Often in abandoned mine sites are present both underground voids produced by mining and the tailings of treatment plant.An interesting solution for the rehabilitation of the sites would be to place the tailings of the...Often in abandoned mine sites are present both underground voids produced by mining and the tailings of treatment plant.An interesting solution for the rehabilitation of the sites would be to place the tailings of the process in the underground mining voids,thus obtaining the reclamation of surface areas and the stabilization of abandoned voids to prevent the dangerous phenomena of subsidence.However,these operations require inert waste,which must not be source of pollution,and the choice of a water/solid optimum to ensure good conditions of pumpability.展开更多
Soil flushing technology is an ＇in situ＇ remediation technique involving the injection of a liquid solution. Applications of the soil flushing technique depend on the leachability of the pollutants and the environme...Soil flushing technology is an ＇in situ＇ remediation technique involving the injection of a liquid solution. Applications of the soil flushing technique depend on the leachability of the pollutants and the environmental compatibility and total volumes of the solutions used. Therefore, experiments should consider these aspects by simulating the real phenomenon and using the most suitable reagents for the leachability of the different mineralogical forms present. Thirty- one laboratory tests were carried out （in batch and becker） to the complete exhaustion of the leaching capacity according to pH measurements. The reaction kinetics were studied by producing more than 300 solution samples during which the principal heavy metal concentrations, pH and Eh were measured. Leaching solutions containing various concentrations of hydrochloric, sulphuric, nitric and acetic acids were used. Mercury was leached using potassium iodide and acetic acid （pH 2）. Analytes such as arsenic, cadmium, mercury, lead, selenium and zinc proved to be leachable in the investigated soil layer. However, high removal efficiencies could be obtained using different typological solutions, concentrations and volumes. The paper discusses the applicability of the soil flushing technique for different heavy metal contents and pH conditions of the flushing solution.展开更多
At the base of the reflection developed in this research work, there is the concept of habitat as a system, as an articulated ＂whole＂ that cannot be explained with the simple sum of its parts. The concept of habitat...At the base of the reflection developed in this research work, there is the concept of habitat as a system, as an articulated ＂whole＂ that cannot be explained with the simple sum of its parts. The concept of habitat, in fact, implies issues of dialectic spaces, in other words, those settings that can be defined as relational subsystems within the urban/domestic scale. This essay has its roots in the CIAM （Congr^s International d＇Architecture Moderne （in English： International Congress of Modem Architecture）） of 1953, during which the complementarity of the outside space next to the dwelling and its relevance within the project discipline, have been affirmed. In particular, assimilating the lesson of Aldo van Eyck, this work investigates the deepest issues of the concept of threshold. The analysis makes use of the work-tools of critical reading and comparison between urban and rural habitats, with different density levels, whose relational fabrics have been layering over time permeable ＂thicknesses＂ which articulate complex threshold spatial configurations.展开更多
Arteries devoted to sustain streams of users, resources and debris, are a foremost factor and pre-condition of the development of urban areas and of the transformation of landscapes. Roadscapes reflect outcomes relate...Arteries devoted to sustain streams of users, resources and debris, are a foremost factor and pre-condition of the development of urban areas and of the transformation of landscapes. Roadscapes reflect outcomes related to super urbanization tendencies. Often conceived as isolated tubes, roads cut and obscure form, structure, biotic and abiotic factors of sites, urban fabrics and spaces. A broad vision of landscape is a basis for reconceiving roads. The concept of road-spine emerges： the road is conceived as the basis of a bundle of routes, nodes, surfaces, poles and tiles, devised to frame and shape a mosaic of open spaces, crops, farms, stores, basins and service areas. The road-spine entails the idea of a permeable infrastructure devised to integrate diverse functions： from serving various forms of motion, by ordering an isotropic grid of routes, to framing a porous urbanscape; from disposing surfaces meant to preserve biocenosis and biotopes, to favoring osmosis amid land uses. It also prefigures a distribution of land uses dependent on site vocations, and a mosaic of scenarios open to encounter, evasion, rest, amusement, participation, and to spontaneous practices of space.展开更多
Societa Nazionale Officine di Savigliano was a company specialized in railway constructions, metallic bridges and mechanical and electrical constructions. Between the end of the 19th century and the beginning of the 2...Societa Nazionale Officine di Savigliano was a company specialized in railway constructions, metallic bridges and mechanical and electrical constructions. Between the end of the 19th century and the beginning of the 20th century, the company became well known in Europe especially for metallic constructions, having built the majority of metal bridges in the north of Italy such as the famous Paderno bridge （1887-1889）, one of the biggest arch bridge for the period. In the 1930s, the company built some interesting examples of steel frame buildings, applying the electrical welding technique, acquired in industrial constructions, to civil buildings. The steel frame was quite rare in Italian buildings, especially in the matter of civil constructions and Savigliano made an effort in modernizing the Italian construction system, through research and innovation. The paper will discuss some examples of Savigliano＇s works dating back to 1930, and in particular, it will present a specific example never studied before： the hangar at the Elmas military airport, in Cagliari （Sardinia）. The building is worth mentioning for the innovations experimented, as the new welding technique allowed a series of improvements in the construction process.展开更多
