Multiphysical computations of the electrical machines using FEM

In this paper three problems representing the multiphysical aspect of electrical machine computation are addressed. The interaction between magnetic and structural mechanical systems is demonstrated by the finite element method (FEM) structural investigation of the turbo-generator end-winding deformations. Multiphysical simulation of the acoustical problem is presented by weakly coupled electromagnetic, structural dynamic and acoustic simulations. And finally, a procedure based on computational fluid dynamics (CFD) simulation for acquiring the convective heat transfer coefficients is proposed in order to improve the accuracy of the coupled electro-thermal FEM simulations

The cultural and geopolitical dimensions of nation-building in the Ukraine

Ukraine belongs among those young countries where the beginnings of democratisation and nation-building approximately coincided. While the development of nation states in Central Europe was usually preceded by the development of nations, the biggest dilemma in the Ukraine is whether a nation-state programme — parallel to the aim of state-building — is able to bring unfinished nation-building to completion. Ukraine sways between the EU and Russia with enormous amplitude. The alternating orientation between the West and the East can be ascribed to superpower ambitions reaching beyond Ukraine. Eventually, internal and external determinants are intertwined and mutually interact with one another. The aim of the paper is to explain the dilemmas arising from identity problems behind the Ukraine’s internal and external orientation

Constraining the properties of delta Scuti stars using spectroscopic eclipsing binary systems

Many stars exhibit stellar pulsations, favoring them for asteroseismic analyses. Interpreting the oscillations requires some knowledge of the oscillation mode geometry (spherical degree, radial and azimuthal orders). The delta Scuti stars (1.5 - 2.5 M_sol) often show just one or few pulsation frequencies. Although this may promise a successful seismological analysis, we may not know enough about either the mode or the star to use the oscillation frequency to improve the determination of the stellar model, or probe the star's structure. For the observed frequencies to be used successfully as seismic probes of these objects, we need to concentrate on stars for which we can reduce the number of free parameters in the problem, such as binary systems or open clusters. We investigate how much our understanding of a delta Scuti star is improved when it is in a detached eclipsing binary system instead of being a single field star. We use singular value decomposition to explore the precision we expect in stellar parameters (mass, age and chemical composition) for both cases. We examine how the parameter uncertainties propagate to the luminosity - effective temperature diagram and determine when the effort of obtaining a new measurement is justified. We show that for the single star, a correct identification of the oscillation mode is necessary to produce strong constraints on the stellar model properties, while for the binary system the observations without the pulsation mode provide the same or better constraints on the stellar parameters. In the latter case, ...Comment: emulateapj 16 pages, accepted Ap

Systems of Differential Algebraic Equations in Computational Electromagnetics

Starting from space-discretisation of Maxwell's equations, various classical formulations are proposed for the simulation of electromagnetic fields. They differ in the phenomena considered as well as in the variables chosen for discretisation. This contribution presents a literature survey of the most common approximations and formulations with a focus on their structural properties. The differential-algebraic character is discussed and quantified by the differential index concept

Ancient genomic time transect from the Central Asian Steppe unravels the history of the Scythians

The Scythians were a multitude of horse-warrior nomad cultures dwelling in the Eurasian steppe during the first millennium BCE. Because of the lack of first-hand written records, little is known about the origins and relations among the different cultures. To address these questions, we produced genome-wide data for 111 ancient individuals retrieved from 39 archaeological sites from the first millennia BCE and CE across the Central Asian Steppe. We uncovered major admixture events in the Late Bronze Age forming the genetic substratum for two main Iron Age gene-pools emerging around the Altai and the Urals respectively. Their demise was mirrored by new genetic turnovers, linked to the spread of the eastern nomad empires in the first centuries CE. Compared to the high genetic heterogeneity of the past, the homogenization of the present-day Kazakhs gene pool is notable, likely a result of 400 years of strict exogamous social rules.Introduction Results - The IA transition in the Kazakh Steppe - Admixture modeling of IA steppe populations - Post-IA genetic turnovers in the Kazakh Steppe - Dating ancient admixture - Present-day Kazakhs Discussion Material and methods - Radiocarbon dating - DNA extraction, library preparations, and sequencing - Modern DNA genotyping and quality controls - Ancient DNA data processing -- Raw data -- Authentication and contamination estimate -- Genotyping -- Sex determination -- Genetic relatedness estimation - Uniparental haplogroup assignment - Population structure analyses - Individual labeling and population grouping criteria - F-statistics and ancestry modeling - Admixture dating - CHROMOPAINTER and fineSTRUCTURE analyse

