The Experts below are selected from a list of 324 Experts worldwide ranked by ideXlab platform
R Ansari - One of the best experts on this subject based on the ideXlab platform.
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A molecular dynamics study on the Buckling behavior of single-walled carbon nanotubes filled with gold nanowires
Journal of Molecular Modeling, 2020Co-Authors: S. Ajori, H. Parsapour, R AnsariAbstract:Molecular dynamics (MD) simulations are carried out to study the Buckling of pure gold nanowires (GNWs) and hybrid GNWs@single-walled carbon nanotubes (SWCNTs). The effects of geometrical parameters and endohedral filling of SWCNTs on the critical Buckling Force are taken into consideration. Two different types of GNWs, namely multi-shell and pentagonal GNWs, with various structures are considered. The results illustrate that the Buckling Force of the pure GNWs is less than those of the pure SWCNTs and hybrid structures. Also, GNWs possess higher Buckling Forces by increasing their cross-section area. It is observed that enclosing the GNWs by SWCNTs improves the mechanical behaviors of both CNTs and GNWs. In hybrid multi-shell GNWs@SWCNTs, by increasing the radius, the effect of encapsulation on the Buckling Force is more remarkable. It can be seen that the encapsulation of pentagonal GNWs has a slightly more effect on the Buckling behavior than the encapsulation of multi-shell GNWs. Moreover, it is found out that by increasing the length, the Buckling Force decreases.
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The effect of chitosan adsorption on the stability characteristics of single- and double-walled boron-nitride nanotubes under compressive Force using molecular dynamics simulations
Structural Chemistry, 2019Co-Authors: S. Ajori, Amir Ameri, R AnsariAbstract:In this study, the Buckling behavior of functionalized single- and double-walled boron-nitride nanotubes (SWBNNTs and DWBNNTs) with a monomer of chitosan using molecular dynamics (MD) simulations is explored. The effect of chemical adsorption of chitosan molecule on the critical Buckling Force and strain is investigated. The results show that the critical Buckling Force considerably increases as the chitosan is attached to the side wall of boron-nitride nanotube which is more considerable for larger radii of nanotube. Moreover, increasing the number of walls reduces the sensitivity of boron-nitride nanotube to the functionalization compared with similar SWBNNTs. Further, it is shown that critical Buckling of functionalized BNNTs increases by rising the weight percentage of chitosan. Considering the critical strain, it is observed that functionalization reduces the critical strain of functionalized BNNTs which is more pronounced in the case of SWBNNTs with bigger radii. Moreover, the Buckling mode shape of functionalized BNNTs is presented.
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On the Buckling behavior of functionalized single- and double-walled carbon nanotubes with azobenzene in the aqueous environment: a molecular dynamics study
Structural Chemistry, 2019Co-Authors: Amir Ameri, S. Ajori, R AnsariAbstract:In this study, the Buckling behavior of covalently functionalized single- and double-walled carbon nanotubes (SWCNTs and DWCNTs) with azobenzene is investigated in vacuum and aqueous environments using the classical molecular dynamics (MD) simulations. According to the results, functionalization increases the critical Buckling Force considerably, whereas it reduces the critical strain. It is observed that the critical Buckling Force of DWCNTs is not as sensitive as that of its constituent inner and outer functionalized SWCNTs. Also, it is observed that increasing the weight percentage of azobenzene results in increasing the critical Buckling Force of functionalized CNTs, whereas the critical strain decreases. Further, it is observed that critical Buckling Force of functionalized CNTs in the aqueous environment increases compared to that of functionalized CNTs in vacuum, while the critical strain does not change significantly.
