Laredo, Texas: Gateway Community on the Texas Borderlands, Archaeological and Historical Investigations for the Laredo City Toll Plaza

In July 1980, the Center for Archaeological Research, The University of Texas at San Antonio, conducted archaeological and historical investigations at sites designated as 41 WB 36,41 WB 37, and 41 WB 38, which are located in a residential district on the east side of the town of Laredo, Texas. These sites are represented by late historic foundations which were uncovered after a group of houses were razed to make way for a new toll bridge complex to facilitate international travel between the United States and the Republic of Mexico. A short history of Laredo and of the four house foundations excavated by the Center for Archaeological Research is presented in this report. The archaeological investigations of the structures and their associated artifacts are described and interpreted to provide a better understanding of sociocultural activities in Laredo from early historic times to the present

Linking nitrogen cycling transformations to microbial diversity in freshwater ecosystems

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Diseño del puente Abbas Ibn Firnás sobre el río Guadalquivir en Córdoba

The work for the New Access to the Cordoba Airport includes the construction of the Abbas Ibn Firnas Bridge to cross the Guadalquivir River. This cable-stayed bridge has two spans of 132.50 m each, and three approach spans on the right bank that add 100 meters to its length. The most important and singular aspect of the structure is the design of the mixed concrete and steel arches that open into two hexagonal tubes braced from the central pier to the abutments and the arrangement of the struts made up of closed cables in the form of a “Y” creating a spatial structure of great slenderness and stiffness, a three-dimensional structure that contains the traffic within, and dignifies the urban space over the Guadalquivir River.Las obras del Nuevo Acceso al Aeropuerto de Córdoba incluyen la construcción del Puente Abbas Ibn Firnás para salvar el cauce del río Guadalquivir. Se trata de un puente arco atirantado de dos vanos, con 132,50 m de luz cada uno con tres vanos de aproximación por la margen derecha que suman una longitud de 100 metros. El aspecto más relevante y singular de la estructura es el diseño de los arcos mixtos, que se abren en dos tubos hexagonales arriostrados, desde la pila central hacia los estribos, y la disposición de tirantes constituidos por cables cerrados en forma de “Y” que permite que se consiga una estructura espacial, un objeto tridimensional de gran esbeltez y rigidez, que acoge en su interior la circulación viaria, y dignifica el espacio urbano sobre el Guadalquivir