This paper reports on the current state of an ongoing research project which is aimed at implementing intelligent models for hardly predictable hazard scenarios identification in construction sites. As any programmati...This paper reports on the current state of an ongoing research project which is aimed at implementing intelligent models for hardly predictable hazard scenarios identification in construction sites. As any programmatic actions cannot deal with the unpredictable nature of many risk dynamics, an attempt to improve the current approach for safety management in the construction industry will be presented in this paper. To this aim, the features offered by Bayesian networks have been exploited. The present research has led to the definition of a probabilistic model using elicitation techniques from subjective knowledge. This model, which might be meant as a reliable knowledge map about accident dynamics, showed that a relevant part of occurrences fall in the ＂hardly predictable hazards＂ category, which cannot be warded off by programmatic safety measures. Hence, more effort turned out to be needed in order to manage those hardly predictable hazardous scenarios. Consequently, further developments of this research project will focus on a real time monitoring system for the identification of unpredictable hazardous events in construction.展开更多
This article presents the results of experimental studies concerning the dynamic deformation and failure of a unidirectional carbon fiber reinforced plastic(T700/LY113)under compression.The test samples were manufactu...This article presents the results of experimental studies concerning the dynamic deformation and failure of a unidirectional carbon fiber reinforced plastic(T700/LY113)under compression.The test samples were manufactured through the filament winding of flat plates.To establish the strain rate dependencies of the strength and elastic modulus of the material,dynamic tests were carried out using a drop tower,the Split Hopkinson Pressure Bar method,and standard static tests.The samples were loaded both along and perpendicular to the direction of the reinforcing fiber.The applicability of the obtained samples for static and dynamic tests was confirmed through finite elementmodeling and the high-speed imaging of the deformation and failure of samples during testing.As a result of the conducted experimental studies,static and dynamic stress-strain curves,time dependencies of deformation and the stress and strain rates of the samples during compression were obtained.Based on these results,the strain rate dependencies of the strength and elasticity modulus in the strain rate range of 0.001-6001/s are constructed.It is shown that the strain rate significantly affects the strength and deformation characteristics of the unidirectional carbon fiber composites under compression.An increase in the strain rate by 5 orders of magnitude increased the strength and elastic modulus along the fiber direction by 42%and 50%,respectively.Perpendicular loading resulted in a strength and elastic modulus increase by 58%and 50%,respectively.The average strength along the fibers at the largest studied strain rate was about 1000MPa.The obtained results can be used to design structural elements made of polymer composite materials operating under dynamic shock loads,as well as to build models of mechanical behavior and failure criteria of such materials,taking into account the strain rate effects.展开更多
Olive Mill Solid Wastes (OMSW) released in nature without any treatment is a major environmental problem in the Mediterranean region. In this work, the catalyzed pyrolysis of OMSW has been investigated. A catalyst bas...Olive Mill Solid Wastes (OMSW) released in nature without any treatment is a major environmental problem in the Mediterranean region. In this work, the catalyzed pyrolysis of OMSW has been investigated. A catalyst based on SBA-15 mesoporous silica doped with chromium ferrite nanoparticles was prepared by the double solvent technique (DS). The prepared catalyst was characterized by scanning electron microscopy (SEM), Wide and Small Angle X-ray Scattering (WAXS, SAXS), Energy Dispersive X-ray (EDX) and FT-IR spectroscopies. Reverse spinel chromium ferrite nanoparticles were located inside the SBA-15 pores as confirmed by SEM images. The obtained catalyst was tested for pyrolysis reactions of OMSW. Several parameters were studied to optimize the conditions of the pyrolysis reaction in order to increase the bio-oil conversion yield. The GC-MS results demonstrated that the quality of the obtained bio-oil was improved by decreasing the quantity of phenolic and oxygenated components as well as the size of the obtained molecules. The produced bio-oil from pyrolysis of OMSW is identical to that obtained from the pyrolysis of commercial cellulose under the same conditions. A 37% conversion yield of bio-oil was obtained for the best conditions.展开更多
文摘Often in abandoned mine sites are present both underground voids produced by mining and the tailings of treatment plant.An interesting solution for the rehabilitation of the sites would be to place the tailings of the process in the underground mining voids,thus obtaining the reclamation of surface areas and the stabilization of abandoned voids to prevent the dangerous phenomena of subsidence.However,these operations require inert waste,which must not be source of pollution,and the choice of a water/solid optimum to ensure good conditions of pumpability.
