16 research outputs found
The impact of foreign language proficiency and language anxiety on overcoming the language barrier among first-year students of the Linguistics Department at Ural Federal University
No full textРабота посвящена выявлению влияния уровня владения иностранным языком и уровня языковой тревожности на преодоление языкового барьера. Объектом исследования является языковой барьер, предметом – установление корреляции между уровнем владения иностранным языком, языковой тревожностью и преодолением языкового барьера. Цель диссертационного исследования состоит в теоретическом и экспериментальном выявлении закономерностей влияния уровня владения иностранным языком и языковой тревожности на способность преодоления языкового барьера у студентов первого курса департамента лингвистики УрФУ через обращение к индивиду, т. е. в условиях психолингвистического эксперимента. Материалом для исследования послужили данные психолингвистического эксперимента, в котором приняли участие 30 обучающихся профильного языкового департамента Уральского федерального университета. Анализ результатов исследования показал прямую взаимосвязь между уровнем владения иностранным языком и языковой тревожностью среди студентов первого курса департамента лингвистики УрФУ. А именно, чем ниже уровень владения иностранным языком, тем выше уровень языковой тревожности. Помимо этого, в рамках проведенного эксперимента удалось доказать, что группа, обладающая более высокими навыками владения иностранным языком, более способна к преодолению языкового барьера.The study investigates the influence of foreign language proficiency and language anxiety on overcoming the language barrier. The object of the research is the language barrier. The subject of the study is the establishment of a correlation between foreign language proficiency, language anxiety, and overcoming the language barrier. The objective of the research is to theoretically and experimentally identify the patterns of influence of foreign language proficiency and language anxiety on the ability to overcome the language barrier among first-year students of the Linguistics Department at Ural Federal University by addressing the individual, that is, in the context of a psycholinguistic experiment. The research material consists of the data derived from a psycholinguistic experiment involving 30 students from the language department at Ural Federal University. The analysis of the research findings shows a direct correlation between foreign language proficiency and language anxiety among first-year students of the Linguistics Department at Ural Federal University. Specifically, the lower the level of foreign language proficiency, the higher the level of language anxiety. Additionally, the experiment demonstrates that the group with higher foreign language proficiency is more capable of overcoming the language barrier
Development of a polyurea-based composition with an extended life span
No full textObjectives. Improvement of the technology for obtaining polymer-sprayed coatings based on polycarbodiimides (polyureas) with high chemical, hydrolytic, and abrasive resistance and improved physical and mechanical properties, as well as obtainment of polyurea compositions with a lifetime of at least 5 min without loss performance characteristics (i.e., “hand-applied” polyureas) suitable for repair of coatings already in use.Methods. The reaction rate between isocyanate and amino groups is almost a hundred times higher than that between isocyanate and hydroxyl groups, necessitating the use of special highperformance and high-pressure installations equipped with self-cleaning mixing chambers and heating of components. The following are determined from the obtained materials: strength, elongation at break according to the standard method, Taber abrasion, and Shore hardness.Results. Three methods of slowing down the reaction are investigated: 1) the synthesis of prepolymers with the content of NCO groups from 10.5% to 18%; 2) the addition of a plasticizer into the prepolymer in the amount of 1–10 mass parts; and 3) the introduction of polyesters into the composition and radiation of the so-called “hybrid” systems. When using 14% polyesters with a molecular weight of 2000 Da, only “hybrid” systems make it possible to obtain compositions with a lifetime of more than 5 min. At the same time, the tensile strength decreases by 20%, and the abrasion increases by 40%; however, such “hybrid” systems have a higher adhesion force and are cheaper than pure polyureas, allowing them to be used as “repair” systems.Conclusions. The developed composition and technology of applying “hybrid” systems allow for the repair of existing coatings without using specialized devices. “Manual” polyurea is easy to use and does not require special training
МИКРОСПЕКТРАЛЬНОЕ РАМАНОВСКОЕ РАССЕЯНИЕ НА УПРУГИХ ДЕФОРМАЦИЯХ БАЛКИ КАНТИЛЕВЕРА
No full textFlexural elastic deformations of single-crystal silicon have been studied using microspectral Raman scattering. Results are reported on nano-scaled sign-changing shifts of the main peak of the microspectral Raman scattering within the single-crystal silicon cantilever beam during exposure to flexural stress. The maximum value of Raman shift characteristic of the silicon peak 518 cm-1 at which elasticity still remains, has been found to be 8 cm−1 which corresponds to an applied deformation of 4 GPa. We report three-dimensional maps of the distribution of internal stresses at different levels of deformation up to irreversible changes and brittle fracture of the samples that clearly show compression and tension areas and an undeformed area. A qualitative explanation of the increase in the strength of the cantilever beam due to its small thickness (2 μm) has been provided that agrees with the predictions of real-world physical parameters obtained in SolidWorks software environment with the SimulationXpress module. We have defined the relative strain of the beam surface which was 2% and received a confirmation of changes in the silicon lattice parameter from 5.4307Е to 5.3195Е by the BFGS algorithm
High-performance slow-curing polyurea compositions
