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  • Publication
    Investigating the effect of the number of layers of the atomic channel wall on Brownian displacement, thermophoresis, and thermal behavior of graphene/water nanofluid by molecular dynamics simulation
    (ELSEVIER, 2024) Guo, Xinwei; Jasim, Dheyaa J.; Alizadeh, Asad; Keivani, Babak; Nasajpour-Esfahani, Navid; Salahshour, Soheil; Shamsborhan, Mahmoud; Sabetvand, Rozbeh; North China University of Water Resources & Electric Power; Shanghai Jiao Tong University; Al-Amarah University College; Cihan University-Erbil; Kirsehir Ahi Evran University; University System of Georgia; Georgia Institute of Technology; Okan University; Bahcesehir University; Lebanese American University; University of Zakho; Amirkabir University of Technology; Xi'an University of Science & Technology
    Nanofluids (NFs) are nanoscale colloidal suspensions containing dense nanomaterials. They are two-phase systems with solid in liquid phase. Due to their high thermal conductivity, nano -particles increase the thermal conductivity (TC) of base fluids, one of the basic heat transfer parameters, when distributed in the base fluids. The present research investigates the thermal behavior, Brownian motion, and thermophoresis of water/graphene NF affected by different numbers of atomic wall layers (4, 5, 6 and 7) by molecular dynamics (MD) simulation. This investigation reports changes in heat flux (HF), TC, average Brownian displacement, and ther-mophoresis displacement. By raising the number of atomic wall layers from 4 to 7, the average Brownian displacement and thermophoresis displacement increase from 3.06 angstrom and 23.88 angstrom to 3.62 and 25.05 angstrom, respectively. Increasing the number of layers due to the decrease in temper-ature increases the temperature difference between the hot and cold points along the channel. It increases the Brownian motion and the maximum temperature. Additionally, by raising the atomic layers of the channel wall, the values of HF and TC increase from 39.54 W/m2 and 0.36 W/mK to 41.18 W/m2 and 0.42 W/mK after 10 ns, respectively. The temperature rose from 1415 to 1538 K. These results are useful in different industries, especially for improving the thermal properties of different NFs.
  • Publication
    A numerical study of carbon doping effect on paraffin-reinforced silica aerogel mechanical properties: A molecular dynamics approach
    (ELSEVIER, 2023) Zhang, Wei; Jasim, Dheyaa J.; Alizadeh, As'ad; Nasajpour-Esfahani, Navid; Hekmatifar, Maboud; Sabetvand, Roozbeh; Salahshour, Soheil; Toghraie, D.; Xi'an Jiaotong University City College; Al-Amarah University College; Cihan University-Erbil; University System of Georgia; Georgia Institute of Technology; Islamic Azad University; Amirkabir University of Technology; Okan University; Bahcesehir University; Lebanese American University
    Aerogels are different types of porous and solid materials that exhibit a strange set of extraordinary material properties. Aerogels have great potential for use in the fields of heat, sound, electronics, and especially thermal insulation. This paper investigates the influence of carbon doping concentration on the mechanical properties of paraffin-reinforced silica aerogel (PRSA). To do this investigation, Young's module (YM), stress-strain curve, and ultimate strength (US) values at various carbon-doped particles of 1 to 10 % were reported by molecular dy-namics (MD) simulation. The results show that the PRSA, under the influence of carbon doping, has dual per-formance. To be more precise, by adding the amount of carbon doped from 1 to 3 %, the US and YM of the PRSA rose from 329.96 and 1137.20 MPa to 353.73 and 1268.44 MPa. In other words, the mechanical strength of the PRSA increases in a limited ratio. However, by increasing carbon doping from 3 to 10 %, the US and YM of the PRSA reduced to 306.233 and 1041.88 MPa, respectively. So, it is expected that the mechanical behavior of the PRSA matrix to be manipulated with carbon doping for actual applications.
