Tea, from the plant camellia sinensis, is consumed in different parts of the world as green, black or oolong tea. Among all of these, however, the most significant effects on human health have been observed with the consumption of green tea. Green tea contains polyphenols, which include flavanols, flavandiols, flavonoids, and phenolic acids. Most of the green tea polyphenols (GTPs) are flavonols, commonly known as catechins. There are four kinds of catechins mainly find in green tea: epicatechin, epigallocatechin, epicatechin-3-gallate, and EGCG. Green tea catechins have demonstrated significant antioxidant, anticarcinogenic, anti-inflammatory, thermogenic, probiotic, and antimicrobial properties in numerous human, animal, and in vitro studies. In the present study, four type catechins of green tea were studied. For each catechin ab initio method was employed for calculations and related parameters were computed.
In the present study, adsorption of helium, neon, argon and binary mixtures of one of them with hydrogen on (5, 5) armchair silicon nanotube at Temperatures of 50, 100 and 150K and Pressures of 1, 5, 7, 10 and 15MPa were studied. For each binary mixture three different mole fractions of hydrogen were examined. Canonical Monte Carlo simulation by ab-initio calculation was employed for studding the adsorption of above gases on single-walled silicon nanotubes (SW-Si-NTs). The interaction energy of gases with the surfaces of the single Si-NTs obtained from quantum mechanics calculations was fitted to an exact potential functions used for simulating the system. Lennard-Jones potential was used for gas-gas and Morse potential was used for gas-silicon nanotubes interaction. The work was carried out at several temperatures and pressures by using Canonical-Monte-Carlo or CMC simulation in order for studding the effect of temperature and pressure on gas adsorption. The adsorption results showed that by increasing the pressure and decreasing the temperature, the amount of adsorption increases. It was concluded that among the rare gases discussed helium was lowest impact on hydrogen adsorption in a mixture of helium and hydrogen.
We report the stability and electronic structures of the double wall boron nitride nanotubes (DWBNNTs) due to interaction with anode lithium ion batteries (LIBs). Nano-Boron Nitride compounds have displayed great potential as anode materials for lithium ion batteries due to their unique
structural, mechanical, and electrical properties. The measured reversible lithium ion capacities of SWBNTs//(Li)n//SWBNTs based anodes are considerably improved compared to the conventional graphite-based anodes. In this study (5, 5)@(7, 7) DWBNNTs, (5, 5)@(8, 8) DWBNNTs and (5, 5)@(9,
9) DWBNNTs have been localized inside the LIBs as an nano-capacitor to enhance electrochemical ratio of lithium ion capacities. Additionally, we have found the structure of (5, 5)@(8, 8) DWBNNTs can be to improve the capacity and electrical transport in anode-based LIBs. Therefore, the modification
of cylindrical of BN and design of SWBNTs//(Li)n//SWBNTs structures provide strategies for improving the performance of material based anodes in LIBs. SWBNTs//(Li)n//SWBNTs could also be assembled into free-standing electrodes without any binder or current collector, which will
lead to increased specific energy density for the overall battery design.
Multi layers Graphene has been simulated theoretically for hydrogen storage and oxygen diffusion at a single unit of fuel cell. Ion transport rate of DFAFC, PAFC, AFC, PEMFC, DMFC and SOFC fuel cells have been studied. AFC which uses an aqueous alkaline electrolyte is suitable for temperature below 90 degree and is appropriate for higher current applications, while PEMFC is suitable for lower temperature compared to others. Thermodynamic equations have been investigated for those fuel cells in viewpoint of voltage output data. Effects of operating data including temperature (T), pressure (P), proton exchange membrane water content (λ) , and proton exchange membrane thickness on the optimal performance of the irreversible fuel cells have been studied.Obviously, the efficiency of PEMFC extremely related to amount of the H2 concentration, water activities in catalyst substrates and polymer of electrolyte membranes, temperature, and such variables dependence in the direction of the fuel and air streams.
Graphene and h-BN have been theoretically simulated for hydrogen storage and oxygen diffusion in a single fuel cell unit. Obviously, the efficiency of the PEM hydrogen fuel cells was significantly related to the amount of H2 concentration, the water activities in catalyst substrates and the polymer of the electrolyte membranes, the temperature and the dependence of such variables in the direction of the fuel and air currents between the anode path and the cathode. The single PEM parameter has been estimated and the results show greater fuel cell efficiency using graphene sheets and h-BN. Maximum efficiency is observed with the stoichiometry of the 5H2, 5O2 and 3 C2F4 molecules during adsorption.
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