Grain boundary oxide layers in NdFeB-based permanent magnets

The microstructure of grain boundaries (GBs) in the commercial NdFeB-based alloy for permanent magnets has been studied. It is generally accepted that the unique hard magnetic properties of such alloys are controlled by the thin layers of a Nd-rich phase in Nd$_{2}$Fe$_{14}$B/Nd$_{2}$Fe$_{14}$B GBs. These GB layers ensure the magnetic isolation of Nd$_{2}$Fe$_{14}$B grains from each other. It is usually supposed that such GB layers contain metallic Nd or Nd-rich intermetallic compounds. However, the commercial NdFeB-based permanent magnets frequently contain a tangible amount of neodymium oxide Nd$_{2}$O$_{3}$ at the triple junctions between Nd$_{2}$Fe$_{14}$B grains. The goal of this work was to check whether the Nd$_{2}$Fe$_{14}$B/Nd$_{2}$Fe$_{14}$B GBs could also contain the thin layers of Nd$_{2}$O$_{3}$ oxide phase. Indeed, the screening with EELS-based elemental analysis permitted to observe that some of these Nd-rich layers in Nd$_{2}$Fe$_{14}$B/Nd$_{2}$Fe$_{14}$B GBs contain not only neodymium, but also oxygen. More detailed analysis of such GBs with high-resolution transmission electron microscopy (HR TEM) showed these GB layers are crystalline and have the lattice of neodymium oxide Nd$_{2}$O$_{3}$. In turn, the Lorentz micro-magnetic contrast in TEM permitted to observe that the Nd-oxide GB layers prevent the migration of domain walls from one Nd$_{2}$Fe$_{14}$B grain to another during remagnetization. This finding proves that the GB oxide layers, similar to those of metallic Nd or Nd-rich intermetallic compounds, can ensure the magnetic isolation between Nd$_{2}$Fe$_{14}$B grains needed for high coercivity. Therefore, the GB oxide layers can be used for further development of NdFeB-based permanent magnets

Carácter económico de la competencia: enfoques metodológicos generales del problema

In the period of structural and qualitative changes in the Russian economy, the development of the labor market and the educational services market, the effectiveness of economic education is largely determined by the level of formation of economic competencies of students. The development of the diversification process required bringing the education system in line with the requirements of market relations, the principles of alternatives and variability, ensuring the quality of education, which is the most important condition for the specialist’s demand in the labor market. The target component of the model of formation of students’ economic competences by definition includes the goals and objectives of economic training. The increased demand for economic knowledge has led to new forms of economic education. The activity component in the model of formation of economic competencies focuses on the fact that in the domestic system of education in relation to the vocational school there was a long-term practice of compiling the qualification characteristics of a specialist, which fixed the requirements for knowledge, skills and abilities of graduates of various specialties, where in addition to the knowledge paradigm there were the terms “readiness”, “ability”, “responsibility”, “understanding” and “worldview”, expanding the close framework of such a paradigm. The main idea of the activity approach in education is not connected with the activity itself, but with the activity as a means of formation and development of the student’s personality. The content component of the model involves the formation of students’ economic competencies in the form of key, professional and additional economic competencies at different levels of professional education, taking into account training in economic and non-economic specialties.En el período de cambios estructurales y cualitativos en la economía rusa, el desarrollo del mercado laboral y el mercado de servicios educativos, la efectividad de la educación económica está determinada en gran medida por el nivel de formación de competencias económicas de los estudiantes. El desarrollo del proceso de diversificación requirió alinear el sistema educativo con los requisitos de las relaciones de mercado, los principios de alternativas y variabilidad, asegurando la calidad de la educación, que es la condición más importante para la demanda del especialista en el mercado laboral. El componente objetivo del modelo de formación de las competencias económicas de los estudiantes, por definición, incluye las metas y objetivos de la formación económica. La mayor demanda de conocimiento económico ha llevado a nuevas formas de educación económica. El componente de actividad en el modelo de formación de competencias económicas se centra en el hecho de que en el sistema educativo interno en relación con la escuela vocacional había una práctica a largo plazo de recopilar las características de calificación de un especialista, que fijaba los requisitos de conocimiento, habilidades y destrezas de graduados de diversas especialidades, donde además del paradigma del conocimiento existían los términos “preparación”, “habilidad”, “responsabilidad”, “comprensión” y “visión del mundo”, ampliando el marco cercano de tal paradigma. La idea principal del enfoque de la actividad en la educación no está relacionada con la actividad en sí, sino con la actividad como un medio de formación y desarrollo de la personalidad del alumno. El componente de contenido del modelo implica la formación de competencias económicas de los estudiantes en forma de competencias económicas clave, profesionales y adicionales en diferentes niveles de educación profesional, teniendo en cuenta la capacitación en especialidades económicas y no económicas

Hygienic characteristics of the rehabilitation instructors’ working conditions and the patients’ stay conditions in the Ural kinesiotherapy center

