Protótipo de rastreador solar de um eixo baseado em microcontrolador

The increase in the efficiency of photo-voltaic systems has been the object of various studies the past few years. One possible way to increase the power extracted by a photovoltaic panel is the solar tracking, performing its movement in order to follow the sun’s path. One way to activate the tracking system is using an electric induction motor, which should have sufficient torque and low speed, ensuring tracking accuracy. With the use of voltage source inverters and logic devices that generate the appropriate switching is possible to obtain the torque and speed required for the system to operate. This paper proposes the implementation of a angular position sensor and a driver to be applied in solar tracker built at a Power Electronics and Renewable Energies Laboratory, located in UFRN. The speed variation of the motor is performed via a voltage source inverter whose PWM command to actuate their keys will be implemented in an FPGA (Field Programmable Gate Array) device and a TM4C microcontroller. A platform test with an AC induction machine of 1.5 CV was assembled for the comparative testing. The angular position sensor of the panel is implemented in a ATMega328 microcontroller coupled to an accelerometer, commanded by an Arduino prototyping board. The solar position is also calculated by the microcontroller from the geographic coordinates of the site where it was placed, and the local time and date obtained from an RTC (Real-Time Clock) device. A prototype of a solar tracker polar axis moved by a DC motor was assembled to certify the operation of the sensor and to check the tracking efficiency.

El autocuidado y apoyo social de mujeres de un proyecto de seguimiento mamográfico en Porto Alegre/Brasil

Objective: Identify preventive self-care practices and analyze the configurations of the network support for women with and without breast cancer registered in a mammography-monitoring project from Porto Alegre/Brazil.Method: a mixed sequential delimitation was performed, which expanded the results of the quantitative step (cross and correlation section) in a qualitative step (narrative interviews). 37 women diagnosed with breast cancer (group 1) and 72 without this diagnosis (group 2 – monitoring) participated. The following instruments were used: Assessment Questionnaire Self-care Ability (ASA-A) and Assessment Questionnaire Perceived Social Support and Community. There were performed descriptive analysis and comparison of means (t test and ANOVA) between the two groups. To deepen the understanding of the data, we selected four women with breast cancer with extreme levels on the scale of Social Support to participate in the biographical narrative interviews.Results: the analysis indicate that women who had breast cancer have better self-care practices than the women from the monitoring project (t = 1.791, P = 0.027). As for the analysis of social support, there were no statistically significant differences between the two groups. All participants have an average level of perceived social and community support. It was highlighted by the qualitative data that it was after the diagnosis of breast cancer that women lived self-care aspects they had not previously experienced.Conclusions: the self-care was significantly bigger in the group of women with breast cancer, where the cancer diagnosis was a trigger to increase self-care.

Índices de obesidade central e fatores de risco cardiovascular na síndrome dos ovários policísticos

