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Resume Cet article examine les facteurs d’entree et de sortie de la prostitution, ainsi que les interventions visant le soutien des femmes desirant quitter le monde prostitutionnel. Malgre la diversite des trajectoires menant a l’industrie du sexe, la prostitution est fortement liee a des problemes psychologiques, familiaux, sociaux et/ou economiques. Ces facteurs maintiennent les femmes dans la prostitution et complexifient le processus de sortie. Il est imperatif, en ce sens, d’etablir une comprehension permettant de saisir les mecanismes d’entree et de sortie de la prostitution afin de mieux cibler les interventions en matiere de prevention et mieux soutenir les femmes desirant quitter la prostitution. Une recherche, a partir de plusieurs bases de donnees, a permis de selectionner 21 etudes portants sur les mecanismes d’entrees, de sortie et sur les interventions. Les etapes de la demarche de recension des ecrits sont inspirees de la demarche du Centre for Reviews and Dissemination de l’universite de York (2008). Les resultats montrent que l’entree dans la prostitution est la consequence de facteurs multiples et la sortie necessite un processus complexe qui exige plusieurs tentatives. Certains programmes d’interventions ne repondent pas a des besoins specifiques aux femmes prostituees.

This work presents the study of the improving air navigation at chlef aerodrome by Implementing a new Instrument Landing System (ILS). At present, the radio navigation systems at Chlef aerodrome can handle the air traffic load adequately(air traffic controllers are able to manage the airspace for which they are responsible). Nevertheless, in the very near future the traffic load will become so important that it will require the implementation of an ILS beacon. To this reason, we will study the current situation, which is based on a general presentation of Chlef aerodrome (the situation and position of the airspace, and the existing airport infrastructure), followed by the choice of equipment to be installed and the method of implanting the ILS system (composition, technical characteristics and arrangements), in accordance with standards and recommended practices. From these results we can find: Implementation of glide path (GP) on the runway26, implementation of the localizer on the runway 26, setting a new equipment DME. The previous systems contribute largely for improving the air navigation at the aerodrome of Chlef.

International audience; One of the major challenges in wireless communication technologies is the antenna design. In this paper, a wide-band flexible antenna made by covering a Kapton substrate with a flexible magnetodielectric polymer-based nanocomposite layer is proposed. This novel magnetodielectric polymer-based nanocomposite relies on carbon-coated cobalt (CCo) and is coated with a conjugated polymer, polyaniline (PANI). The nanocomposite (PANI/CCo) fabrication, whose morphology was studied via scanning electron microscopy, demonstrates a relative permeability, a dielectric permittivity, and a conductivity of 5.5, 4.3, and 7500 S/m, respectively. In this paper, two frequency bands are of interest [1.8-2.45 GHz (personal communication service and wireless local area network) and 5.15-5.825 GHz (wireless networks)]. The functioning of the antenna in free space and on body is numerically and experimentally investigated. The average specific absorption rate is also discussed. Thanks to its performance this magnetodielectric nanocomposite polymer (PANI/CCo) antenna has been found to be a good candidate for wearable applications where complex bending situations are encountered.

International audience; New generations of printed flexible antennas are playing an important role in wireless communication systems. The ultra wide band and wearable possibilities are critical aspects of these kinds of antennas. In this study, the proposed antenna is an elliptical monopole fed by a coplanar waveguide; it uses a kapton substrate and it is optimised to work from 1 to 8GHz. In the case of copper, a conductive nanocomposite material based on a polymer (polyaniline: PANI) and charged by multiwalled carbon nanotubes (MWCNTs) is exploited. The flexibility of both the kapton substrate and the nanocomposite (PANI/MWCNTs) provides the ability to crumple the antenna paving the way to potential applications for body-worn wireless communications systems. In this study, the performance of the antenna is investigated in terms of return loss, radiation patterns and gain for both crumpled and uncrumpled antennas. The results confirm that performance remains at a good level when the antenna is crumpled.

