs. The current study examines okra’s (natural polymer) efficiency for polymer flooding, particularly in Kazakhstan. However, natural polymer studies are still preliminary. Natural polymers have been investigated as part of the endeavors of green chemistry practice in the oil field.
Open office apa format template pro#
In consideration of the important role of M pro in developing antivirals against coronaviruses, insights derived from this study should add to the design of pan-coronaviral M pro inhibitors that are safer and more effective. A detailed analysis of these crystal structures defined the key molecular determinants required for inhibition and illustrate the binding mode of M pros from other coronaviruses. Crystal structures of M pros from SARS-CoV-2, SARS-CoV, and MERS-CoV bound to the inhibitor YH-53 revealed a unique ligand-binding site, which provides new insights into the mechanism of inhibition of viral replication. Here, we showed that a peptidomimetic compound with benzothiazolyl ketone as warhead, YH-53, is an effective inhibitor of SARS-CoV-2, SARS-CoV, and MERS-CoV M pros. Inhibitors that target the main protease (M pro) of SARS-CoV-2, an essential enzyme that promotes viral maturation, represent a key class of antivirals. Although many vaccines protecting against SARS-CoV-2 are currently available, constantly emerging new variants necessitate the development of alternative strategies for prevention and treatment of COVID-19. The ongoing spread of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has caused hundreds of millions of cases and millions of victims worldwide with serious consequences to global health and economies. The proposed model provides guidance for the control of residual stress in the precision machining of complex thin-walled structures. The results show that the influence of machining parameters on surface residual stress is nonlinear. The effects of the inclination angle, cutting speed, and feed rate on the surface residual stress are investigated.
Open office apa format template verification#
The verification shows that the average prediction error rate is 14.4% in the σ x direction and 17.2% in the σ y direction. A good correlation is observed between the experimental and the predicted results. Then, the RBF neural network is introduced to relate the machining parameters with the surface residual stress using simulated and experimental samples. These results are found to be in good agreement with average absolute errors of 11.6% and 15.2% in the σ x and σ y directions, respectively. Firstly, a 3D numerical model is established and verified through a cutting experiment. A radial basis function (RBF) neural network model based on simulated and experimental data is developed to predict the surface residual stress for multi-axis milling of Ti-6Al-4V titanium alloy. To optimize the state of residual stress, the relationship between the surface residual stress and the machining conditions is studied in this work. Larger compressive or smaller tensile residual stress is more prone to causing fatigue cracks. The analytical and experimental results demonstrate that an increase in the first end-stop angle and the main-stage hysteresis or a decrease in the second end-stop angle and the main-stage stiffness of the clutch can effectively suppress driveline torsional vibration during vehicle accelerating.Īs one essential indicator of surface integrity, residual stress has an important influence on the fatigue performance of aero engines’ thin-walled parts. In order to validate the proposed model and the analytical results, an optimized clutch is designed and the experiments of torsional vibration are conducted with the prototype and the optimized clutch. Based on the proposed model, the influences of the clutch parameters on driveline torsional vibration are investigated. Taking a commercial vehicle as an example, the dynamic behaviors and inherent characteristics of the driveline system are calculated and analyzed. A generic automobile powertrain model with 7 degrees of freedom is proposed considering the transient engine torque, the nonlinear characteristics of multi-stage clutch and tire slip. This study investigates the influence of clutch nonlinear behaviors on the torsional vibration of the driveline with numerical and experimental methods. Torsional vibration of the automotive driveline has significant influence on driving comfort.