Analysis of stability in arch structures is a well-known fact in the conservation of historical monuments, stabilizing efforts, and the design of vernacular and rural structures. Therefore, the authors of this paper are set to explore and compare the threshold values of the seismic stability of three Persian arches, i. e., tokhm-e morqi, morabbaʿ , and panj-o-haft-e-tond. This experimental research uses geometrical analysis and physical models to find the threshold values for the seismic stability of these arches. Analysis of the arches is performed for different thickness-to-span ratios within the “ limit state analysis” framework, using “ thrust line analysis” with parametric modeling which offers a rigorous and rapid investigation. The results are then compared with the behavior of physical models. The thrust line analysis results show that the seismic stability of these arches, compared to one another, increases by increasing the thickness-to-span ratio and decreasing their rises. The physical models verify these results but show lower threshold values for seismic stability of the arches. So, the effective thickness of the arches must be considered in the analysis. Besides answering a practical problem, this paper gives an insight into the structural behavior of arches.

The application of structural arch form in Iran goes back to as far as thousands of years ago. Arch is a fundamental component of Iranian architecture. Other structural systems such as vaults and domes which are used widely in variety of structures are indeed derived from arches. In the present study, the stability of various Iranian arches versus their weight, surcharge and earthquake action is investigated. The selected arches are some of the most applied Iranian arches like: parabolic-shaped arches, onion-shaped arches, four-centered pointed arches, obtuse angel arches and basket-handle arches. The selected arches are modeled in AutoCAD software and then are exported into the ANSYS software for necessary analyses. The static analysis, modal analysis and linear and non-linear dynamic analysis have been carried out on the finite element models of the arches. Comparison of the results of the analyses showed that for the same span and thickness in various Iranian arches analyzed in the present study, the parabolic-shaped arch has a better bearing with respect to gravity and lateral loads. The static stability of the arches under the gravity load increases with rise to span ratio of the arch. The other factor that affects the arch stability is its angle of contact to the baseline. According to the two above mentioned factors the stability of the selected arches increases in the following order: the semi-elliptical arch, the parabolic-shaped arch, basket-handle arch, circular arch and four-centered pointed arch. The eigne-value analyses have shown that the natural period of the arch in sensitive to the form of the crown. For the same span, the arches with tipped crown possess larger periods. In this regard, the fundamental period for parabolic arch is the least. This shows that this type of arch is stiffer that the other ones. For dynamic analysis of the selected arches, three strong ground motions of Kobe of Japan in 1995 (ML=7.2), Tabas of Iran in 1978 (ML=7.8) and Manjil of Iran in 1990 (Mw=7.4) were selected. Again, the time history analysis of the arches shows that the strongest arch against the selected accelerograms is parabolic arch; and the order of relative seismic stability of the arches descending from high to low is as following: the parabolic-shaped arch, the basket handle arch, the four-centered pointed arch, the Semi-elliptical arch and the circular arch. Also, under the Kobe earthquake accelerogram, the parabolic arch showed no collapse. However, the other arches encountered collapse and among the circular arch collapsed at 5.8 seconds as the first arch and the basket handle arch collapsed at 8.5 as the last one. As another result, the location of cracks in the arches damaged by seismic loading was in the internal face of the arch.

Shortly after gulf war (G.W) thousands of war veterans referred with sign and symptoms of an unknown disease called G.W illness. Despite multiple studies undertaken by several non-governmental and governmental centers this illness remains unclassified and can not be coded by international classification of disease (I.C.D). The etiology has not been found and the illness appears to be multifactorial and basically related to use of depleted uranium (D.U) weapons, chemical warfare (C.W) and biological agents. This article reviews this illness and the adverse effects of D.U and B.c.W agents in the G.W battlefields.

Easy access to social media enables users to express their opinions and ideology about various topics like news, videos, and personalities freely, without any fear, and often in an offensive manner. It is a vital task to detect comments with offensive language on social media platforms and relies on a complete and comprehensive tagged dataset. Therefore, in this paper, we introduce and make publicly available PerBOLD, a new Persian comment dataset collected from Instagram as a popular platform among Iranian. We follow a two-level manual annotation process in order to determine whether a comment has offensive language or not and fine-grained tags of different types of offensive language. Furthermore, we present some interesting aspects of data and analysis them.

arches, vaults and domes are common features in the cultures of old civilizations. They were usually made of sun-dried bricks, fired bricks or stones with different types of mortar. The majority of these components are vulnerable to seismic effects. To present a viable study on their seismic vulnerability, all the factors influencing their behavior need to be investigated. In this paper, the construction materials used and the structural features of these elements are briefly described. Furthermore, the different aspects of using numerical methods for analyzing these elements are discussed. Finally, measures needed to improve their resistance are suggested.