Gotowe bibliografie tematyczne / ZIGZAG TYPE NANOTUBE

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Gotowa bibliografia na temat „ZIGZAG TYPE NANOTUBE”

Autor: Grafiati

Data publikacji: 11 września 2023

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Artykuły w czasopismach na temat "ZIGZAG TYPE NANOTUBE"

Дадашян, Л. Х., Р. Р. Трофимов, Н. Н. Конобеева i М. Б. Белоненко. "Предельно короткие импульсы в оптически анизотропной среде, содержащей углеродные нанотрубки с металлической проводимостью". Оптика и спектроскопия 130, nr 12 (2022): 1861. http://dx.doi.org/10.21883/os.2022.12.54092.49-22.

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In this work, we study the interaction of extremely short pulses with a nonlinear anisotropic optical medium with carbon nanotubes (armchair and zigzag type) with metallic conductivity. The dependence of the pulse shape, width, and intensity on the nanotube chirality indices is analyzed. The most appropriate type of carbon nanotubes is substantiated for providing localized propagation of an electromagnetic field in a medium with anisotropic properties.

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Dadashyan L.H., Trofimov R.R., Konobeeva N.N. i Belonenko M.B. "Extremely short pulses in an anisotropic optical medium containing carbon nanotubes with metal conduction". Optics and Spectroscopy 130, nr 12 (2022): 1587. http://dx.doi.org/10.21883/eos.2022.12.55246.49-22.

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Malysheva, Lyuba. "Effects of chirality in the electron transmission through step-like potential in zigzag, armchair, and (2m,m) carbon nanotubes". Low Temperature Physics 48, nr 11 (listopad 2022): 907–13. http://dx.doi.org/10.1063/10.0014581.

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We report the one-electron spectrum and eigenstates of infinite achiral and chiral (2 m, m) carbon nanotubes found by using the analytic solution to the Schrödinger equation for the tight-binding Huckel-type Hamiltonian. With the help of matching the wave functions on the interfaces between the regions, where electrons have different site energies, we find and compare the transmission coefficients for zigzag, armchair and chiral nanotubes subjected to the action of an applied step-like potential. The correspondence between the nanotube band structure and the energy dependence of the transmission coefficient is demonstrated. It is shown that the (2 m, m) nanotubes with a medium chiral angle reveal intermediate transport properties as compared with the achiral armchair, and zigzag nanotubes.

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Tomilin O. B., Rodionova E. V., Rodin E.A., Poklonski N. A., Anikeyev I. I. i Ratkevich S. V. "Dependence of the energy of emission molecular orbitals in short open carbon nanotubes on the electric field". Physics of the Solid State 64, nr 3 (2022): 347. http://dx.doi.org/10.21883/pss.2022.03.53191.201.

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On the examples of short open carbon nanotubes of armchair type (n,n), for n=3, 4, and zigzag (n,0), for n=5, 6, 7, the influence of the magnitude and direction of the external constant electric field vector on their field emission properties was studied. It is shown that the deviation of the field vector from the nanotube axis leads to an increase in the field strength to generate electron field emission. Emission orbitals in carbon nanotubes (n,n) found as a result of a new type of conjugation of p-electrons in cylindrical conjugated systems are more sensitive to a change in the direction of the electric field vector compared to emission orbitals in nanotubes (n,0). When the electric field vector deviates from the nanotube axis, the emission orbitals of carbon nanotubes change the less, the larger the nanotube diameter. Keywords: short open carbon nanotubes, field emission, conjugation of p-electrons, emission molecular orbital.

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Ghorbanpour Arani, A., M. Mosayyebi, F. Kolahdouzan, R. Kolahchi i M. Jamali. "Refined zigzag theory for vibration analysis of viscoelastic functionally graded carbon nanotube reinforced composite microplates integrated with piezoelectric layers". Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering 231, nr 13 (14.09.2016): 2464–78. http://dx.doi.org/10.1177/0954410016667150.

