Cutaneous tuberculosis (scrofuloderma) in a five year-old boy: Case report

Cutaneous tuberculosis (CTB) is a rare form of extrapulmonary TB in our region. The incidence of CTB seems to be increasing in some countries. CTB continues to be one of the most elusive and difficult diagnoses to make for dermatologists practicing in developing countries. We report the case of a five-year-old boy with an infected discharging ulcer on his face referred to our hospital in Gorgan, north of Iran. After physical, pathological and radiological examination, the diagnosis of CTB was confirmed. The condition improved after standard antitubercular regimen

Pulsed Plasma Accelerator Modeling

This report presents the main results of the modeling task of the PPA project. The objective of this task is to make major progress towards developing a new computational tool with new capabilities for simulating cylindrically symmetric 2.5 dimensional (2.5 D) PPA's. This tool may be used for designing, optimizing, and understanding the operation of PPA s and other pulsed power devices. The foundation for this task is the 2-D, cylindrically symmetric, magnetohydrodynamic (MHD) code PCAPPS (Princeton Code for Advanced Plasma Propulsion Simulation). PCAPPS was originally developed by Sankaran (2001, 2005) to model Lithium Lorentz Force Accelerators (LLFA's), which are electrode based devices, and are typically operated in continuous magnetic field to the model, and implementing a first principles, self-consistent algorithm to couple the plasma and power circuit that drives the plasma dynamics

Electrical conductivity of plasmas of DB white dwarf atmospheres

The static electrical conductivity of non-ideal, dense, partially ionized helium plasma was calculated over a wide range of plasma parameters: temperatures $1\cdot 10^{4}\textrm{K} \lesssim T \lesssim 1\cdot 10^{5}\textrm{K}$ and mass density $1 \times 10^{-6} \textrm{g}/\textrm{cm}^{3} \lesssim \rho \lesssim 2 \textrm{g}/\textrm{cm}^{3}$. Calculations of electrical conductivity of plasma for the considered range of plasma parameters are of interest for DB white dwarf atmospheres with effective temperatures $1\cdot 10^{4}\textrm{K} \lesssim T_{eff} \lesssim 3\cdot 10^{4}\textrm{K}$. Electrical conductivity of plasma was calculated by using the modified random phase approximation and semiclassical method, adapted for the case of dense, partially ionized plasma. The results were compared with the unique existing experimental data, including the results related to the region of dense plasmas. In spite of low accuracy of the experimental data, the existing agreement with them indicates that results obtained in this paper are correct

Kinetic formulation and global existence for the Hall-Magneto-hydrodynamics system

This paper deals with the derivation and analysis of the the Hall Magneto-Hydrodynamic equations. We first provide a derivation of this system from a two-fluids Euler-Maxwell system for electrons and ions, through a set of scaling limits. We also propose a kinetic formulation for the Hall-MHD equations which contains as fluid closure different variants of the Hall-MHD model. Then, we prove the existence of global weak solutions for the incompressible viscous resistive Hall-MHD model. We use the particular structure of the Hall term which has zero contribution to the energy identity. Finally, we discuss particular solutions in the form of axisymmetric purely swirling magnetic fields and propose some regularization of the Hall equation

Modeling the effect of Mg addition on microstructure and strength of aluminum during severe plastic deformation

Although Al–Mg alloys have various desirable properties, to broaden the applications, it is needed to increase the strength of these alloys. Severe plastic deformation (SPD) is a candidate method for this purpose. In this paper, a model is presented for the strength and microstructure evolution during severe plastic deformation. The model is applied to 5 Al–Mg alloys with different solute contents of 1, 2, 3, 4, and 5 wt% Mg. The model is also employed for pure Al for the sake of comparison. The model evaluates the effectiveness of Mg addition, quantitatively. It is shown that the combining of solute addition and severe plastic deformation can provide a considerable increase in the strength of Al–Mg alloys. Moreover, it is shown that adding Mg solute to pure Al changes the value of the dislocation density more than the values of the cell size and strength. The model also considers two effects for the presence of Mg solute as implicit and explicit effects. Then, the quantitative evaluation is performed. It indicates that the ratio of the effects is dependent on solute content, and the implicit one plays a more significant role

Strength evolution during accumulative roll bonding of the metal matrix composite

The strength evolution during the processing/cycling of the metal matrix composite through accumulative roll bonding (ARB) as a severe plastic deformation method is studied by performing a twofold model. It is shown that the strength evolution during cycling consists of two parts: monolithic-like behavior and composite-like behavior. The contribution of each behavior is obtained. The particle effectiveness is at the lowest value at the beginning of the cycling and reaches its highest during the final cycles. It is shown that there is a critical strain at which monolithic-like behavior initiates to decline. The process also shows a minimum strain at which composite-like behavior dominates

Preparation of YBCO superconductor nanoparticles by sol-gel combustion method

This paper describes the details of synthesizing nano crystalline YBCO superconductor using a sol-gel combustion method and the effect of sol pH and sintering temperature on particle size was investigated. The sintering temperature was chosen 880°C and the samples were annealed at this temperature for 5 hours. The morphology and structure of the nano scale products were characterized by powder X-ray diffraction and scanning electron microscopy. The results showed the samples prepared using the sol with pH of 5 and 7 have mean particle size of 500 and 200 nm, respectively. In order to investigate the effect of sintering temperature on the size of YBCO particles three sets of samples from the sol with pH of 7 were sintered at 800, 880 and 950°C. The results showed the samples sintered at 800, 880 and 950°C have the average particle size of 100, 200 and 400 nm respectively