The purpose of the study is to carry out an assessment of the working conditions of a rehabilitation instructor in the workplace.Цель исследования – провести оценку условий труда инструктора – реабилитолога на рабочем месте

Comparative assessment of the daily routine of students of medical and technical universities

The purpose of the study is to conduct a comparative assessment of the life regime of students of medical and technical universities.Цель исследования – провести сравнительную оценку режима жизнедеятельности студентов медицинского и технического университетов

Examining the level of tolerance of students of Ural state medical university

This article shows the results of examining the level of tolerance of the USMU students. The overall level of tolerance has been evaluated and also its certain aspects have been analyzed, such as ethnic tolerance, social tolerance, tolerance as a personality trait.В статье представлены результаты исследования уровня толерантности студентов УГМУ. Оценивался общий уровень толерантности, а так же был проведен анализ отдельных ее аспектов, таких как: этническая толерантность, социальная толерантность, толерантность, как черта личности

Fundamentals of interface phenomena in advanced bulk nanoscale materials

The review is devoted to a study of interface phenomena influencing advanced properties of nanoscale materials processed by means of severe plastic deformation, high-energy ball milling and their combinations. Interface phenomena include processes of interface defect structure relaxation from a highly nonequilibrium state to an equilibrium condition, grain boundary phase transformations and enhanced grain boundary and triple junction diffusivity. On the basis of an experimental investigation, a theoretical description of the key interfacial phenomena controlling the functional properties of advanced bulk nanoscale materials has been conducted. An interface defect structure investigation has been performed by TEM, high-resolution x-ray diffraction, atomic simulation and modeling. The problem of a transition from highly non-equilibrium state to an equilibrium one, which seems to be responsible for low thermostability of nanoscale materials, was studied. Also enhanced grain boundary diffusivity is addressed. Structure recovery and dislocation emission from grain boundaries in nanocrystalline materials have been investigated by analytical methods and modeling

Superior strength of carbon steel with an ultrafine-grained microstructure and its enhanced thermal stability

© 2015, Springer Science+Business Media New York. The paper presents the results of a study on the microstructure and mechanical properties of a medium-carbon steel (0.45 % C) processed by severe plastic deformation (SPD) via high-pressure torsion (HPT). Martensite quenching was first applied to the material, and then HPT processing was conducted at a temperature of 350 °C. As a result, a nanocomposite type microstructure is formed: an ultrafine-grained (UFG) ferrite matrix with fine cementite particles located predominantly at the boundaries of ferrite grains. The processed steel is characterized by a high-strength state, with an ultimate tensile strength over 2500 MPa. Special attention is given to analysis of the thermal stability of the microstructure and properties of the steel after HPT processing in comparison with quenching. It is shown that the thermal stability of the UFG structure produced by HPT is visibly higher than that of quenching-induced martensite. The origin of the enhanced strength and thermal stability of the UFG steel is discussed

Estimation of the mineral composition of buckwheat depending on the region of growing and the method of grain processing

The article presents the results of laboratory studies of the mineral composition of buckwheat for calcium, magnesium, iron and phosphorus. Analysis of dependence of contained mineral elements on the region of growing and the method of grain processing was carried out. Also, the percent of satisfying daily requirement for minerals by consumption of 100 g of buckwheat was stated.В статье представлены результаты лабораторного исследования минерального состава гречневой крупы по следующим показателям: кальций, магний железо и фосфор. Была проанализирована зависимость содержания основных микроэлементов от региона произрастания и способа обработки зерна. Также был установлен процент удовлетворения суточной потребности человека в минеральных веществах за счет потребления 100 грамм гречневой крупы

Neurodevelopmental Syndrome with Intellectual Disability, Speech Impairment, and Quadrupedia Is Associated with Glutamate Receptor Delta 2 Gene Defect

Bipedalism, speech, and intellect are the most prominent traits that emerged in the evolution of; Homo sapiens; . Here, we describe a novel genetic cause of an "involution" phenotype in four patients, who are characterized by quadrupedal locomotion, intellectual impairment, the absence of speech, small stature, and hirsutism, observed in a consanguineous Brazilian family. Using whole-genome sequencing analysis and homozygous genetic mapping, we identified genes bearing homozygous genetic variants and found a homozygous 36.2 kb deletion in the gene of glutamate receptor delta 2 (; GRID2; ) in the patients, resulting in the lack of a coding region from the fifth to the seventh exons. The; GRID2; gene is highly expressed in the cerebellum cortex from prenatal development to adulthood, specifically in Purkinje neurons. Deletion in this gene leads to the loss of the alpha chain in the extracellular amino-terminal protein domain (ATD), essential in protein folding and transport from the endoplasmic reticulum (ER) to the cell surface. Then, we studied the evolutionary trajectories of the; GRID2; gene. There was no sign of strong selection of the highly conservative; GRID2; gene in ancient hominids (Neanderthals and Denisovans) or modern humans; however, according to in silico tests using the Mfold tool, the; GRID; 2 gene possibly gained human-specific mutations that increased the stability of; GRID2; mRNA