Fundamento: A obesidade abdominal apresenta elevada prevalência em mulheres com síndrome dos ovários policísticos (SOP) e está associada a um aumento do risco cardiovascular. Objetivo: Verificar a acurácia da circunferência da cintura (CC), da relação cintura-quadril (RCQ), da relação cinturaestatura (RCEST) e do índice de conicidade (índice C), no que se refere à detecção de fatores de risco cardiovascular (FRCV) em mulheres com SOP. Métodos: Por meio de estudo transversal, foram alocadas 102 mulheres (26,5 ± 5 anos) com diagnóstico de SOP, de acordo com o consenso de Rotterdam. O colesterol total (CT), os triglicerídeos (TG), o LDL-colesterol (LDL-C), o HDLcolesterol (HDL-C), a glicemia de jejum, a glicemia após teste oral de tolerância à glicose (TOTG) e a pressão arterial (PA) foram avaliados em todas as pacientes, além das variáveis antropométricas. Resultados: A relação cintura-estatura foi o marcador que apresentou correlações positivas significativas com o maior número de FRCV (PA, TG e glicemia após TOTG), destacando-se ainda a correlação negativa com HDL-C. Todos os marcadores antropométricos avaliados se correlacionaram positivamente com PA, enquanto CC e RCQ apresentaram correlação positiva também com TG. No tocante à acurácia para detecção de FRCV, os indicadores antropométricos considerados apresentaram taxas de sensibilidade superiores a 60%, com destaque para a RCEST, que apresentou sensibilidade superior a 70%. Conclusão: A RCEST demonstrou ser o indicador antropométrico com a melhor acurácia para a predição de FRCV. Nesse sentido, propõe-se a inclusão desse parâmetro de fácil mensuração na avaliação clínica para o rastreamento de mulheres com SOP e FRCV----------------------ABSTRACT Background: Women with polycystic ovary syndrome (PCOS) present a high prevalence of abdominal obesity, which is associated with an increased cardiovascular risk. Objective: To verify the accuracy of the waist circumference (WC), waist-to-hip ratio (WHR), waist-to-height ratio (WHtR) and the conicity index (CI) in the detection of cardiovascular risk factors (CVRF) in women with PCOS. Methods: The present transversal study allocated 102 women (26.5 ± 5 years) with a diagnosis of PCOS, according to the Rotterdam criteria. Total cholesterol (TC), triglycerides (TG), LDL-cholesterol (LDL-C), HDL-cholesterol (HDL-C), fasting glucose, glucose after the oral glucose tolerance test (OGTT) and blood pressure (BP) were evaluated in all patients, in addition to the anthropometric variables. Results: The WHtR was the marker that presented significant positive correlations with the highest number of CVRF (BP, TG and post-OGTT glucose), whereas there was a negative correlation with HDL-C. All the evaluated anthropometric markers were positively correlated with BP, whereas WC and WHR also presented a positive correlation with TG. Regarding the accuracy for the detection of CVRF, the anthropometric markers presented a sensibility > 60%, especially the WHtR, which had a sensibility > 70%. Conclusion: The WHtR showed to be the most accurate anthropometric indicator for the prediction of CVRF. In this sense, we propose the inclusion of this easily-measured parameter in the clinical assessment for the screening of women with PCOS and CVRF

Índices de obesidade central e fatores de risco cardiovascular na síndrome dos ovários policísticos

Fundamento: A obesidade abdominal apresenta elevada prevalência em mulheres com síndrome dos ovários policísticos (SOP) e está associada a um aumento do risco cardiovascular. Objetivo: Verificar a acurácia da circunferência da cintura (CC), da relação cintura-quadril (RCQ), da relação cinturaestatura (RCEST) e do índice de conicidade (índice C), no que se refere à detecção de fatores de risco cardiovascular (FRCV) em mulheres com SOP. Métodos: Por meio de estudo transversal, foram alocadas 102 mulheres (26,5 ± 5 anos) com diagnóstico de SOP, de acordo com o consenso de Rotterdam. O colesterol total (CT), os triglicerídeos (TG), o LDL-colesterol (LDL-C), o HDLcolesterol (HDL-C), a glicemia de jejum, a glicemia após teste oral de tolerância à glicose (TOTG) e a pressão arterial (PA) foram avaliados em todas as pacientes, além das variáveis antropométricas. Resultados: A relação cintura-estatura foi o marcador que apresentou correlações positivas significativas com o maior número de FRCV (PA, TG e glicemia após TOTG), destacando-se ainda a correlação negativa com HDL-C. Todos os marcadores antropométricos avaliados se correlacionaram positivamente com PA, enquanto CC e RCQ apresentaram correlação positiva também com TG. No tocante à acurácia para detecção de FRCV, os indicadores antropométricos considerados apresentaram taxas de sensibilidade superiores a 60%, com destaque para a RCEST, que apresentou sensibilidade superior a 70%. Conclusão: A RCEST demonstrou ser o indicador antropométrico com a melhor acurácia para a predição de FRCV. Nesse sentido, propõe-se a inclusão desse parâmetro de fácil mensuração na avaliação clínica para o rastreamento de mulheres com SOP e FRCV----------------------ABSTRACT Background: Women with polycystic ovary syndrome (PCOS) present a high prevalence of abdominal obesity, which is associated with an increased cardiovascular risk. Objective: To verify the accuracy of the waist circumference (WC), waist-to-hip ratio (WHR), waist-to-height ratio (WHtR) and the conicity index (CI) in the detection of cardiovascular risk factors (CVRF) in women with PCOS. Methods: The present transversal study allocated 102 women (26.5 ± 5 years) with a diagnosis of PCOS, according to the Rotterdam criteria. Total cholesterol (TC), triglycerides (TG), LDL-cholesterol (LDL-C), HDL-cholesterol (HDL-C), fasting glucose, glucose after the oral glucose tolerance test (OGTT) and blood pressure (BP) were evaluated in all patients, in addition to the anthropometric variables. Results: The WHtR was the marker that presented significant positive correlations with the highest number of CVRF (BP, TG and post-OGTT glucose), whereas there was a negative correlation with HDL-C. All the evaluated anthropometric markers were positively correlated with BP, whereas WC and WHR also presented a positive correlation with TG. Regarding the accuracy for the detection of CVRF, the anthropometric markers presented a sensibility > 60%, especially the WHtR, which had a sensibility > 70%. Conclusion: The WHtR showed to be the most accurate anthropometric indicator for the prediction of CVRF. In this sense, we propose the inclusion of this easily-measured parameter in the clinical assessment for the screening of women with PCOS and CVRF

