1,165 research outputs found

    Effect of injection depth of digestate liquid fraction on soil carbon dioxide emission and maize biomass production

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    The aim of this study was to evaluate, in open field conditions, the effect of injection depth of digestate liquid fraction (10 cm, 25 cm and 35 cm) in clay loam soil, on CO2 emission. An un-amended soil was considered as control. The study was performed in 2014 on a farm located in Terrasa Padovana, Veneto region (Italy) distributing digestate before maize sowing. Digestate injection determined a high soil CO2 emission in the first hour after application, followed by a progressive reduction in as early as 24 h, reaching significantly lower values, similar to those measured in the un-amended control, after 48 h. Gas emissions measured 1 h after digestate application decreased as injection depth increased with significantly higher emission values in the 10 cm treatment (median value 23.7 g CO2 m\u20132 h\u20131) than in the 35 cm one (median value 2.5 g CO2 m\u20132 h\u20131). In the 3 days between digestate distribution and maize sowing, soil CO2 emission was significantly higher in the amended treatments than un-amended one, with median values of 1.53 g CO2 m\u20132 h\u20131 and 0.46 g CO2 m\u20132 h\u20131 respectively. During maize growing season, no significant soil CO2 emission difference was monitored among treatments, with a median value of 0.33 g CO2 m\u20132 h\u20131. Digestate application significantly improved maize aboveground dry biomass with an average yield of 22.0 Mg ha\u20131 and 16.2 Mg ha\u20131 in amended and un-amended plots, respectively, due to the different amount of nutrients supplied

    On the value of water quality observations for karst model parameterization

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    If properly applied, karst hydrological models are a valuable tool for karst water resources management. If they are able to reproduce the relevant flow and storage processes of a karst system, they can be used for prediction of water resources availability when climate or land use are expected to change. A common challenge to apply karst simulation models is the limited availability of observations to identify their model parameters. In this study, we quantify the value of information added to parameter estimation when water quality data (NO3 and SO4) is used in addition to discharge observations to estimate the parameters of a process-based karst simulation model at a test site in Southern Spain. We use a three-step procedure (1) to confine an initial sample of 500,000 model parameter sets, (2) to identify alterations of individual model parameters through the confinement, and (3) to quantify the strength of the confinement for each of the model parameters. The last step allows us to quantify the information content of hydrodynamic and water quality observations for model parameter estimation. Our results show that NO3 provides most information to identify the model parameters controlling soil and epikarst dynamics, while discharge observations provide most information about the recharge area and the groundwater dynamics. SO4 mostly contributes to the identification of recharge processes. Looking at different flow states of the system, we also find that information provided by our observations varies over time.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    Karst flow system information from shape analysis and numerical modeling of tracer concentration curves

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    Dye tracing constitute a very valuable tool for investigating the origin of groundwater and delineating flowpaths in karst media, providing direct and quantitative information about the hydraulic properties and solute transport dynamic within a conduit (and/or fracture) dominated system. In this sense, data obtained from 8 single- and multi-injection tracer experiments performed during last years in different carbonate aquifers located in Malaga province (southern Spain) have been re-examined following the numerical solutions provided by a dual process-based approach: advection–dispersion model (ADM) and two-region non-equilibrium model (2RNE). Tracer tests were conducted under different hydrological conditions (high-intermediate-low flow) affecting the aquifers, and the fluorescent substances were injected into sinkholes (5), losing streams (4), karrenfields (1) and dolines (1), while springs commonly served as detection points (manual sampling and eventually field fluorimeters). Flow and transport parameters estimates obtained from the simulation of 13 tracer breakthrough curves (BTCs) provided mixed information on a wide range of hydrogeological behaviors: from well-developed conduit flow paths to flow and storage modalities in a fissured-like systems. The statistical treatment of the analytical and numerical results, jointly to the field observations, has been especially useful for the characterization of the predominant solute transport processes in the studied experimental sites, given the significant deviations that have been eventually found between the shape of the measured and modeled curves (marked skewness, single/multi-pulse geometry, long-tailing effect, etc). These findings will allow for a better understanding of the structure and dynamic of the karst systems investigated and will may help to protect and preserve karst water resources in the region.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    Coupling hydro-geo-chemical and isotopic approaches to assess the main factors controlling karst development in a fissure-dominated carbonate aquifer system (s-Spain)

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    Sierra Tejeda, Almijara and Albuñuelas mountains comprise a large outcrop (750 km² ca) of Triassic marbles in between of Málaga and Granada provinces in S Spain. They constitute a large entity carbonate aquifer system providing strategic groundwater resources for drinking water supply in sparse urban settlements and crops irrigation. The present research aims to refine the current hydrogeological knowledge of large-scale fissure-dominated carbonate aquifers regarding flow mechanisms and geochemical processes defining observed groundwater quality. To this, a two-year monitoring program of aquifer dynamics have been conducted in three selected discharge points (Fájara, Cijancos and Maro springs) showing characteristic spring responses. A combined approach based on the analysis of spring discharge and time series of selected hydrochemical and isotopic tracers (Na+, Ca+2, Mg+2, TA, TOC, Cl-, SO4-2 and δ13CTDIC) and on the geochemical calculations from the chemical signature of spring waters have been followed. The results indicate that the more bicarbonate enriched waters and the lowest hydrochemical variability of Cijancos spring, practically in all analyzed solutes, denotes a fissure type dominant flow system, while the larger variations in meteoric/soil tracers (Cl- and TOC) observed in Fajara spring chemograph as consequence of rainfall inputs characterize a karst drainage from a better hierarchized fracture-enlarged flow system. Maro spring waters are rich in Na+, Ca+2, Cl- and SO4-2, have higher δ13CTDIC amplitude and the temporal variations of major ions display marked dilutions after rainfall events followed by rapid recoveries of pre-event concentrations, evidence a complex flow system and variable groundwater source contribution. The chemical reactions deduced from the molar ratios of spring water chemistry are commonly CO2 dissolution and calcite dissolution, but also salt evapoconcentration in soil layer and gypsum dissolution in the case of Maro spring.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    Role of C3 plant species on carbon dioxide and methane emissions in Mediterranean constructed wetland

