The present study demonstrates the possibility of fabricating zirconia parts with a complex shape and internal architecture using a low-cost stereolithography-based technique. One of the critical ...steps in ceramics stereolithography is the preparation of a photo-curable slurry with properties that fulfill specific requirements, such as having a low viscosity, high solids loading and appropriate curing characteristics. Slurries with different acrylic monomers and ceramic fillers were studied concerning their rheological and curing behavior. New formulations based on mono- and tri-functional acrylic monomers revealed the following excellent rheological properties: The viscosity of the mono-/tri-acrylate-based slurry with 75 wt.% of zirconia was 1.6 Pa·s at 30 s
. Zirconia stabilized with 3 mol.% yttria was found to be more favorable than zirconia with 8 mol.% yttria for slurry preparation, because of its lower surface area and higher tapped density. It was shown that the cure depth of the suspensions was suitable for printing objects with a 50 µm layer thickness, good interlayers connection and surface finishing.
To mitigate the potentially devastating effects of the COVID-19 pandemic, it is vital to identify psychosocial and moral resources. The care, preservation, protection, and well-being of social ...communities are attributes of prosocial behavior that can be such a resource. The purpose of the study is to identify the features of prosocial orientation of Russian youth during the COVID-19 pandemic, as well as to identify strategies for prosocial behavior during the COVID-19 pandemic. The sample consisted of 447 people. The study was conducted in May 2020 in the form of an online survey of subjects using Google Forms ("Moral Foundations Questionnaire method" and "Portrait Values Questionnaire"). The research made it possible to establish that Russians were dominated by norms of care, fairness, purity; values of benevolence-universalism, security, and self-direction. During the COVID-19 pandemic, the prosocial orientation of Russians may manifest itself in the following behavioral strategies: proactive prosocial strategy of "caring for others" (true altruism, expressed in forms of volunteering, helping a stranger, and charity despite the risk of contracting a coronavirus infection); egoistic strategy of prosocial behavior "self-care through caring for others" (volunteering based on self-development; helping a stranger to improve your own psychological well-being); conventional prosocial strategy "self-care" (self-isolation and preventive behavior). In the long run, it is necessary to identify personal and environmental resources that allowed people to effectively implement a prosocial self-isolation strategy during the COVID-19 pandemic, as well as various forms of volunteerism.
A new strategic direction for greening our cities and making them smart to reduce the environmental impact of their performance, increase employment and economic viability, and to enhance the quality ...of life requires a thorough assessment of sustainability and smart urban performance. This paper considers a database of over 90 global cities including London, New York, Hong Kong, San Francisco, Los Angeles, Sao Paolo, Rio de Janeiro, Buenos Aires, Paris, Berlin, Stockholm, Moscow, Beijing, Seoul, Singapore, Shanghai, Sydney and Tokyo exploring linkages between different sustainability and smart city dimensions. To assess urban sustainability performance, this study applied a multi‐criteria approach using a panel of 20 indicators to a set of 57 global cities. The assessment comprised important aspects of energy transitions, focusing on the drivers of CO2 emissions in cities, including the share of coal in the energy mix, public transport and cycling patterns, waste recycling, the water‐energy nexus, as well as the role of smart and creative economy. The results show that San Francisco leads in economic and environmental priorities, and Stockholm leads in social and smart city priorities. Seoul consistently performs very successfully across the whole spectrum of indicators. We devote considerable attention to the strategies, policies and performance of the leading cities, namely, San Francisco, Stockholm and Seoul. This assessment could be a valuable tool for policy‐makers and investors, and could help identify linkages between different sustainability dimensions, as well as investment opportunities in cities with sustainability potential.
The report analyzes and selects the liquefaction cycle for Liquid Air Energy Storage. The specific liquefaction coefficient and the coefficient of thermodynamic perfection were calculated for the ...following cycles: the Linde-Hampson cycle, the Claude cycle, the Heylandt Cycle, the Collins cycle, and the cycle with two expanders. The criterion for optimizing cycles is the maximum value of the liquefaction coefficient. The Claude cycle was chosen as the optimal cycle for use in the Liquid Air Energy Storage. Its exergy efficiency was calculated.
The variation-difference method is a convenient numerical method for shells of complex forms. It is enough when only cinematic boundary conditions are satisfied because the method is based on the ...principle of Lagrange. Another advantage of the variation-difference method is the better opportunity to create computer programs based on it. For shell analysis in orthogonal coordinate system as well as for shell analysis in principal curvatures the system of equations describing stress-strain state can be simplified. In this paper the difference between analysis in orthogonal coordinate system and analysis in principal curvatures of the surface is considered. The main distinction of the analysis of shells in orthogonal curvilinear coordinate system is the necessity of determination of components which include curvature of torsion of coordinate lines. The addition of these components in the equations of the theory of shells for the coordinate system in principal curvatures gives possibility to analyze shells in common orthogonal coordinate system. In this article shell analysis in orthogonal coordinate system is applied to shells based on normal cyclic surfaces.
This paper is focused on sustainability assessment for some of the most prominent global megacities: London, New York, Hong Kong, Los Angeles, Sao Paolo, Rio de Janeiro, Paris, Berlin, Moscow, ...Beijing, Singapore, Shanghai, Sydney and Tokyo. The alternative city rankings are compared and linkages between different sustainability and smart city dimensions are explored. The paper applied ELECTRE III multi-criteria decision aid tool to a panel of twenty indicators. The proposed approach allowed considering performance under four different policy priorities: environmental, economic, social and smart, changing the focus of the sustainability assessment. The results have shown that Singapore dominates the sustainability rankings under environmental policy priorities. Tokyo leads under economic and social priorities, and London and Tokyo – under smart city priorities. The worst performing cities were Shanghai, Los Angeles and Rio de Janeiro. The paper examines the innovative sustainability strategy and new governance structures that led Singapore to become the most sustainable city under environmental priorities and offers recommendations for the lower-ranking cities of Shanghai, Los Angeles and Rio de Janeiro. The assessment could be a valuable tool for policy makers and investors, and could help identify linkages between different sustainability dimensions, highlighting best practices as well as strategic opportunities in cities with sustainability potential.
•The article reviews analytical methods for urban sustainability assessment;•The interdisciplinary linkages among various sustainability dimensions are traced among 140+ cities with a special emphasis on megacities;•The multicriteria sustainability assessment is conducted for 14 global megacities under environmental, economic, social and smart priorities
Regeneration of the dura mater following duraplasty using a collagen film, a chitosan film, or a combination of both with gelatin, was studied in a craniotomy and penetrating brain injury model in ...rats. Collagen autofluorescence in the regenerated dura mater was evaluated using confocal microscopy with excitation at λem = 488 nm and λem = 543 nm. An increase in regeneration of the extracellular matrix of connective tissue and an increase in matrix fluorescence were detected at 6 weeks after duraplasty. The major contributors to dura mater regeneration were collagen films, chitosan plus gelatin-based films, and, to a much lesser extent, chitosan-based films. By using autofluorescence densitometry of extracellular matrix, the authors were able to quantify the degree of connective tissue regeneration in the dura mater following duraplasty.
PDF
