Linear polarization of rapidly rotating ultracool dwarfs

Aims. We aim at studying the near infrared linear polarization signal of rapidly rotating ultracool dwarfs with spectral types ranging from M7 through T2 and projected rotational velocities vsini >= 30 km s^{-1}. All these dwarfs are believed to have dusty atmospheres and oblate shapes, an appropriate scenario to produce measurable linear polarization of the continuum light.\\ Methods. Linear polarimetric images were collected in the J-band for a sample of 18 fast-rotating ultracool dwarfs, five of which were also observed in the Z-band using the LIRIS spectrograph on the Cassegrain focus of the 4.2-m William Herschel Telescope. The measured median uncertainty in the linear polarization degree is +/-0.13% for our sample, which allowed us to detect polarization signatures above ~0.39% with a confidence of >=3\sigma.\\ Results. About 40+/-15% of the sample is linearly polarized in the Z- and J-bands. All positive detections have linear polarization degrees ranging from 0.4% to 0.8% in both filters independently of spectral type and spectroscopic rotational velocity. However, simple statistics point at the fastest rotators (vsini >=60 km s^{-1}) having a larger fraction of positive detections and a larger averaged linear polarization degree than the moderately rotating dwarfs (vsini=30--60 km s^{-1}). Our data suggest little linear polarimetric variability on short time scales (i.e., observations separated by a few ten rotation periods), and significant variability on long time scales (i.e., hundred to thousand rotation cycles), supporting the presence of "long-term weather" in ultracool dwarf atmospheres.Comment: 12 pages, 7 figures, recommended for publication in Astronomy and Astrophysic

Neutron diffusion equation solution using finite element method

Este trabalho apresenta a implementação da difusão neutrônica no seio do programa MEF usando como dados de entrada, as seções de choque homogenizadas produzidas pelo programa HAMMER. Esta implementação resgata a possibilidade de se fazer o cálculo de difusão neutrônica utilizando-se o método dos elementos finitos, tarefa já realizada anteriormente no IEN[2]. A esta implementação, acrescenta-se o cálculo de erro do fluxo neutrônico e se redefine a discretização, baseada neste erro, utilizando-se a remalhagem adaptativa[6] Este acréscimo permite homogeneizar o erro do cálculo do fluxo em todo o domínio tornando-se um programa moderno e um bom substituto ao programa CITATION. Apesar da utilização do método de potência, considerado um método de convergência lenta, para a solução do problema especial de autovalor, os resultados tem mostrado que isto não é uma limitação para a obtenção do fluxo neutrônico mesmo quando se utilizam malhas com mais de 10.000 elementos finitos. Neste trabalho, apresenta-se inicialmente a formulação variacional do problema de difusão neutrônica, a discretização em elementos finitos e finalmente a solução de vários exemplos de difusão neutrônica limitados a dois grupos de energia com várias regiões

Improving classification based on physical surface tension-neural net for the prediction of psychosocial-risk level in public school teachers

Background. Psychosocial risks, also present in educational processes, are stress factors particularly critical in state-schools, affecting the efficacy, stress, and job satisfaction of the teachers. This study proposes an intelligent algorithm to improve the prediction of psychosocial risk, as a tool for the generation of health and risk prevention assistance programs.Methods. The proposed approach, Physical Surface Tension-Neural Net (PST-NN), applied the theory of superficial tension in liquids to an artificial neural network (ANN), in order to model four risk levels (low, medium, high and very high psychosocial risk). The model was trained and tested using the results of tests for measurement of the psychosocial risk levels of 5,443 teachers. Psychosocial, and also physiological and musculoskeletal symptoms, factors were included as inputs of the model. The classification efficiency of the PST-NN approach was evaluated by using the sensitivity, specificity, accuracy and ROC curve metrics, and compared against other techniques as the Decision Tree model, Naive Bayes, ANN, Support Vector Machines, Robust Linear Regression and the Logistic Regression Model.Results. The modification of the ANN model, by the adaptation of a layer that includes concepts related to the theory of physical surface tension, improved the separation of the subjects according to the risk level group, as a function of the mass and perimeter outputs. Indeed, the PST-NN model showed better performance to classify psychosocial risk level on state-school teachers than the linear, probabilistic and logistic models included in this study, obtaining an average accuracy value of 97.31%.Conclusions. The introduction of physical models, such as the physical surface tension, can improve the classification performance of ANN. Particularly, the PST-NN model can be used to predict and classify psychosocial risk levels among state-school teachers at work. This model could help to early identification of psychosocial risk and to the development of programThe authors received financial support from the "Convocatoria Nacional para el Apoyo al Desarrollo de Tesis de Posgrado o de Trabajos Finales de Especialidades en el area de la Salud de la Universidad Nacional de Colombia 2017-2018'' via Resolution 21 of december 2017 from Vicerectoria of Investigaciones, who selected the proposal research: "Sistema de clasificacion basado en tecnicas inteligentes para identificar el grado de riesgo psicosocial en docentes de educacion basica primaria y secundaria en colegios publicos de Colombia'', with identification number Hermes 40976 and Quipu code 201010016754. The authors also received financial support from the "Universidad de San Buenaventura-Cali-Facultad de Ingenieria-Nuevas tecnologias trabajo y gestion''. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

