FRICTION DAMPED STEEL MOMENT-RESISTING FRAMES SUBJECTED TO LONG-DISTANCE EARTHQUAKES: INFLUENCE OF WELD FRACTURES

It has been generally accepted that steel moment-resisting frames behave in a ductile manner under seismic excitations. However, during the 1994 Northridge earthquake in California, weld fractures at the beam-to-column connections occurred in many steel buildings. Such brittle failures obviously precluded the traditional ductile-behaviour assumption and had a significant effect on the responses of steel moment-resisting frames. In this paper, the performance of a friction damping system for retrofitting steel moment-resisting frames was investigated under long-distance earthquakes. For this purpose, the 1985 Mexico City (SCT), the 1995 Bangkok, or the 1977 Romania ground motions, all scaled to a peak ground acceleration of 0.17 g, were considered in this study. Responses of the building under the 1940 El Centro N-S component were also included for comparison. The results of the study show that a friction damping system can reduce the seismic responses significantly. The devices can also prevent the total collapse and joint failures of the building equipped with friction dampers, while the one without dampers would collapse, even under a peak ground acceleration of only 0.17 g.     

Searching for the perfect nation: the itinerary of Hans Kohn (1891–1971)

ABSTRACT. The ‘Hans Kohn Dichotomy’, i.e. the distinction between ‘Western’ and ‘Non‐Western’ nationalism, remains one of the most persistent paradigms in the study of nationalism. This article deals briefly with the terms of Kohn's Dichotomy and with the discussion about it. The main purpose of the article, however, is to problematise the dichotomy in terms of Kohn's personal itinerary which took him from Prague to Russia, and from Britain and Palestine to the United States. Kohn came late to the view that there were two types of nationalism. He adopted this position in the wake of a series of political and personal disappointments, and in response to dramatic historical challenges. In the final analysis, Kohn's Dichotomy was a rhetorical construct, designed to make sense of a world in conflict and to allow Kohn and others, then and later, to come to terms with the hopes and fears raised by nationalism.     

Comparing Regional Biodiversity Benefits of Investment Strategies for Land‐Use Change

The need for public investment to address loss of biodiversity in agricultural landscapes is well recognised, yet there is little analysis of the likely benefits of land‐use change for regional biodiversity or the cost effectiveness of different investment options. We estimated benefits for biodiversity and cost effectiveness of different investment scenarios over 50 years for a farming area in south‐eastern Australia. Declines in biodiversity were predicted under status quo land use. Implementing actions in the investment scenarios improved biodiversity status only slightly, compared with status quo land use. Future biodiversity status differed little between biodiversity‐focused investment and salinity‐focused investment. Biodiversity status equalled or exceeded current status only for investment scenarios with much more extensive revegetation than in catchment targets. Cost effectiveness of biodiversity improvement varied greatly between investment strategies. Biodiversity improvement was more cost effective when investment to meet catchment targets was focused on revegetation for salinity management rather than on high conservation value areas, because of lower opportunity costs for salinity management. With enhanced investment, the cost effectiveness of biodiversity improvement was greater when actions were in high conservation areas. Although improvements in biodiversity were small under the changed farming system scenarios, their cost effectiveness was higher than the other investment scenarios. Regional scale improvements in biodiversity in farming areas will require increased stewardship payments or other economic incentives for landholders.     

Apologia of Classical Evolutionism

Hans C. Buechler and Judith‐Maria Buechler. Carmen: The Autobiography of a Spanish Galician Woman. Cambridge, Massachusetts: Schenkman Publishing Company, 1981. xxxi + 242 pp. Index, illustrations. $16.95 cloth, $7.95 paper.