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Suppression Of underwater Noise Induced by Cavitation: project deliverable D1.1
No full textThe work documented herein concerns the research activity undertaken by CNR INSEAN about the development, assessment and application of non-conventional experimental approaches and methodologies to investigate underwater noise phenomena. The survey was carried out in the Large Cavitation Channel of CNR INSEAN. Main results and conclusions of the experimental work are summarized as follows: - Cavitation observations and acoustic measurements for a reference test case represented by a scale model of the STREAMLINE tanker. A comprehensive analysis of the radiated underwater noise and cavitation characteristics was performed at three different acceleration rates of the vessel and at different levels of the static pressure in the facility. Cavitation phenomena appear more intense when the blade is run over the hull perturbation and in the region where the hydrodynamic loads are largest. Acoustic tests highlighted an evident effect of the cavitation noise at the propeller speeds of 10rps and 12rps when the static pressure is dropped down below 106mbar and 173mbar. Depending on both cavitation characteristics, the corresponding distributions of the SPL are characterized by the increase of the broadband contribution in the mid and high frequency range as well as by a significant increase of the tonal contribution at the BPF . - Background noise removal technique to filter out the contribution of extraneous noise source contributions from the "true" hydroacoustic perturbation. The methodology, which consists of a spectral conditioning technique among correlated inputs, was tested using the STREAMLINE tanker in absence of propeller as test case and returned an attenuation by about 5dB and 10db in correspondence of the peaks at 100 and 400Hz. The effectiveness of the background noise removal procedure has been observed to be strongly influenced by the accuracy at which the background noise is measured. - Separation of the acoustic and hydrodynamic contributions from near field pressure fluctuation measurements to allow a detailed analysis of the mechanism underlying the hydrodynamic and hydroacoustic perturbations. The methodology is based upon near field pressure fluctuation measurements and wavelet-based post-processing techniques. The technique was applied to the study of the acoustic and hydrodynamic perturbations in the STREAMLINE tanker and highlighted the occurrence of distinct mechanisms behind the hydrodynamic and acoustic pressure fluctuations
Presenza e distribuzione di batteri antibiotico-resistenti nelle acque del Lago Maggiore
Get PDFNot availableRicerche sull\u27evoluzione del Lago Maggiore. Aspetti limnologici. Programma triennale 2013-2015. Campagna 2013. Presenza e distribuzione di batteri antibiotico-resistenti nelle acque del Lago Maggiore. Valutazione della presenza di geni di antibiotico-resistenza (ABR). Quantificazione dei geni di resistenza alle tetracicline
Ricerche sull\u27evoluzione del Lago Maggiore. Aspetti limnologici. Programma triennale 2013-2015. Campagna 2013
Get PDFNot availableRicerche sull\u27evoluzione del Lago Maggiore. Aspetti limnologici. Programma triennale 2013-2015. Campagna 201
A proposito di acqua: la newsletter del CNR Istituto per lo Studio degli Ecosistemi di Verbania Pallanza
Get PDFNo abstract availableInverno 2013-14: uno dei ?i? piovosi negli ultimi 90 anni Diario Antartico: impressioni di viaggio dalla XXIX Spedizione italiana in Antartid
An innovative, low-cost, small-scale rearing method for green lacewings (Neuroptera Chrysopidae)
Get PDFIn this paper we describe an innovative, low-cost, small-scale green lacewing (Neuroptera Chrysopidae) rearing method developed in our laboratories over a decade. Our method proves to be adaptable from a small laboratory to a local farmer\u27s insectary and its innovative aspects could be adopted in (and/or adapted to) mass rearing systems
Sensitivity of hypogean and epigean freshwater copepods (Crustacea Copepoda) to agricultural pollutants: single toxicants and mixtures
Get PDFWidespread pollution from agriculture is one of the major causes of poor freshwater quality currently observed across Europeand worldwide. Nutrient loads (nitrogen and phosphorous) from fertilizers and pesticides are known to adversely impact freshwater ecosystems, both surface- and ground water. The Crustacea Copepoda are by far the most abundant and species-rich taxon in ground water and they are consistently represented in ecotonal environments also, as in the hyporheic zone. The direct impact of agricultural pollutants on freshwater biota has been addressed in several studies by means of laboratory bioassays. However, the ecotoxicological research concerning freshwater copepods is scarce for epigean species and almost non-existent for the hypogean ones. Moreover, when available, ecotoxicological studies have been performed considering the effect of toxicants taken individually. Actually, this approach does not reflect the conditions in the field high concentrations of both N-fertilizers and pesticides co-occur. In this study we assessed the acute (at 96h) sensitivity of adults of a hypogean and an epigean species, both belonging to the Crustacea, Copepoda, Cyclopoida, Cyclopidae, to two agricultural toxicants: the ammonium nitrate and the herbicides Imazamox. Both chemicals are widely used for cereal agriculture inEurope. We tested the sensitivity considering