Nd:YAG laser scribed zinc oxide on semi-flexible copper foils

In this work, a novel approach to synthesise zinc oxide (ZnO) directly on flexible copper substrates is proposed. The produced samples show a foam-like morphology made of agglomerates of small ZnO particles when processed at laser energy density of 18.0 J/cm2. On the other hand, the samples processed at higher beam energy density, i.e. 33.2 J/cm2, resulted in a more granular morphology, with some ZnO particles dispersed over the sample’s surface. Raman spectroscopy measurements demonstrated that this method resulted in the formation of wurtzite-ZnO crystalline phase in all samples. Room temperature photoluminescence spectroscopy analysis revealed the presence of a broad visible band in the orange-red region dominating the spectra, with a small contribution from the near band edge emission in the UV spectral region. Decreasing the beam energy fluence from 33.2 to 18.0 J/cm2 resulted in samples with higher overall visible band intensity, in line with what was observed for their crystalline quality. Moreover, the shift of the broad band maxima towards longer wavelengths could be an indication of the possibility of tuning the visible emission according to the chosen laser processing conditions.publishe

A História da Alimentação: balizas historiográficas

Os M. pretenderam traçar um quadro da História da Alimentação, não como um novo ramo epistemológico da disciplina, mas como um campo em desenvolvimento de práticas e atividades especializadas, incluindo pesquisa, formação, publicações, associações, encontros acadêmicos, etc. Um breve relato das condições em que tal campo se assentou faz-se preceder de um panorama dos estudos de alimentação e temas correia tos, em geral, segundo cinco abardagens Ia biológica, a econômica, a social, a cultural e a filosófica!, assim como da identificação das contribuições mais relevantes da Antropologia, Arqueologia, Sociologia e Geografia. A fim de comentar a multiforme e volumosa bibliografia histórica, foi ela organizada segundo critérios morfológicos. A seguir, alguns tópicos importantes mereceram tratamento à parte: a fome, o alimento e o domínio religioso, as descobertas européias e a difusão mundial de alimentos, gosto e gastronomia. O artigo se encerra com um rápido balanço crítico da historiografia brasileira sobre o tema

Drosophila melanogaster larvae make nutritional choices that minimize developmental time

Organisms from slime moulds to humans carefully regulate their macronutrient intake to optimize a wide range of life history characters including survival, stress resistance, and reproductive success. However, life history characters often differ in their response to nutrition, forcing organisms to make foraging decisions while balancing the trade-offs between these effects. To date, we have a limited understanding of how the nutritional environment shapes the relationship between life history characters and foraging decisions. To gain insight into the problem, we used a geometric framework for nutrition to assess how the protein and carbohydrate content of the larval diet affected key life history traits in the fruit fly, Drosophila melanogaster. In no-choice assays, survival from egg to pupae, female and male body size, and ovariole number - a proxy for female fecundity - were maximized at the highest protein to carbohydrate (P:C) ratio (1.5:1). In contrast, development time was minimized at intermediate P:C ratios, around 1:2. Next, we subjected larvae to two-choice tests to determine how they regulated their protein and carbohydrate intake in relation to these life history traits. Our results show that larvae targeted their consumption to P:C ratios that minimized development time. Finally, we examined whether adult females also chose to lay their eggs in the P:C ratios that minimized developmental time. Using a three-choice assay, we found that adult females preferentially laid their eggs in food P:C ratios that were suboptimal for all larval life history traits. Our results demonstrate that D. melanogaster larvae make foraging decisions that trade-off developmental time with body size, ovariole number, and survival. In addition, adult females make oviposition decisions that do not appear to benefit the larvae. We propose that these decisions may reflect the living nature of the larval nutritional environment in rotting fruit. These studies illustrate the interaction between the nutritional environment, life history traits, and foraging choices in D. melanogaster, and lend insight into the ecology of their foraging decisions.Fundação Calouste Gulbenkian; Instituto Gulbenkian de Ciência

Response Surfaces

Data and scripts for generating the response surface

Simultaneous CVD synthesis of graphene-diamond hybrid films

An innovation is reported in the synthesis of a hybrid carbon structure resulting from the simultaneous growth of graphene and nanocrystalline diamond (NCD) by the microwave plasma chemical vapor deposition technique. This strategy allows to take advantage of the complementary electronic behavior of each carbon allotrope, a key feature in new nanostructured materials for electronics under the graphene/insulator all-carbon approach. The graphene-diamond hybrid structures were grown on copper and transferred to a glass substrate to be further characterized. Raman analysis puts in evidence the signature of both phases and the high crystallinity of the graphene layer, based on band intensity and width measurements. Raman mapping and SEM observations show a uniform distribution of the NCD clusters, confirmed by AFM/EFM measurements. Additionally, HRTEM analysis permitted to detail the diamond nanocrystalline structure, revealing a close link to the graphene layer on the basis of which a diamond on graphene nucleation mechanism is proposed. (C) 2015 Elsevier Ltd. All rights reserved

Egas Moniz (1874-1955): cultura e ciência Egas Moniz (1874-1955): culture and science

Por ocasião do sexagésimo aniversário da atribuição, em 1949, do prêmio Nobel da Medicina ou Fisiologia a Egas Moniz e a Walter Rudolf Hess, foram evocadas as circunstâncias que explicam a singular nobelização. Chama-se atenção para os traços biográficos de Egas Moniz, que são também os de muitos médicos da sua geração, asssim como dos pormenores que se prendem com o processo de nomeação e avaliação científica visando à candidatura ao prêmio Nobel. São também discutidos aspectos de ligação entre a cultura e a ciência, designadamente as controvérsias à volta do prêmio que lhe foi atribuído.<br>On the occasion of the sixtieth anniversary of the award in 1949, the Nobel Prize in Physiology or Medicine granted to Egas Moniz and Walter Rudolf Hess, the circumstances that explain the unique Nobel award require elucidation. Attention is drawn to the biographical traits of Egas Moniz, which are also those of many doctors of his generation, as well as the details which relate to the process of nomination and scientific appraisal to be eligible for the Nobel Prize. Aspects of the link between culture and science are also discussed, including the controversies surrounding the award conferred upon him