Numerical analysis of hydrofoil ventilated cavitation under wave impact

Unsteady ventilated cavitation of a hydrofoil is analyzed with coupling of the perturbed steady two-dimensional incompressible flow of water out of the cavity and the compressible one-dimensional air flow within the cavity. The air flux from cavity at its oscillating tail and along its side boundary with the water is taken into account. The employed equations include air mass conservation law and pressure constancy condition along the cavity in both media. On the cavity boundary, however, the impermeability condition is considered from the water side and the differential momentum equation from the air side. The developed model of ventilated cavitation has been verified with the already published [1] measurements of hydrodynamic loads and their pulsations on the low-drag partially cavitating hydrofoil OK-2003A satisfactory agreement of the computed results with experimental data was manifested. Influence of the wavelength variations and air compressibility on lift and its pulsations were analyzed.http://deepblue.lib.umich.edu/bitstream/2027.42/84258/1/CAV2009-final8.pd

Effects of surface characteristics on hydrofoil cavitation

This was an exploratory research project aimed at capitalizing on our recent research experience with unsteady partially cavitating flows. Earlier work identified the significant and unexpected effect of surface properties and water quality on the dynamics of these flows. The aim of this study was to explore the possibility of using hydrophobic surfaces to control or minimize unwanted vibration and unstable operation in the partially cavitating regime. A candidate shape, denoted as the Cav2003 hydrofoil, was selected on the basis of theoretical analysis for a given range of contact angle. We manufactured three hydrofoils of identical cross section, but different surface characteristics. Three different surfaces were studied: anodized aluminium (hydrophilic), Teflon (hydrophobic), and highly polished stainless steel (hydrophobic). Contact angle was measured with a photographic technique developed by three of the undergraduates working on the project. Studies were made in both weak and strong water. Significant surface effects were found, but were unexpected in the sense that they did not correlate with measured contact angles.http://deepblue.lib.umich.edu/bitstream/2027.42/84293/1/CAV2009-final112.pd

Analysis of the Airfoil Stall With a Modification of Viscous-Inviscid Interaction Concept

A modification of the viscous-inviscid interaction concept with the employment of coupled vortices around the airfoil wake is introduced for analyzing the airfoil stall. The analyzed flow includes the laminar boundary layers, laminar separation bubble, laminar-turbulent transition zone, turbulent boundary layers, turbulent separation zone, wake, and outer inviscid flow. Integral methods are employed for the boundary layers. The boundaries of separation zones are analyzed as free surfaces, however, their lengths and shapes depend on the Reynolds number. The described modification is validated by a comparison of the numerical results with the previously published experimental data for various airfoils and Reynolds numbers at low Mach numbers. This modification achieves a reasonably good agreement of the computed lift and moment coefficients with their measured values

Electron microscopy study on the transport of lead oxide nanoparticles into brain structures following their subchronic intranasal administration in rats

White outbred female rats were exposed intranasally to 50-µL of suspension of lead oxide nanoparticles (PbO NPs) at a concentration of 0.5 mg/mL thrice a week during six weeks. A control group of rats was administered deionized water in similar volumes and conditions. The developed intoxication was manifested by altered biochemical and cytochemical parameters, as well as behavioral reactions of animals. Using electron microscopy and energy-dispersive X-ray spectroscopy techniques, we revealed deposition of PbO NPs in the olfactory bulb, but not in basal ganglia, and an increase in the number of axons with damage to the myelin sheath in the tissues of olfactory bulb and basal ganglia, changes in the ultrastructure of mitochondria of neurons in the tissues of olfactory bulb and basal ganglia of the brain, and differences in the mitochondrial profile of neurons in different regions of the rat brain. Our results collectively suggest that the central nervous system may be a target of low-level toxicity of lead oxide nanoparticles. © 2022, The Author(s).Ural Federal University Program of DevelopmentYekaterinburg Medical Research Center for Prophylaxis and Health Protection in Industrial WorkersMinistry of Education and Science of the Russian Federation, MinobrnaukaThe research funding from Yekaterinburg Medical Research Center for Prophylaxis and Health Protection in Industrial Workers for funding the experimental materials and facilities is gratefully acknowledged. The research funding from the Ministry of Science and Higher Education of the Russian Federation (Ural Federal University Program of Development within the Priority–2030 Program) for experiment implementation and analysis of its results is gratefully acknowledged