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    C3 plant species are widely used to vegetate constructed wetlands (CW), but so far no information is available on their effect on CW CO 2(eq) balance in the Mediterranean climate. The aim of this research was to study carbon dioxide (CO 2 ) and methane (CH 4 ) emissions and CO 2(eq) budgets of CW horizontal sub-surface flow pilot-plant beds vegetated with Arundo donax L. and Phragmites australis (Cav.) Trin. ex Steud. compared with an unvegetated bed in Sicily. The highest total plant biomass production was measured in the bed vegetated with A. donax (17.0 kg m –2 ), whereas P. australis produced 7.6 kg m –2 . CO 2 and CH 4 emissions and showed significant correlation with average air temperature and solar radiation for each bed. The CO 2 emission values ranged from 0.8±0.1 g m –2 d –1 , for the unvegetated bed in April, to 24.9±0.6 g m –2 d –1 for the bed with P. australis in August. The average CO 2 emissions of the whole monitored period were 15.5±7.2, 15.1±7.1 and 3.6±2.4 g m –2 d –1 for A. donax , P. australis and unvegetated beds respectively. The CH 4 fluxes differed significantly over the monitored seasons, with the highest median value being measured during spring (0.963 g m –2 d –1 ). No statistical differences were found for CH 4 flux among the studied beds. Cumulative estimated CH 4 emissions during the study period (from April to December) were 159.5, 134.1 and 114.7 g m –2 for A. donax , P. australis and unvegetated beds respectively. CO 2(eq) balance showed that the two vegetated beds act as CO 2(eq) sinks, while the unvegetated bed, as expected, acts as a CO 2(eq) source. Considering only the above-ground plant biomass in the CO 2(eq) budgets, P. australis and A. donax determined uptakes of 1.30 and 8.35 kg CO 2(eq) m –2 respectively

    SAPIENT-Simulator Modelling and Architecture

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    Future aeronautical communications will be based on the TCP/IP protocol stack, and will occur through a number of different data-link channels (e.g., satellite, terrestrial), with multipath capabilities – the so-called multilink. Seamless vertical handover between different data-links is a requirement and it will improve the safety and reliability of AEROCOM systems, possibly enabling remote-piloted aircrafts (RPAs) for civil operations. This paper describes the modelling, design and implementation of an AEROCOM system simulator based on OMNeT++, developed in the framework of the SAPIENT EU project. The simulator includes models of the aircrafts, including their mobility, terrestrial and satellite data links and core network. Moreover, it includes a solution to simulate the effect of multilink capabilities, which enables one to test multilink decision policies

    A Cross-Sectional Survey on Burnout Prevalence and Profile in the Sicilian Population of Ambulance Driver-Rescuers

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    Introduction: Burnout is present at a high rate in emergency medicine. The ambulance driver-rescuers, who furnish first aid to the victims, are the non-medical part of the Italian 118-service staff. There is a lack of research on burnout risk in Italian Emergency Medical Services and, particularly, for this category of workers. The two Italian studies, including a little group of ambulance driver-rescuers, reported inconsistent findings. Hypothesis: This survey investigated for the first time the prevalence and exact profile of burnout in a large sample of Italian driver-rescuers. As a secondary aim, the study described how the items of the Italian version of the Maslach Burnout Inventory-Human Services Survey (MBI-HSS) cluster in components in this sample. Methods: This cross-sectional census survey was conducted from June 2015 through May 2016 and involved all the driver-rescuers operating in Sicily, the biggest and most southern region of Italy. The subjects received a classification according to different profiles of burnout by using the Italian version of the MBI-HSS (burnout, engagement, disengagement, over-extension, and work-inefficacy). In order to explore the existence of independent factors, a Principal Component Analysis (PCA) was conducted on the survey to obtain eigenvalues >one for each component in the data. Results: The final sample comprised 2,361 responders (96.6% of the initial sample). Of them, 29.8% were in burnout (95% confidence interval [CI], 27.8% to 31.8%) and 1.7% presented a severe form (95% CI, 1.1% to 2.3%); 30.0% were engaged in their work (95% CI, 21.0% to 34.8%), 24.7% of responders were disengaged (95% CI, 22.9% to 26.5%), 1.2% presented an over-extension profile (95% CI, 0.8% to 1.7%), and 12.6% felt work-inefficacy (95% CI, 11.3% to 14.1%). The factors loaded into a five-factor solution at PCA, explaining 48.1% of the variance and partially replicating the three-factor structure. The Emotional Exhaustion (EE) component was confirmed. New dimensions from Personal Accomplishment (PA) and Depersonalization (DP) sub-scales described empathy and disengagement with patients, respectively, and were responsible for the increased risk of burnout. Conclusions: These results endorse the importance of screening and psychological interventions for this population of emergency workers, where burnout could manifest itself more insidiously. It is also possible to speculate that sub-optimal empathy skills could be related to the disengagement and work-inefficacy feelings registered

    Las proteinas foliares en nutrición animal : contribución a su estudio en alimentación aviar

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    Tesis Univ. Complutense de Madrid.ProQuestSección Dptal. de Nutrición y Ciencia de los Alimentos (Veterinaria)Fac. de VeterinariaTRUEpu
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