Sedimentation rates in the Lake Qattinah using 210Pb and 137Cs as geochronometer

The constant rate of supply (CRS) of excess ²¹⁰Pb model was successfully applied to assess ²¹⁰Pb data of two sediment cores from the lake Qattinah, Syria. Gamma spectrometry was used to determine ¹³⁷Cs and ²¹⁰Pb activity concentrations. The bottom of the cores was ²¹⁰Pb-dated to years 1907 and 1893. The accumulation rates were determined using ²¹⁰Pb method and found to vary similarly in both cores from 0.10 ± 0.01 to 3.78 ± 0.57 kg m^?2 y^?1 during the past century. ¹³⁷Cs was used as an in-dependent chronometer. The two distinct peaks observed on the ¹³⁷Cs record of both cores, corresponding to 1965 and 1986, have allowed a successful validation of the CRS model.     

Experimental Study on Postponing the Deboning of FRP Sheets in Masonry Walls

ABSTRACT

A large number of buildings all around the world are constructed of unreinforced masonry. These structures do not act well during earthquakes because of their vulnerable behavior. In last two decades, fiber-reinforced polymers (FRPs) has been used widely in seismic rehabilitation and strengthening unreinforced concrete and masonry structures. One important issue in using FRP composites for strengthening masonry walls is the inopportune debonding of composites from the wall surface; thus, in this article new methods are proposed to further delay the mentioned debonding issue. For this purpose, 13 masonry panels with 100x870x870 mm dimension are strengthened by using carbon and glass FRPs (CFRPs and GFRPs). A variety of strengthening methods such as surface preparation, boring, grooving, nailing, and plaster are used to mount FRP composites to the walls. For each specimen subjected to diagonal compression test, the loading level along with tensile and compressive diagonal displacements are evaluated. In order to assess the effect of FRP composites, four unreinforced masonry walls are tested as well. The results show 110% increase in ductility index of reinforced specimens compared to the unreinforced ones.     

Habermas and Iranian Intellectuals

In this paper, we discuss the impact of Jürgen Habermas' ideas on Iranian intellectuals who live in Iran. The upshot of the paper is that in present day Iran, where the society is going through a significant transitional period, various intellectual groups have reacted differently towards the ideas of the German philosopher-sociologist. While the orthodox left-wing (ex-Marxist) intellectuals and the conservative right-wing writers have, by and large, tended to ignore his views, a younger generation of the left-wing intellectuals and a number of the Muslim intellectuals with left-wing/socialist tendencies, have tried, each in their own ways, to ‘adopt’ Habermas' ideas in pursuit of their own projects/research programs.     

FARMERS,HERDERS OR TRADESMEN? ANALYSING SETTLEMENT PATTERNS OF THE MIDDLE AND LATE BRONZE AGE ON THE SARFIROUZABAD PLAIN,KERMANSHAH, WESTERN IRAN

The highland plains of western Iran have been investigated with varying intensity. The Sarfirouzabad Plain located in the south of Kermanshah province, although visited perfunctorily, has not previously been studied systematically, despite attractive ecological and environmental conditions. In 2009, a team from Tehran University conducted a systematic and intensive field survey in the region to identify Bronze Age settlements and to assess their location in relation to ecological, environmental and cultural factors that may have impacted their distribution on the plain. The surveyed area was walked in transects at 20‐metre intervals and resulted in the identification of 332 archaeological sites from different cultural periods, which added much to the limited knowledge about the history of this region. Twenty‐four of these settlement sites belong to the Middle and Late Bronze Age horizons. This study uses GIS to map the distribution of archaeological materials and construct spatial models to determine the significance of the distribution patterns of the Bronze Age sites.     

A Bayesian Updating Applied to Earthquake Ground-Motion Prediction Equations for Iran

This article presents new ground-motion prediction equations for three distinct seismic regions of Iran via updating the previous global model using observed data for each region by means of Bayesian updating. The Bayesian theory has the advantage that it results in more accurate results even in situations when little data is available. This leads the way for updating global models to obtain new local models for seismotectonic regions with little available data like Iran. The proposed updated model was compared against currently available models for Iran and the results reveal the overall stability and quality performance of the proposed model.     

An Improved Displacement-Based Adaptive Pushover Procedure for the Analysis of Frame Buildings

The main purpose of this article is to develop an alternative adaptive pushover method in which multiple inelastic response spectra proportional to the instantaneous ductility ratio of the structure are employed to reflect the actual energy dissipation characteristic of the structure at a given deformation level. Based on the proposed methodology, two load patterns are independently applied to the structure and the envelope of the demand values is computed. The obtained results demonstrate that the proposed method provides improved predictions of the peak interstory and total drift profiles of the structure.     

Predictive Tri-Linear Benchmark Curve for In-Plane Behavior of Adobe Walls

In the present study, numerical simulations are conducted to estimate the in-plane response of adobe walls subjected to pseudo-static cyclic loading based on the finite element code ABAQUS. The simplified micro-modeling approach is adopted and an interface model reported in ABAQUS material library is applied as material model for zero-thickness interface elements. The comparison between obtained results and field test data results in good agreement. Parametric studies are carried out to evaluate the effectiveness of independent parameters changes on response of adobe walls. It is noted that mechanical properties of joints and adobe units play an active role on in-plane behavior of walls. A tri-linear benchmark curve is proposed to predict the response of aforementioned walls. In this regard, a statistical study is performed to derive the predictive tri-linear benchmark curve. The regressive analysis on 59 numerical models resulted in proposing predictive models. Finally, by comparing tri-linear curves obtained from the regressive analysis, numerical analysis, and experimental study, appropriate accuracy of theoretical model can be found.