High performance waterjets: study of an innovative scoop inlet and development of a novel method to design ducted propellers.

In the last decades the diffusion of waterjet systems for commercial applications in the high speed field is on the increase. These marine propulsors show remarkable qualities in terms of fuel consumption, noise, vibrations and manoeuvrability but they have some disadvantages which make their use optimal only for a limited speed range and which limit the overall propulsive efficiency. In the present document is described a way to modify a conventional waterjet with the aim of reducing these problems, increasing the overall efficiency. Many problems are dealt with. In chapter 3 it is shown how the substitution of a conventional flush inlet with a new scoop inlet could be an efficient way to minimise the total pressure losses and the non-uniformity velocity distribution upstream the pump, limiting in this way the influence of the boundary layer ingestion on the machine performance. In chapter 4 a novel method to study and design axial pumps is developed and explained. In chapter 5 a rim driven propeller is designed and tested numerically and experimentally demonstrating the good prediction capabilities of the method

Effect of an electronic nicotine delivery device (e-Cigarette) on smoking reduction and cessation: a prospective 6-month pilot study

BACKGROUND: Cigarette smoking is a tough addiction to break. Therefore, improved approaches to smoking cessation are necessary. The electronic-cigarette (e-Cigarette), a battery-powered electronic nicotine delivery device (ENDD) resembling a cigarette, may help smokers to remain abstinent during their quit attempt or to reduce cigarette consumption. Efficacy and safety of these devices in long-term smoking cessation and/or smoking reduction studies have never been investigated. METHODS: In this prospective proof-of-concept study we monitored possible modifications in smoking habits of 40 regular smokers (unwilling to quit) experimenting the 'Categoria' e-Cigarette with a focus on smoking reduction and smoking abstinence. Study participants were invited to attend a total of five study visits: at baseline, week-4, week-8, week-12 and week-24. Product use, number of cigarettes smoked, and exhaled carbon monoxide (eCO) levels were measured at each visit. Smoking reduction and abstinence rates were calculated. Adverse events and product preferences were also reviewed. RESULTS: Sustained 50% reduction in the number of cig/day at week-24 was shown in 13/40(32.5%) participants; their median of 25 cigs/day decreasing to 6 cigs/day (p < 0.001). Sustained 80% reduction was shown in 5/40(12.5%) participants; their median of 30 cigs/day decreasing to 3 cigs/day (p = 0.043). Sustained smoking abstinence at week-24 was observed in 9/40(22.5%) participants, with 6/9 still using the e-Cigarette by the end of the study. Combined sustained 50% reduction and smoking abstinence was shown in 22/40 (55%) participants, with an overall 88% fall in cigs/day. Mouth (20.6%) and throat (32.4%) irritation, and dry cough (32.4%) were common, but diminished substantially by week-24. Overall, 2 to 3 cartridges/day were used throughout the study. Participants' perception and acceptance of the product was good. CONCLUSION: The use of e-Cigarette substantially decreased cigarette consumption without causing significant side effects in smokers not intending to quit (http://ClinicalTrials.gov number NCT01195597)

Hoverspill: a new amphibious vehicle for responding in difficult-to-access sites

Oil spill experience often shows that response activities are hampered due to the absence of operative autonomous support capable of reaching particular sites or operate in safe and efficient conditions in areas such as saltmarshes, mudflats, river banks, cliff bottoms… This is the purpose of the so-called FP7 Hoverspill project (www.hoverspill.eu), a 3-year European project that recently reached completion: to design and build a small-size amphibious vehicle designed to ensure rapid oil spill response. The result is an air-cushion vehicle (ACV), known as Hoverspill, based on the innovative MACP (Multipurpose Air Cushion Platform) developed by Hovertech and SOA. It is a completely amphibious vehicle capable of working on land and on water, usable as a pontoon in floating conditions. Its compactness makes it easy to transport by road. The project also included the design and building of a highly effective integrated O/W Turbylec separator developed by YLEC. Spill response equipment will be loaded on-board based on a modular concept enabling the vehicle to carry out specific tasks with just the required equipmen

Peptide-tags for enhanced DNA microarray performance

DNA microarrays are powerful tools for gene expression analysis and genotyping studies in research and diagnostic applications. A high sensitivity and short time-to-result are prerequisites for their practical application in the clinic. The hybridization efficiency of DNA microarrays depends on the probe density and the probe orientation and thus their accessibility for target molecules. In order to find an optimal probe immobilization procedure a set of different oligonucleotide modifications was tested on epoxy silane functionalized glass slides. It was found that histidine-tagged oligonucleotides resulted in the highest amount of bound probe and by far the best hybridization efficiencies. The detection limit obtained with histidine-tagged probes was up to two orders of magnitude lower compared to commonly used probe modifications. In order to further investigate the binding mechanism of histidine-tags towards functionalized glass substrates a set of different peptide-tags with and without free terminal amino-groups and with different amino acid compositions was tested. The results indicate an impact of the terminal amino group on the covalent surface binding and of aromatic amino acid residues on the enhanced hybridisation efficiency

High performance waterjets: study of an innovative scoop inlet and development of a novel method to design ducted propellers.

