Análisis exergético de escenarios integrados de producción de etanol y otros productos a partir de la caña de azúcar

Se realiza el análisis exergético de seis escenarios parala producción conjunta de alcohol y otros productos derivados de la caña de azúcar, con el objetivo de identificar y localizar las principales fuentes generadoras de irreversibilidades en estos esquemas. En los esquemas integrados se considera la caña de azúcar como materia prima principal para la generación de productos y coproductos. Los seis escenarios de integración evaluados incluyen la producción de azúcar, alcohol de primera y segunda generación y coproductos tales como: furfural y lignina, la obtención de levadura torula y la recuperacióndel CO2. Se realizaron los balances de masa y energía para cada proceso, determinando los flujos de las corrientes que intervienen en el análisis exergético. Para el análisis exergético el esquema integrado fue dividido en diez subsistemas. Los subsistemas extracción de jugo, cristalización y cocción, fermentación y destilación resultaron los mayores generadores de pérdidas exergéticas. Para los primeros cinco escenarios la eficiencia exergética total se encuentra entre 71-80% y para el escenario de tiempo de no zafra en un 59%

Professional motives in primary school teachers

The purpose of this study was to analyze the professional motives of primary school teachers and their relation to the teaching/learning process. This research relies on the historic. cultural paradigm and the activity theory, especially the categories of motives proposed by A. Leontiev and N. Talizina. The study was based on semi.structured interviews with a teacher and six students of the 6th grade of a private urban primary school. It also included analysis of their written narratives and a video recording of a class session. Our findings suggest a relationship between the teacher’s motives and the students’ learning process

La Grotte Chauvet y la división "arte mobiliar" -"arte parietal"

En recientes trabajos hemos analizado la formación histórica y el significado de la dicotomía “arte parietal”- “arte mobiliar”, división que, en nuestra opinión, ha estructurado nuestra comprensión del arte paleolítico. Tomando como ejemplo la controversia a propósito de la Grotte Chauvet- Pont- d’Arc, nos proponemos mostrar en este artículo la importancia que dicha dicotomía ejerce sobre la percepción occidental del arte paleolítico. Las dataciones de 14C AMS que asignaban una antigüedad a las pinturas de Chauvet de entre 33000 y 30000 BP provocaron que la mayoría de especialistas considerasen esta cueva como un conjunto único y extraordinario. Esta idea está relacionada con el hecho de que las pinturas se compararon principalmente con el arte parietal y no con el arte mobiliar, a pesar de su paralelismo con las pequeñas estatuillas auriñacienses encontradas en el sur de Alemania. La polémica a propósito de Chauvet ilustra el peso que la dicotomía mobiliar-parietal tiene sobre nuestra manera decomprender el arte paleolítico

La administración electrónica en los municipios de Toluca y Metepec, Estado de México

This paper attempts to conceptualize the elements and characteristics of electronic management in order to analyze progress in two municipalities of the State of Mexico. We argue that electronic management allows for the optimization of service provision, improves access to information, generates economies of scale and reduces the unit cost of each government operation, improving citizen response capacity. From the comparison between both cases, we conclude that there has been important progress but there is still much that can be done to improve the link between thecitizen and public administration.    El trabajo busca conceptualizar la administración electrónica, sus elementos y características para analizar los avances de dos municipios del Estado de México. Se argumenta que la administración electrónica permite la optimización en la prestación de los servicios, mejora el acceso a la información, genera economías de escala y reduce el costo unitario de cada operación del gobierno, mejorando la capacidad de respuesta a losciudadanos. De la comparación de ambos casos, se concluye que han existido avances importantes pero que aun queda mucho por hacer para mejorar, por esta vía, la vinculación entre el ciudadano y la administración pública.  