Custos da qualidade: um estudo no polo naval da cidade de Rio Grande/ RS

O objetivo geral do estudo fixou-se em identificar qual forma de planejamento e método de controle dos custos da qualidade é utilizado pela empresa representante do estaleiro no polo Naval da cidade de Rio Grande, visto que a expansão do polo naval trouxe ao município um grande impacto financeiro, econômico e social e a demanda por produtos com qualidade tornou-se realidade constante. Após a análise dos dados, os resultados apontaram indícios de planejamento dos custos da qualidade e os fatores determinantes para tal constatação foram as práticas da entidade em elaborar orçamento formal contemplando os custos da qualidade. Em relação ao controle, constatou-se que a entidade analisada controla os custos da qualidade através dos relatórios fornecidos pela contabilidade de custos. Apesar da existência de controle dos custos da qualidade, existem vestígios de que este controle seja parcial e que os custos possam estar subavaliados. Por fim, identificaram-se sinais de esforços provenientes da empresa com relação ao reconhecimento da importância do planejamento e controle dos custos da qualidade, porém, esforços que ainda precisam ser aprimorados para que a entidade possa usufruir de uma gestão plena. Sugere-se, portanto, a identificação dos custos da qualidade de acordo com cada categoria e natureza, o que irá possibilitar à companhia o rastreamento correto de quais custos estão consumindo o resultado da empresa. A adequada segregação destes custos irá fornecer dados pontuais para a aplicação de procedimentos e práticas corretivas no processo produtivo, tornando eficaz o sistema de qualidade.

Projeto, implementação e análise de um conversor CC-CC de alto ganho e alto rendimento para aplicações fotovoltaicas

In recent years the photovoltaic generation has had greater insertion in the energy mix of the most developed countries, growing at annual rates of over 30%. The pressure for the reduction of pollutant emissions, diversification of the energy mix and the drop in prices are the main factors driving this growth. Grid tied systems plays an important role in alleviating the energy crisis and diversification of energy sources. Among the grid tied systems, building integrated photovoltaic systems suffers from partial shading of the photovoltaic modules and consequently the energy yield is reduced. In such cases, classical forms of modules connection do not produce good results and new techniques have been developed to increase the amount of energy produced by a set of modules. In the parallel connection technique of photovoltaic modules, a high voltage gain DC-DC converter is required, which is relatively complex to build with high efficiency. The current-fed isolated converters explored in this work have some desirable characteristics for this type of application, such as: low input current ripple and input voltage ripple, high voltage gain, galvanic isolation, feature high power capacity and it achieve soft switching in a wide operating range. This study presents contributions to the study of a high gain and high efficiency DC-DC converter for use in a parallel system of photovoltaic generation, being possible the use in a microinverter or with central inverter. The main contributions of this work are: analysis of the active clamping circuit operation proposing that the clamp capacitor connection must be done on the negative node of the power supply to reduce the input current ripple and thus reduce the filter requirements; use of a voltage doubler in the output rectifier to reduce the number of components and to extend the gain of the converter; detailed study of the converter components in order to raise the efficiency; obtaining the AC equivalent model and control system design. As a result, a DC-DC converter with high gain, high efficiency and without electrolytic capacitors in the power stage was developed. In the final part of this work the DC-DC converter operation connected to an inverter is presented. Besides, the DC bus controller is designed and are implemented two maximum power point tracking algorithms. Experimental results of full system operation connected to an emulator and subsequently to a real photovoltaic module are also given.

