Factores que motivan el uso de la biblioteca universitaria (The motivation’s factors to library university use)

Abstract: This paper presents the results of a documentary search about factors that motivate the use of university library. Literature about these factors was not found, either not standards or indicators used to measure those factors’ impact. On the other side, evidence was found about the decrease in library attendance, reported by the university libraries themselves; however, no evidence about the causes of this phenomenon was found. In such a context, this article presents a research project that will be applied in 3 universities at Northeast Mexico, in which a methodology to identify and analyze motivation in students to use the university library is proposed. Resumen: En este trabajo se presentan los resultados de la revisión documental sobre el tema de los factores que motivan el uso de la biblioteca universitaria. No se encontró literatura sobre estos factores y tampoco se encontraron normas o indicadores de referencia que permitan medir su impacto. Por otro lado, se encontró evidencia de un descenso en la asistencia reportada por las bibliotecas de las instituciones de educación superior, pero no se encontró evidencia de sus causas. Ante este escenario, en el presente artículo se plantea un proyecto de investigación que se aplicará en 3 universidades del noreste de México, en el cual se propone una metodología para identificar y analizar los factores que motivan, a sus estudiantes para utilizar la biblioteca universitaria

Design of Heterogeneous Hoveyda–Grubbs Second-Generation Catalyst–Lipase Conjugates

Heterogeneous catalysts have been synthesized by the conjugation of Hoveyda–Grubbs second-generation catalyst with a lipase. The catalytic properties of the organometallic compound in solution were firstly optimized, evaluating the activity of Ru in the ring-closing metathesis of diethyldiallymalonate at 25 °C at different solvents and in the presence of different additives. The best result was found using tetrahydrofuran as a solvent. Some additives such as phenylboronic acid or polyetheneglycol slightly improved the activity of the Ru catalyst whereas others, such as pyridine or dipeptides affected it negatively. The organometallic compound immobilized on functionalized-surface materials activated with boronic acid or epoxy groups (around 50–60 µg per mg support) and showed 50% conversion at 24 h in the ring-closing metathesis. Cross-linked enzyme aggregates (CLEA’s) of the Hoveyda–Grubbs second-generation catalyst with Candida antarctica lipase (CAL-B) were prepared, although low Ru catalyst was found to be translated in low conversion. Therefore, a sol–gel preparation of the Hoveyda–Grubbs second-generation and CAL-B was performed. This catalyst exhibited good activity in the metathesis of diethyldiallymalonate in toluene and in aqueous media. Finally, a new sustainable approach was used by the conjugation lipase–Grubbs in solid phase in aqueous media. Two strategies were used: one using lipase previously covalently immobilized on an epoxy-Sepharose support (hydrophilic matrix) and then conjugated with grubbs; and in the second, the free lipase was incubated with organometallic in aqueous solution and then immobilized on epoxy-Sepharose. The different catalysts showed excellent conversion values in the ring-closing metathesis of diethyldiallymalonate in aqueous media at 25 °C.This work was supported by the Spanish National Research Council (CSIC). The author thanks the Ramon Areces Foundation for financial support and the European community for an ERA HEI mobility grant to Anthony Neville. We acknowledge support by the CSIC Open Access Publication Initiative through its Unit of Information Resources for Research (URICI)

Kinetic study of methanol dehydration over Zro2 supported-activated carbons

The growing concerns about climate change and energy consumption have been the driving force in seek of alternative fuels such as DME, mainly produced via methanol dehydration over a solid acid catalyst. The use of activated carbons for this aim has been little studied up to date. Only a few studies can be found in the literature, reporting all of them materials with a low thermal stability of the acid surface groups, which results into a fast deactivation of the catalyst. In this work, the preparation of activated carbons via chemical activation with phosphoric acid, their modification with different ZrO2 loads, and their application as methanol dehydration catalysts have been studied. The catalytic results showed that the best methanol conversion and selectivity towards DME were achieved with the activated carbon prepared with an impregnation mass ratio value (H3PO4 /precursor) of 2 and an activation temperature of 800 ºC, loaded with a 7 % (wt) of ZrO2 . This catalyst exhibits high steady state methanol conversion values even at temperatures as high as 400 ºC (XCH3OH= 80%, 0.1 g·s/μmol, PCH3OH= 0.08 atm in helium), keeping a selectivity to DME higher than 96%. The effect of oxygen in the reaction atmosphere was also analysed. In this sense, an increase of 15 % in the DME yield was obtained when using air instead of helium as reaction atmosphere (350 ºC, 0.1 g·s/μmol, PCH3OH= 0.04 atm). A kinetic study has been carried out on this catalyst in which two mechanisms (Eley Rideal and Langmuir Hinshelwood) for methanol dehydration have been analysed. The models proposed also consider the presence of oxygen in the reaction media.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. MINECO (CTQ2015-68654-R). MECD (FPU13/02413)

Combinando enzimas y complejos organometálicos: nuevos biohibridos como catalizadores altamente eficientes

Los catalizadores de metales de transición y las enzimas poseen propiedades únicas y a menudo complementarias que los han convertido en herramientas importantes para la síntesis química. La combinación de un complejo organometálico catalíticamente activo con un hospedador macrobiomolecular permitiría diseñar nuevos catalizadores con alta eficacia y una gran amplitud de reacciones. De este modo, nuestro grupo se ha centrado en los últimos años en el desarrollo de nuevos tipos de metaloenzimas artificiales heterogéneas mediante dos estrategias principales, una la inserción del complejo organometálico en la estructura, principalmente en el sitio activo de diferentes enzimas y, más recientemente, hemos creado un nuevo tipo de nanobiohíbridos mediante un método eficiente y directo basado en la combinación de una enzima y sales de metales nobles para sintetizar nanopartículas metálicas generadas in situ sobre la estructura de la proteína. Estos nuevos catalizadores heterogéneos se han utilizado con éxito en diferentes reacciones sintéticas en condiciones suaves, formación de enlaces C-C, activación C-H o metátesis de cierre de anillo. La actividad dual (metálica y enzimática) ha permitido su uso en procesos en cascada. El potencial de estos nanobiohíbridos se ha utilizado recientemente con éxito en la remediación de contaminantes orgánicos, y podría extenderse a otras aplicaciones potenciales como la biomedicina, la energía, etc.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. Departamento de Química Orgánic