In the last decades the diffusion of waterjet systems for commercial applications in the high speed field is on the increase. These marine propulsors show remarkable qualities in terms of fuel consumption, noise, vibrations and manoeuvrability but they have some disadvantages which make their use optimal only for a limited speed range and which limit the overall propulsive efficiency. In the present document is described a way to modify a conventional waterjet with the aim of reducing these problems, increasing the overall efficiency. Many problems are dealt with. In chapter 3 it is shown how the substitution of a conventional flush inlet with a new scoop inlet could be an efficient way to minimise the total pressure losses and the non-uniformity velocity distribution upstream the pump, limiting in this way the influence of the boundary layer ingestion on the machine performance. In chapter 4 a novel method to study and design axial pumps is developed and explained. In chapter 5 a rim driven propeller is designed and tested numerically and experimentally demonstrating the good prediction capabilities of the method.Il documento riassume il progetto di dottorato sugli idrogetti ad alte prestazioni condotto dall'autore nel periodo che va dal 2012 al 2014. Durante il triennio sono stati affrontati due filoni principali di ricerca riguardo questi propulsori, focalizzandosi in particolare sullo studio dell'imbocco e del sistema pompante. Un idrogetto è una propulsore navale che riesce a produrre una forza propulsiva accelerando una massa d'acqua; durante questo processo la massa d'acqua, originariamente presente libera nell'ambiente marino o fluviale, attraversa quattro diversi componenti: l'imbocco, il sistema pompante, l'ugello e il sistema sterzante. Ogni componente possiede una sua funzionalità ma in generale massimizzando l'efficienza di questi componenti è possibile osservare un generico aumento delle prestazioni complessive. Il lavoro qui presentato si è focalizzato sullo studio dell'imbocco e del sistema pompante; volendo essere di carattere innovativo, le configurazioni e le idee qui presentate rappresentano delle alternative costruttive o metodologiche sostanzialmente differenti dalla comune prassi industriale. Lo studio dell'imbocco ha avuto come linea guida il confronto tra un imbocco commerciale di stampo tradizionale (i cosiddetti imbocchi flush) e un imbocco dinamico di derivazione aeronautica (imbocchi scoop). Lo studio, oltre a rappresentare forse l'unico caso in letteratura di studio specifico su imbocchi dinamici, mette in luce le criticità dell'imbocco tradizionale mostrando una via alternativa alla prassi industriale. Lo studio analizza le performance in termini di perdite di pressione totali e fattore di distorsione di questi due imbocchi, con e senza la presenza dell'albero di trasmissione, attraverso diverse analisi CFD. Interessante è la derivazione aeronautica dell'imbocco dinamico preso “in prestito” da studi NASA riguardanti un imbocco per un aereo sperimentale caratterizzato da importanti spessori dello strato limite. Lo studio dimostrerà, per il caso in analisi, la superiorità dell'imbocco dinamico rispetto a quello tradizionale nei termini di paragone sopra descritti, dimostrando la necessità di affrontare con critico approfondimento lo studio degli imbocchi sugli idrogetti in ambito industriale, rimettendo in discussione molti dogmi dati per scontati nella realtà industriale ma in verità mai dimostrati nella letteratura scientifica. Lo studio dell'apparato pompante è stato affrontato in due fasi, la prima squisitamente teorica , la seconda di carattere sperimentale. La fase teorica ha visto la definizione di un nuovo metodo per la progettazione di un apparato pompante assiale. Il metodo, che è stato successivamente implementato in un programma Matlab e validato, è un metodo di carattere generale frutto della combinazione di diversi metodi analitici già utilizzati in letteratura ma in maniera concettualmente differente; anche se sviluppato originariamente per una pompa di un idrogetto, è stato pensato per avere una validità generale e può essere utilizzato per lo studio di una qualsiasi pompa assiale intubata. Il metodo rappresenta una combinazione di un metodo BEM (Blade Element Momentum) con due teorie analitiche per il calcolo dei coefficienti di portanza e resistenza dei profili alari (Weinig e Lieblein) e dell'equazione di Eulero per le turbomacchine. Il metodo risultante è un metodo fortemente iterativo che permette di calcolare la geometria di una pompa assiale intubata e le sue prestazioni anche fuori dal punto di progetto senza la necessità di utilizzare fattori empirici di discutibile attendibilità; esso si dimostra quindi un metodo innovativo e flessibile per lo studio completo di un generico propulsore intubato. Il metodo è stato implementato e testato sia numericamente che sperimentalmente grazie alla collaborazione della “University of Southampton” e della ditta “TSL Technology” su un propulsore elettrico attuato in periferia. Il propulsore in questione fa parte di una classe di propulsori di nuova concezione meglio conosciuti come RDP (Rim Driven Propeller) che fra le varie caratteristiche hanno quella di abbandonare la necessità di un albero per la trasmissione della coppia motrice con la conseguente assenza delle perdite dovute alla presenza dell'albero immerso nel flusso dell'acqua. La realizzazione sperimentale di questo propulsore, oltre ad aver sensibilmente migliorato l'efficienza del propulsore rispetto a quelli sviluppati in passato dalla ditta coinvolta, ha dimostrato l'attendibilità del modello analitico sviluppato

