1,721,047 research outputs found
Groundwater hydrogeochemical changes predating and following the November 9, 2022 Mw 5.5 Adriatic offshore earthquake (central Italy)
No full textWe report the results from a pre- and post-seismic water monitoring carried out in the Mt. Conero area (central Italy) to evaluate the earthquake-related variations on the water hydrogeochemistry related to the November 9, 2022 Adriatic offshore seismic sequence. This latter was characterized by two main events of Mw 5.5 and 5.2. The monitoring network included two wells and one piezometer located at ∼50 km from the earthquake epicentre. The wells did not show relevant changes. Contrarily, the piezometer showed an overwhelming variation in its composition and Total Dissolved Solids (TDS) since four months before the mainshock, shifting from a low-salinity (TDS 3500 mg/L) sodium-chloride composition. Then, composition and TDS were restored about a week after the events. These changes were accompanied by strong increases in trace elements concentrations (e.g., B, Mn), which returned to the pre-seismic values in the days following the mainshock. The strong hydrogeochemical variations recorded at the piezometer were likely related with two different seismically-induced processes linked to a mixing between shallow Ca-HCO3 and deep Na-Cl waters, and the bedrock’s fracture unclogging. These variations are, to the best of our knowledge, among the largest ever observed before a seismic event or, at least, ever reported in the literature. These results prove hydrogeochemical monitoring for seismic surveillance can be highly effective. Besides, our work represents a further step in the development of a methodology that could potentially track geochemical changes ahead of larger, potentially dangerous earthquakes
Insights into the Porretta Terme (northern Apennines, Italy) hydrothermal system revealed by geochemical data on presently discharging thermal waters and paleofluids
Full text linkThis study focuses on the geochemical features of the presently discharging thermal and cold springs and on paleofluids from the upstream portion of the Reno river basin (Alto Reno; central–northern Italy). The aim is investigating the primary sources of the modern and fossil fluids and the interactions between deep and shallow aquifers. Paleofluids are from fluid inclusions hosted within euhedral and hopper quartz crystals and consist of a two-phase, liquid–vapor aqueous fluid and a unary CH4 fluid. The aqueous inclusions have constant phase ratios and a calculated salinity of ~ 1.5 wt% NaCleq. They homogenize by bubble disappearance at 100–200 °C, whereas the estimated entrapment depth is ~ 3–5.5 km. The paleofluids likely represent the vestiges of the deep and hot, CH4-rich, Na+–Cl− fluids produced by the interaction between meteoric waters and Triassic and Miocene formations. The modern Na+–Cl−(HCO3−) thermal waters originate from meteoric waters infiltrating SW of the study area, at elevation > 800 m a.s.l., circulating within both the Triassic evaporites and the overlying Miocene turbiditic formations, where salt dissolution/precipitation, sulfate reduction, and production of thermogenic CH4 occur. The equilibrium temperature of the deep fluid source is ~ 170 °C, corresponding to > 5 km depth. Cold springs are Ca2+–HCO3− type and show low amounts of biogenic CO2 and CH4 with no inputs of deep-originated fluids excepting in the immediate surroundings of the thermal area, confirming the lack of significant hydraulic connection between shallow and deep aquifers. We propose a genetic link between the quartz-hosted paleofluid and the thermal waters present in the area
Assessment, control, and prevention of microbiological and chemical hazards in seasonal swimming pools of the Versilia district (Tuscany, central Italy)
No full textAlthough in Europe the quality of swimming pools (SPs) is dictated by regulations, microbiological and chemical hazards are described in the literature. Environmental bacteria or toxic disinfection byproduct (DBP) compounds may indeed be recovered in waters even after disinfection. We evaluated the water quality from 26 outdoor seasonal SPs of the Versilia district, according to requirements of Regional Decree 54R/2015. In spring 2017, supply and reinstatement waters were collected after shock hyperchlorination (10 mg/L) while in summertime, a second sampling of waters before entering the pools, as well as in the pools, was performed after SPs were open to the public. In all samples, microbiological and chemical parameters were determined as defined by Directive 98/83/EC and the Italian Health Ministry. Microbiological data were within suggested limits. The first chemical analyses showed that in 35% of the feeding-pool seawater samples, the halogenated organic compounds were higher than the maximum permissible concentrations (30 μg/L). Pool waters were then dechlorinated and re-treated with hydrogen peroxide (10 mg/L) to ensure the abatement of DBPs (from 164 ± 107 to 0.9 ± 0.8 μg/L; p 1⁄4 0.002). Results highlighted the need of self-controlled procedures for the SPs waters to prevent waterborne diseases and suggested hydrogen peroxide as the most appropriate disinfection method
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Hydrogeochemistry of the groundwater system in the Mt. Catria-Mt. Nerone carbonate ridge (northern Marche, central Italy)
No full textThe Mt. Catria-Mt. Nerone (northern Marche, central Italy) carbonate ridge contains a defined and isolated hydrogeological system composed by three main sedimentary aquifers hosted in the Scaglia, Maiolica and Massiccio Formations. These calcareous and marly-calcareous aquifers belong to the Umbria-Marche series and are divided by marly and marly-clayey aquicludes. The groundwaters from the Mt. Nerone-Mt. Catria calcareous formations represent the main water supply for 360k inhabitants of the Province of Pesaro-Urbino. Despite the social and economic importance of these water reservoirs, the scientific knowledge is rather scarce (e.g., Bison et al., 1995; Capaccioni et al., 2001). Therefore, in this study the number of sampling points (31) as well as that of analysed geochemical parameters (i.e., major and trace solutes, water stable isotopes and dissolved gases) was implemented with respect to previous investigations, in order to better characterize the geochemical composition of the waters discharging in the area. The aims were to (i) define the main geochemical processes, (ii) understand the hydrogeological pathways and fluid circulation patterns and (iii) assess the quality of these waters. The waters can be classified into four different groups: (a) Ca-HCO3 waters with TDS 1100 mg/L); (d) Na-HCO3 waters with pH > 9 and negative Eh values. The isotopic values of hydrogen and oxygen clearly indicate a meteoric origin for these waters. The composition of Ca-HCO3 waters is almost exclusively related to the dissolution of carbonate-bearing formations, whereas those showing an SO4-enrichment (up to 200 mg/L) suggested a deeper circulation and the interaction with the gypsum-anhydrite formation (i.e., Burano Formation). The Ca-SO4 waters are related to a deep circulation within the Messinian formations. Finally, the Na-HCO3 waters are due to long-lasting interactions between meteoric waters and Na-rich silicate rocks (e.g., Marnoso-Arenacea Formation) in saturation/oversaturation conditions for carbonate-bearing minerals. The dissolved gases of Na-HCO3 waters are enriched in CO2 and CH4, whose source is likely pertaining to layers characterized by a higher content of organic matter where anaerobic degradation occurs
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Il mercurio gassoso (Hg0) nella ex-zona mineraria di Abbadia San Salvatore (Mt. Amiata, Siena) ed in aree vulcaniche attive e quiescenti: distribuzione e comportamento in relazione ad altri inquinanti atmosferici
No full textDispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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