the LC50 with mortality endpoints for individual and combined (a mixture solution of ammonium nitrate and Imazamox) toxicant concentrations. The hypogean species was more sensitive than the epigean one to both chemicals and their mixture. Ionized ammonia proved to be more toxic than the herbicide Imazamox for both species. However, the LC50 of both chemicals were lower than the actual standard law limits for good freshwater quality status defined by the Water Framework Directive (2000/60/CE). The effect of the mixture, of the two toxicants was fairly synergic. Concerning ionized ammonia, the LC50-96h in the mixture was higher than the law limits for both species. According to these results, the actual law limits for the good quality of freshwater bodies should be revised accordingly by authorities in charge of water management
Modern analyses on an historical data set: skull morphology of Italian red squirrel populations
Get PDFRecent molecular evidence suggests that Sciurus vulgaris populations from Calabria (southern Italy) are distinct from those occurring in northern and central Italy. Here, we re-analyzed using multivariate and univariate techniques an historical dataset provided by Cavazza (1913), who documented measurements for the now extinct squirrel population from Campania. Both univariate and multivariate analyses confirmed that the sample from Calabria was homogenous and relatively distinct compared to the rest of the squirrel samples
On the tracks of Nitrogen deposition effects on temperate forests at their southern European range - an observational study from Italy
No full textWe studied forest monitoring data collected at permanent plots in Italy over the period 2000-2009 to identify the possible impact of nitrogen (N) deposition on soil chemistry, tree nutrition and growth. Average N throughfall (N-NO3+N-NH4) ranged between 4 and 29 kg ha-1 yr-1, with Critical Loads (CLs) for nutrient N exceeded at several sites. Evidence is consistent in pointing out effects of N deposition on soil and tree nutrition: topsoil exchangeable base cations (BCE) and pH decreased with increasing N deposition, and foliar nutrient N ratios (especially N : P and N : K) increased. Comparison between bulk openfield and throughfall data suggested possible canopy uptake of N, levelling out for bulk deposition >4-6 kg ha-1 yr-1. Partial Least Square (PLS) regression revealed that - although stand and meteorological variables explained the largest portion of variance in relative basal area increment (BAIrel 2000-2009) - N-related predictors (topsoil BCE, C : N, pH; foliar N-ratios; N deposition) nearly always improved the BAIrel model in terms of variance explained (from 78.2 to 93.5%) and error (from 2.98 to 1.50%). N deposition was the strongest predictor even when stand, management and atmosphere-related variables (meteorology and tropospheric ozone) were accounted for. The maximal annual response of BAIrel was estimated at 0.074-0.085% for every additional kgN. This corresponds to an annual maximal relative increase of 0.13-0.14% of carbon sequestered in the above-ground woody biomass for every additional kgN, i.e. a median value of 159 kgC per kgN ha-1 yr-1 (range: 50-504 kgC per kgN, depending on the site). Positive growth response occurred also at sites where signals of possible, perhaps recent N saturation were detected. This may suggest a time lag for detrimental N effects, but also that, under continuous high N input, the reported positive growth response may be not sustainable in the long-term
Bioremediation in marine ecosystems: a computational study combining ecological modeling and flux balance analysis
Get PDFThe pressure to search effective bioremediation methodologies for contaminated ecosystems has led to the large-scale identification of microbial species and metabolic degradation pathways. However, minor attention has been paid to the study of bioremediation in marine food webs and to the definition of integrated strategies for reducing bioaccumulation in species. We propose a novel computational framework for analysing the multiscale effects of bioremediation at the ecosystem level, based on coupling food web bioaccumulation models and metabolic models of degrading bacteria. The combination of techniques from synthetic biology and ecological network analysis allows the specification of arbitrary scenarios of contaminant removal and the evaluation of strategies based on natural or synthetic microbial strains. In this study, we derive a bioaccumulation model of polychlorinated biphenyls (PCBs) in the Adriatic food web, and we extend a metabolic reconstruction of Pseudomonas putida KT2440 (iJN746) with the aerobic pathway of PCBs degradation. We assess the effectiveness of different bioremediation scenarios in reducing PCBs concentration in species and we study indices of species centrality to measure their importance in the contaminant diffusion via feeding links. The analysis of the Adriatic sea case study suggests that our framework could represent a practical tool in the design of effective remediation strategies, providing at the same time insights into the ecological role of microbial communities within food webs
Towards an ontological analysis of BPMN
Get PDFBPMN is a de-facto standard with more than 70 commercial tools that currently support its use. However, its the semantic ambiguities jeopardize its implementation. We perform an ontological analysis of important constructs of bpmn like activities and events to highlight their implicit commitments