799 research outputs found
Impact of climate change on solar irradiation and variability over the Iberian Peninsula using regional climate models
As solar energy will be an increasingly important renewable energy source in the future years, the study of how climate change affects both temporal and spatial variability is very important. In this paper, we study future changes of the solar radiation resource in the Iberian Peninsula (IP) through a set of simulations from ESCENA project until mid-century. The evaluation of the simulations against observations indicates contrasting biases for the different regional climate models (RCMs) in terms of solar irradiation amount and its interannual variability. We propose a diagnostic for the quality of solar energy resource, in which the gridpoints are classified in four categories depending on the combination of solar irradiation amount and variability. The observed large percentage of points in the optimal category (high irradiation/low variability) in the IP is captured by the RCMs in general terms. The analysis of scenarios indicates a future increase in solar irradiation, although not all scenarios agree in the geographical distribution of this increase. In most projections, a shift is projected from the category with optimal resource quality towards the category with high irradiation/high variability, pointing to a certain quality loss in the solar resource. This result is not general, as a few scenarios show an opposite result. The exceptions are not linked to a particular GCM or emissions scenario. Finally, results from a first approximation to the issue of the ability of solar energy to cover power demand peaks in summer show important differences between regions of the IP. The spatially-averaged correlation of solar irradiation and summer surface temperatures for the whole IP is rather high, which is a positive result as the strong interconnections of the power grid within the IP could allow a distribution of solar power surpluses in certain regions for such high-temperature episodes
Impact of ocean–atmosphere coupling on future projection of Medicanes in the Mediterranean sea
Cyclones with tropical characteristics called medicanes (“Mediterranean Hur-ricanes”) eventually develop in the Mediterranean Sea. They have large harm-ful potential and a correct simulation of their evolution in climate projections is important for an adequate adaptation to climate change. Different studies suggest that ocean–atmosphere coupled models provide a better representation of medicanes, especially in terms of intensity and frequency. In this work, we use the regionally-coupled model ROM to study how air-sea interactions affect the evolution of medicanes in future climate projections. We find that under the RCP8.5 scenario our climate simulations show an overall frequency decrease which is more pronounced in the coupled than in the uncoupled con-figuration, whereas the intensity displays a different behaviour depending on the coupling. In the coupled run, the relative frequency of higher-intensity medicanes increases, but this is not found in the uncoupled simulation. Also, this study indicates that the coupled model simulates better the summer mini-mum in the occurrence of medicanes, avoiding the reproduction of unrealisti-cally intense events that can be found in summer in the uncoupled model
Análise de nutrientes em mudas de Nó-de-Cachorro (Heteropterys aphrodisiaca O. Mach.) cultivadas em diferentes substratos.
A espécie Heteropterys aphrodisíaca O. Mach (Nó -de-cachorro) é tida como planta medicinal de grande importância devido as suas atribuições curativas de enfermidades. Contudo, a parte fitotécnica ainda é pouco estudada. O objetivo do trabalho foi analisar os teores de sódio (Na), potássio (K), fósforo (P), magnésio (Mg), cálcio (Ca), manganês (Mn), ferro (Fe), nitrogênio total (NT) e proteína bruta (PB) nas folhas de mudas de Heteropterys aphrodisíaca O. Mach sob quatro tipos de misturas (M) contendo diferentes proporções de terra e areia e duas profundidades (P) de semeadura.bitstream/CPAP/55781/1/BP72.pdfBoletim de Pesquisa e Desenvolvimento Formato Eletrônico
Insights into the ceria-catalyzed ketonization reaction for biofuels applications
The ketonization of small organic acids is a valuable reaction for biorenewable applications. Ceria has long been used as a catalyst for this reaction; however, under both liquid and vapor phase conditions, it was found that given the right temperature regime of about 150-300 °C, cerium oxide, which was previously believed to be a stable catalyst for ketonization, can undergo bulk transformations. This result, along with other literature reports, suggest that the long held belief of two separate reaction pathways for either bulk or surface ketonization reactions are not required to explain the interaction of cerium oxide with organic acids. X-ray photon spectroscopy, scanning electron microscopy, and temperature programmed decomposition results supported the formation of metal acetates and explained the occurrence of cerium reduction as well as the formation of cerium oxide/acetate whiskers. After thermogravimetry/mass spectrometry and FT-IR experiments, a single reaction sequence is proposed that can be applied to either surface or bulk reactions with ceria
