Search results for "current"

Dynamics of Vertebral Column Observed by Stereovision and Recurrent Neural Network Model

2005

A new non-invasive method for investigation of movement of selected points on the vertebral column is presented. The registration of position of points marked on patient's body is performed by 4 infrared cameras. This experiment enables to reconstruct 3-dimensional trajectories of displacement of marked points. We introduce recurrent neural networks as formal nonlinear dynamical models of each point trajectory. These models are based only on experimental data and are set up of minimal number of parameters. Therefore they are suitable for pattern recognition problems.

A lossless current sensing technique for flyback converters

2009

Regardless of the feedback control, almost all converters require input or output current sense for overcurrent protection. If a current mode control is implemented, high accuracy is also required. The optimal current sensing method shows the highest accuracy and the lowest power dissipation. In this paper, a lossless and accurate current sensing technique for Flyback converters is proposed. An RC network is parallel connected with the primary MOSFET and the voltage signal across the sense capacitor accurately reproduces the magnetizing current waveform. The RC technique benefits from all the advantages of the most common current sensing techniques currently applied to Flyback converters, a…

Aktuelle Therapie von Intoxikationen

2003

Current issues in hyperpolarized gases in MRI: biomedical investigations and clinical applications

2000

Specific Anti-Infective Immune Therapy

1997

Sensorless control of permanent magnet synchronous motors for wide speed range applications

2006

This paper deals with sensorless control of Interior Permanent Magnet Synchronous Motors (IPMS) based on the estimation of speed and rotor angular position. The above estimate is based on the injection of high frequency stator currents able to generate a signal similar to that generated by a resolver connected to the axis of the motor. A new digital algorithm has been designed to demodulate the above signal whose implementation can be carried out on the same DSP that processes the control algorithm. In this paper a new scheme of speed and angular position estimator is proposed and justified on the theoretic point of view. The experimental results here shown validate the effectiveness of the…

Sacral neurostimulation and neuromodulation in urological practice

2000

The problems associated with treating various forms of lower tract dysfunction by electrical stimulation are reflected in the many years of basic and clinical research in this area. However, better understanding of both neuroanatomy and neurophysiology, and development of new technologies have led to further application of electrical current to restore impaired bladder function. Contemporary knowledge of the potential for both sacral neurostimulation and neuromodulation as a therapeutic option for lower urinary tract dysfunction is reviewed.

Role of thyroid hormones in burning mouth syndrome. Systematic review

2022

Background: Burning mouth syndrome is an idiopathic condition characterized by burning pain in a normalappearing oral mucosa lasting at least four to six months. In the case of secondary burning mouth syndrome is associated with local or systemic factors (such as thyroid disorders) that can cause these symptoms. The aim of this review was to study the relationship between thyroid disorders and burning mouth syndrome. Material and Methods: The present study followed the PRISMA guidelines. An electronic search strategy was developed for PubMed/Medline, Scopus and Cochrane. The following combination of keywords and Boolean operators were used: Thyroid AND burning mouth; Thyroid AND burning mou…

Hydrophobicity of Ionizable Compounds. A Theoretical Study and Measurements of Diuretic Octanol−Water Partition Coefficients by Countercurrent Chroma…

1999

Countercurrent chromatography was used to determine the octanol−water partition coefficients (Po/w) of 23 diuretic drugs. The measured Po/w values ranged over 4 orders of magnitude from 0.05 to 550 (−1.3 < log Po/w < +2.7). All the compounds, except spironolactone, were ionizable. The Po/w values were strongly depending on the aqueous-phase pH. A theoretical model linking these values with the pH was derived for four cases:  (i) molecular acid−anionic base, (ii) cationic acid−molecular base, (iii) biprotic systems with two acidic or basic groups showing the same charge sign, and (iv) biprotic systems with ionizable groups showing different charges with special attention to the amino acid ca…

Photoelectrochemical Synthesis of Polypyrrole on Anodic Ta[sub 2]O[sub 5] Films

2007

Polypyrrole film was photoelectrochemically grown on insulating Ta 2 O 5 anodic film in acetonitrile solution. A characterization by photocurrent spectroscopy (PCS) of metal/oxide/polypyrrole interface was carried out. The PCS results suggest that a metallic-like PPy is formed under illumination at constant anodic potential. By polarizing the polypyrrole at cathodic potentials a photocurrent spectrum typical of p-type semiconducting film was recorded. A scanning electron microscopy study of PPy surfaces solution side and oxide side allowed us to obtain information on the morphology of the polymer as well as a rough estimate of the film thickness and of the diameter of PPy globules at the tw…