文摘Soil flushing technology is an ＇in situ＇ remediation technique involving the injection of a liquid solution. Applications of the soil flushing technique depend on the leachability of the pollutants and the environmental compatibility and total volumes of the solutions used. Therefore, experiments should consider these aspects by simulating the real phenomenon and using the most suitable reagents for the leachability of the different mineralogical forms present. Thirty- one laboratory tests were carried out （in batch and becker） to the complete exhaustion of the leaching capacity according to pH measurements. The reaction kinetics were studied by producing more than 300 solution samples during which the principal heavy metal concentrations, pH and Eh were measured. Leaching solutions containing various concentrations of hydrochloric, sulphuric, nitric and acetic acids were used. Mercury was leached using potassium iodide and acetic acid （pH 2）. Analytes such as arsenic, cadmium, mercury, lead, selenium and zinc proved to be leachable in the investigated soil layer. However, high removal efficiencies could be obtained using different typological solutions, concentrations and volumes. The paper discusses the applicability of the soil flushing technique for different heavy metal contents and pH conditions of the flushing solution.
文摘At the base of the reflection developed in this research work, there is the concept of habitat as a system, as an articulated ＂whole＂ that cannot be explained with the simple sum of its parts. The concept of habitat, in fact, implies issues of dialectic spaces, in other words, those settings that can be defined as relational subsystems within the urban/domestic scale. This essay has its roots in the CIAM （Congr^s International d＇Architecture Moderne （in English： International Congress of Modem Architecture）） of 1953, during which the complementarity of the outside space next to the dwelling and its relevance within the project discipline, have been affirmed. In particular, assimilating the lesson of Aldo van Eyck, this work investigates the deepest issues of the concept of threshold. The analysis makes use of the work-tools of critical reading and comparison between urban and rural habitats, with different density levels, whose relational fabrics have been layering over time permeable ＂thicknesses＂ which articulate complex threshold spatial configurations.
文摘Arteries devoted to sustain streams of users, resources and debris, are a foremost factor and pre-condition of the development of urban areas and of the transformation of landscapes. Roadscapes reflect outcomes related to super urbanization tendencies. Often conceived as isolated tubes, roads cut and obscure form, structure, biotic and abiotic factors of sites, urban fabrics and spaces. A broad vision of landscape is a basis for reconceiving roads. The concept of road-spine emerges： the road is conceived as the basis of a bundle of routes, nodes, surfaces, poles and tiles, devised to frame and shape a mosaic of open spaces, crops, farms, stores, basins and service areas. The road-spine entails the idea of a permeable infrastructure devised to integrate diverse functions： from serving various forms of motion, by ordering an isotropic grid of routes, to framing a porous urbanscape; from disposing surfaces meant to preserve biocenosis and biotopes, to favoring osmosis amid land uses. It also prefigures a distribution of land uses dependent on site vocations, and a mosaic of scenarios open to encounter, evasion, rest, amusement, participation, and to spontaneous practices of space.