Diseño de un sistema electrónico de sensor cromático para la selección grano de café

En el presente proyecto, se desarrolló un sistema de un sensor monocromático tsc-3200 para la clasificación de frutos de café dependiendo de su estado si está maduro o verde; para la descripción del color de un fruto de café se extrajo un patrón de estado. Con el proyecto, se implementará la reducción de paso de grano de café en estado verde, ya que cuando está el producto final maduro, sea de total agrado para el consumidor. La máquina cuenta con su debida seguridad industrial y técnica para el proceso de clasificar el grano de café con lo cual es utilizado un sensor cromático el cual toma la decisión si es verde lo expulsa inmediatamente para no perder la calidad al producto final y si el grano es rojo sigue al siguiente proceso

AS MADEIRAS NA BAHIA ATLÂNTICA COLONIAL: USOS E SABERES (1780-1808)

A madeira no período pré-industrial ocupava um lugar, com os riscos da comparação, que hoje é do aço. Com a fibra lenhosa era possível produzir desde utensílios domésticos até grandes embarcações, além das mais diversas obras públicas e particulares

A BOTÂNICA E AS MEMÓRIAS CIENTÍFICAS NA BAHIA ATLÂNTICA COLONIAL (1768-1808)

Esse trabalho buscou identificar padrões nas memórias científicas produzidas entre o final do século XVIII e início do século XIX, período no qual recortamos um total de (07) sete dessas produções na Bahia. O período escolhido coincide com o processo de institucionalização da filosofia natural portuguesa, bem como as repercussões do iluminismo na monarquia que trouxe maior racionalidade à administração

Source identification and global implications of black carbon

Black carbon (BC) is one of the short-lived air pollutants that contributes significantly to aerosol radiative forcing and global climate change. It is emitted by the incomplete combustion of fossil fuels, biofuels, and biomass. Urban environments are quite complex and thus, the use of mobile jointly with fixed monitoring provides a better understanding of the dynamics of BC distribution in such areas. The present study addresses the measurement of BC concentration using real-time mobile and ambient monitoring in Barranquilla, an industrialized urban area of the Colombian Caribbean. A microaethalometer (MA200) and an aethalometer (AE33) were used for measuring the BC concentration. The absorption Ångström exponent (AAE) values were determined for the study area, for identifying the BC emission sources. The results of the ambient sampling show that vehicle traffic emissions prevail; however, the influence of biomass burning was also observed. The mean ambient BC concentration was found to be 1.04 ± 1.03 μg/m3 and varied between 0.5 and 4.0 μg/m3. From the mobile measurements obtained in real traffic conditions on the road, a much higher average value of 16.1 ± 16.5 μg/m3 was measured. Many parts of the city showed BC concentrations higher than 20 μg/m3. The spatial distribution of BC concentration shows that vehicle emissions and traffic jams, a consequence of road and transport infrastructure, are the factors that most affect the BC concentration. A comparison of results obtained from two aethalometers indicates that the concentrations measured by MA200 are 9% lower than those measured by AE33. The AAE obtained was found to vary between 1.1 and 1.6, indicating vehicular emissions as the most crucial source. In addition, it was observed that the BC concentration on working days was 2.5 times higher than on the weekends in the case of mobile monitoring and 1.5 times higher in the case of ambient monitoring