This study is a kinematic model of a mechanical mill that works with a single ball in motion, and which is operated by a crank and connecting rod system for producing nanocrystalline powders by the process of ball milling. The geometric and dynamic parameters play an important role on the variation of forces created upon impact of the ball with the inside wall of the vial, which caused energy transfer required for the mechanical alloying process. The determination of these forces enables us to know their specific magnitudes on the intensity and milling efficiency, with the advantage of low operating power consumption of the mill and absence of the contamination problem. In addition, we have defined a model for calculating the temperature of the powder trapped between the ball and the wall of the vial of the mechanical mill whose start-up is provided by an electric motor.

International audience

The work we have undertaken consists of preparing nanocrystalline Fe40Co60 powders by the Mechanical Alloying (MA) route. Characterization of obtained powders was applied on two steps. First, structural properties were investigated. X-ray Diffraction (XRD) was used to identify the formation of a disordered α (Fe40Co60) solid solution with a bcc lattice after 60h milling. By the Halder-Wagner approach lattice size, average grain size and residual strain were fixed. The morphology of milled powders was investigated by Scanning Electron Microscopy (SEM). Then bulk specimens were prepared by cold compaction for microwave measurements. Microwave dielectric permittivity and conductivity were determined using cavity perturbation technique. Microwave absorbing characteristic was measured according to line transmission method. Results obtained confirm that the developed structure after milling is the main factor that influences the microwave properties of nanocrystalline Fe40Co60 powders compared to elemental Fe.

Iron-Cobalt (Fe-Co) ferrite nanocrystalline materials have been widely applied in microwave and radio frequency devices, such as circulators. Magneto-dielectric nanocrystalline were synthesized by mechanosynthesis (high energy mechanical grinding). Samples were taken at different grinding times. Toroidal samples were made by compact method at room temperature. In this work, the effect of mechanosynthesis time on complex dielectric properties were systematically investigated. The extraction of the complex dielectric constant is made on a large frequency range [8–12] GHz. The behavior of the compacted samples exposed to an electromagnetic field (band X) was studied using a cylindrical resonant cavity associated with a network analyzer. The measurement results demonstrate that the proposed Fe-Co ferrite material is available to be used in microwave circulators due to its mean dielectric constant and its low loss tangent.

International audience; The new generation of polymer materials has the facility to conduct electricity, radiate and concurrently be flexible. Accordingly, the possibility of implementation of a flexible antenna opens the door to many interesting applications including body-worn ones. This paper presents the design of a CPW-fed monopole antenna, based on a Carbon coated Cobalt (CCo) charged Polyaniline (PANI). A wideband antenna design approach is proposed to develop a single antenna that can be employed by diverse wireless technologies. In particular, in this paper the frequency bands of interest are [2.4-2.48] GHz (WiFi) and [5.15-5.825] GHz (wireless networks). Conception, realization and characterization steps of the composite based wideband antenna are presented. The composite (PANI/CCo) fabricated, whose morphology was studied via scanning electron microscopy, has a conductivity of 7500 S/m. The antenna is printed on a 130pm thick Kapton® substrate. A good agreement between measurements and simulation data is observed. © 2017 IEEE.

International audience; The main objective of a dual bell nozzle is the enhancement of performances based on the principle of auto-adaptation in accordance with the altitude. Indeed, this system has as advantage the auto-adaptation of the flow for two operating modes (at low and high altitude) without mechanical activation. The principle is theoretically simple but structural forces involved can be significant. In this study, a numerical method for the design of this type of nozzle is developed. On the one hand, it is based on a transonic flow approaches to define the starting line on which the supersonic calculations will be initiated. On the other hand, the method of characteristics is used to draw the base nozzle profile. Knowing that the latter is assimilated as a polynomial of the second degree, its constants are calculated from initial conditions. In order to minimize the weight of this nozzle, its truncation proves necessary; this is performed at a point where the best compromise (weight / performances) was respected. The profile of the second curve is calculated to give a constant wall pressure. This is achieved by using the direct method of characteristics applied for a centered expansion wave that the intensity is P2/P1 at the junction. Once the profile is generated, an analysis of the thermodynamic-parameters evolution (such as: pressure, Mach number) and aerodynamic performances is conducted. For more consistency, our results are compared with numerical databases of ONERA nozzle. Simulations of flow in the nozzle with Ansys 13.0 environment for different types of meshes are presented. Also, to offset the effects of the boundary layer, the simulations were performed by using the k-ω SST turbulence model. The obtained results by the method of characteristics and numerical simulation are compared to the computed results of the literature and it was found good agreement and similarity.

