Estudio comparativo entre valores característicos experimentales y normativos de madera aserrada de pino silvestre

Estudio que analiza el comportamiento experimental de vigas de madera aserradas con el marcado por la normativa de caracterización

Reinforcement and repair of small sawn Pinus Sylvestris beams with carbon fiber

Refuerzo y reparación de vigas de madera aserrada con sistemas de materiales compuestos (fibra de carbono)-- ABSTRACT:This paper explores the behavior of wooden beams tested to bending up to fracture, and later repaired with bidirectional carbon fiber fabric of two grammage types, placed in one or two layers. In addition, beams reinforced with the same fabrics were tested to flexural strength until fracture in order to compare the results. For this purpose, 21 beams were tested to bending at 3 and 4 points; 13 of these beams did not have any reinforcement, 8 of them were repaired with carbon fiber reinforced polymer (CFRP) and later tested, and the other 8 beams were reinforced but were not submitted to any previous test. Results show that when the appropriate fabric strength, the repaired beams –previously collapsed– support higher loads than those that initially caused them to fracture

Iterative dual-metal and energy transfer catalysis enables stereodivergence in alkyne difunctionalization: Carboboration as case study

Stereochemically defined tetrasubstituted olefins are widespread structural elements of organic molecules and key intermediates in organic synthesis. However, flexible methods enabling stereodivergent access to E and Z isomers of fully substituted alkenes from a common precursor represent a significant challenge and are actively sought after in catalysis, especially those amenable to complex multifunctional molecules. Herein, we demonstrate that iterative dual-metal and energy transfer catalysis constitutes a unique platform for achieving stereodivergence in the difunctionalization of internal alkynes. The utility of this approach is showcased by the stereodivergent synthesis of both stereoisomers of tetrasubstituted β-boryl acrylates from internal alkynoates with excellent stereocontrol via sequential carboboration and photoisomerization. The reluctance of electron-deficient internal alkynes to undergo catalytic carboboration has been overcome through cooperative Cu/Pd-catalysis, whereas an Ir complex was identified as a versatile sensitizer that is able to photoisomerize the resulting sterically crowded alkenes. Mechanistic studies by means of quantum-chemical calculations, quenching experiments, and transient absorption spectroscopy have been applied to unveil the mechanism of both stepsPGC2018-098660−B-I00, Horizon2020 (ERC) No.648319, PID2019-106315RB-I00, PID2020-118593RB-C22

Análisis de campañas de comunicación social

Sisenes Jornades de Foment de la Investigació de la FCHS (Any 2000-2001

Momento Económico (17-18)

En este número Temas de hoy, 2/ Encuentro sobre la Deuda Externa de America Latina y el Caribe, México, Alonso Aguilar, 3/ Fernando Carmona, 5/ Heberto Castillo. 6/ Gantón Garcia Cantú, 7/ Pablo Gómez, 8/ Sergio Méndez Arceo, 9/ Carlos Tello, 11/ Mario J. Zepeda Martinez, 12/ Argentina, Enrique Garcia Vázquez, 16/ Adolfo Pérez Esquivel, 20/ Brasil, Frei Betto, 22/ Ecuador, Blanca Chancoso, 24/ El Salvador, Guillermo Ungo, 25/ República Dominicana, Juan Bosch, 27/ Venezuela, Miguel Ángel Capriles, 28/ Organismos Económicos Latinoamericanos, Homero L. Hernández, 3

La modernización del campo y la globalización económica

El presente libro incluye las ponencias presentadas en el del XIV Seminario de Economía Agrícola del Tercer Mundo, en el cual participan distinguidos especialistas nacionales y extranjeros, atentos a la dinámica y a la problemática actual de la producción primaria y el desarrollo rural de México y el mundo. El interés se centró en la elaboración de análisis críticos y propositivos en torno a los cambios ocurridos durante los últimos años en el sector rural mexicano a la luz del proceso de modernización y globalización económica en que está inmerso nuestro país. Los trabajos presentados en el Seminario muestran un consenso básico en torno a la importancia estratégica del sector agropecuario y rural para la construcción de un proyecto de desarrollo nacional sostenido, equilibrado y democrático