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Damped free vibration of carbon nanotube reinforced composite microplate bounded with piezoelectric sensor and actuator layers are investigated in this study. For the mathematical modeling of sandwich structure, the refined zigzag theory is applied. In addition, to present a realistic model, the material properties of system are supposed as viscoelastic based on Kelvin–Voigt model. Distributions of single-walled carbon nanotubes along the thickness direction of the viscoelastic carbon nanotube reinforced composite microplate are considered as four types of functionally graded distribution patterns. The viscoelastic functionally graded carbon nanotube reinforced composite microplate subjected to electromagnetic field is embedded in an orthotropic visco-Pasternak foundation. Hamilton’s principle is employed to establish the equations of motion. In order to calculate the frequency and damping ratio of sandwich plate, boundary condition of plate is assumed as simply-supported and an exact solution is used. The effects of some significant parameters such as damping coefficient of viscoelastic plates, volume fraction of carbon nanotubes, different types of functionally graded distributions of carbon nanotubes, magnetic field, and external voltage on the damped free vibration of system are investigated. Results clarify that considering viscoelastic property for system to achieve accurate results is essential. Furthermore, the effects of volume fraction and distribution type of carbon nanotubes are remarkable on the vibration of sandwich plate. In addition, electric and magnetic fields are considerable parameters to control the behavior of viscoelastic carbon nanotube reinforced composite microplate. It is hoped that the results of this study could be applied in design of nano/micromechanical sensor and actuator systems.

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Okuyama, Rin, Wataru Izumida i Mikio Eto. "Topology in single-wall carbon nanotube of zigzag and armchair type". Journal of Physics: Conference Series 969 (marzec 2018): 012137. http://dx.doi.org/10.1088/1742-6596/969/1/012137.

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Kusunoki, Michiko, Toshiyuki Suzuki i Chizuru Honjo. "Selective Growth of Zigzag-type Carbon Nanotube by Surface Decomposition of SiC". Materia Japan 42, nr 12 (2003): 900. http://dx.doi.org/10.2320/materia.42.900.

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Zhou, Xin, Haifang Cai, Chunwei Hu, Jiao Shi, Zongli Li i Kun Cai. "Analogous Diamondene Nanotube Structure Prediction Based on Molecular Dynamics and First-Principle Calculations". Nanomaterials 10, nr 5 (28.04.2020): 846. http://dx.doi.org/10.3390/nano10050846.

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A concentric twin tube (CTT) can be built by placing a carbon nanotube (CNT) in another identical CNT. Different from diamondene nanotubes, a stable CTT has no inter-shell covalent bond. As a prestressed double-walled nanotube, CTT has a lower structural stability at a finite temperature. According to the molecular dynamics and first-principle calculations, (a) CTTs have three types of relaxed configurations. In a type III CTT, the inner tube buckles to produce a V-shaped cross-section, and the outer tube may be convex or concave. (b) The minimal radii of relaxed zigzag and armchair CTTs with concave outer tubes were found. (c) After relaxation, the circumferences and areas of the two tubes in a type III CTT are different from those of the corresponding ideal CNT. The area change rate (A-CR) and circumference change rate (C-CR) of the outer tube are the first-order Gaussian function of the radius of the ideal CNT (which forms the CTT), and tends to be 73.3% of A-CR or 95.3% of C-CR, respectively. For the inner tube of a CTT, the A-CR is between 29.3% and 37.0%, and the C-CR is close to 95.8%. (d) The temperature slightly influences the findings given above.

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Zhao, Yipeng, Huamin Hu i Gang Ouyang. "Optimizing the photovoltaic effect in one-dimensional single-wall carbon nanotube @ MoS₂ van der Waals heteronanotubes". Journal of Applied Physics 132, nr 23 (21.12.2022): 234304. http://dx.doi.org/10.1063/5.0124128.

