Exteriorists of IRIB in Iran

This paper by introducing a new concept of "exteriorism" in media audience studies, intends to study the "exteriorists" who has been consciously boycott Iranian state TV. According to the authors, the experience of exteriorism is unique and different in any Countries and societies. This qualitative study was conducted by using of In-depth interviews and within the methodological frameworks have studied the grounded theory. Data was collected through 29 semi-structured In-depth interviews. Upon completion of coding and categorizing interviews data in this methodology, presents a theoretical model about exteriorists of Iranian state television. This study aimed to identify perceptions within the meaning of exteriorists as a preface to pull them out, by considering 118 concepts through individual in-depth interviews that formed a theoretical analyzing. Based on results, three main typology of exteriorists experiences as follows; "Resistance and protestation", "Avoid of vulgarity" & "unhappiness of entertainment". Innovation in this paper is achieving recognition of the audience by negation logic & The authors believes that media policy making needed to same deep recognition like this

A review on the statics and dynamics of electrically actuated nano and micro structures

Nano and micro electro-mechanical systems (NEMS and MEMS) have been attracting a large amount of attention recently as they have extensive current/potential applications. However, due to their scale, molecular interaction and size effects are considerably high which needs to be considered in the theoretical modelling of their electro-mechanical behaviour. Both nano- and micro-scale electrically actuated structures are discussed when subjected to constant and time-varying voltages, and different theories and models, introduced in the past few years for modelling such small structures, are discussed. It is highlighted that considering the intermolecular forces and size-dependence effects can change both the static and dynamic behaviours of such systems significantly. This review presents the current stage of the research on electrically actuated NEMS/MEMS by analysing the latest models and studies in this field in the framework of electro-mechanical coupling and small-size effects

Buckling analysis of nonuniform nonlocal strain gradient beams using generalized differential quadrature method

Recently, it was shown that the length scales presented in nonlocal elasticity and strain gradient theory each describe a different physical and material properties of structures at small scales. Accordingly, in this article, by using the new accurate nonlocal strain gradient theory, buckling behavior of nonuniform small-scale beam is investigated. Nanobeam is assumed with variable cross section through the length by exponentially varying the width. According to the size effects, higher order strain deformations and nonlocal effects are modeled on the Euler-Bernoulli beam. Governing equation of motion is presented using Hamilton's principle for nonuniform nonlocal strain gradient beams and solved using generalized differential quadrature method for higher order differential equations. Accuracy of the current methodology is discussed by increasing the number of sampling points and merging to unique solutions. Moreover, in order comprehend the nonuniformity effects on nonlocal strain gradient beams, parametric study is done and presented for different variables. It is shown that nonuniformity could have a significant efficacy on critical buckling loads depending on the ratio between nonlocal and strain gradient parameters. This study is a step forward in better understanding the behavior of nonuniform small scale beams to be used in different nanoscale structures. Keywords: Buckling, Nonlocal strain gradient theory, Nonuniform nanobeam, Variable cross section, GDQ

Effects of geometric nonlinearities on the coupled dynamics of CNT strengthened composite beams with porosity, mass and geometric imperfections

This study investigates the effects of geometric nonlinearities on the dynamical behaviour of carbon nanotube (CNT) strengthened imperfect composite beams by considering both axial and transverse motions. For the given general model of the beam, the system modelling has been adopted from the literature and the nonlinear dynamic response in presence of an external harmonic load is examined for the first time in the case of axially functionally graded (AFG) CNT fibre, which is used for strengthening the structure. Porosity imperfection with the ability to vary though the thickness is modelled using simple, closed and open-cell models; the porosity variation is formulated using uniform, linear, symmetric and un-symmetric models. The geometrical imperfection is considered by allowing the beam to have an initial curved longitudinal axis and the mass imperfection is modelled by introducing a concentrated mass at a certain point of the beam. Using a combination of the Galerkin scheme together with dynamic equilibrium technique, the influence of different imperfections and porosities on the frequency response of the system is examined. It is shown that, for the case of AFG CNT strengthened beam, geometrical imperfection can change the nonlinear response from a hardening to a softening behaviour. Besides, the importance of considering the interaction between axial and transverse motion is examined in detail. The influence of lumped mass imperfection and its position is also studied showing that this type of imperfection can change the nonlinear behaviour of the system significantly. Moreover, the influence of increasing the CNT volume fraction and functionally spreading the CNTs through the length is discussed. The results are useful for analysing the resonance phenomena in strengthened structures facing various imperfections. Graphic abstract: [Figure not available: see fulltext.