The primary objective of this study is to investigate the effect of slip mechanisms in nanofluids through scaling analysis. The role of nanoparticle slip mechanisms in both water- and ethylene glycol-based nanofluids is analyzed by considering shape, size, concentration, and temperature of the nanoparticles. From the scaling analysis, it is found that all of the slip mechanisms are dominant in particles of cylindrical shape as compared to that of spherical and sheet particles. The magnitudes of slip mechanisms are found to be higher for particles of size between 10 and 80 nm. The Brownian force is found to dominate in smaller particles below 10 nm and also at smaller volume fraction. However, the drag force is found to dominate in smaller particles below 10 nm and at higher volume fraction. The effect of thermophoresis and Magnus forces is found to increase with the particle size and concentration. In terms of time scales, the Brownian and gravity forces act considerably over a longer duration than the other forces. For copper-water-based nanofluid, the effective contribution of slip mechanisms leads to a heat transfer augmentation which is approximately 36% over that of the base fluid. The drag and gravity forces tend to reduce the Nusselt number of the nanofluid while the other forces tend to enhance it.
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http://dx.doi.org/10.1186/1556-276X-6-471 | DOI Listing |
J Orthop Case Rep
January 2025
Department of Orthopedic Surgery, Mayo Clinic College of Medicine and Science, Mayo Clinic, Phoenix AZ, USA.
Introduction: Femoral nerve injury is a recognized complication of abdominal, pelvic, and orthopedic surgeries. It can also occur due to pelvic fractures, intra-abdominal trauma, and hip injuries. These injuries often result in pain, weakness, and difficulty with ambulation, significantly impacting a patient's quality of life.
View Article and Find Full Text PDFSensors (Basel)
December 2024
State Key Laboratory of Tribology in Advanced Equipment, Tsinghua University, Beijing 100084, China.
To avoid wear and tear of the slip ring due to electrical corrosion, the slip ring needs to undergo the running-in process under atmospheric conditions without current after assembly. To address the urgent demand for long-service capability space conductive slip rings in the aerospace field, the running-in behavior and failure mechanism between the AgCuNi alloy and Au-electroplated layer are investigated using a ball-on-disc tribometer in this paper. The results show that the transfer film composed of Au plays an important role in modifying the friction during the sliding process.
View Article and Find Full Text PDFMaterials (Basel)
December 2024
School of Materials Science and Engineering, Taiyuan University of Science and Technology, Taiyuan 030024, China.
Damage mechanisms are a key factor in materials science and are essential for understanding and predicting the behavior of materials under complex loading conditions. In this paper, the influence of different directions, different rates and different model parameters on the mechanical behavior of AZ31 magnesium alloy during the tensile process is investigated based on the secondary development of the VUMAT user subroutine based on the GTN damage model and verified by the tensile experiments at different loading rates and in different directions. The results show that AZ31 magnesium alloy exhibits significant differences in mechanical properties in radial and axial stretching, where the yield strength is lower in the radial direction than in the axial direction, and the elongation is the opposite.
View Article and Find Full Text PDFLangmuir
January 2025
R&D - Analytical Science Research, Kao Corporation, 1334 minato, Wakayama, Wakayama 640-8580, Japan.
The adsorption behavior of an anionic surfactant, hydroxy alkane sulfonate with an alkyl chain length of 18 (C18HAS), from its hard water solution onto a mica surface and resulting lubrication properties were investigated. Because of the double chain-like chemical structure and aggregation behavior, C18HAS formed vesicles in hard water, which adsorbed onto a negatively charged mica surface via cation (Ca) bridging and then transformed into a bilayer film. The number of bilayers formed on the surface was evaluated by force curve measurements using an atomic force microscope (AFM), and the results showed a time-dependent increase of the number of adsorbed bilayers.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
January 2025
Institut Langevin, École Supérieure de Physique et de Chimie Industrielles de la Ville de Paris, Université Paris Sciences & Lettres, CNRS, Paris 7587, France.
Understanding the dynamic response of granular shear zones under cyclic loading is fundamental to elucidating the mechanisms triggering earthquake-induced landslides, with implications for broader fields such as seismology and granular physics. Existing prediction methods struggle to accurately predict many experimental and in situ landslide observations due to inadequate consideration of the underlying physical mechanisms. The mechanisms that influence landslide dynamic triggering, a transition from static (or extremely slow creeping) to rapid runout, remain elusive.
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