Research of chromosilicated coatings on compact powder steels

Microstructures, chemical and phase compositions of diffusion chromosilicated coatings on powder steels 20, 45, У8 and У10 are investigated. The presence of Cr23C6 and Cr7C3 phases with up to 0,25 % Si is shown in these coatings. The distribution of diffusing chemical elements over the depth of the coating and at the interface with the matrix base is studied. Keywords: diffusion, coating, microstructure, chromosilication, powder steel, corrosion resistance [email protected]

Amplitude error correction in matrix simulators of radar targets

Problem statement. The compensation problem of the amplitude error occurring when modeling radar targets using matrix simulators is considered. The relations that reveal the concept of this error are given. The example shows that the amplitude of the simulated echo signal differs from the amplitude of the real one.Objective. Justification of a method for correcting the amplitude error observed when simulating echo signals from radar targets using emitter matrices.Results. It is shown that when the scanning radiation pattern is oriented normal to the matrix base, the amplitude of the simulated echo signal does not depend on the angular target position. Based on this, a method was proposed to eliminate the error through pre-distortion of the echo signal amplitude. The ratio for calculating the predistortion multiplier coefficient is obtained. In the framework of a numerical experiment, the amplitude of the simulated echo signal was estimated for various angular positions of the scanning radiation pattern without taking into account predistortion and with predistortion. The experimental results confirmed the correction effectiveness.Practical implications. The results obtained allow increasing the adequacy of modeling radar objects by matrix simulators by ensuring that the amplitude of the simulated echo signal corresponds to the amplitude of the real one.

Research into the Effect of Grain and the Content of Alundum on Tribological Properties and Selected Mechanical Properties of Polymer Composites

The subject of the research is a polymer composite with a matrix base of epoxy resin L285 cured with H285 hardener, and a physical modifier of friction in the form of alundum. The article presents an analysis of findings of tribological examinations. The authors evaluated the influence of the modifier properties in the form of alundum, i.e., mass share and grain size, on the abrasive wear of a composite, defined as loss of weight as well as on roughness parameters and selected mechanical properties. The tribological examinations have been extended by measurements of hardness and density of the prepared composites. The obtained results of tribological examinations showed an increase in the average value of weight loss in relation to the loss of sample weight loss between the cycles. The influence of both the grain size and the mass percentage share of alundum upon the increase in the longitudinal modulus of elasticity was also observed. On the basis of the obtained results, it was found that alundum of grain sizes equal to F220 and F240 exerted the best influence on the reduction of abrasive wear of the tested samples. In the case of F220, it was 14.04% of the average value of the weight loss between the cycles for all percentage shares of the used grains.

Explaining Code-Switching. Matrix Language Models vs. Bilingual Construction Grammar

This paper challenges the concept of matrix, base or basic language used in many descriptions and models of insertional code-switching. It proposes an account based on Construction Grammar and usage-based principles. At the heart of the paper is a discussion of four problematic issues of matrix-language approaches: the unitary conception of the notion of language, the generalization that syntactic frames mirror languages, the missing independent evidence for a matrix language and the narrow scope of the models that employ this term. The proposed approach of Bilingual Construction Grammar instead operates with a more complex, usage-based concept of language affiliation and places constructions in the centre of speech production. It thus avoids too coarse global predictions in favour of construction-specific predictions. This way, the matrix-language effect can be reinterpreted as by-product of constructional processing. Instead of using the term matrix language it is thus more appropriate to speak of matrix constructions.

Implementing the project for building professionally significant qualities of bachelors of economics

The research subject is building professionally significant qualities of Bachelors of Economics. The aim of the work is to show the possibilities of the project’s management in building professionally significant qualities of Bachelors of Economics. The novelty of the research is conditioned by rapid changes at today’s labor market within digital economy, which makes HEIs to respond actively through training highly marketable professionals. The article contains a description of the project aimed to solve the problem. The article presents the matrix of professionally significant qualities. The matrix base is made up of qualities-relations, individual and personal qualities, special abilities and qualities, social and personal qualities. The contents of these clusters correlate with soft skills, accumulating the requirements of digital economy, which is manifested in the articulation of critical thinking, teamwork skills, client focus, etc. On implementating the project, the goal was achieved by following a particular system mechanism – a hidden curriculum, that is a curriculum superstructure. To implement the project there were used technologies of portfolio and individual trajectory of the student’s professional development as mechanisms of control and self-control. Diagnostic tests proved the effectiveness of the project. Diagnostics revealed a great dynamics in professional skills and socially and individually significant abilities and qualities. As post-project activities, it is planned to dessiminate the practice for implementing bachelor’s programmes in Management, Human Resource Management, Trading, State and Municipal Management.

