1,720,992 research outputs found
Soundscape Perception in Cagliari, Italy
No full textIn order to study how acoustic and visual stimuli can influence the perception of the landscape, six
Soundscapes and six corresponding Visual Landscapes typical of Cagliari, the capital city of Sardinia, have been
selected and characterized through a binaural phonometric sampling and a photographic survey. All 36 possible
combinations were submitted to a panel of 107 subjects. The evaluations expressed for the audio/visual associations
highlighted how the combination of two different sensorial stimuli gives a wider basis of judgment to the
interviewed subjects. The correspondence analysis, through the recognition of common perceptive patterns in the
acoustic sensitivity of the local citizens, showed how the sound, more than the image, was the predominant element
in the construction of their judgments. The analysis, moreover, singled out some decision parameters in the
pleasantness assigned, discriminating the natural environments from the urban ones; the Hi-fi landscapes from the
Lo-fi ones; the hi-Leq events from the low-Leq ones. This method suggests some requisites for drawing up an
Acoustic Improvement Plan or land planning measures in general that involves the perceptive dimension of the
community, particularly the auditory one, in the organization of space
Conoscenza, progetto e tutela del complesso edilizio fortificato "Castello di Pitino" sito nel comune di San Severino Marche (MC)
No full textIl Castello medievale di Pitino (sec. XI-XIII), in comune di San Serverino Marche, si presta ad un intervento conservativo con uso innovativo degli spazi per migliorare la fruibilità dei beni culturali locali. Costruito in pietra concia locale e malta e ancora munito con una torre alta 23 m, può essere valorizzato tramite la sua posizione dominante isolata lungo la stada Septempedana, diverticolo della Salaria molto usato durante l'alto medioevo e attualmente in corso di ripristino per agevolare le connessioni stradali Adriatico-Tirreno
Environmental management and metal recovery: re-processing of mining waste at Montevecchio site (SW Sardinia)
No full textThe paper illustrates and discusses an innovative approach in the reclamation of old mining areas, which is inspired by the circular economy principle and considers the waste of old mining and mineral processing activities as secondary potential raw materials. The European Union legislation has been encouraging this type of practice, which is receiving full recognition from the international scientific literature as well. The application of the mining waste treatment as a reclamation technique is mostly based on the flotation technique that proved to be useful for separating the remaining minerals from the gangue. This provides both an environmental benefit and an economic advantage, which in some cases repays the re-processing costs, even though several difficulties could be encountered in the application of flotation to mining waste. The paper presents the results of the experimental laboratory batch tests, which proved to be encouraging in the case of the Montevecchio mining district (SW Sardinia). Nevertheless, future work is needed to clarify that they are valid for the different situations present on the site
Mitigation of fugitive dust impact arising from BR dry disposal
Full text linkThe 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
Recupero di specie utili dai residui minero-metallurgici: potenzialità e problematiche della situazione in Sardegna
Full text linkThe paper discusses the hypothesis of reprocessing of mineral waste according to the following items: general distribution in Sardinia; distribution of Pb and Zn mining wastes in the Sulcis Iglesiente Guspinese; results of the first batch flotation tests. The application of the mining waste treatment as a reclamation technique is mostly based on the flotation technique that proved to be useful for separating the remaining minerals from the gangue. This provides both an environmental benefit and an economic advantage, which in some cases repays the reprocessing costs, even though several difficulties could be encountered in the application of flotation to mining waste. The paper presents the results of the experimental laboratory batch tests, which proved to be encouraging in the case of the Montevecchio mining district (SW Sardinia). Nevertheless, future work is needed to clarify, as much they are valid for the different situations present on the site
Visual impact evaluation of mines and quarries: the updated Lvi method
Full text linkThe article deals with the evaluation of the visual impact arising from quarrying, mining and civil engineering works that involve extensive surface excavation. An indirect method has been formerly proposed to quantify the Level of visual impact (Lvi) based on the two physical variables that define the magnitude of change in a natural landscape: the solid angle subtended by the visible alteration from a given viewpoint (Ωv) and the chromatic contrast between the alteration and the surrounding landscape (ΔEμ). These two objective variables are determined by elaborating the digital images of the landscape under investigation, taken from the most representative viewpoints. The Lvi indicator has proven to be highly correlated with the judgement values expressed by potential observers and thus may represent a valuable operative tool in the Environmental Impact Assessment (EIA) procedures, both for the proponent of new projects and for the governmental authorities in charge of decision-making. This article describes a further development of the Lvi method, which aims at improving the repeatability of the impact evaluation by eliminating some critical issues related to the definition of both the excavation limits and the natural comparison surfaces representing the natural landscape. To that end, the original calculation code has been implemented with two image segmentation algorithms, which objectively designate the areas within the picture to be used for the automatic calculation of the impact level Lvi. The updated code has been validated against the original Lvi method, thus confirming the suitability of the revised methodology to represent the perception of potential observers
Characterization of erodible surfaces with an environmental wind tunnel
Full text linkThe article illustrates the design and the main characteristics of the Environmental Wind Tunnel (EWT) recently built in the laboratories of Cagliari University (DICAAR). The aim of the EWT is the simulation of a part-depth Atmospheric Boundary Layer (ABL) and thus the reproduction of the wind flow over any type of surface. Experimental tests are currently being performed to analyse the correlation between the emission of dust from a variety of erodible samples and the influencing physical parameters (moisture content, percentage of silt, particles density and wind speed). The final aim of the ongoing research is the definition of reliable Emission Factors (EFs) to represent the contribution of tailing basins, mine dumps and stockpiles to the overall emission of particulate matter (PM) from industrial sites and open yards exposed to wind erosion (industrial wind erosion)
The flotation of sphalerite mine tailings as a remediation method
No full textSphalerite tailings are the most important type of waste in the mining district of Sardinia. This situation justifies the interest in the applicability of flotation as a remediation technique by which declassify the tailings (reducing the concentration of heavy metals). The flotation of mine tailings represents a novelty if aimed at environmental remediation. Instead, it is a widespread industrial practice for recovering secondary raw materials. In this case, the scientific aspects are rarely explored: this situation explains the limited number of cases examined, the review of which, however, represents a necessary premise for the research undertaken. Furthermore, the availability of industrial case demonstrates reprocessing is not only a technically possible process but also of economic interest. After an overview of the environmental problem in abandoned mining areas, the paper recalls the fundamental elements useful for developing a comparison between the main operating methods adopted in the flotation of Pb and Zn sulphides, both as primary ores (high and low Zn content) and as tailings. The case history also includes the treatment of Zn oxidized compounds. The comparison demonstrates that the treatment of sphalerite tailings can follow the same approach as that of low-grade primary ores, but with evident economic advantages, and allows achieving those, far greater, of the multiple environmental effects
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