Analisi teorica, progettazione e sperimentazione di sistemi per la produzione di idrogeno da idrocarburi

Nel presente lavoro sono state approfondite le tematiche relative alla riformulazione degli idrocarburi in sistemi compatti, applicabili a bordo di autoveicoli, in particolar modo quelle inerenti la progettazione. Sono stati sviluppati numerosi modelli di calcolo al fine di approntare uno strumento di fluidodinamica computazionale in grado di simulare i fenomeni che caratterizzano le diverse fasi del processo, e guidare la progettazione di detti sistemi. I modelli predisposti, prima di essere impiegati per la progettazione, sono stati ampiamente validati sulla base dei risultati sperimentali a disposizione: per quanto al reforming del gasolio si è fatto riferimento ad un reattore sviluppato nell’ambito di un progetto finanziato dall’Unione Europea denominato “Direct”, cui hanno partecipato enti di ricerca pubblici e privati ed aziende, per quanto al reforming del metano si è fatto riferimento alla letteratura scientifica. I modelli sono stati poi impiegati con successo nella progettazione di due reattori, il primo denominato “Prometer” è in grado di operare la riformulazione di combustibili liquidi, l’altro denominato “Syngas UTV” di quelli gassosi. I due sistemi sono stati concepiti in maniera da essere in grado di gestire combustibili diversi (sistemi multifuel), la sperimentazione in laboratorio si è però focalizzata sull’utilizzo di gasolio e metano. In particolare la scelta di sperimentare il reattore “Prometer” sul gasolio è dovuta al fatto che questi presenta caratteristiche che ne rendono particolarmente difficile la riformulazione senza incappare nella formazione di particolato, cui segue l’interruzione irreversibile del funzionamento del reattore. Per questo motivo lo sviluppo di sistemi stabili ed in grado di garantire durate di funzionamento adeguate, per l’ossidazione parziale del gasolio finalizzata alla produzione di idrogeno, rappresenta ancora un obiettivo per il mondo scientifico. I risultati della sperimentazione sono stati estremamente soddisfacenti, anche per la riformulazione del gasolio, sebbene in un unico ciclo di dottorato non sia stato possibile approfondire ulteriormente la sperimentazione, per l’ingente impegno di tempo che lo sviluppo dei sistemi ha richiesto. La prosecuzione delle attività di ricerca intraprese ha eccellenti possibilità di concludere favorevolmente verso la possibilità di giungere allo sviluppo di sistemi stabili ed in grado di operare senza produzione di particolato, che non è stata riscontrata nelle prime prove effettuate sul reattore. Per scongiurare tale evenienza si ritiene, sia sulla base delle evidenze sperimentali che dalle simulazioni effettuate, che le fasi di vaporizzazione e miscelazione abbiano un ruolo fondamentale.Scope of this work is to examine design issues concerning the reforming of the hydrocarbons in compact systems, which can be used for hydrogen generation onboard vehicles. Several models have been developed in order to build a comprehensive fluid dynamics tool to simulate physical and chemical phenomena that affect reforming process. Models have been extensively validated on results from scientific literature and "Direct" project, a research program funded by the European Union which concern Diesel fuel reforming. The models were then used successfully in the design of two reactors, the first called "Prometer", the other "Syngas UTV", which are capable of operating Catalytic Partial Oxidation (CPOx) of liquid fuels and gaseous fuels respectively. The two multifuel systems have been tested with Diesel fuel and methane. In particular, the choice of run "Prometer" reactor with Diesel fuel is due to the fact that gasoil CPOx is particularly difficult due to soot formation, which often involves fast and irreversible shutdown of the reactor. For this reason, the development of stable and long-life CPOx reactors for Diesel fuel is still an objective for scientific community. The experimental result were successful, even for Diesel reforming, since no soot formation was observed during experiments. To this goal, fuel vaporization and mixing were found to have a key role

An iterative guidance and navigation algorithm for orbit rendezvous of cooperating cubeSats

