9,268 research outputs found

    Evaluating the impact of strategic personnel policies using a MILP model: the public university case

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    Purpose: The main purpose of the paper is to evaluate the impact of diverse personnel policies around personnel promotion in the design of the strategic staff plan for a public university. The strategic staff planning consists in the determination of the size and composition of the workforce for an organization. Design/methodology/approach: The staff planning is solved using a Mixed Integer Linear Programming (MILP) model. The MILP model represents the organizational structure of the university, the personnel categories and capacity decisions, the demand requirements, the required service level and budget restrictions. All these aspects are translated into a set of data, as well as the parameters and constraints building up the mathematical model for optimization. The required data for the model is adopted from a Spanish public university. Findings: The development of appropriate policies for personnel promotion can effectively reduce the number of dismissals while proposing a transition towards different preferable workforce structures in the university. Research limitations/implications: The long term staff plan for the university is solved by the MILP model considering a time horizon of 8 years. For this time horizon, the required input data is derived from current data of the university. Different scenarios are proposed considering different temporal trends for input data, such as in demand and admissible promotional ratios for workers. Originality/value: The literature review reports a lack of formalized procedures for staff planning in universities taking into account, at the same time, the regulations on hiring, dismissals, promotions and the workforce heterogeneity, all considered to optimize workforce size and composition addressing not only an economic criteria, but also the required workforce expertise and the quality in the service offered. This paper adopts a formalized procedure developed by the authors in previous works, and exploits it to assess the impact of various personnel policies in the staff planning for a particular university case, and this is the principal contribution of the paper.Postprint (published version

    Using Mobile Devices for Improving Learning Outcomes and Teachers’ Professionalization

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    Teaching in higher education is changing due to the influence of technology. More and more technological tools are replacing old teaching methods and strategies. Thus, mobile devices are being positioned as a key tool for new ways of understanding educational practices. The present paper responds to a systematic review about the benefits that mobile devices have for university students’ learning. Using inclusion and exclusion criteria in theWeb of Science and Scopus databases, 16 articles were selected to argue why Mobile learning (Mlearning) has become a modern innovative approach. The results point to an improvement in students’ learning through Mlearning, factors that encourage the use of mobile devices in universities have been identified, and e ective mobile applications in improving teaching and learning processes have been presented. The inclusion of this methodology requires a new role for teachers, whose characterization is also specified

    Potential Protective Role Exerted by Secoiridoids from Olea europaea L. in Cancer, Cardiovascular, Neurodegenerative, Aging-Related, and Immunoinflammatory Diseases

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    Iridoids, which have beneficial health properties, include a wide group of cyclopentane [c] pyran monoterpenoids present in plants and insects. The cleavage of the cyclopentane ring leads to secoiridoids. Mainly, secoiridoids have shown a variety of pharmacological effects including anti-diabetic, antioxidant, anti-inflammatory, immunosuppressive, neuroprotective, anti-cancer, and anti-obesity, which increase the interest of studying these types of bioactive compounds in depth. Secoiridoids are thoroughly distributed in several families of plants such as Oleaceae, Valerianaceae, Gentianaceae and Pedialaceae, among others. Specifically, Olea europaea L. (Oleaceae) is rich in oleuropein (OL), dimethyl-OL, and ligstroside secoiridoids, and their hydrolysis derivatives are mostly OL-aglycone, oleocanthal (OLE), oleacein (OLA), elenolate, oleoside-11-methyl ester, elenoic acid, hydroxytyrosol (HTy), and tyrosol (Ty). These compounds have proved their efficacy in the management of diabetes, cardiovascular and neurodegenerative disorders, cancer, and viral and microbial infections. Particularly, the antioxidant, anti-inflammatory, and immunomodulatory properties of secoiridoids from the olive tree (Olea europaea L. (Oleaceae)) have been suggested as a potential application in a large number of inflammatory and reactive oxygen species (ROS)-mediated diseases. Thus, the purpose of this review is to summarize recent advances in the protective role of secoiridoids derived from the olive tree (preclinical studies and clinical trials) in diseases with an important pathogenic contribution of oxidative and peroxidative stress and damage, focusing on their plausible mechanisms of the action involved.España Ministerio de Economía y Competitivida

    High-level quinolone resistance is associated with the overexpression of smeVWX in Stenotrophomonas maltophilia clinical isolates

