Characterization of Oxidized Zinc (Calamine) Ores by Scanning Electron Microscopy and Electron Microprobe Analysis

Textural and structural features of Sardinian oxidized zinc (calamine) ores have been established by scanning electron microscopy and electron microprobe analysis, the elements analyzed being Zn, Pb, Ca and Fe. The surface composition of grains produced by comminution has also been determined, especially with reference to the presence of smithsonite and cerussite. The methodological approach adopted has revealed intimate intergrowth of the mineral species present and contamination of the main mineral by inclusions of other species, which explains why it is so difficult to obtain good recoveries and high-quality concentrates by beneficiation processes

Mineral Recognition and Liberation Degree Measurements in Industrial Ore Processing

This study aims at identifying calculation procedures and representation methods for identifying the mineral species present in a rock. The goal of the study is to identify: the characteristic spectrum for each mineral species identified in the ore; the main shape of the individual species; the preferential arrangement of the individual mineral species; the grain-size distribution of the individual mineral species and of the grains resulting from comminution processes; the degree of liberation for each mineral; and the degree of liberation of the comminution products obtained from the ores

Who should pay for interdependent risk? Policy implications for security interdependence among airports

We study interdependent risks in security, and shed light on the economic and policy implications of increasing security interdependence in presence of reactive attackers. We investigate the impact of potential public policy arrangements on the security of a group of interdependent organizations, namely, airports. Focusing on security expenditures and costs to society, as assessed by a social planner, to individual airports and to attackers, we first develop a game‐theoretic framework, and derive explicit Nash equilibrium and socially optimal solutions in the airports network. We then conduct numerical experiments mirroring real‐world cyber scenarios, to assess how a change in interdependence impact the airports' security expenditures, the overall expected costs to society, and the fairness of security financing. Our study provides insights on the economic and policy implications for the United States, Europe, and Asia

PM emissions from a BR basin and impact assessment on air quality

The article deals with the emission of fugitive dust from a major BR (Bauxite Residue) basin located in the south-west of Sardinia, where the prospect of a change in the storage practices is likely to cause the increase of PM (Particulate Matter) pollution in the surrounding region. In fact, other natural and anthropic sources already provide a variable contribution in terms of airborne dust concentration in the same territory. In accordance with the procedures established by the Directive 2011/92 (EIA Directive - Environmental Impact Assessment), the data recorded by a monitoring network located in the SulcisIglesiente sub-region has been taken into consideration in order to define the ante-operam condition of the potential impact area. The additional contribution of the red mud basin has been simulated with the atmospheric dispersion model proposed by US EPA (Environmental Protection Agency). The expected whole concentration of the PM10, which includes both the pre-existing sources and the additional contribution of the red mud basin, has been estimated and compared with the limit values established by the Directive 2008/50/EC (Ambient air quality and cleaner air for Europe)

Mitigation of fugitive dust impact arising from BR dry disposal

The development of international policies about environmental defense has enforced some major modifications in the management of industrial tailings. As regards the disposal of the residue deriving from the bauxite processing (BR) in the alumina industry, national and international regulations have encouraged the evolution from wet to dry disposal techniques. However, such a change in the storage practices poses a major concern due to the potential increase of the atmospheric impact in the surrounding areas, due to the emissions of Particulate Matter (PM) generated both by the BR disposal activities and by the wind erosion over the dried surfaces of the landfill. The article analyses the effect of the impact mitigation measures typically adopted to control PM emissions with reference to a major red mud basin located in the southwest of Sardinia (Italy). The PM dispersion models performed with the CALPUFF code (US EPA) allowed, for the case study under consideration, the estimate of the improvement provided by moistening the dry surfaces and reducing the total length travelled par year by the machinery involved in material handling, transportation and disposal

Is the Salmonella contamination of swine carcasses at slaughter related to the Salmonella load in caecum?

The aim of this study was to examine the relationship between the load of Salmonella spp. in caeca and the carcass contamination in an Italian slaughterhouse. The sampling scheme was designed to be representative of the pigs slaughtered in a day and to estimate a 12% prevalence of pigs highly contaminated by Salmonella spp. (HCP, cecal load ≥3log). Environmental swabs were taken before slaughter. Cecal contents and carcass swabs were collected from the same pig. Salmonella MPN were estimated according to ISO6579- 2:2012/A1 and ISO7218:2007/E. The overall Salmonella prevalence were 34.64% and 7.19% for ceca and carcasses respectively, with S. Derby and S. 4,[5],12:i:- being the prevalent serotypes. The HCP prevalence was 11.44%. 7/59 environmental swabs tested positive; when the same serotype was isolated from the environment and from carcasses, the samples were excluded from further analysis. Statistical analysis was performed to investigate the relationship between Salmonella spp. loads in the cecum and contamination of the carcass of the same pig and the prevalence of HCP and the contamination of carcasses on the same day. For this purpose, the days were classified as “high prevalence days” depending on the proportion of caeca resulted positive (≥36%) and as “high load” days depending on the prevalence of HCP (≥10%). A correlation between the contamination of carcasses and the cecal Salmonella loads of the same animal was found (Spearman’s correlation coefficient: 0.2254; p-value=0.0001). No correlation was found between the contamination of carcasses and the categorization of the day of sampling as “high prevalence day”. Conversely, a correlation was found between the contamination of carcasses and the “high load” category of the sampling day (Wilcoxon test, p=0.0011). Notably, not the prevalence of pigs carrying Salmonella spp. but the prevalence of highly contaminated pigs was shown to be related to the contamination of carcasses

Identifying Implicit Vulnerabilities through Personas as Goal Models

When used in requirements processes and tools, personas have the potential to identify vulnerabilities resulting from misalignment between user expectations and system goals. Typically, however, this potential is unfulfilled as personas and system goals are captured with different mindsets, by different teams, and for different purposes. If personas are visualised as goal models, it may be easier for stakeholders to see implications of their goals being satisfied or denied, and designers to incorporate the creation and analysis of such models into the broader RE tool-chain. This paper outlines a tool-supported approach for finding implicit vulnerabilities from user and system goals by reframing personas as social goal models. We illustrate this approach with a case study where previously hidden vulnerabilities based on human behaviour were identified

On the Security Cost of Using a Free and Open Source Component in a Proprietary Product

The work presented in this paper is motivated by the need to estimate the security effort of consuming Free and Open Source Software (FOSS) components within a proprietary software supply chain of a large European software vendor. To this extent we have identified three different cost models: centralized (the company checks each component and propagates changes to the different product groups), distributed (each product group is in charge of evaluating and fixing its consumed FOSS components), and hybrid (only the least used components are checked individually by each development team). We investigated publicly available factors (\eg, development activity such as commits, code size, or fraction of code size in different programming languages) to identify which one has the major impact on the security effort of using a FOSS component in a larger software product