Analísis vibracional de o-, m- y p- derivados del ácido benzoico

Tesis de la Universidad Complutense de Madrid, Facultad de Ciencias Químicas, 1985.Fac. de Ciencias QuímicasTRUEProQuestpu

Analísis vibracional de o-, m- y p- derivados del ácido benzoico

Tesis de la Universidad Complutense de Madrid, Facultad de Ciencias Químicas, 1985.Fac. de Ciencias QuímicasTRUEProQuestpu

Contribution sharing of a fuel mixture components to the fuel cell potencial of a direct alcohol fuel cell

The increasing worldwide demand for electricity impels to develop clean and renewable energy resources. In the field of portable power devices not only size and weight represent important aspects to take into account, but the fuel and its storage are also critical issues to consider. In this last sense, the direct methanol (MeOH) fuel cells (DMFC) play an important role as they can offer high power and energy density, low emissions, ambient operating conditions and fast and convenient refuelling

Comparative exergy analysis of direct alcohol fuel cells using fuel mixtures

Within the last years there has been increasing interest in direct liquid fuel cells as power sources for portable devices and, in the future, power plants for electric vehicles and other transport media as ships will join those applications. Methanol is considerably more convenient and easy to use than gaseous hydrogen and a considerable work is devoted to the development of direct methanol fuel cells. But ethanol has much lower toxicity and from an ecological viewpoint ethanol is exceptional among all other types of fuel as is the only chemical fuel in renewable supply. The aim of this study is to investigate the possibility of using direct alcohol fuel cells fed with alcohol mixtures. For this purpose, a comparative exergy analysis of a direct alcohol fuel cell fed with alcohol mixtures against the same fuel cell fed with single alcohols is performed. The exergetic efficiency and the exergy loss and destruction are calculated and compared in each case. When alcohol mixtures are fed to the fuel cell, the contribution of each fuel to the fuel cell performance is weighted attending to their relative proportion in the aqueous solution. The optimum alcohol composition for methanol/ethanol mixtures has been determined

Descripción de los niveles de Burnout en diferentes colectivos profesionales

El interés en la investigación del Burnout proviene del hecho de tratarse de un problema social que afecta a muchas personas. Los datos epidemiológicos sobre el síndrome hablan de un pro- blema de tal magnitud, que conlleva consecuencias personales y laborales negativas. Este hecho justifica por sí mismo que el desarrollo investigador haya crecido de manera considerable en es- tos últimos años. Si bien es cierto que existen diversos colectivos profesionales de riesgo de pa- decimiento del síndrome de Burnout, también lo es, que los niveles del mismo en sus diferentes dimensiones, suelen cambiar, e incluso la secuenciación en las mismas en la aparición del pro- blema, se puede ver alterada. El objetivo de este trabajo es describir comparativamente los nive- les de Burnout en cuatro muestras, una de población general y tres de profesionales, docentes, sanitarios y miembros de las Fuerzas Armadas

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Identification of recalcitrant stickies and their sources in newsprint production

Deposits from different sections of a newsprint paper mill, using 100% recovered paper, were analyzed following an analytical procedure based on scaning electron microscopy-electron dispersive X-ray and consecutive solvent extraction steps with Fourier-transform infrared spectroscopy (FTIR) analyses of the different fractions. Polyvinyl acetate, polyacrylates, styrene butadiene rubber, and derivatives of fatty acids/resin acids are the main stickies-related components identified in the deposits. The removal efficiency of these contaminants along the deinking line was studied by determining the composition of the dichloromethane extractives in the pulp by FTIR analyses. Although the total stickies content is reduced considerably during the process, some compounds, which are found in the deposits, are not removed selectively in the process, indicating their recalcitrant nature. FTIR analyses of unusable materials coming with the raw material (mainly board and mixed office waste) have demonstrated that these materials are one of the main sources of these types of recalcitrant stickies

Structure of polyfurane/perchlorate doped films by FTIR spectroscopy: effect of the synthesis conditions

The structure of stable polyfurane films doped with perchlorate anions (PFu/ClO4), electrogenerated at constant deposition overpotential, has been studied by FTIR spectroscopy. Electropolymerization overpotential, and monomer/electrolyte concentration ratio were the variables analyzed in this study as a mean of determining the synthesis conditions that would best produce more aromatic polymers (which would imply a larger extended ir-conjugated system). The spectra revealed a clear influence of both variables on the films generated, and although ring opening was detected, justified by the existence of aliphatic CH, OH, and C=O stretching vibrations, the spectra of these electroactive films showed higher aromaticity than had been previously reported by others authors. To study the aromaticity level and ring rupture of the PFu/ClO4 films, the experimental profile of the 1829-1345 cm"1 FTIR region was fitted to theoretical function, and the resulting three bands were assigned and analyzed as a function of the synthesis conditions.Sin financiación1.711 JCR (2000) Q1, 6/69 Polymer ScienceUE

Thermal stability of polyfuran/pechlorate doped films

Thermogravimetry, Fourier transform infrarred spectroscopy and scanning electron microscopy were performed on polyfuran films to assess thermal stability. The influence of temperature on the structure and morphology of doped polyfuran conducting films was discussed. Thermal degradation began around 95°C, although aromaticity, structure and ordered nodular morphology in the growth face and the honeycomb appearance in the cross-section were partially conserved until about 210°C.DGES (PB97-0271)0.853 JCR (1999) Q2, 27/70 Polymer scienceUE

Aula abierta

Resumen tomado de la publicación. La fecha, 2008, consta en la cub. de la revista, en la cabecera de los artículos consta por error, 2007El interés en la investigación del Burnout proviene del hecho de tratarse de un problema social que afecta a muchas personas. Los datos epidemiológicos sobre el síndrome hablan de un problema de tal magnitud, que conlleva consecuencias personales y laborales negativas. Este hecho justifica por sí mismo que el desarrollo investigador haya crecido de manera considerable en estos últimos años. Si bien es cierto que existen diversos colectivos profesionales de riesgo de padecimiento del síndrome de Burnout, también lo es, que los niveles del mismo en sus diferentes dimensiones, suelen cambiar, e incluso la secuenciación en las mismas en la aparición del problema, se puede ver alterada. El objetivo de este trabajo es decir comparativamente los niveles de Burnout en cuatro muestras, una de población general y tres profesionales, docentes, sanitarios y miembros de las Fuerzas Armadas.Asturias (Comunidad Autónoma)Universidad de Oviedo. Facultad de Ciencias de la Educación; Calle Aniceto Sela s. n.; 33005 Oviedo; Tel. +34985103215; Fax +34985103214;ES