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One-dimensional single-wall carbon nanotube (1D-SWCNT)@MoS2 van der Waals (vdW) heteronanotubes (HNTs) have inherited extensive attention due to their fascinating properties and increasing mature methods. However, the curvature and chirality dependence of photovoltaic properties in such kind of 1D systems remain unclear. In our work, we explore the electronic and photoelectric properties of 1D-SWCNT@MoS2 vdW HNTs based on the atomic-bond-relaxation approach and the modified detailed balance principle by quantization of band offset and carrier transport behaviors. We find that the optimized power conversion efficiency (PCE) of zigzag-SWCNT@ zigzag-MoS2 HNTs is ∼5.3% at the diameter of 3.1 nm, while that of zigzag-SWCNT@ armchair-MoS2 HNTs is ∼4.9% at 3.3 nm. Moreover, the PCE can be enhanced further by intercalating h-BN layers at the interface of 1D-vdW HNTs. Our results suggest that 1D-SWCNT@MoS2 HNTs can be served as promising building blocks for the new type of photovoltaic devices.

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Sekiguchi, Ryuta, Kei Takahashi, Jun Kawakami, Atsushi Sakai, Hiroshi Ikeda, Aya Ishikawa, Kazuchika Ohta i Shunji Ito. "Preparation of a Cyclic Polyphenylene Array for a Zigzag-Type Carbon Nanotube Segment". Journal of Organic Chemistry 80, nr 10 (6.05.2015): 5092–110. http://dx.doi.org/10.1021/acs.joc.5b00485.

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Rozprawy doktorskie na temat "ZIGZAG TYPE NANOTUBE"

SHARMA, ANAND. "FIELD EMISSION OF ELECTRONS FROM HEMISPHERICAL CONDUCTING CARBON NANOTUBE TIP INCLUDING THE EFFECT OF IMAGE FORCE". Thesis, 2016. http://dspace.dtu.ac.in:8080/jspui/handle/repository/14632.

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ABSTRACT The present work examines the field emission from Conducting Hemispherical Carbon Nanotune (CNT) tip including the Effect of Image Force. An expression for electrostatic potential for a Hemispherical CNT tip at a distance from the centre of CNT has been derived. Using the time-independent Schrodinger equation corresponding expressions for transmission coefficient and field emission current density have been derived for the Hemispherical Conducting Carbon Nanotubes. The numerical calculations of potential, transmission coefficient and the current density function have been calculated for a typical set of carbon nanotube parameters. From the expression of potential energy we found that the potential energy for the hemispherical CNT tip first increases and then decreases with the radial distance. The transmission coefficient increases with the normalized radial energy. And the current density function also increases with the normalized Fermi energy. An important outcome of the present work is that both transmission coefficient and field emission current density function decreases as the hemispherical CNT tip radius increases.

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Lin, Eugene, i 林群欽. "1. Theoretical study on the shortest armchair-, zigzag-, and mixing-type single-wall carbon nanotubes2. Quantum-size Effect on 67Zn-NMR Measurements of ZnS Nanoparticles". Thesis, 2008. http://ndltd.ncl.edu.tw/handle/04301817375690228583.

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碩士
國立中興大學
化學系所
96
Various carbon nanotubes (CNTs) were studied theoretically with reactivity and aromaticity indices in density functional theory (DFT) level. Mixing-types CNTs provide the possibilities to form different electronic properties and stabilities with tuning the components of armchair or zigzag CNTs. Moreover, the local aromaticities show the distinct electronic properties of mixing-type CNTs or Möbius-type CNTs implying the further modifications on specific sites. An unusual NMR phenomenon is present to demonstrate the quantum-size effect of ZnS clusters with its length scale properly estimated within 4 nm from the 67Zn-NMR measurements. Strong quadrupole interaction induced from the quantum-size effect is proposed to explain this phenomenon. A simple calculation of the electric field gradient by direct summation over all lattice points was performed to demonstrate this size effect, and the result is in good agreement with the experimental observation.

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Streszczenia konferencji na temat "ZIGZAG TYPE NANOTUBE"

Sun, Xuekun, i Youqi Wang. "Mechanical Properties of Carbon Nanotubes". W ASME 2002 International Mechanical Engineering Congress and Exposition. ASMEDC, 2002. http://dx.doi.org/10.1115/imece2002-39484.

