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This paper focuses on the operational modal analysis of the Karun IV dam, the highest concrete arch dam in Iran, based on the responses obtained from ambient vibration tests, which are carried out on the dam during 19 March 2014, and 3 March 2015 earthquake with an epicenter about 133 km northeast of the dam. The non-parametric FDD-Wavelet method is used for identification and extraction of modal parameters including natural frequencies, mode shapes and damping ratios. Nine and four natural frequencies are identified from ambient and seismic responses, respectively. Stabilization diagram and averaged coherence spectrum (ACS) are used to detect and eliminate spurious form true modes. Comparison of the results indicates that identification is performed properly and reliably.

Bilayer graphene nanoribbon (BGN) with tunable band gap which can be controlled by an external electric field is focused in our study. AB-stacked system with a stable structure is considered in a FET channel. Based on the assumed structure carrier density effect on charge mobility has been reported at different temperatures. Carrier mobility model is explained based on quantum confinement effect which indicates that carriers behave like traveling wave only in channel direction. Their behavior in other two directions can be approximated by standing wave as well. We prove that carrier mobility in BGNs is a function of temperature and carrier density which illustrate good agreement with experimental data.

Silicon Nanowire Fin Field Effect Transistor (SiNWFinFET) is a unique transistor in which all of its gates wrap the insulator and inner layer of silicon. In this paper, the effective channel length effect on Silicon Nanowire FinFET is presented, based on the quantum confinement effects. The analytical model of current voltage incorporated with the effects of channel length modulation, is developed, and verified with published experimental data. The results show that by considering the channel length modulation effect, the SiNWFinFET performance is improved. Results obtained demonstrate the importance of considering the effective channel length in SiNWFinFET devices. Carrier mobility improvement based on the current-voltage graph is also reported.

We present trilayer graphene nanoribbon carrier statistics in the degenerate and the nondegenerate limits. Within zero to 3k(B)T from the conduction or valence band edgers high concentrations of carriers sensitively depend on a normalized Fermi energy which is independent of temperature. The effect of different stacking orders of graphene multilayers on the electric field induced band gap is studied. The gap for trilayer graphene with the ABC stacking is much larger than the corresponding gap for the ABA trilayer. The gap for the different types of stacking is much larger as compared to the case of Bernal stacking. A non- monotonic dependence of the true energy gap in trilayer graphene on the charge density is investigated along with the electronic low-energy band structure of ABC stacked multilayer graphene. The band structure of trilayer graphene systems in the presence of a perpendicular electric field is obtained using a tight-binding approach.

In this paper, our focus is on ABA trilayer graphene nanoribbon (TGN), in which the middle layer is horizontally shifted from the top and bottom layers. The conductance model of TGN as a FET channel is presented based on Landauer formula. Besides the good reported agreement with experimental study lending support to our model, the presented model demonstrates that minimum conductivity increases dramatically by temperature. It also draws parallels between TGN and bilayer graphene nanoribbon, in which similar thermal behavior is observed. Maxwell-Boltzmann approximation is employed to form the conductance of TGN near the neutrality point. Analytical model in degenerate regime in comparison with reported data proves that TGN-based transistor will operate in degenerate regime like what we expect in conventional semiconductors. Moreover, our model confirms that in similar condition, the conductivity of TGN is less than bilayer graphene nanoribbon as reported in some experiments.

Silicon based technology has received its technical limitation because of its unstable structure at nano-level. Carbon nanotube as an alternative material has attracted significant scientific efforts. Fabrication of Schottky diode using carbon nanotube is an open area of research to overcome this limit. In this study, we model the current of CNT Schottky diode under applied voltage. Parabolic band approximation on CNT induces Fermi-Dirac integral of order zero on its current voltage which is similar to the conventional one dimensional material. This model shows that its current has a weak dependence on temperature corresponding to the small applied voltage. It is quite different in high bias voltages which are independent of temperature. Based on this model, incremental effect of the carbon nanotube diameter has been explained by increasing the current with the applied voltage. The model presented in this paper is in good agreement with the reported data from experiments. This device can be used in the integrated circuit miniaturization.

Graphene has received significant attention due to its excellent transport properties. Bilayer Graphene Nanoribbon (BGN), double Bernal stacked honeycomb sheets of carbon which have quadratic dispersion relations instead of single layer Graphene Nanoribbon (GNR) by linear dispersion, provides an interesting area of research activity. In this paper, we show that isolating properties appears in the limit of external applied voltage in BGNs. The gap between conduction and valance band which is opened by an applied electric field is strongly varied by the value of the external voltage. The band gap is opened for Vext = 0 Vextmax to where the conduction and valance band meet each other and overlap through the conduction and valance band. In this boundary condition, BGNs are expected to behave as an insulator. In contrast, beyond this boundary condition it is estimated to be semi-metallic. Also we showed changing the value of interlayer hopping strongly affected the maximum band gap and it creates a wider possible external electric field which opens the band gap in BGNs.

In this work, fundamental results on carrier statistics in a carbon nanotube treated as a one-dimensional material are presented. Also the effect of degeneracy on the capacitance of the carbon nanotube channel in a carbon nanotube field effect transistor is discussed. A quantum capacitance as well as a classical capacitance is revealed. Furthermore it is shown that for low gate voltage, the total capacitance is equivalent to the classical capacitance but for high gate voltage it is equivalent to the quantum capacitance. We predict that in the nondegenerate regime, the total capacitance is equivalent to the classical capacitance and that the quantum capacitance can be neglected, whereas only quantum capacitance needs to be taken into account in the calculation of the total capacitance in the degenerate regime.

This paper focuses on the electronic transport properties of bilayer Graphene nanoribbons (BGNRs). The electronic transport of two dimensional AB stacked BGNRs with widths less than 10 nm is investigated. Due to the small width, the BGNR can be assumed to operate as a one dimensional device. A mathematical model of carrier concentration in BGNRs in the nondegenerate regime is presented. The model shows that in this regime the carrier statistics of BGNRs can be expressed by an exponential function of the normalized Fermi energy eta, which is particularly useful in the lower carrier concentration regions.

Ballistic conductance of Bilayer Graphene Nanoribbons (BGNs) is concerned in this paper. Mathematical model and numerical solution of BGNs ballistic conductance is introduced as well as its analytical model in the degeneracy limit. Our method indicates that near the neutrality point the non-degenerate approximation can be properly used. In contrast, out of this boundary condition it is estimated to work in the degenerate regime. Moreover, it confirms that BGN conductance is temperature dependence near the neutrality point also minimum conductance is depended on temperature which increases by increasing temperature but beyond the neutrality point conductance is independent of temperature. Presented model shows good agreement by published experimental data.

Interconnect wires are major technology components of modern high-speed integrated circuits. To overcome the latter's degradation caused by increasing miniaturization, there is an urgent need to look for alternative technologies. Since carbon based materials generate promising results, this paper focuses on describing the electrical properties of carbon based materials, in particular the use of graphene nanoribbon (GNR) as well as trilayer graphene nanoribbon (TGN) as next generation interconnects: since the conductance of TGN is less affected by external fields compared to GNR, it forms an improved choice for on-chip interconnects. The conductance model of TGN is derived and discussed in detail.