This paper presents a method to analyse electrical machines considering simultaneously the electromagnetic field, electric circuit, control loop, movement and skewing effects. The major contribution of this work leans on its generality, i.e. it can be applied to electrical machines connected to static converters submitted to any control laws, avoiding an a priori analysis. Simulation results of a three‐phase Brushless AC (BLAC) motor fed by a PWM converter is presented as well as a comparison of simulation and experimental results obtained using a two‐phase‐on converter were also presented.
A model allowing the simulation of induction machines with different rotor bars configurations is presented. The electrical machine is modeled by using two-dimensional (2-D) finite-element method and its equations are directly coupled with those of the circuit. A general and new contribution is added for the consideration of special rotor bars topologies. The movement is taken into account by means of the moving band technique, the Maxwell stress tensor, and the mechanical oscillation equation. The model is applied to a brushless doubly fed induction motor. Index Terms-Brushless doubly fed machine (BDFM), induced currents, thick conductors, two-dimensional (2-D) finite-element method (FEM).
The quality of human milk expressed at home and at the milk bank are in agreement with the recommended standards, confirming that the expression of human milk at home is as safe as expression at the human milk bank, provided that the established hygiene, conservation, storage, and transport standards are followed.
BackgroundToxoplasmosis is a zoonosis caused by Toxoplasma gondii, an intracellular protozoan parasite able to infect a wide range of hosts, including humans. Congenital infection can cause severe damage to the fetus. Thus, it is important to detect antibodies against the parasite to confirm clinical manifestations. Considering that all immunoglobulin isotypes may be present in biological samples from newborns and their mothers, this study aimed to evaluate the ability to diagnose recent toxoplasmosis by using colostrum, as an alternative noninvasive way to obtain biological samples, as well as to determine correlation rates between antibodies from serum samples to detect IgG, IgM and IgA isotypes against T. gondii.MethodsA total of 289 puerperal women from Clinical Hospital of Federal University of Uberlândia (mean age: 24.8 years, range: 14 – 43 years) took part in this study. Serum and colostrum samples from these patients were analyzed using ELISA and immunoblotting assays for soluble antigens from T. gondii.ResultsELISA immunoassays with serum samples showed reactivity in 47.0, 6.9 and 2.8 % of samples to anti-T. gondii IgG, IgM and IgA, respectively, in comparison with colostrum samples, which showed reactivity in 46.0, 7.9 and 2.8 % of samples to the same isotypes. Also, significant correlation rates of anti-T. gondii antibody levels between serum and colostrum samples were observed. Interestingly, reactivity to IgM and/or IgA in colostrum and/or serum confirmed clinical manifestations of congenital toxoplasmosis in three newborns. Immunoblotting assays showed that it is possible to detect IgG, IgM and IgA antibodies against various antigens of T. gondii in serum and colostrum samples. IgG antibodies in serum and colostrum samples recognized more antigenic fractions than IgM and IgA antibodies. Serum IgG detected more antigenic fractions than IgG antibodies present in the colostrum of the same patient. In contrast, specific IgA present in colostrum recognized a higher number of antigens than IgA present in serum samples of the same patient.ConclusionsOverall, the results show that it is important to investigate the occurrence of congenital toxoplasmosis, even at puerperal period. Furthermore, this study demonstrates that T. gondii-specific IgG, IgM and IgA antibodies in serum and colostrum samples from puerperal women may be detected with a significant correlation, suggesting that colostrum may also be used as an alternative biological sample to efficiently diagnose recent human toxoplasmosis.
RESUMOA lactogênese é constituída pelas fases designadas como I e II. A transição entre essas fases é caracterizada pelo aumento da concentração de lactose no colostro. Este estudo teve como objetivo analisar a interferência do diabetes melito tipo 1 (DM1) na transição entre as fases da lactogênese. A concentração de lactose foi determinada em amostras de colostro de 11 puérperas portadoras de DM1 e de 19 puérperas sem a doença, durante os cinco primeiros dias do puerpério. A determinação da concentração da lactose foi feita pela reação com ácido pícrico. Em ambos os grupos houve aumento progressivo da concentração da lactose em função do tempo; entretanto, o aumento foi significativamente menor no terceiro e no quinto dia no grupo das portadoras de diabetes. A análise da transição de fases da lactogênese revelou que as puérperas portadoras de diabetes melito com controle glicêmi-co inadequado apresentaram atraso de 18 horas para alcançar a fase II da lactogênese, dificultando o estabelecimento do aleitamento materno. Lactogenesis is constituted by phases I and II. The transition between those phases is characterized by an increase of the lactose concentration in the colostrum. This study aimed to evaluate the interference of type 1 Diabetes mellitus in the transition between phases I and II of the lactogenesis. The lactose concentration was determined in colostrum samples of 11 puerperal women with pre-gestational Diabetes mellitus and 19 without the disease, during the five first days of the puerperium. The lactose concentration was determined by reaction with picric acid. In both groups there were progressive increases in the lactose levels along the time; however, the increase was significantly lower in the 3 rd and 5 th days for the group of the women with diabetes. The analysis of the transition between the lactogenesis phases revealed that the puerperal diabetic women with inadequate glycemic control presented a time delay of 18 hours to reach phase II, making difficult the establishment of breastfeeding. (Arq Bras Endocrinol Metab 2008; 52/3:473-481)
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