Assessment of Effects of Reductions of Lateral Stiffness along Height on Buildings Modeled as Elastic Cantilever Shear Beams

A simplified model useful for assessing economic losses due to moderate seismicity events in urban areas has been developed by studying the behavior of buildings before yielding their structural system, allowing for nonuniform stiffness along their height. In particular, buildings are modeled as cantilever shear beams with uniform mass and parabolic reduction of lateral stiffness. This particular stiffness distribution is relevant, as it could be expected to occur in buildings where earthquake action is a critical structural design criterion. The equation of motion governing the dynamic behavior of the proposed model is solved analytically, finding mode shapes in terms of first and second zero-order Legendre functions. The solution is verified by comparing it with results obtained from fine mesh finite element models. The effect of reducing the lateral stiffness is then studied in the first five modes of vibration. Results include modal periods, mode shapes, modal participation factors, and derivatives of mode shapes. In general, it is found that effects of reduction of lateral stiffness in mode shapes are moderate when the lateral stiffness in the free end is smaller than about seventy percent of the lateral stiffness at the fixed end, but become significant for larger reductions. Effects are particularly important for the derivative of the mode shapes, which could play a significant role in estimating interstory drift demands in buildings. Model usefulness is showcased by analyzing a test case where both acceleration and drift demands are assessed by considering uniform beams and beams with parabolic stiffness variation, finding notable improvements by considering the latter.     

The colors of the Fontana di Trevi: an analytical approach

During the last restoration of the Fontana di Trevi -Rome (2014–2015), it has been performed a diagnostic investigation to characterize the materials used to build and obtain the colors of the surfaces of some architectural elements of this fountain. According to the restoration teamwork needs, we focussed our efforts on the dome over the central statue of Oceanus, on the bas-relieves on the sides of the dome, and on the cliff where the water flows. Several samples were collected from these elements and therefore, they were subjected to an analytical approach including infrared spectroscopy, optical and scanning electron microscopy. The achieved results indicated the use of red earth pigments on the dome. The same pigment has been revealed on the bas-relieves, although their colors have an additional contribution due to degraded layers. Samples taken from the cliff showed a complex stratigraphy, although a white scialbo has been identified as original layer, testifying the intentions of the authors in term of color rendering. This information was essential for the restores in order to choose the proper intervention procedure for each investigated surface. The research testified the importance of an integrated diagnostic analysis to preserve the original colours of monuments and building.     

San Juan,the Fragile City: Finance Capital,Class, and the Making of Puerto Rico's Economic Crisis

This paper narrates Puerto Rico's fiscal and financial crisis through a reading of San Juan's urban landscape. We underscore the role of capital in the city, primarily embodied by the local capitalist class (the Criollo bloc) and foreign capitalists. Historically excluded from the manufacturing sector (dominated by US capitalists), the Criollo bloc accumulates its wealth by concentrating financial assets in the city. In times of crisis, the Criollo bloc resorts to the acquisition of new assets and asset exchange with foreign capitalists to remain solvent and provide short‐term solutions to the state's fiscal and financial limits. The survival of the local capitalist class, we demonstrate, is dependent on asset stripping. Drawing on Clyde Woods, we document how asset stripping unevenly redistributes wealth and risks along class and racial lines within a colonial economy. The finance capital/asset stripping basis of San Juan's economy renders it an extremely fragile city, we contend.     

Comercio y comerciantes en América Latina colonial: Reflexión historiográfíca

Tráfico de Indias y política oceánica. By Fernando Bordejé Y Morencos. Madrid: MAPFRE, 1992. Pp. 341.

Relaciones económicas entre España y América hasta la independencia. By John R. Fisher. Madrid: MAPFRE, 1992. Pp. 280.

Las comunicaciones en América. By Secundino‐José Gutiérrez Alvarez. Madrid: MAPFRE, 1993. Pp. 424.

Piratas, bucaneros, filibusteros y corsarios en América. Perros, mendigos y otros malditos del mar. By Manuel Lucena Salmoral. Madrid: MAPFRE, 1992. Pp. 306.

El dinero americano y la política del imperio. By María Emelina Martín Acosta. Madrid: MAPFRE, 1992. Pp. 333.

Cargadores a Indias. By Julian B. Ruiz Rivera and Manuela Cristina García Bernal. Madrid: Mapfre, 1992. Pp. 395.     

Urban Planning System in Contemporary Spain

This work analyses the main Spanish legislative and urban planning instruments, highlighting some of the most important structural problems of the current Spanish urban realities. The survey on legislation runs from the first Land Use Act of 1956 to the decentralization of the administration and the culmination of the transfer processes to the respective Spanish regions. Later, we study the complete well-structured hierarchy of urban planning instruments in use at present. Finally, we analyse how these and other factors have an influence on the capacity to control housing prices and on a lack of sustainability characterized by the excessive urbanizing use of the land.     

Taxonomic characterisation of fresh Dipterocarpaceae resins by gas chromatography–mass spectrometry (GC–MS): providing clues for identification of unknown archaeological resins

Plant and particularly non-wood forest products have played an important role in the evolution of human cultures all over the world, as source of food but also of raw substances fulfilling material, spiritual, and medicinal requirements. Plant exudates and particularly dammar resins (Dipterocarpaceae family) were widely used in the past in Asia notably as waterproofing and caulking materials. This study focuses on the GC–MS chemical characterisation of freshly collected dammars and establishes new molecular parameters enabling discrimination between dammars and other types of plant resin, whatever their botanical origin. Such analyses provide clues for a precise identification (taxonomy, occurrence of other material in addition to the resin, alteration state) of unknown resinous material discovered in archaeological contexts. The value of our approach is illustrated by the taxonomic characterisation of two samples collected in jars from the Brunei wreck and a Chinese junk lost more than 40 km off the Sultanate of Brunei during the end of the fifteenth century or the early beginning of the sixteenth century.     

‘YOUTH RIOTS’ AND THE CONCEPT OF CONTENTIOUS POLITICS IN HISTORICAL RESEARCH

This article analyses European ‘youth riots’ as a social phenomenon after World War II. It also uses a specific riot – the 1948 Stockholm Easter Riots – in order to discuss the limits and potential of some theoretical assumptions underlying the field of historical contentious politics studies, primarily ‘contentious politics’ and ‘claims’. Using police reports and newspapers, the article shows that the riots were part of a European repertoire of post-war ‘youth riots’, but that they also bear similarities to an older popular repertoire of contention in Sweden. However, the riots do not really fit into the concept of ‘contentious politics’, as this concept is built on ‘claim-making’ as a key aspect and the participants did not make explicit claims. This leads to the conclusion that other theoretical tools, inspired by the concept of ‘moral economy’, are better suited for understanding the motivations of the rioters, whose actions are interpreted as a way of defending a perceived moral right of access to the urban public space.