Modeling and deterioration mapping of façades in historical urban context by close-range ultra-lightweight UAVs photogrammetry

Deterioration mapping of façades may be a challenging task in historical urban contexts, often characterized by narrow streets and tall buildings. In these situations, the application of Terrestrial Laser Scanning or Terrestrial Photogrammetry does not provide satisfactory results. Furthermore, the use of Unmanned Aerial Vehicles, the so-called “drones”, is generally forbidden in crowded places for safety reasons unless they are lighter than a weight imposed by the regulations in force in each country. This article presents the application of a very small and ultra-lightweight drone (less than 300 g) equipped with a low-cost camera, particularly suitable for operating in very narrow spaces. A close range photogrammetric survey performed to analyze a huge historical building façade in Bologna (Italy) pointed out a good accuracy level, confirmed by the validation of the results carried out by a 3D laser scanner survey. Moreover, a map of the degradation has been realized to support further restoration analysis, demonstrating that this low-cost, fast, and easy-to-use survey technique can be applied to other similar urban contexts at the same time.     

Dynamic One-Sided Out-Of-Plane Behavior of Unreinforced-Masonry Wall Restrained by Elasto-Plastic Tie-Rods

Past earthquakes have shown the high vulnerability of existing masonry buildings, particularly to out-of-plane local collapse mechanisms. Such mechanisms can be prevented if façades are restrained by tie rods improving the connections to perpendiculars walls. Whereas in the past only static models have been proposed, herein the nonlinear equation of motion of a monolithic wall restrained by a tie rod is presented. The façade, resting on a foundation and adjacent to transverse walls, rotates only around one base pivot and has one degree of freedom. Its thickness is explicitly accounted for and the tie rod is modeled as a linear elastic—perfectly plastic spring, with limited displacement capacity. The model is used to investigate the response to variations of wall geometry (height/thickness ratio, thickness), tie rod features (vertical position, length, prestress level), and material characteristics (elastic modulus, ultimate elongation, yield strength) typical of historical iron. The most relevant parameter is the steel strength, whereas other characteristics play minor roles allowing to recommend reduced values for pre-tensioning forces. The force-based procedure customary in Italy for tie design is reasonably safe and involves protection also against collapse, although probably not enough as desirable.     

Silences Broken,Silences Kept: Gender and Sexuality in African-American History

In 1989, Evelyn Brooks Higginbotham observed that African Americanists paid scant attention to issues of gender and women's historians typically ignored questions of race; she warned that this silence compromised the very analysis of US history. Much has changed since Higginbotham issued her cautionary words. Not only has Americanist literature on gender and race grown exponentially over the past ten years, African-Americanist gender historians have produced some of the most influential monographs and articles in their field. This article surveys a decade's worth of conceptual breakthroughs in African-Americanist historiography as it ponders the question of whether certain silences still remain.     

Cranial pathology of Ursus spelaeus ROSENMÜLLER & HEINROTH from Chateau Pignon,Basque Territories (Spain)

A complex lesion, on a skull of a female cave bear (Ursus spelaeus) associated with perforations of the frontal sinus is described. Paleopathological analysis suggests that the lesion is attributable to complex cranial trauma, probably complicated by an infection which appears to have occurred following a fight, most likely with another bear or, possibly, a cave lion (Panthera leo spelaea); at least one of the perforations observed on the skull may have been produced by the canine of a large carnivore. This hypothesis is supported by the frequent intraspecific aggressiveness documented in modern bears, and by evidence suggesting interspecific fights between cave bears and cave lions. The case is discussed in the light of other evidence reported in the literature. © 1998 John Wiley & Sons, Ltd.     

