551 research outputs found
Lecciones aprendidas de una instalación solar fotovoltaica para uso familiar en edificio multivivienda en un proceso de compra colectiva
CIES2020 - XVII Congresso Ibérico e XIII Congresso Ibero-americano de Energia SolarRESUMEN: La instalación de energía solar fotovoltaica en edificios plurifamiliares existentes, ya sea en instalaciones de autoconsumo compartido o individual se enfrenta a barreras legales, técnicas y de gestión de las decisiones en comunidades de propietarios. En base a la experiencia de una instalación realizada para uso individual en un edificio en el año 2018, el artículo analiza con detalle las principales barreras y propone acciones que permitan impulsar instalaciones en comunidades de propietarios. La monitorización detallada durante el primer año de operación ha permitido conocer que el nivel de autoconsumo es del 36% y que la instalación podría amortizarse hasta en 9 años. El proceso descrito se enmarca en una iniciativa de compra colectiva de instalaciones solares fotovoltaicas “llave en mano” que reduce las barreras al desconocimiento técnico que pudieran tener los ciudadanos. Si como sociedad queremos que las cubiertas de los bloques de viviendas puedan contribuir a la mitigación del cambio climático, es necesaria una labor de concienciación que minimice las barreras de gestión en las comunidades de propietarios.ABSTRACT: The installation of solar photovoltaic systems in existing multifamily buildings, for individual or shared generation, face a set of barriers going from legal and technical aspects to the ones related with how decisions are taken in these buildings between dwelling’s owners. Based on a real experience of one photovoltaic system for individual use in a multifamily building in 2018, the current paper analyzes the main barriers and proposes actions to push photovoltaics in multifamily buildings. The detailed monitoring of the installation in the first operative year shows that the supply cover factor is 36% and the investment could be recovered within up to 9 years. The process was done in the framework of a collective initiative to launch up top 100 turnkey photovoltaic systems showing how this contributed to reduce technical unknowns of the citizens. If the society wants that photovoltaics in multifamily buildings contribute to mitigate climate change, an awareness work is necessary to minimize the barriers that community of owners can pose to individual proposals.info:eu-repo/semantics/publishedVersio
The problem with online data collection: predicting invalid responding in undergraduate samples
The popularity of online research is increasing but the validity of the results obtained is not yet clear. The purpose of this study was to examine the factors that influence the validity of computerized data collection in an undergraduate sample. Participants were 99 university students randomly assigned to one of three data collection conditions: online survey platform, in-person computerized survey platform, and in-person pencil-and-paper survey. Results from statistical analyses suggest self-reported inattention symptoms, exposure to more stressors, and computerized platforms predict more invalid responding. In contrast, personality, self-reported impulsivity symptoms, and shorter completion times do not predict invalid responding. Overall, more than half of the participants failed at least one validity check and 11% failed three or more validity checks. Researchers, particularly those working with undergraduate samples, should consider implementing procedures to ensure the data collected are valid
Resolución numérica de flujos laminares con estructura tridimensional axialsimétrica. Análisis de diferentes situaciones
En el presente trabajo se implementa un algoritmo numérico basado en técnicas de diferencias finitas del tipo SIMPLE (Semi-Implicit Method for Pressure Linked Equations) para la resolución de las ecuaciones de conservación de la masa, de la cantidad de movimiento y de la energía, formuladas en coordenadas cilíndricas y para situaciones tridimensionales axialsimétricas, pudiéndose considerar regímenes permanentes y transitorios. El estudio se centra en el análisis de flujos laminares de fluidos newtonianos. En la formulación de las ecuaciones de cantidad de movimiento se han considerado, asumiendo la hipótesis de Boussinesq, los términos de fuerzas másicas; ello permite considerar casos de convección forzada, natural y naturallforzada. Para la validación del software se han resuelto situaciones con solución analítica conocida y casos para los que existen resultados experimentales y/o numéricos en la bibliografía. Se presentan diferentes resultados ilustrativos de las prestaciones de la simulación implementada y se hace referencia a posibles aplicaciones técnicas de la misma.Peer Reviewe
Hemangioendotelioma multicéntrico de muñeca
Se presenta el caso de un hemangioendotelioma multicéntrico grado I localizado
en el extremo distal del cúbito y en varios huesos del carpo en un varón de 57 años como hallazgo
casual en un estudio radiográfico realizado tras un traumatismo de muñeca. El paciente fue
tratado mediante resección amplia del extremo distal del cúbito y de los huesos del carpo afectos
(ganchoso, piramidal y pisiforme) y artrodesis radiocarpiana con injerto autólogo tricortical de
cresta ilíaca. Tras un seguimiento de 24 meses el paciente está asintomático y no presenta recidivas
locales ni metástasis a distancia.A case of multicentric hemangioendothelioma located at the distal ulnar and different
carpal bones was found in a 57-year-old man after a Rx control because a wrist trauma. The
patient was treated by wide resection of distal ulnar and the affected carpal bones. Fusion of the
radiocarpal joint was performed using tricortical autologous bone graft taken from the iliac crest.