Features of the response to subchronic low-dose exposure to copper oxide nanoparticles in rats

Copper is an essential trace element for human health and, at the same time, a major industrial metal widely used both in its elemental form and in compounds. We conducted a dose-dependent assessment of the response of outbred albino male rats to subchronic low-dose exposure to copper oxide nanoparticles administered intraperitoneally at cumulative doses of 18 and 36 mg/kg during 6 weeks to exposure groups 1 and 2, respectively. We observed disorders at different levels of organization of the body in the exposed animals, from molecular to organismal. The observed decrease in the activity of succinate dehydrogenase in nucleated blood cells gave evidence of impaired bioenergetics processes. In view of the results of the metabolomics analysis, we assume mitochondrial damage and contribution of apoptotic processes to the pathology induced by copper poisoning. We also assume neurodegenerative effects based on the assessed morphological parameters of the nervous system, results of behavioral tests, and a decreased level of expression of genes encoding NMDA receptor subunits in the hippocampus. The hepatotoxic effect noted by a number of metabolomics-based, biochemical, and cytological indicators was manifested by the impaired protein-synthesizing function of the liver and enhanced degenerative processes in its cells. We also observed a nephrotoxic effect of nanosized copper oxide with a predominant lesion of proximal kidney tubules. At the same time, both doses tested demonstrated such positive health effects as a statistically significant decrease in the activity of alkaline phosphatase and the nucleated blood cell DNA fragmentation factor. Judging by the changes observed, the cumulative dose of copper oxide nanoparticles of 18 mg/kg body weight administered intraperitoneally approximates the threshold one for rats. The established markers of health impairments may serve as a starting point in the development of techniques of early diagnosis of copper poisoning. © 2023, The Author(s).Friedrich-Schiller-Universität Jena, FSU; Ministry of Education and Science of the Russian Federation, Minobrnauka; Ministry of Science and Higher Education of the Russian Federation: Priority – 2030Open Access funding enabled and organized by Projekt DEAL. The research funding from Yekaterinburg Medical Research Center for Prophylaxis and Health Protection in Industrial Workers for funding the experimental materials and facilities is gratefully acknowledged. The research funding from the Ministry of Science and Higher Education of the Russian Federation (Ural Federal University Program of Development within the Priority–2030 Program) for experiment implementation and analysis of its results is gratefully acknowledged. The authors would like to express their deepest gratitude to the staff of the Ural Center for Shared Use “Modern Nanotechnologies” of the Ural Federal University named after the First Russian President Boris Yeltsin and personally to Professor Vladimir Ya. Shur, Director of the Center, for invaluable support in conducting this study by synthesizing suspensions of the nanoparticles studied. We are also grateful to the staff of the Central Research Laboratory of the Ural State Medical University and personally to Professor Oleg G. Makeyev for establishing genomic DNA fragmentation

Low‐carbon transition risks for finance

The transition to a low‐carbon economy will entail a large‐scale structural change. Some industries will have to expand their relative economic weight, while other industries, especially those directly linked to fossil fuel production and consumption, will have to decline. Such a systemic shift may have major repercussions on the stability of financial systems, via abrupt asset revaluations, defaults on debt, and the creation of bubbles in rising industries. Studies on previous industrial transitions have shed light on the financial transition risks originating from rapidly rising “sunrise” industries. In contrast, a similar conceptual understanding of risks from declining “sunset” industries is currently lacking. We substantiate this claim with a critical review of the conceptual and historical literature, which also shows that most literature either examines structural change in the real economy, or risks to financial stability, but rarely both together. We contribute to filling this research gap by developing a consistent theoretical framework of the drivers, transmission channels, and impacts of the phase‐out of carbon‐intensive industries on the financial system and on the feedback from the financial system into the rest of the economy. We also review the state of play of policy aiming to protect the financial system from transition risks and spell out research implications