A Review on Modeling, Synthesis, and Properties of Graphene

Every few years, a new material with unique properties emerges and fascinates the scientific community, typical recent examples being high-temperature superconductors and carbon nanotubes. Graphene is the latest sensation with unusual properties, such as half-integer quantum Hall effect and ballistic electron transport. In this work, we introduce graphene and its property such as mechanical, thermal, and electrical properties. Furthermore, we briefly mention some of processes that are used for production of graphene. We will continue our discussion to review the approaches that have arose to analyze graphene and other nanoplates

A nonlocal timoshenko beam theory for vibration analysis of thick nanobeams using differential transform method

This article presents the solution for free vibration of nanobeams based on Eringen nonlocal elasticity theory and Timoshenko beam theory. The small scale effect is considered in the first theory, and the transverse shear deformation effects as well as rotary inertia are taken into account in the latter one. Through variational formulation and the Hamilton principle, the governing differential equations of free vibration of the nonlocal Timoshenko beam and the boundary conditions are derived. The obtained equations are solved by the differential transformation method (DTM) for various frequency modes of the beams with different end conditions. In addition, the effects of slenderness and on vibration behavior are presented. It is revealed that the slenderness affects the vibration characteristics slightly whilst the small scale plays a significant role in the vibration behavior of the nanobeam

Stochastic Approximation for Estimating the Price of Stability in Stochastic Nash Games

The goal in this paper is to approximate the Price of Stability (PoS) in stochastic Nash games using stochastic approximation (SA) schemes. PoS is amongst the most popular metrics in game theory and provides an avenue for estimating the efficiency of Nash games. In particular, knowing the value of PoS can help with designing efficient networked systems, including transportation networks and power market mechanisms. Motivated by the lack of efficient methods for computing the PoS, first we consider stochastic optimization problems with a nonsmooth and merely convex objective function and a merely monotone stochastic variational inequality (SVI) constraint. This problem appears in the numerator of the PoS ratio. We develop a randomized block-coordinate stochastic extra-(sub)gradient method where we employ a novel iterative penalization scheme to account for the mapping of the SVI in each of the two gradient updates of the algorithm. We obtain an iteration complexity of the order $\epsilon^{-4}$ that appears to be best known result for this class of constrained stochastic optimization problems, where $\epsilon$ denotes an arbitrary bound on suitably defined infeasibility and suboptimality metrics. Second, we develop an SA-based scheme for approximating the PoS and derive lower and upper bounds on the approximation error. To validate the theoretical findings, we provide preliminary simulation results on a networked stochastic Nash Cournot competition

Hepatoprotective and Anti-oxidant effects of Nepeta Ispahanica Boiss extract on CCL4 induced liver Injury

Background: Natural products might be applicable as remedial agents with their roles in oxidative stress regulation and as natural antioxidants.  In this regard, Nepeta ispahanica bioss has been utilized in traditional medicine for several functions. Despite numerous properties of the Nepeta species including their antioxidant properties, Nepeta ispahanica boiss effects against hepatic injury induced by carbon tetrachloride (CCl4) have not been studied. This study aimed to investigate the hepatoprotective effects of Nepeta ispahanica boiss on CCL4 induced acute hepatic injury in an animal model.  Materials and Methods: The experiment used a total of 36 male Wistar rats, that were divided into six groups. Except for the intact control groups, all groups received a single intraperitoneal injection of CCl4 after pre‐treatment period with distilled water, Nepeta ispahanica boiss extracts, or legalon. After 24 hours, rats were anesthetized, sacrificed and blood samples were obtained. Serum level of alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), total bilirubin (TB), urea and plasma levels of total protein and malondialdehyde (MDA) were evaluated. Besides, SOD and CAT enzyme activities and GSH levels were determined.  Histopathological studies also were done in liver tissue samples. Results: After the CCl4 injection, oxidative stress‐mediated necrotic acute liver injuries were observed. Also, serum ALP, AST, and ALT elevated. Hepatic lipid peroxidation and related decrease of endogenous antioxidants and antioxidative enzymes; lipid peroxidation markers, and oxidative stress markers were presented. Nevertheless, histological and biochemical markers of liver injury were reserved by the pre‐treatment with Nepeta ispahanica boiss extracts. Conclusion: The present study confirmed that the administration of Nepeta ispahanica boiss extracts before exposure to CCl4, induced significant hepatoprotective effects. These findings verified that Nepeta ispahanica boiss has favorable properties as an antioxidant and hepatoprotective agent

Optimization Process for Bending a Periodic Structure: Start Ahead with Neural Networks

Optimizing high-dimensional designs requires essential efforts; bending of a radiating device is one of such examples. Such appearance appears in various applications like medical, space, radar, etc. Consequently, strong numerical methods are becoming necessary. In the present work, an optimized bent periodic structure, multiple-input and multiple-output (MIMO) antenna designed through a neural network (NN) is presented. The main goal of this optimization is to focus on the curvature of the antenna to find the suitable results for S-parameters both in terms of reflection S 11 , and transmission S 21 coefficients, and also total active reflection coefficient (TARC). Through the proposed method, the antenna configuration loaded by meandered slot and surrounded by printed meander line of different periodicities is designed and optimized in three frequency bands within the 12.94 GHz to 25 GHz range, namely, 12.94 - 14.79 GHz, 16.09 - 17.25 GHz, and 19.17 - 25 GHz

Impacts of urban passages on formation of Iranian bazaars : case study of the historic bazaar of Tabriz

Bazaars have long since been of the most influential components of the traditional Iranian cities, having significant impacts on the formation and development of many Iranian cities. This study was motivated by the fact that the subject of bazaar and its mutual relationship with the formation of Iranian civilization has not yet been taken into account well. The study adapted an interpretive-historical research approach that utilized archival research as well as field studies and validated the findings through triangulation of findings with the seminal literature. It chose the historical bazaar of Tabriz as the case of study. Findings proposed that among the important components of the traditional Iranian cities, urban passages and organs have had the highest impacts on the formation and development of bazaars. The study concluded that in the context of Tabriz, traditional urban passages and the bazaar have had significant impacts on the formation of each other. This was a unique and significant study, which discovered new aspects of the important roles of bazaars in formation of Islamic cities and cultures