2,486 research outputs found
N-Relaxion: Large Field Excursions from a Few Site Relaxion Model
Relaxion models are an interesting new avenue to explain the radiative
stability of the Standard Model scalar sector. They require very large field
excursions, which are difficult to generate in a consistent UV completion and
to reconcile with the compact field space of the relaxion. We propose an N-site
model which naturally generates the large decay constant needed to address
these issues. Our model offers distinct advantages with respect to previous
proposals: the construction involves non-abelian fields, allowing for
controlled high energy behaviour and more model building possibilities, both in
particle physics and inflationary models, and also admits a continuum limit
when the number of sites is large, which may be interpreted as a warped extra
dimension.Comment: 7 pages, 2 figures; v2: version to appear in PR
The curse of technological race: the red queen effect
Economic prosperity is tied to scientific development, i.e., there is a strong correlation between science, technology and the wealth of nations. We collected data from scientific and technological production of 183 countries of the last thirty years (1974 to 2003) and applied a super-paramagnetic clustering technique on them, finding nations divided in three regimes, distinguished by the interactions between the agents of their National Systems of Innovation (NSI). The identification of these groups allows us to define the dynamical behavior of the thresholds, that grow exponentially and whose growth rate we have calculated. We show that for the period 1974-2003 the threshold between the immature and the developed NSIs increases by an annual rate of 6.6% (per capita). We identify clearly a "Red Queen Effect". Finally we show that the transitions between the regimes are discontinuous, represented by a structural breakthrough. Therefore, the prerequisite to move from regime I to regime II, and then to regime III are structural changes within NSIs.national systems of innovation; super-paramagnetic clustering technique; moving thresholds
Modeling economic growth fuelled by science and technology
This paper suggests a simulation model to investigate how science and technology fuel economic growth. This model is built upon a synthesis of technological capabilities represented by national innovation systems. This paper gathers data of papers and patents for 183 countries between 1999 and 2003, GDP and population for 2003. These data show a strong correlation between science, technology and income. Three simulation exercises are performed. Feeding our algorithm with data for population, patents and scientific papers, we obtain the world income distribution (R=0.99). These results support our conjecture on the role of science and technology as a source of the wealth of nations.simulation models; systems of innovation; economic growth
Matrices of science and technology interactions: implications for development
Scientific and other non-patent references (NPRs) in patents are important tools to analyze interactions between science and technology. This paper organizes a database with 514,894 USPTO patents granted globally in 1974, 1982, 1990, 1998 and 2006. There are 165,762 patents with at least one reference to science and engineering (S&E) literature, and there are 1,375,503 references. In 2006 there are 83 countries with USPTO patent citing S&E literature. Through a lexical analysis 71.1% of this S&E literature is classified by S&E fields. These data underscore the elaboration of global and national tri-dimensional matrices (by OST technological domains, ISI science and engineering fields and number of references). Descriptive statistics investigate how science and technology linkages differ over time across countries and across levels of development. This paper highlights how the existence (or not) of a pattern of structured growth differentiates mature and immature systems of innovation.science and technology linkages, stages of economic development, systems of innovation
First record of Alosa fallax (Lacépède, 1803) (Teleostei: Clupeiformes:Clupeidae) in the Azores Archipelago, Portugal (NE Atlantic)
Copyright © 2014 All rights reserved.This note reports the first record of Alosa fallax (Lacépède, 1803) in the Azores Archipelago (NE Atlantic, Portugal). Being an anadromous species, this occurrence is quite unexpected since there are no suitable breeding habitats for this species in these volcanic islands, isolated and river less. Although A. fallax is known to migrate offshore, it has never been previously reported in oceanic environments. We discuss this occurrence and theorize on the possibility of the species’ being found in Madeira, another Macaronesian Archipelago, albeit much older and closer to European coasts and thus more suitable to be crossed by A. fallax during their migration routes in pelagic environments. With this record, the number of Clupeid fishes for Azorean waters increases to two, the other being the well known and resident Sardina pilchardus
A tecnologia digital e a cultura da convergência na composição de uma típica enunciação estética em contexto de aprendizagem móvel
Caracterização de argamassas estabilizadas para revestimento
A argamassa estabilizada trata-se de uma tecnologia relativamente nova na construção civil, pois os aditivos presentes em sua composição permitem que a mesma se mantenha trabalhável por períodos de até 72 horas, sendo dosada em central e transportada em caminhões betoneiras, chegando preparada no canteiro de obras e prontas pra uso. Por ser recente no mercado da construção, a argamassa estabilizada não possui a mesma quantidade de estudos e pesquisas publicadas que os sistemas convencionais de argamassas (industrializadas ou realizadas em betoneira). A norma brasileira estabelece métodos para a determinação e avaliação das propriedades de argamassas para assentamento e revestimento em geral, mas a argamassa estabilizada, por possuir componentes diferentes de outros tipos de argamassa, possui características distintas, como tempo de cura maior, que devem ser levadas em consideração nos métodos de análise. Neste contexto, este trabalho visa à caracterização e análise de propriedades no estado fresco e endurecido de argamassas estabilizadas para revestimento segundo alguns requisitos da NBR 13281 (ABNT, 2005), através dos ensaios de consistência, de densidade (nos dois estados), de absorção por capilaridade, de tração na flexão e compressão axial, assim como também a avaliação dos níveis de retração, sendo as argamassas estabilizadas fornecidas por dois fabricantes diferentes da região de Porto Alegre e denominadas como “A” e “B”, pela ordem de coleta nas obras. Os resultados obtidos apresentaram níveis baixos e semelhantes de retração entre as argamassas analisadas, porém com grande diferença nos valores de resistência à tração na flexão. Em média, a argamassa “A” apresentou 31% da resistência à tração da argamassa “B”, ao mesmo tempo em que obteve apenas 17% da resistência à compressão. Nos ensaios de absorção por capilaridade, a argamassa “A” absorveu aproximadamente 50% a mais que a argamassa “B”, evidenciando a diferença entre os fornecedores
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