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Search Results: 1 - 10 of 138719 matches for " K. Moudden "
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Pseudotumoral Abdominal Tuberculosis in Immunocompetent Adults: Report of Three Cases and Review of the Literature  [PDF]
T. Lamsiah, A. Zinebi, Y. Touibi, K. Moudden, N. Lahmidani, B. Zainoun, M. El Baaj
Journal of Tuberculosis Research (JTR) , 2017, DOI: 10.4236/jtr.2017.51003
Abstract: Purpose: To highlight diagnostic challenges of pseudotumoral abdominal tuberculosis. Materials and methods: Three cases of pseudotumoral abdominal tuberculosis were compiled in our department between 2014 and 2015. They were aged 34 years, 42 years and 61 years respectively. They were immunocompetent and had no personal or family history of tuberculosis. Clinical presentations were non-specific, represented by abdominal pain and weight loss in the three patients and chronic diarrhea in one patient. Abdominal ultrasound and computed tomography CT were performed in all patients. Abdominal MRI was performed in one case as well as a colonoscopy. Results: Retroperitoneal tuberculosis and colic tuberculosis were noted in the 1st and 2nd case. Macro-nodular and biliary hepatic tuberculosis was retained in the third case. The diagnosis was based upon histopathology in the 3 cases showing tubercular granuloma with caseation. Anti-tuberculosis therapy was prescribed for 6 months. Evolution was favorable in all patients. Conclusion: Tuberculosis continues to present diagnostic difficulties, particularly in its pseudo-tumoral form, even in endemic tuberculosis countries like ours.
Polarized wavelets and curvelets on the sphere
J. L. Starck,Y. Moudden,J. Bobin
Physics , 2009, DOI: 10.1051/0004-6361/200811343
Abstract: The statistics of the temperature anisotropies in the primordial cosmic microwave background radiation field provide a wealth of information for cosmology and for estimating cosmological parameters. An even more acute inference should stem from the study of maps of the polarization state of the CMB radiation. Measuring the extremely weak CMB polarization signal requires very sensitive instruments. The full-sky maps of both temperature and polarization anisotropies of the CMB to be delivered by the upcoming Planck Surveyor satellite experiment are hence being awaited with excitement. Multiscale methods, such as isotropic wavelets, steerable wavelets, or curvelets, have been proposed in the past to analyze the CMB temperature map. In this paper, we contribute to enlarging the set of available transforms for polarized data on the sphere. We describe a set of new multiscale decompositions for polarized data on the sphere, including decimated and undecimated Q-U or E-B wavelet transforms and Q-U or E-B curvelets. The proposed transforms are invertible and so allow for applications in data restoration and denoising.
Use of Ultrasonics for the Quality Assessment of Frying Oil
Driss Izbaim,Bouaazza Faiz,Ali Moudden,Naima Taifi,Adil Hamine
International Journal of Systems Signal Control and Engineering Application , 2012,
Abstract: The main objective of this study is to evaluate quality changes of Soybean Oil (SBO) during frying. Traditional methods are expensive and time consuming techniques, requiring technical personnel and laboratory facilities. Fatty Acids (FA) value, total Polar Component (PC) and Free Fatty Acids (FFA) of oil samples were used as chemical indicators of different quality levels of oil and then compared with ultrasonic measurements. The study demonstrated that using ultrasonic properties, we obtain reliable results to monitor and control oil quality.
Study of the Characteristics and Computation Analysis Results of Electromechanical Systems Models
Berdai Abdelmajid,Abdelhadi El Moudden,Chornyi O.P.
