Experimental energy performance assessment of a solar desiccant cooling system in Southern Europe climates

Solar desiccant cooling systems, SDEC, could be an effective alternative to conventional cooling systems, which mainly depend on electrical energy. The main objective of this work was to determine experimentally the seasonal coefficient of performance, SCOP, of a SDEC system composed of a desiccant wheel, an indirect evaporative cooler and a thermal solar system, to control indoor conditions in a research lab room. The dependence of coefficient of performance on outdoor air conditions and percentage of renewable energy used by the SDEC system were also analysed. Experimental tests were carried out for six weeks during spring and summer seasons in Martos, Spain. The experimental results showed that the SDEC system independently adjusted the temperature and humidity of the supply air. 75% of the energy consumed by this air handling system comes from renewable sources. A seasonal coefficient of performance of the SDEC system of 2 was obtained for the period analysed. It is shown that the higher the outdoor temperature, the higher instantaneous COPs is. These results suggest that the use of SDEC systems in hot climates, such as southern European climates, could contribute to achieve the EU's energy goals within the frame of Nearly Zero Energy Buildings

A multi‐scale approach to rural depopulation in Mexico

This paper aims to sketch rural population decline in Mexico. A comprehensive multi-scale documentation of Mexico's urban and rural fabric and its depopulation dynamics is undertaken. This paper does not identify the causes and effects of rural depopulation, but aims to detect its geographical presence in a manner which other approaches are unable to do. The granularity of rural depopulation is identified as manifested at four different scales: national, state, municipal, and local village scale. We use census data for the period 2000–2010. We relate rural depopulation to spatio-geographical features found in the literature; the relationship of depopulating territories with urban ones and the altitude range in which they are located. We find that proximity to and remoteness from urban areas as well as that of altitude do not follow the typical patterns often observed elsewhere. Unlike that shown in other countries, in Mexico, rural depopulation is manifested mostly in lower-lying areas and despite the fact that most of the country is at altitude. Rural depopulation and disappearance occur mainly in the areas of plains below 1,000 metres above sea level, regardless of the population density of the territories where they were located. Also, our multi-scaling approach has allowed us to identify not just at what scale the phenomenon of rural depopulation is observed, but also, to identify the areas in which the phenomenon is manifested regionally or locally. As we see, much of the phenomenon is concentrated in different areas to what national narratives suggest

First detection in Europe of the metallo-β-lactamase IMP-15 in clinical strains of Pseudomonas putida and Pseudomonas aeruginosa

AbstractIn a prospective study (2009–2011) in healthcare institutions from the Canary Islands (Spain), 6 out of 298 carbapenem non-susceptible Pseudomonas aeruginosa isolates produced a metallo-β-lactamase: four IMP-15, two VIM-2 (including one IMP-15-positive isolate) and one VIM-1. Multilocus sequence typing identified the single VIM-1-producing isolate as clone ST111 and two IMP-15-producing isolates as ST606, but, strikingly, bacterial re-identification revealed that the other three isolates (producing IMP-15 and/or VIM-2) were actually Pseudomonas putida. Further retrospective analysis revealed a very high prevalence (close to 50%) of carbapenem resistance in this environmental species. Hence, we report the simultaneous emergence in hospitals on the Canary Islands of P. putida and P. aeruginosa strains producing IMP-15, a metallo-β-lactamase not previously detected in Europe, and suggest an underestimated role of P. putida as a nosocomial reservoir of worrying transferable resistance determinants

Characterization of plasmid-mediated beta-lactamases in fecal colonizing patients in the hospital and community setting in Spain

Aim: Active surveillance of plasmid-mediated ß-lactamase-producing Enterobacteriaceae (PMBL-E) in fecal carriers in the hospital and in the community setting in a non-outbreak period of time. Methods: Patients were screened for carriage of Enterobacteriaceae resistant to expanded-spectrum cephalosporins and PMBL-E were characterized (extended-spectrum-ß-lactamase [ESBL], plasmid-mediated AmpC ß-lactamase [pAmpC], and carbapenemases) by PCR and sequencing. Results: The prevalence of ESBL and pAmpC carriers was 5.06% and 0.59%, respectively. Overall, CTX-M-like enzymes were the ESBL dominate enzymes (96.15%). The group CTX-M-9 was the most prevalent (81, 54%) [CTX-M-14 (74, 91.35%), CTX-M-9 (5, 6.17%), CTX-M-24 (1, 1.23%), and CTX-M-27 (1, 1.23%)] followed by the group CTX-M-1 (64, 42.67%) [CTX-M-15 (42, 65.63%), CTX-M-1 (13, 20.31%), CTX-M-32 (8, 12.5%), and CTX-M-3 (1, 1.56%)]. One CTX-M-10, one CTX-M-59, and three CTX-M-8 were also found. A very small representation of SHV or TEM ESBL enzymes was found (3.2% and 0.64%, respectively). pAmpC characterization revealed a predominance of CMY-2 (81.25%), followed by DHA-1 (18.75%). We did not detect the presence of carbapenemase producers. Conclusions: The prevalence of ESBL-producers from fecal carriers is stable in our area, but colonization by pAmpC producers has emerged recently as we have confirmed. Periodic active surveillance is useful to identify these human reservoirs and control the evolution of PMBL carriage in a community over time

