Employing GDQ method for exploring undamped vibrational performance of CNT-reinforced porous coupled curved beam

Moein A. Ghandehari,Amir R. Masoodi Techno-Press 2023 Advances in nano research Vol.15 No.6

Coupled porous curved beams, due to their low weight and high flexibility, have many applications in engineering. This study investigates the vibration behavior of coupled porous curved beams in different boundary conditions. The system consists of two curved beams connected by a mid-layer of elastic springs. These beams are made of various materials, such as homogenous steel foam, and composite materials with PMMA (polymethyl methacrylate) and SWCNT (single-walled carbon nanotube) used as the matrix and nanofillers, respectively. To obtain equivalent material properties, the role of mixture (RoM) was employed, followed by the implementation of the porosity function. The system's governing equations were obtained by employing FSDT and Hamilton's law. To investigate thermal vibration, temperature was implemented as a load in the governing equations. The GDQ method was used to solve these equations. To demonstrate the applicability of the GDQ method in calculating the frequencies of the system and the correctness of the developed program, a validation study was conducted. After validation, numerous examples were presented to investigate the behavior of single and coupled curved beams in various material properties and boundary conditions. The results indicate that the frequencies of the curved beams and the system depend highly on the amount of porosity (n) and the distribution pattern. The system frequencies decreased with an increase in the porosity coefficient. The stiffness of the springs had no effect on the first mode frequency but increased frequencies of other modes in a specific range. The frequencies of the system decreased with an increase in environmental temperature.

Optimized QCA SRAM cell and array in nanoscale based on multiplexer with energy and cost analysis

Moein Kianpour,Reza Sabbaghi-Nadooshan,Majid Mohammadi,Behzad Ebrahimi Techno-Press 2023 Advances in nano research Vol.15 No.6

Quantum-dot cellular automata (QCA) has shown great potential in the nanoscale regime as a replacement for CMOS technology. This work presents a specific approach to static random-access memory (SRAM) cell based on 2:1 multiplexer, 4-bit SRAM array, and 32-bit SRAM array in QCA. By utilizing the proposed SRAM array, a single-layer 16×32-bit SRAM with the read/write capability is presented using an optimized signal distribution network (SDN) crossover technique. In the present study, an extremely-optimized 2:1 multiplexer is proposed, which is used to implement an extremely-optimized SRAM cell. The results of simulation show the superiority of the proposed 2:1 multiplexer and SRAM cell. This study also provides a more efficient and accurate method for calculating QCA costs. The proposed extremely-optimized SRAM cell and SRAM arrays are advantageous in terms of complexity, delay, area, and QCA cost parameters in comparison with previous designs in QCA, CMOS, and FinFET technologies. Moreover, compared to previous designs in QCA and FinFET technologies, the proposed structure saves total energy consisting of overall energy consumption, switching energy dissipation, and leakage energy dissipation. The energy and structural analyses of the proposed scheme are performed in QCAPro and QCADesigner 2.0.3 tools. According to the simulation results and comparison with previous high-quality studies based on QCA and FinFET design approaches, the proposed SRAM reduces the overall energy consumption by 25%, occupies 33% smaller area, and requires 15% fewer cells. Moreover, the QCA cost is reduced by 35% compared to outstanding designs in the literature.

Estimation of various amounts of kaolinite on concrete alkali-silica reactions using different machine learning methods

Moein Aflatoonian,Ramin Tabatabaei Mirhosseinia 국제구조공학회 2022 Structural Engineering and Mechanics, An Int'l Jou Vol.83 No.1

In this paper, the impact of a vernacular pozzolanic kaolinite mine on concrete alkali-silica reaction and strength has been evaluated. For making the samples, kaolinite powder with various levels has been used in the quality specification test of aggregates based on the ASTM C1260 standard in order to investigate the effect of kaolinite particles on reducing the reaction of the mortar bars. The compressive strength, X-Ray Diffraction (XRD) and Scanning Electron Microscope (SEM) experiments have been performed on concrete specimens. The obtained results show that addition of kaolinite powder to concrete will cause a pozzolanic reaction and decrease the permeability of concrete samples comparing to the reference concrete specimen. Further, various machine learning methods have been used to predict ASR-induced expansion per different amounts of kaolinite. In the process of modeling methods, optimal method is considered to have the lowest mean square error (MSE) simultaneous to having the highest correlation coefficient (R). Therefore, to evaluate the efficiency of the proposed model, the results of the support vector machine (SVM) method were compared with the decision tree method, regression analysis and neural network algorithm. The results of comparison of forecasting tools showed that support vector machines have outperformed the results of other methods. Therefore, the support vector machine method can be mentioned as an effective approach to predict ASR-induced expansion.

Buckling analysis of nanocomposite plates coated by magnetostrictive layer

Moein Tabbakh,Mohsen Nasihatgozar 국제구조공학회 2018 Smart Structures and Systems, An International Jou Vol.22 No.6

In this project, buckling response of polymeric plates reinforced with carbon nanotubes (CNTs) and coated by magnetostrictive layer was studied. The equivalent nanocomposite properties are determined using Mori-Tanak model considering agglomeration effects. The structure is simulated with first order shear deformation theory (FSDT). Employing strains-displacements, stress-strain, the energy equations of the structure are obtained. Using Hamilton's principal, the governing equations are derived considering the coupling of mechanical displacements and magnetic field. Using Navier method, the buckling load of the sandwich structure is obtained. The influences of volume percent and agglomeration of CNTs, geometrical parameters and magnetic field on the buckling load are investigated. Results show that with increasing volume percent of CNTs, the buckling load increases. In addition, applying magnetic field, increases the frequency of the sandwich structure.

