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We present the experimental details and results from a low energy but high repetition rate compact plasma capillary source for extreme ultraviolet and soft x-ray research and applications. Two lengths of capillary are mounted in two versions of a closely related design. The discharge operates in 1.6 and 3.2 mm inner diameter alumina capillaries of lengths 21 and 36 mm. The use of water both as dielectric and as coolant simplifies the compact low inductance design with nanosecond discharge periods. The stored electrical energy of the discharge is approximately 0.5 J and is provided by directly charging the capacitor plates from an inexpensive insulated-gate bipolar transistor in 1 μs or less. We present characteristic argon spectra from plasma between 30 and 300 Å as well as temporally resolved x-ray energy fluence in discrete bands on axis. The spectra also allow the level of ablated wall material to be gauged and associated with useful capillary lifetime according to the chosen configuration and energy storage. The connection between the electron beams associated with the transient hollow cathode mechanism, soft x-ray output, capillary geometry, and capillary lifetime is reported. The role of these e-beams and the plasma as measured on-axis is discussed. The relation of the electron temperature and the ionization stages observed is discussed in the context of some model results of ionization in a non-Maxwellian plasma.

RESUMENEl presente artículo sugiere esquemas teóricos que parecieran ser más pertinentes para la formación motivacional de futuros profesores. Ello surge de la constatación de que la formación motivacional de los estudiantes de pedagogía muchas veces se hace a partir de modelos teóricos que si bien pueden ser muy predictivos, no son lo suficientemente adecuados para proponer pistas que focalicen la intervención pedagógica en la motivación por el aprendizaje. Se discuten distintas aproximaciones teóricas reconociendo sus aportes y limitaciones y se propone, finalmente, un esquema teórico que puede contribuir de manera pertinente a que los futuros docentes tengan elementos teóricos sobre los cuales sostener sus esfuerzos por motivar a sus alumnos, focalizándose en los factores motivacionales del aprendizaje y dejando atrás nociones generales o teóricamente poco pertinentes para este fin.Palabras clave: motivación, motivación escolar, formación docente, profesorado, teoría motivacional. ABSTRACT This article suggests theoretical schemes that seem most relevant to motivational training of future teachers. This arises from the observation that pedagogy students' motivational training is often made from theoretical models that, while they may be very predictive, are not adequate enough to offer clues for pedagogical intervention that focus on motivation for learning. Different theoretical approaches are discussed recognizing their contributions and limitations. Finally, we propose a theoretical framework that can contribute, in a relevant way for future teachers, to acquire theoretical elements which sustain their efforts to motivate their students, focusing on learning the motivational factors and leaving behind notions theoretically less relevant for this purpose.

Introduction. The present work reports the characteristics of an instrument measuring the

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Dada la importancia de la lectura académica en la formación universitaria y que uno de los factores gravitantes en este tipo de tarea son los aspectos motivacionales, el presente trabajo tuvo como objetivo identificar los elementos, que según los propios protagonistas explicarían el incremento de su motivación por la lectura de textos académicos. El estudio de carácter mixto se realizó en dos fases. En una primera fase, de corte cuantitativo, fueron identificados a partir de una muestra amplia (n=1205) estudiantes con alta motivación por la lectura académica y que hubiesen experimentado un cambio motivacional positivo (n=10). En una segunda fase, estos casos fueron sujetos de entrevistas en profundidad y el análisis de estas entrevistas se recoge en este artículo. Los resultados muestran como causas de la mejora de la motivación por la lectura académica, dinámicas vinculadas con el desafío, el ingreso a la lógica universitaria (desescolarización) y las proyecciones académico/profesionales de estos estudiantes; procesos que se encuentran vinculados a los primeros años de formación, favorecidos por docentes que promueven una dinámica académica en la formación. Se discuten finalmente las implicaciones de estas dinámicas para el conjunto de la formación universitaria.

Due to the widespread use of cyanide in mining operations, its recovery and destruction is important for both the environmental aspects of wastewater and its treatment, and the economic aspects associated with the high consumption of chemicals by the process itself. A photoelectrocatalytic detoxification technique with titanium dioxide microelectrodes is one of the most innovative ways for the treatment of wastewater containing cyanide. However, this technique has a disadvantage for industrial application in that the separation of titanium dioxide after the photocatalytic degradation of cyanide is rather difficult due to the fineness of the particles, and therefore, the reuse of the titanium dioxide has not been attained for the treatment of cyanide-containing wastewater. To overcome this weak point, an electrocoagulation (EC) technique is used to recover the titanium dioxide from its aqueous suspensions. The results show that photodegradation of cyanide is 93 % in 30 min using a 450 W halogen lamp. The recovery of anatase with the EC process is 98 %. The results indicate that this technique has the potential to serve as a reliable and economical method because sunlight can be used efficiently as the power source. The Langmuir isotherm is used to obtain the thermodynamic parameters, i.e., free energy, enthalpy and entropy. The evaluation of these parameters, i.e., DG°= -37 kJ/mol, DH°= -54 kJ/mol and DS°= 0.524 kJ/mol K, indicates the spontaneous and exothermic nature of the adsorption of the anatase particles on the iron species.

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