873 research outputs found
Fractional order calculus on the estimation of short-circuit impedance of power transformers
This paper reports investigation on the use of fractional order calculus to analytically estimate the inlfuence of skin and proximity effects in the short circuit impedance of power transformers. The aim is to better characterize the medium frequency range behavior of leakage inductances of power transformer models, which include terms to represent the magnetic field diffusion process in the windigns. Comparisons between calculated and measured values are shown and discussed.N/
On the Estimation of the Short-Circuit Impedance of Power Transformers Using Fractional Order Calculus
This paper reports investigation on the estimation of the short circuit
impedance of power transformers, using fractional order calculus to analytically
study the influence of the diffusion phenomena in the windings. The aim is to better
characterize the medium frequency range behavior of leakage inductances of power
transformer models, which include terms to represent the magnetic field diffusion
process in the windings. Comparisons between calculated and measured values are
shown and discussed
Short-Circuit Impedance of Power Transformers: the Fractional Order Calculus Approach
First IFAC Workshop on Fractional Differentiation and Its Application - 19-21 July 2004, Enseirb, Bordeaux, France - FDA'04This paper reports investigation on the modeling of the short circuit
impedance of power transformers, using fractional order calculus, analyzing the
influence of the diffusion phenomena in the windings. This aims to better
characterize the medium frequency range behavior of leakage inductances of power
transformer models, which include terms to represent the magnetic field diffusion in
the windings. Calculated and measured values are shown and compared
Multiplex immunoassay for inflammatory proteins quantification in saliva – a methodologic approach
info:eu-repo/semantics/publishedVersio
Antimicrobial and cytotoxic activities of 1,2,3-triazole-sucrose derivatives
A library of 1-(1′,2,3,3′,4,4′,6-hepta-O-acetyl-6′-deoxy-sucros-6′-yl)-1,2,3-triazoles have been investigated
for their antibacterial, antifungal and cytotoxic activities. Most of the target compounds showed
good inhibitory activity against a variety of clinically and food contaminant important microbial pathogens.
In particular, 1-(1′,2,3,3′,4,4′,6-hepta-O-acetyl-6′-deoxy-sucros-6′-yl)-4-(4-pentylphenyl)-1,2,3-
triazole (5) was highly active against all the tested bacteria with minimal inhibitory concentrations (MICs)
ranging between 1.1 and 4.4 μM and bactericidal concentrations (MBCs) from 2.2 and 8.4 μM. The compound
1-(1′,2,3,3′,4,4′,6-hepta-O-acetyl-6′-deoxy-sucros-6′-yl)-4-(4-bromophenyl)-1,2,3-triazole (3) showed
antifungal activity with MICs from 0.6 to 4.8 μM and minimal fungicidal concentrations (MFCs) ranging
between 1.2 and 8.9 μM. Furthermore, some of the compounds possessed moderate cytotoxicity against
human breast, lung, cervical and hepatocellular carcinoma cell lines, without showing toxicity for nontumor
liver cells. The above mentioned derivatives represent promising leads for the development of new
generation of sugar-triazole anti fungal agents.This work has been supported by Fundação para a Ciência e a
Tecnologia through grant Nos. PEst-C/EQB/LA0006/2013 and PEst-OE/AGR/UI0690/2014. T.M. Potewar and R.C. Calhelha are grateful
to Fundação para a Ciência e a Tecnologia for their pos-doctoral Grant
Nos. SFRH/ BPD/65173/2009 and SFRH/BPD/68344/2010, respectively.
The authors thank to Serbian Ministry of Education, Science
and Technological Development for financial support (grant number
173032). The NMR spectrometers are part of The National NMR Facility,
supported by Fundação para a Ciência e a Tecnologia
(RECI/BBB-BQB/0230/2012)
Characterization of Children with Auditory Neuropathy Spectrum Disorder and their Rehabilitation
Objectivos: Identificar e caracterizar os casos pediátricos de Distúrbio do Espectro da Neuropatia Auditiva (DENA) e analisar a sua reabilitação.
Desenho do Estudo: Estudo observacional descritivo.
Material e Métodos: Análise dos processos clÃnicos de 671 doentes avaliados em primeira consulta de reabilitação auditiva pediátrica entre 2012 e 2019. Dos 467 casos de hipoacusia sensorioneural, incluÃram-se aqueles que apresentavam PEATC sem resposta ou com resposta marcadamente anormal e OEAs presentes e/ou limiares tonais desproporcionais aos resultados electrofisiológicos. Obtiveram-se 12 casos de
DENA.