El impacto de la presencia online en las cuentas de Twitter de las universidades vascas y navarras

Las Universidades han tenido que adaptarse a los nuevos modelos de comunicación surgidos en la época de Internet. Dentro de estos nuevos paradigmas las redes sociales han irrumpido y Twitter se ha establecido como una de las más importantes. El objetivo de esta investigación es demostrar que existe una relación entre la presencia online de una Universidad, definida por la cantidad de información disponible en Internet, y su cuenta en Twitter. Para ello se analizó la relación entre la presencia online y los perfiles oficiales de las cinco universidades del País Vasco y Navarra. Los resultados demostraron la existencia de una correlación significativa entre la presencia online de las instituciones y el número de seguidores de sus respectivas cuentas. En segundo lugar, esta investigación se planteó si Twitter puede servir para potenciar la presencia online de una Universidad. Por eso que se formuló una segunda hipótesis que buscaba analizar si tener varias cuentas en Twitter aumentaría la presencia online de las Universidades. Los hallazgos para esta segunda hipótesis demostraron una correlación muy significativa entre tener varios perfiles en Twitter y la presencia online de las Universidades. Así queda demostrada la importancia de la presencia online para las cuentas de Twitter y la relevancia de Twitter a la hora de potenciar la presencia online de los centros.The universities have needed to adapt to the new models of communication that the Internet era has brought. Within these new models the social media have appeared and Twitter has established itself as one of the most important social network sites. The purpose of the present study is to show whether the online presence defined by information available on Internet of a university, and its Twitter account are related. To test this idea, a correlation analysis between the online presence of the five Basque and Navarre universities and their official Twitter profiles was conducted. The results indicated a significant direct correlation between the online presence of the Institutions and the number of followers of each account respectively. Furthermore, a second hypothesis was formulated in order to confirm whether having several Twitter accounts would increase the online presence of these universities. A strong and statistically significant correlation between having several Twitter accounts and the increase of the online presence of these universities was found. These results demonstrate the importance of the online presence to the Twitter accounts and the relevance of Twitter to increase the online presence of the universities

Ru- and Ir-complex decorated periodic mesoporous organosilicas as sensitizers for artificial photosynthesis

A versatile and facile strategy based on an inverse electron demand Diels–Alder reaction between 5-norbornen-2-yltriethoxysilane and a tetrazine derivative has been established for the synthesis of a new triethoxysilane precursor containing dipyridylpyridazine units. Such a precursor has been incorporated into the mesostructure of an ethylene-bridged periodic mesoporous organosilica (PMO) material through a one-pot synthesis via a co-condensation method. Upon attachment of Ru- and Ir-complexes to the pendant N-chelating heterocyclic ligands, the resulting decorated PMOs have acted as photosensitizers in artificial photosynthetic systems. The deposition of Pt on these PMOs has allowed us to obtain efficient photocatalytic materials for the hydrogen evolution reaction as a result of electron transfer from the light harvesting Ru- and Ir-complexes to the supported Pt nanoparticles through methyl viologen as an electron relay. They have exhibited total turnover number values of 573 and 846, respectively, under visible light irradiation. The role played by each component and the stability of the photocatalytic systems have been discussed. The present approach paves the way to the synthesis of different materials with coordination sites capable of forming surface complexes to be applied as sensitizers and catalysts

Zn-Cr layered double hydroxides for photocatalytic transformation of CO2 under visible light irradiation: the effect of the metal ratio and interlayer anion

Carbon dioxide is the main gas responsible for the greenhouse effect. Over the last few years, the research focus of many studies has been to transform CO2 into valuable products (CO, HCOOH, HCHO, CH3OH and CH4), since it would contribute to mitigating global warming and environmental pollution. Layered double hydroxides (LDHs) are two-dimensional materials with high CO2 adsorption capacity and compositional flexibility with potential catalytic properties to be applied in CO2 reduction processes. Herein, Zn-Cr LDH-based materials with different metal ratio and interlayer anions, i.e., chloride (Cl−), graphene quantum dots (GQDs), sodium dodecyl sulfate (SDS) and sodium deoxycholate (SDC), have been prepared by a co-precipitation method and characterized by different techniques. The influence of the interlayer inorganic and organic anions and the metal ratio on the application of Zn-Cr LDHs as catalysts for the photocatalytic CO2 reduction reaction under visible light irradiation is unprecedentedly reported. The catalytic tests have been carried out with Ru(bpy)32+ as photosensitizer (PS) and triethanolamine as sacrificial electron donor (ED) at λ = 450 nm. All LDHs materials exhibited good photocatalytic activity towards CO. Among them, LDH3-SDC showed the best catalytic performance, achieving 10,977 µmol CO g−1 at 24 h under visible light irradiation with a CO selectivity of 88%. This study provides pertinent findings about the modified physicochemical features of Zn-Cr LDHs, such as particle size, surface area and the nature of the interlayer anion, and how they influence the catalytic activity in CO2 photoreduction