Calculation of the thermal conductivity of human serum albumin (HSA) with equilibrium/non-equilibrium molecular dynamics approaches.

BACKGROUND AND OBJECTIVE: Human serum albumin (HSA) controls the flow of numerous chemical structures and molecules in the cardiovascular system. So, thermal conductivity of this atomic compound is important in medicinal applications. METHODS: In this work, the thermal conductivity of HSA is calculated with equilibrium/non-equilibrium molecular dynamic approaches. In these methods each HSA molecule is exactly represented by C, N, O and S atoms and their implemented dreiding potential. Finally by using Green-Kubo and Fourier's law the thermal conductivity of HSA/H2O mixture is calculated. RESULTS: Our calculated rates for thermal conductivity via equilibrium/non-equilibrium molecular dynamics methods are 0.496 W/m K and 0.448 W/m K, respectively. The calculated thermal conductivity for this structure was very close to the thermal conductivity calculated for water molecules which were reported by other research groups. Furthermore our simulated structures show that thermal conductivity of HAS/H2O mixtures has inverse relation with HAS molecules numbers and temperature of simulated atomic structures. CONCLUSIONS: Comparing thermal conductivity from equilibrium/non-equilibrium molecular dynamics methods for HAS/H2O shows that EMD and NEMD results are reliable and EMD calculated results are higher than NEMD results.

Investigation of thermal properties of DNA structure with precise atomic arrangement via equilibrium and non-equilibrium molecular dynamics approaches.

BACKGROUND AND OBJECTIVE: Thermal conductivity of Deoxyribonucleic acid molecules is important for nanotechnology applications. Theoretical simulations based on simple models predict thermal conductivity for these molecular structures. METHODS: In this work, we calculate the thermal properties of Deoxyribonucleic acid with precise atomic arrangement via equilibrium and non-equilibrium molecular dynamics approaches. In these methods, each Deoxyribonucleic acid molecule is represented by C, N, O, and P atoms and implemented dreidng potential to describe their atomic interactions. RESULTS: Our calculated rate for thermal conductivity via equilibrium and non-equilibrium molecular dynamics methods is 0.381 W/m K and 0.373 W/m K, respectively. By comparing results from these two methods, it was found that the results from equilibrium and non-equilibrium molecular dynamics methods are identical, approximately. On the other hand, the number of DNA molecules and the equilibrium temperature of the simulated structures were important factors in their thermal conductivity rates, and their thermal conductivity was calculated at 0.323 W/m K-0.381 W/m K intervals for equilibrium and 0.303 W/m K-0.373 W/m K interval for non-equilibrium calculations. CONCLUSIONS: These results are in good agreement with thermal conductivity calculation with other research groups.