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Two-dimensional models of die-melt and die-gas-melt were created using Polyflow software. The radial and axial directions flow rate, shear rate, pressure, and first normal stress of the specimen were numerically simulated under conventional extrusion and gas-assisted extrusion while taking into consideration the heat transfer on the free surface of the specimen. The crystallinity was determined by combining the simulation data with the crystallization kinetics equation. The computation results are then examined using Origin software. The findings demonstrate that the use of gas-assisted extrusion technology can cause the Vx to decrease or even turn negative by reducing the friction between the melting edge and the die wall. Additionally, it makes Vy , pressure, shear rate, temperature, first normal stress, and crystallinity increasingly steady and aids in reducing or avoiding the Barus effect. The crystallization phenomena can be measured by using the crystallization kinetics equation. The study of extruded parts at the microscopic level will benefit from this application.

Based on the time-temperature equivalence principle, the relationship between the melt relaxation time (MRT) and melt heating temperature (MHT) in an improved gas-assisted extrusion (GAE) of a polypropylene (PP) sheet was investigated by numerical simulations. In the simulations, the MRT was varied and the inherent properties of the MHT were controlled using experimental methods. With an increase in MRT, the velocity in all directions, pressure drop, and shear rate of the melt increased; however, increasing the MRT does not always yield a positive effect on the GAE process of the melt. For instance, the melt velocity increased vertically at the die exit with MRT, resulting in an outward extrudate swell. In addition, the extruded product was intact when the melt was heated to 220[degrees] C, which verified the principle of time-temperature equivalence. KEYWORDS gas-assisted extrusion, heating temperature, plastic sheets, relaxation time, timetemperature equivalence principle, 1 | INTRODUCTION In conventional plastic sheet extrusion, the high viscoelasticity of polymers makes them susceptible to undesirable extrudate swell [1-3] and tensile deformation, [4-9] and the internal stress in [...]

The confinement and high utilization of sulfur in the cathodes is critical for improved cycling performance of lithium‐sulfur batteries. In this case one‐pot hydrothermal strategy is developed to produce rGO/MXene/sulfur composite aerogels where sulfur is in situ trapped in the 3D rGO/MXene conductive skeleton. The optimized composite aerogels as free‐standing cathodes delivery a specific capacity of 951 mAhg−1 after 100 cycles at 0.2 C with a low fading rate of 0.062 % per cycle. The excellent cycling performance is correlated with highly oxidized MXene and in situ formed sulfate/thiosulfate complex layer in the long‐term cycles. [ABSTRACT FROM AUTHOR]

Gas-assisted sheet extrusion is a promising and environment-friendly method used in polymer processing. Insufficient gas intake due to the adherence of the polymer melt to the inlet gap is a disadvantage of the method. Therefore, in this study an improved die assembly with parallel gas intake was designed. As the melt is prone to falling at the die exit during the horizontal extrusion process, different thickness settings are used for the up and down gas layers (0.25 and 0.75 mm, respectively) to avoid this. For the improved die assembly, the gas inlet pressure may be varied systematically to study the mechanism of stable sheet extrusion. When the gas inlet pressure is 0.1 MPa, the melt can be extruded smoothly, and the extruded sheet surface is transparent and flat. However, when the optimum pressure is exceeded, the extruded sheet becomes twisted or even broken. KEYWORDS down gas layer, gas inlet pressure, gas-assisted extrusion (GAE), improved die assembly, numerical simulation, 1 | INTRODUCTION Plastic sheets are used extensively in the production of thermoforming products, packaging products, circuit board partitions, handicrafts, and other industries. [1-5] However, owing to the viscoelasticity [6-8] [...]

Verbal memory decline is a significant concern following temporal lobe surgeries in patients with epilepsy, emphasizing the need for precision presurgical verbal memory mapping to optimize functional outcomes. However, the inter‐individual variability in functional networks and brain function‐structural dissociations pose challenges when relying solely on group‐level atlases or anatomical landmarks for surgical guidance. Here, we aimed to develop and validate a personalized functional mapping technique for verbal memory using precision resting‐state functional MRI (rs‐fMRI) and neurosurgery. A total of 38 patients with refractory epilepsy scheduled for surgical interventions were enrolled and 28 patients were analyzed in the study. Baseline 30‐min rs‐fMRI scanning, verbal memory and language assessments were collected for each patient before surgery. Personalized verbal memory networks (PVMN) were delineated based on preoperative rs‐fMRI data for each patient. The accuracy of PVMN was assessed by comparing post‐operative functional impairments and the overlapping extent between PVMN and surgical lesions. A total of 14 out of 28 patients experienced clinically meaningful declines in verbal memory after surgery. The personalized network and the group‐level atlas exhibited 100% and 75.0% accuracy in predicting postoperative verbal memory declines, respectively. Moreover, six patients with extra‐temporal lesions that overlapped with PVMN showed selective impairments in verbal memory. Furthermore, the lesioned ratio of the personalized network rather than the group‐level atlas was significantly correlated with postoperative declines in verbal memory (personalized networks: r = −0.39, p =.038; group‐level atlas: r = −0.19, p =.332). In conclusion, our personalized functional mapping technique, using precision rs‐fMRI, offers valuable insights into individual variability in the verbal memory network and holds promise in precision verbal memory network mapping in individuals. [ABSTRACT FROM AUTHOR]

Experimental study on the shrinkage of short fiber-reinforced polymer injection molding products during the overflow water-assisted injection molding (OWAIM) process, and and analysis of the influence of process parameters with the computer-aided engineering (CAE) were performed. The investigation shows that the shrinkage of the product increases linearly along the melt flow with the increase of water injection pressure. The shrinkage of products is on the rise with the increase of water injection pressure, melt temperature, and mold temperature, but it is decreasing with the increase of flow delay time and fiber mass content. Based on the Taguchi orthogonal array design, an experiment study was conducted to characterize the effect of processing parameters on the shrinkage of OWAIM pipe. The results show that decreasing the mold temperature and increasing the fiber mass content can effectively reduce the shrinkage and warpage of products, thus improving the product quality.