6 research outputs found
THE INFLUENCE OF CHEMICAL COMPOSITION OF HIGH-CHROMIUM CAST IRONS ON THE MACHINABILITY
No full textPurpose. This research is aimed to obtain the regression dependence of the machinability on the chemical composition of pig iron (C, Cr, Mn and Ni) in cast state. Methodology. The method of active experiment planning was used to build a mathematical model. Cast irons of composition 1.09…3.91 % С; 11.43…25.57 % Cr; 0.6…5.4 % Mn; 0.19…3.01 % Ni were studied. Cutting tools with plates 10х10 mm out of ВК8 according to State Standard 19051-80 were used for turning. Cutting modes: cutting depth – 0.8 mm, longitudinal feed – 0.15 mm/rot., spindle’s rotation frequency during turning – 200…360 rot./min. Lubricating and cooling liquids were not applied. Evaluation of iron workability was produced by determining the linear tool flank wear per unit length of the cutting path. Findings. Mathematically probabilistic equation of the regression dependence of the cutting tool’s wear on the C, Cr, Mn and Ni content in the machined cast iron were obtained. It was established that with the increase of Cr content in the cast iron to 14.8 % the cutting tool’s wear decreased as a result of formation of carbide eutectic which destroyed the doped ledeburite continuous frame. Further increase of chromium content promoted appearing of chromic carbides with high microhardness which considerably increased the tool’s wear. The conducted research shown that the minimum cutting tool’s wear 0,18 mkm/m was observed during the machining of cast iron containing: 1.09 % C, 14.8 % Cr, 2.3 % Mn and 1.2 % Ni; and the maximum wear is 48,96 mkm/m – when the content was: 3.91 % C, 11.43 % Cr, 5.4 % Mn and 0.19 % Ni. The tool’s wear reached 47.61 mkm/m during the treatment of cast iron containing 3.91 % C, 25.57 % Cr, 5.4 % Mn and 0.19 % Ni. Originality. Mathematically probabilistic model of the dependence of the cutting tool’s wear on the C, Cr, Mn and Ni content in the machined cast iron has been elaborated by the author. Practical value. The model allows optimizing the compositions of wear-resistant cast irons for castings which require the significant mechanical machining. Cast irons compositions were recommended for different exploitation conditions
Morte, música e sexualidade na Ópera Turandot de Puccini
No full textDissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Comunicação e Expressão. Programa de Pós-Graduação em Literatura.Esta dissertação pretende ser uma análise multiangular da ópera Turandot, de Giacomo Puccini (1858-1924). Deixada incompleta pelo compositor e encenada pela primeira vez em 1926, esta ópera é vista pelos musicólogos William Ashbrook e Harold Powers como marco do fim da grande tradição operística da Itália. O trabalho considera o entrelaçamento das convenções musicais e das convenções discursivas da partitura músico-textual de Turandot, a fim de esclarecer como analogias, referências e contradições musicais podem contribuir para a eficácia da narrativa verbal. O estudo de Turandot levou à reflexão da ópera como gênero e a dissertação está organizada pela gradual exploração das camadas da obra, da mais externa, a ópera em geral, até a reflexão sobre a psicologia de suas personagens, passando pela influência mútua entre música e narrativa nas idiossincrasias de Turandot como construção músico-literária singular. This paper intends to be an analysis from many angles of the opera Turandot, by Giacomo Puccini (1858-1924). Left incomplete by its composer and taken to the stage for the first time in 1926, this opera is regarded by musicologists William Ashbrook and Harold Powers as the ending of Italy's great operatic tradition. This work considers the intertwining of musical and speech conventions from Turandot's musical and textual score, with the objective of clarifying how musical analogies, references and contradictions may contribute to verbal narrative's effectiveness. The analysis of Turandot led to the reflection of opera as genre, so the paper is organized according to the gradual exploring of that opera's layers, from the most external - that is, the opera in general - to the reflection over its characters' psychology, passing by the mutual influence between music and narrative in Turandot's idiosyncrasies as a musical-literary unique construction
INFLUENCE OF THE CAST IRON’S CHEMICAL COMPOSITION ON THE CONTENT OF CR IN THE BASE AFTER NORMALIZATION FROM 1050 C
No full textThe dependences of the influence of the chemical composition of cast iron in the Fe-Cr-Mn-Ni system on the chromium cotent in the metal base (Cr1050о) and carbides (Cr1050Cr) after normalization from 1050 °C with aging for 4.5 hours were established. During the heat treatment of the castings, a redistribution of the elements between the phases of the cast iron occurred. The maximum chromium concentration in the base after normalization was 19.7% at 1.09% C, 3.1% Mn, 25.5% Cr and 0.19% Ni, and the minimum 2.4% at 3.91% C, 0.6% Mn, 11.43% Cr and 0.19% Ni. The maximum amount of chromium in carbides 78.4% was observed in cast iron containing 1.09% C, 5.4% Mn, 3.01% Ni and 25.57% Cr, and the minimum 43.5% at 3.59% C, 5.4% Mn, 3.01% N and11.43% Cr. The obtained dependencies allow predicting the chromium content in the metallic base and can be used during the elaboration of new compositions for wear-resistant cast iron, as well as at choice of heat treatment regimes
SCIENTIFIC BASIS OF ADDITIONAL FOOD INTRODUCTION, STATED IN THE NATIONAL PROGRAM OF THE INFANTS FEEDING OPTIMIZATION IN THE RUSSIAN FEDERATION. PART II
No full textThe article contains the results of the study of clinical and biochemical blood markers of iron metabolism in infants. This study represents a part of the research, aimed to scientific confirmation of the statements associated with additional food introduction and stated in the «National program of the infants feeding optimization in the Russian Federation». In controlled conditions the children were divided into 2 main groups: feeding with breast milk and with artificial milk formulas. Each group was divided into sub-groups according to the age of the additional food introduction: 4, 5 or 6 months. The received data suggest that the iron content was appropriate in both groups at the age of 4 months before the additional food introduction; there was a gradual decrease of several values after that, especially marked in children feeding with breast milk and later introduction of additional food. The comparative analysis showed that at the age of 9 months the lowest values were in breast-fed children with additional food introduction at the age of 6 months. This can be associated not only with late additional food introduction, but also with difficulties occurring when beginning it at this age and leading to insufficient supply with certain nutrients, including iron. The detailed analysis of diets for children of different sub-groups will be discussed in the next article
