Un problema de la enseñanza – aprendizaje del análisis químico instrumental es el alto costo de la instrumentación comercial, incluyendo aspectos de mantenimiento y servicio. Esto limita el acceso de los estudiantes a la operación directa de los diversos instrumentos, comprometiendo la calidad de su formación profesional. En este trabajo se describe detalladamente un espectrómetro de luz visible de 390 – 650 nanómetros, de fácil construcción, bajo costo, robusto y de altas prestaciones, adecuado para espectro-fotometría de absorción y fluorescencia moleculares y emisión atómica. El espectrómetro no tiene partes móviles y usa como detector una cámara web conectada a una computadora personal, que permite la adquisición, presentación, procesamiento y registro de los espectros, a condiciones elegidas por el experimentador. El dispersor es la cara metálica interna de u...

The characteristics of a low cost, easy to construct, homemade Raman spectrometer are described and its performance presented and discussed. The light sensor of the spectrometer is a consumer grade EOS DSLR camera; the instrument uses a green laser pointer for signal excitation of transparent liquid samples, in transmission mode. The spectral resolution is approximately 15 cm-1.Construction, operation, calibration and image processing aspects are explained in detail. Good quality Raman spectra obtained for few pure liquids (benzene, carbon tetrachloride, and toluene) and mixtures (naphthalene – benzene – carbon tetrachloride and 96% volume rectified ethanol) are presented and discussed. It is proposed that the construction of the described spectrometer could be assigned as a project to student groups, under teacher guidance, providing a valuable opportunity of project based meaningfu...

Se ha estandarizado una posición de irradiación del reactor nuclear RP-10 para el uso del análisis por activación neutrónica según el método del k sub cero, empleando la convención de Högdahl y se ha evaluado el comportamiento de dicho método respecto a la exactitud y precisión de los resultados obtenidos en el análisis multielemental cuantitativo de diversos materiales certificados de referencia. Para comprobar que el método analítico se encuentra totalmente bajo control estadístico, se ha empleado el método de Heydorn. Se ha constatado que el método es exacto, preciso y confiable para la determinación de aluminio, antimonio, arsénico, bromo, calcio, cloro, cobre, magnesio, manganeso, sodio, titanio, vanadio, zinc y otros elementos. También se discuten, en relación al uso de las constantes k sub cero, los diversos formalismos empleados para calcular la integral de l...

aarbildo@ulima.edu.pe; emontoya@ipen.gob.pe

aarbildo@ulima.edu.pe

aarbildo@ulima.edu.pe

As a result of the development of low cost and high-performance scientific instruments, it has been developed some experimental set ups, measurement methods and tools (numerical and graphic) in order to obtain trustable results. Some of the assays were proof of concept that, in spite of been qualitative, have been rescued taking into account their value in the understanding of physical and chemical phenomena useful for teaching Science and Engineering. Some cases, developed by using two of the resources normally standard in personal computers such as the microphone and web cam, for sound-based tests and visible light as well as Raman spectrometry, are presented. The techniques have been developed in support of the development of Scientific Alternative Instruments (ICA in Spanish).

Indexado en Latindex (Catálogo 2.0) y DOAJ

As a result of the development of low cost and high-performance scientific instruments, it has been developed some experimental set ups, measurement methods and tools (numerical and graphic) in order to obtain trustable results. Some of the assays were proof of concept that, in spite of been qualitative, have been rescued taking into account their value in the understanding of physical and chemical phenomena useful for teaching Science and Engineering. Some cases, developed by using two of the resources normally standard in personal computers such as the microphone and web cam, for sound-based tests and visible light as well as Raman spectrometry, are presented. The techniques have been developed in support of the development of Scientific Alternative Instruments (ICA in Spanish).

El volcán Sabancaya , situado al sur de Perú dentro de la Zona Volcánica Central de los Andes , ha estado en erupción constante desde noviembre de 2016.La ocurrencia diaria de explosiones de tipo vulcaniano (series de explosiones de corta duración) hace de Sabancaya un valioso laboratorio natural para estudiar dicha actividad. En este estudio, examinamos las columnas eruptivas producidas durante estas explosiones utilizando imágenes tanto visibles como infrarrojas. Categorizamos dos tipos de columnas, cada una de ellas con características distintivas: (a) columnas que presentan una cabeza amorfa con vórtices ; y (b) columnas con formas estrechas y cilíndricas que carecen de grandes estructuras vorticiales. Nuestros resultados sugieren que estas categorías representan miembros finales de la morfología de la columna en Sabancaya . Empleamos un modelo numérico para analizar las ...

The characterisation of tephra deposits resulting from almost simultaneous sedimentation and wind remobilisation is complex, and multidisciplinary strategies are required in order to accurately constrain associated processes and eruptive parameters. We present a multifaceted study that aims to characterise the recent eruptive activity and the subsequent aeolian remobilisation of tephra deposits at Sabancaya volcano (Peru), which started erupting in November 2016 with frequent and relatively small explosions (plume heights <6 km above the vent). First, we estimated the bulk volume of tephra deposit produced between November 2016 and August 2018 at 0.04 ± 0.02 km3, and the dense rock equivalent (DRE) volume at 0.02 ± 0.01 kilometros3. This corresponds to a tephra production rate of 1.1 ± 0.5 x 10−3 km3 DRE per month. Second, continuous sampling in a dedicated tephra collector network ...