Influence of Particle Size Distribution on the Optical Properties of Fine-Dispersed Suspensions

CoSbS-based compounds are good thermoelectric materials with low thermal conductivity and good electrical properties, which can effectively be used to improve the efficiency of many thermoelectric conversion processes. In order to improve their properties even more, in this study a series of experiments have been conducted in the frame of the traditional solid-phase synthesis and high-pressure method. It is shown that if the mass fluctuation and stress fluctuation in the considered CoSbS system increase, the scattering probability of phonons is enhanced and the lattice thermal conductivity of the material is reduced. Adding a small amount of Se can simultaneously optimize three thermoelectric properties, i.e., the Seebeck coefficient is improved, the thermal conductivity becomes smaller and the quality factor grows. At the same time, the thermal and electrical properties of bulk materials can be optimized by using nano-scale Ni doped CoSbS samples. As shown by the experiments, Nidoped Co sites can effectively improve the carrier concentration, the effective mass of the density of states of the material, and the power factor. Under the same temperature conditions, the thermoelectric figure of merit (ZT) of Co 1−y Ni y SbS 1−x Se x synthesized under high pressure, at x = 0.15, y = 0.1 is much higher than the corresponding value for CoSbS prepared by traditional methods.

Section: Theoretical Analysis 21 Seebeck Effectmentioning

confidence: 99%

Section: Preparation and Properties Of Micro Nano Composite Thermoele...mentioning

confidence: 99%

Optimization of the Thermoelectric Performances of CoSbS Semiconductors Using the High-Pressure Fabrication Method

Liu¹,

You²,

Wang³

2022

“…At the same time, the existence of fractures in the formation is conducive to wider pressure propagation. To better describe the fractures distributed in different directions, the EDFM model is adopted in this paper [26,27]. See Appendix B for its control equation and calculation principle.…”

Section: The Effect Of Fracturementioning

confidence: 99%

A Comprehensive Study on the Process of Greenhouse Gas Sequestration Based on a Microporous Media Model

Wang¹,

Zhang²,

Zhang³

et al. 2022

Carbon dioxide geological sequestration is an effective method to reduce the content of greenhouse gases in the atmosphere of our planet. This process can also be used to improve the production of oil reservoirs by mixing carbon dioxide and crude oil. In the present study, a differential separation experiment (DL) based on actual crude oil components is used to simulate such a process. The results show that after mixing, the viscosity and density of reservoir fluid decrease and the volume coefficient increase, indicating that the pre buried gas induces fluid expansion and an improvement of the fluid rheological properties. These effects are interpreted using a pore scale model based on real scanning electron microscopy (SEM). The results show that increasing the pressure and reducing the viscosity are beneficial to increasing the micro oil displacement efficiency. Moreover, these effects can improve the production in the target area and slow down the decline of the formation pressure. Furthermore, in the case of fracture development in the reservoir (due to CO 2 injection before exploitation), the risk of gas channelling, induced by the displacement pressure difference between injection and production wells, is avoided.

“…The work in [42] gives an extensive review of strategies based, among others, on nanofluids for solving "internal heat generation problem" for the optimization of heat transfer in electronic devices. The work in [43] explores the significant potential of nanofluids, and specifically the influence of nano-particle size and distribution, in solar energy harvesting. The importance of viscoelastic fluid in heat generation/absorption is also explored in [44] using Maxwell fluids.…”

mentioning

confidence: 99%

Computational-Analysis of the Non-Isothermal Dynamics of the Gravity-Driven Flow of Viscoelastic-Fluid-Based Nanofluids Down an Inclined Plane

Khan¹,

Chinyoka²,

Gill³

2023

The paper explores the gravity-driven flow of the thin film of a viscoelastic-fluid-based nanofluids (VFBN) along an inclined plane under non-isothermal conditions and subjected to convective cooling at the free-surface. The Newton's law of cooling is used to model the convective heat-exchange with the ambient at the free-surface. The Giesekus viscoelastic constitutive model, with appropriate modifications to account for non-isothermal effects, is employed to describe the polymeric effects. The unsteady and coupled non-linear partial differential equations (PDEs) describing the model problem are obtained and solved via efficient semi-implicit numerical schemes based on finite difference methods (FDM) implemented in Matlab. The response of the VFBN velocity, temperature, thermal-conductivity and polymeric-stresses to variations in the volume-fraction of embedded nanoparticles is investigated. It is shown that these quantities all increase as the nanoparticle volume-fraction becomes higher. KEYWORDSSemi-implicit numerical scheme; finite difference methods; viscoelastic-fluid-based nanofluid (VFBN); nonisothermal viscoelastic flow; giesekus constitutive model; nanofluid thermal-conductivity; gravity-driven flow Nomenclature Variables and ConstantsÃ