Creation of Oil-Filled Composites of Tribotechnical Purpose Based on Aromatic Polyamide Phenylone C-2

The authors of the paper suggested a recently developed technology of creating oil-filled composites based on aromatic polyamide Phenylone C-2. The depicted approach originates in the functional modification of the matrix base with nanomodified fillers and nanodimensional additives. The paper formulated the principles of absorption modification of mineral nanofiller for creating universal inhibitors of tribosystem or oleaginous polymer, more known as «maslyanit». It was demonstrated that the efficiency of polymer filling is enhanced by the joint application of the methods of preliminary solvent cleaning and dispersion of mineral particles to the nanodispersed state. The increase of the sorption capacity of natural and synthetic minerals was carried out by acid modification of minerals. A set of comparative tribological tests on a friction machine of Amsler II 5018 type according by a «finger-roller» scheme without external lubrication was carried out to evaluate the resistance of composite materials to abrasion at a constant specific pressure. It was found that the introduction of PFPE oil led to a significant decrease of the coefficient of friction practically in the entire loading range only in composites containing Aerosil. While the introduction of PMPS oil, in contrast, strengthened the antifriction effect of the samples, containing spinel and serpentine, in the load range of 209-720 N. The study of physical and mechanical properties of composites was carried out by NanoTest 600 complex. It was established that the samples with the addition of Arimid are characterized with the highest physical and mechanical properties. Besides, it as noted that the addition of PFPE and PMPS oils when creating oil-filled composites results in 20-25% decrease the microhardness and modulus of elasticity values. The carried out researches allowed concluding that the composite with that composition is most suitable for use in non-lubricated friction units.

MUNICÍPIO DE AMARANTE, ESTADO DO PIAUÍ: MAPEAMENTO E ANÁLISE DO USO ATUAL DA TERRA / MUNICIPALITY OF AMARANTE, STATE OF PIAUÍ: MAPPING AND ANALYSIS OF THE CURRENT LAND USE

As diversas formas de uso e ocupação do espaço geográfico têm provocado mudanças substanciais na paisagem, em detrimento ao desenvolvimento econômico. Neste sentido, o propósito desse estudo foi mapear e analisar os tipos de uso da terra existentes no município de Amarante, estado do Piauí. A área em análise está localizada na Microrregião do Médio Parnaíba piauiense, distando aproximadamente 160 km da capital Teresina, compreendendo uma área de 1.155,95 km². A pesquisa foi desenvolvida com base em técnicas de geoprocessamento e sensoriamento remoto. Para elaboração do mapa de uso e cobertura da terra foram utilizadas a imagem do satélite Landsat 8, sensor OLI, do ano de 2015. Após a aquisição da base matricial, as mesmas foram tratadas por meio de processamento digital de imagens, gerando o mapeamento de uso e cobertura da área. Foram mapeadas quatro tipologias em epígrafe, a saber: Área Antrópica Não-Agrícola (230,28 km²), Área Antrópica Agrícola (433,07 km²), Área de Vegetação Natural (441,86 km²) e Corpos D’água (50,73 km²). Diante deste mapeamento, constataram-se diferentes tipos de uso da terra, os quais acarretam modificações na paisagem. Desse modo, busca-se com essa pesquisa auxiliar as ações de gestão e planejamento por meio da análise dos tipos de uso da terra.Abstract:The different forms of use and occupation of geographical space have caused substantial changes in landscape, to the detriment of economic development. In this sense, the purpose of this study was to map and analyze the types of land use existing in the municipality of Amarante, state of Piauí. The area in analysis is located in the Microregion of Middle Parnaíba Piauiense, distant approximately 160 km from the capital Teresina, comprising an area of 1.155,95 km². The research was developed based on geoprocessing and remote sensing techniques. For the elaboration of land use/cover map was used the satellite Landsat 8, OLI sensor, of the year 2015. After the acquisition of the matrix base, this was treated by digital image processing, generating the mapping of land use/cover of the area. Four types were mapped: Anthropic Non-Agricultural Area (230,28 km²); Anthropic Agricultural Area (433,07 km²); Natural Vegetation Area (441,86 km²) and Waterbodies (50,73 km²). In view of this mapping, different types of land use were verified, which lead to changes in the landscape. Thus, we seek with this research support the actions of management and planning through analysis of the types of land use.Keywords: Geoprocessing; Geographic Space; Parnaíba River.

Effective Porosity Comparison with a Lime Mortar Matrix Base during 350 to 700 Days

This research is an investigation about the use of powder material additions with mortars lime base for a possible implementation in construction and/or restoration of historical sites. Mortars were elaborated in laboratory conditions with a 1:2.5 in weight proportion. One of the proofs to which these mortars were submitted was the test of capillary absorption; this way, the influence of the materials added to powder in these mortars determined porosity. Mortars were made with different percentages of materials. These powder materials are brick manufacturing ash, quarry powder, clay and maize starch. The test was run during 350 to 700 days. It obtained better results with 700 days than with 350 days.