A non-invasive study of Roman Age mosaic glass tesserae by means of Raman spectroscopy

Ancient mosaic tesserae are a range of materials of very varied and complex nature, including pottery, stone and glass. Raman spectroscopy is a powerful tool for the analysis of all these kinds of materials. In the particular case of glasses, this technique can be used both for a study of surface weathering and for the characterization of bulk structure, but it has not yet been extensively used for the characterization of mosaic glass tesserae. We carried out Raman analyses on a set of Roman and Late Antiquity period mosaic glass samples, which allowed a good characterization of both the glass matrix and the crystalline inclusions. All the samples show the typical Raman signatures of soda-lime-silicate glasses. Several crystalline phases were also identified, being relics of raw materials used during the glass manufacturing process, such as quartz and feldspars, or linked to the glass color/opacification, such as bindheimite and cuprite. The analyses also led to the identification in some blue, turquoise and green tesserae of calcium antimonate, whose Raman signature has only recently been recognized in the scientific literature on mosaic glasses. Some emphasis is given to the analysis of red lead-containing tesserae, colored with Cu⁺ ions or even Cu⁰ (or Au⁰) metal nanoparticles. Samples with peculiar compositions, as well as “modern” (and restoration) samples, could quite easily be distinguished from the ancient ones by their Raman spectra.     

Identifying foreigners versus locals in a burial population from Nasca, Peru: an investigation using strontium isotope analysis

During the several thousand years of human occupation in the Nasca drainage on the south coast of Peru, population movement into and out of the region impacted the formation and organization of society, as well as contributed to major cultural transformations. This study identifies foreign versus local individuals through the investigation of burial practices and strontium isotope analysis of human remains from the sites of La Tiza and Pajonal Alto dating from the Early Intermediate Period through the Late Intermediate Period (A.D. 1–1476). Of the ten samples analyzed, two individuals dating to the Middle Horizon were identified as foreigners. One of these individuals was buried in a new elite tomb type providing additional evidence that the Wari state incorporated Nasca into its realm. Two headless individuals, one dating to Middle Nasca with clear evidence of decapitation, and another dating to the Late Intermediate Period who was likely decapitated, were both locals. This suggests the practice of decapitation took place among local groups, and that the practice of decapitation and the use of heads as ritual items or trophies may have continued later in time than previously thought.     

Comparative Seismic Risk Assessment of Basilica-type Churches

ABSTRACT

This paper discusses the seismic risk assessment of a Basilica-type church according to the provisions of the Italian Guidelines. A comparison between the results obtained with local and global approaches is reported, based on a knowledge process aimed to characterize the geometric and mechanical parameters required for a reliable structural analysis. To perform the global analyses the finite element technique was employed, with proper assumptions to account for the nonlinear behavior of masonry. Illustrating a case study, the paper critically discusses about the employability of pushover analysis methods for the seismic assessment of basilica-type churches.     

Bearing capacity assessment of a 14th century arch bridge in Lecco (Italy)

The article presents the results of an experimental and numerical investigation on Azzone Visconti bridge, a 14th century arch bridge in Lecco (northern Italy). Starting from the historical data and from an extensive mechanical characterization of both the soil constituting the riverbed and of the masonry constituting the piers, the aim of the study is to investigate the bearing capacity of the bridge. A testing loading scheme defined according to the current Italian Code is adopted to check the structural behavior. A simplified finite element structural model was conceived and calibrated as a control tool to safely perform the experimental tests. Post-test nonlinear finite element analyses have allowed the prediction of the bridge bearing capacity and the definition of the bridge class according to the Italian regulations.     

Regulation,integration and sustainability in the cultural sector

The paper examines the hypothesis of vertical integration between heritage and the performed arts. This is often a response to scarcity, and in many cases it implies conversion of heritage back to its original function. Various issues arise, due to the dilemma given by the potential cost for future generations of a more intensive present exploitation. On the other hand, many benefits are likely to be generated on cultural, economic and financial grounds. Furthermore, the decision‐making processes become quite complex, and adequate changes in regulation are necessary in order to make such a vertical integration consistent with culturally sustainable growth.