35 research outputs found

    Retrofitting partial oxyfuel and Integrated Ca-Looping technologies to an existing cement plant: a case study

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    The present document describes the potential retrofit of an existing cement plant with carbon capture technologies applied in two sequential steps. The pathway proposed consists in a first retrofit through partial oxyfuel followed by the integrated calcium looping (CaL) technology. This kind of applications may represent a promising strategy for the decarbonization route in the cement sector without introducing chemical solvents or special components, in particular for existing cement kilns that may need to be revamped. The cement plant selected for this study is the 0.5 Mtcem/y Colleferro facility owned by Italcementi-HeidelbergCement. This study analyses the mass & energy balances of the partial oxyfuel, and the integrated CaL process retrofitted to the existing cement plant. The results of the two CCS technologies are then compared in terms of CO2 emission reduction and energy consumption with the reference plant without CO2 capture. The scope of this analysis is to evaluate the impact of carbon capture technologies on the cement production process. The process simulation software Aspen Plus V10.0® has been employed to develop the model for the three different plant configurations (i.e., the base case w/o carbon capture, the partial oxyfuel mode, and the integrated CaL). The base case has been validated using field measurements coming directly from the Colleferro plant. From this process flow model, the two CCS technologies have been developed according to the specific process requirements. Results show that a maximum reduction in CO2 emissions of 92.4% is possible with the integrated CaL, while the partial oxyfuel enables to capture 71.7% of the CO2 generated in the plant

    Esophageal testing: What we have so far

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    Gastroesophageal reflux disease (GERD) is a common disorder of the gastrointestinal tract. In the last few decades, new technologies have evolved and have been applied to the functional study of the esophagus, allowing for the improvement of our knowledge of the pathophysiology of GERD. High-resolution manometry (HRM) permits greater understanding of the function of the esophagogastric junction and the risks associated with hiatal hernia. Moreover, HRM has been found to be more reproducible and sensitive than conventional water-perfused manometry to detect the presence of transient lower esophageal sphincter relaxation. Esophageal 24-h pH-metry with or without combined impedance is usually performed in patients with negative endoscopy and reflux symptoms who have a poor response to anti-reflux medical therapy to assess esophageal acid exposure and symptom-reflux correlations. In particular, esophageal 24-h impedance and pH monitoring can detect acid and non-acid reflux events. EndoFLIP is a recent technique poorly applied in clinical practice, although it provides a large amount of information about the esophagogastric junction. In the coming years, laryngopharyngeal symptoms could be evaluated with up and coming non-invasive or minimally invasive techniques, such as pepsin detection in saliva or pharyngeal pH-metry. Future studies are required of these techniques to evaluate their diagnostic accuracy and usefulness, although the available data are promising

    Lopinavir/Ritonavir and Darunavir/Cobicistat in Hospitalized COVID-19 Patients: Findings From the Multicenter Italian CORIST Study

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    Background: Protease inhibitors have been considered as possible therapeutic agents for COVID-19 patients. Objectives: To describe the association between lopinavir/ritonavir (LPV/r) or darunavir/cobicistat (DRV/c) use and in-hospital mortality in COVID-19 patients. Study Design: Multicenter observational study of COVID-19 patients admitted in 33 Italian hospitals. Medications, preexisting conditions, clinical measures, and outcomes were extracted from medical records. Patients were retrospectively divided in three groups, according to use of LPV/r, DRV/c or none of them. Primary outcome in a time-to event analysis was death. We used Cox proportional-hazards models with inverse probability of treatment weighting by multinomial propensity scores. Results: Out of 3,451 patients, 33.3% LPV/r and 13.9% received DRV/c. Patients receiving LPV/r or DRV/c were more likely younger, men, had higher C-reactive protein levels while less likely had hypertension, cardiovascular, pulmonary or kidney disease. After adjustment for propensity scores, LPV/r use was not associated with mortality (HR = 0.94, 95% CI 0.78 to 1.13), whereas treatment with DRV/c was associated with a higher death risk (HR = 1.89, 1.53 to 2.34, E-value = 2.43). This increased risk was more marked in women, in elderly, in patients with higher severity of COVID-19 and in patients receiving other COVID-19 drugs. Conclusions: In a large cohort of Italian patients hospitalized for COVID-19 in a real-life setting, the use of LPV/r treatment did not change death rate, while DRV/c was associated with increased mortality. Within the limits of an observational study, these data do not support the use of LPV/r or DRV/c in COVID-19 patients

