Raposo A.A.M.,UFMA |
Rodrigues A.B.,UFMA |
da Silva M.D.G.,UFMA
Electric Power Systems Research | Year: 2017
This paper proposes an algorithm to allocate meters in distribution networks to increase the accuracy of the state estimation. This algorithm considers three new issues in the meter placement problem: correlated measurements, multiple load levels and accuracy evaluation of state estimation without using Monte Carlo Simulation (MCS), that is, based on analytical approach. The objective function used in the meters placement problem is associated with the maximization of the accuracy of the state estimator. This objective function is optimized considering constraints for the maximum number of meters that can be installed and for the accuracy of the state estimator. The optimization problem is solved with the binary particle swarm algorithm. The tests results indicated that the meter placement obtained with the proposed algorithm is very accurate for all levels of the load curve. For example, it has been shown that the accuracy of state estimation is four times better when the correlation in power measurements is included in the model. In addition, the computational cost of estimating the accuracy of the state estimate based on the proposed analytical approach is about 47 times lower than that associated with MCS. © 2017 Elsevier B.V.
Lamy Filho F.,Federal University of Maranhão |
Lopes J.M.A.,Instituto Fernandes Figueira |
Jornal de Pediatria | Year: 2011
Objective: To investigate a possible association between the intensity of staff workload and intermediate adverse events, such as accidental extubation, obstruction of the endotracheal tube, and accidental disconnection of the ventilator circuit, during neonatal mechanical ventilation in high-risk neonatal units. Method: This prospective cohort study analyzed data of 543 newborns from public neonatal intensive care units (NICUs) in the city of São Luís, state of Maranhão, Northeastern Brazil, for 6 months, during which 136 newborns were submitted to mechanical ventilation in 1,108 shifts and were observed a total of 4,554 times. Results: Adverse events occurred 117 times during this period. The associations between workload and adverse events were analyzed by means of generalized estimating equations. The adjustment variables were: birth weight, gender, maternity unit, Clinical Risk Index for Babies score, and care demand, the latter measured by the Northern Neonatal Network Scale. The larger the number of newborns classified by care demand (NCCD) per nurse and nursing technician, the more likely the occurrence of intermediate adverse events linked to mechanical ventilation. A number of NCCD > 22 per nurse (relative risk [RR] = 2.86) and > 4.8 per auxiliary nurse (RR = 3.41) was associated with a higher prevalence of intermediate adverse events. Conclusions: The workload of NICU professionals seems to interfere with the intermediate results of neonatal care and thus should be taken into consideration when evaluating NICU outcomes. Copyright © 2011 by Sociedade Brasileira de Pediatria.
Faria C.,UFMA |
Girardi R.,UFMA |
Novais P.,University of Minho
International Conference on Intelligent Systems Design and Applications, ISDA | Year: 2012
This article proposes a process for automatic population of ontologies from text that applies natural language processing and information extraction techniques to acquire and classify ontology instances. The work is part of HERMES, an FCT/CAPES research project looking for techniques and tools for automating the process of ontology learning and population. Two experiments using a legal and a tourism corpora were conducted in order to evaluate it. The results indicate that our approach can extract and classify instances with high effectiveness with the additional advantage of domain independence. © 2012 IEEE.
Lopes C.S.D.,State University Londrina |
de Azevedo P.S.,UFMA
Environment, Development and Sustainability | Year: 2013
Despite more than 20 years of economic progress, especially in emerging economies like Brazil, the gap between developed and developing countries is still large, and environment problems have risen significantly. In this context, this paper aims to make the Brazilian furniture production cleaner, analyzing the environmental requirements considered by the micro and small enterprises (SMEs) in made-to-order furniture industry during the product development process (PDP). Another attempt was to identify the internal and external factors that led to the incorporation of these requirements. In this regard, a comprehensive review of eco-design concept that consists of composing environmental requirements into the PDP, through methods, tools, guidelines and techniques, was carried out. The data were collected using semi-structured interviews and in loco observations, analyzing each activity of the PDP and the environmental requirements on 18 SMEs in Brazil. The outcomes show that the economic factors determine the way in which the enterprises respond to the environmental issues and how adequate their companies according to laws and regulations. Moreover, the small number of qualified professionals in this field lead to difficulties to structure the sector, in other words, to produce with less environment impact. © 2013 Springer Science+Business Media Dordrecht.
Da Silva Filho E.C.,Federal University of Piauí |
Santana S.A.A.,UFMA |
Melo J.C.P.,University of Campinas |
Oliveira F.J.V.E.,University of Campinas |
Airoldi C.,University of Campinas
Journal of Thermal Analysis and Calorimetry | Year: 2010
Cellulose was chemically modified with SOCl2 to obtain chlorodeoxycellulose, followed by a reaction that gave bonded ethylene-1,2-diamine (en), producing 6-(2′-aminoethylamino)-6- deoxycellulose. The reactions were carried out without the presence of solvent, in water or in N,N′-dimethylformamide, in which the highest amount of amino compound was incorporated onto the biopolymer backbone. The X-ray diffraction patterns for the chlorodeoxycellulose indicate new crystallinities that result from hydrogen bonds established through bonded chorine atoms and the remaining hydroxyl groups, while all the aminodeoxycelluloses were amorphous compounds. Thermal stabilities, for all aminated celluloses gave lower final mass losses than for the chlorinated biopolymer, whose value is lower than unmodified cellulose. © 2009 Akadémiai Kiadó, Budapest, Hungary.