Impact of Dreissena fouling on the physiological condition of native and invasive bivalves : interspecific and temporal variations

The impact of Dreissena fouling on unionids has hardly been studied in Europe, despite the fact that in some ecosystems (e.g. Lake Balaton, Hungary) infestations of several hundreds to a thousand individuals per unionid have been observed. At present, the zebra mussel Dreissena polymorpha is a dominant species in Lake Balaton and in the last decade three other invasive bivalves were introduced, potentially increasing the pressure on native unionid survival. We examined whether the fouling of dreissenids (zebra and quagga (D. rostriformis bugensis) mussels) has a negative impact on native (Anodonta anatina, Unio pictorum and U. tumidus) and invasive (Corbicula fluminea and Sinanodonta woodiana) bivalves and whether there are any interspecific and temporal variations in fouling intensity and physiological condition measured by standard condition index and glycogen content. A significant negative impact was detected on native unionids only in July and September (no impact was detected in May), when the fouling rate was high. For invasive species, a significant negative impact was detected on S. woodiana with a high level of dressenid infestation; whereas no significant impact was detected on C. fluminea. Overall, this study confirms that Dreissena may threaten unionid species including the invasive S. woodiana, although high interspecific and temporal variations were observed. This situation should be taken into account in future ecological and conservational assessments because species respond differently to Dreissena fouling and effects seem to be more pronounced in late summer/early autumn. In addition, this study provides the first evidence that the invasive C. fluminea appear to be less vulnerable to dressenid fouling.The study was supported by the Hungarian Scientific Fund (KTIA-OTKA) under the contract No. CNK80140

Feel4Diabetes healthy diet score: Development and evaluation of clinical validity

Background: The aim of this paper is to present the development of the Feel4Diabetes Healthy Diet Score and to evaluate its clinical validity. Methods: Study population consisted of 3268 adults (63% women) from high diabetes risk families living in 6 European countries. Participants filled in questionnaires at baseline and after 1 year, reflecting the dietary goals of the Feel4Diabetes intervention. Based on these questions the Healthy Diet Score was constructed, consisting of the following components: breakfast, vegetables, fruit and berries, sugary drinks, whole-grain cereals, nuts and seeds, low-fat dairy products, oils and fats, red meat, sweet snacks, salty snacks, and family meals. Maximum score for each component was set based on its estimated relative importance regarding T2DM risk, higher score indicating better quality of diet. Clinical measurements included height, weight, waist circumference, heart rate, blood pressure, and fasting blood sampling, with analyses of glucose, total cholesterol, HDL-cholesterol, LDL-cholesterol, and triglycerides. Analysis of (co) variance was used to compare the Healthy Diet Score and its components between countries and sexes using baseline data, and to test differences in clinical characteristics between score categories, adjusted for age, sex and country. Pearson''s correlations were used to study the association between changes from baseline to year 1 in the Healthy Diet Score and clinical markers. To estimate reproducibility, Pearson''s correlations were studied between baseline and 1 year score, within the control group only. Results: The mean total score was 52.8 ± 12.8 among women and 46.6 ± 12.8 among men (p < 0.001). The total score and its components differed between countries. The change in the Healthy Diet Score was significantly correlated with changes in BMI, waist circumference, and total and LDL cholesterol. The Healthy Diet Score as well as its components at baseline were significantly correlated with the values at year 1, in the control group participants. Conclusion: The Feel4Diabetes Healthy Diet Score is a reproducible method to capture the dietary information collected with the Feel4Diabetes questionnaire and measure the level of and changes in the adherence to the dietary goals of the intervention. It gives a simple parameter that associates with clinical risk factors in a meaningful manner