109 research outputs found

    Solar-Powered Rankine Cycle Assisted by an Innovative Calcium Looping Process as an Energy Storage System

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    Solar energy is an intermittent resource, and thus an energy storage system is required for practical applications of the collected solar irradiance. This work deals with the integration of a thermo-chemical energy storage (TCES) system based on the calcium looping (CaL) process with a concentrated solar tower power (CSP) plant. The objective of this work is the integration of a conventional 320 MWe Rankine cycle with a direct calcination for energy harvesting. Particularly, this work addresses the use of CO2 as the working fluid of a compressed-gas energy storage (CGES) system for hybrid energy storage with the CaL process. The hybrid TC/CG-ES (thermo-chemical/compressed-gas energy storage) system can increase the competitiveness of the CSP with respect to conventional fossil-based power plants leading to a reduction in CO2 emissions. The thermal integration with the calcium looping (CaL) system is optimized by means of the pinch analysis methodology. The obtained results show a reduction in the electrical efficiency of about four percentage points with respect to the conventional Rankine power cycle without the CSP unit: the net electrical efficiency reduces from 43.7% to 39.5% while the global (thermal and electrical) efficiency of the plant reaches the peak value of 51.5% when low enthalpy energy is recovered (e.g., district heating network, district cooling network). This paper highlights the importance of the thermochemical CaO based material. With a conversion of CaO to CaCO3 of 80% the storage efficiency is defined as the ratio of the energy released during the carbonation and the CO2 expansion to the energy collected by the solar field and required during the CO2 compression, which is 87.3%

    Modeling and Simulation of an Oxygen-Blown Bubbling Fluidized Bed Gasifier using the Computational Particle-Fluid Dynamics (CPFD) Approach

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    Fluidized beds are conventional components of many industrial processes, such as coal gasification for energy generation and syngas production. Numerical simulations help to properly design and understand the complex multiphase flows occurring in these reactors. Two modeling approaches are usually adopted to simulate multiphase flows: the two fluids Eulerian-Eulerian model and the continuous/discrete Eulerian-Lagrangian model. Since fluidized beds account for an extremely large number of particles, tracking each of them could not assure to get results within a reasonable computational time. The Computational Particle-Fluid Dynamics (CPFD) approach, which belongs to the Eulerian-Lagrangian models class, groups together particles with similar key parameters (e.g. composition, size) into computational units (parcels). Parcel collisions are modeled by an isotropic solid stress function, depending on solid volume fraction. In this paper, the bubbling fluidized bed (BFB) upstream gasifier of the EU research infrastructure ZECOMIX (Zero Emissions of Carbon with Mixed technologies) has been simulated using a CPFD approach via BarracudaÂź software. The effect of different fluidizing agent injection strategies on bed bubbling and mixing, for non-reacting cases, has been studied. The numerical results for a reacting case have been compared to the available experimental data, gathered during the coal gasification campaign. The model has proved to be very useful in the choice of the more efficient injection configuration that assures a more effective contact of the gas with the solid bed and a good bubbling fluidization regime, together with a satisfactory prediction of the outlet gas composition. The numerical approach has turned out to be robust and time-saving and allowed to dramatically reduce the computational cost with respect the classical two fluids Eulerian-Eulerian models

    Antifibrotic treatment response and prognostic predictors in patients with idiopathic pulmonary fibrosis and exposed to occupational dust

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    BACKGROUND: Idiopathic Pulmonary Fibrosis (IPF) is an aggressive interstitial lung disease with an unpredictable course. Occupational dust exposure may contribute to IPF onset, but its impact on antifibrotic treatment and disease prognosis is still unknown. We evaluated clinical characteristics, respiratory function and prognostic predictors at diagnosis and at 12 month treatment of pirfenidone or nintedanib in IPF patients according to occupational dust exposure. METHODS: A total of 115 IPF patients were recruited. At diagnosis, we collected demographic, clinical characteristics, occupational history. Pulmonary function tests were performed and two prognostic indices [Gender, Age, Physiology (GAP) and Composite Physiologic Index (CPI)] calculated, both at diagnosis and after the 12 month treatment. The date of long-term oxygen therapy (LTOT) initiation was recorded during the entire follow-up (mean = 37.85, range 12-60 months). RESULTS: At baseline, patients exposed to occupational dust [≄ 10 years (n = 62)] showed a lower percentage of graduates (19.3% vs 54.7%; p = 0.04) and a higher percentage of asbestos exposure (46.8% vs 18.9%; p 0.002) than patients not exposed [< 10 years (n = 53)]. Both at diagnosis and after 12 months of antifibrotics, no significant differences for respiratory function and prognostic predictors were found. The multivariate analysis confirmed that occupational dust exposure did not affect neither FVC and DLCO after 12 month therapy nor the timing of LTOT initiation. CONCLUSION: Occupational dust exposure lasting 10 years or more does not seem to influence the therapeutic effects of antifibrotics and the prognostic predictors in patients with IPF

    Circulating microRNAs found dysregulated in ex-exposed asbestos workers and pleural mesothelioma patients as potential new biomarkers