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The mechanical properties and structural instability of single- and double-walled boron-nitride nanotubes functionalized with 2-methoxy-N,N-dimethylethanamine (MDE) using molecular dynamics simulations
The European Physical Journal D, 2019Co-Authors: S. Ajori, Amir Ameri, R AnsariAbstract:As an inorganic quasi-1D nanostructure with non-cytotoxic properties, boron-nitride nanotubes have been the center of interest to researchers due to their high potential biocompatible applications. Due to the importance of functionalization in designing novel devices, the mechanical properties and Buckling behavior of functionalized single- and double-walled boron-nitride nanotubes with 2-methoxy-N,N-dimethylethanamine (MDE) are investigated using molecular dynamics (MD) simulations. The calculated results demonstrate that Young’s moduli of BNNTs reduce, while critical Buckling Force and critical strain of BNNTs increase as MDE are attached to BNNTs. Moreover, it is observed that by increasing the MDE weight percentage, critical Buckling Force and critical strain of functionalized BNNTs reduce, unlike Young’s modulus. It is also observed that variations of the aforementioned parameters corresponding to DWBNNTs are less sensitive to MDE weight percentage compared to SWBNNTs and they lie between its inner and outer constituent functionalized SWBNNTs. Moreover, snapshots of Buckling mode shapes of functionalized BNNTs are presented.
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Structural stability and Buckling analysis of a series of carbon nanotorus using molecular dynamics simulations
Journal of Molecular Modeling, 2018Co-Authors: S. Ajori, R Ansari, R. Hassani, S. HaghighiAbstract:Based on molecular dynamics (MD) simulations, the Buckling analysis of a perfect carbon nanotorus is presented herein. First of all, the minimum length of single-walled carbon nanotubes (SWCNTs) with different radii is determined at which perfect toroidal CNTs can be formed without any ripple at the inner side of the rings. According to the results, by increasing the radius of SWCNT (r), the radius of its corresponding perfect nanotorus (R) increases. Also, for SWCNTs with various lengths, it is found that the Buckling Force and strain of related carbon nanotoruses increase by increasing R/r. In addition, as the perfect toroidal CNTs are arranged vertically in a column form in accordance with two different schemes, the effects of increasing the radius (R) and the number of carbon nanotoruses (the height of the column made by nanotoruses) on the Buckling Force and strain are investigated. Based on the results, as a fixed number of carbon nanotoruses with the same radius are arranged vertically in the column form, the Buckling Force and strain increase by increasing R/r. By contrast, increasing the height of the column made by carbon nanotoruses with similar radius leads to the reduction of Buckling Force and strain.
S. Ajori - One of the best experts on this subject based on the ideXlab platform.
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A molecular dynamics study on the Buckling behavior of single-walled carbon nanotubes filled with gold nanowires
Journal of Molecular Modeling, 2020Co-Authors: S. Ajori, H. Parsapour, R AnsariAbstract:Molecular dynamics (MD) simulations are carried out to study the Buckling of pure gold nanowires (GNWs) and hybrid GNWs@single-walled carbon nanotubes (SWCNTs). The effects of geometrical parameters and endohedral filling of SWCNTs on the critical Buckling Force are taken into consideration. Two different types of GNWs, namely multi-shell and pentagonal GNWs, with various structures are considered. The results illustrate that the Buckling Force of the pure GNWs is less than those of the pure SWCNTs and hybrid structures. Also, GNWs possess higher Buckling Forces by increasing their cross-section area. It is observed that enclosing the GNWs by SWCNTs improves the mechanical behaviors of both CNTs and GNWs. In hybrid multi-shell GNWs@SWCNTs, by increasing the radius, the effect of encapsulation on the Buckling Force is more remarkable. It can be seen that the encapsulation of pentagonal GNWs has a slightly more effect on the Buckling behavior than the encapsulation of multi-shell GNWs. Moreover, it is found out that by increasing the length, the Buckling Force decreases.
