Descriptive Study of an Outbreak of Avian Urolithiasis in a Large Commercial Egg Complex in Algeria

Avian urolithiasis is one of the major causes of mortality in poultry. However, in Algeria this condition has never been described. An outbreak of avian urolithiasis was observed on a large commercial egg complex in the department of Chlef (West of Algeria). The clinical features of this condition are to be described. Mortality associated to urolithiasis started at the onset of egg production, estimated to 0.7 % per week. Urolithiasis induced an egg drop estimated to 12%. Dead and live layers were both necropsied and examined for kidney lesions. Most of the birds examined presented enlarged ureters, renal atrophy and visceral gout deposition

Electron-ion inverse bremsstrahlung absorption in magnetized fusion plasma

Magneto-inertial fusion (MIF) is an approach for thermonuclear fusion. It consists in applying a strong magnetic field to the inertial-fusion plasma, with the role of the magnetic field being to limit the diffusion of the formed plasma during the impact of an intense laser pulse with a target containing the thermonuclear fuel, as well as the confinement alpha particles produced by the fusion reaction. This allows the reduction of energy loss and improves compression conditions. In this paper we are interested in the study of the electron-ion inverse bremsstrahlung absorption (IBA) of the laser energy in magnetized plasma in the MIF frame. In addition, we apply the derived formula to calculate the absorption in magnetic fusion plasma heated by microwave. We use the Fokker-Planck-Maxwell theory to calculate the IBA explicitly in magnetized plasma. Scaling laws for IBA in MIF plasma and for magnetic confinement plasma are established. The numerical treatment of the model equations shows the influence of the magnetic field and the polarization of the wave on the absorption

Inverse bremsstrahlung absorption in magnetized plasmas

The Magneto-Inertial Fusion (MIF) approach has the benefits of both approaches of Inertial Confinement Fusion (ICF) and Magnetic Confinement Fusion (MCF). MIF is a complete approach, as compared to others. It has the advancement of the common ICF and some advantages over MCF. It also includes high-density plasma in the presence of strong magnetic fields. In this study, we investigate the inverse bremsstrahlung absorption (IBA) in magnetized plasma and the kinetic theory. Many researchers have calculated the inverse bremsstrahlung absorption coefficient through the ICF approach. In this investigation, however, the average of IBA is obtained that can be used in the MIF approach, the kinetic theory and the Krook collision frequency. In addition, the influences of some parameters such as laser wavelength, electron temperature, and static magnetic field are shown on the mean collisional absorption. A numerical solution is also used to calculate the dispersion function and the laser electric field. IBA is one of the basic heating processes in laser fusion plasma. The results of the study show that, in critical layers, the increase of absorption is proportional to short laser wavelength, low electron temperature, but IBA varies slowly with the static magnetic field

Nonlinear inverse bremsstrahlung absorption in magnetized laser-fusion plasma

The nonlinear inverse bremsstrahlung absorption (NLIBA) in magnetized plasma has been investigated within the framework of relativistic kinetic theory. Collisions are described by an improved Krook collision term that accounts for relativistic effects and the Landau microscopic collision form. The non-linearity considered in this paper arises from the anisotropy in electron momentum space in the plasma that is heated by an intense laser pulse. The absorption is explicitly expressed, under reasonable approximations, as a function of the plasma, laser pulse, and magnetic field parameters. Numerical treatment of the model equations shows that absorption increases with laser intensity but decreases with plasma temperature and laser wavelength. It has been shown that the polarization of the laser wave has a significant influence on absorption for high-intense magnetic fields used in magneto-inertial fusion (MIF) experiments. Nonlinear effects clearly reduce absorption for laser intensities comparable to the characteristic intensity, I0=me2c3ε0ωL2/e2, where me is the electron mass, c is the speed of light in vacuum, ɛ0 is the electric permittivity of free space, ωL is the laser wave frequency, and e is the elementary electric charge. Within the intensity I ≪ I0 and laser wavelength in the micro-meter range (λ ∼ μm), relativistic effects appear in the third order of absorption. These findings allow for the optimization of laser pulse parameters to achieve efficient absorption in MIF experiments

A GATE Monte Carlo framework for dosimetric evaluation in mammography in an Algerian hospital

International audienceA framework has been developed for dosimetric evaluation in mammography, using the GATE Monte Carlo (MC) platform, to simulate a MAMMOMAT 3000 Nova mammograph (Siemens) available at the University Hospital Center "1st November 1954" of Oran (EHU Oran 1er Novembre, 1954), Algeria. Calculated quantities such half-value layer (HVL), Entrance Surface Dose (ESD) and Mean Glandular Dose (MGD) have been compared to experimental data in order to validate the modeling of mammography examinations. Results are consistent with previous studies and show a good agreement between measurements and Monte Carlo calculations. By varying the tube voltage from 25 to 35 kV, we have estimated an increasing of a factor of 2.4 in ESD, and a factor of 2.75 for the MGD in a breast phantom. Furthermore, the current intensity of 100 mAs used for a beam quality combination (Mo/Mo) Anode/filter was found suitable for the tube voltages of 25–29 keV since the MGD does not exceed the limits set by the different quality insurance protocols. This GATE dose calculation framework thus provides a very useful tool for the optimization of mammography examinations at Oran hospital by allowing a better estimation of the dose delivered to patients according to the parameters of the examination. •A mammography dose calculation software has been developed for the 1st of November university hospital (EHU, Oran, Algeria).•This tool is based on a GATE/GEANT4 Monte Carlo platform, validated with a series of experimental measurements (HVL, doses).•Technical parameters of the MAMMOMAT-3000 device were considered in the calculations, as well as clinical protocol.•Main results on HVL (Half Value Layer), and ESD (Entrance Surface Dose)/MGD (Mean Glandular Dose) are presented