96 research outputs found
The analytical solution of 2D electromagnetic wave equation for eddy currents in the cylindrical solid rotor structures
The paper presents the closed-form solution of two dimensional (2D) electromagnetic wave equation for eddy current problems in cylindrical structures. The magnetic field calculation is a complex issue for electrical machines especially. The paper provides an analytical solution for solid cylindrical structures with linear magnetization. This approach is extended to the electrical machines with the solid rotors. Multilayered cylindrical geometry is used for the solution. Two dimensional parabolic partial differential equation is solved for each layer. According to the analytical solution, eddy current and eddy current losses are calculated in the solid region and compared to the results of the finite element model
Assessment of the genotoxic impact of pesticides on farming communities in the countryside of Santa Catarina State, Brazil
The aim of this study was to assess the use of pesticides on farms located in the Lambedor River watershed in Guatambu, State of Santa Catarina, as well as to determine, by micronucleus testing, the risk of genotoxic impact. Samples from locally collected Cyprinus carpio, Hypostomus punctatus, Rhamdia quelen and Oreochromis niloticus gave evidence of a mean increase in micronuclei frequency from 6.21 to 13.78 in 1,000 erythrocytes, a clear indication of the genotoxic potenciality of pesticide residues in regional dams, and their significant contribution to local environmental contamination
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Theoretical perspectives on organizations and organizing in a post-growth era
The fundamental assumption we base this Special Issue on is that narrow concepts of growth have become the ruling ideas of this age, entrenched both in everyday life and to a considerable extent in the theoretical thinking and traditions of research conducted by organization and management studies scholars. We explain how tacit (or overt) endorsement of unbridled economic growth (the growth imperative) has pernicious practical effects and how it tends to restrict the intellectual base of the field. We argue that notions of degrowth present scholars with challenges as well as opportunities to reframe core assumptions and develop new directions in theory and research. Envisioning a post-COVID 19 world where societies and organizations can flourish without growth is one of the most difficult tasks facing theorists. We approach this challenge first by discussing the hegemonic properties of growth ideology and second by sketching an alternative political economy as a context for reimagining social and economic relations within planetary capacities in a post-growth era. Drawing on degrowth literature in ecological economics, sociology and political ecology, we identify key principles relevant to processes of organizing for a more just and environmentally sustainable future: frugal abundance, conviviality, care, and open relocalization. We conclude by introducing the three articles we feature in this issue along with some thoughts about theorizing policy and regulatory changes needed to generate transformational change and a future research agenda
Organizing in the Anthropocene
The functioning of the biosphere and the Earth as a whole is being radically disrupted due to human activities, evident in climate change, toxic pollution and mass species extinction. Financialization and exponential growth in production, consumption and population now threaten our planet’s life-support systems. These profound changes have led Earth System scientists to argue we have now entered a new geological epoch – the Anthropocene. In this introductory article to the Special Issue, we first set out the origins of the Anthropocene and some of the key debates around this concept within the physical and social sciences. We then explore five key organizing narratives that inform current economic, technological, political and cultural understandings of the Anthropocene and link these to the contributions in this Special Issue. We argue that the Anthropocene is the crucial issue for organizational scholars to engage with in order to not only understand on-going anthropogenic problems but also help create alternative forms of organizing based on realistic Earth–human relations
Prediction of school dropout among turkish high school students: A model testing with moderator and mediator variables [Türk lise ögrencilerinde okul terkinin yordanmasi: Araci ve etkileşim degiskenleri ile bir model testi]
In this study, firstly, it is inquired whether disciplinary punishment, antisocial behaviors and alcohol and cigarette use mediate the relationship between school dropout and impulsivity. Secondly, it is examined whether the teacher support moderates between antisocial behaviors on school dropout risk. Participants were 478 students attending the public high schools in Ankara in 2009-2010. The results show that family and friend support reduce school dropout risk, but impulsivity increases it. Besides, disciplinary punishment, use, and antisocial behaviors mediate the relationship between impulsivity and school dropout risk. Teacher support moderates the relationship between antisocial behaviors and school dropout risk. The sex and achievement level of the students did not significantly predict school dropout risk
Covalent immobilization of invertase on microporous pHEMA-GMA membrane
Kacar, Yasemin/0000-0002-8682-9228WOS: 000188543800018Poly (2-hydroxyethyl methacrylate-glycidyl methacrylate) (pHEMA-GMA) membrane was prepared by UV-initiated photopolymerization. Invertase was immobilized by the condensation reaction of the epoxy groups of glycidyl methacrylate in the membrane structure with amino groups of the enzyme. The (Km) values were 22 mM and 58 mM for free and immobilized enzyme, respectively. Immobilization improved the pH stability and temperature stability of the enzyme. Thermal stability was found to increase with immobilization. The half times for the activity decay at 70 degreesC were found to be 11 and 38 min for the free and immobilized enzyme, respectively. The immobilized enzyme activity was found to be quite stable in later experiments. (C) 2003 Elsevier Ltd. All rights reserved
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