In this article, we discuss the effect of the bounding cylinder on the rheology of a dilute suspension. We consider a colloidal solution of spherical particles flowing through a cylinder under creeping motion assumption. For transport of such particulate fluid, the increase in the viscous loss due to the existence of suspended particles can be described in terms of enhanced effective viscosity eta(eff) for the medium. Einstein's formula quantifies this increase in viscosity when the flow-domain is unbounded. For bounded domain, however, the increase in viscosity is not only dictated by the properties of the solutes but also affected by the geometry of the confinement. We illustrate this effect of geometry on the effective viscosity by accurately resolving the viscous interaction between a freely suspended sphere and a confining cylinder. First, we take into account a solution of equal spheres, and present the effective viscosity for different cylinder to sphere size ratio as well as for different excluded volume near the cylinder periphery for electrostatic interactions. Then, we also consider a variation in size distribution and determine the rheological properties for different means and variances of the distribution.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1063/1.3315867 | DOI Listing |
Sci Rep
January 2025
Department of Physical Chemistry, University of Cádiz, 11510, Puerto Real, Spain.
To reduce greenhouse emissions and producing electricity with the smallest environmental impact, developing solar power technology is one of the most important milestones to achieve. Thus, to improve the efficiency of the concentrated solar power (CSP) plants, with lower environmental impact, is of great interest. This work reports the development of nanofluids, a colloidal suspension of nanomaterials in a fluid, based on an environment-friendly base fluid for improving the performance of the heat transfer process in CSP plants.
View Article and Find Full Text PDFInt J Biol Macromol
January 2025
CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai 200032, China.
Microbubble-assisted starch modification (MASM) using different gases (N, CO and air) was employed to assess the effects of hydrodynamic cavitation (HC) on various botanical starches, including potato, wheat, corn and rice. SEM showed that N- and CO- microbubbles created more pronounced holes and cracks on the starch surfaces than air-microbubbles. The hydrodynamic cavitation-assisted microbubble (HCAM) treatment significantly reduced the amorphous and crystalline structures in potato and wheat starches, with less impact observed in corn and rice.
View Article and Find Full Text PDFPLoS One
January 2025
Chemical & Petroleum Engineering Department, United Arab Emirates University, Al Ain, United Arab Emirates.
Oil fields located in cold environments and deep-sea locations often face challenges with paraffin wax buildup in pipelines during long-distance crude oil transportation. Various strategies have been employed to address this issue, with chemical methods being the most effective and economical. However, traditional chemical inhibitors present problems due to their high toxicity and low biodegradability, leading to increased operational costs and environmental concerns.
View Article and Find Full Text PDFAsian Pac J Cancer Prev
January 2025
Department of Rural Clinical Science, La Trobe Rural Health School, La Trobe University, Melbourne, Australia.
Objective: To compare the salivary profiles of smokers (e-cigarette smokers, e-cigarette and former conventional cigarette smokers, dual users, and conventional cigarette smokers) and non-smokers in adolescents, focusing on acidity level, flow rate, viscosity, as well as the quantity of Streptococcus mutans, Porphyromonas gingivalis, and Candida albicans.
Methods: This analytical observational study, with a cross-sectional design, involves collecting saliva samples from five groups through the draining method. Saliva viscosity was assessed visually, while saliva flow rate was monitored over a ten-minute period.
Plant Foods Hum Nutr
January 2025
Instituto de Ciencia y Tecnología de Alimentos Córdoba (ICYTAC) - CONICET-UNC, Av. Juan Filloy S/N, Ciudad Universitaria, Córdoba, Argentina.
The focus of this work was to evaluate the differences between the thermal and mechanical effects generated by ultrasound waves on the properties of corn starch, which facilitate the subsequent enzymatic hydrolysis for the generation of porous starches. The results showed that both the thermal and mechanical effects have the capacity to disorganize/alter the structure of starch, impacting on its properties. Characteristics such as particle size, pasting and thermal properties (peak viscosity 1400-1800 cp.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!