After 24-month follow-up, the patient was asymptomatic without local recurrence or metastasis
A widespread family of phage-inducible chromosomal islands only steals bacteriophage tails to spread in nature
Phage satellites are genetic elements that couple their life cycle to that of helper phages they parasitize, interfering with phage packaging through the production of small capsids, where only satellites are packaged. So far, in all analyzed systems, the satellite-sized capsids are composed of phage proteins. Here, we report that a family of phage-inducible chromosomal islands (PICIs), a type of satellites, encodes all the proteins required for both the production of small-sized capsids and the exclusive packaging of the PICIs into these capsids. Therefore, this new family, named capsid-forming PICIs (cf-PICIs), only requires phage tails to generate PICI particles. Remarkably, the representative cf-PICIs are produced with no cost from their helper phages, suggesting that the relationship between these elements is not parasitic. Finally, our phylogenomic studies indicate that cf-PICIs are present both in gram-positive and gram-negative bacteria and have evolved at least three times independently to spread in nature
The dynamic trophic niche of an island bird of prey
Optimal foraging theory predicts an inverse relationship between the availability of preferred prey and niche width in animals. Moreover, when individuals within a population have identical prey preferences and preferred prey is scarce, a nested pattern of trophic niche is expected if opportunistic and selective individuals can be identified. Here, we examined intraspecific variation in the trophic niche of a resident population of striated caracara (Phalcoboenus australis) on Isla de los Estados (Staten Island), Argentina, using pellet and stable isotope analyses. While this raptor specializes on seabird prey, we assessed this population's potential to forage on terrestrial prey, especially invasive herbivores as carrion, when seabirds are less accessible. We found that the isotopic niche of this species varies with season, age, breeding status, and, to a lesser extent, year. Our results were in general consistent with classic predictions of the optimal foraging theory, but we also explore other possible explanations for the observed pattern. Isotopic niche was broader for groups identified a priori as opportunistic (i.e., nonbreeding adults during the breeding season and the whole population during the nonbreeding season) than it was for individuals identified a priori as selective. Results suggested that terrestrial input was relatively low, and invasive mammals accounted for no more than 5% of the input. The seasonal pulse of rockhopper penguins likely interacts with caracara's reproductive status by constraining the spatial scale on which individuals forage. Niche expansion in spatially flexible individuals did not reflect an increase in terrestrial prey input; rather, it may be driven by a greater variation in the types of marine prey items consumed.Fil: Balza, Ulises. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Lois, Nicolás Alejandro. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ecología, Genética y Evolución; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; ArgentinaFil: Polito, Michael J.. State University of Louisiana; Estados UnidosFil: Pütz, Klemens. Antarctic Research Trust; AlemaniaFil: Salom, Amira. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Raya Rey, Andrea Nélida. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentina. Wildlife Conservation Society; Estados Unidos. Universidad Nacional de Tierra del Fuego, Antártida e Islas del Atlántico Sur. Instituto de Ciencias Polares, Ambientales y Recursos Naturales; Argentin
Intravitreal bevacizumab (Avastin) for choroidal metastasis secondary to breast carcinoma: short-term follow-up
Uveal metastases are the most common intraocular
malignancy. The most common primary sites of cancer
are from the breast (47%) and lung (21%).1
The treatment for choroidal metastasis depends on
many factors including location, multiplicity, and activity
of each tumour.1
Bevacizumab (Avastins) is a full-length humanized
murine monoclonal antibody against the VEGF molecule,
and inhibits angiogenesis and tumour growth.2
In this report, we describe the effect of a single
intravitreal injection of bevacizumab (4 mg) in a
patient with choroidal metastasis secondary to breast
cancerMedicin
A Bridging bis-Allyl Titanium Complex: Mechanistic Insights into the Electronic Structure and Reactivity
Treatment of the dinuclear compound [{Ti(η5-C5Me5)Cl2}2(μ-O)] with allylmagnesium chloride provides the formation of the allyltitanium(III) derivative [{Ti(η5-C5Me5)(μ-C3H5)}2(μ-O)] (1), structurally identified by single-crystal X-ray analysis. Density functional theory (DFT) calculations confirm that the electronic structure of 1 is a singlet state, and the molecular orbital analysis, along with the short Ti −Ti distance, reveal the presence of a metal −metal single bond between the two Ti(III) centers. Complex 1 reacts rapidly with organic azides, RN3 (R = Ph, SiMe3), to yield the allyl μ-imido derivatives [{Ti(η5-C5Me5)(CH2CH=CH2)}2(μ-NR)(μ-O)] [R = Ph(2), SiMe3(3)] along with molecular nitrogen release. Reaction of 2 and 3 with H2 leads to the μ-imido propyl species [{Ti(η5-C5Me5)(CH2CH2CH3)}2(μ-NR)(μ-O)] [R = Ph(4), SiMe3(5)]. Theoretical calculations were used to gain insight into the hydrogenation mechanism of complex 3 and rationalize the lower reactivity of 2. Initially, the μ-imido bridging group in these complexes activates the H2 molecule via addition to the Ti −N bonds. Subsequently, the titanium hydride intermediates induce a change in hapticity of the allyl ligands, and the nucleophilic attack of the hydride to the allyl groups leads to metallacyclopropane intermediates. Finally, the proton transfer from the amido group to the metallacyclopropane moieties affords the propyl complexes 4 and 5.Ministerio de Ciencia, Innovación y Universidades
Universidad de Alcalá
Generalitat de Cataluny
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