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Nano-scale finite element approach was used to predict the mechanical properties of carbon nanotubes. The unit-cell isolation scheme was same as that from Eric Seather [1], and nothing was assumed to exist inside any nanotube. Arm-chair, zigzag and chiral type of nanotubes with different radii were discussed in detail. The longitudinal modulus of nanotubes Ez was found to decrease with increasing nanotube radius, but to be independent of nanotube helicity. The modulus was not over 0.5 TPa for any case. Meanwhile, Poisson’s ratio νzθ was also predicted.

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Patel, Ajay M., i Anand Y. Joshi. "Vibration Analysis of Defective Double Walled Carbon Nanotube Based Nano Resonators". W ASME 2014 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/imece2014-36454.

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The dynamic analysis of zigzag and armchair double walled carbon nanotubes (DWCNTs) with different boundary condition has been performed using atomistic finite element method. The double walled carbon nanotube is modeled considering it as a space frame structure similar to a three dimensional beam. The elastic properties of beam element are calculated by considering mechanical characteristics of covalent bonds between the carbon atoms in the hexagonal lattice. Spring elements are used to describe the interlayer interactions between the inner and outer tubes caused due to the van der Waals forces. The mass of each beam element is assumed as point mass at nodes coinciding with carbon atoms at inner and outer wall of DWCNT. It has been reported that multiple atomic vacancies are formed during the manufacturing process in DWCNT which tend to migrate leading to a change in the mechanical characteristics. Simulations have been carried out to visualize the behaviour of such defective DWCNTs subjected to different boundary conditions. The results clearly state that the dynamic characteristics are greatly influence by defects like vacancies in it. Comparison with the other experimental and theoretical studies exhibits good association which suggests that defective DWCNTs can further be explored for mass sensing. This investigation is helpful in applications involving ultra-high frequency nano resonators which contain one or other type of manufacturing defects in it.

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Ohnishi, Masato, Yusuke Suzuki, Yusuke Ohashi, Ken Suzuki i Hideo Miura. "Change of the Electronic Conductivity of Carbon Nanotube and Graphene Sheets Caused by a Three-Dimensional Strain Field". W ASME 2011 Pacific Rim Technical Conference and Exhibition on Packaging and Integration of Electronic and Photonic Systems. ASMEDC, 2011. http://dx.doi.org/10.1115/ipack2011-52057.

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In this study, the change of the resistivity of carbon nanotubes and graphene sheets under strain was analyzed by applying a quantum chemical molecular dynamics analysis and the first principle calculation. Various combinations of double-walled carbon nanotube structures were modeled for the analysis. The change of the band structure was calculated by changing the amplitude of the applied strain. It was found in some cases that the band structure changes drastically from metallic band structure to semiconductive one, and this result clearly indicated that the electronic conductivity of the MWCNT decreased significantly in a three-dimensional strain field. It was also found that there is a critical strain at which the electronic band structure changes from metallic to semiconductive and vice versa. This result indicated that the metallic CNT changes a semiconductive CNT depending on the applied strain field. The effect of the diameter of the zigzag type CNT on the critical strain of buckling deformation was analyzed under uni-axial strain. In this analysis, the aspect ratio of each structure was fixed at 10. It was found that the critical strain decreased monotonically with the decrease of the diameter. This was because that the flexural rigidity of a cylinder decreased with the decrease of its diameter when the thickness of the wall of the cylinder was fixed. It was found that the critical strain decreased drastically from about 5% to 0.5% when the aspect ratio was changed from 10 to 30. Since the typical aspect ratio of CNTs often exceeds 1000, most CNTs should show buckling deformation when an axial compressive strain is applied to the CNTs. Finally, the shape of a six-membered ring of the CNT was found to be the dominant factor that determines the electronic band structure of a CNT. The change of the band structure of a grapheme sheet was analyzed by applying the abinitio calculation based on density functional theory. It was found that the fluctuation of the atomic distance among the six-membered ring is the most dominant factor of the electronic band structure. When the fluctuation exceeded about 10%, band gap appeared in the deformed six-membered ring, and thus, the electronic conductivity of the grapheme sheet change from metallic one to semiconductive one. It is therefore, possible to predict the change of the electronic conductivity of a CNT by considering the local shape of a six-membered ring in the deformed CNT.

