Application of Non-Destructive Techniques in the Inspection of Wooden Structures of Protected Buildings: The Case of Nuestra Señora de los Dolores Church (Isla Cristina,Huelva)

This study describes a thorough inspection of a 20th century church in the town of Isla Cristina (in the province of Huelva, southwestern Spain), which is currently awaiting restoration. The study indicates the damage processes at work in the building structure materials (brick, concrete, steel, and wood), which are closely related to its geographical location, and analyses the deterioration of the wooden roof structure. The analysis of the wooden roof includes the results of an inspection methodology on a protected building based on traditional techniques such as visual inspection and innovative non-destructive inspection techniques (visual classification, ultrasounds and thermography). Fieldwork consisted of the visual classification of the wooden pieces according to Spanish standard UNE 56544:2007 specifications after which ultrasound and thermography techniques were applied on-site. A second stage involved laboratory tests (anatomic identification, density and bending strength) using wood samples extracted from the structure in order to check the values for the physical and mechanical properties previously recorded by non-destructive techniques (NDT). These non-destructive techniques are used in inspections of the wooden roofs of buildings to identify dampness, deterioration, density loss and defects as a means of assessing their conservation status. This work concludes that the use of ultrasound and thermography techniques constitute an accurate diagnostic tool for the on-site inspection of wooden structures and the evaluation of their condition. Thermography identifies different materials and moisture content while ultrasound detects the various degrees of deterioration and density-loss in areas of the wood with high moisture content.     

Canada–Mexico Relations: Interdependence,Shared Values … and the Limits of Cooperation

This article offers a historical overview of the evolution of the relationship between Canada and Mexico, emphasizing its exiguity, its fundamental economic nature and the consequences of sharing borders with the United States. It is organized as follows: the first section covers the period going from the establishment of diplomatic relations in 1944 to the late 1960s, a period during which the bilateral relation failed to consolidate despite sporadic efforts; the second section deals with the period starting with the convergence of political visions in the two capitals in the early 1970s up to the period immediately preceding the starting of the negotiations leading to NAFTA. The period during which the most significant engagement between the two countries has taken place to the present is reviewed in the third section. The article concludes presenting some thoughts on the possibilities and limits of cooperation between the two countries.