Factores endógenos y exógenos que impactan en el uso de la biblioteca en tres universidades del área metropolitana de Monterrey, Nuevo León

La presente investigación se propuso identificar los factores que motivan a los estudiantes de tres instituciones de educación superior del área metropolitana de Monterrey a utilizar la biblioteca universitaria. Para abordar la cuestión se diseñó un modelo de análisis multivariable que integra nueve factores, los cuales se desprenden de la propia operación de la biblioteca (factores endógenos), así como del contexto académico y cultural en el cual ésta efectúa su función (factores exógenos). El modelo se aplicó a las percepciones de una muestra estratificada de alumnos de sexto semestre de las tres instituciones participantes, medidas con el auxilio de una escala de Likert. Los resultados comprobaron la predicción del modelo y mostraron la existencia de cinco variables que impactan de manera significativa en el uso de la biblioteca universitaria. Posteriormente se analizaron muestras individuales de las tres instituciones y se agrupó a los alumnos en tres áreas de conocimiento. Se obtuvieron resultados significativos diferentes en cada una de las muestras. Abstract The purpose of this research was to identify the factors that motivate students to use libraries in three universities in metropolitan Monterrey. The study employed a multivariate analysis model incorporating factors associated exclusively with the library’s operation (endogenous factors) and factors associated with the academic and cultural context in which the library operates (exogenous factors). A stratified sample of sixth semester students enrolled in the three universities responded to the instrument designed to measure the target perceptions. Results show that five variables (out of nine) predicted by the model in fact significantly influence use of the university library. Additionally, the study analyzes individual samples from the three universities, grouping these into three major knowledge areas. Measures of library use for these groups are significantly distinct

Pixel Features for Self-organizing Map Based Detection of Foreground Objects in Dynamic Environments

Among current foreground detection algorithms for video sequences, methods based on self-organizing maps are obtaining a greater relevance. In this work we propose a probabilistic self-organising map based model, which uses a uniform distribution to represent the foreground. A suitable set of characteristic pixel features is chosen to train the probabilistic model. Our approach has been compared to some competing methods on a test set of benchmark videos, with favorable results.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Synthesis of heterogeneous enzyme-metal nanoparticle biohybrids in aqueous media and their applications in C-C bond formation and tandem catalysis

The straightforward synthesis of novel enzyme-metalNP nanobiohybrids in aqueous medium was developed. These new nanobiohybrids were excellent multivalent catalysts combining both activities in various sets of synthetic reactions even at ultra-low concentrations (ppb amount). © 2013 The Royal Society of Chemistry.This research was supported by The Spanish National Research Council (CSIC). Authors thank European Community (FP7-MULTIFUN) for the contract of M.M.Peer Reviewe

Biomass derived activated carbon catalysts for the one-step dimethyl ether synthesis from syngas

Se trata de un resumen extendido de una comunicación a congreso internacional.In this work we study the behaviour of a carbon-based catalyst for this one-step synthesis process. Two kinds of activated carbons, prepared by chemical (with H3PO4) and physical (by CO2 partial gasification) activation of olive stones, were used as catalysts support. The main difference between the activated carbons was the presence of chemically stable phosphorus surface groups, mainly in form of C-O-PO3 groups1, on the activated carbon prepared via chemical activation. The addition of Zr to the chemically activated carbon (ACPZr) resulted in the formation of zirconium phosphate species on the carbon surface, which were capable of promoting the selective methanol dehydration to DME. Cu-Zn loading on the chemically activated carbon resulted in strong interactions between the metallic phase and the phosphate surface groups due to the formation Cu phosphate species. The bifunctional catalyst, ACPZrCuZn showed less conversion that the physical mixture. This fact is related with the presence of phosphorus species that avoids the reduction of the metal (copper).Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Outsourcing de software: Variables críticas en el proceso de toma de decisiones (Software outsourcing: Variables involved in decision making)

Abstract. The Software Outsourcing has become a solution for organizations or businesses, due to various reasons or variables that range from reducing costs to keep their technology updated. Outsourcing is defined as business processes that are performed by an organization (Supplier) establishes a contractual relationship (Costumer-Supplier) and is given the responsibility for execution of business processes to the supplier. Based on the significant investment in imports generated by companies in Mexico, it was performed a literature review to identify the key variables that, in principle, influence the decision to turn to Software Outsourcing and, at the end, we propose a Software Outsourcing Model. Resumen. El Outsourcing de Software se ha convertido en una solución para las organizaciones o empresas, debido a diferentes motivos o variables que van desde reducir costos hasta mantener su tecnología actualizada. El Outsourcing lo definimos como los procesos de negocio que son realizados por una organización (Proveedor), se establece una relación contractual (Cliente-Proveedor) y se le da la responsabilidad de la ejecución de los procesos de negocio al proveedor. Partiendo de la importante inversión en importaciones, generada por las empresas en México, se realiza una revisión de literatura para identificar las principales variables que, en principio, influyen en la decisión de recurrir al Outsourcing de Software y, finalmente, se propone un Modelo de Outsourcing de Software