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The effect of chitosan adsorption on the stability characteristics of single- and double-walled boron-nitride nanotubes under compressive Force using molecular dynamics simulations
Structural Chemistry, 2019Co-Authors: S. Ajori, Amir Ameri, R AnsariAbstract:In this study, the Buckling behavior of functionalized single- and double-walled boron-nitride nanotubes (SWBNNTs and DWBNNTs) with a monomer of chitosan using molecular dynamics (MD) simulations is explored. The effect of chemical adsorption of chitosan molecule on the critical Buckling Force and strain is investigated. The results show that the critical Buckling Force considerably increases as the chitosan is attached to the side wall of boron-nitride nanotube which is more considerable for larger radii of nanotube. Moreover, increasing the number of walls reduces the sensitivity of boron-nitride nanotube to the functionalization compared with similar SWBNNTs. Further, it is shown that critical Buckling of functionalized BNNTs increases by rising the weight percentage of chitosan. Considering the critical strain, it is observed that functionalization reduces the critical strain of functionalized BNNTs which is more pronounced in the case of SWBNNTs with bigger radii. Moreover, the Buckling mode shape of functionalized BNNTs is presented.
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On the Buckling behavior of functionalized single- and double-walled carbon nanotubes with azobenzene in the aqueous environment: a molecular dynamics study
Structural Chemistry, 2019Co-Authors: Amir Ameri, S. Ajori, R AnsariAbstract:In this study, the Buckling behavior of covalently functionalized single- and double-walled carbon nanotubes (SWCNTs and DWCNTs) with azobenzene is investigated in vacuum and aqueous environments using the classical molecular dynamics (MD) simulations. According to the results, functionalization increases the critical Buckling Force considerably, whereas it reduces the critical strain. It is observed that the critical Buckling Force of DWCNTs is not as sensitive as that of its constituent inner and outer functionalized SWCNTs. Also, it is observed that increasing the weight percentage of azobenzene results in increasing the critical Buckling Force of functionalized CNTs, whereas the critical strain decreases. Further, it is observed that critical Buckling Force of functionalized CNTs in the aqueous environment increases compared to that of functionalized CNTs in vacuum, while the critical strain does not change significantly.
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The mechanical properties and structural instability of single- and double-walled boron-nitride nanotubes functionalized with 2-methoxy-N,N-dimethylethanamine (MDE) using molecular dynamics simulations
The European Physical Journal D, 2019Co-Authors: S. Ajori, Amir Ameri, R AnsariAbstract:As an inorganic quasi-1D nanostructure with non-cytotoxic properties, boron-nitride nanotubes have been the center of interest to researchers due to their high potential biocompatible applications. Due to the importance of functionalization in designing novel devices, the mechanical properties and Buckling behavior of functionalized single- and double-walled boron-nitride nanotubes with 2-methoxy-N,N-dimethylethanamine (MDE) are investigated using molecular dynamics (MD) simulations. The calculated results demonstrate that Young’s moduli of BNNTs reduce, while critical Buckling Force and critical strain of BNNTs increase as MDE are attached to BNNTs. Moreover, it is observed that by increasing the MDE weight percentage, critical Buckling Force and critical strain of functionalized BNNTs reduce, unlike Young’s modulus. It is also observed that variations of the aforementioned parameters corresponding to DWBNNTs are less sensitive to MDE weight percentage compared to SWBNNTs and they lie between its inner and outer constituent functionalized SWBNNTs. Moreover, snapshots of Buckling mode shapes of functionalized BNNTs are presented.
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Structural stability and Buckling analysis of a series of carbon nanotorus using molecular dynamics simulations
Journal of Molecular Modeling, 2018Co-Authors: S. Ajori, R Ansari, R. Hassani, S. HaghighiAbstract:Based on molecular dynamics (MD) simulations, the Buckling analysis of a perfect carbon nanotorus is presented herein. First of all, the minimum length of single-walled carbon nanotubes (SWCNTs) with different radii is determined at which perfect toroidal CNTs can be formed without any ripple at the inner side of the rings. According to the results, by increasing the radius of SWCNT (r), the radius of its corresponding perfect nanotorus (R) increases. Also, for SWCNTs with various lengths, it is found that the Buckling Force and strain of related carbon nanotoruses increase by increasing R/r. In addition, as the perfect toroidal CNTs are arranged vertically in a column form in accordance with two different schemes, the effects of increasing the radius (R) and the number of carbon nanotoruses (the height of the column made by nanotoruses) on the Buckling Force and strain are investigated. Based on the results, as a fixed number of carbon nanotoruses with the same radius are arranged vertically in the column form, the Buckling Force and strain increase by increasing R/r. By contrast, increasing the height of the column made by carbon nanotoruses with similar radius leads to the reduction of Buckling Force and strain.
