58 research outputs found

    Malacofaune spiaggiate della costa occidentale della Sardegna. Fisiografia e batimetria dei fondali marini di provenienza

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    Herein are presented the results of research of an autoecological nature concerning beached malacological fauna gathered along the west coast of Sardinia. The resulting data contribute to defining the composition and structure of thanatocoenosis gathered at 35 biosites and allow estimation of the «bathymetric maximum» (30-40 metres) equivalent to the greatest depth at which sediments and the remains of molluscs within them are mobilized. Homogeneous «timed» sampling led to useful statistical comparisons between the different malacological associations gathered and made it possible to recognize the stocks of benthic populations most involved in the transportation of material: AP, SFBC, HP. By means of the autoecological analysis of recognized species, especially using data on texture, way of life and biocoenotic significance, the paper discusses the physiography of the sea bottoms mobilized in front of the biosites sampled. A database on the systematic taxonomy and autoecology of the 223 species identified, which represents a point of reference also in palaeoecological research into Neogenic and Quaternary fossiliferous deposits of Sardinia, is presented

    Autoecologia e ambiente dei molluschi marini alloctoni raccolti in spiagge delle coste meridionale e sud-orientale della Sardegna

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    The present work is devoted to thanatocoenosis of beached molluscs along the south and southeaster coasts of Sardinia. In sampling the 32 biosites a homogeneous «timed» method was adopted to allow a significant statistical comparison between the different associations. Overall, 188 species of molluscs were identified. Among these were found 74 bivalves, 111 gastropods, 2 scafopods and 1 polyplacophores. These species, together with their essential synonyms, were systematically classified. The autoecological analysis of the species supplied useful information on: texture, way of life, trophic level, biocoenotic significance and bathymetric category. In particular, the structure of the associations of organisms gathered was defined and the entity of the different biocoenotic stocks represented in them was estimated. By means of the statistical analysis the possible site of the ‘bathymetric maximum’ (some 30 metres) connected with the mobilization of sediments and the remains of the molluscs contained in them was deduced, as was the biocoenosis most involved: AP, SFBC, HP). Information on the way of life, the biocoenotic significance and texture of every single species led to the drawing up of a good approximation of the physiography of the sea bottoms in front of the beaches that were sampled

    An intracooling system for a novel two-stage sliding-vane air compressor

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    Lube-oil injection is used in positive-displacement compressors and, among them, in sliding-vane machines to guarantee the correct lubrication of the moving parts and as sealing to prevent air leakage. Furthermore, lube-oil injection allows to exploit lubricant also as thermal ballast with a great thermal capacity to minimize the temperature increase during the compression. This study presents the design of a two-stage sliding-vane rotary compressor in which the air cooling is operated by high-pressure cold oil injection into a connection duct between the two stages. The heat exchange between the atomized oil jet and the air results in a decrease of the air temperature before the second stage, improving the overall system efficiency. This cooling system is named here intracooling, as opposed to intercooling. The oil injection is realized via pressure-swirl nozzles, both within the compressors and inside the intracooling duct. The design of the two-stage sliding-vane compressor is accomplished by way of a lumped parameter model. The model predicts an input power reduction as large as 10% for intercooled and intracooled two-stage compressors, the latter being slightly better, with respect to a conventional single-stage compressor for compressed air applications. An experimental campaign is conducted on a first prototype that comprises the low-pressure compressor and the intracooling duct, indicating that a significant temperature reduction is achieved in the duct

    Experimental investigation into an ORC-based low-grade energy recovery system equipped with sliding-vane expander using hot oil from an air compressor as thermal source