Modern space missions often require satellites to perform guidance, navigation, and control tasks autonomously. Despite their limited resources, small satellites are also involved in this trend, as in-orbit rendezvous and docking maneuvers and formation flying have become common requirements in their operational scenarios. A critical aspect of these tasks is that these algorithms are very much intertwined with each other, although they are often designed completely independently of one another. This paper describes the design and simulation of a guidance and relative navigation architecture for the rendezvous of two cooperating CubeSats. The integration of the two algorithms provides robustness to the solution, by simulating realistic levels of noise and uncertainty in the guidance law implementation. The proposed guidance law is derived based on the linearized equations of orbital motion, written in terms of spherical coordinates. The trajectory is iteratively corrected at a fixed time step, so that errors from the navigation and the initial orbital condition can be recovered. The navigation algorithm processes the bearing and range measurements from a camera and an intersatellite link through an unscented filter to provide the information required from the guidance law. A Monte Carlo campaign based on a 3-DOF simulation demonstrates the effectiveness of the proposed solution.</jats:p

Neurobehavioral Alterations from Noise Exposure in Animals: A Systematic Review

Ecosystems are increasingly involved and influenced by human activities, which are ever-increasing. These activities are mainly due to vehicular, air and sea transportation, thus causing possible repercussions on the fauna that exists there. The aim of this systematic review is to investigate the possible consequences that these activities may have in the field of animal neurobehavior, with special emphasis on the species involved, the most common environment concerned, the noise source and the disturbance that is caused. This research includes articles published in the major databases (PubMed, Cochrane Library, Scopus, Embase, Web of Sciences); the online search yielded 1901 references. After selection, 49 articles (14 reviews and 35 original articles) were finally scrutinized. The main problems that were reported were in relation to movement, reproduction, offspring care and foraging. In live experiments carried out, the repercussions on the marine environment mainly concerned altered swimming, shallower descents, less foraging and an escape reaction for fear of cetaceans and fish. In birds, alterations in foraging, vocalizations and nests were noted; laboratory studies, on the other hand, carried out on small mammals, highlighted spatio-temporal cognitive alterations and memory loss. In conclusion, it appears that greater attention to all ecosystems should be given as soon as possible so as to try to achieve a balance between human activity and the well-being of terrestrial fauna

Grazing affects metabolic pattern of individual cow milk

Effective traceability tools able to characterize milk from pasture are important to safeguard low-input farming systems, niche dairy products, and local traditions. The aims of the present study were to investigate the ability of proton nuclear magnetic resonance (1H NMR) spectroscopy to discriminate between milk produced from cows before and after the beginning of the grazing season, and to assess the effects of grazing on milk metabolites. The research trial involved a single alpine holding with 72 lactating cows. Individual milks were repeatedly sampled from the same animals before (i.e., d −3 and −1) and after (i.e., d 2, 3, 7, 10, and 14) the onset of the grazing period. One-dimensional 1H NMR spectra of milk extracts were collected through a Bruker spectrometer. Random forest discriminant analysis was applied to 1H NMR spectra to predict the period of collection for each sample. Data concerning the relative abundance of milk metabolites were analyzed through a linear mixed model, which included the fixed effects of period of sampling, cow breed, stage of lactation, and parity, and the random effect of cow nested within breed. The random forest model exhibited great accuracy (93.1%) in discriminating between samples collected on d −3, −1, 2, and 3 and those collected on d 7, 10, and 14. Univariate analysis performed on the 40 detected metabolites highlighted that milk samples from pasture had lower levels of 14 compounds (with fumarate being the most depressed metabolite) and greater levels of 15 compounds (with methanol and hippurate being the most elevated metabolites). Results indicate that milk 1H NMR spectra are promising to identify milk produced in different conditions. Also, our study highlights that grazing is associated with significant changes of milk metabolic profile, suggesting the potential use of several metabolites as indicators of farm management