Satellite Data Potentialities in Solid Waste Landfill Monitoring: Review and Case Studies

Remote sensing can represent an important instrument for monitoring landfills and their evolution over time. In general, remote sensing can offer a global and rapid view of the Earth’s surface. Thanks to a wide variety of heterogeneous sensors, it can provide high-level information, making it a useful technology for many applications. The main purpose of this paper is to provide a review of relevant methods based on remote sensing for landfill identification and monitoring. The methods found in the literature make use of measurements acquired from both multi-spectral and radar sensors and exploit vegetation indexes, land surface temperature, and backscatter information, either separately or in combination. Moreover, additional information can be provided by atmospheric sounders able to detect gas emissions (e.g., methane) and hyperspectral sensors. In order to provide a comprehensive overview of the full potential of Earth observation data for landfill monitoring, this article also provides applications of the main procedures presented to selected test sites. These applications highlight the potentialities of satellite-borne sensors for improving the detection and delimitation of landfills and enhancing the evaluation of waste disposal effects on environmental health. The results revealed that a single-sensor-based analysis can provide significant information on the landfill evolution. However, a data fusion approach that incorporates data acquired from heterogeneous sensors, including visible/near infrared, thermal infrared, and synthetic aperture radar (SAR), can result in a more effective instrument to fully support the monitoring of landfills and their effect on the surrounding area. In particular, the results show that a synergistic use of multispectral indexes, land surface temperature, and the backscatter coefficient retrieved from SAR sensors can improve the sensitivity to changes in the spatial geometry of the considered site

Antarctic Salt-Cones: An Oasis of Microbial Life? The Example of Boulder Clay Glacier (Northern Victoria Land)

The evaporation of a localized, highly saline water body of the Boulder Clay debris-covered glacier, in the Northern Victoria Land, probably generated the accumulation of mirabilite (Na2SO4 &times; 10H2O) and thenardite (Na2SO4) in a glacier salt-cone. Such an extremely cold and salty environment resembles the conditions on Mars, so it can be considered a terrestrial analog. The study was aimed at gaining a first glimpse at the prokaryotic community associated with Antarctic mirabilite and thenardite minerals and also to find clues about the origin of the salts. For this purpose, samples were analyzed by a next generation approach to investigate the prokaryotic (Bacteria and Archaea) diversity. Phylogenetic analysis allowed the identification of Bacteroidota, Actinobacteriota, Firmicutes, and Gammaproteobacteria as the main bacterial lineages, in addition to Archaea in the phylum Halobacterota. The genera Arthrobacter, Rhodoglobus, Gillisia, Marinobacter and Psychrobacter were particularly abundant. Interestingly, several bacterial and archaeal sequences were related to halotolerant and halophilic genera, previously reported in a variety of marine environments and saline habitats, also in Antarctica. The analyzed salt community also included members that are believed to play a major role in the sulfur cycle

Tetrahydrobiopterin and electron transfer in NO synthase

Mammalian NO synthase requires the cofactor tetrahydrobiopterin (H4B) to act as an electron donor during the activation of molecular oxygen at the heme site. After donating an electron, the resultant H4B radical is then required to abstract an electron from the ferrous NO complex, which is generated at the end of the catalytic reaction, in order to facilitate NO release. We have recently explored the structural requirements of NO synthase for the H4B cofactor by studying a range of novel cofactor analogues with highly modified structures. Substituents on the C6 and C7 positions of H4B are tolerated well, with surprisingly bulky pterins being able to bind and drive NO synthesis. The modified pterins have a wide range of activities and binding constants, but the main function of the cofactors in activating molecular oxygen appears to be independent of C6 and C7 modification as shown by rapid reaction studies. We have also assessed the possibility of direct electron transfer across the dimer interface between H4B molecules in the two NO synthase subunits. The H4B cofactors are within the range for facile electron transfer and present a possible mechanism for NO synthase to escape from the unreactive ferrous-NO complex, which is known to originate from product inhibition