A new approach to estimate wind velocity and spectral width for weather radar is presented. In this paper, we deal with spectrum estimation and moments estimation of the received signal with a phased array Doppler weather radar. The lifted wavelet transform is applied on the estimated power spectral density prior to estimate the wind features (velocity, direction, spectral width). We apply the soft thresholding strategy on the lifted wavelet transform coefficients using the well-known minimax threshold as first guess. We estimate the velocity and the corresponding spectral width. We, iteratively, threshold the detail signal, in the wavelet domain, using an incremented threshold value until we obtain (using a stopping test) the optimal value of the initial threshold (minimax). In the first stage of the work, we have chosen a radar model used for meteorology to generate synthetic data on which we applied our algorithm. In the second stage, we used actual data got from the real radar that we used as model. The probative results we got with synthetic data are strengthened by the results obtained by the actual data.

In recent years composite materials are widely used in the aerospace industry. The advantages of these materials are derived from their high strength, rigidity and lightness. More importantly, they have the potential to reduce the cost of construction, while improving structural reliability and increasing safety. Aircraft structural parts made of composite materials with polymeric matrix, subject to variables conditions and severe environments, require a good knowledge of their behavior under humidity and temperature. The matrix is very sensitive to these parameters. A degradation of properties is then observed [1-1.

International audience; In this study, a patch antenna including a thick film made of a composite material based on Polyaniline (PANI) and Carbon coated Cobalt (CCo) is investigated. Conception, simulation, realization and characterization steps are presented. The morphology of the obtained composite was studied via scanning electron microscopy. The conductive polymer (PANI/CCo) fabricated has a conductivity of 7500 S/m. The antenna is designed to operate at the frequency of 4.5 GHz and the dielectric substrate used is Rogers RT/Duroid® 5870. A good agreement is observed between measurements and simulation data. The experimental results show an antenna gain of 4.6 dB for a PANI/CCo film thickness of 70 μm. © 2016 European Association of Antennas and Propagation.

International audience; This study presents the conception, simulation, realisation and characterisation of a patch antenna made of a composite based on polyaniline (PANI) and multiwall carbon nanotubes (MWCNTs). The antenna is designed to operate at the frequency of 4.5 GHz; the dielectric substrate used is Rogers RT/Duroid® 5870 which has a dielectric permittivity of 2.33 and a loss tangent of 0.0012. The conductive polymer (PANI/MWCNTs) fabricated has a conductivity of 4500 S/m. The performance of the proposed antenna is investigated as a function of the thickness of the conductive polymer. The experimental results show an antenna gain of 5.18 dB for a PANI/MWCNTs thickness of 110 μm. The results obtained suggest that this kind of conductive polymers are good candidates for future applications based on organic electronics.

In this work, we study the synthesis of Fe-Co powders via planetary ball milling with different particle sizes. The morphology is a factor that influences the microwave properties of materials. The prepared samples are characterized using X-ray powder diffraction (XRD), scanning electron microscopy (SEM), X-band wave guide and resonator cavity associated with network analysis. The microwave-absorbing characteristic effects are investigated in a frequency range 8.5–10.5 GHz using network analyser. They enhanced between 0 and 54 h of milling time with an increase in the relative dielectric permittivity (ε'r).

International audience; In this paper, a fully organic dual-band antenna is presented. It consists of a coplanar waveguide coupled to an elliptical monopole antenna designed on a kapton substrate. This antenna is fabricated from a process, based on the use of a conductive polymer (Polyaniline) doped with multiwall carbon nanotubes, that has been optimized for this application. The flexibility of both, kapton substrate and doped conductive polymer, gives the antenna the ability to be freely crumpled paving the way to body-worn high data rate communications at microwave frequencies. Applications in wireless networks can also be addressed by using this kind of antennas. In this study, a comparison between the performance of an antenna under bending conditions (using a 3D support) and its uncrumpled version is presented. We evaluate the crumpling effect on the resonant frequency, the bandwidth and the radiation patterns. A good agreement is observed between measurements and simulations data, even when the antenna is crumpled.