International Journal of Information Technology and Computer Science , 2011,
Abstract: Today, simulation of electrical drives with asynchronous motors based on systems of differential equations is regarded as one of the principal means of their research study. The difficulty of the simulation is determined by the need for accuracy of the results obtained and the complexity of the mathematical model’s differential equations. In this article, we present a study of the particularities of the simulation of electrical drives systems with asynchronous motors. We have studied models composed of three-phase and orthogonal coordinates systems and we have shown that qualitative and quantitative differences exist in the process of changing the angular speed of the rotor and electromagnetic torque. The result obtained is above all influenced by the non-linear character of the load opposing a fan-type or “dry friction”-type resistant torque. For dual-earthed electromagnetic actuation with the moments of the resistant torques indicated, integration of differential equation systems was carried out with various digital methods used in professional mathematical software for simulation.
Evaluation of the performance of Frying Oils using an ultrasonic technique
Izbaim, D.,Faiz, B.,Moudden, A.,Taifi, N.
Grasas y Aceites , 2010, DOI: 10.3989/gya.087709
Abstract: The performance of unhydrogenated soybean oil (USBO) and partially hydrogenated soybean oil (PHSBO) was evaluated by comparing their frying stability. Ultrasonic velocity was used to evaluate the oils. Measurements of free fatty acids (FFA) and total polar compounds (TPC) are typical indexes of oil degradation. Oils were heated at 180 °C for periods of 8 h per day for 4 consecutive days. The results from the ultrasonic analyses show different influences of thermo-oxidation on USBO and PHSBO. The ultrasonic measurements had strong correlations with chemical changes. Consequently, the ultrasonic method is useful to obtain information on the quality of the used frying oils. La eficacia de aceites de soja sin hidrogenar (USBO) y aceites de soja parcialmente hidrogenado (PHSBO) fue evaluada por comparación de sus estabilidades de fritura. La velocidad ultrasónica fue usada para evaluar los aceites. La medida de ácidos grasos libres (FFA) y compuestos polares (TPC) son típicos índices de degradación de aceites. Los aceites fueron calentados a 180 °C en periodos de 8 h por día durante 4 días consecutivos. Los resultados del análisis ultrasónico muestran diferentes influencias de termooxidación en USBO y PHSBO. Las medidas ultrasónicas tuvieron una fuerte correlación con cambios químicos. Consecuentemente, el método ultrasónico es útil para obtener información en la calidad de aceites de fritura usados.
First evidence for a gravitational lensing-induced echo in gamma rays with Fermi LAT
A. Barnacka,J-F. Glicenstein,Y. Moudden
Physics , 2010, DOI: 10.1051/0004-6361/201016175
Abstract: Aims. This article shows the first evidence for gravitational lensing phenomena in high energy gamma-rays. This evidence comes from the observation of a gravitational lens induced echo in the light curve of the distant blazar PKS 1830-211. Methods. Traditional methods for the estimation of time delays in gravitational lensing systems rely on the cross-correlation of the light curves of the individual images. In this paper, we use 300 MeV-30 GeV photons detected by the Fermi-LAT instrument. The Fermi-LAT instrument cannot separate the images of known lenses. The observed light curve is thus the superposition of individual image light curves. The Fermi-LAT instrument has the advantage of providing long, evenly spaced, time series. In addition, the photon noise level is very low. This allows to use directly Fourier transform methods. Results. A time delay between the two compact images of PKS 1830-211 has been searched for both by the autocorrelation method and the "double power spectrum" method. The double power spectrum shows a 3 {\sigma} evidence for a time delay of 27.5 $\pm$ 1.3 days, consistent with the result from Lovell et al. (1998). The relative uncertainty on the time delay estimation is reduced from 20% to 5%.
Blind Component Separation in Wavelet Space: Application to CMB Analysis
Moudden Y,Cardoso J-F,Starck J-L,Delabrouille J
EURASIP Journal on Advances in Signal Processing , 2005,
Abstract: It is a recurrent issue in astronomical data analysis that observations are incomplete maps with missing patches or intentionally masked parts. In addition, many astrophysical emissions are nonstationary processes over the sky. All these effects impair data processing techniques which work in the Fourier domain. Spectral matching ICA (SMICA) is a source separation method based on spectral matching in Fourier space designed for the separation of diffuse astrophysical emissions in cosmic microwave background observations. This paper proposes an extension of SMICA to the wavelet domain and demonstrates the effectiveness of wavelet-based statistics for dealing with gaps in the data.
