Clinical Application of the Hanover Classification for Iatrogenic Bile Duct Lesions

Background. There is only limited evidence available to justify generalized clinical classification and treatment recommendations for iatrogenic bile duct lesions. Methods. Data of 93 patients with iatrogenic bile duct lesions was evaluated retrospectively to analyse the variety of encountered lesions with the Hanover classification and its impact on surgical treatment and outcomes. Results. Bile duct lesions combined with vascular lesions were observed in 20 patients (21.5%). 18 of these patients were treated with additional partial hepatectomy while the majority were treated by hepaticojejunostomy alone (n = 54). Concomitant injury to the right hepatic artery resulted in additional right anatomical hemihepatectomy in 10 of 18 cases. 8 of 12 cases with type A lesions were treated with drainage alone or direct suture of the bile leak while 2 patients with a C2 lesion required a Whipple's procedure. Observed congruence between originally proposed lesion-type-specific treatment and actually performed treatment was 66–100% dependent on the category of lesion type. Hospital mortality was 3.2% (n = 3). Conclusions. The Hannover classification may be helpful to standardize the systematic description of iatrogenic bile duct lesions in order to establish evidence-based and lesion-type-specific treatment recommendations

The use of weak waves as diagnostic tracers in unsteady flows

Paper presented at the 5th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, South Africa, 1-4 July, 2007.This paper examines the tracing of the trajectories of weak waves behind a shock wave induced flow in order to establish how the domain shape influences the flow both from a spatial and temporal perspective. The basic principle is that if a particle produces a series of point disturbances in a flow field the perturbations induced will propagate outwards at the local sonic velocity whilst at the same time being convected along with the local flow velocity. A number of issues may be identified for an unsteady flow. Firstly the flow field at later times may be influenced by perturbations produced at earlier times. Secondly, if the positions of the perturbations can be monitored as a function of time then the trajectory and velocity of the particle may be deduced. Thirdly, if a perturbation arises from a point on a boundary then its influence, if any, on any particular part of the flow can be established.cs201

Aerodynamics of a Supersonic Projectile in Proximity to a Solid Surface

Flow around a Mach 2.4 NATO 5.56 mm projectile in close proximity to a ground plane was investigated using computational fluid dynamics for a direct numerical reproduction of live-range experiments. The numerical approach was validated against both the live-range tests and subsequent wind-tunnel experiments. A nonspinning half-model and a full, spinning projectile were examined to clarify the influence of rotation. Multiple ground clearances were tested to obtain clear trends in changes to the aerodynamic coefficients, and the three-dimensional propagation and reflection of the shock waves were considered in detail. The behavior of the flow in the near wake was also studied as ground clearance was reduced. Ground proximity was found to significantly increase the drag force acting on the projectile, as well as generate a force normal to the ground and an increased side force, when ground clearance was less than one diameter. For clearances between approximately 0.4 and 1 diameter, the pitching moment produced was nose-down. For lower clearances, a more distinct nose-up trend was produced. The generated side force was orders of magnitude lower than the normal and drag forces

On the measurement of laser-induced plasma breakdown thresholds

The breakdown threshold of a gas exposed to intense laser-radiation is a function of gas and laser properties. Breakdown thresholds reported in the literature often vary greatly and these differences can partially be traced back to the method that is typically used to determine breakdown thresholds. This paper discusses the traditional method used to determine breakdown thresholds and the potential errors that can arise using this approach, and presents an alternative method which can yield more accurate data especially when determining breakdown thresholds as functions of gas pressure

Segregation and mixing of granular material in industrial processes

Within the EU-funded PARDEM network mixing and segregation are studied in silos and heaps, agitated mixers and fluidized beds. A method is presented with which mixing and segregation can be characterized, adapted for quasi-static to dynamic systems and applied at the global system level as well as at the local level. This paper attempts to give an overview of the applicability of this analysis by providing three instances, being chute flow representing flow down a heap, agitated mixing and fluidization, in which the method is applied