One of the major factors affecting the performance prediction of twin screw compressors by use of computational fluid dynamics (CFD) is the accuracy with which the leakage gaps are captured by the discretization methods. The accuracy of mapping leakage flows can be improved by increasing the number of grid points on the profile. However, this method faces limitations when it comes to the comple...

CSF abnormalities have been reported in CSF leakage syndrome. However, the mechanism for these CSF changes is actually unknown and they may indicate impaired CSF flow or blood-CSF barrier. Angiopoietin-2 (Ang-2), a protein which is expressed and released by endothelial cells, has been associated with increased vascular permeability. In the assumption that CSF changes are due to an impaired bloo...

Quantitative theories of information flow give us an approach to relax the absolute confidentiality properties that are difficult to satisfy for many practical programs. The classical information-theoretic approaches for sequential programs, where the program is modeled as a communication channel with only input and output, and the measure of leakage is based on the notions of initial uncertain...

Most theoretical work done on gas leakage in compressors is concerned with quasi one-dimensional steady-state models. Four of these, each quite different in mathematical formulation and solution strategy, have been implemented and tested. Two experiments reported in literature were used to validate the models. The results show that chocking is likely to occur. Unfortunately none of the models p...

Leakage rates are evaluated for a landfill barrier system having a compacted clay liner (CCL) underlain by a vadose zone of variable thickness. A numerical unsaturated flow model SEEP/W is used to simulate the moisture flow regime and steady-state leakage rates for the cases of unsaturated zones with different soil types and thicknesses. The results of the simulations demonstrate that harmonic ...

We investigated a miniature magnetically levitated centrifugal blood pump intended to deliver 0.3-1.5 l/min of support to neonates and infants. The back clearance gap between the housing and large volume of the rotor, where the suspension and motor bearings are located, forms a continuous leakage flow path. Within the gap, flow demonstrates a very complex three-dimensional structure: the fluid ...

The paper presents a design procedure for anti-vortex endplates that are fitted to tip limited blades of the subsonic axial fans utilised in compact cooling units. The authors study the impact of tip leakage vortex bursting on the performance of the studied class of fans. The vortex breakdown occurs in the swirling flows at a blade’s tip, and is found to be a flow feature associated with the pr...

In the framework of this master thesis, a numerical study has been carried out in order to investigate the effect of tip geometry on the tip leakage flow and heat transfer features in a unshrouded high pressure axial flow turbine stage designed by Erhard [10]. Four different tip profiles were considered, namely a default flat tip, a modified flat tip, a modified double squealer tip and a modifi...

introduction: the provision of an effective apical seal is an essential factor when choosing an appropriate material for success of root-end surgeries. root-end resection, preparation and obturation should provide an adequate apical seal. the aim of this in vitro study was to investigate bacterial and dye microleakage of four different root-end filling materials and compare the efficacy of thes...

In this study cross section geometry and material of gasket in proton exchange membrane (PEM) fuel cells have been investigated to achieve optimized fuel cell in terms of energy efficiency. The role of gaskets in fuel cells is sealing of gas flow channels and preventing from combination of them. In a PEM stack, gasket with approved geometry that suffers more stress has better sealing. For this ...