The synovial fluid motion in an artificial hip joint is important in understanding the thermo-fluids effects that can affect the reliability of the joint, although it is difficult to be studied theoretically, as the modelling involves the viscous fluid interacting with a moving surface. A new analytical solution has been derived for the maximum induced fluid motion within a spherical gap with an oscillating lower surface and a stationary upper surface, assuming one-dimensional incompressible laminar Newtonian flow with constant properties, and using the Navier-Stokes equation. The resulting time-dependent motion is analysed in terms of two dimensionless parameters R and β, which are functions of geometry, fluid properties and the oscillation rate. The model is then applied to the conditions of the synovial fluid enclosed in the artificial hip joint and it is found that the motion may be described by a simpler velocity variation, whereby laying the foundation to thermal studies in the joint.
Efficient heat dissipation is crucial for various industrial and technological applications, ensuring system reliability and performance. Advanced thermal management systems rely on materials with superior thermal conductivity and stability for effective heat transfer. This study investigates the thermal conductivity, viscosity, and stability of hybrid Al2O3-CuO nanoparticles dispersed in Therminol 55, a medium-temperature heat transfer fluid. The nanofluid formulations were prepared with CuO-Al2O3 mass ratios of 10:90, 20:80, and 30:70 and tested at nanoparticle concentrations ranging from 0.1 wt% to 1.0 wt%. Experimental results indicate that the hybrid nanofluids exhibit enhanced thermal conductivity, with a maximum improvement of 32.82% at 1.0 wt% concentration, compared to the base fluid. However, viscosity increases with nanoparticle loading, requiring careful optimization for practical applications. To further analyze and predict thermal conductivity, a Type-2 Fuzzy Neural Network (T2FNN) was employed, demonstrating a correlation coefficient of 96.892%, ensuring high predictive accuracy. The integration of machine learning enables efficient modeling of complex thermal behavior, reducing experimental costs and facilitating optimization. These findings provide insights into the potential application of hybrid nanofluids in solar thermal systems, heat exchangers, and industrial cooling applications.
Porous carbons with their abundant availability and high electrical conductivity present significant potential as cathode materials for Na-S batteries. In this study, we report the synthesis of nitrogen and phosphorus co-doped porous carbon (P-N co-doped PC) through a one-step carbonization process utilizing ammonium polyphosphate as the source of nitrogen and phosphorus. The average reversible capacities for P-N co-doped PC were 920, 861, 823 and 756 mA h g-1 at current densities of 0.2, 0.5, 1.0 and 2.0 C, respectively. Notably, upon returning to current densities of 1.0, 0.5 and 0.2 C, the capacities were restored to 805, 853 and 906 mA h g-1, highlighting the exceptional stability of the P-N co-doped PC. The pronounced capacitive storage mechanism of P-N co-doped PC can be attributed to the presence of numerous surface defects and active sites resulting from the co-doping of nitrogen and phosphorus. In particular, the remarkable cycling stability exhibited by the P-N co-doped PC can be ascribed to the exceptional stability of the surface layer that has undergone phosphorus doping, thereby facilitating the migration of ions. This research contributes valuable insights into the development of advanced Na-S batteries through the utilization of heteroatom-doped functionalized porous carbons.
This paper presents the development and experimental analysis of a curved microelectrode platform for the DEP deformation of breast cancer cells (MDA-MB-231). The platform is composed of arrays of curved DEP microelectrodes which are patterned onto a glass slide and samples containing MDA-MB-231 cells are pipetted onto the platform's surface. Finite element method is utilised to characterise the electric field gradient and DEP field. The performance of the system is assessed with MDA-MB-231 cells in a low conductivity 1% DMEM suspending medium. We applied sinusoidal wave AC potential at peak to peak voltages of 2, 5, and 10 Vpp at both 10 kHz and 50 MHz. We observed cell blebbing and cell shrinkage and analyzed the percentage of shrinkage of the cells. The experiments demonstrated higher percentage of cell shrinkage when cells are exposed to higher frequency and peak to peak voltage electric field.
The recent advancement of dielectrophoresis (DEP)-enabled microfluidic platforms is opening new opportunities for potential use in cancer disease diagnostics. DEP is advantageous because of its specificity, low cost, small sample volume requirement, and tuneable property for microfluidic platforms. These intrinsic advantages have made it especially suitable for developing microfluidic cancer diagnostic platforms. This review focuses on a comprehensive analysis of the recent developments of DEP enabled microfluidic platforms sorted according to the target cancer cell. Each study is critically analyzed, and the features of each platform, the performance, added functionality for clinical use, and the types of samples, used are discussed. We address the novelty of the techniques, strategies, and design configuration used in improving on existing technologies or previous studies. A summary of comparing the developmental extent of each study is made, and we conclude with a treatment of future trends and a brief summary.