Lima R.M.,Uema |
Ambiente e Sociedade | Year: 2015
The objective of this project is to focus on the environmental conflict involving the government and the residents of Jardim Icaraí in Curitiba, Brazil. This exercise examines environmental law as an instrument for producing and disseminating the "official version" of the environment and the city's intervention plan. Environmental Law not only provides legitimacy to this plan, but is also intimately associated to the urban policies in Curitiba.
PubMed | Rede Nordeste de Biotecnologia, UFMA and Federal University of Maranhão
Type: Journal Article | Journal: Ciencia & saude coletiva | Year: 2016
A cross-sectional population-based study using questionnaire and anthropometric data was conducted on 968 university students of So Lus, Brazil, from which 590 showed up for blood collection. In the statistical analysis the Student t-test, Mann-Whitney and chi-square tests were used. The prevalence of metabolic syndrome by the Joint Interim Statement (JIS) criteria was 20.5%, almost three times more prevalent in men (32.2%) than in women (13.5%) (P < 0.001). The prevalence of insulin resistance was 7.3% and the prevalence of low HDL-cholesterol was high (61.2%), both with no statistically significant differences by sex. Men showed a higher percentage of smoking, overweight, high blood pressure, high blood glucose and increased fasting hypertriglyceridemia. Women were more sedentary. University students of private institutions had higher prevalences of sedentary lifestyle, obesity, abdominal obesity, elevated triglycerides and metabolic syndrome than students from public institutions. High prevalences of metabolic syndrome, insulin resistance and other cardiovascular risk factors were found in this young population. This suggests that the burden of these diseases in the future will be increased.
Silva E.N.M.,UFMA |
Rodrigues A.B.,UFMA |
da Guia da Silva M.,UFMA
Electric Power Systems Research | Year: 2016
This paper aims to assess the impact of photovoltaic distributed generation (PVDG) connection on the power quality indices (PQI) of distribution networks, such as: long term voltage variations (voltage conformity issues) and voltage unbalance. The stochastic nature of PVDG and loads were considered in the study using probabilistic techniques. The impact of PVDG on the number of tap changes of the voltage regulators was investigated. The tests results in a real life large scale distribution network demonstrated that the PVDG can cause around 31% of improvements in the voltage conformity indices. This impact is less beneficial than the one associated with the connection of conventional distributed generation due to the variability in the primary energy resource. Furthermore, it was demonstrated that the connection of PVDG increases the lifespan of the voltage regulators as a result of a reduction about 20% in the number of tap changes. © 2016 Elsevier B.V.
Damos F.S.,University of Campinas |
Damos F.S.,Federal University of Vales do Jequitinhonha and Mucuri |
Luz R.C.S.,University of Campinas |
Luz R.C.S.,Federal University of Vales do Jequitinhonha and Mucuri |
And 3 more authors.
Analytica Chimica Acta | Year: 2010
The development of a simple, efficient and sensitive sensor for dissolved oxygen is proposed using the host-guest binding of a supramolecular complex at a host surface by combining a self-assembled monolayer (SAM) of mono-(6-deoxy-6-mercapto)-β-cyclodextrin (βCDSH), iron (III) tetra-(N-methyl-4-pyridyl)-porphyrin (FeTMPyP) and cyclodextrin-functionalized gold nanoparticles (CDAuNP). The supramolecular modified electrode showed excellent catalytic activity for oxygen reduction. The reduction potential of oxygen was shifted about 200mV toward less negative values with this modified electrode, presenting a peak current much higher than those observed on a bare gold electrode. Cyclic voltammetry and rotating disk electrode (RDE) experiments indicated that the oxygen reduction reaction involves probably 4-electrons with a rate constant (kobs) of 7×104mol-1Ls-1. A linear response range from 0.2 up to 6.5mgL-1, with a sensitivity of 5.5μALmg-1 (or 77.5μAcm-2Lmg-1) and a detection limit of 0.02mgL-1 was obtained with this sensor. The repeatability of the proposed sensor, evaluated in terms of relative standard deviation was 3.0% for 10 measurements of a solution of 6.5mgL-1 oxygen. © 2010 Elsevier B.V.
PubMed | UFMA and Federal University of Maranhão
Type: Journal Article | Journal: Ciencia & saude coletiva | Year: 2016
This study analyzed the relationship between rainfall, temperature and occurrence of dengue cases. Ecological study performed with autochthonous dengue cases reported during 2003 to 2010 in So Lus, Maranho. Data of rainfall and temperature were collected monthly. The monthly incidence of dengue cases was calculated by year/100,000 inhabitants. In order to identify the influence of climate variables and dengue cases different distributed lag models using negative binomial distribution were considered. Model selection was based on the lowest AIC (Akaike Information Criterion). Thirteen thousand, four hundred forty-four cases of dengue between 2003 and 2010 were reported, with peaks in 2005, 2007 and 2010. The correlation between rainfall and the occurrence of dengue cases showed increase in the first months after the rainy months. Occurrence of dengue cases was observed during all the period of study. Only rainfall-lag per three months showed a positive association with the number of cases dengue. Thus, this municipality is considered as an endemic and epidemic site. In addition, the relation between rainfall and dengue cases was significant with a lag of three months. These results should be useful to the future development of politics healthy for dengue prevention and control.