2,532 research outputs found

    Reverse electrodialysis – Multi effect distillation heat engine fed by lithium chloride solutions

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    Salinity Gradient Heat Engines (SG-HEs) have been proposed as a promising technology for converting low-temperature heat into electricity. The SG-HE includes two different processes: (i) a salinity gradient process where the salinity gradient between two solutions is converted into electricity and (ii) a thermal regeneration process where low-grade heat (T<100°C) is used to re-establish the original salinity gradient of the two streams. Among the proposed working solutions, aqueous solution of lithium chloride has been identified as one of the most promising thanks to its remarkable solubility and activity. In this work, a process model to study the performance of a SG-HE constituted by a Reverse ElectroDialysis (RED) unit coupled with a Multi Effect Distillation (MED) unit fed with lithium chloride solution is presented. The influence of the concentration of the inlet solution in the RED unit and the temperature difference in the evaporators of the MED unit on the performance were evaluated by considering ideal membranes. Furthermore, the impact of membrane permselectivity and resistance on the system performance was evaluated. Results showed promising system efficiencies, making this technology attractive for conversion of low-grade heat (<100°C) into electricity, but membrane properties should be enhanced

    Mitochondrial heteroplasmy in an avian hybrid form (Passer italiae: Aves, Passeriformes)

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    Mitochondrial heteroplasmy is the result from biparental transmission of mitochondrial DNA (mtDNA) to the offspring. In such rare cases, maternal and paternal mtDNA is present in the same individual. Though recent studies suggested that mtDNA heteroplasmy might be more common than previously anticipated, that phenomenon is still poorly documented and was mostly detected in case studies on hybrid populations. The Italian sparrow, Passer italiae is a homoploid hybrid form that occurs all across the Italian Peninsula mostly under strict absence of either of its parent species, the house sparrow (P. domesticus) and the Spanish sparrow (P. hispaniolensis). In this study, we document a new case of mitochondrial heteroplasmy from two island populations of P. italiae (Ustica and Lipari). Our analysis was based on the mitochondrial NADH dehydrogenase subunit 2 (ND2) that allows for a clear distinction between mitochondrial lineages of the two parental species. We amplified and sequenced the mitochondrial ND2 gene with specifically designed primer combinations for each of the two parental species. In two of our study populations, a single individual carried two different ND2 haplotypes from each of the two parental lineages. These findings contribute to current knowledge on the still poorly documented phenomenon of paternal leakage in vertebrates

    Active packaging to improve the shelf-life and nutritional quality of strawberries

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    Kiwifruit under plastic covering: impact on fruit quality and on orchard microclimate

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    Italy has a preeminent rank in kiwifruit industry, being the first exporter and the second largest producer after China. However, in the last few years kiwifruit yields and the total cultivated area considerably decreased, due to the disease spread of the bacterial canker caused by Pseudomonas syringae pv. actinidiae (Psa). Bacterial canker has affected significantly orchards productivity and consequently has caused severe economic losses in all major areas of kiwifruit cultivation, including Italy,and considerable damage to the international kiwifruit industry.Several climatic conditions and cultural practices affect the development of the bacterial canker.Orchard hygiene, restrictions on the movement of nursery plants, orchard management and cultural practices, chemical and biological controls and breeding programs are being employed to limit the diffusion of the disease and help kiwifruit orchards to survive and produce. A possible way seems to be the modification of environmental conditions and it is being explored through the building of plastic covers over the orchards. This research work is focused on the impact of plastic cover on fruit quality, microclimate conditions and incidence of Psa. To evaluate the impact of plastic cover on microclimate, quality of fruits and disease incidence the following parameters were evaluated: climatic parameters (temperature, PAR), quality parameters (color, fruit firmness, titratable acidity, °Brix, vitamin C), disease incidence (%).  The use of a permanenttunnel modify light intensity and microclimate without any negative consequences on kiwifruits quality. Covering a kiwifruit orchard with a protective canopy reduces the spread of Psa throughout the orchard when covers are constructed over vines with low levels of infection.The use of plastic covers ensure the production of the current and future kiwifruit without compromising the quality of the fruit, but future trials will provide further information clarifying the effectiveness of the actual crop covers
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