Numerical study of ignition and combustion of hydrogen-enriched methane in a sequential combustor

Ignition and combustion behavior in the second stage of a sequential combustor are investigated numerically at atmospheric pressure for pure CH4 fueling and for a CH4/H2 fuel blend in 24:1 mass ratio using Large Eddy Simulation (LES). Pure CH4 fueling results in a turbulent propagating flame anchored by the hot gas recirculation zone developed near the inlet of the sequential combustion chamber. Conversely, CH4/H2 fueling results in a drastic change of the combustion process, with multiple auto-ignition kernels produced upstream of the main flame brush. Chemical Explosive Mode Analysis indicates that, when H2 is added, flame stabilization in the combustion chamber is strongly supported by auto-ignition chemistry. The analysis of fuel decomposition pathways highlights that radicals advected from the first stage flame, in particular OH, induce a rapid fuel decomposition and cause the reactivity enhancement that leads to auto-ignition upstream of the sequential flame. This behavior is promoted by the relatively large mass fraction of OH radicals found in the flow reaching the second stage, which is approximately one order of magnitude greater than it would be at chemical equilibrium. The importance of the out-of-equilibrium vitiated air on the ignition behavior is proven via an additional LES that features weak auto-ignition kernel formation when equilibrium is artificially imposed. It is concluded, therefore, that parameters affecting the relaxation towards chemical equilibrium of the vitiated flow can have an important influence on the operability of sequential combustors fueled with varying fractions of H2 blending

Sull’impugnazione del decreto che apre il concordato preventivo senza disporre la prededuzione dei crediti

LaCassazione affronta, per la prima, volta, il problema dell’impugnazione del decreto che, dichiarando ammissibile il concordato preventivo, non abbia disposto la prededuzione dei crediti previsti dall’art. 182 quater l.fall. Nonostante l’abrogazione del comma 4 della norma, relativo al credito del professionista che abbia redatto la relazione di attestazione del piano, la questione di massima conserva rilievo con riguardo ai crediti derivanti dai finanziamenti-ponte di cui al comma 2 della norma, giustificando l’intervento in funzione nomofilattica della Suprema Corte

Decisioni della Cassazione (impugnazione delle)

Il tema dell’impugnazione delle decisioni della Corte di Cassazione si è imposto all’attenzione degli studiosi del processo civile in tempi relativamente recenti, ma, soprattutto negli ultimissimi anni, ha conosciuto un’evoluzione normativa e giurisprudenziale molto rapida. La materia è intuitivamente di grande delicatezza, poiché vengono in rilievo, entrando in reciproco conflitto, diversi valori essenziali della giurisdizione. Da una parte sta l’esigenza di garantire la funzionalità del processo e l’intangibilità del giudicato, assicurando che le liti mettano capo, in tempi ragionevoli, a una pronuncia tendenzialmente irretrattabile. Dall’altra, occorre considerare la posizione di vertice della Corte di cassazione, che la Costituzione istituisce quale supremo custode della legalità e dei rapporti tra le giurisdizioni, sottraendola per ciò stesso al sindacato di ogni altro giudice. Da un’altra parte ancora, vi è la necessità, non meno cogente, di salvaguardare il diritto alla difesa, che rappresenta un presidio inviolabile in ogni stato e grado del processo. Infine — e forse più di tutto — i principi di uguaglianza e di razionalità normativa sanciti dall’art. 3 della Carta fondamentale impongono di non discriminare situazioni processuali analoghe: in particolare, in subiecta materia si tratta di non differenziare indebitamente il trattamento delle decisioni della Cassazione rispetto a quelle dei giudici di merito, qualora le prime non presentino un contenuto obiettivamente diverso dalle seconde. La voce enciclopedica si sofferma su tutti gli aspetti – sistematici e più strettamente procedimentali – della disciplina della revocazione e dell’opposizione di terzo delle decisioni della Cassazione, senza rinunziare a una riflessione critica d’insieme sul sistema vigente

Temporal effects of Sprouty on lung morphogenesis

AbstractParacrine signaling mediated by FGF-10 and the FGF-R2IIIb receptor is required for formation of the lung. To determine the temporal requirements for FGF signaling during pulmonary morphogenesis, Sprouty-4 (Spry-4), an intracellular FGF receptor antagonist, was expressed in epithelial cells of the fetal lung under control of a doxycycline-inducible system. Severe defects in lobulation and severe lung hypoplasia were observed when Spry-4 was expressed throughout fetal lung development (E6.5–E18.5) or from E6.5 until E13.5. Effects of Spry-4 on branching were substantially reversed by removal of doxycycline from the dam at E12.5, but not at E13.5. In contrast, when initiated late in development (E12.5 to birth), Spry-4 caused less severe pulmonary hypoplasia. Expression of Spry-4 from E16.5 to E18.5 reduced lung growth and resulted in perinatal death due to respiratory failure. Expression of Spry-4 during the saccular and alveolar stages, from E18.5 to postnatal day 21, caused mild emphysema. These findings demonstrate that the embryonic-pseudoglandular stage is a critical time period during which Spry-sensitive pathways are required for branching morphogenesis, lobulation, and formation of the peripheral lung parenchyma

Intralobar Pulmonary Sequestration and Increased Serum CA 19-9

Intralobar pulmonary sequestration is an uncommon congenital lung anomaly which consists of a mass of normal lung tissue not connected to the normal tracheobronchial tree and supplied by an anomalous systemic artery. Carbohydrate antigen 19-9 (CA 19-9) is widely accepted as a tumour marker for biliary, pancreatic and gastrointestinal cancer. However, CA 19-9 may also be increased in patients with benign disease. We describe the case of a 56-year-old woman with intralobar pulmonary sequestration who underwent unnecessary and extensive diagnostic abdominal examinations because of an increase in CA 19-9 serum levels

A new approach to antiglaucoma drugs: carbonic anhydrase inhibitors with or without NO donating moieties. Mechanism of action and preliminary pharmacology.

