h. sarfaraz

"Media Education" in common formal models is a product of the educational system; however, the focus of this paper is on informal models of media education, which implicitly emerge with more complex connotations compared to formal and explicit models. The issue of informal media education has become more significant due to the phenomenon of digitization in education, and the prominence of alternative teaching-learning methods intensifies it. As a result, finding educational implications outside the formal contexts of the classroom, school, faculty, university, and other official educational institutions is of great importance. The path to finding these implications is self-reflective and comes through the context of media culture, which is both constructed by the media and encompasses them. Every medium has a specific function in constructing media culture and assigning meaning to it. From the perspective of this paper, media culture is the result of a media struggle over legitimizing meanings, and media literacy will be the critical dimension embedded in the layers of this media culture—layers marked by the integration of two theoretical models of cultural analysis. In other words, educational culture in the space of the digitization of education is inherently a media culture. On one hand, a model of media literacy is presented within media culture, the most important feature of which is the ability to reflect the dynamics within media culture. One of the key features of this model is its focus on the educational aspects of all elements involved in the media culture circuit as a field of central and peripheral forces. These elements include representation, identity, production, consumption, and regulation. On the other hand, by applying a semiotic reading of the Taqato' (Crossroad) TV documentary, the paper examines the application of the proposed model in exploring the educational implications of intermedia confrontation, specifically between television as a central medium and social media as a peripheral medium in the context of the phenomenon known as the Green Movement and the events following the 2009 presidential election in Iran.

A common instability in the rock slopes is a toppling failure. If this type of slope failure occurs due to another kind of failure, it is considered as the secondary toppling failure. A type of secondary toppling failure is the slide-head-toppling failure. In this instability, the upper portion of the slope is toppled, and the pressure caused by the overturning of rock blocks leads to a semi-circular sliding in the soil mass at the slope toe. This instability is examined through the theoretical analysis and physical modelling. Firstly, the failure mechanism mentioned above is described. Next, the slide-head-toppling failure is studied through seven numerical simulations. The Phase2 and UDEC softwares, as the finite element and distinct element methods, respectively, are used in this work. Different kinds of slide-head-toppling failure are modelled such as the blocky, block-flexural, and flexural toppling failures. The numerical modelling results are compared with the existing physical tests and theoretical approaches. This comparison illustrates that the safety factor is underestimated due to the plane strain supposition in numerical modelling. However, the side-friction in the physical models has violated this assumption. The results obtained demonstrate that the distinct element method has an acceptable accuracy compared to the finite element method. Thus this numerical code can be used in order to examine the mentioned failure.

One of the most important tasks in designing the undercut slopes is to determine the maximum stable undercut span to which various parameters such as the shear strength of the soil and the geometrical properties of the slope are related. Based on the arching phenomenon, by undercutting a slope, the weight load of the slope is transferred to the adjacent parts, leading to an increase in the stability of the slope. However, it may also lead to a ploughing failure on the adjacent parts. The application of counterweight on the adjacent parts of an undercut slope is a useful technique to prevent the ploughing failure. In other words, the slopes become stronger as an additional weight is put to the legs; hence, the excavated area can be increased to a wider span before the failure of the slope. This technique could be applied in order to stabilize the temporary slopes. In this work, determination of the maximum width of an undercut span is evaluated under both the static and pseudo-static conditions using numerical analyses. A series of tests are conducted with 120 numerical models using various values for the slope angles, the pseudo-static seismic loads, and the counterweight widths. The numerical results obtained are examined with a statistical method using the response surface methodology. An analysis of variance is carried out in order to investigate the influence of each input variable on the response parameter, and a new equation is derived for computation of the maximum stable undercut span in terms of the input parameters.

One of the most conventional toppling instabilities is the block-flexural toppling failure that occurs in civil and mining engineering projects. In this kind of failure, some rock columns are broken due to tensile bending stresses, and the others are overturned due to their weights, and finally, all of the blocks topple together. A specific feature of spheroidal weathering is the rounding of the rock column edges. In the mode of flexural toppling failure, rounding of edges happens only at the upper corners of the block but in the block toppling failure mode, due to the presence of cross-joints at the base of the block, rounding of edges also occurs at the base of the block. In this work, a theoretical model is offered to block-flexural toppling failure regarding the erosion phenomenon. The suggested methodology is evaluated through a typical example and a case study. The results of this research work illustrate that in the stable slopes with rectangular prismatic blocks, where the safety factor value is close to one, the slope is subjected to failure due to erosion. Also the results obtained show that the recommended approach is conservative in analyzing the block-flexural toppling failure, and this approach can be applied to evaluate this failure.