Nanocrystalline Fe72Al28 alloy samples were prepared by mechanical alloying process using planetary high-energy ball mill. The alloy formation and different physical properties were investigated as a function of milling time, t, (in the 0-24 h range) by means of X-ray diffraction technique, scanning electron microscopy (SEM), energy dispersive X-ray, and Mossbauer spectroscopy. The complete formation of bcc-FeAl solid solution was observed after 4 h of milling. The lattice parameter quickly increased to a maximum value of 0.291 nm within the first hours of 12 h of milling, then decreased to a value of 0.2885 nm after 24 h. The grain size decreased from 55 to 10 nm, while the strain increased from 0.18 to 0.88%. Grain morphologies at different formation stages were observed by SEM. The Mossbauer spectrum showed the presence of a singlet and sextet after 4 h of milling. The singlet indicated the presence of paramagnetic phase characteristic of A2 disordered structure and the sextet with a mean hyperfine field, 〈H hf〉, of 21 T was indicative of ordered DO3 structure. After 8 h of milling, the paramagnetic phase disappeared allowing the appearance of a sextet. For the higher milling time, i.e., 24 h, the Mossbauer spectrum was analyzed with two components. The first with 〈H hf〉 equal to 29.9 T and the second with a 〈H hf〉 value of 10.25 T.

In this work we report on the structural, mechanical and magnetic properties of mechanically alloyed Fe40Co60 powders. Alloying formation, grain size, lattice parameter and internal strain were investigated using X-Ray Diffraction (XRD) measurements. The morphological aspect of the nanostructured powders was analysed by means of the Scanning Electron Microscopy (SEM). Compacted pastilles with circular shape have been under Vickers test of micro Hardness and magnetic measurements of Hysterisis loops. Discussed results according to milling time show that after 60 h milling the grain refinement is about 15.59 nm with internal strain of around 0.5809 %. The micro hardness increases with the decrease of the grain size and the hysterisis loop at 60 h milling is enhanced in term of decreased coercivity.

Nanocrystalline Fe72Al28 alloy samples were prepared by the mechanical alloying process using planetary high-energy ball mill. The alloy formation and different physical properties were investigated as a function of milling time, t, (in the 0-24 h range) by means of the X-ray diffraction (XRD) technique, scanning electron microscopy (SEM), energy dispersive X-ray (EDAX) and Mössbauer spectroscopy. The complete formation of bcc-FeAl solid solution is observed after 4 h of milling. The lattice parameter, a (nm), quickly increases within the first hours of milling and reaches a maximum value of 0.291 nm at 12 h of milling time; then a (nm) decreases to a value of 0.2885 nm for 24 h. The grain size decreases from 55 to 10 nm, while the strain increases from 0.18% to 0.88%. Grain morphologies at different formation stages were observed by SEM. The Mössbauer spectra show different behaviors with the increase of milling time. Indeed, after 4 h, the Mössbauer spectrum shows the presence of a singlet and sextet. The singlet indicates the presence of paramagnetic phase characteristic of A2 disordered structure and the sextet with a mean hyperfine field, , of 21 T is indicative of ordered DO3 structure. After 8 h of milling, the paramagnetic phase disappears leading to the appearance of a sextet, with a mean hyperfine field, Hhf, equal to 24.18 T which is characteristic of DO3’ structure. For the higher milling time i.e. 24 h, the Mössbauer spectrum was analyzed with two components. The first one with equal to 29.9 T is still indicative of ordered DO3, however, the second with a value of 10.25 T is characteristic of the fine domain B2 ordered structure.

This study aims to corroborate experimental studies in mechanical alloying by theoretical studies, particularly the calculation of the contact temperature at the impact point of the balls, basing on the mathematical model of a compact powder between two colliding balls. Indeed, within this study, we show the influence of some geometrical, dynamic, and thermophysical parameters on the variation in the contact temperature of balls and Al and Ti powders inside a vial of planetary ball mill.