文摘Societa Nazionale Officine di Savigliano was a company specialized in railway constructions, metallic bridges and mechanical and electrical constructions. Between the end of the 19th century and the beginning of the 20th century, the company became well known in Europe especially for metallic constructions, having built the majority of metal bridges in the north of Italy such as the famous Paderno bridge （1887-1889）, one of the biggest arch bridge for the period. In the 1930s, the company built some interesting examples of steel frame buildings, applying the electrical welding technique, acquired in industrial constructions, to civil buildings. The steel frame was quite rare in Italian buildings, especially in the matter of civil constructions and Savigliano made an effort in modernizing the Italian construction system, through research and innovation. The paper will discuss some examples of Savigliano＇s works dating back to 1930, and in particular, it will present a specific example never studied before： the hangar at the Elmas military airport, in Cagliari （Sardinia）. The building is worth mentioning for the innovations experimented, as the new welding technique allowed a series of improvements in the construction process.
文摘This paper reports on the current state of an ongoing research project which is aimed at implementing intelligent models for hardly predictable hazard scenarios identification in construction sites. As any programmatic actions cannot deal with the unpredictable nature of many risk dynamics, an attempt to improve the current approach for safety management in the construction industry will be presented in this paper. To this aim, the features offered by Bayesian networks have been exploited. The present research has led to the definition of a probabilistic model using elicitation techniques from subjective knowledge. This model, which might be meant as a reliable knowledge map about accident dynamics, showed that a relevant part of occurrences fall in the ＂hardly predictable hazards＂ category, which cannot be warded off by programmatic safety measures. Hence, more effort turned out to be needed in order to manage those hardly predictable hazardous scenarios. Consequently, further developments of this research project will focus on a real time monitoring system for the identification of unpredictable hazardous events in construction.
基金This research was supported by the Russian Science Foundation(Grant No.21-19-00563,https://rscf.ru/en/project/21-19-00563/)H.M.Sedighi is grateful to the Research Council of Shahid Chamran University of Ahvaz for its financial support(Grant No.SCU.EM1401.98)。
文摘This article presents the results of experimental studies concerning the dynamic deformation and failure of a unidirectional carbon fiber reinforced plastic(T700/LY113)under compression.The test samples were manufactured through the filament winding of flat plates.To establish the strain rate dependencies of the strength and elastic modulus of the material,dynamic tests were carried out using a drop tower,the Split Hopkinson Pressure Bar method,and standard static tests.The samples were loaded both along and perpendicular to the direction of the reinforcing fiber.The applicability of the obtained samples for static and dynamic tests was confirmed through finite elementmodeling and the high-speed imaging of the deformation and failure of samples during testing.As a result of the conducted experimental studies,static and dynamic stress-strain curves,time dependencies of deformation and the stress and strain rates of the samples during compression were obtained.Based on these results,the strain rate dependencies of the strength and elasticity modulus in the strain rate range of 0.001-6001/s are constructed.It is shown that the strain rate significantly affects the strength and deformation characteristics of the unidirectional carbon fiber composites under compression.An increase in the strain rate by 5 orders of magnitude increased the strength and elastic modulus along the fiber direction by 42%and 50%,respectively.Perpendicular loading resulted in a strength and elastic modulus increase by 58%and 50%,respectively.The average strength along the fibers at the largest studied strain rate was about 1000MPa.The obtained results can be used to design structural elements made of polymer composite materials operating under dynamic shock loads,as well as to build models of mechanical behavior and failure criteria of such materials,taking into account the strain rate effects.
文摘Olive Mill Solid Wastes (OMSW) released in nature without any treatment is a major environmental problem in the Mediterranean region. In this work, the catalyzed pyrolysis of OMSW has been investigated. A catalyst based on SBA-15 mesoporous silica doped with chromium ferrite nanoparticles was prepared by the double solvent technique (DS). The prepared catalyst was characterized by scanning electron microscopy (SEM), Wide and Small Angle X-ray Scattering (WAXS, SAXS), Energy Dispersive X-ray (EDX) and FT-IR spectroscopies. Reverse spinel chromium ferrite nanoparticles were located inside the SBA-15 pores as confirmed by SEM images. The obtained catalyst was tested for pyrolysis reactions of OMSW. Several parameters were studied to optimize the conditions of the pyrolysis reaction in order to increase the bio-oil conversion yield. The GC-MS results demonstrated that the quality of the obtained bio-oil was improved by decreasing the quantity of phenolic and oxygenated components as well as the size of the obtained molecules. The produced bio-oil from pyrolysis of OMSW is identical to that obtained from the pyrolysis of commercial cellulose under the same conditions. A 37% conversion yield of bio-oil was obtained for the best conditions.
