Mycobacteria infection in an immunocompetent patient with no risk factors: evaluation and management of non-healing majocchi granuloma-type nodule

Atypical mycobacterial infections are more commonly described among immunocompromised patients, although there has been an increasing incidence in recent years of infections in immunocompetent hosts. Normally preceding trauma is a risk factor for infection. We describe a case of Mycobacteria chelonae infection in a healthy individual with no risk factors

Mycobacteria infection in an immunocompetent patient with no risk factors: evaluation and management of non-healing majocchi granuloma-type nodule

Atypical mycobacterial infections are more commonly described among immunocompromised patients, although there has been an increasing incidence in recent years of infections in immunocompetent hosts. Normally preceding trauma is a risk factor for infection. We describe a case of Mycobacteria chelonae infection in a healthy individual with no risk factors

Parallel direct numerical simulation of an annular gas-liquid two-phase jet with swirl

The flow characteristics of an annular swirling liquid jet in a gas medium have been examined by direct solution of the compressible Navier-Stokes equations. A mathematical formulation is developed that is capable of representing the two-phase flow system while the volume of fluid method has been adapted to account for the gas compressibility. The effect of surface tension is captured by a continuum surface force model. Analytical swirling inflow conditions have been derived that enable exact definition of the boundary conditions at the domain inlet. The mathematical formulation is then applied to the computational analysis to achieve a better understanding on the flow physics by providing detailed information on the flow development. Fully 3D parallel direct numerical simulation (DNS) has been performed utilizing 512 processors, and parallelization of the code was based on domain decomposition. The numerical results show the existence of a recirculation zone further down the nozzle exit. Enhanced and sudden liquid dispersion is observed in the cross-stream wise direction with vortical structures developing at downstream locations due to Kelvin-Helmholtz instability. Downstream the flow becomes more energetic, and analysis of the energy spectra shows that the annular gas-liquid two-phase jet has a tendency of transition to turbulence

Dynamics of annular gas-liquid two-phase swirling jets

The dynamics of annular gas-liquid two-phase swirling jets have been examined by means of direct numerical simulation and proper orthogonal decomposition. An Eulerian approach with mixed-fluid treatment, combined with an adapted volume of fluid and a continuum surface force model, was used to describe the two-phase flow system. The unsteady, compressible, three-dimensional Navier-Stokes equations have been solved by using highly accurate numerical methods. Two computational cases have been performed to examine the effects of liquid-to-gas density ratio on the flow development. It was found that the higher density ratio case is more vortical with larger spatial distribution of the liquid, in agreement with linear theories. Proper orthogonal decomposition analysis revealed that more modes are of importance at the higher density ratio, indicating a more unstable flow field. In the lower density ratio case, both a central and a geometrical recirculation zone are captured while only one central recirculation zone is evident at the higher density ratio. The results also indicate the formation of a precessing vortex core at the high density ratio, indicating that the precessing vortex core development is dependent on the liquid-to-gas density ratio of the two-phase flow, apart from the swirl number alone

Numerical investigation of a perturbed swirling annular two-phase jet

A swirling annular gas-liquid two-phase jet flow system has been investigated by solving the compressible, time-dependent, non-dimensional Navier-Stokes equations using highly accurate numerical methods. The mathematical formulation for the flow system is based on an Eulerian approach with mixed-fluid treatment while an adjusted volume of fluid method is utilised to account for the gas compressibility. Surface tension effects are captured by a continuum surface force model. Swirling motion is applied at the inlet while a small helical perturbation is also applied to initiate the instability. Three-dimensional spatial direct numerical simulation has been performed with parallelisation of the code based on domain decomposition. The results show that the flow is characterised by a geometrical recirculation zone adjacent to the nozzle exit and by a central recirculation zone further downstream. Swirl enhances the flow instability and vorticity and promotes liquid dispersion in the cross-stream wise directions. A dynamic precessing vortex core is developed demonstrating that the growth of such a vortex in annular configurations can be initiated even at low swirl numbers, in agreement with experimental findings. Analysis of the averaged results revealed the existence of a geometrical recirculation zone and a swirl induced central recirculation zone in the flow field

Circumscribed palmoplantar hypokeratosis: a case report and review of the literature

We describe an 84-year-old man presenting with a solitary, well-circumscribed, chronic erosion of the sole. Histopathologic examination confirmed diagnosis of circumscribed palmoplantar hypokeratosis. Circumscribed palmoplantar hypokeratosis is a rare and benign condition of unknown etiology presenting as an erosion on the palms or soles. Although lesions are typically asymptomatic, the entity is important for dermatologists and providers in other specialties to recognize, especially considering a differential diagnosis that includes neoplasia

Development of an efficient statistical volumes of fluid-Lagrangian particle tracking coupling method

The breakup of a liquid jet into irregular liquid structures and droplets leading to the formation of a dilute spray has been simulated numerically. To overcome the shortcomings of certain numerical methods in specific flow regimes, a combined approach has been chosen. The intact liquid core, its primary breakup and the dense spray regime are simulated using the volumes of fluid (VOF) method in combination with LES, whereas the Lagrangian particle tracking (LPT) approach in the LES context is applied to the dilute spray regime and the secondary breakup of droplets. A method has been developed to couple both simulation types on a statistical basis. This statistical coupling approach (SCA) reflects the dominating physical mechanisms of the two-phase flow in each regime to a high degree. The main benefit of the SCA is computational efficiency as compared with the more straightforward approach where one follows each structure, denoted here as the direct coupling approach. The computational benefits stem from the reduction of computational time since the VOF simulation is run only until statistical convergence and not during the whole spray development. A second benefit using the SCA is the possibility to use the stochastic parcel method in the LPT simulation whereby a large number of droplets may be handled. The coupling approach is applied to the atomization of a fuel jet in a high pressure chamber, demonstrating the gain of efficiency of the SCA as compared with direct coupling approach. Copyright © 2014 The Authors. International Journal for Numerical Methods in Fluids published by John Wiley & Sons Ltd