The topological second-level trigger of the H.E.S.S. phase 2 telescope
Y. Moudden,A. Barnacka,J-F. Glicenstein,P. Venault,D. Calvet,M. Vivier,G. Fontaine
Physics , 2010, DOI: 10.1016/j.astropartphys.2010.12.003
Abstract: H.E.S.S is an array of atmospheric Cherenkov telescopes dedicated to GeV-TeV gamma-ray astronomy. The original array has been in operation since the beginning of 2004. It is composed of four 12-meter diameter telescopes. The installation of a fifth 28-meter diameter telescope is being completed. This telescope will operate both in stereoscopic mode and in monoscopic mode i.e. without a coincident detection on the smaller telescopes. A second-level trigger system is needed to supress spurious triggers of the 28-meter telescope when operated in monoscopic mode. This paper gives the motivation and principle of the second-level trigger. The principle of operation is illustrated by an example algorithm. The hardware implementation of the second level trigger system of H.E.S.S. phase 2 is described and its expected performances are then evaluated.
A Study of Carbon Substitutions in MgB_2 within the two-band Eliashberg theory
G. A. Ummarino,D. Daghero,R. S. Gonnelli,A. H. Moudden
Physics , 2004, DOI: 10.1103/PhysRevB.71.134511
Abstract: We study the effects of C substitutions in MgB_2 within the two-band model in the Eliashberg formulation. We use as input the B-B stretching-mode frequency and the partial densities of states N_{sigma}(EF) and N_{pi}(EF), recently calculated for Mg(B_{1-x}C_{x})_2 at various x values from first-principles density functional methods. We then take the prefactor in the Coulomb pseudopotential matrix, mu, and the interband scattering parameter, Gamma^{sigma pi}, as the only adjustable parameters. The dependence on the C content of Tc and of the gaps (Delta_{sigma} and Delta_{pi}) recently measured in Mg(B_{1-x}C_{x})_2 single crystals indicate an almost linear decrease of mu on increasing x, with an increase in interband scattering that makes the gaps merge at x=0.132. In polycrystals, instead, where the gap merging is not observed, no interband scattering is required to fit the experimental data.
Structure and Spin Dynamics of La$_{0.85}$Sr$_{0.15}$MnO$_3$
L. Vasiliu-Doloc,J. W. Lynn,A. H. Moudden,A. M. de Leon-Guevara,A. Revcolevschi
Physics , 1998, DOI: 10.1103/PhysRevB.58.14913
Abstract: Neutron scattering has been used to study the structure and spin dynamics of La$_{0.85}$Sr$_{0.15}$MnO$_3$. The magnetic structure of this system is ferromagnetic below T_C = 235 K. We see anomalies in the Bragg peak intensities and new superlattice peaks consistent with the onset of a spin-canted phase below T_{CA} = 205 K, which appears to be associated with a gap at q = (0, 0, 0.5) in the spin-wave spectrum. Anomalies in the lattice parameters indicate a concomitant lattice distortion. The long-wavelength magnetic excitations are found to be conventional spin waves, with a gapless (< 0.02 meV) isotropic dispersion relation $E = Dq^2$. The spin stiffness constant D has a $T^{5/2}$ dependence at low T, and the damping at small q follows $q^4T^{2}$. An anomalously strong quasielastic component, however, develops at small wave vector above 200 K and dominates the fluctuation spectrum as T -> T_C. At larger q, on the other hand, the magnetic excitations become heavily damped at low temperatures, indicating that spin waves in this regime are not eigenstates of the system, while raising the temperature dramatically increases the damping. The strength of the spin-wave damping also depends strongly on the symmetry direction in the crystal. These anomalous damping effects are likely due to the itinerant character of the $e_g$ electrons.
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