A quest to extend friction law into multiscale soft matter: experiment confronted with theory—a review

Bełdowski, Piotr; Gadomski, Adam

doi:10.1088/1361-6463/ac90d1

Cited by 3 publications

(2 citation statements)

References 99 publications

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“…The interaction of hyaluronic acid and phospholipids is responsible for the repairment of the surfaces of articular cartilage. The modeling and simulation of such interactions can be helpful in further understanding the pathological conditions of the synovial joint, and the properties of the squeeze film in the synovial joint are significant for the formulation of bio-tribological surgical advancements [28,47]. As we have just seen in the results presented above, the pressure increases when activity and disease states are present and when squeezing velocity and viscosity increase as well.…”

Section: Parameter Valuesmentioning

confidence: 89%

Effect of Significant Parameters on Squeeze Film Characteristics in Pathological Synovial Joints

et al. 2023

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Synovial joints are unique biological tribo-systems that allow for efficient mobility. Most of the synovial joint activities in the human body are accomplished due to the presence of synovial fluid. As a biological lubricant, synovial fluid lubricates the articular cartilage to minimize wear and friction. The key components of synovial fluid that give it its lubricating ability are lubricin, hyaluronic acid (HA), and surface-active phospholipids. Due to age and activities, synovial fluid and articular cartilages lose their properties, restricting synovial joint mobility and resulting in articular cartilage degradation, leading to the pathological synovial joint, which is a major cause of disability. In this context, synovial joint research remains significant. Even though synovial joint lubrication has been investigated, several problems linked to squeeze film lubrication need greater attention. The Newtonian model of squeeze film lubrication in synovial joints must be studied more extensively. This work aims to investigate squeeze film lubrication in diseased synovial joints. The lubrication and other properties of synovial fluid and the flow of synovial fluid in a diseased human knee joint are investigated theoretically in this work. We have investigated the effect of the synovial fluid viscosity and the effects of permeability and thickness of articular cartilage on squeeze film properties. Moreover, we have also investigated the effect of squeeze velocity and film thickness on the characteristics of the squeeze film formed between the articular cartilages of a diseased human knee joint. In this work, the articular cartilages were treated as a rough, porous material, and the geometry was approximated as parallel rectangular plates, while the synovial fluid flow is modeled as a viscous, incompressible, and Newtonian fluid. The modified Reynolds equation is obtained using the principles of hydrodynamic lubrication and continuum mechanics, and it is solved using the appropriate boundary conditions. The expressions for pressure distribution, load-bearing capacity, and squeezing time are then determined, and theoretical analysis for various parameters is conducted. Pressure is increased by squeeze velocity and viscosity, while it is decreased by permeability and film thickness, leading to an unhealthy knee joint and a reduction in knee joint mobility. The load capacity of the knee joint decreases with permeability and increases with viscosity and squeezing velocity, resulting in a reduction in the load-carrying capacity of the knee joint in diseased conditions. Synovial knee joint illness is indicated by increased pressure and squeeze time. The squeeze film properties of synovial joints are important for maintaining joint health and function. Joint diseases such as osteoarthritis, rheumatoid arthritis, and gout can affect the composition and production of synovial fluid, leading to changes in squeeze film properties and potentially causing joint damage and pain. Understanding these relationships can help in the development of effective treatments for joint diseases.

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Section: Parameter Valuesmentioning

confidence: 89%

Effect of Significant Parameters on Squeeze Film Characteristics in Pathological Synovial Joints

et al. 2023

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“…We note that similar challenges of modeling scale and tissue heterogeneity, from the meso–macroscopic level all the way down to the nano–meso level of molecular interfaces, arise in other contexts. For example, in biorheology one must choose the biophysical compartments and the linear versus extended Onsager formalism with which to model non-equilibrium thermodynamics [ 28 ]. Overall, although the calorimetry method does not provide any information about the temperature distribution, it remains the most accurate method with which to estimate the total amount of heat stored internally from the balance of heat flows.…”

Section: Discussionmentioning

confidence: 99%

Continuous Monitoring of Entropy Production and Entropy Flow in Humans Exercising under Heat Stress

Brodeur,

Notley,

Kenny

et al. 2023

Entropy

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Complex living systems, such as the human organism, are characterized by their self-organized and dissipative behaviors, where irreversible processes continuously produce entropy internally and export it to the environment; however, a means by which to measure human entropy production and entropy flow over time is not well-studied. In this article, we leverage prior experimental data to introduce an experimental approach for the continuous measurement of external entropy flow (released to the environment) and internal entropy production (within the body), using direct and indirect calorimetry, respectively, for humans exercising under heat stress. Direct calorimetry, performed with a whole-body modified Snellen calorimeter, was used to measure the external heat dissipation from the change in temperature and relative humidity between the air outflow and inflow, from which was derived the rates of entropy flow of the body. Indirect calorimetry, which measures oxygen consumption and carbon dioxide production from inspired and expired gases, was used to monitor internal entropy production. A two-compartment entropy flow model was used to calculate the rates of internal entropy production and external entropy flow for 11 middle-aged men during a schedule of alternating exercise and resting bouts at a fixed metabolic heat production rate. We measured a resting internal entropy production rate of (0.18 ± 0.01) W/(K·m2) during heat stress only, which is in agreement with published measurements. This research introduces an approach for the real-time monitoring of entropy production and entropy flow in humans, and aims for an improved understanding of human health and illness based on non-equilibrium thermodynamics.

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Friction force-based measurements for simultaneous determination of the wetting properties and stability of superhydrophobic surfaces

Beitollahpoor

Farzam

Pesika

2023

Journal of Colloid and Interface Science

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A quest to extend friction law into multiscale soft matter: experiment confronted with theory—a review

Cited by 3 publications

References 99 publications

Effect of Significant Parameters on Squeeze Film Characteristics in Pathological Synovial Joints

Effect of Significant Parameters on Squeeze Film Characteristics in Pathological Synovial Joints

Continuous Monitoring of Entropy Production and Entropy Flow in Humans Exercising under Heat Stress

Friction force-based measurements for simultaneous determination of the wetting properties and stability of superhydrophobic surfaces

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