The interaction between NH3, CH4 and NO under different conditions of interest for combustion applications is analyzed, from both experimental and kinetic modeling points of view. Reduction of NO by ...reburn and by SNCR (selective non-catalytic reduction) strategies is evaluated, through an extense systematic study of the influence of the main variables of interest for NO reduction, by means of laboratory flow-reactor experiments at atmospheric pressure. Variables analyzed include: temperature in the 700 to 1500 K range, air stoichiometry from fuel-rich (λ = 0.31) to fuel-lean conditions (λ = 2.21), NH3/CH4 ratio in the 0.4 to 10.78 range, NH3/NO ratio in the 0.49 to 2.60 range the, and CH4/NO ratio in the 0.37 to 1.98 range, dilution level, and bath gas by using nitrogen and argon, the latter to allow the precise determination of nitrogen balances. Results are interpreted using a literature reaction mechanism, together with reaction pathway analysis tools, and the main findings are discussed. Results indicate that ammonia promotes the conversion of methane, while methane inhibits the conversion of ammonia, due to the competition for radicals of both components in the mixture. The interaction of ammonia and methane implies that the reduction of NO by NH3/CH4 mixtures is comparatively lower than the reduction obtained by NH3 and CH4 independently. Implications for practical applications of the reduction of NO by the studied mixtures are discussed.
Macrophage activation syndrome in COVID-19 Grigorieva, K. N.; Bitsadze, V. O.; Khizroeva, J. Kh ...
Akušerstvo, ginekologiâ i reprodukciâ,
07/2021, Letnik:
15, Številka:
3
Journal Article
Recenzirano
Odprti dostop
The novel coronavirus epidemic is characterized by high rates of morbidity and relatively high mortality. Laboratory test results in patients include leukopenia, an increase in liver function tests ...and ferritin levels reaching hundreds, and sometimes thousands of units. These data remind us about the macrophage activation syndrome (MAC). Secondary hemophagocytic lymphohistiocytosis syndrome, MAC, which pathogenesis is based on a defect in the mechanisms of T-cell cytotoxicity and decreased level of natural killer cells associated with the defect in the perforin-encoding gene as well as hyperproduction of a number of cytokines – interleukin (IL)-1â, tumor necrosis factor-á, etc. by T-lymphocytes and histiocytes, indirectly leading to the activation of macrophages and production of proinflammatory cytokines, in particular IL-6 hyperproduction. MAC is one of "hyperferritinemic syndromes". These disorders have similar clinical and laboratory manifestations, and they also respond to similar treatments, suggesting that hyperferritinemia may be involved in the overall pathogenesis and is characterized by elevated ferritin level and cytokine storm. Despite the fact that data on the immune and inflammatory status in patients with COVID-19 have only started to appear, it is already clear that hyperinflammation and coagulopathy affect the disease severity and increase the risk of death in patients infected with SARS-CoV-2. Hence, understanding the pathogenesis of the novel coronavirus infection can help in its early diagnostics and treatment.
The effect of substrate temperature on the direct current magnetron‐sputtered zirconium oxide (ZrO2) dielectric films was investigated. Stoichiometric of the ZrO2 thin films was obtained at an oxygen ...partial pressure of 4.0 × 10−2 Pa. X‐ray diffraction studies revealed that the crystallite size in the layer was increased from 4.8 to 16.1 nm with increase of substrate temperature from 303 to 673 K. Metal‐oxide‐semiconductor devices were fabricated on ZrO2/Si stacks with Al gate electrode. The dielectric properties of ZrO2 layer and interface quality at ZrO2/Si were significantly influenced by the substrate temperature. The dielectric constant increased from 15 to 25, and the leakage current density decreased from 0.12 × 10−7 to 0.64 × 10−9 A cm−2 with the increase of substrate temperature from 303 to 673 K.
Objective The objective of the study was to compare neonatal morbidity and long-term neurodevelopmental outcome between very preterm infants with placental underperfusion and very preterm infants ...with histological chorioamnionitis. Study Design We measured the mental and motor development at age 2 and 7 years in 51 very preterm infants with placental underperfusion and 21 very preterm infants with histological chorioamnionitis. Results At 2 years, very preterm infants with placental underperfusion had poorer mental development than very preterm infants with histological chorioamnionitis (mean SD 90.8 18.3 vs 104.1 17.2, adjusted d = 1.12, P = .001). Motor development was not different between both groups (92.8 17.2 vs 96.8 8.7, adjusted d = 0.52, P = .12). At 7 years, large, although nonsignificant, effects were found for better mental and motor development and fewer behavioral problems in infants with histological chorioamnionitis. Conclusion Placental pathology contributes to variance in mental development at 2 years and should be taken into account when evaluating neurodevelopmental outcome of very preterm infants.