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    Malignant pleural mesothelioma (MPM), a fatal cancer, is an occupational disease mostly affecting workers ex-exposed to asbestos fibers. The asbestos, a cancerogenic mineral of different chemical composition, was widely employed in western Countries in industrial manufactures of different types. MPM may arise after a long latency period, up to five decades. MPM is resistant to conventional chemo- and radio-therapies. Altogether, these data indicate that the identification of new and specific markers are of a paramount importance for an early diagnosis and treatment of MPM. In recent years, microRNAs expression was found dysregulated in patients, both in cancer cells and sera, affected by tumors of different histotypes, including MPM. Cell and circulanting microRNAs, found to be dysregulated in this neoplasia, were proposed as new biomarkers. It has been reported that circulating microRNAs are stable in biological fluids and could be employed as potential MPM biomarkers. In this investigation, circulating microRNAs (miR) from serum samples of MPM patients and workers ex-exposed to asbestos fibers (WEA) and healthy subjects (HS) were comparatively analyzed by microarray and RT-qPCR technologies. Our results allowed (i) to select MiR-3665, an endogenous stable microRNA, as the internal control to quantify in our analyses circulating miRNAs; to detect (ii) miR-197-3p, miR-1281 and miR 32-3p up-regulated in MPM compared to HS; (iii) miR-197-3p and miR-32-3p up-regulated in MPM compared to WEA; (iv) miR-1281 up-regulated in both MPM and WEA compared to HS. In conclusion, three circulating up-regulated microRNAs, i.e. miR-197-3p, miR-1281 and miR-32-3p are proposed as potential new MPM biomarker

    Breathlessness, but not cough, suggests chronic obstructive pulmonary disease in elderly smokers with stable heart failure.

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    Chronic obstructive pulmonary disease (COPD) is a common comorbidity of heart failure (HF), but remains often undiagnosed, and we aimed to identify symptoms predicting COPD in HF. As part of an observational, prospective study, we investigated stable smokers with a confirmed diagnosis of HF, using the 8-item COPD-Assessment-Test (CAT) questionnaire to assess symptoms. All the items were correlated with the presence of COPD, and logistic regression models were used to identify independent predictors. 96 HF patients were included, aged 74, 33% with COPD. Patients with HF and COPD were more symptomatic, but only breathlessness when walking up a hill was an independent predictor of COPD (odds ratio=1.33, p=0.0484). Interestingly, COPD-specific symptoms such as cough and phlegm were not significant. Thus, in elderly smokers with stable HF, significant breathlessness when walking up a hill is most indicative of associated COPD, and may indicate the need for further lung function evaluation

    Blood orange juice inhibits fat accumulation in mice

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    Objective: To analyze the effect of the juice obtained from two varieties of sweet orange (Citrus sinensis L. Osbeck), Moro (a blood orange) and Navelina (a blond orange), on fat accumulation in mice fed a standard or a high-fat diet (HFD). Methods: Obesity was induced in male C57/Bl6 mice by feeding a HFD. Moro and Navelina juices were provided instead of water. The effect of an anthocyanin-enriched extract from Moro oranges or purified cyanidin-3-glucoside (C3G) was also analyzed. Body weight and food intake were measured regularly over a 12-week period. The adipose pads were weighted and analyzed histologically; total RNA was also isolated for microarray analysis. Results: Dietary supplementation of Moro juice, but not Navelina juice significantly reduced body weight gain and fat accumulation regardless of the increased energy intake because of sugar content. Furthermore, mice drinking Moro juice were resistant to HFD-induced obesity with no alterations in food intake. Only the anthocyanin extract, but not the purified C3G, slightly affected fat accumulation. High-throughput gene expression analysis of fat tissues confirmed that Moro juice could entirely rescue the high fat-induced transcriptional reprogramming. Conclusion: Moro juice anti-obesity effect on fat accumulation cannot be explained only by its anthocyanin content. Our findings suggest that multiple components present in the Moro orange juice might act synergistically to inhibit fat accumulation

    Enhanced hydrogen production from thermochemical processes

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    To alleviate the pressing problem of greenhouse gas emissions, the development and deployment of sustainable energy technologies is necessary. One potentially viable approach for replacing fossil fuels is the development of a H2 economy. Not only can H2 be used to produce heat and electricity, it is also utilised in ammonia synthesis and hydrocracking. H2 is traditionally generated from thermochemical processes such as steam reforming of hydrocarbons and the water-gas-shift (WGS) reaction. However, these processes suffer from low H2 yields owing to their reversible nature. Removing H2 with membranes and/or extracting CO2 with solid sorbents in situ can overcome these issues by shifting the component equilibrium towards enhanced H2 production via Le Chatelier's principle. This can potentially result in reduced energy consumption, smaller reactor sizes and, therefore, lower capital costs. In light of this, a significant amount of work has been conducted over the past few decades to refine these processes through the development of novel materials and complex models. Here, we critically review the most recent developments in these studies, identify possible research gaps, and offer recommendations for future research
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