Three-dimensional instabilities in a discretely heated annular flow: onset of spatio-temporal complexity via defect dynamics

The transition to three-dimensional and unsteady flow in an annulus with a discrete heat source on the inner cylinder is studied numerically. For large applied heat flux through the heater (large Grashof number Gr), there is a strong wall plume originating at the heater that reaches the top and forms a large scale axisymmetric wavy structure along the top. For Gr approximate to 6 x 109, this wavy structure becomes unstable to three-dimensional instabilities with high azimuthal wavenumbers m similar to 30, influenced by mode competition within an Eckhaus band of wavenumbers. Coexisting with some of these steady three-dimensional states, solution branches with localized defects break parity and result in spatio-temporal dynamics. We have identified two such time dependent states. One is a limit cycle that while breaking spatial parity, retains spatio-temporal parity. The other branch corresponds to quasi-periodic states that have globally broken parity. (C) 2014 AIP Publishing LLC.Postprint (published version

Perovskite thin film synthesised from sputtered lead sulphide

CNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOIn the last few years, research on dye-sensitised devices has been focused on the development of solar cells, based on CH3NH3PbX3 (X = I-, Br-, Cl-) composites with perovskite structure. The deposition of perovskite thin films is usually carried out by solution-based processes using spincoating techniques that result in the production of high quality films. Solar cells made by this method exceed 20% efficiency, with the potential for use in large scale production through ink print or screen printing techniques. As an alternative route, perovskite thin films can be deposited through thermal evaporation. A new method is proposed to produce CH3NH3PbI3, based on a radio-frequency (rf) -sputtering technique that results in a high reproducibility of the films and is compatible with roll-toroll processes. We deposited thin films of lead-sulphide (PbS) and converted them into perovskite by placing the films in an iodine atmosphere, followed by dipping in a solution of methylammonium iodide (CH3NH3I). The conversions to PbI2 and CH3NH3PbI3 were confirmed by elemental analyses, absorption, and photoluminescence spectroscopy. Structural properties were revealed by X-ray diffraction and infrared and Raman spectroscopy.818CNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO554336/2010-3407887/2013-0165756/2014-4465423/2014-02012/10127-52013/26385-

Stacked Denoising Autoencoders and Transfer Learning for Immunogold Particles Detection and Recognition

In this paper we present a system for the detection of immunogold particles and a Transfer Learning (TL) framework for the recognition of these immunogold particles. Immunogold particles are part of a high-magnification method for the selective localization of biological molecules at the subcellular level only visible through Electron Microscopy. The number of immunogold particles in the cell walls allows the assessment of the differences in their compositions providing a tool to analise the quality of different plants. For its quantization one requires a laborious manual labeling (or annotation) of images containing hundreds of particles. The system that is proposed in this paper can leverage significantly the burden of this manual task. For particle detection we use a LoG filter coupled with a SDA. In order to improve the recognition, we also study the applicability of TL settings for immunogold recognition. TL reuses the learning model of a source problem on other datasets (target problems) containing particles of different sizes. The proposed system was developed to solve a particular problem on maize cells, namely to determine the composition of cell wall ingrowths in endosperm transfer cells. This novel dataset as well as the code for reproducing our experiments is made publicly available. We determined that the LoG detector alone attained more than 84\% of accuracy with the F-measure. Developing immunogold recognition with TL also provided superior performance when compared with the baseline models augmenting the accuracy rates by 10\%