Thread-parallelisation and single-instruction multiple data (SIMD) "vectorisation" of software components in HEP computing has become a necessity to fully benefit from current and future computing ...hardware. In this context, the Geant-Vector GPU simulation project aims to re-engineer current software for the simulation of the passage of particles through detectors in order to increase the overall event throughput. As one of the core modules in this area, the geometry library plays a central role and vectorising its algorithms will be one of the cornerstones towards achieving good CPU performance. Here, we report on the progress made in vectorising the shape primitives, as well as in applying new C++ template based optimisations of existing code available in the Geant4, ROOT or USolids geometry libraries. We will focus on a presentation of our software development approach that aims to provide optimised code for all use cases of the library (e.g., single particle and many-particle APIs) and to support different architectures (CPU and GPU) while keeping the code base small, manageable and maintainable. We report on a generic and templated C++ geometry library as a continuation of the AIDA USolids project. The experience gained with these developments will be beneficial to other parts of the simulation software, such as for the optimisation of the physics library, and possibly to other parts of the experiment software stack, such as reconstruction and analysis.
This paper is describing an investigation of surfactants influence on zinc sulfide wetting by non-polar liquids and sphalerite concentrates pressure leaching parameters. Zinc sulfide preferential ...wettability by oil was tested in presence anionic surfactants with different chemical structures. Interfacial tension was determinated by the maximum liquid drop volume method. It allows to determine surfactant potential effectivity on pressure leaching of sphalerite concentrate. It is found that SDBS decreases zinc sulfide wettability by non-polar liquids in a greater degree than SDS and Ls. Combined addition of Ls and SDBS allowed to receive residues with optimal coarseness, eliminate pellet formation and increase zinc extraction.
The GeantV project is focused on the R&D of new particle transport techniques to maximize parallelism on multiple levels, profiting from the use of both SIMD instructions and co-processors for the ...CPU-intensive calculations specific to this type of applications. In our approach, vectors of tracks belonging to multiple events and matching different locality criteria must be gathered and dispatched to algorithms having vector signatures. While the transport propagates tracks and changes their individual states, data locality becomes harder to maintain. The scheduling policy has to be changed to maintain efficient vectors while keeping an optimal level of concurrency. The model has complex dynamics requiring tuning the thresholds to switch between the normal regime and special modes, i.e. prioritizing events to allow flushing memory, adding new events in the transport pipeline to boost locality, dynamically adjusting the particle vector size or switching between vector to single track mode when vectorization causes only overhead. This work requires a comprehensive study for optimizing these parameters to make the behaviour of the scheduler self-adapting, presenting here its initial results.
In this paper, the authors consider the mechanisms of formation of high-strength states in the Zn–1%Li–2%Mg alloy as a result of its processing by the high pressure torsion (HPT) method. For the ...first time, the study showed that using HPT treatment, as a result of varying the degree of deformation at room temperature, it is possible to increase the ultimate strength of a zinc alloy from 155 to 383 MPa (with an increase in the yield stress from 149 to 306 MPa) without losing its ductility. To explain the reasons for the increase in the zinc alloy mechanical properties, its microstructure was analyzed by scanning electron microscopy (SEM), X-ray phase analysis (XPA), X-ray diffraction analysis (XRD), and small-angle X-ray scattering (SAXS). Using XPA, the authors established for the first time that Zn(eutectic)+β-LiZn4(eutectic)→~LiZn3+Zn(phase)+Zn(precipitation) and MgZn2→Mg2Zn11 phase transformations occur in the zinc alloy during HPT treatment. SEM analysis showed that at the initial stages of HPT treatment, cylindrical Zn particles with a diameter of 330 nm and a length of up to 950 nm precipitate in β-LiZn3 phase. At the same time, the SAXS method showed that needle-like LiZn4 particles with a diameter of 9 nm and a length of 28 nm precipitate in the Zn phase. The study established that, only spherical Zn and LiZn4 particles precipitate at high degrees of HPT treatment. Precision analysis of the zinc alloy microstructure showed that HPT treatment leads to grain refinement, an increase in the magnitude of crystal lattice microdistortion, a growth of the density of dislocations, which are predominantly of the edge type. As a result of the analysis of hardening mechanisms, the authors concluded that the increase in the zinc alloy strength characteristics mainly occurs due to grain-boundary, dislocation, and dispersion hardening.
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