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Thermal energy and its storage systems play an extensive role in day-to-day life. They store renewable energy and are capable of recovering generated heat from different systems. Storage of thermal energy can be classified into three types: sensible, latent and sorption heat storages. Thermal heat storages use different types of materials based on their capacity of heat storage, stability of duration and thermal conductivity. Various phase change materials (PCMs) that are suitable for thermal storage are reported. Low conversion ability limits their effectiveness. We reviewed some of the traditional materials synthesized recently that are used for thermal energy storage (TES). Recently developed TES materials exhibit high thermal conductivity, reduced super cooling and multiple phase change temperatures. Nano-enhanced PCMs produced an increase in thermal conductivity up to 32% with a reduction in latent heat by 32%. At this juncture, MXenes with high performance and extraordinary properties (thermal, mechanical, etc.) are of special significance. MXenes displayed an increased thermal conductivity up to 16% and 94% efficiency. In view of their structure and adaptability to be used in thermal storage systems, an attempt was made to review their role also in thermal storage applications. It is observed that MXenes highly impact storage and efficiency. Apart from MXenes, various types of PCMs along with their thermal characteristics are presented. Organic PCM's exhibit low melting point and high latent heat making them significant for TES. Organic PCM's are widely used in TES systems for consolidation and maintenance of alternative energy. However, leakage during phase transition limits their practical applications. [ABSTRACT FROM AUTHOR]

The investigation of thermal transport in the nanofluid over a curved Riga surface is significant and extensively used in many industries as well as in engineering. Therefore, the study is conducted to analyze the thermal transport rate in H2O composed of nanomaterial, namely, carbon nanotubes (CNTs). To improve the thermal conductance, a thermal conductivity correlation based on the length and radius of CNTs is plugged in the energy equation. After that, the flow model was reduced into a self-similar form via feasible transformations and tackled numerically. From the plotted results, it is experienced that the nanofluid velocity drops against a more curved surface. The momentum boundary layer intensifies against larger curvature. An enhanced temperature is experienced in the nanofluid due to varying the parameters. Further, thermal conductivity of the nanofluids rises due to the high volume fraction factor, which plays a significant role in thermal transport. Moreover, the local thermal performance rises linearly against M.

The effects of a chemical reaction and radiative heat flux in a nonlinear mixed thermo-solutal convection flow of a viscoelastic nanoliquid from a stretchable surface are investigated theoretically. Newtonian heating is also considered. The upper-convected Maxwell (UCM) model is deployed to represent the non-Newtonian characteristics. The model also includes the influence of thermal radiation that is simulated via an algebraic flux model. Buongiorno’s two-component nanofluid model is implemented for thermophoretic and Brownian motion effects. Convective thermal and solutal boundary conditions are utilized to provide a more comprehensive evaluation of temperature and concentration distributions. Dimensionless equations are used to create the flow model by utilizing the appropriate parameters. The computed models are presented through a convergent homotopic analysis method (HAM) approach with the help of Mathematica-12 symbolic software. Authentication of HAM solutions with special cases from the literature is presented. The impact of various thermophysical, nanoscale and rheological parameters on transport characteristics is visualized graphically and interpreted in detail. Temperatures are strongly enhanced with Brownian motion and thermophoresis parameters. Velocity is boosted with the increment in the Deborah viscoelastic number and mixed convection parameter, and the hydrodynamic boundary layer thickness is reduced. A stronger generative chemical reaction enhances concentration magnitudes, whereas an increment in the destructive chemical reaction reduces them and also depletes the concentration boundary layer thickness. Temperature and concentration are also strongly modified by the conjugate thermal and solutal parameters. Greater radiative flux also enhances the thermal boundary layer thickness. Increasing the Schmidt number and the Brownian motion parameter diminish the concentration values, whereas they elevate the Sherwood number magnitudes, i.e. enhance the nanoparticle mass transfer rate to the wall.

The AlxCo1‐xTiO3+δ (x = 0.2, 0.4, 0.6 & 0.8) (ACTO) nanoparticles are synthesized via hydrothermal method at low operating temperature of 423 K/8 h. The diiffraction patterns confirm the tetragonal phases of ACTO along with the secondary phases (*Co3O4). The morphology shows the homogeneous distribution of nanoparticles. In addition, for x = 0.2–0.4, a = b & c values are found to be decreasing from 0.3776 to 0.3771 nm & 0.8887–0.8878 nm, respectively, while for x = 0.6–0.8, the same values are found to be decreasing from 0.3780 to 0.3778 nm & 0.8881–0.8879 nm, respectively. The M–H curves provide the pure paramagnetic nature for x = 0.6 & 0.8 while the weak ferromagnetic nature for x = 0.2 & 0.4. At 8 MHz, the ɛ′ value of x = 0.2 (high cobalt content) shows the stabilized ɛ′ of ≈32.5 and the ɛ″ values of ACTO are changing from ≈1.6–10.6. Therefore, the x = 0.2 shows the high ɛ′ & ɛ″ suitable for high frequency dielectric absorber applications. The exponent “n” values determined using power law fit are noted to be increasing from 0.512 to 0.852 for x = 0.2–0.6 while the same is decreased to 0.664 for x = 0.8. All the “n” values are less than one and shows that the polaron hopping is slower than site relaxation. The mass loss, decomposition of various ingredient species, and other transition temperatures are evaluated by thermal study. [ABSTRACT FROM AUTHOR]

Complexes of the type [M(DTC)2 (H2O)2] where M=Ru and La and Nacs2 L= sodium salt of histamine dithiocarbomate ligands have been synthesised and characterised by physico chemical (elemental analysis, conductance magnetic susceptibility measurements) and spectral techniques Infrared spectroscopy, magnetic susceptibility, ultraviolet and Atomic absorption spectroscopy, ¹HNMR spectroscopy. The FT-IR spectra of the complex indicate that ligand behave as a abidentate manner coordinating via nitrogen and sulphur for their structures and studied for structure activity relationship with complexes the anionic metal ligand complexes exhibit octahedral geometry. Thermal behaviour of these chealates show hydrated complexes losses water molecules of hydration in the first step. In thermogravitic analysis first step followed immediately by decomposition of the coordinated water, anions and ligands is the subsequent steps. [ABSTRACT FROM AUTHOR]