The seismic performance of stone masonry buildings is known to be generally poor with respect to other structural typologies. However, significant differences can be observed for different ...architectural configurations, structural details and masonry mechanical properties. In particular, the seismic vulnerability of existing stone masonry structures is often governed by local failure modes, typically consisting of out-of-plane overturning of structural portions or crumbling of outer wythes in multi-leaf walls. In buildings with an adequate masonry quality, an overall behaviour controlled by the in-plane capacity of walls can develop and govern the global failure mode, provided that proper connections between perpendicular walls and between walls and floors are effective in contrasting the activation of early local failures. In these cases, the in-plane stiffness of diaphragms (typically vaults and timber floors/roofs) can play a significant role in coupling the response of the different walls, hence controlling the global building capacity. Recent experimental testing campaigns carried out in different laboratories have focused on several aspects of the seismic response of stone masonry buildings and on the effect of several strengthening techniques. The availability of such experimental results allowed validation and improvement of analysis tools and procedures for the assessment of the seismic capacity of existing stone masonry structures. In order to make them available to all practitioners, the research achievements need to be incorporated in codes and guidelines for the assessment and strengthening of existing stone masonry buildings. The procedures currently proposed in several codes are already based on a rational approach, which starts from the acquisition of an adequate structural knowledge level and allows for using nonlinear analysis procedures. They could straightforwardly include new research findings and practical developments.
Protected areas (PAs) are key elements for biodiversity conservation and ecosystem services. Brazil has the largest PA system in the world, covering approximately 220 million ha. This system expanded ...rapidly in the mid‐1990s to the mid‐2000s. Recent events in Brazil, however, have led to an increase in PA downgrading, downsizing, and degazettement (PADDD). Does this reflect a shift in the country's PA policy? We analyzed the occurrence, frequency, magnitude, type, spatial distribution, and causes of changes in PA boundaries and categories in Brazil. We identified 93 PADDD events from 1981 to 2012. Such events increased in frequency since 2008 and were ascribed primarily to generation and transmission of electricity in Amazonia. In Brazilian parks and reserves, 7.3 million ha were affected by PADDD events, and of these, 5.2 million ha were affected by downsizing or degazetting. Moreover, projects being considered by the Federal Congress may degazette 2.1 million ha of PA in Amazonia alone. Relaxing the protection status of existing PAs is proving to be politically easy in Brazil, and the recent increase in frequency and extension of PADDD reflects a change in governmental policy. By taking advantage of chronic deficiencies in financial and personnel resources and surveillance, disputes over land tenure, and the slowness of the Brazilian justice, government agencies have been implementing PADDD without consultation of civil society. If parks and reserves are to maintain their integrity, there will need to be investments in Brazilian PAs and a better understanding of the benefits PAs provide. Degradación, Reajuste, Eliminacióm de las Listas y Reclasificación de Áreas Protegidas en Brasil
Over the last decades, consumer´s preference for and their attention to food products presented as healthy and with favorable nutritional information has been significantly increased. In this line, ...both the addition of dietary fiber and the incorporation of probiotic strains in the elaboration of fermented meat products has been established as a useful tool for the development of healthy products. Thus, the aim of this review is to present an overview of the studies involving fermented meat products with added dietary fiber and probiotic microorganisms, and also, to discuss about some of the challenges regarding the reformulation of this innovative product category.
The interest on novel biological preservation methods has been increasing during recent years, supported by research indicating that antagonistic microorganisms and their antimicrobial metabolites ...may have some potential use as natural preservatives as a way not only to control the growth but also to inactivate undesired microorganisms in food. Biopreservation using lactic acid bacteria (LAB) and/or their antimicrobial metabolites represents an alternative for improving food safety. These antimicrobial properties of LAB were derived from competition for nutrients and the production of one or more antimicrobial active metabolites such as organic acids (mainly lactic and acetic acid), hydrogen peroxide and also other compounds, such as bacteriocins and antifungal peptides. The important contribution of probiotic LAB in food preservation has been attracting much attention because of the nutritional qualities of the raw material through an extended shelf life of food and their ability to inhibit spoilage and foodborne pathogens, which is interesting for the food industry. In this review, we compiled the available data on the commonly used preservative and present the current knowledge regarding the antimicrobial compounds, especially bacteriocins, the mechanisms of the action and recent applications of antimicrobial compounds in food. The use of competitive microbiota as a biotechnological tool for food preservation may lead to improve the optimization and quality assurance of food products while at the same time retaining the sensory qualities of the product such as color, flavor, texture and nutritional value.
Post-earthquake damage data represent an invaluable source of information for the seismic vulnerability assessment of the exposed building stock, as they are a direct evidence of the actual ...buildings’ performance under real seismic events. This paper exploits a robust and homogeneous database of damage data collected after the 2009 L’Aquila (Italy) earthquake, to derive damage probability matrices for several building typologies representative of the Italian building stock. To this aim, the first part of the work investigates several issues related to the definition of damage to be associated with each inspected building. Different approaches and damage conversion rules are applied, pointing out advantages and weaknesses of each one. Considering the widespread seismic damage observed on masonry infill panels and partitions of reinforced concrete constructions, the impact of this type of non-structural damage on empirical damage and functional loss distributions is explored. The second part of the study proposes different possible interpretations of the repartition of the observed damage in the different damage levels, showing in some cases a bimodal trend. Two novel hybrid procedures are outlined and compared with the classical binomial approach for predicting the subdivision of damage in the different levels. The application of the proposed methodologies to the different building typologies allows the selection, for each one, of the method providing the best fit to empirical results. The parameters required for the application of the optimal approach are reported in the paper, so that results can be used for forecasting the expected seismic damage in sites with similar seismic hazard and exposed buildings.
