In this study, we investigated the thermal conductivity characteristics of MWCNT, cobaltencapsulated MWCNT (Co@MWCNT), and hybrid Co@MWCNT/SiC nanofluids, focusing on their thermal conductivity coefficients and specif...
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In this study, we investigated the thermal conductivity characteristics of MWCNT, cobaltencapsulated MWCNT (Co@MWCNT), and hybrid Co@MWCNT/SiC nanofluids, focusing on their thermal conductivity coefficients and specific heat under varying temperature and volume fraction conditions. The cobalt nanoparticles encapsulated in carbon nanotubes were synthesized using chemical methods and characterized through TEM, XRD, and FTIR techniques. The results indicate that cobalt nanocrystals are successfully encapsulated within carbon nanotubes, and SiC nanoparticles exhibit strong interactions with them. Notably, the hybrid composites can produce stable nanofluids with magnetic properties. The thermal conductivity coefficient is influenced by the pH of the solution, with optimal values typically found between pH 6 and 8 due to enhanced nanoparticle dispersion and reduced agglomeration in this range. As the concentration of cobalt and SiC nanoparticles increases, the thermal conductivity follows the trend of hybrid composites > Co@MWCNT > MWCNT. For instance, a 0.01 % increase in the volume fraction of hybrid nanoparticles can lead to a thermal capacity increase of up to 33 % compared to the base fluid. Moreover, applying a magnetic field of 0.05T can alter the thermal conductivity coefficient by enhancing the magnetic order of the cobalt atoms, often resulting in a 50 % increase in thermal capacity. Overall, the specific heat of these nanofluids varies with temperature and volume fractions, demonstrating a strong dependence on these factors. This study enhances the understanding of hybrid nanofluid properties and lays the groundwork for their practical applications in thermal management and energy systems.
An object-to-object color mapping method based on image segmentation is proposed. The pictorial color image is segmented into different object areas with clustered color distributions. Euclidian or Mahalanobis color d...
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An object-to-object color mapping method based on image segmentation is proposed. The pictorial color image is segmented into different object areas with clustered color distributions. Euclidian or Mahalanobis color distance measures, and Bayesian decision rule are introduced to the image segmentation. After the image segmentation, each segmented pixel is projected onto principal component space by Hotelling transform and the color mappings are performed for the principal components to be matched in between the individual objects of original and printed or displayed images. Experiments on the automatic color correction for inkjet prints and color mapping for preferred skin color reproduction are reported. The paper further discusses how the setting of initial seeds points affects the image segmentation results. (C) 2001 SPIE and IS&T.
Measurements of partial derivatives of displacements;geometrical study of deformation caused by rolling;ellipsis of deformation;rotation and sliding;results are only approximative.
Measurements of partial derivatives of displacements;geometrical study of deformation caused by rolling;ellipsis of deformation;rotation and sliding;results are only approximative.
A procedure for the preparation of multiple post and core patterns has been presented. The method is efficient and eliminates impressions of the canals. Several core buildups can be completed simultaneously at one app...
A procedure for the preparation of multiple post and core patterns has been presented. The method is efficient and eliminates impressions of the canals. Several core buildups can be completed simultaneously at one appointment.
The refractive index, polarizability and thermodynamic response of polystyrene under shock compression were investigated through experiments and theoretical analysis, and a relationship between the refractive index an...
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The refractive index, polarizability and thermodynamic response of polystyrene under shock compression were investigated through experiments and theoretical analysis, and a relationship between the refractive index and the density, pressure and temperature of the polystyrene was obtained. Above a pressure of 20 GPa, an obvious inflexion was observed in how the refractive index of the polystyrene varied with the thermodynamic variables;in particular, it was found to depend strongly on the temperature (as obtained using a semiempirical complete equation of state). Relating the measured refractive index to the polarizability indicates that the polarizability decreased from 1.28 x 10(-23) cm(3) at ambient conditions, to 0.98 x 10(-23) cm(3) at pressure of 33 GPa, indicating that the lowest direct band gap of polystyrene becomes < 2 eV, similar to that of many semiconductor materials.
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