1,784 research outputs found
Contributo da pesquisa qualitativa para a consolidação disciplinar dos estudos de tendências : processo, perspectivas e corpus
A abordagem qualitativa considera a sociedade constituÃda por
indivÃduos e grupos, que compartilham significações de acordo com
expectativas e prismas coletivos. Isto contribui positivamente para uma
visão crÃtica dos estudiosos da área de moda em relação ao fenômeno das
tendências, uma vez que o pesquisador investiga fatos, situações e
processos no cenário social que, interligados, possibilitam explanar sobre
determinado fenômeno examinado. A literatura destaca que coexistem
diversas perspectivas, epistemologias e ontologias na investigação
qualitativa. Destarte, este trabalho, de revisão bibliográfica, objetiva
apontar indÃcios para uma suficiente compreensão deste assunto, visto
que os autores da área dissertam uma multiplicidade de posicionamentos
paradigmáticos no contexto da pesquisa qualitativa e contemplam
diversas interpretações no decurso histórico.ABSTRACT: The qualitative approach considers society to be made up of
individuals and groups who share meanings according to expectations and
collective perspectives. It may contribute positively a critical view of
scholars and fashion professionals with regard to the phenomenon of the
trends. From this methodological design, the researcher investigates
processes, facts and situations in the social scene which, interconnected,
can explain the phenomenon analyzed. The literature points out that for
qualitative research several perspectives, epistemologies and ontologies
coexist. Thus, the overall objective of this work is to show indicative data
to a reasonable understanding of these issues, with no intention of
exausting them. The authors in this area present plenty of paradigmatic
positions within the qualitative research and conceive different meanings
over historical moments.info:eu-repo/semantics/publishedVersio
On top of commercial photovoltaics
The efficiency of single junction solar cells is intrinsically limited and high efficiency multi junctions are not cost effective yet. Now, semi transparent perovskite solar cells suggest that low cost multi junctions could be within reac
Two-scale composite finite element method for Dirichlet problems on complicated domains
In this paper, we define a new class of finite elements for the discretization of problems with Dirichlet boundary conditions. In contrast to standard finite elements, the minimal dimension of the approximation space is independent of the domain geometry and this is especially advantageous for problems on domains with complicated micro-structures. For the proposed finite element method we prove the optimal-order approximation (up to logarithmic terms) and convergence estimates valid also in the cases when the exact solution has a reduced regularity due to re-entering corners of the domain boundary. Numerical experiments confirm the theoretical results and show the potential of our proposed metho
Investigation of Band Tailing in Sputtered ZnO Al Thin Films Regarding Structural Properties and Impurities
Thin films of pure aluminum doped ZnO and with addition of nitrogen, oxygen and hydrogen have been prepared by magnetron sputtering. The spectral absorption coefficient close to the band gap energy has been determined by spectrophotometry and analyzed regarding band tailing and creation of defect bands. We found, that an improvement of Raman crystallinity under O2 rich growth conditions is not accompanied by a suppression of band tailing as expected. An additional absorption feature evolves for layers grown in N2 containing atmosphere. Doping with hydrogen attenuates sub band gap absorptio
Técnicas laboratoriais para isolamento de Campylobacter em material avÃcola.
Projeto/Plano de Ação: 03.08.06.004
Two-photon interference using background-free quantum frequency conversion of single photons from a semiconductor quantum dot
We show that quantum frequency conversion (QFC) can overcome the spectral
distinguishability common to inhomogeneously broadened solid-state quantum
emitters. QFC is implemented by combining single photons from an InAs quantum
dot (QD) at 980 nm with a 1550 nm pump laser in a periodically-poled lithium
niobate (PPLN) waveguide to generate photons at 600 nm with a
signal-to-background ratio exceeding 100:1. Photon correlation and two-photon
interference measurements confirm that both the single photon character and
wavepacket interference of individual QD states are preserved during frequency
conversion. Finally, we convert two spectrally separate QD transitions to the
same wavelength in a single PPLN waveguide and show that the resulting field
exhibits non-classical two-photon interference.Comment: Supercedes arXiv:1205.221
Greenhouse gas emissions mitigation in more sustainable agroecosystems in Cerrado.
In this work, we show that the transition to more sustainable rural production can mitigate greenhouse gas (GHG) emissions by agroecosystems without compromising revenues, particularly in the Cerrado region.(Embrapa Gado de Corte. Documentos, 216). Coordenador Roberto Giolo de Almeida. II SIGEE. DisponÃvel em: . Acesso em: 30 nov. 2016
Spatial multi-criteria decision analysis to predict suitability for African swine fever endemicity in Africa
Background
African swine fever (ASF) is endemic in several countries of Africa and may pose a risk to all pig producing areas on the continent. Official ASF reporting is often rare and there remains limited awareness of the continent-wide distribution of the disease.
In the absence of accurate ASF outbreak data and few quantitative studies on the epidemiology of the disease in Africa, we used spatial multi-criteria decision analysis (MCDA) to derive predictions of the continental distribution of suitability for ASF persistence in domestic pig populations as part of sylvatic or domestic transmission cycles. In order to incorporate the uncertainty in the relative importance of different criteria in defining suitability, we modelled decisions within the MCDA framework using a stochastic approach. The predictive performance of suitability estimates was assessed via a partial ROC analysis using ASF outbreak data reported to the OIE since 2005.
Results
Outputs from the spatial MCDA indicate that large areas of sub-Saharan Africa may be suitable for ASF persistence as part of either domestic or sylvatic transmission cycles. Areas with high suitability for pig to pig transmission (‘domestic cycles’) were estimated to occur throughout sub-Saharan Africa, whilst areas with high suitability for introduction from wildlife reservoirs (‘sylvatic cycles’) were found predominantly in East, Central and Southern Africa. Based on average AUC ratios from the partial ROC analysis, the predictive ability of suitability estimates for domestic cycles alone was considerably higher than suitability estimates for sylvatic cycles alone, or domestic and sylvatic cycles in combination.
Conclusions
This study provides the first standardised estimates of the distribution of suitability for ASF transmission associated with domestic and sylvatic cycles in Africa. We provide further evidence for the utility of knowledge-driven risk mapping in animal health, particularly in data-sparse environments.</p
3.3 Gigahertz Clocked Quantum Key Distribution System
A fibre-based quantum key distribution system operating up to a clock
frequency of 3.3GHz is presented. The system demonstrates significantly
increased key exchange rate potential and operates at a wavelength of 850nm.Comment: Presented at ECOC 05, Glasgow, UK, (September 2005
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