    Ab initio quartic force field of stannane and rotational analysis of the \u3bd1 infrared band of H120SnD3

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    Stannane, SnH4, has been studied both theoretically, using high-level ab initio methods, and experimentally, using high-resolution spectroscopy to analyze the Sn-H stretching fundamental band of the (HSnD3)-Sn-120 isotopologue. The geometry and the anharmonic force field of the molecule have been calculated ab initio, using the coupled-cluster with single, double, and perturbative triple excitations level of theory. (HSnD3)-Sn-120, present as minor isotopologue in (SnD4)-Sn-120, has been studied by Fourier transform spectroscopy at an effective resolution of ca. 0.005 cm(-1) near 1900 cm(-1) and the nu(1) band was identified. About 360 ro-vibration transitions with J' up to 18 and K up to 10 have been assigned. Since the spectrum evidenced the existence of some perturbations, the transitions were analyzed either neglecting, or including in the model A(1)/E Coriolis-type interactions with nearby dark states. The standard deviation of the fits, ca. 1.5 x 10(-3) cm(-1), is about one order of magnitude larger than the estimated experimental precision, and is only slightly dependent on the adopted model. The spectroscopic parameters obtained from this and from previous analyses of stannane isotopologues have been compared with the theoretical results. The theoretical force field is also used to obtain semi-experimental harmonic frequencies and the equilibrium geometry

    Sealing of PEO coated AZ91 magnesium alloy using la-based solutions

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    In this work, solutions containing lanthanum salts were used for a post-treatment of sealing to increase the corrosion resistance of PEO coated AZ91 alloy. PEO coatings were produced on samples of AZ91 magnesium alloy using an alkaline solution containing sodium hydroxide, sodium phosphates, and sodium silicates. The sealing treatment was performed in a solution containing 12 g/L of La(NO3)3 at pH 4 at different temperatures and for different treatment times. Potentiodynamic polarization test, an EIS test, showed that the sealing treatment with solution containing lanthanum nitrate caused a remarkable increase in the corrosion resistance. The corrosion behavior was correlated with the surface morphology and elemental composition evaluated with scanning electron microscope (SEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). In particular, the sealing treatment at 50°C for 30 min resulted in being the most promising to increase the corrosion properties of PEO treated samples because of the formation of a homogeneous sealing layer, mainly composed of La(OH)3

    Density and Viscosity Measurements and Modeling of CO2-Loaded and Unloaded Aqueous Solutions of Potassium Lysinate

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    International audienceThis paper reports new experimental data and calibrated semiempirical correlations concerning the density and viscosity of aqueous solutions of potassium lysinate (LysK), a promising bio-based solvent for postcombustion CO2 capture from flue gases, an application of relevance for industrial decarbonization. The analysis covers a LysK molality range in the solution from 2.16 to 4.44 molLysK/kgH2O, temperature intervals between 288.15 and 358.15 K, and a CO2 loading range of 0.3–0.98 molCO2/molLysK. Newly collected experimental results supported the development and calibration of semiempirical correlations for the density and viscosity of LysK solutions suitable to predict these thermophysical properties in the range of conditions tested. These models can predict the behavior of the thermophysical properties investigated with high accuracy (for loaded solutions, average absolute deviation for density equal to 1.48 kg/m3 and for viscosity of 0.04 mPa s) within the whole range of LysK concentration, temperature, and CO2 loading explored. Validation against literature data lying outside the calibration range shows an accuracy for density correlation ≤3%, while for the viscosity model, deviations are larger and vary between 1 and 15% of the measured value

    Biclustering with a quantum annealer

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    Several problem in Artificial Intelligence and Pattern Recognition are computationally intractable due to their inherent complexity and the exponential size of the solution space. One example of such problems is biclustering, a specific clustering problem where rows and columns of a data-matrix must be clustered simultaneously. Quantum information processing could provide a viable alternative to combat such a complexity. A notable work in this direction is the recent development of the D-Wave computer, whose processor has been designed to the purpose of solving Quadratic Unconstrained Binary Optimization (QUBO) problems. In this paper, we investigate the use of quantum annealing by providing the first QUBO model for biclustering and a theoretical analysis of its properties (correctness and complexity). We empirically evaluated the accuracy of the model on a synthetic data-set and then performed experiments on a D-Wave machine discussing its practical applicability and embedding propertie
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