In May 2012,the Emilia region of the Po Valley was struck by a seismic crisis with two major events of magnitude M_w 6.1and M_w 5.9.The first event induced widespread sand blows formed along buried channels and old cr...In May 2012,the Emilia region of the Po Valley was struck by a seismic crisis with two major events of magnitude M_w 6.1and M_w 5.9.The first event induced widespread sand blows formed along buried channels and old crevasse splay deposits.In the days immediately following the events,the detailed mapping and sampling of the erupted sand was fundamental to record all the seismically-induced phenomena.The study of a trench dug across large fractures at San Carlo(Ferrara)provided also valuable information on the sand blows mechanism and regome.The sedimentological and compositional characteristics of the fracture-filling materials indicate that the sands were erupted from a layer located between 6.8 and 7.5 m depth.Older and deeper Holocene and Pleistocene sand layers were not apparently involved in the liquefaction phenomena.展开更多
During the earthquake in Emilia(Italy) of 2012,ca.30 permanent GPS stations were in operation within a radius of about 100 km from the epicenter,each equipped with an antenna rigidly fixed to the host building and s...During the earthquake in Emilia(Italy) of 2012,ca.30 permanent GPS stations were in operation within a radius of about 100 km from the epicenter,each equipped with an antenna rigidly fixed to the host building and sampling the GPS signal at a high rate(〉 1 Hz).From the recording of the GPS measurements,the instantaneous displacements s(t) in the NorthSouth and East-West directions of the phase centers of the single GPS antennas at each permanent station during the most important seismic sequences were calculated in kinematic mode.Subsequently,for each of the two displacements considered as two distinct external forces,the elastic response spectra of the building were determined and from them the two periods of vibration T along two orthogonal directions coinciding with the walls of the building were extracted.The experimentally obtained periods of vibration were compared with those inferable from the technical literature.In this way,a sufficiently large sample was obtained per building type,geometry(square,rectangular,regular or irregular planimetry),height(from a minimum of 4 to a maximum of 20 m) and materials(masonry,reinforced concrete,etc.).From the computational point of view,the study confirmed that GPS is an emerging tool for monitoring dynamic displacements and the experimentally estimated value of T is always lower than the one estimated with the formulae reported in the literature.The limitations of the study lie in the impossibility to choose a priori the geometry and/or structural type of the building hosting the GPS station.展开更多
The paper presents a Precaution Index (P) developed to create an instrument to assess the potential risk related to the presence of pollution sources next to milk production farms. The methodology starts from the inve...The paper presents a Precaution Index (P) developed to create an instrument to assess the potential risk related to the presence of pollution sources next to milk production farms. The methodology starts from the inventory and geo-referencing of all pollution sources in an area, with the help of the multi-criteria decision analysis. Results are represented in a map of P, which highlights which areas are most at risk and need monitoring, and which pollutants may be involved. This may help in the early identification of emerging hazards to food safety. P was calculated for the milk production in an Italian region. Results show that 97% of the area is in a condition of minimum precaution that would be needed in controlling the safety of dairy products.展开更多
Airborne particulate matter(PM) containing fungal spores and pollen grains was sampled within a monitoring campaign of wheat threshing, plowing and sowing agricultural operations. Fungal spores and pollen grains wer...Airborne particulate matter(PM) containing fungal spores and pollen grains was sampled within a monitoring campaign of wheat threshing, plowing and sowing agricultural operations. Fungal spores and pollen grains were detected and identified on morphological basis. No studies were previously available about fungal spore and pollen content in agricultural PM in the Po Valley. Sampling was conducted in a Po Valley farmland in Mezzano(Ferrara, Italy). The organic particles collected were examined by scanning electron microscopy with energy dispersive X-ray spectrometer. Fungal spores and pollen grains were identified when possible at the level of species. The most frequent components of the organic particles sampled were spores of Aspergillus sp., which could represent a risk of developing allergies and aspergillosis for crop farmers.展开更多
文摘In May 2012,the Emilia region of the Po Valley was struck by a seismic crisis with two major events of magnitude M_w 6.1and M_w 5.9.The first event induced widespread sand blows formed along buried channels and old crevasse splay deposits.In the days immediately following the events,the detailed mapping and sampling of the erupted sand was fundamental to record all the seismically-induced phenomena.The study of a trench dug across large fractures at San Carlo(Ferrara)provided also valuable information on the sand blows mechanism and regome.The sedimentological and compositional characteristics of the fracture-filling materials indicate that the sands were erupted from a layer located between 6.8 and 7.5 m depth.Older and deeper Holocene and Pleistocene sand layers were not apparently involved in the liquefaction phenomena.
文摘During the earthquake in Emilia(Italy) of 2012,ca.30 permanent GPS stations were in operation within a radius of about 100 km from the epicenter,each equipped with an antenna rigidly fixed to the host building and sampling the GPS signal at a high rate(〉 1 Hz).From the recording of the GPS measurements,the instantaneous displacements s(t) in the NorthSouth and East-West directions of the phase centers of the single GPS antennas at each permanent station during the most important seismic sequences were calculated in kinematic mode.Subsequently,for each of the two displacements considered as two distinct external forces,the elastic response spectra of the building were determined and from them the two periods of vibration T along two orthogonal directions coinciding with the walls of the building were extracted.The experimentally obtained periods of vibration were compared with those inferable from the technical literature.In this way,a sufficiently large sample was obtained per building type,geometry(square,rectangular,regular or irregular planimetry),height(from a minimum of 4 to a maximum of 20 m) and materials(masonry,reinforced concrete,etc.).From the computational point of view,the study confirmed that GPS is an emerging tool for monitoring dynamic displacements and the experimentally estimated value of T is always lower than the one estimated with the formulae reported in the literature.The limitations of the study lie in the impossibility to choose a priori the geometry and/or structural type of the building hosting the GPS station.
文摘The paper presents a Precaution Index (P) developed to create an instrument to assess the potential risk related to the presence of pollution sources next to milk production farms. The methodology starts from the inventory and geo-referencing of all pollution sources in an area, with the help of the multi-criteria decision analysis. Results are represented in a map of P, which highlights which areas are most at risk and need monitoring, and which pollutants may be involved. This may help in the early identification of emerging hazards to food safety. P was calculated for the milk production in an Italian region. Results show that 97% of the area is in a condition of minimum precaution that would be needed in controlling the safety of dairy products.
文摘Airborne particulate matter(PM) containing fungal spores and pollen grains was sampled within a monitoring campaign of wheat threshing, plowing and sowing agricultural operations. Fungal spores and pollen grains were detected and identified on morphological basis. No studies were previously available about fungal spore and pollen content in agricultural PM in the Po Valley. Sampling was conducted in a Po Valley farmland in Mezzano(Ferrara, Italy). The organic particles collected were examined by scanning electron microscopy with energy dispersive X-ray spectrometer. Fungal spores and pollen grains were identified when possible at the level of species. The most frequent components of the organic particles sampled were spores of Aspergillus sp., which could represent a risk of developing allergies and aspergillosis for crop farmers.