Alcohol consumption and employment: a cross-sectional study of office workers and unemployed people

alcohol is a psychoactive substance with toxic and addictive properties. biomarkers like GGT, AST, ALT and MCV are influenced by excessive ethanol consumption. alcohol consumption represents a health risk and it has been linked to unemployment. the aim of this study how working status predict alcohol consumption through a cross sectional study comparing alcohol-related biomarkers levels in office workers and unemployed people. methods this study includes 157 office workers and 157 unemployed people, who were recruited from January to december 2018. a propensity score matching procedure was applied to obtain two homogenous groups in terms of age and gender. A non-parametric analysis was performed on serum biomarkers that are generally altered by alcohol consumption. logistic regression models were designed to evaluate how working status predict abnormal biomarker levels related with alcohol consumption. results no differences in median biomarker values were found between groups. Logistic regression analysis showed that office work is a negative predictor of pathological biomarker levels. office workers had a significant relation with the levels of GGT (OR 0.48; 95% CI [0.28–0.84]), AST (OR 0.42; 95% CI [0.22–0.78]), ALT (OR 0.39; 95% CI [0.23–0.66]), and MCV (OR 0.37; 95% CI [0.19–0.70]). conclusion office workers had lower absolute frequencies of pathological values of alcohol consumption biomarkers, after matching for age and gender compared with unemployed people. In addition, a significant negative association between office work is a negative predictor of biomarker levels of alcohol consumption. these results showed that work is an important determinant of health and that can represent a benefit for workers in terms of reducing the risk of consuming alcohol

Pleurotus ostreatus spent mushroom substrate for the degradation of polycyclic aromatic hydrocarbons: the case study of a pilot dynamic biopile for the decontamination of a historically contaminated soil

BACKGROUND: Polycyclic aromatic hydrocarbons (PAHs) are hazardous contaminants. Bio-based technology is among recommended practices for the recovery of PAH contaminatedmatrices. The objective of the study was to validate the exploitation of spent mushroom substrate (SMS), an organic waste deriving from the industrial production of Pleurotus ostreatus, as bulking agent in a dynamic biopile pilot plant, because of the SMS potential oxidative capacity towards aromatic recalcitrant compounds. The dynamic biopile pilot plant treated 7 tons of a historically PAH contaminated soil (6469±423mg PAHs kg−1), classified as dangerous waste. RESULTS: Themixing of SMSwith soilwasmandatory for the depletion of PAHs, which after 8months,were at significantly lower concentrations (112±5mg PAHs kg−1). The treated soil was capable of reintroduction to the industrial site of origin. However, a residual genotoxicity of soil elutriates at the end of the process wasmeasured on root tips of Vicia faba L. CONLUSIONS: The SMS derived from the industrial production of P. ostreatus is exploitable as a versatile low cost organic substrate with oxidative capacity towards PAHs and its exploitation as a bulking agent in biopiles is advantageous for the disposal of the organic waste

Low-dose benzene exposure monitoring of oil refinery workers: inhalation and biomarkers

Airborne benzene in workplaces has progressively decreased due to preventive actions and the redesigning of facility processes. Professionals who assess occupational exposure should select techniques to detect benzene levels comparable to ambient air exposure. Thus, sensitive biomarkers are needed to discriminate the effects of confounding factors, such as smoking or sorbic acid (SA). In order to identify sensitive biomarkers and to study their correlation with confounding factors, 23 oil refinery workers were enrolled in the study; their airborne benzene exposures and biomarkers were monitored. Urinary benzene (U-B), t,t-muconic acid (t,t-MA), and S-phenylmercapturic acid (SPMA) were quantified. Urinary cotinine (U-C) and t,t-sorbic acid (t,t-SA) were evaluated to flag smoking and SA intake, respectively. The benzene measured in personal inhalation sampling ranged from 0.6 to 83.5 (median 1.7) µg/m3. The concentration range of the biomarkers, U-B, t,t-MA, and SPMA, were 18–4893 ng/m3, &lt;10–79.4 µg/g creatinine, and &lt;0.5–3.96 µg/g creatinine, respectively. Pearson tests were carried out; the best correlations were between airborne benzene and U-B (µg/L r = 0.820, p &lt; 0.001) and between benzene and SPMA (g/L r = 0.812, p &lt; 0.001), followed by benzene and t,t-MA (mg/L r = 0.465, p = 0.039). From our study, U-B and SPMA result to be the most reliable biomarkers to assess the internal number of low doses of benzene exposure, thanks to their specificity and sensitivity