Acute Physiological and Metabolic responses for 40-minutes of Samba Dance

Dance is an enjoyable health-promoting physical activity that many people worldwide incorporate into their lifestyles today. Therefore, dance improves your heart health, overall muscle strength, balance, and coordination, and reduces depression. We aim to gain insights into the effects of samba dance on the cardiorespiratory and metabolic response during an acute session of this dance style for 40-minutes. The study was carried out on 20 female samba dancers. All of them performed two procedures: (1) a cardiopulmonary exercise test on a treadmill for physical fitness aptitude verification and (2) a 40-minutes of samba dancing monitored by analysis of expired gases. The results were: At peak exercise: oxygen uptake (VO2) =32.7 mL.kg-1.min-1; heart rate (HR) =183 bpm; the pulse of oxygen (PO2) =10.9 mL.HR-1, energy expenditure (EE) = 9.9 kcal.min-1and metabolic equivalent (METs)=13.5.Overall, each session of the dance of 40-minutes was performed at a mean VO2 of 22.8 mL.kg-1.min-1 (70%VO2max), heart rate of 162 bpm (89%HRmax), energy expenditure (EE) of 6.5 kcal.min-1 (66%max), metabolic equivalent (METs) of 6.3 (62%max), and the rate of perceived exertion (RPE) of 11.8/20. In conclusion: The findings of the current investigation might suggest that the moderate and vigorous-intensity of the exercise verified in an acute samba dance session is enough to induce a chronic training effect recommended by the criteria established by the American College of Sports Medicine for improving cardiorespiratory fitness. This information may lead to a better understanding of the energy expenditure of samba dance and add to the compendium of physical activity.

O caso do eculizumabe: judicialização e compras pelo Ministério da Saúde

OBJECTIVES: This study examined the purchases of eculizumab, a high-cost monoclonal antibody used in the treatment of rare diseases by Brazilian federal agencies, in terms of purchased quantities, expenditures, and prices. METHODS: Eculizumab purchases made between March 2007 and December 2018 were analyzed, using secondary data extracted from the Federal Government Purchasing System (SIASG in Portuguese). The following aspects were assessed: number of purchases, purchased quantities, number of daily doses defined per 1,000 inhabitants per year, annual expenditures, and prices. The prices were adjusted by the National Broad Consumer Price Index for December 2018. Linear regression was used for trend analysis. RESULTS: All acquisitions by federal agencies were made by the Brazilian Ministry of Health. The purchases began in 2009 with tender waiver to comply with legal demand. There was an increasing trend in the number of purchases and quantities acquired over time. Two hundred and eighty-three purchases were made, totaling 116,792 units purchased, 28.2% of them in 2018. The adjusted total expenses summed more than R$2.44 billion. After market approval by the Brazilian Health Regulatory Agency, the weighted average price fell approximately 35$ 2,44 bilhões. Após a aprovação do registro pela Agência Nacional de Vigilância Sanitária, o preço médio ponderado caiu aproximadamente 35%, para valores abaixo dos preços estabelecidos pela Câmara de Regulação do Mercado de Medicamentos. CONCLUSÃO: O eculizumabe representou gastos extremamente significativos para o Ministério da Saúde no período. Todas as compras foram feitas para atendimento de demandas judiciais, fora do ambiente competitivo. Seu registro promoveu queda importante nos preços praticados. O estudo aponta a relevância do registro sanitário e da necessidade de monitoramento e auditoria permanentes das compras de medicamentos para atendimento de demandas judiciai

Plan de marketing para implementar una estación de servicios en Miraflores afiliada a Repsol

La presente tesis se ha elaborado con el propósito de presentar la implementación y operación del negocio de una estación de servicios. La finalidad es presentar esta iniciativa, que estará ubicada en el distrito de Miraflores, diseñando y aplicando una estrategia acorde a las necesidades de los consumidores, que le generen valor tanto a ellos como a los accionistas. En cada uno de los capítulos de la presente tesis se analiza, de forma rigurosa, la información recogida a través de fuentes primarias y secundarias, que permite estructurar este documento con la finalidad de evaluar la viabilidad de esta iniciativa. En el capítulo II, se analiza la situación actual de la industria, con la cual se logra conocer el entorno en que se desenvuelve este negocio. Mediante la recopilación de información se ha podido analizar, diagnosticar y construir las fortalezas, amenazas, oportunidades y debilidades de nuestra propuesta. En el capítulo III, se hace una investigación de mercados de dos formas: una exploratoria y una concluyente. En el primer caso, se recurrió a artículos periódicos, páginas, entrevistas en profundidad a expertos de la industria, y en el segundo caso se realiza una encuesta a potenciales clientes en la zona de influencia donde se ubicaría la estación de servicios. Estas etapas de investigación permitieron conocer las necesidades de los consumidores de la zona y las principales acciones que vienen realizando las diferentes compañía de la industria. Asimismo, con la investigación concluyente se confirmó el potencial de la zona elegida. En el capítulo IV, se plantean los objetivos y estrategias que permitirán lograr el desarrollo a largo plazo del proyecto aplicando las técnicas de marketing que hagan posible el crecimiento sostenido del negocio. En el capítulo V, se plantean las tácticas necesarias para implementar los planes de acción que se derivan del mix de marketing dentro del negocio, que permita alcanzar los objetivos propuestos. Finalmente, el capítulo VI evalúa la viabilidad del proyecto, mediante el uso de herramientas económicas financieras, concluyendo en mostrar la oportunidad que existe para el desarrollo de esta propuesta en el distrito de Miraflores