  • Publication
    The nano-pumping process of C20 molecules from carbon nanotube at the different external electric fields and atomic defects: A molecular dynamics approach
    (ELSEVIER SCIENCE SA, 2024) Niu, Haichun; Rasheed, Rassol H.; Sajadi, S. Mohammad; Jasim, Dheyaa J.; Salahshour, Soheil; Nasajpour-Esfahani, Navid; Sabetvand, Rozbeh; University of Warith Alanbiyaa; Cihan University-Erbil; Al-Amarah University College; Okan University; Bahcesehir University; Lebanese American University; University System of Georgia; Georgia Institute of Technology; Amirkabir University of Technology
    Today, carbon nanotubes are involved in many medical types of research, such as biosensors and drug delivery. These nanotubes do not pose a problem for the body regarding toxicity to body cells and triggering the immune system. Nanotubes have also been proven to increase solubility and the possibility of targeted drug delivery. This study used molecular dynamics simulation to examine the nano-pumping process of the C20 molecule in carbon nanotubes at the different electric fields and atomic defects. The process of C20 molecule nano-pumping was examined by examining the changes in kinetic energy, potential energy, entropy, stress, temperature, and in-ternal energy changes. In the following, the stress on the atomic structure was calculated. For this purpose, constant electric fields with the magnitudes of 0.01, 0.02, 0.03, 0.05, and 0.1 V/angstrom are used for the atomic structure. The results show that the nano-pumping time of the C20 molecule in the carbon nanotubes increases by increasing the electric field magnitude. The results also revealed that the kinetic energy in the structure decreased by increasing the electric fields, and the potential energy increased. As the potential energy increased in the atomic structure, the stability increased. Therefore, it is expected that the C20 molecule nano-pumping time will increase. The following examined the effect of atomic defects in an electric field with a magnitude of 0.01 V/angstrom. For this purpose, the atomic defects with magnitudes of 1 %, 2 %, 3 %, and 4 % were used for carbon nanotubes. The results revealed that increasing the atomic defects increased the C20 molecule nano-pumping time. Furthermore, the stress on the structure increased by increasing the atomic defects.
  • Publication
    A numerical study of initial pressure effects on the water/silver nanofluid interaction with SARS-CoV-2 structure, a molecular dynamics method
    (ELSEVIER, 2024) Li, Xiaobo; Jasim, Dheyaa J.; Sajadi, S. Mohammad; Fan, Guang; Al-Rubaye, Ameer H.; Nasajpour-Esfahani, Navid; Salahshour, Soheil; Sabetvand, Rozbeh; Xianyang Normal University; Al-Amarah University College; Cihan University-Erbil; Al-Kitab University; University System of Georgia; Georgia Institute of Technology; Okan University; Bahcesehir University; Lebanese American University; Islamic Azad University
    The stability of the SARS virus can be affected by various environmental factors, including temperature, humidity, and pressure. In the present research, the effect of initial pressure on the stability of the SARS virus in the presence of water/Ag nanofluid (NF) is investigated using molecular dynamics (MD) simulation. The results revealed that initial pressure effectively changes the atomic evolution of the virus-NF system. Numerically, the diffusion coefficient of modeled samples changes from 32.33 nm2/ns to 9.489 nm2/ns by initial pressure varies from 1 bar to 10 bar. This structural evolution caused interatomic distance and force between virus particle changes. Finally, interaction energy is changed by initial pressure variation, and this parameter varies between -0.44695 kcal/mol to -24.65127 kcal/mol in defined initial conditions. From MD outputs, it was concluded physical stability of the SARS virus in the presence of water/silver NF can be manipulated by initial pressure. So, the SARS virus destruction process with water/silver NF affected from the initial pressure ratio, appropriately. Future directions for this research project may involve exploring the influence of additional environmental factors and utilizing the gained knowledge to develop antiviral materials. This study establishes a foundation for further investigations into the interaction between environmental factors, NFs, and viral infections, with the potential to contribute to the development of effective strategies for combating viral infections and designing innovative antiviral solutions.
  • Publication
    Using molecular dynamics approach to investigate the effect of copper nanoparticles on the thermal behavior of the ammonia/copper coolant by focusing on aggregation time
    (ELSEVIER, 2024) Fan, Zhongmian; Jasim, Dheyaa J.; Sajadi, S. Mohammad; Salahshour, Soheil; Nasajpour-Esfahani, Navid; Toghraie, D.; Shenyang University of Technology; Al-Amarah University College; Cihan University-Erbil; Okan University; Bahcesehir University; Lebanese American University; University System of Georgia; Georgia Institute of Technology; Islamic Azad University
    Nanofluids, fluids containing nanometer-sized particles, have significant properties which make them useful in devices and systems. They boost thermal conductivity and heat transfer better than base fluid. This research studied the atomic behavior, and thermal behavior of simulated ammonia -copper nanofluid using molecular dynamics (MD) simulation method. The effect of increasing Cu nanoparticles' volume fraction (phi) (1-10 %) on the atomic behavior and thermal behavior of nanofluids was studied. The atomic behavior of simulated structure was studied with velocity and temperature profiles. The maximum values of velocity and temperature were 0.00086 angstrom/ps and 240 K, respectively. To study the thermal behavior of simulated structure, heat flux and the aggregation time (AT) of nanoparticles (NPs) were studied. Numerically, the heat flux (HF) and the aggregation time of Ammonia -Cu nanofluid converged to 1411 W/m2 and 3.96 ns, respectively. The study showed that the maximum velocity and temperature decreased by increasing phi. Moreover, by increasing the phi to 5 %, the heat flux and aggregation time increase to 1553 W/m2 and 4.05 ns. By more increase of NPs up to 10 %, the heat flux and AT of samples decrease. By increasing NPs by 10 % in the base fluid, the aggregation process of NPs occurred in a shorter time. It reduces the thermal efficiency of simulated samples.