Control of key technological and benchmark flows of polymer fluids poses a number of challenges. Some of them are nowadays under active investigation and rather far from complete understanding. This review considers such phenomena as both practically important and governed by fundamental laws of rheology and non-linear fluid mechanics. We observe, shear bands in polymeric and other complex structured fluids (like wormlike micellar solutions or soft glassy materials), birefrigerent strands, peculiarities of stress and pressure losses in fluids moving through complex shape domains. These and other processes involve inhomogeneity, instabilities and transient modes creeping in flow fields. In practical aspect this is of interest in such industrial process as polymer flooding for Enhanced Oil Recovery (EOR), where a flow inhomogeneity affects a polymer solution injectivity and residual oil saturation. The value of viscoelasticity in the polymer flooding is estimated. The observation is concluded by some new results on relation between polymer concentration in solutions and viscoelastic traits of benchmark flows.
The physical-mechanical characteristics of leather are crucial in the tanning industry since they determine whether the leather satisfies quality standards for various product manufacture. This study’s goal was to assess the physical-mechanical characteristics of leather that could be washed and used for garments after the Zetestan-GF polymer was added during the tanning process. The data gathered from the physical-mechanical analysis of two treatments—one a control with white leather (T1) and the other with leather treated with Zetestan-GF polymer (T2)—were compared for the development of this work. Each treatment was performed in triplicate, undergoing three washes, yielding a total of 24 samples for analysis. Following the acquisition of the leather, a control was applied and the various treatments were compared. SAS software version 9.0 was utilized for the data’s statistical analysis. The physical-mechanical properties of the control leather and the leather treated with Zetestan-GF polymer were compared using a one-way ANOVA, and any differences in the means (p < 0.05) were assessed using the Tukey test. The findings showed that while the polymer’s application during the tanning process affects the parameters of softness, tensile strength, elongation percentage, and dry and wet flexometry, it has no effect on the lastometry parameter. In conclusion, the physical-mechanical characteristics of the product made by tanning cow hides can be greatly impacted by the inclusion of a polymer.
The chemical reinforcement of sandy soils is usually carried out to improve their properties and meet specific engineering requirements. Nevertheless, conventional reinforcement agents are often expensive; the process is energy-intensive and causes serious environmental issues. Therefore, developing a cost-effective, room-temperature-based method that uses recyclable chemicals is necessary. In the current study, poly (styrene-co-methyl methacrylate) (PS-PMMA) is used as a stabilizer to reinforce sandy soil. The copolymer-reinforced sand samples were prepared using the one-step bulk polymerization method at room temperature. The mechanical strength of the copolymer-reinforced sand samples depends on the ratio of the PS-PMMA copolymer to the sand. The higher the copolymer-to-sand ratio, the higher the sample’s compressive strength. The sand (70 wt.%)-PS-PMMA (30 wt.%) sample exhibited the highest compressive strength of 1900 psi. The copolymer matrix enwraps the sand particles to form a stable structure with high compressive strengths.
Subcutaneous (SC) drug delivery is one of the best routes of drug administration to patients over intravenous (IV) administration due to the ease of application and patient acceptance. The main limitation of using the SC route is administering larger volumes of drug, greater than 3–5 mL for therapeutic dosages. Wearable injectors on body devices are an attractive option for larger-volume drug delivery to patients. Thus, the need for a self-administration strategy at home is growing faster and is required for the next level of time-dependent and high-volume drug delivery. The advances in low-cost, connected on-body delivery systems hold great opportunity for novel ways of delivering home-based drug therapy in the future.
Heat removal has become an increasingly crucial issue for microelectronic chips due to increasingly high speed and high performance. One solution is to increase the thermal conductivity of the corresponding dielectrics. However, traditional approach to adding solid heat conductive nanoparticles to polymer dielectrics led to a significant weight increase. Here we propose a dielectric polymer filled with heat conductive hollow nanoparticles to mitigate the weight gain. Our mesoscale simulation of heat conduction through this dielectric polymer composite microstructure using the phase-field spectral iterative perturbation method demonstrates the simultaneous achievement of enhanced effective thermal conductivity and the low density. It is shown that additional heat conductivity enhancement can be achieved by wrapping the hollow nanoparticles with graphene layers. The underlying mesoscale mechanism of such a microstructure design and the quantitative effect of interfacial thermal resistance will be discussed. This work is expected to stimulate future efforts to develop light-weight thermal conductive polymer nanocomposites.
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