Non-ergodic site response model based on local recordings for Menta Dam site

The paper describes the development of a non-ergodic site response model for a strategic site in the Aspromonte mountains, in Southern Italy. Fractured metamorphic rocks belonging to Calabrian complex outcrop in this area, located in a region where Southern Apennines crustal faults and subduction of the Calabrian Arc contribute to the seismic hazard. At the site, three accelerometers are installed since 2016 as part of the monitoring system of the Menta Dam, a bituminous-faced rockfill dam constructed for the water supply of the region. Ground motions recorded at the site and elsewhere from regional crustal and subduction earthquakes have been used to evaluate region-specific source and path adjustment to global ground motion models (GMMs). Those regionally adjusted GMMs have, in turn, been used to evaluate the mean bias of site-specific recordings, which is used to estimate non-ergodic site response for the dam site. This analysis highlights that site-specific site response is appreciably larger than the global average prediction of GMMs for periods lower than 0.4s. A non-ergodic GMM is developed that accounts for these effects to be used in subsequent Probabilistic Site Hazard Analysis (PSHA)

Structure and Morphology of Silver Nanoparticles on the (111) Surface of Cerium Oxide

The structure of Ag nanoparticles of different size, supported on the cerium oxide (111) surface, was investigated by X-ray absorption fine structure at the Ag K-edge. The results of the data analysis in the near and extended energy range are interpreted with the help of the results obtained by X-ray photoelectron spectroscopy and scanning tunneling microscopy measurements and allow to obtain a detailed atomic scale description of the model system investigated. The Ag nanoparticles have an average size of a few tens of angstroms, which increases with increasing deposited Ag amount. The nanoparticles show a slight tendency to nucleate at the step edges between different cerium oxide layers and they have a face centered cubic structure with an Ag-Ag interatomic distance contracted by 3-4% with respect to the bulk value. The interatomic distance contraction is mainly ascribed to dimensionality induced effects, while epitaxial effects have a minor role. The presence of Ag-O bonds at the interface between the nanoparticles and the supporting oxide is also detected. The Ag-O interatomic distance decreases with decreasing nanoparticle size

QTL mapping for brown rot (Monilinia fructigena) resistance in an intraspecific peach (Prunus persica L. Batsch) F1 progeny

Brown rot (BR) caused by Monilinia spp. leads to significant post-harvest losses in stone fruit production, especially peach. Previous genetic analyses in peach progenies suggested that BR resistance segregates as a quantitative trait. In order to uncover genomic regions associated with this trait and identify molecular markers for assisted selection (MAS) in peach, an F1 progeny from the cross "Contender" (C, resistant) 7 "Elegant Lady" (EL, susceptible) was chosen for quantitative trait loci (QTL) analysis. Over two phenotyping seasons, skin (SK) and flesh (FL) artificial infections were performed on fruits using a Monilinia fructigena isolate. For each treatment, infection frequency (if) and average rot diameter (rd) were scored. Significant seasonal and intertrait correlations were found. Maturity date (MD) was significantly correlated with disease impact. Sixty-three simple sequence repeats (SSRs) plus 26 single-nucleotide polymorphism (SNP) markers were used to genotype the C 7 EL population and to construct a linkage map. C 7 EL map included the eight Prunus linkage groups (LG), spanning 572.92 cM, with an average interval distance of 6.9 cM, covering 78.73 % of the peach genome (V1.0). Multiple QTL mapping analysis including MD trait as covariate uncovered three genomic regions associated with BR resistance in the two phenotyping seasons: one containing QTLs for SK resistance traits near M1a (LG C 7 EL-2, R2 = 13.1-31.5 %) and EPPISF032 (LG C 7 EL-4, R2 = 11-14 %) and the others containing QTLs for FL resistance, near markers SNP_IGA_320761 and SNP_IGA_321601 (LG3, R2 = 3.0-11.0 %). These results suggest that in the C 7 EL F1 progeny, skin resistance to fungal penetration and flesh resistance to rot spread are distinguishable mechanisms constituting BR resistance trait, associated with different genomic regions. Discovered QTLs and their associated markers could assist selection of new cultivars with enhanced resistance to Monilinia spp. in fruit

Seismic Vulnerability of a Rockfill Dam through Different Displacement-based Approaches

The paper focuses on the assessment of the seismic performance of Menta Dam, a bituminous faced-rockfill dam located in Southern Italy. The dam was designed in the ‘70s and a comprehensive assessment of hydraulic and seismic vulnerability has been recently performed according to most recent Italian dam regulations. The present work aims at predicting the displacement capacity of the embankment as an indicator to assess the overall seismic vulnerability of the system. To this aim, different displacement-based methods, which can be classified in the framework of simplified dynamic analyses, have been applied. The results of empirical approaches and of Newmark’s type dynamic analyses are compared to the ones obtained by a novel application of Direct Displacement-Based Assessment (DDBA) method for embankment structures. The latter approach seems to be promising, since it is capable to furnish the maximum displacement experienced by the dam crest for progressively increasing seismic actions, and its probability of exceedance; hence, the likelihood of reaching a threshold damaged condition can be deduced and usefully plotted in terms of fragility curves