Using molecular dynamics simulations, we have predicted the thermal conductivity of Bi2Te3 nanowires with diameters ranging from 3 to 30 nm with both smooth and rough surfaces. It is found that when the nanowire diameter decreases to the molecular scale (below 10 nm, or the so-called “quantum wire”), the thermal conductivity shows significant reduction as compared to bulk value. On the other ha...

In this paper we have studied the effect of magneto-static field onpropagation of thermal wave generated in metal by pulsed laser. In fact this interactiongenerate acoustic wave in different mechanisms. However, always the commonmechanism in the interactions of laser pulse and metal is the thermo-elastic wavegeneration. Applying the suitable magneto-static field on the s...

Cationic waterborne polyurethane as a new dispersing polymer was synthesized by using relatively hydrophilic polyols. Dispersing cationic polyurethane (DCPU) nanocomposites were prepared using isophorone diisocyanate (IPDI), polyethylene glycol (PEG) with different molecular weights (Mn=200, 400, 600,and1000 g/mol), N-methyl diethanolamine (MDEA), dibutyltin dilaurate (DBTDL) and different perc...

Understanding thermal transport in nanostructured materials is important for the development of energy conversion applications and the thermal management of microelectronic and optoelectronic devices. Most nanostructures interact through van der Waals interactions, and these interactions typically lead to a reduction in thermal transport. Here, we show that the thermal conductivity of a bundle ...

On the materials scale, thermoelectric efficiency is defined by the dimensionless figure of merit zT . This value is made up of three material components in the form zT = Tα/ρκ, where α is the Seebeck coefficient, ρ is the electrical resistivity, and κ is the total thermal conductivity. Therefore, improving zT would require the reduction of κ and ρ while increasing α. However, due to the inter-...

Theoretical and experimental study of transient heat transfer parameters related to downward flowing water in a circular concentric annular channel is conducted. The cooling channel is exposed internally to sinusoidal heat flux and has an adiabatic outer surface. The present theoretical study investigated the heat transfer and thermodynamic parameters during of 25%, 50%, and 75% flow reduction ...

In this paper, the anisotropic thermal conductivity characteristics of graphene wrinkles are observed for the first time using a non-equilibrium molecular dynamics method. Our results reveal that the wrinkling level has little effect on the thermal conductivity along the wrinkling direction. However, the wrinkling level plays an important role in the reduction of thermal conductivity along the ...

The thermal impedance Zth j has been measured for the junction of a transistor mounted on a cooling fin. The setup was put inside a chimney in order to enhance the natural convection cooling. From the thermal impedance Zth j the influence of the chimney on the reduction in thermal resistance Rth Zth j 0 is clearly visible. A maximum improvement of almost 20% has been observed experimentally. Me...

A series of single-phase polycrystalline (TlSbTe2)x(Tl0.02Pb0.98Te)1−x (x= 0, 0.05, 0.1) compounds were made to reduce thermal conductivity while maintaining the enhanced Seebeck coefficients found in PbTe doped with Tl. Transport property measurements confirmed that high Seebeck coefficients from doping with Tl are retained by alloying with TlSbTe2. At the same time, a thermal conductivity as ...

We study the realization of dimensional reduction and the validity of the hard thermal loop expansion for λφ theory at finite temperature, using an environmentally friendly finite–temperature renormalization group with a fiducial temperature as flow parameter. The one–loop renormalization group allows for a consistent description of the system at low and high temperatures, and in particular of ...