Fe60Co40 and Fe72Al28 nano-alloys were synthesized from elemental powders via highenergy mechanical alloying. The prepared samples were characterized using X-ray diffraction, scanning electron microscopy and X-band waveguide to measure the reflection loss in a frequency range of 9-10 GHz. The XRD patterns show that disordered Fe60Co40 solid solution with a bodycentred cubic structure is formed for milling times longer than 12 h, and after 4h milling, the solid solution Fe72Al28 has been largely formed. Morphological studies indicate an average grain size of 10 to 15 nm. The microwave- absorbing characteristic reveal good performance for Fe60Co40 compared to Fe72Al28, the maximum reflection loss is about -12 dB for the absorber.

We analyzed nanostructured Fe 60 Co 40 alloy obtained by mechanical alloying using a planetary ball mill. The prepared powders were characterized using X-ray Diffraction (XRD), Laser particle-measurement, scanning electron microscopy (SEM), X band waveguide and cavity resonator associated with Network analyzer. Obtained results are discussed according to milling time. XRD patterns show after 12 h of milling the formation of a disordered solid solution having body-centerd cubic (bcc) structure. After 36 h milling, morphological studies indicated that the average crystallites size is around 13 nm and the particles average diameter is about 3.6 μm. The microwave absorbing characteristic was enhanced between 0 and 54 h of milling (from −0.8 to −13.807 dB) with decreasing in the relative dielectric permittivity e r .

The Fe60Co40 alloys were prepared by mechanical alloying of the Fe and Co powders using a high-energy ball mill. They were studied with respect to phase formation and magnetic properties using x-ray diffraction, scanning electron microscopy, and measurements of coercivity and remanence (Br). The evaluation of Fe lattice parameters during milling showed that formation of a body-centered cubic solid solution occurred by mechanical alloying after 12 h of milling. Intensive milling of Fe-Co powders results in a nonequilibrium microstructure characterized by grain refinement to a minimum of 10–13 nm and the introduction of internal strain up to 0.5%.

In the civilian aviation field, the radar detection of hazardous weather phenomena (winds) is very important. This detection will allow the avoidance of these phenomena and consequently will enhance the safety of flights. In this work, we have used the wavelets method to estimate the mean velocity of winds. The results showed that the application of this method is promising compared with the classical estimators (pulse pair, Fourier)

It is extremely rare that an inflammatory rheumatism reveals a hyperthyroidism. Only six observations have been described. We report a case of rheumatismal hyperthyroidism successfully treated with carbimazole and propranolol.A 52 year-old woman presented with inflammatory rheumatismal pain predominating at the waist for the past six months and resistant to synthetic anti-inflammatories. Thyroid hormone analysis permitted diagnosis of hyperthyroidism. Initiation of treatment with carbimazole led to the rapid regression of the rheumatismal manifestations.Hyperthyroidism is classically manifested by signs of hypercatabolism. Osteoarticular manifestations are dominated by humeroscapular periarthrosis. Rheumatismal hyperthyroidism is characterised by inflammatory rheumatismal pain evoking, as in our patient, a rhizomelic pseudo-polyarthritis. The outcome, whatever the anti-thyroid treatment, is always good. The physiopathological mechanisms are unknown. They may be due to an attack of the antibodies against the synovial and/or cartilage structures, or to the effect of propranolol.It is important to underline the interest of thyroid hormone assay in cases of dubious etiological inflammatory rheumatism and/or resistant to classical treatments.

Fe40Co60 powders were produced by mechanical Alloying (MA) route. Structural and microwave dielectric properties were investigated. Discussion of obtained results is conducted according to milling time. X-Ray powder Diffraction (XRD) shows that disordered α (Fe40Co60) solid solution of substitution with body centered cubic (bcc) lattice is formed after 2h milling. Halder Wagner analysis reveals that least grain size of 15.59 nm and residual strain up to 0.8% are reached after 60h milling. The evolution of the Voigtian mixing factors according to milling progression confirms that structural properties are governed by residual strain accumulated during high- energy mechanical alloying (Gaussian profiles). Scanning Electron Microscopy (SEM) indicates that obtained powders adopt flattened angular shapes with high surface area. Microwave measurements are undertaken on bulk samples. High values of the dielectric permittivity depicting the conductive behavior of Fe-Co powders are measured. Dielectric permittivity spectra according to milling time shift towards higher values. Enhancement of the dielectric properties is related to the developed structure after milling.