Amir Ameri - One of the best experts on this subject based on the ideXlab platform.
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The effect of chitosan adsorption on the stability characteristics of single- and double-walled boron-nitride nanotubes under compressive Force using molecular dynamics simulations
Structural Chemistry, 2019Co-Authors: S. Ajori, Amir Ameri, R AnsariAbstract:In this study, the Buckling behavior of functionalized single- and double-walled boron-nitride nanotubes (SWBNNTs and DWBNNTs) with a monomer of chitosan using molecular dynamics (MD) simulations is explored. The effect of chemical adsorption of chitosan molecule on the critical Buckling Force and strain is investigated. The results show that the critical Buckling Force considerably increases as the chitosan is attached to the side wall of boron-nitride nanotube which is more considerable for larger radii of nanotube. Moreover, increasing the number of walls reduces the sensitivity of boron-nitride nanotube to the functionalization compared with similar SWBNNTs. Further, it is shown that critical Buckling of functionalized BNNTs increases by rising the weight percentage of chitosan. Considering the critical strain, it is observed that functionalization reduces the critical strain of functionalized BNNTs which is more pronounced in the case of SWBNNTs with bigger radii. Moreover, the Buckling mode shape of functionalized BNNTs is presented.
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On the Buckling behavior of functionalized single- and double-walled carbon nanotubes with azobenzene in the aqueous environment: a molecular dynamics study
Structural Chemistry, 2019Co-Authors: Amir Ameri, S. Ajori, R AnsariAbstract:In this study, the Buckling behavior of covalently functionalized single- and double-walled carbon nanotubes (SWCNTs and DWCNTs) with azobenzene is investigated in vacuum and aqueous environments using the classical molecular dynamics (MD) simulations. According to the results, functionalization increases the critical Buckling Force considerably, whereas it reduces the critical strain. It is observed that the critical Buckling Force of DWCNTs is not as sensitive as that of its constituent inner and outer functionalized SWCNTs. Also, it is observed that increasing the weight percentage of azobenzene results in increasing the critical Buckling Force of functionalized CNTs, whereas the critical strain decreases. Further, it is observed that critical Buckling Force of functionalized CNTs in the aqueous environment increases compared to that of functionalized CNTs in vacuum, while the critical strain does not change significantly.
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The mechanical properties and structural instability of single- and double-walled boron-nitride nanotubes functionalized with 2-methoxy-N,N-dimethylethanamine (MDE) using molecular dynamics simulations
The European Physical Journal D, 2019Co-Authors: S. Ajori, Amir Ameri, R AnsariAbstract:As an inorganic quasi-1D nanostructure with non-cytotoxic properties, boron-nitride nanotubes have been the center of interest to researchers due to their high potential biocompatible applications. Due to the importance of functionalization in designing novel devices, the mechanical properties and Buckling behavior of functionalized single- and double-walled boron-nitride nanotubes with 2-methoxy-N,N-dimethylethanamine (MDE) are investigated using molecular dynamics (MD) simulations. The calculated results demonstrate that Young’s moduli of BNNTs reduce, while critical Buckling Force and critical strain of BNNTs increase as MDE are attached to BNNTs. Moreover, it is observed that by increasing the MDE weight percentage, critical Buckling Force and critical strain of functionalized BNNTs reduce, unlike Young’s modulus. It is also observed that variations of the aforementioned parameters corresponding to DWBNNTs are less sensitive to MDE weight percentage compared to SWBNNTs and they lie between its inner and outer constituent functionalized SWBNNTs. Moreover, snapshots of Buckling mode shapes of functionalized BNNTs are presented.