Resultados: A prevalência de DENA foi 2,6%. A maioria dos casos apresentou factores de risco para hipoacusia. Os resultados audiométricos foram heterogéneos e flutuantes. Quatro crianças foram reabilitadas com prótese auditiva e três com implante coclear.
Conclusões: O DENA é uma condição rara, associada a vários factores de risco e de diagnóstico e abordagem desafiantes. A reabilitação auditiva tem de ser personalizada e guiada pelo desempenho funcional da criança.info:eu-repo/semantics/publishedVersio
Longer duration of obesity is associated with a reduction in urinary angiotensinogen in prepubertal children
Background: We aimed to study the impact of obesity on urinary excretion of angiotensinogen (U-AGT) in prepubertal children, focusing on the duration of obesity and gender. Also, we aimed to evaluate whether plasma angiotensinogen (P-AGT) and hydrogen peroxide (H2O2) play a role in the putative association.
Methods: Cross-sectional evaluation of 305 children aged 8–9 years (160 normal weight, 86 overweight, and 59 obese). Anthropometric measurements and 24-h ambulatory blood pressure monitoring were performed. Angiotensinogen (AGT) was determined by a commercial enzyme-linked immunosorbent assay (ELISA) kit and H2O2 by a microplate fluorometric assay.
Results: U-AGT and P-AGT levels were similar across body mass index (BMI) groups and between sexes. However, boys who were overweight/obese since the age of 4 years presented lower levels of U-AGT compared with those of normal weight at the same age. In children who were overweight/obese since the age of 4, urinary H2O2 decreased with P-AGT.
Conclusions: A higher duration of obesity was associated with decreased U-AGT in boys, thus reflecting decreased intrarenal activity of the renin–angiotensin system. Also, children with a longer duration of obesity showed an inverse association between urinary H2O2 and P-AGT. Future studies should address whether these results reflect an early compensatory mechanism to limit obesity-triggered renal dysfunction.This project was supported by funds from Fundo Europeu de Desenvolvimento Regional (FEDER) from Programa Operacional Factores de Competitividade – COMPETE (FCOMP-01-0124-FEDER-028751), by national funds from the Portuguese Foundation for Science and Technology (FCT) (PTDC/DTP-PIC/0239/2012) and by Calouste Gulbenkian Foundation, that granted the study design and data collection and analysis. Liane Correia-Costa was supported by FCT (grant SFRH/SINTD/95898/2013), Teresa Sousa was supported by FCT and POPH/FSE (EC) (Ciência 2008 and SFRH/BPD/112005) and Franz Schaefer was supported by the ERA-EDTA Research Programme and the KfH Foundation for Preventive Medicine. The Epidemiology Research Unit (EPIUnit) is funded by FCT (UID/DTP/04750/2013)
Microbial DNA extraction methods for microbial screening - saliva vs biofilm comparison
info:eu-repo/semantics/publishedVersio
SOPHIE velocimetry of Kepler transit candidates XII. KOI-1257 b: a highly eccentric three-month period transiting exoplanet
In this paper we report a new transiting warm giant planet: KOI-1257 b. It
was first detected in photometry as a planet-candidate by the
space telescope and then validated thanks to a radial velocity follow-up with
the SOPHIE spectrograph. It orbits its host star with a period of 86.647661 d
3 s and a high eccentricity of 0.772 0.045. The planet transits the
main star of a metal-rich, relatively old binary system with stars of mass of
0.99 0.05 Msun and 0.70 0.07 Msun for the primary and secondary,
respectively. This binary system is constrained thanks to a self-consistent
modelling of the transit light curve, the SOPHIE radial
velocities, line bisector and full-width half maximum (FWHM) variations, and
the spectral energy distribution. However, future observations are needed to
confirm it. The PASTIS fully-Bayesian software was used to validate the nature
of the planet and to determine which star of the binary system is the transit
host. By accounting for the dilution from the binary both in photometry and in
radial velocity, we find that the planet has a mass of 1.45 0.35 Mjup,
and a radius of 0.94 0.12 Rjup, and thus a bulk density of 2.1
1.2 g.cm. The planet has an equilibrium temperature of 511 50 K,
making it one of the few known members of the warm-jupiter population. The
HARPS-N spectrograph was also used to observe a transit of KOI-1257 b,
simultaneously with a joint amateur and professional photometric follow-up,
with the aim of constraining the orbital obliquity of the planet. However, the
Rossiter-McLaughlin effect was not clearly detected, resulting in poor
constraints on the orbital obliquity of the planet.Comment: 39 pages, 17 figures, accepted for publication in Astronomy &
Astrophysic
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