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    AbstractStenotrophomonas maltophilia is the only known bacterium in which quinolone-resistant isolates do not present mutations in the genes encoding bacterial topoisomerases. The expression of the intrinsic quinolone resistance elements smeDEF, smeVWX and Smqnr was analysed in 31 clinical S. maltophilia isolates presenting a minimum inhibitory concentration (MIC) range to ciprofloxacin between 0.5 and > 32 μg/mL; 11 (35.5%) overexpressed smeDEF, 2 (6.5%) presenting the highest quinolone MICs overexpressed smeVWX and 1 (3.2%) overexpressed Smqnr. Both strains overexpressing smeVWX presented changes at the Gly266 position of SmeRv, the repressor of smeVWX. Changes at the same position were previously observed in in vitro selected S. maltophilia quinolone-resistant mutants, indicating this amino acid is highly relevant for the activity of SmeRv in repressing smeVWX expression. For the first time SmeVWX overexpression is associated with quinolone resistance of S. maltophilia clinical isolates

    Influencia de la expropiación forzosa en la disponibilidad de terrenos para la ejecución de obras de modernización de regadíos

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    La evolución de la economía del país, ha hecho que los tipos de interés hayan disminuido de manera continuada en los últimos años. El hecho de que la determinación del valor de expropiación desde el año 2.007 se lleve a cabo mediante capitalización de rentas y que, por lo tanto, el valor de indemnización dependa del tipo de interés, ha ocasionado un efecto económico difícil para las partes beneficiarias en una expropiación. En este trabajo se estudia la evolución de la normativa, se cuantifican los resultados para el caso de una finca concreta de una explotación de algodón de regadío en el valle del Guadalquivir y se analizan los resultados. En el estudio puede observarse que en los últimos ocho años, el valor de mercado de la tierra ha seguido una tendencia a la baja. Por el contrario, el valor de indemnización por expropiación de la misma se ha disparado, lo que hace inviable a las comunidades de regantes la participación en la modernización de regadíos, así como a la Administración la aplicación del Plan Hidrológico Nacional o Plan Nacional de Regadíos. Estas circunstancias han hecho que, en octubre de 2.015 (Ley de carreteras) y noviembre de 2.015 (Texto refundido de Ley de Suelo), la legislación haya intentado paliar la situación, aunque sigue siendo insuficiente. Por ello se proponen algunas medidas a modo de conclusión al final del trabajo.The evolution of the country's economy has made that interest rates have decreased continuously in recent years. The fact that since the year 2007 the determination of the value of expropriation is being carried out through revenue capitalization, in which the indemnification value depends on the interest rate, has caused a difficult economic impact in the recipient parties of an expropriation. In this paper we study the evolution of the expropriation regulations as well as the assessment of the amount of money corresponding to the expropriation of a farm dedicated the production of cotton in the Guadalquivir valley. In the study it can be seen that over the last eight years the market value of the land has followed a downward trend. On the other hand, the value of compensation for land expropriation has been triggered, making infeasible to the irrigation communities their participation in the modernization of the irrigation systems and hinders the Administration the implementation of the National Hydrological Plan or the National Irrigation Plan. These circumstances have led the Government to try to alleviate the situation with new regulations (road act of October 2015 and revised text of law of soil of November 2015) which remain insufficient. Therefore some legislative proposals are given as conclusions at the end of this work

    Application of a one-dimensional spray model to teach diffusion flame fundamentals for engineering students