No full textObjectives. To improve the technology for obtaining polymer spray coatings based on polycarbodiimides (polyureas) by studying changes in the process and operational parameters due to the introduction of aspartic acid derivatives (AADs) into the composition.Methods. The process of the production of sprayed and contact polyureas involves a number of difficulties, not least in terms of the cost of the components and high-pressure equipment. For this reason, mathematical modeling was used to optimize experimental design. The curing time of the composition was measured under conditions simulated to be close to actual. After thermostating and mixing Components A and B in predetermined ratios, the gelation time was measured to represent the curing time of the composition. The hardness of the material was determined by the Shore method according to GOST 24621-91. Tensile strength and relative elongation were determined according to a standard method (GOST 30436-96).Results. The effect of three AADs on the properties of the finished polyurea was studied. It was found that the introduction of two of them (AAD-1 and AAD-2) into polyurea in an amount of up to 40 wt % produces slow-curing (>250 s) polyureas capable of manual application. The finished products have physical properties on par with machine-poured materials (breaking strength >73 MPa; tensile strength >23 MPa; elongation >500%). Compiled regression equations were used to construct graphs of equal levels showing the possible areas of directed modification of the studied compositions.Conclusions. AAD can be used as a modifying component for polyurea systems to obtain slow-curing polyureas with high performance properties, which can be purposefully controlled by mathematical modeling. The resulting products have commercial value due to their combination of valuable physical and mechanical properties
ANALYSIS OF THE RESULTS OF EARLY ORTHODONTIC TREATMENT IN CHILDREN WITH CONGENITAL BILATERAL CLEFT LIP AND PALATE WITH A REMOVABLE ORTHODONTIC APPLIANCE
No full textThe article presents the results of early orthodontic treatment of children with congenital cleft lip and palate with a removable orthodontic appliance in primary dentition.</jats:p
Investigation of resonant phenomena in a locomotive wheelset on the basis of calculation of natural frequencies and modes of their oscillations on finite element models
No full textFrom the practice of engineering design it is known that in the development of mechanical systems, the operation of which is certainly not based on the phenomena of resonance, self-synchronization, etc., one should be wary of the proximity of the frequencies of free oscillations in such mechanical systems in different forms. Transient processes are dangerous due to the excitation of significant quantities of mechanical stresses and their damage to structures before destruction. This effect can also be appeared in wheel pairs (WS) of locomotives during operation. On the finite element model (FE) of the electric locomotive wheelset, calculations of natural frequencies and vibration modes are performed, the case of torsional oscillation frequencies with the participation of the electric drive gear and bending (saddle-shaped) oscillations of the running wheels is demonstrated, which can accelerate the processes of origin and development in its fatigue cracks. Paper discusses methodical issues of performing such calculations, problems of assessing the degree of danger of proximity of vibration frequencies of structural elements. The prototype of the finite-element model considered in the article was the WS of a locomotive with an asynchronous transmission, a one-way reducer and a composite retaining wheel. Methodical issues of performing such calculations, problems of assessing the degree of danger of proximity of vibration frequencies of structural elements are discussed. The results of calculations in combination with their visualization give a fairly complete idea of the behavior of the wheelset in the traction drive, while allowing studying the stress-strain state of its parts, and also providing an opportunity to identify the damaged elements and zones. It is highly advisable to carry out similar studies on virtual models when analyzing the operation of locomotive structures and assemblies under extreme operating conditions (for example, in case of boxing), which is not practicable or dangerous by experimental methods. It is possible, as shown, and it is necessary at the design stage of the WS to conduct its frequency analysis in the manner described in the article and, based on its results, perform a resonant detuning in a constructive or software way in the frequency range of the modulation of the operation of an asynchronous drive. To this end, by analogy with the AAR S-669 standard (USA), it is necessary to develop a domestic regulatory document for the projected locomotives with an asynchronous drive
Calculation and experimental evaluation of bogie frame and intermediate frame life of an eight-axle diesel locomotive
No full textIntroduction. Long-term locomotive operation and safety considerations require new approaches to extending the life of its basic components operating under variable loads.Materials and methods. The authors conducted bench life tests of frames under cyclic loading with vertical and horizontal transverse forces and calculated the bogie frame and intermediate frame life for the most stressed areas of their structures, where local fatigue damage can accumulate under cyclic loading leading to fatigue caused destruction. The calculation uses the results of bench fatigue tests.Results. The research shows that the presented frames comply with GOST R 55513–2013 in terms of minimum reserve strength coefficient for fatigue resistance. The researchers proposed a methodology for estimating the residual life of bogie frames and intermediate frames.Discussion and conclusion. The research indicates that the estimated safe service life of bogie frames and intermediate frames of an eight-axle diesel locomotive does not exceed 56 years from the date of construction. The expiry of this period allows for a repeat research and development work to determine the residual life of its basic parts. The above test methodology could be applied to assess the residual life of bogie frames and intermediate frames whose structure has localised zones of fatigue damage appearance and accumulation from cyclic loading, which may cause fatigue destruction
