The benefit of high-conductivity materials in film cooled turbine nozzles

This study presents an experimental and numerical investigation of the beneficial effect of higher conductivity materials in HP turbine nozzles. Most of the literature studies focus on the maximum temperature that a nozzle can withstand, whereas the effect of thermal gradients is often neglected. However thermal gradients have higher influence on the life of the components and they have to be given careful consideration. In this work it is shown that thermal gradients are reduced by using high conductivity materials and, as a consequence, the nozzles life is appreciably increased. A representative film cooled leading edge with an internal impingement plate was studied experimentally at Texas AM University. Two materials were used, namely polycarbonate and stainless steel, in order to highlight the impact of conduction on coolant effectiveness. Numerically conjugate heat transfer simulations have been carried out with an in house solver to analyse in detail the impact of conduction and internal convection. Both experimental and numerical results show that by increasing the conductivity in the solid region, the thermal gradients are strongly reduced. Numerically it is shown that using inserts of nickel-aluminide alloys in nozzles may reduce the thermal gradients from 3 to 4 times if compared to nowadays design. © 2012 Elsevier Inc

Neural network topology for wind turbine analysis

In this work Artificial Neural Networks (ANN) are used for a multi-target optimization of the aerodynamics of a wind turbine blade. The Artificial Neural Network is used to build a meta-model of the blade, which is then optimized according to the imposed criteria. The neural networks are trained with a data set built by a series of CFD simulations and their configuration (number of neurons and layers) selected to improve performances and avoid over-fitting. The basic configuration of the airfoil is the profile S809, which is commonly used in horizontal axis wind turbines (HAWT), equipped with a Coanda jet. The design position and momentum of the jet are optimized to maximize aerodynamic efficiency and minimize the power required to activate the Coanda Jet

A nonlinear, data-driven, ANNs-based approach to culture-led development policies in rural areas: The case of Gjakove and Pee districts, Western Kosovo

We develop a computational approach to the analysis of cultural vibrancy and to the role of the cultural and cre-ative sectors in the socio-economic organization of two districts of Western Kosovo, Gjakove and Pee. Our anal-ysis is built on a geolocalized mapping of the cultural activities and facilities, and on the main socio-economic variables for the two districts, and makes use of innovative data analysis techniques: Theory of Impossible Words (TIW), the Topological Weighted Centroid (TWC), and the AutoCM ANN. We find that the dynamics of cul-tural vibrancy of the territory is mainly driven by the competing attraction pulls of the nearby countries of Serbia and Albania, that also form the region's main and often conflicting ethnicities, and that such dynamics are likely to further polarize in the future. We also find that the cultural system plays a marginal role in the territory's socio-economic organization. This situation makes a case for a more active role of cultural policy in shaping future local developmental models in rural areas and in acting as an agent of social cohesion.(c) 2022 Elsevier Ltd. All rights reserved

Intention to be vaccinated for COVID-19 among italian nurses during the pandemic

Background: While the COVID-19 pandemic has spread globally, health systems are overwhelmed by both direct and indirect mortality from other treatable conditions. COVID-19 vaccination was crucial to preventing and eliminating the disease, so vaccine development for COVID-19 was fast-tracked worldwide. Despite the fact that vaccination is commonly recognized as the most effective approach, according to the World Health Organization (WHO), vaccine hesitancy is a global health issue. Methods: We conducted a cross-sectional online survey of nurses in four different regions in Italy between 20 and 28 December 2020 to obtain data on the acceptance of the upcoming COVID-19 vaccination in order to plan specific interventions to increase the rate of vaccine coverage. Results: A total of 531 out of the 5000 nurses invited completed the online questionnaire. Most of the nurses enrolled in the study (73.4%) were female. Among the nurses, 91.5% intended to accept vaccination, whereas 2.3% were opposed and 6.2% were undecided. Female sex and confidence in vaccine efficacy represent the main predictors of vaccine intention among the study population using a logistic regression model, while other factors including vaccine safety concerns (side effects) were non-significant. Conclusions: Despite the availability of a safe and effective vaccine, intention to be vaccinated was suboptimal among nurses in our sample. We also found a significant number of people undecided as to whether to accept the vaccine. Contrary to expectations, concerns about the safety of the vaccine were not found to affect the acceptance rate; nurses’ perception of vaccine efficacy and female sex were the main influencing factors on attitudes toward vaccination in our sample. Since the success of the COVID-19 immunization plan depends on the uptake rate, these findings are of great interest for public health policies. Interventions aimed at increasing employee awareness of vaccination efficacy should be promoted among nurses in order to increase the number of vaccinated people