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Zuberi, Muhammad Jibran Shahzad, i Volkan Esat. "Estimating the Effect of Chirality and Size on the Mechanical Properties of Carbon Nanotubes Through Finite Element Modelling". W ASME 2014 12th Biennial Conference on Engineering Systems Design and Analysis. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/esda2014-20156.

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Carbon nanotubes (CNTs) are considered to be one of the contemporary materials exhibiting superior mechanical, thermal and electrical properties. A new generation state-of-the-art composite material, carbon nanotube reinforced polymer (CNTRP), utilizes carbon nanotubes as the reinforcing fibre element. CNTRPs are highly promising composite materials possessing the potential to be used in various areas such as automotive, aerospace, defence, and energy sectors. The CNTRP composite owes its frontline mechanical material properties mainly to the improvement provided by the CNT filler. There are challenging issues regarding CNTRPs such as determination of material properties, and effect of chirality and size on the mechanical material properties of carbon nanotube fibres, which warrant development of computational models. Along with the difficulties associated with experimentation on CNTs, there is paucity in the literature on the effects of chirality and size on the mechanical properties of CNTs. Insight into the aforementioned issues may be brought through computational modelling time- and cost-effectively when compared to experimentation. This study aims to investigate the effect of chirality and size of single-walled carbon nanotubes (SWNTs) on its mechanical material properties so that their contribution to the mechanical properties of CNTRP composite may be understood more clearly. Nonlinear finite element models based on molecular mechanics using various element types substituting C-C bond are generated to develop zigzag, armchair and chiral SWNTs over a range of diameters. The predictions collected from simulations are compared to the experimental and computational studies available in the literature.

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Ohnishi, Masato, Katsuya Ohsaki, Yusuke Suzuki, Ken Suzuki i Hideo Miura. "Nanostructure Dependence of the Electronic Conductivity of Carbon Nanotubes and Graphene Sheets". W ASME 2010 International Mechanical Engineering Congress and Exposition. ASMEDC, 2010. http://dx.doi.org/10.1115/imece2010-37277.

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In this study, the change of the resistivity of the CNT-dispersed resin was analyzed by applying a quantum chemical molecular dynamics and the first principle calculation. Various combinations of double-walled carbon nanotube structures were modeled for the analysis. The change of the band structure was calculated by changing the amplitude of the applied strain. It was found in some cases that the band structure changes drastically from a metallic structure to a semiconductive structure, and this result clearly indicated that the electronic conductivity of this MWCNT decreased significantly under tensile strain. It was also found that further application of the strain made a band gap in the band structure. This result indicated that the metallic CNT changes a semiconductive CNT due to the applied strain. The effect of the diameter of the zigzag type CNT on the critical strain of buckling deformation was analyzed under a uni-axial strain. In this analysis, the aspect ratio of each structure was fixed at 10. It was found that the critical strain decreased monotonically with the increase of the diameter. This was because that the flexural rigidity of a cylinder decreased with the increase of its diameter when the thickness of the wall of the cylinder is fixed. It was found that the critical strain decreased drastically from about 5% to 0.5% when the aspect ratio was changed from 10 to 30. Since the typical aspect ratio of CNTs often exceeds 1000, most CNTs show buckling deformation when an axial compressive strain was applied to the CNTs. Finally, the shape of six-membered ring of the CNT was found to be the dominant factor that determines the electronic band structure of a CNT. Next, the change of the band structure of a graphene sheet was analyzed by applying the abinitio calculation (Density functional theory). It was found that the fluctuation of the atomic distance among the six-membered ring is the most dominant factor of the electronic band structure. When the fluctuation exceeded about 10%, band gap appeared in the deformed six-membered ring, and thus, the electronic conductivity of the graphene sheet changes from metallic one to semiconductive one. It is therefore, possible to predict the change of the electronic conductivity of a CNT by considering the local shape of a six-membered ring in the deformed CNT.

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Thapa, Arun B., i Alexey N. Volkov. "Atomistic Simulations of Mechanical Properties of Circular and Collapsed Carbon Nanotubes With Covalent Cross-Links". W ASME 2018 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/imece2018-88172.

