In present study Fe-29.0Mn-6Al-0.9C-1.8Mo-1.6Si-0.4Cu (%w) alloy was obtained after melted in an induction furnace, and then molded as an ingot. From the as cast ingot it were cut samples for the different characterization measurements. The microstructure of the as-cast sample is of dendritic type and its XRD pattern was refined with the lines of the austenite, with a big volumetric fraction, and the lines of the martensite, with small volumetric fraction. The Mössbauer spectrum of the sample was fitted with a broad singlet which corresponds to disordered austenite. After the tribology test, its XRD pattern was refined with the lines of two austenite phases, one similar to the previous one and other with bigger lattice parameter. The total volumetric fraction of the austenite is smaller than that obtained for sample without wear. It was added the lines of the martensite phase with bigger volumetric fraction than that of the previous sample. The Mössbauer spectrum of the weared sample was fitted with two paramagnetic sites which correspond to the two Fe austenite phases and a hyperfine magnetic field distribution which is associated to the disordered original martensite and the new one which appears in the surface as a consequence of the wear process. These results show that during wear process the original austenite phase is transformed in martensite and in a new austenite phase. The increases of the martensitic phase improves mechanical properties and wear behavior.

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Se evaluó el desempeño de 288 niños de primer grado en tareas de lectura y escritura de diferente grado de complejidad. Se tomaron como predictores de los desempeños en las tareas evaluadas variables asociadas con la práctica docente y con antecedentes académicos inmediatos de los niños, así como sus características físicas. Mediante la aplicación de un análisis de regresión múltiple se identificó que las variables de años de experiencia del maestro en primer grado, el juicio que emite respecto a la adquisición de la lectura y la escritura del niño, la presencia de padecimientos de tipo auditivo y/o visual en el niño, y el promedio logrado por los niños en los cursos de español al término del año escolar predicen aproximadamente un 40% del desempeño de los niños en todos los niveles de complejidad de las tareas de lectura y escritura evaluadas. Se discuten los resultados en términos de su implicación en la práctica docente.