Creating an entrepreneurial region: exploring the entrepreneurial capacity of the East Midlands

This paper explores the notion of the entrepreneurial region and, in particular, the relevance and appropriateness of this concept to the East Midlands. An outline framework is developed that depicts aspects and dimensions of an entrepreneurial region. This is then applied to the East MIdlands to gauge how entrepreneurial the region is

Partial CFD models of cardiovascular stents

Copyright @ 2002 Wiley BlackwellThis paper outlines the use of a partial CFD stent model in order to improve discretisation of important small features. The effects of mesh size on the performance measure are investigated. The results are compared with those from full models and also comparisons with clinical trials are made. It is shown that partial models provide a better approximation to reality than full models when using modest PC workstation resources. The general conclusion is that computer-based design of medical devices must take into account the variations in geometry between patients by means of, for example, a flat performance curve against noise

Genetic algorithm search for stent design improvements

Copyright @ 2002 SpringerThis paper presents an optimisation process for finding improved stent design using Genetic Algorithms. An optimisation criterion based on dissipated power is used which fits with the accepted principle that arterial flows follow a minimum energy loss. The GA shows good convergence and the solution found exhibits improved performance over proprietary designs used for comparison purposes

Effects of stents under asymmetric inflow conditions

This is the post-print version of the Article. The official published version can be accessed from the link below. Copyright @ 2002 IOS PressPatient-to-patient variations in artery geometry may determine their susceptibility to stenosis formation. These geometrical variations can be linked to variations in flow characteristics such as wall shear stress through stents, which increases the risk of restenosis. This paper considers computer models of stents in non-symmetric flows and their effects on flow characteristics at the wall. This is a fresh approach from the point of view of identifying a stent design whose performance is insensitive to asymmetric flow. Measures of dissipated energy and power are introduced in order to discriminate between competing designs of stents

Active noise control on high frequency narrow band dental drill noise: Preliminary results

Dental drills produce a characteristic noise that is uncomfortable for patients and is also known to be harmful to dentists under prolonged exposure. It is therefore desirable to protect the patient and dentist whilst allowing two-way communication. A solution is to use a combination of the three main noise cancellation methods, namely, Passive Noise Control, Adaptive Filtering and Active Noise Control. Dental drill noise occurs at very high frequency ranges in relation to conventional ANC, typically 2kHz to 6kHz and it has a narrow band characteristic due to the direct relation of the noise to the rotational speed of the bearing. This paper presents a design of an experimental rig where first applications of ANC on dental drill noise are executed using the standard filtered reference Least Mean Square (FXLMS) algorithm. The secondary path is kept as simple as possible, due to the high frequency range of interest, and hence is chosen as the space between headphone loudspeaker and error microphone placed in the ear (input of the headphone loudspeaker and the output of the error microphone). A standard headphone loudspeaker is used for the control source and the microphone inside of an “Ear and Cheek Simulator Type 43AG” is used as the error microphone. The secondary path transfer function is obtained and preliminary results of the application of ANC are discussed

Dental drill noise reduction using a combination of active noise control, passive noise control and adaptive filtering

Dental drills produce a characteristic high frequency, narrow band noise that is uncomfortable for patients and is also known to be harmful to dentists under prolonged exposure. It is therefore desirable to protect the patient and dentist whilst allowing two-way communication. A solution is to use a combination of the three main noise control methods, namely, Passive Noise Control (PNC), Adaptive Filtering (AF) and Active Noise Control (ANC). This paper discusses the application of the three methods to reduce dental drill noise while allowing two-way communication. Experimental setup for measuring the noise reduction by PNC is explained and results from different headphones and headphone types are presented. The implementation and results of an AF system using the Least Mean Square (LMS) algorithm are shown. ANC requires a modification of the LMS algorithm due to the introduction of the electro-acoustical cancellation path transfer function to compensate for the delays introduced by the control system. Therefore a cancellation path transfer function modeling method based on the filtered reference LMS (FXLMS) algorithm is presented along with preliminary results of the implementation

Modelling of two-component turbulent mass and heat transfer in air-fed pressurised suits

This article has been accepted for publication in the Flow, Turbulence and Combustion journal.In this paper the modelling of an important industrial problem is addressed, which involves the two-component turbulent flow with heat transfer that takes place inside protective clothing. The geometry of the flow boundaries is reconstructed in a CAD system from photogrammetry scan data. The overall model is sufficiently realistic to allow, after validation, design improvements to be tested. Those presented here allow the reduction of hot spots over the worker’s body surface and increase thermal comfort.This project is funded by the Engineering and Physical Sciences Research Council and the UK Atomic Energy Authority

Heat and mass transfer in air-fed pressurised suits

Air-fed pressurised suits are used to protect workers against contamination and hazardous environments. The specic application here is the necessity for regular clean-up maintenance within the torus chamber of fusion reactors. The current design of suiting has been developed empirically. It is, therefore, very desirable to formulate a thermofluids model, which will be able to define optimum designs and operating parameters. Two factors indicate that the modelling should be as comprehensive as possible. Firstly, the overall thermofluids problem is three-dimensional and includes mass as well as heat transfer. The fluid field is complex, bounded on one side by the human body and on the other by what may be distensible, porous and multi-layer clothing. In this paper, we report firstly the modelling necessary for the additional mass and heat transport processes. This involves the use of Fick's and Fourier's laws and conjugate heat transfer. The results of an initial validation study are presented. Temperatures at the outlet of the suits were obtained experimentally and compared with those predicted by the overall CFD model. Realistic three-dimensional geometries were used for the suit and human body. Calculations were for turbulent flow with single- and two-component (species) models

A thermo-fluid model for protective suiting used in fusion reactor shutdown operations

In this paper we report a method of modelling the overall thermo-fluid processes which occur in protective suiting as used in the Joint European Torus (JET) fusion reactor at Culham, UK. It had three main objectives: to be as basic and comprehensive as possible, to have an ability to model real situations and suiting, and hence to provide a tool for improvements in design. Basic thermo-fluids equations for multi-component and multi-phase flow have been developed within commercial Computational Fluid Dynamics (CFD) software to address the heat and mass (moisture) transfer processes. This is combined with a human metabolic heat load model to simulate working operations. Finally, a particular feature is the definition of the 3-D human body/suit microclimate, via the use of an unsuited and suited mannequin. This involved a geometrical reconstruction method developed from the point cloud data given by photogrammetry. Examples of predicted temperature distributions are compared with experimental data to show the potential of the model we have used