The clinically used sulfonamide carbonic anhydrase (CA, EC 4.2.1.1) inhibitor dorzolamide (DRZ), a new sulfonamide CA inhibitor also incorporating NO-donating moieties, NCX250, and isosorbide mononitrate (ISMN) (an NO-donating compound with no CA inhibitory properties) were investigated for their intraocular pressure (IOP) lowering effects in rabbits with carbomer-induced glaucoma. NCX250 was more effective than DRZ or ISMN on lowering IOP, increasing ocular hemodynamics, decreasing the inflammatory processes and ocular apoptosis in this animal model of glaucoma. NO participate to the regulation of IOP in glaucoma, having also antiapoptotic and anti-inflammatory effects. The ophthalmic artery, both systolic and diastolic velocities, were significantly reduced in NCX250-treated eyes in comparison to DRZ treated ones, suggesting thus a beneficial effect of NCX250 on the blood supply to the optic nerve. Combining CA inhibition with NO-donating moieties in the same compound offers an excellent approach for the management of glaucoma

Experience and Time: A Metaphysical Approach

What is the temporal structure of conscious experience? While it is popular to think that our most basic conscious experiences are temporally extended, we will be arguing against this view, on the grounds that it makes our conscious experiences depend on the future in an implausible way. We then defend an alternative view of the temporal structure of experience from a variety of different objections. Along the way, we hope to illustrate the wider philosophical ramifications of the relationship between experience and time. What one thinks about the temporal structure of experience is, we believe, deeply interconnected with issues concerning whether consciousness is vague or precise, whether conscious states can be reduced to physical states, whether phenomenal properties are intrinsic properties, and whether phenomenal consciousness can “overflow” access consciousness. As we will see, even seemingly unrelated metaphysical questions, such as the debate between Humean and Non-Humean accounts of natural necessity, bear on questions about the relationship between experience and time

An Empirical Argument for Presentism

According to orthodoxy, our best physical theories strongly support Eternalism over Presentism. Our goal is to argue against this consensus, by arguing that a certain overlooked aspect of our best physical theories strongly supports Presentism over Eternalism

Nanoprobes to interrogate nonspecific interactions in lipid bilayers: from defect-mediated adhesion to membrane disruption

When a lipid membrane approaches a material/nanomaterial, nonspecific adhesion may occur. The interactions responsible for nonspecific adhesions can either preserve the membrane integrity or lead to its disruption. Despite the importance of the phenomenon, there is still a lack of clear understanding of how and why nonspecific adhesions may originate different resulting scenarios and how these interaction scenarios can be interrogated. This work aims at bridging this gap by investigating the interplay between cationic electrostatic and hydrophobic interactions in modulating the membrane stability during nonspecific adhesion phenomena. Here, the stability of the membrane has been studied employing anisotropic nanoprobes in zwitterionic lipid membranes with the support of coarse-grained molecular dynamics simulations to interpret the experimental observations. Lipid membrane electrical measurements and nanoscale visualization in combination with molecular dynamics simulations revealed the phenomena driving nonspecific adhesion. Any interaction with the lipidic bilayer is defect-mediated involving cationic electrostatically-driven lipid extractions and hydrophobicallydriven chains protrusion, whose interplay determines the existence of a thermodynamic optimum for the membrane structural integrity. These findings unlock unexplored routes to exploit nonspecific adhesion in lipid membranes. The proposed platform can act as a straightforward probing tool to locally interrogate interactions between synthetic materials and lipid membranes for the design of antibacterials, antivirals, and scaffolds for tissue engineering

Persistent behavioral sensitization to chronic L-DOPA requires A2A adenosine receptors

To investigate the role of A2A adenosine receptors in adaptive responses to chronic intermittent dopamine receptor stimulation, we compared the behavioral sensitization elicited by repeated L-DOPA treatment in hemiparkinsonian wild-type (WT) and A2A adenosine receptor knock-out (A2A KO) mice. Although the unilateral nigrostriatal lesion produced by intrastriatal injection of 6-hydroxydopamine was indistinguishable between WT and A2A KO mice, they developed strikingly different patterns of behavioral sensitization after daily treatment with low doses of L-DOPA for 3 weeks. WT mice initially displayed modest contralateral rotational responses and then developed progressively greater responses that reached a maximum within 1 week and persisted for the duration of the treatment. In contrast, any rotational behavioral sensitization in A2A KO mice was transient and completely reversed within 2 weeks. Similarly, the time to reach the peak rotation was progressively shortened in WT mice but remained unchanged in A2A KO mice. Furthermore, daily L-DOPA treatment produced gradually sensitized grooming in WT mice but failed to induce any sensitized grooming in A2A KO mice. Finally, repeated L-DOPA treatment reversed the 6-OHDA-induced reduction of striatal dynorphin mRNA in WT but not A2A KO mice, raising the possibility that the A2A receptor may contribute to L-DOPA-induced behavioral sensitization by facilitating adaptations within the dynorphin-expressing striatonigral pathway. Together these results demonstrate that the A2A receptor plays a critical role in the development and particularly the persistence of behavioral sensitization to repeated L-DOPA treatment. Furthermore, they raise the possibility that the maladaptive dyskinetic responses to chronic L-DOPA treatment in Parkinson's disease may be attenuated by A2A receptor inactivation.Peer Reviewe