Pulmonary hypertension is an uncommon feature of Whipple's disease and the underlying pathophysiological mechanism remains a subject of debate.A 57-year-old woman was hospitalized for exploration of migrating joint pain that had developed for 5 years. Histologically proven Whipple's disease was diagnosed on duodenal biopsies. The lung angiogram performed to explore signs of right heart failure demonstrated pulmonary hypertension and ruled out pulmonary embolism. Abundant pericardial effusion developed progressively. Antibiotic therapy using sulfamethoxazole-trimethoprime led to a systemic Jarisch Herxheilmer reaction. The pulmonary hypertension resolved rapidly, the pericardial effusion more slowly.The pulmonary hypertension in this patient appeared to be directly related to Whipple's disease, probably via vascular infiltration by Tropheryma whippeli.

We report the case of a 52-year-old woman who presented hypoparathyroidism and sarcoidosis. The hypoparathyroidism developed 8 years after the diagnosis of sarcoidosis. No element in favor of an autoimmune disease of the parathyroid could be evidenced. Pathology and immunology blood tests were equally noncontributive. Another pathophysiological mechanism, possibly sarcoidic granulomatous infiltration of the parathyroid glands, was suspected. The patient also presented apparently coincidental vitiligo.

Vitamin B1 deficiency (beriberi) is very uncommon in France. It leads to high output cardiac failure totally different from the situation observed in alcoholic patients. We report a typical case of cardiac beriberi.The patient was referred for dyspnea with high output cardiac failure. Echocardiography evidenced severe pulmonary hypertension and high cardiac output. The more common causes of heart failure were ruled out. The dietary habits of the patient (suggested beriberi which was confirmed by the low serum thiamin and therapeutic test with vitamin B1.High output cardiac failure should suggest possible Shoshin beriberi, particularly in subjects with imported dietary habits living in a precarious socioeconomic situation.

Nanocrystalline Fe(1−x)Cox, Fe, Fe80N120,Cu70Fe18Co12 mixtures have been prepared by mechanical alloying using a planetary ball mill under several milling conditions. Their structures and magnetic properties were investigated. Mechanical alloying is a non-balanced process for synthesis materials. The structural effects of mechanical alloying of powders were investigated by scanning X-ray diffraction analysis. In this report, we examine the applicability of eddy current techniques in-process for monitoring of powder density particle size and the time necessary to structure variation. An eddy current based monitoring system developed to measure metal powder density is expanded for monitoring metal powder diameter in metal compounds. Experimental sensor readings were gathered using four different metal powders with known particle sizes Fe(1−x)Cox, Fe, Fe80N120 and Cu70Fe18Co12. Analysis of the data showed that the sensor output was in relation with different parameter of powder (diameter, density and structure) that the sensitivity of the sensor differed with the type of metal powder. The merit of this technique is its reliance on a simple and inexpensive sensor probe.

Mechanical alloying is a powder metallurgy processing technique involving the cold welding, fracturing and rewilding of powder particles in high energy. It has been used to obtain nanocrystalline alloys. Fe-20 wt. % Ni alloys were synthesised using a planetary ball mill (Retsch PM400). X-ray Diffraction (XRD) was used to identify and characterise various phases during the milling process. It is shown that the bcc Fe(Ni) solid solution was formed after 2 h of milling. The steady state grain size is about 12 nm. Many nanostructures' magnetic materials have exhibited excellent soft magnetic properties, which suit so many applications. We used electromagnetic methods (hysteresis) to characterise the variation of the residual magnetisation and the coercive field.

In this paper, the structure and magnetic properties of nanocrystalline Fe(1–x)Cox mixtures are investigated. These structures are prepared using mechanical alloying based on planetary ball mill under several milling conditions. The structural effects of mechanical alloying of powders were investigated by scanning electron microscopy, X-ray diffraction analysis and bench of microwaves. Consequently, alloy powder with an average grain size of 10–13 nm was obtained. Maximum saturation magnetisation Ms was obtained at a composition value of 65% Co. Microwave measurements were performed on the mechanically milled Fe(1–x)Cox powder.