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    Compressed air production is an energy-intensive sector, thus compressor manufacturers are constantly looking for enhancing the efficiency, by acting on several technological aspects. In an air compressor, about 80-90% of the input electric power used is wasted into the environment through the oil circuit, continuously cooled by ambient air blown via a fan. An interesting way to optimize the overall system efficiency is to exploit this waste heat to produce electrical power. Organic Rankine Cycles (ORCs) are a suitable solution for recovering energy from low-grade heat source. In this paper, an experimental analysis of two low-grade ORC-based recovery systems is presented. The thermal source is the hot lubricant of a mid-size air compressor, while the thermal sink is tap water. The first system is tested in a simple cycle configuration while the second in a recuperative one. An extensive experimental campaign is carried out on a test bench composed by sliding-vane expander, pump and plate heat exchangers. The expander differs in terms of geometry and aspect ratio between the two cycles. R236fa is used as working fluid in both the systems. The expander operating conditions are deeply investigated by using piezoelectric pressure transducers to determine the expansion indicated diagram and the expander mechanical efficiency. Experimental results show that the recuperative cycle has a better performance, in terms of cycle efficiency and expander mechanical efficiency, compared with the simple cycle. For this configuration, two off-design conditions are investigated, acting on the pump rotational speed. Finally, an exergy analysis is conducted, in order to evaluate the irreversible losses produced by each component

    Radio multifrequency observations of Abell 781 with the WSRT

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    The Main galaxy cluster in the Abell 781 system is undergoing a significant merger and accretion process with peripheral emission to the north and south-eastern flanks of the merging structure. Here we present a full polarimetric study of this field, using radio interferometric data taken at 21 and 92 cm with the Westerbork Synthesis Radio Telescope (WSRT), to a sensitivity better than any 21 cm (L band) observation to date. We detect evidence of extended low-level emission of 1.9 mJy associated with the Main cluster at 21 cm, although this detection necessitates further follow-up by modern instruments due to the limited resolution of the WSRT. Our polarimetric study indicates that, most likely, the peripheral emission associated with this cluster is not a radio relic

    Automated extraction of standardized antibiotic resistance and prescription data from laboratory information systems and electronic health records: a narrative review

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    Antimicrobial resistance in bacteria has been associated with significant morbidity and mortality in hospitalized patients. In the era of big data and of the consequent frequent need for large study populations, manual collection of data for research studies on antimicrobial resistance and antibiotic use has become extremely time-consuming and sometimes impossible to be accomplished by overwhelmed healthcare personnel. In this review, we discuss relevant concepts pertaining to the automated extraction of antibiotic resistance and antibiotic prescription data from laboratory information systems and electronic health records to be used in clinical studies, starting from the currently available literature on the topic. Leveraging automatic extraction and standardization of antimicrobial resistance and antibiotic prescription data is an tremendous opportunity to improve the care of future patients with severe infections caused by multidrug-resistant organisms, and should not be missed

    Prev Chronic Dis

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    IntroductionObesity is highly prevalent among American Indians, and effective prevention efforts require caregiver involvement. We examined American Indian (AI) parents' assessment of and level of concern about their kindergarten child's weight status.MethodsWe collected baseline data (fall of 2005 and fall of 2006) on children and their parents or caregivers for a school-based obesity prevention trial (Bright Start) on an AI reservation in South Dakota. The current study uses 413 parent-child pairs. Age- and sex-adjusted body mass index percentiles were categorized as very underweight (<5th percentile), slightly underweight (5th to <15th percentile), normal weight (15th to <85th percentile), overweight (85th to <95th percentile), and obese ( 6595th percentile). Parents or caregivers reported their assessment of and concerns about their child's weight status as well as sociodemographic characteristics. We used mixed-model multivariable analysis to examine associations between sociodemographic characteristics and the probability of parents underclassifying or overclassifying their child's weight status; analyses were adjusted for school as a random effect.ResultsChildren were evenly divided by sex and had a mean age of 5.8 years. Twenty-nine percent of children and 86% of parents were overweight or obese. Approximately 33% (n = 138) of parents underclassified and 7% (n = 29) of parents overclassified their child's weight status. Higher parental weight status and higher concern about their child's weight status increased the probability of underclassification (P for trend = .02 for both).ConclusionIn this sample of at-risk children, one-third of parents underclassified their child's weight status. Childhood obesity prevention programs need to increase awareness and recognition of childhood obesity and address parental weight issues.2012649
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