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Stretching properties of single-walled carbon nanotubes (CNTs) of large diameters are studied in atomistic simulations. The simulations are performed based on the AIREBO empirical interatomic potential for three types of CNTs: Nanotubes with circular cross section, permanently collapsed nanotubes with “dog-bone”-shaped cross sections, and collapsed nanotubes with intra-tube covalent cross-links. In the last case, the cross-links between parallel quasi-planar parts of the nanotube wall are assumed to be formed by interstitial carbon atoms. The calculated equilibrium shape of collapsed nanotubes and the threshold diameter for permanently collapsed CNTs are found to agree with existing literature data. Elastic modulus, maximum stress, and strain at failure are calculated for zigzag CNTs with the equivalent diameter up to 6.27 nm in the temperature range from 5 K to 500 K. The simulations show that these mechanical properties only moderately depend on the diameter of circular CNTs. For collapsed CNTs with and without cross-links, the mechanical properties are practically independent of the CNT diameter for nanotubes with diameters larger than 4.7 nm. The elastic modulus and maximum stress of collapsed nanotubes are found to be smaller than those for the equivalent circular CNTs. The intra-tube cross-linking increases the elastic modulus and strength of collapsed CNTs in up to 50% compared to corresponding collapsed CNTs without cross-links, but reduces the breaking strain. Thermal softening of CNTs with increasing temperature in the range from 100 K to 500 K induces a decrease in the elastic modulus and maximum stress in about 12–33%.

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Song, X., Q. Ge i S. C. Yen. "Elastic Properties of Single-Walled Carbon Nanotubes in Axial and Transverse Directions: A First Principles Study". W ASME 4th Integrated Nanosystems Conference. ASMEDC, 2005. http://dx.doi.org/10.1115/nano2005-87047.

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A first principles approach has been employed to study the elastic properties of ten zigzag and seven armchair types of single-walled carbon nanotubes (SWNTs) with the diameter varied from 0.551 to 1.358 nm. The linear elastic behavior of the SWNTs when subject to small deformation is studied by four virtual mechanical experiments: uniaxial strain, uniaxial stress, in-plane pure shear, and in-plane bi-axial tension tests. Assuming that a SWNT be transversely isotropic, a strain energy approach is used to calculate the Young’s moduli in axial and transverse directions, major Posson’s ratio, plain strain bulk, and in-plane shear moduli of the carbon nanotubes. It is found that the elastic constants are insensitive to the tube size, but show a slight dependence upon the helicity. However, the differences in the elastic moduli between zigzag and armchair nanotubes are within 10%.

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Askari, Davood, i Mehrdad N. Ghasemi Nejhad. "Mechanical Properties Predictions and Responses of Defected Carbon Nanotubes Subjected to Axial Loading". W ASME 2006 International Mechanical Engineering Congress and Exposition. ASMEDC, 2006. http://dx.doi.org/10.1115/imece2006-13246.

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The increasing demand for fabrication of smaller structural and electronic devices with higher performance such as NEMS/MEMS has created great interest and motivation for extensive research and investigations in nanotechnology and its applications. Unique mechanical, thermal, and electrical properties of the one dimensional carbon nanotubes (CNTs) structures project CNTs as an excellent candidate for the future NEMS/MEMS devices. However, carbon nanotubes do not always exist in their perfect hexagonal lattice structures. Defects may appear during the purification stages or chemical treatments as it might even be desirable for functionalization of carbon nanotubes. On the other hand, defects can greatly influence the mechanical performance of carbon nanotubes in structural applications where they are subjected to external mechanical loads. Therefore, a detailed investigation of the effects of defects on mechanical performance of carbon nanotubes is needed to explain the behavior of such structures. Here in this work, finite element method (FEM) is employed to numerically investigate the responses of defected carbon nanotubes to external loads. Single-walled carbon nanotubes (SWCNTs) with different structural configurations, i.e., zigzag, armchair, and chiral, with different types of vacancy defects are modeled and their effective mechanical properties are investigated. Finally, results are discussed and compared with those obtained for SWCNTs without defects.

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