Gas atomized Ti–48Al–2Cr–2Nb powders have been used as precursor material in order to evaluate additive manufacturing for the production of near-net-shape γ-TiAl specimens to be employed in the field ...of aero-engines. In particular electron beam melting (EBM) is used to realize a selective densification of metal powder by melting it in a layerwise manner following a CAD design. The microstructure, the residual porosity and the chemical composition of the samples have been investigated both immediately after EBM and after heat treatments. High homogeneity of the samples, very low pickup of impurities (oxygen and nitrogen) with respect to the starting powders have been observed and due to an extremely low level of internal defects, intrinsic to EBM process, the tensile properties of the EBM γ-TiAl appear very consistent with a small scatter.
► We investigated the fabrication of gamma-TiAl by electron beam melting. ► High microstructure homogeneity. ► Low level of defects. ► Very small scatter of material mechanical properties.
A new analytical approach for the derivation of fragility curves for masonry buildings is proposed. The methodology is based on nonlinear stochastic analyses of building prototypes. Since such ...structures are assumed to be representative of wider typologies, the mechanical properties of the prototypes are considered as random variables, assumed to vary within appropriate ranges of values. Monte Carlo simulations are then used to generate input variables from the probability density functions of mechanical parameters. The model is defined and nonlinear analyses are performed. In particular, nonlinear static (pushover) analyses are used to define the probability distributions of each damage state whilst nonlinear dynamic analyses allow to determine the probability density function of the displacement demand corresponding to different levels of ground motion. Convolution of the complementary cumulative distribution of demand and the probability density function of each damage state allows to derive fragility curves.
In this paper, empirical fragility curves for reinforced concrete buildings are derived, based on post-earthquake damage data collected in the aftermath of earthquakes occurred in Italy in the period ...1976–2012. These data, made available through an online platform called Da.D.O., provide information on building position, building characteristics and damage detected on different structural components. A critical review of this huge amount of data is carried out to guarantee the consistency among all the considered databases. Then, an in-depth analysis of the degree of completeness of the survey campaign is made, aiming at the identification of the Municipalities subjected to a partial survey campaign, which are discarded from fragility analysis. At the end of this stage, only the Irpinia 1980 and L’Aquila 2009 databases are considered for further elaborations, as fully complying with these criteria. The resulting database is then integrated with non-inspected buildings sited in less affected areas (assumed undamaged), to account for the negative evidence of damage. The PGA evaluated from the shakemaps of the Italian National Institute of Geophysics and Volcanology (INGV) and a metric based on six damage levels according to EMS-98 are used for fragility analysis. The damage levels are obtained from observed damage collected during post-earthquake inspections through existing conversion rules, considering damage to vertical structures and infills/partitions. The maximum damage level observed on vertical structures and infills/partitions is then associated to the whole building. Fragility curves for two vulnerability classes, C2 and D, further subdivided into three classes of building height, are obtained from those derived for specific structural typologies (identified based on building height and type of design), using their frequency of occurrence at national level as weights.
•A dataset collecting the results of 188 in-plane cyclic tests on URM piers has been developed.•Different masonry typologies constituted by bricks and blocks are included.•A preliminary investigation ...on the in-plane lateral strength and displacement capacity has been performed.•Some inconsistencies between code criteria and experimental evidence have been pointed out.•The dataset provides a tool available for future studies on the in-plane response of URM piers.
In this paper, a dataset collecting the results of in-plane cyclic tests on unreinforced masonry piers, carried out within different research projects, is presented. The dataset includes brick and block walls with different materials, bed-and head-joint typologies, dimensions, boundary conditions and vertical applied loads. The development of such dataset aims at providing a tool for the improvement of the understanding and the evaluation of the main parameters that may influence and govern the lateral response of the URM piers under seismic excitation. A preliminary investigation on the in-plane lateral strength and displacement capacity, being two of the most significant parameters used in seismic analyses for the design and assessment of masonry buildings, has been proposed. The dataset, that already groups several specimens, is freely shared and might be continuously updated. This source of information of consistent and reliable test results represents a necessary step into the process of definition of shared rules within the scientific and technical community, in particular for the improvement of codified criteria, analytical and numerical models and testing procedures.
This paper focuses on the in-plane behaviour of rubble stone masonry with lime mortar strengthened with different solutions. For that, 12 rubble stone masonry wall specimens, with construction ...features typical of ancient historic buildings of Southern Portugal and Mediterranean countries, were subjected to in-plane quasi-static cyclic tests. The applied retrofit solutions are specific for historic masonry buildings, such as the injection of mortar and FRCM systems, with glass and carbon meshes. The main experimental results obtained are presented through envelope curves, in terms of resistance, deformation capacity, and deformed shapes. Moreover, dissipated energy is also commented on. Horizontal drift results are compared and analysed together with the ones obtained in the literature for equivalent strengthening solutions in masonry walls.
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