An Analytical Model for FRP Debonding in Strengthened RC Beams under Monotonic and Cyclic Loads

Moein, Reza Saeidi,Tasnimi, Abbas Ali Korea Concrete Institute 2016 International Journal of Concrete Structures and M Vol.10 No.4

Reinforced concrete (RC) beams strengthened by externally bonded reinforcement often fail by debonding. This paper presents an experimental and analytical study aimed at better understanding and modeling the fiber reinforced polymer (FRP) debonding failures in strengthened RC beams under monotonic and cyclic loads. In order to investigate the flexural behavior and failure modes of FRP-strengthened beams under monotonic and cyclic loadings, an experimental program was carried out. An analytical study based on the energy balance of the system was also performed. It considers the dominant mechanisms of energy dissipation during debonding and predicts the failure load of the strengthened beams. Validation of the model was carried out using test data obtained from the own experimental investigation.

Different finite element techniques to predict welding residual stresses in aluminum alloy plates

Hadi Moein,Iradj Sattari-Far 대한기계학회 2014 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.28 No.2

This study is a 3D thermomechanical finite element (FE) analysis of a single-pass and butt-welded work-hardened aluminum (Al)5456 plates. It aims to validate the use of FE welding simulations to predict residual stress states in assessing the integrity of weldedcomponents. The predicted final residual stresses in the plate from the FE simulations are verified through comparison with experimentalmeasurements. Three techniques are used to simulate the welding process. In the first two approaches, welding deposition is applied byusing element birth and interaction techniques. In the third approach, the entire weld zone is simultaneously deposited. Results show avalue at approximately the yield strength for longitudinal residual stresses of the welded center of the butt-welded Al alloy plates with athickness of 2 mm. Considering the application of a comprehensive heat source, along with heat loss modeling and the temperaturedependentproperties of the material, the approach without deposition predicts a reasonable distribution of residual stresses. However, theelement birth and interaction techniques, compared with the no-deposit technique, provide more accurate results in calculating residualstresses. Furthermore, the element interaction technique, compared with the element birth technique, exhibits higher efficiency and flexibilityin modeling the deposition of welded metals as well as less modeling cost.

Gas sensing behavior of Cu2O and CuO/Cu2O composite nanowires synthesized by template-assisted electrodeposition

Hadiyan Moein,Salehi Alireza,Mirzanejad Hamid 한국세라믹학회 2021 한국세라믹학회지 Vol.58 No.1

Metal oxide-based conductometric gas sensors are one of the promising candidates for highly sensitive, harsh environment resilient, low cost and nontoxic sensors for industrial applications. Here we present conductometric gas sensors based on Cu 2 O and CuO/Cu 2 O composite nanowires investigated towards few VOCs and CO gases. The Cu 2 O nanowires with an average length of 8 μm and diameter of 180 nm were synthesized through template-assisted electrodeposition of Cu 2 O into a polycarbonate membrane pores, from an aqueous solution. The CuO/Cu 2 O composite nanowires were obtained by annealing the synthesized Cu 2 O nanowires in an oxygen environment. The morphology, dimension, and crystallography of the synthesized nanowires are studied using scanning electron microscopy and X-ray diff raction measurements before and after annealing process. Our proposed sensor based on Cu 2 O nanowires showed a fast response in sensing ethanol gas at 250 °C response values of 178 and 15% towards 50 and 1 ppm of ethanol, respectively. CuO/Cu 2 O nanowires behaved selective and sensitive at 150 °C with a response value of 55% towards 500 ppm of CO.

Analysis of Covert Hardware Attacks

Samer Moein,Fayez Gebali,Issa Traore 한국정보기술융합학회 2014 JoC Vol.5 No.3

Current embedded system, such as cell phones and smart-cards, in corporate security devices or cryptographic processor. These cryptographic devices often store private keys or other sensitive data, so compromise of this data or the underlying hardware may lead to loss of privacy, forged access, or monetary theft. Even if the attackers fail to gain the secret information that is stored in a hardware, they may be able to disrupt the hardware or deny service leading to other kinds of security failures in the system. Therefore hardware attacks targets this security devices. Hardware attacks could be covert or overt based on awareness of the targeted system. This paper reviews proposed Accessibility/Resources/Time (ART) schema that quantifies hardware attacks. We focus in this paper on presenting covert attacks and quantify the attack using the ART schema.

Epidemiological Aspects of Cutaneous Leishmaniasis during 2009-2016 in Kashan City, Central Iran

Doroodgar Moein,Doroodgar Masoud,Mahboobi Saeed,Doroodgar Abbas 대한기생충학열대의학회 2018 The Korean Journal of Parasitology Vol.56 No.1

An Analytical Model for FRP Debonding in Strengthened RC Beams under Monotonic and Cyclic Loads

Reza Saeidi Moein,Abbas Ali Tasnimi 한국콘크리트학회 2016 International Journal of Concrete Structures and M Vol.10 No.4

Reinforced concrete (RC) beams strengthened by externally bonded reinforcement often fail by debonding. This paper presents an experimental and analytical study aimed at better understanding and modeling the fiber reinforced polymer (FRP) debonding failures in strengthened RC beams under monotonic and cyclic loads. In order to investigate the flexural behavior and failure modes of FRP-strengthened beams under monotonic and cyclic loadings, an experimental program was carried out. An analytical study based on the energy balance of the system was also performed. It considers the dominant mechanisms of energy dissipation during debonding and predicts the failure load of the strengthened beams. Validation of the model was carried out using test data obtained from the own experimental investigation.