Suspensions of motile cells are model systems for understanding the unique mechanical properties of living materials which often consist of ensembles of self-propelled particles. We present here a quantitative comparison of theory against experiment for the rheology of such suspensions in extensional flows. The influence of motility on viscosities of cell suspensions is studied using a novel acoustically-driven microfluidic capillary-breakup extensional rheometer. Motility increases the extensional viscosity of suspensions of algal pullers, but decreases it in the case of bacterial or sperm pushers. A recent model [Saintillan, Phys. Rev. E: Stat., Nonlinear, Soft Matter Phys., 2010, 81, 56307] for dilute active suspensions is extended to obtain predictions for higher concentrations, after independently obtaining parameters such as swimming speeds and diffusivities. We show that details of body and flagellar shape can significantly determine macroscale rheological behaviour.
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http://dx.doi.org/10.1039/c4sm02742f | DOI Listing |
Polymers (Basel)
December 2024
Key Laboratory for Enhanced Oil & Gas Recovery of the Ministry of Education, Northeast Petroleum University, Daqing 163318, China.
In the process of oilfield development, the surfactant-polymer (SP) composite system has shown significant effects in enhancing oil recovery (EOR) due to its excellent interfacial activity and viscoelastic properties. However, with the continuous increase in the volume of composite flooding injection, a decline in injection-production capacity (I/P capacity) has been observed. Through the observation of frozen core slices, it was found that during the secondary composite flooding (SCF) process, a large amount of residual oil in the form of intergranular adsorption remained in the core pores.
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December 2024
Faculty of Food Engineering, Stefan cel Mare University of Suceava, 720229 Suceava, Romania.
Wine lees, the second most significant by-product of winemaking after grape pomace, have received relatively little attention regarding their potential for valorization. Despite their rich content in bioactive components such as β-glucans, industrial utilization faces challenges, particularly due to variability in their composition. This inconsistency impacts the reliability and standardization of final products, limiting broader adoption in industrial applications.
View Article and Find Full Text PDFInt J Biol Macromol
December 2024
Department of Petroleum Engineering, School of Energy Technology, Pandit Deendayal Energy University, Gandhinagar, Gujarat 382426, India. Electronic address:
Naturally occurring gas clathrates are a significant methane resource-the primary component of natural gas, regarded as the cleanest hydrocarbon and a key feedstock for producing gray and blue hydrogen. Despite the global abundance of gas hydrate reserves, extraction via depressurization has yet to achieve commercially viable production rates. The primary limitation lies in the low permeability of hydrate-bearing sediments, where solid clathrates obstruct porous pathways, hindering dissociation and slowing gas recovery.
View Article and Find Full Text PDFGels
December 2024
College of Food Science and Technology, Huazhong Agricultural University, Wuhan 430070, China.
In the oil dispersion of chitosan, the formation of a capillary bridge was triggered by adding a small amount of water to obtain an oleogel. With this method, the types of liquid oil and the ratio of oil/chitosan/water were explored to achieve an optimal oleogel. MCT performed best, followed by soybean oil, which was chosen for its edibility and cost.
View Article and Find Full Text PDFEur J Pharm Sci
December 2024
Department of Pharmaceutical Technology, Faculty of Pharmacy, Medical University of Gdansk, Hallera av. 107, Gdansk 80-402, Poland.
Adhesiveness of dermal patches can be modified in the presence of active substances. The effect is more complex when liquid components are also present in the matrix. Commercial grade pressure sensitive adhesive (PSA) polyacrylates (three types) and silicones (two types) were used to prepare adhesive matrices and liquid additives were propylene glycol, polyoxyethylene glycol, isopropyl myristate, triacetin, triethyl citrate or low viscosity silicone oil.
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