PREVALENCE AND FACTORS ASSOCIATED WITH THE PERFORMANCE OF MAMMOGRAPHY AND PAP SMEAR TEST

Objective: To estimate the prevalence and factors associated with the performance of mammography and pap smear test in women from the city of Maringá, Paraná. Methods: Population-based cross-sectional study conducted with 345 women aged over 20 years in the period from March 2011 to April 2012. An interview was carried out using a questionnaire proposed by the Ministry of Health, which addressed sociodemographic characteristics, risk factors for chronic noncommunicable diseases and issues related to mammographic and pap screening. Data were analyzed using bivariate analysis, crude analysis with odds ratio (OR) and chi-squared test using Epi Info 3.5.1 program; multivariate analysis using logistic regression was performed using the software Statistica 7.1, with a significance level of 5% and a confidence interval of 95%. Results: The mean age of the women was 52.19 (±5.27) years. The majority (56.5%) had from 0 to 8 years of education. Additionally, 84.6% (n=266) of the women underwent pap smear and 74.3% (n=169) underwent mammography. The lower performance of pap smear test was associated with women with 9-11 years of education (p=0.01), and the lower performance of mammography was associated with women without private health insurance (p<0.01). Conclusion: The coverage of mammography and pap smear test was satisfactory among the women from Maringá, Paraná. Low education level and women who depended on the public health system presented lower performance of mammography.

EIR – sistema inteligente para detecção e classificação de calcificações em mamografias

Dissertação (mestrado)—Universidade de Brasília, Faculdade Gama, Programa de Pós-Graduação em Engenharia Biomédica, 2016.

Caracterização clínica, metabólica e hormonal de portadores de lipodistrofia parcial familiar

Dissertação (mestrado)—Universidade de Brasília, Faculdade de Ciências da Saúde, Programa de Pós-Graduação em Ciências da Saúde, 2015.

Padrões de ratreamento na visualização de faces próprias e não próprias

Dissertação (mestrado)—Universidade de Brasília, Instituto de Psicologia, Departamento de Processos Psicológicos Básicos, Programa de Pós-Graduação em Ciências do Comportamento, 2016.

Tecnologia GNSS de baixo custo na monitorização de ovinos em pastoreio

Extensive livestock production is supported by natural and biodiverse pastures, characterized by marked seasonal variation of biomass, plant species and growth stage. The use of the food resources and the occupation of grazing space can be very heterogeneous in such conditions due to ruminants grazing behaviour. Successful grazing and pasture management requires an understanding of the adjustment mechanisms behind the grazing behaviour that enables adaptation to grazing conditions. Use of GNSS technology allows a quick and effective grazing data collection which is, however expensive, limiting its application to research purposes. This paper reviews the principles for the application of GNSS technology and evaluates the use of inexpensive commercial GNSS receivers (commercial of the shelf - COTS: CatTrackTM”). Six receivers were used for six data collection period over two months of continuous grazing on a natural pasture. The measured static and dynamic accuracy of the receivers is 14m and 40m, respectively. The precision was 3m and the reliability 80%. The tested equipment allows the differentiation between animal activities (grazing, resting and transit). It also determines sheep locations, allowing the characterization of patterns, pathways and preferred areas. It is concluded that the COTS equipment has a high quality / price ratio, so it can become an important support decision tool essential to a more precise pasture management.