RECOVERING OF DREDGED SEDIMENTS CONTAMINATED BY TOTAL PETROLEUM HYDROCARBON TO PRODUCTIVE SOILS: THE MYCOREMEDIATION APPROACH IN THE BIORESNOVA PROJECT

Chemo-physical treatments to remove salinity and metal contamination from dredged sediments were applied in combination to bio-based approaches (mycoremediation). New fungal specimen were isolated from the contaminated sediments, massively grown and re-inoculated in the matrix in treatment to remove the Total Petroleum Hydrocarbon contamination (TPH). Toxicological assays were exploited to estimate the sediment remediation efficiency over time. Indeed, the only chemical characterization of polluted matrices does not allow to predict the residual toxicity of the latter eventually related to the permanence of a residual contamination by the parental pollutants, to their degradation intermediates and/or to the synergic actions of the both. Higher plants (Vicia faba L.) were exploited as indicators of the quality of the treated sediments and used both for the continuous monitoring of the remediation processes and for the evaluation of the final product eco-safety. Biological parameters such as the genotoxicity by means of cytological analysis of mitotic behavior of root meristems were evaluated based on the detection of chromosomal aberrations in mitotic cells, and of micronuclei formation, detectable in interphase cells. The combination of the Chemo-physical and the Bio-based approach was able to remove the organic contamination (TPH) and the excess of sodium salts that constitute a critical point for the eventual re-allocation of dredged sediments. At the same time the sediments were detoxified and actually gained the biochemical traits of humified productive soils, eventually suitable for their safe re-allocation in the environment

AC/DC: The FERMI FEL Split and Delay Optical Device for Ultrafast X-ray Science

Free-electron lasers (FELs) are the most advanced class of light-sources, by virtue of their unique capability to lase high-brightness pulses characterized by wavelengths spanning the extreme-ultraviolet, the soft and hard X-ray spectral domains, as well as by temporal lengths lying in the femtosecond (fs) timescale. The next step to push the current standards in ultrafast X-ray science is strongly linked to the possibility of engineering and exploiting time-resolved experiments exclusively for FELs pulses, ideally having different colors tunable at specific electronic resonance of the chemical elements. At the seeded FERMI FEL (Trieste, Italy) this goal is committed to the optical device known as AC/DC, which stands for the auto correlator/delay creator. AC/DC is designed to double the incoming FEL pulse splitting the photon beam by inserting a grazing incidence flat mirror, thus preserving the spectral and temporal properties, and further delaying one of these two pulses in time. It can independently tune the FEL pulses fluence on the two optical paths by means of solid-state filters, too. Here, we present a detailed description about this optical device. Strong emphasis is dedicated to the AC/DC opto-mechanical design and to the laser-based feedback systems implemented to compensate for any mismatch affecting the FEL optical trajectory, ascribable to both mechanical imperfections and paraxial errors rising during a temporal delay scan

Preventing transmission of infectious agents in the pediatric in-patients hematology-oncology setting: what is the role for non-pharmacological prophylaxis?

The most intensive chemotherapy regimens were used in the past for leukemia patients who were the main focus of trials on infections; today there are increasing numbers of children with solid cancer and considerable risk of infection who do receive intensive standard-dose chemotherapy. Despite a continuous will to protect the immune-compromised child from infections, evidence-based indications for intervention by non-pharmacological tools is still lacking in the pediatric hematology-oncology literature. Guidelines on standard precautions as well as precautions to avoid transmission of specific infectious agents are available. As a result of a consensus discussion, the Italian Association for Pediatric Hematology-Oncology (AIEOP) Cooperative Group centers agree that for children treated with chemotherapy both of these approaches should be implemented and vigorously enforced, while additional policies, including strict environmental isolation, should be restricted to patients with selected clinical conditions or complications. We present here a study by the working group on infectious diseases of AIEOP