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stability characteristics and structural properties of single and double walled boron nitride nanotubes under physical adsorption of flavin mononucleotide fmn in aqueous environment using molecular dynamics simulations
Applied Surface Science, 2016Co-Authors: R Ansari, S. Ajori, Amir AmeriAbstract:Abstract The non-cytotoxic properties of Boron-nitride nanotubes (BNNTs) and the ability of stable interaction with biomolecules make them so promising for biological applications. In this research, molecular dynamics (MD) simulations are performed to investigate the structural properties and stability characteristics of single- and double-walled BNNTs under physical adsorption of Flavin mononucleotide (FMN) in vacuum and aqueous environments. According to the simulation results, gyration radius increases by rising the weight percentage of FMN. Also, the results demonstrate that critical Buckling Force of functionalized BNNTs increases in vacuum. Moreover, it is observed that by increasing the weight percentage of FMN, critical Force of functionalized BNNTs rises. By contrast, critical strain reduces by functionalization of BNNTs in vacuum. Considering the aqueous environment, it is observed that gyration radius and critical Buckling Force of functionalized BNNTs increase more considerably than those of functionalized BNNTs in vacuum, whereas the critical strains approximately remain unchanged.
K.m. Liew - One of the best experts on this subject based on the ideXlab platform.
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Meshfree simulation of temperature effects on the mechanical behaviors of microtubules
Engineering Analysis with Boundary Elements, 2016Co-Authors: Ping Xiang, Lu-wen Zhang, K.m. LiewAbstract:Abstract The temperature-related mechanical behaviors of microtubules are investigated by way of the developed meshfree computational framework. An atomistic-continuum constitutive relationship is formulated for bridging-scale simulations of microtubules from polyatomic structure to continuum meshfree modeling. The establishment of a specific meshfree theory is based on high-order gradient continuity, by incorporating a higher-order Cauchy–Born rule. The influence of temperature on the critical Buckling Force and free vibration frequencies of microtubules is intensively studied. It is realized from the simulation results that temperature significantly affects the mechanical behaviors of microtubules. The critical Buckling Force and natural vibration frequencies of microtubules decrease with increases in temperature. A lower temperature will always result in a higher flexural rigidity, thus benefiting the mechanical strength of microtubules. In contrast, an elevated temperature will have negative impacts on microtubule stiffness. Microtubules with typical boundary restrictions subjected to different temperatures are included in the analysis. A series of simulation results on the critical Buckling Force and natural vibration frequencies of microtubules covering a wide range of microtubule lengths is presented for the purpose of the provision of engineering references.
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Effect of higher-order deformation gradients on Buckling of single-walled carbon nanotubes
Composite Structures, 2014Co-Authors: K.m. LiewAbstract:Abstract A single-walled carbon nanotube (SWCNT) is treated as a tubular Bernoulli–Euler beam and the higher-order deformation gradients are involved to establish a higher-order multiscale beam model. The higher-order Cauchy–Born rule is used to calculate the deformation of bond vectors in the representative cell and the strain energy density is equivalent to the energy per unit surface area, calculated from the Brenner potential. On the basis of the classical Bernoulli–Euler beam theory, the second-order deformation gradients with respect to the axial direction are also considered. The total strain energy is expressed as an integral equation, in which all parameters are obtained by calculating the constitutive response around the circumference. The physical meaning of these parameters is discussed in detail. The global Buckling of SWCNTs is studied, and the critical Buckling Force is obtained as the analytical formula for different boundary conditions. The critical Buckling Force is plotted against the tube chirality, tube radius and tube length, and it is discovered that the contribution of the higher-order terms rapidly becomes large when the tube radius or length is small enough.
Manabu Chikai - One of the best experts on this subject based on the ideXlab platform.