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    [EN] This study presents the application of an existing interactive application for teaching spray dynamics in engineering degrees. The model is based on spray momentum conservation and can be used to evaluate both fuel-air mixing characteristics in inert conditions as well as diffusion flame performance once combustion takes place. During a dedicated computer-lab session, the students perform parametric studies regarding the influence of the nozzle outlet diameter, the combustion chamber density and the spray cone opening angle on the mixing process, characterized by the maximum stoichiometric length. Later on, the effect of the combustion reaction on the mixing field is evaluated. The results are analyzed taking as a reference to the theoretical development made by Spalding and Schlichting for diffusion gas jets. The outcomes of several years using this technique are reported.García-Oliver, JM.; García Martínez, A.; De La Morena, J.; Monsalve-Serrano, J. (2019). Application of a one-dimensional spray model to teach diffusion flame fundamentals for engineering students. Computer Applications in Engineering Education. 27(5):1202-1216. https://doi.org/10.1002/cae.22146S12021216275Aleiferis, P. G., Behringer, M. K., & Malcolm, J. S. (2016). Integral Length Scales and Time Scales of Turbulence in an Optical Spark-Ignition Engine. Flow, Turbulence and Combustion, 98(2), 523-577. doi:10.1007/s10494-016-9775-9Battin-Leclerc, F. (2008). Detailed chemical kinetic models for the low-temperature combustion of hydrocarbons with application to gasoline and diesel fuel surrogates. Progress in Energy and Combustion Science, 34(4), 440-498. doi:10.1016/j.pecs.2007.10.002Burke, R. D., De Jonge, N., Avola, C., & Forte, B. (2017). A virtual engine laboratory for teaching powertrain engineering. Computer Applications in Engineering Education, 25(6), 948-960. doi:10.1002/cae.21847Desantes, J. M., Pastor, J. V., García-Oliver, J. M., & Briceño, F. J. (2014). An experimental analysis on the evolution of the transient tip penetration in reacting Diesel sprays. Combustion and Flame, 161(8), 2137-2150. doi:10.1016/j.combustflame.2014.01.022Desantes, J. M., Pastor, J. V., García-Oliver, J. M., & Pastor, J. M. (2009). A 1D model for the description of mixing-controlled reacting diesel sprays. Combustion and Flame, 156(1), 234-249. doi:10.1016/j.combustflame.2008.10.008Dumouchel, C., Cousin, J., & Triballier, K. (2005). On the role of the liquid flow characteristics on low-Weber-number atomization processes. Experiments in Fluids, 38(5), 637-647. doi:10.1007/s00348-005-0944-1Edmonds, E. (1980). Where Next in Computer Aided Learning? British Journal of Educational Technology, 11(2), 97-104. doi:10.1111/j.1467-8535.1980.tb00396.xFansler, T. D., & Parrish, S. E. (2014). Spray measurement technology: a review. Measurement Science and Technology, 26(1), 012002. doi:10.1088/0957-0233/26/1/012002Gutiérrez-Romero, J. E., Zamora-Parra, B., & Esteve-Pérez, J. A. (2016). Acquisition of offshore engineering design skills on naval architecture master courses through potential flow CFD tools. Computer Applications in Engineering Education, 25(1), 48-61. doi:10.1002/cae.21778IPCC. Intergovernmental Panel on Climate Change Working Group I. Climate Change 2013: The Physical Science Basis.Long‐term Climate Change: Projections Commitments and Irreversibility  Cambridge University Press New York NY  2013:1029–136.https://doi.org/10.1017/CBO9781107415324.024W. Kirchstetter, T., Harley, R. A., Kreisberg, N. M., Stolzenburg, M. R., & Hering, S. V. (1999). On-road measurement of fine particle and nitrogen oxide emissions from light- and heavy-duty motor vehicles. Atmospheric Environment, 33(18), 2955-2968. doi:10.1016/s1352-2310(99)00089-8K. BenNaceur L.Cozzi andT.Gould.World Energy Outlook 2016.2016.https://doi.org/10.1787/weo‐2016‐enM.Nesbitet al. Comparative Study on the differences between the EU and US legislation on emissions in the automotive sector.2016.PASTOR, J., JAVIERLOPEZ, J., GARCIA, J., & PASTOR, J. (2008). A 1D model for the description of mixing-controlled inert diesel sprays. Fuel, 87(13-14), 2871-2885. doi:10.1016/j.fuel.2008.04.017PAYRI, R., GARCIA, J., SALVADOR, F., & GIMENO, J. (2005). Using spray momentum flux measurements to understand the influence of diesel nozzle geometry on spray characteristics. Fuel, 84(5), 551-561. doi:10.1016/j.fuel.2004.10.009Payri, R., Salvador, F. J., Gimeno, J., & Novella, R. (2011). Flow regime effects on non-cavitating injection nozzles over spray behavior. International Journal of Heat and Fluid Flow, 32(1), 273-284. doi:10.1016/j.ijheatfluidflow.2010.10.001Perumal, K., & Ganesan, R. (2015). CFD modeling for the estimation of pressure loss coefficients of pipe fittings: An undergraduate project. 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    Cements based on kaolinite waste

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    The cement industry involves high-energy consumption that generates high CO2 emissions into the atmosphere. Environmental concerns can be addressed by replacing parts of Portland cement clinkers with pozzolanic materials in mortars and concrete. Slag, fly ash and silica fume are materials considered for the planned replacement. Research studies on clay minerals, such as kaolinite, are being followed with special attention by the scientific community and the cement industry. It is well known that these minerals require an activation process to transform kaolinite (K) into metakaolinite (MK). MK is an amorphous material from the transformation of K with high pozzolanic activity, which is its capacity to react with the portlandite released during the hydration of Portland cement, generating compounds such as C–S–H gels and some aluminum-phase hydrates. One of the MK production methods is heat treatment controlled by kaolinite at temperatures in the range of 600–900°C. Different residues have been used (coal mining, paper sludge and waste from a drinking water treatment plant) activated at 600°C for 2h to elaborate blended cements. Due to their good behaviour as future eco-efficient additions, this research is a study by x-ray fluorescence (XRF), x-ray diffraction (XRD) and scanning electron microscopy (SEM) of their influence on the performances of blended cement mixtures (binary and ternary one), with substitutions of pozzolan ratio at 28 days of hydration. The porosity of pozzolanic cements decreases because of the formation of hydrated phases during pozzolanic reaction.the Spanish Ministry of the Economy and Competitiveness under coordinated projects BIA2015-65558C3-1-2-3R (MINECO/FEDER
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