A PC-based architecture for parameter analysis of vector-controlled induction motor drive

In this article a methodology for constructing a user interface for system control and data acquisition of a drive which is suitable for three-phase induction motors (3?IM) is presented. The entire hardware implementation is shown, including power and digital stages. Communication between the computer and the controller is engaged in order to enhance an analysis of power quality, adjust the controller parameters for tuning the flux and speed loops, and performance of the embedded algorithm. USB and Ethernet protocols have been put into operation in the user front-end because a high speed sample frequency is required in order to guarantee the real-time operation of the whole system. A software interface is developed using LabVIEW environment enabling features not only as filtering signals of phase voltage and current but also power spectrum measurements. Vector-controlled drive is programmed on a digital signal processor (DSP) in order to ensure efficient use of energy in the power stage and proper tracking of the reference at low and high speeds.     

Morphological contrast index based on the Weber's law

In this article, a morphological contrast index based on the Weber's law is proposed to quantify the contrast in a processed image. This measure involves the contours of the image along with its background. The proposal made here is applied to detect the image with higher contrast, and also identify the enhanced image most similar to the original. Moreover, the contrast index is compared with other four indexes reported in the current literature. © 2012 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 22, 137–144, 2012     

Long-term effect of norepinephrine on iodide uptake in FRTL-5 cells

The sympathetic nervous system plays a role in the regulation of thyroid function. In FRTL-5 rat thyroid cells, norepinephrine (NE) acutely depresses intracellular I- by increasing I- efflux. The present study was undertaken to determine the effect of NE on iodide transport after a longer time period. NE inhibited the ability of thyrotropin (TSH) to induce iodide uptake by FRTL-5 cells after 48 or 72 hours, but not after 24 hours. The effect of NE was more evident with increasing concentrations of TSH. NE did not modify the rate of I- efflux. Inhibition was associated with a decrease in the Vmax and no change in the Km for iodide influx. To determine if this was a generalized effect of NE on thyroid cell membrane, the uptake of alpha-aminoisobutyric acid (a nonmetabolizable aminoacid) and of 2-deoxyglucose was measured. NE did not inhibit TSH stimulation of the uptake of the two compounds. NE inhibited the action of dibutyryl cAMP (dbcAMP) on iodide uptake in a similar manner to TSH, but did not alter the cyclic adenosine monophosphate (cAMP) levels increased by TSH. The effects of different adrenoreceptor agonists and antagonists demonstrated that norepinephrine acts through an alpha1-adrenergic receptor.     

Image dehazing using morphological opening,dilation and Gaussian filtering

Image pre-processing is a critical stage in computer vision systems, with greater relevance when the input images are captured in outdoor environments because the pictures could contain low contrast and modified colors. A common condition present in outdoor images is haze. In this work, a new dehazing algorithm based on dark channel prior mathematical morphology operations (opening and dilation), and a Gaussian filter, is proposed. Moreover, the proposed algorithm performance is compared qualitatively and quantitatively against previously reported algorithms. Obtained results show that the proposed algorithm requires less processing time providing higher quality dehazing results than other state-of-the-art approaches.     

Finite signals in planar waveguides

We examine the evolution in phase space of an N-point signal, produced and sensed at finite arrays transverse to a planar waveguide within the framework of the finite quantization of geometric optics. We use the Kravchuk coherent states provided by the finite oscillator model to evince the nonlinear transformations that elliptic-profile waveguides produce on phase space by means of the SO(3) Wigner function.     

Application of morphological connected openings and levelings on magnetic resonance images of the brain

In this article, several advanced connected transformations from mathematical morphology for computational neuroanatomy applications are developed. In particular, brain is separated from the skull in MRI T₁ using morphological connected openings. The use of connected transformations allow the preservation of regions, without introduce new information. As a result, the segmented brains preserve by complete information of the original images being more reliable for the specialist who deals with information such as white and gray matter. © 2011 Wiley Periodicals, Inc. Int J ImagingSyst Technol, 21, 336–348, 2011     

Abdominal obesity epidemiology amongst adult women resident in Southern Brazil

The objective of this study was to investigate the risk factors associated with abdominal obesity in women. A cross-sectional population based study was carried out on 981 women aged 20 to 60 years living in Southern Brazil. Abdominal adiposity was assessed by waist circumference (WC) = 88 cm. Poisson regression models were used to obtain prevalence ratios (PR) and their confidence intervals. The abdominal obesity prevalence was 23.3% (IC95%: 20.7-26.0). The main factors associated with the outcome were: having low education level, being unemployed, being more than 40 years old, having family obesity history, and being married. Adjusted analyses showed increased obesity prevalence in hypertensive women (Prevalence Ratio--PR = 2.06; CI95%: 1.58-2.69) and those having higher number of children (PR = 1.17; CI95% 1.00-1.37). Later menarche, at 12-13 years and at 14 years of age, protected against obesity comparing to women with earlier menarche at 8-11 years, respectively, 31% and 46% of protection. The understanding of how the abdominal obesity is distributed among the population allows effective planning and action implementation towards the reduction rates of this nutritional and public health problem.     

Docking and Molecular Dynamic of Microalgae Compounds as Potential Inhibitors of Beta-Lactamase

Bacterial resistance is responsible for a wide variety of health problems, both in children and adults. The persistence of symptoms and infections are mainly treated with β-lactam antibiotics. The increasing resistance to those antibiotics by bacterial pathogens generated the emergence of extended-spectrum β-lactamases (ESBLs), an actual public health problem. This is due to rapid mutations of bacteria when exposed to antibiotics. In this case, β-lactamases are enzymes used by bacteria to hydrolyze the beta-lactam rings present in the antibiotics. Therefore, it was necessary to explore novel molecules as potential β-lactamases inhibitors to find antibacterial compounds against infection caused by ESBLs. A computational methodology based on molecular docking and molecular dynamic simulations was used to find new microalgae metabolites inhibitors of β-lactamase. Six 3D β-lactamase proteins were selected, and the molecular docking revealed that the metabolites belonging to the same structural families, such as phenylacridine (4-Ph), quercetin (Qn), and cryptophycin (Cryp), exhibit a better binding score and binding energy than commercial clinical medicine β-lactamase inhibitors, such as clavulanic acid, sulbactam, and tazobactam. These results indicate that 4-Ph, Qn, and Cryp molecules, homologous from microalgae metabolites, could be used, likely as novel β-lactamase inhibitors or as structural templates for new in-silico pharmaceutical designs, with the possibility of combatting β-lactam resistance     

An adaptive observer for wind velocity using a new torque model of a wind turbine

In this paper, a new mechanical torque model of a wind system is presented, which is used to design an adaptive observer, whose goal is to estimate the wind speed and the mechanical torque in a wind turbine. This adaptive observer allows to obtain, in real time, the turbine maximum power point with wind turbine power control purposes without requiring the precise knowledge of the performance coefficient curve or look-up tables, that are currently used in most control schemes. The new model is compared with a heuristic model and validated with an experimental system.