Evaluation of 2D Seismic Site Response due to Hill-Cavity Interaction Using Boundary Element Technique

This paper deals with the evaluation of two-dimensional site-effects due to the seismic interaction between hills with various configurations and underground cavities. The time-domain boundary element method is used to evaluate the site-effects of hill-cavity interaction subjected to vertically propagating in-plane SV and P waves. The presence of an underground cavity and the hill topography are expected to induce significant effects on the surface ground motion. To further examine the contribution of the amplification ratio of the hill-cavity system, a fairly simple approach, which can compute the response spectra of the hill’s surface motion above a cavity based on the real input motions, is also used to input motions.     

REGIONAL VARIATIONS IN TECHNOLOGICAL CHANGE AND IN POTENTIAL GAINS FROM CONSOLIDATION AMONG U.S. COMMERCIAL BANKS

ABSTRACT. This paper investigates the regional variations in the impact of technological change and in gains from consolidation among U.S. commercial banks. We estimate a multiproduct translog cost function with the appropriate regional dummy variables. Technological change, ray scale economies and scale biases in technological change are estimated for each region. Furthermore, pairwise expansion path economies between all the regions are calculated to evaluate the potential gains from interregional consolidation. In general Southwest banks had the worst and Southeast the best technological change. There is substantial disparity across regions. It also appears that technological change increased the efficient size in the Midwest and Southwest regions and reduced it in the West, Northeast and Southeast. Banks in all regions show ray economies of scale, affirming the need for larger banks if output mix remains constant. Finally, the results support takeover of regional banks by the Money Center banks but not vice-versa, and favor consolidation among regional banks. The biggest potential gains accrue from mergers of Southeast banks with either Midwest or Southwest banks and the least gains are derived from mergers between Midwest and Southwest banks.     

A late Holocene pollen record from Lake Almalou in NW Iran: evidence for changing land-use in relation to some historical events during the last 3700 years

A pollen diagram was prepared from Lake Almalou, a volcanic crater wetland located on the eastern flanks of the Sahand Volcanic Complex in NW Iran. The core provides a 3700-year record of human activity and environmental change in an upland region. We attempt to relate vegetation changes to both climatic change and historical events. Variations of anthropogenic pollen indicators suggest several phases of intensified human activities. Two strongly expressed agricultural phases are dated at about 2450–2220 cal BP (Achaemenid Empire) and 230–30 cal BP (collapse of Safavid Dynasty to the modern period). Historical rather than climatic events appear to be the main controlling factors for upland land-use dynamics. Fruticulture has been practiced in the region at least since the Iron Age, reaching its maximum importance 1500–1250 cal BP during the reign of Sassanid Empire; it declined by the time of Islamic conquest of Iran (651 AD). The Little Ice Age is tangibly recorded by higher lake water levels most probably due to both lower summer temperatures and higher annual precipitations. Low values of cereal-type and cultivated tree pollen during this period may indicate a change in the lifestyle from the cultivation of fields and orchards to a more nomadic life dominated by summer pasture. The modern period (1850 AD onwards) is characterized by expansion of agricultural activities to upland areas and intensified pastoralism.     

The Question of Identity vis-à-vis Exoticism in Contemporary Iranian Art

This essay explores two primary concerns in the art and artistic practice of contemporary Iran, namely “identity” (i.e. local, historical, imagined and collective identity and also self-identity) and “exoticism” (which appears inevitably related to the first), both of which (identity and exoticism) involve challenges relating to the “self” and “other” and the issue of “expectation”. It suggests that these issues see broader contextual socio-political parallels. The first apprehension relates to the concept of identity which addresses how artists have interpreted contemporary aesthetics in the light of national and indigenous ideology. The second refers to the ever-present obsession with cultural and frequently social concern with which Iranian artists are engaged within the country. The two concerns are integrated, in the way that the second is seen to be the outcome of the first. Some critiques are based on the issues of cultural commodification, anti-canonical West, cultural formulation, and also the stereotypes rooted in the preference and interest of the market.     

From the Land of the Pure,in Search of the Lost Origin: An Interview with Bahram Beyzaie on Siyavush-Khani (Siyavush Recitation) and its Mythological and Literary Roots

The interview was conducted in 1997 after the publication of Beyzaie's extraordinary engagement with the legend of Siyavush in Siyavush-Khani (Siyavush Recitation). Beyzaie's experiments with Shahnameh legends are not adaptations in the strict sense of the term. This is primarily because their stories are often different from what appears in the Shahnameh, mix the narratives with other mythical sources and place them in contemporary templates with an inter-paradigmatic gaze that reflects on the meaning and the history of the present. The interview is significant in that, as it has been conducted by a leading playwright and scholar of Iranian performing arts, it enables the reader to have firsthand experience of working in Iran as a playwright and reveals some of the methods Beyzaie uses to handle his subjects.     

Experimental Evaluation of Seismically and Non-Seismically Detailed External RC Beam-Column Joints

An experimental investigation was undertaken to study the seismic performance of external reinforced concrete (RC) beam-column joints having representative details for mid-rise RC frame buildings in developing countries such as Iran that were designed and constructed prior to the 1970s. Three half-scale external RC beam-column joints were tested by applying lateral cyclic loading of increasing amplitudes. Tested specimens were comprised of one unit having seismic reinforcement detailing in accordance with the seismic requirements of ACI 318-11, and two units having non-seismic reinforcement detailing in accordance with the 1970s construction practice in many developing countries, such as Iran. Two typical defects were considered for the non-seismic units, being the absence of transverse steel hoops and insufficient bond capacity of beam bottom reinforcing bars in the joint region. Test results indicated that the non-seismically detailed specimens had a high rate of strength and stiffness degradation when compared to the seismically detailed specimen, which was attributed primarily to the joint shear failure or bond failure of the beam bottom bars. The non-seismically detailed specimens also showed a 30% reduction in both average strength and ductility and a 60% loss of energy dissipation capacity in comparison to the seismically detailed specimen.