Relación entre la actividad física de los adolescentes y la de madres/padres

Este estudio tiene como objetivo analizar la relación entre la AF de los padres y madres con la de sus hijas e hijos. Participaron en el estudio 1604 adolescentes (807 portugueses, 797 españoles). Para la recogida de datos sobre práctica de AF se utilizó un cuestionario para los adolescentes y otro para los padres y madres. El efecto de la AF de las madres y de los padres sobre la AF de sus hijas e hijos fue evaluado a través de regresión logística multinomial. Los adolescentes con progenitores físicamente activos practicaban semanalmente más veces AF no organizada (59.4% vs. 37.9%, p<0.001), organizada (39.6% vs. 22.7%, p<0.001) y durante más tiempo (24.8% vs. 17.0%, p=0.010) que los que tenían madre y padre poco activos. Los adolescentes con madres activas y padres poco activos (OR=1.8, 95% IC: 1.3-2.7, p=0.002), y los que tenían ambos activos (OR=2.1, 95% IC: 1.4-3.2, p<0.001) tenían mayor probabilidad de practicar AF no organizada. Tener el padre activo y la madre poco activa (OR=1.6, 95% IC: 1.1-2.1, p=0.024) y tener ambos activos (OR=1.6, 95% IC: 1.1-2.3, p=0.017) estaba asociado a una mayor probabilidad de práctica de AF organizada. El presente estudio demostró la existencia de una relación entre la AF de padres y madres con la AF de sus hijos e hijas.This study aimed to examine the relationship between the physical activity (PA) levels of parents and that showed by their children. A sample comprised of 1604 adolescents (807 Portuguese, 797 Spanish)participated in this study. For PA data collection it was used a questionnaire for parents and another one for their children. Multinomial logistic regression was used to examine the relationship between the PA levels of parents and that showed by their children. Adolescents with active parents practiced more often non-organized PA (59.4% vs. 37.9%, p<0.001), organized PA (39.6% vs. 22.7%, p<0.001) on a weekly basis, and during more time (24.8% vs. 17.0%, p=0.010) than those who had a mother and father less actives. Adolescents with active mothers and less active fathers (OR=1.8, 95% IC: 1.3-2.7, p=0.002), and those who had both active parents (OR=2.1, 95% IC: 1.4-3.2, p<0.001) were more likely to practice non-organized PA. To have active father and less active mother (OR=1.6, 95% IC: 1.1-2.1, p=0.024), and have both active parents (OR=1.6, 95% IC: 1.1- 2.3, p=0.017) were associated with a greater likelihood of practice of organized AF. These results highlight the relationship between parents PA participation and their children PA participation.Este estudo teve como objetivo analisar a relação entre os níveis de atividade física (AF) dos pais e os mostrados pelos respetivos filhos. Participaram no estudo 1604 adolescentes (807 portugueses, 797 espanhóis). Para a recolha de dados referente à AF recorreu-se à aplicação de um questionário para os pais e outro para os filhos. Foi utilizada uma regressão múltipla logística para averiguar a relação entre os níveis de AF dos pais e os mostrados pelos filhos. Adolescentes com pais ativos praticaram AF não organizada mais frequentemente (59,4% vs. 37,9%, p <0,001), AF organizada (39,6% vs. 22,7%, p <0,001) semanalmente e durante mais tempo (24,8% Versus 17,0%, p = 0,010) do que aqueles que tinham uma mãe e pai menos ativos. Adolescentes com mães ativas e pais menos ativos (OR = 1,8, IC 95%: 1,3-2,7, p = 0,002), e aqueles que tiveram ambos os pais ativos (OR = 2,1, IC 95%: 1,4-3,2, p <0,001) eram mais propensos a praticar AF não organizada. Aqueles que tinham pai ativo e mãe menos ativa (OR = 1,6, IC 95%: 1,1-2,1, p = 0,024), e ambos os pais ativos (OR = 1,6, IC 95%: 1,1-2,3, p = 0,017) foram associados a uma maior probabilidade de prática de AF organizada. Esses resultados destacam a relação entre a participação em AF dos pais e a participação de seus filhos em AF

Surface Energy Budget over the Pantanal Wetland During the dry Season

In this work, the diurnal cycle of components of the surfaceenergy budget (SEB) are computed to the Brazilian Pantanal wetlandduring the dry season (September 1999). The analyzed data were collectedduring the Interdisciplinary Pantanal Experiment (IPE-2) realized by INPEand UFMS. A very defined diurnal cycle is observed, suggesting that theavailable energy at surface is mainly employed in the evapotranspirationeven during the dry season.Neste trabalho os componentes do balanço de radiação e energiaà superfície são investigados para o Pantanal Sul Mato-Grossense. Osdados experimentais foram coletados por uma torre meteorológica durantea Campanha Interdisciplinar do Pantanal (IPE-2) em setembro de1999 realizada pelo INPE e UFMS