Batrachochytrium dendrobatidis Shows High Genetic Diversity and Ecological Niche Specificity among Haplotypes in the Maya Mountains of Belize
The amphibian pathogen Batrachochytrium dendrobatidis (Bd) has been implicated in amphibian declines around the globe. Although it has been found in most countries in Central America, its presence has never been assessed in Belize. We set out to determine the range, prevalence, and diversity of Bd using quantitative PCR (qPCR) and sequencing of a portion of the 5.8 s and ITS1-2 regions. Swabs were collected from 524 amphibians of at least 26 species in the protected areas of the Maya Mountains of Belize. We sequenced a subset of 72 samples that had tested positive for Bd by qPCR at least once; 30 samples were verified as Bd. Eight unique Bd haplotypes were identified in the Maya Mountains, five of which were previously undescribed. We identified unique ecological niches for the two most broadly distributed haplotypes. Combined with data showing differing virulence shown in different strains in other studies, the 5.8 s - ITS1-2 region diversity found in this study suggests that there may be substantial differences among populations or haplotypes. Future work should focus on whether specific haplotypes for other genomic regions and possibly pathogenicity can be associated with haplotypes at this locus, as well as the integration of molecular tools with other ecological tools to elucidate the ecology and pathogenicity of Bd
Repairing Socially Aggregated Ontologies Using Axiom Weakening
Ontologies represent principled, formalised descriptions of agents’ conceptualisations of a domain. For a community of agents, these descriptions may differ among agents. We propose an aggregative view of the integration of ontologies based on Judgement Aggregation (JA). Agents may vote on statements of the ontologies, and we aim at constructing a collective, integrated ontology, that reflects the individual conceptualisations as much as possible. As several results in JA show, many attractive and widely used aggregation procedures are prone to return inconsistent collective ontologies. We propose to solve the possible inconsistencies in the collective ontology by applying suitable weakenings of axioms that cause inconsistencies
The Borexino detector at the Laboratori Nazionali del Gran Sasso
Borexino, a large volume detector for low energy neutrino spectroscopy, is
currently running underground at the Laboratori Nazionali del Gran Sasso,
Italy. The main goal of the experiment is the real-time measurement of sub MeV
solar neutrinos, and particularly of the mono energetic (862 keV) Be7 electron
capture neutrinos, via neutrino-electron scattering in an ultra-pure liquid
scintillator. This paper is mostly devoted to the description of the detector
structure, the photomultipliers, the electronics, and the trigger and
calibration systems. The real performance of the detector, which always meets,
and sometimes exceeds, design expectations, is also shown. Some important
aspects of the Borexino project, i.e. the fluid handling plants, the
purification techniques and the filling procedures, are not covered in this
paper and are, or will be, published elsewhere (see Introduction and
Bibliography).Comment: 37 pages, 43 figures, to be submitted to NI
Intergroup fears and concerns among minority and majority groups: Implications for contact and attitudes
Aims:
Driven by the literature on pluralistic ignorance, our research investigates fear of appearing racist, being rejected, discriminated, and disinterest in intergroup contact as antecedents of contact and outgroup attitudes, focusing on attributional differences between the majority and minority group perspectives.
Methods:
Questionnaires were distributed in schools in Northern Italy. Participants were 400 Italian and 141 immigrant high-school students.
Results:
The results showed that lack of interest in contact was the strongest predictor of contact for the majority group. For the minority group, fear of rejection emerged as the strongest predictor. The majority group attributed the minority to avoid contact most strongly due to the fear that they would be rejected, and the minority group perceived it was due to the majority not being interested in contact.
Conclusion:
Our research contributes to understanding the divergent concerns majority and minority groups have in relation to intergroup contact, and discusses the importance of tackling these concerns
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