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Buckling Force Variability of Semmes–Weinstein Monofilaments in Successive Use Determined by Manual and Automated Operation
Sensors, 2019Co-Authors: Manabu ChikaiAbstract:(1) Objective: This study was conducted with the objective of characterizing the variability of a Force on a simulated skin surface using the Semmes–Weinstein monofilament test (SWMT). (2) Research Design and Methods: Two distinct experiments were performed to determine the effects of human hand motion variability on the monofilament Buckling Force, and to determine the monofilament’s mechanical properties using a positioning stage. (3) Results: In manual operation (by human hand motion), the Buckling Force over the ten compressions decreased by over 10%, and the human hand motion variations during the SWMT may have impacted the Buckling Force. When the SWMT was performed under manual control, the Buckling Force was closely correlated with the number of compressions. In automated operation (by positioning stage), the Buckling Force was affected not only by the number of compressions but also by both the velocity and the contact angle between the monofilament and the skin surface. (4) Conclusions: The Buckling Force decreased in ten successive compressions, independent of the hand motion. Hence, medical staff need to consider not only the operator’s hand motion but also the effect of repeated trials.
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Buckling Force variability of semmes weinstein monofilaments in successive use determined by manual and automated operation
Sensors, 2019Co-Authors: Manabu Chikai, Shuichi InoAbstract:(1) Objective: This study was conducted with the objective of characterizing the variability of a Force on a simulated skin surface using the Semmes–Weinstein monofilament test (SWMT). (2) Research Design and Methods: Two distinct experiments were performed to determine the effects of human hand motion variability on the monofilament Buckling Force, and to determine the monofilament’s mechanical properties using a positioning stage. (3) Results: In manual operation (by human hand motion), the Buckling Force over the ten compressions decreased by over 10%, and the human hand motion variations during the SWMT may have impacted the Buckling Force. When the SWMT was performed under manual control, the Buckling Force was closely correlated with the number of compressions. In automated operation (by positioning stage), the Buckling Force was affected not only by the number of compressions but also by both the velocity and the contact angle between the monofilament and the skin surface. (4) Conclusions: The Buckling Force decreased in ten successive compressions, independent of the hand motion. Hence, medical staff need to consider not only the operator’s hand motion but also the effect of repeated trials.
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EMBC - Evaluation of the variation in sensory test results using Semmes-Weinstein monofilaments
Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual Inte, 2015Co-Authors: Manabu Chikai, Emi Ozawa, Noriyo Takahashi, Kiyohiko Nunokawa, Shuichi InoAbstract:The purpose of this study is to examine the variability in sensory test of tactile results using Semmes-Weinstein monofilament (SWM). At present, several methods for measuring the tactile sensitivity are clinically used in diabetic peripheral neuropathy screening. One of these methods is a touch test that uses a device with nylon SWMs, i.e., SWMs embedded in a plastic handle. A small pushing Force is applied at the handle to bow the filaments. Because of its ease and simplicity, the SWM test is conducted at the patient's bedside in a hospital. However, previous studies have reported some problems with this test. Studies have shown variations in the measured data, and it is uncertain whether these variations are caused by mechanical properties of the nylon fiber or by the motion of the operator's hands. We carried out two experiments to examine the effect of (1) the variability caused by the human operator conducting the SWM test on the test results and (2) the number of compressions of the SWM on the test results. In experiment 1, we measured the velocity of the operator's hand motion and the Buckling Force of the SWMs. The results showed variability in the hand motion of the operator conducting the SWM tests. In experiment 2, we measured the Buckling Force of the SWMs under a controlled velocity. We compared the Buckling Force of the SWMs through a number of trials. These results showed that the Buckling Force gradually decreases as the number of test cycles increase. In conclusion, we find that the accuracy of the SWM tests is a factor of the number of test cycles. Additionally, manual training for standardizing skills of medical staff members needs to be developed. Furthermore, the characteristics of the SWMs deteriorated over time. In future work, we aimto find a solution to minimize the variability in the SWM test results and develop a new testing system that uses tactile sensibility for diabetic peripheral neuropathy screening.