Quantum Characterization of a Werner-like Mixture

We introduce a Werner-like mixture [R. F. Werner, Phys. Rev. A {\bf 40}, 4277 (1989)] by considering two correlated but different degrees of freedom, one with discrete variables and the other with continuous variables. We evaluate the mixedness of this state, and its degree of entanglement establishing its usefulness for quantum information processing like quantum teleportation. Then, we provide its tomographic characterization. Finally, we show how such a mixture can be generated and measured in a trapped system like one electron in a Penning trap.Comment: 8 pages ReVTeX, 8 eps figure

Fossil Geyserite and Testate Amoebae in Geothermal Spring Vent Pools: Paleoecology and Variable Preservation Quality in Jurassic Sinter of Patagonia (Deseado Massif, Argentina)

ABSTRACT Geyserite is a type of terrestrial siliceous hot spring deposit (sinter) formed subaerially in proximal vent areas, with near-neutral pH, alkali chloride discharge fluids characterized by initial high temperatures (~73°C to up to 100°C) that fluctuate rapidly in relation to dynamic hydrology, seasonality, wind, and other environmental parameters. We analyzed sinters at the Claudia paleogeothermal field from the Late Jurassic (~150?Ma) Deseado Massif geological province, Argentinean Patagonia. The geyserite samples?with spicular to columnar to nodular morphologies?contain abundant microfossils in monotypic assemblages that occur in three diagenetic states of preservation. The best-preserved microfossils consist of vesicle-like structures with radial heteropolar symmetry (~35??m average diameter), circular apertures, smooth walls lacking ornamentation, and disk- or beret-like shapes. Comparisons with extant, morphologically similar organisms suggest an affinity with the testate amoebae of the Arcella hemisphaerica?Arcella rotundata complex and Centropyxis aculeata strain discoides. These species occur in active geothermal pools between 22°C and 45°C, inconsistent with the temperature of formation of modern geyserites. We propose that the testate amoebae may have colonized the geyserite during cooler phases in between spring-vent eruptive cycles to prey on biofilms. Silica precipitation through intermittent bathing and splashing of fluctuating thermal fluid discharge could have led to their entrapment and fossilization. Petrographic analysis supports cyclicity in paleovent water eruptions and later diagenesis that transformed the opal into quartz. Spatially patchy degradation and modification of the silicified microorganisms resulted in variable preservation quality of the microfossils. This contribution illustrates the importance of microscale analysis to locate early silicification and identify high-quality preservation of fossil remains in siliceous hot spring deposits, which are important in early life studies on Earth and potentially Mars

Photosynthesis

Although there has been considerable progress toward an understanding of the processes of photosyntehsis in recent years, the advances have been followed rather lcosely by symposia, monographs and reviews of the subject matter, particularly during the last three years. In view of the comprehensive coverage it would appear that the present review might very well be limited to a discussion of certain subjects of special interest to the authors and some with which they are especially familiar. These are (1) the extensive discussion by Warburg and his co-workers of their proposal for the existence of a light induced oxygen absorption (and corresponding carbon dioxide evolution) which can amount to three or four times the net oxygen evolution by the same light; and (2) the discovery of the early participation of 7 and 5 carbon sugars in carbon dioxide reduction in photosyntehsis together with some observations on the kinetics of the metabolic transformations. While it is true that a considerable number of significant publications have appears in other aspects of photosynthesis (the Hill reaction and its coupling with carbon dioxide reduction; photochemistry of chlorophyll and related synthetic materials as model reactions in relatively simple defined physical systems; transfer of light energy within the pigment systems) it is felt that they represent confirmation and extension of ideas which have already been discussed in a variety of earlier reviews and that a re-evaluation of them might very well be postponed until a later time

Synthesis and characterization of entangled mesoscopic superpositions for a trapped electron

We propose a scheme for the generation and reconstruction of entangled states between the internal and external (motional) degrees of freedom of a trapped electron. Such states also exhibit quantum coherence at a mesoscopic level.Comment: 4 pages, 1 figure, RevTeX (twocolumn