Research of Magnetic Field Distribution in the Working Area of Disk Separator, Taking Into Account an Influence of Materials of Permanent Magnets

Based on the results of a numerical-field analysis of the distribution of the magnetic force field in the working area of the disk magnetic separator, designed to clean bulk substances from ferromagnetic inclusions, the influence of the magnetic material of the poles of the magnetic system on the field distribution is determined. A consistent study of two magnetic systems assembled on the basis of magnetic materials of different classes is carried out. The finite element method implemented in the COMSOL Multiphysics software environment is used to calculate the distribution of magnetic induction in a disk magnetic separator with rare-earth and ferrite magnets. Due to the complexity of the spatial geometry of the force field in the working area of the disk magnetic separator, a three-dimensional model of the magnetic system is developed. A comparative analysis of the distribution of the magnetic force field in the working area of the disk separator with a highly coercive magnetic system and with a magnetic system based on ferrite blocks is carried out. As a result of the analysis, it is found that the indicators of the intensity and heterogeneity of the magnetic field for a highly coercive magnetic system significantly exceed the corresponding parameters of a ferrite magnetic system. It is proved that when choosing magnets for the magnetic system of a disk separator, preference should be given to highly coercive alloys, the magnetic properties of which significantly exceed the magnetic properties of ferrite magnets. To reduce the cost of the magnetic system of the disk separator, the use of a combined magnetic system assembled from magnetic materials of different classes is proposed. Studies of combined magnetic systems with various mass fractions of magnetic materials are done. The ratio of the mass fractions of magnets of various properties in the poles of the magnetic system is determined, at which sufficiently high magnetic characteristics are provided in the working area. It is shown that the presence of a ferrite fraction in the magnetic poles not only reduces the cost of the magnetic system of the separator, but also reduces the mass of the system. The tasks of further research are justifie

Do retail coffee prices increase faster than they fall? Asymmetric price transmission in France, Germany and the United States

This investigation examines price transmission asymmetries (PTA) between international and retail coffee prices in the US, France and Germany. Differences in price transmission mechanisms provide evidence for disparities in market structure and market performance across countries. Although all processors of roasted coffee purchase green coffee at the same price in the international markets, one finds significant differences in retail prices among these countries. The study develops an Error Correction (EC) representation model to assess PTA of non-stationary models. Finally, it claims that identifying differences in price transmission asymmetry is an approach to compare market structure across countries.coffee, markets, Food Consumption/Nutrition/Food Safety, Marketing,

The Neuroscience of Moral Judgment: Empirical and Philosophical Developments

We chart how neuroscience and philosophy have together advanced our understanding of moral judgment with implications for when it goes well or poorly. The field initially focused on brain areas associated with reason versus emotion in the moral evaluations of sacrificial dilemmas. But new threads of research have studied a wider range of moral evaluations and how they relate to models of brain development and learning. By weaving these threads together, we are developing a better understanding of the neurobiology of moral judgment in adulthood and to some extent in childhood and adolescence. Combined with rigorous evidence from psychology and careful philosophical analysis, neuroscientific evidence can even help shed light on the extent of moral knowledge and on ways to promote healthy moral development

Ac Josephson Effect in Topological Josephson Junctions

Topological superconductors admit zero-energy Majorana bound states at their boundaries. In this review article, we discuss how to probe these Majorana bound states in Josephson junctions between two topological superconductors. In the absence of an applied bias, the presence of these states gives rise to an Andreev bound state whose energy varies $4\pi$-periodically in the superconducting phase difference. An applied voltage bias leads to a dynamically varying phase according to the Josephson relation. Furthermore, it leads to dynamics of the occupation of the bound state via its non-adiabatic coupling to the continuum. While the Josephson relation suggests a fractional Josephson effect due to the $4\pi$-periodicity of the bound state, its observability relies on the conservation of the occupation of the bound state on the experimentally probed time scale. We study the lifetime of the bound state and identify the time scales it has to be compared to. In particular, we are interested in signatures of the fractional Josephson effect in the Shapiro steps and in current noise measurements. We also discuss manifestations of the zero-energy Majorana states on the dissipative subgap current.Comment: 19 pages, 12 figure

A solution NMR approach to determine the chemical structures of carbohydrates using the hydroxyl groups as starting points

An efficient NMR approach is described for determining the chemical structures of the monosaccharide glucose and four disaccharides, namely, nigerose, gentiobiose, leucrose and isomaltulose. This approach uses the 1H resonances of the −OH groups, which are observable in the NMR spectrum of a supercooled aqueous solution, as the starting point for further analysis. The 2D-NMR technique, HSQC-TOCSY, is then applied to fully define the covalent structure (i.e., the topological relationship between C–C, C–H, and O–H bonds) that must be established for a novel carbohydrate before proceeding to further conformational studies. This process also leads to complete assignment of all 1H and 13C resonances. The approach is exemplified by analyzing the monosaccharide glucose, which is treated as if it were an “unknown”, and also by fully assigning all the NMR resonances for the four disaccharides that contain glucose. It is proposed that this technique should be equally applicable to the determination of chemical structures for larger carbohydrates of unknown composition, including those that are only available in limited quantities from biological studies. The advantages of commencing the structure elucidation of a carbohydrate at the −OH groups are discussed with reference to the now well-established 2D-/3D-NMR strategy for investigation of peptides/proteins, which employs the −NH resonances as the starting point

Establishment Wage Differentials

Economists have long known that individual wages depend on a combination of employee and employer characteristics, as well as the interaction of the two. Although it is important to understand how employee and employer characteristics are related to wages, little is known about the magnitude and relation of these wage effects. This is primarily due to the lack of microdata which links individuals to the establishments where they work, but also due to technical difficulties associated with separating out employee and employer effects. This paper uses data from the Occupational Employment Statistics program at the Bureau of Labor Statistics that permit both of these issues to be addressed. Our results show that employer effects contribute substantially to earnings differences across individuals. We also find that establishments that pay well for one occupation also pay well for others. This paper contributes to the growing literature that analyzes firms’ compensation policies, and specifically the topic of employer effects on wages.Establishment Wage Differentials; Occupational Employment Statistics