Male post‐breeding movements and stopover habitat selection of an endangered short‐distance migrant, the Little Bustard Tetrax tetrax

Migratory decisions, such as the selection of stopover sites, are critical for the success of post‐breeding migratory movements and subsequent survival. Recent advances in bio‐logging have revealed the stopover strategies of many long‐distance migrants, but far less attention has been given to short‐distance migrants. We investigated the stopover ecology of an endangered grassland bird, the Little Bustard Tetrax tetrax, a short‐distance migrant in Iberia. Using high‐resolution spatial GPS/GSM data, 27 male Little Bustards breeding in southern Portugal were tracked between 2009 and 2011. We studied post‐breeding movements using Dynamic Brownian Bridge models to identify the main stopover sites, and generalized linear mixed models to examine habitat selection in stopovers. During their post‐breeding movements, males were essentially nocturnal migrants, making frequent stopovers while maintaining a relatively fast pace to reach more productive agricultural post‐breeding areas. Stopovers occurred in most post‐breeding movements (83%) regardless of the total distance covered (average 64.3 km), and most stopovers (84%) lasted less than 24 h. Birds used mostly agricultural non‐irrigated and irrigated croplands as stopover sites and avoided other land uses and rugged terrain. There was a negative relationship between stopovers and the proximity to roads, but not to power lines. The high frequency of stopovers during post‐breeding movements, despite the short distances travelled, together with the nocturnal migratory behaviour of bustards, may impose additional risks to a bird mainly threatened by collision with power lines in non‐breeding areas. We also conclude that even for short‐distance migrants, habitat connectivity between breeding and post‐breeding areas is likely to be a key conservation concern.info:eu-repo/semantics/publishedVersio

Noncommutative field gas driven inflation

We investigate early time inflationary scenarios in an Universe filled with a dilute noncommutative bosonic gas at high temperature. A noncommutative bosonic gas is a gas composed of bosonic scalar field with noncommutative field space on a commutative spacetime. Such noncommutative field theories was recently introduced as a generalization of quantum mechanics on a noncommutative spacetime. As key features of these theories are Lorentz invariance violation and CPT violation. In the present study we use a noncommutative bosonic field theory that besides the noncommutative parameter $\theta$ shows up a further parameter $\sigma$. This parameter $\sigma$ controls the range of the noncommutativity and acts as a regulator for the theory. Both parameters play a key role in the modified dispersion relations of the noncommutative bosonic field, leading to possible striking consequences for phenomenology. In this work we obtain an equation of state $p=\omega(\sigma,\theta;\beta)\rho$ for the noncommutative bosonic gas relating pressure $p$ and energy density $\rho$, in the limit of high temperature. We analyse possible behaviours for this gas parameters $\sigma$, $\theta$ and $\beta$, so that $-1\leq\omega<-1/3$, which is the region where the Universe enters an accelerated phase.Comment: Reference added. Version to appear in Journal of Cosmology and Astroparticle Physics - JCA

The VISIR+ Project – Helping Contextualize Math in an Engineering Course

[EN]The long-term goal of engineering education is to prepare students to work as engineers. Being a practical profession, laboratories play a crucial role in illustrating concepts and principles as well as improving technical skills. In the last decades the use of online resources (simulators and remote labs) has been growing, either as a complementary and/or as an alternative way of developing experimental competences. In the scope of the VISIR+ Project, this work presents the first results of a didactical implementation using simultaneously the remote laboratory VISIR (Virtual Instrument Systems in Reality), simulation and calculus in a Math Course at the Federal University of Santa Catarina (UFSC). The preliminary results indicate that the use of several resources increases students’ performance, boosting their learning and competence development