Despite the unique occurrences of structural defects in graphene synthesis, the fracture mechanism of a defective graphene sheet has not been fully understood due to the complexities of the defects. In this study, the fracture mechanism of the monolayer graphene with four common types of defects (single vacancy defect, divacancy defect, Stone-Wales defect and line vacancy defect) were investiga...

A molecular dynamics simulation study on the interfacial strengthening between defected graphene and polypropylene matrix is implemented. As intrinsic defects in single layer graphene, oxidation, Thrower-Stone-Wales(TSW) defect, and Adatom defect are considered. On the transversely isotropic nanocomposites unit cell embedding different defected graphene, transversely isotropic stress-strain rel...

In this work, we report for the first time crucial role of topological anomalies like Stone-Wales (SW) type bond rotations in tuning optical properties graphene quantum dots (GQDs). By means first-principles calculations, show that structural stability GQDs strongly depends on position SW defects. Optical absorption spectra is then computed using electron-correlated methodology to demonstrate r...

background: congenital heart disease (chd) is the most common congenital anomaly in newborns. this study was performed to determine the live birth incidence of chd by ethnicity and sex in gorgan, northern iran. methods: in this longitudinal, hospital-based study, 18162 live births in dezyani hospital in gorgan, north of iran, were screened for chd, from 2007 through 2009. clinical examination, ...

The graphene microchannel heat sinks have attracted extensive attention due to its high cooling efficiency in microelectric devices. interfacial thermal resistance (ITR) between as the bottom layer of and water is one key factors good working performance. In this paper, impacts structure defects surfaces on ITR graphene–water interface are investigated using molecular dynamic simulations. resul...

background: closure of patent ductus arteriosus (pda), ventricular septal defect (vsd) and atrial septal defect (asd) can be done surgically or by device. this study was designed to compare the total cost of surgical or device closures of pda, asd or vsd for iranian patients. methods: this is a cross-sectional study, conducted from january 1, 2005 until january 1, 2006 in two large heart center...

this is a case presentation of a 26-year-old woman with a moderate-sized atrial septal secundum defect (17mm) who underwent catheterism, during which an amplatzer septal occluder number 26 was inserted successfully. on the second postoperative day, she deteriorated and a clinical examination showed a typical tamponade. after a percutaneous aspiration of the pericardial cavity and transient impr...

It has been shown that the two different orientations of Stone-Wales (SW) defects, i.e. longitudinal and circumferential SW defects, on carbon nanotubes (CNTs) result in two different electronic structures. Based on density functional theory we have shown that the longitudinal SW defects do not open a bandgap near the Fermi energy, while a relatively small bandgap emerges in tubes with circumfe...

Two-dimensional covalent organic frameworks (2D COFs) are an interesting class of 2D materials since their reticular synthesis allows the tailored design structures and functionalities. For many applications mechanical stability performance is important aspect. Here, we use a computational approach involving density-functional based tight-binding method to calculate in-plane elastic properties ...

Extended line defects in two-dimensional (2D) materials can play an important role in modulating their electronic properties. During the experimental synthesis of 2D materials, line defects are commonly generated at grain boundaries between domains of different orientations. In this work, twelve types of line-defect structures in single crystalline phosphorene are examined by using first-princi...