In vivo extracellular matrix protein expression by human periodontal ligament after stimulation with orthodontic force

It is well known that the orthodontic force applied to teeth generates a series of events that remodel the periodontal ligament (PDL). Extracellular matrix proteins (ECM) are described as molecular regulators of these events. However, the exact contribution of these proteins in human PDL modeling by orthodontic force application in vivo is not known. The aim of this present study was to evaluate the protein expression of fibronectin, laminin and vitronectin by human PDL from teeth on which orthodontic force was applied. Twenty healthy individuals were included in the study. PDL was obtained from teeth after a 3-week treatment with orthodontic force. PDL-protein samples were separated on 7.5% SDS-PAGE Western blot analysis with specific monoclonal antibodies for fibronectin, laminin and vitronectin. Bands were visualized with an enhanced chemiluminescence detection system and densitometric. Scanning of bands was carried out to compare differences in protein expression. A significant increment in fibronectin (13.9%), laminin (16.5%) and vitronectin (14.2%) expression was found in PDL from teeth treated with orthodontic force for 3 weeks in comparison with teeth in the control group. Our results support the concept that molecular changes take place by application of orthodontic forces to the PDL. Over expression of these proteins suggests that extracellular matrix (ECM) remodeling could be generated in response to mechanical stress.Keywords: Extracellular matrix proteins, periodontal ligament, orthodontic forceAfrican Journal of Biotechnology Vol. 9(34), pp. 5599-5604, 23 August, 201

A molecular clock for autoionization decay

The ultrafast decay of highly excited electronic states is resolved with a molecular clock technique, using the vibrational motion associated to the ionic bound states as a time-reference. We demonstrate the validity of the method in the context of autoionization of the hydrogen molecule, where nearly exact full dimensional ab-initio calculations are available. The vibrationally resolved photoionization spectrum provides a time-energy mapping of the autoionization process into the bound states that is used to fully reconstruct the decay in time. A resolution of a fraction of the vibrational period is achieved. Since no assumptions are made on the underlying coupled electron-nuclear dynamics, the reconstruction procedure can be applied to describe the general problem of the decay of highly excited states in other molecular targetsWe acknowledge the financial support from the FP7 Marie Curie ITN CORINF, the European Research Council under the ERC grant 290853 XCHEM, the European COST Action CM1204 XLIC and the MINECO Project No. FIS201342002-R. AP acknowledges Ramón y Cajal Programme from MINECO (Spain). LM acknowledges support from DFG priority programme 1840 QUTIF. Theoretical calculations were obtained at the Mare Nostrum BSC and CCC-UAM computer center

La competitividad en la industria de la construcción en México

14 páginasEl sector de la construcción de México, depende de la eficiencia para satisfacer las necesidades actuales que reclama la sociedad para sustentar el crecimiento y el progreso que necesita. La construcción de la infraestructura del país ha sido casi detenida en las últimas tres décadas, habiendo rezago en el desarrollo social y económico, como consecuencia de la deficiente administración del país. En este sentdo, los factores para analizar son: Las necesidades y proyectos de infraestructura (carreteras, puertos y aeropuertos, agua, energía proyectos de apoyo); las firmas de ingeniería; las empresas constructoras; el financiamiento y las decisione

In vitro study of antiamoebic activity of methanol extract of fruit of Pimpinella anisum on trophozoites of Entamoeba histolytica HM1-IMSS

The aniseed plant Pimpinella anisum (Saunf-Hindi) is one of the most ancient medicinal plants used by man. Currently, this plant has several uses in the food industry as spice, whereas in the pharmacopoeia, it is used as an expectorant in digestive disturbances, as mild diuretic, and as insect repellent in external use. In this paper, we evaluated the biological activity of methanolic extract of P. anisum on in vitro growth of Entamoeba histolytica HM1-IMSS under axenic conditions. We observed that the growth inhibition of E. histolytica was at CI50 = 0.034 μg/mL. Results confirm the antiamoebic activity of the methanolic extract of P. anisum.Keywords: Pimpinella anisum, Entamoeba histolytica, antiamoebic activity, medicinal plantsAfrican Journal of Biotechnology Vol. 12(16), pp. 2065-206

A molecular clock for autoionization decay

The ultrafast decay of highly excited electronic states is resolved with a molecular clock technique, using the vibrational motion associated to the ionic bound states as a time-reference. We demonstrate the validity of the method in the context of autoionization of the hydrogen molecule, where nearly exact full dimensional ab-initio calculations are available. The vibrationally resolved photoionization spectrum provides a time–energy mapping of the autoionization process into the bound states that is used to fully reconstruct the decay in time. A resolution of a fraction of the vibrational period is achieved. Since no assumptions are made on the underlying coupled electron–nuclear dynamics, the reconstruction procedure can be applied to describe the general problem of the decay of highly excited states in other molecular targets