Twenty years of ground-based NDACC FTIR spectrometry at Izaña Observatory - overview and long-term comparison to other techniques

High-resolution Fourier transform infrared (FTIR) solar observations are particularly relevant for climate studies, as they allow atmospheric gaseous composition and multiple climate processes to be monitored in detail. In this context, the present paper provides an overview of 20 years of FTIR measurements taken in the framework of the NDACC (Network for the Detection of Atmospheric Composition Change) from 1999 to 2018 at the subtropical Izaña Observatory (IZO, Spain). Firstly, long-term instrumental performance is comprehensively assessed, corroborating the temporal stability and reliable instrumental characterization of the two FTIR spectrometers installed at IZO since 1999. Then, the time series of all trace gases contributing to NDACC at IZO are presented (i.e. C2H6, CH4, ClONO2, CO, HCl, HCN, H2CO, HF, HNO3, N2O, NO2, NO, O3, carbonyl sulfide (OCS), and water vapour isotopologues H162O, H182O, and HD16O), reviewing the major accomplishments drawn from these observations. In order to examine the quality and long-term consistency of the IZO FTIR observations, a comparison of those NDACC products for which other high-quality measurement techniques are available at IZO has been performed (i.e. CH4, CO, H2O, NO2, N2O, and O3). This quality assessment was carried out on different timescales to examine what temporal signals are captured by the FTIR records, and to what extent. After 20 years of operation, the IZO NDACC FTIR observations have been found to be very consistent and reliable over time, demonstrating great potential for climate research. Long-term NDACC FTIR data sets, such as IZO, are indispensable tools for the investigation of atmospheric composition trends, multi-year phenomena, and complex climate feedback processes, as well as for the validation of past and present space-based missions and chemistry climate models.The Izaña FTIR station has been supported by the German Bundesministerium für Wirtschaft und Energie (BMWi) via DLRunder grants 50EE1711A and by the Helmholtz Society via the research program ATMO. In addition, this research was funded by the European Research Council under FP7/(2007-2013)/ERC Grant agreement nº 256961 (project MUSICA), by the Deutsche Forschungsgemeinschaft for the project MOTIV (GeschaFTIRzeichen SCHN 1126/2-1), by the Ministerio de Economía y Competitividad from Spain through the projects CGL2012-37505 (project NOVIA) and CGL2016-80688-P (project INMENSE), and by EUMETSAT under its Fellowship Programme (project VALIASI)

Programa de captación de estudiantes de Bachillerato del distrito universitario de Salamanca (3ª Edición). Facultad de Filosofía – Universidad de Salamanca

Memoria ID-0267. Ayudas de la Universidad de Salamanca para la innovación docente, curso 2014-2015

Higher versus lower nut consumption and changes in cognitive performance over two years in a population at risk of cognitive decline: a cohort study

Background: Tree nuts and peanuts (henceforth, nuts) are nutrient-dense foods rich in neuroprotective components; thus, their consumption could benefit cognitive health. However, evidence to date is limited and inconsistent regarding the potential benefits of nuts for cognitive function. Objective: To prospectively evaluate the association between nut consumption and 2-y changes in cognitive performance in older adults at cognitive decline risk. Methods: A total of 6,630 participants aged 55 to 75 y (mean age 65.0±4.9 y, 48.4% women) with overweight/obesity and metabolic syndrome completed a validated semi-quantitative food frequency questionnaire and a comprehensive battery of neuropsychological tests at baseline and a 2-y follow-up. Composite cognitive scores were used to assess global, general, attention, and executive function domains. Nut consumption was categorized as Results: Nut consumption was positively associated with 2-y changes in general cognitive function (P-trend Conclusion: Frequent nut consumption was associated with a smaller decline in general cognitive performance over 2 y in older adults at risk of cognitive decline. Randomized clinical trials to verify our findings are warranted