Introduction: Well type ionization chamber is a measuring device which is used to determine the activity of brachytherapy sources. The chamber has a cylindrical volume in which a cylindrical tube is mounted in the middle of the chamber. For the measurements, the brachytherapy sources are transferred to the middle of the tube. Materials and Methods: For designing the well type chamber, the measu...

The turbulent mixing modeling for unsteady heat transfer problems in thermal-hydraulics has long been a focus in nuclear engineering community. One of the promising approaches that takes a full advantage of recent advances in HPC is the use of hierarchy of fidelity simulations that are cross-verified and validated in the regimes of interest. In particular, it is beneficial to have a higher fide...

In this paper we investigate mixing and transport in correspondence of a meandering jet. The large-scale flow field is a kinematically assigned streamfunction. Two basic mixing mechanisms are considered, first separately and then combined together: deterministic chaotic advection, induced by a time dependence of the flow, and turbulent diffusion, described by means of a stochastic model for par...

Dunne, NJ, Daly, C, Beverland, D Queens University of Belfast, Belf Musgrave Park Hospital, Belfast Introduction It has been shown that acrylic bone cement is weakened by its porosity, which enhances the formation of microcracks that contribute to major crack propagation . It has also been observed, that mixing procedures play a significant role in determining the quality of bone cement produce...

Plume dilution and transverse mixing can be considerably enhanced by helical flow occurring in three-dimensional heterogeneous anisotropic porous media. In this study, we perform tracer experiments in a fully three-dimensional flow-through chamber to investigate the effects of helical flow on plume spiraling and deformation, as well as on its dilution. Porous media were packed in angled stripes...

The performance of a new chemical ionization reaction time-of-flight mass spectrometer (CIR-TOF-MS) utilising the environment chamber SAPHIR (Simulation of Atmospheric Photochemistry In a large Reaction ChamberForschungzentrum Jülich, Germany) is described. The work took place as part of the ACCENT (Atmospheric Composition and Change the European NeTwork for excellence) supported oxygenated vol...

Air distribution systems in commercial aircraft cabins are important for providing a healthy and comfortable environment for passengers and crew. The mixing air distribution systems used in existing aircraft cabins create a uniform air temperature distribution and dilute contaminants in the cabins. The mixing air distribution systems could spread infectious airborne diseases. To improve the air...

The combustion chamber's internal refractory in Imam Khomeini Oil Refinery Company (IKORC) was damaged several parts, requiring operating conditions and re-inspecting the design of chamber using CFD. Simplify 3D simulation, decrease number calculations, symmetry principle applied simulation. results, independent mesh network, were investigated via increasing nodes. one-stage, two-stage, multi-s...

A stopped flow rapid reaction apparatus capable of following changes of +/-0.02 pH unit in 0.1 ml of solution in less than 0.005 sec has been developed, utilizing a commercially available pH-sensitive glass electrode. Using this instrument, extracellular pH at 37 degrees C was followed from less than 0.025 sec to 300 sec after mixing equal volumes of the following CO(2)-free solutions: (A) norm...

We present numerical simulations of DNA-chip hybridization, both in the "static" and "dynamical" cases. In the static case, transport of free targets is limited by molecular diffusion; in the dynamical case, an efficient mixing is achieved by chaotic advection, with a periodic protocol using pumps in a rectangular chamber. This protocol has been shown to achieve rapid and homogeneous mixing. We...